To develop a platform for
tumor chemotherapy,
poly(acrylic acid-co-methyl methacrylate) microparticles have been synthesized. Carboxylate containing monomers were included to complex therapeutic agents, specifically
cisplatin. Microparticles were prepared by
free radical emulsion polymerization in aqueous media. Particle diameter, zeta-potential, in vitro cytotoxicity, and in vivo acute toxicity were characterized for both
cisplatin-loaded microparticles and unloaded microparticles. In vitro cytotoxicity and FT-IR were used to characterize
cisplatin released from
cisplatin-loaded microparticles.
Acrylic acid feed mole fraction determined several key microparticle properties, including particle size, zeta-potential, and yield. A burst release of
cisplatin (40%) in the first day was followed by a zero-order release phase. The interaction between
cisplatin and microparticles allowed approximately 20% additional
cisplatin release in the next five days.
Cisplatin-loaded and unloaded microparticles are non-toxic (LC50>15 mM) to the cell line used in in vitro tests.
Cisplatin released from
cisplatin-loaded microparticles retained activity, but that activity was slightly lower than freshly prepared
cisplatin. Other than a slight reduction in
cisplatin activity, microparticles exhibited low in vivo acute toxicity (LD50>170 mg/kg), which suggests that this
hydrogel particulate system and the
hydrogel complexation mechanism should further be studied for
drug delivery.