Development and in vitro cytotoxicity of microparticle drug delivery system for proteins using l-tyrosine polyphosphate

l-Tyrosine polyphosphate (LTP), a “pseudo” poly (amino acid) polymer is characterized by a rapid degradation rate. Subsequently, formulation of a drug delivery system has been investigated by encapsulating fluorescein isothiocyanate–bovine serum albumin (FITC-BSA) within LTP microparticles. Characterization of surface morphology shows a mixture of spherical and discoid particles with a slightly rough surface morphology for all microparticle formulations. Dynamic laser light scattering (DLS) shows a decrease in particle diameters and size distribution upon FITC-BSA encapsulation. LTP microparticles are found to degrade over a period of 7 days, and complete release of FITC-BSA is observed over a period of 6 days. Cytotoxicity evaluation of LTP microparticles indicates that these microparticles do not cause severe cell death in cultured primary human dermal fibroblasts over a period of 10 days. Therefore, the LTP microparticles are promising candidates for short-term protein delivery applications.