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Sample records for dermal collagen implant

  1. Electrospun synthetic human elastin:collagen composite scaffolds for dermal tissue engineering.

    PubMed

    Rnjak-Kovacina, Jelena; Wise, Steven G; Li, Zhe; Maitz, Peter K M; Young, Cara J; Wang, Yiwei; Weiss, Anthony S

    2012-10-01

    We present an electrospun synthetic human elastin:collagen composite scaffold aimed at dermal tissue engineering. The panel of electrospun human tropoelastin and ovine type I collagen blends comprised 80% tropoelastin+20% collagen, 60% tropoelastin+40% collagen and 50% tropoelastin+50% collagen. Electrospinning efficiency decreased with increasing collagen content under the conditions used. Physical and mechanical characterization encompassed fiber morphology, porosity, pore size and modulus, which were prioritized to identify the optimal candidate for dermal tissue regeneration. Scaffolds containing 80% tropoelastin and 20% collagen (80T20C) were selected on this basis for further cell interaction and animal implantation studies. 80T20C enhanced proliferation and migration rates of dermal fibroblasts in vitro and were well tolerated in a mouse subcutaneous implantation study where they persisted over 6 weeks. The 80T20C scaffolds supported fibroblast infiltration, de novo collagen deposition and new capillary formation.

  2. Multilayered implantation using acellular dermal matrix into nude mice.

    PubMed

    Lee, Dong Won; Lee, Myung Chul; Roh, Hyun; Lee, Won Jai

    2014-12-01

    Soft tissue augmentation using acellular dermal matrix has gained popularity to overcome the shortcomings of autogenous and alloplastic materials. Sometimes it needs multilayered stacking to obtain enough volume. In this study, we investigated the efficacy of multilayered implantation using acellular dermal matrix (MatriDerm(®)) for soft tissue augmentation. MatriDerm was implanted subdermally on each side of the dorsum of nude mice (n = 20), stacked two layers thick in the control group and three layers thick in the experimental group. Alterations of thickness, degree of angiogenesis, and collagen and elastin fiber syntheses were observed over 40 days. Three-layered implantation with MatriDerm maintained its volume similarly as in two-layered implantation, although the thickness decreased after 30 days in both groups. At the early stage of implantation, angiogenesis and collagen and elastin fiber syntheses occurred fluently on the central portion, which is the farthest away from the surface in contact with the host tissue. Collagen and elastin fibers became more concentrated over time, and the original structure of MatriDerm could not be maintained due to being replaced with newly formed collagen and elastin fibers 40 days after implantation. Multilayered implantation with MatriDerm is considered appropriate for tissue ingrowth and can be used as a substitute for soft tissue augmentation.

  3. Type VI Collagen Regulates Dermal Matrix Assembly and Fibroblast Motility.

    PubMed

    Theocharidis, Georgios; Drymoussi, Zoe; Kao, Alexander P; Barber, Asa H; Lee, David A; Braun, Kristin M; Connelly, John T

    2016-01-01

    Type VI collagen is a nonfibrillar collagen expressed in many connective tissues and implicated in extracellular matrix (ECM) organization. We hypothesized that type VI collagen regulates matrix assembly and cell function within the dermis of the skin. In the present study we examined the expression pattern of type VI collagen in normal and wounded skin and investigated its specific function in new matrix deposition by human dermal fibroblasts. Type VI collagen was expressed throughout the dermis of intact human skin, at the expanding margins of human keloid samples, and in the granulation tissue of newly deposited ECM in a mouse model of wound healing. Generation of cell-derived matrices (CDMs) by human dermal fibroblasts with stable knockdown of COL6A1 revealed that type VI collagen-deficient matrices were significantly thinner and contained more aligned, thicker, and widely spaced fibers than CDMs produced by normal fibroblasts. In addition, there was significantly less total collagen and sulfated proteoglycans present in the type VI collagen-depleted matrices. Normal fibroblasts cultured on de-cellularized CDMs lacking type VI collagen displayed increased cell spreading, migration speed, and persistence. Taken together, these findings indicate that type VI collagen is a key regulator of dermal matrix assembly, composition, and fibroblast behavior and may play an important role in wound healing and tissue regeneration. PMID:26763426

  4. Polarized Microscopy in Lesions With Altered Dermal Collagen.

    PubMed

    Elbendary, Amira; Valdebran, Manuel; Parikh, Kruti; Elston, Dirk M

    2016-08-01

    Alterations in dermal collagen are noted in dermatofibroma, dermatofibrosarcoma protuberans, morphea, lichen sclerosus et atrophicus, hypertrophic scars, and keloids. The authors sought to determine whether variations in birefringence of collagen by polarized microscopy could be of help in diagnosing such conditions. Representative hematoxylin and eosin sections of 400 cases, including dermatofibroma, dermatofibrosarcoma protuberans, hypertrophic scars, keloid, morphea, and lichen sclerosus, were examined under polarized microscopy. Distinct patterns of birefringence of collagen for each disease were noted under polarized microscopy. This study highlights the use of polarized microscopy as adjunctive tool in differentiating different diseases with collagen alteration. PMID:26959692

  5. Temporal variation in the deposition of different types of collagen within a porous biomaterial implant.

    PubMed

    White, Jacinta F; Werkmeister, Jerome A; Bisucci, Teresa; Darby, Ian A; Ramshaw, John A M

    2014-10-01

    The deposition of new collagen in association with a medical implant has been studied using expanded polytetrafluoroethylene vascular replacement samples implanted subcutaneously in sheep, for up to 28 days. New type I collagen mRNA synthesis was followed by in situ hybridization, while the accumulation of new collagen types III, V, VI, XII, and XIV was followed by immunohistochemistry. All the collagen detected in the pores of the implant were newly deposited at various times after implantation and were not due to any pre-existing dermal collagen that may have been present around the implant. Collagen deposition was seen initially surrounding the implant and, with time, was seen to infiltrate within its pores. In situ hybridization showed that the majority of infiltrating cells had switched on mRNA that coded for type I collagen production. Histology showed that cellular infiltration increased with time, accompanied by increasing collagen deposition. The deposition of different collagen types happened at different rates. The type V and VI collagens preceded the major interstitial collagens in the newly deposited tissue, although at longer time points, detection of type V collagen appeared to decrease. After disruption of the interstitial collagens with enzyme, the "masked" type V collagen was clearly still visible by immunohistochemistry. Little type XII collagen could be seen within the porous mesh, although it was seen in the surrounding tissues. By contrast, type XIV was seen throughout the porous structure of the implanted mesh, with less being visible outside the material where type XII was more abundant.

  6. Collagen-based dermal fillers: past, present, future.

    PubMed

    Cockerham, Kimberly; Hsu, Victoria J

    2009-05-01

    The demand for dermal fillers and the variety of dermal fillers available have evolved dramatically during the past 2 decades. Collagen was the first material to be approved by the U.S. Food and Drug Administration (FDA) for injection into facial scars, furrows, and lines. Bovine collagen (95% type I and 5% type III collagen) was approved in 1981; buffered collagen Zyderm I and Zyderm II followed by Zyplast were FDA approved and released shortly thereafter. This article will focus on the historical benefits and risks of collagen injections and the typical outcomes. With the advent of hyaluronic acid products and other options, the risks of collagen and limited benefit have caused a marked loss of market share. Specifically, allergy is a major concern. As a result, two rounds of skin testing are required adding inconvenience and delay for both the practitioner and patient. Furthermore, a negative skin test does not guarantee allergic reactions or other more serious side effects will not occur. Finally, the perceived clinical efficacy is often short lived despite histopathologic assessments showing that collagen persists at best 9 months.

  7. Localized controlled release of stratifin reduces implantation-induced dermal fibrosis.

    PubMed

    Rahmani-Neishaboor, Elham; Hartwell, Ryan; Jalili, Reza; Jackson, John; Brown, Erin; Ghahary, Aziz

    2012-10-01

    Localized controlled release of anti-fibrogenic factors can potentially prevent tissue fibrosis surrounding biomedical prostheses, such as vascular stents and breast implants. We have previously demonstrated that therapeutic intervention with topically applied stratifin in a rabbit ear fibrotic model not only prevents dermal fibrosis but also promotes more normal tissue repair by regulating extracellular matrix deposition. In this work, the anti-fibrogenic effect of a controlled release form of stratifin was investigated in the prevention of fibrosis induced by dermal poly(lactic-co-glycolic acid) (PLGA) microsphere/poly(vinyl alcohol) (PVA) hydrogel implants. Pharmacodynamic effects were evaluated by histopathological examination of subcutaneous tissue surrounding implanted composites. Controlled release of stratifin from PLGA microsphere/PVA hydrogel implants significantly moderated dermal fibrosis and inflammation by reducing collagen deposition (30%), total tissue cellularity (48%) and infiltrated CD3(+) immune cells (81%) in the surrounding tissue compared with the stratifin-free implants. The controlled release of stratifin from implants markedly increased the level of matrix metalloproteinase-1 expression in the surrounding tissue, which resulted in less collagen deposition. These stratifin-eluting PLGA/PVA composites show promise as coatings to decrease the typical fibrosis exhibited around implanted biomedical prostheses, such as breast implants and vascular stents. PMID:22743110

  8. Injectable collagen implant--update.

    PubMed

    Castrow, F F; Krull, E A

    1983-12-01

    Injectable collagen implant (ICI), a new biomaterial reportedly useful for correction of scars and certain aging skin lines (wrinkles), was recently introduced. The purpose of this paper is to evaluate the safety and efficacy of this product. Data for this study were obtained from a survey which was sent to a group of cutaneous surgeons. They were asked about test site and treatment site reactions and about their satisfaction with ICI. The incidence of adverse reactions is low, and the severity of the reactions does not appear to be serious. The long-term benefit of ICI has not been established.

  9. Estrogen Depletion Results in Nanoscale Morphology Changes in Dermal Collagen

    PubMed Central

    Fang, Ming; Liroff, Kaitlin G.; Turner, A. Simon; Les, Clifford M.; Orr, Bradford G.; Holl, Mark M. Banaszak

    2012-01-01

    Tissue cryo-sectioning combined with Atomic Force Microscopy (AFM) imaging reveals that the nanoscale morphology of dermis collagen fibrils, quantified using the metric of D-periodic spacing, changes under the condition of estrogen depletion. Specifically, a new subpopulation of fibrils with D-spacings in the region between 56 and 59 nm is present two years following ovariectomy in ovine dermal samples. In addition, the overall width of the distribution, both values above and below the mean, has increased. The change in width due to an increase in lower values of D-spacings was previously reported for ovine bone; however, this report demonstrates that the effect is also present in non-mineralized collagen fibrils. A non-parametric Kolmogrov-Smirnov test of the cumulative density function indicates a statistical difference in the sham and OVX D-spacing distributions (p < 0.01). PMID:22437310

  10. Cytotoxic evaluation of biomechanically improved crosslinked ovine collagen on human dermal fibroblasts.

    PubMed

    Awang, M A; Firdaus, M A B; Busra, M B; Chowdhury, S R; Fadilah, N R; Wan Hamirul, W K; Reusmaazran, M Y; Aminuddin, M Y; Ruszymah, B H I

    2014-01-01

    Earlier studies in our laboratory demonstrated that collagen extracted from ovine tendon is biocompatible towards human dermal fibroblast. To be able to use this collagen as a scaffold in skin tissue engineering, a mechanically stronger scaffold is required that can withstand manipulation before transplantation. This study was conducted to improve the mechanical strength of this collagen sponge using chemical crosslinkers, and evaluate their effect on physical, chemical and biocompatible properties. Collagen sponge was crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and glutaraldehyde (GA). Tensile test, FTIR study and mercury porosimetry were used to evaluate mechanical properties, chemical property and porosity, respectively. MTT assay was performed to evaluate the cytotoxic effect of crosslinked collagen sponge on human dermal fibroblasts. The FTIR study confirmed the successful crosslinking of collagen sponge. Crosslinking with EDC and GA significantly increased the mechanical strength of collagen sponge, with GA being more superior. Crosslinking of collagen sponge significantly reduced the porosity and the effect was predominant in GA-crosslinked collagen sponge. The GA-crosslinked collagen showed significantly lower, 60% cell viability towards human dermal fibroblasts compared to that of EDC-crosslinked collagen, 80% and non-crosslinked collagen, 100%. Although the mechanical strength was better when using GA but the more toxic effect on dermal fibroblast makes EDC a more suitable crosslinker for future skin tissue engineering.

  11. Temporary granulomatous inflammation following collagen implantation.

    PubMed

    Heise, H; Zimmermann, R; Heise, P

    2001-08-01

    Injections of bovine collagen are a common procedure for correction of folds in the face. However, this therapy is not free from side effects. We present a patient in whom a granulomatous inflammation occurred following implantation of this material. We therefore now insist on an observation interval of 4 weeks between test injection and actual treatment, as is recommended by the manufacturer.

  12. Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts.

    PubMed

    Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo; Kim, So Young; Jang, Hwan-Hee; Ryu, Sung Ho; Kim, Beom Joon; Lee, Taehoon G

    2012-11-23

    The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin, respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929-933 sequence of the β1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong candidate peptide for the treatment of skin aging and wrinkles.

  13. Correction of tear trough deformity with novel porcine collagen dermal filler (Dermicol-P35).

    PubMed

    Goldberg, David J

    2009-01-01

    Deformity of the tear trough region, which can occur during the aging process, can result in dark shadows under the eyes and a fatigued appearance. Augmentation of the tear trough is challenging because of the thin skin and lack of fat in the region. Adding volume to the tear trough region with a dermal filler is a nonsurgical procedure with minimal discomfort to the patient. Dermicol-P35 (Evolence; Ortho Dermatologics, Skillman, NJ) is a new, ribose crosslinked, highly purified, porcine-based collagen filler that does not require prior skin testing and has shown improved persistence compared with bovine collagen-based dermal fillers. In this article, we present the clinical outcomes of patients who have received treatment with a novel ribose crosslinked porcine collagen dermal filler for the correction of tear trough deformity.

  14. In vivo visualization of dermal collagen fiber in skin burn by collagen-sensitive second-harmonic-generation microscopy

    NASA Astrophysics Data System (ADS)

    Tanaka, Ryosuke; Fukushima, Shu-ichiro; Sasaki, Kunihiko; Tanaka, Yuji; Murota, Hiroyuki; Matsumoto, Takeshi; Araki, Tsutomu; Yasui, Takeshi

    2013-06-01

    Optical assessment of skin burns is possible with second-harmonic-generation (SHG) microscopy due to its high sensitivity to thermal denaturation of collagen molecules. In contrast to previous studies that were performed using excised tissue specimens ex vivo, in vivo observation of dermal collagen fibers in living rat burn models with SHG microscopy is demonstrated. Changes in signal vanishing patterns in the SHG images are confirmed to be dependent on the burn degree. Comparison of the SHG images with Masson's trichrome-stained images indicated that the observed patterns were caused by the coexistence of molten and fibrous structures of dermal collagen fibers. Furthermore, a quantitative parameter for burn assessment based on the depth profile of the mean SHG intensity across the entire SHG image is proposed. These results and discussions imply a potential of SHG microscopy as a minimally invasive, highly quantitative tool for skin burn assessment.

  15. Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts

    SciTech Connect

    Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo; Kim, So Young; Jang, Hwan-Hee; Ryu, Sung Ho; Kim, Beom Joon; Lee, Taehoon G.

    2012-11-23

    Highlights: Black-Right-Pointing-Pointer We identify a function of the YIGSR peptide to enhance collagen synthesis in Hs27. Black-Right-Pointing-Pointer YIGSR peptide enhanced collagen type 1 synthesis both of gene and protein levels. Black-Right-Pointing-Pointer There were no changes in cell proliferation and MMP-1 level in YIGSR treatment. Black-Right-Pointing-Pointer The YIGSR effect on collagen synthesis mediated activation of FAK, pyk2 and ERK. Black-Right-Pointing-Pointer The YIGSR-induced FAK and ERK activation was modulated by FAK and MEK inhibitors. -- Abstract: The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin, respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929-933 sequence of the {beta}1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67 kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong candidate

  16. Repeat mild heat shock increases dermal fibroblast activity and collagen production.

    PubMed

    Mayes, Andrew E; Holyoak, Caroline D

    2008-04-01

    Repeat mild heat shock (RMHS) has been shown to have anti-aging effects on cellular and biological processes within human dermal fibroblasts. We have investigated the potential of an abridged mild heat shock regime to impact upon the functional properties of human dermal fibroblasts derived from three donors (male, 12 years; female, 22 years; female, 65 years). For each donor mild heat shock increased the rate of contraction of fibroblast-containing collagen gels and increased the de novo synthesis of collagen. Thus, hormetic mechanisms are proposed to provide functional anti-aging benefits to skin cells.

  17. [Granulomatous reactions from aesthetic dermal micro-implants].

    PubMed

    Rongioletti, F

    2008-01-01

    Granulomatous reactions to dermal fillers for tissue augmentation is a rare but possible late complication occurring both with permanent (more frequent) and biodegradable or resorbable products. Predictions cannot be made for possible late reactions, sometimes occurring even after 18 years. Although clinical diagnosis seems to be an easy task, the issue is sometimes challenging if cosmetic intervention is denied or not mentioned by the patient or by the referring physician. Identifying the filler is therefore difficult and experts may be called in trials to solve the problem. Histopathology is the best means to obtain the correct diagnosis and to identify the type of filler particles. In fact, the particular configuration of the vacuoles and cystic structures inside the granulomas reflects the shape of the injected implants particles. The clinical and microscopic features, the pathogenesis and the treatment of the granulomatous reactions to dermal fillers for tissue augmentation will be presented and discussed.

  18. In vivo imaging of dermal collagen in skin burn by collagen-sensitive second-harmonic-generation microscopy

    NASA Astrophysics Data System (ADS)

    Yasui, Takeshi; Tanaka, Ryosuke; Hase, Eiji; Fukushima, Shu-ichiro; Araki, Tsutomu

    2013-02-01

    Optical assessment of skin burns is possible with second-harmonic-generation (SHG) microscopy due to its high sensitivity to thermal denaturation of collagen molecules. In contrast to previous studies that were performed using excised tissue specimens ex vivo, in this study, we demonstrated in vivo observation of dermal collagen fibers in living rat burn models with SHG microscopy. We confirmed that changes in SHG vanishing patterns in the SHG images depended on the burn degree. The results imply that SHG microscopy can be used as a low-invasiveness, highly quantitative tool for skin burn assessment.

  19. Prostaglandin E2 inhibits collagen synthesis in dermal fibroblasts and prevents hypertrophic scar formation in vivo.

    PubMed

    Zhao, Jingling; Shu, Bin; Chen, Lei; Tang, Jinming; Zhang, Lijun; Xie, Julin; Liu, Xusheng; Xu, Yingbin; Qi, Shaohai

    2016-08-01

    Hypertrophic scarring is a common dermal fibroproliferative disorder characterized by excessive collagen deposition. Prostaglandin E2 (PGE2 ), an important inflammatory product synthesized via the arachidonic acid cascade, has been shown to act as a fibroblast modulator and to possess antifibroblastic activity. However, the mechanism underlying the antifibrotic effect of PGE2 remains unclear. In this study, we explored the effects of PGE2 on TGF-β1-treated dermal fibroblasts in terms of collagen production and to determine the regulatory pathways involved, as well as understand the antiscarring function of PGE2 in vivo. We found that PGE2 inhibited TGF-β1-induced collagen synthesis by regulating the balance of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP). It did so by upregulating cAMP through the E prostanoid (EP)2 receptor. We determined that inhibition of the TGF-β1/Smad pathway by PGE2 is associated with its ability to inhibit collagen synthesis. An in vivo study further confirmed that PGE2 inhibits hypertrophic scar formation by decreasing collagen production. Our results demonstrate that the novel anti-scarring function of PGE2 is achieved by balancing MMPs/TIMP expression and decreasing collagen production. PMID:26997546

  20. Collagen-functionalised titanium surfaces for biological sealing of dental implants: effect of immobilisation process on fibroblasts response.

    PubMed

    Marín-Pareja, Nathalia; Salvagni, Emiliano; Guillem-Marti, Jordi; Aparicio, Conrado; Ginebra, Maria-Pau

    2014-10-01

    The clinical success of a dental implant requires not only an optimum osseointegration, but also the development of a biological sealing; i.e., a soft tissue seal around the transmucosal part of the implant. A promising approach to improve the biological seal of dental implants is the biomimetic modification of titanium surfaces with proteins or peptides that have specific cell-binding moieties. In this work we investigated the process of immobilising collagen on smooth and rough titanium surfaces and its effect on human dermal fibroblast (HDF) cell response. Titanium samples were activated by either oxygen plasma or acid etching to generate a smooth or nanorough surface, respectively. Subsequently, collagen grafting was achieved by either physisorption or covalent bonding through organosilane chemistry. The biofunctionalised titanium samples were then tested for stability and characterised by fluorescent labelling, wettability, OWLS and XPS studies. Biological characterisation was also performed through HDF adhesion, proliferation and gene expression. Covalent-bonded collagen showed higher stability than physisorbed collagen. A significant overexpression of the genes involved in fibroblast activation and extracellular matrix remodelling was observed in the collagen-coated surfaces. This effect was more pronounced on smooth than on rough surfaces. Immobilised collagen on the smooth plasma-treated surfaces favoured both fibroblast adhesion and activation. This study provides essential information for the design of implants with optimal biological sealing, a key aspect to avoid peri-implantitis and ensure long-lasting implant fixation.

  1. Development of biomimetic tilapia collagen nanofibers for skin regeneration through inducing keratinocytes differentiation and collagen synthesis of dermal fibroblasts.

    PubMed

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2015-02-11

    In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides, and its denaturation temperature was 44.99 °C. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4+/CD8+ lymphocytes, and the level of IgG or IgM in Sprague-Dawley rat. The contact angle, tensile strength, and weight loss temperature of collagen nanofibers were 21.2°, 6.72±0.44 MPa, and 300 °C, respectively. The nanofibers could promote the viabilities of human keratinocytes (HaCaTs) and human dermal fibroblasts (HDFs), inducing epidermal differentiation through the gene expression of involucrin, filaggrin, and type I transglutaminase of HaCaTs, and they could also accelerate migration of HaCaTs with the expression of matrix metalloproteinase-9 and transforming growth factor-β1 (TGF-β1). Besides, the nanofibers could upregulate the protien level of Col-I in HDFs both via a direct effect and TGF-β1 secreted from HaCaTs, thus facilitating the formation of collagen fibers. Furthermore, the collagen nanofibers stimulated the skin regeneration rapidly and effectively in vivo. These biological effects could be explained as the contributions from the biomimic extracellular cell matrix structure, hydrophilicity, and the multiple amino acids of the collagen nanofibers. PMID:25598076

  2. Development of biomimetic tilapia collagen nanofibers for skin regeneration through inducing keratinocytes differentiation and collagen synthesis of dermal fibroblasts.

    PubMed

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2015-02-11

    In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides, and its denaturation temperature was 44.99 °C. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4+/CD8+ lymphocytes, and the level of IgG or IgM in Sprague-Dawley rat. The contact angle, tensile strength, and weight loss temperature of collagen nanofibers were 21.2°, 6.72±0.44 MPa, and 300 °C, respectively. The nanofibers could promote the viabilities of human keratinocytes (HaCaTs) and human dermal fibroblasts (HDFs), inducing epidermal differentiation through the gene expression of involucrin, filaggrin, and type I transglutaminase of HaCaTs, and they could also accelerate migration of HaCaTs with the expression of matrix metalloproteinase-9 and transforming growth factor-β1 (TGF-β1). Besides, the nanofibers could upregulate the protien level of Col-I in HDFs both via a direct effect and TGF-β1 secreted from HaCaTs, thus facilitating the formation of collagen fibers. Furthermore, the collagen nanofibers stimulated the skin regeneration rapidly and effectively in vivo. These biological effects could be explained as the contributions from the biomimic extracellular cell matrix structure, hydrophilicity, and the multiple amino acids of the collagen nanofibers.

  3. Biotinylated GHK peptide incorporated collagenous matrix: A novel biomaterial for dermal wound healing in rats.

    PubMed

    Arul, V; Gopinath, D; Gomathi, K; Jayakumar, R

    2005-05-01

    Matrikines are small peptide fragments of extracellular matrix proteins that display potent tissue repair activities. Difficulties in achieving sustained delivery of bioactive concentration of matrikines in the affected area limits their therapeutic use. The present study evaluates the effects biotinylated matrikine peptide (bio-glycyl-histidyl-lysine) incorporated collagen membrane for dermal wound healing processes in rats. Biotinylated peptide incorporated collagen matrix (PIC) showed better healing when compared to wounds treated with collagen matrix [CF (collagen film)] and without collagen [CR (control)]. Binding studies indicate that biotinylated GHK (Bio-GHK) binds effectively to the collagen matrix and red blood cell (RBC) membrane when compared with t-butyloxycarbonyl substituted GHK (Boc-GHK). Wound contraction, increased cell proliferation, and high expression of antioxidant enzymes in PIC treated group indicate enhanced wound healing activity when compared to CF and CR groups. Interestingly Bio-GHK incorporated collagen increases the copper concentration by ninefold at the wound site indicating the wound healing property of Bio-GHK can also be linked with both copper localization and matrikine activities. These results demonstrate the possibility of using Bio-GHK incorporated collagen film as a therapeutic agent in the wound healing process. PMID:15803494

  4. Effects of Panax ginseng extract on human dermal fibroblast proliferation and collagen synthesis.

    PubMed

    Lee, Geum-Young; Park, Kang-Gyun; Namgoong, Sik; Han, Seung-Kyu; Jeong, Seong-Ho; Dhong, Eun-Sang; Kim, Woo-Kyung

    2016-03-01

    Current studies of Panax ginseng (or Korean ginseng) have demonstrated that it has various biological effects, including angiogenesis, immunostimulation, antimicrobial and anti-inflammatory effects. Therefore, we hypothesised that P. ginseng may also play an important role in wound healing. However, few studies have been conducted on the wound-healing effects of P. ginseng. Thus, the purpose of this in vitro pilot study was to determine the effects of P. ginseng on the activities of fibroblasts, which are key wound-healing cells. Cultured human dermal fibroblasts were treated with one of six concentrations of P. ginseng: 0, 1, 10 and 100 ng/ml and 1 and 10 µg/ml. Cell proliferation was determined 3 days post-treatment using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay, and collagen synthesis was evaluated by the collagen type I carboxy-terminal propeptide method. Cell proliferation levels and collagen synthesis were compared among the groups. The 10 ng/ml to 1 µg/ml P. ginseng treatments significantly increased cell proliferation, and the 1 ng/ml to 1 µg/ml concentrations significantly increased collagen synthesis. The maximum effects for both parameters were observed at 10 ng/ml. P. ginseng stimulated human dermal fibroblast proliferation and collagen synthesis at an optimal concentration of 10 ng/ml.

  5. Implanted neonatal human dermal fibroblasts influence the recruitment of endothelial cells in mice

    PubMed Central

    Guerreiro, Susana G.; Brochhausen, Christoph; Negrão, Rita; Barbosa, Mário A.; Unger, Ronald E.; Kirkpatrick, C. James; Soares, Raquel; Granja, Pedro L.

    2012-01-01

    The vascularization of new tissue within a reasonable time is a crucial prerequisite for the success of different cell- and material-based strategies. Considering that angiogenesis is a multi-step process involving humoral and cellular regulatory components, only in vivo assays provide the adequate information about vessel formation and the recruitment of endothelial cells. The present study aimed to investigate if neonatal human dermal fibroblasts could influence in vivo neovascularization. Results obtained showed that fibroblasts were able to recruit endothelial cells to vascularize the implanted matrix, which was further colonized by murine functional blood vessels after one week. The vessels exhibited higher levels of hemoglobin, compared with the control matrix, implanted without fibroblasts, in which no vessel formation could be observed. No significant differences were detected in systemic inflammation. The presence of vessels originated from the host vasculature suggested that host vascular response was involved, which constitutes a fundamental aspect in the process of neovascularization. Fibroblasts implanted within matrigel increased the presence of endothelial cells with positive staining for CD31 and for CD34 and the production of collagen influencing the angiogenic process and promoting the formation of microvessels. New strategies in tissue engineering could be delineated with improved angiogenesis using neonatal fibroblasts. PMID:23507785

  6. Management of complex abdominal wall defects using acellular porcine dermal collagen.

    PubMed

    Chavarriaga, Luis Felipe; Lin, Edward; Losken, Albert; Cook, Michael W; Jeansonne, Louis O; White, Brent C; Sweeney, John F; Galloway, John R; Davis, S Scott

    2010-01-01

    Multiple techniques have been used for the repair of complex abdominal wall defects after recurrent incisional hernias with varying rates of success. Primary repair has been associated with high recurrence rates, and prosthetic mesh placement is contraindicated in contaminated surgical fields. The development of biologic prostheses has changed the approach to these difficult problems. This study evaluates the management of complex abdominal wall defects using acellular porcine dermal collagen. Between August 2006 and May 2007, 18 patients underwent abdominal wall reconstruction for complex defects with acellular porcine dermal collagen (CollaMend; Bard Inc., Warwick, RI). Patient demographics, preoperative risk factors, previous herniorrhaphy attempts, postoperative complications, recurrences, and long-term results were retrospectively reviewed. Records were reviewed at a mean follow up of 7.3 months; the recurrence rate was 44.4 per cent. A total of 38.9 per cent (seven of 18) developed a postoperative wound complications, including infection in 22.2 per cent (four of 18). All of the patients with infection required prosthesis removal as a result of encapsulation rather than incorporation of the biologic prosthesis. Acellular porcine dermal collagen has the potential for reconstruction of abdominal wall defects with postoperative wound occurrences comparable with other biologic materials. Encapsulation of the material was a major problem in cases with wound infection that required graft removal rather than local wound measures. Hernia recurrence and dehiscence of the graft were problems in noncompromised surgical fields.

  7. Engineered Pullulan–Collagen Composite Dermal Hydrogels Improve Early Cutaneous Wound Healing

    PubMed Central

    Wong, Victor W.; Rustad, Kristine C.; Galvez, Michael G.; Neofytou, Evgenios; Glotzbach, Jason P.; Januszyk, Michael; Major, Melanie R.; Sorkin, Michael; Longaker, Michael T.; Rajadas, Jayakumar

    2011-01-01

    New strategies for skin regeneration are needed to address the significant medical burden caused by cutaneous wounds and disease. In this study, pullulan–collagen composite hydrogel matrices were fabricated using a salt-induced phase inversion technique, resulting in a structured yet soft scaffold for skin engineering. Salt crystallization induced interconnected pore formation, and modification of collagen concentration permitted regulation of scaffold pore size. Hydrogel architecture recapitulated the reticular distribution of human dermal matrix while maintaining flexible properties essential for skin applications. In vitro, collagen hydrogel scaffolds retained their open porous architecture and viably sustained human fibroblasts and murine mesenchymal stem cells and endothelial cells. In vivo, hydrogel-treated murine excisional wounds demonstrated improved wound closure, which was associated with increased recruitment of stromal cells and formation of vascularized granulation tissue. In conclusion, salt-induced phase inversion techniques can be used to create modifiable pullulan–collagen composite dermal scaffolds that augment early wound healing. These novel biomatrices can potentially serve as a structured delivery template for cells and biomolecules in regenerative skin applications. PMID:20919949

  8. Supracrestal circular collagen fiber network around osseointegrated nonsubmerged titanium implants.

    PubMed

    Ruggeri, A; Franchi, M; Marini, N; Trisi, P; Piatelli, A

    1992-12-01

    Eight non-submerged titanium implant screws were placed in the first upper molar edentulous sites of monkeys and subsequently kept loaded with single crown prosthesis 1 month following implantation. The animals were killed after a further 14 months and specimens including implant and adjacent teeth were processed for light and electron microscopy. Histological pictures of all samples showed the neck and most of the screw body to be surrounded by new bone. The soft tissue surrounding the implant post included pocket epithelium and supra-crestal connective tissue displaying collagen fiber bundles comparable to gingival ligaments. These peri-implant collagen fiber bundles arose from the neighboring alveolar crest, root cementum of adjacent teeth or, superficially, from the epithelium and followed a circular array around the implant neck.

  9. B lymphocytes and B-cell activating factor promote collagen and profibrotic markers expression by dermal fibroblasts in systemic sclerosis

    PubMed Central

    2013-01-01

    Introduction B lymphocytes might play a pathogenic role in dermal fibrosis in systemic sclerosis (SSc). B-cell activating factor (BAFF), a key cytokine for B-cell activation, is increased in the serum and the skin of patients with SSc. However, the ability of B cells directly to stimulate dermal fibroblasts and the role of BAFF are not fully understood. We therefore investigated the involvement of B cells and BAFF in the expression of collagen and profibrotic markers by dermal fibroblasts. Methods Cocultures of blood B cells from healthy blood donors and normal or SSc dermal fibroblasts stimulated with anti-IgM and BAFF were performed. Alpha-SMA, TIMP1, MMP9, COL1A1, COL1A2, and COL3A1 mRNA expression were determined by quantitative RT-PCR. Soluble collagen, BAFF, IL-6, IL-1β, TGF-β1, and CCL2 protein secretion were assessed. Results Coculture of blood B cells and dermal fibroblasts isolated from SSc patients induced IL-6, TGF-β1, CCL2, and collagen secretion, as well as Alpha-SMA, TIMP1, and MMP9 expression in dermal fibroblasts. Transwell assays demonstrated that this induction was dependent on cell-cell contact. Addition of anti-IgM and BAFF to the coculture increased IL-6, CCL2, TGF-β1, and collagen secretion. B cell- and BAFF-induced collagen secretion was highly reduced by anti-TGF-β1 antibodies. Conclusions Our results showed for the first time a direct role of B cells on the production of collagen by dermal fibroblasts, which is further enhanced by BAFF. Thus, these results demonstrate a new pathogenic role of B cells and BAFF in fibrosis and systemic sclerosis. PMID:24289101

  10. Preparation and characterization of an advanced collagen aggregate from porcine acellular dermal matrix.

    PubMed

    Liu, Xinhua; Dan, Nianhua; Dan, Weihua

    2016-07-01

    The objective of this study was to extract and characterize an advanced collagen aggregate (Ag-col) from porcine acellular dermal matrix (pADM). Based on histological examination, scanning electron microscopy (SEM) and atomic force microscope (AFM), Ag-col was composed of the D-periodic cross-striated collagen fibrils and thick collagen fiber bundles with uneven diameters and non-orientated arrangement. Fourier transform infrared (FTIR) spectra of pADM, Ag-col and Col were similar and revealed the presence of the triple helix. Circular dichroism (CD) analysis exhibited a slightly higher content of α-helix but inappreciably less amount of random coil structure in Ag-col compared to Col. Moreover, imino acid contents of pADM, Ag-col and Col were 222.43, 218.30 and 190.01 residues/1000 residues, respectively. From zeta potential analysis, a net charge of zero was found at pH 6.45 and 6.11 for Ag-col and Col, respectively. Differential scanning calorimetry (DSC) study suggested that the Td of Ag-col was 20°C higher than that of Col as expected, and dynamic mechanical analysis (DMA) indicated that Ag-col possessed a higher storage modulus but similar loss factor compared to Col. Therefore, the collagen aggregate from pADM could serve as a better alternative source of collagens for further applications in food and biological industries. PMID:27039117

  11. Sterile acellular dermal collagen as a treatment for rippling deformity of breast.

    PubMed

    Busse, Brittany; Orbay, Hakan; Sahar, David E

    2014-01-01

    Prosthetic implants are frequently used for breast augmentation and breast reconstruction following mastectomy. Unfortunately, long-term aesthetic results of prosthetic breast restoration may be hindered by complications such as rippling, capsular contracture, and implant malposition. The advent of use of acellular dermal matrices has greatly improved the outcomes of prosthetic breast reconstruction. We describe a case of rippling deformity of breast that was treated using an acellular dermal matrix product, AlloMax. The patient presented with visible rippling of bilateral prosthetic breast implants as well as significant asymmetry of the breasts after multiple excisional biopsies for right breast ductal carcinoma in situ. A 6 × 10 cm piece of AlloMax was placed on the medial aspect of each breast between the implant and the skin flap. Follow-up was performed at 1 week, 3 months, and 1 year following the procedure. The patient recovered well from the surgery and there were no complications. At her first postoperative follow-up the patient was extremely satisfied with the result. At her 3-month and 1-year follow-up she had no recurrence of her previous deformity and no new deformity. PMID:25610697

  12. Structural colouration of mammalian skin: convergent evolution of coherently scattering dermal collagen arrays.

    PubMed

    Prum, Richard O; Torres, Rodolfo H

    2004-05-01

    For more than a century, the blue structural colours of mammalian skin have been hypothesized to be produced by incoherent, Rayleigh or Tyndall scattering. We investigated the colour, anatomy, nanostructure and biophysics of structurally coloured skin from two species of primates - mandrill (Mandrillus sphinx) and vervet monkey (Cercopithecus aethiops) - and two species of marsupials - mouse opossum (Marmosa mexicana) and wooly opossum (Caluromys derbianus). We used two-dimensional (2-D) Fourier analysis of transmission electron micrographs (TEMs) of the collagen arrays in the primate tissues to test whether these structural colours are produced by incoherent or coherent scattering (i.e. constructive interference). The structural colours in Mandrillus rump and facial skin and Cercopithecus scrotum are produced by coherent scattering by quasi-ordered arrays of parallel dermal collagen fibres. The 2-D Fourier power spectra of the collagen arrays from Mandrillus and Cercopithecus reveal ring-shaped distributions of Fourier power at intermediate spatial frequencies, demonstrating a substantial nanostructure of the appropriate spatial frequency to produce the observed blue hues by coherent scattering alone. The Fourier power spectra and the observed reflectance spectra falsify assumptions and predictions of the incoherent, Rayleigh scattering hypothesis. Samples of blue Marmosa and Caluromys scrotum conform generally to the anatomy seen in Mandrillus and Cercopithecus but were not sufficiently well preserved to conduct numerical analyses. Colour-producing collagen arrays in mammals have evolved multiple times independently within the two clades of mammals known to have trichromatic colour vision. Mammalian colour-producing collagen arrays are anatomically and mechanistically identical to structures that have evolved convergently in the dermis of many lineages of birds, the tapetum of some mammals and the cornea of some fishes. These collagen arrays constitute quasi

  13. The use of flow perfusion culture and subcutaneous implantation with fibroblast-seeded PLLA-collagen 3D scaffolds for abdominal wall repair.

    PubMed

    Pu, Fanrong; Rhodes, Nicholas P; Bayon, Yves; Chen, Rui; Brans, Gerben; Benne, Remco; Hunt, John A

    2010-05-01

    Highly cellularised 3D-tissue constructs designed to repair large, complex abdominal wall defects were prepared using poly (lactic acid) (PLLA)-collagen scaffolds in vitro using a flow perfusion bioreactor. The PLLA-collagen scaffolds had a unique structure consisting of a collagen sponge formed within the pores of a mechanically stable knitted mesh of PLLA. The effect of the flow perfusion bioreactor culturing conditions was investigated in vitro for 0, 7, 14 and 28 days on scaffolds seeded with dermal fibroblasts. The cultured constructs were subsequently studied subcutaneously (SC) in an in vivo animal model. The results of in vitro studies demonstrated that the perfusion system facilitated increased cell proliferation and homogenous distribution in the PLLA-collagen scaffolds compared to static conditions. A highly cellularised 3D-tissue construct was formed by 7 days incubation under perfusion conditions, with increased cellularity by the 28 day time point. The in vivo model demonstrated that implanting constructs with high cellularity resulted in exceptional cell stabilisation, with the survival of implanted cells and expression of the phenotypically-relevant extracellular matrix proteins collagen types I and III, studied by fluorescence in situ hybridisation (FISH) and immunohistochemistry. The implantation of this porous PPLA-collagen scaffold seeded with dermal fibroblasts following in vitro maturation using a flow perfusion bioreactor system suggests a significant advance over current state-of-the-art procedures for the reconstruction of large, complex abdominal wall tissue defects. PMID:20219244

  14. Investigation of the effect of hydration on dermal collagen in ex vivo human skin tissue using second harmonic generation microscopy

    NASA Astrophysics Data System (ADS)

    Samatham, Ravikant; Wang, Nicholas K.; Jacques, Steven L.

    2016-02-01

    Effect of hydration on the dermal collagen structure in human skin was investigated using second harmonic generation microscopy. Dog ears from the Mohs micrographic surgery department were procured for the study. Skin samples with subject aged between 58-90 years old were used in the study. Three dimensional Multiphoton (Two-photon and backward SHG) control data was acquired from the skin samples. After the control measurement, the skin tissue was either soaked in deionized water for 2 hours (Hydration) or kept at room temperature for 2 hours (Desiccation), and SHG data was acquired. The data was normalized for changes in laser power and detector gain. The collagen signal per unit volume from the dermis was calculated. The desiccated skin tissue gave higher backward SHG compared to respective control tissue, while hydration sample gave a lower backward SHG. The collagen signal decreased with increase in hydration of the dermal collagen. Hydration affected the packing of the collagen fibrils causing a change in the backward SHG signal. In this study, the use of multiphoton microscopy to study the effect of hydration on dermal structure was demonstrated in ex vivo tissue.

  15. Dynamic testing and in vivo evaluation of dermally implantable luminescent microparticle glucose sensors

    NASA Astrophysics Data System (ADS)

    Long, Ruiqi; Collier, Bradley; Roberts, Jason; McShane, Michael

    2010-02-01

    We have been developing dermally-implantable microparticle glucose sensors to monitor interstitial glucose levels. For these sensors to be deployed in vivo, a matched opto-electronic system to interrogate implanted sensors has been designed and constructed. The aim of this study is to test the capability of the sensor system, including in vivo sensor performance, hardware efficiency and hardware optimization based on test results. This paper will report the results of dynamic in vitro tests of sensor performance and the results of preliminary experiments of implants in animal models.

  16. Intramuscular collagen characteristics of ram, wether, and zeranol-implanted ram lambs.

    PubMed

    Maiorano, G; McCormick, R J; Field, R A; Snowder, G

    1993-07-01

    Eighteen spring-born Columbia ram, wether, and zeranol-implanted ram lambs were studied to determine the influence of castration or zeranol implants on intramuscular collagen (IMC) properties and muscle shear force values. Warner-Bratzler shear force values for longissimus muscle were greatest for ram lambs, intermediate for implanted rams, and least for wethers (P < .05). Nonreducible collagen crosslink concentration was greater in IMC of rams and implanted rams (P < .05). The IMC from rams compared with that from wethers contained proportionately more Type III than Type I collagen (P < .05); values for implanted rams were intermediate. Heat-soluble muscle collagen concentration was greater for rams and implanted rams than for wethers (P < .05); however, insoluble collagen concentration did not differ by treatment. Muscle collagen concentrations were not different for rams, wethers, or implanted rams. Increased shear force values in rams were associated with elevated collagen crosslink concentration and increased proportion of Type III collagen. Greater concentration of soluble collagen in ram IMC neither diminished nor diluted IMC crosslinking. The proportion of heat-labile collagen in the fractions did not reflect the IMC crosslinking profile for ram and wether lambs. Zeranol implantation modified IMC characteristics of rams such that shear force values and some collagen properties were similar to those of wethers.

  17. Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications

    NASA Astrophysics Data System (ADS)

    Laranjeira, Marta S.; Carvalho, Ângela; Pelaez-Vargas, Alejandro; Hansford, Derek; Ferraz, Maria Pia; Coimbra, Susana; Costa, Elísio; Santos-Silva, Alice; Fernandes, Maria Helena; Monteiro, Fernando Jorge

    2014-04-01

    Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol-gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs) and human dermal microvascular endothelial cells (HDMECs) on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves). Our results showed that cells had a higher metabolic activity (HGF, HDMEC) and increased gene expression levels of fibroblast-specific protein-1 (FSP-1) and collagen type I (COL I) on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior.

  18. High-throughput spectral system for interrogation of dermally-implanted luminescent sensors.

    PubMed

    Long, Ruiqi; McShane, Mike

    2012-01-01

    Ratiometric luminescent microparticle sensors have been developed for sensing biochemical targets such as glucose in interstitial fluid, enabling use of dermal implants for on-demand monitoring. For these sensor systems to be deployed in vivo, a matched optoelectronic system for interrogation of dermally-implanted sensors was previously designed, constructed, and evaluated experimentally. During evaluation experiments, it revealed that the system efficiency was compromised by losses due to fiber connections of a commercial spectrometer. In this work, a high-throughput spectral system was presented to solve the photon loss problem. This system was designed, constructed, and tested. The throughput was around hundred time more than the previous system we used, and it was cost-effective, as well. It enables use of an integrated system for excitation, collection and measurement of luminescent emission, and will be used as a tool for in vivo studies with animal models or human subjects. PMID:23366396

  19. Polyurethane membrane/knitted mesh-reinforced collagen-chitosan bilayer dermal substitute for the repair of full-thickness skin defects via a two-step procedure.

    PubMed

    Wang, Xingang; Wu, Pan; Hu, Xiuyuan; You, Chuangang; Guo, Rui; Shi, Haifei; Guo, Songxue; Zhou, Hanlei; Yu, Chaoheng; Zhang, Yuanhai; Han, Chunmao

    2016-03-01

    The advent of dermal substitutes provides a revolutionary strategy for the repair and reconstruction of deep skin defects. Dermal substitutes form a regenerative template that provides the porous structure and mechanical support necessary to guide cell migration, deposition of the extracellular matrix (ECM) and angiogenesis. Commercially available dermal substitutes, particularly collagen-based dermal scaffolds, are widely used in clinical practice. However, the poor mechanical properties of collagen-based dermal scaffolds compromise their biological effects, as well as the repair outcomes. Here, we describe a bilayer dermal substitute prepared by integrating a hybrid dermal scaffold with a polyurethane (PU) membrane to obtain a PU membrane/knitted mesh-reinforced collagen-chitosan bilayer dermal substitute (PU-PLGAm/CCS). The morphology of PU-PLGAm/CCS was investigated and, to characterize the effects of PU-PLGAm/CCS on tissue regeneration, dermal substitutes were transplanted to repair full-thickness skin wounds in Sprague-Dawley rats using a two-step surgical procedure. These results were then compared with those obtained using the PELNAC™ Artificial Dermis. In the weeks after the first operation, wound changes were analysed based on macroscopic observations, and tissue specimens were harvested for histology, immunohistochemistry, immunofluorescence real-time quantitative PCR, and Western blotting analysis. Following the second operation (i.e., transplantation of split-thickness skin grafts), the repair outcomes were investigated based on the mechanical strength and ECM expression. PU-PLGAm/CCS significantly inhibited wound contracture, promoted angiogenesis, and facilitated the ordered arrangement of neotissue, such that the repair outcomes were improved in the PU-PLGAm/CCS group compared with the PELNAC™ group. In conclusion, the favourable microstructure and structural stability of dermal substitutes facilitated tissue regeneration. PU-PLGAm/CCS achieved

  20. Evaluation of porcine dermal collagen (Permacol) used in abdominal wall reconstruction.

    PubMed

    Hsu, Patrick W; Salgado, Christopher J; Kent, Kathryn; Finnegan, Matthew; Pello, Mark; Simons, Robert; Atabek, Umur; Kann, Brian

    2009-11-01

    Various methods have been employed to reconstruct complex abdominal wall defects. Structural prosthetic materials such as polypropylene mesh and ePTFE (expanded polytetrafluoroethylene) have been widely used to close these large fascial defects, however, complications with infection and adhesions have led to the recent use of more biocompatible implants. Permacol (acellular porcine dermis) is used as a dermal scaffold, which eventually becomes vascularised and remodelled to reconstruct the abdominal wall in these complex patients. A retrospective review was performed of all patients who underwent consecutive abdominal wall reconstruction with Permacol at our institution in the year 2006. Twenty-eight patients were identified and included in our study. Factors evaluated were: body mass index, relevant co-morbidities, aetiology of hernia, hernia defect size based on CT scan and intraoperative measurement, size of Permacol implant, length of hospital stay, and postoperative complications. Surgical technique was standardised among six surgeons and involved a single layer of acellular porcine dermis as a subfascial 'underlay' graft under moderate tension upon maximal hernia reduction. Tissue expanders were not required for skin closure. Out of 28 patients, 12 were male and 16 were female. Mean intraoperative hernia size was 150 cm(2) (range of 10 cm(2) to 600 cm(2)). Mean age was 55 years with an average body mass index (BMI) of 34 (largest BMI of 61.4). Defects were attributed to either a previous laparotomy incision or open abdomen. Mean hospital stay was 9.67 days. At a mean follow-up of sixteen months, there were three recurrent hernias (10.7%) based on physical examination and postoperative CT scan evaluation. One patient developed a superficial wound dehiscence which was successfully treated with local wound care and one patient developed a cellulitis which was successfully treated with antibiotic therapy. Four patients (14.3%) developed a chronic, non

  1. Altered dermal fibroblast behavior in a collagen V haploinsufficient murine model of classic Ehlers-Danlos syndrome.

    PubMed

    DeNigris, John; Yao, Qingmei; Birk, Erika K; Birk, David E

    2016-01-01

    Mutations in collagen V are associated with classic Ehlers-Danlos syndrome (EDS). A significant percentage of these mutations result in haploinsufficiency for collagen V. The purpose of this work was to determine if changes in collagen V expression are associated with altered dermal fibroblast behavior contributing to the poor wound healing response. A haploinsufficient Col5a1(+/-) mouse model of EDS was utilized. In vivo wound healing studies demonstrated that mutant mice healed significantly slower than Col5a1(+/+) mice. The basis for this difference was examined in vitro using dermal fibroblast strains isolated from Col5a1(+/-) and Col5a1(+/+) mice. Fibroblast proliferation was determined for each strain by counting cells at different time points after seeding as well as using the proliferation marker Ki-67. Fibroblast attachment to collagens I and III and fibronectin also was analyzed. In addition, in vitro scratch wounds were used to analyze fibroblast wound closure. Significantly decreased fibroblast proliferation was observed in Col5a1(+/-) compared to Col5a1(+/+) fibroblasts. Our data indicate that the decreased fibroblast number was not due to apoptosis. Wildtype Col5a1(+/+) fibroblasts attached significantly better to components of the wound matrix (collagens I and III and fibronectin) than Col5a1(+/-) fibroblasts. A significant difference in in vitro scratch wound closure rates also was observed. Col5a1(+/+) fibroblasts closed wounds in 22 h, while Col5a1(+/-) fibroblasts demonstrated ~80% closure. There were significant differences in closure at all time points analyzed. Our data suggest that decreased fibroblast proliferation, extracellular matrix attachment, and migration contribute to the decreased wound healing response in classic EDS.

  2. Altered dermal fibroblast behavior in a collagen V haploinsufficient murine model of classic Ehlers-Danlos syndrome.

    PubMed

    DeNigris, John; Yao, Qingmei; Birk, Erika K; Birk, David E

    2016-01-01

    Mutations in collagen V are associated with classic Ehlers-Danlos syndrome (EDS). A significant percentage of these mutations result in haploinsufficiency for collagen V. The purpose of this work was to determine if changes in collagen V expression are associated with altered dermal fibroblast behavior contributing to the poor wound healing response. A haploinsufficient Col5a1(+/-) mouse model of EDS was utilized. In vivo wound healing studies demonstrated that mutant mice healed significantly slower than Col5a1(+/+) mice. The basis for this difference was examined in vitro using dermal fibroblast strains isolated from Col5a1(+/-) and Col5a1(+/+) mice. Fibroblast proliferation was determined for each strain by counting cells at different time points after seeding as well as using the proliferation marker Ki-67. Fibroblast attachment to collagens I and III and fibronectin also was analyzed. In addition, in vitro scratch wounds were used to analyze fibroblast wound closure. Significantly decreased fibroblast proliferation was observed in Col5a1(+/-) compared to Col5a1(+/+) fibroblasts. Our data indicate that the decreased fibroblast number was not due to apoptosis. Wildtype Col5a1(+/+) fibroblasts attached significantly better to components of the wound matrix (collagens I and III and fibronectin) than Col5a1(+/-) fibroblasts. A significant difference in in vitro scratch wound closure rates also was observed. Col5a1(+/+) fibroblasts closed wounds in 22 h, while Col5a1(+/-) fibroblasts demonstrated ~80% closure. There were significant differences in closure at all time points analyzed. Our data suggest that decreased fibroblast proliferation, extracellular matrix attachment, and migration contribute to the decreased wound healing response in classic EDS. PMID:26713685

  3. Three-dimensional, multiwavelength Monte Carlo simulations of dermally implantable luminescent sensors.

    PubMed

    Long, Ruiqi; McShane, Mike

    2010-01-01

    Dermally implanted luminescent sensors have been proposed for monitoring of tissue biochemistry, which has the potential to improve treatments for conditions such as diabetes and kidney failure. Effective in vivo monitoring via noninvasive transdermal measurement of emission from injected microparticles requires a matched optoelectronic system for excitation and collection of luminescence. We applied Monte Carlo modeling to predict the characteristics of output luminescence from microparticles in skin to facilitate hardware design. Three-dimensional, multiwavelength Monte Carlo simulations were used to determine the spatial and spectral distribution of the escaping luminescence for different implantation depths, excitation light source properties, particle characteristics, and particle packing density. Results indicate that the ratio of output emission to input excitation power ranged 10(-3) to 10(-6) for sensors at the upper and lower dermal boundaries, respectively, and 95% of the escaping emission photons induced by a 10-mm-diam excitation beam were confined within an 18-mm circle. Tightly packed sensor configurations yielded higher output intensity with fewer particles, even after luminophore concentration effects were removed. Most importantly, for the visible wavelengths studied, the ability to measure spectral changes in emission due to glucose changes was not significantly affected by absorption and scattering of tissue, which supports the potential to accurately track changes in luminescence of sensor implants that respond to the biochemistry of the skin. PMID:20459285

  4. Three-dimensional, multiwavelength Monte Carlo simulations of dermally implantable luminescent sensors

    NASA Astrophysics Data System (ADS)

    Long, Ruiqi; McShane, Mike

    2010-03-01

    Dermally implanted luminescent sensors have been proposed for monitoring of tissue biochemistry, which has the potential to improve treatments for conditions such as diabetes and kidney failure. Effective in vivo monitoring via noninvasive transdermal measurement of emission from injected microparticles requires a matched optoelectronic system for excitation and collection of luminescence. We applied Monte Carlo modeling to predict the characteristics of output luminescence from microparticles in skin to facilitate hardware design. Three-dimensional, multiwavelength Monte Carlo simulations were used to determine the spatial and spectral distribution of the escaping luminescence for different implantation depths, excitation light source properties, particle characteristics, and particle packing density. Results indicate that the ratio of output emission to input excitation power ranged 10-3 to 10-6 for sensors at the upper and lower dermal boundaries, respectively, and 95% of the escaping emission photons induced by a 10-mm-diam excitation beam were confined within an 18-mm circle. Tightly packed sensor configurations yielded higher output intensity with fewer particles, even after luminophore concentration effects were removed. Most importantly, for the visible wavelengths studied, the ability to measure spectral changes in emission due to glucose changes was not significantly affected by absorption and scattering of tissue, which supports the potential to accurately track changes in luminescence of sensor implants that respond to the biochemistry of the skin.

  5. Aging decreases collagen IV expression in vivo in the dermo-epidermal junction and in vitro in dermal fibroblasts: possible involvement of TGF-β1.

    PubMed

    Feru, Jezabel; Delobbe, Etienne; Ramont, Laurent; Brassart, Bertrand; Terryn, Christine; Dupont-Deshorgue, Aurelie; Garbar, Christian; Monboisse, Jean-Claude; Maquart, Francois-Xavier; Brassart-Pasco, Sylvie

    2016-08-01

    Collagen IV is a major component of the dermo-epidermal junction (DEJ). To study expression of collagen IV upon aging in the DEJ and dermal fibroblasts isolated from the same patients. A model of senescent fibroblasts was developed in order to identify biological compounds that might restore the level of collagen IV. Skin fragments of women (30 to 70 years old) were collected. Localisation of collagen IV expression in the DEJ was studied by immunofluorescence. Fibroblast collagen IV expression was studied by real-time PCR, ELISA, and western blotting. Premature senescence was simulated by exposing fibroblasts to subcytotoxic H2O2 concentrations. Collagen IV decreased in the DEJ and fibroblasts relative to age. TGF-β1 treatment significantly increased collagen IV gene and protein expression in fibroblasts and restored expression in the model of senescence. Addition of TGF-β1-neutralizing antibody to fibroblast cultures decreased collagen IV expression. Taken together, the results suggest that the decrease in collagen IV in the DEJ, relative to age, could be due to a decrease in collagen IV expression by senescent dermal fibroblasts and may involve TGF-β1 signalling. PMID:27124123

  6. Integrin α_vβ_3 Rescues Melanoma Cells from Apoptosis in Three-Dimensional Dermal Collagen

    NASA Astrophysics Data System (ADS)

    Montgomery, Anthony M. P.; Reisfeld, Ralph A.; Cheresh, David A.

    1994-09-01

    Human melanoma cells required ligation of the integrin α_vβ_3 to sustain viability and growth in three-dimensional dermal collagen. Variant melanoma cells, lacking the α_v subunit, progressed rapidly to apoptosis within this matrix, whereas transfection of these cells with an α_v cDNA restored α_vβ_3 expression and prevented apoptosis. Furthermore, inhibition of α_vβ_3 ligation with a monoclonal antibody promoted cell death. Apoptosis of α_v(-) cells within this matrix could be overcome by the addition of insulin or serum. However, α_v(+) melanoma cells had a significant growth advantage in the presence of these growth factors. Initial adhesion of the melanoma cells to type I collagen depended on ligation of α_2β_1, but these cells can degrade this collagen to expose cryptic α_vβ_3 binding sites. These findings provide evidence that the survival and growth of transformed cells may be regulated by collagen degradation and integrin-dependent anchorage to this proteolysed matrix.

  7. Up-regulated type I collagen expression by the inhibition of Rac1 signaling pathway in human dermal fibroblasts.

    PubMed

    Igata, Toshikatsu; Jinnin, Masatoshi; Makino, Takamitsu; Moriya, Chikako; Muchemwa, Faith C; Ishihara, Tsuyoshi; Ihn, Hironobu

    2010-02-26

    Tissue remodeling is known to play important roles in wound healing. Although Rac1 is reported to be one of the key signaling molecules in cutaneous wound healing process, the exact mechanisms of Rac1-mediated tissue remodeling is still unknown. This study investigated the role of Rac1 in the regulation of extracellular matrix in cultured human dermal fibroblasts obtained by skin biopsy from three healthy donors. Protein levels of type I collagen in cultured human fibroblasts were increased by the treatment with Rac1 inhibitor NSC23766 in a dose-dependent manner. However, the mRNA levels of alpha2(I) collagen was not altered by the inhibitor. On the other hand, by the addition of inhibitor, half-lives of type I collagen protein were increased and MMP1 levels were reduced. These data suggest that blockade of Rac1 signaling results in accumulation of type I collagen due to decreased collagenase activity. This study also suggests that controlling Rac1 signaling is a new therapeutic approach to chronic/untreatable ulcer.

  8. Implantation of sepiolite-collagen complexes in surgically created rat calvaria defects.

    PubMed

    Herrera, J I; Olmo, N; Turnay, J; Sicilia, A; Bascones, A; Gavilanes, J G; Lizarbe, M A

    1995-05-01

    The response of osseous tissue to the implantation of sepiolite-collagen complexes has been studied. Sepiolite, sepiolite-collagen complex and 0.5% glutaraldehyde-treated sepiolite-collagen complex were implanted in created circular defects in rat calvaria. The tissue reactions were analysed using light, transmission and scanning electron microscopies. The patterns of bone growth were radiographically analysed and the bone activity was indirectly quantified by using a point-count method. The reaction against the three implanted materials is characteristic of a foreign body reaction with abundant macrophages and giant cells. Implanted products have been detected in macrophages, which suggest the involvement of phagocytosis in the resorptive process. Bone grew at the implantation sites originating excrescences or sometimes a thin bridge at the defect margins. The studied materials, after implantation in contact with bone tissue, did not produce any toxic effect or necrosis, allowing bone activity. PMID:7548613

  9. Implantation of sepiolite-collagen complexes in surgically created rat calvaria defects.

    PubMed

    Herrera, J I; Olmo, N; Turnay, J; Sicilia, A; Bascones, A; Gavilanes, J G; Lizarbe, M A

    1995-05-01

    The response of osseous tissue to the implantation of sepiolite-collagen complexes has been studied. Sepiolite, sepiolite-collagen complex and 0.5% glutaraldehyde-treated sepiolite-collagen complex were implanted in created circular defects in rat calvaria. The tissue reactions were analysed using light, transmission and scanning electron microscopies. The patterns of bone growth were radiographically analysed and the bone activity was indirectly quantified by using a point-count method. The reaction against the three implanted materials is characteristic of a foreign body reaction with abundant macrophages and giant cells. Implanted products have been detected in macrophages, which suggest the involvement of phagocytosis in the resorptive process. Bone grew at the implantation sites originating excrescences or sometimes a thin bridge at the defect margins. The studied materials, after implantation in contact with bone tissue, did not produce any toxic effect or necrosis, allowing bone activity.

  10. In vitro dermal and epidermal cellular response to titanium alloy implants fabricated with electron beam melting.

    PubMed

    Springer, Jessica Collins; Harrysson, Ola L A; Marcellin-Little, Denis J; Bernacki, Susan H

    2014-10-01

    Transdermal osseointegrated prostheses (TOPs) are emerging as an alternative to socket prostheses. Electron beam melting (EBM) is a promising additive manufacturing technology for manufacture of custom, freeform titanium alloy (Ti6Al4V) implants. Skin ongrowth for infection resistance and mechanical stability are critically important to the success of TOP, which can be influenced by material composition and surface characteristics. We assessed viability and proliferation of normal human epidermal keratinocytes (NHEK) and normal human dermal fibroblasts (NHDF) on several Ti6Al4V surfaces: solid polished commercial, solid polished EBM, solid unpolished EBM and porous unpolished EBM. Cell proliferation was evaluated at days 2 and 7 using alamarBlue(®) and cell viability was analyzed with a fluorescence-based live-dead assay after 1 week. NHDF and NHEK were viable and proliferated on all Ti6Al4V surfaces. NHDF proliferation was highest on commercial and EBM polished surfaces. NHEK was highest on commercial polished surfaces. All EBM Ti6Al4V discs exhibited an acceptable biocompatibility profile compared to solid Ti6Al4V discs from a commercial source for dermal and epidermal cells. EBM may be considered as an option for fabrication of custom transdermal implants.

  11. RNAi functionalized collagen-chitosan/silicone membrane bilayer dermal equivalent for full-thickness skin regeneration with inhibited scarring.

    PubMed

    Liu, Xing; Ma, Lie; Liang, Jun; Zhang, Bing; Teng, Jianying; Gao, Changyou

    2013-03-01

    Scar inhibition of dermal equivalent is one of the key issues for treatment of full thickness skin defects. To yield a bioactive RNAi functionalized matrix for skin regeneration with inhibited scarring, collagen-chitosan/silicone membrane bilayer dermal equivalent (BDE) was combined with trimetylchitosan (TMC)/siRNA complexes which could induce suppression of transforming growth factor-β1 (TGF-β1) pathway. The RNAi-BDE functioned as a reservoir for the incorporated TMC/siRNA complexes, enabling a prolonged siRNA release. The seeded fibroblasts in the RNAi-BDE showed good viability, internalized the TMC/siRNA complexes effectively and suppressed TGF-β1 expression constantly until 14 d. Application of the RNAi-BDE on the full-thickness skin defects of pig backs confirmed the in vivo inhibition of TGF-β1 expression by immunohistochemistry, real-time quantitative PCR and western blotting during 30 d post surgery. The levels of other scar-related factors such as collagen type I, collagen type III and α-smooth muscle actin (α-SMA) were also down-regulated. In combination with the ultra-thin skin graft transplantation for 73 d, the regenerated skin by RNAi-BDE had an extremely similar structure to that of the normal one. Our study reflects the latest paradigm of tissue engineering by incorporating the emerging biomolecule siRNA. The 3-D scaffolding materials for siRNA delivery may have general implications in generation of bioactive matrix as well. PMID:23261213

  12. Plasma mediated collagen-I-coating of metal implant materials to improve biocompatibility.

    PubMed

    Hauser, Joerg; Koeller, Manfred; Bensch, Sebastian; Halfmann, Helmut; Awakowicz, Peter; Steinau, Hans-Ulrich; Esenwein, Stefan

    2010-07-01

    This study describes the collagen-I coating of titanium and steel implants via cold low-pressure gas plasma treatment. To analyze the coatings in terms of biocompatibility osteoblast-like osteosarcoma cells and human leukocytes were cultivated on the metal surfaces. Two different implant materials were assessed (Ti6Al4V, X2CrNiMo18) and four different surface properties were evaluated: (a) plasma pretreated and collagen-I coated implant materials; (b) collagen-I dip-coated without plasma pretreatment; (c) plasma treated but not collagen-I coated; (d) standard implant materials served as control. The different coating characteristics were analyzed by scanning electron microscopy (SEM). For adhesion and viability tests calcein-AM staining of the cells and Alamar blue assays were performed. The quantitative analysis was conducted by computer assisted microfluorophotography and spectrometer measurements. SEM analysis revealed that stable collagen-I coatings could not be achieved on the dip-coated steel and titanium alloys. Only due to pretreatment with low-pressure gas plasma a robust deposition of collagen I on the surface could be achieved. The cell viability and cell attachment rate on the plasma pretreated, collagen coated surfaces was significantly (p < 0.017) increased compared to the non coated surfaces. Gas plasma treatment is a feasible method for the deposition of proteins on metal implant materials resulting in an improved biocompatibility in vitro. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

  13. Modified Lower Pole Autologous Dermal Sling for Implant Reconstruction in Women Undergoing Immediate Breast Reconstruction after Mastectomy

    PubMed Central

    2016-01-01

    Background. Autologous dermal sling with wise pattern skin reducing mastectomy allows one-stage implant reconstruction in women with large and ptotic breasts needing mastectomy for cancer or risk reduction. However, this technique is not suitable for women who lack ptosis and also carries risk of T-junction breakdown. Method. We have performed one-stage nipple sparing mastectomies with implant reconstruction in 5 women (8 breasts) by modifying the autologous dermal sling approach. All these women had small to moderate breasts with no ptosis or pseudoptosis. Results. Three women had bilateral procedures, two underwent bilateral mastectomies simultaneously, and one had contralateral risk reduction surgery a year after the cancer side operation. All women underwent direct to implant reconstruction with implant volumes varying from 320 to 375 cc. There were no implant losses and only one required further surgery to excise the nipple for positive nipple shaves. A low complication rate was encountered in this series with good aesthetic outcome. Conclusion. The modified lower pole dermal sling allows direct to implant reconstruction in selected women with small to moderate sized breasts with minimal ptosis. The approach is safe and cost-effective and results in more natural reconstruction with preservation of nipple.

  14. Suppression of α Smooth Muscle Actin Accumulation by Bovine Fetal Dermal Collagen Matrix in Full Thickness Skin Wounds.

    PubMed

    Lineaweaver, William; Bush, Katie; James, Kenneth

    2015-06-01

    The suppression of elements associated with wound contracture and unfavorable scarring is a potentially important strategy in clinical wound management. In this study, the presence of α smooth muscle actin (αSMA), a protein involved in wound contraction, was analyzed in a series of wounds in which bovine fetal collagen (BFC) acellular dermal matrix (PriMatrix) was used in staged split thickness skin graft procedures. The results obtained through histological and quantitative image analyses of incidental biopsies from these wounds demonstrated a suppression of αSMA in the wound regions occupied by assimilated BFC relative to increased levels of αSMA found in other areas of the wound. The αSMA levels found in assimilated BFC were similar to αSMA levels in uninjured human dermis. These findings suggest a mechanism by which application of BFC could decrease contraction of full thickness skin wounds.

  15. Suppression of α Smooth Muscle Actin Accumulation by Bovine Fetal Dermal Collagen Matrix in Full Thickness Skin Wounds

    PubMed Central

    Lineaweaver, William; Bush, Katie; James, Kenneth

    2015-01-01

    Abstract The suppression of elements associated with wound contracture and unfavorable scarring is a potentially important strategy in clinical wound management. In this study, the presence of α smooth muscle actin (αSMA), a protein involved in wound contraction, was analyzed in a series of wounds in which bovine fetal collagen (BFC) acellular dermal matrix (PriMatrix) was used in staged split thickness skin graft procedures. The results obtained through histological and quantitative image analyses of incidental biopsies from these wounds demonstrated a suppression of αSMA in the wound regions occupied by assimilated BFC relative to increased levels of αSMA found in other areas of the wound. The αSMA levels found in assimilated BFC were similar to αSMA levels in uninjured human dermis. These findings suggest a mechanism by which application of BFC could decrease contraction of full thickness skin wounds. PMID:25695450

  16. Chum salmon egg extracts induce upregulation of collagen type I and exert antioxidative effects on human dermal fibroblast cultures

    PubMed Central

    Yoshino, Atsushi; Polouliakh, Natalia; Meguro, Akira; Takeuchi, Masaki; Kawagoe, Tatsukata; Mizuki, Nobuhisa

    2016-01-01

    Components of fish roe possess antioxidant and antiaging activities, making them potentially very beneficial natural resources. Here, we investigated chum salmon eggs (CSEs) as a source of active ingredients, including vitamins, unsaturated fatty acids, and proteins. We incubated human dermal fibroblast cultures for 48 hours with high and low concentrations of CSE extracts and analyzed changes in gene expression. Cells treated with CSE extract showed concentration-dependent upregulation of collagen type I genes and of multiple antioxidative genes, including OXR1, TXNRD1, and PRDX family genes. We further conducted in silico phylogenetic footprinting analysis of promoter regions. These results suggested that transcription factors such as acute myeloid leukemia-1a and cyclic adenosine monophosphate response element-binding protein may be involved in the observed upregulation of antioxidative genes. Our results support the idea that CSEs are strong candidate sources of antioxidant materials and cosmeceutically effective ingredients. PMID:27621603

  17. Chum salmon egg extracts induce upregulation of collagen type I and exert antioxidative effects on human dermal fibroblast cultures.

    PubMed

    Yoshino, Atsushi; Polouliakh, Natalia; Meguro, Akira; Takeuchi, Masaki; Kawagoe, Tatsukata; Mizuki, Nobuhisa

    2016-01-01

    Components of fish roe possess antioxidant and antiaging activities, making them potentially very beneficial natural resources. Here, we investigated chum salmon eggs (CSEs) as a source of active ingredients, including vitamins, unsaturated fatty acids, and proteins. We incubated human dermal fibroblast cultures for 48 hours with high and low concentrations of CSE extracts and analyzed changes in gene expression. Cells treated with CSE extract showed concentration-dependent upregulation of collagen type I genes and of multiple antioxidative genes, including OXR1, TXNRD1, and PRDX family genes. We further conducted in silico phylogenetic footprinting analysis of promoter regions. These results suggested that transcription factors such as acute myeloid leukemia-1a and cyclic adenosine monophosphate response element-binding protein may be involved in the observed upregulation of antioxidative genes. Our results support the idea that CSEs are strong candidate sources of antioxidant materials and cosmeceutically effective ingredients. PMID:27621603

  18. Chum salmon egg extracts induce upregulation of collagen type I and exert antioxidative effects on human dermal fibroblast cultures

    PubMed Central

    Yoshino, Atsushi; Polouliakh, Natalia; Meguro, Akira; Takeuchi, Masaki; Kawagoe, Tatsukata; Mizuki, Nobuhisa

    2016-01-01

    Components of fish roe possess antioxidant and antiaging activities, making them potentially very beneficial natural resources. Here, we investigated chum salmon eggs (CSEs) as a source of active ingredients, including vitamins, unsaturated fatty acids, and proteins. We incubated human dermal fibroblast cultures for 48 hours with high and low concentrations of CSE extracts and analyzed changes in gene expression. Cells treated with CSE extract showed concentration-dependent upregulation of collagen type I genes and of multiple antioxidative genes, including OXR1, TXNRD1, and PRDX family genes. We further conducted in silico phylogenetic footprinting analysis of promoter regions. These results suggested that transcription factors such as acute myeloid leukemia-1a and cyclic adenosine monophosphate response element-binding protein may be involved in the observed upregulation of antioxidative genes. Our results support the idea that CSEs are strong candidate sources of antioxidant materials and cosmeceutically effective ingredients.

  19. Transthoracic repair of an incarcerated diaphragmatic hernia using hexamethylene diisocyanate cross-linked porcine dermal collagen (Permacol).

    PubMed

    Gooch, Benn; Smart, Neil; Wajed, Saj

    2012-03-01

    It is the general surgeon who commonly repairs paraesophageal hernias nowadays, and they are repaired laparoscopically, making the performance of thoracotomy relatively rare. Whether to use prosthetic materials to repair the hiatus is still under debate, as is the question of which material to use, if any. We report a case of a 38-year-old man who had a large, incarcerated paraesophageal hernia. He had a past history of extensive abdominal surgery for exomphalos, which rendered any abdominal surgical approach a high-risk procedure. We therefore decided to proceed with thoracotomy and repair of the hiatus with hexamethylene diisocyanate (HMDI) cross-linked porcine dermal collagen. He made a good recovery with no complications. PMID:22419182

  20. Second harmonic generation imaging of dermal collagen component in human keloid tissue

    NASA Astrophysics Data System (ADS)

    Yu, H. B.; Chen, S.; Zhu, X. Q.; Yang, H. Q.; Chen, J. X.

    2011-01-01

    In this paper, we report second harmonic generation (SHG) imaging of human keloid tissue. High resolution SHG images of collagen component were obtained in the superficial, medial and deep dermis of human keloid tissue, respectively. Our results show that this method has a capability to observe the structure of collagen component in human keloid tissue, which will help to better understand the formation process of human keloid scar at the molecular level.

  1. [Morphological tissue changes after the implantation of a biodegradable material on collagen basis].

    PubMed

    Maĭborodin, I V; Beregovoĭ, E A; Shevela, A I; Kuznetsova, I V; Barannik, M I; Manaev, A A; Maĭborodina, V I

    2013-01-01

    The objective of this study was to examine the peculiarities of tissue reactions during the degradation of "Collost" bioplastic material on the collagen basis with completely preserved fibrous structure, after its implantation into the bone tissue defect. The defect in bone tissue sized 1-2 mm x 3-5 mm was created in tibial condyle. The study was performed on 24 Wistar rats using light microscopic methods. The tissue reactions were studied at different time intervals (1, 2, 6 and 12 months) after the implantation of collagenic material. It was found that after the implantation, the material became impregnated with blood, and due to fibrin, densely adhered to the damaged tissues. Further, the cells were found to migrate along the blood clot into its depth from the surrounding tissues. These were primarily the fibroblasts which were located in a network of fibers and started to absorb collagen from a surrounding material and to synthesize new collagen. Gradually, the collagenic material became similar to a cell-containing network. The volume of the newly synthesized collagen increased, and after some time all the foreign material was absorbed by fibroblasts and replaced with connective tissue. After 1 year, a large "Collost" fragment was completely degraded and replaced by loose connective tissue. The implantation of a collagenic material did not stimulate the formation of a delimiting connective tissue capsule PMID:24707743

  2. Repair of meniscal cartilage white zone tears using a stem cell/collagen-scaffold implant.

    PubMed

    Pabbruwe, Moreica B; Kafienah, Wael; Tarlton, John F; Mistry, Sanjay; Fox, Dennis J; Hollander, Anthony P

    2010-03-01

    Injuries to the avascular region of knee meniscal cartilage do not heal spontaneously. To address this problem we have developed a new stem cell/collagen-scaffold implant system in which human adult bone marrow mesenchymal stem cells are seeded onto a biodegradable scaffold that allows controlled delivery of actively dividing cells to the meniscus surface. Sandwich constructs of two white zone ovine meniscus discs with stem cell/collagen-scaffold implant in between were cultured in vitro for 40 days. Histomorphometric analysis revealed superior integration in the stem cell/collagen-scaffold groups compared to the cell-free collagen membrane or untreated controls. The addition of TGF-beta1 to differentiate stem cells to chondrocytes inhibited integration. Biomechanical testing demonstrated a significant 2-fold increase in tensile strength in all constructs using the stem cell/collagen-scaffold compared to control groups after 40 days in culture. Integration was significantly higher when collagen membranes were used that had a more open/spongy structure adjacent to both meniscal cartilage surfaces, whereas a collagen scaffold designed for osteoinduction failed to induce any integration of meniscus. In conclusion, the stem cell/collagen-scaffold implant is a potential therapeutic treatment for the repair of white zone meniscal cartilage tears.

  3. Quantitative fraction evaluation of dermal collagen and elastic fibres in the skin samples obtained in two orientations from the trunk region.

    PubMed

    Kumar, Naveen; Kumar, Pramod; Nayak Badagabettu, Satheesha; Prasad, Keerthana; Kudva, Ranjini; Raghuveer, Coimbatore Vasudevarao

    2014-01-01

    Background. Histomorphic evaluation of dermal collagen and elastic fibres was analysed by image analysis technique. The quantification of dermal elements was performed in skin tissues, collected in horizontal and vertical directions from trunk region and discussed under the perspective of consequences of scar related complications. Materials and Method. Total number of 200 skin samples collected from 5 areas of trunk region were processed histologically and subjected to tissue-quant image analysis. Statistical analysis involving mean with SEM and paired t test by SPSS were employed to the percentage values obtained from image analysis. Result. Among the chosen 5 areas of trunk region, abdomen showed the statistically significant difference for both collagen and elastic content between horizontal and vertical orientations (P< 0.05), whereas upper back, presternal, and lateral chest areas showed significant difference (P< 0.05) only for collagen and groin only for elastic content. Conclusion. The differences in the distribution of dermal collagen and elastic fibres in 2 directions of the samples from the same areas might be attributed to final outcome of wound healing process by influencing the appearance and behaviour of scar related complications in the region of trunk. PMID:25328512

  4. Collagen adsorption on quercetin loaded polycaprolactone microspheres: approach for "stealth" implant.

    PubMed

    Natarajan, Venkatachalam; Saravanakumar, Pandian; Madhan, Balaraman

    2012-05-01

    We recently experimented with collagen coating on the surface of quercetin loaded polycaprolactone microspheres by simple adsorption technique to mimic extra cellular matrix and reduce immune or inflammatory responses at the site of implants. The collagen immobilization on polymeric scaffold surfaces through various surface modification techniques was the current scenario to improve bio-integration of the polymers with the in vivo system. Nevertheless, it requires other chemicals or processing methods to modify the surface of polymers to immobilize the collagen covalently. Here protein adsorption principle is used for the coating of collagen onto the surface of solid microspheres and characterized. Optical, ATR-FTIR, SEM analysis confirm collagen coating. The reduction in burst release of the quercetin from the PCL microspheres further confirms its presence and role in the controlled release. The results indicate that the adsorption technique can be the simple strategy to coat collagen on the surface of polyester implants to develop stealth implant in shorter time with low cost technology.

  5. Alkaline phosphatase induces the mineralization of sheets of collagen implanted subcutaneously in the rat.

    PubMed Central

    Beertsen, W; van den Bos, T

    1992-01-01

    To determine whether alkaline phosphatase (ALP) can cause the mineralization of collagenous matrices in vivo, bovine intestinal ALP was covalently bound to slices of guanidine-extracted demineralized bovine dentin (DDS). The preparations were implanted subcutaneously over the right half of the rat skull. Control slices not treated with the enzyme were implanted over the left half of the skull of the same animals. Specimens were harvested after periods varying from 1 to 4 wk. It was shown that ALP-coupled DDS rapidly accumulated hydroxyapatite crystals. 4 wk after implantation, the content of calcium and phosphate per microgram of hydroxyproline amounted up to 80 and 60%, respectively, of that found in normal bovine dentin. Our observations present direct evidence that ALP may play a crucial role in the induction of hydroxyapatite deposition in collagenous matrices in vivo. Images PMID:1602003

  6. Coating with artificial matrices from collagen and sulfated hyaluronan influences the osseointegration of dental implants.

    PubMed

    Schulz, Matthias C; Korn, Paula; Stadlinger, Bernd; Range, Ursula; Möller, Stephanie; Becher, Jana; Schnabelrauch, Matthias; Mai, Ronald; Scharnweber, Dieter; Eckelt, Uwe; Hintze, Vera

    2014-01-01

    Dental implants are an established therapy for oral rehabilitation. High success rates are achieved in healthy bone, however, these rates decrease in compromised host bone. Coating of dental implants with components of the extracellular matrix is a promising approach to enhance osseointegration in compromised peri-implant bone. Dental titanium implants were coated with an artificial extracellular matrix (aECM) consisting of collagen type I and either one of two regioselectively low sulfated hyaluronan (sHA) derivatives (coll/sHA1Δ6s and coll/sHA1) and compared to commercial pure titanium implants (control). After extraction of the premolar teeth, 36 implants were inserted into the maxilla of 6 miniature pigs (6 implants per maxilla). The healing periods were 4 and 8 weeks, respectively. After animal sacrifice, the samples were evaluated histomorphologically and histomorphometrically. All surface states led to a sufficient implant osseointegration after 4 and 8 weeks. Inflammatory or foreign body reactions could not be observed. After 4 weeks of healing, implants coated with coll/sHA1Δ6s showed the highest bone implant contact (BIC; coll/sHA1Δ6s: 45.4%; coll/sHA1: 42.2%; control: 42.3%). After 8 weeks, a decrease of BIC could be observed for coll/sHA1Δ6s and controls (coll/sHA1Δ6s: 37.3%; control: 31.7 %). For implants coated with coll/sHA1, the bone implant contact increased (coll/sHA1: 50.8%). Statistically significant differences could not be observed. Within the limits of the current study, aECM coatings containing low sHA increase peri-implant bone formation around dental implants in maxillary bone compared to controls in the early healing period.

  7. Coating with artificial matrices from collagen and sulfated hyaluronan influences the osseointegration of dental implants.

    PubMed

    Schulz, Matthias C; Korn, Paula; Stadlinger, Bernd; Range, Ursula; Möller, Stephanie; Becher, Jana; Schnabelrauch, Matthias; Mai, Ronald; Scharnweber, Dieter; Eckelt, Uwe; Hintze, Vera

    2014-01-01

    Dental implants are an established therapy for oral rehabilitation. High success rates are achieved in healthy bone, however, these rates decrease in compromised host bone. Coating of dental implants with components of the extracellular matrix is a promising approach to enhance osseointegration in compromised peri-implant bone. Dental titanium implants were coated with an artificial extracellular matrix (aECM) consisting of collagen type I and either one of two regioselectively low sulfated hyaluronan (sHA) derivatives (coll/sHA1Δ6s and coll/sHA1) and compared to commercial pure titanium implants (control). After extraction of the premolar teeth, 36 implants were inserted into the maxilla of 6 miniature pigs (6 implants per maxilla). The healing periods were 4 and 8 weeks, respectively. After animal sacrifice, the samples were evaluated histomorphologically and histomorphometrically. All surface states led to a sufficient implant osseointegration after 4 and 8 weeks. Inflammatory or foreign body reactions could not be observed. After 4 weeks of healing, implants coated with coll/sHA1Δ6s showed the highest bone implant contact (BIC; coll/sHA1Δ6s: 45.4%; coll/sHA1: 42.2%; control: 42.3%). After 8 weeks, a decrease of BIC could be observed for coll/sHA1Δ6s and controls (coll/sHA1Δ6s: 37.3%; control: 31.7 %). For implants coated with coll/sHA1, the bone implant contact increased (coll/sHA1: 50.8%). Statistically significant differences could not be observed. Within the limits of the current study, aECM coatings containing low sHA increase peri-implant bone formation around dental implants in maxillary bone compared to controls in the early healing period. PMID:24113890

  8. Enhanced regeneration of corneal tissue via a bioengineered collagen construct implanted by a nondisruptive surgical technique.

    PubMed

    Koulikovska, Marina; Rafat, Mehrdad; Petrovski, Goran; Veréb, Zoltán; Akhtar, Saeed; Fagerholm, Per; Lagali, Neil

    2015-03-01

    Severe shortage of donor corneas for transplantation, particularly in developing countries, has prompted the advancement of bioengineered tissue alternatives. Bioengineered corneas that can withstand transplantation while maintaining transparency and compatibility with host cells, and that are additionally amenable to standardized low-cost mass production are sought. In this study, a bioengineered porcine construct (BPC) was developed to function as a biodegradable scaffold to promote corneal stromal regeneration by host cells. Using high-purity medical-grade type I collagen, high 18% collagen content and optimized EDC-NHS cross-linker ratio, BPCs were fabricated into hydrogel corneal implants with over 90% transparency and four-fold increase in strength and stiffness compared with previous versions. Remarkably, optical transparency was achieved despite the absence of collagen fibril organization at the nanoscale. In vitro testing indicated that BPC supported confluent human epithelial and stromal-derived mesenchymal stem cell populations. With a novel femtosecond laser-assisted corneal surgical model in rabbits, cell-free BPCs were implanted in vivo in the corneal stroma of 10 rabbits over an 8-week period. In vivo, transparency of implanted corneas was maintained throughout the postoperative period, while healing occurred rapidly without inflammation and without the use of postoperative steroids. BPC implants had a 100% retention rate at 8 weeks, when host stromal cells began to migrate into implants. Direct histochemical evidence of stromal tissue regeneration was observed by means of migrated host cells producing new collagen from within the implants. This study indicates that a cost-effective BPC extracellular matrix equivalent can incorporate cells passively to initiate regenerative healing of the corneal stroma, and is compatible with human stem or organ-specific cells for future therapeutic applications as a stromal replacement for treating blinding

  9. Direct Hospital Cost of Outcome Pathways in Implant-Based Reconstruction with Acellular Dermal Matrices

    PubMed Central

    Qureshi, Ali A.; Broderick, Kristen; Funk, Susan; Reaven, Nancy; Tenenbaum, Marissa M.

    2016-01-01

    Background: Current cost data on tissue expansion followed by exchange for permanent implant (TE/I) reconstruction lack a necessary assessment of the experience of a heterogenous breast cancer patient population and their multiple outcome pathways. We extend our previous analysis to that of direct hospital cost as bundling of payments is likely to follow the changing centralization of cancer care at the hospital level. Methods: We performed a retrospective analysis (2003–2009) of TE/I reconstructions with or without an acellular dermal matrix (ADM), namely Alloderm RTM. Postreconstructive events were analyzed and organized into outcome pathways as previously described. Aggregated and normalized inpatient and outpatient hospital direct costs and physician reimbursement were generated for each outcome pathway with or without ADM. Results: Three hundred sixty-seven patients were analyzed. The average 2-year hospital direct cost per TE/I breast reconstruction patient was $11,862 in the +ADM and $12,319 in the −ADM groups (P > 0.05). Initial reconstructions were costlier in the +ADM ($6,868) than in the −ADM ($5,615) group, but the average cost of subsequent postreconstructive events within 2 years was significantly lower in +ADM ($5,176) than −ADM ($6,704) patients (P < 0.05). When a complication occurred, but reconstruction was still completed within 2 years, greater costs were incurred in the −ADM than in the +ADM group for most scenarios, leading to a net equalization of cost between study groups. Conclusion: Although direct hospital cost is an important factor for resource and fund allocation, it should not remain the sole factor when deciding to use ADM in TE/I reconstruction.

  10. Direct Hospital Cost of Outcome Pathways in Implant-Based Reconstruction with Acellular Dermal Matrices

    PubMed Central

    Qureshi, Ali A.; Broderick, Kristen; Funk, Susan; Reaven, Nancy; Tenenbaum, Marissa M.

    2016-01-01

    Background: Current cost data on tissue expansion followed by exchange for permanent implant (TE/I) reconstruction lack a necessary assessment of the experience of a heterogenous breast cancer patient population and their multiple outcome pathways. We extend our previous analysis to that of direct hospital cost as bundling of payments is likely to follow the changing centralization of cancer care at the hospital level. Methods: We performed a retrospective analysis (2003–2009) of TE/I reconstructions with or without an acellular dermal matrix (ADM), namely Alloderm RTM. Postreconstructive events were analyzed and organized into outcome pathways as previously described. Aggregated and normalized inpatient and outpatient hospital direct costs and physician reimbursement were generated for each outcome pathway with or without ADM. Results: Three hundred sixty-seven patients were analyzed. The average 2-year hospital direct cost per TE/I breast reconstruction patient was $11,862 in the +ADM and $12,319 in the −ADM groups (P > 0.05). Initial reconstructions were costlier in the +ADM ($6,868) than in the −ADM ($5,615) group, but the average cost of subsequent postreconstructive events within 2 years was significantly lower in +ADM ($5,176) than −ADM ($6,704) patients (P < 0.05). When a complication occurred, but reconstruction was still completed within 2 years, greater costs were incurred in the −ADM than in the +ADM group for most scenarios, leading to a net equalization of cost between study groups. Conclusion: Although direct hospital cost is an important factor for resource and fund allocation, it should not remain the sole factor when deciding to use ADM in TE/I reconstruction. PMID:27622099

  11. Preclinical and Preliminary Clinical Evaluation of Genetically Transduced Dermal Tissue Implants for the Sustained Secretion of Erythropoietin and Interferon α.

    PubMed

    Shapir, Nir; Miari, Reem; Blum, Shany; Schwartz, Doron; Chernin, Gil; Neil, Garry A; Afik, Daniel; Panet, Amos

    2015-12-01

    Protein drugs are currently delivered by bolus injection and although treatment frequently is successful, these methods also have major drawbacks, which call for the development of alternative technologies allowing prolonged delivery of these drugs. We developed a new ex vivo gene therapy platform called Transduced Autologous Restorative Gene Therapy (TARGT) for sustained long term production and secretion of autologous therapeutic proteins. A biopsy of dermal tissue taken from the patient is transduced ex vivo with a viral vector encoding the required gene under a constitutive promoter. Following measurement of protein secretion ex vivo, the transduced dermal tissue is implanted back into the patient, where it secretes the therapeutic protein into the circulation for several months or longer. A major hurdle to this approach is potential immunogenicity of the transduced tissue following implantation. In this paper we describe the preclinical and early clinical development of this technology, which allowed for overcoming these hurdles. To that end, we have used the helper dependent (HD) adenoviral vector with newly designed expression cassette containing genetic elements to optimize transgene expression. Moreover, we have developed procedures for TARGT tissue implantation, with measures to improve engraftment and reduce inflammation and rejection. Implantation of human TARGT to severe combined immune deficient (SCID) mice indicated long-term production of active proteins in the blood. Preliminary results of a clinical trial from two anemic end-stage renal disease patients, implanted with TARGTs expressing the human erythropoietin (EPO) gene, demonstrated prolonged secretion with physiologic blood level of the hormone and hemoglobin maintenance in the desired range, for a period of at least 5 months without exogenous EPO administration. We believe that the TARGT technology has the potential to become a platform for the sustained delivery of therapeutic proteins in

  12. A titanium surface with nano-ordered spikes and pores enhances human dermal fibroblastic extracellular matrix production and integration of collagen fibers.

    PubMed

    Yamada, Masahiro; Kato, Eiji; Yamamoto, Akiko; Sakurai, Kaoru

    2016-02-02

    The acquisition of substantial dermal sealing determines the prognosis of percutaneous titanium-based medical devices or prostheses. A nano-topographic titanium surface with ordered nano-spikes and pores has been shown to induce periodontal-like connective tissue attachment and activate gingival fibroblastic functions. This in vitro study aimed to determine whether an alkali-heat (AH) treatment-created nano-topographic titanium surface could enhance human dermal fibroblastic functions and binding strength to the deposited collagen on the titanium surface. The surface topographies of commercially pure titanium machined discs exposed to two different AH treatments were evaluated. Human dermal fibroblastic cultures grown on the discs were evaluated in terms of cellular morphology, proliferation, extracellular matrix (ECM) and proinflammatory cytokine synthesis, and physicochemical binding strength of surface-deposited collagen. An isotropically-patterned, shaggy nano-topography with a sponge-like inner network and numerous well-organized, anisotropically-patterned fine nano-spikes and pores were observed on each nano-topographic surface type via scanning electron microscopy. In contrast to the typical spindle-shaped cells on the machined surfaces, the isotropically- and anisotropically-patterned nano-topographic titanium surfaces had small circular/angular cells containing contractile ring-like structures and elongated, multi-shaped cells with a developed cytoskeletal network and multiple filopodia and lamellipodia, respectively. These nano-topographic surfaces enhanced dermal-related ECM synthesis at both the protein and gene levels, without proinflammatory cytokine synthesis or reduced proliferative activity. Deposited collagen fibers were included in these surfaces and sufficiently bound to the nano-topographies to resist the physical, enzymatic and chemical detachment treatments, in contrast to machined surfaces. Well-organized, isotropically

  13. Characterization of a non-fibrillar-related collagen in the mollusc Haliotis tuberculata and its biological activity on human dermal fibroblasts.

    PubMed

    Fleury, Christophe; Serpentini, Antoine; Kypriotou, Magdalini; Renard, Emmanuelle; Galéra, Philippe; Lebel, Jean-Marc

    2011-10-01

    In invertebrates, members of the collagen family have been found in various phyla. Surprisingly, in mollusc, little is known about such molecules. In this study, we characterize the full-length abalone type IV collagen and we analysed its biological effects on human fibroblast in order to gain insights about this molecule in molluscs and particularly clues about its roles. We screened a cDNA library of Haliotis tuberculata hemocytes. The expression pattern of the transcript is determined using real-time polymerase chain reaction and in situ hybridization. The close identity between α1(IV) C-terminal domain and the vertebrate homologue led us to produce, purify and test in vitro a recombinant protein corresponding to this region using human dermal fibroblasts cell culture. The biological effects were evaluated on proliferation and on differentiation. We found that the 5,334-bp open reading frame transcript encodes a protein of 1,777 amino acids, including an interrupted 1,502-residue collagenous domain and a 232-residue C-terminal non-collagenous domain. The expression pattern of this transcript is mainly found in the mantle and hemocytes. The recombinant protein corresponding α1(IV) C-terminal domain increased fibroblast proliferation by 69% and doubled collagen synthesis produced in primary cultures. This work provides the first complete primary structure of a mollusc non-fibrillar collagen chain and the biological effects of its C-terminal domain on human cells. In this study, we prove that the NC1 domain from a molluscan collagen can improve human fibroblast proliferation as well as differentiation.

  14. [Implantation of collagen coated hydroxyapatite particles. A clinical-histological study in humans].

    PubMed

    Sanz, M; Bascones, A; Kessler, A; García Nuñez, J; Newman, M G; Robertson, M A; Carranza, F A

    1989-05-01

    In this study, histologic behaviour of collagen coated hydroxylapatite particles implanted in human periodontal osseous defects has been analyzed. This material was surgically implanted in four patients, and reentry and block biopsies were carried out 4 and 6 months later. The histologic results demonstrate that this material is well tolerated by surrounding tissues, not eliciting an inflammatory reaction. At four months, the hydroxylapatite particles appear encapsulated by a very cellular connective tissue and at 6 months are found in direct contact with osteoid and mature bone. This material acts as a filler material, being fully biocompatible and stimulating an osseoconductive reaction of the adjacent alveolar bone. PMID:2637052

  15. [Implantation of collagen coated hydroxyapatite particles. A clinical-histological study in humans].

    PubMed

    Sanz, M; Bascones, A; Kessler, A; García Nuñez, J; Newman, M G; Robertson, M A; Carranza, F A

    1989-05-01

    In this study, histologic behaviour of collagen coated hydroxylapatite particles implanted in human periodontal osseous defects has been analyzed. This material was surgically implanted in four patients, and reentry and block biopsies were carried out 4 and 6 months later. The histologic results demonstrate that this material is well tolerated by surrounding tissues, not eliciting an inflammatory reaction. At four months, the hydroxylapatite particles appear encapsulated by a very cellular connective tissue and at 6 months are found in direct contact with osteoid and mature bone. This material acts as a filler material, being fully biocompatible and stimulating an osseoconductive reaction of the adjacent alveolar bone.

  16. Oriented collagen as a potential cochlear implant electrode surface coating to achieve directed neurite outgrowth.

    PubMed

    Volkenstein, Stefan; Kirkwood, John E; Lai, Edwina; Dazert, Stefan; Fuller, Gerald G; Heller, Stefan

    2012-04-01

    In patients with severe to profound hearing loss, cochlear implants (CIs) are currently the only therapeutic option when the amplification with conventional hearing aids does no longer lead to a useful hearing experience. Despite its great success, there are patients in which benefit from these devices is rather limited. One reason may be a poor neuron-device interaction, where the electric fields generated by the electrode array excite a wide range of tonotopically organized spiral ganglion neurons at the cost of spatial resolution. Coating of CI electrodes to provide a welcoming environment combined with suitable surface chemistry (e.g. with neurotrophic factors) has been suggested to create a closer bioelectrical interface between the electrode array and the target tissue, which might lead to better spatial resolution, better frequency discrimination, and ultimately may improve speech perception in patients. Here we investigate the use of a collagen surface with a cholesteric banding structure, whose orientation can be systemically controlled as a guiding structure for neurite outgrowth. We demonstrate that spiral ganglion neurons survive on collagen-coated surfaces and display a directed neurite growth influenced by the direction of collagen fibril deposition. The majority of neurites grow parallel to the orientation direction of the collagen. We suggest collagen coating as a possible future option in CI technology to direct neurite outgrowth and improve hearing results for affected patients.

  17. Enriched Astaxanthin Extract from Haematococcus pluvialis Augments Growth Factor Secretions to Increase Cell Proliferation and Induces MMP1 Degradation to Enhance Collagen Production in Human Dermal Fibroblasts

    PubMed Central

    Chou, Hsin-Yu; Lee, Chelsea; Pan, Jian-Liang; Wen, Zhi-Hong; Huang, Shu-Hung; Lan, Chi-Wei John; Liu, Wang-Ta; Hour, Tzyh-Chyuan; Hseu, You-Cheng; Hwang, Byeong Hee; Cheng, Kuo-Chen; Wang, Hui-Min David

    2016-01-01

    Among many antioxidants that are used for the repairing of oxidative stress induced skin damages, we identified the enriched astaxanthin extract (EAE) from Haematococcus pluvialis as a viable ingredient. EAE was extracted from the red microalgae through supercritical fluid carbon dioxide extraction. To compare the effectiveness, EAE wastreated on human dermal fibroblasts with other components, phorbol 12-myristate 13-acetate (PMA), and doxycycline. With sirius red staining and quantitative real-time polymerase chain reaction (qRT-PCR), we found that PMA decreased the collagen concentration and production while overall the addition of doxycycline and EAE increased the collagen concentration in a trial experiments. EAE increased collagen contents through inhibited MMP1 and MMP3 mRNA expression and induced TIMP1, the antagonists of MMPs protein, gene expression. As for when tested for various proteins through western blotting, it was seen that the addition of EAE increased the expression of certain proteins that promote cell proliferation. Testing those previous solutions using growth factor assay, it was noticeable that EAE had a positive impact on cell proliferation and vascular endothelial growth factor (VEGF) than doxycycline, indicating that it was a better alternative treatment for collagen production. To sum up, the data confirmed the possible applications as medical cosmetology agentsand food supplements. PMID:27322248

  18. Enriched Astaxanthin Extract from Haematococcus pluvialis Augments Growth Factor Secretions to Increase Cell Proliferation and Induces MMP1 Degradation to Enhance Collagen Production in Human Dermal Fibroblasts.

    PubMed

    Chou, Hsin-Yu; Lee, Chelsea; Pan, Jian-Liang; Wen, Zhi-Hong; Huang, Shu-Hung; Lan, Chi-Wei John; Liu, Wang-Ta; Hour, Tzyh-Chyuan; Hseu, You-Cheng; Hwang, Byeong Hee; Cheng, Kuo-Chen; Wang, Hui-Min David

    2016-01-01

    Among many antioxidants that are used for the repairing of oxidative stress induced skin damages, we identified the enriched astaxanthin extract (EAE) from Haematococcus pluvialis as a viable ingredient. EAE was extracted from the red microalgae through supercritical fluid carbon dioxide extraction. To compare the effectiveness, EAE wastreated on human dermal fibroblasts with other components, phorbol 12-myristate 13-acetate (PMA), and doxycycline. With sirius red staining and quantitative real-time polymerase chain reaction (qRT-PCR), we found that PMA decreased the collagen concentration and production while overall the addition of doxycycline and EAE increased the collagen concentration in a trial experiments. EAE increased collagen contents through inhibited MMP1 and MMP3 mRNA expression and induced TIMP1, the antagonists of MMPs protein, gene expression. As for when tested for various proteins through western blotting, it was seen that the addition of EAE increased the expression of certain proteins that promote cell proliferation. Testing those previous solutions using growth factor assay, it was noticeable that EAE had a positive impact on cell proliferation and vascular endothelial growth factor (VEGF) than doxycycline, indicating that it was a better alternative treatment for collagen production. To sum up, the data confirmed the possible applications as medical cosmetology agentsand food supplements. PMID:27322248

  19. Enriched Astaxanthin Extract from Haematococcus pluvialis Augments Growth Factor Secretions to Increase Cell Proliferation and Induces MMP1 Degradation to Enhance Collagen Production in Human Dermal Fibroblasts.

    PubMed

    Chou, Hsin-Yu; Lee, Chelsea; Pan, Jian-Liang; Wen, Zhi-Hong; Huang, Shu-Hung; Lan, Chi-Wei John; Liu, Wang-Ta; Hour, Tzyh-Chyuan; Hseu, You-Cheng; Hwang, Byeong Hee; Cheng, Kuo-Chen; Wang, Hui-Min David

    2016-06-16

    Among many antioxidants that are used for the repairing of oxidative stress induced skin damages, we identified the enriched astaxanthin extract (EAE) from Haematococcus pluvialis as a viable ingredient. EAE was extracted from the red microalgae through supercritical fluid carbon dioxide extraction. To compare the effectiveness, EAE wastreated on human dermal fibroblasts with other components, phorbol 12-myristate 13-acetate (PMA), and doxycycline. With sirius red staining and quantitative real-time polymerase chain reaction (qRT-PCR), we found that PMA decreased the collagen concentration and production while overall the addition of doxycycline and EAE increased the collagen concentration in a trial experiments. EAE increased collagen contents through inhibited MMP1 and MMP3 mRNA expression and induced TIMP1, the antagonists of MMPs protein, gene expression. As for when tested for various proteins through western blotting, it was seen that the addition of EAE increased the expression of certain proteins that promote cell proliferation. Testing those previous solutions using growth factor assay, it was noticeable that EAE had a positive impact on cell proliferation and vascular endothelial growth factor (VEGF) than doxycycline, indicating that it was a better alternative treatment for collagen production. To sum up, the data confirmed the possible applications as medical cosmetology agentsand food supplements.

  20. Percutaneous Implants with Porous Titanium Dermal Barriers: An In Vivo Evaluation of Infection Risk

    PubMed Central

    Isackson, Dorthyann; McGill, Lawrence D.; Bachus, Kent N.

    2010-01-01

    Osseointegrated percutaneous implants are a promising prosthetic alternative for a subset of amputees. However, as with all percutaneous implants, they have an increased risk of infection since they breach the skin barrier. Theoretically, host tissues could attach to the metal implant creating a barrier to infection. When compared with smooth surfaces, it is hypothesized that porous surfaces improve the attachment of the host tissues to the implant, and decrease the infection risk. In this study, 4 titanium implants, manufactured with a percutaneous post and a subcutaneous disk, were placed subcutaneously on the dorsum of eight New Zealand White rabbits. Beginning at four weeks post-op, the implants were inoculated weekly with 108 CFU Staphylococcus aureus until signs of clinical infection presented. While we were unable to detect a difference in the incidence of infection of the porous metal implants, smooth surface (no porous coating) percutaneous and subcutaneous components had a 7-fold increased risk of infection compared to the implants with a porous coating on one or both components. The porous coated implants displayed excellent tissue ingrowth into the porous structures; whereas, the smooth implants were surrounded with a thick, organized fibrotic capsule that was separated from the implant surface. This study suggests that porous coated metal percutaneous implants are at a significantly lower risk of infection when compared to smooth metal implants. The smooth surface percutaneous implants were inadequate in allowing a long-term seal to develop with the soft tissue, thus increasing vulnerability to the migration of infecting microorganisms. PMID:21145778

  1. Quantitative characterization of collagen in the fibrotic capsule surrounding implanted polymeric microparticles through second harmonic generation imaging

    DOE PAGESBeta

    Akilbekova, Dana; Bratlie, Kaitlin M.; Abraham, Thomas

    2015-06-30

    The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variationmore » in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively.« less

  2. Quantitative Characterization of Collagen in the Fibrotic Capsule Surrounding Implanted Polymeric Microparticles through Second Harmonic Generation Imaging

    PubMed Central

    Akilbekova, Dana; Bratlie, Kaitlin M.

    2015-01-01

    The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variation in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively. PMID:26125551

  3. Quantitative characterization of collagen in the fibrotic capsule surrounding implanted polymeric microparticles through second harmonic generation imaging

    SciTech Connect

    Akilbekova, Dana; Bratlie, Kaitlin M.; Abraham, Thomas

    2015-06-30

    The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variation in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively.

  4. Study of the porcine dermal collagen repair patch in morpho-functional recovery of the rotator cuff after minimum follow-up of 2.5 years.

    PubMed

    Giannotti, Stefano; Ghilardi, Marco; Dell'osso, Giacomo; Magistrelli, Luca; Bugelli, Giulia; Di Rollo, Frederica; Ricci, Giulia; Calabrese, Rosanna; Siciliano, Gabriele; Guido, Giulio

    2014-03-01

    Tendon augmentation grafts have the potential to facilitate the repair of massive or otherwise unrepairable rotator cuff tears. In our clinic, between 2009 and 2013, 25 patients underwent surgery to treat massive symptomatic rotator cuff tears with porcine dermal collagen patch. This study is a clinical and instrumental assessment of 9 patients with the longest follow-up. These patients were evaluated with Constant score, the American Shoulder and Elbow Surgeons Evaluation Form, ultrasound imaging, magnetic resonance imaging, and electromyography. The clinical evaluations have shown good outcomes. The magnetic resonance imaging results were comparable with those of the ultrasound scan. In all cases, we found covering of humeral head, centering of the humeral head, maintenance of the tropism of the supraspinatus, no appearance of fatty degeneration, no worse in cases with fatty degeneration. With the electromyographic examination a complete functional recovery was observed with the possibility of performing maximal contraction against resistance in all cases. We believe that porcine dermal collagen is effective as an augmentation graft in the treatment of chronic extensive rotator cuff tears, providing excellent pain relief with an improvement in active ranges of motion and strength. PMID:24526420

  5. Collagen fillers.

    PubMed

    Baumann, Leslie; Kaufman, Joely; Saghari, Sogol

    2006-01-01

    Collagen implants, both animal and human derived, have been used for soft tissue augmentation for many years. Bovine collagen fillers were the most popular injectable implants for nearly two decades in the United States. Since then, human bioengineered collagen products have been available in addition to hyaluronic acid-containing fillers. This article outlines the different types of injectable collagen implants, injection techniques, preferred methods of treatment, and possible adverse reactions to the injectable materials.

  6. An aqueous extract of the leaves of Chromolaena odorata (formerly Eupatorium odoratum) (Eupolin) inhibits hydrated collagen lattice contraction by normal human dermal fibroblasts.

    PubMed

    Phan, T T; Hughes, M A; Cherry, G W; Le, T T; Pham, H M

    1996-01-01

    Chromolaena odorata (formerly Eupatorium odoratum) is used as a traditional medicine in Vietnam (Nghiem, 1992), where its Vietnamese common name is "co hoi." While it has been widely considered a weed by agriculturalists (Holm et al., 1991), the aqueous extract and the decoction from the leaves of this plant have been used throughout Vietnam for the treatment of soft tissue wounds, burn wounds, and skin infections. A number of clinical studies done by Vietnamese as well as foreign medical workers has demonstrated the efficacy of this extract on the wound-healing process. In this article, the effect of the Eupolin extract on hydrated collagen lattice contraction by human dermal fibroblasts, an in vitro model of wound contraction, is described. The significant inhibition of collagen gel contraction by Eupolin extract at 50 to 200 micrograms/ml is demonstrated in various concentrations of collagen. When the extract at 50 to 150 micrograms/ml was washed out of the lattices and replaced by fresh medium without Eupolin, the contraction of collagen by cells was resumed. The visualization of cells in the lattices by incubation in a tetrazolium salt for 2 h showed live cells at 50 to 150 micrograms/ml of extract. In contrast, all cells were killed in the higher extract doses of 300 or 400 micrograms/ml. These preliminary results showing the inhibitory effect of Eupolin extract on collagen contraction suggest that a clinical evaluation of its effect on wound contraction and scar quality should be made. This work illustrates that traditional remedies that are used by folk practitioners to improve healing can be examined in a scientific manner using in vitro wound-healing models. It could be that the synergistic properties of components of the natural extract contribute to the positive effects demonstrated on various wound-healing mechanisms.

  7. Stable corneal regeneration four years after implantation of a cell-free recombinant human collagen scaffold.

    PubMed

    Fagerholm, Per; Lagali, Neil S; Ong, Jeb A; Merrett, Kimberley; Jackson, W Bruce; Polarek, James W; Suuronen, Erik J; Liu, Yuwen; Brunette, Isabelle; Griffith, May

    2014-03-01

    We developed cell-free implants, comprising carbodiimide crosslinked recombinant human collagen (RHC), to enable corneal regeneration by endogenous cell recruitment, to address the worldwide shortage of donor corneas. Patients were grafted with RHC implants. Over four years, the regenerated neo-corneas were stably integrated without rejection, without the long immunosuppression regime needed by donor cornea patients. There was no recruitment of inflammatory dendritic cells into the implant area, whereas, even with immunosuppression, donor cornea recipients showed dendritic cell migration into the central cornea and a rejection episode was observed. Regeneration as evidenced by continued nerve and stromal cell repopulation occurred over the four years to approximate the micro-architecture of healthy corneas. Histopathology of a regenerated, clear cornea from a regrafted patient showed normal corneal architecture. Donor human cornea grafted eyes had abnormally tortuous nerves and stromal cell death was found. Implanted patients had a 4-year average corrected visual acuity of 20/54 and gained more than 5 Snellen lines of vision on an eye chart. The visual acuity can be improved with more robust materials for better shape retention. Nevertheless, these RHC implants can achieve stable regeneration and therefore, represent a potentially safe alternative to donor organ transplantation.

  8. Role of xenogenous bovine platelet gel embedded within collagen implant on tendon healing: an in vitro and in vivo study

    PubMed Central

    Oryan, Ahmad; Meimandi-Parizi, Abdolhamid; Maffulli, Nicola

    2015-01-01

    Surgical reconstruction of large Achilles tendon defects is demanding. Platelet concentrates may be useful to favor healing in such conditions. The characteristics of bovine platelet-gel embedded within a collagen-implant were determined in vitro, and its healing efficacy was examined in a large Achilles tendon defect in rabbits. Two cm of the left Achilles tendon of 60 rabbits were excised, and the animals were randomly assigned to control (no implant), collagen-implant, or bovine-platelet-gel-collagen-implant groups. The tendon edges were maintained aligned using a Kessler suture. No implant was inserted in the control group. In the two other groups, a collagen-implant or bovine-platelet-gel-collagen-implant was inserted in the defect. The bioelectricity and serum platelet-derived growth factor levels were measured weekly and at 60 days post injury, respectively. After euthanasia at 60 days post injury, the tendons were tested at macroscopic, microscopic, and ultrastructural levels, and their dry matter and biomechanical performances were also assessed. Another 60 rabbits were assigned to receive no implant, a collagen-implant, or a bovine-platelet-gel-collagen-implant, euthanized at 10, 20, 30, and 40 days post injury, and their tendons were evaluated grossly and histologically to determine host-graft interactions. Compared to the control and collagen-implant, treatment with bovine-platelet-gel-collagen-implant improved tissue bioelectricity and serum platelet-derived growth factor levels, and increased cell proliferation, differentiation, and maturation. It also increased number, diameter, and density of the collagen fibrils, alignment and maturation of the collagen fibrils and fibers, biomechanical properties and dry matter content of the injured tendons at 60 days post injury. The bovine-platelet-gel-collagen-implant also increased biodegradability, biocompatibility, and tissue incorporation behavior of the implant compared to the collagen-implant alone

  9. Age-associated reduction of cellular spreading/mechanical force up-regulates matrix metalloproteinase-1 expression and collagen fibril fragmentation via c-Jun/AP-1 in human dermal fibroblasts.

    PubMed

    Qin, Zhaoping; Voorhees, John J; Fisher, Gary J; Quan, Taihao

    2014-12-01

    The dermal compartment of human skin is largely composed of dense collagen-rich fibrils, which provide structural and mechanical support. Skin dermal fibroblasts, the major collagen-producing cells, are interact with collagen fibrils to maintain cell spreading and mechanical force for function. A characteristic feature of aged human skin is fragmentation of collagen fibrils, which is initiated by matrix metalloproteinase 1 (MMP-1). Fragmentation impairs fibroblast attachment and thereby reduces spreading. Here, we investigated the relationship among fibroblast spreading, mechanical force, MMP-1 expression, and collagen fibril fragmentation. Reduced fibroblast spreading due to cytoskeletal disruption was associated with reduced cellular mechanical force, as determined by atomic force microscopy. These reductions substantially induced MMP-1 expression, which led to collagen fibril fragmentation and disorganization in three-dimensional collagen lattices. Constraining fibroblast size by culturing on slides coated with collagen micropatterns also significantly induced MMP-1 expression. Reduced spreading/mechanical force induced transcription factor c-Jun and its binding to a canonical AP-1 binding site in the MMP-1 proximal promoter. Blocking c-Jun function with dominant negative mutant c-Jun significantly reduced induction of MMP-1 expression in response to reduced spreading/mechanical force. Furthermore, restoration of fibroblast spreading/mechanical force led to decline of c-Jun and MMP-1 levels and eliminated collagen fibril fragmentation and disorganization. These data reveal a novel mechanism by which alteration of fibroblast shape/mechanical force regulates c-Jun/AP-1-dependent expression of MMP-1 and consequent collagen fibril fragmentation. This mechanism provides a foundation for understanding the cellular and molecular basis of age-related collagen fragmentation in human skin.

  10. In situ visualization of dermal collagen dynamics during skin burn healing using second-harmonic-generation microscopy

    NASA Astrophysics Data System (ADS)

    Yasui, Takeshi; Hase, Eiji; Tanaka, Ryosuke; Fukushima, Shu-ichiro; Araki, Tsutomu

    2015-06-01

    Burn healing is a process to repair thermally damaged tissues. Although burn healing has many aspects, it is common for dynamics of collagen fiber, such as decomposition, production, or growth, to be closely related with burn healing. If such healing process can be visualized from the viewpoint of the collagen dynamics, one may obtain new findings regarding biological repairing mechanisms in the healing process. To this end, second-harmonic-generation (SHG) light will be an effective optical probe because of high selectivity and good image contrast to collagen molecules as well as high spatial resolution, optical three-dimensional (3D) sectioning, minimal invasiveness, deep penetration, the absence of interference from background light, and in situ measurement without additional staining. Furthermore, since SHG light arises from a non-centrosymmetric triple helix of three polypeptide chains in the collagen molecule, its intensity decreases and finally disappears when thermal denaturation caused by the skin burn changes the structure of this molecule to a centrosymmetric random coil. Therefore, optical assessment of skin burn has been investigated by SHG microscopy. In this paper, we applied SHG microscopy for in situ imaging of the healing process in animal skin burn and successfully visualized the decomposition, production, and growth of renewal collagen fibers as a series of time-lapse images in the same subject.

  11. Surgical Therapy by Sandwich Transplantation using a Dermal Collagen-Elastin Matrix and Full Thickness Split Grafts and Gait Rehabilitation with Individualized Orthesis

    PubMed Central

    Wollina, Uwe; Heinig, Birgit

    2012-01-01

    Painful callosities of the feet (PCOF) are a rare complaint in children with severe impairment of mobility and quality of life. There is no medical treatment available. We investigated the usefulness of a recently developed combined transplant technique-the sandwich transplantation with dermal collagen-elastin template in this rare condition. A 14-year-old boy suffered from PCOF for several years without any improvement by topical therapy, dermabrasion, and oral retinoids. He was unable to walk normally and suffered from severe pain. We performed a complete deep excision of the hyperkeratotic plantar tissue in general anaesthesia in combination with sandwich transplantation in the same setting. Dry sheets of collagen-elastin matrix (1 mm thickness) were placed on the soft tissue defects and covered by full-thickness mesh graft transplants from the upper leg. An individualized orthosis was produced for gait rehabilitation. Two weeks after surgery the gait-related pain was reduced remarkably. Using the orthosis, the boy was able to walk pain-free even on staircase. Surgery of PCOF with sandwich transplantation and gait rehabilitation appears to be a promising strategy for this rare condition. PMID:23378711

  12. Noninvasive and High-Resolution Optical Monitoring of Healing of Diabetic Dermal Excisional Wounds Implanted with Biodegradable In Situ Gelable Hydrogels

    PubMed Central

    Yuan, Zhijia; Zakhaleva, Julia; Ren, Hugang; Liu, Jingxuan; Chen, Weiliam

    2010-01-01

    Closure of diabetic dermal chronic wounds remains a clinical challenge. Implant-assisted healing is emerging as a potential class of therapy for dermal wound closure; this advancement has not been paralleled by the development in complementary diagnostic techniques to objectively monitor the wound-healing process in conjunction with assessing/monitoring of implant efficacy. Biopsies provide the most objective morphological assessments of wound healing; however, they not only perpetuate the wound presence but also increase the risk of infection. A noninvasive and high-resolution imaging technique is highly desirable to provide objective longitudinal diagnosis of implant-assisted wound healing. We investigated the feasibility of deploying optical coherence tomography (OCT) for noninvasive monitoring of the healing of full-thickness excisional dermal wounds implanted with a novel in situ gelable hydrogel composed of N-carboxyethyl chitosan, oxidized dextran, and hyaluronan, in both normal and db/db mice. The results showed that OCT was able to differentiate the morphological differences (e.g., thickness of dermis) between normal and diabetic mice as validated by their corresponding histological evaluations (p < 0.05). OCT could detect essential morphological changes during wound healing, including re-epithelization, inflammatory response, and granulation tissue formation as well as impaired wound repair in diabetic mice. Importantly, by tracking specific morphological changes in hydrogel-assisted wound healing (e.g., implants' degradation and resorption, cell-mediated hydrogel degradation, and accelerated re-epithelization), OCT could also be deployed to monitor and evaluate the transformation of implanted biomaterials, thus holding the promise for noninvasive and objective monitoring of wound healing longitudinally and for objective efficacy assessment of implantable therapeutics in tissue engineering. PMID:19496703

  13. Clinical and radiographic evaluation of copolymerized Polylactic/polyglycolic acids as a bone filler in combination with a cellular dermal matrix graft around immediate implants

    PubMed Central

    Soliman, Mahitab M.; Zaki, Azza Abdulrahman; El Gazaerly, Hanaa Mohamed; Shemmrani, Ammar Al; Sorour, Abd El Latif

    2014-01-01

    Objective This study was conducted to evaluate clinically and radiographically the use of a cellular dermal matrix allograft (Alloderm) in combination with PLA/PGA (Fisiograft) around immediate implants. Materials and Methods Fourteen patients were included in this study, three patients received two implants, total of seventeen implants were placed. Periapical radiographs and orthopantomographs were taken. The selected teeth were extracted atraumatically after the reflection of full thickness flaps. One-piece Zimmer implants were placed immediately into the sockets. Weeks from implantation, radiographic evaluation was made at 6 Fisiograft in powder form was placed in the osseous defects around the implants. The implants were immediately restored with provisional crowns free from occlusion. Patients were clinically evaluated at 3, 6, and 14 months after loading which was done after 6 weeks from implantation. Radiographic evaluation was made at 6 and 14 months from implant placement. Results showed that immediate implantation was successful in sixteen out of seventeen implants, clinical parameters regarding plaque index, gingival index, there was a slight decrease through the follow-up periods from 3 to 14 months but it was non-significant, while there was a significant decrease in the probing depth. Radiographically there was a significant increase in the bone density from 6 to 14 months post loading, while the vertical bone defect was significantly decreased. The fisiograft functioned well as space maker and scaffolding material. The Alloderm performed well as a membrane to be used in association with immediate implants and it has a good potentiality for increasing the width of the keratinized gingiva, which is an important feature for implant esthetics. Conclusion the combination technique between the bone graft and the membrane proved to be successful to overcome dehiscence and osseous defects around immediate implants. PMID:25780357

  14. Clinical safety and efficacy of implantation of octacalcium phosphate collagen composites in tooth extraction sockets and cyst holes

    PubMed Central

    Kawai, Tadashi; Tanuma, Yuji; Matsui, Keiko; Suzuki, Osamu; Takahashi, Tetsu; Kamakura, Shinji

    2016-01-01

    It was demonstrated that octacalcium phosphate collagen composite achieved notable bone regeneration in bone defects in preclinical studies. On the basis of the research results, an investigator-initiated exploratory clinical trial was conducted after approval from a local Institutional Review Board. This clinical study was performed as a single-arm non-randomized intervention study. Octacalcium phosphate collagen composite was implanted into a total of 10 cases of alveolar bone defects after tooth extractions and cystectomy. Safety assessment was performed in terms of the clinical course and several consecutive laboratory examinations, and sequential radiographs were used for efficacy assessment. All participants uneventfully completed the clinical trial without major problems in their general condition. Postoperative wound swelling was observed, as also commonly seen in tooth extraction or cystectomy. Although no serious liver dysfunction, renal dysfunction, electrolyte imbalance, or abnormal urinalysis results were recognized, the number of white blood cells and C-reactive protein level temporarily increased after the operation. An increase in radiopacity in the octacalcium phosphate collagen composite–implanted site was observed in all cases. Finally, the border between the original bone and the octacalcium phosphate collagen composite–implanted site became indistinguishable. These results suggest that octacalcium phosphate collagen composite could be utilized safely in clinical situations in the future. PMID:27757220

  15. Administration of adipose-derived stem cells enhances vascularity, induces collagen deposition, and dermal adipogenesis in burn wounds.

    PubMed

    Bliley, Jacqueline M; Argenta, Anne; Satish, Latha; McLaughlin, Meghan M; Dees, Aaron; Tompkins-Rhoades, Casey; Marra, Kacey G; Rubin, J Peter

    2016-09-01

    Current treatment options for severe burn wounds are often insufficient in reconstructing skin and soft tissue defects. Adipose-derived stem cells (ASCs), a readily available source of multipotent stem cells, represent a promising therapy for the treatment of full-thickness burn wounds. Full-thickness burn wounds were created on the paraspinal region of athymic mice. A one-time, sub-eschar injection of 6.8×10(6) ASCs in PBS or PBS alone was administered at 24-h postoperatively. Time to healing was quantified using Image J analysis. At days 4, 7, 14, and 21, mice were sacrificed and tissues were excised for molecular and histological analysis. ASCs were able to survive in burn wounds as determined by the presence of PKH labeling and human PPARγ expression within the wounds. CD-31 staining demonstrated increased vascularity in ASC-treated wounds at POD 4 (p<0.05). Molecular studies showed enhanced adipogenesis, as well as type III and type I collagen deposition in the ASC treated group (p<0.05). An increase in the mRNA expression ratio of type III to type I collagen was also observed following ASC treatment (p<0.05). By enhancing vascularity, collagen deposition, and adipogenesis, ASCs show promise as an adjunctive therapy for the current treatment of full thickness burn wounds.

  16. The effect on bone growth enhancement of implant coatings with hydroxyapatite and collagen deposited electrochemically and by plasma spray.

    PubMed

    Daugaard, Henrik; Elmengaard, Brian; Bechtold, Joan E; Jensen, Thomas; Soballe, Kjeld

    2010-03-01

    Skeletal bone consists of hydroxyapatite (HA) [Ca(10)(PO(4))(6)(OH)(2)] and collagen type I, both of which are osseoconductive. The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable long-lasting fixation between bone and an implant surface. In this study, we evaluated the mechanical fixation and tissue distribution surrounding implants coated with three surfaces: plasma-sprayed HA coating, thinner coating of electrochemical-assisted deposition of HA, and an identical thin coating with a top layer of mineralized collagen. Uncoated plasma-sprayed titanium (Ti-6Al-4V) served as negative control. The electrochemical-assisted deposition was performed near physiological conditions. We used a canine experimental joint replacement model with four cylindrical implants (one of each treatment group) inserted in the humeri cancellous metaphyseal bone in a 1 mm gap. Observation time was 4 weeks. The mechanical fixation was quantified by push-out test to failure, and the peri-implant tissue formation by histomorphometric evaluation. HA coatings deposited by plasma spray technique or electrochemically, increased the mechanical fixation and bone ongrowth, but there was no statistical difference between the individual HA applications. Addition of collagen to the mineralized phase of the coating to create a more bone natural surface did not improve the osseoconductive effect of HA.

  17. Autologous implantation of BMP2-expressing dermal fibroblasts to improve bone mineral density and architecture in rabbit long bones.

    PubMed

    Ishihara, Akikazu; Weisbrode, Steve E; Bertone, Alicia L

    2015-10-01

    Cell-mediated gene therapy may treat bone fragility disorders. Dermal fibroblasts (DFb) may be an alternative cell source to stem cells for orthopedic gene therapy because of their rapid cell yield and excellent plasticity with bone morphogenetic protein-2 (BMP2) gene transduction. Autologous DFb or BMP2-expressing autologous DFb were administered in twelve rabbits by two delivery routes; a transcortical intra-medullar infusion into tibiae and delayed intra-osseous injection into femoral drill defects. Both delivery methods of DFb-BMP2 resulted in a successful cell engraftment, increased bone volume, bone mineral density, improved trabecular bone microarchitecture, greater bone defect filling, external callus formation, and trabecular surface area, compared to non-transduced DFb or no cells. Cell engraftment within trabecular bone and bone marrow tissue was most efficiently achieved by intra-osseous injection of DFb-BMP2. Our results suggested that BMP2-expressing autologous DFb have enhanced efficiency of engraftment in target bones resulting in a measurable biologic response by the bone of improved bone mineral density and bone microarchitecture. These results support that autologous implantation of DFb-BMP2 warrants further study on animal models of bone fragility disorders, such as osteogenesis imperfecta and osteoporosis to potentially enhance bone quality, particularly along with other gene modification of these diseases.

  18. A light and electron microscopic evaluation of Zyderm collagen and Zyplast implants in aging human facial skin. A pilot study.

    PubMed

    Stegman, S J; Chu, S; Bensch, K; Armstrong, R

    1987-12-01

    Four patients received Zyderm collagen implant (ZCI) or Zyplast implant (ZI) in preauricular and infraauricular regions of facial skin periodically between one and nine months. Both materials were identified microscopically in the mid- to deep dermis at all points of the study and, in 60% to 70% of the injected sites, some material was also present subdermally. A slow, gradual colonization of ZCI by fibroblasts was noted compared with a delayed intense interaction of these cells with ZI. Also, there was some new collagen deposition associated with remodeling of the ZI, while no demonstrable synthetic activity occurred in relationship to ZCI. The results suggest that ZCI and ZI "migrate" deeper and eventually move into the subcutaneous plane. This movement could explain the loss of correction at six to nine months that is noted when this implant is used for age-related changes.

  19. Ex vivo and in vivo second-harmonic-generation imaging of dermal collagen fiber in skin: comparison of imaging characteristics between mode-locked Cr:forsterite and Ti:sapphire lasers.

    PubMed

    Yasui, Takeshi; Takahashi, Yu; Ito, Masahiro; Fukushima, Shuichiro; Araki, Tsutomu

    2009-04-01

    Second-harmonic-generation (SHG) microscopy is an interesting new tool for observing dermal collagen fiber in skin. However, conventional SHG microscopy using a mode-locked Ti:sapphire laser suffers from low penetration depth and a slow image acquisition rate caused by scattering and absorption in tissue, making it difficult to use for in vivo applications on human skin. We develop an SHG microscope equipped with a mode-locked Cr:forsterite laser with a long wavelength and compare its imaging characteristics with that of a Ti:sapphire-laser-based SHG microscope for the measurement of dermal collagen fiber in animal and human skins. The results indicate the suitability of the Cr:forsterite laser-based SHG microscope for in vivo imaging of human skin.

  20. Effects of implanting ram and wether lambs with zeranol at birth and weaning on palatability and muscle collagen characteristics.

    PubMed

    Nold, R A; Unruh, J A; Hunt, M C; Spaeth, C W

    1992-09-01

    Thirty-five zeranol-implanted (I) and nonimplanted (NI) ram and wether lambs representing four treatments (implanted rams [IR], nonimplanted rams [NIR], implanted wethers [IW], and nonimplanted wethers [NIW]) were evaluated for meat palatability and muscle collagen characteristics. Rib (longissimus muscle, LM) chops from I lambs were juicier (P less than .05) than rib chops from NI lambs. Chops from IR lambs had more (P less than .05) detectable connective tissue and lower myofibrillar and overall tenderness scores than chops from NIR, IW, or NIW lambs. Warner-Bratzler shear (WBS) values tended to be higher (P = .06) for LM chops from rams than for those from wethers, but WBS values for Biceps femoris (BF) chops were similar (P greater than .05) for rams and wethers. Implanting did not affect (P greater than .05) WBS values. Rams had more (P less than .05) LM heat-labile (soluble, SC), nonheat-labile (insoluble, IC), and total collagen (TC) and a higher (P less than .05) percentage of SC (SC/TC) than did wethers. Soluble collagen, TC, and percentage of SC for the BF were higher (P less than .05) and IC tended (P = .09) to be higher in chops from rams than in those from wethers. Implanting did not affect (P greater than .05) collagen amount or solubility. Serum nonprotein hydroxyproline (NPHP) was higher (P less than .05) in rams than in wethers throughout the feeding period and tended (P = .05) to be higher at slaughter. Implanting did not affect (P greater than .05) serum NPHP.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Collagen implant with gentamicin sulphate as an option to treat a neuroischaemic diabetic foot ulcer: Case report

    PubMed Central

    Costa Almeida, C.E.

    2016-01-01

    Introduction The ischaemic diabetic foot is associated with a faster evolving atherosclerosis affecting preferentially the bellow knee arteries. This distal ischemia associated with a wide distribution of multiple stenosis and occlusions throughout lower limb arteries, makes revascularization very hard or even impossible. This represents a major factor responsible for non-healing diabetic foot ulcer. In these cases all efforts should be made to find treatment alternatives that can promote ulcer healing. Case presentation Male patient with neuroischaemic diabetic foot ulcer with exposure tendon, without possibility for endovascular or surgical revascularization, was treated unsuccessfully with prostaglandin and several types of dressings for 7 months. Skin graft failed. Weekly dressings with collagen implant impregnated with gentamicin sulphate were then started and continued in an outpatient setting. Evolution was very positive, with 99% of epithelisation in 9 months. No pain or infection since the beginning of this treatment. Discussion Successful treatment of a neuroischaemic diabetic foot ulcer rests with the possibility of increasing the perfusion to the foot. Whether or not a revascularization procedure is possible will set the tone for the ensuing treatment. Using collagen implant with gentamicin sulphate, collagen is delivered to the wound bed helping in the granulation tissue formation, will increase microcirculation, and topic gentamicin will decrease bacterial load, exudate and proteases production, increasing cicatrisation. Conclusion In neuroischaemic diabetic foot ulcer weekly dressings with collagen implant impregnated with gentamicin sulphate can be a good option for ulcer healing. PMID:26927956

  2. Attachment of an aminoglycoside, amikacin, to implantable collagen for local delivery in wounds.

    PubMed Central

    Boyce, S T; Supp, A P; Warden, G D; Holder, I A

    1993-01-01

    Cultured skin substitutes consisting of implantable collagen (COL) and cultured human skin cells often fail clinically from destruction by microbial contamination. Hypothetically, addition of selected antimicrobial drugs to the implant may control microbial contamination and increase healing of skin wounds with these materials. As a model for drug delivery, bovine skin COL (1 mg/ml) and amikacin (AM; 46 micrograms/ml) were modified by covalent addition of biotin (B-COL and B-AM, respectively) from B-N-hydroxysuccinimide and bound together noncovalently with avidin (A). B-COL was incubated with A and then with B-peroxidase (B-P) or by serial incubation with B-AM and B-P, before P-dependent chromogen formation. Colorimetric data (n = 12 per condition) from spot tests on nitrocellulose paper were collected by transmission spectrophotometry. Specificity of drug binding in spot tests was determined by (i) serial dilution of B-COL; (ii) reactions with COL, AM, or P that had no B; (iii) removal of A; or (iv) preincubation of B-COL-A with B before incubation with B-P. Binding of B-AM was (i) dependent on the concentration of B-COL; (ii) specific to B-COL, A, and B-P (P < 0.05); and (iii) not eluted by incubation in 0.15 or 1.0 M NaCl. B-AM was found to block binding of B-P to the B-COL-A complex and to retain bacteriocidal activity against 10 clinical isolates of wound bacteria in the wet disc assay. Antimicrobial activity of B-AM was removed from solution by treatment with magnetic A and a permanent magnet. These results suggest that selected antimicrobial drugs can be biotinylated for attachments to COL-cultured cell implants without loss of pharmacologic activity. Because this chemistry utilizes a common ligand, any molar ratio of agents may be administered simultaneously and localized to the site of implantation. Images PMID:8239602

  3. Altered spatiotemporal expression of collagen types I, III, IV, and VI in Lpar3-deficient peri-implantation mouse uterus.

    PubMed

    Diao, Honglu; Aplin, John D; Xiao, Shuo; Chun, Jerold; Li, Zuguo; Chen, Shiyou; Ye, Xiaoqin

    2011-02-01

    Lpar3 is upregulated in the preimplantation uterus, and deletion of Lpar3 leads to delayed uterine receptivity in mice. Microarray analysis revealed that there was higher expression of Col3a1 and Col6a3 in the Preimplantation Day 3.5 Lpar3(-/-) uterus compared to Day 3.5 wild-type (WT) uterus. Since extracellular matrix (ECM) remodeling is indispensable during embryo implantation, and dynamic spatiotemporal alteration of specific collagen types is part of this process, this study aimed to characterize the expression of four main uterine collagen types: fibril-forming collagen (COL) I and COL III, basement membrane COL IV, and microfibrillar COL VI in the peri-implantation WT and Lpar3(-/-) uterus. An observed delay of COL III and COL VI clearance in the Lpar3(-/-) uterus may be associated with higher preimplantation expression of Col3a1 and Col6a3. There was also delayed clearance of COL I and delayed deposition of COL IV in the decidual zone in the Lpar3(-/-) uterus. These changes were different from the effects of 17beta-estradiol and progesterone on uterine collagen expression in ovariectomized WT uterus, indicating that the altered collagen expression in Lpar3(-/-) uterus is unlikely to be a result of alterations in ovarian hormones. Decreased expression of several genes encoding matrix-degrading metallo- and serine proteinases was observed in the Lpar3(-/-) uterus. These results demonstrate that pathways downstream of LPA3 are involved in the dynamic remodeling of ECM in the peri-implantation uterus.

  4. Dynamic mechanical characterization of a mutable collagenous tissue: response of sea cucumber dermis to cell lysis and dermal extracts.

    PubMed

    Szulgit, G K; Shadwick, R E

    2000-05-01

    The dermis of the holothurian Cucumaria frondosa is a mutable collagenous tissue (MCT). In this study, the inner and outer regions of the dermis were separated and used to make two different tissue extracts. These extracts were applied to intact pieces of dermis, one invoking a stiff mechanical state and the other invoking a compliant state. The extracts were effective on tissues incubated in artificial sea water (ASW) and in those incubated in Ca(2+)-chelated ASW. Furthermore, the extracts were effective on both fresh tissues and tissues in which the cells had been lysed by freeze-thawing, indicating that the sites of action are in the extracellular matrix. Dynamic oscillatory shear tests and analyses were used to measure both the dynamic shear stiffness (G*) and the relative damping (tan delta ) of the tissue. These two parameters proved to be inversely related to each other (i.e. when G* increased, tan delta decreased). A theoretical viscoelastic model is constructed to interpret the results of these tests. It is concluded that changes in the mechanical state of the tissue involve interactions between elastic elements within the tissue rather than an alteration of its viscous components.

  5. Development of a cultured dermal substitute composed of a spongy matrix of hyaluronic acid and atelo-collagen combined with fibroblasts: cryopreservation.

    PubMed

    Kubo, Kentaro; Kuroyanagi, Yoshimitsu

    2004-02-01

    An allogeneic cultured dermal substitute (CDS) was prepared by cultivating fibroblasts on a two-layered spongy matrix of hyaluronic acid (HA) and atelo-collagen (Col). The ability of fibroblasts to secrete cytokines is dependent on the conditions of freezing and thawing. The first experiment was designed to investigate the effects of supplements in a cryoprotective medium, that is, dimethylsulfoxide (DMSO), glycerol, and fetal bovine serum (FBS). In each experiment we measured the cell viability after thawing and the cell growth in CDS recultured after thawing. In addition, the amount of vascular endothelial growth factor (VEGF) released from the CDS recultured for one week after thawing was measured. The highest values of cell viability, cell growth, and the amount of VEGF released were obtained when CDS was frozen in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% DMSO and 40% FBS, and then thawed quickly in a water bath at 37 degrees C. However, due to the high cost of FBS, in clinical applications CDS is usually frozen in DMEM supplemented with 10% DMSO and 20% FBS. In practice, however, physicians often cannot use CDS immediately after thawing, depending on clinical conditions. Therefore, in the second experiment we investigated cell viability at different time points after thawing. In addition, we investigated cell growth and the amount of VEGF released from fibroblasts in CDS at different time points after thawing under different conditions, and after further reculturing for one week. We recommend that CDS be rinsed with lactated Ringer's solution immediately after thawing, and that it be used within 4 h after thawing. PMID:14961958

  6. Natural flexible dermal armor.

    PubMed

    Yang, Wen; Chen, Irene H; Gludovatz, Bernd; Zimmermann, Elizabeth A; Ritchie, Robert O; Meyers, Marc A

    2013-01-01

    Fish, reptiles, and mammals can possess flexible dermal armor for protection. Here we seek to find the means by which Nature derives its protection by examining the scales from several fish (Atractosteus spatula, Arapaima gigas, Polypterus senegalus, Morone saxatilis, Cyprinius carpio), and osteoderms from armadillos, alligators, and leatherback turtles. Dermal armor has clearly been developed by convergent evolution in these different species. In general, it has a hierarchical structure with collagen fibers joining more rigid units (scales or osteoderms), thereby increasing flexibility without significantly sacrificing strength, in contrast to rigid monolithic mineral composites. These dermal structures are also multifunctional, with hydrodynamic drag (in fish), coloration for camouflage or intraspecies recognition, temperature and fluid regulation being other important functions. The understanding of such flexible dermal armor is important as it may provide a basis for new synthetic, yet bioinspired, armor materials. PMID:23161399

  7. Flexible Dermal Armor in Nature

    NASA Astrophysics Data System (ADS)

    Yang, Wen; Chen, Irene H.; Mckittrick, Joanna; Meyers, Marc A.

    2012-04-01

    Many animals possess dermal armor, which acts primarily as protection against predators. We illustrate this through examples from both our research and the literature: alligator, fish (alligator gar, arapaima, and Senegal bichir), armadillo, leatherback turtle, and a lizard, the Gila monster. The dermal armor in these animals is flexible and has a hierarchical structure with collagen fibers joining mineralized units (scales, tiles, or plates). This combination significantly increases the strength and flexibility in comparison with a simple monolithic mineral composite or rigid dermal armor. This dermal armor is being studied for future bioinspired armor applications providing increased mobility.

  8. Mineralization of alkaline phosphatase-complexed collagen implants in the rat in relation to serum inorganic phosphate.

    PubMed

    van den Bos, T; Oosting, J; Everts, V; Beertsen, W

    1995-04-01

    The present study was designed to determine the relationship between mineralization of collagenous matrices and serum levels of calcium and inorganic phosphate. Collagen slices were prepared from bovine dentin or cortical bone and complexed with varying amounts of intestinal alkaline phosphatase (ALP). The enzyme was added to induce de novo mineralization. The ALP-complexed slices were implanted subcutaneously over the skull and in the dorsolateral aspect of the abdominal wall in female Wistar rats of various ages (5-, 10-, 20-, or 35-week-old) and in young male rats fed on a low-P diet. After 1-4 weeks, the implants were removed and analyzed for calcium and phosphate content. In addition, serum levels of calcium and phosphate (total and inorganic) were determined. It was shown that the highest mineral influx occurred in the younger rats (which were also highest in serum P(i)), whereas almost no mineral uptake occurred in the older ones. Also in rats fed on a low-P diet (which were low in serum P(i), a strongly decreased mineral influx was noted. In all animal groups a positive correlation was found between the degree of mineralization and serum P(i). No distinct relationship was found between serum Ca/organic phosphate levels and mineral influx in the implants. In vitro incubation of ALP-collagen conjugates in serum from younger and older rats confirmed our view that serum P(i), besides local levels of ALP, is important in de novo mineral deposition. For accretion of mineral in partially remineralized collagenous carriers, ALP activity was not required.

  9. Role of topical application of gentamicin containing collagen implants in cardiac surgery.

    PubMed

    Mishra, Pankaj Kumar; Ashoub, Ahmed; Salhiyyah, Kareem; Aktuerk, Dincer; Ohri, Sunil; Raja, Shahzad G; Luckraz, Heyman

    2014-07-08

    Sternal wound infections (SWI) continue to be a major cause of concern after cardiac surgery. It leads to prolonged hospital stay and increased morbidity, mortality and increased hospital costs. Prophylactic systemic antibiotics have been used to prevent surgical site infection (SSI). However, prolonged postoperative use of systemic antibiotics can lead to emergence of resistant organisms. Gentamycin Containing Collagen Implants (GCCI) when used during sternotomy closure produces high local antibiotic concentrations in the wound with a low serum concentration. There is evidence that the concentration of gentamicin in the mediastinal fluid reaches levels high enough to be effective against bacteria that are considered resistant to gentamycin and other antibiotics.However, questions have been raised about the safety and efficacy of GCCI. There were concerns whether GCCI can lead to systemic absorption with renal impairment and whether use of topical antibiotics can lead to emergence of antimicrobial resistance.We, hereby, review the literature on GCCI (Collatamp) and take the opportunity to appraise the scientific community about their role in cardiac surgery. Several recent studies have supported their clinical effectiveness. They should be used in dry condition and should not be soaked in saline even for a short period prior to use. However, for GCCI to become part of routine practice in cardiac surgery further large randomised studies are required. As the incidence of sternal wound infection is low in the specialty of cardiac surgery, for any study to be sufficiently powered to address this issue, multicenter studies might be the way forward.Based on the evidence presented in this manuscript it is recommended GCCI (Collatamp) can be a cost effective adjunct for prevention of sternal wound infection. They can also be used for treatment of Deep Sternal Wound Infection.

  10. Role of topical application of gentamicin containing collagen implants in cardiac surgery

    PubMed Central

    2014-01-01

    Sternal wound infections (SWI) continue to be a major cause of concern after cardiac surgery. It leads to prolonged hospital stay and increased morbidity, mortality and increased hospital costs. Prophylactic systemic antibiotics have been used to prevent surgical site infection (SSI). However, prolonged postoperative use of systemic antibiotics can lead to emergence of resistant organisms. Gentamycin Containing Collagen Implants (GCCI) when used during sternotomy closure produces high local antibiotic concentrations in the wound with a low serum concentration. There is evidence that the concentration of gentamicin in the mediastinal fluid reaches levels high enough to be effective against bacteria that are considered resistant to gentamycin and other antibiotics. However, questions have been raised about the safety and efficacy of GCCI. There were concerns whether GCCI can lead to systemic absorption with renal impairment and whether use of topical antibiotics can lead to emergence of antimicrobial resistance. We, hereby, review the literature on GCCI (Collatamp) and take the opportunity to appraise the scientific community about their role in cardiac surgery. Several recent studies have supported their clinical effectiveness. They should be used in dry condition and should not be soaked in saline even for a short period prior to use. However, for GCCI to become part of routine practice in cardiac surgery further large randomised studies are required. As the incidence of sternal wound infection is low in the specialty of cardiac surgery, for any study to be sufficiently powered to address this issue, multicenter studies might be the way forward. Based on the evidence presented in this manuscript it is recommended GCCI (Collatamp) can be a cost effective adjunct for prevention of sternal wound infection. They can also be used for treatment of Deep Sternal Wound Infection. PMID:25005533

  11. Arthroscopic Implantation of a Bio-Inductive Collagen Scaffold for Treatment of an Articular-Sided Partial Rotator Cuff Tear

    PubMed Central

    Ryu, Richard K.N.; Ryu, Jessica H.J.; Abrams, Jeffrey S.; Savoie, Felix H.

    2015-01-01

    The treatment of articular-sided partial rotator cuff tears remains a challenge to the treating orthopaedic surgeon. Treatment algorithms have included nonoperative management, debridement alone, and debridement and subacromial decompression, as well as articular-sided rotator cuff repair and completion of the tear on the bursal side followed by a traditional arthroscopic rotator cuff repair. Implantation of a bio-inductive collagen scaffold on the bursal side of the rotator cuff to potentially heal an articular-sided tear represents a novel approach to this difficult clinical entity. PMID:26697308

  12. Characterization and evolution of dermal filaments from patients with Morgellons disease.

    PubMed

    Middelveen, Marianne J; Mayne, Peter J; Kahn, Douglas G; Stricker, Raphael B

    2013-01-01

    Morgellons disease is an emerging skin disease characterized by formation of dermal filaments associated with multisystemic symptoms and tick-borne illness. Some clinicians hypothesize that these often colorful dermal filaments are textile fibers, either self-implanted by patients or accidentally adhering to lesions, and conclude that patients with this disease have delusions of infestation. We present histological observations and electron microscopic imaging from representative Morgellons disease samples revealing that dermal filaments in these cases are keratin and collagen in composition and result from proliferation and activation of keratinocytes and fibroblasts in the epidermis. Spirochetes were detected in the dermatological specimens from our study patients, providing evidence that Morgellons disease is associated with an infectious process. PMID:23326202

  13. Breakthroughs in US dermal fillers for facial soft-tissue augmentation.

    PubMed

    Goldberg, David J

    2009-12-01

    Over the last 20 years, developments in injectable dermal fillers have led to a revolution in facial soft-tissue augmentation. The demand for dermal fillers for facial soft-tissue augmentation procedures has increased due in part to the less invasive nature of these products compared with surgical procedures. Available options in the United States have expanded from autologous tissues and animal-derived collagens to bacterially fermented biopolymers and synthetic implants. Beyond their physical composition, currently available products are further differentiated by their recommended depth of injection, suitability for different facial areas, and duration of aesthetic improvement. While older dermal fillers rely on the integrity of the injected material to achieve their clinical effects, some newer products are postulated to act by stimulating the patient's own biological and cellular processes. This article examines breakthroughs in facial soft-tissue augmentation that have expanded the palette of options available to physicians.

  14. Characterization and evolution of dermal filaments from patients with Morgellons disease.

    PubMed

    Middelveen, Marianne J; Mayne, Peter J; Kahn, Douglas G; Stricker, Raphael B

    2013-01-01

    Morgellons disease is an emerging skin disease characterized by formation of dermal filaments associated with multisystemic symptoms and tick-borne illness. Some clinicians hypothesize that these often colorful dermal filaments are textile fibers, either self-implanted by patients or accidentally adhering to lesions, and conclude that patients with this disease have delusions of infestation. We present histological observations and electron microscopic imaging from representative Morgellons disease samples revealing that dermal filaments in these cases are keratin and collagen in composition and result from proliferation and activation of keratinocytes and fibroblasts in the epidermis. Spirochetes were detected in the dermatological specimens from our study patients, providing evidence that Morgellons disease is associated with an infectious process.

  15. Characterization and evolution of dermal filaments from patients with Morgellons disease

    PubMed Central

    Middelveen, Marianne J; Mayne, Peter J; Kahn, Douglas G; Stricker, Raphael B

    2013-01-01

    Morgellons disease is an emerging skin disease characterized by formation of dermal filaments associated with multisystemic symptoms and tick-borne illness. Some clinicians hypothesize that these often colorful dermal filaments are textile fibers, either self-implanted by patients or accidentally adhering to lesions, and conclude that patients with this disease have delusions of infestation. We present histological observations and electron microscopic imaging from representative Morgellons disease samples revealing that dermal filaments in these cases are keratin and collagen in composition and result from proliferation and activation of keratinocytes and fibroblasts in the epidermis. Spirochetes were detected in the dermatological specimens from our study patients, providing evidence that Morgellons disease is associated with an infectious process. PMID:23326202

  16. Keloid-derived, plasma/fibrin-based skin equivalents generate de novo dermal and epidermal pathology of keloid fibrosis in a mouse model.

    PubMed

    Lee, Yun-Shain; Hsu, Tim; Chiu, Wei-Chih; Sarkozy, Heidi; Kulber, David A; Choi, Aaron; Kim, Elliot W; Benya, Paul D; Tuan, Tai-Lan

    2016-03-01

    Keloids are wounding-induced tumor-like human scars. Unclear etiology and lack of animal models to reveal disease mechanisms and invent therapies deepen the grievous health and psychosocial state of vulnerable individuals. Epitomizing the injury-repair environment which triggers and fosters keloid formation and essential dermal/epidermal interactions in disease development, the novel animal model was established by implanting porous polyethylene ring-supported plasma/fibrin-based epidermal-dermal skin constructs on the dorsum of athymic NU/J mice. The implants were stable to 18 weeks, contained abundant human cells, and remodeled to yield scar architecture characteristic of keloid fibrosis compared with normal implants and clinical specimens: (1) macroscopic convex or nodular scar morphology; (2) morphogenesis and accumulation of large collagen bundles from collagen-null initial constructs; (3) epidermal hyperplasia, aberrant epidermal-dermal patency, and features of EMT; (4) increased vasculature, macrophage influx, and aggregation; and (5) temporal-spatial increased collagen-inducing PAI-1 and its interactive partner uPAR expression. Development of such pathology in the NU/J host suggests that T-cell participation is less important at this stage than at keloid initiation. These accessible implants also healed secondary excisional wounds, enabling clinically relevant contemporaneous wounding and treatment strategies, and evaluation. The model provides a robust platform for studying keloid formation and testing knowledge-based therapies. PMID:26683740

  17. Beneficial regulation of fibrillar collagens, heat shock protein-47, elastin fiber components, transforming growth factor-β1, vascular endothelial growth factor and oxidative stress effects by copper in dermal fibroblasts.

    PubMed

    Philips, Neena; Samuel, Philips; Parakandi, Harit; Gopal, Sesha; Siomyk, Halyna; Ministro, Abraham; Thompson, Terrel; Borkow, Gadi

    2012-01-01

    Skin aging is associated with the loss of the structural collagens and the elastin fiber components that form the extracellular matrix (ECM). It is associated with reduced transforming growth factor-β (TGF-β), angiogenesis and increased oxidative stress. Copper has been incorporated into cosmetics for anti-skin aging. This research investigated the mechanism for the anti-skin aging effect copper ions, from cuprous oxide powders. Dermal fibroblasts were exposed to copper and examined for expression (protein and/or promoter levels) of types I, III, V collagen, heat shock protein-47 (HSP-47), elastin, fibrillin-1, and fibrillin-2, TGF-β1, vascular endothelial growth factor (VEGF), and in addition for membrane damage and lipid peroxidation. The direct antioxidant activity of copper was also determined. The research indicates that copper's anti-skin aging and skin regeneration potential is through its stimulation of ECM proteins, TGF-β1, VEGF, and inhibition of oxidative stress effects at physiological concentrations; and supports its use in cosmetics. PMID:22324999

  18. In vivo observation of age-related structural changes of dermal collagen in human facial skin using collagen-sensitive second harmonic generation microscope equipped with 1250-nm mode-locked Cr:Forsterite laser

    NASA Astrophysics Data System (ADS)

    Yasui, Takeshi; Yonetsu, Makoto; Tanaka, Ryosuke; Tanaka, Yuji; Fukushima, Shu-ichiro; Yamashita, Toyonobu; Ogura, Yuki; Hirao, Tetsuji; Murota, Hiroyuki; Araki, Tsutomu

    2013-03-01

    In vivo visualization of human skin aging is demonstrated using a Cr:Forsterite (Cr:F) laser-based, collagen-sensitive second harmonic generation (SHG) microscope. The deep penetration into human skin, as well as the specific sensitivity to collagen molecules, achieved by this microscope enables us to clearly visualize age-related structural changes of collagen fiber in the reticular dermis. Here we investigated intrinsic aging and/or photoaging in the male facial skin. Young subjects show dense distributions of thin collagen fibers, whereas elderly subjects show coarse distributions of thick collagen fibers. Furthermore, a comparison of SHG images between young and elderly subjects with and without a recent life history of excessive sun exposure show that a combination of photoaging with intrinsic aging significantly accelerates skin aging. We also perform image analysis based on two-dimensional Fourier transformation of the SHG images and extracted an aging parameter for human skin. The in vivo collagen-sensitive SHG microscope will be a powerful tool in fields such as cosmeceutical sciences and anti-aging dermatology.

  19. In vivo observation of age-related structural changes of dermal collagen in human facial skin using collagen-sensitive second harmonic generation microscope equipped with 1250-nm mode-locked Cr:Forsterite laser.

    PubMed

    Yasui, Takeshi; Yonetsu, Makoto; Tanaka, Ryosuke; Tanaka, Yuji; Fukushima, Shu-ichiro; Yamashita, Toyonobu; Ogura, Yuki; Hirao, Tetsuji; Murota, Hiroyuki; Araki, Tsutomu

    2013-03-01

    In vivo visualization of human skin aging is demonstrated using a Cr:Forsterite (Cr:F) laser-based, collagen-sensitive second harmonic generation (SHG) microscope. The deep penetration into human skin, as well as the specific sensitivity to collagen molecules, achieved by this microscope enables us to clearly visualize age-related structural changes of collagen fiber in the reticular dermis. Here we investigated intrinsic aging and/or photoaging in the male facial skin. Young subjects show dense distributions of thin collagen fibers, whereas elderly subjects show coarse distributions of thick collagen fibers. Furthermore, a comparison of SHG images between young and elderly subjects with and without a recent life history of excessive sun exposure show that a combination of photoaging with intrinsic aging significantly accelerates skin aging. We also perform image analysis based on two-dimensional Fourier transformation of the SHG images and extracted an aging parameter for human skin. The in vivo collagen-sensitive SHG microscope will be a powerful tool in fields such as cosmeceutical sciences and anti-aging dermatology. PMID:23212157

  20. Preliminary investigation of a biological augmentation of rotator cuff repairs using a collagen implant: a 2-year MRI follow-up

    PubMed Central

    Bokor, Desmond John; Sonnabend, David; Deady, Luke; Cass, Ben; Young, Allan; Van Kampen, Craig; Arnoczky, Steven

    2015-01-01

    Summary Background the inability to restore the normal tendon footprint and limit strains on the repair site are thought to contribute to re-tearing following rotator cuff repair. The purpose of this study was to use a collagen implant to augment rotator cuff repairs through the restoration of the native tendon footprint and the induction of new tissue to decrease overall tendon strain. Methods repairs of full-thickness rotator cuff lesions in 9 adult patients were augmented with a novel collagen implant placed over the bursal surface of the repair. Tendon thickness and footprint anatomy were evaluated using MRI at 3, 6, 12, and 24 months. Clinical results were assessed using standard outcome metrics. Mean follow-up for all patients was 25.8 months. Results the implant induced significant new tissue formation in all patients by 3 months. This tissue matured over time and became indistinguishable from the underlying tendon. At 24 months all repairs remained intact and normal footprint anatomy of the tendon was restored in all patients. All clinical scores improved significantly over time. Conclusion the ability of a collagen implant to induce new host tissue formation and restore the normal footprint anatomy may represent a significant advancement in the biological augmentation and ultimate durability of rotator cuff repairs. PMID:26605186

  1. Assessment of dehydrothermally cross‐linked collagen membrane for guided bone regeneration around peri-implant dehiscence defects: a randomized single-blinded clinical trial

    PubMed Central

    2015-01-01

    Purpose The aim of this study was to determine the clinical feasibility of using dehydrothermally cross‐linked collagen membrane (DCM) for bone regeneration around peri-implant dehiscence defects, and compare it with non-cross-linked native collagen membrane (NCM). Methods Dehiscence defects were investigated in twenty-eight patients. Defect width and height were measured by periodontal probe immediately following implant placement (baseline) and 16 weeks afterward. Membrane manipulation and maintenance were clinically assessed by means of the visual analogue scale score at baseline. Changes in horizontal thickness at 1 mm, 2 mm, and 3 mm below the top of the implant platform and the average bone density were assessed by cone-beam computed tomography at 16 weeks. Degradation of membrane was histologically observed in the soft tissue around the implant prior to re-entry surgery. Results Five defect sites (two sites in the NCM group and three sites in the DCM group) showed soft-tissue dehiscence defects and membrane exposure during the early healing period, but there were no symptoms or signs of severe complications during the experimental postoperative period. Significant clinical and radiological improvements were found in all parameters with both types of collagen membrane. Partially resorbed membrane leaflets were only observed histologically in the DCM group. Conclusions These findings suggest that, compared with NCM, DCM has a similar clinical expediency and possesses more stable maintenance properties. Therefore, it could be used effectively in guided bone regeneration around dehiscence-type defects. PMID:26732806

  2. Dermal peels.

    PubMed

    Coleman, W P

    2001-07-01

    Dermal chemical peeling is a very satisfying procedure for patients and physicians alike. Although not providing the ablation of deep wrinkles and scars that dermabrasion and laser procedures may accomplish, trichloroacetic acid peels usually result in few complications and rapid recovery. Patients can usually expect photographic improvement in their skin. The results are usually long lasting, and most patients do not need to repeat dermal peels for at least 2 years. Of all resurfacing procedures, dermal peeling provides the best benefit-to-risk ratio. PMID:11599397

  3. Infrared microscopic investigation of skin biopsies after application of implant material for correction of aesthetic deficiencies

    NASA Astrophysics Data System (ADS)

    Heise, H. M.; Seifert, L.; Kuckuk, R.; Lenzen, C.

    2003-06-01

    Different implant materials are currently applied for correction of inborn and acquired aesthetic deficiencies of the human skin. Several commercial products are used as dermal fillers for aesthetic facial surgery, which contain bovine collagen and cross-linked substances, or hyaluronic acid derivatives, both also in combination with polymethylmethacrylate or co-polymerisates of methacrylate derivatives. Gels containing polylactate or dimethylpolysiloxane were also available. Infrared spectra of such products are presented after dry film preparation. Infrared microscopy using attenuated total reflection was employed to identify previously applied dermal filler products in excised tissue without embedding the sample in a matrix material such as paraffin as needed for microtoming. Several tissue spots guided by inspecting the different color grades were found with increased single implant component concentrations, as supported by the dominating spectral features and difference spectroscopy. The chemistry within dermal biopsies after material implantation can be uniquely investigated based on their infrared spectra.

  4. Treatment of Pseudoangiomatous Stromal Hyperplasia of the Breast: Implant-Based Reconstruction with a Vascularized Dermal Sling

    PubMed Central

    Jung, Bok Ki; Nahm, Ji Hae; Lew, Dae Hyun

    2015-01-01

    Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign mesenchymal lesion with incidental histologic findings. Surgical excision is recommended as the treatment of choice for PASH, although the recurrence rates after excision range from 15% to 22%. A 46-year-old-female presented with a six-month history of bilateral breast enlargement and painful sensation mimicking inflammatory carcinoma. Imaging studies demonstrated innumerable enhancing nodules in both breasts. Due to the growth of the lesions and progressive clinical symptoms, bilateral subcutaneous mastectomy was performed. Grossly, the specimens were round and well-circumscribed, and the histologic examination revealed PASH. After mastectomy, we created a pocket with the pectoralis major muscle and a lower skin flap, which was deepithelized. Anatomical mammary implants were inserted, and the nipple areolar complex was transferred to a new position as a free graft. The aesthetic result was satisfactory after twelve months of follow-up. PMID:26430637

  5. Living skin substitutes: survival and function of fibroblasts seeded in a dermal substitute in experimental wounds.

    PubMed

    Lamme, E N; van Leeuwen, R T; Jonker, A; van Marle, J; Middelkoop, E

    1998-12-01

    The healing of full-thickness skin defects requires extensive synthesis and remodeling of dermal and epidermal components. Fibroblasts play an important role in this process and are being incorporated in the latest generation of artificial dermal substitutes. We studied the fate of fibroblasts seeded in our artificial elastin/collagen dermal substitute and the influence of the seeded fibroblasts on cell migration and dermal substitute degradation after transplantation to experimental full-thickness wounds in pigs. Wounds were treated with either dermal substitutes seeded with autologous fibroblasts or acellular substitutes. Seeded fibroblasts, labeled with a PKH-26 fluorescent cell marker, were detected in the wounds with fluorescence microscopy and quantitated with flow cytofluorometric analysis of single-cell suspensions of wound tissue. The cellular infiltrate was characterized for the presence of mesenchymal cells (vimentin), monocytes/macrophages, and vascular cells. Dermal substitute degradation was quantitated by image analysis of wound sections stained with Herovici's staining. In the wounds treated with the seeded dermal substitute, fluorescent PKH-26-labeled cells were detectable up to 6 d and were positive for vimentin but not for the macrophage antibody. After 5 d, flow cytofluorometry showed the presence of 3.1 (+/-0.9) x 10(6) (mean +/- SD, n = 7) PKH-26-positive cells in these wounds, whereas initially only 1 x 10(6) fluorescent fibroblasts had been seeded. In total, the percentage of mesenchymal cells minus the macrophages was similar after 5 d between wounds treated with the seeded and the acellular substitutes. In the wounds treated with the seeded substitute, however, 19.5% of the mesenchymal cells were of seeded origin. Furthermore, the rate of substitute degradation in the seeded wounds was significantly lower at 2-4 wk after wounding than in wounds treated with the acellular substitute. Vascular in-growth and the number of infiltrated

  6. Mechanical and biocompatible characterization of a cross-linked collagen-hyaluronic acid wound dressing.

    PubMed

    Kirk, James F; Ritter, Gregg; Finger, Isaac; Sankar, Dhyana; Reddy, Joseph D; Talton, James D; Nataraj, Chandra; Narisawa, Sonoko; Millán, José Luis; Cobb, Ronald R

    2013-01-01

    Collagen scaffolds have been widely employed as a dermal equivalent to induce fibroblast infiltrations and dermal regeneration in the treatment of chronic wounds and diabetic foot ulcers. Cross-linking methods have been developed to address the disadvantages of the rapid degradation associated with collagen-based scaffolds. To eliminate the potential drawbacks associated with glutaraldehyde cross-linking, methods using a water soluble carbodiimide have been developed. In the present study, the glycosaminoglycan (GAG) hyaluronic acid (HA), was covalently attached to an equine tendon derived collagen scaffold using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) to create ntSPONGE The HA was shown to be homogeneously distributed throughout the collagen matrix. In vitro analyses of the scaffold indicated that the cross-linking enhanced the biological stability by decreasing the enzymatic degradation and increasing the thermal denaturation temperature. The material was shown to support the attachment and proliferation of mouse L929 fibroblast cells. In addition, the cross-linking decreased the resorption rate of the collagen as measured in an intramuscular implant model in rabbits. The material was also shown to be biocompatible in a variety of in vitro and in vivo assays. These results indicate that this cross-linked collagen-HA scaffold, ntSPONGE has the potential for use in chronic wound healing.

  7. Rapid onset of perfused blood vessels after implantation of ECFCs and MPCs in collagen, PuraMatrix and fibrin provisional matrices.

    PubMed

    Allen, Patrick; Kang, Kyu-Tae; Bischoff, Joyce

    2015-05-01

    We developed an in vivo vascularization model in which human endothelial colony-forming cells (ECFCs) and human mesenchymal progenitor cells (MPCs) form blood vessel networks when co-injected (ECFC + MPC) into nude mice in rat tail type I collagen, bovine fibrin or synthetic peptide PuraMatrix matrices. We used three approaches to determine the onset of functional vascularization when ECFC + MPC suspended in these matrices were implanted in vivo. The first was immunohistochemistry to detect vessels lined by human endothelial cells and filled with red blood cells. The second was in vivo vascular staining by tail vein injection of a mixture of Ulex europaeus agglutinin I (UEA-I), a lectin specific for human endothelium, and Griffonia simplicifolia isolectin B4 (GS-IB4 ), a lectin specific for rodent endothelium. The third approach employed contrast-enhanced ultrasound to measure the perfusion volumes of implants in individual animals over time. Human endothelial-lined tubular structures were detected in vivo on days 1 and 2 after implantation, with perfused human vessels detected on days 3 and 4. Contrast-enhanced ultrasound revealed significant perfusion of ECFC + MPC/collagen implants on days 1-4, at up to 14% perfused vascular volume. ECFC + MPC implanted in fibrin and PuraMatrix matrices also supported perfusion at day 1, as assessed by ultrasound (at 12% and 23% perfused vascular volume, respectively). This model demonstrates that ECFC + MPC suspended in any of the three matrices initiated a rapid onset of vascularization. We propose that ECFC + MPC delivered in vivo provide a means to achieve rapid perfusion of tissue-engineered organs or for in situ tissue repair.

  8. Novel hydrogels based on carboxyl pullulan and collagen crosslinking with 1, 4-butanediol diglycidylether for use as a dermal filler: initial in vitro and in vivo investigations.

    PubMed

    Li, Xian; Xue, Wenjiao; Zhu, Chenhui; Fan, Daidi; Liu, Yannan; XiaoxuanMa

    2015-12-01

    Novel hydrogels based on carboxyl pullulan (PC) and human-like collagen (HLC) crosslinking with 1,4-butanediol diglycidyl ether (BDDE) are promising soft fillers for tissue engineering due to their highly tunable properties. Recent studies, however, have shown that incorporating hyaluronic acid and BDDE results in hydrogels with a microporous structure, a large pore size and high porosity, which reduce cell adhesion and enhance degradation in vivo. To improve biocompatibility and prevent biodegradation, the use of PC to replace hyaluronic acid in the fabrication of PC/BDDE (PCB) and PC/BDDE/HLC (PCBH) hydrogels was investigated. Preparation of gels with PC is a promising strategy due to the high reactivity, superb selectivity, and mild reaction conditions of PC. In particular, the Schiff base reaction of HLC and PC produces the novel functional group -RCONHR' in PCBH hydrogels. Twenty-four weeks after subcutaneous injection of either PCB or PCBH hydrogel in mice, the surrounding tissue inflammation, enzymatic response and cell attachment were better compared to hyaluronic acid-based hydrogels. However, the biocompatibility, cytocompatibility and non-biodegradability of PCBH were milder than those of the PCB hydrogels both in vivo and in vitro. These results show that the proposed use of PC and HLC for the fabrication of hydrogels is a promising strategy for generating soft filler for tissue engineering.

  9. Novel hydrogels based on carboxyl pullulan and collagen crosslinking with 1, 4-butanediol diglycidylether for use as a dermal filler: initial in vitro and in vivo investigations.

    PubMed

    Li, Xian; Xue, Wenjiao; Zhu, Chenhui; Fan, Daidi; Liu, Yannan; XiaoxuanMa

    2015-12-01

    Novel hydrogels based on carboxyl pullulan (PC) and human-like collagen (HLC) crosslinking with 1,4-butanediol diglycidyl ether (BDDE) are promising soft fillers for tissue engineering due to their highly tunable properties. Recent studies, however, have shown that incorporating hyaluronic acid and BDDE results in hydrogels with a microporous structure, a large pore size and high porosity, which reduce cell adhesion and enhance degradation in vivo. To improve biocompatibility and prevent biodegradation, the use of PC to replace hyaluronic acid in the fabrication of PC/BDDE (PCB) and PC/BDDE/HLC (PCBH) hydrogels was investigated. Preparation of gels with PC is a promising strategy due to the high reactivity, superb selectivity, and mild reaction conditions of PC. In particular, the Schiff base reaction of HLC and PC produces the novel functional group -RCONHR' in PCBH hydrogels. Twenty-four weeks after subcutaneous injection of either PCB or PCBH hydrogel in mice, the surrounding tissue inflammation, enzymatic response and cell attachment were better compared to hyaluronic acid-based hydrogels. However, the biocompatibility, cytocompatibility and non-biodegradability of PCBH were milder than those of the PCB hydrogels both in vivo and in vitro. These results show that the proposed use of PC and HLC for the fabrication of hydrogels is a promising strategy for generating soft filler for tissue engineering. PMID:26354254

  10. [Evaluation of selected parameters of collagen metabolism in rats after implantation of copolymer d,l-lactide and E-caprolacton with cortisol and progesterone].

    PubMed

    Nowak, M; Swietochowska, E; Buntner, B; Ostrowska, Z; Górski, J; Bero, M; Kajdaniuk, D; Głogowska-Szelag, J; Siemińska, L; Spyra, Z

    1995-01-01

    Tests were carried out on the possibility of biodegradable copolymer d, l-lactide and E-caprolacton as a carrier system for a long-term substitution of progesterone and cortisole. During 120 days of the experiment almost linear profile of freeing of progesterone with average rate 0.5% of the initial amount of hormone (24 hours, what indicates a practical possibility of its application in hormonal substitution) was obtained. Simultaneously the influence of copolymer implants on the metabolism of collagen was tested marking the concentrations P I CP and P III NP in particular periods of the experiment. We did not notice any permanent changes of metabolism of collagen under the influence of the tested carrier system of the hormonal medicaments and the obtained changes of concentrations P I CP and P III NP are probably caused by the hormones freeing from the subgrade. PMID:8610063

  11. A novel dermal matrix generated from burned skin as a promising substitute for deep-degree burns therapy.

    PubMed

    Yu, Guanying; Ye, Lan; Tan, Wei; Zhu, Xuguo; Li, Yaonan; Jiang, Duyin

    2016-03-01

    The extensive skin defects induced by severe burns are dangerous and can be fatal. Currently, the most common therapy is tangential excision to remove the necrotic or denatured areas of skin, followed by skin grafting. Xenogeneic dermal substitutes, such as porcine acellular dermal matrix (ADM), are typically used to cover the burn wounds, and may accelerate wound healing. It is assumed that burned skin that still maintains partial biological activity may be recycled to construct an autologous acellular dermal matrix, termed 'deep‑degree burned dermal matrix (DDBDM)'. In theory, DDBDM may avoid the histoincompatibility issues associated with foreign or xenogeneic dermal matrices, and reduce therapy costs by making full use of discarded skin. In the present study, the collagens within prepared DDBDM were thickened, disorganized and partially fractured, however, they still maintained their reticular structure and tensile strength (P<0.01). Through microarray analysis of the cytokines present in ADM and DDBDM, it was determined that the DDBDM did not produce excessive levels of harmful burn toxins. Following 4 weeks of subcutaneous implantation, ADM and DDBDM were incompletely degraded and maintained good integrity. No significant inflammatory reaction or rejection were observed, which indicated that ADM and DDBDM have good histocompatibility. Therefore, DDBDM may be a useful material for the treatment of deep‑degree burns. PMID:26846279

  12. A novel dermal matrix generated from burned skin as a promising substitute for deep-degree burns therapy

    PubMed Central

    YU, GUANYING; YE, LAN; TAN, WEI; ZHU, XUGUO; LI, YAONAN; JIANG, DUYIN

    2016-01-01

    The extensive skin defects induced by severe burns are dangerous and can be fatal. Currently, the most common therapy is tangential excision to remove the necrotic or denatured areas of skin, followed by skin grafting. Xenogeneic dermal substitutes, such as porcine acellular dermal matrix (ADM), are typically used to cover the burn wounds, and may accelerate wound healing. It is assumed that burned skin that still maintains partial biological activity may be recycled to construct an autologous acellular dermal matrix, termed 'deep-degree burned dermal matrix (DDBDM)'. In theory, DDBDM may avoid the histoincompatibility issues associated with foreign or xenogeneic dermal matrices, and reduce therapy costs by making full use of discarded skin. In the present study, the collagens within prepared DDBDM were thickened, disorganized and partially fractured, however, they still maintained their reticular structure and tensile strength (P<0.01). Through microarray analysis of the cytokines present in ADM and DDBDM, it was determined that the DDBDM did not produce excessive levels of harmful burn toxins. Following 4 weeks of subcutaneous implantation, ADM and DDBDM were incompletely degraded and maintained good integrity. No significant inflammatory reaction or rejection were observed, which indicated that ADM and DDBDM have good histocompatibility. Therefore, DDBDM may be a useful material for the treatment of deep-degree burns. PMID:26846279

  13. Silk fibroin/chondroitin sulfate/hyaluronic acid ternary scaffolds for dermal tissue reconstruction.

    PubMed

    Yan, Shuqin; Zhang, Qiang; Wang, Jiannan; Liu, Yu; Lu, Shenzhou; Li, Mingzhong; Kaplan, David L

    2013-06-01

    The fabrication of new dermal substitutes providing mechanical support and cellular cues is urgently needed in dermal reconstruction. Silk fibroin (SF)/chondroitin sulfate (CS)/hyaluronic acid (HA) ternary scaffolds (95-248μm in pore diameter, 88-93% in porosity) were prepared by freeze-drying. By the incorporation of CS and HA with the SF solution, the chemical potential and quantity of free water around ice crystals could be controlled to form smaller pores in the SF/CS/HA ternary scaffold main pores and improve scaffold equilibrium swelling. This feature offers benefits for cell adhesion, survival and proliferation. In vivo SF, SF/HA and SF/CS/HA (80/5/15) scaffolds as dermal equivalents were implanted onto dorsal full-thickness wounds of Sprague-Dawley rats to evaluate wound healing. Compared to SF and SF/HA scaffolds, the SF/CS/HA (80/5/15) scaffolds promoted dermis regeneration, related to improved angiogenesis and collagen deposition. Further, vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) expression in the SF/CS/HA (80/5/15) groups were investigated by immunohistochemistry to assess the mechanisms involved in the stimulation of secretion of VEGF, PDGF and bFGF and accumulation of these growth factors related to accelerated wound process. These new three-dimensional ternary scaffolds offer potential for dermal tissue regeneration.

  14. Complications of collagen fillers.

    PubMed

    Lucey, Patricia; Goldberg, David J

    2014-12-01

    As the skin ages, a deficiency in collagen occurs, thus injectable collagen products have become a sensible and popular option for dermal filling and volume enhancement. Several types of collagen have been developed over the years, including animal sources such as bovine and porcine collagen, as well as human-based sources derived from pieces of the patient's own skin, cadaver skin, and later cultured from human dermal fibroblasts. While collagen overall has a relatively safe, side effect profile, there are several complications, both early and late onset, that practitioners and patients should be aware of. Early complications, occurring within days of the procedure, can be divided into non-hypersensitivity and hypersensitivity reactions. The non-hypersensitive reactions include injection site reactions, discoloration, maldistribution, infection, skin necrosis, and the very rare but dreaded risk of vision loss, whereas the hypersensitivity reactions present usually as delayed type IV reactions, but can also rarely present as an immediate type I reaction. Late complications, occurring within weeks to even years after injection, include granuloma formation, foreign body reactions, and infection secondary to atypical mycobacteria or biofilms. This review will give a detailed overview of the complications secondary to cutaneous collagen injections.

  15. Safety and Visual Outcome of Visian Toric ICL Implantation after Corneal Collagen Cross-Linking in Keratoconus: Up to 2 Years of Follow-Up.

    PubMed

    Antonios, Rafic; Dirani, Ali; Fadlallah, Ali; Chelala, Elias; Hamade, Adib; Cherfane, Carole; Jarade, Elias

    2015-01-01

    Purpose. To evaluate the long-term safety and clinical outcome of phakic Visian toric implantable collamer lens (ICL) insertion after corneal collagen cross-linking (CXL) in progressive keratoconus. Methods. This was a retrospective study of 30 eyes (19 patients), with progressive keratoconus, who underwent sequential CXL followed by Visian toric ICL implantation after 6 months. Results. At baseline, 6 eyes had stage I, 14 eyes stage II, and 10 eyes stage III keratoconus graded by Amsler-Krumeich classification. At 6 months after CXL, only K (steep) and K (max) decreased significantly from baseline, with no change in visual acuity or refraction. Flattening in keratometric readings was stable thereafter. There was significant improvement in mean uncorrected distance visual acuity (1.57 ± 0.56 to 0.17 ± 0.06 logMAR, P < 0.001) and mean corrected distance visual acuity (0.17 ± 0.08 to 0.11 ± 0.05 logMAR, P < 0.001) at 12 months after ICL implantation that was maintained at the 2-year follow-up. Mean cylinder power and mean spherical equivalent (SE) also decreased significantly after ICL implantation. A small hyperopic shift in SE (+0.25 D) was observed at 2 years that did not alter visual outcomes. Conclusions. Visian toric ICL implantation following CXL is an effective option for improving visual acuity in patients with keratoconus up to 2 years. PMID:25874116

  16. Structure of collagen adsorbed on a model implant surface resolved by polarization modulation infrared reflection-absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Brand, Izabella; Habecker, Florian; Ahlers, Michael; Klüner, Thorsten

    2015-03-01

    The polarization modulation infrared reflection-absorption spectra of collagen adsorbed on a titania surface and quantum chemical calculations are used to describe components of the amide I mode to the protein structure at a sub-molecular level. In this study, imino acid rich and poor fragments, representing the entire collagen molecule, are taken into account. The amide I mode of the collagen triple helix is composed of three absorption bands which involve: (i) (∼1690 cm-1) the Cdbnd O stretching modes at unhydrated groups, (ii) (1655-1673 cm-1) the Cdbnd O stretching at carbonyl groups at imino acids and glycine forming intramolecular hydrogen bonds with H atoms at both NH2 and, unusual for proteins, CH2 groups at glycine at a neighbouring chain and (iii) (∼1640 cm-1) the Cdbnd O stretching at carbonyl groups forming hydrogen bonds between two, often charged, amino acids as well as hydrogen bonds to water along the entire helix. The IR spectrum of films prepared from diluted solutions (c < 50 μg ml-1) corresponds to solution spectra indicating that native collagen molecules interact with water adsorbed on the titania surface. In films prepared from solutions (c ⩾ 50 μg ml-1) collagen multilayers are formed. The amide I mode is blue-shifted by 18 cm-1, indicating that intramolecular hydrogen bonds at imino acid rich fragments are weakened. Simultaneous red-shift of the amide A mode implies that the strength of hydrogen bonds at the imino acid poor fragments increases. Theoretically predicted distortion of the collagen structure upon adsorption on the titania surface is experimentally confirmed.

  17. Volumetric analysis of implanted biphasic calcium phosphate/collagen composite by three-dimensional cone beam computed tomography head model superimposition.

    PubMed

    Grybauskas, Simonas; Locs, Janis; Salma, Ilze; Salms, Girts; Berzina-Cimdina, Liga

    2015-01-01

    Facial onlay augmentation is often performed as an ancillary procedure simultaneously with orthognathic surgery to improve facial appearance, with hydroxyapatite (HAp) and HAp-based composites often used as the materials of choice. The ability to apply HAp in a granular rather than solid shape form may be responsible for its comparatively reduced rate of complications. However, a known complication of HAp and HAp composites is reduction of implant volume over time associated with resorption of the material. Evaluation of the volumetric changes of implanted biphasic calcium phosphate (HAp/β-TCP)/collagen composite in the malar areas from baseline to 4 months, 9-12 months, and 18-24 months after surgery using cone beam computed tomography (CBCT) surface superimposition and volumetric subtraction was done. The average decrease of volume of implanted HAp/β-TCP 4 months after surgery was 18.6%. Further volumetric decreases were negligible and a mean total volume loss of 21.65% was found at 18-24 months postoperatively. PMID:25491277

  18. Type V collagen controls the initiation of collagen fibril assembly.

    PubMed

    Wenstrup, Richard J; Florer, Jane B; Brunskill, Eric W; Bell, Sheila M; Chervoneva, Inna; Birk, David E

    2004-12-17

    Vertebrate collagen fibrils are heterotypically composed of a quantitatively major and minor fibril collagen. In non-cartilaginous tissues, type I collagen accounts for the majority of the collagen mass, and collagen type V, the functions of which are poorly understood, is a minor component. Type V collagen has been implicated in the regulation of fibril diameter, and we reported recently preliminary evidence that type V collagen is required for collagen fibril nucleation (Wenstrup, R. J., Florer, J. B., Cole, W. G., Willing, M. C., and Birk, D. E. (2004) J. Cell. Biochem. 92, 113-124). The purpose of this study was to define the roles of type V collagen in the regulation of collagen fibrillogenesis and matrix assembly. Mouse embryos completely deficient in pro-alpha1(V) chains were created by homologous recombination. The col5a1-/- animals die in early embryogenesis, at approximately embryonic day 10. The type V collagen-deficient mice demonstrate a virtual lack of collagen fibril formation. In contrast, the col5a1+/- animals are viable. The reduced type V collagen content is associated with a 50% reduction in fibril number and dermal collagen content. In addition, relatively normal, cylindrical fibrils are assembled with a second population of large, structurally abnormal collagen fibrils. The structural properties of the abnormal matrix are decreased relative to the wild type control animals. These data indicate a central role for the evolutionary, ancient type V collagen in the regulation of fibrillogenesis. The complete dependence of fibril formation on type V collagen is indicative of the critical role of the latter in early fibril initiation. In addition, this fibril collagen is important in the determination of fibril structure and matrix organization. PMID:15383546

  19. Viscoelastic, physical, and bio-degradable properties of dermal scaffolds and related cell behaviour.

    PubMed

    Sharma, Vaibhav; Patel, Nimesha; Kohli, Nupur; Ravindran, Nivedita; Hook, Lilian; Mason, Chris; García-Gareta, Elena

    2016-01-01

    Dermal scaffolds promote healing of debilitating skin injuries caused by burns and chronic skin conditions. Currently available products present disadvantages and therefore, there is still a clinical need for developing new dermal substitutes. This study aimed at comparing the viscoelastic, physical and bio-degradable properties of two dermal scaffolds, the collagen-based and clinically well established Integra(®) and a novel fibrin-based dermal scaffold developed at our laboratory called Smart Matrix(®), to further evaluate our previous published findings that suggested a higher influx of cells, reduced wound contraction and less scarring for Smart Matrix(®) when used in vivo. Rheological results showed that Integra(®) (G'  =  313.74 kPa) is mechanically stronger than Smart Matrix(®) (G'  =  8.26 kPa), due to the presence of the silicone backing layer in Integra(®). Micro-pores were observed on both dermal scaffolds, although nano-pores as well as densely packed nano-fibres were only observed for Smart Matrix(®). Average surface roughness was higher for Smart Matrix(®) (Sa  =  114.776 nm) than for Integra(®) (Sa  =  75.565 nm). Both scaffolds possess a highly porous structure (80-90%) and display a range of pore micro-sizes that represent the actual in vivo scenario. In vitro proteolytic bio-degradation suggested that Smart Matrix(®) would degrade faster upon implantation in vivo than Integra(®). For both scaffolds, the enzymatic digestion occurs via bulk degradation. These observed differences could affect cell behaviour on both scaffolds. Our results suggest that fine-tuning of scaffolds' viscoelastic, physical and bio-degradable properties can maximise cell behaviour in terms of attachment, proliferation and infiltration, which are essential for tissue repair. PMID:27586397

  20. Evidence of healing of partial-thickness rotator cuff tears following arthroscopic augmentation with a collagen implant: a 2-year MRI follow-up

    PubMed Central

    Bokor, Desmond John; Sonnabend, David; Deady, Luke; Cass, Ben; Young, Allan; Van Kampen, Craig; Arnoczky, Steven

    2016-01-01

    Summary Background partial-thickness rotator cuff tears frequently enlarge due to increased local strain and often progress to full-thickness tears. Studies suggest the addition of new tendinous tissue to injured cuff tendons would significantly decrease peak strain, possibly protecting against tear progression. The aim of this study was to assess the ability of a highly-porous collagen implant to induce new tissue formation and limit tear progression when placed on the bursal surface of partial-thickness cuff tears. Methods following arthroscopic subacromial decompression, the implant was attached to the bursal surface of the supraspinatus tendon in a prospective series of 13 consecutive patients with intermediate – (3–6 mm) to high-grade (>6 mm) partial – thickness cuff tears (5 articular, 3 bursal, 5 intra-substance). Tendon thickness, defect size, and tendon quality were evaluated using magnetic resonance imaging (MRI) preoperatively and at 3, 6, 12, and 24 months postoperatively. Clinical outcomes were assessed using the Constant and American Shoulder and Elbow Society scores at the same preoperative and follow-up times. All 13 patients completed all follow-up exams (mean length of follow-up 27.0 months, range 23.3–32.0); no patients were lost to follow-up. Results the implant induced significant new tissue formation in all patients by 3 months (mean increase in tendon thickness 2.2 ± 0.26 mm). This tissue matured over time and became radiologically indistinguishable from the underlying tendon. The partial-thickness cuff tears showed consistent filling of the defects, with complete healing in 7 patients at 12 months, and a progressive improvement in tendon quality in the remaining patients. No tear progression was observed by MRI in any of the patients at 24 months. All clinical scores improved significantly over time. At 24 months, 12 of 13 patients (92%) had satisfactory or better results. Conclusions the results of this clinical study demonstrated

  1. Reconstruction of #7 facial cleft with distraction-assisted in situ osteogenesis (DISO): role of recombinant human bone morphogenetic protein-2 with Helistat-activated collagen implant.

    PubMed

    Carstens, Michael H; Chin, Martin; Ng, Theodore; Tom, William K

    2005-11-01

    A case involving concomitant presentation of a #7 lateral facial cleft with a complete cleft of the ipsilateral lip, alveolus, and palate is presented. The mandibular defect was Pruzansky III with a foreshortened body, absent ramus and absent masseter. Taking advantage of developmental field theory, reconstruction of the osseous defect was undertaken using the autogenous periosteum as a source of mesenchymal stem cells. Expansion of the periosteum was followed by implantation of Helistat (Integra Life Sciences, Plainsboro, NJ) collagen sponge saturated with recombinant human bone morphogenetic protein-2. Stimulation of this distraction-induced envelope by rhBMP-2 resulted in abundant production of bicortical membranous bone in situ within 12 weeks. The neoramus was subsequently suspended from the cranial base, and a temporalis muscle transfer was used to provide motor control of the jaw. Synthesis of bone in this manner is termed DISO (distraction-assisted in situ osteogenesis). The biologic rationale and clinical implications of DISO are discussed.

  2. Dermal exudate macrophages. Induction in dermal chambers and response to lymphokines.

    PubMed Central

    Goihman-Yahr, M; Ulrich, M; Noya-León, A; Rojas, A; Convit, J

    1975-01-01

    Chambers were implanted in the dorsum of guinea-pigs at the dermal-subcutaneous junction. Exudates were induced and harvested. Macrophages obtained were able to migrate in vitro. If procured from sensitized donors, macrophage migration was inhibited by the corresponding antigen. Dermal exudate macrophages are therefore subject to the effect of lymphokines. The chamber model may be useful for in vivo studies of cell to cell and cell-parasite interactions. PMID:1212821

  3. PLLA-collagen and PLLA-gelatin hybrid scaffolds with funnel-like porous structure for skin tissue engineering

    NASA Astrophysics Data System (ADS)

    Lu, Hongxu; Oh, Hwan Hee; Kawazoe, Naoki; Yamagishi, Kozo; Chen, Guoping

    2012-12-01

    In skin tissue engineering, a three-dimensional porous scaffold is necessary to support cell adhesion and proliferation and to guide cells moving into the repair area in the wound healing process. Structurally, the porous scaffold should have an open and interconnected porous architecture to facilitate homogenous cell distribution. Moreover, the scaffolds should be mechanically strong to protect deformation during the formation of new skin. In this study, the hybrid scaffolds were prepared by forming funnel-like collagen or gelatin sponge on a woven poly(l-lactic acid) (PLLA) mesh. The hybrid scaffolds combined the advantages of both collagen or gelatin (good cell-interactions) and PLLA mesh (high mechanical strength). The hybrid scaffolds were used to culture dermal fibroblasts for dermal tissue engineering. The funnel-like porous structure promoted homogeneous cell distribution and extracellular matrix production. The PLLA mesh reinforced the scaffold to avoid deformation. Subcutaneous implantation showed that the PLLA-collagen and PLLA-gelatin scaffolds promoted the regeneration of dermal tissue and epidermis and reduced contraction during the formation of new tissue. These results indicate that funnel-like hybrid scaffolds can be used for skin tissue regeneration.

  4. Role of tissue engineered collagen based tridimensional implant on the healing response of the experimentally induced large Achilles tendon defect model in rabbits: a long term study with high clinical relevance

    PubMed Central

    2013-01-01

    Background Tendon injury is one of the orthopedic conditions poses with a significant clinical challenge to both the surgeons and patients. The major limitations to manage these injuries are poor healing response and development of peritendinous adhesions in the injured area. This study investigated the effectiveness of a novel collagen implant on tendon healing in rabbits. Results Seventy five mature White New-Zealand rabbits were divided into treated (n = 55) and control (n = 20) groups. The left Achilles tendon was completely transected and 2 cm excised. The defects of the treated animals were filled with collagen implants and repaired with sutures, but in control rabbits the defects were sutured similarly but the gap was left untreated. Changes in the injured and normal contralateral tendons were assessed weekly by measuring the diameter, temperature and bioelectrical characteristics of the injured area. Clinical examination was done and scored. Among the treated animals, small pilot groups were euthanized at 5, 10, 15, 20, 30, 40 and 60 (n = 5 at each time interval) and the remainder (n = 20) and the control animals at 120 days post injury (DPI). The lesions of all animals were examined at macroscopic and microscopic levels and the dry matter content, water delivery and water uptake characteristics of the lesions and normal contralateral tendons of both groups were analyzed at 120 DPI. No sign of rejection was seen in the treated lesions. The collagen implant was invaded by the inflammatory cells at the inflammatory phase, followed by fibroplasia phase in which remnant of the collagen implant were still present while no inflammatory reaction could be seen in the lesions. However, the collagen implant was completely absorbed in the remodeling phase and the newly regenerated tendinous tissue filled the gap. Compared to the controls, the treated lesions showed improved tissue alignment and less peritendinous adhesion, muscle atrophy and fibrosis

  5. 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

  6. Combined femtosecond laser-assisted intracorneal ring segment implantation and corneal collagen cross-linking for correction of keratoconus

    PubMed Central

    Ibrahim, Osama; Elmassry, Ahmed; Said, Amr; Abdalla, Moones; El Hennawi, Hazem; Osman, Ihab

    2016-01-01

    Purpose To assess the safety, predictability, and effectiveness of Keraring intrastromal corneal ring segments (ICRS) insertion assisted by femtosecond laser and corneal collagen cross-linking (CXL) for keratoconus correction. Patients and methods In this prospective, noncomparative, and interventional case series, 160 eyes of 100 adult keratoconus patients with poor best-corrected visual acuity (BCVA) (less than 0.7) and intolerance to contact lens wear were included. Patients underwent femtosecond laser-assisted placement of ICRS and CXL. All patients were examined for a complete ophthalmological test: uncorrected visual acuity (UCVA), BCVA, spherical equivalent, keratometry (K1-flat and K2-steep), pachymetry, and Scheimpflug imaging with the Pentacam at 1 week and at 1, 3, and 6 months postoperatively. Results At 6 months, a significant difference was observed (P<0.001) in mean UCVA and BCVA from 0.92±0.677 and 0.42±0.600 logMAR preoperatively to 0.20±0.568 and 0.119±0.619 logMAR, respectively. Mean spherical equivalent refractions were significantly lower (P<0.001) at 6 months. Mean keratometry (K) also significantly reduced (P<0.001) from 50.93±5.53 D (K1-flat) and 55.37±5.76 D (K2-steep) to 47.32±4.61 and 51.08±5.38 D, respectively. In terms of pachymetry, no significant difference was observed preoperatively versus postoperatively (P=1.000). Conclusion Keraring ICRS insertion assisted by femtosecond laser and corneal CXL provided significant improvement in visual acuity, spherical equivalent, and keratometry, which suggests that it may be effective, safe, and predictable for keratoconus correction. PMID:27041991

  7. CCN1 contributes to skin connective tissue aging by inducing age-associated secretory phenotype in human skin dermal fibroblasts.

    PubMed

    Quan, Taihao; Qin, Zhaoping; Robichaud, Patrick; Voorhees, John J; Fisher, Gary J

    2011-08-01

    Dermal connective tissue collagen is the major structural protein in skin. Fibroblasts within the dermis are largely responsible for collagen production and turnover. We have previously reported that dermal fibroblasts, in aged human skin in vivo, express elevated levels of CCN1, and that CCN1 negatively regulates collagen homeostasis by suppressing collagen synthesis and increasing collagen degradation (Quan et al. Am J Pathol 169:482-90, 2006, J Invest Dermatol 130:1697-706, 2010). In further investigations of CCN1 actions, we find that CCN1 alters collagen homeostasis by promoting expression of specific secreted proteins, which include matrix metalloproteinases and proinflammatory cytokines. We also find that CCN1-induced secretory proteins are elevated in aged human skin in vivo. We propose that CCN1 induces an "Age-Associated Secretory Phenotype", in dermal fibroblasts, which mediates collagen reduction and fragmentation in aged human skin.

  8. Development of oral and extra-oral endosseous craniofacial implants by using a mesh structure for connective tissue attachment.

    PubMed

    Mita, Atsushi; Yagihara, Atsushi; Wang, Wei; Takakuda, Kazuo

    2014-03-19

    Connective tissue attachment to a mesh structure incorporated on the surface of oral implants and extra-oral endosseous craniofacial implants (EOECI) was investigated. Two types of implants were prepared: TI and TI-Mesh. TI was composed of an upper and a lower component, both comprised of a titanium cylinder, which could be connected using a titanium screw. The composition of the TIMesh was similar, but the lower cylinder had a lateral groove that was covered with a titanium mesh. In animal experiments performed using rat calvaria, the lower component was first implanted and was left submerged for 3 weeks, then the upper component was mounted percutaneously. After an additional 2 weeks, each implant and the surrounding tissues were harvested and evaluated. Histological observations revealed collagen fibers originating from surrounding hypodermal tissues anchored to the mesh structures of the TI-Mesh whereas no such collagen fibers were observed around TI. Significantly greater values of the attachment strength, the thickness of the dermal tissue, the thickness of hypodermal tissue, and the attachment lengths were observed in TI-Mesh than those of TI. Thus connective tissue attachment with collagen fibers anchored to the mesh was achieved by incorporating mesh structures into the percutaneously placed implants.

  9. Visual rehabilitation in low-moderate keratoconus: intracorneal ring segment implantation followed by same-day topography-guided photorefractive keratectomy and collagen cross linking

    PubMed Central

    Zeraid, Ferial M; Jawkhab, Asma A; Al-Tuwairqi, Waleed S; Osuagwu, Uchechukwu L

    2014-01-01

    AIM To present the results of same-day topography-guided photorefractive keratectomy (TG-PRK) and corneal collagen crosslinking (CXL) after previous intrastromal corneal ring segment (ISCR) implantation for keratoconus. METHODS An experimental clinical study on twenty-one eyes of 19 patients aged 27.1±6.6y (range 19-43y), with low to moderate keratoconus who were selected to undergo customized TG-PRK immediately followed by same-day CXL, 9mo after ISCR implantation in a university ophthalmology clinic. Refraction, uncorrected distance visual acuities (UDVA) and corrected distance visual acuities (CDVA), keratometry (K) values, central corneal thickness (CCT) and coma were assessed 3mo after TG-PRK and CXL. RESULTS After TG-PRK/CXL: the mean UDVA (logMAR) improved significantly from 0.66±0.41 to 0.20±0.25 (P<0.05); Kflat value decreased from: 48.44±3.66 D to 43.71±1.95 D; Ksteep value decreased from 45.61±2.40 D to 41.56±2.05 D; Kaverage also decreased from 47.00±2.66 D to 42.42±2.07 D (P<0.05 for all). The mean sphere and cylinder decreased significantly post-surgery from, -3.10±2.99 D to -0.11±0.93 D and from -3.68±1.53 to -1.11±0.75 D respectively, while the CDVA, CCT and coma showed no significant changes. Compared to post-ISCR, significant reductions (P<0.05 or all) in all K values, sphere and cylinder were observed after TG-PRK/CXL. CONCLUSION Same-day combined topography-guided PRK and corneal crosslinking following placement of ISCR is a safe and potentially effective option in treating low-moderate keratoconus. It significantly improves all visual acuity, reduced keratometry, sphere and astigmatism, but causes no change in central corneal thickness and coma. PMID:25349796

  10. Characterization of fibrillar collagen types using multi-dimensional multiphoton laser scanning microscopy.

    PubMed

    Lutz, V; Sattler, M; Gallinat, S; Wenck, H; Poertner, R; Fischer, F

    2012-04-01

    In dermal photodamage the ratio of the collagen types III to I changes. This makes the investigation of the fibrillar collagen type characteristics interesting for skin research. In this study collagen types were characterized using 5-dimensional multiphoton laser scanning microscopy (5D-IVT) that can be applied in vivo. Second harmonic generation (SHG) signals and fluorescence lifetimes of the collagen autofluorescence were analysed. Collagen type I generates a higher SHG intensity and a longer fluorescence lifetime compared to collagen type III. Thus, the SHG intensity decrease found in photodamaged skin might be explained by the increase in collagen type III. Calculating the in vivo relevant increase of collagen type III gives a negligible difference in fluorescence lifetime not qualifying this method for the determination of collagen type changes in dermal photodamage in vivo in human skin. However, for pathologies that exhibit higher differences in collagen types 5D-IVT analysis might be a suitable method.

  11. Engineering human neo-tendon tissue in vitro with human dermal fibroblasts under static mechanical strain.

    PubMed

    Deng, Dan; Liu, Wei; Xu, Feng; Yang, Yang; Zhou, Guangdong; Zhang, Wen Jie; Cui, Lei; Cao, Yilin

    2009-12-01

    Proper cell source is one of the key issues for tendon engineering. Our previous study showed that dermal fibroblasts could be used to successfully engineer tendon in vivo and tenocytes could engineer neo-tendon in vitro with static strain. This study further investigated the possibility of engineering human neo-tendon tissue in vitro using dermal fibroblasts. Human dermal fibroblasts were seeded on polyglycolic acid (PGA) fibers pre-fixed on a U-shape as a mechanical loading group, or simply cultured in a dish as a tension-free group. In addition, human tenocytes were also seeded on PGA fibers with tension as a comparison to human dermal fibroblasts. The results showed that human neo-tendon tissue could be generated using dermal fibroblasts during in vitro culture under static strain and the tissue structure became more mature with the increase of culture time. Longitudinally aligned collagen fibers and spindle shape cells were observed histologically and collagen fibril diameter and tensile strength increased with time and reached a peak at 14 weeks. In contrast, the dermal fibroblast-PGA constructs failed to form neo-tendon, but formed disorganized fibrous tissue in tension-free condition with significantly weaker strength and poor collagen fiber formation. Interestingly, neo-tendon tissues generated with human dermal fibroblasts were indistinguishable from the counterpart engineered with human tenocytes, which supports the viewpoint that human dermal fibroblasts is likely to replace tenocytes for future tendon graft development in vitro with dynamic mechanical loading in a bioreactor system.

  12. Collagenous gastroduodenitis.

    PubMed

    Rustagi, Tarun; Rai, Mridula; Scholes, John V

    2011-10-01

    Collagenous gastroduodenitis is a rare histopathologic entity characterized by marked subepithelial collagen deposition with associated mucosal inflammatory infiltrate. Only 4 cases have been reported, of which 3 had associated collagenous colitis. Collagenous gastroduodenitis without colonic involvement is exceptionally rare with only 1 case reported so far in the literature. We present a case of a 68-year-old woman with dyspepsia and mild anemia, who was found to have nodular gastric and duodenal mucosa on endoscopic examination. Histopathology showed collagenous gastroduodenitis. To the best of our knowledge, this is the second (and first in English literature) reported case of isolated collagenous gastroduodenitis.

  13. Collagenous gastroduodenitis.

    PubMed

    Rustagi, Tarun; Rai, Mridula; Scholes, John V

    2011-10-01

    Collagenous gastroduodenitis is a rare histopathologic entity characterized by marked subepithelial collagen deposition with associated mucosal inflammatory infiltrate. Only 4 cases have been reported, of which 3 had associated collagenous colitis. Collagenous gastroduodenitis without colonic involvement is exceptionally rare with only 1 case reported so far in the literature. We present a case of a 68-year-old woman with dyspepsia and mild anemia, who was found to have nodular gastric and duodenal mucosa on endoscopic examination. Histopathology showed collagenous gastroduodenitis. To the best of our knowledge, this is the second (and first in English literature) reported case of isolated collagenous gastroduodenitis. PMID:21346601

  14. Lipoid proteinosis: an inherited disorder of collagen metabolism?

    PubMed

    Harper, J I; Duance, V C; Sims, T J; Light, N D

    1985-08-01

    The dermal collagen of a patient with lipoid proteinosis was investigated by immunohistochemistry and biochemical analysis. The affected skin was found to contain significantly less collagen per unit dry weight than normal dermis but showed elevated levels of type 3 collagen with respect to type I. Purification of collagen types from affected skin after pepsin digestion showed no novel forms, but a doubling in the yield of type 5 collagen. These results correlated well with those of immunohistochemistry which showed a patchy, diffuse, widely distributed type 3 collagen and an increase in types 4 and 5 collagens associated with 'onion skin' endothelial basement membrane thickening. Estimation of collagen cross-links showed an abnormal pattern with a preponderance of the keto-imine form not normally associated with skin. These results strongly suggest that lipoid proteinosis involves a primary perturbation of collagen metabolism.

  15. Lipoid proteinosis: an inherited disorder of collagen metabolism?

    PubMed

    Harper, J I; Duance, V C; Sims, T J; Light, N D

    1985-08-01

    The dermal collagen of a patient with lipoid proteinosis was investigated by immunohistochemistry and biochemical analysis. The affected skin was found to contain significantly less collagen per unit dry weight than normal dermis but showed elevated levels of type 3 collagen with respect to type I. Purification of collagen types from affected skin after pepsin digestion showed no novel forms, but a doubling in the yield of type 5 collagen. These results correlated well with those of immunohistochemistry which showed a patchy, diffuse, widely distributed type 3 collagen and an increase in types 4 and 5 collagens associated with 'onion skin' endothelial basement membrane thickening. Estimation of collagen cross-links showed an abnormal pattern with a preponderance of the keto-imine form not normally associated with skin. These results strongly suggest that lipoid proteinosis involves a primary perturbation of collagen metabolism. PMID:3896292

  16. Demineralized bone promotes chondrocyte or osteoblast differentiation of human marrow stromal cells cultured in collagen sponges.

    PubMed

    Zhou, Shuanhu; Yates, Karen E; Eid, Karim; Glowacki, Julie

    2005-01-01

    Demineralized bone implants have been used for many types of craniomaxillofacial, orthopedic, periodontal, and hand reconstruction procedures. In previous studies, we showed that demineralized bone powder (DBP) induces chondrogenesis of human dermal fibroblasts in a DBP/collagen sponge system that optimized interactions between particles of DBP and target cells in cell culture. In this study, we test the hypothesis that DBP promotes chondrogenesis or osteogenesis of human marrow stromal cells (hMSCs) in 3-D collagen sponge culture, depending upon the culture conditions. We first confirmed that hMSCs have chondrogenic potential when treated with TGF-beta, either in 2-D monolayer cultures or in 3-D porous collagen sponges. Second, we found that DBP markedly enhanced chondrogenesis in hMSCs in 3-D sponges, as assessed by metachromasia and expression of chondrocyte-specific genes AGGRECAN, COL II, and COL X. Human dermal fibroblasts (hDFs) were used to define mechanisms of chondroinduction because unlike hMSCs they have no inherent chondrogenic potential. In situ hybridization revealed that hDFs vicinal to DBPs express chondrocyte-specific genes AGGRECAN or COL II. Macroarray analysis showed that DBP activates TGF-beta/BMP signaling pathway genes in hDFs. Finally, DBP induced hMSCs to express the osteoblast phenotype when cultured with osteogenic supplements. These studies show how culture conditions can influence the differentiation pathway that human marrow stromal cells follow when stimulated by DBP. These results support the potential to engineer cartilage or bone in vitro by using human bone marrow stromal cells and DBP/collagen scaffolds. PMID:15735899

  17. Collagen telopeptides (cross-linking sites) play a role in collagen gel lattice contraction

    NASA Technical Reports Server (NTRS)

    Woodley, D. T.; Yamauchi, M.; Wynn, K. C.; Mechanic, G.; Briggaman, R. A.

    1991-01-01

    Solubilized interstitial collagens will form a fibrillar, gel-like lattice when brought to physiologic conditions. In the presence of human dermal fibroblasts the collagen lattice will contract. The rate of contraction can be determined by computer-assisted planemetry. The mechanisms involved in contraction are as yet unknown. Using this system it was found that the rate of contraction was markedly decreased when collagen lacking telopeptides was substituted for native collagen. Histidinohydroxylysinonorleucine (HHL) is a major stable trifunctional collagen cross-link in mature skin that involves a carboxyl terminal, telopeptide site 16c, the sixteenth amino acid residue from the carboxy terminal of the telopeptide region of alpha 1 (I) in type I collagen. Little, if any, HHL was present in native, purified, reconstituted, soluble collagen fibrils from 1% acetic acid-extracted 2-year-old bovine skin. In contrast, HHL cross-links were present (0.22 moles of cross-link per mole of collagen) in lattices of the same collagen contracted by fibroblasts. However, rat tail tendon does not contain HHL cross-links, and collagen lattices made of rat tail tendon collagen are capable of contraction. This suggests that telopeptide sites, and not mature HHL cross-links per se, are essential for fibroblasts to contract collagen lattices. Beta-aminopropionitrile fumarate (BAPN), a potent lathyrogen that perturbs collagen cross-linking by inhibition of lysyl oxidase, also inhibited the rate of lattice cell contraction in lattices composed of native collagen. However, the concentrations of BAPN that were necessary to inhibit the contraction of collagen lattices also inhibited fibroblast growth suggestive of cellular toxicity. In accordance with other studies, we found no inhibition of the rate of lattice contraction when fibronectin-depleted serum was used. Electron microscopy of contracted gels revealed typical collagen fibers with a characteristic axial periodicity. The data

  18. Deep dermal fibroblast profibrotic characteristics are enhanced by bone marrow-derived mesenchymal stem cells.

    PubMed

    Ding, Jie; Ma, Zengshuan; Shankowsky, Heather A; Medina, Abelardo; Tredget, Edward E

    2013-01-01

    Hypertrophic scars are a significant fibroproliferative disorder complicating deep injuries to the skin. We hypothesize that activated deep dermal fibroblasts are subject to regulation by bone marrow-derived mesenchymal stem cells (BM-MSCs), which leads to the development of excessive fibrosis following deep dermal injury. We found that the expression of fibrotic factors was higher in deep burn wounds compared with superficial burn wounds collected from burn patients with varying depth of skin injury. We characterized deep and superficial dermal fibroblasts, which were cultured from the deep and superficial dermal layers of normal uninjured skin obtained from abdominoplasty patients, and examined the paracrine effects of BM-MSCs on the fibrotic activities of the cells. In vitro, deep dermal fibroblasts were found higher in the messenger RNA (mRNA) levels of type 1 collagen, alpha smooth muscle actin, transforming growth factor beta, stromal cell-derived factor 1, and tissue inhibitor of metalloproteinase 1, an inhibitor of collagenase (matrix metalloproteinase 1). As well, deep dermal fibroblasts had low matrix metalloproteinase 1 mRNA, produced more collagen, and contracted collagen lattices significantly greater than superficial fibroblasts. By co-culturing layered fibroblasts with BM-MSCs in a transwell insert system, BM-MSCs enhanced the fibrotic behavior of deep dermal fibroblasts, which suggests a possible involvement of BM-MSCs in the pathogenesis of hypertrophic scarring.

  19. Dermal reflectivity determined by optical coherence tomography is an indicator of epidermal hyperplasia and dermal edema within inflamed skin

    NASA Astrophysics Data System (ADS)

    Phillips, Kevin G.; Wang, Yun; Levitz, David; Choudhury, Niloy; Swanzey, Emily; Lagowski, James; Kulesz-Martin, Molly; Jacques, Steven L.

    2011-04-01

    Psoriasis is a common inflammatory skin disease resulting from genetic and environmental alterations of cutaneous immune responses. While numerous therapeutic targets involved in the immunopathogenesis of psoriasis have been identified, the in vivo dynamics of inflammation in psoriasis remain unclear. We undertook in vivo time course focus-tracked optical coherence tomography (OCT) imaging to noninvasively document cutaneous alterations in mouse skin treated topically with Imiquimod (IMQ), an established model of a psoriasis-like disease. Quantitative appraisal of dermal architectural changes was achieved through a two parameter fit of OCT axial scans in the dermis of the form A(x, y, z) = ρ(x, y)exp [ - μ(x, y)z]. Ensemble averaging over 2000 axial scans per mouse in each treatment arm revealed no significant changes in the average dermal attenuation rate, <μ>, however the average local dermal reflectivity <ρ>, decreased significantly following 1, 3, and 6 days of IMQ treatment (p < 0.001) in comparison to vehicle-treated control mice. In contrast, epidermal and dermal thickness changes were only significant when comparing controls and 6-day IMQ treated mice. This suggests that dermal alterations, attributed to collagen fiber bundle enlargement, occur prior to epidermal thickness changes due to hyperplasia and dermal thickness changes due to edema. Dermal reflectivity positively correlated with epidermal hyperplasia (repi2 = 0.78) and dermal edema (rderm2 = 0.86). Our results suggest that dermal reflectivity as measured by OCT can be utilized to quantify a psoriasis-like disease in mice, and thus has the potential to aid in the quantitative assessment of psoriasis in humans.

  20. Age-related disruption of autophagy in dermal fibroblasts modulates extracellular matrix components

    SciTech Connect

    Tashiro, Kanae; Shishido, Mayumi; Fujimoto, Keiko; Hirota, Yuko; Yo, Kazuyuki; Gomi, Takamasa; Tanaka, Yoshitaka

    2014-01-03

    Highlights: •Autophagosomes accumulate in aged dermal fibroblasts. •Autophagic degradation is impaired in aged dermal fibroblasts. •Autophagy disruption affects extracellular matrix components in dermal fibroblasts. -- Abstract: Autophagy is an intracellular degradative system that is believed to be involved in the aging process. The contribution of autophagy to age-related changes in the human skin is unclear. In this study, we examined the relationship between autophagy and skin aging. Transmission electron microscopy and immunofluorescence microscopy analyses of skin tissue and cultured dermal fibroblasts derived from women of different ages revealed an increase in the number of nascent double-membrane autophagosomes with age. Western blot analysis showed that the amount of LC3-II, a form associated with autophagic vacuolar membranes, was significantly increased in aged dermal fibroblasts compared with that in young dermal fibroblasts. Aged dermal fibroblasts were minimally affected by inhibition of autophagic activity. Although lipofuscin autofluorescence was elevated in aged dermal fibroblasts, the expression of Beclin-1 and Atg5—genes essential for autophagosome formation—was similar between young and aged dermal fibroblasts, suggesting that the increase of autophagosomes in aged dermal fibroblasts was due to impaired autophagic flux rather than an increase in autophagosome formation. Treatment of young dermal fibroblasts with lysosomal protease inhibitors, which mimic the condition of aged dermal fibroblasts with reduced autophagic activity, altered the fibroblast content of type I procollagen, hyaluronan and elastin, and caused a breakdown of collagen fibrils. Collectively, these findings suggest that the autophagy pathway is impaired in aged dermal fibroblasts, which leads to deterioration of dermal integrity and skin fragility.

  1. Effectiveness of xenogenous-based bovine-derived platelet gel embedded within a three-dimensional collagen implant on the healing and regeneration of the Achilles tendon defect in rabbits

    PubMed Central

    Moshiri, Ali; Oryan, Ahmad; Meimandi-Parizi, Abdolhamid; Koohi-Hosseinabadi, Omid

    2014-01-01

    Background and objective: Tissue engineering is an option in reconstructing large tendon defects and managing their healing and regeneration. We designed and produced a novel xenogeneic-based bovine platelet, embedded it within a tissue-engineered collagen implant (CI) and applied it in an experimentally induced large tendon defect model in rabbits to test whether bovine platelets could stimulate tendon healing and regeneration in vivo. Methods: One hundred twenty rabbits were randomly divided into two experimental and pilot groups. In all the animals, the left Achilles tendon was surgically excised and the tendon edges were aligned by Kessler suture. Each group was then divided into three groups of control (no implant), treated with CI and treated with collagen-platelet implant. The pilot groups were euthanized at 10, 15, 30 and 40 days post-injury (DPI), and their gross and histologic characteristics were evaluated to study host–graft interaction mechanism. To study the tendon healing and its outcome, the experimental animals were tested during the experiment using hematologic, ultrasonographic and various methods of clinical examinations and then euthanized at 60 DPI and their tendons were evaluated by gross pathologic, histopathologic, scanning electron microscopic, biophysical and biochemical methods. Results: Bovine platelets embedded within a CI increased inflammation at short term while it increased the rate of implant absorption and matrix replacement compared with the controls and CI alone. Treatment also significantly increased diameter, density, amount, alignment and differentiation of the collagen fibrils and fibers and approximated the water uptake and delivery behavior of the healing tendons to normal contralaterals (p < 0.05). Treatment also improved echogenicity and homogenicity of the tendons and reduced peritendinous adhesion, muscle fibrosis and atrophy, and therefore, it improved the clinical scores and physical activity related to the

  2. Collagenous gastritis.

    PubMed

    Colletti, R B; Trainer, T D

    1989-12-01

    Subepithelial fibrosis has previously been reported in the small intestine (collagenous sprue) and colon (collagenous colitis). We report a 15-yr-old girl with chronic gastritis and subepithelial fibrosis of the gastric corpus who presented with recurrent abdominal pain and acute upper gastrointestinal bleeding. Nodularity and erythema of the gastric corpus were persistent endoscopic findings. Biopsies revealed patchy chronic active gastritis with a striking focal thick band of collagen immediately beneath the surface epithelial cells that did not extend to deeper portions of the lamina propria. Contrast radiography demonstrated an abnormal mucosa of the gastric corpus with a mosaiclike surface pattern. Numerous studies have failed to elucidate the etiology. Despite treatment with ranitidine, sucralfate, and furazolidone, there has been no clinical or pathologic improvement. The pathogenesis and prognosis of collagenous gastritis, and its relationship to collagenous sprue and collagenous colitis, remain to be defined. PMID:2583419

  3. Human Dermal Stem/Progenitor Cell-Derived Conditioned Medium Improves Senescent Human Dermal Fibroblasts.

    PubMed

    Jung, Ji-Yong; Shim, Joong Hyun; Choi, Hyun; Lee, Tae Ryong; Shin, Dong Wook

    2015-08-13

    Adult skin stem cells are recognized as potential therapeutics to rejuvenate aged skin. We previously demonstrated that human dermal stem/progenitor cells (hDSPCs) with multipotent capacity could be enriched from human dermal fibroblasts using collagen type IV. However, the effects of hDSPCs on cellular senescence remain to be elucidated. In the present study, we investigated whether conditioned medium (CM) collected from hDSPC cultures (hDSPC-CM) exhibits beneficial effects on senescent fibroblasts. We found that hDSPC-CM promoted proliferation and decreased the expression level of senescence-associated β-galactosidase in senescent fibroblasts. In addition, p53 phosphorylation and p21 expression were significantly reduced in senescent fibroblasts treated with hDSPC-CM. hDSPC-CM restored the expression levels of collagen type I, collagen type III, and tissue inhibitor of metalloproteinase, and antagonized the increase of matrix metalloproteinase 1 expression. Finally, we demonstrated that hDSPC-CM significantly reduced reactive oxygen species levels by specifically up-regulating the expression level of superoxide dismutase 2. Taken together, these data suggest that hDSPC-CM can be applied as a potential therapeutic agent for improving human aged skin.

  4. Collagenous gastritis.

    PubMed

    Jain, Richa; Chetty, Runjan

    2010-12-01

    A 25-year-old patient presented with epigastric pain, which on gastric biopsy revealed the characteristic appearance of collagenous gastritis. There was a thick prominent subepithelial band that was confirmed to be collagen with a Masson's trichrome stain. There was associated Helicobacter pylori gastritis but no evidence of a lymphocytic gastritis. The patient did not have watery diarrhea. Collagenous gastritis can occur in young patients, be restricted to the stomach, and can be associated with celiac disease. PMID:19103610

  5. Enhancing dermal and bone regeneration in calvarial defect surgery

    PubMed Central

    Zanotti, Bruno; Zingaretti, Nicola; Almesberger, Daria; Verlicchi, Angela; Stefini, Roberto; Ragonese, Mauro; Guarneri, Gianni Franco; Parodi, Pier Camillo

    2014-01-01

    Introduction: To optimize the functional and esthetic result of cranioplasty, it is necessary to choose appropriate materials and take steps to preserve and support tissue vitality. As far as materials are concerned, custom-made porous hydroxyapatite implants are biomimetic, and therefore, provide good biological interaction and biointegration. However, before it is fully integrated, this material has relatively low mechanical resistance. Therefore, to reduce the risk of postoperative implant fracture, it would be desirable to accelerate regeneration of the tissues around and within the graft. Objectives: The objective was to determine whether integrating growth-factor-rich platelet gel or supportive dermal matrix into hydroxyapatite implant cranioplasty can accelerate bone remodeling and promote soft tissue regeneration, respectively. Materials and Methods: The investigation was performed on cranioplasty patients fitted with hydroxyapatite cranial implants between 2004 and 2010. In 7 patients, platelet gel was applied to the bone/prosthesis interface during surgery, and in a further 5 patients, characterized by thin, hypotrophic skin coverage of the cranial lacuna, a sheet of dermal matrix was applied between the prosthesis and the overlying soft tissue. In several of the former groups, platelet gel mixed with hydroxyapatite granules was used to fill small gaps between the skull and the implant. To confirm osteointegration, cranial computed tomography (CT) scans were taken at 3-6 month intervals for 1-year, and magnetic resonance imaging (MRI) was used to confirm dermal integrity. Results: Clinical examination performed a few weeks after surgery revealed good dermal regeneration, with thicker, healthier skin, apparently with a better blood supply, which was confirmed by MRI at 3-6 months. Furthermore, at 3-6 months, CT showed good biomimetism of the porous hydroxyapatite scaffold. Locations at which platelet gel and hydroxyapatite granules were used to fill gaps

  6. Histologic, Molecular, and Clinical Evaluation of Explanted Breast Prostheses, Capsules, and Acellular Dermal Matrices for Bacteria

    PubMed Central

    Poppler, Louis; Cohen, Justin; Dolen, Utku Can; Schriefer, Andrew E.; Tenenbaum, Marissa M.; Deeken, Corey; Chole, Richard A.; Myckatyn, Terence M.

    2015-01-01

    Background Subclinical infections, manifest as biofilms, are considered an important cause of capsular contracture. Acellular dermal matrices (ADMs) are frequently used in revision surgery to prevent recurrent capsular contractures. Objective We sought to identify an association between capsular contracture and biofilm formation on breast prostheses, capsules, and ADMs in a tissue expander/implant (TE/I) exchange clinical paradigm. Methods Biopsies of the prosthesis, capsule, and ADM from patients (N = 26) undergoing TE/I exchange for permanent breast implant were evaluated for subclinical infection. Capsular contracture was quantified with Baker Grade and intramammary pressure. Biofilm formation was evaluated with specialized cultures, rtPCR, bacterial taxonomy, live:dead staining, and scanning electron microscopy (SEM). Collagen distribution, capsular histology, and ADM remodeling were quantified following fluorescent and light microscopy. Results Prosthetic devices were implanted from 91 to 1115 days. Intramammary pressure increased with Baker Grade. Of 26 patients evaluated, one patient had a positive culture and one patient demonstrated convincing evidence of biofilm morphology on SEM. Following PCR amplification 5 samples randomly selected for 16S rRNA gene sequencing demonstrated an abundance of suborder Micrococcineae, consistent with contamination. Conclusions Our data suggest that bacterial biofilms likely contribute to a proportion, but not all diagnosed capsular contractures. Biofilm formation does not appear to differ significantly between ADMs or capsules. While capsular contracture remains an incompletely understood but common problem in breast implant surgery, advances in imaging, diagnostic, and molecular techniques can now provide more sophisticated insights into the pathophysiology of capsular contracture. Level of Evidence PMID:26229126

  7. Focal dermal hypoplasia: ultrastructural abnormalities of the connective tissue.

    PubMed

    del Carmen Boente, María; Asial, Raúl A; Winik, Beatriz C

    2007-02-01

    We followed over 10 years three girls with focal dermal hypoplasia syndrome. The histopathological changes demonstrated at the optical level an hypoplastic dermis with thin and scarce collagen bundles and a marked diminution of elastic fibers. Mature adipose tissue was found scattered within the papillary and reticular dermis. No alterations in the basal membrane were observed by immunocytochemical or ultrastructural techniques. Ultrastructurally, in the skin-affected areas, loosely arranged collagen bundles composed of few fibrils were seen scattered in the extracellular matrix. Scarce elastic fibers of normal morphology were also observed. Fibroblasts were smaller, oval-shaped, and diminished in number with a poorly developed cytoplasm. In these fibroblasts, the most conspicuous feature was a remarkable and irregular thickening of the nuclear fibrous lamina. Taking into account that a common link between all laminopaties may be a failure of stem cells to regenerate mesenchymal tissue, this failure would induce the dermal hypoplasia observed in our patients presenting Goltz syndrome.

  8. Collagen for bone tissue regeneration.

    PubMed

    Ferreira, Ana Marina; Gentile, Piergiorgio; Chiono, Valeria; Ciardelli, Gianluca

    2012-09-01

    In the last decades, increased knowledge about the organization, structure and properties of collagen (particularly concerning interactions between cells and collagen-based materials) has inspired scientists and engineers to design innovative collagen-based biomaterials and to develop novel tissue-engineering products. The design of resorbable collagen-based medical implants requires understanding the tissue/organ anatomy and biological function as well as the role of collagen's physicochemical properties and structure in tissue/organ regeneration. Bone is a complex tissue that plays a critical role in diverse metabolic processes mediated by calcium delivery as well as in hematopoiesis whilst maintaining skeleton strength. A wide variety of collagen-based scaffolds have been proposed for different tissue engineering applications. These scaffolds are designed to promote a biological response, such as cell interaction, and to work as artificial biomimetic extracellular matrices that guide tissue regeneration. This paper critically reviews the current understanding of the complex hierarchical structure and properties of native collagen molecules, and describes the scientific challenge of manufacturing collagen-based materials with suitable properties and shapes for specific biomedical applications, with special emphasis on bone tissue engineering. The analysis of the state of the art in the field reveals the presence of innovative techniques for scaffold and material manufacturing that are currently opening the way to the preparation of biomimetic substrates that modulate cell interaction for improved substitution, restoration, retention or enhancement of bone tissue function. PMID:22705634

  9. Bioengineered collagens

    PubMed Central

    Ramshaw, John AM; Werkmeister, Jerome A; Dumsday, Geoff J

    2014-01-01

    Mammalian collagen has been widely used as a biomedical material. Nevertheless, there are still concerns about the variability between preparations, particularly with the possibility that the products may transmit animal-based diseases. Many groups have examined the possible application of bioengineered mammalian collagens. However, translating laboratory studies into large-scale manufacturing has often proved difficult, although certain yeast and plant systems seem effective. Production of full-length mammalian collagens, with the required secondary modification to give proline hydroxylation, has proved difficult in E. coli. However, recently, a new group of collagens, which have the characteristic triple helical structure of collagen, has been identified in bacteria. These proteins are stable without the need for hydroxyproline and are able to be produced and purified from E. coli in high yield. Initial studies indicate that they would be suitable for biomedical applications. PMID:24717980

  10. Relationship between dermal birefringence and the skin surface roughness of photoaged human skin

    NASA Astrophysics Data System (ADS)

    Sakai, Shingo; Nakagawa, Noriaki; Yamanari, Masahiro; Miyazawa, Arata; Yasuno, Yoshiaki; Matsumoto, Masayuki

    2009-07-01

    The dermal degeneration accompanying photoaging is considered to promote skin roughness features such as wrinkles. Our previous study demonstrated that polarization-sensitive spectral domain optical coherence tomography (PS-SD-OCT) enabled noninvasive three-dimensional evaluation of the dermal degeneration of photoaged skin as a change in dermal birefringence, mainly due to collagenous structures. Our purpose is to examine the relationship between dermal birefringence and elasticity and the skin morphology in the eye corner area using PS-SD-OCT. Nineteen healthy male subjects in their seventees were recruited as subjects. A transverse dermal birefringence map, automatically produced by the algorithm, did not show localized changes in the dermal birefringence in the part of the main horizontal wrinkle. The averaged upper dermal birefringence, however, showed depth-dependent correlation with the parameters of skin roughness significantly, suggesting that solar elastosis is a major factor for the progress of wrinkles. Age-dependent parameters of skin elasticity measured with Cutometer did not correlate with the parameters. These results suggest that the analysis of dermal birefringence using PS-SD-OCT enables the evaluation of photoaging-dependent upper dermal degeneration related to the change of skin roughness.

  11. Isolation and cultivation of dermal stem cells that differentiate into functional epidermal melanocytes.

    PubMed

    Li, Ling; Fukunaga-Kalabis, Mizuho; Herlyn, Meenhard

    2012-01-01

    Human melanocytes have been extensively studied, but a melanocyte stem cell reservoir in glabrous skin has not yet been found. Human dermis contains cells that are nonpigmented but can differentiate to several different cell types. We have recently shown that multipotent dermal stem cells isolated from human neonatal foreskins are able to differentiate to multiple cell lineages, including pigmented melanocytes. The dermal stem cells grow as three-dimensional spheres in human embryonic stem cell medium and express some neural crest stem cell and embryonic stem cell markers. Melanocytes derived from dermal stem cells express melanocytic markers and act the same way as mature epidermal melanocytes. Dermal spheres, embedded in the reconstructed dermis consisting of collagen with fibroblasts, can migrate to the basement membrane, where they become pigmented in the same way as epidermal melanocytes suggesting that dermal stem cells can give rise to epidermal melanocytes.

  12. Collagenous gastroduodenitis on collagenous colitis.

    PubMed

    Stolte, M; Ritter, M; Borchard, F; Koch-Scherrer, G

    1990-07-01

    We report on a case of collagenous gastroduodenitis with concomitant collagenous colitis in a 75-year-old woman with watery diarrhea of approximately six months' standing. The step biopsy material obtained from the colon revealed continuous collagenous colitis with thickening of the basal membrane to 30 microns. The biopsies taken from the stomach and duodenum also revealed a band-like deposition of collagen in the duodenum (bulb and proximal portion of the descending portion) along the basal membrane of the lining epithelium, associated with partial atrophy of the villi. In the stomach, this band of collagen was located, parallel to the mucosal surface, at the level of the floor of the foveolae. PMID:2209504

  13. THE IMPACT OF CHEMOTHERAPY AND RADIATION ON THE REMODELING OF ACELLULAR DERMAL MATRICES IN STAGED, PROSTHETIC BREAST RECONSTRUCTION

    PubMed Central

    Myckatyn, Terence M.; Cavallo, Jaime A.; Sharma, Ketan; Gangopadhyay, Noopur; Dudas, Jason R.; Roma, Andres A.; Baalman, Sara; Tenenbaum, Marissa M.; Matthews, Brent D.; Deeken, Corey R.

    2015-01-01

    Background An acellular dermal matrix (ADM) used in prosthetic breast reconstruction will typically incorporate, in time, with the overlying mastectomy skin flap. This remodeling process may be adversely impacted in patients that require chemotherapy and radiation therapies that influence neovascularization and cellular proliferation. Methods Multiple biopsies of the submuscular capsule and ADM were procured from 86 women (N=94 breasts) undergoing exchange of a tissue expander for a breast implant. These were divided by biopsy location : submuscular capsule (control) as well as superiorly, centrally and inferiorly along the ADM. Specimens were assessed grossly for incorporation and semi-quantitatively for cellular infiltration, cell type, fibrous encapsulation, scaffold degradation, extracellular matrix deposition, neovascularization, mean composite remodeling score, as well as Type I and III collagen area and ratio. Five oncologic treatment groups were compared : no adjuvant therapy (untreated), neoadjuvant chemotherapy ± radiation ; and chemotherapy ± radiation. Results ADM and submuscular capsule biopsies were procured 45 to 1805 days after ADM insertion and demonstrated a significant reduction in Type I collagen over time. Chemotherapy adversely impacted fibrous encapsulation relative to the untreated group (p=0.03). Chemotherapy with or without radiation adversely impacted Type I collagen area (p=0.02), cellular infiltration (p<0.01), extracellular matrix deposition (p<0.04), and neovascularization (p<0.01). Radiation exacerbated the adverse impact of chemotherapy for gross incorporation as well as several remodeling parameters. Neoadjuvant chemotherapy also caused a reduction in Type I (p=0.01) and III collagen (p=0.05), extracellular matrix deposition (p=0.03), and scaffold degradation (p=0.02). Conclusions Chemotherapy and radiation therapy limit ADM remodeling. PMID:25539350

  14. Alteration of Skin Properties with Autologous Dermal Fibroblasts

    PubMed Central

    Thangapazham, Rajesh L.; Darling, Thomas N.; Meyerle, Jon

    2014-01-01

    Dermal fibroblasts are mesenchymal cells found between the skin epidermis and subcutaneous tissue. They are primarily responsible for synthesizing collagen and glycosaminoglycans; components of extracellular matrix supporting the structural integrity of the skin. Dermal fibroblasts play a pivotal role in cutaneous wound healing and skin repair. Preclinical studies suggest wider applications of dermal fibroblasts ranging from skin based indications to non-skin tissue regeneration in tendon repair. One clinical application for autologous dermal fibroblasts has been approved by the Food and Drug Administration (FDA) while others are in preclinical development or various stages of regulatory approval. In this context, we outline the role of fibroblasts in wound healing and discuss recent advances and the current development pipeline for cellular therapies using autologous dermal fibroblasts. The microanatomic and phenotypic differences of fibroblasts occupying particular locations within the skin are reviewed, emphasizing the therapeutic relevance of attributes exhibited by subpopulations of fibroblasts. Special focus is provided to fibroblast characteristics that define regional differences in skin, including the thick and hairless skin of the palms and soles as compared to hair-bearing skin. This regional specificity and functional identity of fibroblasts provides another platform for developing regional skin applications such as the induction of hair follicles in bald scalp or alteration of the phenotype of stump skin in amputees to better support their prosthetic devices. PMID:24828202

  15. The value of a new filler material in corrective and cosmetic surgery: DermaLive and DermaDeep.

    PubMed

    Bergeret-Galley, C; Latouche, X; Illouz, Y G

    2001-01-01

    DermaLive is a long-term wrinkle reduction product including two types of components: pure hyaluronic acid, produced in cell culture, and an acrylic hydrogel. The product was first marketed in France and the rest of Europe in 1998. We have over three years of experience with this product. Several studies have been conducted simultaneously, mainly in Germany and in France. At present, DermaLive is used in the long-term correction of natural or acquired skin depressions (caused by aging, trauma) or the creation of volume (lips, sunken cheekbones). It provides a worthwhile alternative to good-quality bioresorbable materials (pure hyaluronic acid or collagen)--materials that are so resorbable, in fact, that most patients are ultimately dissatisfied with the results--and to other so-called permanent materials that patients do not tolerate well. Filling involving the use of autologous fat transplantations, which yields satisfactory results, is not appropriate for ambulatory injection and, therefore, will not be examined in detail. The tolerance experienced with DermaLive three years on is, at present, considered highly satisfactory. The wrinkle reduction effect obtained after the first injection is long-lasting with 60% resorption of the initial material. Two or three injections, with an interval of at least three months between each, may be required to bring about the reduction of some wrinkles or the correction of post-scar depressions. Side effects occurring long after the injection are rare (1.2 for 1,000). They appear mainly as palpable nodules occurring about six months after injection. They are treated by intralesional injection of corticoids. DermaLive and DermaDeep are both filler implants with a long-lasting effect designed for corrective and aesthetic surgery. Instruction of use and intervals between injection sessions must be respected. After DermaLive or DermaDeep injection, injections of pure hyaluronic acid (Juvederm or Restylane) for treatment of fine

  16. Discrimination of collagen in normal and pathological dermis through polarization second harmonic generation

    NASA Astrophysics Data System (ADS)

    Su, Ping-Jung; Chen, Wei-Liang; Hong, Jin-Bon; Li, Tsung-Hsien; Wu, Ruei-Jr; Chou, Chen-Kuan; Lin, Sung-Jan; Dong, Chen-Yuan

    2010-02-01

    We used polarization-resolved, second harmonic generation (P-SHG) microscopy at single pixel resolution for medical diagnosis of pathological skin dermis, and found that P-SHG can be used to distinguish normal and dermal pathological conditions of keloid, morphea, and dermal elastolysis. We find that the histograms of the d33/d31 ratio for the pathological skins to contain two peak values and to be wider than that of the normal case, suggesting that the pathological dermal collagen fibers tend to be more structurally heterogeneous. Our work demonstrates that pixel-resolved, second-order susceptibility microscopy is effective for detecting heterogeneity in spatial distribution of collagen fibers.

  17. Malignant dermal cylindroma in a patient with multiple dermal cylindromas, trichoepitheliomas, and bilateral dermal analogue tumors of the parotid gland.

    PubMed

    Rockerbie, N; Solomon, A R; Woo, T Y; Beals, T F; Ellis, C N

    1989-08-01

    A malignant dermal cylindroma of the scalp arose from one of multiple long-standing dermal cylindromas in a 76-year-old man with coexisting trichoepitheliomas and bilateral dermal analogue tumors of the parotid gland. The histologic transition from a benign dermal cylindroma to an anaplastic keratinocytic neoplasm was readily apparent. The malignant dermal cylindroma is a rare neoplasm. To our knowledge, the constellation of benign and malignant dermal cylindromas, multiple trichoepitheliomas, and salivary gland neoplasms has not been previously reported.

  18. Aberrations of dermal connective tissue in patients with cervical artery dissection (sCAD).

    PubMed

    Uhlig, Phillip; Bruckner, Peter; Dittrich, Ralf; Ringelstein, E Bernd; Kuhlenbäumer, Gregor; Hansen, Uwe

    2008-03-01

    Spontaneous cervical artery dissection (sCAD) is a common cause of stroke in patients below 55 years of age. Hereditary connective tissue disorders, including Ehlers-Danlos syndrome type IV, have been associated with sCAD and suprastructural abnormalities of both collagen fibrils and elastic fibers have been found by transmission electron microscopy in the dermis of about 50% of sCAD patients. Here, we investigated dermal connective tissue abnormalities using a novel method. Transmission and immunogold electron microscopy were used to study mechanically generated fragments of dermal matrix suprastructures, in particular collagen fibrils. Analysis of dermal tissue of sCAD patients revealed structurally abnormal collagen fibrils with irregularly contoured surfaces and increased diameters, often associated with a faint or absent banding pattern. Interestingly, only a small number of fibrils displayed short abnormal sections along the length of the fibril. Collagens I and III were present in normal as well as abnormal sections of the fibrils.However, immunogold labeling for the two proteins was strongly increased in abnormal sections.A systematic blinded investigation of skin biopsies of 31 sCAD patients and 17 controls revealed abnormal collagen fibrils in 7 sCAD patients but none of the controls. We conclude that approximately 20% of sCAD patients show collagen fibril alterations, establishing a promising basis for further investigation of connective tissue aberrations in skin biopsies of sCAD patients.

  19. A porcine-derived acellular dermal scaffold that supports soft tissue regeneration: removal of terminal galactose-alpha-(1,3)-galactose and retention of matrix structure.

    PubMed

    Xu, Hui; Wan, Hua; Zuo, Wenqi; Sun, Wendell; Owens, Rick T; Harper, John R; Ayares, David L; McQuillan, David J

    2009-07-01

    Sub-optimal clinical outcomes after implantation of animal-derived tissue matrices may be attributed to the nature of the processing of the material or to an immune response elicited in response to xenogeneic epitopes. The ability to produce a porcine-derived graft that retains the structural integrity of the extracellular matrix and minimizes potential antigenic response to galactose-alpha-(1,3)-galactose terminal disaccharide (alpha-Gal) may allow the scaffold to support regeneration of native tissue. Dermal tissue from wild-type (WT-porcine-derived acellular dermal matrix [PADM]) or Gal-deficient (Gal(-/-) PADM) pigs was processed to remove cells and DNA while preserving the structural integrity of the extracellular matrix. In addition, the WT tissue was subjected to an enzymatic treatment to minimize the presence of alpha-Gal (Gal-reduced PADM). Extracellular matrix composition and integrity was assessed by histological, immunohistochemical (IHC), and ultrastructural analysis. In vivo performance was evaluated by implantation into the abdominal wall of Old World primates in an exisional repair model. Anti-alpha-Gal activity in the serum of monkeys implanted subcutaneously was assessed by ELISA. Minimal modification to the extracellular matrix was assessed by evaluation of intact structure as demonstrated by staining patterns for type I and type VII collagens, laminin, and fibronectin similar to native porcine skin tissues. Explants from the abdominal wall showed evidence of remodeling, notably fibroblast cell repopulation and revascularization, as early as 1 month. Serum ELISA revealed an initial anti-alpha-Gal induction that decreased to baseline levels over time in the primates implanted with WT-PADM, whereas no or minimal anti-Gal activity was detected in the primates implanted with Gal(-/-) PADM or Gal-reduced PADM. The combination of a nondamaging process, successful removal of cells, and reduction of xenogeneic alpha-Gal antigens from the porcine dermal

  20. Fibrillogenesis in Continuously Spun Synthetic Collagen Fiber

    PubMed Central

    Caves, Jeffrey M.; Kumar, Vivek A.; Wen, Jing; Cui, Wanxing; Martinez, Adam; Apkarian, Robert; Coats, Julie E.; Berland, Keith; Chaikof, Elliot L.

    2013-01-01

    The universal structural role of collagen fiber networks has motivated the development of collagen gels, films, coatings, injectables, and other formulations. However, reported synthetic collagen fiber fabrication schemes have either culminated in short, discontinuous fiber segments at unsuitably low production rates, or have incompletely replicated the internal fibrillar structure that dictates fiber mechanical and biological properties. We report a continuous extrusion system with an off-line phosphate buffer incubation step for the manufacture of synthetic collagen fiber. Fiber with a cross-section of 53±14 by 21±3 µm and an ultimate tensile strength of 94±19 MPa was continuously produced at 60 m/hr from an ultrafiltered monomeric collagen solution. The effect of collagen solution concentration, flow rate, and spinneret size on fiber size was investigated. The fiber was further characterized by microdifferential scanning calorimetry, transmission electron microscopy (TEM), second harmonic generation (SHG) analysis, and in a subcutaneous murine implant model. Calorimetry demonstrated stabilization of the collagen triple helical structure, while TEM and SHG revealed a dense, axially aligned D-periodic fibril structure throughout the fiber cross-section. Implantation of glutaraldehyde crosslinked and non-crosslinked fiber in the subcutaneous tissue of mice demonstrated limited inflammatory response and biodegradation after a 6-week implant period. PMID:20024969

  1. Crosslinked hyaluronic acid dermal fillers: a comparison of rheological properties.

    PubMed

    Falcone, Samuel J; Berg, Richard A

    2008-10-01

    Temporary dermal fillers composed of crosslinked hyaluronic acid (XLHA) are space filling gels that are readily available in the United States and Europe. Several families of dermal fillers based on XLHA are now available and here we compare the physical and rheological properties of these fillers to the clinical effectiveness. The XLHA fillers are prepared with different crosslinkers, using HA isolated from different sources, have different particle sizes, and differ substantially in rheological properties. For these fillers, the magnitude of the complex viscosity, |eta*|, varies by a factor of 20, the magnitude of the complex rigidity modulus, |G*|, and the magnitude of the complex compliance, |J*| vary by a factor of 10, the percent elasticity varies from 58% to 89.9%, and the tan delta varies from 0.11 to 0.70. The available clinical data cannot be correlated with either the oscillatory dynamic or steady flow rotational rheological properties of the various fillers. However, the clinical data appear to correlate strongly with the total concentration of XLHA in the products and to a lesser extent with percent elasticity. Hence, our data suggest the following correlation: dermal filler persistence = [polymer] x [% elasticity] and the clinical persistence of a dermal filler composed of XLHA is dominated by the mass and elasticity of the material implanted. This work predicts that the development of future XLHA dermal filler formulations should focus on increasing the polymer concentration and elasticity to improve the clinical persistence.

  2. Dermal Lipogenesis Inhibits Adiponectin Production in Human Dermal Fibroblasts while Exogenous Adiponectin Administration Prevents against UVA-Induced Dermal Matrix Degradation in Human Skin

    PubMed Central

    Fang, Chien-Liang; Huang, Ling-Hung; Tsai, Hung-Yueh; Chang, Hsin-I

    2016-01-01

    Adiponectin is one of the most abundant adipokines from the subcutaneous fat, and regulates multiple activities through endocrine, paracrine, or autocrine mechanisms. However, its expression in adipogenic induced fibroblasts, and the potential role in photoaging has not been determined. Here, human dermal fibroblasts, Hs68, were presented as a cell model of dermal lipogenesis through stimulation of adipogenic differentiation medium (ADM). Similar to other studies in murine pre-adipocyte models (i.e., 3T3-L1), Hs68 fibroblasts showed a tendency to lipogenesis based on lipid accumulation, triglyceride formation, and the expressions of PPAR-γ, lipoprotein lipase (LPL), and FABP4 mRNA. As expected, ADM-treated fibroblasts displayed a reduction on adiponectin expression. Next, we emphasized the photoprotective effects of adiponectin against UVA-induced damage in Hs68 fibroblasts. UVA radiation can downregulate cell adhesion strength and elastic modulus of Hs68 fibroblasts. Moreover, UVA radiation could induce the mRNA expressions of epidermal growth factor receptor (EGFR), adiponectin receptor 1 (AdipoR1), matrix metalloproteinase-1 (MMP-1), MMP-3, and cyclooxygenase-2 (COX-2), but downregulate the mRNA expressions of type I and type III collagen. On the other hand, post-treatment of adiponectin can partially overcome UVA-induced reduction in the cell adhesion strength of Hs68 fibroblasts through the activation of AdipoR1 and the suppression of EGF-R. In addition, post-treatment of adiponectin indicated the increase of type III collagen and elastin mRNA expression and the decrease of MMP-1 and MMP-3 mRNA expression, but a limited degree of recovery of elastic modulus on UVA-irradiated Hs68 fibroblasts. Overall, these results suggest that dermal lipogenesis may inhibit the expression of adiponectin while exogenous adiponectin administration prevents against UVA-induced dermal matrix degradation in Hs68 fibroblasts. PMID:27428951

  3. Dermal Lipogenesis Inhibits Adiponectin Production in Human Dermal Fibroblasts while Exogenous Adiponectin Administration Prevents against UVA-Induced Dermal Matrix Degradation in Human Skin.

    PubMed

    Fang, Chien-Liang; Huang, Ling-Hung; Tsai, Hung-Yueh; Chang, Hsin-I

    2016-01-01

    Adiponectin is one of the most abundant adipokines from the subcutaneous fat, and regulates multiple activities through endocrine, paracrine, or autocrine mechanisms. However, its expression in adipogenic induced fibroblasts, and the potential role in photoaging has not been determined. Here, human dermal fibroblasts, Hs68, were presented as a cell model of dermal lipogenesis through stimulation of adipogenic differentiation medium (ADM). Similar to other studies in murine pre-adipocyte models (i.e., 3T3-L1), Hs68 fibroblasts showed a tendency to lipogenesis based on lipid accumulation, triglyceride formation, and the expressions of PPAR-γ, lipoprotein lipase (LPL), and FABP4 mRNA. As expected, ADM-treated fibroblasts displayed a reduction on adiponectin expression. Next, we emphasized the photoprotective effects of adiponectin against UVA-induced damage in Hs68 fibroblasts. UVA radiation can downregulate cell adhesion strength and elastic modulus of Hs68 fibroblasts. Moreover, UVA radiation could induce the mRNA expressions of epidermal growth factor receptor (EGFR), adiponectin receptor 1 (AdipoR1), matrix metalloproteinase-1 (MMP-1), MMP-3, and cyclooxygenase-2 (COX-2), but downregulate the mRNA expressions of type I and type III collagen. On the other hand, post-treatment of adiponectin can partially overcome UVA-induced reduction in the cell adhesion strength of Hs68 fibroblasts through the activation of AdipoR1 and the suppression of EGF-R. In addition, post-treatment of adiponectin indicated the increase of type III collagen and elastin mRNA expression and the decrease of MMP-1 and MMP-3 mRNA expression, but a limited degree of recovery of elastic modulus on UVA-irradiated Hs68 fibroblasts. Overall, these results suggest that dermal lipogenesis may inhibit the expression of adiponectin while exogenous adiponectin administration prevents against UVA-induced dermal matrix degradation in Hs68 fibroblasts. PMID:27428951

  4. Collagenous gastritis.

    PubMed

    Jin, Xiaoyi; Koike, Tomoyuki; Chiba, Takashi; Kondo, Yutaka; Ara, Nobuyuki; Uno, Kaname; Asano, Naoki; Iijima, Katsunori; Imatani, Akira; Watanabe, Mika; Shirane, Akio; Shimosegawa, Tooru

    2013-09-01

    In the present paper, we report a case of rare collagenous gastritis. The patient was a 25-year-old man who had experienced nausea, abdominal distention and epigastralgia since 2005. Esophagogastroduodenoscopy (EGD) carried out at initial examination by the patient's local doctor revealed an extensively discolored depression from the upper gastric body to the lower gastric body, mainly including the greater curvature, accompanied by residual mucosa with multiple islands and nodularity with a cobblestone appearance. Initial biopsies sampled from the nodules and accompanying atrophic mucosa were diagnosed as chronic gastritis. In August, 2011, the patient was referred to Tohoku University Hospital for observation and treatment. EGD at our hospital showed the same findings as those by the patient's local doctor. Pathological findings included a membranous collagen band in the superficial layer area of the gastric mucosa, which led to a diagnosis of collagenous gastritis. Collagenous gastritis is an extremely rare disease, but it is important to recognize its characteristic endoscopic findings to make a diagnosis. PMID:23363075

  5. [Complications after dermal fillers and their treatment].

    PubMed

    Lemperle, G; Gauthier-Hazan, N; Wolters, M

    2006-12-01

    All dermal fillers are associated with the risk of both early and late complications. Early side effects such as swelling, redness, and bruising occur after intradermal or subdermal injections. The patient has to be aware of these risks and be prepared to accept them. Adverse events that last longer than 2 weeks can be attributable to technical shortcomings (e.g., the implantation of a long-lasting filler substance was too superficial). Such adverse events can be treated with intradermal 5-fluorouracil and steroid injections, vascular lasers, or intense pulsed light, and later with dermabrasion or shaving. Late adverse events also include immunological phenomena such as late-onset allergy and non-allergic foreign body granulomas. Both react well to intralesional steroid injections, which often have to be repeated to establish the right dose. Surgical excisions should remain the last option and are indicated for hard lumps in the lips and visible hard nodules or hard granulomas in the subcutaneous fat.

  6. Evaluation of lymphangiogenesis in acellular dermal matrix

    PubMed Central

    Cherubino, Mario; Pellegatta, Igor; Tamborini, Federico; Cerati, Michele; Sessa, Fausto; Valdatta, Luigi

    2014-01-01

    Introduction: Much attention has been directed towards understanding the phenomena of angiogenesis and lymphangiogenesis in wound healing. Thanks to the manifold dermal substitute available nowadays, wound treatment has improved greatly. Many studies have been published about angiogenesis and cell invasion in INTEGRA®. On the other hand, the development of the lymphatic network in acellular dermal matrix (ADM) is a more obscure matter. In this article, we aim to characterize the different phases of host cell invasion in ADM. Special attention was given to lymphangiogenic aspects. Materials and Methods: Among 57 rats selected to analyse the role of ADM in lymphangiogenesis, we created four groups. We performed an excision procedure on both thighs of these rats: On the left one we did not perform any action except repairing the borders of the wound; while on the right one we used INTEGRA® implant. The excision biopsy was performed at four different times: First group after 7 days, second after 14 days, third after 21 days and fourth after 28 days. For our microscopic evaluation, we used the classical staining technique of haematoxylin and eosin and a semi-quantitative method in order to evaluate cellularity counts. To assess angiogenesis and lymphangiogenesis development we employed PROX-1 Ab and CD31/PECAM for immunohistochemical analysis. Results: We found remarkable wound contraction in defects that healed by secondary intention while minor wound contraction was observed in defects treated with ADM. At day 7, optical microscopy revealed a more plentiful cellularity in the granulation tissue compared with the dermal regeneration matrix. The immunohistochemical process highlighted vascular and lymphatic cells in both groups. After 14 days a high grade of fibrosis was noticeable in the non-treated group. At day 21, both lymphatic and vascular endothelial cells were better developed in the group with a dermal matrix application. At day 28, lymphatic endothelial

  7. Fabrication of duck's feet collagen-silk hybrid biomaterial for tissue engineering.

    PubMed

    Kim, Soo Hyeon; Park, Hae Sang; Lee, Ok Joo; Chao, Janet Ren; Park, Hyun Jung; Lee, Jung Min; Ju, Hyung Woo; Moon, Bo Mi; Park, Ye Ri; Song, Jeong Eun; Khang, Gilson; Park, Chan Hum

    2016-04-01

    Collagen constituting the extracellular matrix has been widely used as biocompatible material for human use. In this study, we have selected duck's feet for extracting collagen. A simple method not utilizing harsh chemical had been employed to extract collagen from duck's feet. We fabricated duck's feet collagen/silk hybrid scaffold for the purpose of modifying the degradation rate of duck's feet collagen. This study suggests that extracted collagen from duck's feet is biocompatible and resembles collagen extracted from porcine which is commercially used. Duck's feet collagen is also economically feasible and it could therefore be a good candidate as a tissue engineering material. Further, addition of silk to fabricate a duck's feet collagen/silk hybrid scaffold could enhance the biostability of duck's feet collagen scaffold. Duck's feet collagen/silk scaffold increased the cell viability compared to silk alone. Animal studies also showed that duck's feet collagen/silk scaffold was more biocompatible than silk alone and more biostable than duck's feet or porcine collagen alone. Additionally, the results revealed that duck's feet collagen/silk hybrid scaffold had high porosity, cell infiltration and proliferation. We suggest that duck's feet collagen/silk hybrid scaffold could be used as a dermal substitution for full thickness skin defects.

  8. Collagen XVII: A Shared Antigen in Neurodermatological Interactions?

    PubMed Central

    2013-01-01

    Collagen XVII is a nonfibril-forming transmembrane collagen, which functions as both a matrix protein and a cell-surface receptor. It is particularly copious in the skin, where it is known to be a structural component of hemidesmosomes. In addition, collagen XVII has been found to be present in the central nervous system, thus offering an explanation for the statistical association between bullous pemphigoid, in which autoimmunity is directed against dermal collagen XVII, and neurological diseases. In support of the hypothesis that collagen XVII serves as a shared antigen mediating an immune response between skin and brain, research on animal and human tissue, as well as numerous epidemiological and case studies, is presented. PMID:23878581

  9. Infection in the Nasal Tip Caused by Acellular Dermal Matrix.

    PubMed

    Lee, Kun Hee

    2015-12-01

    A 19-year-old female patient visited our clinic for rhinoplasty. She complained about her low take-off point, which was apparent in profile view, and wanted slight tip projection. She refused additional cartilage harvesting from ears or ribs but consented to the use of homologous tissue, including acellular dermal matrix, for her dorsum and tip. Septoturbinoplasty was performed, and only a very small amount of septal cartilage could be harvested. It was used as both the columellar strut and the alar rim graft. Nasal dorsum and tip were augmented with acellular dermal matrix. Three months postoperatively, she experienced a few episodes of edema and redness on her nasal tip, followed by pus exudation from the nasal skin. Six months postoperatively, she underwent revision rhinoplasty for removal of inflamed grafts, and onlay tip graft with homologous rib cartilage was performed. Nasal dorsum or tip grafts are an integral part of Asian rhinoplasty. Autogenous tissue is the gold standard for grafting materials. However, the limited availability of autogenous tissue and the preference of patients and surgeons for artificial surgical implants make Asian rhinoplasty challenging. Unavailability of autogenous cartilage and patient refusal of artificial implants led to the use of acellular dermal matrix (ADM) in the nasal dorsum and tip for this case. This is the first report of postoperative complication because of infection rather than absorption after ADM use.

  10. Infection in the Nasal Tip Caused by Acellular Dermal Matrix.

    PubMed

    Lee, Kun Hee

    2015-12-01

    A 19-year-old female patient visited our clinic for rhinoplasty. She complained about her low take-off point, which was apparent in profile view, and wanted slight tip projection. She refused additional cartilage harvesting from ears or ribs but consented to the use of homologous tissue, including acellular dermal matrix, for her dorsum and tip. Septoturbinoplasty was performed, and only a very small amount of septal cartilage could be harvested. It was used as both the columellar strut and the alar rim graft. Nasal dorsum and tip were augmented with acellular dermal matrix. Three months postoperatively, she experienced a few episodes of edema and redness on her nasal tip, followed by pus exudation from the nasal skin. Six months postoperatively, she underwent revision rhinoplasty for removal of inflamed grafts, and onlay tip graft with homologous rib cartilage was performed. Nasal dorsum or tip grafts are an integral part of Asian rhinoplasty. Autogenous tissue is the gold standard for grafting materials. However, the limited availability of autogenous tissue and the preference of patients and surgeons for artificial surgical implants make Asian rhinoplasty challenging. Unavailability of autogenous cartilage and patient refusal of artificial implants led to the use of acellular dermal matrix (ADM) in the nasal dorsum and tip for this case. This is the first report of postoperative complication because of infection rather than absorption after ADM use. PMID:26894006

  11. Extracellular Matrix and Dermal Fibroblast Function in the Healing Wound

    PubMed Central

    Tracy, Lauren E.; Minasian, Raquel A.; Caterson, E.J.

    2016-01-01

    Significance: Fibroblasts play a critical role in normal wound healing. Various extracellular matrix (ECM) components, including collagens, fibrin, fibronectin, proteoglycans, glycosaminoglycans, and matricellular proteins, can be considered potent protagonists of fibroblast survival, migration, and metabolism. Recent Advances: Advances in tissue culture, tissue engineering, and ex vivo models have made the examination and precise measurements of ECM components in wound healing possible. Likewise, the development of specific transgenic animal models has created the opportunity to characterize the role of various ECM molecules in healing wounds. In addition, the recent characterization of new ECM molecules, including matricellular proteins, dermatopontin, and FACIT collagens (Fibril-Associated Collagens with Interrupted Triple helices), further demonstrates our cursory knowledge of the ECM in coordinated wound healing. Critical Issues: The manipulation and augmentation of ECM components in the healing wound is emerging in patient care, as demonstrated by the use of acellular dermal matrices, tissue scaffolds, and wound dressings or topical products bearing ECM proteins such as collagen, hyaluronan (HA), or elastin. Once thought of as neutral structural proteins, these molecules are now known to directly influence many aspects of cellular wound healing. Future Directions: The role that ECM molecules, such as CCN2, osteopontin, and secreted protein, acidic and rich in cysteine, play in signaling homing of fibroblast progenitor cells to sites of injury invites future research as we continue investigating the heterotopic origin of certain populations of fibroblasts in a healing wound. Likewise, research into differently sized fragments of the same polymeric ECM molecule is warranted as we learn that fragments of molecules such as HA and tenascin-C can have opposing effects on dermal fibroblasts. PMID:26989578

  12. Formation of apatite-collagen complexes.

    PubMed

    Doi, Y; Horiguchi, T; Moriwaki, Y; Kitago, H; Kajimoto, T; Iwayama, Y

    1996-05-01

    An apatite-collagen complex was prepared in calcium beta-glycerophosphate solutions at pH 9.0 and 37 degrees C with the purpose of developing new bone substitutes that more closely resemble bone than currently available materials. Reconstituted type I collagen as well as sheet collagen were crosslinked in the presence of alkaline phosphatase and egg-yolk phosvitin. The crosslinked collagens were immersed in daily-renewed calcium beta-glycerophosphate solutions for 2 and 4 weeks to induce the deposition of apatite on the collagen fibers. After 2 weeks of reaction, for example, apatites deposited approximately two times the crosslinked collagen in weight. With reconstituted collagen, the complex showed some elasticity but no apatite was visually observed to detach under deformation with fingers and forceps. The complex, moreover, did not disintegrate when immersed in saline or animal blood. Nevertheless, the complex resorbed with no evidence of cytotoxicity when implanted in muscle tissues. These findings suggest that the apatite-collagen complex prepared would be useful as bone substitutes, especially for periodontal osseous lesion repair and alveolar ridge augmentation. PMID:8731148

  13. Enhancing structural support of the dermal microenvironment activates fibroblasts, endothelial cells, and keratinocytes in aged human skin in vivo.

    PubMed

    Quan, Taihao; Wang, Frank; Shao, Yuan; Rittié, Laure; Xia, Wei; Orringer, Jeffrey S; Voorhees, John J; Fisher, Gary J

    2013-03-01

    The dermal extracellular matrix (ECM) provides strength and resiliency to skin. The ECM consists mostly of type I collagen fibrils, which are produced by fibroblasts. Binding of fibroblasts to collagen fibrils generates mechanical forces, which regulate cellular morphology and function. With aging, collagen fragmentation reduces fibroblast-ECM binding and mechanical forces, resulting in fibroblast shrinkage and reduced function, including collagen production. Here, we report that these age-related alterations are largely reversed by enhancing the structural support of the ECM. Injection of dermal filler, cross-linked hyaluronic acid, into the skin of individuals over 70 years of age stimulates fibroblasts to produce type I collagen. This stimulation is associated with localized increase in mechanical forces, indicated by fibroblast elongation/spreading, and mediated by upregulation of type II TGF-β receptor and connective tissue growth factor. Interestingly, enhanced mechanical support of the ECM also stimulates fibroblast proliferation, expands vasculature, and increases epidermal thickness. Consistent with our observations in human skin, injection of filler into dermal equivalent cultures causes elongation of fibroblasts, coupled with type I collagen synthesis, which is dependent on the TGF-β signaling pathway. Thus, fibroblasts in aged human skin retain their capacity for functional activation, which is restored by enhancing structural support of the ECM.

  14. Clinical Performance of a Dermal Filler Containing Natural Glycolic Acid and a Polylactic Acid Polymer

    PubMed Central

    Macchetto, Pedro Cervantes; Durán Páramo, Rosa Margarita

    2010-01-01

    Lipoatrophy is a condition that affects certain individuals, most commonly those who are infected with the human immunodeficiency virus.1–3 Injectable fillers are used for the treatment of these dermal contour deformities to smooth dermal depressions formed by the loss of volume. These dermal fillers (also known as soft tissue augmentation devices) can correct contour deformities caused by lipoatrophy in patients who are human immunodeficiency virus positive or negative. The product used in this study is a patented, second-generation, injectable, dermal collagen stimulator that combines glycolic acid and polylactic acid. The glycolic acid used is not a polymer, but rather an acid derived from sugar cane. Its chemical structure corresponds to that of an alpha-hydroxy acid. Glycolic acid is a well-characterized agent that is present in a number of cosmetic products. Polylactic acid is a synthetic, biocompatible, biodegradable, inert, synthetic polymer from the poly a-hydroxy-acid family that is believed to stimulate fibroblasts to produce more collagen, thus increasing facial volume. Together, polylactic acid and glycolic acid act in concert to 1) stimulate collagen production and 2) hydrate the outer layers of the skin. A multicenter, clinical investigation authorized by the Mexican Secretariat of Health was conducted between September 20, 2002, and September 19, 2004. This clinical study was conducted in male patients between 32 and 60 years of age with lipoatrophy as a result of highly active antiretroviral therapy for human immunodeficiency virus infection. The study objective was to measure the improvement of contour deformities after the injection of a dermal collagen stimulator containing glycolic acid and polylactic acid. In addition to safety, this dermal filler was assessed when used to correct volume deformities caused by lipoatrophy in subjects who are human immunodeficiency virus positive. Thirty male subjects participated and were treated as follows

  15. Utilizing biologic assimilation of bovine fetal collagen in staged skin grafting.

    PubMed

    Neill, James; James, Kenneth; Lineaweaver, William

    2012-05-01

    Seven patients underwent 2-stage skin grafting with bovine fetal collagen (BFC) as an initial wound cover. Split-thickness skin grafts were successfully placed on the wounds after completion of interval management. BFC proved to be a resilient acellular dermal matrix that could proceed to assimilation and skin grafting under a variety of wound conditions. BFC may prove to be a valuable material, as the role of acellular dermal matrices in skin grafting becomes better defined.

  16. Tenascin-x deficiency mimics ehlers-danlos syndrome in mice through alteration of collagen deposition

    SciTech Connect

    Mao, J.R.; Taylor, G.; Dean, W.B.; Wagner, D.R.; Afzal, V.; Lotz, J.C.; Rubin, E.M.; Bristow, J.

    2002-03-01

    Tenascin-X is a large extracellular matrix protein of unknown function1-3. Tenascin-X deficiency in humans is associated with Ehlers-Danlos syndrome4,5, a generalized connective tissue disorder resulting from altered metabolism of the fibrillar collagens6. Because TNXB is the first Ehlers-Danlos syndrome gene that does not encode a fibrillar collagen or collagen-modifying enzyme7-14, we suggested that tenascin-X might regulate collagen synthesis or deposition15. To test this hypothesis, we inactivated Tnxb in mice. Tnxb-/- mice showed progressive skin hyperextensibility, similar to individuals with Ehlers-Danlos syndrome. Biomechanical testing confirmed increased deformability and reduced tensile strength of their skin. The skin of Tnxb-/- mice was histologically normal, but its collagen content was significantly reduced. At the ultrastructural level, collagen fibrils of Tnxb-/- mice were of normal size and shape, but the density of fibrils in their skin was reduced, commensurate with the reduction in collagen content. Studies of cultured dermal fibroblasts showed that although synthesis of collagen I by Tnxb-/- and wildtype cells was similar, Tnxb-/- fibroblasts failed to deposit collagen I into cell-associated matrix. This study confirms a causative role for TNXB in human Ehlers-Danlos syndrome and suggests that tenascin-X is an essential regulator of collagen deposition by dermal fibroblasts.

  17. Effect of photon energy in collagen generation by interstitial low level laser stimulation

    NASA Astrophysics Data System (ADS)

    Jun, Eunkwon; Ha, Myungjin; Lee, Sangyeob; Radfar, Edalat; Park, Jihoon; Jung, Byungjo

    2015-03-01

    Although the mechanism of low level laser therapy (LLLT) is unclear, many studies demonstrated the positive clinical performance of LLLT for skin rejuvenation. An increase in dermal collagen plays an important role in skin rejuvenation and wound healing. This study aimed to investigate collagen generation after interstitial low level laser stimulation (ILLS). Rabbits were divided into two groups: surfacing irradiation and minimally invasive irradiation. 660nm diode laser of 20mW with 10J, 13J and 15J was applied to the backside of rabbits. Collagen formation was evaluated with ultrasound skin scanner every 12 hours. Results shows that ILLS groups have denser collagen density than surfacing groups.

  18. Implantation of atelocollagen sheet for vocal fold scar

    PubMed Central

    Kishimoto, Yo; Welham, Nathan V.; Hirano, Shigeru

    2011-01-01

    Purpose of review This article reviews recent advances in scaffold-based interventions for the treatment of vocal fold scarring, with a particular emphasis on atelocollagen sheet implantation in the vocal fold lamina propria. Recent findings Scaffold-based therapies have demonstrated therapeutic promise in both pre-clinical and early clinical studies. Recent research has begun to shed light on the interactions between scaffold material properties, encapsulated and infiltrating cells, stimulatory molecules such as growth factors, and external regulatory variables such as stress, strain and vibration. The atelocollagen sheet, a cross-linked collagen material with abundant micropores, has an established clinical track record as a scaffold for dermal and epidermal repair and exhibited potential therapeutic benefit in a recent study of patients with vocal fold scarring and sulcus vocalis. Summary Scaffolding is one of the useful tools in tissue engineering and atelocollagen sheet implantation has shown to be effective in vocal fold regeneration. However, many of the scaffold materials under investigation still await clinical translation, and those that have been investigated in human patients (such as the atelocollagen sheet) require additional research in appropriately powered placebo controlled studies. PMID:20856118

  19. Visualization of dermal alteration in skin lesions with discoid lupus erythematosus by multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Lin, L. H.; Yu, H. B.; Zhu, X. Q.; Zhuo, S. M.; Wang, Y. Y.; Yang, Y. H.; Chen, J. X.

    2013-04-01

    Discoid lupus erythematosus (DLE) is a chronic dermatological disease which lacks valid methods for early diagnosis and therapeutic monitoring. Considering the collagen and elastin disorder due to mucin deposition of DLE, multiphoton microscopy (MPM) imaging techniques were employed to obtain high-resolution collagen and elastin images from the dermis. The content and distribution of collagen and elastin were quantified to characterize the dermal pathological status of skin lesions with DLE in comparison with normal skin. Our results showed a significant difference between skin lesions with DLE and normal skin in terms of the morphological structure of collagen and elastin in the dermis, demonstrating the possibility of MPM for noninvasively tracking the pathological process of DLE even in its early stages and evaluating the therapeutic efficacy at the molecular level.

  20. Differentiation in human amniotic fluid cell cultures: I: Collagen production.

    PubMed Central

    Priest, R E; Priest, J H; Moinuddin, J F; Keyser, A J

    1977-01-01

    The collagen produced by differentiated cells cultured from human amniotic fluid was characterized in two ways. By chain composition and by 4-hydroxyproline:3-hydroxyproline isomer ratio, the collagen synthesized by F-type (fibroblast) cells was indistinguishable from that made by cultured fetal dermal fibroblasts. The predominant cells in young amniotic fluid cultures, termed AF-type, produced collagen with a lower isomer ratio, resembling that of basement membrane collage. The chain composition, as determined by chromatography on carboxymethyl cellulose, varied for different cultures of the AF-type, but the major pattern was consistent with that of basement membrane collagen. On the basis of these characteristics, F cells are of fibroblast origin, whereas most AF cells are of a different origin either endothelial or epithelial. Other evidence (Megaw et al., 1977) suggests an epithelial origin for AF cells. PMID:881704

  1. Chronic UVB-irradiation actuates perpetuated dermal matrix remodeling in female mice: Protective role of estrogen

    PubMed Central

    Röck, Katharina; Joosse, Simon Andreas; Müller, Julia; Heinisch, Nina; Fuchs, Nicola; Meusch, Michael; Zipper, Petra; Reifenberger, Julia; Pantel, Klaus; Fischer, Jens Walter

    2016-01-01

    Chronic UVB-exposure and declined estradiol production after menopause represent important factors leading to extrinsic and intrinsic aging, respectively. Remodeling of the extracellular matrix (ECM) plays a crucial role in both responses. Whether the dermal ECM is able to recover after cessation of UVB-irradiation in dependence of estradiol is not known, however of relevance when regarding possible treatment options. Therefore, the endogenous sex hormone production was depleted by ovariectomy in female mice. Half of the mice received estradiol substitution. Mice were UVB-irradiated for 20 weeks and afterwards kept for 10 weeks without irradiation. The collagen-, hyaluronan- and proteoglycan- (versican, biglycan, lumican) matrix, collagen cleavage products and functional skin parameters were analyzed. The intrinsic aging process was characterized by increased collagen fragmentation and accumulation of biglycan. Chronic UVB-irradiation additionally augmented the lumican, versican and hyaluronan content of the dermis. In the absence of further UVB-irradiation the degradation of collagen and accumulation of biglycan in the extrinsically aged group was perpetuated in an excessive matter. Whereas estradiol increased the proteoglycan content, it reversed the effects of the perpetuated extrinsic response on collagen degradation. Suspension of the intrinsic pathway might therefore be sufficient to antagonize UVB-evoked long-term damage to the dermal ECM. PMID:27460287

  2. Dermal uptake of petroleum substances.

    PubMed

    Jakasa, Ivone; Kezic, Sanja; Boogaard, Peter J

    2015-06-01

    Petroleum products are complex substances comprising varying amounts of linear and branched alkanes, alkenes, cycloalkanes, and aromatics which may penetrate the skin at different rates. For proper interpretation of toxic hazard data, understanding their percutaneous absorption is of paramount importance. The extent and significance of dermal absorption of eight petroleum substances, representing different classes of hydrocarbons, was evaluated. Literature data on the steady-state flux and permeability coefficient of these substances were evaluated and compared to those predicted by mathematical models. Reported results spanned over 5-6 orders of magnitude and were largely dependent on experimental conditions in particular on the type of the vehicle used. In general, aromatic hydrocarbons showed higher dermal absorption than more lipophilic aliphatics with similar molecular weight. The results showed high variation and were largely influenced by experimental conditions emphasizing the need of performing the experiments under "in use" scenario. The predictive models overestimated experimental absorption. The overall conclusion is that, based on the observed percutaneous penetration data, dermal exposure to petroleum hydrocarbons, even of aromatics with highest dermal absorption is limited and highly unlikely to be associated with health risks under real use scenarios.

  3. CosmoDerm/CosmoPlast (human bioengineered collagen) for the aging face.

    PubMed

    Bauman, Leslie

    2004-05-01

    Type 1 collagen loss in the dermis is one of the primary causes of wrinkles seen in aged skin. Dermal fillers using type 1 collagen derived from bioengineered skin are now being used to treat facial wrinkles. These fillers, known by the trade names of CosmoDerm and CosmoPlast, can be used alone or in combination with hyaluronic acid fillers. The benefit of collagen-based dermal fillers is decreased downtime, decreased bruising, decreased pain on injection, and the ability to return lost structural components to aged skin. Many aesthetic physicians are beginning to use collagen- and hyaluronic-containing fillers in combination to replace both of these natural components of the skin that are lost during the aging process.

  4. Ovine-Based Collagen Matrix Dressing: Next-Generation Collagen Dressing for Wound Care

    PubMed Central

    Bohn, Gregory; Liden, Brock; Schultz, Gregory; Yang, Qingping; Gibson, Daniel J.

    2016-01-01

    Significance: Broad-spectrum metalloproteinase (MMP) reduction along with inherent aspects of an extracellular matrix (ECM) dressing can bring about improved wound healing outcomes and shorter treatment duration. Initial reports of clinical effectiveness of a new ovine-based collagen extracellular matrix (CECM) dressing demonstrate benefits in chronic wound healing. Recent Advances: CECM dressings are processed differently than oxidized regenerated cellulose/collagen dressings. CECM dressings consist primarily of collagens I and III arranged as native fibers that retain the three-dimensional architecture present in tissue ECM. As such, ovine-based ECM dressings represent a new generation of collagen dressings capable of impacting a broad spectrum of MMP excess known to be present in chronic wounds. Critical Issues: While MMPs are essential in normal healing, elevated presence of MMPs has been linked to wound failure. Collagen has been shown to reduce levels of MMPs, acting as a sacrificial substrate for excessive proteases in a chronic wound. Preserving collagen dressings in a more native state enhances bioactivity in terms of the ability to affect the chronic wound environment. Clinical observation and assessment may not be sufficient to identify a wound with elevated protease activity that can break down ECM, affect wound fibroblasts, and impair growth factor response. Future Directions: Collagen dressings that target broad-spectrum excessive MMP levels and can be applied early in the course of care may positively impact healing rates in difficult wounds. Next-generation collagen dressings offer broader MMP reduction capacity while providing a provisional dermal matrix or ECM. PMID:26858910

  5. Red blood cell lysate modulates the expression of extracellular matrix proteins in dermal fibroblasts.

    PubMed

    Akbari, Amir; Li, Yunyuan; Kilani, Ruhangiz T; Ghahary, Aziz

    2012-11-01

    During the early stage of wound healing process, blood clots can be served as a temporary extracellular matrix (ECM) to let skin cell migration and proliferation. The red blood cells are generally thought as inert bystanders in the early and inflammatory phase of wound healing. Here, we provide evidence that red blood cells (RBC) also play an important role in modulation of key ECM components such as type-I collagen, α-smooth muscle actin, fibronectin, and matrix metalloproteinases (MMPs). In this study, we used western blot analysis and showed a significant increase in the level of MMP-1, 2, 3. Furthermore, we found that RBC lysate significantly down-regulates type-I collagen and α-smooth muscle actin while up-regulates fibronectin expression in dermal fibroblasts. To further explore the mechanism by which RBC lysate modulates MMP-1 expression, the effect of inhibitors for three MAPK signaling pathways on RBC inducing MMP-1 expression by dermal fibroblasts were tested. The result showed that the inhibitor of ERK1/2 could abrogate the stimulatory effect of RBC lysate on MMP-1 expression in dermal fibroblasts. Consistently, RBC treatment results in an increase of ERK1/2 phosphorylation in dermal fibroblast. In conclusion, these findings suggest that RBC lysate can modulate the expression of MMPs and key ECM components which are important in healing process.

  6. Quantitative analysis of intrinsic skin aging in dermal papillae by in vivo harmonic generation microscopy

    PubMed Central

    Liao, Yi-Hua; Kuo, Wei-Cheng; Chou, Sin-Yo; Tsai, Cheng-Shiun; Lin, Guan-Liang; Tsai, Ming-Rung; Shih, Yuan-Ta; Lee, Gwo-Giun; Sun, Chi-Kuang

    2014-01-01

    Chronological skin aging is associated with flattening of the dermal-epidermal junction (DEJ), but to date no quantitative analysis focusing on the aging changes in the dermal papillae (DP) has been performed. The aim of the study is to determine the architectural changes and the collagen density related to chronological aging in the dermal papilla zone (DPZ) by in vivo harmonic generation microscopy (HGM) with a sub-femtoliter spatial resolution. We recruited 48 Asian subjects and obtained in vivo images on the sun-protected volar forearm. Six parameters were defined to quantify 3D morphological changes of the DPZ, which we analyzed both manually and computationally to study their correlation with age. The depth of DPZ, the average height of isolated DP, and the 3D interdigitation index decreased with age, while DP number density, DP volume, and the collagen density in DP remained constant over time. In vivo high-resolution HGM technology has uncovered chronological aging-related variations in DP, and sheds light on real-time quantitative skin fragility assessment and disease diagnostics based on collagen density and morphology. PMID:25401037

  7. A Hydrogel Derived From Decellularized Dermal Extracellular Matrix

    PubMed Central

    Wolf, Matthew T.; Daly, Kerry A.; Brennan-Pierce, Ellen P.; Johnson, Scott A.; Carruthers, Christopher; D’Amore, Antonio; Nagarkar, Shailesh P.; Velankar, Sachin S.; Badylak, Stephen F.

    2012-01-01

    The ECM of mammalian tissues has been used as a scaffold to facilitate the repair and reconstruction of numerous tissues. Such scaffolds are prepared in many forms including sheets, powders, and hydrogels. ECM hydrogels provide advantages such as injectability, the ability to fill an irregularly shaped space, and the inherent bioactivity of native matrix. However, material properties of ECM hydrogels and the effect of these properties upon cell behavior are neither well understood nor controlled. The objective of this study was to prepare and determine the structure, mechanics, and the cell response in vitro and in vivo of ECM hydrogels prepared from decellularized porcine dermis and urinary bladder tissues. Dermal ECM hydrogels were characterized by a more dense fiber architecture and greater mechanical integrity than urinary bladder ECM hydrogels, and showed a dose dependent increase in mechanical properties with ECM concentration. In vitro, dermal ECM hydrogels supported greater C2C12 myoblast fusion, and less fibroblast infiltration and less fibroblast mediated hydrogel contraction than urinary bladder ECM hydrogels. Both hydrogels were rapidly infiltrated by host cells, primarily macrophages, when implanted in a rat abdominal wall defect. Both ECM hydrogels degraded by 35 days in vivo, but UBM hydrogels degraded more quickly, and with greater amounts of myogenesis than dermal ECM. These results show that ECM hydrogel properties can be varied and partially controlled by the scaffold tissue source, and that these properties can markedly affect cell behavior. PMID:22789723

  8. Changes of skin collagen orientation associated with chronological aging as probed by polarized-FTIR micro-imaging.

    PubMed

    Nguyen, The Thuong; Eklouh-Molinier, Christophe; Sebiskveradze, David; Feru, Jezabel; Terryn, Christine; Manfait, Michel; Brassart-Pasco, Sylvie; Piot, Olivier

    2014-05-21

    During chronological skin aging, alterations in dermal structural proteins cause morphological modifications. Modifications are probably due to collagen fiber (type I collagen) rearrangement and reorientation with aging that have not been researched until now. FTIR microspectroscopy appears as an interesting method to study protein structure under normal and pathological conditions. Associated with a polarizer, this vibrational technique permits us to probe collagen orientation within skin tissue sections, by computing the ratio of integrated intensities of amide I and amide II bands. In this study, we used the polarized-FTIR imaging to evaluate molecular modifications of dermal collagen during chronological aging. The data processing of polarized infrared data revealed that type I collagen fibers become parallel to the skin surface in aged skin dermis. Our approach could find innovative applications in dermatology as well as in cosmetics.

  9. The use of human sweat gland-derived stem cells for enhancing vascularization during dermal regeneration.

    PubMed

    Danner, Sandra; Kremer, Mathias; Petschnik, Anna Emilia; Nagel, Sabine; Zhang, Ziyang; Hopfner, Ursula; Reckhenrich, Ann K; Weber, Caroline; Schenck, Thilo L; Becker, Tim; Kruse, Charli; Machens, Hans-Günther; Egaña, José T

    2012-06-01

    Vascularization is a key process in tissue engineering and regeneration and represents one of the most important issues in the field of regenerative medicine. Thus, several strategies to improve vascularization are currently under clinical evaluation. In this study, stem cells derived from human sweat glands were isolated, characterized, seeded in collagen scaffolds, and engrafted in a mouse full skin defect model for dermal regeneration. Results showed that these cells exhibit high proliferation rates and express stem cell and differentiation markers. Moreover, cells responded to angiogenic environments by increasing their migration (P<0.001) and proliferation (P<0.05) capacity and forming capillary-like structures. After seeding in the scaffolds, cells distributed homogeneously, interacting directly with the scaffold, and released bioactive molecules involved in angiogenesis, immune response, and tissue remodeling. In vivo, scaffolds containing cells were used to induce dermal regeneration. Here we have found that the presence of the cells significantly improved vascularization (P<0.001). As autologous sweat gland-derived stem cells are easy to obtain, exhibit a good proliferation capacity, and improve vascularization during dermal regeneration, we suggest that the combined use of sweat gland-derived stem cells and scaffolds for dermal regeneration might improve dermal regeneration in future clinical settings.

  10. Effect of Silicone on the Collagen Fibrillogenesis and Stability

    PubMed Central

    Kadziński, Leszek; Prokopowicz, Magdalena; Jakóbkiewicz-Banecka, Joanna; Gabig-Cimińska, Magdalena; Łukasiak, Jerzy; Banecki, Bogdan

    2015-01-01

    Collagen, the most abundant protein in mammals, is able to form fibrils, which have central role in tissue repair, fibrosis, and tumor invasion. As a component of skin, tendons, and cartilages, this protein contacts with any implanted materials. An inherent problem associated with implanted prostheses is their propensity to be coated with host proteins shortly after implantation. Also, silicone implants undergoing relatively long periods of contact with blood can lead to formation of thrombi and emboli. In this paper, we demonstrate the existence of interactions between siloxanes and collagen. Low-molecular-weight cyclic siloxane (hexamethylcyclotrisiloxane—D3) and polydimethylsiloxanes (PDMS) forming linear chains, ranging in viscosity from 20 to 12,000 cSt, were analyzed. We show that D3 as well as short-chain PDMS interact with collagen, resulting in a decrease in fibrillogenesis. However, loss of collagen native structure does not occur because of these interactions. Rather, collagen seems to be sequestered in its native form in an interlayer formed by collagen–siloxane complexes. On the other hand, silicone molecules with longer chains (i.e., PDMS with viscosity of 1000 and 12,000 cSt, the highest viscosity analyzed here) demonstrate little interaction with this protein and do not seem to affect collagen activity. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1275–1281, 2015 PMID:25589402

  11. [Complications after dermal fillers and their treatment].

    PubMed

    Lemperle, G; Gauthier-Hazan, N; Wolters, M

    2006-12-01

    All dermal fillers are associated with the risk of both early and late complications. Early side effects such as swelling, redness, and bruising occur after intradermal or subdermal injections. The patient has to be aware of these risks and be prepared to accept them. Adverse events that last longer than 2 weeks can be attributable to technical shortcomings (e.g., the implantation of a long-lasting filler substance was too superficial). Such adverse events can be treated with intradermal 5-fluorouracil and steroid injections, vascular lasers, or intense pulsed light, and later with dermabrasion or shaving. Late adverse events also include immunological phenomena such as late-onset allergy and non-allergic foreign body granulomas. Both react well to intralesional steroid injections, which often have to be repeated to establish the right dose. Surgical excisions should remain the last option and are indicated for hard lumps in the lips and visible hard nodules or hard granulomas in the subcutaneous fat. PMID:17219319

  12. Collagen vascular disease

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/001223.htm Collagen vascular disease To use the sharing features on ... were previously said to have "connective tissue" or "collagen vascular" disease. We now have names for many ...

  13. Generation of a Functional Non-Shedding Collagen XVII Mouse Model: Relevance of Collagen XVII Shedding in Wound Healing.

    PubMed

    Jacków, Joanna; Schlosser, Andreas; Sormunen, Raija; Nyström, Alexander; Sitaru, Cassian; Tasanen, Kaisa; Bruckner-Tuderman, Leena; Franzke, Claus-Werner

    2016-02-01

    Collagen XVII is a hemidesmosomal anchorage molecule of basal keratinocytes that promotes stable epidermal-dermal adhesion. One unique feature of collagen XVII is that its collagenous ectodomain is constitutively released from the cell surface by a disintegrin and metalloproteinases (ADAMs) through cleavage within its juxtamembranous linker domain. The responsivity of shedding to environmental stimuli and the high stability of the released ectodomain in several tissues suggests functions in cell detachment during epidermal morphogenesis, differentiation, and regeneration, but its physiologic relevance remained elusive. To investigate this, we generated knock-in mice, which express a functional non-sheddable collagen XVII mutant, with a 41 amino acid deletion in the linker domain spanning all ADAM cleavage sites. These mice showed no macroscopic phenotypic changes, were fertile, and had a normal lifespan. Prevention of collagen XVII shedding interfered neither with skin development nor with epidermal adhesion and differentiation. However, it led to faster wound closure due to accelerated re-epithelialization at the wound edges where shedding of wild-type collagen XVII was strongly induced. Taken together, we have successfully generated a functional non-shedding collagen XVII mouse model, which represents a powerful tool to investigate the pathophysiologic relevance of ectodomain shedding during wound regeneration and cancer invasion. PMID:26967482

  14. Generation of a Functional Non-Shedding Collagen XVII Mouse Model: Relevance of Collagen XVII Shedding in Wound Healing.

    PubMed

    Jacków, Joanna; Schlosser, Andreas; Sormunen, Raija; Nyström, Alexander; Sitaru, Cassian; Tasanen, Kaisa; Bruckner-Tuderman, Leena; Franzke, Claus-Werner

    2016-02-01

    Collagen XVII is a hemidesmosomal anchorage molecule of basal keratinocytes that promotes stable epidermal-dermal adhesion. One unique feature of collagen XVII is that its collagenous ectodomain is constitutively released from the cell surface by a disintegrin and metalloproteinases (ADAMs) through cleavage within its juxtamembranous linker domain. The responsivity of shedding to environmental stimuli and the high stability of the released ectodomain in several tissues suggests functions in cell detachment during epidermal morphogenesis, differentiation, and regeneration, but its physiologic relevance remained elusive. To investigate this, we generated knock-in mice, which express a functional non-sheddable collagen XVII mutant, with a 41 amino acid deletion in the linker domain spanning all ADAM cleavage sites. These mice showed no macroscopic phenotypic changes, were fertile, and had a normal lifespan. Prevention of collagen XVII shedding interfered neither with skin development nor with epidermal adhesion and differentiation. However, it led to faster wound closure due to accelerated re-epithelialization at the wound edges where shedding of wild-type collagen XVII was strongly induced. Taken together, we have successfully generated a functional non-shedding collagen XVII mouse model, which represents a powerful tool to investigate the pathophysiologic relevance of ectodomain shedding during wound regeneration and cancer invasion.

  15. Measuring the strength of dermal fibroblast attachment to functionalized titanium alloys in vitro.

    PubMed

    Pendegrass, Catherine J; Middleton, Claire A; Gordon, David; Jacob, Josh; Blunn, Gordon W

    2010-03-01

    The success of intraosseous transcutaneous amputation prostheses (ITAP) relies on soft tissue attachment to prevent infection which leads to implant failure. Fibronectin (Fn) has been shown to enhance dermal fibroblast attachment in vitro, however measurement of cell attachment strength has been indirect; using cell area and immunolocalization of focal adhesion components. In this study, we have developed a flow apparatus to assess the biophysical strength of cell attachment to biomaterials used in ITAP. We have demonstrated that dermal fibroblast attachment strength increases significantly up to 96 h and that data from direct and indirect methods of assessing cell attachment strength have a significant positive correlation. Additionally, we have used direct and indirect assessment methods to demonstrate that dermal fibroblast attachment strength is significantly greater on fibronectin-coated titanium alloy compared with uncoated controls at 1, 4, and 24 hours.

  16. Dermal fillers and combinations of fillers for facial rejuvenation.

    PubMed

    Beer, Kenneth

    2009-10-01

    Until recently, the use of dermal fillers was limited in the United States by the small number of products approved by the Food and Drug Administration. The products now approved for use in the United States have opened up the range of possibilities for combinations of products that are synergistic in their effects. Combinations of products may be discussed in temporal or anatomic relationships. Temporal combinations refer to the use of different fillers at different times, whereas anatomic combinations refer to the use of different fillers in different parts of the face. Before discussing how the various fillers may be used in combination, it is worthwhile to consider their use in isolation. Soft-tissue augmentation products under consideration in the present article include the hyaluronic acids (HA), poly L lactic acid (PLLA), calcium hydroxylapatite (CAHA), porcine collagen, and silicone.

  17. Primary cutaneous dermal mucinosis on herpes zoster scars.

    PubMed

    Camacho, Diana; Feltes, Federico; Machán, Salma; Pielasinski, Úrsula; Fariña, María C; Gavin, Eduardo; Requena, Luis

    2016-07-01

    The term isotopic response refers to the appearance of a new skin disease at the site of another unrelated and already healed skin disorder. Often, the first disease is herpes zoster (HZ). Several cutaneous reactions have been described in a dermatome recently affected by HZ. We present the case of a 33-year-old man who developed whitish papules with a zosteriform distribution on HZ scars. Histopathologic study with hematoxylin and eosin and Alcian blue (pH 2.5) staining demonstrated abundant deposits of mucin interstitially arranged between collagen bundles of the papillary dermis. Cutaneous dermal mucinosis as a postherpetic isotopic response is rare, but it should be added to the list of cutaneous reactions arising in HZ scars. PMID:27529717

  18. Complications of collagenous colitis.

    PubMed

    Freeman, Hugh-James

    2008-03-21

    Microscopic forms of colitis have been described, including collagenous colitis. This disorder generally has an apparently benign clinical course. However, a number of gastric and intestinal complications, possibly coincidental, may develop with collagenous colitis. Distinctive inflammatory disorders of the gastric mucosa have been described, including lymphocytic gastritis and collagenous gastritis. Celiac disease and collagenous sprue (or collagenous enteritis) may occur. Colonic ulceration has been associated with use of nonsteroidal anti-inflammatory drugs, while other forms of inflammatory bowel disease, including ulcerative colitis and Crohn's disease, may evolve from collagenous colitis. Submucosal "dissection", colonic fractures or mucosal tears and perforation from air insufflation during colonoscopy may occur and has been hypothesized to be due to compromise of the colonic wall from submucosal collagen deposition. Similar changes may result from increased intraluminal pressure during barium enema contrast studies. Finally, malignant disorders have also been reported, including carcinoma and lymphoproliferative disease. PMID:18350593

  19. Vegetable peptones increase production of type I collagen in human fibroblasts by inducing the RSK-CCAAT/enhancer binding protein-β phosphorylation pathway.

    PubMed

    Jung, Eunsun; Cho, Jae Youl; Park, Deokhoon; Kim, Min Hee; Park, Beomseok; Lee, Sang Yeol; Lee, Jongsung

    2015-02-01

    Skin aging appears to be principally attributed to a decrease in type I collagen level and the regeneration ability of dermal fibroblasts. We hypothesized that vegetable peptones promote cell proliferation and production of type I collagen in human dermal fibroblasts. Therefore, we investigated the effects of vegetable peptones on cell proliferation and type I collagen production and their possible mechanisms in human dermal fibroblasts. Vegetable peptones significantly promoted cell proliferation in a concentration-dependent manner. In addition, the human luciferase type I collagen α2 promoter and type I procollagen synthesis assays showed that the vegetable peptones induced type I procollagen production by activating the type I collagen α2 promoter. Moreover, the vegetable peptones activated p90 ribosomal s6 kinase, which was mediated by activating the Raf-p44/42 mitogen-activated protein kinase signaling pathway. Furthermore, the vegetable peptone-induced increase in cell proliferation and type I collagen production decreased upon treatment with the ERK inhibitor PD98059. Taken together, these findings suggest that increased proliferation of human dermal fibroblasts and enhanced production of type I collagen by vegetable peptones occur primarily by inducing the p90 ribosomal s6 kinase-CCAAT/enhancer binding protein β phosphorylation pathway, which is mediated by activating Raf-ERK signaling.

  20. Differentiation of human umbilical cord mesenchymal stem cells into dermal fibroblasts in vitro

    SciTech Connect

    Han, Yanfu; Chai, Jiake; Sun, Tianjun; Li, Dongjie; Tao, Ran

    2011-10-07

    Highlights: {yields} Mesenchymal stem cells (MSCs) are potential seed cells for tissue-engineered skin. {yields} Tissue-derived umbilical cord MSCs (UCMSCs) can readily be isolated in vitro. {yields} We induce UCMSCs to differentiate into dermal fibroblasts via conditioned medium. {yields} Collagen type I and collagen type III mRNA level was higher in differentiated cells. {yields} UCMSCs-derived fibroblast-like cells strongly express fibroblast-specific protein. -- Abstract: Tissue-derived umbilical cord mesenchymal stem cells (UCMSCs) can be readily obtained, avoid ethical or moral constraints, and show excellent pluripotency and proliferation potential. UCMSCs are considered to be a promising source of stem cells in regenerative medicine. In this study, we collected newborn umbilical cord tissue under sterile conditions and isolated UCMSCs through a tissue attachment method. UCMSC cell surface markers were examined using flow cytometry. On the third passage, UCMSCs were induced to differentiate into dermal fibroblasts in conditioned induction media. The induction results were detected using immunofluorescence with a fibroblast-specific monoclonal antibody and real time PCR for type I and type III collagen. UCMSCs exhibited a fibroblast-like morphology and reached 90% confluency 14 to 18 days after primary culture. Cultured UCMSCs showed strong positive staining for CD73, CD29, CD44, CD105, and HLA-I, but not CD34, CD45, CD31, or HLA-DR. After differentiation, immunostaining for collagen type I, type III, fibroblast-specific protein, vimentin, and desmin were all strongly positive in induced cells, and staining was weak or negative in non-induced cells; total transcript production of collagen type I and collagen type III mRNA was higher in induced cells than in non-induced cells. These results demonstrate that UCMSCs can be induced to differentiate into fibroblasts with conditioned induction media and, in turn, could be used as seed cells for tissue

  1. [Cutaneous myxoma (focal dermal mucinosis)].

    PubMed

    Senff, H; Kuhlwein, A; Jänner, M; Schäfer, R

    1988-09-01

    Two cases of cutaneous myxoma are presented. In case 1 the cutaneous myxoma was localized on the left thumb and clinically resembled a pyogenic granuloma. In case 2 it was found at the left nipple. The benign cutaneous tumor may herald a cardiac myxoma and other conditions. Thus, a cutaneous myxoma should be accepted as an indication for thorough investigation of the whole body at regular intervals. As there are neither clinically nor histologically adequate criteria for differentiation, cutaneous myxoma and focal dermal mucinosis can be considered as variants of a single entity.

  2. Dermal fillers: facts and controversies.

    PubMed

    Wollina, Uwe; Goldman, Alberto

    2013-01-01

    Dermal fillers have been used for decades in soft tissue augmentation. Currently, filler implementation is among the most common minimally invasive procedures for rejuvenation and body sculpturing. There is a broad variety of filler materials and products. Despite immense experience, a number of controversies in this topic exist. Some of these controversies are addressed in this review, for example, who should perform filler injections, the difference between permanent and nonpermanent fillers, the off-label use of liquid silicone, and the role of pain reduction. Implementation of guidelines and restriction of filler use by trained physicians can improve safety for patients.

  3. Differentiation within autologous fibrin scaffolds of porcine dermal cells with the mesenchymal stem cell phenotype.

    PubMed

    de la Puente, Pilar; Ludeña, Dolores; López, Marta; Ramos, Jennifer; Iglesias, Javier

    2013-02-01

    Porcine mesenchymal stem cells (pMSCs) are an attractive source of cells for tissue engineering because their properties are similar to those of human stem cells. pMSCs can be found in different tissues but their dermal origin has not been studied in depth. Additionally, MSCs differentiation in monolayer cultures requires subcultured cells, and these cells are at risk of dedifferentiation when implanting them into living tissue. Following this, we attempted to characterize the MSCs phenotype of porcine dermal cells and to evaluate their cellular proliferation and differentiation in autologous fibrin scaffolds (AFSs). Dermal biopsies and blood samples were obtained from 12 pigs. Dermal cells were characterized by flow cytometry. Frozen autologous plasma was used to prepare AFSs. pMSC differentiation was studied in standard structures (monolayers and pellets) and in AFSs. The pMSCs expressed the CD90 and CD29 markers of the mesenchymal lineage. AFSs afforded adipogenic, osteogenic and chondrogenic differentiation. The porcine dermis can be proposed to be a good source of MSCs with adequate proliferative capacity and a suitable expression of markers. The pMSCs also showed optimal proliferation and differentiation in AFSs, such that these might serve as a promising autologous and implantable material for use in tissue engineering.

  4. Type II achondrogenesis-hypochondrogenesis: identification of abnormal type II collagen.

    PubMed

    Godfrey, M; Hollister, D W

    1988-12-01

    We have extended the study of a mild case of type II achondrogenesis-hypochondrogenesis to include biochemical analyses of cartilage, bone, and the collagens produced by dermal fibroblasts. Type I collagen extracted from bone and types I and III collagen produced by dermal fibroblasts were normal, as was the hexosamine ratio of cartilage proteoglycans. Hyaline cartilage, however, contained approximately equal amounts of types I and II collagen and decreased amounts of type XI collagen. Unlike the normal SDS-PAGE mobility. Two-dimensional SDS-PAGE revealed extensive overmodification of all type II cyanogen bromide peptides in a pattern consistent with heterozygosity for an abnormal pro alpha 1(II) chain which impaired the assembly and/or folding of type II collagen. This interpretation implies that dominant mutations of the COL2A1 gene may cause type II achondrogenesis-hypochondrogenesis. More generally, emerging data implicating defects of type II collagen in the type II achondrogenesis-hypochondrogenesis-spondyloepiphyseal dysplasia congenita spectrum and in the Kniest-Stickler syndrome spectrum suggest that diverse mutations of this gene may be associated with widely differing phenotypic outcome. PMID:3195588

  5. Resorbable dome device and guided bone regeneration: an alternative bony defect treatment around implants. A case series.

    PubMed

    Parma-Benfenati, Stefano; Roncati, Marisa; Galletti, Primo; Tinti, Carlo

    2014-01-01

    This case series presents the use of a resorbable "dome device" made of a slow, long-lasting resorbable suturing material to support the barrier creating and maintaining a secluded space to promote bone regeneration. Acellular dermal matrix or cross-linked resorbable collagen membrane, as barriers, combined with mineralized freeze-dried bone allograft, with simultaneous implant placement, were utilized in reconstructing non-space-making defects. Eight implants in six healthy patients were treated with a combination of these resorbable regenerative materials. Only one of seven was treated with a nonsubmerged approach. All sites remained completely covered and no implant exposure occurred during healing. At the 9- to 24-month reentry surgeries, the clinical bone density was equivalent to that of the native bone and the mean number of final exposed threads was 0.5. The mean buccal bone thickness achieved was 3.12 mm, with a mean total coverage of exposed threads in approximately 87.5% of the cases.

  6. Patient safety considerations regarding dermal filler injections.

    PubMed

    Jones, Jill K

    2006-01-01

    Today's population is seeking procedures that enhance or improve its appearance, that require little or no downtime, and that provide immediate results. Dermal filler injections are among the top five procedures performed for this purpose. Patient safety must remain the ultimate goal of any practitioner delivering such procedures. This column will examine pertinent safety considerations in relation to the delivery of dermal filler injections.

  7. Cell therapy for full-thickness wounds: are fetal dermal cells a potential source?

    PubMed

    Akershoek, J J; Vlig, M; Talhout, W; Boekema, B K H L; Richters, C D; Beelen, R H J; Brouwer, K M; Middelkoop, E; Ulrich, M M W

    2016-04-01

    The application of autologous dermal fibroblasts has been shown to improve burn wound healing. However, a major hurdle is the availability of sufficient healthy skin as a cell source. We investigated fetal dermal cells as an alternative source for cell-based therapy for skin regeneration. Human (hFF), porcine fetal (pFF) or autologous dermal fibroblasts (AF) were seeded in a collagen-elastin substitute (Novomaix, NVM), which was applied in combination with an autologous split thickness skin graft (STSG) to evaluate the effects of these cells on wound healing in a porcine excisional wound model. Transplantation of wounds with NVM+hFF showed an increased influx of inflammatory cells (e.g., neutrophils, macrophages, CD4(+) and CD8(+) lymphocytes) compared to STSG, acellular NVM (Acell-NVM) and NVM+AF at post-surgery days 7 and/or 14. Wounds treated with NVM+pFF presented only an increase in CD8(+) lymphocyte influx. Furthermore, reduced alpha-smooth muscle actin (αSMA) expression in wound areas and reduced contraction of the wounds was observed with NVM+AF compared to Acell-NVM. Xenogeneic transplantation of NVM+hFF increased αSMA expression in wounds compared to NVM+AF. An improved scar quality was observed for wounds treated with NVM+AF compared to Acell-NVM, NVM+hFF and NVM+pFF at day 56. In conclusion, application of autologous fibroblasts improved the overall outcome of wound healing in comparison to fetal dermal cells and Acell-NVM, whereas application of fetal dermal fibroblasts in NVM did not improve wound healing of full-thickness wounds in a porcine model. Although human fetal dermal cells demonstrated an increased immune response, this did not seem to affect scar quality.

  8. Pioneering technique using Acellular Dermal Matrix in the rescue of a radiation ulcer

    PubMed Central

    NASEEM, S.; PATEL, A.D.; DEVALIA, H.

    2016-01-01

    Background Radiotherapy as an adjuvant to mastectomy is integral to the treatment of breast cancer, but can result in skin ulceration. Skin ulceration following radiotherapy is traditionally managed by removing the implant and allowing the skin to heal by secondary intention. Case report A 42-year-old woman underwent radiotherapy following a breast reconstruction. She developed a 2 x 3cm radiation ulcer. The ulcer was managed by removing the implant and performing capsulectomy. A Beckers 50 expander was placed and reinforced with acellular dermal matrix inferolaterally. At follow-up the patient had a good cosmetic outcome. Conclusion Post-radiation skin ulcers present a challenge to treat with no current standardised management. The use of acellular dermal matrix may present a new technique to promote healing in these testing cases. PMID:27142826

  9. The nano-scale mechanical properties of the extracellular matrix regulate dermal fibroblast function.

    PubMed

    Achterberg, Volker F; Buscemi, Lara; Diekmann, Heike; Smith-Clerc, Josiane; Schwengler, Helge; Meister, Jean-Jacques; Wenck, Horst; Gallinat, Stefan; Hinz, Boris

    2014-07-01

    Changes in the mechanical properties of dermis occur during skin aging or tissue remodeling and affect the activity of resident fibroblasts. With the aim to establish elastic culture substrates that reproduce the variable softness of dermis, we determined Young's elastic modulus E of human dermis at the cell perception level using atomic force microscopy. The E of dermis ranged from 0.1 to 10 kPa, varied depending on body area and dermal layer, and tended to increase with age in 26-55-year-old donors. The activation state of human dermal fibroblasts cultured on "skin-soft" E (5 kPa) silicone culture substrates was compared with stiff plastic culture (GPa), collagen gel cultures (0.1-9 kPa), and fresh human dermal tissue. Fibroblasts cultured on skin-soft silicones displayed low mRNA levels of fibrosis-associated genes and increased expression of the matrix metalloproteinases (MMPs) MMP-1 and MMP-3 as compared with collagen gel and plastic cultures. The activation profile exhibited by fibroblasts on "skin-soft" silicone culture substrates was most comparable with that of human dermis than any other tested culture condition. Hence, providing biomimetic mechanical conditions generates fibroblasts that are more suitable to investigate physiologically relevant cell processes than fibroblasts spontaneously activated by stiff conventional culture surfaces.

  10. The fine structure of the developing pelvic fin dermal skeleton in the trout Salmo gairdneri.

    PubMed

    Géraudie, J; Landis, W J

    1982-02-01

    The morphogenetic and ultrastructural features of the dermal skeleton in the pelvic fin bud of a teleost, the rainbow trout Salmo gairdneri, have been examined by light and electron microscopy. The principal structural components observed are lepidotrichia and actinotrichia. Lepidotrichia consist of two parallel and symmetrical bony demirays that form jointed segments within the fin. The demirays calcify in a proximodistal direction within the extracellular collagen network of the basal lamella belonging to the epidermal-dermal interface of the fin. Needle- and plate-like particles of a solid mineral phase appear to be associated with the collagen fibrils and with a fine, granular, interfibrillar material central to the demirays. Cellular processes and membrane-bound vesicles are absent from the regions of calcification. During fin growth, the bony, acellular lepidotrichia are separated from the epidermal-dermal interface by infiltrating mesenchymal cells in proximal fin regions; in distal areas, the lepidotrichia remain within the basal lamella. The actinotrichia are extensive unmineralized rods of elastoidin that occupy the distal margin of the fin and precede the differentiation of lepidotrichia. Once the lepidotrichia form, actinotrichia lie preferentially between their demirays. In some instances, structural interactions are suggested between actinotrichia and lepidotrichia. Considerations of embryologic and structural features of fin components fail to support the hypothesis that individual segments of lepidotrichia are modified scales in all fish. PMID:7072614

  11. Laminin modified infection-preventing collagen membrane containing silver sulfadiazine-hyaluronan microparticles.

    PubMed

    Lee, Jong-Eun; Park, Jong-Chul; Lee, Kwang Hoon; Oh, Sang Ho; Suh, Hwal

    2002-06-01

    The newly developed laminin modified infection-preventing collagen membrane consists of a 3 component laminate, comprising 2 outer collagen layers and a central laminin layer. The 2 outer collagen layers (dense and porous layers) were fabricated by air-drying and freeze drying, respectively, and the laminin layer was formed by a straightforward liquid coating method. In addition, hyaluronan based microparticles containing silver sulfadiazine (AgSD) were incorporated into the 2 collagen layers (AgSD content 50 microg/cm2). Laminin coated collagen surfaces did not promote fibroblast attachment but showed a retarded fibroblast proliferation rate and an increased rate of collagen synthesis versus pure collagen surfaces. In an animal study, a laminin coating on a nonmedicated collagen membrane significantly increased both wound size reduction and vessel proliferation 7 days after application versus polyurethane film. Interestingly, the laminin coated AgSD medicated collagen membrane demonstrated higher wound size reduction and vessel proliferation and lower inflammation than the polyurethane control, suggesting that the laminin AgSD medicated collagen membrane substantially improves dermal wound healing.

  12. Periodontal regeneration with stem cells-seeded collagen-hydroxyapatite scaffold.

    PubMed

    Liu, Zeping; Yin, Xing; Ye, Qingsong; He, Wulin; Ge, Mengke; Zhou, Xiaofu; Hu, Jing; Zou, Shujuan

    2016-07-01

    Re-establishing compromised periodontium to its original structure, properties and function is demanding, but also challenging, for successful orthodontic treatment. In this study, the periodontal regeneration capability of collagen-hydroxyapatite scaffolds, seeded with bone marrow stem cells, was investigated in a canine labial alveolar bone defect model. Bone marrow stem cells were isolated, expanded and characterized. Porous collagen-hydroxyapatite scaffold and cross-linked collagen-hydroxyapatite scaffold were prepared. Attachment, migration, proliferation and morphology of bone marrow stem cells, co-cultured with porous collagen-hydroxyapatite or cross-linked collagen-hydroxyapatite, were evaluated in vitro. The periodontal regeneration capability of collagen-hydroxyapatite scaffold with or without bone marrow stem cells was tested in six beagle dogs, with each dog carrying one sham-operated site as healthy control, and three labial alveolar bone defects untreated to allow natural healing, treated with bone marrow stem cells - collagen-hydroxyapatite scaffold implant or collagen-hydroxyapatite scaffold implant, respectively. Animals were euthanized at 3 and 6 months (3 animals per group) after implantation and the resected maxillary and mandibular segments were examined using micro-computed tomography scan, H&E staining, Masson's staining and histometric evaluation. Bone marrow stem cells were successfully isolated and demonstrated self-renewal and multi-potency in vitro. The porous collagen-hydroxyapatite and cross-linked collagen-hydroxyapatite had average pore sizes of 415 ± 20 µm and 203 ± 18 µm and porosity of 69 ± 0.5% and 50 ± 0.2%, respectively. The attachment, proliferation and migration of bone marrow stem cells were satisfactory on both porous collagen-hydroxyapatite and cross-linked collagen-hydroxyapatite scaffolds. Implantation of bone marrow stem cells - collagen-hydroxyapatite or collagen-hydroxyapatite scaffold in

  13. Pulsed low-intensity ultrasound increases proliferation and extracelluar matrix production by human dermal fibroblasts in three-dimensional culture

    PubMed Central

    Bohari, Siti PM; Grover, Liam M; Hukins, David WL

    2015-01-01

    This study evaluated the effect of pulsed low-intensity ultrasound on cell proliferation, collagen production and glycosaminoglycan deposition by human dermal fibroblasts encapsulated in alginate. Hoechst 33258 assay for cell number, hydroxyproline assay for collagen content, dimethylmethylene blue assay for glycosaminoglycan content and scanning electron microscopy were performed on the encapsulated cells treated with pulsed low-intensity ultrasound and a control group that remained untreated. Pulsed low-intensity ultrasound showed a significant effect on cell proliferation and collagen deposition but no consistent pattern for glycosaminoglycan content. Alcian blue staining showed that glycosaminoglycans were deposited around the cells in both treated and control groups. These results suggest that pulsed low-intensity ultrasound alone shows a positive effect on cell proliferation and collagen deposition even without growth factor supplements. PMID:26668710

  14. Investigating the relationship between changes in collagen fiber orientation during skin aging and collagen/water interactions by polarized-FTIR microimaging.

    PubMed

    Eklouh-Molinier, Christophe; Happillon, Teddy; Bouland, Nicole; Fichel, Caroline; Diébold, Marie-Danièle; Angiboust, Jean-François; Manfait, Michel; Brassart-Pasco, Sylvie; Piot, Olivier

    2015-09-21

    Upon chronological aging, human skin undergoes structural and molecular modifications, especially at the level of type I collagen. This macromolecule is one of the main dermal structural proteins and presents several age-related alterations. It exhibits a triple helical structure and assembles itself to form fibrils and fibers. In addition, water plays an important role in stabilizing the collagen triple helix by forming hydrogen-bonds between collagen residues. However, the influence of water on changes of dermal collagen fiber orientation with age has not been yet understood. Polarized-Fourier Transform Infrared (P-FTIR) imaging is an interesting biophotonic approach to determine in situ the orientation of type I collagen fibers, as we have recently shown by comparing skin samples of different ages. In this work, P-FTIR spectral imaging was performed on skin samples from two age groups (35- and 38-year-old on the one hand, 60- and 66-year-old on the other hand), and our analyses were focused on the effect of H2O/D2O substitution. Spectral data were processed with fuzzy C-means (FCM) clustering in order to distinguish different orientations of collagen fibers. We demonstrated that the orientation was altered with aging, and that D2O treatment, affecting primarily highly bound water molecules, is more marked for the youngest skin samples. Collagen-bound water-related spectral markers were also highlighted. Our results suggest a weakening of water/collagen interactions with age. This non-destructive and label-free methodology allows us to understand better the importance of bound water in collagen fiber orientation alterations occurring with skin aging. Obtaining such structural information could find benefits in dermatology as well as in cosmetics.

  15. Distinct fibroblast lineages determine dermal architecture in skin development and repair

    PubMed Central

    Driskell, Ryan R.; Simons, Ben D.; Charalambous, Marika; Ferron, Sacri R.; Herault, Yann; Pavlovic, Guillaume; Ferguson-Smith, Anne C.; Watt, Fiona M.

    2013-01-01

    Fibroblasts are the major mesenchymal cell type in connective tissue and deposit the collagen and elastic fibers of the extracellular matrix (ECM)1. Even within a single tissue fibroblasts exhibit remarkable functional diversity, but it is not known whether this reflects the existence of a differentiation hierarchy or is a response to different environmental factors. Here we show, using transplantation assays and lineage tracing, that the fibroblasts of skin connective tissue arise from two distinct lineages. One forms the upper dermis, including the dermal papilla that regulates hair growth and the arrector pili muscle (APM), which controls piloerection. The other forms the lower dermis, including the reticular fibroblasts that synthesise the bulk of the fibrillar ECM, and the pre-adipocytes and adipocytes of the hypodermis. The upper lineage is required for hair follicle formation. In wounded adult skin, the initial wave of dermal repair is mediated by the lower lineage and upper dermal fibroblasts are recruited only during re-epithelialisation. Epidermal beta-catenin activation stimulates expansion of the upper dermal lineage, rendering wounds permissive for hair follicle formation. Our findings explain why wounding is linked to formation of ECM-rich scar tissue that lacks hair follicles2-4. They also form a platform for discovering fibroblast lineages in other tissues and for examining fibroblast changes in ageing and disease. PMID:24336287

  16. Enigmatic insight into collagen.

    PubMed

    Deshmukh, Shrutal Narendra; Dive, Alka M; Moharil, Rohit; Munde, Prashant

    2016-01-01

    Collagen is a unique, triple helical molecule which forms the major part of extracellular matrix. It is the most abundant protein in the human body, representing 30% of its dry weight. It is the fibrous structural protein that makes up the white fibers (collagen fibers) of skin, tendons, bones, cartilage and all other connective tissues. Collagens are not only essential for the mechanical resistance and resilience of multicellular organisms, but are also signaling molecules defining cellular shape and behavior. The human body has at least 16 types of collagen, but the most prominent types are I, II and III. Collagens are produced by several cell types and are distinguishable by their molecular compositions, morphologic characteristics, distribution, functions and pathogenesis. This is the major fibrous glycoprotein present in the extracellular matrix and in connective tissue and helps in maintaining the structural integrity of these tissues. It has a triple helical structure. Various studies have proved that mutations that modify folding of the triple helix result in identifiable genetic disorders. Collagen diseases share certain similarities with autoimmune diseases, because autoantibodies specific to each collagen disease are produced. Therefore, this review highlights the role of collagen in normal health and also the disorders associated with structural and functional defects in collagen. PMID:27601823

  17. Enigmatic insight into collagen

    PubMed Central

    Deshmukh, Shrutal Narendra; Dive, Alka M; Moharil, Rohit; Munde, Prashant

    2016-01-01

    Collagen is a unique, triple helical molecule which forms the major part of extracellular matrix. It is the most abundant protein in the human body, representing 30% of its dry weight. It is the fibrous structural protein that makes up the white fibers (collagen fibers) of skin, tendons, bones, cartilage and all other connective tissues. Collagens are not only essential for the mechanical resistance and resilience of multicellular organisms, but are also signaling molecules defining cellular shape and behavior. The human body has at least 16 types of collagen, but the most prominent types are I, II and III. Collagens are produced by several cell types and are distinguishable by their molecular compositions, morphologic characteristics, distribution, functions and pathogenesis. This is the major fibrous glycoprotein present in the extracellular matrix and in connective tissue and helps in maintaining the structural integrity of these tissues. It has a triple helical structure. Various studies have proved that mutations that modify folding of the triple helix result in identifiable genetic disorders. Collagen diseases share certain similarities with autoimmune diseases, because autoantibodies specific to each collagen disease are produced. Therefore, this review highlights the role of collagen in normal health and also the disorders associated with structural and functional defects in collagen.

  18. Enigmatic insight into collagen

    PubMed Central

    Deshmukh, Shrutal Narendra; Dive, Alka M; Moharil, Rohit; Munde, Prashant

    2016-01-01

    Collagen is a unique, triple helical molecule which forms the major part of extracellular matrix. It is the most abundant protein in the human body, representing 30% of its dry weight. It is the fibrous structural protein that makes up the white fibers (collagen fibers) of skin, tendons, bones, cartilage and all other connective tissues. Collagens are not only essential for the mechanical resistance and resilience of multicellular organisms, but are also signaling molecules defining cellular shape and behavior. The human body has at least 16 types of collagen, but the most prominent types are I, II and III. Collagens are produced by several cell types and are distinguishable by their molecular compositions, morphologic characteristics, distribution, functions and pathogenesis. This is the major fibrous glycoprotein present in the extracellular matrix and in connective tissue and helps in maintaining the structural integrity of these tissues. It has a triple helical structure. Various studies have proved that mutations that modify folding of the triple helix result in identifiable genetic disorders. Collagen diseases share certain similarities with autoimmune diseases, because autoantibodies specific to each collagen disease are produced. Therefore, this review highlights the role of collagen in normal health and also the disorders associated with structural and functional defects in collagen. PMID:27601823

  19. Reflectance Confocal Microscopy Features of Focal Dermal Mucinosis Differ from Those Described for Basal Cell Carcinoma: Report of Two Cases.

    PubMed

    Fraga-Braghiroli, Naiara Abreu; Merati, Miesha; Rabinovitz, Harold; Swanson, David; Scope, Alon

    2015-01-01

    The purpose of this study was to describe the reflectance confocal microscopy (RCM) features of focal dermal mucinosis (FDM). The entity clinically and dermatoscopically mimics other diagnostic entities, most notably nonpigmented basal cell carcinoma. We describe two cases that highlight the dermatoscopic, RCM and histopathological attributes of FDM. RCM features such as dermal foci of dense collagen bundles oriented in the same direction, foci of haphazardly oriented thin collagen fibers separated by dark structureless areas and the absence of dark silhouettes and tumor islands are clues for FDM diagnosis. The FDM cases described here present consistent and particular RCM findings that appear to correlate well with the histopathological features of FDM. Therefore, RCM is a promising technology in diagnosing skin lesions and it use can avoid invasive procedures. PMID:26302951

  20. Three Dimensional Collagen Scaffold Promotes Intrinsic Vascularisation for Tissue Engineering Applications

    PubMed Central

    Chan, Elsa C.; Kuo, Shyh-Ming; Kong, Anne M.; Morrison, Wayne A.; Dusting, Gregory J.; Mitchell, Geraldine M.

    2016-01-01

    Here, we describe a porous 3-dimensional collagen scaffold material that supports capillary formation in vitro, and promotes vascularization when implanted in vivo. Collagen scaffolds were synthesized from type I bovine collagen and have a uniform pore size of 80 μm. In vitro, scaffolds seeded with primary human microvascular endothelial cells suspended in human fibrin gel formed CD31 positive capillary-like structures with clear lumens. In vivo, after subcutaneous implantation in mice, cell-free collagen scaffolds were vascularized by host neovessels, whilst a gradual degradation of the scaffold material occurred over 8 weeks. Collagen scaffolds, impregnated with human fibrinogen gel, were implanted subcutaneously inside a chamber enclosing the femoral vessels in rats. Angiogenic sprouts from the femoral vessels invaded throughout the scaffolds and these degraded completely after 4 weeks. Vascular volume of the resulting constructs was greater than the vascular volume of constructs from chambers implanted with fibrinogen gel alone (42.7±5.0 μL in collagen scaffold vs 22.5±2.3 μL in fibrinogen gel alone; p<0.05, n = 7). In the same model, collagen scaffolds seeded with human adipose-derived stem cells (ASCs) produced greater increases in vascular volume than did cell-free collagen scaffolds (42.9±4.0 μL in collagen scaffold with human ASCs vs 25.7±1.9 μL in collagen scaffold alone; p<0.05, n = 4). In summary, these collagen scaffolds are biocompatible and could be used to grow more robust vascularized tissue engineering grafts with improved the survival of implanted cells. Such scaffolds could also be used as an assay model for studies on angiogenesis, 3-dimensional cell culture, and delivery of growth factors and cells in vivo. PMID:26900837

  1. Three Dimensional Collagen Scaffold Promotes Intrinsic Vascularisation for Tissue Engineering Applications.

    PubMed

    Chan, Elsa C; Kuo, Shyh-Ming; Kong, Anne M; Morrison, Wayne A; Dusting, Gregory J; Mitchell, Geraldine M; Lim, Shiang Y; Liu, Guei-Sheung

    2016-01-01

    Here, we describe a porous 3-dimensional collagen scaffold material that supports capillary formation in vitro, and promotes vascularization when implanted in vivo. Collagen scaffolds were synthesized from type I bovine collagen and have a uniform pore size of 80 μm. In vitro, scaffolds seeded with primary human microvascular endothelial cells suspended in human fibrin gel formed CD31 positive capillary-like structures with clear lumens. In vivo, after subcutaneous implantation in mice, cell-free collagen scaffolds were vascularized by host neovessels, whilst a gradual degradation of the scaffold material occurred over 8 weeks. Collagen scaffolds, impregnated with human fibrinogen gel, were implanted subcutaneously inside a chamber enclosing the femoral vessels in rats. Angiogenic sprouts from the femoral vessels invaded throughout the scaffolds and these degraded completely after 4 weeks. Vascular volume of the resulting constructs was greater than the vascular volume of constructs from chambers implanted with fibrinogen gel alone (42.7±5.0 μL in collagen scaffold vs 22.5±2.3 μL in fibrinogen gel alone; p<0.05, n = 7). In the same model, collagen scaffolds seeded with human adipose-derived stem cells (ASCs) produced greater increases in vascular volume than did cell-free collagen scaffolds (42.9±4.0 μL in collagen scaffold with human ASCs vs 25.7±1.9 μL in collagen scaffold alone; p<0.05, n = 4). In summary, these collagen scaffolds are biocompatible and could be used to grow more robust vascularized tissue engineering grafts with improved the survival of implanted cells. Such scaffolds could also be used as an assay model for studies on angiogenesis, 3-dimensional cell culture, and delivery of growth factors and cells in vivo.

  2. Camphor Induces Proliferative and Anti-senescence Activities in Human Primary Dermal Fibroblasts and Inhibits UV-Induced Wrinkle Formation in Mouse Skin.

    PubMed

    Tran, Thao Anh; Ho, Manh Tin; Song, Yeon Woo; Cho, Moonjae; Cho, Somi Kim

    2015-12-01

    Camphor ((1R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one), a bicyclic monoterpene, is one of the major constituents of essential oils from various herbs such as rosemary, lavender, and sage. In this study, we investigated the beneficial effects of camphor as a botanical ingredient in cosmetics. Camphor induced the proliferation of human primary dermal fibroblasts in a dose-dependent manner via the PI3K/AKT and ERK signaling pathways. Camphor attenuated the elevation of senescence associated with β-galactosidase (SA-β-gal) activity. Elastase activity decreased, while the total amount of collagen increased, in a dose- and time-dependent manner in human primary dermal fibroblasts treated with camphor. Camphor induced the expression of collagen IA, collagen IIIA, collagen IVA, and elastin in human primary dermal fibroblasts. In addition, posttreatment with 26 and 52 mM camphor for 2 weeks led to a significant reduction in the expression of MMP1 but increases in the expression of collagen IA, IIIA, and elastin in mouse skin exposed to UV for 4 weeks. These posttreatments also reduced the depths of the epidermis and subcutaneous fat layer in UV-exposed mouse skin. Taken together, these findings suggest camphor to be a potent wound healing and antiwrinkle agent with considerable potential for use in cosmeceuticals. PMID:26458283

  3. Species Typing in Dermal Leishmaniasis

    PubMed Central

    Dujardin, Jean-Claude

    2015-01-01

    SUMMARY Leishmania is an infectious protozoan parasite related to African and American trypanosomes. All Leishmania species that are pathogenic to humans can cause dermal disease. When one is confronted with cutaneous leishmaniasis, identification of the causative species is relevant in both clinical and epidemiological studies, case management, and control. This review gives an overview of the currently existing and most used assays for species discrimination, with a critical appraisal of the limitations of each technique. The consensus taxonomy for the genus is outlined, including debatable species designations. Finally, a numerical literature analysis is presented that describes which methods are most used in various countries and regions in the world, and for which purposes. PMID:25672782

  4. Collagenous gastritis: Review

    PubMed Central

    Kamimura, Kenya; Kobayashi, Masaaki; Sato, Yuichi; Aoyagi, Yutaka; Terai, Shuji

    2015-01-01

    Collagenous gastritis is a rare disease characterized by the subepithelial deposition of collagen bands thicker than 10 μm and the infiltration of inflammatory mononuclear cells in the lamina propria. Collagenous colitis and collagenous sprue have similar histological characteristics to collagenous gastritis and are thought to be part of the same disease entity. However, while collagenous colitis has become more common in the field of gastroenterology, presenting with clinical symptoms of chronic diarrhea in older patients, collagenous gastritis is rare. Since the disease was first reported in 1989, only 60 cases have been documented in the English literature. No safe and effective treatments have been identified from randomized, controlled trials. Therefore, better understanding of the disease and the reporting of more cases will help to establish diagnostic criteria and to develop therapeutic strategies. Therefore, here we review the clinical characteristics, endoscopic and histological findings, treatment, and clinical outcomes from case reports and case series published to date, and provide a summary of the latest information on the disease. This information will contribute to improved knowledge of collagenous gastritis so physicians can recognize and correctly diagnose the disease, and will help to develop a standard therapeutic strategy for future clinical trials. PMID:25789098

  5. Collagenous gastritis: Review.

    PubMed

    Kamimura, Kenya; Kobayashi, Masaaki; Sato, Yuichi; Aoyagi, Yutaka; Terai, Shuji

    2015-03-16

    Collagenous gastritis is a rare disease characterized by the subepithelial deposition of collagen bands thicker than 10 μm and the infiltration of inflammatory mononuclear cells in the lamina propria. Collagenous colitis and collagenous sprue have similar histological characteristics to collagenous gastritis and are thought to be part of the same disease entity. However, while collagenous colitis has become more common in the field of gastroenterology, presenting with clinical symptoms of chronic diarrhea in older patients, collagenous gastritis is rare. Since the disease was first reported in 1989, only 60 cases have been documented in the English literature. No safe and effective treatments have been identified from randomized, controlled trials. Therefore, better understanding of the disease and the reporting of more cases will help to establish diagnostic criteria and to develop therapeutic strategies. Therefore, here we review the clinical characteristics, endoscopic and histological findings, treatment, and clinical outcomes from case reports and case series published to date, and provide a summary of the latest information on the disease. This information will contribute to improved knowledge of collagenous gastritis so physicians can recognize and correctly diagnose the disease, and will help to develop a standard therapeutic strategy for future clinical trials. PMID:25789098

  6. Collagen XII and XIV, New Partners of Cartilage Oligomeric Matrix Protein in the Skin Extracellular Matrix Suprastructure*

    PubMed Central

    Agarwal, Pallavi; Zwolanek, Daniela; Keene, Douglas R.; Schulz, Jan-Niklas; Blumbach, Katrin; Heinegård, Dick; Zaucke, Frank; Paulsson, Mats; Krieg, Thomas; Koch, Manuel; Eckes, Beate

    2012-01-01

    The tensile and scaffolding properties of skin rely on the complex extracellular matrix (ECM) that surrounds cells, vasculature, nerves, and adnexus structures and supports the epidermis. In the skin, collagen I fibrils are the major structural component of the dermal ECM, decorated by proteoglycans and by fibril-associated collagens with interrupted triple helices such as collagens XII and XIV. Here we show that the cartilage oligomeric matrix protein (COMP), an abundant component of cartilage ECM, is expressed in healthy human skin. COMP expression is detected in the dermal compartment of skin and in cultured fibroblasts, whereas epidermis and HaCaT cells are negative. In addition to binding collagen I, COMP binds to collagens XII and XIV via their C-terminal collagenous domains. All three proteins codistribute in a characteristic narrow zone in the superficial papillary dermis of healthy human skin. Ultrastructural analysis by immunogold labeling confirmed colocalization and further revealed the presence of COMP along with collagens XII and XIV in anchoring plaques. On the basis of these observations, we postulate that COMP functions as an adapter protein in human skin, similar to its function in cartilage ECM, by organizing collagen I fibrils into a suprastructure, mainly in the vicinity of anchoring plaques that stabilize the cohesion between the upper dermis and the basement membrane zone. PMID:22573329

  7. Mutual induction of growth factor gene expression by epidermal-dermal cell interaction

    PubMed Central

    1993-01-01

    Epithelial-mesenchymal interactions control epidermal growth and differentiation, but little is known about the mechanisms of this interaction. We have examined the effects of human dermal microvascular endothelial cells (DMEC) and fibroblasts on keratinocytes in conventional (feeder layer) and organotypic cocultures (lifted collagen gels) and demonstrated the induction of paracrine growth factor gene expression. Clonal keratinocyte growth was similarly stimulated in cocultures with irradiated DMEC and fibroblasts as feeder cells. This effect is most probably caused by induction of growth factor expression in cocultured dermal cells. Keratinocytes stimulated mRNA levels for KGF and IL-6 in both mesenchymal cell types and GM-CSF in fibroblasts. The feeder effect could not be replaced by conditioned media or addition of isolated growth factors. In organotypic cocultures with keratinocytes growing on collagen gels (repopulated with dermal cells), a virtually normal epidermis was formed within 7 to 10 d. Keratinocyte proliferation was drastically stimulated by dermal cells (histone 3 mRNA expression and BrdU labeling) which continued to proliferate as well in the gel. Expression of all typical differentiation markers was provoked in the reconstituted epithelium, though with different localization as compared to normal epidermis. Keratins K1 and K10 appeared coexpressed but delayed, reflecting conditions in epidermal hyperplasia. Keratin localization and proliferation were normalized under in vivo conditions, i.e., in surface transplants on nude mice. From these data it is concluded that epidermal homeostasis is in part controlled by complex reciprocally induced paracrine acting factors in concert with cell-cell interactions and extracellular matrix influences. PMID:8320264

  8. Differentiation within autologous fibrin scaffolds of porcine dermal cells with the mesenchymal stem cell phenotype

    SciTech Connect

    Puente, Pilar de la

    2013-02-01

    Porcine mesenchymal stem cells (pMSCs) are an attractive source of cells for tissue engineering because their properties are similar to those of human stem cells. pMSCs can be found in different tissues but their dermal origin has not been studied in depth. Additionally, MSCs differentiation in monolayer cultures requires subcultured cells, and these cells are at risk of dedifferentiation when implanting them into living tissue. Following this, we attempted to characterize the MSCs phenotype of porcine dermal cells and to evaluate their cellular proliferation and differentiation in autologous fibrin scaffolds (AFSs). Dermal biopsies and blood samples were obtained from 12 pigs. Dermal cells were characterized by flow cytometry. Frozen autologous plasma was used to prepare AFSs. pMSC differentiation was studied in standard structures (monolayers and pellets) and in AFSs. The pMSCs expressed the CD90 and CD29 markers of the mesenchymal lineage. AFSs afforded adipogenic, osteogenic and chondrogenic differentiation. The porcine dermis can be proposed to be a good source of MSCs with adequate proliferative capacity and a suitable expression of markers. The pMSCs also showed optimal proliferation and differentiation in AFSs, such that these might serve as a promising autologous and implantable material for use in tissue engineering. -- Highlights: ► Low fibrinogen concentration provides a suitable matrix for cell migration and differentiation. ► Autologous fibrin scaffolds is a promising technique in tissue engineering. ► Dermal cells are an easily accessible mesenchymal stem cell source. ► Fibrin scaffolds afforded adipogenic, osteogenic and chondrogenic differentiation.

  9. Cochlear Implants.

    ERIC Educational Resources Information Center

    Clark, Catherine; Scott, Larry

    This brochure explains what a cochlear implant is, lists the types of individuals with deafness who may be helped by a cochlear implant, describes the process of evaluating people for cochlear implants, discusses the surgical process for implanting the aid, traces the path of sound through the cochlear implant to the brain, notes the costs of…

  10. Collagen: Biochemistry, biomechanics, biotechnology

    SciTech Connect

    Nimni, M.E.

    1988-01-01

    This book is an up-to-date reference for new ideas, information, and concepts in collagen research. The first volume emphasizes the relationship between the molecular structure and function of collagen, including descriptions of collagen types which exist in tissues as well as how these molecules organize into fibrils and the nature of the chemical crosslinks which stabilize them. In Volume II the biomechanical behavior of various specialized tissues, abnormal accumulation of collagen in the form of scars of fibrous infiltration are examined/and wound healing, tissue regulation and repair are covered in detail. Volume III explores the increasing application of collagen technology to the field of bioprosthesis, including the production of heart valve bioprosthesis, blood vessels, ligament substitutes, and bone substitutes.

  11. Backbone dynamics in collagen

    NASA Astrophysics Data System (ADS)

    Aliev, Abil E.

    2004-11-01

    Peptide backbone motions of collagen have been extensively studied in the past. The experimental results were interpreted using a model of a collagen rod librating about its helix axis. Considering the size of the collagen molecule and the presence of cross-linked molecules, motional amplitudes derived for the helix axis libration were unusually high. Using solid-state NMR 13C chemical shift anisotropy and 2H quadrupolar lineshape analysis for five different isotope labelled collagens we show that motional averaging of the NMR interactions occurs primarily via small-angle librations about internal bond directions. This type of dynamics is compatible with both the presence of cross-links in collagen and the X-ray data, as well as dynamic models used for other proteins.

  12. Assessment of dermal exposure and histopathologic changes of different sized nano-silver in healthy adult rabbits

    NASA Astrophysics Data System (ADS)

    kazem Koohi, Mohammad; Hejazy, Marzie; Asadi, Farzad; Asadian, Peyman

    2011-07-01

    The purpose of this study is to evaluate the dermal toxicity (Irritation/Corrosion) of three sizes of nanosilver particles (10, 20 and 30 nm) during 3 min, 1 and 4 hours according to the OECD/OCDE guideline Histopathological effects in secondary organs from liver, kidney, heart, spleen and brain 14 day post dermal administration are also reported. 10 and 20 nm Ag nanoparticles treated group showed well defined dermal erythema and oedema. Histopathological findings of 10 and 20 nm (4 hours exposure) on 14-day post dermal administration showed hyperkeratosis, acanthosis, hair-filled follicles and papillomatosis in an irregular epidermis, fibrosis, hyperemia, erythema, intracellular oedema and hyalinisation of collagen in dermis of skin. Liver revealed midzonal and periacinar necrosis, portal mononuclear infiltration, liver fatty change, liver congestion and hyperemic central vein. Splenic red pulp congestion and white pulp hyperreactivity, splenic trabeculae and sinusoidal congestion and hyaline change were found in spleen. Fatty degeneration in some cardiovascular cells and subendocardial hemorrhage without inflammation was perceived. Picnotic appearance of pyramidal neurons in the brain cortex, gliosis and mild perineuronal oedema ischemic cell change and hyperemic meninges was observed in brain. Our research concluded that dermal exposure to lesser sizes of silver nanoparticles is more disastrous than greater ones.

  13. The Use of Fetal Bovine Dermal Scaffold (PriMatrix) in the Management of Full-Thickness Hand Burns

    PubMed Central

    Karcich, Jenika; Granick, Mark S.; Marano, Michael A.

    2014-01-01

    Objective: Management of full-thickness burn wounds represents a challenge when reconstructive options are not applicable. Fetal bovine dermal matrix is a bioactive collagen scaffold that assimilates into wounds and stimulates vascularization and dermal regeneration. Methods: We present the use of fetal bovine dermal scaffold PriMatrix in the treatment of a patient who sustained scald-immersion full-thickness burns of her bilateral hands that failed conventional wound therapy. Results: A 71-year-old woman with advanced Parkinson's disease sustained self-induced 5% mixed second- and third-degree scald-immersion burns of her bilateral hands and fingers. The patient underwent extensive debridement that resulted in partially avascular wounds measuring 66 cm2 and 72 cm2 with exposed extensor tendons and no evidence of bleeding. Meshed homograft was applied, but her hands remained partly avascular. PriMatrix fetal bovine dermal scaffold was applied to provide tissue remodeling over the bones, which allowed successful skin grafting and complete wound healing. Conclusions: Our experience shows fetal bovine dermal scaffold to be an effective method in management of complicated burn wounds in selected cases. Further studies need to be implemented to confer this conclusion. PMID:25328569

  14. A Prospective Study Assessing Complication Rates and Patient-Reported Outcomes in Breast Reconstructions Using a Novel, Deep Dermal Human Acellular Dermal Matrix

    PubMed Central

    Vu, Michael M.; De Oliveira, Gildasio S.; Mayer, Kristen E.; Blough, Jordan T.

    2015-01-01

    Abstract Background: The value proposition of an acellular dermal matrix (ADM) taken from the deep dermis is that the allograft may be more porous, allowing for enhanced integration and revascularization. In turn, this characteristic may attenuate complications related to foreign body reactions, seromas, and infection. However, this is juxtaposed against the potential loss of allograft structural integrity, with subsequent risk of malposition and extrusion. Despite the active use of novel, deep dermal ADMs, the clinical outcomes of this new technology has not been well studied. Methods: This is a prospective study to evaluate surgical and patient-reported outcomes using a deep dermal ADM, FlexHD Pliable. Surgical outcomes and BREAST-Q patient-reported outcomes were evaluated postoperatively at 2- and 6-month time points. Results: Seventy-two breasts (41 patients) underwent reconstruction. Complication rate was 12.5%, including 2 hematomas and 7 flap necroses. One case of flap necrosis led to reconstructive failure. Notably, there were no cases of infection, seroma, or implant extrusion or malposition. Average BREAST-Q scores were satisfaction with outcome (70.13 ± 23.87), satisfaction with breasts (58.53 ± 20.00), psychosocial well being (67.97 ± 20.93), sexual well being (54.11 ± 27.72), and physical well being (70.45 ± 15.44). Two-month postoperative BREAST-Q scores decreased compared with baseline and returned to baseline by 6 months. Postoperative radiation therapy had a negative effect on satisfaction with breasts (P = 0.004) and sexual well being (P = 0.006). Conclusions: Deep dermal ADM is a novel modification of traditional allograft technology. Use of the deep dermal ADM yielded acceptably low complication rates and satisfactory patient-reported outcomes. PMID:26894010

  15. Dermal fillers for facial soft tissue augmentation.

    PubMed

    Dastoor, Sarosh F; Misch, Carl E; Wang, Hom-Lay

    2007-01-01

    Nowadays, patients are demanding not only enhancement to their dental (micro) esthetics, but also their overall facial (macro) esthetics. Soft tissue augmentation via dermal filling agents may be used to correct facial defects such as wrinkles caused by age, gravity, and trauma; thin lips; asymmetrical facial appearances; buccal fold depressions; and others. This article will review the pathogenesis of facial wrinkles, history, techniques, materials, complications, and clinical controversies regarding dermal fillers for soft tissue augmentation.

  16. Differences between scar and dermal cultured fibroblasts derived from a patient with recurrent abdominal incision wound herniation.

    PubMed

    Boemi, L; Allison, G M; Graham, W P; Krummel, T M; Ehrlich, H P

    1999-10-01

    Fibroblasts were derived from dermis and scar of a 47-year-old white man with a recurrent incisional hernia as a result of fractured ribs. The scar was thin and stretched, suggesting a defect in the maturation of granulation tissue. After surgical repair, biopsy specimens of discarded scar and skin were used to generate fibroblast cell lines. Fibroblasts maintained in medium containing 10% fetal bovine serum and antibiotic were studied between their third and eighth passage. By phase contrast microscopy, no structural differences were obvious, but it was noted that to pass scar fibroblasts, a more aggressive trypsin regimen was required. Immunohistologic and Western blot analysis of patient scar fibroblasts showed (1) more a smooth muscle actin within stress fibers, (2) increased expression of the vitronectin integrin receptor alpha(v) (CD 51), and (3) reduced expression of the collagen integrin receptor alpha2 (CD 49b). The expression of vinculin from focal adhesions or a tubulin from microtubules was the same among cell lines. Contractions of scar and dermal fibroblast-populated collagen lattice were compared. At 24 hours, contractions were 69 percent with newborn fibroblasts (normal); 68 percent for patient dermal fibroblasts; and only 48 percent for patient scar fibroblasts. The retarded contraction of scar fibroblast-populated collagen lattice was significant (p > or = 0.002). Myosin ATPase activity, critical for lattice contraction, and cell migration were equivalent among all cell lines. A plausible mechanism for the retardation of scar lattice contraction is disruption of fibroblasts and collagen interactions, for which the attachment of cells to collagen is altered. It is proposed that either the decrease in the expression of collagen integrin receptor alpha2 (CD 49b), an increase in the expression of the vitronectin receptor alpha(v) (CD 51), or a combination of both is responsible for disruption of collagen fibroblast interactions.

  17. Collagen Matrix Remodeling in Stented Pulmonary Arteries after Transapical Heart Valve Replacement.

    PubMed

    Ghazanfari, Samaneh; Driessen-Mol, Anita; Hoerstrup, Simon P; Baaijens, Frank P T; Bouten, Carlijn V C

    2016-01-01

    The use of valved stents for minimally invasive replacement of semilunar heart valves is expected to change the extracellular matrix and mechanical function of the native artery and may thus impair long-term functionality of the implant. Here we investigate the impact of the stent on matrix remodeling of the pulmonary artery in a sheep model, focusing on matrix composition and collagen (re)orientation of the host tissue. Ovine native pulmonary arteries were harvested 8 (n = 2), 16 (n = 4) and 24 (n = 2) weeks after transapical implantation of self-expandable stented heart valves. Second harmonic generation (SHG) microscopy was used to assess the collagen (re)orientation of fresh tissue samples. The collagen and elastin content was quantified using biochemical assays. SHG microscopy revealed regional differences in collagen organization in all explants. In the adventitial layer of the arterial wall far distal to the stent (considered as the control tissue), we observed wavy collagen fibers oriented in the circumferential direction. These circumferential fibers were more straightened in the adventitial layer located behind the stent. On the luminal side of the wall behind the stent, collagen fibers were aligned along the stent struts and randomly oriented between the struts. Immediately distal to the stent, however, fibers on both the luminal and the adventitial side of the wall were oriented in the axial direction, demonstrating the stent impact on the collagen structure of surrounding arterial tissues. Collagen orientation patterns did not change with implantation time, and biochemical analyses showed no changes in the trend of collagen and elastin content with implantation time or location of the vascular wall. We hypothesize that the collagen fibers on the adventitial side of the arterial wall and behind the stent straighten in response to the arterial stretch caused by oversizing of the stent. However, the collagen organization on the luminal side suggests that

  18. The fibrillar collagen family.

    PubMed

    Exposito, Jean-Yves; Valcourt, Ulrich; Cluzel, Caroline; Lethias, Claire

    2010-01-01

    Collagens, or more precisely collagen-based extracellular matrices, are often considered as a metazoan hallmark. Among the collagens, fibrillar collagens are present from sponges to humans, and are involved in the formation of the well-known striated fibrils. In this review we discuss the different steps in the evolution of this protein family, from the formation of an ancestral fibrillar collagen gene to the formation of different clades. Genomic data from the choanoflagellate (sister group of Metazoa) Monosiga brevicollis, and from diploblast animals, have suggested that the formation of an ancestral alpha chain occurred before the metazoan radiation. Phylogenetic studies have suggested an early emergence of the three clades that were first described in mammals. Hence the duplication events leading to the formation of the A, B and C clades occurred before the eumetazoan radiation. Another important event has been the two rounds of "whole genome duplication" leading to the amplification of fibrillar collagen gene numbers, and the importance of this diversification in developmental processes. We will also discuss some other aspects of fibrillar collagen evolution such as the development of the molecular mechanisms involved in the formation of procollagen molecules and of striated fibrils. PMID:20386646

  19. Improved method for in vitro assessment of dermal toxicity for volatile organic chemicals.

    PubMed

    Rogers, James V; McDougal, James N

    2002-09-01

    Cell culture methods are being developed to assess the dermal toxicity (irritancy and corrosion) of chemicals. These in vitro methods are being validated to categorize chemicals as irritating or non-irritating to humans. Currently, these cell culture tests are useful to assist in the ranking of chemicals for irritancy, but they are not useful for quantitative risk assessment for two reasons. First, for volatile chemicals the amount of chemical in the media that the cells are exposed to may decrease with exposure time. Also, effective concentrations such as EC(50) and IC(50) are reported as the concentrations in the media not the skin tissue/cells. We have developed an in vitro approach for dermal toxicity testing of volatile chemicals that avoids these problems. Using sealed vials lacking a headspace, dermal equivalents (dermal fibroblasts in a collagen matrix) were exposed to culture medium containing a test chemical (m-xylene) and compared to a traditional open well culture system. We found that about 90% of the m-xylene was lost from the open well plates and the viability was 4-6 times greater than in the closed system. Partition coefficients were measured and used to estimate the m-xylene concentration in the fibroblasts. The EC(50) for m-xylene in the dermal equivalents was 833.13+/-35.33 microg m-xylene per gram of fibroblasts. This method will provide an effective approach to relate target cell chemical concentration to cellular responses. Based on this method, a biologically-based mathematical model could be used to determine an equivalent external dose for a specific toxic end point.

  20. Dental Implants

    MedlinePlus

    ... Procedures Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain Fixed Bridges Porcelain Veneers Repairing Chipped Teeth Teeth Whitening Tooth- ...

  1. Synergistic effect of vitamin D and low concentration of transforming growth factor beta 1, a potential role in dermal wound healing.

    PubMed

    Ding, Jie; Kwan, Peter; Ma, Zengshuan; Iwashina, Takashi; Wang, Jianfei; Shankowsky, Heather A; Tredget, Edward E

    2016-09-01

    Dermal wound healing, in which transforming growth factor beta 1 (TGFβ1) plays an important role, is a complex process. Previous studies suggest that vitamin D has a potential regulatory role in TGFβ1 induced activation in bone formation, and there is cross-talk between their signaling pathways, but research on their effects in other types of wound healing is limited. The authors therefore wanted to explore the role of vitamin D and its interaction with low concentration of TGFβ1 in dermal fibroblast-mediated wound healing through an in vitro study. Human dermal fibroblasts were treated with vitamin D, TGFβ1, both, or vehicle, and then the wound healing functions of dermal fibroblasts were measured. To further explore possible mechanisms explaining the synergistic effect of vitamin D and TGFβ1, targeted gene silencing of the vitamin D receptor was performed. Compared to either factor alone, treatment of fibroblasts with both vitamin D and low concentration of TGFβ1 increased gene expression of TGFβ1, connective tissue growth factor, and fibronectin 1, and enhanced fibroblast migration, myofibroblast formation, and collagen production. Vitamin D receptor gene silencing blocked this synergistic effect of vitamin D and TGFβ1 on both collagen production and myofibroblast differentiation. Thus a synergistic effect of vitamin D and low TGFβ1 concentration was found in dermal fibroblast-mediated wound healing in vitro. This study suggests that supplementation of vitamin D may be an important step to improve wound healing and regeneration in patients with a vitamin D deficiency. PMID:27222384

  2. Synergistic effect of vitamin D and low concentration of transforming growth factor beta 1, a potential role in dermal wound healing.

    PubMed

    Ding, Jie; Kwan, Peter; Ma, Zengshuan; Iwashina, Takashi; Wang, Jianfei; Shankowsky, Heather A; Tredget, Edward E

    2016-09-01

    Dermal wound healing, in which transforming growth factor beta 1 (TGFβ1) plays an important role, is a complex process. Previous studies suggest that vitamin D has a potential regulatory role in TGFβ1 induced activation in bone formation, and there is cross-talk between their signaling pathways, but research on their effects in other types of wound healing is limited. The authors therefore wanted to explore the role of vitamin D and its interaction with low concentration of TGFβ1 in dermal fibroblast-mediated wound healing through an in vitro study. Human dermal fibroblasts were treated with vitamin D, TGFβ1, both, or vehicle, and then the wound healing functions of dermal fibroblasts were measured. To further explore possible mechanisms explaining the synergistic effect of vitamin D and TGFβ1, targeted gene silencing of the vitamin D receptor was performed. Compared to either factor alone, treatment of fibroblasts with both vitamin D and low concentration of TGFβ1 increased gene expression of TGFβ1, connective tissue growth factor, and fibronectin 1, and enhanced fibroblast migration, myofibroblast formation, and collagen production. Vitamin D receptor gene silencing blocked this synergistic effect of vitamin D and TGFβ1 on both collagen production and myofibroblast differentiation. Thus a synergistic effect of vitamin D and low TGFβ1 concentration was found in dermal fibroblast-mediated wound healing in vitro. This study suggests that supplementation of vitamin D may be an important step to improve wound healing and regeneration in patients with a vitamin D deficiency.

  3. The influence of discoidin domain receptor 2 on the persistence length of collagen type I fibers.

    PubMed

    Sivakumar, Lalitha; Agarwal, Gunjan

    2010-06-01

    Collagen fibers in the vertebrate tissue are responsible for its tensile strength. A disruption in the morphological or mechanical properties of collagen fibers is bound to impact tensile strength and contractility of tissues and affect several cellular processes. We had recently established that binding of discoidin domain receptor (DDR2) with collagen type I results in disruption of the native structure and morphology of collagen fibers. In this study we investigate if DDR2 affects the mechanical properties of collagen fibers. We used an analytical approach to determine the persistence length (P(L)) of collagen fibers from transmission electron microscope images of immobilized collagen. Fluctuations in the curvature of collagen fibers formed in-vitro (with or without recombinant DDR2) were analyzed to ascertain their P(L). The P(L) values and fiber-diameter measurements were utilized to estimate Young's Modulus (E) of collagen fibers. Our results show that DDR2 significantly reduced P(L) and E of collagen fibers. We further found that P(L) for native collagen fibers increases as a function of collagen concentration with little dependence on fiber diameter. These results signify a physiological role of DDR2 in modulating extracellular matrix stiffness, which may be of relevance for tissue engineering and medical implants especially in diseases where DDR2 is upregulated.

  4. Comparison of Calcium and Barium Microcapsules as Scaffolds in the Development of Artificial Dermal Papillae.

    PubMed

    Liu, Yang; Lin, Changmin; Zeng, Yang; Li, Haihong; Cai, Bozhi; Huang, Keng; Yuan, Yanping; Li, Yu

    2016-01-01

    This study aimed to develop and evaluate barium and calcium microcapsules as candidates for scaffolding in artificial dermal papilla. Dermal papilla cells (DPCs) were isolated and cultured by one-step collagenase treatment. The DPC-Ba and DPC-Ca microcapsules were prepared by using a specially designed, high-voltage, electric-field droplet generator. Selected microcapsules were assessed for long-term inductive properties with xenotransplantation into Sprague-Dawley rat ears. Both barium and calcium microcapsules maintained xenogenic dermal papilla cells in an immunoisolated environment and induced the formation of hair follicle structures. Calcium microcapsules showed better biocompatibility, permeability, and cell viability in comparison with barium microcapsules. Before 18 weeks, calcium microcapsules gathered together, with no substantial immune response. After 32 weeks, some microcapsules were near inflammatory cells and wrapped with fiber. A few large hair follicles were found. Control samples showed no marked changes at the implantation site. Barium microcapsules were superior to calcium microcapsules in structural and mechanical stability. The cells encapsulated in hydrogel barium microcapsules exhibited higher short-term viability. This study established a model to culture DPCs in 3D culture conditions. Barium microcapsules may be useful in short-term transplantation study. Calcium microcapsules may provide an effective scaffold for the development of artificial dermal papilla.

  5. Comparison of Calcium and Barium Microcapsules as Scaffolds in the Development of Artificial Dermal Papillae

    PubMed Central

    Liu, Yang; Lin, Changmin; Zeng, Yang; Li, Haihong; Cai, Bozhi; Huang, Keng; Yuan, Yanping; Li, Yu

    2016-01-01

    This study aimed to develop and evaluate barium and calcium microcapsules as candidates for scaffolding in artificial dermal papilla. Dermal papilla cells (DPCs) were isolated and cultured by one-step collagenase treatment. The DPC-Ba and DPC-Ca microcapsules were prepared by using a specially designed, high-voltage, electric-field droplet generator. Selected microcapsules were assessed for long-term inductive properties with xenotransplantation into Sprague-Dawley rat ears. Both barium and calcium microcapsules maintained xenogenic dermal papilla cells in an immunoisolated environment and induced the formation of hair follicle structures. Calcium microcapsules showed better biocompatibility, permeability, and cell viability in comparison with barium microcapsules. Before 18 weeks, calcium microcapsules gathered together, with no substantial immune response. After 32 weeks, some microcapsules were near inflammatory cells and wrapped with fiber. A few large hair follicles were found. Control samples showed no marked changes at the implantation site. Barium microcapsules were superior to calcium microcapsules in structural and mechanical stability. The cells encapsulated in hydrogel barium microcapsules exhibited higher short-term viability. This study established a model to culture DPCs in 3D culture conditions. Barium microcapsules may be useful in short-term transplantation study. Calcium microcapsules may provide an effective scaffold for the development of artificial dermal papilla. PMID:27123456

  6. Comparison of Calcium and Barium Microcapsules as Scaffolds in the Development of Artificial Dermal Papillae.

    PubMed

    Liu, Yang; Lin, Changmin; Zeng, Yang; Li, Haihong; Cai, Bozhi; Huang, Keng; Yuan, Yanping; Li, Yu

    2016-01-01

    This study aimed to develop and evaluate barium and calcium microcapsules as candidates for scaffolding in artificial dermal papilla. Dermal papilla cells (DPCs) were isolated and cultured by one-step collagenase treatment. The DPC-Ba and DPC-Ca microcapsules were prepared by using a specially designed, high-voltage, electric-field droplet generator. Selected microcapsules were assessed for long-term inductive properties with xenotransplantation into Sprague-Dawley rat ears. Both barium and calcium microcapsules maintained xenogenic dermal papilla cells in an immunoisolated environment and induced the formation of hair follicle structures. Calcium microcapsules showed better biocompatibility, permeability, and cell viability in comparison with barium microcapsules. Before 18 weeks, calcium microcapsules gathered together, with no substantial immune response. After 32 weeks, some microcapsules were near inflammatory cells and wrapped with fiber. A few large hair follicles were found. Control samples showed no marked changes at the implantation site. Barium microcapsules were superior to calcium microcapsules in structural and mechanical stability. The cells encapsulated in hydrogel barium microcapsules exhibited higher short-term viability. This study established a model to culture DPCs in 3D culture conditions. Barium microcapsules may be useful in short-term transplantation study. Calcium microcapsules may provide an effective scaffold for the development of artificial dermal papilla. PMID:27123456

  7. Aseptic versus Sterile Acellular Dermal Matrices in Breast Reconstruction: An Updated Review

    PubMed Central

    Mendenhall, Shaun D.; Neumeister, Michael W.; Cederna, Paul S.; Momoh, Adeyiza O.

    2016-01-01

    Background: As the use of acellular dermal matrices in breast reconstruction has become more commonplace and efforts are made to improve on postoperative outcomes, the method of acellular dermal matrix (ADM) processing (aseptic versus sterile) has become a subject of interest. This article provides an updated overview of the critical aspects of ADM processing in addition to application of ADMs in single- and two-stage breast reconstruction, a review of the morbidity associated with ADM use, and alternatives. Methods: A literature review was performed in PubMed identifying recent systematic reviews, meta-analyses, and head-to-head comparisons on aseptically processed ADM and sterile-processed ADM in implant-based breast reconstruction. Results: Recent meta-analyses have shown a 2- to 3-fold increase in infections and tissue expander/implant explantation rates and a 3- to 4-fold increase in seroma formation compared with non-ADM reconstruction techniques. Comparisons of aseptic and sterile ADMs in multiple studies have shown no significant difference in infection rates and equivocal findings for other specific complications such as seroma formation. Conclusions: Current evidence on the impact of processing techniques that improve ADM sterility on postoperative morbidity in implant breast reconstruction is unclear. Deficiencies of the available data highlight the need for well-designed, multicenter, randomized controlled studies that will aid in optimizing outcomes in implant-based breast reconstruction. PMID:27536502

  8. Bone formation ability of carbonate apatite-collagen scaffolds with different carbonate contents.

    PubMed

    Matsuura, Ayumu; Kubo, Takayasu; Doi, Kazuya; Hayashi, Kazuhiko; Morita, Kouji; Yokota, Rie; Hayashi, Hidetaka; Hirata, Isao; Okazaki, Masayuki; Akagawa, Yasumasa

    2009-03-01

    Hydroxyapatite and carbonate apatites with different carbonate contents were synthesized, mixed with atelocollagen, and made into sponge scaffolds. The scaffolds were implanted into the bone sockets of the femurs of male New Zealand white rabbits for 2, 3, 12 and 24 weeks. carbonate apatite-collagen scaffold with 4.8 wt% carbonate content appeared to have similar crystallinity and chemical composition to human bone. When the scaffolds were implanted into the rabbit femurs, histological observation indicated that the carbonate apatites-collagen scaffolds with relatively higher carbonate contents were gradually deformed throughout the implantation period, and showed uniform surrounding bone after 24 weeks and could not be distinguished. The carbonate apatite-collagen scaffold with 4.8 wt% carbonate content showed the highest bone area ratio of all of the scaffolds. It is suggested that a carbonate apatite-collagen scaffold with carbonate content similar to that of human bone may have optimal bone formation ability.

  9. Manipulating Cx43 expression triggers gene reprogramming events in dermal fibroblasts from oculodentodigital dysplasia patients.

    PubMed

    Esseltine, Jessica L; Shao, Qing; Huang, Tao; Kelly, John J; Sampson, Jacinda; Laird, Dale W

    2015-11-15

    Oculodentodigital dysplasia (ODDD) is primarily an autosomal dominant disorder linked to over 70 GJA1 gene [connexin43 (Cx43)] mutations. For nearly a decade, our laboratory has been investigating the relationship between Cx43 and ODDD by expressing disease-linked mutants in reference cells, tissue-relevant cell lines, 3D organ cultures and by using genetically modified mouse models of human disease. Although salient features of Cx43 mutants have been revealed, these models do not necessarily reflect the complexity of the human context. To further overcome these limitations, we have acquired dermal fibroblasts from two ODDD-affected individuals harbouring D3N and V216L mutations in Cx43, along with familial controls. Using these ODDD patient dermal fibroblasts, which naturally produce less GJA1 gene product, along with RNAi and RNA activation (RNAa) approaches, we show that manipulating Cx43 expression triggers cellular gene reprogramming. Quantitative RT-PCR, Western blot and immunofluorescent analysis of ODDD patient fibroblasts show unusually high levels of extracellular matrix (ECM)-interacting proteins, including integrin α5β1, matrix metalloproteinases as well as secreted ECM proteins collagen-I and laminin. Cx43 knockdown in familial control cells produces similar effects on ECM expression, whereas Cx43 transcriptional up-regulation using RNAa decreases production of collagen-I. Interestingly, the enhanced levels of ECM-associated proteins in ODDD V216L fibroblasts is not only a consequence of increased ECM gene expression, but also due to an apparent deficit in collagen-I secretion which may further contribute to impaired collagen gel contraction in ODDD fibroblasts. These findings further illuminate the altered function of Cx43 in ODDD-affected individuals and highlight the impact of manipulating Cx43 expression in human cells. PMID:26349540

  10. Collagen assembly from acid solution to networks on solid surfaces and to fibrils

    NASA Astrophysics Data System (ADS)

    Bradt, Jens-Hilmar; Mertig, Michael; Winzer, Bettina; Thiele, Uwe; Pompe, Wolfgang

    1996-04-01

    Two different kinds of collagen assembly have been studied: the reconstitution of type I collagen to fibrils and the formation of 2D networks on surfaces. The kinetics of fibril assembly are influenced by polyaspartate, as measured turbidimetrically. Addition of polyaspartate increases the fibril diameter. The reconstituted fibrils are imaged by atomic force microscopy and scanning electron microscopy. The preparation of thin collagen films on highly oriented pyrolytic graphite leads to networks or tree like structures depending on the collagen concentration in the precursor. The results presented are of interest for the development of new bone-like implant materials and the covering of bone grafts with a biocompatible layer.

  11. Correlative nonlinear optical microscopy and infrared nanoscopy reveals collagen degradation in altered parchments.

    PubMed

    Latour, Gaël; Robinet, Laurianne; Dazzi, Alexandre; Portier, François; Deniset-Besseau, Ariane; Schanne-Klein, Marie-Claire

    2016-05-19

    This paper presents the correlative imaging of collagen denaturation by nonlinear optical microscopy (NLO) and nanoscale infrared (IR) spectroscopy to obtain morphological and chemical information at different length scales. Such multiscale correlated measurements are applied to the investigation of ancient parchments, which are mainly composed of dermal fibrillar collagen. The main issue is to characterize gelatinization, the ultimate and irreversible alteration corresponding to collagen denaturation to gelatin, which may also occur in biological tissues. Key information about collagen and gelatin signatures is obtained in parchments and assessed by characterizing the denaturation of pure collagen reference samples. A new absorbing band is observed near the amide I band in the IR spectra, correlated to the onset of fluorescence signals in NLO images. Meanwhile, a strong decrease is observed in Second Harmonic signals, which are a structural probe of the fibrillar organization of the collagen at the micrometer scale. NLO microscopy therefore appears as a powerful tool to reveal collagen degradation in a non-invasive way. It should provide a relevant method to assess or monitor the condition of collagen-based materials in museum and archival collections and opens avenues for a broad range of applications regarding this widespread biological material.

  12. Correlative nonlinear optical microscopy and infrared nanoscopy reveals collagen degradation in altered parchments

    NASA Astrophysics Data System (ADS)

    Latour, Gaël; Robinet, Laurianne; Dazzi, Alexandre; Portier, François; Deniset-Besseau, Ariane; Schanne-Klein, Marie-Claire

    2016-05-01

    This paper presents the correlative imaging of collagen denaturation by nonlinear optical microscopy (NLO) and nanoscale infrared (IR) spectroscopy to obtain morphological and chemical information at different length scales. Such multiscale correlated measurements are applied to the investigation of ancient parchments, which are mainly composed of dermal fibrillar collagen. The main issue is to characterize gelatinization, the ultimate and irreversible alteration corresponding to collagen denaturation to gelatin, which may also occur in biological tissues. Key information about collagen and gelatin signatures is obtained in parchments and assessed by characterizing the denaturation of pure collagen reference samples. A new absorbing band is observed near the amide I band in the IR spectra, correlated to the onset of fluorescence signals in NLO images. Meanwhile, a strong decrease is observed in Second Harmonic signals, which are a structural probe of the fibrillar organization of the collagen at the micrometer scale. NLO microscopy therefore appears as a powerful tool to reveal collagen degradation in a non-invasive way. It should provide a relevant method to assess or monitor the condition of collagen-based materials in museum and archival collections and opens avenues for a broad range of applications regarding this widespread biological material.

  13. Correlative nonlinear optical microscopy and infrared nanoscopy reveals collagen degradation in altered parchments

    PubMed Central

    Latour, Gaël; Robinet, Laurianne; Dazzi, Alexandre; Portier, François; Deniset-Besseau, Ariane; Schanne-Klein, Marie-Claire

    2016-01-01

    This paper presents the correlative imaging of collagen denaturation by nonlinear optical microscopy (NLO) and nanoscale infrared (IR) spectroscopy to obtain morphological and chemical information at different length scales. Such multiscale correlated measurements are applied to the investigation of ancient parchments, which are mainly composed of dermal fibrillar collagen. The main issue is to characterize gelatinization, the ultimate and irreversible alteration corresponding to collagen denaturation to gelatin, which may also occur in biological tissues. Key information about collagen and gelatin signatures is obtained in parchments and assessed by characterizing the denaturation of pure collagen reference samples. A new absorbing band is observed near the amide I band in the IR spectra, correlated to the onset of fluorescence signals in NLO images. Meanwhile, a strong decrease is observed in Second Harmonic signals, which are a structural probe of the fibrillar organization of the collagen at the micrometer scale. NLO microscopy therefore appears as a powerful tool to reveal collagen degradation in a non-invasive way. It should provide a relevant method to assess or monitor the condition of collagen-based materials in museum and archival collections and opens avenues for a broad range of applications regarding this widespread biological material. PMID:27194180

  14. Correlative nonlinear optical microscopy and infrared nanoscopy reveals collagen degradation in altered parchments.

    PubMed

    Latour, Gaël; Robinet, Laurianne; Dazzi, Alexandre; Portier, François; Deniset-Besseau, Ariane; Schanne-Klein, Marie-Claire

    2016-01-01

    This paper presents the correlative imaging of collagen denaturation by nonlinear optical microscopy (NLO) and nanoscale infrared (IR) spectroscopy to obtain morphological and chemical information at different length scales. Such multiscale correlated measurements are applied to the investigation of ancient parchments, which are mainly composed of dermal fibrillar collagen. The main issue is to characterize gelatinization, the ultimate and irreversible alteration corresponding to collagen denaturation to gelatin, which may also occur in biological tissues. Key information about collagen and gelatin signatures is obtained in parchments and assessed by characterizing the denaturation of pure collagen reference samples. A new absorbing band is observed near the amide I band in the IR spectra, correlated to the onset of fluorescence signals in NLO images. Meanwhile, a strong decrease is observed in Second Harmonic signals, which are a structural probe of the fibrillar organization of the collagen at the micrometer scale. NLO microscopy therefore appears as a powerful tool to reveal collagen degradation in a non-invasive way. It should provide a relevant method to assess or monitor the condition of collagen-based materials in museum and archival collections and opens avenues for a broad range of applications regarding this widespread biological material. PMID:27194180

  15. Nanomechanics of collagen microfibrils

    PubMed Central

    Vesentini, Simone; Redaelli, Alberto; Gautieri, Alfonso

    2013-01-01

    Summary Collagen constitutes one third of the human proteome, providing mechanical stability, elasticity and strength to organisms and is thus the prime construction material in biology. Collagen is also the dominating material in the extracellular matrix where its stiffness controls cell differentiation, growth and pathology. We use atomistic-based hierarchical multiscale modeling to describe this complex biological material from the bottom up. This includes the use and development of large-scale computational modeling tools to investigate several aspects related to collagen-based tissues, including source of visco-elasticity and deformation mechanisms at the nanoscale level. The key innovation of this research is that until now, collagen materials have primarily been described at macroscopic scales, without explicitly understanding the mechanical contributions at the molecular and fibrillar levels. The major impact of this research will be the development of fundamental models of collagenous tissues, important to the design of new scaffolding biomaterials for regenerative medicine as well as for the understanding of collagen-related diseases. PMID:23885342

  16. Synthetic collagen fascicles for the regeneration of tendon tissue.

    PubMed

    Kew, S J; Gwynne, J H; Enea, D; Brookes, R; Rushton, N; Best, S M; Cameron, R E

    2012-10-01

    The structure of an ideal scaffold for tendon regeneration must be designed to provide a mechanical, structural and chemotactic microenvironment for native cellular activity to synthesize functional (i.e. load bearing) tissue. Collagen fibre scaffolds for this application have shown some promise to date, although the microstructural control required to mimic the native tendon environment has yet to be achieved allowing for minimal control of critical in vivo properties such as degradation rate and mass transport. In this report we describe the fabrication of a novel multi-fibre collagen fascicle structure, based on type-I collagen with failure stress of 25-49 MPa, approximating the strength and structure of native tendon tissue. We demonstrate a microscopic fabrication process based on the automated assembly of type-I collagen fibres with the ability to produce a controllable fascicle-like, structural motif allowing variable numbers of fibres per fascicle. We have confirmed that the resulting post-fabrication type-I collagen structure retains the essential phase behaviour, alignment and spectral characteristics of aligned native type-I collagen. We have also shown that both ovine tendon fibroblasts and human white blood cells in whole blood readily infiltrate the matrix on a macroscopic scale and that these cells adhere to the fibre surface after seven days in culture. The study has indicated that the synthetic collagen fascicle system may be a suitable biomaterial scaffold to provide a rationally designed implantable matrix material to mediate tendon repair and regeneration.

  17. Clinical performance of a dermal filler containing natural glycolic Acid and a polylactic Acid polymer: results of a clinical trial in human immunodeficiency virus subjects with facial lipoatrophy.

    PubMed

    Tagle, Jorge M; Macchetto, Pedro Cervantes; Durán Páramo, Rosa Margarita

    2010-02-01

    Lipoatrophy is a condition that affects certain individuals, most commonly those who are infected with the human immunodeficiency virus.(1-3) Injectable fillers are used for the treatment of these dermal contour deformities to smooth dermal depressions formed by the loss of volume. These dermal fillers (also known as soft tissue augmentation devices) can correct contour deformities caused by lipoatrophy in patients who are human immunodeficiency virus positive or negative. The product used in this study is a patented, second-generation, injectable, dermal collagen stimulator that combines glycolic acid and polylactic acid. The glycolic acid used is not a polymer, but rather an acid derived from sugar cane. Its chemical structure corresponds to that of an alpha-hydroxy acid. Glycolic acid is a well-characterized agent that is present in a number of cosmetic products. Polylactic acid is a synthetic, biocompatible, biodegradable, inert, synthetic polymer from the poly a-hydroxy-acid family that is believed to stimulate fibroblasts to produce more collagen, thus increasing facial volume. Together, polylactic acid and glycolic acid act in concert to 1) stimulate collagen production and 2) hydrate the outer layers of the skin. A multicenter, clinical investigation authorized by the Mexican Secretariat of Health was conducted between September 20, 2002, and September 19, 2004. This clinical study was conducted in male patients between 32 and 60 years of age with lipoatrophy as a result of highly active antiretroviral therapy for human immunodeficiency virus infection. The study objective was to measure the improvement of contour deformities after the injection of a dermal collagen stimulator containing glycolic acid and polylactic acid. In addition to safety, this dermal filler was assessed when used to correct volume deformities caused by lipoatrophy in subjects who are human immunodeficiency virus positive. Thirty male subjects participated and were treated as follows

  18. Hair follicle dermal stem cells regenerate the dermal sheath, repopulate the dermal papilla, and modulate hair type.

    PubMed

    Rahmani, Waleed; Abbasi, Sepideh; Hagner, Andrew; Raharjo, Eko; Kumar, Ranjan; Hotta, Akitsu; Magness, Scott; Metzger, Daniel; Biernaskie, Jeff

    2014-12-01

    The dermal papilla (DP) provide instructive signals required to activate epithelial progenitors and initiate hair follicle regeneration. DP cell numbers fluctuate over the hair cycle, and hair loss is associated with gradual depletion/atrophy of DP cells. How DP cell numbers are maintained in healthy follicles remains unclear. We performed in vivo fate mapping of adult hair follicle dermal sheath (DS) cells to determine their lineage relationship with DP and found that a subset of DS cells are retained following each hair cycle, exhibit self-renewal, and repopulate the DS and the DP with new cells. Ablating these hair follicle dermal stem cells and their progeny retarded hair regrowth and altered hair type specification, suggesting that they function to modulate normal DP function. This work identifies a bipotent stem cell within the adult hair follicle mesenchyme and has important implications toward restoration of hair growth after injury, disease, and aging.

  19. Collagen cross-linking in sun-exposed and unexposed sites of aged human skin

    NASA Technical Reports Server (NTRS)

    Yamauchi, M.; Prisayanh, P.; Haque, Z.; Woodley, D. T.

    1991-01-01

    A recently described nonreducible, acid-heat stable compound, histidinohydroxylysinonorleucine (HHL), is a collagen cross-link isolated from mature skin tissue. Its abundance is related to chronologic aging of skin. The present communication describes the quantity of HHL from aged human skin of the same individuals in sun-exposed (wrist) and unexposed (buttock) sites. Punch biopsies were obtained from these sites from nine people of age 60 or older. HHL contents (moles/mole of collagen) at these sites were for wrist 0.13 +/- 0.07 and for buttock 0.69 +/- 0.17 (mean +/- SD, p less than 0.001). In addition, it was found that acute irradiation of the cross-linked peptides with UVA (up to 250 J/cm2) and UVB (up to 1 J/cm2) had no effect on HHL structure. The same treatment significantly degraded another nonreducible, stable collagen cross-link, pyridinoline. The results suggest that chronic sunlight exposure may be associated with an impediment to normal maturation of human dermal collagen resulting in tenuous amount of HHL. Thus, the process of photoaging in dermal collagen is different from that of chronologic aging in human skin.

  20. A comparative study of skin cell activities in collagen and fibrin constructs.

    PubMed

    Law, Jia Xian; Musa, Faiza; Ruszymah, Bt Hj Idrus; El Haj, Alicia J; Yang, Ying

    2016-09-01

    Collagen and fibrin are widely used in tissue engineering due to their excellent biocompatibility and bioactivities that support in vivo tissue formation. These two hydrogels naturally present in different wound healing stages with different regulatory effects on cells, and both of them are mechanically weak in the reconstructed hydrogels. We conducted a comparative study by the growth of rat dermal fibroblasts or dermal fibroblasts and epidermal keratinocytes together in collagen and fibrin constructs respectively with and without the reinforcement of electrospun poly(lactic acid) nanofiber mesh. Cell proliferation, gel contraction and elastic modulus of the constructs were measured on the same gels at multiple time points during the 22 day culturing period using multiple non-destructive techniques. The results demonstrated considerably different cellular activities within the two types of constructs. Co-culturing keratinocytes with fibroblasts in the collagen constructs reduced the fibroblast proliferation, collagen contraction and mechanical strength at late culture point regardless of the presence of nanofibers. Co-culturing keratinocytes with fibroblasts in the fibrin constructs promoted fibroblast proliferation but exerted no influence on fibrin contraction and mechanical strength. The presence of nanofibers in the collagen and fibrin constructs played a favorable role on the fibroblast proliferation when keratinocytes were absent. Thus, this study exhibited new evidence of the strong cross-talk between keratinocytes and fibroblasts, which can be used to control fibroblast proliferation and construct contraction. This cross-talk activity is extracellular matrix-dependent in terms of the fibrous network morphology, density and strength. PMID:27349492

  1. Nitroxides are more efficient inhibitors of oxidative damage to calf skin collagen than antioxidant vitamins.

    PubMed

    Venditti, Elisabetta; Scirè, Andrea; Tanfani, Fabio; Greci, Lucedio; Damiani, Elisabetta

    2008-01-01

    Reactive oxygen species generated upon UV-A exposure appear to play a major role in dermal connective tissue transformations including degradation of skin collagen. Here we investigate on oxidative damage to collagen achieved by exposure to (i) UV-A irradiation and to (ii) AAPH-derived radicals and on its possible prevention using synthetic and natural antioxidants. Oxidative damage was identified through SDS-PAGE, circular dichroism spectroscopy and quantification of protein carbonyl residues. Collagen (2 mg/ml) exposed to UV-A and to AAPH-derived radicals was degraded in a time- and dose-dependent manner. Upon UV-A exposure, maximum damage was observable at 730 kJ/m2 UV-A, found to be equivalent to roughly 2 h of sunshine, while exposure to 5 mM AAPH for 2 h at 50 degrees C lead to maximum collagen degradation. In both cases, dose-dependent protection was achieved by incubation with muM concentrations of nitroxide radicals, where the extent of protection was shown to be dictated by their structural differences whereas the vitamins E and C proved less efficient inhibitors of collagen damage. These results suggest that nitroxide radicals may be able to prevent oxidative injury to dermal tissues in vivo alternatively to commonly used natural antioxidants.

  2. Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts.

    PubMed

    Wirohadidjojo, Yohanes Widodo; Budiyanto, Arief; Soebono, Hardyanto

    2016-09-01

    To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm⁻²) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined. PMID:27401663

  3. Site-specific rectocele repair with dermal graft augmentation: comparison of porcine dermal xenograft (Pelvicol) and human dermal allograft.

    PubMed

    Biehl, Roger C; Moore, Robert D; Miklos, John R; Kohli, Neeraj; Anand, Indu S; Mattox, T Fleming

    2008-01-01

    This study is a retrospective chart review comparing 195 women who underwent rectocele repair with either a porcine dermal xenograft or human allogenic cadaveric dermal graft augmentation over a two year period. A site-specific defect repair was completed prior to augmentation with the graft. Examinations were performed preoperatively and postoperatively using the pelvic organ prolapse quantification system. Questionnaires were used to assess constipation and dyspareunia. De novo dyspareunia and cure rates for constipation and dyspareunia were not statistically different between the two groups. Site-specific fascial rectocele repairs with xenograft or allograft augmentation were found to have similar complication rates as well as objective and subjective cure rates.

  4. Macitentan slows down the dermal fibrotic process in systemic sclerosis: in vitro findings.

    PubMed

    Corallo, C; Pecetti, G; Iglarz, M; Volpi, N; Franci, D; Montella, A; D' Onofrio, F; Nuti, R; Giordano, N

    2013-01-01

    Systemic sclerosis (or scleroderma) is an autoimmune disease characterized by skin and internal organ fibrosis, caused by microvascular dysfunction. The microvascular damage seems to be a consequence of an endothelial autoimmune response, followed by activation of the inflammatory cascade and massive deposition of collagen. Endothelin-1 (ET-1) contributes to the inflammatory and fibrotic processes by increasing the concentration of pro-inflammatory and pro-fibrotic cytokines, and it is considered one of the most relevant mediators of vascular damage in scleroderma. It is indeed found in very high concentration in serum of sclerodermic patients. Moreover, in these pathological conditions there is an increased expression of ET-1 receptors (ETA and ETB), which mediate the detrimental action of ET-1, and often a change of ETA/ETB ratio. The aim of the present study is to evaluate the in vitro effect of macitentan, an orally active tissue-targeting dual endothelin receptor antagonist, and its major metabolite (ACT-132577) on alpha smooth muscle actin (alphaSMA) expression, evaluated on dermal fibroblasts from healthy subjects and on dermal fibroblasts from lesional and non-lesional skin from sclerodermic patients. The combination of macitentan and its major metabolite reduced the levels of αSMA after 48 h in sclerodermic fibroblasts from lesional skin. No relevant changes in αSMA levels were found in fibroblasts from non-lesional skin, whose behavior is similar to that of dermal fibroblasts from healthy patients.

  5. [Development and regression of dermal corticosteroid atrophy. 2. Changes in compression rate].

    PubMed

    Hinz, E; Lubach, D

    1986-01-01

    In the 1st comm. results on development and remission of steroid-induced dermal atrophy were presented. Measurements were carried out with an instrument we constructed ourselves. This device enabled calculation of the rate of compression (CR) of a skin fold as well as determination of skin fold thickness (SFT). CR is specified in mm/log t. It is postulated that the CR depends on the viscosity of the basic substance and on the density of the collagen fiber skeletons led to an increase of SFT and CR. Loss of basic substance in quantitatively unchanged collagen skeletons led to a reduction of SFT and CR. In skin areas treated with corticosteroids, CR was reduced at roughly the same time as SFT. With the exception of hydrocortisone, the reduction was observed from about the 5th to the 10th d onwards in all products tested and became most pronounced after the 12th d. Following the end of steroid treatment (17th d), CR normalized within 6 to 10 d. It is concluded from the results that early steroid-induced dermal atrophy is caused by a lowering of the water/basic substance system. A steroid-specific inhibition of hyaluronic acid and glycosamine synthesis by the fibroblasts is assumed to be the cause of thickness loss. Skin areas treated with control ointments free of active substance displayed signs of increased hydratation.

  6. Thymosin β4 Promotes Dermal Healing.

    PubMed

    Kleinman, H K; Sosne, G

    2016-01-01

    No agent has been identified that significantly accelerates the repair of chronic dermal wounds in humans. Thymosin beta 4 (Tβ4) is a small, abundant, naturally occurring regenerative protein that is found in body fluids and inside cells. It was found to have angiogenic and antiinflammatory activity and to be high in platelets that aggregate at the wound site. Thus we used Tβ4 initially in dermal healing. It has since been shown to have many activities important in tissue protection, repair, and regeneration. Tβ4 increases the rate of dermal healing in various preclinical animal models, including diabetic and aged animals, and is active for burns as well. Tβ4 also accelerated the rate of repair in phase 2 trials with patients having pressure ulcers, stasis ulcers, and epidermolysis bullosa wounds. It is safe and well tolerated and will likely have additional uses in the skin and in injured organs for tissue repair and regeneration. PMID:27450738

  7. Type IV Collagen is a Novel DEJ Biomarker that is Reduced by Radiotherapy

    PubMed Central

    McGuire, J.D.; Gorski, J.P.; Dusevich, V.; Wang, Y.; Walker, M.P.

    2014-01-01

    The dental basement membrane (BM) is composed of collagen types IV, VI, VII, and XVII, fibronectin, and laminin and plays an inductive role in epithelial-mesenchymal interactions during tooth development. The BM is degraded and removed during later-stage tooth morphogenesis; however, its original position defines the location of the dentin-enamel junction (DEJ) in mature teeth. We recently demonstrated that type VII collagen is a novel component of the inner enamel organic matrix layer contiguous with the DEJ. Since it is frequently co-expressed with and forms functional complexes with type VII collagen, we hypothesized that type IV collagen should also be localized to the DEJ in mature human teeth. To identify collagen IV, we first evaluated defect-free erupted teeth from various donors. To investigate a possible stabilizing role, we also evaluated extracted teeth exposed to high-dose radiotherapy – teeth that manifest post-radiotherapy DEJ instability. We now show that type IV collagen is a component within the morphological DEJ of posterior and anterior teeth from individuals aged 18 to 80 yr. Confocal microscopy revealed that immunostained type IV collagen was restricted to the 5- to 10-µm-wide optical DEJ, while collagenase treatment or previous in vivo tooth-level exposure to > 60 Gray irradiation severely reduced immunoreactivity. This assignment was confirmed by Western blotting with whole-tooth crown and enamel extracts. Without reduction, type IV collagen contained macromolecular α-chains of 225 and 250 kDa. Compositionally, our results identify type IV collagen as the first macromolecular biomarker of the morphological DEJ of mature teeth. Given its network structure and propensity to stabilize the dermal-epidermal junction, we propose that a collagen-IV-enriched DEJ may, in part, explain its well-known fracture toughness, crack propagation resistance, and stability. In contrast, loss of type IV collagen may represent a biochemical rationale for the

  8. Collagen bioengineered systems: in situ advanced optical spatiotemporal analysis

    NASA Astrophysics Data System (ADS)

    Hwang, Yu Jer; Lang, Xuye; Granelli, Joseph; Turgman, Cassandra C.; Gigante, Jackie; Lyubovitsky, Julia G.

    2014-05-01

    The architecture of collagen is important in maintenance and regeneration of higher vertebrates' tissues. We had been studying the changes to this architecture with in situ multi-photon optical microscopy that combines nonlinear optical phenomena of second harmonic generation (SHG) and two-photon fluorescence (TPF) signals from collagen hydrogels prepared from different collagen solid content, polymerized at different temperatures, with different ions as well as modified with reducing sugars. We incubated 2 g/l collagen hydrogels with 0.1 M fructose at 37 °C and after about 20 days observed a significant induction of in situ fluorescence. The twophoton fluorescence emission was centered at about 460 nm for 730 nm excitation wavelength and shifted to 480 nm when we changed the excitation wavelength to 790 nm. The one-photon fluorescence emission was centered at about 416 nm when excitation was 330 nm. It red shifted and split into two peaks centered at about 430 nm and 460 nm for 370 nm excitation; 460 nm peak became predominant for 385 nm excitation and further shifted to 470 nm for 390 nm excitation. SHG and TPF imaging showed restructuring of hydrogels upon this modification. We will discuss these findings within the context of our ongoing dermal wound repair research.

  9. Coiled coils ensure the physiological ectodomain shedding of collagen XVII.

    PubMed

    Nishie, Wataru; Jackow, Joanna; Hofmann, Silke C; Franzke, Claus-Werner; Bruckner-Tuderman, Leena

    2012-08-24

    α-Helical coiled coils, frequent protein oligomerization motifs, are commonly observed in vital proteins. Here, using collagen XVII as an example, we provide evidence for a novel function of coiled coils in the regulation of ectodomain shedding. Transmembrane collagen XVII, an epithelial cell surface receptor, mediates dermal-epidermal adhesion in the skin, and its dysfunction is linked to human skin blistering diseases. The ectodomain of this collagen is constitutively shed from the cell surface by proteinases of a disintegrin and metalloprotease family; however, the mechanisms regulating shedding remain elusive. Here, we used site-specific mutagenesis to target the coiled-coil heptad repeats within the juxtamembranous, extracellular noncollagenous 16th A (NC16A) domain of collagen XVII. This resulted in a substantial increase of ectodomain shedding, which was not mediated by disintegrin and metalloproteases. Instead, conformational changes induced by the mutation(s) unmasked a furin recognition sequence that was used for cleavage. This study shows that apart from their functions in protein oligomerization, coiled coils can also act as regulators of ectodomain shedding depending on the biological context.

  10. Estimating terrestrial amphibian pesticide body burden through dermal exposure

    EPA Science Inventory

    Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Our study measured dermal uptake of pesticides of varying hydrophobicity (logKow) in frogs. Amphibians were indirectly exposed to one of five pesticide active...

  11. Mass transfer of large molecules through collagen and collagen-silica hybrid membranes

    NASA Astrophysics Data System (ADS)

    Jofre-Lora, Pedro

    Diabetes is a growing concern in the United States and around the world that must be addressed through new treatment options. Current standard treatment options of diabetes are limiting and have tremendous impacts on patient's lives. Emerging therapies, such as the implantation of encapsulated islets, are promising treatment options, but have not yet materialized due to unsolved problems with material properties. Hybrid silica-collagen membranes address some of these unsolved problems and are a promising material for cell encapsulation. However, the mass transfer properties of large molecules, such as insulin, TNF-alpha, IL1beta, and other important proteins in the etiology of diabetes, through these hybrid membranes are poorly characterized. In order to begin characterizing these properties, a device was constructed to accurately and efficiently measure the mass transfer of other similar large molecules, fluorescein isothiocyanate dextrans (FITC-dextran), through collagen-silica hybrid membranes. The device was used to measure diffusion coefficients of 4, 20, 40, and 150 kDa FITC-dextrans through non-silicified and silicified samples of 200 and 1000 Pa porcine skin collagen. Diffusion coefficients were found to be in the 10-7-10-6 cm2s -1 range, which is in agreement with previously published data for similar molecules through similar hydrogels. The effects of collagen stiffness, FITC-dextran molecular weight, and silicification treatment on diffusion were investigated. It was found that collagen stiffness and FITC-dextran molecular weight had a negative correlation with diffusion, whereas silicification treatment had no global impact on diffusion. The device created, and the results of this preliminary investigation, can be used to develop collagen-silica hybrid membranes as an alternative material for cell encapsulation in a forward-design manner.

  12. Hydroxyapatite reinforced collagen scaffolds with improved architecture and mechanical properties.

    PubMed

    Kane, Robert J; Weiss-Bilka, Holly E; Meagher, Matthew J; Liu, Yongxing; Gargac, Joshua A; Niebur, Glen L; Wagner, Diane R; Roeder, Ryan K

    2015-04-01

    Hydroxyapatite (HA) reinforced collagen scaffolds have shown promise for synthetic bone graft substitutes and tissue engineering scaffolds. Freeze-dried HA-collagen scaffolds are readily fabricated and have exhibited osteogenicity in vivo, but are limited by an inherent scaffold architecture that results in a relatively small pore size and weak mechanical properties. In order to overcome these limitations, HA-collagen scaffolds were prepared by compression molding HA reinforcements and paraffin microspheres within a suspension of concentrated collagen fibrils (∼ 180 mg/mL), cross-linking the collagen matrix, and leaching the paraffin porogen. HA-collagen scaffolds exhibited an architecture with high porosity (85-90%), interconnected pores ∼ 300-400 μm in size, and struts ∼ 3-100 μm in thickness containing 0-80 vol% HA whisker or powder reinforcements. HA reinforcement enabled a compressive modulus of up to ∼ 1 MPa, which was an order of magnitude greater than unreinforced collagen scaffolds. The compressive modulus was also at least one order of magnitude greater than comparable freeze-dried HA-collagen scaffolds and two orders of magnitude greater than absorbable collagen sponges used clinically. Moreover, scaffolds reinforced with up to 60 vol% HA exhibited fully recoverable elastic deformation upon loading to 50% compressive strain for at least 100,000 cycles. Thus, the scaffold mechanical properties were well-suited for surgical handling, fixation, and bearing osteogenic loads during bone regeneration. The scaffold architecture, permeability, and composition were shown to be conducive to the infiltration and differentiation of adipose-derive stromal cells in vitro. Acellular scaffolds were demonstrated to induce angiogenesis and osteogenesis after subcutaneous ectopic implantation by recruiting endogenous cell populations, suggesting that the scaffolds were osteoinductive.

  13. Injectable poly-L: -lactic acid: a novel sculpting agent for the treatment of dermal fat atrophy after severe acne.

    PubMed

    Sadove, Richard

    2009-01-01

    Acne vulgaris affects up to 80% of people 11 to 30 years of age, and scarring can occur for up to 95% of these patients. Scarring may be pitted or hypertrophic in nature, although in most cases it is atrophic. Atrophic acne scarring follows dermal collagen and fat loss after moderate to severe acne infection. Injectable poly-L-acid (PLLA) is a biocompatible, biodegradable, synthetic polymer device that is hypothesized to enhance dermal volume via the endogenous production of fibroblasts and, subsequently, collagen. The gradual improvements in cutaneous volume observed after treatment with injectable PLLA have been noted to last up to 2 years. The case studies presented describe the use of injectable PLLA to correct dermal fat loss in macular atrophic acne scarring of the cheeks. Two female patients underwent three treatment sessions with injectable PLLA over a 12-week period. At each treatment session, the reconstituted product was injected into the deep dermis under the depressed portion of the scar. Both patients were extremely pleased with their results at, respectively, 1- and 4-year follow-up evaluations. Patients experienced minimal swelling and redness after injection and no product-related adverse events such as papule and/or nodule formation. The author believes these data suggest that injectable PLLA is a good treatment option for the correction of macular atropic scarring with thin dermis (off-label use), particularly compared with other injectable fillers currently used for this indication that have shorter durations of effect. PMID:18923863

  14. Dermal lymphatic dilation in a mouse model of alopecia areata.

    PubMed

    Sundberg, John P; Pratt, C Herbert; Silva, Kathleen A; Kennedy, Victoria E; Stearns, Timothy M; Sundberg, Beth A; King, Lloyd E; HogenEsch, Harm

    2016-04-01

    Mouse models of various types of inflammatory skin disease are often accompanied by increased dermal angiogenesis. The C3H/HeJ inbred strain spontaneously develops alopecia areata (AA), a cell mediated autoimmune disorder that can be controllably expanded using full thickness skin grafts to young unaffected mice. This provides a reproducible and progressive model for AA in which the vascularization of the skin can be examined. Mice receiving skin grafts from AA or normal mice were evaluated at 5, 10, 15, and 20 weeks after engraftment. Lymphatics are often overlooked as they are small slit-like structures above the hair follicle that resemble artifact-like separation of collagen bundles with some fixatives. Lymphatics are easily detected using lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) by immunohistochemistry to label their endothelial cells. Using LYVE1, there were no changes in distribution or numbers of lymphatics although they were more prominent (dilated) in the mice with AA. Lyve1 transcripts were not significantly upregulated except at 10 weeks after skin grafting when clinical signs of AA first become apparent. Other genes involved with vascular growth and dilation or movement of immune cells were dysregulated, mostly upregulated. These findings emphasize aspects of AA not commonly considered and provide potential targets for therapeutic intervention.

  15. Dermal lymphatic dilation in a mouse model of alopecia areata.

    PubMed

    Sundberg, John P; Pratt, C Herbert; Silva, Kathleen A; Kennedy, Victoria E; Stearns, Timothy M; Sundberg, Beth A; King, Lloyd E; HogenEsch, Harm

    2016-04-01

    Mouse models of various types of inflammatory skin disease are often accompanied by increased dermal angiogenesis. The C3H/HeJ inbred strain spontaneously develops alopecia areata (AA), a cell mediated autoimmune disorder that can be controllably expanded using full thickness skin grafts to young unaffected mice. This provides a reproducible and progressive model for AA in which the vascularization of the skin can be examined. Mice receiving skin grafts from AA or normal mice were evaluated at 5, 10, 15, and 20 weeks after engraftment. Lymphatics are often overlooked as they are small slit-like structures above the hair follicle that resemble artifact-like separation of collagen bundles with some fixatives. Lymphatics are easily detected using lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) by immunohistochemistry to label their endothelial cells. Using LYVE1, there were no changes in distribution or numbers of lymphatics although they were more prominent (dilated) in the mice with AA. Lyve1 transcripts were not significantly upregulated except at 10 weeks after skin grafting when clinical signs of AA first become apparent. Other genes involved with vascular growth and dilation or movement of immune cells were dysregulated, mostly upregulated. These findings emphasize aspects of AA not commonly considered and provide potential targets for therapeutic intervention. PMID:26960166

  16. Initial bone-implant interfaces of submergible and supramergible endosseous single-crystal sapphire implants.

    PubMed

    Akagawa, Y; Hashimoto, M; Kondo, N; Satomi, K; Takata, T; Tsuru, H

    1986-01-01

    Three types of bone-single-crystal sapphire implant interfaces were histologically determined in submergible and supramergible implant: direct bone apposition (type I), thin connective tissue with poor collagen fibers (type II), and dense fibrous connective tissue (type III). Type I interface was predominant and type III interface was sparsely seen in submergible implants. In contrast to these findings, type III interfaces frequently appeared in supramergible implants, primarily at the apical region. These differences were considered to occur by the biomechanical variable of postoperative healing.

  17. Collagen Fibrils: Nanoscale Ropes

    PubMed Central

    Bozec, Laurent; van der Heijden, Gert; Horton, Michael

    2007-01-01

    The formation of collagen fibrils from staggered repeats of individual molecules has become “accepted” wisdom. However, for over thirty years now, such a model has failed to resolve several structural and functional questions. In a novel approach, it was found, using atomic force microscopy, that tendon collagen fibrils are composed of subcomponents in a spiral disposition—that is, their structure is similar to that of macroscale ropes. Consequently, this arrangement was modeled and confirmed using elastic rod theory. This work provides new insight into collagen fibril structure and will have wide application—from the design of scaffolds for tissue engineering and a better understanding of pathogenesis of diseases of bone and tendon, to the conservation of irreplaceable parchment-based museum exhibits. PMID:17028135

  18. Collagen in organ development

    NASA Technical Reports Server (NTRS)

    Hardman, P.; Spooner, B. S.

    1992-01-01

    It is important to know whether microgravity will adversely affect developmental processes. Collagens are macromolecular structural components of the extracellular matrix (ECM) which may be altered by perturbations in gravity. Interstitial collagens have been shown to be necessary for normal growth and morphogenesis in some embryonic organs, and in the mouse salivary gland, the biosynthetic pattern of these molecules changes during development. Determination of the effects of microgravity on epithelial organ development must be preceded by crucial ground-based studies. These will define control of normal synthesis, secretion, and deposition of ECM macromolecules and the relationship of these processes to morphogenesis.

  19. Own Experience From The Use Of A Substitute Of An Allogeneic Acellular Dermal Matrix Revitalized With In Vitro Cultured Skin Cells In Clinical Practice.

    PubMed

    Łabuś, Wojciech; Kawecki, Marek; Glik, Justyna; Maj, Mariusz; Kitala, Diana; Misiuga, Marcelina; Klama-Baryła, Agnieszka; Kraut, Małgorzata; Nowak, Mariusz

    2015-10-01

    As a result of the removal of cells from human allogeneic dermis, a collagen scaffold is obtained, which can be populated de novo with autologous/allogeneic skin cells and transplanted onto the area of skin loss. The optimal method for production of acellular dermal matrices (ADM) has been selected. Three female patients (a mean age of 54 years) were subjected to the transplantation of either autologous or allogeneic keratinocytes and fibroblasts into the holes of acellular dermal matrix (ADM) mesh graft. The method for burn wound treatment based on the use of a viable dermal-epidermal skin substitute (based on ADM and in vitro cultured fibroblasts and keratinocytes) may be the optimal method of burn treatment. PMID:26812752

  20. Own Experience From The Use Of A Substitute Of An Allogeneic Acellular Dermal Matrix Revitalized With In Vitro Cultured Skin Cells In Clinical Practice.

    PubMed

    Łabuś, Wojciech; Kawecki, Marek; Glik, Justyna; Maj, Mariusz; Kitala, Diana; Misiuga, Marcelina; Klama-Baryła, Agnieszka; Kraut, Małgorzata; Nowak, Mariusz

    2015-10-01

    As a result of the removal of cells from human allogeneic dermis, a collagen scaffold is obtained, which can be populated de novo with autologous/allogeneic skin cells and transplanted onto the area of skin loss. The optimal method for production of acellular dermal matrices (ADM) has been selected. Three female patients (a mean age of 54 years) were subjected to the transplantation of either autologous or allogeneic keratinocytes and fibroblasts into the holes of acellular dermal matrix (ADM) mesh graft. The method for burn wound treatment based on the use of a viable dermal-epidermal skin substitute (based on ADM and in vitro cultured fibroblasts and keratinocytes) may be the optimal method of burn treatment.

  1. Novel in vitro culture condition improves the stemness of human dermal stem/progenitor cells.

    PubMed

    Shim, Joong Hyun; Lee, Tae Ryong; Shin, Dong Wook

    2013-12-01

    Cell therapy using adult stem cells has emerged as a potentially new approach for the treatment of various diseases. Therefore, it is an essential procedure to maintain the stemness of adult stem cells for clinical treatment. We previously reported that human dermal stem/progenitor cells (hDSPCs) can be enriched using collagen type IV. However, hDSPCs gradually lose their stem cell properties as in vitro passages continue. In the present study, we developed optimized in vitro culture condition to improve the stemness of these hDSPCs. To evaluate whether the stemness of hDSPCs is well sustained in various culture conditions, we measured the expression levels of SOX2, NANOG, and S100B, which are well-known representative dermal progenitor markers. We observed that hDSPCs grown in three-dimensional (3D) culture condition had higher expression levels of those markers compared with hDSPCs grown in two-dimensional (2D) culture condition. Under the 3D culture condition, we further demonstrated that a high glucose (4.5 g/L) concentration enhanced the expression levels of the dermal progenitor markers, whereas O(2) concentration did not affect. We also found that skin-derived precursor (SKP) culture medium was the most effective, among various culture media, in increasing the dermal progenitor marker expression. We finally demonstrated that this optimized culture condition enhanced the expression level of human telomerase reverse transcriptase (hTERT), the proliferation, and the multipotency of hDSPCs, an important characteristic of stem cells. Taken together, these results suggested that this novel in vitro culture condition improves the stemness of hDSPCs.

  2. Topologically defined composites of collagen types I and V as in vitro cell culture scaffolds.

    PubMed

    Franke, Katja; Sapudom, Jiranuwat; Kalbitzer, Liv; Anderegg, Ulf; Pompe, Tilo

    2014-06-01

    Cell fate is known to be triggered by cues from the extracellular matrix, including its chemical, biological and physical characteristics. Specifically, mechanical and topological properties are increasingly recognized as important signals. The aim of this work was to provide an easily accessible biomimetic in vitro platform of topologically defined collagen I matrices to dissect cell behaviour under various conditions in vitro. We reconstituted covalently bound layers of three-dimensional (3-D) networks of collagen type I and collagen type V with a defined network topology. A new erosion algorithm enabled us to analyse the mean pore diameter and fibril content, while the mean fibril diameter was examined by an autocorrelation method. Different concentrations and ratios of collagen I and V resulted in pore diameters from 2.4 to 4.5μm and fibril diameters from 0.6 to 0.8μm. A comparison of telopeptide intact collagen I to telopeptide deficient collagen I revealed obvious differences in network structure. The good correlation of the topological data to measurements of network stiffness as well as invasion of human dermal fibroblasts proves that the topological analysis provides meaningful measures of the functional characteristics of the reconstituted 3-D collagen matrices.

  3. Nanostructure and mechanics of mummified type I collagen from the 5300-year-old Tyrolean Iceman

    PubMed Central

    Janko, Marek; Zink, Albert; Gigler, Alexander M.; Heckl, Wolfgang M.; Stark, Robert W.

    2010-01-01

    Skin protects the body from pathogens and degradation. Mummified skin in particular is extremely resistant to decomposition. External influences or the action of micro-organisms, however, can degrade the connective tissue and lay the subjacent tissue open. To determine the degree of tissue preservation in mummified human skin and, in particular, the reason for its durability, we investigated the structural integrity of its main protein, type I collagen. We extracted samples from the Neolithic glacier mummy known as ‘the Iceman’. Atomic force microscopy (AFM) revealed collagen fibrils that had characteristic banding patterns of 69 ± 5 nm periodicity. Both the microstructure and the ultrastructure of dermal collagen bundles and fibrils were largely unaltered and extremely well preserved by the natural conservation process. Raman spectra of the ancient collagen indicated that there were no significant modifications in the molecular structure. However, AFM nanoindentation measurements showed slight changes in the mechanical behaviour of the fibrils. Young's modulus of single mummified fibrils was 4.1 ± 1.1 GPa, whereas the elasticity of recent collagen averages 3.2 ± 1.0 GPa. The excellent preservation of the collagen indicates that dehydration owing to freeze-drying of the collagen is the main process in mummification and that the influence of the degradation processes can be addressed, even after 5300 years. PMID:20356896

  4. Regulation of Collagen Turnover in Human Skin Fibroblasts Exposed to a Gadolinium-Based Contrast Agent

    PubMed Central

    Bhagavathula, Narasimharao; DaSilva, Marissa; Aslam, Muhammad N.; Dame, Michael K.; Warner, Roscoe L.; Xu, Yiru; Fisher, Gary J.; Johnson, Kent J.; Swartz, Richard; Varani, James

    2010-01-01

    Objective Nephrogenic systemic fibrosis (NSF) is a clinical syndrome linked with exposure in renal failure patients to gadolinium-based contrast agents (GBCAs) during magnetic resonance imaging. Recently, we demonstrated that GBCA exposure led to increased matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) levels in human skin fibroblasts. The goals of the present work were to assess the relationship between altered MMP-1 / TIMP-1 expression and collagen production / deposition, and the intracellular signaling events that lead from GBCA stimulation to altered MMP-1 and TIMP-1 production. Materials and Methods Human dermal fibroblasts were treated with one of the currently used GBCAs (Omniscan). Proliferation was quantified as were levels of MMP-1, TIMP-1, procollagen type I and collagen type I. Signaling events were concomitantly assessed, and signaling inhibitors were used. Results Fibroblasts exposed to Omniscan had increases in both MMP-1 and TIMP-1 levels. Omniscan treatment interfered with collagen turnover, leading to increased type I collagen deposition without an increase in type I procollagen production. U0126, an inhibitor of mitogen-activated protein kinase signaling, and LY294002, a phosphatidylinositol-3 kinase inhibitor, reduced MMP-1 levels. U0126 also reduced TIMP-1 levels, but LY294002 increased TIMP-1. Conclusion These data provide evidence for complex regulation of collagen deposition in Omniscan-treated skin. They suggest that the major effect of Omniscan exposure is on an enzyme / inhibitor system that regulates collagen breakdown rather than on collagen production, per se. PMID:19561517

  5. Nanostructure and mechanics of mummified type I collagen from the 5300-year-old Tyrolean Iceman.

    PubMed

    Janko, Marek; Zink, Albert; Gigler, Alexander M; Heckl, Wolfgang M; Stark, Robert W

    2010-08-01

    Skin protects the body from pathogens and degradation. Mummified skin in particular is extremely resistant to decomposition. External influences or the action of micro-organisms, however, can degrade the connective tissue and lay the subjacent tissue open. To determine the degree of tissue preservation in mummified human skin and, in particular, the reason for its durability, we investigated the structural integrity of its main protein, type I collagen. We extracted samples from the Neolithic glacier mummy known as 'the Iceman'. Atomic force microscopy (AFM) revealed collagen fibrils that had characteristic banding patterns of 69 +/- 5 nm periodicity. Both the microstructure and the ultrastructure of dermal collagen bundles and fibrils were largely unaltered and extremely well preserved by the natural conservation process. Raman spectra of the ancient collagen indicated that there were no significant modifications in the molecular structure. However, AFM nanoindentation measurements showed slight changes in the mechanical behaviour of the fibrils. Young's modulus of single mummified fibrils was 4.1 +/- 1.1 GPa, whereas the elasticity of recent collagen averages 3.2 +/- 1.0 GPa. The excellent preservation of the collagen indicates that dehydration owing to freeze-drying of the collagen is the main process in mummification and that the influence of the degradation processes can be addressed, even after 5300 years.

  6. Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog

    PubMed Central

    Momose, Takehito; Miyaji, Hirofumi; Kato, Akihito; Ogawa, Kosuke; Yoshida, Takashi; Nishida, Erika; Murakami, Syusuke; Kosen, Yuta; Sugaya, Tsutomu; Kawanami, Masamitsu

    2016-01-01

    Objective: Collagen hydrogel scaffold exhibits bio-safe properties and facilitates periodontal wound healing. However, regenerated tissue volume is insufficient. Fibroblast growth factor-2 (FGF2) up-regulates cell behaviors and subsequent wound healing. We evaluated whether periodontal wound healing is promoted by application of collagen hydrogel scaffold in combination with FGF2 in furcation defects in beagle dogs. Methods: Collagen hydrogel was fabricated from bovine type I collagen with an ascorbate-copper ion cross-linking system. Collagen hydrogel was mingled with FGF2 and injected into sponge-form collagen. Subsequently, FGF2 (50 µg)/collagen hydrogel scaffold and collagen hydrogel scaffold alone were implanted into class II furcation defects in dogs. In addition, no implantation was performed as a control. Histometric parameters were assessed at 10 days and 4 weeks after surgery. Result: FGF2 application to scaffold promoted considerable cell and tissue ingrowth containing numerous cells and blood vessel-like structure at day 10. At 4 weeks, reconstruction of alveolar bone was stimulated by implantation of scaffold loaded with FGF2. Furthermore, periodontal attachment, consisting of cementum-like tissue, periodontal ligament-like tissue and Sharpey’s fibers, was also repaired, indicating that FGF2-loaded scaffold guided self-assembly and then re-established the function of periodontal organs. Aberrant healing, such as ankylosis and root resorption, was not observed. Conclusion: FGF2-loaded collagen hydrogel scaffold possessed excellent biocompatibility and strongly promoted periodontal tissue engineering, including periodontal attachment re-organization. PMID:27583044

  7. Long-term effects of knitted silk-collagen sponge scaffold on anterior cruciate ligament reconstruction and osteoarthritis prevention.

    PubMed

    Shen, Weiliang; Chen, Xiao; Hu, Yejun; Yin, Zi; Zhu, Ting; Hu, Jiajie; Chen, Jialin; Zheng, Zefeng; Zhang, Wei; Ran, Jisheng; Heng, Boon Chin; Ji, Junfeng; Chen, Weishan; Ouyang, Hong-Wei

    2014-09-01

    Anterior cruciate ligament (ACL) is difficult to heal after injury due to the dynamic fluid environment of joint. Previously, we have achieved satisfactory regeneration of subcutaneous tendon/ligament with knitted silk-collagen sponge scaffold due to its specific "internal-space-preservation" property. This study aims to investigate the long-term effects of knitted silk-collagen sponge scaffold on ACL regeneration and osteoarthritis prevention. The knitted silk-collagen sponge scaffold was fabricated and implanted into a rabbit ACL injury model. The knitted silk-collagen sponge scaffold was found to enhance migration and adhesion of spindle-shaped cells into the scaffold at 2 months post-surgery. After 6 months, ACL treated with the knitted silk-collagen sponge scaffold exhibited increased expression of ligament genes and better microstructural morphology. After 18 months, the knitted silk-collagen sponge scaffold-treated group had more mature ligament structure and direct ligament-to-bone healing. Implanted knitted silk-collagen sponge scaffolds degraded much more slowly compared to subcutaneous implantation. Furthermore, the knitted silk-collagen sponge scaffold effectively protected joint surface cartilage and preserved joint space for up to 18 months post-surgery. These findings thus demonstrated that the knitted silk-collagen sponge scaffold can regenerate functional ACL and prevent osteoarthritis in the long-term, suggesting its clinical use as a functional bioscaffold for ACL reconstruction.

  8. Corneal Collagen Cross-Linking

    PubMed Central

    Jankov II, Mirko R.; Jovanovic, Vesna; Nikolic, Ljubisa; Lake, Jonathan C.; Kymionis, Georgos; Coskunseven, Efekan

    2010-01-01

    Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A (UVA) is a new technique of corneal tissue strengthening by using riboflavin as a photosensitizer and UVA to increase the formation of intra and interfibrillar covalent bonds by photosensitized oxidation. Keratocyte apoptosis in the anterior segment of the corneal stroma all the way down to a depth of about 300 microns has been described and a demarcation line between the treated and untreated cornea has been clearly shown. It is important to ensure that the cytotoxic threshold for the endothelium has not been exceeded by strictly respecting the minimal corneal thickness. Confocal microscopy studies show that repopulation of keratocytes is already visible 1 month after the treatment, reaching its pre-operative quantity and quality in terms of functional morphology within 6 months after the treatment. The major indication for the use of CXL is to inhibit the progression of corneal ectasias, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photoablation. This treatment has also been used to treat infectious corneal ulcers with apparent favorable results. Combination with other treatments, such as intracorneal ring segment implantation, limited topography-guided photoablation and conductive keratoplasty have been used with different levels of success. PMID:20543933

  9. A Comparison of Conventional Collagen Sponge and Collagen-Gelatin Sponge in Wound Healing

    PubMed Central

    Jinno, Chizuru; Morimoto, Naoki; Ito, Ran; Sakamoto, Michiharu; Ogino, Shuichi; Taira, Tsuguyoshi; Suzuki, Shigehiko

    2016-01-01

    The objective of this study was to compare the effectiveness of the collagen-gelatin sponge (CGS) with that of the collagen sponge (CS) in dermis-like tissue regeneration. CGS, which achieves the sustained release of basic fibroblast growth factor (bFGF), is a promising material in wound healing. In the present study, we evaluated and compared CGSs and conventional CSs. We prepared 8 mm full-thickness skin defects on the backs of rats. Either CGSs or CSs were impregnated with normal saline solution (NSS) or 7 μg/cm2 of bFGF solution and implanted into the defects. At 1 and 2 weeks after implantation, tissue specimens were obtained from the rats of each group (n = 3, total n = 24). The wound area, neoepithelial length, dermis-like tissue area, and the number and area of capillaries were evaluated at 1 and 2 weeks after implantation. There were no significant differences in the CGS without bFGF and CS groups. Significant improvements were observed in the neoepithelial length, the dermis-like tissue area, and the number of newly formed capillaries in the group of rats that received CGSs impregnated with bFGF. The effects on epithelialization, granulation, and vascularization of wound healing demonstrated that, as a scaffold, CGSs are equal or superior to conventional CSs. PMID:27218103

  10. LINKING DERMAL MODELING AND LOADING DATA TO PREDICT LONG-TERM DOSES FROM INTERMITTENT DERMAL CONTACT

    EPA Science Inventory

    In this paper we assess dermal exposure and dose resulting from intermittent contact with residue-contaminated surfaces. These estimates require an understanding of (1) the quantitative relationship between exposure and absorbed dose; (2) the impact of intermittent exposure on ...

  11. Cochlear Implants

    MedlinePlus

    ... electrodes are inserted. The electronic device at the base of the electrode array is then placed under ... FDA approval for implants The Food and Drug Administration (FDA) regulates cochlear implant devices for both adults ...

  12. Dental Implants.

    PubMed

    Zohrabian, Vahe M; Sonick, Michael; Hwang, Debby; Abrahams, James J

    2015-10-01

    Dental implants restore function to near normal in partially or completely edentulous patients. A root-form implant is the most frequently used type of dental implant today. The basis for dental implants is osseointegration, in which osteoblasts grow and directly integrate with the surface of titanium posts surgically embedded into the jaw. Radiologic assessment is critical in the preoperative evaluation of the dental implant patient, as the exact height, width, and contour of the alveolar ridge must be determined. Moreover, the precise locations of the maxillary sinuses and mandibular canals, as well as their relationships to the site of implant surgery must be ascertained. As such, radiologists must be familiar with implant design and surgical placement, as well as augmentation procedures utilized in those patients with insufficient bone in the maxilla and mandible to support dental implants.

  13. Adamts5 Deletion Blocks Murine Dermal Repair through CD44-mediated Aggrecan Accumulation and Modulation of Transforming Growth Factor β1 (TGFβ1) Signaling*

    PubMed Central

    Velasco, Jennifer; Li, Jun; DiPietro, Luisa; Stepp, Mary Ann; Sandy, John D.; Plaas, Anna

    2011-01-01

    ADAMTS5 has been implicated in the degradation of cartilage aggrecan in human osteoarthritis. Here, we describe a novel role for the enzyme in the regulation of TGFβ1 signaling in dermal fibroblasts both in vivo and in vitro. Adamts5−/− mice, generated by deletion of exon 2, exhibit impaired contraction and dermal collagen deposition in an excisional wound healing model. This was accompanied by accumulation in the dermal layer of cell aggregates and fibroblastic cells surrounded by a pericellular matrix enriched in full-length aggrecan. Adamts5−/− wounds exhibit low expression (relative to wild type) of collagen type I and type III but show a persistently elevated expression of tgfbRII and alk1. Aggrecan deposition and impaired dermal repair in Adamts5−/− mice are both dependent on CD44, and Cd44−/−/Adamts5−/− mice display robust activation of TGFβ receptor II and collagen type III expression and the dermal regeneration seen in WT mice. TGFβ1 treatment of newborn fibroblasts from wild type mice results in Smad2/3 phosphorylation, whereas cells from Adamts5−/− mice phosphorylate Smad1/5/8. The altered TGFβ1 response in the Adamts5−/− cells is dependent on the presence of aggrecan and expression of CD44, because Cd44−/−/Adamts5−/− cells respond like WT cells. We propose that ADAMTS5 deficiency in fibrous tissues results in a poor repair response due to the accumulation of aggrecan in the pericellular matrix of fibroblast progenitor cells, which prevents their transition to mature fibroblasts. Thus, the capacity of ADAMTS5 to modulate critical tissue repair signaling events suggests a unique role for this enzyme, which sets it apart from other members of the ADAMTS family of proteases. PMID:21566131

  14. Structure and function of collagen types

    SciTech Connect

    Mayne, R.; Burgeson, R.E.

    1987-01-01

    This book contains 10 chapters. Some of the chapter titles are: The Classical Collagens: Types I, II, and III; Type IV Collagen; Type IX Collagen; and Analysis of Collagen Structure by Molecular Biology Techniques.

  15. Effect of orally administered collagen hydrolysate on gene expression profiles in mouse skin: a DNA microarray analysis.

    PubMed

    Oba, Chisato; Ito, Kyoko; Ichikawa, Satomi; Morifuji, Masashi; Nakai, Yuji; Ishijima, Tomoko; Abe, Keiko; Kawahata, Keiko

    2015-08-01

    Dietary collagen hydrolysate has been hypothesized to improve skin barrier function. To investigate the effect of long-term collagen hydrolysate administration on the skin, we evaluated stratum corneum water content and skin elasticity in intrinsically aged mice. Female hairless mice were fed a control diet or a collagen hydrolysate-containing diet for 12 wk. Stratum corneum water content and skin elasticity were gradually decreased in chronologically aged control mice. Intake of collagen hydrolysate significantly suppressed such changes. Moreover, we used DNA microarrays to analyze gene expression in the skin of mice that had been administered collagen hydrolysate. Twelve weeks after the start of collagen intake, no significant differences appeared in the gene expression profile compared with the control group. However, 1 wk after administration, 135 genes were upregulated and 448 genes were downregulated in the collagen group. This suggests that gene changes preceded changes of barrier function and elasticity. We focused on several genes correlated with functional changes in the skin. Gene Ontology terms related to epidermal cell development were significantly enriched in upregulated genes. These skin function-related genes had properties that facilitate epidermal production and differentiation while suppressing dermal degradation. In conclusion, our results suggest that altered gene expression at the early stages after collagen administration affects skin barrier function and mechanical properties. Long-term oral intake of collagen hydrolysate improves skin dysfunction by regulating genes related to production and maintenance of skin tissue.

  16. 40 CFR 798.2250 - Dermal toxicity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... susceptible tissues. (c) Principle of the test method. The test substance is applied daily to the skin in... the vehicle on toxicity of and penetration of the skin by the test substance should be taken into... a life span. (2) Dose in a dermal test is the amount of test substance applied to the skin...

  17. 40 CFR 798.2250 - Dermal toxicity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... susceptible tissues. (c) Principle of the test method. The test substance is applied daily to the skin in... the vehicle on toxicity of and penetration of the skin by the test substance should be taken into... a life span. (2) Dose in a dermal test is the amount of test substance applied to the skin...

  18. Focal dermal hypoplasia: a rare case report.

    PubMed

    Srinivas, Sahana M; Hiremagalore, Ravi

    2015-01-01

    Focal dermal hypoplasia (Goltz syndrome) is a rare genetic multisystem disorder primarily involving the skin, skeletal system, eyes, and face. We report the case of an eight-month-old female child who presented with multiple hypopigmented atrophic macules along the lines of blaschko, skeletal anomalies, umbilical hernia, developmental delay, hypoplastic nails, syndactyly, and lobster claw deformity characteristic of Goltz syndrome. PMID:25657436

  19. Spatio-Temporal Modification of Collagen Scaffolds Mediated by Triple Helical Propensity

    PubMed Central

    Wang, Allen Y.; Foss, Catherine A.; Leong, Shirley; Mo, Xiao; Pomper, Martin G.; Yu, Seungju M.

    2011-01-01

    Functionalized collagen that incorporates exogenous compounds may offer new and improved biomaterials applications, especially in drug-delivery, multifunctional implants, and tissue engineering. To that end, we developed a specific and reversible collagen modification technique utilizing associative chain interactions between synthetic collagen mimetic peptide (CMP) [(ProHypGly)x; Hyp = hydroxyproline] and type I collagen. Here we show temperature-dependent collagen binding and subsequent release of a series of CMPs with varying chain lengths indicating a triple helical propensity driven binding mechanism. The binding took place when melted, single-strand CMPs were allowed to fold while in contact with reconstituted type I collagens. The binding affinity is highly specific to collagen as labeled CMP bound to nanometer scale periodic positions on type I collagen fibers and could be used to selectively image collagens in ex vivo human liver tissue. When heated to physiological temperature, bound CMPs discharged from the collagen at a sustained rate that correlated with CMP’s triple helical propensity, suggesting that sustainability is mediated by dynamic collagen–CMP interactions. We also report on the spatially defined modification of collagen film with linear and multi-arm poly(ethylene glycol)-CMP conjugates; at 37 °C, these PEG-CMP conjugates exhibited temporary cell repelling activity lasting up to 9 days. These results demonstrate new opportunities for targeting pathologic collagens for diagnostic or therapeutic applications and for fabricating multifunctional collagen coatings and scaffolds that can temporally and spatially control the behavior of cells associated with the collagen matrices. PMID:18547103

  20. Genetic disorders of collagen.

    PubMed Central

    Tsipouras, P; Ramirez, F

    1987-01-01

    Osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan syndrome form a group of genetic disorders of connective tissue. These disorders exhibit remarkable clinical heterogeneity which reflects their underlying biochemical and molecular differences. Defects in collagen types I and III have been found in all three syndromes. PMID:3543367

  1. Collagen hydrolysate based collagen/hydroxyapatite composite materials

    NASA Astrophysics Data System (ADS)

    Ficai, Anton; Albu, Madalina Georgiana; Birsan, Mihaela; Sonmez, Maria; Ficai, Denisa; Trandafir, Viorica; Andronescu, Ecaterina

    2013-04-01

    The aim of this study was to study the influence of collagen hydrolysate (HAS) on the formation of ternary collagen-hydrolysate/hydroxyapatite composite materials (COLL-HAS/HA). During the precipitation process of HA, a large amount of brushite is resulted at pH = 7 but, practically pure HA is obtained at pH ⩾ 8. The FTIR data reveal the duplication of the most important collagen absorption bands due to the presence of the collagen hydrolysate. The presence of collagen hydrolysate is beneficial for the management of bone and joint disorders such as osteoarthritis and osteoporosis.

  2. Titania nanotube arrays: Interfaces for implantable devices

    NASA Astrophysics Data System (ADS)

    Smith, Barbara Symie

    For the 8--10% of Americans (20--25 million people) that have implanted biomedical devices, biomaterial failure and the need for revision surgery are critical concerns. The major causes for failure in implantable biomedical devices promoting a need for re-implantation and revision surgery include thrombosis, post-operative infection, immune driven fibrosis and biomechanical failure. The successful integration of long-term implantable devices is highly dependent on the early events of tissue/biomaterial interaction, promoting either implant rejection or a wound healing response (extracellular matrix production and vasculature). Favorable interactions between the implant surface and the respective tissue are critical for the long-term success of any implantable device. Recent studies have shown that material surfaces which mimic the natural physiological hierarchy of in vivo tissue may provide a possible solution for enhancing biomaterial integration, thus preventing infection and biomaterial rejection. Titania nanotube arrays, fabricated using a simple anodization technique, provide a template capable of promoting altered cellular functionality at a hierarchy similar to that of natural tissue. This work focuses on the fabrication of immobilized, vertically oriented and highly uniform titania nanotube arrays to determine how this specific nano-architecture affects skin cell functionality, hemocompatibility, thrombogenicity and the immune response. The results in this work identify enhanced dermal matrix production, altered hemocompatibility, reduced thrombogenicity and a deterred immune response on titania nanotube arrays. This evidences promising implications with respect to the use of titania nanotube arrays as beneficial interfaces for the successful implantation of biomedical devices.

  3. [Hearing implants].

    PubMed

    Stokroos, Robert J; George, Erwin L J

    2013-01-01

    In the Netherlands, more than 1.5 million people suffer from sensorineural hearing loss or deafness. However, fitting conventional hearing aids does not provide a solution for everyone. In recent decades, developments in medical technology have produced implantable and other devices that restore both sensorineural and conductive hearing losses. These hearing devices can be categorized into bone conductive devices, implantable middle ear prostheses, cochlear implants and auditory brainstem implants. Furthermore, new implants aimed at treating tinnitus and loss of vestibular function have recently been developed.

  4. Human dermal stem/progenitor cell-derived conditioned medium ameliorates ultraviolet a-induced damage of normal human dermal fibroblasts.

    PubMed

    Shim, Joong Hyun; Park, Ju-Yearl; Lee, Mi-Gi; Kang, Hak Hee; Lee, Tae Ryong; Shin, Dong Wook

    2013-01-01

    Adult skin stem cells are considered an attractive cell resource for therapeutic potential in aged skin. We previously reported that multipotent human dermal stem/progenitor cells (hDSPCs) can be enriched from (normal human dermal fibroblasts (NHDFs) using collagen type IV. However, the beneficial effects of hDSPCs on aged skin remain to be elucidated. In the present study, we analyzed the growth factors secreted from hDSPCs in conditioned medium (CM) derived from hDSPCs (hDSPC-CM) and found that hDSPCs secreted higher levels of bFGF, IGFBP-1, IGFBP-2, HGF, VEGF and IGF-1 compared with non-hDSPCs. We then investigated whether hDSPC-CM has an effect on ultraviolet A (UVA)-irradiated NHDFs. Real-time RT-PCR analysis revealed that the treatment of UVA-irradiated NHDFs with hDSPC-CM significantly antagonized the UVA-induced up-regulation of the MMP1 and the UVA-induced down-regulation of the collagen types I, IV and V and TIMP1 mRNA expressions. Furthermore, a scratch wound healing assay showed that hDSPC-CM enhanced the migratory properties of UVA-irradiated NHDFs. hDSPC-CM also significantly reduced the number of the early and late apoptotic cell population in UVA-irradiated NHDFs. Taken together, these data suggest that hDSPC-CM can exert some beneficial effects on aged skin and may be used as a therapeutic agent to improve skin regeneration and wound healing.

  5. Topographic mapping of collagenous gastritis.

    PubMed

    Freeman, H J

    2001-07-01

    A 74-year-old woman was investigated for abdominal pain and diarrhea. Endoscopic examinations including biopsies of the stomach and colon demonstrated the typical subepithelial deposits characteristic of collagenous gastritis and collagenous colitis. Histochemical and ultrastructural methods confirmed the presence of collagen in the subepithelial deposits. The topographic distribution of these collagen deposits and their relationship to the inflammatory process in the stomach were then defined by endoscopic mapping and multiple site biopsies of the mucosa in the gastric body and antrum. These studies indicate that collagenous gastritis not only is distinctive, but also is a far more extensive and diffuse inflammatory process than has previously been appreciated. PMID:11493952

  6. Electrospun polyvinyl alcohol-collagen-hydroxyapatite nanofibers: a biomimetic extracellular matrix for osteoblastic cells

    NASA Astrophysics Data System (ADS)

    Song, Wei; Markel, David C.; Wang, Sunxi; Shi, Tong; Mao, Guangzhao; Ren, Weiping

    2012-03-01

    The failure of prosthesis after total joint replacement is due to the lack of early implant osseointegration. In this study polyvinyl alcohol-collagen-hydroxyapatite (PVA-Col-HA) electrospun nanofibrous meshes were fabricated as a biomimetic bone-like extracellular matrix for the modification of orthopedic prosthetic surfaces. In order to reinforce the PVA nanofibers, HA nanorods and Type I collagen were incorporated into the nanofibers. We investigated the morphology, biodegradability, mechanical properties and biocompatibility of the prepared nanofibers. Our results showed these inorganic-organic blended nanofibers to be degradable in vitro. The encapsulated nano-HA and collagen interacted with the PVA content, reinforcing the hydrolytic resistance and mechanical properties of nanofibers that provided longer lasting stability. The encapsulated nano-HA and collagen also enhanced the adhesion and proliferation of murine bone cells (MC3T3) in vitro. We propose the PVA-Col-HA nanofibers might be promising modifying materials on implant surfaces for orthopedic applications.

  7. Epoxy Cross-Linked Collagen and Collagen-Laminin Peptide Hydrogels as Corneal Substitutes

    PubMed Central

    Koh, Li Buay; Islam, Mohammad Mirazul; Mitra, Debbie; Noel, Christopher W.; Merrett, Kimberley; Odorcic, Silvia; Fagerholm, Per; Jackson, William. Bruce; Liedberg, Bo; Phopase, Jaywant; Griffith, May

    2013-01-01

    A bi-functional epoxy-based cross-linker, 1,4-Butanediol diglycidyl ether (BDDGE), was investigated in the fabrication of collagen based corneal substitutes. Two synthetic strategies were explored in the preparation of the cross-linked collagen scaffolds. The lysine residues of Type 1 porcine collagen were directly cross-linked using l,4-Butanediol diglycidyl ether (BDDGE) under basic conditions at pH 11. Alternatively, under conventional methodology, using both BDDGE and 1-Ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) as cross-linkers, hydrogels were fabricated under acidic conditions. In this latter strategy, Cu(BF4)2·XH2O was used to catalyze the formation of secondary amine bonds. To date, we have demonstrated that both methods of chemical cross-linking improved the elasticity and tensile strength of the collagen implants. Differential scanning calorimetry and biocompatibility studies indicate comparable, and in some cases, enhanced properties compared to that of the EDC/NHS controls. In vitro studies showed that human corneal epithelial cells and neuronal progenitor cell lines proliferated on these hydrogels. In addition, improvement of cell proliferation on the surfaces of the materials was observed when neurite promoting laminin epitope, IKVAV, and adhesion peptide, YIGSR, were incorporated. However, the elasticity decreased with peptide incorporation and will require further optimization. Nevertheless, we have shown that epoxy cross-linkers should be further explored in the fabrication of collagen-based hydrogels, as alternatives to or in conjunction with carbodiimide cross-linkers. PMID:24956085

  8. Esthetic soft tissue ridge augmentation around dental implant: Case report

    PubMed Central

    Al-Hamdan, Khalid S.

    2011-01-01

    The aim of this case report is to present a method to correct soft tissue ridge deformity around dental implant using acellular dermal matrix (ADM). A 25-year-old female patient presented with a missing maxillary first left premolar, which had class I soft tissue defect. The missing tooth was replaced with single implant supported prosthesis and the soft tissue defect was corrected using ADM utilizing the envelop technique. A 5-years follow-up is presented showing the long-term stability of this technique and the predictability of using the ADM as an alternative method to connective tissue graft to correct the soft tissue defect around dental implant. PMID:23960518

  9. Early tissue reaction to textured breast implant surfaces.

    PubMed

    Brohim, R M; Foresman, P A; Hildebrandt, P K; Rodeheaver, G T

    1992-04-01

    Capsular contracture around breast implants with smooth surfaces continues to be an unpredictable complication. Some surgeons believe that silicone implants covered with porous polyurethane foam have a lowered potential to contract. These textured implants are not as biocompatible as silicone. Recently, silicone implants with textured surfaces have been introduced with the hope that the incidence of unacceptable implant contracture will be reduced. Using a rat implant model, the tissue reaction to textured implant surfaces was assessed. The implant surfaces evaluated were Silastic II, Siltex, MISTI, Biocell, Silastic MSI, and Même. Disks of each implant material were implanted under the dorsal skin of rats for a period of 28 days. Each implant with its surrounding tissue was excised, processed for histological analysis, and assessed for the tissue's response to the implant with particular emphasis on the formation of a continuous collagen capsule. The results indicated that the magnitude of surface texturing influenced the development of a complete capsule. Implant surfaces with a texture of less than 150 microns in height or depth (Silastic II, Siltex, and MISTI) resulted in the formation of complete capsules. An implant (Biocell) with irregular texturing (200-350 microns) produced an organized capsule over most of its surface with localized interruptions of the capsule at the sites of its deepest cavities. Implant surfaces with texturing that exceeded 350 microns in height or depth (Silastic MSI and Même) resulted in inhibition of the formation of a continuous capsule during this 28-day study.

  10. Stabilized Collagen Scaffolds for Heart Valve Tissue Engineering

    PubMed Central

    Tedder, Mary E.; Liao, Jun; Weed, Benjamin; Stabler, Christopher; Zhang, Henry; Simionescu, Agneta

    2009-01-01

    Scaffolds for heart valve tissue engineering must function immediately after implantation but also need to tolerate cell infiltration and gradual remodeling. We hypothesized that moderately cross-linked collagen scaffolds would fulfill these requirements. To test our hypothesis, scaffolds prepared from decellularized porcine pericardium were treated with penta-galloyl glucose (PGG), a collagen-binding polyphenol, and tested for biodegradation, biaxial mechanical properties, and in vivo biocompatibility. For controls, we used un-cross-linked scaffolds and glutaraldehyde-treated scaffolds. Results confirmed complete pericardium decellularization and the ability of scaffolds to encourage fibroblast chemotaxis and to aid in creation of anatomically correct valve-shaped constructs. Glutaraldehyde cross-linking fully stabilized collagen but did not allow for tissue remodeling and calcified when implanted subdermally in rats. PGG-treated collagen was initially resistant to collagenase and then degraded gradually, indicating partial stabilization. Moreover, PGG-treated pericardium exhibited excellent biaxial mechanical properties, did not calcify in vivo, and supported infiltration by host fibroblasts and subsequent matrix remodeling. In conclusion, PGG-treated acellular pericardium is a promising scaffold for heart valve tissue engineering. PMID:18928400

  11. Stabilized collagen scaffolds for heart valve tissue engineering.

    PubMed

    Tedder, Mary E; Liao, Jun; Weed, Benjamin; Stabler, Christopher; Zhang, Henry; Simionescu, Agneta; Simionescu, Dan T

    2009-06-01

    Scaffolds for heart valve tissue engineering must function immediately after implantation but also need to tolerate cell infiltration and gradual remodeling. We hypothesized that moderately cross-linked collagen scaffolds would fulfill these requirements. To test our hypothesis, scaffolds prepared from decellularized porcine pericardium were treated with penta-galloyl glucose (PGG), a collagen-binding polyphenol, and tested for biodegradation, biaxial mechanical properties, and in vivo biocompatibility. For controls, we used un-cross-linked scaffolds and glutaraldehyde-treated scaffolds. Results confirmed complete pericardium decellularization and the ability of scaffolds to encourage fibroblast chemotaxis and to aid in creation of anatomically correct valve-shaped constructs. Glutaraldehyde cross-linking fully stabilized collagen but did not allow for tissue remodeling and calcified when implanted subdermally in rats. PGG-treated collagen was initially resistant to collagenase and then degraded gradually, indicating partial stabilization. Moreover, PGG-treated pericardium exhibited excellent biaxial mechanical properties, did not calcify in vivo, and supported infiltration by host fibroblasts and subsequent matrix remodeling. In conclusion, PGG-treated acellular pericardium is a promising scaffold for heart valve tissue engineering. PMID:18928400

  12. Regenerative therapy of deep peri-implant infrabony defects after CO2 laser implant surface decontamination.

    PubMed

    Romanos, Georgios E; Nentwig, Georg H

    2008-06-01

    The treatment of a peri-implant infrabony defect is difficult because of contamination of the implant surface and adjacent tissues. This case series addresses the ability of a carbon dioxide (CO2) laser to decontaminate failing implants in 15 patients. Clinical and radiologic data are presented with regard to using the laser in combination with bone grafting and a barrier. Augmentation with autogenous bone grafting material (n = 10) or a xenogenic bone grafting material (BioOss) (n = 9) was used, and bone grafts were covered with a collagen membrane. Clinical and radiologic parameters were evaluated postoperatively. After an observation period of 27 months (+/- 17.83), almost complete bone fill in the peri-implant defect was accomplished. These preliminary clinical and radiologic findings suggest that decontamination of the implant surfaces with the CO2 laser in combination with augmentative techniques can be an effective treatment method for peri-implantitis.

  13. Controlled release of an extract of Calendula officinalis flowers from a system based on the incorporation of gelatin-collagen microparticles into collagen I scaffolds: design and in vitro performance.

    PubMed

    Jiménez, Ronald A; Millán, Diana; Suesca, Edward; Sosnik, Alejandro; Fontanilla, Marta R

    2015-06-01

    Aiming to develop biological skin dresses with improved performance in the treatment of skin wounds, acellular collagen I scaffolds were modified with polymeric microparticles and the subsequent loading of a hydroglycolic extract of Calendula officinalis flowers. Microparticles made of gelatin-collagen were produced by a water-in-oil emulsion/cross-linking method. Thereafter, these microparticles were mixed with collagen suspensions at three increasing concentrations and the resulting mixtures lyophilized to make microparticle-loaded porous collagen scaffolds. Resistance to enzymatic degradation, ability to associate with the C. officinalis extract, and the extract release profile of the three gelatin-collagen microparticle-scaffold prototypes were assessed in vitro and compared to collagen scaffolds without microparticles used as control. Data indicated that the incorporation of gelatin-collagen microparticles increased the resistance of the scaffolds to in vitro enzymatic degradation, as well as their association with the C. officinalis flower extract. In addition, a sharp decrease in cytotoxicity, as well as more prolonged release of the extract, was attained. Overall results support the potential of these systems to develop innovative dermal substitutes with improved features. Furthermore, the gelatin-collagen mixture represents a low-cost and scalable alternative with high clinical transferability, especially appealing in developing countries. PMID:25787728

  14. Controlled release of an extract of Calendula officinalis flowers from a system based on the incorporation of gelatin-collagen microparticles into collagen I scaffolds: design and in vitro performance.

    PubMed

    Jiménez, Ronald A; Millán, Diana; Suesca, Edward; Sosnik, Alejandro; Fontanilla, Marta R

    2015-06-01

    Aiming to develop biological skin dresses with improved performance in the treatment of skin wounds, acellular collagen I scaffolds were modified with polymeric microparticles and the subsequent loading of a hydroglycolic extract of Calendula officinalis flowers. Microparticles made of gelatin-collagen were produced by a water-in-oil emulsion/cross-linking method. Thereafter, these microparticles were mixed with collagen suspensions at three increasing concentrations and the resulting mixtures lyophilized to make microparticle-loaded porous collagen scaffolds. Resistance to enzymatic degradation, ability to associate with the C. officinalis extract, and the extract release profile of the three gelatin-collagen microparticle-scaffold prototypes were assessed in vitro and compared to collagen scaffolds without microparticles used as control. Data indicated that the incorporation of gelatin-collagen microparticles increased the resistance of the scaffolds to in vitro enzymatic degradation, as well as their association with the C. officinalis flower extract. In addition, a sharp decrease in cytotoxicity, as well as more prolonged release of the extract, was attained. Overall results support the potential of these systems to develop innovative dermal substitutes with improved features. Furthermore, the gelatin-collagen mixture represents a low-cost and scalable alternative with high clinical transferability, especially appealing in developing countries.

  15. Collagen Homeostasis and Metabolism.

    PubMed

    Magnusson, S Peter; Heinemeier, Katja M; Kjaer, Michael

    2016-01-01

    The musculoskeletal system and its collagen rich tissue is important for ensuring architecture of skeletal muscle, energy storage in tendon and ligaments, joint surface protection, and for ensuring the transfer of muscular forces into resulting limb movement. Structure of tendon is stable and the metabolic activity is low, but mechanical loading and subsequent mechanotransduction and molecular anabolic signaling can result in some adaptation of the tendon especially during youth and adolescence. Within short time, tendon will get stiffer with training and lack of mechanical tissue loading through inactivity or immobilization of the human body will conversely result in a dramatic loss in tendon stiffness and collagen synthesis. This illustrates the importance of regular mechanical load in order to preserve the stabilizing role of the connective tissue for the overall function of the musculoskeletal system in both daily activity and exercise. Adaptive responses may vary along the tendon, and differ between mid-substance and insertional areas of the tendon. PMID:27535245

  16. Optical coherence tomography: imaging architect for dermal microdialysis in psoriasis

    NASA Astrophysics Data System (ADS)

    O'Connell, M.-L.; O'Connor, W.; Ramsay, B.; Guihen, E.; Ho, W. L.; Leahy, M. J.

    2011-03-01

    Optical coherence tomography (OCT) has been used as part of a ground breaking translational study to shed some light on one of the worlds most prevalent autoimmune diseases; psoriasis. The work successfully integrates the fields of optical imaging, biochemistry and dermatology in conducting a dermal microdialysis (DMD) trial for quantitative histamine assessment amongst a group of psoriasis sufferers. The DMD process involves temporary insertion of microscopic hollow tubes into a layer of skin to measure the levels of histamine and other important biological molecules in psoriasis. For comparison purposes, DMD catheters were implanted into healthy, peri-lesional and lesional skin regions. The catheters' entry and exit points and their precise locations in the epidermal layer of the skin were confirmed using OCT thus obtaining high resolution, wide-field images of the affected skin as well as catheter placement whilst local microdialysis enabled a tissue chemistry profile to be obtained from these three skin regions including histamine, a local immune system activator known to contribute towards itch and inflammation. Together these tools offer a synergistic approach in the clinical assessment of the disease. In addition, OCT delivered a non-invasive and rapid method for analyzing the affected skin architecture.

  17. A method for measuring dermal exposure to solvents and fumigants

    SciTech Connect

    Cohen, B.S.M.

    1988-01-01

    This study aimed to develop a method for evaluating dermal exposure to deposits of volatile liquids. Telone II, a fumigant containing 1,3-dichloropropene (DCP), was used as an example. The approach included direct monitoring of dermal deposits and estimating the dermal absorbed dose. Charcoal cloth dermal dosimeters were developed for retaining the volatile deposits. Estimates are given for the retention efficiencies to be expected in various field conditions. The dermally absorbed dose is affected by the evaporation rate from the skin and by the percutaneous absorption rate (flux). Both factors were studied by the dermal dosing of ras with Telone, and monitoring evaporation and urine metabolites of cis-DCP. While relatively high flux values were calculated for rat and estimated for man, due to fast evaporation, the estimated absorbed fraction from a localized dermal deposit was less than 0.2%. Charcoal cloth dermal dosimeters and charcoal tubes were used in ten studies to monitor dermal and respiratory exposure of field applicators to Telone. The charcoal cloth dosimeter method is applicable for monitoring dermal exposure to other volatile chemicals also. However, evaluation of the exposure could be associated with relatively large variability, rendering the method semiquantitative.

  18. Collagen fibril aggregation-inhibitor from sea cucumber dermis.

    PubMed

    Trotter, J A; Lyons-Levy, G; Chino, K; Koob, T J; Keene, D R; Atkinson, M A

    1999-12-01

    Collagen fibrils from the dermis of the sea cucumber Cucumaria frondosa are aggregated in vitro by the dermal glycoprotein stiparin (Trotter et al., 1996). Under physiological ionic conditions stiparin appears to be both necessary and sufficient to cause fibrils to aggregate (Trotter et al., 1997). We report here the initial biochemical and biophysical characterization of a sulfated glycoprotein from C. frondosa dermis that binds stiparin and inhibits its fibril-aggregating activity. This inhibitory glycoprotein, which has been named 'stiparin-inhibitor,' has the highest negative charge density of all the macromolecules extracted from the dermis. SDS-PAGE reveals three approximately 31-kDa bands that stain with alcian blue but not with Coomassie blue. Analytical ultracentrifugation indicates a native molecular weight of 62 kDa. Transmission electron microscopy of rotary-shadowed molecules shows curved rods about 22 nm long. The glycoprotein does not bind collagen fibrils, but does bind stiparin with a 1:1 stoichiometry. The binding of stiparin-inhibitor to stiparin prevents the binding of stiparin to collagen fibrils. The carbohydrate moiety produced by papain-digestion of the glycoprotein retains all of its inhibitory activity. The carbohydrate moiety of the inhibitor is dominated by galactose and sulfate.

  19. Label-free nonenzymatic glycation monitoring of collagen scaffolds in type 2 diabetic mice by confocal Raman microspectroscopy

    NASA Astrophysics Data System (ADS)

    Shi, Panpan; Liu, Hanping; Deng, Xiaoyuan; Jin, Ying; Wang, Qiannan; Liu, Hao; Chen, Maosheng; Han, Xue

    2015-02-01

    Collagen is the key target of nonenzymatic glycation during physiopathological processes such as diabetes. The induced changes in the biochemical property of collagen by nonenzymatic glycation remain a major challenge to probe. This study investigated the use of confocal Raman microspectroscopy to label-free monitor the nonenzymatic glycation of collagen scaffolds from type 2 diabetic (T2D) mice at different timepoints (0, 4, 8, and 12 weeks). The glycated collagen scaffolds were obtained through the decellularized dermal matrix method to remove the epidermis layer, subcutaneous tissue, and cells in the dermis and to retain the collagen fibrils. Raman spectra showed no changes in Raman peak positions, which indicated that nonenzymatic glycation could produce no significant changes in the triple-helix structure of collagen in T2D mice. However, the relative intensity of the Raman bands at 921, 1033, 1244, 1274, 1346, 1635, and 1672 cm-1 increased as diabetic time progressed. Correlation analysis suggested that the spectra of these bands had a high positive correlation with the expression of anti-advanced glycation end products obtained by immunofluorescence imaging of the same collagen scaffolds. Confocal Raman microspectroscopy proves a potential tool to label-free monitor the collagen changes caused by nonenzymatic glycation in T2D mice.

  20. Characterization and mechanisms of photoageing-related changes in skin. Damages of basement membrane and dermal structures.

    PubMed

    Amano, Satoshi

    2016-08-01

    Sun-exposed skin is characterized by superficial changes such as wrinkles, sagging and pigmentary changes, and also many internal changes in the structure and function of epidermis, basement membrane (BM) and dermis. These changes (so-called photoageing) are predominantly induced by the ultraviolet (UV) component of sunlight. Epidermis of UV-irradiated skin produced several enzymes such as matrix metalloproteinases (MMPs), urinary plasminogen activator (uPA)/plasmin and heparanase, which degrade dermal collagen fibres and elastic fibres in the dermis, and components of epidermal BM. The BM at the dermal-epidermal junction (DEJ) controls dermal-epidermal signalling and plays an important role in the maintenance of a healthy epidermis and dermis. BM is repetitively damaged in sun-exposed skin compared with unexposed skin, leading to epidermal and dermal deterioration and accelerated skin ageing. UV exposure also induces an increase in vascular endothelial growth factor (VEGF), an angiogenic factor, while thrombospondin-1 (TSP-1), an anti-angiogenic factor, is decreased; these changes induce angiogenesis in papillary dermis with increased migration of elastase-positive leucocytes, leading to dermal elastic fibre damage. Elastic fibres, such as oxytalan fibres in papillary dermis, are associated with not only skin resilience, but also skin surface texture, and elastic fibre formation by fibroblasts is facilitated by increased expression of fibulin-5. Thus, induction of fibulin-5 expression is a damage-repair mechanism, and fibulin-5 is an early marker of photoaged skin. UV-induced skin damage is cumulative and leads to premature ageing of skin. However, appropriate daily skincare may ameliorate photoageing by inhibiting processes causing damage and enhancing repair processes. PMID:27539897

  1. Ovine tendon collagen: Extraction, characterisation and fabrication of thin films for tissue engineering applications.

    PubMed

    Fauzi, M B; Lokanathan, Y; Aminuddin, B S; Ruszymah, B H I; Chowdhury, S R

    2016-11-01

    Collagen is the most abundant extracellular matrix (ECM) protein in the human body, thus widely used in tissue engineering and subsequent clinical applications. This study aimed to extract collagen from ovine (Ovis aries) Achilles tendon (OTC), and to evaluate its physicochemical properties and its potential to fabricate thin film with collagen fibrils in a random or aligned orientation. Acid-solubilized protein was extracted from ovine Achilles tendon using 0.35M acetic acid, and 80% of extracted protein was measured as collagen. SDS-PAGE and mass spectrometry analysis revealed the presence of alpha 1 and alpha 2 chain of collagen type I (col I). Further analysis with Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) confirms the presence of triple helix structure of col I, similar to commercially available rat tail col I. Drying the OTC solution at 37°C resulted in formation of a thin film with randomly orientated collagen fibrils (random collagen film; RCF). Introduction of unidirectional mechanical intervention using a platform rocker prior to drying facilitated the fabrication of a film with aligned orientation of collagen fibril (aligned collagen film; ACF). It was shown that both RCF and ACF significantly enhanced human dermal fibroblast (HDF) attachment and proliferation than that on plastic surface. Moreover, cells were distributed randomly on RCF, but aligned with the direction of mechanical intervention on ACF. In conclusion, ovine tendon could be an alternative source of col I to fabricate scaffold for tissue engineering applications. PMID:27524008

  2. Ovine tendon collagen: Extraction, characterisation and fabrication of thin films for tissue engineering applications.

    PubMed

    Fauzi, M B; Lokanathan, Y; Aminuddin, B S; Ruszymah, B H I; Chowdhury, S R

    2016-11-01

    Collagen is the most abundant extracellular matrix (ECM) protein in the human body, thus widely used in tissue engineering and subsequent clinical applications. This study aimed to extract collagen from ovine (Ovis aries) Achilles tendon (OTC), and to evaluate its physicochemical properties and its potential to fabricate thin film with collagen fibrils in a random or aligned orientation. Acid-solubilized protein was extracted from ovine Achilles tendon using 0.35M acetic acid, and 80% of extracted protein was measured as collagen. SDS-PAGE and mass spectrometry analysis revealed the presence of alpha 1 and alpha 2 chain of collagen type I (col I). Further analysis with Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) confirms the presence of triple helix structure of col I, similar to commercially available rat tail col I. Drying the OTC solution at 37°C resulted in formation of a thin film with randomly orientated collagen fibrils (random collagen film; RCF). Introduction of unidirectional mechanical intervention using a platform rocker prior to drying facilitated the fabrication of a film with aligned orientation of collagen fibril (aligned collagen film; ACF). It was shown that both RCF and ACF significantly enhanced human dermal fibroblast (HDF) attachment and proliferation than that on plastic surface. Moreover, cells were distributed randomly on RCF, but aligned with the direction of mechanical intervention on ACF. In conclusion, ovine tendon could be an alternative source of col I to fabricate scaffold for tissue engineering applications.

  3. Collagen incorporation within electrospun conduits reduces lipid oxidation and impacts conduit mechanics.

    PubMed

    Birthare, Karamveer; Shojaee, Mozhgan; Jones, Carlos Gross; Brenner, James R; Bashur, Chris A

    2016-04-01

    Modulating the host response, including the accumulation of oxidized lipid species, is important for improving tissue engineered vascular graft (TEVG) viability. Accumulation of oxidized lipids promotes smooth muscle cell (SMC) hyper-proliferation and inhibits endothelial cell migration, which can lead to several of the current challenges for small-diameter TEVGs. Generating biomaterials that reduce lipid oxidation is important for graft survival and this assessment can provide a reliable correlation to clinical situations. In this study, we determined the collagen to poly(ε-caprolactone) (PCL) ratio required to limit the production of pro-inflammatory species, while maintaining the required mechanical strength for the graft. Electrospun conduits were prepared from 0%, 10%, and 25% blends of collagen/PCL (w/w) and implanted in the rat peritoneal cavity for four weeks. The results showed that adding collagen to the PCL conduits reduced the accumulation of oxidized lipid species within the implanted conduits. In addition, the ratio of collagen had a significant impact on the recruited cell phenotype and construct mechanics. All conduits exhibited greater than 44% yield strain and sufficient tensile strength post-implantation. In conclusion, these results demonstrate that incorporating collagen into synthetic electrospun scaffolds, both 10% and 25% blend conditions, appears to limit the pro-inflammatory characteristics after in vivo implantation. PMID:27099237

  4. Implantable Microimagers

    PubMed Central

    Ng, David C.; Tokuda, Takashi; Shiosaka, Sadao; Tano, Yasuo; Ohta, Jun

    2008-01-01

    Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications.

  5. Serpin A1 C-Terminal Peptides as Collagen Turnover Modulators.

    PubMed

    Pascarella, Simona; Tiberi, Caterina; Sabatino, Giuseppina; Nuti, Francesca; Papini, Anna Maria; Giovannelli, Lisa; Rovero, Paolo

    2016-08-19

    The modulation of collagen turnover can be a relevant pharmacological target in the context of treating either pathological or pathophysiological conditions, such as collagen-related diseases and skin aging. Our recent work has focused on the search for short-chain peptides as lead compounds for further development of compounds that enhance the production of type I collagen. In this study we selected and synthesized overlapping peptides of the C-terminal portion of serpin A1 (residues 393-418), the impact of which on collagen production has been reported previously, in order to identify shorter and still active fragments and to provide insight on the mechanisms involved. The biological activity of each fragment was evaluated with cultured normal human dermal fibroblasts, and changes in the amounts of collagen were monitored in collected culture media by a sandwich ELISA technique developed in house. Interestingly, we identified a decapeptide, termed SA1-III (Ac-MGKVVNPTQK-NH2 ), as a promising candidate for our purposes; it is able to induce a significant increase in type I collagen levels in the culture medium of treated cells at micromolar concentrations. PMID:26615979

  6. Dermal mass aspirate from a Persian cat.

    PubMed

    Zimmerman, Kurt; Feldman, Bernard; Robertson, John; Herring, Erin S; Manning, Thomas

    2003-01-01

    A 1-year-old spayed female Persian cat with alopecia and weight loss had numerous variably ulcerated dermal nodules. Cytologic examination of an aspirate of one of the nodules revealed pyogranulomatous inflammation along with septate hyphae and basophilic round bodies, 0.5-1.0 microm in diameter, surrounded by a thin clear halo (arthrospores). The cytologic diagnosis was dermatophytic pseudomycetoma. Histologically, there were dermal granulomas containing poorly staining, septate hyphae with bulbous spores embedded within abundant amorphous eosinophilic material (Splendore-Hoeppli reaction), and the histologic diagnosis was pseudomycetoma-associated chronic multifocal severe granulomatous dermatitis with lymphocytic perifolliculitis and furunculosis. Microsporum canis was cultured from the lesion. Pseudomycetomas are distinguished from fungal mycetomas, or eumycotic mycetomas, by the findings of multiple lesions, lack of a history of skin trauma, an association with dermatophytes, most commonly Microsporum canis, and, histologically, lack of true cement material and a more abundant Splendore-Hoeppli reaction in pseudomycetomas. Additionally, pseudomycetomas differ from dermatophytosis, in which lesions are restricted to epidermal structures. Persian cats have a high incidence of pseudomycetoma formation, suggesting a heritable predisposition. The prognosis is fair with systemic antifungal therapy. When examining cytologic specimens from Persian cats with single or multiple dermal nodules, especially if pyogranulomatous inflammation is present, a diagnosis of pseudomycetoma should be suspected and is warranted if arthrospores and refractile septate hyphae are present.

  7. Conceptual model for assessment of dermal exposure

    PubMed Central

    Schneider, T.; Vermeulen, R.; Brouwer, D. H.; Cherrie, J. W.; Kromhout, H.; Fogh, C. L.

    1999-01-01

    Dermal exposure, primarily to pesticides, has been measured for almost half a century. Compared with exposure by inhalation, limited progress has been made towards standardisation of methods of measurement and development of biologically relevant exposure measures. It is suggested that the absence of a consistent terminology and a theoretical model has been an important cause of this lack of progress. Therefore, a consistent terminology based on a multicompartment model for assessment of dermal exposure is proposed that describes the transport of contaminant mass from the source of the hazardous substance to the surface of the skin. Six compartments and two barriers together with eight mass transport processes are described. With the model structure, examples are given of what some existing methods actually measure and where there are limited, or no, methods for measuring the relevant mass in a compartment or transport of mass. The importance of measuring the concentration of contaminant and not mass per area in the skin contaminant layer is stressed, as it is the concentration difference between the skin contamination layer and the perfused tissue that drives uptake. Methods for measuring uptake are currently not available. Measurement of mass, concentration, and the transport processes must be based on a theoretical model. Standardisation of methods of measurement of dermal exposure is strongly recommended.   PMID:10658563

  8. Release and retention of biomolecules in collagen deposited on orthopedic biomaterials.

    PubMed

    Puleo, D A

    1999-01-01

    Delivery of osteotropic biomolecules directly to the bone-implant interface can alter initial interactions between tissue and biomaterial. To this end, type I collagen coatings containing a model biomolecule, lysozyme, were deposited on Co-Cr-Mo and Ti-6Al-4V. Two deposition methods were examined. In the first, lysozyme was deposited concurrently with collagen, while in the second, protein was impregnated into previously deposited collagen coatings. The amount of collagen and the amount of lysozyme loaded into collagen were varied to provide different amounts of weakly and strongly bound protein. Release and retention of lysozyme were monitored over a 7 d period of incubation in physiological saline. For both methods, larger amounts of collagen in the coatings allowed incorporation of more lysozyme. Additionally, loading collagen coatings with greater amounts of lysozyme resulted in release of more protein. During the first 24-96 h of incubation, loosely bound protein was eluted, resulting in release of 2 micrograms to 55 mg (5-75% of the amount available) of enzymatically active lysozyme. This left 25-95% of the protein bound to the collagen-coated biomaterials and, thus, available for later release during degradation of the collagen. PMID:10063439

  9. Effect of modifications of dual acid-etched implant surfaces on periimplant bone formation. Part II: calcium phosphate coatings.

    PubMed

    Schliephake, H; Aref, A; Scharnweber, D; Rösler, S; Sewing, A

    2009-01-01

    The aim of the present study was to test the hypothesis that calcium phosphate coatings of dual acid-etched surfaces (DAEs) can improve periimplant bone regeneration. Ten adult female foxhounds received experimental titanium screw implants in the mandible 3 months after removal of all premolar teeth. Five types of surface states were evaluated in each animal: (i) implants with a machined surface (MS) (Control 1); (ii) implants with a DAE (Control 2); (iii) implants with a DAE coated with collagen I (Control 3); (iv) implants with a DAE with mineralized collagen I; and (v) implants with a DAE with a hydroxylapatite (HA) coating. Periimplant bone regeneration was assessed by histomorphometry after 1 and 3 months in five dogs each by measuring bone implant contact (BIC) and the volume density of the newly formed periimplant bone (BVD). After 1 month, mean BIC of experimental implants did not differ significantly from implants with DAE and collagen-coated surfaces, but was significantly higher than the MS implants. BVD was enhanced significantly only in implants with mineralized collagen coating compared with DAE and collagen-coated controls. After 3 months, the mean values of BIC had increased significantly in the group of implants with HA and mineralized collagen coating but were not significantly different from implants with DAE and collagen-coated surfaces. The same held true for the mean BVD values. In conclusion, the present study could not verify the hypothesis that calcium phosphate coatings of DAEs in the present form enhanced periimplant bone formation compared with the DAE surface alone. PMID:19126106

  10. Investigation on the effect of collagen and vitamins on biomimetic hydroxyapatite coating formation on titanium surfaces.

    PubMed

    Ciobanu, Gabriela; Ciobanu, Octavian

    2013-04-01

    This study uses an in vitro experimental approach to investigate the roles of collagen and vitamins in regulating the deposition of hydroxyapatite layer on the pure titanium surface. Titanium implants were coated with a hydroxyapatite layer under biomimetic conditions by using a supersaturated calcification solution (SCS), modified by adding vitamins A and D3, and collagen. The hydroxyapatite deposits on titanium were investigated by means of scanning electron microscopy (SEM) coupled with X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results obtained have shown that hydroxyapatite coatings were produced in vitro under vitamins and collagen influence.

  11. Evaluation of electric arc furnace-processed steel slag for dermal corrosion, irritation, and sensitization from dermal contact.

    PubMed

    Suh, Mina; Troese, Matthew J; Hall, Debra A; Yasso, Blair; Yzenas, John J; Proctor, Debora M

    2014-12-01

    Electric arc furnace (EAF) steel slag is alkaline (pH of ~11-12) and contains metals, most notably chromium and nickel, and thus has potential to cause dermal irritation and sensitization at sufficient dose. Dermal contact with EAF slag occurs in many occupational and environmental settings because it is used widely in construction and other industrial sectors for various applications including asphaltic paving, road bases, construction fill, and as feed for cement kilns construction. However, no published study has characterized the potential for dermal effects associated with EAF slag. To assess dermal irritation, corrosion and sensitizing potential of EAF slag, in vitro and in vivo dermal toxicity assays were conducted based on the Organisation for Economic Co-operation and Development (OECD) guidelines. In vitro dermal corrosion and irritation testing (OECD 431 and 439) of EAF slag was conducted using the reconstructed human epidermal (RHE) tissue model. In vivo dermal toxicity and delayed contact sensitization testing (OECD 404 and 406) were conducted in rabbits and guinea pigs, respectively. EAF slag was not corrosive and not irritating in any tests. The results of the delayed contact dermal sensitization test indicate that EAF slag is not a dermal sensitizer. These findings are supported by the observation that metals in EAF slag occur as oxides of low solubility with leachates that are well below toxicity characteristic leaching procedure (TCLP) limits. Based on these results and in accordance to the OECD guidelines, EAF slag is not considered a dermal sensitizer, corrosive or irritant.

  12. Protective Effects of Triphala on Dermal Fibroblasts and Human Keratinocytes

    PubMed Central

    Varma, Sandeep R.; Sivaprakasam, Thiyagarajan O.; Mishra, Abheepsa; Kumar, L. M. Sharath; Prakash, N. S.; Prabhu, Sunil; Ramakrishnan, Shyam

    2016-01-01

    Human skin is body’s vital organ constantly exposed to abiotic oxidative stress. This can have deleterious effects on skin such as darkening, skin damage, and aging. Plant-derived products having skin-protective effects are well-known traditionally. Triphala, a formulation of three fruit products, is one of the most important rasayana drugs used in Ayurveda. Several skin care products based on Triphala are available that claim its protective effects on facial skin. However, the skin protective effects of Triphala extract (TE) and its mechanistic action on skin cells have not been elucidated in vitro. Gallic acid, ellagic acid, and chebulinic acid were deduced by LC-MS as the major constituents of TE. The identified key compounds were docked with skin-related proteins to predict their binding affinity. The IC50 values for TE on human dermal fibroblasts (HDF) and human keratinocytes (HaCaT) were 204.90 ± 7.6 and 239.13 ± 4.3 μg/mL respectively. The antioxidant capacity of TE was 481.33 ± 1.5 mM Trolox equivalents in HaCaT cells. Triphala extract inhibited hydrogen peroxide (H2O2) induced RBC haemolysis (IC50 64.95 μg/mL), nitric oxide production by 48.62 ± 2.2%, and showed high reducing power activity. TE also rescued HDF from H2O2-induced damage; inhibited H2O2 induced cellular senescence and protected HDF from DNA damage. TE increased collagen-I, involucrin and filaggrin synthesis by 70.72 ± 2.3%, 67.61 ± 2.1% and 51.91 ± 3.5% in HDF or HaCaT cells respectively. TE also exhibited anti-tyrosinase and melanin inhibition properties in a dose-dependent manner. TE increased the mRNA expression of collagen-I, elastin, superoxide dismutase (SOD-2), aquaporin-3 (AQP-3), filaggrin, involucrin, transglutaminase in HDF or HaCaT cells, and decreased the mRNA levels of tyrosinase in B16F10 cells. Thus, Triphala exhibits protective benefits on skin cells in vitro and can be used as a potential ingredient in skin care formulations. PMID:26731545

  13. Protective Effects of Triphala on Dermal Fibroblasts and Human Keratinocytes.

    PubMed

    Varma, Sandeep R; Sivaprakasam, Thiyagarajan O; Mishra, Abheepsa; Kumar, L M Sharath; Prakash, N S; Prabhu, Sunil; Ramakrishnan, Shyam

    2016-01-01

    Human skin is body's vital organ constantly exposed to abiotic oxidative stress. This can have deleterious effects on skin such as darkening, skin damage, and aging. Plant-derived products having skin-protective effects are well-known traditionally. Triphala, a formulation of three fruit products, is one of the most important rasayana drugs used in Ayurveda. Several skin care products based on Triphala are available that claim its protective effects on facial skin. However, the skin protective effects of Triphala extract (TE) and its mechanistic action on skin cells have not been elucidated in vitro. Gallic acid, ellagic acid, and chebulinic acid were deduced by LC-MS as the major constituents of TE. The identified key compounds were docked with skin-related proteins to predict their binding affinity. The IC50 values for TE on human dermal fibroblasts (HDF) and human keratinocytes (HaCaT) were 204.90 ± 7.6 and 239.13 ± 4.3 μg/mL respectively. The antioxidant capacity of TE was 481.33 ± 1.5 mM Trolox equivalents in HaCaT cells. Triphala extract inhibited hydrogen peroxide (H2O2) induced RBC haemolysis (IC50 64.95 μg/mL), nitric oxide production by 48.62 ± 2.2%, and showed high reducing power activity. TE also rescued HDF from H2O2-induced damage; inhibited H2O2 induced cellular senescence and protected HDF from DNA damage. TE increased collagen-I, involucrin and filaggrin synthesis by 70.72 ± 2.3%, 67.61 ± 2.1% and 51.91 ± 3.5% in HDF or HaCaT cells respectively. TE also exhibited anti-tyrosinase and melanin inhibition properties in a dose-dependent manner. TE increased the mRNA expression of collagen-I, elastin, superoxide dismutase (SOD-2), aquaporin-3 (AQP-3), filaggrin, involucrin, transglutaminase in HDF or HaCaT cells, and decreased the mRNA levels of tyrosinase in B16F10 cells. Thus, Triphala exhibits protective benefits on skin cells in vitro and can be used as a potential ingredient in skin care formulations. PMID:26731545

  14. IL-13 mediates collagen deposition via STAT6 and microRNA-135b: a role for epigenetics

    PubMed Central

    O’Reilly, Steven; Ciechomska, Marzena; Fullard, Nicola; Przyborski, Stefan; van Laar, Jacob M.

    2016-01-01

    Systemic sclerosis is an autoimmune connective tissue disease in which T cells play a prominent role. We and others have previously demonstrated a role for T cell-derived IL-13 in mediating the induction of collagen in dermal fibroblasts and that blockade with IL-13 antibodies attenuates this increase. In this study we want to probe the signalling that underpins IL-13 mediated matrix deposition. Isolated dermal fibroblasts were incubated with recombinant IL-13 and gene expression by qRT-PCR was performed for collagen1A1 and TGF-β1. Small interfering RNA (siRNA) was used to knock down STAT6 and a small molecule inhibitor was also used to block this pathway. MiR-135b was transfected into fibroblasts plus and minus IL-13 to see if this miR plays a role. miR-135b was measured in systemic sclerosis fibroblasts isolated from patients and also in serum. Results showed that IL-13 increased collagen expression and that this is independent from TGF-β1. This is dependent on STAT6 as targeting this blocked induction. MiR-135b reduces collagen induction in fibroblasts and scleroderma fibroblasts have lower constitutive levels of the miR. We further demonstrate that miR135b is repressed by methylation and may include MeCP2. In conclusion we show that STAT6 and miR-135b regulate IL-13-mediated collagen production by fibroblasts. PMID:27113293

  15. Heterogeneity of collagens in rabbit cornea: type III collagen

    SciTech Connect

    Cintron, C.; Hong, B.S.; Covington, H.I.; Macarak, E.J.

    1988-05-01

    Whole neonate rabbit corneas and adult corneas containing 2-week-old scars were incubated in the presence of (/sup 14/C) glycine. Radiolabeled collagen extracted from the corneas and scar tissue were analyzed by sodium dodecylsulfate/polyacrylamide gel electrophoresis and fluorography to determine the types and relative quantity of collagen polypeptides present and synthesized by these tissues. In addition to other collagen types, type III was found in both neonate cornea and scar tissue from adult cornea, albeit in relatively small quantities. Type III collagen in normal cornea was associated with the residue after pepsin digestion and formic acid extraction of the tissue, and the same type of collagen was extracted from scar tissue after similar treatment. Type III collagen-specific monoclonal antibody bound to developing normal corneas and healing adult tissue sections, as determined by immunofluorescence. Antibody binding was localized to the endothelium and growing Descemet's membrane in fetal and neonate corneas, and restricted to the most posterior region of the corneal scar tissue. Although monoclonal antibody to keratan sulfate, used as a marker for stromal fibroblasts, bound to most of the scar tissue, the antibody failed to bind to the posterior scar tissue positive for type III collagen. We conclude that endothelial cells from fetal and neonate rabbit cornea and endothelium-derived fibroblasts from healing wounds of adult cornea synthesize and deposit type III collagen. Moreover, this collagen appears to be incorporated into the growing Descemet's membrane of normal corneas and narrow posterior portion of the scar tissue.

  16. Collagen macromolecular drug delivery systems

    SciTech Connect

    Gilbert, D.L.

    1988-01-01

    The objective of this study was to examine collagen for use as a macromolecular drug delivery system by determining the mechanism of release through a matrix. Collagen membranes varying in porosity, crosslinking density, structure and crosslinker were fabricated. Collagen characterized by infrared spectroscopy and solution viscosity was determined to be pure and native. The collagen membranes were determined to possess native vs. non-native quaternary structure and porous vs. dense aggregate membranes by electron microscopy. Collagen monolithic devices containing a model macromolecule (inulin) were fabricated. In vitro release rates were found to be linear with respect to t{sup {1/2}} and were affected by crosslinking density, crosslinker and structure. The biodegradation of the collagen matrix was also examined. In vivo biocompatibility, degradation and {sup 14}C-inulin release rates were evaluated subcutaneously in rats.

  17. Rapid Fabrication of Living Tissue Models by Collagen Plastic Compression: Understanding Three-Dimensional Cell Matrix Repair In Vitro

    PubMed Central

    Cheema, Umber; Brown, Robert A.

    2013-01-01

    Objective To produce biomimetic collagen scaffolds for tissue modeling and as tissue-engineered implants. Approach Control of collagen fibril material parameters in collagen hydrogel scaffolds by using plastic compression (PC), resulting in direct control of cell proliferation, cell migration, and cell–cell interaction. Results We were able to control the density of collagen in such scaffolds from between 0.2% and 30%, and controllably layer the fibrils in the Z-plane. Cell migration was observed in gels where a gradient of collagen density was present. In these gels, cells preferentially migrated toward the collagen-dense areas. Cell proliferation rates were measurably higher in dense collagen gels. Innovation The use of PC to control material properties of collagen hydrogels results in collagen scaffolds that are biomimetic. These collagen gels reproduce the relevant matrix-mechanical environment in which behavior is more representative of that found in vivo. Conclusion The material properties of native collagen type I gels can be engineered to match those found in tissues in vivo to elicit more biomimetic cell behavior. PMID:24527341

  18. Self-setting collagen-calcium phosphate bone cement: mechanical and cellular properties.

    PubMed

    Moreau, Jennifer L; Weir, Michael D; Xu, Hockin H K

    2009-11-01

    Calcium phosphate cement (CPC) can conform to complex bone cavities and set in-situ to form bioresorbable hydroxyapatite. The aim of this study was to develop a CPC-collagen composite with improved fracture resistance, and to investigate the effects of collagen on mechanical and cellular properties. A type-I bovine-collagen was incorporated into CPC. MC3T3-E1 osteoblasts were cultured. At CPC powder/liquid mass ratio of 3, the work-of-fracture (mean +/- sd; n = 6) was increased from (22 +/- 4) J/m(2) at 0% collagen, to (381 +/- 119) J/m(2) at 5% collagen (p < or = 0.05). At 2.5-5% of collagen, the flexural strength at powder/liquid ratios of 3 and 3.5 was 8-10 MPa. They matched the previously reported 2-11 MPa of sintered porous hydroxyapatite implants. SEM revealed that the collagen fibers were covered with nano-apatite crystals and bonded to the CPC matrix. Higher collagen content increased the osteoblast cell attachment (p < or = 0.05). The number of live cells per specimen area was (382 +/- 99) cells/mm(2) on CPC containing 5% collagen, higher than (173 +/- 42) cells/mm(2) at 0% collagen (p < or = 0.05). The cytoplasmic extensions of the cells anchored to the nano-apatite crystals of the CPC matrix. In summary, collagen was incorporated into in situ-setting, nano-apatitic CPC, achieving a 10-fold increase in work-of-fracture (toughness) and two-fold increase in osteoblast cell attachment. This moldable/injectable, mechanically strong, nano-apatite-collagen composite may enhance bone regeneration in moderate stress-bearing applications.

  19. An apparatus for freeze-fracturing specimens of dermal collagen in preparation for scanning electron microscopy.

    PubMed

    Lamberty, B G; Ellis, C B

    1981-03-01

    A new apparatus is described which facilitates the freeze fracturing of specimens under liquid nitrogen in preparation for scanning electron microscopy. The apparatus is simple and can be made by any competent engineering department. PMID:7218351

  20. Facial granulomas secondary to Dermalive microimplants: Report of a case with histopathologic differential diagnosis among the granulomas secondary to different injectable permanent filler materials.

    PubMed

    Vargas-Machuca, Inmaculada; González-Guerra, Elena; Angulo, Jorge; del Carmen Fariña, María; Martín, Lucia; Requena, Luis

    2006-04-01

    Wrinkle reduction and the correction of skin defects using injectable aesthetic microimplants are now widely performed by dermatologists and plastic surgeons. In recent years, dermal filler substances containing polymer particle suspensions such as Bioplastique, Artecoll, and Dermalive are the most commonly used materials. These microimplants are permanent, non-biodegradable, and generally well tolerated, although various adverse reactions are still possible. We describe here a patient with facial granulomas secondary to Dermalive injections for correction of naso-labial folds and wrinkles. The particular shape of the injected particles allows for correct identification of the implanted material. Therefore, histopathologic examination is the best means to obtain the correct diagnosis of foreign body granuloma and to identify the type of filler particles. We discuss the histopathologic differential diagnosis among the granulomas secondary to the most commonly used aesthetic permanent filler materials.

  1. Type XIV Collagen Regulates Fibrillogenesis

    PubMed Central

    Ansorge, Heather L.; Meng, Xianmin; Zhang, Guiyun; Veit, Guido; Sun, Mei; Klement, John F.; Beason, David P.; Soslowsky, Louis J.; Koch, Manuel; Birk, David E.

    2009-01-01

    Type XIV collagen is a fibril-associated collagen with an interrupted triple helix. This collagen interacts with the fibril surface and has been implicated as a regulator of fibrillogenesis; however, a specific role has not been elucidated. Functional roles for type XIV collagen were defined utilizing a new type XIV collagen-deficient mouse line. This line was produced using a conventional targeted knock-out approach. Col14a1(–/–) mice were devoid of type XIV collagen, whereas heterozygous mice had reduced synthesis. Both mutant Col14a1 genotypes were viable with a grossly normal phenotype; however, mature skin exhibited altered mechanical properties. Prior to evaluating tendon fibrillogenesis in type XIV collagen-deficient mice, the developmental expression patterns were analyzed in wild-type flexor digitorum longus (FDL) tendons. Analyses of mRNA and protein expression indicated tissue-specific temporal expression that was associated with the early stages in fibrillogenesis. Ultrastructural analyses of wild-type and null tendons demonstrated premature fibril growth and larger fibril diameters in tendons from null mice at postnatal day 4 (P4). However, fibril structure in mature tendons was normal. Biomechanical studies established a direct structure/function relationship with reduced strength in P7-null tendons. However, the biomechanical properties in P60 tendons were comparable in null and wild-type mice. Our results indicate a regulatory function for type XIV collagen in early stages of collagen fibrillogenesis with tissue differences. PMID:19136672

  2. Arterial calcification: Conscripted by collagen

    NASA Astrophysics Data System (ADS)

    Miller, Jordan D.

    2016-03-01

    In atherosclerotic plaques, patterns of calcification -- which have profound implications for plaque stability and vulnerability to rupture -- are determined by the collagen's content and patterning throughout the plaque.

  3. Histrelin Implant

    MedlinePlus

    ... response to histrelin implant. Your blood sugar and glycosylated hemoglobin (HbA1c) should be checked regularly.Ask your pharmacist any questions you have about histrelin implant.It is important for you to keep a written list of all of the prescription and ...

  4. Reduction of facial wrinkles by hydrolyzed water-soluble egg membrane associated with reduction of free radical stress and support of matrix production by dermal fibroblasts

    PubMed Central

    Jensen, Gitte S; Shah, Bijal; Holtz, Robert; Patel, Ashok; Lo, Donald C

    2016-01-01

    Objective The aim of this study was to evaluate the effects of water-soluble egg membrane (WSEM) on wrinkle reduction in a clinical pilot study and to elucidate specific mechanisms of action using primary human immune and dermal cell-based bioassays. Methods To evaluate the effects of topical application of WSEM (8%) on human skin, an open-label 8-week study was performed involving 20 healthy females between the age of 45 years and 65 years. High-resolution photography and digital analysis were used to evaluate the wrinkle depth in the facial skin areas beside the eye (crow’s feet). WSEM was tested for total antioxidant capacity and effects on the formation of reactive oxygen species by human polymorphonuclear cells. Human keratinocytes (HaCaT cells) were used for quantitative polymerase chain reaction analysis of the antioxidant response element genes Nqo1, Gclm, Gclc, and Hmox1. Evaluation of effects on human primary dermal fibroblasts in vitro included cellular viability and production of the matrix components collagen and elastin. Results Topical use of a WSEM-containing facial cream for 8 weeks resulted in a significant reduction of wrinkle depth (P<0.05). WSEM contained antioxidants and reduced the formation of reactive oxygen species by inflammatory cells in vitro. Despite lack of a quantifiable effect on Nrf2, WSEM induced the gene expression of downstream Nqo1, Gclm, Gclc, and Hmox1 in human keratinocytes. Human dermal fibroblasts treated with WSEM produced more collagen and elastin than untreated cells or cells treated with dbcAMP control. The increase in collagen production was statistically significant (P<0.05). Conclusion The topical use of WSEM on facial skin significantly reduced the wrinkle depth. The underlying mechanisms of this effect may be related to protection from free radical damage at the cellular level and induction of several antioxidant response elements, combined with stimulation of human dermal fibroblasts to secrete high levels of

  5. Effect of Protein Kinase C delta (PKC-δ) Inhibition on the Transcriptome of Normal and Systemic Sclerosis Human Dermal Fibroblasts In Vitro

    PubMed Central

    Wermuth, Peter J.; Addya, Sankar; Jimenez, Sergio A.

    2011-01-01

    Previous studies demonstrated that protein kinase C- δ (PKC-δ) inhibition with the selective inhibitor, rottlerin, resulted in potent downregulation of type I collagen expression and production in normal human dermal fibroblasts and abrogated the exaggerated type I collagen production and expression in fibroblasts cultured from affected skin from patients with the fibrosing disorder systemic sclerosis (SSc). To elucidate the mechanisms involved in the ability of PKC-δ to regulate collagen production in fibroblasts, we examined the effects of PKC-δ inhibition on the transcriptome of normal and SSc human dermal fibroblasts. Normal and SSc human dermal fibroblasts were incubated with rottlerin (5 µM), and their gene expression was analyzed by microarrays. Pathway analysis and gene ontology analysis of differentially expressed genes in each comparison were performed. Identification of significantly overrepresented transcriptional regulatory elements (TREs) was performed using the Promoter Analysis and Interaction Network Toolset (PAINT) program. PKC-δ activity was also inhibited using RNA interference (siRNA) and by treating fibroblasts with a specific PKC-δ inhibitory cell permeable peptide. Differential gene expression of 20 genes was confirmed using real time PCR. PKC-δ inhibition caused a profound change in the transcriptome of normal and SSc human dermal fibroblasts in vitro. Pathway and gene ontology analysis identified multiple cellular and organismal pathways affected by PKC-δ inhibition. Furthermore, both pathway and PAINT analyses indicated that the transcription factor NFκB played an important role in the transcriptome changes induced by PKC-δ inhibition. Multiple genes involved in the degradation of the extracellular matrix components were significantly reduced in SSc fibroblasts and their expression was increased by PKC-δ inhibition. These results indicate that isoform-specific inhibition of PKC-δ profibrotic effects may represent a novel

  6. Anti-photoaging effect of aaptamine in UVB-irradiated human dermal fibroblasts and epidermal keratinocytes.

    PubMed

    Kim, Min-Ji; Woo, Seon Wook; Kim, Myung-Suk; Park, Ji-Eun; Hwang, Jae-Kwan

    2014-12-01

    Chronic exposure to ultraviolet (UV) irradiation causes sunburn, inflammatory responses, skin cancer, and photoaging. Photoaging, in particular, generates reactive oxygen species (ROS) that stimulate mitogen-activated protein kinase (MAPK) signaling and transcription factors. UV irradiation also activates matrix metalloproteinases (MMPs) expression and inactivates collagen synthesis. Aaptamine, a marine alkaloid isolated from the marine sponge, has been reported to have antitumor, antimicrobial, antiviral, and antioxidant activities. However, the photo-protective effects of aaptamine have not been elucidated. In this study, our data demonstrated that aaptamine deactivated UVB-induced MAPK and activator protein-1 signaling by suppressing ROS, resulting in attenuating the expression of MMPs in UVB-irradiated human dermal fibroblasts. Aaptamine also decreased proinflammatory cytokines such as cyclooxygenase-2, tumor necrosis factor-α, interleukin-1β, and nuclear factor-kappa B subunits in UVB-irradiated human keratinocytes. In conclusion, we suggest that aaptamine represents a novel and effective strategy for treatment and prevention of photoaging.

  7. Functional analysis reveals angiogenic potential of human mesenchymal stem cells from Wharton's jelly in dermal regeneration.

    PubMed

    Edwards, Sandra S; Zavala, Gabriela; Prieto, Catalina P; Elliott, Matías; Martínez, Samuel; Egaña, Jose T; Bono, María R; Palma, Verónica

    2014-10-01

    Disorders in skin wound healing are a major health problem that requires the development of innovative treatments. The use of biomaterials as an alternative of skin replacement has become relevant, but its use is still limited due to poor vascularization inside the scaffolds, resulting in insufficient oxygen and growth factors at the wound site. In this study, we have developed a cell-based wound therapy consisting of the application of collagen-based dermal scaffolds containing mesenchymal stem cells from Wharton's jelly (WJ-MSC) in an immunocompetent mouse model of angiogenesis. From our comparative study on the secretion profile between WJ-MSC and adipose tissue-derived MSC, we found a stronger expression of several well-characterized growth factors, such as VEGF-A, angiopoietin-1 and aFGF, which are directly linked to angiogenesis, in the culture supernatant of WJ-MSC, both on monolayer and 3D culture conditions. WJ-MSC proved to be angiogenic both in vitro and in vivo, through tubule formation and CAM assays, respectively. Moreover, WJ-MSC consistently improved the healing response in vivo in a mouse model of human-like dermal repair, by triggering angiogenesis and further providing a suitable matrix for wound repair, without altering the inflammatory response in the animals. Since these cells can be easily isolated, cultured with high expansion rates and cryopreserved, they represent an attractive stem cell source for their use in allogeneic cell transplant and tissue engineering.

  8. Dermal vacuoles in two biopsies of psoriasis.

    PubMed

    Ayva, Sebnem; Erkek, Emel; Atasoy, Pinar

    2008-11-01

    Two patients presented with cutaneous lesions clinically typical of psoriasis. The first case was a 38-year-old man and the second was a 51-year-old woman. To confirm the diagnosis, 4-mm punch biopsy samples were obtained from both patients from the lesions on the knees. Histology in both cases was in favour of psoriasis and also revealed empty vacuoles in the papillary dermis, concentrated at sites of intense lymphocyte infiltration. The empty vacuoles resembled true fat cells or fat globules. They did not reveal positive immunostaining with CD34 antigen, suggesting that they were not lined by endothelial cells. Final histological diagnosis was psoriasis associated with dermal vacuolization.

  9. Acellular dermal matrix in abdominal wall reconstruction.

    PubMed

    Silverman, Ronald P

    2011-09-01

    Abdominal wall reconstruction is a complex and challenging surgical undertaking. While permanent prosthetic mesh is considered the gold standard for minimizing hernia recurrence, placement of synthetic mesh is sometimes imprudent due to contamination or risk of infection. Acellular dermal matrices (ADM) offer an exciting biologic alternative. This article provides a historical perspective on the evolution of complex ventral hernia repair leading up to and including the placement of ADM, an explanation of the biology of ADM as it relates to ventral hernia repair, and a description of the current indications, techniques, benefits, and shortcomings of its use in the abdominal wall.

  10. Relationships between molecular mobility, fibrillogenesis of collagen molecules, and the inflammatory response: an experimental study in vitro and in vivo.

    PubMed

    Nam, Kwangwoo; Seo, Ji-Hun; Kimura, Tsuyoshi; Yui, Nobuhiko; Kishida, Akio

    2014-11-01

    This study was designed to investigate the in vitro adsorption and fibrillogenesis of collagen on a surface with dynamic properties and to investigate how this surface affected the inflammatory response in vivo. Investigation of collagen-surface interactions is directly related to the control of wound healing where collagen adsorption, fibrillization, deposition, and maturation occur. ABA-type block copolymers, composed of polyrotaxane (which possesses α-cyclodextrin threaded along poly(ethylene glycol)) and hydrophobic terminal segments, were used to prepare mobile surfaces with representative dynamic properties. Analyses using a quartz crystal microbalance with dissipation monitoring (QCM-D) indicated that increasing the mobility of the polymer on the surface led to the formation of a soft collagen layer. The collagens in this layer had rearranged, leading to the formation of thicker collagen fibrils by lateral aggregation. When a surface with a high molecular mobility was subcutaneously implanted into rats, collagen rearrangement occurred leading to suppression of macrophage recruitment at the interface and the formation of a fibrotic capsule around the implant. These results suggest that surface mobility on an implant is an important parameter for normal wound healing. PMID:25112908

  11. Relationships between molecular mobility, fibrillogenesis of collagen molecules, and the inflammatory response: an experimental study in vitro and in vivo.

    PubMed

    Nam, Kwangwoo; Seo, Ji-Hun; Kimura, Tsuyoshi; Yui, Nobuhiko; Kishida, Akio

    2014-11-01

    This study was designed to investigate the in vitro adsorption and fibrillogenesis of collagen on a surface with dynamic properties and to investigate how this surface affected the inflammatory response in vivo. Investigation of collagen-surface interactions is directly related to the control of wound healing where collagen adsorption, fibrillization, deposition, and maturation occur. ABA-type block copolymers, composed of polyrotaxane (which possesses α-cyclodextrin threaded along poly(ethylene glycol)) and hydrophobic terminal segments, were used to prepare mobile surfaces with representative dynamic properties. Analyses using a quartz crystal microbalance with dissipation monitoring (QCM-D) indicated that increasing the mobility of the polymer on the surface led to the formation of a soft collagen layer. The collagens in this layer had rearranged, leading to the formation of thicker collagen fibrils by lateral aggregation. When a surface with a high molecular mobility was subcutaneously implanted into rats, collagen rearrangement occurred leading to suppression of macrophage recruitment at the interface and the formation of a fibrotic capsule around the implant. These results suggest that surface mobility on an implant is an important parameter for normal wound healing.

  12. Microarray-based identification of aminopeptidase N target genes in keratinocyte conditioned medium-stimulated dermal fibroblasts.

    PubMed

    Lai, Amy; Ghaffari, Abdi; Li, Yunyuan; Ghahary, Aziz

    2012-03-01

    Of the many processes that affect the outcome of wound repair, epidermal-dermal interactions are essential to extracellular matrix (ECM) remodeling and in particular, soluble factors released by keratinocytes are known to have a direct impact on the production of ECM by dermal fibroblasts. Aminopeptidase N (APN) has recently been proposed as a cell-surface receptor for stratifin and is responsible for the stratifin-mediated matrix metalloproteinase-1 (MMP-1) upregulation in fibroblasts. The present study examines whether modulation of APN gene expression has any impact on the fibroblast ECM gene expression profile. The result reveals that in the presence of keratinocyte-derived soluble factors, transient knockdown of APN in dermal fibroblasts affects the expression of key ECM components such as fibronectin, tenascin-C, MMP-1, MMP-3, and MMP-12. The regulatory effects of APN on fibronectin and selective MMPs appear to be associated with receptor-mediated signal transduction independently of its peptidase activity. On the contrary, inhibition of the APN enzymatic activity by bestatin significantly reduces the tenascin-C expression and enhances the contraction of fibroblast-populated collagen gel, suggesting an activity-dependent regulation of fibroblast contractility by APN. The overall effects of APN on the expression of fibronectin, tenascin-C, and MMPs in fibroblasts propose an important role for APN in the regulation of keratinocyte-mediated ECM remodeling and fibroblast contractile activity. PMID:22065384

  13. A Novel Compound Rasatiol Isolated from Raphanus sativus Has a Potential to Enhance Extracellular Matrix Synthesis in Dermal Fibroblasts

    PubMed Central

    Roh, Seok-Seon; Park, Seung-Bae; Park, Seong-Mo; Choi, Byoung Wook; Lee, Min-Ho; Hwang, Yul-Lye; Kim, Chang Hun; Jeong, Hyun-Ah; Kim, Chang Deok

    2013-01-01

    Background The fibrous proteins of extracellular matrix (ECM) produced by dermal fibroblast contributes to the maintenance of connective tissue integrity. Objective This study is carried out to identify the bioactive ingredient from natural products that enhances ECM production in dermal fibroblasts. Methods Bioassay-directed fractionation was used to isolate the active ingredient from natural extracts. The effects of rasatiol (isolated from Raphanus sativus) on ECM production in primary cultured human dermal fibroblasts was investigated by enzyme linked immunosorbent assay and western blot analysis. Results Rasatiol accelerated fibroblast growth in a dose-dependent manner and increased the production of type 1 collagen, fibronectin and elastin. Phosphorylation of p42/44 extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, and Akt was remarkably increased by rasatiol, indicating that enhanced ECM production is linked to the activation of intracellular signaling cascades. Conclusion These results indicate that rasatiol stimulates the fibrous components of ECM production, and may be applied to the maintenance of skin texture. PMID:24003274

  14. The use of collagen-based matrices in the treatment of full-thickness wounds.

    PubMed

    Petersen, Wiebke; Rahmanian-Schwarz, Afshin; Werner, Jan-Ole; Schiefer, Jennifer; Rothenberger, Jens; Hübner, Gunnar; Schaller, Hans-Eberhard; Held, Manuel

    2016-09-01

    Chronic and complex full-thickness wounds have become increasingly prevalent. Besides autologous skin transplantation, innovative wound dressing products have gained interest, as the functional and esthetic outcome is still limited. In this respect, the effect of a novel modifiable collagen-gelatin fleece on the healing of deep dermal wounds was examined and compared with untreated controls and Matriderm(®). A total of 48 full-thickness skin defects were generated on six minipigs and treated with the novel collagen-gelatin fleece of different thicknesses in single or multiple application (n=36) or treated with Matriderm(®) in a single application (n=6), or the wounds were left untreated (n=6). Wound healing was analyzed planimetrically by wound closure per time and histologically with regard to epidermal thickness and cell density. Compared to untreated wounds, wound closure per time and histological skin quality with regard to the mean epidermal thickness and epidermal cell amount were enhanced in both treatment groups. Overall, the best results for the novel collagen-gelatin fleece were achieved for multiple applications with a thickness of 150g/m(2). The novel biomaterial shows accelerated and improved dermal wound repair in a minipig model. As the manufacturing process of the scaffold allows the integration of bioactive substances such as antibiotics and growth factors, we intend to design a composite biomaterial using this scaffold as a carrier matrix. PMID:27297940

  15. Collagen XVII Shedding Suppresses Re-Epithelialization by Directing Keratinocyte Migration and Dampening mTOR Signaling.

    PubMed

    Jacków, Joanna; Löffek, Stefanie; Nyström, Alexander; Bruckner-Tuderman, Leena; Franzke, Claus-Werner

    2016-05-01

    Transmembrane collagen XVII is traditionally viewed as an important hemidesmosomal attachment component that promotes stable dermal-epidermal adhesion in the skin. However, its expression is highly elevated at the leading edges of cutaneous wounds or invasive carcinomas, suggesting alternative functions in cell migration. The collagenous ectodomain of collagen XVII is constitutively shed from the cell surface by a disintegrin and metalloproteinases, and this shedding is strongly induced during wound healing. Recently, we investigated the physiological relevance of collagen XVII shedding by generating knock-in mice, which exclusively express a functional non-sheddable collagen XVII mutant. Prevention of ectodomain shedding in these mice caused no spontaneous phenotype in resting skin, but accelerated re-epithelialization on skin wounding. Here, we investigated the mechanistic function of shedding during wound healing. Using the non-shedding collagen XVII mice as a model, we uncovered ectodomain shedding as a highly dynamic modulator of in vivo proliferation and motility of activated keratinocytes through tight coordination of α6β4 integrin-laminin-332 interactions and dampening of mechanistic target of rapamycin signaling at the wound edges. Thus, our studies identify ectodomain shedding of collagen XVII as an interactive platform that translates shedding into a signal for directed cell growth and motility during skin regeneration.

  16. Development of a novel biomaterial, hydroxyapatite/collagen (HAp/Col) composite for medical use.

    PubMed

    Itoh, Soichiro; Kikuchi, Masanori; Koyama, Yosihisa; Matumoto, Hiroko N; Takakuda, Kazuo; Shinomiya, Kenichi; Tanaka, Junzo

    2005-01-01

    A hydroxyapatite/type I collagen (HAp/Col) composite, aligning hydroxyapatite nano-crystals along collagen molecules, has been synthesized. The biocompatibility, osteoconductivity and efficacy as an rhBMP-2 carrier of this novel biomaterial implanted in the weight-bearing site have been examined. The HAp/Col implants adsorbing 0 or 400 microg/ml of rhBMP-2 were implanted into bone defects of tibiae in 3 beagle dogs and fixed according to the Ilizarov method. As a control, bone defects of 20 mm remaining in 2 beagle dogs and the dogs were allowed to walk using a Ilizarov external skeletal fixator. The radiological and histological findings suggest that the implants induce bone remodeling units and are a superior carrier of rhBMP-2 due to the stimulation of early callus and new bone formation. As a next step, anterior fusion was carried out on 6 beagle dogs with the implants adsorbing 400 microg/ml of rhBMP-2, and 9 dogs with the implants without rhBMP-2. In 3 dogs of the rhBMP-treated group, as well as 6 dogs of the non-rhBMP-treated group, the implant was fixed with a poly-L-lactide plate. Histological and radiographical analysis suggest that enhancement of callus formation and bone bridging by rhBMP-treatment is effective to prevent collapse of the implant.

  17. Histological evaluation of dermal tissue remodeling with the 1444-nm neodymium:yttrium-aluminum-garnet laser in in vivo model.

    PubMed

    Kim, Ji Hoon; Min, Kyung Hee; Heo, Chan Yeong; Baek, Rong Min; Park, Hyo Jin; Youn, Sang Woong; Kim, Eun Hee

    2013-09-01

    Laser lipolysis has a skin tightening effect by heating the deep dermis, in addition to the removal of fat tissues. The 1444-nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser has been expected to be more effective and safe for laser lipolysis, due to higher affinity to fat and water, than 1064-nm and 1320-nm wavelengths. The purpose of this study was to evaluate the skin tightening effect of the 1444-nm Nd:YAG laser through in vivo guinea pig models. The 1444-nm Nd:YAG laser was used to irradiate shaved dorsal skin of the guinea pigs and compared with controls (no power, only tunneling). Immediately, 1 week, 1 month and 3 months after laser administration, full-thickness skins were harvested and to evaluate dermal thickness, collagen organization, fibroblast proliferation, and intensity of elastic fibers and mucopolysaccharides, using hematoxylin-eosin, Masson-trichrome, Verhoeff's stain and Alcian blue stain. Dermal thickness showed an increase with time in all groups. In collagen organization, fibroblast proliferation, and intensity of elastic fibers and mucopolysaccharides, the treatment groups were higher than those of the control group, overall. Our study showed that the 1444-nm Nd:YAG laser appeared to be effective for the skin tightening effect in in vivo guinea pig models. The 1444-nm Nd:YAG laser can be used for skin tightening, as well as reduction of fat tissues.

  18. Transformation of amorphous calcium carbonate to rod-like single crystal calcite via "copying" collagen template.

    PubMed

    Xue, Zhonghui; Hu, Binbin; Dai, Shuxi; Du, Zuliang

    2015-10-01

    Collagen Langmuir films were prepared by spreading the solution of collagen over deionized water, CaCl2 solution and Ca(HCO3)2 solution. Resultant collagen Langmuir monolayers were then compressed to a lateral pressure of 10 mN/m and held there for different duration, allowing the crystallization of CaCO3. The effect of crystallization time on the phase composition and microstructure of CaCO3 was investigated. It was found that amorphous calcium carbonate (ACC) was obtained at a crystallization time of 6 h. The amorphous CaCO3 was transformed to rod-like single crystal calcite crystals at an extended crystallization time of 12 h and 24 h, via "copying" the symmetry and dimensionalities of collagen fibers. Resultant calcite crystallites were well oriented along the longitudinal axis of collagen fibers. The ordered surface structure of collagen fibers and electrostatic interactions played key roles in tuning the oriented nucleation and growth of the calcite crystallites. The mineralized collagen possessing both desired mechanical properties of collagen fiber and good biocompatibility of calcium carbonate may be assembled into an ideal biomaterial for bone implants.

  19. Mesenchymal stem cells induce dermal fibroblast responses to injury

    SciTech Connect

    Smith, Andria N.; Willis, Elise; Chan, Vincent T.; Muffley, Lara A.; Isik, F. Frank; Gibran, Nicole S.; Hocking, Anne M.

    2010-01-01

    Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. When co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury.

  20. Case report: pseudotail with dermal sinus tract and tethered cord.

    PubMed

    Clark, Paul; Davidson, Laurence

    2016-09-01

    A pseudotail is a very rare, dermal appendage arising from the lumbosacral region with an association with spinal dysraphism. We report a case of a pseudotail in a healthy newborn female with sonographic imaging of a tethered cord and dermal sinus tract with MRI and surgical correlation. PMID:27635168

  1. Spectrum of PORCN mutations in Focal Dermal Hypoplasia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Focal Dermal Hypoplasia (FDH), also known as Goltz syndrome (OMIM 305600), is a genetic disorder that affects multiple organ systems early in development. Features of FDH include skin abnormalities, (hypoplasia, atrophy, linear pigmentation, and herniation of fat through dermal defects); papillomas...

  2. IN VITRO DERMAL ABSORPTION OF FLAME RETARDANT CHEMICALS

    EPA Science Inventory

    ABSTRACT
    The use of flame retardant chemicals in furniture fabric could pose a potential health risk to consumers from dermal absorption of these compounds. The objective of this study was to examine the in vitro dermal absorption of two flame retardant chemicals, [14C]-d...

  3. Mesenchymal stem cells induce dermal fibroblast responses to injury.

    PubMed

    Smith, Andria N; Willis, Elise; Chan, Vincent T; Muffley, Lara A; Isik, F Frank; Gibran, Nicole S; Hocking, Anne M

    2010-01-01

    Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. When co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury.

  4. The structural and optical properties of type III human collagen biosynthetic corneal substitutes

    PubMed Central

    Hayes, Sally; Lewis, Phillip; Islam, M. Mirazul; Doutch, James; Sorensen, Thomas; White, Tomas; Griffith, May; Meek, Keith M.

    2015-01-01

    The structural and optical properties of clinically biocompatible, cell-free hydrogels comprised of synthetically cross-linked and moulded recombinant human collagen type III (RHCIII) with and without the incorporation of 2-methacryloyloxyethyl phosphorylcholine (MPC) were assessed using transmission electron microscopy (TEM), X-ray scattering, spectroscopy and refractometry. These findings were examined alongside similarly obtained data from 21 human donor corneas. TEM demonstrated the presence of loosely bundled aggregates of fine collagen filaments within both RHCIII and RHCIII-MPC implants, which X-ray scattering showed to lack D-banding and be preferentially aligned in a uniaxial orientation throughout. This arrangement differs from the predominantly biaxial alignment of collagen fibrils that exists in the human cornea. By virtue of their high water content (90%), very fine collagen filaments (2–9 nm) and lack of cells, the collagen hydrogels were found to transmit almost all incident light in the visible spectrum. They also transmitted a large proportion of UV light compared to the cornea which acts as an effective UV filter. Patients implanted with these hydrogels should be cautious about UV exposure prior to regrowth of the epithelium and in-growth of corneal cells into the implants. PMID:26159106

  5. The structural and optical properties of type III human collagen biosynthetic corneal substitutes.

    PubMed

    Hayes, Sally; Lewis, Phillip; Islam, M Mirazul; Doutch, James; Sorensen, Thomas; White, Tomas; Griffith, May; Meek, Keith M

    2015-10-01

    The structural and optical properties of clinically biocompatible, cell-free hydrogels comprised of synthetically cross-linked and moulded recombinant human collagen type III (RHCIII) with and without the incorporation of 2-methacryloyloxyethyl phosphorylcholine (MPC) were assessed using transmission electron microscopy (TEM), X-ray scattering, spectroscopy and refractometry. These findings were examined alongside similarly obtained data from 21 human donor corneas. TEM demonstrated the presence of loosely bundled aggregates of fine collagen filaments within both RHCIII and RHCIII-MPC implants, which X-ray scattering showed to lack D-banding and be preferentially aligned in a uniaxial orientation throughout. This arrangement differs from the predominantly biaxial alignment of collagen fibrils that exists in the human cornea. By virtue of their high water content (90%), very fine collagen filaments (2-9 nm) and lack of cells, the collagen hydrogels were found to transmit almost all incident light in the visible spectrum. They also transmitted a large proportion of UV light compared to the cornea which acts as an effective UV filter. Patients implanted with these hydrogels should be cautious about UV exposure prior to regrowth of the epithelium and in-growth of corneal cells into the implants. PMID:26159106

  6. A Direct Comparison of Alloderm-Ready to Use (RTU) and DermACELL in Immediate Breast Implant Reconstruction

    PubMed Central

    Salzberg, C. Andrew

    2016-01-01

    The objective of this study was to compare the 2 leading human acellular dermal matrices in breast reconstruction with implants. This retrospective study draws on the experience of 2 expert surgeons with a history of long-standing use of the Alloderm-RTU (LifeCell Corporation, Branchburg, NJ) product who switched to the DermACELL acellular dermal matrix (LifeNet Health, Virgina Beach, Va) product. The consecutive nature of these data over this change allowed comparison between the 2 products without the confounding effects of patient selection or change in technique. The postoperative complications of seroma, infection, implant loss, and unplanned return to the operating room were studied, and no statistical differences were noted between these 2 products. The overall complications rates were low, with implant loss and infection less than 2% in 249 cases. Recommendations are for continued use of acellular dermal matrix in breast reconstruction and product selection based on price and availability.

  7. A Direct Comparison of Alloderm-Ready to Use (RTU) and DermACELL in Immediate Breast Implant Reconstruction

    PubMed Central

    Salzberg, C. Andrew

    2016-01-01

    The objective of this study was to compare the 2 leading human acellular dermal matrices in breast reconstruction with implants. This retrospective study draws on the experience of 2 expert surgeons with a history of long-standing use of the Alloderm-RTU (LifeCell Corporation, Branchburg, NJ) product who switched to the DermACELL acellular dermal matrix (LifeNet Health, Virginia Beach, Va) product. The consecutive nature of these data over this change allowed comparison between the 2 products without the confounding effects of patient selection or change in technique. The postoperative complications of seroma, infection, implant loss, and unplanned return to the operating room were studied, and no statistical differences were noted between these 2 products. The overall complications rates were low, with implant loss and infection less than 2% in 249 cases. Recommendations are for continued use of acellular dermal matrix in breast reconstruction and product selection based on price and availability. PMID:27602176

  8. A Direct Comparison of Alloderm-Ready to Use (RTU) and DermACELL in Immediate Breast Implant Reconstruction.

    PubMed

    Zenn, Michael R; Salzberg, C Andrew

    2016-01-01

    The objective of this study was to compare the 2 leading human acellular dermal matrices in breast reconstruction with implants. This retrospective study draws on the experience of 2 expert surgeons with a history of long-standing use of the Alloderm-RTU (LifeCell Corporation, Branchburg, NJ) product who switched to the DermACELL acellular dermal matrix (LifeNet Health, Virgina Beach, Va) product. The consecutive nature of these data over this change allowed comparison between the 2 products without the confounding effects of patient selection or change in technique. The postoperative complications of seroma, infection, implant loss, and unplanned return to the operating room were studied, and no statistical differences were noted between these 2 products. The overall complications rates were low, with implant loss and infection less than 2% in 249 cases. Recommendations are for continued use of acellular dermal matrix in breast reconstruction and product selection based on price and availability. PMID:27602176

  9. Development and characterization of a rapid polymerizing collagen for soft tissue augmentation

    PubMed Central

    Devore, Dale; Zhu, Jiaxun; Brooks, Robert; McCrate, Rebecca Rone; Grant, David A.

    2015-01-01

    Abstract A liquid collagen has been developed that fibrilizes upon injection. Rapid polymerizing collagen (RPC) is a type I porcine collagen that undergoes fibrillization upon interaction with ionic solutions, such as physiological solutions. The ability to inject liquid collagen would be beneficial for many soft tissue augmentation applications. In this study, RPC was synthesized and characterized as a possible dermal filler. Transmission electron microscopy, ion induced RPC fibrillogenesis tests, collagenase resistance assay, and injection force studies were performed to assess RPC's physicochemical properties. An in vivo study was performed which consisted of a 1‐, 3‐, and 6‐month study where RPC was injected into the ears of miniature swine. The results demonstrated that the liquid RPC requires low injection force (<7 N); fibrillogenesis and banding of collagen occurs when RPC is injected into ionic solutions, and RPC has enhanced resistance to collagenase breakdown. The in vivo study demonstrated long‐term biocompatibility with low irritation scores. In conclusion RPC possesses many of the desirable properties of a soft tissue augmentation material. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 758–767, 2016. PMID:26488368

  10. Cochlear implant

    MedlinePlus

    ... implant. These specialists may include: Audiologists Speech therapists Ear, nose, and throat doctors (otolaryngologists) This is a very important part of the process. You will need to work closely with your team of specialists to get ...

  11. Cochlear Implants

    MedlinePlus

    ... additional visits are needed for activating, adjusting, and programming the various electrodes that have been implanted. Also, ... to the center for checkups once the final programming is made to the speech processor. Both children ...

  12. Novel PORCN mutations in focal dermal hypoplasia.

    PubMed

    Froyen, G; Govaerts, K; Van Esch, H; Verbeeck, J; Tuomi, M-L; Heikkilä, H; Torniainen, S; Devriendt, K; Fryns, J-P; Marynen, P; Järvelä, I; Ala-Mello, S

    2009-12-01

    Focal dermal hypoplasia (FDH), Goltz or Goltz-Gorlin syndrome, is an X-linked dominant multisystem disorder characterized primarily by involvement of the skin, skeletal system and eyes. We screened for mutations in the PORCN gene in eight patients of Belgian and Finnish origin with firm clinical suspicion of FDH. First, we performed quantitative PCR (qPCR) analysis to define the copy number at this locus. Next, we sequenced the coding regions and flanking intronic sequences of the PORCN gene. Three de novo mutations were identified in our patients with FDH: a 150-kb deletion removing six genes including PORCN, as defined by qPCR and X-array-CGH, and two heterozygous missense mutations; c.992T>G (p.L331R) in exon 11 and c.1094G>A (p.R365Q) in exon 13 of the gene. Both point mutations changed highly conserved amino acids and were not found in 300 control X chromosomes. The three patients in whom mutations were identified all present with characteristic dermal findings together with limb manifestations, which were not seen in our mutation-negative patients. The clinical characteristics of our patients with PORCN mutations were compared with the previously reported mutation-positive cases. In this report, we summarize the literature on PORCN mutations and associated phenotypes.

  13. Lipid nanoparticles for dermal drug delivery.

    PubMed

    Kakadia, Pratibha G; Conway, Barbara R

    2015-01-01

    Lipid based drug delivery systems have been widely studied and reported over the past decade and offer a useful alternative to other colloidal drug delivery systems. Skin is a popular route of drug delivery for locally and systemically acting drugs and nanoparticles are reported as a potential formulation strategy for dermal delivery. Although the skin acts as a natural physical barrier against penetration of foreign materials, including particulates, opportunities exist for the delivery of therapeutic nanoparticles, especially in diseased and damaged skin and via appendageal routes such as the openings of hair follicles. The extent and ability of nanoparticles to penetrate into the underlying viable tissue is still the subject of debate although recent studies have identified the follicular route as the most likely route of entry; this influences the potential applications of these dosage forms as a drug delivery strategy. This paper reviews present state of art of lipid-based nanocarriers focussing on solid lipid nanoparticles, nanostructured lipid carriers and nanoemulsions, their production methods, potential advantages and applications in dermal drug delivery. PMID:25925115

  14. Type I Collagen and Collagen Mimetics as Angiogenesis Promoting Superpolymers

    SciTech Connect

    Twardowski, T.; Fertala, A.; Orgel, J.P.R.O.; San Antonio, J.D.

    2008-07-18

    Angiogenesis, the development of blood vessels from the pre-existing vasculature, is a key component of embryogenesis and tissue regeneration. Angiogenesis also drives pathologies such as tumor growth and metastasis, and hemangioma development in newborns. On the other hand, promotion of angiogenesis is needed in tissues with vascular insufficiencies, and in bioengineering, to endow tissue substitutes with appropriate microvasculatures. Therefore, much research has focused on defining mechanisms of angiogenesis, and identifying pro- and anti-angiogenic molecules. Type I collagen, the most abundant protein in humans, potently stimulates angiogenesis in vitro and in vivo. Crucial to its angiogenic activity appears to be ligation and possibly clustering of endothelial cell (EC) surface {alpha}1{beta}1/{alpha}2{beta}1 integrin receptors by the GFPGER502-507 sequence of the collagen fibril. However, additional aspects of collagen structure and function that may modulate its angiogenic properties are discussed. Moreover, type I collagen and fibrin, another angiogenic polymer, share several structural features. These observations suggest strategies for creating 'angiogenic superpolymers', including: modifying type I collagen to influence its biological half-life, immunogenicity, and integrin binding capacity; genetically engineering fibrillar collagens to include additional integrin binding sites or angiogenic determinants, and remove unnecessary or deleterious sequences without compromising fibril integrity; and exploring the suitability of poly(ortho ester), PEG-lysine copolymer, tubulin, and cholesteric cuticle as collagen mimetics, and suggesting means of modifying them to display ideal angiogenic properties. The collagenous and collagen mimetic angiogenic superpolymers described here may someday prove useful for many applications in tissue engineering and human medicine.

  15. Lymphocytic and Collagenous Colitis.

    PubMed

    Cruz-Correa; Giardiello

    2000-06-01

    Patients with symptomatic collagenous-lymphocytic colitis should eliminate dietary secretagogues such as caffeine- or lactose-containing food from their diet. When possible, use of nonsteroidal anti-inflammatory drugs should be discontinued. If steatorrhea is documented, a low-fat diet may be helpful. In the presence of bile salt malabsorption, binding resins such as cholestyramine might be useful. Nonspecific diarrheal agents such as loperamide hydrochloride, diphenoxylate hydrochloride and atropine, deodorized tincture of opium, or codeine might prove effective in some patients. Antibacterial agents such as bismuth subsalicylate (8 chewable 262-mg tablets daily) have been effective in symptom control. Metronidazole and erythromycin achieve response rates of 60%. Sulfasalazine, at the usual dose of 2 to 4 g daily, used in collagenous-lymphocytic colitis, demonstrated cessation of diarrhea in 1 to 2 weeks for 50% of patients. Other 5-aminosalicylic (5-ASA) compounds are preferred for patients with a history of sulfa allergy, and those who experience adverse reactions to sulfasalazine. Adrenocorticoid medication is reserved for patients whose conventional treatment with sulfasalazine or 5-ASA has failed. Resolution of diarrhea has been documented in 80% to 90% of patients within 1 week of treatment, however, in most patients, long-term therapy is required. Surgical management is reserved for those patients with disease refractory to medical therapy. Colectomy with ileostomy resulted in clinical and histologic resolution in small case series. If there is no abatement of symptoms, rule out other etiologies of diarrhea such as thyroid dysfunction, celiac disease, or bacterial overgrowth. PMID:11097741

  16. Contraceptive implants.

    PubMed

    McDonald-Mosley, Raegan; Burke, Anne E

    2010-03-01

    Implantable contraception has been extensively used worldwide. Implants are one of the most effective and reversible methods of contraception available. These devices may be particularly appropriate for certain populations of women, including women who cannot use estrogen-containing contraception. Implants are safe for use by women with many chronic medical problems. The newest implant, Implanon (Organon International, Oss, The Netherlands), is the only device currently available in the United States and was approved in 2006. It is registered for 3 years of pregnancy prevention. Contraceptive implants have failure rates similar to tubal ligation, and yet they are readily reversible with a return to fertility within days of removal. Moreover, these contraceptive devices can be safely placed in the immediate postpartum period, ensuring good contraceptive coverage for women who may be at risk for an unintended pregnancy. Irregular bleeding is a common side effect for all progestin-only contraceptive implants. Preinsertion counseling should address possible side effects, and treatment may be offered to women who experience prolonged or frequent bleeding.

  17. Collagen fibril formation during development

    SciTech Connect

    Fleischmajer, R.; Perlish, J.S.; Timpl, R.; Olsen, B.R.

    1987-05-01

    Studies with embryonic skin and bone suggested that the aminopropeptide (AP) and carboxylpropeptide (CP) of type I pro-callagen (pro-col) play a role in fibril formation. Chick leg metatarsal tendons were studied by electron microscopy. AP and CP of type I pro-col were purified from chick leg tendons; antibodies developed in rabbits and purity tested by radioimmunoassays. Antibodies were used for immunofluorescence microscopy (IFM) and immunoblotting (IB). The peritendineum, consisting of thin 20-30 nm fibrils, revealed the AP of type I and type III procol. In the tendon area, collagen fibrils were arranged within small compartments and were of uniform diameter at 10d, 14d and 18d. However, beyond 21d, there was confluency of the compartments and a wide range of fibril diameters. IFM revealed fine streaks of collagen, staining with the AP of type I throughout the tendon. The CP was mainly intracellular with only a small amount present in the extracellular space. IB revealed procollagen, pN-collagen (AP+collagen) and pC-collagen, (CP+collagen) at all stages of development. Ratios of pN/pC collagen, determined by spectrophotometric scanning of autoradiographs, correlated well with the distribution of fibril diameter. This study suggests the hypothesis that AP initiates fibrillogenesis while CP may regulate additional fibril growth.

  18. Interleukin-1β attenuates myofibroblast formation and extracellular matrix production in dermal and lung fibroblasts exposed to transforming growth factor-β1.

    PubMed

    Mia, Masum M; Boersema, Miriam; Bank, Ruud A

    2014-01-01

    One of the most potent pro-fibrotic cytokines is transforming growth factor (TGFβ). TGFβ is involved in the activation of fibroblasts into myofibroblasts, resulting in the hallmark of fibrosis: the pathological accumulation of collagen. Interleukin-1β (IL1β) can influence the severity of fibrosis, however much less is known about the direct effects on fibroblasts. Using lung and dermal fibroblasts, we have investigated the effects of IL1β, TGFβ1, and IL1β in combination with TGFβ1 on myofibroblast formation, collagen synthesis and collagen modification (including prolyl hydroxylase, lysyl hydroxylase and lysyl oxidase), and matrix metalloproteinases (MMPs). We found that IL1β alone has no obvious pro-fibrotic effect on fibroblasts. However, IL1β is able to inhibit the TGFβ1-induced myofibroblast formation as well as collagen synthesis. Glioma-associated oncogene homolog 1 (GLI1), the Hedgehog transcription factor that is involved in the transformation of fibroblasts into myofibroblasts is upregulated by TGFβ1. The addition of IL1β reduced the expression of GLI1 and thereby also indirectly inhibits myofibroblast formation. Other potentially anti-fibrotic effects of IL1β that were observed are the increased levels of MMP1, -2, -9 and -14 produced by fibroblasts exposed to TGFβ1/IL1β in comparison with fibroblasts exposed to TGFβ1 alone. In addition, IL1β decreased the TGFβ1-induced upregulation of lysyl oxidase, an enzyme involved in collagen cross-linking. Furthermore, we found that lung and dermal fibroblasts do not always behave identically towards IL1β. Suppression of COL1A1 by IL1β in the presence of TGFβ1 is more pronounced in lung fibroblasts compared to dermal fibroblasts, whereas a higher upregulation of MMP1 is seen in dermal fibroblasts. The role of IL1β in fibrosis should be reconsidered, and the differences in phenotypical properties of fibroblasts derived from different organs should be taken into account in future anti

  19. Role of seaweed laminaran from Saccharina longicruris on matrix deposition during dermal tissue-engineered production.

    PubMed

    Ayoub, Akram; Pereira, Jadson Moreira; Rioux, Laurie-Eve; Turgeon, Sylvie L; Beaulieu, Martin; Moulin, Véronique J

    2015-04-01

    Our laboratory has developed a technique to reconstruct in vitro tissue from human cells using the self-assembly tissue-engineering method, which utilizes the ability of fibroblasts to deposit the matrix they secrete. The time necessary for tissue construction, several weeks, is a drawback for many clinical uses. We hypothesized that the addition of laminaran can increase the deposition of matrix, speeding up the production of the tissue. Laminaran was isolated from the brown seaweed Saccharina longicruris harvested in Canada and its structure was evaluated. Laminaran is a small molecular weight polysaccharide composed of linear glucose chains. Monolayer-cultured human skin fibroblasts were cultured in the presence of laminaran with ascorbate for 7 or 35 days to produce a dermis. Treatment did not induce any variation in the growth rate or alpha smooth muscle actin content but it did increase the deposition of collagen I in a dose-dependent manner. After 35 days, the reconstructed dermal thickness was increased when laminaran was added, and collagen I deposition and MMP activity were also significantly increased. Thus, laminaran can be used to increase the rate of production of reconstructed self-assembled dermis and can also potentially be used in cosmetic or therapeutic creams to stimulate matrix production.

  20. Engineered dermal equivalent tissue in vitro by assembly of microtissue precursors.

    PubMed

    Palmiero, Carmela; Imparato, Giorgia; Urciuolo, Francesco; Netti, Paolo

    2010-07-01

    Tissue-engineered constructs can be fabricated by the assembly of smaller building blocks in order to mimic much of the native biology that is often made from repeating functional units. Our aim was to realize a three-dimensional (3-D) tissue-like construct in vitro by inducing the assembly of functional micrometric tissue precursors (microTPs). MicroTPs were obtained by dynamic cell seeding of bovine fibroblasts on porous gelatine microcarriers using a spinner flask bioreactor. During the dynamic seeding, cells adhered, proliferated and synthesized a thin layer of extracellular matrix (ECM) in and around the macroporous beads, generating the microTPs. The analysis showed that the ECM produced was rich in type I collagen. The cells and ECM layer around the microTPs allowed their biological sintering via cell-cell and cell-matrix interaction after only a few days of dynamic seeding. The assembling ability of microTPs was exploited by placing them in a maturation chamber. After 1 week of culture disc-shaped constructs (1cm in diameter, 1mm in thickness) of completely assembled microTPs were collected. The biohybrid obtained presented both a homogeneous and compact aspect. Moreover, histological and immunohistochemical analyses revealed an abundant ECM, rich in type I collagen, interconnecting the microTPs. The results obtained in this survey pave the way to realizing a 3-D dermal tissue equivalent by means of a bottom-up tissue engineering approach.

  1. Effect of cross-linking reagents for hyaluronic acid hydrogel dermal fillers on tissue augmentation and regeneration.

    PubMed

    Yeom, Junseok; Bhang, Suk Ho; Kim, Byung-Soo; Seo, Moo Seok; Hwang, Eui Jin; Cho, Il Hwan; Park, Jung Kyu; Hahn, Sei Kwang

    2010-02-17

    A novel, biocompatible, and nontoxic dermal filler using hyaluronic acid (HA) hydrogels was successfully developed for tissue augmentation applications. Instead of using highly reactive cross-linkers such as divinyl sulfone (DVS) for Hylaform, 1,4-butanediol diglycidyl ether (BDDE) for Restylane, and 1,2,7,8-diepoxyoctane (DEO) for Puragen, HA hydrogels were prepared by direct amide bond formation between the carboxyl groups of HA and hexamethylenediamine (HMDA) with an optimized carboxyl group modification for effective tissue augmentation. The HA-HMDA hydrogels could be prepared within 5 min by the addition of HMDA to HA solution activated with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and 1-hydroxybenzotriazole monohydrate (HOBt). Five kinds of samples, a normal control, a negative control, a positive control of Restylane, adipic acid dihydrazide grafted HA (HA-ADH) hydrogels, and HA-HMDA hydrogels, were subcutaneously injected to wrinkled model mice. According to the image analysis on dorsal skin augmentation, the HA-HMDA hydrogels exhibited the best tissue augmentation effect being stable longer than 3 months. Furthermore, histological analyses after hematoxylin-eosin (H&E) and Masson's trichrome staining revealed the excellent biocompatibility and safety of HA-HMDA hydrogels. The dermal thickness and the dermal collagen density in wrinkled mice after treatment with HA-HMDA hydrogels for 12 weeks were comparable to those of normal mice. Compared with HA-DVS hydrogels and Restylane, the excellent tissue augmentation by HA-HMDA hydrogels might be ascribed to the biocompatible residues of amine groups in the cross-linker of HMDA. The HA-HMDA hydrogels will be investigated further as a novel dermal filler for clinical applications.

  2. Effect of cross-linking reagents for hyaluronic acid hydrogel dermal fillers on tissue augmentation and regeneration.

    PubMed

    Yeom, Junseok; Bhang, Suk Ho; Kim, Byung-Soo; Seo, Moo Seok; Hwang, Eui Jin; Cho, Il Hwan; Park, Jung Kyu; Hahn, Sei Kwang

    2010-02-17

    A novel, biocompatible, and nontoxic dermal filler using hyaluronic acid (HA) hydrogels was successfully developed for tissue augmentation applications. Instead of using highly reactive cross-linkers such as divinyl sulfone (DVS) for Hylaform, 1,4-butanediol diglycidyl ether (BDDE) for Restylane, and 1,2,7,8-diepoxyoctane (DEO) for Puragen, HA hydrogels were prepared by direct amide bond formation between the carboxyl groups of HA and hexamethylenediamine (HMDA) with an optimized carboxyl group modification for effective tissue augmentation. The HA-HMDA hydrogels could be prepared within 5 min by the addition of HMDA to HA solution activated with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and 1-hydroxybenzotriazole monohydrate (HOBt). Five kinds of samples, a normal control, a negative control, a positive control of Restylane, adipic acid dihydrazide grafted HA (HA-ADH) hydrogels, and HA-HMDA hydrogels, were subcutaneously injected to wrinkled model mice. According to the image analysis on dorsal skin augmentation, the HA-HMDA hydrogels exhibited the best tissue augmentation effect being stable longer than 3 months. Furthermore, histological analyses after hematoxylin-eosin (H&E) and Masson's trichrome staining revealed the excellent biocompatibility and safety of HA-HMDA hydrogels. The dermal thickness and the dermal collagen density in wrinkled mice after treatment with HA-HMDA hydrogels for 12 weeks were comparable to those of normal mice. Compared with HA-DVS hydrogels and Restylane, the excellent tissue augmentation by HA-HMDA hydrogels might be ascribed to the biocompatible residues of amine groups in the cross-linker of HMDA. The HA-HMDA hydrogels will be investigated further as a novel dermal filler for clinical applications. PMID:20078098

  3. Pore size effect of collagen scaffolds on cartilage regeneration.

    PubMed

    Zhang, Qin; Lu, Hongxu; Kawazoe, Naoki; Chen, Guoping

    2014-05-01

    Scaffold pore size is an important factor affecting tissue regeneration efficiency. The effect of pore size on cartilage tissue regeneration was compared by using four types of collagen porous scaffolds with different pore sizes. The collagen porous scaffolds were prepared by using pre-prepared ice particulates that had diameters of 150-250, 250-355, 355-425 and 425-500μm. All the scaffolds had spherical large pores with good interconnectivity and high porosity that facilitated cell seeding and spatial cell distribution. Chondrocytes adhered to the walls of the spherical pores and showed a homogeneous distribution throughout the scaffolds. The in vivo implantation results indicated that the pore size did not exhibit any obvious effect on cell proliferation but exhibited different effects on cartilage regeneration. The collagen porous scaffolds prepared with ice particulates 150-250μm in size best promoted the expression and production of type II collagen and aggrecan, increasing the formation and the mechanical properties of the cartilage.

  4. Acellular Dermal Matrix as a Core Strut for Projection in Nipple Reconstruction: Approaches for Three Different Methods of Breast Reconstruction

    PubMed Central

    Park, Gui-Yong; Cho, Hee-Eun; Lee, Byung-Il; Park, Seung-Ha

    2016-01-01

    Background The objective of this paper was to describe a novel technique for improving the maintenance of nipple projection in primary nipple reconstruction by using acellular dermal matrix as a strut in one of three different configurations, according to the method of prior breast reconstruction. The struts were designed to best fill the different types of dead spaces in nipple reconstruction depending on the breast reconstruction method. Methods A total of 50 primary nipple reconstructions were performed between May 2012 and May 2015. The prior breast reconstruction methods were latissimus dorsi (LD) flap (28 cases), transverse rectus abdominis myocutaneous (TRAM) flap (10 cases), or tissue expander/implant (12 cases). The nipple reconstruction technique involved the use of local flaps, including the C-V flap or star flap. A 1×2-cm acellular dermal matrix was placed into the core with O-, I-, and L-shaped struts for prior LD, TRAM, and expander/implant methods, respectively. The projection of the reconstructed nipple was measured at the time of surgery and at 3, 6, and 9 months postoperatively. Results The nine-month average maintenance of nipple projection was 73.0%±9.67% for the LD flap group using an O-strut, 72.0%±11.53% for the TRAM flap group using an I-strut, and 69.0%±10.82% for the tissue expander/implant group using an L-strut. There were no cases of infection, wound dehiscence, or flap necrosis. Conclusions The application of an acellular dermal matrix with a different kind of strut for each of 3 breast reconstruction methods is an effective addition to current techniques for improving the maintenance of long-term projection in primary nipple reconstruction. PMID:27689049

  5. Acellular Dermal Matrix as a Core Strut for Projection in Nipple Reconstruction: Approaches for Three Different Methods of Breast Reconstruction

    PubMed Central

    Park, Gui-Yong; Cho, Hee-Eun; Lee, Byung-Il; Park, Seung-Ha

    2016-01-01

    Background The objective of this paper was to describe a novel technique for improving the maintenance of nipple projection in primary nipple reconstruction by using acellular dermal matrix as a strut in one of three different configurations, according to the method of prior breast reconstruction. The struts were designed to best fill the different types of dead spaces in nipple reconstruction depending on the breast reconstruction method. Methods A total of 50 primary nipple reconstructions were performed between May 2012 and May 2015. The prior breast reconstruction methods were latissimus dorsi (LD) flap (28 cases), transverse rectus abdominis myocutaneous (TRAM) flap (10 cases), or tissue expander/implant (12 cases). The nipple reconstruction technique involved the use of local flaps, including the C-V flap or star flap. A 1×2-cm acellular dermal matrix was placed into the core with O-, I-, and L-shaped struts for prior LD, TRAM, and expander/implant methods, respectively. The projection of the reconstructed nipple was measured at the time of surgery and at 3, 6, and 9 months postoperatively. Results The nine-month average maintenance of nipple projection was 73.0%±9.67% for the LD flap group using an O-strut, 72.0%±11.53% for the TRAM flap group using an I-strut, and 69.0%±10.82% for the tissue expander/implant group using an L-strut. There were no cases of infection, wound dehiscence, or flap necrosis. Conclusions The application of an acellular dermal matrix with a different kind of strut for each of 3 breast reconstruction methods is an effective addition to current techniques for improving the maintenance of long-term projection in primary nipple reconstruction.

  6. Could aging human skin use a connective tissue growth factor boost to increase collagen content?

    PubMed

    Oliver, Noelynn; Sternlicht, Mark; Gerritsen, Karin; Goldschmeding, Roel

    2010-02-01

    The roles of connective tissue growth factor (CTGF) and transforming growth factor-beta (TGF-beta), both well-known collagen production stimulators, were examined in skin aging. Aged skin and fibroblasts exhibited a coordinate decrease in CTGF, TGF-beta, and type I procollagen expression and content. CTGF knockdown and TGF-beta blockade in normal dermal fibroblasts reduced procollagen expression, whereas overexpressing CTGF increased procollagen by a TGF-beta/Smad signaling-dependent mechanism without involving Smad2/3.

  7. Characterization of collagenous meshworks by volume exclusion of dextrans.

    PubMed Central

    Bert, J L; Pearce, R H; Mathieson, J M; Warner, S J

    1980-01-01

    The volumes from which 3H-labelled dextrans are excluded by dermal collagenous fibres were calculated by dilution of dextran probes. Five dextrans, of average Stokes' radii 1.72, 2.53, 3.92, 4.54 and 14.24nm, were investigated at concentrations between 0.1 and 3% (w/w). The excluded volume was dependent on dextran concentration only for the two smaller probes. The largest dextran was shown not to bind to the fibres. A plot of the square root of excluded volume against Stokes' radius was linear for the four smallest dextrans, corresponding to the predictions of Ogston's [(1958) Trans. Faraday Soc. 54, 1754--1757] rod-and-sphere model of fibrous exclusion, and suggesting that dextrans of Stokes' radius between 1.72 and 4.54 nm were excluded by a cylindrical solid fibre of radius 2.90 +/- 0.72 nm. Larger molecules were excluded by a structure of much greater size, since the volume exclusion for the largest dextran was only slightly greater than that of the dextran less than one-third its radius. The excluded volume of 3H2O fell slightly below the line describing the dextran data, indicating that water had access to most of the volume not occupied by the collagenous fibres. PMID:6169339

  8. Experimental evaluation of the net "Dallop" covered with collagen as the dural substitute.

    PubMed

    Harat, M; Radek, A; Koktysz, R; Kulig, A

    1989-01-01

    Evaluation of the usefulness of the net "Dallop" produced by Tricomed Lódź covered with collagen to the dural defects reparation was analysed. This new original product of Lódź Technical University was compared with widely used in neurosurgery "Zenoderm" produced by Ethicon and "Duratexol" produced by Czechoslovakia. The trial was conducted on 38 rabbits: 4 as a control group (just an original dura sutured after incision with Mersilk Ethicon sutures), 19 with implanted the net "Dallop" covered with collagen, 11 with the "Zenoderm" and 4 with the "Duratexol". Animals were sacrificed after 3, 14, 30 or 90 days after surgery. There were no significant differences between all analysed groups in clinical, macroscopical and morphological investigations. No negative local reactions in histopathological evaluation of the net "Dallop" covered with collagen were observed. The results of our investigations show that the net "Dallop" covered with collagen seems to be the "Zenoderm" and the "Duratexol" dural substitute.

  9. DREAM: a method for semi-quantitative dermal exposure assessment.

    PubMed

    Van-Wendel-de-Joode, Berna; Brouwer, Derk H; Vermeulen, Roel; Van Hemmen, Joop J; Heederik, Dick; Kromhout, Hans

    2003-01-01

    This paper describes a new method (DREAM) for structured, semi-quantitative dermal exposure assessment for chemical or biological agents that can be used in occupational hygiene or epidemiology. It is anticipated that DREAM could serve as an initial assessment of dermal exposure, amongst others, resulting in a ranking of tasks and subsequently jobs. DREAM consists of an inventory and evaluation part. Two examples of dermal exposure of workers of a car-construction company show that DREAM characterizes tasks and gives insight into exposure mechanisms, forming a basis for systematic exposure reduction. DREAM supplies estimates for exposure levels on the outside clothing layer as well as on skin, and provides insight into the distribution of dermal exposure over the body. Together with the ranking of tasks and people, this provides information for measurement strategies and helps to determine who, where and what to measure. In addition to dermal exposure assessment, the systematic description of dermal exposure pathways helps to prioritize and determine most adequate measurement strategies and methods. DREAM could be a promising approach for structured, semi-quantitative, dermal exposure assessment. PMID:12505908

  10. Dermal exposure to environmental contaminants in the Great Lakes.

    PubMed Central

    Moody, R P; Chu, I

    1995-01-01

    This paper reviews the literature to determine the importance of the dermal route of exposure for swimmers and bathers using Great Lakes waters and summarizes the chemical water contaminants of concern in the Great Lakes along with relevant dermal absorption data. We detail in vivo and in vitro methods of quantifying the degree of dermal absorption and discuss a preference for infinite dose data as opposed to finite dose data. The basic mechanisms of the dermal absorption process, routes of chemical entry, and the environmental and physiological factors affecting this process are also reviewed, and we discuss the concepts of surface slick exposure to lipophilic compounds and the adsorption of contaminants to water sediment. After presenting mathematical constructs for calculating the degree of exposure, we present in vitro data concerning skin absorption of polyaromatic hydrocarbons adsorbed to Great Lakes water sediment to show that in a worst-case scenario exposure via the dermal route can be equally important to the oral route. We have concluded that prolonged exposure of the skin, especially under conditions that may enhance dermal absorption (e.g., sunburn) may result in toxicologically significant amounts of certain water contaminants being absorbed. It is recommended that swimming should be confined to public beaches, people should refrain from swimming if they are sunburned, and skin should be washed with soap as soon as possible following exposure. Future studies should be conducted to investigate the importance of the dermal exposure route to swimmers and bathers. PMID:8635434

  11. Evaluation of systemic and dermal toxicity and dermal photoprotection by sour cherry kernels.

    PubMed

    Bak, Istvan; Czompa, Attila; Csepanyi, Evelin; Juhasz, Bela; Kalantari, Heibatullah; Najm, Khadija; Aghel, Nasreen; Varga, Balazs; Haines, David D; Tosaki, Arpad

    2011-11-01

    The present report describes outcomes of animal studies conducted to determine the systemic and dermal toxicity of Prunus cerasus (sour cherry) seed kernel contents; and a separate evaluation of the photoprotective capacity of the kernel oil fraction. B6 mice and Hartley guinea-pigs were used for these experiments. Dosage groups of 6-8 animals were administered whole kernel meal in a dose range of 0-3000 mg/kg by gavage for 8 days, following which they were killed. The liver and kidney weights were recorded and histological examination performed on sections of these organs. Kidney function was assessed as blood urea nitrogen and creatinine and liver function by measurement of serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and alkaline phosphatase. Dermal toxicity was evaluated in a Hartley guinea-pig model by comparing UVB-irradiated shaved skin to which the kernel oil had been applied with distilled water controls. In conclusion, no evidence of toxicity was observed to result from the consumption or dermal application of sour cherry seed kernel in the dose range at which it is likely to be used in foods or healthcare. Moreover, it was shown to have a powerful capacity to protect skin from UV damage. These results suggest it will prove to be a highly safe and effective addition to a wide range of products for general use. PMID:21751269

  12. Dermal and Ophthalmic Findings in Pseudohypoaldosteronism

    PubMed Central

    Korkut, Sabriye; Gökalp, Emir; Özdemir, Ahmet; Kurtoğlu, Selim; Demirtaş, Şafak; Gül, Ülkü; Baştuğ, Osman

    2015-01-01

    Pseudohypoaldosteronism (PHA) is defined as a state of resistance to aldosterone, a hormone crucial for electrolyte equilibrium. The genetically transmitted type of PHA is primary hypoaldosteronism. Secondary hypoaldosteronism develops as a result of hydronephrosis or hydroureter. PHA patients suffer from severe hyponatremia and a severe clinical condition due to severe loss of salt can be encountered in the neonatal period. Dermal findings in the form of miliaria rubra can also develop in these patients. With the loss of salt, abnormal accumulation of sebum in the eye due to a defect in the sodium channels can also occur. In this paper, a case of PHA in a newborn showing typical dermatological and ophthalmological findings is presented. PMID:26316441

  13. Closure of the abdominal wall with acellular dermal allograft in intestinal transplantation.

    PubMed

    Mangus, R S; Kubal, C A; Tector, A J; Fridell, J A; Klingler, K; Vianna, R M

    2012-12-01

    Loss of abdominal domain is a common problem in intestinal transplantation. Several surgical options are available perioperatively for abdominal wall reconstruction. This study reports the management and complications for intestinal transplant patients with abdominal wall closure either primarily or with foreign material. This single center study reviews the records of intestinal transplant patients between 2004 and 2010. Study outcomes included reoperation for dehiscence, hernia or enterocutaneous fistula. There were 37 of 146 patients (25%) who required implantation of foreign material at transplant. Of these 37, 30 (81%) had implantation of acellular dermal allograft (ADA) and 7 (19%) implantation of another mesh. Perioperative dehiscence was rare with 2/109 (2%) for primary closure, 0/30 (0%) for ADA and 1/7 (14%) for other mesh. There were 12/146 (8%) patients who underwent ventral hernia repair: primary closure 7/109 (6%), ADA 3/30 (10%) and other mesh 2/7 (28%). There were 4/146 (3%) patients who required surgery for enterocutaneous fistulas: 2/109 (2%) primary closure, 1/30 (3%) ADA and 1/7 (14%) synthetic mesh. Abdominal wall reconstruction with ADA biologic mesh provides an expeditious means of performing a tension-free closure of the fascial layer after intestinal transplantation with complications similar to those seen for primary closure.

  14. [Generalized granuloma annulare or diffuse dermal histiocytosis?].

    PubMed

    Kretzschmar, L; Biel, K; Luger, T A; Goerdt, S

    1995-08-01

    Generalized granuloma annulare is a rare variant of granuloma annulare affecting the trunk and extremities with a multitude of lesions. In contrast to localized granuloma annulare, generalized granuloma annulare occurs in older patients, shows a stronger association with diabetes, and is characteristically chronic. Like our 55-year-old patient, most patients present with papules and annular plaques; less often, macular or non-annular lesions may be encountered. Histology often fails to show necrobiotic or necrotic connective tissue changes demarcated by a palisading granuloma. Instead, there are diffuse dermal, band-like or nodular aggregations of histiocytes intermingled with some multinucleated giant cells and a predominantly lymphocytic infiltrate in the periphery. Because of its special characteristics, it has been suggested that generalized granuloma annulare might constitute a separate disease entity and that it should be classed among the primary cutaneous histiocytoses as a diffuse dermal histiocytosis. Using immunohistochemistry to determine the macrophage phenotype of the lesional histiocytes, we have shown that generalized granuloma annulare is not a cutaneous histiocytosis. Neither MS-1 high-molecular-weight protein, a new specific marker for cutaneous non-Langerhans cell histiocytoses, nor CD1a, the well-known marker for Langerhans cells and Langerhans cell histiocytoses, is expressed by the lesional histiocytes of our patient. In contrast, the antigen expression pattern was diagnostic for non-infectious granulomas and was highly similar to that in localized granuloma annulare. In contrast to the successful treatment of localized granuloma annulare reported with intralesional interferon beta-1, systemic treatment with interferon alpha-2b (9 x 10(6) units three times a week) was ineffective.

  15. Responses of dermal mast cells to injury.

    PubMed Central

    el Sayed, S O; Dyson, M

    1993-01-01

    The effect on dermal mast cell numbers and degranulation of making a partial thickness skin wound on the right flank of Wistar rats was studied immediately after operation and 0.5, 1, 2, 4, 8, 16, 24 and 72 h postoperatively. An equivalent area of intact dermis on the left flank was used as a control. In the injured dermis the mean number of detectable mast cells in the experimental group immediately after making the partial thickness wound was not significantly different from the control side (P > 0.25) but it later decreased, reaching its lowest value after 2 h and increasing from 16 h to 72 h postoperatively when the final assessment was made. The possibility that the reduction in mast cell number per unit area might be an artefact resulting from increased tissue volume due to oedema was investigated and disproved. The total number of dermal mast cells in equivalent areas of the intact left flank remained unchanged throughout this period. The percentage of degranulating mast cells started rising 0.5 h postoperatively, increased gradually to reach its highest value after 2 h, remained high up to 8 h postoperatively and then decreased to reach its lowest value after 72 h. The percentage of degranulating mast cells of the intact dermis of the left flank did not alter during this period. The lack of a significant change in the control groups shows either the absence of any systemic effect or that the technique used was not sensitive enough to detect it. Images Fig. 1 Fig. 2 Fig. 3 PMID:8226292

  16. Silk electrogel coatings for titanium dental implants.

    PubMed

    Elia, Roberto; Michelson, Courtney D; Perera, Austin L; Harsono, Masly; Leisk, Gray G; Kugel, Gerard; Kaplan, David L

    2015-04-01

    The aim of this study was to develop biocompatible, biodegradable dental implant coatings capable of withstanding the mechanical stresses imparted during implant placement. Two techniques were developed to deposit uniform silk fibroin protein coatings onto dental implants. Two novel coating techniques were implemented to coat titanium shims, studs, and implants. One technique involved electrodeposition of the silk directly onto the titanium substrates. The second technique consisted of melting electrogels and dispensing the melted gels onto the titanium to form the coatings. Both techniques were tested for coating reproducibility using a stylus profilometer and a dial thickness gauge. The mechanical strength of adhered titanium studs was assessed using a universal mechanical testing machine. Uniform, controllable coatings were obtained from both the electrodeposition and melted electrogel coating techniques, tunable from 35 to 1654 µm thick under the conditions studied, and able to withstand delamination during implantation into implant socket mimics. Mechanical testing revealed that the adhesive strength of electrogel coatings, 0.369 ± 0.09 MPa, rivaled other biologically derived coating systems such as collagen, hydroxyapatite, and chitosan (0.07-4.83 MPa). These novel silk-based techniques offer a unique approach to the deposition of safe, simple, mechanically robust, biocompatible, and degradable implant coatings.

  17. Repair of patellar tendon injuries using a cell-collagen composite.

    PubMed

    Awad, Hani A; Boivin, Gregory P; Dressler, Matthew R; Smith, Frost N L; Young, Randell G; Butler, David L

    2003-05-01

    Collagen gels were seeded with rabbit bone marrow-derived mesenchymal stem cells (MSCs) and contracted onto sutures at initial cell densities of 1, 4, and 8 million cells/ml. These MSC-collagen composites were then implanted into full thickness, full length, central defects created in the patellar tendons of the animals providing the cells. These autologous repairs were compared to natural repair of identical defects on the contralateral side. Biomechanical, histological, and morphometric analyses were performed on both repair tissue types at 6, 12, and 26 weeks after surgery. Repair tissues containing the MSC-collagen composites showed significantly higher maximum stresses and moduli than natural repair tissues at 12 and 26 weeks postsurgery. However, no significant differences were observed in any dimensional or mechanical properties of the repair tissues across seeding densities at each evaluation time. By 26 weeks, the repairs grafted with MSC-collagen composites were one-fourth of the maximum stress of the normal central portion of the patellar tendon with bone ends. The modulus and maximum stress of the repair tissues grafted with MSC-collagen composites increased at significantly faster rates than did natural repairs over time. Unexpectedly, 28% of the MSC-collagen grafted tendons formed bone in the regenerating repair site. Except for increased repair tissue volume, no significant differences in cellular organization or histological appearance were observed between the natural repairs and MSC-collagen grafted repairs. Overall, these results show that surgically implanting tissue engineered MSC-collagen composites significantly improves the biomechanical properties of tendon repair tissues, although greater MSC concentrations produced no additional significant histological or biomechanical improvement.

  18. Global remodelling of cellular microenvironment due to loss of collagen VII

    PubMed Central

    Küttner, Victoria; Mack, Claudia; Rigbolt, Kristoffer TG; Kern, Johannes S; Schilling, Oliver; Busch, Hauke; Bruckner-Tuderman, Leena; Dengjel, Jörn

    2013-01-01

    The mammalian cellular microenvironment is shaped by soluble factors and structural components, the extracellular matrix, providing physical support, regulating adhesion and signalling. A global, quantitative mass spectrometry strategy, combined with bioinformatics data processing, was developed to assess proteome differences in the microenvironment of primary human fibroblasts. We studied secreted proteins of fibroblasts from normal and pathologically altered skin and their post-translational modifications. The influence of collagen VII, an important structural component, which is lost in genetic skin fragility, was used as model. Loss of collagen VII had a global impact on the cellular microenvironment and was associated with proteome alterations highly relevant for disease pathogenesis including decrease in basement membrane components, increase in dermal matrix proteins, TGF-β and metalloproteases, but not higher protease activity. The definition of the proteome of fibroblast microenvironment and its plasticity in health and disease identified novel disease mechanisms and potential targets of intervention. PMID:23591773

  19. Synthesis of highly interconnected 3D scaffold from Arothron stellatus skin collagen for tissue engineering application.

    PubMed

    Ramanathan, Giriprasath; Singaravelu, Sivakumar; Raja, M D; Sivagnanam, Uma Tiruchirapalli

    2015-11-01

    The substrate which is avidly used for tissue engineering applications should have good mechanical and biocompatible properties, and all these parameters are often considered as essential for dermal reformation. Highly interconnected three dimensional (3D) wound dressing material with enhanced structural integrity was synthesized from Arothron stellatus fish skin (AsFS) collagen for tissue engineering applications. The synthesized 3D collagen sponge (COL-SPG) was further characterized by different physicochemical methods. The scanning electron microscopy analysis of the material demonstrated that well interconnected pores with homogeneous microstructure on the surface aids higher swelling index and that the material also possessed good mechanical properties with a Young's modulus of 0.89±0.2 MPa. Biocompatibility of the 3D COL-SPG showed 92% growth for both NIH 3T3 fibroblasts and keratinocytes. Overall, the study revealed that synthesized 3D COL-SPG from fish skin will act as a promising wound dressing in skin tissue engineering.

  20. Childhood Epidermolysis Bullosa Acquisita: Confirmation of Diagnosis by Skin Deficient in Type VII Collagen, Enzyme-linked Immunosorbent Assay, and Immunoblotting.

    PubMed

    Goyal, Nupur; Rao, Raghavendra; Balachandran, C; Pai, Sathish; Bhogal, Balbir S; Schmidt, Enno; Zillikens, Detlef

    2016-01-01

    Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disorder characterized by autoantibodies against Type VII collagen. It usually affects adults; childhood EBA is rare. We describe a 10-year-old girl presenting with recurrent tense blisters predominantly on legs, dorsa of hands and feet accompanied by oral erosions since the age of 5 years. Direct immunofluorescence (IF) microscopy showed linear deposition of IgG and C3 along the basement membrane zone (BMZ); indirect IF microscopy on salt-split skin revealed staining of IgG to the dermal side of the split. The patient's serum did not show BMZ staining in recessive dystrophic epidermolysis bullosa skin deficient for Type VII collagen, thus confirming autoantibody reactivity against Type VII collagen. Circulating antibodies against the immunodominant noncollagenous 1 domain of Type VII collagen were detected by ELISA and immunoblotting studies. The patient was treated with oral corticosteroids and dapsone with good improvement. PMID:27293257

  1. Childhood Epidermolysis Bullosa Acquisita: Confirmation of Diagnosis by Skin Deficient in Type VII Collagen, Enzyme-linked Immunosorbent Assay, and Immunoblotting

    PubMed Central

    Goyal, Nupur; Rao, Raghavendra; Balachandran, C; Pai, Sathish; Bhogal, Balbir S; Schmidt, Enno; Zillikens, Detlef

    2016-01-01

    Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disorder characterized by autoantibodies against Type VII collagen. It usually affects adults; childhood EBA is rare. We describe a 10-year-old girl presenting with recurrent tense blisters predominantly on legs, dorsa of hands and feet accompanied by oral erosions since the age of 5 years. Direct immunofluorescence (IF) microscopy showed linear deposition of IgG and C3 along the basement membrane zone (BMZ); indirect IF microscopy on salt-split skin revealed staining of IgG to the dermal side of the split. The patient's serum did not show BMZ staining in recessive dystrophic epidermolysis bullosa skin deficient for Type VII collagen, thus confirming autoantibody reactivity against Type VII collagen. Circulating antibodies against the immunodominant noncollagenous 1 domain of Type VII collagen were detected by ELISA and immunoblotting studies. The patient was treated with oral corticosteroids and dapsone with good improvement. PMID:27293257

  2. [Analysis on the dermal irritation caused by imported cosmetics].

    PubMed

    Xing, S; Yuan, L; Song, R; Xu, F

    2001-11-01

    Dermal irritation tests on 902 kinds of cosmetics were conducted. The acute dermal irritation/corrosion tests for 175 samples showed no irritation in 65.1% of them, and 34.9% of them were considered as slight irritation. The chronic dermal irritation/corrosion tests for another 727 samples showed no irritation for 32.2% of them, and 67.8% of them were considered as slight irritation, most of which are lipsticks, eye shadows, fluid powder foundations and powder foundations.

  3. Brain abscess as a manifestation of spinal dermal sinus

    PubMed Central

    Emami-Naeini, Parisa; Mahdavi, Ali; Ahmadi, Hamed; Baradaran, Nima; Nejat, Farideh

    2008-01-01

    Dermal sinuses have been associated with a wide spectrum of clinical manifestations ranging from asymptomatic to drainage of purulent material from the sinus tract, inclusion tumors, meningitis, and spinal abscess. To date, there has been no documented report of brain abscess as a complication of spinal dermal sinus. Here, we report an 8-month-old girl who was presented initially with a brain abscess at early infancy but lumbar dermal sinus and associated spinal abscess were discovered afterwards. The probable mechanisms of this rare association have been discussed. PMID:19209295

  4. The influence of vapor pressure of chemicals on dermal penetration.

    PubMed

    Gilpin, Sarah

    2014-01-01

    Dermal exposure is an important route of entry for chemicals in occupational and consumer settings. Key to this exposure is the penetration of the skin's barrier, and key to this penetration is a chemical's vapor pressure. Until now, vapor pressure and its effects on the skin have yet to be widely studied. This review aims to provide some historical background on early work on dermal penetration for volatile materials, which has helped form later research into the effects of vapor pressure on chemical risk assessment for dermal exposures. This review should be the start of an investigation into more in-depth coverage of vapor pressure and current prediction models.

  5. Nonlinear microscopy of collagen fibers

    NASA Astrophysics Data System (ADS)

    Strupler, M.; Pena, A.-M.; Hernest, M.; Tharaux, P.-L.; Fabre, A.; Marchal-Somme, J.; Crestani, B.; Débarre, D.; Martin, J.-L.; Beaurepaire, E.; Schanne-Klein, M.-C.

    2007-02-01

    We used intrinsic Second Harmonic Generation (SHG) by fibrillar collagen to visualize the three-dimensional architecture of collagen fibrosis at the micrometer scale using laser scanning nonlinear microscopy. We showed that SHG signals are highly specific to fibrillar collagen and provide a sensitive probe of the micrometer-scale structural organization of collagen in tissues. Moreover, recording simultaneously other nonlinear optical signals in a multimodal setup, we visualized the tissue morphology using Two-Photon Excited Fluorescence (2PEF) signals from endogenous chromophores such as NADH or elastin. We then compared different methods to determine accurate indexes of collagen fibrosis using nonlinear microscopy, given that most collagen fibrils are smaller than the microscope resolution and that second harmonic generation is a coherent process. In order to define a robust method to process our three-dimensional images, we either calculated the fraction of the images occupied by a significant SHG signal, or averaged SHG signal intensities. We showed that these scores provide an estimation of the extension of renal and pulmonary fibrosis in murine models, and that they clearly sort out the fibrotic mice.

  6. Analysis of human collagen sequences.

    PubMed

    Nassa, Manisha; Anand, Pracheta; Jain, Aditi; Chhabra, Aastha; Jaiswal, Astha; Malhotra, Umang; Rani, Vibha

    2012-01-01

    The extracellular matrix is fast emerging as important component mediating cell-cell interactions, along with its established role as a scaffold for cell support. Collagen, being the principal component of extracellular matrix, has been implicated in a number of pathological conditions. However, collagens are complex protein structures belonging to a large family consisting of 28 members in humans; hence, there exists a lack of in depth information about their structural features. Annotating and appreciating the functions of these proteins is possible with the help of the numerous biocomputational tools that are currently available. This study reports a comparative analysis and characterization of the alpha-1 chain of human collagen sequences. Physico-chemical, secondary structural, functional and phylogenetic classification was carried out, based on which, collagens 12, 14 and 20, which belong to the FACIT collagen family, have been identified as potential players in diseased conditions, owing to certain atypical properties such as very high aliphatic index, low percentage of glycine and proline residues and their proximity in evolutionary history. These collagen molecules might be important candidates to be investigated further for their role in skeletal disorders. PMID:22359431

  7. Human collagen produced in plants

    PubMed Central

    Shoseyov, Oded; Posen, Yehudit; Grynspan, Frida

    2014-01-01

    Consequential to its essential role as a mechanical support and affinity regulator in extracellular matrices, collagen constitutes a highly sought after scaffolding material for regeneration and healing applications. However, substantiated concerns have been raised with regard to quality and safety of animal tissue-extracted collagen, particularly in relation to its immunogenicity, risk of disease transmission and overall quality and consistency. In parallel, contamination with undesirable cellular factors can significantly impair its bioactivity, vis-a-vis its impact on cell recruitment, proliferation and differentiation. High-scale production of recombinant human collagen Type I (rhCOL1) in the tobacco plant provides a source of an homogenic, heterotrimeric, thermally stable “virgin” collagen which self assembles to fine homogenous fibrils displaying intact binding sites and has been applied to form numerous functional scaffolds for tissue engineering and regenerative medicine. In addition, rhCOL1 can form liquid crystal structures, yielding a well-organized and mechanically strong membrane, two properties indispensable to extracellular matrix (ECM) mimicry. Overall, the shortcomings of animal- and cadaver-derived collagens arising from their source diversity and recycled nature are fully overcome in the plant setting, constituting a collagen source ideal for tissue engineering and regenerative medicine applications. PMID:23941988

  8. Characterisations of collagen-silver-hydroxyapatite nanocomposites

    NASA Astrophysics Data System (ADS)

    Ciobanu, C. S.; Popa, C. L.; Petre, C. C.; Jiga, G.; Trusca, R.; Predoi, D.

    2016-05-01

    The XRD analysis were performed to confirm the formation of hydroxyapatite structure in collagen-silver-hydroxyapatite nanocomposites. The molecular interaction in collagen-hydroxyapatite nanocomposites was highlighted by Fourier transform infrared spectroscopy (FTIR) analysis. The SEM showed a nanostructure of collagen-silverhydroxyapatite nanocomposites composed of nano needle-like particles in a veil with collagen texture. The presence of vibrational groups characteristics to the hydroxyapatite structure in collagen-silver-hydroxyapatite (AgHApColl) nanocomposites was investigated by FTIR.

  9. A biomaterial composed of collagen and solubilized elastin enhances angiogenesis and elastic fiber formation without calcification.

    PubMed

    Daamen, Willeke F; Nillesen, Suzan T M; Wismans, Ronnie G; Reinhardt, Dieter P; Hafmans, Theo; Veerkamp, Jacques H; van Kuppevelt, Toin H

    2008-03-01

    Elastin is the prime protein in elastic tissues that contributes to elasticity of, for example, lung, aorta, and skin. Upon injury, elastic fibers are not readily replaced, which hampers tissue regeneration. Incorporation of solubilized elastin (hydrolyzed insoluble elastin fibers or elastin peptides) in biomaterials may improve regeneration, because solubilized elastin is able to promote proliferation as well as elastin synthesis. Porous biomaterials composed of highly purified collagen without and without elastin fibers or solubilized elastin were prepared by freezing and lyophilization. Solubilized elastin formed spherical structures that were incorporated in the collagenous part of the scaffolds and that persisted after chemical crosslinking of the scaffolds. Crosslinked scaffolds were subcutaneously implanted in young Sprague Dawley rats. Collagen-solubilized elastin and collagen scaffolds showed no calcification in this sensitive calcification model, in contrast to scaffolds containing elastin fibers. Collagen-solubilized elastin scaffolds also induced angiogenesis, as revealed by type IV collagen staining, and promoted elastic fiber synthesis, as shown with antibodies against rat elastin and fibrillin-1. It is concluded that scaffolds produced from collagen and solubilized elastin present a non-calcifying biomaterial with a capacity for soft-tissue regeneration, especially in relation to elastic fiber synthesis.

  10. Collagen XVII and BPAG1 Expression in the Retina: Evidence for an Anchoring Complex in the Central Nervous System

    PubMed Central

    Claudepierre, Thomas; Manglapus, Mary K.; Marengi, Nathan; Radner, Stephanie; Champliaud, Marie-France; Tasanen, Kaisa; Bruckner-Tuderman, Leena; Hunter, Dale D.; Brunken, William J.

    2010-01-01

    The ectoderm gives rise not only to the skin but also to the entire CNS. This common embryonic lineage suggests that some molecular isoforms might serve analogous functions in both tissues. Indeed, not only are laminins important components of dermal adhesion mechanisms, but they also regulate some aspects of synaptic development in both the CNS and the PNS. In the skin, laminins are part of a hemidesmosome complex essential for basal keratinocyte adhesion that includes collagen XVII (BP180) and BPAG1 (dystonin/BP230). Here, we show that CNS neurons also express collagen XVII and BPAG1 and that these molecules are expressed in the adult and developing retina. In the retina, isoforms of collagen XVII and BPAG1 are colocalized with laminins at photoreceptor synapses and around photoreceptor outer segments; both molecules are expressed by rods, whereas cones express collagen XVII but not BPAG1. Moreover, biochemical data demonstrate that collagen XVII complexes with retinal laminins. We propose that collagen XVII and BPAG1 isoforms may help to anchor elements of the rod photoreceptor cytomatrix to the extracellular matrix. PMID:15880472

  11. Osteopontin (OPN) is an important protein to mediate improvements in the biocompatibility of C ion-implanted silicone rubber.

    PubMed

    Wang, Shao-liang; Shi, Xiao-hua; Yang, Zhi; Zhang, Yi-ming; Shen, Li-ru; Lei, Ze-yuan; Zhang, Zhi-Qing; Cao, Cong; Fan, Dong-li

    2014-01-01

    Medical device implants are drawing increasing amounts of interest from modern medical practitioners. However, this attention is not evenly spread across all such devices; most of these implantable devices can cause adverse reactions such as inflammation, fibrosis, thrombosis, and infection. In this work, the biocompatibility of silicone rubber (SR) was improved through carbon (C) ion implantation. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results confirmed that these newly generated carbon-implanted silicone rubbers (C-SRs) had large, irregular peaks and deep valleys on their surfaces. The water contact angle of the SR surface decreased significantly after C ion implantation. C ion implantation also changed the surface charge distribution, silicone oxygen rate, and chemical-element distribution of SR to favor cell attachment. The dermal fibroblasts cultured on the surface C-SR grew faster and showed more typical fibroblastic shapes. The expression levels of major adhesion proteins, including talin-1, zyxin, and vinculin, were significantly higher in dermal fibroblasts cultured on C-SR coated plates than in dermal fibroblasts cultured on SR. Those same dermal fibroblasts on C-SRs showed more pronounced adhesion and migration abilities. Osteopontin (OPN), a critical extracellular matrix (ECM) protein, was up-regulated and secreted from dermal fibroblasts cultured on C-SR. Matrix metalloproteinase-9 (MMP-9) activity was also increased. These cells were highly mobile and were able to adhere to surfaces, but these abilities were inhibited by the monoclonal antibody against OPN, or by shRNA-mediated MMP-9 knockdown. Together, these results suggest that C ion implantation significantly improves SR biocompatibility, and that OPN is important to promote cell adhesion to the C-SR surface.

  12. Osteopontin (OPN) Is an Important Protein to Mediate Improvements in the Biocompatibility of C Ion-Implanted Silicone Rubber

    PubMed Central

    Zhang, Yi-ming; Shen, Li-ru; Lei, Ze-yuan; Zhang, Zhi-qing; Cao, Cong; Fan, Dong-li

    2014-01-01

    Medical device implants are drawing increasing amounts of interest from modern medical practitioners. However, this attention is not evenly spread across all such devices; most of these implantable devices can cause adverse reactions such as inflammation, fibrosis, thrombosis, and infection. In this work, the biocompatibility of silicone rubber (SR) was improved through carbon (C) ion implantation. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results confirmed that these newly generated carbon-implanted silicone rubbers (C-SRs) had large, irregular peaks and deep valleys on their surfaces. The water contact angle of the SR surface decreased significantly after C ion implantation. C ion implantation also changed the surface charge distribution, silicone oxygen rate, and chemical-element distribution of SR to favor cell attachment. The dermal fibroblasts cultured on the surface C-SR grew faster and showed more typical fibroblastic shapes. The expression levels of major adhesion proteins, including talin-1, zyxin, and vinculin, were significantly higher in dermal fibroblasts cultured on C-SR coated plates than in dermal fibroblasts cultured on SR. Those same dermal fibroblasts on C-SRs showed more pronounced adhesion and migration abilities. Osteopontin (OPN), a critical extracellular matrix (ECM) protein, was up-regulated and secreted from dermal fibroblasts cultured on C-SR. Matrix metalloproteinase-9 (MMP-9) activity was also increased. These cells were highly mobile and were able to adhere to surfaces, but these abilities were inhibited by the monoclonal antibody against OPN, or by shRNA-mediated MMP-9 knockdown. Together, these results suggest that C ion implantation significantly improves SR biocompatibility, and that OPN is important to promote cell adhesion to the C-SR surface. PMID:24911051

  13. Importance of amino acid composition to improve skin collagen protein synthesis rates in UV-irradiated mice.

    PubMed

    Murakami, Hitoshi; Shimbo, Kazutaka; Inoue, Yoshiko; Takino, Yoshinobu; Kobayashi, Hisamine

    2012-06-01

    Skin collagen metabolism abnormalities induced by ultraviolet (UV) radiation are the major causes of skin photoaging. It has been shown that the one-time exposure of UV irradiation decreases procollagen mRNA expression in dermis and that chronic UV irradiation decreases collagen amounts and induces wrinkle formation. Amino acids are generally known to regulate protein metabolism. Therefore, we investigated the effects of UV irradiation and various orally administered amino acids on skin collagen synthesis rates. Groups of 4-5 male, 8-week-old HR-1 hairless mice were irradiated with UVB (66 mJ/cm2) twice every other day, then fasted for 16 h. The fractional synthesis rate (FSR; %/h) of skin tropocollagen was evaluated by incorporating L-[ring-2H5]-phenylalanine. We confirmed that the FSR of dermal tropocollagen decreased after UVB irradiation. The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice. Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30). However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively). This result suggests that combinations of BCAA and glutamine or proline are important for restoring dermal collagen protein synthesis impaired by UV irradiation.

  14. Corneal epithelialisation on surface-modified hydrogel implants: artificial cornea.

    PubMed

    Ma, Aihua; Zhao, Bojun; Bentley, Adam J; Brahma, Arun; MacNeil, Sheila; Martin, Francis L; Rimmer, Stephen; Fullwood, Nigel J

    2011-03-01

    The objective was to investigate corneal re-epithelialisation of surface-modified polymethacrylate hydrogel implants in order to evaluate them as potential materials for an artificial cornea. Polymethacrylate hydrogels were modified with amines and then coated with different extracellular matrix proteins (collagen I, IV, laminin and fibronectin). The modified hydrogels were surgically implanted into bovine corneas maintained in a 3-D culture system for 5 days. The epithelial growth across the implant surface was evaluated using fluorescent, light and electron microscopy. Full epithelialisation was achieved on 1,4-diaminobutane-modified hydrogels after coating with collagen IV. Hydrogels modified with 1,4-diaminobutane but without further coating only showed partial re-epithelialisation. Hydrogels modified with other amines (1,2-diaminoethane or 1,3-diaminopropane) showed only partial re-epithelialisation; further coating with extracellular matrix proteins improved epithelialisation of these surfaces but did not result in complete re-epithelialisation. Evaluation of the corneas implanted with the 1,4-diaminobutane-modified hydrogels coated with collagen IV showed that the artificial corneas remain clear, integrate well and become covered by a healthy stratified epithelium. In conclusion the 1,4-diaminobutane surface-modified hydrogel coated with collagen IV supported the growth of a stable stratified epithelium. With further refinement this hydrogel has the potential to be used clinically for an artificial cornea. PMID:21287242

  15. High-strength mineralized collagen artificial bone

    NASA Astrophysics Data System (ADS)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  16. Is Sterile Better Than Aseptic? Comparing the Microbiology of Acellular Dermal Matrices

    PubMed Central

    Klein, Gabriel M.; Nasser, Ahmed E.; Phillips, Brett T.; Gersch, Robert P.; Fourman, Mitchell S.; Lilo, Sarit E.; Fritz, Jason R.; Khan, Sami U.; Dagum, Alexander B.

    2016-01-01

    Introduction: Postoperative infections are a major complication associated with tissue-expander-based breast reconstruction. The use of acellular dermal matrix (ADM) in this surgery has been identified as a potential reservoir of infection, prompting the development of sterile ADM. Although aseptic and sterile ADMs have been investigated, no study has focused on the occurrence and clinical outcome of bacterial colonization before implantation. Methods: Samples of aseptic AlloDerm, sterile Ready-To-Use AlloDerm, and AlloMax were taken before implantation. These samples were incubated in Tryptic soy broth overnight before being streaked on Trypticase soy agar, MacConkey agar, and 5% blood agar plates for culture and incubated for 48 hours. Culture results were cross-referenced with patient outcomes for 1 year postoperatively. Results: A total of 92 samples of ADM were collected from 63 patients. There were 15 cases of postoperative surgical site infection (16.3%). Only 1 sample of ADM (AlloMax) showed growth of Escherichia coli, which was likely a result of contamination. That patient did not develop any infectious sequelae. Patient outcomes showed no difference in the incidence of seroma or infection between sterile and aseptic ADMs. Conclusions: This study evaluates the microbiology of acellular dermal matrices before use in breast reconstruction. No difference was found in the preoperative bacterial load of either aseptic or sterile ADM. No significant difference was noted in infection or seroma formation. Given these results, we believe aseptic processing used on ADMs is equivalent to sterile processing in our patient cohort in terms of clinical infection and seroma occurrence postoperatively. PMID:27482500

  17. Cochlear Implants

    MedlinePlus

    ... outside of the body, behind the ear. A second part is surgically placed under the skin. An implant does not restore normal hearing. It can help a person understand speech. Children and adults can benefit from them. National Institute on Deafness and Other Communication Disorders

  18. Facial implants.

    PubMed

    Arcuri, M R; Rubenstein, J T

    1998-01-01

    The application of endosseous dental implants for the retention and stabilization of extraoral prostheses and hearing aids has been shown to be effective functionally and aesthetically. Implants have reduced the need for adhesive use, simplifying cleaning procedures and thus extending the life of the prosthesis. Implant-retained prostheses have provided patients the opportunity to participate in routine activities such as work, shopping, swimming, and jogging with less fear of losing their prosthesis. The implants' impact on patients has resulted in their ability to function in society with confidence that their defects will be less noticeable and their ability to respond to the environment enhanced. The culmination of these effects have without doubt improved the overall quality of life for patients. As with any new technology, its application will encounter unanticipated problems and some limitations in use. As the art and science of this technique evolve, however, it is anticipated that it will result in the ability to provide improved health care for patients.

  19. Implantable electrode for recording nerve signals in awake animals

    NASA Technical Reports Server (NTRS)

    Ninomiya, I.; Yonezawa, Y.; Wilson, M. F.

    1976-01-01

    An implantable electrode assembly consisting of collagen and metallic electrodes was constructed to measure simultaneously neural signals from the intact nerve and bioelectrical noises in awake animals. Mechanical artifacts, due to bodily movement, were negligibly small. The impedance of the collagen electrodes, measured in awake cats 6-7 days after implantation surgery, ranged from 39.8-11.5 k ohms at a frequency range of 20-5 kHz. Aortic nerve activity and renal nerve activity, measured in awake conditions using the collagen electrode, showed grouped activity synchronous with the cardiac cycle. Results indicate that most of the renal nerve activity was from postganglionic sympathetic fibers and was inhibited by the baroceptor reflex in the same cardiac cycle.

  20. Nanomechanics of Type I Collagen.

    PubMed

    Varma, Sameer; Orgel, Joseph P R O; Schieber, Jay D

    2016-07-12

    Type I collagen is the predominant collagen in mature tendons and ligaments, where it gives them their load-bearing mechanical properties. Fibrils of type I collagen are formed by the packing of polypeptide triple helices. Higher-order structures like fibril bundles and fibers are assembled from fibrils in the presence of other collagenous molecules and noncollagenous molecules. Curiously, however, experiments show that fibrils/fibril bundles are less resistant to axial stress compared to their constituent triple helices-the Young's moduli of fibrils/fibril bundles are an order-of-magnitude smaller than the Young's moduli of triple helices. Given the sensitivity of the Young's moduli of triple helices to solvation environment, a plausible explanation is that the packing of triple helices into fibrils perhaps reduces the Young's modulus of an individual triple helix, which results in fibrils having smaller Young's moduli. We find, however, from molecular dynamics and accelerated conformational sampling simulations that the Young's modulus of the buried core of the fibril is of the same order as that of a triple helix in aqueous phase. These simulations, therefore, suggest that the lower Young's moduli of fibrils/fibril bundles cannot be attributed to the specific packing of triple helices in the fibril core. It is not the fibril core that yields initially to axial stress. Rather, it must be the portion of the fibril exposed to the solvent and/or the fibril-fibril interface that bears the initial strain. Overall, this work provides estimates of Young's moduli and persistence lengths at two levels of collagen's structural assembly, which are necessary to quantitatively investigate the response of various biological factors on collagen mechanics, including congenital mutations, posttranslational modifications and ligand binding, and also engineer new collagen-based materials. PMID:27410733

  1. Collagen cross-linking and resorption: effect of glutaraldehyde concentration.

    PubMed

    Roe, S C; Milthorpe, B K; Schindhelm, K

    1990-12-01

    Cross-linked collagen bioprostheses usually are designed to be inert and nonresorbable, resulting in fatigue and wear failure in high-stress environments. Eventual replacement of the implant, although minimizing strength loss during resorption, would result in a graft with reparative ability. Kangaroo tail tendon (KTT) partially cross-linked with glutaraldehyde (GA) was evaluated in vitro for resistance to bacterial collagenase digestion and in vivo for biocompatibility and resorbability in an intramuscular implant assay. Cross-linking was quantified by thermal denaturation studies. Incomplete cross-linking was achieved with concentrations of GA less than 0.1% (w/v). KTT cross-linked in greater than or equal to 0.05% GA were collagenase resistant being incompletely digested after 240 h. Cross-linking of KTT with low concentrations of GA resulted in partial collagenase resistance and slowed resorption. PMID:2126427

  2. Safety and efficacy of composite collagen-silver nanoparticle hydrogels as tissue engineering scaffolds

    NASA Astrophysics Data System (ADS)

    Alarcon, Emilio I.; Udekwu, Klas I.; Noel, Christopher W.; Gagnon, Luke B.-P.; Taylor, Patrick K.; Vulesevic, Branka; Simpson, Madeline J.; Gkotzis, Spyridon; Islam, M. Mirazul; Lee, Chyan-Jang; Richter-Dahlfors, Agneta; Mah, Thien-Fah; Suuronen, Erik J.; Scaiano, Juan C.; Griffith, May

    2015-11-01

    The increasing number of multidrug resistant bacteria has revitalized interest in seeking alternative sources for controlling bacterial infection. Silver nanoparticles (AgNPs), are amongst the most promising candidates due to their wide microbial spectrum of action. In this work, we report on the safety and efficacy of the incorporation of collagen coated AgNPs into collagen hydrogels for tissue engineering. The resulting hybrid materials at [AgNPs] < 0.4 μM retained the mechanical properties and biocompatibility for primary human skin fibroblasts and keratinocytes of collagen hydrogels; they also displayed remarkable anti-infective properties against S. aureus, S. epidermidis, E. coli and P. aeruginosa at considerably lower concentrations than silver nitrate. Further, subcutaneous implants of materials containing 0.2 μM AgNPs in mice showed a reduction in the levels of IL-6 and other inflammation markers (CCL24, sTNFR-2, and TIMP1). Finally, an analysis of silver contents in implanted mice showed that silver accumulation primarily occurred within the tissue surrounding the implant.The increasing number of multidrug resistant bacteria has revitalized interest in seeking alternative sources for controlling bacterial infection. Silver nanoparticles (AgNPs), are amongst the most promising candidates due to their wide microbial spectrum of action. In this work, we report on the safety and efficacy of the incorporation of collagen coated AgNPs into collagen hydrogels for tissue engineering. The resulting hybrid materials at [AgNPs] < 0.4 μM retained the mechanical properties and biocompatibility for primary human skin fibroblasts and keratinocytes of collagen hydrogels; they also displayed remarkable anti-infective properties against S. aureus, S. epidermidis, E. coli and P. aeruginosa at considerably lower concentrations than silver nitrate. Further, subcutaneous implants of materials containing 0.2 μM AgNPs in mice showed a reduction in the levels of IL-6 and

  3. Dermal exposure and urinary 1-hydroxypyrene among asphalt roofing workers

    SciTech Connect

    McClean, M.D.; Rinehart, R.D.; Sapkota, A.; Cavallari, J.M.; Herrick, R.F.

    2007-07-01

    The primary objective of this study was to identify significant determinants of dermal exposure to polycyclic aromatic compounds (PACs) among asphalt roofing workers and use urinary 1-hydroxyprene (1-OHP) measurements to evaluate the effect of dermal exposure on total absorbed dose. The study population included 26 asphalt roofing workers who performed three primary tasks: tearing off old roofs, putting down new roofs, and operating the kettle at ground level. During multiple consecutive work shifts, dermal patch samples were collected from the underside of each worker's wrists and were analyzed for PACs, pyrene, and benzo(a)pyrene (BAP). During the same work week, urine samples were collected at pre-shift, post-shift, and bedtime each day and were analyzed for 1-OHP (205 urine samples). Linear mixed effects models were used to evaluate the dermal measurements for the purpose of identifying important determinants of exposure, and to evaluate urinary 1-OHP measurements for the purpose of identifying important determinants of total absorbed dose. Dermal exposures to PAC, pyrene, and BAP were found to vary significantly by roofing task and by the presence of an old coal tar pitch roof. For each of the three analytes, the adjusted mean dermal exposures associated with tear-off were approximately four times higher than exposures associated with operating the kettle. Exposure to coal tar pitch was associated with a 6-fold increase in PAC exposure, an 8-fold increase in pyrene exposure and a 35-fold increase in BAP exposure. The presence of coal tar pitch was the primary determinant of dermal exposure, particularly for exposure to BAP. However, the task-based differences that were observed while controlling for pitch suggest that exposure to asphalt also contributes to dermal exposures.

  4. Volume correction in the aging hand: role of dermal fillers

    PubMed Central

    Rivkin, Alexander Z

    2016-01-01

    The hands, just like the face, are highly visible parts of the body. They age at a similar rate and demonstrate comparable changes with time, sun damage, and smoking. Loss of volume in the hands exposes underlying tendons, veins, and bony prominences. Rejuvenation of the hands with dermal fillers is a procedure with high patient satisfaction and relatively low risk for complications. This study will review relevant anatomy, injection technique, clinical safety, and efficacy of dermal filler volumization of the aging hand.

  5. Morphological and physiological characteristics of dermal photoreceptors in Lymnaea stagnalis

    PubMed Central

    Takigami, Satoshi; Sunada, Hiroshi; Horikoshi, Tetsuro; Sakakibara, Manabu

    2014-01-01

    Dermal photoreceptors located in the mantle of Lymnaea stagnalis were histologically and physiologically characterized. Our previous study demonstrated that the shadow response from dermal photoreceptors induces the whole-body withdrawal response. Through the interneuron, RPeD11, we detected that the light-off response indirectly originated from a dermal photoreceptor. Previous observations, based on behavioral pharmacology, revealed that cyclic guanosine monophosphate acts as a second messenger in the dermal photoreceptor. Furthermore, gastropods possess dermal photoreceptors containing rhodopsin, as a photopigment, and another photo-sensitive protein, arrestin, responsible for terminating the light response. Thus, we chose three antibodies, anti-cGMP, anti-rhodopsin, and anti-β-arrestin, to identify the dermal photoreceptor molecules in Lymnaea mantle. Extracellular recording, using a suction electrode on the mantle, revealed a light off-response from the right parietal nerve. Overlapping structures, positive against each of the antibodies, were also observed. Numerous round, granular particles of 3–47 μm in diameter with one nucleus were distributed around pneumostome and/or inside the mantle. The cells surrounding the pneumostome area, located 10 μm beneath the surface, tended to have smaller cell soma ranging from 3 to 25 μm in diameter, while cells located in other areas were distributed uniformly inside the mantle, with a larger diameter ranging from 12 to 47 μm. The histological examination using back-filing Lucifer Yellow staining of the right parietal nerve with the three dermal photoreceptor antibodies confirmed that these overlapping-stained structures were dermal photoreceptors in Lymnaea. PMID:27493502

  6. Mesenchymal stem cell-coated sutures enhance collagen depositions in sutured tissues.

    PubMed

    Casado, Javier G; Blazquez, Rebeca; Jorge, Inmaculada; Alvarez, Veronica; Gomez-Mauricio, Guadalupe; Ortega-Muñoz, Mariano; Vazquez, Jesus; Sanchez-Margallo, Francisco M

    2014-01-01

    Sutures are commonly used for surgical procedures and new sutures are being developed to improve wound healing. In the past decade, it has been extensively shown that mesenchymal stem cells (MSCs) have a wound healing potential. To benefit the overall wound healing process, we aimed to analyze the usage of pretreated sutures for improving the implantation of MSCs in the tissues. Our results firstly showed that suture pretreatments with gelatin, poly-L-lysine, and NaOH improved the adhesive strength of MSCs to sutures. These cells remained surrounding the sutured tissue and no significant phenotypic changes were found in those cells cultured onto pretreated sutures. In vivo experiments showed that the implantation of MSCs by suturing increases the collagen content in the sutured tissue. Moreover, proteomics analysis of secreted proteins showed that collagen alpha-1(I) chain was the most abundant collagen found. To our knowledge, this is the first report that aimed to improve the implantation of MSCs in tissue by suture pretreatments. Moreover, in vivo experiments suggest that MSC-coated sutures may enhance wound healing and tissue remodeling through the release of different collagen types being applicable for those patients that tend to have difficulty healing.

  7. Fibronectin coating of collagen modules increases in vivo HUVEC survival and vessel formation in SCID mice.

    PubMed

    Cooper, T P; Sefton, M V

    2011-03-01

    Modular tissue engineering is a novel approach to creating scalable, self-assembling, three-dimensional tissue constructs with inherent vascularization. Under initial methods, the subcutaneous implantation of human umbilical vein endothelial cell (HUVEC)-covered collagen modules in immunocompromised mice resulted in significant host inflammation and limited HUVEC survival. A minimally invasive injection technique was used to minimize surgery-related inflammation, and cell death was attributed to extensive apoptosis within 72 h of implantation. Coating collagen modules with fibronectin (Fn) was shown in vivo to reduce short-term HUVEC TUNEL staining by nearly 40%, while increasing long-term HUVEC survival by 30-45%, relative to collagen modules without fibronectin. Consequently, a ∼100% increase in the number of HUVEC-lined vessels was observed with Fn-coated modules, as compared to collagen-only modules, at 7 and 14 days post-implantation. Furthermore, vessels appeared to be perfused with host erythrocytes by day 7, and vessel maturation and stabilization was evident by day 14.

  8. Enhanced stabilization of collagen by furfural.

    PubMed

    Lakra, Rachita; Kiran, Manikantan Syamala; Usha, Ramamoorthy; Mohan, Ranganathan; Sundaresan, Raja; Korrapati, Purna Sai

    2014-04-01

    Furfural (2-furancarboxaldehyde), a product derived from plant pentosans, has been investigated for its interaction with collagen. Introduction of furfural during fibril formation enhanced the thermal and mechanical stability of collagen. Collagen films treated with furfural exhibited higher denaturation temperature (Td) (p<0.04) and showed a 3-fold increase in Young's modulus (p<0.04) at higher concentration. Furfural and furfural treated collagen films did not have any cytotoxic effect. Rheological characterization showed an increase in shear stress and shear viscosity with increasing shear rate for treated collagen. Circular dichroism (CD) studies indicated that the furfural did not have any impact on triple helical structure of collagen. Scanning electron microscopy (SEM) of furfural treated collagen exhibited small sized porous structure in comparison with untreated collagen. Thus this study provides an alternate ecologically safe crosslinking agent for improving the stability of collagen for biomedical and industrial applications.

  9. Multiscale Analyses of the Bone-implant Interface

    PubMed Central

    Cha, J.Y.; Pereira, M.D.; Smith, A.A.; Houschyar, K.S.; Yin, X.; Mouraret, S.; Brunski, J.B.

    2015-01-01

    Implants placed with high insertion torque (IT) typically exhibit primary stability, which enables early loading. Whether high IT has a negative impact on peri-implant bone health, however, remains to be determined. The purpose of this study was to ascertain how peri-implant bone responds to strains and stresses created when implants are placed with low and high IT. Titanium micro-implants were inserted into murine femurs with low and high IT using torque values that were scaled to approximate those used to place clinically sized implants. Torque created in peri-implant tissues a distribution and magnitude of strains, which were calculated through finite element modeling. Stiffness tests quantified primary and secondary implant stability. At multiple time points, molecular, cellular, and histomorphometric analyses were performed to quantitatively determine the effect of high and low strains on apoptosis, mineralization, resorption, and collagen matrix deposition in peri-implant bone. Preparation of an osteotomy results in a narrow zone of dead and dying osteocytes in peri-implant bone that is not significantly enlarged in response to implants placed with low IT. Placing implants with high IT more than doubles this zone of dead and dying osteocytes. As a result, peri-implant bone develops micro-fractures, bone resorption is increased, and bone formation is decreased. Using high IT to place an implant creates high interfacial stress and strain that are associated with damage to peri-implant bone and therefore should be avoided to best preserve the viability of this tissue. PMID:25628271

  10. Extracellular collagenous spherules in salivary gland tumors. Immunohistochemical analysis of laminin and various types of collagen.

    PubMed

    Skalova, A; Leivo, I

    1992-06-01

    Collagenous spherulosis is a benign breast lesion involving lobular acini and ductules and containing eosinophilic spherules measuring up to 100 microns in diameter. We present an immunohistochemical analysis of similar collagen-rich spherules that are also found in salivary gland tumors. These collagenous spherules contain varying amounts of acidic mucins, elastin, basement membrane proteins including type IV collagen and laminin, and considerable amounts of interstitial collagen types I and III. Types II and VI collagen were not detected in collagenous spherules of salivary gland tumors. The cells surrounding these collagenous spherules expressed muscle actin, S100 protein, vimentin, and cytokeratins 8, 18, and 19, indicating that these cells have myoepithelial characteristics.

  11. Collagen type I-coating of Ti6Al4V promotes adhesion of osteoblasts.

    PubMed

    Geissler, U; Hempel, U; Wolf, C; Scharnweber, D; Worch, H; Wenzel, K

    2000-09-15

    The initial contact of osteoblasts with implant surfaces is an important event for osseointegration of implants. Osseointegration of Ti6Al4V may be improved by precoating of its surface with collagen type I. In this study, the adhesion of rat calvarial osteoblasts to uncoated and collagen type I-coated titanium alloy was investigated over a period of 24 h. Collagen type I-coating accelerates initial adhesion of osteoblasts in the presence of fetal calf serum. One hour after plating, no differences in the percentage of adherent cells between the surfaces investigated were found. Adhesion of osteoblasts to uncoated surfaces was reduced by the GRGDSP peptide by about 70%, whereas adhesion to collagen type I-coated surfaces remained unaffected by treatment of the cells with the peptide. Cell adhesion to coated materials was reduced by about 80% by anti-integrin beta1 antibody. The integrin beta1 antibody did not influence the adhesion to uncoated titanium alloy. The results suggest that osteoblasts adhere to collagen type I-coated materials via integrin beta1 but not by interacting with RGD peptides, whereas adhesion to uncoated titanium alloy is mediated by RGD sequences but not via integrin beta1. Fibronectin does not seem to be involved in the adhesion of osteoblasts to either coated or uncoated titanium alloy. PMID:10880125

  12. High-density collagen gel tubes as a matrix for primary human bladder smooth muscle cells.

    PubMed

    Micol, Lionel A; Ananta, Michael; Engelhardt, Eva-Maria; Mudera, Vivek C; Brown, Robert A; Hubbell, Jeffrey A; Frey, Peter

    2011-02-01

    Tissue-engineered grafts for the urinary tract are being investigated for the potential treatment of several urologic diseases. These grafts, predominantly tubular-shaped, usually require in vitro culture prior to implantation to allow cell engraftment on initially cell-free scaffolds. We have developed a method to produce tubular-shaped collagen scaffolds based on plastic compression. Our approach produces a ready cell-seeded graft that does not need further in vitro culture prior to implantation. The tubular collagen scaffolds were in particular investigated for their structural, mechanical and biological properties. The resulting construct showed an especially high collagen density, and was characterized by favorable mechanical properties assessed by axial extension and radial dilation. Young modulus in particular was greater than non-compressed collagen tubes. Seeding densities affected proliferation rate of primary human bladder smooth muscle cells. An optimal seeding density of 10(6) cells per construct resulted in a 25-fold increase in Alamar blue-based fluorescence after 2 wk in culture. These high-density collagen gel tubes, ready seeded with smooth muscle cells could be further seeded with urothelial cells, drastically shortening the production time of graft for urinary tract regeneration.

  13. Configurational effects of collagen/ALP coatings on enzyme immobilization and surface mineralization

    NASA Astrophysics Data System (ADS)

    Bosco, R.; Leeuwenburgh, S. C. G.; Jansen, J. A.; van den Beucken, J. J. J. P.

    2014-08-01

    The ultimate goal for surface modifications in bone implants is to achieve biologically active surface able to control and trigger specific tissue response. In this study was evaluated the effects of organic compound, derived from extracellular matrix, involved in tissue mineralization. Alkaline phosphatase (ALP) plays a fundamental role in bone mineralization concurrently with collagen, the main organic components of bones. Electrospray deposition (ESD) was used to coat titanium disks with ALP and collagen at room temperature. To verify the synergistic role of ALP and collagen different conformations of coatings (mixed and layered) were obtained and their mineralization capacity was tested in vitro. The mineralization tests indicated the fundamental role of collagen to increase ALP coating retention. Analyses indicated that the coating conformation has a role; in fact the mixed group showed improved ALP retention, enzymatic activity and unique mineralized surface morphology. ESD demonstrated to be a successful method to deposit organic molecules preserving their properties as indicated by the in vitro results. These findings proved the synergistic effect of ALP and collagen in inducing mineralization offering an intriguing coating constituent for medical device that aim to trigger surface mineralization such as bone implants.

  14. 3D Printing of Composite Calcium Phosphate and Collagen Scaffolds for Bone Regeneration

    PubMed Central

    Inzana, Jason A.; Olvera, Diana; Fuller, Seth M.; Kelly, James P.; Graeve, Olivia A.; Schwarz, Edward M.; Kates, Stephen L.; Awad, Hani A.

    2014-01-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1–2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing. PMID:24529628

  15. 3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration.

    PubMed

    Inzana, Jason A; Olvera, Diana; Fuller, Seth M; Kelly, James P; Graeve, Olivia A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2014-04-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1-2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing.

  16. Improved in vitro and in vivo collagen biosynthesis by asiaticoside-loaded ultradeformable vesicles.

    PubMed

    Paolino, Donatella; Cosco, Donato; Cilurzo, Felisa; Trapasso, Elena; Morittu, Valeria M; Celia, Christian; Fresta, Massimo

    2012-08-20

    The potentiality of ultradeformable vesicles as a possible topical delivery system for asiaticoside, a natural compound obtained from Centella asiatica was evaluated, because this compound exhibits collagen biosynthesis promoting activity. Ultradeformable vesicles were prepared by the extrusion technique; these vesicles were composed of Phospholipon 100 and different molar fractions of sodium cholate as the edge activator. The physicochemical properties of the ultradeformable vesicles were investigated through differential scanning calorimetry and light scattering techniques. The potential cyctotoxicity and biological activity of asiaticoside-loaded ultradeformable vesicles were evaluated on primary human dermal fibroblast cells by determining the extracellular lactic dehydrogenase activity, the cellular viability and the biosynthetic production of collagen. In vitro permeation experiments through human stratum corneum and epidermis membranes were also carried out. Ultradeformable vesicles having sodium cholate molar fraction of 0.2 proved to be the most suitable topical carriers for asiaticoside. A sodium cholate content of >0.2 was observed to be cytotoxic probably due to its co-existence with other lipid aggregates, an example being mixed micelles. Asiaticoside-loaded ultradeformable vesicles with a sodium cholate molar fraction of 0.2 elicited the greatest degree of collagen biosynthesis in human fibroblasts. Ultradeformable vesicles provided the greatest in vitro skin permeation of asiaticoside showing a 10-fold increase with respect to the free drug solution and favoured an increase in in vivo collagen biosynthesis. Ultradeformable vesicles are therefore suitable carriers for the pharmaceutical and cosmetic application of the natural agent asiaticoside.

  17. Preparation and characterization of collagen from soft-shelled turtle (Pelodiscus sinensis) skin for biomaterial applications.

    PubMed

    Nagai, Nobuhiro; Kobayashi, Hatsumi; Katayama, Shizuka; Munekata, Masanobu

    2009-01-01

    Collagen was isolated from the skin of soft-shelled turtle (Pelodiscus sinensis) by acid solubilization with pepsin. The yield of soft-shelled turtle collagen (STC) was 12.1% on a dry weight basis. The electrophoresis assay showed that STC consisted of a alpha(1)alpha(2) heterodimer similar to porcine collagen (PC). Amino-acid composition analysis showed that the hydroxyproline content of STC was 7.8%, which was lower than that of PC (9.5%). The denaturation temperature of STC was 36 degrees C from optical rotation analysis. An accelerated fibrillogenesis of STC was observed in phosphate-buffered saline at 25 degrees C. The resulting STC fibrillar gel had microfibrillar network with fibril diameter of ca. 124 nm, as revealed by observation with scanning electron microscopy. The compressive moduli of the STC gel and the PC gel were 3.2 +/- 0.8 kPa and 3.6 +/- 0.3 kPa, respectively. The potential of the STC gel for biomaterial applications was investigated by in vitro cell culture. Human dermal fibroblasts were three-dimensionally cultured in the STC gel and their growth was evaluated by DNA content measurement. Steady growth was observed in the STC gel for a 6-day culture period, although the growth rate was slower than in the PC gel. In conclusion, STC could be used as a novel collagen source for biomaterial applications.

  18. Surface modification of electrospun PLGA scaffold with collagen for bioengineered skin substitutes.

    PubMed

    Sadeghi, A R; Nokhasteh, S; Molavi, A M; Khorsand-Ghayeni, M; Naderi-Meshkin, H; Mahdizadeh, A

    2016-09-01

    In skin tissue engineering, surface feature of the scaffolds plays an important role in cell adhesion and proliferation. In this study, non-woven fibrous substrate based on poly (lactic-co-glycolic acid) (PLGA) (75/25) were hydrolyzed in various concentrations of NaOH (0.05N, 0.1N, 0.3N) to increase carboxyl and hydroxyl groups on the fiber surfaces. These functional groups were activated by EDC/NHS to create chemical bonding with collagen. To improve bioactivity, the activated substrates were coated with a collagen solution (2mg/ml) and cross-linking was carried out using the EDC/NHS in MES buffer. The effectiveness of the method was evaluated by contact angle measurements, porosimetry, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), tensile and degradation tests as well as in vitro cell attachment and cytotoxicity assays. Cell culture results of human dermal fibroblasts (HDF) and keratinocytes cell line (HaCat) revealed that the cells could attach to the scaffold. Further investigation with MTT assay showed that the cell proliferation of HaCat significantly increases with collagen coating. It seems that sufficient stability of collagen on the surface due to proper chemical bonding and cross-linking has increased the bioactivity of surface remarkably which can be promising for bioengineered skin applications. PMID:27207046

  19. Collagen-chitosan scaffold modified with Au and Ag nanoparticles: Synthesis and structure

    NASA Astrophysics Data System (ADS)

    Rubina, M. S.; Kamitov, E. E.; Zubavichus, Ya. V.; Peters, G. S.; Naumkin, A. V.; Suzer, S.; Vasil'kov, A. Yu.

    2016-03-01

    Nowadays, the dermal biomimetic scaffolds are widely used in regenerative medicine. Collagen-chitosan scaffold one of these materials possesses antibacterial activity, good compatibility with living tissues and has been already used as a wound-healing material. In this article, collagen-chitosan scaffolds modified with Ag and Au nanoparticles have been synthesized using novel method - the metal-vapor synthesis. The nanocomposite materials are characterized by XPS, TEM, SEM and synchrotron radiation-based X-ray techniques. According to XRD data, the mean size of the nanoparticles (NPs) is 10.5 nm and 20.2 nm in Au-Collagen-Chitosan (Au-CollCh) and Ag-Collagen-Chitosan (Ag-CollCh) scaffolds, respectively in fair agreement with the TEM data. SAXS analysis of the composites reveals an asymmetric size distribution peaked at 10 nm for Au-CollCh and 25 nm for Ag-CollCh indicative of particle's aggregation. According to SEM data, the metal-carrying scaffolds have layered structure and the nanoparticles are rather uniformly distributed on the surface material. XPS data indicate that the metallic nanoparticles are in their unoxidized/neutral states and dominantly stabilized within the chitosan-rich domains.

  20. Under-dermal emulator of vascular identification

    NASA Astrophysics Data System (ADS)

    Landa, Joseph; Blake, Robert; Rich, Alex; Szu, Harold

    2012-06-01

    The goal of this paper and research effort is to develop a simple and clear apparatus and approach to quantify the effectiveness of sensor systems as it relates to their ability to penetrate camouflage and resolve skin depth. Over the last decade, several attempts have been made to leverage advances in Infrared (IR) imaging, made by the military, into medical sensing [1]. Several promising technologies have been evaluated and thus far determined to be lacking when compared to the current standards of care based on x-ray imaging [2]. While progress has been made this general class of technology has not generated wide spread interest from the medical community. This lack of interest is discouraging, especially when considering the great potential for good that would result in successfully demonstrating a truly passive tumor detection system based on thermal signatures. Recently, this team participated as part of a larger group in the development and testing of a novel class of algorithms using images from two separate IR spectra. This area of spectral fusing algorithms is called the Single Pixel-Blind Source Separation (SP-BSS). While the goal of experiment is not new, our results showed this approach provided potential improvements over more traditional thermography, particularly in the area of overcoming environmental noise. These promising results have motivated us to develop a method for running controlled experiments so that the equipment and algorithms can be optimized and the significant engineering challenges of frame registration, data standardization, and sensor optimization for wellness screening can be accomplished. Conducting these efforts using data from human subjects is both impractical and unwarranted at this time. We have developed a physics-physiological under-dermal model of internal vascular circulation that approximates not only a healthy human body (angiogenesis effect) but also a human body developing a tumor (neo-angiogenesis effect). This

  1. Dermal sensitization quantitative risk assessment (QRA) for fragrance ingredients.

    PubMed

    Api, Anne Marie; Basketter, David A; Cadby, Peter A; Cano, Marie-France; Ellis, Graham; Gerberick, G Frank; Griem, Peter; McNamee, Pauline M; Ryan, Cindy A; Safford, Robert

    2008-10-01

    Based on chemical, cellular, and molecular understanding of dermal sensitization, an exposure-based quantitative risk assessment (QRA) can be conducted to determine safe use levels of fragrance ingredients in different consumer product types. The key steps are: (1) determination of benchmarks (no expected sensitization induction level (NESIL)); (2) application of sensitization assessment factors (SAF); and (3) consumer exposure (CEL) calculation through product use. Using these parameters, an acceptable exposure level (AEL) can be calculated and compared with the CEL. The ratio of AEL to CEL must be favorable to support safe use of the potential skin sensitizer. This ratio must be calculated for the fragrance ingredient in each product type. Based on the Research Institute for Fragrance Materials, Inc. (RIFM) Expert Panel's recommendation, RIFM and the International Fragrance Association (IFRA) have adopted the dermal sensitization QRA approach described in this review for fragrance ingredients identified as potential dermal sensitizers. This now forms the fragrance industry's core strategy for primary prevention of dermal sensitization to these materials in consumer products. This methodology is used to determine global fragrance industry product management practices (IFRA Standards) for fragrance ingredients that are potential dermal sensitizers. This paper describes the principles of the recommended approach, provides detailed review of all the information used in the dermal sensitization QRA approach for fragrance ingredients and presents key conclusions for its use now and refinement in the future.

  2. Comparative evaluation of a biomimic collagen/hydroxyapatite/β-tricaleium phosphate scaffold in alveolar ridge preservation with Bio-Oss Collagen

    NASA Astrophysics Data System (ADS)

    Wang, Tong; Li, Qing; Zhang, Gui-feng; Zhou, Gang; Yu, Xin; Zhang, Jing; Wang, Xiu-mei; Tang, Zhi-hui

    2016-06-01

    Bone scaffolds are critical in current implant and periodontal regeneration approaches. In this study, we prepared a novel composite type-I collagen and hydroxyapatite (HA)/β-tricaleium phosphate (TCP) scaffold (CHTS) by incorporating type-I collagen and bovine calcined bone granules, prepared as a mixture of 50% HA and 50% TCP, by freeze drying. We then characterized the CHTS and determined its cytotoxic effects. Additionally, ridge preservation experiments were carried out to evaluate the clinical effects of the CHTS. The results demonstrated that the composite scaffolds had good surface morphology and no cytotoxicity. Additionally, an in vivo experiment in an animal model showed that the CHTS performed equally as well as Bio-Oss Collagen, a widely used bone graft in ridge preservation. These findings revealed that the CHTS, which contained natural constituents of bone, could be used as a scaffold for bone regeneration and clinical use.

  3. The mechanism of hydralazine-induced collagen biosynthesis in cultured fibroblasts.

    PubMed

    Karna, Ewa; Szoka, Lukasz; Palka, Jerzy A

    2013-04-01

    The finding that hydralazine (HYD) affects collagen metabolism led us to investigate the mechanism of its action on collagen biosynthesis, prolidase expression and activity, expression of α2β1 integrin, insulin-like growth factor-I receptor (IGF-IR), focal adhesion kinase (FAK), mitogen-activated protein (MAP) kinases (ERK1, ERK2), and transcription factors hypoxia-inducible factor-1α (HIF-1α) and nuclear factor-κB p65 (NF-κB p65) in human dermal fibroblasts. Confluent fibroblasts were treated with micromolar concentrations (50-500 μM) of HYD for 24 h. HYD had no influence on cell viability. It was found that HYD-dependent increase in collagen biosynthesis was accompanied by a parallel increase in prolidase activity and expression, HIF-1α expression, and decrease in DNA biosynthesis, compared to untreated cells. Since collagen biosynthesis and prolidase activity are regulated by a signal induced by activated α2β1 integrin receptor as well as IGF-IR, the expression of these receptors was measured by Western immunoblot analysis. The exposure of the cells to HYD contributed to the increase in IGF-IR expression without any effect on α2β1 integrin receptor and FAK expressions. It was accompanied by a decrease in expression of MAP kinases and NF-κB p65, the known inhibitor of collagen gene expression. The data suggest that the HYD-dependent increase of collagen biosynthesis in cultured human skin fibroblasts results from activation of IGF-IR expression and prolidase activity and downregulation of NF-κB p65.

  4. Histopathology of the three implanted degradable biopolymers in rabbit eye.

    PubMed

    Rönkkö, Seppo; Rekonen, Petri; Sihvola, Roope; Kaarniranta, Kai; Puustjärvi, Tuomo; Teräsvirta, Markku; Uusitalo, Hannu

    2009-03-01

    New straightforward applications of new biopolymers are needed in glaucoma surgery. The aim of this study was to compare biocompatibility of three biomaterials in rabbit eyes after deep sclerectomy; a collagen implant (AquaFlow) represented the "gold standard". A blend of 85:15 poly(L-lactide-co-glycolide) and 70:30 poly(L-lactide-co-1,3-trimethylene carbonate) copolymers in a molar ratio of 70:30 (Bio-1 = Inion GTR membrane) and poly(DL-lactide-co-glycolide with molar compositions of 50:50 (Bio-2) and 85:15 (Bio-3) were inserted into rabbits eyes. Bio-1, Bio-2 or Bio-3 caused very mild eye irritation or tissue response which was comparable to that of the collagen implant. The biodegradation time of Bio-1, Bio-2, and Bio-3 implants was over one year, 3 months and 6 months, respectively. Implant mapping by Fourier transform infrared (FTIR) microscopy revealed a heterogeneous distribution of degradation products throughout Bio-1, Bio-2, and Bio-3. All implants were surrounded by a very fine tissue capsule which was not visible after total degradation of the implants. The FTIR spectrum of tissue capsule around Bio-1 was almost identical to that around Bio-2 whereas significant differences were observed in the spectrum of the tissue capsule around Bio-3. Despite some differences in tissue response, all tested implants represent biologically acceptable materials for drainage devices in glaucoma surgery. PMID:18335536

  5. [Biological implant in single-stage reconstruction of mammary gland for cancer].

    PubMed

    Zikiriakhodzhaev, A D; Ermoshchenkova, M V

    2015-01-01

    Brief literature review about features of biological implants application for mammary gland reconstruction is presented in the article. Possible complications after such materials use, first experience of acellular dermal matrix administration for single-stage mammary gland reconstruction in 6 patients with breast cancer are also described. We offered surgical techniques, complications and methods of its treatment. We presented advantages of biological implant use which are consisted in decrease of surgical damage and duration of surgery, opportunity for enlargement of pocket for implant, decrease of pain syndrome. PMID:25909549

  6. Application of the Skin and Bone Integrated Pylon (SBIP) with titanium oxide nanotubes and seeded with dermal fibroblasts

    PubMed Central

    Shevtsov, Maxim A.; Yudintceva, Natalia M.; Blinova, Miralda I.; Pinaev, Grigoriy P.; Galibin, Oleg V.; Potokin, Igor L.; Popat, Ketul C.; Pitkin, Mark R.

    2014-01-01

    Study Design The feasibility and safety of in bone implantation of the skin and bone integrated pylons (SBIP) with nanotubes was investigated in vitro and in vivo in the animal model. Background Direct Direct skeletal attachment of limb prostheses is associated with high rate of transcutaneous infection and loosening of the fixture in the medullary canal prompting for careful assessment of various means for enhancing the skin-device and bone-device interface. The SBIP system constitutes a technological platform for different modifications being evaluated previously. Objectives The current study assessed the combination of nano treatment SBIP with its pre seeding with dermal fibroblasts. We hypothesized that this combination will enhance cell interaction with SBIP compared to nano treatment and the fibroblast seeding when done separately. Methods TiO2 nanotubes were fabricated on the SBIP, and the fibroblasts taken from rabbit's skin were cultured on the pylons before implantation. Results The in vitro experiments demonstrated higher cellular density in the samples with a nanotubular surface than in the non modified pylons used as control. There were no postoperative complications in any of the animals during the 6 month observation period. Subsequent SEM of the pylon extracted from the rabbit's femur showed the stable contact between the pylon and soft tissues in comparison to control samples where the patchy fibrovascular ingrowth was detected. Conclusions The promising results prompt further investigation of the integrative properties of the nanotextured SBIP system seeded with dermal fibroblasts and its optimization for clinical application. PMID:25249382

  7. Dermal absorption of inorganic germanium in rats.

    PubMed

    Yokoi, Katsuhiko; Kawaai, Takae; Konomi, Aki; Uchida, Yuka

    2008-11-01

    So-called germanium 'health' products including dietary supplements, cosmetics, accessories, and warm bath service containing germanium compounds and metalloid are popular in Japan. Subchronic and chronic oral exposure of germanium dioxide (GeO(2)), popular chemical form of inorganic germanium causes severe germanium toxicosis including death and kidney dysfunction in humans and experimental animals. Intestinal absorption of neutralized GeO(2) or germanate is almost complete in humans and animals. However, it is not known whether germanium is cutaneously absorbed. We tested dermal absorption of neutralized GeO(2) or germanate using male F344/N rats. Three groups of rats were treated with a 3-h topical application of hydrophilic ointment containing graded level of neutralized GeO(2) (pH 7.4): 0, 0.21 and 0.42 mg GeO(2)/g. Germanium concentration in blood and tissues sampled from rats after topical application of inorganic germanium was measured by inductively coupled plasma-mass spectrometry. Animals topically applied 0.42 mg GeO(2)/g ointment had significantly higher germanium concentrations in plasma, liver, and kidney than those of rats that received no topical germanium. The results indicate that skin is permeable to inorganic germanium ion or germanate and recurrent exposure of germanium compounds may pose a potential health hazard.

  8. Acellular Dermal Matrix in Rotator Cuff Surgery.

    PubMed

    Cooper, Joseph; Mirzayan, Raffy

    2016-01-01

    The success of rotator cuff repair (RCR) surgery can be measured clinically (validated outcome scores, range of motion) as well as structurally (re-tear rates using imaging studies). Regardless of repair type or technique, most studies have shown that patients do well clinically. However, multiple studies have also shown that structurally, the failure rate can be very high. A variety of factors, including poor tendon quality, age over 63 years, smoking, advanced fatty infiltration into the muscle, and the inability of the tendon to heal to bone, have been implicated as the cause of the high re-tear rate in RCRs. The suture-tendon interface is felt to be the weakest link in the RCR construct, and suture pullout through the tendon is believed to be the most common method of failure. This review of the published literature seeks to determine if there is support for augmentation of RCR with acellular dermal matrices to strengthen the suture-tendon interface and reduce the re-tear rate. PMID:27552454

  9. [Conservative anal fistula treatment with collagenic plug and human fibrin sealant. Preliminary results].

    PubMed

    Gubitosi, A; Moccia, G; Malinconico, F A; Docimo, G; Ruggiero, R; Iside, G; Avenia, N; Docimo, L; Foroni, F; Gilio, F; Sparavigna, L; Agresti, M

    2009-01-01

    The authors, on the basis of a long clinical experience with human fibrin glue in general surgery, compared two different extracellular matrix (collagen), Surgisis and TissueDura, with human fibrin glue, applied during the operation, and sometimes in postoperative, to obtain the healing of perianal fistulas. The collagenic extracellular matrix provides, according to the rationale suggested, an optimal three-dimensional structure for the fibroblastic implant and neoangiogenesis, hence for the fistula "fibrotizzation" and closure. The encouraging results for transphincteric fistulas and a simple and easy technique push to researchers on samples statistically significant. PMID:19272233

  10. Clinical use of injectable collagen. A three-year retrospective review.

    PubMed

    Kamer, F M; Churukian, M M

    1984-02-01

    Collagen implants (Zyderm) have found extensive applications in the adjunctive management of the aging face and in the primary treatment of cutaneous defects resulting from acne, trauma, or prior surgery. Our initial clinical experience from 1979 to 1982 involving more than 300 patients is analyzed for treatment efficacy, duration, and untoward responses. A majority of our patients are clearly pleased. Likewise, our confidence has increased as our experience evolved. Positive skin tests number 3.5% and delayed hypersensitivity reactions 1.3%. We have found injectable collagen relatively easy to use as well as safe and effective. Further research may enable prolonged results.

  11. Immediate Implant-based Prepectoral Breast Reconstruction Using a Vertical Incision

    PubMed Central

    Lind, Jeffrey G.; Hopkins, Elizabeth G.

    2015-01-01

    Background: Ideally, breast reconstruction is performed at the time of mastectomy in a single stage with minimal scarring. However, postoperative complications with direct-to-implant subpectoral reconstruction remain significant. These include asymmetry, flap necrosis, animation deformity, and discomfort. We report on a series of patients who have undergone immediate single-stage prepectoral, implant-based breast reconstruction with a smooth, adjustable saline implant covered with mesh/acellular dermal matrix for support using a vertical mastectomy incision. This technique, when combined with an adjustable implant, addresses the complications related to subpectoral implant placement of traditional expanders. Our follow-up time, 4.6 years (55 months), shows a low risk of implant loss and elimination of animation deformity while also providing patients with a safe and aesthetically pleasing result. Methods: All patients who underwent immediate implant-based prepectoral breast reconstruction using a vertical mastectomy incision as a single-staged procedure were included. Charts were reviewed retrospectively. Adjustable smooth round saline implants and mesh/acellular dermal matrix were used for fixation in all cases. Results: Thirty-one patients (62 breasts) underwent single-staged implant-based prepectoral breast reconstruction using a vertical mastectomy incision. Postoperative complications occurred in 9 patients, 6 of which were resolved with postoperative intervention while only 2 cases resulted in implant loss. Conclusions: There can be significant morbidity associated with traditional subpectoral implant-based breast reconstruction. As an alternative, the results of this study show that an immediate single-stage prepectoral breast reconstruction with a smooth saline adjustable implant, using a vertical incision, in conjunction with mesh/matrix support can be performed with excellent aesthetic outcomes and minimal complications. PMID:26180713

  12. Collagen shield delivery of trifluorothymidine.

    PubMed

    Gussler, J R; Ashton, P; VanMeter, W S; Smith, T J

    1990-11-01

    Corneal and aqueous levels of topically applied trifluorothymidine (F3T) were compared with and without the collagen shield in normal and damaged rabbit eyes. Shields were presoaked in 1% F3T for 15 minutes prior to application. Rabbits received either a presoaked shield, 1% F3T drops every two hours, or both. Corneal and aqueous levels of F3T were measured at 30 minutes, two, four, and eight hours. If 5 mm epithelial defects were created, the collagen shield and topical F3T drops produced significantly higher levels of F3T than drops alone at all periods tested (P less than .05). A presoaked shield alone produced greater levels of F3T than drops alone at 30 minutes and two hours (P less than .05). Collagen shields did not enhance F3T levels in eyes with intact epithelium. Implications for treatment of herpetic keratouveitis are discussed.

  13. Short Implants: New Horizon in Implant Dentistry

    PubMed Central

    Gulati, Manisha; Garg, Meenu; Pathak, Chetan

    2016-01-01

    The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration. PMID:27790598

  14. Collagen VI related muscle disorders

    PubMed Central

    Lampe, A; Bushby, K

    2005-01-01

    Mutations in the genes encoding collagen VI (COL6A1, COL6A2, and COL6A3) cause Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD), two conditions which were previously believed to be completely separate entities. BM is a relatively mild dominantly inherited disorder characterised by proximal weakness and distal joint contractures. UCMD was originally described as an autosomal recessive condition causing severe muscle weakness with proximal joint contractures and distal hyperlaxity. Here we review the clinical phenotypes of BM and UCMD and their diagnosis and management, and provide an overview of the current knowledge of the pathogenesis of collagen VI related disorders. PMID:16141002

  15. Re-stability of dental implants following treatment of peri-implantitis

    PubMed Central

    Hussain, Hamza Ather; Romanos, Georgios E.

    2013-01-01

    It is hypothesized that active treatment of peri-implantitis (PI) leads to re-stabilization of dental implants. The aim was to assess whether or not dental implants can re-stabilize following treatment of PI. To address the focused question, MEDLINE/PubMed and Google-Scholar databases were explored from 1977 up to and including August 2013. Any disagreements between the authors were resolved via discussion. Articles published only in English were included. Hand searching was also performed. Thirteen experimental studies were included. The treatment regimes adopted in these studies comprised of antibiotic therapy, guided bone regeneration (GBR), laser therapy, use of bone matrix proteins with membrane, conventional flap surgery and mechanical debridement. In four studies, GBR promoted new bone formation; whereas two studies showed photosensitization therapy (in combination with either mechanical debridement or GBR) to regenerate bone around peri-implant defects. Six studies reported that mechanical debridement in conjunction with antibiotic therapy promoted re-stability of dental implants. In one study, recombinant human bone matrix protein-2 with a collagen membrane helped promote re-stabilization of dental implants. New bone formation may occur to some extent around dental implants following treatment for PI; however, a “complete” re-stability may be difficult to achieve without GBR. PMID:24265901

  16. Clinical evaluations of mineralized collagen in the extraction sites preservation

    PubMed Central

    Feng, Lu; Zhang, Liang; Cui, Yun; Song, Tian-Xi; Qiu, Zhi-Ye; Wang, Xiu-Mei; Tan, Bao-Sheng

    2016-01-01

    The purpose of this study was to explore the different effects between biomimetic mineralized collagen (MC) and ordinary physically blended hydroxyapatite/collagen (HA/Col) composite in evaluating new bone formation and regenerated bone height in human extraction sockets. Thirty-four patients who cannot retain teeth caused by trauma or decay were randomly selected from Department of Stomatology of Dongzhimen Hospital from December 2013 to December 2014. The patients were randomly divided into two groups. After the operation of tooth extraction, 17 patients were implanted with biomimetic MC (MC group), and other 17 patients were implanted with ordinary physically blended nHA/Col composite (nHA/Col group). X-ray positioning projection by auto-photographing was taken to test the distance between the lowest position and the neighboring CEJm-CEJd immediately, 1 month and 3 months after the operation. The height of new bone formation of the MC group was significantly higher than the nHA/Col group. Biomimetic MC showed better clinical outcomes in the bone formation for extraction site preservation and would have broad application prospect in the field of oral and maxillofacial surgeries. PMID:26815224

  17. Study of chemical properties and evaluation of collagen in mantle, epidermal connective tissue and tentacle of Indian Squid, Loligo duvauceli Orbigny.

    PubMed

    Raman, Maya; Mathew, Saleena

    2014-08-01

    The chemical composition and evaluation of Indian squid (Loligo duvauceli) mantle, epidermal connective tissue and tentacle is investigated in this current study. It is observed that squid mantle contains 22.2% total protein; 63.5% of the total protein is myofibrillar protein. The unique property of squid myofibrillar protein is its water solubility. Squid mantle contains 12.0% total collagen. Epidermal connective tissue has highest amounts of total collagen (17.8%). SDS-PAGE of total collagen identified high molecular weight α-, β- and γ- sub-chains. Amino acid profile analysis indicates that mantle and tentacle contain essential amino acids. Arginine forms a major portion of mantle collagen (272.5 g/100 g N). Isoleucine, glutamic acid and lysine are other amino acids that are found in significantly high amounts in the mantle. Sulphur containing cystine is deficit in mantle collagen. Papain digest of mantle and epidermal connective tissue is rich in uronic acid, while papain digest, collagenase digest and urea digest of epidermal connective tissue has significant amounts of sialic acid (25.2, 33.2 and 99.8 μmol /100 g, respectively). PAS staining of papain digest, collagenase digest and urea digest also identify the association of hexoses with low molecular weight collagen fragments. Histochemical sectioning also emphasized the localized distribution of collagen in epidermal and dermal region and very sparse fibres traverse the myotome bundles. PMID:25114341

  18. The evolution of fibrillar collagens: a sea-pen collagen shares common features with vertebrate type V collagen.

    PubMed

    Tillet, E; Franc, J M; Franc, S; Garrone, R

    1996-02-01

    The extracellular matrix of marine primitive invertebrates (sponges, polyps and jellyfishes) contains collagen fibrils with narrow diameters. From various data, it has been hypothesized that these primitive collagens could represent ancestral forms of the vertebrate minor collagens, i.e., types V or XI. Recently we have isolated a primitive collagen from the soft tissues of the sea-pen Veretillum cynomorium. This report examines whether the sea-pen collagen shares some features with vertebrate type V collagen. Rotary shadowed images of acid-soluble collagen molecules extracted from beta-APN treated animals, positive staining of segment-long-spacing crystallites precipitated from pepsinized collagen, Western blots of the pepsinized alpha1 and alpha2 chains with antibodies to vertebrate types I, III and V collagens, and in situ gold immunolab