Intelligent, efficient silica nanoparticles for drug delivery system in cancer therapy have a great application potential, but the biodegradability of silica nanoparticles becomes an intractable hindrance. In this work, novel reactive oxygen species (ROS)-responsive hollow mesoporous organosilica nanoparticles (HMONs) coated with polydopamine (PDA) biofilm and amino-terminated methoxy poly(ethylene glycol) (mPEG-NH[Formula: see text] were synthesized and applied in the smart drug delivery system (HMONs@PDA-mPEG) for the delivery of doxorubicin (DOX). The nanostructures and morphologies of nanoparticles were characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 adsorption/desorption, dynamic light scattering (DLS) and thermogravimetric analysis. Based on the “chemical homology” mechanism, physiologically active thioacetal-bridged silsesquioxane was molecularly incorporated into the framework of silica nanoparticles to form ROS-responsive HMONs, which was verified by the in vitro degradation experiment. The in vitro drug release profiles showed a synergistically pH-dependent and ROS-responsive drug release effect. MTT assay toward A549 cells demonstrated that drug carriers had a biocompatibility, and DOX-loaded nanoparticles (DNs) presented a concentration-dependent and time-dependent cell growth inhibition effect. In summary, the novel ROS-responsive HMONs@PDA-mPEG had a promising application as a smart drug delivery system in biomedical field.
In this work, Zn‐incorporated titanium substrate with nano network structures was built, and its antibacterial activity against the gram positive and negative bacteria was tested. Ti plate was successively treated by hot alkaline, Zn2+ ion‐exchange, and ZnO nanoparticles deposit, where alkaline treated Ti plate (NTi), Zn2+ exchanged Ti plate (NZTi), Zn2+/ZnO incorporated Ti plate (NZZTi) were correspondingly generated. For Escherichia coli, the antibacterial percentage of NZTi and NZZTi after 24 h was 99.86 % and 99.98 %, while it was 99.95 % and 100 % for Staphylococcus aureus, respectively. The result disclosed that NZZTi have a bit better antibacterial activity than NZTi, which indicates that Zn2+ shows fabulous antibacteria activity and the presence of ZnOnps can contribute the antibacterial ability of Ti plates, which agrees with result of NZZTi‐Cup antibacterial effect. The release tests of Zn2+ after 8 days from NZZTi‐Cup disclosed that Zn‐incorporated Ti plate could consecutively release trace Zn ions.
Heavy metal ions in water can affect human health. Taking Pb 2 + for an example, it can lead to kidney failure and tumor infection. Polyvinylidene fluoride (PVDF) has been widely used as filter membranes in wastewater treatment. This paper uses citric acid (CA) as the connecting arm to graft carboxymethyl chitosan (CMCS) onto PVDF and prepare a novel granular molecular sieve-supported PVDF derivative (s-PVDF-CA-CMCS). The structure was characterized and the adsorption capacity for heavy metal ions was investigated. The results indicate that s-PVDF-CA-CMCS has good adsorption performance for aqueous heavy metal ions, especially for Pb 2 + , with a removal rate of 99.39 % and an adsorption capacity of 198.41 μg/g. The adsorption data fits the pseudo-second-order kinetic model (R 2 = 0.9992), and the removal rate of Pb 2 + was 78.48 % after 5 cycles of adsorptions, indicating that s-PVDF-CA-CMCS may be potential applications for removing heavy metal ions in water treatment.
Three novel donor-acceptor (D-A) conjugated copolymers for polymer solar cells (PSC) are presented in this work. By Stille coupling polymerization, indacenodithiophene (IDT), as an electron-rich unit, was conjugated with an electron-deficient unit of isoindigo (IID), which led to a novel alternative copolymer IDT-IID (P1). Two electron-deficient units, 2,1,3-benzooxadiazole (BO) and diketopyrrolopyrrole (DPP), were respectively introduced in the polymerization of P1, and two novel IDT-based D-A 1 -D-A 2 random copolymers IDT-IID-IDT-BO (P2) and IDT-IID-IDT-DPP (P3) were obtained. Thermal property tests indicated that these molecules possess relative stability and are suitable for solar cell applications. Optical and electrochemical measurements revealed that the HOMO energy levels of the three copolymers were À5.46 eV, À5.34 eV, and À5.23 eV respectively, while the LUMO levels were almost kept stable around À3.56 eV and the low band gap levels led to complete absorption in the visible region. The PSCs based on these copolymers were fabricated with the structure of ITO/PEDOT : PSS/polymer : PC 71 BM/Ca/Al, and the photovoltaic properties disclosed the relatively high values of open circuit voltage (V oc ) due to the lowlying HOMO energy levels of each copolymer. Hole mobility and atomic force microscopy (AFM) study were applied to improve the PSCs performance. Our work provides an efficient method to regulate the HOMO energy levels which will be beneficial for PSCs by synthesizing different conjugated copolymers.
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