Improving DNA nanostructure stability: A review of the biomedical applications and approaches.

DNA's programmable, predictable, and precise self-assembly properties enable structural DNA nanotechnology. DNA nanostructures have a wide range of applications in drug delivery, bioimaging, biosensing, and theranostics. However, physiological conditions, including low cationic ions and the presence of nucleases in biological systems, can limit the efficacy of DNA nanostructures. Several strategies for stabilizing DNA nanostructures have been developed, including i) coating them with biomolecules or polymers, ii) chemical cross-linking of the DNA strands, and iii) modifications of the nucleotides and nucleic acids backbone. These methods significantly enhance the structural stability of DNA nanostructures and thus enable in vivo and in vitro applications. This study reviews the present perspective on the distinctive properties of the DNA molecule and explains various DNA nanostructures, their advantages, and their disadvantages. We provide a brief overview of the biomedical applications of DNA nanostructures and comprehensively discuss possible approaches to improve their biostability. Finally, the shortcomings and challenges of the current biostability approaches are examined.

Comparison of serum level of some trace elements and vitamin D between patients with premenstrual syndrome and normal controls: A cross-sectional study.

BACKGROUND: Premenstrual syndrome (PMS) is a common problem among women and is identified by reversal emotional, psychological, and physical signs during the luteal phase. These signs, however, lower down in the follicular phase. The cause of PMS isn't very well-known up to nowControl group and many researchers have suggested that mineral compounds and vitamins can inhibit these symptoms. OBJECTIVE: The objective of this study is to compare the serum level of some trace elements and vitamin D between normal controls and patients with PMS. MATERIALS AND METHODS: 300 female students (19-21 yr old) from Falavarjan County were randomly selected and asked to complete a standard questionnaire on PMS during three menstruation cycles. The students were divided into two groups: healthy persons (control) and PMS persons, and PMS was determined on the basis of the answers to the questionnaire. Thereafter, the serum concentrations of zinc, iron, calcium, magnesium, potassium, sodium, and Vitamin D3 were measured and compared between the two groups. RESULTS: Our results showed that the PMS prevalence was about 41.5%. The level of vitamin D decreased in both the control and PMS groups, with a significantly lower range of vitamin D (p ≤ 0.05) in the PMS group. Other factors had no significant change between the two groups. CONCLUSION: Vitamin D deficiency was probably one of the most important causes of unpleasant symptoms of PMS between these students.

Zeta method: A noninvasive method based on membrane charge for selecting spermatozoa expressing high level of phospholipaseCζ.

Intracytoplasmic sperm injection (ICSI) is a technique developed to help attain successful fertilisation for couples with severe male factor. However, a small percentage of couples confront low or failed fertilisation, mainly due to failed oocyte activation. Several studies have introduced phospholipase Cζ (PLCζ) as the main sperm factor inducing oocyte activation and thereby has the potential to act as a biomarker for the prediction of ICSI fertilisation outcome. On the other hand, researchers have focused on novel sperm selection procedures based on cellular characteristics of spermatozoa such as surface electrical charge (Zeta potential) to isolate normal sperm subpopulation with intact chromatin. Therefore, we aimed to compare PLCζ between Zeta method and routine sperm preparation procedure: density gradient centrifugation (DGC). Our results showed that number of PLCζ-positive spermatozoa was significantly low in the Zeta method, but the intensity of PLCζ protein in such spermatozoa was significantly higher than DGC procedure. Therefore, the combination of DGC with Zeta procedure may allow selecting the population of spermatozoa with a high percentage of PLCζ which may also contain a high amount of PLCζ and with intact chromatin. This sperm selection procedure can open a new approach for infertile men with previously failed fertilisation.

Clinical outcomes of magnetic activated sperm sorting in infertile men candidate for ICSI.

Magnetic activated cell sorting (MACS) with annexin V microbeads deselected apoptotic sperm with externalized phosphatidylserine (PS) residues on their surface and decrease chance of such sperm to be inseminated. Therefore, the aim of this study was to evaluate efficiency of MACS procedure in a prospective randomized trial. Sixty-two semen samples were allocated into two groups and processed according to: (i) a combination of MACS with density gradient centrifugation (MACS-DGC) as study group (N = 29); and (ii) DGC alone as a control group (N = 33). Fertilization, embryo quality, pregnancy and implantation rates were compared between the two groups. Although, no significant difference was observed in fertilization rates between the two groups, the percentage of high-quality embryos, pregnancy and implantation rates was significantly higher in the MACS-DGC group compared to DGC alone. Therefore, MACS may help to select the most fertile sperm and improve clinical outcomes of intra-cytoplasmic sperm injection (ICSI).

Effects of branched-chain amino acid supplementation and/or aerobic exercise on mouse sperm quality and testosterone production.

Individuals who regularly exercise utilise dietary supplements to enhance their exercise routine and to increase lean mass. Branched-chain amino acids (BCAAs) are a popular supplement and have been shown to produce a number of beneficial effects in rodent and human models. Therefore, in the present study, the effect of exercise and/or BCAA on sperm parameters and testes tissue was assessed. C57BL6 male mice were divided to six groups; Control, Exercise (Exc), BCAA (consumes 20 mg BCAAs), BCAA+ (consumes 60 mg BCAAs), BCAA/Exc (consumes 20 mg BCAAs during aerobic training) and BCAA+/Exc (consumes 60 mg BCAAs during aerobic training). After 8 weeks of exercise and oral treatment with BCAA; testes and epididymides were dissected, and sperm function and plasma testosterone were assessed. Exercise significantly improved sperm motility and plasma testosterone in Exercise groups with or without BCAA. Percentage of sperm lipid peroxidation was significantly decreased in Exercise group, while intensity of lipid peroxidation at the same group has significantly increased. Epithelium diameters, meiotic index and Johnson' grade did not show any changes between groups. Unlike intensive exercise, endurance exercise along with modest supplementation of BCAAs, but not an overdose, may have some synergic effect on sperm function and testosterone production.

Effects of assisted oocyte activation with calcium- ionophore and strontium chloride on in vitro ICSI outcomes.

OBJECTIVES: Failed fertilization after intra-cytoplasmic sperm injection (ICSI) is mainly attributed to failed oocyte activation and can be overcome by artificial oocyte activation (AOA). The present study aims to compare in vitro outcomes of ICSI following two different assisted oocyte activation chemical procedures (SrCl2 and Ionomycin) in sibling oocytes of ICSI candidates. MATERIALS AND METHODS: From March 2015 until February 2016, 105 infertile men with 99-100% abnormal sperm morphology, irrespective of sperm motility, concentration, or origin (semen or testicular) were included in this study. Out of these, 66 couples accepted to be included in the study group (Ionomycin/ SrCl2) and 39 couples requested routine AOA procedure (Ionomycin) as external control group. Primary outcomes of this study (fertilization, embryo quality, and post-implantation development) were compared between these groups. RESULTS: Significantly higher oocyte activation (67.90±3.6% vs. 51.16±3.6%, P=0.004) and fertilization (65.23±3.63% vs. 49.65±3.63%, P=0.008) rates were observed in sibling oocytes treated with Ionomycin in comparison to the SrCl2 sibling group. Percentage of top quality embryos was insignificantly higher in SrCl2 groups compared to the Ionomycin group (29.90±4.27 vs. 20.65±4.05%, P=0.26). CONCLUSION: Ionomycin may be superior to SrCl2 for inducing oocyte activation. However, SrCl2 may be a more efficient means to support the development of better quality embryos following ICSI.

Lentiviral vector-mediated transduction of goat undifferentiated spermatogonia.

Recent studies show that spermatogonial stem cells (SSCs) are able to colonize and form mature spermatozoa following transplantation into germ cell depleted testes of recipient males. Therefore, efficient ways for enrichment and gene transfer into SSCs provides a powerful tool for production of transgenic animals. In order to adapt the technique to goats, three issues were addressed: (i) enrichment of the undifferentiated spermatogonia including SSCs using magnetic activated cell sorting (MACS), (ii) lentiviral vector-mediated transduction of an enhanced green fluorescent protein (EGFP) transgene into enriched cells, and (iii) transplantation of transduced undifferentiated spermatogonia into the germ cell depleted testes of immune-suppressed mice to assess for migration and colony formation ability. Enriched cells were transduced by lentiviral vectors and subsequently analyzed for expression of THY1, PLZF, VASA, UCHL1 and BCL6B genes. Cells were also analyzed for GFP and PLZF by flow cytometry. Enriched transduced cells were transplanted into germ cell depleted mice testis. Quantitative analysis of transcripts revealed that MACS-enrichment significantly increased the expression of SSC-characteristic genes THY1, PLZF, VASA, UCHL1 and BCL6B compared to non-enriched population (P≤0.05). EGFP transduction did not affect the expression levels of SSC-characteristic genes. Flow cytometry revealed that 72% of transduced-enriched cells were positive for EGFP. Finally, transduced-enriched goat SSCs could colonize within the cells into the seminiferous tubules of germ cell depleted recipient mice at higher frequency than non-enriched cells. The results indicated that enrichment of goat undifferentiated spermatogonia by magnetic-activated cell sorting for THY1 antibody combined with lentiviral vector-mediated transduction has the potential to be used for production of transgenic goats.

Evaluation of heat-shock protein A2 (HSPA2) in male rats before and after varicocele induction.

Varicocele is a major cause of infertility and may impair spermatogenesis. This study evaluated the molecular consequences of varicocele on the induction of heat-shock proteins, intracellular chaperones involved in stress responses, and of the ubiquitin-proteasome system, which is participates in the removal of defective sperm in the testis and epididymis. Wistar rats were randomly divided into three groups: surgically induced left varicocele, sham-operated, and untreated controls. Two months after surgery, we observed significantly reduced sperm parameters, DNA integrity, and protamine content in the sperm retrieved from the left epididymis compared to the right epididymis in the varicocele group, as well as compared to sperm retrieved from the left epididymis of the sham and control groups. According to Western blot analysis, we observed significantly higher HSPA2 expression in testicular tissue from the left testis compared to the right testis in the varicocele group or the left testis of the control group. Immunohistochemical analysis showed that expression of HSPA2 was higher in the round spermatid and sperm from the left varicocele compared to the control group. There was normally less HSPA2 expressed in the caput and corpus compared to the cauda of the epididymis in the control group, but this pattern was altered in the caput epididymis of the varicocele group. Levels of ubiquitination were also remarkably lower in the left testis of the varicocele group. Therefore, varicocele impacts expression of HSPA2 and ubiquitination.

Angiotensin Type-1 Receptor Blockade May Not Protect Kidney against Cisplatin-Induced Nephrotoxicity in Rats.

Background. Cisplatin (CDDP) is an anticancer drug, which is accompanied with major side effects including nephrotoxicity. We tested two doses of losartan (10 and 20 mg/kg/day) against nephrotoxicity in a rat model treated with daily administration of CDDP (2.5 mg/kg/day). Methods. Five groups of rats were examined. Groups 1 and 2 received losartan 10 and 20 mg/kg/day, i.p, for a period of 10 days. Group 3 received saline for 10 days, but from day 3 the animals received CDDP (2.5 mg/kg/day, i.p) for the next seven days. Groups 4 and 5 received treatment regimen the same as groups 1 and 2, but from day 3 they also received CDDP for the next seven days. At the end of the experiment, blood samples were obtained and the kidneys were removed to undergo pathological investigation and to obtain supernatant from homogenized tissue. Results. CDDP induced nephrotoxicity, but the serum levels of creatinine and blood urea nitrogen were not attenuated by losartan. The pathological findings confirmed that losartan did not have nephroprotective effect in this experimental model. Conclusion. According to the findings, losartan could not improve renal function impaired by toxicity induced by continuous doses of CDDP, and also it worsened the renal failure.

Effects of Fennel Essential Oil on Cisplatin-induced Nephrotoxicity in Ovariectomized Rats.

BACKGROUND: Cisplatin (cis-diamminedichloroplatinum II (CDDP)) is an effective drug in cancer therapy to treat solid tumors. However, the drug is accompanied by nephrotoxicity. Previous reports indicated that estrogen has no protective role against CDDP-induced nephrotoxicity, but the role of phytoestrogen as an estrogenic agent in plants is not determined yet. The major composition of fennel essential oil (FEO) is trans-anethole that has estrogenic activity; so, we used FEO as a phytoestrogen source against CDDP-induced nephrotoxicity. MATERIALS AND METHODS: Fifty-four ovariectomized Wistar rats were divided into seven groups. Groups 1-3 received different doses of FEO (250, 500, and 1000 mg/kg/day, respectively) for 10 days. Group 4 received saline for 10 days plus single dose of CDDP (7 mg/kg, intraperitoneally (ip)) at day 3. Groups 5-7 received FEO similar to groups 1-3, respectively; plus a single dose of CDDP (7 mg/kg, ip) on day 3. On day 10, the animals were sacrificed for histopathological studies. RESULTS: The serum levels of blood urea nitrogen (BUN) and creatinine (Cr), kidney tissue damage score (KTDS), and kidney weight (KW) and body weight changes in CDDP-treated groups increased significantly (P < 0.05). FEO did not reduce the levels of BUN and Cr, KTDS, and KW and body weight changes. Also, the serum and tissue levels of nitrite were not altered significantly by FEO. CONCLUSION: FEO, as a source of phytoestrogen, did not induce kidney damage. In addition, FEO similar to estrogen was not a nephroprotectant agent against CDDP-induced nephrotoxicity.

THY1 as a reliable marker for enrichment of undifferentiated spermatogonia in the goat.

Spermatogonial stem cells are unique cells of testes that can restore fertility upon transplantation into recipient testes. However, use of suitable markers for enrichment of these cells have important potential application. THY1, is an established conserved marker of spermatogonial stem cells in bovine, rodents, and primates, but there is no information available in goats. After three rounds of enzymatic digestion of prepubertal goat testicular tissues, undifferentiated spermatogonia positive for THY1 were isolated by magnetic-activated cell sorting and were used for immunocytochemistry, real-time polymerase chain reaction analysis for gene expression, protein expression, and transplantation into recipient mice. Immunocytochemical analyses showed that significantly higher percentage of THY1(+) cells were positive for PLZF and VASA when compared with unselected population. This result for PLZF was further confirmed at the protein level. Real-time polymerase chain reaction analysis revealed that expression of THY1, PLZF, VASA, BCL6B, and UCHL1 as SCCs characteristic genes in THY1(+) cells was significantly higher than in the initial population. Finally, transplantation of PKH26-labeled cells revealed that THY1(+) cells had higher capacity for colony formation when compared with unselected cells. In conclusion, the results provide indications that THY1 surface marker can be reliably used for enrichment of undifferentiated spermatogonial in the goats.

Vitamin e is a nephroprotectant agent in male but not in female in a model of Cisplatin-induced nephrotoxicity.

Background. The role of gender for nephroprotectant agent such as vitamin E in cisplatin- (CP-) induced nephrotoxicity has not been documented yet. Methods. One group from each gender of Wistar rats received a single dose of CP (7 mg/kg; i.p) and was treated with vitamin E (1 g/kg/day) for 7 days, and they were compared with similar gender in the control group. Results. The serum levels of blood urea nitrogen (BUN) and creatinine (Cr) in male animals treated with CP was not different from the control group, but it was significantly different in the female rats (P < 0.05). The CP-induced damage intensity in male kidney tissue was not significantly different between the CP-treated and control groups, but this was not the case in female, indicating that the tissue damage in female is significantly different from the control group (P < 0.05). No significant difference in serum levels of magnesium (Mg), nitrite, malondialdehyde (MDA), and lactate dehydrogenase (LDH) was seen between the genders. Kidney weight and body weight changes were statistically significant in both genders (P < 0.05). Significant difference was observed in uterus weight between the two groups of female (P < 0.05). Conclusion. Vitamin E may prevent CP-induced nephrotoxicity in male, but possibly it has not such nephroprotectant effect in female.