Sahu Khageswar, Sharma Mrinalini, Sharma Priyanka, Verma Yogesh, Rao Kompalli Divakar, Bansal Harsha, Dube Alok, Gupta Pradeep Kumar
1 Laser Biomedical Applications and Instrumentation Division , Raja Ramanna Centre for Advanced Technology, Madhya Pradesh, India .
Photomed Laser Surg. 2014 Jan;32(1):23-9. doi: 10.1089/pho.2013.3577. Epub 2013 Dec 20.
The purpose of this work was to study the effect of poly-L-lysine-conjugated chlorin P6 (pl-cp6)-mediated antimicrobial photodynamic treatment (APDT) on collagen remodeling of murine excisional wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PAO).
Bacterial infection of wounds leads to compromised collagen remodelling. APDT-induced inactivation of bacteria and bacterial proteases are expected to restore collagen remodeling in wounds. However, published reports on the effect of PDT on wound healing are somewhat contradictory. One of the reasons for these observations could be the random sampling of wound repair outcomes by invasive technques such as histology.
Post-wounding time-dependent changes in collagen restoration were monitored noninvasively using polarization sensitive optical coherence tomography (PSOCT) and compared with histology and hydroxyproline level. Immunoblotting was performed to study matrix metalloproteinase (MMP) level.
As indicated by retardance measurements from PSOCT images and immunoblotting, bacteria-infected wounds showed slower collagen restoration and higher MMP-8, 9 expression, than did uninfected wounds. In contrast, in infected wounds treated with pl-cp6 and light, retardance was higher (approximately twofold) compared with wounds treated with pl-cp6 alone. These results were consistent with lower MMP-8, 9 level on day 5, more ordered collagen matrix, and higher hydroxyproline content (approximately threefold) on day 18, observed in photodynamically treated wounds, compared with that of untreated infected wounds.
APDT expedites healing in bacteria-infected wounds in mice by attenuating collagen degradation and by enhancing epithelialization, hydroxyproline content, and collagen remodelling.
本研究旨在探讨聚-L-赖氨酸共轭二氢卟吩P6（pl-cp6）介导的抗菌光动力疗法（APDT）对耐甲氧西林金黄色葡萄球菌（MRSA）和铜绿假单胞菌（PAO）感染的小鼠切除伤口胶原重塑的影响。
伤口细菌感染会导致胶原重塑受损。APDT诱导的细菌及细菌蛋白酶失活有望恢复伤口中的胶原重塑。然而，关于光动力疗法对伤口愈合影响的已发表报告存在一定矛盾。这些观察结果的原因之一可能是采用组织学等侵入性技术对伤口修复结果进行随机取样。
使用偏振敏感光学相干断层扫描（PSOCT）对伤口愈合过程中胶原恢复的时间依赖性变化进行无创监测，并与组织学和羟脯氨酸水平进行比较。通过免疫印迹法研究基质金属蛋白酶（MMP）水平。
PSOCT图像的延迟测量和免疫印迹结果表明，与未感染伤口相比，细菌感染伤口的胶原恢复较慢，MMP-8、9表达较高。相比之下，在接受pl-cp6和光照治疗的感染伤口中，延迟比单独使用pl-cp6治疗的伤口更高（约两倍）。这些结果与光动力治疗伤口在第5天MMP-8、9水平较低、第18天胶原基质更有序以及羟脯氨酸含量较高（约三倍）一致，而未治疗的感染伤口则不然。
APDT通过减轻胶原降解、增强上皮化、增加羟脯氨酸含量和促进胶原重塑来加速小鼠细菌感染伤口的愈合。
