Grafted Microparticles Based on Glycidyl Methacrylate, Hydroxyethyl Methacrylate and Sodium Hyaluronate: Synthesis, Characterization, Adsorption and Release Studies of Metronidazole

Abstract

Three types of precursor microparticles based on glycidyl methacrylate, hydroxyethyl methacrylate and one of the following three crosslinking agents (mono-, di- or triethylene glycol dimethacrylate) were prepared using the suspension polymerization technique. The precursor microparticles were subsequently used to obtain three types of hybrid microparticles. Their synthesis took place by grafting sodium hyaluronate, in a basic medium, to the epoxy groups located on the surface of the precursor microparticles. Both types of the microparticles were characterized by: FTIR spectroscopy, epoxy groups content, thermogravimetric analysis, dimensional analysis, grafting degree of sodium hyaluronate, SEM and AFM analyses, and specific parameters of porous structures (specific surface area, pore volume, porosity). The results showed that the hybrid microparticles present higher specific surface areas, higher swelling capacities as well as higher adsorption capacities of antimicrobial drugs (metronidazole). To examine the interactions between metronidazole and the precursor/hybrid microparticles the adsorption equilibrium, kinetic and thermodynamic studies were carried out. Thus, it was determined the performance of the polymer systems in order to select a polymer–drug system with a high efficiency. The release kinetics reflect that the release mechanism of metronidazole in the case of hybrid microparticles is a complex mechanism characteristic of anomalous or non-Fickian diffusion.

Synthesis of Crosslinked Microparticles Based on Glycidyl Methacrylate and N‐Vinylimidazole

“…Also, the zwitterionic polymers, especially polybetaines can be considered smart materials due to their response to pH changes as follows: in acid medium the polybetaines are transformed in the corresponding polyelectrolytes and in presence of water they return to the zwitterion form. hybrid materials can be obtained by grafting reactions of polysaccharides at epoxy rings in basic medium, as shown in our previous work. [ 17,19,20 ] quaternary ammonium compounds with antimicrobial activity can be prepared by quaternization of the 3 position of NVI;…”

“…• hybrid materials can be obtained by grafting reactions of polysaccharides at epoxy rings in basic medium, as shown in our previous work. [17,19,20] • quaternary ammonium compounds with antimicrobial activity can be prepared by quaternization of the 3 position of NVI;…”

“…[15] A variety of polysaccharides (xanthan, gellan, chitosan, and sodium hyaluronan) can be grafted by a slightly modified suspension polymerization onto porous microparticles based on GMA and various dimethacrylic monomers as well as onto porous crosslinked microparticles based on GMA and hydroxyethyl methacrylate in order to obtain the macromolecular carriers for drug delivery systems. [16][17][18][19][20] Also, N-vinylimidazole (NVI) is a vinyl monomer that can participate in radical polymerization reactions and generate polymeric materials that may present biocompatibility, biodegradability, and antibacterial activity. This vinyl monomer was previously used in enzyme immobilization, [21] water treatment, [22,23] catalysis, [24] and drug delivery systems.…”

Hydrogels in Biomedicine: Granular Controlled Release Systems Based on 2-Hydroxyethyl Methacrylate Copolymers. A Review

“…Three series of porous microparticles based on glycidyl methacrylate, HEMA, and one of the following crosslinking agents: mono-, di-, or triethylene glycol methacrylate, were obtained by polymerization in water suspension 74 . By the reaction of grafting sodium hyaluro-nate to the existing epoxy groups on the surface of the microparticles, hybrid porous microparticles were obtained, which have a larger specific surface area, better swelling ability, and higher adsorption capacity for antimicrobial drugs (metronidazole) compared to the unmodified polymer.…”