Oxidation-mediated scaffold engineering of hyaluronic acid-based microcarriers enhances corneal stromal regeneration

The functional design of scaffolding biomaterials with potent capabilities of promoting cell adhesion and proliferation is critically important for tissue repair and regeneration. Here, we exploit the effects of oxidation level of aldehyde hyaluronic acid (oHA) on gelatin microcarriers for repairing corneal injuries. Specifically, high oxidation levels can endow the microcarrier surface with large oHA grafting amount, smooth topography, and strong stiffness, consequently formulating biocompatible scaffolding materials with superior affinities for keratocyte attachment and growth. In a rabbit model of corneal alkali burn injury, single intracorneal injection of keratocytes/functionalized microcarriers with an appropriate oxidation level could effectively reduce corneal swelling (similar to 62-fold improvement), recover similar to 94% collagen production and similar to 89% keratocan expression, and repair disordered collagenous stromal architecture after 4 weeks. These findings on the oxidation level effects of the aldehyde polysaccharide show a great potential use in the development of advanced scaffolds for efficient tissue engineering.