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Abstract: The chitin/gelatin composite membranes were prepared by mixing of chitin hydrogel with gelatin. The prepared composite membranes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical, swelling, enzymatic degradation and thermal studies. The XRD pattern of the chitin/gelatin composite membranes showed almost the same pattern as α-chitin. The bioactivity studies of these chitin/gelatin membranes were carried out with the simulated body fluid solution (SBF) for 7, 14 and 21 days followed by the characterization with the scanning electron microscopy (SEM) and Energy Dispersive Spectrum (EDS) studies. The SEM and EDS studies confirmed the formation of calcium phosphate layer on the surface of chitin/gelatin membranes. Biocompatibility of the chitin/gelatin membrane was assessed using human MG-63 osteoblast-like cells. After 48h of incubation, it was found that the cells had attached and completely covered the membrane surface. Thus, the prepared chitin/gelatin membranes are bioactive and are suitable for cell adhesion suggesting that these membranes can be used for tissue-engineering applications. [Copyright &y& Elsevier]

Abstract: Chitin and chitosan are novel biomaterials. The novel chitosan/gelatin membranes were prepared using the suspension of chitosan hydrogel mixed with gelatin. The prepared chitosan/gelatin membranes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical, swelling, and thermal studies. The morphology of these chitosan/gelatin membranes was found to be very smooth and homogeneous. The XRD studies showed that the chitosan/gelatin membranes have good compatibility and interaction between the chitosan and gelatin. The stress and elongation of chitosan/gelatin membranes on wet condition showed excellent when the mixture ratio of gelatin was 0.50. The prepared chitosan/gelatin membranes showed good swelling, mechanical and thermal properties. Cell adhesion studies were also carried out using human MG-63 osteoblast-like cells. The cells incubated with chitosan/gelatin membranes for 24h were capable of forming cell adhesion. Thus the prepared chitosan/gelatin membranes are bioactive and are suitable for cell adhesion suggesting that these membranes can be used for tissue-engineering applications. Therefore, these novel chitosan/gelatin membranes are useful for biomedical applications. [Copyright &y& Elsevier]

Abstract: Chitin is a natural biopolymer have been used for several biomedical applications due to its biodegradability and biocompatibility. By using the calcium solvent system, chitin regenerated hydrogel (RG) was prepared by using α-chitin. And also, the swelling hydrogel (SG) was prepared by using β-chitin with water. Then, both RG and SG were mixed with gelatin and N-acetyl-d-(+)-glucosamine (GlcNAc) at 120°C for 2h. The chitin/gelatin membranes with GlcNAc were also prepared by using RG and SG with GlcNAc. The prepared chitin/gelatin membranes with or without GlcNAc were characterized by mechanical, swelling, enzymatic degradation, thermal and growth of NIH/3T3 fibroblast cell studies. The stress and elongation of chitin/gelatin membrane with GlcNAc prepared from RG was showed higher than the chitin/gelatin membranes without GlcNAc. But, the chitin/gelatin membranes prepared from SG with GlcNAc was showed higher stress and elongation than the chitin/gelatin membranes without GlcNAc. It is due to the crosslinking effect of GlcNAc. The chitin/gelatin membranes prepared from SG showed higher swelling than the chitin/gelatin membranes prepared from RG. In contrast, the chitin/gelatin membranes prepared from RG showed higher degradation than the chitin/gelatin membranes prepared from SG. And also, these chitin/gelatin membranes are showing good growth of NIH/3T3 fibroblast cell. So these novel chitin/gelatin membranes are useful for tissue engineering applications. [Copyright &y& Elsevier]

Abstract: Chitin is a natural biopolymer that has been investigated for its prospected biomedical applications due to its several biological advantages. However, the chitin is very difficult to dissolve in common solvents due to its rigid crystalline structure. But it is soluble in saturated calcium solvent system under mild conditions. By using the calcium solvent system, chitin regenerated hydrogel (RG) was prepared by using α-chitin. And we also prepared swelling hydrogel (SG) by using β-chitin with water. In addition, the SG was mixed with glutaraldehyde (GA) or N-acetyl d-(+)-glucosamine (GlcNAc) at 120°C for 2h. The chitin membranes were prepared by using RG and SG with or without GA or GlcNAc. The prepared chitin membranes were characterized by mechanical, swelling, enzymatic degradation, thermal, and growth of NIH/3T3 fibroblast cell studies. The stress and elongation of chitin membranes prepared from SG with GA or 10% (w/w) GlcNAc were increased due to the cross-linking effect. The chitin membranes prepared from SG showed higher swelling and degradation than the membranes prepared from RG. Moreover, the chitin membranes prepared from SG with GA or GlcNAc showed lower swelling and degradation than the untreated one. The thermal studies showed that the chitin membranes prepared from RG showed higher thermal stability than the other chitin membranes prepared from SG. And also, these membranes showed good growth of NIH/3T3 fibroblast cells although a little aggregation of cells was observed. So, these chitin membranes are promising biomaterials that can be useful for tissue engineering applications. [Copyright &y& Elsevier]

Abstract: Chitosan a natural based polymer is non-toxic, biocompatible and biodegradable. Chemical modification of chitosan to generate new bifunctional materials and finally would bring new properties depending on the nature of the group introduced. In our present study, we prepared phosphorylated chitosan (P-chitosan) by using H3PO4/P2O5/Et3PO4/hexanol method. From our present method, we got high yield and high degree of substitution (DS). The prepared P-chitosan (DS-1.18) was characterized by FT IR, 13C NMR, 31P NMR, elemental, XRD, TGA, DTA and SEM studies. After the phosphorylation, the solubility of the polymer was improved. The P-chitosan showed less thermal stability and crystallinity than the chitosan. It was due to the phosphorylation. [Copyright &y& Elsevier]

Abstract: The crystalline structure of β-chitin from squid pen was investigated by X-ray diffraction (XRD). The purified β-chitin was prepared from bigfin reefsquid pen. β-Chitin was treated with saturated calcium chloride dihydrate/alchohol (CaCl2·2H2O/MeOH) solvent system at different conditions for XRD studies. The change of crystallinity of β-chitin from squid pen was studied by using the fiber photographs on imaging plates. The results showed that the diffraction peak (010) was shifted. It means that the lattice plane (010) interplanarilly spreaded to 3.4Å, when the squid pen was washed with water after treatment of Ca solvent. Furthermore, when the squid pen was dried after treatment of Ca solvent and washing with water, interplanar spacing of (010) inversely shrank to 1.1Å. These results suggested that Ca solvent especially influences the plane (010) of β-chitin structure. [Copyright &y& Elsevier]

Abstract: Based on Kawaguchi space, a seismic ray path through an anisotropic medium corresponds to an arclength under Zermelo''s condition. From a special function in Kawaguchi space, we obtain some Finslerian metrics (mth root metric or 1-form metric). Considering a variational problem of the seismic ray, Snell''s law is derived from Euler''s vector, and envelopes of seismic wavefront are classified by m-values in seismic Finsler metric. Moreover, we discuss the relation between Kawaguchi space and another ray theory. [Copyright &y& Elsevier]

Abstract: β-Chitin is a biopolymer principally found in shells of squid pen. It has the properties of biodegradability, biocompatibility, chemical inertness, wound healing, antibacterial and anti-inflammatory activities. Hydroxyapatite (HAp) is a natural inorganic component of bone and teeth and has osteoconductive property. In this work, β-chitin–HAp composite membranes were prepared by alternate soaking of β-chitin membranes in CaCl2 (pH 7.4) and Na2HPO4 solutions for 2 h in each solution. After 1, 3 and 5 cycles of immersion, β-chitin membranes were characterized using the SEM, FT-IR, EDS and XRD analyses. The results showed the presence of apatite layer on surface of β-chitin membranes, and the amounts of size and deposition of apatite layers were increased with increasing number of immersion cycles. Human mesenchymal stem cells (hMSCs) were used for evaluation of the biocompatibility of pristine as well as composite membranes for tissue engineering applications. The presence of apatite layers on the surface of β-chitin membranes increased the cell attachment and spreading suggesting that β-chitin–HAp composite membranes can be used for tissue engineering applications. [Copyright &y& Elsevier]

Abstract: Chitin is a biopolymer and it is non-toxic, biodegradable and biocompatible. Chitin has many potential industrial applications because of its abundance, biodegradability, non-toxicity, chemical inertness. β-Chitin scaffolds were prepared by using saturated calcium chloride alcoholic solution (CaCl2·6H2O/EtOH) and then followed by dialysis with lyophilization. The prepared β-chitin scaffolds were characterized by FT-IR, scanning electron microscopy (SEM) and thermogravimetric (TGA). The preliminary bioactivity studies of β-chitin scaffolds were studied by using simulated body fluid (SBF) solution for 7, 14 and 21 days. We also immersed the β-chitin scaffolds in saturated aqueous CaCl2 and Na2HPO4 solution over 12h. After 7, 14 and 21 days, the scaffolds were characterized by SEM and FT-IR studies. The SEM studies showed that there is a calcium phosphate layer in the surface as well as in the cross-section of β-chitin scaffolds. It seems that the β-chitin scaffolds are useful in the tissue-engineering field. [Copyright &y& Elsevier]

Abstract: Multiple-organ failure related to septicemia is a common cause of early mortality after liver transplantation. Endotoxemia following living donor hepatectomy may be a cause of postoperative death. Plasma fibronectin (Fn) exerts a broad range of biological effects on cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, reticuloendothelial system function, and ischemic injury. We studied the therapeutic effect of plasma Fn in mice after an intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (GalN). Female Balb/c mice received simultaneous intraperitoneal injection of LPS (50 μg/kg) and GalN (400 mg/kg). Thirty minutes prior to GalN/LPS administration, plasma Fn or bovine serum albumin was given intravenously. A single administration of plasma Fn (500 mg/kg) protected in dose-dependent fashion against lethal shock after GalN/LPS challenge. Plasma Fn significantly reduced the serum tumor necrosis factor-α, interferon-γ, and interleukin-6 levels and significantly increased the serum interleukin-10 levels after GalN/LPS administration. Furthermore, plasma Fn significantly inhibited liver necrosis at 9 hours after GalN/LPS injection. The fraction of apoptotic-positive cells in these plasma Fn-treated mice was significantly lower than in the control group. These results support the protective treatment of endotoxin-induced liver injury by plasma Fn. [Copyright &y& Elsevier]