Preparation And Characterization Of Nanocomposite Drug Loaded Micelles

In this paper, a series of P(NIPAAm-co-NVP) microgels with controllable diameter andLower Critical Solution Temperature(LCST) were synthesized, using N-isopropylacrylamide(NIPAAm) and N-Vinylpyrrolidone (NVP) as monomers, N, N-methylenebisacrylamide (BIS)and Liponite as crosslinking agents respectively, in which graphene oxide (GO) nanosheetswere introduced. The copper sulfide (CuS) nano-particles which have the photothermal effectwere prepared by wet-chemical method. The polymer gel/copper sulfide (NNC/CuS)nanocomposite microspheres were prepared by the method of nano-copper sulfide is generatedinternally in situ in the gel microspheres. The nano-CuS and the composite microspheres werestudied by a near-infrared light (980nm) for photothermal effect. And then preliminarystudied the killing effect of these two materials in vitro tumor cells.The experimental results showed that: the sizes of the microgels could be controlled byvarying the monomer rate and the content of the crosslinking agents, controlling thecomonomers rate could adjust the Lower Critical Solution Temperature (LCST). With theincrease of the content of the copolymerizable monomer NVP, the gel microsphere sizegradually increases, the volume phase transition temperature was gradually increased, thephase transition temperature range was increasingly wide and the volume phase transitionphenomenon was no obvious; When the NIPAAm/NVP molar ratio was8:2, the LCST of thePNIPAAm microspheres was32°C up to40°C (higher than the human body temperature);The amount of crosslinking agent did not affect the LCST of the microgel, but the gelmicrospheres average particle diameter increased with BIS dosage increasing and decreasedwith increasing clay content; The introduction of clay and graphene sheets can improved thedrug loading of the microspheres, and the effect of the graphene sheets were more obvious;When the environmental temperature was higher than the microgel LCST, the drug release rateand total significantly fast and increase; the model drug doxorubicin hydrochloride (DOX)release rate in the pH=5.5release environment was significantly greater than the pH=7.4;Nanocrystalline CuS and composite microspheres had a very wide spectral absorption band inthe near infrared region, and in the980nm laser irradiation case, the temperature of thecolloidal solution can be changed from20to40°C; When the concentration of CuSnanoparticles less than1mM, CuS showed non-toxic or low toxicity on A549cells and good non-toxic on HeLa cells; When the NNC/CuS composite microspheres concentration less than0.43mg/mL, the composite microspheres showed non-toxic on A549cells, but when theconcentration reached1.30mg/mL, the composite microspheres still showed non-toxic onHeLa cells; The photothermal effect of separate copper sulfide nanocrystal material orNNC/CuS composite microspheres under the irradiation of the laser light condition can beused to kill tumor cells; With the extension of the irradiation time, the effects of CuSnano-crystal and composite microspheres on killing the tumor cells were more obvious; thiscomposite microspheres showed great potential for the development of thermal ablate therapy.