Actions to reduce carbon footprint in materials to healthcare buildings.

Building sector is a major contributor to the emissions of pollutant gases, which are responsible for health-damaging effects of climate change. To quantify and reduce these emissions. This comparative study is presented between two buildings that could have a sanitary or any other type of use. Both buildings have similar characteristics, except for their structures, one made of metal and the other of concrete. The design, structural calculation and three-dimensional dimensioning were performed using Building Information Modeling (BIM). The budget and the product carbon footprint study were also carried out, to calculate the level of emissions of each building. The study determined higher emissions for the metal-structured building, with 621.234 tCO2/tmaterial compared to 446.707 tCO2/tmaterial for the concrete building. To reduce these emissions, measures related to the replacement of the previously selected materials, by other materials with lower emission rates and identical functionality were presented, such as the replacement of metal building roof polyurethane, or the composition of cement for the concrete building. Both actions represented a reduction of 84.61% CO2 emissions for metal envelope building and 31.765% for the concrete structure. The results of this work will help to select more sustainable materials to use in the renovation of existing buildings, or in the construction of new buildings. For example, health-related buildings, currently in high demand, given the current pandemic situation caused by COVID-19.

Hydrogels for Bioprinting: A Systematic Review of Hydrogels Synthesis, Bioprinting Parameters, and Bioprinted Structures Behavior.

Nowadays, bioprinting is rapidly evolving and hydrogels are a key component for its success. In this sense, synthesis of hydrogels, as well as bioprinting process, and cross-linking of bioinks represent different challenges for the scientific community. A set of unified criteria and a common framework are missing, so multidisciplinary research teams might not efficiently share the advances and limitations of bioprinting. Although multiple combinations of materials and proportions have been used for several applications, it is still unclear the relationship between good printability of hydrogels and better medical/clinical behavior of bioprinted structures. For this reason, a PRISMA methodology was conducted in this review. Thus, 1,774 papers were retrieved from PUBMED, WOS, and SCOPUS databases. After selection, 118 papers were analyzed to extract information about materials, hydrogel synthesis, bioprinting process, and tests performed on bioprinted structures. The aim of this systematic review is to analyze materials used and their influence on the bioprinting parameters that ultimately generate tridimensional structures. Furthermore, a comparison of mechanical and cellular behavior of those bioprinted structures is presented. Finally, some conclusions and recommendations are exposed to improve reproducibility and facilitate a fair comparison of results.