Search

Multivalent mannose-functionalized nanoparticles self-assembled from amphiphilic β-cyclodextrins (β-CDs) facilitate the targeted delivery of anticancer drugs to specific cancer cells. Doxorubicin (DOX)-loaded nanoparticles equipped with multivalent mannose target units were efficiently taken up via receptor-mediated endocytosis by MDA-MB-231 breast cancer cells that overexpress the mannose receptor. Upon entering the cell, the intracellular pH causes the release of DOX, which triggers apoptosis. Targeting by multivalent mannose significantly improved the capability of DOX-loaded nanoparticles to inhibit the growth of MDA-MB-231 cancer cells with minimal side effects in vivo. This targeted and controlled drug delivery system holds promise as a nanotherapeutic for cancer treatment. [ABSTRACT FROM AUTHOR]

Engineering multifunctional nanocarriers for targeted drug delivery shows promising potentials to revolutionize the cancer chemotherapy. Simple methods to optimize physicochemical characteristics and surface composition of the drug nanocarriers need to be developed in order to tackle major challenges for smooth translation of suitable nanocarriers to clinical applications. Here, rational development and utilization of multifunctional mesoporous silica nanoparticles (MSNPs) for targeting MDA-MB-231 xenograft model breast cancer in vivo are reported. Uniform and redispersible poly(ethylene glycol)-incorporated MSNPs with three different sizes (48, 72, 100 nm) are synthesized. They are then functionalized with amino- β-cyclodextrin bridged by cleavable disulfide bonds, where amino- β-cyclodextrin blocks drugs inside the mesopores. The incorporation of active folate targeting ligand onto 48 nm of multifunctional MSNPs (PEG-MSNPs48-CD-PEG-FA) leads to improved and selective uptake of the nanoparticles into tumor. Targeted drug delivery capability of PEG-MSNPs48-CD-PEG-FA is demonstrated by significant inhibition of the tumor growth in mice treated with doxorubicin-loaded nanoparticles, where doxorubicin is released triggered by intracellular acidic pH and glutathione. Doxorubicin-loaded PEG-MSNPs48-CD-PEG-FA exhibits better in vivo therapeutic efficacy as compared with free doxorubicin and non-targeted nanoparticles. Current study presents successful utilization of multifunctional MSNP-based drug nanocarriers for targeted cancer therapy in vivo. [ABSTRACT FROM AUTHOR]

Low durability and fuel cell performance block the widespread application of polymer electrolyte fuel cells (PEFCs). Here, we deposit platinum nanoparticles on carbon nanotubes (CNTs) before coating by end-capped hyperbranched sulfonated macromolecules (E-HBM), which could provide sufficient proton conductivity in catalyst layer thanks to the presence of −SO3H groups. The fabricated electrocatalyst loses 43 % of initial electrochemical surface area (ECSA) after 200 000 potential cycles from 1.0 V to 1.5 V vs. RHE, which is 3 and 20 times higher than that of noncoated and commercial electrocatalysts, respectively. The mass and specific activities of newly fabricated electrocatalyst measured before and after durability test are 1.4 times higher than that of commercial carbon black/Pt. Nafion ionomer-free membrane electrode assembly is fabricated from the newly designed electrocatalyst, and its fuel-cell performance reaches 668 mW cm−2 with Pt loading of 0.1 mg cm−2, which is twice higher than that of commercial CB/Pt thanks to the homogeneous conductive macromolecules (E-HBM) layers on CNTs acting as ionomer and facilitating the proton delivery in the catalyst layer. [ABSTRACT FROM AUTHOR]