College of Pharmacy, Jinan University, Guangzhou 511443, Guangdong, P. R. China.
School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, Guangdong, P. R. China.
J Mater Chem B. 2021 Oct 6;9(38):8121-8137. doi: 10.1039/d1tb01201k.
The delayed healing of infected post-operative wounds has turned into a worldwide medical problem. In the clinical treatment, effective bacterial clearance and promoted wound healing were considered as two crucial aspects. However, the effect of current dressings with antibacterial activity was limited due to the declined efficacy against antibiotic-resistant bacteria, and poor mechanical property during skin extension and compression movement. In this project, a lyotropic liquid crystal (LLC)-based bacteria-resistant and self-healing spray dressing loaded with ε-polylysine (PLL) was designed. Owing to the unique antibacterial mechanism, PLL was expected to kill antibiotic-resistant bacteria efficiently, even the "superbug" methicillin-resistant (). The cubic cells of LLC were applied to encapsulate PLL to improve its stability and induce a sustained release, further realizing a long-term antibacterial effect. Meanwhile, the LLC precursor (LLCP) could extend to the irregular edges of the wound, and spontaneously transited to a cubic phase gel once exposed to physiological fluid. This 3D structure was also endowed with mechanically responsive viscoelasticity that formed a robust and flexible defense for wounds. An excellent antibacterial activity with more than 99% killed in 3 h was demonstrated by a killing kinetics study. The long-term effect was also proved by measuring the bacteriostatic circle test within 48 h. In addition, the unique sol-gel phase transition behavior and superior self-healing capacity of PLL-LLCP was verified with the rheological study and self-recoverable conformal deformation test . In the infected post-operative wound model, satisfactory bacterial clearance and prominent wound healing promotion were realized by PLL-LLCP, with the survival of the bacteria at lower than 0.1% and the wound closure at higher than 90%. Thus, PLL-LLCP was believed to be an excellent candidate for the therapy of infected post-operative wounds.
感染性术后伤口愈合延迟已成为全球性的医学难题。在临床治疗中，有效清除细菌和促进伤口愈合被认为是两个关键方面。然而，目前具有抗菌活性的敷料由于对抗生素耐药菌的疗效下降以及在皮肤拉伸和压缩运动中的机械性能差，其效果有限。在本项目中，设计了一种基于溶致液晶（LLC）的具有抗菌和自修复功能的喷雾敷料，其中负载了 ε-聚赖氨酸（PLL）。由于独特的抗菌机制，PLL 有望有效杀死抗生素耐药菌，甚至是耐甲氧西林金黄色葡萄球菌（MRSA）。立方 LLC 细胞被应用于包封 PLL 以提高其稳定性并诱导其持续释放，从而实现长期的抗菌效果。同时，LLC 前体（LLCP）可以延伸到伤口的不规则边缘，并在暴露于生理流体时自发地转变为立方相凝胶。这种 3D 结构还具有机械响应的粘弹性，为伤口提供了强大而灵活的保护。通过杀菌动力学研究证明了具有超过 99%杀菌率的优异抗菌活性，在 3 小时内即可实现。通过在 48 小时内测量抑菌圈试验也证明了长期效果。此外，通过流变学研究和自修复可变形测试，验证了 PLL-LLCP 的独特溶胶-凝胶相转变行为和卓越的自修复能力。在感染性术后伤口模型中，PLL-LLCP 实现了令人满意的细菌清除和明显的伤口愈合促进作用，细菌存活率低于 0.1%，伤口闭合率高于 90%。因此，PLL-LLCP 被认为是感染性术后伤口治疗的优秀候选者。
