The present disclosure relates to a composition of at least one predominantly positively charged polyelectrolyte polymer and at least one predominantly negatively charged polyelectrolyte polymer, a preferred composition comprises poly-L-lysine and a gellan gum, preferably a methacrylate gellan gum. The present subject-matter further relates to methods for generating composition of the present disclosure and to uses of a mixture according to the disclosure for biomedical applications such as cellular and acellular systems for tissue engineering and regenerative medicine applications or as drug delivery systems, for the treatment of several diseases namely diabetes mellitus.