Bone marrow mesenchymal stem cells-derived exosomes for penetrating and targeted chemotherapy of pancreatic cancer

Pancreatic ductal adenocarcinoma(PDAC) is one of the most intractable malignancy, with an only 6% 5-year relative survival rate. The dismal therapeutic effect is attributed to the chemotherapy resistance and unique pathophysiology with abundant inflammatory cytokines and abnormal hyperplasia of extracellular matrix(ECM). Based on the theory that bone marrow mesenchymal stem cells(BM-MSCs) can influence the tumorous microenvironment and malignant growth of PDAC, we employed exosomes(Exos) derived from BM-MSCs as PDAC-homing vehicles to surpass the restrictions of pathological ECM and increase the accumulation of therapeutics in tumor site. To overcome chemoresistance of PDAC, paclitaxel(PTX) and gemcitabine monophosphate(GEMP)-an intermediate product of gemcitabine metabolismd-were loaded in/on the purified Exos. In this work, the Exo delivery platform showed superiorities in homing and penetrating abilities, which were performed on tumor spheroids and PDAC orthotopic models. Meanwhile, the favorable anti-tumor efficacy in vivo and in vitro, plus relatively mild systemic toxicity, was found. Loading GEMP and PTX, benefitting from the naturally PDAC selectivity, the Exo platform we constructed performs combined functions on excellent penetrating, anti-matrix and overcoming chemoresistance(Scheme 1). Worth expectantly, the Exo platform may provide a prospective approach for targeted therapies of PDAC.

High lithium storage performance of Ni_(0.5)Fe_(0.5)O_(1-x)Nx thin film with Nio-type crystal structure

The large voltage hysteresis of the NiO anode,which owes much to the intermediate product Li_(2)NiO_(2),is one of the main obstacles to its practical application in lithium-ion batteries.In this work,we show that the incorporation of Fe-and N-ions in the Nio lattice can suppress the formation of intermediate product Li_(2)NiO_(2)and thus greatly reduces the voltage hysteresis of the Nioanode from~1.2 to~0.9 V.In comparison with the pure Nio electrode,the Nio.5Feo.5O1-xNx anode exhibits significantly enhanced reversible specific capacity(959 mAh·g^(-1)at 0.3 A·g^(-1)),cycling stability(capacity retention of 96.1%at 100th cycle relative to the second cycle)and rate capability(442 at 10 A·g^(-1)).These results provide a practical method to enhance the lithium storage performance of the Nio anode and more importantly a new solution to the large voltage hysteresis of conversion-type anodes.

Synthesis of non-classical heteroaryl C-glycosides via Minisci-type alkylation of N‑heteroarenes with 4-glycosyl-dihydropyridines

A radical-mediated method was reported for diastereoselective synthesis of non-classical heteroaryl C-glycosides via Minisci-type alkylation of N-heteroarenes with 4-glycosyl-1,4-dihydropyridine(DHP)reagents.These DHP reagents serve as convenient precursors for various glycosyl radicals under the activation of single electron transfer(SET)oxidation by persulfate and visible light irradiation with or without photocatalyst.