RESUMO
Immobilizing enzymes into microcarriers is a strategy to improve their long-term stability and reusability, hindered by (UV) light irradiation. However, in such approaches, enzyme-substrate interaction is mediated by diffusion, often at slow kinetics. In contrast, enzyme-linked self-propelled motors can accelerate this interaction, frequently mediated by the convection mechanism. This work reports on a new photosensitive polymeric Janus micromotor (JM) for UV-light protection of enzymatic activity and efficient degradation of substrates accelerated by the JMs. The JMs were assembled with UV-photosensitive modified chitosan, co-encapsulating fluorescent-labeled proteins and enzymes as models and magnetite and platinum nanoparticles for magnetic and catalytic motion. The JMs absorbed UV light, protecting the enzymatic activity and accelerating the enzyme-substrate degradation by magnetic/catalytic motion. Immobilizing proteins in photosensitive JMs is a promising strategy to improve the enzyme's stability and hasten the kinetics of substrate degradation, thereby enhancing the enzymatic process's efficiency.
Assuntos
Quitosana/química , Enzimas Imobilizadas/química , Nanopartículas de Magnetita/química , Movimento (Física) , Armoracia/enzimologia , Compostos Azo/química , Compostos Azo/efeitos da radiação , Catalase/química , Quitosana/efeitos da radiação , Peroxidase do Rábano Silvestre/química , Peróxido de Hidrogênio/química , Lacase/química , Fenômenos Magnéticos , Nanopartículas de Magnetita/efeitos da radiação , Platina/química , Platina/efeitos da radiação , Raios UltravioletaRESUMO
This work presents the preparation of radiolabelled cis-dichlorodiammineplatinum (II), CDDP*, sealed in a cadmium capsule. The irradiation of CDDP covered by cadmium, employing exposure times longer than 2 h, demonstrated good chemical purity and high specific activity. This finding allowed a better detection of in vivo CDDP* and suggests that it may be a good tool for studies of long-term biodistribution of pharmaceutical formulations containing this drug.