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

<div><p>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 (<b>P1</b>) was used as an effective initiator for the ring opening polymerization of tetrahydrofuran (THF) in the presence of phthalic anhydride (PAH) as a comonomer (<b>P2</b>) 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 <b>P2</b> 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. <b>P1</b> and <b>P2</b> 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.</p></div