Thermosensitive tribrachia star-shaped s-P(NIPAM-co-DMAM) random copolymer micelle aggregates: Preparation, characterization, and drug release applications

Room-Temperature Self-Healable Blends of Waterborne Polyurethanes with 2-Hydroxyethyl Methacrylate-Based Polymers

The design of self-healing agents is a topic of important scientific interest for the development of high-performance materials for coating applications. Herein, two series of copolymers of 2-hydroxyethyl methacrylate (HEMA) with either the hydrophilic N,N-dimethylacrylamide (DMAM) or the epoxy group-bearing hydrophobic glycidyl methacrylate were synthesized and studied as potential self-healing agents of waterborne polyurethanes (WPU). The molar percentage of DMAM or GMA units in the P(HEMA-co-DMAMy) and P(HEMA-co-GMAy) copolymers varies from 0% up to 80%. WPU/polymer composites with a 10% w/w or 20% w/w copolymer content were prepared with the facile method of solution mixing. Thanks to the presence of P(HEMA-co-DMAMy) copolymers, WPU/P(HEMA-co-DMAMy) composite films exhibited surface hydrophilicity (water contact angle studies), and tendency for water uptake (water sorption kinetics studies). In contrast, the surfaces of the WPU/P(HEMA-co-GMAy) composites were less hydrophilic compared with the WPU/P(HEMA-co-DMAMy) ones. The room-temperature, water-mediated self-healing ability of these composites was investigated through addition of water drops on the damaged area. Both copolymer series exhibited healing abilities, with the hydrophilic P(HEMA-co-DMAMy) copolymers being more promising. This green healing procedure, in combination with the simple film fabrication process and simple healing triggering, makes these materials attractive for practical applications.

Functional Nanoparticles for Enhanced Cancer Therapy

Cancer is the leading cause of death in people worldwide. The conventional therapeutic approach is mainly based on chemotherapy, which has a series of side effects. Compared with traditional chemotherapy drugs, nanoparticle-based delivery of anti-cancer drugs possesses a few attractive features. The application of nanotechnology in an interdisciplinary manner in the biomedical field has led to functional nanoparticles achieving much progress in cancer therapy. Nanoparticles have been involved in the diagnosis and targeted and personalized treatment of cancer. For example, different nano-drug strategies, including endogenous and exogenous stimuli-responsive, surface conjugation, and macromolecular encapsulation for nano-drug systems, have successfully prevented tumor procession. The future for functional nanoparticles is bright and promising due to the fast development of nanotechnology. However, there are still some challenges and limitations that need to be considered. Based on the above contents, the present article analyzes the progress in developing functional nanoparticles in cancer therapy. Research gaps and promising strategies for the clinical application are discussed.

Investigation of nanoscale zerovalent iron-based magnetic and thermal dual-responsive composite materials for the removal and detection of phenols

In this study, well-defined magnetic and thermal dual-responsive nanomaterials were synthesized, which contained ultrafine core-shell Fe@SiO₂ nanoparticles as magnetic core and poly(N-isopropylacrylamide) (PNIPAM) as thermosensitive outer shell. The fabricated nanoparticles were characterized and investigated for the adsorption of four phenolic compounds, including bisphenol A (BPA), tetrabromobisphenol A (TBBPA), 4-tert-octylphenol (4-OP) and 4-n-nonylphenol (4-NP). The experimental results demonstrated that the excellent adsorption rates were attributed to hydrophobic effect, hydrogen-bonding interaction, and electrostatic attraction. The adsorption process followed pseudo-second-order kinetics model and nonlinear isotherms, indicating heterogeneous adsorption process. The adsorption efficiency of 4-NP using Fe@SiO₂@PNIPAM was more than 90% under optimized condition within 2 h. The determined maximum adsorption amounts of BPA, TBBPA, 4-OP and 4-NP were 2.43, 6.83, 24.75, and 49.34 mg g^-1, respectively. Meanwhile, a magnetic solid phase extraction (MSPE) method with Fe@SiO₂@PNIPAM was established to determine these four compounds simultaneously. Under the optimal conditions, the linearity ranges were in the range of 2-200, 2-300, 2-100 and 2-100 μg L^-1 for BPA, 4-OP, TBBPA, and 4-NP, respectively, and the detection limits were in the range of 0.58-0.76 μg L^-1, respectively. The applicability of the proposed method was evaluated by analyzing three fresh water samples, and satisfactory spiked recoveries in the range 70.9-119.9% were achieved. It was proved that these adsorbents could be easily collected and recycled owing to the appropriate magnetism. The results also demonstrated that the as-prepared adsorbents had promising potential in the enrichment and analysis of detrimental organic pollutants from water.

Selective Transport through Membranes with Charged Nanochannels Formed by Scalable Self-Assembly of Random Copolymer Micelles

Membranes that can separate compounds based on molecular properties can revolutionize the chemical and pharmaceutical industries. This study reports membranes capable of separating organic molecules of similar size based on their electrostatic charge. These membranes feature a network of carboxylate-functionalized 1-3 nm nanochannels, manufactured by a simple, scalable coating process: a porous support is coated with a packed array of polymer micelles in alcohol, formed by the self-assembly of a water-insoluble random copolymer with fluorinated and carboxyl functional repeat units. The interstices between these micelles serve as charged nanochannels through which water and solutes can pass. The negatively charged carboxylate groups lead to high separation selectivities between organic solutes of similar size but different charge. In single-solute diffusion experiments, neutral solutes permeate up to 263 times faster than negatively charged compounds of similar size. This selectivity is further enhanced in experiments with mixtures of these solutes. No permeation of the anionic compound was observed for over 24 h. In filtration experiments, these membranes separate anionic and neutral organic compounds while exhibiting water fluxes comparable to that of commercial membranes. Furthermore, carboxylate groups can be functionalized, creating membranes with nanopores with customizable functionality to enable a broad range of selective separations.

Temperature-Responsive Smart Nanocarriers for Delivery Of Therapeutic Agents: Applications and Recent Advances

Smart drug delivery systems (DDSs) have attracted the attention of many scientists, as carriers that can be stimulated by changes in environmental parameters such as temperature, pH, light, electromagnetic fields, mechanical forces, etc. These smart nanocarriers can release their cargo on demand when their target is reached and the stimulus is applied. Using the techniques of nanotechnology, these nanocarriers can be tailored to be target-specific, and exhibit delayed or controlled release of drugs. Temperature-responsive nanocarriers are one of most important groups of smart nanoparticles (NPs) that have been investigated during the past decades. Temperature can either act as an external stimulus when heat is applied from the outside, or can be internal when pathological lesions have a naturally elevated termperature. A low critical solution temperature (LCST) is a special feature of some polymeric materials, and most of the temperature-responsive nanocarriers have been designed based on this feature. In this review, we attempt to summarize recent efforts to prepare innovative temperature-responsive nanocarriers and discuss their novel applications.