Department of Bioengineering, Center for Controlled Chemical Delivery, 20 S 2030 E, Rm# 205, Biopolymers Research Building, University of Utah, Salt Lake City, UT 84112, USA.
Abstract:
Novel polymeric delivery systems for the photosensitizer mesochlorin e6 (Mce6) were synthesized to overcome problems of systemic toxicity. A disulfide bond was included to allow for quick release of Mce6 from the N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer backbone once internalized in tumor tissue. The synthesized conjugates demonstrated a time-dependent reductive cleavage with an accompanying increase in the quantum yield of singlet oxygen generation on exposure to DTT. Quicker release kinetics and a higher cytotoxicity in SKOV-3 human ovarian carcinoma cells were obtained as compared to polymer conjugate with a proteolytically cleavable GFLG spacer. These novel conjugates hold promise as clinically relevant drug delivery systems for photodynamic therapy of cancer.