Artykuł opisuje dwa rodzaje polimerów gwieździstych z ramionami z homopolimeru metakrylanu N,N-dimetyloaminoetylu (PDMAEMA) oraz z ramionami z kopolimeru bezładnego metakrylanu N,N-dimetyloaminoetylu i metakrylanu eteru monometylowego di(glikolu etylenowego) (PDMAEMA-co-PDEGMA), które syntezowano metodą „najpierw rdzeń”. Wyznaczając promienie hydrodynamiczne (Rh90°) badano zachowania otrzymanych polimerów w rozpuszczalnikach organicznych iw wodzie. Określano także wpływ pH i temperatury na potencjał zeta i nanocząstek tych polimerów w roztworach wodnych.
EN
This paper describes two kinds of star polymers with homopolymer arms made of N,N-dimethylaminoethyl methacrylate (PDMAEMA) and with random copolymer arms of N,N-dimethylaminoethyl methacrylate and di(ethylene glycol) methyl ether methacrylate (PDMAEMA-co-PDEGMA), which were synthesized via "core first” method. Hydrodynamic radii were determined and the behavior of obtained polymers in organic solvents and in aqueous solutions were studied. The effect of pH and temperature on the zeta potential and hydrodynamic radii of polymers particles were also investigated.
Thermosensitive chitosan hydrogels containing sodium beta-glycerophosphate (ß-GP), whose gelation is induced by increasing temperature to body temperature, were functionalized by incorporation of Alkaline Phosphatase (ALP), an enzyme involved in mineralization of bone. ALP incorporation led to acceleration of gelation upon increase of temperature for four different chitosan preparations of differing molecular weight, as demonstrated by rheometric time sweeps at 37°C. Hydrogels containing ALP were subsequently incubated in calcium glycerophosphate (Ca-GP) solution to induce their mineralization with calcium phosphate (CaP) in order to improve their suitability as materials for bone replacement. Incorporated ALP retained its bioactivity and induced formation of CaP mineral, as confirmed by SEM, FTIR, Raman spectroscopy, XRD, ICP-OES, and increases in dry mass percentage, which rose with increasing ALP concentration and incubation time in Ca-GP solution. The results demonstrate that ALP accelerates formation of thermosensitive chitosan/ß-GP hydrogels and induces their mineralization with CaP, which paves the way for applications as injectable bone replacement materials.
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