Bioactive Agent Delivery


Novel biodegradable and biocompatible polymeric carriers can serve as a new mode of administration of the drugs to improve pharmacodynamic parameters, efficacy and to increase general tolerance of the treatment. Therapeutic microparticles containing various agents of interest have been configured as microspheres, nanospheres, microcapsules, and liposomes. Among these nanoparticules are solid biocompatible polymeric particles into which drugs can be incorporated or to which drugs can be bound. In a typical application anti-leukemic enzyme L-asparaginase was entrapped in poly(hydroxybutyrate-co-hydroxyvalerate) nanocapsules. The half-life of nanoparticulate drug carriers in vivo was modified by increasing surface hydrophilicity, attachment of hydrophilic polymers to create steric barriers. Heparin conjugation and plasma treatments are examples of modification along this line.

Antibiotic, analgesic, anesthetic, and anticancer agent delivery from extruded fibers and cold-molded rods is another method of controlled delivery being studied along with pH responsive NIPAM based systems.

Gene delivery via DNA-polyelectrolyte complexes free or entrapped in polyelectrolyte shells are being developed with the aim of improving the transfection capabilities with the ultimate aim of developing vaccines.