Semi-interpenetrating network(semi-IPN) hydrogels composed of sodium carboxylmethyl cellulose(NaCMC) and poly N-isopropylacrylamide(PNIPAm) were prepared by free radical polymerization of N-isopropyl acrylamide(NIPAm) in dimethylsulfoxide(DMSO) in the presence of NaCMC. The structures of hydrogels were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM) and differential scanning calorimetry(DSC). SEM images show that the hydrogels present porous network structures. Most water in the hydrogels were free water and freezing water. The equilibrium swelling ratio(ESR) and swelling rate(SR) were quite different at various swelling temperature. ESR of the hydrogels ranged abruptly from 15.2 g/g to 1.56 g/g and the hydrogels changed from transparent into opaque with swelling temperature changing from 33 ℃ to 34 ℃, that is to say, the hydrogels exhibited the good temperature sensitivity at about 33 ℃ similar to low critical solution temperature(LCST) of pure PNIPAm, swelling rate were very different at below and above LCST due to hydrogel swelling with different swelling mechanism. Moreover, the semi-IPN hydrogels swelled much rapidly than pure PNIPAm hydrogels did at room temperature, the equillibrium swelling ratio(ESR) and swelling rate of the hydrogels increased with increasing of NaCMC content, i e. It is suggested that NaCMC could be potential for preparation of porous and rapid swelling hydrogels
Well-defined polymer micelles with core-shell structure are good delivery platform for stabilizing silver nanoparticles (AgNPs) in the field of antimicrobials targeting diseases. The rational construction of the polymer structure, an efficient, facile, and green preparation approach, and comprehensive exploration of the derived AgNPs are necessary, such as size, particle stability, antibacterial activity, and other properties. Herein, we designed and assessed the in vitro antimicrobial activity of AgNPs-decorated copolymer micelles with different copolymer topologies. First, linear or four-arm star triblock copolymers with the similar molecular weight and degree of polymerization were obtained, which consisted of DMAEMA for in situ reduction of silver ions to form AgNPs without external reducing agent. HEMA and PEGMA in micellar shell gave an enhanced stability of AgNPs during blood circulation. The combination of computational modeling and experimental results indicated that both types of micelles could fabricate AgNPs with monodisperse and spherical morphology. Star copolymer micelles stabilized AgNPs had smaller average size, better stability, and higher antibacterial activity than those with linear structure, which may due to higher stability of micelles from star copolymers. Furthermore, the cytotoxicity evaluation test showed that the achieved linear or star copolymers micelles stabilized AgNPs had good biocompatibility. This work provides a facile and universal approach in the rational design of micelles stabilized AgNPs with suitable topology for fighting against a wide range of bacterial infections.
Electronic supplementary material
The online version of this article (10.1186/s11671-019-3074-z) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.