The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Mingwei Lee - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of cinnamated Polygalacturonic Acid for biomedical application
中山醫學雜誌, 2013Co-Authors: Shihhsien Chang, Kaisung Wang, Wengin Leong, Mingwei LeeAbstract:Polygalacturonic Acid (PGA) with varying degrees of cinnamated subsititution were synthesized. 6.2- 15.1% of the D-galacturonic residues of the cinnamated PGA (PGA-Cin) reacted with cinnamate groups. An investigation of the photochemical properties revealed that the photoconversion rate and rate constant of PGA-Cin was 80% and 5.95×10^(-3)s^(-1) after UV irradiation. The anti-adhesion films prepared from PGA-Cin exhibited high gel content and were found to efficacious in inhibiting bacterial growth. We evaluated their biocompatibility and anti-adhesion capability in both in vitro and in vivo experiments. The PGA-Cin films did not show any evidence of cytotoxic effects, as they did not induce any significant increase of cytoplasmic LDH release from the L929 cells in contact with them. When implanted into rats, the PGA-Cin films (anti-adhesion incidence 80.9%) exhibited more anti-adhesion potential than the commercial product Seprafilm^(TM) (anti-adhesion incidence 47.6%).
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Synthesis of a disulfide cross-linked Polygalacturonic Acid hydrogel for biomedical applications
Journal of Materials Science: Materials in Medicine, 2013Co-Authors: Hsiuhui Peng, Yi-min Chen, Chen-i Lee, Mingwei LeeAbstract:Polygalacturonic Acid (PGA) hydrogel cross-linked via disulfide bonds was synthesized using a thiol oxidation reaction. PGA was grafted with cysteine to yield thiolated PGA (denoted PGA_cys). Per gram, PGA-conjugated cysteine was 725 ± 77 μmol, and the degree of modification was 16.24 %. A PGA_cys hydrogel film was fabricated under physiological conditions, with gel content 91.6 % and water content 43.3 %. The PGA_cys hydrogel was used as a drug carrier for rosmarinic Acid (RA) (denoted PGA_cys/RA) and to prevent postsurgical adhesion. The in vitro dynamic release behavior of RA from the PGA_cys hydrogel was analyzed. The profiles showed that 80 % of the total RA was released from the hydrogel within 15 min, followed by zero-order kinetic release. Animal implant studies showed that PGA_cys and PGA_cys/RA hydrogel films reduced adhesion incidence by over 90 %, significantly higher than did Hyaluronate/Carboxymethylcellulose (analogous Seprafilm™) (42 %). The PGA_cys/RA hydrogel film also reduced the early inflammatory reaction.
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Covalently crosslinked hyaluronan–Polygalacturonic Acid polymer as the drug carrier and its application in surgery
Iranian Polymer Journal, 2013Co-Authors: Hsiuhui Peng, Pin-jan Liu, I-min Chen, Mingwei LeeAbstract:The composite material based on the hyaluronan (HA) and Polygalacturonic Acid (PGA) was synthesized for tissue anti-adhesion. HA and PGA were cross-linked covalently by disulfide bonds through thiol oxidation reaction. HA and PGA were grafted with cysteine to yield thiolated HA (HA_cys, with thiol content of 337 ± 72 μmol/g) and PGA (PGA_cys, with thiol content of 752 ± 77 μmol/g), respectively. A HA_cys–PGA_cys film was fabricated under physiological conditions, with gel content of 84.8 ± 1.7 % and water content of 46.9 ± 2.2 %. The HA_cys–PGA_cys film was used as the anti-inflammatory drug (rosmarinic Acid (RA)) carrier to prevent postsurgical adhesion. The in vitro dynamic release behavior of RA from the HA_cys–PGA_cys film was analyzed. The RA-entrapped film displayed release profile with an initial burst about 80 % of loaded RA in the early stage. The late phase release of RA from the HA_cys–PGA_cys film after 24 h followed the zero order ( R ^2 = 0.978). Animal implant studies of the HA_cys–PGA_cys and HA_cys–PGA_cyswith rosmarinic Acid (HA_cys–PGA_cys/RA) films reduced adhesion incidences by 83 and 92 %, respectively. To evaluate the efficiency of a combination of physical barriers and an RA anti-inflammatory drug, white blood cell counts from histological sections was done on day 3 after surgery. The results showed that the number of WBCs in the section with the HA_cys–PGA_cys/RA film decreased by 26.8 % compared with the section with HA_cys–PGA_cys film. The newly developed HA_cys–PGA_cys composite polymer showed great potential as the drug carrier and also for postoperative adhesion prevention.
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COVALENTLY CROSSLINKED HYALURONAN-Polygalacturonic Acid POLYMER AS THE DRUG CARRIER AND ITS APPLICATION IN SURGERY
Iranian Polymer Journal, 2013Co-Authors: Hsiuhui Peng, Pin-jan Liu, I-min Chen, Mingwei LeeAbstract:The composite material based on the hyaluronan (HA) and Polygalacturonic Acid (PGA) was synthesized for tissue anti-adhesion. HA and PGA were cross-linked covalently by disulfide bonds through thiol oxidation reaction. HA and PGA were grafted with cysteine to yield thiolated HA (HAcys, with thiol content of 337 ± 72 μmol/g) and PGA (PGAcys, with thiol content of 752 ± 77 μmol/g), respectively. A HAcys–PGAcys film was fabricated under physiological conditions, with gel content of 84.8 ± 1.7 % and water content of 46.9 ± 2.2 %. The HAcys–PGAcys film was used as the anti-inflammatory drug (rosmarinic Acid (RA)) carrier to prevent postsurgical adhesion. The in vitro dynamic release behavior of RA from the HAcys–PGAcys film was analyzed. The RA-entrapped film displayed release profile with an initial burst about 80 % of loaded RA in the early stage. The late phase release of RA from the HAcys–PGAcys film after 24 h followed the zero order (R 2 = 0.978). Animal implant studies of the HAcys–PGAcys and HAcys–PGAcyswith rosmarinic Acid (HAcys–PGAcys/RA) films reduced adhesion incidences by 83 and 92 %, respectively. To evaluate the efficiency of a combination of physical barriers and an RA anti-inflammatory drug, white blood cell counts from histological sections was done on day 3 after surgery. The results showed that the number of WBCs in the section with the HAcys–PGAcys/RA film decreased by 26.8 % compared with the section with HAcys–PGAcys film. The newly developed HAcys–PGAcys composite polymer showed great potential as the drug carrier and also for postoperative adhesion prevention.
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preparation and characterization of Polygalacturonic Acid rosmarinic Acid membrane crosslinked by short chain hyaluronate for preventing postoperative abdominal adhesion
Carbohydrate Polymers, 2012Co-Authors: Mingwei Lee, Hsiuhui Peng, Tzi-peng Yang, Jia-wei ChenAbstract:Abstract The most used materials for anti tissue adhesion after surgery are polymeric membranes. In this study, a short chain hyaluronate (sHA)-crosslinked Polygalacturonic Acid (PGA) membrane containing rosmarinic Acid (PGA/RA membrane) was prepared and characterized. The in vitro dynamic release behavior of RA from the PGA membranes was analyzed. The profiles showed 70% of the total RA released from the membrane after 5 days. The best-fitting mathematical model for RA release from the PGA membrane was the Korsmeyer–Peppas model ( r 2 = 0.996). In vivo evaluation of anti-postoperative tissue adhesion showed that use of a PGA/RA membrane reduced adhesion incidence by 90%. Anti-inflammatory analysis results showed that on the third day following surgery, the number of neutrophils and macrophages in the PGA-treated group (without RA) was 2.1 and 2.4 times that of the PGA/RA-treated group, respectively. Thus, the PGA/RA membrane developed in this study has anti-postoperative tissue adhesion and anti-inflammatory capabilities.
Hsiuhui Peng - One of the best experts on this subject based on the ideXlab platform.
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Ibuprofen-conjugated hyaluronate/Polygalacturonic Acid hydrogel for the prevention of epidural fibrosis
Journal of biomaterials applications, 2016Co-Authors: Chengyi Lin, Hsiuhui Peng, Meihsiu Chen, Juisheng Sun, Tseying Liu, Chih-ju Chang, Minghong ChenAbstract:The formation of fibrous tissue is part of the natural healing response following a laminectomy. Severe scar tissue adhesion, known as epidural fibrosis, is a common cause of failed back surgery syndrome. In this study, by combining the advantages of drug treatment with a physical barrier, an ibuprofen-conjugated crosslinkable Polygalacturonic Acid and hyaluronic Acid hydrogel was developed for epidural fibrosis prevention. Conjugation was confirmed and measured by 1D(1)H NMR spectroscopy.In vitroanalysis showed that the ibuprofen-conjugated Polygalacturonic Acid-hyaluronic Acid hydrogel showed low cytotoxicity. In addition, the conjugated ibuprofen decreased prostaglandin E2production of the lipopolysaccharide-induced RAW264.7 cells. Histological data inin vivostudies indicated that the scar tissue adhesion of laminectomized male adult rats was reduced by the application of our ibuprofen-conjugated Polygalacturonic Acid-hyaluronic Acid hydrogel. Its use also reduced the population of giant cells and collagen deposition of scar tissue without inducing extensive cell recruitment. The results of this study therefore suggest that the local delivery of ibuprofenviaa Polygalacturonic Acid-hyaluronic Acid-based hydrogel reduces the possibility of epidural fibrosis.
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ibuprofen conjugated hyaluronate Polygalacturonic Acid hydrogel for the prevention of epidural fibrosis
Journal of Biomaterials Applications, 2016Co-Authors: Chengyi Lin, Hsiuhui Peng, Meihsiu Chen, Juisheng Sun, Tseying Liu, Chih-ju Chang, Minghong ChenAbstract:The formation of fibrous tissue is part of the natural healing response following a laminectomy. Severe scar tissue adhesion, known as epidural fibrosis, is a common cause of failed back surgery syndrome. In this study, by combining the advantages of drug treatment with a physical barrier, an ibuprofen-conjugated crosslinkable Polygalacturonic Acid and hyaluronic Acid hydrogel was developed for epidural fibrosis prevention. Conjugation was confirmed and measured by 1D(1)H NMR spectroscopy.In vitroanalysis showed that the ibuprofen-conjugated Polygalacturonic Acid-hyaluronic Acid hydrogel showed low cytotoxicity. In addition, the conjugated ibuprofen decreased prostaglandin E2production of the lipopolysaccharide-induced RAW264.7 cells. Histological data inin vivostudies indicated that the scar tissue adhesion of laminectomized male adult rats was reduced by the application of our ibuprofen-conjugated Polygalacturonic Acid-hyaluronic Acid hydrogel. Its use also reduced the population of giant cells and collagen deposition of scar tissue without inducing extensive cell recruitment. The results of this study therefore suggest that the local delivery of ibuprofenviaa Polygalacturonic Acid-hyaluronic Acid-based hydrogel reduces the possibility of epidural fibrosis.
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in situ forming hydrogel composed of hyaluronate and Polygalacturonic Acid for prevention of peridural fibrosis
Journal of Materials Science: Materials in Medicine, 2015Co-Authors: Chengyi Lin, Hsiuhui Peng, Meihsiu Chen, Juisheng Sun, Tseying Liu, Minghong ChenAbstract:Hyaluronic Acid-based hydrogels can reduce postoperative adhesion. However, the long-term application of hyaluronic Acid is limited by tissue mediated enzymatic degradation. To overcome this limitation, we developed a Polygalacturonic Acid and hyaluronate composite hydrogel by Schiff's base crosslinking reaction. The Polygalacturonic Acid and hyaluronate composite hydrogels had short gelation time (less than 15 s) and degraded by less than 50 % in the presence of hyaluronidase for 7 days. Cell adhesion and migration assays showed Polygalacturonic Acid and hyaluronate composite hydrogels prevented fibroblasts from adhesion and infiltration into the hydrogels. Compared to hyaluronate hydrogels and commercial Medishield™ gels, Polygalacturonic Acid and hyaluronate composite hydrogel was not totally degraded in vivo after 4 weeks. In the rat laminectomy model, Polygalacturonic Acid and hyaluronate composite hydrogel also had better adhesion grade and smaller mean area of fibrous tissue formation over the saline control and hyaluronate hydrogel groups. Polygalacturonic Acid and hyaluronate composite hydrogel is a system that can be easy to use due to its in situ cross-linkable property and potentially promising for adhesion prevention in spine surgeries.
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Synthesis of a disulfide cross-linked Polygalacturonic Acid hydrogel for biomedical applications
Journal of Materials Science: Materials in Medicine, 2013Co-Authors: Hsiuhui Peng, Yi-min Chen, Chen-i Lee, Mingwei LeeAbstract:Polygalacturonic Acid (PGA) hydrogel cross-linked via disulfide bonds was synthesized using a thiol oxidation reaction. PGA was grafted with cysteine to yield thiolated PGA (denoted PGA_cys). Per gram, PGA-conjugated cysteine was 725 ± 77 μmol, and the degree of modification was 16.24 %. A PGA_cys hydrogel film was fabricated under physiological conditions, with gel content 91.6 % and water content 43.3 %. The PGA_cys hydrogel was used as a drug carrier for rosmarinic Acid (RA) (denoted PGA_cys/RA) and to prevent postsurgical adhesion. The in vitro dynamic release behavior of RA from the PGA_cys hydrogel was analyzed. The profiles showed that 80 % of the total RA was released from the hydrogel within 15 min, followed by zero-order kinetic release. Animal implant studies showed that PGA_cys and PGA_cys/RA hydrogel films reduced adhesion incidence by over 90 %, significantly higher than did Hyaluronate/Carboxymethylcellulose (analogous Seprafilm™) (42 %). The PGA_cys/RA hydrogel film also reduced the early inflammatory reaction.
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Covalently crosslinked hyaluronan–Polygalacturonic Acid polymer as the drug carrier and its application in surgery
Iranian Polymer Journal, 2013Co-Authors: Hsiuhui Peng, Pin-jan Liu, I-min Chen, Mingwei LeeAbstract:The composite material based on the hyaluronan (HA) and Polygalacturonic Acid (PGA) was synthesized for tissue anti-adhesion. HA and PGA were cross-linked covalently by disulfide bonds through thiol oxidation reaction. HA and PGA were grafted with cysteine to yield thiolated HA (HA_cys, with thiol content of 337 ± 72 μmol/g) and PGA (PGA_cys, with thiol content of 752 ± 77 μmol/g), respectively. A HA_cys–PGA_cys film was fabricated under physiological conditions, with gel content of 84.8 ± 1.7 % and water content of 46.9 ± 2.2 %. The HA_cys–PGA_cys film was used as the anti-inflammatory drug (rosmarinic Acid (RA)) carrier to prevent postsurgical adhesion. The in vitro dynamic release behavior of RA from the HA_cys–PGA_cys film was analyzed. The RA-entrapped film displayed release profile with an initial burst about 80 % of loaded RA in the early stage. The late phase release of RA from the HA_cys–PGA_cys film after 24 h followed the zero order ( R ^2 = 0.978). Animal implant studies of the HA_cys–PGA_cys and HA_cys–PGA_cyswith rosmarinic Acid (HA_cys–PGA_cys/RA) films reduced adhesion incidences by 83 and 92 %, respectively. To evaluate the efficiency of a combination of physical barriers and an RA anti-inflammatory drug, white blood cell counts from histological sections was done on day 3 after surgery. The results showed that the number of WBCs in the section with the HA_cys–PGA_cys/RA film decreased by 26.8 % compared with the section with HA_cys–PGA_cys film. The newly developed HA_cys–PGA_cys composite polymer showed great potential as the drug carrier and also for postoperative adhesion prevention.
Dinesh R. Katti - One of the best experts on this subject based on the ideXlab platform.
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AFM and Nanoindentation Studies of Bone Nodules on Chitosan-Polygalacturonic Acid-Hydroxyapatite Nanocomposites
Cmes-computer Modeling in Engineering & Sciences, 2012Co-Authors: Rohit Khanna, Dinesh R. Katti, Kalpana S. KattiAbstract:Abstract: Here we report a new in situ nanoindentation technique developed toevaluate the composite mechanical behavior of cell-biomaterial construct underphysiological conditions over the time scale of bone nodule generation. Usingthis technique, mechanical behavior of osteoblast cell-substrate interfaces on tissueengineered materials (chitosan-Polygalacturonic Acid-nanohydroxyapatite (CPH)films) is investigated. Mechanical behavior of cells in the elastic regime over thetime scale of cell adhesion (1 day), proliferation (4 days), development (8 days)and maturation (22 days) of bone nodules is evaluated. Our results indicate that theelastic properties of flat cells are higher (indicating stiffer response, after 4 days,as compared to the round cells after 1 day and oriented cells after 8 days. Elas-tic properties of cells ( ∼ 5-12 MPa), soaked CPH films ( ∼ 10-20 MPa) and that ofcell-CPH composites ( ∼ 3-9 MPa) fall in the same order of magnitude. A similarrange of elastic properties of cell-CPH composites are measured over time, imply-ing that unique interactions between cells and CPH films are maintained that mayprovide a favorable mechanical environment to growing cells and bone nodules.Atomic Force Microscopy (AFM) imaging studies on individual cells reveal thatthe cells respond to local changes in substrate topography (as a result of substrateswelling) by modulating their shapes and various focal adhesions. Overall, CPHfilms provide a favorable microenvironment for cell organization and bone noduleregeneration that regulates the mechanical behavior of cell-substrate interactions.Keywords: nanoindentation,mechanicalbehavior,cell-substrateindentation,tis-sue engineering.
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bone nodules on chitosan Polygalacturonic Acid hydroxyapatite nanocomposite films mimic hierarchy of natural bone
Acta Biomaterialia, 2011Co-Authors: Rohit Khanna, Kalpana S. Katti, Dinesh R. KattiAbstract:The ultimate goal of bone tissue engineering is to develop bony tissues on tissue engineered constructs that mimic the native bone. Nanoscale characterization of in vitro generated bony tissues on engineered scaffolds is essential to understanding both the physical and mechanical characteristics of the engineered bone. Bone nodule formation, a typical early indicator of bone formation was observed on chitosan-Polygalacturonic Acid-hydroxyapatite (Chi-PgA-HAP) nanocomposite films without the use of differentiating media. Thus, the Chi-PgA-HAP substrates designed are osteoinductive and provide an appropriate microenvironment for cell organization and tissue regeneration. Imaging using atomic force microscopy revealed several levels of hierarchical structures of bone in the bone nodules, consisting of mineralized collagen fibers, fibrils and mineral deposits in extrafibrillar spaces. The nanoscale elastic properties of the collagen and mineral crystals were found to be in close agreement with the experimental and simulations results on natural bone reported in the literature. Fourier transform infrared spectroscopy experiments indicate the presence of collagen and biological apatite in bone nodules exhibiting the characteristics of newly precipitated, immature bone. Collectively, our structural, chemical, and mechanical analyses support the conclusion that synthetic bone nodules mimic the hierarchy of natural bone.
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Bone nodules on chitosan–Polygalacturonic Acid–hydroxyapatite nanocomposite films mimic hierarchy of natural bone
Acta biomaterialia, 2010Co-Authors: Rohit Khanna, Kalpana S. Katti, Dinesh R. KattiAbstract:The ultimate goal of bone tissue engineering is to develop bony tissues on tissue engineered constructs that mimic the native bone. Nanoscale characterization of in vitro generated bony tissues on engineered scaffolds is essential to understanding both the physical and mechanical characteristics of the engineered bone. Bone nodule formation, a typical early indicator of bone formation was observed on chitosan-Polygalacturonic Acid-hydroxyapatite (Chi-PgA-HAP) nanocomposite films without the use of differentiating media. Thus, the Chi-PgA-HAP substrates designed are osteoinductive and provide an appropriate microenvironment for cell organization and tissue regeneration. Imaging using atomic force microscopy revealed several levels of hierarchical structures of bone in the bone nodules, consisting of mineralized collagen fibers, fibrils and mineral deposits in extrafibrillar spaces. The nanoscale elastic properties of the collagen and mineral crystals were found to be in close agreement with the experimental and simulations results on natural bone reported in the literature. Fourier transform infrared spectroscopy experiments indicate the presence of collagen and biological apatite in bone nodules exhibiting the characteristics of newly precipitated, immature bone. Collectively, our structural, chemical, and mechanical analyses support the conclusion that synthetic bone nodules mimic the hierarchy of natural bone.
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in situ swelling behavior of chitosan Polygalacturonic Acid hydroxyapatite nanocomposites in cell culture media
International Journal of Polymer Science, 2010Co-Authors: Rohit Khanna, Kalpana S. Katti, Dinesh R. KattiAbstract:The molecular and mechanical characteristics of in situ degradation behavior of chitosan-Polygalacturonic Acid/hydroxyapatite (Chi-PgA-HAP) nanocomposite films is investigated using Fourier Transform Infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), and modulus mapping techniques for up to 48 days of soaking in cell culture media. The surface molecular structure of media-soaked samples changes over the course of 48 days of soaking, as indicated by significant changes in phosphate vibrations (1200–900 c m − 1 ) indicating apatite formation. Chitosan-Polygalacturonic Acid polyelectrolyte complexes (PECs) govern structural integrity of Chi-PgA-HAP nanocomposites and FTIR spectra indicate that PECs remain intact until 48 days of soaking. In situ AFM experiments on media-soaked samples indicate that soaking results in a change in topography and swelling proceeds differently at the initial soaking periods of about 8 days than for longer soaking. In situ modulus mapping experiments are done on soaked samples by probing ∼ 1–3 nm of surface indicating elastic moduli of ∼ 4 GPa resulting from proteins adsorbed on Chi-PgA-HAP nanocomposites. The elastic modulus decreases by ∼ 2 GPa over a long exposure to cell culture media (48 days). Thus, as water enters the Chi-PgA-HAP sample, surface molecular interactions in Chi-PgA-HAP structure occur that result in swelling, causing small changes in nanoscale mechanical properties.
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In Situ Swelling Behavior of Chitosan-Polygalacturonic Acid/Hydroxyapatite Nanocomposites in Cell Culture Media
International Journal of Polymer Science, 2010Co-Authors: Rohit Khanna, Kalpana S. Katti, Dinesh R. KattiAbstract:The molecular and mechanical characteristics of in situ degradation behavior of chitosan-Polygalacturonic Acid/hydroxyapatite (Chi-PgA-HAP) nanocomposite films is investigated using Fourier Transform Infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), and modulus mapping techniques for up to 48 days of soaking in cell culture media. The surface molecular structure of media-soaked samples changes over the course of 48 days of soaking, as indicated by significant changes in phosphate vibrations (1200–900 c m − 1 ) indicating apatite formation. Chitosan-Polygalacturonic Acid polyelectrolyte complexes (PECs) govern structural integrity of Chi-PgA-HAP nanocomposites and FTIR spectra indicate that PECs remain intact until 48 days of soaking. In situ AFM experiments on media-soaked samples indicate that soaking results in a change in topography and swelling proceeds differently at the initial soaking periods of about 8 days than for longer soaking. In situ modulus mapping experiments are done on soaked samples by probing ∼ 1–3 nm of surface indicating elastic moduli of ∼ 4 GPa resulting from proteins adsorbed on Chi-PgA-HAP nanocomposites. The elastic modulus decreases by ∼ 2 GPa over a long exposure to cell culture media (48 days). Thus, as water enters the Chi-PgA-HAP sample, surface molecular interactions in Chi-PgA-HAP structure occur that result in swelling, causing small changes in nanoscale mechanical properties.
V. D. Mavrov - One of the best experts on this subject based on the ideXlab platform.
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complex equilibria in the system m2 Polygalacturonic Acid pectin h2o m co ni cu zn cd and pb
Journal of Coordination Chemistry, 1994Co-Authors: K. A. Davarski, S. N. Manolov, I. N. Petrova, V. D. MavrovAbstract:Abstract Ionisation constants for Polygalacturonic Acid (pectin) were determined by pH-metric titration in aqueous solution at different temperatures (283, 293, 303 and 313 K) and ionic strengths (0.1, 0.5, 1.0, 1.5 and 2.0), maintained with NaNO3. Complexing of pectin with Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+ under the same conditions and M:L ratios of 1:2 or 1:4 was studied. It was found that ML complexes prevail. Stability constants were evaluated. Complexformation is a result of favourable entropy changes, whereas there is no significant change of enthalpy. The possibility of metal extraction by complex formation and ultrafiltration was examined. Selectivities in ultrafiltration and productivities of membranes for Cu2+ complexes of pectin were determined.
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COMPLEX EQUILIBRIA IN THE SYSTEM M2+-Polygalacturonic Acid (PECTIN) - H2O (M = Co, Ni, Cu, Zn, Cd AND Pb)
Journal of Coordination Chemistry, 1994Co-Authors: K. A. Davarski, S. N. Manolov, I. N. Petrova, V. D. MavrovAbstract:Abstract Ionisation constants for Polygalacturonic Acid (pectin) were determined by pH-metric titration in aqueous solution at different temperatures (283, 293, 303 and 313 K) and ionic strengths (0.1, 0.5, 1.0, 1.5 and 2.0), maintained with NaNO3. Complexing of pectin with Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+ under the same conditions and M:L ratios of 1:2 or 1:4 was studied. It was found that ML complexes prevail. Stability constants were evaluated. Complexformation is a result of favourable entropy changes, whereas there is no significant change of enthalpy. The possibility of metal extraction by complex formation and ultrafiltration was examined. Selectivities in ultrafiltration and productivities of membranes for Cu2+ complexes of pectin were determined.
Jia-wei Chen - One of the best experts on this subject based on the ideXlab platform.
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preparation and characterization of Polygalacturonic Acid rosmarinic Acid membrane crosslinked by short chain hyaluronate for preventing postoperative abdominal adhesion
Carbohydrate Polymers, 2012Co-Authors: Mingwei Lee, Hsiuhui Peng, Tzi-peng Yang, Jia-wei ChenAbstract:Abstract The most used materials for anti tissue adhesion after surgery are polymeric membranes. In this study, a short chain hyaluronate (sHA)-crosslinked Polygalacturonic Acid (PGA) membrane containing rosmarinic Acid (PGA/RA membrane) was prepared and characterized. The in vitro dynamic release behavior of RA from the PGA membranes was analyzed. The profiles showed 70% of the total RA released from the membrane after 5 days. The best-fitting mathematical model for RA release from the PGA membrane was the Korsmeyer–Peppas model ( r 2 = 0.996). In vivo evaluation of anti-postoperative tissue adhesion showed that use of a PGA/RA membrane reduced adhesion incidence by 90%. Anti-inflammatory analysis results showed that on the third day following surgery, the number of neutrophils and macrophages in the PGA-treated group (without RA) was 2.1 and 2.4 times that of the PGA/RA-treated group, respectively. Thus, the PGA/RA membrane developed in this study has anti-postoperative tissue adhesion and anti-inflammatory capabilities.
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Preparation and characterization of Polygalacturonic Acid/rosmarinic Acid membrane crosslinked by short chain hyaluronate for preventing postoperative abdominal adhesion
Carbohydrate Polymers, 2012Co-Authors: Mingwei Lee, Hsiuhui Peng, Tzi-peng Yang, Jia-wei ChenAbstract:Abstract The most used materials for anti tissue adhesion after surgery are polymeric membranes. In this study, a short chain hyaluronate (sHA)-crosslinked Polygalacturonic Acid (PGA) membrane containing rosmarinic Acid (PGA/RA membrane) was prepared and characterized. The in vitro dynamic release behavior of RA from the PGA membranes was analyzed. The profiles showed 70% of the total RA released from the membrane after 5 days. The best-fitting mathematical model for RA release from the PGA membrane was the Korsmeyer–Peppas model ( r 2 = 0.996). In vivo evaluation of anti-postoperative tissue adhesion showed that use of a PGA/RA membrane reduced adhesion incidence by 90%. Anti-inflammatory analysis results showed that on the third day following surgery, the number of neutrophils and macrophages in the PGA-treated group (without RA) was 2.1 and 2.4 times that of the PGA/RA-treated group, respectively. Thus, the PGA/RA membrane developed in this study has anti-postoperative tissue adhesion and anti-inflammatory capabilities.