Development of Biocompatible Digital Light Processing Resins for Additive Manufacturing Using Visible Light-Induced RAFT Polymerization.

Patients with bone diseases often experience increased bone fragility. When bone injuries exceed the body's natural healing capacity, they become significant obstacles. The global rise in the aging population and the escalating obesity pandemic are anticipated to lead to a notable increase in acute bone injuries in the coming years. Our research developed a novel DLP resin for 3D printing, utilizing poly(ethylene glycol diacrylate) (PEGDA) and various monomers through the PET-RAFT polymerization method. To enhance the performance of bone scaffolds, triply periodic minimal surfaces (TPMS) were incorporated into the printed structure, promoting porosity and pore interconnectivity without reducing the mechanical resistance of the printed piece. The gyroid TPMS structure was the one that showed the highest mechanical resistance (0.94 ± 0.117 and 1.66 ± 0.240 MPa) for both variants of resin composition. Additionally, bioactive particles were introduced to enhance the material's biocompatibility, showcasing the potential for incorporating active compounds for specific applications. The inclusion of bioceramic particles produces an increase of 13% in bioactivity signal for osteogenic differentiation (alkaline phosphatase essay) compared to that of control resins. Our findings highlight the substantial improvement in printing precision and resolution achieved by including the photoabsorber, Rose Bengal, in the synthesized resin. This enhancement allows for creating intricately detailed and accurately defined 3D-printed parts. Furthermore, the TPMS gyroid structure significantly enhances the material's mechanical resistance, while including bioactive compounds significantly boosts the polymeric resin's biocompatibility and bioactivity (osteogenic differentiation).

Upwelling intensity modulates the fitness and physiological performance of coastal species: Implications for the aquaculture of the scallop Argopecten purpuratus in the Humboldt Current System.

Understanding how marine species cope with the natural environmental variability of their native habitats will provide significant information about their sensitivity to the potential environmental changes driven by climate change. In particular, marine species inhabiting upwelling ecosystems are experiencing low seawater temperatures, as well as, acidic and low oxygen conditions as a consequence of the nature of the deep upwelled waters. Our study is focused on one of the most important socio-economical resources of the Humboldt Current System (HCS): the scallop Argopecten purpuratus which has been historically subjected to intensive aquaculture in areas influenced by upwelling processes. Here, a long-term field experiment was performed to understand how tolerant and well-locally-adapted is A. purpuratus to upwelling conditions by studying a set of fitness, physiological, and biomineralogical traits. Stronger upwelling generated a minor water column stratification, with lower temperatures, pH, and oxygen conditions. On the contrary, as upwelling weakened, temperature, pH, and oxygen availability increased. Finally, upwelling intensity also determined the number, duration, and intensity of the cooling and de-oxygenation events occurring in A. purpuratus habitat, as well as, the food availability (chlorophyll-a concentration, Chl-a). Physiologically, A. purpuratus was able to cope with stressful environmental conditions imposed by higher upwelling intensities by enhancing its metabolic and calcification rates, as well, producing higher concentrations of the shell organic matter. These physiological changes impacted the total energy budget, which was highly dependent on Chl-a concentration, and revealed important traits trade-offs with significant fitness costs (higher mortalities emerged when longer and more intense upwelling events succeed). Our study increases the knowledge about the physiological performance and tolerance of this important resource to the ocean acidification and ocean-deoxygenation imposed by variable upwelling intensities, as well as, its potential vulnerability under future changing conditions driven by a potential upwelling intensification.

Pro-oxidant and antioxidant response elicited by CH2Cl2, CHCl3 and BrCHCl2 in Goodea gracilis using non-invasive methods.

The development of non-invasive methods aimed to evaluate the effects of many toxicants is required. Although there are some studies conducted in successful ways, a lack of information prevails especially for those substances that could be formed autochthonously in the water bodies, such as halomethanes (HMs). In this study, induction of pro-oxidant forces (CH2O, O2, H2O2), oxidative stress (TBARS, RCO) and antioxidant defenses (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in the skin mucus layer regarding to the liver of Goodea gracilis exposed to CH2Cl2, CHCl3 and BrCHCl2 were evaluated, in addition to the hepatic cytochrome P450 (CYP 2E1) and glutathione S-transferase theta (GSTT) activities. Regardless of the implicit toxicity involved in the bioactivation of the HMs, carried out by the CYP 2E1 and GST, it was noticeable that this process induces oxidative stress. The usefulness of the mucus layer for the evaluation of the oxidative stress response was demonstrated, despite some peculiar characteristics concerning induction of oxidative stress in liver and skin mucous layer. However, for the understanding of the induction of reactive oxygen species in both targets it is essential to evaluate the activity of antioxidant defenses; otherwise the interpretation of toxic effects elicited by HMs would be erroneous. In the skin mucus layer, lower activities of the enzymes involved in antioxidant defense than in liver were observed. The evaluation of the biomarkers in the skin mucus layer involved in the oxidative stress is useful due the consistent response regarding to concentration of the HMs.