title: Polymeric nanostructures with pH-labile core for controlled drug release.
abstract: Efficient and stimuli-triggered controlled delivery of therapeutics is one of the important issues in modern advanced therapy. In the present work, a versatile route for the synthesis of core cross-linked polymeric nanostructures (CLPN) through thiol-acrylate Michael addition reaction via the formation of β-thiopropionate has been described. The acid groups of the poly(acrylic acid) block of poly(ethylene glycol)-b-poly(N-isopropylacrylamide)-b-poly(acrylic acid) triblock copolymer were reacted with 2-hydroxyethyl acrylate (HEA) to yield the corresponding acrylate-functionalized copolymer (P1). Following this, P1 was reacted with a thiol functionalized cross-linker (CL) resulting in the formation of core cross-linked polymeric nanoparticles through acrylate-thiol Michael reaction. The ability of these nanoparticles to encapsulate drug molecules inside their core and their effective release following a pH-triggered controlled degradation of the core were demonstrated. The temperature sensitive release behaviour of the system was also studied. The non-toxic nature of the precursor polymers and the core cross-linked polymeric nanoparticles was also established, that further substantiated their potential as carriers for controlled release of drugs.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Banerjee
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
authors.forename: Saikat
authors.initials: S
authors.lastname: Maiti
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Dey
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India. Electronic address: dibakar@chem.iitkgp.ernet.in.
authors.forename: Dibakar
authors.initials: D
authors.lastname: Dhara
mesh_terms: D000179:Acrylates / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry*; D065546:Drug Liberation; D006863:Hydrogen-Ion Concentration; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D000179:Acrylates; D000180:Acrylic Resins; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; C035957:2-hydroxyethyl acrylate; D011092:Polyethylene Glycols; C006903:carbopol 940
keywords: Block copolymers; Polymer colloids; Prednisolone; RAFT polymers; Thermosensitive release; Thiol–acrylate Michael addition; pH-triggered degradation