The present invention relates to the synthesis of porous polymer scaffold from polyethyleneglycol-polyurethane having castor oil linkages under controlled conditions and their use as stem cell delivery vehicles thereby accelerating the tissue regeneration process. The present invention further studies the biodegradability, stability and biocompatibility of porous polymer scaffolds in varios cell lines and primary bone marrow stem cells. Particularly the present invention further relates to the physio-chemical characterization of the porous polymer scaffolds.

A natural oil derived blocked prepolymer is a reaction product of a composition including an isocyanate terminated prepolymer that is the reaction product of a mixture that has at least one or more polyols including at least one polyol having a secondary amine initiator or a tertiary amine initiator and a stoichiometric excess of one or more organic polyisocyanate components of which the stoichiometric excess of isocyanate to alcohol moieties (NCO:OH) is from 1.1:1 to 4:1, and a natural oil derived blocking agent. The viscosity of the natural oil derived blocked prepolymer is from 50,000 Pa*s to 300,000 Pa*s. An acrylic plastisol composition comprises the natural oil blocked prepolymer, one or more acrylic powders, one or more plasticizers, one or more amine crosslinkers, and optionally, one or more fillers.