ABSTRACT
Blue light is commonly used to kill Propionibacterium acnes in clinic. Furthermore, blue light exhibits a good bactericidal effect against Helicobacter pylori, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and many oral bacteria in laboratory studies. The bactericidal mechanism of blue light as commonly accepted consists photo-excitation of intracellular porphyrins resulting in production of cytotoxic reactive oxygen species which can inactivate bacteria. Blue light can kill bacteria without additional exogenous photosensitizers. In addition, it produces little harm to mammalian cells. Therefore, as the increasing emergence of antibiotic resistant microorganisms, blue light might be a good antibacterial tool.
Subject(s)
Humans , Anti-Bacterial Agents , Bacteria , Bacterial Infections , Therapeutics , Light , PhototherapyABSTRACT
Objective To evaluate the effects of external substance P (SP) on scalding wound healing and neovascularization.Methods Eighty-four Wistar rats were induced into diabetic models by intraperitoneal injection of streptozotocin (STZ), and deep partial thickness scalding wound on the back with diameter of 2 cm was prepared. Rats were randomly divided into experiment group (n=42, local injection of SP) and control group (n=42, local injection of PBS). The process of wound healing was observed, and the percentages of wound closure were calculated on D0, D1, D3, D7, D10, D14, D21 post scald. The expression of CD31, surface marker of neovascular endothelial cells, was detected within the wound sites by immunohistochemical staining, and the microvessel density was calculated. Results The percentage of wound closure in experiment group was significantly higher than that in control group on D7 post scald [(42.69±3.26) % vs (30.24±1.17)%, P<0.01]. Immunohistochemical detection revealed that the expression of CD31 and the microvessel density in experiment group were significantly higher than those in control group from D7 post scald (P<0.01). ConclusionExternal SP may promote scalding wound healing in diabetic rats, the mechanism of which may be associated with upregulation of expression of CD31 and acceleration of neovascularization.