Preparation of Recombinant Human Collagen III Protein Hydrogels with Sustained Release of Extracellular Vesicles for Skin Wound Healing

Abstract

Existing treatment methods encounter difficulties in effectively promoting skin wound healing, making this a serious challenge for clinical treatment. Extracellular vesicles (EVs) secreted by stem cells have been proven to contribute to the regeneration and repair of wound tissue, but they cannot be targeted and sustained, which seriously limits their current therapeutic potential. The recombinant human collagen III protein (rhCol III) has the advantages of good water solubility, an absence of hidden viral dangers, a low rejection rate and a stable production process. In order to achieve a site-specific sustained release of EVs, we prepared a rhCol III hydrogel by cross-linking with transglutaminase (TGase) from Streptomyces mobaraensis, which has a uniform pore size and good biocompatibility. The release profile of the rhCol III-EVs hydrogel confirmed that the rhCol III hydrogel could slowly release EVs into the external environment. Herein, the rhCol III-EVs hydrogel effectively promoted macrophage changing from type M1 to type M2, the migration ability of L929 cells and the angiogenesis of human umbilical vein endothelial cells (HUVECs). Furthermore, the rhCol III-EVs hydrogel is shown to promote wound healing by inhibiting the inflammatory response and promoting cell proliferation and angiogenesis in a diabetic rat skin injury model. The reported results indicate that the rhCol III-EVs hydrogel could be used as a new biological material for EV delivery, and has a significant application value in skin wound healing.

Application of Collagen-Based Hydrogel in Skin Wound Healing

“…This approach usually involves the reaction between the photosensitizer and UV light to produce intra- and intermolecular links within the collagen fibers. The UV–riboflavin or UV–GelMA-induced crosslinking reaction of collagen is commonly used in the treatment of skin tissue [ 49 , 50 , 51 ].…”

“…Laccase (LAC) is a multi-copper-containing oxidase. Recently, the fact that collagen can be further stabilized by crosslinking with LAC has been demonstrated [ 49 ].…”

“…EVs are speculated to accelerate the overall wound healing process, mainly by activating anti-inflammatory pathways such as the AKT/ERK and WNT pathways [ 89 ]. Incorporating Evs into collagen hydrogels proved to have a significant application value in skin wound healing [ 49 ]. The study found that rhCol III hydrogel can be successfully loaded with HUCMSCs-secreted EVs in order to obtain a hydrogel material with a sustained-release function.…”

Extracellular Vesicle-Based Hydrogels for Wound Healing Applications

“…All these studies have achieved a synergic association between EVs and hydrogels in terms of their functional and wound-healing properties [ 70 , 71 , 72 , 73 ]. However, as mentioned before, EV conservation requires improvement before reaching the clinics.…”

“…For this reason, EV investigation requires working in the freshest conditions possible and avoiding freeze-thaw cycles. To improve storage conditions and the stability of EVs at room and physiological temperatures, EVs can be loaded into hydrogels that can maintain pH levels and colloidal properties [ 71 , 74 , 75 ]. Additionally, by regulating hydrogel properties such as porosity or degradation rate, it is possible to optimize the dose administered and EV release [ 76 ].…”