Rapid and efficient side‐chain functionalization of polypeptide with neighboring carboxylgroups is achieved via the combination of ring‐opening polymerization and subsequent thiol‐yne click chemistry. The spontaneous formation of polymersomes with uniform size is found to occur in aqueous medium via electrostatic interaction between the anionic polypeptide and cationic doxorubicin hydrochloride (DOX·HCl). The polymersomes are taken up by A549 cells via endocytosis, with a slightly lower cytotoxicity compared with free DOX ·HCl. Moreover, the drug‐loaded polymersomes exhibit the enhanced therapeutic efficacy, increase apoptosis in tumor tissues, and reduce systemic toxicity in nude mice bearing A549 lung cancer xenograft, in comparison with free DOX ·HCl. 相似文献
We report on a facile immunoassay for porcine circovirus type 2 (PCV2) based on surface enhanced Raman scattering (SERS) using multi-branched gold nanoparticles (mb-AuNPs) as substrates. The mb-AuNPs in the immunosensor act as Raman reporters and were prepared via Tris base-induced reduction and subsequent reaction with p-mercaptobenzoic acid (pMBA). They possess good stability and high SERS activity. Subsequently, the modified mb-AuNPs were covalently conjugated to the monoclonal antibody (McAb) against the PCV2 cap protein to form SERS immuno nanoprobes. These were captured in a microtiterplate via a immunoreaction in the presence of target antigens. The effects of antibody concentration, reaction time and temperature on the sensitivity of the immunoassay were investigated. Under optimized assay conditions, the Raman signal intensity at 1,076 cm?1 increases logarithmically with the concentrations of PCV2 in the concentration ranging from 8?×?102 to 8?×?106 copies per mL. The limit of detection is 8?×?102 copies per mL. Compared to conventional detecting methods such as those based on PCR, the method presented here is rapid, facile and very sensitive.
Figure
A simple and novel approach to detect porcine circovirus type 2 using surface enhanced Raman scattering (SERS) of multi-branched gold nanoparticles is demonstrated, it has a higher sensitivity than polymerase chain reaction and ELISA. 相似文献
Atom transfer radical polymerization (ATRP) is a versatile and robust tool to synthesize a wide spectrum of monomers with various designable structures. However, it usually needs large amounts of transition metal as the catalyst to mediate the equilibrium between the dormant and propagating species. Unfortunately, the catalyst residue may contaminate or color the resultant polymers, which limits its application, especially in biomedical and electronic materials. How to efficiently and economically remove or reduce the catalyst residue from its products is a challenging and encouraging task. Herein, recent advances in catalyst separation and recycling are highlighted with a focus on (1) highly active ppm level transition metal or metal free catalyzed ATRP; (2) post‐purification method; (3) various soluble, insoluble, immobilized/soluble, and reversible supported catalyst systems; and (4) liquid‐liquid biphasic catalyzed systems, especially thermo‐regulated catalysis systems.
