Electrotechnologies are based on the direct application of an external electric field through a given semi-conductive material. These technologies are part of a wide range of biotechnological processes, considered costeffective and environmentally-friendly in view of the less intensive use of non-renewable resources and high levels of energetic efficiency. In this regard, electrotechnologies are a promising processing tool to overcome some of the microalgae's exploitation limitations. The application of electric field-based techniques can cover upstream (i.e. electroporation for genetic transformation, inactivation of culture contaminants, and improvement of growth kinetics) and downstream processes (e.g. harvesting and extraction methods). Pulsed electric fields (PEF) and moderate electric fields (MEF), targeted at microalgae cellular permeabilization and subsequent extraction of valuable compounds, count with a substantial body of fundamental research which puts them on the front row to become mainstream techniques in a near future. This review provides comprehensive knowledge systematization of the current status of the direct application of these techniques on microalgal biotechnology, as wells as future trends and challenges regarding developments in electrotechnologies to be applied to microalgae industrial exploitation.

Breast cancer is the most common type of cancer affecting women. Despite the good prognosis when detected early, significant challenges remain in the treatment of metastatic breast cancer. The recruitment of the vacuolar H+-ATPase (V-H+-ATPase) to the plasma membrane, where it mediates the acidification of the tumor microenvironment (TME), is a recognized feature involved in the acquisition of a metastatic phenotype in breast cancer. Therefore, inhibitors of this pump have emerged as promising anticancer drugs. Lactoferrin (Lf) is a natural pro-apoptotic iron-binding glycoprotein with strong anticancer activity whose mechanism of action is not fully understood. Here, we show that bovine Lf (bLf) preferentially induces apoptosis in the highly metastatic breast cancer cell lines Hs 578T and MDA-MB-231, which display a prominent localisation of V-H+-ATPase at the plasma membrane, but not in the lowly metastatic T-47D or in the non-tumorigenic MCF-10-2A cell lines. We also demonstrate that bLf decreases the extracellular acidification rate and causes intracellular acidification in metastatic breast cancer cells and, much like the well-known proton pump inhibitors concanamycin A and bafilomycin A1, inhibits V-H+-ATPase in sub-cellular fractions. These data further support that bLf targets V-H+-ATPase and explain the selectivity of bLf for cancer cells, especially for highly metastatic breast cancer cells. Altogether, our results pave the way for more rational in vivo studies aiming to explore this natural non-toxic compound for metastatic breast cancer therapy.

Age related neurodegenerative disorders (ARND) are presented as the most debilitating and challenging diseases associated with the central nervous system. Despite the advent of active molecules with a positive role on neurodegenerative mechanisms, many of the current therapeutic strategies remain ineffective in treating or preventing ARND. Lipid nanocarriers have emerged as efficient delivery systems with the capability to cross biological barriers, especially the blood brain barrier (BBB). Also, when associated to natural compounds, lipid nanocarriers have demonstrated to be an interesting alternative to ARND therapies with multiple beneficial effects. This comprehensive review focus on state-of-the-art lipid based nanocarriers for the delivery of natural compounds targeting neurodegeneration. A critical analysis of published reports will be also provided giving indications to researchers about the most promising ARND nanotherapy strategies.

The extraction of the wide range of useful bioactive compounds produced by cyanobacteria is still a major bottleneck at industrial scale. In addition to the high costs, extraction efficiencies are also commonly low, with low cell disruption efficiencies playing a particularly significant role in intracellular compounds' release. To increase the chances of an extended use of the cyanobacteria toxin microcystin in several biotechnological fields, we aimed to optimize five different disruption techniques: bead milling, microwave, freeze-thaw cycles, highspeed homogenization, and sonication. For each of the methods tested, the conditions that maximized the intracellular organic matter release were: i) 20% of beads and treatment time of 7 min (bead milling); ii) 800 W for 1.5 min (microwave); iii) three 12-h freeze-thaw cycles at −20°C; iv) 15,000 rpm for 7 min (high-speed homogenization); and v) 40 kHz for 10 min (sonication). Sonication and freeze-thaw cycles followed by sonication revealed to be the most effective methodologies to ensure a maximum intracellular organic matter release and, consequently, microcystin availability for being extracted. The decrease of cells' viability was however more evident in freeze-thaw cycles, freeze-thaw cycles followed by sonication, and microwave where only 0.3, 0.05 and 0.9% of the initial cells, respectively, maintained their viability after being treated. On the other hand, sonication and bead milling reduced the viability of the original culture to 5 and 15.5%, respectively, while high-speed homogenization did not show any significant differences compared to control. According to the results obtained in this study, the most suitable methodology to maximize the release of microcystin was therefore the use of sonication (40 kHz) during 10 min.

This study has compared the harvesting efficiency of four flocculation methods, namely, induced by pH, FeCl 3 , AlCl 3 and chitosan. No changes were observed on M. aeruginosa cells. Flocculation assays performed at pH 3 and 4 have shown the best harvesting efficiency among the pH-induced tests, reaching values above 90% after 8 h. The adjustment of zeta potential (ZP) to values comprised between − 6.7 and − 20.7 mV enhanced significantly the settling rates using flocculant agents, being FeCl 3 the best example where increments up to 88% of harvesting efficiency were obtained. Although all the four methods tested have presented harvesting efficiencies above 91% within the first 8 h after the optimization process, the highest performance was obtained using 3.75 mg L −1 of FeCl 3 , which allowed reaching 92% in 4 h.