The present study focuses on an in-depth investigation at the molecular level of in situ crosslinked gelatin hydrogel by oxidized carboxymethylcellulose (OCMC), intended for biomedical purposes. The crosslinking parameters, namely the crosslinking temperature, crosslinking time and the amount of crosslinker, were varied. The surface and bulk properties were investigated to construct a representative model postulating the interaction of gelatin and OCMC encompassing their physical and covalent linking which determines the properties of the hydrogel. It was inferred that covalent crosslinking facilitates the interfacial interaction between gelatin and OCMC which beyond 30% OCMC composition is impeded due to depletion: microdomain formation leading to phase separation. This study might enable the fabrication of tunable hydrogel with crosslinking parameters in accordance with its purpose. The preliminary biocompatibility studies of the hydrogel conclude that the crosslinked hydrogel generates favourable conditions for cells to adhere and proliferate showing potential for biomedical purposes. © 2016 Society of Chemical Industry.