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 (~62-fold improvement), recover ~94% collagen production and ~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. [Display omitted] •Oxidized hyaluronan-grafted microcarrier was developed as injectable cell scaffold.•Oxidation level of polysaccharide was critical to microcarrier surface engineering.•High oxidation degree of microcarriers promoted keratocyte growth and biosynthesis.•Tissue regeneration performance strongly depended on oxidation level of hyaluronan.•Cell-containing microcarriers showed promises for efficient corneal stromal repair.