Thermoresponsive and Photocrosslinkable PEGMEMA-PPGMA-EGDMA Copolymers from a One-Step ATRP Synthesis

Abstract

Thermoresponsive and photocrosslinkable polymers can be used as injectable scaffolds in tissue engineering to yield gels in situ with enhanced mechanical properties and stability. They allow easy handling and hold their shapes prior to photopolymerization for clinical practice. Here we report a novel copolymer with both thermoresponsive and photocrosslinkable properties via a facile one-step deactivation enhanced atom transfer radical polymerization (ATRP) using poly(ethylene glycol) methyl ether methylacrylate (PEGMEMA, M(n) = 475) and poly(propylene glycol) methacrylate (PPGMA, M(n) = 375) as monofunctional vinyl monomers and up to 30% of ethylene glycol dimethacrylate (EGDMA) as multifunctional vinyl monomer. The resultant PEGMEMA-PPGMA-EGDMA copolymers have been characterized by gel permeation chromatography (GPC) and 1H NMR analysis, which demonstrate their multivinyl functionality and hyperbranched structures. These water-soluble copolymers show lower critical solution temperature (LCST) behavior at 32 degrees C, which is comparable to poly(N-isopropylacrylamide) (PNIPAM). The copolymers can also be cross-linked by photopolymerization through their multivinyl functional groups. Rheological studies clearly demonstrate that the photocrosslinked gels formed at a temperature above the LCST have higher storage moduli than those prepared at a temperature below the LCST. Moreover, the cross-linking density of the gels can be tuned to tailor their porous structures and mechanical properties by adjusting the composition and concentration of the copolymers. Hydrogels with a broad range of storage moduli from 10 to 400 kPa have been produced.

Synthesis and aggregation properties in water solution of comblike methacrylic polymers with oligo(propylene glycol)‐block‐oligo(ethylene glycol) as side chains

“…As a result, they can be used as surfactants, cosmetics, as carrier for most routes of administration and in tissue engineering applications. 9,10 In the last years, another amphiphilic polymeric family based on a nonlinear analog of PEG, such as poly[oligo(ethylene glycol) methacrylate] [P(OEGMA)], has aroused a great deal of attention. [11][12][13][14][15][16][17][18][19][20][21][22][23] These polymers present the good properties of PEG and, in addition, they can be obtained by controlled/living radical polymerization techniques, such as atom transfer radical polymerization (ATRP).…”

“…However, the controlled copolymerization of both monomers OEGMA and OPGMA has been carried out, leading to polymers with interesting properties and applicability in the delivery of drugs and cells. 9,10,26 Taking all these facts into account, in this work is explored a novel route to prepare new well-controlled amphiphilic block methacrylic copolymers based on oligo(ethylene glycol) (OEG) and OPGMA. In a first step, P(OPGMA) with different molecular weights was obtained by the ATRP of OPGMA macromonomer end capped with a hydroxyl group.…”

Sol–gel transition of novel temperature responsive ABA triblock copolymer P(MEO2MA-co-HMAM)-b-PEG-b-P(MEO2MA-co- HMAM)

“…Their some properties can change in response to a variety of external stimuli such as temperature, pH, light, ionic strength, and electric and magnetic fields [1][2][3][4][5][6][7]. Temperature sensitivity is one of the most interesting properties in stimuli-responsive polymers.…”

“…Temperature-responsive copolymers have been greatly studied and widely used. Below the LCST, the copolymer is water soluble, and above the LCST it becomes insoluble [1,3,6,7].…”

Photocrosslinkable Polymers for Biomedical Applications

“…hyaluronic acid) or from synthetic monomers in the presence of a photoinitiator, using visible or ultraviolet light (Nguyen & West, 2002). Tai et al (2009) prepared and characterized photocrosslinked hydrogels from synthetic monomers to be used as advanced injectable biomaterials. They observed that the PEGMEMA-PPGMA-EGDMA copolymers, with both thermoresponsive and photocrosslinkable properties, have excellent mechanical properties above the LCST.…”