Preparation of Periplaneta americana Thermosensitive Hydrogel and Investigation of Its Wound Healing Effect on Diabetic Rats / 中国实验方剂学杂志

ABSTRACT

Objective:To prepare Periplaneta americana thermosensitive hydrogel and investigate its effect on wound healing in diabetic rats. Method:Taking N-isopropylacrylamide (NIPAM) and acrylic acid (AAc) as monomers, thermosensitive poly(NIPAM-co-AAc) [P(NIPAM-co-AAc)] polymeric material was prepared by free radical polymerization, then thermoresponsive copolymer P(NIPAM-co-AAc)-g-HA was synthesized by conjugating P(NIPAM-co-AAc) to hyaluronic acid (HA). The structure and lower critical solution temperature (LCST) of the graft copolymer were characterized by proton nuclear magnetic resonance spectroscopy (1H-NMR) and ultraviolet spectrophotometry (UV). P. americana thermosensitive hydrogel was prepared by dialysis method, and it was characterized by scanning electron microscope (SEM), rotation rheometer and thermogravimetric analyzer to observe section structure, rheological properties and thermal stability. Differential scanning calorimetry, X-ray diffraction and Fourier transform infrared spectroscopy were employed to identify the inclusion of P(NIPAM-co-AAc)-g-HA temperature sensitive material for P. americana extract, and to investigate the effect of P. americana thermosensitive hydrogel on wound healing in diabetic rats, and the rate of wound healing was calculated by Image-Pro Plus 6.0 software. Hematoxylin-eosin (HE) and Masson staining were used to observe the pathological changes of the wounds of rats in each group. Result:P(NIPAM-co-AAc)-g-HA temperature sensitive material was successfully synthesized, its LCST was between 29 ℃ and 31 ℃, it had a dense and uniform porous structure and could uniformly include P. americana extract. Pharmacodynamic studies showed that P. americana thermosensitive hydrogel group had the best effect on promoting wound healing, its infiltration degree of inflammatory cells was significantly reduced, collagen and fibroblasts arranged neatly and compactly, and the density of neovascularization was significantly increased by comparing with the model group. Conclusion:P. americana thermosensitive hydrogel can effectively promote wound healing of diabetic rats and overcome the shortage of marketed P. americana liquid preparations, this paper can provide a reference for the development of P. americana extract preparations to promote wound healing in diabetic patients.