The efficient role of sodium alginate-based biodegradable dressings for skin wound healing application: a systematic review.

Injuries and damage to the skin can be caused by different reasons throughout human life. The use of sodium alginate in tissue dressing has been highly studied due to its intrinsic properties, including its degradation rate and biocompatibility, and the capacity of supporting tissue proliferation. The aim of this paper is to demonstrate evidences, through a systematic review method, to support the application of sodium alginate as a curative and as a potential accelerator in the healing of skin wounds. Four databases were used to develop this systematic review: Science Direct, PubMed, Scielo and Scopus. The time interval established for the search was from January 2016 to October 2023. After applying the exclusion and inclusion criteria, each selected article was evaluated and it was observed that the improvement of the mechanical properties of sodium alginate when correctly processed and crosslinked were evident. However, the increase of crosslinking affects as the wettability and the swelling of the biomaterials can cause limitations in mechanical properties and hidrophilic behavior. To achieve the ideal dressing, it is necessary to apply the optimal concentration of crosslinking and other substances, which can damage its hidrophilic characteristic. Thus, it was concluded that sodium alginate has every caracteristic desirable to develop an effective and safe dressing.

Chemical synthesis and in vitro biocompatibility tests of poly (L-lactic acid).

Polylactic acid is a polymer of great technological interest, whose excellent mechanical properties, thermal plasticity, and bioresorbability render it potentially useful for environmental applications, as a biodegradable plastic and as a biocompatible material in biomedicine. This article discusses the synthesis and characterization of poly-L-lactic acid, obtained through two synthetic routes: direct polycondensation reactions without organic solvents, and in a supercritical medium. Tin complexes were used as catalysts in both polymerization reactions. The polymers were characterized by (1)HNMR, IR, GPC, DSC, and TGA techniques. In vitro biocompatibility tests were performed with human alveolar bone osteoblasts and there were assessed cell adhesion, proliferation and viability. The poly condensation reaction proved to be an excellent synthetic route to produce PLA polymers with different molar mass. The formation of polymers from lactic acid monomer was confirmed through techniques utilized. It was observed that cell adhesion and viability was not disturbed by the presence of the polymer, although the proliferation rate was decreased when compared to control.

Paradigmas das práticas de gestão ambiental no segmento de produção de refeições no Brasil / Paradigms of environmental management practices in the meal production sector in Brazil

RESUMO Os processos relacionados com a produção de refeições para os consumidores são causadores de impactos para o meio ambiente. Este trabalho teve como objetivo identificar quais são as práticas de restaurantes brasileiros relacionadas com a temática da gestão ambiental e da sustentabilidade. Trata-se de um estudo de revisão sistemática de publicações no período de 2000 a 2015. Entre os resultados encontrados, destacam-se a geração de resíduos de alimentos no processo de produção e consumo das refeições, além de investigações sobre acondicionamento, reciclagem e destinação desses resíduos. São apresentadas também as temáticas de utilização de recursos (água e energia) e um panorama sobre a avaliação dos aspectos ambientais por meio da prática de certificação de restaurantes comerciais com selos de sustentabilidade. Estudos avaliativos dessa natureza são importantes para contribuir para o diagnóstico da realidade no segmento de produção de refeições e também para fomentar investigações futuras que apontem para a redução dos impactos ambientais nessa atividade.

ABSTRACT The processes related to the production of meals for consumers cause impacts on the environment. The objective of this study is to identify the practices of Brazilian restaurants regarding to environmental management and sustainability. This is a systematic study reviewing publications from 2000 to 2015. Among the findings, the generation of food waste in the process of production and consumption of food can be highlighted, as well as investigations on packaging, recycling and residues disposal. It also presents the themes of resources using (water and energy) and an overview of the evaluation of environmental aspects through the practice of certifying commercial restaurants with sustainability seals. Evaluative studies of this nature are important to contribute to the diagnosis of reality in meal production segment and also to promote further investigations that show the reduction of environmental impacts on this activity.

Human alveolar bone-derived cell-culture behaviour on biodegradable poly(L-lactic Acid).

Poly(L-lactic acid) (PLA) is a polymer of great technological interest, whose excellent mechanical properties, thermal plasticity and bioresorbability render it potentially useful for environmental applications, as a biodegradable plastic and as a biocompatible material in biomedicine. The interactions between an implant material surface and host cells play central roles in the integration, biological performance and clinical success of implanted biomedical devices. Osteoblasts from human alveolar bone were chosen to investigate the cell behaviour when in contact with PLA discs. Cell morphology and adhesion through osteopontin (OPN) and fibronectin (FN) expression were evaluated in the initial osteogenesis, as well as cell proliferation, alkaline phosphatase activity and bone nodule formation. It was shown that the polymer favoured cell attachment. Cell proliferation increased until 21 days but in a smaller rate when compared to the control group. On the other hand, ALP activity and bone mineralization were not enhanced by the polymer. It is suggested that this polymer favours cell adhesion in the early osteogenesis in vitro, but it does not enhance differentiation and mineralization.