Folic Acid Conjugated Polymer as a New Active Tumor Targeting Drug Delivery Platform X. Li * , M.R. Szewczuk ** and C. Malardier-Jugroot *** * Royal Military College of Canada, Kigston, ON, Canada, xia.li@rmc.ca ** Queen’s University, Kingston, ON, Canada, szewczuk@queensu.ca ***Royal Military College of Canada, Kigston, ON, Canada, cecile.malardier-jugroot@rmc.ca ABSTRACT The molecular modelling characterization and synthesis of the folate functionalized biomaterial poly(styrene-alt-maleic anhydride), PSMA predicted the folic acid functionalized SMA as a good candidate for targeted drug delivery. Folate was attached to the pH responsive SMA polymer via a biodegradable linker 2,4- diaminobutyric acid, DABA. The computational results predicted DABA as the optimal linker and showed that the functionazlied PSMA is linear at neutral condition and its linearity remains pH responsive. However, the earlier synthesis route displayed difficulties in characterization and purification due to the complexity of polymeric products. In this paper, a different synthesis route is shown along with NMR and IR characterization. We will show some preliminary results of applying biomaterials in cell lines. Curcumin, a natural ingredient was selected as a fluorecent marker to study polymer-cell binding efficiency as well as cellular uptake. The WST assy results confirmed that both SMA and FA-DABA-SMA polymer templates are not toxic to the cells and the delivrying vehicles proved to be effective in releasing hydrophobic anti-tumor drugs into the tumor cells. Keywords: folate receptor, drug delivery, pH-responsive, amphiphilic co-polymers, curcumin 1 INTRODUCTION Drug delivery systems capable of unloading drugs in response to pH changes have received much attention in recent years. Poly(styrene-alt-maleic anhydride), PSMA, is an amphiphilic alternating copolymer that self-assembles into nanotubes in aqueous solution, physiological-pH environments i . Its self-assembled structure with a 2nm hydrophobic inner diameter is stable in neutral pH solution, but collapses when pH is increased or decreased. These unique features of PSMA make it a great candidate for controlled release drug delivery vehicle for cancer cells for which the pH is significantly lowered compared to primary cells. PSMA has been considered as drug delivery vesicle as early as 1980s by Maeda and coworkers 2 . Its been shown that PSMA has low toxicity in cells and binds to albumin and therefore has an increased circulation time in blood stream 3–5 . To increase the specificity of the drug delivery vessel, folic acid is attached. The folic acid has extermely high affinity (K D ~10M) towards its receptors which are over- expressed in certain types of cancers ii . Indeed, the folate- conjugated nanotubes could potentially transport small, highly toxic, hydrophobic chemotherapy agents safely through the body to be released selectively inside target cells. Once the drug is unloaded, the biocompatible SMA, folate, and linker groups would clear through the excretory system. The synthesis was conducted in our lab using DCC/NHS coupling reagents linking carbolylic acids with amines. Amide bonds were therefore made among SMA, linker and folic acid. Previously we reported a synthesis route where polymer SMA was the starting material, linker and folic acid were added subsequently. However, due to the complexity of characterizing polymeric compounds, the second method starts with folic acid and linker and SMA polymer were attached in order. All structures were purified in each step and characterized using IR and NMR techniques. The polymers were labelled using curcumin, which is the active ingredient in tumeric. Curcumin is an effective and safe anticancer agent, however its hydrophobicity inhibits its clinical application 9,10 . Nanotechnology provides an effective method to improve the water solubility of hydrophobic drug. In this research, curcumin is incorporated to the hydrophobic interior of polymeric biomaterial by diffusion as a drug mimic and its fluorecent property serves as a biomarker. Human pancreatic cancer cell lines PANC-1 was culcutred in the lab and the polymer-cell binding efficiency and cellular uptake activities were analysed by fluorecent microscopy. The uptake of curcumin in pancreatic PANC1 cancer and RAW-blue macrophage cell lines was studied using fluorescent microscopy. The cell viability using FA- DABA-SMA and curcumin encapsulated FA-DABA-SMA was be studied using the cell proliferation WST-1 assay. The results from this study show potential of using FA- DABA-SMA as targeted hydrophobic drug delivery vehicle. 2 METHODS 2.1 Materials 13% poly(styrene-alt-maleic anhydride) (Mw=350,000) was purchased from Sigma Aldrich and freeze dried into white powder. Boc-2,4-diaminobutyric acid (DABA), N- hydroxy-succimide (NHS), dicyclohexylcarbodiimide Biotech, Biomaterials and Biomedical: TechConnect Briefs 2016 61