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Sample records for osteochondral tissue grafts

  1. Bioreactor-based engineering of osteochondral grafts: from model systems to tissue manufacturing.

    PubMed

    Wendt, David; Jakob, Marcel; Martin, Ivan

    2005-11-01

    Osteochondral defects (i.e., those that affect both the articular cartilage and underlying subchondral bone) are often associated with mechanical instability of the joint, and therefore with the risk of inducing osteoarthritic degenerative changes. The in vitro fabrication of osteochondral grafts of predefined size and shape, starting from autologous cells combined with three-dimensional porous biomaterials, is a promising approach for the treatment of osteochondral defects. However, the quality of ex vivo generated cartilage and bone-like tissues is currently restricted by a limited understanding of the regulatory role of physicochemical culture parameters on tissue development. By allowing reproducible and controlled changes in specific biochemical and biomechanical factors, bioreactor systems provide the technological means to reveal fundamental mechanisms of cell function in a three-dimensional environment and the potential to improve the quality of engineered tissues. In addition, by automating and standardizing the manufacturing process in controlled closed systems, bioreactors could reduce production costs and thus facilitate broader clinical impact of engineered osteochondral grafts.

  2. Challenges in engineering osteochondral tissue grafts with hierarchical structures Ivana Gadjanski, Gordana Vunjak Novakovic

    PubMed Central

    Gadjanski, Ivana; Vunjak-Novakovic, Gordana

    2015-01-01

    Introduction A major hurdle in treating osteochondral (OC) defects are the different healing abilities of two types of tissues involved - articular cartilage and subchondral bone. Biomimetic approaches to OC-construct-engineering, based on recapitulation of biological principles of tissue development and regeneration, have potential for providing new treatments and advancing fundamental studies of OC tissue repair. Areas covered This review on state of the art in hierarchical OC tissue graft engineering is focused on tissue engineering approaches designed to recapitulate the native milieu of cartilage and bone development. These biomimetic systems are discussed with relevance to bioreactor cultivation of clinically sized, anatomically shaped human cartilage/bone constructs with physiologic stratification and mechanical properties. The utility of engineered OC tissue constructs is evaluated for their use as grafts in regenerative medicine, and as high-fidelity models in biological research. Expert opinion A major challenge in engineering OC tissues is to generate a functionally integrated stratified cartilage-bone structure starting from one single population of mesenchymal cells, while incorporating perfusable vasculature into the bone, and in bone-cartilage interface. To this end, new generations of advanced scaffolds and bioreactors, implementation of mechanical loading regimens, and harnessing of inflammatory responses of the host will likely drive the further progress. PMID:26195329

  3. Fabrication of tissue engineered osteochondral grafts for restoring the articular surface of diarthrodial joints

    PubMed Central

    Roach, Brendan L.; Hung, Clark T.; Cook, James L.; Ateshian, Gerard A.; Tan, Andrea R.

    2015-01-01

    Osteochondral allograft implantation is an effective cartilage restoration technique for large defects (>10 cm2), though the demand far exceeds the supply of available quality donor tissue. Large bilayered engineered cartilage tissue constructs with accurate anatomical features (i.e. contours, thickness, architecture) could be beneficial in replacing damaged tissue. When creating these osteochondral constructs, however, it is pertinent to maintain biofidelity to restore functionality. Here, we describe a step-by-step framework for the fabrication of a large osteochondral construct with correct anatomical architecture and topology through a combination of high-resolution imaging, rapid prototyping, impression molding, and injection molding. PMID:25794950

  4. Fabrication of tissue engineered osteochondral grafts for restoring the articular surface of diarthrodial joints.

    PubMed

    Roach, Brendan L; Hung, Clark T; Cook, James L; Ateshian, Gerard A; Tan, Andrea R

    2015-08-01

    Osteochondral allograft implantation is an effective cartilage restoration technique for large defects (>10 cm(2)), though the demand far exceeds the supply of available quality donor tissue. Large bilayered engineered cartilage tissue constructs with accurate anatomical features (i.e. contours, thickness, architecture) could be beneficial in replacing damaged tissue. When creating these osteochondral constructs, however, it is pertinent to maintain biofidelity to restore functionality. Here, we describe a step-by-step framework for the fabrication of a large osteochondral construct with correct anatomical architecture and topology through a combination of high-resolution imaging, rapid prototyping, impression molding, and injection molding. PMID:25794950

  5. Costal osteochondral grafts for osteochondritis dissecans of the capitulum humeri.

    PubMed

    Sato, Kazuki; Nakamura, Toshiyasu; Toyama, Yoshiaki; Ikegami, Hiroyasu

    2008-06-01

    The objective of the treatment for osteochondritis dissecans of the humeral capitulum is to prevent the occurrence of osteoarthritis and to allow the patients to return to throwing activities. In repairing osteochondral defects in advanced osteochondritis dissecans of the humeral capitulum after free body removal, we have performed block-shaped costal osteochondral grafting in 18 elbows since 1997. A block-shaped graft harvested from the transitional area between the rib and its associated cartilage was implanted to the osteochondral defect. This method allows the osteochondral defect to be repaired with uniform hyaline cartilaginous articular surface without any effect to other joints. Donor site no longer causes pain at 2 or 3 days after surgery. The purpose of this study is to describe the history, indications, and the surgical techniques of costal osteochondral grafting for advanced osteochondritis dissecans of the capitulum.

  6. Review of the biomechanics and biotribology of osteochondral grafts used for surgical interventions in the knee

    PubMed Central

    Bowland, Philippa; Ingham, E; Jennings, Louise; Fisher, John

    2015-01-01

    A review of research undertaken to evaluate the biomechanical stability and biotribological behaviour of osteochondral grafts in the knee joint and a brief discussion of areas requiring further improvement in future studies are presented. The review takes into consideration osteochondral autografts, allografts, tissue engineered constructs and synthetic and biological scaffolds. PMID:26614801

  7. Treatment of severe osteochondritis dissecans of the elbow using osteochondral grafts from a rib.

    PubMed

    Oka, Y; Ikeda, M

    2001-07-01

    We treated a patient with extensive osteochondritis dissecans of the elbow by an osteochondral graft from a rib. It had consolidated seven months after operation. When seen at follow-up, after seven years and eight months, the elbow was free from pain with an improvement in the range of movement of 24 degrees.

  8. MR imaging of osteochondral grafts and autologous chondrocyte implantation

    PubMed Central

    Millington, S. A.; Szomolanyi, P.; Marlovits, S.

    2006-01-01

    Surgical articular cartilage repair therapies for cartilage defects such as osteochondral autograft transfer, autologous chondrocyte implantation (ACI) or matrix associated autologous chondrocyte transplantation (MACT) are becoming more common. MRI has become the method of choice for non-invasive follow-up of patients after cartilage repair surgery. It should be performed with cartilage sensitive sequences, including fat-suppressed proton density-weighted T2 fast spin-echo (PD/T2-FSE) and three-dimensional gradient-echo (3D GRE) sequences, which provide good signal-to-noise and contrast-to-noise ratios. A thorough magnetic resonance (MR)-based assessment of cartilage repair tissue includes evaluations of defect filling, the surface and structure of repair tissue, the signal intensity of repair tissue and the subchondral bone status. Furthermore, in osteochondral autografts surface congruity, osseous incorporation and the donor site should be assessed. High spatial resolution is mandatory and can be achieved either by using a surface coil with a 1.5-T scanner or with a knee coil at 3 T; it is particularly important for assessing graft morphology and integration. Moreover, MR imaging facilitates assessment of complications including periosteal hypertrophy, delamination, adhesions, surface incongruence and reactive changes such as effusions and synovitis. Ongoing developments include isotropic 3D sequences, for improved morphological analysis, and in vivo biochemical imaging such as dGEMRIC, T2 mapping and diffusion-weighted imaging, which make functional analysis of cartilage possible. PMID:16802126

  9. Recent progress in interfacial tissue engineering approaches for osteochondral defects.

    PubMed

    Castro, Nathan J; Hacking, S Adam; Zhang, Lijie Grace

    2012-08-01

    This review provides a brief synopsis of the anatomy and physiology of the osteochondral interface, scaffold-based and non-scaffold based approaches for engineering both tissues independently as well as recent developments in the manufacture of gradient constructs. Novel manufacturing techniques and nanotechnology will be discussed with potential application in osteochondral interfacial tissue engineering. PMID:22677924

  10. Treatment of unstable osteochondritis dissecans in adults with autogenous osteochondral grafts (Mosaicplasty): long-term results

    PubMed Central

    RONGA, MARIO; STISSI, PLACIDO; LA BARBERA, GIUSEPPE; VALOROSO, MARCO; ANGERETTI, GLORIA; GENOVESE, EUGENIO; CHERUBINO, PAOLO

    2015-01-01

    Purpose the unstable osteochondritis dissecans (OCD-type II and III according to the ICRS classification) of the knee largher than > 2.5 cm2 in adults are uncommon lesions and there is no consensus on how to treat them. Medium-term studies have reported good results using autogenous osteochondral plugs (mosaicplasty). The aim of this study is to analyze the long-term results of this technique for the treatment of unstable OCD in a selected group of adult patients. Methods four patients with OCD at either one of the femoral condyles were included in this prospective study. The average age was 21.2 years (range, 18–24 years). The OCD lesions were classified as type II in three patients and type III in one patient and the average size was 3.8 cm2 (range, 2.55–5.1 cm2). The lesions were treated in situ with a variable number of autogenous osteochondral plugs (Ø 4.5 mm2). The Modified Cincinnati, Lysholm II and Tegner scores were used for clinical and functional evaluation. Magnetic resonance arthrography (MRA) was performed before surgery and at 2, 5 and 10 years after surgery. A modified MOCART score was used to evaluate MRA findings. Results the average follow-up duration was ten years and 6 months (range, 10–11 years). No complications occurred. At the final follow-up, all scores (clinical, functional and MOCART) improved. In all but one of the patients MRA showed complete osteochondral repair. Conclusions the fixation of large and unstable OCD lesions with mosaicplasty may be a good option for treating type II or III OCD lesions in adults. The advantages of this technique include stable fixation, promotion of blood supply to the base of the OCD fragment, and grafting of autologous cancellous bone that stimulates healing with preservation of the articular surface. Level of evidence Level IV, therapeutic case series. PMID:26904522

  11. Design and characterization of a tissue-engineered bilayer scaffold for osteochondral tissue repair.

    PubMed

    Giannoni, Paolo; Lazzarini, Erica; Ceseracciu, Luca; Barone, Alberto C; Quarto, Rodolfo; Scaglione, Silvia

    2015-10-01

    Treatment of full-thickness cartilage defects relies on osteochondral bilayer grafts, which mimic the microenvironment and structure of the two affected tissues: articular cartilage and subchondral bone. However, the integrity and stability of the grafts are hampered by the presence of a weak interphase, generated by the layering processes of scaffold manufacturing. We describe here the design and development of a bilayer monolithic osteochondral graft, avoiding delamination of the two distinct layers but preserving the cues for selective generation of cartilage and bone. A highly porous polycaprolactone-based graft was obtained by combining solvent casting/particulate leaching techniques. Pore structure and interconnections were designed to favour in vivo vascularization only at the bony layer. Hydroxyapatite granules were added as bioactive signals at the site of bone regeneration. Unconfined compressive tests displayed optimal elastic properties and low residual deformation of the graft after unloading (< 3%). The structural integrity of the graft was successfully validated by tension fracture tests, revealing high resistance to delamination, since fractures were never displayed at the interface of the layers (n = 8). Ectopic implantation of grafts in nude mice, after seeding with bovine trabecular bone-derived mesenchymal stem cells and bovine articular chondrocytes, resulted in thick areas of mature bone surrounding ceramic granules within the bony layer, and a cartilaginous alcianophilic matrix in the chondral layer. Vascularization was mostly observed in the bony layer, with a statistically significant higher blood vessel density and mean area. Thus, the easily generated osteochondral scaffolds, since they are mechanically and biologically functional, are suitable for tissue-engineering applications for cartilage repair.

  12. Mechanical effects of surgical procedures on osteochondral grafts elucidated by osmotic loading and real-time ultrasound

    PubMed Central

    2009-01-01

    Introduction Osteochondral grafts have become popular for treating small, isolated and full-thickness cartilage lesions. It is recommended that a slightly oversized, rather than an exact-sized, osteochondral plug is transplanted to achieve a tight fit. Consequently, impacting forces are required to insert the osteochondral plug into the recipient site. However, it remains controversial whether these impacting forces affect the biomechanical condition of the grafted articular cartilage. The present study aimed to investigate the mechanical effects of osteochondral plug implantation using osmotic loading and real-time ultrasound. Methods A full-thickness cylindrical osteochondral defect (diameter, 3.5 mm; depth, 5 mm) was created in the lateral lower quarter of the patella. Using graft-harvesting instruments, an osteochondral plug (diameter, 3.5 mm as exact-size or 4.5 mm as oversize; depth, 5 mm) was harvested from the lateral upper quarter of the patella and transplanted into the defect. Intact patella was used as a control. The samples were monitored by real-time ultrasound during sequential changes of the bathing solution from 0.15 M to 2 M saline (shrinkage phase) and back to 0.15 M saline (swelling phase). For cartilage sample assessment, three indices were selected, namely the change in amplitude from the cartilage surface (amplitude recovery rate: ARR) and the maximum echo shifts from the cartilage surface and the cartilage-bone interface. Results The ARR is closely related to the cartilage surface integrity, while the echo shifts from the cartilage surface and the cartilage-bone interface are closely related to tissue deformation and NaCl diffusion, respectively. The ARR values of the oversized plugs were significantly lower than those of the control and exact-sized plugs. Regarding the maximum echo shifts from the cartilage surface and the cartilage-bone interface, no significant differences were observed among the three groups. Conclusions These findings

  13. Biofabrication of osteochondral tissue equivalents by printing topologically defined, cell-laden hydrogel scaffolds.

    PubMed

    Fedorovich, Natalja E; Schuurman, Wouter; Wijnberg, Hans M; Prins, Henk-Jan; van Weeren, P René; Malda, Jos; Alblas, Jacqueline; Dhert, Wouter J A

    2012-01-01

    Osteochondral defects are prone to induce osteoarthritic degenerative changes. Many tissue-engineering approaches that aim to generate osteochondral implants suffer from poor tissue formation and compromised integration. This illustrates the need for further improvement of heterogeneous tissue constructs. Engineering of these structures is expected to profit from strategies addressing the complexity of tissue organization and the simultaneous use of multiple cell types. Moreover, this enables the investigation of the effects of three-dimensional (3D) organization and architecture on tissue function. In the present study, we characterize the use of a 3D fiber deposition (3DF) technique for the fabrication of cell-laden, heterogeneous hydrogel constructs for potential use as osteochondral grafts. Changing fiber spacing or angle of fiber deposition yielded scaffolds of varying porosity and elastic modulus. We encapsulated and printed fluorescently labeled human chondrocytes and osteogenic progenitors in alginate hydrogel yielding scaffolds of 1×2 cm with different parts for both cell types. Cell viability remained high throughout the printing process, and cells remained in their compartment of the printed scaffold for the whole culture period. Moreover, distinctive tissue formation was observed, both in vitro after 3 weeks and in vivo (6 weeks subcutaneously in immunodeficient mice), at different locations within one construct. These results demonstrate the possibility of manufacturing viable centimeter-scaled structured tissues by the 3DF technique, which could potentially be used for the repair of osteochondral defects. PMID:21854293

  14. Early Postoperative Magnetic Resonance Imaging Findings After Autologous Osteochondral Plug Grafts For Osteochondritis Dissecans of the Humeral Capitellum

    PubMed Central

    Maruyama, Masahiro; Takahara, Masatoshi; Harada, Mikio; Satake, Hiroshi; Uno, Tomohiro; Takagi, Michiaki

    2016-01-01

    Objectives: Although good clinical outcomes of autologous osteochondral plug grafts for capitellar osteochondritis dissecans (OCD) have been reported, the timing of return to sports was various and still controversial. The period of graft incorporation and the lesion healing at repair site is important to establish the rehabilitation protocol, however there is little information. The aim of this study was to investigate early postoperative magnetic resonance imaging (MRI) findings and clinical outcomes after autologous osteochondral plug grafts for capitellar OCD. Methods: Fifteen young baseball players with advanced lesions of capitellar OCD underwent a procedure using autologous osteochondral plug grafts and underwent MRI (1.5 T) scan at 3 and 6 months, postoperatively. Their mean age at the time of surgery was 13.5 years (range, 13-15 years). Four lesions were classified as International Cartilage Repair Society (ICRS) OCD III and 11 lesions as OCD IV. The mean size of the lesions (sagittal × coronal) was 16 × 14 mm and the mean surface area was 181 mm2. One to two osteochondral plug grafts, with a mean diameter of 7 mm (range, 6-8 mm), were harvested from the lateral femoral condyle and transplanted to the defects. The mean reconstruction rate was 41% (range, 12%-65%), which was calculated as (total surface area of the grafts × 100%)/ (surface area of the lesion). Patients were allowed to begin throwing after 3 months and to return to sports after 6 months. The mean follow-up was 21 months (range, 12-36 months). The MRI findings were assessed graft incorporation, which was indicated by no T1-low-signal-intensity at the graft and no fluid surrounding the graft on T2-weighted fat-suppression (Figure 1), and the lesion healing according to the scoring system of Henderson (4, complete healing; 16, no healing). MRI were blinded and randomized, and two observers reviewed independently and conferred when they differed. Clinical outcomes were evaluated as elbow pain

  15. Hydrogen Supplementation of Preservation Solution Improves Viability of Osteochondral Grafts

    PubMed Central

    Yamada, Takuya; Onuma, Kenji; Kuzuno, Jun; Ujihira, Masanobu; Kurokawa, Ryosuke; Sakai, Rina; Takaso, Masashi

    2014-01-01

    Allogenic osteochondral tissue (OCT) is used for the treatment of large cartilage defects. Typically, OCTs collected during the disease-screening period are preserved at 4°C; however, the gradual reduction in cell viability during cold preservation adversely affects transplantation outcomes. Therefore, improved storage methods that maintain the cell viability of OCTs are needed to increase the availability of high-quality OCTs and improve treatment outcomes. Here, we evaluated whether long-term hydrogen delivery to preservation solution improved the viability of rat OCTs during cold preservation. Hydrogen-supplemented Dulbecco's Modified Eagles Medium (DMEM) and University of Wisconsin (UW) solution both significantly improved the cell viability of OCTs during preservation at 4°C for 21 days compared to nonsupplemented media. However, the long-term cold preservation of OCTs in DMEM containing hydrogen was associated with the most optimal maintenance of chondrocytes with respect to viability and morphology. Our findings demonstrate that OCTs preserved in DMEM supplemented with hydrogen are a promising material for the repair of large cartilage defects in the clinical setting. PMID:25506061

  16. Fragment fixation with a bone graft and dynamic staples for osteochondritis dissecans of the humeral capitellum.

    PubMed

    Harada, Mikio; Ogino, Toshihiko; Takahara, Masatoshi; Ishigaki, Daisuke; Kashiwa, Hideo; Kanauchi, Yumiko

    2002-01-01

    To attain bony union of the fragment in osteochondritis dissecans of the humeral capitellum, fragment fixation was performed with a bone graft and dynamic staples in 4 patients. The staples were inserted not from the articular surface but from the lateral aspect of the capitellum. All patients achieved bony union without complication, and 3 of them returned to playing competitive baseball. At final follow-up after surgery (mean, 7.5 years [range, 2.1-11 years]), 3 patients were able to throw a ball without pain and the remaining patient felt elbow dullness after he played recreational-level baseball as a pitcher. These results suggest that the procedure of fragment fixation with a bone graft and dynamic staples can provide satisfactory results for osteochondritis dissecans of the humeral capitellum with a large osteochondral fragment.

  17. The effect of devitalized trabecular bone on the formation of osteochondral tissue-engineered constructs

    PubMed Central

    Lima, Eric G.; Chao, Pen-hsiu Grace; Ateshian, Gerard A.; Bal, B. Sonny; Cook, James L.; Vunjak-Novakovic, Gordana; Hung, Clark T.

    2008-01-01

    In the current study, evidence is presented demonstrating that devitalized trabecular bone has an inhibitory effect on in vitro chondral tissue development when used as a base material for the tissue-engineering of osteochondral constructs for cartilage repair. Chondrocyte-seeded agarose hydrogel constructs were cultured alone or attached to an underlying bony base in a chemically defined medium formulation that has been shown to yield engineered cartilaginous tissue with native Young's modulus (EY) and glycosaminoglycan (GAG) content. By day 42 in culture the incorporation of a bony base significantly reduced these properties (EY = 87 ± 12 kPa, GAG = 1.9 ± 0.8%ww) compared to the gel-alone group (EY = 642 ± 97 kPa, GAG = 4.6 ± 1.4%ww). Similarly, the mechanical and biochemical properties of chondrocyte-seeded agarose constructs were inhibited when co-cultured adjacent to bone (unattached), suggesting that soluble factors rather than direct cell–bone interactions mediate the chondro-inhibitory bone effects. Altering the method of bone preparation, including demineralization, or the timing of bone introduction in co-culture did not ameliorate the effects. In contrast, osteochondral constructs with native cartilage properties (EY = 730 ± 65 kPa, GAG = 5.2 ± 0.9%ww) were achieved when a porous tantalum metal base material was adopted instead of bone. This work suggests that devitalized bone may not be a suitable substrate for long-term cultivation of osteochondral grafts. PMID:18718655

  18. Effect of tissue culture storage on the in vivo survival of canine osteochondral allografts.

    PubMed

    Oates, K M; Chen, A C; Young, E P; Kwan, M K; Amiel, D; Convery, F R

    1995-07-01

    In vitro studies in our laboratory have shown that the biomechanical and biochemical characteristics of osteochondral grafts can be preserved for as long as 28 days under tissue culture conditions. This study represents an attempt to extend these results to an in vivo model. In adult mongrel dogs, either an autograft, a fresh allograft, or a stored allograft was placed in a standardized defect on the weight-bearing surface of the medial femoral condyle. The stored grafts were kept at 4 degrees C in tissue culture medium for 14 days prior to implantation. The animals were killed at 12 weeks. Cartilage from the contralateral knee served as a control. The modulus and permeability of the cartilage were assessed with confined compression creep tests. The collagen and glycosaminoglycan contents were measured, and the cartilage was analyzed histologically with hematoxylin and eosin and safranin O stains. Grossly, the cartilage appeared viable at harvest. The histologic results were similar in the treatment groups, with the same spectrum of mild degenerative changes being noted in each group. The glycosaminoglycan content was significantly less in the autograft group than in its control group and than in the fresh allograft group. The glycosaminoglycan content did not differ significantly between fresh and stored allografts. The collagen content, modulus, and permeability did not differ either between experimental and control groups or between graft types. Our results support the conclusion that osteochondral allografts can be stored for as many as 14 days without significantly affecting the results of the procedure.

  19. A Hydrogel-Mineral Composite Scaffold for Osteochondral Interface Tissue Engineering

    PubMed Central

    Khanarian, Nora T.; Jiang, Jie; Wan, Leo Q.; Mow, Van C.

    2012-01-01

    Osteoarthritis is the leading cause of physical disability among Americans, and tissue engineered cartilage grafts have emerged as a promising treatment option for this debilitating condition. Currently, the formation of a stable interface between the cartilage graft and subchondral bone remains a significant challenge. This study evaluates the potential of a hybrid scaffold of hydroxyapatite (HA) and alginate hydrogel for the regeneration of the osteochondral interface. Specifically, the effects of HA on the response of chondrocytes were determined, focusing on changes in matrix production and mineralization, as well as scaffold mechanical properties over time. Additionally, the optimal chondrocyte population for interface tissue engineering was evaluated. It was observed that the HA phase of the composite scaffold promoted the formation of a proteoglycan- and type II collagen–rich matrix when seeded with deep zone chondrocytes. More importantly, the elevated biosynthesis translated into significant increases in both compressive and shear moduli relative to the mineral-free control. Presence of HA also promoted chondrocyte hypertrophy and type X collagen deposition. These results demonstrate that the hydrogel–calcium phosphate composite supported the formation of a calcified cartilage-like matrix and is a promising scaffold design for osteochondral interface tissue engineering. PMID:21919797

  20. Viral Inactivation of Human Osteochondral Grafts with Methylene Blue and Light

    PubMed Central

    Zhao, Zhixing; Call, Gazell M.; Gao, Jizong; Yao, Jian Q.

    2014-01-01

    Objective: Cartilage injury is one of the most common disorders of synovial joints. Fresh osteochondral allografts are becoming a standard treatment; however, they are supply constrained with a potential risk of disease transmission. There are no known virucidal processes available for osteochondral allografts and most methods presently available are detrimental to cartilage. Methylene blue light treatment has been shown to be successful in the literature for viral inactivation of fresh frozen plasma. The purpose of this study was to determine the capacity of methylene blue light treatment to inactivate a panel of clinically relevant viruses inoculated onto osteochondral allografts. Design: Osteochondral grafts recovered from human cadaveric knees were inoculated with one of the following viruses: bovine viral diarrhea virus (BVDV), hepatitis A virus (HAV), human immunodeficiency virus type 1 (HIV-1), porcine parvovirus (PPV), and pseudorabies virus (PrV). The samples were processed through a methylene blue light treatment, which consisted of an initial soak in nonilluminated circulating methylene blue at ambient temperature, followed by light exposure with circulating methylene blue at cool temperatures. The final titer was compared with the recovery control for the viral log reduction. Results: HIV-1, BVDV, and PrV were reduced to nondetectable levels while HAV and PPV were reduced by 3.1 and 5.6 logs, respectively. Conclusions: The methylene blue light treatment was effective in reducing (a) enveloped DNA and RNA viruses to nondetectable levels and (b) nonenveloped DNA and RNA viruses of inoculated human osteochondral grafts by 3.1 to 5.6 logs. This study demonstrates the first practical method for significantly reducing viral load in osteochondral implants. PMID:26069682

  1. Osteochondral tissue engineering: scaffolds, stem cells and applications

    PubMed Central

    Nooeaid, Patcharakamon; Salih, Vehid; Beier, Justus P; Boccaccini, Aldo R

    2012-01-01

    Osteochondral tissue engineering has shown an increasing development to provide suitable strategies for the regeneration of damaged cartilage and underlying subchondral bone tissue. For reasons of the limitation in the capacity of articular cartilage to self-repair, it is essential to develop approaches based on suitable scaffolds made of appropriate engineered biomaterials. The combination of biodegradable polymers and bioactive ceramics in a variety of composite structures is promising in this area, whereby the fabrication methods, associated cells and signalling factors determine the success of the strategies. The objective of this review is to present and discuss approaches being proposed in osteochondral tissue engineering, which are focused on the application of various materials forming bilayered composite scaffolds, including polymers and ceramics, discussing the variety of scaffold designs and fabrication methods being developed. Additionally, cell sources and biological protein incorporation methods are discussed, addressing their interaction with scaffolds and highlighting the potential for creating a new generation of bilayered composite scaffolds that can mimic the native interfacial tissue properties, and are able to adapt to the biological environment. PMID:22452848

  2. Optical Clearing in Collagen- and Proteoglycan-Rich Osteochondral Tissues

    PubMed Central

    Neu, Corey P.; Novak, Tyler; Gilliland, Kateri Fites; Marshall, Peter; Calve, Sarah

    2014-01-01

    Objective Recent developments in optical clearing and microscopy technology have enabled the imaging of intact tissues at the millimeter scale to characterize cells via fluorescence labeling. While these techniques have facilitated the three-dimensional cellular characterization within brain and heart, study of dense connective tissues of the musculoskeletal system have been largely unexplored. Here, we quantify how optical clearing impacted the cell and tissue morphology of collagen-, proteoglycan-, and mineral-rich cartilage and bone from the articulating knee joint. Methods Water-based fructose solutions were used for optical clearing of bovine osteochondral tissues, followed by imaging with transmission and confocal microscopy. To confirm preservation of tissue structure during the clearing process, samples were mechanically tested in unconfined compression and visualized by cryoSEM. Results Optical clearing enhanced light transmission through cartilage, but not subchondral bone regions. Fluorescent staining and immunolabeling was preserved through sample preparations, enabling imaging to cartilage depths 5 times deeper than previously reported, limited only by the working distance of the microscope objective. Chondrocyte volume remained unchanged in response to, and upon the reversal, of clearing. Equilibrium modulus increased in cleared samples, and was attributed to exchange of interstitial fluid with the more viscous fructose solution, but returned to control levels upon unclearing. In addition, cryoSEM-based analysis of cartilage showed no ultrastructural changes. Conclusion We anticipate large-scale microscopy of diverse connective tissues will enable the study of intact, three-dimensional interfaces (e.g. osteochondral) and cellular connectivity as a function of development, disease, and regeneration, which have been previously hindered by specimen opacity. PMID:25454370

  3. Advancements in Orthopedic Intervention: Retrograde Drilling and Bone Grafting of Osteochondral Lesions of the Knee Using Magnetic Resonance Imaging Guidance

    SciTech Connect

    Seebauer, Christian J.; Bail, Hermann J.; Rump, Jens C. Walter, Thula Teichgraeber, Ulf K. M.

    2010-12-15

    Computer-assisted surgery is currently a novel challenge for surgeons and interventional radiologists. Magnetic resonance imaging (MRI)-guided procedures are still evolving. In this experimental study, we describe and assess an innovative passive-navigation method for MRI-guided treatment of osteochondritis dissecans of the knee. A navigation principle using a passive-navigation device was evaluated in six cadaveric knee joint specimens for potential applicability in retrograde drilling and bone grafting of osteochondral lesions using MRI guidance. Feasibility and accuracy were evaluated in an open MRI scanner (1.0 T Philips Panorama HFO MRI System). Interactive MRI navigation allowed precise drilling and bone grafting of osteochondral lesions of the knee. All lesions were hit with an accuracy of 1.86 mm in the coronal plane and 1.4 mm the sagittal plane. Targeting of all lesions was possible with a single drilling. MRI allowed excellent assessment of correct positioning of the cancellous bone cylinder during bone grafting. The navigation device and anatomic structures could be clearly identified and distinguished throughout the entire drilling procedure. MRI-assisted navigation method using a passive navigation device is feasible for the treatment of osteochondral lesions of the knee under MRI guidance and allows precise and safe drilling without exposure to ionizing radiation. This method may be a viable alternative to other navigation principles, especially for pediatric and adolescent patients. This MRI-navigated method is also potentially applicable in many other MRI-guided interventions.

  4. Human umbilical cord mesenchymal stromal cells in a sandwich approach for osteochondral tissue engineering

    PubMed Central

    Wang, Limin; Zhao, Liang; Detamore, Michael S.

    2013-01-01

    Cell sources and tissue integration between cartilage and bone regions are critical to successful osteochondral regeneration. In this study, human umbilical cord mesenchymal stromal cells (hUCMSCs), derived from Wharton’s jelly, were introduced to the field of osteochondral tissue engineering and a new strategy for osteochondral integration was developed by sandwiching a layer of cells between chondrogenic and osteogenic constructs before suturing them together. Specifically, hUCMSCs were cultured in biodegradable poly-l-lactic acid scaffolds for 3 weeks in either chondrogenic or osteogenic medium to differentiate cells toward cartilage or bone lineages, respectively. A highly concentrated cell solution containing undifferentiated hUCMSCs was pasted onto the surface of the bone layer at week 3 and the two layers were then sutured together to form an osteochondral composite for another 3 week culture period. Chondrogenic and osteogenic differentiation was initiated during the first 3 weeks, as evidenced by the expression of type II collagen and runt-related transcription factor 2 genes, respectively, and continued with the increase of extracellular matrix during the last 3 weeks. Histological and immunohistochemical staining, such as for glycosaminoglycans, type I collagen and calcium, revealed better integration and transition of these matrices between two layers in the composite group containing sandwiched cells compared to other control composites. These results suggest that hUCMSCs may be a suitable cell source for osteochondral regeneration, and the strategy of sandwiching cells between two layers may facilitate scaffold and tissue integration. PMID:21953869

  5. Mechanical evaluation of a tissue-engineered zone of calcification in a bone-hydrogel osteochondral construct.

    PubMed

    Hollenstein, Jérôme; Terrier, Alexandre; Cory, Esther; Chen, Albert C; Sah, Robert L; Pioletti, Dominique P

    2015-01-01

    The objective of this study was to test the hypothesis that mechanical properties of artificial osteochondral constructs can be improved by a tissue-engineered zone of calcification (teZCC) at the bone-hydrogel interface. Experimental push-off tests were performed on osteochondral constructs with or without a teZCC. In parallel, a numerical model of the osteochondral defect treatment was developed and validated against experimental results. Experimental results showed that the shear strength at the bone-hydrogel interface increased by 100% with the teZCC. Numerical predictions of the osteochondral defect treatment showed that the shear stress at the bone-hydrogel interface was reduced with the teZCC. We conclude that a teZCC in osteochondral constructs can provide two improvements. First, it increases the strength of the bone-hydrogel interface and second, it reduces the stress at this interface.

  6. Mechanical loading regulates human MSC differentiation in a multi-layer hydrogel for osteochondral tissue engineering.

    PubMed

    Steinmetz, Neven J; Aisenbrey, Elizabeth A; Westbrook, Kristofer K; Qi, H Jerry; Bryant, Stephanie J

    2015-07-01

    A bioinspired multi-layer hydrogel was developed for the encapsulation of human mesenchymal stem cells (hMSCs) as a platform for osteochondral tissue engineering. The spatial presentation of biochemical cues, via incorporation of extracellular matrix analogs, and mechanical cues, via both hydrogel crosslink density and externally applied mechanical loads, were characterized in each layer. A simple sequential photopolymerization method was employed to form stable poly(ethylene glycol)-based hydrogels with a soft cartilage-like layer of chondroitin sulfate and low RGD concentrations, a stiff bone-like layer with high RGD concentrations, and an intermediate interfacial layer. Under a compressive load, the variation in hydrogel stiffness within each layer produced high strains in the soft cartilage-like layer, low strains in the stiff bone-like layer, and moderate strains in the interfacial layer. When hMSC-laden hydrogels were cultured statically in osteochondral differentiation media, the local biochemical and matrix stiffness cues were not sufficient to spatially guide hMSC differentiation after 21 days. However dynamic mechanical stimulation led to differentially high expression of collagens with collagen II in the cartilage-like layer, collagen X in the interfacial layer and collagen I in the bone-like layer and mineral deposits localized to the bone layer. Overall, these findings point to external mechanical stimulation as a potent regulator of hMSC differentiation toward osteochondral cellular phenotypes. PMID:25900444

  7. Mechanical loading regulates human MSC differentiation in a multi-layer hydrogel for osteochondral tissue engineering.

    PubMed

    Steinmetz, Neven J; Aisenbrey, Elizabeth A; Westbrook, Kristofer K; Qi, H Jerry; Bryant, Stephanie J

    2015-07-01

    A bioinspired multi-layer hydrogel was developed for the encapsulation of human mesenchymal stem cells (hMSCs) as a platform for osteochondral tissue engineering. The spatial presentation of biochemical cues, via incorporation of extracellular matrix analogs, and mechanical cues, via both hydrogel crosslink density and externally applied mechanical loads, were characterized in each layer. A simple sequential photopolymerization method was employed to form stable poly(ethylene glycol)-based hydrogels with a soft cartilage-like layer of chondroitin sulfate and low RGD concentrations, a stiff bone-like layer with high RGD concentrations, and an intermediate interfacial layer. Under a compressive load, the variation in hydrogel stiffness within each layer produced high strains in the soft cartilage-like layer, low strains in the stiff bone-like layer, and moderate strains in the interfacial layer. When hMSC-laden hydrogels were cultured statically in osteochondral differentiation media, the local biochemical and matrix stiffness cues were not sufficient to spatially guide hMSC differentiation after 21 days. However dynamic mechanical stimulation led to differentially high expression of collagens with collagen II in the cartilage-like layer, collagen X in the interfacial layer and collagen I in the bone-like layer and mineral deposits localized to the bone layer. Overall, these findings point to external mechanical stimulation as a potent regulator of hMSC differentiation toward osteochondral cellular phenotypes.

  8. Evaluation of novel in situ synthesized nano-hydroxyapatite/collagen/alginate hydrogels for osteochondral tissue engineering.

    PubMed

    Zheng, Li; Jiang, Xianfang; Chen, Xuening; Fan, Hongsong; Zhang, Xingdong

    2014-12-01

    Collagen hydrogel has been widely used for osteochondral repair, but its mechanical properties cannot meet the requirements of clinical application. Previous studies have shown that the addition of either polysaccharide or inorganic particles could reinforce the polymer matrix. However, their synergic effects on collagen-based hydrogel have seldom been studied, and the potential application of triple-phased composite gel in osteochondral regeneration has not been reported. In this study, nano-hydroxyapatite (nano-HA) reinforced collagen-alginate hydrogel (nHCA) was prepared by the in situ synthesis of nano-HA in collagen gel followed by the addition of alginate and Ca(2+). The properties of triple-phased nHCA hydrogel were studied and compared with pure collagen and biphasic gels, and the triple-phased composite of collagen-alginate-HA gels showed a superiority in not only mechanical but also biological features, as evidenced by the enhanced tensile and compressive modulus, higher cell viability, faster cell proliferation and upregulated hyaline cartilage markers. In addition, it was found that the synthesis process could also affect the properties of the triple-phased composite, compared to blend-mixing HCA. The in situ-synthesized nHCA hydrogel showed an enhanced tensile modulus, as well as enhanced biological features compared with HCA. Our study demonstrated that the nHCA composite hydrogel holds promise in osteochondral regeneration. The addition of alginate and nano-HA contribute to the increase in both mechanical and biological properties. This study may provide a valuable reference for the design of an appropriate composite scaffold for osteochondral tissue engineering.

  9. Multiphasic construct studied in an ectopic osteochondral defect model

    PubMed Central

    Jeon, June E.; Vaquette, Cédryck; Theodoropoulos, Christina; Klein, Travis J.; Hutmacher, Dietmar W.

    2014-01-01

    In vivo osteochondral defect models predominantly consist of small animals, such as rabbits. Although they have an advantage of low cost and manageability, their joints are smaller and more easily healed compared with larger animals or humans. We hypothesized that osteochondral cores from large animals can be implanted subcutaneously in rats to create an ectopic osteochondral defect model for routine and high-throughput screening of multiphasic scaffold designs and/or tissue-engineered constructs (TECs). Bovine osteochondral plugs with 4 mm diameter osteochondral defect were fitted with novel multiphasic osteochondral grafts composed of chondrocyte-seeded alginate gels and osteoblast-seeded polycaprolactone scaffolds, prior to being implanted in rats subcutaneously with bone morphogenic protein-7. After 12 weeks of in vivo implantation, histological and micro-computed tomography analyses demonstrated that TECs are susceptible to mineralization. Additionally, there was limited bone formation in the scaffold. These results suggest that the current model requires optimization to facilitate robust bone regeneration and vascular infiltration into the defect site. Taken together, this study provides a proof-of-concept for a high-throughput osteochondral defect model. With further optimization, the presented hybrid in vivo model may address the growing need for a cost-effective way to screen osteochondral repair strategies before moving to large animal preclinical trials. PMID:24694896

  10. Osteochondral Tissue Regeneration Through Polymeric Delivery of DNA Encoding for the SOX Trio and RUNX2

    PubMed Central

    Needham, Clark J.; Shah, Sarita R.; Dahlin, Rebecca L.; Kinard, Lucas A.; Lam, Johnny; Watson, Brendan M.; Lu, Steven; Kasper, F. Kurtis; Mikos, Antonios G.

    2014-01-01

    Native osteochondral repair is often inadequate due to the inherent properties of the tissue and current clinical repair strategies can result in healing with a limited lifespan and donor site morbidity. This work investigates the use of polymeric gene therapy to address this problem by delivering DNA encoding for transcription factors complexed with the branched poly(ethylenimine)-hyaluronic acid (bPEI-HA) delivery vector via a porous oligo[poly(ethylene glycol) fumarate] (OPF) hydrogel scaffold. To evaluate the potential of this approach, a bilayered scaffold mimicking native osteochondral tissue organization was loaded with DNA/bPEI-HA complexes. Next, bilayered implants either unloaded or loaded in a spatial fashion with bPEI-HA and DNA encoding for either Runt-related transcription factor 2 (RUNX2) or SRY (sex determining region Y)-box 5, 6, and 9 (the SOX trio), to generate bone and cartilage tissues respectively, were fabricated and implanted in a rat osteochondral defect. At 6 weeks post-implantation, micro-computed tomography (micro-CT) analysis and histological scoring were performed on the explants to evaluate the quality and quantity of tissue repair in each group. The incorporation of DNA encoding for RUNX2 in the bone layer of these scaffolds significantly increased bone growth. Additionally, a spatially loaded combination of RUNX2 and SOX trio DNA loading significantly improved healing relative to empty hydrogels or either factor alone. Finally, the results of this study suggest that subchondral bone formation is necessary for correct cartilage healing. PMID:24854956

  11. Cell-laden biphasic scaffolds with anisotropic structure for the regeneration of osteochondral tissue.

    PubMed

    Schütz, Kathleen; Despang, Florian; Lode, Anja; Gelinsky, Michael

    2016-05-01

    Sufficient treatment of chondral and osteochondral defects to restore function of the respective tissue remains challenging in regenerative medicine. Biphasic scaffolds that mimic properties of bone and cartilage are appropriate to regenerate both tissues at the same time. The present study describes the development of biphasic, but monolithic scaffolds based on alginate, which are suitable for embedding of living cells in the chondral part. Scaffolds are fabricated under sterile and cell-compatible conditions according to the principle of diffusion-controlled, directed ionotropic gelation, which leads to the formation of channel-like, parallel aligned pores, running through the whole length of the biphasic constructs. The synthesis process leads to an anisotropic structure, as it is found in many natural tissues. The two different layers of the scaffolds are characterized by different microstructure and mechanical properties which provide a suitable environment for cells to form the respective tissue. Human chondrocytes and human mesenchymal stem cells were embedded within the chondral layer of the biphasic scaffolds during hydrogel formation and their chondrogenic (re)differentiation was successfully induced. Whereas viability of non-induced human mesenchymal stem cells decreased during culture, cell viability of human chondrocytes and chondrogenically induced human mesenchymal stem cells remained high within the scaffolds over the whole culture period of 3 weeks, demonstrating successful fabrication of cell-laden centimetre-scaled constructs for potential application in regenerative treatment of osteochondral defects. Copyright © 2014 John Wiley & Sons, Ltd.

  12. Effect of porosities of bilayered porous scaffolds on spontaneous osteochondral repair in cartilage tissue engineering

    PubMed Central

    Dong, Jian; Ding, Jiandong

    2015-01-01

    Poly(lactide-co-glycolide)-bilayered scaffolds with the same porosity or different ones on the two layers were fabricated, and the porosity effect on in vivo repairing of the osteochondral defect was examined in a comparative way for the first time. The constructs of scaffolds and bone marrow-derived mesenchymal stem cells were implanted into pre-created osteochondral defects in the femoral condyle of New Zealand white rabbits. After 12 weeks, all experimental groups exhibited good cartilage repairing according to macroscopic appearance, cross-section view, haematoxylin and eosin staining, toluidine blue staining, immunohistochemical staining and real-time polymerase chain reaction of characteristic genes. The group of 92% porosity in the cartilage layer and 77% porosity in the bone layer resulted in the best efficacy, which was understood by more biomechanical mimicking of the natural cartilage and subchondral bone. This study illustrates unambiguously that cartilage tissue engineering allows for a wide range of scaffold porosity, yet some porosity group is optimal. It is also revealed that the biomechanical matching with the natural composite tissue should be taken into consideration in the design of practical biomaterials, which is especially important for porosities of a multi-compartment scaffold concerning connected tissues. PMID:26813511

  13. Bioglass®/chitosan-polycaprolactone bilayered composite scaffolds intended for osteochondral tissue engineering.

    PubMed

    Yao, Qingqing; Nooeaid, Patcharakamon; Detsch, Rainer; Roether, Judith A; Dong, Yanming; Goudouri, Ourania-Menti; Schubert, Dirk W; Boccaccini, Aldo R

    2014-12-01

    Polymer-coated 45S5 Bioglass(®) (BG)/chitosan-polycaprolactone (BG/CS-PCL) bilayered composite scaffolds were prepared via foam replication and freeze-drying techniques for application in osteochondral tissue engineering. The CS-PCL coated and uncoated BG scaffolds were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The mechanical properties of the coated scaffolds were significantly improved in comparison to uncoated scaffolds. The bioactivity and biodegradation behavior of scaffolds were studied in simulated body fluid (SBF) for up to 28 days. The interface between the BG scaffold and the polymer coating layer was observed by SEM and a suitable interpenetration of the polymer into the scaffold struts was found. The effects of coated and uncoated BG scaffolds on MG-63 osteoblast-like cells were evaluated by cell viability, adhesion and proliferation.

  14. Simultaneous Osteoperiosteal Autologous Iliac Crest Graft and Lateral Meniscus Allograft Transplantation for Osteochondral Lesion with Bony Defect and Lateral Discoid Meniscus Tear.

    PubMed

    Lee, Dhong Won; Kim, Jin Goo; Ha, Jeong Ku; Kim, Woo Jong

    2016-06-01

    The optimal treatment for combined osteochondritis dissecans (OCD) with considerable bony defect of the lateral femoral condyle (LFC) and torn discoid lateral meniscus is unclear. We present a case of a 15-year-old female who was a gymnast and had a large OCD lesion in the LFC combined with deficiency of the lateral meniscus. The patient underwent the "one-step" technique of osteoperiosteal autologous iliac crest graft and lateral meniscus allograft transplantation after a failure of meniscectomy with repair at another hospital. Twenty-four months postoperatively, clinical results were significantly improved. Follow-up imaging tests and second-look arthroscopy showed well incorporated structured bone graft and fibrous cartilage regeneration as well as stabilized lateral meniscus allograft. She could return to her sport without any pain or swelling. This "one-step" surgical technique is worth considering as a joint salvage procedure for massive OCD lesions with torn discoid lateral meniscus. PMID:27274475

  15. Simultaneous Osteoperiosteal Autologous Iliac Crest Graft and Lateral Meniscus Allograft Transplantation for Osteochondral Lesion with Bony Defect and Lateral Discoid Meniscus Tear.

    PubMed

    Lee, Dhong Won; Kim, Jin Goo; Ha, Jeong Ku; Kim, Woo Jong

    2016-06-01

    The optimal treatment for combined osteochondritis dissecans (OCD) with considerable bony defect of the lateral femoral condyle (LFC) and torn discoid lateral meniscus is unclear. We present a case of a 15-year-old female who was a gymnast and had a large OCD lesion in the LFC combined with deficiency of the lateral meniscus. The patient underwent the "one-step" technique of osteoperiosteal autologous iliac crest graft and lateral meniscus allograft transplantation after a failure of meniscectomy with repair at another hospital. Twenty-four months postoperatively, clinical results were significantly improved. Follow-up imaging tests and second-look arthroscopy showed well incorporated structured bone graft and fibrous cartilage regeneration as well as stabilized lateral meniscus allograft. She could return to her sport without any pain or swelling. This "one-step" surgical technique is worth considering as a joint salvage procedure for massive OCD lesions with torn discoid lateral meniscus.

  16. Simultaneous Osteoperiosteal Autologous Iliac Crest Graft and Lateral Meniscus Allograft Transplantation for Osteochondral Lesion with Bony Defect and Lateral Discoid Meniscus Tear

    PubMed Central

    Lee, Dhong Won; Ha, Jeong Ku; Kim, Woo Jong

    2016-01-01

    The optimal treatment for combined osteochondritis dissecans (OCD) with considerable bony defect of the lateral femoral condyle (LFC) and torn discoid lateral meniscus is unclear. We present a case of a 15-year-old female who was a gymnast and had a large OCD lesion in the LFC combined with deficiency of the lateral meniscus. The patient underwent the "one-step" technique of osteoperiosteal autologous iliac crest graft and lateral meniscus allograft transplantation after a failure of meniscectomy with repair at another hospital. Twenty-four months postoperatively, clinical results were significantly improved. Follow-up imaging tests and second-look arthroscopy showed well incorporated structured bone graft and fibrous cartilage regeneration as well as stabilized lateral meniscus allograft. She could return to her sport without any pain or swelling. This "one-step" surgical technique is worth considering as a joint salvage procedure for massive OCD lesions with torn discoid lateral meniscus. PMID:27274475

  17. Hierarchical Structure of Articular Bone-Cartilage Interface and Its Potential Application for Osteochondral Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Bian, Weiguo; Qin, Lian; Li, Dichen; Wang, Jin; Jin, Zhongmin

    2010-09-01

    The artificial biodegradable osteochondral construct is one of mostly promising lifetime substitute in the joint replacement. And the complex hierarchical structure of natural joint is important in developing the osteochondral construct. However, the architecture features of the interface between cartilage and bone, in particular those at the micro-and nano-structural level, remain poorly understood. This paper investigates these structural data of the cartilage-bone interface by micro computerized tomography (μCT) and Scanning Electron Microscope (SEM). The result of μCT shows that important bone parameters and the density of articular cartilage are all related to the position in the hierarchical structure. The conjunctions of bone and cartilage were defined by SEM. All of the study results would be useful for the design of osteochondral construct further manufactured by nano-tech. A three-dimensional model with gradient porous structure is constructed in the environment of Pro/ENGINEERING software.

  18. Osteochondral lesion located at the lateral femoral condyle reconstructed by the transplantation of tissue-engineered cartilage in combination with a periosteum with bone block: a case report.

    PubMed

    Adachi, Nobuo; Ochi, Mitsuo; Uchio, Yuji; Iwasa, Junji; Furukawa, Seiji; Deie, Masataka

    2004-09-01

    We report herein the successful treatment of a patient with an osteochondral defect extending to the edge of the lateral femoral condyle by transplantation of tissue-engineered cartilage made ex vivo using atelocollagen gel covered by periosteum with a bone block to reconstruct the normal contour of the femoral condyle.

  19. Advancement of the Subchondral Bone Plate in Translational Models of Osteochondral Repair: Implications for Tissue Engineering Approaches.

    PubMed

    Orth, Patrick; Madry, Henning

    2015-12-01

    Subchondral bone plate advancement is of increasing relevance for translational models of osteochondral repair in tissue engineering (TE). Especially for therapeutic TE approaches, a basic scientific knowledge of its chronological sequence, possible etiopathogenesis, and clinical implications are indispensable. This review summarizes the knowledge on this topic gained from a total of 31 translational investigations, including 1009 small and large animals. Experimental data indicate that the advancement of the subchondral bone plate frequently occurs during the spontaneous repair of osteochondral defects and following established articular cartilage repair approaches for chondral lesions such as marrow stimulation and TE-based strategies such as autologous chondrocyte implantation. Importantly, this subchondral bone reaction proceeds in a defined chronological and spatial pattern, reflecting both endochondral ossification and intramembranous bone formation. Subchondral bone plate advancement arises earlier in small animals and defects, but is more pronounced at the long term in large animals. Possible etiopathologies comprise a disturbed subchondral bone/articular cartilage crosstalk and altered biomechanical conditions or neovascularization. Of note, no significant correlation was found so far between subchondral bone plate advancement and articular cartilage repair. This evidence from translational animal models adverts to an increasing awareness of this previously underestimated pathology. Future research will shed more light on the advancement of the subchondral bone plate in TE models of cartilage repair. PMID:26066580

  20. Advancement of the Subchondral Bone Plate in Translational Models of Osteochondral Repair: Implications for Tissue Engineering Approaches.

    PubMed

    Orth, Patrick; Madry, Henning

    2015-12-01

    Subchondral bone plate advancement is of increasing relevance for translational models of osteochondral repair in tissue engineering (TE). Especially for therapeutic TE approaches, a basic scientific knowledge of its chronological sequence, possible etiopathogenesis, and clinical implications are indispensable. This review summarizes the knowledge on this topic gained from a total of 31 translational investigations, including 1009 small and large animals. Experimental data indicate that the advancement of the subchondral bone plate frequently occurs during the spontaneous repair of osteochondral defects and following established articular cartilage repair approaches for chondral lesions such as marrow stimulation and TE-based strategies such as autologous chondrocyte implantation. Importantly, this subchondral bone reaction proceeds in a defined chronological and spatial pattern, reflecting both endochondral ossification and intramembranous bone formation. Subchondral bone plate advancement arises earlier in small animals and defects, but is more pronounced at the long term in large animals. Possible etiopathologies comprise a disturbed subchondral bone/articular cartilage crosstalk and altered biomechanical conditions or neovascularization. Of note, no significant correlation was found so far between subchondral bone plate advancement and articular cartilage repair. This evidence from translational animal models adverts to an increasing awareness of this previously underestimated pathology. Future research will shed more light on the advancement of the subchondral bone plate in TE models of cartilage repair.

  1. Dynamic regulation of bone morphogenetic proteins in engineered osteochondral constructs by biomechanical stimulation.

    PubMed

    Nam, Jin; Perera, Priyangi; Rath, Bjoern; Agarwal, Sudha

    2013-03-01

    Osteochondral tissue-engineered grafts are proposed to hold greater potential to repair/regenerate damaged cartilage through enhanced biochemical and mechanical interactions with underlying subchondral bone as compared to simple engineered cartilage. Additionally, biomechanical stimulation of articular chondrocytes (ACs) or osteoblasts (OBs) was shown to induce greater morphogenesis of the engineered tissues composed of these cells. In this report, to define the advantages of biomechanical stimulation to osteochondral grafts for tissue engineering, we examined whether (1) ACs and OBs in three-dimensional (3D) osteochondral constructs support functional development of each other at the molecular level, and (2) biomechanical stimulation of osteochondral constructs further promotes the regenerative potential of such grafts. Various configurations of cell/scaffold assemblies, including chondral, osseous, and osteochondral constructs, were engineered with mechano-responsive electrospun poly(ɛ-caprolactone) scaffolds. These constructs were subjected to either static or dynamic (10% cyclic compressive strain at 1 Hz for 3 h/day) culture conditions for 2 weeks. The expression of bone morphogenetic proteins (BMPs) was examined to assess the regenerative potential of each treatment on the cells. Biomechanical stimulation augmented a marked upregulation of Bmp2, Bmp6, and Bmp7 as well as downregulation of BMP antagonist, Bmp3, in a time-specific manner in the ACs and OBs of 3D osteochondral constructs. More importantly, the presence of biomechanically stimulated OBs was especially crucial for the induction of Bmp6 in ACs, a BMP required for chondrocytic growth and differentiation. Biomechanical stimulation led to enhanced tissue morphogenesis possibly through this BMP regulation, evident by the improved effective compressive modulus of the osteochondral constructs (710 kPa of dynamic culture vs. 280 kPa of static culture). Similar BMP regulation was observed in the

  2. Treatment of osteochondral defects in the rabbit's knee joint by implantation of allogeneic mesenchymal stem cells in fibrin clots.

    PubMed

    Berninger, Markus T; Wexel, Gabriele; Rummeny, Ernst J; Imhoff, Andreas B; Anton, Martina; Henning, Tobias D; Vogt, Stephan

    2013-01-01

    The treatment of osteochondral articular defects has been challenging physicians for many years. The better understanding of interactions of articular cartilage and subchondral bone in recent years led to increased attention to restoration of the entire osteochondral unit. In comparison to chondral lesions the regeneration of osteochondral defects is much more complex and a far greater surgical and therapeutic challenge. The damaged tissue does not only include the superficial cartilage layer but also the subchondral bone. For deep, osteochondral damage, as it occurs for example with osteochondrosis dissecans, the full thickness of the defect needs to be replaced to restore the joint surface (1). Eligible therapeutic procedures have to consider these two different tissues with their different intrinsic healing potential (2). In the last decades, several surgical treatment options have emerged and have already been clinically established (3-6). Autologous or allogeneic osteochondral transplants consist of articular cartilage and subchondral bone and allow the replacement of the entire osteochondral unit. The defects are filled with cylindrical osteochondral grafts that aim to provide a congruent hyaline cartilage covered surface (3,7,8). Disadvantages are the limited amount of available grafts, donor site morbidity (for autologous transplants) and the incongruence of the surface; thereby the application of this method is especially limited for large defects. New approaches in the field of tissue engineering opened up promising possibilities for regenerative osteochondral therapy. The implantation of autologous chondrocytes marked the first cell based biological approach for the treatment of full-thickness cartilage lesions and is now worldwide established with good clinical results even 10 to 20 years after implantation (9,10). However, to date, this technique is not suitable for the treatment of all types of lesions such as deep defects involving the subchondral

  3. Soft Tissue Augmentation with Silk Composite Graft

    PubMed Central

    Park, Yong-Tae; Kweon, Hae Yong; Kim, Seong-Gon

    2014-01-01

    Purpose: The objective of this study was to evaluate the interaction between 4-hexylresorcinol (4HR) and antibody as that affects the performance of a silk-4HR combination graft for soft tissue augmentation in an animal model. Methods: The silk graft materials consisted of four types: silk+10% tricalcium phosphate (TCP) (ST0), silk+10% TCP+1% 4HR (ST1), silk+10% TCP+3% 4HR (ST3), and silk+10% TCP+6% 4-HR (ST6). The antibody binding assay tested the 4HR effect and scanning electron microscopic (SEM) exam was done for silk grafts. The animal experiment used a subcutaneous pocket mouse model. The graft – SH0 or SH1 or SH3 or SH6 – was placed in a subcutaneous pocket. The animals were killed at one, two, and four weeks, postoperatively. The specimens were subjected to histological analysis and lysozyme assay. Results: Groups with 4HR applied showed lower antibody binding affinity to antigen compared to groups without 4HR. In the SEM examination, there was no significant difference among groups. Histological examinations revealed many foreign body giant cells in ST0 and ST1 group at four weeks postoperatively. Both ST3 and ST6 groups developed significantly lower levels of giant cell values compared to ST0 and ST1 groups (P <0.001) at four weeks postoperatively. In the lysozyme assay, the ST1 and ST3 groups showed denser signals than the other groups. Conclusion: 4HR combined silk implants resulted in high levels of vascular and connective tissue regeneration. PMID:27489833

  4. Osteochondral autograft transplantation for osteochondritis dissecans of the capitellum in nonthrowing athletes.

    PubMed

    Tsuda, Eiichi; Ishibashi, Yasuyuki; Sato, Hideki; Yamamoto, Yuji; Toh, Satoshi

    2005-10-01

    In this report, we present the cases of 3 nonthrowing athletes with osteochondritis dissecans of the capitellum. Preoperatively, they complained of elbow pain during rhythmic gymnastics, table tennis, and basketball, respectively. Magnetic resonance imaging showed a completely separated osteochondral fragment or a full-thickness cartilage defect. All 3 patients were treated with transplantation of an osteochondral autograft harvested from the lateral femoral condyle. They returned fully to their sports activities within 6 months of surgery. The continuity of the cartilage layer between the osteochondral graft and the capitellum was shown on magnetic resonance images taken at 12 months postoperatively. We believe that osteochondral autograft transplantation provides successful results for nonthrowing athletes with end-stage osteochondritis dissecans of the capitellum.

  5. Treatment of gingival recession in two surgical stages: Free gingival graft and connective tissue grafting.

    PubMed

    Henriques, Paulo Sergio Gomes; Nunes, Marcelo Pereira; Pelegrine, Andre Antonio

    2011-01-01

    This report describes a clinical case of severe Miller Class II gingival recession treated by two stages of surgery that combined a free gingival graft and connective tissue grafting. First, a free gingival graft (FGG) was performed to obtain an adequate keratinized tissue level. Three months later, a connective tissue graft (CTG) was performed to obtain root coverage. The results indicated that the FGG allows for a gain in the keratinized tissue level and the CTG allows for root coverage with decreased recession level after 16 months. Therefore, for this type of specific gingival recession, the combination of FGG and CTG can be used.

  6. Cell-free multi-layered collagen-based scaffolds demonstrate layer specific regeneration of functional osteochondral tissue in caprine joints.

    PubMed

    Levingstone, Tanya J; Ramesh, Ashwanth; Brady, Robert T; Brama, Pieter A J; Kearney, Clodagh; Gleeson, John P; O'Brien, Fergal J

    2016-05-01

    Developing repair strategies for osteochondral tissue presents complex challenges due to its interfacial nature and complex zonal structure, consisting of subchondral bone, intermediate calcified cartilage and the superficial cartilage regions. In this study, the long term ability of a multi-layered biomimetic collagen-based scaffold to repair osteochondral defects is investigated in a large animal model: namely critical sized lateral trochlear ridge (TR) and medial femoral condyle (MC) defects in the caprine stifle joint. The study thus presents the first data in a clinically applicable large animal model. Scaffold fixation and early integration was demonstrated at 2 weeks post implantation. Macroscopic analysis demonstrated improved healing in the multi-layered scaffold group compared to empty defects and a market approved synthetic polymer osteochondral scaffold groups at 6 and 12 months post implantation. Radiological analysis demonstrated superior subchondral bone formation in both defect sites in the multi-layered scaffold group as early as 3 months, with complete regeneration of subchondral bone by 12 months. Histological analysis confirmed the formation of well-structured subchondral trabecular bone and hyaline-like cartilage tissue in the multi-layered scaffold group by 12 months with restoration of the anatomical tidemark. Demonstration of improved healing following treatment with this natural polymer scaffold, through the recruitment of host cells with no requirement for pre-culture, shows the potential of this device for the treatment of patients presenting with osteochondal lesions.

  7. Graft versus host reaction in tissue culture

    PubMed Central

    Ginsburg, H.

    1968-01-01

    Rat lymphocytes cultured on mouse embryo cell monolayers produced large pyroninophilic cells (LPC) which lysed the mouse cells. The LPC that developed on monolayers of any particular strain of mouse (originator monolayers) were tested, by transfer, for their ability to lyse monolayers of other mouse strains. The distribution of lysis among the various strains of mouse revealed a definite pattern of specificity. Analysis of the H-2 allelic complement of the mouse strains tested suggests that the lymphocytes were sensitized upon exposure to the mouse embryo monolayers against one or more of the antigens determined by the H-2 locus. The presence or absence of one or all of the antigens in other strains determined whether monolayers of these strains were lysed completely, partially, or not at all. It was concluded that the cultures obtained are an in vitro reflection of the graft versus host immune reaction. It was produced in the tissue culture as a primary response by normal lymphocytes. ImagesFIG. 1FIG. 2FIG. 3-4FIG. 5-6FIG. 7-8 PMID:5656875

  8. Correction of infraorbital and malar deficiency using costal osteochondral graft along with orthognathic surgery in Crouzon syndrome.

    PubMed

    Song, Hyunsuk; Park, Myong Chul; Lee, Il Jae; Park, Dong Ha

    2014-09-01

    In syndromic craniosynostosis, such as Crouzon syndrome, midfacial hypoplasia can cause exophthalmos and concave facial profile. Though midfacial hypoplasia in Crouzon syndrome patients can be treated with midface advancement, known as a Le Fort II or Le Fort III osteotomy, such method can change nasal appearance and frequently fails to achieve class I occlusion after surgery. This report presents a case of an aesthetically and functionally successful midfacial augmentation using rib and cartilage graft along with orthognathic surgery (Le fort I and bilateral sagittal split ramus osteotomy) for patients with Crouzon syndrome. The patient was a 21-year-old male with Crouzon syndrome, who had undergone augmentation rhinoplasty 2 years ago. His main issues were midfacial retrusion and mild anterior open bite and cross bite and, furthermore, did not want any change in his nasal appearance. To augment midfacial volume, rib bone graft was inserted on the inferior orbital rim and costal cartilage graft was done on the zygomatic area. The costal osteocartilage was fixed with titanium screws. Additionally, Le Fort I osteotomy and bilateral sagittal split ramus osteotomy were done to treat the anterior open bite and cross bite. The maxillary segment was advanced 2 mm and posteriorly impacted 2.5 mm. Then, 5 mm of mandibular setback was done and the maxillomandibular segment was rotated clockwise. Finally, genioplasty with 5-mm advancement was done to compensate for the chin retrusion after performing the mandibular setback. The operation took 425 minutes and estimated blood loss was 500 mL. After 6 months since surgery, the patient had convex facial profile and class I occlusion. For the patient with mild midface hypoplasia, good nasal profile, and malocclusion, rib bone graft along with Le Fort I and bilateral sagittal ramus osteotomy can be a good surgical modality. PMID:25153066

  9. Platelet-rich plasma increases transforming growth factor-beta1 expression at graft-host interface following autologous osteochondral transplantation in a rabbit model

    PubMed Central

    Boakye, Lorraine A; Ross, Keir A; Pinski, John M; Smyth, Niall A; Haleem, Amgad M; Hannon, Charles P; Fortier, Lisa A; Kennedy, John G

    2015-01-01

    AIM: To explore the effect of platelet-rich plasma on protein expression patterns of transforming growth factor-beta1 (TGF-β1) in cartilage following autologous osteochondral transplantation (AOT) in a rabbit knee cartilage defect model. METHODS: Twelve New Zealand white rabbits received bilateral AOT. In each rabbit, one knee was randomized to receive an autologous platelet rich plasma (PRP) injection and the contralateral knee received saline injection. Rabbits were euthanized at 3, 6 and 12 wk post-operatively. Articular cartilage sections were stained with TGF-β1 antibody. Histological regions of interest (ROI) (left, right and center of the autologous grafts interfaces) were evaluated using MetaMorph. Percentage of chondrocytes positive for TGF-β1 was then assessed. RESULTS: Percentage of chondrocytes positive for TGF-β1 was higher in PRP treated knees for selected ROIs (left; P = 0.03, center; P = 0.05) compared to control and was also higher in the PRP group at each post-operative time point (P = 6.6 × 10-4, 3.1 × 10-4 and 7.3 × 10-3 for 3, 6 and 12 wk, respectively). TGF-β1 expression was higher in chondrocytes of PRP-treated knees (36% ± 29% vs 15% ± 18%) (P = 1.8 × 10-6) overall for each post-operative time point and ROI. CONCLUSION: Articular cartilage of rabbits treated with AOT and PRP exhibit increased TGF-β1 expression compared to those treated with AOT and saline. Our findings suggest that adjunctive PRP may increase TGF-β1 expression, which may play a role in the chondrogenic effect of PRP in vivo. PMID:26716092

  10. Osteochondral lesions of the talus: Current concept.

    PubMed

    Laffenêtre, O

    2010-09-01

    Osteochondral lesions of the talus (OTL) are among those injuries that we should not fail to recognize, especially following any type of hindfoot injury. They were thoroughly described 15 years ago in a round table session organized by Doré and Rosset for the Société orthopédique de l'Ouest. Their physiopathology has not yet been definitely determined, even though some of the pathogenic mechanisms are known. They are best characterized using the fractures, osteonecroses, geodes (FOG) radiological classification. Both their diagnosis and their surgical treatment remain a challenge to the orthopaedic surgeon: some basic surgical principles apply to all of the lesions, such as cartilage debridement and shaving of necrotic tissues, while others will be used depending on the location and size of the lesions as well as the surgeon's experience. Finally, no specific technique appears to be superior to the others. Arthroscopy appears to be the most effective procedure for lesions smaller than 1 cm(2), whereas larger lesions should be filled, either with cancellous bone or with an osteochondral graft or using autogenous chondrocyte implantation. The data available in the literature should also incite orthopaedists to consider the results of surgical management with some modesty, and conservative management should remain among the therapeutic options.

  11. Reconstruction of complex osteochondral lesions of the talus with cylindrical sponge allograft and particulate juvenile cartilage graft: provisional results with a short-term follow-up.

    PubMed

    Bleazey, Scott; Brigido, Stephen A

    2012-10-01

    Osteochondral lesions of the talus can be a challenging injury to treat for even the most experienced foot and ankle surgeon. Although the advances in imaging have made the diagnosis of chondral lesions more accurate, surgeons are still struggling to find ways to reliably treat advanced lesions with subchondral bone damage. This article looks at the use of allograft bone and particulate juvenile cartilage in patients with advanced subchondral bone damage and osteochondral lesions of the talus.

  12. [Osteochondritis dissecans of the knee].

    PubMed

    Benedict, Shaike; Oron, Amir; Beer, Yiftah; Agar, Gavriel

    2008-07-01

    Osteochondritis dissecans of the knee is diagnosed at an increasing rate among adolescents and young adults. One of the reasons is due to the increasing number of sports participants among these populations. Although many theories exist, the cause of osteochondritis dissecans is unknown. Early diagnosis is very important. While adult type osteochondritis dissecans is unstable, in most young patients it is stable, and patients with an intact articular surface have a good chance to heal with non-operative treatment and cessation of physical activity. The value of complementary treatment (bed rest, partial weight bearing, bracing aimed at reducing weight bearing of the involved knee) is unknown. Patients with open physes and stable lesions, who failed non-operative treatment, may be treated with local bone drilling, encouraging lesion healing. As the disease progresses, more aggressive measures should to be taken, whilst decreasing success ratios are expected. The healing potential of the lesion may be evaluated by magnetic resonance imaging. Most adult type osteochondritis dissecans patients, as most young patients, with unstable lesions and loose bodies within their knees, are treated with fixation of the lesions and even bone grafting. Many unstable lesions will heal after fixation, but the long-term prognosis is elusive. Chronic loose bodies are very difficult to fix, with less favorable outcomes. Excision of large lesions originating from weight bearing cartilage is not favorable and different rehabilitation measures of local cartilage damage are not encouraging. PMID:18814522

  13. Pediatric Knee Osteochondritis Dissecans Lesions.

    PubMed

    Cruz, Aristides I; Shea, Kevin G; Ganley, Theodore J

    2016-10-01

    Osteochondritis dissecans (OCD) can cause knee pain and dysfunction in children. The etiology of OCD remains unclear; theories on causes include inflammation, ischemia, ossification abnormalities, genetic factors, and repetitive microtrauma. Most OCD lesions in skeletally immature patients will heal with nonoperative treatment. The success of nonoperative treatment decreases once patients reach skeletal maturity. The goals of surgical treatment include maintenance of articular cartilage congruity, rigid fixation of unstable fragments, and repair of osteochondral defects with cells or tissues that can adequately replace lost or deficient cartilage. Unsalvageable OCD lesions can be treated with various surgical techniques. PMID:27637663

  14. Three-dimensional bioprinting of multilayered constructs containing human mesenchymal stromal cells for osteochondral tissue regeneration in the rabbit knee joint.

    PubMed

    Shim, Jin-Hyung; Jang, Ki-Mo; Hahn, Sei Kwang; Park, Ju Young; Jung, Hyuntae; Oh, Kyunghoon; Park, Kyeng Min; Yeom, Junseok; Park, Sun Hwa; Kim, Sung Won; Wang, Joon Ho; Kim, Kimoon; Cho, Dong-Woo

    2016-03-01

    The use of cell-rich hydrogels for three-dimensional (3D) cell culture has shown great potential for a variety of biomedical applications. However, the fabrication of appropriate constructs has been challenging. In this study, we describe a 3D printing process for the preparation of a multilayered 3D construct containing human mesenchymal stromal cells with a hydrogel comprised of atelocollagen and supramolecular hyaluronic acid (HA). This construct showed outstanding regenerative ability for the reconstruction of an osteochondral tissue in the knee joints of rabbits. We found that the use of a mechanically stable, host-guest chemistry-based hydrogel was essential and allowed two different types of extracellular matrix (ECM) hydrogels to be easily printed and stacked into one multilayered construct without requiring the use of potentially harmful chemical reagents or physical stimuli for post-crosslinking. To the best of our knowledge, this is the first study to validate the potential of a 3D printed multilayered construct consisting of two different ECM materials (atelocollagen and HA) for heterogeneous tissue regeneration using an in vivo animal model. We believe that this 3D printing-based platform technology can be effectively exploited for regeneration of various heterogeneous tissues as well as osteochondral tissue.

  15. Inorganic-organic hybrid scaffolds for osteochondral regeneration.

    PubMed

    Munoz-Pinto, Dany J; McMahon, Rebecca E; Kanzelberger, Melissa A; Jimenez-Vergara, Andrea C; Grunlan, Melissa A; Hahn, Mariah S

    2010-07-01

    Ligament graft failure frequently results from poor integration of the replacement tissue with associated bone. Thus, the ability to regenerate the bone-ligament osteochondral interface would be advantageous in ligament reconstruction. At the osteochondral interface, the tissue transitions from a bone-like matrix to fibrocartilage. Therefore, a scaffold which promotes a spatially regulated transition in cell behavior from osteoblast-like to chondrocyte-like would be desirable. Previous research indicates that addition of inorganic components to organic scaffolds can enhance the deposition of bone-like matrix by associated osteoblasts. We therefore reasoned that a gradient in the inorganic content of a hybrid inorganic-organic scaffold may induce an osteochondral-like transition in cell phenotype and matrix production. To test this hypothesis, hydrogels were prepared from poly(ethylene glycol) (PEG) and star poly(dimethylsiloxane) (PDMS(star)). As anticipated, both the matrix deposition and phenotype of encapsulated osteoblasts varied with scaffold inorganic content, although the directionality of this modulation was contrary to expectation. Specifically, osteoblasts appeared to transdifferentiate into chondrocyte-like cells with increasing scaffold inorganic content, as indicated by increased chondroitin sulfate and collagen type II production and by upregulation of sox9, a transcription factor associated with chondrocytic differentiation. Furthermore, the deposition of bone-like matrix (collagen type I, calcium phosphate, and osteocalcin) decreased with increasing PDMS(star) content. The resistance of the PDMS(star)-PEG scaffolds to protein adsorption and/or the changes in gel modulus/mesh structure accompanying PDMS(star) incorporation may underlie the unexpected increase in chondrocytic phenotype with increasing inorganic content. Combined, the present results indicate that PDMS(star)-PEG hybrid gels may prove promising for osteochondral regeneration. (c) 2010

  16. Vascular tissue engineering: towards the next generation vascular grafts.

    PubMed

    Naito, Yuji; Shinoka, Toshiharu; Duncan, Daniel; Hibino, Narutoshi; Solomon, Daniel; Cleary, Muriel; Rathore, Animesh; Fein, Corey; Church, Spencer; Breuer, Christopher

    2011-04-30

    The application of tissue engineering technology to cardiovascular surgery holds great promise for improving outcomes in patients with cardiovascular diseases. Currently used synthetic vascular grafts have several limitations including thrombogenicity, increased risk of infection, and lack of growth potential. We have completed the first clinical trial evaluating the feasibility of using tissue engineered vascular grafts (TEVG) created by seeding autologous bone marrow-derived mononuclear cells (BM-MNC) onto biodegradable tubular scaffolds. Despite an excellent safety profile, data from the clinical trial suggest that the primary graft related complication of the TEVG is stenosis, affecting approximately 16% of grafts within the first seven years after implantation. Continued investigation into the cellular and molecular mechanisms underlying vascular neotissue formation will improve our basic understanding and provide insights that will enable the rationale design of second generation TEVG. PMID:21421015

  17. Condensation of tissue and stem cells for fat grafting.

    PubMed

    Kuno, Shinichiro; Yoshimura, Kotaro

    2015-04-01

    Aspirated fat contains unnecessary components such as water, oil, and blood cells. For better outcomes, tissue purification and condensation are useful, especially when injection volume to the recipient site is limited. Because aspirated fat is relatively poor in adipose-derived stem/stromal cells (ASCs), ASC condensation seems important for obtaining better regeneration and retention. Reducing tissue volume by removing some adipocytes or supplementation of stromal vascular fraction or ASCs can increase the ASC/adipocyte ratio in the graft. Clinical results of ASC supplementation remain controversial, but ASC condensation seems to lead to expanding applications of fat grafting into revitalization of stem cell-depleted tissue.

  18. Decellularized Cartilage May Be a Chondroinductive Material for Osteochondral Tissue Engineering

    PubMed Central

    Sutherland, Amanda J.; Beck, Emily C.; Dennis, S. Connor; Converse, Gabriel L.; Hopkins, Richard A.; Berkland, Cory J.; Detamore, Michael S.

    2015-01-01

    Extracellular matrix (ECM)-based materials are attractive for regenerative medicine in their ability to potentially aid in stem cell recruitment, infiltration, and differentiation without added biological factors. In musculoskeletal tissue engineering, demineralized bone matrix is widely used, but recently cartilage matrix has been attracting attention as a potentially chondroinductive material. The aim of this study was thus to establish a chemical decellularization method for use with articular cartilage to quantify removal of cells and analyze the cartilage biochemical content at various stages during the decellularization process, which included a physically devitalization step. To study the cellular response to the cartilage matrix, rat bone marrow-derived mesenchymal stem cells (rBMSCs) were cultured in cell pellets containing cells only (control), chondrogenic differentiation medium (TGF-β), chemically decellularized cartilage particles (DCC), or physically devitalized cartilage particles (DVC). The chemical decellularization process removed the vast majority of DNA and about half of the glycosaminoglycans (GAG) within the matrix, but had no significant effect on the amount of hydroxyproline. Most notably, the DCC group significantly outperformed TGF-β in chondroinduction of rBMSCs, with collagen II gene expression an order of magnitude or more higher. While DVC did not exhibit a chondrogenic response to the extent that DCC did, DVC had a greater down regulation of collagen I, collagen X and Runx2. A new protocol has been introduced for cartilage devitalization and decellularization in the current study, with evidence of chondroinductivity. Such bioactivity along with providing the ‘raw material’ building blocks of regenerating cartilage may suggest a promising role for DCC in biomaterials that rely on recruiting endogenous cell recruitment and differentiation for cartilage regeneration. PMID:25965981

  19. Optical methods for diagnostic of cell-tissue grafts

    NASA Astrophysics Data System (ADS)

    Timchenko, P. E.; Timchenko, E. V.; Volova, L. T.; Boltovskaya, V. V.; Zherdeva, L. A.; Belousov, N. V.; Pershutkina, S. V.

    2015-08-01

    In this work the results of cell-tissue grafts research with a complex of optical methods - confocal fluorescent microscopy and Raman spectroscopy are presented. It was established that coefficient M scatter is related to irregularity of demineralization process. It was microscopically shown that the quantity of integrated cells into these types of transplants amounts to 20% of its surface.

  20. Strategies for osteochondral repair: Focus on scaffolds

    PubMed Central

    Seo, Seog-Jin; Mahapatra, Chinmaya; Singh, Rajendra K; Knowles, Jonathan C

    2014-01-01

    Interest in osteochondral repair has been increasing with the growing number of sports-related injuries, accident traumas, and congenital diseases and disorders. Although therapeutic interventions are entering an advanced stage, current surgical procedures are still in their infancy. Unlike other tissues, the osteochondral zone shows a high level of gradient and interfacial tissue organization between bone and cartilage, and thus has unique characteristics related to the ability to resist mechanical compression and restoration. Among the possible therapies, tissue engineering of osteochondral tissues has shown considerable promise where multiple approaches of utilizing cells, scaffolds, and signaling molecules have been pursued. This review focuses particularly on the importance of scaffold design and its role in the success of osteochondral tissue engineering. Biphasic and gradient composition with proper pore configurations are the basic design consideration for scaffolds. Surface modification is an essential technique to improve the scaffold function associated with cell regulation or delivery of signaling molecules. The use of functional scaffolds with a controllable delivery strategy of multiple signaling molecules is also considered a promising therapeutic approach. In this review, we updated the recent advances in scaffolding approaches for osteochondral tissue engineering. PMID:25343021

  1. Extracellular Calcium Modulates Chondrogenic and Osteogenic Differentiation of Human Adipose-Derived Stem Cells: A Novel Approach for Osteochondral Tissue Engineering Using a Single Stem Cell Source

    PubMed Central

    Mellor, Liliana F.; Mohiti-Asli, Mahsa; Williams, John; Kannan, Arthi; Dent, Morgan R.; Guilak, Farshid

    2015-01-01

    We have previously shown that elevating extracellular calcium from a concentration of 1.8 to 8 mM accelerates and increases human adipose-derived stem cell (hASC) osteogenic differentiation and cell-mediated calcium accretion, even in the absence of any other soluble osteogenic factors in the culture medium. However, the effects of elevated calcium on hASC chondrogenic differentiation have not been reported. The goal of this study was to determine the effects of varied calcium concentrations on chondrogenic differentiation of hASC. We hypothesized that exposure to elevated extracellular calcium (8 mM concentration) in a chondrogenic differentiation medium (CDM) would inhibit chondrogenesis of hASC when compared to basal calcium (1.8 mM concentration) controls. We further hypothesized that a full osteochondral construct could be engineered by controlling local release of calcium to induce site-specific chondrogenesis and osteogenesis using only hASC as the cell source. Human ASC was cultured as micromass pellets in CDM containing transforming growth factor-β1 and bone morphogenetic protein 6 for 28 days at extracellular calcium concentrations of either 1.8 mM (basal) or 8 mM (elevated). Our findings indicated that elevated calcium induced osteogenesis and inhibited chondrogenesis in hASC. Based on these findings, stacked polylactic acid nanofibrous scaffolds containing either 0% or 20% tricalcium phosphate (TCP) nanoparticles were electrospun and tested for site-specific chondrogenesis and osteogenesis. Histological assays confirmed that human ASC differentiated locally to generate calcified tissue in layers containing 20% TCP, and cartilage in the layers with no TCP when cultured in CDM. This is the first study to report the effects of elevated calcium on chondrogenic differentiation of hASC, and to develop osteochondral nanofibrous scaffolds using a single cell source and controlled calcium release to induce site-specific differentiation. This approach

  2. Effects of sphingosylphosphorylcholine on cryopreserved fat tissue graft survival.

    PubMed

    Bae, Yong Chan; Choi, Chi Won; Nam, Kyeong Wook; Song, Ji Sun; Lee, Jae Woo

    2016-10-01

    Autogenous microfat grafting is widely used to augment depressed deformities or for other cosmetic purposes. Since the microfat survival rate is unpredictable due to absorption and calcification, previously cryopreserved fat is widely used for secondary procedures. Sphingosylphosphorylcholine (SPC) is a lysophospholipid, which has a role in several cellular responses, and is known to stimulate DNA synthesis and proliferation. Since endothelial progenitor cells (EPCs) are known to enhance the survival rate of transplanted fat tissue, the present study assessed the effects of SPC on EPCs, in order to verify its positive effects on proliferation. Cryopreserved human fat tissues mixed with various concentrations of SPC were grafted into the nude mouse model. After grafting, the viability of each SPC mixed group was determined and compared with that of the non‑SPC group. SPC exhibited a positive effect on EPC proliferation and angiogenic potential over 3 days when used at specific concentrations. The fat grafts of the 3 µM SPC‑treated group weighed significantly more and the volume was markedly increased, as compared with the control group. A reverse transcription‑quantitative polymerase chain reaction was conducted on the total RNA extracted from SPC‑treated fat tissues, which detected increased mRNA expression levels of matrix metallopeptidase‑9 and tumor necrosis factor‑α compared with in the control group. These results indicate that specific concentrations of SPC may exert favorable effects on grafted cryopreserved human fat tissue, which may be due to the increased mRNA expression levels of genes associated with angiogenesis. PMID:27572900

  3. [Femoral head chondroblastoma and reconstruction with osteochondral allograft. Case report].

    PubMed

    Orlando-Díaz, C; Guzmán-Vargas, R; Rincon-Cardozo, D F; Mantilla-León, N; Camacho-Casas, J A

    2014-01-01

    Femoral head chondroblastoma is an infrequent tumor, accounting for approximately 1-2% of benign bone tumors. It occurs more frequently in young male patients. It's most frequent locations include the proximal humerus, proximal femur, distal femur and proximal tibia. The femoral head is the third most frequent site of this tumor. There is no specific treatment for this entity; reported treatments range from acetabular osteotomies and osteochondral grafts, to vascularized fibular grafts, all of them with good results. However, this tumor is clinically unpredictable if left untreated. We report a case managed with osteochondral graft and followed-up for three years after the surgical procedure.

  4. [Femoral head chondroblastoma and reconstruction with osteochondral allograft. Case report].

    PubMed

    Orlando-Díaz, C; Guzmán-Vargas, R; Rincon-Cardozo, D F; Mantilla-León, N; Camacho-Casas, J A

    2014-01-01

    Femoral head chondroblastoma is an infrequent tumor, accounting for approximately 1-2% of benign bone tumors. It occurs more frequently in young male patients. It's most frequent locations include the proximal humerus, proximal femur, distal femur and proximal tibia. The femoral head is the third most frequent site of this tumor. There is no specific treatment for this entity; reported treatments range from acetabular osteotomies and osteochondral grafts, to vascularized fibular grafts, all of them with good results. However, this tumor is clinically unpredictable if left untreated. We report a case managed with osteochondral graft and followed-up for three years after the surgical procedure. PMID:26016291

  5. Development of Small Diameter Nanofiber Tissue Engineered Arterial Grafts

    PubMed Central

    Tara, Shuhei; Rocco, Kevin A.; Bagi, Paul S.; Yi, Tai; Udelsman, Brooks; Zhuang, Zhen W.; Cleary, Muriel; Iwakiri, Yasuko; Breuer, Christopher K.; Shinoka, Toshiharu

    2015-01-01

    The surgical repair of heart and vascular disease often requires implanting synthetic grafts. While synthetic grafts have been successfully used for medium-to-large sized arteries, applications for small diameter arteries (<6 mm) is limited due to high rates of occlusion by thrombosis. Our objective was to develop a tissue engineered vascular graft (TEVG) for small diameter arteries. TEVGs composed of polylactic acid nanofibers with inner luminal diameter between 0.5 and 0.6 mm were surgically implanted as infra-renal aortic interposition conduits in 25 female C17SCID/bg mice. Twelve mice were given sham operations. Survival of mice with TEVG grafts was 91.6% at 12 months post-implantation (sham group: 83.3%). No instances of graft stenosis or aneurysmal dilatation were observed over 12 months post-implantation, assessed by Doppler ultrasound and microCT. Histologic analysis of explanted TEVG grafts showed presence of CD31-positive endothelial monolayer and F4/80-positive macrophages after 4, 8, and 12 months in vivo. Cells positive for α-smooth muscle actin were observed within TEVG, demonstrating presence of smooth muscle cells (SMCs). Neo-extracellular matrix consisting mostly of collagen types I and III were observed at 12 months post-implantation. PCR analysis supports histological observations. TEVG group showed significant increases in expressions of SMC marker, collagen-I and III, matrix metalloproteinases-2 and 9, and itgam (a macrophage marker), when compared to sham group. Overall, patency rates were excellent at 12 months after implantation, as structural integrity of these TEVG. Tissue analysis also demonstrated vessel remodeling by autologous cell. PMID:25830942

  6. Tissue-engineered autologous grafts for facial bone reconstruction.

    PubMed

    Bhumiratana, Sarindr; Bernhard, Jonathan C; Alfi, David M; Yeager, Keith; Eton, Ryan E; Bova, Jonathan; Shah, Forum; Gimble, Jeffrey M; Lopez, Mandi J; Eisig, Sidney B; Vunjak-Novakovic, Gordana

    2016-06-15

    Facial deformities require precise reconstruction of the appearance and function of the original tissue. The current standard of care-the use of bone harvested from another region in the body-has major limitations, including pain and comorbidities associated with surgery. We have engineered one of the most geometrically complex facial bones by using autologous stromal/stem cells, native bovine bone matrix, and a perfusion bioreactor for the growth and transport of living grafts, without bone morphogenetic proteins. The ramus-condyle unit, the most eminent load-bearing bone in the skull, was reconstructed using an image-guided personalized approach in skeletally mature Yucatán minipigs (human-scale preclinical model). We used clinically approved decellularized bovine trabecular bone as a scaffolding material and crafted it into an anatomically correct shape using image-guided micromilling to fit the defect. Autologous adipose-derived stromal/stem cells were seeded into the scaffold and cultured in perfusion for 3 weeks in a specialized bioreactor to form immature bone tissue. Six months after implantation, the engineered grafts maintained their anatomical structure, integrated with native tissues, and generated greater volume of new bone and greater vascular infiltration than either nonseeded anatomical scaffolds or untreated defects. This translational study demonstrates feasibility of facial bone reconstruction using autologous, anatomically shaped, living grafts formed in vitro, and presents a platform for personalized bone tissue engineering.

  7. Tissue-Engineered Autologous Grafts for Facial Bone Reconstruction

    PubMed Central

    Bhumiratana, Sarindr; Bernhard, Jonathan C.; Alfi, David M.; Yeager, Keith; Eton, Ryan E.; Bova, Jonathan; Shah, Forum; Gimble, Jeffrey M.; Lopez, Mandi J.; Eisig, Sidney B.; Vunjak-Novakovic, Gordana

    2016-01-01

    Facial deformities require precise reconstruction of the appearance and function of the original tissue. The current standard of care—the use of bone harvested from another region in the body—has major limitations, including pain and comorbidities associated with surgery. We have engineered one of the most geometrically complex facial bones by using autologous stromal/stem cells, without bone morphogenic proteins, using native bovine bone matrix and a perfusion bioreactor for the growth and transport of living grafts. The ramus-condyle unit (RCU), the most eminent load-bearing bone in the skull, was reconstructed using an image-guided personalized approach in skeletally mature Yucatan minipigs (human-scale preclinical model). We used clinically approved decellularized bovine trabecular bone as a scaffolding material, and crafted it into an anatomically correct shape using image-guided micromilling, to fit the defect. Autologous adipose-derived stromal/stem cells were seeded into the scaffold and cultured in perfusion for 3 weeks in a specialized bioreactor to form immature bone tissue. Six months after implantation, the engineered grafts maintained their anatomical structure, integrated with native tissues, and generated greater volume of new bone and greater vascular infiltration than either non-seeded anatomical scaffolds or untreated defects. This translational study demonstrates feasibility of facial bone reconstruction using autologous, anatomically shaped, living grafts formed in vitro, and presents a platform for personalized bone tissue engineering. PMID:27306665

  8. Reconstruction of a large osteochondral lesion of the distal tibia with an iliac crest graft and autologous matrix-induced chondrogenesis (AMIC): a case report.

    PubMed

    Miska, Matthias; Wiewiorski, Martin; Valderrabano, Victor

    2012-01-01

    Isolated osteochondral lesions (OCL) of the distal tibia are rare and lack clear treatment guidelines. With the case we present here, we suggest a novel surgical approach and report the successful use of autologous matrix-induced chondrogenesis-aided reconstruction for OCL of the distal tibia. A 29-year-old male patient complained about persisting pain of the left ankle joint and a restricted activity level 12 months after an ankle sprain. Imaging revealed edema of the subchondral bone and thinning of the cartilage above the osseous defect at the lateral distal tibia. The OCL was debrided followed by microfracturing of the underlying sclerotic bone. A cancellous bone plug was harvested from the iliac crest and impacted into the defect. A collagen matrix was then fixed on the defect. After 12 months, the patient was free of pain and returned to full activity. Conventional radiographs at 1 year showed successful osseous integration of the plug and a nearly anatomic shape of the tibial joint line. Delayed gadolinium-enhanced MRI of cartilage scans at 36 months showed an intact cartilage layer over the defect and glycosaminoglycan content, indicating hyaline-like cartilage repair. This case demonstrates autologous matrix-induced chondrogenesis-aided reconstruction of large osteochondral lesions of distal tibia to be a promising treatment method. Our aim was to describe the case of a patient with a large isolated osteochondral lesion of the distal tibia treated by a novel operative technique using cancellous bone from the iliac crest and a collagen I/III matrix.

  9. Engineered Composite Tissue as a Bioartificial Limb Graft

    PubMed Central

    Jank, Bernhard J.; Xiong, Linjie; Moser, Philipp T.; Guyette, Jacques P.; Ren, Xi; Leonard, David A.; Fernandez, Leopoldo; Ott, Harald C.

    2015-01-01

    The loss of an extremity is a disastrous injury with tremendous impact on a patient’s life. Current mechanical prostheses are technically highly sophisticated, but only partially replace physiologic function and aesthetic appearance. As a biologic alternative, approximately 70 patients have undergone allogeneic hand transplantation to date worldwide. While outcomes are favorable, risks and side effects of transplantation and long-term immunosuppression pose a significant ethical dilemma. An autologous, bio-artificial graft based on native extracellular matrix and patient derived cells could be produced on demand and would not require immunosuppression after transplantation. To create such a graft, we decellularized rat and primate forearms by detergent perfusion and yielded acellular scaffolds with preserved composite architecture. We then repopulated muscle and vasculature with cells of appropriate phenotypes, and matured the composite tissue in a perfusion bioreactor under electrical stimulation in vitro. After confirmation of composite tissue formation, we transplanted the resulting bio-composite grafts to confirm perfusion in vivo. PMID:26004237

  10. Electrospun Scaffolds for Tissue Engineering of Vascular Grafts

    PubMed Central

    Hasan, Anwarul; Memic, Adnan; Annabi, Nasim; Hossain, Monowar; Paul, Arghya; Dokmeci, Mehmet R.; Dehghani, Fariba; Khademhosseini, Ali

    2013-01-01

    There is a growing demand for off-the-shelf tissue engineered vascular grafts (TEVGs) for replacement or bypass of damaged arteries in various cardiovascular diseases. Scaffolds from the decellularized tissue skeletons to biopolymers and biodegradable synthetic polymers have been used for fabricating TEVGs. However, several issues have not yet been resolved, which include the inability to mimic the mechanical properties of native tissues, and the ability for long term patency and growth required for in vivo function. Electrospinning is a popular technique for the production of scaffolds that has the potential to address these issues. However, its application to human TEVGs has not yet been achieved. This review provides an overview of tubular scaffolds that have been prepared by electrospinning with potential for TEVG applications. PMID:23973391

  11. Bone Cysts After Osteochondral Allograft Repair of Cartilage Defects in Goats Suggest Abnormal Interaction Between Subchondral Bone and Overlying Synovial Joint Tissues

    PubMed Central

    Pallante-Kichura, Andrea L.; Cory, Esther; Bugbee, William D.; Sah, Robert L.

    2013-01-01

    The efficacy of osteochondral allografts (OCA) may be affected by osseous support of the articular cartilage, and thus affected by bone healing and remodeling in the OCA and surrounding host. Bone cysts, and their communication pathways, may be present in various locations after OCA insertion and reflect distinct pathogenic mechanisms. Previously, we analyzed the effect of OCA storage (FRESH, 4°C/14d, 4°C/28d, FROZEN) on cartilage quality in fifteen adult goats after 12 months in vivo. The objectives of this study were to further analyze OCA and contralateral non-operated (Non-Op) CONTROLS from the medial femoral condyle to (1) determine the effect of OCA storage on local subchondral (ScB) and trabecular (TB) bone structure, (2) characterize the location and structure of bone cysts and channels, and (3) assess the relationship between cartilage and bone properties. (1) Overall bone structure after OCA was altered compared to Non-Op, with OCA samples displaying bone cysts, ScB channels, and ScB roughening. ScB BV/TV in FROZEN OCA was lower than Non-Op and other OCA. TB BV/TV in FRESH, 4°C/14d, and 4°C/28d OCA did not vary compared to Non-Op, but BS/TV was lower. (2) OCA contained “basal” cysts, localized to deeper regions, some “subchondral” cysts, localized near the bone-cartilage interface, and some ScB channels. TB surrounding basal cysts exhibited higher BV/TV than Non-Op. (3) Basal cysts occurred (a) in isolation, (b) with subchondral cysts and ScB channels, (c) with ScB channels, or (d) with subchondral cysts, ScB channels, and ScB erosion. Deterioration of cartilage gross morphology was strongly associated with abnormal μCT bone structure. Evidence of cartilage-bone communication following OCA repair may favor fluid intrusion as a mechanism for subchondral cyst formation, while bone resorption at the graft-host interface without affecting overall bone and cartilage structure may favor bony contusion mechanism for basal cyst formation. These

  12. Bone cysts after osteochondral allograft repair of cartilage defects in goats suggest abnormal interaction between subchondral bone and overlying synovial joint tissues.

    PubMed

    Pallante-Kichura, Andrea L; Cory, Esther; Bugbee, William D; Sah, Robert L

    2013-11-01

    The efficacy of osteochondral allografts (OCAs) may be affected by osseous support of the articular cartilage, and thus affected by bone healing and remodeling in the OCA and surrounding host. Bone cysts, and their communication pathways, may be present in various locations after OCA insertion and reflect distinct pathogenic mechanisms. Previously, we analyzed the effect of OCA storage (FRESH, 4°C/14d, 4°C/28d, FROZEN) on cartilage quality in fifteen adult goats after 12months in vivo. The objectives of this study were to further analyze OCAs and contralateral non-operated (Non-Op) CONTROLS from the medial femoral condyle to (1) determine the effect of OCA storage on local subchondral bone (ScB) and trabecular bone (TB) structure, (2) characterize the location and structure of bone cysts and channels, and (3) assess the relationship between cartilage and bone properties. (1) Overall bone structure after OCAs was altered compared to Non-Op, with OCA samples displaying bone cysts, ScB channels, and ScB roughening. ScB BV/TV in FROZEN OCAs was lower than Non-Op and other OCAs. TB BV/TV in FRESH, 4°C/14d, and 4°C/28d OCAs did not vary compared to Non-Op, but BS/TV was lower. (2) OCAs contained "basal" cysts, localized to deeper regions, some "subchondral" cysts, localized near the bone-cartilage interface, and some ScB channels. TB surrounding basal cysts exhibited higher BV/TV than Non-Op. (3) Basal cysts occurred (a) in isolation, (b) with subchondral cysts and ScB channels, (c) with ScB channels, or (d) with subchondral cysts, ScB channels, and ScB erosion. Deterioration of cartilage gross morphology was strongly associated with abnormal μCT bone structure. Evidence of cartilage-bone communication following OCA repair may favor fluid intrusion as a mechanism for subchondral cyst formation, while bone resorption at the graft-host interface without affecting overall bone and cartilage structure may favor bony contusion mechanism for basal cyst formation. These

  13. Heparan Sulfate Proteoglycan Metabolism and the Fate of Grafted Tissues

    PubMed Central

    Wrenshall, Lucile E.; Johnson, Geoffrey B.; Cascalho, Marilia

    2016-01-01

    Tissue and organ transplants between genetically distinct individuals are always or nearly always rejected. The universality and speed of transplant rejection distinguishes this immune response from all others. Although this distinction is incompletely understood, some efforts to shed light on transplant rejection have revealed broader insights, including a relationship between activation of complement in grafted tissues, the metabolism of heparan sulfate proteoglycan and the nature of immune and inflammatory responses that ensue. Complement activation on cell surfaces, especially on endothelial cell surfaces, causes the shedding heparan sulfate, an acidic saccharide, from the cell surface and neighboring extracellular matrix. Solubilized in this way, heparan sulfate can activate leukocytes via toll like receptor-4, triggering inflammatory responses and activating dendritic cells, which migrate to regional lymphoid organs where they spark and to some extent govern cellular immune responses. In this way local ischemia, tissue injury and infection, exert systemic impact on immunity. Whether or in what circumstances this series of events explains the distinct characteristics of the immune response to transplants is still unclear but the events offer insight into the inception of immunity under the sub-optimal conditions accompanying infection and mechanisms by which infection and tissue injury engender systemic inflammation. PMID:26306447

  14. Donor-site giant cell reaction following backfill with synthetic bone material during osteochondral plug transfer.

    PubMed

    Fowler, Donald E; Hart, Joseph M; Hart, Jennifer A; Miller, Mark D

    2009-10-01

    Osteochondral defects are common in younger, active patients. Multiple strategies have been used to treat these lesions, including microfracture and osteochondral plug transfer. We describe a patient experiencing chronic knee pain and a full-thickness cartilage defect on the lateral femoral condyle. After failing conservative management and microfracture surgery, the patient underwent osteochondral autograft plug transfer, with backfilling of the donor sites using synthetic bone graft substitute. Initial recovery was uncomplicated until the patient experienced pain following a twist of the knee. Magnetic resonance imaging for the subsequent knee injury revealed poor healing at the donor sites. The donor sites were debrided, and specimens revealed a foreign body giant cell reaction. Donor-site morbidity is of primary concern during osteochondral plug transfer; however, insufficient data exist to support the use of synthetic bone graft material. Our results indicate that off-label use of synthetic bone graft substitute during a primary procedure requires further investigation.

  15. Dermal grafts to bony defects in irradiated and nonirradiated tissues

    SciTech Connect

    Lambert, P.M.; Patel, M.; Gutman, E.; Campana, H.A.

    1984-10-01

    Coverage of intraoral ablative defects presents many different problems. Free dermal grafts have been used to cover exposed mandibular bone in dogs. Grafts were placed in animals both before and after irradiation. Grafts were uniformly successful in animals not previously irradiated but failed when placed after irradiation.

  16. Infiltrating cells from host brain restore the microglial population in grafted cortical tissue.

    PubMed

    Wang, Cong; Tao, Sijue; Fang, Yukun; Guo, Jing; Zhu, Lirui; Zhang, Shengxiang

    2016-01-01

    Transplantation of embryonic cortical tissue is considered as a promising therapy for brain injury. Grafted neurons can reestablish neuronal network and improve cortical function of the host brain. Microglia is a key player in regulating neuronal survival and plasticity, but its activation and dynamics in grafted cortical tissue remain unknown. Using two-photon intravital imaging and parabiotic model, here we investigated the proliferation and source of microglia in the donor region by transplanting embryonic cortical tissue into adult cortex. Live imaging showed that the endogenous microglia of the grafted tissue were rapidly lost after transplantation. Instead, host-derived microglia infiltrated and colonized the graft. Parabiotic model suggested that the main source of infiltrating cells is the parenchyma of the host brain. Colonized microglia proliferated and experienced an extensive morphological transition and eventually differentiated into resting ramified morphology. Collectively, these results demonstrated that donor tissue has little contribution to the activated microglia and host brain controls the microglial population in the graft.

  17. Repair of osteochondral defects in rabbits with ectopically produced cartilage.

    PubMed

    Emans, Pieter J; Hulsbosch, Martine; Wetzels, Gwendolyn M R; Bulstra, Sjoerd K; Kuijer, Roel

    2005-01-01

    Cartilage has poor regenerative capacity. Donor site morbidity and interference with joint homeostasis should be considered when applying the autologous chondrocyte transplantation technique. The use of ectopically produced cartilage, derived from periosteum, might be a novel method to heal cartilage defects. Ectopic cartilage was produced by dissecting a piece of periosteum from the tibia of rabbits. After 14 days the reactive tissue at the dissection site was harvested and a graft was cored out and press-fit implanted in an osteochondral defect in the medial condyle of the femur with or without addition of hyaluronan. After 3 weeks and 3 months the repair reaction was evaluated by histology. Thionine- and collagen type II-stained sections were evaluated for graft viability, ingrowth of the graft, and joint surface repair. Empty defects remained empty 3 weeks after implantation, ectopic cartilage filled the defect to the level of the surrounding cartilage. Histologically, the grafts were viable, consisting mainly of cartilage, and showed a variable pattern of ingrowth. Three months after implantation empty defects with or without hyaluronan were filled primarily with fibrocartilaginous tissue. Defects treated with ectopic cartilage contained mixtures of fibrocartilaginous and hyaline cartilage. Sometimes a tidemark was observed in the new articular cartilage and the orientation of the cells resembled that of healthy articular cartilage. Subchondral bone repair was excellent. The modified O'Driscoll scores for empty defects without and with hyaluronan were 12.7 +/- 6.4 and 15.3 +/- 3.2; for treated defects scores were better (15.4 +/- 3.9 and 18.2 +/- 2.9). In this conceptual study the use of ectopic cartilage derived from periosteum appears to be a promising novel method for joint surface repair in rabbits.

  18. Freezing adipose tissue grafts may damage their ability to integrate into the host.

    PubMed

    Grewal, Navanjun; Yacomotti, Luciana; Melkonyan, Vahe; Massey, Marga; Bradley, James P; Zuk, Patricia A

    2009-01-01

    In this study, the effect of freezing on the morphology, viability, and VEGF synthesis of human adipose tissue grafts is examined. Currently, storage of adipose grafts involves freezing in simple saline solutions. However, the effect of freezing on the morphology and function of adipose tissue remains unclear. As a result, this study attempts to determine whether freezing adipose grafts should be considered prior to soft-tissue augmentation. In this study, the freezing of adipose grafts in saline for only 24 hr resulted in morphological changes in vivo and affected their ability to synthesize VEGF. The use of a simple cryopreservation medium containing sucrose appeared to maintain VEGF synthetic levels by the grafts and improved both their morphology and retention in vivo. However, the benefits of this cryopreservation medium were directly linked to storage time as long-term storage did not result in any noticeable benefit to graft retention. Finally, as an alternative to freezing, adipose grafts were combined with human adipose-derived stem cells (ASCs) to determine if their presence could enhance in vivo graft structure. The presence of ASCs did appear to improve graft structure in vivo over the short term and was also capable of improving tissue morphology when combined with grafts frozen in PBS. In conclusion, the successful use of adipose grafts may require a closer examination of the graft's storage conditions and time. Specifically, it now appears that the practice of freezing in saline may not be advisable if graft viability, activity, and structure are to be maintained in vivo.

  19. A Novel Esthetic Approach using Connective Tissue Graft for Soft Tissue Defect Following Surgical Excision of Gingival Fibrolipoma.

    PubMed

    Balasundaram, Aruna; Parthasarathy, Harinath; Kumar, Praveenkrishna; Gajendran, Priyalochana; Appukuttan, Devapriya

    2014-11-01

    The aim of the present case report is to evaluate the adjunctive use of a connective tissue graft to overcome soft tissue defects following excision of a gingival fibrolipoma in the aesthetic region. Connective tissue graft has been well documented for treating defects of esthetic concern. However, the literature does not contain many reports on the esthetic clinical outcome following the use of connective tissue graft secondary to excision of soft tissue tumours. A 28-year-old male patient reported with a complaint of a recurrent growth in relation to his lower front tooth region. The lesion which was provisionally diagnosed as fibroma was treated with a complete surgical excision, following which a modified coronally advanced flap and connective tissue graft was adopted to overcome the soft tissue defect. The excised growth was diagnosed histologically as fibrolipoma. One year follow up showed no recurrence of the lesion and good esthetics.The adjunctive use of the connective tissue graft and modified coronally advanced flap predictably yields optimal soft tissue fill and excellent esthetics. Hence, routine use of this procedure may be recommended for surgical excision of soft tissue growths in esthetically sensitive areas.

  20. Achieving the ideal properties for vascular bypass grafts using a tissue engineered approach: a review.

    PubMed

    Sarkar, Sandip; Schmitz-Rixen, Thomas; Hamilton, George; Seifalian, Alexander M

    2007-04-01

    The multiple demands placed on small calibre cardiovascular bypass grafts have meant that a synthetic prosthesis with good long-term patency has not been developed. A tissue-engineered graft could fulfil the ideal characteristics present in an artery. However, the great disadvantage of such a conduit is the time necessary for maturation leading to unacceptable delays once the decision to intervene surgically has been made. This maturation process is essential to produce a graft which can withstand haemodynamic stress. Once implanted, the tissue-engineered graft can contract in response to immediate haemodynamic conditions and remodel in the long term. We review the latest tissue engineering approaches used to give the favourable properties of mechanical strength, arterial compliance, low thrombogenicity, long-term resistance towards biodegradation as well as technological advances which shorten the time required for production of an implantable graft.

  1. Refixation of osteochondral fractures by ultrasound-activated, resorbable pins

    PubMed Central

    Neumann, H.; Schulz, A. P.; Gille, J.; Klinger, M.; Jürgens, C.; Reimers, N.; Kienast, B.

    2013-01-01

    Objectives Osteochondral injuries, if not treated adequately, often lead to severe osteoarthritis. Possible treatment options include refixation of the fragment or replacement therapies such as Pridie drilling, microfracture or osteochondral grafts, all of which have certain disadvantages. Only refixation of the fragment can produce a smooth and resilient joint surface. The aim of this study was the evaluation of an ultrasound-activated bioresorbable pin for the refixation of osteochondral fragments under physiological conditions. Methods In 16 Merino sheep, specific osteochondral fragments of the medial femoral condyle were produced and refixed with one of conventional bioresorbable pins, titanium screws or ultrasound-activated pins. Macro- and microscopic scoring was undertaken after three months. Results The healing ratio with ultrasound-activated pins was higher than with conventional pins. No negative heat effect on cartilage has been shown. Conclusion As the material is bioresorbable, no further surgery is required to remove the implant. MRI imaging is not compromised, as it is with implanted screws. The use of bioresorbable pins using ultrasound is a promising technology for the refixation of osteochondral fractures. PMID:23610699

  2. [Soft tissues volumes changing in malar and cheek area after fat grafting].

    PubMed

    Nadtochiy, A G; Grischenko, S V; Malitskaya, O A

    2016-01-01

    To improve the predictability of facial soft tissues fat grafting results tissue thickness dynamics before and 1 year postoperatively was assessed by means of ultrasonic method in 58 patients under standardized position of the ultrasonic transducer, physical and technical scanning conditions. The study revealed direct correlation of soft tissues thickness increase after fat grafting with the initial thickness of recipient area tissues. One year after fat grafting 60-65% of additional thickness remained in the lower regions of malar-cheek area (with the greatest soft tissues thickness), and only 25-27% preserved in the upper regions with the minimal initial thickness of soft tissues. I.e. to achieve necessary correction volume in a zone with small initial soft tissues thickness it is necessary to increase the amount of fat grafting stages. As the rates of soft tissues thickness in correction area change during 3-4 months after fat grafting remaining stable after this period it is expedient to assess postoperative results and to carry out repeated fat grafting not earlier than 4 months after operation.

  3. Mechanical and morphological evaluation of osteochondral implants in dogs.

    PubMed

    Bavaresco, Vanessa P; Garrido, Luiz; Batista, Nilza A; Malmonge, Sônia M; Belangero, William D

    2008-04-01

    The mechanical behavior of osteochondral defects was evaluated in this study with the intention of developing alternative procedures. Cylindrical pins (5.00 mm in diameter and in height) made of pHEMA hydrogel covered ultra-high molecular weight polyethylene (UHMWPE) or beta-tricalcium phosphate (beta-TCP) matrix were used. Ostoechondral defects were caused in the knees of adult dogs and the evaluation was carried out after a 9-month follow-up period. The mechanical behavior of the implants was evaluated by means of an indentation creep test that showed that the UHMWPE matrix maintained its viscoelastic behavior even after follow-up time, while the beta-TCP matrix osteochondral implants presented significant alterations. It is believed that the beta-TCP osteochondral implants were unable to withstand the load applied, causing an increase of complacency when compared to the UHMWPE osteochondral implants. Based on micro and macroscopic analysis, no significant wear was observed in either of the osteochondral implants when compared to the controls. However, morphological alterations, with fragmentation indices in the patella, were observed either due to friction with the hydrogel in the first postoperative months or due to forming of a dense conjunctive tissue. This wear mechanism caused on the counterface of the implant (patella) was observed, notwithstanding the osteochondral implant studied. PMID:18370946

  4. Esthetic Root Coverage with Double Papillary Subepithelial Connective Tissue Graft: A Case Report

    PubMed Central

    Mutthineni, Ramesh Babu; Dudala, Ram Babu; Ramisetty, Arpita

    2014-01-01

    Patients today have become excessively concerned about esthetics. These esthetic concerns of patients have become an integral part of periodontal practice. Gingival recession is an esthetic problem that can be successfully treated by means of several mucogingival surgical approaches, any of which can be used, provided that the biologic conditions for accomplishing root coverage are satisfied with no loss of soft and hard tissue height interdentally. There are currently different techniques for root coverage which include pedicle grafts, free gingival grafts, connective tissue grafts, and guided tissue regeneration (GTR). This paper reports a case in which a new double papillary connective tissue graft technique has been used in the treatment of gingival recession. PMID:24649378

  5. Layer-by-layer heparinization of decellularized liver matrices to reduce thrombogenicity of tissue engineered grafts

    PubMed Central

    Bruinsma, Bote G; Kim, Yeonhee; Berendsen, Tim A; Ozer, Sinan; Yarmush, Martin L; Uygun, Basak E

    2015-01-01

    Background Tissue-engineered liver grafts may offer a viable alternative to orthotopic liver transplantation and help overcome the donor organ shortage. Decellularized liver matrices (DLM) have a preserved vasculature and sustain hepatocellular function in culture, but graft survival after transplantation remains limited due to thrombogenicity of the matrix. Aim To evaluate the effect of heparin immobilization on DLM thrombogenicity. Methods Heparin was immobilized on DLMs by means of layer-by-layer deposition. Grafts with 4 or 8 bilayers and 2 or 4 g/L of heparin were recellularized with primary rat hepatocytes and maintained in culture for 5 days. Hemocompatibility of the graft was assessed by ex vivo diluted whole-blood perfusion and heterotopic transplantation. Results Heparin was deposited throughout the matrix and the heparin content in the graft was higher with increasing number of bilayers and concentration of heparin. Recellularization and in vitro albumin and urea production were unaffected by heparinization. Resistance to blood flow during ex vivo perfusion was lower with increased heparinization and, macroscopically, no clots were visible in grafts with 8 bilayers. Following transplantation, flow through the graft was limited in all groups. Histological evidence of thrombosis was lower in heparinized DLMs, but transplantation of DLM grafts was not improved. Conclusions Layer-by-layer deposition of heparin on a DLM is an effective method of immobilizing heparin throughout the graft and does not impede recellularization or hepatocellular function in vitro. Thrombogenicity during ex vivo blood perfusion was reduced in heparinized grafts and optimal with 8 bilayers, but transplantation remained unsuccessful with this method. Relevance for patients Tissue engineered liver grafts may offer a viable solution to dramatic shortages in donor organs PMID:26478914

  6. The tolerance of skin grafts to postoperative radiation therapy in patients with soft-tissue sarcoma

    SciTech Connect

    Lawrence, W.T.; Zabell, A.; McDonald, H.D. )

    1986-03-01

    During the last ten years at the National Cancer Institute, 11 patients have received 12 courses of postoperative adjuvant radiation therapy to skin grafts used for wound closure after the resection of soft-tissue sarcomas. The intervals between grafting and the initiation of radiation ranged between 3 and 20 weeks, and 4 patients received chemotherapy at the same time as their radiation. Ten of the 12 irradiated grafts remained intact after the completion of therapy. One graft had several small persistently ulcerated areas that required no further surgical treatment, and one graft required a musculocutaneous flap for reconstruction of a persistent large ulcer. Acute radiation effects on the grafted skin sometimes developed at slightly lower doses than usually seen with normal skin, but these acute effects necessitated a break in therapy on only five occasions. Concurrent chemotherapy and a relatively short interval between grafting and the initiation of radiation seemed to contribute to more severe radiation reactions. This experience indicates that postoperative adjuvant radiation therapy can be delivered to skin grafted areas without undue fear of complications, especially if the graft is allowed to heal adequately prior to initiating therapy and if chemotherapy is not given in conjunction with radiation.

  7. Revascularization of autogenous skin grafts placed on irradiated tissue

    SciTech Connect

    Ueda, M.; Torii, S.; Kaneda, T.; Oka, T.

    1982-08-01

    Vascular changes in rat skin after irradiation were examined microangiographically. Revascularization of the skin transplanted during the chronic stage after irradiation was also studied. The results obtained through these examinations revealed higher vascular densities at the acute and the subacute stages, and low values at the chronic stages compared with those of the control. Furthermore, when the skin grafts were transplanted to the irradiated beds in the chronic stage, primary revascularization was scant, and the inhibited capillary proliferation in the recipient sites prevented new vessel penetration. This explains why grafts transplanted to previously irradiated beds fail to survive.

  8. Tissue-engineered acellular small diameter long-bypass grafts with neointima-inducing activity.

    PubMed

    Mahara, Atsushi; Somekawa, Shota; Kobayashi, Naoki; Hirano, Yoshiaki; Kimura, Yoshiharu; Fujisato, Toshiya; Yamaoka, Tetsuji

    2015-07-01

    Researchers have attempted to develop efficient antithrombogenic surfaces, and yet small-caliber artificial vascular grafts are still unavailable. Here, we demonstrate the excellent patency of tissue-engineered small-caliber long-bypass grafts measuring 20-30 cm in length and having a 2-mm inner diameter. The inner surface of an acellular ostrich carotid artery was modified with a novel heterobifunctional peptide composed of a collagen-binding region and the integrin α4β1 ligand, REDV. Six grafts were transplanted in the femoral-femoral artery crossover bypass method. Animals were observed for 20 days and received no anticoagulant medication. No thrombogenesis was observed on the luminal surface and five cases were patent. In contrast, all unmodified grafts became occluded, and severe thrombosis was observed. The vascular grafts reported here are the first successful demonstrations of short-term patency at clinically applicable sizes. PMID:25941782

  9. Tissue engineering of the small intestine by acellular collagen sponge scaffold grafting.

    PubMed

    Hori, Y; Nakamura, T; Matsumoto, K; Kurokawa, Y; Satomi, S; Shimizu, Y

    2001-01-01

    Tissue engineering of the small intestine will prove a great benefit to patients suffering from short bowel disease. However cell seeding in tissue engineering, such as fetal cell use, is accompanied by problems of ethical issues, rejection, and short supply. To overcome these problems, we carried out an experimental study on tissue engineering of the small intestine by acellular collagen sponge scaffold grafting. We resected the 5 cm long jejunum from beagle dogs and reconstructed it by acellular collagen sponge grafting with a silicon tube stent. The graft was covered with the omentum. At 1 month after operation, the silicon stent was removed endoscopically. Animals were sacrificed 1 and 4 months after operation, and were examined microscopically. Neo-intestinal regeneration was observed and the intestinal mucosa covered the luminal side of the regenerated intestine across the anastomosis. Thus, the small intestine was regenerated by tissue engineering technology using an acellular collagen sponge scaffold.

  10. Infiltrating cells from host brain restore the microglial population in grafted cortical tissue

    PubMed Central

    Wang, Cong; Tao, Sijue; Fang, Yukun; Guo, Jing; Zhu, Lirui; Zhang, Shengxiang

    2016-01-01

    Transplantation of embryonic cortical tissue is considered as a promising therapy for brain injury. Grafted neurons can reestablish neuronal network and improve cortical function of the host brain. Microglia is a key player in regulating neuronal survival and plasticity, but its activation and dynamics in grafted cortical tissue remain unknown. Using two-photon intravital imaging and parabiotic model, here we investigated the proliferation and source of microglia in the donor region by transplanting embryonic cortical tissue into adult cortex. Live imaging showed that the endogenous microglia of the grafted tissue were rapidly lost after transplantation. Instead, host-derived microglia infiltrated and colonized the graft. Parabiotic model suggested that the main source of infiltrating cells is the parenchyma of the host brain. Colonized microglia proliferated and experienced an extensive morphological transition and eventually differentiated into resting ramified morphology. Collectively, these results demonstrated that donor tissue has little contribution to the activated microglia and host brain controls the microglial population in the graft. PMID:27615195

  11. Infiltrating cells from host brain restore the microglial population in grafted cortical tissue.

    PubMed

    Wang, Cong; Tao, Sijue; Fang, Yukun; Guo, Jing; Zhu, Lirui; Zhang, Shengxiang

    2016-01-01

    Transplantation of embryonic cortical tissue is considered as a promising therapy for brain injury. Grafted neurons can reestablish neuronal network and improve cortical function of the host brain. Microglia is a key player in regulating neuronal survival and plasticity, but its activation and dynamics in grafted cortical tissue remain unknown. Using two-photon intravital imaging and parabiotic model, here we investigated the proliferation and source of microglia in the donor region by transplanting embryonic cortical tissue into adult cortex. Live imaging showed that the endogenous microglia of the grafted tissue were rapidly lost after transplantation. Instead, host-derived microglia infiltrated and colonized the graft. Parabiotic model suggested that the main source of infiltrating cells is the parenchyma of the host brain. Colonized microglia proliferated and experienced an extensive morphological transition and eventually differentiated into resting ramified morphology. Collectively, these results demonstrated that donor tissue has little contribution to the activated microglia and host brain controls the microglial population in the graft. PMID:27615195

  12. Antigen Removal for the Production of Biomechanically Functional, Xenogeneic Tissue Grafts

    PubMed Central

    Cissell, Derek D.; Hu, Jerry C.; Griffiths, Leigh G.; Athanasiou, Kyriacos A.

    2013-01-01

    Xenogeneic tissues are derived from other animal species and provide a source of material for engineering mechanically functional tissue grafts, such as heart valves, tendons, ligaments, and cartilage. Xenogeneic tissues, however, contain molecules, known as antigens, which invoke an immune reaction following implantation into a patient. Therefore, it is necessary to remove the antigens from a xenogeneic tissue to prevent immune rejection of the graft. Antigen removal can be accomplished by treating a tissue with solutions and/or physical processes that disrupt cells and solubilize, degrade, or mask antigens. However, processes used for cell and antigen removal from tissues often have deleterious effects on the extracellular matrix (ECM) of the tissue, rendering the tissue unsuitable for implantation due to poor mechanical properties. Thus, the goal of an antigen removal process should be to reduce the antigen content of a xenogeneic tissue while preserving its mechanical functionality. To expand the clinical use of antigen-removed xenogeneic tissues as biomechanically functional grafts, it is essential that researchers examine tissue antigen content, ECM composition and architecture, and mechanical properties as new antigen removal processes are developed. PMID:24268315

  13. Multiple osteochondral autograft transfer to the proximal interphalangeal joint: case report.

    PubMed

    Ozyurekoglu, Tuna

    2010-06-01

    A 17-year-old boy who played baseball presented with swelling, pain, and crepitation in the right ring finger proximal interphalangeal joint after a remote trauma. Multiple osteochondral defects were identified on opposing articular surfaces. Cylindrical osteochondral grafts of 2.0, 2.5, and 5.0 mm were applied to the defects and congruency was restored. We confirmed vascularity of the grafts by magnetic resonance. The boy returned to full sports activities. No signs of arthritis were seen at 4-year follow-up radiographs.

  14. Bone Grafts

    MedlinePlus

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, ... fractures or cancers. Once your body accepts the bone graft, it provides a framework for growth of new, ...

  15. The Biological Response following Autogenous Bone Grafting for Large-Volume Defects of the Knee

    PubMed Central

    DeLano, Mark C.; Spector, Myron; Jeng, Lily; Pittsley, Andrew; Gottschalk, Alexander

    2012-01-01

    Objective: This report focuses on the biological events occurring at various intervals following autogenous bone grafting of large-volume defects of the knee joint’s femoral condyle secondary to osteochondritis dissecans (OCD) or osteonecrosis (ON). It was hypothesized that the autogenous bone graft would integrate and the portion exposed to the articular surface would form fibrocartilage, which would endure for years. Methods: Between September 29, 1987 and August 8, 1994, there were 51 patients treated with autogenous bone grafting for large-volume osteochondral defects. Twenty-five of the 51 patients were available for long-term follow-up up to 21 years. Patient follow-up was accomplished by clinical opportunity and intentional research. Videotapes were available on all index surgeries for review and comparison. All had preoperative and postoperative plain film radiographs. Long-term follow-up included MRI up to 21 years. Second-look arthroscopy and biopsy were obtained on 14 patients between 8 weeks and 20 years. Results: Radiological assessment showed the autogenous bone grafts integrated with the host bone. The grafts retained the physical geometry of the original placement. MRI showed soft tissue covering the grafts in all cases at long-term follow-up. Interval biopsy showed the surface covered with fibrous tissue at 8 weeks and subsequently converted to fibrocartilage with hyaline cartilage at 20 years. Conclusion: Autogenous bone grafting provides a matrix for large osteochondral defects that integrates with the host bone and results in a surface repair of fibrocartilage and hyaline cartilage that can endure for up to 20 years. PMID:26069622

  16. Grinding and polishing instead of sectioning for the tissue samples with a graft: Implications for light and electron microscopy.

    PubMed

    Mukhamadiyarov, Rinat A; Sevostyanova, Victoria V; Shishkova, Daria K; Nokhrin, Andrey V; Sidorova, Olga D; Kutikhin, Anton G

    2016-06-01

    A broad use of the graft replacement requires a detailed investigation of the host-graft interaction, including both histological examination and electron microscopy. A high quality sectioning of the host tissue with a graft seems to be complicated; in addition, it is difficult to examine the same tissue area by both of the mentioned microscopy techniques. To solve these problems, we developed a new technique of epoxy resin embedding with the further grinding, polishing, and staining. Graft-containing tissues prepared by grinding and polishing preserved their structure; however, sectioning frequently required the explantation of the graft and led to tissue disintegration. Moreover, stained samples prepared by grinding and polishing may then be assessed by both light microscopy and backscattered scanning electron microscopy. Therefore, grinding and polishing outperform sectioning when applied to the tissues with a graft. PMID:27023831

  17. Prosthetic soft tissue management following two periimplant graft failures: a clinical report.

    PubMed

    Issarayangkul, Charinthorn; Schoenbaum, Todd R; McLaren, Edward A

    2013-09-01

    A 53-year-old man experienced 2 soft tissue graft failures resulting in sizable hard and soft tissue defects in the esthetic zone following implant placement. A third connective tissue graft surgery was successful in repairing the defect and significantly improving soft tissue quality. A screw-retained, interim implant prosthesis was instrumental in gradually shaping the soft tissue over the course of the 3 surgeries. The interim prosthesis was modified numerous times to achieve a balance of esthetics, surgical protection, and gingival contours. The initial form of the prosthesis was designed to protect the surgical site and allow space for postsurgical edema. In its final form, the tissue side of the interim prosthesis pontic was designed to mimic the cross-sectional profile of a natural central incisor root but modified to deliver gentle pressure until maximum papilla height was achieved. The definitive restoration was fabricated to mimic the final design of the interim restoration and gingival architecture.

  18. How I Manage Osteochondritis Dissecans.

    ERIC Educational Resources Information Center

    DiStefano, Vincent J.

    1986-01-01

    Osteochondritis dissecans, a lesion found most often on the femur at the knee joint, occurs most frequently in active adolescents. This article describes treatment for preadolescents, adolescents, and adults. Osteochondritus dissecans of the patella is also presented. (MT)

  19. Osteochondral Lesions of Major Joints

    PubMed Central

    Durur-Subasi, Irmak; Durur-Karakaya, Afak; Yildirim, Omer Selim

    2015-01-01

    This paper provides information about osteochondral lesions (OCL) and example cases of OCL occurring in major joints, some of which are rarely seen. This simple tutorial is presented in question and answer format. PMID:26180500

  20. Aged adrenal medullary tissue survives intraocular grafting, forms nerve fibers and responds to nerve growth factor.

    PubMed

    Strömberg, I; Ebendal, T

    1989-06-01

    Adrenal medullary tissue from aged (24 months old) and young adult (2 months old) rats was grafted to the anterior chamber of the eye of previously sympathectomized animals. Nerve growth factor (NGF) was administered by weekly bilateral intraocular injections. Five weeks postgrafting, irides were prepared as whole mounts and processed for Falck-Hillarp histochemistry for visualization of catecholamines. NGF appeared to partially prevent the reduction in volume that both old and young grafts underwent. In the presence of NGF, an extensive, dense fiber network, closely resembling the normal adrenergic innervation, was formed in the host irides by grafts from aged donors. The area of outgrowth from aged transplants without NGF treatment was as large as with NGF treatment but less dense. The reinnervation of irides by NGF-treated young adult grafts occupied a similar area as that seen with aged grafts, but the pattern of innervation was irregular, particularly close to the transplants. Transplants from young adult donors without NGF treatment generated a sparse, limited network of nerves in the irides. All grafts were tyrosine hydroxylase-, adrenaline-, and dopamine-beta-hydroxylase-immunoreactive in about the same proportion of cells, but the grafts from the young donors were smaller in size. We concluded that the ability of chromaffin cells to transform toward a neuronal phenotype, produce nerve fibers, and respond to exogenous NGF is maintained in aged adrenals. PMID:2754763

  1. Osteochondral grafting of knee joint using mosaicplasty.

    PubMed

    Wajid, Muhammad Abdul; Shah, Muhammad Idrees; Mohsin-e-Azam; Ahmad, Tashfeen

    2011-03-01

    Focal cartilage defects of articular surface-traumatic and degenerative are difficult to treat, thus a variety of surgical techniques have been developed and reported for treatment of such defects. Procedures such as Priddies perforations, microfracture, abrasion chondroplasty have shown long-term results which are often less than adequate. One of the reasons is that all these techniques lead to the formation of fibrocartilage which has inferior mechanical properties as compared to the native hyaline cartilage. Mosaicplasty is a procedure which aims at replacing the lost articular cartilage with hyaline cartilage including underlying bone support, thus providing adequate stability to the cartilage and better cartilage/bone integration. A young man underwent this procedure for recalcitrant knee pain at our institution. At 2 years follow-up, his knee pain has significantly improved. We hereby present medium term results (2 years) of this first case report in local literature.

  2. Osteochondral Autograft from the Ipsilateral Femoral Head by Surgical Dislocation for Treatment of Femoral Head Fracture Dislocation: A Case Report.

    PubMed

    Won, Yougun; Lee, Gi Soo; Kim, Sang Bum; Kim, Sun Joong; Yang, Kyu Hyun

    2016-11-01

    As anatomical reduction of the articular surface of femoral head fractures and restoration of damaged cartilage are essential for good long-term results, many treatment options have been suggested, including fixation of the fracture using various surgical exposures and implants, as well as arthroscopic irrigation and debridement, bone marrow stimulating techniques, osteochondral allograft, autograft, and autogenous chondrocyte implantation. We report a case of osteochondral autograft harvested from its own femoral articular surface through surgical hip dislocation. The osteochondral graft was harvested from the inferior non-weight-bearing articular surface and grafted to the osteochondral defect. One year later, the clinical and radiological results were good, without the collapse of the femoral head or arthritic change. This procedure introduced in our case is considered convenient and able to lessen surgical time without morbidity of the donor site associated with the harvest. PMID:27593886

  3. Osteochondral Autograft from the Ipsilateral Femoral Head by Surgical Dislocation for Treatment of Femoral Head Fracture Dislocation: A Case Report

    PubMed Central

    Won, Yougun; Kim, Sang Bum; Kim, Sun Joong; Yang, Kyu-Hyun

    2016-01-01

    As anatomical reduction of the articular surface of femoral head fractures and restoration of damaged cartilage are essential for good long-term results, many treatment options have been suggested, including fixation of the fracture using various surgical exposures and implants, as well as arthroscopic irrigation and debridement, bone marrow stimulating techniques, osteochondral allograft, autograft, and autogenous chondrocyte implantation. We report a case of osteochondral autograft harvested from its own femoral articular surface through surgical hip dislocation. The osteochondral graft was harvested from the inferior non-weight-bearing articular surface and grafted to the osteochondral defect. One year later, the clinical and radiological results were good, without the collapse of the femoral head or arthritic change. This procedure introduced in our case is considered convenient and able to lessen surgical time without morbidity of the donor site associated with the harvest. PMID:27593886

  4. Ectopic porcine spermatogenesis in murine subcutis: tissue grafting versus cell-injection methods

    PubMed Central

    Watanabe, Takeshi; Hayashi, Hirofumi; Kita, Kaoru; Kubota, Yoshinobu; Ogawa, Takehiko

    2009-01-01

    Fragments of testis tissue from immature animals grow and develop spermatogenesis when grafted onto subcutaneous areas of immunodeficient mice. The same results are obtained when dissociated cells from immature testes of rodents are injected into the subcutis of nude mice. Those cells reconstitute seminiferous tubules and facilitate spermatogenesis. We compared these two methods, tissue grafting and cell-injection methods, in terms of the efficiency of spermatogenesis in the backs of three strains of immunodeficient mice, using neonatal porcine testicular tissues and cells as donor material. Nude, severe combined immunodeficient (SCID) and NOD/Shi-SCID, IL-2Rγcnull (NOG) mice were used as recipients. At 10 months after surgery, the transplants were examined histologically. Both grafting and cell-injection methods resulted in porcine spermatogenesis on the backs of recipient mice; the percentage of spermatids present in the transplants was 67% and 22%, respectively. Using the grafting method, all three strains of mice supported the same extent of spermatogenesis. As for the cell-injection method, although SCID mice were the best host for supporting reconstitution and spermatogenesis, any difference from the other strains was not significant. As NOG mice did not show any better results, the severity of immunodeficiency seemed to be irrelevant for supporting xeno-ectopic spermatogenesis. Our results confirmed that tubular reconstitution is applicable to porcine testicular cells. This method as well as the grafting method would be useful for studying spermatogenesis in different kinds of animals. PMID:19137001

  5. Treatment of osteochondral injuries with platelet gel

    PubMed Central

    Danieli, Marcus Vinicius; da Rosa Pereira, Hamilton; de Sá Carneiro, Carlos Augusto; Felisbino, Sérgio Luiz; Deffune, Elenice

    2014-01-01

    OBJECTIVES: Treatments for injured articular cartilage have not advanced to the point that efficient regeneration is possible. However, there has been an increase in the use of platelet-rich plasma for the treatment of several orthopedic disorders, including chondral injuries. Our hypothesis is that the treatment of chondral injuries with platelet gel results in higher-quality repair tissue after 180 days compared with chondral injuries not treated with gel. METHODS: A controlled experimental laboratory study was performed on 30 male rabbits to evaluate osteochondral injury repair after treatment with or without platelet gel. Osteochondral injuries were surgically induced in both knees of each rabbit at the medial femoral condyle. The left knee injury was filled with the platelet gel, and the right knee was not treated. Microscopic analysis of both knee samples was performed after 180 days using a histological grading scale. RESULTS: The only histological evaluation criterion that was not significantly different between treatments was metachromasia. The group that was treated with platelet gel exhibited superior results in all other criteria (cell morphology, surface regularity, chondral thickness and repair tissue integration) and in the total score. CONCLUSION: The repair tissue was histologically superior after 180 days in the study group treated with platelet gel compared with the group of untreated injuries. PMID:25518022

  6. Donor-site morbidity after osteochondral autograft transfer procedures.

    PubMed

    LaPrade, Robert F; Botker, Jesse C

    2004-09-01

    We report on 2 patients who had donor-site morbidity after an autogenous osteochondral grafting was performed. Both patients had fibrocartilage hypertrophy at the donor sites that contributed to knee pain and occasional locking; the second patient also had a lack of fibrocartilaginous regrowth with symptomatic residual osteocartilaginous defects. Additional arthroscopic surgery was required in both cases to trim the fibrocartilage. In addition, for the second case, a fresh osteoarticular allograft was used to transfer osteocartilaginous plugs back into the original knee donor sites due to continued knee pain. When performing an osteochondral autograft transfer, the benefits provided at the recipient site must be weighed against the possible donor-site morbidity that may result.

  7. Effect of different cryoprotectant agents on spermatogenesis efficiency in cryopreserved and grafted neonatal mouse testicular tissue.

    PubMed

    Yildiz, Cengiz; Mullen, Brendan; Jarvi, Keith; McKerlie, Colin; Lo, Kirk C

    2013-08-01

    Restoration of male fertility associated with use of the cryopreserved testicular tissue would be a significant advance in human and animal assisted reproductive technology. The purpose of this study was to test the effects of four different cryoprotectant agents (CPA) on spermatogenesis and steroidogenesis in cryopreserved and allotransplanted neonatal mouse testicular tissue. Hank's balanced salt solution (HBSS) with 5% fetal bovine serum including either 0.7 M dimethyl sulfoxide (DMSO), 0.7 M propylene glycol (PrOH), 0.7 M ethylene glycol (EG), or glycerol was used as the cryoprotectant solution. Donor testes were collected and dissected from neonatal pups of CD-1 mice (one day old). Freezing and seeding of the testicular whole tissues was performed using an automated controlled-rate freezer. Four fresh (non-frozen) or frozen-thawed pieces of testes were subcutaneously grafted onto the hind flank of each castrated male NCr nude recipient mouse and harvested after 3 months. Fresh neonatal testes grafts recovered from transplant sites had the most advanced rate of spermatogenesis with elongated spermatid and spermatozoa in 46.6% of seminiferous tubules and had higher levels of serum testosterone compared to all other frozen-thawed-graft groups (p<0.05). Fresh grafts and frozen-thawed grafts in the DMSO group had the highest rate of tissue survival compared to PrOH, EG, and glycerol after harvesting (p>0.05). The most effective CPA for the freezing and thawing of neonatal mouse testes was DMSO in comparison with EG (p<0.05) in both pre-grafted and post-grafted tissues based on histopathological evaluation. Likewise, the highest level of serum testosterone was obtained from the DMSO CPA group compared to all other cryoprotectants evaluated (p<0.05). The typical damage observed in the frozen-thawed grafts included disruption of the interstitial stroma, intercellular connection ruptures, and detachment of spermatogonia from the basement membrane. These findings

  8. The use of embryonic cells in the treatment of osteochondral defects of the knee: an ovine in vivo study

    PubMed Central

    MANUNTA, ANDREA FABIO; ZEDDE, PIETRO; PILICCHI, SUSANNA; ROCCA, STEFANO; POOL, ROY R.; DATTENA, MARIA; MASALA, GEROLAMO; MARA, LAURA; CASU, SARA; SANNA, DANIELA; MANUNTA, MARIA LUCIA; PASSINO, ERALDO SANNA

    2016-01-01

    Purpose the aim of this study was to determine whether local delivery of embryonic stem-like (ESL) cells into osteochondral defects in the femoral condyles of sheep would enhance regeneration of hyaline articular cartilage. Methods male ESL cells embedded in fibrin glue were engrafted into osteochondral defects in the medial condyles (ESL-M) of the left femur in 22 ewes. An identical defect was created in the medial condyle of the contralateral stifle joint and left untreated as a control (empty defect, ED). The ewes were divided into 5 groups. Four sheep each were euthanized at 1, 2, 6, and 12 months from surgery, and 6 ewes were euthanized 24 months post-implantation. To study the effect of varying loads on the long-term regeneration process, an identical defect was also created and ESL cell engraftment performed in the lateral condyle (ESL-L) of the left stifle joint of the animals in the 12- and 24-month groups. The evaluation of regenerated tissue was performed by biomechanical, macroscopic, histological, immunohistochemical (collagen type II) and fluorescent in situ hybridization (FISH) assays. Results no significant differences were found between treated and control sites in the biomechanical assays at any time point. ESL cell grafts showed significantly greater macroscopic evidence of regeneration as compared to controls at 24 months after surgery; significantly better histological evidence of repair in ESL-M samples versus controls was found throughout the considered period. At 24 months from surgery there was significantly improved integration of graft edges with the host tissue in the ESL-M as compared to the ESL-L samples, demonstrating that load bearing positively affects the long-term regeneration process. Conclusions ESL cells enhanced the regeneration of hyaline cartilage. FISH confirmed that the regenerative tissue originated from ESL cells. Clinical Relevance ESL cells are able to self-renew for prolonged periods without differentiation and, most

  9. The use of embryonic cells in the treatment of osteochondral defects of the knee: an ovine in vivo study

    PubMed Central

    MANUNTA, ANDREA FABIO; ZEDDE, PIETRO; PILICCHI, SUSANNA; ROCCA, STEFANO; POOL, ROY R.; DATTENA, MARIA; MASALA, GEROLAMO; MARA, LAURA; CASU, SARA; SANNA, DANIELA; MANUNTA, MARIA LUCIA; PASSINO, ERALDO SANNA

    2016-01-01

    Purpose the aim of this study was to determine whether local delivery of embryonic stem-like (ESL) cells into osteochondral defects in the femoral condyles of sheep would enhance regeneration of hyaline articular cartilage. Methods male ESL cells embedded in fibrin glue were engrafted into osteochondral defects in the medial condyles (ESL-M) of the left femur in 22 ewes. An identical defect was created in the medial condyle of the contralateral stifle joint and left untreated as a control (empty defect, ED). The ewes were divided into 5 groups. Four sheep each were euthanized at 1, 2, 6, and 12 months from surgery, and 6 ewes were euthanized 24 months post-implantation. To study the effect of varying loads on the long-term regeneration process, an identical defect was also created and ESL cell engraftment performed in the lateral condyle (ESL-L) of the left stifle joint of the animals in the 12- and 24-month groups. The evaluation of regenerated tissue was performed by biomechanical, macroscopic, histological, immunohistochemical (collagen type II) and fluorescent in situ hybridization (FISH) assays. Results no significant differences were found between treated and control sites in the biomechanical assays at any time point. ESL cell grafts showed significantly greater macroscopic evidence of regeneration as compared to controls at 24 months after surgery; significantly better histological evidence of repair in ESL-M samples versus controls was found throughout the considered period. At 24 months from surgery there was significantly improved integration of graft edges with the host tissue in the ESL-M as compared to the ESL-L samples, demonstrating that load bearing positively affects the long-term regeneration process. Conclusions ESL cells enhanced the regeneration of hyaline cartilage. FISH confirmed that the regenerative tissue originated from ESL cells. Clinical Relevance ESL cells are able to self-renew for prolonged periods without differentiation and, most

  10. Development of a Sterile Amniotic Membrane Tissue Graft Using Supercritical Carbon Dioxide.

    PubMed

    Wehmeyer, Jennifer L; Natesan, Shanmugasundaram; Christy, Robert J

    2015-07-01

    Numerous techniques have been reported for preparing and sterilizing amniotic membrane (AM) for use in clinical applications. However, these preparations either do not produce completely sterile tissue or are detrimental to molecules unique to the tissue matrix, thus compromising beneficial wound-healing properties of the AM graft. The objective of this work was to produce a sterile human AM tissue graft using a novel preparation technique involving supercritical carbon dioxide (SCCO2). AM tissue was subjected to various sterilization treatment groups that optimized the duration of exposure to SCCO2 and the amount of peracetic acid (PAA) required to achieve a sterility assurance level of 10(-6) log reduction in bacterial load. Effects of sterilization treatment on the histological, biophysical, and biochemical properties of the sterile AM were evaluated and compared with those of native AM tissue. Exposure of the AM tissue to combined SCCO2 and PAA sterilization treatment did not significantly alter tissue architecture, the amounts of pertinent extracellular matrix proteins (type IV collagen, glycosaminoglycans, elastin) present in the tissue, or the biophysical properties of the tissue. AMs treated with SCCO2 were also found to be excellent substrates for adipose-derived stem cell (ASC) attachment and proliferation in vitro. Human ASCs, attached to all treatment groups after 24 h of culture and continued to proliferate over the next few days. The current study's results indicate that SCCO2 can be used to sterilize AM tissue grafts while simultaneously preserving their biological attributes. The preservation of these features make AM appealing for use in numerous clinical and tissue engineering applications.

  11. Development of a Sterile Amniotic Membrane Tissue Graft Using Supercritical Carbon Dioxide.

    PubMed

    Wehmeyer, Jennifer L; Natesan, Shanmugasundaram; Christy, Robert J

    2015-07-01

    Numerous techniques have been reported for preparing and sterilizing amniotic membrane (AM) for use in clinical applications. However, these preparations either do not produce completely sterile tissue or are detrimental to molecules unique to the tissue matrix, thus compromising beneficial wound-healing properties of the AM graft. The objective of this work was to produce a sterile human AM tissue graft using a novel preparation technique involving supercritical carbon dioxide (SCCO2). AM tissue was subjected to various sterilization treatment groups that optimized the duration of exposure to SCCO2 and the amount of peracetic acid (PAA) required to achieve a sterility assurance level of 10(-6) log reduction in bacterial load. Effects of sterilization treatment on the histological, biophysical, and biochemical properties of the sterile AM were evaluated and compared with those of native AM tissue. Exposure of the AM tissue to combined SCCO2 and PAA sterilization treatment did not significantly alter tissue architecture, the amounts of pertinent extracellular matrix proteins (type IV collagen, glycosaminoglycans, elastin) present in the tissue, or the biophysical properties of the tissue. AMs treated with SCCO2 were also found to be excellent substrates for adipose-derived stem cell (ASC) attachment and proliferation in vitro. Human ASCs, attached to all treatment groups after 24 h of culture and continued to proliferate over the next few days. The current study's results indicate that SCCO2 can be used to sterilize AM tissue grafts while simultaneously preserving their biological attributes. The preservation of these features make AM appealing for use in numerous clinical and tissue engineering applications. PMID:25471248

  12. Design and optimization of a tissue-engineered bone graft substitute

    NASA Astrophysics Data System (ADS)

    Shimko, Daniel Andrew

    2004-12-01

    In 2000, 3.1 million surgical procedures on the musculoskeletal system were reported in the United States. For many of these cases, bone grafting was essential for successful fracture stabilization. Current techniques use intact bone obtained either from the patient (autograft) or a cadaver (allograft) to repair large defects, however, neither source is optimal. Allografts suffer integration problems, and for autografts, the tissue supply is limited. Because of these shortcomings, and the high demand for graft tissues, alternatives are being explored. To successfully engineer a bone graft replacement, one must employ a three pronged research approach, addressing (1) the cells that will inhabit the new tissue, (2) the culture environment that these cells will be exposed to, and (3) the scaffold in which these cells will reside. The work herein examines each of these three aspects in great detail. Both adult and embryonic stem cells (ESCs) were considered for the tissue-engineered bone graft. Both exhibited desirable qualities, however, neither were optimal in all categories examined. In the end, the possibility of teratoma formation and ethical issues surrounding ESCs, made the use of adult marrow-derived stem cells in the remaining experiments obligatory. In subsequent experiments, the adult stem cells' ability to form bone was optimized. Basic fibroblast growth factor, fetal bovine serum, and extracellular calcium supplementation studies were all performed. Ultimately, adult stem cells cultured in alpha-MEM supplemented with 10% fetal bovine serum, 10mM beta-glycerophosphate, 10nM dexamethasone, 50mug/ml ascorbic acid, 1%(v/v) antibiotic/antimycotic, and 10.4mM CaCl2 performed the best, producing nearly four times more mineral than any other medium formulation. Several scaffolds were then investigated including those fabricated from poly(alpha-hydroxy esters), tantalum, and poly-methylmethacrylate. In the final study, the most appealing cell type, medium

  13. [Viability of autologous fat grafts harvested with the Coleman technique and the tissu trans system (shippert method): a comparative study].

    PubMed

    Herold, C; Pflaum, M; Utz, P; Wilhelmi, M; Rennekampff, H-O; Vogt, P M

    2011-12-01

    Various methods for harvesting and refining autologous fat grafts have been described. One of the standard procedures, the Coleman technique, is based on manual aspiration to reduce the negative presssure and the centrifugation of the grafts. The Shippert technique uses automatic liposuction with reduced negative pressure and abstains from centifugation in order not to reduce viability of the graft by exposing it to centrifugal forces. This study intends to compare the viability of fat grafts processed with the above-mentioned methods.Fat grafts were obtained in 9 patients by using both the Tissu Trans system (Shippert technique) and the Coleman technique. To evaluate the impact of centrifugation forces, the grafts harvested with the Coleman technique were treated with standard adjustment of the centrifuge and also with doubled g-force. Viability of fat grafts was analysed with the WST-8 test and with annexin V/PI assay FACS analysis.The viability of fat grafts processed by the Coleman technique was significantly higher compared to the Shippert technique on applying the WST-8 test. Applying the annexin V/PI analysis, the viability of fat grafts was almost equal with both techniques. Whereas the fat grafts processed with the Tissu Trans system are injected without condensation, the grafts refined with the Coleman technique were concentrated 3 times by centrifugation compared to the primary liposuctioned graft volumes.The Coleman technique allows the preparation of a fat graft containing more viable cells than the Shippert technique. This is in part due to the condensation of the graft by centrifugation using the Coleman technique. The factor of condensation of the grafts harvested and refined with the Coleman technique exceeds the factor of increased fat graft viability in comparison to the Shippert technique. The Tissu Trans system is more than twice as fast and easier to use with a preferential use for large volume grafts like in breast augmentation, whereas the

  14. Combination of negative pressure wound therapy with open bone grafting for bone and soft tissue defects.

    PubMed

    Deng, Kai; Yu, Ai-Xi; Xia, Cheng-Yan; Li, Zong-Huan; Wang, Wei-Yang

    2013-08-01

    The aim of this study was to investigate the efficiency of negative pressure wound therapy (NPWT) combined with open bone graft (OBG; NPWT-OBG) for the treatment of bone and soft tissue defects with polluted wounds in an animal model. All rabbits with bone and soft tissue defects and polluted wounds were randomly divided into two groups, the experimental group (NPWT with bone graft) and the control group (OBG). The efficacy of the treatment was assessed by the wound conditions and healing time. Bacterial bioburdens and bony calluses were evaluated by bacteria counting and X-rays, respectively. Furthermore, granulation tissue samples from the wounds on days 0, 3, 7 and 14 of healing were evaluated for blood vessels and vascular endothelial growth factor (VEGF) levels. Wounds in the experimental group tended to have a shorter healing time, healthier wound conditions, lower bacterial bioburden, improvement of the bony calluses and an increased blood supply compared with those in the control group. With NPWT, wound infection was effectively controlled. For wounds with osseous and soft tissue defects, NPWT combined with bone grafting was demonstrated to be more effective than an OBG.

  15. Fragmented Adipose Tissue Graft for Bone Healing: Histological and Histometric Study in Rabbits’ Calvaria

    PubMed Central

    Oliveira, Lidiane C.; Giovanini, Allan F.; Abuabara, Allan; Klug, Luiz G.; Gonzaga, Carla C.; Zielak, João C.; Urban, Cícero A.

    2013-01-01

    Objective The adipose tissue represents an important reservoir of stem cells. There are few studies in the literature with which to histologically evaluate whether or not the adipose tissue graft is really a safe option to achieve bone repair. This study histologically analyzed the effect of fragmented autogenous adipose tissue grafts on bone healing in surgically created, critical-size defects (CSD) in a rabbit’s calvaria. Study design Forty-two New Zealand rabbits were used in this study. CSD that were 15 mm in diameter were created in the calvarium of each animal. The defects were randomly divided into two groups: in Group C (control), the defect was filled only by a blood clot and, in Group FAT (i.e., fragmented adipose tissue), the defect was filled with fragmented autogenous adipose tissue grafts. The groups were divided into subgroups (n = 7) for euthanasia at 7, 15, and 40 days after the procedure had been conducted. Histologic and histometric analyses were performed. Data were statistically analysed with ANOVA and Tukey’s tests (p < 0.05). Results The amount of bone formation did not show statistically significant differences seven days after the operation, which indicates that the groups had similar amounts of mineral deposition in the earlier period of the repair. Conversely, a significant of amount of bone matrix deposition was identified in the FAT group at 15 and 40 days following the operation, both on the border and in the body of the defect. Such an outcome was not found in the control group. Conclusion In this study, an autologous adipose tissue graft may be considered as likely biomaterial for bone regeneration, since it positively affected the amount of bone formation in surgically created CSD in the rabbits’ calvaria 40 days after the procedure had been performed. Further investigations with a longer time evaluation are warranted to determine the effectiveness of autologous adipose tissue graft in the bone healing. Key words

  16. Diagnosing, planning and evaluating osteochondral ankle defects with imaging modalities

    PubMed Central

    van Bergen, Christiaan JA; Gerards, Rogier M; Opdam, Kim TM; Terra, Maaike P; Kerkhoffs, Gino MMJ

    2015-01-01

    This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available. PMID:26716090

  17. Diagnosing, planning and evaluating osteochondral ankle defects with imaging modalities.

    PubMed

    van Bergen, Christiaan Ja; Gerards, Rogier M; Opdam, Kim Tm; Terra, Maaike P; Kerkhoffs, Gino Mmj

    2015-12-18

    This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available.

  18. Adipose tissue-derived stem cell-seeded small intestinal submucosa for tunica albuginea grafting and reconstruction

    PubMed Central

    Ma, Limin; Yang, Yijun; Sikka, Suresh C.; Kadowitz, Philip J.; Ignarro, Louis J.; Abdel-Mageed, Asim B.; Hellstrom, Wayne J. G.

    2012-01-01

    Porcine small intestinal submucosa (SIS) has been widely used in tunica albuginea (TA) reconstructive surgery. Adipose tissue-derived stem cells (ADSCs) can repair damaged tissue, augment cellular differentiation, and stimulate release of multiple growth factors. The aim of this rat study was to assess the feasibility of seeding ADSCs onto SIS grafts for TA reconstruction. Here, we demonstrate that seeding syngeneic ADSCs onto SIS grafts (SIS-ADSC) resulted in significant cavernosal tissue preservation and maintained erectile responses, similar to controls, in a rat model of bilateral incision of TA, compared with sham-operated animals and rats grafted with SIS graft (SIS) alone. In addition to increased TGF-β1 and FGF-2 expression levels, cross-sectional studies of the rat penis with SIS and SIS-ADSC revealed mild to moderate fibrosis and an increase of 30% and 40% in mean diameter in flaccid and erectile states, respectively. SIS grafting induced transcriptional up-regulation of iNOS and down-regulation of endothelial NOS, neuronal NOS, and VEGF, an effect that was restored by seeding ADCSs on the SIS graft. Taken together, these data show that rats undergoing TA incision with autologous SIS-ADSC grafts maintained better erectile function compared with animals grafted with SIS alone. This study suggests that SIS-ADSC grafting can be successfully used for TA reconstruction procedures and can restore erectile function. PMID:22308363

  19. Osteochondritis dissecans of the capitellum.

    PubMed

    Baker, Champ L; Romeo, Anthony A; Baker, Champ L

    2010-09-01

    Osteochondritis dissecans of the capitellum is a well-recognized cause of elbow pain and disability in the adolescent athlete. This condition typically affects young athletes, such as throwers and gymnasts, involved in high-demand, repetitive overhead, or weightbearing activities. The true cause, natural history, and optimal treatment of osteochondritis dissecans of the capitellum remain unknown. Suspicion of this condition warrants investigation with proper radiographs and magnetic resonance imaging. Prompt recognition of this disorder and institution of nonoperative treatment for early, stable lesions can result in healing with later resumption of sporting activities. Patients with unstable lesions or those failing nonoperative therapy require operative intervention with treatment based on lesion size and extent. Historically, surgical treatment included arthrotomy with loose body removal and curettage of the residual osteochondral defect base. The introduction of elbow arthroscopy in the treatment of osteochondritis dissecans of the capitellum permits a thorough lesion assessment and evaluation of the entire elbow joint with the ability to treat the lesion and coexistent pathology in a minimally invasive fashion. Unfortunately, the prognosis for advanced lesions remains more guarded, but short-term results after newer reconstruction techniques are promising.

  20. Altering the Architecture of Tissue Engineered Hypertrophic Cartilaginous Grafts Facilitates Vascularisation and Accelerates Mineralisation

    PubMed Central

    Sheehy, Eamon J.; Vinardell, Tatiana; Toner, Mary E.; Buckley, Conor T.; Kelly, Daniel J.

    2014-01-01

    Cartilaginous tissues engineered using mesenchymal stem cells (MSCs) can be leveraged to generate bone in vivo by executing an endochondral program, leading to increased interest in the use of such hypertrophic grafts for the regeneration of osseous defects. During normal skeletogenesis, canals within the developing hypertrophic cartilage play a key role in facilitating endochondral ossification. Inspired by this developmental feature, the objective of this study was to promote endochondral ossification of an engineered cartilaginous construct through modification of scaffold architecture. Our hypothesis was that the introduction of channels into MSC-seeded hydrogels would firstly facilitate the in vitro development of scaled-up hypertrophic cartilaginous tissues, and secondly would accelerate vascularisation and mineralisation of the graft in vivo. MSCs were encapsulated into hydrogels containing either an array of micro-channels, or into non-channelled ‘solid’ controls, and maintained in culture conditions known to promote a hypertrophic cartilaginous phenotype. Solid constructs accumulated significantly more sGAG and collagen in vitro, while channelled constructs accumulated significantly more calcium. In vivo, the channels acted as conduits for vascularisation and accelerated mineralisation of the engineered graft. Cartilaginous tissue within the channels underwent endochondral ossification, producing lamellar bone surrounding a hematopoietic marrow component. This study highlights the potential of utilising engineering methodologies, inspired by developmental skeletal processes, in order to enhance endochondral bone regeneration strategies. PMID:24595316

  1. Connective tissue graft vs. emdogain: A new approach to compare the outcomes

    PubMed Central

    Sayar, Ferena; Akhundi, Nasrin; Gholami, Sanaz

    2013-01-01

    Background: The aim of this clinical trial study was to clinically evaluate the use of enamel matrix protein derivative combined with the coronally positioned flap to treat gingival recession compared to the subepithelial connective tissue graft by a new method to obtain denuded root surface area. Materials and Methods: Thirteen patients, each with two or more similar bilateral Miller class I or II gingival recession (40 recessions) were randomly assigned to the test (enamel matrix protein derivative + coronally positioned flap) or control group (subepithelial connective tissue graft). Recession depth, width, probing depth, keratinized gingival, and plaque index were recorded at baseline and at one, three, and six months after treatment. A stent was used to measure the denuded root surface area at each examination session. Results were analyzed using Kolmogorov-Smirnov, Wilcoxon, Friedman, paired-sample t test. Results: The average percentages of root coverage for control and test groups were 63.3% and 55%, respectively. Both groups showed significant keratinized gingival increase (P < 0.05). Recession depth decreased significantly in both groups. Root surface area was improved significantly from baseline with no significant difference between the two study groups (P > 0.05). The results of Friedman test were significant for clinical indices (P < 0.05), except for probing depth in control group (P = 0.166). Conclusion: Enamel matrix protein derivative showed the same results as subepithelial connective tissue graft with relatively easy procedure to perform and low patient morbidity. PMID:23878562

  2. Chondrogenesis of Mesenchymal Stem Cells in an Osteochondral Environment Is Mediated by the Subchondral Bone

    PubMed Central

    de Vries–van Melle, Marloes L.; Narcisi, Roberto; Kops, Nicole; Koevoet, Wendy J.L.M.; Bos, P. Koen; Murphy, J. Mary; Verhaar, Jan A.N.; van der Kraan, Peter M.

    2014-01-01

    In articular cartilage repair, cells that will be responsible for the formation of repair tissue are often exposed to an osteochondral environment. To study cartilage repair mechanisms in vitro, we have recently developed a bovine osteochondral biopsy culture model in which cartilage defects can be simulated reproducibly. Using this model, we now aimed at studying the chondrogenic potential of human bone marrow-derived mesenchymal stem cells (hBMSCs) in an osteochondral environment. In contrast to standard in vitro chondrogenesis, it was found that supplementing transforming growth factor beta (TGFβ) to culture medium was not required to induce chondrogenesis of hBMSCs in an osteochondral environment. hBMSC culture in defects created in osteochondral biopsies or in bone-only biopsies resulted in comparable levels of cartilage-related gene expression, whereas culture in cartilage-only biopsies did not induce chondrogenesis. Subcutaneous implantation in nude mice of osteochondral biopsies containing hBMSCs in osteochondral defects resulted in the formation of more cartilaginous tissue than hBMSCs in chondral defects. The subchondral bone secreted TGFβ; however, the observed results could not be attributed to TGFβ, as either capturing TGFβ with an antibody or blocking the canonical TGFβ signaling pathway did not result in significant changes in cartilage-related gene expression of hBMSCs in the osteochondral culture model. Inhibition of BMP signaling did not prevent chondrogenesis. In conclusion, we demonstrate that chondrogenesis of hBMSCs is induced by factors secreted from the bone. We have strong indications that this is not solely mediated by members of the TGFβ family but other, yet unknown, factors originating from the subchondral bone appeared to play a key role. PMID:23980750

  3. Cyclic pull-out strength of hamstring tendon graft fixation with soft tissue interference screws. Influence of screw length.

    PubMed

    Stadelmaier, D M; Lowe, W R; Ilahi, O A; Noble, P C; Kohl, H W

    1999-01-01

    Blunt-threaded interference screws used for fixation of hamstring tendons in anterior cruciate ligament reconstructions provide aperture fixation and may provide a biomechanically more stable graft than a graft fixed further from the articular surface. It is unknown if soft tissue fixation strength using interference screws is affected by screw length. We compared the cyclic and time-zero pull-out forces of 7 x 25 mm and 7 x 40 mm blunt-threaded metal interference screws for hamstring graft tibial fixation in eight paired human cadaveric specimens. A four-stranded autologous hamstring tendon graft was secured by a blunt-threaded interference screw into a proximal tibial tunnel with a diameter corresponding to the graft width. Eight grafts were secured with a 25-mm length screw while the other eight paired grafts were secured with a 40-mm length screw. During cyclic testing, slippage of the graft occurred as the force of pull became greater with each cycle until the graft-screw complex ultimately failed. All grafts failed at the fixation site, with the tendon being pulled past the screw. There were no measurable differences in the mean cyclic failure strength, pull-out strength, or stiffness between the two sizes of screws. Although use of the longer screw would make removal technically easier should revision surgery be necessary, it did not provide stronger fixation strength than the shorter, standard screw as had been postulated. PMID:10569365

  4. Integrating biologically inspired nanomaterials and table-top stereolithography for 3D printed biomimetic osteochondral scaffolds

    NASA Astrophysics Data System (ADS)

    Castro, Nathan J.; O'Brien, Joseph; Zhang, Lijie Grace

    2015-08-01

    The osteochondral interface of an arthritic joint is notoriously difficult to regenerate due to its extremely poor regenerative capacity and complex stratified architecture. Native osteochondral tissue extracellular matrix is composed of numerous nanoscale organic and inorganic constituents. Although various tissue engineering strategies exist in addressing osteochondral defects, limitations persist with regards to tissue scaffolding which exhibit biomimetic cues at the nano to micro scale. In an effort to address this, the current work focused on 3D printing biomimetic nanocomposite scaffolds for improved osteochondral tissue regeneration. For this purpose, two biologically-inspired nanomaterials have been synthesized consisting of (1) osteoconductive nanocrystalline hydroxyapatite (nHA) (primary inorganic component of bone) and (2) core-shell poly(lactic-co-glycolic) acid (PLGA) nanospheres encapsulated with chondrogenic transforming growth-factor β1 (TGF-β1) for sustained delivery. Then, a novel table-top stereolithography 3D printer and the nano-ink (i.e., nHA + nanosphere + hydrogel) were employed to fabricate a porous and highly interconnected osteochondral scaffold with hierarchical nano-to-micro structure and spatiotemporal bioactive factor gradients. Our results showed that human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation were greatly improved in the biomimetic graded 3D printed osteochondral construct in vitro. The current work served to illustrate the efficacy of the nano-ink and current 3D printing technology for efficient fabrication of a novel nanocomposite hydrogel scaffold. In addition, tissue-specific growth factors illustrated a synergistic effect leading to increased cell adhesion and directed stem cell differentiation.

  5. Integrating biologically inspired nanomaterials and table-top stereolithography for 3D printed biomimetic osteochondral scaffolds.

    PubMed

    Castro, Nathan J; O'Brien, Joseph; Zhang, Lijie Grace

    2015-09-01

    The osteochondral interface of an arthritic joint is notoriously difficult to regenerate due to its extremely poor regenerative capacity and complex stratified architecture. Native osteochondral tissue extracellular matrix is composed of numerous nanoscale organic and inorganic constituents. Although various tissue engineering strategies exist in addressing osteochondral defects, limitations persist with regards to tissue scaffolding which exhibit biomimetic cues at the nano to micro scale. In an effort to address this, the current work focused on 3D printing biomimetic nanocomposite scaffolds for improved osteochondral tissue regeneration. For this purpose, two biologically-inspired nanomaterials have been synthesized consisting of (1) osteoconductive nanocrystalline hydroxyapatite (nHA) (primary inorganic component of bone) and (2) core-shell poly(lactic-co-glycolic) acid (PLGA) nanospheres encapsulated with chondrogenic transforming growth-factor β1 (TGF-β1) for sustained delivery. Then, a novel table-top stereolithography 3D printer and the nano-ink (i.e., nHA + nanosphere + hydrogel) were employed to fabricate a porous and highly interconnected osteochondral scaffold with hierarchical nano-to-micro structure and spatiotemporal bioactive factor gradients. Our results showed that human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation were greatly improved in the biomimetic graded 3D printed osteochondral construct in vitro. The current work served to illustrate the efficacy of the nano-ink and current 3D printing technology for efficient fabrication of a novel nanocomposite hydrogel scaffold. In addition, tissue-specific growth factors illustrated a synergistic effect leading to increased cell adhesion and directed stem cell differentiation.

  6. Design of a Novel 3D Printed Bioactive Nanocomposite Scaffold for Improved Osteochondral Regeneration

    PubMed Central

    Castro, Nathan J.; Patel, Romil; Zhang, Lijie Grace

    2015-01-01

    Chronic and acute osteochondral defects as a result of osteoarthritis and trauma present a common and serious clinical problem due to the tissue's inherent complexity and poor regenerative capacity. In addition, cells within the osteochondral tissue are in intimate contact with a 3D nanostructured extracellular matrix composed of numerous bioactive organic and inorganic components. As an emerging manufacturing technique, 3D printing offers great precision and control over the microarchitecture, shape and composition of tissue scaffolds. Therefore, the objective of this study is to develop a biomimetic 3D printed nanocomposite scaffold with integrated differentiation cues for improved osteochondral tissue regeneration. Through the combination of novel nano-inks composed of organic and inorganic bioactive factors and advanced 3D printing, we have successfully fabricated a series of novel constructs which closely mimic the native 3D extracellular environment with hierarchical nanoroughness, microstructure and spatiotemporal bioactive cues. Our results illustrate several key characteristics of the 3D printed nanocomposite scaffold to include improved mechanical properties as well as excellent cytocompatibility for enhanced human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation in vitro. The present work further illustrates the effectiveness of the scaffolds developed here as a promising and highly tunable platform for osteochondral tissue regeneration. PMID:26366231

  7. From natural bone grafts to tissue engineering therapeutics: Brainstorming on pharmaceutical formulative requirements and challenges.

    PubMed

    Baroli, Biancamaria

    2009-04-01

    Tissue engineering is an emerging multidisciplinary field of investigation focused on the regeneration of diseased or injured tissues through the delivery of appropriate molecular and mechanical signals. Therefore, bone tissue engineering covers all the attempts to reestablish a normal physiology or to speed up healing of bone in all musculoskeletal disorders and injuries that are lashing modern societies. This article attempts to give a pharmaceutical perspective on the production of engineered man-made bone grafts that are described as implantable tissue engineering therapeutics, and to highlight the importance of understanding bone composition and structure, as well as osteogenesis and bone healing processes, to improve the design and development of such implants. In addition, special emphasis is given to pharmaceutical aspects that are frequently minimized, but that, instead, may be useful for formulation developments and in vitro/in vivo correlations.

  8. Characterization of Evolving Biomechanical Properties of Tissue Engineered Vascular Grafts in the Arterial Circulation

    PubMed Central

    Udelsman, Brooks V.; Khosravi, Ramak; Miller, Kristin S.; Dean, Ethan W.; Bersi, Matthew R.; Rocco, Kevin; Yi, Tai; Humphrey, Jay D.; Breuer, Christopher K.

    2014-01-01

    We used a murine model to assess the evolving biomechanical properties of tissue engineered vascular grafts (TEVGs) implanted in the arterial circulation. The initial polymeric tubular scaffold was fabricated from (poly)lactic acid (PLA) and coated with a 50:50 copolymer of (poly)caprolactone and (poly)lactic acid (P[PC/LA]). Following seeding with syngeneic bone marrow derived mononuclear cells, the TEVGs (n=50) were implanted as aortic interposition grafts in wild-type mice and monitored serially using ultrasound. A custom biaxial mechanical testing device was used to quantify in vitro the circumferential and axial mechanical properties of grafts explanted at 3 or 7 months. At both times, the TEVGs were much stiffer than native tissue in both directions. Repeat mechanical testing of some TEVGs treated with elastase or collagenase suggested that elastin did not contribute significantly to the overall stiffness whereas collagen did contribute. Traditional histology and immunostaining revealed smooth muscle cell layers, significant collagen deposition, and increasing elastin production in addition to considerable scaffold at both 3 and 7 months, which likely dominated the high stiffness seen in mechanical testing. These results suggest that PLA has inadequate in vivo degradation, which impairs cell-mediated development of vascular neotissue having properties closer to native arteries. Assessing contributions of individual components, such as elastin and collagen, to the developing neovessel is needed to guide computational modeling that may help to optimize the design of the TEVG. PMID:24702863

  9. Characterization of evolving biomechanical properties of tissue engineered vascular grafts in the arterial circulation.

    PubMed

    Udelsman, Brooks V; Khosravi, Ramak; Miller, Kristin S; Dean, Ethan W; Bersi, Matthew R; Rocco, Kevin; Yi, Tai; Humphrey, Jay D; Breuer, Christopher K

    2014-06-27

    We used a murine model to assess the evolving biomechanical properties of tissue engineered vascular grafts (TEVGs) implanted in the arterial circulation. The initial polymeric tubular scaffold was fabricated from poly(lactic acid)(PLA) and coated with a 50:50 copolymer of poly(caprolactone) and poly(lactic acid)(P[PC/LA]). Following seeding with syngeneic bone marrow derived mononuclear cells, TEVGs (n=50) were implanted as aortic interposition grafts in wild-type mice and monitored serially using ultrasound. A custom biaxial mechanical testing device was used to quantify the in vitro circumferential and axial mechanical properties of grafts explanted at 3 or 7 months. At both times, TEVGs were much stiffer than native tissue in both directions. Repeated mechanical testing of some TEVGs treated with elastase or collagenase suggested that elastin did not contribute significantly to the overall stiffness whereas collagen did contribute. Traditional histology and immunostaining revealed smooth muscle cell layers, significant collagen deposition, and increasing elastin production in addition to considerable scaffold at both 3 and 7 months, which likely dominated the high stiffness seen in mechanical testing. These results suggest that PLA has inadequate in vivo degradation, which impairs cell-mediated development of vascular neotissue having properties closer to native arteries. Assessing contributions of individual components, such as elastin and collagen, to the developing neovessel is needed to guide computational modeling that may help to optimize the design of the TEVG. PMID:24702863

  10. Osteochondral diseases and fibrodysplasia ossificans progressiva.

    PubMed

    Morales-Piga, Antonio; Kaplan, Frederick S

    2010-01-01

    Osteochondrodysplasias like thanatophoric dysplasia, osteogenesis imperfecta, achondroplasia, and other genetic skeletal disorders like fibrodysplasia ossificans progressiva are infrequently seen in clinical practice. In cases of sporadic achondroplasia as well as in fibrodysplasia ossificans progressiva, there is a strong association with paternal age, a relationship that is less evident in other genetic osteochondral diseases. No other constitutional or environmental factor has proven to be associated with these disorders. The use of prenatal ultrasonography as a routine component of prenatal care is crucial in the early suspicion of osteochondrodysplasias whereas definitive diagnosis is usually obtained by pre-natal molecular analysis. In the case of fibrodysplasia ossificans progressiva, recognition of congenital great toe malformations associated with rapidly-appearing soft tissue swelling is sufficient to make the proper clinical diagnosis, which can be confirmed by genetic testing. Large regional centres will improve diagnosis performance, provide accurate genetic counselling, and ensure an integral assistance for these often severe and incapacitating conditions.

  11. The innate immune system contributes to tissue-engineered vascular graft performance

    PubMed Central

    Hibino, Narutoshi; Mejias, Dane; Pietris, Nicholas; Dean, Ethan; Yi, Tai; Best, Cameron; Shinoka, Toshiharu; Breuer, Christopher

    2015-01-01

    The first clinical trial of tissue-engineered vascular grafts (TEVGs) identified stenosis as the primary cause of graft failure. In this study, we aimed to elucidate the role of the host immune response in the development of stenosis using a murine model of TEVG implantation. We found that the C.B-17 wild-type (WT) mouse (control) undergoes a dramatic stenotic response, which is nearly completely abolished in the immunodeficient SCID/beige (bg) variant. SCID mice, which lack an adaptive immune system due to the absence of T and B lymphocytes, experienced rates of stenosis comparable to WT controls (average luminal diameter, WT: 0.071 ± 0.035 mm, SCID: 0.137 ± 0.032 mm, SCID/bg: 0.804 ± 0.039 mm; P < 0.001). The bg mutation is characterized by NK cell and platelet dysfunction, and systemic treatment of WT mice with either NK cell–neutralizing (anti–NK 1.1 antibody) or antiplatelet (aspirin/Plavix [clopidogrel bisulfate]; Asp/Pla) therapy achieved nearly half the patency observed in the SCID/bg mouse (NK Ab: 0.356 ± 0.151 mm, Asp/Pla: 0.452 ± 0.130 mm). Scaffold implantation elicited a blunted immune response in SCID/bg mice, as demonstrated by macrophage number and mRNA expression of proinflammatory cytokines in TEVG explants. Implicating the initial innate immune response as a critical factor in graft stenosis may provide a strategy for prognosis and therapy of second-generation TEVGs.—Hibino, N., Mejias, D., Pietris, N., Dean, E., Yi, T., Best, C., Shinoka, T., Breuer, C. The innate immune system contributes to tissue-engineered vascular graft performance. PMID:25713026

  12. Preparing Uniform-Thickness Corneal Endothelial Grafts from Donor Tissues Using a Non-Amplified Femtosecond Laser

    PubMed Central

    Singh, Kanwarpal; Haydari, Nour; Brunette, Isabelle; Costantino, Santiago

    2013-01-01

    Corneal grafts for Descemet’s Stripping Automated Endothelial Keratoplasty are commonly prepared using mechanical microkeratomes. However, the cuts produced in such way render corneal lenticules that are thinner centrally than peripherally, thus inducing a hyperopic shift. Here we describe a novel device for preparing donor corneal grafts, in which a single low-energy femtosecond laser system is used as both a light source for optical coherence tomography and for cutting the graft illuminating from the endothelial side. The same laser is first utilized to obtain three-dimensional optical coherence tomography images of the donor tissue for guiding the dissection and obtaining grafts of uniform thickness with no applanation or contact. This device allows an optimal procedure for preparing consistently thin posterior grafts for transplantation. PMID:24340090

  13. 3D printing of novel osteochondral scaffolds with graded microstructure.

    PubMed

    Nowicki, Margaret A; Castro, Nathan J; Plesniak, Michael W; Zhang, Lijie Grace

    2016-10-14

    Osteochondral tissue has a complex graded structure where biological, physiological, and mechanical properties vary significantly over the full thickness spanning from the subchondral bone region beneath the joint surface to the hyaline cartilage region at the joint surface. This presents a significant challenge for tissue-engineered structures addressing osteochondral defects. Fused deposition modeling (FDM) 3D bioprinters present a unique solution to this problem. The objective of this study is to use FDM-based 3D bioprinting and nanocrystalline hydroxyapatite for improved bone marrow human mesenchymal stem cell (hMSC) adhesion, growth, and osteochondral differentiation. FDM printing parameters can be tuned through computer aided design and computer numerical control software to manipulate scaffold geometries in ways that are beneficial to mechanical performance without hindering cellular behavior. Additionally, the ability to fine-tune 3D printed scaffolds increases further through our investment casting procedure which facilitates the inclusion of nanoparticles with biochemical factors to further elicit desired hMSC differentiation. For this study, FDM was used to print investment-casting molds innovatively designed with varied pore distribution over the full thickness of the scaffold. The mechanical and biological impacts of the varied pore distributions were compared and evaluated to determine the benefits of this physical manipulation. The results indicate that both mechanical properties and cell performance improve in the graded pore structures when compared to homogeneously distributed porous and non-porous structures. Differentiation results indicated successful osteogenic and chondrogenic manipulation in engineered scaffolds. PMID:27606933

  14. 3D printing of novel osteochondral scaffolds with graded microstructure

    NASA Astrophysics Data System (ADS)

    Nowicki, Margaret A.; Castro, Nathan J.; Plesniak, Michael W.; Zhang, Lijie Grace

    2016-10-01

    Osteochondral tissue has a complex graded structure where biological, physiological, and mechanical properties vary significantly over the full thickness spanning from the subchondral bone region beneath the joint surface to the hyaline cartilage region at the joint surface. This presents a significant challenge for tissue-engineered structures addressing osteochondral defects. Fused deposition modeling (FDM) 3D bioprinters present a unique solution to this problem. The objective of this study is to use FDM-based 3D bioprinting and nanocrystalline hydroxyapatite for improved bone marrow human mesenchymal stem cell (hMSC) adhesion, growth, and osteochondral differentiation. FDM printing parameters can be tuned through computer aided design and computer numerical control software to manipulate scaffold geometries in ways that are beneficial to mechanical performance without hindering cellular behavior. Additionally, the ability to fine-tune 3D printed scaffolds increases further through our investment casting procedure which facilitates the inclusion of nanoparticles with biochemical factors to further elicit desired hMSC differentiation. For this study, FDM was used to print investment-casting molds innovatively designed with varied pore distribution over the full thickness of the scaffold. The mechanical and biological impacts of the varied pore distributions were compared and evaluated to determine the benefits of this physical manipulation. The results indicate that both mechanical properties and cell performance improve in the graded pore structures when compared to homogeneously distributed porous and non-porous structures. Differentiation results indicated successful osteogenic and chondrogenic manipulation in engineered scaffolds.

  15. 3D printing of novel osteochondral scaffolds with graded microstructure.

    PubMed

    Nowicki, Margaret A; Castro, Nathan J; Plesniak, Michael W; Zhang, Lijie Grace

    2016-10-14

    Osteochondral tissue has a complex graded structure where biological, physiological, and mechanical properties vary significantly over the full thickness spanning from the subchondral bone region beneath the joint surface to the hyaline cartilage region at the joint surface. This presents a significant challenge for tissue-engineered structures addressing osteochondral defects. Fused deposition modeling (FDM) 3D bioprinters present a unique solution to this problem. The objective of this study is to use FDM-based 3D bioprinting and nanocrystalline hydroxyapatite for improved bone marrow human mesenchymal stem cell (hMSC) adhesion, growth, and osteochondral differentiation. FDM printing parameters can be tuned through computer aided design and computer numerical control software to manipulate scaffold geometries in ways that are beneficial to mechanical performance without hindering cellular behavior. Additionally, the ability to fine-tune 3D printed scaffolds increases further through our investment casting procedure which facilitates the inclusion of nanoparticles with biochemical factors to further elicit desired hMSC differentiation. For this study, FDM was used to print investment-casting molds innovatively designed with varied pore distribution over the full thickness of the scaffold. The mechanical and biological impacts of the varied pore distributions were compared and evaluated to determine the benefits of this physical manipulation. The results indicate that both mechanical properties and cell performance improve in the graded pore structures when compared to homogeneously distributed porous and non-porous structures. Differentiation results indicated successful osteogenic and chondrogenic manipulation in engineered scaffolds.

  16. Autologous osteochondral transplantation for simple cyst in the patella.

    PubMed

    Lu, Allen P; Hame, Sharon L

    2005-08-01

    Treatment options for chondral and osteochondral defects of the patella have been few and results have been inconsistent at best. Autologous osteochondral transplantation presents a new way to revisit these patellar defects. We report the case of a young female softball player with a simple cyst in the patella and an osteochondral defect that serves as the indication for autograft osteochondral transplantation.

  17. Collagen structural alterations contribute to stiffening of tissue after split-thickness skin grafting.

    PubMed

    Rosin, Nicole L; Agabalyan, Natacha; Olsen, Katherine; Martufi, Giampaol; Gabriel, Vincent; Biernaskie, Jeff; Di Martino, Elena S

    2016-03-01

    The gold standard treatment for full thickness injuries of the skin is autologous split-thickness skin grafting. This involves harvesting the epidermis and superficial dermis from healthy skin and transplanting it onto the prepared wound bed. The donor site regenerates spontaneously, but the appendages and cellular components from the dermal layer are excluded from the graft. As a result, the new tissue is inferior; the healed graft site is dry/itchy, has decreased elasticity, increased fragility, and altered sensory function. Because this dermal layer is composed of collagen and other extracellular matrix proteins, the aim was to characterize the changes in the dermal collagen after split thickness grafting that could contribute to a deficit in functionality. This will serve as a baseline for future studies designed to improve skin function using pharmacological or cell-based therapies for skin repair. A xenograft model whereby human split-thickness grafts were implanted into full-thickness defects on immunocompromised (athymic Nu/Nu) mice was used. The grafts were harvested 4 and 8 weeks later. The collagen microstructure was assessed with second harmonic generation with dual-photon microscopy and light polarization analysis. Collagen fiber stiffness and engagement stretch were estimated by fitting the results of biaxial mechanical tensile tests to a histo-mechanical constitutive model. The stiffness of the collagen fibril-proteoglycan complex increased from 682 ± 226 kPa/sr to 1016 ± 324 kPa/sr between 4 and 8 weeks postgrafting. At the microstructural level there were significant decreases in both thickness of collagen fibers (3.60 ± 0.34 μm vs. 2.10 ± 0.27 μm) and waviness ratio (2.04 ± 0.17 vs. 1.43 ± 0.08) of the collagen fibers postgrafting. The decrease of the macroscopic engagement stretch from 1.19 ± 0.11 to 1.09 ± 0.08 over time postgrafting mirrored the decrease in waviness measured at the microscopic level

  18. Alveolar Ridge Contouring with Free Connective Tissue Graft at Implant Placement: A 5-Year Consecutive Clinical Study.

    PubMed

    Hanser, Thomas; Khoury, Fouad

    2016-01-01

    This study evaluated volume stability after alveolar ridge contouring with free connective tissue grafts at implant placement in single-tooth gaps. A total of 52 single-tooth gaps with labial volume deficiencies in the maxilla (incisors, canines, and premolars) were consecutively treated with implants and concomitant free palatal connective tissue grafts in 46 patients between 2006 and 2009. Implants had to be covered with at least 2 mm peri-implant local bone after insertion. At implant placement, a free connective tissue graft from the palate was fixed inside a labial split-thickness flap to form an existing concave buccal alveolar ridge contour due to tissue volume deficiency into a convex shape. Standardized volumetric measurements of the labial alveolar contour using a template were evaluated before connective tissue grafting and at 2 weeks, 1 year, and 5 years after implantprosthetic incorporation. Tissue volume had increased significantly (P < .05) in all six reference points representing the outer alveolar soft tissue contour of the implant before connective tissue grafting to baseline (2 weeks after implant-prosthetic incorporation). Statistically, 50% of the reference points (P > .05) kept their volume from baseline to 1 year after prosthetic incorporation and from baseline to 5 years after prosthetic incorporation, respectively, whereas reference points located within the area of the implant sulcus showed a significant (P < .05) decrease in volume. Clinically, 5 years after prosthetic incorporation the originally concave buccal alveolar contour was still convex in all implants, leading to a continuous favorable anatomical shape and improved esthetic situation. Intraoral radiographs confirmed osseointegration and stable peri-implant parameters with a survival rate of 100% after a follow-up of approximately 5 years. Implant placement with concomitant free connective tissue grafting appears to be an appropriate long-term means to contour preexisting buccal

  19. Computationally Optimizing the Compliance of a Biopolymer Based Tissue Engineered Vascular Graft.

    PubMed

    Harrison, Scott; Tamimi, Ehab; Uhlorn, Josh; Leach, Tim; Vande Geest, Jonathan P

    2016-01-01

    Coronary heart disease is a leading cause of death among Americans for which coronary artery bypass graft (CABG) surgery is a standard surgical treatment. The success of CABG surgery is impaired by a compliance mismatch between vascular grafts and native vessels. Tissue engineered vascular grafts (TEVGs) have the potential to be compliance matched and thereby reduce the risk of graft failure. Glutaraldehyde (GLUT) vapor-crosslinked gelatin/fibrinogen constructs were fabricated and mechanically tested in a previous study by our research group at 2, 8, and 24 hrs of GLUT vapor exposure. The current study details a computational method that was developed to predict the material properties of our constructs for crosslinking times between 2 and 24 hrs by interpolating the 2, 8, and 24 hrs crosslinking time data. matlab and abaqus were used to determine the optimal combination of fabrication parameters to produce a compliance matched construct. The validity of the method was tested by creating a 16-hr crosslinked construct of 130 μm thickness and comparing its compliance to that predicted by the optimization algorithm. The predicted compliance of the 16-hr construct was 0.00059 mm Hg-1 while the experimentally determined compliance was 0.00065 mm Hg-1, a relative difference of 9.2%. Prior data in our laboratory has shown the compliance of the left anterior descending porcine coronary (LADC) artery to be 0.00071 ± 0.0003 mm Hg-1. Our optimization algorithm predicts that a 258-μm-thick construct that is GLUT vapor crosslinked for 8.1 hrs would match LADC compliance. This result is consistent with our previous work demonstrating that an 8-hr GLUT vapor crosslinked construct produces a compliance that is not significantly different from a porcine coronary LADC. PMID:26593773

  20. Porous tantalum biocomposites for osteochondral defect repair

    PubMed Central

    Mrosek, E. H.; Chung, H-W.; Fitzsimmons, J. S.; Reinholz, G. G.; Schagemann, J. C.

    2016-01-01

    Objectives We sought to determine if a durable bilayer implant composed of trabecular metal with autologous periosteum on top would be suitable to reconstitute large osteochondral defects. This design would allow for secure implant fixation, subsequent integration and remodeling. Materials and Methods Adult sheep were randomly assigned to one of three groups (n = 8/group): 1. trabecular metal/periosteal graft (TMPG), 2. trabecular metal (TM), 3. empty defect (ED). Cartilage and bone healing were assessed macroscopically, biochemically (type II collagen, sulfated glycosaminoglycan (sGAG) and double-stranded DNA (dsDNA) content) and histologically. Results At 16 weeks post-operatively, histological scores amongst treatment groups were not statistically different (TMPG: overall 12.7, cartilage 8.6, bone 4.1; TM: overall 14.2, cartilage 9.5, bone 4.9; ED: overall 13.6, cartilage 9.1, bone 4.5). Metal scaffolds were incorporated into the surrounding bone, both in TM and TMPG. The sGAG yield was lower in the neo-cartilage regions compared with the articular cartilage (AC) controls (TMPG 20.8/AC 39.5, TM 25.6/AC 33.3, ED 32.2/AC 40.2 µg sGAG/1 mg respectively), with statistical significance being achieved for the TMPG group (p < 0.05). Hypercellularity of the neo-cartilage was found in TM and ED, as the dsDNA content was significantly higher (p < 0.05) compared with contralateral AC controls (TM 126.7/AC 71.1, ED 99.3/AC 62.8 ng dsDNA/1 mg). The highest type II collagen content was found in neo-cartilage after TM compared with TMPG and ED (TM 60%/TMPG 40%/ED 39%). Inter-treatment differences were not significant. Conclusions TM is a highly suitable material for the reconstitution of osseous defects. TM enables excellent bony ingrowth and fast integration. However, combined with autologous periosteum, such a biocomposite failed to promote satisfactory neo-cartilage formation. Cite this article: E. H. Mrosek, H-W. Chung, J. S. Fitzsimmons, S. W. O’Driscoll, G. G

  1. Guided tissue regeneration and bone grafts in the treatment of furcation defects.

    PubMed

    Caffesse, R G; Nasjleti, C E; Plotzke, A E; Anderson, G B; Morrison, E C

    1993-11-01

    The present study evaluated the effects of guided tissue regeneration (GTR), with and without demineralized freeze-dried cortical bone grafts, in the treatment of furcation defects in 4 female beagle dogs with naturally occurring periodontal disease. The root surfaces were thoroughly debrided. Four weeks later, full thickness facial and lingual mucoperiosteal flaps were reflected using inverse bevel incisions on both sides of the mandible involving the 2nd, 3rd, and 4th premolar, and the 1st molar teeth. Following debridement, notches were placed on the roots at the level of supporting bone. Test quadrants were randomly selected and furcations were filled with reconstituted, demineralized, freeze-dried human cortical bone grafts. Following bone grafting, all defects were covered with an expanded polytetrafluoroethylene (ePTFE) membrane, which was sutured with 4-0 sutures. Afterward, interproximal sutures were placed through the flaps, assuring the flaps covered the membranes completely. The contralateral side, serving as control, was treated by debridement only and application of ePTFE membrane. All membranes were removed 6 weeks after surgery. Dogs were sacrificed at 4 months after surgery. Both mesio-distal and bucco-lingual histologic sections were evaluated by descriptive histology. Linear measurements and surface area determination of the furcal tissues were carried out using the microscope attached to a digitizer. Twelve to 20 nonserial sections were made of the mid-buccal aspects of each root of each treated tooth. Half of these sections were stained with Harris' hematoxylin and eosin (H&E) and the other half stained with Mallory's trichrome stain.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8295103

  2. Connective tissue-bone onlay graft with enamel matrix derivative for treatment of gingival recession: a case report.

    PubMed

    Nozawa, Takeshi; Sugiyama, Takahiko; Satoh, Tohru; Tanaka, Koji; Enomoto, Hiroaki; Ito, Koichi

    2002-12-01

    We describe a case of gingival recession in which root coverage and coronal bone regrowth were achieved after treatment with a connective tissue-bone graft and enamel matrix derivative. The connective tissue-bone graft was harvested from a maxillary edentulous area and then curved to fit the root surfaces of the maxillary left central and lateral incisors. Enamel matrix derivative was applied to the root surfaces, and the connective tissue-bone graft was fixed to the interdental bone by a titanium screw. Six months later, the exposed roots were covered with thick gingiva, and coronal regrowth of thick bone was evident at reentry surgery. This technique is useful for esthetic restoration placement with an intracrevicular margin on teeth with a thin, receding gingiva.

  3. Drilling techniques for osteochondritis dissecans.

    PubMed

    Heyworth, Benton E; Edmonds, Eric W; Murnaghan, M Lucas; Kocher, Mininder S

    2014-04-01

    Although the advanced stages of osteochondritis dissecans remain challenging to treat, most early-stage lesions in skeletally immature patients, if managed appropriately, can be stimulated to heal. For stable lesions that do not demonstrate adequate healing with nonoperative measures, such as activity modification, weight-bearing protection, or bracing, drilling of the subchondral bone has emerged as the gold standard of management. Several techniques of drilling exist, including transarticular drilling, retroarticular drilling, and notch drilling. Although each technique has been shown to be effective in small retrospective studies, higher-powered prospective comparative studies are needed to better elucidate their relative advantages and disadvantages.

  4. Late spontaneous nonanastomotic transgraft hemorrhage from biological material-impregnated fabric vascular graft may be due to autologous tissue detachment: a clinical hypothesis.

    PubMed

    Tomizawa, Yasuko

    2014-12-01

    Spontaneous nonanastomotic transgraft hemorrhage occurring several years after grafting may be a new late complication of biological material-impregnated fabric vascular grafts (BMIFVs). Autologous connective tissue detachment may be caused by high porosity of the fabric graft and high blood pressure. Bleeding around the fiber is the first sign of development. Fabric grafts with optimal porosity and biocompatibility should be used for manufacturing BMIFVs.

  5. Hybrid Matrix Grafts to Favor Tissue Regeneration in Rabbit Femur Bone Lesions

    PubMed Central

    Goy, Dante Pascual; Gorosito, Emmanuel; Costa, Hermes S; Mortarino, Pablo; Pedemonte, Noelia Acosta; Toledo, Javier; Mansur, Herman S; Pereira, Marivalda M; Battaglino, Ricardo; Feldman, Sara

    2012-01-01

    At present, typical approaches employed to repair fractures and other bone lesions tend to use matrix grafts to promote tissue regeneration. These grafts act as templates, which promote cellular adhesion, growth and proliferation, osteoconduction, and even osteoinduction, which commonly results in de novo osteogenesis. The present work aimed to study the bone-repairing ability of hybrid matrixes (HM) prepared with polyvinyl alcohol (PVA) and bioactive glass in an experimental rabbit model. The HM were prepared by combining 30% bioactive glass (nominal composition of 58% SiO2 -33 % CaO - 9% P2O5) and 70% PVA. New Zealand rabbits were randomly divided into the control group (C group) and two groups with bone lesions, in which one received a matrix implant HM (Implant group), while the other did not (no Implant group). Clinical monitoring showed no altered parameters from either the Implant or the no Implant groups as compared to the control group, for the variables of diet grades, day and night temperatures and hemograms. In the Implant group, radiologic and tomographic studies showed implanted areas with clean edges in femoral non-articular direction, and radio-dense images that suggest incipient integration. Minimum signs of phlogosis could be observed, whereas no signs of rejection at this imaging level could be identified. Histological analysis showed evidence of osteo-integration, with the formation of a trabecular bone within the implant. Together, these results show that implants of hybrid matrixes of bioactive glass are capable of promoting bone regeneration. PMID:22848334

  6. Polyphenol-Stabilized Tubular Elastin Scaffolds for Tissue Engineered Vascular Grafts

    PubMed Central

    Chuang, Ting-Hsien; Stabler, Christopher; Simionescu, Agneta

    2009-01-01

    Tissue-engineered vascular grafts require elastic, acellular porous scaffolds with controlled biodegradability and properties matching those of natural arteries. Elastin would be a desirable component for such applications, but elastin does not easily regenerate experimentally. Our approach is to develop tubular elastin scaffolds using decellularization and removal of collagen from porcine carotid arteries (∼5 mm diameter) using alkaline extraction. Because elastin is susceptible to rapid degeneration after implantation, scaffolds were further treated with penta-galloyl glucose (PGG), an established polyphenolic elastin-stabilizing agent. Scaffolds were compared in vitro with detergent-decellularized arteries for structure, composition, resistance to degradation, mechanical properties, and cytotoxicity and in vivo for cell infiltration and remodeling potential. Results showed effective decellularization and almost complete collagen removal by alkaline extraction. PGG-treated elastin scaffolds proved to be resistant to elastase digestion in vitro, maintained their cylindrical shapes, showed high resistance to burst pressures, and supported growth of endothelial cells and fibroblasts. In vivo results showed that PGG treatment reduced the rate of elastin biodegradation and controlled cell infiltration but did not hamper new collagen and proteoglycan deposition and secretion of matrix-degrading proteases. Alkali-purified, PGG-treated tubular arterial elastin scaffolds exhibit many desirable properties to be recommended for clinical applications as vascular grafts. PMID:19254115

  7. Clinical Comparison of Full and Partial Double Pedicle Flaps with Connective Tissue Grafts for Treatment of Gingival Recession

    PubMed Central

    Ranjbari, Ardeshir; Gholami, Gholam Ali; Amid, Reza; Kadkhodazadeh, Mahdi; Youssefi, Navid; Mehdizadeh, Amir Reza; Aghaloo, Maryam

    2016-01-01

    Statement of the Problem Gingival recession has been considered as the most challenging issue in the field of periodontal plastic surgery. Purpose The purpose of this study was to evaluate the clinical efficacy of root coverage procedures by using partial thickness double pedicle graft and compare it with full thickness double pedicle graft. Materials and Method Eight patients, aged 15 to 58 years including 6 females and 2 males with 20 paired (mirror image) defects with class I and II gingival recession were randomly assigned into two groups. Clinical parameters such as recession depth, recession width, clinical attachment level, probing depth, and width of keratinized tissue were measured at the baseline and 6 months post-surgery. A mucosal double papillary flap was elevated and the respective root was thoroughly planed. The connective tissue graft was harvested from the palate, and then adapted over the root. The pedicle flap was secured over the connective tissue graft and sutured. The surgical technique was similar in the control group except for the prepared double pedicle graft which was full thickness. Results The mean root coverage was 88.14% (2.83 mm) in the test group and 85.7% (2.75 mm) in the control group. No statistical differences were found in the mean reduction of vertical recession, width of recession, or probing depth between the test and control groups. In both procedures, the width of keratinized tissue increased after three months and the difference between the two groups was not statistically significant in this respect. Conclusion Connective tissue with partial and full thickness double pedicle grafts can be successfully used for treatment of marginal gingival recession.

  8. Clinical Comparison of Full and Partial Double Pedicle Flaps with Connective Tissue Grafts for Treatment of Gingival Recession

    PubMed Central

    Ranjbari, Ardeshir; Gholami, Gholam Ali; Amid, Reza; Kadkhodazadeh, Mahdi; Youssefi, Navid; Mehdizadeh, Amir Reza; Aghaloo, Maryam

    2016-01-01

    Statement of the Problem Gingival recession has been considered as the most challenging issue in the field of periodontal plastic surgery. Purpose The purpose of this study was to evaluate the clinical efficacy of root coverage procedures by using partial thickness double pedicle graft and compare it with full thickness double pedicle graft. Materials and Method Eight patients, aged 15 to 58 years including 6 females and 2 males with 20 paired (mirror image) defects with class I and II gingival recession were randomly assigned into two groups. Clinical parameters such as recession depth, recession width, clinical attachment level, probing depth, and width of keratinized tissue were measured at the baseline and 6 months post-surgery. A mucosal double papillary flap was elevated and the respective root was thoroughly planed. The connective tissue graft was harvested from the palate, and then adapted over the root. The pedicle flap was secured over the connective tissue graft and sutured. The surgical technique was similar in the control group except for the prepared double pedicle graft which was full thickness. Results The mean root coverage was 88.14% (2.83 mm) in the test group and 85.7% (2.75 mm) in the control group. No statistical differences were found in the mean reduction of vertical recession, width of recession, or probing depth between the test and control groups. In both procedures, the width of keratinized tissue increased after three months and the difference between the two groups was not statistically significant in this respect. Conclusion Connective tissue with partial and full thickness double pedicle grafts can be successfully used for treatment of marginal gingival recession. PMID:27602394

  9. Long-term storage and preservation of tissue engineered articular cartilage.

    PubMed

    Nover, Adam B; Stefani, Robert M; Lee, Stephanie L; Ateshian, Gerard A; Stoker, Aaron M; Cook, James L; Hung, Clark T

    2016-01-01

    With limited availability of osteochondral allografts, tissue engineered cartilage grafts may provide an alternative treatment for large cartilage defects. An effective storage protocol will be critical for translating this technology to clinical use. The purpose of this study was to evaluate the efficacy of the Missouri Osteochondral Allograft Preservation System (MOPS) for room temperature storage of mature tissue engineered grafts, focusing on tissue property maintenance during the current allograft storage window (28 days). Additional research compares MOPS to continued culture, investigates temperature influence, and examines longer-term storage. Articular cartilage constructs were cultured to maturity using adult canine chondrocytes, then preserved with MOPS at room temperature, in refrigeration, or kept in culture for an additional 56 days. MOPS storage maintained desired chondrocyte viability for 28 days of room temperature storage, retaining 75% of the maturity point Young's modulus without significant decline in biochemical content. Properties dropped past this time point. Refrigeration maintained properties similar to room temperature at 28 days, but proved better at 56 days. For engineered grafts, MOPS maintained the majority of tissue properties for the 28-day window without clearly extending that period as it had for native grafts. These results are the first evaluating engineered cartilage storage.

  10. Electrospinning of aniline pentamer-graft-gelatin/PLLA nanofibers for bone tissue engineering.

    PubMed

    Liu, Yadong; Cui, Haitao; Zhuang, Xiuli; Wei, Yen; Chen, Xuesi

    2014-12-01

    Blends of aniline pentamer-graft-gelatin (AP-g-GA) and poly(l-lactide) (PLLA) were electrospun to prepare uniform nanofibers as biomimetic scaffolds. The nanofibers exhibited good electroactivity, thermal stability and biodegradability. The biocompatibility of the nanofibers in vitro was evaluated by the adhesion and proliferation of mouse preosteoblastic MC3T3-E1 cells. The cellular elongation was significantly greater on electroactive AP-g-GA/PLLA nanofibers than on PLLA nanofibers. Moreover, the AP-g-GA/PLLA nanofibers stimulated by an electrical pulsed signal could promote the differentiation of MC3T3-E1 cells compared with pure PLLA nanofibers. Our results demonstrated that the biodegradable and electroactive AP-g-GA/PLLA nanofibers had potential application in vivo as bone repair scaffold materials in tissue engineering.

  11. Treatment of noncarious cervical lesions by a subepithelial connective tissue graft versus a composite resin restoration.

    PubMed

    Leybovich, Martin; Bissada, Nabil F; Teich, Sorin; Demko, Catherine A; Ricchetti, Paul A

    2014-01-01

    This study compared two treatments for mild noncarious cervical lesions (NCCLs): a subepithelial connective tissue graft (CTG) versus a Class V composite resin restoration (CRR). Twenty-six sites with NCCLs were randomly assigned to be treated by CTG or CRR. Periodontal health parameters and dentinal hypersensitivity (DH) were recorded at baseline and 3 months postoperatively. Esthetics was also evaluated at 3 months. Results showed a significant improvement in all periodontal health parameters in the CTG treatment. The CTG treatment attained a mean 82% defect coverage with 75% of sites achieving complete coverage. Patients rated the CTG treatment to be significantly more esthetic (P = .03), while a clinician panel did not see an esthetic difference (P = .86). There was no difference in DH reduction between the two treatments (P = .81). In conclusion, the CTG treatment is superior to the CRR treatment for NCCLs based on periodontal health parameters. From a patient point of view, the CTG is the more esthetic treatment.

  12. Treatment of noncarious cervical lesions by a subepithelial connective tissue graft versus a composite resin restoration.

    PubMed

    Leybovich, Martin; Bissada, Nabil F; Teich, Sorin; Demko, Catherine A; Ricchetti, Paul A

    2014-01-01

    This study compared two treatments for mild noncarious cervical lesions (NCCLs): a subepithelial connective tissue graft (CTG) versus a Class V composite resin restoration (CRR). Twenty-six sites with NCCLs were randomly assigned to be treated by CTG or CRR. Periodontal health parameters and dentinal hypersensitivity (DH) were recorded at baseline and 3 months postoperatively. Esthetics was also evaluated at 3 months. Results showed a significant improvement in all periodontal health parameters in the CTG treatment. The CTG treatment attained a mean 82% defect coverage with 75% of sites achieving complete coverage. Patients rated the CTG treatment to be significantly more esthetic (P = .03), while a clinician panel did not see an esthetic difference (P = .86). There was no difference in DH reduction between the two treatments (P = .81). In conclusion, the CTG treatment is superior to the CRR treatment for NCCLs based on periodontal health parameters. From a patient point of view, the CTG is the more esthetic treatment. PMID:25171035

  13. Haemostatic effects of laser tissue solder as a reinforcement to anastomoses with PTFE grafts

    NASA Astrophysics Data System (ADS)

    Birch, Jeremy F.; Seifalian, Alexander M.; Bell, Peter R.

    2003-06-01

    Laser activated tissue solders have been used for sutureless anastomosis in various contexts. Solders were initially developed in response to the finding that the use of lasers alone caused vessel damage resulting in aneurysm formation and medical damage. Many reports exist of the use of lasers to perform micro-anastomoses, but little has been reported on the use of laser tissue solder in the formation of medium sized vessel anastomoses or in vivo. This group has recently developed a methylene blue based albumin solder for use in vascular anastomoses. The early work concentrated on a rabbit carotid end-to-end model. More recently this has progressed into its application in medium sized vessels. The use of PTFE is common in clinical practice particularly relating to peripheral vascular reconstruction or vascular access surgery. In these instances conventional surgical techniques applied to PTFE will result in excessive bleeding at the site of the anastomosis. Suture materials commonly used such as polypropylene or polyamide leave holes in such prostheses. To compound the problem patients are often anticoagulated or suffer impaired platelet function, improving the chances of graft survival, but increasing bleeding time, the time required to achieve haemostasis and also the post operative complications related to bleeding such as haematoma formation. It was therefore intended to apply the techniques of soldered vascular anastomoses to such a scenario, by reinforcing the anastomotic suture line of grafts placed in an animal model, with MB based solder. The bleeding times, overall operating times and postoperative complications were then analyzed and compared to sutured controls.

  14. Mosaicplasty for the treatment of osteochondritis dissecans following Legg-Calvé-Perthes disease: a case report and literature review.

    PubMed

    Gagala, Jacek; Tarczynska, Marta; Gaweda, Krzysztof

    2015-01-01

    Legg-Calvé-Perthes disease leads to hip joint deformity. Osteochondritis dissecans following Perthes disease (OCDP) is a less common entity. Treatment options of OCDP are limited. Osteochondral autologous transfer (OATS) is an established method of treatment of full thickness cartilage defects in different locations. This paper presents the case of a 42-year-old patient diagnosed with symptomatic OCDP and treated with lesion fixation using autologous osteochondral grafts via surgical hip dislocation. At the most recent follow-up, 5.5 years after the surgery, the patient did not complain of any pain during rest or activity. He had painless motion with persisting abduction and internal rotation reduction. Harris hip score (HHS) improved from preoperative 62 to 92 points at most recent follow-up. Treatment protocol was discussed in relation to the literature regarding this clinical topic. PMID:26511699

  15. Tissue engineering of acellular vascular grafts capable of somatic growth in young lambs

    PubMed Central

    Syedain, Zeeshan; Reimer, Jay; Lahti, Matthew; Berry, James; Johnson, Sandra; Tranquillo, Robert T.

    2016-01-01

    Treatment of congenital heart defects in children requiring right ventricular outflow tract reconstruction typically involves multiple open-heart surgeries because all existing graft materials have no growth potential. Here we present an ‘off-the-shelf' vascular graft grown from donor fibroblasts in a fibrin gel to address this critical unmet need. In a proof-of-concept study, the decellularized grafts are implanted as a pulmonary artery replacement in three young lambs and evaluated to adulthood. Longitudinal ultrasounds document dimensional growth of the grafts. The lambs show normal growth, increasing body weight by 366% and graft diameter and volume by 56% and 216%, respectively. Explanted grafts display physiological strength and stiffness, complete lumen endothelialization and extensive population by mature smooth muscle cells. The grafts also show substantial elastin deposition and a 465% increase in collagen content, without signs of calcification, aneurysm or stenosis. Collectively, our data support somatic growth of this completely biological graft. PMID:27676438

  16. Functionality, growth and accelerated aging of tissue engineered living autologous vascular grafts.

    PubMed

    Kelm, Jens M; Emmert, Maximilian Y; Zürcher, Armin; Schmidt, Dörthe; Begus Nahrmann, Yvonne; Rudolph, Karl L; Weber, Benedikt; Brokopp, Chad E; Frauenfelder, Thomas; Leschka, Sebastian; Odermatt, Bernhard; Jenni, Rolf; Falk, Volkmar; Zünd, Gregor; Hoerstrup, Simon P

    2012-11-01

    Living autologous tissue engineered vascular-grafts (TEVGs) with growth-capacity may overcome the limitations of contemporary artificial-prostheses. However, the multi-step in vitro production of TEVGs requires extensive ex vivo cell-manipulations with unknown effects on functionality and quality of TEVGs due to an accelerated biological age of the cells. Here, the impact of biological cell-age and tissue-remodeling capacity of TEVGs in relation to their clinical long-term functionality are investigated. TEVGs were implanted as pulmonary-artery (PA) replacements in juvenile sheep and followed for up to 240 weeks (∼4.5years). Telomere length and telomerase activity were compared amongst TEVGs and adjacent native tissue. Telomerase-activity of in vitro expanded autologous vascular-cells prior to seeding was <5% as compared to a leukemic cell line, indicating biological-aging associated with decreasing telomere-length with each cellular-doubling. Up to 100 weeks, the cells in the TEVGs had consistently shorter telomeres compared to the native counterpart, whereas no significant differences were detectable at 240 weeks. Computed tomography (CT) analysis demonstrated physiological wall-pressures, shear-stresses, and flow-pattern comparable to the native PA. There were no signs of degeneration detectable and continuous native-analogous growth was confirmed by vessel-volumetry. TEVGs exhibit a higher biological age compared to their native counterparts. However, despite of this tissue engineering technology related accelerated biological-aging, growth-capacity and long-term functionality was not compromised. To the contrary, extensive in-vivo remodeling processes with substantial endogenous cellular turnover appears to result in "TEVG rejuvenation" and excellent clinical performance. As these large-animal results can be extrapolated to approximately 20 human years, this study suggests long-term clinical-safety of cardiovascular in vitro tissue engineering and may

  17. Calcaneal osteochondritis: a new overuse injury.

    PubMed

    Lokiec, F; Wientroub, S

    1998-07-01

    This is a case report of osteochondritis of the medial plantar apophysis of the calcaneus presenting as medial plantar heel pain in a 15-year-old basketball player. The lesion was detected radiographically and by increased focal uptake on bone scan. Conservative treatment resulted in complete pain relief and normal calcaneal appearance with union of the osteochondral fragment. No recurrence was noted during 3 years of follow-up.

  18. The tent pole splint: a bone-supported stereolithographic surgical splint for the soft tissue matrix expansion graft procedure.

    PubMed

    Cillo, Joseph E; Theodotou, Nicholas; Samuels, Marc; Krajekian, Joseph

    2010-06-01

    This report details the use of computer-aided planning and intraoperative stereolithographic direct-bone-contact surgical splints for the accurate extraoral placement of dental implants in the soft tissue matrix expansion (tent pole) graft of the severely resorbed mandible. PMID:20231048

  19. A tissue engineered renovascular graft composed of proteins, polymers, smooth muscle and endothelial cells for renal artery stenosis.

    PubMed

    Yin, Hao; Wang, Xiao-Hui; Zhu, Xiang-Dong; Han, Huifang; Guo, Wen-Yuan; Ful, Zhi-Ren

    2013-08-01

    Endarterectomy and bypass surgery to treat renal artery stenosis are increasingly shunned these days due to high risks of complications during and after the surgery. Striving to find a sound alternative solution, we pioneered the construction of a tissue engineered renovascular graft that could immediately restore the normal blood flow to kidneys and sustain renal functions without suffering restenosis after the surgery. A highly porous scaffold was first constructed by electrospinning polycaprolactone, poliglecaprone, gelatin and elastin, giving the vast majority of non-woven fibers in the scaffold a diameter below 1200 nm. To recapitulate the anatomical and functional signatures of renal arteries, a bi-layer vasculature comprising a smooth muscle layer topped by an endothelial layer was built on the scaffold. The vasculature witnessed a sustained proliferation for up to 10 days in vitro and robustly secreted prostacyclin and endothelin-1, evidencing that the vasculature was functionally comparable to native renal arteries. After 30 days as a renovascular graft in mice, the luminal diameter of the graft remained clear without a restenosis and an increased confluence of the endothelial layer was observed. The tensile test confirmed that the renovascular graft was mechanically superior to native renal arteries and retained this advantage within 30 days in vivo. Also, this renovascular graft sustained renal functions as evidenced by normal levels of serum creatinine, urine creatinine and serum urea nitrogen and the lack of edema in the kidney cortex. These results demonstrate that this renovascular graft holds a great therapeutic promise for renal artery stenosis.

  20. A New Medical Device Rigeneracons Allows to Obtain Viable Micro-Grafts From Mechanical Disaggregation of Human Tissues.

    PubMed

    Trovato, Letizia; Monti, Manuela; Del Fante, Claudia; Cervio, Marila; Lampinen, Milla; Ambrosio, Lucia; Redi, Carlo Alberto; Perotti, Cesare; Kankuri, Esko; Ambrosio, Gennaro; Rodriguez Y Baena, Ruggero; Pirozzi, Giuseppe; Graziano, Antonio

    2015-10-01

    Autologous graft is considered the gold standard of graft materials; however, this approach is still limited due to both small amount of tissue that can be collected and to reduced cell viability of cells that can be obtained. The aim of this preliminary study was to demonstrate the efficacy of an innovative medical device called Rigeneracons® (CE certified Class I) to provide autologous micro-grafts immediately available to be used in the clinical practice. Moreover, Rigeneracons® is an instrument able to create micro-grafts enriched of progenitors cells which maintain their regenerative and differentiation potential. We reported preliminary data about viability cell of samples derived from different kind of human tissues, such as periosteum, cardiac atrial appendage biopsy, and lateral rectus muscle of eyeball and disaggregated by Rigeneracons®. In all cases we observed that micro-grafts obtained by Rigeneracons® displayed high cell viability. Furthermore, by cell characterization of periosteum samples, we also evidenced an high positivity to mesenchymal cell markers, suggesting an optimal regenerative potential.

  1. Surgical management of osteochondritis dissecans of the capitellum.

    PubMed

    Tivnon, M C; Anzel, S H; Waugh, T R

    1976-01-01

    Ten cases of osteochondritis dissecans of the humeral capitellum which were treated surgically are reviewed. All 10 cases were males and involved the dominant side. The ages at surgery ranged from 13 to 17 years. Follow-up ranged from 1 to 7 years. All of the youths had competed in organized athletics, either baseball or football. By position there were three pitchers, two catchers, two infielders, and one outfielder; in addition there were one quarterback and one linebacker. Only one patient presented with locking of the elbow, whereas the others presented with pain and limitation of extension. The locked elbow was explored immediately and the others were explored after immobilization failed to relieve their symptoms. In seven of the joints a loose fragment of the capitellum was found lying either in the joint or in a defect in the capitellum. The fragment had multiple small holes. In three cases there was no loose fragment. In this situation a corticol window was cut above the capitellum. The capitellum was then drilled and bone was grafted from above. Over all, there were one excellent, six good, one fair, and two poor results. There seemed to be little difference between curretting alone or curetting and drilling. The cases with the cartilage intact and bone grafted from above did worse, with one fair and one poor result of three cases. The two poor results required further surgery, which consisted of partial excision of the capitellum. All cases lacked elbow extension before and after surgery, but nine of 10 gained some motion after surgery. Pre- and postoperative x-rays are shown in this report and a brief review of the literature concerning osteochondritis dissecans is presented.

  2. USPIO-labeled textile materials for non-invasive MR imaging of tissue-engineered vascular grafts.

    PubMed

    Mertens, Marianne E; Koch, Sabine; Schuster, Philipp; Wehner, Jakob; Wu, Zhuojun; Gremse, Felix; Schulz, Volkmar; Rongen, Lisanne; Wolf, Frederic; Frese, Julia; Gesché, Valentine N; van Zandvoort, Marc; Mela, Petra; Jockenhoevel, Stefan; Kiessling, Fabian; Lammers, Twan

    2015-01-01

    Non-invasive imaging might assist in the clinical translation of tissue-engineered vascular grafts (TEVG). It can e.g. be used to facilitate the implantation of TEVG, to longitudinally monitor their localization and function, and to provide non-invasive and quantitative feedback on their remodeling and resorption. We here incorporated ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles into polyvinylidene fluoride (PVDF)-based textile fibers, and used them to prepare imageable tissue-engineered vascular grafts (iTEVG). The USPIO-labeled scaffold materials were molded with a mixture of fibrin, fibroblasts and smooth muscle cells, and then endothelialized in a bioreactor under physiological flow conditions. The resulting grafts could be sensitively detected using T1-, T2- and T2*-weighted MRI, both during bioreactor cultivation and upon surgical implantation into sheep, in which they were used as an arteriovenous shunt between the carotid artery and the jugular vein. In vivo, the iTEVG were shown to be biocompatible and functional. Post-mortem ex vivo analyses provided evidence for efficient endothelialization and for endogenous neo-vascularization within the biohybrid vessel wall. These findings show that labeling polymer-based textile materials with MR contrast agents is straightforward and safe, and they indicate that such theranostic tissue engineering approaches might be highly useful for improving the production, performance, personalization and translation of biohybrid vascular grafts.

  3. USPIO-labeled textile materials for non-invasive MR imaging of tissue-engineered vascular grafts.

    PubMed

    Mertens, Marianne E; Koch, Sabine; Schuster, Philipp; Wehner, Jakob; Wu, Zhuojun; Gremse, Felix; Schulz, Volkmar; Rongen, Lisanne; Wolf, Frederic; Frese, Julia; Gesché, Valentine N; van Zandvoort, Marc; Mela, Petra; Jockenhoevel, Stefan; Kiessling, Fabian; Lammers, Twan

    2015-01-01

    Non-invasive imaging might assist in the clinical translation of tissue-engineered vascular grafts (TEVG). It can e.g. be used to facilitate the implantation of TEVG, to longitudinally monitor their localization and function, and to provide non-invasive and quantitative feedback on their remodeling and resorption. We here incorporated ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles into polyvinylidene fluoride (PVDF)-based textile fibers, and used them to prepare imageable tissue-engineered vascular grafts (iTEVG). The USPIO-labeled scaffold materials were molded with a mixture of fibrin, fibroblasts and smooth muscle cells, and then endothelialized in a bioreactor under physiological flow conditions. The resulting grafts could be sensitively detected using T1-, T2- and T2*-weighted MRI, both during bioreactor cultivation and upon surgical implantation into sheep, in which they were used as an arteriovenous shunt between the carotid artery and the jugular vein. In vivo, the iTEVG were shown to be biocompatible and functional. Post-mortem ex vivo analyses provided evidence for efficient endothelialization and for endogenous neo-vascularization within the biohybrid vessel wall. These findings show that labeling polymer-based textile materials with MR contrast agents is straightforward and safe, and they indicate that such theranostic tissue engineering approaches might be highly useful for improving the production, performance, personalization and translation of biohybrid vascular grafts. PMID:25465443

  4. Methylcellulose during cryopreservation of ventral mesencephalic tissue fragments fails to improve survival and function of cell suspension grafts.

    PubMed

    Sautter, J; Strecker, S; Kupsch, A; Oertel, W H

    1996-02-01

    Cryopreservation may allow long-term storage of fetal ventral mesencephalon (VM) for transplantation in patients suffering from Parkinson's disease (PD). We investigated whether the polymer methylcellulose protects fetal rat VM during cryopreservation in liquid nitrogen and improves survival and function of this tissue as intrastriatal suspension grafts in the 6-hydroxydopamine (6-OHDA) rat model. VM tissue fragments (E14-E15) were either immediately dissociated and grafted as a cell suspension (FRESH) or cryopreserved under controlled conditions for 7 days in a conventional cryoprotective medium (CRYO) or a medium containing 0.1% methylcellulose (mCRYO) and then dissociated and grafted. Rats from the cryo-groups showed only limited behavioral compensation in contrast to complete compensation observed in rats from the FRESH group. Cryopreservation of fetal rat VM decreased the viability of cell suspensions in vitro to about 70%, survival of grafted tyrosine hydroxylase-immunoreactive (TH-IR) neurons to 11% and 20%, and transplant volume to 8% and 17% (mCRYO and CRYO, respectively, compared to FRESH). The addition of 0.1% methylcellulose to tissue fragments during freezing did neither improve in vitro viability nor survival of TH-IR neurons nor behavioral compensation when compared to the control CRYO group. These results suggest that methylcellulose failed to improve survival of cryopreserved dopaminergic ventral mesencephalic neurons.

  5. Clinical evaluation of expanded mesh connective tissue graft in the treatment for multiple adjacent gingival recessions in the esthetic zone

    PubMed Central

    Shanmugam, M.; Shivakumar, B.; Meenapriya, B.; Anitha, V.; Ashwath, B.

    2015-01-01

    Background: Multiple approaches have been used to replace lost, damaged or diseased gingival tissues. The connective tissue graft (CTG) procedure is the golden standard method for root coverage. Although multiple sites often need grafting, the palatal mucosa supplies only a limited area of grafting material. To overcome this limitation, expanded mesh graft provides a method whereby a graft can be stretched to cover a large area. The aim of this study was to evaluate the effectiveness and the predictability of expanded mesh CTG (e-MCTG) in the treatment of adjacent multiple gingival recessions. Materials and Methods: Sixteen patients aged 20–50 years contributed to 55 sites, each site falling into at least three adjacent Miller's Class 1 or Class 2 gingival recession. The CTG obtained from the palatal mucosa was expanded to cover the recipient bed, which was 1.5 times larger than the graft. Clinical measurements were recorded at baseline and 3 months, 12 months postoperatively. Results: A mean coverage of 1.96 mm ± 0.66 mm and 2.22 mm ± 0.68 mm was obtained at the end of 3rd and 12th month, respectively. Twelve months after surgery a statistically significant increase in CAL (2.2 mm ± 0.68 mm, P < 0.001) and increasing WKT (1.75 ± 0.78, P < 0.001) were obtained. In 80% of the treated sites, 100% root coverage was achieved (mean 93.5%). Conclusions: The results of this study demonstrated that multiple adjacent recessions were treated by using e-MCTG technique can be applied and highly predictable root coverage can be achieved. PMID:26321829

  6. Use of subepithelial connective tissue graft as a biological barrier: a human clinical and histologic case report.

    PubMed

    Santagata, Mario; Guariniello, Luigi; Prisco, Rosario V E; Tartaro, Gianpaolo; D'Amato, Salvatore

    2014-08-01

    The aim of the present study was to develop a method to study the healing process after gingival grafting and to observe the histologic results after use of the modified edentulous ridge expansion technique. A 47-year-old nonsmoking woman with a noncontributory past medical history affected by edentulism associated with a horizontal alveolar ridge defect was referred to the authors for surgical correction of the deficit to improve implant support and the final esthetics of an implant-borne prosthesis. At the 4-month follow-up visit, a biopsy was performed by a punch technique in the same sites of healing abutment connection. The tissue was elevated from the attached gingival. Clinically, the grafted tissues seemed to be attached to the bone surfaces. The histologic findings revealed dense grafted tissues, providing long-term stability to the area. No ligament or bone, characteristic for periodontal regeneration, were observed. The presence of thick attached keratinized tissue around implants may constitute a protective factor against marginal inflammation or trauma.

  7. Comparative clinical evaluation of laterally positioned pedicle graft and subepithelial connective tissue graft in the treatment of Miller's Class I and II gingival recession: A 6 months study

    PubMed Central

    Dulani, Kirti Satish; Bhavsar, Neeta Vijay; Trivedi, Sakshee Rahul; Trivedi, Rahul Anil

    2015-01-01

    Aim: The purpose of the study was to compare clinical outcomes of laterally positioned pedicle graft (LPPG) and subepithelial connective tissue graft (SCTG) for treatment of Miller's Class I and II gingival recession defects, at the end of 6 months. Materials and Methods: Sixty Miller's Class I or II gingival recession defects (≥3 mm) (n = 30 each) on the labial aspect of anterior teeth were treated by either of the above techniques. Clinical parameters including recession depth (RD), width of keratinized gingiva (WKG), percentage of root coverage (%RC), and complete RC were recorded at baseline and 6 months postoperatively. Data were recorded and statistical analysis was done for both intergroup and intragroup. Statistical Analysis Used: Paired t-test intragroup and Student's t-test intergroup. Results: In LPPG, RD decreased from 4.9 ± 0.99 mm to 1.1 ± 0.3 mm and WKG increased from 0.7 ± 0.87 to 4.5 ± 0.86 mm at 6 months, while in SCTG, RD decreased from 4.67 ± 1.12 mm to 0.46 ± 0.68 mm and WKG increased from 1.1 ± 0.99 to 5.33 ± 0.72 mm at 6 months postoperatively. The values of the soft tissue coverage remained stable for 6 months. Conclusions: Highly significant and effective soft tissue coverage was obtained by both techniques. LPPG resulted in effective soft tissue coverage for isolated deep narrow defects while SCTG in isolated and multiple, deep narrow and wide defects. PMID:26941517

  8. Development and function of pearl-sacs grown from regenerated mantle graft tissue in the black-lip pearl oyster, Pinctada margaritifera (Linnaeus, 1758).

    PubMed

    Kishore, Pranesh; Southgate, Paul C

    2015-08-01

    Current pearl grafting techniques were developed in the early 1900s and have changed little since. They involve the sacrifice of donor pearl oysters to provide graft tissue (saibo) that is implanted into host oysters. This study assessed the feasibility of using regenerated graft tissue for pearl production in the 'black-lip' pearl oyster, Pinctada margaritifera. Twelve days after grafting with regenerated graft tissue, there was complete encapsulation of the nucleus by the fully developed pearl-sac and the first layer of organic matrix had been secreted. Sixteen days after grafting, the pearl-sac was completely integrated with host tissue. The epithelial cells in the pearl-sac continued to secrete the organic matrix layer but there were no signs of nacre deposition at this stage. However, after three months of culture, nuclei in oysters grafted with regenerated mantle tissue were completely covered with nacre. The average nacre thickness on pearls produced from regenerated (0.547 ± 0.01 mm, n = 8) and normal (0.532 ± 0.01 mm, n = 8) mantle tissue did not differ significantly (p > 0.05). Nacre secretion rates, over the 80 day period subsequent to pearl-sac formation were 6.84 ± 0.1 μm day(-1) and 6.66 ± 0.1 μm day(-1) for oysters grafted with regenerated and normal mantle tissue, respectively. These means were not significantly different (p = 0.258). Our results clearly show that regenerated mantle tissue can function successfully as saibo for pearl production in P. margaritifera. This finding could provide significant benefits to pearl farmers and a basis for further development of current pearl grafting practices. PMID:25982400

  9. Surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft

    PubMed Central

    Bellver-Fernández, Ricardo; Martínez-Rodriguez, Ana-María; Gioia-Palavecino, Claudio; Caffesse, Raul-Guillermo

    2016-01-01

    Background A coronally advanced flap with subepithelial connective tissue graft is the gold standard surgical treatment of gingival recessions, since it offers a higher probability of achieving complete root coverage compared with other techniques. However, optimum short- and middle-term clinical results have also been obtained with coronally advanced flaps alone. The aim of the present study was to evaluate the results obtained by the surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft. Material and Methods The reduction of recession height was assessed, together with the gain in gingival attachment apical to the recession, and total reduction of recession, in a comparative study of two techniques. Twenty-two gingival recessions were operated upon: 13 in the control group (coronally advanced flap) and 9 in the test group (coronally advanced flap associated to subepithelial connective tissue graft). Results After 18 months, the mean reduction of recession height was 2.2 ± 0.8 mm in the control group and 2.3 ± 0.7 mm in the test group, with a mean gain in gingival attachment of 1.3 ± 0.9 mm and 2.3 ± 1.3 mm, respectively. In percentage terms, the mean reduction of recession height was 84.6 ± 19.6% in the control group and 81.7 ± 17.8% in the test group, with a mean gain in gingival attachment of 20.5 ± 37.4% and 184.4 ± 135.5%, respectively. Conclusions Significant reduction of gingival recession was achieved with both techniques, though the mean gain in gingival attachment (in mm and as a %) was greater in test group. Key words:Gingival recession, coronally advanced flap, subepthelial connective tissue graft. PMID:26595836

  10. Bone Marrow Aspiration Concentrate and Platelet Rich Plasma for Osteochondral Repair in a Porcine Osteochondral Defect Model

    PubMed Central

    Betsch, Marcel; Schneppendahl, Johannes; Thuns, Simon; Herten, Monika; Sager, Martin; Jungbluth, Pascal; Hakimi, Mohssen; Wild, Michael

    2013-01-01

    Background Bone marrow aspiration concentrate (BMAC) may possess a high potency for cartilage and osseous defect healing because it contains stem cells and multiple growth factors. Alternatively, platelet rich plasma (PRP), which contains a cocktail of multiple growth factors released from enriched activated thrombocytes may potentially stimulate the mesenchymal stem cells (MSCs) in bone marrow to proliferate and differentiate. Methods A critical size osteochondral defect (10×6 mm) in both medial femoral condyles was created in 14 Goettinger mini-pigs. All animals were randomized into the following four groups: biphasic scaffold alone (TRUFIT BGS, Smith & Nephew, USA), scaffold with PRP, scaffold with BMAC and scaffold in combination with BMAC and PRP. After 26 weeks all animals were euthanized and histological slides were cut, stained and evaluated using a histological score and immunohistochemistry. Results The thrombocyte number was significantly increased (p = 0.049) in PRP compared to whole blood. In addition the concentration of the measured growth factors in PRP such as BMP-2, BMP-7, VEGF, TGF-β1 and PDGF were significantly increased when compared to whole blood (p<0.05). In the defects of the therapy groups areas of chondrogenic tissue were present, which stained blue with toluidine blue and positively for collagen type II. Adding BMAC or PRP in a biphasic scaffold led to a significant improvement of the histological score compared to the control group, but the combination of BMAC and PRP did not further enhance the histological score. Conclusions The clinical application of BMAC or PRP in osteochondral defect healing is attractive because of their autologous origin and cost-effectiveness. Adding either PRP or BMAC to a biphasic scaffold led to a significantly better healing of osteochondral defects compared with the control group. However, the combination of both therapies did not further enhance healing. PMID:23951201

  11. TGF-β receptor 1 inhibition prevents stenosis of tissue-engineered vascular grafts by reducing host mononuclear phagocyte activation.

    PubMed

    Lee, Yong-Ung; de Dios Ruiz-Rosado, Juan; Mahler, Nathan; Best, Cameron A; Tara, Shuhei; Yi, Tai; Shoji, Toshihiro; Sugiura, Tadahisa; Lee, Avione Y; Robledo-Avila, Frank; Hibino, Narutoshi; Pober, Jordan S; Shinoka, Toshiharu; Partida-Sanchez, Santiago; Breuer, Christopher K

    2016-07-01

    Stenosis is a critical problem in the long-term efficacy of tissue-engineered vascular grafts (TEVGs). We previously showed that host monocyte infiltration and activation within the graft drives stenosis and that TGF-β receptor 1 (TGF-βR1) inhibition can prevent it, but the latter effect was attributed primarily to inhibition of mesenchymal cell expansion. In this study, we assessed the effects of TGF-βR1 inhibition on the host monocytes. Biodegradable TEVGs were implanted as inferior vena cava interposition conduits in 2 groups of C57BL/6 mice (n = 25/group): unseeded grafts and unseeded grafts with TGF-βR1 inhibitor systemic treatment for the first 2 wk. The TGF-βR1 inhibitor treatment effectively improved TEVG patency at 6 mo compared to the untreated control group (91.7 vs. 48%, P < 0.001), which is associated with a reduction in classic activation of mononuclear phagocytes. Consistent with these findings, the addition of rTGF-β to LPS/IFN-γ-stimulated monocytes enhanced secretion of inflammatory cytokines TNF-α, IL-12, and IL-6; this effect was blocked by TGF-βR1 inhibition (P < 0.0001). These findings suggest that the TGF-β signaling pathway contributes to TEVG stenosis by inducing classic activation of host monocytes. Furthermore, blocking monocyte activation by TGF-βR1 inhibition provides a viable strategy for preventing TEVG stenosis while maintaining neotissue formation.-Lee, Y.-U., de Dios Ruiz-Rosado, J., Mahler, N., Best, C. A., Tara, S., Yi, T., Shoji, T., Sugiura, T., Lee, A. Y., Robledo-Avila, F., Hibino, N., Pober, J. S., Shinoka, T., Partida-Sanchez, S., Breuer, C. K. TGF-β receptor 1 inhibition prevents stenosis of tissue-engineered vascular grafts by reducing host mononuclear phagocyte activation. PMID:27059717

  12. Release properties and functional integration of noradrenergic-rich tissue grafted to the denervated spinal cord of the adult rat.

    PubMed

    Leanza, G; Cataudella, T; Dimauro, R; Monaco, S; Stanzani, S

    1999-05-01

    Noradrenaline- (NA-) containing grafts of central (embryonic locus coeruleus, LC) or peripheral (juvenile adrenal medullary, AM, autologous superior cervical ganglionic, SCG) tissue were implanted unilaterally into rat lumbar spinal cord previously depleted of its NA content by 6-hydroxydopamine (6-OHDA) intraventricularly. A microdialysis probe was implanted in the spinal cord 3-4 months after transplantation, and extracellular levels of noradrenaline were monitored in freely moving animals during basal conditions and following administration of pharmacological or behavioural stimuli. Age-matched normal and lesioned animals both served as controls. Morphometric analyses were carried out on horizontal spinal sections processed for dopamine-beta-hydroxylase (DBH) immunocitochemistry, in order to assess lesion- or graft-induced changes in the density of spinal noradrenergic innervation, relative to the normal patterns. In lesioned animals, the entire spinal cord was virtually devoid of DBH-positive fibers, resulting in a dramatic 88% reduction in baseline NA, compared with that in controls, which did not change in response to the various stimuli. LC and SCG grafts reinstated approximately 80% and 50% of normal innervation density, respectively, but they differed strikingly in their release ability. Thus, LC grafts restored baseline NA levels up to 60% of those in controls, and responded with significantly increased NA release to KCl-induced depolarization, neuronal uptake blockade and handling. In contrast, very low NA levels and only poor and inconsistent responses to the various stimuli were observed in the SCG-grafted animals. In AM-grafted animals, spinal extracellular NA levels were restored up to 45% of those in controls, probably as a result of nonsynaptic, endocrine-like release, as grafted AM cells retained the chromaffine phenotype, showed no detectable fibre outgrowth and did not respond to any of the pharmacological or behavioural challenges. Thus, both a

  13. Design of a multiphase osteochondral scaffold. I. Control of chemical composition.

    PubMed

    Lynn, Andrew K; Best, Serena M; Cameron, Ruth E; Harley, Brendan A; Yannas, Ioannis V; Gibson, Lorna J; Bonfield, William

    2010-03-01

    This is the first in a series of articles that describe the design and development of a family of osteochondral scaffolds based on collagen-glycosaminoglycan (collagen-GAG) and calcium phosphate technologies, engineered for the regenerative repair of defects in articular cartilage. The osteochondral scaffolds consist of two layers: a mineralized type I collagen-GAG scaffold designed to regenerate the underlying subchondral bone and a nonmineralized type II collagen-GAG scaffold designed to regenerate cartilage. The subsequent articles in this series describe the fabrication and properties of a mineralized scaffold as well as a two-layer (one mineralized, the other not) osteochondral scaffold for regeneration of the underlying bone and cartilage, respectively. This article describes a technology through which the chemical composition-particularly the calcium phosphate mass fraction-of triple coprecipitated nanocomposites of collagen, glycosaminoglycan, and calcium phosphate can be accurately and reproducibly varied without the need for titrants or other additives. Here, we describe how the mineral:organic ratio can be altered over a range that includes that for articular cartilage (0 wt % mineral) and for bone (75 wt % mineral). This technology achieves the objective of mimicking the composition of two main tissue types found in articular joints, with particular emphasis on the osseous compartment of an osteochondral scaffold. Exclusion of titrants avoids the formation of potentially harmful contaminant phases during freeze-drying steps crucial for scaffold fabrication, ensuring that the potential for binding growth factors and drugs is maintained.

  14. A Bi-Layered Elastomeric Scaffold for Tissue Engineering of Small-Diameter Vascular Grafts

    PubMed Central

    Soletti, Lorenzo; Hong, Yi; Guan, Jianjun; Stankus, John J.; El-Kurdi, Mohammed S.; Wagner, William R.; Vorp, David A.

    2011-01-01

    A major barrier in the development of a clinically-useful small-diameter tissue engineered vascular graft (TEVG) is the scaffold component. Scaffold requirements include matching the mechanical and structural properties with those of native vessels and optimizing the microenvironment to foster cell integration, adhesion, and growth. We have developed a small-diameter, bi-layered, biodegradable, elastomeric scaffold based on a synthetic, biodegradable elastomer. The scaffold incorporates a highly porous inner layer, allowing cell integration and growth, and an external, fibrous reinforcing layer deposited by electrospinning. Scaffold morphology and mechanical properties were assessed, quantified, and compared to those of native vessels. Scaffolds were then seeded with adult stem cells via a rotational vacuum seeding device to obtain a TEVG, cultured in dynamic conditions for 7 days, and evaluated for cellularity. The scaffold showed a firm integration of the two polymeric layers with no delaminations. Mechanical properties were physiologically-consistent showing anisotropy, elastic modulus (1.4±0.4 MPa), and ultimate tensile stress (8.3±1.7 MPa) comparable with native vessels. Compliance and suture retention force were 4.6±0.5×10−4 mmHg−1 and 3.4±0.3 N, respectively. Seeding resulted in a rapid, uniform, bulk integration of cells, with a seeding efficiency of 92±1%. The scaffolds maintained a high level of cellular density throughout dynamic culture. This approach, combining artery-like mechanical properties and a rapid and efficient cellularization, might contribute to the future clinical translation of TEVGs. PMID:19540370

  15. In vitro characterization of design and compressive properties of 3D-biofabricated/decellularized hybrid grafts for tracheal tissue engineering.

    PubMed

    Johnson, Christopher; Sheshadri, Priyanka; Ketchum, Jessica M; Narayanan, Lokesh K; Weinberger, Paul M; Shirwaiker, Rohan A

    2016-06-01

    Infection or damage to the trachea, a thin walled and cartilage reinforced conduit that connects the pharynx and larynx to the lungs, leads to serious respiratory medical conditions which can often prove fatal. Current clinical strategies for complex tracheal reconstruction are of limited availability and efficacy, but tissue engineering and regenerative medicine approaches may provide viable alternatives. In this study, we have developed a new "hybrid graft" approach that utilizes decellularized tracheal tissue along with a resorbable polymer scaffold, and holds promise for potential clinical applications. First, we evaluated the effect of our decellularization process on the compression properties of porcine tracheal segments, and noted approximately 63% decrease in resistance to compression following decellularization. Next we developed four C-shape scaffold designs by varying the base geometry and thickness, and fabricated polycaprolactone scaffolds using a combination of 3D-Bioplotting and thermally-assisted forming. All scaffolds designs were evaluated in vitro under three different environmental testing conditions to determine the design that offered the best resistance to compression. These were further studied to determine the effect of gamma radiation sterilization and cyclic compression loading. Finally, hybrid grafts were developed by securing these optimal design scaffolds to decellularized tracheal segments and evaluated in vitro under physiological testing conditions. Results show that the resistance to compression offered by the hybrid grafts created using gamma radiation sterilized scaffolds was comparable to that of fresh tracheal segments. Given that current clinical attempts at tracheal transplantation using decellularized tissue have been fraught with luminal collapse and complications, our data support the possibility that future embodiments using a hybrid graft approach may reduce the need for intraluminal stenting in tracheal transplant

  16. Free bone graft reconstruction of irradiated facial tissue: Experimental effects of basic fibroblast growth factor stimulation

    SciTech Connect

    Eppley, B.L.; Connolly, D.T.; Winkelmann, T.; Sadove, A.M.; Heuvelman, D.; Feder, J. )

    1991-07-01

    A study was undertaken to evaluate the potential utility of basic fibroblast growth factor in the induction of angiogenesis and osseous healing in bone previously exposed to high doses of irradiation. Thirty New Zealand rabbits were evaluated by introducing basic fibroblast growth factor into irradiated mandibular resection sites either prior to or simultaneous with reconstruction by corticocancellous autografts harvested from the ilium. The fate of the free bone grafts was then evaluated at 90 days postoperatively by microangiographic, histologic, and fluorochrome bone-labeling techniques. Sequestration, necrosis, and failure to heal to recipient osseous margins was observed both clinically and histologically in all nontreated irradiated graft sites as well as those receiving simultaneous angiogenic stimulation at the time of graft placement. No fluorescent activity was seen in these graft groups. In the recipient sites pretreated with basic fibroblast growth factor prior to placement of the graft, healing and reestablishment of mandibular contour occurred in nearly 50 percent of the animals. Active bone formation was evident at cortical margins adjacent to the recipient sites but was absent in the more central cancellous regions of the grafts.

  17. Comparison of a closed system to a standard open technique for preparing tissue-engineered vascular grafts.

    PubMed

    Kurobe, Hirotsugu; Maxfield, Mark W; Naito, Yuji; Cleary, Muriel; Stacy, Mitchel R; Solomon, Daniel; Rocco, Kevin A; Tara, Shuhei; Lee, Avione Y; Sinusas, Albert J; Snyder, Edward L; Shinoka, Toshiharu; Breuer, Christopher K

    2015-01-01

    We developed a prototype for a closed apparatus for assembling tissue-engineered vascular grafts (TEVGs) with the goal of creating a simple operator-independent method for making TEVGs to optimize safety and enable widespread application of this technology. The TEVG is made by seeding autologous bone marrow-derived mononuclear cells onto a biodegradable tubular scaffold and is the first man-made vascular graft to be successfully used in humans. A critical barrier, which has prevented the widespread clinical adoption of the TEVG, is that cell isolation, scaffold seeding, and incubation are performed using an open method. To reduce the risk of contamination, the TEVG is assembled in a clean room. Clean rooms are expensive to build, complex to operate, and are not available in most hospitals. In this investigation, we used an ovine model to compare the safety and efficacy of TEVGs created using either a standard density centrifugation-based open method or the new filter-based closed system. We demonstrated no graft-related complications and maintenance of growth capacity in TEVGs created using the closed apparatus. In addition, the use of the closed system reduced the amount of time needed to assemble the TEVG by ∼ 50%. Adaptation of similar methodologies may facilitate the safe translation and the widespread use of other tissue engineering technologies. PMID:24866863

  18. Bilateral osteochondritis dissecans of the elbow in a female pitcher.

    PubMed

    Williamson, L R; Albright, J P

    1996-11-01

    We report a case of a 17-year-old female pitcher with bilateral elbow osteochondritis dissecans. Osteochondritis of the elbow is a well-known disorder affecting pitchers and other individuals who sustain repetitive microtrauma to the elbow. Elbow osteochondritis has been described infrequently in female athletes. The incidence and reporting patterns of this disease are likely to increase as more female athletes participate in organized sports.

  19. Experimental study on the construction of small three-dimensional tissue engineered grafts of electrospun poly-ε-caprolactone.

    PubMed

    Zhu, Guang-Chang; Gu, Yong-Quan; Geng, Xue; Feng, Zeng-Guo; Zhang, Shu-Wen; Ye, Lin; Wang, Zhong-Gao

    2015-02-01

    Studies on three-dimensional tissue engineered graft (3DTEG) have attracted great interest among researchers as they present a means to meet the pressing clinical demand for tissue engineering scaffolds. To explore the feasibility of 3DTEG, high porosity poly-ε-caprolactone (PCL) was obtained via the co-electrospinning of polyethylene glycol and PCL, and used to construct small-diameter poly-ε-caprolactone-lysine (PCL-LYS-H) scaffolds, whereby heparin was anchored to the scaffold surface by lysine groups. A variety of small-diameter 3DTEG models were constructed with different PCL layers and the mechanical properties of the resulting constructs were evaluated in order to select the best model for 3DTEGs. Bone marrow mononuclear cells were induced and differentiated to endothelial cells (ECs) and smooth muscle cells (SMCs). A 3DTEG (labeled '10-4%') was successfully produced by the dynamic co-culture of ECs on the PCL-LYS-H scaffolds and SMCs on PCL. The fluorescently labeled cells on the 3DTEG were subsequently observed by laser confocal microscopy, which showed that the ECs and SMCs were embedded in the 3DTEG. Nitric oxide and endothelial nitric oxide synthase assays showed that the ECs behaved normally in the 3DTEG. This study consequently provides a new thread to produce small-diameter tissue engineered grafts, with excellent mechanical properties, that are perfusable to vasculature and functional cells. PMID:25665848

  20. Free flap transplantation combined with skin grafting and vacuum sealing drainage for repair of circumferential or sub-circumferential soft-tissue wounds of the lower leg

    PubMed Central

    Li, Run-guang; Ren, Gao-hong; Tan, Xiong-jin; Yu, Bin; Hu, Ji-jie

    2013-01-01

    Background This study is aimed at evaluating the operation techniques and clinical significance of free flap transplantation combined with skin grafting and vacuum sealing drainage (VSD) in repairing severe traumatic extensive circumferential or semi-circumferential soft-tissue defects of the lower leg. Material/Methods Thirty patients with severe lower leg injuries were treated by free flap transplantation combined with skin grafting and VSD from January 2008 to June 2011. The size of the wounds ranged from 23×8 cm to 44×28 cm and all affected more 70% of the low leg circumferential area. Wounds were complicated by exposure, necrosis, or infection of deep tissues. The wounds were first debrided and covered by VSD. When the condition of the wound had improved (5 to 7 days later), free flaps were harvested to reconstruct damaged tissue and skin grafts and VSD was used to cover granulation tissues around the transplanted flap. Results Granulation tissues developed and the area requiring flap cover decreased in all 30 patients after debridement and VSD. In 28 of 30 cases, the transplanted flaps grew well without complication. Peripheral necrosis was observed in only 2 cases, which required a second debridement and skin graft. Ten wound areas covered by grafts were left with scattered peripheral wounds, which healed with the help of 1 more skin graft or dressing change. Morphological appearance and functional recovery were satisfactory in all 30 cases. Conclusions Initial debridement and the temporary VSD cover followed after several days by free flap transplantation combined with skin grafting and VSD protection is a reliable treatment regimen for traumatic large circumferential or sub-circumferential soft tissue wounds of the lower leg with deep tissue exposure. PMID:23807087

  1. Chemical hydrogels based on a hyaluronic acid-graft-α-elastin derivative as potential scaffolds for tissue engineering.

    PubMed

    Palumbo, Fabio Salvatore; Pitarresi, Giovanna; Fiorica, Calogero; Rigogliuso, Salvatrice; Ghersi, Giulio; Giammona, Gaetano

    2013-07-01

    In this work hyaluronic acid (HA) functionalized with ethylenediamine (EDA) has been employed to graft α-elastin. In particular a HA-EDA derivative bearing 50 mol% of pendant amino groups has been successfully employed to produce the copolymer HA-EDA-g-α-elastin containing 32% w/w of protein. After grafting with α-elastin, remaining free amino groups reacted with ethylene glycol diglycidyl ether (EGDGE) for producing chemical hydrogels, proposed as scaffolds for tissue engineering. Swelling degree, resistance to chemical and enzymatic hydrolysis, as well as preliminary biological properties of HA-EDA-g-α-elastin/EGDGE scaffold have been evaluated and compared with a HA-EDA/EGDGE scaffold. The presence of α-elastin grafted to HA-EDA improves attachment, viability and proliferation of primary rat dermal fibroblasts and human umbilical artery smooth muscle cells. Biological performance of HA-EDA-g-α-elastin/EGDGE scaffold resulted comparable to that of a commercial collagen type I sponge (Antema®), chosen as a positive control.

  2. Bimaxillary protrusion with an atrophic alveolar defect: orthodontics, autogenous chin-block graft, soft tissue augmentation, and an implant.

    PubMed

    Chiu, Grace S C; Chang, Chris H N; Roberts, W Eugene

    2015-01-01

    Bimaxillary protrusion in a 28-year-old woman was complicated by multiple missing, restoratively compromised, or hopeless teeth. The maxillary right central incisor had a history of avulsion and replantation that subsequently evolved into generalized external root resorption with Class III mobility and severe loss of the supporting periodontium. This complex malocclusion had a discrepancy index of 21, and 8 additional points were scored for the atrophic dental implant site (maxillary right central incisor). The comprehensive treatment plan included extraction of 4 teeth (both maxillary first premolars, the maxillary right central incisor, and the mandibular right first molar), orthodontic closure of all spaces except for the future implant site (maxillary right central incisor), augmentation of the alveolar defect with an autogenous chin-block graft, enhancement of the gingival biotype with a connective tissue graft, and an implant-supported prosthesis. Orthodontists must understand the limitations of bone grafts. Augmented alveolar defects are slow to completely turn over to living bone, so they are usually good sites for implants but respond poorly to orthodontic space closure. However, postsurgical orthodontic treatment is often indicated to optimally finish the esthetic zone before placing the final prosthesis. The latter was effectively performed for this patient, resulting in a total treatment time of about 36 months for comprehensive interdisciplinary care. An excellent functional and esthetic result was achieved. PMID:25533077

  3. A functional chitosan membrane with grafted epigallocatechin-3-gallate and lovastatin enhances periodontal tissue regeneration in dogs.

    PubMed

    Lee, Bor-Shiunn; Lee, Chien-Chen; Lin, Hung-Pin; Shih, Wei-An; Hsieh, Wan-Ling; Lai, Chern-Hsiung; Takeuchi, Yasuo; Chen, Yi-Wen

    2016-10-20

    Currently used guided tissue regeneration (GTR) membranes are mainly used as a barrier to prevent epithelial cells growth into defects before new bone formation. The aim of this study was to develop a tri-layer functional chitosan (CS) membrane with epigallocatechin-3-gallate (EGCG) grafted on the outer layer for bactericidal activity, and lovastatin was included in the middle layer for controlled release. Successful EGCG grafting was demonstrated using Fourier transform infrared spectroscopy and EGCG grafting significantly enhanced adhesion and proliferation of human gingival fibroblasts. The release duration of lovastatin reached 21days. CS-Lovastatin1 produced the highest alkaline phosphatase activity and EGCG14-CS exhibited the best bactericidal activity against periodontopathic bacteria. Finally, the EGCG14-CS-Lovastatin1 membrane showed a higher percentage of bone regeneration than BioMend(®) and control groups in one-walled defects of beagle dogs. These results suggest that the EGCG14-CS-Lovastatin1 membrane has the potential to be used as a novel GTR membrane. PMID:27474626

  4. Mechanical evaluation of a soft tissue interference screw in free tendon anterior cruciate ligament graft fixation.

    PubMed

    Nagarkatti, D G; McKeon, B P; Donahue, B S; Fulkerson, J P

    2001-01-01

    In this study of bioabsorbable screw fixation of free tendon grafts used in anterior cruciate ligament reconstruction, we performed load-to-failure and cyclic loading of tendon fixation in porcine bone. Bone density measurements from dual photon absorptometry scans were obtained to correlate bone density with fixation failure. The average density of porcine bone (1.42 g/cm2) was similar to that of young human bone (1.30 g/cm2) and significantly higher than that of elderly human cadaveric bone specimens (0.30 g/cm2). Cyclic loading was performed on free tendon grafts fixed with a bioabsorbable screw alone and on grafts fixed with a bioabsorbable screw and an anchor (polylactic acid ball or cortical bone disk). Stiffness of fixation increased substantially with the addition of a cortical bone disk anchor or polylactic acid ball compared with the interference screw alone. Tensile fixation strength of central quadriceps free tendon and hamstring tendon grafts were significantly superior in porcine bone of density similar to young human bone than in elderly human cadaveric bone. The bioabsorbable interference screw yielded loads at failure comparable with traditional bone-tendon-bone and hamstring tendon fixation when controlled for bone density. The addition of a cortical bone disk anchor provided the most optimal fixation of free tendon with the bioabsorbable screw and reduced slippage with cyclic loading to a very low level.

  5. Functionalized nanofibers as drug-delivery systems for osteochondral regeneration.

    PubMed

    Amler, Evžen; Filová, Eva; Buzgo, Matej; Prosecká, Eva; Rampichová, Michala; Nečas, Alois; Nooeaid, Patcharakamon; Boccaccini, Aldo R

    2014-05-01

    A wide range of drug-delivery systems are currently attracting the attention of researchers. Nanofibers are very interesting carriers for drug delivery. This is because nanofibers are versatile, flexible, nanobiomimetic and similar to extracellular matrix components, possible to be functionalized both on their surface as well as in their core, and also because they can be produced easily and cost effectively. There have been increasing attempts to use nanofibers in the construction of a range of tissues, including cartilage and bone. Nanofibers have also been favorably engaged as a drug-delivery system in cell-free scaffolds. This short overview is devoted to current applications and to further perspectives of nanofibers as drug-delivery devices in the field of cartilage and bone regeneration, and also in osteochondral reconstruction. PMID:24978465

  6. Osteochondral defects in the ankle: why painful?

    PubMed Central

    Reilingh, Mikel L.; Zengerink, Maartje; van Bergen, Christiaan J. A.

    2010-01-01

    Osteochondral defects of the ankle can either heal and remain asymptomatic or progress to deep ankle pain on weight bearing and formation of subchondral bone cysts. The development of a symptomatic OD depends on various factors, including the damage and insufficient repair of the subchondral bone plate. The ankle joint has a high congruency. During loading, compressed cartilage forces its water into the microfractured subchondral bone, leading to a localized high increased flow and pressure of fluid in the subchondral bone. This will result in local osteolysis and can explain the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion, but is most probably caused by repetitive high fluid pressure during walking, which results in stimulation of the highly innervated subchondral bone underneath the cartilage defect. Understanding the natural history of osteochondral defects could lead to the development of strategies for preventing progressive joint damage. PMID:20151110

  7. Photodynamic damage to cartilage and synovial tissue grafted on a chick's chorioallantoic membrane

    NASA Astrophysics Data System (ADS)

    Fisher, M.; Nahir, A. M.; Kimel, Sol

    1997-09-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease of the synovial joints causing pain deformities and disability. The highly vascular inflamed synovium has aggressive and destructive characteristics, it invades, erodes and gradually destroys cartilage and underlying bone. Photodynamic therapy (PDT) was performed using the chick chorioallantoic membrane (CAM) model to investigate the vitality of synovium and cartilage implanted on the CAM. Synovium, obtained from human patients, was grafted onto the CAM; gross microscopy and histology proved its vitality 7 days post grafting. Cartilage obtained from rabbit knee joint was also maintained on the CAM for 7 days. Its vitality was demonstrated by histology and by measuring metabolic and enzymatic activity of cartilage cells (chondrocytes) as well as the collagen and proteoglycans content. Selective PDT was performed using aluminum phthalocyanine tetrasulfonate (AlPcS4), a hydrophilic compound, soluble in biological solutions, as a photosensitizer. After irradiation with a diode laser (lambda equals 670 nm, 10 mW) damage was observed in vascularized synovium grafts, whereas avascular cartilage remained intact.

  8. Real-time immune cell interactions in target tissue during autoimmune-induced damage and graft tolerance.

    PubMed

    Miska, Jason; Abdulreda, Midhat H; Devarajan, Priyadharshini; Lui, Jen Bon; Suzuki, Jun; Pileggi, Antonello; Berggren, Per-Olof; Chen, Zhibin

    2014-03-10

    Real-time imaging studies are reshaping immunological paradigms, but a visual framework is lacking for self-antigen-specific T cells at the effector phase in target tissues. To address this issue, we conducted intravital, longitudinal imaging analyses of cellular behavior in nonlymphoid target tissues to illustrate some key aspects of T cell biology. We used mouse models of T cell-mediated damage and protection of pancreatic islet grafts. Both CD4(+) and CD8(+) effector T (Teff) lymphocytes directly engaged target cells. Strikingly, juxtaposed β cells lacking specific antigens were not subject to bystander destruction but grew substantially in days, likely by replication. In target tissue, Foxp3(+) regulatory T (Treg) cells persistently contacted Teff cells with or without involvement of CD11c(+) dendritic cells, an observation conciliating with the in vitro "trademark" of Treg function, contact-dependent suppression. This study illustrates tolerance induction by contact-based immune cell interaction in target tissues and highlights potentials of tissue regeneration under antigenic incognito in inflammatory settings.

  9. Microsphere-based gradient implants for osteochondral regeneration: a long-term study in sheep

    PubMed Central

    Mohan, Neethu; Gupta, Vineet; Sridharan, Banu Priya; Mellott, Adam J; Easley, Jeremiah T; Palmer, Ross H; Galbraith, Richard A; Key, Vincent H; Berkland, Cory J; Detamore, Michael S

    2015-01-01

    Background: The microfracture technique for cartilage repair has limited ability to regenerate hyaline cartilage. Aim: The current study made a direct comparison between microfracture and an osteochondral approach with microsphere-based gradient plugs. Materials & methods: The PLGA-based scaffolds had opposing gradients of chondroitin sulfate and β-tricalcium phosphate. A 1-year repair study in sheep was conducted. Results: The repair tissues in the microfracture were mostly fibrous and had scattered fissures with degenerative changes. Cartilage regenerated with the gradient plugs had equal or superior mechanical properties; had lacunated cells and stable matrix as in hyaline cartilage. Conclusion: This first report of gradient scaffolds in a long-term, large animal, osteochondral defect demonstrated potential for equal or better cartilage repair than microfracture. PMID:26418471

  10. Arthroscopic Anatomic Humeral Head Reconstruction With Osteochondral Allograft Transplantation for Large Hill-Sachs Lesions

    PubMed Central

    Snir, Nimrod; Wolfson, Theodore S.; Hamula, Mathew J.; Gyftopoulos, Soterios; Meislin, Robert J.

    2013-01-01

    Anatomic reconstruction of the humeral head with osteochondral allograft has been reported as a solution for large Hill-Sachs lesions with or without glenoid bone loss. However, to date, varying techniques have been used. This technical note describes an arthroscopic reconstruction technique using fresh-frozen, side- and size-matched osteochondral humeral head allograft. Allograft plugs are press fit into the defect without internal fixation and seated flush with the surrounding articular surface. This technique restores the native articular contour of the humeral head without compromising shoulder range of motion. Potential benefits of this all-arthroscopic approach include minimal trauma to the soft tissue and articular surface without the need for hardware or staged reoperation. PMID:24266001

  11. Tuning Cell Differentiation into a 3D Scaffold Presenting a Pore Shape Gradient for Osteochondral Regeneration.

    PubMed

    Di Luca, Andrea; Lorenzo-Moldero, Ivan; Mota, Carlos; Lepedda, Antonio; Auhl, Dietmar; Van Blitterswijk, Clemens; Moroni, Lorenzo

    2016-07-01

    Osteochondral regeneration remains nowadays a major problem since the outcome of current techniques is not satisfactory in terms of functional tissue formation and development. A possible solution is the combination of human mesenchymal stem cells (hMSCs) with additive manufacturing technologies to fabricate scaffolds with instructive properties. In this study, the differentiation of hMSCs within a scaffold presenting a gradient in pore shape is presented. The variation in pore shape is determined by varying the angle formed by the fibers of two consequent layers. The fiber deposition patterns are 0-90, which generate squared pores, 0-45, 0-30, and 0-15, that generate rhomboidal pores with an increasing major axis as the deposition angle decreases. Within the gradient construct, squared pores support a better chondrogenic differentiation whereas cells residing in the rhomboidal pores display a better osteogenic differentiation. When cultured under osteochondral conditions the trend in both osteogenic and chondrogenic markers is maintained. Engineering the pore shape, thus creating axial gradients in structural properties, seems to be an instructive strategy to fabricate functional 3D scaffolds that are able to influence hMSCs differentiation for osteochondral tissue regeneration. PMID:27109461

  12. Development and characterisation of a decellularised bovine osteochondral biomaterial for cartilage repair.

    PubMed

    Fermor, Hazel L; Russell, Serena L; Williams, Sophie; Fisher, John; Ingham, Eileen

    2015-05-01

    It is proposed that an acellular natural osteochondral scaffold will provide a successful repair material for the early intervention treatment of cartilage lesions, to prevent or slow the progression of cartilage deterioration to osteoarthritis. Here, we investigated the efficacy of methods for the decellularisation of bovine osteochondral plugs. The plugs were subject to four freeze/thaw cycles followed by two cycles of washes in hypotonic solution and low concentration (0.1% w/v) sodium dodecyl sulphate with protease inhibitors. Plugs were treated with nuclease (DNase and RNase) treatment followed by sterilization in peracetic acid. Full tissue decellularisation was achieved as confirmed by histological analysis and DNA quantification, however the resultant acellular matrix had reduced glycosaminoglycan content which led to an increased percent deformation of cartilage. Furthermore, the acellular scaffold was not reproducibly biocompatible. Additional terminal washes were included in the process to improve biocompatibility, however, this led to visible structural damage to the cartilage. This damage was found to be minimised by reducing the cut edge to cartilage area ratio through decellularisation of larger cuts of osteochondral tissue. PMID:25893393

  13. A bioreactor test system to mimic the biological and mechanical environment of oral soft tissues and to evaluate substitutes for connective tissue grafts.

    PubMed

    Mathes, Stephanie H; Wohlwend, Lorenz; Uebersax, Lorenz; von Mentlen, Roger; Thoma, Daniel S; Jung, Ronald E; Görlach, Christoph; Graf-Hausner, Ursula

    2010-12-15

    Gingival cells of the oral connective tissue are exposed to complex mechanical forces during mastication, speech, tooth movement and orthodontic treatments. Especially during wound healing following surgical procedures, internal and external forces may occur, creating pressure upon the newly formed tissue. This clinical situation has to be considered when developing biomaterials to augment soft tissue in the oral cavity. In order to pre-evaluate a collagen sponge intended to serve as a substitute for autogenous connective tissue grafts (CTGs), a dynamic bioreactor system was developed. Pressure and shear forces can be applied in this bioreactor in addition to a constant medium perfusion to cell-material constructs. Three-dimensional volume changes and stiffness of the matrices were analyzed. In addition, cell responses such as cell vitality and extracellular matrix (ECM) production were investigated. The number of metabolic active cells constantly increased under fully dynamic culture conditions. The sponges remained elastic even after mechanical forces were applied for 14 days. Analysis of collagen type I and fibronectin revealed a statistically significant accumulation of these ECM molecules (P < 0.05-0.001) when compared to static cultures. An increased expression of tenascin-c, indicating tissue remodeling processes, was observed under dynamic conditions only. The results indicate that the tested in vitro cell culture system was able to mimic both the biological and mechanical environments of the clinical situation in a healing wound.

  14. Matching osteochondritis dissecans lesions in identical twin brothers.

    PubMed

    Richie, Lucas B; Sytsma, Mark J

    2013-09-01

    Osteochondritis dissecans is a disorder of unknown etiology that can result in fragmentation of osteochondral surfaces, most commonly of the knee, shoulder, elbow, and ankle. This may lead to sequelae of pain and an inability to participate in desired activities. Multiple theories exist as to the true cause of the disorder, but none have been fully proven. One such proposed etiology is genetic causation. Familial cases of osteochondritis dissecans are rare, yet these cases offer support to growing evidence that may support a genetic link. This article describes osteochondritis dissecans lesions of the femoral trochlea in monozygotic (identical) twins. Both twins presented with similar symptoms 1 year apart. Neither twin had any clear inciting trauma. Magnetic resonance imaging revealed osteochondral lesions in similar positions of the lateral trochlear of the same knee in both brothers. Osteochondral autograft transfer and tibial tubercle anteromedialization were performed on both patients. An identical postoperative protocol was followed, and recovery with full return to sport was comparable for the brothers. To the authors' knowledge, only 1 other case report exists of osteochondritis dissecans lesions in monozygotic twins. Although debate continues regarding the true etiology of this disorder, cases of identical twins presenting with a similar disease process are highly suggestive of a genetic component and may lead to early identification and treatment of these lesions. Continued research in the area of osteochondritis dissecans and its genetic basis is needed to completely understand this disorder. PMID:24025016

  15. Immediate placement and provisionalization of maxillary anterior single implant with guided bone regeneration, connective tissue graft, and coronally positioned flap procedures.

    PubMed

    Waki, Tomonori; Kan, Joseph Y K

    2016-01-01

    Immediate implant placement and provisionalization in the esthetic zone have been documented with success. The benefit of immediate implant placement and provisionalization is the preservation of papillary mucosa. However, in cases with osseous defects presenting on the facial bony plate, immediate implant placement procedures have resulted in facial gingival recession. Subepithelial connective tissue grafts for immediate implant placement and provisionalization procedures have been reported with a good esthetic outcome. Biotype conversion around implants with subepithelial connective tissue grafts have been advocated, and the resulting tissues appear to be more resistant to recession. The dimensions of peri-implant mucosa in a thick biotype were significantly greater than in a thin biotype. Connective tissue graft with coronally positioned flap procedures on natural teeth has also been documented with success. This article describes a technique combining immediate implant placement, provisionalization, guided bone regeneration (GBR), connective tissue graft, and a coronally positioned flap in order to achieve more stable peri-implant tissue in facial osseous defect situations.

  16. Immediate placement and provisionalization of maxillary anterior single implant with guided bone regeneration, connective tissue graft, and coronally positioned flap procedures.

    PubMed

    Waki, Tomonori; Kan, Joseph Y K

    2016-01-01

    Immediate implant placement and provisionalization in the esthetic zone have been documented with success. The benefit of immediate implant placement and provisionalization is the preservation of papillary mucosa. However, in cases with osseous defects presenting on the facial bony plate, immediate implant placement procedures have resulted in facial gingival recession. Subepithelial connective tissue grafts for immediate implant placement and provisionalization procedures have been reported with a good esthetic outcome. Biotype conversion around implants with subepithelial connective tissue grafts have been advocated, and the resulting tissues appear to be more resistant to recession. The dimensions of peri-implant mucosa in a thick biotype were significantly greater than in a thin biotype. Connective tissue graft with coronally positioned flap procedures on natural teeth has also been documented with success. This article describes a technique combining immediate implant placement, provisionalization, guided bone regeneration (GBR), connective tissue graft, and a coronally positioned flap in order to achieve more stable peri-implant tissue in facial osseous defect situations. PMID:27092345

  17. Dysplasia Epiphysealis Hemimelica Treated with Osteochondral Allograft: A Case Report

    PubMed Central

    Anthony, Chris A.; Wolf, Brian R.

    2015-01-01

    Background Dysplasia epiphysealis hemimelica (DEH), or Trevor's disease, is a developmental disorder of the pediatric skeleton characterized by asymmetric osteochondral overgrowth. Methods We present the case of a five year old boy with a two year history of right knee pain and evidence of DEH on imaging who underwent initial arthroscopic resection of his lesion with subsequent recurrence. The patient then underwent osteochondral allograft revision surgery and was asymptomatic at two year follow-up with a congruent joint surface. Results To our knowledge, this is the first reported case of a DEH lesion treated with osteochondral allograft and also the youngest reported case of osteochondral allograft placement in the literature. Conclusions Osteochondral allograft may be a viable option in DEH and other deformities of the pediatric knee. Level of Evidence Level V PMID:26361443

  18. The effects of early or late treatment of osteochondral defects on joint homoeostasis: an experimental study in rabbits.

    PubMed

    Ozsoy, Mehmet Hakan; Aydogdu, Semih; Taskiran, Dilek; Sezak, Murat; Hayran, Mutlu; Oztop, Fikri; Ozsoy, Arzu

    2009-06-01

    A 3.5 x 4 mm tubular osteochondral defect was created on the right medial femoral condyles of 51 adult rabbits. In the control group (CG), defects were left untreated. In the early-(ETG) and late-(LTG) treatment groups, defects were treated by an osteoperiosteal graft 1 and 12 weeks, respectively, after the index procedure. Synovial fluid (SF) samples were collected regularly and proteoglycan fragments (PF), total collagen (TC) and collagenase (MMP-1) levels were measured. Rabbits were killed at 4 (early period), 12 (intermediate period), or 24 (late period) weeks postoperatively. Histological examination indicated a more successful healing in both grafting groups than in the CG, but without any difference at any time period between the grafting groups. In the CG, PF, and TC levels in SF increased continuously until the late period, indicating an ongoing degenerative activity in the joints. In contrast, SF marker levels in both grafting groups indicated that normalization in joint metabolism could be achieved-at least partially-after treatment. However, PF levels in the SF showed that the treatment of defects in earlier stages might result in better outcomes since the negative effects were more prominent in chronic stages, presumably due to the more prolonged period of disturbed homeostasis. Thus, histological values and SF marker levels indicated that treatment of osteochondral defects at any time of the disease had a positive effect on healing when compared to no treatment. Early treatment might better assist the recovery of joint homeostasis than late treatment.

  19. Tissue Engineering of Ureteral Grafts: Preparation of Biocompatible Crosslinked Ureteral Scaffolds of Porcine Origin

    PubMed Central

    Koch, Holger; Hammer, Niels; Ossmann, Susann; Schierle, Katrin; Sack, Ulrich; Hofmann, Jörg; Wecks, Mike; Boldt, Andreas

    2015-01-01

    The surgical reconstruction of ureteric defects is often associated with post-operative complications and requires additional medical care. Decellularized ureters originating from porcine donors could represent an alternative therapy. Our aim was to investigate the possibility of manufacturing decellularized ureters, the characteristics of the extracellular matrix (ECM) and the biocompatibility of these grafts in vitro/in vivo after treatment with different crosslinking agents. To achieve these goals, native ureters were obtained from pigs and were decellularized. The success of decellularization and the ECM composition were characterized by (immuno)histological staining methods and a DNA-assay. In vitro: scaffolds were crosslinked either with carbodiimide (CDI), genipin (GP), glutaraldehyde, left chemically untreated or were lyophilized. Scaffolds in each group were reseeded with Caco2, LS48, 3T3 cells, or native rat smooth muscle cells (SMC). After 2 weeks, the number of ingrown cells was quantified. In vivo: crosslinked scaffolds were implanted subcutaneously into rats and the type of infiltrating cells were determined after 1, 9, and 30 days. After decellularization, scaffold morphology and composition of ECM were maintained, all cellular components were removed, DNA destroyed and strongly reduced. In vitro: GP and CDI scaffolds revealed a higher number of ingrown 3T3 and SMC cells as compared to untreated scaffolds. In vivo: at day 30, implants were predominantly infiltrated by fibroblasts and M2 anti-inflammatory macrophages. A maximum of MMP3 was observed in the CDI group at day 30. TIMP1 was below the detection limit. In this study, we demonstrated the potential of decellularization to create biocompatible porcine ureteric grafts, whereas a CDI-crosslink may facilitate the remodeling process. The use of decellularized ureteric grafts may represent a novel therapeutic method in reconstruction of ureteric defects. PMID:26157796

  20. Tissue-engineered vascular grafts transform into mature blood vessels via an inflammation-mediated process of vascular remodeling.

    PubMed

    Roh, Jason D; Sawh-Martinez, Rajendra; Brennan, Matthew P; Jay, Steven M; Devine, Lesley; Rao, Deepak A; Yi, Tai; Mirensky, Tamar L; Nalbandian, Ani; Udelsman, Brooks; Hibino, Narutoshi; Shinoka, Toshiharu; Saltzman, W Mark; Snyder, Edward; Kyriakides, Themis R; Pober, Jordan S; Breuer, Christopher K

    2010-03-01

    Biodegradable scaffolds seeded with bone marrow mononuclear cells (BMCs) are the earliest tissue-engineered vascular grafts (TEVGs) to be used clinically. These TEVGs transform into living blood vessels in vivo, with an endothelial cell (EC) lining invested by smooth muscle cells (SMCs); however, the process by which this occurs is unclear. To test if the seeded BMCs differentiate into the mature vascular cells of the neovessel, we implanted an immunodeficient mouse recipient with human BMC (hBMC)-seeded scaffolds. As in humans, TEVGs implanted in a mouse host as venous interposition grafts gradually transformed into living blood vessels over a 6-month time course. Seeded hBMCs, however, were no longer detectable within a few days of implantation. Instead, scaffolds were initially repopulated by mouse monocytes and subsequently repopulated by mouse SMCs and ECs. Seeded BMCs secreted significant amounts of monocyte chemoattractant protein-1 and increased early monocyte recruitment. These findings suggest TEVGs transform into functional neovessels via an inflammatory process of vascular remodeling.

  1. Fabrication and development of artificial osteochondral constructs based on cancellous bone/hydrogel hybrid scaffold.

    PubMed

    Song, Kedong; Li, Liying; Yan, Xinyu; Zhang, Yu; Li, Ruipeng; Wang, Yiwei; Wang, Ling; Wang, Hong; Liu, Tianqing

    2016-06-01

    Using tissue engineering techniques, an artificial osteochondral construct was successfully fabricated to treat large osteochondral defects. In this study, porcine cancellous bones and chitosan/gelatin hydrogel scaffolds were used as substitutes to mimic bone and cartilage, respectively. The porosity and distribution of pore size in porcine bone was measured and the degradation ratio and swelling ratio for chitosan/gelatin hydrogel scaffolds was also determined in vitro. Surface morphology was analyzed with the scanning electron microscope (SEM). The physicochemical properties and the composition were tested by using an infrared instrument. A double layer composite scaffold was constructed via seeding adipose-derived stem cells (ADSCs) induced to chondrocytes and osteoblasts, followed by inoculation in cancellous bones and hydrogel scaffolds. Cell proliferation was assessed through Dead/Live staining and cellular activity was analyzed with IpWin5 software. Cell growth, adhesion and formation of extracellular matrix in composite scaffolds blank cancellous bones or hydrogel scaffolds were also analyzed. SEM analysis revealed a super porous internal structure of cancellous bone scaffolds and pore size was measured at an average of 410 ± 59 μm while porosity was recorded at 70.6 ± 1.7 %. In the hydrogel scaffold, the average pore size was measured at 117 ± 21 μm and the porosity and swelling rate were recorded at 83.4 ± 0.8 % and 362.0 ± 2.4 %, respectively. Furthermore, the remaining hydrogel weighed 80.76 ± 1.6 % of the original dry weight after hydration in PBS for 6 weeks. In summary, the cancellous bone and hydrogel composite scaffold is a promising biomaterial which shows an essential physical performance and strength with excellent osteochondral tissue interaction in situ. ADSCs are a suitable cell source for osteochondral composite reconstruction. Moreover, the bi-layered scaffold significantly enhanced cell proliferation compared to the cells seeded on

  2. Fabrication and development of artificial osteochondral constructs based on cancellous bone/hydrogel hybrid scaffold.

    PubMed

    Song, Kedong; Li, Liying; Yan, Xinyu; Zhang, Yu; Li, Ruipeng; Wang, Yiwei; Wang, Ling; Wang, Hong; Liu, Tianqing

    2016-06-01

    Using tissue engineering techniques, an artificial osteochondral construct was successfully fabricated to treat large osteochondral defects. In this study, porcine cancellous bones and chitosan/gelatin hydrogel scaffolds were used as substitutes to mimic bone and cartilage, respectively. The porosity and distribution of pore size in porcine bone was measured and the degradation ratio and swelling ratio for chitosan/gelatin hydrogel scaffolds was also determined in vitro. Surface morphology was analyzed with the scanning electron microscope (SEM). The physicochemical properties and the composition were tested by using an infrared instrument. A double layer composite scaffold was constructed via seeding adipose-derived stem cells (ADSCs) induced to chondrocytes and osteoblasts, followed by inoculation in cancellous bones and hydrogel scaffolds. Cell proliferation was assessed through Dead/Live staining and cellular activity was analyzed with IpWin5 software. Cell growth, adhesion and formation of extracellular matrix in composite scaffolds blank cancellous bones or hydrogel scaffolds were also analyzed. SEM analysis revealed a super porous internal structure of cancellous bone scaffolds and pore size was measured at an average of 410 ± 59 μm while porosity was recorded at 70.6 ± 1.7 %. In the hydrogel scaffold, the average pore size was measured at 117 ± 21 μm and the porosity and swelling rate were recorded at 83.4 ± 0.8 % and 362.0 ± 2.4 %, respectively. Furthermore, the remaining hydrogel weighed 80.76 ± 1.6 % of the original dry weight after hydration in PBS for 6 weeks. In summary, the cancellous bone and hydrogel composite scaffold is a promising biomaterial which shows an essential physical performance and strength with excellent osteochondral tissue interaction in situ. ADSCs are a suitable cell source for osteochondral composite reconstruction. Moreover, the bi-layered scaffold significantly enhanced cell proliferation compared to the cells seeded on

  3. Osteochondral interface generation by rabbit bone marrow stromal cells and osteoblasts coculture.

    PubMed

    Chen, Kelei; Teh, Thomas Kok Hiong; Ravi, Sujata; Toh, Siew Lok; Goh, James Cho Hong

    2012-09-01

    Physiological osteochondral interface regeneration is a significant challenge. This study aims to investigate the effect of the coculture of chondrogenic rabbit bone marrow stromal cells (rBMSCs) with rabbit osteoblasts in a specially designed two-dimensional (2D)-three-dimensional (3D) co-interface culture to develop the intermediate osteochondral region in vitro. The 2D-3D coculture system was set up by first independently culturing chondrogenic rBMSCs on a scaffold and osteoblasts in cell culture plates, and subsequently placed in contact and cocultured. As control, samples not cocultured with osteoblasts were used. The regulatory effects exerted by osteoblasts on chondrogenic rBMSCs were quantified by real-time polymerase chain reaction. To study the effect of coculture on cells located in different parts of the scaffold, samples were separated into two parts and significantly different gene expression patterns were found between them. In comparison with the control group, a significant moderate downregulation of chondrogenic marker genes, such as Collagen II and Aggrecan was observed. However, the Sox-9 and Collagen I expression increased. More importantly, chondrogenic rBMSCs in the coculture system were shown to form the osteochondral interface layer by expressing calcified cartilage zone specific extracellular matrix marker Collagen X and the hypertrophic chondrocyte marker MMP-13, which were not observed in the control group. Specifically, only the chondrogenic rBMSC layer in contact with the osteoblasts expressed Collagen X and MMP-13, indicating the positive influence of the coculture upon interface formation. Biochemical analyses, histology results, and immunohistochemical staining further supported this observation. In conclusion, this study revealed that specific regulatory stimulations from osteoblasts in the 2D-3D interface coculture system could induce the formation of ostochondral interface for the purpose of osteochondral tissue engineering. PMID

  4. First Metatarsophalangeal Joint Arthroscopy for Osteochondral Lesions.

    PubMed

    Sherman, Thomas I; Kern, Michael; Marcel, John; Butler, Alexander; McGuigan, Francis X

    2016-06-01

    Small-joint arthroscopy has supplanted open procedures because it offers the potential for improvement in joint visualization, reduced scarring, and accelerated recovery. Despite these advantages, arthroscopy of the first metatarsophalangeal joint is not commonly performed and reports of its use are lacking. The reason for this is not clear but may be because of perceived technical complexity and poorly defined indications. In our experience, however, arthroscopy of the first metatarsophalangeal joint is a versatile procedure that facilitates treatment of many different pathologic processes through a minimally invasive approach with few complications. We present our technique for arthroscopic management of osteochondral lesions of the hallux. PMID:27656371

  5. Tissue-Specific Expression Patterns of MicroRNA during Acute Graft-versus-Host Disease in the Rat

    PubMed Central

    Jalapothu, Dasaradha; Boieri, Margherita; Crossland, Rachel E.; Shah, Pranali; Butt, Isha A.; Norden, Jean; Dressel, Ralf; Dickinson, Anne M.; Inngjerdingen, Marit

    2016-01-01

    MicroRNAs (miRNA) have emerged as central regulators of diverse biological processes and contribute to driving pathology in several diseases. Acute graft-versus-host disease (aGvHD) represents a major complication after allogeneic hematopoietic stem cell transplantation, caused by alloreactive donor T cells attacking host tissues leading to inflammation and tissue destruction. Changes in miRNA expression patterns occur during aGvHD, and we hypothesized that we could identify miRNA signatures in target tissues of aGvHD that may potentially help understand the underlying molecular pathology of the disease. We utilized a rat model of aGvHD with transplantation of fully MHC-mismatched T cell depleted bone marrow, followed by infusion of donor T cells. The expression pattern of 423 rat miRNAs was investigated in skin, gut, and lung tissues and intestinal T cells with the NanoString hybridization platform, in combination with validation by quantitative PCR. MHC-matched transplanted rats were included as controls. In the skin, upregulation of miR-34b and downregulation of miR-326 was observed, while in the intestines, we detected downregulation of miR-743b and a trend toward downregulation of miR-345-5p. Thus, tissue-specific expression patterns of miRNAs were observed. Neither miR-326 nor miR-743b has previously been associated with aGvHD. Moreover, we identified upregulation of miR-146a and miR-155 in skin tissue of rats suffering from aGvHD. Analysis of intestinal T cells indicated 23 miRNAs differentially regulated between aGvHD and controls. Two of these miRNAs were differentially expressed either in skin (miR-326) or in intestinal (miR-345-5p) tissue. Comparison of intestinal and peripheral blood T cells indicated common dysregulated expression of miR-99a, miR-223, miR-326, and miR-345-5p. Analysis of predicted gene targets for these miRNAs indicated potential targeting of an inflammatory network both in skin and in the intestines that may further regulate

  6. Tissue-Specific Expression Patterns of MicroRNA during Acute Graft-versus-Host Disease in the Rat

    PubMed Central

    Jalapothu, Dasaradha; Boieri, Margherita; Crossland, Rachel E.; Shah, Pranali; Butt, Isha A.; Norden, Jean; Dressel, Ralf; Dickinson, Anne M.; Inngjerdingen, Marit

    2016-01-01

    MicroRNAs (miRNA) have emerged as central regulators of diverse biological processes and contribute to driving pathology in several diseases. Acute graft-versus-host disease (aGvHD) represents a major complication after allogeneic hematopoietic stem cell transplantation, caused by alloreactive donor T cells attacking host tissues leading to inflammation and tissue destruction. Changes in miRNA expression patterns occur during aGvHD, and we hypothesized that we could identify miRNA signatures in target tissues of aGvHD that may potentially help understand the underlying molecular pathology of the disease. We utilized a rat model of aGvHD with transplantation of fully MHC-mismatched T cell depleted bone marrow, followed by infusion of donor T cells. The expression pattern of 423 rat miRNAs was investigated in skin, gut, and lung tissues and intestinal T cells with the NanoString hybridization platform, in combination with validation by quantitative PCR. MHC-matched transplanted rats were included as controls. In the skin, upregulation of miR-34b and downregulation of miR-326 was observed, while in the intestines, we detected downregulation of miR-743b and a trend toward downregulation of miR-345-5p. Thus, tissue-specific expression patterns of miRNAs were observed. Neither miR-326 nor miR-743b has previously been associated with aGvHD. Moreover, we identified upregulation of miR-146a and miR-155 in skin tissue of rats suffering from aGvHD. Analysis of intestinal T cells indicated 23 miRNAs differentially regulated between aGvHD and controls. Two of these miRNAs were differentially expressed either in skin (miR-326) or in intestinal (miR-345-5p) tissue. Comparison of intestinal and peripheral blood T cells indicated common dysregulated expression of miR-99a, miR-223, miR-326, and miR-345-5p. Analysis of predicted gene targets for these miRNAs indicated potential targeting of an inflammatory network both in skin and in the intestines that may further regulate

  7. The effect of interface microstructure on interfacial shear strength for osteochondral scaffolds based on biomimetic design and 3D printing.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; Jin, Zhongmin

    2015-01-01

    Interface integration between chondral phase and osseous phase is crucial in engineered osteochondral scaffolds. However, the integration was poorly understood and commonly failed to meet the need of osteochondral scaffolds. In this paper, a biphasic polyethylene glycol (PEG)/β-tricalcium phosphate (β-TCP) scaffold with enhanced interfacial integration was developed. The chondral phase was a PEG hydrogel. The osseous phase was a β-TCP ceramic scaffold. The PEG hydrogel was directly cured on the ceramic interface layer by layer to fabricate osteochondral scaffolds by 3D printing technology. Meanwhile, a series of interface structure were designed with different interface pore area percentages (0/10/20/30/40/50/60%), and interfacial shear test was applied for interface structure optimization (n=6 samples/group). The interfacial shear strength of 30% pore area group was nearly three folds improved compared with that of 0% pore area percentage group, and more than fifty folds improved compared with that of traditional integration (5.91±0.59 kPa). In conclusion, the biomimetic PEG/β-TCP scaffolds with interface structure enhanced integration show promising potential application for osteochondral tissue engineering.

  8. The effect of interface microstructure on interfacial shear strength for osteochondral scaffolds based on biomimetic design and 3D printing.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; Jin, Zhongmin

    2015-01-01

    Interface integration between chondral phase and osseous phase is crucial in engineered osteochondral scaffolds. However, the integration was poorly understood and commonly failed to meet the need of osteochondral scaffolds. In this paper, a biphasic polyethylene glycol (PEG)/β-tricalcium phosphate (β-TCP) scaffold with enhanced interfacial integration was developed. The chondral phase was a PEG hydrogel. The osseous phase was a β-TCP ceramic scaffold. The PEG hydrogel was directly cured on the ceramic interface layer by layer to fabricate osteochondral scaffolds by 3D printing technology. Meanwhile, a series of interface structure were designed with different interface pore area percentages (0/10/20/30/40/50/60%), and interfacial shear test was applied for interface structure optimization (n=6 samples/group). The interfacial shear strength of 30% pore area group was nearly three folds improved compared with that of 0% pore area percentage group, and more than fifty folds improved compared with that of traditional integration (5.91±0.59 kPa). In conclusion, the biomimetic PEG/β-TCP scaffolds with interface structure enhanced integration show promising potential application for osteochondral tissue engineering. PMID:25491954

  9. Histological characterization and quantification of cellular events following neural and fibroblast(-like) stem cell grafting in healthy and demyelinated CNS tissue.

    PubMed

    Praet, Jelle; Santermans, Eva; Reekmans, Kristien; de Vocht, Nathalie; Le Blon, Debbie; Hoornaert, Chloé; Daans, Jasmijn; Goossens, Herman; Berneman, Zwi; Hens, Niel; Van der Linden, Annemie; Ponsaerts, Peter

    2014-01-01

    Preclinical animal studies involving intracerebral (stem) cell grafting are gaining popularity in many laboratories due to the reported beneficial effects of cell grafting on various diseases or traumata of the central nervous system (CNS). In this chapter, we describe a histological workflow to characterize and quantify cellular events following neural and fibroblast(-like) stem cell grafting in healthy and demyelinated CNS tissue. First, we provide standardized protocols to isolate and culture eGFP(+) neural and fibroblast(-like) stem cells from embryonic mouse tissue. Second, we describe flow cytometric procedures to determine cell viability, eGFP transgene expression, and the expression of different stem cell lineage markers. Third, we explain how to induce reproducible demyelination in the CNS of mice by means of cuprizone administration, a validated mouse model for human multiple sclerosis. Fourth, the technical procedures for cell grafting in the CNS are explained in detail. Finally, an optimized and validated workflow for the quantitative histological analysis of cell graft survival and endogenous astroglial and microglial responses is provided. PMID:25173390

  10. Osteochondritis dissecans of the capitellum in adolescents

    PubMed Central

    van Bergen, Christiaan JA; van den Ende, Kimberly IM; ten Brinke, Bart; Eygendaal, Denise

    2016-01-01

    Osteochondritis dissecans (OCD) is a disorder of articular cartilage and subchondral bone. In the elbow, an OCD is localized most commonly at the humeral capitellum. Teenagers engaged in sports that involve repetitive stress on the elbow are at risk. A high index of suspicion is warranted to prevent delay in the diagnosis. Plain radiographs may disclose the lesion but computed tomography and magnetic resonance imaging are more accurate in the detection of OCD. To determine the best treatment option it is important to differentiate between stable and unstable OCD lesions. Stable lesions can be initially treated nonoperatively with elbow rest or activity modification and physical therapy. Unstable lesions and stable lesions not responding to conservative therapy require a surgical approach. Arthroscopic debridement and microfracturing has become the standard initial procedure for treatment of capitellar OCD. Numerous other surgical options have been reported, including internal fixation of large fragments and osteochondral autograft transfer. The aim of this article is to provide a current concepts review of the etiology, clinical presentation, diagnosis, treatment, and outcomes of elbow OCD. PMID:26925381

  11. Phthalate esters affect maturation and function of primate testis tissue ectopically grafted in mice.

    PubMed

    Rodriguez-Sosa, Jose R; Bondareva, Alla; Tang, Lin; Avelar, Gleide F; Coyle, Krysta M; Modelski, Mark; Alpaugh, Whitney; Conley, Alan; Wynne-Edwards, Katherine; França, Luiz R; Meyers, Stuart; Dobrinski, Ina

    2014-12-01

    Di-n-Butyl (DBP) and Di-(2-EthylHexyl) (DEHP) phthalates can leach from daily-use products resulting in environmental exposure. In male rodents, phthalate exposure results in reproductive effects. To evaluate effects on the immature primate testis, testis fragments from 6-month-old rhesus macaques were grafted subcutaneously to immune-deficient mice, which were exposed to 0, 10, or 500 mg/kg of DBP or DEHP for 14 weeks or 28 weeks (DBP only). DBP exposure reduced the expression of key steroidogenic genes, indicating that Leydig cell function was compromised. Exposure to 500 mg/kg impaired tubule formation and germ cell differentiation and reduced numbers of spermatogonia. Exposure to 10 mg/kg did not affect development, but reduced Sertoli cell number and resulted in increased expression of inhibin B. Exposure to DEHP for 14 week also affected steroidogenic genes expression. Therefore, long-term exposure to phthalate esters affected development and function of the primate testis in a time and dosage dependent manner.

  12. Phthalate esters affect maturation and function of primate testis tissue ectopically grafted in mice

    PubMed Central

    Rodriguez-Sosa, Jose R; Bondareva, Alla; Tang, Lin; Avelar, Gleide F.; Coyle, Krysta M.; Modelski, Mark; Alpaugh, Whitney; Conley, Alan; Wynne-Edwards, Katherine; França, Luiz R; Meyers, Stuart; Dobrinski, Ina

    2014-01-01

    Di-n-Butyl (DBP) and Di-(2-EthylHexyl) (DEHP) phthalates can leach from daily-use products resulting in environmental exposure. In male rodents, phthalate exposure results in reproductive effects. To evaluate effects on the immature primate testis, testis fragments from 6-month-old rhesus macaques were grafted subcutaneously to immune-deficient mice, which were exposed to 0, 10, or 500 mg/kg of DBP or DEHP for 14 weeks or 28 weeks (DBP only). DBP exposure reduced the expression of key steroidogenic genes, indicating that Leydig cell function was compromised. Exposure to 500 mg/kg impaired tubule formation and germ cell differentiation and reduced numbers of spermatogonia. Exposure to 10 mg/kg did not affect development, but reduced Sertoli cell number and resulted in increased expression of inhibin B. Exposure to DEHP for 14 week also affected steroidogenic genes expression. Therefore, long-term exposure to phthalate esters affected development and function of the primate testis in a time and dosage dependent manner. PMID:25450860

  13. Comparison of ADM and Connective Tissue Graft as the Membrane in Class II Furcation Defect Regeneration: A Randomized Clinical Trial

    PubMed Central

    Esfahanian, Vahid; Farhad, Shirin; Sadighi Shamami, Mehrnaz

    2014-01-01

    Background and aims. Furcally-involved teeth present unique challenges to the success of periodontal therapy and influence treatment outcomes. This study aimed to assess to compare use of ADM and connective tissue membrane in class II furcation defect regeneration. Materials and methods. 10 patient with 2 bilaterally class II furcation defects in first and/or second maxilla or man-dibular molar without interproximal furcation involvement, were selected. Four weeks after initial phase of treatment, before and thorough the surgery pocket depth (PD), clinical attachment level to stent (CAL-S), free gingival margin to stent(FGM-S) , crestal bone to stent (Crest-S), horizontal defect depth to stent (HDD-S) and vertical defect depth to stent (VDD-S) and crestal bone to defect depth measured from stent margin. Thereafter, one side randomly treated using connective tissue and DFDBA (study group) and opposite side received ADM and DFDBA (control group). After 6 months, soft and hard tissue parameters measured again in re-entry. Results. Both groups presented improvements after therapies (P & 0.05). No inter-group differences were seen in PD re-duction (P = 0.275), CAL gain (P = 0.156), free gingival margin (P = 0.146), crest of the bone (P = 0.248), reduction in horizontal defects depth (P = 0.139) and reduction in vertical defects depth (P = 0.149). Conclusion. Both treatments modalities have potential of regeneration without any adverse effect on healing process. Connective tissue grafts did not have significant higher bone fill compared to that of ADM. PMID:25093054

  14. Covalent immobilization of stem cell inducing/recruiting factor and heparin on cell-free small-diameter vascular graft for accelerated in situ tissue regeneration.

    PubMed

    Shafiq, Muhammad; Jung, Youngmee; Kim, Soo Hyun

    2016-06-01

    The development of cell-free vascular grafts has tremendous potential for tissue engineering. However, thrombus formation, less-than-ideal cell infiltration, and a lack of growth potential limit the application of electrospun scaffolds for in situ tissue-engineered vasculature. To overcome these challenges, here we present development of an acellular tissue-engineered vessel based on electrospun poly(L-lactide-co-ɛ-caprolactone) scaffolds. Heparin was conjugated to suppress thrombogenic responses, and substance P (SP) was immobilized to recruit host cells. SP was released in a sustained manner from scaffolds and recruited human bone marrow-derived mesenchymal stem cells. The biocompatibility and biological performance of the grafts were evaluated by in vivo experiments involving subcutaneous scaffold implantation in Sprague-Dawley rats (n = 12) for up to 4 weeks. Histological analysis revealed a higher extent of accumulative host cell infiltration, neotissue formation, collagen deposition, and elastin deposition in scaffolds containing either SP or heparin/SP than in the control groups. We also observed the presence of a large number of laminin-positive blood vessels, von Willebrand factor (vWF(+) ) cells, and alpha smooth muscle actin-positive cells in the explants containing SP and heparin/SP. Additionally, SP and heparin/SP grafts showed the existence of CD90(+) and CD105(+) MSCs and induced a large number of M2 macrophages to infiltrate the graft wall compared with that observed with the control group. Our cell-free grafts could enhance vascular regeneration by endogenous cell recruitment and by mediating macrophage polarization into the M2 phenotype, suggesting that these constructs may be a promising cell-free graft candidate and are worthy of further in vivo evaluation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1352-1371, 2016. PMID:26822178

  15. Insulin-like Growth Factor-I and Slow, Bi-directional Perfusion Enhance the Formation of Tissue-Engineered Cardiac Grafts

    PubMed Central

    Cheng, Mingyu; Moretti, Matteo; Engelmayr, George C.

    2009-01-01

    Biochemical and mechanical signals enabling cardiac regeneration can be elucidated using in vitro tissue-engineering models. We hypothesized that insulin-like growth factor-I (IGF) and slow, bi-directional perfusion could act independently and interactively to enhance the survival, differentiation, and contractile performance of tissue-engineered cardiac grafts. Heart cells were cultured on three-dimensional porous scaffolds in medium with or without supplemental IGF and in the presence or absence of slow, bi-directional perfusion that enhanced transport and provided shear stress. Structural, molecular, and electrophysiologic properties of the resulting grafts were quantified on culture day 8. IGF had independent, beneficial effects on apoptosis (p < 0.01), cellular viability (p < 0.01), contractile amplitude (p < 0.01), and excitation threshold (p < 0.01). Perfusion independently affected the four aforementioned parameters and also increased amounts of cardiac troponin-I (p < 0.01), connexin-43 (p < 0.05), and total protein (p < 0.01) in the grafts. Interactive effects of IGF and perfusion on apoptosis were also present (p < 0.01). Myofibrillogenesis and spontaneous contractility were present only in grafts cultured with perfusion, although contractility was inducible by electrical field stimulation of grafts from all groups. Our findings demonstrate that multi-factorial stimulation of tissue-engineered cardiac grafts using IGF and perfusion resulted in independent and interactive effects on heart cell survival, differentiation, and contractility. PMID:18759675

  16. The influence of stromal cells on the pigmentation of tissue-engineered dermo-epidermal skin grafts.

    PubMed

    Biedermann, Thomas; Böttcher-Haberzeth, Sophie; Klar, Agnieszka S; Widmer, Daniel S; Pontiggia, Luca; Weber, Andreas D; Weber, Daniel M; Schiestl, Clemens; Meuli, Martin; Reichmann, Ernst

    2015-03-01

    It has been shown in vitro that melanocyte proliferation and function in palmoplantar skin is regulated by mesenchymal factors derived from fibroblasts. In this study, we investigated in vivo the influence of mesenchymal-epithelial interactions in human tissue-engineered skin substitutes reconstructed from palmar- and nonpalmoplantar-derived fibroblasts. Tissue-engineered dermo-epidermal analogs based on collagen type I hydrogels were populated with either human palmar or nonpalmoplantar fibroblasts and seeded with human nonpalmoplantar-derived melanocytes and keratinocytes. These skin substitutes were transplanted onto full-thickness skin wounds of immunoincompetent rats. Four weeks after transplantation the development of skin color was measured and grafts were excised and analyzed with regard to epidermal characteristics, in particular melanocyte number and function. Skin substitutes containing palmar-derived fibroblasts in comparison to nonpalmoplantar-derived fibroblasts showed (a) a significantly lighter pigmentation; (b) a reduced amount of epidermal melanin granules; and (c) a distinct melanosome expression. However, the number of melanocytes in the basal layer remained similar in both transplantation groups. These findings demonstrate that human palmar fibroblasts regulate the function of melanocytes in human pigmented dermo-epidermal skin substitutes after transplantation, whereas the number of melanocytes remains constant. This underscores the influence of site-specific stromal cells and their importance when constructing skin substitutes for clinical application. PMID:25300246

  17. The Influence of Stromal Cells on the Pigmentation of Tissue-Engineered Dermo-Epidermal Skin Grafts

    PubMed Central

    Biedermann, Thomas; Böttcher-Haberzeth, Sophie; Klar, Agnieszka S.; Widmer, Daniel S.; Pontiggia, Luca; Weber, Andreas D.; Weber, Daniel M.; Schiestl, Clemens; Meuli, Martin

    2015-01-01

    It has been shown in vitro that melanocyte proliferation and function in palmoplantar skin is regulated by mesenchymal factors derived from fibroblasts. In this study, we investigated in vivo the influence of mesenchymal–epithelial interactions in human tissue-engineered skin substitutes reconstructed from palmar- and nonpalmoplantar-derived fibroblasts. Tissue-engineered dermo-epidermal analogs based on collagen type I hydrogels were populated with either human palmar or nonpalmoplantar fibroblasts and seeded with human nonpalmoplantar-derived melanocytes and keratinocytes. These skin substitutes were transplanted onto full-thickness skin wounds of immunoincompetent rats. Four weeks after transplantation the development of skin color was measured and grafts were excised and analyzed with regard to epidermal characteristics, in particular melanocyte number and function. Skin substitutes containing palmar-derived fibroblasts in comparison to nonpalmoplantar-derived fibroblasts showed (a) a significantly lighter pigmentation; (b) a reduced amount of epidermal melanin granules; and (c) a distinct melanosome expression. However, the number of melanocytes in the basal layer remained similar in both transplantation groups. These findings demonstrate that human palmar fibroblasts regulate the function of melanocytes in human pigmented dermo-epidermal skin substitutes after transplantation, whereas the number of melanocytes remains constant. This underscores the influence of site-specific stromal cells and their importance when constructing skin substitutes for clinical application. PMID:25300246

  18. Fabrication and characterisation of biomimetic, electrospun gelatin fibre scaffolds for tunica media-equivalent, tissue engineered vascular grafts.

    PubMed

    Elsayed, Y; Lekakou, C; Labeed, F; Tomlins, P

    2016-04-01

    It is increasingly recognised that biomimetic, natural polymers mimicking the extracellular matrix (ECM) have low thrombogenicity and functional motifs that regulate cell-matrix interactions, with these factors being critical for tissue engineered vascular grafts especially grafts of small diameter. Gelatin constitutes a low cost substitute of soluble collagen but gelatin scaffolds so far have shown generally low strength and suture retention strength. In this study, we have devised the fabrication of novel, electrospun, multilayer, gelatin fibre scaffolds, with controlled fibre layer orientation, and optimised gelatin crosslinking to achieve not only compliance equivalent to that of coronary artery but also for the first time strength of the wet tubular acellular scaffold (swollen with absorbed water) same as that of the tunica media of coronary artery in both circumferential and axial directions. Most importantly, for the first time for natural scaffolds and in particular gelatin, high suture retention strength was achieved in the range of 1.8-1.94 N for wet acellular scaffolds, same or better than that for fresh saphenous vein. The study presents the investigations to relate the electrospinning process parameters to the microstructural parameters of the scaffold, which are further related to the mechanical performance data of wet, crosslinked, electrospun scaffolds in both circumferential and axial tubular directions. The scaffolds exhibited excellent performance in human smooth muscle cell (SMC) proliferation, with SMCs seeded on the top surface adhering, elongating and aligning along the local fibres, migrating through the scaffold thickness and populating a transverse distance of 186 μm and 240 μm 9 days post-seeding for scaffolds of initial dry porosity of 74 and 83%, respectively. PMID:26838874

  19. Recent Advances in Cartilage Tissue Engineering: From the Choice of Cell Sources to the Use of Bioreactors

    NASA Astrophysics Data System (ADS)

    Martin, Ivan; Démarteau, Olivier; Braccini, Alessandra

    Grafting engineered cartilage tissues represents a promising approach for the repair of joint injuries. Recent animal experiments have demonstrated that tissues engineered by culturing chondrocytes on 3D scaffolds in bioreactors provide functional templates for orderly repair of large osteochondral lesions. To date, however, a reproducible generation of uniform cartilage tissues of predefined size starting from adult human cells has not been achieved. In this paper we review some of the recent advances and challenges ahead in the identification of appropriate (i) cell sources, (ii) bioactive factors, (iii) 3D scaffolds and (iv) bioreactors for human cartilage tissue engineering. We also present an example of how integrated efforts in these different areas can help addressing fundamental questions and advancing the field of cartilage tissue engineering towards clinical use. The presented experiment demonstrates that human nasal chondrocytes are responsive to dynamic loading and thus could be further investigated as a cell source for implantation in a joint environment.

  20. Initial evaluation of the use of USPIO cell labeling and noninvasive MR monitoring of human tissue-engineered vascular grafts in vivo.

    PubMed

    Nelson, G N; Roh, J D; Mirensky, T L; Wang, Y; Yi, T; Tellides, G; Pober, J S; Shkarin, P; Shapiro, E M; Saltzman, W M; Papademetris, X; Fahmy, T M; Breuer, C K

    2008-11-01

    This pilot study examines noninvasive MR monitoring of tissue-engineered vascular grafts (TEVGs) in vivo using cells labeled with iron oxide nanoparticles. Human aortic smooth muscle cells (hASMCs) were labeled with ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles. The labeled hASMCs, along with human aortic endothelial cells, were incorporated into eight TEVGs and were then surgically implanted as aortic interposition grafts in a C.B-17 SCID/bg mouse host. USPIO-labeled hASMCs persisted in the grafts throughout a 3 wk observation period and allowed noninvasive MR imaging of the human TEVGs for real-time, serial monitoring of hASMC retention. This study demonstrates the feasibility of applying noninvasive imaging techniques for evaluation of in vivo TEVG performance. PMID:18711027

  1. OSTEOCHONDRAL INTERFACE REGENERATION OF THE RABBIT KNEE WITH MACROSCOPIC GRADIENTS OF BIOACTIVE SIGNALS

    PubMed Central

    Dormer, Nathan H.; Singh, Milind; Zhao, Liang; Mohan, Neethu; Berkland, Cory J.; Detamore, Michael S.

    2011-01-01

    To date, most interfacial tissue engineering approaches have utilized stratified designs, in which there are two or more discrete layers comprising the interface. Continuously-graded interfacial designs, where there is no discrete transition from one tissue type to another, are gaining attention as an alternative to stratified designs. Given that osteochondral regeneration holds the potential to enhance cartilage regeneration by leveraging the healing capacity of the underlying bone, we endeavored to introduce a continuously graded approach to osteochondral regeneration. The purpose of this study was thus to evaluate the performance of a novel gradient-based scaffolding approach to regenerate osteochondral defects in the New Zealand White rabbit femoral condyle. Bioactive plugs were constructed from poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres with a continuous gradient transition between cartilage-promoting and bone-promoting growth factors. At six and 12 weeks of healing, results suggested that the implants provided support for the neo-synthesized tissue, and the gradient in bioactive signaling may have been beneficial for bone and cartilage regeneration compared to the blank control implant, as evidenced by histology. In addition, the effects of pre-seeding gradient scaffolds with umbilical cord mesenchymal stromal cells (UCMSCs) from the Wharton’s jelly of New Zealand White rabbits were evaluated. Results indicated that there may be regenerative benefits to pre-localizing UCMSCs within scaffold interiors. The inclusion of bioactive factors in a gradient-based scaffolding design is a promising new treatment strategy for defect repair in the femoral condyle. PMID:22009693

  2. Emerging genetic basis of osteochondritis dissecans

    PubMed Central

    Bates, J. Tyler; Jacobs, John C.; Shea, Kevin G.; Oxford, Julia Thom

    2014-01-01

    Genome-wide association studies provide an unbiased approach in the identification of genes that increase the risk for osteochondritis dissecans (OCD). OCD is a disorder of the bone and cartilage that affects humans, horses, pigs, dogs, and other mammals. Recent genome-wide association studies in humans, horses, and pigs are reviewed and genes identified. The identified genes tended to cluster with respect to function and biological processes such as the protein secretion pathway, extracellular matrix molecules, and growth plate maturation. Genome-wide association studies in humans are a critical next step in the effort to provide a better understanding of the causes of OCD, which will, in turn, allow preventive strategies for treatment of adolescent and young adults who are at risk for the development of degenerative joint disease due to the effects of OCD. PMID:24698039

  3. Biologically engineered protein-graft-poly(ethylene glycol) hydrogels: A cell-adhesive and plasmin-degradable biosynthetic material for tissue repair

    NASA Astrophysics Data System (ADS)

    Halstenberg, Sven

    2002-01-01

    The goal of the research presented in this dissertation was to create a biomimetic artificial material that exhibits functions of extracellular matrix relevant for improved nerve regeneration. Neural adhesion peptides were photoimmobilized on highly crosslinked poly(ethylene glycol)-based substrates that were otherwise non-adhesive. Neurons adhered in two-dimensional patterns for eleven hours, but no neurites extended. To enable neurite extension and nerve regeneration in three dimensions, and to address the need for specifically cell adhesive and cell degradable materials for clinical applications in tissue repair in general, an artificial protein was recombinantly expressed and purified that consisted of a repeating amino acid sequence based on fibrinogen and anti-thrombin III. The recombinant protein contained integrin-binding RGD sites, plasmin degradation sites, heparin binding sites, and six thiol-containing cysteine residues as grafting sites for poly(ethylene glycol) diacrylate via Michael-type conjugate addition. The resulting protein-graft-poly(ethylene glycol)acrylates were crosslinked by photopolymerization to form hydrogels. Although three-dimensional, RGD mediated and serine protease-dependent ingrowth of human fibroblasts into protein-graft-poly(ethylene glycol) hydrogels occurred, only surface neurite outgrowth was observed from chick dorsal root ganglia. Axonal outgrowth depended on the concentration of matrix-bound heparin, suggesting that improved mechanical strength of the hydrogels and possible immobilization of neuroactive factors due to the presence of heparin promoted neurite outgrowth. Together, the above results show that specific biological functions can be harnessed by protein-graft-poly(ethylene glycol) hydrogels to serve as matrices for tissue repair and regeneration. In particular, the two design objectives, specific cell adhesion and degradability by cell-associated proteases, were fulfilled by the material. In the future, this and

  4. Antibacterial and conductive injectable hydrogels based on quaternized chitosan-graft-polyaniline/oxidized dextran for tissue engineering.

    PubMed

    Zhao, Xin; Li, Peng; Guo, Baolin; Ma, Peter X

    2015-10-01

    Biomaterials with injectability, conductivity and antibacterial effect simultaneously have been rarely reported. Herein, we developed a new series of in situ forming antibacterial conductive degradable hydrogels using quaternized chitosan (QCS) grafted polyaniline with oxidized dextran as crosslinker. The chemical structures, morphologies, electrochemical property, conductivity, swelling ratio, rheological property, in vitro biodegradation and gelation time of hydrogels were characterized. Injectability was verified by in vivo subcutaneous injection on a Sprague Dawley rat. The antibacterial activity of the hydrogels was firstly evaluated employing antibacterial assay using Escherichia coli and Staphylococcus aureus in vitro. The hydrogels containing polyaniline showed enhanced antibacterial activity compared to QCS hydrogel, especially for hydrogels with 3 wt% polyaniline showing 95 kill% and 90kill% for E. coli and S. aureus, respectively. Compared with QCS hydrogel, the hydrogels with 3 wt% polyaniline still showed enhanced antibacterial activity for E. coli in vivo. The adipose-derived mesenchymal stem cells (ADMSCs) were used to evaluate the cytotoxicity of the hydrogels and hydrogels with polyaniline showed better cytocompatibility than QCS hydrogel. The electroactive hydrogels could significantly enhance the proliferation of C2C12 myoblasts compared to QCS hydrogel. This work opens the way to fabricate in situ forming antibacterial and electroactive degradable hydrogels as a new class of bioactive scaffolds for tissue regeneration applications.

  5. Surgical technique for the implantation of tissue engineered vascular grafts and subsequent in vivo monitoring.

    PubMed

    Koobatian, Maxwell T; Koenigsknecht, Carmon; Row, Sindhu; Andreadis, Stelios; Swartz, Daniel

    2015-01-01

    The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large animal model. A step by-step protocol for inter-positional placement of the TEV and real-time digital assessment of the TEV and native carotid arteries is described here. In vivo monitoring is made possible by the implantation of flow probes, catheters and ultrasonic crystals (capable of recording dynamic diameter changes of implanted TEVs and native carotid arteries) at the time of surgery. Once implanted, researchers can calculate arterial blood flow patterns, invasive blood pressure and artery diameter yielding parameters such as pulse wave velocity, augmentation index, pulse pressures and compliance. Data acquisition is accomplished using a single computer program for analysis throughout the duration of the experiment. Such invaluable data provides insight into TEV matrix remodeling, its resemblance to native/sham controls and overall TEV performance in vivo. PMID:25867203

  6. In-body optical stimulation formed connective tissue vascular grafts, "biotubes," with many capillaries and elastic fibers.

    PubMed

    Oie, Tomonori; Yamanami, Masashi; Ishibashi-Ueda, Hatsue; Kanda, Keiichi; Yaku, Hitoshi; Nakayama, Yasuhide

    2010-12-01

    The autologous biotube, developed by using in-body tissue architecture technology, is one of the most promising small-diameter vascular grafts in regenerative medicine. The walls of the biotubes obtained by a traditional silicone mold-based method were very thin, and this is still the primary obstacle while handling anastomosis, even though these biotubes have adequate pressure resistance ability. This pilot study showed the effect of optical stimulation of subcutaneous tissue formation in the body during the preparation of the biotubes. A blue light-emitting diode (LED) was embedded into a silicone rod as a mold. The biotube was prepared by placing the luminescent molds into the dorsal subcutaneous pouches of a pair of beagles (each weighing ~10 kg) for 2 weeks under photoirradiation. The wall thickness of the obtained biotubes was 506.9 ± 185.7 μm, which was remarkably more than that of the previous biotubes prepared by 2 months of embedding similarly in beagles' subcutaneous pouches (thickness, 77.2 ± 14.8 μm). Many capillaries with smooth muscle cells were infiltrated into the wall and concentrated in the internal layer. Interestingly, the formation of elastic fibers had already started along with collagen fibers, mostly with a regular circumferential orientation. The short-term in-body optical stimulation resulted in the rapid formation of a biotube. These phenomena will allow easy surgical handling and may induce vascular maturation in histology during the acute phase after implantation.

  7. The subepithelial connective tissue pedicle graft combined with the coronally advanced flap for restoring missing papilla: a report of two cases.

    PubMed

    De Castro Pinto, Rodrigo Carlos Nahas; Colombini, Bella Luna; Ishikiriama, Sérgio Kiyoshi; Chambrone, Leandro; Pustiglioni, Francisco Emílio; Romito, Giuseppe Alexandre

    2010-03-01

    This case report describes the clinical application of the coronally advanced flap procedure associated with the subepithelial connective tissue pedicle graft in the reconstruction of interdental papilla. This procedure was used in two distinct situations: to reconstruct missing papilla and cover two Miller Class IV gingival recessions between the maxillary right lateral incisor and canine (case 1) and to improve esthetics and restore missing papilla between the maxillary left central and lateral incisors (case 2). In case 1, there was a clinical attachment level gain, complete root coverage (canine), and an increase in papillary height. Case 2 showed similar improvements for the interdental papilla, ie, significant reduction of the black triangle. Subepithelial connective tissue pedicle graft associated with a coronally advanced flap yielded satisfactory esthetics and may be considered a viable approach for the treatment of missing papilla associated or not with recession-type defects. However, further investigation is required.

  8. Tissue-engineered vascular grafts for use in the treatment of congenital heart disease: from the bench to the clinic and back again.

    PubMed

    Patterson, Joseph T; Gilliland, Thomas; Maxfield, Mark W; Church, Spencer; Naito, Yuji; Shinoka, Toshiharu; Breuer, Christopher K

    2012-05-01

    Since the first tissue-engineered vascular graft (TEVG) was implanted in a child over a decade ago, growth in the field of vascular tissue engineering has been driven by clinical demand for improved vascular prostheses with performance and durability similar to an autologous blood vessel. Great strides were made in pediatric congenital heart surgery using the classical tissue engineering paradigm, and cell seeding of scaffolds in vitro remained the cornerstone of neotissue formation. Our second-generation bone marrow cell-seeded TEVG diverged from tissue engineering dogma with a design that induces the recipient to regenerate vascular tissue in situ. New insights suggest that neovessel development is guided by cell signals derived from both seeded cells and host inflammatory cells that infiltrate the graft. The identification of these signals and the regulatory interactions that influence cell migration, phenotype and extracellular matrix deposition during TEVG remodeling are yielding a next-generation TEVG engineered to guide neotissue regeneration without the use of seeded cells. These developments represent steady progress towards our goal of an off-the-shelf tissue-engineered vascular conduit for pediatric congenital heart surgery. PMID:22594331

  9. Photochemical tissue bonding

    DOEpatents

    Redmond, Robert W.; Kochevar, Irene E.

    2012-01-10

    Photochemical tissue bonding methods include the application of a photosensitizer to a tissue and/or tissue graft, followed by irradiation with electromagnetic energy to produce a tissue seal. The methods are useful for tissue adhesion, such as in wound closure, tissue grafting, skin grafting, musculoskeletal tissue repair, ligament or tendon repair and corneal repair.

  10. A rare case of an osteochondral lesion of the tarsal navicular with a subacute stress fracture in a high level athlete.

    PubMed

    Nunag, Perrico; Quah, Colin; Pillai, Anand

    2014-12-01

    In this report, an osteochondral lesion of the tarsal navicular associated with a subacute stress fracture in a professional basketball player surgical treatment is presented. The surgical technique involved extra-articular curettage, bone grafting and plate stabilisation. Postoperative CT scan confirmed that both the osteochondral lesion and the stress fracture healed. The talonavicular joint showed no signs of arthritis on imaging. Clinical foot scores showed marked improvement after surgery. At 6 months patient managed to return to competitive play without pain in the foot and ankle. The outcome of this case indicates that the combination of curettage, bone grating and plate stabilisation works well for this rare and potentially career ending dual lesions.

  11. Quantitative three-dimensional methodology to assess volumetric and profilometric outcome of subepithelial connective tissue grafting at pontic sites: a prospective pilot study.

    PubMed

    González-Martín, Oscar; Veltri, Mario; Moráguez, Osvaldo; Belser, Urs C

    2014-01-01

    The aim of this study was to describe a technique for the assessment of soft tissue volumetric and profilometric changes. The technique has been applied at the alveolar contour of mild to moderate horizontal ridge defects after soft tissue augmentation at pontic sites. A quantitative three-dimensional (3D) analysis based on laser scanning was used for the measurement of volume gain and horizontal changes of alveolar profile 5 months after a subepithelial connective tissue graft using a pouch approach in five patients. All the surgical sites healed uneventfully. A mean soft tissue volume increase of 35.9 mm3 was measured 5 months after the grafting procedure. The linear measurements showed that, in the area where the augmentation was performed, the distance between the preoperative vestibular profile and the postoperative one ranged from 0.16 to 2 mm. The described quantitative measurements based on 3D laser scanning appear to be an effective method for assessment of soft tissue changes in future studies. Additionally, within the limitation of a small sample size, the present data suggest that the investigated surgical technique can be considered when corrections of mild to moderate alveolar horizontal ridge atrophies at maxillary lateral incisor edentulous gaps are necessary.

  12. Intranigral grafts of fetal ventral mesencephalic tissue in adult 6-hydroxydopamine-lesioned rats can induce behavioral recovery.

    PubMed

    Johnston, R E; Becker, J B

    1997-01-01

    Intrastriatal grafts of fetal ventral mesencephalon in rats with unilateral 6-hydroxydopamine lesions can reduce and even reverse rotational behavior in response to direct and indirect dopamine agonists. These grafts can ameliorate deficits on simple spontaneous behaviors, but do not improve complex behaviors that require the skilled integration of the use of both paws. We report here that rats with grafts into the DA-depleted substantia nigra, that receive cyclosporine A, can experience recovery on spontaneous behaviors that mimic those observed in Parkinson's disease. Specific cyclosporine A treatment conditions can differentially affect whether intranigral grafts normalize paw use during initiation or termination of a movement sequence. These findings may have important implications for the treatment of Parkinson's disease. PMID:9171159

  13. Novel Vanadium-Loaded Ordered Collagen Scaffold Promotes Osteochondral Differentiation of Bone Marrow Progenitor Cells

    PubMed Central

    Cortizo, Ana M.; Ruderman, Graciela; Mazzini, Flavia N.; Molinuevo, M. Silvina; Mogilner, Ines G.

    2016-01-01

    Bone and cartilage regeneration can be improved by designing a functionalized biomaterial that includes bioactive drugs in a biocompatible and biodegradable scaffold. Based on our previous studies, we designed a vanadium-loaded collagen scaffold for osteochondral tissue engineering. Collagen-vanadium loaded scaffolds were characterized by SEM, FTIR, and permeability studies. Rat bone marrow progenitor cells were plated on collagen or vanadium-loaded membranes to evaluate differences in cell attachment, growth and osteogenic or chondrocytic differentiation. The potential cytotoxicity of the scaffolds was assessed by the MTT assay and by evaluation of morphological changes in cultured RAW 264.7 macrophages. Our results show that loading of VOAsc did not alter the grooved ordered structure of the collagen membrane although it increased membrane permeability, suggesting a more open structure. The VOAsc was released to the media, suggesting diffusion-controlled drug release. Vanadium-loaded membranes proved to be a better substratum than C0 for all evaluated aspects of BMPC biocompatibility (adhesion, growth, and osteoblastic and chondrocytic differentiation). In addition, there was no detectable effect of collagen or vanadium-loaded scaffolds on macrophage viability or cytotoxicity. Based on these findings, we have developed a new ordered collagen scaffold loaded with VOAsc that shows potential for osteochondral tissue engineering. PMID:27293438

  14. Efficient long-term survival of cell grafts after myocardial infarction with thick viable cardiac tissue entirely from pluripotent stem cells

    PubMed Central

    Matsuo, Takehiko; Masumoto, Hidetoshi; Tajima, Shuhei; Ikuno, Takeshi; Katayama, Shiori; Minakata, Kenji; Ikeda, Tadashi; Yamamizu, Kohei; Tabata, Yasuhiko; Sakata, Ryuzo; Yamashita, Jun K.

    2015-01-01

    Poor engraftment of cells after transplantation to the heart is a common and unresolved problem in the cardiac cell therapies. We previously generated cardiovascular cell sheets entirely from pluripotent stem cells with cardiomyocytes, endothelial cells and vascular mural cells. Though sheet transplantation showed a better engraftment and improved cardiac function after myocardial infarction, stacking limitation (up to 3 sheets) by hypoxia hampered larger structure formation and long-term survival of the grafts. Here we report an efficient method to overcome the stacking limitation. Insertion of gelatin hydrogel microspheres (GHMs) between each cardiovascular cell sheet broke the viable limitation via appropriate spacing and fluid impregnation with GHMs. Fifteen sheets with GHMs (15-GHM construct; >1 mm thickness) were stacked within several hours and viable after 1 week in vitro. Transplantation of 5-GHM constructs (≈2 × 106 of total cells) to a rat myocardial infarction model showed rapid and sustained functional improvements. The grafts were efficiently engrafted as multiple layered cardiovascular cells accompanied by functional capillary networks. Large engrafted cardiac tissues (0.8 mm thickness with 40 cell layers) successfully survived 3 months after TX. We developed an efficient method to generate thicker viable tissue structures and achieve long-term survival of the cell graft to the heart. PMID:26585309

  15. Efficient long-term survival of cell grafts after myocardial infarction with thick viable cardiac tissue entirely from pluripotent stem cells.

    PubMed

    Matsuo, Takehiko; Masumoto, Hidetoshi; Tajima, Shuhei; Ikuno, Takeshi; Katayama, Shiori; Minakata, Kenji; Ikeda, Tadashi; Yamamizu, Kohei; Tabata, Yasuhiko; Sakata, Ryuzo; Yamashita, Jun K

    2015-11-20

    Poor engraftment of cells after transplantation to the heart is a common and unresolved problem in the cardiac cell therapies. We previously generated cardiovascular cell sheets entirely from pluripotent stem cells with cardiomyocytes, endothelial cells and vascular mural cells. Though sheet transplantation showed a better engraftment and improved cardiac function after myocardial infarction, stacking limitation (up to 3 sheets) by hypoxia hampered larger structure formation and long-term survival of the grafts. Here we report an efficient method to overcome the stacking limitation. Insertion of gelatin hydrogel microspheres (GHMs) between each cardiovascular cell sheet broke the viable limitation via appropriate spacing and fluid impregnation with GHMs. Fifteen sheets with GHMs (15-GHM construct; >1 mm thickness) were stacked within several hours and viable after 1 week in vitro. Transplantation of 5-GHM constructs (≈2 × 10(6) of total cells) to a rat myocardial infarction model showed rapid and sustained functional improvements. The grafts were efficiently engrafted as multiple layered cardiovascular cells accompanied by functional capillary networks. Large engrafted cardiac tissues (0.8 mm thickness with 40 cell layers) successfully survived 3 months after TX. We developed an efficient method to generate thicker viable tissue structures and achieve long-term survival of the cell graft to the heart.

  16. Arthroscopic Management of Osteochondral Lesions of the Talus.

    PubMed

    Grambart, Sean T

    2016-10-01

    Osteochondral fractures of the ankle are typically caused by traumatic injuries of the ankle. Repetitive trauma can lead to further cartilage damage with subsequent increasing size of the lesion, ultimately leading to severe cartilage disorder and degenerative arthritis of the ankle. Arthroscopic bone marrow stimulation has been shown to be a highly successful option for patients with small osteochondral lesions. Studies show a higher failure rate for larger lesions and cystic changes that disrupt the subchondral plate. The threshold size seems to be 150 mm(2). PMID:27599437

  17. Effect of GaAIAs low-level laser therapy on the healing of human palate mucosa after connective tissue graft harvesting: randomized clinical trial.

    PubMed

    Dias, Stephanie Botti Fernanandes; Fonseca, Marcus Vinícius Alves; Dos Santos, Nídia Cristina Castro; Mathias, Ingrid Fernandes; Martinho, Frederico Canato; Junior, Milton Santamaria; Jardini, Maria Aparecida Neves; Santamaria, Mauro Pedrine

    2015-08-01

    Among the available techniques to treat gingival recession, connective tissue graft (CTG) presents more foreseeability and better results in the long term. However, this technique causes morbidity and discomfort in the palatine region due to graft removal at that site. The aim of this clinical trial was to evaluate the influence of low-level laser therapy (LLLT) on the healing of the donor palatine area after CTG. Thirty-two patients presenting buccal gingival recession were selected and randomly assigned to receive LLLT irradiation (test group) or LLLT sham (control group) in the palatine area after connective graft removal. A diode laser (AsGaAl, 660 nm) was applied to test the sites immediately after surgery and every other day for 7 days. The evaluated parameters were wound remaining area (WRA), scar and tissue colorimetry (TC), tissue thickness (TT), and postoperative discomfort (D). These parameters were evaluated at baseline and 7, 14, 45, 60, and 90 days after surgery. Two-way repeated measures ANOVA was used for analysis. The test group presented statistically significant smaller wounds at days 14 and 45. None of the patients presented a scar at the operated area, and colorimetry analysis revealed that there was no statistically significant difference between groups (p > 0.05). Patients reported mild to moderate discomfort, with low consumption of analgesic pills. We concluded that LLLT irradiation can accelerate wound healing on palatine mucosa after connective tissue removal for root coverage techniques (ClinicalTrial.org NCT02239042).

  18. Effect of insulin-like growth factor-1 and hyaluronic acid in experimentally produced osteochondral defects in rats

    PubMed Central

    Alemdar, Celil; Yücel, İstemi; Erbil, Barış; Erdem, Havva; Atiç, Ramazan; Özkul, Emin

    2016-01-01

    Background: The common purpose of almost all methods used to treat the osteochondral injuries is to produce a normal cartilage matrix. However current methods are not sufficient to provide a normal cartilage matrix. For that reason, researchers have studied to increase the effectiveness of this methods using chondrogenic and chondroprotective molecules in recent experimental studies. Insulin-like growth factor-1 (IGF-1) and hyaluronic acid (HA) are two important agents used in this field. This study compared the effects of IGF-1 and HA in an experimental osteochondral defect in rat femora. Materials and Methods: The rats were divided into three groups (n = 15 per group) as follows: The IGF-1 group, HA group, and control group. An osteochondral defect of a diameter of 1.5 mm and a depth of 2 mm was created on the patellar joint side of femoral condyles. The IGF-1 group received an absorbable gelatin sponge soaked with 15 μg/15 μl of IGF-1, and the HA group received an absorbable gelatin sponge soaked with 80 μg HA. The control group received only an absorbable gelatin sponge. Rats were sacrificed at the 6th week, and the femur condyles were evaluated histologically. Results: According to the total Mankin scale, there was a statistically significant difference between IGF-1 and HA groups and between IGF-1 and control groups. There was also a significant statistical difference between HA and control groups. Conclusion: It was shown histopathologically that IGF-1 is an effective molecule for osteochondral lesions. Although it is weaker than IGF-1, HA also strengthened the repair tissue. PMID:27512224

  19. Delayed skin grafting.

    PubMed

    Ceilley, R I; Bumsted, R M; Panje, W R

    1983-04-01

    The use of skin grafts on granulating wounds is an established practice. Delaying the application of a full- or split-thickness skin graft may be an advantageous alternative method of surgical reconstruction in selected cases. Partial healing by secondary intention is useful for filling in deeper defects and usually produces a wound that is much smaller and of more normal contour than the original defect. Contraction of the graft bed is markedly influenced by location, tissue laxity, surface tension lines, motion, and wound geometry. Proper wound care, correct surgical preparation of the defect, and timing of the graft procedure are all important considerations in maximizing the overall result. Through-and-through defects and wounds produced over areas with little underlying support (eyelids and lip) often need flap reconstruction or immediate grafting to prevent undesirable functional and cosmetic results. By combining delayed healing and conventional reconstructive techniques, major tissue loss can often be restored while minimizing patient morbidity.

  20. Cartilage Repair and Subchondral Bone Migration Using 3D Printing Osteochondral Composites: A One-Year-Period Study in Rabbit Trochlea

    PubMed Central

    Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; He, Jiankang; Jin, Zhongmin

    2014-01-01

    Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a “flow like” manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a “flow like” manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application. PMID:25177697

  1. Cartilage repair and subchondral bone migration using 3D printing osteochondral composites: a one-year-period study in rabbit trochlea.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; He, Jiankang; Jin, Zhongmin

    2014-01-01

    Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a "flow like" manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a "flow like" manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application. PMID:25177697

  2. Cartilage repair and subchondral bone migration using 3D printing osteochondral composites: a one-year-period study in rabbit trochlea.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; He, Jiankang; Jin, Zhongmin

    2014-01-01

    Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a "flow like" manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a "flow like" manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application.

  3. Stem cell origin differently affects bone tissue engineering strategies

    PubMed Central

    Mattioli-Belmonte, Monica; Teti, Gabriella; Salvatore, Viviana; Focaroli, Stefano; Orciani, Monia; Dicarlo, Manuela; Fini, Milena; Orsini, Giovanna; Di Primio, Roberto; Falconi, Mirella

    2015-01-01

    Bone tissue engineering approaches are encouraging for the improvement of conventional bone grafting technique drawbacks. Thanks to their self-renewal and multi-lineage differentiation ability, stem cells are one of the major actors in tissue engineering approaches, and among these adult mesenchymal stem cells (MSCs) hold a great promise for regenerative medicine strategies. Bone marrow MSCs (BM-MSCs) are the first- identified and well-recognized stem cell population used in bone tissue engineering. Nevertheless, several factors hamper BM-MSC clinical application and subsequently, new stem cell sources have been investigated for these purposes. The fruitful selection and combination of tissue engineered scaffold, progenitor cells, and physiologic signaling molecules allowed the surgeon to reconstruct the missing natural tissue. On the basis of these considerations, we analyzed the capability of two different scaffolds, planned for osteochondral tissue regeneration, to modulate differentiation of adult stem cells of dissimilar local sources (i.e., periodontal ligament, maxillary periosteum) as well as adipose-derived stem cells (ASCs), in view of possible craniofacial tissue engineering strategies. We demonstrated that cells are differently committed toward the osteoblastic phenotype and therefore, taking into account their specific features, they could be intriguing cell sources in different stem cell-based bone/periodontal tissue regeneration approaches. PMID:26441682

  4. Isolated osteochondral fracture of the metatarsal head of lesser toes.

    PubMed

    Lui, T H

    2015-06-01

    Isolated fracture of the metatarsal head is very rare and no consensus has been reached regarding their best management. We reported four cases of isolated osteochondral fracture of the metatarsal head with different method of treatment to achieve the common goal of restoration of the congruity of the metatarsal head.

  5. OSTEOCHONDRITIS DISSECANS OF THE KNEE: DIAGNOSIS AND TREATMENT

    PubMed Central

    Mestriner, Luiz Aurélio

    2015-01-01

    Osteochondritis dissecans (OCD) is a pathological process affecting the subchondral bone of the knee in children and adolescents with open growth plates (juvenile OCD) and young adults with closed growth plates (adult OCD). It may lead to secondary effects on joint cartilage, such as pain, edema, possible formation of free bodies and mechanical symptoms, including joint locking. OCD may lead to degenerative changes may develop if left untreated. This article presents a review and update on this problem, with special emphasis on diagnosis and treatment. The latter may include either conservative methods, which show more predictable results for juvenile OCD, or various surgical methods, which include reparative techniques like isolated removal of the fragment, bone drilling and fixation of the osteochondral fragments, and restorative techniques like microfractures, autologous osteochondral transplantation (mosaicplasty), autologous chondrocyte implantation and fresh osteochondral allograft, depending on lesion stability, lesion viability, skeletal maturity and OCD process location. Recent assessments on the results from several types of treatment have shown that there is a lack of studies with reliable levels of evidence and have suggested that further multicenter prospective randomized and controlled studies on management of this disease should be conducted. PMID:27047865

  6. Osteochondritis dissecans affecting the temporo-mandibular joint.

    PubMed

    Olley, S F; Leopard, P J

    1978-07-01

    A case of a single loose body occurring in the temporo-mandibular joint is described. It is probable that this case represents the degenerative process of osteochondritis dissecans, a condition not previously described in this joint. The essential features of this condition are noted as a comparison to the condition of synovial chondromatosis.

  7. Biomaterials for Tissue Engineering

    PubMed Central

    Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

    2013-01-01

    Biomaterials serve as an integral component of tissue engineering. They are designed to provide architectural framework reminiscent of native extracellular matrix in order to encourage cell growth and eventual tissue regeneration. Bone and cartilage represent two distinct tissues with varying compositional and mechanical properties. Despite these differences, both meet at the osteochondral interface. This article presents an overview of current biomaterials employed in bone and cartilage applications, discusses some design considerations, and alludes to future prospects within this field of research. PMID:23820768

  8. Repair of articular osteochondral defects of the knee joint using a composite lamellar scaffold

    PubMed Central

    Lv, Y. M.; Yu, Q. S.

    2015-01-01

    Objectives The major problem with repair of an articular cartilage injury is the extensive difference in the structure and function of regenerated, compared with normal cartilage. Our work investigates the feasibility of repairing articular osteochondral defects in the canine knee joint using a composite lamellar scaffold of nano-ß-tricalcium phosphate (ß-TCP)/collagen (col) I and II with bone marrow stromal stem cells (BMSCs) and assesses its biological compatibility. Methods The bone–cartilage scaffold was prepared as a laminated composite, using hydroxyapatite nanoparticles (nano-HAP)/collagen I/copolymer of polylactic acid–hydroxyacetic acid as the bony scaffold, and sodium hyaluronate/poly(lactic-co-glycolic acid) as the cartilaginous scaffold. Ten-to 12-month-old hybrid canines were randomly divided into an experimental group and a control group. BMSCs were obtained from the iliac crest of each animal, and only those of the third generation were used in experiments. An articular osteochondral defect was created in the right knee of dogs in both groups. Those in the experimental group were treated by implanting the composites consisting of the lamellar scaffold of ß-TCP/col I/col II/BMSCs. Those in the control group were left untreated. Results After 12 weeks of implantation, defects in the experimental group were filled with white semi-translucent tissue, protruding slightly over the peripheral cartilage surface. After 24 weeks, the defect space in the experimental group was filled with new cartilage tissues, finely integrated into surrounding normal cartilage. The lamellar scaffold of ß-TCP/col I/col II was gradually degraded and absorbed, while new cartilage tissue formed. In the control group, the defects were not repaired. Conclusion This method can be used as a suitable scaffold material for the tissue-engineered repair of articular cartilage defects. Cite this article: Bone Joint Res 2015;4:56–64 PMID:25837672

  9. Fate of bone marrow mesenchymal stem cells following the allogeneic transplantation of cartilaginous aggregates into osteochondral defects of rabbits.

    PubMed

    Yoshioka, Tomokazu; Mishima, Hajime; Kaul, Zeenia; Ohyabu, Yoshimi; Sakai, Shinsuke; Ochiai, Naoyuki; Kaul, Sunil C; Wadhwa, Renu; Uemura, Toshimasa

    2011-06-01

    The purpose of this study was to track mesenchymal stem cells (MSCs) labelled with internalizing quantum dots (i-QDs) in the reparative tissues, following the allogeneic transplantation of three-dimensional (3D) cartilaginous aggregates into the osteochondral defects of rabbits. QDs were conjugated with a unique internalizing antibody against a heat shock protein-70 (hsp70) family stress chaperone, mortalin, which is upregulated and expressed on the surface of dividing cells. The i-QDs were added to the culture medium for 24 h. Scaffold-free cartilaginous aggregates formed from i-QD-labelled MSCs (i-MSCs), using a 3D culture system with chondrogenic supplements for 1 week, were transplanted into osteochondral defects of rabbits. At 4, 8 and 26 weeks after the transplantation, the reparative tissues were evaluated macroscopically, histologically and fluoroscopically. At as early as 4 weeks, the defects were covered with a white tissue resembling articular cartilage. In histological appearance, the reparative tissues resembled hyaline cartilage on safranin-O staining throughout the 26 weeks. In the deeper portion, subchondral bone and bone marrow were well remodelled. On fluoroscopic evaluation, QDs were tracked mainly in bone marrow stromata, with some signals detected in cartilage and the subchondral bone layer. We showed that the labelling of rabbit MSCs with anti-mortalin antibody-conjugated i-QDs is a tolerable procedure and provides a stable fluorescence signal during the cartilage repair process for up to 26 weeks after transplantation. The results suggest that i-MSCs did not inhibit, and indeed contributed to, the regeneration of osteochondral defects.

  10. Modified autologous matrix-induced chondrogenesis (AMIC) for the treatment of a large osteochondral defect in a varus knee: a case report.

    PubMed

    de Girolamo, L; Quaglia, A; Bait, C; Cervellin, M; Prospero, E; Volpi, P

    2012-11-01

    This paper presents a case report of a 27-year-old male patient affected by a large osteochondral defect of the medial femoral condyle (6 cm(2)) in a varus knee. He was treated with a combined approach consisting of high tibial osteotomy and autologous matrix-induced chondrogenesis technique enhanced by a bone marrow-enriched bone graft. Twelve months after surgery, the patient reported considerable reduction in pain and significant increase in his quality of life. A hyaline-like cartilage completely covered the defect and was congruent with the surrounding condyle cartilage as revealed by MRI and by a second-look arthroscopy. Level of evidence IV.

  11. Transmucosal Implant Placement with Submarginal Connective Tissue Graft in Area of Shallow Buccal Bone Dehiscence: A Three-Year Follow-Up Case Series.

    PubMed

    Stefanini, Martina; Felice, Pietro; Mazzotti, Claudio; Marzadori, Matteo; Gherlone, Enrico F; Zucchelli, Giovanni

    2016-01-01

    The aim of the present case series study was to evaluate the short- and long-term (3 years) soft tissue stability of a surgical technique combining transmucosal implant placement with submarginal connective tissue graft (CTG) in an area of shallow buccal bone dehiscence. A sample of 20 patients were treated by positioning a transmucosal implant in an intercalated edentulous area. A CTG sutured to the inner aspect of the buccal flap was used to cover the shallow buccal bone dehiscence. Clinical evaluations were made at 6 months (T₁) and 1 (T₂) and 3 (T₃) years after the surgery. Statistically significant increases in buccal soft tissue thickness and improvement of vertical soft tissue level were achieved at the T₁, T₂, and T₃ follow-ups. A significant increase in keratinized tissue height was also found at T₃. No significant marginal bone loss was recorded. The submarginal CTG technique was able to provide simultaneous vertical and horizontal soft tissue increases around single implants with shallow buccal bone dehiscence and no buccal mucosal recession or clinical signs of mucositis or peri-implantitis at 1 and 3 years. PMID:27560667

  12. In Vivo Functional Evaluation of Tissue-Engineered Vascular Grafts Fabricated Using Human Adipose-Derived Stem Cells from High Cardiovascular Risk Populations.

    PubMed

    Krawiec, Jeffrey T; Weinbaum, Justin S; Liao, Han-Tsung; Ramaswamy, Aneesh K; Pezzone, Dominic J; Josowitz, Alexander D; D'Amore, Antonio; Rubin, J Peter; Wagner, William R; Vorp, David A

    2016-05-01

    Many preclinical evaluations of autologous small-diameter tissue-engineered vascular grafts (TEVGs) utilize cells from healthy humans or animals. However, these models hold minimal relevance for clinical translation, as the main targeted demographic is patients at high cardiovascular risk such as individuals with diabetes mellitus or the elderly. Stem cells such as adipose-derived mesenchymal stem cells (AD-MSCs) represent a clinically ideal cell type for TEVGs, as these can be easily and plentifully harvested and offer regenerative potential. To understand whether AD-MSCs sourced from diabetic and elderly donors are as effective as those from young nondiabetics (i.e., healthy) in the context of TEVG therapy, we implanted TEVGs constructed with human AD-MSCs from each donor type as an aortic interposition graft in a rat model. The key failure mechanism observed was thrombosis, and this was most prevalent in grafts using cells from diabetic patients. The remainder of the TEVGs was able to generate robust vascular-like tissue consisting of smooth muscle cells, endothelial cells, collagen, and elastin. We further investigated a potential mechanism for the thrombotic failure of AD-MSCs from diabetic donors; we found that these cells have a diminished potential to promote fibrinolysis compared to those from healthy donors. Together, this study served as proof of concept for the development of a TEVG based on human AD-MSCs, illustrated the importance of testing cells from realistic patient populations, and highlighted one possible mechanistic explanation as to the observed thrombotic failure of our diabetic AD-MSC-based TEVGs. PMID:27079751

  13. c-Kit+ progenitors generate vascular cells for tissue-engineered grafts through modulation of the Wnt/Klf4 pathway

    PubMed Central

    Campagnolo, Paola; Tsai, Tsung-Neng; Hong, Xuechong; Kirton, John Paul; So, Po-Wah; Margariti, Andriana; Di Bernardini, Elisabetta; Wong, Mei Mei; Hu, Yanhua; Stevens, Molly M.; Xu, Qingbo

    2015-01-01

    The development of decellularised scaffolds for small diameter vascular grafts is hampered by their limited patency, due to the lack of luminal cell coverage by endothelial cells (EC) and to the low tone of the vessel due to absence of a contractile smooth muscle cells (SMC). In this study, we identify a population of vascular progenitor c-Kit+/Sca-1- cells available in large numbers and derived from immuno-privileged embryonic stem cells (ESCs). We also define an efficient and controlled differentiation protocol yielding fully to differentiated ECs and SMCs in sufficient numbers to allow the repopulation of a tissue engineered vascular graft. When seeded ex vivo on a decellularised vessel, c-Kit+/Sca-1-derived cells recapitulated the native vessel structure and upon in vivo implantation in the mouse, markedly reduced neointima formation and mortality, restoring functional vascularisation. We showed that Krüppel-like transcription factor 4 (Klf4) regulates the choice of differentiation pathway of these cells through β-catenin activation and was itself regulated by the canonical Wnt pathway activator lithium chloride. Our data show that ESC-derived c-Kit+/Sca-1-cells can be differentiated through a Klf4/β-catenin dependent pathway and are a suitable source of vascular progenitors for the creation of superior tissue-engineered vessels from decellularised scaffolds. PMID:25985152

  14. Grafting of bovine serum albumin proteins on plasma-modified polymers for potential application in tissue engineering

    NASA Astrophysics Data System (ADS)

    Kasálková, Nikola Slepičková; Slepička, Petr; Kolská, Zdeňka; Hodačová, Petra; Kučková, Štěpánka; Švorčík, Václav

    2014-04-01

    In this work, an influence of bovine serum albumin proteins grafting on the surface properties of plasma-treated polyethylene and poly- l-lactic acid was studied. The interaction of the vascular smooth muscle cells with the modified polymer surface was determined. The surface properties were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, nano-LC-ESI-Q-TOF mass spectrometry, electrokinetic analysis, and goniometry. One of the motivations for this work is the idea that by the interaction of the cell with substrate surface, the proteins will form an interlayer between the cell and the substrate. It was proven that when interacting with the plasma-treated high-density polyethylene and poly- l-lactic acid, the bovine serum albumin protein is grafted on the polymer surface. Since the proteins are bonded to the substrate surface, they can stimulate cell adhesion and proliferation.

  15. Grafting of bovine serum albumin proteins on plasma-modified polymers for potential application in tissue engineering

    PubMed Central

    2014-01-01

    In this work, an influence of bovine serum albumin proteins grafting on the surface properties of plasma-treated polyethylene and poly-l-lactic acid was studied. The interaction of the vascular smooth muscle cells with the modified polymer surface was determined. The surface properties were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, nano-LC-ESI-Q-TOF mass spectrometry, electrokinetic analysis, and goniometry. One of the motivations for this work is the idea that by the interaction of the cell with substrate surface, the proteins will form an interlayer between the cell and the substrate. It was proven that when interacting with the plasma-treated high-density polyethylene and poly-l-lactic acid, the bovine serum albumin protein is grafted on the polymer surface. Since the proteins are bonded to the substrate surface, they can stimulate cell adhesion and proliferation. PMID:24708858

  16. Subepithelial Connective Tissue Graft in Combination with a Tunnel Technique for the Treatment of Miller Class II and III Gingival Recessions in Mandibular Incisors: Clinical and Esthetic Results.

    PubMed

    Nart, Jose; Valles, Cristina

    2016-01-01

    There is limited evidence regarding the effect of the subepithelial connective tissue graft (SCTG) on root coverage in the mandibular anterior region. A sample of 15 Miller Class II and III recessions were treated in 15 patients using a SCTG with a tunnel technique. After a mean follow-up of 20.53 months, the mean percentage of root coverage was 83.25% for all treated recessions. Furthermore, a statistically significant increase of keratinized tissue was observed at the end of the evaluation period (2.66 mm; P = .001). The combination of tunnel technique and SCTG should be considered a treatment option to obtain root coverage in mandibular incisors with Class II and III recession defects. PMID:27333018

  17. Mechanisms of Fat Graft Survival.

    PubMed

    Pu, Lee L Q

    2016-02-01

    Although more fat grafting procedures have been performed by plastic surgeons with the primary goal to restore soft tissue loss, the actual mechanism on how fat graft survives remains less completely understood. An established old theory on fat graft survival is still based on the cell survival theory proposed by Peer in the early 1950s. On the basis of his preliminary experimental study, he proposed that the mechanism of fat graft survival is based on established early blood circulation through anastomosis of the fat graft and host blood vessels. Recently, several investigators have demonstrated new concepts of the fat graft survival: One further advanced the old Peer cell survival theory and another based on new discovery and understanding of adipose-derived stem cells. This article serves as a scientific review on how fat graft survives after in vivo transplantation based on a number of well-conducted experimental studies. Both the graft survival and graft replacement theories on how fat graft survives are true based on the previously mentioned well-conducted experimental studies. Each theory may play a role in fat graft survival. It is possible that graft survival may be more dominant in some patients but the graft replacement may be more dominant in other patients.

  18. The surface grafting of graphene oxide with poly(ethylene glycol) as a reinforcement for poly(lactic acid) nanocomposite scaffolds for potential tissue engineering applications.

    PubMed

    Zhang, Chunmei; Wang, Liwei; Zhai, Tianliang; Wang, Xinchao; Dan, Yi; Turng, Lih-Sheng

    2016-01-01

    Graphene oxide (GO) was incorporated into poly(lactic acid) (PLA) as a reinforcing nanofiller to produce composite nanofibrous scaffolds using the electrospinning technique. To improve the dispersion of GO in PLA and the interfacial adhesion between the filler and matrix, GO was surface-grafted with poly(ethylene glycol) (PEG). Morphological, thermal, mechanical, and wettability properties, as well as preliminary cytocompatibility with Swiss mouse NIH 3T3 cells of PLA, PLA/GO, and PLA/GO-g-PEG electrospun nanofibers, were characterized. Results showed that the average diameter of PLA/GO-g-PEG electrospun nanofibers decreased with filler content. Both GO and GO-g-PEG improved the thermal stability of PLA, but GO-g-PEG was more effective. The water contact angle test of the nanofiber mats showed that the addition of GO in PLA did not change the surface wettability of the materials, but PLA/GO-g-PEG samples exhibited improved wettability with lower water contact angles. The tensile strength of the composite nanofiber mats was improved with the addition of GO, and it was further enhanced when GO was surface grafted with PEG. This suggested that improved interfacial adhesion between GO and PLA was achieved by grafting PEG onto the GO. The cell viability and proliferation results showed that the cytocompatibility of PLA was not compromised with the addition of GO and GO-g-PEG. With enhanced mechanical properties as well as good wettability and cytocompatibility, PLA/GO-g-PEG composite nanofibers have the potential to be used as scaffolds in tissue engineering. PMID:26409231

  19. The surface grafting of graphene oxide with poly(ethylene glycol) as a reinforcement for poly(lactic acid) nanocomposite scaffolds for potential tissue engineering applications.

    PubMed

    Zhang, Chunmei; Wang, Liwei; Zhai, Tianliang; Wang, Xinchao; Dan, Yi; Turng, Lih-Sheng

    2016-01-01

    Graphene oxide (GO) was incorporated into poly(lactic acid) (PLA) as a reinforcing nanofiller to produce composite nanofibrous scaffolds using the electrospinning technique. To improve the dispersion of GO in PLA and the interfacial adhesion between the filler and matrix, GO was surface-grafted with poly(ethylene glycol) (PEG). Morphological, thermal, mechanical, and wettability properties, as well as preliminary cytocompatibility with Swiss mouse NIH 3T3 cells of PLA, PLA/GO, and PLA/GO-g-PEG electrospun nanofibers, were characterized. Results showed that the average diameter of PLA/GO-g-PEG electrospun nanofibers decreased with filler content. Both GO and GO-g-PEG improved the thermal stability of PLA, but GO-g-PEG was more effective. The water contact angle test of the nanofiber mats showed that the addition of GO in PLA did not change the surface wettability of the materials, but PLA/GO-g-PEG samples exhibited improved wettability with lower water contact angles. The tensile strength of the composite nanofiber mats was improved with the addition of GO, and it was further enhanced when GO was surface grafted with PEG. This suggested that improved interfacial adhesion between GO and PLA was achieved by grafting PEG onto the GO. The cell viability and proliferation results showed that the cytocompatibility of PLA was not compromised with the addition of GO and GO-g-PEG. With enhanced mechanical properties as well as good wettability and cytocompatibility, PLA/GO-g-PEG composite nanofibers have the potential to be used as scaffolds in tissue engineering.

  20. A Predictive Factor in Osteochondritis Dissecans

    PubMed Central

    Sikka, Robby Singh; Wechter, John Francis; Alwan, Mujtaba; Tompkins, Marc

    2013-01-01

    Objectives: Knee alignment is thought to have some bearing on the development of osteochondritis dissecans (OCD) lesions.1 The effect of proximal tibial morphology on the risk of OCD, however, is unknown. The purpose of this study was to evaluate proximal tibial morphology and its relationship to OCD lesions. The null hypothesis was that patients with OCD lesions would have no difference in medial and posterior tibial slope when comparing the affected side to the unaffected side and age matched controls. Methods: Using CPT codes, we identified 61 patients with unilateral OCD lesions of the medial femoral condyle seen at our institution from 2005-2010. On plain radiographs, medial tibial slope and posterior tibial slope were assessed by 2 residents and 1 attending. (Figure 1) Measurements were completed on affected, contralateral normal, and control knees. The controls were height, weight, and gender matched. In addition, a comparison was made between OCD patients requiring surgery and those without surgery. Inter-observer reliability for each measurement was determined using intra-class correlation coefficients (ICCs). A student’s t-test was used to compare the results of the affected and normal sides. Results: The average patient age was 15.1 years. There were 31 right-sided lesions and 30 left- sided lesions. Medial tibial slope of the affected knee averaged 67.81 ± 3.92 (ICC(2,1) =.771, p<.01) compared to 69.44 ±3.63 (ICC(2,1) =.785, p<.01) for the normal side (p=.0070). The average posterior tibial slope for the affected knee was 80.03 ± 3.91 (ICC(2,1) =.783, p<.01) and 79.62 ± 4.37 (ICC(2,1) =.844, p<.01) for the normal side (p=.19). Matched controls had an average medial tibial slope 68.73° ± 5.81° (ICC(2,1) =.732, p<.01) which was statistically different from affected knees (p=.043). Matched controls had an average posterior tibial slope 81.13° ± 2.90° (ICC(2,1) =.797, p<.01), which was also statistically different from affected knees (p=.0068

  1. State of the art. Autologous fat graft and adipose tissue-derived stromal vascular fraction injection for hand therapy in systemic sclerosis patients.

    PubMed

    Guillaume-Jugnot, P; Daumas, A; Magalon, J; Sautereau, N; Veran, J; Magalon, G; Sabatier, F; Granel, B

    2016-01-01

    Systemic sclerosis is an autoimmune disease characterized by sclerosis (hardening) of the skin and deep viscera associated with microvascular functional and structural alteration, which leads to chronic ischemia. In the hands of patients, ischemic and fibrotic damages lead to both pain and functional impairment. Hand disability creates a large burden in professional and daily activities, with social and psychological consequences. Currently, the proposed therapeutic options for hands rely mainly on hygienic measures, vasodilatator drugs and physiotherapy, but have many constraints and limited effects. Developing an innovative therapeutic approach is crucial to reduce symptoms and improve the quality of life. The discovery of adult stem cells from adipose tissue has increased the interest to use adipose tissue in plastic and regenerative surgery. Prepared as freshly isolated cells for immediate autologous transplantation, adipose tissue-derived stem cell therapy has emerged as a therapeutic alternative for the regeneration and repair of damaged tissues. We aim to update literature in the interest of autologous fat graft or adipose derived from stromal vascular fraction cell-based therapy for the hands of patients who suffer from systemic sclerosis. PMID:27140597

  2. State of the art. Autologous fat graft and adipose tissue-derived stromal vascular fraction injection for hand therapy in systemic sclerosis patients.

    PubMed

    Guillaume-Jugnot, P; Daumas, A; Magalon, J; Sautereau, N; Veran, J; Magalon, G; Sabatier, F; Granel, B

    2016-01-01

    Systemic sclerosis is an autoimmune disease characterized by sclerosis (hardening) of the skin and deep viscera associated with microvascular functional and structural alteration, which leads to chronic ischemia. In the hands of patients, ischemic and fibrotic damages lead to both pain and functional impairment. Hand disability creates a large burden in professional and daily activities, with social and psychological consequences. Currently, the proposed therapeutic options for hands rely mainly on hygienic measures, vasodilatator drugs and physiotherapy, but have many constraints and limited effects. Developing an innovative therapeutic approach is crucial to reduce symptoms and improve the quality of life. The discovery of adult stem cells from adipose tissue has increased the interest to use adipose tissue in plastic and regenerative surgery. Prepared as freshly isolated cells for immediate autologous transplantation, adipose tissue-derived stem cell therapy has emerged as a therapeutic alternative for the regeneration and repair of damaged tissues. We aim to update literature in the interest of autologous fat graft or adipose derived from stromal vascular fraction cell-based therapy for the hands of patients who suffer from systemic sclerosis.

  3. Fat Grafting for Facial Filling and Regeneration.

    PubMed

    Coleman, Sydney R; Katzel, Evan B

    2015-07-01

    Plastic surgeons have come to realize that fat grafting can rejuvenate an aging face by restoring or creating fullness. However, fat grafting does much more than simply add volume. Grafted fat can transform or repair the tissues into which it is placed. Historically, surgeons have hesitated to embrace the rejuvenating potential of fat grafting because of poor graft take, fat necrosis, and inconsistent outcomes. This article describes fat grafting techniques and practices to assist readers in successful harvesting, processing, and placement of fat for optimal graft retention and facial esthetic outcomes.

  4. Reengineered graft copolymers as a potential alternative for the bone tissue engineering application by inducing osteogenic markers expression and biocompatibility.

    PubMed

    Thangavelu, Muthukumar; R Narasimha, Raghavan; Adithan, Aravinthan; A, Chandrasekaran; Jong-Hoon, Kim; Thotapalli Parvathaleswara, Sastry

    2016-07-01

    Composite scaffolds of nano-hydroxyapatite with demineralized bone matrix were prepared and they were graft copolymerized for better bone regeneration and drug delivery applications. The graft copolymers were characterized for their physiochemical properties using conventional methods like FTIR, TGA, XRD and SEM. The scaffolds were seeded with 3T3 and MG63 cells for studying their biocompatibility and their temporal expression of ALP activity, the rate of calcium deposition and their gene expression of collagen type I (Coll-1), osteopontin (OP), osteonectin (ON), and osteocalcin (OC) were studied. In vivo studies were conducted using sub-cutaneous implantation models in male Wister rats for 6 months. Periodic radiography and post-autopsy histopathology was analysed at 15days, 1, 2, 3, 4, 5, and 6 months. The obtained in vitro results clearly confirm that the bone scaffolds prepared in this study are biocompatible, superior osteoinductivity, capable of supporting growth, maturation of MG 63 osteoblast like cells; the gene expression profile revealed that the material is capable of supporting the in vitro growth and maturation of osteoblast-like cells and maturation. The in vivo results stand a testimony to the in vitro results in proving the biocompatibility and osteoinductivity of the materials.

  5. Human growth hormone and the development of osteochondritis dissecans lesions.

    PubMed

    Hussain, Waqas M; Hussain, Haroon M; Hussain, Mohammed S; Ho, Sherwin S W

    2011-12-01

    No single etiology regarding the cause of osteochondritis dissecans (OCD) lesions is unanimously accepted. This report documents a novel case of multiple OCD lesions affecting the left knee and a solitary defect of the right elbow in a patient with acquired human growth hormone (hGH) deficiency and supplementation. hGH deficiency and hormone replacement may be related to the development of OCD lesions.

  6. Osteochondral allograft transplantation for treatment of glenohumeral instability.

    PubMed

    Chapovsky, Felix; Kelly, John D

    2005-08-01

    The intimate contact between articular surfaces of the humeral head and glenoid labrum contribute to glenohumeral stability. When the articular surface area of these 2 surfaces is decreased, as with the presence of a bony Bankart lesion or an engaging Hill-Sachs lesion, the shoulder is more prone to dislocation. Although osteochondral allograft transplantation has become widely popular for the treatment of osteochondral defects of the knee, it is less used for treating bony defects of the humeral head. We present a case in which a 16-year-old male athlete with multiple anterior shoulder dislocations underwent arthroscopic repair of a Bankart lesion. His arthroscopic repair ultimately failed and on subsequent magnetic resonance imaging he was found to have a large, engaging Hill-Sachs defect. He underwent arthroscopic osteochondral allograft transplantation to correct the humeral head bony deformity. As of the 1-year follow-up, the patient has had no recurrences and had returned to his normal level of activity.

  7. Tissue-Engineered Small Diameter Arterial Vascular Grafts from Cell-Free Nanofiber PCL/Chitosan Scaffolds in a Sheep Model.

    PubMed

    Fukunishi, Takuma; Best, Cameron A; Sugiura, Tadahisa; Shoji, Toshihiro; Yi, Tai; Udelsman, Brooks; Ohst, Devan; Ong, Chin Siang; Zhang, Huaitao; Shinoka, Toshiharu; Breuer, Christopher K; Johnson, Jed; Hibino, Narutoshi

    2016-01-01

    Tissue engineered vascular grafts (TEVGs) have the potential to overcome the issues faced by existing small diameter prosthetic grafts by providing a biodegradable scaffold where the patient's own cells can engraft and form functional neotissue. However, applying classical approaches to create arterial TEVGs using slow degrading materials with supraphysiological mechanical properties, typically results in limited host cell infiltration, poor remodeling, stenosis, and calcification. The purpose of this study is to evaluate the feasibility of novel small diameter arterial TEVGs created using fast degrading material. A 1.0mm and 5.0mm diameter TEVGs were fabricated with electrospun polycaprolactone (PCL) and chitosan (CS) blend nanofibers. The 1.0mm TEVGs were implanted in mice (n = 3) as an unseeded infrarenal abdominal aorta interposition conduit., The 5.0mm TEVGs were implanted in sheep (n = 6) as an unseeded carotid artery (CA) interposition conduit. Mice were followed with ultrasound and sacrificed at 6 months. All 1.0mm TEVGs remained patent without evidence of thrombosis or aneurysm formation. Based on small animal outcomes, sheep were followed with ultrasound and sacrificed at 6 months for histological and mechanical analysis. There was no aneurysm formation or calcification in the TEVGs. 4 out of 6 grafts (67%) were patent. After 6 months in vivo, 9.1 ± 5.4% remained of the original scaffold. Histological analysis of patent grafts demonstrated deposition of extracellular matrix constituents including elastin and collagen production, as well as endothelialization and organized contractile smooth muscle cells, similar to that of native CA. The mechanical properties of TEVGs were comparable to native CA. There was a significant positive correlation between TEVG wall thickness and CD68+ macrophage infiltration into the scaffold (R2 = 0.95, p = 0.001). The fast degradation of CS in our novel TEVG promoted excellent cellular infiltration and neotissue formation

  8. Tissue-Engineered Small Diameter Arterial Vascular Grafts from Cell-Free Nanofiber PCL/Chitosan Scaffolds in a Sheep Model

    PubMed Central

    Fukunishi, Takuma; Best, Cameron A.; Sugiura, Tadahisa; Shoji, Toshihiro; Yi, Tai; Udelsman, Brooks; Ohst, Devan; Ong, Chin Siang; Zhang, Huaitao; Shinoka, Toshiharu; Breuer, Christopher K.; Johnson, Jed; Hibino, Narutoshi

    2016-01-01

    Tissue engineered vascular grafts (TEVGs) have the potential to overcome the issues faced by existing small diameter prosthetic grafts by providing a biodegradable scaffold where the patient’s own cells can engraft and form functional neotissue. However, applying classical approaches to create arterial TEVGs using slow degrading materials with supraphysiological mechanical properties, typically results in limited host cell infiltration, poor remodeling, stenosis, and calcification. The purpose of this study is to evaluate the feasibility of novel small diameter arterial TEVGs created using fast degrading material. A 1.0mm and 5.0mm diameter TEVGs were fabricated with electrospun polycaprolactone (PCL) and chitosan (CS) blend nanofibers. The 1.0mm TEVGs were implanted in mice (n = 3) as an unseeded infrarenal abdominal aorta interposition conduit., The 5.0mm TEVGs were implanted in sheep (n = 6) as an unseeded carotid artery (CA) interposition conduit. Mice were followed with ultrasound and sacrificed at 6 months. All 1.0mm TEVGs remained patent without evidence of thrombosis or aneurysm formation. Based on small animal outcomes, sheep were followed with ultrasound and sacrificed at 6 months for histological and mechanical analysis. There was no aneurysm formation or calcification in the TEVGs. 4 out of 6 grafts (67%) were patent. After 6 months in vivo, 9.1 ± 5.4% remained of the original scaffold. Histological analysis of patent grafts demonstrated deposition of extracellular matrix constituents including elastin and collagen production, as well as endothelialization and organized contractile smooth muscle cells, similar to that of native CA. The mechanical properties of TEVGs were comparable to native CA. There was a significant positive correlation between TEVG wall thickness and CD68+ macrophage infiltration into the scaffold (R2 = 0.95, p = 0.001). The fast degradation of CS in our novel TEVG promoted excellent cellular infiltration and neotissue formation

  9. The use of osteochondral allograft with bone marrow-derived mesenchymal cells and hinge joint distraction in the treatment of post-collapse stage of osteonecrosis of the femoral head.

    PubMed

    Gagala, J; Tarczynska, M; Gaweda, K; Matuszewski, L

    2014-09-01

    Osteonecrosis of the femoral head is an entity which occurs mainly in young and active patients aged between 20 and 50. The success of hip joint preserving treatments ranges from 15% to 50% depending on the stage and amount of osteonecrotic lesion. Total hip replacement is indicated in late post-collapse hips but it has unsatisfactory survival because of the wear and osteolysis in young and active patients. Osteochondral allografts have been reported in the treatment of large articular lesions with defects in underlying bone in knee, talus and shoulder. By combining osteoconductive properties of osteochondral allograft with osteogenic abilities of bone marrow-derived mesenchymal cells it has a potential to be an alternative to an autologous graft. The adjunct of hinged joint distraction should minimize stresses in subchondral bone to promote creeping substitution and prevent femoral head collapse. Unlike current treatment modalities, it would provide both structural support and allow bony and articular substitution.

  10. Evaluation of biomarkers following autologous osteochondral transplantation in the equine stifle joint - An experimental study.

    PubMed

    Tuska, Pál; Tóth, Balázs; Vásárhelyi, Gábor; Hangody, László; Papp, Miklós; Bodó, Gábor

    2016-06-01

    The purpose of this study was to evaluate changes in biomarker and synovial parameters following autologous osteochondral transplantation (AOT) in the equine stifle joint, to test the hypothesis whether synovial parameters would show significant differences at selected time points following the surgery (at days 3, 14, 60 and 180) compared to baseline level (at day 0). Surgical intervention was performed in both stifles of nine horses (n = 18). The joints were randomly assigned to operated and sham-operated groups. Grafts 8.5 mm in diameter were harvested from the femoropatellar (FP) joint under arthroscopic control and the medial femorotibial (MFT) joints had AOT using mosaicplasty (MP) instrumentation, while the sham FP and sham MFT joints underwent arthroscopy and miniarthrotomy without transplantation, respectively. Synovial fluid (SF) parameters were evaluated at days 4, 14, 60 and 180. Data were analysed by two-way repeated- measures analysis of variance (ANOVA), and P < 0.05 was considered significant. During the first 10-14 days after surgery, lameness of degree 2-3/5 [American Association of Equine Practitioners (AAEP) scores] was present, which disappeared after 60 days. Joints with transplantation showed significant increases in synovial white blood cell count (WBC), total protein (TP), substance P, C1,2C and CS846 epitope concentration at day 3 compared to baseline and shamoperated joints (P < 0.05). These parameters returned to the baseline values by two months after surgery and remained within normal levels at 6 months postoperatively. PMID:27342088

  11. Osteochondritis dissecans of the capitellum: a review of the literature and a distal ulnar portal.

    PubMed

    van den Ende, Kimberly I M; McIntosh, Amy L; Adams, Julie E; Steinmann, Scott P

    2011-01-01

    Osteochondritis dissecans (OCD) of the humeral capitellum most commonly affects young athletes engaged in sports that repetitively stress the elbow. It is characterized by localized injury of subchondral bone of the humeral capitellum. To determine the best treatment option for OCD in young athletes, it is important to differentiate between stable and unstable OCD lesions. Stable lesions can be treated with rest, whereas unstable lesions, as well stable lesions that do not respond to conservative therapy, may require a surgical approach. Magnetic resonance imaging is the diagnostic study of choice to evaluate capitellar OCD lesions and loose bodies and to accurately determine the stability and viability of the OCD fragment. A variety of surgical approaches have been reported, from internal fixation of large fragments to autologous chondrocyte grafts. Arthroscopic surgery is becoming the standard treatment of capitellar OCD. This minimally invasive approach shows good results, a low risk of operative morbidity, and early recuperation postoperatively. The distal ulnar portal we describe here allows for ergonomic exposure to the posterolateral capitellum, providing easier access for drilling, burring, and local debridement of lesions amenable to arthroscopy.

  12. Time-dependent bladder tissue regeneration using bilayer bladder acellular matrix graft-silk fibroin scaffolds in a rat bladder augmentation model.

    PubMed

    Zhao, Yang; He, Yi; Zhou, Zhe; Guo, Jian-hua; Wu, Jia-sheng; Zhang, Ming; Li, Wei; Zhou, Juan; Xiao, Dong-dong; Wang, Zhong; Sun, Kang; Zhu, Ying-jian; Lu, Mu-jun

    2015-09-01

    With advances in tissue engineering, various synthetic and natural biomaterials have been widely used in tissue regeneration of the urinary bladder in rat models. However, reconstructive procedures remain insufficient due to the lack of appropriate scaffolding, which should provide a waterproof barrier function and support the needs of various cell types. To address these problems, we have developed a bilayer scaffold comprising a porous network (silk fibroin [SF]) and an underlying natural acellular matrix (bladder acellular matrix graft [BAMG]) and evaluated its feasibility and potential for bladder regeneration in a rat bladder augmentation model. Histological (hematoxylin and eosin and Masson's trichrome staining) and immunohistochemical analyses demonstrated that the bilayer BAMG-SF scaffold promoted smooth muscle, blood vessel, and nerve regeneration in a time-dependent manner. At 12weeks after implantation, bladders reconstructed with the BAMG-SF matrix displayed superior structural and functional properties without significant local tissue responses or systemic toxicity. These results demonstrated that the bilayer BAMG-SF scaffold may be a promising scaffold with good biocompatibility for bladder regeneration in the rat bladder augmentation model.

  13. In vitro fabrication of autologous living tissue-engineered vascular grafts based on prenatally harvested ovine amniotic fluid-derived stem cells.

    PubMed

    Weber, Benedikt; Kehl, Debora; Bleul, Ulrich; Behr, Luc; Sammut, Sébastien; Frese, Laura; Ksiazek, Agnieszka; Achermann, Josef; Stranzinger, Gerald; Robert, Jérôme; Sanders, Bart; Sidler, Michele; Brokopp, Chad E; Proulx, Steven T; Frauenfelder, Thomas; Schoenauer, Roman; Emmert, Maximilian Y; Falk, Volkmar; Hoerstrup, Simon P

    2016-01-01

    Amniotic fluid cells (AFCs) have been proposed as a valuable source for tissue engineering and regenerative medicine. However, before clinical implementation, rigorous evaluation of this cell source in clinically relevant animal models accepted by regulatory authorities is indispensable. Today, the ovine model represents one of the most accepted preclinical animal models, in particular for cardiovascular applications. Here, we investigate the isolation and use of autologous ovine AFCs as cell source for cardiovascular tissue engineering applications. Fetal fluids were aspirated in vivo from pregnant ewes (n = 9) and from explanted uteri post mortem at different gestational ages (n = 91). Amniotic non-allantoic fluid nature was evaluated biochemically and in vivo samples were compared with post mortem reference samples. Isolated cells revealed an immunohistochemical phenotype similar to ovine bone marrow-derived mesenchymal stem cells (MSCs) and showed expression of stem cell factors described for embryonic stem cells, such as NANOG and STAT-3. Isolated ovine amniotic fluid-derived MSCs were screened for numeric chromosomal aberrations and successfully differentiated into several mesodermal phenotypes. Myofibroblastic ovine AFC lineages were then successfully used for the in vitro fabrication of small- and large-diameter tissue-engineered vascular grafts (n = 10) and cardiovascular patches (n = 34), laying the foundation for the use of this relevant pre-clinical in vivo assessment model for future amniotic fluid cell-based therapeutic applications.

  14. Time-dependent bladder tissue regeneration using bilayer bladder acellular matrix graft-silk fibroin scaffolds in a rat bladder augmentation model.

    PubMed

    Zhao, Yang; He, Yi; Zhou, Zhe; Guo, Jian-hua; Wu, Jia-sheng; Zhang, Ming; Li, Wei; Zhou, Juan; Xiao, Dong-dong; Wang, Zhong; Sun, Kang; Zhu, Ying-jian; Lu, Mu-jun

    2015-09-01

    With advances in tissue engineering, various synthetic and natural biomaterials have been widely used in tissue regeneration of the urinary bladder in rat models. However, reconstructive procedures remain insufficient due to the lack of appropriate scaffolding, which should provide a waterproof barrier function and support the needs of various cell types. To address these problems, we have developed a bilayer scaffold comprising a porous network (silk fibroin [SF]) and an underlying natural acellular matrix (bladder acellular matrix graft [BAMG]) and evaluated its feasibility and potential for bladder regeneration in a rat bladder augmentation model. Histological (hematoxylin and eosin and Masson's trichrome staining) and immunohistochemical analyses demonstrated that the bilayer BAMG-SF scaffold promoted smooth muscle, blood vessel, and nerve regeneration in a time-dependent manner. At 12weeks after implantation, bladders reconstructed with the BAMG-SF matrix displayed superior structural and functional properties without significant local tissue responses or systemic toxicity. These results demonstrated that the bilayer BAMG-SF scaffold may be a promising scaffold with good biocompatibility for bladder regeneration in the rat bladder augmentation model. PMID:26049152

  15. Epicardial and Subcutaneous Adipose Tissue Fatty Acids Profiles in Diabetic and Non-Diabetic Patients Candidate for Coronary Artery Bypass Graft

    PubMed Central

    Pezeshkian, Masood; Mahtabipour, Mohammad-Reza

    2013-01-01

    Introduction: We have recently shown that in high cholesterol-fed rabbits, the sensitivity of epicardial adipose tissue to changes in dietary fat is higher than that of subcutaneous adipose tissue. Although the effects of diabetes on epicardial adipose tissue thickness have been studied, the influence of diabetes on profile of epicardial free fatty acids (FFAs) has not been studied. The aim of this study is to investigate the effect of diabetes on the FFAs composition in serum and in the subcutaneous and epicardial adipose tissues in patients undergoing coronary artery bypass graft (CABG). Methods: Forty non-diabetic and twenty eight diabetic patients candidate for CABG with >75% stenosis participated in this study. Fasting blood sugar (FBS) and lipid profiles were assayed by auto analyzer. Phospholipids and non-estrified FFA of serum and the fatty acids profile of epicardial and subcutaneous adipose tissues were determined using gas chromatography method. Results: In the phospholipid fraction of diabetic patients’ serum, the percentage of 16:0, 18:3n-9, 18:2n-6 and monounsaturated fatty acids (MUFAs) was lower than the corresponding values of the non-diabetics; whereas, 18:0 value was higher. A 100% increase in the amount of 18:0 and 35% decrease in the level of 18:1n-11 was observed in the diabetic patients’ subcutaneous adipose tissue. In epicardial adipose tissue, the increase of 18:0 and conjugated linolenic acid (CLA) and decrease of 18:1n-11, w3 (20:5n-3) and 22:6n-3 were significant; but, the contents of arachidonic acid and its precursor linoleic acid were not affected by diabetes. Conclusion: The fatty acids’ profile of epicardial and subcutaneous adipose tissues is not equally affected by diabetes. The significant decrease of 16:0 and w3 fatty acids and increase of trans and conjugated fatty acids in epicardial adipose tissue in the diabetic patients may worsen the formation of atheroma in the related arteries. PMID:23878791

  16. Osteochondritis dissecans and Osgood Schlatter disease in a family with Stickler syndrome

    PubMed Central

    Al Kaissi, Ali; Klaushofer, Klaus; Grill, Franz

    2009-01-01

    Purpose Stickler syndrome is among the most common autosomal dominant connective tissue disorders but is often unrecognised and therefore not diagnosed by clinicians. Despite much speculation, the cause of osteochondrosis in general and osteochondritis dissecans (OCD) and Osgood Schlatter syndrome (OSS) in particular remain unclear. Etiological understanding is essential. We describe a pair of family subjects presented with OCD and OSS as a symptom complex rather than a diagnosis. Methods Detailed clinical and radiographic examinations were undertaken with emphasis on the role of MRI imaging. Magnetic resonance imaging may allow early prediction of articular lesion healing potential in patients with Stickler syndrome. Results The phenotype of Stickler syndrome can be diverse and therefore misleading. The expectation that the full clinical criteria of any given genetic disorder such as Stickler syndrome will always be present can easily lead to an underestimation of these serious inheritable disorders. We report here two family subjects, a male proband and his aunt (paternal sister), both presented with the major features of Stickler syndrome. Tall stature with marfanoid habitus, astigmatism/congenital vitreous abnormality and submucus cleft palate/cleft uvula, and enlarged painful joints with early onset osteoarthritis. Osteochondritis dissecans (OCD) and Osgood Schlatter syndrome (OSS) were the predominating joint abnormalities. Conclusion We observed that the nature of the articular and physeal abnormalities was consistent with a localised manifestation of a more generalised epiphyseal dysplasia affecting the weight-bearing joints. In these two patients, OCD and OSS appeared to be the predominant pathologic musculoskeletal consequences of an underlying Stickler's syndrome. It is empirical to consider generalised epiphyseal dysplasia as a major underlying causation that might drastically affect the weight-bearing joints. PMID:19193224

  17. Xenoimplantation of an Extracellular-Matrix-Derived, Biphasic, Cell-Scaffold Construct for Repairing a Large Femoral-Head High-Load-Bearing Osteochondral Defect in a Canine Model

    PubMed Central

    Qiang, Yang; Yanhong, Zhao; Jiang, Peng; Shibi, Lu; Quanyi, Guo; Xinlong, Ma; Qun, Xia; Baoshan, Xu; Bin, Zhao; Aiyuan, Wang; Li, Zhang; Wengjing, Xu; Chao, Zeng

    2014-01-01

    This study was aimed to develop an ECM-derived biphasic scaffold and to investigate its regeneration potential loaded with BM-MSCs in repair of large, high-load-bearing osteochondral defects of the canine femoral head. The scaffolds were fabricated using cartilage and bone ECM as a cartilage and bone layer, respectively. Osteochondral constructs were fabricated using induced BM-MSCs and the scaffold. Osteochondral defects (11 mm diameter × 10 mm depth) were created on femoral heads of canine and treated with the constructs. The repaired tissue was evaluated for gross morphology, radiography, histological, biomechanics at 3 and 6 months after implantation. Radiography revealed that femoral heads slightly collapsed at 3 months and severely collapsed at 6 months. Histology revealed that some defects in femoral heads were repaired, but with fibrous tissue or fibrocartilage, and femoral heads with different degrees of collapse. The bone volume fraction was lower for subchondral bone than normal femoral bone at 3 and 6 months. Rigidity was lower in repaired subchondral bone than normal femoral bone at 6 months. The ECM-derived, biphasic scaffold combined with induced BM-MSCs did not successfully repair large, high-load-bearing osteochondral defects of the canine femoral head. However, the experience can help improve the technique of scaffold fabrication and vascularization. PMID:24737955

  18. Plant grafting.

    PubMed

    Melnyk, Charles W; Meyerowitz, Elliot M

    2015-03-01

    Since ancient times, people have cut and joined together plants of different varieties or species so they would grow as a single plant - a process known as grafting (Figures 1 and 2). References to grafting appear in the Bible, ancient Greek and ancient Chinese texts, indicating that grafting was practised in Europe, the Middle East and Asia by at least the 5(th) century BCE. It is unknown where or how grafting was first discovered, but it is likely that natural grafting, the process by which two plants touch and fuse limbs or roots in the absence of human interference (Figure 3), influenced people's thinking. Such natural grafts are generally uncommon, but are seen in certain species, including English ivy. Parasitic plants, such as mistletoe, that grow and feed on often unrelated species may have also contributed to the development of grafting as a technique, as people would have observed mistletoe growing on trees such as apples or poplars. PMID:25734263

  19. All-Arthroscopic Autologous Matrix-Induced Chondrogenesis for the Treatment of Osteochondral Lesions of the Talus

    PubMed Central

    Usuelli, Federico Giuseppe; de Girolamo, Laura; Grassi, Miriam; D'Ambrosi, Riccardo; Montrasio, Umberto Alfieri; Boga, Michele

    2015-01-01

    Several surgical techniques have been described for the treatment of talar chondral lesions. Among them, microfracture is well established. Autologous matrix-induced chondrogenesis (AMIC), using microfracture and biomaterials, has shown promising results for the treatment of knee osteochondral lesions and has been proposed for the ankle as an open technique. We describe an all-arthroscopic AMIC technique. The benefits of an all-arthroscopic procedure include smaller incisions with less soft-tissue dissection, better visualization of the joint, and a quicker recovery compared with open surgery. The use of matrix to support cartilage regeneration promotes good-quality cartilage tissue with satisfactory long-term outcomes. Our all-arthroscopic AMIC technique uses a type I–type III porcine collagen matrix (Chondro-Gide; Geistlich Pharma, Wolhusen, Switzerland) and is characterized by 2 different arthroscopic surgical phases. First, adequate exposure is achieved through use of a Hintermann spreader (Integra LifeSciences, Plainsboro, NJ) with sufficient joint distraction and wet lesion preparation. The second surgical step is performed dry, involving matrix placement and fixation. The all-arthroscopic AMIC technique for the treatment of osteochondral lesions of the talus allows a very precise reconstruction in the case of cartilage defects and avoids the need for a more invasive operation associated with higher morbidity and a longer surgical time. PMID:26258040

  20. All-Arthroscopic Autologous Matrix-Induced Chondrogenesis for the Treatment of Osteochondral Lesions of the Talus.

    PubMed

    Usuelli, Federico Giuseppe; de Girolamo, Laura; Grassi, Miriam; D'Ambrosi, Riccardo; Montrasio, Umberto Alfieri; Boga, Michele

    2015-06-01

    Several surgical techniques have been described for the treatment of talar chondral lesions. Among them, microfracture is well established. Autologous matrix-induced chondrogenesis (AMIC), using microfracture and biomaterials, has shown promising results for the treatment of knee osteochondral lesions and has been proposed for the ankle as an open technique. We describe an all-arthroscopic AMIC technique. The benefits of an all-arthroscopic procedure include smaller incisions with less soft-tissue dissection, better visualization of the joint, and a quicker recovery compared with open surgery. The use of matrix to support cartilage regeneration promotes good-quality cartilage tissue with satisfactory long-term outcomes. Our all-arthroscopic AMIC technique uses a type I-type III porcine collagen matrix (Chondro-Gide; Geistlich Pharma, Wolhusen, Switzerland) and is characterized by 2 different arthroscopic surgical phases. First, adequate exposure is achieved through use of a Hintermann spreader (Integra LifeSciences, Plainsboro, NJ) with sufficient joint distraction and wet lesion preparation. The second surgical step is performed dry, involving matrix placement and fixation. The all-arthroscopic AMIC technique for the treatment of osteochondral lesions of the talus allows a very precise reconstruction in the case of cartilage defects and avoids the need for a more invasive operation associated with higher morbidity and a longer surgical time.

  1. Hybrid Graft Anterior Cruciate Ligament Reconstruction: A Predictable Graft for Knee Stabilization.

    PubMed

    Alvarez-Pinzon, Andres M; Barksdale, Leticia; Krill, Michael K; Leo, Brian M

    2015-06-01

    Trauma to the anterior cruciate ligament (ACL) is a season-ending injury and involves months of activity modification and rehabilitation. The annual incidence of ACL tears in the United States is approximately 200,000, which allows for a broad range of individualized treatment options. Various surgical techniques, including transtibial and independent tunnel drilling, allograft and autograft tissue, and various implants, have been described in the literature. This article describes the indications and technique for a hybrid soft tissue graft for ACL reconstruction. Autologous grafts eliminate the risk of disease transmission and have recently been shown to have a lower rerupture rate, particularly in younger, active patients; however, the harvesting of autologous hamstring grafts carries a risk of donor-site morbidity, iatrogenic injury of the graft, and inadequate graft size. In contrast to a traditional autologous soft tissue graft, the hybrid graft allows for graft size customization for a desired reconstruction, especially in cases where autograft hamstrings may be iatrogenically damaged or of inadequate size when harvested. The goal of a hybrid graft ACL reconstruction is to provide a favorable-sized graft with clinical outcomes comparable with autologous soft tissue grafts. In contrast to a traditional autologous soft tissue graft, this technique provides another option in the event of unforeseen deficiencies or complications associated with harvesting and preparation of the autologous gracilis and semitendinosis soft tissue graft. PMID:26091219

  2. Hybrid Graft Anterior Cruciate Ligament Reconstruction: A Predictable Graft for Knee Stabilization.

    PubMed

    Alvarez-Pinzon, Andres M; Barksdale, Leticia; Krill, Michael K; Leo, Brian M

    2015-06-01

    Trauma to the anterior cruciate ligament (ACL) is a season-ending injury and involves months of activity modification and rehabilitation. The annual incidence of ACL tears in the United States is approximately 200,000, which allows for a broad range of individualized treatment options. Various surgical techniques, including transtibial and independent tunnel drilling, allograft and autograft tissue, and various implants, have been described in the literature. This article describes the indications and technique for a hybrid soft tissue graft for ACL reconstruction. Autologous grafts eliminate the risk of disease transmission and have recently been shown to have a lower rerupture rate, particularly in younger, active patients; however, the harvesting of autologous hamstring grafts carries a risk of donor-site morbidity, iatrogenic injury of the graft, and inadequate graft size. In contrast to a traditional autologous soft tissue graft, the hybrid graft allows for graft size customization for a desired reconstruction, especially in cases where autograft hamstrings may be iatrogenically damaged or of inadequate size when harvested. The goal of a hybrid graft ACL reconstruction is to provide a favorable-sized graft with clinical outcomes comparable with autologous soft tissue grafts. In contrast to a traditional autologous soft tissue graft, this technique provides another option in the event of unforeseen deficiencies or complications associated with harvesting and preparation of the autologous gracilis and semitendinosis soft tissue graft.

  3. Development of an angiogenesis-promoting microvesicle-alginate-polycaprolactone composite graft for bone tissue engineering applications

    PubMed Central

    Zhang, Liming; Lei, Qian; Zhao, Aiqi; Wang, Hongxiang; Li, Qiubai

    2016-01-01

    One of the major challenges of bone tissue engineering applications is to construct a fully vascularized implant that can adapt to hypoxic environments in vivo. The incorporation of proangiogenic factors into scaffolds is a widely accepted method of achieving this goal. Recently, the proangiogenic potential of mesenchymal stem cell-derived microvesicles (MSC-MVs) has been confirmed in several studies. In the present study, we incorporated MSC-MVs into alginate-polycaprolactone (PCL) constructs that had previously been developed for bone tissue engineering applications, with the aim of promoting angiogenesis and bone regeneration. MSC-MVs were first isolated from the supernatant of rat bone marrow-derived MSCs and characterized by scanning electron microscopic, confocal microscopic, and flow cytometric analyses. The proangiogenic potential of MSC-MVs was demonstrated by the stimulation of tube formation of human umbilical vein endothelial cells in vitro. MSC-MVs and osteodifferentiated MSCs were then encapsulated with alginate and seeded onto porous three-dimensional printed PCL scaffolds. When combined with osteodifferentiated MSCs, the MV-alginate-PCL constructs enhanced vessel formation and tissue-engineered bone regeneration in a nude mouse subcutaneous bone formation model, as demonstrated by micro-computed tomographic, histological, and immunohistochemical analyses. This MV-alginate-PCL construct may offer a novel, proangiogenic, and cost-effective option for bone tissue engineering. PMID:27231660

  4. Use of a strontium-enriched calcium phosphate cement in accelerating the healing of soft-tissue tendon graft within the bone tunnel in a rabbit model of anterior cruciate ligament reconstruction.

    PubMed

    Kuang, G M; Yau, W P; Lu, W W; Chiu, K Y

    2013-07-01

    We investigated whether strontium-enriched calcium phosphate cement (Sr-CPC)-treated soft-tissue tendon graft results in accelerated healing within the bone tunnel in reconstruction of the anterior cruciate ligament (ACL). A total of 30 single-bundle ACL reconstructions using tendo Achillis allograft were performed in 15 rabbits. The graft on the tested limb was treated with Sr-CPC, whereas that on the contralateral limb was untreated and served as a control. At timepoints three, six, nine, 12 and 24 weeks after surgery, three animals were killed for histological examination. At six weeks, the graft-bone interface in the control group was filled in with fibrovascular tissue. However, the gap in the Sr-CPC group had already been completely filled in with new bone, and there was evidence of the early formation of Sharpey fibres. At 24 weeks, remodelling into a normal ACL-bone-like insertion was found in the Sr-CPC group. Coating of Sr-CPC on soft tissue tendon allograft leads to accelerated graft healing within the bone tunnel in a rabbit model of ACL reconstruction using Achilles tendon allograft.

  5. [Bone grafts in orthopedic surgery].

    PubMed

    Zárate-Kalfópulos, Barón; Reyes-Sánchez, Alejandro

    2006-01-01

    In orthopedic surgery the demand for the use of bone grafts increases daily because of the increasing quantity and complexity of surgical procedures. At present, the gold standard is the autologous bone graft but the failure rate, morbidity of the donor site and limited availability have stimulated a proliferation for finding materials that work as bone graft substitutes. In order to have good success, we must know the different properties of these choices and the environment where the graft is going to be used. As bone graft substitutes and growth factors become clinical realities, a new gold standard will be defined. Tissue engineering and gene therapy techniques have the objective to create an optimum bone graft substitute with a combination of substances with properties of osteconduction, osteogenesis and osteoinduction. PMID:16875525

  6. [Bone grafts in orthopedic surgery].

    PubMed

    Zárate-Kalfópulos, Barón; Reyes-Sánchez, Alejandro

    2006-01-01

    In orthopedic surgery the demand for the use of bone grafts increases daily because of the increasing quantity and complexity of surgical procedures. At present, the gold standard is the autologous bone graft but the failure rate, morbidity of the donor site and limited availability have stimulated a proliferation for finding materials that work as bone graft substitutes. In order to have good success, we must know the different properties of these choices and the environment where the graft is going to be used. As bone graft substitutes and growth factors become clinical realities, a new gold standard will be defined. Tissue engineering and gene therapy techniques have the objective to create an optimum bone graft substitute with a combination of substances with properties of osteconduction, osteogenesis and osteoinduction.

  7. Isolated slipped-retroverted osteochondral fracture of second metatarsal head.

    PubMed

    Atik, Aziz; Ozyurek, Selahattin; Cicek, Engin Ilker; Kose, Ozkan

    2013-12-01

    Although metatarsal fractures are common, isolated intraarticular metatarsal head fractures are rare, and retroversion of the fracture segment is even rarer. Herein, a retroverted fracture of the second metatarsal head, which happened with a direct trauma from jumping from a height, was discussed with treatment options and finally a simple surgical trick was advised. There are only a few cases of isolated osteochondral and retroverted fractures of the metatarsal head in literature. The following is a rare case report of such an injury in a 19-year-old male.

  8. Osteochondritis dissecans of the elbow: diagnosis, treatment, and prevention.

    PubMed

    Hall, T L; Galea, A M

    1999-02-01

    Osteochondritis dissecans (OCD) is an inflammation of the bone and cartilage that usually affects adolescents and young adults. A 16-year-old baseball player who had chronic elbow pain illustrates the typical course of OCD of the elbow. Radiographs may be diagnostic, but bone scan is a more sensitive diagnostic tool, and magnetic resonance imaging offers information for staging and characterization of lesions. If symptoms do not resolve with rest, surgery is recommended, including loose-body removal with curettage or drilling. The prognosis is good with early diagnosis and treatment. Left untreated, OCD may progress to degenerative joint disease. Prevention includes strengthening and stretching exercises and limits on throwing activities.

  9. Vascular grafting strategies in coronary intervention

    NASA Astrophysics Data System (ADS)

    Knight, Darryl; Gillies, Elizabeth; Mequanint, Kibret

    2014-06-01

    With the growing need for coronary revascularizations globally, several strategies to restore blood flow to the heart have been explored. Bypassing the atherosclerotic coronary arteries with autologous grafts, synthetic prostheses and tissue-engineered vascular grafts continue to be evaluated in search of a readily available vascular graft with clinically acceptable outcomes. The development of such a vascular graft including tissue engineering approaches both in situ and in vitro is herein reviewed, facilitating a detailed comparison on the role of seeded cells in vascular graft patency.

  10. Composite scaffolds for osteochondral repair obtained by combination of additive manufacturing, leaching processes and hMSC-CM functionalization.

    PubMed

    Díaz Lantada, Andrés; Alarcón Iniesta, Hernán; García-Ruíz, Josefa Predestinación

    2016-02-01

    Articular repair is a relevant and challenging area for the emerging fields of tissue engineering and biofabrication. The need of significant gradients of properties, for the promotion of osteochondral repair, has led to the development of several families of composite biomaterials and scaffolds, using different effective approaches, although a perfect solution has not yet been found. In this study we present the design, modeling, rapid manufacturing and in vitro testing of a composite scaffold aimed at osteochondral repair. The presented composite scaffold stands out for having a functional gradient of density and stiffness in the bony phase, obtained in titanium by means of computer-aided design combined with additive manufacture using selective laser sintering. The chondral phase is obtained by sugar leaching, using a PDMS matrix and sugar as porogen, and is joined to the bony phase during the polymerization of PDMS, therefore avoiding the use of supporting adhesives or additional intermediate layers. The mechanical performance of the construct is biomimetic and the stiffness values of the bony and chondral phases can be tuned to the desired applications, by means of controlled modifications of different parameters. A human mesenchymal stem cell (h-MSC) conditioned medium (CM) is used for improving scaffold response. Cell culture results provide relevant information regarding the viability of the composite scaffolds used.

  11. Composite scaffolds for osteochondral repair obtained by combination of additive manufacturing, leaching processes and hMSC-CM functionalization.

    PubMed

    Díaz Lantada, Andrés; Alarcón Iniesta, Hernán; García-Ruíz, Josefa Predestinación

    2016-02-01

    Articular repair is a relevant and challenging area for the emerging fields of tissue engineering and biofabrication. The need of significant gradients of properties, for the promotion of osteochondral repair, has led to the development of several families of composite biomaterials and scaffolds, using different effective approaches, although a perfect solution has not yet been found. In this study we present the design, modeling, rapid manufacturing and in vitro testing of a composite scaffold aimed at osteochondral repair. The presented composite scaffold stands out for having a functional gradient of density and stiffness in the bony phase, obtained in titanium by means of computer-aided design combined with additive manufacture using selective laser sintering. The chondral phase is obtained by sugar leaching, using a PDMS matrix and sugar as porogen, and is joined to the bony phase during the polymerization of PDMS, therefore avoiding the use of supporting adhesives or additional intermediate layers. The mechanical performance of the construct is biomimetic and the stiffness values of the bony and chondral phases can be tuned to the desired applications, by means of controlled modifications of different parameters. A human mesenchymal stem cell (h-MSC) conditioned medium (CM) is used for improving scaffold response. Cell culture results provide relevant information regarding the viability of the composite scaffolds used. PMID:26652367

  12. Spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect created in the femoral condyle using a novel double-network hydrogel

    PubMed Central

    2011-01-01

    Background Functional repair of articular osteochondral defects remains a major challenge not only in the field of knee surgery but also in tissue regeneration medicine. The purpose is to clarify whether the spontaneous hyaline cartilage regeneration can be induced in a large osteochondral defect created in the femoral condyle by means of implanting a novel double-network (DN) gel at the bottom of the defect. Methods Twenty-five mature rabbits were used in this study. In the bilateral knees of each animal, we created an osteochondral defect having a diameter of 2.4-mm in the medial condyle. Then, in 21 rabbits, we implanted a DN gel plug into a right knee defect so that a vacant space of 1.5-mm depth (in Group I), 2.5-mm depth (in Group II), or 3.5-mm depth (in Group III) was left. In the left knee, we did not apply any treatment to the defect to obtain the control data. All the rabbits were sacrificed at 4 weeks, and the gross and histological evaluations were performed. The remaining 4 rabbits underwent the same treatment as used in Group II, and real-time PCR analysis was performed at 4 weeks. Results The defect in Group II was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen. The Wayne's gross appearance and histology scores showed that Group II was significantly greater than Group I, III, and Control (p < 0.012). The relative expression level of type-2 collagen, aggrecan, and SOX9 mRNAs was significantly greater in Group II than in the control group (p < 0.023). Conclusions This study demonstrated that spontaneous hyaline cartilage regeneration can be induced in vivo in an osteochondral defect created in the femoral condyle by means of implanting the DN gel plug at the bottom of the defect so that an approximately 2-mm deep vacant space was intentionally left in the defect. This fact has prompted us to propose an innovative strategy without cell culture to repair osteochondral lesions in the femoral

  13. Fibrin glue fixation of a digital osteochondral fracture: case report and review of the literature.

    PubMed

    Shah, Munir A; Ebert, Andrew M; Sanders, William E

    2002-05-01

    Surgical treatment options for digital osteochondral fractures are limited by the small amount of bone available for fixation and the propensity for digital stiffness with the introduction of hardware. Fibrin sealant is used in a variety of clinical settings as a biologic bonding agent and may circumvent the drawbacks of traditional fixation or simple excision for certain digital osteochondral injuries. Successful use of fibrin sealant fixation for a patient with an osteochondral fracture involving the proximal interphalangeal joint is documented, and the literature on fibrin sealant for osseous fixation is reviewed.

  14. In vitro evaluation of alginate encapsulated adipose-tissue stromal cells for use as injectable bone graft substitute

    SciTech Connect

    Abbah, S.A.; Lu, W.W. . E-mail: wwlu@hkusua.hku.hk; Chan, D.; Cheung, K.M.C.; Liu, W.G.; Zhao, F.; Li, Z.Y.; Leong, J.C.Y.; Luk, K.D.K.

    2006-08-18

    This study aims to investigate the survival and osteogenic behavior of murine-derived adipose-tissue stromal cells (ATSCs) encapsulated in alginate microcapsules thereby instigating further studies in this cell delivery strategy for in vivo osteogenesis. Cell viability was quantified using a tetrazolium-based assay and osteogenic differentiation was evaluated by both alkaline-phosphatase (ALP) histochemistry and osteocalcin mRNA analysis. Following microencapsulation, cell numbers increased from 3.9 x 10{sup 3} on day 1 to 7.8 x 10{sup 3} on day 7 and maintained excellent viability in the course of 21-day culture. ALP was 6.9, 5.5, and 3.2 times higher than monolayer cultures on days 7, 14, and 21, respectively. In addition, osteocalcin mRNA was detectable in encapsulated cultures earlier (day 14) than monolayer cultures. We conclude that alginate microcapsules can act as three-dimensional matrix for ATSC proliferation and has potential for use as injectable, biodegradable scaffold in bone tissue engineering.

  15. Diagnosis of Knee Osteochondral Lesions With Ultrasound Imaging.

    PubMed

    Penttilä, Pekko; Liukkonen, Jukka; Joukainen, Antti; Virén, Tuomas; Jurvelin, Jukka S; Töyräs, Juha; Kröger, Heikki

    2015-10-01

    Evaluation of articular cartilage and subchondral bone is essential in the diagnosis of joint diseases and injuries. Interobserver and intraobserver reproducibilities of arthroscopic grading are only poor to moderate. Thus, for quantitative and objective evaluation of cartilage and subchondral bone, ultrasound arthroscopy (UA) has been introduced to clarify this dilemma. Assessment of the clinical feasibility of high-frequency ultrasonography (US) during 6 knee arthroscopies was conducted, and the surgical technique is presented. US imaging was conducted with a flexible 9-MHz US catheter inserted into the joint through conventional portals. US and arthroscopy videos were synchronously recorded, and US parameters for cartilage and subchondral bone characteristics were measured. Arthroscopy and US imaging were combined to perform cartilage grading. UA produced quantitative data on lesion size, as well as cartilage quality, and showed subchondral bone changes. Visualization of an osteochondritis dissecans lesion not detected by conventional arthroscopy and US-guided retrograde drilling were possible with UA. To conclude, UA proved to be clinically feasible and aided in the diagnosis when assessing knee osteochondral lesions. PMID:26697300

  16. OSTEOCHONDRAL AUTOLOGOUS TRANSPLANTATION FOR TREATING CHONDRAL LESIONS IN THE PATELLA

    PubMed Central

    Cohen, Moises; Amaro, Joicemar Tarouco; Fernandes, Ricardo de Souza Campos; Arliani, Gustavo Gonçalves; Astur, Diego da Costa; Kaleka, Camila Cohen; Skaf, Abdalla

    2015-01-01

    Objective: The primary aim of this study was to assess the clinical and functional evolution of patients with total-thickness symptomatic cartilaginous injury of the patellar joint surface, treated by means of osteochondral autologous transplantation. Methods: This prospective study was conducted from June 2008 to March 2011 and involved 17 patients. The specific questionnaires of Lysholm, Kujala and Fulkerson were completed preoperatively and one year postoperatively in order to assess the affected knee, and SF-36 was used to assess these patients’ general quality of life. The nonparametric paired Wilcoxon test was used for statistical analysis on the pre and postoperative questionnaires. The data were analyzed using the SPSS for Windows software, version 16.0, and a significance level of 5% was used. Results: The Lysholm preoperative and postoperative average scores were 54.59 and 75.76 points (p < 0.05). The Fulkerson pre and postoperative average scores were 52.53 and 78.41 points (p < 0.05). Conclusions: We believe that autologous osteochondral transplantation is a good treatment method for total-thickness symptomatic chondral lesions of the joint surface of the patella. PMID:27042645

  17. Diagnosis of Knee Osteochondral Lesions With Ultrasound Imaging

    PubMed Central

    Penttilä, Pekko; Liukkonen, Jukka; Joukainen, Antti; Virén, Tuomas; Jurvelin, Jukka S.; Töyräs, Juha; Kröger, Heikki

    2015-01-01

    Evaluation of articular cartilage and subchondral bone is essential in the diagnosis of joint diseases and injuries. Interobserver and intraobserver reproducibilities of arthroscopic grading are only poor to moderate. Thus, for quantitative and objective evaluation of cartilage and subchondral bone, ultrasound arthroscopy (UA) has been introduced to clarify this dilemma. Assessment of the clinical feasibility of high-frequency ultrasonography (US) during 6 knee arthroscopies was conducted, and the surgical technique is presented. US imaging was conducted with a flexible 9-MHz US catheter inserted into the joint through conventional portals. US and arthroscopy videos were synchronously recorded, and US parameters for cartilage and subchondral bone characteristics were measured. Arthroscopy and US imaging were combined to perform cartilage grading. UA produced quantitative data on lesion size, as well as cartilage quality, and showed subchondral bone changes. Visualization of an osteochondritis dissecans lesion not detected by conventional arthroscopy and US-guided retrograde drilling were possible with UA. To conclude, UA proved to be clinically feasible and aided in the diagnosis when assessing knee osteochondral lesions. PMID:26697300

  18. A 12 Months Clinical and Radiographic Study to Assess the Efficacy of Open Flap Debridement and Subepithelial Connective Tissue Graft in Management of Supracrestal Defects

    PubMed Central

    Chhina, Shivjot

    2015-01-01

    Background: An improvement in clinical parameters along with regeneration is the desired outcome of periodontal therapy. The aim of this study was to analyze and contrast the efficaciousness of combined open flap debridement (OFD) and subepithelial connective tissue graft (SECTG) to OFD in the management of periodontal supracrestal defects. Materials and Methods: Totally, 20 paired sites exhibiting supracrestal defects were subjected to surgical treatment adopting the split mouth design. The defects were divided randomly for treatment with OFD and SECTG (test) or OFD alone (control). The clinical effectiveness of the two arms of treatment was evaluated at 6 months and 12 months post-operatively by assessing clinical and radiographic parameters. The measurements carried out included probing pocket depth (PPD), relative attachment level (RAL), gingival marginal level, radiographic bone level (BL). Results: The mean reduction in PPD at 0-12 months was 3.20 ± 0.82 mm and RAL gain of 3.10 ± 1.51 mm was observed, the OFD and SECTG (test) group; corresponding observations for OFD (control) were 2.10 ± 0.63 mm and 1.90 ± 0.57 mm. However, BL changes did not follow the pattern of clinical improvement on the radiographic assessment of either treatment group. Post-operative evaluation was made. Improvement in different clinical parameters was statistically significant (P < 0.01). Conclusion: Treatment of supracrestal defects with a combination of OFD and SECTG led to significantly better clinical results compared to OFD alone. PMID:26464551

  19. Enamel matrix proteins (Emdogain) in combination with coronally advanced flap or subepithelial connective tissue graft in the treatment of shallow gingival recessions.

    PubMed

    Berlucchi, Ignazio; Francetti, Luca; Del Fabbro, Massimo; Testori, Tiziano; Weinstein, Roberto L

    2002-12-01

    This article describes two different surgical techniques of root coverage using Emdogain and shows preliminary results on 26 shallow recessions in 14 patients. For the treatment of 13 recessions, Emdogain was used in combination with a coronally advanced flap (CAF+EMD group). In the other 13 recessions, Emdogain and the flap were used in combination with a subepithelial connective tissue graft (CAF+CTG+EMD group). For the CAF+EMD group, the root coverage at 6 months was 93.97%, with an attachment gain of 3.2 mm; for the CAF+CTG+EMD group, the root coverage was 93.59%, with an attachment gain of 3.4 mm (no statistically significant difference between groups). When complete root coverage was not achieved, the residual recession was 1 mm in four cases and 2 mm in one case. Keratinized gingiva was increased for both groups, but more for the CAF+CTG+EMD group (1.38 mm versus 0.69 mm; statistically significant difference). Clinical attachment level decreased significantly in both groups, from 4.46 to 1.23 mm in the CAF+EMD group, and from 4.62 to 1.23 mm in the CAF+CTG+EMD group. Preliminary results show that Emdogain, in combination with CAF or CAF+CTG for the treatment of Miller Class I or II gingival recessions, displays good clinical results, with percentage of root coverage comparable or superior to other techniques. Further experimental studies on the dynamics of wound healing are needed to prove that EMD is really responsible for improving the percentage of regenerated versus repaired tissues with respect to other techniques. PMID:12516830

  20. The effect of polystyrene sodium sulfonate grafting on polyethylene terephthalate artificial ligaments on in vitro mineralisation and in vivo bone tissue integration

    PubMed Central

    Vaquette, Cédryck; Viateau, Véronique; Guérard, Sandra; Anagnostou, Fani; Manassero, Mathieu; Castner, David G.; Migonney, Véronique

    2013-01-01

    This study investigates the impact of polystyrene sodium sulfonate (PolyNaSS) grafting onto the osseointegration of a polyethylene terephthalate artificial ligament (Ligament Advanced Reinforcement System, LARS™) used for Anterior Cruciate Ligament (ACL). The performance of grafted and non-grafted ligaments was assessed in vitro by culturing human osteoblasts under osteogenic induction and this demonstrated that the surface modification was capable of up-regulating the secretion of ALP and induced higher level of mineralisation as measured 6 weeks post-seeding by Micro-Computed Tomography. Grafted and non-grafted LARS™ were subsequently implanted in an ovine model for ACL reconstruction and the ligament-to-bone interface was evaluated by histology and biomechanical testing 3 and 12 months post-implantation. The grafted ligaments exhibited more frequent direct ligament-to-bone contact and bone formation in the core of the ligament at the later time point than the nongrafted specimens, the grafting also significantly reduced the fibrous encapsulation of the ligament 12 months post-implantation. However, this improved osseo-integration was not translated into a significant increase in the biomechanical pull-out loads. These results provide evidences that PolyNaSS grafting improved the osseo-integration of the artificial ligament within the bone tunnels. This might positively influence the outcome of the surgical reconstructions, as higher ligament stability is believed to limit micro-movement and therefore permits earlier and enhanced healing. PMID:23790438

  1. Treatment of a traumatic osteochondral defect in the thumb carpometacarpal joint with a periosteal autograft.

    PubMed

    Stein, B E; Rosenwasser, M P

    1999-11-01

    We report a case in which an autogenous periosteal autograft was used to resurface a large osteochondral defect in the thumb carpometacarpal joint of a young woman. Good results were found at 4-year follow-up examination.

  2. Arthroscopic Autologous Chondrocyte Transplantation for Osteochondritis Dissecans of the Elbow.

    PubMed

    Patzer, Thilo; Krauspe, Ruediger; Hufeland, Martin

    2016-06-01

    Osteochondritis dissecans of the humeral capitellum is characterized by separation of a circumscript area of the articular surface and the subchondral bone in juvenile patients. In advanced lesions, arthroscopic fragment refixation or fragment removal with microfracturing or drilling can be successful. The purpose of this technical note is to describe an all-arthroscopic surgical technique for 3-dimensional purely autologous chondrocyte transplantation for osteochondral lesions of the humeral capitellum. PMID:27656389

  3. Biomarkers Affected by Impact Severity during Osteochondral Injury.

    PubMed

    Waters, Nicole Poythress; Stoker, Aaron M; Pfeiffer, Ferris M; Cook, James L

    2015-06-01

    Osteochondral injury elevates the risk for developing posttraumatic osteoarthritis (PTOA). Therefore, our objective was to evaluate the relationship between impact severity during injury to cell viability and biomarkers possibly involved in PTOA. Osteochondral explants (6 mm, n = 72) were harvested from cadaveric femoral condyles (N = 6). Using a test machine, each explant (except for No Impact) was subjected to mechanical impact at a velocity of 100 mm/s to 0.25, 0.5, 0.75, 1.0, or 1.25 mm maximum compression corresponding to Low, Low-Moderate, Moderate, Moderate-High, or High impact groups. Cartilage cell viability, collagen content, and proteoglycan content were assessed at either day 0 or after 12 days of culture. Culture media were assessed for prostaglandin E2 (PGE2); nitric oxide; granulocyte macrophage colony-stimulating factor (GM-CSF); interferon gamma (IFNγ); interleukin (IL)-2, -4, -6, -7, -8, -10, -15, -18; interferon gamma-induced protein 10 (IP-10); keratinocyte-derived chemoattractant (KC); monocyte chemoattractant protein-1 (MCP-1); tumor necrosis factor alpha (TNFα); and matrix metalloproteinase-2, -3, -8, -9, -13. There was increased impact energy absorbed for the High group compared with the Moderate-High group, Moderate group, and Low-Moderate group (p = 0.011, 0.048, 0.008, respectively). At day 0, there was decreased area cell viability for the High group compared with the Low-Moderate group (p = 0.035). At day 1, PGE2 was increased for the High group compared with the Moderate, Low-Moderate, Low, and No Impact groups (p ≤ 0.01). Cumulative PGE2 was increased for the Moderate-High and High groups compared with the Moderate, Low-Moderate, Low, and No Impact groups (p ≤ 0.036). At day 1, MCP-1 was increased for the Moderate-High and High groups compared with the Low and No Impact groups (p ≤ 0.032). Impact to osteochondral explants resulted in multiple levels of severity. PGE2 was sensitive to impact

  4. Normal reproductive development of pigs produced using sperm retrieved from immature testicular tissue cryopreserved and grafted into nude mice.

    PubMed

    Kaneko, Hiroyuki; Kikuchi, Kazuhiro; Tanihara, Fuminori; Noguchi, Junko; Nakai, Michiko; Ito, Junya; Kashiwazaki, Naomi

    2014-07-15

    Xenografting of immature testicular tissue combined with cryopreservation can preserve and use genetic information of prepubertal animals. For establishment of this new approach, it is essential to clarify whether offspring derived from sperm grown in host mice harboring cryopreserved xenografts show normal reproductive development. This study examined serum profiles of gonadal hormones during sexual maturation in pigs generated by intracytoplasmic sperm injection using sperm derived from cryopreserved xenografts (CryoXeno pigs; three males and three females). We also assessed the reproductive abilities of the male CryoXeno pigs by mating them with conventionally produced (conventional) pigs, and by examining the in vitro fertilizing ability of their sperm. For female CryoXeno pigs, reproductive ability was evaluated by artificial insemination with semen from a conventional boar. During the growth of male CryoXeno pigs, the serum concentrations of inhibin and testosterone showed similar changes (P > 0.17) to those in conventional pigs (n = 4). Histologic analyses of the testes revealed no differences (P > 0.2) in the growth and differentiation of seminiferous tubules between CryoXeno and conventional pigs. Three conventional sows delivered 13.0 ± 1.0 (mean ± standard error of the mean) live piglets after being mated with the three CryoXeno males. Sperm obtained from all CryoXeno pigs had the ability to penetrate oocytes, and these fertilized oocytes reached the blastocyst stage in vitro. During the growth of female CryoXeno pigs, the serum inhibin profile was similar (P > 0.17) to that observed in conventional pigs (n = 5). The first rise in serum progesterone concentration to more than 2 ng/mL was noted at 32.0 ± 2.3 weeks of age in the CryoXeno pigs and at 32.0 ± 3.3 weeks in the conventional pigs, suggesting that both pigs reached puberty at a similar age. After puberty, female CryoXeno pigs farrowed 8.3 ± 1.7 (mean ± standard error of the mean; n = 3

  5. Photocrosslinked layered gelatin-chitosan hydrogel with graded compositions for osteochondral defect repair.

    PubMed

    Han, Fengxuan; Yang, Xiaoling; Zhao, Jin; Zhao, Yunhui; Yuan, Xiaoyan

    2015-04-01

    A layered gelatin-chitosan hydrogel with graded composition was prepared via photocrosslinking to simulate the polysaccharide/collagen composition of the natural tissue and mimic the multi-layered gradient structure of the cartilage-bone interface tissue. Firstly, gelatin and carboxymethyl chitosan were reacted with glycidyl methacrylate (GMA) to obtain methacrylated gelatin (Gtn-GMA) and carboxymethyl chitosan (CS-GMA). Then, the mixed solutions of Gtn-GMA in different methacrylation degrees with CS-GMA were prepared to form the superficial, transitional and deep layers of the hydrogel, respectively under the irradiation of ultraviolet light, while polyhedral oligomeric silsesquioxane was introduced in the deep layer to improve the mechanical properties. Results suggested that the pore sizes of the superficial, transitional and deep layers of the layered hydrogel were 115 ± 30, 94 ± 34, 51 ± 12 μm, respectively and their porosities were all higher than 80 %. The compressive strengths of them were 165 ± 54, 565 ± 50 and 993 ± 108 kPa, respectively and the strain of the gradient hydrogel decreased along the thickness direction, similar to the natural tissue. The in vitro cytotoxicity results showed that the hydrogel had good cytocompatibility and the in vivo repair results of osteochondral defect demonstrated remarkable recovery by using the gradient gelatin-chitosan hydrogel, especially when the hydrogel loading transforming growth factor-β1. Therefore, it was suggested that the prepared layered gelatin-chitosan hydrogel in this study could be potentially used to promote cartilage-bone interface tissue repair.

  6. Adult osteochondritis dissecans and focussed ESWT: A successful treatment option.

    PubMed

    Thiele, S; Thiele, R; Gerdesmeyer, L

    2015-12-01

    Extracorporeal shockwave therapy (ESWT) has gained acceptance in the medical field and in the treatment of non-unions and delayed bone healing. ESWT has been used effectively for many years as a noninvasive surgical procedure. The idea of treating Osteochondritis dissecans of knee and talus arose in the middle of the 1990's. OCD is known as a pre-arthritic factor in the long-term and still there is no consistent treatment. In the literature there is still only a small number of publications but international societies for shockwave treatment are convinced that ESWT on OCD shows to be an effective and safe method in the treatment of OCD in the early stages. We want to summarize the actual data on the treatment of OCD by ESWT.

  7. Arthroscopic Microfracture for Osteochondritis Dissecans Lesions of the Capitellum.

    PubMed

    Camp, Christopher L; Dines, Joshua S; Degen, Ryan M; Sinatro, Alec L; Altchek, David W

    2016-06-01

    Capitellar osteochondritis dissecans (OCD) is one of the most common causes of elbow pain and dysfunction in adolescent athletes. It typically occurs in gymnasts and overhead throwers and presents along a wide spectrum of severity. Stable lesions can typically be treated with conservative therapy; however, those presenting with instability, fragmentation, or loose bodies generally require surgical intervention. Although there are a number of described surgical options used to treat capitellar OCD lesions, microfracture is one of the most commonly performed and well studied. Patients who are candidates for microfracture generally have favorable outcomes with high rates of return to athletic activity after postoperative rehabilitation. In this work, we present our preferred arthroscopic technique for microfracture of OCD lesions of the capitellum. This technique is most suitable for patients with unstable or fragmented OCD lesions that are less than 1 cm in diameter and do not violate the lateral-most articular margin of the capitellum. PMID:27656365

  8. Stifle osteochondritis dissecans in snow leopards (Uncia uncia).

    PubMed

    Herrin, Kimberly Vinette; Allan, Graeme; Black, Anthony; Aliah, Rhonda; Howlett, Cameron Rolfe

    2012-06-01

    Three snow leopard (Uncia uncia) cubs, female and male siblings and an unrelated female, had lameness attributed to osteochondritis dissecans (OCD) lesions noted at 6, 8, and 10 mo of age, respectively. All cubs were diagnosed with OCD via radiographs. The sibling cubs both had lesions of the right lateral femoral condyles, while the unrelated cub had bilateral lesions of the lateral femoral condyles. Subsequently, OCD was confirmed in all three cases during surgical correction of the lateral femoral condyle lesions via lateral stifle arthrotomies, flap removal, and debridement of the defect sites. Histopathology also supported the diagnosis of OCD. Postoperatively, the sibling cubs developed seromas at the incision sites and mild lameness, which resolved within a month. To date, two cubs have been orthopedically sound, while one of the sibling cubs has developed mild osteoarthritis. OCD has rarely been reported in domestic felids, and to the authors' knowledge these are the first reported cases of OCD in nondomestic felids.

  9. Stifle osteochondritis dissecans in snow leopards (Uncia uncia).

    PubMed

    Herrin, Kimberly Vinette; Allan, Graeme; Black, Anthony; Aliah, Rhonda; Howlett, Cameron Rolfe

    2012-06-01

    Three snow leopard (Uncia uncia) cubs, female and male siblings and an unrelated female, had lameness attributed to osteochondritis dissecans (OCD) lesions noted at 6, 8, and 10 mo of age, respectively. All cubs were diagnosed with OCD via radiographs. The sibling cubs both had lesions of the right lateral femoral condyles, while the unrelated cub had bilateral lesions of the lateral femoral condyles. Subsequently, OCD was confirmed in all three cases during surgical correction of the lateral femoral condyle lesions via lateral stifle arthrotomies, flap removal, and debridement of the defect sites. Histopathology also supported the diagnosis of OCD. Postoperatively, the sibling cubs developed seromas at the incision sites and mild lameness, which resolved within a month. To date, two cubs have been orthopedically sound, while one of the sibling cubs has developed mild osteoarthritis. OCD has rarely been reported in domestic felids, and to the authors' knowledge these are the first reported cases of OCD in nondomestic felids. PMID:22779240

  10. Osteochondral Fractures of the Lateral Femoral Trochlea in Young Athletes

    PubMed Central

    Walsh, Stewart

    2016-01-01

    Method: Between May 2012 and September 2014 cluster of five patients with large osteochondral fractures of the lateral femoral trochlea were treated at our institution. These all occurred in high level male athletes, one at a decathlete and the other four soccer players. The MRI scan showed a characteristic appearance of a large subchondral fracture involving most of the lateral femoral trochlea. All patients were symptomatic. The patients were treated with open reduction and internal fixation using headless compression screws. The operative technique and short term results will be outlined. Results: Fixation appears successful in most cases. Conclusion: This appears to be a repetitive trauma related injury that occurs in young high-level athletes.

  11. Polyvinyl Alcohol Hydrogel Irradiated and Acetalized for Osteochondral Defect Repair: Mechanical, Chemical, and Histological Evaluation after Implantation in Rat Knees

    PubMed Central

    Batista, N. A.; Rodrigues, A. A.; Bavaresco, V. P.; Mariolani, J. R. L.; Belangero, W. D.

    2012-01-01

    Polyvinyl Alcohol (PVA) hydrogel plugs were implanted in artificial osteochondral defects on the trochlear groove of rat knees. After 0, 3, 6, 12, and 24 weeks of followup, samples containing the implants were mechanically evaluated by creep indentation test, chemically, and histologically by optical microscopy. The mechanical test pointed towards an increase of the implant creep modulus and the chemical analysis exhibited an increasing concentration of calcium and phosphorus within the implants over time. Optical microscopy showed no foreign body reaction and revealed formation, differentiation, and maintenance of new tissue at the defect/implant interface. The absence of implant wear indicated that the natural articular lubrication process was not disturbed by the implant. The performance of the irradiated and acetalized PVA was considered satisfactory for the proposed application. PMID:23197982

  12. Approach alternatives for treatment of osteochondral lesions of the talus.

    PubMed

    Navid, David O; Myerson, Mark S

    2002-09-01

    Osteochondral lesions of the talus are common injuries, especially in the athletic population. Although multiple etiologies exist, lateral lesions have a higher incidence of association with a specific traumatic event. It has been postulated that lateral lesions are produced when the anterolateral aspect of the talar dome impacts the fibula on application of an inversion or dorsiflexion stress to the ankle [2]. There is general agreement that surgery should be performed only in symptomatic cases, as osteochondral lesions of the talar dome show little tendency to progression and do not seem to lead to osteoarthritis [10,42]. Appropriate preoperative imaging is extremely important. Standard radiographs of the ankle supplemented with lateral plantar flexion and dorsiflexion views and CT or Mr imaging can be helpful in evaluating the size, depth, and exact location of the lesion. This information is essential in planning the appropriate surgical procedure. Although many stage I and II lesions respond well to conservative therapy and a period of immobilization, some higher-grade lesions (stage III and IV) eventually require surgical intervention. Most lesions can be approached arthroscopically. Many arthroscopic procedures have been shown to be successful, including debridement with abrasion chondroplasty, subchondral drilling, and microfracture [18-20]. But certain larger or refractory lesions may require an open approach to the ankle joint to restore the articular cartilage. Most lateral lesions have an anterior location and are easily accessible through a standard anterolateral approach. Most medial lesions are located on the posterior talar dome, and a medial malleolar osteotomy is usually required. Osteotomies, in particular of the medial malleolus, should be approached carefully. The possible complications of nonunion and malunion can lead to progressive arthritis of the ankle joint.

  13. Plant grafting: new mechanisms, evolutionary implications

    PubMed Central

    Goldschmidt, Eliezer E.

    2014-01-01

    Grafting, an old plant propagation practice, is still widely used with fruit trees and in recent decades also with vegetables. Taxonomic proximity is a general prerequisite for successful graft-take and long-term survival of the grafted, composite plant. However, the mechanisms underlying interspecific graft incompatibility are as yet insufficiently understood. Hormonal signals, auxin in particular, are believed to play an important role in the wound healing and vascular regeneration within the graft union zone. Incomplete and convoluted vascular connections impede the vital upward and downward whole plant transfer routes. Long-distance protein, mRNA and small RNA graft-transmissible signals currently emerge as novel mechanisms which regulate nutritional and developmental root/top relations and may play a pivotal role in grafting physiology. Grafting also has significant pathogenic projections. On one hand, stock to scion mechanical contact enables the spread of diseases, even without a complete graft union. But, on the other hand, grafting onto resistant rootstocks serves as a principal tool in the management of fruit tree plagues and vegetable soil-borne diseases. The ‘graft hybrid’ historic controversy has not yet been resolved. Recent evidence suggests that epigenetic modification of DNA-methylation patterns may account for certain graft-transformation phenomena. Root grafting is a wide spread natural phenomenon; both intraspecific and interspecific root grafts have been recorded. Root grafts have an evolutionary role in the survival of storm-hit forest stands as well as in the spread of devastating diseases. A more fundamental evolutionary role is hinted by recent findings that demonstrate plastid and nuclear genome transfer between distinct Nicotiana species in the graft union zone, within a tissue culture system. This has led to the formation of alloploid cells that, under laboratory conditions, gave rise to a novel, alloploid Nicotiana species

  14. Controlled Release Strategies for Bone, Cartilage, and Osteochondral Engineering—Part II: Challenges on the Evolution from Single to Multiple Bioactive Factor Delivery

    PubMed Central

    Santo, Vítor E.; Mano, João F.; Reis, Rui L.

    2013-01-01

    The development of controlled release systems for the regeneration of bone, cartilage, and osteochondral interface is one of the hot topics in the field of tissue engineering and regenerative medicine. However, the majority of the developed systems consider only the release of a single growth factor, which is a limiting step for the success of the therapy. More recent studies have been focused on the design and tailoring of appropriate combinations of bioactive factors to match the desired goals regarding tissue regeneration. In fact, considering the complexity of extracellular matrix and the diversity of growth factors and cytokines involved in each biological response, it is expected that an appropriate combination of bioactive factors could lead to more successful outcomes in tissue regeneration. In this review, the evolution on the development of dual and multiple bioactive factor release systems for bone, cartilage, and osteochondral interface is overviewed, specifically the relevance of parameters such as dosage and spatiotemporal distribution of bioactive factors. A comprehensive collection of studies focused on the delivery of bioactive factors is also presented while highlighting the increasing impact of platelet-rich plasma as an autologous source of multiple growth factors. PMID:23249320

  15. Cartilage resurfacing potential of PLGA scaffolds loaded with autologous cells from cartilage, fat, and bone marrow in an ovine model of osteochondral focal defect.

    PubMed

    Caminal, M; Peris, D; Fonseca, C; Barrachina, J; Codina, D; Rabanal, R M; Moll, X; Morist, A; García, F; Cairó, J J; Gòdia, F; Pla, A; Vives, J

    2016-08-01

    Current developments in tissue engineering strategies for articular cartilage regeneration focus on the design of supportive three-dimensional scaffolds and their use in combination with cells from different sources. The challenge of translating initial successes in small laboratory animals into the clinics involves pilot studies in large animal models, where safety and efficacy should be investigated during prolonged follow-up periods. Here we present, in a single study, the long-term (up to 1 year) effect of biocompatible porous scaffolds non-seeded and seeded with fresh ex vivo expanded autologous progenitor cells that were derived from three different cell sources [cartilage, fat and bone marrow (BM)] in order to evaluate their advantages as cartilage resurfacing agents. An ovine model of critical size osteochondral focal defect was used and the test items were implanted arthroscopically into the knees. Evidence of regeneration of hyaline quality tissue was observed at 6 and 12 months post-treatment with variable success depending on the cell source. Cartilage and BM-derived mesenchymal stromal cells (MSC), but not those derived from fat, resulted in the best quality of new cartilage, as judged qualitatively by magnetic resonance imaging and macroscopic assessment, and by histological quantitative scores. Given the limitations in sourcing cartilage tissue and the risk of donor site morbidity, BM emerges as a preferential source of MSC for novel cartilage resurfacing therapies of osteochondral defects using copolymeric poly-D,L-lactide-co-glycolide scaffolds.

  16. Osteochondral defect repair using a polyvinyl alcohol-polyacrylic acid (PVA-PAAc) hydrogel.

    PubMed

    Bichara, David A; Bodugoz-Sentruk, Hatice; Ling, Doris; Malchau, Erik; Bragdon, Charles R; Muratoglu, Orhun K

    2014-08-01

    Poly(vinyl alcohol) (PVA) hydrogels can be candidates for articular cartilage repair due to their high water content. We synthesized a PVA-poly(acrylic acid) (PAAc) hydrogel formulation and determined its ability to function as a treatment option for condylar osteochondral (OC) defects in a New Zealand white rabbit (NZWR) model for 12 weeks and 24 weeks. In addition to hydrogel OC implants, tensile bar-shaped hydrogels were also implanted subcutaneously to evaluate changes in mechanical properties as a function of in vivo duration. There were no statistically significant differences (p > 0.05) in the water content measured in the OC hydrogel implant that was harvested after 12 weeks and 24 weeks, and non-implanted controls. There were no statistically significant differences (p > 0.05) in the break stress, strain at break or modulus of the tensile bars either between groups. Histological analysis of the OC defect, synovial capsule and fibrous tissue around the tensile bars determined hydrogel biocompatibility. Twelve-week hydrogels were found to be in situ flush with the articular cartilage; meniscal tissue demonstrated an intact surface. Twenty-four week hydrogels protruded from the defect site due to lack of integration with subchondral tissue, causing fibrillation to the meniscal surface. Condylar micro-CT scans ruled out osteolysis and bone cysts of the subchondral bone, and no PVA-PAAc hydrogel contents were found in the synovial fluid. The PVA-PAAc hydrogel was determined to be fully biocompatible, maintained its properties over time, and performed well at the 12 week time point. Physical fixation of the PVA-PAAc hydrogel to the subchondral bone is required to ensure long-term performance of hydrogel plugs for OC defect repair.

  17. Early secondary bone grafting of alveolar cleft defects. A comparison between chin and rib grafts.

    PubMed

    Borstlap, W A; Heidbuchel, K L; Freihofer, H P; Kuijpers-Jagtman, A M

    1990-07-01

    Since 1981 in cleft lip and palate patients a combined surgical-orthodontic procedure has been performed to eliminate the residual alveolar cleft. For early secondary bone grafting (before the eruption of the canine tooth) initially the graft tissue of choice was rib. Since 1984 chin bone has also been used. Sixty one patients with complete unilateral clefts were reviewed (mean age 9.5 years). 15.7% of the rib graft cases showed resorption of the graft of 50% and more. Such resorption was not found in any of the chin graft cases. No complications such as wound dehiscence, sequestration, excessive resorption of bone or recurrence of an oro-nasal fistula were found in the chin graft group. This leads to the conclusion that if enough bone is available in the chin region to bridge the defect, this graft is preferable to a rib graft.

  18. Gene signatures of postoperative atrial fibrillation in atrial tissue after coronary artery bypass grafting surgery in patients receiving β-blockers

    PubMed Central

    Kertai, Miklos D.; Qi, Wenjing; Li, Yi-Ju; Lombard, Frederick W.; Liu, Yutao; Smith, Michael. P.; Stafford-Smith, Mark; Newman, Mark F.; Milano, Carmelo A.; Mathew, Joseph P.; Podgoreanu, Mihai V.

    2016-01-01

    Atrial tissue gene expression profiling may help to determine how differentially expressed genes in the human atrium before cardiopulmonary bypass (CPB) are related to subsequent biologic pathway activation patterns, and whether specific expression profiles are associated with an increased risk for postoperative atrial fibrillation (AF) or altered response to β-blocker (BB) therapy after coronary artery bypass grafting (CABG) surgery. Right atrial appendage (RAA) samples were collected from 45 patients who were receiving perioperative BB treatment, and underwent CABG surgery. The isolated RNA samples were used for microarray gene expression analysis, to identify probes that were expressed differently in patients with and without postoperative AF. Gene expression analysis was performed to identify probes that were expressed differently in patients with and without postoperative AF. Gene set enrichment analysis (GSEA) was performed to determine how sets of genes might be systematically altered in patients with postoperative AF. Of the 45 patients studied, genomic DNA from 42 patients was used for target sequencing of 66 candidate genes potentially associated with AF, and 2,144 single-nucleotide polymorphisms (SNPs) were identified. We then performed expression quantitative trait loci (eQTL) analysis to determine the correlation between SNPs identified in the genotyped patients, and RAA expression. Probes that met a false discovery rate < 0.25 were selected for eQTL analysis. Of the 17,678 gene expression probes analyzed, 2 probes met our prespecified significance threshold of false discovery rate < 0.25. The most significant probe corresponded to vesicular overexpressed in cancer – prosurvival protein 1 gene (VOPP1; 1.83 fold change; P = 3.47 × 10−7), and was up-regulated in patients with postoperative AF, whereas the second most significant probe, which corresponded to the LOC389286 gene (0.49 fold change; P = 1.54 × 10−5), was down-regulated in patients

  19. Selection of the most compatible graft recipient by computer program, used in regional tissue typing laboratory of Hellas (R.T.T.L.).

    PubMed

    Kakas, P K; Adam, K; Lazidou, P; Papakyriazi, H; Parapanisiou, E; Polymenides, Z

    1994-01-01

    The purpose of this study was to present the new computer program that we developed in the regional tissue typing laboratory (R.T.T.L.) and use for the selection of the most suitable recipient for cadaveric allografts in a more efficient way. This new program was written and compiled in TURBO PASCAL 6.0, sorts all possible recipients to the HLA type of a donor, checks for the existence of splits and utilises them, and when requested, gives out results to more specific inquiries, i.e. all compatible recipients from 2DR2B2A to 1DR0B0A matching. It can also forecast success percentages according to different factors, i.e. combination of donor's and recipient's ages, HLA matching etc. The material used for this study were the patients who are registered in the formal cadaveric transplantation list of R.T.T.L. We have used this program since 2 January 1992 together with the old one. Since then we found that the new program is faster in sorting all the possible recipients of cadaveric renal allografts according to the criteria already mentioned. The total selection time, with all the criteria activated, averages a few seconds, whereas with the old program it took approximately 2 min just for the sorting of HLA matching, without any other criteria activated. In the printout of the final result of each inquiry are all the possible recipients in the sorted order together with relevant data (telephone number, address etc.). As a result, the laboratory personnel has been free from the tedious task of this sorting which was initially done by hand and the possibility of error has been eliminated. The program was developed exclusively by doctors and all the updates needed are done by the users. More important, however, is the fact that in many cases the time of cold ischaemia was reduced by more than 30 min with all the obvious advantages for the longevity of the graft's life. PMID:11271300

  20. Pulsed electromagnetic fields after arthroscopic treatment for osteochondral defects of the talus: double-blind randomized controlled multicenter trial

    PubMed Central

    van Bergen, Christiaan JA; Blankevoort, Leendert; de Haan, Rob J; Sierevelt, Inger N; Meuffels, Duncan E; d'Hooghe, Pieter RN; Krips, Rover; van Damme, Geert; van Dijk, C Niek

    2009-01-01

    Background Osteochondral talar defects usually affect athletic patients. The primary surgical treatment consists of arthroscopic debridement and microfracturing. Although this is mostly successful, early sport resumption is difficult to achieve, and it can take up to one year to obtain clinical improvement. Pulsed electromagnetic fields (PEMFs) may be effective for talar defects after arthroscopic treatment by promoting tissue healing, suppressing inflammation, and relieving pain. We hypothesize that PEMF-treatment compared to sham-treatment after arthroscopy will lead to earlier resumption of sports, and aim at 25% increase in patients that resume sports. Methods/Design A prospective, double-blind, randomized, placebo-controlled trial (RCT) will be conducted in five centers throughout the Netherlands and Belgium. 68 patients will be randomized to either active PEMF-treatment or sham-treatment for 60 days, four hours daily. They will be followed-up for one year. The combined primary outcome measures are (a) the percentage of patients that resume and maintain sports, and (b) the time to resumption of sports, defined by the Ankle Activity Score. Secondary outcome measures include resumption of work, subjective and objective scoring systems (American Orthopaedic Foot and Ankle Society – Ankle-Hindfoot Scale, Foot Ankle Outcome Score, Numeric Rating Scales of pain and satisfaction, EuroQol-5D), and computed tomography. Time to resumption of sports will be analyzed using Kaplan-Meier curves and log-rank tests. Discussion This trial will provide level-1 evidence on the effectiveness of PEMFs in the management of osteochondral ankle lesions after arthroscopy. Trial registration Netherlands Trial Register (NTR1636) PMID:19591674

  1. Osteochondral lesions in distal tarsal joints of Icelandic horses reveal strong associations between hyaline and calcified cartilage abnormalities.

    PubMed

    Ley, C J; Ekman, S; Hansson, K; Björnsdóttir, S; Boyde, A

    2014-03-25

    Osteochondral lesions in the joints of the distal tarsal region of young Icelandic horses provide a natural model for the early stages of osteoarthritis (OA) in low-motion joints. We describe and characterise mineralised and non-mineralised osteochondral lesions in left distal tarsal region joint specimens from twenty-two 30 ±1 month-old Icelandic horses. Combinations of confocal scanning light microscopy, backscattered electron scanning electron microscopy (including, importantly, iodine staining) and three-dimensional microcomputed tomography were used on specimens obtained with guidance from clinical imaging. Lesion-types were described and classified into groups according to morphological features. Their locations in the hyaline articular cartilage (HAC), articular calcified cartilage (ACC), subchondral bone (SCB) and the joint margin tissues were identified and their frequency in the joints recorded. Associations and correlations between lesion-types were investigated for centrodistal joints only. In centrodistal joints the lesion-types HAC chondrocyte loss, HAC fibrillation, HAC central chondrocyte clusters, ACC arrest and ACC advance had significant associations and strong correlations. These lesion-types had moderate to high frequency in centrodistal joints but low frequencies in tarsometatarsal and talocalcaneal-centroquartal joints. Joint margin lesion-types had no significant associations with other lesion-types in the centrodistal joints but high frequency in both the centrodistal and tarsometatarsal joints. The frequency of SCB lesion-types in all joints was low. Hypermineralised infill phase lesion-types were detected. Our results emphasise close associations between HAC and ACC lesions in equine centrodistal joints and the importance of ACC lesions in the development of OA in low-motion compression-loaded equine joints.

  2. Evaluation of Cartilage Repair by Mesenchymal Stem Cells Seeded on a PEOT/PBT Scaffold in an Osteochondral Defect.

    PubMed

    Barron, V; Merghani, K; Shaw, G; Coleman, C M; Hayes, J S; Ansboro, S; Manian, A; O'Malley, G; Connolly, E; Nandakumar, A; van Blitterswijk, C A; Habibovic, P; Moroni, L; Shannon, F; Murphy, J M; Barry, F

    2015-09-01

    The main objective of this study was to evaluate the effectiveness of a mesenchymal stem cell (MSC)-seeded polyethylene-oxide-terephthalate/polybutylene-terephthalate (PEOT/PBT) scaffold for cartilage tissue repair in an osteochondral defect using a rabbit model. Material characterisation using scanning electron microscopy indicated that the scaffold had a 3D architecture characteristic of the additive manufacturing fabrication method, with a strut diameter of 296 ± 52 μm and a pore size of 512 ± 22 μm × 476 ± 25 μm × 180 ± 30 μm. In vitro optimisation revealed that the scaffold did not generate an adverse cell response, optimal cell loading conditions were achieved using 50 μg/ml fibronectin and a cell seeding density of 25 × 10(6) cells/ml and glycosaminoglycan (GAG) accumulation after 28 days culture in the presence of TGFβ3 indicated positive chondrogenesis. Cell-seeded scaffolds were implanted in osteochondral defects for 12 weeks, with cell-free scaffolds and empty defects employed as controls. On examination of toluidine blue staining for chondrogenesis and GAG accumulation, both the empty defect and the cell-seeded scaffold appeared to promote repair. However, the empty defect and the cell-free scaffold stained positive for collagen type I or fibrocartilage, while the cell-seeded scaffold stained positive for collagen type II indicative of hyaline cartilage and was statistically better than the cell-free scaffold in the blinded histological evaluation. In summary, MSCs in combination with a 3D PEOT/PBT scaffold created a reparative environment for cartilage repair.

  3. New perspectives for articular cartilage repair treatment through tissue engineering: A contemporary review

    PubMed Central

    Musumeci, Giuseppe; Castrogiovanni, Paola; Leonardi, Rosalia; Trovato, Francesca Maria; Szychlinska, Marta Anna; Di Giunta, Angelo; Loreto, Carla; Castorina, Sergio

    2014-01-01

    In this paper review we describe benefits and disadvantages of the established methods of cartilage regeneration that seem to have a better long-term effectiveness. We illustrated the anatomical aspect of the knee joint cartilage, the current state of cartilage tissue engineering, through mesenchymal stem cells and biomaterials, and in conclusion we provide a short overview on the rehabilitation after articular cartilage repair procedures. Adult articular cartilage has low capacity to repair itself, and thus even minor injuries may lead to progressive damage and osteoarthritic joint degeneration, resulting in significant pain and disability. Numerous efforts have been made to develop tissue-engineered grafts or patches to repair focal chondral and osteochondral defects, and to date several researchers aim to implement clinical application of cell-based therapies for cartilage repair. A literature review was conducted on PubMed, Scopus and Google Scholar using appropriate keywords, examining the current literature on the well-known tissue engineering methods for the treatment of knee osteoarthritis. PMID:24829869

  4. Citrate cross-linked gels with strain reversibility and viscoelastic behavior accelerate healing of osteochondral defects in a rabbit model.

    PubMed

    Ghosh, Paulomi; Rameshbabu, Arun Prabhu; Dhara, Santanu

    2014-07-22

    Most living tissues are viscoelastic in nature. Self-repair due to the dissipation of energy by reversible bonds prevents the rupture of the molecular backbone in these tissues. Recent studies, therefore, have aimed to synthesize biomaterials that approximate the mechanical performance of biological materials with self-recovery properties. We report an environmentally friendly method for the development of ionotropically cross-linked viscoelastic chitosan gels with a modulus comparable to that of living tissues. The strain recovery property was found to be highest for the gels with the lowest cross-linking density. The force-displacement curve showed significant hysteresis due to the presence of reversible bonds in the cross-linked gels. Nanoindentation studies demonstrated the creep phenomenon for the cross-linked chitosan gels. Creep, hysteresis, and plasticity index confirmed the viscoelastic behavior of the cross-linked gels. The viscoelastic gels were implanted at osteochondral defect sites to assess the tissue regeneration ability. In vivo results demonstrated early cartilage formation and woven bone deposition for defects filled with the gels compared to nontreated defects. PMID:24971647

  5. Single-layer MoS2 nanosheet grafted upconversion nanoparticles for near-infrared fluorescence imaging-guided deep tissue cancer phototherapy.

    PubMed

    Han, Jianyu; Xia, Hongping; Wu, Yafeng; Kong, Shik Nie; Deivasigamani, Amudha; Xu, Rong; Hui, Kam M; Kang, Yuejun

    2016-04-21

    A multifunctional nanostructure is prepared by covalently grafting upconversion nanoparticles (UCNPs) with chitosan functionalized MoS2 (MoS2-CS) and folic acid (FA) and then loading phthalocyanine (ZnPc) on the surface of MoS2, which integrates photodynamic therapy (PDT) with photothermal therapy (PTT) and upconversion luminescence imaging into one system for enhanced antitumor efficiency. PMID:27035265

  6. Acute Osteochondral Fractures in the Lower Extremities - Approach to Identification and Treatment

    PubMed Central

    Pedersen, M.E; DaCambra, M.P; Jibri, Z; Dhillon, S; Jen, H; Jomha, N.M

    2015-01-01

    Chondral and osteochondral fractures of the lower extremities are important injuries because they can cause pain and dysfunction and often lead to osteoarthritis. These injuries can be misdiagnosed initially which may impact on the healing potential and result in poor long-term outcome. This comprehensive review focuses on current pitfalls in diagnosing acute osteochondral lesions, potential investigative techniques to minimize diagnostic errors as well as surgical treatment options. Acute osteochondral fractures are frequently missed and can be identified more accurately with specific imaging techniques. A number of different methods can be used to fix these fractures but attention to early diagnosis is required to limit progression to osteoarthritis. These fractures are common with joint injuries and early diagnosis and treatment should lead to improved long term outcomes. PMID:26587063

  7. Acute Delamination of Commercially Available Decellularized Osteochondral Allograft Plugs: A Report of Two Cases.

    PubMed

    Degen, Ryan M; Tetreault, Danielle; Mahony, Greg T; Williams, Riley J

    2016-10-01

    Articular cartilage injuries, and corresponding surgical procedures, are occurring with increasing frequency as identified by a review of recent surgical trends. Concerns have grown in recent years regarding the longevity of results following microfracture, with a shift toward cartilage restoration procedures in recent years. This case report describes 2 cases of acute failure following the use of commercially available osteochondral allograft plugs used for the treatment of osteochondral defects of the distal femur. In both cases the chondral surface of the plug delaminated from the underlying cancellous bone, resulting in persistent pain and swelling requiring reoperation and removal of the loose fragments. Caution should be employed when considering use of these plugs for the treatment of osteochondral lesions, as similar outcomes have not been noted with other cartilage restoration techniques. PMID:27688840

  8. TREATMENT OF OSTEOCHONDRAL LESIONS OF THE TALUS BY MEANS OF THEARTHROSCOPY-ASSISTED MICROPERFORATION TECHNIQUE

    PubMed Central

    de Lima, Everton; de Queiroz, Felipe; Lopes, Osmar Valadão; Spinelli, Leandro de Freitas

    2015-01-01

    Objective: To evaluate patients affected by osteochondral fractures of the talus who were treated surgically by means of arthroscopy-assisted microperforation. Methods: A retrospective study was carried out on 24 patients with osteochondral lesions of the talus who underwent microperforation assisted by videoarthroscopy of the ankle. They were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score system before and after the operation. Results: There were 19 men and 5 women, with a mean age of 35.3 years (minimum of 17 years and maximum of 54 years). The minimum follow-up was two years (maximum of 39 months). All the patients showed an improvement in AOFAS score after surgery, with an average improvement of around 22.5 points. Conclusion: Videoarthroscopy-assisted microperforation is a good option for treating osteochondral lesions of the talus and provides good functional results. PMID:27027076

  9. Bilateral osteochondritis dissecans of the lateral trochlea of the femur: a case report.

    PubMed

    Takahashi, Yoshimasa; Nawata, Koji; Hashiguchi, Hirokazu; Kawaguchi, Kei; Yamasaki, Daisuke; Tanaka, Hidetoshi

    2008-05-01

    Osteochondritis dissecans of the bilateral trochlea of femur is unusual case for orthopedic surgeon. The patient was a healthy 15-year-old male with symptomatic osteochondritis dissecans of the bilateral distal lateral femoral condyle of the trochlea. A surgery on the bilateral knee joints was performed simultaneously. The osteochondral free fragment of the right knee was resected by a minimum open surgery after arthroscopic evaluation. In the left knee the fragment was stabilized with multiple cortical bone pegs harvested from the proximal tibia. The surgery was successful, and the patient was able to play basketball 3 months postoperatively. The course of the right knee is currently under careful observation because of the possibility of recurrence. The left knee has remained in an excellent condition for 18 months following surgery with bone pegs.

  10. Results of Osteochondral Autologous Transplantation in the Knee

    PubMed Central

    Muller, Sandra; Breederveld, Roelf S.; Tuinebreijer, Wim E.

    2010-01-01

    Repair of full thickness defects of articular cartilage in the knee is difficult but important to prevent progression to osteoarthritis. The purpose of this retrospective study was to evaluate the clinical results of Osteochondral Autograft Transplant System (OATS) treatment for articular defects of the knee. Between 1999 and 2005, 15 knees (14 patients) were treated by the OATS technique. Age ranged from 27 to 52 years. Cartilage defects were up to 3.75 cm2. The mean follow-up was 42 months. Knee function was assessed by the Lysholmscore and International Knee Documentation Committee (IKDC) Subjective Knee Form. Six patients scored good or excellent. No patient had knee instability. Twelve of 13 patients returned to sports at an intermediate or high level. The subjective assessment score (0-10) changed from 4.7 before operation to 7.2 afterward (P=0.007). The OATS-technique resulted in a decrease in symptoms in patients with localized articular cartilage defects. We consider the OATS technique to be an appropriate treatment for cartilage defects to prevent progression of symptoms. PMID:20361003

  11. Chondroblastoma of the Knee Treated with Resection and Osteochondral Allograft Reconstruction

    PubMed Central

    Fitzgerald, Judd; Broehm, Cory; Treme, Gehron

    2014-01-01

    Case. This case report describes the operative management of 16-year-old male with a symptomatic chondroblastoma of the distal femur with breach of the chondral surface. Following appropriate imaging and core needle biopsy, the diagnosis was confirmed histologically. The patient then underwent intralesional curettage and osteochondral allograft reconstruction of the defect. At one-year follow-up the patient was pain-free and has obtained excellent range of motion. There is radiographic evidence of allograft incorporation and no evidence of local recurrence. Conclusion. Osteochondral allograft reconstruction is an effective option following marginal resection and curettage of chondroblastoma involving the chondral surface of the distal femur. PMID:25548701

  12. Chondroblastoma of the knee treated with resection and osteochondral allograft reconstruction.

    PubMed

    Fitzgerald, Judd; Broehm, Cory; Chafey, David; Treme, Gehron

    2014-01-01

    Case. This case report describes the operative management of 16-year-old male with a symptomatic chondroblastoma of the distal femur with breach of the chondral surface. Following appropriate imaging and core needle biopsy, the diagnosis was confirmed histologically. The patient then underwent intralesional curettage and osteochondral allograft reconstruction of the defect. At one-year follow-up the patient was pain-free and has obtained excellent range of motion. There is radiographic evidence of allograft incorporation and no evidence of local recurrence. Conclusion. Osteochondral allograft reconstruction is an effective option following marginal resection and curettage of chondroblastoma involving the chondral surface of the distal femur.

  13. Chondroblastoma of the knee treated with resection and osteochondral allograft reconstruction.

    PubMed

    Fitzgerald, Judd; Broehm, Cory; Chafey, David; Treme, Gehron

    2014-01-01

    Case. This case report describes the operative management of 16-year-old male with a symptomatic chondroblastoma of the distal femur with breach of the chondral surface. Following appropriate imaging and core needle biopsy, the diagnosis was confirmed histologically. The patient then underwent intralesional curettage and osteochondral allograft reconstruction of the defect. At one-year follow-up the patient was pain-free and has obtained excellent range of motion. There is radiographic evidence of allograft incorporation and no evidence of local recurrence. Conclusion. Osteochondral allograft reconstruction is an effective option following marginal resection and curettage of chondroblastoma involving the chondral surface of the distal femur. PMID:25548701

  14. Single-layer MoS2 nanosheet grafted upconversion nanoparticles for near-infrared fluorescence imaging-guided deep tissue cancer phototherapy

    NASA Astrophysics Data System (ADS)

    Han, Jianyu; Xia, Hongping; Wu, Yafeng; Kong, Shik Nie; Deivasigamani, Amudha; Xu, Rong; Hui, Kam M.; Kang, Yuejun

    2016-04-01

    A multifunctional nanostructure is prepared by covalently grafting upconversion nanoparticles (UCNPs) with chitosan functionalized MoS2 (MoS2-CS) and folic acid (FA) and then loading phthalocyanine (ZnPc) on the surface of MoS2, which integrates photodynamic therapy (PDT) with photothermal therapy (PTT) and upconversion luminescence imaging into one system for enhanced antitumor efficiency.A multifunctional nanostructure is prepared by covalently grafting upconversion nanoparticles (UCNPs) with chitosan functionalized MoS2 (MoS2-CS) and folic acid (FA) and then loading phthalocyanine (ZnPc) on the surface of MoS2, which integrates photodynamic therapy (PDT) with photothermal therapy (PTT) and upconversion luminescence imaging into one system for enhanced antitumor efficiency. Electronic supplementary information (ESI) available: Experimental details and figures. See DOI: 10.1039/c6nr00150e

  15. Postoperative irradiation of fresh autogenic cancellous bone grafts

    SciTech Connect

    Schwartz, H.C.; Leake, D.L.; Kagan, A.R.; Snow, H.; Pizzoferrato, A.

    1986-01-01

    Discontinuity defects were created in the mandibles of dogs and then reconstructed immediately with fresh autogenic cancellous bone grafts and Dacron-urethane prostheses. The grafts were irradiated to a total dose of 5000 rads after waiting intervals of between 3 and 12 weeks. Nonirradiated grafts served as controls. The grafts were evaluated clinically, radiographically, and histologically. There was complete incorporation of all grafts, regardless of the interval between surgery and radiotherapy. There were no soft-tissue complications. The controls were distinguishable from the irradiated grafts only by the presence of hematopoietic bone marrow. Fibrofatty marrow was observed in the irradiated grafts. Theoretical support for this technique is found in the biology of cancellous bone grafting and the pathology of radiation injury. In view of the difficulties associated with mandibular bone grafting in preoperatively irradiated patients, a new method of reconstructing selected cancer patients who require both mandibular resection and radiotherapy is suggested.

  16. Synthetic grafts for anterior cruciate ligament reconstruction.

    PubMed

    Longo, Umile Giuseppe; Rizzello, Giacomo; Berton, Alessandra; Fumo, Caterina; Maltese, Ludovica; Khan, Wasim S; Denaro, Vincenzo

    2013-11-01

    Several artificial biomaterials are available as ligament grafts. No ideal prosthesis mimicking natural human tissue have been found to date. The emerging field of tissue engineering holds the promise to use artificial ligaments as a viable alternative to the patellar or hamstring tendon autografts. Preliminary studies support the idea that these biomaterials have the ability to provide an alternative for autogenous grafts. However, no definitive conclusions have been found. Additionally, the incidence of postoperative complications varies within different studies. Prospective investigations are required to better understand the potential of artificial biomaterials as ligament grafts.

  17. Development of Novel Three-Dimensional Printed Scaffolds for Osteochondral Regeneration

    PubMed Central

    Holmes, Benjamin; Zhu, Wei; Li, Jiaoyan; Lee, James D.

    2015-01-01

    As modern medicine advances, various methodologies are being explored and developed in order to treat severe osteochondral defects in joints. However, it is still very challenging to cure the osteochondral defects due to their poor inherent regenerative capacity, complex stratified architecture, and disparate biomechanical properties. The objective of this study is to create novel three-dimensional (3D) printed osteochondral scaffolds with both excellent interfacial mechanical properties and biocompatibility for facilitating human bone marrow mesenchymal stem cell (MSC) growth and chondrogenic differentiation. For this purpose, we designed and 3D printed a series of innovative bi-phasic 3D models that mimic the osteochondral region of articulate joints. Our mechanical testing results showed that our bi-phasic scaffolds with key structures have enhanced mechanical characteristics in compression (a maximum Young's modulus of 31 MPa) and shear (a maximum fracture strength of 5768 N/mm2) when compared with homogenous designs. These results are also correlated with numerical simulation. In order to improve their biocompatibility, the scaffolds' surfaces were further modified with acetylated collagen (one of the main components in osteochondral extracellular matrix). MSC proliferation results demonstrated that incorporation of a collagen, along with biomimetically designed micro-features, can greatly enhance MSC growth after 5 days in vitro. Two weeks' chondrogenic differentiation results showed that our novel scaffolds (dubbed “key” scaffolds), both with and without surface collagen modification, displayed enhanced chondrogenesis (e.g., 130%, 114%, and 236% increases in glycosaminoglycan, type II collagen deposition, and total protein content on collagen-modified key scaffolds when compared with homogeneous controls). PMID:25088966

  18. A rare case of bilateral non-weight bearing posterior aspect of lateral femoral condyle osteochondral fracture and its management.

    PubMed

    Shaikh, Aamir Hassan; Stanclik, Jaroslaw; Murphy, Paul G D

    2014-01-01

    Osteochondral fracture of the lateral femoral condyle can be a real challenging injury to diagnose on initial presentation. The authors report a rare case of bilateral involvement of posterior aspect of lateral femoral condyle osteochondral fracture in a young 15-year-old boy. This was managed with excision of these osteochondral fragments, as the site involved was on the posterior non-weight bearing area of the femur along with chronicity of the injury dictating excision as a reasonable choice of management. Good outcome for such injury is based on an early diagnosis and prompt treatment along with an early rehabilitation for such cases. Our patient has an excellent 2 years outcome with a Knee Society score of 95 after undergoing excision of these osteochondral fragments in both knees in succession.

  19. Detection of intraarticular loose osteochondral fragments by double-contrast wrist arthrography. A case report of a basketball injury.

    PubMed

    Tehranzadeh, J; Labosky, D A

    1984-01-01

    Gravity was used in a case of double-contrast wrist arthrography to demonstrate the intraarticular loose nature of osteochondral fracture fragments. These calcified loose bodies were successfully removed surgically.

  20. Osteochondritis dissecans of the humeral capitellum. Diagnosis and treatment.

    PubMed

    Bradley, J P; Petrie, R S

    2001-07-01

    be chosen based on the size of the lesion and the integrity of the subchondral bone. Subchondral drilling and microfracture can only resurface defects and cannot reconstitute subchondral bone. Autologous chondrocyte implantation has limited ability to address subchondral bone loss, whereas autograft and allograft osteochondral transplantation can restore subchondral bone. Most authors would agree that there is no role currently for reduction and fixation of long-standing, free loose bodies. No consensus exists regarding acute dislodging of an in situ loose fragment. Long-term results after radiographic changes are present suggest a degenerative course in about half the patients. Whether the newer techniques of cartilage resurfacing will significantly impact the natural history of this process remains to be seen.

  1. RGD-conjugated copolymer incorporated into composite of poly(lactide-co-glycotide) and poly(L-lactide)-grafted nanohydroxyapatite for bone tissue engineering.

    PubMed

    Zhang, Peibiao; Wu, Haitao; Wu, Han; Lù, Zhongwen; Deng, Chao; Hong, Zhongkui; Jing, Xiabin; Chen, Xuesi

    2011-07-11

    Various surface modification methods of RGD (Arg-Gly-Asp) peptides on biomaterials have been developed to improve cell adhesion. This study aimed to examine a RGD-conjugated copolymer RGD/MPEG-PLA-PBLG (RGD-copolymer) for its ability to promote bone regeneration by mixing it with the composite of poly(lactide-co-glycotide) (PLGA) and hydroxyapatite nanoparticles surface-grafted with poly(L-lactide) (g-HAP). The porous scaffolds were prepared using solvent casting/particulate leaching method and grafted to repair the rabbit radius defects after seeding with autologous bone marrow mesenchymal cells (MSCs) of rabbits. After incorporation of RGD-copolymer, there were no significant influences on scaffold's porosity and pore size. Nitrogen of RGD peptide, and calcium and phosphor of g-HAP could be exposed on the surface of the scaffold simultaneously. Although the cell viability of its leaching liquid was 92% that was lower than g-HAP/PLGA, its cell adhesion and growth of 3T3 and osteoblasts were promoted significantly. The greatest increment in cell adhesion ratios (131.2-157.1% higher than g-HAP/PLGA) was observed when its contents were 0.1-1 wt % but only at 0.5 h after cell seeding. All the defects repaired with the implants were bridged after 24 weeks postsurgery, but the RGD-copolymer contained composite had larger new bone formation and better fusion interface. The composites containing RGD-copolymer enhanced bone ingrowth but presented more woven bones than others. The combined application of RGD-copolymer and bone morphological protein 2 (BMP-2) exhibited the best bone healing quality and was recommended as an optimal strategy for the use of RGD peptides. PMID:21604718

  2. RGD-conjugated copolymer incorporated into composite of poly(lactide-co-glycotide) and poly(L-lactide)-grafted nanohydroxyapatite for bone tissue engineering.

    PubMed

    Zhang, Peibiao; Wu, Haitao; Wu, Han; Lù, Zhongwen; Deng, Chao; Hong, Zhongkui; Jing, Xiabin; Chen, Xuesi

    2011-07-11

    Various surface modification methods of RGD (Arg-Gly-Asp) peptides on biomaterials have been developed to improve cell adhesion. This study aimed to examine a RGD-conjugated copolymer RGD/MPEG-PLA-PBLG (RGD-copolymer) for its ability to promote bone regeneration by mixing it with the composite of poly(lactide-co-glycotide) (PLGA) and hydroxyapatite nanoparticles surface-grafted with poly(L-lactide) (g-HAP). The porous scaffolds were prepared using solvent casting/particulate leaching method and grafted to repair the rabbit radius defects after seeding with autologous bone marrow mesenchymal cells (MSCs) of rabbits. After incorporation of RGD-copolymer, there were no significant influences on scaffold's porosity and pore size. Nitrogen of RGD peptide, and calcium and phosphor of g-HAP could be exposed on the surface of the scaffold simultaneously. Although the cell viability of its leaching liquid was 92% that was lower than g-HAP/PLGA, its cell adhesion and growth of 3T3 and osteoblasts were promoted significantly. The greatest increment in cell adhesion ratios (131.2-157.1% higher than g-HAP/PLGA) was observed when its contents were 0.1-1 wt % but only at 0.5 h after cell seeding. All the defects repaired with the implants were bridged after 24 weeks postsurgery, but the RGD-copolymer contained composite had larger new bone formation and better fusion interface. The composites containing RGD-copolymer enhanced bone ingrowth but presented more woven bones than others. The combined application of RGD-copolymer and bone morphological protein 2 (BMP-2) exhibited the best bone healing quality and was recommended as an optimal strategy for the use of RGD peptides.

  3. 3D Printing and Biofabrication for Load Bearing Tissue Engineering.

    PubMed

    Jeong, Claire G; Atala, Anthony

    2015-01-01

    Cell-based direct biofabrication and 3D bioprinting is becoming a dominant technological platform and is suggested as a new paradigm for twenty-first century tissue engineering. These techniques may be our next step in surpassing the hurdles and limitations of conventional scaffold-based tissue engineering, and may offer the industrial potential of tissue engineered products especially for load bearing tissues. Here we present a topically focused review regarding the fundamental concepts, state of the art, and perspectives of this new technology and field of biofabrication and 3D bioprinting, specifically focused on tissue engineering of load bearing tissues such as bone, cartilage, osteochondral and dental tissue engineering.

  4. 3D Printing and Biofabrication for Load Bearing Tissue Engineering.

    PubMed

    Jeong, Claire G; Atala, Anthony

    2015-01-01

    Cell-based direct biofabrication and 3D bioprinting is becoming a dominant technological platform and is suggested as a new paradigm for twenty-first century tissue engineering. These techniques may be our next step in surpassing the hurdles and limitations of conventional scaffold-based tissue engineering, and may offer the industrial potential of tissue engineered products especially for load bearing tissues. Here we present a topically focused review regarding the fundamental concepts, state of the art, and perspectives of this new technology and field of biofabrication and 3D bioprinting, specifically focused on tissue engineering of load bearing tissues such as bone, cartilage, osteochondral and dental tissue engineering. PMID:26545741

  5. Technique in Cleft Rhinoplasty: The Foundation Graft.

    PubMed

    Gassner, Holger G; Schwan, Franziska; Haubner, Frank; Suárez, Gustavo A; Vielsmeier, Veronika

    2016-04-01

    Secondary cleft rhinoplasty represents a particular surgical challenge. The authors have identified the deficit in skeletal projection of the cleft-sided piriform rim as an important contributor to the pathology. A graft is described to augment the piriform crest on the cleft side. This foundation graft is suture fixated to the piriform crest after complete release of all soft tissue attachments to the alar base. The foundation graft is articulated with a long alar strut graft, which allows for powerful projection of the cleft-sided nasal tip. An advancement flap of vestibular skin is described to correct the vestibular stenosis. A transplant of diced cartilage in fascia is added to augment maxillary soft tissue volume. Subjective and objective measures of form and function are presented in a retrospective series of five cases, illustrating the efficacy of the techniques described. PMID:27097143

  6. Osteochondral Regeneration: Tuning Cell Differentiation into a 3D Scaffold Presenting a Pore Shape Gradient for Osteochondral Regeneration (Adv. Healthcare Mater. 14/2016).

    PubMed

    Di Luca, Andrea; Lorenzo-Moldero, Ivan; Mota, Carlos; Lepedda, Antonio; Auhl, Dietmar; Van Blitterswijk, Clemens; Moroni, Lorenzo

    2016-07-01

    A combination of human mesenchymal stem cells with additive manufacturing technology for the fabrication of scaffolds with instructive properties is presented by Lorenzo Moroni and co-workers on page 1753. This new fiber deposition pattern allows the generation of pores of different shapes within the same construct. The most rhomboidal pore geometry sustained enhances alkaline phosphatase activity and osteogenic related genes expression with respect to the other gradient zones when the gradient scaffold is cultured in a medium supporting both osteogenic and chondrogenic differentiation. This may contribute to enhance osteochondral regeneration in orthopedic treatments. PMID:27436107

  7. Electrostrictive Graft Elastomers

    NASA Technical Reports Server (NTRS)

    Su, Ji (Inventor); Harrison, Joycelyn S. (Inventor); St.Clair, Terry L. (Inventor)

    2003-01-01

    An electrostrictive graft elastomer has a backbone molecule which is a non-crystallizable, flexible macromolecular chain and a grafted polymer forming polar graft moieties with backbone molecules. The polar graft moieties have been rotated by an applied electric field, e.g., into substantial polar alignment. The rotation is sustained until the electric field is removed. In another embodiment, a process for producing strain in an elastomer includes: (a) providing a graft elastomer having a backbone molecule which is a non-crystallizable, flexible macromolecular chain and a grafted polymer forming polar graft moieties with backbone molecules; and (b) applying an electric field to the graft elastomer to rotate the polar graft moieties, e.g., into substantial polar alignment.

  8. Biomaterials in Maxillofacial Surgery: Membranes and Grafts

    PubMed Central

    Rodella, Luigi F.; Favero, Gaia; Labanca, Mauro

    2011-01-01

    Today, significant differences in the use of biomaterials (membranes and grafts) of animal or synthetic origin have yet to be reported. Nevertheless, some evidences suggest that synthetic materials have a lower risk of disease transmission. This review aims to assess the available informations on regenerative bone technique using reasorbable membranes and bone grafts. In particular, biocompatibility, immunological response, tissue reaction, reabsorption time and histological features of materials daily use in dentistry and in maxillofacial surgery were emphasized. PMID:23675225

  9. Intra-articular osteoid osteoma at the femoral trochlea treated with osteochondral autograft transplantation

    PubMed Central

    Leeman, Joshua J; Motamedi, Daria; Wildman-Tobriner, Ben; O’Donnell, Richard J; Link, Thomas M

    2016-01-01

    We present the case of an intra-articular osteoid osteoma at the femoral trochlea. Intra-articular osteoid osteoma can present a diagnostic challenge both clinically and with imaging because it presents differently from the classic cortical osteoid osteoma. Given the lesion’s proximity to overlying cartilage, the patient underwent resection of the lesion with osteochondral autograft transplantation at the surgical defect. A comprehensive literature review and discussion of intra-articular osteoma will be provided. PMID:27761182

  10. Percutaneous CT-Guided Treatment of Osteochondritis Dissecans of the Sacroiliac Joint

    SciTech Connect

    Becce, Fabio; Mouhsine, Elyazid; Mosimann, Pascal John; Anaye, Anass; Letovanec, Igor; Theumann, Nicolas

    2012-08-15

    Osteochondritis dissecans (OCD) is a joint disorder that affects the articular cartilage and subchondral bone, most commonly at the knee. OCD of the sacroiliac joint is extremely rare. Management of OCD remains controversial, and surgery is often needed, especially when conservative treatment fails. We present a rare case of OCD involving the left sacroiliac joint successfully treated by percutaneous computed tomography-guided retrograde drilling and debridement.

  11. Human adipose CD34+ CD90+ stem cells and collagen scaffold constructs grafted in vivo fabricate loose connective and adipose tissues.

    PubMed

    Ferraro, Giuseppe A; De Francesco, Francesco; Nicoletti, Gianfranco; Paino, Francesca; Desiderio, Vincenzo; Tirino, Virginia; D'Andrea, Francesco

    2013-05-01

    Stem cell based therapies for the repair and regeneration of various tissues are of great interest for a high number of diseases. Adult stem cells, instead, are more available, abundant and harvested with minimally invasive procedures. In particular, mesenchymal stem cells (MSCs) are multi-potent progenitors, able to differentiate into bone, cartilage, and adipose tissues. Human adult adipose tissue seems to be the most abundant source of MSCs and, due to its easy accessibility; it is able to give a considerable amount of stem cells. In this study, we selected MSCs co-expressing CD34 and CD90 from adipose tissue. This stem cell population displayed higher proliferative capacity than CD34(-) CD90(-) cells and was able to differentiate in vitro into adipocytes (PPARγ(+) and adiponectin(+)) and endothelial cells (CD31(+) VEGF(+) Flk1(+)). In addition, in methylcellulose without VEGF, it formed a vascular network. The aim of this study was to investigate differentiation potential of human adipose CD34(+) /CD90(+) stem cells loaded onto commercial collagen sponges already used in clinical practice (Gingistat) both in vitro and in vivo. The results of this study clearly demonstrate that human adult adipose and loose connective tissues can be obtained in vivo, highlighting that CD34(+) /CD90 ASCs are extremely useful for regenerative medicine.

  12. Design and development of multilayer vascular graft

    NASA Astrophysics Data System (ADS)

    Madhavan, Krishna

    2011-07-01

    strength, showed that the multilayer graft possessed properties mimicking those of native vessels. Achieving these FDA-required functional properties is essential because they play critical roles in graft performances in vivo such as thrombus formation, occlusion, healing, and bleeding. In addition, cell studies and animal studies have been performed on the multilayer graft. Our results show that the multilayer graft support mimetic vascular culture of cells and the acellular graft serves as an artery equivalent in vivo to sustain the physiological conditions and promote appropriate cellular activity. In conclusion, the newly-developed hybrid multilayer graft provides a proper balance of biomechanical and biochemical properties and demonstrates the potential for the use of vascular tissue engineering and regeneration.

  13. Grafting techniques for Peyronie’s disease

    PubMed Central

    2016-01-01

    Peyronie’s disease (PD) is a benign fibrotic condition of the penile tunica albuginea. PD can be associated with penile pain, curvature, shortening, and erectile dysfunction (ED). The predominant and most bothersome symptom in affected patients is penile curvature, which can lead to inability to have sexual intercourse. In such cases, surgical correction of the curvature may be required. Plication techniques to correct curvature can cause penile shortening and therefore are generally reserved for curvatures <60°. Penile prosthesis implantation with simultaneous correction of curvature by various means is recommended in PD patients with ED not responding to medical therapy. Grafting techniques are the preferred surgical treatment in patients with penile curvatures >60°, short penis, or hourglass deformity. Patients scheduled for grafting surgery are required to have satisfactory erectile rigidity preoperatively. There are various grafting materials that can be used for closure of the tunica albuginea defect following plaque incision/excision. Both autologous and non-autologous grafts have been used for PD reconstructive surgery, and each graft has its advantages and disadvantages. Novel grafting materials are presented and discussed in this review. A major advantage of the available “off-the-shelf” grafts is that there is no harvesting from a donor site and, thus, morbidity is reduced, and operative times are minimized. Further investigations in regard to tissue-engineered grafts to improve surgical handling and postoperative outcomes are ongoing. Surgeon experience, careful patient selection, patient preference and type of penile deformity affect the choice of graft. This review summarizes the literature within the past 5 years regarding grafting techniques in PD. Surgical outcomes and limitations of grafting techniques are reported. A major objective of this review is dedicated to preoperative considerations and indications for grafting procedures, with

  14. A review of terminology for equine juvenile osteochondral conditions (JOCC) based on anatomical and functional considerations.

    PubMed

    Denoix, J-M; Jeffcott, L B; McIlwraith, C W; van Weeren, P R

    2013-07-01

    This manuscript describes a new classification of the various joint-related lesions that can be seen in the young, growing horse based on their anatomical and functional aetiopathogenesis. Juvenile osteochondral conditions (JOCC) is a term that brings together specific disorders according to their location in the joint and their biomechanical origin. When a biomechanical insult affects the process of endochondral ossification different types of osteochondrosis (OC) lesions may occur, including osteochondral fragmentation of the articular surface or of the periarticular margins, or the formation of juvenile subchondral bone cysts. In severe cases, osteochondral collapse of the articular surface or the epiphysis or even an entire small bone may occur. Tension on ligament attachments may cause avulsion fractures of epiphyseal (or metaphyseal) ossifying bone, which are classified as JOCC, but do not result from a disturbance of the process of endochondral ossification and are not therefore classified as a form of OC. The same applies to 'physitis' which can result from damage to the physeal growth plate.

  15. Intentional reim plantation of a tooth with severe periodontal involvement using enamel matrix derivative in combination with guided tissue regeneration and bone grafting: a case report.

    PubMed

    Sugai, Kenji; Sato, Shuichi; Suzuki, Kuniharu; Ito, Koichi

    2008-02-01

    This case involved the intentional reimplantation of a tooth with severe periodontal involvement using regenerative therapies. The maxillary left central incisor was intentionally extracted, enamel matrix derivative (EMD) was applied, and the tooth was repositioned accurately. The bone defect was filled with a xenograft and a demineralized freeze-dried bone allograft, and a guided tissue regeneration membrane was adapted over the site. After 5 years, a reduction in probing depth and a gain in clinical attachment were observed. Conventional radiographs and cone-beam computerized tomographs showed hard tissue improvement. Favorable clinical results were obtained with reimplantation with applied EMD, combined with regenerative therapies, for treating a tooth with severe periodontal involvement.

  16. The natural history of bacterial biofilm graft infection.

    PubMed

    Bergamini, T M; Corpus, R A; Brittian, K R; Peyton, J C; Cheadle, W G

    1994-05-01

    A mouse model was developed to study the natural history of vascular prosthetic graft infection due to Staphylococcus epidermidis. Graft infections were established in the back subcutaneous tissue of 46 mice by implantation of Dacron prostheses colonized in vitro with slime-producing S. epidermidis to form an adherent bacterial biofilm [1.7 x 10(7) colony forming units (CFU)/cm2 graft]. Control animals (n = 16) had implantation of sterile Dacron prostheses. None of the control animals developed a graft infection or graft-cutaneous sinus tract. All study animals developed a biofilm graft infection with typical anatomic (perigraft abscess), microbiologic (low bacterial concentration in surface biofilm), and immunologic (normal white blood count) characteristics. A graft-cutaneous sinus tract developed in a significantly higher number of mice with infected grafts by 8-10 weeks (9 of 21) compared to infected grafts explanted at 2 and 4-6 weeks (1 of 25, P < 0.01) and controls (0 of 16, P < 0.03). By 8-10 weeks, 2 animals had no signs of graft infection and the S. epidermidis study strain was not recoverable from 7 grafts. The natural history of bacterial biofilm vascular prostheses infection in the mouse model was similar to that in man, provoking a chronic inflammatory process curiously presenting as a perigraft abscess or graft-cutaneous sinus tract.

  17. Engineering Orthopedic Tissue Interfaces

    PubMed Central

    Yang, Peter J.

    2009-01-01

    While a wide variety of approaches to engineering orthopedic tissues have been proposed, less attention has been paid to the interfaces, the specialized areas that connect two tissues of different biochemical and mechanical properties. The interface tissue plays an important role in transitioning mechanical load between disparate tissues. Thus, the relatively new field of interfacial tissue engineering presents new challenges—to not only consider the regeneration of individual orthopedic tissues, but also to design the biochemical and cellular composition of the linking tissue. Approaches to interfacial tissue engineering may be distinguished based on if the goal is to recreate the interface itself, or generate an entire integrated tissue unit (such as an osteochondral plug). As background for future efforts in engineering orthopedic interfaces, a brief review of the biology and mechanics of each interface (cartilage–bone, ligament–bone, meniscus–bone, and muscle–tendon) is presented, followed by an overview of the state-of-the-art in engineering each tissue, including advances and challenges specific to regenerating the interfaces. PMID:19231983

  18. Do Stem Cells Have an Effect When We Fat Graft?

    PubMed

    Rinker, Brian D; Vyas, Krishna S

    2016-06-01

    Fat grafting has become a widely accepted modality of soft tissue restoration and has found applications in many areas of aesthetic and reconstructive plastic surgery. Numerous claims have been made regarding the regenerative effects of fat grafting on the recipient bed. The purpose of this paper is to survey the available literature to answer the question of whether fat grafting has a positive effect on the surrounding tissues. It has been convincingly demonstrated that fat grafts contain viable adipose-derived stem cells (ASCs). The fate of these cells is determined by the microenvironment of the recipient bed, but animal studies have shown that a large fraction of ASCs survive engraftment. Numerous clinical studies have demonstrated the positive effects of fat grafting on recipient tissues. Improvement in validated scar scores as well as scar stiffness measurements have been documented after fat grafting of burn scars. Fat grafting has also been convincingly demonstrated to improve the quality of irradiated tissues, as measured by validated clinical scales and staged histology. It is ultimately unclear whether ASCs are responsible for these effects, but the circumstantial evidence is weighty. Fat grafting is effective for volumizing and improving skin quality in the setting of radiation, burns, and other scars. The observed effects are likely due to ASCs, but the evidence does not support the routine use of ASC-enriched fat grafts.

  19. Bone grafts in dentistry

    PubMed Central

    Kumar, Prasanna; Vinitha, Belliappa; Fathima, Ghousia

    2013-01-01

    Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation. PMID:23946565

  20. [Vascular graft prosthesis].

    PubMed

    Chakfé, N; Dieval, F; Thaveau, F; Rinckenbach, S; Hassani, O; Camelot, G; Durand, B; Kretz, J-G

    2004-06-01

    Performed since the 1950s, vascular grafting has opened modern era of vascular surgery. Autologous venous grafts are of first choice for revascularisation of small arteries. Synthetic grafts are mainly modelled using microporous polytetrafluoroethylene or terephtalate polyethylene. These prosthesis are mainly used for revascularization of medium and large size arteries. PMID:15220107

  1. Effect of He-Ne laser radiation on healing of osteochondral defect in rabbit: a histological study.

    PubMed

    Bayat, Mohammad; Javadieh, Farshad; Dadpay, Masoomeh

    2009-01-01

    This study examined the influence of low-level laser therapy (LLLT) on the healing of a large osteochondral defect in rabbits.An osteochondral defect with 5 mm diameter was surgically induced in the right femoral patellar groove of 48 adult male rabbits. They were divided into a control and an experimental group. The rabbits were treated at 2, 4, 8, and 16 weeks after surgery, with six rabbits in each study period being tested at each biweekly period. The experimental group received LLLT with a helium-neon (He-Ne) laser (632.8 nm, 10 mW) of 148.4 J/cm(2) three times a week, and the control group received placebo LLLT with equipment switched off. The defects were examined macroscopically and microscopically. The results of the histological examination 2 weeks after surgery showed that the osteochondral healing of the control group was significantly accelerated compared with that of the experimental group. However, the osteochondral healing of the experimental group 4 weeks and 16 weeks after surgery showed that healing accelerated significantly compared with that of the control group. The conclusion was that LLLT with an He-Ne laser could not significantly accelerate healing of a large osteochondral defect in rabbits of the experimental group compared with that of the control group throughout the duration of the present study. PMID:20437320

  2. Rotational osteoplasty and bioabsorbable polylactate pin fixation in Pipkin type 2 fracture with acute osteochondral defect: a case report.

    PubMed

    Maluta, Tommaso; Micheloni, Gian Mario; Sandri, Andrea; Regis, Dario; Costanzo, Alessandro; Magnan, Bruno

    2016-01-01

    Pipkin fractures are relative rare high-energy lesions characterized by an intra-articular fracture of the femoral head after posterior hip dislocation. Early anatomic reduction and stable fixation are the main goals of treatment. This case evaluates the outcome of managing Pipkin type 2 fracture with acute osteochondral defect of the femoral head using "rotational osteoplasty" and bioabsorbable polylactate pin fixation. 24-year-old male patient was involved in a motorcycle accident, suffering from a left hip fracture-dislocation, and pelvic Computed Tomography revealed a Pipkin type 2 lesion. An open urgent treatment was performed. After  anatomic reduction of the femoral head fragment a large osteochondral defect in the anterior-superior weight bearing surface was evident. The pattern of the fracture allowed us to perform a "rotational osteoplasty" including rotation of the femoral head fragment, to obtain an osteochondral cartilage congruence of the anterior-superior surface. Stable fixation was obtained by three bioabsorbable polylactate pins. At four-year follow up the patient had an excellent outcome and Magnetic Resonance Imaging (MRI) showed fracture healing, minimal signs of arthritis, excluding osteonecrosis of the femoral head. The reported case confirms that Pipkin fractures are very insidious surgical urgencies. In selected cases, "rotational osteoplasty" may be an alternative to osteochondral transplant for acute osteochondral defect of the femoral head. Bioabsorbable polylactate pin fixation allowed us to have a stable fixation evaluating the bone healing process and vitality of femoral head by MRI. PMID:27104330

  3. Development of in vivo tissue-engineered microvascular grafts with an ultra small diameter of 0.6 mm (MicroBiotubes): acute phase evaluation by optical coherence tomography and magnetic resonance angiography.

    PubMed

    Ishii, Daizo; Enmi, Jun-Ichiro; Moriwaki, Takeshi; Ishibashi-Ueda, Hastue; Kobayashi, Mari; Iwana, Shinichi; Iida, Hidehiro; Satow, Tetsu; Takahashi, Jun C; Kurisu, Kaoru; Nakayama, Yasuhide

    2016-09-01

    Biotubes, i.e., in vivo tissue-engineered connective tubular tissues, are known to be effective as vascular replacement grafts with a diameter greater than several millimeters. However, the performance of biotubes with smaller diameters is less clear. In this study, MicroBiotubes with diameters <1 mm were prepared, and their patency was evaluated noninvasively by optical coherence tomography (OCT) and magnetic resonance angiography (MRA). MicroBiotube molds, containing seven stainless wires (diameter 0.5 mm) covered with silicone tubes (outer diameter 0.6 mm) per mold, were embedded into the dorsal subcutaneous pouches of rats. After 2 months, the molds were harvested with the surrounding capsular tissues to obtain seven MicroBiotubes (internal diameter 0.59 ± 0.015 mm, burst pressure 4190 ± 1117 mmHg). Ten-mm-long MicroBiotubes were allogenically implanted into the femoral arteries of rats by end-to-end anastomosis. Cross-sectional OCT imaging demonstrated the patency of the MicroBiotubes immediately after implantation. In a 1-month follow-up MRA, high patency (83.3 %, n = 6) was observed without stenosis, aneurysmal dilation, or elongation. Native-like vascular structure was reconstructed with completely endothelialized luminal surfaces, mesh-like elastin fiber networks, regular circumferential orientation of collagen fibers, and α-SMA-positive cells. Although the long-term patency of MicroBiotubes still needs to be confirmed, they may be useful as an alternative ultra-small-caliber vascular substitute. PMID:27003431

  4. Treatment of osteochondral lesions of the talus with autologous collagen-induced chondrogenesis: clinical and magnetic resonance evaluation at one-year follow-up

    PubMed Central

    USUELLI, FEDERICO GIUSEPPE; GRASSI, MIRIAM; MANZI, LUIGI; GUARRELLA, VINCENZO; BOGA, MICHELE; DE GIROLAMO, LAURA

    2016-01-01

    Purpose the aim of this study is to report the clinical and imaging results recorded by a series of patients in whom osteochondral lesions of the talus (OLTs) were repaired using the autologous collagen-induced chondrogenesis (ACIC) technique with a completely arthroscopic approach. Methods nine patients (mean age 37.4±10 years) affected by OLTs (lesion size 2.1±0.9 cm2) were treated with the ACIC technique. The patients were evaluated clinically both preoperatively and at 12 months after surgery using the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) and a visual analog scale (VAS). For morphological evaluation, the magnetic resonance observation of cartilage repair tissue (MOCART) score was used. Results the AOFAS score improved from 51.4±11.6 preoperatively to 71.8±20.6 postoperatively, while the VAS value decreased from 6.9±1.8 to 3.2±1.9. The mean MOCART score was 51.7±16.6 at 12 months of follow-up; these scores did not directly correlate with the clinical results. Conclusion use of the ACIC technique for arthroscopic repair of OLTs allowed satisfactory clinical results to be obtained in most of the patients as soon as one year after surgery, with no major complications or delayed revision surgery. ACIC is a valid and low-invasive surgical technique for the treatment of chondral and osteochondral defects of the talus. Level of evidence therapeutic case series, level IV.

  5. Treatment of osteochondral lesions of the talus with autologous collagen-induced chondrogenesis: clinical and magnetic resonance evaluation at one-year follow-up

    PubMed Central

    USUELLI, FEDERICO GIUSEPPE; GRASSI, MIRIAM; MANZI, LUIGI; GUARRELLA, VINCENZO; BOGA, MICHELE; DE GIROLAMO, LAURA

    2016-01-01

    Purpose the aim of this study is to report the clinical and imaging results recorded by a series of patients in whom osteochondral lesions of the talus (OLTs) were repaired using the autologous collagen-induced chondrogenesis (ACIC) technique with a completely arthroscopic approach. Methods nine patients (mean age 37.4±10 years) affected by OLTs (lesion size 2.1±0.9 cm2) were treated with the ACIC technique. The patients were evaluated clinically both preoperatively and at 12 months after surgery using the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) and a visual analog scale (VAS). For morphological evaluation, the magnetic resonance observation of cartilage repair tissue (MOCART) score was used. Results the AOFAS score improved from 51.4±11.6 preoperatively to 71.8±20.6 postoperatively, while the VAS value decreased from 6.9±1.8 to 3.2±1.9. The mean MOCART score was 51.7±16.6 at 12 months of follow-up; these scores did not directly correlate with the clinical results. Conclusion use of the ACIC technique for arthroscopic repair of OLTs allowed satisfactory clinical results to be obtained in most of the patients as soon as one year after surgery, with no major complications or delayed revision surgery. ACIC is a valid and low-invasive surgical technique for the treatment of chondral and osteochondral defects of the talus. Level of evidence therapeutic case series, level IV. PMID:27602347

  6. Prophylactic antibiotics prevent bacterial biofilm graft infection.

    PubMed

    Bergamini, T M; Peyton, J C; Cheadle, W G

    1992-02-01

    Bacterial biofilm graft infection is due to prostheses colonization by Staphylococcus epidermidis, a pathogen frequently recovered from perigraft tissues of man during vascular procedures despite the use of asepsis and prophylactic antibiotics. The effect of preoperative intraperitoneal cefazolin, administered at a standard (15 or 30 mg/kg) and high (120 mg/kg) dose, on the prevention of bacterial biofilm infection was studied in a rat model. Seventy-four Dacron grafts, colonized in vitro with S. epidermidis to produce an adherent biofilm (3.19 +/- 0.71 x 10(7) colony-forming units/cm2 graft), were implanted in the dorsal subcutaneous tissue at 0.5, 2, and 4 hr after antibiotic administration. The study strain was a slime-producing clinical isolate with minimum inhibitory concentration (MIC) of 15-30 micrograms/ml to cefazolin. Subcutaneous tissue antibiotic levels were determined at each time interval. One week after implantation, the concentration of bacteria in the surface biofilm by quantitative agar culture was significantly decreased (P less than 0.05) only for grafts implanted when antibiotic tissue levels were greater than or equal to the MIC of the study strain. The result of no growth by biofilm broth culture was significantly achieved (P less than 0.01) only for grafts implanted 0.5 hr after high dose cefazolin, in which the tissue antibiotic level was above the MIC of the study strain. Antibiotics can markedly reduce the bacteria concentration of a prosthetic surface biofilm. The effectiveness of prophylactic antibiotics on the prevention of graft infection is dependent upon maintaining an adequate antibiotic level in the perigraft tissues for the duration of the procedure.

  7. Excellent Aesthetic and Functional Outcome After Fractionated Carbon Dioxide Laser Skin Graft Revision Surgery: Case Report and Review of Laser Skin Graft Revision Techniques.

    PubMed

    Ho, Derek; Jagdeo, Jared

    2015-11-01

    Skin grafts are utilized in dermatology to reconstruct a defect secondary to surgery or trauma of the skin. Common indications for skin grafts include surgical removal of cutaneous malignancies, replacement of tissue after burns or lacerations, and hair transplantation in alopecia. Skin grafts may be cosmetically displeasing, functionally limiting, and significantly impact patient's quality-of-life. There is limited published data regarding skin graft revision to enhance aesthetics and function. Here, we present a case demonstrating excellent aesthetic and functional outcome after fractionated carbon dioxide (CO2) laser skin graft revision surgery and review of the medical literature on laser skin graft revision techniques. PMID:26580878

  8. Expression of MMP-2 and TIMP-1 in Renal Tissue of Patients with Chronic Active Antibody-mediated Renal Graft Rejection

    PubMed Central

    2012-01-01

    Objective To investigate the expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metallopropteinase-1 (TIMP-1) in the renal allografts of patients with chronic active antibody-mediated rejection (AMR), and to explore their role in the pathogenesis of AMR. Methods Immunohistochemistry assay and computer-assisted image analysis were used to detect the expression of MMP-2 and TIMP-1 in the renal allografts with interstitial fibrosis and tubular atrophy (IF/TA) in 46 transplant recipients and 15 normal renal tissue specimens as the controls. The association of the expression level of either MMP-2 or TIMP-1 with the pathological grade of IF/TA in AMR was analyzed. Results The expression of either MMP-2 or TIMP-1 was significantly increased in the renal allografts of the recipients as compared with the normal renal tissue (P < 0.05). MMP-2 expression tended to decrease, while TIMP-1 and serum creatinine increased along with the increase of pathological grade of IF/TA (P < 0.05). In IF/TA groups, the expression of TIMP-1 was positively correlated to serum creatinine level (r = 0.718, P < 0.05). Conclusions It is suggested by the results that abnormal expressions of MMP-2 and TIMP-1 might play roles in the development of renal fibrosis in chronic AMR. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1128474926172838 PMID:23057632

  9. Bioactive polymer grafting onto titanium alloy surfaces.

    PubMed

    Michiardi, A; Hélary, G; Nguyen, P-C T; Gamble, L J; Anagnostou, F; Castner, D G; Migonney, V

    2010-02-01

    Bioactive polymers bearing sulfonate (styrene sodium sulfonate, NaSS) and carboxylate (methylacrylic acid, MA) groups were grafted onto Ti6Al4V alloy surfaces by a two-step procedure. The Ti alloy surfaces were first chemically oxidized in a piranha solution and then directly subjected to radical polymerization at 70 degrees C in the absence of oxygen. The grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the toluidine blue colorimetric method. Toluidine blue results showed 1-5microgcm(-2) of polymer was grafted onto the oxidized Ti surfaces. Grafting resulted in a decrease in the XPS Ti and O signals from the underlying Ti substrate and a corresponding increase in the XPS C and S signals from the polymer layer. The ToF-SIMS intensities of the S(-) and SO(-) ions correlated linearly with the XPS atomic percent S concentrations and the ToF-SIMS intensity of the TiO(3)H(2)(-) ion correlated linearly with the XPS atomic per cent Ti concentration. Thus, the ToF-SIMS S(-), SO(-) and TiO(3)H(2)(-) intensities can be used to quantify the composition and amount of grafted polymer. ToF-SIMS also detected ions that were more characteristic of the polymer molecular structure (C(6)H(4)SO(3)(-) and C(8)H(7)SO(3)(-) from NaSS, C(4)H(5)O(2)(-) from MA), but the intensity of these peaks depended on the polymer thickness and composition. An in vitro cell culture test was carried out with human osteoblast-like cells to assess the influence of the grafted polymers on cell response. Cell adhesion after 30min of incubation showed significant differences between the grafted and ungrafted surfaces. The NaSS grafted surfaces showed the highest degree of cell adhesion while the MA-NaSS grafted surfaces showed the lowest degree of cell adhesion. After 4 weeks in vivo in rabbit femoral bones, bone was observed to be in direct contact with all implants. The percentage of mineralized tissue around the

  10. Retrograde Percutaneous Drilling for Osteochondritis Dissecans of the Head of the Talus: Case Report and Review of the Literature.

    PubMed

    Corominas, Laura; Sanpera, Ignacio; Masrouha, Karim; Sanpera-Iglesias, Julia

    2016-01-01

    Osteochondral lesions of the talus might be a more common cause of pain than previously recognized, especially among those involved in athletic activities. However, the location of an osteochondral lesion on the talar head is much less common than such lesions localized to the dome of the talus and can pose diagnostic difficulties. We present the case of a 14-year-old soccer player who complained of longstanding pain in his left foot. After unsuccessful conservative treatment consisting of rest and bracing, he was ultimately treated with retrograde percutaneous drilling of the talar head performed by a medial approach. This was followed by casting and non-weightbearing for 6 weeks, after which physical therapy was undertaken. He was able to return to full activity and remained asymptomatic during a 5-year observation period. Although rare, osteochondritis dissecans of the talar head should be considered in young athletes with persistent foot pain that is unresponsive to reasonable therapy.

  11. Retrograde Percutaneous Drilling for Osteochondritis Dissecans of the Head of the Talus: Case Report and Review of the Literature.

    PubMed

    Corominas, Laura; Sanpera, Ignacio; Masrouha, Karim; Sanpera-Iglesias, Julia

    2016-01-01

    Osteochondral lesions of the talus might be a more common cause of pain than previously recognized, especially among those involved in athletic activities. However, the location of an osteochondral lesion on the talar head is much less common than such lesions localized to the dome of the talus and can pose diagnostic difficulties. We present the case of a 14-year-old soccer player who complained of longstanding pain in his left foot. After unsuccessful conservative treatment consisting of rest and bracing, he was ultimately treated with retrograde percutaneous drilling of the talar head performed by a medial approach. This was followed by casting and non-weightbearing for 6 weeks, after which physical therapy was undertaken. He was able to return to full activity and remained asymptomatic during a 5-year observation period. Although rare, osteochondritis dissecans of the talar head should be considered in young athletes with persistent foot pain that is unresponsive to reasonable therapy. PMID:25459089

  12. Fine structure of adrenal medullary grafts in the pain modulatory regions of the rat periaqueductal gray.

    PubMed

    Sagen, J; Pappas, G D; Perlow, M J

    1987-01-01

    Recent findings in our laboratory indicate that adrenal medullary grafts produce significant alterations in pain sensitivity. Electron microscopic studies were undertaken to correlate these behavioral changes with the neural interactions of the host and graft tissue in the periaqueductal gray. A striking change found 8 weeks after transplantation is that pronounced myelination has taken place both in the graft and in the host tissue. The new myelin formation in the graft has the typical appearance of PNS myelination and, in the host the appearance of CNS myelination. The endothelial cells of the capillaries in the grafted tissue are attenuated and fenestrated in contrast to those of the surrounding parenchymal tissue of the host. By 8 weeks, the graft becomes heavily encapsulated with collagen, while the host CNS tissue develops layers of glial processes outlining the graft. However, collagen and glial layers apparently do not form an absolute barrier to either cellular or humoral interaction between the host and graft tissue. Chromaffin cells can be found protruding into the host CNS tissue and sometimes forming synapses with presumably the host neuronal processes. Grafted chromaffin cells may participate as both postsynaptic and, less often, as presynaptic components of synaptic junctions. The behavioral relevance of these synaptic contacts is unclear, since similar implants of adrenal medullary tissue into the dorsal spinal cord subarachnoid space, which also induce potent analgesia, do not contain synapses. Thus, it is more likely that behavioral changes are brought about by diffusion of neuroactive substances from grafted chromaffin cells to host receptors.

  13. Arthroscopic removal of osteochondral fragments from the proximal interphalangeal joint of the pelvic limbs in three horses.

    PubMed

    Schneider, R K; Ragle, C A; Carter, B G; Davis, W E

    1994-07-01

    Osteochondral fragments detected in the proximal interphalangeal joint in the pelvic limbs of 3 horses (2 Standardbreds and 1 Thoroughbred) caused joint enlargement and lameness. Fragments were removed by use of arthroscopy. Accurate placement of the arthroscope into the dorsal joint space was necessary to obtain an adequate view of the fragments. After surgery, 2 of the horses resumed racing without joint problems, and the third was in training to race. High-detail radiographs are necessary to detect osteochondral fragments in horses with joint enlargement or lameness localized to the proximal interphalangeal joint.

  14. Arthroscopic technique for fragment fixation using absorbable pins for osteochondritis dissecans of the humeral capitellum: a report of 4 cases.

    PubMed

    Takeba, Jun; Takahashi, Toshiaki; Hino, Kazunori; Watanabe, Seiji; Imai, Hiroshi; Yamamoto, Haruyasu

    2010-06-01

    This is the first report to describe a method of arthroscopic osteochondral fixation using absorbable pins to treat osteochondritis dissecans (OCD) of the capitellum. Four adolescent baseball players with OCD of the capitellum were treated, and good short-term results were obtained. During this arthroscopic procedure, the elbow was maintained in the maximum flexed position, and posterolateral portals were used to visualize the lesion, perform drilling, and insert the pins. This procedure is less invasive and easier to perform than other fixation procedures that require harvesting or production of autologous bone pegs. This is an effective method of fragment fixation with absorbable pins.

  15. Osteochondral lesion of the talus in a recreational athlete: a case report

    PubMed Central

    deGraauw, Chris

    1999-01-01

    A 23-year-old recreational male athlete presented with intermittent pain of three weeks duration, localized to the left ankle. Pain was aggravated by walking, although his symptoms had not affected the patient’s jogging activity which was performed three times per week. Past history revealed an inversion sprain of the left ankle, sustained fifteen months previously. Examination showed mild swelling anterior to the ankle mortise joint while other tests including range of motion, strength and motion palpation of specific joints of the ankle were noted to be unremarkable. Radiographic findings revealed a defect in the medial aspect of the talus. An orthopaedic referral was made for further evaluation. Tomography revealed a Grade III osteochondral lesion of the talus. It was determined that follow-up views be taken in three months to demonstrate if the lesion was progressing or healing. Within the three month period, activity modifications and modalities for pain control were indicated. Surgery was considered a reasonable option should conservative measures fail. The present case illustrates an osteochondral lesion of the talus, a condition which has not previously been reported in the chiropractic literature. A review of the pertinent orthopaedic literature has indicated an average delay of three years in diagnosing the existence of this lesion. Although considered rare, the diagnostic frequency of the condition appears to be on the rise due to increased awareness and the use of bone and CT scans. The osteochondral lesion of the talus deserves particular consideration by practitioners working with athletes due to its higher incidence within this group. This diagnosis should be considered in patients presenting with chronic ankle pain particularly when a history of an inversion sprain exists. The purpose of this report is to increase awareness of this condition, and review diagnosis and management strategies. ImagesFigure 1Figure 2

  16. Osteochondral lesions of the talus: clinical and functional assessment of conservative vs scope treatment

    PubMed Central

    Ibáñez, Maximiliano; Calvo, Ana Belén; Alvarez, Victoria; Lépore, Salvador

    2015-01-01

    Introduction: Osteochondral injuries involving the ankle joint are unusual (incidence of 0.09% according to Berndt and Harty), third in frequency after knee and elbow location. They are described as a cause of chronic pain after ankle sprains in the active population (thought to occur in 2-6% of sprains). MRI is the gold standard diagnostic method. Therapeutic strategies include both conservative and surgical treatment. The aim of our study was to evaluate the clinical and functional outcome of patients with osteochondral lesions of the talus. Materials and Methods: We retrospectively reviewed 20 patients with osteochondral lesions of the talus treated in our department between January 2007 and December 2012. Sixty per cent were male with an average age of 42 years. Eleven patients were treated conservatively, one of them had clear surgical indication (LOC G III, as classified by Ferkel and Sgaglione) but refused to perform the procedure. Nine patients underwent arthroscopic surgery (debridement and microfracture), one of the procedures was a review of an arthroscopy performed in another service. No open surgery was performed. Clinical and functional evaluation was performed using the AOFAS score, Freiburg and VAS Score System. Results: Non-surgical treatment group had a pretreatment average AOFAS score of 58, which improved to 74.8 points; a Freiburg Score System that ranged from 65 to 79.3 points and a VAS average of 5,4. AOFAS surgical treatment group improved from 54.3 to 84.8 points, Freiburg Score System ranged from 60.6 to 81.4 points and VAS average was of 5,8. Discussion: It is difficult to compare our results with other series of patients, because we made a comparison between conservative versus artrhoscopic treatment, while other authors show results obtained when performing certain surgical technique Although surgical treatment has better results, we agree with the literature that conservative treatment presents acceptable results and should always be

  17. Graft of a Tissue-Engineered Neural Scaffold Serves as a Promising Strategy to Restore Myelination after Rat Spinal Cord Transection

    PubMed Central

    Lai, Bi-Qin; Wang, Jun-Mei; Ling, Eng-Ang; Wu, Jin-Lang

    2014-01-01

    Remyelination remains a challenging issue in spinal cord injury (SCI). In the present study, we cocultured Schwann cells (SCs) and neural stem cells (NSCs) with overexpression of neurotrophin-3 (NT-3) and its high affinity receptor tyrosine kinase receptor type 3 (TrkC), respectively, in a gelatin sponge (GS) scaffold. This was aimed to generate a tissue-engineered neural scaffold and to investigate whether it could enhance myelination after a complete T10 spinal cord transection in adult rats. Indeed, many NT-3 overexpressing SCs (NT-3-SCs) in the GS scaffold assumed the formation of myelin. More strikingly, a higher incidence of NSCs overexpressing TrkC differentiating toward myelinating cells was induced by NT-3-SCs. By transmission electron microscopy, the myelin sheath showed distinct multilayered lamellae formed by the seeded cells. Eighth week after the scaffold was transplanted, some myelin basic protein (MBP)-positive processes were observed within the transplantation area. Remarkably, certain segments of myelin derived from NSC-derived myelinating cells and NT-3-SCs were found to ensheath axons. In conclusion, we show here that transplantation of the GS scaffold promotes exogenous NSC-derived myelinating cells and SCs to form myelins in the injury/transplantation area of spinal cord. These findings thus provide a neurohistological basis for the future application or transplantation using GS neural scaffold to repair SCI. PMID:24325427

  18. COMPARATIVE MACROSCOPIC STUDY OF OSTEOCHONDRAL DEFECTS PRODUCED IN FEMURS OF RABBITS REPAIRED WITH BIOPOLYMER GEL CANE SUGAR

    PubMed Central

    de Albuquerque, Paulo Cezar Vidal Carneiro; dos Santos, Saulo Monteiro; de Andrade Aguiar, José Lamartine; Filho, Nicodemus Pontes; de Mello, Roberto José Vieira; Costa, Mariana Lúcia Correia Ramos; de Albuquerque Olbertz, Clarissa Miranda Carneiro; de Souza Almeida, Tarciana Mendonça; da Silva Santos, Alessandro Henrique; da Silva, Joacil Carlos

    2015-01-01

    Objective: To study the surface, coloring, consistency, continuity and healing of osteochondral defects produced in the femoral condyles of rabbits and filled with sugar cane biopolymer gel (SCBG), after 90, 120 and 180 days, and in comparison with a control group. Method: Sixteen adult New Zealand white rabbits aged 6 to 7 months, weighing between 2 and 2.5 kg and without locomotor system abnormalities were studied. In all the animals, a defect was made in the femoral condyles of the right and left knees, measuring 3.2 mm in diameter and 4 mm in depth, using a trephine. The animals were divided into two groups: study group formed by the right knees, in which the medial and lateral condyles received implants of SCBG; and control group formed by the left knees, in which the medial and lateral condyles were allowed to heal naturally. The knees were assessed 90, 120 and 180 days after the operation. After the animals had been sacrificed, the anatomical specimens were resected and placed in Bouin's solution. They were then photographed with a Nikon Coolpix 5400® coupled to a Nikon SM2800® stereoscopic loupe, to analyze the surface, coloring, consistency, continuity and healing. Results: The results were evaluated using the chi-square test. There were no significant differences in the macroscopic assessments of healing between the study and control groups. Conclusion: With regard to the surface, coloring, consistency, continuity and healing of the defects, the macroscopic appearance of the tissue repaired with SCBG was similar to that of the control group. PMID:27027057

  19. Experience of vein grafting in Göttingen minipigs.

    PubMed

    Tsutsumi, H; Miyawaki, F; Arakawa, H; Tsuji, T; Tanigawa, M

    2001-04-01

    We experimented with vein grafting surgery on Göttingen minipigs. Using the internal jugular vein for the tissue graft, we performed side-to-side anastomosis to the carotid artery, to which it runs parallel. One key point in this surgery was to prevent vasospasm of the carotid artery so as to keep the lumen sufficiently patent during anastomosis. The histopathological findings in the grafts which remained patent resembled those of vein grafts in humans. We therefore considered that this technique in minipigs can be applied for the study of coronary artery bypass surgery in humans.

  20. The use of bone graft substitutes in large cancellous voids: any specific needs?

    PubMed

    Faour, Omar; Dimitriou, Rozalia; Cousins, Charlotte A; Giannoudis, Peter V

    2011-09-01

    Bone graft is the second most common transplantation tissue, with blood being by far the commonest. Autograft is considered ideal for grafting procedures, providing osteoinductive growth factors, osteogenic cells and an osteoconductive scaffold. Limitations, however, exist regarding donor site morbidity and graft availability. Allograft on the other hand poses the risk of disease transmission. Synthetic graft substitutes lack osteoinductive or osteogenic properties. Composite grafts combine scaffolding properties with biological elements to stimulate cell proliferation and differentiation and eventually osteogenesis. We present here an overview of bone graft substitutes available for clinical application in large cancellous voids.

  1. Use of polycaprolactone grafts for small-diameter blood vessels.

    PubMed

    Sevost'ianova, V V; Elgudin, Ia A; Glushkova, T V; Wnek, G; Liubysheva, T; Emancipator, S; Kudriavtseva, Iu A; Borisov, V V; Golovkin, A S; Barbarash, L S

    2015-01-01

    Current trends are toward actively developing approaches of tissue engineering, aimed at creating vascular grafts of small diameter. This is due to the existing in cardiovascular surgery demand for prostheses to be used in coronary artery bypass grafting. The present work was undertaken in order to assess possibilities of using smalldiameter vascular grafts made of biodegradable polymer polycaprolactone by means of electrospinning. The authors studied physico-mechanical properties and structure of polycaprolactone grafts, as well as their thromboresistance and patency after implantation into the vascular bed of rats. The obtained results demonstrated optimal physicomechanical properties of the vascular grafts, their biocompatibility, endothelialisation of the internal surface, and infiltration of the graft's wall by cells with the formation of new tissue, accompanied and followed by the development of an extensive intimal layer in the zones of the anastomoses. Hence, the study showed possibilities of using polycaprolactone grafts as vascular prostheses, however requiring their further modification which would promote and contribute to a decrease in hyperplasia of connective tissue in the graft's lumen.

  2. Positive effect of oral supplementation with glycosaminoglycans and antioxidants on the regeneration of osteochondral defects in the knee joint.

    PubMed

    Handl, M; Amler, E; Bräun, K; Holzheu, J; Trc, T; Imhoff, A B; Lytvynets, A; Filová, E; Kolárová, H; Kotyk, A; Martínek, V

    2007-01-01

    The effect of oral supplementation with glycosaminoglycans (GAG) and radical scavengers (vitamin E/selenium) on the regeneration of osteochondral defects was investigated in rabbits. After introduction of defined osteochondral defects in the knee joint, groups of ten animals were given a GAG/vitamin E/selenium mixture or a placebo (milk sugar) for 6 weeks. Following sacrifice, histological and histochemical analysis was performed. The amount of synovial fluid was increased in the placebo group, while the viscosity of the synovial fluid was significantly enhanced in the GAG group. The amount of sulfated GAG in the osteochondral regenerates (8.8 +/- 3.6 % vs. 6.0 +/- 5.6 %; p <0.03) was significantly higher in the GAG group. In both groups, the GAG amount in the cartilage of the operated knee was significantly higher than in the non-involved knee (p <0.05). Histological analysis of the regenerates in the GAG group was superior in comparison with the placebo group. For the first time, a biological effect following oral supplementation with GAG was demonstrated in healing of osteochondral defects in vivo. These findings support the known positive clinical results.

  3. Effects of pre- and postoperative irradiation on the healing of bone grafts in the rabbit

    SciTech Connect

    Morales, M.J.; Marx, R.E.; Gottlieb, C.F.

    1987-01-01

    Healing of cellular bone grafts irradiated at various times in the postsurgical course was compared to the healing characteristics of bone grafts placed into already irradiated tissue and to controls of irradiated host mandible in a rabbit model. Physical graft consolidation was assessed by load stress characteristics and serial histologic examination. Results indicated that grafts placed into already irradiated tissues failed to form bone in both phases of expected regeneration resulting in structurally weakened and histologically deficient ossicles. Bone grafts irradiated after placement were tolerant of irradiation. Bone grafts irradiated after four weeks were found to be less affected by irradiation than those irradiated within the first four weeks, forming an ossicle structurally and histologically superior to that of bone ossicles developed from grafts placed into irradiated tissues.

  4. Evidence of a major gene from Bayesian segregation analyses of liability to osteochondral diseases in pigs.

    PubMed

    Kadarmideen, Haja N; Janss, Luc L G

    2005-11-01

    Bayesian segregation analyses were used to investigate the mode of inheritance of osteochondral lesions (osteochondrosis, OC) in pigs. Data consisted of 1163 animals with OC and their pedigrees included 2891 animals. Mixed-inheritance threshold models (MITM) and several variants of MITM, in conjunction with Markov chain Monte Carlo methods, were developed for the analysis of these (categorical) data. Results showed major genes with significant and substantially higher variances (range 1.384-37.81), compared to the polygenic variance (sigmau2). Consequently, heritabilities for a mixed inheritance (range 0.65-0.90) were much higher than the heritabilities from the polygenes. Disease allele frequencies range was 0.38-0.88. Additional analyses estimating the transmission probabilities of the major gene showed clear evidence for Mendelian segregation of a major gene affecting osteochondrosis. The variants, MITM with informative prior on sigmau2, showed significant improvement in marginal distributions and accuracy of parameters. MITM with a "reduced polygenic model" for parameterization of polygenic effects avoided convergence problems and poor mixing encountered in an "individual polygenic model." In all cases, "shrinkage estimators" for fixed effects avoided unidentifiability for these parameters. The mixed-inheritance linear model (MILM) was also applied to all OC lesions and compared with the MITM. This is the first study to report evidence of major genes for osteochondral lesions in pigs; these results may also form a basis for underpinning the genetic inheritance of this disease in other animals as well as in humans. PMID:16020792

  5. The adipokine lipocalin-2 in the context of the osteoarthritic osteochondral junction

    PubMed Central

    Villalvilla, Amanda; García-Martín, Adela; Largo, Raquel; Gualillo, Oreste; Herrero-Beaumont, Gabriel; Gómez, Rodolfo

    2016-01-01

    Obesity and osteoarthritis (OA) form a vicious circle in which obesity contributes to cartilage destruction in OA, and OA-associated sedentary behaviour promotes weight gain. Lipocalin-2 (LCN2), a novel adipokine with catabolic activities in OA joints, contributes to the obesity and OA pathologies and is associated with other OA risk factors. LCN2 is highly induced in osteoblasts in the absence of mechanical loading, but its role in osteoblast metabolism is unclear. Therefore, because osteochondral junctions play a major role in OA development, we investigated the expression and role of LCN2 in osteoblasts and chondrocytes in the OA osteochondral junction environment. Our results showed that LCN2 expression in human osteoblasts and chondrocytes decreased throughout osteoblast differentiation and was induced by catabolic and inflammatory factors; however, TGF-β1 and IGF-1 reversed this induction. LCN2 reduced osteoblast viability in the presence of iron and enhanced the activity of MMP-9 released by osteoblasts. Moreover, pre-stimulated human osteoblasts induced LCN2 expression in human chondrocytes, but the inverse was not observed. Thus, LCN2 is an important catabolic adipokine in osteoblast and chondrocyte metabolism that is regulated by differentiation, inflammation and catabolic and anabolic stimuli, and LCN2 expression in chondrocytes is regulated in a paracrine manner after osteoblast stimulation. PMID:27385438

  6. Continuous gradients of material composition and growth factors for effective regeneration of the osteochondral interface.

    PubMed

    Mohan, Neethu; Dormer, Nathan H; Caldwell, Kenneth L; Key, Vincent H; Berkland, Cory J; Detamore, Michael S

    2011-11-01

    Most contemporary biomaterial designs for osteochondral regeneration utilize monolithic, biphasic, or even multiphasic constructs. We have introduced a microsphere-based approach to create a continuous gradient in both material composition and encapsulated growth factors. The gradients were fabricated by filling a cylindrical mold with opposing gradients of two different types of poly(D,L-lactic-co-glycolic acid) microspheres. The chondrogenic microspheres were loaded with transforming growth factor-β1, whereas the osteogenic microspheres contained bone morphogenetic protein-2 with or without nanophase hydroxyapatite. The gradient scaffolds (material gradient only, signal gradient only, or material/signal gradient combination) or blank control scaffolds were implanted in 3.5 mm-diameter defects in rabbit knees for 6 or 12 weeks. This is the first in vivo evaluation of these novel gradient scaffolds in the knee. The gross morphology, MRI, and histology indicated that the greatest extent of regeneration was achieved when both signal and material gradients were included together. This combination resulted in complete bone ingrowth, with an overlying cartilage layer with high glycosaminoglycan content, appropriate thickness, and integration with the surrounding cartilage and underlying bone. The results suggest that osteochondral regeneration may benefit from biomaterials that integrate a continuous gradient in both material composition and encapsulated growth factors.

  7. Improvement of tomato local varieties by grafting in organic farming

    NASA Astrophysics Data System (ADS)

    Moreno, Marta M.; Villena, Jaime; Moreno, Carmen; García, Arántzazu M.; Mancebo, Ignacio; Meco, Ramón

    2015-04-01

    Grafting is the union of two or more pieces of living plant tissue that grow as a single plant. The early use of grafted vegetables was associated with protected cultivation which involves successive cropping (Lee et al., 2010). For this reason, in the past, grafting was used with vegetable crops to limit the effects of soil-borne diseases. However, the reasons for grafting as well as the kinds of vegetable grafted have increased considerably over the years. In tomato (Solanum lycopersicum L.), one of the most important horticultural crops in the world, the effect of grafting has also been widely studied. These effects on commercial tomato varieties can be summarized in increasing plant vigor and crop yield or inducing tolerance to abiotic stresses, although the effects on tomato fruit quality or on the sensory properties are not so patent (David et al., 2008). However, a few studies about the effect of grafting on local tomato varieties, which are especially recommended for organic production in spite of their lower yields in many cases, have been developed. In this work we evaluated the effect of grafting on tomato local varieties under organic management using vigorous commercial rootstocks, and aspects related to vigor, yield and tomato fruit composition were analyzed. In general terms, grafting increased the plant vigor, the crop yield and the fruit antioxidant content, although no modification of morphological fruit attributes was observed. Keywords: grafting, Solanum lycopersicum L., local varieties, organic farming. References: Davis A.R., Perkins-Veazie P., Hassell R., Levi A., King S.R., Zhang X. 2008. Grafting effects on vegetable quality. HortScience 43(6): 1670-1671. Lee J.M., Kubota C., Tsao S.J., Bie Z., Hoyos-Echevarría P., Morra L., Oda M. 2010. Current status of vegetable grafting: Diffusion, grafting techniques, automation. Scientia Horticulturae 127: 93-105.

  8. Calcar bone graft

    SciTech Connect

    Bargar, W.L.; Paul, H.A.; Merritt, K.; Sharkey, N.

    1986-01-01

    A canine model was developed to investigate the use of an autogeneic iliac bone graft to treat the calcar deficiency commonly found at the time of revision surgery for femoral component loosening. Five large male mixed-breed dogs had bilateral total hip arthroplasty staged at three-month intervals, and were sacrificed at six months. Prior to cementing the femoral component, an experimental calcar defect was made, and a bicortical iliac bone graft was fashioned to fill the defect. Serial roentgenograms showed the grafts had united with no resorption. Technetium-99 bone scans showed more uptake at three months than at six months in the graft region. Disulfine blue injection indicated all grafts were perfused at both three and six months. Thin section histology, fluorochromes, and microradiographs confirmed graft viability in all dogs. Semiquantitative grading of the fluorochromes indicated new bone deposition in 20%-50% of each graft at three months and 50%-80% at six months. Although the calcar bone graft was uniformly successful in this canine study, the clinical application of this technique should be evaluated by long-term results in humans.

  9. Evaluation of the Early In Vivo Response of a Functionally Graded Macroporous Scaffold in an Osteochondral Defect in a Rabbit Model.

    PubMed

    Barron, Valerie; Neary, Martin; Mohamed, Khalid Merghani Salid; Ansboro, Sharon; Shaw, Georgina; O'Malley, Grace; Rooney, Niall; Barry, Frank; Murphy, Mary

    2016-05-01

    Cartilage tissue engineering is a multifactorial problem requiring a wide range of material property requirements from provision of biological cues to facilitation of mechanical support in load-bearing diarthrodial joints. The study aim was to design, fabricate and characterize a template to promote endogenous cell recruitment for enhanced cartilage repair. A polylactic acid poly-ε-caprolactone (PLCL) support structure was fabricated using laser micromachining technology and thermal crimping to create a functionally-graded open pore network scaffold with a compressive modulus of 9.98 ± 1.41 MPa and a compressive stress at 50% strain of 8.59 ± 1.35 MPa. In parallel, rabbit mesenchymal stem cells were isolated and their growth characteristics, morphology and multipotency confirmed. Sterilization had no effect on construct chemical structure and cellular compatibility was confirmed. After four weeks implantation in an osteochondral defect in a rabbit model to assess biocompatibility, there was no evidence of inflammation or giant cells. Moreover, acellular constructs performed better than cell-seeded constructs with endogenous progenitor cells homing through microtunnels, differentiating to form neo-cartilage and strengthening integration with native tissue. These results suggest, albeit at an early stage of repair, that by modulating the architecture of a macroporous scaffold, pre-seeding with MSCs is not necessary for hyaline cartilage repair.

  10. Evaluation of the Early In Vivo Response of a Functionally Graded Macroporous Scaffold in an Osteochondral Defect in a Rabbit Model.

    PubMed

    Barron, Valerie; Neary, Martin; Mohamed, Khalid Merghani Salid; Ansboro, Sharon; Shaw, Georgina; O'Malley, Grace; Rooney, Niall; Barry, Frank; Murphy, Mary

    2016-05-01

    Cartilage tissue engineering is a multifactorial problem requiring a wide range of material property requirements from provision of biological cues to facilitation of mechanical support in load-bearing diarthrodial joints. The study aim was to design, fabricate and characterize a template to promote endogenous cell recruitment for enhanced cartilage repair. A polylactic acid poly-ε-caprolactone (PLCL) support structure was fabricated using laser micromachining technology and thermal crimping to create a functionally-graded open pore network scaffold with a compressive modulus of 9.98 ± 1.41 MPa and a compressive stress at 50% strain of 8.59 ± 1.35 MPa. In parallel, rabbit mesenchymal stem cells were isolated and their growth characteristics, morphology and multipotency confirmed. Sterilization had no effect on construct chemical structure and cellular compatibility was confirmed. After four weeks implantation in an osteochondral defect in a rabbit model to assess biocompatibility, there was no evidence of inflammation or giant cells. Moreover, acellular constructs performed better than cell-seeded constructs with endogenous progenitor cells homing through microtunnels, differentiating to form neo-cartilage and strengthening integration with native tissue. These results suggest, albeit at an early stage of repair, that by modulating the architecture of a macroporous scaffold, pre-seeding with MSCs is not necessary for hyaline cartilage repair. PMID:26438451

  11. Grafts in "closed" rhinoplasty.

    PubMed

    Scattolin, A; D'Ascanio, L

    2013-06-01

    Rhinoplasty is a fascinating and complex surgical procedure aiming at attaining a well-functioning and aesthetically pleasant nose. The use of grafts is of the utmost importance for the nasal surgeon to achieve such results. However, the philosophy and technical use of nasal grafts are different in "closed" and "open" rhinoplasty. The aim of this paper is not detailed description of the numerous grafts reported in the literature; we will describe the main principles of grafts use in "closed" rhinoplasty derived from our experience, with special reference to the philosophical and technical differences in their employment between "closed" and "open" rhinoplasty. Some cases are reported as an example of graft use in "endonasal" approach rhinoplasty.

  12. Systematic Review and Meta-analysis of Osteochondral Autograft Transplantation versus Debridement in the Treatment of Osteochondritis Dessicans of the Capitellum

    PubMed Central

    Bowman, Seth; Braunstein, Jacob; Rabinowitz, Justin; Barfield, William R.; Chhabra, Bobby; Haro, Marc Scott

    2016-01-01

    Objectives: The purpose of this systematic review and meta- analysis is to compare clinical results and functional outcomes in patients with osteochondritis dessicans (OCD) lesions of the capitellum treated with either osteochondral autograft transplantation (OATS) or debridement with or without microfracture. Methods: Systematic review of multiple medical databases was performed after PROSPERO registration and using PRISMA guidelines. A literature search was performed using the multiple medical databases and the methodological quality of the individual studies was assessed by two review authors using the Cochrane Collaboration’s “Risk of Bias” tool. Case reports were excluded and only case series of more than five patients and higher level of evidence were included. All study, subject, and surgery parameters were collected. Data was analyzed using statistical software. Odds ratios (OR) were calculated when possible. Data were compared using Pearson Chi-Square and independent sample T tests when applicable. Results: Fifteen studies were included involving 368 patients (326 males and 42 females). There were a total of 197 patients in the debridement group and 171 patients in the OATS group. The mean age was 16.9 +/-4.1 for the debridement group and 14.6 +/-1.2 for the OATS group. Mean follow up was 29.0 +/-24.3 and 38.0 +/-12.8 for the debridement and OATS groups, respectively. Patients that underwent an OATS procedure had a statistically significant improvement in overall arc range of motion compared to patients that had a debridement (P≤0.001). When compared to patients with debridement, patients with OATS were 5.6 times more likely to return to at least their pre-injury level of sports participation (p≤0.002). Conclusion: Post-operative range of motion was significantly improved in patients undergoing an OATS procedure versus a debridement for OCD lesions of the capitellum. Patients with an OATS were 5.7 times more likely to return to at least the pre

  13. The experimental validation of free fat grafts in thoracic surgery.

    PubMed

    Murakami, Junichi; Ueda, Kazuhiro; Hayashi, Masataro; Kondo, Tomoko; Hamano, Kimikazu

    2016-10-01

    We evaluated the viability of free fat grafts in the thoracic cavity using 3-month old male swine (n = 2). After left caudal lobectomy, 1-3 g of subcutaneous fat tissue harvested via the thoracotomy site was implanted in the chest cavity. At re-thoracotomy 6 weeks after implantation, all of the implanted fat grafts (n = 15) were found to have closely adhered to the parietal pleura and visceral pleura. There was a significant decrease by ∼30% in the weight of the fat grafts after implantation. Regardless of the weight loss, the implanted fat graft showed normal structuring without scar formation in the central area. Our results may suggest that free fat pads, which weighed up to 3 g, were successfully cultured in the thoracic cavity until the implanted tissues integrated into the surrounding tissues. Therefore, the free fat pad can be used as a biomaterial for some purposes in thoracic surgery.

  14. Staged tendon grafts and soft tissue coverage

    PubMed Central

    Elliot, David

    2011-01-01

    The objective of the two-staged flexor tendon method is to improve the predictability of final results in difficult problems dealing with tendon reconstruction. This article reviews the evolution and benefits of this procedure. It also considers the use of the technique to help deal with problems requiring pulley and skin reconstruction simultaneously with re-constituting the flexor tendon system. PMID:22022043

  15. [Fundamentals and principles of grafts and flaps].

    PubMed

    Cruz-Navarro, Natalio; León-Dueñas, Eduardo

    2014-01-01

    Reconstructive surgery of large urethral stenosis and the management of congenital anomalies such as hypospadias and epispadias require covering large cutaneous and mucosal defects with different techniques. The objective of this work is to define the main differences between tissues to be transferred and to study the principles that must govern the management of the various flaps and grafts used for these techniques. We analyze the anatomical and physiological features that may be key to understand the success and possible failures of these procedures, and we review technical details that must accompany in every case, not only during the operation, but also during the preoperative and postoperative period. We conclude stating that grafts (mainly oral and preputial mucosa) and flaps are increasingly used for the repair of urethral stenosis. Grafts must be prepared adequately in the back table and thinned to the maximum, and also be fixed properly, to guarantee their immobility until neovascularization is assured.

  16. Infrainguinal anastomotic arterial graft infections treated by selective graft preservation.

    PubMed Central

    Calligaro, K D; Westcott, C J; Buckley, R M; Savarese, R P; DeLaurentis, D A

    1992-01-01

    The purpose of this study was to determine whether the type of graft material and bacteria involved in an infrainguinal arterial anastomotic infection can be used as guidelines for graft preservation. Between 1972 and 1990, the authors treated 35 anastomotic infections involving a common femoral or distal artery. The graft material was Dacron in 14 patients, polytetrafluoroethylene (PTFE) in 14, and vein in 7. Of the 14 Dacron grafts, immediate graft excision was required for overwhelming infection in eight patients (bleeding in five, sepsis in three) and for an occluded graft in one patient. Three of five patients failed attempted graft preservation because of nonhealing wounds. Thus, 12 of the 14 Dacron grafts ultimately required graft excision. Of the 21 "smooth-walled" vein and PTFE grafts, 10 required immediate graft excision for occluded grafts (five PTFE, one vein) or bleeding (three PTFE, one vein). Ten of the remaining 11 (91%) patients with patent "smooth-walled" grafts, intact anastomoses, and absence of sepsis managed by graft preservation healed their wounds and maintained distal arterial perfusion. Wound cultures grew pure gram-positive cocci in 17 of 21 "smooth-walled" graft infections versus 8 of 14 Dacron graft infections. In the absence of systemic sepsis, graft preservation is the treatment of choice for gram-positive infections involving an intact anastomosis of patent PTFE and vein grafts. Regardless of the bacterial cause, the authors recommend that any infrainguinal anastomotic infection of a Dacron graft be treated by immediate excision of all infected graft material. PMID:1632705

  17. Allograft Replacement for Absent Native Tissue

    PubMed Central

    Chaudhury, Salma; Wanivenhaus, Florian; Fox, Alice J.; Warren, Russell F.; Doyle, Maureen; Rodeo, Scott A.

    2013-01-01

    Context: Structural instability due to poor soft tissue quality often requires augmentation. Allografts are important biological substitutes that are used for the symptomatic patient in the reconstruction of deficient ligaments, tendons, menisci, and osteochondral defects. Interest in the clinical application of allografts has arisen from the demand to obtain stable anatomy with restoration of function and protection against additional injury, particularly for high-demand patients who participate in sports. Traditionally, allografts were employed to reinforce weakened tissue. However, they can also be employed to substitute deficient or functionally absent tissue, particularly in the sports medicine setting. Objective: This article presents a series of 6 cases that utilized allografts to restore functionally deficient anatomic architecture, rather than just simply augmenting the degenerated or damaged native tissue. Detailed discussions are presented of the use of allografts as a successful treatment strategy to replace functionally weakened tissue, often after failed primary repairs. PMID:24427387

  18. Crosslinked grafted PVC obtained by direct radiation grafting

    NASA Astrophysics Data System (ADS)

    Hegazy, El-Sayed A.; Dessouki, Ahmed M.; El-Dessouky, Maher M.; El-Sawy, Naeem M.

    Direct radition-induced grafting of 4-vinylpyridine onto both pure and plasticized poly(vinyl chloride) has been studied. The effect of grafting conditions such as solvent, monomer concentration, irradiation dose, and inhibitor concentration on the grafting yield was investigated. The grafting process was enhanced by using distilled water as diluent and higher degrees of grafting were obtained as compared with other solvents used (benzene, methanol, and a mixture of methanol and water). The homopolymerization of 4-vinylpyridine was reduced to a minimum using ammonium ferrous sulfate and the suitable optimum concentration of the inhibitor was found to be 0.25 wt %. It was observed that the degrees of grafting onto plasticized PVC were higher than those onto pure one, at constant grafting conditions. The diffusibility of the monomer solution through the trunk polymers enhanced at higher monomer concentrations. The higher the monomer concentration the higher the degrees of grafting obtained. The dependence of the grafting rate on monomer concentration was found to be 0.15 and 0.4 order for the grafting onto pure and plasticized PVC films, respectively. The degree of grafting, at the higher irradiation doses, deviated from linearity and it tends to level off due to the recombination of some of the free radicals without initiating graft polymerization. Gel determination in the grafted films was investigated. The gel content in both grafted extracted pure and plasticized PVC films increased with the degree of grafting to reach a certain limiting values.

  19. Imaging characteristics of bone graft materials.

    PubMed

    Beaman, Francesca D; Bancroft, Laura W; Peterson, Jeffrey J; Kransdorf, Mark J; Menke, David M; DeOrio, James K

    2006-01-01

    Bone graft materials are widely used in reconstructive orthopedic procedures to promote new bone formation and bone healing, provide a substrate and scaffolding for development of bone structure, and function as a means for direct antibiotic delivery. Bone graft materials include autografts, allografts, and synthetic substitutes. An autograft (from the patient's own bone) supplies both bone volume and osteogenic cells capable of new bone formation. The imaging appearance of an autograft depends on its type, composition, and age. Autografts often appear as osseous fragments at radiography. At computed tomography (CT), autografts appear similar to the adjacent cortical bone. At magnetic resonance (MR) imaging, however, autografts have a variable appearance as a consequence of the viable marrow inside them, a feature not present in other graft materials. An allograft (from cadaveric bone) has an appearance similar to that of cortical bone on radiographs and CT images. An allograft in the form of bone chips or morsels does not show those features on radiographs and CT images, but instead appears as a conglomerate with medium to high opacity and attenuation within the bone defect. In the immediate postoperative period, allografts appear hypointense on both T1- and T2-weighted MR images. Hematopoietic tissue replaces the normal fatty marrow in the later phases of graft incorporation. Synthetic bone substitutes are much more variable in imaging appearance. As the use of bone allografts and synthetic substitutes increases, familiarity with postoperative imaging features is essential for differentiation between grafts and residual or recurrent disease.

  20. Feasibility of ultrasound imaging of osteochondral defects in the ankle: a clinical pilot study.

    PubMed

    Kok, A C; Terra, M P; Muller, S; Askeland, C; van Dijk, C N; Kerkhoffs, G M M J; Tuijthof, G J M

    2014-10-01

    Talar osteochondral defects (OCDs) are imaged using magnetic resonance imaging (MRI) or computed tomography (CT). For extensive follow-up, ultrasound might be a fast, non-invasive alternative that images both bone and cartilage. In this study the potential of ultrasound, as compared with CT, in the imaging and grading of OCDs is explored. On the basis of prior CT scans, nine ankles of patients without OCDs and nine ankles of patients with anterocentral OCDs were selected and classified using the Loomer CT classification. A blinded expert skeletal radiologist imaged all ankles with ultrasound and recorded the presence of OCDs. Similarly to CT, ultrasound revealed typical morphologic OCD features, for example, cortex irregularities and loose fragments. Cartilage disruptions, Loomer grades IV (displaced fragment) and V (cyst with fibrous roof), were visible as well. This study encourages further research on the use of ultrasound as a follow-up imaging modality for OCDs located anteriorly or centrally on the talar dome.

  1. Proximal Tibial Bone Graft

    MedlinePlus

    ... Complications Potential problems after a PTBG include infection, fracture of the proximal tibia and pain related to the procedure. Frequently Asked Questions If proximal tibial bone graft is taken from my knee, will this prevent me from being able to ...

  2. Clinical outcome of internal fixation of unstable juvenile osteochondritis dissecans lesions of the knee.

    PubMed

    Webb, Jonathan E; Lewallen, Laura W; Christophersen, Christy; Krych, Aaron J; McIntosh, Amy L

    2013-11-01

    Juvenile osteochondritis dissecans (OCD) lesions of the knee are a common cause of knee pain in skeletally immature patients.The authors sought to determine lesion healing rates, the risk factors associated with failure to heal, and the clinical outcomes for patients who underwent internal fixation for unstable OCD lesions. A retrospective review was conducted of all patients who underwent internal fixation of OCD lesions from 1999 to 2009. Using validated scoring systems, clinical outcome and functional activity were evaluated at the follow-up. The study group comprised 19 patients (20 knees). Mean patient age was 14.5 years (range, 12-17 years). Mean clinical follow-up was 7 years (range, 2-13 years). Mean radiographic follow-up was 2.5 years (range, 0.5-9 years). Fourteen (70%) lesions were grade 3 and 6 (30%) were grade 4. Eleven knees had lateral condyle lesions and 9 had medial lesions. Bioabsorbable fixation was used in 13 knees, metal fixation was used in 5 knees, and 2 knees were fixed with a combination of methods. Osseous integration was evident in 15 (75%) of 20 knees at final follow-up. The 5 unhealed lesions were lateral condylar lesions. Mean Tegner activity scores improved from 3.3 preoperatively to 5.6 at final follow-up. Mean Lysholm and International Knee Documentation Committee scores were 86.8 and 88.7, respectively, at final follow-up. Further operative intervention was required in 11 knees, with 50% of patients undergoing removal of hardware and 15% requiring subsequent osteochondral allograft transplantation. The authors recommend bioabsorbable fixation for symptomatic stable lesions and metal compression screws with staged removal for unstable lesions.

  3. Return to Sport After Operative Management of Osteochondritis Dissecans of the Capitellum

    PubMed Central

    Westermann, Robert W.; Hancock, Kyle J.; Buckwalter, Joseph A.; Kopp, Benjamin; Glass, Natalie; Wolf, Brian R.

    2016-01-01

    Background: Capitellar osteochondritis dissecans (OCD) is commonly managed surgically in symptomatic adolesent throwers and gymnasts. Little is known about the impact that surgical technique has on return to sport. Purpose: To evaluate the clinical outcomes and return-to-sport rates after operative management of OCD lesions in adolescent athletes. Study Design: Systematic review; Level of evidence, 4. Methods: The PubMed, CINAHL, EMBASE, SPORTDiscus (EBSCO), and Cochrane Central Register of Controlled Trials databases were queried for studies evaluating outcomes and return to sport after surgical management of OCD of the capitellum. Two independent reviewers conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies reporting patient outcomes with return-to-sport data and minimum 6-month follow-up were included in the review. Results: After review, 24 studies reporting outcomes in 492 patients (mean age ± SD, 14.3 ± 0.9 years) were analyzed. The overall return-to-sport rate was 86% at a mean 5.6 months. Return to the highest preoperative level of sport was most common after osteochondral autograft procedures (94%) compared with debridement and marrow stimulation procedures (71%) or OCD fixation surgery (64%). Elbow range of motion improved by 15.9° after surgery. The Timmerman-Andrews subjective and objective scores significantly improved after surgery. Complications were low (<5%), with 2 cases of donor site morbidity after osteoarticular autograft transfer (OAT) autograft harvest. The most common indications for reoperation were repeat debridement/loose body removal. Conclusion: A high rate of return to sport was observed after operative management of capitellar OCD. Patients were more likely to return to their highest level of preoperative sport after OAT autograft compared with debridement or fixation. Significant improvements in elbow range of motion and patient outcomes are

  4. Involvement of mitochondrial dysfunction and ER-stress in the physiopathology of equine osteochondritis dissecans (OCD).

    PubMed

    Desjardin, Clémence; Chat, Sophie; Gilles, Mailys; Legendre, Rachel; Riviere, Julie; Mata, Xavier; Balliau, Thierry; Esquerré, Diane; Cribiu, Edmond P; Betch, Jean-Marc; Schibler, Laurent

    2014-06-01

    Osteochondrosis (OC) is a developmental bone disorder affecting several mammalian species including the horse. Equine OC is described as a focal disruption of endochondral ossification, leading to osteochondral lesions (osteochondritis dissecans, OCD) that may release free bodies within the joint. OCD lesions trigger joint swelling, stiffness and lameness and affects about 30% of the equine population. OCD is considered as multifactorial but its physiopathology is still poorly understood and genes involved in genetic predisposition are still unknown. Our study compared two healthy and two OC-affected 18-month-old French Trotters diagnosed with OCD lesions at the intermediate ridge of the distal tibia. A comparative shot-gun proteomic analysis of non-wounded cartilage and sub-chondral bone from healthy (healthy samples) and OC-affected foals (predisposed samples) identified 83 and 53 modulated proteins, respectively. These proteins are involved in various biological pathways including matrix structure and maintenance, protein biosynthesis, folding and transport, mitochondrial activity, energy and calcium metabolism. Transmission electron microscopy revealed typical features of mitochondrial swelling and ER-stress, such as large, empty mitochondria, and hyper-dilated rough endoplasmic reticulum, in the deep zone of both OC lesions and predisposed cartilage. Abnormal fibril organization surrounding chondrocytes and abnormal features at the ossification front were also observed. Combining these findings with quantitative trait loci and whole genome sequencing results identified about 140 functional candidate genes carrying putative damaging mutations in 30 QTL regions. In summary, our study suggests that OCD lesions may result from defective hypertrophic terminal differentiation associated with mitochondrial dysfunction and ER-stress, leading to impaired cartilage and bone biomechanical properties, making them prone to fractures. In addition, 11 modulated proteins and

  5. Scanning Small- and Wide-Angle X-ray Scattering Microscopy Selectively Probes HA Content in Gelatin/Hydroxyapatite Scaffolds for Osteochondral Defect Repair.

    PubMed

    Altamura, Davide; Pastore, Stella G; Raucci, Maria G; Siliqi, Dritan; De Pascalis, Fabio; Nacucchi, Michele; Ambrosio, Luigi; Giannini, Cinzia

    2016-04-01

    This study is aimed at investigating the structure of a scaffold made of bovine gelatin and hydroxyapatite for bone tissue engineering purposes. In particular, the detailed characterization of such a material has a great relevance because of its application in the healing process of the osteochondral defect that consists of a damage of cartilage and injury of the adjacent subchondral bone, significantly compromising millions of patient's quality of life. Two different techniques exploiting X-ray radiation, with table-top setups, are used: microtomography (micro-CT) and microdiffraction. Micro-CT characterizes the microstructure in the three dimensions at the micrometer scale spatial resolution, whereas microdiffraction provides combined structural/morphological information at the atomic and nanoscale, in two dimensional microscopy images with a hundred micrometer spatial resolution. The combination of these two techniques allowed an appropriate structural characterization for the purpose of validating the engineering approach used for the realization of the hydroxyapatite gradient across the scaffold, with properties close to the natural model. PMID:27020229

  6. Osteochondral differentiation and the emergence of stage-specific osteogenic cell-surface molecules by bone marrow cells in diffusion chambers.

    PubMed

    Bruder, S P; Gazit, D; Passi-Even, L; Bab, I; Caplan, A I

    1990-11-01

    The osteochondral potential and emergence of osteogenic cell-surface molecules by avian marrow cells was evaluated in in vivo diffusion chamber cultures. The chambers were inoculated with unselected marrow cells from young chick tibiae and implanted intraperitoneally into athymic mice. At the light microscopic level, morphologic evidence of de novo bone and cartilage formation, including specific immunostaining by antibody probes, was observed in 14 out of 16 chambers incubated for 20 days or longer. In order to monitor the osteogenic differentiation of the marrow-derived cells, indirect immunofluorescence was performed with monoclonal antibodies against stage-specific cell surface antigens on cells of the embryonic osteogenic lineage. The binding of these and other specific monoclonal antibodies in the developing tissue indicates that the cell surface and extracellular matrix molecules expressed by descendants of marrow-derived mesenchymal progenitor cells are indistinguishable from their in vivo counterparts found in embryonic skeletal structures. Furthermore, the experiments reported here describe the first molecular identification of osteogenic cells by probes which are selective for stage-specific surface antigens on cells of the osteogenic lineage. Importantly, bone formation by these marrow-derived cells appears to occur through a lineage progression which is similar to that observed for embryonic tibial osteoblasts. In summary, these data support the use of diffusion chambers inoculated with avian marrow to study aspects of osteogenic and chondrogenic differentiation.

  7. Radioguided parathyroidectomy in forearm graft for recurrent hyperparathyroidism.

    PubMed

    Ardito, G; Revelli, L; Giustozzi, E; Giordano, A

    2012-01-01

    We report a peculiar case of recurrent hyperparathyroidism caused by hyperplasia of a forearm graft implanted following a total parathyroidectomy in a 38-year-old patient with chronic renal failure. The forearm graft hyperplasia was detected using (99)Tc(m)-sestamibi scanning, which identified hyperplastic transplanted parathyroid tissue in the forearm of the patient. During the initial surgery, the surgeon failed to mark the parathyroid tissue with sutures or clips to facilitate locating it. Therefore, we referred the patient for radioguided surgery. This surgical procedure allowed us to locate and completely remove the hyperfunctioning transplanted parathyroid tissue.

  8. Three-dimensional polycaprolactone-hydroxyapatite scaffolds combined with bone marrow cells for cartilage tissue engineering.

    PubMed

    Wei, Bo; Yao, Qingqiang; Guo, Yang; Mao, Fengyong; Liu, Shuai; Xu, Yan; Wang, Liming

    2015-08-01

    The goal of this study was to investigate the chondrogenic potential of three-dimensional polycaprolactone-hydroxyapatite (PCL-HA) scaffolds loaded with bone marrow cells in vitro and the effect of PCL-HA scaffolds on osteochondral repair in vivo. Here, bone marrow was added to the prepared PCL-HA scaffolds and cultured in chondrogenic medium for 10 weeks. Osteochondral defects were created in the trochlear groove of 29 knees in 17 New Zealand white rabbits, which were then divided into four groups that underwent: implantation of PCL-HA scaffolds (left knee, n = 17; Group 1), microfracture (right knee, n = 6; Group 2), autologous osteochondral transplantation (right knee, n = 6; Group 3), and no treatment (right knee, n = 5; Control). Extracellular matrix produced by bone marrow cells covered the surface and filled the pores of PCL-HA scaffolds after 10 weeks in culture. Moreover, many cell-laden cartilage lacunae were observed, and cartilage matrix was concentrated in the PCL-HA scaffolds. After a 12-week repair period, Group 1 showed excellent vertical and lateral integration with host bone, but incomplete cartilage regeneration and matrix accumulation. An uneven surface of regenerated cartilage and reduced distribution of cartilage matrix were observed in Group 2. In addition, abnormal bone growth and unstable integration between repaired and host tissues were detected. For Group 3, the integration between transplanted and host cartilage was interrupted. Our findings indicate that the PCL-HA scaffolds loaded with bone marrow cells improved chondrogenesis in vitro and implantation of PCL-HA scaffolds for osteochondral repairenhanced integration with host bone. However, cartilage regeneration remained unsatisfactory. The addition of trophic factors or the use of precultured cell-PCL-HA constructs for accelerated osteochondral repair requires further investigation.

  9. Improved quality of cartilage repair by bone marrow mesenchymal stem cells for treatment of an osteochondral defect in a cynomolgus macaque model

    PubMed Central

    Araki, Susumu; Imai, Shinji; Ishigaki, Hirohito; Mimura, Tomohiro; Nishizawa, Kazuya; Ueba, Hiroaki; Kumagai, Kousuke; Kubo, Mitsuhiko; Mori, Kanji; Ogasawara, Kazumasa; Matsusue, Yoshitaka

    2015-01-01

    Background and purpose Integration of repaired cartilage with surrounding native cartilage is a major challenge for successful tissue-engineering strategies of cartilage repair. We investigated whether incorporation of mesenchymal stem cells (MSCs) into the collagen scaffold improves integration and repair of cartilage defects in a cynomolgus macaque model. Methods Cynomolgus macaque bone marrow-derived MSCs were isolated and incorporated into type-I collagen gel. Full-thickness osteochondral defects (3 mm in diameter, 5 mm in depth) were created in the patellar groove of 36 knees of 18 macaques and were either left untreated (null group, n = 12), had collagen gel alone inserted (gel group, n = 12), or had collagen gel incorporating MSCs inserted (MSC group, n = 12). After 6, 12, and 24 weeks, the cartilage integration and tissue response were evaluated macroscopically and histologically (4 null, 4 gel, and 4 MSC knees at each time point). Results The gel group showed most cartilage-rich reparative tissue covering the defect, owing to formation of excessive cartilage extruding though the insufficient subchondral bone. Despite the fact that a lower amount of new cartilage was produced, the MSC group had better-quality cartilage with regular surface, seamless integration with neighboring naïve cartilage, and reconstruction of trabecular subchondral bone. Interpretation Even with intensive investigation, MSC-based cell therapy has not yet been established in experimental cartilage repair. Our model using cynomolgus macaques had optimized conditions, and the method using MSCs is superior to other experimental settings, allowing the possibility that the procedure might be introduced to future clinical practice. PMID:25175660

  10. Arthroscopic Treatment of Chondral and Osteochondral Defects in the Ankle Using the Autologous Matrix-Induced Chondrogenesis Technique

    PubMed Central

    Piontek, Tomasz; Bąkowski, Paweł; Ciemniewska-Gorzela, Kinga; Naczk, Jakub

    2015-01-01

    One of the greatest challenges nowadays facing orthopaedic surgeons around the world is the problem of articular cartilage defects and their treatment. The autologous matrix-induced chondrogenesis technique is based on 2 elements—drilling into bones and matrix application. The purpose of this article is to present the surgical technique of arthroscopic treatment of chondral or osteochondral defects in the ankle using the autologous matrix-induced chondrogenesis technique. PMID:26697305

  11. Graft-related endocarditis caused by Neosartorya fischeri var. spinosa.

    PubMed Central

    Summerbell, R C; de Repentigny, L; Chartrand, C; St Germain, G

    1992-01-01

    The first case of endocarditis caused by Neosartorya fischeri var. spinosa is reported. The patient was a child who received a calf pericardium graft after removal of a previously inserted Dacron graft associated with deterioration of adjacent tissue. Copious vegetations removed from the heart were found to be composed of septate hyaline fungal filaments. The fungus was recognized in culture by its bivalved, winged, spiny ascospores, its Aspergillus fischerianus anamorph, and its thermotolerance. Images PMID:1624579

  12. Ulnar Nerve Injury after Flexor Tendon Grafting.

    PubMed

    McCleave, Michael John

    2016-10-01

    A 43-year-old female is presented who underwent a two-stage tendon reconstruction and developed a low ulnar nerve palsy postoperatively. Exploration found that the tendon graft was passing through Guyon's canal and that the ulnar nerve was divided. This is a previously unreported complication. The reconstruction is discussed, the literature reviewed and a guide is given on how to identify the correct tissue plane when passing a tendon rod. PMID:27595967

  13. Graft selection in anterior cruciate ligament reconstruction.

    PubMed

    Miller, Suzanne L; Gladstone, James N

    2002-10-01

    Selecting the appropriate graft for ACL reconstruction depends on numerous factors including surgeon philosophy and experience, tissue availability (affected by anatomical anomalies or prior injury or surgery), and patient activity level and desires. Although the patella tendon autograft has the widest experience in the literature, and is probably the most commonly used graft source, this must be tempered with the higher reported incidences of potential morbidity and pitfalls associated with its use. The hamstring tendons are gaining increasing popularity, mostly due to reduced harvest morbidity and improved soft tissue fixation techniques, and many recent studies in the literature report equal results to BTB ACL reconstruction with respect to functional outcome and patient satisfaction. On the other hand, many of these studies report higher degrees of instrument (KT-100) tested laxity for hamstring reconstruction, and some have reported lower returns to preinjury levels of activity. One question that remains to be addressed is how closely objectively measured laxity tests correlate with subjectively assessed outcomes and ability to return to high levels of competitive sports. Allograft use, which decreased in popularity during the 1990s, appears to be undergoing a resurgence, with better sterilization processes and new graft sources (tibialis tendons), leading to increased availability and improved fixation techniques. The benefits of decreased surgical morbidity and easier rehabilitation must be weighed against the potential for greater failure of biologic incorporation, infection, and possibly slower return to activities. In our practice, for high-demand individuals (those playing cutting, pivoting, or jumping sports and skiing) BTB tends to be the graft of choice. For lower demand or older individuals, hamstring reconstructions will be performed. Allograft tissue will be used in older individuals (generally over 45 years old), those with signs of arthritis (and

  14. Graft selection in anterior cruciate ligament reconstruction.

    PubMed

    Miller, Suzanne L; Gladstone, James N

    2002-10-01

    Selecting the appropriate graft for ACL reconstruction depends on numerous factors including surgeon philosophy and experience, tissue availability (affected by anatomical anomalies or prior injury or surgery), and patient activity level and desires. Although the patella tendon autograft has the widest experience in the literature, and is probably the most commonly used graft source, this must be tempered with the higher reported incidences of potential morbidity and pitfalls associated with its use. The hamstring tendons are gaining increasing popularity, mostly due to reduced harvest morbidity and improved soft tissue fixation techniques, and many recent studies in the literature report equal results to BTB ACL reconstruction with respect to functional outcome and patient satisfaction. On the other hand, many of these studies report higher degrees of instrument (KT-100) tested laxity for hamstring reconstruction, and some have reported lower returns to preinjury levels of activity. One question that remains to be addressed is how closely objectively measured laxity tests correlate with subjectively assessed outcomes and ability to return to high levels of competitive sports. Allograft use, which decreased in popularity during the 1990s, appears to be undergoing a resurgence, with better sterilization processes and new graft sources (tibialis tendons), leading to increased availability and improved fixation techniques. The benefits of decreased surgical morbidity and easier rehabilitation must be weighed against the potential for greater failure of biologic incorporation, infection, and possibly slower return to activities. In our practice, for high-demand individuals (those playing cutting, pivoting, or jumping sports and skiing) BTB tends to be the graft of choice. For lower demand or older individuals, hamstring reconstructions will be performed. Allograft tissue will be used in older individuals (generally over 45 years old), those with signs of arthritis (and

  15. Multimodal imaging of vascular grafts using time-resolved fluorescence and ultrasound

    NASA Astrophysics Data System (ADS)

    Fatakdawala, Hussain; Griffiths, Leigh G.; Wong, Maelene L.; Humphrey, Sterling; Marcu, Laura

    2015-02-01

    The translation of engineered tissues into clinic requires robust monitoring of tissue development, both in vitro and in vivo. Traditional methods for the same are destructive, inefficient in time and cost and do not allow time-lapse measurements from the same sample or animal. This study reports on the ability of time-resolved fluorescence and ultrasound measurements for non-destructive characterization of explanted tissue engineered vascular grafts. Results show that TRFS and FLIm are able to assess alterations in luminal composition namely elastin, collagen and cellular (hyperplasia) content via changes in fluorescence lifetime values between normal and grafted tissue. These observations are complemented by structural changes observed in UBM pertaining to graft integration and intimal thickness over the grafted region. These results encourage the future application of a catheter-based technique that combines these imaging modalities for non-destructive characterization of vascular grafts in vivo.

  16. Grafts for Ridge Preservation

    PubMed Central

    Jamjoom, Amal; Cohen, Robert E.

    2015-01-01

    Alveolar ridge bone resorption is a biologic phenomenon that occurs following tooth extraction and cannot be prevented. This paper reviews the vertical and horizontal ridge dimensional changes that are associated with tooth extraction. It also provides an overview of the advantages of ridge preservation as well as grafting materials. A Medline search among English language papers was performed in March 2015 using alveolar ridge preservation, ridge augmentation, and various graft types as search terms. Additional papers were considered following the preliminary review of the initial search that were relevant to alveolar ridge preservation. The literature suggests that ridge preservation methods and augmentation techniques are available to minimize and restore available bone. Numerous grafting materials, such as autografts, allografts, xenografts, and alloplasts, currently are used for ridge preservation. Other materials, such as growth factors, also can be used to enhance biologic outcome. PMID:26262646

  17. The Palatal Bone Block Graft for Onlay Grafting Combined with Maxillary Implant Placement: A Case Series.

    PubMed

    Gluckman, Howard; Du Toit, Jonathan; Salama, Maurice

    2016-01-01

    The aim of this study was to introduce an intraoral bone block harvesting technique--the palatal bone block graft (PBBG)--as an alternative harvest site for autogenous bone blocks. The PBBG technique was used to onlay graft esthetic zone defects simultaneous to implant placement in five patients. Measurable objectives were used to evaluate outcomes, and treatment was reassessed at up to 6 years. Defects of the maxilla were successfully grafted with PBBG in all five cases, and tissues remained stable at 1- and 6-year follow-ups. Harvesting an autogenous bone block from the palate is an advantageous, predictable, and reproducible method for augmenting buccofacial defects at implant placement, and may be considered as an alternative to conventional intraoral bone block donor sites when treating the maxilla.

  18. Fluorescence spectroscopy for assessment of liver transplantation grafts concerning graft viability and patient survival

    NASA Astrophysics Data System (ADS)

    Vollet Filho, José D.; da Silveira, Marina R.; Castro-e-Silva, Orlando; Bagnato, Vanderlei S.; Kurachi, Cristina

    2015-06-01

    Evaluating transplantation grafts at harvest is essential for its success. Laser-induced fluorescence spectroscopy (LIFS) can help monitoring changes in metabolic/structural conditions of tissue during transplantation. The aim of the present study is to correlate LIFSobtained spectra of human hepatic grafts during liver transplantation with post-operative patients' mortality rate and biochemical parameters, establishing a method to exclude nonviable grafts before implantation. Orthotopic liver transplantation, piggyback technique was performed in 15 patients. LIFS was performed under 408nm excitation. Collection was performed immediately after opening donor's abdominal cavity, after cold perfusion, end of back-table period, and 5 min and 1 h after warm perfusion at recipient. Fluorescence information was compared to lactate, creatinine, bilirubin and INR levels and to survival status. LIFS was sensitive to liver changes during transplantation stages. Study-in-progress; initial results indicate correlation between fluorescence and life/death status of patients.

  19. Graft-versus-host disease

    MedlinePlus

    GVHD; Bone marrow transplant - graft-versus-host disease; Stem cell transplant - graft-versus-host disease; Allogeneic transplant - ... GVHD may occur after a bone marrow, or stem cell, transplant in which someone receives bone marrow ...

  20. Accelerated adhesion of grafted skin by laser-induced stress wave-based gene transfer of hepatocyte growth factor

    NASA Astrophysics Data System (ADS)

    Aizawa, Kazuya; Sato, Shunichi; Terakawa, Mitsuhiro; Saitoh, Daizoh; Tsuda, Hitoshi; Ashida, Hiroshi; Obara, Minoru

    2009-11-01

    Gene therapy using wound healing-associated growth factor gene has received much attention as a new strategy for improving the outcome of tissue transplantation. We delivered plasmid DNA coding for human hepatocyte growth factor (hHGF) to rat free skin grafts by the use of laser-induced stress waves (LISWs); autografting was performed with the grafts. Systematic analysis was conducted to evaluate the adhesion properties of the grafted tissue; angiogenesis, cell proliferation, and reepithelialization were assessed by immunohistochemistry, and reperfusion was measured by laser Doppler imaging as a function of time after grafting. Both the level of angiogenesis on day 3 after grafting and the increased ratio of blood flow on day 4 to that on day 3 were significantly higher than those in five control groups: grafting with hHGF gene injection alone, grafting with control plasmid vector injection alone, grafting with LISW application alone, grafting with LISW application after control plasmid vector injection, and normal grafting. Reepithelialization was almost completed on day 7 even at the center of the graft with LISW application after hHGF gene injection, while it was not for the grafts of the five control groups. These findings demonstrate the validity of our LISW-based HGF gene transfection to accelerate the adhesion of grafted skins.

  1. Impact of static cold storage VS hypothermic machine preservation on ischemic kidney graft: inflammatory cytokines and adhesion molecules as markers of ischemia/reperfusion tissue damage. Our preliminary results.

    PubMed

    Tozzi, Matteo; Franchin, Marco; Soldini, Gabriele; Ietto, Giuseppe; Chiappa, Corrado; Maritan, Emanuele; Villa, Francesca; Carcano, Giulio; Dionigi, Renzo

    2013-01-01

    At the present time, deceased heart-beating donor kidney allografts are usually stored cold. Extended-criteria donor (ECD) grafts show higher sensitivity to ischemia-reperfusion damage than standard kidneys. The increasing use of marginal organs in clinical transplantation urgently requires a more effective preservation system. Pulsatile hypothermic machine perfusion has shown major advantages over static cold storage in terms of reduced organ injury during preservation and improved early graft function. This preliminary study aims to compare pulsatile hypothermic machine perfusion and static cold storage of kidney allografts, outlining differences in the levels of early inflammatory cytokines (TNF-α, IL-2 and IL-1β) and soluble intracellular adhesion molecule (sICAM-1) in perfusion and preservation liquid.

  2. High intensity focused ultrasound as a tool for tissue engineering: Application to cartilage.

    PubMed

    Nover, Adam B; Hou, Gary Y; Han, Yang; Wang, Shutao; O'Connell, Grace D; Ateshian, Gerard A; Konofagou, Elisa E; Hung, Clark T

    2016-02-01

    This article promotes the use of High Intensity Focused Ultrasound (HIFU) as a tool for affecting the local properties of tissue engineered constructs in vitro. HIFU is a low cost, non-invasive technique used for eliciting focal thermal elevations at variable depths within tissues. HIFU can be used to denature proteins within constructs, leading to decreased permeability and potentially increased local stiffness. Adverse cell viability effects remain restricted to the affected area. The methods described in this article are explored through the scope of articular cartilage tissue engineering and the fabrication of osteochondral constructs, but may be applied to the engineering of a variety of different tissues. PMID:26724968

  3. Gingival recession coverage: 
Do we still need autogenous grafts?

    PubMed

    Kasaj, Adrian

    2016-01-01

    A variety of periodontal plastic surgical techniques have been proposed to obtain root coverage of gingival recession defects. All of the available root coverage procedures are able to provide significant root coverage for Miller Class I and II recession-type defects. However, only the subepithelial connective tissue graft in conjunction with a coronally advanced flap appears consistently effective across all clinical parameters, and is therefore currently considered the gold standard for gingival recession therapy. The major shortcomings of connective tissue graft procedures include patient morbidity associated with the second surgical site and limited availability of palatal donor tissue. More recently, 3D collagen matrices of human and porcine origin have been introduced as possible alternatives to autogenous connective tissue grafts in recession coverage procedures. This paper aims to give an overview on the possible use of collagen matrices as soft tissue substitutes and a possible alternative to connective tissue grafts in the surgical treatment of gingival recession defects. PMID:27660847

  4. Biodegradable, thermoplastic polyurethane grafts for small diameter vascular replacements.

    PubMed

    Bergmeister, Helga; Seyidova, Nargiz; Schreiber, Catharina; Strobl, Magdalena; Grasl, Christian; Walter, Ingrid; Messner, Barbara; Baudis, Stefan; Fröhlich, Sophie; Marchetti-Deschmann, Martina; Griesser, Markus; di Franco, Matt; Krssak, Martin; Liska, Robert; Schima, Heinrich

    2015-01-01

    Biodegradable vascular grafts with sufficient in vivo performance would be more advantageous than permanent non-degradable prostheses. These constructs would be continuously replaced by host tissue, leading to an endogenous functional implant which would adapt to the need of the patient and exhibit only limited risk of microbiological graft contamination. Adequate biomechanical strength and a wall structure which promotes rapid host remodeling are prerequisites for biodegradable approaches. Current approaches often reveal limited tensile strength and therefore require thicker or reinforced graft walls. In this study we investigated the in vitro and in vivo biocompatibility of thin host-vessel-matched grafts (n=34) formed from hard-block biodegradable thermoplastic polyurethane (TPU). Expanded polytetrafluoroethylene (ePTFE) conduits (n=34) served as control grafts. Grafts were analyzed by various techniques after retrieval at different time points (1 week; 1, 6, 12 months). TPU grafts showed significantly increased endothelial cell proliferation in vitro (P<0.001). Population by host cells increased significantly in the TPU conduits within 1 month of implantation (P=0.01). After long-term implantation, TPU implants showed 100% patency (ePTFE: 93%) with no signs of aneurysmal dilatation. Substantial remodeling of the degradable grafts was observed but varied between subjects. Intimal hyperplasia was limited to ePTFE conduits (29%). Thin-walled TPU grafts offer a new and desirable form of biodegradable vascular implant. Degradable grafts showed equivalent long-term performance characteristics compared to the clinically used, non-degradable material with improvements in intimal hyperplasia and ingrowth of host cells.

  5. Peripheral Blood Mononuclear Cells Enhance Cartilage Repair in in vivo Osteochondral Defect Model

    PubMed Central

    Hopper, Niina; Wardale, John; Brooks, Roger; Power, Jonathan; Rushton, Neil; Henson, Frances

    2015-01-01

    This study characterized peripheral blood mononuclear cells (PBMC) in terms of their potential in cartilage repair and investigated their ability to improve the healing in a pre-clinical large animal model. Human PBMCs were isolated with gradient centrifugation and adherent PBMC’s were evaluated for their ability to differentiate into adipogenic, chondrogenic and osteogenic lineages and also for their expression of musculoskeletal genes. The phenotype of the PBMCs was evaluated using Stro-1, CD34, CD44, CD45, CD90, CD106, CD105, CD146 and CD166 cell surface markers. Osteochondral defects were created in the medial femoral condyle (MFC) of 24 Welsh mountain sheep and evaluated at a six month time point. Four cell treatment groups were evaluated in combination with collagen-GAG-scaffold: (1) MSC alone; (2) MSCs and PBMCs at a ratio of 20:1; (3) MSCs and PBMC at a ratio of 2:1 and (4) PBMCs alone. Samples from the surgical site were evaluated for mechanical properties, ICRS score and histological repair. Fresh PBMC samples were 90% positive for hematopoietic cell surface markers and negative for the MSC antibody panel (<1%, p = 0.006). However, the adherent PBMC population expressed mesenchymal stem cell markers in hypoxic culture and lacked CD34/45 positive cells (<0.2%). This finding demonstrated that the adherent cells had acquired an MSC-like phenotype and transformed in hypoxia from their original hematopoietic lineage. Four key genes in muskuloskeletal biology were significantly upregulated in adherent PBMCs by hypoxia: BMP2 4.2-fold (p = 0.0007), BMP6 10.7-fold (p = 0.0004), GDF5 2.0-fold (p = 0.002) and COL1 5.0-fold (p = 0.046). The monolayer multilineage analysis confirmed the trilineage mesenchymal potential of the adherent PBMCs. PBMC cell therapy was equally good as bone marrow MSC therapy for defects in the ovine large animal model. Our results show that PBMCs support cartilage healing and oxygen tension of the environment was found to have a key

  6. Evidence of a Major Gene From Bayesian Segregation Analyses of Liability to Osteochondral Diseases in Pigs

    PubMed Central

    Kadarmideen, Haja N.; Janss, Luc L. G.

    2005-01-01

    Bayesian segregation analyses were used to investigate the mode of inheritance of osteochondral lesions (osteochondrosis, OC) in pigs. Data consisted of 1163 animals with OC and their pedigrees included 2891 animals. Mixed-inheritance threshold models (MITM) and several variants of MITM, in conjunction with Markov chain Monte Carlo methods, were developed for the analysis of these (categorical) data. Results showed major genes with significant and substantially higher variances (range 1.384–37.81), compared to the polygenic variance (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{{\\sigma}}}_{{\\mathrm{u}}}^{2}\\end{equation*}\\end{document}). Consequently, heritabilities for a mixed inheritance (range 0.65–0.90) were much higher than the heritabilities from the polygenes. Disease allele frequencies range was 0.38–0.88. Additional analyses estimating the transmission probabilities of the major gene showed clear evidence for Mendelian segregation of a major gene affecting osteochondrosis. The variants, MITM with informative prior on \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{{\\sigma}}}_{{\\mathrm{u}}}^{2}\\end{equation*}\\end{document}, showed significant improvement in marginal distributions and accuracy of parameters. MITM with a “reduced polygenic model” for parameterization of polygenic effects avoided convergence problems and poor mixing encountered in an “individual polygenic model.” In all cases, “shrinkage estimators” for fixed effects avoided unidentifiability for these parameters. The mixed

  7. The Incidence of Surgery in Osteochondritis Dissecans in Children and Adolescents

    PubMed Central

    Weiss, Jennifer M.; Nikizad, Hooman; Shea, Kevin G.; Gyurdzhyan, Samvel; Jacobs, John C.; Cannamela, Peter C.; Kessler, Jeffrey I.

    2016-01-01

    Background: The frequency of osteochondritis dissecans (OCD), a disorder of the subchondral bone and articular cartilage, is not well described. Purpose: To assess the frequency of pediatric OCD lesions that progress to surgery based on sex, joint involvement, and age. Study Design: Descriptive epidemiology study. Methods: A retrospective chart review (2007-2011) was performed on OCD. Inclusion criteria included OCD of any joint and patients aged 2 to 19 years. Exclusion criteria included traumatic osteochondral fractures or coexistence of non-OCD intra-articular lesions. Differences in progression toward surgery were compared between age groups, sex, and joint location. Logistical regression analysis was performed by sex, age, and ethnicity. Results: Overall, 317 patients with a total of 334 OCD lesions were found. The majority of lesions (61.7%) were in the knee, with ankle, elbow, shoulder, and foot lesions representing 25.4%, 12.0%, 0.6%, and 0.3% of all lesions, respectively. The majority of joints needing surgery were in the knee (58.5%), with ankle and elbow lesions representing 22.9% and 18.6% of surgeries performed, respectively. The percentage of all OCD lesions progressing to surgery was 35.3%; surgical progression for knee, ankle, and elbow joints was 33.5%, 31.8%, and 55.0%, respectively. Logistic regression analysis found no statistically significant different risk of progressing to surgery for OCD of the knee, elbow, and ankle between sexes. Patients aged 12 to 19 years had a 7.4-times greater risk of progression to surgery for knee OCD lesions than 6- to 11-year-olds. Patients aged 12 to 19 years were 8.2 times more likely to progress to surgery for all OCD lesions than patients aged 6 to 11 years. Progression to surgery of ankle OCD did not significantly differ based on location. Three of 4 trochlear lesions progressed to surgery, along with 1 of 1 tibial, 1 of 3 patellar, 40.3% of lateral femoral condylar, and 28.2% of medial femoral condylar

  8. A new type of Schwann cell graft transplantation to promote optic nerve regeneration in adult rats.

    PubMed

    Fang, Yuan; Mo, Xiaofen; Guo, Wenyi; Zhang, Meng; Zhang, Peihua; Wang, Yan; Rong, Xianfang; Tian, Jie; Sun, Xinghuai

    2010-12-01

    Like other parts of the central nervous system, the adult mammalian optic nerve is difficult to regenerate after injury. Transplantation of the peripheral nerve or a Schwann cell (SC) graft can promote injured axonal regrowth. We tried to develop a new type of tissue-engineered SC graft that consisted of SCs seeded onto a poly(lactic-co-glycolic acid)/chitosan conduit. Meanwhile, SCs were transfected along the ciliary neurotrophic factor (CNTF) gene in vitro by electroporation to increase their neurotrophic effect. Four weeks after transplantation, GAP-43 labelled regenerating axons were found in the SC grafts, and axons in the CNTF-SC graft were longer than those in the SC graft. Tissue-engineered SC grafts can provide a feasible environment for optic nerve regeneration and may become an alternative for bridging damaged nerves and repairing nerve defects in the future.

  9. Transplantation of human adipose tissue to nude mice.

    PubMed

    Bach-Mortensen, N; Romert, P; Ballegaard, S

    1976-08-01

    Human adipose tissue was transplanted to the mouse mutant nude (nu/nu). All the grafts were accepted and contained fat cells easily distinguishable from those of the mouse. No detectable relation between the histological pictures before and after grafting was found. In some transplants nerve tissue, and in others macrophages containing fat droplets, were found. The fat tissue graft might be useful for investigation of the influence of various hormones on human fat cells.

  10. Grafting effects on vegetable quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the United States, vegetable grafting is rare and few experiments have been done to determine optimal grafting procedures and production practices for different geographical and climatic regions in America. Grafting vegetables to control soilborne disease is a common practice in Asia, parts of E...

  11. Dermofat graft in deep nasolabial fold and facial rhytidectomy.

    PubMed

    Hwang, Kun; Han, Jin Yi; Kim, Dae Joong

    2003-01-01

    Fat and dermis or the combined tissues are used commonly in augmentation of the nasolabial fold. Guyuron obtained the dermofat graft from either the suprapubic or the groin region. The thickness of the preauricular skin was measured in seven Korean cadavers, five male and two female. We used the dermofat graft out of the preauricular skin remnant after facial rhytidectomy to augment the deep nasolabial fold in a patient. The average thickness of the epidermis was 56 +/- 12 microm, the dermis was 1820 +/- 265 microm thick, and the subcutaneous tissue was 4783 +/- 137 microm. More dense connective tissues, such as SMAS, are seen in the preauricular skin. The dermofat graft was easily obtained and prepared from the leftover preauricular skin after dissection of the lax skin in face lifting. This technique could be employed effectively and successfully to alleviate a deep nasolabial fold and concomitant facial rhytidectomy in an Asian with a thick preauricular skin.

  12. A Developmental Framework for Graft Formation and Vascular Reconnection in Arabidopsis thaliana

    PubMed Central

    Melnyk, Charles W; Schuster, Christoph; Leyser, Ottoline; Meyerowitz, Elliot M

    2016-01-01

    Summary Background Plant grafting is a biologically important phenomenon involving the physical joining of two plants to generate a chimeric organism. It is widely practiced in horticulture and used in science to study the long distance movement of molecules. Despite its widespread use, the mechanism of graft formation and vascular reconnection is not well understood. Here, we study the dynamics and mechanisms of vascular regeneration in Arabidopsis thaliana during graft formation when the vascular strands are severed and reconnected. Results We demonstrate a temporal separation between tissue attachment, phloem connection, root growth and xylem connection. By analysing cell division patterns and hormone responses at the graft junction, we found that tissues initially show an asymmetry in cell division, cell differentiation and gene expression, and through contact with the opposing tissue, lose this asymmetry and reform the vascular connection. In addition, we identified genes involved in vascular reconnection at the graft junction, and demonstrate that these auxin response genes are required below the graft junction. Conclusions We propose an inter-tissue communication process that occurs at the graft junction and promotes vascular connection by tissue-specific auxin responses involving ABERRANT LATERAL ROOT FORMATION 4 (ALF4). Our study has implications for phenomena where forming vascular connections are important including graft formation, parasitic plant infection and wound healing. PMID:25891401

  13. Grafting for disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary purpose of grafting vegetables worldwide has been to provide resistance to soil-borne diseases. The potential loss of methyl bromide as a soil fumigant combined with pathogen resistance to commonly used pesticides will make resistance to soil-borne pathogens even more important in the fu...

  14. Acrylonitrile grafted to PVDF

    DOEpatents

    Yang, Jin; Eitouni, Hany Basam

    2015-03-31

    PVDF-g-PAN has been synthesized by grafting polyacrylonitrile onto polyvinylidene fluoride using an ATRP/AGET method. The novel polymer is ionically conducive and has much more flexibility than PVDF alone, making it especially useful either as a binder in battery cell electrodes or as a polymer electrolyte in a battery cell.

  15. Vascular graft infections.

    PubMed

    Hasse, Barbara; Husmann, Lars; Zinkernagel, Annelies; Weber, Rainer; Lachat, Mario; Mayer, Dieter

    2013-01-01

    Vascular procedures are rarely complicated by infection, but if prosthetic vascular graft infection (PVGI) occurs, morbidity and mortality are high. Several patient-related, surgery-related and postoperative risk factors are reported, but they are not well validated. PVGI is due to bacterial colonisation of the wound and the underlying prosthetic graft, generally as a result of direct contamination during the operative procedure, mainly from the patient's skin or adjacent bowel. There is no consensus on diagnostic criteria or on the best management of PVGI. On the basis of reported clinical studies and our own experience, we advocate a surgical approach combining repeated radical local debridement, with graft preservation whenever possible or partial excision of the infected graft, depending on its condition, plus simultaneous negative-pressure wound therapy (NPWT). In addition, antimicrobial therapy is recommended, but there is no consensus on which classes of agent are adequate for the treatment of PVGI and whether certain infections may be treated by means of NPWT alone. Since staphylococci and Gram-negative rods are likely to be isolated, empirical treatment might include a penicillinase-resistant beta-lactam or a glycopeptide, plus an aminoglycoside, the latter for Gram-negative coverage and synergistic treatment of Gram-positive cocci. Additionally, empirical treatment might include rifampicin since it penetrates well into biofilms.

  16. Fresh Versus Frozen Engineered Bone–Ligament–Bone Grafts for Sheep Anterior Cruciate Ligament Repair

    PubMed Central

    Mahalingam, Vasudevan D.; Behbahani-Nejad, Nilofar; Ronan, Elizabeth A.; Olsen, Tyler J.; Smietana, Michael J.; Wojtys, Edward M.; Wellik, Deneen M.; Arruda, Ellen M.

    2015-01-01

    Surgical intervention is often required to restore knee instability in patients with anterior cruciate ligament (ACL) injury. The most commonly used grafts for ACL reconstruction are tendon autografts or allografts. These current options, however, have shown failure rates requiring revision and continued instability in the long term. The mismatched biomechanical properties of the current tendon grafts compared with native ACL tissue are thought to contribute to these poor outcomes and potential risk of early onset osteoarthritis. As a possible solution to these issues, our laboratory has fabricated tissue-engineered ligament constructs that exhibit structural and functional properties similar to those of native ACL tissue after 6 months implantation. In addition, these tissue-engineered grafts achieve vascular and neural development that exceeds those of patellar tendon grafts. However, the utility of our tissue-engineered grafts is limited by the labor-intensive method required to produce the constructs and the need to use the constructs fresh, directly from the cell culturing system. Ideally, these constructs would be fabricated and stored until needed. Thus, in this study, we investigated the efficacy of freezing our tissue-engineered constructs as a method of preservation before use for ACL reconstruction. We hypothesized that frozen constructs would have similar histological and biomechanical outcomes compared with our fresh model. Our results showed that 6 months postimplantation as an ACL replacement graft, both our tissue-engineered fresh and frozen grafts demonstrated similar mechanical and histological outcomes, indicating that freezing is a suitable method for preserving and storing our graft before ACL reconstruction. The ability to use frozen constructs significantly increases the versatility of our graft technology expanding the clinical utility of our graft. PMID:25397990

  17. Development of tissue bank

    PubMed Central

    Narayan, R. P.

    2012-01-01

    The history of tissue banking is as old as the use of skin grafting for resurfacing of burn wounds. Beneficial effects of tissue grafts led to wide spread use of auto and allograft for management of varied clinical conditions like skin wounds, bone defects following trauma or tumor ablation. Availability of adequate amount of tissues at the time of requirement was the biggest challenge that forced clinicians to find out techniques to preserve the living tissue for prolonged period of time for later use and thus the foundation of tissue banking was started in early twentieth century. Harvesting, processing, storage and transportation of human tissues for clinical use is the major activity of tissue banks. Low temperature storage of processed tissue is the best preservation technique at present. Tissue banking organization is a very complex system and needs high technical expertise and skilled personnel for proper functioning in a dedicated facility. A small lapse/deviation from the established protocol leads to loss of precious tissues and or harm to recipients as well as the risk of transmission of deadly diseases and tumors. Strict tissue transplant acts and stringent regulations help to streamline the whole process of tissue banking safe for recipients and to community as whole. PMID:23162240

  18. Failed vascularized fibular graft in treatment of osteonecrosis of the femoral head. A histopathological analysis

    PubMed Central

    MELONI, MARIA CHIARA; HOEDEMAEKER, W. RUSSALKA; FORNASIER, VICTOR

    2016-01-01

    Purpose vascularized fibular grafting has been used to treat osteonecrosis of the femoral head in younger patients. Although the results described in the literature are promising, the failure rate is still significant, especially in steroid users. This study was undertaken to learn more, on a histopathological level, about the mechanism of vascularized fibular graft failure. Methods fifteen femoral heads removed at conversion to total hip arthroplasty were analyzed. The case load comprised 10 men and 5 women. They ranged in age from 28 to 39 years and had a median age of 35 years. The interval between the vascularized fibular implant procedure and the conversion to total hip arthroplasty ranged from 22 months to 30 months; the median interval was 26 months. All the patients were steroid users. The heads were sectioned and axial and coronal sections were taken and stained using the WHO method (hematoxylin, phloxine, saffron and Alcian green). A quantitative and qualitative analysis of graft-host interaction at the head (zone 1), neck (zone 2) and epiphysis (zone 3) was performed. Results all the specimens showed recognizable collapse of the articular surface over the area of necrosis. Thirteen femoral heads showed the presence of an osteochondral flap attached only at the margins of the area of avascular necrosis, and 10 of these 13 femoral heads also showed loss of the articulating surface with an ulcer crater corresponding to the exposed area of avascular necrosis. Conclusions vascularized fibular graft failure seems to be related to a negative effect of creeping substitution: the revascularization becomes a negative force as it supports unbalanced bone resorption, which, as is well known, is enhanced by corticosteroids. Clinical relevance creeping substitution is an undermining force in the repair and revascularization of the necrotic area in the femoral head. PMID:27386444

  19. Histopathological evaluation of woven and knitted Dacron grafts for right ventricular conduits: a comparative experimental study.

    PubMed

    Haverich, A; Oelert, H; Maatz, W; Borst, H G

    1984-05-01

    Composite extracardiac conduits consisting of a low-porosity woven graft and a high-porosity knitted double-velour Dacron graft presealed with fibrin glue were implanted between the right ventricle and the pulmonary artery in 6 dogs under partial heparinization. Two grafts were explanted after 6 weeks, 2 after 12 weeks, and 2 after 6 months. The healing properties of both types of prosthesis were studied macroscopically, under light microscopy, and with scatter electron microscopy. Spontaneous peeling of both the inner and outer capsules of the graft occurred in 3 of 6 woven prostheses during transection. In the remaining 3, peeling could be easily induced by blunt dissection; this was impossible in the knitted grafts. Microscopically, in a comparison of the different weaves after identical time intervals, the inner capsule was noticeably thicker in woven than in knitted grafts. Transtitial ingrowth of fibroblastic tissue could be observed in knitted grafts after 6 weeks; only poor transmural tissue bridging was detectable in woven prostheses after 6 months. Neovascularization of the inner capsule was detectable earlier and was more advanced toward the luminal surface of highly porous grafts. In conclusion, knitted grafts in the position of extracardiac right ventricular conduits showed firmer attachment of both inner and outer capsules to the prosthetic material. Also, the inner capsule remained thinner and revealed a higher degree of neovascularization than in the woven Dacron grafts.

  20. Hand rejuvenation with structural fat grafting.

    PubMed

    Coleman, Sydney R

    2002-12-01

    A simple, reliable technique of autologous fat grafting for long-lasting rejuvenation of the dorsum of the hand is presented. With this technique, small intact parcels of fatty tissue are harvested with a syringe and a blunt 3-mm cannula. Then, most of the nonviable components are removed from the harvested subcutaneous material by centrifugation, decanting, and wicking. Finally, a 17-gauge blunt cannula places the fat in minuscule parcels of tissue with many passes through five or six tiny incisions in the hand. Separation of the tiny parcels of fat maximizes contact between the surfaces of the transplanted fat and surrounding recipient tissues to encourage integration, anchoring, and long-term survival. Structured, purposeful placement of a thin layer of transplanted fat rejuvenates the dorsal hand by restoring a slight fullness to atrophic subcutaneous tissue, by softening the color and definition of exposed extensor tendons and dorsal hand veins, and by supporting the aging skin.

  1. Lunate Osteochondral Fracture Treated by Excision: A Case Report and Literature Review

    PubMed Central

    Saberi, Sadegh; Arabzadeh, Aidin; Farhoud, Amir Reza

    2016-01-01

    Introduction Lunate fracture is a rare injury. Most reports are associated with other wrist injuries such as perilunate dislocation and distal radius fracture. Isolated lunate fracture has been reported even more rarely. The choice of treatment and outcomes are consequently undetermined. Case Presentation In this case report we will describe a lunate avulsion fracture as an isolated injury after a fall from nine meters treated operatively by excision of the comminuted avulsed fragment. After 33 months of follow-up radiographs showed no sign of degenerative joint disorder on simple X-ray, but slight Volar Intercalated Segment Instability (VISI) by a capitolunate angle of 26 degrees was noted. Clinically, the patient was pain free near full wrist and forearm range of motion and could perform his previous vocational and recreational tasks without any limitations. Conclusions Despite apparently good short and mid-term clinical outcome, slight volar intercalated segment instability after 33 months of follow-up revealed that lunotriquetral ligament function was probably lost, which led to static instability. This ligament injury may be missed primarily. Excision of the avulsed osteochondral fragment should be the last option of treatment and most attempts should be tried to fix and/or restore the normal anatomy of ligamentous structure. PMID:27626007

  2. Effects of management practices as risk factors for juvenile osteochondral conditions in 259 French yearlings.

    PubMed

    Praud, Anne; Dufour, Barbara; Robert, Céline; Valette, Jean-Paul; Denoix, Jean-Marie; Crevier-Denoix, Nathalie

    2013-07-01

    Several studies have demonstrated a statistical association between management practices and juvenile osteochondral conditions (JOCC) in foals from birth to 6months of age, but this association has not been investigated in yearlings. The purpose of the current study was to determine the adjusted effects of management practices on the onset and evolution of JOCC in French yearlings. The study sample consisted of 259 yearlings born on 20 stud farms in Normandy. The breeding conditions of these horses were monitored from 6 to 17months. They were radiographed at 6 and 17months to determine their radiographic score (RS) and its evolution. Potential risk factors were investigated using univariate and multivariate analyses. The prevalence of JOCC was 48% at 6months and 42% at 17months. Between 6 and 17months, the RS changed (for better or worse) in 52% of yearlings. The main risk factors leading to deterioration in the RS were traumatic. 'Mixed housing' during winter, pastures with rough ground and a bad RS at 6months were significantly associated with deterioration in RS between 6 and 17months. In the multivariate analysis, the breed was not significantly associated with any evolution in the yearlings' RS. This study provides some indications on protective measures to prevent the worsening of JOCC lesions between 6 and 17months, a crucial period since it precedes the sale of yearlings and the beginning of training.

  3. Tissue transfer techniques in reconstructive urology

    PubMed Central

    Bryk, Darren J; Yamaguchi, Yuka

    2015-01-01

    Tissue transfer techniques are an essential part of the reconstructive urologist's armamentarium. Flaps and graft techniques are widely used in genital and urethral reconstruction. A graft is tissue that is moved from a donor site to a recipient site without its native blood supply. The main types of grafts used in urology are full thickness grafts, split thickness skin grafts and buccal mucosa grafts. Flaps are transferred from the donor site to the recipient site on a pedicle containing its native blood supply. Flaps can be classified based on blood supply, elevation methods or the method of transfer. The most used flaps in urology include penile, preputial, and scrotal skin. We review the various techniques used in reconstructive urology and the outcomes of these techniques. PMID:26175866

  4. Suction blister skin grafting--a modern application.

    PubMed

    Parbhoo, A V; Simpson, M T

    2014-03-01

    The suction blistering technique produces an ultra-thin skin graft with no morbidity at the donor site. Negative pressure using wall suction in outpatients is used to generate a graft that can be used for reconstruction, and it avoids the need for invasive procedures in patients with coexisting conditions. The harvested tissue has a low metabolic demand and survival is excellent. We used it in a patient when previous reconstructions after excision of skin cancer had failed. Graft survival was more than 95% by surface area and there was no donor site morbidity. We have found it particularly useful for grafting over Integra® dermal regeneration template (Integra LifeSciences Corporation, NJ, USA) to produce healing at difficult sites. Patients tolerate the procedure well and the donor site heals quickly. It is useful where recipient vascularity is poor or where coexisting conditions prevent complex procedures.

  5. Composite vascular grafts with high cell infiltration by co-electrospinning.

    PubMed

    Tan, Zhikai; Wang, Hongjie; Gao, Xiangkai; Liu, Tong; Tan, Yongjun

    2016-10-01

    There is an increasing demand for functional small-diameter vascular grafts (diameter<6mm) to be used in clinical arterial replacement. An ideal vascular graft should have appropriate biomechanical properties and be biocompatible. Electrospinning has become a popular polymer processing technique for vascular tissue engineering, but the grafts fabricated by electrospinning often have relatively small pores and low porosity, which limit cell infiltration into scaffolds and hinder the regeneration and remodeling of grafts. In the present study, we aimed to develop an efficient method to prepare electrospun composite vascular grafts comprising natural and synthetic materials. We fabricated grafts made of polycaprolactone, gelatin, and polyvinyl alcohol (PVA) by co-electrospinning, and the scaffolds were further functionalized by immobilizing heparin on them. The PVA fibers degraded rapidly in vivo and generated electrospun scaffolds with high porosity, which significantly enhanced cell proliferation and infiltration. The mechanical properties of the grafts are suitable for use in artery replacement. Heparin functionalization of the grafts yielded a good antithrombogenic effect, which was demonstrated in platelet adhesion tests. Moreover, in vitro and in vivo results demonstrated that the heparin release from the grafts enhanced the growth of endothelial cells, which is important for the endothelium of implanted grafts. The results of this study indicate that our method is effective and controllable for the fabrication of vascular grafts that meet the clinical requirements for blood vessel transplantation. PMID:27287133

  6. Composite vascular grafts with high cell infiltration by co-electrospinning.

    PubMed

    Tan, Zhikai; Wang, Hongjie; Gao, Xiangkai; Liu, Tong; Tan, Yongjun

    2016-10-01

    There is an increasing demand for functional small-diameter vascular grafts (diameter<6mm) to be used in clinical arterial replacement. An ideal vascular graft should have appropriate biomechanical properties and be biocompatible. Electrospinning has become a popular polymer processing technique for vascular tissue engineering, but the grafts fabricated by electrospinning often have relatively small pores and low porosity, which limit cell infiltration into scaffolds and hinder the regeneration and remodeling of grafts. In the present study, we aimed to develop an efficient method to prepare electrospun composite vascular grafts comprising natural and synthetic materials. We fabricated grafts made of polycaprolactone, gelatin, and polyvinyl alcohol (PVA) by co-electrospinning, and the scaffolds were further functionalized by immobilizing heparin on them. The PVA fibers degraded rapidly in vivo and generated electrospun scaffolds with high porosity, which significantly enhanced cell proliferation and infiltration. The mechanical properties of the grafts are suitable for use in artery replacement. Heparin functionalization of the grafts yielded a good antithrombogenic effect, which was demonstrated in platelet adhesion tests. Moreover, in vitro and in vivo results demonstrated that the heparin release from the grafts enhanced the growth of endothelial cells, which is important for the endothelium of implanted grafts. The results of this study indicate that our method is effective and controllable for the fabrication of vascular grafts that meet the clinical requirements for blood vessel transplantation.

  7. Tooth-derived bone graft material

    PubMed Central

    Kim, Young-Kyun; Lee, Junho; Kim, Kyung-Wook; Murata, Masaru; Akazawa, Toshiyuki; Mitsugi, Masaharu

    2013-01-01

    With successful extraction of growth factors and bone morphogenic proteins (BMPs) from mammalian teeth, many researchers have supported development of a bone substitute using tooth-derived substances. Some studies have also expanded the potential use of teeth as a carrier for growth factors and stem cells. A broad overview of the published findings with regard to tooth-derived regenerative tissue engineering technique is outlined. Considering more than 100 published papers, our team has developed the protocols and techniques for processing of bone graft material using extracted teeth. Based on current studies and studies that will be needed in the future, we can anticipate development of scaffolds, homogenous and xenogenous tooth bone grafts, and dental restorative materials using extracted teeth. PMID:24471027

  8. Human turbinate mesenchymal stromal cell sheets with bellows graft for rapid tracheal epithelial regeneration.

    PubMed

    Park, Jeong Hun; Park, Ju Young; Nam, Inn-Chul; Hwang, Se-Hwan; Kim, Choung-Soo; Jung, Jin Woo; Jang, Jinah; Lee, Hyungseok; Choi, Yeongjin; Park, Sun Hwa; Kim, Sung Won; Cho, Dong-Woo

    2015-10-01

    Rapid functional epithelial regeneration on the luminal surface is essential when using artificial tracheal grafts to repair tracheal defects. In this study, we imposed human turbinate mesenchymal stromal cell (hTMSC) sheets for tracheal epithelial regeneration, and then assessed their potential as a new clinical cell source. In vitro, hTMSCs sheets showed high capacity to differentiate into tracheal epithelium. We fabricated a poly(ε-caprolactone) (PCL) tracheal graft by indirect three-dimensional (3D) printing technique and created a composite construct by transplanting the hTMSC sheets to its luminal surface of the tracheal graft, then applied this tissue-engineered tracheal graft to non-circumferential tracheal reconstruction in a rabbit model. 4 weeks after implantation, the luminal surface of tissue-engineered tracheal graft was covered by a mature and highly-ciliated epithelium, whereas tracheal grafts without hTMSC sheets were covered by only a thin, immature epithelium. Therefore, hTMSC sheets on the luminal surface of a tissue-engineered tracheal graft can accelerate the tracheal epithelial regeneration, and the tissue-engineered tracheal graft with hTMSC sheets provides a useful clinical alternative for tracheal epithelial regeneration.

  9. Scleral reinforcement in rabbits using synthetic graft materials.

    PubMed

    Whitmore, W G; Harrison, W; Curtin, B J

    1990-05-01

    Because of disappointing results using homologous collagen for scleral reinforcement in the treatment of pathologic myopia in humans, we undertook a series of experiments in rabbits to test the mechanical properties and long-term biocompatibility of three different synthetic graft materials. Grafts made from two of these materials, Gore-Tex Soft Tissue Patch (expanded polytetrafluoroethylene) and Miragel (poly[methyl acrylate-co-hydroxy-ethyl acrylate]), were easy to position about the globe. Both materials, however, were resistant to invasion by fibrovascular tissue. The third material, woven Dacron (polyethylene terephthalate), though more difficult to position, permitted extensive invasion of fibrovascular tissue, which made all parts of the graft firmly adherent to the globe. Our results indicate the long-term compatibility of all three of these materials when used as periscleral grafts in rabbits. However, our results also suggest that a woven material such as commercially available Dacron is a more suitable graft material for scleral reinforcement in humans than collagen, Miragel, or Gore-Tex.

  10. Sodium and chloride exclusion and retention by non-grafted and grafted melon and Cucurbita plants.

    PubMed

    Edelstein, M; Plaut, Z; Ben-Hur, M

    2011-01-01

    The effects of grafting on Na and Cl(-) uptake and distribution in plant tissues were quantified in a greenhouse experiment using six combinations of melon (Cucumis melo L. cv. Arava) and pumpkin (Cucurbita maxima Duchesne×Cucurbita moschata Duchesne cv. TZ-148): non-grafted, self-grafted, melons grafted on pumpkins, and pumpkins grafted on melons. Total Na concentration in shoots of plants with pumpkin or melon rootstocks was <60 mmol kg(-1) and >400 mmol kg(-1), respectively, regardless of the scion. In contrast, shoot Cl(-) concentrations were quite similar among the different scion-rootstock combinations. Na concentrations in exudates from cut stems of plants with a pumpkin rootstock were very low (<0.18 mM), whereas those in the exudates of plants with melon rootstocks ranged from 4.7 mM to 6.2 mM, and were quite similar to the Na concentration in the irrigation water. Root Na concentrations averaged 11.7 times those in the shoots of plants with pumpkin rootstocks, while in plants with melon rootstocks, values were similar. Two mechanisms could explain the decrease in shoot Na concentrations in plants with pumpkin rootstocks: (i) Na exclusion by the pumpkin roots; and (ii) Na retention and accumulation within the pumpkin rootstock. Quantitative analysis indicated that the pumpkin roots excluded ∼74% of available Na, while there was nearly no Na exclusion by melon roots. Na retention by the pumpkin rootstocks decreased its amount in the shoot by an average 46.9% compared with uniform Na distribution throughout the plant. In contrast, no retention of Na could be found in plants grafted on melons.

  11. The Articulated Alar Rim Graft: Reengineering the Conventional Alar Rim Graft for Improved Contour and Support.

    PubMed

    Ballin, Annelyse C; Kim, Haena; Chance, Elizabeth; Davis, Richard E

    2016-08-01

    Surgical refinement of the wide nasal tip is challenging. Achieving an attractive, slender, and functional tip complex without destabilizing the lower nasal sidewall or deforming the contracture-prone alar rim is a formidable task. Excisional refinement techniques that rely upon incremental weakening of wide lower lateral cartilages (LLC) often destabilize the tip complex and distort tip contour. Initial destabilization of the LLC is usually further exacerbated by "shrink-wrap" contracture, which often leads to progressive cephalic retraction of the alar margin. The result is a misshapen tip complex accentuated by a conspicuous and highly objectionable nostril deformity that is often very difficult to treat. The "articulated" alar rim graft (AARG) is a modification of the conventional rim graft that improves treatment of secondary alar rim deformities, including postsurgical alar retraction (PSAR). Unlike the conventional alar rim graft, the AARG is sutured to the underlying tip complex to provide direct stationary support to the alar margin, thereby enhancing graft efficacy. When used in conjunction with a well-designed septal extension graft (SEG) to stabilize the central tip complex, lateral crural tensioning (LCT) to tighten the lower nasal sidewalls and minimize soft-tissue laxity, and lysis of scar adhesions to unfurl the retracted and scarred nasal lining, the AARG can eliminate PSAR in a majority of patients. The AARG is also highly effective for prophylaxis against alar retraction and in the treatment of most other contour abnormalities involving the alar margin. Moreover, the AARG requires comparatively little graft material, and complications are rare. We present a retrospective series of 47 consecutive patients treated with the triad of AARG, SEG, and LCT for prophylaxis and/or treatment of alar rim deformities. Outcomes were favorable in nearly all patients, and no complications were observed. We conclude the AARG is a simple and effective method for

  12. Siloxane-grafted membranes

    DOEpatents

    Friesen, Dwayne T.; Obligin, Alan S.

    1989-01-01

    Composite cellulosic semipermeable membranes are disclosed which are the covalently bonded reaction product of an asymmetric cellulosic semipermeable membrane and a polysiloxane containing reactive functional groups. The two reactants chemically bond by ether, ester, amide or acrylate linkages to form a siloxane-grafted cellulosic membrane having superior selectivity and flux stability. Selectivity may be enhanced by wetting the surface with a swelling agent such as water.

  13. Siloxane-grafted membranes

    DOEpatents

    Friesen, D.T.; Obligin, A.S.

    1989-10-31

    Composite cellulosic semipermeable membranes are disclosed which are the covalently bonded reaction product of an asymmetric cellulosic semipermeable membrane and a polysiloxane containing reactive functional group. The two reactants chemically bond by ether, ester, amide or acrylate linkages to form a siloxane-grafted cellulosic membrane having superior selectivity and flux stability. Selectivity may be enhanced by wetting the surface with a swelling agent such as water.

  14. Closed-Wedge osteotomy for osteochondritis dissecans of the capitellum. A 7- to 12-year follow-up.

    PubMed

    Kiyoshige, Y; Takagi, M; Yuasa, K; Hamasaki, M

    2000-01-01

    This article details a 7- to 12-year follow-up of seven young male baseball players with osteochondritis dissecans of the capitellum that we treated using closed-wedge osteotomy. This procedure was established by Yoshizu in 1986 for the treatment of "Little League elbow." The bone of the capitellum was revascularized and remodeled within 6 months in all seven patients. Six of the patients were able to return to full athletic activity and continued to play baseball. Radiographic assessment during the follow-up study revealed minimal osteoarthritic change and suggests that the treatment is useful for such an injury.

  15. Anatomic Graft Passage in Remnant-Preserving Posterior Cruciate Ligament Reconstruction

    PubMed Central

    Ahn, Jin Hwan; Lee, Sang Hak

    2014-01-01

    Posterior cruciate ligament (PCL) reconstruction with preservation of the remnant PCL fibers has been performed under the assumption that preserving the fibers contributes to knee kinematics, grafted tendon healing, and recovery of proprioception. This technical note presents a single-bundle, transtibial PCL reconstruction with anatomic graft passage between the remnant PCL fibers. The operation is performed using the posterior trans-septal portal, which can provide excellent visualization while preserving a large amount of remnant PCL fibers. In addition, this technique allows for anatomic graft passage without soft-tissue impingement, and it minimizes the risk of nonanatomic positioning of the PCL grafts. PMID:25473610

  16. Perineurial differentiation in interchange grafts of rat peripheral nerve and spinal root.

    PubMed Central

    Radek, A; Thomas, P K; King, R H

    1986-01-01

    The differentiation of the perineurium has been examined in replacement nerve grafts in which segments of the third lumbar dorsal root and the peroneal division of the sciatic nerve of rats were excised and resutured into the gaps. This was compared with perineurial differentiation in interchange grafts in which segments of peroneal nerve were grafted into the third lumbar dorsal root and vice versa. It was concluded that not only the origin of the graft but also the local tissue environment is important in determining the morphological outcome, the latter having the predominant influence. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:3693073

  17. Development and assessment of a biodegradable solvent cast polyester fabric small-diameter vascular graft

    PubMed Central

    Brandes, Zachary R; Jonas, Richard A.; Fisher, John P.

    2014-01-01

    Adjusting the mechanical properties of polyester-based vascular grafts is crucial to achieving long-term success in vivo. While previous studies using a fabric-based approach have achieved some success, a central issue with pure poly(lactic acid) (PLA) or poly(glycolic acid) (PGA) grafts sealed with poly(DL-caprolactone-co-lactic acid) (P(CL/LA)) has been stenosis. Intimal hyperplasia, a leading cause of stenosis, can be caused by the mechanical incompatibility of synthetic vascular grafts. Investigating the performance of poly(glycolic-co-lactic acid) grafts (PGLA) could lead to insight into whether graft stenosis stems from mechanical issues such as non-compliance and unfavorable degradation times. This could be achieved by examining grafts with tunable mechanical properties between the ranges of such properties in pure PGA and PLA based grafts. In this study, we examined PGLA-based grafts sealed with different P(CL/LA) solutions to determine the PGLA-P(CL/LA) grafts' mechanical properties and tissue functionality. Cell attachment and proliferation on graft surfaces were also observed. For in vivo assessment, grafts were implanted in a mouse model. Mechanical properties and degradation times appeared adequate compared to recorded values of vessels used in autograft procedures. Initial neotissue formation was observed in the grafts and patency maintained during the pilot study. This study presents a ~1mm diameter degradable graft demonstrating suitable mechanical properties and in vivo pilot study success, enabling further investigation into the tuning of mechanical properties to reduce complications in degradable polyester fabric-based vascular grafts. PMID:23852776

  18. Development and assessment of a biodegradable solvent cast polyester fabric small-diameter vascular graft.

    PubMed

    Melchiorri, Anthony J; Hibino, Narutoshi; Brandes, Zachary R; Jonas, Richard A; Fisher, John P

    2014-06-01

    Adjusting the mechanical properties of polyester-based vascular grafts is crucial to achieving long-term success in vivo. Although previous studies using a fabric-based approach have achieved some success, a central issue with pure poly(lactic acid) (PLA) or poly(glycolic acid) (PGA) grafts sealed with poly(DL-caprolactone-co-lactic acid) (P(CL/LA)) has been stenosis. Intimal hyperplasia, a leading cause of stenosis, can be caused by the mechanical incompatibility of synthetic vascular grafts. Investigating the performance of poly(glycolic-co-lactic acid) (PGLA) grafts could lead to insight into whether graft stenosis stems from mechanical issues such as noncompliance and unfavorable degradation times. This could be achieved by examining grafts with tunable mechanical properties between the ranges of such properties in pure PGA and PLA-based grafts. In this study, we examined PGLA-based grafts sealed with different P(CL/LA) solutions to determine the PGLA-P(CL/LA) grafts' mechanical properties and tissue functionality. Cell attachment and proliferation on graft surfaces were also observed. For in vivo assessment, grafts were implanted in a mouse model. Mechanical properties and degradation times appeared adequate compared to recorded values of vessels used in autograft procedures. Initial neotissue formation was observed in the grafts and patency maintained during the pilot study. This study presents a ∼1-mm diameter degradable graft demonstrating suitable mechanical properties and in vivo pilot study success, enabling further investigation into the tuning of mechanical properties to reduce complications in degradable polyester fabric-based vascular grafts.

  19. Retrospective Cohort Study of 207 Cases of Osteochondritis Dissecans of the Knee

    PubMed Central

    Green, Daniel W.; Arbucci, John; Silberman, Jason; Luderowski, Eva; Uppstrom, Tyler J.; Nguyen, Joseph; Tuca, Maria

    2016-01-01

    Objectives: Describe the clinical characteristics, image findings, and outcomes of patients with juvenile osteochondritis dissecans (JOCD) of the knee. To our knowledge, this is the largest single-surgeon cohort of JOCD patients. Methods: Retrospective cohort study of knee JOCD patients assessed by a single pediatric orthopaedic surgeon at a tertiary care center between 2005-2015. All diagnoses were confirmed by magnetic resonance imaging (MRI). Patients with patellar dislocations or osteochondral fractures were excluded. Demographic data, sports played, comorbidities, surgical procedures, and clinical data were extracted from charts. Images were analyzed to identify the location and size of lesions. Chi-square or Fisher’s exact tests were used to compare discrete variables, and Mann-Whitney U and Kruskal Wallis tests to compare continuous variables between groups. P-values of <0.05 were considered significant. Results: Sample consisted of 180 patients (207 knees), 124 boys and 56 girls. Average age at diagnosis was 12.8 years (7.5-17.5). Majority were active in sports (80.8%), primary soccer (36.7%) and basketball (29.4%). JOCD was present bilaterally in 27 patients (15%), 14 knees had bifocal OCD (6.8%), and only 1 patient had bifocal lesions in both knees. Most common location was medial femoral condyle (56.3%) followed by lateral femoral condyle (23.1%), trochlea (11.4%), patella (9%), and tibia (0.5%). In the sagittal view, most common location was the middle third of the condyles (48.7%). Surgery was performed in 72 knees (34.8%), with an average age at surgery of 14.1 years (9.3-18.1). Bilateral JOCD was present in 13 surgical patients (18.8%), but only 3 patients had bilateral surgery. Two operative patients had bifocal JOCD (2.7%) and surgery on both lesions. Location distribution did not differ between surgical and non-surgical lesions. The average normalized area of non-surgical JOCD lesions was 6.8 (0.1-18), whereas surgical lesions averaged a

  20. Unique Anatomic Feature of the Posterior Cruciate Ligament in Knees Associated With Osteochondritis Dissecans

    PubMed Central

    Ishikawa, Masakazu; Adachi, Nobuo; Yoshikawa, Masahiro; Nakamae, Atsuo; Nakasa, Tomoyuki; Ikuta, Yasunari; Hayashi, Seiju; Deie, Masataka; Ochi, Mitsuo

    2016-01-01

    Background: Osteochondritis dissecans (OCD) of the knee is a disorder in juveniles and young adults; however, its etiology still remains unclear. For OCD at the medial femoral condyle (MFC), it is sometimes observed that the lesion has a connection with fibers of the posterior cruciate ligament (PCL). Although this could be important information related to the etiology of MFC OCD, there is no report examining an association between the MFC OCD and the PCL anatomy. Purpose: To investigate the anatomic features of knees associated with MFC OCD, focusing especially on the femoral attachment of the PCL, and to compare them with knees associated with lateral femoral condyle (LFC) OCD and non-OCD lesions. Study Design: Case-control study; Level of evidence, 3. Methods: We retrospectively reviewed 39 patients (46 knees) with OCD lesions who had undergone surgical treatment. Using magnetic resonance imaging (MRI) scans, the PCL attachment at the lateral wall of the MFC was measured on the coronal sections, and the knee flexion angle was also measured on the sagittal sections. As with non-OCD knees, we reviewed and analyzed 25 knees with anterior cruciate ligament (ACL) injuries and 16 knees with meniscal injuries. Results: MRIs revealed that the femoral PCL footprint was located in a significantly more distal position in the patients with MFC OCD compared with patients with LFC OCD and ACL and meniscal injuries. There was no significant difference in knee flexion angle among the 4 groups. Conclusion: The PCL in patients with MFC OCD attached more distally at the lateral aspect of the MFC compared with knees with LFC OCD and ACL and meniscal injuries. PMID:27294170

  1. Treatment of osteochondral lesions of the talus in athletes: what is the evidence?

    PubMed Central

    VANNINI, FRANCESCA; COSTA, GIUSEPPE GIANLUCA; CARAVELLI, SILVIO; PAGLIAZZI, GHERARDO; MOSCA, MASSIMILIANO

    2016-01-01

    Purpose ankle injuries make up 15% of all sports injuries and osteochondral lesions of the talus (OLTs) are an increasingly frequent problem in active patients. There exist no widely shared guidelines on OLT treatment in the athletic population. The aim of this paper is to review all the existing literature evidence on the surgical treatment of OLTs in athletes, in order to determine the current state of the art in this specific population, underlining both the limits and the potential of the strategies used. Methods a systematic review of the literature was performed focusing on the different types of surgical treatment used for OLTs in athletes. The screening process and analysis were performed separately by two independent researchers. The inclusion criteria for relevant articles were: clinical reports of any level of evidence, written in English, with no time limitation, or clinical reports describing the treatment of OLTs in the athletic population. Results with the consensus of the two observers, relevant data were then extracted and collected in a single database to be analyzed for the purposes of the present manuscript. At the end of the process, 16 papers met the selection criteria. These papers report a total of 642 athletic patients with OCTs. Conclusions the ideal treatment for cartilage lesions in athletes is a controversial topic, due to the need for an early return to sports, especially in elite players; this need leads to extensive use of microfractures in this population, despite the poor quality of repair associated with this technique. None of the surgical strategies described in this paper seems to be superior to the others. Level of evidence systematic review of level IV studies, level IV.

  2. Treatment of osteochondral lesions of the talus in athletes: what is the evidence?

    PubMed Central

    VANNINI, FRANCESCA; COSTA, GIUSEPPE GIANLUCA; CARAVELLI, SILVIO; PAGLIAZZI, GHERARDO; MOSCA, MASSIMILIANO

    2016-01-01

    Purpose ankle injuries make up 15% of all sports injuries and osteochondral lesions of the talus (OLTs) are an increasingly frequent problem in active patients. There exist no widely shared guidelines on OLT treatment in the athletic population. The aim of this paper is to review all the existing literature evidence on the surgical treatment of OLTs in athletes, in order to determine the current state of the art in this specific population, underlining both the limits and the potential of the strategies used. Methods a systematic review of the literature was performed focusing on the different types of surgical treatment used for OLTs in athletes. The screening process and analysis were performed separately by two independent researchers. The inclusion criteria for relevant articles were: clinical reports of any level of evidence, written in English, with no time limitation, or clinical reports describing the treatment of OLTs in the athletic population. Results with the consensus of the two observers, relevant data were then extracted and collected in a single database to be analyzed for the purposes of the present manuscript. At the end of the process, 16 papers met the selection criteria. These papers report a total of 642 athletic patients with OCTs. Conclusions the ideal treatment for cartilage lesions in athletes is a controversial topic, due to the need for an early return to sports, especially in elite players; this need leads to extensive use of microfractures in this population, despite the poor quality of repair associated with this technique. None of the surgical strategies described in this paper seems to be superior to the others. Level of evidence systematic review of level IV studies, level IV. PMID:27602351

  3. Does Graft on Flap Method Work on Sequela of Fingertip Amputation?

    PubMed

    Sano, Kazufumi; Ozeki, Satoru

    2016-10-01

    The graft on flap method, a useful option for the restoration of fresh fingertip amputation, was applied to the reconstruction of the short fingertip stumps resulting from the initial amputated stump plasties. As a modification, a nail bed graft from the big toe and a small cubic iliac bone graft were substituted for the lost tissues normally reduced as a composite graft in fresh cases. Upon follow-up ranging from 1 to 8 years, the grafted bone was found to have been resorpted in all cases. For the reconstruction of short fingertip stumps after the initial amputated stump plasties, acceptable results have not yet been achieved using the graft on flap method. PMID:27595968

  4. Coronary artery bypass graft: why is the saphenous vein prone to intimal hyperplasia?

    PubMed

    Sur, Swastika; Sugimoto, Jeffrey T; Agrawal, Devendra K

    2014-07-01

    Proliferation and migration of smooth muscle cells and the resultant intimal hyperplasia cause coronary artery bypass graft failure. Both internal mammary artery and saphenous vein are the most commonly used bypass conduits. Although an internal mammary artery graft is immune to restenosis, a saphenous vein graft is prone to develop restenosis. We found significantly higher activity of phosphatase and tensin homolog (PTEN) in the smooth muscle cells of the internal mammary artery than in the saphenous vein. In this article, we critically review the pathophysiology of vein-graft failure with detailed discussion of the involvement of various factors, including PTEN, matrix metalloproteinases, and tissue inhibitor of metalloproteinases, in uncontrolled proliferation and migration of smooth muscle cells towards the lumen, and invasion of the graft conduit. We identified potential target sites that could be useful in preventing and (or) reversing unwanted consequences following coronary artery bypass graft using saphenous vein. PMID:24933515

  5. Vein Graft-Coated Vascular Stents: A Feasibility Study in a Canine Model

    SciTech Connect

    Schellhammer, Frank; Haberstroh, Joerg; Wakhloo, Ajay K.; Gottschalk, Eva; Schumacher, Martin

    1998-03-15

    Purpose: To evaluate different vein grafts for luminal coating of endovascular stents in normal canine arteries. Methods: Twenty-four tantalum Strecker stents were coated with either autologous (n= 10), denatured heterologous (n= 11), or denatured homologous vein grafts (n= 3). The carotid artery (n= 11) and the iliac artery (n= 13) were stented using a transfemoral approach. Angiograms were performed at days 0, 7, and 21, and months 3, 6, and 9. All grafts underwent histological examination. Results: Eight of 10 autologous vein grafts showed patency during the whole observation period of 9 months, without histological signs of inflammation. Denatured heterologous vein grafts revealed acute (n= 3), subacute (n= 5), or delayed (n= 3) vessel occlusion. Hyaloid transformation of the vein graft and lympho-plasmacellular formations were seen. Denatured homologous vein grafts showed acute vessel occlusion. Although significant inflammatory tissue response was seen, no host-versus-graft reaction was present. Conclusion: Autologous vein graft-coated stents showed good biocompatibility in canine arteries. Preparation was cumbersome and required surgical venae-sectio. Denatured vein grafts, however, were limited by inflammatory reactions.

  6. Graft union formation in grapevine induces transcriptional changes related to cell wall modification, wounding, hormone signalling, and secondary metabolism

    PubMed Central

    Cookson, Sarah Jane; Clemente Moreno, Maria José; Hevin, Cyril; Nyamba Mendome, Larissa Zita; Delrot, Serge; Trossat-Magnin, Claudine; Ollat, Nathalie

    2013-01-01

    Grafting is particularly important to the cultivation of perennial crops such as grapevine (Vitis vinifera) because rootstocks can provide resistance to soil-borne pests and diseases as well as improve tolerance to some abiotic stresses. Successful grafting is a complex biochemical and structural process beginning with the adhesion of the two grafted partners, followed by callus formation and the establishment of a functional vascular system. At the molecular level, the sequence of events underlying graft union formation remains largely uncharacterized. The present study investigates the transcriptome of grapevine rootstock and graft interface tissues sampled 3 d and 28 d after grafting of over-wintering stems in the spring. Many genes were differentially expressed over time, from 3 d to 28 d after grafting, which could be related to the activation of stem growth and metabolic activity in the spring. This hypothesis is supported by the up-regulation of many genes associated with cell wall synthesis, and phloem and xylem development. Generally, there was an up-regulation of gene expression in the graft interface tissue compared with the rootstock, particularly genes involved in cell wall synthesis, secondary metabolism, and signalling. Although there was overlap between the genes differentially expressed over time (from 3 d to 28 d after grafting) with the gene differentially expressed between the rootstock and the graft interface, numerous graft interface-specific genes were identified. PMID:23698628

  7. Expression of colony-stimulating factor 1 is associated with occurrence of osteochondral change in pigmented villonodular synovitis.

    PubMed

    Ota, Takehiro; Urakawa, Hiroshi; Kozawa, Eiji; Ikuta, Kunihiro; Hamada, Shunsuke; Tsukushi, Satoshi; Shimoyama, Yoshie; Ishiguro, Naoki; Nishida, Yoshihiro

    2015-07-01

    Pigmented villonodular synovitis (PVNS) is a benign, translocation-derived neoplasm. Because of its high local recurrence rate after surgery and occurrence of osteochondral destruction, a novel therapeutic target is required. The present study aimed to evaluate the significance of protein expression possibly associated with the pathogenesis during the clinical course of PVNS. In 40 cases of PVNS, positivity of colony-stimulated factor 1 (CSF1), its receptor (CSF1R), and receptor activator of nuclear factor kappa-B ligand (RANKL) were immunohistochemically determined. The relationship between the positivity and clinical outcomes was investigated. High positivity of CSF1 staining intensity was associated with an increased incidence of osteochondral lesions (bone erosion and osteoarthritis) (p = 0.009), but not with the rate of local recurrence. Positivity of CSF1R and RANKL staining was not associated with any clinical variables. The number of giant cells was not correlated with positivity of any of the three proteins, or with the clinical outcome. Focusing on knee cases, CSF1 positivity was also associated with the incidence of osteochondal change (p = 0.02). CSF1R positivity was high in cases which had local recurrence, but not significantly so (p = 0.129). Determination of CSF1 and CSF1R expression may be useful as a prognosticator of the clinical course and/or outcomes of PVNS.

  8. Preparation and features of polycaprolactone vascular grafts with the incorporated vascular endothelial growth factor

    SciTech Connect

    Sevostyanova, V. V. Khodyrevskaya, Y. I.; Glushkova, T. V.; Antonova, L. V.; Kudryavtseva, Y. A.; Barbarash, O. L.; Barbarash, L. S.

    2015-10-27

    The development of tissue-engineered small-diameter vascular grafts is an urgent issue in cardiovascular surgery. In this study, we assessed how the incorporation of the vascular endothelial growth factor (VEGF) affects morphological and mechanical properties of polycaprolactone (PCL) vascular grafts along with its release kinetics. Vascular grafts were prepared using two-phase electrospinning. In pursuing our aims, we performed scanning electron microscopy, mechanical testing, and enzyme-linked immunosorbent assay. Our results demonstrated the preservation of a highly porous structure and improvement of PCL/VEGF scaffold mechanical properties as compared to PCL grafts. A prolonged VEGF release testifies the use of this construct as a scaffold for tissue-engineered vascular grafts.

  9. Preparation and features of polycaprolactone vascular grafts with the incorporated vascular endothelial growth factor

    NASA Astrophysics Data System (ADS)

    Sevostyanova, V. V.; Khodyrevskaya, Y. I.; Glushkova, T. V.; Antonova, L. V.; Kudryavtseva, Y. A.; Barbarash, O. L.; Barbarash, L. S.

    2015-10-01

    The development of tissue-engineered small-diameter vascular grafts is an urgent issue in cardiovascular surgery. In this study, we assessed how the incorporation of the vascular endothelial growth factor (VEGF) affects morphological and mechanical properties of polycaprolactone (PCL) vascular grafts along with its release kinetics. Vascular grafts were prepared using two-phase electrospinning. In pursuing our aims, we performed scanning electron microscopy, mechanical testing, and enzyme-linked immunosorbent assay. Our results demonstrated the preservation of a highly porous structure and improvement of PCL/VEGF scaffold mechanical properties as compared to PCL grafts. A prolonged VEGF release testifies the use of this construct as a scaffold for tissue-engineered vascular grafts.

  10. Antimicrobial Graft Copolymer Gels.

    PubMed

    Harvey, Amanda C; Madsen, Jeppe; Douglas, C W Ian; MacNeil, Sheila; Armes, Steven P

    2016-08-01

    In view of the growing worldwide rise in microbial resistance, there is considerable interest in designing new antimicrobial copolymers. The aim of the current study was to investigate the relationship between antimicrobial activity and copolymer composition/architecture to gain a better understanding of their mechanism of action. Specifically, the antibacterial activity of several copolymers based on 2-(methacryloyloxy)ethyl phosphorylcholine [MPC] and 2-hydroxypropyl methacrylate (HPMA) toward Staphylococcus aureus was examined. Both block and graft copolymers were synthesized using either atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization and characterized via (1)H NMR, gel permeation chromatography, rheology, and surface tensiometry. Antimicrobial activity was assessed using a range of well-known assays, including direct contact, live/dead staining, and the release of lactate dehydrogenase (LDH), while transmission electron microscopy was used to study the morphology of the bacteria before and after the addition of various copolymers. As expected, PMPC homopolymer was biocompatible but possessed no discernible antimicrobial activity. PMPC-based graft copolymers comprising PHPMA side chains (i.e. PMPC-g-PHPMA) significantly reduced both bacterial growth and viability. In contrast, a PMPC-PHPMA diblock copolymer comprising a PMPC stabilizer block and a hydrophobic core-forming PHPMA block did not exhibit any antimicrobial activity, although it did form a biocompatible worm gel. Surface tensiometry studies and LDH release assays suggest that the PMPC-g-PHPMA graft copolymer exhibits surfactant-like activity. Thus, the observed antimicrobial activity is likely to be the result of the weakly hydrophobic PHPMA chains penetrating (and hence rupturing) the bacterial membrane. PMID:27409712

  11. Immunocompetent cells requisite for graft rejection in Lineus (Invertebrata, Nemertea).

    PubMed

    Langlet, C; Bierne, J

    1984-01-01

    Antecerebral ends from donors of one Lineus species (L. sanguineus) were grafted onto bispecific recipients previously constructed from two other Lineus species (denoted L. ruber----L. lacteus because the anterior component of chimeras was from L. ruber and the posterior component was from L. lacteus) and onto monospecific controls. Histological examination of areas where the tissues from L. sanguineus and L. ruber had been brought into contact by grafting always showed, at early stages, (6 to 20 days postgrafting), a great deal of difference depending upon whether the recipients were monospecific L. ruber or bispecific L. ruber----L. lacteus: only in grafts onto the former was there lysis of gland cells, connective tissue, muscular fibers, and finally epidermis. We attribute this lytic process to a strongly and rapidly cytotoxic action of lymphocyte-like cells from the L. ruber intestinal segment and the absence of lysis during the same stage in grafts onto composite recipients and monospecific L. lacteus to weak, delayed actions of immunocytes from the L. lacteus intestinal segment. Subsequent phagocytosis of material from lysed cell of grafts in the process of being rejected was effected by wandering amebocytes usually involved in destruction of degenerating "self" components, as in oosorption and resorptive processes after fasting. This work supports the existence of immunocytes at an early phylogenetic level.

  12. Accelerating in Situ Endothelialisation of Cardiovascular Bypass Grafts

    PubMed Central

    Goh, Ee Teng; Wong, Eleanor; Farhatnia, Yasmin; Tan, Aaron; Seifalian, Alexander M.

    2014-01-01

    The patency of synthetic cardiovascular grafts in the long run is synonymous with their ability to inhibit the processes of intimal hyperplasia, thrombosis and calcification. In the human body, the endothelium of blood vessels exhibits characteristics that inhibit such processes. As such it is not surprising that research in tissue engineering is directed towards replicating the functionality of the natural endothelium in cardiovascular grafts. This can be done either by seeding the endothelium within the lumen of the grafts prior to implantation or by designing the graft such that in situ endothelialisation takes place after implantation. Due to certain difficulties identified with in vitro endothelialisation, in situ endothelialisation, which will be the focus of this article, has garnered interest in the last years. To promote in situ endothelialisation, the following aspects can be taken into account: (1) Endothelial progenital cell mobilization, adhesion and proliferation; (2) Regulating differentiation of progenitor cells to mature endothelium; (3) Preventing thrombogenesis and inflammation during endothelialisation. This article aims to review and compile recent developments to promote the in situ endothelialisation of cardiovascular grafts and subsequently improve their patency, which can also have widespread implications in the field of tissue engineering. PMID:25551605

  13. Autologous fat grafting: use of closed syringe microcannula system for enhanced autologous structural grafting

    PubMed Central

    Alexander, Robert W; Harrell, David B

    2013-01-01

    Objectives Provide background for use of acquiring autologous adipose tissue as a tissue graft and source of adult progenitor cells for use in cosmetic plastic surgery. Discuss the background and mechanisms of action of closed syringe vacuum lipoaspiration, with emphasis on accessing adipose-derived mesenchymal/stromal cells and the stromal vascular fraction (SVF) for use in aesthetic, structural reconstruction and regenerative applications. Explain a proven protocol for acquiring high-quality autologous fat grafts (AFG) with use of disposable, microcannula systems. Design Explain the components and advantage of use of the patented super luer-lock and microcannulas system for use with the closed-syringe system. A sequential explanation of equipment selection for minimally traumatic lipoaspiration in small volumes is presented, including use of blunt injection cannulas to reduce risk of embolism. Results Thousands of AFG have proven safe and efficacious for lipoaspiration techniques for large and small structural fat grafting procedures. The importance and advantages of gentle harvesting of the adipose tissue complex has become very clear in the past 5 years. The closed-syringe system offers a minimally invasive, gentle system with which to mobilize subdermal fat tissues in a suspension form. Resulting total nuclear counting of undifferentiated cells of the adipose-derived -SVF suggests that the yield achieved is better than use of always-on, constant mechanical pump applied vacuum systems. Conclusion Use of a closed-syringe lipoaspiration system featuring disposable microcannulas offers a safe and effective means of harvesting small volumes of nonmanipulated adipose tissues and its accompanying progenitor cells within the SVF. Closed syringes and microcannulas are available as safe, sterile, disposable, compact systems for acquiring high-quality AFG. Presented is a detailed, step-by-step, proven protocol for performing quality autologous structural adipose

  14. Listeria monocytogenes Endovascular Graft Infection

    PubMed Central

    Heysell, Scott K.; Hughes, Molly A.

    2016-01-01

    Although best managed by surgical resection, we present a case of Listeria monocytogenes endovascular graft infection alternatively treated with graft retention and antibiotic induction followed by a lifelong suppressive course. The epidemiological, pathological, and clinical features of this unique entity are reviewed. PMID:26835477

  15. Grafting effects on vegetable quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable grafting began in the 1920s to control soil-borne disease. It is now a common practice in Asia, parts of Europe, and the Middle East. In Japan and Korea most of the cucurbits and tomatoes (Lycopersicon esculentum Mill.) grown are grafted. This practice is rare in the U.S. and there have...

  16. Polyether/Polyester Graft Copolymers

    NASA Technical Reports Server (NTRS)

    Bell, Vernon L., Jr.; Wakelyn, N.; Stoakley, D. M.; Proctor, K. M.

    1986-01-01

    Higher solvent resistance achieved along with lower melting temperature. New technique provides method of preparing copolymers with polypivalolactone segments grafted onto poly (2,6-dimethyl-phenylene oxide) backbone. Process makes strong materials with improved solvent resistance and crystalline, thermally-reversible crosslinks. Resulting graft copolymers easier to fabricate into useful articles, including thin films, sheets, fibers, foams, laminates, and moldings.

  17. Skeletal tissue regeneration: where can hydrogels play a role?

    PubMed

    Moreira Teixeira, Liliana S; Patterson, Jennifer; Luyten, Frank P

    2014-09-01

    The emerging field of tissue engineering reveals promising approaches for the repair and regeneration of skeletal tissues including the articular cartilage, bone, and the entire joint. Amongst the myriad of biomaterials available to support this strategy, hydrogels are highly tissue mimicking substitutes and thus of great potential for the regeneration of functional tissues. This review comprises an overview of the novel and most promising hydrogels for articular cartilage, osteochondral and bone defect repair. Chondro- and osteo-conductive and -instructive hydrogels are presented, highlighting successful combinations with inductive signals and cell sources. Moreover, advantages, drawbacks, and future perspectives of the role of hydrogels in skeletal regeneration are addressed, pointing out the current state of this rising approach. PMID:24968789

  18. [Stent Grafting for Aortic Dissection].

    PubMed

    Uchida, Naomichi

    2016-07-01

    The purpose of stent graft for aortic dissection is to terminate antegrade blood flow into the false lumen through primary entry. Early intervention for primary entry makes excellent aortic remodeling and emergent stent grafting for complicated acute type B aortic dissection is supported as a class I. On the other hand stent grafting for chronic aortic dissection is controversial. Early stent grafting is considered with in 6 months after on-set if the diameter of the descending aorta is more than 40 mm. Additional interventions for residual false lumen on the downstream aorta are still required. Stent graft for re-entry, candy-plug technique, and double stenting, other effective re-interventions were reported. Best treatment on the basis of each anatomical and physical characteristics should be selected in each institution. Frozen elephant trunk is alternative procedure for aortic dissection without the need to take account of proximal anatomical limitation and effective for acute type A aortic dissection. PMID:27440026

  19. Radiation grafting on natural films

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

    2014-01-01

    Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37-40 N mm-1) and puncture deformation (PD=6.5-9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282-296 N mm-1 and PD of 5.0-5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films.

  20. Fractional CO2 laser treatment for a skin graft.

    PubMed

    Stephan, Farid E; Habre, Maya B; Helou, Josiane F; Tohme, Roland G; Tomb, Roland R

    2016-01-01

    Skin grafts are widely used in reconstructive and plastic surgery, leaving an inevitable scar appearance on the body, affecting the quality of life of the patients. Fractional ablative lasers have become a leading procedure for the treatment of acne and burn scars. We report a case of a skin graft showing excellent improvement in overall appearance after three sessions of fractional CO2 laser. The undamaged tissue left between the microthermal treatment zones is responsible of collagen formation and reepithelialization. Remodeling and collagen formation are observed even 6 months after a fractional CO2 laser session. PMID:26052811

  1. Bioactive glass in tissue engineering

    PubMed Central

    Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

    2011-01-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  2. Bioactive glass in tissue engineering.

    PubMed

    Rahaman, Mohamed N; Day, Delbert E; Bal, B Sonny; Fu, Qiang; Jung, Steven B; Bonewald, Lynda F; Tomsia, Antoni P

    2011-06-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed.

  3. Fitting of the dermis-fat grafted socket.

    PubMed

    Przybyla, V A; La Piana, F G; Bergin, D J

    1981-09-01

    Ano