PEGylated mBPEI-rGO nanocomposites facilitate hepotocarcinoma treatment combining photothermal therapy and chemotherapy

Despite chemotherapy has been widely used for tumor therapy, the serious side effect is still a major challenge. Recently, two dimensional nanomaterial-based drug delivery systems have attracted wide concern due to their high drug loading and low side effect. In addition, some kinds of nanomaterials can directly act as a photosensitizer to induce cancer destruction. In this study, we developed a drug delivery system of mixture of high/low molecular weight branched polyethylenimine-polyethylene glycol-reduced graphene oxide(mBPEI-PEG-rGO) using reduced graphene oxide as matrix. A model drug of doxorubicin(DOX) was loaded on the nanocomposites with the efficiency of 81% and the release rate of more than 50% at acidic environment. In vitro experiments indicated that mBPEI-PEG-rGO-DOX with enhanced stability and biocompatibility efficiently delivered and released DOX into cells mainly through micropinocytosis and killed SMMC-7721 cells by inducing reactive oxygen species(ROS) and cell apoptosis. Furthermore, in vivo experiments indicated that the combination of intratumoral injection of mBPEI-PEG-rGO-DOX and local laser irradiation nearly ablated hepatocarcinoma. In conclusion, this new drug delivery system provided an alternative for combinational photothermal and chemotherapy against hepatocarcinoma.

Novel sulfhydryl functionalized covalent organic frameworks for ultra-trace Hg^(2+) removal from aqueous solution

Two kinds of novel sulfhydryl functionalized covalent organic frameworks were fabricated as adsorbents for the removal of ultra-trace concentrations of Hg^(2+)from water.The two kinds of sulfhydryl functionalized covalent organic frameworks were obtained via a thiol-ene click reaction between the thiol groups of trithiocyanuric acid(TTC)or bismuththiol(BMT)and vinyl groups on the surface of covalent organic frameworks.The material structure was characterized by XRD,SEM,EDS,FT-IR,BET,and TG analysis.Due to their rich sulfur content,both adsorbents(COF-SH-1 and COF-SH-2)exhibited a high level of selective Hg^(2+)removal from aqueous solution with maximum adsorption capacities of 763.4 mg g^(-1) and526.3 mg g^(-1),respectively.Furthermore,in the presence of ultra-low concentrations of Hg^(2+)both materials exhibited excellent performance,achieving rapid Hg^(2+)removal at concentrations from 10μg L^(-1) to less than 0.02 ng L^(-1).Analysis of the adsorption mechanism indicates that the sulfur containing chelating groups exhibit a strong binding capacity for Hg^(2+).Results show that the structure determines the performance,with the amount of adsorption sites being related to the adsorption capacity.Therefore,as sulfhydryl functionalized covalent organic frameworks contain an abundance of adsorption sites,these materials can effectively achieve the removal of ultra-low trace Hg^(2+)concentrations and have promising future application potential for the environmental detection of heavy metals.