The negatively charged, water-soluble, hydrophobically modified poly(sodium glutamate)s, containing different amounts of alkyl grafts, were synthesized. First, poly(γ-benzyl-L-glutamate) was prepared by ring-opening polymerization of the corresponding N-carboxyanhydride, which was in the next step aminolyzed with octylamine. After removal of the remaining benzyl protective groups, the alkyl-modified poly(sodium glutamate)s [P(Glu-oa)] were obtained and, together with the oppositely charged N,N,N-trimethyl chitosan (TMC), used for the preparation of nanoparticles of a recombinant granulocyte colony-stimulating factor (GCSF) protein by polyelectrolyte complexation method. It was observed that, beside electrostatic interaction, the hydrophobic grafts on poly(sodium glutamate)s significantly contribute to the association efficiency with GCSF protein. The addition of TMC solution to the dispersion of GCSF/P(Glu-oa) complexes resulted in formation of much more defined nanoparticles with high association efficiency and final protein loading.
COBISS.SI-ID: 5530906
Water-soluble, biodegradable, and biocompatible poly(ester-amide) dendrimers with hydroxyl functional groups were synthesized from previously prepared AB2 adduct of 2,2-bis(hydroxymethyl)propanoic acid (bisMPA) and glycine as a repeating unit. Two esterification procedures using different coupling reagent/catalyst systems (DCC/DPTS or EDC/DMAP) were studied with respect to their efficiency, ease of products purification, and quality of the final products. Both procedures have their own benefits and drawbacks, depending on the dendrimer generation. The synthesized poly(ester-amide) dendrimers, as well as commercially available bis-MPA dendrimers, poly(ester-amide) hyperbranched polymers, and poly(vinyl alcohol), were used for the preparation of solid dispersions of sulfonylurea antidiabetic drug glimepiride to improve its poor water-solubility. In-vitro dissolution studies show in comparison with pure glimepiride in crystalline or amorphous form, to the same extent improved glimepiride solubility for solid dispersions based on dendritic polymers, but not for the poly(vinyl alcohol). The amount of glimepiride complexed with both dendrimer types increases with the dendrimer generation.
COBISS.SI-ID: 5548826
Highly porous hydrogels based on functionalized glycidyl methacrylate (GMA) have been succesfully prepared through the high internal phase oil-in-water emulsions. Pre-polymerization functionalization of GMA monomer, porous structure and water uptake of highly porous hydrogels were investigated. The primary amine groups of tris(2-aminoethyl)amine (TRIS) or 1,2-diaminoethane (EDA) were found to react in three distinct reactions with the GMA, giving a mixture of methacrylate and methaycrylamide as the major prodcuts with a small amount of the aza-Michael addition product, which were then polymerized. The water uptake and the specific surface area were found to be between 4-5 times higher than the corresponding values for the conventional GMA-based polyHIPEs prepared from the water-in-oil HIPEs. These results demonstrate a highly efficient pre-polymerization functionalization method for the preparation of GMA-based hydrogel polyHIPEs.
COBISS.SI-ID: 5948698
High internal phase emulsions of water in cyclooctene stabilized by sorbitan monooleate (Span 80) were cured by ring-opening metathesis polymerization to release the fully open macroporous polymer foams wherein the surfactant was covalently incorporated into the poly(cyclooctene) strands via the chain transfer reactions. We have thus developed a new method for surface functionalization of highly porous polymer networks.
COBISS.SI-ID: 37876997
In this manuscript we have designed a synthetic approach for the preparation of a series of chitosan-graft-poly(L-glutamate) copolymers with different lengths of poly(L-glutamate) grafts. First, organosulfonic chitosan salt, soluble inDMSO,was prepared in order to effectively initiate ring-opening polymerization of c-benzyl-L-glutamate N-carboxyanhydride. The chitosan-graft-poly(c-benzyl-L-glutamate) copolymers were fully deprotected by applying tetrabutylammonium hydroxide. Themolarmass characteristics and chemical composition of graft copolymers with various lengths of polypeptide graftswere determined by SEC-MALS, FTIR and various NMR spectroscopic techniques. The synthesized chitosan-graft-poly(sodium-L-glutamate) copolymers were used in combination with trimethyl chitosan for the preparation of nanoparticles (NPs) of a recombinant granulocyte colony-stimulating factor (GCSF). The suspensions of NPs with typical average diameter of 200–300 nm were obtained with polydispersity index values below 0.26. The achieved loading efficiencywas up to 95 %and the final loading ofGCSF protein in NPs was up to 45 %. The time, temperature and pH stability of NPs was also studied.
COBISS.SI-ID: 5522714