Functional Xeno Nucleic Acids for Biomedical Application

The clinical potential of l-oligonucleotides: challenges and opportunities

Chemically modified nucleotides are central to the development of biostable research tools and oligonucleotide therapeutics. In this context, l-oligonucleotides, the synthetic enantiomer of native d-nucleic acids, hold great promise. As enantiomers, l-oligonucleotides share the same physical and chemical properties as their native counterparts, yet their inverted l-(deoxy)ribose sugars afford them orthogonality towards the stereospecific environment of biology. Notably, l-oligonucleotides are highly resistant to degradation by cellular nucleases, providing them with superior biostability. As a result, l-oligonucleotides are being increasingly utilized for the development of diverse biomedical technologies, including molecular imaging tools, diagnostic biosensors, and aptamer-based therapeutics. Herein, we present recent such examples that highlight the clinical potential of l-oligonucleotides. Additionally, we provide our perspective on the remaining challenges and practical considerations currently associated with the use of l-oligonucleotides and explore potential solutions that will lead to the broader adoption of l-oligonucleotides in clinical applications.

Expanding the Horizon of the Xeno Nucleic Acid Space: Threose Nucleic Acids with Increased Information Storage

Xeno nucleic acids (XNAs) constitute a class of synthetic nucleic acid analogues characterized by distinct, non-natural modifications within the tripartite structure of the nucleic acid polymers. While most of the described XNAs contain a modification in only one structural element of the nucleic acid scaffold, this work explores the XNA chemical space to create more divergent variants with modifications in multiple parts of the nucleosidic scaffold. Combining the enhanced nuclease resistance of α-l-threofuranosyl nucleic acid (TNA) and the almost natural-like replication efficiency and fidelity of the unnatural hydrophobic base pair (UBP) TPT3:NaM, novel modified nucleoside triphosphates with a dual modification pattern were synthesized. We investigated the enzymatic incorporation of these nucleotide building blocks by XNA-compatible polymerases and confirmed the successful enzymatic synthesis of TPT3-modified TNA, while the preparation of NaM-modified TNA presented greater challenges. This study marks the first enzymatic synthesis of TNA with an expanded genetic alphabet (exTNA), opening promising opportunities in nucleic acid therapeutics, particularly for the selection and evolution of nuclease-resistant, high-affinity aptamers with increased chemical diversity.

A comprehensive review of the current progresses and material advances in perovskite solar cells

Recently, perovskite solar cells (PSCs) have attracted ample consideration from the photovoltaic community owing to their continually-increasing power conversion efficiency (PCE), viable solution-processed methods, and inexpensive materials ingredients. Over the past few years, the performance of perovskite-based devices has exceeded 25% due to superior perovskite films achieved using low-temperature synthesis procedures along with evolving appropriate interface and electrode-materials. The current review provides comprehensive knowledge to enhance the performance and materials advances for perovskite solar cells. The latest progress in terms of perovskite crystal structure, device construction, fabrication procedures, and challenges are thoroughly discussed. Also discussed are the different layers such as ETLs and buffer-layers employed in perovskite solar-cells, seeing their transmittance, carrier mobility, and band gap potentials in commercialization. Generally, this review delivers a critical assessment of the improvements, prospects, and trials of PSCs.

Artificial genetic polymers against human pathologies

Originally discovered by Nielsen in 1991, peptide nucleic acids and other artificial genetic polymers have gained a lot of interest from the scientific community. Due to their unique biophysical features these artificial hybrid polymers are now being employed in various areas of theranostics (therapy and diagnostics). The current review provides an overview of their structure, principles of rational design, and biophysical features as well as highlights the areas of their successful implementation in biology and biomedicine. Finally, the review discusses the areas of improvement that would allow their use as a new class of therapeutics in the future.