Protocol for designing and bioprinting multi-layered constructs to reconstruct an endothelial-epithelial 3D model.

3D bioprinting has opened new possibilities and elevated tissue engineering complexity. Here, we present a protocol to design a 3D model with two cell lineage layers (A549 and HUVEC) to recreate multi-cell constructs. We describe the steps for slicing the constructs, handling hydrogels, and detailing the bioprinting setup. These 3D-bioprinted constructs can be adapted to various cell models-from primary cell cultures to commercial cell lines and induced pluripotent stem cells (IPCs)-and applications, including drug screening and disease modeling. For complete details on the use and execution of this protocol, please refer to Cruz et al.1.

A Gelatin Methacrylate-Based Hydrogel as a Potential Bioink for 3D Bioprinting and Neuronal Differentiation.

Neuronal loss is the ultimate pathophysiologic event in central nervous system (CNS) diseases and replacing these neurons is one of the most significant challenges in regenerative medicine. Providing a suitable microenvironment for new neuron engraftment, proliferation, and synapse formation is a primary goal for 3D bioprinting. Among the various biomaterials, gelatin methacrylate (GelMA) stands out due to its Arg-Gly-Asp (RGD) domains, which assure its biocompatibility and degradation under physiological conditions. This work aimed to produce different GelMA-based bioink compositions, verify their mechanical and biological properties, and evaluate their ability to support neurogenesis. We evaluated four different GelMA-based bioink compositions; however, when it came to their biological properties, incorporating extracellular matrix components, such as GeltrexTM, was essential to ensure human neuroprogenitor cell viability. Finally, GeltrexTM: 8% GelMA (1:1) bioink efficiently maintained human neuroprogenitor cell stemness and supported neuronal differentiation. Interestingly, this bioink composition provides a suitable environment for murine astrocytes to de-differentiate into neural stem cells and give rise to MAP2-positive cells.

Panorama das indústrias galvânicas de Juazeiro do Norte, Ceará: com ênfase nos teores de metais-traço nos efluentes e resíduos sólidos / Overview of galvanic industries in Juazeiro do Norte, Brazil: emphasis on trace metal content in effluents and solid waste

RESUMO Os efluentes e resíduos industriais galvânicos são uma preocupação mundial, por terem em sua composição metais-traço altamente tóxicos, prejudiciais ao meio ambiente e à saúde humana. Neste artigo, é apresentado um panorama da indústria de semijoias folheadas de Juazeiro do Norte, Ceará, considerando-se os processos de produção e a concentração de metais-traço nos efluentes, bem como o resíduo sólido galvânico, gerados pelo setor. Dados primários de produção foram obtidos em 11 empresas por meio de questionário técnico. As concentrações de metais-traço foram obtidas por espectrofotometria de absorção atômica de chama. Os resultados demonstraram ineficiência no tratamento dos efluentes para cobre, níquel, cromo, chumbo e zinco. As concentrações médias de metais no resíduo sólido galvânico foram de 239 g Cu kg-1, 99 g Zn kg-1, 23,8 g Ni kg-1, 6,6 g Pb kg-1, 0,2 g Cr kg-1, 1,7 g Cd kg-1, 1,0 g Mn kg-1 e 8,2 g Fe kg-1. Os resultados evidenciaram a necessidade da adoção de medidas para o controle de qualidade dos processos de tratamento dos efluentes, com vistas à sustentabilidade do setor.

ABSTRACT Galvanic industrial effluents and wastes are a worldwide concern, as they contain highly toxic trace metals that are harmful to the environment and human health. This article presents an overview of the clad semi jewelry industry in Juazeiro do Norte, state of Ceará, Brazil, considering the production processes and the concentration of trace metals in the effluents and galvanic sludge waste generated by the sector. Primary production data were obtained from 11 companies by a technical questionnaire. Trace metal concentrations were obtained by flame atomic absorption spectrophotometry. The results showed inefficiency in the treatment of effluents for copper, nickel, chrome, lead, and zinc. The average metal concentrations in the galvanic sludge waste were 239 g Cu kg-1, 99 g Zn kg-1, 23.8 g Ni kg-1, 6.6 g Pb kg-1, 0.2 g Cr kg-1, 1.7 g Cd kg-1, 1.0 g Mn kg-1, and 8.2 g Fe kg-1. The results evidenced the need for adopting measures concerning quality control of the effluent treatment processes aiming at the sustainability of the sector.