Purpose:
Previously, we have presented reversible poly(acrylamide) based in situ forming polymeric hydrogels as vitreous substitutes. In this study we present the synthesis and biocompatibility testing of four poly(methacrylamide) derivatives with which we can employ our reversible gelling technology.
Methods:
Briefly, an activated precursor was prepared using atom transfer radical polymerization (ATRP) of the prepared monomer N-methacryloxysuccinimide (MOSu). This gave poly(N-methacryloxysuccinimide) (PMOSu). Four primary amine-containing chemicals, ethanolamine, 2-(2-(aminoethoxy)ethanol, 2-[2-(2-aminoethoxy)ethoxy]ethanol and 2-[(2-aminoethoxyhydroxyphosphinyl)oxy]-N,N,N,-trimethylethanaminium hydroxide were reacted with the succinimide group to give derivatives of poly(methacrylamide) (see figure). The cytotoxicity of these four derivatives was evaluated byin vitro testing using retinal pigment epithelial cells. By adding a crosslinker containing a disulfide bond, polymeric hydrogels will be prepared from this derivative and re-gelled in situ.
Results:
The obtained polymer PMOSu had a narrow molecular weight distribution. After hydrolysis with sodium hydroxide, the molecular weight of poly(methacrylic acid sodium salt) was 47.1 kDa by GPC, corresponding to a molecular weight of PMOSu of 80.2 kDa. The structures of four derivatives of poly(methacrylamide) were confirmed by 1H NMR.
Conclusions:
Poly(hydroxypropyl methacrylamide) has already been established as having good biocompatibility and is being investigated for a number of biological purposes. We have synthesized related polymers and can effectively apply our technologies to use these polymers for vitreous substitutes.
Keywords: vitreous substitutes • vitreous • vitreoretinal surgery