Enhancing ZnO-NP Antibacterial and Osteogenesis Properties in Orthopedic Applications: A Review.

Prosthesis-associated infections and aseptic loosening are major causes of implant failure. There is an urgent need to improve the antibacterial ability and osseointegration of orthopedic implants. Zinc oxide nanoparticles (ZnO-NPs) are a common type of zinc-containing metal oxide nanoparticles that have been widely studied in many fields, such as food packaging, pollution treatment, and biomedicine. The ZnO-NPs have low toxicity and good biological functions, as well as antibacterial, anticancer, and osteogenic capabilities. Furthermore, ZnO-NPs can be easily obtained through various methods. Among them, green preparation methods can improve the bioactivity of ZnO-NPs and strengthen their potential application in the biological field. This review discusses the antibacterial abilities of ZnO-NPs, including mechanisms and influencing factors. The toxicity and shortcomings of anticancer applications are summarized. Furthermore, osteogenic mechanisms and synergy with other materials are introduced. Green preparation methods are also briefly reviewed.

Advanced Black Phosphorus Nanomaterials for Bone Regeneration.

Bone regeneration remains a great clinical challenge. Two-dimensional materials, especially graphene and its derivative graphene oxide, have been widely used for bone regeneration. Since its discovery in 2014, black phosphorus (BP) nanomaterials including BP nanosheets and BP quantum dots have attracted considerable scientific attention and are considered as prospective graphene substitutes. BP nanomaterials exhibit numerous advantages such as excellent optical and mechanical properties, electrical conductivity, excellent biocompatibility, and good biodegradation, all of which make them particularly attractive in biomedicine. In this review, we comprehensively summarize recent advances of BP-based nanomaterials in bone regeneration. The advantages are reviewed, the different synthesis methods of BP are summarized, and the applications to promote bone regeneration are highlighted. Finally, the existing challenges and perspectives of BP in bone regeneration are briefly discussed.

Tantalum boride as a biocompatible coating to improve osteogenesis of the bionano interface.

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.

Enhanced antibacterial properties of orthopedic implants by titanium nanotube surface modification: a review of current techniques.

Prosthesis-associated infections are one of the main causes of implant failure; thus it is important to enhance the long-term antibacterial ability of orthopedic implants. Titanium dioxide nanotubes (TNTs) are biomaterials with good physicochemical properties and biocompatibility. Owing to their inherent antibacterial and drug-loading ability, the antibacterial application of TNTs has received increasing attention. In this review, the process of TNT anodizing fabrication is summarized. Also, the mechanism and the influencing factors of the antibacterial property of bare TNTs are explored. Furthermore, different antibacterial strategies for carrying drugs, as well as modifications to prolong the antibacterial effect and reduce drug-related toxicity are discussed. In addition, antibacterial systems based on TNTs that can automatically respond to infection are introduced. Finally, the currently faced problems are reviewed and potential solutions are proposed. This review provides new insight on TNT fabrication and summarizes the most advanced antibacterial strategies involving TNTs for the enhancement of long-term antibacterial ability and reduction of toxicity.

Potential antibacterial mechanism of silver nanoparticles and the optimization of orthopedic implants by advanced modification technologies.

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.

Adhesion and Proliferation of Osteoblast-Like Cells on Porous Polyetherimide Scaffolds.

The purpose of this work was to investigate the porous polyetherimide scaffold (P-PEIs) as an alternative biopolymer for bone tissue engineering. The P-PEIs was fabricated via solvent casting and particulate leaching technique. The morphology, phase composition, roughness, hydrophilicity, and biocompatibility of P-PEIs were evaluated and compared with polyetherimide (PEI) and Ti6Al4V disks. P-PEIs showed a biomimetic porous structure with a modulus of 78.95 ± 2.30 MPa. The water contact angle of P-PEIs was 75.4 ± 3.39°, which suggested that P-PEIs had a wettability surface. Moreover, P-PEIs provides a feasible environment for cell adhesion and proliferation. The relative cell adhesion capability and the cell morphology on P-PEIs were better than PEI and Ti6Al4V samples. Furthermore, the MC3T3-E1 cells on P-PEIs showed faster proliferation rate than other groups. It was revealed that the P-PEIs could be a potential material for the application of bone regeneration.

A comprehensive overview of exosomes in ovarian cancer: emerging biomarkers and therapeutic strategies.

Exosomes are nanoparticles(40-100 nm) secreted by most cells in the body, which can be isolated from several types of extracellular fluids. It has been shown that exosomes play a key role in intercellular communication and in transportation of genetic information. Emerging evidence shows that exosomes are mediators of metastasis in tumour cells, stromal cells and the extracellular matrix component through the shuttling of cargo, such as proteins, lipids, RNAs, double-stranded DNAs, non-transcribed RNAs, and microRNAs. This phenomenon has been indicated in both tumourigenesis and drug resistance. In this review, we introduce new methods of exosome extraction, focusing on the emerging role of exosomes in ovarian cancer, and discuss their potential clinical applications.