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Infection, as a common postoperative complication of orthopedic surgery, is the main reason leading to implant failure. Silver nanoparticles (AgNPs) are considered as a promising antibacterial agent and always used to modify orthopedic implants to prevent infection. To optimize the implants in a reasonable manner, it is critical for us to know the specific antibacterial mechanism, which is still unclear. In this review, we analyzed the potential antibacterial mechanisms of AgNPs, and the influences of AgNPs on osteogenic-related cells, including cellular adhesion, proliferation, and differentiation, were also discussed. In addition, methods to enhance biocompatibility of AgNPs as well as advanced implants modifications technologies were also summarized.

Functionalization of porous titanium alloy implants with bioactive coatings to improve bone regeneration performance is hotly pursued in recent decade. Here we demonstrate a facile strategy to design bioactive 3D printed porous titanium implants with strontium (Sr) ion incorporated zeolite coatings (SZCs). The SZCs can be uniformly fabricated on the 3D porous scaffolds using an in situ hydrothermal crystal growth method to improve their osteogenesis and osteointegration capacity. In vitro experiments of SZCs on a TC4 disk show that Sr ions can slowly release in the simulated body fluid by means of ion-exchange, thus can drastically improve apatite forming ability, biocompatibility, corrosion resistance, and alkaline phosphatase (ALP) activity. In vivo evaluation on a rabbit model with 3D printed titanium implants shows that the SZCs could significantly induce new bone formation both in and around the porous implants within four weeks. This work may open up a new method for the development of bioactive customized porous implants by functionalization with zeolite coatings for orthopedic applications.

A good orthopedic load-bearing implant should have both excellent mechanical properties and biological activity. In order to improve the biological activity of Ti6Al4V-based implants, tantalum nitride (TaN) films were deposited on the surface of Ti6Al4V alloy and Si(100) substrates by magnetron sputtering. Characterized by XRD and XPS, it was proved that the uniform cubic NaCl-structure TaN films were successfully prepared on the Ti6Al4V alloy substrate. The TaN film showed higher hardness (19.7 GPa) and elastic modulus (254.4 GPa) compared with HA coatings and Ti6Al4V alloys. We evaluated cytocompatibility and osteogenesis activity of the TaN coatings using rabbit bone marrow stromal cells (BMSCs) cultured on the coated and uncoated samples. The biocompatibility of the films and their effect on cell proliferation were examined by live/dead cell staining and CCK-8 assay. SEM and cytoskeleton fluorescent staining were used to observe the cell adhesion and morphology on different samples. The effect of the film on osteoblastic activity was assessed by calcium nodule staining and alkaline phosphatase quantitative assays. We demonstrate that TaN film can enhance the adhesion, proliferation, and differentiation of BMSCs. These results suggest that TaN film prepared by magnetron sputtering has great potential to be applied in orthopedics.

A proper biological microenvironment conducive to tissue repair and regeneration, while the bioimplant interface directly affects the local microenvironment. In this study, to improve the biological microenvironment, a nanosized tantalum boride (Ta-B) was coated on a titanium alloy substrate (Ti6Al4V, TC4) using magnetron cosputtering. The sample surface was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). To investigate the effects of tantalum boride coating on the microenvironment, rabbit bone marrow stromal cells (BMSCs), and RAW 264.7 cells were respectively seeded on the sample surface and relevant experiments were conducted in vitro. The pure tantalum coating (Ta) and naked TC4 were prepared as controls. Our results showed that the Ta-B coating enhanced cell proliferation and adhesion and inhibited the inflammatory response. Findings of alkaline phosphatase (ALP) staining, alizarin red staining and real-time PCR for osteoblastic gene expression indicated that Ta-B and Ta coating improve the osteogenesis, in which Ta-B coating showed higher osteogenesis than Ta coating. Thus, this study suggests that Ta-B coating with excellent biocompatibility could have new applications for wound healing in bone tissue engineering.

Yun’an Qing,1 Lin Cheng,2 Ruiyan Li,1 Guancong Liu,1 Yanbo Zhang,1 Xiongfeng Tang,1 Jincheng Wang,1 He Liu,1 Yanguo Qin1 1Orthopaedic Medical Center, The Second Hospital of Jilin University, Changchun 130041, People’s Republic of China; 2Department of Obstetrics and Gynecology, The Second Hospital of Jilin University, Changchun 130041, People’s Republic of China Abstract: Infection, as a common postoperative complication of orthopedic surgery, is the main reason leading to implant failure. Silver nanoparticles (AgNPs) are considered as a promising antibacterial agent and always used to modify orthopedic implants to prevent infection. To optimize the implants in a reasonable manner, it is critical for us to know the specific antibacterial mechanism, which is still unclear. In this review, we analyzed the potential antibacterial mechanisms of AgNPs, and the influences of AgNPs on osteogenic-related cells, including cellular adhesion, proliferation, and differentiation, were also discussed. In addition, methods to enhance biocompatibility of AgNPs as well as advanced implants modifications technologies were also summarized. Keywords: antibacterial mechanism, biocompatibility, osteogenic-related cells, orthopedic implants, silver nanoparticles, surface modification