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Sample records for holmium-166 chitosan complex

  1. Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy.

    PubMed

    Cho, Y J; Kim, K I; Chun, Y S; Rhyu, K H; Kwon, B K; Kim, D Y; Yoo, M C

    2010-07-01

    Radiosynoviorthesis is a safe and easy method for synovectomy in haemophilic arthropathy. Various agents have been used in radiosynoviorthesis, especially newly developed agent Holmium-166-chitosan complex has good clinical outcome. This study analysed clinical results and radiologic evaluation of radioisotope synoviorthesis using Holmium-166-chitosan complex in haemophilic arthropathy. From March 2001 to December 2003, 58 radiosynoviorthesis were performed in 53 haemophiliacs. The average age at procedure was 13.8 years. The Arnold and Hilgartner stage of the patients was from I to IV. Holmium-166-chitosan complex was injected in 31 ankle joints, 19 elbow joints and 8 knee joints. Average follow-up was 33 months since primary procedure. The range of motion of each joint, frequency of intra-articular bleeding and factor dose used were analysed for clinical assessment. There was no significant improvement of range of motion in affected joints. After procedure, the average frequency of bleeding of the elbow joint has decreased from 3.76 to 0.47 times per month, the knee joint from 5.87 to 1.12 times per month, and the ankle joint from 3.62 to 0.73 times per month respectively (P < 0.05). After treatment, the average coagulation factor dose injected was significantly decreased to 779.3 units per month from 2814.8 units per month before treatment (P < 0.001). Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy is a very safe and simple procedure with the expectation of a satisfactory outcome without serious complication. It has excellent bleeding control effect on target joint and the need for substitution of coagulation factor concentrate can be reduced.

  2. Percutaneous Sclerotherapy of Renal Cysts with a Beta-Emitting Radionuclide, Holmium-166-chitosan Complex

    PubMed Central

    Kim, Joo Hee; Kim, Eun Kyung; Won, Jong Yoon; Kim, Myeong-Jin; Lee, Jong Doo; Hong, Sung Joon

    2004-01-01

    Objective To evaluate the usefulness of a beta-emitting radionuclide (holmium-166-chitosan complex) as a sclerosing agent for the treatment of renal cysts. Materials and Methods Using 10-30 mCi of holmium-166-chitosan complex, 20 renal cysts in 17 patients (14 male and 3 female patients, ranging in age from 47 to 82 years) were treated by percutaneous sclerotherapy under ultrasonographic guidance. The volume of the cysts before and after the sclerotherapy and the percentage change in volume were calculated in order to evaluate the response to therapy, which was classified as either complete regression (invisible), nearly complete regression (< 15 volume% of initial volume), partial regression (15-50 volume%) or no regression (> 50 volume%). Results The follow-up period ranged from 6 to 36 months (mean 28 months). Eighteen cysts (90%) regressed completely (n=11, 55%) or near-completely (n=7, 35%). Partial regression was obtained in one patient (5%) and there was no regression in one patient (5%). No significant complications were encountered. Conclusion The holmium-166-chitosan complex seems to be useful as a new painless sclerosing agent for the treatment of renal cysts with no significant complications. PMID:15235238

  3. Therapeutic Effects of Holmium-166 Chitosan Complex in Rat Brain Tumor Model

    PubMed Central

    Huh, Ryoong; Park, Yong Sook; Lee, Jong Doo; Chung, Young Sun; Park, Yong Gou; Chung, Sang Sup

    2005-01-01

    This study examined the effectiveness of Holmium-166 (Ho-166) chitosan complex therapy for a malignant glioma. Cultured C6 glioma cells (100,000 in 5 µl) were injected into the caudate/putamen of 200 - 250 gram Wistar rats. Five days later, a Ho-166 chitosan complex was injected into the same site of the glioma injection. Four injection doses were administered: the control group received PBS 10 µl, group 1 received an injection of 100 µCi (10 µl), group 2 received an injection of 50 µCi (5 µl), and group 3 received an injection of 10 µCi (1 µl). The average tumor volume for each group was 1.385 mm3 for the control group, 0.036 mm3 for group 1, 0.104 mm3 for group 2, and 0.111 mm3 for group 3. Compared with the control group, the size of the tumors in groups 1, 2 and 3 was reduced by an average of 97.4%, 92.5% and 91.9%, respectively. The Kaplan-Meier survival curve of group 2 was the longest, followed by groups 3, group 1 and the control. The mean survival was 22.8, 59, 60, and 44.6 days for the control group and groups 3, 2 and 1, respectively. H-E staining revealed that group 2 yielded the best results in the destruction of the malignant glioma. TUNEL staining and immunohistochemical studies indicated apoptotic features. The Ho-166 chitosan complex proved to be effective in destroying the malignant glioma. PMID:15744805

  4. Phase II study of transarterial holmium-166-chitosan complex treatment in patients with a single, large hepatocellular carcinoma.

    PubMed

    Sohn, Joo Hyuk; Choi, Hye Jin; Lee, Jong Tae; Lee, Jong Doo; Kim, Joo Hang; Moon, Young Myung; Park, Kyungsoo; Park, Kyung Bae; Kim, Eunhee; Yoo, Nae Choon

    2009-01-01

    Holmium-166 ((166)Ho) is a neutron-activated radioactive isotope whose effectiveness in hepatocellular carcinoma (HCC) was first reported in a preclinical study in 1991. Chitosan is a polymer of 2-deoxy-2-amino-D-glucose that readily forms a chelate with heavy metals and converts from a solution under acidic conditions into a gel under neutral or basic conditions. We performed a prospective trial of a transarterial administration of a radiopharmaceutical (166)Ho-chitosan complex in patients with single, large HCC. The study involved 54 patients who had single HCC (>or=3 cm) without a vascular shunt and were either inoperable or refused surgery. The (166)Ho-chitosan complex was administered at a dose of 20 mCi per cm of tumor diameter (capping at 200 mCi) via the artery that directly fed the tumor. The median tumor size was 5.3 cm (range: 3-13 cm). The response rate was 78% (42/54), and 31 patients had a complete response for a median duration of 27 months. The incidence of grade 3 or 4 leukopenia was 18.6%, anemia 7.4%, thrombocytopenia 27.8%, AST/ALT elevation 26%/24%, and total bilirubin elevation 5.6%. There were two treatment-related deaths (3.7%). Subset analysis revealed a substantial difference between the two groups categorized by tumor size (3-5 vs. >5 cm) with respect to response rate (p = 0.004) and overall survival (p = 0.02). We found that transarterial administration of the (166)Ho-chitosan complex was highly effective in the treatment of HCC with acceptable toxicities, especially for patients with tumors of 3-5 cm.

  5. MR Evaluation of Radiation Synovectomy of the Knee by Means of Intra-articular Injection of Holmium-166-Chitosan Complex in Patients with Rheumatoid Arthritis: Results at 4-month Follow-up

    PubMed Central

    Lee, Sang Hoon; Kim, Ho Seok; Lee, Jong Doo; Song, Jungsik; Lee, Soo Kon

    2003-01-01

    Objective To determine whether MRI is able to demonstrate the effect of radiation synovectomy after the intra-articular injection of holmium-166-chitosan complex for the treatment of rheumatoid arthritis of the knee. Materials and Methods Fourteen patients aged 36-59 years were treated with 10-20 mCi of holmium-166-chitosan complex. A criterion for inclusion in this study was the absence of observable improvement after 3- or more months of treatment of the knee with disease-modifying anti-rheumatic drugs. MR images were acquired both prior to and 4-months after treatment. Clinical evaluation included the use of visual analog scales to assess pain, and the circumference of the knee and its range of motion were also determined. MR evaluation included measurement of the volume of synovial enhancement and wall thickness, the amount of joint effusion, and quantifiable scoring of bone erosion, bone edema and lymph nodes. Results Visual analog scale readings decreased significantly after radiation synovectomy (p < 0.05). MRI showed that joint effusion decreased significantly (p < 0.05), and that the volume of synovial enhancement tended to decrease, but to an insignificant extent (p = 0.107). Conclusion The decreased joint effusion noted at 4-month follow-up resulted from radiation synovectomy of the rheumatoid knee by means of intra-articular injection of holmium-166-chitosan complex. PMID:14530646

  6. Radiation emission from patients treated with holmium-166 radioembolization.

    PubMed

    Prince, Jip F; Smits, Maarten L J; Krijger, Gerard C; Zonnenberg, Bernard A; van den Bosch, Maurice A A J; Nijsen, Johannes F W; Lam, Marnix G E H

    2014-12-01

    To assess the radiation exposure to individuals coming from patients after treatment with holmium-166 ((166)Ho) microspheres. Holmium-166 radioembolization (RE) with escalating whole-liver doses of 20 Gy, 40 Gy, 60 Gy, and 80 Gy was administered to 15 patients. Exposure rates (μSv/h) from patients were measured at 1.0 m distance from a lateral and frontal position at 0, 3, 6, 24, and 48 hours after infusion. The total effective dose equivalent (TEDE) to a maximally exposed contact was calculated in accordance with guidelines of the U.S. Nuclear Regulatory Commission (NRC). Results were extrapolated to a whole-liver dose of 60 Gy used in future treatments. The median exposure rate at discharge, 48 hours after infusion, measured from a lateral position was 26 μSv/h (range, 7-45 μSv/h). Extrapolated to a whole-liver dose of 60 Gy, none of the exposure rates for the NRC contact scenario, at any time, frontal or lateral, would lead to a TEDE > 5 mSv; all patients may be released directly after treatment. Release after 6 hours is possible without contact restrictions for patients who received up to 7 GBq. The TEDE to a contact of patients treated with (166)Ho RE would not exceed the NRC limit of 5 mSv. Contact restrictions 6 hours after treatment are unnecessary for infused activities < 7 GBq. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

  7. Composition and method of treatment of arthritis and related diseases with holmium-166 radionuclides

    SciTech Connect

    Lieberman, E.; Bordoni, M.E.; Thornton, A.K.

    1991-10-29

    This patent describes a radioactive composition for the treatment of arthritis. It comprises a suspension containing particles having a minimum size of one micron, the suspension including particles containing holmium-166.

  8. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction.

    PubMed

    Elschot, Mattijs; Smits, Maarten L J; Nijsen, Johannes F W; Lam, Marnix G E H; Zonnenberg, Bernard A; van den Bosch, Maurice A A J; Viergever, Max A; de Jong, Hugo W A M

    2013-11-01

    Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ((166)Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative (166)Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum. A fast Monte Carlo (MC) simulator was developed for simulation of (166)Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full (166)Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A(est)) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six (166)Ho RE patients. At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ≥ 17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96-106.21 ml were improved from 32%-63% (SPECT-DSW) and 50%-80% (SPECT-ppMC+DSW) to 76%-103% (SPECT-fMC). Furthermore

  9. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction

    SciTech Connect

    Elschot, Mattijs; Smits, Maarten L. J.; Nijsen, Johannes F. W.; Lam, Marnix G. E. H.; Zonnenberg, Bernard A.; Bosch, Maurice A. A. J. van den; Jong, Hugo W. A. M. de; Viergever, Max A.

    2013-11-15

    Purpose: Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ({sup 166}Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative {sup 166}Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum.Methods: A fast Monte Carlo (MC) simulator was developed for simulation of {sup 166}Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full {sup 166}Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A{sup est}) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six {sup 166}Ho RE patients.Results: At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ≥17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96–106.21 ml were improved from 32%–63% (SPECT-DSW) and 50%–80

  10. Separation of carrier-free holmium-166 from neutron-irradiated dysprosium targets

    SciTech Connect

    Dadachova, E.; Lambrecht, R.M.; Hetherington, E.L. ); Mirzadeh, S.; Knapp, F.F. Jr. )

    1994-12-01

    Holmium-166 ([sup 166]Ho, t[sub 1/2] = 26.4 h) is utilized in radiotherapeutic applications such as radioimmunospecific pharmaceuticals, bone marrow ablation, and radiation synovectomy. High specific activity [sup 166]Ho can be obtained from the decay of dysprosium-166 ([sup 166]Dy, t[sub 1/2] = 81.5 h). Dysprosium-166 is produced by the [sup 164]Dy[n,[gamma

  11. MRI-based biodistribution assessment of holmium-166 poly(L-lactic acid) microspheres after radioembolisation.

    PubMed

    van de Maat, Gerrit H; Seevinck, Peter R; Elschot, Mattijs; Smits, Maarten L J; de Leeuw, Hendrik; van Het Schip, Alfred D; Vente, Maarten A D; Zonnenberg, Bernard A; de Jong, Hugo W A M; Lam, Marnix G E H; Viergever, Max A; van den Bosch, Maurice A A J; Nijsen, Johannes F W; Bakker, Chris J G

    2013-03-01

    To demonstrate the feasibility of MRI-based assessment of the intrahepatic Ho-PLLA-MS biodistribution after radioembolisation in order to estimate the absorbed radiation dose. Fifteen patients were treated with holmium-166 ((166)Ho) poly(L-lactic acid)-loaded microspheres (Ho-PLLA-MS, mean 484 mg; range 408-593 mg) in a phase I study. Multi-echo gradient-echo MR images were acquired from which R (2) maps were constructed. The amount of Ho-PLLA-MS in the liver was determined by using the relaxivity r (2) of the Ho-PLLA-MS and compared with the administered amount. Quantitative single photon emission computed tomography (SPECT) was used for comparison with MRI regarding the whole liver absorbed radiation dose. R (2) maps visualised the deposition of Ho-PLLA-MS with great detail. The mean total amount of Ho-PLLA-MS detected in the liver based on MRI was 431 mg (range 236-666 mg) or 89 ± 19 % of the delivered amount (correlation coefficient r = 0.7; P < 0.01). A good correlation was found between the whole liver mean absorbed radiation dose as assessed by MRI and SPECT (correlation coefficient r = 0.927; P < 0.001). MRI-based dosimetry for holmium-166 radioembolisation is feasible. Biodistribution is visualised with great detail and quantitative measurements are possible.

  12. Safety analysis of holmium-166 microsphere scout dose imaging during radioembolisation work-up: A cohort study.

    PubMed

    Braat, Arthur J A T; Prince, Jip F; van Rooij, Rob; Bruijnen, Rutger C G; van den Bosch, Maurice A A J; Lam, Marnix G E H

    2017-08-07

    Radioembolisation is generally preceded by a scout dose of technetium-99m-macroaggregated albumin to estimate extrahepatic shunting of activity. Holmium-166 microspheres can be used as a scout dose (±250 MBq) and as a therapeutic dose. The general toxicity of a holmium-166 scout dose ((166)Ho-SD) and safety concerns of an accidental extrahepatic deposition of (166)Ho-SD were investigated. All patients who received a (166)Ho-SD in our institute were reviewed for general toxicity and extrahepatic depositions. The absorbed dose in extrahepatic tissue was calculated on SPECT/CT and correlated to clinical toxicities. In total, 82 patients were included. No relevant clinical toxicity occurred. Six patients had an extrahepatic deposition of (166)Ho-SD (median administered activity 270 MBq). The extrahepatic depositions (median activity 3.7 MBq) were located in the duodenum (3x), gastric fundus, falciform ligament and the lesser curvature of the stomach, and were deposited in a median volume of 15.3 ml, which resulted in an estimated median absorbed dose of 3.6 Gy (range 0.3-13.8 Gy). No adverse events related to the extrahepatic deposition of the (166)Ho-SD occurred after a median follow-up of 4 months (range 1-12 months). These results support the safety of 250 MBq (166)Ho-SD in a clinical setting. • A holmium-166 scout dose is safe in a clinical setting. • Holmium-166 scout dose is a safe alternative for (99m) Tc-MAA for radioembolisation work-up. • Holmium-166 scout dose potentially has several benefits over (99m) Tc-MAA for radioembolisation work-up.

  13. Effects of Intraluminal Irradiation with Holmium-166 for TIPS Stenosis: Experimental Study in a Swine Model

    PubMed Central

    Park, Ji Seon; Kim, Deog Yoon; Park, Yong Koo; Park, Sang Joon; Kim, Soo Joong

    2007-01-01

    Objective We wanted to evaluate the effectiveness of intraluminal irradiation with Holmium-166 (166Ho) for reducing the pseudointimal hyperplasia (PIH) in the transjugular intrahepatic portosystemic shunt (TIPS) tract in a swine model. Materials and Methods TIPS was performed in 12 domestic pigs, after the creation of portal hypertension by intraportal injection of a mixture of N-butyl-2-cyanoacrylate (NBCA) and lipiodol. Five pigs first underwent intraluminal irradiation (30 Gy) in the parenchymal tract with using a 166Ho solution-filled balloon catheter, and this was followed by the placement of a nitinol stent in the TIPS tract. For the seven control pigs, the balloon was filled with saline and contrast media mixture. Two weeks later, follow-up portography and histological analysis were performed. Results TIPS was successfully performed in all twelve pigs with achieving artificially induced portal hypertension. Portography performed two weeks after TIPS showed the patent tracts in the TIPS tracts that were irradiated with 166Ho (5/5, 100%), whereas either completely (5/6, 83.3%) or partially (1/6, 16.7%) occluded TIPS were seen in the seven pigs of the nonirradiated control group, except in one pig that experienced periprocedural death due to bleeding. Histological analysis showed a statistically significant difference for the maximal PIH (irradiated: 32.8%, nonirradiated: 76.0%, p < 0.001) between the two groups. Conclusion Intraluminal irradiation with 30 Gy of 166Ho for TIPS significantly improved the TIPS patency in a swine model of portal hypertension during a 2-week period of follow-up. PMID:17420630

  14. Microbrachytherapy using holmium-166 acetylacetonate microspheres: a pilot study in a spontaneous cancer animal model.

    PubMed

    Bult, Wouter; Vente, Maarten A D; Vandermeulen, Eva; Gielen, Ingrid; Seevinck, Peter R; Saunders, Jimmy; van Het Schip, Alfred D; Bakker, Chris J G; Krijger, Gerard C; Peremans, Kathelijne; Nijsen, Johannes F W

    2013-01-01

    Holmium-166 acetylacetonate microspheres ((166)Ho-AcAc-MS) are proposed as an intratumoral radioablation device. This article presents a pilot study in housecats with unresectable liver cancer. Feasibility and tolerability of intratumoral administrations of (166)Ho-AcAc-MS was investigated. Three cats with unresectable liver tumors of different histotype were included. One cat had hepatocellular carcinoma (HCC), one had cholangiocarcinoma (CC), and one had a malignant epithelial liver tumor (MELT) of unspecified histotype. (166)Ho-AcAc-MS were injected percutaneously under ultrasound guidance into the tumors. Followup consisted of physical examinations and hematologic and biochemical analyses. (166)Ho-AcAc-MS were administered to three liver tumor-bearing cats. The treatment was well tolerated and the clinical condition, that is body weight, alertness, mobility, and coat condition of the animals improved markedly. Most biochemical and hematologic parameters normalized shortly after treatment. Life of all cats was extended and associated with a good quality of life. The HCC cat that received 33-Gy tumor-absorbed dose was euthanized 6 months after the first administration owing to disease progression. The MELT cat received 99-Gy tumor dose and was euthanized 3 months posttreatment owing to bacterial meningitis. The CC cat received 333Gy and succumbed 4 months after the first treatment owing to the formation of a pulmonary embolism. Percutaneous intratumoral injection of radioactive (166)Ho-AcAc-MS is feasible in liver tumor-bearing cats. The findings of this pilot study indicate that (166)Ho-AcAc-MS may constitute safe brachytherapeutic microspheres and warrant studies to confirm the clinical utility of this novel brachytherapy device. Copyright © 2013 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  15. Analysis of lapine cartilage matrix after radiosynovectomy with holmium-166 ferric hydroxide macroaggregate

    PubMed Central

    Makela, O; Lammi, M; Uusitalo, H; Hyttinen, M; Vuorio, E; Helminen, H; Tulamo, R

    2003-01-01

    Objective: To study the short and long term effects of radiosynovectomy on articular cartilage in growing and mature rabbits. Methods: The articular cartilage of the distal femurs of rabbits was examined four days, two months, and one year after radiosynovectomy with holmium-166 ferric hydroxide macroaggregate ([166Ho]FHMA). Arthritic changes were evaluated from histological sections by conventional and polarised light microscopy, and glycosaminoglycan measurements using safranin O staining, digital densitometry, and uronic acid determination. Proteoglycan synthesis was studied by metabolic [35]sulphate labelling followed by autoradiography, and electrophoretic analysis of extracted proteoglycans. Northern analyses were performed to determine the mRNA levels of type II collagen, aggrecan, and Sox9 in cartilage samples. Results: Radiosynovectomy had no major effect on the histological appearance of articular cartilage in mature rabbits, whereas more fibrillation was seen in [166Ho]FHMA radiosynovectomised knee joints of growing rabbits two months after treatment, but not after one year. Radiosynovectomy did not cause changes in the glycosaminoglycan content of cartilage or in the synthesis or chemical structure of proteoglycans. No radiosynovectomy related changes were seen in the mRNA levels of type II collagen, whereas a transient down regulation of aggrecan and Sox9 mRNA levels was seen in young rabbits two months after [166Ho]FHMA radiosynovectomy. Conclusions: [166Ho]FHMA radiosynovectomy caused no obvious chondrocyte damage or osteoarthritic changes in mature rabbits, but in growing rabbits some transient radiation induced effects were seen—for example, mild cartilage fibrillation and down regulation of cartilage-specific genes. PMID:12480668

  16. Clinical effects of transcatheter hepatic arterial embolization with holmium-166 poly(l-lactic acid) microspheres in healthy pigs

    PubMed Central

    Nijsen, J. F. W.; de Wit, T. C.; Seppenwoolde, J. H.; Krijger, G. C.; Seevinck, P. R.; Huisman, A.; Zonnenberg, B. A.; van den Ingh, T. S. G. A. M.; van het Schip, A. D.

    2008-01-01

    Purpose The aim of this study is to evaluate the toxicity of holmium-166 poly(l-lactic acid) microspheres administered into the hepatic artery in pigs. Methods Healthy pigs (20–30 kg) were injected into the hepatic artery with holmium-165-loaded microspheres (165HoMS; n = 5) or with holmium-166-loaded microspheres (166HoMS; n = 13). The microspheres’ biodistribution was assessed by single-photon emission computed tomography and/or MRI. The animals were monitored clinically, biochemically, and (166HoMS group only) hematologically over a period of 1 month (165HoMS group) or over 1 or 2 months (166HoMS group). Finally, a pathological examination was undertaken. Results After microsphere administration, some animals exhibited a slightly diminished level of consciousness and a dip in appetite, both of which were transient. Four lethal adverse events occurred in the 166HoMS group due either to incorrect administration or comorbidity: inadvertent delivery of microspheres into the gastric wall (n = 2), preexisting gastric ulceration (n = 1), and endocarditis (n = 1). AST levels were transitorily elevated post-166HoMS administration. In the other blood parameters, no abnormalities were observed. Nuclear scans were acquired from all animals from the 166HoMS group, and MRI scans were performed if available. In pigs from the 166HoMS group, atrophy of one or more liver lobes was frequently observed. The actual radioactivity distribution was assessed through ex vivo 166mHo measurements. Conclusion It can be concluded that the toxicity profile of HoMS is low. In pigs, hepatic arterial embolization with 166HoMS in amounts corresponding with liver-absorbed doses of over 100 Gy, if correctly administered, is not associated with clinically relevant side effects. This result offers a good perspective for upcoming patient trials. PMID:18330569

  17. Clinical effects of transcatheter hepatic arterial embolization with holmium-166 poly(L-lactic acid) microspheres in healthy pigs.

    PubMed

    Vente, M A D; Nijsen, J F W; de Wit, T C; Seppenwoolde, J H; Krijger, G C; Seevinck, P R; Huisman, A; Zonnenberg, B A; van den Ingh, T S G A M; van het Schip, A D

    2008-07-01

    The aim of this study is to evaluate the toxicity of holmium-166 poly(L-lactic acid) microspheres administered into the hepatic artery in pigs. Healthy pigs (20-30 kg) were injected into the hepatic artery with holmium-165-loaded microspheres ((165)HoMS; n=5) or with holmium-166-loaded microspheres ((166)HoMS; n=13). The microspheres' biodistribution was assessed by single-photon emission computed tomography and/or MRI. The animals were monitored clinically, biochemically, and ((166)HoMS group only) hematologically over a period of 1 month ((165)HoMS group) or over 1 or 2 months ((166)HoMS group). Finally, a pathological examination was undertaken. After microsphere administration, some animals exhibited a slightly diminished level of consciousness and a dip in appetite, both of which were transient. Four lethal adverse events occurred in the (166)HoMS group due either to incorrect administration or comorbidity: inadvertent delivery of microspheres into the gastric wall (n=2), preexisting gastric ulceration (n=1), and endocarditis (n=1). AST levels were transitorily elevated post-(166)HoMS administration. In the other blood parameters, no abnormalities were observed. Nuclear scans were acquired from all animals from the (166)HoMS group, and MRI scans were performed if available. In pigs from the (166)HoMS group, atrophy of one or more liver lobes was frequently observed. The actual radioactivity distribution was assessed through ex vivo (166m)Ho measurements. It can be concluded that the toxicity profile of HoMS is low. In pigs, hepatic arterial embolization with (166)HoMS in amounts corresponding with liver-absorbed doses of over 100 Gy, if correctly administered, is not associated with clinically relevant side effects. This result offers a good perspective for upcoming patient trials.

  18. DNA/chitosan electrostatic complex.

    PubMed

    Bravo-Anaya, Lourdes Mónica; Soltero, J F Armando; Rinaudo, Marguerite

    2016-07-01

    Up to now, chitosan and DNA have been investigated for gene delivery due to chitosan advantages. It is recognized that chitosan is a biocompatible and biodegradable non-viral vector that does not produce immunological reactions, contrary to viral vectors. Chitosan has also been used and studied for its ability to protect DNA against nuclease degradation and to transfect DNA into several kinds of cells. In this work, high molecular weight DNA is compacted with chitosan. DNA-chitosan complex stoichiometry, net charge, dimensions, conformation and thermal stability are determined and discussed. The influence of external salt and chitosan molecular weight on the stoichiometry is also discussed. The isoelectric point of the complexes was found to be directly related to the protonation degree of chitosan. It is clearly demonstrated that the net charge of DNA-chitosan complex can be expressed in terms of the ratio [NH3(+)]/[P(-)], showing that the electrostatic interactions between DNA and chitosan are the main phenomena taking place in the solution. Compaction of DNA long chain complexed with low molar mass chitosan gives nanoparticles with an average radius around 150nm. Stable nanoparticles are obtained for a partial neutralization of phosphate ionic sites (i.e.: [NH3(+)]/[P(-)] fraction between 0.35 and 0.80).

  19. Targeting of liver tumour in rats by selective delivery of holmium-166 loaded microspheres: a biodistribution study.

    PubMed

    Nijsen, F; Rook, D; Brandt, C; Meijer, R; Dullens, H; Zonnenberg, B; de Klerk, J; van Rijk, P; Hennink, W; van het Schip, F

    2001-06-01

    Intra-arterial administration of beta-emitting particles that become trapped in the vascular bed of a tumour and remain there while delivering high doses, represents a unique approach in the treatment of both primary and metastatic liver tumours. Studies on selective internal radiation therapy of colorectal liver metastases using yttrium-90 glass microspheres have shown encouraging results. This study describes the biodistribution of 40-microm poly lactic acid microspheres loaded with radioactive holmium-166, after intra-arterial administration into the hepatic artery of rats with implanted liver tumours. Radioactivity measurements showed >95% retention of injected activity in the liver and its resident tumour. The average activity detected in other tissues was < or =0.1%ID/g, with incidental exceptions in the lungs and stomach. Very little 166Ho activity was detected in kidneys (<0.1%ID/g), thereby indicating the stability of the microspheres in vivo. Tumour targeting was very effective, with a mean tumour to liver ratio of 6. 1+/-2.9 for rats with tumour (n=15) versus 0.7+/-0.5 for control rats (n=6; P<0.001). These ratios were not significantly affected by the use of adrenaline. Histological analysis showed that five times as many large (>10) and medium-sized (4-9) clusters of microspheres were present within tumour and peritumoural tissue, compared with normal liver. Single microspheres were equally dispersed throughout the tumour, as well as normal liver parenchyma.

  20. Holmium-166 poly(L-lactic acid) microsphere radioembolisation of the liver: technical aspects studied in a large animal model.

    PubMed

    Vente, M A D; de Wit, T C; van den Bosch, M A A J; Bult, W; Seevinck, P R; Zonnenberg, B A; de Jong, H W A M; Krijger, G C; Bakker, C J G; van het Schip, A D; Nijsen, J F W

    2010-04-01

    To assess the accuracy of a scout dose of holmium-166 poly(L-lactic acid) microspheres ((166)Ho-PLLA-MS) in predicting the distribution of a treatment dose of (166)Ho-PLLA-MS, using single photon emission tomography (SPECT). A scout dose (60 mg) was injected into the hepatic artery of five pigs and SPECT acquired. Subsequently, a 'treatment dose' was administered (540 mg) and SPECT, computed tomography (CT) and magnetic resonance imaging (MRI) of the total dose performed. The two SPECT images of each animal were compared. To validate quantitative SPECT an ex vivo liver was instilled with (166)Ho-PLLA-MS and SPECT acquired. The liver was cut into slices and planar images were acquired, which were registered to the SPECT image. Qualitatively, the scout dose and total dose images were similar, except in one animal because of catheter displacement. Quantitative analysis, feasible in two animals, tended to confirm this similarity (r(2) = 0.34); in the other animal the relation was significantly better (r(2) = 0.66). The relation between the SPECT and planar images acquired from the ex vivo liver was strong (r(2) = 0.90). In the porcine model a scout dose of (166)Ho-PLLA-MS can accurately predict the biodistribution of a treatment dose. Quantitative (166)Ho SPECT was validated for clinical application.

  1. Intratumoral Administration of Holmium-166 Acetylacetonate Microspheres: Antitumor Efficacy and Feasibility of Multimodality Imaging in Renal Cancer

    PubMed Central

    Elschot, Mattijs; Seevinck, Peter R.; Beekman, Freek J.; de Jong, Hugo W. A. M.; Uges, Donald R. A.; Kosterink, Jos G. W.; Luijten, Peter R.; Hennink, Wim E.; van het Schip, Alfred D.; Bosch, J. L. H. Ruud; Nijsen, J. Frank W.

    2013-01-01

    Purpose The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microspheres (166HoAcAcMS). This new technique locally ablates renal tumors through high-energy beta particles, while the gamma rays allow for nuclear imaging and the paramagnetism of holmium allows for MRI. Methods 166HoAcAcMS were administered intratumorally in orthotopic renal tumors (Balb/C mice). Post administration CT, SPECT and MRI was performed. At several time points (2 h, 1, 2, 3, 7 and 14 days) after MS administration, tumors were measured and histologically analyzed. Holmium accumulation in organs was measured using inductively coupled plasma mass spectrometry. Results 166HoAcAcMS were successfully administered to tumor bearing mice. A striking near-complete tumor-control was observed in 166HoAcAcMS treated mice (0.10±0.01 cm3 vs. 4.15±0.3 cm3 for control tumors). Focal necrosis and inflammation was present from 24 h following treatment. Renal parenchyma outside the radiated region showed no histological alterations. Post administration CT, MRI and SPECT imaging revealed clear deposits of 166HoAcAcMS in the kidney. Conclusions Intratumorally administered 166HoAcAcMS has great potential as a new local treatment of renal tumors for surgically unfit patients. In addition to strong cancer control, it provides powerful multimodality imaging opportunities. PMID:23320070

  2. Radiotherapeutic bandage based on electrospun polyacrylonitrile containing holmium-166 iron garnet nanoparticles for the treatment of skin cancer.

    PubMed

    Munaweera, Imalka; Levesque-Bishop, Daniel; Shi, Yi; Di Pasqua, Anthony J; Balkus, Kenneth J

    2014-12-24

    Radiation therapy is used as a primary treatment for inoperable tumors and in patients that cannot or will not undergo surgery. Radioactive holmium-166 ((166)Ho) is a viable candidate for use against skin cancer. Nonradioactive holmium-165 ((165)Ho) iron garnet nanoparticles have been incorporated into a bandage, which, after neutron-activation to (166)Ho, can be applied to a tumor lesion. The (165)Ho iron garnet nanoparticles ((165)HoIG) were synthesized and introduced into polyacrylonitrile (PAN) polymer solutions. The polymer solutions were then electrospun to produce flexible nonwoven bandages, which are stable to neutron-activation. The fiber mats were characterized using scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis and inductively coupled plasma mass spectrometry. The bandages are stable after neutron-activation at a thermal neutron-flux of approximately 3.5 × 10(12) neutrons/cm(2)·s for at least 4 h and 100 °C. Different amounts of radioactivity can be produced by changing the amount of the (165)HoIG nanoparticles inside the bandage and the duration of neutron-activation, which is important for different stages of skin cancer. Furthermore, the radioactive bandage can be easily manipulated to irradiate only the tumor site by cutting the bandage into specific shapes and sizes that cover the tumor prior to neutron-activation. Thus, exposure of healthy cells to high energy β-particles can be avoided. Moreover, there is no leakage of radioactive material after neutron activation, which is critical for safe handling by healthcare professionals treating skin cancer patients.

  3. Intratumoral administration of holmium-166 acetylacetonate microspheres: antitumor efficacy and feasibility of multimodality imaging in renal cancer.

    PubMed

    Bult, Wouter; Kroeze, Stephanie G C; Elschot, Mattijs; Seevinck, Peter R; Beekman, Freek J; de Jong, Hugo W A M; Uges, Donald R A; Kosterink, Jos G W; Luijten, Peter R; Hennink, Wim E; van het Schip, Alfred D; Bosch, J L H Ruud; Nijsen, J Frank W; Jans, Judith J M

    2013-01-01

    The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microspheres ((166)HoAcAcMS). This new technique locally ablates renal tumors through high-energy beta particles, while the gamma rays allow for nuclear imaging and the paramagnetism of holmium allows for MRI. (166)HoAcAcMS were administered intratumorally in orthotopic renal tumors (Balb/C mice). Post administration CT, SPECT and MRI was performed. At several time points (2 h, 1, 2, 3, 7 and 14 days) after MS administration, tumors were measured and histologically analyzed. Holmium accumulation in organs was measured using inductively coupled plasma mass spectrometry. (166)HoAcAcMS were successfully administered to tumor bearing mice. A striking near-complete tumor-control was observed in (166)HoAcAcMS treated mice (0.10±0.01 cm(3) vs. 4.15±0.3 cm(3) for control tumors). Focal necrosis and inflammation was present from 24 h following treatment. Renal parenchyma outside the radiated region showed no histological alterations. Post administration CT, MRI and SPECT imaging revealed clear deposits of (166)HoAcAcMS in the kidney. Intratumorally administered (166)HoAcAcMS has great potential as a new local treatment of renal tumors for surgically unfit patients. In addition to strong cancer control, it provides powerful multimodality imaging opportunities.

  4. Surefire infusion system versus standard microcatheter use during holmium-166 radioembolization: study protocol for a randomized controlled trial.

    PubMed

    van den Hoven, Andor F; Prince, Jip F; Bruijnen, Rutger C G; Verkooijen, Helena M; Krijger, Gerard C; Lam, Marnix G E H; van den Bosch, Maurice A A J

    2016-10-25

    An anti-reflux catheter (ARC) may increase the tumor absorbed dose during radioembolization (RE) by elimination of particle reflux and its effects on hemodynamics. Since the catheter is fixed in a centro-luminal position, it may also increase the predictive accuracy of a scout dose administration before treatment. The purpose of the SIM trial is to compare the effects of ARC use during RE with holmium-166 ((166)Ho) microspheres in patients with colorectal liver metastases (CRLM), with the use of a standard end-hole microcatheter. A within-patient randomized controlled trial (RCT) will be conducted in 25 patients with unresectable chemorefractory liver-dominant CRLM. Study participants will undergo a (166)Ho scout dose procedure in the morning and a therapeutic procedure in the afternoon. The ARC will be randomly allocated to the left/right hepatic artery, and a standard microcatheter will be used in the contralateral artery. SPECT/CT imaging will be performed for quantitative analyses of the microsphere distribution directly after the scout and treatment procedure. Baseline and follow-up investigations include (18)F-FDG-PET + liver CT, clinical and laboratory examinations. The primary endpoint is the comparison of tumor to non-tumor (T/N) activity ratio in both groups. Secondary endpoints include comparisons of mean absorbed dose in tumors and healthy liver tissue, infusion efficiency, the predictive value of (166)Ho scout dose for tumor response. In the entire cohort, a dose-response relationship, clinical toxicity, and overall survival will be assessed. The sample was determined for the expectation that the ARC will increase the T/N ratio by 25 % (mean T/N ratio 2.0 vs. 1.6). The SIM trial is a within-patient RCT that will assess whether (166)Ho RE treatment can be optimized by using an ARC. The SIM trial is registered at clinicaltrials.gov ( NCT02208804 ). Registered on 31 July 2014.

  5. Holmium-166 radioembolization for the treatment of patients with liver metastases: design of the phase I HEPAR trial

    PubMed Central

    2010-01-01

    Background Intra-arterial radioembolization with yttrium-90 microspheres ( 90Y-RE) is an increasingly used therapy for patients with unresectable liver malignancies. Over the last decade, radioactive holmium-166 poly(L-lactic acid) microspheres ( 166Ho-PLLA-MS) have been developed as a possible alternative to 90Y-RE. Next to high-energy beta-radiation, 166Ho also emits gamma-radiation, which allows for imaging by gamma scintigraphy. In addition, Ho is a highly paramagnetic element and can therefore be visualized by MRI. These imaging modalities are useful for assessment of the biodistribution, and allow dosimetry through quantitative analysis of the scintigraphic and MR images. Previous studies have demonstrated the safety of 166Ho-PLLA-MS radioembolization ( 166Ho-RE) in animals. The aim of this phase I trial is to assess the safety and toxicity profile of 166Ho-RE in patients with liver metastases. Methods The HEPAR study (Holmium Embolization Particles for Arterial Radiotherapy) is a non-randomized, open label, safety study. We aim to include 15 to 24 patients with liver metastases of any origin, who have chemotherapy-refractory disease and who are not amenable to surgical resection. Prior to treatment, in addition to the standard technetium-99m labelled macroaggregated albumin ( 99mTc-MAA) dose, a low radioactive safety dose of 60-mg 166Ho-PLLA-MS will be administered. Patients are treated in 4 cohorts of 3-6 patients, according to a standard dose escalation protocol (20 Gy, 40 Gy, 60 Gy, and 80 Gy, respectively). The primary objective will be to establish the maximum tolerated radiation dose of 166Ho-PLLA-MS. Secondary objectives are to assess tumour response, biodistribution, performance status, quality of life, and to compare the 166Ho-PLLA-MS safety dose and the 99mTc-MAA dose distributions with respect to the ability to accurately predict microsphere distribution. Discussion This will be the first clinical study on 166Ho-RE. Based on preclinical studies

  6. Holmium-166 radioembolization for the treatment of patients with liver metastases: design of the phase I HEPAR trial.

    PubMed

    Smits, Maarten L J; Nijsen, Johannes F W; van den Bosch, Maurice A A J; Lam, Marnix G E H; Vente, Maarten A D; Huijbregts, Julia E; van het Schip, Alfred D; Elschot, Mattijs; Bult, Wouter; de Jong, Hugo W A M; Meulenhoff, Pieter C W; Zonnenberg, Bernard A

    2010-06-15

    Intra-arterial radioembolization with yttrium-90 microspheres ( 90Y-RE) is an increasingly used therapy for patients with unresectable liver malignancies. Over the last decade, radioactive holmium-166 poly(L-lactic acid) microspheres ( 166Ho-PLLA-MS) have been developed as a possible alternative to 90Y-RE. Next to high-energy beta-radiation, 166Ho also emits gamma-radiation, which allows for imaging by gamma scintigraphy. In addition, Ho is a highly paramagnetic element and can therefore be visualized by MRI. These imaging modalities are useful for assessment of the biodistribution, and allow dosimetry through quantitative analysis of the scintigraphic and MR images. Previous studies have demonstrated the safety of 166Ho-PLLA-MS radioembolization ( 166Ho-RE) in animals. The aim of this phase I trial is to assess the safety and toxicity profile of 166Ho-RE in patients with liver metastases. The HEPAR study (Holmium Embolization Particles for Arterial Radiotherapy) is a non-randomized, open label, safety study. We aim to include 15 to 24 patients with liver metastases of any origin, who have chemotherapy-refractory disease and who are not amenable to surgical resection. Prior to treatment, in addition to the standard technetium-99m labelled macroaggregated albumin ( 99mTc-MAA) dose, a low radioactive safety dose of 60-mg 166Ho-PLLA-MS will be administered. Patients are treated in 4 cohorts of 3-6 patients, according to a standard dose escalation protocol (20 Gy, 40 Gy, 60 Gy, and 80 Gy, respectively). The primary objective will be to establish the maximum tolerated radiation dose of 166Ho-PLLA-MS. Secondary objectives are to assess tumour response, biodistribution, performance status, quality of life, and to compare the 166Ho-PLLA-MS safety dose and the 99mTc-MAA dose distributions with respect to the ability to accurately predict microsphere distribution. This will be the first clinical study on 166Ho-RE. Based on preclinical studies, it is expected that 166Ho

  7. Holmium-166 radioembolisation in patients with unresectable, chemorefractory liver metastases (HEPAR trial): a phase 1, dose-escalation study.

    PubMed

    Smits, Maarten L J; Nijsen, Johannes F W; van den Bosch, Maurice A A J; Lam, Marnix G E H; Vente, Maarten A D; Mali, Willem P T M; van Het Schip, Alfred D; Zonnenberg, Bernard A

    2012-10-01

    The efficacy of radioembolisation for the treatment of liver tumours depends on the selective distribution of radioactive microspheres to tumorous tissue. The distribution of holmium-166 ((166)Ho) poly(L-lactic acid) microspheres can be visualised in vivo by both single-photon-emission CT (SPECT) and MRI. In this phase 1 clinical trial, we aimed to assess the safety and the maximum tolerated radiation dose (MTRD) of (166)Ho-radioembolisation in patients with liver metastases. Between Nov 30, 2009, and Sept 19, 2011, patients with unresectable, chemorefractory liver metastases were enrolled in the Holmium Embolization Particles for Arterial Radiotherapy (HEPAR) trial. Patients were treated with intra-arterial (166)Ho-radioembolisation in cohorts of three patients, with escalating aimed whole-liver absorbed doses of 20, 40, 60, and 80 Gy. Cohorts were extended to a maximum of six patients if dose-limiting toxicity occurred. Patients were assigned a dose in the order of study entry, with dose escalation until dose-limiting toxicity was encountered in at least two patients of a dose cohort. Clinical or laboratory toxicities were scored according to the National Cancer Institute's Common Terminology Criteria for Adverse Events version 3.0. The primary endpoint was the MTRD. Analyses were per protocol. This study is registered with ClinicalTrials.gov, number NCT01031784. 15 patients underwent (166)Ho-radioembolisation at doses of 20 Gy (n=6), 40 Gy (n=3), 60 Gy (n=3), and 80 Gy (n=3). Mean estimated whole-liver absorbed doses were 18 Gy (SD 2) for the 20 Gy cohort, 35 Gy (SD 1) for the 40 Gy cohort, 58 Gy (SD 3) for the 60 Gy cohort, and 73 Gy (SD 4) for the 80 Gy cohort. The 20 Gy cohort was extended to six patients because of the occurrence of dose-limiting toxicity in one patient (pulmonary embolism). In the 80 Gy cohort, dose-limiting toxicity occurred in two patients: grade 4 thrombocytopenia, grade 3 leucopenia, and grade 3 hypoalbuminaemia in one patient, and

  8. Quantification of holmium-166 loaded microspheres: estimating high local concentrations using a conventional multiple gradient echo sequence with S₀-fitting.

    PubMed

    van de Maat, Gerrit H; Seevinck, Peter R; Bos, Clemens; Bakker, Chris J G

    2012-06-01

    To provide a best estimate of the R 2* value and hence of the local concentration of highly paramagnetic holmium-166 loaded microspheres (HoMS) in voxels for which R 2* cannot be characterized by conventional fitting of multigradient echo (MGE) data because of fast signal decay due to high local concentrations. A postprocessing method, S(0)-fitting, was implemented in a conventional R 2* fitting method that is used for quantification of HoMS. S(0)-fitting incorporates the estimated initial amplitude of the free induction decay (FID) curve, S(0), of neighboring voxels into the fitting procedure for voxels for which the conventional algorithm failed. The method was applied to HoMS in vitro and ex vivo in a rabbit liver. The performance of the S(0)-fitting method was evaluated by comparing results qualitatively and quantitatively with results obtained with quantitative ultrashort TE imaging (qUTE). Applying S(0)-fitting provided a best estimate for R 2* up to a value of about 2300 s(-1) compared with a maximum value of about 1000 s(-1) that could be characterized using conventional fitting. A good agreement was observed both qualitatively and quantitatively for in vitro experiments as well as for ex vivo rabbit liver experiments between results obtained with S(0)-fitting and results obtained with qUTE imaging. S(0)-fitting is a postprocessing method that can provide a best estimate of high R 2* values that cannot be characterized by conventional relaxometry. The method can be applied to conventional MGE datasets and was shown to be beneficial for quantification of high local concentrations of holmium-loaded microspheres. Copyright © 2012 Wiley Periodicals, Inc.

  9. Preparation and characterization modified chitosan by polyelectrolyte complexation

    NASA Astrophysics Data System (ADS)

    Zuhannisa, Nugraheni, Prihati Sih; Budhijanto, Wiratni; Kusumastuti, Yuni

    2017-03-01

    The polyelectrolyte complexes (PECs) of chitosan with various polysaccharides such as alginate, carrageenan, Arabic gum, carboxymethylcellulose (CMC), pectin, and glucomannan were prepared and characterized. The complexation was performed by addition of polysaccharide solution as crosslinking agent into chitosan solution (0.01% and 2 %) under magnetic stirring. The size of the obtained modified chitosan was analyzed by Particle Size Analyzer (PSA). The turbidity and pH were measured to observe the stability of the modified chitosan during the storage. The stability of the complexes was investigated at room temperature (37°C) for 3 weeks. The existence of glucomannan and arabic gum resulted PECs when it reacted with the chitosan solution using ratio 1:1. The changed crosslinker resulted a hydrogel after it blended. The obtained PECs could be affected by the ratio between chitosan and polysaccharide and the molecular weight of both polymers. The crosslinker concentration gave a significantly influenced the obtained particle size at the chitosan concentration 0.01 % and 2%.

  10. Evaluation of structural and functional properties of chitosan-chlorogenic acid complexes.

    PubMed

    Wei, Zihao; Gao, Yanxiang

    2016-05-01

    The objectives of the present study were to first synthesize chitosan-chlorogenic acid (CA) covalent complex and then compare structural and functional properties between chitosan-CA covalent complex and physical complex. First, chitosan-CA covalent complex was synthesized and its total phenolic content was as high as 276.5 ± 6.2 mg/g. Then structural and functional properties of chitosan-CA covalent and physical complexes were analyzed. The covalent reaction induced formation of both amide and ester bonds in chitosan. Data of X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicated that the complexations of CA changed crystallinity and morphology of chitosan, and covalent complexation induced a larger change of physical structure than physical complexation. In terms of functional properties, chitosan-CA covalent complex exhibited better thermal stability than physical complex in terms of antioxidant activity, and the viscosity of chitosan was significantly increased by covalent modification.

  11. Gels of sodium alginate‒chitosan interpolyelectrolyte complexes

    NASA Astrophysics Data System (ADS)

    Brovko, O. S.; Palamarchuk, I. A.; Val'chuk, N. A.; Chukhchin, D. G.; Bogolitsyn, K. G.; Boitsova, T. A.

    2017-08-01

    Aspects of the formation of gels of interpolyelectrolyte complexes (IPECs) based on sodium alginate (NaAlg) and chitosan are studied. The effect the conditions of synthesis and complex composition have on the morphological structure and functional properties of these complexes is examined. It is established that complexation in this system proceeds according to a mechanism of electrostatic interaction between the oppositely charged carboxylic groups of the L-hyaluronic acid pyranose cycles of NaAlg proximal polymer chains and chitosan's amino groups, along with a multitude of hydrogen bonds and dispersion forces. We show that the mechanism of IPEC formation is strongly influenced by the conformational state of a lyophilizing component that is present in the system in excess. The inner surfaces of cryogels based on NaAlg‒chitosan IPECs is found to be strongly influenced by the degree of conversion between the parental polyelectrolytes. The most developed mesoporous structure is obtained when a denser gel forms in the system.

  12. Complex coacervation of soybean protein isolate and chitosan.

    PubMed

    Huang, Guo-Qing; Sun, Yan-Ting; Xiao, Jun-Xia; Yang, Jian

    2012-11-15

    The formation of coacervates between soybean protein isolate (SPI) and chitosan was investigated by turbidimetric analysis and coacervate yield determination as a function of pH, temperature, time, ionic strength, total biopolymer concentration (TB(conc)) and protein to polysaccharide ratio (R(SPI/Chitosan)). The interaction between SPI and chitosan yielded a sponge-like coacervate phase and the optimum conditions for their coacervation were pH 6.0-6.5, a temperature of 25 °C, and a R(SPI/Chitosan) ratio of four independently of TB(conc). NaCl inhibited the complexation between the two biopolymers. Fourier transform infrared spectroscopy (FTIR) revealed that the coacervates were formed through the electrostatic interaction between the carboxyl groups of SPI (-COO(-)) and the amine groups of chitosan (-NH(3)(+)), however hydrogen bonding was also involved in the coacervation. Differential scanning calorimetry (DSC) thermograms indicated raised denaturation temperature and network thermal stability of SPI in the coacervates due to SPI-chitosan interactions. Scanning electron microscopy (SEM) micrographs revealed that the coacervates had a porous network structure interspaced by heterogeneously sized vacuoles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Study of polyelectrolyte complexes of chitosan and sulfoethyl cellulose

    SciTech Connect

    Baklagina, Yu. G. Kononova, S. V.; Petrova, V. A.; Kruchinina, E. V.; Nud'ga, L. A.; Romanov, D. P.; Klechkovskaya, V. V.; Orekhov, A. S.; Bogomazov, A. V.; Arkhipov, S. N.

    2013-03-15

    The complexing of polycation chitosan and polyanion sulphoethyl cellulose during the formation of polyelectrolyte simplex membranes using the layer-by-layer deposition of a solution of one polyion on a gel-like film of another one has been studied. The structural characteristics of the multilayer composites and their components have been analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray microanalysis. A technique is proposed for studying the structure of surface layers of thin polymer films (15-20 {mu}m) using a portable DIFREI-401 diffractometer. It is shown that the sequence of layer deposition during the formation of membrane films does not affect their structural characteristics. The interaction between positively charged chitosan groups (-NH{sub 3}{sup +}) and negatively charged sulfoethyl cellulose groups (-SO{sub 3}{sup -}) during the growth of polyelectrolyte complexes results in a packing of chitosan chains in the multilayer film.

  14. Chitosan-Copper (II) complex as antibacterial agent: synthesis, characterization and coordinating bond- activity correlation study

    NASA Astrophysics Data System (ADS)

    Mekahlia, S.; Bouzid, B.

    2009-11-01

    The antimicrobial activity of chitosan is unstable and sensitive to many factors such as molecular weight. Recent investigations showed that low molecular weight chitosan exhibited strong bactericidal activities compared to chitosan with high molecular weight. Since chitosan degradation can be caused by the coordinating bond, we attempt to synthesize and characterize the chitosan-Cu (II) complex, and thereafter study the coordinating bond effect on its antibacterial activity against Salmonella enteritidis. Seven chitosan-copper complexes with different copper contents were prepared and characterized by FT-IR, UV-vis, XRD and atomic absorption spectrophotometry (AAS). Results indicated that for chitosan-Cu (II) complexes with molar ratio close to 1:1, the inhibition rate reached 100%.

  15. Forming and immunological properties of some lipopolysaccharide-chitosan complexes.

    PubMed

    Yermak, Irina M; Davidova, Viktoria N; Gorbach, Vladimir I; Luk'yanov, Pavel A; Solov'eva, Tamara F; Ulmer, Arthur J; Buwitt-Beckmann, Ute; Rietschel, Ernst T; Ovodov, Yury S

    2006-01-01

    The complex formation of lipopolysaccharide (LPS) with chitosan (Ch) was demonstrated using sedimentation velocity analysis in the analytical ultracentrifuge, centrifugation in glycerol gradient and isopicnic centrifugation in cesium chloride. An addition of Ch to the Escherichia coli and Yersinia pseudotuberculosis LPS solutions was found to result in formation of the stable LPS-Ch complexes. The interaction is a complicated process and depends on time and reaction temperature, as well as on the molecular weight of chitosan. A stable LPS-Ch complex could be formed only after preliminary incubation of the initial components at an elevated temperature (37 degrees C). It should be noted that process of LPS complexation with Ch is accompanied by additional dissociating of LPS. The complex formation was shown to be a result not only of ionic binding, but also of other types of interactions. The interaction of Ch with LPS was shown to modulate significantly the biological activity of LPS. The LPS-Ch complex (1:5 w/w) was shown to possess much lower toxicity in a comparison with the parent LPS at injection to mice in the similar concentration. The LPS-Ch complex was shown to maintain an ability to induce of IL-8 and TNF, but induction of IL-8 and TNF biosynthesis by the LPS-Ch complex was lower than that by the parent LPS. The complex LPS-Ch, similarly to the parent LPS, was found stimulated the formation of the IL-8 in the dose-dependent manner in the human embryonal kidney cells (HEK 293 cells) transfected with TLR4 in combination with MD2.

  16. Effect of chitosan type on protein and water recovery efficiency from surimi wash water treated with chitosan-alginate complexes.

    PubMed

    Wibowo, Singgih; Velazquez, Gonzalo; Savant, Vivek; Torres, J Antonio

    2007-02-01

    Previous research has shown that soluble protein recovery by chitosan (Chi) complexes with polyanions such as alginate (Alg) is more effective than using chitosan alone. In this study, Chi-Alg complexes were used to recover soluble proteins from surimi wash water (SWW) slightly acidified to pH 6. Six Chi samples differing in molecular weight (MW) and degree of deacetylation (DD) were used at 20, 40 and 100mg/L SWW Chi-Alg complexes prepared with a Chi:Alg mixing ratio previously optimized (MR=0.2). FTIR analysis of the solids recovered revealed the three characteristic amide bands observed in the same region for untreated SWW confirming protein adsorption by Chi-Alg. The superior effectiveness of Chi complexes was confirmed but differences among chitosan types could not be correlated to MW and DD. Experimental Chi samples with 94%, 93%, 75% and 93% DD and 22, 47, 225 and 3404 x 10(3)Da, respectively, showed 73-76% protein adsorption while a commercial chitosan sample with 84% DD and 3832 x 10(3)Da had 74-83% protein adsorption. An experimental chitosan, SY-1000 with 94% DD and 1.5 x 10(6)Da, showed the highest protein adsorption (79-86%) and turbidity reduction (85-92%) when used at 20mg/L SWW.

  17. Chitosan/alginate complexes for vaginal delivery of chlorhexidine digluconate.

    PubMed

    Abruzzo, A; Bigucci, F; Cerchiara, T; Saladini, B; Gallucci, M C; Cruciani, F; Vitali, B; Luppi, B

    2013-01-16

    Chitosan/alginate complexes were prepared at different polycation/polyanion molar ratios and freeze-dried vaginal inserts were obtained for chlorhexidine digluconate local delivery in genital infections. Complex yield, FT-IR spectra, and TGA thermograms were studied to confirm the interaction between the two polyions. The influence of different complexes on physical handling, morphology, and drug distribution in the samples were evaluated by friability test, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), respectively. In vitro water-uptake, mucoadhesion and release tests were performed as well as microbiological tests toward pathogenic vaginal microorganisms. The results showed that the selection of suitable chitosan/alginate molar ratio and drug loading allowed modulate insert ability to hydrate, adhere to the mucosa, and release chlorhexidine digluconate. The insert containing an excess of alginate was found to be the best performing formulation and showed good antimicrobial activity toward the pathogens Candida albicans and Escherichia coli. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. [Removal of lead from aqueous solutions by complexation-ultrafiltration with chitosan].

    PubMed

    Xie, Zhang-Wang; Shao, Jia-Hui; He, Yi-Liang

    2010-06-01

    Polyethersulphone (PES) membrane was chosen and chitosan was used as complexing agent to remove lead ions by complexation-ultrafiltration. Effects of solution pH, Pb2+/chitosan ratio, ionic strength and Ca2+ on the rejection coefficient of lead were investigated. The effect of concentration time on lead rejection coefficient and membrane flux was also studied. The value of pH was found to be the key parameter in the process of complexation-ultrafiltration. The rejection coefficient of lead goes high to over 99% at pH 6.0 with the Pb2+/chitosan ratio 0.25. The increase of ionic strength and Ca2+ is not beneficial to the lead removal by complexation-ultrafiltration. The chitosan-metal complex was acidified and then the chitosan was regenerated by diafiltration. The regenerated chitosan was used to remove Pb2+ by complexation-ultrafiltration, and the rejection coefficient of lead was found to be 96.2%, which shows no significant difference with that obtained on the fresh chitosan. Results showed that complexation-ultrafiltration can effectively remove lead from aqueous solutions and chitosan can be effectively regenerated.

  19. Complex film of chitosan and carboxymethyl cellulose nanofibers.

    PubMed

    Kawasaki, Takuma; Nakaji-Hirabayashi, Tadashi; Masuyama, Kazuhira; Fujita, Satoshi; Kitano, Hiromi

    2016-03-01

    A polymer film composed of a mixture of chitosan (Ch) and carboxymethyl cellulose sodium salt (CMC) nanofibers was deposited on a glass surface. The thin film of the Ch-CMC mixture obtained was stable, and fibroblast adhesion to the film was lowest when the weight ratio of Ch to CMC was 4:6. The ζ-potential and contact angle of the mixture film indicated that a polyion complex of Ch and CMC was formed. The mechanical strength of the film composed of Ch-CMC nanofiber complexes was much higher than that of the film composed of Ch-water-soluble CMC complexes (non-nanofiber), likely because the entanglement of nanofibers was enhanced by electrostatic attractions. These results indicate that the charge-neutralized nanofiber film was highly effective in suppressing cell adhesion and therefore is a promising material for biomedical applications.

  20. Structural and antimicrobial properties of irradiated chitosan and its complexes with zinc

    NASA Astrophysics Data System (ADS)

    Khan, Azam; Mehmood, Shaukat; Shafiq, Muhammad; Yasin, Tariq; Akhter, Zareen; Ahmad, Shabir

    2013-10-01

    The aim of this research was to evaluate the structural and antimicrobial properties of irradiated chitosan and its complexes with zinc. Chitosan having a molecular weight (Mη) of 220 kDa was exposed to gamma rays in dry, wet and solution forms. The chitosan-zinc complexes were prepared by varying the Mη of chitosan and Zn content. Viscometeric analysis revealed a sharp decrease in the Mη of chitosan irradiated in solution form even at lower doses compared with the dry and wet forms. X-ray diffraction patterns demonstrated variation in the crystallinity of chitosan upon exposure to gamma rays. The antibacterial response of the irradiated chitosan and its complexes against gram-positive and gram-negative bacteria demonstrated wide spectrum of effective antimicrobial activities, which increased with the dose. Additionally, the complexes exhibited excellent antifungal activity with no growth of Aspergallious fumigatus and Fusarium solani even after two weeks. These results suggested that the irradiated chitosan and its complexes with Zn can be used as antimicrobial additives for various applications.

  1. Chitosan

    PubMed Central

    Smith, Alan; Perelman, Michael; Hinchcliffe, Michael

    2014-01-01

    The nasal route is attractive for the delivery of vaccines in that it not only offers an easy to use, non-invasive, needle-free alternative to more conventional parenteral injection, but it also creates an opportunity to elicit both systemic and (crucially) mucosal immune responses which may increase the capability of controlling pathogens at the site of entry. Immune responses to “naked” antigens are often modest and it is widely accepted that incorporation of an adjuvant is a prerequisite for the achievement of clinically effective nasal vaccines. Many existing adjuvants are sub-optimal or unsuitable because of local toxicity or poor enhancement of immunogenicity. Chitosan, particularly chitosan salts, have now been used in several preclinical and clinical studies with good tolerability, excellent immune stimulation and positive clinical results across a number of infections. Particularly significant evidence supporting chitosan as an adjuvant for nasal vaccination comes from clinical investigations on a norovirus vaccine; this demonstrated the ability of chitosan (ChiSys®), when combined with monophosphoryl lipid, to evoke robust immunological responses and confer protective immunity following (enteral) norovirus challenge. This article summarizes the totality of the meaningful information (including key unpublished data) supporting the development of chitosan-adjuvanted vaccines. PMID:24346613

  2. Complexation of chitosan with surfactant like ionic liquids: molecular interactions and preparation of chitosan nanoparticles.

    PubMed

    Bharmoria, Pankaj; Singh, Tejwant; Kumar, Arvind

    2013-10-01

    Interactions and behavior of chitosan (Ch) with surface active ionic liquids (ILs)- 1-butyl-3-methylimidazolium octylsulfate, [C4mim][C8OSO3] or 3-methyl-1-octylimidazolium chloride, [C8mim][Cl]-have been probed at the air solution interface and in the bulk in aqueous media at pH 3.0 using a multi-technique approach, viz. tensiometry, conductometry, turbidimetry, dynamic light scattering (DLS), and atomic force microscopy (AFM). At the interface, a strong complexation is observed in Ch-[C4mim][C8OSO3] system. Bulk [C4mim][C8OSO3] interacts with Ch to form Ch-[C4mim][C8OSO3] complexes which precipitate out at higher IL concentrations, whereas comparatively weaker Ch-[C8mim][Cl] complexes remain solubilized in the solution. DLS measurements showed that the Ch chains contract before the cmc and expands after the cmc upon interaction with both the ILs. Interaction of ILs with Ch resulted in facile preparation of uniformly distributed Ch nanoparticles with good sphericity and control which have been verified using DLS, SEM, AFM, and fluorescence microscopy. The present study provides an understanding of forces governing the complexation behavior of Ch with surface active ILs and their efficacy to produce Ch nanoparticles. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Complexation-triggerable liposome mixed with silk protein and chitosan.

    PubMed

    Hong, Yeon-Ji; Kim, Jin-Chul

    2015-01-01

    Complexation-triggerable liposomes were prepared by modifying the surface of egg phosphatidylcholine (EPC) liposomes with hydrophobicized silk fibroin (HmSF) and hydrophobicized chitosan (HmCh). Maximum complexation, determined by measuring the diameter of complexation, was found when the ratio of HmSF to HmCh was 14:1, so they were immobilized on the surface of liposomes at the same ratio. The degree of fluorescence quenching of calcein in liposomal suspension was as high as 68% when the ratio of surface modifier (HmSF + HmCh) to EPC was 1:15. When the ratio was increased to 1:5, the degree of quenching decreased to 32%, indicating the inefficient formation of liposome. Liposome mixed with the surface modifier was multi-lamellar vesicle on TEM photo. And, the mean diameter was larger than those of liposome mixed with either HmSF or HmCh, possibly due to insoluble complex on the liposomal surface. The liposome exhibited a pH-sensitive release and triggered the release at pH 5.5 and 6.0. It is believed that complexation is responsible for the promoted release at those pH values.

  4. Influence of structural features of carrageenan on the formation of polyelectrolyte complexes with chitosan.

    PubMed

    Volod'ko, A V; Davydova, V N; Glazunov, V P; Likhatskaya, G N; Yermak, I M

    2016-03-01

    The polyelectrolyte complexes (PEC) of carrageenans (CG)-κ-, κ/β-, λ-and x-CG with chitosan were obtained. The formation of PEC was detected by Fourier-transform infrared (FTIR) spectroscopy and by centrifugation in a Percoll gradient. The influence of the structural peculiarities of CG on its interaction with chitosan was studied. The results of centrifugation showed that x-CG with a high degree of sulphation (SD) was completely bound to chitosan, unlike low SD κ-CG and κ/β-CG. Binding constant values showed there was a high affinity of CG for chitosan. CG with flexible macromolecule conformation and high SD exhibited the greatest binding affinity for chitosan. The full-atomic 3D-structures of the PEC κ-CG: chitosan in solution have been obtained by the experiments in silico for the first time. The amino groups of chitosan make the largest contribution to the energy of the complex formation by means of hydrogen and ionic bonds. The most probable complexes have stoichiometries of 1:1 and 1:1.5.

  5. Design of Chitosan and Its Water Soluble Derivatives-Based Drug Carriers with Polyelectrolyte Complexes

    PubMed Central

    Wu, Qing-Xi; Lin, Dong-Qiang; Yao, Shan-Jing

    2014-01-01

    Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail. PMID:25532565

  6. Carboxymethyl chitosan/clay nanocomposites and their copper complexes: Fabrication and property.

    PubMed

    Huang, Yongcan; Huang, Jiancong; Cai, Jihai; Lin, Wensheng; Lin, Qixuan; Wu, Fangchengyuan; Luo, Jiwen

    2015-12-10

    To obtain environmentally friendly antifouling agent, an effort was made to intercalate carboxymethyl chitosan into the interlayer of organic montmorillonite to prepare carboxymethyl chitosan/organic montmorillonite nanocomposites and their copper complexes. In comparison, carboxymethyl chitosan-copper complexes were also obtained. Their structures were characterized by X-ray diffaraction, transmittance electron microscopy and Fourier transform infrared, and their thermal behavior and antimicrobial activity were discussed. The results revealed that the interlayer distance of carboxymethyl chitosan/organic montmorillonite nanocomposites enlarged with the increasing mass ratio of carboxymethyl chitosan to organic montmorillonite, when the mass ratio was at 20:1, the layer spacing of carboxymethyl chitosan/organic montmorillonite nanocomposites reached the maximum of 3.68 nm. As compared to other samples, carboxymethyl chitosan/organic montmorillonite-copper nanocomposites showed much higher thermal stability and inhibitory activity against Escherichia coli, the lowest minimum inhibition concentration was only 0.0003125% (w/v). The study provides a new method to find novel antifouling agent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Chelating, film-forming, and coagulating ability of the chitosan-glucan complex from Aspergillus niger industrial wastes.

    PubMed

    Muzzarelli, R A; Tanfani, F; Scarpini, G

    1980-04-01

    Waste mycelia of Aspergillus niger from a citric acid production plant are simply treated with boiling 30-40% NaOH aqueous solutions for 4-6 hr to obtain the insoluble chitosan-glucan complex whose infrared, ESR, and x-ray diffraction spectra are reported. A number of transition- and post-transition-metal ions are chelated and collected by chitosan-glucan with higher yields than by animal chitosan. Immediate flocculation occurs upon mixing chitosan-glucan dispersions with alginate and polymolybdate solutions. Membranes are also obtained from chitosan-glucan dispersions in acetic acid or in chloral and dimethyl formamide mixtures.

  8. Lyophilized Chitosan/xanthan Polyelectrolyte Complex Based Mucoadhesive Inserts for Nasal Delivery of Promethazine Hydrochloride

    PubMed Central

    G Dehghan, Mohamed Hassan; Marzuka, Marzuka

    2014-01-01

    The objective of this investigation was the development of chitosan/xanthan polyelectrolyte complex based mucoadhesive nasal insert of promethazine hydrochloride a drug used in the treatment of motion sickness. A 32 factorial design was applied for preparing chitosan/xanthan polyelectrolyte complex and to study the effect of independent variables i.e. concentration of xanthan [X1] and concentration of chitosan [X2] on various responses i.e. viscosity of polyelectrolyte complex solution, water uptake of nasal inserts (at pH 2, 5.5, 7.4), bioadhesion potential of nasal inserts and in-vitro drug release at Q6h through nasal inserts. FTIR and DSC analysis were carried out to confirm complex formation and on loaded and unloaded nasal insert to investigate any drug excipient interaction. The nasal inserts were also characterized by powder X-ray diffractometry (PXRD) and Scanning electron microscopy (SEM) and for ex-vivo permeation studies. The results show that higher amount of xanthan in polyelectrolyte complexes with respect to higher amount of chitosan retarded in-vitro drug release. The water uptake behaviour of nasal insert was strongly influenced by pH of the medium and by polycation/ polyanion concentration. The investigation verifies the formation of polyelectrolyte complexes formation between chitosan and xanthan at pH values in the vicinity of pKa intervals of the two polymers and confirms their potential for the nasal delivery of promethazine hydrochloride. PMID:25276178

  9. Polyelectrolyte complex of carboxymethyl gum katira-chitosan: Preparation and characterization.

    PubMed

    Minkal; Ahuja, Munish; Bhatt, D C

    2017-08-26

    In the present study polyelectrolyte complex between carboxymethyl gum katira and chitosan were prepared and evaluated for drug delivery using ofloxacin as model drug. The carboxymethyl gum katira-chitosan polyelectrolyte complex was characterized by FTIR, DSC, TGA, DTG, XRD and SEM. The influence of concentration of CMGK/CH and drug loading (%) on yield (%) and drug entrapment (%) was studied using response surface methodology. The result of the study revealed that increasing the relative proportion of CMGK/CH in carboxymethyl gum katira-chitosan polyelectrolyte complex decreases the % yield and increases the % drug entrapment. The optimal calculated parameters were polymer ratio (CMGK/CH) 2.13 and drug loading 50 (%w/w). The optimized batch of carboxymethyl gum katira-chitosan polyelectrolyte complex had yield of 69.04%, entrapment efficiency of ofloxacin 84.86%. Further, the optimized batch of carboxymethyl gum katira-chitosan polyelectrolyte complex releases ofloxacin 84.32% following Higuchi's square-root kinetics. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Preparation of an extended-release matrix tablet using chitosan/Carbopol interpolymer complex.

    PubMed

    Park, Sung-Hyun; Chun, Myung-Kwan; Choi, Hoo-Kyun

    2008-01-22

    A chitosan and Carbopol interpolymer complex (IPC) was formed using a precipitation method in an acidic solution. The chitosan and Carbopol IPC was characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and turbidity measurements. FT-IR demonstrated that the IPC formed a complex through an electrostatic interaction between the protonated amine (NH(3)(+)) group of chitosan and the carboxylate (COO(-)) group of Carbopol. DSC indicated the IPC to have different thermal characteristics from chitosan or Carbopol. The turbidity measurement revealed the complexation ratio of IPC between chitosan/Carbopol to be 1/4. A theophylline tablet was prepared using the IPC as a matrix material. The drug release profile from this tablet was similar to that from the HPMC tablet and showed a pH-independent release profile. The mechanisms for drug release from the IPC tablet were diffusional release at pH 6.8 and relaxational release at pH 1.2.

  11. Chitosan Based Polyelectrolyte Complexes as Potential Carrier Materials in Drug Delivery Systems

    PubMed Central

    Hamman, Josias H.

    2010-01-01

    Chitosan has been the subject of interest for its use as a polymeric drug carrier material in dosage form design due to its appealing properties such as biocompatibility, biodegradability, low toxicity and relatively low production cost from abundant natural sources. However, one drawback of using this natural polysaccharide in modified release dosage forms for oral administration is its fast dissolution rate in the stomach. Since chitosan is positively charged at low pH values (below its pKa value), it spontaneously associates with negatively charged polyions in solution to form polyelectrolyte complexes. These chitosan based polyelectrolyte complexes exhibit favourable physicochemical properties with preservation of chitosan’s biocompatible characteristics. These complexes are therefore good candidate excipient materials for the design of different types of dosage forms. It is the aim of this review to describe complexation of chitosan with selected natural and synthetic polyanions and to indicate some of the factors that influence the formation and stability of these polyelectrolyte complexes. Furthermore, recent investigations into the use of these complexes as excipients in drug delivery systems such as nano- and microparticles, beads, fibers, sponges and matrix type tablets are briefly described. PMID:20479980

  12. [Stabilization of alkaline proteinase and cellulases via complex formation with chitosan for use as detergent components].

    PubMed

    Kudriashova, E V; Vasil'eva, I S; Zorov, I N; Sinitsyn, A P; Levashov, A V

    2009-01-01

    An effective approach to the stabilization of hydrolytic enzymes (alkaline proteinase and cellulases) via the complex formation with chitosan for their further use as detergent components has been developed. Interaction with chitosan results in a 35-50% increase in the level of catalytic activity of the enzymes after incubation for 60 min under the conditions of detergent use (alkaline pH, increased temperature, the presence of anionic surfactants) as compared to the system in the absence of chitosan both due to the enzyme stabilization and the increase of the starting level of catalytic activity. A twofold decrease of the enzyme inactivation constant is observed under the aforementioned conditions in the case of alkaline proteinase. In the case of cellulase preparation, the method for the control of the concentration of the active enzyme in the system modeling synthetic detergents has been suggested. The method is based on the enzymatic destruction of the stabilizing agent, chitosan, by enzymes of the cellulase complex. The destruction of chitosan removed the stabilizing effect, thus resulting in the inactivation of cellulases. The developed approaches allow for the widening of the field of the possible application of enzymes as detergent components.

  13. The influence of chitosan valence on the complexation and transfection of DNA: the weaker the DNA-chitosan binding the higher the transfection efficiency.

    PubMed

    Alatorre-Meda, Manuel; Taboada, Pablo; Hartl, Florian; Wagner, Tobias; Freis, Michael; Rodríguez, Julio R

    2011-01-01

    The DNA-chitosan polyplexes have attracted for some years now the attention of physical-chemists and biologists for their potential use in gene therapy, however, the correlation between the physicochemical properties of these polyplexes with their transfection efficiency remains still unclear. In a recent paper we demonstrated by means of DLS that the DNA-chitosan complexation is favored at acidic conditions considering that fewer amounts of chitosan were required to compact the DNA. As a second study, in the present work we analyze the influence of chitosan valence on the complexation and transfection of DNA. Three chitosans of different molecular weights (three different valences) are characterized as gene carriers at 25°C and pH 5 over a wide range of chitosan-Nitrogen to DNA-Phosphate molar ratios, N/P, by means of conductometry, electrophoretic mobility, isothermal titration calorimetry (ITC), transmission electron microscopy (TEM), atomic force microscopy (AFM), and β-galactosidase and luciferase expression assays. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Sorption of Cu(II) complexes with ligands tartrate, glycine and quadrol by chitosan.

    PubMed

    Gyliene, Ona; Binkiene, Rima; Butkiene, Rita

    2009-11-15

    The sorption by chitosan in Cu(II) solutions containing tartrate, glycine (amino acetic acid) and quadrol (N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine) as ligands has been investigated. The degree of sorbate removal strongly depends on pH. In solutions containing tartrate almost complete sorption of both Cu(II) and tartrate proceeds in mildly acidic and neutral solutions. The sorption of Cu(II) is also complete in alkaline solutions containing glycine; meanwhile a substantial sorption of glycine proceeds at pH approximately 6. The Cu(II) sorption in solutions containing quadrol is insignificant. Any sorption of quadrol does not proceed in the whole range of pH investigated. The investigations under equilibrium conditions showed that the Cu(II) sorption from tartrate containing solutions obeys Freundlich equation and in solutions containing glycine and quadrol it fits Langmuir equation. Supposedly, Cu(II) sorption onto chitosan proceeds with formation of amino complexes onto the surface of chitosan; the sorption of tartrate proceeds as electrostatic as well as with formation of amide bonds. Applying of electrolysis enables a complete removal of sorbed Cu(II) and ligands without changes in physical and chemical properties of chitosan. This is confirmed by sorption ability of regenerated chitosan, measurements of its molecular weight, the deacetylation degree and FT-IR spectra.

  15. Chitosan/pectin/gum Arabic polyelectrolyte complex: process-dependent appearance, microstructure analysis and its application.

    PubMed

    Tsai, Ruei-Yi; Chen, Pin-Wen; Kuo, Ting-Yun; Lin, Che-Min; Wang, Da-Ming; Hsien, Tzu-Yang; Hsieh, Hsyue-Jen

    2014-01-30

    Novel chitosan/pectin/gum Arabic polyelectrolyte complex (PEC) solutions and membranes with various compositions were prepared for biomedical applications. The appearance of the PEC solutions, either clear or turbid, was process-dependent and depended on how the three components were dissolved and mixed. The addition of gum Arabic to the chitosan and pectin significantly decreased the viscosities of the resultant PEC solutions due to the formation of globe-like microstructures that was accompanied by network-like microstructures and other molecular entanglements. The mechanical strength and hydrophilicity of the PEC membranes manufactured from the PEC solutions, especially for a weight ratio of 84/8/8 (chitosan/pectin/gum Arabic), were enhanced compared to pure chitosan membranes. Moreover, the use of the 84/8/8 PEC membranes as a drug carrier exhibited steady and fairly complete release of a drug (insulin) for 6h. Based on these promising results, the chitosan/pectin/gum Arabic PEC membranes have great potential in controlled drug release applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Chitosan-poly(acrylic acid) polyelectrolyte complex membranes: preparation, characterization and permeability studies.

    PubMed

    de Oliveira, H C L; Fonseca, J L C; Pereira, M R

    2008-01-01

    Polyelectrolyte complex (PEC) membranes were obtained by mixing solutions of two polymers of opposite charges, chitosan (Chi) and poly(acrylic acid) PAA. Three membranes were obtained: one made of pure chitosan and two membranes with chitosan mixed with PAA at a ratio of 95:5 (one prepared using PAA solution in 3.5% formic acid, named ChiPAA3.5, and another one using a PAA solution in 10% formic acid, named ChiPAA10). The membranes were characterized by swelling experiments, FT-IR spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical properties and permeability studies in relation to a drug model (sodium sulphamerazine). The calculation of degree of ionization showed that the lower the formic acid concentration was, the higher the PAA dissociation degree. Polyelectrolyte complex formation was characterized by FT-IR. Water uptake results showed that PEC membranes were more hydrophilic than pure chitosan, ChiPAA3.5 being the most. Morphological analysis by SEM and AFM showed that PAA addition changed the membranes morphology, especially for ChiPAA3.5. Mechanical properties indicated that PEC membranes were more rigid than pure chitosan membranes and that the morphology has an influence on tensile strength values. Permeability values decreased with complex formation and were lower for ChiPAA10 than ChiPAA3.5. However, as drug concentration was increased, the difference between the two complex membranes disappeared. The results were discussed considering the drug-membrane interactions. Diffusion coefficient values indicated that ChiPAA3.5 had a higher drug retention capacity than ChiPAA10.

  17. The chitosan-gelatin (bio)polyelectrolyte complexes formation in an acidic medium.

    PubMed

    Voron'ko, Nicolay G; Derkach, Svetlana R; Kuchina, Yuliya A; Sokolan, Nina I

    2016-03-15

    The interaction of cationic polysaccharide chitosan and gelatin accompanied by the stoichiometric (bio)polyelectrolyte complexes formation has been studied by the methods of capillary viscometry, UV and FTIR spectroscopy and dispersion of light scattering. Complexes were formed in the aqueous phase, with pH being less than the isoelectric point of gelatin (pIgel). The particle size of the disperse phase increases along with the growth of the relative viscosity in comparison with sols of the individual components-polysaccharide and gelatin. Possible models and mechanism of (bio)polyelectrolyte complexes formation have been discussed. It was shown that the complex formation takes place not only due to the hydrogen bonds, but also due to the electrostatic interactions between the positively charged amino-groups of chitosan and negatively charged amino acid residues (glutamic Glu and aspartic Asp acids) of gelatin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Blood compatibility of chitosan/heparin complex surface modified ePTFE vascular graft

    NASA Astrophysics Data System (ADS)

    Zhu, A. P.; Ming, Zhang; Jian, Shen

    2005-03-01

    Vascular grafts made of expanded polytetrafluoroethylene (ePTFE) are widely employed in vascular reconstructive surgery. While they are successful as replacements for large-diameter blood vessels, ePTFE vascular grafts are unsuitable for small-diameter ones because when the internal diameters of the graft are less than 6 mm, they are found to fail without exception due to blood clot formation. To reduce platelets adhesion onto the ePTFE vascular graft, a novel method of binding of chitosan/heparin (CS/Hp) complex to the surface of vascular graft was developed. The binding of chitosan was achieved by irradiating with ultraviolet light the azide modified chitosan that was coated on the ePTFE surface. By forming complex with this coating of chitosan, heparin was then bonded to the ePTFE surface. In vitro blood compatibility experiments showed that CS/Hp surface-modified ePTFE vascular grafts exhibited markedly reduced platelets adhesion. The outstanding performance of these grafts was further demonstrated by the in vivo experiments, in which they were found to be still unclogged two weeks post-implantation into dog veins.

  19. Synthesis, characterization and antibacterial studies of ruthenium(III) complexes derived from chitosan schiff base.

    PubMed

    Vadivel, T; Dhamodaran, M

    2016-09-01

    Chitosan can be modified chemically by condensation reaction of deacetylated chitosan with aldehyde in homogeneous phase. This condensation is carried by primary amine (NH2) with aldehyde (CHO) to form corresponding schiff base. The chitosan biopolymer schiff base derivatives are synthesized with substituted aldehydes namely 4-hydroxy-3-methoxy benzaldehyde, 2-hydroxy benzaldehyde, and 2-hydroxy-3-methoxy benzaldehyde, becomes a complexing agent or ligand. The Ruthenium(III) complexes were obtained by complexation of Ruthenium with schiff base ligands and this product exhibits as an excellent solubility and more biocompatibility. The novel series of schiff base Ruthenium(III) complexes are characterized by Elemental analysis, FT-IR spectroscopy, and Thermo-gravimetric analysis (TGA). The synthesized complexes have been subjected to antibacterial study. The antibacterial results indicated that the antibacterial activity of the complexes were more effective against Gram positive and Gram negative pathogenic bacteria. These findings are giving suitable support for developing new antibacterial agent and expand our scope for applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Characterization of self-assembled polyelectrolyte complex nanoparticles formed from chitosan and pectin.

    PubMed

    Birch, Nathan P; Schiffman, Jessica D

    2014-04-01

    Chronic wounds continue to be a global healthcare concern. Thus, the development of new nanoparticle-based therapies that treat multiple symptoms of these "non-healing" wounds without encouraging antibiotic resistance is imperative. One potential solution is to use chitosan, a naturally antimicrobial polycation, which can spontaneously form polyelectrolyte complexes when mixed with a polyanion in appropriate aqueous conditions. The requirement of at least two different polymers opens up the opportunity for us to form chitosan complexes with an additional functional polyanion. In this study, chitosan:pectin (CS:Pec) nanoparticles were synthesized using an aqueous spontaneous ionic gelation method. Systematically, a number of parameters, polymer concentration, addition order, mass ratio, and solution pH, were explored and their effect on nanoparticle formation was determined. The size and surface charge of the particles were characterized, as well as their morphology using transmission electron microscopy. The effect of polymer concentration and addition order on the nanoparticles was found to be similar to that of other chitosan:polyanion complexes. The mass ratio was tuned to create nanoparticles with a chitosan shell and a controllable positive zeta potential. The particles were stable in a pH range from 3.5 to 6.0 and lost stability after 14 days of storage in aqueous media. Due to the high positive surface charge of the particles, the innate properties of the polysaccharides used, and the harmless disassociation of the polyelectrolytes, we suggest that the development of these CS:Pec nanoparticles offers great promise as a chronic wound healing platform.

  1. Chitosan-polycarbophil complexes in swellable matrix systems for controlled drug release.

    PubMed

    Lu, Z; Chen, W; Hamman, J H

    2007-10-01

    A prerequisite for progress in the design of novel drug delivery systems is the development of excipients that are capable of fulfilling multifunctional roles such as controlling the release of the drug according to the therapeutic needs. Although several polymers have been utilised in the development of specialised drug delivery systems, their scope in dosage form design can be enlarged through combining different polymers. When a polymer is cross-linked or complexed with an oppositely charged polyelectrolyte, a three-dimensional network is formed in which the drug can be incorporated to control its release. The swelling properties and release kinetics of two model drugs with different water solubilities (i.e. diltiazem and ibuprofen) from monolithic matrix tablets consisting of an interpolyelectrolyte complex between chitosan and polycarbophil are reported. Matrix tablets consisting of this polymeric complex without drug or excipients exhibited extremely high swelling properties that are completely reversible upon drying. The drug release from matrix systems with different formulations depended on the concentration of the chitosan-polycarbophil interpolyelectrolyte complex and approached zero order release kinetics for both model drugs. The chitosan-polycarbophil interpolyelectrolyte complex has demonstrated a high potential as an excipient for the production of swellable matrix systems with controlled drug release properties.

  2. Electrospun chitosan-alginate nanofibers with in situ polyelectrolyte complexation for use as tissue engineering scaffolds.

    PubMed

    Jeong, Sung In; Krebs, Melissa D; Bonino, Christopher A; Samorezov, Julia E; Khan, Saad A; Alsberg, Eben

    2011-01-01

    Electrospun natural biopolymers are of great interest in the field of regenerative medicine due to their unique structure, biocompatibility, and potential to support controlled release of bioactive agents and/or the growth of cells near a site of interest. The ability to electrospin chitosan and alginate to form polyionic complexed nanofibrous scaffolds was investigated. These nanofibers crosslink in situ during the electrospinning process, and thus do not require an additional chemical crosslinking step. Although poly(ethylene oxide) (PEO) is required for the electrospinning, it can be subsequently removed from the nanofibers simply by incubating in water for a few days, as confirmed by attenuated total reflectance Fourier transform infrared. Solutions that allowed uniform nanofiber formation were found to have viscosities in the range of 0.15-0.7 Pa·s and conductivities below 4 mS/cm for chitosan-PEO and below 2.2 mS/cm for alginate-PEO. The resultant nanofibers both before and after PEO extraction were found to be uniform and on the order of 100 nm as determined by scanning electron microscopy. The dynamic rheological properties of the polymer mixtures during gelation indicated that the hydrogel mixtures with low storage moduli provided uniform nanofiber formation without beaded structures. Increased amounts of chitosan in the PEO-extracted chitosan-alginate nanofibers resulted in a lower swelling ratio. Additionally, these nanofibrous scaffolds exhibit increased cell adhesion and proliferation compared to those made of alginate alone, due to the presence of the chitosan, which promotes the adsorption of serum proteins. Thus, these nanofibrous scaffolds formed purely via ionic complexation without toxic crosslinking agents have great potential for guiding cell behavior in tissue regeneration applications.

  3. Polyelectrolyte complex of carboxymethyl starch and chitosan as protein carrier: oral administration of ovalbumin.

    PubMed

    Assaad, Elias; Blemur, Lindsay; Lessard, Martin; Mateescu, Mircea Alexandru

    2012-01-01

    A novel carboxymethyl starch (CMS)/chitosan polyelectrolyte complex (PEC) was proposed as an excipient for oral administration of ovalbumin. The dissolution of ovalbumin from monolithic tablets (200 mg, 2.1 × 9.6 mm, 50% loading) obtained by direct compression was studied. When CMS was used as an excipient, more than 70% of the loaded ovalbumin remained undigested after 1 h of incubation in simulated gastric fluid (SGF) with pepsin. The complete dissolution, after transfer of tablets into simulated intestinal fluid (SIF) with pancreatin, occurred within a total time of about 6 h. Higher protection (more than 90% stability in SGF) and longer dissolution (more than 13 h) were obtained with 50% CMS/50% chitosan physical mixture or with PEC excipients. A lower proportion of chitosan was needed for PEC than for the CMS/chitosan mixture to obtain a similar dissolution profile. The high protection against digestion by pepsin, the various release times and the mucoadhesion properties of these excipients based on CMS favor the development of suitable carriers for oral vaccinations.

  4. Cupreous Complex-Loaded Chitosan Nanoparticles for Photothermal Therapy and Chemotherapy of Oral Epithelial Carcinoma.

    PubMed

    Lin, Min; Wang, Dandan; Liu, Shuwei; Huang, Tingting; Sun, Bin; Cui, Yan; Zhang, Daqi; Sun, Hongchen; Zhang, Hao; Sun, Hui; Yang, Bai

    2015-09-23

    Electron transition materials on the basis of transition metal ions usually possess higher photothermal transduction efficiency but lower extinction ability, which have not been considered as efficient photothermal agents for therapeutic applications. In this work, we demonstrate a facile and feasible approach for enhancing 808 nm photothermal conversion effect of d orbits transition Cu(II) ions by forming Cu-carboxylate complexes. The coordination with carboxylate groups greatly enlarges the splitting energy gap of Cu(II) and the capability of electron transition, thus enhancing the extinction ability in near-infrared region. The cupreous complexes are further loaded in biocompatible and biodegradable polymer nanoparticles (NPs) of chitosan to temporarily lower the toxicity, which allows the photothermal therapy of human oral epithelial carcinoma (KB) cells in vitro and KB tumors in vivo. Animal experiments indicate the photothermal tumor inhibition rate of 100%. In addition, the gradual degradation of chitosan NPs leads to the release of cupreous complexes, thus exhibiting additional chemotherapeutic behavior in KB tumor treatment. Onefold chemotherapy experiments indicate the tumor inhibition rate of 93.1%. The combination of photothermal therapy and chemotherapy of cupreous complex-loaded chitosan NPs indicates the possibility of inhibiting tumor recurrence.

  5. Implantable biodegradable sponges: effect of interpolymer complex formation of chitosan with gelatin on the release behavior of tramadol hydrochloride.

    PubMed

    Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

    2007-01-01

    The effect of interpolymer complex formation between positively charged chitosan and negatively charged gelatin (Type B) on the release behavior of tramadol hydrochloride from biodegradable chitosan-gelatin sponges was studied. Mixed sponges were prepared by freeze-drying the cross-linked homogenous stable foams produced from chitosan and gelatin solutions where gelatin acts as a foam builder. Generation of stable foams was optimized where concentration, pH of gelatin solution, temperature, speed and duration of whipping process, and, chitosan-gelatin ratio drastically affect the properties and the stability of the produced foams. The prepared sponges were evaluated for their morphology, drug content, and microstructure using scanning electron microscopy, mechanical properties, uptake capacity, drug release profile, and their pharmacodynamic activity in terms of the analgesic effect after implantation in Wistar rats. It was revealed that whipping 7% (w/w) gelatin solution, of pH 5.5, for 15 min at 25 degrees C with a stirring speed of 1000 rpm was the optimum conditions for stable gelatin foam generation. Moreover, homogenous, uniform chitosan-gelatin foam with small air bubbles were produced by mixing 2.5% w/w chitosan solution with 7% w/w gelatin solution in 1:5 ratio. Indeed, polyionic complexation between chitosan and gelatin overcame the drawbacks of chitosan sponge mechanical properties where, pliable, soft, and compressible sponge with high fluid uptake capacity was produced at 25 degrees C and 65% relative humidity without any added plasticizer. Drug release studies showed a successful retardation of the incorporated drug where the t50% values of the dissolution profiles were 0.55, 3.03, and 4.73 hr for cross-linked gelatin, un-cross-linked chitosan-gelatin, and cross-linked chitosan-gelatin sponges, respectively. All the release experiments followed Higuchi's diffusion mechanism over 12 hr. The achieved drug prolongation was a result of a combined effect

  6. Nitrate adsorption from aqueous solution using granular chitosan-Fe3+ complex

    NASA Astrophysics Data System (ADS)

    Hu, Qili; Chen, Nan; Feng, Chuanping; Hu, WeiWu

    2015-08-01

    In the present study, In order to efficiently remove nitrate, granular chitosan-Fe3+ complex with high chemical stability and good environmental adaptation was synthesized through precipitation method and characterized using SEM, XRD, BET and FTIR. The nitrate adsorption performance was evaluated by batch experiments. The results indicated that granular chitosan-Fe3+ complex was an amorphous and mesoporous material. The BET specific surface area and average pore size were 8.98 m2 g-1 and 56.94 Å, respectively. The point of zero charge was obtained at pH 5. The maximum adsorption capacity reached 8.35 mg NO3--N g-1 based on Langmuir-Freundlich model. Moreover, no significant change in the nitrate removal efficiency was observed in the pH range of 3.0-10.0. The adverse influence of sulphate on nitrate removal was the most significant, followed by bicarbonate and fluoride, whereas chloride had slightly adverse effect. Adsorption process followed the pseudo-second-order kinetic model, and the experimental equilibrium data were fitted well with the Langmuir-Freundlich and D-R isotherm models. Thermodynamic parameters revealed that nitrate adsorption was a spontaneous and exothermic process. Granular chitosan-Fe3+ complex could be effectively regenerated by NaCl solution.

  7. Kinetic studies of nitrate removal from aqueous solution using granular chitosan-Fe(III) complex.

    PubMed

    Hu, Qili; Chen, Nan; Feng, Chuanping; Zhang, Jing; Hu, Weiwu; Lv, Long

    2016-01-01

    In the present study, a granular chitosan-Fe(III) complex was prepared as a feasible adsorbent for the removal of nitrate from an aqueous solution. There was no significant change in terms of nitrate removal efficiency over a wide pH range of 3-11. Nitrate adsorption on the chitosan-Fe(III) complex followed the Langmuir-Freundlich isotherm model. In order to more accurately reflect adsorption and desorption behaviors at the solid/solution interface, kinetic model I and kinetic model II were proposed to simulate the interfacial process in a batch system. Nitrate adsorption on the chitosan-Fe(III) complex followed the pseudo-first-order kinetic model and kinetic model I. The proposed half-time could provide useful information for optimizing process design. Adsorption and desorption rate constants obtained from kinetic model I and kinetic model II were beneficial to understanding the interfacial process and the extent of adsorption reaction. Kinetic model I and kinetic model II implied that nitrate uptake exponentially approaches a limiting value.

  8. New polyelectrolyte complex from pectin/chitosan and montmorillonite clay.

    PubMed

    da Costa, Marcia Parente Melo; de Mello Ferreira, Ivana Lourenço; de Macedo Cruz, Mauricio Tavares

    2016-08-01

    A new nanocomposite hydrogel was prepared by forming a crosslinked hybrid polymer network based on chitosan and pectin in the presence of montmorillonite clay. The influence of clay concentration (0.5 and 2% wt) as well as polymer ratios (1:1, 1:2 and 2:1) was investigated carefully. The samples were characterized by different techniques: transmission and scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, swelling degree and compression test. Most samples presented swelling degree above 1000%, which permits characterizing them as superabsorbent material. Images obtained by transmission electron microscopy showed the presence of clay nanoparticles into hydrogel. The hydrogels' morphological properties were evaluated by scanning electron microscope in high and low-vacuum. The micrographs showed that the samples presented porous. The incorporation of clay produced hydrogels with differentiated morphology. Thermogravimetric analysis results revealed that the incorporation of clay in the samples provided greater thermal stability to the hydrogels. The compression resistance also increased with addition of clay.

  9. Sulfadiazine—Chitosan Conjugates and Their Polyelectrolyte Complexes with Hyaluronate Destined to the Management of Burn Wounds

    PubMed Central

    Dumitriu, Raluca Petronela; Profire, Lenuta; Nita, Loredana Elena; Dragostin, Oana Maria; Ghetu, Nicolae; Pieptu, Dragoș; Vasile, Cornelia

    2015-01-01

    In the present study polyelectrolyte complexes (PECs) based on new sulfadiazine-chitosan conjugates with sodium hyaluronate have been developed with potential use in treatment of burn wounds. The PECs were chemically characterized using Fourier Transform—Infrared Spectroscopy, Scanning Electon Microscopy and Near Infrared Chemical Imaging Technique. The swelling behavior and in vitro sulfadiazine release were also investigated. The antimicrobial activity was evaluated towards three bacterial strains: Escherichia coli, Listeria monocytogenes and Salmonella thyphymurium. The developed PECs demonstrated their antimicrobial efficiency against tested bacterial strains, the PECs containing sulfadiazine-modified chitosan being more active than PECs containing unmodified chitosan. PMID:28787940

  10. Effect of chitosan molecular weight on the formation of chitosan-pullulanase soluble complexes and their application in the immobilization of pullulanase onto Fe3O4-κ-carrageenan nanoparticles.

    PubMed

    Long, Jie; Xu, Enbo; Li, Xingfei; Wu, Zhengzong; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan; Zhan, Xiaobei

    2016-07-01

    The interactions between pullulanase and chitosans of different molecular weights (Mw) were comprehensively studied, and their applications in pullulanase immobilization onto Fe3O4-κ-carrageenan nanoparticles upon chitosan-pullulanase complexation were also evaluated. Chitosan (CS) complexation with pullulanase was found to be dependent on pH and chitosan Mw. The critical pH of structure-forming events during complexation shifted significantly (p<0.05) to a lower pH with a low Mw chitosan (50kDa) compared to other chitosan types. Binding constants for the chitosan-pullulanase interaction increased in the following order: CS-500complexation exhibited the most desirable enzymatic properties. These results indicated that the complexation behavior was mainly dependent on chitosan Mw. This study presents a technique for the production of immobilized pullulanase upon complexation that exhibits potential for applications in continuous syrup production. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  11. Preparation and chemical and biological characterization of a pectin/chitosan polyelectrolyte complex scaffold for possible bone tissue engineering applications.

    PubMed

    Coimbra, P; Ferreira, P; de Sousa, H C; Batista, P; Rodrigues, M A; Correia, I J; Gil, M H

    2011-01-01

    In this work, porous scaffolds obtained from the freeze-drying of pectin/chitosan polyelectrolyte complexes were prepared and characterized by FTIR, SEM and weight loss studies. Additionally, the cytotoxicity of the prepared scaffolds was evaluated in vitro, using human osteoblast cells. The results obtained showed that cells adhered to scaffolds and proliferated. The study also confirmed that the degradation by-products of pectin/chitosan scaffold are noncytotoxic.

  12. Nanolayer encapsulation of insulin-chitosan complexes improves efficiency of oral insulin delivery

    PubMed Central

    Song, Lei; Zhi, Zheng-liang; Pickup, John C

    2014-01-01

    Current oral insulin formulations reported in the literature are often associated with an unpredictable burst release of insulin in the intestine, which may increase the risk for problematic hypoglycemia. The aim of the study was to develop a solution based on a nanolayer encapsulation of insulin-chitosan complexes to afford sustained release after oral administration. Chitosan/heparin multilayer coatings were deposited onto insulin-chitosan microparticulate cores in the presence of poly(ethylene) glycol (PEG) in the precipitating and coating solutions. The addition of PEG improved insulin loading and minimized an undesirable loss of the protein resulting from redissolution. Nanolayer encapsulation and the formation of complexes enabled a superior loading capacity of insulin (>90%), as well as enhanced stability and 74% decreased solubility at acid pH in vitro, compared with nonencapsulated insulin. The capsulated insulin administered by oral gavage lowered fasting blood glucose levels by up to 50% in a sustained and dose-dependent manner and reduced postprandial glycemia in streptozotocin-induced diabetic mice without causing hypoglycemia. Nanolayer encapsulation reduced the possibility of rapid and erratic falls of blood glucose levels in animals. This technique represents a promising strategy to promote the intestinal absorption efficiency and release behavior of the hormone, potentially enabling an efficient and safe route for oral insulin delivery of insulin in diabetes management. PMID:24833901

  13. Effects of chitosan molecular weight on the physical and dissolution characteristics of amorphous curcumin-chitosan nanoparticle complex.

    PubMed

    Yu, Hong; Nguyen, Minh-Hiep; Hadinoto, Kunn

    2017-09-11

    To investigate the effects of varying molecular weight (MW) of chitosan (CHI) used in the complexation with curcumin (CUR) on the physical and dissolution characteristics of the amorphous CUR-CHI nanoparticle complex produced. Amorphous CUR-CHI nanoparticle complex (or CUR nanoplex in short) recently emerged as a promising bioavailability enhancement strategy of CUR attributed to its fast dissolution, supersaturation generation capability, and simple preparation. Existing CUR nanoplex prepared using low MW CHI, however, exhibited poor colloidal stability during storage. Herein we hypothesized that the colloidal stability could be improved by using CHI of higher MW. The effects of this approach on the nanoplex's other characteristics were simultaneously investigated. The CUR nanoplex was prepared by electrostatically driven self-assembled complexation between CUR and oppositely charged CHI of three different MWs (i.e. low, medium, and high). Besides colloidal stability, the effects of MW variation were investigated for the nanoplex's (1) other physical characteristics (i.e. size, zeta potential, CUR payload, amorphous state stability), (2) preparation efficiency (i.e. CUR utilization rate, yield), and (3) dissolutions under sink condition and supersaturation generation. CUR nanoplex prepared using CHI of high MW exhibited improved colloidal stability, larger size, superior morphology, and prolonged supersaturation generation. On the other hand, the effects of MW variation on the payload, amorphous state stability, preparation efficiency, and dissolution under sink condition were found to be insignificant. Varying MW of CHI used was an effective means to improve certain aspects of the CUR nanoplex characteristics with minimal adverse effects on the others.

  14. Cyclodextrin based ternary system of modafinil: Effect of trimethyl chitosan and polyvinylpyrrolidone as complexing agents.

    PubMed

    Patel, Parth; Agrawal, Y K; Sarvaiya, Jayrajsinh

    2016-03-01

    Modafinil is an approved drug for the treatment of narcolepsy and have a strong market presence in many countries. The drug is widely consumed for off-label uses and currently listed as a restricted drug. Modafinil has very low water solubility. To enhance the aqueous solubility of modafinil by the formation of a ternary complex with Hydroxypropyl-β-cyclodextrin and two hydrophilic polymers was the main objective of the present study. Pyrrolidone (PVP K30) and a water soluble chitosan derivative, trimethyl chitosan (TMC) were studied by solution state and solid state characterization methods for their discriminatory efficiency in solubility enhancement of modafinil. Phase solubility study depicted the highest complexation efficiency (2.22) of cyclodextrin derivative in the presence of TMC compared to the same in the presence of PVP K30 (0.08) and in the absence of any polymer (0.92). FT-IR analysis of binary and ternary complex expressed comparable contribution of both polymers in formation of inclusion complex. The thermal behaviour of binary and ternary complex, involving individual polymers disclosed the influence of TMC on polymorphism of the drug. DSC study revealed efficiency of TMC to prevent conversion of metastable polymorphic form to stable polymorphic form. Ternary complex, involving TMC enhanced water solubility of the drug 1.5 times more compared to the binary complex of the drug whereas PVP K30 reduced the Solubility.

  15. Effect of complexation conditions on microcapsulation of Lactobacillus acidophilus in xanthan-chitosan polyelectrolyte complex gels.

    PubMed

    Chen, He; Song, Yajuan; Liu, Nina; Wan, Hongchang; Shu, Guowei; Liao, Na

    2015-01-01

    Lactobacillus acidophilus has become increasingly popular because of their beneficial effects on health of their host, and are called proboscis. In order to exert beneficial effects for probiotics, they must be able to tolerate the acidic conditions of the stomach environment and the bile in the small intestine. Microencapsulated form has received reasonable attention, since it can protect probiotic organisms against an unfavourable environment, and to allow their release in a viable and metabolically active state in the intestine. The aim of this study was to investigate some factores, such as chitosan solution pH and concentration, xanthan concentration, cell suspension-xanthan ratio, mixed bacteria glue liquid-chitosan ratio, which impacted the process of microencapsulation of L. acidophilus. In this study, L. acidophilus was immobilized with xanthan⁄chitosan gel using extrusion method. The viable counts and encapsulation yield of L. acidophilus encapsulated in different chitosan solution pH (4.5, 5, 5.5 and 6), in different chitosan concentration (0.5%, 0.7%, 0.9% and 1.1%), in different xanthan concentration (0.5%, 0.7%, 0.9% and 1.1%), in different cell suspension-xanthan ratios (1:5, 1:10, 1:15 and 1:20), in different mixed bacteria glue liquid-chitosan ratios (1:3, 1:4, 1:5 and 1:6), have been investigated by single factor experiment method. The optimum conditions of microencapsulated L. acidophilus have been observed. The optimum chitosan solution pH for L. acidophilus was 5.5; the optimum chitosan concentration was 0.9%; the optimum xanthan concentration was 0.7%; the optimum cell suspension-xanthan ratio was 1:10; the optimum mixed bacteria glue liquid-chitosan ratio was 1:3. These results will be helpful to further optimize the process of L. acidophilus microencapsulation, and provide reference for obtaining higher viable counts and entrapped yield of L. acidophilus microcapsules.

  16. Highly efficient detoxification of Cr(VI) by chitosan-Fe(III) complex: process and mechanism studies.

    PubMed

    Shen, Chensi; Chen, Hui; Wu, Shaoshuai; Wen, Yuezhong; Li, Lina; Jiang, Zheng; Li, Meichao; Liu, Weiping

    2013-01-15

    Metal-biopolymer complexes has recently gained significant attention as an effective adsorbent used for the removal of Cr(VI) from water. Unfortunately, despite increasing research efforts in the field of removal efficiency, whether this kind of complex can reduce Cr(VI) to less-toxic Cr(III) and what are the mechanisms of detoxification processes are still unknown. In this study, despite the highly adsorption efficiency (maximum adsorption capacity of 173.1 mg/g in 10 min), the significant improvement of Cr(VI) reduction by chitosan-Fe(III) complex compared with normal crosslinked chitoan has been demonstrated. In addition, the structure of chitosan-Fe(III) complex and its functional groups concerned with Cr(VI) detoxification have been characterized by the powerful spectroscopic techniques X-ray absorption fine structure (XAFS) and X-ray photoelectron spectroscopy (XPS). The XPS spectra indicated that the primary alcoholic function on C-6 served as an electron donor during Cr(VI) reduction and was oxidized to a carbonyl group. The X-ray adsorption near edge spectra (XANES) of the Cr(VI)-treated chitosan-Fe(III) complex revealed the similar geometrical arrangement of Cr species as that in Cr(III)-bound chitosan-Fe(III). Overall, a possible process and mechanism for highly efficient detoxification of Cr(VI) by chitosan-Fe(III) complex has been elucidate. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Recent development of chitosan-based polyelectrolyte complexes with natural polysaccharides for drug delivery.

    PubMed

    Luo, Yangchao; Wang, Qin

    2014-03-01

    Chitosan, as a unique positively charged polysaccharide, has been one of the most popular biopolymers for development of drug delivery systems for various applications, due to its promising properties, including high biocompatibility, excellent biodegradability, low toxicity, as well as abundant availability and low production cost. Since last decade, increasing attention has been attracted by delivery systems fabricated from natural biopolymer-based polyelectrolyte complexes (PEC), formed by electrostatic interactions between two oppositely charged biopolymers. In order to tailor specific applications of chitosan-based PEC drug delivery systems, various forms have been developed in recent years, including nanoparticles, microparticles, beads, tablets, gels, as well as films and membranes. The present review focuses on the recent advances in drug delivery applications of chitosan-based PEC with other natural polysaccharides, including alginate, hyaluronic acid, pectin, carrageenan, xanthan gum, gellan gum, gum arabic, and carboxymethyl cellulose, etc. The fabrication techniques, characterizations, as well as in vitro and in vivo evaluations of each PEC delivery system are discussed in detail. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Modulation of proteins adsorption onto the surface of chitosan complexed with anionic copolymers. Real time analysis by surface plasmon resonance.

    PubMed

    Aguilar, María R; Gallardo, Alberto; Lechuga, Laura M; Calle, Ana; San Román, Julio

    2004-07-14

    The interpolyelectrolyte complex formation between chitosan and anionic polyacrylic derivatives, bearing sulfonic moieties, as well as the protein adsorption onto the chitosan/polyacrylic complexes were studied by surface plasmon resonance (SPR) optical biosensor. This unique technique allows a real time monitoring of different surface molecular interactions with very high sensitivity. The acrylic macromolecules are two families of copolymers of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and, respectively, 2-hydroxyethylmethacrylate (HEMA) and N,N'-dimethylacrylamide (DMAA). The complexation process was evaluated through the SPR measurements resulting from the flowing of polyacrylic aqueous solution over the sensor previously coated with chitosan. The SPR was able to differentiate strong ionic bonds from other weak and reversible interactions. By means of the coated sensors (uncomplexed and the whole series of complexed chitosan), SPR cold be used for a simple "in vitro" protein adsorption analysis, by flowing aqueous solutions of albumin and fibrinogen. While both proteins were adsorbed on the uncomplexed chitosan, the complexed coatings exhibited different and very promising behaviors. In particular, they showed no adsorption or only selective adsorption of albumin.

  19. Water soluble complexes of chitosan-g-MPEG and hyaluronic acid.

    PubMed

    Wu, Jun; Wang, Xuefen; Keum, Jong Kahk; Zhou, Hongwen; Gelfer, Mikhail; Avila-Orta, Carlos-Alberto; Pan, Hui; Chen, Weiliam; Chiao, Shu-Min; Hsiao, Benjamin S; Chu, Benjamin

    2007-03-15

    Novel water soluble, biocompatible, and highly viscoelastic polyelectrolyte complexes were prepared by mixing of positively charged chitosan grafted with poly (ethylene glycol) monomethyl ether (CS-g-MPEG) and negatively charged hyaluronic acid (HA). CS-g-MPEGs having different degrees of substitution were synthesized by reacting chitosan with MPEG-aldehyde. The molecular structure, thermal and rheological properties, as well as biocompatibility of CS-g-MPEG/HA complexes were characterized. Rheological results showed that a small amount of HA could greatly enhance the viscosity of CS-g-MPEG solution. The highest viscosity was obtained when the charge ratio of CS-g-MPEG/HA was close to 1.0. Small-angle X-ray scattering measurements provided some insights into the lamellar structure of the CS-g-MPEG/HA complex. The CS-g-MPEG/HA complex system offers promising potentials in pharmaceutical, cosmetic, and biotechnology applications (e.g., cell scaffold, artificial synovial fluid, and drug/gene delivery medium).

  20. Hydrosoluble 50% N-acetylation-thiolated chitosan complex with cobalt as a pH-responsive renal fibrosis targeting drugs.

    PubMed

    Li, Min; Tan, Lishan; Tang, Liangfeng; Li, Aiqing; Hu, Jianqiang

    2016-07-01

    About 50% N-acetylation-thiolated chitosan possessing good water solubility was modified from commercial low-molecular-weight chitosan. Chitosan performed obvious target toward renal tubular epithelial cells, and bivalent cobalt ions improved the renal fibrosis inflammation significantly. There were many complexation sites on chitosan after being modified with sulfydryl. So sulfydryl played a role of connecting bridge between chitosan and cobalt ions. Then, this N-acetylation-thiolated chitosan cobalt (NTCC) nanocomplex was designed. The nanocomplex showed excellent stability under normal physiological conditions, and cobalt would be released from the biomaterials in acidic environment. As it was affected by inflammation, the pH in renal fibrosis lesion region was acidic. So there was a specific drug release process happening in lesion region. And drug release efficiency was determined by acidity, which demonstrated that lower the acidity, the faster and more the cobalt ion release. When this nanocomplex was intraperitoneally injected into ureter-obstructed mice, obvious attenuation of fibrotic progression was shown. It was demonstrated that NTCC exhibited special renal-targeting capacity and could be chosen as drug for treating renal fibrosis.

  1. Cationic and anionic polyelectrolyte complexes of xylan and chitosan. Interaction with lignocellulosic surfaces.

    PubMed

    Mocchiutti, Paulina; Schnell, Carla N; Rossi, Gerardo D; Peresin, María S; Zanuttini, Miguel A; Galván, María V

    2016-10-05

    Cationic (CatPECs) and anionic (AnPECs) polyelectrolyte complexes from xylan and chitosan were formed, characterized and adsorbed onto unbleached fibers for improving the papermaking properties. They were prepared at a level of 30% of neutralization charge ratio by modifying the order of addition of polyelectrolytes and the ionic strength (0.01N and 0.1N NaCl). The charge density, colloidal stability and particle size of polyelectrolyte complexes (PECs) was measured using polyelectrolyte titration method, Turbiscan and Zetasizer Nano equipments, respectively. All the complexes were stable even after seven days from PEC formation. DRIFT spectra of complexes were also analyzed. The adsorption behavior of them onto cellulose nanofibrils model surfaces was studied using quartz crystal microbalance with dissipation monitoring, and surface plasmon resonance. It was found that the PEC layers were viscoelastic and highly hydrated. Finally, it is shown that the adsorbed PECs onto cellulosic fibers markedly improved the tensile and crushing strengths of paper.

  2. Hypromellose-graft-chitosan and Its Polyelectrolyte Complex as Novel Systems for Sustained Drug Delivery.

    PubMed

    Lai, Wing-Fu; Shum, Ho Cheung

    2015-05-20

    Polyelectrolyte complexes formed between chitosan (CS) and anionic polymers have attracted increasing interest in drug delivery. In this study, CS is copolymerized with hypromellose via a coupling reagent-mediated approach to form a water-soluble, nontoxic CS derivative, namely hypromellose-graft-CS (HC), which is subsequently complexed with carboxymethylcellulose (CMC) to generate a polyampholytic hydrogel. When compared with conventional CS, HC is highly water-soluble across a wide pH range, and has a substantially higher pH buffering capacity to provide a pH-stable environment for delivery of drugs. In addition, the polyelectrolyte complex of HC exhibits a drug encapsulation efficiency of over 90% in all drugs tested, which is 1-2 fold higher than the efficiency attainable by the polyelectrolyte complex of conventional CS, with a 2-3 fold longer duration of sustained drug release. Our results indicate that as a novel polymer, HC has excellent promise for future pharmaceutical applications.

  3. Triclosan loaded electrospun nanofibers based on a cyclodextrin polymer and chitosan polyelectrolyte complex.

    PubMed

    Ouerghemmi, Safa; Degoutin, Stéphanie; Tabary, Nicolas; Cazaux, Frédéric; Maton, Mickaël; Gaucher, Valérie; Janus, Ludovic; Neut, Christel; Chai, Feng; Blanchemain, Nicolas; Martel, Bernard

    2016-11-20

    This work focuses on the relevance of antibacterial nanofibers based on a polyelectrolyte complex formed between positively charged chitosan (CHT) and an anionic hydroxypropyl betacyclodextrin (CD)-citric acid polymer (PCD) complexing triclosan (TCL). The study of PCD/TCL inclusion complex and its release in dynamic conditions, a cytocompatibility study, and finally the antibacterial activity assessment were studied. The fibers were obtained by electrospinning a solution containing chitosan mixed with PCD/TCL inclusion complex. CHT/TCL and CHT-CD/TCL were also prepared as control samples. The TCL loaded nanofibers were analyzed by Scanning Electron Microscopy (SEM), Fourier Transformed Infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD). Nanofibers stability and swelling behavior in aqueous medium were pH and CHT:PCD weight ratio dependent. Such results confirmed that CHT and PCD interacted through ionic interactions, forming a polyelectrolyte complex. A high PCD content in addition to a thermal post treatment at 90°C were necessary to reach a nanofibers stability during 15days in soft acidic conditions, at pH=5.5. In dynamic conditions (USP IV system), a prolonged release of TCL with a reduced burst effect was observed on CHT-PCD polyelectrolyte complex based fibers compared to CHT-CD nanofibers. These results were confirmed by a microbiology study showing prolonged antibacterial activity of the nanofibers against Escherichia coli and Staphylococcus aureus. Such results could be explained by the fact that the stability of the polyelectrolyte CHT-PCD complex in the nanofibers matrix prevented the diffusion of the PCD/triclosan inclusion complex in the supernatant, on the contrary of the similar system including cyclodextrin in its monomeric form.

  4. Intranasal Administration of Novel Chitosan Nanoparticle/DNA Complexes Induces Antibody Response to Hepatitis B Surface Antigen in Mice.

    PubMed

    Lebre, F; Borchard, G; Faneca, H; Pedroso de Lima, M C; Borges, O

    2016-02-01

    The generation of strong pathogen-specific immune responses at mucosal surfaces where hepatitis B virus (HBV) transmission can occur is still a major challenge. Therefore, new vaccines are urgently needed in order to overcome the limitations of existing parenteral ones. Recent studies show that this may be achieved by intranasal immunization. Chitosan has gained attention as a nonviral gene delivery system; however, its use in vivo is limited due to low transfection efficiency mostly related to strong interaction between the negatively charged DNA and the positively charged chitosan. We hypothesize that the adsorption of negatively charged human serum albumin (HSA) onto the surface of the chitosan particles would facilitate the intracellular release of DNA, enhancing transfection activity. Here, we demonstrate that a robust systemic immune response was induced after vaccination using HSA-loaded chitosan nanoparticle/DNA (HSA-CH NP/DNA) complexes. Furthermore, intranasal immunization with HSA-CH NP/DNA complexes induced HBV specific IgA in nasal and vaginal secretions; no systemic or mucosal responses were detected after immunization with DNA alone. Overall, our results show that chitosan-based DNA complexes elicited both humoral and mucosal immune response, making them an interesting and valuable gene delivery system for nasal vaccination against HBV.

  5. Synergistic effects of chitosan-guanidine complexes on enhancing antimicrobial activity and wet-strength of paper.

    PubMed

    Sun, Shengling; An, Qiaozhi; Li, Xu; Qian, Liying; He, Beihai; Xiao, Huining

    2010-07-01

    Chitosan-guanidine complexes were prepared by reacting chitosan and polyhexamethylene guanidine hydrochloride or crosslinked polyhexamethylene guanidine hydrochloride in the presence of sodium tripolyphosphate as a crosslinking agent. The complexes, used as functional additives for paper, synergistically improved wet-strength and antimicrobial activities. In comparison with the control sample, the wet/dry strength ratio of hand-sheets treated with the complexes was increased from 2.65% up to 23.3%. The MIC values of the chitosan-PHGH and chitosan-PHGHE complexes against Escherichia coli were 15.6 and 31.2 microg mL(-1), respectively, thus demonstrating excellent antimicrobial activity. Hand-sheets treated with the complexes exhibited antibacterial activity against E. coli and Staphylococcus aureus. The release of the guanidine polymers included in the complexes was dynamically monitored using UV and the results showed the amount released exceeded 80%. Atomic force microscopy images indicated that the antimicrobial mechanism of the complexes was likely due to membrane damage. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  6. Characteristics of the complexing of chitosan with sodium dodecyl sulfate, according to IR spectroscopy data and quantum-chemical calculations

    NASA Astrophysics Data System (ADS)

    Shilova, S. V.; Romanova, K. A.; Galyametdinov, Yu. G.; Tret'yakova, A. Ya.; Barabanov, V. P.

    2016-06-01

    The complexing of protonated chitosan with dodecyl sulfate ions in water solutions is studied using IR spectroscopy data and quantum-chemical calculations. It is established that the electrostatic interaction between the protonated amino groups of chitosan and dodecyl sulfate ions is apparent in the IR spectrum as a band at 833 cm-1. The need to consider the effect the solvent has on the formation of hydrogen-bound ion pairs [CTS+ ṡ C12H25O 3 - ] is shown via a quantum-chemical simulation of the equilibrium geometry and the energy characteristics of complexing and hydration.

  7. Chitosan-polycarbophil interpolyelectrolyte complex as an excipient for bioadhesive matrix systems to control macromolecular drug delivery.

    PubMed

    Lu, Zhilei; Chen, Weiyang; Hamman, Josias H; Ni, Jian; Zhai, Xiaoling

    2008-01-01

    The in vitro performance of monolithic matrix systems containing the interpolyelectrolyte complex between chitosan and polycarbophil as excipient was evaluated in terms of their swelling, bioadhesive, and drug release properties. The different matrix systems showed excellent swelling properties without erosion, except for the formulation containing the highest quantity chitosan-polycarbophil complex that exhibited surface erosion in addition to swelling. All the different matrix systems exhibited significantly higher bioadhesive properties than the control group. Furthermore, they showed controlled insulin release without an initial burst release effect. However, only the matrix system that exhibited surface erosion in combination with swelling approached zero-order release.

  8. Vaginal inserts based on chitosan and carboxymethylcellulose complexes for local delivery of chlorhexidine: preparation, characterization and antimicrobial activity.

    PubMed

    Bigucci, Federica; Abruzzo, Angela; Vitali, Beatrice; Saladini, Bruno; Cerchiara, Teresa; Gallucci, Maria Caterina; Luppi, Barbara

    2015-01-30

    The aim of this work was to prepare vaginal inserts based on chitosan/carboxymethylcellulose polyelectrolyte complexes for local delivery of chlorhexidine digluconate. Complexes were prepared with different chitosan/carboxymethylcellulose molar ratios at a pH value close to pKa interval of the polymers and were characterized in terms of physico-chemical properties, complexation yield and drug loading. Then complexes were used to prepare inserts as vaginal dosage forms and their physical handling, morphology, water-uptake ability and drug release properties as well as antimicrobial activity toward Candida albicans and Escherichia coli were evaluated. Results confirmed the ionic interaction between chitosan and carboxymethylcellulose and the influence of the charge amount on the complexation yield. Complexes were characterized by high values of drug loading and showed increasing water-uptake ability with the increase of carboxymethylcellulose amount. The selection of appropriate chitosan/carboxymethylcellulose molar ratios allowed to obtain cone-like shaped solid inserts, easy to handle and able to hydrate releasing the drug over time. Finally, the formulated inserts showed antimicrobial activity against common pathogens responsible for vaginal infections.

  9. Defluoridation of water using dicarboxylic acids mediated chitosan-polyaniline/zirconium biopolymeric complex.

    PubMed

    Muthu Prabhu, Subbaiah; Meenakshi, Sankaran

    2016-04-01

    The present investigation describes the preparation of hydrogen bonded chitosan-polyaniline/zirconium biopolymeric matrix by grafting method under dicarboxylic acid medium for the removal of fluoride, first time. Herein, the dicarboxylic acids, oxalic acid, malonic acid, succinic acid were used as medium. The synthesized complex was characterized by usual analytical techniques like FTIR, XRD, SEM and EDAX analysis. From the batch equilibrium experiments, the maximum defluoridation capacity (DC) was found to be 8.713 mg/g at room temperature with the minimum contact time of 24 min at 100mg of the sorbent dosage. The temperature study results of adsorption kinetics showed the adsorption behavior could be better described by the pseudo-second-order equation than pseudo-first-order kinetic model. The adsorption isotherm was well fitted by the Freundlich equation rather than Langmuir and D-R isotherms. The mechanism of fluoride removal was ligand exchange at neutral pH and electrostatic attraction at acidic pH of the medium. Regeneration studies were carried out to identify the best regenerant which makes the process cost-effective. Conclusions of this work demonstrate the potential applicability of the dicarboxylic acid mediated chitosan-polyaniline/zirconium complex as an effective adsorbent for fluoride removal from water. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Interaction and complex formation between catalase and cationic polyelectrolytes: chitosan and Eudragit E100.

    PubMed

    Boeris, Valeria; Romanini, Diana; Farruggia, Beatriz; Picó, Guillemo

    2009-08-01

    Interactions between catalase and the cationic polyelectrolytes: chitosan and Eudragit E100 have been investigated owing to their scientific and technological importance. These interactions have been characterized by turbidimetry, circular dichroism and fluorescence spectroscopy. It was found that the catalase conformation does not change significantly during the chain entanglements between the protein and the polyelectrolytes. The effects of pH, ionic strength and anions which modify the water structure were evaluated on the polymer-protein complex formation. A net coulombic interaction force between them was found since the insoluble complex formation decreased after the NaCl addition. Both polymers were found to precipitate around 80% of the protein in solution. No modification of the tertiary and secondary protein structure or the enzymatic activity was observed when the precipitate was dissolved by changing the pH of the medium. Chitosan and Eudragit E100 proved to be a useful framework to isolate catalase or proteins with a slightly acid isoelectrical pH by means of precipitation.

  11. Preparation of microcapsules by complex coacervation of gum Arabic and chitosan.

    PubMed

    Butstraen, Chloé; Salaün, Fabien

    2014-01-01

    Gum Arabic-chitosan microcapsules containing a commercially available blend of triglycerides (Miglyol 812 N) as core phase were synthesized by complex coacervation. This study was conducted to clarify the influence of different parameters on the encapsulation process, i.e. during the emulsion formation steps and during the shell formation, using conductometry, zeta potential, surface and interface tension measurement and Fourier-transform infrared spectroscopy. By carefully analyzing the influencing factors including phase volume ratio, stirring rate and time, pH, reaction time, biopolymer ratio and crosslinking effect, the optimum synthetic conditions were found out. For the emulsion step, the optimum phase volume ratio chosen was 0.10 and an emulsion time of 15 min at 11,000 rpm was selected. The results also indicated that the optimum formation of these complexes appears at a pH value of 3.6 and a weight ratio of chitosan to gum Arabic mixtures of 0.25. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Applications of chitosan nanoparticles in drug delivery.

    PubMed

    Tajmir-Riahi, H A; Nafisi, Sh; Sanyakamdhorn, S; Agudelo, D; Chanphai, P

    2014-01-01

    We have reviewed the binding affinities of several antitumor drugs doxorubicin (Dox), N-(trifluoroacetyl) doxorubicin (FDox), tamoxifen (Tam), 4-hydroxytamoxifen (4-Hydroxytam), and endoxifen (Endox) with chitosan nanoparticles of different sizes (chitosan-15, chitosan-100, and chitosan-200 KD) in order to evaluate the efficacy of chitosan nanocarriers in drug delivery systems. Spectroscopic and molecular modeling studies showed the binding sites and the stability of drug-polymer complexes. Drug-chitosan complexation occurred via hydrophobic and hydrophilic contacts as well as H-bonding network. Chitosan-100 KD was the more effective drug carrier than the chitosan-15 and chitosan-200 KD.

  13. Low molecular weight chitosan-insulin polyelectrolyte complex: characterization and stability studies.

    PubMed

    Al-Kurdi, Zakieh I; Chowdhry, Babur Z; Leharne, Stephen A; Al Omari, Mahmoud M H; Badwan, Adnan A

    2015-03-30

    The aim of the work reported herein was to investigate the effect of various low molecular weight chitosans (LMWCs) on the stability of insulin using USP HPLC methods. Insulin was found to be stable in a polyelectrolyte complex (PEC) consisting of insulin and LMWC in the presence of a Tris-buffer at pH 6.5. In the presence of LMWC, the stability of insulin increased with decreasing molecular weight of LMWC; 13 kDa LMWC was the most efficient molecular weight for enhancing the physical and chemical stability of insulin. Solubilization of insulin-LMWC polyelectrolyte complex (I-LMWC PEC) in a reverse micelle (RM) system, administered to diabetic rats, results in an oral delivery system for insulin with acceptable bioactivity.

  14. Cellulose fibre networks reinforced with carboxymethyl cellulose/chitosan complex layer-by-layer.

    PubMed

    Wu, Tongfei; Farnood, Ramin

    2014-12-19

    An eco-friendly and full-polysaccharide polyelectrolyte complex system was developed to enhance the wet and dry tensile strength of cellulose fibre networks. Cellulose fibres were treated by carboxymethyl cellulose (CMC) in pulp suspension. Paper sheets made from CMC-treated fibres were further modified via the layer-by-layer (LbL) deposition of CMC/chitosan (CS) complex. The effect of number of CMC/CS layers on the strength properties of cellulose fibre networks (both under wet and dry conditions) was studied and sample structure was investigated by scanning electron microscopy (SEM). Water vapour transmission rate (WVTR) of CMC/CS-treated samples was also examined. The observed changes in the strength properties of treated samples were explained based on the competition between the rate of diffusion of CS to the fibre-fibre bond areas and the rate of disassociation of fibre-fibre interactions during the LbL deposition process.

  15. Formation of redispersible polyelectrolyte complex nanoparticles from gallic acid-chitosan conjugate and gum arabic.

    PubMed

    Hu, Qiaobin; Wang, Taoran; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

    2016-11-01

    Polyelectrolyte complex (PEC) nanoparticles between chitosan (CS) and biomacromolecules offer better physicochemical properties as delivery vehicles for nutrients than other CS-based nanoparticles. Our major objective was to fabricate PEC nanoparticles between water soluble gallic acid-chitosan conjugate (GA-CS) and gum arabic. The optimal fabrication method, physicochemical characteristics and stability were investigated. Furthermore, we also evaluated the effects of nano spray drying technology on the morphology and redispersibility of nanoparticle powders using Buchi B-90 Nano Spray Dryer. Results showed that the mass ratio between GA-CS and gum arabic and the preparation pH had significant contributions in determining the particle size and count rate of the nanoparticles, with the ratio of 3:1 and pH 5.0 being the optimal conditions that resulted in 112.2nm and 122.9kcps. The polyethylene glycol (PEG) played a vital role in forming the well-separated spray dried nanoparticles. The most homogeneous nanoparticles with the smoothest surface were obtained when the mass ratio of GA-CS and PEG was 1:0.5. In addition, the GA-CS/gum arabic spray dried nanoparticles exhibited excellent water-redispersibiliy compared to native CS/gum arabic nanoparticles. Our results demonstrated GA-CS/gum arabic nanoparticles were successfully fabricated with promising physicochemical properties and great potential for their applications in food and pharmaceutical industries.

  16. Enantioselective ecotoxicity of the herbicide dichlorprop and complexes formed with chitosan in two fresh water green algae.

    PubMed

    Wen, Yuezhong; Chen, Hui; Yuan, Yuli; Xu, Dongmei; Kang, Xiaodong

    2011-04-01

    To reduce the leaching potential, to prevent groundwater contamination and to maintain the efficacy of a pesticide, natural polysaccharides have received increasing attention due to their biocompatibility and useful biological reactivity for controlled release formulations (CRFs) of pesticides. In this paper, the toxicities of the chiral herbicide dichlorprop (DCPP) and its complexes with chitosan molecules (DCPP-CS) and chitosan nanoparticles (DCPP-NP) to two different green algae were determined and compared. The inhibition rates of DCPP, DCPP-CS and DCPP-NP were determined at 24, 48, 72, 96, 120, 144, 168 h, and the results show that (S)-DCPP was more toxic to Chlorella vulgaris than (R)-DCPP, while the (R)-DCPP was more toxic to Scenedesmus obliquus than (S)-DCPP. The study also found that the chiral selectivity of DCPP to Chlorella vulgaris and Scenedesmus obliquus could be changed when DCPP was complexed with chitosan molecules (CS) or chitosan nanoparticles (NP). For Chlorella vulgaris, the order of inhibition was (R)-DCPP-CS > (S)-DCPP-CS and (R)-DCPP-NP > (S)-DCPP-NP; for Scenedesmus obliquus, the order was (S)-DCPP-CS > (R)-DCPP-CS and (S)-DCPP-NP > (R)-DCPP-NP. This phenomenon suggests that the enantioselective behaviors of chiral compounds might shift when interactions with other chiral receptors coexist in different biological environments. Additionally, chitosan molecules and chitosan nanoparticles also showed different toxicities, which could be ascribed to the difference in the physicochemical properties between CS and NP or the differences in the cell walls of the two fresh water green algae.

  17. Chitosan/Chondroitin Sulfate Membranes Produced by Polyelectrolyte Complexation for Cartilage Engineering.

    PubMed

    Rodrigues, Mariana N; Oliveira, Mariana B; Costa, Rui R; Mano, João F

    2016-06-13

    Membranes made of chitosan (CHT) and chondroitin sulfate (CS) are herein presented using a polyelectrolyte complexation sedimentation/evaporation method. The membranes present high roughness and heterogeneous morphology induced by salt crystals. Exposing the membranes to different salt concentrations induces saloplastic behavior, as shown by an increasing water absorption and decreasing stiffness while exposed to increasing concentrations of salt. Establishing contact between two parts of a cut membrane leads to their self-adhesion and maintenance of their stretching ability. The membranes sustain the adhesion of ATDC5 prechondrocyte cells, inducing their rearrangement in cellular aggregates typical of chondrogenesis, and the expression of cartilage markers. Impregnated TGF-β3 remains loaded after 14 days of incubation, releasing only 1.2% of its total loaded mass. CHT/CS polyelectrolyte membranes are here shown as suitable candidates for the biomedical field, namely, for cartilage regeneration.

  18. Barium Titanate Nanoparticles: Highly Cytocompatible Dispersions in Glycol-chitosan and Doxorubicin Complexes for Cancer Therapy

    NASA Astrophysics Data System (ADS)

    Ciofani, Gianni; Danti, Serena; D'Alessandro, Delfo; Moscato, Stefania; Petrini, Mario; Menciassi, Arianna

    2010-07-01

    In the latest years, innovative nanomaterials have attracted a dramatic and exponentially increasing interest, in particular for their potential applications in the biomedical field. In this paper, we reported our findings on the cytocompatibility of barium titanate nanoparticles (BTNPs), an extremely interesting ceramic material. A rational and systematic study of BTNP cytocompatibility was performed, using a dispersion method based on a non-covalent binding to glycol-chitosan, which demonstrated the optimal cytocompatibility of this nanomaterial even at high concentration (100 μg/ml). Moreover, we showed that the efficiency of doxorubicin, a widely used chemotherapy drug, is highly enhanced following the complexation with BTNPs. Our results suggest that innovative ceramic nanomaterials such as BTNPs can be realistically exploited as alternative cellular nanovectors.

  19. Synthesis and characterization of chitosan-based polyelectrolyte complexes, doped by quantum dots

    NASA Astrophysics Data System (ADS)

    Abuzova, N. V.; Gerasimova, M. A.; Slabko, V. V.; Slyusareva, E. A.

    2015-12-01

    Doping of polymer particles by a fluorophores results in the sensitization within the visible spectral region becoming very promising materials for sensor applications. Colloids of biocompatible chitosan-based polyelectrolyte complexes (PECs) doped with quantum dots (QD) of CdTe and CdSe/ZnS (with sizes of 2.0-2.4 nm) were synthesized and characterized by scanning electron microscopy, dynamic light scattering, ζ-potential measurements, absorption and luminescence (including time-resolved) spectroscopy. The influence of ionic strength (0.02-1.5 M) on absorption and photoluminescence properties of encapsulated into PEC and unencapsulated quantum dots was investigated. The stability of the emission intensity of the encapsulated quantum dots has been shown to be strongly dependent on concentration of quantum dots.

  20. Physicochemical and antimicrobial properties of boron-complexed polyglycerol-chitosan dendrimers.

    PubMed

    Alencar de Queiroz, Alvaro Antonio; Abraham, Gustavo Abel; Pires Camillo, Maria Aparecida; Higa, Olga Zazuco; Silva, Gerald Saraiva; del Mar Fernández, María; San Román, Julio

    2006-01-01

    A polyglycerol with dendritic structure (PGLD) was synthesized by ring-opening polymerization of deprotonated glycidol using a polyglycerol as core functionality in a step-growth process. Then, PGLD reacted with O-carboxymethylated chitosan to obtain PGLD-chitosan dendrimer (PGLD-Ch). After the reaction of PGLD-Ch with boric acid, there was a marked increase in the bulk viscosity evidencing physically that boron can initiate a charge transfer complex formation, (PGLD-Ch)B. Gel permeation chromatography analysis was used to characterize the molecular weight and the polydispersivity of the synthesized PGLD-Ch. A dendritic structure with a molecular mass of 16.7 kDa and a narrow polydispersity (Mw/Mn = 1.05) was obtained. 1H-NMR and 13C-NMR measurements were employed to assess the degree of branching in PGLD. The obtained value of 0.85 indicates the tendency toward a dentritic structure for PGLD. The glass transition temperature values of (PGLD-Ch)B membranes containing 10% and 30% PGLD were -19 degrees C and -26 degrees C, respectively, which favor its potential use as surface coating of several polymers. The in vitro cytotoxicity was evaluated using the minimum essential medium elution test assay. Extracts of boron-complexed PGLD exhibited lower cytotoxicity than the controls, suggesting that the material has an improved biocompatibility. Antibacterial studies of (PGLD-Ch)B against Staphylococcus aureus and Pseudomonas aeruginosa showed a significant activity. Our study confirms and supports the effectiveness of (PGLD-Ch)B as an antimicrobial coating due to its capacity in suppressing the bacterial proliferation. The best in vivo response was found for (PGLD-Ch)B-30 membranes, which exhibited higher synthesis of collagen fibers than PGLD-ChB-10.

  1. Synthesis and characterization of water soluble O-carboxymethyl chitosan Schiff bases and Cu(II) complexes.

    PubMed

    Baran, Talat; Menteş, Ayfer; Arslan, Hülya

    2015-01-01

    In this study, mono-imine was synthesized (3a and 4a) via a condensation reaction between 2,4-pentadion and aminobenzoic acid (meta or para) in alcohol (1:1). The second-imine (CS-3a and CS-4a) was obtained as a result of the reaction of the free oxo groups of mono-imine (3a and 4a) with the amino groups on the chitosan (CS). Their structures were characterized with FTIR and (13)C CP-MAS. Then, the water soluble forms of CS-3a and CS-4a were obtained through oxidation of the hydroxide groups on the chitosan to carboxymethyl groups using monochloracetic acid ([O-CMCS-3a] · 2H2O and [O-CMCS-4a] · 2H2O). Thus, the solubility problem of chitosan in an aqueous media was overcome and Cu(II) complexes could be synthesized more easily. Characterization of the synthesized O-carboxymethyl chitosan Schiff base derivatives and their metal complexes, [O-CMCS-3a-Cu(OAc)2] · 2H2O and [O-CMCS-4a-Cu(OAc)2] · 2H2O, was conducted using FTIR, UV-Vis, TG/DTA, XRD, SEM, elemental analysis, conductivities and magnetic susceptibility measurements.

  2. Preparation of low molecular weight N-maleated chitosan-graft-PAMAM copolymer for enhanced DNA complexation.

    PubMed

    Sarkar, Kishor; Kundu, P P

    2012-12-01

    Low molecular weight N-maleated chitosan-graft-PAMAM (polyamidoamine) copolymer was prepared through N-maleated chitosan (NMC) by Michael type addition reaction to enhance its solubility in water as well as its cationic character for enhancement of DNA complexation. FTIR, (1)H NMR, XRD and GPC were used to characterize the graft copolymers. The copolymer showed better DNA complexation ability at low N/P ratio than that of chitosan due to increased surface charge density by the incorporation of PAMAM molecule on to chitosan backbone. The copolymer can effectively protect the DNA toward anionic surfactant. In vitro release study showed efficient DNA release occurred at physiological pH (pH 7.4). In vitro cell cytotoxicity test indicated toward less cytotoxicity of NMC-graft-PAMAM copolymers compared to that of 25 kDa PEI. Thus, the synthesized NMC-graft-PAMAM copolymers have great potential of finding application in drug and gene delivery. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Chitosan-bound pyridinedicarboxylate Ni(II) and Fe(III) complex biopolymer films as waste water decyanidation agents.

    PubMed

    Adewuyi, Sheriff; Jacob, Julianah Modupe; Olaleye, Oluwatoyin Omolola; Abdulraheem, Taofiq Olanrewaju; Tayo, Jubril Ayopo; Oladoyinbo, Fatai Oladipupo

    2016-10-20

    Chitosan is a biopolymer with immense structural advantage for chemical and mechanical modifications to generate novel properties, functions and applications. This work depicts new pyridinedicarboxylicacid (PDC) crosslinked chitosan-metal ion films as veritable material for cyanide ion removal from aqueous solution. The PDC-crosslinked chitosan-metal films (PDC-Chit-Ni(II) and PDC-Chit-Fe(III)) were formed by complexing PDC-crosslinked chitosan film with anhydrous nickel(II) and iron(III) chloride salts respectively. The PDC-Chit and its metal films were characterized employing various analytical and spectroscopic techniques. The FT-IR, UV-vis and the XRD results confirm the presence of the metal ions in the metal coordinated PDC-crosslinked chitosan film. The surface morphological difference of PDC-Chit-Ni(II) film before and after decyanidation was explored with scanning electron microscopy. Furthermore, the quantitative amount of nickel(II) and iron(III) present in the complex were determined using Atomic Absorption Spectrophotometer as 32.3 and 37.2μg/g respectively which portends the biopolymer film as a good complexing agent. Removal of cyanide from aqueous solution with PDC-Chit, PDC-Chit-Ni(II) and PDC-Chit-Fe(III) films was studied with batch equilibrium experiments. At equilibrium, decyanidation capacity (DC) followed the order PDC-Chit-Ni (II)≈PDC-Chit-Fe(III)>PDC-Chit. PDC-Chit-Ni(II) film gave 100% CN(-) removal within 40min decyanidation owing to favorable coordination geometry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Effect of Film-Forming Alginate/Chitosan Polyelectrolyte Complex on the Storage Quality of Pork.

    PubMed

    Kulig, Dominika; Zimoch-Korzycka, Anna; Król, Żaneta; Oziembłowski, Maciej; Jarmoluk, Andrzej

    2017-01-06

    Meat is one of the most challenging food products in the context of maintaining quality and safety. The aim of this work was to improve the quality of raw/cooked meat by coating it with sodium alginate (A), chitosan (C), and sodium alginate-chitosan polyelectrolyte complex (PEC) hydrosols. Antioxidant properties of A, C, and PEC hydrosols were determined. Subsequently, total antioxidant capacity (TAC), sensory quality of raw/cooked pork coated with experimental hydrosols, and antimicrobial efficiency of those hydrosols on the surface microbiota were analysed. Application analyses of hydrosol were performed during 0, 7, and 14 days of refrigerated storage in MAP (modified atmosphere packaging). Ferric reducing antioxidant power (FRAP) and (2,2-diphenyll-picrylhydrazyl (DPPH) analysis confirmed the antioxidant properties of A, C, and PEC. Sample C (1.0%) was characterized by the highest DPPH value (174.67 μM Trolox/mL) of all variants. PEC samples consisted of A 0.3%/C 1.0% and A 0.6%/C 1.0% were characterized by the greatest FRAP value (~7.21 μM Fe(2+)/mL) of all variants. TAC losses caused by thermal treatment of meat were reduced by 45% by coating meat with experimental hydrosols. Application of PEC on the meat surface resulted in reducing the total number of micro-organisms, psychrotrophs, and lactic acid bacteria by about 61%, and yeast and molds by about 45% compared to control after a two-week storage.

  5. Development and characterization of chitosan-polycarbophil interpolyelectrolyte complex-based 5-fluorouracil formulations for buccal, vaginal and rectal application

    PubMed Central

    2012-01-01

    Background of the study The present investigation was designed with the intention to formulate versatile 5-fluorouracil (5-FU) matrix tablet that fulfills the therapeutic needs that are lacking in current cancer treatment and aimed at minimizing toxic effect, enhancing efficacy and increasing patient compliance. The manuscript presents the critical issues of 5-FU associate with cancer and surpasses issues by engineering novel 5-FU matrix tablets utilizing chitosan- polycarbophil interpolyelectrolyte complex (IPEC). Methods Precipitation method is employed for preparation of chitosan and polycarbophil interpolyelectrolyte complex (IPEC) followed by characterization with Fourier transform infrared spectroscopy (FT-IR), Differential Scanning calorimeter (DSC) and X-ray Diffraction (XRD). 5-FU tablets were prepared by direct compression using IPEC. Six formulations were prepared with IPEC alone and in combination with chitosan, polycarbophil and Sodium deoxycholate. The formulations were tested for drug content, hardness, friability, weight variation, thickness, swelling studies, in vitro drug release (buccal, vaginal and rectal pH), ex vivo permeation studies, mucoadhesive strength and in vivo studies. Results FT-IR studies represent the change in spectra for the IPEC than single polymers.DSC study represents the different thermo gram for chitosan, polycarbophil and IPEC whereas in X-ray diffraction, crystal size alteration was observed. Formulations containing IPEC showed pH independent controlled 5-FU without an initial burst release effect in buccal, vaginal and rectal pH. Furthermore, F4 formulations showed controlled release 5-FU with highest bioadhesive property and satisfactory residence in both buccal and vaginal cavity of rabbit. 3% of SDC in formulation F6 exhibited maximum permeation of 5-FU. Conclusion The suitable combination of IPEC, chitosan and polycarbophil demonstrated potential candidate for controlled release of 5-FU in buccal, vaginal and rectal p

  6. Chelating efficiency and thermal, mechanical and decay resistance performances of chitosan copper complex in wood-polymer composites.

    PubMed

    Lu, John Z; Duan, Xinfang; Wu, Qinglin; Lian, Kun

    2008-09-01

    Wood-polymer composites (WPC) have been extensively used for building products, outdoor decking, automotive, packaging materials, and other applications. WPC is subject to fungal and termite attacks due to wood components enveloped in the thermoplastic matrix. Much effort has been made to improve decay resistance of WPC using zinc borate and other chemicals. In this study, chitosan copper complex (CCC) compounds were used as a potential preservative for wood-HDPE composites. CCC was formulated by reacting chitosan with copper salts under controlled conditions. Inductively coupled plasma (ICP) analytical results indicated that chitosan had high chelating efficiency with copper cations. CCC-treated wood-HDPE composites had a thermal behavior similar to untreated and zinc borate-treated wood-HDPE composites. Incorporation of CCC in wood-HDPE composites did not significantly influence board density of the resultant composites, but had a negative effect on tensile strength at high CCC concentration. In comparison with solid wood and the untreated wood-HDPE composites, 3% CCC-treated wood-HDPE composites significantly improved the decay resistance against white rot fungus Trametes versicolor and brown rot fungus Gloeophyllum trabeum. Especially, CCC-treated wood-HDPE composites were more effectively against the brown rot than the untreated and chitosan-treated wood-HDPE composites. Moreover, CCC-treated wood-HDPE composites performed well as zinc borate-treated wood-HDPE composites on fungal decay resistance. Accordingly, CCC can be effectively used as a preservative for WPC.

  7. The procoagulant properties of hyaluronic acid-collagen (I)/chitosan complex film.

    PubMed

    Hu, Yi; Wu, Yangzhe; Cai, Jiye; Ma, Shuyuan; Wang, Xiaoping

    2009-01-01

    Biomaterial-induced human platelet activation remains one of the most crucial factors to determine the procoagulant properties of the biomaterial. In this experiment, a new type of biomacromolecule complex film (hyaluronic acid-collagen (I)/chitosan, HCC) was prepared using the electrostatic self-assembly method. Then the procoagulant properties of this complex film were characterized. Based on the nano-resolution of atomic force microscopy, the platelet-derived microparticles (PMPs) that present the activation of platelets were clearly visualized on the membrane surface of platelets for the first time, and the measurement indicated that the size of PMPs is around 50-110 nm. Furthermore, the results of AFM measurement were confirmed by flow cytometry analysis. The expression of CD62P (P-selectin) dramatically increased after the platelet-rich plasma interacted with the biomaterial solution. From the results, we could draw the conclusion that this biomacromolecule complex film has promising procoagulant properties, and has the potential to be practically used as procoagulant material.

  8. Cost-effective alternative to nano-encapsulation: Amorphous curcumin-chitosan nanoparticle complex exhibiting high payload and supersaturation generation.

    PubMed

    Nguyen, Minh Hiep; Yu, Hong; Kiew, Tie Yi; Hadinoto, Kunn

    2015-10-01

    While the wide-ranging therapeutic activities of curcumin have been well established, its successful delivery to realize its true therapeutic potentials faces a major challenge due to its low oral bioavailability. Even though nano-encapsulation has been widely demonstrated to be effective in enhancing the bioavailability of curcumin, it is not without drawbacks (i.e. low payload and costly preparation). Herein we present a cost-effective bioavailability enhancement strategy of curcumin in the form of amorphous curcumin-chitosan nanoparticle complex (or curcumin nanoplex in short) exhibiting a high payload (>80%). The curcumin nanoplex was prepared by a simple yet highly efficient drug-polysaccharide complexation method that required only mixing of the curcumin and chitosan solutions under ambient condition. The effects of (1) pH and (2) charge ratio of chitosan to curcumin on the (i) physical characteristics of the nanoplex (i.e. size, colloidal stability and payload), (ii) complexation efficiency, and (iii) production yield were investigated from which the optimal preparation condition was determined. The nanoplex formation was found to favor low acidic pH and charge ratio below unity. At the optimal condition (i.e. pH 4.4. and charge ratio=0.8), stable curcumin nanoplex (≈260nm) was prepared at >90% complexation efficiency and ≈50% production yield. The amorphous state stability, colloidal stability, and in vitro non-cytotoxicity of the nanoplex were successfully established. The curcumin nanoplex produced prolonged supersaturation (3h) in the presence of hydroxypropyl methylcellulose (HPMC) at five times of the saturation solubility of curcumin. In addition, curcumin released from the nanoplex exhibited improved chemical stability owed to the presence of chitosan. Both results (i.e. high supersaturation and improved chemical stability) bode well for the ability of the curcumin nanoplex to enhance the bioavailability of curcumin clinically. Copyright © 2015

  9. In situ synthesis of polysaccharide nanoparticles via polyion complex of carboxymethyl cellulose and chitosan.

    PubMed

    Kaihara, Sachiko; Suzuki, Yoichi; Fujimoto, Keiji

    2011-07-01

    Biocompatible polymer-magnetite hybrid nanoparticles were prepared by means of in situ synthesis of magnetite within polysaccharide hydrogel nanoparticles. Hydrogel nanoparticles were first fabricated by blending high-molecular-weight carboxymethyl cellulose as an anionic polymer, and low-molecular-weight chitosan as a cationic polymer to form polyion complexes (CC particles). These polyion complexes were then chemically crosslinked using genipin, a bio-based cross-linker, to form stable nanoparticles having a semi-IPN structure (CCG particles). Magnetite was lastly synthesized within CCG particles by the coprecipitation method to obtain polymer-magnetite hybrid nanoparticles (CCGM particles). The formations of CC, CCG and CCGM particles were mainly observed by transmittance, absorbance of genipin and TEM, respectively, and their hydrodynamic diameters and zeta-potentials were analyzed. It was confirmed that the hydrodynamic diameters and the zeta-potentials of these particles were significantly influenced by pH of the suspension, which was attributed to the charges of polymers. The diameters of CCGM particles were smaller than 200 nm at any pH conditions, suggesting the possibility to apply them as drug delivery carriers. CCGM particles exhibited the responsiveness to a magnetic field in addition to their high dispersion stability, indicating their potential to be utilized as a biomaterial for hyperthermia. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Microfabricated photocrosslinkable polyelectrolyte-complex of chitosan and methacrylated gellan gum

    PubMed Central

    Coutinho, Daniela F.; Sant, Shilpa; Shakiba, Mojdeh; Wang, Ben; Gomes, Manuela E.; Neves, Nuno M.; Reis, Rui L.

    2012-01-01

    Chitosan (CHT) based polyelectrolyte complexes (PECs) have been receiving great attention for tissue engineering approaches. These hydrogels are held together by ionic forces and can be disrupted by changes in physiological conditions. In this study, we present a new class of CHT-based PEC hydrogels amenable to stabilization by chemical crosslinking. The photocrosslinkable anionic methacrylated gellan gum (MeGG) was complexed with cationic CHT and exposed to light, forming a PEC hydrogel. The chemical characterization of the photocrosslinkable PEC hydrogel by Fourier transform infrared spectroscopy (FTIR) revealed absorption peaks specific to the raw polymers. A significantly higher swelling ratio was observed for the PEC hydrogel with higher CHT content. The molecular interactions between both polysaccharides were evaluated chemically and microscopically, indicating the diffusion of CHT to the interior of the hydrogel. We hypothesized that the addition of MeGG to CHT solution first leads to a membrane formation around MeGG. Then, migration of CHT inside the MeGG hydrogel occurs to balance the electrostatic charges. The photocrosslinkable feature of MeGG further allowed the formation of cell-laden microscale hydrogel units with different shapes and sizes. Overall, this system is potentially useful for a variety of applications including the replication of microscale features of tissues for modular tissue engineering. PMID:23293429

  11. Synthesis of a novel chitosan-based Ce(IV) complex with proteolytic activity in vitro toward edible biological proteins.

    PubMed

    Li, Yan; Liu, Bingjie; Liu, Zihui; Meng, Xianghong; Wang, Dongfeng

    2016-04-20

    The occurrence of enzymatic activities is attributed to proper spatial organization of functional groups from first principles. A novel chitosan-based Ce(IV) complex (CC[Ce(IV)]), an artificial metalloproteinase, was synthesized by attaching cyclen, Ce(IV), and chlorophyll-Cu(II) to a chitosan-based matrix. The enzymatic hydrolytic efficiency (HE) and the procedure of catalyzing myoglobin (Mb) by CC[Ce(IV)] in vitro were investigated using spectrophotometry, electrophoresis, and liquid chromatography. The results showed that the HE of Mb was up to 60% at 60°C within 24h, displaying a catalytic proficiency. The pseudo-first-order kinetic constant (kobs) for CC[Ce(IV)] treatment within 24h was 3.85×10(-2)h(-1), higher than that for α-chymotrypsin treatment, which was 2.63×10(-2)h(-1). Moreover, the peptide bond derived from Asp-Phe/Phe-Asp in Mb could be specifically cleaved by CC[Ce(IV)], which could simulate the functionality of α-chymotrypsin. This work provides an experimental basis for potential utilization of the chitosan-based Ce(IV) complexes in the food industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Characterizations of chitosan-ammonium triflate (NH4CF3SO3) complexes by FTIR and impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Khiar, A. S. Ahmad; Puteh, R.; Arof, A. K.

    2006-02-01

    Polymer electrolytes using chitosan and ammonium triflate (NH4CF3SO3) were prepared using the solution cast technique. FTIR confirms the complexation of chitosan and NH4CF3SO3 with shifting of the amine peak at 1591 cm-1 to 1573 cm-1. The highest conducting sample contains 50 wt% of NH4CF3SO3 and at room temperature has a conductivity of 8.91 × 10-7 S cm-1. The model of Rice and Roth has been used to calculate the number density of mobile ions (n), mobility (μ) and diffusion constant (D). Conductivity was found to be dependent on the number of mobile ions. Analysis of electrical modulus and dissipation factor (tan δ) shows that charge transport occurs through a hopping mechanism.

  13. Preparation, characterization and cytotoxicity of carbon nanotube-chitosan-phycocyanin complex.

    PubMed

    Liao, Xiaoxia; Zhang, Xuewu

    2012-01-27

    Photodynamic therapy (PDT) or photothermal therapy (PTT) using nanomaterials has shown great prospect for cancer treatment. Phycocyanin (PC) is a photoharvesting pigment and is also an attractive candidate for PDT. The multiwalled carbon nanotube (MWNT) is a potent candidate for PTT due to its extraordinary photo-to-thermal energy conversion efficiency upon excitation with near-infrared (NIR) light. To date, although MWNT-CS complexes have been well studied, no report about the reconjugation of MWNT-CS with phycocyanin is available in the literature. Here, by using water-soluble chitosan (CS), we prepared and characterized a novel biomaterial, MWNT-CS-PC, with the potential for PDT and PTT. The cytotoxicity experiments found that MWNT-CS-PC exhibited cell growth inhibition activity. Moreover, with irradiation of NIR light (808 nm) or visible light (532 nm), the photoinduced cytotoxicity was indeed enhanced. These results suggest that MWNT-CS-PC may potentially serve as a future photodynamic and photothermal therapy for cancer.

  14. Preparation, characterization and cytotoxicity of carbon nanotube-chitosan-phycocyanin complex

    NASA Astrophysics Data System (ADS)

    Liao, Xiaoxia; Zhang, Xuewu

    2012-01-01

    Photodynamic therapy (PDT) or photothermal therapy (PTT) using nanomaterials has shown great prospect for cancer treatment. Phycocyanin (PC) is a photoharvesting pigment and is also an attractive candidate for PDT. The multiwalled carbon nanotube (MWNT) is a potent candidate for PTT due to its extraordinary photo-to-thermal energy conversion efficiency upon excitation with near-infrared (NIR) light. To date, although MWNT-CS complexes have been well studied, no report about the reconjugation of MWNT-CS with phycocyanin is available in the literature. Here, by using water-soluble chitosan (CS), we prepared and characterized a novel biomaterial, MWNT-CS-PC, with the potential for PDT and PTT. The cytotoxicity experiments found that MWNT-CS-PC exhibited cell growth inhibition activity. Moreover, with irradiation of NIR light (808 nm) or visible light (532 nm), the photoinduced cytotoxicity was indeed enhanced. These results suggest that MWNT-CS-PC may potentially serve as a future photodynamic and photothermal therapy for cancer.

  15. Chitosan Film Containing an Iron Complex: Synthesis and Prospects for Heterocyclic Aromatic Amines (HAAs) Recognition.

    PubMed

    da Silva, Maria Aparecida S; Abreu, Dieric S; Costa, Leandro A; Aguiar, Natanna de A; Paulo, Tércio F; Longhinotti, Elisane; Diógenes, Izaura C N

    2017-02-22

    Hybrid organic-inorganic materials have been seen as a promising approach to produce sensors for the detection and/or recognition of heterocyclic aromatic amines (HAAs). This work shows the synthesis of a hybrid film as a result of the incorporation of [Fe(CN)5(NH3)](3-) into chitosan (CS); CS-[(CN)5Fe(NH3)](3-). The sensitivity of CS-[(CN)5Fe(NH3)](3-) toward HAA-like species was evaluated by using pyrazine (pz) as probe molecule in vapor phase by means of electrochemistry and spectroscopic techniques. The crystallinity (SEM-EDS and XRD) decrease of CS-[(CN)5Fe(NH3)](3-) in comparison to CS was assigned to the disturbance of the hydrogen bond network within the polymer. Such conclusion was reinforced by the water contact angle measurements. The results presented in this work indicate physical and intermolecular interactions, mostly hydrogen bond, between [Fe(CN)5(NH3)](3-) and CS, where the complex is likely trapped in the polymer with its sixth coordination site available for substitution reactions.

  16. Nanocrystalline hydroxyapatite powders by a chitosan-polymer complex solution route: Synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Klinkaewnarong, Jutharatana; Swatsitang, Ekaphan; Maensiri, Santi

    2009-05-01

    Nanocrystalline hydroxyapatite (HAp) powders were successfully synthesized by a simple method using chitosan-polymer complex solution. To obtain HAp nanopowders, the prepared precursor was calcined in air at 400-800 °C for 2 h. The phase composition of the calcined samples was studied by X-ray diffraction (XRD) technique. The XRD results confirmed the formation of HAp phase with a small trace of monotite phase. With increasing calcination temperature, the crystallinity of the HAp increased, showing the hexagonal structure of HAp with the lattice parameter a in a range of 0.94030-0.94308 nm and c of 0.68817-0.68948 nm. The particle sizes of the powder were found to be 55.02-73.36 nm as evaluated by the XRD line broadening method. The chemical composition of the calcined powders was characterized by FTIR spectroscopy. The peaks of the phosphate carbonate and hydroxyl vibration modes were observed in the FTIR spectra for all the calcined powders. TEM investigation revealed that the prepared HAP samples consisted of rod-like nanoparticles having the particle size in the range of 100-300 nm. The corresponding selected-area electron diffraction (SAED) analysis further confirmed the formation of hexagonal structure of HAp.

  17. Chitosan-gum arabic polyelectrolyte complex films: physicochemical, mechanical and mucoadhesive properties.

    PubMed

    Sakloetsakun, Duangkamon; Preechagoon, Detpon; Bernkop-Schnürch, Andreas; Pongjanyakul, Thaned

    2016-08-01

    By blending chitosan (CS) and gum arabic (GA), a powerful biomaterial complex might be obtained due to the unique properties of CS and the low viscosity and good emulsifying properties of GA. The objectives of this study were to prepare and examine the properties of dispersions and films of CS and GA as a function of the mixing weight ratio, pH value and molecular weight of CS. The dispersions were characterized by turbidity, zeta potential and cytotoxicity and then the dispersions were cast into films. Physicochemical properties of the film were performed. CS-GA dispersions exhibited higher turbidity and a lower zeta potential with an increase in the GA ratio. Continuous films of the CS-GA could be formed at all ratios. CS and GA could molecularly interact via electrostatic forces and intermolecular hydrogen bonding. The CS-GA (1:0.5) films exhibited relatively low water uptake, erosion, water vapor permeability and puncture strength compared to the CS films. Furthermore, the CS-GA films demonstrated good mucoadhesive properties, allowing for adhesion to the mucosal membrane. Based on these results, it could be advantageous to use CS-GA films as film formers for the formulation of coatings and drug delivery systems.

  18. Chitosan-Carboxymethyl Tamarind Kernel Powder Interpolymer Complexation: Investigations for Colon Drug Delivery

    PubMed Central

    Kaur, Gurpreet; Jain, Subheet; Tiwary, Ashok K.

    2010-01-01

    The present study was aimed at evaluating the possible use of inter polymer complexed (IPC) films of chitosan (CH) and carboxymethyl tamarind kernel powder (CMTKP) for colon release of budesonide. Viscosity analysis of the supernatant liquid obtained after reacting CH and CMTKP in different proportions revealed 40:60 to be the optimum stoichiometric ratio. The FTIR spectra of IPC films formed from 50:50 or 40:60 ratio of CH:CMTKP did not reveal any reduction in the peaks at 1560cm−1 and 1407cm−1 after exposure to pH 1.2, suggesting resistance of the interaction between −COO− groups of CMTKP and −NH3+ groups of CH to gastric pH. Tablets containing Avicel pH 102 as diluent and coated to a weight gain of 10%, w/w with aqueous solutions of 40:60 or 50:50 ratio of CH:CMTKP did not release budesonide in pH 1.2 buffer. Histopathology of the rat colon after oral administration of these IPC film coated tablets revealed significantly greater (p<0.05) reduction in TNBS-induced ulcerative colitis as compared to that after administration of uncoated tablets. The Cmax of budesonide achieved after oral administration of these IPC film coated tablets was comparable to that observed after administration of uncoated tablets. The results strongly indicate versatility of CH-CMTKP IPC films to deliver budesonide in the colon. PMID:21179370

  19. Preparation, property of the complex of carboxymethyl chitosan grafted copolymer with iodine and application of it in cervical antibacterial biomembrane.

    PubMed

    Chen, Yu; Yang, Yumin; Liao, Qingping; Yang, Wei; Ma, Wanfeng; Zhao, Jian; Zheng, Xionggao; Yang, Yang; Chen, Rui

    2016-10-01

    Cervical erosion is one of the common diseases of women. The loop electrosurgical excisional procedure (LEEP) has been used widely in the treatment of the cervical diseases. However, there are no effective wound dressings for the postoperative care to protect the wound area from further infection, leading to increased secretion and longer healing time. Iodine is a widely used inorganic antibacterial agent with many advantages. However, the carrier for stable iodine complex antibacterial agents is lack. In the present study, a novel iodine carrier, Carboxymethyl chitosan-g-(poly(sodium acrylate)-co-polyvinylpyrrolidone) (CMCTS-g-(PAANa-co-PVP), was prepared by graft copolymerization of sodium acrylate (AANa) and N-vinylpyrrolidone (NVP) to a carboxymethyl chitosan (CMCTS) skeleton. The obtained structure could combine prominent property of poly(sodium acrylate) (PAANa) anionic polyelectrolyte segment and good complex property of polyvinylpyrrolidone (PVP) segment to iodine. The bioactivity of CMCTS could also be kept. The properties of the complex, CMCTS-g-(PAANa-co-PVP)-I2, were studied. The in vitro experiment shows that it has broad-spectrum bactericidal effects to virus, fungus, gram-positive bacteria and gram-negative bacteria. A CMCTS-g-(PAANa-co-PVP)-I2 complex contained cervical antibacterial biomembrane (CABM) was prepared. The iodine release from the CABM is pH-dependent. The clinic trial results indicate that CABM has better treatment effectiveness than the conventional treatment in the postoperative care of the LEEP operation. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Cu(II) and Pd(II) complexes of water soluble O-carboxymethyl chitosan Schiff bases: Synthesis, characterization.

    PubMed

    Baran, Talat; Menteş, Ayfer

    2015-08-01

    This study reports the synthesis of two new water soluble O-carboxymethyl chitosan Schiff bases (OCMCS-5 and OCMCS-6a) and their Cu(II) and Pd(II) complexes. Characterizations of these complexes were carried out with FTIR, elemental analysis, (13)C CPMAS, UV-vis, magnetic moment and molar conductivity techniques. The degrees of substitution (DS) for OCMCS-5a and OCMCS-6a were determined to be 0.48 and 0.44 in elemental analysis. The solubility test revealed that OCMCS-5a and OCMCS-6a dissolved thoroughly in water. The surface morphologies of chitosan (CS), OCMCS-5a, OCMCS-6a and their complexes were studied with SEM-EDAX. Thermal stability of the synthesized compounds was evaluated by TG/DTG and their crystallinity values were investigated with powder X-ray diffraction. Cu(II) and Pd(II) contents of the complexes were estimated with ICP-OES. The characterization studies demonstrated that the thermal stability and crystallinity values of the OCMCS-5a and OCMCS-6a were lower than those of CS.

  1. Enhanced gene delivery mediated by low molecular weight chitosan/DNA complexes: effect of pH and serum.

    PubMed

    Nimesh, Surendra; Thibault, Marc M; Lavertu, Marc; Buschmann, Michael D

    2010-10-01

    This study was designed to systematically evaluate the influence of pH and serum on the transfection process of chitosan-DNA complexes, with the objective of maximizing their efficiency. The hydrodynamic diameter of the complexes, measured by dynamic light scattering (DLS), was found to increase with salt and pH from 243 nm in water to 1244 nm in PBS at pH 7.4 and aggregation in presence of 10% serum. The cellular uptake of complexes into HEK 293 cells assessed by flow cytometry and confocal fluorescent imaging was found to increase at lower pH and serum. Based on these data, new methodology were tested and high levels of transfection (>40%) were achieved when transfection was initiated at pH 6.5 with 10% serum for 8-24 h to maximize uptake and then the media was changed to pH 7.4 with 10% serum for an additional 24-40 h period. Cytotoxicity of chitosan/DNA complexes was also considerably lower than Lipofectamine. Our study demonstrates that the evaluation of the influence of important parameters in the methodology of transfection enables the understanding of crucial physicochemical and biological mechanisms which allows for the design of methodologies maximising transgene expression.

  2. Enzyme-responsive polymeric supra-amphiphiles formed by the complexation of chitosan and ATP.

    PubMed

    Kang, Yuetong; Wang, Chao; Liu, Kai; Wang, Zhiqiang; Zhang, Xi

    2012-10-16

    Chitosan and adenosine-5'-triphosphate (ATP) are employed as building blocks to fabricate polymeric supra-amphiphiles based on electrostatic interactions, which can self-assemble to form spherical aggregates. The spherical aggregates inherit the phosphotase responsiveness of ATP. Compared to our previous work, this enzyme-responsive system can be more biocompatible and block polymers are not needed in preparation, which makes it possible to fabricate the chitosan-based enzyme-responsive assemblies in a large-scale, cheap way. Therefore, the application of the assemblies for nanocontainers and drug delivery is greatly anticipated.

  3. Chitosan-phosphotungstic acid complex as membranes for low temperature H2-O2 fuel cell

    NASA Astrophysics Data System (ADS)

    Santamaria, M.; Pecoraro, C. M.; Di Quarto, F.; Bocchetta, P.

    2015-02-01

    Free-standing Chitosan/phosphotungstic acid polyelectrolyte membranes were prepared by an easy and fast in-situ ionotropic gelation process performed at room temperature. Scanning electron microscopy was employed to study their morphological features and their thickness as a function of the chitosan concentration. The membrane was tested as proton conductor in low temperature H2-O2 fuel cell allowing to get peak power densities up to 350 mW cm-2. Electrochemical impedance measurements allowed to estimate a polyelectrolyte conductivity of 18 mS cm-1.

  4. Preparation of polyelectrolyte complex nanoparticles of chitosan and poly(2-acry1amido-2-methylpropanesulfonic acid) for doxorubicin release.

    PubMed

    Zhang, Liping; Wang, Jie; Ni, Caihua; Zhang, Yanan; Shi, Gang

    2016-01-01

    A new kind of polyelectrolyte complex (PEC) based on cationic chitosan (CS) and anionic poly(2-acry1amido-2-methylpropanesulfonic acid) (PAMPS) was prepared using a polymer-monomer pair reaction system. Chitosan was mixed with 2-acry1amido-2-methylpropanesulfonic acid) (AMPS) in an aqueous solution, followed by polymerization of AMPS. The complex was formed by electrostatic interaction of NH3(+) groups of CS and SO3(-) groups of AMPS, leading to a formation of complex nanoparticles of CS-PAMPS. A series of nanoparticles were obtained by changing the weight ratio of CS to AMPS, the structure and properties of nanoparticles were investigated. It was observed that the nanoparticles possessed spherical morphologies with average diameters from 255 nm to 390 nm varied with compositions of the nanoparticles. The nanoparticles were used as drug vehicles for doxorubicin, displaying relative high drug loading rate and encapsulation rate. The vitro release profiles revealed that the drug release could be controlled by adjusting pH of the release media. The nanoparticles demonstrated apparent advantages such as simple preparation process, free of organic solvents, size controllable, good biodegradability and biocompatibility, and they could be potentially used in drug controlled release field.

  5. Chitosan and alginate polyelectrolyte complex membranes and their properties for wound dressing application.

    PubMed

    Meng, Xin; Tian, Feng; Yang, Jian; He, Chun-Nian; Xing, Nan; Li, Fan

    2010-05-01

    This study investigated the characteristics and drug release properties of membranes of chitosan and alginate prepared via a casting/solvent evaporation technique. Membranes of chitosan and alginate with silver sulfadiazine as model drug incorporated in different concentrations and different membrane compositions were obtained. The polyblend solution viscosity reached to the highest at the composition polyblends of (1:1). This chitosan/alginate membranes showed pH- and ionic strength-dependent water uptake properties and had the WVTR rang from 442 to 618 g/m(2)/day. The maximum value of the dry membrane of breaking strength was 52.16 MPa and the maximum value of the wet membrane breaking elongation was 46.28%. The results of controlled release studies showed that the silver sulfadiazine release rate was the fastest when the alginate content was 50%. On the basis of the requisite physical properties, the chitosan-alginate PEC membrane can be considered for potential wound dressing or controlled release application.

  6. Towards a selective adsorbent for arsenate and selenite in the presence of phosphate: Assessment of adsorption efficiency, mechanism, and binary separation factors of the chitosan-copper complex.

    PubMed

    Yamani, Jamila S; Lounsbury, Amanda W; Zimmerman, Julie B

    2016-01-01

    The potential for a chitosan-copper polymer complex to select for the target contaminants in the presence of their respective competitive ions was evaluated by synthesizing chitosan-copper beads (CCB) for the treatment of (arsenate:phosphate), (selenite:phosphate), and (selenate:sulfate). Based on work by Rhazi et al., copper (II) binds to the amine moiety on the chitosan backbone as a monodentate complex (Type I) and as a bidentate complex crosslinking two polymer chains (Type II), depending on pH and copper loading. In general, the Type I complex exists alone; however, beyond threshold conditions of pH 5.5 during synthesis and a copper loading of 0.25 mol Cu(II)/mol chitosan monomer, the Type I and Type II complexes coexist. Subsequent chelation of this chitosan-copper ligand to oxyanions results in enhanced and selective adsorption of the target contaminants in complex matrices with high background ion concentrations. With differing affinities for arsenate, selenite, and phosphate, the Type I complex favors phosphate chelation while the Type II complex favors arsenate chelation due to electrostatic considerations and selenite chelation due to steric effects. No trend was exhibited for the selenate:sulfate system possibly due to the high Ksp of the corresponding copper salts. Binary separation factors, α12, were calculated for the arsenate-phosphate and selenite-phosphate systems, supporting the mechanistic hypothesis. While, further research is needed to develop a synthesis method for the independent formation of the Type II complexes to select for target contaminants in complex matrices, this work can provide initial steps in the development of a selective adsorbent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. A feeding study to assess nutritional quality and safety of surimi wash water proteins recovered by a chitosan-alginate complex.

    PubMed

    Wibowo, Singgih; Savant, Vivek; Cherian, Gita; Savage, Thomas F; Velazquez, Gonzalo; Torres, J Antonio

    2007-04-01

    Soluble proteins from surimi wash water (SWW) precipitated using a chitosan-alginate (Chi-Alg) complex and recovered by centrifugation were freeze-dried. Analysis showed that SWW proteins (SWWP) had a crude protein content of 73.1% and a high concentration of essential amino acids, for example, 3% histidine, 9.4% lysine, 3.7% methionine, and 5.1% phenylalanine. In a rat-feeding trial, SWWP as a single protein source showed higher (P < 0.05) modified protein efficiency ratio and net protein ratio than the casein control. Blood chemistry analysis revealed no deleterious effect from the full protein substitution or the chitosan in SWWP. Therefore, this preliminary study revealed that proteins recovered from SWW using the Chi-Alg complex could be used in feed formulations. They could be used for food production in countries where regulatory agencies allow the use of chitosan in the production of food ingredients.

  8. Polymeric material prepared from Schiff base based on O-carboxymethyl chitosan and its Cu(II) and Pd(II) complexes

    NASA Astrophysics Data System (ADS)

    Baran, Talat; Menteş, Ayfer

    2016-07-01

    In this study, a new eco-friendly Schiff base based on O-carboxymethyl chitosan ([OCMCS-7a]) and its copper(II) and palladium(II) complexes were synthesized. Characterizations of [OCMCS-7a] and its metal complexes were conducted using FTIR, 1H NMR, 13C NMR, TG/DTG, XRD, SEM-EDAX, ICP, UV-VIS, GC-MS, elemental analysis, magnetic moment and molar conductivity measurements. The degree of substitution (DS) of [OCMCS-7a] was determined by elemental analysis to be 0.44. It was shown by the solubility test that [OCMCS-7a] was completely soluble in water. Surface images of chitosan, [OCMCS-7a] and its Cu(II) and Pd(II) complexes were investigated using the SEM-EDAX technique. Their thermal behaviors and crystallinities of the synthesized complexes were determined by TG/DTG and X-ray powder diffraction techniques, respectively. The metal contents of the obtained complexes were determined using an ICP-OES instrument. From the analyses, it was noted that the thermal stabilities and crystallinities of [OCMCS-7a] and its complexes decreased compared to chitosan. As a consequence of surface screening, it was also noted that the surface structure of the chitosan was smoother than that of the obtained compounds.

  9. Direct Electrochemistry and Electrocatalysis of Horseradish Peroxidase Immobilized in a DNA/Chitosan-Fe₃O₄ Magnetic Nanoparticle Bio-Complex Film.

    PubMed

    Gu, Tingting; Wang, Jianli; Xia, Hongqi; Wang, Si; Yu, Xiaoting

    2014-02-11

    A DNA/chitosan-Fe₃O₄ magnetic nanoparticle bio-complex film was constructed for the immobilization of horseradish peroxidase (HRP) on a glassy carbon electrode. HRP was simply mixed with DNA, chitosan and Fe₃O₄ nanoparticles, and then applied to the electrode surface to form an enzyme-incorporated polyion complex film. Scanning electron microscopy (SEM) was used to study the surface features of DNA/chitosan/Fe₃O₄/HRP layer. The results of electrochemical impedance spectroscopy (EIS) show that Fe₃O₄ and enzyme were successfully immobilized on the electrode surface by the DNA/chitosan bio-polyion complex membrane. Direct electron transfer (DET) and bioelectrocatalysis of HRP in the DNA/chitosan/Fe₃O₄ film were investigated by cyclic voltammetry (CV) and constant potential amperometry. The HRP-immobilized electrode was found to undergo DET and exhibited a fast electron transfer rate constant of 3.7 s(-1). The CV results showed that the modified electrode gave rise to well-defined peaks in phosphate buffer, corresponding to the electrochemical redox reaction between HRP(Fe((III)())) and HRP(Fe((II))). The obtained electrode also displayed an electrocatalytic reduction behavior towards H₂O₂. The resulting DNA/chitosan/Fe₃O₄/HRP/glassy carbon electrode (GCE) shows a high sensitivity (20.8 A·cm(-2)·M(-1)) toward H₂O₂. A linear response to H₂O₂ measurement was obtained over the range from 2 µM to 100 µM (R² = 0.99) and an amperometric detection limit of 1 µM (S/N = 3). The apparent Michaelis-Menten constant of HRP immobilized on the electrode was 0.28 mM. Furthermore, the electrode exhibits both good operational stability and storage stability.

  10. A novel oral preparation of hydroxysafflor yellow A base on a chitosan complex: a strategy to enhance the oral bioavailability.

    PubMed

    Ma, Guan-nan; Yu, Fang-lin; Wang, Shan; Li, Zhi-ping; Xie, Xiang-yang; Mei, Xing-guo

    2015-06-01

    Hydroxysafflor yellow A (HSYA), the main active pharmaceutical ingredient of the safflower plant (Carthamus tinctorius L.), is a hydrophilic drug with low oral bioavailability (BA). The objective of the present study was to improve the oral BA of HSYA by formulation design. The effect of several pharmaceutical excipients on enhancing BA, including Poloxamer 188 (P188), sodium caprate (SC), sodium deoxycholate, and β-cyclodextrin (β-CD), was investigated through animal models. Sodium caprate, with a relative BA of 284.2%, was able to improve the oral BA of HSYA. Furthermore, HSYA can bind with chitosan (CS) by Coulomb attraction and form a HSYA-CS complex. The preparation process was optimized, and the binding rate reached 99.4%. HSYA granules were prepared using a HSYA-CS complex and SC. The results of the pharmacokinetics showed that the relative BA of HSYA granules was 476%, much higher than HSYA/SC.

  11. A new chitosan Schiff base supported Pd(II) complex for microwave-assisted synthesis of biaryls compounds

    NASA Astrophysics Data System (ADS)

    Baran, Talat

    2017-08-01

    In this study, a new heterogeneous palladium (II) catalyst that contains O-carboxymethyl chitosan Schiff base has been designed for Suzuki coupling reactions. The chemical structures of the synthesized catalyst were characterized with the FTIR, TG/DTG, ICP-OES, SEM/EDAX, 1H NMR, 13C NMR, GC/MS, XRD, and magnetic moment techniques. The reusability and catalytic behavior of heterogeneous catalyst was tested towards Suzuki reactions. As a result of the tests, excellent selectivity was obtained, and by-products of homo coupling were not seen in the spectra. The biaryls products were identified on a GC/MS. In addition, it was determined in the reusability tests that the catalysts could be used several times (seven runs). More importantly, with very low catalyst loading (6 × 10-3 mol %) in very short reaction time (5 min), chitosan Schiff base supported Pd(II) complex gave high TON and TOF values. These findings showed that Schiff base supported Pd(II) catalyst is suitable for Suzuki cross coupling reactions.

  12. Pharmacological performance of novel poly-(ionic liquid)-grafted chitosan-N-salicylidene Schiff bases and their complexes.

    PubMed

    Elshaarawy, Reda F M; Refaee, Ayaat A; El-Sawi, Emtithal A

    2016-08-01

    In our endeavor to develop a new class of pharmacological candidates with antimicrobial and anticancer efficacy, a series of biopolymeric chitosan Schiff bases bearing salicylidene ionic liquid (IL-Sal) brushes (ILCSB1-3, poly-(GlcNHAc-GlcNH2-(GlcN-Sal-IL)) was successfully synthesized by adopting efficient synthetic routes. Unfortunately, metalation trials of these biopolymeric Schiff bases afford the corresponding Ag(I)/M(II) complexes (where M=Co, Pd). These designed architectures were structurally characterized and pharmacologically evaluated for their in vitro antimicrobial, against common bacterial and fungal pathogens, and anticancer activities against human colon carcinoma (HCT-116) cell line. In conclusion functionalization of chitosan with IL-Sal brushes coupled with metalation of formed ILCSBs were synergistically enhanced its antimicrobial and antitumor properties to a great extent. Noteworthy, Ag-ILCSB2 (IC50=9.13μg/mL) was ca. 5-fold more cytotoxic against HCT-116 cell line than ILCSB2 (IC50=43.30μg/mL).

  13. In vivo gene transfer using pDNA/chitosan/chondroitin sulfate ternary complexes: influence of chondroitin sulfate on the stability of freeze-dried complexes and transgene expression in vivo.

    PubMed

    Hagiwara, Kenji; Kishimoto, Satoko; Ishihara, Masayuki; Koyama, Yoshiyuki; Mazda, Osam; Sato, Toshinori

    2013-02-01

    Chitosan has been investigated as a promising nonviral vector. However, several problems still remain, such as a relatively low transfection efficiency and instability under physiological conditions. We previously demonstrated that a chondroitin sulfate (CS) coating enhanced the transfection efficiency and physicochemical stability of plasmid DNA (pDNA)/chitosan complexes in vitro. In the present study, the effects of coating pDNA/chitosan complexes with CS on the stability in freeze-dry rehydration processes and gene expression in vivo were investigated. Freeze-drying storage at -20 °C, 4 °C, or room temperature, freezing storage at -20 °C, or liquid storage at 4 °C or room temperature, were examined for preservation conditions of pDNA/chitosan/CS ternary complexes by a gel retardation assay, measurements of sizes and zeta potentials, and a luciferase assay. Moreover, to determine the transfection efficiency of the ternary complexes in vivo, suicide gene therapy was carried out in Huh-7-implanted mice using herpes simplex virus thymidine kinase coding pDNA and ganciclovir. The freeze-dried pDNA/chitosan/CS ternary complexes showed sufficient cell transfection ability in vitro and in vivo. In addition, ternary complexes were associated with a significant suppression of tumor growth and a histopathologically high anti-tumor effect by intratumoral injection to tumor-bearing mice. The CS coating enhanced the preservation stability of the pDNA/chitosan complexes after freeze-drying-rehydration and their transgene expression in vivo. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Attenuation of transplant arteriosclerosis by oral feeding of major histocompatibility complex encoding chitosan-DNA nanoparticles.

    PubMed

    Goldmann, Katja; Hoffmann, Julia; Eckl, Sebastian; Spriewald, Bernd M; Ensminger, Stephan M

    2013-01-01

    One promising approach for the induction of transplant tolerance is the pre-treatment of transplant recipients with donor MHC-alloantigen. Our study focuses on the oral delivery of MHC-antigen encoding genes via chitosan-DNA nanoparticles to modulate the alloimmune response in order to reduce the development of transplant arteriosclerosis, the hallmark feature of chronic rejection after heart transplantation. Therefore, we performed fully allogeneic mouse abdominal aortic transplants using C57BL/6 (H2(b)) mice as donors and CBA.J (H2(k)) mice as recipients. Aortic grafts were analyzed by histology and morphometry on day 30 after transplantation, levels of circulating alloantibodies were detected by FACS analysis. Pre-treatment of recipient mice with chitosan-DNA nanoparticles encoding for K(b), one of the MHC-I molecules of the donor, resulted in a significant reduction of intimal proliferation compared to untreated controls. When Ovalbumin was fed instead of K(b) encoding nanoparticles (K(b)-NP) or Balb/c (H2(d)) grafts were used instead of C57BL/6 (H2(b)) grafts as antigen controls, both groups showed no reduction of intimal thickness indicating an antigen-specific mechanism. In addition, analysis of peripheral blood of the transplanted mice showed significant suppression of alloantibody formation in the K(b)-NP fed group compared to all other allogeneic transplanted groups suggesting modulation of the humoral immune response. These results demonstrate the potential of chitosan-DNA nanoparticles to induce K(b)-specific tolerance and to reduce the development of transplant arteriosclerosis.

  15. The preparation of polyelectrolyte complexes carboxymethyl chitosan(CMC)-pectin by reflux method as a Pb (II) metal ion adsorbent

    NASA Astrophysics Data System (ADS)

    Hastuti, Budi; Mudasir, Siswanta, Dwi; Triyono

    2016-02-01

    Aim of this research is to synthesized a chemically stable polyelectrolyte complexs carboxymetyl chitosan CMC-pectin as Pb(II) ion adsorbent by reflux method. During synthesis process, the optimum mass ratio of CMC and pectin was pre-determined and the active groups of the CMC-pectin complex was characterized by using IR spectrofotometer. Finally, adsorption capacity of the adsorbent material for Pb (II) ions was studied under optimum condition, i.e. adsorbent mass, contact time, and pH. Result shows that CMC could be succesfully combined with pectin to produce CMC-pectin complex. The optimum mass ratio CMC: pectin to form the polyelectrolyte complexs CMC-pectin was 70% : 30%. The active groups identified in the CMC-pectin complex was a hydroxyl (OH) and carboxylate (-COOH) groups. The optimum conditions for Pb (II) ion absoprtion was 10 mg of the adsorbent mass, 75 min of contact time, and pH 5. This material can be effectively used as adsorbents for Pb (II) ions, where up to 91% Pb (II) metal ions was adsorbed from aqueous solution and the adsorption capacity of the adsorbent was 41.63 mg/g.

  16. Interpolymer complexes of poly(acrylic acid) and chitosan: influence of the ionic hydrogel-forming medium.

    PubMed

    de la Torre, Paloma M; Torrado, Susana; Torrado, Santiago

    2003-04-01

    Non-covalent polyionic complexes were developed for localized antibiotic delivery in the stomach. Freeze-dried interpolymer complexes based on polyacrylic acid (PAA) and chitosan (CS) were prepared in a wide range of copolymer compositions by dissolving both polymers in acidic conditions. The influence of hydrogel-forming medium on the swelling and drug release was evaluated. The properties of these complexes were investigated by using scanning electron microscopy, dynamic swelling/eroding and release experiments in enzyme-free simulated gastric fluid (SGF). The electrostatic polymer/polymer interactions generate polyionic complexes with different porous structures. In a low pH environment, the separation of both polymer chains augmented as the amount of cationic and carboxilic groups increased within the network. However, the presence of higher amount of ions in the hydrogel-forming medium produced a network collapse, decreasing the maximum swelling ratio in SGF. PAA:CS:A (1:2.5:2)-1.75 M complexes released around 54% and 71% of the amoxicillin in 1 and 2 h, respectively, in acidic conditions. A faster drug release from this interpolymer complex was observed when the ionic strength of the hydrogel-forming medium increased. Complexes with a high amount of both polymer chains within the network, PAA:CS:A(2.5:5:2), showed a suitable amoxicillin release without being affected by an increased amount of ions in the hydrogel-forming medium. These freeze-dried interpolymer complexes could serve as potential candidates for amoxicillin delivery in an acidic enviroment. Copyright 2002 Elsevier Science Ltd.

  17. Pharmacokinetics of 2,4-di(alpha-methoxyethyl)deuteroporphyrin-IX (dimehin) and its complex with chitosan in mice with tumors

    NASA Astrophysics Data System (ADS)

    Ivanov, Andrei V.; Gradyushko, A. T.; Laptev, V. P.; Panferova, N. G.; Varlamov, V. P.; Klyashchitsky, B. A.; Reshetnickov, Andrei V.; Ponomarev, Gelii V.

    1996-01-01

    The kinetics of photosensitizer distribution and elimination have been studied using fluorescent methods in organs and tumors of A/Snell mice with embriocarcinoma inoculated into their thigh muscles for the porphyrin compound 2,4-di((alpha) -methoxyethyl)deuteroporphyrin-- IX (DMH, `Dimehin') and its complex with polysaccharide chitosan. DMH fluorescence differs in samples of liver and faeces which follows from the spectra comparison. DMH is metabolizable upon passing through liver into a form eliminated by the gastrointestinal tract as our pharmacokinetic data have shown. DMH has been found to be a short-term highly photodynamically efficient photosensitizer judging by combined analysis of our toxicological, pharmacokinetic and photodynamic research data. DMH-chitosan uptake and distribution studies have shown the complex's long-term persistence in blood circulation, high level accumulation in spleen and lungs, whereas there was no complex registered in tumors and other tissues following i.v. administration.

  18. Multipoint covalent immobilization of lipase on chitosan hybrid hydrogels: influence of the polyelectrolyte complex type and chemical modification on the catalytic properties of the biocatalysts.

    PubMed

    Mendes, Adriano A; de Castro, Heizir F; Rodrigues, Dasciana de S; Adriano, Wellington S; Tardioli, Paulo W; Mammarella, Enrique J; Giordano, Roberto de C; Giordano, Raquel de L C

    2011-08-01

    This work aimed at the production of stabilized derivatives of Thermomyces lanuginosus lipase (TLL) by multipoint covalent immobilization of the enzyme on chitosan-based matrices. The resulting biocatalysts were tested for synthesis of biodiesel by ethanolysis of palm oil. Different hydrogels were prepared: chitosan alone and in polyelectrolyte complexes (PEC) with κ-carrageenan, gelatin, alginate, and polyvinyl alcohol (PVA). The obtained supports were chemically modified with 2,4,6-trinitrobenzene sulfonic acid (TNBS) to increase support hydrophobicity, followed by activation with different agents such as glycidol (GLY), epichlorohydrin (EPI), and glutaraldehyde (GLU). The chitosan-alginate hydrogel, chemically modified with TNBS, provided derivatives with higher apparent hydrolytic activity (HA(app)) and thermal stability, being up to 45-fold more stable than soluble lipase. The maximum load of immobilized enzyme was 17.5 mg g(-1) of gel for GLU, 7.76 mg g(-1) of gel for GLY, and 7.65 mg g(-1) of gel for EPI derivatives, the latter presenting the maximum apparent hydrolytic activity (364.8 IU g(-1) of gel). The three derivatives catalyzed conversion of palm oil to biodiesel, but chitosan-alginate-TNBS activated via GLY and EPI led to higher recovered activities of the enzyme. Thus, this is a more attractive option for both hydrolysis and transesterification of vegetable oils using immobilized TLL, although industrial application of this biocatalyst still demands further improvements in its half-life to make the enzymatic process economically attractive.

  19. An in-vivo study for targeted delivery of copper-organic complex to breast cancer using chitosan polymer nanoparticles.

    PubMed

    Pramanik, Arindam; Laha, Dipranjan; Dash, Sandeep Kumar; Chattopadhyay, Sourav; Roy, Somenath; Das, Dipak Kumar; Pramanik, Panchanan; Karmakar, Parimal

    2016-11-01

    We have developed a strategy for targeted delivery of metal-diketo complex, "bis(2,4-pentanedionato) copper(II)" to breast cancer cells both in-vitro and in-vivo. This metal-organic complex induced ROS and subsequently DNA damage as well as mitochondrial membrane depolarization was observed. The mitochondria rupture further triggered apoptosis. For in-vitro targeting strategies, two different approaches were employed, folic acid or her-2 specific peptide (KCCYSL) was attached to stearic acid-modified polymeric Chitosan nanoparticles loaded with metal-organic complex "bis(2,4-pentanedionato)copper(II)". This was tested on two pairs of isogenic cells (FR+/FR- MCf-7 and her2+ /her2- MCF-7) and it was observed that cells expressing the receptor were susceptible to the drug whereas non-expressing isogenic cells were almost un-affected. During in-vivo studies, mice receiving targeted delivery of bis(2,4-pentanedionato) copper (II) had increased survivability and reduced tumor volume compared to non-targeted drug delivery. During toxicity studies for liver enzymes it was also found that the mice receiving targeted drug did not show any sign of liver damage as well as other histology changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Composite particles formed by complexation of poly(methacrylic acid) - stabilized magnetic fluid with chitosan: Magnetic material for bioapplications.

    PubMed

    Safarik, Ivo; Stepanek, Miroslav; Uchman, Mariusz; Slouf, Miroslav; Baldikova, Eva; Nydlova, Leona; Pospiskova, Kristyna; Safarikova, Mirka

    2016-10-01

    A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates.

  1. Preclinical evaluation of holmium-166 labeled anti-VEGF-A(Bevacizumab).

    PubMed

    Khorami-Moghadam, Alireza; Bolouri, Bahram; Jalilian, Amir Reza; Bahrami-Samani, Nariman Mosafa Ali; Mazidi, Seyed Mohammad; Alirezapour, Behrouz

    2013-06-30

    Radiolabeled antiangiogenic monoclonal antibodies are potential agents for targeted therapy in specific types of malignancies. In this study, (166)Ho-DOTA-Bevacizumab was used in biodistribution studies using single-photon emission computed tomography (SPECT) to acquire dosimetric aspects of the radiolabeled antibody in mice. The liver toxicity of the radiolabeled antibody was also determined using serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase and alkaline phosphatase assay 2-7 days post-injection. The SPECT biodistribution demonstrated a similar pattern as the other radiolabeled anti-vascular endothelial growth factor A (VEGF-A) immunoconjugates. (166)Ho-DOTA-Bevacizumab was revealed as a potential compound for therapy/imaging of VEGF-A expression in oncology.

  2. A new controlled-release liquid delivery system based on diclofenac potassium and low molecular weight chitosan complex solubilized in polysorbates.

    PubMed

    Athamneh, N A; Tashtoush, B M; Qandil, A M; Al-Tanni, B M; Obaidat, A A; Al-Jbour, N D; Qinna, N A; Al-Sou'od, K; Al-Remawi, M M; Badwan, A A

    2013-08-01

    A complex of low molecular weight chitosan (LMWC) with oleic acid and diclofenac potassium (DP) was prepared and dispersed in high concentrations of polysorbate 20, 60 and 80 in water to form a solution which releases its components slowly. The formed complex was characterized using different analytical methods. The size of the resulted nanoparticles and the effect of tweens on size were followed using dynamic light scattering (DLS). The release of DP from this delivery system was monitored by altering the molecular weight of chitosan and the type and concentration of the polysorbates used. The most suitable preparation consisted of DP, LMWC 13 kDa, and oleic acid. This was dispersed in 5% Tween 80 and the release was followed by the adaptation of USP II apparatus using a cellophane bag. This preparation offers a release of up to 24 h.

  3. Engineering interfacial properties by anionic surfactant-chitosan complexes to improve stability of oil-in-water emulsions.

    PubMed

    Zinoviadou, Kyriaki G; Scholten, Elke; Moschakis, Thomas; Biliaderis, Costas G

    2012-03-01

    Oil-in-water emulsions (10% w/w n-tetradecane) were prepared at pH = 5.7 by using, as surface active agents, electrostatically formed complexes of sodium stearoyl lactylate (SSL) at a concentration of 0.4% (w/w) and chitosan (CH) in a concentration range between 0 and 0.48% w/w. The use of complexes in emulsions with a low concentration of CH (<0.24% w/w) resulted in highly flocculated systems; instead, with increased level of CH, the emulsions had a smaller average droplet size and exhibited greater stability during storage. Emulsions stabilised by SSL/CH complexes showed non-Newtonian flow behavior with pronounced shear thinning. Among all formulations studied none showed a gel-like behavior since in all cases the G' (storage modulus) was lower that G'' (loss modulus). Adsorption kinetics of pure SSL and SSL/CH complexes to the oil/water interfaces were evaluated using an automated drop tensiometer (ADT). Even though complexation of SSL with CH resulted in a delay of the adsorption of the surface active species at the oil/water interface, the inclusion of the polysaccharide resulted in substantially improved interfacial properties as indicated by a significant increase of the dilatational modulus. Furthermore, the enhanced interfacial properties of the emulsion droplets resulted in improved stability against freeze-thaw cycling. The results of this study may facilitate the development of frozen food products such as desserts with an ameliorated stability and favorable sensorial characteristics.

  4. Elaboration of stable and antibody functionalized positively charged colloids by polyelectrolyte complexation between chitosan and hyaluronic acid.

    PubMed

    Polexe, Ramona C; Delair, Thierry

    2013-07-19

    In this study, we describe the elaboration of multifunctional positively charged polyelectrolyte complex (PEC) nanoparticles, designed to be stable at physiological salt concentration and pH, for effective targeted delivery. These nanoparticles were obtained by charge neutralization between chitosan (CS) as polycation and hyaluronic acid (HA) as polyanion. We showed that the course of the complexation process and the physico-chemical properties of the resulting colloids were impacted by (i) internal parameters such as the Degree of Acetylation (DA, i.e., the molar ration of acetyl glucosamine residues) and molar mass of CS, the HA molar mass and (ii) external parameters like the charge mixing ratio and the polymer concentrations. As a result, nonstoichiometric colloidal PECs were obtained in water or PBS (pH 7.4) and remained stable over one month. The polymer interactions were characterized by thermal analysis (DSC and TGA) and the morphology was studied by scanning electron microscopy. A model antibody, anti-ovalbumine (OVA) immunoglobulin A (IgA) was sorbed on the particle surface in water and PBS quantitatively in 4 h. The CS-HA/IgA nanoparticles average size was between 425-665 nm with a positive zeta potential. These results pointed out that CS-HA can be effective carriers for use in targeted drug delivery.

  5. Complex coacervation of collagen hydrolysate extracted from leather solid wastes and chitosan for controlled release of lavender oil.

    PubMed

    Ocak, Buğra

    2012-06-15

    In the world, approximately 600,000 metric tonnes of chromium-containing solid wastes are generated by the leather industry each year. Environmental concerns and escalating landfill costs are becoming increasingly serious problems to the leather industry and seeking solutions to these problems is a prime concern in much research today. In this study, solid collagen-based protein hydrolysate was isolated from chromium-tanned leather wastes and its chemical properties were determined. Microcapsules of collagen hydrolysate (CH) - chitosan (C) crosslinked with glutaraldehyde (GA) containing Lavender oil (LO) were prepared by complex coacervation method. The effects of various processing parameters, including the CH to C ratio, LO content, and GA, on the oil load (%), oil content (%), encapsulation efficiency (%) and release rate of LO from microcapsules were investigated. As the ratio of C present in the CH/C mixture and crosslinking density increased, the release rate of LO from microcapsules slowed down. Optical and scanning electron microscopy images illustrated that the LO microcapsules were spherical in shape. Fourier transform infrared spectroscopy (FTIR) studies confirmed that there was no significant interaction between CH/C complex and LO. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. The preparation, characterization, and pharmacokinetic studies of chitosan nanoparticles loaded with paclitaxel/dimethyl-β-cyclodextrin inclusion complexes.

    PubMed

    Ye, Ya-Jing; Wang, Yun; Lou, Kai-Yan; Chen, Yan-Zuo; Chen, Rongjun; Gao, Feng

    2015-01-01

    A novel biocompatible and biodegradable drug-delivery nanoparticle (NP) has been developed to minimize the severe side effects of the poorly water-soluble anticancer drug paclitaxel (PTX) for clinical use. PTX was loaded into the hydrophobic cavity of a hydrophilic cyclodextrin derivative, heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD), using an aqueous solution-stirring method followed by lyophilization. The resulting PTX/DM-β-CD inclusion complex dramatically enhanced the solubility of PTX in water and was directly incorporated into chitosan (CS) to form NPs (with a size of 323.9-407.8 nm in diameter) using an ionic gelation method. The formed NPs had a zeta potential of +15.9-23.3 mV and showed high colloidal stability. With the same weight ratio of PTX to CS of 0.7, the loading efficiency of the PTX/DM-β-CD inclusion complex-loaded CS NPs was 30.3-fold higher than that of the PTX-loaded CS NPs. Moreover, it is notable that PTX was released from the DM-β-CD/CS NPs in a sustained-release manner. The pharmacokinetic studies revealed that, compared with reference formulation (Taxol(®)), the PTX/DM-β-CD inclusion complex-loaded CS NPs exhibited a significant increase in AUC(0→24h) (the area under the plasma drug concentration-time curve over the period of 24 hours) and mean residence time by 2.7-fold and 1.4-fold, respectively. Therefore, the novel drug/DM-β-CD inclusion complex-loaded CS NPs have promising applications for the significantly improved delivery and controlled release of the poorly water-soluble drug PTX or its derivatives, thus possibly leading to enhanced therapeutic efficacy and less severe side effects.

  7. Complexes of silver(I) ions and silver phosphate nanoparticles with hyaluronic acid and/or chitosan as promising antimicrobial agents for vascular grafts.

    PubMed

    Chudobova, Dagmar; Nejdl, Lukas; Gumulec, Jaromir; Krystofova, Olga; Rodrigo, Miguel Angel Merlos; Kynicky, Jindrich; Ruttkay-Nedecky, Branislav; Kopel, Pavel; Babula, Petr; Adam, Vojtech; Kizek, Rene

    2013-06-28

    Polymers are currently widely used to replace a variety of natural materials with respect to their favourable physical and chemical properties, and due to their economic advantage. One of the most important branches of application of polymers is the production of different products for medical use. In this case, it is necessary to face a significant disadvantage of polymer products due to possible and very common colonization of the surface by various microorganisms that can pose a potential danger to the patient. One of the possible solutions is to prepare polymer with antibacterial/antimicrobial properties that is resistant to bacterial colonization. The aim of this study was to contribute to the development of antimicrobial polymeric material ideal for covering vascular implants with subsequent use in transplant surgery. Therefore, the complexes of polymeric substances (hyaluronic acid and chitosan) with silver nitrate or silver phosphate nanoparticles were created, and their effects on gram-positive bacterial culture of Staphylococcus aureus were monitored. Stages of formation of complexes of silver nitrate and silver phosphate nanoparticles with polymeric compounds were characterized using electrochemical and spectrophotometric methods. Furthermore, the antimicrobial activity of complexes was determined using the methods of determination of growth curves and zones of inhibition. The results of this study revealed that the complex of chitosan, with silver phosphate nanoparticles, was the most suitable in order to have an antibacterial effect on bacterial culture of Staphylococcus aureus. Formation of this complex was under way at low concentrations of chitosan. The results of electrochemical determination corresponded with the results of spectrophotometric methods and verified good interaction and formation of the complex. The complex has an outstanding antibacterial effect and this effect was of several orders higher compared to other investigated complexes.

  8. Complexes of Silver(I) Ions and Silver Phosphate Nanoparticles with Hyaluronic Acid and/or Chitosan as Promising Antimicrobial Agents for Vascular Grafts

    PubMed Central

    Chudobova, Dagmar; Nejdl, Lukas; Gumulec, Jaromir; Krystofova, Olga; Rodrigo, Miguel Angel Merlos; Kynicky, Jindrich; Ruttkay-Nedecky, Branislav; Kopel, Pavel; Babula, Petr; Adam, Vojtech; Kizek, Rene

    2013-01-01

    Polymers are currently widely used to replace a variety of natural materials with respect to their favourable physical and chemical properties, and due to their economic advantage. One of the most important branches of application of polymers is the production of different products for medical use. In this case, it is necessary to face a significant disadvantage of polymer products due to possible and very common colonization of the surface by various microorganisms that can pose a potential danger to the patient. One of the possible solutions is to prepare polymer with antibacterial/antimicrobial properties that is resistant to bacterial colonization. The aim of this study was to contribute to the development of antimicrobial polymeric material ideal for covering vascular implants with subsequent use in transplant surgery. Therefore, the complexes of polymeric substances (hyaluronic acid and chitosan) with silver nitrate or silver phosphate nanoparticles were created, and their effects on gram-positive bacterial culture of Staphylococcus aureus were monitored. Stages of formation of complexes of silver nitrate and silver phosphate nanoparticles with polymeric compounds were characterized using electrochemical and spectrophotometric methods. Furthermore, the antimicrobial activity of complexes was determined using the methods of determination of growth curves and zones of inhibition. The results of this study revealed that the complex of chitosan, with silver phosphate nanoparticles, was the most suitable in order to have an antibacterial effect on bacterial culture of Staphylococcus aureus. Formation of this complex was under way at low concentrations of chitosan. The results of electrochemical determination corresponded with the results of spectrophotometric methods and verified good interaction and formation of the complex. The complex has an outstanding antibacterial effect and this effect was of several orders higher compared to other investigated complexes

  9. Influence of electron beam irradiation on spectral, thermal, morphological and catalytic properties of Co(II) complex immobilized on chitosan's Schiff base.

    PubMed

    Antony, R; Theodore David, S; Karuppasamy, K; Sanjeev, Ganesh; Balakumar, S

    2014-04-24

    This study was carried out to investigate the effect of electron beam irradiation on the spectral and catalytic properties of chitosan supported (ONClCl) tetra coordinated Co(II) complex, [Co(OIAC)Cl2]. The complex was subjected to electron beam irradiation of 100 Gy, 1 kGy and 10 kGy doses. Chain scission of chitosan was observed on irradiation at 100 Gy and 10 kGy and chain linking at 1 kGy as evidenced by viscosity and FT-IR spectroscopic studies. This observation was also confirmed by thermo gravimetric and differential thermogravimetric (TG-DTG) analysis. It revealed that the thermal stability of the complex was increased at 1 kGy irradiation and decreased at 100 Gy and 10 kGy. In addition, the effect of electron beam irradiation on the surface morphology of the complex was studied by scanning electron microscopy. Catalytic abilities of both non-irradiated complex and irradiated complexes were determined and compared in the cyclohexane oxidation using hydrogen peroxide oxidant. The catalytic activity was found to increase after irradiation at all doses. Though the complex irradiated at 10 kGy showed highest conversion efficiency, irradiation at 1 kGy is suggested as the best dose due to the extensive reusability and adequate catalytic ability of the complex.

  10. Aptamer-Conjugated Chitosan-Anchored Liposomal Complexes for Targeted Delivery of Erlotinib to EGFR-Mutated Lung Cancer Cells.

    PubMed

    Li, Fengqiao; Mei, Hao; Xie, Xiaodong; Zhang, Huijuan; Liu, Jian; Lv, Tingting; Nie, Huifang; Gao, Yu; Jia, Lee

    2017-02-23

    Lung cancer is the leading cancer and has the highest death rate. The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) erlotinib has had a promising response in lung cancer therapy. Unfortunately, individuals with TKI-resistant EGFR mutations often develop acquired resistance against erlotinib. To overcome this resistance, in the present study, we developed liposomes anchored with anti-EGFR aptamer (Apt)-conjugated chitosan (Apt-Cs) as stable carriers to deliver erlotinib to the target. We loaded erlotinib into Apt-Cs-anchored liposomal complexes (Apt-CL-E) and characterized the physicochemistry of Apt-CL-E. The nanoparticles showed good biostability and a binding specificity for EGFR-mutated cancer cells guided by the Apt. The specific binding facilitated the uptake of Apt-CL-E into EGFR-mutated cancer cells. A cytotoxicity study showed an advantage of Apt-CL-E over their nontargeted liposomal counterparts in delivering erlotinib to EGFR-mutated cancer cells, resulting in cell cycle arrest and apoptosis. These results provide a good platform for future in vivo animal studies with Apt-CL-E.

  11. Oral delivery of an anti-diabetic peptide drug via conjugation and complexation with low molecular weight chitosan.

    PubMed

    Ahn, Sukyung; Lee, In-Hyun; Lee, Eunhye; Kim, Hyungjun; Kim, Yong-Chul; Jon, Sangyong

    2013-09-10

    Despite the therapeutic potential of exendin-4 as a glucagon-like peptide-1 (GLP-1) mimetic for the treatment of type 2 diabetes, its utility has so far been limited because of the low level of patient compliance due to the requirement for frequent injections. In this study, an orally available exendin-4 was produced by conjugating it to low molecular weight chitosan (LMWC). Conjugation between the LMWC and cysteinylated exendin-4 was carried out using a cleavable linker system in order to maximize the availability of the active peptide. The LMWC-exendin-4 conjugate formed a nanoparticle structure with a mean particle size of 101 ± 41 nm through complexation between the positively charged LMWC backbone and the negatively charged exendin-4 of individual conjugate molecules. The biological activity of the LMWC-exendin-4 conjugate was evaluated in an INS-1 cell line. The LMWC-exendin-4 conjugate stimulated insulin secretion in a dose dependent manner as similar as that of native exendin-4. From the pharmacokinetic study after oral administration of the conjugate, a C(max) value of 344 pg/mL and a T(max) of 6 h were observed, and the bioavailability, relative to the subcutaneous counterpart, was found to be 6.4%. Furthermore, the absorbed exendin-4 demonstrated a significantly enhanced hypoglycemic effect. These results suggest that the LMWC-exendin-4 conjugate could be used as a potential oral anti-diabetic agent for the treatment of type 2 diabetes.

  12. Preparation and characterization of polyelectrolyte complex nanoparticles based on poly (malic acid), chitosan. A pH-dependent delivery system.

    PubMed

    Arif, Muhammad; Raja, Mazhar Ali; Zeenat, Shah; Chi, Zhe; Liu, Chenguang

    2017-01-01

    The main objective of this work was to develop polyelectrolyte complex (PEC) nanoparticles based on poly (malic acid), chitosan (PMLA/CS) as pH-dependent delivery systems. The results indicated that the PMLA/CS Nps were successfully prepared. The prepared PMLA/CS Nps showed spherical morphology with a mean diameter of 212.81 nm and negative surface charge of -24.60 mV, and revealing significant pH-sensitive properties as the mass ratio of PMLA to CS was 5:5. The prepared PMLA/CS Nps were characterized by FT-IR, TEM and DLS. The prepared PMLA/CS Nps remained stable over a temperature range of 4-53 °C. Doxorubicin (Dox) as a model drug was loaded on the nanoparticles through the physical adsorption method. The high drug loading efficiency (16.9%) and the sustained release patterns in acidic media were observed, and the release accelerated in alkaline solutions. MTT based cytotoxic analysis also depicted the non-toxic nature of PMLA/CS Nps, while Dox-PMLA/CS Nps showed dose-dependent cytotoxicity towards MDA-MB-231 cells. Hence, the nanoparticles could be potentially applied as pH sensitive drug vehicles for controlled release.

  13. Permeability Profiles and Intestinal Toxicity Assessment of Hydrochlorothiazide and Its Inclusion Complex with β-Cyclodextrin Loaded into Chitosan Nanoparticles.

    PubMed

    Onnainty, R; Schenfeld, E M; Petiti, J P; Longhi, M R; Torres, A; Quevedo, M A; Granero, G E

    2016-11-07

    Here, a novel drug delivery system was developed for the hydrochlorothiazide (HCT):β-cyclodextrin (βCD) inclusion complex loaded into chitosan (CS) nanoparticles (NPs) [CS/HCT:βCD NPs]. It was found, for the first time, that exposure of the intestinal mucosa to free HCT resulted in an increased and abnormal intestinal permeability associated with several injuries to the intestinal epithelium. Nevertheless, the HCT delivery system obtained ameliorated the damage of the intestinal epithelium induced by HCT. Furthermore, we found that the corresponding permeability profiles for both the free HCT and the CS/HCT:βCD NPs were exponential and lineal, respectively. We propose that the increased intestinal uptake and severe tissue injury of HCT to the intestinal epithelium could be directly related to possible effects of this drug on the ionoregulatory Na(+/)K(+)-ATPase channel. Thus, it is postulated that the CS/HCT:βCD NPs may increase the gastrointestinal retention of the HCT, which would provide increased adherence to the mucus barrier that lines the intestinal epithelium; consequently, this would act as a slow HCT release delivery system and maintain lower drug levels of luminal gut in comparison with the administration of free HCT, leading to less severe local injury.

  14. Development of stable Pickering emulsions/oil powders and Pickering HIPEs stabilized by gliadin/chitosan complex particles.

    PubMed

    Yuan, D B; Hu, Y Q; Zeng, T; Yin, S W; Tang, C H; Yang, X Q

    2017-06-21

    In this paper, we demonstrate the use of gliadin/chitosan complex particles (GCCPs) as particulate stabilizers of oil-in-water emulsions of natural oils and water. For this purpose, we fabricated GCCPs through a facile anti-solvent procedure and demonstrated their usage in the formation of Pickering emulsions and Pickering high internal phase emulsions (HIPEs). The GCCPs can be used to produce surfactant-free o/w Pickering emulsions and Pickering HIPEs; unfortunately these emulsions were labile to coalescence. NaCl addition and/or pH regulation, and the combination were used to modify the surface wettability of the complex particles to achieve stable emulsions. The microstructures, e.g., interfacial frameworks, GCCP partition between the continuous phase and interfacial region, and the state of the droplets, of Pickering emulsions were visualized by confocal laser scanning microscopy (CLSM), confirming that the inclusion of NaCl and slightly adjusting pH toward 4.0 and/or 5.0 benefited the adsorption and accumulation of colloid particles at the droplet surface to form an engineered interfacial structure, bridging droplets together through a percolating layer of colloidal particles at the oil/water interface. A schematic representation for the formation route of the emulsions is proposed to relate the physical performance and rheological property with the interfacial structures and aggregate behaviors in the Pickering system stabilized by the complex particles. Interestingly, direct freeze-drying of the emulsions transformed unstable Pickering emulsions into stable oil powders. This study opens a promising route based on Pickering HIPEs or oil powders to structure liquid oils into solid-like fats without artificial trans-fat, which outlines new directions for future fundamental research.

  15. Synthesis, characterization and biological activity of Cu(II), Ni(II) and Zn(II) complexes of biopolymeric Schiff bases of salicylaldehydes and chitosan.

    PubMed

    de Araújo, Eliene Leandro; Barbosa, Hellen Franciane Gonçalves; Dockal, Edward Ralph; Cavalheiro, Éder Tadeu Gomes

    2017-02-01

    Schiff bases have been prepared from biopolymer chitosan and salicylaldehyde, 5-methoxysalicylaldehyde, and 5-nitrosalicylaldehyde. Ligands were synthesized in a 1:1.5mol ratio, and their Cu(II), Ni(II) and Zn(II) complexes in a 1:1mol ratio (ligand:metal). Ligands were characterized by (1)H NMR and FTIR, resulting in degrees of substitution from 43.7 to 78.7%. Complexes were characterized using FTIR, electronic spectra, XPRD. The compounds were confirmed by the presence of an imine bond stretching in the 1630-1640cm(-1) and νMetal-N and νMetal-O at <600cm(-1). Electronic spectra revealed that both Cu(II) and Ni(II) complexes present a square plane geometry. The crystallinity values were investigated by X-ray powder diffraction. Thermal behavior of all compounds was evaluated by TGA/DTG and DTA curves with mass losses related to dehydration and decomposition, with characteristic events for ligand and complexes. Schiff base complexes presented lower thermal stability and crystallinity than the starting chitosan. Residues were the metallic oxides as confirmed by XPRD, whose amounts were used in the calculation of the percentage of complexed metal ions. Surface morphologies were analyzed with SEM-EDAX. Preliminary cytotoxicity tests were performed using MTT assay with HeLa cells. Despite the differences in solubility, the free bases presented relatively low toxicity.

  16. Effective photosensitization-based inactivation of Gram (-) food pathogens and molds using the chlorophyllin-chitosan complex: towards photoactive edible coatings to preserve strawberries.

    PubMed

    Buchovec, Irina; Lukseviciute, Viktorija; Marsalka, Arunas; Reklaitis, Ignas; Luksiene, Zivile

    2016-04-01

    This study is focused on the novel approaches to enhance the inactivation of the Gram (-) food pathogen Salmonella enterica and harmful molds in vitro and on the surface of strawberries using the chlorophyllin-chitosan complex. Salmonella enterica (∼1 × 10(7) CFU mL(-1)) was incubated with chlorophyllin 1.5 × 10(-5) M (Chl, food additive), chitosan 0.1% (CHS, food supplement) or the chlorophyllin-chitosan complex (1.5 × 10(-5) M Chl-0.1% CHS) and illuminated with visible light (λ = 405 nm, light dose 38 J cm(-2)) in vitro. Chlorophyllin (Chl)-based photosensitization inactivated Salmonella just by 1.8 log. Chitosan (CHS) alone incubated for 2 h with Salmonella reduced viability 2.15 log, whereas photoactivated Chl-CHS diminished bacterial viability by 7 log. SEM images indicate that the Chl-CHS complex under these experimental conditions covered the entire bacterial surface. Significant cell membrane disintegration was the main lethal injury induced in Gram (-) bacteria by this treatment. Analysis of strawberry decontamination from surface-inoculated Salmonella indicated that photoactivated Chl-CHS (1.5 × 10(-5) M Chl-0.1% CHS, 30 min incubation, light dose 38 J cm(-2)) coatings diminished the pathogen population on the surface of strawberries by 2.2 log. Decontamination of strawberries from naturally distributed yeasts/molds revealed that chitosan alone reduced the population of yeasts/molds just by 0.4 log, Chl-based photosensitization just by 0.9 log, whereas photoactivated Chl-CHS coatings reduced yeasts/molds on the surface of strawberries by 1.4 log. Electron paramagnetic resonance spectroscopy confirmed that no additional photosensitization-induced free radicals have been found in the strawberry matrix. Visual quality (color, texture) of the treated strawberries was not affected either. In conclusion, photoactive Chl-CHS exhibited strong antimicrobial action against more resistant to photosensitization Gram (-) Salmonella enterica in comparison with

  17. Construction of antibacterial multilayer films containing nanosilver via layer-by-layer assembly of heparin and chitosan-silver ions complex.

    PubMed

    Fu, Jinhong; Ji, Jian; Fan, Dezeng; Shen, Jiacong

    2006-12-01

    Antibacterial multilayer films containing nanosilver were prepared via layer-by-layer fashion. PET film was aminolyzed with 1,6-hexanediamine to introduce amino groups on PET film surface; chitosan-silver nitrate complex and heparin were alternately deposited onto an aminolyzed PET film surface, and subsequently, the silver ions within the multilayer films were reduced with ascorbic acid to form silver nanoparticles. UV-visible spectroscopy and transmission electron microscopy confirmed the formation of well-dispersed nanosilver particles with sizes (10-40 nm) that depended on the initial concentration of silver ions in chitosan solution and the pH of ascorbic acid solution. The chitosan/heparin multilayer films were possessed of bactericidal effect on Escherichia coli (E. coli), and this antibacterial effect could be significantly enhanced by the incorporation of silver nanoparticles into the multilayer films. The multilayer films containing nanosilver were not only effective as antibacterial but also as anticoagulant coating. And cell toxicity evaluation suggested that the multilayer films containing nanosilver did not show any cytotoxicity. The multilayer films containing nanosilver may have good potentials for surface modification of medical devices, especially for cardiovascular implants.

  18. Glucose adsorption to chitosan membranes increases proliferation of human chondrocyte via mammalian target of rapamycin complex 1 and sterol regulatory element-binding protein-1 signaling.

    PubMed

    Chang, Shun-Fu; Huang, Kuo-Chin; Cheng, Chin-Chang; Su, Yu-Ping; Lee, Ko-Chao; Chen, Cheng-Nan; Chang, Hsin-I

    2017-10-01

    Osteoarthritis (OA) is currently still an irreversible degenerative disease of the articular cartilage. Recent, dextrose (d-glucose) intraarticular injection prolotherapy for OA patients has been reported to benefit the chondrogenic stimulation of damaged cartilage. However, the detailed mechanism of glucose's effect on cartilage repair remains unclear. Chitosan, a naturally derived polysaccharide, has recently been investigated as a surgical or dental dressing to control breeding. Therefore, in this study, glucose was adsorbed to chitosan membranes (CTS-Glc), and the study aimed to investigate whether CTS-Glc complex membranes could regulate the proliferation of human OA chondrocytes and to explore the underlying mechanism. Human OA and SW1353 chondrocytes were used in this study. The experiments involving the transfection of cells used SW1353 chondrocytes. A specific inhibitor and siRNAs were used to investigate the mechanism underlying the CTS-Glc-regulated proliferation of human chondrocytes. We found that CTS-Glc significantly increased the proliferation of both human OA and SW1353 chondrocytes comparable to glucose- or chitosan-only stimulation. The role of mammalian target of rapamycin complex 1 (mTORC1) signaling, including mTOR, raptor, and S6k proteins, has been demonstrated in the regulation of CTS-Glc-increased human chondrocyte proliferation. mTORC1 signaling increased the expression levels of maturated SREBP-1 and FASN and then induced the expressions of cell cycle regulators, that is, cyclin D, cyclin-dependent kinase-4 and -6 in human chondrocytes. This study elucidates the detailed mechanism behind the effect of CTS-Glc complex membranes in promoting chondrocyte proliferation and proposes a possible clinical application of the CTS-Glc complex in the dextrose intraarticular injection of OA prolotherapy in the future to attenuate the pain and discomfort of OA patients. © 2017 Wiley Periodicals, Inc.

  19. SUPRAMOLECULAR COMPOSITE MATERIALS FROM CELLULOSE, CHITOSAN AND CYCLODEXTRIN: FACILE PREPARATION AND THEIR SELECTIVE INCLUSION COMPLEX FORMATION WITH ENDOCRINE DISRUPTORS

    PubMed Central

    Duri, Simon; Tran, Chieu D.

    2013-01-01

    We have successfully developed a simple and one step method to prepare high performance supramolecular polysaccharide composites from cellulose (CEL), chitosan (CS) and (2,3,6-tri-O-acetyl)-α-, β- and γ-cyclodextrin (α-, β- and γ-TCD). In this method, [BMIm+Cl−], an ionic liquid (IL), was used as a solvent to dissolve and prepare the composites. Since majority (>88%) of the IL used was recovered for reuse, the method is recyclable. XRD, FT-IR, NIR and SEM were used to monitor the dissolution process and to confirm that the polysaccharides were regenerated without any chemical modifications. It was found that unique properties of each component including superior mechanical properties (from CEL), excellent adsorbent for pollutants and toxins (from CS) and size/structure selectivity through inclusion complex formation (from TCDs) remain intact in the composites. Specifically, results from kinetics and adsorption isotherms show that while CS-based composites can effectively adsorb the endocrine disruptors (polychlrophenols, bisphenol-A), its adsorption is independent on the size and structure of the analytes. Conversely, the adsorption by γ-TCD-based composites exhibits strong dependency on size and structure of the analytes. For example, while all three TCD-based composites (i.e., α-, β- and γ-TCD) can effectively adsorb 2-, 3- and 4-chlorophenol, only γ-TCD-based composite can adsorb analytes with bulky groups including 3,4-dichloro- and 2,4,5-trichlorophenol. Furthermore, equilibrium sorption capacities for the analytes with bulky groups by γ-TCD-based composite are much higher than those by CS-based composites. Together, these results indicate that γ-TCD-based composite with its relatively larger cavity size can readily form inclusion complexes with analytes with bulky groups, and through inclusion complex formation, it can strongly adsorb much more analytes and with size/structure selectivity compared to CS-based composites which can adsorb the

  20. Supramolecular composite materials from cellulose, chitosan, and cyclodextrin: facile preparation and their selective inclusion complex formation with endocrine disruptors.

    PubMed

    Duri, Simon; Tran, Chieu D

    2013-04-23

    We have successfully developed a simple one-step method of preparing high-performance supramolecular polysaccharide composites from cellulose (CEL), chitosan (CS), and (2,3,6-tri-O-acetyl)-α-, β-, and γ-cyclodextrin (α-, β-, and γ-TCD). In this method, [BMIm(+)Cl(-)], an ionic liquid (IL), was used as a solvent to dissolve and prepare the composites. Because a majority (>88%) of the IL used was recovered for reuse, the method is recyclable. XRD, FT-IR, NIR, and SEM were used to monitor the dissolution process and to confirm that the polysaccharides were regenerated without any chemical modifications. It was found that unique properties of each component including superior mechanical properties (from CEL), excellent adsorption for pollutants and toxins (from CS), and size/structure selectivity through inclusion complex formation (from TCDs) remain intact in the composites. Specifically, the results from kinetics and adsorption isotherms show that whereas CS-based composites can effectively adsorb the endocrine disruptors (polychlrophenols, bisphenol A), their adsorption is independent of the size and structure of the analytes. Conversely, the adsorption by γ-TCD-based composites exhibits a strong dependence on the size and structure of the analytes. For example, whereas all three TCD-based composites (i.e., α-, β-, and γ-TCD) can effectively adsorb 2-, 3-, and 4-chlorophenol, only the γ-TCD-based composite can adsorb analytes with bulky groups including 3,4-dichloro- and 2,4,5-trichlorophenol. Furthermore, the equilibrium sorption capacities for the analytes with bulky groups by the γ-TCD-based composite are much higher than those by CS-based composites. Together, these results indicate that the γ-TCD-based composite with its relatively larger cavity size can readily form inclusion complexes with analytes with bulky groups, and through inclusion complex formation, it can strongly adsorb many more analytes and has a size/structure selectivity compared to

  1. Resonance Rayleigh Scattering Spectra of an Ion-Association Complex of Naphthol Green B-Chitosan System and Its Application in the Highly Sensitive Determination of Chitosan.

    PubMed

    Zhang, Weiai; Ma, Caijuan; Su, Zhengquan; Bai, Yan

    2016-04-18

    This work describes a highly-sensitive and accurate approach for the determination of chitosan (CTS) using Naphthol Green B (NGB) as a probe in the Resonance Rayleigh scattering (RRS) method. The interaction between CTS and NGB leads to notable enhancement of RRS, and the enhancement is proportional to the concentration of CTS over a certain range. Under optimum conditions, the calibration curve of ΔI against CTS concentration was ΔI = 1860.5c + 86.125 (c, µg/mL), R² = 0.9999, and the linear range and detection limit (DL) were 0.01-5.5 µg/mL and 8.87 ng/mL. Moreover, the effect of the molecular weight of CTS on the accurate quantification of CTS was studied. The experimental data were analyzed through linear regression analysis using SPSS20.0, and the molecular weight was found to have no statistical significance. This method has been applied to assay two CTS samples and obtained good recovery and reproducibility.

  2. [Evaluation of the binding affinity and RNA interference of low-molecular-weight chitosan/siRNA complexes using an imaging system].

    PubMed

    Kawaguchi, Yasuhisa; Okuda, Tomoyuki; Ban, Tatsunori; Danjo, Kazumi; Okamoto, Hirokazu

    2009-04-01

    Chitosan is one of the attractive non-viral carriers for gene delivery including siRNA. However, common chitosan, which has a relatively high molecular weight, is insoluble in water, which might make it difficult to apply clinically. In this study, we investigated the efficacy of low-molecular-weight chitosan (LMWC), which is soluble in water, as a carrier for siRNA delivery. To evaluate the binding affinity and RNA interference (RNAi) of LMWC/siRNA complexes, a multi-well imaging system (IVIS) was adapted. CT26 cells stably expressing firefly luciferase (CT26/Luc cells) were established to evaluate RNAi. Evaluation of RNAi using lipofectamine(TM) 2000 was carried out by employing a luminometer with cell lysis and IVIS without cell lysis. The results were closely correlated, suggesting the advantages of the multi-well imaging system regarding screening, the visualization of results, and nondestructive evaluation. Fluorescence generated by ethidium bromide intercalated in the double strand of siRNA was markedly quenched at a higher ratio of LMWC to siRNA (N/P) and lower pH. Evaluation of the particle size and zeta potential of LMWC/siRNA complexes also indicated the higher binding affinity of LMWC with siRNA. At N/P=300 and pH 6.5, which satisfied the high-level binding affinity of LMWC with siRNA, significantly lower luminescence was detected in CT26/Luc cells treated with LMWC/siRNA compared with those treated with LMWC alone, suggesting the presence of RNAi. These results suggested that LMWC may be an effective carrier for siRNA delivery, and that the multi-well imaging system may be a powerful tool to evaluate the binding affinity and RNAi.

  3. Chitosan supported Zn(II) mixed ligand complexes as heterogeneous catalysts for one-pot synthesis of amides from ketones via Beckmann rearrangement

    NASA Astrophysics Data System (ADS)

    Anuradha; Kumari, Shweta; Layek, Samaresh; Pathak, Devendra D.

    2017-02-01

    Chitosan supported Zn(II) mixed ligand complexes have been synthesized and characterized by FT-IR, UV-Vis, TGA, XRD, FESEM, EDX, AAS and Elemental Analysis. These complexes have been found to be efficient and recyclable heterogeneous catalysts for the one-pot synthesis of amides via Beckmann rearrangement. All three complexes can be easily filtered out from the reaction medium and reused up to five times without significant loss of catalytic activity. The reported protocol is economical and novel in the sense that amides can be easily synthesized in only one-step. All products were obtained as white to off-white crystalline solids and fully characterized by 1H NMR, FT-IR and Mass Spectra.

  4. Fabrication and characterization of antioxidant pickering emulsions stabilized by zein/chitosan complex particles (ZCPs).

    PubMed

    Wang, Li-Juan; Hu, Ya-Qiong; Yin, Shou-Wei; Yang, Xiao-Quan; Lai, Fu-Rao; Wang, Si-Qi

    2015-03-11

    Lipid peroxidation in oil-in-water (o/w) emulsions leads to rancidity and carcinogen formation. This work attempted to protect lipid droplets of emulsions from peroxidation via manipulation of the emulsions' interface framework using dual-function zein/CH complex particles (ZCPs). ZCP with intermediate wettability was fabricated via a simple antisolvent approach. Pickering emulsions were produced via a simple and inexpensive shear-induced emulsification technique. ZCP was irreversibly anchored at the oil-water interface to form particle-based network architecture therein, producing ultrastable o/w Pickering emulsions (ZCPEs). ZCPE was not labile to lipid oxidation, evidenced by low lipid hydroperoxides and malondialdehyde levels in the emulsions after thermally accelerated storage. The targeted accumulation of curcumin, a model antioxidant, at the interface was achieved using the ZCP as interfacial vehicle, forming antioxidant shells around dispersed droplets. The oxidative stability of ZCPEs was further improved. Interestingly, no detectable hexanal peak appeared in headspace gas chromatography of the Pickering emulsions. The novel interfacial architecture via the combination of steric hindrance from ZCP-based membrane and interfacial cargo of curcumin endowed the emulsions with favorable oxidative stability. This study opens a promising pathway for producing antioxidant emulsions via the combination of Pickering stabilization mechanism and interfacial delivery of antioxidant.

  5. Preparation of a 6-OH quaternized chitosan derivative through click reaction and its application to novel thermally induced/polyelectrolyte complex hydrogels.

    PubMed

    Chen, Yu; Wang, Fengju; Zhang, Na; Li, Yi; Cheng, Bin; Zheng, Yongfa

    2017-07-11

    In the present study, a chitosan derivative with long chain quaternary ammonium locating grafted at 6-OH (CTS-6-QAS) was designed and prepared via a novel click reaction. The structure and thermal stability of the products of each step were determined with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Rheological tests indicate that CTS-6-QAS possesses excellent thermally induced hydrogel formation property in the presence of β-glycerophosphate (β-GP). Based on these results, a novel thermally induced/polyelectrolyte complex CTS-6-QAS/alginate (SA)/β-GP dual-network hydrogel was designed. This controllable preparation method can avoid the disadvantages of the preparation methods for single thermo-induced hydrogels and polyelectrolyte complex hydrogels, and promote the homogeneity of the hydrogel. Porous sponges were prepared by freeze-drying the CTS-6-QASSA/β-GP hydrogels. The effects of hydrogel preparation conditions on the porous structure and swelling property of the sponges were quantitatively investigated. Tea tree oil (TTO), a natural antibacterial agent, was successfully embedded in the hydrogel due to the lipophilicity of the long chain quaternary ammonium grafted at 6-OH of chitosan. The sustained release of TTO from the hydrogel was studied. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Fabrication and characterization of Pickering emulsions and oil gels stabilized by highly charged zein/chitosan complex particles (ZCCPs).

    PubMed

    Wang, Li-Juan; Yin, Shou-Wei; Wu, Lei-Yan; Qi, Jun-Ru; Guo, Jian; Yang, Xiao-Quan

    2016-12-15

    Herein, we reported a facile method to fabricate ultra-stable, surfactant- and antimicrobial-free Pickering emulsions by designing and modulating emulsions' interfaces via zein/chitosan colloid particles (ZCCPs). Highly charged ZCCPs with neutral wettability were produced by a facile anti-solvent procedure. The ZCCPs were shown to be effective Pickering emulsifiers because the emulsions formed were highly resistant to coalescence over a 9-month storage period. The ZCCPs were adsorbed irreversibly at the interface during emulsification, forming a hybrid network framework in which zein particles were embedded within the chitosan network, yielding ultra-stable food-grade zein/chitosan colloid particles stabilized Pickering emulsions (ZCCPEs). Moreover, stable surfactant-free oil gels were obtained by a one-step freeze-drying process of the precursor ZCCPEs. This distinctive interfacial architecture accounted for the favourable physical performance, and potentially oxidative and microbial stability of the emulsions and/or oil gels. This work opens up a promising route via a food-grade Pickering emulsion-template approach to transform liquid oil into solid-like fats with zero trans-fat formation.

  7. Preparation and characterization of zein/chitosan complex for encapsulation of α-tocopherol, and its in vitro controlled release study.

    PubMed

    Luo, Yangchao; Zhang, Boce; Whent, Monica; Yu, Liangli Lucy; Wang, Qin

    2011-07-01

    Chitosan (CS) nanoparticles coated with zein has been newly demonstrated as a promising encapsulation and delivery system for hydrophilic nutrient with enhanced bioactivities in our previous study. In this study, a hydrophobic nutrient, α-tocopherol (TOC), was successfully encapsulated into zein/CS complex. The fabrication parameters, including zein concentration, zein/CS weight ratio, and TOC loading percentage, were systematically investigated. The physicochemical and structural analysis showed that the electrostatic interactions and hydrogen bonds were major forces responsible for complex formation. The scanning electron microscopy study revealed the spherical nature with smooth surface of complex. TOC encapsulation was also evidenced by differential scanning calorimetry. The particle size and zeta potential of the complex varied from 200 to 800 nm and +22.8 to +40.9 mV, respectively. The kinetic release profile of the TOC showed burst effect followed by slow release. Compared with zein nanoparticles, zein/CS complex provided better protection of TOC release against gastrointestinal conditions, due to CS coatings. Zein/CS complex is believed to be a promising delivery system for supplementation or treatment of hydrophobic nutrients or drugs.

  8. Transfection efficiency of chitosan and thiolated chitosan in retinal pigment epithelium cells: A comparative study

    PubMed Central

    Oliveira, Ana V.; Silva, Andreia P.; Bitoque, Diogo B.; Silva, Gabriela A.; Rosa da Costa, Ana M.

    2013-01-01

    OBJECTIVE: Gene therapy relies on efficient vector for a therapeutic effect. Efficient non-viral vectors are sought as an alternative to viral vectors. Chitosan, a cationic polymer, has been studied for its gene delivery potential. In this work, disulfide bond containing groups were covalently added to chitosan to improve the transfection efficiency. These bonds can be cleaved by cytoplasmic glutathione, thus, releasing the DNA load more efficiently. MATERIALS AND METHODS: Chitosan and thiolated chitosan nanoparticles (NPs) were prepared in order to obtain a NH3+:PO4− ratio of 5:1 and characterized for plasmid DNA complexation and release efficiency. Cytotoxicity and gene delivery studies were carried out on retinal pigment epithelial cells. RESULTS: In this work, we show that chitosan was effectively modified to incorporate a disulfide bond. The transfection efficiency of chitosan and thiolated chitosan varied according to the cell line used, however, thiolation did not seem to significantly improve transfection efficiency. CONCLUSION: The apparent lack of improvement in transfection efficiency of the thiolated chitosan NPs is most likely due to its size increase and charge inversion relatively to chitosan. Therefore, for retinal cells, thiolated chitosan does not seem to constitute an efficient strategy for gene delivery. PMID:23833516

  9. Chitosan nanoparticles conjugate with trypsin and trypsin inhibitor.

    PubMed

    Chanphai, P; Tajmir-Riahi, H A

    2016-06-25

    Chitosan-protein conjugates are widely used in therapeutic drug delivery. We report the bindings of chitosan nanoparticles with trypsin (try) and trypsin inhibitor (tryi), using thermodynamic analysis and multiple spectroscopic methods. Thermodynamic parameters ΔS, ΔH and ΔG showed chitosan-protein bindings occur mainly via H-bonding and van der Waals contacts with trypsin inhibitor forming more stable conjugate than trypsin. As chitosan size increased more stable polymer-protein conjugate was formed. Chitosan complexation induces more perturbations of trypsin inhibitor structure than trypsin with reduction of protein alpha-helix and major increase of random structure. The negative value of ΔG indicates spontaneous protein-chitosan complexation at room temperature. Chitosan nanoparticles can be used to transport trypsin and trypsin inhibitor.

  10. Preparation, characterization and evaluation of antibacterial activity of catechins and catechins-Zn complex loaded β-chitosan nanoparticles of different particle sizes.

    PubMed

    Zhang, Hongcai; Jung, Jooyeoun; Zhao, Yanyun

    2016-02-10

    This study used β-chitosan nanoparticles (β-CS NPs) of different particle sizes to encapsulate catechins (CAT) or CAT-Zn complex by ionic gelation technology. The antibacterial activity of CAT or CAT-Zn complex loaded β-CS NPs against Escherichia coli and Listeria innocua were investigated based on bacterial growth curve, minimum inhibitory concentration (MIC), and minimum bacterial concentration (MBC). Fourier transform infrared spectrometer (FT-IR) was employed to study the incorporation of CAT or CAT-Zn complex into β-CS NPs. The CAT-Zn complex loaded β-CS NPs had particle size of 208-591 nm, polydispersity index (PDI) of 0.377-0.395, and positive Zeta-potential of 39.17-45.62 mV. The CAT-Zn complex loaded β-CS NPs of smaller particle sizes showed higher antibacterial activity than that of larger particle size ones. The MIC and MBC of CAT-Zn complex loaded β-CS NPs of the smallest particle size against L. innocua and E. coli were 0.031 and 0.063 mg/mL, and 0.063 and 0.125 mg/mL, respectively. This study suggested that encapsulation of CAT-Zn complex in β-CS NPs improved the antibacterial activity of CAT and CAT-Zn complex, and the encapsulators have great potential to be used as antibacterial substances for food and other applications through either direct addition or incorporation into packaging materials.

  11. Mathematical modelling of the transport of hydroxypropyl-β-cyclodextrin inclusion complexes of ranitidine hydrochloride and furosemide loaded chitosan nanoparticles across a Caco-2 cell monolayer.

    PubMed

    Sadighi, Armin; Ostad, S N; Rezayat, S M; Foroutan, M; Faramarzi, M A; Dorkoosh, F A

    2012-01-17

    Chitosan nanoparticles (CS-NPs) have been used to enhance the permeability of furosemide and ranitidine hydrochloride (ranitidine HCl) which were selected as candidates for two different biopharmaceutical drug classes having low permeability across Caco-2 cell monolayers. Drugs loaded CS-NPs were prepared by ionic gelation of CS and pentasodium tripolyphosphate (TPP) which added to the drugs inclusion complexes with hydroxypropyl-β-cyclodextrin (HP-βCD). The stability constants for furosemide/HP-βCD and ranitidine HCl/HP-βCD were calculated as 335 M(-1) and 410 M(-1), whereas the association efficiencies (AE%) of the drugs/HP-βCD inclusion complexes with CS-NPs were determined to be 23.0 and 19.5%, respectively. Zetasizer and scanning electron microscopy (SEM) were used to characterise drugs/HP-βCD-NPs size and morphology. Transport of both nano and non-nano formulations of drugs/HP-βCD complexes across a Caco-2 cell monolayer was assessed and fitted to mathematical models. Furosemide/HP-βCD-NPs demonstrated transport kinetics best suited for the Higuchi model, whereas other drug formulations demonstrated power law transportation behaviour. Permeability experiments revealed that furosemide/HP-βCD and ranitidine HCl/HP-βCD nano formulations greatly induce the opening of tight junctions and enhance drug transition through Caco-2 monolayers.

  12. Preparation and pH controlled release of polyelectrolyte complex of poly(L-malic acid-co-D,L-lactic acid) and chitosan.

    PubMed

    Wang, Jie; Ni, Caihua; Zhang, Yanan; Zhang, Meng; Li, Wang; Yao, Bolong; Zhang, Liping

    2014-03-01

    The copolymer of poly(L-malic acid-co-D,L-lactic acid) (PML) was synthesized through a direct polycondensation of L-malic acid (MA) and D,L-lactic acid (LA). Then, a new polyelectrolyte complex (PEC) based on the complexation between the copolymer (PML) and chitosan (CS) was prepared. The PEC formed stable nano particles in aqueous solutions with pH 3-5, and the nano particles had the diameters in a range of 316-590 nm (varied with the components of PML and CS). Doxorubicin (DOX) as a model drug was loaded on the nano particles through the physical adsorption and complexation, and part of DOX formed the secondary particles by self-aggregation. The high drug loading efficiency (16.5%) and the sustained release patterns in acidic media were observed, and the release accelerated in alkaline solutions. The nano particles could be potentially applied as pH sensitive drug vehicles for controlled release.

  13. Gd complexes of diethylenetriaminepentaacetic acid conjugates of low-molecular-weight chitosan oligosaccharide as a new liver-specific MRI contrast agent.

    PubMed

    Huang, Yan; Cao, Bennan; Yang, Xiaolu; Zhang, Qi; Han, Xiangjun; Guo, Ziyi

    2013-05-01

    This study was to describe the synthesis of complexes of gadolinium diethylenetriaminepentaacetic acid conjugates of low-molecular-weight chitosan oligosaccharide Gd-DTPA-CSn (n=6, 8, 11) as a new class of contrast agent as well as its magnetic property in a pilot magnetic resonance imaging. The efficacy of the contrast agent was assessed by measuring the longitudinal relaxivity (r1), FLASH imaging in phantoms in vitro and signal intensity in vivo of the rat abdominal axial imaging. The r1 of Gd-DTPA-CS11 was up to 11.65 mM(-1)·s(-1), which was 3 times higher than that of the analogous MRI contrast agent Gd-DTPA in commercial use. In vivo MR images of rat obtained with Gd-DTPA-CS11 showed strong signal enhancement in liver and the vessels of the liver parenchyma during the extended period of time. The present study suggests that the new synthesized gadolinium complexes can be used as a new class of practical liver-specific MRI contrast agent because of its superior performance compared with Gd-DTPA. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. BaFe12O19-chitosan Schiff-base Ag (I) complexes embedded in carbon nanotube networks for high-performance electromagnetic materials

    PubMed Central

    Zhao, Jie; Xie, Yu; Guan, Dongsheng; Hua, Helin; Zhong, Rong; Qin, Yuancheng; Fang, Jing; Liu, Huilong; Chen, Junhong

    2015-01-01

    The multiwalled carbon nanotubes/BaFe12O19-chitosan (MCNTs/BF-CS) Schiff base Ag (I) complex composites were synthesized successfully by a chemical bonding method. The morphology and structures of the composites were characterized with electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques. Their conductive properties were measured using a four-probe conductivity tester at room temperature, and their magnetic properties were tested by a vibrating sample magnetometer. The results show that the BF-CS Schiff base Ag (I) complexes are embedded into MCNT networks. When the mass ratio of MCNTs and BF-CS Schiff base is 0.95:1, the conductivity, Ms (saturation magnetization), Mr (residual magnetization), and Hc (coercivity) of the BF-CS Schiff base composites reach 1.908 S cm−1, 28.20 emu g−1, 16.66 emu g−1 and 3604.79 Oe, respectively. Finally, a possible magnetic mechanism of the composites has also been proposed. PMID:26218269

  15. Gamma spectrometry and chemical characterization of ceramic seeds with samarium-153 and holmium-166 for brachytherapy proposal.

    PubMed

    Valente, Eduardo S; Campos, Tarcísio P R

    2010-12-01

    Ceramic seeds were synthesized by the sol-gel technique with Si:Sm:Ca and Si:Ho:Ca. One set of seeds was irradiated in the TRIGA type nuclear reactor IPR-R1 and submitted to instrumental neutron activation analysis (INAA), K(0) method, to determine mass percentage concentration of natural samarium and holmium in the seed as well as to determine all existing radionuclides and their activities. Attention was paid to discrimination of Si-31, Ca-40, Ca-45, Ca-47, Ca-49, Sm-145, Sm-155, Sm-153 and Ho-166. A second sample was submitted to atomic emission spectrometry (ICP-AES) also to determine samarium and holmium concentrations in weight. A third sample was submitted to X-ray fluorescence spectrometry to qualitatively determine chemical composition. The measured activity was due to Sm-153 and Ho-166 with a well-characterized gamma spectrum. The X-ray fluorescence spectrum demonstrated that there is no discrepancy in seed composition. The maximum ranges in the water of beta particles from Sm-153 and Ho-166 decay were evaluated, as well as the dose rate and total dose delivered within the volume delimited by the range of the beta particles. The results are relevant for investigation of the viability of producing Sm-153 and Ho-166 radioactive seeds for use in brachytherapy.

  16. [Properties of chitosan and sorption of copper ions from a copper sulfate solution on chitosan].

    PubMed

    Kopecký, F; Kopecká, B; Semjanová, O

    2002-05-01

    The introduction of the paper briefly describes the properties of chitosan and the current utilization of the aminopolysaccharides chitosan, chitin, and their derivatives in pharmaceutical formulations, and in the health services also as sorbents of heavy metals and other substances. The degree of deacetylation (64%) of commercially produced chitosan was estimated from measured IR spectra, and spectrophotometry in the visible region was employed to study the kinetics and equilibrium of the Cu(II) ion sorption from CuSO4 aqueous solutions. Cu(II) sorption on the suspended chitosan was rather slow, it took 8-12 hrs to establish the sorption equilibrium, but the maximum determined sorption capacity, up to 200 mg of copper per 1 g of chitosan, greatly exceeded other adsorbents. A nearly stoichiometric ratio between the sorbed Cu(II) and the chitosan biopolymer structural units as well as decreasing sorption at lower pH (4-5) suggests complex formation of Cu(II) with the solid chitosan. The sorption was reversible, so the raw chitosan under study can be used as a high loading capacity carrier capable of the sorption and subsequent conditional liberation of a considerable amount of Cu(II) ions.

  17. Functional modification of chitosan for biomedical application

    NASA Astrophysics Data System (ADS)

    Tang, Ruogu

    focused on chitosan treatment on titanium surface. We have covalently immobilized chitosan onto titanium (Ti), a widely used implant material, to manage implant-related infection and poor osseointegration that are two of most serious orthopedic implants. The Ti surface was first treated with sulfuric acid and then covalently reacted with chitosan. Surface properties including roughness, contact angle and zeta potential of the samples were markedly increased by the sulfuric acid treatment and the subsequent chitosan immobilization. We have cooperated with the Dr. Ying Deng group's and demonstrated that the chitosan-immobilized Ti showed two novel antimicrobial roles: It prevented the invasion and internalization of bacteria into the osteoblast-like cells; on the other hand, it significantly increased the susceptibility of adherent bacteria to antibiotics. In addition, the SA-Ti and CS-Ti led to a significantly increased osteoblast-likecell attachment, enhanced cell proliferation, and better osteogenic differentiation and mineralization of cells. Chitosan based nanoparticle for drug loading and delivery is also reported in this thesis. By adopting the self-assembly approach, we have prepared alginate/chitosan nanoparticles where the chlorhexidine/cyclodextrin complex is loaded on. The nanoparticles have been proved to be antimicrobial effective and it can bind on cells.

  18. Gd (III) complex conjugate of low-molecular-weight chitosan as a contrast agent for magnetic resonance/fluorescence dual-modal imaging.

    PubMed

    Huang, Yan; Boamah, Peter Osei; Gong, Jianbo; Zhang, Qi; Hua, Mingqing; Ye, Yuzhen

    2016-06-05

    The fusion of molecular and anatomical modalities facilitates more reliable and accurate detection in clinic. In this work, we prepared gadolinium (III) complex Gd-DTPA-FITC-CS11 with magnetic resonance (MR) and fluorescence dual-modal imaging modalities. Gd-DTPA-FITC-CS11 consisted of fluorescein isothiocyanate and low-molecular-weight chitosan (CS11) units conjugated with gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). Gd-DTPA-FITC-CS11 exhibited a higher longitudinal relaxivity (14.09 mM(-1)s(-1)) than the clinical Gd-DTPA (3.85 mM(-1)s(-1)). T1-weighted MR contrast enhancement was also demonstrated the comparability to Gd-DTPA at lower dosage. The binding with bovine serum albumin (BSA) was investigated. The fluorescence of BSA in the presence of Gd-DTPA-FITC-CS11 was weakened due to static quenching mechanism. The conformation of BSA was slightly changed but α-helix was dominant. The binding was entropy-driven and spontaneous and the main contribution was hydrophobic interaction. Our results suggested the potential of Gd-DTPA-FITC-CS11 as an MR/fluorescence dual-modal imaging contrast agent in improving the diagnostic sensitivity and accuracy.

  19. Fabrication of electrochemical sensor for paracetamol based on multi-walled carbon nanotubes and chitosan-copper complex by self-assembly technique.

    PubMed

    Mao, Airong; Li, Hongbo; Jin, Dangqin; Yu, Liangyun; Hu, Xiaoya

    2015-11-01

    An electrochemical sensor for paracetamol based on multi-walled carbon nanotubes and chitosan-copper complex (MWCNTs/CTS-Cu) was fabricated by self-assembly technique. The MWCNTs/CTS-Cu modified GCE showed an excellent electrocatalytic activity for the oxidation of paracetamol, and accelerated electron transfer between the electrode and paracetamol. Under optimal experimental conditions, the differential pulse peak current was linear with the concentration of paracetamol in the range of 0.1-200 μmol L(-1) with a detection limit of 0.024 μmol L(-1). The sensitivity was found to be 0.603 A/mol L(-1). The proposed sensor also showed a high selectivity for paracetamol in the presence of ascorbic acid and dopamine. Moreover, the proposed electrode revealed good reproducibility and stability. The proposed method was successfully applied for the determination of paracetamol in tablet and human serum samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Enhanced nasal mucosal delivery and immunogenicity of anti-caries DNA vaccine through incorporation of anionic liposomes in chitosan/DNA complexes.

    PubMed

    Chen, Liulin; Zhu, Junming; Li, Yuhong; Lu, Jie; Gao, Li; Xu, Huibi; Fan, Mingwen; Yang, Xiangliang

    2013-01-01

    The design of optimized nanoparticles offers a promising strategy to enable DNA vaccines to cross various physiological barriers for eliciting a specific and protective mucosal immunity via intranasal administration. Here, we reported a new designed nanoparticle system through incorporating anionic liposomes (AL) into chitosan/DNA (CS/DNA) complexes. With enhanced cellular uptake, the constructed AL/CS/DNA nanoparticles can deliver the anti-caries DNA vaccine pGJA-P/VAX into nasal mucosa. TEM results showed the AL/CS/DNA had a spherical structure. High DNA loading ability and effective DNA protection against nuclease were proved by gel electrophoresis. The surface charge of the AL/CS/DNA depended strongly on pH environment, enabling the intracellular release of loaded DNA via a pH-mediated manner. In comparison to the traditional CS/DNA system, our new design rendered a higher transfection efficiency and longer residence time of the AL/CS/DNA at nasal mucosal surface. These outstanding features enable the AL/CS/DNA to induce a significantly (p<0.01) higher level of secretory IgA (SIgA) than the CS/DNA in animal study, and a longer-term mucosal immunity. On the other hand, the AL/CS/DNA exhibited minimal cytotoxicity. These results suggest that the developed nanoparticles offer a potential platform for DNA vaccine packaging and delivery for more efficient elicitation of mucosal immunity.

  1. Formulation Development and Evaluation of Drug Release Kinetics from Colon-Targeted Ibuprofen Tablets Based on Eudragit RL 100-Chitosan Interpolyelectrolyte Complexes

    PubMed Central

    Ofokansi, Kenneth Chibuzor; Kenechukwu, Franklin Chimaobi

    2013-01-01

    Colon-targeted drug delivery systems (CTDDSs) could be useful for local treatment of inflammatory bowel diseases (IBDs). In this study, various interpolyelectrolyte complexes (IPECs), formed between Eudragit RL100 (EL) and chitosan (CS), by nonstoichiometric method, and tablets based on the IPECs, prepared by wet granulation, were evaluated as potential oral CTDDSs for ibuprofen (IBF). Results obtained showed that the tablets conformed to compendial requirements for acceptance and that CS and EL formed IPECs that showed pH-dependent swelling properties and prolonged the in vitro release of IBF from the tablets in the following descending order: 3 : 2 > 2 : 3 > 1 : 1 ratios of CS and EL. An electrostatic interaction between the carbonyl (–CO–) group of EL and amino (–NH3+) group of CS of the tablets formulated with the IPECs was capable of preventing drug release in the stomach and small intestine and helped in delivering the drug to the colon. Kinetic analysis of drug release profiles showed that the systems predominantly released IBF in a zero-order manner. IPECs based on CS and EL could be exploited successfully for colon-targeted delivery of IBF in the treatment of IBDs. PMID:23986877

  2. Environmental applications of chitosan and its derivatives.

    PubMed

    Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi

    2015-01-01

    , hydraulic conductivity, permeability, surface area and sorption capacity. Crosslinked chitosan is an excellent sorbent for trace metals especially because of the high flexibility of its structural stability. Sorption of trace metals by chitosan is selective and independent of the size and hardness of metal ions, or the physical form of chitosan (e.g., film, powder and solution). Both -OH and -NH2 groups in chitosan provide vital binding sites for complexing metal cations. At low pH, -NH3 + groups attract and coagulate negatively charged contaminants such as metal oxyanions, humic acids and dye molecules. Grafting certain functional molecules into the chitin structure improves sorption capacity and selectivity for remediating specific metal ions. For example, introducing sulfur and nitrogen donor ligands to chitosan alters the sorption preference for metals. Low molecular weight chitosan derivatives have been used to remediate metal contaminated soil and sediments. They have also been applied in permeable reactive barriers to remediate metals in soil and groundwater. Both chitosan and modified chitosan have been used to phytoremediate metals; however, the mechanisms by which they assist in mobilizing metals are not yet well understood. In addition, microbes have been used in combination with chitosan to remediate metals (e.g., Cu and Zn) in contaminated soils. Chitosan has also been used to remediate organic contaminants, such as oil-based wastewater, dyes, tannins, humic acids, phenols, bisphenoi-A, p-benzoquinone, organo-phosphorus insecticides, among others. Chitosan has also been utilized to develop optical and electrochemical sensors for in-situ detection of trace contaminants. In sensor technology, naturally-derived chitosan is used primarily as an immobilizing agent that results from its enzyme compatibility, and stabilizing effect on nanoparticles. Contaminant-sensing agents, such as enzymes, microbes and nanoparticles, have been homogeneously immobilized in chitosan

  3. Gd-DTPA Adsorption on Chitosan/Magnetite Nanocomposites

    NASA Astrophysics Data System (ADS)

    Pylypchuk, Ie. V.; Kołodyńska, D.; Kozioł, M.; Gorbyk, P. P.

    2016-03-01

    The synthesis of the chitosan/magnetite nanocomposites is presented. Composites were prepared by co-precipitation of iron(II) and iron(III) salts by aqueous ammonia in the 0.1 % chitosan solution. It was shown that magnetite synthesis in the chitosan medium does not affect the magnetite crystal structure. The thermal analysis data showed 4.6 % of mass concentration of chitosan in the hybrid chitosan/magnetite composite. In the concentration range of initial Gd-DTPA solution up to 0.4 mmol/L, addition of chitosan to magnetite increases the adsorption capacity and affinity to Gd-DTPA complex. The Langmuir and Freundlich adsorption models were applied to describe adsorption processes. Nanocomposites were characterized by scanning electron microscopy (SEM), differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and specific surface area determination (ASAP) methods.

  4. Cellular delivery of quantum dot-bound hybridization probe for detection of intracellular pre-microRNA using chitosan/poly(γ-glutamic acid) complex as a carrier.

    PubMed

    Geng, Yao; Lin, Dajie; Shao, Lijia; Yan, Feng; Ju, Huangxian

    2013-01-01

    A quantum dot (QD)-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS)/poly(γ-glutamic acid) (γ-PGA) complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP) via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene delivery system for highly effective cellular uptake and delivery. After the probe was released from CS/γ-PGA complex to the cytoplasm by electrostatic repulsion at intracellular pH, it hybridized with pre-miRNA precursor as target. The formed product was then cleaved by RNase III Dicer, leading to the separation of QDs from Au NPs and fluorescence emission of QDs, which could be detected by confocal microscopic imaging to monitor the amount of the intracellular pre-miRNA precursor. The in vitro assays revealed that the QD-RNA-Au NP was a robust, sensitive and selective probe for quantitative detection of target pre-miRNA. Using MDA-MB231 and MCF-7 breast cancer cells as models, the relative amount of pre-miRNA let-7a could be successfully compared. Since the amount of miRNA is related to the progress and prognosis of cancer, this strategy could be expected to hold promising application potential in medical research and clinical diagnostics.

  5. Chitosan and radiation chemistry

    NASA Astrophysics Data System (ADS)

    Chmielewski, Andrzej G.

    2010-03-01

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under γ-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  6. DNA nanogels composed of chitosan and Pluronic with thermo-sensitive and photo-crosslinking properties.

    PubMed

    Lee, Jung Im; Kim, Hye Sung; Yoo, Hyuk Sang

    2009-05-21

    Chitosan/Pluronic hydrogels were prepared to develop injectable depot systems for gene therapy to enhance local transgene expression at injection sites. Water-soluble chitosan and Pluronic were separately acrylated to prepare photo-crosslinkable polymers. A mixture of acrylated polymers was mixed with plasmid DNA and temperature was elevated to 37 degrees C to physically crosslink polymers to form hydrogels. Chitosan/Pluronic hydrogels were chemically crosslinked by photo-irradiated hydrogels at 37 degrees C. Mass erosion rates and release profiles of photo-crosslinked hydrogels were determined with varying photo-irradiation periods and chitosan contents of the hydrogels. The hydrogels with short photo-irradiation times degraded fast while high chitosan content in the hydrogels accelerated degradation rates. Release rates of plasmid DNA in the hydrogel were also controlled by changing chitosan content and photo-irradiation times. Released plasmid DNA was complexed with released Pluronic or chitosan and could be dissociated by adding sodium dodecyl sulfate. Scanning electron microscopy revealed that released plasmid DNA formed nanoparticles with released Pluronic or chitosan; released chitosan formed a condensed complex with plasmid DNA compared to released Pluronic. Transfection studies employing HEK293 cells showed that released fractions from chitosan/Pluronic hydrogels showed better transfection efficiency than those from Pluronic hydrogels. This result suggested that local transfection efficiencies of plasmid DNA in hydrogels were controlled by chitosan contents in chitosan/Pluronic hydrogels.

  7. Effectiveness of chitosan against wine-related microorganisms.

    PubMed

    Bağder Elmaci, Simel; Gülgör, Gökşen; Tokatli, Mehmet; Erten, Hüseyin; İşci, Asli; Özçelik, Filiz

    2015-03-01

    The antimicrobial action of chitosan against wine related microorganisms, including Lactobacillus plantarum, Saccharomyces cerevisiae, Oeonococcus oeni, Lactobacillus hilgardii, Brettanomyces bruxellensis, Hanseniaspora uvarum and Zygosaccharomyces bailii was examined in laboratory media. In order to assess the potential applicability of chitosan as a microbial control agent for wine, the effect of chitosan, applied individually and/or in combination with sulphur dioxide (SO2), on the growth of microorganisms involved in various stages of winemaking and on the fermentative performance of S. cerevisiae was investigated. Of the seven wine-related microorganisms studied, S. cerevisiae exhibited the strongest resistance to antimicrobial action of chitosan in laboratory media with a minimum inhibitory concentration (MIC) greater than 2 g/L. L. hilgardii, O. oeni and B. bruxellensis were the most susceptible to chitosan since they were completely inactivated by chitosan at 0.2 g/L. The MIC of chitosan for L. plantarum, H. uvarum and Z. bailii was 2, 0.4 and 0.4 g/L, respectively. In wine experiments, it was found that chitosan had a retarding effect on alcoholic fermentation without significantly altering the viability and the fermentative performance of S. cerevisiae. With regard to non-Saccharomyces yeasts (H. uvarum and Z. bailii) involved in winemaking, the early deaths of these yeasts in mixed cultures with S. cerevisiae were not probably due to the antimicrobial action of chitosan but rather due to ethanol produced by the yeasts. The complex interactions between chitosan and wine ingredients as well as microbial interactions during wine fermentation considerably affect the efficacy of chitosan. It was concluded that chitosan was worthy of further investigation as an alternative or complementary preservative to SO2 in wine industry.

  8. Chitosan Microspheres in Novel Drug Delivery Systems

    PubMed Central

    Mitra, Analava; Dey, Baishakhi

    2011-01-01

    The main aim in the drug therapy of any disease is to attain the desired therapeutic concentration of the drug in plasma or at the site of action and maintain it for the entire duration of treatment. A drug on being used in conventional dosage forms leads to unavoidable fluctuations in the drug concentration leading to under medication or overmedication and increased frequency of dose administration as well as poor patient compliance. To minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability various drug delivery and drug targeting systems are currently under development. Handling the treatment of severe disease conditions has necessitated the development of innovative ideas to modify drug delivery techniques. Drug targeting means delivery of the drug-loaded system to the site of interest. Drug carrier systems include polymers, micelles, microcapsules, liposomes and lipoproteins to name some. Different polymer carriers exert different effects on drug delivery. Synthetic polymers are usually non-biocompatible, non-biodegradable and expensive. Natural polymers such as chitin and chitosan are devoid of such problems. Chitosan comes from the deacetylation of chitin, a natural biopolymer originating from crustacean shells. Chitosan is a biocompatible, biodegradable, and nontoxic natural polymer with excellent film-forming ability. Being of cationic character, chitosan is able to react with polyanions giving rise to polyelectrolyte complexes. Hence chitosan has become a promising natural polymer for the preparation of microspheres/nanospheres and microcapsules. The techniques employed to microencapsulate with chitosan include ionotropic gelation, spray drying, emulsion phase separation, simple and complex coacervation. This review focuses on the preparation, characterization of chitosan microspheres and their role in novel drug delivery systems. PMID:22707817

  9. Single crystals of chitosan.

    PubMed

    Cartier, N; Domard, A; Chanzy, H

    1990-10-01

    Lamellar single crystals of chitosan were prepared at 125 degrees C by adding ammonia to a low DP fraction of chitosan dissolved in water. The crystals gave sharp electron diffraction diagrams which could be indexed in an orthorhombic P2(1)2(1)2(1) unit cell with a = 8.07 A, b = 8.44 A, c = 10.34 A. The unit cell contained two anti-parallel chitosan chains and no water molecules. It was found that cellulose microfibrils from Valonia ventricosa could act as nuclei for inducing the crystallization of chitosan on cellulose. This produced a shish-kebab morphology.

  10. Kinetic study on urea uptake with chitosan based sorbent materials.

    PubMed

    Xue, Chen; Wilson, Lee D

    2016-01-01

    A one-pot kinetic uptake study of urea in aqueous solution with various chitosan sorbent materials such as pristine chitosan, cross-linked chitosan with glutaraldehyde from low (C-1) to higher (C-2) glutaraldehyde content, and a Cu(II) complex of a glutaraldehyde cross-linked chitosan material (C-3) is reported herein. The kinetic uptake profiles were analyzed by the pseudo-first order (PFO) and pseudo-second-order (PSO) models, respectively. The uptake rate constant of urea and the sorption capacity (qe) of high molecular weight (HMW) chitosan, C-1, C-2, and C-3 were best described by the PFO model. The uptake rate constant of urea with the various sorbents is listed in ascending order: HMW chitosanchitosan (48.1)≈C-1 (44.7)chitosan displays relatively rapid urea uptake and greater adsorption capacity when compared with pristine chitosan. The observed trends are in agreement with the greater surface accessibility and pore structure properties of cross-linked chitosan based on scanning electron microscopy studies. These results further illustrate the rational design of chitosan-based materials for the controlled uptake of urea in aquatic environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

    PubMed Central

    Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

    2012-01-01

    The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa) has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm) at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery. PMID:23209368

  12. Chitosan and Its Derivatives as Highly Efficient Polymer Ligands.

    PubMed

    Pestov, Alexander; Bratskaya, Svetlana

    2016-03-11

    The polyfunctional nature of chitosan enables its application as a polymer ligand not only for the recovery, separation, and concentration of metal ions, but for the fabrication of a wide spectrum of functional materials. Although unmodified chitosan itself is the unique cationic polysaccharide with very good complexing properties toward numerous metal ions, its sorption capacity and selectivity can be sufficiently increased and turned via chemical modification to meet requirements of the specific applications. In this review, which covers results of the last decade, we demonstrate how different strategies of chitosan chemical modification effect metal ions binding by O-, N-, S-, and P-containing chitosan derivatives, and which mechanisms are involved in binding of metal cation and anions by chitosan derivatives.

  13. Chitosan-Based Multifunctional Platforms for Local Delivery of Therapeutics.

    PubMed

    Hong, Seong-Chul; Yoo, Seung-Yup; Kim, Hyeongmin; Lee, Jaehwi

    2017-03-01

    Chitosan has been widely used as a key biomaterial for the development of drug delivery systems intended to be administered via oral and parenteral routes. In particular, chitosan-based microparticles are the most frequently employed delivery system, along with specialized systems such as hydrogels, nanoparticles and thin films. Based on the progress made in chitosan-based drug delivery systems, the usefulness of chitosan has further expanded to anti-cancer chemoembolization, tissue engineering, and stem cell research. For instance, chitosan has been used to develop embolic materials designed to efficiently occlude the blood vessels by which the oxygen and nutrients are supplied. Indeed, it has been reported to be a promising embolic material. For better anti-cancer effect, embolic materials that can locally release anti-cancer drugs were proposed. In addition, a complex of radioactive materials and chitosan to be locally injected into the liver has been investigated as an efficient therapeutic tool for hepatocellular carcinoma. In line with this, a number of attempts have been explored to use chitosan-based carriers for the delivery of various agents, especially to the site of interest. Thus, in this work, studies where chitosan-based drug delivery systems have successfully been used for local delivery will be presented along with future perspectives.

  14. Chitosan-Based Multifunctional Platforms for Local Delivery of Therapeutics

    PubMed Central

    Hong, Seong-Chul; Yoo, Seung-Yup; Kim, Hyeongmin; Lee, Jaehwi

    2017-01-01

    Chitosan has been widely used as a key biomaterial for the development of drug delivery systems intended to be administered via oral and parenteral routes. In particular, chitosan-based microparticles are the most frequently employed delivery system, along with specialized systems such as hydrogels, nanoparticles and thin films. Based on the progress made in chitosan-based drug delivery systems, the usefulness of chitosan has further expanded to anti-cancer chemoembolization, tissue engineering, and stem cell research. For instance, chitosan has been used to develop embolic materials designed to efficiently occlude the blood vessels by which the oxygen and nutrients are supplied. Indeed, it has been reported to be a promising embolic material. For better anti-cancer effect, embolic materials that can locally release anti-cancer drugs were proposed. In addition, a complex of radioactive materials and chitosan to be locally injected into the liver has been investigated as an efficient therapeutic tool for hepatocellular carcinoma. In line with this, a number of attempts have been explored to use chitosan-based carriers for the delivery of various agents, especially to the site of interest. Thus, in this work, studies where chitosan-based drug delivery systems have successfully been used for local delivery will be presented along with future perspectives. PMID:28257059

  15. Novel High-Viscosity Polyacrylamidated Chitosan for Neural Tissue Engineering: Fabrication of Anisotropic Neurodurable Scaffold via Molecular Disposition of Persulfate-Mediated Polymer Slicing and Complexation

    PubMed Central

    Kumar, Pradeep; Choonara, Yahya E.; du Toit, Lisa C.; Modi, Girish; Naidoo, Dinesh; Pillay, Viness

    2012-01-01

    Macroporous polyacrylamide-grafted-chitosan scaffolds for neural tissue engineering were fabricated with varied synthetic and viscosity profiles. A novel approach and mechanism was utilized for polyacrylamide grafting onto chitosan using potassium persulfate (KPS) mediated degradation of both polymers under a thermally controlled environment. Commercially available high molecular mass polyacrylamide was used instead of the acrylamide monomer for graft copolymerization. This grafting strategy yielded an enhanced grafting efficiency (GE = 92%), grafting ratio (GR = 263%), intrinsic viscosity (IV = 5.231 dL/g) and viscometric average molecular mass (MW = 1.63 × 106 Da) compared with known acrylamide that has a GE = 83%, GR = 178%, IV = 3.901 dL/g and MW = 1.22 × 106 Da. Image processing analysis of SEM images of the newly grafted neurodurable scaffold was undertaken based on the polymer-pore threshold. Attenuated Total Reflectance-FTIR spectral analyses in conjugation with DSC were used for the characterization and comparison of the newly grafted copolymers. Static Lattice Atomistic Simulations were employed to investigate and elucidate the copolymeric assembly and reaction mechanism by exploring the spatial disposition of chitosan and polyacrylamide with respect to the reactional profile of potassium persulfate. Interestingly, potassium persulfate, a peroxide, was found to play a dual role initially degrading the polymers—“polymer slicing”—thereby initiating the formation of free radicals and subsequently leading to synthesis of the high molecular mass polyacrylamide-grafted-chitosan (PAAm-g-CHT)—“polymer complexation”. Furthermore, the applicability of the uniquely grafted scaffold for neural tissue engineering was evaluated via PC12 neuronal cell seeding. The novel PAAm-g-CHT exhibited superior neurocompatibility in terms of cell infiltration owing to the anisotropic porous architecture, high molecular mass mediated robustness, superior

  16. Chitosan-Based Nanomedicine to Fight Genital Candida Infections: Chitosomes

    PubMed Central

    Andersen, Toril; Mishchenko, Ekaterina; Flaten, Gøril Eide; Sollid, Johanna U. Ericson; Mattsson, Sofia; Tho, Ingunn; Škalko-Basnet, Nataša

    2017-01-01

    Vaginal infections are associated with high recurrence, which is often due to a lack of efficient treatment of complex vaginal infections comprised of several types of pathogens, especially fungi and bacteria. Chitosan, a mucoadhesive polymer with known antifungal effect, could offer a great improvement in vaginal therapy; the chitosan-based nanosystem could both provide antifungal effects and simultaneously deliver antibacterial drugs. We prepared chitosan-containing liposomes, chitosomes, where chitosan is both embedded in liposomes and surface-available as a coating layer. For antimicrobial activity, we entrapped metronidazole as a model drug. To prove that mucoadhesivness alone is not sufficient for successful delivery, we used Carbopol-containing liposomes as a control. All vesicles were characterized for their size, zeta potential, entrapment efficiency, and in vitro drug release. Chitosan-containing liposomes were able to assure the prolonged release of metronidazole. Their antifungal activity was evaluated in a C. albicans model; chitosan-containing liposomes exhibited a potent ability to inhibit the growth of C. albicans. The presence of chitosan was crucial for the system’s antifungal activity. The antifungal efficacy of chitosomes combined with antibacterial potential of the entrapped metronidazole could offer improved efficacy in the treatment of mixed/complex vaginal infections. PMID:28273850

  17. Chitosan-Based Nanomedicine to Fight Genital Candida Infections: Chitosomes.

    PubMed

    Andersen, Toril; Mishchenko, Ekaterina; Flaten, Gøril Eide; Sollid, Johanna U Ericson; Mattsson, Sofia; Tho, Ingunn; Škalko-Basnet, Nataša

    2017-03-04

    Vaginal infections are associated with high recurrence, which is often due to a lack of efficient treatment of complex vaginal infections comprised of several types of pathogens, especially fungi and bacteria. Chitosan, a mucoadhesive polymer with known antifungal effect, could offer a great improvement in vaginal therapy; the chitosan-based nanosystem could both provide antifungal effects and simultaneously deliver antibacterial drugs. We prepared chitosan-containing liposomes, chitosomes, where chitosan is both embedded in liposomes and surface-available as a coating layer. For antimicrobial activity, we entrapped metronidazole as a model drug. To prove that mucoadhesivness alone is not sufficient for successful delivery, we used Carbopol-containing liposomes as a control. All vesicles were characterized for their size, zeta potential, entrapment efficiency, and in vitro drug release. Chitosan-containing liposomes were able to assure the prolonged release of metronidazole. Their antifungal activity was evaluated in a C. albicans model; chitosan-containing liposomes exhibited a potent ability to inhibit the growth of C. albicans. The presence of chitosan was crucial for the system's antifungal activity. The antifungal efficacy of chitosomes combined with antibacterial potential of the entrapped metronidazole could offer improved efficacy in the treatment of mixed/complex vaginal infections.

  18. Use of chitosan for chromium removal from exhausted tanning baths.

    PubMed

    Cesaro, Raffaele; Fabbricino, Massimiliano; Lanzetta, Rosa; Mancino, Anna; Naviglio, Biagio; Parrilli, Michelangelo; Sartorio, Roberto; Tomaselli, Michele; Tortora, Gelsomina

    2008-01-01

    A novel approach, based on chitosan heavy-metal sequestrating ability, is proposed for chromium(III) removal from spent tanning liquor. Experimental results, obtained at lab-scale using real wastewater, are presented and discussed. Resulting efficiencies are extremely high, and strongly dependent on chitosan dose and pH value. Comparative analyses with other polysaccharides is also carried out showing that amine groups are more efficient than carboxyl and sulphate ones. Chromium recovery from sorption complexes and chitosan regeneration is finally proposed to optimize the whole process.

  19. Formation of positively charged microcapsules based on chitosan-lecithin interactions.

    PubMed

    Magdassi, S; Bach, U; Mumcuoglu, K Y

    1997-01-01

    The formation of microcapsules which contain rosemary oil, is herewith described. The process is based on two steps: (a) formation of oil-in-water emulsions, by using lecithin as emulsifier, thus imparting negative charges on the oil droplets; (b) addition of a cationic biopolymer, chitosan, in conditions that favor the formation of an insoluble chitosan-lecithin complex. Zeta potential measurements revealed that addition of very low concentrations of chitosan to lecithin stabilized emulsions, led to reversal of charge. At a suitable pH range the chitosan precipitated around the oil droplets, forming positively charged microcapsules. The chitosan-lecithin insoluble complex is composed of a 1:1 molar ratio of the chitosan monomeric unit and lecithin, as evaluated by elementary analysis and turbidity measurements.

  20. Construction of new biopolymer (chitosan)-based pincer-type Pd(II) complex and its catalytic application in Suzuki cross coupling reactions

    NASA Astrophysics Data System (ADS)

    Baran, Talat; Menteş, Ayfer

    2017-04-01

    In this paper we described the fabrication, characterization and application of a new biopolymer (chitosan)-based pincer-type Pd(II) catalyst in Suzuki cross coupling reactions using a non-toxic, cheap, eco-friendly and practical method. The catalytic activity tests showed remarkable product yields as well as TON (19800) and TOF (330000) values with a small catalyst loading. In addition, the catalyst indicated good recyclability in the Suzuki C-C reaction. This biopolymer supported catalyst can be used with various catalyst systems due to its unique properties, such as being inert, green in nature, low cost and chemically durable.

  1. Chitosan based oligoamine polymers: synthesis, characterization, and gene delivery.

    PubMed

    Lu, Bo; Wang, Chang-Fang; Wu, De-Qun; Li, Cao; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2009-07-01

    A series of chitosan-based oligoamine polymers was synthesized from N-maleated chitosan (NMC) via Michael addition with diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and linear polyethylenimine (M(n) 423), respectively. The resulted polymers exhibited well binding ability to condense plasmid DNA to form complexes with size ranging from 200 to 600 nm when the polymer/DNA weight ratio was above 7. The polymer/DNA complexes observed by scanning electron microscopy (SEM) exhibited a compact and spherical morphology. The cytotoxicity assay showed that the synthesized polymers were less toxic than that of PEI(25 K). The gene transfection effect of resulted polymers was evaluated in 293T and HeLa cells, and the results showed that the gene transfection efficiency of these polymers was better than that of chitosan. Moreover, the transfection efficiency was dependent on the length of the oligoamine side chains and the molecular weight of the chitosan derivatives.

  2. Release of triamcinolone acetonide from mucoadhesive polymer composed of chitosan and poly(acrylic acid) in vitro.

    PubMed

    Ahn, Jae-Soon; Choi, Hoo-Kyun; Chun, Myong-Kwan; Ryu, Jei-Man; Jung, Jae-Hee; Kim, Yue-Un; Cho, Chong-Su

    2002-03-01

    Transmucosal drug delivery (TMD) system using mucoadhesive polymer has been recently interested due to the rapid onset of action, high blood level, avoidance of the first-pass effect and the exposure of the drug to the gastrointestinal tract. A novel mucoadhesive polymer complex composed of chitosan and poly(acrylic acid) (PAA) was prepared by template polymerization of acrylic acid in the presence of chitosan for the TMD system. Triamcinolone acetonide (TAA) was loaded into the chitosan/PAA polymer complex film. TAA was evenly dispersed in chitosan, PAA polymer complex film without interaction with polymer complex. Release behavior of TAA from the mucoadhesive polymer film was dependent on time, pH, loading content of drug, and chitosan PAA ratio. The analysis of the drug release from the mucoadhesive film showed that TAA might be released from the chitosan/PAA polymer complex film through non-Fickian diffusion mechanism.

  3. Local Antibiotic Delivery Using Tailorable Chitosan Sponges: The Future of Infection Control?

    DTIC Science & Technology

    2010-09-01

    2005;26: 5983–5990. 20. Ong S, Wu J, Moochhala SM, et al. Development of a chitosan -based wound dressing with improved hemostatic and antimicrobial ...ORIGINAL ARTICLE Local Antibiotic Delivery Using Tailorable Chitosan Sponges: The Future of Infection Control? Daniel J. Stinner, MD,* Scott P. Noel...a biodegradable and biocompatible chitosan sponge to minimize infection by delivering local antibiotics within the wound. Methods: A complex

  4. [Chitosan in topical preparations].

    PubMed

    Matusová, D; Truplová, E

    2007-06-01

    Chitosan in topical preparations Within the framework of experimental work at the Department of Pharmaceutical Technology of Slovak Medical University, "insect" chitin obtained from the buff-tailed bumblebee (Bombus terrestris) was processed to produce dosage forms and compared with commercially available chitin, or chitosan, obtained from shrimps (Pandalus borealus). The paper aimed to find whether insect chitin, or chitosan, possessed similar technological properties as commercially available and for topical preparations used products. Samples were prepared containing chitin, or chitosan, of different origin, 0.25 and 0.5% in a gel base. In some gels the gel base was acidified with citric acid (in an amount of 0.75%) or lactic acid (1%) to improve the mechanical properties of foils. All samples were well applicable and after drying a relatively resistant transparent layer was formed on the skin. All samples could be made to produce elastic foils, which after moistening clung well to the skin. Both chitin and chitosan obtained from the bodies of buff-tailed bumblebees differed from reference materials obtained from shrimps by the degree of deacetylation, possessed different technological properties, e.g., finer fibres, were more fragile, and when wet, they could be disintegrated better, which is obvious also from the results of microscopic evaluation. Chitosan prepared from chitin SAV (insect) possessed substantially finer particles in the dosage form. The evaluation of the flow properties of the prepared samples revealed that except Sample I (gel base alone) they are time-dependent tixotropic systems. Whereas chitin gels did not show any antimicrobial effect (which is apparently connected with bad solubility of chitin), gels with chitosan showed this activity. A more marked effect was observed in the strains of Staphylococcus aureus and Pseudomonas aeruginosa, and in Escherichia coli it was weaker. The paper reports the first tentative results of comparisons of

  5. Functional gene silencing mediated by chitosan/siRNA nanocomplexes

    NASA Astrophysics Data System (ADS)

    Ji, A. M.; Su, D.; Che, O.; Li, W. S.; Sun, L.; Zhang, Z. Y.; Yang, B.; Xu, F.

    2009-10-01

    Chitosan/siRNA nanoparticles to knock down FHL2 gene expression were reported in this work. The physicochemical properties such as particle size, surface charge, morphology and complex stability of chitosan nanoparticle-incorporated siRNA were evaluated. Nanoparticles which were formulated with chitosan/siRNA exhibited irregular, lamellar and dendritic structures with a hydrodynamic radius size of about 148 nm and net positive charges with zeta-potential value of 58.5 mV. The knockdown effect of the chitosan/siRNA nanoparticles on gene expression in FHL2 over-expressed human colorectal cancer Lovo cells was investigated. The result showed that FHL2 siRNA formulated within chitosan nanoparticles could knock down about 69.6% FHL2 gene expression, which is very similar to the 68.8% reduced gene expression when siRNA was transfected with liposome Lipofectamine. Western analysis further showed significant FHL-2 protein expression reduced by the chitosan/siRNA nanoparticles. The results also showed that blocking FHL2 expression by siRNA could also inhibit the growth and proliferation of human colorectal cancer Lovo cells. The current results demonstrated that chitosan-based siRNA nanoparticles were a very efficient delivery system for siRNA in vivo as previously reported.

  6. Phosphate uptake studies of cross-linked chitosan bead materials.

    PubMed

    Mahaninia, Mohammad H; Wilson, Lee D

    2017-01-01

    A systematic experimental study is reported that provides a molecular based understanding of cross-linked chitosan beads and their adsorption properties in aqueous solution containing phosphate dianion (HPO4(2-)) species. Synthetically modified chitosan using epichlorohydrin and glutaraldehyde cross-linkers result in surface modified beads with variable hydrophile-lipophile character and tunable HPO4(2-) uptake properties. The kinetic and thermodynamic adsorption properties of cross-linked chitosan beads with HPO4(2-) species were studied in aqueous solution. Complementary structure and physicochemical characterization of chitosan beads via potentiometry, Raman spectroscopy, DSC, and dye adsorption measurements was carried out to establish structure-property relationships. The maximum uptake (Qm) of bead systems with HPO4(2-) at equilibrium was 52.1mgg(-1); whereas, kinetic uptake results for chitosan bead/phosphate systems are relatively rapid (0.111-0.113min(-1)) with an intraparticle diffusion rate-limiting step. The adsorption process follows a multi-step pathway involving inner- and outer-sphere complexes with significant changes in hydration. Phosphate uptake strongly depends on the composition and type of cross-linker used for preparation of chitosan beads. The adsorption isotherms and structural characterization of bead systems illustrate the role of surface charge, hydrophile-lipophile balance, adsorption site accessibility, and hydration properties of the chitosan bead surface. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Tuning the formation and stability of microcapsules by environmental conditions and chitosan structure.

    PubMed

    Ren, Ying; Xie, Hongguo; Liu, Xiaocen; Yang, Fan; Yu, Weiting; Ma, Xiaojun

    2016-10-01

    The goal of this work is to tune the formation and stability of the alginate-chitosan (AC) polyelectrolyte complexes (PECs) and microcapsules. Particularly, we explore the role of the conformation of chitosan on its interaction with alginate to understand the mechanism underpinning their interactions at the molecular level. Reducing the charge density by increasing pH will increase the compactness of chitosan, the values of the enthalpy (H) and stoichiometry (N) of binding between chitosan and alginate. Consequently, chitosan has advantage in being adsorbed on alginate beads to form microcapsules, including the binding rate and binding amount. Though the total heat release remain similar in the range of ionic strength, chitosan diffuses much easier into alginate hydrogels when in higher ionic strength. Increasing pH and ionic strength both help AC microcapsules to have higher stability. The results indicate that the formation and stability of AC microcapsules are related to the rigidity and conformations of chitosan molecules. After increasing acetylation degree (DA) of chitosan, the binding rate of chitosan and mechanical strength of AC microcapsules are both reduced. This work demonstrates the versatility and feasibility of tuning the formation and stability of polysaccharide microcapsules by physical factors and chitosan chemical structures.

  8. The Use of chitosan in The Formation of Silver Nanoparticles, Chitosanic Nanoparticles and Fibrous Structures

    NASA Astrophysics Data System (ADS)

    Abdelgawad, Abdelrahman Mohamed

    antibacterial testing of the nanofiber mats were performed according to AATCC-100 protocol. PVA/CS/CIA system was found to have superior antibacterial action over PVA/CS/thiolchitosan counterparts. In the last part of the thesis, chitosan nanoparticles were prepared; for the first time in the literature instead of Tripolyphosphate (TPP), via ionic crosslinking with hexametaphosphate (HMP). A systematic study was conducted to apply the chitosan/HMP nanoparticles as a hydrophilic drug carrier for protein drugs. Chitosan/HMP systems were found to be unstable in the acidic medium. The optimum complexation conditions were established as pH 5 and the nanoparticles showed better stability at 21 days. Chitosan concentration plays an important role in improving particles stability by increasing zeta potential; however, it adversely affects the particles size. BSA loading capacity of chitosan/HMP was higher, 96.3%, than that of TPP, 91.87%, equivalents due to larger average size.

  9. Antimicrobial properties of chitosan and mode of action: a state of the art review.

    PubMed

    Kong, Ming; Chen, Xi Guang; Xing, Ke; Park, Hyun Jin

    2010-11-15

    Owing to its high biodegradability, and nontoxicity and antimicrobial properties, chitosan is widely-used as an antimicrobial agent either alone or blended with other natural polymers. To broaden chitosan's antimicrobial applicability, comprehensive knowledge of its activity is necessary. The paper reviews the current trend of investigation on antimicrobial activities of chitosan and its mode of action. Chitosan-mediated inhibition is affected by several factors can be classified into four types as intrinsic, environmental, microorganism and physical state, according to their respective roles. In this review, different physical states are comparatively discussed. Mode of antimicrobial action is discussed in parts of the active compound (chitosan) and the target (microorganisms) collectively and independently in same complex. Finally, the general antimicrobial applications of chitosan and perspectives about future studies in this field are considered.

  10. Chitosan-based nanocarriers for antimalarials

    NASA Astrophysics Data System (ADS)

    Dreve, Simina; Kacso, Iren; Popa, Adriana; Raita, Oana; Bende, A.; Borodi, Gh.; Bratu, I.

    2012-02-01

    The objective of this research was to synthesize and characterize chitosan-based liquid and solid materials with unique absorptive and mechanical properties as carriers for quinine - one of the most used antimalarial drug. The use of chitosan (CTS) as base in polyelectrolyte complex systems, to prepare solid release systems as sponges is presented. The preparation by double emulsification of CTS hydrogels carrying quinine as anti-malarial drug is reported. The concentration of quinine in the CTS hydrogel was 0.08 mmol. Chitosan - drug loaded hydrogel was used to generate solid sponges by freeze-drying at -610°C and 0.09 atm. Structural investigations of the solid formulations were done by Fourier-transformed infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-VIS), spectrofluorimetry, differential scanning calorimetry (DSC) and X-ray diffractometry. The results indicated that the drug molecule is forming temporary chelates in CTS hydrogels and sponges. Electron paramagnetic resonance (EPR) demonstrates the presence of free radicals in a wide range and the antioxidant activity for chitosan - drug supramolecular cross-linked assemblies.

  11. Modification of chitosan by using samarium for potential use in drug delivery system.

    PubMed

    Kusrini, Eny; Arbianti, Rita; Sofyan, Nofrijon; Abdullah, Mohd Aidil A; Andriani, Fika

    2014-01-01

    In the presence of hydroxyl and amine groups, chitosan is highly reactive; therefore, it could be used as a carrier in drug delivery. For this study, chitosan-Sm complexes with different concentrations of samarium from 2.5 to 25 wt.% have been successfully synthesized by the impregnation method. Chitosan combined with Sm3+ ions produced a drug carrier material with fluorescence properties; thus, it could also be used as an indicator of drug release with ibuprofen (IBU) as a model drug. We evaluated the spectroscopic and interaction properties of chitosan and Sm3+ ions, the interaction of chitosan-Sm matrices with IBU as a model drug, and the effect of Sm3+ ions addition on the chitosan ability to adsorb the drug. The result showed that the hypersensitive fluorescence intensity of chitosan-Sm (2.5 wt.%) is higher than the others, even though the adsorption efficiency of chitosan-Sm 2.5wt.% is lower (29.75%) than that of chitosan-Sm 25 wt.% (33.04%). Chitosan-Sm 25 wt.% showed the highest efficiency of adsorption of ibuprofen (33.04%). In the release process of ibuprofen from the chitosan-Sm-IBU matrix, the intensity of orange fluorescent properties in the hypersensitive peak of 4G5/2→6H7/2 transition at 590 nm was observed. Fluorescent intensity increased with the cumulative amount of IBU released; therefore, the release of IBU from the Sm-modified chitosan complex can be monitored by the changes in fluorescent intensity. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Uncoupling chitosanase production from chitosan.

    PubMed

    Brzezinski, Ryszard

    2011-01-01

    There is a growing interest in chitosanases as enzymatic tools to hydrolyze chitosan into bioactive forms: low molecular weight chitosan (LMWC) or chitosan oligosaccharides (CHOS). However chitosanases are still expensive and methods of large-scale production of these enzymes are not yet established. The article reviews the approaches used for chitosanase production in various bacterial hosts, pointing out the difficulties resulting from the necessity to include chitosan into the medium composition. A mutated Streptomyces host allows for the efficient production of several chitosanases originating from actinobacteria in the absence of chitosan as inducer.

  13. Chitosan in plant protection.

    PubMed

    El Hadrami, Abdelbasset; Adam, Lorne R; El Hadrami, Ismail; Daayf, Fouad

    2010-03-30

    Chitin and chitosan are naturally-occurring compounds that have potential in agriculture with regard to controlling plant diseases. These molecules were shown to display toxicity and inhibit fungal growth and development. They were reported to be active against viruses, bacteria and other pests. Fragments from chitin and chitosan are known to have eliciting activities leading to a variety of defense responses in host plants in response to microbial infections, including the accumulation of phytoalexins, pathogen-related (PR) proteins and proteinase inhibitors, lignin synthesis, and callose formation. Based on these and other proprieties that help strengthen host plant defenses, interest has been growing in using them in agricultural systems to reduce the negative impact of diseases on yield and quality of crops. This review recapitulates the properties and uses of chitin, chitosan, and their derivatives, and will focus on their applications and mechanisms of action during plant-pathogen interactions.

  14. Chitosan in Plant Protection

    PubMed Central

    El Hadrami, Abdelbasset; Adam, Lorne R.; El Hadrami, Ismail; Daayf, Fouad

    2010-01-01

    Chitin and chitosan are naturally-occurring compounds that have potential in agriculture with regard to controlling plant diseases. These molecules were shown to display toxicity and inhibit fungal growth and development. They were reported to be active against viruses, bacteria and other pests. Fragments from chitin and chitosan are known to have eliciting activities leading to a variety of defense responses in host plants in response to microbial infections, including the accumulation of phytoalexins, pathogen-related (PR) proteins and proteinase inhibitors, lignin synthesis, and callose formation. Based on these and other proprieties that help strengthen host plant defenses, interest has been growing in using them in agricultural systems to reduce the negative impact of diseases on yield and quality of crops. This review recapitulates the properties and uses of chitin, chitosan, and their derivatives, and will focus on their applications and mechanisms of action during plant-pathogen interactions. PMID:20479963

  15. Molecular interactions in gelatin/chitosan composite films.

    PubMed

    Qiao, Congde; Ma, Xianguang; Zhang, Jianlong; Yao, Jinshui

    2017-11-15

    Gelatin and chitosan were mixed at different mass ratios in solution forms, and the rheological properties of these film-forming solutions, upon cooling, were studied. The results indicate that the significant interactions between gelatin and chitosan promote the formation of multiple complexes, reflected by an increase in the storage modulus of gelatin solution. Furthermore, these molecular interactions hinder the formation of gelatin networks, consequently decreasing the storage modulus of polymer gels. Both hydrogen bonds and electrostatic interactions are formed between gelatin and chitosan, as evidenced by the shift of the amide-II bands of polymers. X-ray patterns of composite films indicate that the contents of triple helices decrease with increasing chitosan content. Only one glass transition temperature (Tg) was observed in composite films with different composition ratios, and it decreases gradually with an increase in chitosan proportion, indicating that gelatin and chitosan have good miscibility and form a wide range of blends. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Recent advances in drugs and prodrugs design of chitosan.

    PubMed

    Vinsova, J; Vavrikova, E

    2008-01-01

    The aim of this review is to outline the recent advances in chitosan molecular modeling, especially its usage as a prodrug or drug in a field of antibacterial, anticarcinogenic and antioxidant activity. Polymeric materials like peptides, polysaccharides and other natural products have recently attracted attention as biodegradabile drug carriers. They can optimize clinical drug application, minimize the undesirable drug properties and improve drug efficiency. They are used for the slow release of effective components as depot forms, to improve membrane permeability, solubility and site-specific targeting. Chitosan is such a prospective cationic polysaccharide which has shown number of functions in many fields, including bio medicinal, pharmaceutical, preservative, microbial and others. This article discusses the structure characteristics of chitosan, a number of factors such as degree of polymerization, level of deacetylation, types of quarternisation, installation of various hydrophilic substituents, metal complexation, and combination with other active agents. Biodegradable, non-toxic and non-allergenic nature of chitosan encourages its potential use as a carrier for drug delivery systems in all above mentioned targets. The use of chitosan prodrug conjugates is aimed at the site-specific transport to the target cells use, for example, a spacer tetrapeptide Gly-Phe-Leu-Gly, promotion of drug incorporation into cells via endocytosis, hybridization or synergism of two types of drugs or a drug with a bioactive carrier. The design of chitosan macromolecule prodrugs is also discussed.

  17. A novel method for synthesizing PEGylated chitosan nanoparticles: strategy, preparation, and in vitro analysis

    PubMed Central

    Malhotra, Meenakshi; Lane, Ciaran; Tomaro-Duchesneau, Catherine; Saha, Shyamali; Prakash, Satya

    2011-01-01

    Preparation of poly (ethylene glycol) (PEG)-grafted chitosan is essential for improving the biocompatibility and water solubility of chitosan. Presently available methods for this have limitations. This article describes a new method for preparing PEGylated chitosan nanoparticles. For this chitosan was chemoselectively modified using a novel scheme at the C6 position of its repeating units by PEG. The amine groups at the C2 position of the chitosan were protected using phthalic anhydride. Sodium hydride was used to catalyze the etherification reaction between chlorinated chitosan and methyl-PEG, and PEG-grafted chitosan was successfully synthesized. Each step was characterized using 13C nuclear magnetic resonance and Fourier transform infrared. After PEGylation the phthaloylated chitosan was successfully deprotected using hydrazine monohydrate. The synthetic scheme proposed demonstrates a new method for grafting PEG onto chitosan with a moderate degree of substitution. The potential of this polymer in nanoparticle preparation using an ionic gelation method and its gene delivery potentials were investigated by complexing a fluorescently labeled control siRNA. The result showed that suitable nanoparticles can be synthesized using this polymer and that they have capacity to carry genes and provide adequate transfection efficacy with no toxicity when tested in neuronal cells. PMID:21562608

  18. In vitro evaluation of chitosan-EDTA conjugate polyplexes as a nanoparticulate gene delivery system.

    PubMed

    Loretz, Brigitta; Bernkop-Schnürch, Andreas

    2006-01-01

    It was the purpose of this study to evaluate the potential of different molecular-weight chitosan-EDTA conjugates as a carrier matrix for nanoparticulate gene delivery systems. Covalent binding of EDTA to more than one chitosan chain provides a cross-linked polymer that is anticipated to produce stabilized particles. pDNA/chitosan-EDTA particles, generated via coazervation, were characterized in size and zeta potential by electrophoretic light scattering and electron microscopy. Stability was investigated at different pH values by enzymatic degradation and subsequent gel retardation assay. Lactate dehydrogenase assay was performed to determine toxicity. Furthermore, transfection efficiency into Caco-2 cells was assessed using a beta-galactosidase reporter gene. Chitosan-EDTA produced from low-viscous chitosan with 68% amino groups being modified by the covalent attachment of EDTA showed the highest complexing efficacy resulting in nanoparticles of 43 nm mean size and exhibiting a zeta potential of +6.3 mV. These particles were more stable at pH 8 than chitosan control particles. The cytotoxicity of chitosan-EDTA particles was below 1% over a time period of 4 hours. These new nanoplexes showed 35% improved in vitro transfection efficiency compared with unmodified chitosan nanoparticles. According to these results, the chitosan-EDTA conjugate may be a promising polymer for gene transfer.

  19. Action of chitosan against Xanthomonas pathogenic bacteria isolated from Euphorbia pulcherrima.

    PubMed

    Wang, Yanli; Li, Liping; Li, Bin; Wu, Guoxing; Tang, Qiaomei; Ibrahim, Muhammad; Li, Hongye; Xie, Guanlin; Sun, Guochang

    2012-06-07

    The antibacterial activity and mechanism of two kinds of chitosan were investigated against twelve Xanthomonas strains recovered from Euphorbia pulcherrima. Results indicated that both chitosans markedly inhibited bacterial growth based on OD loss. Furthermore, the release of DNA and RNA from three selected strains was increased by both chitosans. However, the release of intracellular proteins was inhibited by both chitosans at different concentration and incubation times, except chitosan A at 0.1 mg/mL for 0.5 h incubation and 0.2 mg/mL for 2.0 h incubation increased the release of proteins, indicating the complexity of the interaction and cell membranes, which was affected by incubation time, bacterial species, chitosan type and concentration. Transmission electron microscopic observations revealed that chitosan caused changes in protoplast concentration and surface morphology. In some cells, the membranes and walls were badly distorted and disrupted, while other cells were enveloped by a thick and compact ribbon-like layer. The contrary influence on cell morphology may explain the differential effect in the release of material. In addition, scanning electron microscope and biofilm formation test revealed that both chitosans removed biofilm biomass. Overall, this study showed that membrane and biofilm play an important role in the antibacterial mechanism of chitosan.

  20. A mechanistic based approach for enhancing buccal mucoadhesion of chitosan.

    PubMed

    Meng-Lund, Emil; Muff-Westergaard, Christian; Sander, Camilla; Madelung, Peter; Jacobsen, Jette

    2014-01-30

    Mucoadhesive buccal drug delivery systems can enhance rapid drug absorption by providing an increased retention time at the site of absorption and a steep concentration gradient. An understanding of the mechanisms behind mucoadhesion of polymers, e.g. chitosan, is necessary for improving the mucoadhesiveness of buccal formulations. The interaction between chitosan of different chain lengths and porcine gastric mucin (PGM) was studied using a complex coacervation model (CCM), isothermal titration calorimetry (ITC) and a tensile detachment model (TDM). The effect of pH was assessed in all three models and the approach to add a buffer to chitosan based drug delivery systems is a means to optimize and enhance buccal drug absorption. The CCM demonstrated optimal interactions between chitosan and PGM at pH 5.2. The ITC experiments showed a significantly increase in affinity between chitosan and PGM at pH 5.2 compared to pH 6.3 and that the interactions were entropy driven. The TDM showed a significantly increase in strength of adhesion between chitosan discs and an artificial mucosal surface at pH 5.2 compared to pH 6.8, addition of PGM increased the total work of adhesion by a factor of 10 as compared to the wetted surface without PGM. These findings suggest that chitosan and PGM are able to interact by electrostatic interactions and by improving the conditions for electrostatic interactions, the adhesion between chitosan and PGM becomes stronger. Also, the three complementary methods were utilized to conclude the pH dependency on mucoadhesiveness.

  1. The effect of Ni(2+) and Cu(2+) on the photocatalytic degradation of dyes by the chitosan-TiO(2) complex.

    PubMed

    Zhao, Xiaolei; Xiao, Gang; Zhang, Xin; Su, Haijia; Tan, Tianwei

    2012-09-01

    The present research combines biosorption and photocatalysis in a functional TiO(2)-immobilized chitosan adsorbent (CTA). CTA can degrade organic pollutants and adsorb metal ions simultaneously. Target pollutants were dyes of cationic (rhodamine B, Rh.B) and anionic (methyl orange, MO) nature, with Ni(2+) and Cu(2+) selected as heavy metals. The presence of Ni(2+) or Cu(2+) improved the degradation ability of CTA for MO, but inhibited the degradation of Rh.B, with Cu(2+) exhibiting stronger effects than Ni(2+). There was no significant difference in CTA activity when the metal ions were pre-adsorbed or when they coexisted in the solution with the organic dyes. Protons in the reaction system affected the degradation performance in a similar way for Ni(2+) and Cu(2+) leading to a different effect on the degradation for MO and Rh.B. An X-ray photoelectron spectroscopy analysis of the binding energies of the metal ions on the surface in the presence of the cationic or anionic dyes explained the different behaviors. Since anionic and cationic dyes possess chromogenic groups of different charges, they adversely affect the production of OH• radicals when coexisting with Cu(2+) or Ni(2+).

  2. Evaluation of diethylenetriaminepentaacetic acid-manganese(II) complexes modified by narrow molecular weight distribution of chitosan oligosaccharides as potential magnetic resonance imaging contrast agents.

    PubMed

    Huang, Yan; Zhang, Xiaoyan; Zhang, Qi; Dai, Xueqin; Wu, Jingbo

    2011-05-01

    Novel conjugates of narrow molecular weight distribution of chitosan oligosaccharides (CSn; n=6, 8, 11) with manganese-diethylenetriaminepentaacetic acid (Mn-DTPA) as potential magnetic resonance imaging (MRI) contrast agents were synthesized. The structures were characterized by means of Fourier transform infrared spectra, (13)C nuclear magnetic resonance, size exclusion chromatography and inductively coupled plasma atomic emission spectrometry. The characterization results showed that Mn-DTPA was successfully linked to aminated CSn by an amide function. The magnetic properties were characterized by in vitro and T(1)-weighted FLASH image experiments. Relaxivities studies indicated that Mn-DTPA-CSn (n=8, 11) provided higher relaxivity, either in aqueous or bovine serum albumin solution (0.725 mM), than commercial contrast agent Gd-DTPA. The stability results showed that Mn-DTPA-CSn in aqueous were stable enough to prevent Mn(II) ions from releasing. The preliminary in vitro and T(1)-weighted FLASH image studies suggested that Mn-DTPA-CSn had the advantage of becoming promising MRI contrast agents. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Amperometric immunosensor for α-fetoprotein antigen in human serum based on co-immobilizing dinuclear copper complex and gold nanoparticle doped chitosan film

    NASA Astrophysics Data System (ADS)

    Gan, Ning; Meng, Ling Hua; Wang, Feng

    2009-09-01

    A sensitive amperometric immunosensor for α-fetoprotein (AFP), a tumor marker for the diagnosis of hepatocellular carcinoma (HCC), was constructed, The immunosensor is prepared by co-immobilizing [Cu2(phen)2Cl2] (μ-Cl)2 (CuL), nano-Au/Chitosan(Chit) composite, horseradish peroxidase (HRP) and AFP antibody(anti-AFP) on a glassy carbon electrode (GCE). Firstly, CuL was irreversibly absorb on GCE electrode through π-π stacking interaction; then nano-Au/Chit composite was immobilized onto the electrode because of its excellent membrane-forming ability, finally HRP and anti-AFP was adsorbed onto the surface of the gold nanoparticles to construct GCE | CuL/nanoAu-chit/HRP/anti-AFP immunosensor. The preparation procedure of the electrode was characterized by electrochemical and spectroscopy method. The results showed that this immunosensor exhibited an excellent electrocatalytic response to the reduction of hydrogen peroxide (H2O2) without the aid of an electron mediator, offers a high-sensitivity (1710 nA · ng-1 · ml-1) for the detection of AFP and has good correlation for detection of AFP in the range of 0.2 to 120.0 ng/ml with a detection limit of 0.05 ng/ml. The biosensor showed high selectivity as well as good stability and reproductivity.

  4. Preparation and analysis of multilayer composites based on polyelectrolyte complexes

    NASA Astrophysics Data System (ADS)

    Petrova, V. A.; Orekhov, A. S.; Chernyakov, D. D.; Baklagina, Yu. G.; Romanov, D. P.; Kononova, S. V.; Volod'ko, A. V.; Ermak, I. M.; Klechkovskaya, V. V.; Skorik, Yu. A.

    2016-11-01

    A method for preparing multilayer film composites based on chitosan has been developed by the example of polymer pairs: chitosan-hyaluronic acid, chitosan-alginic acid, and chitosan-carrageenan. The structure of the composite films is characterized by X-ray diffractometry and scanning electron microscopy. It is shown that the deposition of a solution of hyaluronic acid, alginic acid, or carrageenan on a chitosan gel film leads to the formation of a polyelectrolyte complex layer at the interface, which is accompanied by the ordering of chitosan chains in the surface region; the microstructure of this layer depends on the nature of contacting polymer pairs.

  5. Chitosan preparations for wounds and burns: antimicrobial and wound-healing effects.

    PubMed

    Dai, Tianhong; Tanaka, Masamitsu; Huang, Ying-Ying; Hamblin, Michael R

    2011-07-01

    Since its discovery approximately 200 years ago, chitosan, as a cationic natural polymer, has been widely used as a topical dressing in wound management owing to its hemostatic, stimulation of healing, antimicrobial, nontoxic, biocompatible and biodegradable properties. This article covers the antimicrobial and wound-healing effects of chitosan, as well as its derivatives and complexes, and its use as a vehicle to deliver biopharmaceuticals, antimicrobials and growth factors into tissue. Studies covering applications of chitosan in wounds and burns can be classified into in vitro, animal and clinical studies. Chitosan preparations are classified into native chitosan, chitosan formulations, complexes and derivatives with other substances. Chitosan can be used to prevent or treat wound and burn infections not only because of its intrinsic antimicrobial properties, but also by virtue of its ability to deliver extrinsic antimicrobial agents to wounds and burns. It can also be used as a slow-release drug-delivery vehicle for growth factors to improve wound healing. The large number of publications in this area suggests that chitosan will continue to be an important agent in the management of wounds and burns.

  6. Chitosan preparations for wounds and burns: antimicrobial and wound-healing effects

    PubMed Central

    Dai, Tianhong; Tanaka, Masamitsu; Huang, Ying-Ying; Hamblin, Michael R

    2011-01-01

    Since its discovery approximately 200 years ago, chitosan, as a cationic natural polymer, has been widely used as a topical dressing in wound management owing to its hemostatic, stimulation of healing, antimicrobial, nontoxic, biocompatible and biodegradable properties. This article covers the antimicrobial and wound-healing effects of chitosan, as well as its derivatives and complexes, and its use as a vehicle to deliver biopharmaceuticals, antimicrobials and growth factors into tissue. Studies covering applications of chitosan in wounds and burns can be classified into in vitro, animal and clinical studies. Chitosan preparations are classified into native chitosan, chitosan formulations, complexes and derivatives with other substances. Chitosan can be used to prevent or treat wound and burn infections not only because of its intrinsic antimicrobial properties, but also by virtue of its ability to deliver extrinsic antimicrobial agents to wounds and burns. It can also be used as a slow-release drug-delivery vehicle for growth factors to improve wound healing. The large number of publications in this area suggests that chitosan will continue to be an important agent in the management of wounds and burns. PMID:21810057

  7. Investigation of the complex structure, comparative DNA-binding and DNA cleavage of two water-soluble mono-nuclear lanthanum(III) complexes and cytotoxic activity of chitosan-coated magnetic nanoparticles as drug delivery for the complexes

    NASA Astrophysics Data System (ADS)

    Asadi, Zahra; Nasrollahi, Neda; Karbalaei-Heidari, Hamidreza; Eigner, Vaclav; Dusek, Michal; Mobaraki, Nabiallah; Pournejati, Roya

    2017-05-01

    Two water-soluble mono-nuclear macrocyclic lanthanum(III) complexes of 2,6-diformyl-4-methylphenol with 1,3-diamino-2-propanol (C1) or 1,3-propylenediamine (C2) were synthesized and characterized by UV-Vis, FT-IR, 13C and 1H NMR spectroscopy and elemental analysis. C1 complex was structurally characterized by single-crystal X-ray diffraction, which revealed that the complex was mononuclear and ten-coordinated. The coordination sites around lanthanum(III) were occupied with a five-dentate ligand, two bidentate nitrates, and one water molecule. The interaction of complexes with DNA was studied in buffered aqueous solution at pH 7.4. UV-Vis absorption spectroscopy, emission spectroscopy, circular dichroism (CD) and viscometric measurements provided clear evidence of the intercalation mechanism of binding. The obtained intrinsic binding constants (Kb) 9.3 × 103 and 1.2 × 103 M- 1 for C1 and C2, respectively confirmed that C1 is better intercalator than C2. The DNA docking studies suggested that the complexes bind with DNA in a groove binding mode with the binding affinity of C1 > C2. Moreover, agarose gel electrophoresis study of the DNA-complex for both compounds revealed that the C1 intercalation cause ethidium bromide replacement in a competitive manner which confirms the suggested mechanism of binding. Finally, the anticancer experiments for the treated cancerous cell lines with both synthesized compounds show that these hydrophilic molecules need a suitable carrier to pass through the hydrophobic nature of cell membrane efficiently.

  8. Surface grafted chitosan gels. Part II. Gel formation and characterization.

    PubMed

    Liu, Chao; Thormann, Esben; Claesson, Per M; Tyrode, Eric

    2014-07-29

    Responsive biomaterial hydrogels attract significant attention due to their biocompatibility and degradability. In order to make chitosan based gels, we first graft one layer of chitosan to silica, and then build a chitosan/poly(acrylic acid) multilayer using the layer-by-layer approach. After cross-linking the chitosan present in the polyelectrolyte multilayer, poly(acrylic acid) is partly removed by exposing the multilayer structure to a concentrated carbonate buffer solution at a high pH, leaving a surface-grafted cross-linked gel. Chemical cross-linking enhances the gel stability against detachment and decomposition. The chemical reaction between gluteraldehyde, the cross-linking agent, and chitosan was followed in situ using total internal reflection Raman (TIRR) spectroscopy, which provided a molecular insight into the complex reaction mechanism, as well as the means to quantify the cross-linking density. The amount of poly(acrylic acid) trapped inside the surface grafted films was found to decrease with decreasing cross-linking density, as confirmed in situ using TIRR, and ex situ by Fourier transform infrared (FTIR) measurements on dried films. The responsiveness of the chitosan-based gels with respect to pH changes was probed by quartz crystal microbalance with dissipation (QCM-D) and TIRR. Highly cross-linked gels show a small and fully reversible behavior when the solution pH is switched between pH 2.7 and 5.7. In contrast, low cross-linked gels are more responsive to pH changes, but the response is fully reversible only after the first exposure to the acidic solution, once an internal restructuring of the gel has taken place. Two distinct pKa's for both chitosan and poly(acrylic acid), were determined for the cross-linked structure using TIRR. They are associated with populations of chargeable groups displaying either a bulk like dissociation behavior or forming ionic complexes inside the hydrogel film.

  9. The spacer arm length in cell-penetrating peptides influences chitosan/siRNA nanoparticle delivery for pulmonary inflammation treatment

    NASA Astrophysics Data System (ADS)

    Jeong, Eun Ju; Choi, Moonhwan; Lee, Jangwook; Rhim, Taiyoun; Lee, Kuen Yong

    2015-11-01

    Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of R9Gn-chitosan/siRNA nanoparticles were investigated in vitro. Increasing the spacing arm length did not significantly affect the complex formation between R9Gn-chitosan and siRNA. However, R9G10-chitosan was much more effective in delivering genes both in vitro and in vivo compared with non-modified chitosan (without the peptide) and R9-chitosan (without the spacer arm). Chitosan derivatives modified with oligoarginine containing a spacer arm can be considered as potential delivery vehicles for various genes.Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of

  10. DNA interaction of [Cu(dmp)(phen-dion)] (dmp=4,7 and 2,9 dimethyl phenanthroline, phen-dion=1,10-phenanthroline-5,6-dion) complexes and DNA-based electrochemical biosensor using chitosan-carbon nanotubes composite film.

    PubMed

    Kashanian, Soheila; Khodaei, Mohammad Mehdi; Roshanfekr, Hamideh; Peyman, Hossein

    2013-10-01

    The interaction of two new water-soluble [Cu(4,7-dmp)(phen-dione)Cl]Cl (1) and [Cu(2,9-dmp)(phen-dione)Cl]Cl (2) which dmp is dimethyl-1,10-phenanthroline and phen-dion represents 1,10-phenanthroline-5,6-dion, with DNA in solution and immobilized DNA on a chitosan-carbon nanotubes composite modified glassy carbon electrode were investigated by cyclic voltammetry and UV-Vis spectroscopy techniques. In solution interactions, spectroscopic and electrochemical evidences indicate outside binding of these complexes. To clarify the binding mode of complexes, it was done competition studies with Hoechst and Neutral red as groove binder and intercalative probes, respectively. All these results indicating that, these two complexes (1) and (2) interact with DNA via groove binding and partially intercalative modes, respectively. The electrochemical characterization experiments showed that the nanocomposite film of chitosan-carbon nanotubes could effectively immobilize DNA and greatly improve the electron-transfer reactions of the electroactive molecules that latter finding is the result of strong interactions between captured DNA and Cu complexes. This result indicates that these complexes could be noble candidates as hybridization indicators in further studies. At the end, these new complexes showed excellent antitumor activity against K562 (human chronic myeloid leukemia) cell lines. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. DNA interaction of [Cu(dmp)(phen-dion)] (dmp = 4,7 and 2,9 dimethyl phenanthroline, phen-dion = 1,10-phenanthroline-5,6-dion) complexes and DNA-based electrochemical biosensor using chitosan-carbon nanotubes composite film

    NASA Astrophysics Data System (ADS)

    Kashanian, Soheila; Khodaei, Mohammad Mehdi; Roshanfekr, Hamideh; Peyman, Hossein

    2013-10-01

    The interaction of two new water-soluble [Cu(4,7-dmp)(phen-dione)Cl]Cl (1) and [Cu(2,9-dmp)(phen-dione)Cl]Cl (2) which dmp is dimethyl-1,10-phenanthroline and phen-dion represents 1,10-phenanthroline-5,6-dion, with DNA in solution and immobilized DNA on a chitosan-carbon nanotubes composite modified glassy carbon electrode were investigated by cyclic voltammetry and UV-Vis spectroscopy techniques. In solution interactions, spectroscopic and electrochemical evidences indicate outside binding of these complexes. To clarify the binding mode of complexes, it was done competition studies with Hoechst and Neutral red as groove binder and intercalative probes, respectively. All these results indicating that, these two complexes (1) and (2) interact with DNA via groove binding and partially intercalative modes, respectively. The electrochemical characterization experiments showed that the nanocomposite film of chitosan-carbon nanotubes could effectively immobilize DNA and greatly improve the electron-transfer reactions of the electroactive molecules that latter finding is the result of strong interactions between captured DNA and Cu complexes. This result indicates that these complexes could be noble candidates as hybridization indicators in further studies. At the end, these new complexes showed excellent antitumor activity against K562 (human chronic myeloid leukemia) cell lines.

  12. Postharvest chitosan-g-salicylic acid application alleviates chilling injury and preserves cucumber fruit quality during cold storage.

    PubMed

    Zhang, Youzuo; Zhang, Meiling; Yang, Huqing

    2015-05-01

    The effect of salicylic acid with and without chitosan, or a chitosan-g-salicylic acid complex, on chilling injury and post-harvest quality of cucumber stored at 2 °C for 12 days plus 2 days at 20 °C was investigated. The results showed the chitosan-g-salicylic acid coating inhibited chilling injury better than salicylic acid alone or with chitosan. Chitosan-g-salicylic acid also reduced weight loss and respiration rate, limited increases in malondialdehyde content and electrolyte leakage, and maintained higher total soluble solids, chlorophyll and ascorbic acid content. Furthermore, this coating increased the endogenous salicylic acid concentrations and antioxidant enzyme activities including superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase in cucumber during storage. Our study suggests that chitosan-g-salicylic acid alleviated chilling injury in cucumber through sustained-release of salicylic acid and the higher antioxidant enzymes concentrations.

  13. Microwave-assisted facile synthesis of a new tri-block chitosan conjugate with improved mucoadhesion.

    PubMed

    Badhe, Ravindra V; Nanda, Rabindra K; Chejara, Dharmesh R; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

    2015-10-05

    A new chitosan-based tri-block conjugate, O-PEG-chitosan-N-cysteine was synthesized using microwave irradiation. For synthesis of this derivative, chitosan was modified to a PEG-chitosan conjugate followed by PEG-chitosan-cysteine using 6-O PEGylation and 2-N-thiolation, respectively. The synthesized derivative was characterized using various analytical techniques such as FT-IR and (1)H NMR spectroscopy. The conjugate was also analyzed for its biochemical, biodegradation and mucoadhesive properties. The modified chitosan conjugate exhibited improved mucoadhesion behavior (14.0 h) with greater biodegradation compared to the parent polymer (6.3h). The in silico modeling corroborated with the in vitro study demonstrating a stable complex between mucin and O-PEG-chitosan-N-cysteine conjugate (ΔE=-60.100 kcal/mol) compared to mucin and chitosan conjugate. The synthesis proposed herein, involves the use of microwave irradiation which causes a substantial reduction in the reaction time (approximately 2.30 h) compared to conventional method (35 h).

  14. Chitosan and alginate types of bio-membrane in fuel cell application: An overview

    NASA Astrophysics Data System (ADS)

    Shaari, N.; Kamarudin, S. K.

    2015-09-01

    The major problems of polymer electrolyte membrane fuel cell technology that need to be highlighted are fuel crossovers (e.g., methanol or hydrogen leaking across fuel cell membranes), CO poisoning, low durability, and high cost. Chitosan and alginate-based biopolymer membranes have recently been used to solve these problems with promising results. Current research in biopolymer membrane materials and systems has focused on the following: 1) the development of novel and efficient biopolymer materials; and 2) increasing the processing capacity of membrane operations. Consequently, chitosan and alginate-based biopolymers seek to enhance fuel cell performance by improving proton conductivity, membrane durability, and reducing fuel crossover and electro-osmotic drag. There are four groups of chitosan-based membranes (categorized according to their reaction and preparation): self-cross-linked and salt-complexed chitosans, chitosan-based polymer blends, chitosan/inorganic filler composites, and chitosan/polymer composites. There are only three alginate-based membranes that have been synthesized for fuel cell application. This work aims to review the state-of-the-art in the growth of chitosan and alginate-based biopolymer membranes for fuel cell applications.

  15. Carboxymethyl chitosan-poly(amidoamine) dendrimer core-shell nanoparticles for intracellular lysozyme delivery.

    PubMed

    Zhang, Xiaoyang; Zhao, Jun; Wen, Yan; Zhu, Chuanshun; Yang, Jun; Yao, Fanglian

    2013-11-06

    Intracellular delivery of native, active proteins is challenging due to the fragility of most proteins. Herein, a novel polymer/protein polyion complex (PIC) nanoparticle with core-shell structure was prepared. Carboxymethyl chitosan-grafted-terminal carboxyl group-poly(amidoamine) (CM-chitosan-PAMAM) dendrimers were synthesized by amidation and saponification reactions. (1)H NMR was used to characterize CM-chitosan-PAMAM dendrimers. The TEM images and results of lysozyme loading efficiency indicated that CM-chitosan-PAMAM dendrimers could self-assemble into core-shell nanoparticles, and lysozyme was efficiently encapsulated inside the core of CM-chitosan-PAMAM dendrimer nanoparticles. Activity of lysozyme was completely inhibited by CM-chitosan-PAMAM Dendrimers at physiological pH, whereas it was released into the medium and exhibited a significant enzymatic activity in an acidic intracellular environment. Moreover, the CM-chitosan-PAMAM dendrimer nanoparticles did not exhibit significant cytotoxicity in the range of concentrations below 3.16 mg/ml. The results indicated that these CM-chitosan-PAMAM dendrimers have excellent properties as highly potent and non-toxic intracellular protein carriers, which would create opportunities for novel applications in protein delivery.

  16. Electrospun chitosan/PEDOT nanofibers.

    PubMed

    Kiristi, Melek; Oksuz, Aysegul Uygun; Oksuz, Lutfi; Ulusoy, Seyhan

    2013-10-01

    Plasma-modified chitosan and poly(3,4-ethylenedioxythiophene) were blended to obtain conducting nanofibers with polyvinyl alcohol as a supporting polymer at various volumetric ratios by electrospinning method. Chemical compositions and molecular interactions among nanofiber blend components were determined using Fourier transform infrared spectroscopy (FTIR). The conducting blends containing plasma-modified chitosan resulted in a superior antibacterial activity and thinner fiber formation than those containing chitosan without plasma-modification. The obtained nanofiber diameters of plasma-modified chitosan were in the range of 170 to 200 nm and those obtained from unmodified chitosan were in the range of 190 to 246 nm. The electrical and electrochemical properties of nanofibers were also investigated by four-point probe conductivity and cyclic voltammetry measurements.

  17. Alginate-chitosan coacervation in production of artificial seeds.

    PubMed

    Tay, L F; Khoh, L K; Loh, C S; Khor, E

    1993-08-05

    Survival of secondary embryoids of winter oilseed rape (Brassica napus ssp. oleifera cv. Primor) has been used as an assay for the development of artificial seeds involving complex coacervation of alginate (polyanion) with chitosan (polycation). Germination frequency of 100% was achieved for encapsulated embryoids when alginate formed the inner matrix and chitosan the outer layer. When the matrix makeup was reversed, there was no germination of embryoids. The artificial seeds produced were hardened in dilute alkaline solutions of NaOH and Ca(OH)(2). An optimum setting time could be selected based on a quantitative measurement of resistance of hardened capsules to compression and the germination frequency of the encapsulated embryoids.

  18. Investigation of Chitosan for Decorporation of 60Co in the Rat

    SciTech Connect

    Levitskaia, Tatiana G.; Creim, Jeffrey A.; Curry, Terry L.; Luders, Teresa; Morris, James E.; Sinkov, Sergey I.; Woodstock, Angela D.; Thrall, Karla D.

    2009-08-01

    Purpose: The reported investigation is a part of our on-going research aimed at identifying effective in vivo non-toxic decorporation agents and developing new therapies to treat internal contamination with radionuclides. The non-toxic nature of chitosan makes it an especially attractive candidate for unsupervised treatment of the general population in case of radiological/nuclear emergency. In this study, chemically unmodified water-soluble chitosan oligosaccharide of low molecular weight was tested for decorporation of cobalt-60 (Co-60) using a rodent model. Methods: Affinity of chitosan oligosaccharide for Co(II) was tested in vitro under conditions of physiological pH range and ionic strength using combined spectrophotometric and potentiometric titration techniques. Fisher F344 rat model was used for in vivo studies. To evaluate effect of chitosan on ingested Co-60, animals received single oral dose of Co-60 chloride (7 – 13.2 kBq per animal) followed by oral administration of chitosan material (288 – 366 mg per kg body weight); chitosan dosing was repeated in 24 hours. Chitosan was also tested for removal of internalized Co-60. In this study, Co-60 single intravenous injection (7 – 8 kBq per animal) was followed by repetitive oral (300 mg per kg body weight) or intravenous (195 mg per kg body weight) administration of the chitosan material once daily for 5 days. Control animal groups received a single dose of Co-60 without chelator treatment. Excreta was collected daily. Tissues were collected postmortem and analyzed for radioactivity by gamma counting technique. Results: In vitro experiments confirmed binding of Co(II) by chitosan oligosaccharide, formation of mixed cobalt-chitosan-hydroxide complex species was proposed, and stability constants was calculated. Control in vivo studies indicated that about 71% of ingested Co-60 was excreted in two days predominantly through the gastrointestinal tract. For intravenously administered Co-60, urinal excretion

  19. Structural, Thermal, Physical, Mechanical, and Barrier Properties of Chitosan Films with the Addition of Xanthan Gum.

    PubMed

    de Morais Lima, Maria; Carneiro, Lucia Cesar; Bianchini, Daniela; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa; Prentice, Carlos; Moreira, Angelita da Silveira

    2017-03-01

    Films based on chitosan and xanthan gum were prepared using casting technique aiming to investigate the potential of these polymers as packaging materials. Six formulations of films were studied varying the proportion of chitosan and xanthan gum: 100:0 (chitosan:xanthan gum, w/w, C100XG0 film); 90:10 (chitosan:xanthan gum, w/w, C90XG10 film); 80:20 (chitosan:xanthan gum, w/w, C80XG20 film); 70:30 (chitosan:xanthan gum, w/w, C70XG30 film); 60:40 (chitosan:xanthan gum, w/w, C60XG40 film); and 50:50 (chitosan:xanthan gum, w/w, C50XG50 film). The total quantity of solids (chitosan and xanthan gum) in the filmogenic solution was 1.5 g per 100 mL of aqueous solution for all treatments, according to the proportion of each polymer. The films were evaluated by their functional groups, structural, thermal, morphological, physical, mechanical, and barrier properties. All films have presented endothermic peaks in the range of 122 to 175 °C and broad exothermic peaks above 200 °C, which were assigned to the melting temperature and thermal decomposition, respectively. These results demonstrated that films with xanthan gum have the highest Tm and Δm H. The films containing higher content of xanthan gum show also the highest tensile strength and the lowest elongation. Xanthan gum addition did not affect the water vapor permeability, solubility, and moisture of films. This set of data suggests the formation of chitosan-xanthan complexes in the films. © 2017 Institute of Food Technologists®.

  20. Ionically crosslinked Ad/chitosan nanocomplexes processed by electrospinning for targeted cancer gene therapy.

    PubMed

    Park, Yeonah; Kang, Eunah; Kwon, Oh-Joon; Hwang, Taewon; Park, Hongkwan; Lee, Jung Min; Kim, Jung Hyun; Yun, Chae-Ok

    2010-11-20

    For effective cancer gene therapy, systemic administration of tumor-targeting adenoviral (Ad) complexes is critical for delivery to both primary and metastatic lesions. Electrospinning was used to generate nanocomplexes of Ad, chitosan, poly(ethylene glycol) (PEG), and folic acid (FA) for effective FA receptor-expressing tumor-specific transduction. The chemical structure of the Ad/chitosan-PEG-FA nanocomplexes was characterized by NMR and FT-IR, and the diameter and surface charge were analyzed by dynamic light scattering and zeta potentiometry, respectively. The average size of Ad/chitosan-PEG-FA nanocomplexes was approximately 140 nm, and the surface charge was 2.1 mV compared to -4.9 mV for naked Ad. Electron microscopy showed well-dispersed, individual Ad nanocomplexes without aggregation or degradation. Ad/chitosan nanocomplexes retained biological activity without impairment of the transduction efficiency of naked Ad. The transduction efficiency of Ad/chitosan-PEG-FA was increased as a function of FA ratio in FA receptor-expressing KB cells, but not in FA receptor-negative U343 cells, demonstrating FA receptor-targeted viral transduction. In addition, the transduction efficiency of Ad/chitosan-PEG-FA was 57.2% higher than chitosan-encapsulated Ad (Ad/chitosan), showing the superiority of FA receptor-mediated endocytosis for viral transduction. The production of inflammatory cytokine, IL-6 from macrophages was significantly reduced by Ad/chitosan-PEG-FA nanocomplexes, implying the potential for use in systemic administration. These results clearly demonstrate that cancer cell-targeted viral transduction by Ad/chitosan-PEG-FA nanocomplexes can be used effectively for metastatic tumor treatment with reduced immune reaction against Ad.

  1. Synthesis and properties of isomeric pyridyl-containing chitosan derivatives.

    PubMed

    Bratskaya, S Yu; Azarova, Yu A; Portnyagin, A S; Mechaev, A V; Voit, A V; Pestov, A V

    2013-11-01

    Here we report on the method of synthesis in gel of a new heterocyclic aminopolymer-N-2-(4-pyridyl)ethylchitosan (4-PEC) via direct addition of 4-vinylpyridine to chitosan that yields a derivative with the substitution degree (DS) up to 0.8. The comparison of reactivity, thermal, spectroscopic, and sorption properties of a new derivative and its isomer N-2-(2-pyridyl)ethylchitosan (2-PEC) is presented. 2-PEC has higher sorption capacity and forms more stable chelates with [PdCl4](2-) and [PtCl6](2-) ions than 4-PEC, but the latter shows higher selectivity to noble metals ions in the presence of Cl(-) ions. A gradual increase of the sorption capacities and the affinity coefficient for Cu(2+) and Ni(2+) in the row chitosan<4-PEC<2-PEC was related to the increase of electron donor nitrogen atoms content and chelating properties of 2-PEC. A nearly negligible increase of the 4-PEC sorption capacity for Ag(+), as compared to plain chitosan, was suggested to be dependent on the difference in complexation models for 2-PEC and 4-PEC derivatives. The density functional theory (DFT) calculations have shown that the "pendant" model of the complex with Ag(I) is energetically favorable only for 2-PEC derivative, while in cases of chitosan and 4-PEC only "bridge" complexes can be formed that results in lower sorption capacity.

  2. The spacer arm length in cell-penetrating peptides influences chitosan/siRNA nanoparticle delivery for pulmonary inflammation treatment.

    PubMed

    Jeong, Eun Ju; Choi, Moonhwan; Lee, Jangwook; Rhim, Taiyoun; Lee, Kuen Yong

    2015-12-21

    Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of R9Gn-chitosan/siRNA nanoparticles were investigated in vitro. Increasing the spacing arm length did not significantly affect the complex formation between R9Gn-chitosan and siRNA. However, R9G10-chitosan was much more effective in delivering genes both in vitro and in vivo compared with non-modified chitosan (without the peptide) and R9-chitosan (without the spacer arm). Chitosan derivatives modified with oligoarginine containing a spacer arm can be considered as potential delivery vehicles for various genes.

  3. Quaternized chitosan oligomers as novel gene delivery vectors in epithelial cell lines.

    PubMed

    Thanou, M; Florea, B I; Geldof, M; Junginger, H E; Borchard, G

    2002-01-01

    Quaternized modifications of chitosan present characteristics that might be useful in DNA condensing and efficient gene delivery. Trimethylated chitosan (TMO) was synthesized from oligomeric chitosan (<20 monomer units). TMOs spontaneously formed complexes (chitoplexes) with RSV-alpha3 luciferase plasmid DNA. These complexes were characterized by photon correlation spectroscopy and were investigated for their ability to transfect COS-1 and Caco-2 cell lines in the presence and absence of fetal calf serum and compared with DOTAP (N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium sulphate) lipoplexes. Additionally, their effect on the viability of the respective cell cultures was investigated using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. Results showed that quaternized chitosan oligomers were able to condense DNA and form complexes with a size ranging from 200 to 500 nm. Chitoplexes proved to transfect COS-1 cells, however, to a lesser extent than DOTAP-DNA lipoplexes. The quaternized oligomer derivatives appeared to be superior to oligomeric chitosan. The presence of fetal calf serum (FCS) did not affect the transfection efficiency of the chitoplexes, whereas the transfection efficiency of DOTAP DNA complexes was decreased. Cells remained 100% viable in the presence of chitosan oligomers whereas viability of DOTAP treated cells decreased to approximately 50% in both cell lines. Both DOTAP-DNA lipoplexes and chitoplexes resulted in less transfection efficiency in Caco-2 cell cultures than in COS-1 cells; however quaternized chitosan oligomers proved to be superior to DOTAP. Effects on the viability of Caco-2 cells were similar to the effects observed in COS-1 cells. We conclude that trimethylated chitosan-DNA complexes present suitable characteristics and the potential to be used as gene delivery vectors.

  4. Microscopic Examination of Chitosan Polyphosphate Beads with Entrapped Spores of the Biocontrol Agent, Streptomyces melanosporofaciens EF-76

    NASA Astrophysics Data System (ADS)

    Jobin, Guy; Grondin, Gilles; Couture, Geneviève; Beaulieu, Carole

    2005-04-01

    Spores of the biocontrol agent, Streptomyces melanosporofaciens EF-76, were entrapped by complex coacervation in beads composed of a macromolecular complex (MC) of chitosan and polyphosphate. A proportion of spores entrapped in beads survived the entrapment procedure as shown by treating spores from chitosan beads with a dye allowing the differentiation of live and dead cells. The spore-loaded chitosan beads could be digested by a chitosanase, suggesting that, once introduced in soil, the beads would be degraded to release the biocontrol agent. Spore-loaded beads were examined by optical and scanning electron microscopy because the release of the biological agent depends on the spore distribution in the chitosan beads. The microscopic examination revealed that the beads had a porous surface and contained a network of inner microfibrils. Spores were entrapped in both the chitosan microfibrils and the bead lacuna.

  5. Encapsulation of testosterone by chitosan nanoparticles.

    PubMed

    Chanphai, P; Tajmir-Riahi, H A

    2017-05-01

    The loading of testosterone by chitosan nanoparticles was investigated, using multiple spectroscopic methods, thermodynamic analysis, TEM images and modeling. Thermodynamic parameters showed testosterone-chitosan bindings occur mainly via H-bonding and van der Waals contacts. As polymer size increased more stable steroid-chitosan conjugates formed and hydrophobic contact was also observed. The loading efficacy of testosterone-nanocarrier was 40-55% and increased as chitosan size increased. Testosterone encapsulation markedly alters chitosan morphology. Chitosan nanoparticles are capable of transporting testosterone in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Comparative investigation of the binding characteristics of poly-L-lysine and chitosan on alginate hydrogel.

    PubMed

    Ren, Ying; Xie, Hongguo; Liu, Xiaocen; Bao, Jie; Yu, Weiting; Ma, Xiaojun

    2016-03-01

    The binding properties of poly-L-lysine and chitosan to alginate have been evaluated quantitatively and compared. Poly-L-lysine bound to alginate hydrogel more rapidly than chitosan as poly-L-lysine has a smaller molar hydrodynamic volume. In addition, poly-L-lysine showed a much higher binding capacity (6.14:1) for alginate hydrogel beads than chitosan (2.71:1), and a little higher binding stoichiometry (0.58) to sodium alginate molecules in solution than chitosan (0.49). An exothermic heat of alginate-poly-L-lysine complexes formation of 2.02 kJ/mol was detected. For alginate-chitosan complexes, the binding enthalpy has been seen to be -3.49 kJ/mol. The stability of the polyelectrolyte complexes was related to their binding enthalpy. The alginate-poly-L-lysine complexes could be disintegrated and rebuilt. By contrast, chitosan was bound with alginate in a steady state. These results provide fundamental insights regarding the structure and property relationships of macromolecules, and will be helpful in designing and selecting appropriate polymers.

  7. Effect of chitosan on the heat stability of whey protein solution as a function of pH.

    PubMed

    Zhao, Zhengtao; Xiao, Qian

    2017-03-01

    Chitosan was reported to interact with proteins through electrostatic interactions. Their interaction was influenced by pH, which was not fully characterized. Further research on the interactions between protein and chitosan at different pH and their influence on the thermal denaturation of proteins is necessary. In this research, the effect of chitosan on the heat stability of whey protein solution at pH 4.0-6.0 was studied. At pH 4.0, a small amount chitosan was able to prevent the heat-induced denaturation and aggregation of whey protein molecules. At higher pH values (5.5 and 6.0), whey proteins complexed with chitosan through electrostatic attraction. The formation of chitosan-whey protein complexes at pH 5.5 improved the heat stability of dispersions and no precipitation could be detected up to 20 days. The dispersion with a medium amount of chitosan (chitosan:whey protein 1:5) produced the most stable particles, which had an average radius of 135 ± 14 nm and a zeta potential value of 36 ± 1 mV. In contrast, at pH 6.0 only the dispersion with a high amount of chitosan (chitosan:whey protein 1:2) showed good shelf stability up to 20 days. It was possible to produce heat-stable whey protein beverages by regulating the interaction between chitosan and whey protein molecules. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Regioselective Sequential Modification of Chitosan via Azide-Alkyne Click Reaction: Synthesis, Characterization, and Antimicrobial Activity of Chitosan Derivatives and Nanoparticles

    PubMed Central

    Sarwar, Atif; Katas, Haliza; Samsudin, Siti Noradila; Zin, Noraziah Mohamad

    2015-01-01

    Recently, the attention of researchers has been drawn toward the synthesis of chitosan derivatives and their nanoparticles with enhanced antimicrobial activities. In this study, chitosan derivatives with different azides and alkyne groups were synthesized using click chemistry, and these were further transformed into nanoparticles by using the ionotropic gelation method. A series of chitosan derivatives was successfully synthesized by regioselective modification of chitosan via an azide-alkyne click reaction. The amino moieties of chitosan were protected during derivatization by pthaloylation and subsequently unblocked at the end to restore their functionality. Nanoparticles of synthesized derivatives were fabricated by ionic gelation to form complexes of polyanionic penta-sodium tripolyphosphate (TPP) and cationic chitosan derivatives. Particle size analysis showed that nanoparticle size ranged from 181.03 ± 12.73 nm to 236.50 ± 14.32 nm and had narrow polydispersity index and positive surface charge. The derivatives and corresponding nanoparticles were evaluated in vitro for antibacterial and antifungal activities against three gram-positive and gram-negative bacteria and three fungal strains, respectively. The minimum inhibitory concentration (MIC) of all derivatives ranged from 31.3 to 250 µg/mL for bacteria and 188 to1500 µg/mL for fungi and was lower than that of native chitosan. The nanoparticles with MIC ranging from 1.56 to 25 µg/mLfor bacteria and 94 to 750 µg/mL for fungi exhibited higher activity than the chitosan derivatives. Chitosan O-(1-methylbenzene) triazolyl carbamate and chitosan O-(1-methyl phenyl sulfide) triazolyl carbamate were the most active against the tested bacterial and fungal strains. The hemolytic assay on erythrocytes and cell viability test on two different cell lines (Chinese hamster lung fibroblast cells V79 and Human hepatic cell line WRL68) demonstrated the safety; suggesting that these derivatives could be used in future

  9. Regioselective Sequential Modification of Chitosan via Azide-Alkyne Click Reaction: Synthesis, Characterization, and Antimicrobial Activity of Chitosan Derivatives and Nanoparticles.

    PubMed

    Sarwar, Atif; Katas, Haliza; Samsudin, Siti Noradila; Zin, Noraziah Mohamad

    2015-01-01

    Recently, the attention of researchers has been drawn toward the synthesis of chitosan derivatives and their nanoparticles with enhanced antimicrobial activities. In this study, chitosan derivatives with different azides and alkyne groups were synthesized using click chemistry, and these were further transformed into nanoparticles by using the ionotropic gelation method. A series of chitosan derivatives was successfully synthesized by regioselective modification of chitosan via an azide-alkyne click reaction. The amino moieties of chitosan were protected during derivatization by pthaloylation and subsequently unblocked at the end to restore their functionality. Nanoparticles of synthesized derivatives were fabricated by ionic gelation to form complexes of polyanionic penta-sodium tripolyphosphate (TPP) and cationic chitosan derivatives. Particle size analysis showed that nanoparticle size ranged from 181.03 ± 12.73 nm to 236.50 ± 14.32 nm and had narrow polydispersity index and positive surface charge. The derivatives and corresponding nanoparticles were evaluated in vitro for antibacterial and antifungal activities against three gram-positive and gram-negative bacteria and three fungal strains, respectively. The minimum inhibitory concentration (MIC) of all derivatives ranged from 31.3 to 250 µg/mL for bacteria and 188 to1500 µg/mL for fungi and was lower than that of native chitosan. The nanoparticles with MIC ranging from 1.56 to 25 µg/mLfor bacteria and 94 to 750 µg/mL for fungi exhibited higher activity than the chitosan derivatives. Chitosan O-(1-methylbenzene) triazolyl carbamate and chitosan O-(1-methyl phenyl sulfide) triazolyl carbamate were the most active against the tested bacterial and fungal strains. The hemolytic assay on erythrocytes and cell viability test on two different cell lines (Chinese hamster lung fibroblast cells V79 and Human hepatic cell line WRL68) demonstrated the safety; suggesting that these derivatives could be used in future

  10. Influence of molecular weight and pH on adsorption of chitosan at the surface of large and giant vesicles.

    PubMed

    Quemeneur, Francois; Rinaudo, Marguerite; Pépin-Donat, Brigitte

    2008-01-01

    This paper describes the mechanisms of adsorption of chitosan, a positively charged polyelectrolyte, on the DOPC lipid membrane of large and giant unilamellar vesicles (respectively, LUVs and GUVs). We observe that the variation of the zeta potential of LUVs as a function of chitosan concentration is independent on the chitosan molecular weight (Mw). This result is interpreted in terms of electrostatic interactions, which induce a flat adsorption of the chitosan on the surface of the membrane. The role of electrostatic interactions is further studied by observing the variation of the zeta potential as a function of the chitosan concentration for two different charge densities tuned by the pH. Results show a stronger chitosan-membrane affinity at pH 6 (lipids are negatively charged, and 40% chitosan amino groups are protonated) than at pH 3.4 (100% of protonated amino groups but zwitterionic lipids are positively charged) which confirms that adsorption is of electrostatic origin. Then, we investigate the stability of decorated LUVs and GUVs in a large range of pH (6.0 < pH < 12.0) in order to complete a previous study made in acidic conditions [Quemeneur et al. Biomacromolecules 2007, 8, 2512-2519]. A comparative study of the variation of the zeta potential as a function of the pH (2.0 < pH < 12.0) reveals a difference in behavior between naked and chitosan-decorated LUVs. This result is further confirmed by a comparative observation by optical microscopy of naked and chitosan-decorated GUVs in basic conditions (6.0 < pH < 12.0): at pH > 10.0, in the absence of chitosan, the vesicles present complex shapes, contrary to the chitosan-decorated vesicles which remain spherical, confirming thus that chitosan remains adsorbed on vesicles in basic conditions up to pH = 12.0. These results, in addition with our previous data, show that the chitosan-decorated vesicles are stable over a very broad range of pH (2.0 < pH < 12.0), which holds promise for their in vivo

  11. Development of phosphorylated glucomannan-coated chitosan nanoparticles as nanocarriers for protein delivery.

    PubMed

    Cuña, M; Alonso-Sandel, M; Remuñán-López, C; Pivel, J P; Alonso-Lebrero, J L; Alonso, M J

    2006-01-01

    The aim of the present work was to develop a new nanoparticle carrier, adapted for the oral administration of proteins and their delivery to the immune system. Chitosan and phosphorylated glucomannan were chosen as major constituents of the nanoparticles. Chitosan nanoparticles were formed by ionic gelation and then coated with glucomannan. Two different protocols were adopted for the formation of the glucomannan coating: protocol I, in which chitosan nanoparticles were isolated before their coating; protocol II, in which chitosan nanoparticles were not isolated, but coated with glucomannan in the presence of free chitosan. The results showed that, under the selected formulation conditions, the sizes of the nanoparticles ranged between 170 and 300 nm and their zeta potential values were inverted from positive to negative by the glucomannan coating. The nanoparticles prepared by the two protocols could be freeze-dried, in the presence or absence of cryoprotective agents, preserving their original characteristics. The results of the stability study evidenced the positive role of the glucomannan coating in preventing the aggregation of the nanoparticles in buffered media. Finally, the association of the inmunomodulatory protein complex P1 to the chitosan-glucomannan nanoparticles was investigated. The results showed that the association was not dependent on the chitosan: sodium tripoliphosphate ratio, but it was significantly affected by the presence of sodium phosphate in the protein structure.

  12. Synthesis, Characterization, and Antibacterial Activity of Cross-Linked Chitosan-Glutaraldehyde

    PubMed Central

    Li, Bin; Shan, Chang-Lin; Zhou, Qing; Fang, Yuan; Wang, Yang-Li; Xu, Fei; Han, Li-Rong; Ibrahim, Muhammad; Guo, Long-Biao; Xie, Guan-Lin; Sun, Guo-Chang

    2013-01-01

    This present study deals with synthesis, characterization and antibacterial activity of cross-linked chitosan-glutaraldehyde. Results from this study indicated that cross-linked chitosan-glutaraldehyde markedly inhibited the growth of antibiotic-resistant Burkholderia cepacia complex regardless of bacterial species and incubation time while bacterial growth was unaffected by solid chitosan. Furthermore, high temperature treated cross-linked chitosan-glutaraldehyde showed strong antibacterial activity against the selected strain 0901 although the inhibitory effects varied with different temperatures. In addition, physical-chemical and structural characterization revealed that the cross-linking of chitosan with glutaraldehyde resulted in a rougher surface morphology, a characteristic Fourier transform infrared (FTIR) band at 1559 cm−1, a specific X-ray diffraction peak centered at 2θ = 15°, a lower contents of carbon, hydrogen and nitrogen, and a higher stability of glucose units compared to chitosan based on scanning electron microscopic observation, FTIR spectra, X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that cross-linked chitosan-glutaraldehyde is promising to be developed as a new antibacterial drug. PMID:23670533

  13. Effects of chitosan and oligochitosan on development and mitochondrial function of Rhizopus stolonifer.

    PubMed

    Robles-Martínez, Leobarda; Guerra-Sánchez, María Guadalupe; Hernández-Lauzardo, Ana Niurka; Pardo, Juan Pablo; Velázquez-del Valle, Miguel Gerardo

    2014-07-01

    The antifungal activities of chitosan and oligochitosan have been used to control postharvest decay of the fruits. The effect of chitosan and oligochitosan on mycelium growth, spore germination, and mitochondrial function of Rhizopus stolonifer was evaluated in order to establish a connection between fungus development and the main organelle in charge to provide energy to the cell. The mycelium growth of R. stolonifer was significantly reduced on minimum media amended with chitosan or oligochitosan. The highest antifungal indexes were obtained on media containing chitosan or oligochitosan at 2.0 mg ml(-1). Microscopic observation showed that chitosan and oligochitosan affected the spore germination and hyphae morphology. Both polymers increased oxygen consumption of R. stolonifer. Respiratory activity was restored with NADH in permeabilized treated and untreated cells, and was inhibited with rotenone and flavones. Complex III and IV were inhibited by antimycin A and cyanide, respectively, in treated and untreated cells. Chitosan and oligochitosan increased NADH dehydrogenase activity in isolated mitochondria. However, there were not changes in the cytochrome c oxidase and ATPase activities by effect of these polymers. These results suggest that both chitosan and oligochitosan affect the development of R. stolonifer and might be implicated in the mitochondrial dysfunction.

  14. Chitosan as a Modifying Component of Artificial Scaffold for Human Skin Tissue Engineering.

    PubMed

    Romanova, O A; Grigor'ev, T E; Goncharov, M E; Rudyak, S G; Solov'yova, E V; Krasheninnikov, S T; Saprykin, V P; Sytina, E V; Chvalun, S N; Pal'tsev, M A; Panteleev, A A

    2015-08-01

    We compared the structure and mechanical properties of scaffolds based on pure collagen, pure chitosan, and a mixture of these polymers. The role of the composition and structure of scaffolds in the maintenance of cell functions (proliferation, differentiation, and migration) was demonstrated in two experimental models: homogeneous tissue analogues (scaffold populated by fibroblasts) and complex skin equivalents (fibroblasts and keratinocytes). In contrast to collagen scaffolds, pure chitosan inhibited the growth of fibroblasts that did not form contacts with chitosan fibers, but formed specific cellular conglomerates, spheroids, and lose their ability to synthesize natural extracellular matrix. However, the use of chitosan as an additive stimulated proliferative activity of fibroblasts on collagen, which can be associated with improvement of mechanical properties of the collagen scaffolds. The effectiveness of chitosan as an additional cross-linking agent also manifested in its ability to improve significantly the resistance of collagen scaffolds to fibroblast contraction in comparison with glutaraldehyde treatment. Polymer scaffolds (without cells) accelerated complete healing of skin wounds in vivo irrespective of their composition healing, pure chitosan sponge being most effective. We concluded that the use of chitosan as the scaffold for skin equivalents populated with skin cells is impractical, whereas it can be an effective modifier of polymer scaffolds.

  15. Synthesis, characterization, and antibacterial activity of cross-linked chitosan-glutaraldehyde.

    PubMed

    Li, Bin; Shan, Chang-Lin; Zhou, Qing; Fang, Yuan; Wang, Yang-Li; Xu, Fei; Han, Li-Rong; Ibrahim, Muhammad; Guo, Long-Biao; Xie, Guan-Lin; Sun, Guo-Chang

    2013-05-13

    This present study deals with synthesis, characterization and antibacterial activity of cross-linked chitosan-glutaraldehyde. Results from this study indicated that cross-linked chitosan-glutaraldehyde markedly inhibited the growth of antibiotic-resistant Burkholderia cepacia complex regardless of bacterial species and incubation time while bacterial growth was unaffected by solid chitosan. Furthermore, high temperature treated cross-linked chitosan-glutaraldehyde showed strong antibacterial activity against the selected strain 0901 although the inhibitory effects varied with different temperatures. In addition, physical-chemical and structural characterization revealed that the cross-linking of chitosan with glutaraldehyde resulted in a rougher surface morphology, a characteristic Fourier transform infrared (FTIR) band at 1559 cm⁻¹, a specific X-ray diffraction peak centered at 2θ = 15°, a lower contents of carbon, hydrogen and nitrogen, and a higher stability of glucose units compared to chitosan based on scanning electron microscopic observation, FTIR spectra, X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that cross-linked chitosan-glutaraldehyde is promising to be developed as a new antibacterial drug.

  16. The coagulation characteristics of humic acid by using acid-soluble chitosan, water-soluble chitosan, and chitosan coagulant mixtures.

    PubMed

    Chen, Chih-Yu; Wu, Chung-Yu; Chung, Ying-Chien

    2015-01-01

    Chitosan is a potential substitute for traditional aluminium salts in water treatment systems. This study compared the characteristics of humic acid (HA) removal by using acid-soluble chitosan, water-soluble chitosan, and coagulant mixtures of chitosan with aluminium sulphate (alum) or polyaluminium chloride (PACl). In addition, we evaluated their respective coagulation efficiencies at various coagulant concentrations, pH values, turbidities, and hardness levels. Furthermore, we determined the size and settling velocity of flocs formed by these coagulants to identify the major factors affecting HA coagulation. The coagulation efficiency of acid- and water-soluble chitosan for 15 mg/l of HA was 74.4% and 87.5%, respectively. The optimal coagulation range of water-soluble chitosan (9-20 mg/l) was broader than that of acid-soluble chitosan (4-8 mg/l). Notably, acid-soluble chitosan/PACl and water-soluble chitosan/alum coagulant mixtures exhibited a higher coagulation efficiency for HA than for PACl or alum alone. Furthermore, these coagulant mixtures yielded an acceptable floc settling velocity and savings in both installation and operational expenses. Based on these results, we confidently assert that coagulant mixtures with a 1:1 mass ratio of acid-soluble chitosan/PACl and water-soluble chitosan/alum provide a substantially more cost-effective alternative to using chitosan alone for removing HA from water.

  17. Comperative study of catalase immobilization on chitosan, magnetic chitosan and chitosan-clay composite beads.

    PubMed

    Başak, Esra; Aydemir, Tülin; Dinçer, Ayşe; Becerik, Seda Çınar

    2013-12-01

    Catalase was immobilized on chitosan and modified chitosan. Studies were carried out on free-immobilized catalase concerning the determination of optimum temperature, pH, thermal, storage stability, reusability, and kinetic parameters. Optimum temperature and pH for free catalase and catalase immobilized were found as 35°C and 7.0, respectively. After 100 times of repeated tests, the immobilized catalases on chitosan-clay and magnetic chitosan maintain over 50% and 60% of the original activity, respectively. The ease of catalase immobilization on low-cost matrices and good stability upon immobilization in the present study make it a suitable product for further use in the food industry.

  18. Synthesis, self-assembly, and cytotoxicity of well-defined trimethylated chitosan-O-poly(ε-caprolactone): effect of chitosan molecular weight.

    PubMed

    Zhang, Haiwen; Cai, Guoqiang; Tang, Guping; Wang, Liqun; Jiang, Hongliang

    2011-08-01

    Structurally well-defined trimethylated chitosan-O-poly(ε-caprolactone) (TMC-O-PCL) was synthesized under mild homogeneous conditions, using sodium dodecyl sulfate-dimethylated chitosan complex (SDC) as an organosoluble intermediate. The effect of chitosan molecular weight (MW) on the preparation, organosolubility, self-assembly, and cytotoxicity of the copolymers was investigated. The copolymers with low-MW chitosan backbone had improved solubility in common organic solvents. Spherical micelles with average diameter of 25-55 nm and uniform morphology were formed through self-assembly of TMC-O-PCL in pH 7.4 PBS. When trimethylation degree of the copolymers was above 44%, the micelles could remain stable in neutral aqueous media. The critical aggregation concentration of TMC-O-PCL slightly increased with a decrease in the MW of chitosan backbone. The cytotoxicity of the cationic micelles could be suppressed by increasing PCL grafting levels, reducing trimethylation degree, and MW of the chitosan backbone. Copyright © 2011 Wiley Periodicals, Inc.

  19. Influence of unmodified and β-glycerophosphate cross-linked chitosan on anti-Candida activity of clotrimazole in semi-solid delivery systems.

    PubMed

    Szymańska, Emilia; Winnicka, Katarzyna; Wieczorek, Piotr; Sacha, Paweł Tomasz; Tryniszewska, Elżbieta Anna

    2014-09-30

    The combination of an antifungal agent and drug carrier with adjunctive antimicrobial properties represents novel strategy of complex therapy in pharmaceutical technology. The goal of this study was to investigate the unmodified and ion cross-linked chitosan's influence on anti-Candida activity of clotrimazole used as a model drug in hydrogels. It was particularly crucial to explore whether the chitosans' structure modification by β-glycerophosphate altered its antifungal properties. Antifungal studies (performed by plate diffusion method according to CLSI reference protocol) revealed that hydrogels obtained with chitosan/β-glycerophosphate displayed lower anti-Candida effect, probably as a result of weakened polycationic properties of chitosan in the presence of ion cross-linker. Designed chitosan hydrogels with clotrimazole were found to be more efficient against tested Candida strains and showed more favorable drug release profile compared to commercially available product. These observations indicate that novel chitosan formulations may be considered as promising semi-solid delivery system of clotrimazole.

  20. FT-IR studies on interactions among components in hexanoyl chitosan-based polymer electrolytes.

    PubMed

    Winie, Tan; Arof, A K

    2006-03-01

    Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF(3)SO(3))-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF(3)SO(3) interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR)(2), CONHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF(3)SO(3) has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li(+) ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.

  1. Preparation and immunological effectiveness of a swine influenza DNA vaccine encapsulated in chitosan nanoparticles.

    PubMed

    Zhao, Kai; Shi, Xingming; Zhao, Yan; Wei, Haixia; Sun, Qingshen; Huang, Tingting; Zhang, Xiaoyan; Wang, Yunfeng

    2011-11-03

    Preparation conditions of a DNA vaccine against swine influenza encapsulated in chitosan nanoparticles were determined. The nanoparticles were prepared according to a complex coacervation method using chitosan as a biodegradable matrix forming polymer. Under the preparation conditions, chitosan nanoparticles containing the DNA vaccine were produced with good morphology, high encapsulation rate and high stability. Transfection test indicated that the vaccine could be expressed as an antigen in cells, and maintained good bioactivity. In addition, better immune responses of mice immunized with the chitosan nanoparticles containing the DNA vaccine were induced and prolonged release of the plasmid DNA was achieved compared to the DNA vaccine alone. These results laid a foundation for further development of DNA vaccines in nanoparticles before ultimate industrial application.

  2. PEC films prepared from Chitosan-Alginate coacervates.

    PubMed

    Yan, X; Khor, E; Lim, L Y

    2000-07-01

    Chitosan-alginate polyelectrolyte complex (PEC) have been prepared in situ in beads and microspheres. This study examines the preparation of suitable chitosan-alginate coacervates for casting into homogeneous PEC films for potential applications in packaging, controlled release systems and wound dressings. Coacervation between chitosan and alginate was rapid, but the rate may be controlled with the addition of water miscible organic solvents. Compared with ethanol and PEG200, acetone was the more promising solvent moderator. Suspensions of fine, uniformly dispersed coacervates were produced by a dropwise addition of 0.25% w/v chitosan solution (solvent: 1: 1 v/v of 2% acetic acid and acetone) into 0.25% w/v sodium alginate solution in water under rapid agitation. The PEC films were transparent and flexible. They exhibited high permeability to water vapor, but resisted complete dissolution in 0.1 M HCI, distilled water and pH 7.4 phosphate buffer solution. Microscopic heterogeneity in the films could be reduced by immersion in aqueous media, but this was accompanied by modifications in the thickness, permeability and mechanical property of the films.

  3. Design of controlled-release solid dosage forms of alginate and chitosan using microwave.

    PubMed

    Wong, Tin Wui; Chan, Lai Wah; Kho, Shyan Bin; Sia Heng, Paul Wan

    2002-12-05

    The influence of microwave irradiation on the drug release properties of alginate, alginate-chitosan and chitosan beads was investigated. The beads were prepared with the highest possible concentration of polymer by an extrusion method. Sulphathiazole was selected as a model drug. The beads were subjected to microwave irradiation at various combinations of irradiation power and time. The profiles of drug dissolution, drug content, drug stability, drug polymorphism, drug-polymer interaction, polymer crosslinkage and complexation were determined by dissolution testing, drug content assay, differential scanning calorimetry (DSC) and fourier transform infra-red spectroscopy (FTIR). The chemical stability of the drug entrapped in the beads was unaffected by the microwave irradiation. However, the drug in the chitosan beads underwent polymorphic changes. Polymorphic changes were prevented by means of drug-alginate interaction in alginate and alginate-chitosan beads. Changes in the polymorphic state of drug were found to have insignificant effect on the drug release profiles of chitosan beads. The release-retarding property of alginate and alginate-chitosan beads was significantly enhanced by subjecting the beads to microwave irradiation. Positively charged calcium ions and chitosan are known to interact with negatively charged alginate. DSC and FTIR analyses indicated that the reduction in rate and extent of drug released from the treated beads was primarily due to additional formation of non-ionic bonds, involving alginate crosslinkage and alginate-chitosan complexation. The results showed that microwave technology can be employed in the design of solid dosage forms for controlled-release application without the use of noxious chemical agents. Copyright 2002 Elsevier Science B.V.

  4. Spinning of hydroalcoholic chitosan solutions.

    PubMed

    Desorme, Mylène; Montembault, Alexandra; Lucas, Jean-Michel; Rochas, Cyrille; Bouet, Thierry; David, Laurent

    2013-10-15

    We investigated the spinning of hydroalcoholic chitosan solutions. The dope composition was optimized in order to obtain a continuous alcogel fiber by water evaporation on heating the extruded hydroalcoholic solution. This alcogel fiber was then neutralized in aqueous alkali baths and washed in water to eliminate the residual alcohol and salts before final drying. Depending on the alcohol content in the filament at the neutralization step, on specific alcohol-chitosan interactions and on the nature and concentration of the coagulation base, the process yielded semicrystalline chitosan fibers with different proportions of anhydrous and hydrated allomorphs. Contrarily to the classical annealing method, the formation of mainly anhydrous crystals was obtained without significant molecular weight decrease by neutralizing the polymer in hydrophobic conditions. The control of allomorph content was shown to be related to the hydrophobicity of the solvent (alcohol fraction) at the neutralization step. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Effect of Chitosan on Membrane Permeability of Suspension-Cultured Glycine max and Phaseolus vulgaris Cells 1

    PubMed Central

    Young, David H.; Köhle, Harald; Kauss, Heinrich

    1982-01-01

    Treatment of suspension-cultured Glycine max cv Harosoy 63 cells with soluble chitosan (20-500 micrograms per milliliter) increased membrane permeability as shown by leakage of electrolytes, protein, and UV absorbing material. Severe damage to the cell membrane by chitosan (100 and 500 μg/ml) was also indicated by reduced staining with fluorescein diacetate and the leakage of fluorescein from preloaded cells. Other basic polymers (poly-l-lysine, histone, DEAE-dextran, protamine sulfate, and glycol chitosan) also increased permeability, whereas the basic monomers l-lysine and d-glucosamine, and acidic or neutral polymers were not active. Chitosan-induced leakage was inhibited by divalent cations, the order of effectiveness being Ba2+ > Ca2+ > Sr2+ > Mg2+. Na polygalacturonate and Na poly-l-aspartate also reduced polycation-induced leakage, probably by formation of polycation-polyanion complexes. A chitosan-polygalacturonate complex precipitated on mixing solutions of the two polymers containing approximately equal numbers of galacturonate and glucosamine residues, but not with either polymer in excess. A similar concentration-dependent precipitation of chitosan by Na poly-l-aspartate was found. Leakage from Phaseolus vulgaris cv Grandessa cells was also induced by chitosan, and was inhibited by Ca2+ and Na polygalacturonate. PMID:16662696

  6. Chitosan-based hydrogels for developing a small-diameter vascular graft: in vitro and in vivo evaluation.

    PubMed

    Aussel, Audrey; Thébaud, Noélie; Berard, Xavier; Brizzi, Vincenzo; Delmond, Samantha; Bareille, Reine; Siadous, Robin; James, Chloe; Ripoche, Jean; Durand, Marlène; Montembault, Alexandra; Burdin, Béatrice; Letourneur, Didier; L'Heureux, Nicolas; David, Laurent; Bordenave, Laurence

    2017-06-12

    Vascular grafts made of synthetic polymers perform poorly in small-diameter applications (cardiac and peripheral bypass). Chitosan is a biocompatible natural polymer that can provide a novel biological scaffold for tissue engineering development. The goal of this study was to demonstrate the biocompatibility of a novel chitosan preparation in vitro and in vivo, and to assess its potential as a scaffold for vascular applications. Methods and Results. A series of experiments of increasing complexity, ranging from in vitro biocompatibility and hemocompatibility tests to in vivo studies in small and large animals (rat and sheep), was performed to provide a comprehensive analysis of chitosan hydrogels' biological properties. In vitro studies established that: i) chitosan supported human endothelial progenitor cells adhesion, proliferation and resistance to physiological shear stress; ii) chitosan did not activate platelets, the complement system, or the intrinsic coagulation pathway. In vivo results showed: iii) no resorption of chitosan and no chronic inflammation at 60 days in a rat heterotopic implantation model (magnetic resonance imaging and histology); iv) no flow obstruction (Doppler ultrasound) and no thrombus formation (histology and scanning electron microscopy) at 2 hours after a carotid arteriotomy repair with chitosan patches in sheep. Finally, 2 chitosan tubes were implanted as carotid interposition grafts for 3 days in sheep showing that chitosan was strong enough to be sutured, to withstand arterial pressure, and no flow obstruction was observed through this short period. Conclusion. Chitosan-based hydrogels displayed promising in vitro biocompatibility and hemocompatibility properties as well as in vivo short-term performance. . © 2017 IOP Publishing Ltd.

  7. Antimicrobial activity of hydroxylbenzenesulfonailides derivatives of chitosan, chitosan sulfates and carboxymethyl chitosan.

    PubMed

    Zhong, Zhimei; Li, Pengcheng; Xing, Ronge; Liu, Song

    2009-08-01

    Chitosan, carboxymethyl chitosan (CMCS) and chitosan sulfates (CSS) with different molecular weight were modified by reacting with 4-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride or 2-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride to give 12 kinds of new hydroxylbenzenesulfonailides derivatives of them. The preparation conditions of the derivatives were discussed in this paper, and their structures were characterized by FT-IR and 13C NMR spectroscopy. The solubility of the derivatives was measured in the experiment. In addition, their antimicrobial activities against four bacteria and five crop-threatening pathogenic fungi were tested in the experiment. Besides, the rule and mechanism of their antibacterial activities were discussed in this paper.

  8. Use of chitosan-alginate as alternative pelletization aid to microcrystalline cellulose in extrusion/spheronization.

    PubMed

    Charoenthai, Nattawut; Kleinebudde, Peter; Puttipipatkhachorn, Satit

    2007-09-01

    Two types of different molecular weight chitosan were investigated as a pelletization aid in extrusion/spheronization using water as granulation liquid. Spherical pellets with a maximum fraction of 60% w/w chitosan could be produced when 1.25-2.5% w/w sodium alginate was included in the formulations with no microcrystalline cellulose (MCC). Chitosan with lower molecular weight of 190 kDa showed a better pellet forming property. The pellets obtained had acceptable physical characteristics and a fast drug release. The results from Fourier transform infrared spectroscopy, differential scanning calorimetry and (13)C CP-MAS nuclear magnetic resonance spectroscopy confirmed the formation of polyelectrolyte complex (PEC) between chitosan and sodium alginate, which might be a reason for successful pelletization by extrusion/spheronization. Moreover, the presence of PEC might influence the physical characteristics and dissolution behavior of chitosan-alginate pellets. The results indicated an achievement in production of pellets by extrusion/spheronization without using MCC. Moreover, chitosan combined with sodium alginate could be used as a promising alternative pelletization aid to MCC in extrusion/spheronization. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

  9. Fine-tuned PEGylation of chitosan to maintain optimal siRNA-nanoplex bioactivity.

    PubMed

    Guţoaia, Andra; Schuster, Liane; Margutti, Simona; Laufer, Stefan; Schlosshauer, Burkhard; Krastev, Rumen; Stoll, Dieter; Hartmann, Hanna

    2016-06-05

    Polyethylene glycol (PEG) is a widely used modification for drug delivery systems. It reduces undesired interaction with biological components, aggregation of complexes and serves as a hydrophilic linker of ligands for targeted drug delivery. However, PEGylation can also lead to undesired changes in physicochemical characteristics of chitosan/siRNA nanoplexes and hamper gene silencing. To address this conflicting issue, PEG-chitosan copolymers were synthesized with stepwise increasing degrees of PEG substitution (1.5% to 8.0%). Subsequently formed PEG-chitosan/siRNA nanoplexes were characterized physicochemically and biologically. The results showed that small ratios of chitosan PEGylation did not affect nanoplex stability and density. However, higher PEGylation ratios reduced nanoplex size and charge, as well as cell uptake and final siRNA knockdown efficiency. Therefore, we recommend fine-tuning of PEGylation ratios to generate PEG-chitosan/siRNA delivery systems with maximum bioactivity. The degree of PEGylation for chitosan/siRNA nanoplexes should be kept low in order to maintain optimal nanoplex efficiency.

  10. Peptide-modified chitosan hydrogels promote skin wound healing by enhancing wound angiogenesis and inhibiting inflammation

    PubMed Central

    Chen, Xionglin; Zhang, Min; Wang, Xueer; Chen, Yinghua; Yan, Yuan; Zhang, Lu; Zhang, Lin

    2017-01-01

    Cutaneous wound healing following trauma is a complex and dynamic process involving multiple overlapping events following trauma. Two critical elements affecting skin wound healing are neovascularization and inflammation. A nascent vessel can provide nutrition and oxygen to a healing wound. Therefore, treatments strategies that enhance angiogenesis and inhibit inflammation can promote skin wound healing. Previous studies have shown that the SIKVAV peptide (Ser-Ile-Lys-Val-Ala-Val) from laminin can promote angiogenesis in vitro. This study evaluated the effects of peptide SIKVAV-modified chitosan hydrogels on skin wound healing. We established skin wounds established in mice and treated them with SIKVAV-modified chitosan hydrogels. H&E staining showed that peptide-modified chitosan hydrogels accelerated the reepithelialization of wounds compared with the negative and positive controls. Immunohistochemistry analysis demonstrated that more myofibroblasts were deposited at wounds treated with peptide-modified chitosan hydrogels that at those treated with negative and positive controls. In addition, peptide-modified chitosan hydrogels promoted angiogenesis as well as keratinocyte proliferation and differentiation, but inhibited inflammation in skin wounds. Taken together, these results suggest that SIKVAV-modified chitosan hydrogels are a promising treatment component for healing-impaired wounds. PMID:28559985

  11. Chitosan-lignosulfonates sono-chemically prepared nanoparticles: characterisation and potential applications.

    PubMed

    Kim, Suyeon; Fernandes, Margarida M; Matamá, Teresa; Loureiro, Ana; Gomes, Andreia C; Cavaco-Paulo, Artur

    2013-03-01

    Due to their recognised properties of biocompatibility, biodegradability and sustainability, chitosan nanocarriers have been successfully used as new delivery systems. In this work, nanoparticles combining chitosan and lignosulfonates were developed for the first time for cosmetic and biomedical applications. The ability of lignosulfonates to act as a counter polyion for stabilisation of chitosan particles, generated using high intensity ultrasound, was investigated. Several conditions for particles preparation were tested and optimised and the resulting nanoparticles were comprehensively characterised by measuring particle size, zeta potential and polydispersity index. The pH of chitosan solution, sonication time and the presence of an adequate surfactant, poloxamer 407, were determinant factors on the development of smaller particles with low polydispersity index (an average particle size of 230 nm was obtained at pH 5 after 8 min of sonication). The beneficial effects of lignosulfonates complex on chitosan nanoparticles were further characterised. Greater stability to lysozyme degradation, biocompatibility with human cells and antimicrobial activity was found upon lignosulfonates incorporation into chitosan nanoparticles. Furthermore, these particles were able to incorporate a hydrophilic model protein - RNase A. A burst release was observed when nanoparticles were loaded with low amount of protein while with high protein content, a sustained release was found, suggesting that the protein cargo maybe loaded both at the surface as in the bulk of the particle, depending on the concentration of drug incorporated.

  12. Effect of radiation-degraded chitosan on plants stressed with vanadium

    NASA Astrophysics Data System (ADS)

    Xuan Tham, Le; Nagasawa, Naotsugu; Matsuhashi, Shinpei; Ishioka, Noriko S.; Ito, Takehito; Kume, Tamikazu

    2001-05-01

    The toxicity of vanadium (V) and the effect of chitosan has been investigated on soybean, rice, wheat and barley. Wheat and barley were sensitive to V than rice and soybean but all seedlings of these plants were damaged at 2.5 μg/ml V (in VCl 3). These damages were reduced by application of radiation-degraded chitosan. The recovery of growth and reduction of V levels in seedlings were obtained by the treatments with 10-100 μg/ml chitosan irradiated at 70-200 kGy of γ-rays in 1% solution. The reductions of V and Fe contents in plants were due to the ability of chitosan to form chelate complexes with metals in solution. The result of BAS analysis shows that the absorption and transportation of 48V to the leaf from root was suppressed with irradiated chitosan. Therefore, it can be concluded that chitosan irradiated at suitable doses (ca. 100 kGy) is effective as plant growth promoters and heavy metal eliminators in crop production.

  13. Structural investigation of chitosan-based microspheres with some anti-inflammatory drugs

    NASA Astrophysics Data System (ADS)

    Dreve, Simina; Kacso, Iren; Popa, Adriana; Raita, Oana; Dragan, Felicia; Bende, A.; Borodi, Gh.; Bratu, I.

    2011-06-01

    The use of chitosan as an excipient in oral formulations, as a drug delivery vehicle for ulcerogenic anti-inflammatory drugs and as base in polyelectrolyte complex systems, to prepare solid release systems as sponges was investigated. The preparation by double emulsification of chitosan hydrogels carrying diclofenac, acetyl-salycilic acid and hydrocortisone acetate as anti-inflammatory drugs is reported. The concentration of anti-inflammatory drug in the chitosan hydrogel generating the sponges was 0.08 mmol. Chitosan-drug loaded sponges with anti-inflammatory drugs were prepared by freeze-drying at -60 °C and 0.009 atm. Structural investigations of the solid formulations were done by Fourier-transformed infrared and ultraviolet-visible spectroscopy, spectrofluorimetry, differential scanning calorimetry and X-ray diffractometry. The results indicated that the drug molecules are forming temporary chelates in chitosan hydrogels and sponges. Electron paramagnetic resonance demonstrates the presence of free radicals in a wide range and the antioxidant activity for chitosan-drug supramolecular cross-linked assemblies.

  14. Formation of calcium carbonate films on chitosan substrates in the presence of polyacrylic acid

    SciTech Connect

    He, Linghao; Xue, Rui; Song, Rui

    2009-05-15

    In this investigation, chitosan membranes with different surface average degrees of deacetylation (DA) are prepared and then are employed as the support matrix to culture calcium carbonate (CaCO{sub 3}). In the presence of high concentration of polyacrylic acid (PAA), the CaCO{sub 3} films obtained on the surface of all chitosan films mainly consisted of vaterite, which suggests the presence of bulk PAA plays an overwhelming part in stabilizing the vaterite. As a comparison, the influences of active groups indicate that only in case of low concentration PAA the thin CaCO{sub 3} films grown on chitosan with 8% DA mainly consisted of vaterite owing to the strong nucleation ability of -NH{sub 2} group, whereas, for those grown on chitosan with 80% DA the CaCO{sub 3} films mainly consisted of aragonite. A more complex scenario revealed that in the case of intermediate concentration of PAA the formed polymorphs behave as mixtures of vaterite and aragonite. - Graphical abstract: Chitosan membranes with different degrees of deacetylation (DA) are employed as support to culture calcium carbonate (CaCO{sub 3}). In high concentration of polyacrylic acid (PAA), the CaCO{sub 3} films obtained consisted of vaterite. However, the CaCO{sub 3} film grown on chitosan with 8% DA mainly consisted of vaterite as opposed to aragonite for chitosan with 8% DA. The schematic presentation of the formation of calcium carbonate on chitosan films with different degrees of acetylation in the presence of PAA with low-, mid- and high concentrations.

  15. Antimicrobial and anticancer activities of porous chitosan-alginate biosynthesized silver nanoparticles.

    PubMed

    Venkatesan, Jayachandran; Lee, Jin-Young; Kang, Dong Seop; Anil, Sukumaran; Kim, Se-Kwon; Shim, Min Suk; Kim, Dong Gyu

    2017-05-01

    The main aim of this study was to obtain porous antimicrobial composites consisting of chitosan, alginate, and biosynthesized silver nanoparticles (AgNPs). Chitosan and alginate were used owing to their pore-forming capacity, while AgNPs were used for their antimicrobial property. The developed porous composites of chitosan-alginate-AgNPs were characterized using Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). The FT-IR results revealed the presence of a strong chemical interaction between chitosan and alginate due to polyelectrolyte complex; whereas, the XRD results confirmed the presence of AgNPs in the composites. The dispersion of AgNPs in the porous membrane was uniform with a pore size of 50-500μm. Antimicrobial activity of the composites was checked with Escherichia coli and Staphylococcus aureus. The developed composites resulted in the formation of a zone of inhibition of 11±1mm for the Escherichia coli, and 10±1mm for Staphylococcus aureus. The bacterial filtration efficiency of chitosan-alginate-AgNPs was 1.5-times higher than that of the chitosan-alginate composite. The breast cancer cell line MDA-MB-231 was used to test the anticancer activity of the composites. The IC50 value of chitosan-alginate-AgNPs on MDA-MB-231 was 4.6mg. The developed chitosan-alginate-AgNPs composite showed a huge potential for its applications in antimicrobial filtration and cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Pharmacokinetics and biodegradation of chitosan in rats

    NASA Astrophysics Data System (ADS)

    Li, Hui; Jiang, Zhiwen; Han, Baoqin; Niu, Shuyi; Dong, Wen; Liu, Wanshun

    2015-10-01

    Chitosan, an excellent biomedical material, has received a widespread in vivo application. In contrast, its metabolism and distribution once being implanted were less documented. In this study, the pharmacokinetics and biodegradation of fluorescein isothiocyanate (FITC) labeled and muscle implantation administrated chitosan in rats were investigated with fluorescence spectrophotometry, histological assay and gel chromatography. After implantation, chitosan was degraded gradually during its distribution to diverse organs. Among the tested organs, liver and kidney were found to be the first two highest in chitosan content, which was followed by heart, brain and spleen. Urinary excretion was believed to be the major pathway of chitosan elimination, yet 80% of chitosan administered to rats was not trackable in their urine. This indicated that the majority of chitosan was degraded in tissues. In average, the molecular weight of the degradation products of chitosan in diverse organs and urine was found to be <65 kDa. This further confirmed the in vivo degradation of chitosan. Our findings provided new evidences for the intensive and safe application of chitosan as a biomedical material.

  17. Impact of chitosan composites and chitosan nanoparticle composites on various drug delivery systems: A review.

    PubMed

    Elgadir, M Abd; Uddin, Md Salim; Ferdosh, Sahena; Adam, Aishah; Chowdhury, Ahmed Jalal Khan; Sarker, Md Zaidul Islam

    2015-12-01

    Chitosan is a promising biopolymer for drug delivery systems. Because of its beneficial properties, chitosan is widely used in biomedical and pharmaceutical fields. In this review, we summarize the physicochemical and drug delivery properties of chitosan, selected studies on utilization of chitosan and chitosan-based nanoparticle composites in various drug delivery systems, and selected studies on the application of chitosan films in both drug delivery and wound healing. Chitosan is considered the most important polysaccharide for various drug delivery purposes because of its cationic character and primary amino groups, which are responsible for its many properties such as mucoadhesion, controlled drug release, transfection, in situ gelation, and efflux pump inhibitory properties and permeation enhancement. This review can enhance our understanding of drug delivery systems particularly in cases where chitosan drug-loaded nanoparticles are applied. Copyright © 2014. Published by Elsevier B.V.

  18. Mechanistic characterization and inhibition of sphingomyelinase C over substituted Iron Schiff bases of chitosan adsorbed on glassy carbon electrode.

    PubMed

    Caro, Claudia A; Lillo, Luis; Valenzuela, Francisco J; Cabello, Gerardo

    2017-02-01

    The medical treatment of laxoscelisms is based solely on supportive measures. Although equine antiserum for Sphingomyelinase C (SMASE) and D isomers are available, it is not used due to the risk of an anaphylactic reaction and its unproven efficacy. As potential enzyme inhibitors, derivatives of Iron chitosan complexes were studied (Shiff base having -R = -H, -Cl, -Br, -F, -OCH3, -CH3, -NO2). These chitosan complexes were chosen because they have revealed good results in medicine and catalysis due to their biodegradable characteristics and bioavailability. Besides considering that these complexes have not been studied in relation to this toxin. The mechanisms underlying the catalytic and catcher effects of Iron chitosan complexes were studied using electrochemistry, UV-Vis spectroscopy and microscopic assay at physiological pH. The electrochemical studies showed that one of seven Schiff bases of chitosan adsorbed on glassy carbon electrode was electrocatalytically active for the oxidation of sphingomyelinase at 1.27 V, and that allowed proposing a reaction scheme for SMASE oxidation by adsorbed Iron complexes. On the other hand, even though the spectroscopic studies indicated that there was no chemical bond formation between the complex and SMASE in solution, the microscopic studies showed that this complex proved to be a remarkable cellular protector in presence of the enzyme. In conclusion, Shiff base of chitosan with R = -CH3 was the only active complex in front of sphingomyelinase C, protecting red blood cells, according to our electrochemical and microscopic studies.

  19. Adsorption of fucoidan and chitosan sulfate on chitosan modified PET films monitored by QCM-D.

    PubMed

    Indest, Tea; Laine, Janne; Johansson, Leena-Sisko; Stana-Kleinschek, Karin; Strnad, Simona; Dworczak, Renate; Ribitsch, Volker

    2009-03-09

    The adsorption behavior of fucoidan as well as chitosan derivatives (chitosan sulfate) on poly(ethylene terephthalate) (PET) model film surface was studied using the quartz crystal microbalance technique. These systems were chosen for this study due to their promising biocompatible properties. Moreover, fucoidan and chitosan sulfate have promising anticoagulant properties and represent an alternative to heparin treatment of vascular grafts. As a first step, PET foils were activated by alkaline hydrolysis to increase their hydrophilicity. From these foils, model PET films were prepared by the spin coating technique on a silica quartz crystal. The selected polysaccharides (chitosan, fucoidan, and chitosan sulfate) were adsorbed from aqueous solutions on the PET surfaces. The adsorption was monitored using a quartz crystal microbalance with a dissipation unit. The surface chemistry and morphology of the chitosan/fucoidan or chitosan/chitosan sulfate coated PET-H films was analyzed using XPS and AFM. It was found that chitosan/fucoidan films were thinner and more compressed, while in the case of chitosan/chitosan sulfate, large amounts of chitosan sulfate were adsorbed, indicating a loose and thick adsorbed film.

  20. Radiation depolymerization of chitosan to prepare oligomers

    NASA Astrophysics Data System (ADS)

    Hai, Le; Bang Diep, Tran; Nagasawa, Naotsugu; Yoshii, Fumio; Kume, Tamikazu

    2003-08-01

    Radiation depolymerization of chitosan was carried out by gamma irradiation in the solid state. The radiation-chemical depolymerization yield of chitosan in the solid state, Gd, determined by gel permeation chromatography, is 0.9 for chitosan 10B and 1.8 for chitosan 8B. Low molecular weight chitosan/or oligochitosans were separated from a chitosan depolymerized by gamma radiation, using mixtures of methanol-water and acetone as the solvents. Due to the differences in solubility revealed upon radiolysis, extracts became subdivided into precipitates and soluble fractions. The biological effect of oligochitosan in each fraction was evaluated; the preliminary results indicated that the oligochitosan with overlineM w=2×10 4 inhibited the growth of fungi at 100 ppm and that with overlineM w=800 only enhanced the growth of the same typical fungi.

  1. Chitosan Modification and Pharmaceutical/Biomedical Applications

    PubMed Central

    Zhang, Jiali; Xia, Wenshui; Liu, Ping; Cheng, Qinyuan; Tahirou, Talba; Gu, Wenxiu; Li, Bo

    2010-01-01

    Chitosan has received much attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine. Our recent efforts focused on the chemical and biological modification of chitosan in order to increase its solubility in aqueous solutions and absorbability in the in vivo system, thus for a better use of chitosan. This review summarizes chitosan modification and its pharmaceutical/biomedical applications based on our achievements as well as the domestic and overseas developments: (1) enzymatic preparation of low molecular weight chitosans/chitooligosaccharides with their hypocholesterolemic and immuno-modulating effects; (2) the effects of chitin, chitosan and their derivatives on blood hemostasis; and (3) synthesis of a non-toxic ion ligand—D-Glucosaminic acid from Oxidation of D-Glucosamine for cancer and diabetes therapy. PMID:20714418

  2. Vitamin D-fortified chitosan films from mushroom waste.

    PubMed

    Bilbao-Sainz, Cristina; Chiou, Bor-Sen; Williams, Tina; Wood, Delilah; Du, Wen-Xian; Sedej, Ivana; Ban, Zhaojun; Rodov, Victor; Poverenov, Elena; Vinokur, Yakov; McHugh, Tara

    2017-07-01

    Brown mushroom (Agaricus bisporus) stalk bases from mushroom waste were treated with UV-B light to rapidly increase vitamin D2 content. Chitin was also recovered from this waste and converted into chitosan by N-deacetylation. FTIR spectra showed that the mushroom chitosan were similar to chitosan from animal sources. Chitosan films were prepared using high molecular weight (HW), low molecular weight (LW) and fungal chitosan. UV-B treated mushroom particles were also incorporated into fungal chitosan films. The fungal chitosan films showed similar density, porosity and water vapor barrier properties to the LW and HW chitosan films. However, fungal chitosan films were more hydrophobic and less flexible than the LW and HW chitosan films. Addition of mushroom particles did not significantly affect mechanical or water barrier properties of the fungal chitosan films. Published by Elsevier Ltd.

  3. Enhanced arsenic removal using mixed metal oxide impregnated chitosan beads.

    PubMed

    Yamani, Jamila S; Miller, Sarah M; Spaulding, Matthew L; Zimmerman, Julie B

    2012-09-15

    Mixed metal oxide impregnated chitosan beads (MICB) containing nanocrystalline Al₂O₃ and nanocrystalline TiO₂ were successfully developed. This adsorbent exploits the high capacity of Al₂O₃ for arsenate and the photocatalytic activity of TiO₂ to oxidize arsenite to arsenate, resulting in a removal capacity higher than that of either metal oxide alone. The composition of the beads was optimized for maximum arsenite removal in the presence of UV light. The mechanism of removal was investigated and a mode of action was proposed wherein TiO₂ oxidizes arsenite to arsenate which is then removed from solution by Al₂O₃. Pseudo-second order kinetics were used to validate the proposed mechanism. MICB is a more efficient and effective adsorbent for arsenic than TiO₂-impregnated chitosan beads (TICB), previously reported on, yet maintains a desirable life cycle, free of complex synthesis processes, toxic materials, and energy inputs.

  4. Estimating the energy of intramolecular hydrogen bonds in chitosan oligomers

    NASA Astrophysics Data System (ADS)

    Mikhailov, G. P.; Lazarev, V. V.

    2016-07-01

    The effect the number of chitosan monomer units CTS n ( n = 1-5), the protonation of chitosan dimers, and the interaction between CTS n ( n = 1-3) and acetate ions have on the energy of intramolecular hydrogen bonds is investigated by means of QTAIM analysis and solving the vibrational problem within the cluster-continuum model. It is established that the number of H-bonds in CTS n is 2 n - 1 and the total energy of H-bonds grows by ~20 kJ/mol. It is concluded that the hydrogen bonds between CTS and acetate ions play a major role in the stabilization of polyelectrolyte complexes in dilute acetic acid solutions of CTS.

  5. Copper(II)-EDTA sorption onto chitosan and its regeneration applying electrolysis.

    PubMed

    Gyliene, O; Nivinskiene, O; Razmute, I

    2006-10-11

    Cu(II)-EDTA (ethylendiaminetetraacetate) complexes are widely used in the manufacture of printed circuit boards. In order to avoid the outlet into the environment the sorption of complexes onto chitosan is proposed. The uptake of both Cu(II) and EDTA proceeds in weakly acidic (pH 3-5) and strongly alkaline (pH > 12) solutions. In acidic solutions EDTA sorption prevails. FT-IR investigations have shown that in acidic solutions the amide bonds between -COOH groups of EDTA and -NH2 groups of chitosan were formed. In alkaline solutions the single EDTA sorption does not proceed. In this media the sorption is enhanced by Cu(II) ions. The possible sorption mechanisms are discussed. The uptake of both Cu(II) and EDTA by chitosan depends on the ratio between them in solutions. EDTA sorption in acidic solutions increases with increase in its concentration while that of Cu(II) decreases. In alkaline solutions the sorption of both Cu(II) and EDTA increases with increase in Cu(II) concentration. The use of electrolysis enables to regenerate chitosan and to reuse it. During electrolysis copper is deposited onto the cathode and EDTA is oxidized onto the anode. The current efficiency depends on the current intensity, the load of chitosan and the pH of the background electrolyte. Electrolysis under the most favorable conditions ensures the 10-cycles regeneration without considerable changes in the sorption properties of chitosan. FT-IR spectra of the initial and regenerated chitosans are similar.

  6. Chitosan nanoparticle as gene therapy vector via gastrointestinal mucosa administration: results of an in vitro and in vivo study.

    PubMed

    Zheng, Fang; Shi, Xiao-Wen; Yang, Gui-Fang; Gong, Ling-Ling; Yuan, Hong-Yin; Cui, Ye-Jian; Wang, Yan; Du, Yu-Min; Li, Yan

    2007-01-02

    This study was designed to investigate the in vitro and in vivo transfection efficiency of chitosan nanoparticles used as vectors for gene therapy. Three types of chitosan nanoparticles [quaternized chitosan -60% trimethylated chitosan oligomer (TMCO-60%), C(43-45 KDa, 87%), and C(230 KDa, 90%)] were used to encapsulate plasmid DNA (pDNA) encoding green fluorescent protein (GFP) using the complex coacervation technique. The morphology, optimal chitosan-pDNA binding ratio and conditions for maximal in vitro transfection were studied. The in vivo transfection was conducted by feeding the chitosan/pDNA nanoparticles to 12 BALB/C-nu/nu nude mice. Both conventional and TMCO-60% could form stable nanoparticles with pDNA. The in vitro study showed the transfection efficiency to be in the following descending order: TMCO-60%>C(43-45 KDa, 87%)>C(230 KDa, 90%). TMCO-60% proved to be the most efficient and the optimal chitosan/pDNA ratio being 3.2:1. In vivo study showed most prominent GPF expression in the gastric and upper intestinal mucosa. GFP expression in the mucosa of the stomach and duodenum, jejunum, ileum, and large intestine were found, respectively, in 100%, 88.9%, 77.8% and 66.7% of the nude mice examined. TMCO-60%/pDNA nanoparticles had better in vitro and in vivo transfection activity than the other two, and with minimal toxicity, which made it a desirable non-viral vector for gene therapy via oral administration.

  7. Single-step electrochemical deposition of antimicrobial orthopaedic coatings based on a bioactive glass/chitosan/nano-silver composite system.

    PubMed

    Pishbin, F; Mouriño, V; Gilchrist, J B; McComb, D W; Kreppel, S; Salih, V; Ryan, M P; Boccaccini, A R

    2013-07-01

    Composite orthopaedic coatings with antibacterial capability containing chitosan, Bioglass® particles (9.8μm) and silver nanoparticles (Ag-np) were fabricated using a single-step electrophoretic deposition (EPD) technique, and their structural and preliminary in vitro bactericidal and cellular properties were investigated. Stainless steel 316 was used as a standard metallic orthopaedic substrate. The coatings were compared with EPD coatings of chitosan and chitosan/Bioglass®. The ability of chitosan as both a complexing and stabilizing agent was utilized to form uniformly deposited Ag-np. Due to the presence of Bioglass® particles, the coatings were bioactive in terms of forming carbonated hydroxyapatite in simulated body fluid (SBF). Less than 7wt.% of the incorporated silver was released over the course of 28days in SBF and the possibility of manipulating the release rate by varying the deposition order of coating layers was shown. The low released concentration of Ag ions (<2.5ppm) was efficiently antibacterial against Staphyloccocus aureus up to 10days. Although chitosan and chitosan/Bioglass® coating supported proliferation of MG-63 osteoblast-like cells up to 7days of culture, chitosan/Bioglass®/Ag-np coatings containing 342 μg of Ag-np showed cytotoxic effects. This was attributed to the relatively high concentration of Ag-np incorporated in the coatings.

  8. Iron casein succinylate-chitosan coacervate for the liquid oral delivery of iron with bioavailability and stability enhancement.

    PubMed

    Min, Kyoung Ah; Cho, Jung-Hye; Song, Yun-Kyoung; Kim, Chong-Kook

    2016-01-01

    Iron casein succinylate (ICS) liquid oral preparation as iron supplement has uncomfortable taste after a long period of storage because of its stability, and poor bioavailability of iron compared to any other iron preparations. To improve the chemical stability of ICS and enhance the bioavailability of iron, chitosan-ICS nanoparticles (NPs) were prepared by complex coacervation method and stabilized with polyethylene glycol (PEG) 400. NPs were spherical (mean diameter of 830-1070 nm) with positive charge (+30-60 mV) depending on the composition of NPs. Addition of PEG400 (2 w/v %) increased the zeta potential (26-50 %) and physical stability of chitosan-ICS NPs suspension. Also, NPs decreased iron release compared to ICS after 7-weeks of storage at 4 °C. NPs markedly increased the permeability of iron in Caco-2 cell up to 32-38-fold compared to ICS, while physical mixture of chitosan and ICS increased the iron permeability only 2.5-fold. In summary, NPs improved the physicochemical stability and enhanced the transport of iron compared to other iron preparations in Caco-2 cell model. Thus, chitosan-ICS coacervate might be a promising candidate as a liquid oral iron delivery system for iron deficiency patients with stability and bioavailability enhancement.

  9. Nanoindentation of Chitosan Doped with Silver Nanoparticles

    NASA Astrophysics Data System (ADS)

    Palumbo, Matthew; Teklu, Alem; Kuthirummal, Narayanan; Levi-Polyachenko, Nicole; Department of Physics; Astronomy, College of Charleston Collaboration; Department of Plastic; Reconstructive Surgery, Wake Forest University Health Sciences Collaboration

    Imaging and spectroscopic analysis via nanoindentation was performed with the Nanosurf EasyScan2 AFM on the pure and silver doped chitosan samples allowing for a more localized determination of their stiffness, hardness, and reduced Young's modulus. The pure chitosan sample was tested to have a stiffness of 0.367 N/m, a hardness of 1.12 GPa, and a reduced Young's modulus of 30.5 MPa. The film with 5mg Ag nanoparticle per gram of chitosan was tested on the boundaries between the chitosan and Ag nanoparticles to show an increase in stiffness of about 4.6% at 0.384 N/m, an increase in hardness of about 5.4% at 1.18 GPa, and an increase in the reduced Young's modulus of about 5.0% at 3.2 MPa in comparison to the pure chitosan sample. On the other hand, upon increasing the doping to 10mg Ag nanoparticle per gram of chitosan showed a decrease in stiffness of about 6.3% at 0.344 N/m, a decrease in hardness of about 27.0% at 0.820 GPa, and a decrease in the reduced Young's modulus of about 6.0% at 28.7 MPa in comparison to the pure chitosan sample. Obviously, films doped with 5mg Ag nanoparicle per gram of chitosan provided the composites with improved mechanical strength compared to chitosan alone.

  10. Alkaline phosphatase encapsulated in gellan-chitosan hybrid capsules.

    PubMed

    Fujii, Toshihiro; Ogiwara, Daisuke; Ohkawa, Kousaku; Yamamoto, Hiroyuki

    2005-05-23

    Alkaline phosphatase (ALP) was encapsulated in gellan-chitosan polyion complex (PIC) capsules using a convenient procedure. The recovery of ALP was about 50% when the capsules were prepared by dropping a solution of ALP and gellan mixture (ALP/gellan) into a chitosan solution. When p-nitrophenyl phosphate (p-NPP) and 5-bromo-4-chloro-3-indolyl phosphate (BCIP) were incubated with ALP/gellan-chitosan capsules as substrates for ALP, the transparent colorless capsules changed to yellow and blue, respectively. The encapsulation of ALP into the PIC capsules was also confirmed by SDS-PAGE and immunoblot analyses. The ALP and polypeptides of more than 30 kDa remained without release even after incubation at 4 degrees C for 14 d. The biochemical properties of the encapsulated ALP activity were similar to those of the intact enzyme. When the solution containing p-NPP was loaded on a column packed with ALP/gellan-chitosan capsules at 27 degrees C, approximately 75% of p-NPP was hydrolyzed by passing through the column. No significant leakage of ALP was observed during the procedure, indicating that the capsules were resistant to pressure in the chromatographic operation. Furthermore, 70% of the hydrolytic activity of the packed capsules remained after storage at 4 degrees C for one month. These results suggest that the polyion complex capsules could be useful materials for protein fixation without chemical modification. [Diagram: see text] Encapsulation of ALP into PIC capsules and the morphological changes seen in the absence of the ALP substrate and in the presence of p-NPP and BICP.

  11. Green polymer electrolytes based on chitosan and 1-butyl-3-methylimidazolium acetate

    SciTech Connect

    Shamsudin, Intan Juliana; Ahmad, Azizan; Hassan, Nur Hasyareeda

    2014-09-03

    Green polymer electrolytes based on chitosan as the polymer matrix and ionic liquid 1-butyl-3-methylimidazolium acetate [Bmim][OAc] as charge carriers were prepared by solution casting technique. Complexes with various amount of ionic liquid loading were investigated as possible ionic conducting polymers. The ionic conductivity was found to increase with increasing weight percent of ionic liquid. The highest ionic conductivity of the charged chitosan-[Bmim][OAc] was 2.44 × 10{sup −3} S cm{sup −1} at 90 wt.% of [Bmim][OAc] content at ambient temperature. Attenuated Total Reflection Fourier Transform infrared (ATR-FTIR) spectroscopy has proven the interaction between chitosan and [Bmim][OAc]. X-ray Diffraction (XRD) has shown that the amorphosity of the complexes increase as the amount of [Bmim][OAc] increase.

  12. Octaarginine-modified chitosan as a nonviral gene delivery vector: properties and in vitro transfection efficiency

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoli; Li, Zhaoyang; Liu, Wenguang; Lam, Wingmoon; Sun, Peng; Kao, Richard Y. T.; Luk, Keith D. K.; Lu, William W.

    2011-02-01

    Protein transduction domains (PTD) have been identified to have the capacity to facilitate molecular cargo to translocate through cell membrane. This study aims to utilize the cell membrane penetrating ability of octaarginine oligopeptide, a simplified prototype of the PTD, to enhance the transfection efficiency of chitosan. Octaarginine-modified chitosan (R8-CS) was synthesized as a gene transfer carrier by carbodiimide chemistry. The structure and composition of R8-CSs were characterized using FTIR and 1H NMR. Agarose gel electrophoresis assay showed that R8-CS could efficiently condense the DNA. The particle size of R8-CS/DNA complexes were determined to be around 100-200 nm. The nanoparticle complexes exhibited a spherical and compact morphology. R8-CS demonstrated higher transfection activity and lower cytotoxicity as compared to the unmodified chitosan and also showed good serum resistance.

  13. Effect of chitosan degradation on its interaction with β-lactoglobulin.

    PubMed

    Souza, Hiléia K S; Gonçalves, Maria do Pilar; Gómez, Javier

    2011-04-11

    Complexes between chitosan and β-lactoglobulin (β-Lg) were investigated, and their formation was found to depend on pH and ionic strength. The electrostatic attraction between the cationic polysaccharide and the negatively charged protein above its isoelectric point has been identified as the main driving force in the molecular recognition process. At low protein concentration, soluble complexes were shown to be formed, and their structural features were characterized by circular dichroism (CD) and steady-state fluorescence. Both the overall secondary structure of the protein and the local environment probed by its tryptophan residues are not affected by the presence of chitosan in the complex. Furthermore, the formation of the complex does not lead to a net stabilization of the native state of the protein over its denatured state due to formation of a similarly stable complex between the polyelectrolyte and the denatured state of the protein. The formation of coacervates between β-Lg and chitosan was also characterized as a function of average molecular weight of chitosan (subjected to ultrasonication for different periods of time: 0, 5, 15, and 30 min) by means of both turbidimetric and calorimetric techniques. The combination of turbidimetric as well as isothermal calorimetric titrations have allowed the deconvolution of two processes usually coupled in the formation of protein-polyelectrolyte coacervates: the formation of complex coacervates as the protein sites become saturated by polyelectrolyte molecules and the redissolution of the coacervates as the polyelectrolyte-to-protein ratio increases.

  14. Extraction and Separation of Fucoidan from Laminaria japonica with Chitosan as Extractant

    PubMed Central

    Xing, Ronge; Liu, Song; Yu, Huahua; Chen, Xiaolin; Qin, Yukun; Li, Kecheng; Li, Pengcheng

    2013-01-01

    Herein the extraction method of fucoidan from Laminaria japonica is reported. Firstly, chitosan, chitosan-N-2-hydroxypropyl trimethyl ammonium chloride (HACC), and hexadecyltrimethylammonium bromide (CPAB) were used to extract the fucoidan. The results showed that chitosan was the optimal extractant compared with the other two extractants. After extraction, different aqueous solutions, including NaCl, KCl, and HCl (pH2), were used to separate fucoidan from chitosan-fucoidan complex. The results showed that the separation ability of NaCl was slightly higher than that of KCl. Moreover, the price of NaCl is lower than that of KCl. Given the quality-price rate, NaCl solution was chosen as the separation solution. Thirdly, the concentration and ratio of NaCl solution : sediment influence the separation of fucoidan from chitosan-fucoidan complex. The results showed that the optimal separation conditions include 4 mol/L NaCl solution with the ratio of NaCl solution to sediment at 30 : 1. Fucoidan content was found to be affected by different separation time. Fucoidan content increased with the increase of separation time, and the optimal separation time was 6 h. Compared with traditional alkali extraction method, this method not only reduces the usage of alkali and acid and alleviate environment pollution, but also has the comparable extraction yield of fucoidan. It is a potential method for extraction of fucoidan. PMID:24350250

  15. Extraction and separation of fucoidan from Laminaria japonica with chitosan as extractant.

    PubMed

    Xing, Ronge; Liu, Song; Yu, Huahua; Chen, Xiaolin; Qin, Yukun; Li, Kecheng; Li, Pengcheng

    2013-01-01

    Herein the extraction method of fucoidan from Laminaria japonica is reported. Firstly, chitosan, chitosan-N-2-hydroxypropyl trimethyl ammonium chloride (HACC), and hexadecyltrimethylammonium bromide (CPAB) were used to extract the fucoidan. The results showed that chitosan was the optimal extractant compared with the other two extractants. After extraction, different aqueous solutions, including NaCl, KCl, and HCl (pH2), were used to separate fucoidan from chitosan-fucoidan complex. The results showed that the separation ability of NaCl was slightly higher than that of KCl. Moreover, the price of NaCl is lower than that of KCl. Given the quality-price rate, NaCl solution was chosen as the separation solution. Thirdly, the concentration and ratio of NaCl solution : sediment influence the separation of fucoidan from chitosan-fucoidan complex. The results showed that the optimal separation conditions include 4 mol/L NaCl solution with the ratio of NaCl solution to sediment at 30 : 1. Fucoidan content was found to be affected by different separation time. Fucoidan content increased with the increase of separation time, and the optimal separation time was 6 h. Compared with traditional alkali extraction method, this method not only reduces the usage of alkali and acid and alleviate environment pollution, but also has the comparable extraction yield of fucoidan. It is a potential method for extraction of fucoidan.

  16. Acyclovir delivery matrices based on poly(ethylene glycol)/chitosan semi-interpenetrating networks.

    PubMed

    Diez-Sales, O; Dolz, M; Hernandez, M J; Casanovas, A; Herraez, M

    2007-06-01

    Chitosan matrix systems have been studied as potential vehicles for the prolonged release of acyclovir (ACV). The influence of chitosan concentration (from 0.83% to 1.67%) on viscoelastic properties of formulations with and without glyoxal was analyzed. For chitosan-poly(ethylene glycol) 400 formulations loss modulus (G'') are greater than storage modulus (G'). This corresponds to the characteristic behavior of nonstructured systems. When glyoxal was added to the chitosan-poly(ethylene glycol) 400 formulations, gelled matrix was obtained (i.e., G' is higher than G''), except for the lowest chitosan concentration. ACV release rates for the both types of systems, with and without glyoxal, were also determined. The ACV diffusion coefficient values from matrices are less than for the respective formulation without glyoxal and it was found to depend on the crosslink density within the matrices. Viscoelastic parameters, dynamic moduli (G', G''), and complex viscosity (eta*), were correlated with the ACV diffusion coefficients (D). The complex viscosity (eta*) could be used as a parameter of predictive value for the release rate of drugs.

  17. Functional Performance of Chitosan/Carbopol 974P NF Matrices in Captopril Tablets

    PubMed Central

    Aguilar-López, Yuritze Alejandra

    2016-01-01

    Chitosan and Carbopol have been used to form a complex through an electrostatic interaction between the protonated amine (NH3+) group of chitosan and the carboxylate (COO−) group of Carbopol. In situ polyelectrolyte complexes formations based on the physical mixture of chitosan and sodium alginate were found and could be used as an oral controlled release matrix. The aim of this work is the assessment of a possible interaction between the particles of chitosan and Carbopol 974P NF that could modify their technological performance in captopril tablets. The drug and excipients were evaluated as mixtures of powders and tablets. The mixtures with captopril contained Carbopol 974P NF, chitosan, or a 1 : 1 mixture thereof with polymer proportions of 10%, 20%, and 30%. The evaluated parameters were the powder flow rate, the powder compressibility index, and the compactibility and release behavior of the tablets. The observed technological behavior points out to a greater interaction between the particles of polymers with different charge than between particles of the individual polymers. This produces more coherent matrices restricting more efficiently the drug dissolution, more coherent tablets with higher compactibility, and less flowing powder mixtures. All this, however, requires additional investigation to confirm the current results. PMID:27847674

  18. Preparation of chitosan nanofibers from completely deacetylated chitosan powder by a downsizing process.

    PubMed

    Aklog, Yihun Fantahun; Dutta, Ajoy Kumar; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Ifuku, Shinsuke

    2015-01-01

    Chitosan nanofibers were easily prepared from fully deacetylated chitosan dry powder using a high-pressure waterjet system. From SEM observation, after 10 cycles of treatment, most of the chitosan had been reduced to homogeneous nanofibers measuring tens of nanometers. On the other hand, further mechanical treatment did not show a significant change. Relative crystallinity of chitosan nanofibers gradually decreased as the number of passes increased since high-pressure waterjet treatment damaged the crystalline region of chitosan nanofibers. The transmittance of the chitosan nanofiber slurry increased steeply, as the number of passes increased, indicating that the chitosan fibers were disintegrated effectively. Viscosity of chitosan nanofiber slurry also showed that the chitosan disintegrated well into nanofibers up to 10 passes. Above 10 passes, disintegration efficiency was saturated. The molecular weights of the nanofibers steeply decreased due to the depolymerization of chitosan by mechanical disintegration. The Young's modulus and tensile strength of chitosan nanofiber sheets were improved as the number of treatments increased, but further treatments deteriorated the tensile strength.

  19. Mucoadhesion mechanism of chitosan and thiolated chitosan-poly(isobutyl cyanoacrylate) core-shell nanoparticles.

    PubMed

    Bravo-Osuna, Irene; Vauthier, Christine; Farabollini, Alessandra; Palmieri, Giovanni Filippo; Ponchel, Gilles

    2007-04-01

    The study is focused on the evaluation of the potential bioadhesive behaviour of chitosan and thiolated chitosan (chitosan-TBA)-coated poly(isobutyl cyanoacrylates) (PIBCA) nanoparticles. Nanoparticles were obtained by radical emulsion polymerisation with chitosan of different molecular weight and with different proportions of chitosan/chitosan-TBA. Mucoadhesion was ex vivo evaluated under static conditions by applying nanoparticle suspensions on rat intestinal mucosal surfaces and evaluating the amount of nanoparticles remaining attached to the mucosa after incubation. The analysis of the results obtained demonstrated that the presence of either chitosan or thiolated chitosan on the PIBCA nanoparticle surface clearly enhanced the mucoadhesion behaviour thanks to non-covalent interactions (ionic interaction and hydrogen bonds) with mucus chains. Both, the molecular weight of chitosan and the proportion of chitosan-TBA in the formulation influenced the nanoparticle hydrodynamic diameter and hence their transport through the mucus layer. Improved interpenetration ability with the mucus chain during the attachment process was suggested for the chitosan of high molecular weight, enhancing the bioadhesiveness of the system. The presence of thiol groups on the nanoparticle surface at high concentration (200 x 10(-6) micromol SH/cm2) increased the mucoadhesion capacity of nanoparticles by forming covalent bonds with the cysteine residues of the mucus glycoproteins.

  20. [Research of bio-performance of chitosan and chitosan being used for bacterial vaginosis].

    PubMed

    Cui, Huisu; Shi, Wei

    2012-03-01

    Discussing the chitosan' medical efficiency to treat Gynecology bacteria infectious disease by researching the bacteriostasis, biocompatibility of chitosan and analyzing the chitosan' medical efficiency to Bacterial vaginosis by clinical examination. The antibiotic experiment of chitosan to Candida albicans (ATCC 10231), Escherichia Coli (ATCC 25922) and Golden staphylococcus (ATCC 6538) has been studied in this paper. The vaginal irritation experimentation of chitosan to female rabbit and the sensitization experimentation of chitosan to guinea pig also have been conducted. To study the curative effect, we also coat a layer of chitosan in 20 patients' vagina. The Antibacterial rate of chitosan to Candida albicans is more than 98% and to Escherichia Coli is more than 99% and to Golden staphylococcus is more than 99%. Cytotoxicity of chitosan to vagina mucosa is grade 1 and sensitization of chitosan to vagina mucosa is none and stimulation of chitosan to vagina mucosa is very slightly. The total efficiency rate to treat Gynecology bacteria infectious disease is 90% and the cure rate is 75%.

  1. Adsorption studies of Cu(II) onto biopolymer chitosan and its nanocomposite 5%bentonite/chitosan.

    PubMed

    Moussout, Hamou; Ahlafi, Hammou; Aazza, Mustapha; Zegaoui, Omar; El Akili, Charaf

    2016-01-01

    Chitosan (CS) and nanocomposite 5%bentonite/chitosan (5%Bt/CS) prepared from the natural biopolymer CS were tested to remove Cu(II) ions using a batch adsorption experiment at various temperatures (25, 35 and 45°C). X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis (TGA/DTA) were used in CS and the nanocomposite characterisation. This confirmed the exfoliation of bentonite (Bt) to form the nanocomposite. The adsorption kinetics of copper on both solids was found to follow a pseudo-second-order law at each studied temperature. The Cu(II) adsorption capacity increased as the temperature increased from 25 to 45°C for nanocomposite adsorbent but slightly increased for CS. The data were confronted to the nonlinear Langmuir, Freundlich and Redlich-Peterson models. It was found that the experimental data fitted very well the Langmuir isotherm over the whole temperature and concentration ranges. The maximum monolayer adsorption capacity for the Cu(II) was 404-422 mg/g for CS and 282-337 mg/g for 5%Bt/CS at 25-45°C. The thermodynamic study showed that the adsorption process was spontaneous and endothermic. The complexation of Cu(II) with NH(2) and C = O groups as active sites was found to be the main mechanism in the adsorption processes.

  2. Antibacterial hydrogel coating by electrophoretic co-deposition of chitosan/alkynyl chitosan.

    PubMed

    Ding, Fuyuan; Nie, Zhen; Deng, Hongbing; Xiao, Ling; Du, Yumin; Shi, Xiaowen

    2013-11-06

    Despite much effort has been paid to develop aseptic implant devices, the infection associated with medical implant still remains a significant problem. Here, we report a potential coating material derived from a natural biopolymer chitosan. Firstly, chitosan functionalized with alkynyl moiety (ACS) was prepared by reaction between chitosan and 3-bromopropyne. The structure of the alkynyl chitosan was characterized by FT-IR, (1)H NMR, XRD, TGA and element analysis. The minimum inhibitory concentration (MIC) of ACS with a degree of substitution (DS) of 0.40 was 0.03% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Subsequently, the alkynyl chitosan was co-deposited with chitosan on stainless steel wire to fabricate a composite hydrogel. The composite hydrogel exhibited better antibacterial activities than pure chitosan hydrogel.

  3. Complexity.

    PubMed

    Gómez-Hernández, J Jaime

    2006-01-01

    It is difficult to define complexity in modeling. Complexity is often associated with uncertainty since modeling uncertainty is an intrinsically difficult task. However, modeling uncertainty does not require, necessarily, complex models, in the sense of a model requiring an unmanageable number of degrees of freedom to characterize the aquifer. The relationship between complexity, uncertainty, heterogeneity, and stochastic modeling is not simple. Aquifer models should be able to quantify the uncertainty of their predictions, which can be done using stochastic models that produce heterogeneous realizations of aquifer parameters. This is the type of complexity addressed in this article.

  4. Antibacterial and antioxidative activity of O-amine functionalized chitosan.

    PubMed

    Tamer, Tamer M; Hassan, Mohamed A; Omer, Ahmed M; Valachová, Katarína; Eldin, Mohamed S Mohy; Collins, Maurice N; Šoltés, Ladislav

    2017-08-01

    Cinnamaldehyde was immobilized to O-amine functionalized chitosan via a coupling reaction. Fourier transform infrared spectroscopy confirmed N-cinnamyl substitution. Wetting analyses demonstrate more hydrophobicity in the N-cinnamyl substituted O-amine functionalized chitosan compared to chitosan or unsubstituted O-amine functionalized chitosan. Thermal gravimetric analysis and differential scanning calorimetry demonstrates that the prepared N-cinnamyl substituted O-amine functionalized chitosan exhibits higher thermostability than unmodified chitosan at temperatures in which polysaccharides are commonly stored and utilised. The N-cinnamyl substituted O-amine functionalized chitosan, against four different bacteria strains [two gram-positive (Staphylococcus aureus and Bacillus cereus) and two gram-negative (Escherichia coli and Pseudomonas aeruginosa)], displays promotion of inhibition activity against these bacterial strains. Finally, the antioxidative activity of the N-cinnamyl substituted O-amine functionalized chitosan was compared with those activities of chitosan and O-amine functionalized chitosan. This was evaluated by uninhibited and inhibited hyaluronan degradation and ABTS assay. The N-cinnamyl substituted O-amine functionalized chitosan shows a lower activity towards donating a hydrogen radical compared to chitosan or O-amine functionalized chitosan. On the other hand, the N-cinnamyl substituted O-amine functionalized chitosan exhibited a higher ability to scavenge the ABTS(+) cation radical compared to chitosan and O-amine functionalized chitosan. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Preparation and characterisation of zein and chitosan edible film

    USDA-ARS?s Scientific Manuscript database

    The aim of this work was to develop zein/chitosan blends and study the heat effect on chitosan in the film-making process. The zein and chitosan solutions were prepared separately; two different chitosan solutions were produced, one heated at 80 ºC for 1 h, and another just stirred for 1 h and unhea...

  6. Fragmentation of Chitosan by Acids

    PubMed Central

    Arul, Joseph; Charlet, Gérard

    2013-01-01

    Fragmentation of chitosan in aqueous solution by hydrochloric acid was investigated. The kinetics of fragmentation, the number of chain scissions, and polydispersity of the fragments were followed by viscometry and size exclusion chromatography. The chemical structure and the degree of N-acetylation (DA) of the original chitosan and its fragments were examined by 1H NMR spectroscopy and elemental analysis. The kinetic data indicates that the reaction was of first order. The results of polydispersity and the DA suggest that the selected experimental conditions (temperature and concentration of acid) were appropriate to obtain the fragments having the polydispersity and the DA similar to or slightly different from those of the original one. A procedure to estimate molecular weight of fragments as well as the number of chain scissions of the fragments under the experimental conditions was also proposed. PMID:24302858

  7. Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery

    PubMed Central

    Ahmed, Tarek A; Aljaeid, Bader M

    2016-01-01

    Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated. PMID:26869768

  8. Topical formulations and wound healing applications of chitosan.

    PubMed

    Ueno, H; Mori, T; Fujinaga, T

    2001-11-05

    Chitosan is being used as a wound-healing accelerator in veterinary medicine. To our knowledge, chitosan enhances the functions of inflammatory cells such as polymorphonuclear leukocytes (PMN) (phagocytosis, production of osteopontin and leukotriene B4), macrophages (phagocytosis, production of interleukin (IL)-1, transforming growth factor beta 1 and platelet derived growth factor), and fibroblasts (production of IL-8). As a result, chitosan promotes granulation and organization, therefore chitosan is beneficial for the large open wounds of animals. However, there are some reported complications of chitosan application. Firstly, chitosan causes lethal pneumonia in dogs which are given a high dose of chitosan. In spite of application of chitosan to various species, this finding is observed only in dogs. Secondly, intratumor injection of chitosan on mice bearing tumor increases the rate of metastasis and tumor growth. Therefore, it is important to consider these effects of chitosan, prior to drug delivery.

  9. Characterization of Chitosan Nanofiber Sheets for Antifungal Application

    PubMed Central

    Egusa, Mayumi; Iwamoto, Ryo; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Kaminaka, Hironori; Ifuku, Shinsuke

    2015-01-01

    Chitosan produced by the deacetylation of chitin is a cationic polymer with antimicrobial properties. In this study, we demonstrate the improvement of chitosan properties by nanofibrillation. Nanofiber sheets were prepared from nanofibrillated chitosan under neutral conditions. The Young’s modulus and tensile strength of the chitosan NF sheets were higher than those of the chitosan sheets prepared from dissolving chitosan in acetic acid. The chitosan NF sheets showed strong mycelial growth inhibition against dermatophytes Microsporum and Trichophyton. Moreover, the chitosan NF sheets exhibited resistance to degradation by the fungi, suggesting potentials long-lasting usage. In addition, surface-deacetylated chitin nanofiber (SDCNF) sheets were prepared. The SDCNF sheet had a high Young’s modulus and tensile strength and showed antifungal activity to dermatophytes. These data indicate that nanofibrillation improved the properties of chitosan. Thus, chitosan NF and SDCNF sheets are useful candidates for antimicrobial materials. PMID:26540046

  10. Chitosan/Hyaluronic Acid Nanoparticles: Rational Design Revisited for RNA Delivery.

    PubMed

    Lallana, Enrique; Rios de la Rosa, Julio M; Tirella, Annalisa; Pelliccia, Maria; Gennari, Arianna; Stratford, Ian J; Puri, Sanyogitta; Ashford, Marianne; Tirelli, Nicola

    2017-07-03

    Chitosan/hyaluronic acid (HA) nanoparticles can be used to deliver an RNA/DNA cargo to cells overexpressing HA receptors such as CD44. For these systems, unequivocal links have not been established yet between chitosan macromolecular (molecular weight; degree of deacetylation, i.e., charge density) and nanoparticle variables (complexation strength, i.e., stability; nucleic acid protection; internalization rate) on one hand, and transfection efficiency on the other hand. Here, we have focused on the role of avidity on transfection efficiency in the CD44-expressing HCT-116 as a cellular model; we have employed two differently sized payloads (a large luciferase-encoding mRNA and a much smaller anti-Luc siRNA), and a small library of chitosans (variable molecular weight and degree of deactylation). The RNA avidity for chitosan showed-as expected-an inverse relationship: higher avidity-higher polyplex stability-lower transfection efficiency. The avidity of chitosan for RNA appears to lead to opposite effects: higher avidity-higher polyplex stability but also higher transfection efficiency. Surprisingly, the best transfecting particles were those with the lowest propensity for RNA release, although this might be a misleading relationship: for example, the same macromolecular parameters that increase avidity can also boost chitosan's endosomolytic activity, with a strong enhancement in transfection. The performance of these nonviral vectors appears therefore difficult to predict simply on the basis of carrier- or payload-related variables, and a more holistic consideration of the journey of the nanoparticle, from cell uptake to cytosolic bioavailability of payload, is needed. It is also noteworthy that the nanoparticles used in this study showed optimal performance under slightly acidic conditions (pH 6.4), which is promising for applications in a tumoral extracellular environment. It is also worth pointing out that under these conditions we have for the first time

  11. Chitosan crosslinked microparticles with encapsulated polyphenols: Water sorption and release properties.

    PubMed

    Trifković, Kata; Milašinović, Nikola; Djordjević, Verica; Zdunić, Gordana; Kalagasidis Krušić, Melina; Knežević-Jugović, Zorica; Šavikin, Katarina; Nedović, Viktor; Bugarski, Branko

    2015-11-01

    Chitosan-glutaraldehyde microparticles were produced by emulsion crosslinking method to be used as drug delivery system for polyphenols from Thymus serpyllum L. aqueous extract. The effect of preparation conditions, chitosan concentration (1.5-3% w/v), and glutaraldehyde/chitosan (GA/Ch) mass ratio (0.15-1.20) on water and polyphenols transport properties was investigated. Swelling ratio of dry particles (68-230 µm) in water ranged from 280% to 530%, depending on the formulation. The decrease in swelling was observed with increased GA/Ch mass ratio (i.e. crosslinking degree) at the same chitosan concentration, or with increased chitosan concentration at the same GA/Ch mass ratio. The increase in GA/Ch mass ratio was also manifested by increased particle compactness i.e. decreased size and reduced surface roughness. The sorption capacity for polyphenols seems to be a complex interplay of swelling behaviour and interactions chitosan-glutaraldehyde-polyphenols identified by Fourier transmission infrared analysis. An increase in crystallinity of chitosan was observed upon crosslinking with glutaraldehyde and encapsulation of polyphenols, as observed by X-ray diffraction analysis. The results obtained from release kinetics of selected polyphenolic compounds (caffeic acid, rosmarinic acid, total flavonoids, and total phenol content) showed that polyphenols were released at a lower amount (2-4 times) in water, but more rapidly (45-120 min) in comparison with the release in gastric followed by intestinal simulated fluid (SGF-SIF) (120-240 min). The experimental results of the time-dependent swelling in water and polyphenols release in both, water and SGF-SIF, were analyzed with several mathematical models. The results depicted Fickian diffusion as the water transport mechanism. In the case of polyphenols, only empirical Weibull model could be suggested for describing release kinetics. © The Author(s) 2015.

  12. Chitosan and its antimicrobial potential – a critical literature survey

    PubMed Central

    Raafat, Dina; Sahl, Hans‐Georg

    2009-01-01

    Summary Chitosan, an aminopolysaccharide biopolymer, has a unique chemical structure as a linear polycation with a high charge density, reactive hydroxyl and amino groups as well as extensive hydrogen bonding. It displays excellent biocompatibility, physical stability and processability. The term ‘chitosan’ describes a heterogenous group of polymers combining a group of physicochemical and biological characteristics, which allow for a wide scope of applications that are both fascinating and as yet uncharted. The increased awareness of the potentials and industrial value of this biopolymer lead to its utilization in many applications of technical interest, and increasingly in the biomedical arena. Although not primarily used as an antimicrobial agent, its utility as an ingredient in both food and pharmaceutical formulations lately gained more interest, when a scientific understanding of at least some of the pharmacological activities of this versatile carbohydrate began to evolve. However, understanding the various factors that affect its antimicrobial activity has become a key issue for a better usage and a more efficient optimization of chitosan formulations. Moreover, the use of chitosan in antimicrobial systems should be based on sufficient knowledge of the complex mechanisms of its antimicrobial mode of action, which in turn would help to arrive at an appreciation of its entire antimicrobial potential. PMID:21261913

  13. Chitosan: a versatile biopolymer for orthopaedic tissue-engineering.

    PubMed

    Di Martino, Alberto; Sittinger, Michael; Risbud, Makarand V

    2005-10-01

    Current tissue engineering strategies are focused on the restoration of pathologically altered tissue architecture by transplantation of cells in combination with supportive scaffolds and biomolecules. In recent years, considerable attention has been given to chitosan (CS)-based materials and their applications in the field of orthopedic tissue engineering. Interesting characteristics that render chitosan suitable for this purpose are a minimal foreign body reaction, an intrinsic antibacterial nature, and the ability to be molded in various geometries and forms such as porous structures, suitable for cell ingrowth and osteoconduction. Due to its favorable gelling properties chitosan can deliver morphogenic factors and pharmaceutical agents in a controlled fashion. Its cationic nature allows it to complex DNA molecules making it an ideal candidate for gene delivery strategies. The ability to manipulate and reconstitute tissue structure and function using this material has tremendous clinical implications and is likely to play a key role in cell and gene therapies in coming years. In this paper we will review the current applications and future directions of CS in articular cartilage, intervertebral disk and bone tissue engineering.

  14. Effect of chitosan content on gel content of epoxized natural rubber grafted with chitosan in latex form.

    PubMed

    Riyajan, Sa-Ad; Sukhlaaied, Wattana

    2013-04-01

    The epoxidized natural rubber (ENR) latex-g-chitosan (ENR-g-chitosan) was prepared in latex form using potassium persulphate as an initiator. Firstly, the reduction in molecular weight of chitosan was subjected to the addition of K2S2O8 at 70 °C for 15 min. The structure of the modified chitosan was characterized by ATR-FTIR. Secondarily, the influence of chitosan contents, reaction time, and temperature and K2S2O8 concentrations on the gel content of the modified ENR was investigated. The chemical structure of the ENR-g-chitosan was confirmed by (1)H-NMR and ATR-FTIR. The ether linkage of the ENR-g-chitosan was conformed at 1154 an 1089 cm(-1) by ATR-FTIR and 3.60 ppm by (1)H-NMR. The gel content of ENR-g-chitosan at 5% chitosan showed the highest value compared with other samples. But when chitosan increased from 5% to 10% or 20%, the gel content of ENR-g-chitosan dramatically decreased. The ENR-g-chitosan showed good thermal resistance due to incorporation of chitosan. The morphology of ENR-g-chitosan particle showed the core-shell structure observed by TEM. The optimum condition of grafting ENR with chitosan was found at 65°C for 3h of reaction time, ratio of ENR/chitosan at 9:1.

  15. The effect of continuous release of recombinant human epidermal growth factor (rh-EGF) in chitosan film on full thickness excisional porcine wounds.

    PubMed

    Hong, Joon Pio; Kim, Yeun Wha; Lee, Sang Kil; Kim, Sun Hee; Min, Kyung Hyun

    2008-10-01

    The purpose of this article is to evaluate the effect of continuously released recombinant human epidermal growth factor (rh-EGF) in chitosan film in full thickness porcine wounds. A total of 10 domestic pigs (Yorkshire species) weighing 18 to 22 kg between the ages of 50 to 60 days were used. The wounds were divided into 3 groups and treated selectively with rh-EGF in chitosan film (EGF 20 ug/wound/d), chitosan film without rh-EGF, or remained as the control group. One hundred percent healing time was observed, and hematoxylin and eosin and Anti Ki-67 antibody immunohistochemical staining were performed. The 100% healing time and Anti Ki-67 antibody immunohistochemical staining showed statistical significance of the rh-EGF chitosan film-treated group against the control group (P < 0.05). But it did not reveal any statistical significance over the chitosan film-treated group. In this preliminary study, although continuous release of rh-EGF in chitosan film accelerates epithelialization, the benefit of the combination of rh-EGF in chitosan cannot be determined over the use of chitosan alone. Further analysis using complex wound models such as diabetes or infection, which may have different pathology in healing, will be needed to evaluate the potential benefit/synergistic effectiveness.

  16. Enzyme-sensing chitosan hydrogels.

    PubMed

    Sadat Ebrahimi, Mir Morteza; Schönherr, Holger

    2014-07-08

    We report on a chitosan hydrogel-based platform for the detection of enzymes, which is compatible with the implementation in infection-sensing wound dressings. Thin films of the established wound dressing biopolymer chitosan were functionalized with a fluorogenic substrate, which is released upon enzymatic degradation, resulting in a pronounced increase in fluorescence emission intensity. In this first model study, the fluorogenic substrate alanyl-alanyl-phenylalanine-7-amido-4-methylcoumarin (AAP-AMC) was covalently conjugated via amide bond formation to chitosan and was shown to facilitate the detection of the serine protease α-chymotrypsin. Systematic investigations established the dependence of hydrogel thickness and substrate loading on the hydrogel preparation conditions, as well as the dependence of the rate of the reaction on the initial enzyme concentration and the loading of AAP-AMC in the hydrogel. The initial release rate of the fluorophore 7-AMC was found to be linear with enzyme concentration and substrate loading and was independent of hydrogel thickness. Under optimized conditions the hydrogel reports the presence of α-chymotrypsin in <5 min with a limit of detection of ≤10 nM. This generic approach, which can be adapted to detect different kinds of enzymes by using appropriate fluorogenic or chromogenic substrates, is highly interesting for targeting the detection of specific pathogenic bacteria, e.g., in wound dressings.

  17. Ultrasound Treatment Increases Transfection Efficiency of Low Molecular Weight Chitosan in Fibroblasts but Not in KB Cells

    PubMed Central

    Kedjarune-Leggat, Ureporn; Supaprutsakul, Chanyapat; Chotigeat, Wilaiwan

    2014-01-01

    The aim of this study was to optimize transfection efficiency (TE) of the depolymerized low molecular weight (LW) chitosan with molecular weight (Mw) at 16 kDa and 54% degree of deacetylation (DDA) on three primary cells of fibroblast (F), dental pulp (P), and periodontal ligament (PDL). The effect of low frequency ultrasound treatment on the chitosan-DNA complexes prior transfection on TE was also evaluated. This LW chitosan required high N/P ratio (>34) to bind DNA completely. An N/P ratio above 56 tended to improve TE in most primary cells nearly at the level of Lipofectamine. Ultrasonication can reduce the aggregation and sizes of the chitosan-DNA microparticles. It increased TE of F cells at an N/P ratio above 34, which was higher than Lipofectamine. However, this ultrasound treatment caused loss of TE in KB cells. MTT assay of these chitosan-DNA complexes revealed no significant cytotoxicity to both KB and F cells. This LW chitosan has potential for further development into a safer alternative to gene delivery systems in various cells of interest; however the optimal conditions have to be adjusted, depending on each cell source. PMID:24651870

  18. Characterization of calcium carbonate/chitosan composites

    SciTech Connect

    Gonsalves, K.E.; Zhang, S.

    1995-12-31

    The crystal growth of calcium carbonate on a chitosan substrate was achieved using a supersaturated calcium carbonate solution, by using various additives, polyacrylic acid (PAA). Polyacrylic acid modified the chitosan-film surface and promoted the nucleation of calcium carbonate crystals.

  19. Synthesis and characterization of chitosan alkyl urea.

    PubMed

    Wang, Jing; Jiang, Ji-Zhou; Chen, Wei; Bai, Zheng-Wu

    2016-07-10

    Chitosan is a versatile material employed for various purposes in many fields including the development of chiral stationary phases for enantioseparation. Chitosan alkyl urea is a kind of intermediate used to prepare enantioseparation materials. In order to synthesize the intermediates, in the present work, a new way to prepare chitosan alkyl urea has been established: chitosan was first reacted with methyl chloroformate yielding N-methoxyformylated chitosan, which was then converted to chitosan alkyl urea through amine-ester exchange reaction. With a large excess of methyl chloroformate and primary amine of low stereohindrance, the amino group in chitosan could be almost completely converted to ureido group. The as-prepared chitosan alkyl urea derivatives were characterized by IR, (1)H NMR, (13)C NMR,(1)H-(1)H COSY and (1)H-(13)C HSQC NMR spectra. The chemical shifts of hydrogen and carbon atoms of glucose unit were assigned. It was found that the degree of substitution was obviously lower if cyclopropyl amine, aniline, tert-butyl amine and diethyl amine were used as reactants for the amine-ester exchange reaction. The reason was explained with the aid of theoretical calculations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Relative charge density model on chitosan-fucoidan electrostatic interaction: qualitative approach with element analysis.

    PubMed

    Lee, Eun Ju; Lim, Kwang-Hee

    2015-02-01

    This paper proposes a relative charge density model of prepared chitosan-fucoidan nanoparticles (CFNs) to provide insight into an analysis of the ionic interactions in terms of polyelectrolyte complexes. Using the relative charge density model, the extent of the ionic interactions is predicted in terms of the pH (2 through 6) and used fucoidan to chitosan mass ratio (FCMR) (1:0.05 through 1:1), through which the formation of CFNs can be controlled to be ranked qualitatively according to size and stability. It was confirmed by the measurements of their zeta potentials and sizes and by the analysis of their decay with time. Moreover, the relative charge density model was validated to predict the isoelectric condition of a polyelectrolyte complexed suspension of CFNs. Elemental analysis with a proper mass-conversion showed that the ratio of the stoichiometric coefficients of sulfate groups to amino groups in CFNs formed were almost consistent to that of the sulfate groups to amino groups in a chitosan solution mixed with a fucoidan solution prior to the occurrence of polyelectrolyte complexation. In a pH 2-environment, there were locally intensive electrostatic interactions with a low yield to form sulfate group-rich CFNs. In contrast, in a pH 6-environment, extensive electrostatic interactions occurred to form sulfate group-poor CFNs with a high yield. In addition to the chitosan-amide groups, the separate yield-distribution of loaded chitosan indicated the possible involvement of positively charged amino groups in the electrostatic interactions among chitosan molecules. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. Multifaceted Applications of Chitosan in Cancer Drug Delivery and Therapy.

    PubMed

    Babu, Anish; Ramesh, Rajagopal

    2017-03-27

    Chitosan is a versatile polysaccharide of biological origin. Due to the biocompatible and biodegradable nature of chitosan, it is intensively utilized in biomedical applications in scaffold engineering as an absorption enhancer, and for bioactive and controlled drug release. In cancer therapy, chitosan has multifaceted applications, such as assisting in gene delivery and chemotherapeutic delivery, and as an immunoadjuvant for vaccines. The present review highlights the recent applications of chitosan and chitosan derivatives in cancer therapy.

  2. Bioadhesive nanoparticles of fungal chitosan for oral DNA delivery.

    PubMed

    Plapied, Laurence; Vandermeulen, Gaëlle; Vroman, Benoît; Préat, Véronique; des Rieux, Anne

    2010-10-15

    Chitosan is an ideal candidate for oral DNA delivery due to its mucoadhesive properties. Chitosan (CS) produced under GMP conditions from fungal source was used to encapsulate a plasmid DNA coding for a reporter gene. Nanoparticles made by complex coacervation of CS and DNA had a size around 200 nm, a positive zeta potential, a high association of DNA and protected the plasmid against nuclease degradation. Their transfection ability was assessed in differentiated intestinal Caco-2 cells. An N/P ratio of 4 and a DNA concentration of 8 microg/ml were the optimal conditions leading to a transfection efficiency similar to the one reached with polyethyleneimine (PEI)-DNA complexes without cytotoxicity. M cells in monolayers influenced DNA uptake up to 8 microg of DNA/ml when complexed with CS. Fungal trimethylchitosan was also tested but the complexes interactions were too strong to induce transfection in vitro. Confocal microscopy studies showed that CS/DNA and PEI/DNA nanoparticles were found at the apical surface of cell monolayers and DNA was co-localized within the nucleus. Quantification seemed to show that more DNA was associated with the cells when incubated with CS nanoparticles and that the presence of M cells slightly influenced DNA uptake when complexed with CS. In conclusion, we developed a new nanocarrier made of fungal CS promising for oral gene delivery and oral DNA vaccination.

  3. Hydrogels made from chitosan and silver nitrate.

    PubMed

    Kozicki, Marek; Kołodziejczyk, Marek; Szynkowska, Małgorzata; Pawlaczyk, Aleksandra; Leśniewska, Ewa; Matusiak, Aleksandra; Adamus, Agnieszka; Karolczak, Aleksandra

    2016-04-20

    This work describes a gelation of chitosan solution with silver nitrate. Above the critical concentration of chitosan (c*), continuous hydrogels of chitosan-silver can be formed. At lower concentrations, the formation of nano- and micro-hydrogels is discussed. The sol-gel analysis was performed to characterise the hydrogels' swelling properties. Moreover, the following were employed: (i) mechanical testing of hydrogels, (ii) inductively coupled plasma-optical emission spectroscopy (ICP-OES) for the measurement of silver concentration, (iii) scanning electron microscopy (SEM) to examine the morphology of products obtained, and (iv) dynamic light scattering (DLS) and UV-vis spectrophotometry to examine products formed at low concentration of chitosan (cchitosan used that showed no such activity.

  4. Chitosan nanofiber production from Drosophila by electrospinning.

    PubMed

    Kaya, Murat; Akyuz, Bahar; Bulut, Esra; Sargin, Idris; Eroglu, Fatma; Tan, Gamze

    2016-11-01

    Drosophila melanogaster is one of the important test organisms in genetics thanks to its fast growth rate in a culture. This study demonstrates that the fly D. melanogaster can also be exploited as a source for nanofiber production in biotechnical applications. First, its chitin content was determined (7.85%) and then high molecular weight chitosan (141.4kDa) was synthesized through deacetylation of chitin isolates. Chitosan nanofibers with the diameter of 40.0073±12.347nm were produced by electrospinning of Drosophila chitosan. The physicochemical properties of obtained chitin and chitosan from D. melanogaster were determined by Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). The study demonstrated that the fly D. melanogaster can be utilized for production of chitosan nanofiber concerning its cultivability and low-cost culture requirements.

  5. Chitosan magnetic nanoparticles for drug delivery systems.

    PubMed

    Assa, Farnaz; Jafarizadeh-Malmiri, Hoda; Ajamein, Hossein; Vaghari, Hamideh; Anarjan, Navideh; Ahmadi, Omid; Berenjian, Aydin

    2017-06-01

    The potential of magnetic nanoparticles (MNPs) in drug delivery systems (DDSs) is mainly related to its magnetic core and surface coating. These coatings can eliminate or minimize their aggregation under physiological conditions. Also, they can provide functional groups for bioconjugation to anticancer drugs and/or targeted ligands. Chitosan, as a derivative of chitin, is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Chitosan nanoparticles (NPs), due to their huge surface to volume ratio as compared to the chitosan in its bulk form, have outstanding physico-chemical, antimicrobial and biological properties. These unique properties make chitosan NPs a promising biopolymer for the application of DDSs. In this review, the current state and challenges for the application magnetic chitosan NPs in drug delivery systems were investigated. The present review also revisits the limitations and commercial impediments to provide insight for future works.

  6. Functional properties of chitosan-based films.

    PubMed

    Leceta, I; Guerrero, P; de la Caba, K

    2013-03-01

    Chitosan-based films plasticized with glycerol were prepared by casting with the aim to obtain environmentally friendly materials for packaging applications. Different contents of glycerol were incorporated into chitosan solutions to improve mechanical properties and all films obtained were flexible and transparent. It was observed that the transparency and good behaviour of the films against UV radiation were not affected by chitosan molecular weight or glycerol content. Moreover, chitosan-based films exhibited excellent barrier properties against water vapour and oxygen, even with the addition of glycerol. The effect of the plasticizer on the properties has been explained using Fourier transform infrared (FTIR) spectroscopic analysis. The changes observed in the intensity of the bands showed that glycerol interacts with chitosan, which could be confirmed by total soluble matter (TSM). Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Biodegradable chitosan nanogels crosslinked with genipin.

    PubMed

    Arteche Pujana, Maite; Pérez-Álvarez, Leyre; Cesteros Iturbe, Luis Carlos; Katime, Issa

    2013-05-15

    Chitosan nanoparticles crosslinked with genipin were prepared by reverse microemulsion that allowed to obtain highly monodisperse (3-20 nm by TEM) nanogels. The incorporation of genipin into chitosan was confirmed and quantitatively evaluated by UV-vis and (1)H NMR. Loosely crosslinked chitosan networks showed higher water solubility at neutral pHs than pure chitosan. The hydrodynamic diameter of the genipin-chitosan nanogels ranged from 270 to 390 nm and no remarkable differences were found when the crosslinking degree was varied. The hydrodynamic diameters of the nanoparticles increased slightly at acidic pH and the protonation of ionizable amino groups with the pH was confirmed by the zeta potential measurements. The biocompatible and biodegradable nature, as well as the colloidal and monodisperse particle size of the prepared nanogels, make them attractive candidates for a large variety of biomedical applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Enhancing effects of chitosan and chitosan hydrochloride on intestinal absorption of berberine in rats.

    PubMed

    Chen, Wei; Fan, Dongjiao; Meng, Lingkuo; Miao, Yuqiang; Yang, Shenshen; Weng, Yan; He, Haibing; Tang, Xing

    2012-01-01

    Berberine chloride (BBR) is a plant alkaloid that has been used for centuries for treatment of inflammation, dysentery, and liver diseases. It is poorly absorbed from the gastrointestinal (GI) tract and its various clinical uses are limited because of its poor bioavailability. The object of the present study was to investigate the absorption enhancing effect of chitosan on BBR. Mixtures of BBR and chitosan were prepared and the absorption enhancement was investigated in rats. The results showed a dose-dependent absorption enhancement produced by chitosan. Formulations containing 0.5%, 1.5%, and 3.0% chitosan resulted in improvement of AUC(0-36 h) values by 1.9, 2.2, 2.5 times. The absorption enhancing ability of chitosan may be due to its ability to improve the BBR paracellular pathway in the intestinal tract. Chitosan hydrochloride, a salt of chitosan, was also investigated in this study. However, the addition of 2.0% and 3.3% chitosan hydrochloride to BBR solution did not produce any increase in either C(max) or AUC(0-36 h) of BBR. Subsequent solubility studies suggested that the reduced berberine chloride solubility in chitosan hydrochloride may limit the enhancement ability. This study showed that the optimum formulation producing the highest BBR absorption is the BBR solution containing 3.0% chitosan.

  9. Antioxidant activity of high molecular weight chitosan and N,O-quaternized chitosans.

    PubMed

    Wan, Ajun; Xu, Qing; Sun, Yan; Li, Huili

    2013-07-17

    The objective of this study was to evaluate the in vitro antioxidant activity of high molecular weight chitosan based films. Three kinds of water-soluble quaternized chitosans with high molecular weight, namely N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (400-HTCC and 1240-HTCC), N-(2-hydroxyl) propyl-3-triethyl ammonium chitosan chloride (400-HTEC and 1240-HTEC), and O-(2-hydroxyl) propyl-3- trimethyl ammonium chitosan chloride (400-O-HTCC) were prepared from high molecular weight chitosans (400 and 1240 kDa). The in vitro antioxidant activity of a high molecular weight chitosan (1240-CS) and five quaternized chitosans was evaluated and compared as radical scavengers against 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH•), hydroxyl radical (•OH), and superoxide radical (•O2(-)) using established methods, and the effect of the molecular weight, the concentration, the newly generated hydroxyl group, the extra introduced positive charge of quaternary ammonium salt group, etc., on the antioxidant activity of these high molecular weight chitosans is discussed. The data obtained in vitro models exhibited good antioxidant potency and suggested the possibility that high molecular weight chitosan based films could be effectively employed as natural antioxidant materials for application in the field of food and medicine.

  10. Antimicrobial and antitumor activities of chitosan from shiitake stipes, compared to commercial chitosan from crab shells.

    PubMed

    Chien, Rao-Chi; Yen, Ming-Tsung; Mau, Jeng-Leun

    2016-03-15

    Chitosan was prepared by alkaline N-deacetylation of chitin obtained from shiitake stipes and crab shells and its antimicrobial and antitumor activities were studied. Chitosan from shiitake stipes and crab shells exhibited excellent antimicrobial activities against eight species of Gram positive and negative pathogenic bacteria with inhibition zones of 11.4-26.8mm at 0.5mg/ml. Among chitosan samples, shiitake chitosan C120 was the most effective with inhibition zones of 16.4-26.8mm at 0.5mg/ml. In addition, shiitake and crab chitosan showed a moderate anti-proliferative effect on IMR 32 and Hep G2 cells. At 5mg/ml, the viability of IMR 32 cells incubated with chitosan was 68.8-85.0% whereas that of Hep G2 cells with chitosan was 60.4-82.9%. Overall, shiitake chitosan showed slightly better antimicrobial and antitumor activities than crab chitosan. Based on the results obtained, shiitake and crab chitosan were strong antimicrobial agents and moderate antitumor agents.

  11. Recent research progress on preparation and application of N, N, N-trimethyl chitosan.

    PubMed

    Wu, Meiyan; Long, Zhu; Xiao, Huining; Dong, Cuihua

    2016-11-03

    N,N,N-trimethyl chitosan (TMC) is a quaternized chitosan derivative with excellent solubility in aqueous solutions. It has been extensively studied as an absorption enhancer, antibacterial agent and gene vector due to its ability to form complexes with anionic gels or macromoleculars. However, the research which describes the process of TMC preparation and its new applications has not been fully reviewed. In this paper, recent progress regarding different TMC preparation methods and its characterization and application in different fields is presented. Key findings are compared and summarized and some topics for further study are suggested.

  12. Production and analysis of the biopolymer chitosan from Mucor rouxii. Final report, December 1985-July 1987

    SciTech Connect

    Arcidiacono, S.; Kaplan, D.L.

    1987-11-01

    To determine the potential for the production of chitosan with physiochemical properties from a fungal source, growth studies were conducted using Mucor rouxii. Growth of the organism under a variety of conditions was studied to determine the effects on polymer molecular-weight distributions and biomass production. Modifications of processing protocols were also evaluated to examine the effects of yields of chitosan extracted from the fungal cell wall as well as molecular-weight distribution. This represents the first such study where these factors were correlated to the yield and molecular-weight distribution of chitosan. Of the growth parameters evaluated, length of incubation, culture volume, source of inorganic salt in defined medium, and medium component concentration in complex medium had an effect on biomass and MW distributions. Processing parameters affecting the amount of chitosan extracted were the type and strength of acid and the homogenization of cell wall material prior to refluxing. Overall, weight average molecular weights of chitosan varied up to 8-fold in studies relating to fungal age, while up to 2-fold changes in molecular weight were affected by pH, medium type, and culture vessel size.

  13. Ketoconazole encapsulated in chitosan-gellan gum nanocomplexes exhibits prolonged antifungal activity.

    PubMed

    Kumar, Sandeep; Kaur, Pawan; Bernela, Manju; Rani, Ruma; Thakur, Rajesh

    2016-12-01

    The objective of the present study was to prepare ketoconazole loaded chitosan-gellan gum (CSGG) nanoparticles and to evaluate them for antifungal activity against Aspergillus niger. Ketoconazole loaded CSGG nanoparticles were prepared by electrostatic complexation technique using chitosan (CS) as cationic polymer and gellan gum (GG) as anionic polymer with ketoconazole as drug. It was observed that the effect of gellan gum on particle size was more pronounced in comparison to chitosan and increase in its concentration resulted in a significant increase in particle size but decrease in zeta potential. Whereas, increase in concentration of chitosan resulted in increase in zeta potential. The particle size and zeta potential of optimal formulation was 155.7±26.1nm and 32.1±2.8mV which obtained at concentration of chitosan (0.02% w/v) and gellan gum (0.01% w/v). On comparative evaluation, ketoconazole loaded CSGG nanoparticles showed significantly higher antifungal activity against Aspergillus niger than dummy CSGG nanoparticles (without drug) and drug individually.

  14. In vitro evaluation of osteoprotegerin in chitosan for potential bone defect applications

    PubMed Central

    Misran, Misni; Baharuddin, NA

    2016-01-01

    Background The receptor activator of nuclear factor kappa-B (RANK)/RANK ligand/osteoprotegerin (OPG) system plays a critical role in bone remodelling by regulating osteoclast formation and activity. OPG has been used systemically in the treatment of bone diseases. In searching for more effective and safer treatment for bone diseases, we investigated newly formulated OPG-chitosan complexes, which is prepared as a local application for its osteogenic potential to remediate bone defects. Methods We examined high, medium and low molecular weights of chitosan combined with OPG. The cytotoxicity of OPG in chitosan and its proliferation in vitro was evaluated using normal, human periodontal ligament (NHPL) fibroblasts in 2D and 3D cell culture. The cytotoxicity of these combinations was compared by measuring cell survival with a tetrazolium salt reduction (MTT) assay and AlamarBlue assay. The cellular morphological changes were observed under an inverted microscope. A propidium iodide and acridine orange double-staining assay was used to evaluate the morphology and quantify the viable and nonviable cells. The expression level of osteopontin and osteocalcin protein in treated normal human osteoblast cells was evaluated by using Western blot. Results The results demonstrated that OPG in combination with chitosan was non-toxic, and OPG combined with low molecular weight chitosan has the most significant effect on NHPL fibroblasts and stimulates proliferation of cells over the period of treatment. PMID:27635307

  15. Delivery of Splice Switching Oligonucleotides by Amphiphilic Chitosan-Based Nanoparticles.

    PubMed

    Moreno, Pedro M D; Santos, Joyce C; Gomes, Carla P; Varela-Moreira, Aida; Costa, Artur; Leiro, Victoria; Mansur, Herman; Pêgo, Ana P

    2016-02-01

    Splice switching oligonucleotides (SSOs) are a class of single-stranded antisense oligonucleotides (ssONs) being used as gene therapeutics and demonstrating great therapeutic potential. The availability of biodegradable and biocompatible delivery vectors that could improve delivery efficiencies, reduce dosage, and, in parallel, reduce toxicity concerns could be advantageous for clinical translation. In this work we explored the use of quaternized amphiphilic chitosan-based vectors in nanocomplex formation and delivery of splice switching oligonucleotides (SSO) into cells, while providing insights regarding cellular uptake of such complexes. Results show that the chitosan amphiphilic character is important when dealing with SSOs, greatly improving colloidal stability under serum conditions, as analyzed by dynamic light scattering, and enhancing cellular association. Nanocomplexes were found to follow an endolysosomal route with a long lysosome residence time. Conjugation of a hydrophobic moiety, stearic acid, to quaternized chitosan was a necessary condition to achieve transfection, as an unmodified quaternary chitosan was completely ineffective. We thus demonstrate that amphiphilic quaternized chitosan is a biomaterial that holds promise and warrants further development as a platform for SSO delivery strategies.

  16. Chitosan grafted low molecular weight polylactic acid for protein encapsulation and burst effect reduction.

    PubMed

    Di Martino, Antonio; Kucharczyk, Pavel; Zednik, Jiri; Sedlarik, Vladimir

    2015-12-30

    Chitosan and chitosan-grafted polylactic acid as a matrix for BSA encapsulation in a nanoparticle structure were prepared through a polyelectrolyte complexation method with dextran sulfate. Polylactic acid was synthetized via a polycondensation reaction using the non-metal-based initiator methanesulfonic acid and grafted to the chitosan backbone by a coupling reaction, with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide as the condensing agent. The effect of concentration of the polymer matrix utilized herein on particle diameter, ζ-potential, encapsulation efficiency, and the release kinetic of the model protein bovine serum albumin at differing pH levels was investigated. The influence of pH and ionic strength on the behavior of the nanoparticles prepared was also researched. Results showed that grafting polylactic acid to chitosan chains reduced the initial burst effect in the kinetics of BSA release from the structure of the nanoparticles. Furthermore, a rise in encapsulation efficiency of the bovine serum albumin and diminishment in nanoparticle diameter were observed due to chitosan modification. The results suggest that both polymers actually show appreciable encapsulation efficiency; and release rate of BSA. CS-g-PLA is more suitable than unmodified CS as a carrier for controlled protein delivery.

  17. In situ gelable interpenetrating double network hydrogel formulated from binary components: thiolated chitosan and oxidized dextran.

    PubMed

    Zhang, Hanwei; Qadeer, Aisha; Chen, Weiliam

    2011-05-09

    In situ gelable interpenetrating double-network hydrogels composed of thiolated chitosan (Chitosan-NAC) and oxidized dextran (Odex), completely devoid of potentially cytotoxic small molecule cross-linkers and that do not require complex maneuvers or catalysis, have been formulated. The interpenetrating network structure is created by Schiff base formations and disulfide bond inter-cross-linkings through exploiting the disparity of their reaction times. Compared with the autogelable thiolated chitosan hydrogels that typically require a relatively long time span for gelation to occur, the Odex/Chitosan-NAC composition solidifies rapidly and forms a well-developed 3D network in a short time span. Compared with typical hydrogels derived from natural materials, the Odex/Chitosan-NAC hydrogels are mechanically strong and resist degradation. The cytotoxicity potential of the hydrogels was determined by an in vitro viability assay using fibroblast as a model cell, and the results reveal that the hydrogels are noncytotoxic. In parallel, in vivo results from subdermal implantation in mice models demonstrate that this hydrogel is not only highly resistant to degradation but also induces very mild tissue response.

  18. Potential chitosan-coated alginate nanoparticles for ocular delivery of daptomycin.

    PubMed

    Costa, J R; Silva, N C; Sarmento, B; Pintado, M

    2015-06-01

    Daptomycin may offer an antibacterial alternative for the treatment of endophthalmitis caused by methicillin-resistant Staphylococcus aureus (MRSA) and other potential agents. In the present project, mucoadhesive chitosan-coated alginate (CS-ALG) nanoparticles are proposed as an effective delivery system for daptomycin permeation across ocular epithelia, with potential for the treatment of bacterial endophthalmitis. CS-ALG nanoparticles were prepared by ionotropic pre-gelation of an alginate core followed by chitosan polyelectrolyte complexation, and characterized regarding particle size, polydispersity, and zeta potential. The encapsulation efficiency was determined and antimicrobial activity was also tested after encapsulation of the antibiotic. Also, in vitro ocular permeability of free daptomycin and encapsulation into chitosan and CS-ALG nanoparticles was evaluated using ocular epithelial cell culture models. Formulated daptomycin-loaded CS-ALG nanoparticles were negatively charged, with a size range of 380-420 nm, suitable for ocular application. The encapsulation efficiency was between 79 and 92 %, with decreasing alginate:daptomycin mass ratios. The antibacterial activity of daptomycin against major microorganisms responsible for bacterial endophthalmitis was not affected by encapsulation into nanoparticles. Daptomycin permeability was up to 16 % (chitosan nanoparticles) and 9 % (CS-ALG nanoparticles) through corneal cell monolayer, and 18 % (chitosan nanoparticles) and 12 % (CS-ALG nanoparticles) for retinal cell monolayer after 4 h, demonstrating epithelial retention of the drug compared to free drug. The developed daptomycin-loaded CS-ALG nanoparticles seem to be an interesting and potential system for ocular daptomycin delivery and treatment of bacterial endophthalmitis.

  19. Development of chitosan-pullulan composite nanoparticles for nasal delivery of vaccines: in vivo studies.

    PubMed

    Cevher, Erdal; Salomon, Stefan K; Somavarapu, Satyanarayana; Brocchini, Steve; Alpar, H Oya

    2015-01-01

    Here, we aimed at developing chitosan/pullulan composite nanoparticles and testing their potential as novel systems for the nasal delivery of diphtheria toxoid (DT). All the chitosan derivatives [N-trimethyl (TMC), chloride and glutamate] and carboxymethyl pullulan (CMP) were synthesised and antigen-loaded composites were prepared by polyion complexation of chitosan and pullulan derivatives (particle size: 239-405 nm; surface charge: +18 and +27 mV). Their immunological effects after intranasal administration to mice were compared to intramuscular route. Composite nanoparticles induced higher levels of IgG responses than particles formed with chitosan derivative and antigen. Nasally administered TMC-pullulan composites showed higher DT serum IgG titre when compared with the other composites. Co-encapsulation of CpG ODN within TMC-CMP-DT nanoparticles resulted in a balanced Th1/Th2 response. TMC/pullulan composite nanoparticles also induced highest cytokine levels compared to those of chitosan salts. These findings demonstrated that TMC-CMP-DT composite nanoparticles are promising delivery system for nasal vaccination.

  20. In situ Gelable Interpenetrating Double Network Hydrogel Formulated from Binary Components: Thiolated Chitosan and Oxidized Dextran

    PubMed Central

    Zhang, Hanwei; Qadeer, Aisha; Chen, Weiliam

    2011-01-01

    In situ gelable interpenetrating double network hydrogels composed of thiolated chitosan (Chitosan-NAC) and oxidized dextran (Odex), completely devoid of potentially cytotoxic small molecule crosslinkers and do not require complex maneuvers or catalysis, have been formulated. The interpenetrating network structure is created by Schiff base formations and disulfide bond inter-crosslinkings through exploiting the disparity of their reaction times. Compare to the auto-gelable thiolated chitosan hydrogels that typically require a relatively long time span for gelation to occur, the Odex/Chitosan-NAC composition solidifies rapidly and forms a well-developed three-dimensional network in a short time span. Compare to typical hydrogels derived from natural materials, the Odex/Chitosan-NAC hydrogels are mechanically strong and resist degradation. The cytotoxicity potential of the hydrogels was determined by an in vitro viability assay using fibroblast as a model cell and the results reveal that the hydrogels are non-cytotoxic. In parallel, in vivo results from subdermal implantation in mice models demonstrate that this hydrogel is not only highly resistant to degradation but also induces very mild tissue response. PMID:21410248

  1. Spherical polystyrene-supported chitosan thin film of fast kinetics and high capacity for copper removal.

    PubMed

    Jiang, Wei; Chen, Xubin; Pan, Bingcai; Zhang, Quanxing; Teng, Long; Chen, Yufan; Liu, Lu

    2014-07-15

    In order to accelerate the kinetics and improve the utilization of the surface active groups of chitosan (CS) for heavy metal ion removal, sub-micron-sized polystyrene supported chitosan thin-film was synthesized by the electrostatic assembly method. Glutaraldehyde was used as cross-linking agent. Chitosan thin-film was well coated onto the surface of the polystyrene (PS) beads characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). Their adsorption toward Cu(II) ions was investigated as a function of solution pH, degree of cross-linking, equilibrium Cu(II) ions concentration and contact time. The maximum adsorptive capacity of PS-CS was 99.8 mg/g in the adsorption isotherm study. More attractively, the adsorption equilibrium was achieved in 10 min, which showed superior properties among similar adsorbents. Continuous adsorption-desorption cyclic results demonstrated that Cu(II)-loaded PS-CS can be effectively regenerated by a hydrochloric acid solution (HCl), and the regenerated composite beads could be employed for repeated use without significant capacity loss, indicating the good stability of the adsorbents. The XPS analysis confirmed that the adsorption process was due to surface complexes with atoms of chitosan. Generally, PS beads could be employed as a promising host to fabricate efficient composites that originated from chitosan or other bio-sorbents for environmental remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Chitosan-lipid nanoparticles (CS-LNPs): Application to siRNA delivery.

    PubMed

    Tezgel, Özgül; Szarpak-Jankowska, Anna; Arnould, Amandine; Auzély-Velty, Rachel; Texier, Isabelle

    2017-09-11

    To benefit from the biocompatibility of lipid nanoparticles associated with the transfection ability of chitosan, small chitosan lipid nanoparticles (CS-LNPs) dedicated to SiRNA delivery were formulated by an easy-to-implement one-step process. Formulations of CS-LNPs (lipid core stabilized by a shell comprising phospholipids/cationic lipids and hydrophobically modified chitosan) were optimized for their physico-chemical properties (size, zeta potential, colloidal stability) according to their shell composition. In particular, amphiphilic chitosan with various molecular weight and C12 degrees of substitution, and different phospholipids and cationic lipids (lecithin, DOTAP, DOPE) were included at the particle surface at different ratios. The ability of the particles for SiRNA complexation, NIH3T3 cell transfection, and ERK1 downregulation, were studied. Lipid nanoparticles formulated with 15,000g/mol 2% C12 substituted chitosan, DOTAP and DOPE, mediated 40% ERK1 downregulation efficiency, comparable to lipofectamine™ RNAimax, while displaying no cytotoxicity up to 500μg/mL. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Chitosan nanoparticle-based neuronal membrane sealing and neuroprotection following acrolein-induced cell injury.

    PubMed

    Cho, Youngnam; Shi, Riyi; Ben Borgens, Richard

    2010-01-29

    The highly reactive aldehyde acrolein is a very potent endogenous toxin with a long half-life. Acrolein is produced within cells after insult, and is a central player in slow and progressive "secondary injury" cascades. Indeed, acrolein-biomolecule complexes formed by cross-linking with proteins and DNA are associated with a number of pathologies, especially central nervous system (CNS) trauma and neurodegenerative diseases. Hydralazine is capable of inhibiting or reducing acrolein-induced damage. However, since hydralazine's principle activity is to reduce blood pressure as a common anti-hypertension drug, the possible problems encountered when applied to hypotensive trauma victims have led us to explore alternative approaches. This study aims to evaluate such an alternative - a chitosan nanoparticle-based therapeutic system. Hydralazine-loaded chitosan nanoparticles were prepared using different types of polyanions and characterized for particle size, morphology, zeta potential value, and the efficiency of hydralazine entrapment and release. Hydralazine-loaded chitosan nanoparticles ranged in size from 300 nm to 350 nm in diameter, and with a tunable, or adjustable, surface charge. We evaluated the utility of chitosan nanoparticles with an in-vitro model of acrolein-mediated cell injury using PC -12 cells. The particles effectively, and statistically, reduced damage to membrane integrity, secondary oxidative stress, and lipid peroxidation. This study suggests that a chitosan nanoparticle-based therapy to interfere with "secondary" injury may be possible.

  4. Multichannel mould processing of 3D structures from microporous coralline hydroxyapatite granules and chitosan support materials for guided tissue regeneration/engineering.

    PubMed

    Baran, E T; Tuzlakoglu, K; Salgado, A J; Reis, R L

    2004-02-01

    A three-dimensional composite material was produced from microporous coralline origin hydroxyapatite (HA) microgranules, chitosan fibers and chitosan membrane. Cylindrical HA microgranules were oriented along channel direction within multichannel mould space and aligned particles were supported with fibers and a chitosan membrane. The positive replica of mould channels was clasp fixed to produce thicker scaffolds. Light microphotographs of the developed complex structure showed good adhesion between the HA particles, the fibers and the supporting membrane. The composite material showed 88% (w/w) swelling in one hour and preserved the complex structure of the original material upon long-term incubation in physiological medium. MEM extract test of HA chitosan complex showed no cell growth inhibition and cell viability assay (MTS) indicated over 90% cell viability.

  5. Use of artificial neural networks to examine parameters affecting the immobilization of streptokinase in chitosan.

    PubMed

    Modaresi, Seyed Mohamad Sadegh; Faramarzi, Mohammad Ali; Soltani, Arash; Baharifar, Hadi; Amani, Amir

    2014-01-01

    Streptokinase is a potent fibrinolytic agent which is widely used in treatment of deep vein thrombosis (DVT), pulmonary embolism (PE) and acute myocardial infarction (MI). Major limitation of this enzyme is its short biological half-life in the blood stream. Our previous report showed that complexing streptokinase with chitosan could be a solution to overcome this limitation. The aim of this research was to establish an artificial neural networks (ANNs) model for identifying main factors influencing the loading efficiency of streptokinase, as an essential parameter determining efficacy of the enzyme. Three variables, namely, chitosan concentration, buffer pH and enzyme concentration were considered as input values and the loading efficiency was used as output. Subsequently, the experimental data were modeled and the model was validated against a set of unseen data. The developed model indicated chitosan concentration as probably the most important factor, having reverse effect on the loading efficiency.

  6. Use of Artificial Neural Networks to Examine Parameters Affecting the Immobilization of Streptokinase in Chitosan

    PubMed Central

    Modaresi, Seyed Mohamad Sadegh; Faramarzi, Mohammad Ali; Soltani, Arash; Baharifar, Hadi; Amani, Amir

    2014-01-01

    Streptokinase is a potent fibrinolytic agent which is widely used in treatment of deep vein thrombosis (DVT), pulmonary embolism (PE) and acute myocardial infarction (MI). Major limitation of this enzyme is its short biological half-life in the blood stream. Our previous report showed that complexing streptokinase with chitosan could be a solution to overcome this limitation. The aim of this research was to establish an artificial neural networks (ANNs) model for identifying main factors influencing the loading efficiency of streptokinase, as an essential parameter determining efficacy of the enzyme. Three variables, namely, chitosan concentration, buffer pH and enzyme concentration were considered as input values and the loading efficiency was used as output. Subsequently, the experimental data were modeled and the model was validated against a set of unseen data. The developed model indicated chitosan concentration as probably the most important factor, having reverse effect on the loading efficiency. PMID:25587327

  7. Effect of O3 and O3/H2O2 on algae harvesting using chitosan.

    PubMed

    Pranowo, R; Lee, D J; Liu, J C; Chang, J S

    2013-01-01

    We examined the effects of pre-oxidation using ozone (O3) and a combination of O3 and hydrogen peroxide (O3/H2O2) on algae suspensions and their harvesting. Inactivation of algae cells, release of intracellular organic matter (IOM), mineralization of extracellular organic matter (EOM), and changes in molecular weight distribution of EOM were found after pre-oxidation. Enhanced separation efficiency of turbidity, dissolved organic carbon (DOC), protein, and polysaccharide using chitosan and polyaluminum chloride (PACl) was found after pre-oxidation, especially when algae cells were subject to O3/H2O2. Chitosan showed higher efficiency than PACl. Judging from the remarkable increase in floc size, it was proposed that released IOM formed complexes with cationic chitosan and resulted in enhanced dual flocculation and facilitated algae separation.

  8. Insights into and relative effect of chitosan-H, chitosan-H-propolis, chitosan-H-propolis-nystatin and chitosan-H-nystatin on dentine bond strength

    PubMed Central

    Perchyonok, Victoria Tamara; Zhang, Shengmiao; Grobler, Sias R.; Oberholzer, Theunis G.

    2013-01-01

    Objective: The purpose of the study was to design and evaluate novel functional chitosan hydrogels (chitosan-H-propolis, chitosan-H-propolis-nystatin and chitosan-H-nystatin) by using the chitosan-H polymer as “dual function restorative materials”. Materials and Methods: The nystatin/antioxidant carrier gel was prepared by dispersion of the corresponding component in glycerol and 3% acetic acid with 5% chitosan gelling agent was then added to the dispersion with continuous mixing. The natural bio-adhesive functionalized chitosan hydrogels were combined with built in drug delivery system and bio-actives such as propolis in order to increase the dentin bond strength capacity and maintain therapeutic properties of the alternative drug delivery system. The surface morphology, release behaviors (physiological pH and also in acidic conditions), stability of nystatin:antioxidant:chitosan and the effect of the hydrogels on the shear bond strength of dentin were also evaluated. Statistical Analysis Used: Non-parametric ANOVA test was used to asses significance of higher shear bond values than dentine treated or not treated with phosphoric acid. Results: The release of both nystatin and propolis confer the added benefit of dual action of a functional therapeutic delivery when comparing the newly designed chitosan-based hydrogel restorative materials to commercially available nystatin alone. Neither the release of nystatin nor the antioxidant stability was affected by storage. Chitosan-H, chitosan-propolis, chitosan-nystatin and chitosan-nystatin-propolis treated dentine gives significantly (P < 0.05) higher shear bond values (P < 0.05) than dentine treated or not treated with phosphoric acid. Conclusion: The added benefits of their unique functionality involve increased dentin adhesive bond strengths (after 24 h and after 6 months) and positive influence on the nystatin release. Nystatin was a model therapeutic agent, evaluating the concept of using functional materials

  9. Synthesis of raloxifene-chitosan conjugate: A novel chitosan derivative as a potential targeting vehicle.

    PubMed

    Samadi, Fatemeh Yazdi; Mohammadi, Zohreh; Yousefi, Maryam; Majdejabbari, Sara

    2016-01-01

    Chitosan is a biocompatible, non-toxic and biodegradable biopolymer. Due to the presence of functional groups on its surface, it can be modified and used as a carrier in targeted drug/gene delivery systems. In this study, raloxifene (a selective estrogen receptor ligand) was conjugated to chitosan using different methods. The conjugates were investigated by means of FTIR, TGA and physical properties assessments. Cell viability was evaluated by XTT assay. FTIR and TGA results confirmed that the conjugation between chitosan and raloxifene occurred more efficiently when trimethyl chitosan in the presence of triethylamine and excess amount of linker was used. XTT assay on MCF-7 cell line illustrated that more than 80% of cells were viable after 24h exposure to selected molecules. These findings confirm that the conjugation of raloxifene-chitosan can occur successfully using special synthesis condition and this novel chitosan derivative can be introduced as a potential drug/gene targeting agent.

  10. The effect of chitosan concentration on the electrical property of chitosan-blended cellulose electroactive paper

    NASA Astrophysics Data System (ADS)

    Jang, Sang-Dong; Kim, Joo-Hyung; Zhijiang, Cai; Kim, Jaehwan

    2009-01-01

    We studied the effect of chitosan blending on the electrical property of chitosan-blended cellulose electroactive paper (EAPap) under different humidity conditions. As the chitosan blending ratio increased, the real part of the dielectric constant of chitosan-blended cellulose EAPap increased while the dielectric loss factor decreased. From the curve fitting of the measured data using an electrode polarization model, it was found that increasing the chitosan ratio in the EAPap might promote a decrease in the relaxation time of the EAPap, resulting in an increase of the ion mobility and dc conductivity. Over 30% of the chitosan blending ratio, a gradual increment of the ion mobility of the EAPap was observed at 40% relative humidity, while a quadratic increment of the mobility was found at 60% relative humidity condition. This kind of ion-mobility-enhanced cellulose EAPap can be used not only for bending actuators but also for medical applications such as blood clotting patches.

  11. Chitosan Hydrogel Structure Modulated by Metal Ions

    NASA Astrophysics Data System (ADS)

    Nie, Jingyi; Wang, Zhengke; Hu, Qiaoling

    2016-10-01

    As one of the most important polysaccharide, chitosan (CS) has generated a great deal of interest for its desirable properties and wide applications. In the utilization of CS materials, hydrogel is a major and vital branch. CS has the ability to coordinate with many metal ions by a chelation mechanism. While most researchers focused on the applications of complexes between CS and metal ions, the complexes can also influence gelation process and structure of CS hydrogel. In the present work, such influence was studied with different metal ions, revealing two different kinds of mechanisms. Strong affinity between CS and metal ions leads to structural transition from orientation to multi-layers, while weak affinity leads to composite gel with in-situ formed inorganic particles. The study gave a better understanding of the gelation mechanism and provided strategies for the modulation of hydrogel morphology, which benefited the design of new CS-based materials with hierarchical structure and facilitated the utilization of polysaccharide resources.

  12. Chitosan Hydrogel Structure Modulated by Metal Ions

    PubMed Central

    Nie, Jingyi; Wang, Zhengke; Hu, Qiaoling

    2016-01-01

    As one of the most important polysaccharide, chitosan (CS) has generated a great deal of interest for its desirable properties and wide applications. In the utilization of CS materials, hydrogel is a major and vital branch. CS has the ability to coordinate with many metal ions by a chelation mechanism. While most researchers focused on the applications of complexes between CS and metal ions, the complexes can also influence gelation process and structure of CS hydrogel. In the present work, such influence was studied with different metal ions, revealing two different kinds of mechanisms. Strong affinity between CS and metal ions leads to structural transition from orientation to multi-layers, while weak affinity leads to composite gel with in-situ formed inorganic particles. The study gave a better understanding of the gelation mechanism and provided strategies for the modulation of hydrogel morphology, which benefited the design of new CS-based materials with hierarchical structure and facilitated the utilization of polysaccharide resources. PMID:27777398

  13. Adsorption of selenite and selenate by nanocrystalline aluminum oxide, neat and impregnated in chitosan beads.

    PubMed

    Yamani, Jamila S; Lounsbury, Amanda W; Zimmerman, Julie B

    2014-03-01

    Nanocrystalline metal oxide impregnated chitosan beads (MICB) were successfully developed with nanocrystalline aluminum oxide (n-Al2O3) to form n-Al2O3 impregnated chitosan beads (AICB). AICB were able to simultaneously adsorb inorganic aqueous selenite and selenate more effectively than n-Al2O3 or chitosan alone. For completeness, adsorption performance was also compared to n-TiO2, a widely studied adsorbent for selenium, and n-TiO2 impregnated chitosan beads (TICB). For the selenite system, n-Al2O3 was the primary active adsorbent responsible for removal as chitosan has a low affinity for selenite. For selenate, however, chitosan was the primary active adsorbent. The association constants for the adsorbent/adsorbate complexes and the relative amounts in which they are present supported this hypothesis. The association constants for selenate binding on n-Al2O3 and chitosan were 1.215 × 10(-2) and 3.048 × 10(-3), respectively, and the association constants for selenite binding on n-Al2O3 and chitosan were 1.349 × 10(-2) and 1.990 × 10(-4), respectively. For systems with coexisting selenite and selenate, AICB is potentially the most robust option as it maintained the most consistent performance regardless of fractionation of the selenium species. Kinetic studies and equilibrium isotherms were completed and effectively modeled using pseudo-second order kinetics and Langmuir adsorption theory, making it the first comprehensive systematic study of neat n-Al2O3 and AICB for selenium adsorption. pH significantly impacted adsorption due to changes in the adsorbent surface charge; increasing pH corresponded with decreasing adsorbent performance, beginning at approximately pH 6.5-7 for AICB. The trend in performance due to the effect of pH indicated that selenate binds to the amine group in chitosan, as suggested by other studies. In addition, increasing background sulfate concentration was found to negatively impact adsorption efficacy for both selenite, and

  14. Evaluation of antibacterial efficiency of chitosan and chitosan nanoparticles on cariogenic streptococci: an in vitro study

    PubMed Central

    Aliasghari, Azam; Rabbani Khorasgani, Mohammad; Vaezifar, Sedigheh; Rahimi, Fateh; Younesi, Habibollah; Khoroushi, Maryam

    2016-01-01

    Background and Objectives: The most prevalent and worldwide oral disease is dental caries that affects a significant proportion of the world population. There are some classical approaches for control, prevention and treatment of this pathologic condition; however, the results are still not completely successful. Therefore new methods are needed for better management of this important challenge. Chitosan is a natural and non-toxic polysaccharide with many biological applications, particularly as an antimicrobial agent. Chitosan nanoparticle is a bioactive and environment friendly material with unique physicochemical properties. The aim of the present study was to investigate the antimicrobial effect of chitosan and nano-chitosan on the most important cariogenic streptococci. Materials and Methods: For evaluation of antimicrobial effect of chitosan and nano-chitosan against oral streptococci broth micro-dilution method was carried out for four bacterial species; Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguis and Streptococcus salivarius. Also the effect of these materials on adhesion of above bacteria was evaluated. One-way ANOVA and post hoc Tukey test were used for statistical analysis. Results: The MICs of chitosan for S. mutans, S. sanguis, S. salivarius and S. sobrinus were 1.25, 1.25, 0.625 and 0.625 mg/mL, respectively. The MIC of chitosan nanoparticle for S. mutans, S. salivarius and S. sobrinus was 0.625 mg/mL and for S. sanguis was 0.312 mg/mL. Chitosan and chitosan nanoparticles at a concentration of 5 mg/mL also reduced biofilm formation of S. mutans up to 92.5% and 93.4%, respectively. Conclusion: The results of this study supported the use of chitosan and chitosan nanoparticles as antimicrobial agents against cariogenic Streptococci. PMID:27307974

  15. Chitosan-mediated siRNA delivery in vitro: effect of polymer molecular weight, concentration and salt forms.

    PubMed

    Techaarpornkul, Sunee; Wongkupasert, Sirirat; Opanasopit, Praneet; Apirakaramwong, Auayporn; Nunthanid, Jurairat; Ruktanonchai, Uracha

    2010-03-01

    The aim of this study was to investigate chitosan/siRNA complexes formulated with various chitosan salts (CS) including chitosan aspartate (CS-Asp), chitosan glutamate (CS-Glu), chitosan acetate (CS-Ac), and chitosan hydrochloride (CS-HCl) for in vitro siRNA delivery into stable and constitutive enhanced green fluorescent protein (EGFP)-expressing HeLa cells. The CS/siRNA complexes were characterized by 2% agarose gel electrophoresis and investigated for their transfection efficiency in stable and constitutive EGFP-expressing HeLa cells. The cytotoxicity of the complexes was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The formation of complexes CS/siRNA is mainly dependent on the weight ratio, whereas salt form and molecular weight has less effect. The particle sizes of the complete complexes were in the range of 270-373 nm except the complete complex of CS-Ac, with a slightly positive charge of less than 2 mV. The ability of CS to transfer functionally active siRNA into cell culture is mainly dependent on the weight ratio and molecular weight of CS whereas salt form of CS has less effect. The high gene-silencing efficiency was observed with low MW of CS (20 kDa) and high weight ratio of 32. Over 80% average cell viabilities were observed for CS/siRNA complexes in all weight ratios comparison to untreated cells. This study suggests CS salts have the potential to be used as safe siRNA delivery vectors.

  16. Coloration of cotton fibers using nano chitosan.

    PubMed

    Wijesena, Ruchira N; Tissera, Nadeeka D; de Silva, K M Nalin

    2015-12-10

    A method of coloration of cotton fabrics with nano chitosan is proposed. Nano chitosan were prepared using crab shell chitin nanofibers through alkaline deacetylation process. Average nano fiber diameters of nano chitosan were 18 nm to 35 nm and the lengths were in the range of 0.2-1.3 μm according to the atomic force microscope study. The degree of deacetylation of the material was found to be 97.3%. The prepared nano chitosan dyed using acid blue 25 (2-anthraquinonesulfonic acid) and used as the coloration agent for cotton fibers. Simple wet immersion method was used to color the cotton fabrics by nano chitosan dispersion followed by acid vapor treatment. Scanning electron microscope and atomic force microscope study of the treated cotton fiber revealed that the nano chitosan were consistently deposited on the cotton fiber surface and transformed in to a thin polymer layer upon the acid vapor treatment. The color strength of the dyed fabrics could be changed by changing the concentration of dyed nano chitosan dispersion.

  17. Green synthesis approach: extraction of chitosan from fungus mycelia.

    PubMed

    Dhillon, Gurpreet Singh; Kaur, Surinder; Brar, Satinder Kaur; Verma, Mausam

    2013-12-01

    Chitosan, copolymer of glucosamine and N-acetyl glucosamine is mainly derived from chitin, which is present in cell walls of crustaceans and some other microorganisms, such as fungi. Chitosan is emerging as an important biopolymer having a broad range of applications in different fields. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal sources. The methods used for extraction of chitosan are laden with many disadvantages. Alternative options of producing chitosan from fungal biomass exist, in fact with superior physico-chemical properties. Researchers around the globe are attempting to commercialize chitosan production and extraction from fungal sources. Chitosan extracted from fungal sources has the potential to completely replace crustacean-derived chitosan. In this context, the present review discusses the potential of fungal biomass resulting from various biotechnological industries or grown on negative/low cost agricultural and industrial wastes and their by-products as an inexpensive source of chitosan. Biologically derived fungal chitosan offers promising advantages over the chitosan obtained from crustacean shells with respect to different physico-chemical attributes. The different aspects of fungal chitosan extraction methods and various parameters having an effect on the yield of chitosan are discussed in detail. This review also deals with essential attributes of chitosan for high value-added applications in different fields.

  18. Borate cross-linking chitosan/graphene oxide films: Toward the simultaneous enhancement of gases barrier and mechanical properties

    NASA Astrophysics Data System (ADS)

    Yan, Ning; Capezzuto, Filomena; Buonocore, Giovanna G.; Tescione, Fabiana; Lavorgna, Marino; Xia, Hesheng; Ambrosio, Luigi

    2015-12-01

    Borate adducts, originated from hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan (CS) and graphene oxide (GO) nanosheets for the production of innovative composite sustainable materials. CS/GO film consisting of 10wt% borax and 1wt% GO exhibits a significant improvement of both toughness and oxygen barrier properties in comparison to pristine chitosan. In particular the tensile strength increases by about 100% and 150% after thermal annealing of samples at 90°C for 50min whereas the oxygen permeability reduces of about 90% compared to pristine chitosan. The enhancement of both mechanical and barrier properties is ascribed to the formation of a resistant network due to the chemical crosslinking, including borate orthoester bonds and hydroxyl moieties complexes, formed among borate ions, chitosan, and GO nanoplatelets. The crosslinked graphene-based chitosan material with its enhanced mechanical and barrier properties may significantly broad the range of applications of chitosan based-materials which presently are very limited and addressed only to packaging.

  19. Synthesis and characterization of electrospun polyvinyl alcohol nanofibrous scaffolds modified by blending with chitosan for neural tissue engineering

    PubMed Central

    Alhosseini, Sanaz Naghavi; Moztarzadeh, Fathollah; Mozafari, Masoud; Asgari, Shadnaz; Dodel, Masumeh; Samadikuchaksaraei, Ali; Kargozar, Saeid; Jalali, Newsha

    2012-01-01

    Among several attempts to integrate tissue engineering concepts into strategies to repair different parts of the human body, neuronal repair stands as a challenging area due to the complexity of the structure and function of the nervous system and the low efficiency of conventional repair approaches. Herein, electrospun polyvinyl alcohol (PVA)/chitosan nano-fibrous scaffolds have been synthesized with large pore sizes as potential matrices for nervous tissue engineering and repair. PVA fibers were modified through blending with chitosan and porosity of scaffolds was measured at various levels of their depth through an image analysis method. In addition, the structural, physicochemical, biodegradability, and swelling of the chitosan nanofibrous scaffolds were evaluated. The chitosan-containing scaffolds were used for in vitro cell culture in contact with PC12 nerve cells, and they were found to exhibit the most balanced properties to meet the basic required specifications for nerve cells. It could be concluded that addition of chitosan to the PVA scaffolds enhances viability and proliferation of nerve cells, which increases the biocompatibility of the scaffolds. In fact, addition of a small percentage of chitosan to the PVA scaffolds proved to be a promising approach for synthesis of a neural-friendly polymeric blend. PMID:22275820

  20. In vitro evaluation of anti-calcification and anti-coagulation on sulfonated chitosan and carrageenan surfaces.

    PubMed

    Campelo, Clayton Souza; Lima, Luana Dias; Rebêlo, Luciana Magalhães; Mantovani, Diego; Beppu, Marisa Masumi; Vieira, Rodrigo Silveira

    2016-02-01

    In recent years, great effort has been devoted to the development of biomaterials that come into contact with blood. The surfaces of these materials need to be of suitable mechanical strength, and present anti-thrombogenic and anti-calcification properties. Chitosan is a natural polymer that has attracted attention due to its potential to act as a biomaterial. However, chitosan contains amino groups in its structure that may promote thrombogenesis and calcification. A strategy to reduce these properties constitutes the introduction of sulfonate groups (R-SO3-) in the chitosan chain. Another interesting biopolymer with similar characteristics to those of heparin is carrageenan, which has sulfate groups in its structure. As such, we evaluated “in vitro” calcification and thrombogenic processes on surfaces of pristine and sulfonated chitosan and on polyelectrolyte complexes (PEC) of chitosan and carrageenan. Results indicate that PEC demonstrate significant reductions in calcification and thrombogenic potential, probably due to the presence of sulfonate groups in both the carrageenan and treated chitosan.

  1. Synthesis and characterization of electrospun polyvinyl alcohol nanofibrous scaffolds modified by blending with chitosan for neural tissue engineering.

    PubMed

    Alhosseini, Sanaz Naghavi; Moztarzadeh, Fathollah; Mozafari, Masoud; Asgari, Shadnaz; Dodel, Masumeh; Samadikuchaksaraei, Ali; Kargozar, Saeid; Jalali, Newsha

    2012-01-01

    Among several attempts to integrate tissue engineering concepts into strategies to repair different parts of the human body, neuronal repair stands as a challenging area due to the complexity of the structure and function of the nervous system and the low efficiency of conventional repair approaches. Herein, electrospun polyvinyl alcohol (PVA)/chitosan nanofibrous scaffolds have been synthesized with large pore sizes as potential matrices for nervous tissue engineering and repair. PVA fibers were modified through blending with chitosan and porosity of scaffolds was measured at various levels of their depth through an image analysis method. In addition, the structural, physicochemical, biodegradability, and swelling of the chitosan nanofibrous scaffolds were evaluated. The chitosan-containing scaffolds were used for in vitro cell culture in contact with PC12 nerve cells, and they were found to exhibit the most balanced properties to meet the basic required specifications for nerve cells. It could be concluded that addition of chitosan to the PVA scaffolds enhances viability and proliferation of nerve cells, which increases the biocompatibility of the scaffolds. In fact, addition of a small percentage of chitosan to the PVA scaffolds proved to be a promising approach for synthesis of a neural-friendly polymeric blend.

  2. Hyaluronic acid-coated chitosan nanoparticles: molecular weight-dependent effects on morphology and hyaluronic acid presentation.

    PubMed

    Almalik, Abdulaziz; Donno, Roberto; Cadman, Christopher J; Cellesi, Francesco; Day, Philip J; Tirelli, Nicola

    2013-12-28

    Chitosan nanoparticles are popular carriers for the delivery of macromolecular payloads, e.g. nucleic acids. In this study, nanoparticles were prepared via complexation with triphosphate (TPP) anions and were successively coated with hyaluronic acid (HA). Key variables of the preparative process (e.g. chitosan and HA molecular weight) were optimised in view of the maximisation of loading with DNA, of the Zeta potential and of the dimensional stability, and the resulting particles showed excellent storage stability. We have focused on the influence of chitosan molecular weight on nanoparticle properties. Larger molecular weight increased their porosity (=decreased cross-link density), and this caused also larger dimensional changes in response to variations in osmotic pressure or upon drying. The dependency of nanoparticle porosity on chitosan molecular weight had a profound effect on the adsorption of HA on the nanoparticles; HA was apparently able to penetrate deeply into the more porous high molecular weight (684 kDa) chitosan nanoparticles, while it formed a corona around those composed of more densely cross-linked low molecular weight (25 kDa) chitosan. Atomic Force Microscopy (AFM) allowed not only to highlight the presence of this corona, but also to estimate its apparent thickness to about 20-30 nm (in a dry state). The different morphology has a significant effect on the way HA is presented to biomolecules, and this has specific relevance in relation to interactions with HA receptors (e.g. CD44) that influence kinetics and mechanism of nanoparticle uptake. Finally, it is worth to mention that chitosan molecular weight did not appear to greatly affect the efficiency of nanoparticle loading with DNA, but significantly influenced its chitosanase-triggered release, with high molecular chitosan nanoparticles seemingly more prone to degradation by this enzyme.

  3. Electrospun antibacterial chitosan-based fibers.

    PubMed

    Ignatova, Milena; Manolova, Nevena; Rashkov, Iliya

    2013-07-01

    Chitosan is non-toxic, biocompatible, and biodegradable polysaccharide from renewable resources, known to have inherent antibacterial activity, which is mainly due to its polycationic nature. The combining of all assets of chitosan and its derivatives with the unique properties of electrospun nanofibrous materials is a powerful strategy to prepare new materials that can find variety of biomedical applications. In this article the most recent studies on different approaches for preparation of antibacterial fibrous materials from chitosan and its derivatives such as electrospinning, coating, and electrospinning-electrospraying, loading of drugs or bioactive nanoparticles are summarized.

  4. Needleless Electrospinning of Pure and Blended Chitosan

    NASA Astrophysics Data System (ADS)

    Grimmelsmann, Nils; Homburg, Sarah Vanessa; Ehrmann, Andrea

    2017-08-01

    Chitosan is a biopolymer with bactericidal, fungicidal, hemostatic and other interesting properties. It can be used, e.g., in medical products, as a filter medium, in biotechnological purposes etc. For these possible applications, nanofiber mats with a large inner surface will be most efficient. This is why in a recent project, the electrospinning properties of pure chitosan as well as chitosan blended with poly(ethylene oxide) were investigated. Using a needleless nanospinning process, the technology under examination can be upscaled from lab to industrial scale, enabling direct transfer of the gained experiences to the intended application.

  5. Oxidation-mediated chitosan as additives for creation of chitosan aerogels with diverse three-dimensional interconnected skeletons

    NASA Astrophysics Data System (ADS)

    Zhang, Sizhao; Feng, Jian; Feng, Junzong; Jiang, Yonggang

    2017-02-01

    Naturally occurring polymer-based aerogels have myriad practical utilizations due to environmentally benign and fruitful resources. However, engineering morphology-controllable biomass aerogels still represents a great challenge. Here we present a facile solution to synthesize chitosan aerogels having distinguished textures by reacting oxidized chitosan with formaldehyde and chitosan sol. In more detail, chitosan was chemically oxidized using two types of oxidation agents such as ammonium persulphate (SPD) and sodium periodate (APS) to obtain corresponding oxidized chitosan, subsequently cross-linked with chitosan solution containing formaldehyde to harvest SPD-oxidized chitosan aerogels (SCAs) and APS-SPD-oxidized ones (ASCAs) after aging, solvent exchange and supercritical drying processes. We found that the morphologies of as-prepared chitosan aerogels are strongly dependent upon the oxidation pattern towards chitosan. The structural textures of SCAs and ASCAs appear nanoflake-like and nanofiber-like structures, which may be related to spatial freedom of active groups located in chitosan. Selected area electron diffraction analysis reveals that the crystalline properties of chitosan aerogels generally appear the serious deterioration comparing to raw chitosan owing to their interconnected skeletal structure formation. The occurrence of characteristic groups displays cross-linked chain construction by using chemical state measurements such as FT-IR and XPS. Further, a plausible mechanism for controlling morphology of chitosan aerogels is also established. This new family of method for creation of chitosan aerogels may open up a perspective for biomass aerogels with controllable textures.

  6. Chitosan as a starting material for wound healing applications.

    PubMed

    Patrulea, V; Ostafe, V; Borchard, G; Jordan, O

    2015-11-01

    Chitosan and its derivatives have attracted great attention due to their properties beneficial for application to wound healing. The main focus of the present review is to summarize studies involving chitosan and its derivatives, especially N,N,N-trimethyl-chitosan (TMC), N,O-carboxymethyl-chitosan (CMC) and O-carboxymethyl-N,N,N-trimethyl-chitosan (CMTMC), used to accelerate wound healing. Moreover, formulation strategies for chitosan and its derivatives, as well as their in vitro, in vivo and clinical applications in wound healing are described.

  7. Chitosan nanocapsules: Effect of chitosan molecular weight and acetylation degree on electrokinetic behaviour and colloidal stability.

    PubMed

    Santander-Ortega, M J; Peula-García, J M; Goycoolea, F M; Ortega-Vinuesa, J L

    2011-02-01

    In recent years, chitosan nanocapsules have shown promising results as carriers for oral drug or peptide delivery. The success in their applicability strongly depends on the stability of these colloidal systems passing through the digestive tract. In gastric fluids, clear stability comes from the high surface charge density of the chitosan shell, which is completely charged at acidic pH values. However, in the intestinal fluid (where the pH is almost neutral) the effective charge of these nanocapsules approaches zero, and the electrostatic forces cannot provide any stabilization. Despite the lack of surface charge, chitosan nanocapsules remain stable in simulated intestinal fluids. Recently, we have demonstrated that this anomalous stability (at zero charge) is owed to short-range repulsive forces that appear between hydrophilic particles when immersed in saline media. The present work examines the influence of the chitosan hydrophobicity, as well as molecular weight, in the stability of different chitosan nanocapsules. A study has been made of the size, polydispersity, electrophoretic mobility, and colloidal stability of eight core-shell nanocapsule systems, in which the chitosan-shell properties have been modified using low-molecular-weight (LMW) and high-molecular-weight (HMW) chitosan chains having different degrees of acetylation (DA). With regard to the stability mediated by repulsive hydration forces, the LMW chitosan provided the best results. In addition, contrary to initial expectations, greater stability (also mediated by hydration forces) was found in the samples formed with chitosan chains of high DA values (i.e. with less hydrophilic chitosan). Finally, a theoretical treatment was also tested to quantify the hydrophilicity of the chitosan shells. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Engineering Tenofovir Loaded Chitosan Nanoparticles

    PubMed Central

    Meng, Jianing; Sturgis, Timothy F.; Youan, Bi-Botti C.

    2011-01-01

    The objective of this study was to engineer a model anti-HIV microbicide (Tenofovir) loaded chitosan based nanoparticles (NPs). Box-Behnken design allowed to assess the influence of formulation variables on the size of NPs and drug encapsulation efficiency (EE%) that were analyzed by dynamic light scattering and UV spectroscopy, respectively. The effect of the NPs on vaginal epithelial cells and Lactobacillus crispatus viability and their mucoadhesion to porcine vaginal tissue were assessed by cytotoxicity assays and fluorimetry, respectively. In the optimal aqueous conditions, the EE% and NPs size was 5.83% and 207.97nm, respectively. With 50% (v/v) ethanol/water as alternative solvent, these two responses increased to 20% and 602 nm, respectively. Drug release from medium (281 nm) and large size (602 nm)-sized NPs fitted the Higuchi (r2=0.991) and first-order release (r2=0.999) models, respectively. These NPs were not cytotoxic to both the vaginal epithelial cell line and Lactobacillus for 48 hours. When the diameter of the NPs decreased from 900 nm to 188 nm, the mucoadhesion increased from 6% to 12%. However, the combinatorial effect of EE% × mucoadhesion for larger size NPs was the highest. Overall, large-size, microbicide loaded chitosan NPs appeared to be promising nanomedicines for the prevention of HIV transmission. PMID:21704704

  9. Hexavalent chromium removal in contaminated water using reticulated chitosan micro/nanoparticles from seafood processing wastes.

    PubMed

    Dima, Jimena Bernadette; Sequeiros, Cynthia; Zaritzky, Noemi E

    2015-12-01

    Chitosan particles (CH) were obtained from seafood processing wastes (shrimp shells) and physicochemically characterized; deacetylation degree of CH was measured by Infrared Spectroscopy (FTIR) and potentiometric titration; polymer molecular weight was determined by intrinsic viscosity measurements. Reticulated micro/nanoparticles of chitosan (MCH) with an average diameter close to 100nm were synthesized by ionic gelation of chitosan using tripolyphosphate (TPP), and characterized by SEM, size distribution and Zeta-potential. Detoxification capacities of CH and MCH were tested analyzing the removal of hexavalent chromium Cr(VI) from contaminated water, at different initial chromium concentrations. The effect of pH on adsorption capacity of CH and MCH was experimentally determined and analyzed considering the Cr(VI) stable complexes (anions) formed, the presence of protonated groups in chitosan particles and the addition of the reticulating agent (TPP). Chitosan crosslinking was necessary to adsorb Cr(VI) at pH<2 due to the instability of CH particles in acid media. Langmuir isotherm described better than Freundlich and Temkin equations the equilibrium adsorption data. Pseudo-second order rate provided the best fitting to the kinetic data in comparison to pseudo-first order and Elovich equations. Chemical analysis to determine the oxidation state of the adsorbed Cr, showed that Cr(VI) was adsorbed on CH particles without further reduction; in contrast Cr(VI) removed from the solution was reduced and bound to the MCH as Cr(III). The reduction of toxic Cr(VI) to the less or nontoxic Cr(III) by the reticulated chitosan micro/nanoparticles can be considered a very efficient detoxification technique for the treatment of Cr(VI) contaminated water. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Mechanical Properties, Cytocompatibility and Manufacturability of Chitosan:PEGDA Hybrid-Gel Scaffolds by Stereolithography.

    PubMed

    Morris, Viola B; Nimbalkar, Siddharth; Younesi, Mousa; McClellan, Phillip; Akkus, Ozan

    2017-01-01

    Extracellular matrix mimetic hydrogels which hybridize synthetic and natural polymers offer molecularly-tailored, bioactive properties and tunable mechanical strength. In addition, 3D bioprinting by stereolithography allows fabrication of internal pores and defined macroscopic shapes. In this study, we formulated a hybrid biocompatible resin using natural and synthetic polymers (chitosan and polyethylene glycol diacrylate (PEGDA), respectively) by controlling molecular weight of chitosan, feed-ratios, and photo-initiator concentration. Ear-shaped, hybrid scaffolds were fabricated by a stereolithographic method using a 405 nm laser. Hybrid hydrogel scaffolds of chitosan (50-190 kDa) and PEGDA (575 Da) were mixed at varying feed-ratios. Some of the cationic, amino groups of chitosan were neutralized by dialysis in acidic solution containing chitosan in excess of sodium acetate solution to inhibit quenching of newly formed photoradicals. A feed-ratio of 1:7.5 was found to be the most appropriate of the formulations considered in this study in terms of mechanical properties, cell adhesion, and printability. The biofabricated hybrid scaffold showed interconnected, homogeneous pores with a nominal pore size of 50 µm and an elastic modulus of ~400 kPa. Moreover, long-term cell viability and cell spreading was observed via actin filament staining. Printability of the biocompatible resin was confirmed by printing thresholded MR images of an ear and the feed ratio of 1:7.5 provided the most faithful reproduction of the shape. To the best of our knowledge, this is the first report of stereolithographic printing hybridizing cell-adhesive properties of chitosan with mechanical robustness of PEG in scaffolds suitable for repair of complex tissue geometries, such as those of the human ear.

  11. Effects of hydrophobic and hydrophilic modifications on gene delivery of amphiphilic chitosan based nanocarriers.

    PubMed

    Wang, Bingqing; He, Chunbai; Tang, Cui; Yin, Chunhua

    2011-07-01

    The structure-activity relationships between hydrophobic and hydrophilic modification on chitosan and resultant physicochemical properties along with performances in dealing with critical gene delivery barriers were investigated through amphiphilic linoleic acid(LA) and poly (β-malic acid) (PMLA) double grafted chitosan (LMC)/plasmid DNA (pDNA) nanocomplexes. LMC polymers with various LA and PMLA substitution degrees were synthesized and their hydrophilicity/hydrophobicity was characterized. Compared to chitosan, LMC nanoparticles retained the pDNA binding ability at pH 5.5 when they formed nanocomplexes with pDNA encoding enhanced green fluorescence protein (pEGFP) and the resultant complexes showed diameters below 300 nm. Hydrophobic LA and hydrophilic PMLA substitution contributed to suppressed non-specific adsorption, reduced interactions inside LMC/pDNA nanocomplexes, and enhanced pDNA dissociation. However, enzymatic degradation resistance, cell adsorption, and cellular uptake through clathrin-mediated pathway were promoted by hydrophobic LA grafting while being inhibited by hydrophilic PMLA substitution. In vitro transfection assay suggested the optimal LMC/pEGFP nanocomplexes mediated an 8.0-fold improved transfection compared to chitosan/pEGFP nanocomplexes. The 4.2-fold and 2.2-fold higher intramuscular gene expression in mice compared to chitosan/pEGFP and polyethyleneimine (PEI)/pEGFP nanocomplexes further demonstrated the superiority of LMC/pDNA nanocomplexes. Therefore, amphiphilic chitosan derivates with appropriate combination of hydrophobic and hydrophilic modification would be promising gene delivery nanocarriers. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Green synthesis of gold-chitosan nanocomposites for caffeic acid sensing.

    PubMed

    Di Carlo, Gabriella; Curulli, Antonella; Toro, Roberta G; Bianchini, Chiara; De Caro, Tilde; Padeletti, Giuseppina; Zane, Daniela; Ingo, Gabriel M

    2012-03-27

    In this work, colloidal gold nanoparticles (AuNPs) stabilized into a chitosan matrix were prepared using a green route. The synthesis was carried out by reducing Au(III) to Au(0) in an aqueous solution of chitosan and different organic acids (i.e., acetic, malonic, or oxalic acid). We have demonstrated that by varying the nature of the acid it is possible to tune the reduction rate of the gold precursor (HAuCl(4)) and to modify the morphology of the resulting metal nanoparticles. The use of chitosan, a biocompatible and biodegradable polymer with a large number of amino and hydroxyl functional groups, enables the simultaneous synthesis and surface modification of AuNPs in one pot. Because of the excellent film-forming capability of this polymer, AuNPs-chitosan solutions were used to obtain hybrid nanocomposite films that combine highly conductive AuNPs with a large number of organic functional groups. Herein, Au-chitosan nanocomposites are successfully proposed as sensitive and selective electrochemical sensors for the determination of caffeic acid, an antioxidant that has recently attracted much attention because of its benefits to human health. A linear response was obtained over a wide range of concentration from 5.00 × 10(-8) M to 2.00 × 10(-3) M, and the limit of detection (LOD) was estimated to be 2.50 × 10(-8) M. Moreover, further analyses have demonstrated that a high selectivity toward caffeic acid can be achieved without interference from catechin or ascorbic acid (flavonoid and nonphenolic antioxidants, respectively). This novel synthesis approach and the high performances of Au-chitosan hybrid materials in the determination of caffeic acid open up new routes in the design of highly efficient sensors, which are of great interest for the analysis of complex matrices such as wine, soft drinks, and fruit beverages.

  13. Effects of carboxymethyl chitosan on the blood system of rats

    SciTech Connect

    Fu, Dawei; Han, Baoqin; Dong, Wen; Yang, Zhao; Lv, You; Liu, Wanshun

    2011-04-29

    Highlights: {yields} We report, for the first time, the safety of carboxymethyl chitosan in blood system. {yields} CM-Chitosan has no significant effects on coagulation function of rats. {yields} CM-Chitosan has no significant effects on anticoagulation performance of rats. {yields} CM-Chitosan has no significant effects on fibrinolytic function of rats. {yields} CM-Chitosan has no significant effects on hemorheology of rats. -- Abstract: Carboxymethyl chitosan (CM-chitosan), a derivative of chitosan, was extensively studied in the biomedical materials field for its beneficial biological properties of hemostasis and stimulation of healing. However, studies examining the safety of CM-chitosan in the blood system are lacking. In this study CM-chitosan was implanted into the abdominal cavity of rats to determine blood indexes at different times and to evaluate the effects of CM-chitosan on the blood system of rats. Coagulation function was reflected by thrombin time (TT), prothrombin time (PT), activated partial thromboplatin time (APTT), fibrinogen (FIB) and platelet factor 4 (PF4) indexes; anti-coagulation performance was assessed by the index of antithrombinIII (ATIII); fibrinolytic function was reflected by plasminogen (PLG) and fibrin degradation product (FDP) indexes; and blood viscosity (BV) and plasma viscosity (PV) indexes reflected hemorheology. Results showed that CM-chitosan has no significant effects on the blood system of rats, and provides experimental basis for CM-chitosan to be applied in the field of biomedical materials.

  14. Flocculation of river silt using chitosan.

    PubMed

    Divakaran, Ravi; Pillai, V N Sivasankara

    2002-05-01

    Flocculation of silt in river water using chitosan was studied in the pH range 4-9, and suspended solid concentrations in the range 20-80 mg/L. Chitosan effectively reduces turbidity due to silt by flocculation and settling. Flocculation efficiency is very sensitive to pH, and reaches a maximum at pH 7. The optimal chitosan concentration required to effect flocculation is 0.5 mg/L and is independent of silt concentration within the range examined. Restabilisation of the suspension is observed at higher concentrations of chitosan, and the amount required for restabilisation increases with increasing concentration of suspended solids. Flocculation is faster at higher concentrations of silt and the flocs are large and fibrous.

  15. Fluorescent Bioactive Corrole Grafted-Chitosan Films.

    PubMed

    Barata, Joana F B; Pinto, Ricardo J B; Vaz Serra, Vanda I R C; Silvestre, Armando J D; Trindade, Tito; Neves, Maria Graça P M S; Cavaleiro, José A S; Daina, Sara; Sadocco, Patrizia; Freire, Carmen S R

    2016-04-11

    Transparent corrole grafted-chitosan films were prepared by chemical modification of chitosan with a corrole macrocycle, namely, 5,10,15-tris(pentafluorophenyl)corrole (TPFC), followed by solvent casting. The obtained films were characterized in terms of absorption spectra (UV-vis), FLIM (fluorescence lifetime imaging microscopy), structure (FTIR, XPS), thermal stability (TGA), thermomechanical properties (DMA), and antibacterial activity. The results showed that the chemical grafting of chitosan with corrole units did not affect its film-forming ability and that the grafting yield increased with the reaction time. The obtained transparent films presented fluorescence which increases with the amount of grafted corrole units. Additionally, all films showed bacteriostatic effect against S. aureus, as well as good thermomechanical properties and thermal stability. Considering these features, promising applications may be envisaged for these corrole-chitosan films, such as biosensors, bioimaging agents, and bioactive optical devices.

  16. Tannic acid incorporation in chitosan-based microparticles and in vitro controlled release.

    PubMed

    Aelenei, Neculai; Popa, Marcel Ionel; Novac, Ovidiu; Lisa, Gabriela; Balaita, Lacramioara

    2009-05-01

    Chitosan, a natural polycationic polysaccharide, was coupled with two polyanionic polymers: Na-alginate and carboxymethylcellulose (CMC) and with tannic acid (TA) obtaining three species of self-assembled complexes: chitosan/alginate/TA (sample 1), chitosan/TA (sample 2) and chitosan/CMC/TA (sample 3). The microparticle formation was achieved by dropwise addition of one solution into other by using a coaxial airflow sprayer. These systems were characterized with regard to particle size distribution, thermal stability, tannic acid entrapment efficiency. Sample 2 showed quite a different behavior compared to the other two samples; the particle diameter is located in the nanometric region, the quantity of incorporated tannic acid is higher than in the other two samples and the material shows better thermal stability. The release of tannic acid from these complexes was studied in water (pH = 5.89), phosphates buffer (pH = 7.04) and acetate buffer (pH = 4.11). These studies revealed two distinct periods in tannic acid delivery process: an initial period, varying between 4 and 10 h, characterized by a high release rate with a delivered tannic acid amount of approximately 80% of the incorporated polyphenol and a second period, which starts after 20 to 30 h of delivery and it ends after approximately 120 h, when the release process takes place with low and constant rate and the kinetic curve is linear--characteristic for a zero order kinetic.

  17. Immunostimulative Activity of Low Molecular Weight Chitosans in RAW264.7 Macrophages.

    PubMed

    Wu, Ning; Wen, Zheng-Shun; Xiang, Xing-Wei; Huang, Yan-Na; Gao, Yang; Qu, You-Le

    2015-09-30

    Chitosan and its derivatives such as low molecular weight chitosans (LMWCs) have been reported to exert many biological activities, such as antioxidant and antitumor effects. However, complex and molecular weight dependent effects of chitosan remain controversial and the mechanisms that mediate these complex effects are still poorly defined. This study was carried out to investigate the immunostimulative effect of different molecular weight chitosan in RAW264.7 macrophages. Our data suggested that two LMWCs (molecular weight of 3 kDa and 50 kDa) both possessed immunostimulative activity, which was dependent on dose and, at the higher doses, also on the molecular weight. LMWCs could significantly enhance the the pinocytic activity, and induce the production of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interferon-γ (IFN-γ), nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in a molecular weight and concentration-dependent manner. LMWCs were further showed to promote the expression of the genes including iNOS, TNF-α. Taken together, our findings suggested that LMWCs elicited significantly immunomodulatory response through up-regulating mRNA expression of proinflammatory cytokines and activated RAW264.7 macrophage in a molecular weight- and concentration-dependent manner.

  18. Immunostimulative Activity of Low Molecular Weight Chitosans in RAW264.7 Macrophages

    PubMed Central

    Wu, Ning; Wen, Zheng-Shun; Xiang, Xing-Wei; Huang, Yan-Na; Gao, Yang; Qu, You-Le

    2015-01-01

    Chitosan and its derivatives such as low molecular weight chitosans (LMWCs) have been reported to exert many biological activities, such as antioxidant and antitumor effects. However, complex and molecular weight dependent effects of chitosan remain controversial and the mechanisms that mediate these complex effects are still poorly defined. This study was carried out to investigate the immunostimulative effect of different molecular weight chitosan in RAW264.7 macrophages. Our data suggested that two LMWCs (molecular weight of 3 kDa and 50 kDa) both possessed immunostimulative activity, which was dependent on dose and, at the higher doses, also on the molecular weight. LMWCs could significantly enhance the the pinocytic activity, and induce the production of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interferon-γ (IFN-γ), nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in a molecular weight and concentration-dependent manner. LMWCs were further showed to promote the expression of the genes including iNOS, TNF-α. Taken together, our findings suggested that LMWCs elicited significantly immunomodulatory response through up-regulating mRNA expression of proinflammatory cytokines and activated RAW264.7 macrophage in a molecular weight- and concentration-dependent manner. PMID:26437419

  19. Chitosan-plasmid DNA nanoparticles encoding small hairpin RNA targeting MMP-3 and -13 to inhibit the expression of dedifferentiation related genes in expanded chondrocytes.

    PubMed

    Zhao, Jingxin; Fan, Xiangli; Zhang, Qiang; Sun, Fangfei; Li, Xiaojian; Xiong, Chuan; Zhang, Chunli; Fan, Hongbin

    2014-02-01

    Overexpression of matrix metalloproteinase (MMP)-3 and -13 can lead to the dedifferentiation of expanded chondrocytes. After implanting dedifferentiated cells for cartilage defect repair, graft failure may occur. Short hairpin RNA (shRNA) is a powerful genetic tool to reduce the expression of target genes. This study investigated the effects of chitosan-plasmid DNA (pDNA) nanoparticles encoding shRNA targeting MMP-3 and -13 on the dedifferentiation of expanded chondrocytes. The objective was to optimize the parameters of chitosan-pDNA formulation for achieving higher efficiency of pDNA delivery and gene silencing. The chitosan-pDNA nanoparticles were prepared using a complex coacervation process. Then the characteristics including size, shape, stability, and transfection efficiency were compared in different groups. The results indicated that chitosan of 800 kDa at N/P ratio of 4 and pH 7.0 was optimal to prepare chitosan-pDNA nanoparticles. These nanoparticles showed high DNA loading efficiency (95.8 ± 1.5%) and high gene transfection efficiency (24.5 ± 1.6%). After the expanded chondrocytes were transfected by chitosan-pDNA nanoparticles, MMP-3-610 and MMP-13-2024 groups showed greater suppression in mRNA and protein levels. The results indicated that chitosan-pDNA nanoparticles encoding shRNA targeting MMP-3 and -13 had great potential in silencing the dedifferentiation-related genes for regenerating prolonged and endurable cartilage.

  20. Irradiating or autoclaving chitosan/polyol solutions: effect on thermogelling chitosan-beta-glycerophosphate systems.

    PubMed

    Jarry, Claire; Leroux, Jean-Christophe; Haeck, Jonathan; Chaput, Cyril

    2002-10-01

    The effects of steam sterilization and gamma-irradiation on chitosan and thermogelling chitosan-beta-glycerophosphate (GP) solutions containing polyol additives were investigated. The selected polyols were triethylene glycol, glycerol, sorbitol, glucose and poly(ethylene glycol) (PEG). They were incorporated to chitosan solutions prior to sterilization in a proportion ranging from 1 to 5% (w/v). The solutions were characterized with respect to their viscosity, thermogelling properties, compressive stress relaxation behavior and chitosan degradation. All polyols reduced the autoclaving-induced viscosity loss and had a positive impact on the solution thermogelling properties and compressive performance of the gels. Steam sterilization in the presence of glucose resulted in a substantial increase in the solution viscosity and gel strength. This was associated with a strong discoloration suggesting chemical alteration of the system. PEG was the most effective agent in preventing hydrolytic degradation of chitosan chains. Gamma-irradiation strongly decreased the chitosan solution viscosity regardless of the presence of additives, even when sterilization was carried out at -80 degrees C. Moreover, the thermogelling properties were dramatically altered, and thus, gamma-irradiation would not be an appropriate method to sterilize chitosan solutions. In conclusion, polyols are potentially useful additive to maximise the viscoelastic and mechanical properties of chitosan-GP after steam sterilization.

  1. Effect of chitosan molecular weight on rheological behavious of chitosan modified nanoclay at highly hydrated state

    USDA-ARS?s Scientific Manuscript database

    Effect of chitosan molecular weight (M(cs)) on the rheological properties of chitosan modified clay (CMCs) at highly hydrated state was investigated. With special emphasis on its effect on the thixotropy of CMCs, the structure recovery at rest after underwent a pre-shearing process was further perfo...

  2. Arsenic removal using a biopolymer chitosan sorbent.

    PubMed

    Chen, Chiing-Chang; Chung, Ying-Chien

    2006-01-01

    An agricultural waste, chitosan, was converted to bead form to evaluate the feasibility of its use to remove As(III) and As(V) from water in both batch and continuous operations. In batch tests, the effect of pH, temperature, coexisting ions, and arsenic concentrations were studied. Studies of kinetic adsorption, recovery of arsenic by desorption solution, and reuse of chitosan beads were also carried out. Additionally, wastewater containing arsenic discharged from the manufacturing of GaAs supports was treated in a continuous operation. Results indicated that chitosan beads favored the adsorption of As(V), but not As(III). The optimal pH value for As(III) and As(V) removal was near 5. The insignificant difference for As(V) and As(III) adsorption by chitosan beads was found in the 25-40 degrees C range. Ion coexistence below 50 mg/L did not affect arsenic removal. The optimal desorption solution for the arsenic recovery was H2SO4 with a 71% efficiency for As(V), which was amenable to efficient regeneration for multiple reuse (about 15 times). In continuous tests, the chitosan bead column exhibited excellent arsenic removal from actual wastewater without any pretreatment. The results provide strong evidence of the promise the application of chitosan bead has for arsenic removal.

  3. Maillard reaction products from chitosan-xylan ionic liquid solution.

    PubMed

    Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

    2013-10-15

    A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Characterization of bioactive chitosan and sulfated chitosan from Doryteuthis singhalensis (Ortmann, 1891).

    PubMed

    Ramasamy, Pasiyappazham; Subhapradha, Namasivayam; Thinesh, Thangadurai; Selvin, Joseph; Selvan, Kanagaraj Muthamizh; Shanmugam, Vairamani; Shanmugam, Annaian

    2017-06-01

    Chitosan was extracted from the pen of squid Doryteuthis singhalensis and characterized using FT-IR, NMR, CHN, SEM and DSC analysis. Purified chitosan was sulfated with chlorosulfonic acid in N,N-dimethylformamide and the added sulfate group was confirmed with FT-IR analysis. The molecular weight and degree of deacetylation (DDA) of chitosan was found 226.6kDa and 83.76% respectively. Chitosan exhibited potent antioxidant activity evidenced by reducing power, chelating ability on ferrous ions and scavenging activity on DPPH, superoxide and hydroxyl radicals. The anticoagulant assay using activated partial thromboplastin time (APTT) and prothrombin time (PT) showed chitosan as a strong anticoagulant. The results of this study showed possibility of using D. singhalensis pen as a non-conventional source of natural antioxidants and anticoagulant which can be incorporated in functional food formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Preparation and antibacterial activity of quaternized chitosan with iodine.

    PubMed

    Tang, Yang; Xie, Linlin; Sai, Mingze; Xu, Ningning; Ding, Derun

    2015-03-01

    Chitosan (CTS) is a natural polymer with active groups such as -NH2 which can be functionalized to introduce new positively charged N-atoms and protonated amino group for better use. In this study, to improve the stability of iodine, a novel complex (CTS-CTA-I2) was prepared by mixing N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (CTS-CTA) with iodine in ethanol solution. The CTS-CTA-I2 was characterized by Fourier transform infrared spectra (FTIR), Ultraviolet and visible (UV-vis) spectra and thermal gravimetric analysis (TG). Besides, the interaction of iodine with CTS-CTA was also studied. The mole ratio of CTS-CTA with iodine was measured by iodometric titration method and the max mole ratio of CTS-CTA with iodine was 1:1.33. The antimicrobial activity of CTS, CTS-CTA and CTS-CTS-I2 complexes was investigated against Escherichia coli and Staphylococcus aureus and the antibacterial property of CTS-CTA-I2 was superior to CTS-CTA. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Synthesis and characterization of collagen/hyaluronan/chitosan composite sponges for potential biomedical applications.

    PubMed

    Lin, Yen-Chih; Tan, Fa-Jui; Marra, Kacey G; Jan, Shyh-Shyan; Liu, Deng-Cheng

    2009-09-01

    :1:1 mixing ratio of collagen, hyaluronan and chitosan to be optimal for the manufacture of complex scaffolds. Furthermore, Col-HA-Ch tri-polymer scaffolds, especially Col9HACh1, could be developed as a suitable scaffold material for tissue engineering applications.

  7. Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

    PubMed Central

    Cheung, Randy Chi Fai; Ng, Tzi Bun; Wong, Jack Ho; Chan, Wai Yee

    2015-01-01

    Chitosan is a natural polycationic linear polysaccharide derived from chitin. The low solubility of chitosan in neutral and alkaline solution limits its application. Nevertheless, chemical modification into composites or hydrogels brings to it new functional properties for different applications. Chitosans are recognized as versatile biomaterials because of their non-toxicity, low allergenicity, biocompatibility and biodegradability. This review presents the recent research, trends and prospects in chitosan. Some special pharmaceutical and biomedical applications are also highlighted. PMID:26287217

  8. Improved chitosan-mediated gene delivery based on easily dissociated chitosan polyplexes of highly defined chitosan oligomers.

    PubMed

    Köping-Höggård, M; Vårum, K M; Issa, M; Danielsen, S; Christensen, B E; Stokke, B T; Artursson, P

    2004-10-01

    Nonviral gene delivery systems based on conventional high-molecular-weight chitosans are efficient after lung administration in vivo, but have poor physical properties such as aggregated shapes, low solubility at neutral pH, high viscosity at concentrations used for in vivo delivery and a slow dissociation and release of plasmid DNA, resulting in a slow onset of action. We therefore developed highly effective nonviral gene delivery systems with improved physical properties from a series of chitosan oligomers, ranging in molecular weight from 1.2 to 10 kDa. First, we established structure-property relationships with regard to polyplex formation and in vivo efficiency after lung administration to mice. In a second step, we isolated chitosan oligomers from a preferred oligomer fraction to obtain fractions, ranging from 10 to 50-mers, of more homogeneous size distributions with polydispersities ranging from 1.01 to 1.09. Polyplexes based on chitosan oligomers dissociated more easily than those of a high-molecular-weight ultrapure chitosan (UPC, approximately a 1000-mer), and released pDNA in the presence of anionic heparin. The more easily dissociated polyplexes mediated a faster onset of action and gave a higher gene expression both in 293 cells in vitro and after lung administration in vivo as compared to the more stable UPC polyplexes. Already 24 h after intratracheal administration, a 120- to 260-fold higher luciferase gene expression was observed compared to UPC in the mouse lung in vivo. The gene expression in the lung was comparable to that of PEI (respective AUCs of 2756+/-710 and 3320+/-871 pg luciferase x days/mg of total lung protein). In conclusion, a major improvement of chitosan-mediated nonviral gene delivery to the lung was obtained by using polyplexes of well-defined chitosan oligomers. Polyplexes of oligomer fractions also had superior physicochemical properties to commonly used high-molecular-weight UPC.

  9. Removal of As(III) and As(V) from water by chitosan and chitosan derivatives: a review.

    PubMed

    Wang, Xianli; Liu, Yukun; Zheng, Jingtang

    2016-07-01

    As arsenic removal becomes a global concern, the development of removal processes for arsenic treatment is still a major challenge. With regard to environmental compatibility and cheapness, chitosan and chitosan derivatives are considered as a promising removal technology for arsenic. Chitosan and chitosan derivatives possess the properties of low cost and good sorption on the arsenic removal. The present review is concerned about the present understanding of the mechanisms involved in sorption processes. Further on, detailed discussions are given of the effects of various factors on the performance of chitosan and chitosan derivatives in arsenic treatment processes. Finally, special attention is paid to the future challenges of chitosan and chitosan derivatives utilized for industrial arsenic treatment.

  10. The effect of ratio chitosan-bentonite and processing time on the characterization of chitosan-bentonite composite

    NASA Astrophysics Data System (ADS)

    Savitri, E.; Budhyantoro, A.

    2017-07-01

    Chitosan/bentonite composite was synthesized to modify and enhance its characteristics to adsorp both anionic and cationic substances. The influence of several factors on synthesis of the chitosan/bentonite composite were investigated. The study focused on obtaining the best operating conditions that would produce homogenous chitosan/bentonite composite. The effect of weight ratio of bentonite to chitosan, reaction times and pre-treatment were investigated. The composite were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and Scanning electron microscopy. The optimum chitosan/bentonite composite was obtained at weight ratio of bentonite to chitosan 1 : 2 and 12 hours reaction. On these conditions, more chitosan can interact with the matrix of bentonite to form chitosan - bentonite composite.

  11. In vitro antibacterial activity of chitosan and chitosan oligosaccharide lactate against important gram negative warmwater fish pathogens

    USDA-ARS?s Scientific Manuscript database

    Aim: The antibacterial activities of chitosan (CS) and its derivative chitosan oligosaccharide lactate (COL) were evaluated against Aeromonas hydrophila, Edwardsiella ictaluri and Flavobacterium columnare, three highly pathogenic bacteria of warmwater finfish. Methods and Results: The kinetics of ce...

  12. Pyridine-grafted chitosan derivative as an antifungal agent.

    PubMed

    Jia, Ruixiu; Duan, Yunfei; Fang, Qiang; Wang, Xiangyang; Huang, Jianying

    2016-04-01

    Pyridine moieties were introduced into chitosan by nucleophilic substitution to afford N-(1-carboxybutyl-4-pyridinium) chitosan chloride (pyridine chitosan). The resulting chitosan derivative was well characterized, and its antifungal activity was examined, based on the inhibition of mycelial growth and spore germination. The results indicated that pyridine chitosan exhibited enhanced antifungal activity by comparison with pristine chitosan. The values of the minimum inhibitory concentration and the minimal fungicidal concentration of pyridine chitosan against Fulvia fulva were 0.13 mg/ml and 1 mg/ml, respectively, while the corresponding values against Botrytis cinerea were 0.13 mg/ml and 4 mg/ml, respectively. Severe morphological changes of pyridine chitosan-treated B. cinerea were observed, indicative that pyridine chitosan could damage and deform the structure of fungal hyphae and subsequently inhibit strain growth. Non-toxicity of pyridine chitosan was demonstrated by an acute toxicity study. These results are beneficial for assessing the potential utilization of this chitosan derivative and for exploring new functional antifungal agents with chitosan in the food industry.

  13. Vitamin D-fortified chitosan films from mushroom waste

    USDA-ARS?s Scientific Manuscript database

    Brown mushroom (Agaricus bisporus) stalk bases from mushroom waste were treated with UV-B light to rapidly increase vitamin D2 content. Chitin was also recovered from this waste and converted into chitosan by N-deacetylation. FTIR spectra showed that the mushroom chitosan were similar to chitosan fr...

  14. Removal of nitrate and phosphate using chitosan/Al2O3/Fe3O4 composite nanofibrous adsorbent: Comparison with chitosan/Al2O3/Fe3O4 beads.

    PubMed

    Bozorgpour, Farahnaz; Ramandi, Hossein Fasih; Jafari, Pooya; Samadi, Saman; Yazd, Shabnam Sharif; Aliabadi, Majid

    2016-12-01

    In the present study the chitosan/Al2O3/Fe3O4 composite nanofibrous adsorbent was prepared by electrospinning process and its application for the removal of nitrate and phosphate were compared with chitosan/Al2O3/Fe3O4 composite bead adsorbent. The influence of Al2O3/Fe3O4 composite content, pH, contact time, nitrate and phosphate initial concentrations and temperature on the nitrate and phosphate sorption using synthesized bead and nanofibrous adsorbents was investigated in a single system. The reusability of chitosan/Al2O3/Fe3O4 composite beads and nanofibers after five sorption-desorption cycles were carried out. The Box-Behnken design was used to investigate the interaction effects of adsorbent dosage, nitrate and phosphate initial concentrations on the nitrate and phosphate removal efficiency. The pseudo-second-order kinetic model and known Freundlich and Langmuir isotherm models were used to describe the kinetic and equilibrium data of nitrate and phosphate sorption using chitosan/Al2O3/Fe3O4 composite beads and nanofibers. The influence of other anions including chloride, fluoride and sulphate on the sorption efficiency of nitrate and phosphate was examined. The obtained results revealed the higher potential of chitosan/Al2O3/Fe3O4 composite nanofibers for nitrate and phosphate compared with chitosan/Al2O3/Fe3O4 composite beads. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Hydrophobically modified chitosan/gold nanoparticles for DNA delivery

    NASA Astrophysics Data System (ADS)

    Bhattarai, Shanta Raj; K. C., Remant Bahadur; Aryal, Santosh; Bhattarai, Narayan; Kim, Sun Young; Yi, Ho Keun; Hwang, Pyoung Han; Kim, Hak Yong

    2008-01-01

    Present study dealt an application of modified chitosan gold nanoparticles (Nac-6-Au) for the immobilization of necked plasmid DNA. Gold nanoparticles stabilized with N-acylated chitosan were prepared by graft-onto approach. The stabilized gold nanoparticles were characterized by different physico-chemical techniques such as UV-vis, TEM, ELS and DLS. MTT assay was used for in vitro cytotoxicity of the nanoparticles into three different cell lines (NIH 3T3, CT-26 and MCF-7). The formulation of plasmid DNA with the nanoparticles corresponds to the complex forming capacity and in-vitro/in-vivo transfection efficiency was studied via gel electrophoresis and transfection methods, respectively. Results showed the modified chitosan gold nanoparticles were well-dispersed and spherical in shape with average size around 10˜12 nm in triple distilled water at pH 7.4, and showed relatively no cytotoxicity at low concentration. Addition of plasmid DNA on the aqueous solution of the nanoparticles markedly reduced surface potential (50.0˜66.6%) as well as resulted in a 13.33% increase in hydrodynamic diameters of the formulated nanoparticles. Transfection efficiency of Nac-6-Au/DNA was dependent on cell type, and higher β-galactosidase activity was observed on MCF-7 breast cancer cell. Typically, this activity was 5 times higher in 4.5 mg/ml nanoparticles concentration than that achieved by the nanoparticles of other concentrations (and/or control). However, this activity was lower in in-vitro and dramatically higher in in-vivo than that of commercially available transfection kit (Lipofectin®) and DNA. From these results, it can be expected to develop alternative new vectors for gene delivery.

  16. Stability assessment of chitosan-sodium hexametaphosphate capsules.

    PubMed

    Angelova, N; Hunkeler, D

    2001-01-01

    The assessment of the stability of capsules based on chitosan-sodium hexametaphosphate complex formation has been carried out using two independent methods--compression and osmotic swelling, and the influence of the preparation variables was evaluated. The formulation containing 1.5% core polymer (chitosan) and 1.5% oligophosphate, in the absence of salt or at low ionic strength (0.15% NaCl) was found to provide the best membrane resistance. A higher concentration of cross-linker (2.25%) produced stable capsules only in absence of electrolyte. Mannitol, a porogen added to the preparation solutions, did not affect the stability of the obtained membranes. At elevated polyol (1%) and cross-linker levels (2.25%), and at 0% salt, membranes with decreased elasticity were obtained, having lower compression and osmotic bursting values and lower deformation at the breaking points. A significant influence of salt amount on the capsule stability was also found. This was attributed to changes in the membrane formation process resulting in membranes with different thickness and structure. Membrane compression stability was found to be dependent on the pH of both oligophosphate and chitosan solutions, as well as on the reaction time. The bursting force values decreased for capsule diameters below 1.6 mm. The increased membrane/capsule volume ratio for the small capsules decreased the capsule deformation freedom and caused capsule rupture at low force values. The capsules made at low salt amounts showed very good storage stability over time and at elevated temperatures. The results demonstrated that the capsules could be formulated with controlled properties for various biomedical applications.

  17. Physicochemical and biological characterization of chitosan-microRNA nanocomplexes for gene delivery to MCF-7 breast cancer cells

    PubMed Central

    Santos-Carballal, B.; Aaldering, L. J.; Ritzefeld, M.; Pereira, S.; Sewald, N.; Moerschbacher, B. M.; Götte, M.; Goycoolea, F. M.

    2015-01-01

    Cancer gene therapy requires the design of non-viral vectors that carry genetic material and selectively deliver it with minimal toxicity. Non-viral vectors based on cationic natural polymers can form electrostatic complexes with negatively-charged polynucleotides such as microRNAs (miRNAs). Here we investigated the physicochemical/biophysical properties of chitosan–hsa-miRNA-145 (CS–miRNA) nanocomplexes and the biological responses of MCF-7 breast cancer cells cultured in vitro. Self-assembled CS–miRNA nanocomplexes were produced with a range of (+/−) charge ratios (from 0.6 to 8) using chitosans with various degrees of acetylation and molecular weight. The Z-average particle diameter of the complexes was <200 nm. The surface charge increased with increasing amount of chitosan. We observed that chitosan induces the base-stacking of miRNA in a concentration dependent manner. Surface plasmon resonance spectroscopy shows that complexes formed by low degree of acetylation chitosans are highly stable, regardless of the molecular weight. We found no evidence that these complexes were cytotoxic towards MCF-7 cells. Furthermore, CS–miRNA nanocomplexes with degree of acetylation 12% and 29% were biologically active, showing successful downregulation of target mRNA expression in MCF-7 cells. Our data, therefore, shows that CS–miRNA complexes offer a promising non-viral platform for breast cancer gene therapy. PMID:26324407

  18. Simultaneous R2*, R2, and R2' quantification by combining S0 estimation of the free induction decay with a single spin echo: A single acquisition method for R2 insensitive quantification of holmium-166-loaded microspheres.

    PubMed

    van de Maat, G H; de Leeuw, H; Seevinck, P R; van den Bosch, M A A J; Nijsen, J F W; Bakker, C J G

    2015-01-01

    To present a new method, S0 estimation of the free induction decay combined with a single spin echo measurement (SOFIDSE), that enables simultaneous measurements of R2*, R2, and R2' in order to quantify the local concentration of holmium microspheres (Ho-MS) for radioembolization. SOFIDSE estimates R2* and the signal magnitude at time point 0, S0, from a multigradient echo readout of the free induction decay and subsequently estimates R2 using S0 and a single spin echo, from which R2' is deducted. The method was evaluated by comparing SOFIDSE R2 values with values obtained from shifted spin echo (SSE) measurements on a phantom setup containing Ho-MS and from dual spin echo measurements on a healthy volunteer. On average, SOFIDSE showed a small overestimation of R2 values compared with SSE independent of the microsphere concentration. R2' values determined by subtraction of either SOFIDSE R2 or SSE R2 from R2* showed excellent agreement (correlation coefficient = 1; P = 9 · 10(-11)). The Ho-MS-induced R2' values obtained by SOFIDSE were insensitive to the R2 value of the tissue in which they resided. SOFIDSE enables quantification of Ho-MS, in media with spatially or temporally varying R2 values, in a single acquisition. © 2014 Wiley Periodicals, Inc.

  19. Development and characterization of chitosan-PEG-TAT nanoparticles for the intracellular delivery of siRNA.

    PubMed

    Malhotra, Meenakshi; Tomaro-Duchesneau, Catherine; Saha, Shyamali; Kahouli, Imen; Prakash, Satya

    2013-01-01

    Recently, cell-penetrating peptides have been proposed to translocate antibodies, proteins, and other molecules in targeted drug delivery. The proposed study presents the synthesis and characterization of a peptide-based chitosan nanoparticle for small interfering RNA (siRNA) delivery, in-vitro. Specifically, the synthesis included polyethylene glycol (PEG), a hydrophilic polymer, and trans-activated transcription (TAT) peptide, which were chemically conjugated on the chitosan polymer. The conjugation was achieved using N-Hydroxysuccinimide-PEG-maleimide (heterobifunctional PEG) as a cross-linker, with the bifunctional PEG facilitating the amidation reaction through its N-Hydroxysuccinimide group and reacting with the amines on chitosan. At the other end of PEG, the maleimide group was chemically conjugated with the cysteine-modified TAT peptide. The degree of substitution on chitosan with PEG and on PEG with TAT was confirmed using colorimetric assays. The resultant polymer was used to form nanoparticles complexing siRNA, which were then characterized for particle size, morphology, cellular uptake, and cytotoxicity. The nanoparticles were tested in-vitro on mouse neuroblastoma cells (Neuro2a). Particle size and surface charge were characterized and an optimal pH condition and PEG molecular weight were determined to form sterically stable nanoparticles. Results indicate 7.5% of the amines in chitosan polymer were conjugated to the PEG and complete conjugation of TAT peptide was observed on the synthesized PEGylated chitosan polymer. Compared with unmodified chitosan nanoparticles, the nanoparticles formed at pH 6 were monodispersed and of <100 nm in size, exhibiting maximum cell transfection ability and very low cytotoxicity. Thus, this research may be of significance in translocating biotherapeutic molecules for intracellular delivery applications.

  20. Effect of Experimental Parameters on Alginate/Chitosan Microparticles for BCG Encapsulation

    PubMed Central

    Caetano, Liliana A.; Almeida, António J.; Gonçalves, Lídia M.D.

    2016-01-01

    The aim of the present study was to develop novel Mycobacterium bovis bacille Calmette-Guérin (BCG)-loaded polymeric microparticles with optimized particle surface characteristics and biocompatibility, so that whole live attenuated bacteria could be further used for pre-exposure vaccination against Mycobacterium tuberculosis by the intranasal route. BCG was encapsulated in chitosan and alginate microparticles through three different polyionic complexation methods by high speed stirring. For comparison purposes, similar formulations were prepared with high shear homogenization and sonication. Additional optimization studies were conducted with polymers of different quality specifications in a wide range of pH values, and with three different cryoprotectors. Particle morphology, size distribution, encapsulation efficiency, surface charge, physicochemical properties and biocompatibility were assessed. Particles exhibited a micrometer size and a spherical morphology. Chitosan addition to BCG shifted the bacilli surface charge from negative zeta potential values to strongly positive ones. Chitosan of low molecular weight produced particle suspensions of lower size distribution and higher stability, allowing efficient BCG encapsulation and biocompatibility. Particle formulation consistency was improved when the availability of functional groups from alginate and chitosan was close to stoichiometric proportion. Thus, the herein described microparticulate system constitutes a promising strategy to deliver BCG vaccine by the intranasal route. PMID:27187418

  1. Development and characterization of chitosan/hyaluronan film for transdermal delivery of thiocolchicoside.

    PubMed

    Bigucci, Federica; Abruzzo, Angela; Saladini, Bruno; Gallucci, Maria Caterina; Cerchiara, Teresa; Luppi, Barbara

    2015-10-05

    The objective of this study was the development of chitosan/hyaluronan transdermal films to improve bioavailability of thiocolchicoside. This approach offers the possibility to elude the first-pass metabolism and at the same time it is able to provide a predictable and extended duration of activity. Films were prepared by casting and drying of aqueous solutions containing different weight ratios of chitosan and hyaluronan and characterized for their physico-chemical and functional properties. In accordance with polymeric composition of films and, therefore, with the amount of the net charge after the complexation, films containing the same weight ratio of chitosan and hyaluronan showed lower water uptake ability with respect to films containing only one polymeric species or an excess of chitosan or hyaluronan. Moreover, the lower the hydration of the polymeric network, the lower is the drug diffusion through the films and its permeation through the skin. This study clearly confirmed that the selection of a suitable polymeric weight ratio and appropriate preparative conditions allows the modulation of film functional properties, suggesting that these formulations could be used as a novel technological platform for transdermal drug delivery.

  2. Chitosan-based copper nanocomposite accelerates healing in excision wound model in rats.

    PubMed

    Gopal, Anu; Kant, Vinay; Gopalakrishnan, Anu; Tandan, Surendra K; Kumar, Dinesh

    2014-05-15

    Copper possesses efficacy in wound healing which is a complex phenomenon involving various cells, cytokines and growth factors. Copper nanoparticles modulate cells, cytokines and growth factors involved in wound healing in a better way than copper ions. Chitosan has been shown to be beneficial in healing because of its antibacterial, antifungal, biocompatible and biodegradable polymeric nature. In the present study, chitosan-based copper nanocomposite (CCNC) was prepared by mixing chitosan and copper nanoparticles. CCNC was applied topically to evaluate its wound healing potential and to study its effects on some important components of healing process in open excision wound model in adult Wistar rats. Significant increase in wound contraction was observed in the CCNC-treated rats. The up-regulation of vascular endothelial growth factor (VEGF) and transforming growth factor-beta1(TGF-β1) by CCNC-treatment revealed its role in facilitating angiogenesis, fibroblast proliferation and collagen deposition. The tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were significantly decreased and increased, respectively, in CCNC-treated rats. Histological evaluation showed more fibroblast proliferation, collagen deposition and intact re-epithelialization in CCNC-treated rats. Immunohistochemistry of CD31 revealed marked increase in angiogenesis. Thus, we concluded that chitosan-based copper nanocomposite efficiently enhanced cutaneous wound healing by modulation of various cells, cytokines and growth factors during different phases of healing process.

  3. Transporting Antitumor Drug Tamoxifen and Its Metabolites, 4-Hydroxytamoxifen and Endoxifen by Chitosan Nanoparticles

    PubMed Central

    Agudelo, Daniel; Sanyakamdhorn, Sriwanna; Nafisi, Shoherh; Tajmir-Riahi, Heidar-Ali

    2013-01-01

    Synthetic and natural polymers are often used as drug delivery systems in vitro and in vivo. Biodegradable chitosan of different sizes were used to encapsulate antitumor drug tamoxifen (Tam) and its metabolites 4-hydroxytamoxifen (4-Hydroxytam) and endoxifen (Endox). The interactions of tamoxifen and its metabolites with chitosan 15, 100 and 200 KD were investigated in aqueous solution, using FTIR, fluorescence spectroscopic methods and molecular modeling. The structural analysis showed that tamoxifen and its metabolites bind chitosan via both hydrophilic and hydrophobic contacts with overall binding constants of Ktam-ch-15  = 8.7 (±0.5)×103 M−1, Ktam-ch-100  = 5.9 (±0.4)×105 M−1, Ktam-ch-200  = 2.4 (±0.4)×105 M−1 and Khydroxytam-ch-15  = 2.6(±0.3)×104 M−1, Khydroxytam – ch-100  = 5.2 (±0.7)×106 M−1 and Khydroxytam-ch-200  = 5.1 (±0.5)×105 M−1, Kendox-ch-15  = 4.1 (±0.4)×103 M−1, Kendox-ch-100  = 1.2 (±0.3)×106 M−1 and Kendox-ch-200  = 4.7 (±0.5)×105 M−1 with the number of drug molecules bound per chitosan (n) 2.8 to 0.5. The order of binding is ch-100>200>15 KD with stronger complexes formed with 4-hydroxytamoxifen than tamoxifen and endoxifen. The molecular modeling showed the participation of polymer charged NH2 residues with drug OH and NH2 groups in the drug-polymer adducts. The free binding energies of −3.46 kcal/mol for tamoxifen, −3.54 kcal/mol for 4-hydroxytamoxifen and −3.47 kcal/mol for endoxifen were estimated for these drug-polymer complexes. The results show chitosan 100 KD is stronger carrier for drug delivery than chitosan-15 and chitosan-200 KD. PMID:23527310

  4. Transporting antitumor drug tamoxifen and its metabolites, 4-hydroxytamoxifen and endoxifen by chitosan nanoparticles.

    PubMed

    Agudelo, Daniel; Sanyakamdhorn, Sriwanna; Nafisi, Shoherh; Tajmir-Riahi, Heidar-Ali

    2013-01-01

    Synthetic and natural polymers are often used as drug delivery systems in vitro and in vivo. Biodegradable chitosan of different sizes were used to encapsulate antitumor drug tamoxifen (Tam) and its metabolites 4-hydroxytamoxifen (4-Hydroxytam) and endoxifen (Endox). The interactions of tamoxifen and its metabolites with chitosan 15, 100 and 200 KD were investigated in aqueous solution, using FTIR, fluorescence spectroscopic methods and molecular modeling. The structural analysis showed that tamoxifen and its metabolites bind chitosan via both hydrophilic and hydrophobic contacts with overall binding constants of K(tam-ch-15) = 8.7 ( ± 0.5) × 10(3) M(-1), K(tam-ch-100) = 5.9 (± 0.4) × 10(5) M(-1), K(tam-ch-200) = 2.4 (± 0.4) × 10(5) M(-1) and K(hydroxytam-ch-15) = 2.6(± 0.3) × 10(4) M(-1), K(hydroxytam - ch-100) = 5.2 ( ± 0.7) × 10(6) M(-1) and K(hydroxytam-ch-200) = 5.1 (± 0.5) × 10(5) M(-1), K(endox-ch-15) = 4.1 (± 0.4) × 10(3) M(-1), K(endox-ch-100) = 1.2 (± 0.3) × 10(6) M(-1) and K(endox-ch-200) = 4.7 (± 0.5) × 10(5) M(-1) with the number of drug molecules bound per chitosan (n) 2.8 to 0.5. The order of binding is ch-100>200>15 KD with stronger complexes formed with 4-hydroxytamoxifen than tamoxifen and endoxifen. The molecular modeling showed the participation of polymer charged NH2 residues with drug OH and NH2 groups in the drug-polymer adducts. The free binding energies of -3.46 kcal/mol for tamoxifen, -3.54 kcal/mol for 4-hydroxytamoxifen and -3.47 kcal/mol for endoxifen were estimated for these drug-polymer complexes. The results show chitosan 100 KD is stronger carrier for drug delivery than chitosan-15 and chitosan-200 KD.

  5. Thiolated methylated dimethylaminobenzyl chitosan: A novel chitosan derivative as a potential delivery vehicle.

    PubMed

    Hakimi, Shirin; Mortazavian, Elaheh; Mohammadi, Zohreh; Samadi, Fatemeh Yazdi; Samadikhah, Hamidreza; Taheritarigh, Sadegh; Tehrani, Niyousha Rafiee; Rafiee-Tehrani, Morteza

    2017-02-01

    Chitosan is a natural mucoadhesive, biodegradable, biocompatible and nontoxic polymer which has been used in pharmaceutical industry for a lot of purposes such as dissolution enhancing, absorption enhancing, sustained releasing and protein, gene or drug delivery. Two major disadvantages of chitosan are poor solubility in physiological pH and low efficiency for protein and gene delivery. In this study thiolated methylated N-(4-N,N-dimethylaminobenzyl) chitosan was prepared for the first time in order to improve the solubility and delivery properties of chitosan. This novel chitosan derivative was characterized using (1)H NMR, Ellman test, TGA and Zetasizer. Cell toxicity studies were performed on Human Embryonic Kidney 293 (Hek293) cell line using XTT method, to investigate the potential effect of this new derivative on cell viability. (1)H NMR results showed that all substitution reactions were successfully carried out. Zeta potential of new derivative at acidic and physiological pHs was greater than chitosan and it revealed an increase in solubility of the derivative. Furthermore, it had no significant cytotoxicity against Hek293 cell line in comparison to chitosan. These findings confirm that this new derivative can be introduced as a suitable compound for biomedical purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Safety evaluation of chitosan and chitosan acid salts from Panurilus argus lobster.

    PubMed

    Lagarto, Alicia; Merino, Nelson; Valdes, Odalys; Dominguez, Jesus; Spencer, Evelyn; de la Paz, Nilia; Aparicio, Guillermo

    2015-01-01

    Chitosan is a natural polymer with excellent properties such as biocompatibility, biodegradability, non-toxicity and adsorptive abilities. We obtained chitosan derived from Panurilus argus lobster shell and its lactate and acetate salts to introduce in pharmaceutical industry. We examined the single and repeated dose toxicity of chitosan and its lactate and acetate salts. Single oral doses of 2000 mg/kg were well tolerated for all three materials. In the repeat dose tests, animals treated with chitosan only show a slight erythrocytes increase. Variations in erythrocyte and leukocyte count and some biochemical parameters were observed in animals treated with chitosan acid salts. One g/kg orally was found to be the subacute NOAEL for chitosan due to the hematological findings observed were not considered adverse. Chitosans obtained from Panurilus argus lobster shell have low toxicity and may be safe in rats because it did not cause any lethality or changes in the general behavior in both the single and repeated dose toxicity studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Scanning electron microscopy and swelling test of shrimp shell chitosan and chitosan-RGD scaffolds

    NASA Astrophysics Data System (ADS)

    Mandacan, M. C.; Yuniastuti, M.; Amir, L. R.; Idrus, E.; Suniarti, D. F.

    2017-08-01

    Shrimp shell chitosan and chitosan-RGD scaffold membranes are produced to be biocompatible with tissue engineering. Nonetheless, their architectural properties have not yet been studied. Analyze the architectural properties of chitosan and chitosan-RGD scaffolds. Analyze pore count and size, interpore distance, and porosity (using SEM testing and ImageJ analysis) and water absorption (using a swelling test). The properties of the chitosan and chitosan-RGD scaffolds were as follows, respectively. The pore counts were 225 and 153; pore size, 171.4 μam and 180.2 μam interpore distance, 105.7 μam and 101.4 μam porosity, 22% and 10.2%; and water absorption, 9.1 mgH2O/mgScaffold and 19.3 mgH2O/mgScaffold. The shrimp shell chitosan-RGD membrane scaffold was found to have architectural properties that make it more conducive to use in tissue engineering.

  8. Improving the mechanical properties of chitosan-based heart valve scaffolds using chitosan fibers.

    PubMed

    Albanna, Mohammad Z; Bou-Akl, Therese H; Walters, Henry L; Matthew, Howard W T

    2012-01-01

    Chitosan is being widely studied for tissue engineering applications due to its biocompatibility and biodegradability. However, its use in load-bearing applications is limited due to low mechanical properties. In this study, we investigated the effectiveness of a chitosan fiber reinforcement approach to enhancing the mechanical properties of chitosan scaffolds. Chitosan fibers were fabricated using a solution extrusion and neutralization method and incorporated into porous chitosan scaffolds. The effects of fiber/scaffold mass ratio, fiber mechanical properties and fiber length on scaffold mechanical properties were studied. The results showed that incorporating fibers improved scaffold strength and stiffness in proportion to the fiber/scaffold mass ratio. A fiber-reinforced, heart valve scaffold achieved leaflet tensile strength values of 220±17 kPa, comparable to the radial values of human pulmonary valve leaflets. Additionally, the effects of 2 mm fibers were found to be up to threefold greater than 10 mm fibers at identical mass ratios. Heparin crosslinking of fibers produced a reduction in fiber strength, and thus failed to produce additional improvements to fiber-reinforced scaffold properties. Despite this reduction in fiber strength, heparin-modified fibers still improved the mechanical properties of reinforced scaffolds, but to a lesser extent than unmodified fibers. The results demonstrate that chitosan fiber reinforcement can be used to achieve porous chitosan scaffold strength approaching that of tissue, and that fiber length and mechanical properties are important parameters in defining the degree of mechanical improvement.

  9. Bioconjugation of quantum-dots with chitosan and N,N,N-trimethyl chitosan.

    PubMed

    Mansur, Herman S; Mansur, Alexandra A P; Curti, Elisabete; De Almeida, Mauro V

    2012-09-01

    Novel carbohydrate-based hybrids combining chitosan and chemically modified chitosan with CdS inorganic nanoparticles were designed and prepared via aqueous route at room temperature. N,N,N-trimethylchitosan (TM-chitosan) was synthesized aiming at substantially improving the water solubility of chitosan for producing stable colloidal systems. UV-vis spectroscopy, photoluminescence spectroscopy, Nuclear magnetic resonance spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the synthesis and the relative stability of biopolymer-capped CdS nanocrystals. The results have clearly indicated that chitosan and chitosan-derivative (TM-chitosan) were remarkably effective on nucleating and stabilizing CdS nanoparticles in aqueous suspensions. In addition, the CdS nanocrystals were produced in the so-called "quantum-size confinement regime", with the calculated average size below 3.5 nm and fluorescent activity in the visible range of the spectra. Therefore, a new single-step process was developed for the bioconjugation of quantum dots with water soluble chemically functionalized carbohydrates at room temperature for potential biomedical applications.

  10. Films, Buckypapers and Fibers from Clay, Chitosan and Carbon Nanotubes

    PubMed Central

    Higgins, Thomas M.; Warren, Holly; Panhuis, Marc in het

    2011-01-01

    The mechanical and electrical characteristics of films, buckypapers and fiber materials from combinations of clay, carbon nanotubes (CNTs) and chitosan are described. The rheological time-dependent characteristics of clay are maintained in clay–carbon nanotube–chitosan composite dispersions. It is demonstrated that the addition of chitosan improves their mechanical characteristics, but decreases electrical conductivity by three-orders of magnitude compared to clay–CNT materials. We show that the electrical response upon exposure to humid atmosphere is influenced by clay-chitosan interactions, i.e., the resistance of clay–CNT materials decreases, whereas that of clay–CNT–chitosan increases. PMID:28348277

  11. Hg(II) removal from water by chitosan and chitosan derivatives: a review.

    PubMed

    Miretzky, P; Cirelli, A Fernandez

    2009-08-15

    Mercury (Hg) is one of the most toxic heavy metals commonly found in the global environment. Its toxicity is related to the capacity of its compounds to bioconcentrate in organisms and to biomagnify through food chain. A wide range of adsorbents has been used for removing Hg(II) from contaminated water. Chitosan is obtained by alkaline deacetylation of chitin. The adsorption capacity of chitosan depends on the origin of the polysaccharide, and on the experimental conditions in the preparation, that determine the degree of deacetylation. A great number of chitosan derivatives have been obtained by crosslinking with glutaraldehyde or epichlorohydrin among others or by grafting new functional groups on the chitosan backbone with the aim of adsorbing Hg(II). The new functional groups are incorporated to change the pH range for Hg(II) sorption and/or to change the sorption sites in order to increase sorption selectivity. The chemical modification affords a wide range of derivatives with modified properties for specific applications. Hg(II) adsorption on chitosan or chitosan derivatives is now assumed to occur through several single or mixed interactions: chelation or coordination on amino groups in a pendant fashion or in combination with vicinal hydroxyl groups, electrostatic attraction in acidic media or ion exchange with protonated amino groups. This review reports the recent developments in the Hg(II) removal in waste water treatment, using chitosan and its derivatives in order to provide useful information about the different technologies. When possibly the adsorption capacity of chitosan and chitosan derivatives under different experimental conditions is reported to help to compare the efficacy of the Hg(II) removal process. A comparison with the adsorption capacity of other low-cost adsorbents is also tabled.

  12. Clinical Application of Chitosan in Dental Specialities.

    PubMed

    Wieckiewicz, Mieszko; Boening, Klaus W; Grychowska, Natalia; Paradowska-Stolarz, Anna

    2017-01-01

    Chitosan is a linear amino-polysaccharide and a natural polymer with a structure based on repetitive deacetylated and acetylated units randomly distributed. It is produced from chitin, one of the most common naturally occurring polysaccharides. Its numerous biomedical applications have been extensively described in the literature. It becomes more and more popular as a therapeutic agent and its use is constantly extended. Given its commonness, regenerative properties, easy chemical treatment, and biocompatibility, it might be used in the treatment of damaged oral cavity tissues. Due to its antimicrobial and regenerative-inducting properties as well as high biocompetency, chitosan is more and more frequently used in medicine and dentistry. It can be applied in all fields of dentistry including preventive dentistry, conservative dentistry, endodontics, surgery, periodontology, prosthodontics and orthodontics. Several data discussing the effectiveness of chitosan use on new bone formation are still inconclusive. The aim of the paper was to evaluate the applicability and biochemical impact of chitosan on oral health maintenance. Even though chitosan might find its adhibition in all dental specialities, it should still be considered as a potential allergen and thus further studies on this topic should be carried out. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Acrylated chitosan for mucoadhesive drug delivery systems.

    PubMed

    Shitrit, Yulia; Bianco-Peled, Havazelet

    2017-01-30

    A new mucoadhesive polymer was synthesized by conjugating chitosan to poly(ethylene glycol)diacrylate (PEGDA) via the Michael type reaction. The product was characterized using NMR. Higher PEGDA grafting efficacy was observed with low molecular weight PEGDA (0.7kDa), compared to long 10kDa PEGDA. The acrylation percentage was calculated based on the reaction of ninhydrin with chitosan, and supported the qualitative NMR findings. The adhesive properties were studied by tensile test and rotating system involving detachment of polymer tablets from a fresh intestine sample. Chitosan modified with high molecular weight PEGDA presented improvement in mucoadhesive properties compared to both non-modified and thiolated chitosan. On the molecular level, rheology measurements of polymer/mucin mixtures provided additional evidence of strong interaction between modified chitosan and mucin glycoproteins. This new polymer shows promise as a useful polymeric carrier matrix for delivery systems, which could provide prolonged residence time of the vehicle on the mucosa surface. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Pseudo-dry-spinning of chitosan.

    PubMed

    Notin, Laure; Viton, Christophe; Lucas, Jean-Michel; Domard, Alain

    2006-05-01

    A pseudo-dry-spinning process of chitosan without any use of organic solvent or cross-linking agent was studied. A highly deacetylated chitosan (degree of acetylation=2.7%) from squid-pens, with a high weight-average molecular weight (M(W)=540,000 g/mol) was used. The polymer was dissolved in an acetic acid aqueous solution in order to obtain a polymer concentration of 2.4% w/w with a stoichiometric protonation of the -NH(2) sites. The coagulation method consisted of subjecting the extruded monofilament to gaseous ammonia. The alkaline coagulation bath classically used in a wet-spinning process was therefore not useful. A second innovation dealt with the absence of any aqueous washing bath after coagulation. The gaseous coagulation was then directly followed by a drying step under hot air. When the chitosan monofilament coagulated in the presence of ammonia gas, ammonium acetate produced with the fiber could be hydrolyzed into acetic acid and ammonia, easily eliminated in their gaseous form during drying. The pseudo-dry-spinning process did not give rise to any strong degradation of polymer chains. After 2 months at ambient atmosphere, chitosan fibers could then be stored without any significant decrease in the M(W), which remained at a rather high value of 350,000 g/mol. The obtained chitosan fibers showed a smooth, regular and uniformly striated surface.

  15. Methacrylated glycol chitosan as a photopolymerizable biomaterial.

    PubMed

    Amsden, Brian G; Sukarto, Abby; Knight, Darryl K; Shapka, Stephen N

    2007-12-01

    Glycol chitosan is a derivative of chitosan that is soluble at neutral pH and possesses potentially useful biological properties. With the goal of obtaining biocompatible hydrogels for use as tissue engineering scaffolds or drug delivery depots, glycol chitosan was converted to a photopolymerizable prepolymer through graft methacrylation using glycidyl methacrylate in aqueous media at pH 9. N-Methacrylation was verified by both (1)H NMR and (13)C NMR. The degree of N-methacrylation, measured via (1)H NMR, was easily varied from 1.5% to approximately 25% by varying the molar ratio of glycidyl methacrylate to glycol chitosan and the reaction time. Using a chondrocyte cell line, the N-methacrylated glycol chitosan was found to be noncytotoxic up to a concentration of 1 mg/mL. The prepolymer was cross-linked in solution using UV light and Irgacure 2959 photoinitiator under various conditions to yield gels of low sol content ( approximately 5%), high equilibrium water content (85-95%), and thicknesses of up to 6 mm. Cross-polarization magic-angle spinning (13)C solid state NMR verified the complete conversion of the double bonds in the gel. Chondrocytes seeded directly onto the gel surface, populated the entirety of the gel and remained viable for up to one week. The hydrogels degraded slowly in vitro in the presence of lysozyme at a rate that increased as the cross-link density of the gels decreased.

  16. Chitosan inhibits premature browning in ground beef.

    PubMed

    Suman, S P; Mancini, R A; Joseph, P; Ramanathan, R; Konda, M K R; Dady, G; Yin, S

    2011-07-01

    Our objective was to evaluate the effect of chitosan on premature browning in refrigerated ground beef patties stored in different packaging systems. Ground beef patties (15% fat) with chitosan (1% w/w) or without chitosan (control) were individually packaged either in vacuum (VP), aerobic packaging (AP), carbon monoxide modified atmosphere packaging (LO-OX; 0.4% CO+19.6% CO(2)+80% N(2)), or high-oxygen modified atmosphere packaging (HI-OX; 80% O(2)+20% CO(2)), and stored for 0, 1, or 3 days at 1°C. At the conclusion of storage, raw surface redness was evaluated, patties were cooked to internal end-point temperatures of either 66°C or 71°C, and internal cooked color was measured. The incorporation of chitosan increased (P<0.05) the interior redness of patties stored in AP, VP, and LO-OX, but not in HI-OX. The results of the present study suggest that the incorporation of 1% chitosan minimizes premature browning in ground beef patties stored under AP, VP, and LO-OX.

  17. Strong adhesion and cohesion of chitosan in aqueous solutions

    PubMed Central

    Lee, Dong Woog; Lim, Chanoong; Israelachvili, Jacob N.; Hwang, Dong Soo

    2014-01-01

    Chitosan, a load-bearing biomacromolecule found in the exoskeletons of crustaceans and insects, is a promising biopolymer for the replacement of synthetic plastic compounds. Here, surface interactions mediated by chitosan in aqueous solutions, including the effects of pH and contact time, were investigated using a surface forces apparatus (SFA). Chitosan films showed an adhesion to mica for all tested pH ranges (3.0–8.5), achieving a maximum value at pH 3.0 after a contact time of 1 hr (Wad ~6.4 mJ/m2). We also found weak or no cohesion between two opposing chitosan layers on mica in aqueous buffer until the critical contact time for maximum adhesion (chitosan-mica) was reached. Strong cohesion (Wco ~8.5 mJ/m2) between the films was measured with increasing contact times up to 1 hr at pH 3.0, which is equivalent to ~60% of the strongest, previously reported, mussel underwater adhesion. Such time-dependent adhesion properties are most likely related to molecular or molecular group reorientations and interdigitations. At high pH (8.5), the solubility of chitosan changes drastically, causing the chitosan-chitosan (cohesion) interaction to be repulsive at all separation distances and contact times. The strong contact time and pH-dependent chitosan-chitosan cohesion and adhesion properties provide new insight into the development of chitosan based load-bearing materials. PMID:24138057

  18. Chitosan in Mucoadhesive Drug Delivery: Focus on Local Vaginal Therapy

    PubMed Central

    Andersen, Toril; Bleher, Stefan; Flaten, Gøril Eide; Tho, Ingunn; Mattsson, Sofia; Škalko-Basnet, Nataša

    2015-01-01

    Mucoadhesive drug therapy destined for localized drug treatment is gaining increasing importance in today’s drug development. Chitosan, due to its known biodegradability, bioadhesiveness and excellent safety profile offers means to improve mucosal drug therapy. We have used chitosan as mucoadhesive polymer to develop liposomes able to ensure prolonged residence time at vaginal site. Two types of mucoadhesive liposomes, namely the chitosan-coated liposomes and chitosan-containing liposomes, where chitosan is both embedded and surface-available, were made of soy phosphatidylcholine with entrapped fluorescence markers of two molecular weights, FITC-dextran 4000 and 20,000, respectively. Both liposomal types were characterized for their size distribution, zeta potential, entrapment efficiency and the in vitro release profile, and compared to plain liposomes. The proof of chitosan being both surface-available as well as embedded into the liposomes in the chitosan-containing liposomes was found. The capability of the surface-available chitosan to interact with the model porcine mucin was confirmed for both chitosan-containing and chitosan-coated liposomes implying potential mucoadhesive behavior. Chitosan-containing liposomes were shown to be superior in respect to the simplicity of preparation, FITC-dextran load, mucoadhesiveness and in vitro release and are expected to ensure prolonged residence time on the vaginal mucosa providing localized sustained release of entrapped model substances. PMID:25574737

  19. Strong adhesion and cohesion of chitosan in aqueous solutions.

    PubMed

    Lee, Dong Woog; Lim, Chanoong; Israelachvili, Jacob N; Hwang, Dong Soo

    2013-11-19

    Chitosan, a load-bearing biomacromolecule found in the exoskeletons of crustaceans and insects, is a promising biopolymer for the replacement of synthetic plastic compounds. Here, surface interactions mediated by chitosan in aqueous solutions, including the effects of pH and contact time, were investigated using a surface forces apparatus (SFA). Chitosan films showed an adhesion to mica for all tested pH ranges (3.0-8.5), achieving a maximum value at pH 3.0 after a contact time of 1 h (Wad ~ 6.4 mJ/m(2)). We also found weak or no cohesion between two opposing chitosan layers on mica in aqueous buffer until the critical contact time for maximum adhesion (chitosan-mica) was reached. Strong cohesion (Wco ~ 8.5 mJ/m(2)) between the films was measured with increasing contact times up to 1 h at pH 3.0, which is equivalent to ~60% of the strongest, previously reported, mussel underwater adhesion. Such time-dependent adhesion properties are most likely related to molecular or molecular group reorientations and interdigitations. At high pH (8.5), the solubility of chitosan changes drastically, causing the chitosan-chitosan (cohesion) interaction to be repulsive at all separation distances and contact times. The strong contact time and pH-dependent chitosan-chitosan cohesion and adhesion properties provide new insight into the development of chitosan-based load-bearing materials.

  20. Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease

    NASA Astrophysics Data System (ADS)

    Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

    2014-06-01

    Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-α in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.

  1. Synergistic antimicrobial activities of natural essential oils with chitosan films.

    PubMed

    Wang, Lina; Liu, Fei; Jiang, Yanfeng; Chai, Zhi; Li, Pinglan; Cheng, Yongqiang; Jing, Hao; Leng, Xiaojing

    2011-12-14

    The synergistic antimicrobial activities of three natural essential oils (i.e., clove bud oil, cinnamon oil, and star anise oil) with chitosan films were investigated. Cinnamon oil had the best antimicrobial activity among three oils against Escherichia coli , Staphylococcus aureus , Aspergillus oryzae , and Penicillium digitatum . The chitosan solution exhibited good inhibitory effects on the above bacteria except the fungi, whereas chitosan film had no remarkable antimicrobial activity. The cinnamon oil-chitosan film exhibited a synergetic effect by enhancing the antimicrobial activities of the oil, which might be related to the constant release of the oil. The cinnamon oil-chitosan film had also better antimicrobial activity than the clove bud oil-chitosan film. The results also showed that the compatibility of cinnamon oil with chitosan in film formation was better than that of the clove bud oil with chitosan. However, the incorporated oils modified the mechanical strengths, water vapor transmission rate, moisture content, and solubility of the chitosan film. Furthermore, chemical reaction took place between cinnamon oil and chitosan, whereas phase separation occurred between clove bud oil and chitosan.

  2. Multi-membrane chitosan hydrogels as chondrocytic cell bioreactors.

    PubMed

    Ladet, S G; Tahiri, K; Montembault, A S; Domard, A J; Corvol, M-T M

    2011-08-01

    We investigated the bioactivity of new chitosan-based multi-membrane hydrogel (MMH) architectures towards chondrocyte-like cells. The microstructure of the hydrogels constituting the membranes precludes any living cell penetration, whereas their lower scale architecture allows the protein diffusion. The biological behavior of chondrocytes implanted within the MMH inter-membrane spaces was studied for 45 days in culture. Chondrocytes formed cell aggregates and proliferated without loosing their chondrogenic phenotype as illustrated by collagen II and aggrecan expressions at the mRNA and protein levels. Cells produced neo-formed alcyan blue matrix proteins filling MMH interspaces. The HiF-2α/SOX9 pattern of expression suggested that the elevated chondrocytic phenotype in MMH could be related to a better hypoxic local environment than in classical culture conditions. Pro-inflammatory markers were not expressed during the period of culture. The low level of nitric oxide accumulation within the inter-membrane spaces and in the incubation medium implied that chitosan consumed nitrites produced by entrapped chondrocytes, in relation with the decrease of its molecular weight of 50%. Our data suggest that MMH structures may be considered as complex chondrocytic cell bioreactors; "active decoys of biological media", potentially promising for various biomedical applications like the inter-vertebral disk replacement. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Zwitterionic chitosan for the systemic treatment of sepsis

    PubMed Central

    Cho, Eun Jung; Doh, Kyung-Oh; Park, Jinho; Hyun, Hyesun; Wilson, Erin M.; Snyder, Paul W.; Tsifansky, Michael D.; Yeo, Yoon

    2016-01-01

    Severe sepsis and septic shock are life-threatening conditions, with Gram-negative organisms responsible for most sepsis mortality. Systemic administration of compounds that block the action of lipopolysaccharide (LPS), a constituent of the Gram-negative outer cell membrane, is hampered by their hydrophobicity and cationic charge, the very properties responsible for their interactions with LPS. We hypothesize that a chitosan derivative zwitterionic chitosan (ZWC), previously shown to suppress the production of pro-inflammatory cellular mediators in LPS-challenged macrophages, will have protective effects in an animal model of sepsis induced by systemic injection of LPS. In this study, we evaluate whether ZWC attenuates the fatal effect of LPS in C57BL/6 mice and investigate the mechanism by which ZWC counteracts the LPS effect using a PMJ2-PC peritoneal macrophage cell line. Unlike its parent compound with low water solubility, intraperitoneally administered ZWC is readily absorbed with no local residue or adverse tissue reaction at the injection site. Whether administered at or prior to the LPS challenge, ZWC more than doubles the animals’ median survival time. ZWC appears to protect the LPS-challenged organisms by forming a complex with LPS and thus attenuating pro-inflammatory signaling pathways. These findings suggest that ZWC have utility as a systemic anti-LPS agent. PMID:27412050

  4. Using nano-chitosan for harvesting microalga Nannochloropsis sp.

    PubMed

    Farid, Mohammad Sadegh; Shariati, Ahmad; Badakhshan, Amir; Anvaripour, Bagher

    2013-03-01

    In this study, chitosan and nano-chitosan were used as flocculants agents for harvesting microalga Nannochloropsis sp. chitosan was modified to nano-chitosan by crosslinking with sodium tripolyphosphate. The effects of type and dosage of flocculants and the pH of the culture were investigated on biomass recovery. Optimum dosages for both bio-flocculants were found. The results showed that the dosage of flocculant consumption decreases by 40% and biomass recovery increases by 9% when nano-chitosan instead of chitosan is used as flocculant agent. Also, the recycled water from the harvesting process was reused which increases the growth of microalgae by about 7%. Finally, the cost analysis of harvesting process showed the feasibility of using nano-chitosan as flocculation agent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Biodegradation of chitosan and its effect on metal bioavailability.

    PubMed

    Kamari, A; Pulford, I D; Hargreaves, J S J

    2015-02-01

    The microbial breakdown of chitosan, a fishery waste-based material, and its derivative cross-linked chitosans, in both non-contaminated and contaminated conditions was investigated in a laboratory incubation study. Biodegradation of chitosan and cross-linked chitosans was affected by the presence of heavy metals. Zn was more pronounced in inhibiting microbial activity than Cu and Pb. It was estimated that a longer period is required to complete the breakdown of the cross-linked chitosans (up to approximately 100 years) than unmodified chitosan (up to approximately 10 years). The influence of biodegradation on the bioavailable fraction of heavy metals was studied concurrently with the biodegradation trial. It was found that the binding behaviour of chitosan for heavy metals was not affected by the biodegradation process.

  6. Adsorption of carbon black using carboxymethyl chitosan in deinking process

    NASA Astrophysics Data System (ADS)

    Muryeti, Budimulyani, Estuti; Sinurat, Ellya

    2017-03-01

    The study about synthesis, characterization, and application carboxymethyl chitosan as adsorbent in deinking process was conducted. Adsorption of carbon black onto carboxymethyl chitosan has been investigated in a batch system. This research was conducted to obtain the adsorption capacity of carboxymethyl chitosan. The experiments were carried out to study the effect of carbon black concentration, contact time and dosage of carboxymethyl chitosan to the adsorption capacity of carboxymethyl chitosan. The optimum condition of carbon black adsorption was achieved at contact time of 60 min and weight doses of 1.0 g. The adsorption capacity of carboxymethyl chitosan was 14.34 mg/g and the adsorption effectivity was 70.54%. The result indicates that carboxymethyl chitosan could be used as adsorbent of carbon black in deinking process.

  7. Effect of chitosan coatings on postharvest green asparagus quality.

    PubMed

    Qiu, Miao; Jiang, Hengjun; Ren, Gerui; Huang, Jianying; Wang, Xiangyang

    2013-02-15

    Fresh postharvest green asparagus rapidly deteriorate due to its high respiration rate. The main benefits of edible active coatings are their edible characteristics, biodegradability and increase in food safety. In this study, the quality of the edible coatings based on 0.50%, 0.25% high-molecular weight chitosan (H-chitosan), and 0.50%, 0.25% low-molecular weight chitosan (L-chitosan) on postharvest green asparagus was investigated. On the basis of the results obtained, 0.25% H-chitosan and 0.50% L-chitosan treatments ensured lower color variation, less weight loss and less ascorbic acid, decrease presenting better quality of asparagus than other concentrations of chitosan treatments and the control during the cold storage, and prolonging a shelf life of postharvest green asparagus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Production and evaluation of dry alginate-chitosan microcapsules as an enteric delivery vehicle for probiotic bacteria.

    PubMed

    Cook, Michael T; Tzortzis, George; Charalampopoulos, Dimitris; Khutoryanskiy, Vitaliy V

    2011-07-11

    This study investigates the production of alginate microcapsules, which have been coated with the polysaccharide chitosan, and evaluates some of their properties with the intention of improving the gastrointestinal viability of a probiotic ( Bifidobacterium breve ) by encapsulation in this system. The microcapsules were dried by a variety of methods, and the most suitable was chosen. The work described in this Article is the first report detailing the effects of drying on the properties of these microcapsules and the viability of the bacteria within relative to wet microcapsules. The pH range over which chitosan and alginate form polyelectrolyte complexes was explored by spectrophotometry, and this extended into swelling studies on the microcapsules over a range of pHs associated with the gastrointestinal tract. It was shown that chitosan stabilizes the alginate microcapsules at pHs above 3, extending the stability of the capsules under these conditions. The effect of chitosan exposure time on the coating thickness was investigated for the first time by confocal laser scanning microscopy, and its penetration into the alginate matrix was shown to be particularly slow. Coating with chitosan was found to increase the survival of B. breve in simulated gastric fluid as well as prolong its release upon exposure to intestinal pH.

  9. High efficiency gene transfer using chitosan/DNA nanoparticles with specific combinations of molecular weight and degree of deacetylation.

    PubMed

    Lavertu, Marc; Méthot, Stephane; Tran-Khanh, Nicolas; Buschmann, Michael D

    2006-09-01

    Chitosan is a biodegradable natural polysaccharide that has shown potential for gene delivery, although the ideal molecular weight (MW) and degree of deacetylation (DDA) for this application have not been elucidated. To examine the influence of these parameters on gene transfer, we produced chitosans with different DDAs (98%, 92%, 80% and 72%) and depolymerized them with nitrous acid to obtain different MWs (150, 80, 40 and 10 kDa). We produced 64 formulations of chitosan/pDNA complexes (16 chitosans, 2 amine-to-phosphate (N:P) ratios of 5:1 and 10:1 and 2 transfection media pH of 6.5 and 7.1), characterized them for size and surface charge, and tested them for gene transfection in HEK 293 cells in vitro. Several formulations produced high levels of transgene expression while two conditions, 92-10-5 and 80-10-10 [DDA-MW-N:P ratio] at pH 6.5, showed equivalence to our best positive control. The results also revealed an important coupling between DDA and MW of chitosan in determining transgene expression. Maximum expression was obtained with a certain combination of DDA and MW that depended on N:P ratio and the pH, but similar expression levels could be achieved by simultaneously lowering MW and increasing DDA or lowering DDA and increasing MW, suggesting a predominant role of particle stability, through co-operative electrostatic binding, in determining transfection efficiency.

  10. Neodymium(III) complexation by amino-carbohydrates via a ligand-controlled hydrolysis mechanism.

    PubMed

    Levitskaia, Tatiana G; Chen, Yongsheng; Fulton, John L; Sinkov, Sergei I

    2011-07-28

    Chelation of Nd(3+) by D-glucosamine (DGA) and chitosan was investigated in solution at near-physiological pH and ionic strength. This research demonstrates the first example of the lanthanide ion heteroleptic hydroxo-carbohydrate complex in solution. Amino-carbohydrates DGA and chitosan suppressed formation of polynuclear Nd(3+) species at elevated pH.

  11. Chitosan/lecithin liposomal nanovesicles as an oral insulin delivery system.

    PubMed

    Al-Remawi, Mayyas; Elsayed, Amani; Maghrabi, Ibrahim; Hamaidi, Mohammad; Jaber, Nisrein

    2017-05-01

    In the present work, insulin-chitosan polyelectrolyte complexes associated to lecithin liposomes were investigated as a new carrier for oral delivery of insulin. The preparation was characterized in terms of particle size, zeta potential and encapsulation efficiency. Surface tension measurements revealed that insulin-chitosan polyelectrolyte complexes have some degree of hydrophobicity and should be added to lecithin liposomal dispersion and not the vice versa to prevent their adsorption on the surface. Stability of insulin was enhanced when it was associated to liposomes. Significant reduction of blood glucose levels was noticed after oral administration of liposomal preparation to streptozotocin diabetic rats compared to control. The hypoglycemic activity was more prolonged compared to subcutaneously administered insulin.

  12. One-step preparation of chitosan-coated cationic liposomes by an improved supercritical reverse-phase evaporation method.

    PubMed

    Otake, Katsuto; Shimomura, Takeshi; Goto, Toshihiro; Imura, Tomohiro; Furuya, Takeshi; Yoda, Satoshi; Takebayashi, Yoshihiro; Sakai, Hideki; Abe, Masahiko

    2006-04-25

    High-pressure carbon dioxide in contact with water dissolves to form carbonic acid, causing a decrease in pH. By use of these characteristics of a CO2/H2O biphasic system, chitosan-coated cationic liposomes of l-alpha-dipalmitoylphosphatidylcholine were successfully prepared by an improved supercritical reverse-phase evaporation (ISCRPE) method. Liposome-chitosan complexes carrying a positive charge were prepared in a single-step procedure without the use of acid or organic solvent, including ethanol. The maximum trapping efficiency of liposomes prepared by the ISCRPE method was 17%, with or without the addition of chitosan, compared to only 2% for liposomes prepared by the Bangham method. Furthermore, the liposomal dispersion was stable at room temperature in a sealed tube for over 30 days.

  13. Structural Characterization of Chitosan-Clay Nanocomposite

    NASA Astrophysics Data System (ADS)

    Paluszkiewicz, C.; Weselucha-Birczynska, A.; Stodolak, E.

    2010-08-01

    Novel materials originating from renowable sources mainly consist of biopolymers and their composites or nanocomposites. A typical material belonging to this group is chitosane (CS), which is a cationic natural polysaccharide that can be produced by alkaline N-deacetylation of chitine. Chitosane has a variety of applications in biomedical products, cosmetics, and food processing [1, 2].Organic-inorganic hybrid materials basing on chitosane and nanoclay (montmoryllonite, MMT) were characterized by the vibrational spectrocopy methods (Micro-Raman spectroscopy and FT-Raman spectroscopy) and the thermal analysis methods (TG, DSC). It was shown, that small amount on a nanofiller (MMT, 3 wt.%) used to modify the polymer matrix influences the structure of its polymeric chains.

  14. Chitosan films and blends for packaging material.

    PubMed

    van den Broek, Lambertus A M; Knoop, Rutger J I; Kappen, Frans H J; Boeriu, Carmen G

    2015-02-13

    An increased interest for hygiene in everyday life as well as in food, feed and medical issues lead to a strong interest in films and blends to prevent the growth and accumulation of harmful bacteria. A growing trend is to use synthetic and natural antimicrobial polymers, to provide non-migratory and non-depleting protection agents for application in films, coatings and packaging. In food packaging, antimicrobial effects add up to the barrier properties of the materials, to increase the shelf life and product quality. Chitosan is a natural bioactive polysaccharide with intrinsic antimicrobial activity and, due to its exceptional physicochemical properties imparted by the polysaccharide backbone, has been recognized as a natural alternative to chemically synthesized antimicrobial polymers. This, associated with the increasing preference for biofunctional materials from renewable resources, resulted in a significant interest on the potential for application of chitosan in packaging materials. In this review we describe the latest developments of chitosan films and blends as packaging material.

  15. Effect of chitosan molecular weight and composition on mucoadhesive properties of mangostin-loaded chitosan-alginate microparticles

    NASA Astrophysics Data System (ADS)

    Krisanti, Elsa; Aryani, Sri Dwi; Mulia, Kamarza

    2017-02-01

    The mucoadhesive properties of chitosan is suitable for extending the residence time of chitosan microparticles in the small intestine and colon. Microparticles prepared using the lowest molecular weight chitosan (62 kDa) showed the highest mucin adsorption of 55-84% and the highest zeta potential of +35.1 mV. Alginate-modified chitosan microparticles (chitosan to alginate mass ratio of 1:0.25) also showed good mucoadhesive properties with 51-79% mucin adsorption and zeta potential of +31.1 mV. The results show that the negatively charged alginate would disrupt the electrostatic interaction between the positively charged chitosan with the negatively charged mucin, and, a higher molecular weight chitosan with lower degree of deacetylation, will have a weaker interaction with mucin.

  16. Comparison and Characterisation of Regenerated Chitosan from 1-Butyl-3-methylimidazolium Chloride and Chitosan from Crab Shells.

    PubMed

    Islam, Saniyat; Arnold, Lyndon; Padhye, Rajiv

    2015-01-01

    Chitosan is a biopolymer derived from chitin which is naturally occurring in the exoskeleton of crustaceans. This paper reports dissolution and regeneration of chitosan by directly dissolving in an ionic liquid solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl). This will provide an ideal platform to solubilise these kinds of polymers to achieve the dissolution. The current study dissolved chitosan from crab shell utilising BMIMCl as a solvent and characterised the resultant regenerated polymer. The regenerated chitosan showed increased hydrogen bonding when characterised by Fourier transform infrared (FTIR) spectral analysis. In addition, the study also compared the characteristics of regenerated and generic chitosan. The regenerated chitosan was also evaluated for antimicrobial properties and showed to possess antibacterial features similar to the commercial grade. This method can be utilised in future for blending of polymers with chitosan in a dissolved phase.

  17. Herstellung von Chitosan und einige Anwendungen

    NASA Astrophysics Data System (ADS)

    Struszczyk, Marcin Henryk

    2001-05-01

    1. Die Deacetylierung von crabshell - Chitosan führte gleichzeitig zu einem drastischen Abfall der mittleren viscosimetrischen Molmasse ( Mv), insbesondere wenn die Temperatur und die Konzentration an NaOH erhöht werden. Diese Parameter beeinflussten jedoch nicht den Grad der Deacetylierung (DD). Wichtig ist jedoch die Quelle des Ausgangsmaterials: Chitin aus Pandalus borealis ist ein guter Rohstoff für die Herstellung von Chitosan mit niedrigem DD und gleichzeitig hoher mittlerer Mv, während Krill-Chitin (Euphausia superba) ein gutes Ausgangsmaterial zur Herstellung von Chitosan mit hohem DD und niedrigem Mv ist. Chitosan, das aus Insekten (Calliphora erythrocephala), unter milden Bedingungen (Temperatur: 100°C, NaOH-Konzentration: 40 %, Zeit: 1-2h ) hergestellt wurde, hatte die gleichen Eigenschaften hinsichtlich DD und Mv wie das aus Krill hergestellte Chitosan. Der Bedarf an Zeit, Energie und NaOH ist für die Herstellung von Insekten-Chitosan geringer als für crabshell-Chitosan vergleichbare Resultaten für DD und Mv. 2. Chitosan wurde durch den Schimmelpilz Aspergillus fumigatus zu Chitooligomeren fermentiert. Die Ausbeute beträgt 25%. Die Chitooligomere wurden mit Hilfe von HPLC und MALDI-TOF-Massenspektrmetrie identifiziert. Die Fermentationsmischung fördert die Immunität von Pflanzen gegen Bakterien und Virusinfektion. Die Zunahme der Immunität schwankt jedoch je nach System Pflanze-Pathogen. Die Fermentation von Chitosan durch Aspergillus fumigatus könnte eine schnelle und billige Methode zur Herstellung von Chitooligomeren mit guter Reinheit und Ausbeute sein. Eine partiell aufgereinigte Fermentationsmischung dieser Art könnte in der Landwirtschaft als Pathogeninhibitor genutzt werden. Durch kontrollierte Fermentation, die Chitooligomere in definierter Zusammensetzung (d.h. definierter Verteilung des Depolymerisationsgrades) liefert, könnte man zu Mischungen kommen, die für die jeweilige Anwendung eine optimale Bioaktivität besitzen. 3

  18. Solid polymer electrolyte from phosphorylated chitosan

    SciTech Connect

    Fauzi, Iqbal Arcana, I Made

    2014-03-24

    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component’s composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it’s characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10{sup −6} S/cm up to 6.01 × 10{sup −4} S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10{sup −3} S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  19. A DFT based analysis of adsorption of Hg(2+) ion on chitosan monomer and its citralidene and salicylidene derivatives: Prior to the removal of Hg toxicity.

    PubMed

    Hassan, Basila; Rajan, Vijisha K; Mujeeb, V M Abdul; K, Muraleedharan

    2017-06-01

    A Density functional theory based study of adsorption of the toxic metal Hg (II) ion by chitosan monomer and two of its derivatives; citralidene and salicylidene chitosan, has been performed. The effect of structural features on the stability of studied complexes has been analyzed by using Gaussian03 software package. All the possible conformations of these adsorbents were studied using the global minimum geometries. All the adsorbing sites were studied by placing the metal ion on the centroid of the atoms and the stable conformer of the adsorbent-metal ion complex was identified. Interaction between Hg (II) and the adsorbents is found to be electrostatic. Metal ion binding with nitrogen atom is stronger than that with oxygen atoms in all the cases as the charge density of nitrogen is enhanced on Schiff base formation. The advantage of derivatives over chitosan monomer is their stability in acidic media. ΔE value of the complexes are in the order SC-Hg (II)>chitosan-Hg (II)>CC-Hg (II) which indicates that the stability of complexes increases with increase in energy gap. The study reveals that aromatic Schiff base derivatives of chitosan is better for Hg(II) intake than aliphatic derivatives. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. An investigation into the use of chitosan for the removal of soluble silver from industrial wastewater

    SciTech Connect

    Lasko, C.L.; Hurst, M.P.

    1999-10-15

    Chitosan was examined as a means of removing soluble silver from industrial waste streams. Stirred-batch and column methods were used to remove free (hydrated) silver ion as well as the ammonia, thiocyanate, thiosulfate, and cyanide complexes of silver in simulated wastewater at an initial concentration of 50 ppm and in a pH range of 2--10. An actual sample of X-ray film development rinse water was also tested. Batch method results show 80--95% silver bound at pH 4--8 for Ag{sup +} and Ag(NH{sub 3}){sub 2}{sup +}, while 92% and 75% of Ag(S{sub 2}O{sub 3}){sub 2}{sup 2{minus}}, and Ag(SCN){sub 3}{sup 2{minus}}, respectively, were bound at pH 2. Using a column containing 0.500 g of chitosan, 160 bed volumes of Ag{sup +}, 875 bed volumes of Ag(NH{sub 3}){sub 2}{sup +}, 715 bed volumes of Ag(S{sub 2}O{sub 3}){sub 2}{sup 3{minus}}, and 190 bed volumes of Ag(SCN){sub 3}{sup 2{minus}} solution were treated before silver ion concentration in the effluent reached 5 ppm. Chitosan did not significantly bind Ag(CN){sub 2}{sup {minus}} at any pH tested. Chitosan treated 450 bed volumes of 40 ppm X-ray rinse water before effluent silver concentration reached 5 ppm. Capacity experiment results using the column method indicated 42 mg of silver bound per gram of chitosan. Four commercial resins, Amberlite IRA-67, IRA 458, IRC-718, and Duolite GT-73, were also tested as silver binding agents.

  1. Electrochemical and electrochromic properties of layer-by-layer films from WO(3) and chitosan.

    PubMed

    Huguenin, Fritz; Gonzalez, Ernesto R; Oliveira, Osvaldo N

    2005-07-07

    The design of improved materials for electrochromic applications now involves extensive use of novel composites, thus requiring an investigation of the mechanisms responsible for electrochromism in these structures. Using films of WO(3) and chitosan produced with the layer-by-layer (LBL) technique, we demonstrate that characteristics such as the number of electrochemical active sites (K), the molar absorption coefficient (epsilon), and the electrochromic efficiency (eta) can be obtained using the quadratic logistic equation (QLE). The complexation ability between chitosan and WO(3) allowed the growth of visually uniform multilayers of the composite, with the same amount of material adsorbed in each deposition cycle. By fitting the absorbance changes (DeltaA) resulting from the electronic intervalence transfer from W(V) to W(VI) sites in four-bilayer LBL films of WO(3)/chitosan and WO(3)/chitosan with ethanol in the precursor dispersion, K was estimated to be ca. 5.5 x 10(-8) mol cm(-2) and 3.6 x 10(-8) mol cm(-2), respectively. The molar absorption coefficient and electrochromic efficiency vary with the charge injected because of the saturation of W(V) sites and the dissipation and feedback effects implicit in the QLE associated with ion-network interactions, such as the proton trapping effect. The LBL film of WO(3)/chitosan showed a smaller molar absorption coefficient and electrochromic efficiency than that containing ethanol because of a greater proton trapping effect for the LBL film with no ethanol. This enhanced trapping effect was seen as a decrease in the electronic flux involved in intervalence transfer in electrochemical impedance spectroscopy experiments.

  2. Thiolated chitosan nanoparticles enhance anti-inflammatory effects of intranasally delivered theophylline

    PubMed Central

    Lee, Dong-Won; Shirley, Shawna A; Lockey, Richard F; Mohapatra, Shyam S

    2006-01-01

    Background Chitosan, a polymer derived from chitin, has been used for nasal drug delivery because of its biocompatibility, biodegradability and bioadhesiveness. Theophylline is a drug that reduces the inflammatory effects of allergic asthma but is difficult to administer at an appropriate dosage without causing adverse side effects. It was hypothesized that adsorption of theophylline to chitosan nanoparticles modified by the addition of thiol groups would improve theophylline absorption by the bronchial epithelium and enhance its anti-inflammatory effects. Objectives We sought to develop an improved drug-delivery matrix for theophylline based on thiolated chitosan, and to investigate whether thiolated chitosan nanoparticles (TCNs) can enhance theophylline's capacity to alleviate allergic asthma. Methods A mouse model of allergic asthma was used to test the effects of theophylline in vivo. BALB/c mice were sensitized to ovalbumin (OVA) and OVA-challenged to produce an inflammatory allergic condition. They were then treated intranasally with theophylline alone, chitosan nanoparticles alone or theophylline adsorbed to TCNs. The effects of theophylline on cellular infiltration in bronchoalveolar lavage (BAL) fluid, histopathology of lung sections, and apoptosis of lung cells were investigated to determine the effectiveness of TCNs as a drug-delivery vehicle for theophylline. Results Theophylline alone exerts a moderate anti-inflammatory effect, as evidenced by the decrease in eosinophils in BAL fluid, the reduction of bronchial damage, inhibition of mucus hypersecretion and increased apoptosis of lung cells. The effects of theophylline were significantly enhanced when the drug was delivered by TCNs. Conclusion Intranasal delivery of theophylline complexed with TCNs augmented the anti-inflammatory effects of the drug compared to theophylline administered alone in a mouse model of allergic asthma. The beneficial effects of theophylline in treating asthma may be enhanced

  3. FTIR studies of plasticized poly(vinyl alcohol)-chitosan blend doped with NH4NO3 polymer electrolyte membrane.

    PubMed

    Kadir, M F Z; Aspanut, Z; Majid, S R; Arof, A K

    2011-03-01

    Fourier transform infrared (FTIR) spectroscopy studies of poly(vinyl alcohol) (PVA), and chitosan polymer blend doped with ammonium nitrate (NH(4)NO(3)) salt and plasticized with ethylene carbonate (EC) have been performed with emphasis on the shift of the carboxamide, amine and hydroxyl bands. 1% acetic acid solution was used as the solvent. It is observed from the chitosan film spectrum that evidence of polymer-solvent interaction can be observed from the shifting of the carboxamide band at 1660 cm(-1) and the amine band at 1591 cm(-1) to 1650 and 1557 cm(-1) respectively and the shift of the hydroxyl band from 3377 to 3354 cm(-1). The hydroxyl band in the spectrum of PVA powder is observed at 3354 cm(-1) and is observed at 3343 cm(-1) in the spectrum of the PVA film. On addition of NH(4)NO(3) up to 30 wt.%, the carboxamide, amine and hydroxyl bands shifted from 1650, 1557 and 3354 cm(-1) to 1642, 1541 and 3348 cm(-1) indicating that the chitosan has complexed with the salt. In the PVA-NH(4)NO(3) spectrum, the hydroxyl band has shifted from 3343 to 3272 cm(-1) on addition of salt from 10 to 30 wt.%. EC acts as a plasticizing agent since there is no shift in the bands as observed in the spectrum of PVA-chitosan-EC films. The mechanism of ion migration is proposed for the plasticized and unplasticized PVA-chitosan-NH(4)NO(3) systems. In the spectrum of PVA-chitosan-NH(4)NO(3)-EC complex, the doublet CO stretching in EC is observed in the vicinity 1800 and 1700. This indicates that there is some interaction between the salt and EC.

  4. FTIR studies of plasticized poly(vinyl alcohol)-chitosan blend doped with NH 4NO 3 polymer electrolyte membrane

    NASA Astrophysics Data System (ADS)

    Kadir, M. F. Z.; Aspanut, Z.; Majid, S. R.; Arof, A. K.

    2011-03-01

    Fourier transform infrared (FTIR) spectroscopy studies of poly(vinyl alcohol) (PVA), and chitosan polymer blend doped with ammonium nitrate (NH 4NO 3) salt and plasticized with ethylene carbonate (EC) have been performed with emphasis on the shift of the carboxamide, amine and hydroxyl bands. 1% acetic acid solution was used as the solvent. It is observed from the chitosan film spectrum that evidence of polymer-solvent interaction can be observed from the shifting of the carboxamide band at 1660 cm -1 and the amine band at 1591 cm -1 to 1650 and 1557 cm -1 respectively and the shift of the hydroxyl band from 3377 to 3354 cm -1. The hydroxyl band in the spectrum of PVA powder is observed at 3354 cm -1 and is observed at 3343 cm -1 in the spectrum of the PVA film. On addition of NH 4NO 3 up to 30 wt.%, the carboxamide, amine and hydroxyl bands shifted from 1650, 1557 and 3354 cm -1 to 1642, 1541 and 3348 cm -1 indicating that the chitosan has complexed with the salt. In the PVA-NH 4NO 3 spectrum, the hydroxyl band has shifted from 3343 to 3272 cm -1 on addition of salt from 10 to 30 wt.%. EC acts as a plasticizing agent since there is no shift in the bands as observed in the spectrum of PVA-chitosan-EC films. The mechanism of ion migration is proposed for the plasticized and unplasticized PVA-chitosan-NH 4NO 3 systems. In the spectrum of PVA-chitosan-NH 4NO 3-EC complex, the doublet C dbnd O stretching in EC is observed in the vicinity 1800 and 1700. This indicates that there is some interaction between the salt and EC.

  5. Degradable copolymer based on amphiphilic N-octyl-N-quatenary chitosan and low-molecular weight polyethylenimine for gene delivery

    PubMed Central

    Liu, Chengchu; Zhu, Qing; Wu, Wenhui; Xu, Xiaolin; Wang, Xiaoyu; Gao, Shen; Liu, Kehai

    2012-01-01

    Background Chitosan shows particularly high biocompatibility and fairly low cytotoxicity. However, chitosan is insoluble at physiological pH. Moreover, it lacks charge, so shows poor transfection. In order to develop a new type of gene vector with high transfection efficiency and low cytotoxicity, amphiphilic chitosan was synthesized and linked with low-molecular weight polyethylenimine (PEI). Methods We first synthesized amphiphilic chitosan – N-octyl-N-quatenary chitosan (OTMCS), then prepared degradable PEI derivates by cross-linking low-molecular weight PEI with amphiphilic chitosan to produce a new polymeric gene vector (OTMCS–PEI). The new gene vector was characterized by various physicochemical methods. We also determined its cytotoxicity and gene transfecton efficiency in vitro and in vivo. Results The vector showed controlled degradation. It was very stable and showed excellent buffering capacity. The particle sizes of the OTMCS–PEI/DNA complexes were around 150–200 nm with proper zeta potentials from 10 mV to 30 mV. The polymer could protect plasmid DNA from being digested by DNase I at a concentration of 2.25 U DNase I/μg DNA. Furthermore, they were resistant to dissociation induced by 50% fetal bovine serum and 1100 μg/mL sodium heparin. OTMCS–PEI revealed lower cytotoxicity, even at higher doses. Compared with PEI 25 KDa, the OTMCS–PEI/DNA complexes also showed higher transfection efficiency in vitro and in vivo. Conclusion OTMCS–PEI was a potential candidate as a safe and efficient gene vector for gene therapy. PMID:23071395

  6. Chitosan biopolymer for fuel cell applications.

    PubMed

    Ma, Jia; Sahai, Yogeshwar

    2013-02-15

    Fuel cell is an electrochemical device which converts chemical energy stored in a fuel into electrical energy. Fuel cells have been receiving attention due to its potential applicability as a good alternative power source. Recently, cost-effective and eco-friendly biopolymer chitosan has been extensively studied as a material for membrane electrolytes and electrodes in low to intermediate temperature hydrogen polymer electrolyte fuel cell, direct methanol fuel cell, alkaline fuel cell, and biofuel cell. This paper reviews structure and property of chitosan with respect to its applications in fuel cells. Recent achievements and prospect of its applications have also been included. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. [Encapsulating hepatocytes with chitosan in physiological conditions].

    PubMed

    Zhu, Jianhang; Zhang, Bao; Yan, Xiluan; Lao, Xuejun; Yu, Hanry

    2006-10-01

    Prepared from 15.3% N-acetylated chitosan (FNC), half N-acetylated chitosan (HNC) possesses a good solubility in a weak basic solution, guaranteeing the formation of microcapsules by the coacervating reaction between HNC and methacrylic acid (MAA)-hydroxyethyl methacrylate (HEMA)-methyl methacrylate (MMA) (MAA-HEMA-MMA) terpolymer under physiological conditions. When hepatocytes were encapsulated in such 3-dimensional microenvironment, as compared to monolayer culture, cell functions, including P450 activity, urea production and albumin release, were well supported. The prepared microcapsules have good mechanical stability and permeability.

  8. Enteric Viral Surrogate Reduction by Chitosan.

    PubMed

    Davis, Robert; Zivanovic, Svetlana; Davidson, P Michael; D'Souza, Doris H

    2015-12-01

    Enteric viruses are a major problem in the food industry, especially as human noroviruses are the leading cause of nonbacterial gastroenteritis. Chitosan is known to be effective against some enteric viral surrogates, but more detailed studies are needed to determine the precise application variables. The main objective of this work was to determine the effect of increasing chitosan concentration (0.7-1.5% w/v) on the cultivable enteric viral surrogates, feline calicivirus (FCV-F9), murine norovirus (MNV-1), and bacteriophages (MS2 and phiX174) at 37 °C. Two chitosans (53 and 222 kDa) were dissolved in water (53 kDa) or 1% acetic acid (222 KDa) at 0.7-1.5%, and were then mixed with each virus to obtain a titer of ~5 log plaque-forming units (PFU)/mL. These mixtures were incubated for 3 h at 37 °C. Controls included untreated viruses in phosphate-buffered saline and viruses were enumerated by plaque assays. The 53 kDa chitosan at the concentrations tested reduced FCV-F9, MNV-1, MS2, and phi X174 by 2.6-2.9, 0.1-0.4, 2.6-2.8, and 0.7-0.9 log PFU/mL, respectively, while reduction by 222 kDa chitosan was 2.2-2.4, 0.8-1.0, 2.6-5.2, and 0.5-0.8 log PFU/mL, respectively. The 222 kDa chitosan at 1 and 0.7% w/v in acetic acid (pH 4.5) caused the greatest reductions of MS2 by 5.2 logs and 2.6 logs, respectively. Overall, chitosan treatments showed the greatest reduction of MS2, followed by FCV-F9, phi X174, and MNV-1. These two chitosans may contribute to the reduction of enteric viruses at the concentrations tested but would require use of other hurdles to eliminate food borne viruses.

  9. Study on the degradation of chitosan slurries

    NASA Astrophysics Data System (ADS)

    Martini, Benjamin; Dimida, Simona; De Benedetto, Egidio; Madaghiele, Marta; Demitri, Christian

    In the present work, we measured the degradation rate of different chitosan slurries. Several parameters were monitored such as temperature (25 °C, 37 °C, 50 °C); chitosan concentration (1% and 2% (w/V)); and polymer molecular weight. The samples were tested in dynamic sweep test mode. This test is able to provide a reliable estimation of viscosity variations of the slurries; in turn, these variations could be related to degradation rate of the system in the considered conditions. The resulting information is particularly important especially in applications in which there is a close relationship between physical properties and molecular structure.

  10. The role of mucoadhesion of trimethyl chitosan and PEGylated trimethyl chitosan nanocomplexes in insulin uptake.

    PubMed

    Jintapattanakit, Anchalee; Junyaprasert, Varaporn Buraphacheep; Kissel, Thomas

    2009-12-01

    The aim of this work was to investigate the role of mucoadhesion in the insulin uptake of nanocomplexes (NC) based of trimethyl chitosan (TMC) and poly(ethylene glycol) (PEG)-graft-TMC copolymers. Self-assembled insulin NC were prepared by polyelectrolyte complexation. The effects of PEGylation and positive charge density on mucoadhesion were assessed using a mucin assay and mucus-secreting HT29-MTX-E12 (E12) monolayers. The behaviors of corresponding insulin NC after adhesion to E12 were also established. All PEGylated TMC copolymers showed significantly higher levels of adhesion to mucus than unmodified TMC. The copolymer composed of 298 PEG chains per TMC macromolecules exhibited the highest level of mucoadhesion, being 3.4 times higher than TMC. The higher mucoadhesive properties of PEGylated TMC copolymers resulted from the synergistic effects of interpenetration of PEG chains into the mucus and electrostatic interaction between positive charged TMC and anionic glycoproteins present in the mucus layer. Compared to TMC, insulin NC based on PEGylated TMC copolymers demonstrated no evidence of insulin uptake improvement due to complete release of insulin from NC after adhering to mucus. CLSM revealed the localization of TMC and its corresponding insulin NC at cell surface membranes of E12.

  11. Chitosan Effects on Plant Systems

    PubMed Central

    Malerba, Massimo; Cerana, Raffaella

    2016-01-01

    Chitosan (CHT) is a natural, safe, and cheap product of chitin deacetylation, widely used by several industries because of its interesting features. The availability of industrial quantities of CHT in the late 1980s enabled it to be tested in agriculture. CHT has been proven to stimulate plant growth, to protect the safety of edible products, and to induce abiotic and biotic stress tolerance in various horticultural commodities. The stimulating effect of different enzyme activities to detoxify reactive oxygen species suggests the involvement of hydrogen peroxide and nitric oxide in CHT signaling. CHT could also interact with chromatin and directly affect gene expression. Recent innovative uses of CHT include synthesis of CHT nanoparticles as a valuable delivery system for fertilizers, herbicides, pesticides, and micronutrients for crop growth promotion by a balanced and sustained nutrition. In addition, CHT nanoparticles can safely deliver genetic material for plant transformation. This review presents an overview on the status of the use of CHT in plant systems. Attention was given to the research that suggested the use of CHT for sustainable crop productivity. PMID:27347928

  12. Macrophage polarization following chitosan implantation.

    PubMed

    Vasconcelos, Daniela P; Fonseca, Ana C; Costa, Madalena; Amaral, Isabel F; Barbosa, Mário A; Águas, Artur P; Barbosa, Judite N

    2013-12-01

    Macrophages are a key cell in the host response to implants and can be polarized into different phenotypes capable of inducing both detrimental and beneficial outcomes in tissue repair and remodeling, being important in tissue engineering and regenerative medicine. The objective of this study was to evaluate the macrophage response to 3D porous chitosan (Ch) scaffolds with different degrees of acetylation (DA, 5% and 15%). The M1/M2 phenotypic polarization profile of macrophages was investigated in vivo using a rodent air-pouch model. Our results show that the DA affects the macrophage response. Ch scaffolds with DA 5% induced the adhesion of lower numbers of inflammatory cells, being the M2 the predominant phenotypic profile among the adherent macrophages. In the inflammatory exudates F4/80(+)/CD206(+) cells (M2 macrophages) appeared in higher numbers then F4/80(+)/CCR7(+) cells (M1 macrophages), in addition, lower levels of pro-inflammatory cytokines together with higher levels of anti-inflammatory cytokines were found. Ch scaffolds with DA 15% showed opposite results, since M1 were the predominant macrophages both adherent to the scaffold and in the exudates, together with high levels of pro-inflammatory cytokines. In conclusion, Ch scaffolds with DA 5% induced a benign M2 anti-inflammatory macrophage response, whereas Ch scaffolds with DA 15% caused a macrophage M1 pro-inflammatory response.

  13. Preparation of fucoidan-shelled and genipin-crosslinked chitosan beads for antibacterial application.

    PubMed

    Yu, Shu-Huei; Wu, Shao-Jung; Wu, Jui-Yu; Wen, De-Yu; Mi, Fwu-Long

    2015-08-01

    In this study, a fucoidan-shelled chitosan bead was developed with the purpose of oral delivery of berberine to inhibit the growth of bacteria. The cross-linking level and swelling property of the beads were affected by the pH value and the composition of the genipin/fucoidan combined gelling agent. The drug release of the berberine-loaded beads was faster in simulated gastric fluid (pH 1.2) than those in simulated intestinal fluid (pH 7.4). Furthermore, a nanoparticles/beads complex system was developed by incorporation of berberine-loaded chitosan/fucoidan nanoparticles in the fucoidan-shelled chitosan beads. The nanoparticles/beads complex served as a drug carrier to delay the berberine release in simulated gastric fluid, with an estimated lag time of 2 h. Our results showed that the berberine-loaded beads and nanoparticles/beads complex could effectively inhibit the growth inhibition of common clinical pathogens, such as Staphylococcus aureus and Escherichia coli, and have the advantage of continually releasing berberine to inhibit the growth of the bacteria over 24 h.

  14. Chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol

    PubMed Central

    2012-01-01

    Background and the purpose of the study Carvedilol nonselective β-adrenoreceptor blocker, chemically (±)-1-(Carbazol-4-yloxy)-3-[[2-(o-methoxypHenoxy) ethyl] amino]-2-propanol, slightly soluble in ethyl ether; and practically insoluble in water, gastric fluid (simulated, TS, pH 1.1), and intestinal fluid (simulated, TS without pancreatin, pH 7.5) Compounds with aqueous solubility less than 1% W/V often represents dissolution rate limited absorption. There is need to enhance the dissolution rate of carvedilol. The objective of our present investigation was to compare chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol. Methods The different formulations were prepared by different methods like solvent change approach to prepare hydrosols, solvent evaporation technique to form solid dispersions and cogrind mixtures. The prepared formulations were characterized in terms of saturation solubility, drug content, infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), electron microscopy, in vitro dissolution studies and stability studies. Results The practical yield in case of hydrosols was ranged from 59.76 to 92.32%. The drug content was found to uniform among the different batches of hydrosols, cogrind mixture and solid dispersions ranged from 98.24 to 99.89%. There was significant improvement in dissolution rate of carvedilol with chitosan chlorhdyrate as compare to chitosan and explanation to this behavior was found in the differences in the wetting, solubilities and swelling capacity of the chitosan and chitosan salts, chitosan chlorhydrate rapidly wet and dissolve upon its incorporation into the dissolution medium, whereas the chitosan base, less water soluble, would take more time to dissolve. Conclusion This technique is scalable and valuable in manufacturing process in future for enhancement of dissolution of poorly water soluble drugs. PMID:23351907

  15. [Kinetics of in vitro drug release from chitosan and N-alkyl chitosan membranes].

    PubMed

    Li, M; Xin, M; Wang, Q; Yao, K

    2001-03-01

    By using the so-called "lag-time" method, we studied the effect of membrane thickness(h), initial drug concentration(Co) and flow rate(V) on the difusion coefficient(D) of model drug in membranes. The experiment indicates that D increases as h and v increase; D Keeps constant when C0 changes; Under the same condition, the D value of N-alkyl chitosan membrane is bigger than that of pure chitosan membrane.

  16. The preparation and antioxidant activity of the sulfanilamide derivatives of chitosan and chitosan sulfates.

    PubMed

    Zhong, Zhimei; Ji, Xia; Xing, Ronge; Liu, Song; Guo, Zhanyong; Chen, Xiaolin; Li, Pengcheng

    2007-06-01

    Chitosan (CS) and chitosan sulfates (CSS) with different molecular weight (Mw) were reacted with 4-acetamidobenzene sulfonyl chloride to obtain sulfanilamide derivatives of chitosan and chitosan sulfates (LSACS, HSACS, LSACSS, HSACSS). The preparation conditions such as different reaction time, temperature, solvent, and the molar ratio of reaction materials are discussed in this paper. Their structures were characterized by FTIR spectroscopy and elemental analyses. The antioxidant activities of the derivatives were investigated employing various established in vitro systems, such as hydroxyl-radical ((*)OH) superoxide anion (O2(*-)) scavenging and reducing power. All kinds of the compounds (HCS, LCS, HCSS, LCSS, HSACS, LSACS, HSACSS, LSACSS) showed stronger scavenging activity on hydroxyl radical than ascorbic acid (Vc). The inhibitory activities of the derivatives toward superoxide radical by the PMS-NADH system were obvious. The experiment showed that the superoxide radical scavenging effect of sulfanilamide derivatives of chitosan and chitosan sulfates was stronger than that of original CS and CSS. All of the derivatives were efficient in the reducing power. The results indicated that the sulfanilamide group were grafted on CS and CSS increased the reducing power of them obviously.

  17. Anti-inflammatory activity of chitosan nanoparticles carrying NF-κB/p65 antisense oligonucleotide in RAW264.7 macropghage stimulated by lipopolysaccharide.

    PubMed

    Ma, Li; Shen, Chuan-an; Gao, Lei; Li, Da-wei; Shang, Yu-ru; Yin, Kai; Zhao, Dong-xu; Cheng, Wen-feng; Quan, Dong-qin

    2016-06-01

    The purpose of this present study is to prepare NF-κB/p65 antisense oligonucleotide loaded chitosan nanoparticles (NPs) and evaluate their physicochemical characterization and antisense effects in RAW264.7 macrophages. Condensed nanoparticles with mean particle size of 128±16nm, average Zeta potential of 19.6±6.3mV and high entrapment efficiency (EE) of 98.6±0.11% were formed between NF-κB/p65 antisense gene (NAG) and chitosan by complex coacervation method. Trypan blue staining and MTT tests showed that NAG chitosan NPs had no toxic effect on RAW264.7 macrophages when the dose was no more than 20μg/mL. Confocal microscopy images showed that NAG chitosan NPs were capable to deliver NAG into cytoplasm of RAW264.7 macrophages and finally into nucleus. Real-time PCR tests verified that NAG chitosan NPs could significantly decrease the mRNA expression level of NF-κB/p65 and inflammatory cytokines including TNF-ɑ, IL-1 and IL-6. Accordingly, western blot study showed that NAG NPs uptaken in the cells could efficiently reversed the expression of NF-κB/p65 protein induced by LPS. At last, downstream release level of inflammatory factors including TNF-ɑ, IL-1 and IL-6 in LPS stimulated RAW264.7 macrophages was significantly decreased after treated by NAG chitosan NPs. It could be concluded that chitosan NPs were excellent delivery vectors to ferry the NAG into the cytoplasm and nucleus of macrophages. The NAG chitosan NPs might be a novel therapeutic apparatus for the treatment of LPS induced sepsis by inhibiting NF-κB-related pro-inflammatory cytokines secretion.

  18. Simultaneous depolymerization and decolorization of chitosan by ozone treatment.

    PubMed

    Seo, S; King, J M; Prinyawiwatkul, W

    2007-11-01

    Currently, depolymerization and decolorization of chitosan are achieved by chemical or enzymatic methods, which are time consuming and expensive. Ozone has been shown to be able to degrade macromolecules and remove pigments due to its high oxidation potential. In this study, the effects of ozone treatment on depolymerization and decolorization of chitosan were investigated. Crawfish chitosan was ozonated in water and acetic acid solution for 0, 5, 10, 15, and 20 min at room temperature with 12 wt% gas. In this study, the effects of ozone treatment on depolymerization and decolorization of chitosan were investigated by measuring the molecular weight, viscosity, and color of chitosan. The color of ozone-treated chitosan was analyzed using a Minolta spectrophotometer. The degree of deacetylation was determined by a colloid titration method. Molecular weight of ozone-treated chitosan in acetic acid solution decreased appreciably as the ozone treatment duration increased. Ozonation for 20 min reduced the molecular weight of the chitosan by 92% (104 kDa) compared to the untreated chitosan (1333 kDa) with a decrease in viscosity of the chitosan solution. Ozonation for 5 min markedly increased the whiteness of chitosan with a molecular weight of 432 kDa; however, further ozonation resulted in development of yellowness. In the case of the ozonation in water, there were no significant differences in the molecular weight and color between ozone-treated chitosans. This study showed that ozone can be used to modify molecular weight and remove pigments of chitosan without chemical use in a shorter time and with less cost.

  19. Stable emulsions prepared by self-assembly of hyaluronic acid and chitosan for papain loading.

    PubMed

    Zhao, Donghua; Wei, Wei; Zhu, Ye; Sun, Jianhua; Hu, Qiong; Liu, Xiaoya

    2015-04-01

    A simple, green and effective process is developed to fabricate hyaluronic acid (HA)/chitosan (CS) complex colloidal particles through electrostatic interactions. The obtained complexes can be used as biocompatible emulsifiers and novel potential carriers for papain loading. An HA/CS mass ratio of 2 is the optimal condition leading to the smallest Dh (420.9 nm). The complexes with eight different mass ratios are used to stabilize white oil/water emulsions. The structure of the complexes at the oil-water interface varies in response to the mass ratio and can be classified into two typical structures, similar to typical polymeric surfactants and solid particulate emulsifiers. Furthermore, papain is introduced into the complex systems. Formation of the papain/HA/CS complexes in a compact form can protect the enzyme. Here, a novel strategy is introduced to fabricate a biocompatible emulsion from the HA/CS complexes and demonstrate that the stable complex is a suitable enzyme delivery system.

  20. Chitosan-amylopectin/hydroxyapatite and chitosan-chondroitin sulphate/hydroxyapatite composite scaffolds for bone tissue engineering.

    PubMed

    Venkatesan, Jayachandran; Pallela, Ramjee; Bhatnagar, Ira; Kim, Se-Kwon

    2012-12-01

    Over the past few decades, artificial graft materials for bone tissue engineering are gaining much importance. In this study, tri-component scaffolds of chitosan/natural hydroxyapatite with chondroitin sulfate (chitosan-CS/HAp) and amylopectin (chitosan-AP/HAp) have been developed for the first time via freeze-drying method and were characterized physicochemically for bone grafting substitutes. Chemical interactions and dispersion of HAp, CS and AP in the chitosan matrix have been evaluated by various analytical techniques. The porosity and water uptake/retention ability of these composite scaffolds decreased whereas thermal stability increased when compared to the chitosan scaffold. The pore size of the chitosan/HAp, chitosan-CS/HAp and chitosan-AP/HAp scaffolds varied from 60 to 180 μm, 60 to 400 μm and 80 to 500 μm, respectively. Cell proliferation, alkaline phosphatase activity and type-1 collagen production was evaluated in vitro using MG-63 cell line, which was observed to be higher in the composite scaffolds. Excellent interconnected porosity, controlled biodegradation and enhanced cell proliferation of the novel chitosan-CS/HAp and chitosan-AP/HAp scaffolds suggests that these scaffolds are promising biomaterials for bone tissue engineering. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. The effect of chitosan and whey proteins-chitosan films on the growth of Penicillium expansum in apples.

    PubMed

    Simonaitiene, Dovile; Brink, Ieva; Sipailiene, Ausra; Leskauskaite, Daiva

    2015-05-01

    Penicillium expansum causes a major post-harvest disease of apples. The aim of this study was to investigate the inhibition effect of chitosan and whey proteins-chitosan films containing different amounts of quince and cranberry juice against P. expansum on the simulation medium and on apples. The mechanical properties of films were also evaluated. The presence of cranberry and quince juice in the composition of chitosan and whey proteins-chitosan films caused a significant (P ≤ 0.05) increase in elasticity and decrease in tensile strength of films. Chitosan and whey proteins-chitosan films with quince and cranberry juice demonstrated a significant (P ≤ 0.05) inhibition effect against P. expansum growth on the simulated medium and apples. The presence of cranberry juice in the composition of chitosan and whey proteins-chitosan films resulted in a longer lag phase and a lower P. expansum growth rate on the simulation medium in comparison with films made with the addition of quince juice. These differences were not evident when experiment was conducted with apples. Addition of quince and cranberry juice to the chitosan and whey proteins-chitosan films as natural antifungal agents has some potential for prolonging the shelf life of apples. © 2014 Society of Chemical Industry.

  2. Ultrathin Chitosan Films with Tailored Properties

    NASA Astrophysics Data System (ADS)

    Murray, Chris; Stukalov, Oleg; Dutcher, John

    2004-03-01

    Chitosan is a biodegradable polysaccharide derived from seashell waste products. Though abundant, the industrial use of this polymer has up until recently been limited to water treatment products. The high water absorbency and biocompatibility of chitosan have enabled its use as a hydrogel in specialty applications such as wound dressings and drug delivery systems. The most convenient method of processing chitosan is solution casting to form films, since the polymer is soluble in weakly acidic solvents. Based on previous work with synthetic polymers, we have developed a protocol for preparing thin, uniform films of chitosan by spincoating from solution onto silicon substrates. Films with thicknesses between 30 and 600 nm (as measured by ellipsometry) and rms roughnesses of less than 1 nm (as measured by atomic force microscopy) were prepared. After preparation, these films quickly absorb water in the presence of high humidity. Heating of the films to high temperature causes large reductions in film thickness h and index of refraction n. After cooling the films to room temperature, h and n remain constant in the presence of high humidity. Using this simple procedure, we are able to produce films with tailored thickness, optical properties and water absorbency.

  3. Thermochemical characteristics of chitosan-polylactide copolymers

    NASA Astrophysics Data System (ADS)

    Goruynova, P. E.; Larina, V. N.; Smirnova, N. N.; Tsverova, N. E.; Smirnova, L. A.

    2016-05-01

    The energies of combustion of chitosan and its block-copolymers with different polylactide contents are determined in a static bomb calorimeter. Standard enthalpies of combustion and formation are calculated for these substances. The dependences of the thermochemical characteristics on block-copolymer composition are determined and discussed.

  4. Photochemical tissue bonding with chitosan adhesive films.

    PubMed

    Lauto, Antonio; Mawad, Damia; Barton, Matthew; Gupta, Abhishek; Piller, Sabine C; Hook, James

    2010-09-08

    Photochemical tissue bonding (PTB) is a promising sutureless technique for tissue repair. PTB is often achieved by applying a solution of rose bengal (RB) between two tissue edges, which are irradiated by a green laser to crosslink collagen fibers with minimal heat production. In this study, RB has been incorporated in chitosan films to create a novel tissue adhesive that is laser-activated. Adhesive films, based on chitosan and containing ~0.1 wt% RB were manufactured and bonded to calf intestine by a solid state laser (λ = 532 nm, Fluence~110 J/cm2, spot size~0.5 cm). A single-column tensiometer, interfaced with a personal computer, tested the bonding strength. K-type thermocouples recorded the temperature (T) at the adhesive-tissue interface during laser irradiation. Human fibroblasts were also seeded on the adhesive and cultured for 48 hours to assess cell growth. The RB-chitosan adhesive bonded firmly to the intestine with adhesion strength of 15 ± 2 kPa, (n = 31). The adhesion strength dropped to 0.5 ± 0.1 (n = 8) kPa when the laser was not applied to the adhesive. The average temperature of the adhesive increased from 26°C to 32°C during laser exposure. Fibroblasts grew confluent on the adhesive without morphological changes. A new biocompatible chitosan adhesive has been developed that bonds photochemically to tissue with minimal temperature increase.

  5. Chitosan Adhesive Films for Photochemical Tissue Bonding

    NASA Astrophysics Data System (ADS)

    Lauto, Antonio; Mawad, Damia; Barton, Matthew; Piller, Sabine C.; Longo, Leonardo

    2011-08-01

    Photochemical tissue bonding (PTB) is a promising sutureless technique for tissue repair. PTB is often achieved by applying a solution of rose bengal (RB) between two tissue edges, which are irradiated by a green laser to crosslink collagen fibers with minimal heat production. In this study, RB has been incorporated in chitosan films to create a novel tissue adhesive that is laser-activated. Materials and Methods. Adhesive films, based on chitosan and containing ˜0.1wt% RB were manufactured and bonded to calf intestine by a solid state laser (wavelength = 532 nm, Fluence ˜110 J/cm2, spot size ˜5 mm)