Investigating the Effect of Microwave Induction on the Polymerization Rate of Polycarboxylate Superplasticizers.

As a transmission medium and heating energy, microwave is widely favored due to its high efficiency, strong selectivity, and easy control. Here, the effects of different heating methods (conventional thermal induction (CI) and microwave induction (MI)) on the polymerization rate of polycarboxylate superplasticizer (PCE) were investigated. Compared with CI, MI significantly boosted the polymerization rate (by approximately 51 times) and markedly decreased the activation energy (Ea), from 46.83 kJ mol-1 to 35.07 kJ mol-1. The polar of the monomers and initiators in the PCE synthesis contributes to varying permittivities and loss factors under the microwave field, which are influenced by their concentration and reaction temperature. The insights gained from the microwave thermal effects and the micro-kinetics of the PCE polymerization system are able to propose theoretical underpinnings for the industrial-scale application of microwave induction polymerization, potentially steering the synthesis of polymer materials towards a more efficient and cleaner process.

Recent Progress in Protein-Polyphenol Assemblies for Biomedical Applications.

Nowadays, natural materials as smart building blocks for assembling functional materials have aroused extensive interest in the scientific community. Proteins and polyphenols are typical natural building blocks that are widely used. On the one hand, proteins are one of the most versatile classes of biomolecules, serving as catalysts, signaling molecules, transporters, receptors, scaffolds that maintain the integrity of cell and tissue, and more. On the other hand, the facile adhesion of naturally abundant polyphenols with other substances and their potential biomedical applications have been highly attractive for functional biomaterials fabrication. Additionally, there are a variety of interactions between the proteins and polyphenols, mainly hydrogen bonding, hydrophobic, and ionic interactions. These reversible dynamic interactions enable proteins and polyphenols to form stable protein-polyphenol assemblies and maintain their inherent structures and biological activities in the assemblies. Therefore, protein-polyphenol assemblies can be applied to design a variety of advanced functional materials for biomedical applications. Herein, recent progress in protein-polyphenol particles, capsules, coatings, and hydrogels is summarized, the preparation and application of these assemblies are introduced in detail, and the future of the field is prospected.

Injectable and Self-Adaptive Gel Scaffold Based on Heparin Microspheres for Adipogenesis of Human Adipose-Derived Stem Cells.

An injectable and self-adaptive heparin microsphere-based cell scaffold was developed to achieve adipose regeneration. Simultaneously, the cell scaffold exhibited a dynamic architecture, self-regulated glucose levels, sustained insulin delivery, and steady viscoelastic properties for adipogenesis. The dynamic cell scaffold is cross-linked by the boronate-diol interaction among heparin-based microspheres, which have boronate and maltose groups. Because of the boronate-maltose ester bonds, the gelatinous complex would be partially dismantled and readily display glucose-sensitive performance by free glucose via competitive displacement. The dynamic cross-linking heparin microsphere scaffold can deliver the lipogenic drug insulin to enhance lipid filling, which has an impact on fat tissue enhancement. A 4-week in vitro cell culture demonstrated that the dynamic heparin microsphere-based cell scaffold, through loading with insulin, showed significantly higher efficiency in promoting ASC differentiation compared with traditional 3D culture methods. In vivo histological results further demonstrated that there was a significant increase in adipose in the proposed cell scaffold, which proved to be statistically significant compared with traditional biomaterials. Notable stain expression of the FABP4 and PPAR-γ genes was also observed in the dynamic cell scaffold containing insulin, which was more similar to natural fat.

Gelatin-based Targeted Delivery Systems for Tissue Engineering.

Gelatin is an attractive material for drug delivery and tissue engineering applications due to its excellent biocompatibility and biodegradability, which has been utilized as cell, drug, and gene carriers. Gelatin is less immunogenic compared to collagen and its precursor and retains informational signals, such as RGD (Arg-Gly-Asp) sequence, thus promoting cell adhesion and proliferation. To tune the mechanical strength and bioactivity, gelatin can be easily modified via chemical reactions and physical methods to obtain various derivatives. Furthermore, gelatin-based biomaterials can be achieved through chemical immobilization of specific molecules and physical combination with other biopolymers. This review focuses on the recent advances of gelatin and its derivatives as biomaterials in the field of drug delivery, including cell scaffolds for tissue engineering applications.

Safety Messaging Boosts Parental Vaccination Intention for Children Ages 5-11.

The COVID-19 vaccination rate among children ages 5-11 is low in the U.S., with parental vaccine hesitancy being the primary cause. Current work suggests that safety and side effect concerns are the primary reasons for such vaccine hesitancy. This study explores whether this hesitancy can be mitigated with information interventions. Based on theories of health decision making and persuasion, we designed four information interventions with varying contents and lengths. We wrote two messages on vaccine safety (a detailed safety-long message and a succinct safety-short message), explaining the vaccine's lower dosage, low rate of side effects, and the rigorous approval process. We also had two messages on protection effects (protect-family, protect-child). We combined these four messages with a vaccine-irrelevant control message and compared their effects on parental vaccine intention. We measured the parental vaccination intention using a 0-6 Likert scale question. Among the four intervention groups, we found that the short version of the safety message increased the average vaccination intention by over 1 point compared to the control arm, while the other three interventions failed to show significance. Specifically, these effects are particularly pronounced (around 2 points) for Republican parents who had a much lower initial intention to vaccinate their children. Our study highlights the importance of concise and to-the-point information rendering in promoting public health activities and therefore has important policy implications for raising vaccination intentions among parents, especially those leaning towards more conservative political affiliation.