A double-layer microneedle patch DMN@TCH/DFO was prepared and released TCH and DFO to accelerate wound healing through antibacterial and angiogenesis-promoting processes, and provides a new choice for diabetic wound repair.

Hydrophilic surfaces for hydrogels as bone tissue engineering scaffolds are not beneficial for the adsorption of protein and not conducive to the adhesion and growth of cells. In this study, we proposed to use an oxidized sodium alginate–N-succinyl chitosan hydrogel as a bone tissue engineering scaffold material and to overcome this issue by using RGD to modify this kind of hydrogel. The physicochemical properties of the obtained hydrogels were characterized and an in vitro endothelial differentiation and osteogenic differentiation study of bone-marrow-derived mesenchymal stem cells (BMSCs) was conducted to evaluate it. The results showed that the RGD-grafted oxidized sodium alginate–N-succinyl chitosan hydrogel not only had a good degradability but also enhanced cell adhesion and proliferation and promoted endothelial differentiation and osteogenic differentiation of BMSCs. Based on the results, it can be expected that RGD-grafted oxidized sodium alginate–N-succinyl chitosan hydrogel might be an optimal material for bone tissue engineering scaffold whenever it is used alone, or composed with other materials in the future.

In this study, vitamin-based small organic molecules were used as precursors to synthesize carbon dots by means of a hydrothermal approach. The obtained carbon dots presented high luminescence and good cellar-imaging properties when folic acid was used as a precursor and the quantum yield of the carbon dots obtained using the present method was more than 30%. Moreover, green and yellow-green photoluminescence was also successfully achieved by adding the reagents H₃PO₄ and H₂C₂O₄, respectively. The related formation mechanism and photoluminescence emission mechanism of carbon quantum dots were discussed. The present study will open a new possible route for the synthesis of carbon dots with high quality using small organic molecules as precursors.

So far, how to achieve the optimal regenerative repair of large load-bearing bone defects using artificial bone grafts is a huge challenge in clinic. In this study, a strategy of combining osteoinductive biphasic calcium phosphate (BCP) bioceramic scaffolds with intramedullary nail fixation for creating stable osteogenic microenvironment was applied to repair large segmental bone defects (3.0 cm in length) in goat femur model. The material characterization results showed that the BCP scaffold had the initial compressive strength of over 2.0 MPa, and total porosity of 84%. The cell culture experiments demonstrated that the scaffold had the excellent ability to promote the proliferation and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs). The in vivo results showed that the intramedullary nail fixation maintained the initial stability and structural integrity of the implants at early stage, promoting the osteogenic process both guided and induced by the BCP scaffolds. At 9 months postoperatively, good integration between the implants and host bone was observed, and a large amount of newborn bones formed, accompanying with the degradation of the material. At 18 months postoperatively, almost the complete new bone substitution in the defect area was achieved. The maximum bending strength of the repaired bone defects reached to the 100% of normal femur at 18 months post-surgery. Our results demonstrated the good potential of osteoinductive BCP bioceramics in the regenerative repair of large load-bearing bone defects. The current study could provide an effective method to treat the clinical large segmental bone defects.