Double-network composites based on inorganic fillers reinforced dextran-based hydrogel with high strength

Abstract

The biodegradable hydrogels with a 3D network structure have potential applications in bone tissue engineering. Here, inspired by natural bone, the novel organic-inorganic composites (GelMPC-x) with high compressive strength are designed via adding magnesium oxide/calcium dihydrogen phosphate (MPC) powders into the oxidized dextran/gelatin (OD/Gel) hydrogel. GelMPC-x composites can trigger the gelation of OD/Gel hydrogel through an acid-alkaline reaction between magnesium oxide and calcium dihydrogen phosphate, thus forming an organic-inorganic double network. The cross-linked network between oxidized dextran and gelatin, and the multiple weak interactions between OD/Gel hydrogel and MPC enable the composites to have remarkable compressive strength (77-652 kPa) at the strain of 44 %. More importantly, the composites with appropriate MPC content possess superior injectability, high porosity, and excellent cytocompatibility. This work provides guidelines for the preparation of oxidized dextran-based composite hydrogels with enhanced mechanical performance.

Keywords: Calcium dihydrogen phosphate; Calcium dihydrogen phosphate (PubChem CID: 21655728); Calcium hydrogen phosphate dihydrate (PubChem CID: 104805); Composite hydrogels; Dextran (PubChem CID: 4125253); Gelatin; Magnesium hydrogen phosphate trihydrate (PubChem CID: 16204530); Magnesium oxide; Magnesium oxide (PubChem CID: 14792); Oxidized dextran; Sodium periodate (PubChem CID: 23667635).