Biodegradable metals are promising candidates for bone defect repair. With an evidence-based approach, this study investigated and analyzed the performance and degradation properties of biodegradable metals in animal models for bone defect repair to explore their potential clinical translation. Animal studies on bone defect repair with biodegradable metals in comparison with other traditional biomaterials were reviewed. Data was carefully collected after identification of population, intervention, comparison, outcome, and study design (PICOS), and following the inclusion criteria of biodegradable metals in animal studies. 30 publications on pure Mg, Mg alloys, pure Zn and Zn alloys were finally included after extraction from a collected database of 2543 publications. A qualitative systematic review and a quantitative meta-analysis were performed. Given the heterogeneity in animal model, anatomical site and critical size defect (CSD), biodegradable metals exhibited mixed effects on bone defect repair and degradation in animal studies in comparison with traditional non-degradable metals, biodegradable polymers, bioceramics, and autogenous bone grafts. The results indicated that there were limitations in the experimental design of the included studies, and quality of the evidence presented by the studies was very low. To enhance clinical translation of biodegradable metals, evidence-based research with data validity is needed. Future studies should adopt standardized experimental protocols in investigating the effects of biodegradable metals on bone defect repair with animal models.The treatment of large-area bone defects still faces many difficulties and challenges. Here, we developed a blood clot delivery platform loaded with BMP-2 protein (BMP-2@BC) for enhanced bone regeneration. Blood clot gel platform as natural biomaterials can be engineered from autologous blood. Once implanted into the large bone defect site, it can be used for BMP-2 local delivery, as well as modulating osteoimmunology by recruiting a great number of macrophages and regulating their polarization at different stages. Moreover, due to the deep-red color of blood clot gel, mild localized hyperthermia under laser irradiation further accelerated bone repair and regeneration. We find that the immune niche within the bone defect microenvironment can be modulated in a controllable manner by the blood clots implantation and laser treatment. We further demonstrate that the newly formed bone covered almost 95% of the skull defect area by our strategy in both mice and rat disease models. Due to the great biocompatibility, photothermal potential, and osteoimmunomodulation capacity, such technology shows great promise to be used in further clinical translation.A novel biodegradable metal system, ZnLiCa ternary alloys, were systematically investigated both in vitro and in vivo. The ultimate tensile strength (UTS) of Zn0.8Li0.1Ca alloy reached 567.60 ± 9.56 MPa, which is comparable to pure Ti, one of the most common material used in orthopedics. The elongation of Zn0.8Li0.1Ca is 27.82 ± 18.35%, which is the highest among the ZnLiCa alloys. The in vitro degradation rate of Zn0.8Li0.1Ca alloy in simulated body fluid (SBF) showed significant acceleration than that of pure Zn. CCK-8 tests and hemocompatibility tests manifested that ZnLiCa alloys exhibit good biocompatibility. Real-time PCR showed that Zn0.8Li0.1Ca alloy successfully stimulated the expressions of osteogenesis-related genes (ALP, COL-1, OCN and Runx-2), especially the OCN. An in vivo implantation was conducted in the radius of New Zealand rabbits for 24 weeks, aiming to treat the bone defects. The Micro-CT and histological evaluations proved that the regeneration of bone defect was faster within the Zn0.8Li0.1Ca alloy scaffold than the pure Ti scaffold. Zn0.8Li0.1Ca alloy showed great potential to be applied in orthopedics, especially in the load-bearing sites.Cell transplantation is an effective strategy to improve the repair effect of nerve guide conduits (NGCs). However, problems such as low loading efficiency and cell anoikis undermine the outcomes. Microcarriers are efficient 3D cell culture scaffolds, which can also prevent cell anoikis by providing substrate for adhesion during transplantation. Here, we demonstrate for the first time microcarrier-based cell transplantation in peripheral nerve repair. We first prepared macroporous chitosan microcarriers (CSMCs) by the emulsion-phase separation method, and then decorated the CSMCs with polylysine (pl-CSMCs) to improve cell affinity. We then loaded the pl-CSMCs with adipose-derived stem cells (ADSCs) and injected them into electrospun polycaprolactone/chitosan NGCs to repair rat sciatic nerve defects. The ADSCs-laden pl-CSMCs effectively improved nerve regeneration as demonstrated by evaluation of histology, motor function recovery, electrophysiology, and gastrocnemius recovery. With efficient cell transplantation, convenient operation, and the multiple merits of ADSCs, the ADSCs-laden pl-CSMCs hold good potential in peripheral nerve repair.Osteochondral repair remains a major challenge in current clinical practice despite significant advances in tissue engineering. In particular, the lateral integration of neocartilage into surrounding native cartilage is a difficult and inadequately addressed problem that determines the success of tissue repair. Here, a novel design of an integral bilayer scaffold combined with a photocurable silk sealant for osteochondral repair is reported. First, we fabricated a bilayer silk scaffold with a cartilage layer resembling native cartilage in surface morphology and mechanical strength and a BMP-2-loaded porous subchondral bone layer that facilitated the osteogenic differentiation of BMSCs. Second, a TGF-β3-loaded methacrylated silk fibroin sealant (Sil-MA) exhibiting biocompatibility and good adhesive properties was developed and confirmed to promote chondrocyte migration and differentiation. Importantly, this TGF-β3-loaded Sil-MA hydrogel provided a bridge between the cartilage layer of the scaffold and the surrounding cartilage and then guided new cartilage to grow towards and replace the degraded cartilage layer from the surrounding native cartilage in the early stage of knee repair. Thus, osteochondral regeneration and superior lateral integration were achieved in vivo by using this composite. selleck chemical These results demonstrate that the new approach of marginal sealing around the cartilage layer of bilayer scaffolds with Sil-MA hydrogel has tremendous potential for clinical use in osteochondral regeneration.