Convenient Access to Biocompatible Block Copolymers from SG1-Based Aliphatic Polyester Macro-Alkoxyamines

Abstract

SG1-based poly(d,l-lactide) (PLA) or poly(epsilon-caprolactone) (PCL) macro-alkoxyamines were synthesized and further used as macroinitiators for nitroxide-mediated polymerization (NMP) of 2-hydroxyethyl (meth)acrylate (HE(M)A) to obtain the corresponding PLA- or PCL-PHE(M)A block copolymers. First, a PLA-SG1 macro-alkoxyamine was prepared by 1,2-intermolecular radical addition (IRA) of the MAMA-SG1 (BlocBuilder) alkoxyamine onto acrylate end-capped PLA previously prepared by ring-opening polymerization. The NMP of HEA monomer from the PLA-SG1 macro-alkoxyamine appeared to be well controlled in the presence of free SG1 nitroxide, contrary to that of HEMA. In the latter case, adjustable molecular weights could be obtained by varying the HEMA to macro-alkoxyamine ratio. The versatility of our approach was then further applied to the preparation of PHEMA-b-PCL-b-PHEMA copolymers from a alpha,omega-di-SG1 functionalized PCL macro-alkoxyamine previously obtained from a PCL diacrylate by IRA. Preliminary studies of neuroblast cultures on these PCL-based copolymer films showed acceptable cyto-compatibility, demonstrating their potential for nerve repair applications.

Recent advances in synthetic polymer based hydrogels for spinal cord repair

“…We opted for a block copolymer design, as a physical blending of the two incompatible homopolymers would only result in a non-valid biomaterial displaying a macrophase separation. Our synthesis approach, based on a previous work realized in our laboratory [72,73], relied on the use of a PLA-SG1 (N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl)aminoxyl) macroalkoxyamine. Such a molecule is able to initiate polymerization of HEMA (Scheme 1) through nitroxide-mediated polymerization (NMP), which is usually used as a controlled/living radical polymerization technique [74,75].…”

Construction of paclitaxel-loaded poly (2-hydroxyethyl methacrylate)-g-poly (lactide)- 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine copolymer nanoparticle delivery system and evaluation of its anticancer activity

“…All these results confirm that the PHEMA derivatives contained a PLA side chain. 14,15 In the 1 H NMR spectra of the PHEMA-g-(PLA-DPPE) copolymer ( Figure 2C), the signal at about 0.9 ppm was attributed to the terminal methyl proton of the DPPE moiety. Peaks at 1.2-1.6 ppm were attributed to methyl protons of the DPPE moiety.…”

“…[5][6][7][8][9] However, the mechanical properties of PHEMA hydrogels do not fit the requirements for many structural applications. Therefore, amphiphilic polymers consisting of PHEMA and biodegradable polyesters, ie, poly(L-lactide) (PLLA), 10,11 poly(D,L-lactide), [12][13][14] poly(glycolic acid), poly(ε-caprolactone), 15,16 and polystyrene, have been synthesized. 17 These copolymers can be obtained through ring-opening polymerization, atom transfer radical polymerization, 11,18,19 A 2 B 2 PCl/acrylate miktoarm polymers, 20 or use of a protective group, eg, a trimethylsilyl moiety.…”

Nitroxide‐Mediated Polymerization of 2‐Hydroxyethyl Methacrylate (HEMA) Controlled with Low Concentrations of Acrylonitrile and Styrene

“…Bian et al reported the controlled polymerization of the related 2‐hydroxyethyl acrylate by NMP using MONAMS initiator with SG1 in bulk and in N , N ‐dimethylformamide (DMF) solution . Clément et al reported the homopolymerization of HEMA using a SG1‐based aliphatic polyester macroalkoxyamines . Not surprisingly, the homopolymerization was not controlled, with no chain extension observed.…”