Drug Design, Development and Therapy (Dec 2016)
Folic acid-conjugated amphiphilic alternating copolymer as a new active tumor targeting drug delivery platform
Abstract
Xia Li,1 Myron R Szewczuk,2 Cecile Malardier-Jugroot1 1Department of Chemistry and Chemical Engineering, Royal Military College of Canada, 2Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada Abstract: Targeted drug delivery using polymeric nanostructures is an emerging cancer research area, engineered for safer, more efficient, and effective use of chemotherapeutic drugs. A pH-responsive, active targeting delivery system was designed using folic acid functionalized amphiphilic alternating copolymer poly(styrene-alt-maleic anhydride) (FA-DABA-SMA) via a biodegradable linker 2,4-diaminobutyric acid (DABA). The polymeric template is pH responsive, forming amphiphilic nanostructures at pH 7, allowing the encapsulation of hydrophobic drugs on its interior. Moreover, the structure is stable only at neutral pH and collapses in the acidic tumor microenvironment, releasing drugs on-site from its core. The delivery vehicle is investigated using human pancreatic PANC-1 cancer cells and RAW-Blue™ mouse macrophage reporter cell line, both of which have overly expression of folic acid receptors. To trace the cellular uptake by both cell lines, curcumin was selected as a dye and drug mimic owing to its fluorescence nature and hydrophobic properties. Fluorescent microscopy of FA-DABA-SMA loaded with curcumin revealed a significant internalization of the dye by human pancreatic PANC-1 cancer cells compared to those with unfunctionalized polymers (SMA). Moreover, the FA-DABA-SMA polymers exhibit rodlike association specific to the cells. Both empty SMA and FA-DABA-SMA show little toxicity to PANC-1 cells as characterized by WST-1 cell proliferation assay. These results clearly indicate that FA-DABA-SMA polymers show potential as an active tumor targeting drug delivery system with the ability to internalize hydrophobic chemotherapeutics after they specifically attach to cancer cells. Keywords: functionalized copolymers, folic acid receptors, curcumin, enhanced hydrophobic drug delivery, improved cellular uptake
