Search results for "pH-sensitive hydrogel"
showing 3 items of 3 documents
pH-sensitive hydrogel based on a polyaspartamide derivative
2006
A pH-sensitive hydrogel was prepared by UV irradiation technique. Starting polymer was obtained from alpha,beta-poly (N-2-hydroxyethyl)-DL-aspartamide (PHEA) partially derivatized with glycidyl methacrylate (PHG). The PHG copolymer was cross-linked by UV irradiation in the presence of methacrylic acid (MA) to form a pH sensitive hydrogel. The cross-linked matrix shaped as microparticles was characterized by FT-IR spectrophotometry, XPS, X-ray diffraction, SEM and particle size distribution analyses. Moreover, to have information about water affinity of the prepared sample, swelling measurements were carried out in aqueous media mimicking some biological fluids. In order to employ the prepar…
Drug release from α,β-poly(N-2-hydroxyethyl)-DL-aspartamide based microparticles
2004
Spherical pH-sensitive microparticles have been prepared by reverse phase suspension polymerization technique. Starting polymer has been alpha,beta-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) partially derivatized with glycidylmethacrylate (GMA). PHEAGMA copolymer (PHG) has been crosslinked in the presence of acrylic acid (AA) or methacrylic acid (MA) at various concentration. The obtained microparticles have been characterized by FT-IR spectrophotometry, particle size distribution analysis and scanning electron microscopy. In order to have information about water affinity of the prepared samples, swelling measurements have been carried out in aqueous media which simulate some biological f…
PHOTOCROSSLINKING OF DEXTRAN AND POLYASPARTAMIDE DERIVATIVES: A COMBINATION SUITABLE FOR COLON- SPECIFIC DRUG DELIVERY.
2007
The aim of this study was to prepare and characterize novel hydrogels with polysaccharide–polyaminoacid structure, able to undergo an enzymatic hydrolysis in the colon and potentially useful for treating inflammatory bowel diseases (IBD). Starting materials were methacrylated dextran (DEX-MA) and methacrylated α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHM). These polymers were photocrosslinked by exposure of their aqueous solutions at 313 nm without photoinitiators. Different samples, shaped as microparticles, were obtained as a function of polymer concentration and irradiation time. FT-IR analysis confirmed the occurrence of a co-crosslinking between DEX-MA and PHM in all experimental con…