Semi-IPN hydrogel based on scleroglucan and alginate: drug delivery behaviour and mechanical characterization

This paper deals with the characterization of the semi-IPN based on a scleroglucan/borax hydrogel with interspersed alginate chains, with regard to both its physicochemical properties and its suitability for modified drug release formulations. In particular, the feasibility of a drug delivery system based on this new polysaccharidic matrix was explored in terms of ability of the network to discriminate the releases of model drugs with different steric hindrance. The investigated mechanical properties of the semi-IPN hydrogel evidenced the relevant effect of alginate on the scleroglucan/borax system: experiments in shear oscillation regime showed that the rheological properties of the polymeric system are more than additive; in fact it has been observed that alginate induces an increase in the hydrogel storage modulus of an order of magnitude. Optical data collected in circular dichroic experiments showed no interactions, at molecular level, between scleroglucan and alginate in solution, irrespective of the presence of borax. The studied semi-IPN is thermo irreversible in the temperature range that was explored.