Publications by authors named "I Rangelov"

The fourth industrial revolution extensively reshapes the reality we are living in by blurring the boundaries of physical, digital and biological worlds. A good example is the previously unthinkable incursion of nanoscale waste materials, such as soot, into the technologies for assisted reproduction. Although the rapeseed oil soot may efficiently enhance the progressive motility of human spermatozoa, it is yet unknown whether this material induces undesirable oxidative stress and premature acrosome reaction, endangering the sperm-oocyte fusion and blastocyst formation.

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Obtaining spermatozoa with progressive motility, via postejaculatory activation with pharmacological agents such as theophylline and pentoxifylline, is crucial for the success rate of assisted reproduction in couples with severe male factor infertility. Regrettably, the possibility of premature acrosome reactions and impared oocyte function questions the practical applicability of phosphodiesterase inhibitors. The rapid development of nanotechnologies promotes the use of hydrophobic rapeseed oil soot as a non-cytotoxic biomaterial for sperm motility activation, but the scarcity of knowledge regarding the interactions of soot with components from the seminal plasma hinders the eventual commercialization of this cutting-edge approach.

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Sperm cryopreservation is vital in combating the human infertility, but regrettably, the toxicity of cryoprotectants and the occurrence of intracellular icing, osmotic shocks or shrinkage of the cells below a given threshold volume greatly affects the success rate of this technique. Using the virtue of nanotechnologies and depositing water-repellent soot nanoparticles on the inner walls of cryovials may outline new directions in the development of cryobiology, but doubts related to the soot's venomosity question its practical implementability. The scientific content of this article eliminates the existing apprehensions by analyzing the cytotoxicity of three types of rapeseed oil soot, differing in morphology, surface chemistry and zeta potential, towards human spermatozoa.

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Purpose: The aim of this study was to compare the levels of hyperglycosylated human chorionic gonadotropin (hCG-H) secreted from balanced and unbalanced human embryos.

Methods: Single-step culture media samples from 155 good quality embryos, derived from 90 good prognosis patients undergoing intracytoplasmic sperm injection (ICSI), were collected on the fifth day of embryo cultivation. All embryos were tested by next-generation sequencing (NGS) technique.

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Objective: Deleterious effects of free radicals do not only result from the amount of free radicals produced but also are related to the efficiency and to the activities of enzymatic antioxidant systems. We investigated the effect of exogenous superoxide dismutase (SOD1) or Cu-chelating agent diethyldithiocarbamate (DDC) on the apoptosis (caspase-3 activity) of human granulosa luteinized cells (hGLC) in vitro.

Methods: The effects of SOD1 and DDC were studied using in vitro culture system, caspase-3 and the total SOD activity in hGLCs were measured using AcDEVD-PNA substrate and Beaushap and Fridovich methods, respectively, after 48 h of the culture period.

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