Microemulsion-Assisted Templating of Metal-Stabilized Poly(ethylene glycol) Nanoparticles

Engineering poly(ethylene glycol) particles for targeted drug delivery

Poly(ethylene glycol) (PEG) is considered to be the "gold standard" among the stealth polymers employed for drug delivery. Using PEG to modify or engineer particles has thus gained increasing interest because of the ability to prolong blood circulation time and reduce nonspecific biodistribution of particles in vivo, owing to the low fouling and stealth properties of PEG. In addition, endowing PEG-based particles with targeting and drug-loading properties is essential to achieve enhanced drug accumulation at target sites in vivo. In this feature article, we focus on recent work on the synthesis of PEG particles, in which PEG is the main component in the particles. We highlight different synthesis methods used to generate PEG particles, the influence of the physiochemical properties of PEG particles on their stealth and targeting properties, and the application of PEG particles in targeted drug delivery.

Functional materials contributing to the removal of chlorinated hydrocarbons from soil and groundwater: Classification and intrinsic chemical-biological removal mechanisms

Chlorinated hydrocarbons (CHs) are the main contaminants in soil and groundwater and have posed great challenge on the remediation of soil and ground water. Different remediation materials have been developed to deal with the environmental problems caused by CHs. Remediation materials can be classified into three main categories according to the corresponding technologies: adsorption materials, chemical reduction materials and bioaugmentation materials. In this paper, the classification and preparation of the three materials are briefly described in terms of synthesis and properties according to the different types. Then, a detailed review of the remediation mechanisms and applications of the different materials in soil and groundwater remediation is presented in relation to the various properties of the materials and the different challenges encountered in laboratory research or in the environmental application. The removal trends in different environments were found to be largely similar, which means that composite materials tend to be more effective in removing CHs in actual remediation. For instance, adsorbents were found to be effective when combined with other materials, due to the ability to take advantage of the respective strengths of both materials. The rapid removal of CHs while minimizing the impact of CHs on another material and the material itself on the environment. Finally, suggestions for the next research directions are given in conjunction with this paper.

Microencapsulation of Ionic Liquid by Interfacial Self-Assembly of Metal-Phenolic Network for Efficient Gastric Absorption of Oral Drug Delivery

Improving bioavailability of orally delivered drugs is still challenging, as conventional drug delivery systems suffer from non-specific drug delivery in the gastrointestinal (GI) tract and limited drug absorption efficiency. Gastric drug delivery is even more difficult due to the harsh microenvironment, short retention time, and physiologic barriers in the stomach. Here, an oral drug delivery microcapsule system was developed for gastric drug delivery, which consists of ionic liquid (IL) as the inner carrier and metal-phenolic network (MPN) as the microcapsule shell. The IL@MPN microcapsules are prepared by interfacial self-assembly of Fe^III and quercetin at the interface of hydrophobic IL ([EMIM][NTf₂]) and water. The formation of MPN shell could improve the stability of IL droplets in water and endow the system with pH-response drug release properties, while the encapsulated IL core could efficiently load the drug and enhance the drug tissue permeability. The IL@MPN microcapsules showed enhanced drug absorption in the stomach after oral administration in a rat model, where the microcapsules are disassembled in gastric acid, and the released IL could reduce the viscosity of mucus gel and increase the drug transport rate across endothelial cells. This work presents a simple yet efficient strategy for oral drug delivery to the stomach. Given the diversity and versatility of both MPN and IL, the proposed self-assembled microcapsules could expand the toolbox of drug delivery systems with enhanced oral drug bioavailability.

Plant-inspired Pluronic-gallol micelles with low critical micelle concentration, high colloidal stability, and protein affinity

Polymeric micelles are the most common carriers used for hydrophobic drug delivery. However, they are vulnerable to physiological barriers, such as temperature changes and enzymatic degradation, and can be easily disassembled upon dilution below the critical micelle concentration (CMC) by body fluids after an intravenous injection. Here, we report that Pluronic® micelles with octyl gallate, which is a surfactant containing gallol moieties widely found in antioxidative plant polyphenols, have a low CMC, which improves their colloidal stability without the need for covalent crosslinking. Furthermore, the incorporated gallol moieties provide enzymatic degradation resistance to the micelles owing to their protein affinity, maintaining the hydrophobic cavity of unmodified Pluronic®. Thus, plant-inspired polymeric micelles with low CMC and bioavailability are promising multifunctional vehicles for drug delivery.

Optimization Preparation of Indium Tin Oxide Nanoparticles via Microemulsion Method Using Orthogonal Experiment

Indium tin oxide (ITO), an experimentally friendly transparent conducting oxide (TCO), has attracted great attention in the photoelectric field due to its intrinsically low resistivity and high transparency. In this work, the experimental conditions of preparing ITO nanoparticles using the microemulsion method were optimized by an orthogonal experiment. The optimal experimental conditions were obtained: mass ratio of the surfactant (AEO-3, MOA-5), a co-surfactant (n-propyl alcohol) of 5:3, molar ratio of indium and ammonia of 1:20, calcination temperature of 700 °C and calcination time of 4 h. Subsequently, the influence from process variables on the resistivity was researched systematically. The results demonstrated that the calcination temperature had a great effect on the resistivity; the resistivity reduced from 11.28 to 2.72 Ω·cm with the increase in the calcination temperature from 500 to 700 °C. Ultimately, ITO nanoparticles were prepared and systematically characterized under the optimal experimental conditions. The particles with a size of 60 nm were attributed to the cubic ITO crystal phase and showed low resistivity of 0.3675 Ω·cm. Significantly, ITO nanoparticles with low resistivity were obtained using the microemulsion method, which has potential application in the field of ITO nanoparticle preparation.