Abstract:

Hyperbranched poly(sulfone-amine)(PSA) is a novel class of hyperbranched macromolecule. In order to assess its feasibility of using PSA as a drug delivery system, we synthesized PSA-FITC by conjugating a fluorescent diagnostic agent fluorescein isothiocyanate(FITC) to the terminal amino groups of PSA covalently. As measured by UV-Vis spectrophotometer at 488 nm, the resulting conjugate contained 19 molecules of FITC per unit of PSA, or 0.08 molecules of FITC per repeat unit of PSA. Cellular internalization ratio of PSA were studied by flow cytometry(FACS) and demonstrated that the cellular uptake was time dependent. The in vitro biocompatibility was examined by MTT method against 3T3 cell line and showed no notable effect on bioactivity of the cells. FITC labeled PSA was injected i.v. into normal nude mice. The optical imaging of dissected major organs/tissues revealed that preferential accumulation in specific organs was not observed at 24 h postinjection. The results suggest that PSA has characteristics of good biocompatibility, high efficiency of cellular uptake and modifiable surface function groups as well, which can serve as excellent platforms for a variety of therapeutic and imaging agents. It can be taken as an attractive drug/gene carrier system for intracellular delivery.

Key words: Poly(sulfone-amine), Cytotoxicity, Intracellular delivery, Biodistribution, Biocompatibility