A novel sustained release system for aqueous cis-platinum

The authors devised a novel sustained release system for aqueous cis-platinum (CDDP) to study in vitro the degradability of the carrier materials and the release profile of the CDDP. We first prepared fibrin hydrogels with clinically used biomedical materials, and irradiated the gels with ultraviolet (UV)-rays to form gradually degradable drug carriers. We then loaded aqueous CDDP into the carriers under negative pressure. These prepared materials were incubated in fibrinolytic test medium at 37 degrees C for the in vitro studies. The UV-irradiated materials slowly degraded and dissolved within 10-15 days, while non-UV-treated carriers disintegrated in 4-5 days. Each carrier showed a sustained release of CDDP. Most of the CDDP delivered was revealed to be the protein-binding (larger than 10 kDa) form. Free-CDDP was almost nil. The antineoplastic efficacies of this new drug delivery system developed using an original technique are now being investigated.