Pluronic based injectable smart gels with coumarin functional amphiphilic copolymers

• Published in: European polymer journal 2022-08, Vol.177, p.111378, Article 111378
• Main Authors: Alemdar, Mahinur, Tuncaboylu, Deniz Ceylan, Batu, Hatice Kubra, Temel, Binnur Aydogan
• Format: Article
• Language: English
• Subjects: Addition polymerization; Amphiphilic copolymers; Aqueous solutions; Biomedical materials; Chain transfer; Copolymers; Coumarin; Crosslinking; Formulations; Fourier transforms; Hydrogels; Infrared analysis; Infrared spectroscopy; Injectability; Injectable gel; Liquid chromatography; Micelles; NMR spectroscopy; Photon correlation spectroscopy; Pluronic; Poloxamers; Polyethylene glycol; Polymerization; Polymers; Protons; Rheological properties; Rheology; Self-assembly; Smart gel; Terpolymers; Ultraviolet radiation
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2022.111378

[Display omitted] •RAFT polymerization of well-defined coumarin bearing amphiphilic copolymers.•Coumarin functionalized unique amphiphilic copolymers as repeating units on the chain.•Temperature responsive Pluronic F127 with light-responsive amphiphilic copolymers.•Designing mechanically strong injectable PF127 hydrogels. Temperature responsive Pluronic F127 micelles were combined with light-responsive coumarin bearing amphiphilic copolymers to obtain both mechanically strong and injectable gels. For this purpose two monomers, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CEMA) and 7-methacryloyloxy-4-methylcoumarin (CMA), were synthesized and further polymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Well-defined amphiphilic diblock terpolymers were obtained by using preliminarily synthesized polyethylene glycol (PEG) based macroRAFT agent. The structures of copolymers were confirmed with proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier-transform infrared(FT-IR) spectroscopy and gel permeation chromatography (GPC) analyses. Amphiphilic diblock terpolymers self-assembled into micelles in aqueous solution spontaneously and crosslinking of the micelle cores through the photodimerization of coumarin groups under UV irradiation at 350 nm was examined by UV spectroscopy. Hydrogels were prepared using two different methods, PF127-Mx gels formed using polymer micelle solutions with PF127 solid and PF127-Px gels formed by mixing solid polymers with 20 % F127 solution. Upon characterization of hydrogels via dynamic light scattering (DLS) and transition electron microscope (TEM), rheological properties of the gels were evaluated as a function of temperature, composition, UV exposure time, strain and frequency. Injectability tests of hydrogel systems were performed on a texture analyzer and all the formulations were found in the injectable range. The study reveals that hydrogels based on combination of PF127 and coumarin functional terpolymer amphiphiles hold great potential as injectable biomaterials.