Huajia Diao

Bletilla striata Polysaccharide Stimulates Inducible Nitric Oxide Synthase and Proinflammatory Cytokine Expression in Macrophages

Bletilla striata, a traditional Chinese medicine, has been used for the treatment of alimentary canal mucosal damage, ulcers, bleeding, bruises and burns. B. striata polysaccharide (BSP) isolated from B. striata was found to enhance vascular endothelial cell (EC) proliferation and vascular endothelial growth factor (VEGF) expression. However, the wound healing mechanism of BSP is not well understood. In this study, the results show that treatment with BSP induces coordinate changes in inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1beta) mRNA levels and enhances the expression of these cytokines, but has no effect on interferon gamma (IFN-gamma) level. In this study, we partially elucidate the wound healing mechanism of BSP.

A physiologically active polysaccharide hydrogel promotes wound healing

When the skin is injured, the subcutaneous tissues and organs are threatened by pathogens and excessive water loss. Wound dressings are, therefore, needed to protect the wound site from infection and improve the wound closure. Natural polysaccharides have been applied for various biomaterials including wound dressings, which show their advantages in biocompatibility, low toxicity, and pharmaceutical biomedical activity. In this study, a natural polysaccharide Bletilla striata polysaccharide (BSP) hydrogel is prepared by an oxidation and crosslinking methods. This BSP hydrogel represents preferable swelling ability and appropriate water vapor transmission rate. Using a full-thickness trauma mouse model, the hydrogel is applied on the in vivo cutaneous wound healing. Compared with the control groups, the BSP hydrogel achieves the much better healing results. The quantification of the infiltrating inflammatory cells and the level of tumor necrosis factor alpha (TNF-alpha) in the BSP group are attenuated, whereas the secretion of the epidermal growth factor (EGF) is highly elevated. On the 11th day after surgery, the wound area in the BSP hydrogel group is only 1/5-1/3 of those in the control groups. This new BSP hydrogel is proved to control the inflammatory responses and accelerate the wound closure and has potential application in wound healing. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

Antisense oligonucleotide targeting TNF-α can suppress co-cr-mo particle-induced osteolysis†

The most common cause of implant failure in joint replacement is aseptic loosening due to particle‐induced osteolysis. TNF‐α has been shown to be one of the key factors in the process of osteoclastogenesis. Anti‐TNF agents are useful in the treatment of joint inflammation related to osteolysis. This study investigated the effect of a single subcutaneous dose of an antisense oligonucleotide (ASO) on particle‐induced osteolysis. We utilized the murine calvaria osteolysis model in C57BL/J6 mice. Bone resorption was measured by the toluidine blue staining. Osteoclasts were detected by tartrate resistant acid phosphatase (TRAP) staining assay and were quantified by a TRAP quantification kit. Results show that bone resorption is 0.347 ± 0.09 mm2 in mice with particle implantation, and decreased to 0.123 ± 0.05 mm2 and 0.052 ± 0.02 mm2 after ASO treatment with low and high doses, respectively. The number of osteoclasts in animal calvaria treated with ASO is reduced compared with that of untreated animals, and the quantification results indicate that about 90% of osteoclastogenesis is suppressed by the ASO. In addition, the osteoclastogenesis can be reestablished by the addition of TNF‐α. In conclusion, we demonstrate that the antisense oligonucleotide targeting to TNF‐α can suppress osteolysis induced by metal particles in a murine calvaria model. This new finding may be of value in the search for novel therapeutic methods for implant loosening.