RNA-based therapeutics: current progress and future prospects

Exploring aptamers for targeted enrichment of X sperm in bovine: unraveling selective potential

Nucleic acid aptamers have been used in the past for the development of diagnostic methods against a number of targets such as bacteria, pesticides, cancer cells etc. In the present study, six rounds of Cell-SELEX were performed on a ssDNA aptamer library against X-enriched sperm cells from Sahiwal breed cattle. Sequencing was used to examine the aptamer sequences that shown affinity for sperm carrying the X chromosome in order to find any possible X-sperm-specific sequences. Out of 35 identified sequences, 14 were selected based on bioinformatics analysis like G-Score and Mfold structures. Further validation of their specificity was done via fluorescence microscopy. The interaction of biotinylated-aptamer with sperm was also determined by visualizing the binding of streptavidin coated magnetic beads on the head region of the sperm under bright field microscopy. Finally, a real-time experiment was designed for the validation of X-sperm enrichment by synthesized aptamer sequences. Among the studied sequences, aptamer 29a exhibited a higher affinity for X sperm compared to Y sperm in a mixed population of sperm cells. By using aptamer sequence 29a, we obtained an enrichment of 70% for X chromosome bearing sperm cells.

Illuminating the pathogenic role of SARS-CoV-2: Insights into competing endogenous RNAs (ceRNAs) regulatory networks

The appearance of SARS-CoV-2 in 2019 triggered a significant economic and health crisis worldwide, with heterogeneous molecular mechanisms that contribute to its development are not yet fully understood. Although substantial progress has been made in elucidating the mechanisms behind SARS-CoV-2 infection and therapy, it continues to rank among the top three global causes of mortality due to infectious illnesses. Non-coding RNAs (ncRNAs), being integral components across nearly all biological processes, demonstrate effective importance in viral pathogenesis. Regarding viral infections, ncRNAs have demonstrated their ability to modulate host reactions, viral replication, and host-pathogen interactions. However, the complex interactions of different types of ncRNAs in the progression of COVID-19 remains understudied. In recent years, a novel mechanism of post-transcriptional gene regulation known as "competing endogenous RNA (ceRNA)" has been proposed. Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and viral ncRNAs function as ceRNAs, influencing the expression of associated genes by sequestering shared microRNAs. Recent research on SARS-CoV-2 has revealed that disruptions in specific ceRNA regulatory networks (ceRNETs) contribute to the abnormal expression of key infection-related genes and the establishment of distinctive infection characteristics. These findings present new opportunities to delve deeper into the underlying mechanisms of SARS-CoV-2 pathogenesis, offering potential biomarkers and therapeutic targets. This progress paves the way for a more comprehensive understanding of ceRNETs, shedding light on the intricate mechanisms involved. Further exploration of these mechanisms holds promise for enhancing our ability to prevent viral infections and develop effective antiviral treatments.

RNA nanotechnology on the horizon: Self-assembly, chemical modifications, and functional applications

RNA nanotechnology harnesses the unique chemical and structural properties of RNA to build nanoassemblies and supramolecular structures with dynamic and functional capabilities. This review focuses on design and assembly approaches to building RNA structures, the RNA chemical modifications used to enhance stability and functionality, and modern-day applications in therapeutics, biosensing, and bioimaging.

Analysis of the pharmacokinetics and efficacy of RBD1016 - A GalNAc-siRNA targeting Hepatitis B Virus X gene using semi-mechanistic PK/PD model

Small interference RNA (siRNA) is a class of short double-stranded RNA molecules that cause mRNA degradation through an RNA interference mechanism and is a promising therapeutic modality. RBD1016 is a siRNA drug in clinical development for the treatment of chronic Hepatitis B Virus (HBV) infection, which contains a conjugated with N-acetylglucosamine moiety that can facilitate its hepatic delivery. We aimed to construct a semi-mechanistic model of RBD1016 in pre-clinical animals, to elucidate the pharmacokinetic/pharmacodynamic (PK/PD) profiles in mice and PK profiles in monkeys, which can lay the foundation for potential future translation of RBD1016 PK and PD from the pre-clinical stage to the clinic stage. The proposed semi-mechanistic PK/PD model fitted PK and PD data in HBV transgenic mice well and described plasma and liver concentrations in the monkeys well. The simulation results showed that our model has a reasonable predictive ability for Hepatitis B surface antigen (HBsAg) levels after multiple dosing in mice. Further PK and PD data for RBD1016, including clinical data, will assist in refining the model presented here. Our current effort focused on model building for RBD1016, we anticipate that the model could apply to other GalNAc-siRNA drugs.

A polyamino acid-based phosphatidyl polymer library for in vivo mRNA delivery with spleen targeting ability

A qualified delivery system is crucial for the successful application of messenger RNA (mRNA) technology. While lipid nanoparticles (LNPs) are currently the predominant platform for mRNA delivery, they encounter challenges such as high inflammation and difficulties in targeting non-liver tissues. Polymers offer a promising delivery solution, albeit with limitations including low transfection efficiency and potential high toxicity. Herein, we present a poly(L-glutamic acid)-based phosphatidyl polymeric carrier (PLG-PPs) for mRNA delivery that combines the dual advantages of phospholipids and polymers. The PLGs grafted with epoxy groups were firstly modified with different amines and then with alkylated dioxaphospholane oxides, which provided a library of PLG polymers grafted with various phosphatidyl groups. In vitro studies proved that PLG-PPs/mRNA polyplexes exhibited a significant increase in mRNA expression, peaking 14 716 times compared to their non-phosphatidyl parent polymer. Impressively, the subset PA8-PL3 not only facilitated efficient mRNA transfection but also selectively delivered mRNA to the spleen instead of the liver (resulting in 69.73% protein expression in the spleen) once intravenously administered. This type of phosphatidyl PLG polymer library provides a novel approach to the construction of mRNA delivery systems especially for spleen-targeted mRNA therapeutic delivery.

Posterior eye delivery of angiogenesis-inhibiting RNA nanoparticles via subconjunctival injection

Neovascularization contributes to various posterior eye segment diseases such as age-related macular degeneration and diabetic retinopathy. RNA nanoparticles were demonstrated previously to enter the corneal and retinal cells after subconjunctival injection for ocular delivery. In the present study, antiangiogenic aptamers (anti-vascular endothelial growth factor (VEGF) and anti-angiopoietin-2 (Ang2) aptamers) were conjugated to RNA nanoparticles. The objectives were to investigate the clearance and distribution of these angiogenesis-inhibiting RNA nanoparticles after subconjunctival injection in vivo and their antiangiogenic effects for inhibiting ocular neovascularization in vitro. The results in the whole-body fluorescence imaging study showed that the clearance of RNA nanoparticles was size-dependent with no significant differences between RNA nanoparticles with and without the aptamers except for pRNA-3WJ. The distribution study of RNA nanoparticles by confocal microscopy of the dissected eye tissues in vivo indicated cell internalization of the larger RNA nanoparticles in the retina and retinal pigment epithelium after subconjunctival injection, and the larger nanoparticles with aptamers showed higher levels of cell internalization than those without. In the cell proliferation assay in vitro, RNA nanoparticles with multiple aptamers had higher antiangiogenic effects. With both longer retention time and high antiangiogenic effect, SQR-VEGF-Ang2 could be a promising RNA nanoparticle for posterior eye delivery.

Effective delivery of anti-PD-L1 siRNA with human heavy chain ferritin (HFn) in acute myeloid leukemia cell lines

Because of the high biocompatibility, self-assembly capability, and CD71-mediated endocytosis, using human heavy chain ferritin (HFn) as a nanocarrier would greatly increase therapeutic effectiveness and reduce possible adverse events. Anti-PD-L1 siRNA can downregulate the level of PD-L1 on tumor cells, resulting in the activation of effector T cells against leukemia. Therefore, this study aimed to produce the tumor-targeting siPD-L1/HFn nanocarrier. Briefly, the HFn coding sequence was cloned into a pET-28a, and the constructed expression plasmid was subsequently transformed into E. coli BL21. After induction of Isopropyl β-D-1-thiogalactopyranoside (IPTG), HFn was purified with Ni-affinity chromatography and dialyzed against PBS. The protein characteristics were analyzed using SDS-PAGE, Western Blot, and Dynamic light scattering (DLS). The final concentration was assessed using the Bicinchoninic acid (BCA) assay. The encapsulation was performed using the standard pH system. The treatment effects of siPD-L1/HFn were carried out on HL-60 and K-562 cancer cell lines. The RT-PCR was used to determine the mRNA expression of PD-L1. The biocompatibility and excretion of siPD-L1/HFn have also been evaluated. The expression and purity of HFn were well verified through SDS-PAGE, WB, and DLS. RT-PCR analyses also showed significant siRNA-mediated PD-L1 silencing in both HL-60 and K-562 cells. Our study suggested a promising approach for siRNA delivery. This efficient delivery system can pave the way for the co-delivery of siRNAs and multiple chemotherapies to address the emerging needs of cancer combination therapy.

Thermally Robust Solvent-Free Liquid Polyplexes for Heat-Shock Protection and Long-Term Room Temperature Storage of Therapeutic Nucleic Acids

Nucleic acid therapeutics have attracted recent attention as promising preventative solutions for a broad range of diseases. Nonviral delivery vectors, such as cationic polymers, improve the cellular uptake of nucleic acids without suffering the drawbacks of viral delivery vectors. However, these delivery systems are faced with a major challenge for worldwide deployment, as their poor thermal stability elicits the need for cold chain transportation. Here, we demonstrate a biomaterial strategy to drastically improve the thermal stability of DNA polyplexes. Importantly, we demonstrate long-term room temperature storage with a transfection efficiency maintained for at least 9 months. Additionally, extreme heat shock studies show retained luciferase expression after heat treatment at 70 °C. We therefore provide a proof of concept for a platform biotechnology that could provide long-term room temperature storage for temperature-sensitive nucleic acid therapeutics, eliminating the need for the cold chain, which in turn would reduce the cost of distributing life-saving therapeutics worldwide.

Autophagy-associated non-coding RNAs: Unraveling their impact on Parkinson's disease pathogenesis

BACKGROUND

Parkinson's disease (PD) is a degenerative neurological condition marked by the gradual loss of dopaminergic neurons in the substantia nigra pars compacta. The precise etiology of PD remains unclear, but emerging evidence suggests a significant role for disrupted autophagy-a crucial cellular process for maintaining protein and organelle integrity.

METHODS

This review focuses on the role of non-coding RNAs (ncRNAs) in modulating autophagy in PD. We conducted a comprehensive review of recent studies to explore how ncRNAs influence autophagy and contribute to PD pathophysiology. Special attention was given to the examination of ncRNAs' regulatory impacts in various PD models and patient samples.

RESULTS

Findings reveal that ncRNAs are pivotal in regulating key processes associated with PD progression, including autophagy, α-synuclein aggregation, mitochondrial dysfunction, and neuroinflammation. Dysregulation of specific ncRNAs appears to be closely linked to these pathogenic processes.

CONCLUSION

ncRNAs hold significant therapeutic potential for addressing autophagy-related mechanisms in PD. The review highlights innovative therapeutic strategies targeting autophagy-related ncRNAs and discusses the challenges and prospective directions for developing ncRNA-based therapies in clinical practice. The insights from this study underline the importance of ncRNAs in the molecular landscape of PD and their potential in novel treatment approaches.

External Guide Sequence Effectively Suppresses the Gene Expression and Replication of Herpes Simplex Virus 2

Ribonuclease P (RNase P) complexed with an external guide sequence (EGS) represents a promising nucleic acid-based gene targeting approach for gene expression knock-down and modulation. The RNase P-EGS strategy is unique as an EGS can be designed to basepair any mRNA sequence and recruit intracellular RNase P for hydrolysis of the target mRNA. In this study, we provide the first direct evidence that the RNase P-based approach effectively blocks the gene expression and replication of herpes simplex virus 2 (HSV-2), the causative agent of genital herpes. We constructed EGSs to target the mRNA encoding HSV-2 single-stranded DNA binding protein ICP8, which is essential for viral DNA genome replication and growth. In HSV-2 infected cells expressing a functional EGS, ICP8 levels were reduced by 85%, and viral growth decreased by 3000 folds. On the contrary, ICP8 expression and viral growth exhibited no substantial differences between cells expressing no EGS and those expressing a disabled EGS with mutations precluding RNase P recognition. The anti-ICP8 EGS is specific in targeting ICP8 because it only affects ICP8 expression but does not affect the expression of the other viral immediate-early and early genes examined. This study shows the effective and specific anti-HSV-2 activity of the RNase P-EGS approach and demonstrates the potential of EGS RNAs for anti-HSV-2 applications.

Emerging Futuristic Targeted Therapeutics: A Comprising Study Towards a New Era for the Management of TNBC

Triple-negative breast cancer is characterized by high lethality attributed to factors such as chemoresistance, transcriptomic, and genomic heterogeneity, leading to a poor prognosis and limiting available targeted treatment options. While the identification of molecular targets remains pivotal for therapy involving chemo drugs, the current challenge lies in the poor response rates, low survival rates, and frequent relapses. Despite various clinical investigations exploring molecular targeted therapies in conjunction with conventional chemo treatment, the outcomes have been less than optimal. The critical need for more effective therapies underscores the urgency to discover potent novel treatments, including molecular and immune targets, as well as emerging strategies. This review provides a comprehensive analysis of conventional treatment approaches and explores emerging molecular and immune-targeted therapeutics, elucidating their mechanisms to address the existing obstacles for a more effective management of triple-negative breast cancer.

The landscape of nanoparticle-based siRNA delivery and therapeutic development

Five small interfering RNA (siRNA)-based therapeutics have been approved by the Food and Drug Administration (FDA), namely patisiran, givosiran, lumasiran, inclisiran, and vutrisiran. Besides, siRNA delivery to the target site without toxicity is a big challenge for researchers, and naked-siRNA delivery possesses several challenges, including membrane impermeability, enzymatic degradation, mononuclear phagocyte system (MPS) entrapment, fast renal excretion, endosomal escape, and off-target effects. The siRNA therapeutics can silence any disease-specific gene, but their intracellular and extracellular barriers limit their clinical applications. For this purpose, several modifications have been employed to siRNA for better transfection efficiency. Still, there is a quest for better delivery systems for siRNA delivery to the target site. In recent years, nanoparticles have shown promising results in siRNA delivery with minimum toxicity and off-target effects. Patisiran is a lipid nanoparticle (LNP)-based siRNA formulation for treating hereditary transthyretin-mediated amyloidosis that ultimately warrants the use of nanoparticles from different classes, especially lipid-based nanoparticles. These nanoparticles may belong to different categories, including lipid-based, polymer-based, and inorganic nanoparticles. This review briefly discusses the lipid, polymer, and inorganic nanoparticles and their sub-types for siRNA delivery. Finally, several clinical trials related to siRNA therapeutics are addressed, followed by the future prospects and conclusions.

Non-covalent binding interaction of bioactive coumarin esculetin with calf thymus DNA and yeast transfer RNA: A detailed investigation to decipher the binding affinities, binding location, interacting forces and structural alterations at a molecular level

Esculetin is a well-known coumarin derivative found abundantly in nature possessing an extensive array of pharmacological and therapeutic properties. Consequently, to comprehend its molecular recognition mechanism, our objective is to conduct a complete investigation of its interactions with the nucleic acid, specifically ct-DNA, and t-RNA, using spectroscopic and computational techniques. The intrinsic fluorescence of esculetin is quenched when it interacts with ct-DNA and t-RNA, and this occurs through a static quenching mechanism. The thermodynamic parameters demonstrated that the interaction is influenced by hydrogen bonding and weak van der Waals forces. CD and FT-IR results revealed no conformational changes in ct-DNA and t-RNA structure on binding with esculetin. Furthermore, competitive displacement assay with ethidium bromide, melting temperature, viscosity measurement, and potassium iodide quenching experiments, reflected that esculetin probably binds to the minor groove of ct-DNA. The molecular docking results provided further confirmation for the spectroscopic findings, including the binding location of esculetin and binding energies of esculetin complexes with ct-DNA and t-RNA. Molecular dynamics simulation studies demonstrated the conformational stability and flexibility of nucleic acids.

Aptamer-Based Targeting of Cancer: A Powerful Tool for Diagnostic and Therapeutic Aims

Cancer is known as one of the most significant causes of death worldwide, and, in spite of novel therapeutic methods, continues to cause a considerable number of deaths. Targeted molecular diagnosis and therapy using aptamers with high affinity have become popular techniques for pathological angiogenesis and cancer therapy scientists. In this paper, several aptamer-based diagnostic and therapeutic techniques such as aptamer-nanomaterial conjugation, aptamer-drug conjugation (physically or covalently), and biosensors, which have been successfully designed for biomarkers, were critically reviewed. The results demonstrated that aptamers can potentially be incorporated with targeted delivery systems and biosensors for the detection of biomarkers expressed by cancer cells. Aptamer-based therapeutic and diagnostic methods, representing the main field of medical sciences, possess high potential for use in cancer therapy, pathological angiogenesis, and improvement of community health. The clinical use of aptamers is limited due to target impurities, inaccuracy in the systematic evolution of ligands via exponential enrichment (SELEX)stage process, and in vitro synthesis, making them unreliable and leading to lower selectivity for in vivo targets. Moreover, size, behavior, probable toxicity, low distribution, and the unpredictable behavior of nanomaterials in in vivo media make their usage in clinical assays critical. This review is helpful for the implementation of aptamer-based therapies which are effective and applicable for clinical use and the design of future studies.

Types of RNA therapeutics

RNA therapy is one of the new treatments using small RNA molecules to target and regulate gene expression. It involves the application of synthetic or modified RNA molecules to inhibit the expression of disease-causing genes specifically. In other words, it silences genes and suppresses the transcription process. The main theory behind RNA therapy is that RNA molecules can prevent the translation into proteins by binding to specific messenger RNA (mRNA) molecules. By targeting disease-related mRNA molecules, RNA therapy can effectively silence or reduce the development of harmful proteins. There are different types of RNA molecules used in therapy, including small interfering RNAs (siRNAs), microRNAs (miRNAs), aptamer, ribozyme, and antisense oligonucleotides (ASOs). These molecules are designed to complement specific mRNA sequences, allowing them to bind and degrade the targeted mRNA or prevent its translation into protein. Nanotechnology is also highlighted to increase the efficacy of RNA-based drugs. In this chapter, while examining various methods of RNA therapy, we discuss the advantages and challenges of each.

Apoptosis Inhibitor 5: A Multifaceted Regulator of Cell Fate

Apoptosis, or programmed cell death, is a fundamental process that maintains tissue homeostasis, eliminates damaged or infected cells, and plays a crucial role in various biological phenomena. The deregulation of apoptosis is involved in many human diseases, including cancer. One of the emerging players in the intricate regulatory network of apoptosis is apoptosis inhibitor 5 (API5), also called AAC-11 (anti-apoptosis clone 11) or FIF (fibroblast growth factor-2 interacting factor). While it may not have yet the same level of notoriety as some other cancer-associated proteins, API5 has garnered increasing attention in the cancer field in recent years, as elevated API5 levels are often associated with aggressive tumor behavior, resistance to therapy, and poor patient prognosis. This review aims to shed light on the multifaceted functions and regulatory mechanisms of API5 in cell fate decisions as well as its interest as therapeutic target in cancer.

The development and technologies of RNA therapeutics

Since it was discovered for over 20 years ago, the potentiality of siRNAs in gene silencing in vitro and in vivo models has been recognized. Several studies in the new generation, molecular mechanisms, target attachment, and purification of RNA have supported the development of RNA therapeutics for a variety of applications. RNA therapeutics are growing rapidly with various platforms contributing to the standard of personalized medicine and rare disease treatment. Therefore, understanding the development and technologies of RNA therapeutics becomes a crucial point for new drug generation. Here, the primary purpose of this review is to provide a general view of six therapeutic categories that make up RNA-based therapeutic approaches, including RNA-target therapeutics, protein-targeted therapeutics, cellular reprogramming and tissues engineering, RNA-based protein replacement therapeutics, RNA-based genome editing, and RNA-based immunotherapies based on non-coding RNAs and coding RNA. Furthermore, we present an overview of the RNA strategies regarding viral approaches and nonviral approaches in designing a new generation of RNA technologies. The advantages and challenges of using RNA therapeutics are also discussed along with various approaches for RNA delivery. Therefore, this review is designed to provide updated reference evidence of RNA therapeutics in the battle against rare or difficult-to-treat diseases for researchers in this field.

Ultrasound-Induced Microbubble Cavitation for Targeted Delivery of MiR-29b Mimic to Treat Cardiac Fibrosis

OBJECTIVE

Cardiac fibrosis contributes to adverse ventricular remodeling and is associated with loss of miR-29b. Overexpression of miR-29b via plasmid or intravenous injection of microRNA mimic has blunted fibrosis, but these are inefficient and non-targeted delivery strategies. In this study, we tested the hypothesis that delivery of microRNA-29b (miR-29b) using ultrasound-targeted microbubble cavitation (UTMC) of miR-29b-loaded microbubbles would attenuate cardiac fibrosis and preserve left ventricular (LV) function.

METHODS

Lipid microbubbles were loaded with miR-29b mimic (miR-29b-MB) or negative control (NC) mimic (NC-MB), placed with cardiac fibroblasts (CFs) and treated with pulsed ultrasound. Cells were harvested to measure downstream fibrotic mediators. Mice received angiotensin II (ANG II) infusion causing afterload increase and direct ANG II-induced cardiac fibrosis. UTMC of miRNA-loaded microbubbles was administered to the heart at days 0, 3 and 7. Serial echocardiography was performed, and hearts were harvested on day 10.

RESULTS

UTMC treatment of CFs with miR-29b-MB increased miR-29b and decreased fibrotic transcripts compared with NC-MB treatment. In vivo UTMC + NC-MB led to increased LV mass, reduction in cardiac function and increase in fibrotic markers, demonstrating ANGI II-induced adverse cardiac remodeling. Mice treated with UTMC + miR-29b-MB had preservation of cardiac function, downregulation of cardiac fibrillin and trends of lower COL1A1, COL1A2 and COL3 mRNA and decreased cardiac α-smooth muscle protein.

CONCLUSION

UTMC-mediated delivery of miR-29b mimic blunts expression of fibrosis markers and preserves LV function in ANG II-induced cardiac fibrosis.

Stability and mechanism of threose nucleic acid toward acid-mediated degradation

Xeno-nucleic acids (XNAs) have gained significant interest as synthetic genetic polymers for practical applications in biomedicine, but very little is known about their biophysical properties. Here, we compare the stability and mechanism of acid-mediated degradation of α-l-threose nucleic acid (TNA) to that of natural DNA and RNA. Under acidic conditions and elevated temperature (pH 3.3 at 90°C), TNA was found to be significantly more resistant to acid-mediated degradation than DNA and RNA. Mechanistic insights gained by reverse-phase HPLC and mass spectrometry indicate that the resilience of TNA toward low pH environments is due to a slower rate of depurination caused by induction of the 2'-phosphodiester linkage. Similar results observed for 2',5'-linked DNA and 2'-O-methoxy-RNA implicate the position of the phosphodiester group as a key factor in destabilizing the formation of the oxocarbenium intermediate responsible for depurination and strand cleavage of TNA. Biochemical analysis indicates that strand cleavage occurs by β-elimination of the 2'-phosphodiester linkage to produce an upstream cleavage product with a 2'-threose sugar and a downstream cleavage product with a 3' terminal phosphate. This work highlights the unique physicochemical properties available to evolvable non-natural genetic polymers currently in development for biomedical applications.

Liver factor B silencing to cure C3 glomerulopathy: Evidence from a mouse model of complement dysregulation

Uncontrolled activation of the alternative pathway (AP) of complement, due to genetic and/or acquired defects, plays a primary pathogenetic role in C3 glomerulopathy (C3G), a rare and heterogeneous disease characterised by predominant C3 fragment deposition within the glomerulus, as well as glomerular damage. There are currently no approved disease-specific treatments for C3G, but new drugs that directly counteract AP dysregulation, targeting components of the pathway, have opened promising new perspectives for managing the disease. Complement factor B (FB), which is primarily synthesised by hepatocytes, is a key component of the AP, as it drives the central amplification loop of the complement system. In this study we used a GalNAc (N-Acetylgalactosamine)-conjugated siRNA to selectively target and suppress liver FB expression in two mouse models characterised by the complete (Cfh-/- mice) or partial (Cfh+/-) loss of function of complement factor H (FH). Homozygous deletion of FH induced a severe C3G phenotype, with strong dysregulation of the AP of complement, glomerular C3 deposition and almost complete C3 consumption. Mice with a heterozygous deletion of FH had intermediate C3 levels and exhibited slower disease progression, resembling human C3G more closely. Here we showed that FB siRNA treatment did not improve serum C3 levels, nor limit glomerular C3 deposition in Cfh-/- mice, while it did normalise circulating C3 levels, reduce glomerular C3 deposits, and limit mesangial electron-dense deposits in Cfh+/- mice. The present data provide important insights into the potential benefits and limitations of FB-targeted inhibition strategies and suggest RNA interference-mediated FB silencing in the liver as a possible therapeutic approach for treating C3G patients with FH haploinsufficiency.

Eradication of CD48-positive tumors by selectively enhanced YTS cells harnessing the lncRNA NeST

Natural killer (NK) cells are currently used in clinical trials to treat tumors. However, such therapies still suffer from problems such as donor variability, reproducibility, and more, which prevent a wider use of NK cells therapeutics. Here we show a potential immunotherapy combining NK cell-mediated tumor eradiation and long non-coding (lnc) RNAs. We overexpressed the interferon (IFN) γ secretion-enhancing lncRNA nettoie Salmonella pas Theiler's (NeST) in the NK cell-like cell line YTS. YTS cells express the co-stimulatory receptor 2B4 whose main ligand is CD48. On YTS cells, 2B4 functions by direct activation. We showed that NeST overexpression in YTS cells resulted in increased IFNγ release upon interaction with CD48 (selectively enhanced (se)YTS cells). Following irradiation, the seYTS cells lost proliferation capacity but were still able to maintain their killing and IFNγ secretion capacities. Finally, we demonstrated that irradiated seYTS inhibit tumor growth in vivo. Thus, we propose seYTS cells as off-the-shelve therapy for CD48-expressing tumors.

pH-Responsive Dynaplexes as Potent Apoptosis Inductors by Intracellular Delivery of Survivin siRNA

Gene knockdown by siRNA offers an unrestricted choice of targets and specificity based on the principle of complementary Watson-Crick base pairing with mRNA. However, the negative charge, large molecular size, and susceptibility to enzymatic degradation of siRNA impede its successful transfection, hence limiting its potential for therapeutic use. The development of efficient and safe siRNA transfection agents is, therefore, critical for siRNA-based therapy. Herein, we developed a protein-based biodynamic polymer (biodynamer) that showed potential as a siRNA transfection vector, owing to its excellent biocompatibility, easy tunability, and dynamic polymerization under acidic environments. The positively charged biodynamers formed stable dynamic nanocomplexes (XL-DPs, hydrodynamic diameter of approximately 104 nm) with siRNA via electrostatic interactions and chemical cross-linking. As a proof of concept, the optimized XL-DPs were stable in physiological conditions with serum proteins and demonstrated significant pH-dependent size change and degradability, as well as siRNA release capability. The minimal cytotoxicity and excellent cellular uptake of XL-DPs effectively supported the intracellular delivery of siRNA. Our study demonstrated that the XL-DPs in survivin siRNA delivery enabled potent knockdown of survivin mRNA and induced notable apoptosis of carcinoma cells (2.2 times higher than a lipid-based transfection agent, Lipofectamine 2000). These findings suggested that our XL-DPs hold immense potential as a promising platform for siRNA delivery and can be considered strong candidates in the advancement of next-generation transfection agents.

Regenerative Potential of Injured Spinal Cord in the Light of Epigenetic Regulation and Modulation

A spinal cord injury is a form of physical harm imposed on the spinal cord that causes disability and, in many cases, leads to permanent mammalian paralysis, which causes a disastrous global issue. Because of its non-regenerative aspect, restoring the spinal cord's role remains one of the most daunting tasks. By comparison, the remarkable regenerative ability of some regeneration-competent species, such as some Urodeles (Axolotl), Xenopus, and some teleost fishes, enables maximum functional recovery, even after complete spinal cord transection. During the last two decades of intensive research, significant progress has been made in understanding both regenerative cells' origins and the molecular signaling mechanisms underlying the regeneration and reconstruction of damaged spinal cords in regenerating organisms and mammals, respectively. Epigenetic control has gradually moved into the center stage of this research field, which has been helped by comprehensive work demonstrating that DNA methylation, histone modifications, and microRNAs are important for the regeneration of the spinal cord. In this review, we concentrate primarily on providing a comparison of the epigenetic mechanisms in spinal cord injuries between non-regenerating and regenerating species. In addition, we further discuss the epigenetic mediators that underlie the development of a regeneration-permissive environment following injury in regeneration-competent animals and how such mediators may be implicated in optimizing treatment outcomes for spinal cord injurie in higher-order mammals. Finally, we briefly discuss the role of extracellular vesicles (EVs) in the context of spinal cord injury and their potential as targets for therapeutic intervention.

Enhanced anticancer activity of siRNA and drug codelivered by anionic biopolymer: overcoming electrostatic repulsion

Aim: To codeliver an anticancer drug (doxorubicin) and siRNA in the form of nanoparticles into CD44-overexpressing colon cancer cells (HT-29) using an anionic, amphiphilic biopolymer comprising modified hyaluronic acid (6-O-[3-hexadecyloxy-2-hydroxypropyl]-hyaluronic acid). Materials & methods: Characterization of nanoparticles was performed using dynamic light scattering, scanning electron microscopy, transmission electron microscopy, molecular docking, in vitro drug release and gel mobility assays. Detailed in vitro experiments, including a gene silencing study and western blot, were also performed. Results: A 69% knockdown of the target gene was observed, and western blot showed 5.7-fold downregulation of the target protein. The repulsive forces between siRNA and 6-O-(3-hexadecyloxy-2-hydroxypropyl)-hyaluronic acid were overcome by hydrogen bonding and hydrophobic interactions. Conclusion: The authors successfully codelivered a drug and siRNA by anionic vector.

The application of extracellular vesicles in colorectal cancer metastasis and drug resistance: recent advances and trends

Colorectal cancer (CRC) has high incidence and mortality rates and is one of the most common cancers of the digestive tract worldwide. Metastasis and drug resistance are the main causes of cancer treatment failure. Studies have recently suggested extracellular vesicles (EVs) as a novel mechanism for intercellular communication. They are vesicular particles, which are secreted and released into biological fluids, such as blood, urine, milk, etc., by a variety of cells and carry numerous biologically active molecules, including proteins, nucleic acids, lipids, metabolites, etc. EVs play a crucial part in the metastasis and drug resistance of CRC by delivering cargo to recipient cells and modulating their behavior. An in-depth exploration of EVs might facilitate a comprehensive understanding of the biological behavior of CRC metastasis and drug resistance, which might provide a basis for developing therapeutic strategies. Therefore, considering the specific biological properties of EVs, researchers have attempted to explore their potential as next-generation delivery systems. On the other hand, EVs have also been demonstrated as biomarkers for the prediction, diagnosis, and presumed prognosis of CRC. This review focuses on the role of EVs in regulating the metastasis and chemoresistance of CRC. Moreover, the clinical applications of EVs are also discussed.

Nanotechnology-enabled gene delivery for cancer and other genetic diseases

INTRODUCTION

Despite gene therapy is ideal for genetic abnormality-related diseases, the easy degradation, poor targeting, and inefficiency in entering targeted cells are plaguing the effective delivery of gene therapy. Viral and non-viral vectors have been used for delivering gene therapeutics in vivo by safeguarding nucleic acid agents to target cells and to reach the specific intracellular location. A variety of nanotechnology-enabled safe and efficient systems have been successfully developed to improve the targeting ability for effective therapeutic delivery of genetic drugs.

AREAS COVERED

In this review, we outline the multiple biological barriers associated with gene delivery process, and highlight recent advances to gene therapy strategy in vivo, including gene correction, gene silencing, gene activation and genome editing. We point out current developments and challenges exist of non-viral and viral vector systems in association with chemical and physical gene delivery technologies and their potential for the future.

EXPERT OPINION

This review focuses on the opportunities and challenges to various gene therapy strategy, with specific emphasis on overcoming the challenges through the development of biocompatibility and smart gene vectors for potential clinical application.

Development of Cationic Lipid LAH4-L1 siRNA Complexes for Focused Ultrasound Enhanced Tumor Uptake

RNAi has considerable potential as a cancer therapeutic approach, but effective and efficient delivery of short interfering RNA (siRNA) to tumors remains a major hurdle. It remains a challenge to prepare a functional siRNA complex, target enough dose to the tumor, and stimulate its internalization into tumor cells and its release to the cytoplasm. Here, we show how these key barriers to siRNA delivery can be overcome with a complex─comprising siRNA, cationic lipids, and pH-responsive peptides─that is suited to tumor uptake enhancement via focused ultrasound (FUS). The complex provides effective nucleic acid encapsulation, nuclease protection, and endosomal escape such that gene silencing in cells is substantially more effective than that obtained with either equivalent lipoplexes or commercial reagents. In mice bearing MDA-MB-231 breast cancer xenografts, both lipid and ternary, lipid:peptide:siRNA complexes, prepared with near-infrared fluorescently labeled siRNA, accumulate in tumors following FUS treatments. Therefore, combining a well-designed lipid:peptide:siRNA complex with FUS tumor treatments is a promising route to achieve robust in vivo gene delivery.

Lipid-based colloidal nanoparticles for applications in targeted vaccine delivery

Bioactive molecules and their effects have been influenced by their solubility and administration route. In many therapeutic reagents, the performance of therapeutics is dependent on physiological barriers in the human body and delivery efficacy. Therefore, an effective and stable therapeutic delivery promotes pharmaceutical advancement and suitable biological usage of drugs. In the biological and pharmacological industries, lipid nanoparticles (LNPs) have emerged as a potential carrier to deliver therapeutics. Since studies reported doxorubicin-loaded liposomes (Doxil®), LNPs have been applied to numerous clinical trials. Lipid-based nanoparticles, including liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid nanoparticles, have also been developed to deliver active ingredients in vaccines. In this review, we present the type of LNPs used to develop vaccines with attractive advantages. We then discuss messenger RNA (mRNA) delivery for the clinical application of mRNA therapeutic-loaded LNPs and recent research trend of LNP-based vaccine development.

Aid or Antagonize: Nuclear Long Noncoding RNAs Regulate Host Responses and Outcomes of Viral Infections

Long noncoding RNAs (lncRNAs) are transcripts measuring >200 bp in length and devoid of protein-coding potential. LncRNAs exceed the number of protein-coding mRNAs and regulate cellular, developmental, and immune pathways through diverse molecular mechanisms. In recent years, lncRNAs have emerged as epigenetic regulators with prominent roles in health and disease. Many lncRNAs, either host or virus-encoded, have been implicated in critical cellular defense processes, such as cytokine and antiviral gene expression, the regulation of cell signaling pathways, and the activation of transcription factors. In addition, cellular and viral lncRNAs regulate virus gene expression. Viral infections and associated immune responses alter the expression of host lncRNAs regulating immune responses, host metabolism, and viral replication. The influence of lncRNAs on the pathogenesis and outcomes of viral infections is being widely explored because virus-induced lncRNAs can serve as diagnostic and therapeutic targets. Future studies should focus on thoroughly characterizing lncRNA expressions in virus-infected primary cells, investigating their role in disease prognosis, and developing biologically relevant animal or organoid models to determine their suitability for specific therapeutic targeting. Many cellular and viral lncRNAs localize in the nucleus and epigenetically modulate viral transcription, latency, and host responses to infection. In this review, we provide an overview of the role of nuclear lncRNAs in the pathogenesis and outcomes of viral infections, such as the Influenza A virus, Sendai Virus, Respiratory Syncytial Virus, Hepatitis C virus, Human Immunodeficiency Virus, and Herpes Simplex Virus. We also address significant advances and barriers in characterizing lncRNA function and explore the potential of lncRNAs as therapeutic targets.

Streptavidin-Saporin: Converting Biotinylated Materials into Targeted Toxins

Streptavidin-Saporin can be considered a type of ‘secondary’ targeted toxin. The scientific community has taken advantage of this conjugate in clever and fruitful ways using many kinds of biotinylated targeting agents to send saporin into a cell selected for elimination. Saporin is a ribosome-inactivating protein that causes inhibition of protein synthesis and cell death when delivered inside a cell. Streptavidin-Saporin, mixed with biotinylated molecules to cell surface markers, results in powerful conjugates that are used both in vitro and in vivo for behavior and disease research. Streptavidin-Saporin harnesses the ‘Molecular Surgery’ capability of saporin, creating a modular arsenal of targeted toxins used in applications ranging from the screening of potential therapeutics to behavioral studies and animal models. The reagent has become a well-published and validated resource in academia and industry. The ease of use and diverse functionality of Streptavidin-Saporin continues to have a significant impact on the life science industry.

Biosensors based on functional nucleic acids and isothermal amplification techniques

In the past few years, with the in-depth research of functional nucleic acids and isothermal amplification techniques, their applications in the field of biosensing have attracted great interest. Since functional nucleic acids have excellent flexibility and convenience in their structural design, they have significant advantages as recognition elements in biosensing. At the same time, isothermal amplification techniques have higher amplification efficiency, so the combination of functional nucleic acids and isothermal amplification techniques can greatly promote the widespread application of biosensors. For the purpose of further improving the performance of biosensors, this review introduces several widely used functional nucleic acids and isothermal amplification techniques, as well as their classification, basic principles, application characteristics, and summarizes their important applications in the field of biosensing. We hope to provide some references for the design and construction of new tactics to enhance the detection sensitivity and detection range of biosensing.

Mapping of RNase P Ribozyme Regions in Proximity with a Human RNase P Subunit Protein Using Fe(II)-EDTA Cleavage and Nuclease Footprint Analyses

Ribonuclease P (RNase P), which may consist of both protein subunits and a catalytic RNA part, is responsible for 5' maturation of tRNA by cleaving the 5'-leader sequence. In Escherichia coli, RNase P contains a catalytic RNA subunit (M1 RNA) and a protein factor (C5 protein). In human cells, RNase P holoenzyme consists of an RNA subunit (H1 RNA) and multiple protein subunits that include human RPP29 protein. M1GS, a sequence specific targeting ribozyme derived from M1 RNA, can be constructed to target a specific mRNA to degrade it in vitro. Recent studies have shown that M1GS ribozymes are efficient in blocking the expression of viral mRNAs in cultured cells and in animals. These results suggest that RNase P ribozymes have the potential to be useful in basic research and in clinical applications. It has been shown that RNase P binding proteins, such as C5 protein and RPP29, can enhance the activities of M1GS RNA in processing a natural tRNA substrate and a target mRNA. Understanding how RPP29 binds to M1GS RNA and enhances the enzyme's catalytic activity will provide great insight into developing more robust gene-targeting ribozymes for in vivo application. In this chapter, we describe the methods of using Fe(II)-ethylenediaminetetraacetic acid (EDTA) cleavage and nuclease footprint analyses to determine the regions of a M1GS ribozyme that are in proximity to RPP29 protein.

Targeted Treatment against Lipoprotein (a): The Coming Breakthrough in Lipid Lowering Therapy

Atherosclerotic cardiovascular diseases (ASCVD) are a very important cause of premature death. The most important risk factor for ASCVD is lipid disorders. The incidence of lipid disorders and ASCVD is constantly increasing, which means that new methods of prevention and treatment of these diseases are still being searched for. In the management of patients with lipid disorders, the primary goal of therapy is to lower the serum LDL-C concentration. Despite the available effective lipid-lowering therapies, the risk of ASCVD is still increased in some patients. A high level of serum lipoprotein (a) (Lp(a)) is a risk factor for ASCVD independent of serum LDL-C concentration. About 20% of Europeans have elevated serum Lp(a) levels, requiring treatment to reduce serum Lp(a) concentrations in addition to LDL-C. Currently available lipid lowering drugs do not sufficiently reduce serum Lp(a) levels. Hence, drugs based on RNA technology, such as pelacarsen, olpasiran, SLN360 and LY3819469, are undergoing clinical trials. These drugs are very effective in lowering the serum Lp(a) concentration and have a satisfactory safety profile, which means that in the near future they will fill an important gap in the armamentarium of lipid-lowering drugs.

Nucleic Acid Delivery to the Vascular Endothelium

This Review examines the state-of-the-art in the delivery of nucleic acid therapies that are directed to the vascular endothelium. First, we review the most important homeostatic functions and properties of the vascular endothelium and summarize the nucleic acid tools that are currently available for gene therapy and nucleic acid delivery. Second, we consider the opportunities available with the endothelium as a therapeutic target and the experimental models that exist to evaluate the potential of those opportunities. Finally, we review the progress to date from investigations that are directly targeting the vascular endothelium: for vascular disease, for peri-transplant therapy, for angiogenic therapies, for pulmonary endothelial disease, and for the blood-brain barrier, ending with a summary of the future outlook in this field.

Tellurium-Modified Nucleosides, Nucleotides, and Nucleic Acids with Potential Applications

Tellurium was successfully incorporated into proteins and applied to protein structure determination through X-ray crystallography. However, studies on tellurium modification of DNA and RNA are limited. This review highlights the recent development of Te-modified nucleosides, nucleotides, and nucleic acids, and summarizes the main synthetic approaches for the preparation of 5-PhTe, 2'-MeTe, and 2'-PhTe modifications. Those modifications are compatible with solid-phase synthesis and stable during Te-oligonucleotide purification. Moreover, the ideal electronic and atomic properties of tellurium for generating clear isomorphous signals give Te-modified DNA and RNA great potential applications in 3D crystal structure determination through X-ray diffraction. STM study also shows that Te-modified DNA has strong topographic and current peaks, which immediately suggests potential applications in nucleic acid direct imaging, nanomaterials, molecular electronics, and diagnostics. Theoretical studies indicate the potential application of Te-modified nucleosides in cancer therapy.

Extracellular Vesicles and Their Roles in the Tumor Immune Microenvironment

Tumor cells actively incorporate molecules (e.g., proteins, lipids, RNA) into particles named extracellular vesicles (EVs). Several groups have demonstrated that EVs can be transferred to target (recipient) cells, making EVs an important means of intercellular communication. Indeed, EVs are able to modulate the functions of target cells by reprogramming signaling pathways. In a cancer context, EVs promote the formation of a supportive tumor microenvironment (TME) and (pre)metastatic niches. Recent studies have revealed that immune cells, tumor cells and their secretome, including EVs, promote changes in the TME and immunosuppressive functions of immune cells (e.g., natural killer, dendritic cells, T and B cells, monocytes, macrophages) that allow tumor cells to establish and propagate. Despite the growing knowledge on EVs and on their roles in cancer and as modulators of the immune response/escape, the translation into clinical practice remains in its early stages, hence requiring improved translational research in the EVs field. Here, we comprehensively review the current knowledge and most recent research on the roles of EVs in tumor immune evasion and immunosuppression in both solid tumors and hematological malignancies. We also highlight the clinical utility of EV-mediated immunosuppression targeting and EV-engineering. Importantly, we discuss the controversial role of EVs in cancer biology, current limitations and future perspectives to further the EV knowledge into clinical practice.

Preparation, characterization, and in-vitro cytotoxicity of nanoliposomes loaded with anti-tubercular drugs and TGF-β1 siRNA for improving spinal tuberculosis therapy

Background

Tuberculosis (TB) represents a bacterial infection affecting many individuals each year and potentially leading to death. Overexpression of transforming growth factor (TGF)-β1 has a primary immunomodulatory function in human tuberculosis. This work aimed to develop nanoliposomes to facilitate the delivery of anti-tubercular products to THP-1-derived human macrophages as Mycobacterium host cells and to evaluate drug efficiencies as well as the effects of a TGF-β1-specific short interfering RNA (siRNA) delivery system employing nanoliposomes.

Methods

In the current study, siTGF-β1 nanoliposomes loaded with the anti-TB drugs HRZ (isoniazid, rifampicin, and pyrazinamide) were prepared and characterized in vitro, determining the size, zeta potential, morphology, drug encapsulation efficiency (EE), cytotoxicity, and gene silencing efficiency of TGF-β1 siRNA.

Results

HRZ/siTGF-β1 nanoliposomes appeared as smooth spheres showing the size and positive zeta potential of 168.135 ± 0.5444 nm and + 4.03 ± 1.32 mV, respectively. Drug EEs were 90%, 88%, and 37% for INH, RIF, and PZA, respectively. Meanwhile, the nanoliposomes were weakly cytotoxic towards human macrophages as assessed by the MTT assay. Nanoliposomal siTGF-β1 could significantly downregulate TGF-β1 in THP-1-derived human macrophages in vitro.

Conclusion

These findings suggested that HRZ-loaded nanoliposomes with siTGF-β1 have the potential for improving spinal tuberculosis chemotherapy via nano-encapsulation of anti-TB drugs.

A perspective on oligonucleotide therapy: Approaches to patient customization

It is estimated that the human genome encodes 15% of proteins that are considered to be disease-modifying. Only 2% of these proteins possess a druggable site that the approved clinical candidates target. Due to this disparity, there is an immense need to develop therapeutics that may better mitigate the disease or disorders aroused by non-druggable and druggable proteins or enzymes. The recent surge in approved oligonucleotide therapeutics (OT) indicates the imminent potential of these therapies. Oligonucleotide-based therapeutics are of intermediate size with much-improved selectivity towards the target and fewer off-target effects than small molecules. The OTs include Antisense RNAs, MicroRNA (MIR), small interfering RNA (siRNA), and aptamers, which are currently being explored for their use in neurodegenerative disorders, cancer, and even orphan diseases. The present review is a congregated effort to present the past and present of OTs and the current efforts to make OTs for plausible future therapeutics. The review provides updated literature on the challenges and bottlenecks of OT and recent advancements in OT drug delivery. Further, this review deliberates on a newly emerging approach to personalized treatment for patients with rare and fatal diseases with OT.

miR-146a-5p-modified hUCMSC-derived exosomes facilitate spinal cord function recovery by targeting neurotoxic astrocytes

Background

Acute spinal cord injury (SCI) is a devastating result of neurological trauma with subsequent microenvironment dyshomeostasis that induces neurotoxic phenotype acquisition by astrocytes, exacerbating neurological function impairment. Exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSCs) have demonstrated essential therapeutic effects after central nervous system trauma. However, whether hUCMSC-derived exosomes exert therapeutic effects on neurotoxic astrocytes to facilitate SCI function recovery remains unclear. Additionally, the limited efficiency of single exosomes may restrict the optimization of exosomal biological functions.

Methods

We first determined that exosomes reduce the deleterious effects of neurotoxic astrocytes in vitro and in vivo. Then, we identified critical functional microRNAs (miRNAs). miR-146a-5p was overexpressed in exosomes, and then, miR-146a-5p-modified exosomes were used to investigate the ability of exosomes to reduce neurotoxic astrocyte effects, preserve neurons and promote neurological function recovery in rats with SCI.

Results

Cell counting kit-8 and neurite length analyses revealed that exosomes partially reduced the negative effects of neurotoxic astrocytes on PC12 cell viability and neurites in vitro. The exosomes also attenuated inflammatory responses, reduced the number of neurotoxic astrocytes and preserved neural tissue in rats with SCI. Immunofluorescence assays suggested that the number of neurotoxic astrocytes was rapidly increased by injury, reaching a peak 5 days post-injury (dpi) and returning to the normal level 14dpi. Exosomal miR-146a-5p was identified as the critical functional miRNA. Overexpression of miR-146a-5p in exosomes strengthened the biological function of the exosomes. Therefore, the modified exosomes exerted more powerful therapeutic effects than the unmodified exosomes, reducing the deleterious effects of neurotoxic astrocytes both in vitro and in vivo and promoting locomotor function of the hindlimbs in the rats with SCI. Through a series of gain- and loss-of-function experiments, Traf6 and Irak1 were identified as targets of exosomal miR-146a-5p. Ultimately, we found that miR-146a-5p-modified exosomes exerted their function by targeting Traf6/Irak1/NFκB pathway in neurotoxic astrocytes.

Conclusions

In summary, miR-146a-5p-modified exosomes exerted a more powerful effect than unmodified exosomes to promote neurological function recovery in rats with SCI by targeting neurotoxic astrocytes. Therefore, miR-146a-5p-modified exosomes are promising therapeutics for SCI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03116-3.

Application of vinyl polymer-based materials as nucleic acids carriers in cancer therapy

Nucleic acid-based therapies have changed the paradigm of cancer treatment, where conventional treatment modalities still have several limitations in terms of efficacy and severe side effects. However, these biomolecules have a short half-life in vivo, requiring multiple administrations, resulting in severe suffering, discomfort, and poor patient compliance. In the early days of (nano)biotechnology, these problems caused concern in the medical community, but recently it has been recognized that these challenges can be overcome by developing innovative formulations. This review focuses on the use of vinyl polymer-based materials for the protection and delivery of nucleic acids in cancer. First, an overview of the properties of nucleic acids and their versatility as drugs is provided. Then, key information on the achievements to date, the most effective delivery methods, and the evaluation of functionalization approaches (stimulatory strategies) are critically discussed to highlight the importance of vinyl polymers in the new cancer treatment approaches. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures.

Lipid Nanoparticles for mRNA Delivery to Enhance Cancer Immunotherapy

Messenger RNA (mRNA) is being developed by researchers as a novel drug for the treatment or prevention of many diseases. However, to enable mRNA to fully exploit its effects in vivo, researchers need to develop safer and more effective mRNA delivery systems that improve mRNA stability and enhance the ability of cells to take up and release mRNA. To date, lipid nanoparticles are promising nanodrug carriers for tumor therapy, which can significantly improve the immunotherapeutic effects of conventional drugs by modulating mRNA delivery, and have attracted widespread interest in the biomedical field. This review focuses on the delivery of mRNA by lipid nanoparticles for cancer treatment. We summarize some common tumor immunotherapy and mRNA delivery strategies, describe the clinical advantages of lipid nanoparticles for mRNA delivery, and provide an outlook on the current challenges and future developments of this technology.

Development and application of ribonucleic acid therapy strategies against COVID-19

The Coronavirus disease 2019 (COVID-19) pandemic is caused by the severe acute respiratory syndrome 2 coronavirus (SARS-CoV-2), remaining a global health crisis since its outbreak until now. Advanced biotechnology and research findings have revealed many suitable viral and host targets for a wide range of therapeutic strategies. The emerging ribonucleic acid therapy can modulate gene expression by post-transcriptional gene silencing (PTGS) based on Watson-Crick base pairing. RNA therapies, including antisense oligonucleotides (ASO), ribozymes, RNA interference (RNAi), aptamers, etc., were used to treat SARS-CoV whose genome is similar to SARV-CoV-2, and the past experience also applies for the treatment of COVID-19. Several studies against SARS-CoV-2 based on RNA therapeutic strategy have been reported, and a dozen of relevant preclinical or clinical trials are in process globally. RNA therapy has been a very active and important part of COVID-19 treatment. In this review, we focus on the progress of ribonucleic acid therapeutic strategies development and application, discuss corresponding problems and challenges, and suggest new strategies and solutions.

Applications of self-replicating RNA

Self-replicating RNA viral vectors have been engineered for both prophylactic and therapeutic applications. Mainly the areas of infectious diseases and cancer have been targeted. Both positive and negative strand RNA viruses have been utilized including alphaviruses, flaviviruses, measles viruses and rhabdoviruses. The high-level of RNA amplification has provided efficient expression of viral surface proteins and tumor antigens. Immunization studies in animal models have elicit robust neutralizing antibody responses. In the context of infectious diseases, immunization with self-replicating RNA viral vectors has provided protection against challenges with lethal doses of pathogens in animal models. Similarly, immunization with vectors expressing tumor antigens has resulted in tumor regression and eradication and protection against tumor challenges in animal models. The transient nature and non-integration of viral RNA into the host genome are ideal features for vaccine development. Moreover, self-replicating RNA viral vectors show great flexibility as they can be applied as recombinant viral particles, RNA replicons or DNA replicon plasmids. Several clinical trials have been conducted especially in the area of cancer immunotherapy.

Coaxial Synthesis of PEI-Based Nanocarriers of Encapsulated RNA-Therapeutics to Specifically Target Muscle Cells

In this work, we performed a methodological comparative analysis to synthesize polyethyleneimine (PEI) nanoparticles using (i) conventional nanoprecipitation (NP), (ii) electrospraying (ES), and (iii) coaxial electrospraying (CA). The nanoparticles transported antisense oligonucleotides (ASOs), either encapsulated (CA nanocomplexes) or electrostatically bound externally (NP and ES nanocomplexes). After synthesis, the PEI/ASO nanoconjugates were functionalized with a muscle-specific RNA aptamer. Using this combinatorial formulation methodology, we obtained nanocomplexes that were further used as nanocarriers for the delivery of RNA therapeutics (ASO), specifically into muscle cells. In particular, we performed a detailed confocal microscopy-based comparative study to analyze the overall transfection efficiency, the cell-to-cell homogeneity, and the mean fluorescence intensity per cell of micron-sized domains enriched with the nanocomplexes. Furthermore, using high-magnification electron microscopy, we were able to describe, in detail, the ultrastructural basis of the cellular uptake and intracellular trafficking of nanocomplexes by the clathrin-independent endocytic pathway. Our results are a clear demonstration that coaxial electrospraying is a promising methodology for the synthesis of therapeutic nanoparticle-based carriers. Some of the principal features that the nanoparticles synthesized by coaxial electrospraying exhibit are efficient RNA-based drug encapsulation, increased nanoparticle surface availability for aptamer functionalization, a high transfection efficiency, and hyperactivation of the endocytosis and early/late endosome route as the main intracellular uptake mechanism.

CD33 ‐targeting extracellular vesicles deliver antisense oligonucleotides against FLT3‐ITD and miR ‐125b for specific treatment of acute myeloid leukaemia

Introduction

Acute Myeloid Leukaemia (AML) is the most common blood cancer in adults. Although 2 out of 3 AML patients go into total remission after chemotherapies and targeted therapies, the disease recurs in 60%–65% of younger adult patients within 3 years after diagnosis with a dramatically decreased survival rate. Therapeutic oligonucleotides are promising treatments under development for AML as they can be designed to silence oncogenes with high specificity and flexibility. However, there are not many well validated approaches for safely and efficiently delivering oligonucleotide drugs. This issue could be resolved by utilizing a new generation of delivery vehicles such as extracellular vesicles (EVs).

Methods

In this study, we harness red blood cell‐derived EVs (RBCEVs) and engineer them via exogenous drug loading and surface functionalization to develop an efficient drug delivery system for AML. Particularly, EVs are designed to target CD33, a common surface marker with elevated expression in AML cells via the conjugation of a CD33‐binding monoclonal antibody onto the EV surface.

Results

The conjugation of RBCEVs with the CD33‐binding antibody significantly increases the uptake of RBCEVs by CD33‐positive AML cells, but not by CD33‐negative cells. We also load CD33‐targeting RBCEVs with antisense oligonucleotides (ASOs) targeting FLT3‐ITD or miR‐125b, 2 common oncogenes in AML, and demonstrate that the engineered EVs improve leukaemia suppression in in vitro and in vivo models of AML.

Conclusion

Targeted RBCEVs represent an innovative, efficient, and versatile delivery platform for therapeutic ASOs and can expedite the clinical translation of oligonucleotide drugs for AML treatments by overcoming current obstacles in oligonucleotide delivery.

Enriching Proteolysis Targeting Chimeras with a Second Modality: When Two Are Better Than One

Proteolysis targeting chimera (PROTAC)-mediated protein degradation has prompted a radical rethink and is at a crucial stage in driving a drug discovery transition. To fully harness the potential of this technology, a growing paradigm toward enriching PROTACs with other therapeutic modalities has been proposed. Could researchers successfully combine two modalities to yield multifunctional PROTACs with an expanded profile? In this Perspective, we try to answer this question. We discuss how this possibility encompasses different approaches, leading to multitarget PROTACs, light-controllable PROTACs, PROTAC conjugates, and macrocycle- and oligonucleotide-based PROTACs. This possibility promises to further enhance PROTAC efficacy and selectivity, minimize side effects, and hit undruggable targets. While PROTACs have reached the clinical investigation stage, additional steps must be taken toward the translational development of multifunctional PROTACs. A deeper and detailed understanding of the most critical challenges is required to fully exploit these opportunities and decisively enrich the PROTAC toolbox.

Antisense Oligonucleotides and Small Interfering RNA for the Treatment of Dyslipidemias

The burden of atherosclerotic disease worldwide necessitates implementing the treatment of its risk factors. Among them, hypercholesterolemia has a central role. In addition to conventional small organic compounds and the recently introduced monoclonal antibodies, new technologies are arising such as the antisense oligonucleotides and small interfering RNAs (siRNAs) that operate upstream, blocking the mRNA translation of the proteins specifically involved in lipid metabolism. In this review, we briefly explain the mechanisms of action of these molecules and discuss the difficulties related to their in vivo use as therapeutical agents. We go over the oligonucleotides tested in clinical trials that could potentially revolutionize the care of patients by acting on proteins involved in the lipoprotein metabolism and regulation, namely: angiopoietin-like protein 3 (ANGPTL3); lipoprotein a (Lp(a)); apolipoprotein B (Apo B); apolipoprotein C III (Apo C-III); and proprotein convertase subtilisin–kexin type 9 (PCSK9). Finally, the differences between ASOs and siRNAs, their future possible clinical applications, and the role of Inclisiran, a siRNA direct against PCSK9 to reduce LDL-C, were reviewed in detail.