A drug delivery system based on alginate microspheres:: Mass-transport test and in vitro validation

This paper presents a drug delivery system based on alginate microspheres. The biocompatibility, the flexibility in size and shape, the ability to entrap biomolecules as well as cells make alginate based systems ideal for in vivo drug delivery. Specifically, considering the target application of neural regeneration and the issue of neuroprotection for the development of innovative neuroprostheses, the authors describe a system for controlled release of Netrin-1, an axonal guidance protein. Microspheres dimensioning (based on specifications of drug release time and release modality), microspheres realization, and mass transport tests are described. The release efficiency is finally assessed by in vitro experiments of axonal guidance performed on embryonic neuronal cells. Preliminary results show that neuronal axons grow approaching the Netrin-1 source, thus indicating an efficient entrapment and release of the protein in the microspheres, in agreement with the microsphere modelling described before.