Synthesis, Characterization, Drug Delivery, and Splinting Activity of Folic Acid Bridged Poly(ɛ-caprolactone-co-tetrahydrofuran)

Synthesis of a material for drug delivery application is a fascinating field of research. Folic acid (FA) is an anticancer drug and is used as an initiator for the ring opening polymerization of ϵ-caprolactone (CL) at 160°C for 2 h under N2 atmosphere. The FA end-capped PCL (P1) was used as an effective initiator for the ring opening polymerization of tetrahydrofuran (THF) in the presence of phthalic anhydride (PAH) as a comonomer (P2) at 45°C for 48 h under inert atmospheric condition with mild stirring. The obtained polymers were characterized by FTIR, NMR, DSC, TGA, FESEM, GPC, SEM, UV-visible spectrometry, and EDAX. Appearance of a peak at 1595 cm−1 confirmed the formation of copolymer through tetrahydrofuronium ion. The copolymer structure can be confirmed by noting a peak at 7.6 ppm in the 1H-NMR spectrum. The increase in weight average molecular weight of P2 confirmed the copolymer formation. The previously synthesized polymer was tested toward the splitting application and further confirmed by determining the tensile strength. The drug delivery study was also conducted. P1 and P2 exhibited the Hixson-Crowell and Higuchi model drug release mechanisms, respectively. The water contact angle measurement also confirmed the conversion of hydrophobic in to hydrophilic during the copolymer formation.