Interaction of Copper-Based Nanoparticles to Soil, Terrestrial, and Aquatic Systems: Critical Review of the State of the Science and Future Perspectives

In the past two decades, increased production and usage of metallic nanoparticles (NPs) has inevitably increased their discharge into the different compartments of the environment, which ultimately paved the way for their uptake and accumulation in various trophic levels of the food chain. Due to these issues, several questions have been raised on the usage of NPs in everyday life and has become a matter of public health concern. Among the metallic NPs, Cu-based NPs have gained popularity due to their cost-effectiveness and multifarious promising uses. Several studies in the past represented the phytotoxicity of Cu-based NPs on plants. However, comprehensive knowledge is still lacking. Additionally, the impact of Cu-based NPs on soil organisms such as agriculturally important microbes, fungi, mycorrhiza, nematode, and earthworms are poorly studied. This review article critically analyses the literature data to achieve a more comprehensive knowledge on the toxicological profile of Cu-based NPs and increase our understanding of the effects of Cu-based NPs on aquatic and terrestrial plants as well as on soil microbial communities. The underlying mechanism of biotransformation of Cu-based NPs and the process of their penetration into plants has also been discussed herein. Overall, this review could provide valuable information to design rules and regulations for the safe disposal of Cu-based NPs into a sustainable environment

Bone inductive properties of rhBMP-2 loaded porous calcium phosphate cement implants inserted at an ectopic site in rabbits.

Contains fulltext : 47312.pdf (publisher's version ) (Closed access)Recombinant human bone morphogenetic protein-2 (rhBMP-2) is known for its osteoinductive potential in bone tissue engineering. Calcium phosphate (Ca-P) cements are injectable, osteoconductive ceramic materials in which a macroporous structure can be induced during the setting reaction. In this study, the osteoinductive capability of rhBMP-2 loaded porous Ca-P cement was evaluated. Porous Ca-P cement discs were made and loaded with rhBMP-2 in vitro and implanted subcutaneously in the back of New Zealand white rabbits. The implantation period was either 2 or 10 weeks. Histological analysis of retrieved specimens revealed evident bone formation in the rhBMP-2 loaded Ca-P cement discs (pore fill: 18+/-6%) after 10 weeks of implantation. Bone formation occurred only in rhBMP-2 loaded porous Ca-P cement discs. Degradation of the Ca-P cement could not be confirmed after 10 weeks of implantation. The scaffold maintained its shape and stability during this time period. We conclude that porous Ca-P cement is a suitable carrier material for ectopic bone engineering

Growth factor-loaded scaffolds for bone engineering.

Contains fulltext : 47746.pdf (publisher's version ) (Closed access)The objective of the study presented here was to investigate the bone inductive properties as well as release kinetics of rhTGF-beta1- and rhBMP-2-loaded Ti-fiber mesh and CaP cement scaffolds. Therefore, Ti-fiber mesh and porous CaP cement scaffolds were provided with these growth factors and inserted in subcutaneous and cranial implant locations in rats and rabbits. In vitro, a rapid release of rhTGF-beta1 was observed during the first 2 h of the Ti-fiber mesh scaffolds. During this time, more than 50% of the total dose of rhTGF-beta1 was released. Following this initial peak, a decline in the level of rhTGF-beta1 occurred. After 1 week, the entire theoretical initial dose was observed to have been released. This in contrast to the rhTGF-beta1 and rhBMP-2 release of the porous CaP cement scaffolds. Here, no substantial initial burst release was observed. The scaffolds showed an initial release of about 1% after 1 day, followed by an additional marginal release after 1 week. Histological analysis revealed excellent osteoconductive properties of non-loaded Ca-P material. Inside non-loaded Ti-mesh fiber scaffolds, also bone ingrowth occurred. Quantification of the bone ingrowth showed that bone formation was increased significantly in all scaffold materials by administration of rhTGF-beta1 and rhBMP-2. Consequently, we conclude that the release kinetics of growth factors from porous CaP cement differs from other scaffold materials, like metals and polymers. Nevertheless, orthotopic bone formation in a rabbit cranial defect model was stimulated in rhTGF-beta1- and rhBMP-2-loaded CaP cement and Ti-fiber mesh scaffolds compared with non-loaded implants

Fatores de risco para perda ponderal de crianças frequentadoras de berçários em creches do município de São Paulo Risk factors for ponderal loss of children attending the nurseries of day care centers in São Paulo, Brazil

OBJETIVO: Identificar e quantificar os fatores de risco relacionados ao agravamento da condição nutricional entre o nascimento e a realização deste estudo. MÉTODOS: Estudo transversal com 270 crianças frequentadoras dos berçários de oito creches públicas e filantrópicas do município de São Paulo. Considerou-se com perda ponderal as crianças que apresentaram diferença negativa do escore Z para a relação peso para idade entre o nascimento e a ocasião da realização desse inquérito. No estudo das associações, utilizou-se o teste do qui-quadrado e consideraram-se as variáveis com nível de significância p<0,05. Foi ajustado modelo multivariado de regressão logística com estimativas de razões de chance (Odds Ratio, OR) para o controle de covariáveis ou variáveis de confundimento. RESULTADOS: A análise antropométrica revelou prevalência de desnutrição (P/I <-2 escore Z) de 7,1% no nascimento e de 4,4% na ocasião da medida e evidenciou evolução ponderal em escore Z desfavorável para 50,7% das crianças (n=137). Nas análises bivariadas, as variáveis "peso de nascimento suficiente" (OR=5,35; p<0,001), "anemia" (OR=1,81; p=0,019) e "idade menor que 19 meses" (OR=1,67; p=0,036) alcançaram significância estatística. CONCLUSÕES: A perda ponderal em escore Z ao longo dos primeiros meses de vida é um indicador ainda pouco utilizado em estudos epidemiológicos, mas a realização de outras pesquisas poderá identificá-la como um indicador de risco de vulnerabilidade sociobiológica. Sugere-se a execução de programas de Saúde voltados ao controle da perda ponderal e que enfoquem a população infantil de menor idade e/ou com anemia, de modo a reduzir a prevalência dos agravos nutricionais.<br>OBJECTIVE: To identify and quantify risk factors related to the aggravation of nutritional condition from birth until the date of the study. METHODS: Cross-sectional study with 270 children attending nurseries of eight public and non-for-profit daycare centers in the city of São Paulo, Brazil. Ponderal loss was considered when children presented negative difference of Z score for weight-for-age (W/A) from birth until the date of the present inquiry. Chi-square was used to test associations and considered significant if p<0.05. Multivariate logistic regression model adjusted Odds Ratio estimates for confounding variables and/or covariables. RESULTS: Anthropometric analysis showed 7.1% prevalence of malnutrition (W/A<-2 Z score) at birth and 4.4% by the time of measurement. Ponderal evolution with unfavorable Z score was present in 50.7% of studied children (n=137). In the bivariate analyses, the variables: birth weight (OR=5.35; p<0.001), anemia (OR=1.81; p=0.019) and age less than 19 months (OR=1.67; p=0.036) were statistically significant. CONCLUSIONS: Ponderal loss in Z score during the first months of life has not been often used in epidemiological studies. However, future researches might identify weight loss as an indicator of risk for sociobiological vulnerability. Development of health programs in order to reduce the prevalence of nutritional aggravation targeting the younger population with anemia is strongly recommended