Biomedical Chemistry: Research and Methods

The Downstream Extension of the Core Sequence of T7 Promoter in NASBA Primer Design: the Impact on Efficacy of Amplification

Fri, 13 Mar 2026 00:00:00 +0000

NASBA (Nucleic Acid Sequence Based Amplification) is a method of isothermal RNA amplification with a potential for laboratory and on-site detection of infectious agents. The method relies on the presence of the T7 RNA promoter in one of NASBA primers and NASBA efficacy depends to a large extent on the promoter strength. In in vitro transcription, the promoter strength is known to markedly depend on a sequence located right downstream of the T7 promoter core sequence. Here the efficacy of NASBA was experimentally evaluated for different sequence variants of the 8-nucleotide downstream extension of the T7 promoter core sequence. The variants were ranked based on the known levels of RNA yields in in vitro transcription. It has been found that the rank of the 8-nucleotide extension of the T7 promoter core sequence can provide a rational for designing efficient NASBA primers. However, not all of 8-nucleotide downstream extensions characterized by the highest RNA yields in in vitro transcription were found to provide the most efficient production of target RNA amplicons in NASBA. It was shown that a careful evaluation of primer’s ability to form secondary structures by using DNA folding algorithms was still required to select the best candidate NASBA primers.

Modern Materials for Non-Viral Delivery Systems in Gene Therapy

A.V. Radnaeva, E.A. Slobodkina, V.A. Tkachuk, P.I. Makarevich — Mon, 23 Mar 2026 00:00:00 +0000

Modern gene delivery systems are classified into viral and non-viral vectors. Despite the predominance of viral vectors in gene therapy drug development due to their high transduction efficiency, their application is limited by immunogenicity, the risk of insertional mutagenesis, and inflammatory responses. Non-viral systems offer a superior safety profile, scalable manufacturing potential, and flexibility in genetic cargo loading but are less effective in transfection efficiency. The main challenges affecting non-viral vector transfection include the low stability of nucleic acids in vivo, problems in delivering the genetic material into the cell nucleus, and the toxicity of chemical components within the vector design. To overcome the low delivery efficiency of genetic material by non-viral vector systems, further research should focus on optimizing the chemical structure of carrier molecules, their modification to enhance targeting, and detailed investigation of intracellular vector transport pathways. Currently, the most promising application areas for non-viral delivery systems are oncology, vaccine development, and pulmonary diseases.

New Generations of Antibodies and Scaffold Proteins as a Way to Create Highly Selective Conjugates for Oncology

I.V. Shulcheva, A.B. Ulitin — Tue, 24 Mar 2026 00:00:00 +0000

This review provides a systematic analysis of modern strategies for developing highly selective therapeutic conjugates for oncology. It examines the evolution from first-generation antibody-drug conjugates (ADCs) to advanced next-generation platforms. The focus is on key conjugate components: targeting modules (bispecific antibodies, small scaffold proteins — affibodies, DARPins, adnectins), linker systems with controlled release, and an expanding arsenal of cytotoxic and cytomodulatory payloads. Special attention is given to innovative technologies, such as PROTAC-ADCs, oligonucleotide conjugates, and photoimmunoconjugates, which enable targeting of "undruggable" molecules and manipulation of intracellular processes. Strategies for site-specific conjugation to obtain homogeneous preparations are analyzed. The conclusion is drawn that the convergence of refined components and novel platforms shapes the future of targeted therapy, aimed significantly at enhancing the therapeutic index and overcoming drug resistance.

Bacteriobots: Bacterial Microrobots and Their Potential in Cancer Diagnosis and Therapy

L.N. Ikryannikova — Fri, 13 Mar 2026 00:00:00 +0000

Oncological diseases represents one of the most serious public health problem, claiming millions of lives each year. Routine cancer treatment still has significant limitations, due to side effects, unsufficient effectiveness in metastasis and recurrence, and high cost. Therefore, the development of new approaches for antitumor therapy is an important and priority task. Bacteria can be considered as a versatile and flexible natural biomaterial that has the property of moving independently and penetrating into hard-to-reach areas of the human body, delivering therapeutic agents directly to cancer cells. Also, bacteria demonstrate the natural immunogenicity, which allows them to attract immune cells into the tumor microenvironment (TME) and promote the effectiveness of the immune response. This is a reason why the seemingly fantastic idea of creating a bacteriobot, an autonomous microrobot based on a living bacterium for delivering therapeutic cargo, is becoming more and more popular. This review highlights the basic principles of designing bacterial microrobots, ways to their targeting to cancer cells and supplying with therapeutic agents, as well as the safety of bacteriobots for humans and the prospects for their use in the treatment of malignant neoplasms.

Blood-Saliva Barrier: Models of its Reproduction

E.I. Dyachenko, L.V. Bel’skaya — Mon, 23 Mar 2026 00:00:00 +0000

In this review we have summarized existing approaches used to study the blood-saliva barrier in vitro. Investigating the structural and functional characteristics of the blood-saliva barrier in both health and disease requires models that adequately reflect real human physiology. Accordingly, we evaluated currently available research models, such as ex vivo, in vitro (including TR 146, HSY, TEER), oral mucosal equivalents (OME), and in silico systems. To build more accurate in vitro models of the blood-saliva barrier, it is necessary to consider additional parameters. These parameters include the rheological properties of saliva, changes in blood flow and innervation, the state of the immune system, and the oral microbiome. A comprehensive understanding of these components and the characteristics of the blood-saliva barrier is necessary for the development of complex in vitro models.