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Shortcomings of the conventional PLA synthesis methods have encouraged researchers to investigate on alternative methods for PLA synthesis. Utilization of chain extenders is an effective way to achieve high MW polymers. The concept of using star-shaped resins as the reinforced matrices for biocomposites or in biomedical applications is gaining more and more attention day by day. Star-shaped lactic acid based resins are a class of branched resins with a multifunctional core molecule and lactic acid branches. In order to increase the reactivity of branches, the star-shaped resin oligomers can get end-functionalized which yields in a crosslinkable product. Changing the architecture of a polymer from a linear to a multiarm or hyperbranched one, would change its chemical, diffusional and physical-mechanical properties. This review paper presents the current state and recent advances in the synthesis, characterization, properties and applications of the star-shaped resins made from lactic acid or lactide and multi-hydroxyl core molecules with a focus on the role of the architecture of the polymer on the properties of resins. Rheological, physiochemical and thermomechanical properties of to date synthesized star-shaped resins are compared and discussed. Special emphasis would be made on potential opportunities, probable applications and also gaps and drawbacks concerning these systems. This review aims to provide useful information to help future development of efficient, highly engineered bioresins which can be especially designed for certain applications. [ABSTRACT FROM AUTHOR]

[Display omitted] The progress of soft robot industry has driven the development of electronic devices. Electronic devices used in electronic skin or wearable electronic devices require conductive materials with high sensitivity and stretchability, while traditional inorganic conductive materials such as metals and metal oxides cannot meet both conductivity and flexibility. Conductive hydrogels realize the complementary characteristics of conductive materials and hydrogels. On the basis of conductive materials ensuring electrical conductivity, hydrogels make up for the defect of unbendable material to a large extent and become the substitute of traditional inorganic conductive material. In order to adapt to different working environments, conductive hydrogels also have more excellent properties, such as mechanical properties, self-healing properties, and resistance to extreme environments, which further broadens the application field of conductive hydrogels. So far, conductive hydrogels have found wide applications in biomedicine, sensors and energy storage devices. In this paper, the research progress of conductive hydrogels in recent years is reviewed, and the conductive mechanisms of hydrogels can be divided into electronic conductive mechanism and ionic conductive mechanism. Then, the properties and applications of conductive hydrogels are described. Finally, the problems and shortcomings of conductive hydrogels were summarized, and the future development of conductive hydrogels was prospected. [ABSTRACT FROM AUTHOR]

[Display omitted] Two-dimensional (2D) transition metal carbide/nitride (MXene) has been a hot topic of research since it was proposed in 2011. Etching methods to obtain MXene from MAX phase have been continuously investigated. The excellent hydrophilicity, conductivity and tunability make MXene widely used in electrochemistry. In addition, the development of wearable sensors has promoted the research of conductive hydrogels, and improving the performance of conductive hydrogels is still an area of effort for researchers. Therefore, the incorporation of MXene into hydrogel systems will result in significant improvements in performance. This paper reviews the etching methods of MXene, the synthesis strategies and applications of MXene conductive hydrogels, and provides an outlook on the future development of MXene and MXene conductive hydrogels. [ABSTRACT FROM AUTHOR]

[Display omitted] Recently, the combination of cosmetology and microneedle therapy has made great progress. Compared with direct injection, microneedles not only have functions of targeted delivery and high bioavailability, but also have characteristics of painless, mild and convenient. Also, it is beneficial to users' self-administration. Therefore, microneedles are more inclined to be treated by patients with cosmetic needs. Since microneedles were first applied in the cosmetic field in 2005, new products have emerged one after another, and the application of microneedles in wrinkle-removing, scar-treating, whitening, fat-reducing and other aspects has been greatly improved. Meanwhile, the composition of microneedles is a key factor affecting the preparation process, drug loading/release capacity, stability and final effect of microneedles. This paper reviews the commonly used matrix materials, loading drugs and preparation methods of cosmetic microneedles from the perspective of materials, in order to provide basic reference for the preparation of cosmetic microneedles. It is vital to detail the representative applications of microneedles in cosmetology. In conclusion, as a new tool, microneedle system shows great promise in cosmetic application. [ABSTRACT FROM AUTHOR]

Molecular imprinting technology (MIT) aims to prepare polymers with tailor-made binding sites for the templates in shape, size and functional groups. However, many disadvantages of traditional MIT lead to some unsatisfactory results. Recently, surface molecular imprinting technique (SMIT) has aroused extensive attention and been applied in many fields, such as sensors, separation and purification, catalysis and biomedical areas owing to the desired selectivity, reduction of "embedding" phenomenon, fast mass transfer rate and binding kinetics. With the rapid development of SMIT, it faces a number of challenges, involving pure templates obtained, the higher cost of using noble metals, unclear recognition mechanism, low solubility of the templates in solvents, etc., which limit its practical applications in various aspects. This paper briefly reviews current status of the SMIT, particularly emphasis on the preparation of surface molecularly imprinted polymers (SMIPs, including interactions between templates and monomers, solid matrixes and synthetic strategies) and significant applications on sensors, separation and purification, catalysis and biomedical areas. Furthermore, some still existing challenges and future prospects in this research area are also highlighted. [ABSTRACT FROM AUTHOR]