Metallic nanostructures, especially silver nanoparticles (AgNPs) have already found multiple applications in modern industry, science and medicine. Still, the production of nano-sized compounds often leads to the formation of toxic byproducts and possesses substantial environmental hazard. One of the promising solutions for the ecofriendly creation of nanomaterials predicts the use of a “green chemistry” approach using organisms, their parts or natural compounds to act as safe and effective producers of nanomaterials. Plant-mediated biosynthesis of silver nanoparticles includes the reduction of Ag+ to Ag0 by natural compounds, usually secondary metabolites which can be found in roots, leaves, cortex, fruits, flowers and seeds of various species. Aqueous extract of Capsicum annuum var. cv. (cultivar) Teja (S-17) fruits was used as a bioreducer for the reduction of AgNO3 solution to AgNPs. The formation of the AgNPs was confirmed by the presence of the Tyndall effect of light scattering combined with colour change of the solutions. The properties of the nanoparticles were assessed with UV-visible spectroscopy and scanning electron microscopy. In the present study, we report the experimental optimization of operating parameters needed for silver biotransformation by C. annuum. Biosynthesized nanoparticles were 13–22 nm in size and spherical in shape. Colloidal solutions of AgNPs were also confirmed to show antioxidant activity in vitro as analyzed by the reduction of DPPH radicals. Characterization and application of AgNPs as bactericidal agents on two Gram-positive (Micrococcus luteus, Staphylococcus aureus) and two Gram-negative (Escherichia coli, Pseudomonas aeruginosa) prokaryotic microorganisms demonstrated the prevalent influence on Gram-positive strains.

Розвиток технологій зеленого синтезу створює ефективні інструменти для синтезу наноматеріалів, що забезпечує зменшення негативного впливу хімічних і фізичних методів, а також зниження ризиків нанотехнологій. У статті запропоновано біосинтез наночасток срібла з антибактеріальною активністю проти Micrococcus luteus — опортуністичного збудника, що здатен викликати нозокоміальні інфекції, за допомогою водного екстракту плодів гострого перцю чилі (Capsicum annuum L. ) сорту Теджа. Біосинтезовані наночастинки досліджували за допомогою спектроскопії в УФ та видимій частині спектра, розміри та морфологію наночастинок фіксували методом сканувальної електронної мікроскопії. Встановлено ефективність біосинтезованих наночастинок проти росту і розвитку Micrococcus luteus.

46,XY gonadal dysgenesis (46,XY GD) results from disruptions in the genetic program that governs testicular differentiation during gonadal sex determination, presenting as either complete (46,XY CGD) or partial (46,XY PGD) forms. While monogenic defects account for approximately 50% of cases, recent evidence suggests an oligogenic basis for some 46,XY GD cases. In this study, we investigated a case of 46,XY CGD and performed whole-exome sequencing (WES) on the patient and her parents to explore the genetic basis of the patient’s condition. Although no pathogenic variants were identified in known 46,XY GD-associated genes, we detected rare variants in the STARD9 and CDK5RAP2 genes. Previous study in mice indicate that the orthologues of these genes are highly expressed in Sertoli cells during gonadal sex determination, with Cdk5rap2 playing a critical role in Sertoli cell polarization. Notably, the human STARD9 and CDK5RAP2 proteins interact with each other. Structural analysis suggests that the variants in STARD9 and CDK5RAP2 may alter their protein-protein interactions. Based on these findings, we propose that STARD9 and CDK5RAP2 variants may act together to impair Sertoli cell function, leading to 46,XY CGD, consistent with an oligogenic mode of inheritance. These results suggest that STARD9 and CDK5RAP2 should be considered as candidate genes for 46,XY GD and included in genetic panels for this condition.

46,XY gonadal dysgenesis, characterised by absent or defective testicular development in individuals with a 46,XY karyotype, results from disruptions in the genetic programme governing testis determination and differentiation during embryogenesis. While monogenic causes explain approximately 50% of cases, emerging evidence suggests an oligogenic basis in some patients. However, many cases remain without a definitive molecular diagnosis. In this study, we investigated a patient with 46,XY gonadal dysgenesis to explore the underlying genetic aetiology. Whole-exome sequencing in the patient did not reveal any pathogenic variants in genes previously associated with this condition. Instead, it detected rare variants in STARD9 and CDK5RAP2, which encode centrosomal proteins known to interact with each other. Gene expression analysis of embryonic gonads revealed that STARD9 is sexually dimorphic, with the highest expression in testis-specific Sertoli cells, while CDK5RAP2 is ubiquitously expressed, including in Sertoli cells. These findings suggest a role for both genes in Sertoli cell development, implicating them in the pathogenesis of 46,XY gonadal dysgenesis. To evaluate the functional relevance of the identified variants, we performed molecular dynamics simulations, which suggest that these variants may impair the individual and/or combined functions of STARD9 and CDK5RAP2 proteins. This study is the first to propose a role for STARD9 and CDK5RAP2 genes in human Sertoli cell development and highlights their potential contribution to 46,XY gonadal dysgenesis.