Nanocatalytic Hydrogel with Rapid Photodisinfection and Robust Adhesion for Fortified Cutaneous Regeneration.

Chronic inflammation caused by invasive bacterial infections severely interferes with the normal healing process of skin regeneration. Hypoxia of the infection microenvironment (IME) seriously affects the antibacterial effect of photodynamic therapy in phototherapy. To address this serious issue, a nanocatalytic hydrogel with an enhanced phototherapy effect consisting of a hydrogel polyvinyl alcohol (PVA) scaffold, MXene/CuS bio-heterojunction, and polydopamine (PDA) for photothermal antibacterial effects and promoting skin regeneration is designed. The MXene/CuS bio-heterojunction has a benign photothermal effect. Singlet oxygen (1O2) and hydroxyl radicals (·OH) were generated under near-infrared light, which made the hydrogel system have good antioxidant and antibacterial properties. The addition of PDA further improves the biocompatibility and endows the nanocatalytic hydrogel with adhesion. Additionally, in vivo assays display that the nanocatalytic hydrogel has good skin regeneration ability, including ability to kill bacteria, and promotes capillary angiogenesis and collagen deposition. This work proposes an approach for nanocatalyzed hydrogels with an activated IME response to treat wound infections by enhancing the phototherapeutic effects.

[The surface modification of eguus asinus augment fibroblast adhesion and proliferation on silk fibroin materials].

Eguus asinus is one of the rare Chinese drugs famous for promoting blood circulation. In this experiment, it was employed to modify the silk fibroin (SF) by physical blending. Mouse embryonic fibroblasts NIH-3T3 were seeded on pure and modified SF surfaces. The morphological changes of cell on SF surfaces were characterized by optical microscope images. The cell adhesion diameter, the attachment force (F) of a single cell and cell proliferation on SF surfaces were measured by micropipette aspiration system and MTT assay. The results indicated that the fibroblasts seeded on modified SF had larger cell adhesion area, stronger initial attachment force and higher cell proliferation than did the pure SF. In conclusion, eguus asinus improved the adhesion and proliferation of fibroblasts on SF. The research promoted the further use of Chinese drug eguus asinus in tissue engineering.

The anticoagulant ability of ferulic acid and its applications for improving the blood compatibility of silk fibroin.

The hemocompatibility of silk fibroin (SF) was improved with ferulic acid (FA) by graft polymerization. Ferulic acid is an active ingredient of many Chinese herbal medicines, such as Chuanxiong (Rhizoma ligustici wallichii), Danggui (Angelica sinensis) and Awei (Asafoetida giantfennel), which have been used to treat cardiovascular diseases by Chinese physicians for thousands of years. The inhibitory functions of FA on blood coagulation and erythrocyte agglutination were first characterized by a Lee-White test tube method and a micropipette technique, respectively. Then, FA was immobilized on SF by graft polymerization and the surface composition of modified SF was characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR), x-ray photoelectron spectroscopy (XPS) and optical microscopy. The anticoagulant activity of modified SF was assessed, respectively, by in vitro clotting time measurements on a photo-optical clot detection instrument and with the Lee-White test tube method. The test results indicated that in comparison to untreated SF, the anticoagulant activity of modified SF has been improved significantly. Moreover, the SF surface composition is altered by FA but its beta-sheet conformation is not disturbed.