In Situ Formation of Hydrogel Wound Dressing Based on Carboxymethyl Chitin/Tannic Acid for Promoting Skin Wound Healing.

Triggering the healing process of drug-resistant bacteria-infected wounds has attracted great attention due to global morbidity that may induce gangrene, amputation, and even death. Here, a chitin derivative, carboxymethyl chitosan (CMC), tannic acid (TA), and Cu2+ were used for hydrogel engineering. Using sodium bicarbonate as the neutralizer and reductant, hydrogen bonds between CMC and TA and in situ Cu(OH)2 generation via ion coordination force between Cu2+ and TA facilitated the synthesis of CMC/TA/Cu hydrogel. Cu2+ and TA release, cytotoxicity, in vitro cell migration, angiogenesis, and antidrug-resistant bacteria were measured. Besides, wound closure was evaluated in vivo using the methicillin-resistant Staphylococcus aureus (MRSA)-infected excisional dermal wound mouse model. Negligible toxicity was observed both in vitro and in vivo. Dermal cell migration and angiogenesis were significantly enhanced. In vivo, the CMC/TA/Cu hydrogel induced effective re-epithelialization, collagen deposition, inflammatory alleviation, and MRSA inhibition during wound repair in mice. All these results confirmed that the CMC/TA/Cu hydrogel is a promising novel dressing for chronic wound healing in clinic.

Progress of Mesoporous Silica Coated Gold Nanorods for Biological Imaging and Cancer Therapy.

For unique surface plasmon absorption and fluorescence characteristics, gold nanorods have been developed and widely employed in the biomedical field. However, limitations still exist due their low specific surface area, instability and tendency agglomerate in cytoplasm. Mesoporous silica materials have been broadly applied in field of catalysts, adsorbents, nanoreactors, and drug carriers due to its unique mesoporous structure, highly comparative surface area, good stability and biocompatibility. Therefore, coating gold nanorods with a dendritic mesopore channels can effectively prevent particle agglomeration, while increasing the specific surface area and drug loading efficiency. This review discusses the advancements of GNR@MSN in synthetic process, bio-imaging technique and tumor therapy. Additionally, the further application of GNR@MSN in imaging-guided treatment modalities is explored, while its promising superior application prospect is highlighted. Finally, the issues related to in vivo studies are critically examined for facilitating the transition of this promising nanoplatform into clinical trials.