Ahmed W, Zhai Z, Gao C
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Mater Today Bio. 2019 Jun 25;2:100017. doi: 10.1016/j.mtbio.2019.100017. eCollection 2019 Mar.
Bacterial infections on the implant surface may eventually lead to biofilm formation and thus threaten the use of implants in body. Despite efficient host immune system, the implant surface can be rapidly occupied by bacteria, resulting in infection persistence, implant failure, and even death of the patients. It is difficult to cope with these problems because bacteria exhibit complex adhesion mechanisms to the implants that vary according to bacterial strains. Different biomaterial coatings have been produced to release antibiotics to kill bacteria. However, antibiotic resistance occurs very frequently. Stimuli-responsive biomaterials have gained much attention in recent years but are not effective enough in killing the pathogens because of the complex mechanisms in bacteria. This review is focused on the development of highly efficient and specifically targeted biomaterials that release the antimicrobial agents or respond to bacteria on demands in body. The mechanisms of bacterial adhesion, biofilm formation, and antibiotic resistance are discussed, and the released substances accounting for implant infection are described. Strategies that have been used in past for the eradication of bacterial infections are also discussed. Different types of stimuli can be triggered only upon the existence of bacteria, leading to the release of antibacterial molecules that in turn kill the bacteria. In particular, the toxin-triggered, pH-responsive, and dual stimulus-responsive adaptive antibacterial biomaterials are introduced. Finally, the state of the art in fabrication of dual responsive antibacterial biomaterials and tissue integration in medical implants is discussed.
植入物表面的细菌感染最终可能导致生物膜形成，从而威胁植入物在体内的使用。尽管宿主免疫系统有效，但植入物表面仍可能迅速被细菌占据，导致感染持续存在、植入物失效，甚至患者死亡。由于细菌对植入物表现出复杂的粘附机制，且因细菌菌株而异，因此难以应对这些问题。人们制备了不同的生物材料涂层来释放抗生素以杀死细菌。然而，抗生素耐药性非常频繁地出现。近年来，刺激响应性生物材料备受关注，但由于细菌中的复杂机制，它们在杀死病原体方面效果不够理想。本综述重点关注高效且具有特异性靶向性的生物材料的开发，这些材料可释放抗菌剂或根据体内需求对细菌做出反应。讨论了细菌粘附、生物膜形成和抗生素耐药性的机制，并描述了导致植入物感染的释放物质。还讨论了过去用于根除细菌感染的策略。仅在细菌存在时才能触发不同类型的刺激，从而导致抗菌分子释放，进而杀死细菌。特别介绍了毒素触发、pH响应和双刺激响应的适应性抗菌生物材料。最后，讨论了双响应抗菌生物材料制造和医疗植入物中组织整合的最新进展。
