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Anthropogenic actions can result in environmental damage when they disrespect sustainability principles. The use of synthetic chemical substances as pesticides, the large presence of pharmaceuticals and personal care products in wastewaters, industrial activities using dyes or other organic compounds that can persist for a long time in nature are some examples of concerning sources of a group of pollutants called xenobiotics. This is a global problem that threatens the survival of various forms of life on the planet, including humans, and consequently from the ecosystem as a whole. This chapter will address specifically the concerns and threats related to the pollution of aquatic ecosystems by xenobiotics, highlighting the pesticides and pharmaceuticals.

Multiwalled carbon nanotubes (MWCNTs), nanographene oxide (NGO), and gold nanorods (NRs) can be functionalized and complexed to DNA to promote efficient gene delivery to Nile tilapia spermatogonial stem cells inducing less cell death than electroporation and the commercial reagents tested. Therefore, nanomaterials can contribute to achieve fish transgenesis.

Nanodiamonds (NDs), multiwalled carbon nanotubes (MWCNTs) and gold nanorods (NRs) can be functionalized to promote gene delivery to hard-to-transfect cells with higher transfection efficiency than cationic lipids, and inducing less cell death.

Carboxi-functionalized multiwall carbon nanotubes (fMWCNTs), when complexed with DNA, can promote gene delivery to Nile tilapia spermatogonial stem cells with higher transfection efficiency than cationic lipids or electroporation, causing also less cell death.

Cell proliferation is orchestrated through diverse proteins related to calcium (Ca(2+)) signaling inside the cell. Cellular Ca(2+) influx that occurs first by various mechanisms at the plasma membrane, is then followed by absorption of Ca(2+) ions by mitochondria and endoplasmic reticulum, and, finally, there is a connection of calcium stores to the nucleus. Experimental evidence indicates that the fluctuation of Ca(2+) from the endoplasmic reticulum provides a pivotal and physiological role for cell proliferation. Ca(2+) depletion in the endoplasmatic reticulum triggers Ca(2+) influx across the plasma membrane in an phenomenon called store-operated calcium entries (SOCEs). SOCE is activated through a complex interplay between a Ca(2+) sensor, denominated STIM, localized in the endoplasmic reticulum and a Ca(2+) channel at the cell membrane, denominated Orai. The interplay between STIM and Orai proteins with cell membrane receptors and their role in cell proliferation is discussed in this review.

Male germline stem cells (MGSCs) are important cells to study because they possess a unique ability to transmit genetic information to offspring, through sperm generation. In the present study, we aimed to investigate the efficiency of gene delivery to Nile tilapia’s MGSCs using different plasmidial DNA delivery strategies. Nile tilapia’s MGSCs were obtained in DMEM/F12 supplemented medium after testicular enzymatic dissociation, density gradient centrifugation and differential plating. The plasmidial DNA used was the pAmCyan (Clontech). The delivery to the cells was performed by using Lipofectamine® 2000 (Life Technologies), electroporation (225V and 50 µF) and carboxylated multiwall carbon nanotubes (fMWCNTs). After transfection, MGSC’s viability was determined using the Annexin-V-Fluos Staining kit (Roche). The cyan fluorescent protein’s (CFP) expression was accessed through fluorescent microscopy, 24 hours after the delivery and cells’ incubation at 28oC and 5% CO2. Through RT-PCR and q-PCR the transgene and β-actin’s mRNA production were compared as indicative of the MGSCs’ capacity of expressing the CFP gene. Twenty-four hours after transfection, we observed expression of the cyan fluorescent protein in cultured MGSCs transfected through all delivery strategies tested. When it comes to the cytotoxicity induced by these different plasmidial DNA delivery strategies, the

In recent years, significant progress has been made in organ transplantation, surgical reconstruction, and the use of artificial prostheses to treat the loss or failure of an organ or bone tissue. In recent years, considerable attention has been given to carbon nanotubes and collagen composite materials and their applications in the field of tissue engineering due to their minimal foreign-body reactions, an intrinsic antibacterial nature, biocompatibility, biodegradability, and the ability to be molded into various geometries and forms such as porous structures, suitable for cell ingrowth, proliferation, and differentiation. Recently, grafted collagen and some other natural and synthetic polymers with carbon nanotubes have been incorporated to increase the mechanical strength of these composites. Carbon nanotube composites are thus emerging as potential materials for artificial bone and bone regeneration in tissue engineering.