Aptamers are in vitro selected DNA or RNA molecules that are capable of binding a wide range of nucleic and non-nucleic acid molecules with high affinity and specificity. They have been conducted through the process known as SELEX (Systematic Evolution of Ligands by Exponential Enrichment). It serves to reach specificity and considerable affinity to target molecules, including those of viral origin, both proteins and nucleic acids. Properties of aptamers allow detecting virus infected cells or viruses themselves and make them competitive to monoclonal antibodies. Specific aptamers can be used to interfere in each stage of the viral replication cycle and also inhibit its penetration into cells. Many current studies have reported possible application of aptamers as a treatment or diagnostic tool in viral infections, e.g., HIV (Human Immunodeficiency Virus), HBV (Hepatitis B Virus), HCV (Hepatitis C Virus), SARS (Severe Acute Respiratory Syndrome), H5N1 avian influenza and recently spread Ebola. This review presents current developments of using aptamers in the diagnostics and treatment of viral diseases.

The SARS-CoV-2 virus is currently the most serious challenge to global public health. Its emergence has severely disrupted the functioning of health services and the economic and social situation worldwide. Therefore, new diagnostic and therapeutic tools are urgently needed to allow for the early detection of the SARS-CoV-2 virus and appropriate treatment, which is crucial for the effective control of the COVID-19 disease. The ideal solution seems to be the use of aptamers—short fragments of nucleic acids, DNA or RNA—that can bind selected proteins with high specificity and affinity. They can be used in methods that base the reading of the test result on fluorescence phenomena, chemiluminescence, and electrochemical changes. Exploiting the properties of aptamers will enable the introduction of rapid, sensitive, specific, and low-cost tests for the routine diagnosis of SARS-CoV-2. Aptamers are excellent candidates for the development of point-of-care diagnostic devices and are potential therapeutic tools for the treatment of COVID-19. They can effectively block coronavirus activity in multiple fields by binding viral proteins and acting as carriers of therapeutic substances. In this review, we present recent developments in the design of various types of aptasensors to detect and treat the SARS-CoV-2 infection.

The inability to become pregnant for at least 1 year despite regular unprotected intercourse may indicate infertility of one or both partners. This problem affects approximately 10–20% of couples worldwide, regardless of race, with male infertility reported to account for 25–60% of cases. Among the most common pathological causes of male infertility is the presence of varicocele and chronic infections of the male reproductive system. This study was performed using data collected at the Genesis Infertility Treatment Clinic, Bydgoszcz, Poland, between 1 January 2015 and 30 June 2017. A total of 163 men meeting the inclusion criteria were selected and divided into the idiopathic infertility group (78 men) and varicocele-related infertility group (85 men). All patients received treatment with a male fertility supplement containing a combination of 1725 mg of L-carnitine fumarate, 500 mg of acetyl-L-carnitine, 90 mg of vitamin C, 20 mg of coenzyme Q10, 10 mg of zinc, 200 µg of folic acid, 50 µg of selenium, and 1.5 µg of vitamin B12 (Proxeed^® Plus, Sigma-Tau, Italy) twice a day for a period of 6 months from the time of the diagnosis of infertility. The treatment resulted in significant improvements in general semen parameters, particularly sperm count, sperm concentration, total motility, and progressive motility. This antioxidant therapy produced a particularly marked therapeutic benefit in patients with Grade III varicocele, with a greater improvement in progressive motility than in men with less severe or no varicocele. The use of the antioxidant preparation examined here seems reasonable in men with idiopathic infertility and as an adjuvant in those with varicocele-related infertility in whom surgical treatment has resulted in no improvement. Its use should be considered particularly in patients with Grade III varicocele who do not wish to undergo surgical treatment or in whom such a treatment is not possible for various reasons.

Aptamers are short fragments of nucleic acids, DNA or RNA that have the ability to bind selected proteins with high specificity and affinity. These properties allow them to be used as an element of biosensors for the detection of specific proteins, including viral ones, which makes it possible to design valuable diagnostic tools. The influenza virus causes a huge number of human and animal deaths worldwide every year, and contributes to remarkable economic losses. In addition, in 2020, a new threat appeared—the SARS-Cov-2 pandemic. Both disease entities, especially in the initial stage of infection, are almost identical in terms of signs and symptoms. Therefore, a diagnostic solution is needed that will allow distinguishing between both pathogens, with high sensitivity and specificity; it should be cheap, quick and possible to use in the field, for example, in a doctor’s office. All the mentioned properties are met by aptasensors in which the detection elements are specific aptamers. We present here the latest developments in the construction of various types of aptasensors for the detection of influenza virus. Aptasensor operation is based on the measurement of changes in electric impedance, fluorescence or electric signal (impedimetric, fluorescence and electrochemical aptasensors, respectively); it allows both qualitative and quantitative determinations. The particularly high advancement for detecting of influenza virus concerns impedimetric aptasensors.

The development of novel drugs with different mechanisms of action has dramatically changed the treatment landscape of AML patients in recent years. Considering a significant dysregulation of the immune system, inhibitors of immune checkpoint (ICI) proteins provide a substantial therapeutic option for those subjects. However, use of ICI in haematological malignancies remains very limited, in contrast to their wide use in solid tumours. Here, we analysed expression patterns of the most promising selected checkpoint-based therapeutic targets in AML patients. Peripheral blood of 72 untreated AML patients was used for flow cytometric analysis. Expression of PD-1, PD-L1, CTLA-4, and B7-H3 was assessed within CD4+ (Th) lymphocytes and CD33+ blast cells. Patients were stratified based on therapy outcome and cytogenetic molecular risk. AML non-responders (NR) showed a higher frequency of PD-1 in Th cells compared to those with complete remission (CR). Reduced blast cell level of CTLA-4 was another factor differentiating CR from NR subjects. Elevated levels of PD-1 were associated with a trend for poorer patients’ survival. Additionally, prognosis for AML patients was worse in case of a higher frequency of B7-H3 in Th lymphocytes. In summary, we showed the significance of selected ICI as outcome predictors in AML management. Further, multicentre studies are required for validation of those data.

Background: Chronic lymphocytic leukemia (CLL) is characterized by malignant B lymphocyte accumulation and progressive immune dysfunction. The immune checkpoint molecule TIM-3 and its ligand galectin-9 (Gal-9) contribute to T cell exhaustion, impairing anti-tumour immunity. Interleukin-27 (IL-27) has pleiotropic immunomodulatory properties, but its impact on TIM-3 and Gal-9 expression in CLL remains unclear. Methods: Peripheral blood mononuclear cells (PBMCs) from 20 treatment-naive CLL patients were cultured with or without IL-27 (100 ng/mL) for 72 h. Flow cytometry assessed TIM-3 and Gal-9 expression on CD4⁺, CD8⁺, and CD19⁺ cells. Results: IL-27 stimulation significantly increased TIM-3 expression on CD8⁺ T cells (2.18 ± 0.32% vs. 3.09 ± 0.49%, p = 0.009), a hallmark of T cell exhaustion. IL-27 also modestly increased intracellular Gal-9 levels in total lymphocytes (93.91 ± 1.17% vs. 96.55 ± 0.67%, p = 0.005). Additionally, IL-27 reduced CD4⁺ T cell proportions (26.71 ± 4.19% vs. 22.01 ± 3.23%, p = 0.010). Although numerically modest, these changes may be biologically pertinent in the context of checkpoint-mediated CD8⁺ T-cell exhaustion. Conclusions: IL-27 may enhance immunosuppressive mechanisms in CLL by modulating immune checkpoint expression, potentially contributing to disease progression. These ex vivo findings in PBMCs from CLL patients indicate the IL-27-associated modulation of checkpoint expression under the conditions tested. In the absence of parallel healthy-donor controls, CLL specificity cannot be established in this study.