RESUMO
Gd-based complexes are widely used as magnetic resonance imaging (MRI) contrast agents. The safety of previously approved contrast agents is questionable and is being re-assessed. The main causes of concern are possible gadolinium deposition in the brain and the development of systemic nephrogenic fibrosis after repeated use of MRI contrasts. Thus, there is an urgent need to develop a new generation of MRI contrasts that are safe and that have high selectivity in tissue accumulation with improved local contrast. Here, we report on a new type of theranostic MRI contrast, namely dextran stabilised, gadolinium doped cerium dioxide nanoparticles. These ultra-small (4-6 nm) Ce0.9Gd0.1O1.95 nanoparticles have been shown to possess excellent colloidal stability and high r1-relaxivity (3.6 mM-1 s-1). They are effectively internalised by human normal and cancer cells and demonstrate dose-dependent selective cytotoxicity to cancer cells.
Assuntos
Antioxidantes/farmacologia , Materiais Biocompatíveis/farmacologia , Meios de Contraste/farmacologia , Imageamento por Ressonância Magnética , Nanopartículas/química , Antioxidantes/síntese química , Antioxidantes/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cério/química , Cério/farmacologia , Meios de Contraste/síntese química , Meios de Contraste/química , Dextranos/química , Dextranos/farmacologia , Relação Dose-Resposta a Droga , Gadolínio/química , Gadolínio/farmacologia , Humanos , Teste de Materiais , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismoRESUMO
Experimental studies of composite materials formed on the basis of fluorine-containing latex and bioactive polysaccharides showed that physicochemical properties of composite materials and their adhesion characteristics can be modulated by variations of polysaccharide-latex ratio and the nature of polysaccharides. The ratio of components ensuring the formation of biosynthetic films that meet the standards for modern wound coating and maintain adhesion and growth of substrate-dependent mammalian cells was determined. These materials can considerably increase the efficiency of treatment of extensive and deep skin wounds in cases when application of cell cultures is indicated.
Assuntos
Bandagens , Materiais Biocompatíveis/química , Técnicas de Cultura de Células/métodos , Ferimentos e Lesões , Adesão Celular , Humanos , Látex/química , Teste de Materiais , Metilcelulose/química , Polissacarídeos/químicaRESUMO
We propose a method of creation of a 3D matrix consisting of native collagen fibers and natural polysaccharide chitosan. The collagen-chitosan hydrogels maintain viability and prolipherative activity of embryonic stem cells obtained from internal cells of mouse blastocyst. The proposed system forming hydrogels in situ can be used in cell therapy for immobilization and targeted delivery of stem cells.
