Assessment of Angiogenesis and Cell Survivability of an Inkjet Bioprinted Biological Implant in an Animal Model.

The rapidly growing field of tissue engineering hopes to soon address the shortage of transplantable tissues, allowing for precise control and fabrication that could be made for each specific patient. The protocols currently in place to print large-scale tissues have yet to address the main challenge of nutritional deficiencies in the central areas of the engineered tissue, causing necrosis deep within and rendering it ineffective. Bioprinted microvasculature has been proposed to encourage angiogenesis and facilitate the mobility of oxygen and nutrients throughout the engineered tissue. An implant made via an inkjet printing process containing human microvascular endothelial cells was placed in both B17-SCID and NSG-SGM3 animal models to determine the rate of angiogenesis and degree of cell survival. The implantable tissues were made using a combination of alginate and gelatin type B; all implants were printed via previously published procedures using a modified HP inkjet printer. Histopathological results show a dramatic increase in the average microvasculature formation for mice that received the printed constructs within the implant area when compared to the manual and control implants, indicating inkjet bioprinting technology can be effectively used for vascularization of engineered tissues.

Antioxidant screening and phenolic content of ethanol extracts of selected Baja California Peninsula macroalgae.

The Baja California Peninsula in México has about 670 species of macroalgae along its coast. Species richness increases the probability of finding native macroalgae with potential as sources of bioactive compounds suitable for health, pharmacological, and cosmetic ingredients. To understand the biotechnological value of macroalgae from the peninsula, ethanol extracts from 17 macroalgae (four Chlorophyta, six Rhodophyta, seven Ochrophyta) were screened for antioxidant potential. To determine the antioxidant capacity of macroalgal extracts, 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power, and nitric oxide radical scavenging as well as total phenolic content (TPC) were measured. Extracts of the brown macroalgae were most active. Among these, Eisenia arborea, Padina concrecens, and Cystoseira osmundacea had the highest TPC and exhibited the strongest radical scavenging activities. Correlations were found between TPC macroalgal and scavenging capacity, indicating an important role of polyphenols as antioxidants. This suggests that some brown macroalgae from Baja California Peninsula may be a good source of natural bioactive compounds.

Oxidative stress indicators and chemical contaminants in East Pacific green turtles (Chelonia mydas) inhabiting two foraging coastal lagoons in the Baja California peninsula.

In order to determine the potential effects of contaminants in juveniles of East Pacific green turtle, Chelonia mydas, captured alive, circulating trace metal and organochlorine pesticide concentrations were correlated with body condition, antioxidant enzyme activities and lipid peroxidation levels. Turtles were sampled in Punta Abreojos (PAO) and Bahía Magdalena (BMA). Turtles from PAO showed higher silicon and cadmium concentrations, but lower α-hexachlorocyclohexane, γ-hexachlorocyclohexane, hexachlorobenzene and aldrin concentrations than individuals from BMA. In BMA cadmium concentration decreased as the standard carapace length of the turtles increased. In PAO concentrations of α-hexachlorocyclohexane, heptachlor and hexachlorobenzene were positively correlated with the weight of the individuals. Lipid peroxidation levels were positively correlated with cadmium concentrations. In turtles captured in PAO, enzymatic antioxidant activities correlated mostly with pesticide concentrations, while in individuals from BMA enzyme activities were correlated with trace element concentrations. Correlations between antioxidant enzyme activities and concentration of xenobiotics suggest physiological sensitivity of East Pacific green turtles to chemicals. Regional differences found could be influenced by habitat conditions such as currents, upwellings (PAO) and agricultural activities (BMA). We suggest that, combined, circulating contaminant concentrations, lipid peroxidation levels and antioxidant enzyme activities in sea turtles could be used as biomarkers of the habitat conditions.