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After vitrectomy, the ideal vitreous substitute should be implanted to maintain the normal function of the eye. However, the existing materials (such as silicone oil, air, perfluorocarbons, etc.) still have some shortcomings and cannot fully meet the clinical needs. In this study, thiolated hyaluronic acid (SH-HA) was prepared based on hyaluronic acid. The SH-HA hydrogel was formed by a simple transformation of the sulfhydryl group to the disulfide bond, which had high transparency, controllable swelling property, suitable mechanical strength, excellent biocompatibility and similar physical and chemical properties to natural vitreous. SH-HA hydrogel was filled into the eyes of experimental rabbits to replace their own vitreous after vitrectomy. During the 90 days follow-up period, SH-HA hydrogel showed excellent intraocular compatibility, maintained normal intraocular pressure (IOP), and no cataract, endophthalmitis, retinal detachment and other complications were observed. In general, SH-HA hydrogel has great potential as a vitreous substitute.

Herein, the thermosensitive hydroxypropyl chitin (HPCT) hydrogel was prepared and the chemical structures, microstructures, rheological properties and degradation in vitro were investigated. The HPCT hydrogel possessed satisfactory biocompatibility in mouse fibroblast cells and Sprague Dawley rats. On the other hand, N-acetylglucosamine (NAG) and carboxymethyl chitosan (CMCS) provided favorable capacity for promoting cell proliferation, delaying cell apoptosis, and facilitating the insulin secretion of rat pancreatic beta cells (RIN-m5F) in three-dimensional culture. Most importantly, the effects of HPCT/NAG and HPCT/CMCS thermosensitive hydrogels as RIN-m5F cells carriers were evaluated via injection into different areas of diabetic rats. Our results demonstrated that HPCT/NAG and HPCT/CMCS hydrogels loaded RIN-m5F cells could keep cells survival, maintain insulin secretion and reduce blood glucose for one week. Overall, the functional thermosensitive hydrogels based on HPCT were effective cell carriers for RIN-m5F cells and might provide novel strategy for the treatment of diabetes via cell engineering.

Herein, the dopamine (DA) was grafted with oxidized sodium alginate (OSA) via Schiff base reduction reaction, aiming to fabricate novel DA-grafted OSA (OSA-DA) hydrogels with enhanced biocompatibility and suitable adhesion for clinical applications. The chemical structures of OSA-DA were characterized via UV-Vis, FTIR and

Bone defects, a common orthopedic problem in clinical practice, are a serious threat to human health. As alternative materials to autologous bone grafts, synthetic cell-free functionalized scaffolds have been the focus of recent research in designing scaffolds for bone tissue engineering. Butyryl chitin (BC) is a derivative of chitin (CT) with improved solubility. It has good biocompatibility, but few studies have investigated its use in bone repair. In this study, BC was successfully synthesized with a degree of substitution of 2.1. BC films were prepared using the cast film method and showed strong tensile strength (47.8 ± 4.54 N) and hydrophobicity (86.4 ± 2.46°), which was favorable for mineral deposition. An in vitro cytological assay confirmed the excellent cell attachment and cytocompatibility of the BC film; meanwhile, in vivo degradation indicated the good biocompatibility of BC. Hydroxyapatite (HA), extracted from bovine cancellous bone, had good cytocompatibility and osteogenic induction activity for the mouse osteoblast cell line MC3T3-E1. With the aim of combining the advantages of BC and HA, a BC–HA composite scaffold, with a good pore structure and mechanical strength, was prepared by physical mixing. Administered into skull defects of rats, the scaffolds showed perfect bone-binding performance and effective structural support, and significantly promoted the regeneration of new bone. These results prove that the BC–HA porous scaffold is a successful bone tissue engineering scaffold and has strong potential to be further developed as a substitute for bone transplantation.

Third-degree scald, causing serious tissue destruction with continuous pain, easily leads to microbial infections and delayed wound healing. Therefore, a multifunctional treatment is attractive for seriously damaged tissue. Herein, carboxymethyl chitosan-coordinated argentum (Ag-CMC) was synthesized via a complexation method, and then the Ag

This study was aimed at preparing O-carboxymethyl chitosan (CM-CTS) fabrics, and examining the wound healing effects on partial-thickness burn. The functional polysaccharides were produced from chitosan needle-punched nonwovens reacted with chloroacetic acid. Then the biocompatibility and biological functions were evaluated through fibroblast L-929 and SD rats. CM-CTS fabrics were obtained with elongation at break more than 42%, tensile strength reaching 0.65 N/mm

Novel polymer-drug conjugates (CNC) were prepared from carboxymethyl chitosan (CMCS) and norcantharidin (NCTD) via amidation reaction and characterized by FTIR and 1H NMR spectroscopy. The aim of this study was to elucidate the antitumor efficacy of CNC on gastric cancer and the possible underlying mechanisms. The CNC conjugates possessed significant inhibitory effects on the proliferation of SGC-7901 cells and suppressed the migration as well as tube formation of HUVECs. Besides, Hoechst 33258 staining and Annexin V-FITC/PI detection suggested that the conjugates were more effective in triggering apoptosis of SGC-7901 cells compared with free NCTD. Moreover, CNC remarkably reduced systemic toxicity and enhanced the antitumor efficacy in vivo with a tumor suppression rate of 59.57% against SGC-7901 gastric tumor in BALB/c nude mice. Further investigation about the underlying mechanisms indicated that CNC could upregulate expressions of TNF-α and Bax, and downregulate expressions of VEGF, Bcl-2, MMP-2 and MMP-9, thereby inhibiting tumor metastasis and inducing apoptosis in vivo. Overall, our results demonstrated that CNC might be a promising and feasible polymer therapeutics for gastrointestinal tumor therapy.

Vitreous, an essential dioptric medium for the human eyes, must be filled with artificial materials once damaged. Carboxymethyl chitosan (CMCTS) is one of the most important water-soluble chitosan derivatives with improved biocompatibility and biodegradability. In this study, oxidized hyaluronic acid (OHA) was prepared as crosslinking reagent. CMCTS and OHA were used to develop a biocompatible, self-repairing and in-situ injectable hydrogel for vitreous substitutes. Results showed the hydrogel with controllable swelling properties, high transparency, acceptable cytocompatibility on mouse fibroblast L929 and histocompatibility in vivo. Furthermore, hydrogel was injected in-situ into the vitreous cavity after vitrectomy on New Zealand Rabbits, no significant and persistent adverse effects were observed during the 90-day follow-up period. In addition, the hydrogel maintained intraocular pressure of the operated eyes and the inherent position of the retina. Collectively, this injectable, biodegradable, nontoxic hydrogel possessed enormous potential to become a vitreous substitute material.

Selenium (Se) is a potential chemopreventive or chemotherapeutic agent against malignant tumor. Selenium-oligosaccharides are important selenium source of dietary supplementation. Due to the insufficient natural production, it is therefore urgent to develop selenium-oligosaccharides by artificial synthesis. Chitosan, the N-deacetylated derivative of chitin, has been applied widely in biomedical field, owing to its nontoxicity, hydrophilicity, biocompatibility, and biodegradation. While chitosan is water insoluble at neutral pH, limiting its application in physiological conditions. Chitosan oligosaccharide (COS), the hydrolysate of chitosan, is readily soluble in water because of the shorter chain lengths of the oligomers and the free amino groups in the D-glucosamine units. This study was aimed at preparing COS-conjugated selenium (COS-Se) and examining the toxicity and ability on improving immune function and blocking gastric cancer growth. Our results demonstrated that COS-Se displayed directly co-mitogenic and mitogenic actions on mouse splenocytes proliferation in vitro. Besides, COS-Se treatment could effectively elevate phagocytosis and increase the secretion of anti-inflammatory cytokine in mouse peritoneal macrophages. Further in vivo experiments showed that COS-Se exhibited immuno-enhancing effects through promoting the phagocytic index, spleen index and thymus index with no obvious toxicity to Kunming mice. Moreover, COS-Se inhibited proliferation and metastasis of human gastric cancer cells, with non-toxic effects on the normal fibroblast cells in vitro. COS-Se supplementation could significantly repress the growth of gastric adenocarcinoma through reducing levels of CD34, vascular endothelial growth factor and matrix metalloproteinase-9 of nude mice. In conclusion, COS-Se was non-toxic and showed great potential as a functional food ingredient in cancer prevention.

Herein, the effects of carboxymethyl chitosan oligosaccharide (CM-COS) on regulating immunologic function and inhibiting hepatocellular tumor growth were evaluated. Results showed that CM-COS caused dramatic viability loss of hepatocellular carcinoma BEL-7402 with non-toxicity towards normal liver L-02 cells. CM-COS repressed tumor growth of hepatoma-22, and elevated the spleen index and thymus index of tumor-bearing mice. Contents of VEGF and MMP-9 were significantly down-regulated by CM-COS. Histological analyses revealed that CM-COS promoted tumor cell necrosis and produced no significant toxicity to spleen tissues. Moreover, expressions of Caspase-3 in tumor tissues and IL-2 in spleen tissues were significantly activated by CM-COS. Additionally, in vitro cell viability, phagocytic capability and NO production of mouse peritoneal macrophages exposed to CM-COS were significantly higher. CM-COS remarkably increased the in vivo phagocytosing capacity of peritoneal macrophages of Kunming mice. Taken together, our findings suggested that CM-COS might be potentially effective and non-toxic candidate as anti-hepatoma agents.

In this study, norcantharidin (NCTD), a small-molecule anticancer drug derived from Chinese traditional medicine blister beetle (Mylabris), was conjugated covalently onto carboxymethyl chitosan (CMCS). Then the hepatocellular carcinoma therapeutic properties and liver-protective effects were investigated through orthotopic transplantation tumor model. Results showed that the obtained CMCS-NCTD demonstrated remarkable anti-growth efficacy against hepatocellular 22 in mice. Significant improvement of the liver injury caused by cancer cells was observed in tumor-bearing mice administrated with CMCS-NCTD. Moreover, CMCS-NCTD remarkably increased the serum levels of TNF-α, IFN-γ, TIMP-1 and E-cadherin in mice treated for 12days. Administration of CMCS-NCTD significantly reduced the elevated serum ALT, AST, VEGF and MMP-9 levels of tumor-bearing mice. In addition, activities of SOD and GSH-Px in serum or homogenate of the CMCS-NCTD treated mice were significantly high when compared with model control group. Our data suggested that CMCS-NCTD was a promising candidate as an anti-hepatoma and liver-protection compound.

A novel biodegradable chitin hernia patch was prepared by acetylation of chitosan fabric in our study. Physicochemical properties, cell compatibility and biodegradability of the chitin patch were quantified. Histopathological study of the functional experiment showed that this newly designed hernia patch promoted collagen deposition and neovascularization by significantly promoting the secretion of FGF1 and TGF-β1 in the early postoperative (P

Aiming to enhance therapeutic efficiency and reduce toxic effect of norcantharidin (NCTD), NCTD-conjugated carboxymethyl chitosan (CMCS) conjugates (CNC) were prepared and evaluated for the treatment of hepatocellular carcinoma. In vitro cellular assays revealed that CNC conjugates possessed potent inhibitory effects on the proliferation and migration of BEL-7402 cells. Besides, CNC could change nuclear morphology of tumor cells. In comparison with free NCTD at equivalent dose, CNC exerted enhanced therapeutic efficiency and diminished systemic toxicity in H22 tumor-bearing mice with a tumor inhibition rate of 56.20%. Further investigation about pharmacokinetics and tissue distribution by high performance liquid chromatography (HPLC) analysis indicated that CNC showed a longer retention time in blood circulation and reduced distribution in heart and kidney tissues, thereby exerting different antitumor efficacy and toxicity compared with free NCTD. Our results suggested that CNC conjugates based on CMCS as polymer carriers might be used as a potential clinical alternative for NCTD in tumor therapy.

Carboxymethyl chitosan (CMCS), a water-soluble derivative of chitosan possessing numerous enhanced physicochemical and biological properties, has emerged as a promising biopolymer carrier for new drug delivery. Norcantharidin (NCTD) is an effective anti-tumor compound with severe nephrotoxicity. In this study, norcantharidin-conjugated carboxymethyl chitosan (CMCS-NCTD) was synthesized to reduce systemic toxicity and improve anti-tumor efficiency of NCTD. Our results demonstrated that CMCS-NCTD could significantly inhibit migration of tumor cells both in vitro and in vivo in a dose-dependent manner (P