ABSTRACT
Objective Studies have shown that low concentrations of nicotine can promote neovascularization and promote wound healing.This article aimed to investigate the influence of low concentration collagen membrane slow-release system on the hard palate trauma of rats.Methods Using poly(lactic acid-co-glycolic acid) (PLGA) copolymer as carrier materials, low concentration nicotine sustained-release particles were prepared by emulsion evaporation method (w/o/w), using collagen membrane as the brace and establish a low concentration collagen membrane system.48 Wistar rats were divided into experimental group and blank group, 3 mm diameter circular wound was made in the forepart palate.Low concentration of nicotine collagen membrane sustained-release particle system and blank collagen membrane (control) were sutured on the wound with 6-0 absorbable thread.Then, observed the wound healing of 0, 3, 7, 10 days and compared the healing differences between each groups.Results Under the electron microscope, the nicotine sustained-release particles were circular, similar size with rough surface, the average diameter were 3.0±0.2μm, the encapsulation efficiency and drug loading rate was 50.2% and 4.12% respectively.In vitro, nicotine sustained-release particles released much more nicotine on the first day, less on the second day, tends to stable and fluctuate within a certain range from the third day on, and declined sharply after about 10 days, nicotine concentration from 3rd to 10th day was fluctuate within 10-5-10-4mol/L.Postoperative wound healing, no significant difference in 3 days(P>0.05), after 7 days, the wound healing of experimental group significantly greater compared with the control (P=0.015).The wound was healed in 10 days after operative, there was no significant difference between two groups(P>0.05).The epithelial proliferation in the experimental group was significantly greater than that in the blank group, there were many fibroblasts, inflammatory cells and new capillaries, the epithelial process is short, the submucosa is loose, and a large number of collagen fibers are produced.The lamina propria is closely connected with the periosteum, and the wound is healed Conclusion Low concentration of nicotine sustained-release particles collagen membrane system may promote wound healing in the hard palate mucosa of rats.
ABSTRACT
Objective To investigate the expression level of tryptase, chymase, IL-4 and IL-10 in guinea pigs died from anaphylactic death caused by penicillin allergy within 48 hours. Methods Guinea pigs were sensitized and elicited by penicilloyl-protein, the blood and tissues were extracted within 48 hours after the death. The expression of tryptase and chymase in tracheas and lungs were detected by the ways of immunohistochemistry, IL-4 and IL-10 levels in serum, tracheas and lungs were detected by ELISA. Results Compared with the control group, the expression of tryptase and chymase has enhanced in lungs and tracheas, the level of IL-4 and IL-10 increased in serum, lungs and tracheas in experimental groups(P<0.05). Conclusion Tryptase, chymase, IL-4 and IL-10 have significant value in the identification of the deaths caused by penicillin allergy.