RESUMO

Thermosensitive macroporous scaffolds of poly(N-isopropylacrylamide) (polyNIPA) loaded with chitosan/bemiparin nanoparticles are prepared by the free radical polymerization in cryogenic conditions. Chitosan/bemiparin nanoparticles of 102 ± 6.5 nm diameter are prepared by complex coacervation and loaded into polyNIPA cryogels. SEM image reveal the highly porous structure of cryogels and the integration of nanoparticles into the macroporous system. Volume phase transition temperature (VPT) and total freezing water content of cryogels are established by differential scanning calorimetry, and their porosity is determined by image-NMR. Swelling of cryogels (above and below the VPT) is highly dependent on nanoparticles concentration. In vitro release profile of bemiparin from cryogel is highly modulated by the presence of chitosan. Bemiparin released from nanoparticles preserves its biological activity, as shown by the BaF32 cell proliferation assay. Cryogels are not cytotoxic for the human fibroblast cells and present excellent properties for application on tissue engineering and controlled release of heparin.

Assuntos

Resinas Acrílicas/química , Quitosana/química , Criogéis , Preparações de Ação Retardada/química , Heparina de Baixo Peso Molecular/química , Nanopartículas/química , Resinas Acrílicas/farmacologia , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Materiais Biocompatíveis , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Preparações de Ação Retardada/farmacologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Heparina de Baixo Peso Molecular/farmacologia , Humanos , Cinética , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Polimerização , Porosidade , Temperatura , Engenharia Tecidual , Alicerces Teciduais