Papers by Keyword: Hyaluronic Acid (HA)

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Authors: Eun Ju Oh, Ji Seok Kim, Sei Kwang Hahn
Abstract: A novel protocol to control the molecular degradation of hyaluronic acid (HA) was successfully developed. HA has a different conformational structure in water and in organic solvent, and the carboxyl group of HA is known to be the recognition site of CD44 and hyaluronidase. Based on these facts, HA was chemically modified in the mixed solvent of water and ethanol by grafting adipic acid dihydrazide (ADH) to the carboxyl group of HA, which resulted in high degree of ADH modification up to 85 mol% with controlled degradation of HA by hyaluronidase. The degradation controlled HA-ADH will be assessed for various tissue engineering applications.
Authors: Mi Sook Kim, Yoon Jeong Choi, Gun Woo Kim, In Sup Noh, Yong Doo Park, Kyu Back Lee, In Sook Kim, Soon Jung Hwang, Gil Won Yoon
Abstract: Characterization of an hyaluronic acid (HA)-poly(ethylene oxide) (PEO) hydrogel was performed by changing the number of side arms in a PEO molecule. Verification of grafting chemistry and mechanical strength, as well as swelling behaviors and surface morphologies of the HA-PEO hydrogels were analyzed by employing different x-linking molecular weights (MW) of PEO ranging from 1.7 to 5.0 kDa at a fixed low MW HA in the hydrogel network. Methacrylation to the HA successfully obtained via Michael type reaction between the methacrylate arm groups in HA and the thiol end groups in PEO was observed by XPS. Hydrogel formation was markedly dependent upon the numbers of thiol groups in the PEO molecule. Furthermore the lower MW PEO-based HA hydrogel demonstrated stronger mechanical properties but lower water absorption and the smaller pore sizes on its surface and cross section.
Authors: Kentaro Suzuki, Takahisa Anada, Yoshitomo Honda, Koshi N. Kishimoto, Naohisa Miyatake, Masami Hosaka, Hideki Imaizumi, Eiji Itoi, Osamu Suzuki
Abstract: We have previously shown that synthetic octacalcium phosphate (OCP) displays highly osteoconductive and biodegradable characteristics. However, OCP cannot be sintered without thermal decomposition due to the existence of water molecules in the structure. The acquisition of the moldability and the improvement of the handling property in this material are subjects for the clinical use. In the present study, we prepared OCP complex with hyaluronic acid (Hya) that could be used in the injectable form and further examined the bone tissue reaction to cortical bone by placing the complex directly on an 8-weeks-old ICR mouse calvaria in comparison with the placement of OCP granules only. The granule form of OCP (between 300 to 500 μm in diameter) was mixed with sodium hyaluronic acid with molecular weights 90 x 104. The complex revealed an injectable characteristic if it was utilized in a syringe. After polytetrafluoroethylen ring was mounted on mouse calvaria, the inner space of the ring was filled with the complex and left the complex as it is for 6 weeks. Histological examination using the decalcified specimens indicated that the OCP/Hya complex exhibited greater bone formation than OCP granules only group within the ring at 6 weeks. The results suggested that the OCP/Hya complex could be used as an injectable and osteoconductive bone substitute material in many clinical situations.
Authors: Nicolas Duceppe, Maryam Tabrizian
Abstract: In this work, we report on the development of a multifunctional and photo-inducible nanoplex made of chitosan (Ch) and hyaluronic acid (HA) for delivery of nucleic acid. Self-assembled Ch/HA nanoparticles were attached to ortho-nitrobenzyl (o-NB) photo-labile molecules (PL)-gold nanoparticles via thiol groups and to QDs-conjugate ssDNA through amide bond linkage to form nanoplexes (Ch:HA:AuPL:QD-DNA). The composition of DNA nanocarriers was validated by nuclear magnetic resonance, transmission electronic microscopy, energy dispersive x-ray spectroscopy, gel electrophoresis and spectrophotometry. The change in zeta potential (34 ± 11 to -26 ± 11 mV) and the loss of the o-NB characteristic peaks in nuclear magnetic resonance spectra, after the exposure of the PL molecule to ultraviolet light, both confirmed the photo-labile properties of the system. The potential of the nanoplexes to induce high cell transfection was assessed by flow cytometry and fluorescent microscopy imaging. Over 30% transfection of HEK-293 was obtained with the nanoplexes after a one-minute exposure of cells to UV light. This corresponds to a 15% increase in the transfection efficiency compared to unexposed Ch:HA:AuPL:QD-DNA nanocarriers. This high transfection efficiency was associated with the unique design of the carrier system and its photo-responsiveness feature for facilitating the DNA release.
Authors: Jing Di Chen, Ying Jun Wang, Xiao Feng Chen
Abstract: Owing to the unique characters of the hybrid scaffold components, a novel biodegradable porous composite scaffold was prepared. The nano hydroxyapatite (HAP) (73~136 nm) was crystallized in situ on the organic polyelectrolyte complex matrix through a biomimetic method. The polyelectrolyte complex composed of chitosan and hyaluronic acid had strong impacts on the formation of the nano HAP and directed in situ crystallization of the nano HAP as template. The in situ nano HAP reduced the interfacial energy and presented nano intensifier to the nano hybrid scaffold. Meanwhile, the scaffold kept high porosity.
Authors: Mi Sook Kim, Yoon Jeong Choi, Gun Woo Kim, In Sup Noh, Yong Doo Park, Kyu Back Lee, In Sook Kim, Soon Jung Hwang
Abstract: In vitro cell behaviors of calvarial osteoblasts (MC3T3) were evaluated by seeding them on both the surface and inside of in situ hyaluronic acid-poly(ethylene oxide) (HA-PEO) hydrogel, either after or before incorporation of mixture micro-particles of hydroxyapatite-β-tricalcium phosphate on/inside the hydrogel, respectively. Cellular behaviors such as adhesion and proliferation on the surface and inside the gel were evaluated with light microscopy and a microplate reader by focusing on the interactions of cell-HA-PEO as well as cell-hydroxyapatitetricalcium phosphate micro-particle surface in the gel. Cell adhesion and spreading seemed to be enhanced by supplying the micro-particles to the inside the HA-PEO hydrogel, compared to the results of the HA-PEO hydrogel itself.
Authors: Rong Ma, Igor Zhitomirsky
Abstract: Electrophoretic deposition method has been developed for the fabrication of organic-inorganic composite films, containing bioglass and hydroxyapatite in a hyaluronic acid matrix. The film composition and deposition yield were varied by variation of the electrochemical bath composition and deposition time. The films were studied by scanning electron microscopy, thermogravimetric analysis and X-ray diffraction methods. The deposition method offers the advantages of room temperature processing and allows the fabrication of composite films for biomedical applications.
Authors: Yu Ping Li, Bing Gu, Xiao Fang Pi, Yan Chun Gong, Xiang Yuan Xiong, Guang Jie Wu, Zi Ling Li
Abstract: Hyaluronic acid (HA) is an extremely ubiquitous polysaccharide of extracellular matrix in body and plays various biological roles. In this study, cell viability, insulin secretion and cytosolic free Ca2+ concentration were investigated in HIT-T15 cells after HA-treatment. The cell viability was determined by the MTT assay while the insulin secretion was detected by ELISA technique. The Flou-3/AM was applied to probe intracellular free calcium concentration. HA (0.25, 0.5, 1.0 mg/dish) increase insulin secretion in the 3 or 25 mM glucose-stimulation for 4 h. Cytosolic Ca2+ fluorescent intensity in HA-treatment groups (0.25, 0.5, 1.0 mg/dish) is significantly higher than that in control group. This study implied that the increasing of insulin secretion of HIT-T15 cells by HA-coating result from the enhancement of cytosolic Ca2+. And these data also provide some information on design biocompatibility when HA used as a biomaterial for bioartificial pancreas.
Authors: Mi Sook Kim, Yoon Jeong Choi, Gun Woo Kim, In Sup Noh, Yong Doo Park, Kyu Back Lee, In Sook Kim, Soon Jung Hwang
Abstract: Though hyaluronic acid (HA)-based hydrogel has drawn great attention in biomedical society, it’s long molecular weights sometimes have been problematic due to its difficulty in handling. After reduction of its high molecular weight into smaller sizes with various concentrations of hydrogen chloride solutions, its chemical and biological properties have been examined by changes in viscosity, FTIR spectroscopy and gel permeation chromatography as well as cellular interactions. While FTIR analysis indicated maintenance of its original chemical structures, its viscosity has been remarkably reduced and its extent was dependent upon the employment of acid concentrations. After controlling its molecular weight to approximately 100 kDa and coupling of aminopropymethacrylate to the treated HA, we evaluated in vitro cellular interactions and cell proliferations of the HA-poly(ethylene oxide) (PEO) hydrogel.
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