Green synthesis of chitosan- and fluoride-functionalized silver nanoparticles using Camellia sinensis: Characterization and dental applications.

The development of new biocompatible and eco-friendly materials is essential for the future of dental practice, especially for the management of dental caries. In this study, a novel and simple method was applied for the green synthesis of silver nanoparticles (AgNPs) from the aqueous extract of Camellia sinensis (WT) and functionalized with chitosan (CHS) and NaF. The effects of WT_AgNPs application on demineralized dentin were evaluated for potential dental applications. The WT_AgNPs showed molecular groups related to organic compounds, potentially acting as reducing and capping agents. All AgNPs presented spherical shapes with crystal sizes of approximately 20 nm. Forty human molars were assigned to control: sound (SD) and demineralised dentine (DD), and experimental groups: WT_AgNPs, WT_AgNPs_NaF, and WT_AgNPs_CHS. Then, the NPs were applied to DD to evaluate the chemical, crystallographic, and microstructural characteristics of treated-dentine. In addition, a three-point bending test was employed to assess mechanical response. The application of WT_AgNPs indicated a higher mineralisation degree and crystallites sizes of hydroxyapatite than the DD group. SEM images showed that WT_AgNPs presented different degrees of aggregation and distribution patterns. The dentine flexural strength was significantly increased in all WT_AgNPs. The application of WT_AgNPs demonstrated remineralising and strengthening potential on demineralised dentine.

Clean beauty: artigo de revisão sobre a nova tendência em cosméticos / Clean beauty - literature review of new trends in cosmetics

Nos últimos anos, cresce a tendência pela busca de cosméticos "amigos da natureza", sem ingredientes químicos ou sintéticos, impulsionando as vendas de produtos pertencentes a este nicho de mercado. Atualmente, o termo clean beauty refere-se a produtos que não contenham ingredientes sobre os quais não se conheça o impacto que terão em nosso organismo ou seu potencial dano ambiental. Entretanto, a definição do que é um cosmético verde, bem como vegano, natural e orgânico, não é regulamentada pela Agência Nacional de Vigilância Sanitária (Anvisa), sendo o objetivo deste artigo fazer uma revisão das definições para facilitar o entendimento médico sobre o tema.

In recent years, there has been an increasing trend toward the search for nature-friendly cosmetics without chemical or synthetic ingredients, thus boosting sales of products within this market niche. Currently, the term clean beauty refers to products that do not contain ingredients with unknown impacts on our bodies or that are potentially harmful to the environment. However, the definition of green beauty products, as well as vegan, natural, or organic products, is not regulated by ANVISA. Therefore, this study aimed to review these definitions to facilitate the medical understanding of the subject

New trends in the use of enzymes for the recovery of polyphenols in grape byproducts.

Residues from wine and juice processing still contain about 70% of the phenolic compounds in grapes. These compounds are valued for having several bioactive properties that are explored in the pharmaceutical and food sectors. This paper aims to summarize the most recent advances in the use of enzymatic techniques for the recovery of bioactive compounds from GP for industrial application. For this, we analyzed scientific articles and patent applications from the last 20 years in the main indexed and patent databases. Among the most used enzymes in the recovery of bioactive compounds in wastes, cellulases, pectinases, tannases, glucoamylases, and proteases such as trypsin and chymotrypsin, are the most important. As a result, extracts are obtained with greater retrieval of compounds such as anthocyanins, gallic acid, catechins, epicatechins, and trans-resveratrol and the improvement of coloring, anti-inflammatory, antioxidant and vasoprotective properties. Although the use of enzymes for the recovery of phenolics is an old strategy, the number of studies focusing on the functional characteristics and industrial applicability of the extracts obtained has been recently growing. PRACTICAL APPLICATIONS: Phenolic compounds have acted as anti-inflammatories, antioxidants, anticarcinogens, and antimicrobials, being additives or relevant ingredients for various products in the food and pharmaceutical industry. Although there are several techniques for extracting/recovering phenolics from grape pomace, there is still no agreement on which method is ideal. In recent years, several extractions methods have been applied in seeking optimized conditions to recover phenolics from grape residues. Among them, the use of enzymes has been gaining attention for being considered a green and promising technology. The present study aims to carry out a review that would bring a new perspective to the recovery of bioactive compounds from grape residues by enzymatic techniques, with a view to industrial purpose.

An Aqueous Facile Synthesis of 2,3-Dihydroquinazolin-4(1H)-One Derivatives by Reverse Zinc Oxide Micelles as Nanoreactor.

A green synthetic protocol has been developed for the efficient preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives with excellent yield in aqueous media. Reverse zinc oxide micelles catalyzed the reactions efficiently and selectively as the hallow nanoreactor. Moreover, the catalyst was reusable without significant loss of catalytic efficiency. The notable advantages of the procedure are high yields and mild reaction conditions, simple operation, nonchromatographic purification, environmentally friendly and good versatile substrates.

Crystal growth in dentinal tubules with bio-calcium carbonate-silica sourced from equisetum grass.

BACKGROUND/PURPOSE: One effective way to deal with dentin hypersensitivity is to develop materials to seal the tubules. The porous bio-calcium carbonate-silica (BCCS) contained well-dispersed CaCO3 would form calcium phosphates to seal the dentinal tubules when mixed with an acidic solution. The acidic hydrothermal treatment and calcination to isolate the BCCS from the agricultural waste like equisetum grass was used, which would be more environmentally friendly than chemically synthesized mesoporous biomaterials. The aim of this study was to develop mesoporous materials from natural resources to occlude the dentinal tubules which could be more environmentally-friendly. METHODS: Dentin disc samples were prepared and treated with different methods as follows: (1) BCCS mixed with H3PO4; (2) BCCS mixed with KH2PO4; (3) Seal & Protect® was used as a comparison group. Sealing efficacy was evaluated by measuring the depths and percentages of precipitate occlusion in dentinal tubules with SEM. RESULTS: The N2 adsorption-desorption isotherm of the BCCS demonstrated a pore size of around 15.0 nm and a surface area of 61 m2g-1. From the results of occlusion percentage and depth, the BCCS treated with H3PO4 or KH2PO4 demonstrated promising sealing efficacy than the commercial product. CONCLUSION: This synthetic process used the agricultural waste equisetum grass to produce bio-calcium carbonate-silica would be environmentally friendly, which has great potential in treating exposed dentin related diseases.

Research on the development of green chemistry technology assessment techniques: a material reutilization case.

OBJECTIVES: This study presents a methodology that enables a quantitative assessment of green chemistry technologies. METHODS: The study carries out a quantitative evaluation of a particular case of material reutilization by calculating the level of "greenness" i.e., the level of compliance with the principles of green chemistry that was achieved by implementing a green chemistry technology. RESULTS: The results indicate that the greenness level was enhanced by 42% compared to the pre-improvement level, thus demonstrating the economic feasibility of green chemistry. CONCLUSIONS: The assessment technique established in this study will serve as a useful reference for setting the direction of industry-level and government-level technological R&D and for evaluating newly developed technologies, which can greatly contribute toward gaining a competitive advantage in the global market.

Priority survey between indicators and analytic hierarchy process analysis for green chemistry technology assessment.

OBJECTIVES: This study presents the indicators and proxy variables for the quantitative assessment of green chemistry technologies and evaluates the relative importance of each assessment element by consulting experts from the fields of ecology, chemistry, safety, and public health. METHODS: The results collected were subjected to an analytic hierarchy process to obtain the weights of the indicators and the proxy variables. RESULTS: These weights may prove useful in avoiding having to resort to qualitative means in absence of weights between indicators when integrating the results of quantitative assessment by indicator. CONCLUSIONS: This study points to the limitations of current quantitative assessment techniques for green chemistry technologies and seeks to present the future direction for quantitative assessment of green chemistry technologies.

Study on the biodegradation of alternatives (four species including C8H8F9KO3S) for perfluorooctane sulfonate.

OBJECTIVES: The objective of this study was to evaluate the biodegradation potential of four perfluorooctane sulfonic acid (PFOS) alternatives that were developed at Changwon National University. While PFOS has been used widely in industrial and consumer products, it is known to be a persistent organic pollutant. Therefore, greener alternatives are highly desirable. METHODS: Biodegradation tests were run for 28 days using standard test protocols. The biochemical oxygen demand was measured daily throughout the experimental period, and the data were used to calculate the biodegradation rates. Microorganisms were isolated from the some of the tests that showed evidence of biodegradation. RESULTS: C8H8F9KO3S, which has the same number of carbons as the parent compound PFOS but a reduced number of fluorines, showed the highest biodegradation rate followed by C10H8F13KO3S. Chemical alternatives with lower number of carbons did not biodegrade readily in the experiments. CONCLUSIONS: Together, these results suggest that it may be advantageous to develop PFOS alternatives with 8 carbons, the same as PFOS, but a reduced number of fluorines; as such, chemicals are more susceptible to biodegradation than the parent compound.

Research on the development of green chemistry technology assessment techniques: a material reutilization case

OBJECTIVES: This study presents a methodology that enables a quantitative assessment of green chemistry technologies. METHODS: The study carries out a quantitative evaluation of a particular case of material reutilization by calculating the level of "greenness" i.e., the level of compliance with the principles of green chemistry that was achieved by implementing a green chemistry technology. RESULTS: The results indicate that the greenness level was enhanced by 42% compared to the pre-improvement level, thus demonstrating the economic feasibility of green chemistry. CONCLUSIONS: The assessment technique established in this study will serve as a useful reference for setting the direction of industry-level and government-level technological R&D and for evaluating newly developed technologies, which can greatly contribute toward gaining a competitive advantage in the global market.

Research on the development of green chemistry technology assessment techniques: a material reutilization case

OBJECTIVES: This study presents a methodology that enables a quantitative assessment of green chemistry technologies. METHODS: The study carries out a quantitative evaluation of a particular case of material reutilization by calculating the level of "greenness" i.e., the level of compliance with the principles of green chemistry that was achieved by implementing a green chemistry technology. RESULTS: The results indicate that the greenness level was enhanced by 42% compared to the pre-improvement level, thus demonstrating the economic feasibility of green chemistry. CONCLUSIONS: The assessment technique established in this study will serve as a useful reference for setting the direction of industry-level and government-level technological R&D and for evaluating newly developed technologies, which can greatly contribute toward gaining a competitive advantage in the global market.

Priority survey between indicators and analytic hierarchy process analysis for green chemistry technology assessment

OBJECTIVES: This study presents the indicators and proxy variables for the quantitative assessment of green chemistry technologies and evaluates the relative importance of each assessment element by consulting experts from the fields of ecology, chemistry, safety, and public health. METHODS: The results collected were subjected to an analytic hierarchy process to obtain the weights of the indicators and the proxy variables. RESULTS: These weights may prove useful in avoiding having to resort to qualitative means in absence of weights between indicators when integrating the results of quantitative assessment by indicator. CONCLUSIONS: This study points to the limitations of current quantitative assessment techniques for green chemistry technologies and seeks to present the future direction for quantitative assessment of green chemistry technologies.

Priority survey between indicators and analytic hierarchy process analysis for green chemistry technology assessment

OBJECTIVES: This study presents the indicators and proxy variables for the quantitative assessment of green chemistry technologies and evaluates the relative importance of each assessment element by consulting experts from the fields of ecology, chemistry, safety, and public health. METHODS: The results collected were subjected to an analytic hierarchy process to obtain the weights of the indicators and the proxy variables. RESULTS: These weights may prove useful in avoiding having to resort to qualitative means in absence of weights between indicators when integrating the results of quantitative assessment by indicator. CONCLUSIONS: This study points to the limitations of current quantitative assessment techniques for green chemistry technologies and seeks to present the future direction for quantitative assessment of green chemistry technologies.

Study on the biodegradation of alternatives (four species including C8H8F9KO3S) for perfluorooctane sulfonate

OBJECTIVES: The objective of this study was to evaluate the biodegradation potential of four perfluorooctane sulfonic acid (PFOS) alternatives that were developed at Changwon National University. While PFOS has been used widely in industrial and consumer products, it is known to be a persistent organic pollutant. Therefore, greener alternatives are highly desirable. METHODS: Biodegradation tests were run for 28 days using standard test protocols. The biochemical oxygen demand was measured daily throughout the experimental period, and the data were used to calculate the biodegradation rates. Microorganisms were isolated from the some of the tests that showed evidence of biodegradation. RESULTS: C8H8F9KO3S, which has the same number of carbons as the parent compound PFOS but a reduced number of fluorines, showed the highest biodegradation rate followed by C10H8F13KO3S. Chemical alternatives with lower number of carbons did not biodegrade readily in the experiments. CONCLUSIONS: Together, these results suggest that it may be advantageous to develop PFOS alternatives with 8 carbons, the same as PFOS, but a reduced number of fluorines; as such, chemicals are more susceptible to biodegradation than the parent compound.