Current prospects for RNA interference-based therapies

RNA interference in Pardosa pseudoannulata, an important predatory enemy against several insect pests, through ingestion of dsRNA-expressing Escherichia coli

RNA interference is an important technology for gene functional research in many organisms. The pond wolf spider (Pardosa pseudoannulata) is an important natural enemy of rice field pests. To facilitate large-scale gene functional research in this spider species and others, we developed an RNA interference (RNAi) method via ingestion of bacteria expressing dsRNA. The dsRNA targeting a cytochrome P450 monooxygenase (cyp41g2) was expressed in Escherichia coli HT115 (DE3). And then the bacterial suspension was fed to 14-20 days old spiderlings. The mRNA abundance of the target gene was significantly reduced after 3-day's ingestion of bacteria expressing dsRNA, and between day 5 and 7, RNAi efficiency remained stable. Thus, we selected 5 days as the optimum interference time. Furthermore, the bacteria resuspension containing 20 ng/μl dsRNA was selected as the optimum concentration. To evaluate the applicability of this method, three other genes with different tissue expression pattern were also selected as targets. And the mRNA abundance of all the four target genes was significantly reduced with RNAi efficiency between 66.0% and up to 86.9%. The results demonstrated that the oral delivery of bacteria expressing dsRNA would be an effective RNAi method for the gene functional study in P. pseudoannulata.

Intercalation-Driven Formation of siRNA Nanogels for Cancer Therapy

RNA interference (RNAi) is a powerful approach in the treatment of various diseases including cancers. The clinical translation of small interfering RNA (siRNA)-based therapy requires safe and efficient delivery vehicles. Here, we report a siRNA nanogels (NG)-based delivery vehicle, which is driven directly by the intercalation between nucleic acid bis-intercalator and siRNA molecules. The intercalation-based siRNA NG exhibits good physiological stability and can enter cells efficiently via different endocytosis pathways. Furthermore, the siRNA NG can not only silence the target genes in vitro but also significantly inhibit the tumor growth in vivo. Therefore, this study provides an intercalation-based strategy for the development of a siRNA delivery platform for cancer therapy. To the best of our knowledge, this is the first report of the intercalation-driven siRNA NG.

Efficient and Precise Processing of the Optimized Pri-amiRNA in a Huntingtin-Lowering AAV Gene Therapy in Vitro and in Mice and Nonhuman Primates

Huntington's Disease is a fatal neurodegenerative disorder caused by an inherited mutation in the huntingtin gene (HTT) comprising an expanded cytosine-adenine-guanine (CAG) trinucleotide repeat sequence that results in a pathogenic huntingtin protein. AAV gene therapy containing a primary artificial microRNA (pri-amiRNA) specifically targeting HTT mRNA has the potential to provide long-lasting therapeutic benefit, via durable reduction of mutant HTT expression after a single administration. The efficiency and precision of processing of the pri-amiRNA precursor to the mature guide strand by transduced cells is critical for specific and potent HTT lowering. The selection of the optimized pri-amiRNA comprised a series of in vitro studies followed by in vivo studies in small and then large mammals. Our studies demonstrate the predictivity of certain cell culture systems and rodent models for nonhuman primates (NHP) with respect to some, but not all key features of pri-amiRNA processing. In addition, our results show that the processing of pri-amiRNAs to the mature guide strand can differ greatly across different scaffolds and sequences while providing the same levels of target lowering. Importantly, our data demonstrate that there is a combinatorial effect of guide and passenger strand sequences, together with the scaffold, on pri-amiRNA processing, with different guide and passenger strand sequences within the same scaffold dramatically altering pri-amiRNA processing. Taken together, our results highlight the importance of optimizing not only target lowering, but also the efficiency and precision of pri-amiRNA processing in vitro, in rodents and in large mammals to identify the most potent and selective AAV gene therapy that harnesses the endogenous miRNA biogenesis pathway for target lowering without perturbing the endogenous cellular miRNA profile. The optimized pri-amiRNA was selected with this focus on efficiency and precision of pri-amiRNA processing in addition to its pharmacological activity on HTT lowering, and general tolerability in vivo.

Enzymatic ligation of an antibody and arginine 9 peptide for efficient and cell-specific siRNA delivery

A fusion protein comprising an antibody and a cationic peptide, such as arginine-9 (R9), is a candidate molecule for efficient and cell-specific delivery of siRNA into cells in order to reduce the side effects of nucleic acid drugs. However, their expression in bacterial hosts, required for their development, often fails, impeding research progress. In this study, we separately prepared anti-EGFR nanobodies with the K-tag sequence MRHKGS at the C-terminus and R9 with the Q-tag sequence LLQG at the N-terminus, and enzymatically ligated them in vitro by microbial transglutaminase to generate Nanobody-R9, which is not expressed as a fused protein in E. coli. Nanobody-R9 was synthesized at a maximum binding efficiency of 85.1%, without changing the binding affinity of the nanobody for the antigen. Nanobody-R9 successfully delivered siRNA into the cells, and the cellular influx of siRNA increased with increase in the ratio of Nanobody-R9 to siRNA. We further demonstrated that the Nanobody-R9-siRNA complex, at a 30:1 ratio, induced an approximately 58.6% reduction in the amount of target protein due to RNAi in mRNA compared to lipofectamine.

MicroRNAs affect GPCR and Ion channel genes needed for influenza replication

Influenza virus causes seasonal epidemics and sporadic pandemics resulting in morbidity, mortality, and economic losses worldwide. Understanding how to regulate influenza virus replication is important for developing vaccine and therapeutic strategies. Identifying microRNAs (miRs) that affect host genes used by influenza virus for replication can support an antiviral strategy. In this study, G-protein coupled receptor (GPCR) and ion channel (IC) host genes in human alveolar epithelial (A549) cells used by influenza virus for replication (Orr-Burks et al., 2021) were examined as miR target genes following A/CA/04/09- or B/Yamagata/16/1988 replication. Thirty-three miRs were predicted to target GPCR or IC genes and their miR mimics were evaluated for their ability to decrease influenza virus replication. Paired miR inhibitors were used as an ancillary measure to confirm or not the antiviral effects of a miR mimic. Fifteen miRs lowered influenza virus replication and four miRs were found to reduce replication irrespective of virus strain and type differences. These findings provide evidence for novel miR disease intervention strategies for influenza viruses.

MMV-db: vaccinomics and RNA-based therapeutics database for infectious hemorrhagic fever-causing mammarenaviruses

The recent viral outbreaks and the current pandemic situation urges us to timely address any emerging viral infections by designing therapeutic strategies. Multi-omics and therapeutic data are of great interest to develop early remedial interventions. This work provides a therapeutic data platform (Mammarenavirus (MMV)-db) for pathogenic mammarenaviruses with potential catastrophic effects on human health around the world. The database integrates vaccinomics and RNA-based therapeutics data for seven human pathogenic MMVs associated with severe viral hemorrhagic fever and lethality in humans. Protein-specific cytotoxic T lymphocytes, B lymphocytes, helper T-cell and interferon-inducing epitopes were mapped using a cluster of immune-omics-based algorithms and tools for the seven human pathogenic viral species. Furthermore, the physiochemical and antigenic properties were also explored to guide protein-specific multi-epitope subunit vaccine for each species. Moreover, highly efficacious RNAs (small Interfering RNA (siRNA), microRNA and single guide RNA (sgRNA)) after extensive genome-based analysis with therapeutic relevance were explored. All the therapeutic RNAs were further classified and listed on the basis of predicted higher efficacy. The online platform (http://www.mmvdb.dqweilab-sjtu.com/index.php) contains easily accessible data sets and vaccine designs with potential utility in further computational and experimental work. Conclusively, the current study provides a baseline data platform to secure better future therapeutic interventions against the hemorrhagic fever causing mammarenaviruses. Database URL: http://www.mmvdb.dqweilab-sjtu.com/index.php.

Block catiomer with flexible cationic segment enhances complexation with siRNA and the delivery performance in vitro

RNA interference (RNAi) by small interfering RNAs (siRNAs) is a promising therapeutic approach. Because siRNA has limited intracellular access and is rapidly cleared in vivo, the success of RNAi depends on efficient delivery technologies. Particularly, polyion complexation between block catiomers and siRNA is a versatile approach for constructing effective carriers, such as unit polyion complexes (uPIC), core-shell polyion complex (PIC) micelles and vesicular siRNAsomes, by engineering the structure of block catiomers. In this regard, the flexibility of block catiomers could be an important parameter in the formation of PIC nanostructures with siRNA, though its effect remains unknown. Here, we studied the influence of block catiomer flexibility on the assembly of PIC structures with siRNA using a complementary polymeric system, i.e. poly(ethylene glycol)-poly(L-lysine) (PEG-PLL) and PEG-poly(glycidylbutylamine) (PEG-PGBA), which has a relatively more flexible polycation segment than PEG-PLL. Mixing PEG-PGBA with siRNA at molar ratios of primary amines in polymer to phosphates in the siRNA (N/P ratios) higher than 1.5 promoted the multimolecular association of uPICs, whereas PEG-PLL formed uPIC at all N/P ratios higher than 1. Moreover, uPICs from PEG-PGBA were more stable against counter polyanion exchange than uPICs from PEG-PLL, probably due to a favorable complexation process, as suggested by computational studies of siRNA/block catiomer binding. In in vitro experiments, PEG-PGBA uPICs promoted effective intracellular delivery of siRNA and efficient gene knockdown. Our results indicate the significance of polycation flexibility on assembling PIC structures with siRNA, and its potential for developing innovative delivery systems.

Folate targeted hybrid lipo-polymeric nanoplexes containing docetaxel and miRNA-34a for breast cancer treatment

In spite of established evidence of the synergistic combination of hydrophobic anticancer molecule and microRNA for breast cancer treatment, their in vivo delivery has not been realized owing to their instability in the biological milieu and varied physicochemical properties. The present work reports folate targeted hybrid lipo-polymeric nanoplexes for co-delivering DTX and miR-34a. These nanoplexes exhibited a mean size of 129.3 nm with complexation efficiency at an 8:1 N/P ratio. The obtained nanoplexes demonstrated higher entrapment efficiency of DTX (94.8%) with a sustained release profile up to 85% till 48 h. Further, an improved transfection efficiency in MDA-MB-231 and 4T1 breast cancer cells was observed with uptake primarily through lipid-raft and clathrin-mediated endocytosis. Further, nanoplexes showed improved cytotoxicity (~3.5-5 folds), apoptosis (~1.6-2.0 folds), and change in expression of apoptotic genes (~4-7 folds) compared to the free treatment group in breast cancer cells. In vivo systemic administration of FA-functionalized DTX and FAM-siRNA-loaded nanoplexes showed an improved area under the curve (AUC) as well as circulation half-life compared to free DTX and naked FAM-labelled siRNA. Acute toxicity studies of the cationic polymer showed no toxicity at a dose equivalent to 10 mg/kg based on the hematological, biochemical, and histopathological examination.

shRNA transgenic swine display resistance to infection with the foot-and-mouth disease virus

Foot-and-mouth disease virus (FMDV) is one of the most important animal pathogens in the world. FMDV naturally infects swine, cattle, and other cloven-hoofed animals. FMD is not adequately controlled by vaccination. An alternative strategy is to develop swine that are genetically resistant to infection. Here, we generated FMDV-specific shRNA transgenic cells targeting either nonstructural protein 2B or polymerase 3D of FMDV. The shRNA-positive transgenic cells displayed significantly lower viral production than that of the control cells after infection with FMDV (P < 0.05). Twenty-three transgenic cloned swine (TGCS) and nine non-transgenic cloned swine (Non-TGCS) were produced by somatic cell nuclear transfer (SCNT). In the FMDV challenge study, one TGCS was completely protected, no clinical signs, no viremia and no viral RNA in the tissues, no non-structural antibody response, another one TGCS swine recovered after showing clinical signs for two days, whereas all of the normal control swine (NS) and Non-TGCS developed typical clinical signs, viremia and viral RNA was determined in the tissues, the non-structural antibody was determined, and one Non-TGCS swine died. The viral RNA load in the blood and tissues of the TGCS was reduced in both challenge doses. These results indicated that the TGCS displayed resistance to the FMDV infection. Immune cells, including CD3⁺, CD4⁺, CD8⁺, CD21⁺, and CD172⁺ cells, and the production of IFN-γ were analyzed, there were no significant differences observed between the TGCS and NS or Non-TGCS, suggesting that the FMDV resistance may be mainly derived from the RNAi-based antiviral pathway. Our work provides a foundation for a breeding approach to preventing infectious disease in swine.

Scalable mRNA and siRNA Lipid Nanoparticle Production Using a Parallelized Microfluidic Device

A major challenge to advance lipid nanoparticles (LNPs) for RNA therapeutics is the development of formulations that can be produced reliably across the various scales of drug development. Microfluidics can generate LNPs with precisely defined properties, but have been limited by challenges in scaling throughput. To address this challenge, we present a scalable, parallelized microfluidic device (PMD) that incorporates an array of 128 mixing channels that operate simultaneously. The PMD achieves a >100× production rate compared to single microfluidic channels, without sacrificing desirable LNP physical properties and potency typical of microfluidic-generated LNPs. In mice, we show superior delivery of LNPs encapsulating either Factor VII siRNA or luciferase-encoding mRNA generated using a PMD compared to conventional mixing, with a 4-fold increase in hepatic gene silencing and 5-fold increase in luciferase expression, respectively. These results suggest that this PMD can generate scalable and reproducible LNP formulations needed for emerging clinical applications, including RNA therapeutics and vaccines.

In vivo self-assembled small RNAs as a new generation of RNAi therapeutics

RNAi therapy has undergone two stages of development, direct injection of synthetic siRNAs and delivery with artificial vehicles or conjugated ligands; both have not solved the problem of efficient in vivo siRNA delivery. Here, we present a proof-of-principle strategy that reprogrammes host liver with genetic circuits to direct the synthesis and self-assembly of siRNAs into secretory exosomes and facilitate the in vivo delivery of siRNAs through circulating exosomes. By combination of different genetic circuit modules, in vivo assembled siRNAs are systematically distributed to multiple tissues or targeted to specific tissues (e.g., brain), inducing potent target gene silencing in these tissues. The therapeutic value of our strategy is demonstrated by programmed silencing of critical targets associated with various diseases, including EGFR/KRAS in lung cancer, EGFR/TNC in glioblastoma and PTP1B in obesity. Overall, our strategy represents a next generation RNAi therapeutics, which makes RNAi therapy feasible.

The potential role of miRNA therapies in spinal muscle atrophy

Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by low levels of full-length survival motor neuron (SMN) protein due to the loss of the survival motor neuron 1 (SMN1) gene and inefficient splicing of the survival motor neuron 2 (SMN2) gene, which mostly affects alpha motor neurons of the lower spinal cord. Despite the U.S. Food and Drug Administration (FDA) approved SMN-dependent therapies including Nusinersen, Zolgensma® and Evrysdi™, SMA is still a devastating disease as these existing expensive drugs may not be sufficient and thus, remains a need for additional therapies. The involvement of microRNAs (miRNAs) in SMA is expanding because miRNAs are important mediators of gene expression as each miRNA could target a number of genes. Hence, miRNA-based therapy could be utilized in treating this genetic disorder. However, the delivery of miRNAs into the target cells remains an obstacle in SMA, as there is no effective delivery system to date. This review highlights the potential strategies for intracellular miRNA delivery into target cells and current challenges in miRNA delivery. Furthermore, we provide the future prospects of miRNA-based therapeutic strategies in SMA.

The reversal of chemotherapy-induced multidrug resistance by nanomedicine for cancer therapy

Multidrug resistance (MDR) of cancer is a persistent problem in chemotherapy. Scientists have considered the overexpressed efflux transporters responsible for MDR and chemotherapy failure. MDR extremely limits the therapeutic effect of chemotherapy in cancer treatment. Many strategies have been applied to solve this problem. Multifunctional nanoparticles may be one of the most promising approaches to reverse MDR of tumor. These nanoparticles can keep stability in the blood circulation and selectively accumulated in the tumor microenvironment (TME) either by passive or active targeting. The stimuli-sensitive or organelle-targeting nanoparticles can release the drug at the targeted-site without exposure to normal tissues. In order to better understand reversal of MDR, three main strategies are concluded in this review. First strategy is the synergistic effect of chemotherapeutic drugs and ABC transporter inhibitors. Through directly inhibiting overexpressed ABC transporters, chemotherapeutic drugs can enter into resistant cells without being efflux. Second strategy is based on nanoparticles circumventing over-expressed efflux transporters and directly targeting resistance-related organelles. Third approach is the combination of multiple therapy modes overcoming cancer resistance. At last, numerous researches demonstrated cancer stem-like cells (CSCs) had a deep relation with drug resistance. Here, we discuss two different drug delivery approaches of nanomedicine based on CSC therapy.

NEAT1 siRNA Packed with Chitosan Nanoparticles Regulates the Development of Colon Cancer Cells via lncRNA NEAT1/miR-377-3p Axis

This study was for verifying that transfecting colon cancer cells (CCCs) with lncRNA NEAT1 packed with siRNA chitosan nanoparticles (CNPs) can suppress lncRNA NEAT1 and biological behaviors of the cells. siRNA targeting lncRNA NEAT1 expression vector was constructed and then transfected into CCCs after being packed with CNPs. Subsequently, the impact of the transfection on biological behaviors of the cells was evaluated. As a result, with high expression in CCCs, NEAT1 was negatively bound up with miR-377-3p in cases with colon cancer (CC), and dual luciferase reporter assay confirmed the potential binding region. Additionally, after downregulating NEAT1 in CCCs, transfection of NEAT1 siRNA packed with CNPs brought a great inhibition on cell proliferation and a promotion on apoptosis, and inhibiting miR-377-3p was able to offset the role of silencing NEAT1 in CCCs. Therefore, in our opinion, NEAT1 siRNA packed with CNPs can hinder the growth and metastasis of CCCs by knocking down NEAT1 in CC, and its mechanism may be achieved by targeting miR-377-3p, which offers a novel direction for treating CC.

Cytosolic delivery of nucleic acids: The case of ionizable lipid nanoparticles

Ionizable lipid nanoparticles (LNPs) are the most clinically advanced nano-delivery system for therapeutic nucleic acids. The great effort put in the development of ionizable lipids with increased in vivo potency brought LNPs from the laboratory benches to the FDA approval of patisiran in 2018 and the ongoing clinical trials for mRNA-based vaccines against SARS-CoV-2. Despite these success stories, several challenges remain in RNA delivery, including what is known as "endosomal escape." Reaching the cytosol is mandatory for unleashing the therapeutic activity of RNA molecules, as their accumulation in other intracellular compartments would simply result in efficacy loss. In LNPs, the ability of ionizable lipids to form destabilizing non-bilayer structures at acidic pH is recognized as the key for endosomal escape and RNA cytosolic delivery. This is motivating a surge in studies aiming at designing novel ionizable lipids with improved biodegradation and safety profiles. In this work, we describe the journey of RNA-loaded LNPs across multiple intracellular barriers, from the extracellular space to the cytosol. In silico molecular dynamics modeling, in vitro high-resolution microscopy analyses, and in vivo imaging data are systematically reviewed to distill out the regulating mechanisms underlying the endosomal escape of RNA. Finally, a comparison with strategies employed by enveloped viruses to deliver their genetic material into cells is also presented. The combination of a multidisciplinary analytical toolkit for endosomal escape quantification and a nature-inspired design could foster the development of future LNPs with improved cytosolic delivery of nucleic acids.

Microneedles in Smart Drug Delivery

Significance: In biomedical setup, at large, and drug delivery, in particular, transdermal patches, hypodermal needles, and/or dermatological creams with the topical appliance are among the most widely practiced routes for transdermal drug delivery. Owing to the stratum corneum layer of the skin, traditional drug delivery methods are inefficient, and the effect of the administered therapeutic cues is limited. Recent Advances: The current advancement at the microlevel and nanolevel has revolutionized the drug delivery sector. Particularly, various types of microneedles (MNs) are becoming popular for drug delivery applications because of safety, patient compliance, and smart action. Critical Issues: Herein, we reviewed state-of-the-art MNs as a smart and sophisticated drug delivery approach. Following a brief introduction, the drug delivery mechanism of MNs is discussed. Different types of MNs, that is, solid, hollow, coated, dissolving, and hydrogel forming, are discussed with suitable examples. The latter half of the work is focused on the applied perspective and clinical translation of MNs. Furthermore, a detailed overview of clinical applications and future perspectives is also included in this review. Future Directions: Regardless of ongoing technological and clinical advancement, the focus should be diverted to enhance the efficacy and strength of MNs. Besides, the possible immune response or interference should also be avoided for successful clinical translation of MNs as an efficient drug delivery system.

Could gene therapy cure HIV?

The Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) continues to be a major global public health issue, having claimed almost 33 million lives so far. According to the recent report of the World Health Organization (WHO) in 2019, about 38 million people are living with AIDS. Hence, finding a solution to overcome this life-threatening virus can save millions of lives. Scientists and medical doctors have prescribed HIV patients with specific drugs for many years. Methods such antiretroviral therapy (ART) or latency-reversing agents (LRAs) have been used for a while to treat HIV patients, however they have some side effects and drawbacks causing their application to be not quite successful. Instead, the application of gene therapy which refers to the utilization of the therapeutic delivery of nucleic acids into a patient's cells as a drug to treat disease has shown promising results to control HIV infection. Therefore, in this review, we will summarize recent advances in gene therapy approach against HIV.

RNA Interference Strategies for Future Management of Plant Pathogenic Fungi: Prospects and Challenges

Plant pathogenic fungi are the largest group of disease-causing agents on crop plants and represent a persistent and significant threat to agriculture worldwide. Conventional approaches based on the use of pesticides raise social concern for the impact on the environment and human health and alternative control methods are urgently needed. The rapid improvement and extensive implementation of RNA interference (RNAi) technology for various model and non-model organisms has provided the initial framework to adapt this post-transcriptional gene silencing technology for the management of fungal pathogens. Recent studies showed that the exogenous application of double-stranded RNA (dsRNA) molecules on plants targeting fungal growth and virulence-related genes provided disease attenuation of pathogens like Botrytis cinerea, Sclerotinia sclerotiorum and Fusarium graminearum in different hosts. Such results highlight that the exogenous RNAi holds great potential for RNAi-mediated plant pathogenic fungal disease control. Production of dsRNA can be possible by using either in-vitro or in-vivo synthesis. In this review, we describe exogenous RNAi involved in plant pathogenic fungi and discuss dsRNA production, formulation, and RNAi delivery methods. Potential challenges that are faced while developing a RNAi strategy for fungal pathogens, such as off-target and epigenetic effects, with their possible solutions are also discussed.

Emerging role of RNA interference in immune cells engineering and its therapeutic synergism in immunotherapy

RNAi effectors (e.g. siRNA, shRNA and miRNA) can trigger the silencing of specific genes causing alteration of genomic functions becoming a new therapeutic area for the treatment of infectious diseases, neurodegenerative disorders and cancer. In cancer treatment, RNAi effectors showed potential immunomodulatory actions by down-regulating immuno-suppressive proteins, such as PD-1 and CTLA-4, which restrict immune cell function and present challenges in cancer immunotherapy. Therefore, compared with extracellular targeting by antibodies, RNAi-mediated cell-intrinsic disruption of inhibitory pathways in immune cells could promote an increased anti-tumour immune response. Along with non-viral vectors, DNA-based RNAi strategies might be a more promising method for immunomodulation to silence multiple inhibitory pathways in T cells than immune checkpoint blockade antibodies. Thus, in this review, we discuss diverse RNAi implementation strategies, with recent viral and non-viral mediated RNAi synergism to immunotherapy that augments the anti-tumour immunity. Finally, we provide the current progress of RNAi in clinical pipeline.

Chitosan-Based Nanoparticles Against Viral Infections

Viral infections, in addition to damaging host cells, can compromise the host immune system, leading to frequent relapse or long-term persistence. Viruses have the capacity to destroy the host cell while liberating their own RNA or DNA in order to replicate within additional host cells. The viral life cycle makes it challenging to develop anti-viral drugs. Nanotechnology-based approaches have been suggested to deal effectively with viral diseases, and overcome some limitations of anti-viral drugs. Nanotechnology has enabled scientists to overcome the challenges of solubility and toxicity of anti-viral drugs, and can enhance their selectivity towards viruses and virally infected cells, while preserving healthy host cells. Chitosan is a naturally occurring polymer that has been used to construct nanoparticles (NPs), which are biocompatible, biodegradable, less toxic, easy to prepare, and can function as effective drug delivery systems (DDSs). Furthermore, chitosan is Generally Recognized as Safe (GRAS) by the US Food and Drug Administration (U.S. FDA). Chitosan NPs have been used in drug delivery by the oral, ocular, pulmonary, nasal, mucosal, buccal, or vaginal routes. They have also been studied for gene delivery, vaccine delivery, and advanced cancer therapy. Multiple lines of evidence suggest that chitosan NPs could be used as new therapeutic tools against viral infections. In this review we summarize reports concerning the therapeutic potential of chitosan NPs against various viral infections.

The growth of siRNA-based therapeutics: Updated clinical studies

More than two decades after the natural gene-silencing mechanism of RNA interference was elucidated, small interfering RNA (siRNA)-based therapeutics have finally broken into the pharmaceutical market. With three agents already approved and many others in advanced stages of the drug development pipeline, siRNA drugs are on their way to becoming a standard modality of pharmacotherapy. The majority of late-stage candidates are indicated for rare or orphan diseases, whose patients have an urgent need for novel and effective therapies. Additionally, there are agents that have the potential to meet the need of a broader population. Inclisiran, for instance, is being developed for hypercholesterolemia and has shown benefit in patients who are uncontrolled even after maximal statin therapy. This review provides a brief overview of mechanisms of siRNA action, physiological barriers to its delivery and activity, and the most common chemical modifications and delivery platforms used to overcome these barriers. Furthermore, this review presents comprehensive profiles of the three approved siRNA drugs (patisiran, givosiran, and lumasiran) and the seven other siRNA candidates in Phase 3 clinical trials (vutrisiran, nedosiran, inclisiran, fitusiran, teprasiran, cosdosiran, and tivanisiran), summarizing their modifications and delivery strategies, disease-specific mechanisms of action, updated clinical trial status, and future outlooks.

Genetics and genomics of SARS-CoV-2: A review of the literature with the special focus on genetic diversity and SARS-CoV-2 genome detection

The outbreak of 2019-novel coronavirus disease (COVID-19), caused by SARS-CoV-2, started in late 2019; in a short time, it has spread rapidly all over the world. Although some possible antiviral and anti-inflammatory medications are available, thousands of people are dying daily. Well-understanding of the SARS-CoV-2 genome is not only essential for the development of new treatments/vaccines, but it also can be used for improving the sensitivity and specificity of current approaches for virus detection. Accordingly, we reviewed the most critical findings related to the genetics of the SARS-CoV-2, with a specific focus on genetic diversity and reported mutations, molecular-based diagnosis assays, using interfering RNA technology for the treatment of patients, and genetic-related vaccination strategies. Additionally, considering the unanswered questions or uncertainties in these regards, different topics were discussed.

Antitumor Activity of Small Activating RNAs Induced PAWR Gene Activation in Human Bladder Cancer Cells

Small double-stranded RNAs (dsRNAs) have been proved to effectively up-regulate the expression of particular genes by targeting their promoters. These small dsRNAs were also termed small activating RNAs (saRNAs). We previously reported that several small double-stranded RNAs (dsRNAs) targeting the PRKC apoptosis WT1 regulator (PAWR) promoter can up-regulate PAWR gene expression effectively in human cancer cells. The present study was conducted to evaluate the antitumor potential of PAWR gene induction by these saRNAs in bladder cancer. Promisingly, we found that up-regulation of PAWR by saRNA inhibited the growth of bladder cancer cells by inducing cell apoptosis and cell cycle arrest which was related to inhibition of anti‑apoptotic protein Bcl-2 and inactivation of the NF-κB and Akt pathways. The activation of the caspase cascade and the regulation of cell cycle related proteins also supported the efficacy of the treatment. Moreover, our study also showed that these saRNAs cooperated with cisplatin in the inhibition of bladder cancer cells. Overall, these data suggest that activation of PAWR by saRNA may have a therapeutic benefit for bladder cancer.

Polyamine-Functionalized 2'-Amino-LNA in Oligonucleotides: Facile Synthesis of New Monomers and High-Affinity Binding towards ssDNA and dsDNA

Attachment of cationic moieties to oligonucleotides (ONs) promises not only to increase the binding affinity of antisense ONs by reducing charge repulsion between the two negatively charged strands of a duplex, but also to augment their in vivo stability against nucleases. In this study, polyamine functionality was introduced into ONs by means of 2'-amino-LNA scaffolds. The resulting ONs exhibited efficient binding towards ssDNA, ssRNA and dsDNA targets, and the 2'-amino-LNA analogue carrying a triaminated linker showed the most pronounced duplex- and triplex-stabilizing effect. Molecular modelling revealed that favourable conformational and electrostatic effects led to salt-bridge formation between positively charged polyamine moieties and the Watson-Hoogsteen groove of the dsDNA targets, resulting in the observed triplex stabilization. All the investigated monomers showed increased resistance against 3'-nucleolytic digestion relative to the non-functionalized controls.

Advanced in developmental organic and inorganic nanomaterial: a review

With the unique properties such as high surface area to volume ratio, stability, inertness, ease of functionalization, as well as novel optical, electrical, and magnetic behaviors, nanomaterials have a wide range of applications in various fields with the common types including nanotubes, dendrimers, quantum dots, and fullerenes. With the aim of providing useful insights to help future development of efficient and commercially viable technology for large-scale production, this review focused on the science and applications of inorganic and organic nanomaterials, emphasizing on their synthesis, processing, characterization, and applications on different fields. The applications of nanomaterials on imaging, cell and gene delivery, biosensor, cancer treatment, therapy, and others were discussed in depth. Last but not least, the future prospects and challenges in nanoscience and nanotechnology were also explored.

Nanoparticles-assisted delivery of antiviral-siRNA as inhalable treatment for human respiratory viruses: A candidate approach against SARS-COV-2

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has challenged healthcare structures across the globe. Although a few therapies are approved by FDA, the search for better treatment options is continuously on rise. Clinical management includes infection prevention and supportive care such as supplemental oxygen and mechanical ventilatory support. Given the urgent nature of the pandemic and the number of companies and researchers developing COVID-19 related therapies, FDA has created an emergency program to move potential treatments with already approved drugs to patients as quickly as possible in parallel to the development of new drugs that must first pass the clinical trials. In this manuscript, we have reviewed the available literature on the use of sequence-specific degradation of viral genome using short-interfering RNA (siRNA) suggesting it as a possible treatment against SARS-CoV-2. Delivery of siRNA can be promoted by the use of FDA approved lipids, polymers or lipid-polymer hybrids. These nanoparticulate systems can be engineered to exhibit increased targetability and formulated as inhalable aerosols.

A Tubular DNA Nanodevice as a siRNA/Chemo-Drug Co-delivery Vehicle for Combined Cancer Therapy

Using the DNA origami technique, we constructed a DNA nanodevice functionalized with small interfering RNA (siRNA) within its inner cavity and the chemotherapeutic drug doxorubicin (DOX), intercalated in the DNA duplexes. The incorporation of disulfide bonds allows the triggered mechanical opening and release of siRNA in response to intracellular glutathione (GSH) in tumors to knockdown genes key to cancer progression. Combining RNA interference and chemotherapy, the nanodevice induced potent cytotoxicity and tumor growth inhibition, without observable systematic toxicity. Given its autonomous behavior, exceptional designability, potent antitumor activity and marked biocompatibility, this DNA nanodevice represents a promising strategy for precise drug design for cancer therapy.

The Effects of Single Nucleotide Polymorphisms in Cancer RNAi Therapies

Tremendous progress in RNAi delivery methods and design has allowed for the effective development of siRNA-based therapeutics that are currently under clinical investigation for various cancer treatments. This approach has the potential to revolutionize cancer therapy by providing the ability to specifically downregulate or upregulate the mRNA of any protein of interest. This exquisite specificity, unfortunately, also has a downside. Genetic variations in the human population are common because of the presence of single nucleotide polymorphisms (SNPs). SNPs lead to synonymous and non-synonymous changes and they occur once in every 300 base pairs in both coding and non-coding regions in the human genome. Much less common are the somatic mosaicism variations associated with genetically distinct populations of cells within an individual that is derived from postzygotic mutations. These heterogeneities in the population can affect the RNAi's efficacy or more problematically, which can lead to unpredictable and sometimes adverse side effects. From a more positive viewpoint, both SNPs and somatic mosaicisms have also been implicated in human diseases, including cancer, and these specific changes could offer the ability to effectively and, more importantly, selectively target the cancer cells. In this review, we discuss how SNPs in the human population can influence the development and success of novel anticancer RNAi therapies and the importance of why SNPs should be carefully considered.

Pyrazol-1-yl-propanamides as SARD and Pan-Antagonists for the Treatment of Enzalutamide-Resistant Prostate Cancer

We report herein the design, synthesis, and pharmacological characterization of a library of novel aryl pyrazol-1-yl-propanamides as selective androgen receptor degraders (SARDs) and pan-antagonists that exert broad-scope AR antagonism. Pharmacological evaluation demonstrated that introducing a pyrazole moiety as the B-ring structural element in the common A-ring-linkage-B-ring nonsteroidal antiandrogens' general pharmacophore allowed the development of a new scaffold of small molecules with unique SARD and pan-antagonist activities even compared to our recently published AF-1 binding SARDs such as UT-155 (9) and UT-34 (10). Novel B-ring pyrazoles exhibited potent AR antagonist activities, including promising distribution, metabolism, and pharmacokinetic properties, and broad-spectrum AR antagonist properties, including potent in vivo antitumor activity. 26a was able to induce an 80% tumor growth inhibition of xenografts derived from the enzalutamide-resistant (Enz-R) VCaP cell line. These results represent an advancement toward the development of novel AR antagonists for the treatment of Enz-R prostate cancer.

Lyophilization and nebulization of pulmonary surfactant-coated nanogels for siRNA inhalation therapy

RNA interference (RNAi) enables highly specific silencing of potential target genes for treatment of pulmonary pathologies. The intracellular RNAi pathway can be activated by cytosolic delivery of small interfering RNA (siRNA), inducing sequence-specific gene knockdown on the post-transcriptional level. Although siRNA drugs hold many advantages over currently applied therapies, their clinical translation is hampered by inefficient delivery across cellular membranes. We previously developed hybrid nanoparticles consisting of an siRNA-loaded nanosized hydrogel core (nanogel) coated with Curosurf®, a clinically used pulmonary surfactant (PS). The latter enhances both particle stability as well as intracellular siRNA delivery, which was shown to be governed by the PS-associated surfactant protein B (SP-B). Despite having a proven in vitro and in vivo siRNA delivery potential when prepared ex novo, clinical translation of this liquid nanoparticle suspension requires the identification of a long-term preservation strategy that maintains nanoparticle stability and potency. In addition, to achieve optimal pulmonary deposition of the nanocomposite, its compatibility with state-of-the-art pulmonary administration techniques should be evaluated. Here, we demonstrate that PS-coated nanogels can be lyophilized, reconstituted and subsequently nebulized via a vibrating mesh nebulizer. The particles retain their physicochemical integrity and their ability to deliver siRNA in a human lung epithelial cell line. The latter result suggests that the functional integrity of SP-B in the PS coat towards siRNA delivery might be preserved as well. Of note, successful lyophilization was achieved without the need for stabilizing lyo- or cryoprotectants. Our results demonstrate that PS-coated siRNA-loaded nanogels can be lyophilized, which offers the prospect of long-term storage. In addition, the formulation was demonstrated to be suitable for local administration with a state-of-the-art nebulizer for human use upon reconstitution. Hence, the data presented in this study represent an important step towards clinical application of such nanocomposites for treatment of pulmonary disease.

Effect of Confinement in Nanopores on RNA Interactions with Functionalized Mesoporous Silica Nanoparticles

Amine-functionalized mesoporous silica nanoparticles (MSNPAs) are ideal carriers for oligonucleotides for gene delivery and RNA interference. This investigation examines the thermodynamic driving force of interactions of double-stranded (ds) RNA with MSNPAs as a function of RNA length (84 and 282 base pair) and particle pore diameter (nonporous, 2.7, 4.3, and 8.1 nm) using isothermal titration calorimetry, extending knowledge of solution-based nucleic acid-polycation interactions to RNA confined in nanopores. Adsorption of RNA follows a two-step process: endothermic interactions driven by entropic contribution from counterion (and water) release and an exothermic regime dominated by short-range interactions within the pores. Evidence of hindered pore loading of the longer RNA and pore size-dependent confinement of RNA in the MSPAs is provided from the relative contributions of the endothermic and exothermic regimes. Reduction of endothermic and exothermic enthalpies in both regimes in the presence of salt for both lengths of RNA indicates the significant contribution of short-range electrostatic interactions, whereas ΔH and ΔG values are consistent with conformation changes and desolvation of nucleic acids upon binding with polycations. Knowledge of the interactions between RNA and functionalized porous nanoparticles will aid in porous nanocarrier design suitable for functional RNA delivery.

Targeted galectin-7 inhibition with ultrasound microbubble targeted gene therapy as a sole therapy to prevent acute rejection following heart transplantation in a Rodent model

BACKGROUND

Despite significant advances in transplantation, acute cellular rejection (AR) remains a major obstacle that is most prevalent in the first months post heart transplantation (HT). Current treatments require high doses of immunosuppressive drugs followed by maintenance therapies that have systemic side effects including early infection. In this study, we attempted to prevent AR with a myocardial-targeted galectin-7-siRNA delivery method using cationic microbubbles (CMBs) combined with ultrasound targeted microbubble destruction (UTMD) to create local immunosuppression in a rat abdominal heterotopic heart transplantation acute rejection model.

METHODS AND RESULTS

Galectin-7-siRNA (siGal-7) bound to CMBs were synthesized and effective ultrasound-targeted delivery of siGal-7 into target cells confirmed in vitro. Based on these observations, three transplant rat models were tested：①isograft (ISO); ② Allograft (ALLO) +UTMD; and ③ALLO + PBS. UTMD treatments were administered at 1, 3, 5, 7 days after HT. Galectin 7 expression was reduced by 50% compared to ALLO + PBS (p < 0.005), and this was associated with significant reductions in both galectin 7 and Interleukin-2 protein levels (p < 0.001). The ALLO + UTMD group had Grade II or less inflammatory infiltration and myocyte damage in 11/12 rats using International Society For Heart and Lung Transplantation grading, compared to 0/12 rats with this grading in the ALLO + PBS group at 10 days post HT (p < 0.001).

CONCLUSIONS

Ultrasound-targeted galectin-7-siRNA knockdown with UTMD can prevent acute cellular rejection in the early period after allograft heart transplantation without the need for systemic immunosuppression.

KEY WORDS

Microbubble, Acute Rejection, Heart Transplantation, Galectin-7, RNA.

Smart Nanocarriers for the Delivery of Nucleic Acid-Based Therapeutics: A Comprehensive Review

Nucleic acid-based therapies are promising therapeutics for the treatment of several systemic disorders, and they offer an exciting opportunity to address emerging biological challenges. The scope of nucleic acid-based therapeutics in the treatment of multiple disease states including cancers has been widened by recent progress in Ribonucleic acids (RNA) biology. However, cascades of systemic and intracellular barriers, including rapid degradation, renal clearance, and poor cellular uptake, hinder the clinical effectiveness of nucleic acid-based therapies. These barriers can be circumvented by utilizing advanced smart nanocarriers that efficiently deliver and release the encapsulated nucleic acids into the target tissues. This review describes the current status of clinical trials on nucleic acid-based therapeutics and highlights representative examples that provide an overview on the current and emerging trends in nucleic acid-based therapies. A better understanding of the design of advanced nanocarriers is essential to promote the translation of therapeutic nucleic acids into a clinical reality.

"Layer peeling" co-delivery system for enhanced RNA interference-based tumor associated macrophages-specific chemoimmunotherapy

RNA interference (RNAi)-based immunotherapy combined with chemotherapy has emerged as a promising therapeutic strategy for cancer treatment. The transport of siRNA and small molecular agents from the tumor vasculature to a separate therapeutic target has been impeded by multiple physiological barriers, which has restricted the development of RNAi-based chemoimmunotherapy. A nanotechnology-based co-delivery system was superior in improving the co-localization of gene and drug in the same tumor cell, while a co-delivery system for chemoimmunotherapy was expected to realize xenotype cell-targeting, which means delivering immunotherapy agents and chemotherapy drugs to immune cells and tumor cells, respectively. A multilayer structure co-delivery system was outstanding in crossing these barriers and targeting different cells in tumor tissue. Herein, a "layer peeling" co-delivery system (CDMPR) was developed with co-loaded IKKβ-siRNA and doxorubicin (DOX), in which IKKβ-siRNA was used for RNAi-based tumor associated macrophages (TAMs) polarization for immunotherapy and DOX was used for chemotherapy. A transwell assay in vitro and an immunofluorescence assay in Hepa1-6 tumor-bearing mice indicated that CDMPR exhibited a pH-sensitive disassembly ability in tumor tissue, IKKβ-siRNA was precisely delivered to M2-type TAMs and DOX was internalized into tumor cells. An M2-type TAMs polarization ability study of CDMPR demonstrated that M2-type TAMs could be polarized to M1-type TAMs by CDMPR in vitro and in vivo. In Hepa1-6 tumor-bearing mice, CDMPR exhibited improved antitumor efficiency with M2-type re-polarization ability by the precise delivery of IKKβ-siRNA and DOX to M2-type TAMs and tumor cells, respectively. Consequently, the combination of RNAi-based TAMs polarization and chemotherapy by the "layer peeling" co-delivery system would achieve an enhanced chemoimmunotherapy effect, which provides a novel strategy to improve cancer therapeutic effects.

Small Interfering RNAs and RNA Therapeutics in Cardiovascular Diseases

Ribonucleic acid (RNA) is being exploited and understood in its many aspects of function and structure for development of valuable tools in the therapeutics of various diseases such as cardiovascular etc. The expanded knowledge regarding function of RNA in the genomics and inside the cell has dramatically changed the therapeutic strategies in the past few years. RNA has become a spotlight of attention for developing novel therapeutic schemes and hence variety of therapeutic strategies is being coming into the picture that includes RNA interference, use of aptamers, role of microRNA (miRNA) that can alter the complex gene expression patterns. It is due to the fact that RNA offers various advantages in disease management as it can be edited and modified in its various forms such as secondary and tertiary structures. Although scientists are in process of manufacturing RNA-targeting therapies using variety of endogenous gene silencing regulators, Small interfering RNAs (Si RNAs), aptamers and microRNA for cardiovascular diseases yet the development of a novel, risk free therapeutic strategy is a major challenge and need of the hour in cardiovascular medicine. In this regard these agents are required to overcome pleothra of barriers such as stability of drug targets, immunogenicity, adequate binding, targeted delivery etc. to become effective drugs. Recent years have witnessed the progress of RNA therapeutic strategies in cardiovascular diseases that are likely to significantly expand the cardiovascular therapeutic repertoire within the next decade. The present manuscript has been compiled to summarize various approaches of siRNA based therapies in cardiovascular diseases along with the advantages, outcomes and limitations if any in this regard. In addition, the future prospects of RNA therapeutic modalities in cardiovascular diseases are summarized.

Use of DAMPs and SAMPs as Therapeutic Targets or Therapeutics: A Note of Caution

This opinion article discusses the increasing attention paid to the role of activating damage-associated molecular patterns (DAMPs) in initiation of inflammatory diseases and suppressing/inhibiting DAMPs (SAMPs) in resolution of inflammatory diseases and, consequently, to the future roles of these novel biomarkers as therapeutic targets and therapeutics. Since controlled production of DAMPs and SAMPs is needed to achieve full homeostatic restoration and repair from tissue injury, only their pathological, not their homeostatic, concentrations should be therapeutically tackled. Therefore, distinct caveats are proposed regarding choosing DAMPs and SAMPs for therapeutic purposes. For example, we discuss the need to a priori identify and define a context-dependent “homeostatic DAMP:SAMP ratio” in each case and a “homeostatic window” of DAMP and SAMP concentrations to guarantee a safe treatment modality to patients. Finally, a few clinical examples of how DAMPs and SAMPs might be used as therapeutic targets or therapeutics in the future are discussed, including inhibition of DAMPs in hyperinflammatory processes (e.g., systemic inflammatory response syndrome, as currently observed in Covid-19), administration of SAMPs in chronic inflammatory diseases, inhibition of SAMPs in hyperresolving processes (e.g., compensatory anti-inflammatory response syndrome), and administration/induction of DAMPs in vaccination procedures and anti-cancer therapy.

Inhibition of human lung adenocarcinoma growth and metastasis by JC polyomavirus-like particles packaged with an SP-B promoter-driven CD59-specific shRNA

Lung cancer ranks first in both incidence and mortality and is a major health concern worldwide. Upon recognition of specific antigens on tumor cells, complement-dependent cytotoxicity (CDC) is activated, arresting cell growth or inducing apoptosis. However, by overexpressing CD59, a membrane complement regulatory protein (mCRP), lung cancer cells develop resistance to CDC. We previously showed that virus-like particles (VLPs) of human JC polyomavirus (JCPyV) could be used as a gene therapy vector to carry a suicide gene expression plasmid with a lung-specific promoter (SP-B (surfactant protein B)) for lung adenocarcinomas. Herein, we designed a CD59-specific short hairpin RNA (shRNA) expression plasmid driven by SP-B (pSPB-shCD59) to effectively and specifically inhibit CD59 overexpression in lung cancer cells. Treatment of lung cancer cells in vitro with JCPyV VLPs containing pSPB-shCD59 (pSPB-shCD59/VLPs) induces CDC and death of cancer cells. Mice that were subcutaneously injected with human lung cancer cells showed an 87% inhibition in tumor growth after tail vein injection of pSPB-shCD59/VLPs. Moreover, in a mouse model of lung cancer metastasis, a reduction in the lung weight by 39%, compared with the control group, was observed in mice treated with pSPB-shCD59/VLPs after tail vein injection of human lung cancer cells. Furthermore, tissue sectioning showed that the number and size of tumors produced was significantly reduced in the lungs of mice in the treatment group than those of the untreated group, indicating inhibition of metastasis by pSPB-shCD59/VLPs. Together, these results demonstrate the potential of pSPB-shCD59/VLPs as a therapeutic agent for CD59 overexpressed lung cancer.

Assessing Oligonucleotide Binding to Double-Stranded DNA

Sequence-specific targeting of double-stranded DNA (dsDNA) using synthetic oligonucleotides (ONs) has been under investigation in different therapeutic approaches. Several methods can be used to evaluate ONs effect and binding capacity to their target sequence. Here we describe some of the methods, which have been frequently used for assessing ONs binding to dsDNA.

Design, Preparation, and Characterization of Peptide-Based Nanocarrier for Gene Delivery

The delivery of nucleic acid to eukaryotic cells is challenging due to presence of various intra- and extracellular barriers and need to delivery carriers. However, current gene delivery carriers, including PLL, PEI, and liposome, suffer from nanocarrier associate toxicity, low efficiency and polydispersity, and non-biodegradability. Here we describe our strategy for developing safe, efficacious, and monodisperse peptide-based carrier for gene delivery. We explain the use of genetic engineering technology for integrating various functional motifs in a single peptide, with less than 100 nm size, which facilitated gene delivery into mammalian cell.

Non-cationic Material Design for Nucleic Acid Delivery

Nucleic acid delivery provides effective options to control intracellular gene expression and protein production. Efficient delivery of nucleic acid typically requires delivery vehicles to facilitate the entry of nucleic acid into cells. Among non-viral delivery vehicles, cationic materials are favored because of their high loading capacity of nucleic acids and prominent cellular uptake efficiency through electrostatic interaction. However, cationic moieties at high dosage tend to induce severe cytotoxicity due to the interference on cell membrane integrity. In contrast, non-cationic materials present alternative delivery approaches with less safety concerns than cationic materials. In this Progress Report, principles of non-cationic material design for nucleic acid delivery are discussed. Examples of such non-cationic platforms are highlighted, including complexation or conjugation with nucleic acids and self-assembled nucleic acid structures.

Contact-Triggered Lipofection from Multilayer Films Designed as Surfaces for in Situ Transfection Strategies in Tissue Engineering

Biomaterials, which release active compounds after implantation, are an essential tool for targeted regenerative medicine. In this study, thin multilayer films loaded with lipid/DNA complexes (lipoplexes) were designed as surface coatings for in situ transfection applicable in tissue engineering and regenerative medicine. The film production and embedding of lipoplexes were based on the layer-by-layer (LbL) deposition technique. Hyaluronic acid (HA) and chitosan (CHI) were used as the polyelectrolyte components. The embedded plasmid DNA was complexed using a new designed cationic lipid formulation, namely, OH4/DOPE 1/1, the advantageous characteristics of which have been proven already. Three different methods were tested regarding its efficiency of lipid and DNA deposition. Therefore, several surface specific analytics were used to characterize the LbL formation, the lipid DNA embedding, and the surface characteristics of the multilayer films, such as fluorescence microscopy, surface plasmon resonance spectroscopy, ellipsometry, zeta potential measurements, atomic force microscopy, and scanning electron microscopy. Interaction studies were conducted for optimized lipoplex-loaded polyelectrolyte multilayers (PEMs) that showed an efficient attachment of C2C12 cells on the surface. Furthermore, no acute toxic effects were found in cell culture studies, demonstrating biocompatibility. Cell culture experiments with C2C12 cells, a cell line which is hard to transfect, demonstrated efficient transfection of the reporter gene encoding for green fluorescent protein. In vivo experiments using the chicken embryo chorion allantois membrane animal replacement model showed efficient gene-transferring rates in living complex tissues, although the DNA-loaded films were stored over 6 days under wet and dried conditions. Based on these findings, it can be concluded that OH4/DOPE 1/1 lipoplex-loaded PEMs composed of HA and CHI can be an efficient tool for in situ transfection in regenerative medicine.

Limb-girdle Muscular Dystrophy and Therapy: Insights into Cell and Gene-based Approaches

The Limb-Girdle Muscular Dystrophies (LGMD) are genetically heterogeneous disorders, responsible for muscle wasting and severe form of dystrophies. Despite the critical developments in the insight and information of pathomechanisms of limb-girdle muscular dystrophy, any definitive treatments do not exist, and current strategies are only based on the improvement of the signs of disorder and to enhance the life quality without resolving an underlying cause. There is a crucial relationship between pharmacological therapy and different consequences; therefore, other treatment strategies will be required. New approaches, such as gene replacement, gene transfer, exon skipping, siRNA knockdown, and anti-myostatin therapy, which can target specific cellular or molecular mechanism of LGMD, could be a promising avenue for the treatment. Recently, genome engineering strategies with a focus on molecular tools such as CRISPR-Cas9 are used to different types of neuromuscular disorders and show the highest potential for clinical translation of these therapies. Thus, recent advancements and challenges in the field will be reviewed in this paper.

Evaluation of therapeutic effect of targeting nanobubbles conjugated with NET-1 siRNA by shear wave elastography: an in vivo study of hepatocellular carcinoma bearing mice model

This study aimed at investigating the tumor stiffness of hepatocellular carcinoma (HCC) bearing mice model in vivo to evaluate the therapeutic efficacy of targeting nanobubbles (TNBS) conjugated with NET-1 siRNA (NET-1 siRNA-TNBS). Also tested whether shear wave elastography (SWE) could demonstrate the pathological tumor changes and used to monitor therapeutic efficacy as a noninvasive method. The HCC bearing mice model was established by injecting human HCC cell line (HepG2). The mice were then divided into three groups randomly, and were treated with TNBS conjugated with NET-1 siRNA, TNBS conjugated with negative control gene, and saline as control. US-SWE was performed for three times. SWE values of all the tumors in three groups were increased with tumor growth. Emax was correlated with tumor size (p < .05). NET-1 gene (treatment group) significantly delayed the growth of tumor size compared to other two groups (p < .0001), showing a significantly increased Emax (p < .05). Immunohistochemical results showed that the NET-1 protein expression was significantly lower than the negative control and blank groups. In conclusion, TNBS conjugated with NET-1 siRNA inhibited tumor growth and prolonged the life of experimental animals. SWE provided a noninvasive and real time imaging method to detect the changes in tumor development.

Intracellular build-up RNAi with single-strand circular RNAs as siRNA precursors

We herein report a new approach for RNA interference, so-called “build-up RNAi” approach, where single-strand circular RNAs with a photocleavable unit or disulfide moiety were used as siRNA precursors.

Editorial focus: understanding off-target effects as the key to successful RNAi therapy

With the first RNA interference (RNAi) drug (ONPATTRO (patisiran)) on the market, we witness the RNAi therapy field reaching a critical turning point, when further improvements in drug candidate design and delivery pipelines should enable fast delivery of novel life changing treatments to patients. Nevertheless, ignoring parallel development of RNAi dedicated in vitro pharmacological profiling aiming to identify undesirable off-target activity may slow down or halt progress in the RNAi field. Since academic research is currently fueling the RNAi development pipeline with new therapeutic options, the objective of this article is to briefly summarize the basics of RNAi therapy, as well as to discuss how to translate basic research into better understanding of related drug candidate safety profiles early in the process.