The functional response of alginate-gelatin-nanocrystalline cellulose injectable hydrogels toward delivery of cells and bioactive molecules

Hybrid injectable hydrogels comprising of alginate, gelatin, and nanocrystalline cellulose (NCC) were conceived and processed through adaptation of interpenetrated network of alginate-gelatin, ionic crosslinking of alginate, and supramolecular interaction approach. The design of hybrid hydrogels was based on the hypothesis that it provides an environment that is favorable for cell proliferation, exchange of nutrients via porous structure, and are characterized by mechanical properties that closely resemble the native tissue. This aspect is important for the delivery of cells or biomolecules in bone tissue engineering. The hybrid hydrogels exhibited moderate swelling behavior on formation, and the porous structure of hydrogels as imaged via SEM was envisaged to facilitate easy migration of cells and rapid transportation of biomolecules. The hybrid hydrogels exhibited desired mechanical properties and were biocompatible as confirmed though MTT assay of fibroblasts. Interestingly, osteoblasts cultured within hydrogel using bone morphogenetic protein (BMP)-2 demonstrated the capability for encapsulation of cells and induced cell differentiation. The nanocrystalline cellulose significant impacted degradation and interaction between hydrogels and cells. Statement of Significance The study fundamentally explores a hypothesis driven novel hybrid hydrogel that provides an environment for favorable growth and proliferation of cells, exchange of nutrients and mechanical properties that closely match the native tissue. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.