Effects of Two Types of Melatonin-Loaded Nanocapsules with Distinct Supramolecular Structures: Polymeric (NC) and Lipid-Core Nanocapsules (LNC) on Bovine Embryo Culture Model

Abstract

Melatonin has been used as a supplement in culture medium to improve the efficiency of in vitro produced mammalian embryos. Through its ability to scavenge toxic oxygen derivatives and regulate cellular mRNA levels for antioxidant enzymes, this molecule has been shown to play a protective role against damage by free radicals, to which in vitro cultured embryos are exposed during early development. In vivo and in vitro studies have been performed showing that the use of nanocapsules as active substances carriers increases stability, bioavailability and biodistribution of drugs, such as melatonin, to the cells and tissues, improving their antioxidant properties. These properties can be modulated through the manipulation of formula composition, especially in relation to the supramolecular structures of the nanocapsule core and the surface area that greatly influences drug release mechanisms in biological environments. This study aimed to evaluate the effects of two types of melatonin-loaded nanocapsules with distinct supramolecular structures, polymeric (NC) and lipid-core (LNC) nanocapsules, on in vitro cultured bovine embryos. Embryonic development, apoptosis, reactive oxygen species (ROS) production, and mRNA levels of genes involved in cell apoptosis, ROS and cell pluripotency were evaluated after supplementation of culture medium with non-encapsulated melatonin (Mel), melatonin-loaded polymeric nanocapsules (Mel-NC) and melatonin-loaded lipid-core nanocapsules (Mel-LNC) at 10−6, 10−9, and 10−12 M drug concentrations. The highest hatching rate was observed in embryos treated with 10−9 M Mel-LNC. When compared to Mel and Mel-NC treatments at the same concentration (10−9 M), Mel-LNC increased embryo cell number, decreased cell apoptosis and ROS levels, down-regulated mRNA levels of BAX, CASP3, and SHC1 genes, and up-regulated mRNA levels of CAT and SOD2 genes. These findings indicate that nanoencapsulation with LNC increases the protective effects of melatonin against oxidative stress and cell apoptosis during in vitro embryo culture in bovine species.

Applications of omics and nanotechnology to improve pig embryo production in vitro

“…However, a growing number of studies have applied nanotechnology in reproductive biology to target and sort specific populations of gametes and to optimize gene transfer and editing methodologies (Barkalina, Charalambous, Jones, & Coward, ; Remião et al, ). In addition, nanoparticulated systems have shown great potential as carriers to deliver molecules into gametes and embryos to improve their developmental competence in vitro (Barkalina, Charalambous, et al, ; Barkalina et al, ; Komninou et al, ; Lucas et al, ; Remião et al, ).…”

“…In addition, nanoencapsulation allowed for the use of lower concentrations of TTN, minimizing the risk of cytotoxic effects related with its use (Lucas et al, ). Similarly, melatonin‐loaded lipid‐core nanocapsules (Mel‐LNC) added during bovine IVM and IVC reduced ROS levels and apoptosis in embryos, increased the cleavage and blastocyst rates, upregulated antioxidant genes, and downregulated proapoptotic genes when compared to nonencapsulated melatonin (Mel) (Komninou et al, ; Remião et al, ). LNCs synthesized by using the Rhodamine B fluorophore–PCL conjugated to label the nanocarrier (Mel‐LNC‐RB) achieved successful delivery into bovine oocytes and remained inside the cells until the blastocyst stage (Remião et al, ).…”

“…However, due to the different chemical and biological composition of supplements, strategies to enable more efficient use of these additives by preventing premature degradation, increasing their bioavailability and facilitating their delivery are desired. Recently, a new approach, based on the use of nanomaterials, has been shown to be a valuable tool for intragamete/embryo delivery of target molecules (Komninou et al, ; Lucas et al, ; Remião et al, ).…”

Melatonin Scavenger Properties against Oxidative and Nitrosative Stress: Impact on <em>In Vitro</em> Embryo Production in Mammals

“…Also, it downregulates BAX, CASP3, and SHC1 genes, and upregulates CAT and SOD2. [82] Mouse Oocyte 10 -7 M during in vitro maturation Improves the blastocyst rate and cell number of blastocysts [83] Mouse Sperm 10 mg/kg body weight for 7 days during cadmium exposure Reduces oxidative stress and inflammation induced by cadmium in male reproductive system [84] Mouse Sperm 0.125 mg/mL in freezing extender during cryopreservation Increases the progressive motility, decreases ROS levels and upregulates BCL-XL [85] Buffalo Oocytes 250 µM during in vitro maturation Improves fertilization rate [86] Bovine Oocytes 1 µM during in vitro maturation of aged oocytes Decreased the aberrant spindle organization, increases ATP production, increases the development of bovine oocytes and reduces apoptotic rate. Also, it downregulates BAX and CASP3 and increases BCL2.…”

Effect of red propolis extract isolated or encapsulated in nanoparticles on the in vitro culture of sheep preantral follicle: Impacts on antrum formation, mitochondrial activity and glutathione levels

“…An innovative way of improving drug solubility and chemical stability, and reducing its toxicity on the in vitro culture is the use of polymeric carrier nanoparticles for substance transportation. Some studies have reported that such nanoparticles containing the antioxidant compounds tretinoin (Lucas et al, ) or melatonin (Komninou et al, ; Remião et al, ) improved bovine embryo quality after in vitro culture. Among synthetic polymers used in the production of nanoparticles, polylactic‐co‐glycolic acid (PLGA) stands out due to its excellent biocompatibility, low toxicity and high capacity to encapsulate drugs (Essa, Rabanel, & Hildgen, ).…”