机构:[1]Academy for Advanced Interdisciplinary Studies,Beijing 100871, China[2]Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, China[3]China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing 100053, China中美神经科学研究所首都医科大学宣武医院
With the progressively increasing demand for orthopedic Ti implants, the balance between two primary complications restricting implant applications is needed to be. solved: the lack of bone tissue integration and biomedical device associated infections (BAI), where emergence of multiresistance bacteria make it worse. Notably, a combination of silver nanoparticles (AgNPs) and a kind of antibiotic can synergistically inhibit bacterial growth, where a low concentration of AgNPs has been confirmed to promote the proliferation and osteogenesis of osteoblasts. In this work, we built AgNPs/gentamicin (Gen) embedded silk fibroin (SF)-based biomimetic coatings on orthopedic titanium by a facile dipping-drying circular process and with the assistance of polydopamine (PD). Ag+ was reduced to AgNPs by SF under ultraviolet (UV) irradiation, and then they were detected by transmission electron microscope (TEM) images and UV-visible (UV-vis) analyses. Intriguingly, the addition of Gen highly improved the reduction efficiency of Ag+. The antibacterial efficiency of SF -based coatings was examined by challenging them with pathogenic Staphylococcus aureus (S. aureus) bacteria which produced biofilms, and consequently, we found that low concentration loading, durable release of Ag+ (28 days), and 10-fold improvement of antibacterial efficiency were achieved for our novel AgNPs- and Gen-embeded silk fibroin coatings. In bacteria and a cells cocultured system, AgNPs/Gen-embedded coatings strongly inhibited adhesion and proliferation of S. aureus, simultaneously improving cell adhesion and growth. To investigate cytocompatibility and osteogenic potential, different coatings were cultured with MC3T3 cells; AgNPs/Gen-embedded coatings showed generally acceptable biocompatibility (cell adhesion, proliferation, and viability) and accelerated osteoblast maturation (alkaline phosphatase production, matrix secretion, and calcification). Expectantly, this novel biofunctional coating will have promising applications in orthopedic and dental titanium implants thanks to its excellently antibacterial, biocompatible, and osteogenic activities.
基金:
the National Natural Science Foundation of China (Nos. 31670974 and 31370954),
the Project of Scientific and Technical Plan of Beijing (No. Z141100002814008),
Beijing Natural Science Foundation (2164073).