Gelatin microspheres and sponges for delivery of macromolecules

Gelatin microspheres and gelatin sponges were prepared by coacervation and freeze drying techniques, respectively. Both systems were crosslinked with glutaraldehyde. The mean diameter of the microspheres were in the range of 40-80 microm and the mean pore size of the sponges was 130-220 microm depending on the preparation conditions. Bovine serum albumin (BSA) was added into the preparation solutions and entrapped in the microspheres and sponges. BSA addition to sponges was also achieved by addition of BSA-containing microspheres into the sponges. The release kinetics of BSA from the prepared systems were examined. Studies demonstrated that release is dependent on the amount of BSA present in the system and crosslinking densities of microspheres. It was concluded that gelatin microspheres and gelatin sponges are promising carrier matrices for macromolecules.