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Upcycling is an eco-friendly method that turns waste into valuable items. Elemental sulfur, a waste substance produced in large amounts (70 million tons per year), can be converted into valuable polymers using inverse vulcanization. However, the traditional method had significant limitations, such as limited consumption and weak strength. To address this problem, we newly fabricated sulfur-based pressure-sensitive adhesives (PSAs). PSAs are soft and tacky materials that should have low modulus, and they are used extensively (3.1 million tons per year). We prepared sulfur-based PSAs in four steps: polymerization, dissolution, coating/drying, and curing. In the polymerization step, castor oil and oleic acid were employed to facilitate inverse vulcanization. The resulting polymer then underwent solvent-based depolymerization to be coated in a film form. After drying and ultra-violet (UV)-induced curing, the tapes were successfully produced. Significantly, we adjusted the PSA's crosslinking density by changing the oleic acid content and UV dose. As the amount of mono-functional oleic acid decreased or the UV dose increased, the resulting PSA's crosslinking density increased. The best conditions led to PSAs with excellent adhesion performances and creep resistance, similar to commercial tapes. Moreover, the prepared PSAs exhibited self-healing properties, suggesting the feasibility of high-performance PSAs like remoldable PSAs and conductive sensors.

Abstract In recent years, polymer-based tissue adhesives (TAs) have been developed as an alternative to sutures to close and seal incisions or wounds owing to their ease of use, rapid application time, low cost, and minimal tissue damage. Although significant research is being conducted to develop new TAs with improved performances using different strategies, the applications of TAs are limited by several factors, such as weak adhesion strength and poor mechanical properties. Therefore, the next-generation advanced TAs with biomimetic and multifunctional properties should be developed. Herein, we review the requirements, adhesive performances, characteristics, adhesive mechanisms, applications, commercial products, and advantages and disadvantages of proteins- and synthetic polymer-based TAs. Furthermore, future perspectives in the field of TA-based research have been discussed.

In this study, we synthesized a gallol-functionalized PSA and generated micropatterns on its surface to improve its underwater adhesion. Compared to the adhesive-substrate interactions of benzyl and phenol-functionalized PSAs in water, Gallol PSA exhibited greater interactions with the substrate. Furthermore, the micropattern on the PSA surface provided a drainage channel for water during the bonding process so that water is not trapped at the substrate-adhesive interface. Moreover, the drainage channel allows the formation of small and uniform adhesion defects, which minimize the deterioration in adhesion caused by water. And the adhesive manufacturing process is also simple, without any gallol protection and deprotection steps, and can be achieved using the current adhesive industry infrastructure. This facile fabrication strategy and its adhesive properties could promote the commercialization of gallol-functionalized PSAs with underwater adhesion.

Witch hazel extracts have been used for decades as cosmetic ingredients in skin care products. Our present study aims to evaluate its potential in anti-pollution products using a previously reported in vitro model. Calcium is a universal second messenger, and we used human respiratory and skin cells to detect changes in intracellular Ca2+ concentrations upon particulate matter contact. Both an increase in pro-inflammatory markers and a decrease in tight junction proteins were confirmed, as previously reported. Witch hazel stem and leaf extract showed significant attenuation of Ca2+ response upon the challenge; it displayed systematic regulations of the signal generator, PAR-2; a pro-inflammatory marker, NF-κB; and a tight junction protein, Occludin. We identified hexagalloylglucose from the extract and concluded that it is a major component regulating protection from particulate matter. Based on these results, witch hazel extract containing hexagalloylglucose is an active ingredient in anti-pollution skin care products.

Glomerular epithelial cells (GECs) are known to play a key role in maintaining the structure and function of the glomerulus. GEC injury induced by hyperglycemia is present in early-stage diabetic nephropathy (DN), which is the most common cause of renal failure. In an attempt to identify target proteins involved in the pathogenesis of GEC injury at early DN, we performed the proteomic analysis using primary cultures of GECs, prepared from the dissected rat glomeruli. The protein expression profiles in the two-dimensional electrophoresis gels were compared between GECs treated for three days with normal glucose (5 mM) and those with high glucose (30 mM) concentrations. These concentrations correspond to blood glucose concentrations under normoglycemia and hyperglycemia, respectively. Proteins with differential expression levels were identified using ESI-Q-TOF tandem mass spectrometry. The primary GECs cultured in hyperglycemic conditions showed cellular hypertrophy and increased production of reactive oxygen species, both of which reflect the GEC injury. Our proteomic analysis identified eight proteins with differential expression profiles, depending on glucose concentrations. Among them, we selected ATP synthase β subunit and enolase 2 that are related to energy metabolism and are down-regulated under hyperglycemia, and confirmed that hyperglycemia decreased the expression levels of ATP synthase β subunit and enolase 2 proteins by western blotting analysis. Hyperglycemia may impair mitochondrial function and alter glycolysis in GECs by down-regulating the expression of ATP synthase β subunit and enolase 2. The present study may provide a better understanding of the pathogenic mechanisms of GEC injury in early DN. [ABSTRACT FROM AUTHOR]

Dietary supplement and personal care products aiming to provide protection from air pollution have been of great interest for decades. Epidemiology demonstrated that PM10 and PM2.5 particulate matter (PM) are an actual threat to public health worldwide, but the detailed processes of how these particles attack the cells are not fully understood. Here, we report that the measurement of intracellular calcium concentration ([Ca2+]i) using human respiratory or skin cells can illustrate pollutant challenges by triggering Ca2+ influx in these cells. This signal was generated by proteinase-activated receptor-2 (PAR-2), confirmed by competition analyses, and Phellodendron amurense bark extract (PAE), a traditional medicine, was able to control the response and expression of PAR-2. Increase in proinflammatory cytokines and decrease in cell adhesion components could suggest a severe damage status by air pollutants and protection by PAE. Finally, we identified 4-O-feruloylquinic acid (FQA), an active compound of PAE, showing the same effects on Ca2+ influx and PAR-2 regulation. The results presented here should help understand the underlying mechanism of PM insults and the beneficial effect of standardized PAE as dietary supplement or cosmetical ingredient.