The diabetic wounds do not heal easily in part because they are susceptible to infection due to environmental influences. Wound dressing is crucial to wound healing, as it can basically protect the wound from external damages and provide a suitable microenvironment for tissue regeneration. In this study, a double-layer membrane that consists of chitosan sponge and decellularized bovine amniotic membrane (dBAM) has been developed by freeze-casting method. The results showed that the porous structure of the sponge layer improved the performances of blood coagulation and swelling. The dense dBAM can optimize the mechanical property of wound dressing. In vitro studies revealed that the bilayer membrane had favorable biocompatible, especially for human foreskin fibroblast cells (HFF-1) cell adhesion and proliferation. Moreover, the full-thickness skin defects of diabetic model mice that treated with bilayer membrane showed over 80% closure in 8 days. Our findings imply that the double-layer dressing has great potentials to be used in diabetic patients.

Multidrug resistance (MDR) is a key factor in chemotherapy failure and tumor recurrence. The inhibition of drug efflux and autophagy play important roles in MDR therapy. Herein, a multifunctional delivery system (HA-MIL-125@DVMA) was prepared for synergistically reverse tumor MDR. Tumor-targeted hollow MIL-125-Ti nanoparticles were used to load the doxorubicin–vitamin E succinate (DV) prodrug and 3-methyladenine (3-MA) to enhance reverse MDR effects. The pH-sensitive DV can kill tumor cells and inhibit P-gp-mediated drug efflux, and 3-MA can inhibit autophagy. HA-MIL-125@DVMA had uniformly distributed particle size and high drug-load content. The nanoparticles could effectively release the drugs into tumor microenvironment due to the rapid hydrazone bond-breaking under low pH conditions, resulting in a high cumulative release rate. In in vitro cellular experiments, the accumulation of HA-MIL-125@DVMA and HA-MIL-125@DV in MCF-7/ADR cells was significantly higher than that in the control groups. Moreover, the nanoparticles significantly inhibited drug efflux in the cells, ensuring the accumulation of the drugs in cell cytoplasm and causing drug-resistant cells’ death. Importantly, HA-MIL-125@DVMA effectively inhibited tumor growth without changes in body weight in tumor-bearing mice. In summary, the combination of the acid-sensitive prodrug DV and autophagy inhibitor 3-MA in a HA-MIL-125 nanocarrier can enhance the antitumor effect and reverse tumor MDR.