Hybrid gelatin/oxidized chondroitin sulfate hydrogels incorporating bioactive glass nanoparticles with enhanced mechanical properties, mineralization, and osteogenic differentiation

Abstract

Biopolymer based hydrogels are characteristic of their biocompatibility and capability of mimicking extracellular matrix structure to support cellular behavior. However, these hydrogels suffer from low mechanical properties, uncontrolled degradation, and insufficient osteogenic activity, which limits their applications in bone regeneration. In this study, we developed hybrid gelatin (Gel)/oxidized chondroitin sulfate (OCS) hydrogels that incorporated mesoporous bioactive glass nanoparticles (MBGNs) as bioactive fillers for bone regeneration. Gel-OCS hydrogels could be self-crosslinked in situ under physiological conditions in the presence of borax. The incorporation of MBGNs enhanced the crosslinking and accelerated the gelation. The gelation time decreased with increasing the concentration of MBGNs added. Incorporation of MBGNs in the hydrogels significantly improved the mechanical properties in terms of enhanced storage modulus and compressive strength. The injectability of the hydrogels was not significantly affected by the MBGN incorporation. Also, the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells in vitro and rat cranial defect restoration in vivo were significantly promoted by the hydrogels in the presence of MBGNs. The hybrid Gel-OCS/MBGN hydrogels show promising potential as injectable biomaterials or scaffolds for bone regeneration/repair applications given their tunable degradation and gelation behavior as well as favorable mechanical behavior and osteogenic activities.

Cutting Edge Endogenous Promoting and Exogenous Driven Strategies for Bone Regeneration

“…However, biopolymer-based hydrogels suffer from low mechanical properties, uncontrolled degradation, plus insufficient osteogenic activity, which limits their applications in bone regeneration. To overcome these drawbacks, hybrid gelatin/oxidized chondroitin sulfate (OCS) hydrogels have been developed as bioactive fillers [ 74 ]; while chondroitin sulfate is a glycosaminoglycan found in the bone ECM that increases the efficacy of arrangement of certain growth factors (GFs) involved in bone regeneration, gelatin, a water-soluble biocompatible biopolymer, facilitates cell adhesion and biomolecules deposition. Moreover, the incorporation of mesoporous (contains pores with diameters between 2 and 50 nm) bioactive glass nanoparticles (MBGNs) in the hydrogels significantly improve their mechanical properties, as has been demonstrated both in vitro and in vivo through the proliferation and osteogenic differentiation of rat BM-MSCs and rat cranial defect restoration, respectively.…”

Mesoporous Bioactive Glasses Cytocompatibility Assessment: A Review of In Vitro Studies

“…This material will then migrate into the nucleus of the host cells and could induce modification on the gene expression profile. From another perspective, Zhou et al assessed the inflammatory profile of some MBG nanoparticles incorporated in hybrid scaffolds using immunity cells [ 108 ].…”

Biomimetic Mineralization of Tannic Acid-Supplemented HEMA/SBMA Nanocomposite Hydrogels

“…There have been several attempts at designing a production strategy that resolves the issues around hydrogel mineralization, mechanical strength and hydrophobicity with many successful materials being produced, but all require some compromise. One strategy includes the incorporation of inorganic phases, such as calcium phosphate ceramics and bioglass, into hydrogel matrices [ 37 , 38 ]. These inorganic particles act as nucleation sites that enable further mineralization, thus improving the mechanical properties of the composite material [ 37 , 38 ].…”

“…One strategy includes the incorporation of inorganic phases, such as calcium phosphate ceramics and bioglass, into hydrogel matrices [ 37 , 38 ]. These inorganic particles act as nucleation sites that enable further mineralization, thus improving the mechanical properties of the composite material [ 37 , 38 ]. However, the incorporation of these inorganic particles did not have any bonding with the polymer network, which compromises the network elasticity [ 36 ].…”