Preparation of thermo-responsive PNIPAAm-MWCNT membranes and evaluation of its antifouling properties in dairy wastewater

Investigation of temperature-responsive tocosomal nanocarriers as the efficient and robust drug delivery system for Sunitinib malate anti-cancer drug: Effects of MW and chain length of PNIPAAm on LCST and dissolution rate

In this study, for the first time, the coated tocosome by blend of chitosan, CS, and poly(N-isopropylacrylamide), PNIPAAm, was developed as the efficient and robust drug delivery system with improved drug encapsulation efficiency, extended stability, proper particle size and industrial upscaling for Sunitinib malate anti-cancer drug. Tocosome was synthesized by using Mozafari method as a scalable and robust method and without the need for organic solvents. The effects of tocosome composition and drug concentration on the stability, particle size of tocosome, zeta potential, encapsulation efficacy and loading of drug into it were investigated by Taguchi method, and optimum composition was selected for combining with the polymeric blend. Homopolymer of PNIPAAm was synthesized by two different polymerization methods, including free radical and reversible addition-fragmentation chain transfer (RAFT). Effects of molecular weight (MW) and chain length of the polymers on lower critical solution temperature (LCST) were examined. The developed nanocarrier in this research, CS-Raft-PNIPAAm-tocosome, indicated LCST value beyond 37°C (about 45°C) and this is suitable for hyperthermia and spatio-temporal release of drug particles.

Removal of Humic Acid Using 3-Methacryloxypropyl Trimethoxysilane Functionalized MWCNT Loaded TiO2/PES Hybrid Membrane

In the present work, a highly efficient mixed matrix membrane (MMM) for humic acid (HA) removal was developed. Multiwalled carbon nanotubes (MWCNTs) were functionalized in the presence of 3-methacryloxypropyl trimethoxysilane using the co-condensation method and were subsequently loaded with TiO2 (prepared via the sol-gel route). The as-prepared material was then incorporated into a PES polymer solution to prepare a fMWCNT-TiO2/PES hybrid membrane via non-solvent induced phase inversion. The microstructure of the membrane was characterized using Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy, water contact angle, thickness, porosity, and pore size. The fMWCNT-TiO2/PES hybrid membrane was tested for the removal of HA and antifouling performance. The results show that the surface hydrophilicity of the membranes was greatly improved upon the addition of the fMWCNT-TiO2 particles. The results show that 92% of HA was effectively removed after 1 h of filtration. In comparison with pristine membrane, the incorporation of fMWCNT-TiO2 nanoparticles led to enhanced pure water flux (99.05 L/m2 h), permeate flux (62.01 L/m2 h), higher HA rejection (92%), and antifouling improvement (RFR: 37.40%, FRR: 86.02%). Thus, the fMWCNT-TiO2/PES hybrid membrane is considered to be a great potential membrane for the improvement of ultrafiltration membranes.

The Mechanisms and the Applications of Antibacterial Polymers in Surface Modification on Medical Devices

Medical device contamination caused by microbial pathogens such as bacteria and fungi has posed a severe threat to the patients' health in hospitals. Due to the increasing resistance of pathogens to antibiotics, the efficacy of traditional antibiotics treatment is gradually decreasing for the infection treatment. Therefore, it is urgent to develop new antibacterial drugs to meet clinical or civilian needs. Antibacterial polymers have attracted the interests of researchers due to their unique bactericidal mechanism and excellent antibacterial effect. This article reviews the mechanism and advantages of antimicrobial polymers and the consideration for their translation. Their applications and advances in medical device surface coating were also reviewed. The information will provide a valuable reference to design and develop antibacterial devices that are resistant to pathogenic infections.