3D Printing of Diatomite Incorporated Composite Scaffolds for Skin Repair of Deep Burn Wounds

Deep burn injury always causes severe damage of vascular network and collagen matrix followed by delayed wound healing process. In this study, natural diatomite (DE) microparticles with porous nanostructure were separated based on the particles size through a dry sieving method and combined with gelatin methacryloyl (GelMA) hydrogel to form a bioactive composite ink. The DE-containing inorganic/organic composite scaffolds, which were successfully prepared through three-dimensional (3D) printing technology, were used as functional burn wound dressings. The scaffolds incorporated with DE are of great benefit to several cellular activities, including cell spreading, proliferation, and angiogenesis-related gene expression in vitro, which can mainly be attributed to the positive effect of bioactive silicon (Si) ions released from the embedded DE. Moreover, due to establishment of bioactive ionic environment, the deep burn wounds treated with 3D-printed DE incorporated scaffolds exhibited rapid wound healing rate, enhanced collagen deposition, and dense blood vessel formation in vivo. Therefore, the present study demonstrates that the cost-effective DE can be used as biocompatible Si source to significantly promote the bioactivities of wound dressings for effective tissue regeneration.