Executive Summary : | Polymeric micelles have been extensively used for drug delivery systems of active pharmaceutical ingredient (API) with control manner [1, 2]. Various polymers can be synthesized for specific targeted applications. PNIPAM is chemically poly-n-isopropylacrylamide and is a biocompatible polymer that owns the dual pH and thermoresponsive property that makes it a promising candidate for targeted delivery of drugs in various cancer. The biocompatible nature of PNIPAM makes it promising candidate for drug delivery systems. It mimics the body temperature in terms of its lower critical solution temperature. PNIPAM can be fused with various other blocks and block copolymer that making it a multi responsive polymer. The fusing of ethylene oxide – propylene oxide (EO-PO) block copolymers (Pluronics® and Tetronics®) with PNIPAM gives a multi-block copolymer that comprises the dual property of both polymers. Targeting the applications of these penta block copolymers in advanced drug delivery, we have synthesized the penta block copolymer by blending US FDA approved Pluronics® F127 having PNIPAM at both ends by atomic transfer radical polymerization (ATRP) method (PNIPAM-F127-PNIPAM). Its temperature & pH-sensitivity and biocompatibility makes it promising candidate for various applications. PIs have also synthesized Poly(sodium 2-(acrylamido)-2-methylpropanesulfonate)-block-poly(N-isopropyl acrylamide) (PAMPS-b-PNIPAM) via reversible addition-fragmentation chain transfer (RAFT) controlled radical polymerization. The synthesized polymer vary in number of blocks (i) PAMPS61-b-PNIPAM11 (ii) PAMPS61-b-PNIPAM34, (iii) PAMPS148-b-PNIPAM26, (iv) PAMPS148-b-PNIPAM154. Such polymers can alter their morphology strongly depending upon external stimuli. At higher temperature PNIPAM forms core of micelles and at lower pH/in the presence of Fe+3 ions, PAMPS forms core. Such property can be employed for the fine tuning of aggregates having desire morphology. Similarly, number of polymer blocks with dissimilar multi responsive property (PBMA – butylmethacrylate, P4VP - poly(4-vinyl pyridine), PAA – polyacrylic acid, PMMA - Poly(methyl methacrylate), PA-b-PEG-b-PA - polyacrylate-b-poly(ethylene glycol)-b-poly acrylate, PDMPA - poly(N,N-dimethylaminopropylacrylamide, PBVIB - poly(butyl-3-vinylimidazolium bromide) can be blended with PNIPAM that opens up a broad window of applications for these kinds of polymers. All these polymer aggregates can be used for solubility enhancement of drugs and their controlled delivery, in biomedical applications requiring the control of protein adsorption. The intent of work is to establish a relation between the solution behaviour and morphology of aggregated formed under different microenvironment that can be further tuned to desire extent for drug delivery applications. This work will provide new routes for the administration of drugs by PNIPAM based block copolymers doped with hydrophobic drugs. |