Viral Vectors for Gene Therapy: Translational and Clinical Outlook

Gene therapy breakthroughs in ALS: a beacon of hope for 20% of ALS patients

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease that remains incurable. Although the etiologies of ALS are diverse and the precise pathogenic mechanisms are not fully understood, approximately 20% of ALS cases are caused by genetic factors. Therefore, advancing targeted gene therapies holds significant promise, at least for the 20% of ALS patients with genetic etiologies. In this review, we summarize the main strategies and techniques of current ALS gene therapies based on ALS risk genes, and review recent findings from animal studies and clinical trials. Additionally, we highlight ALS-related genes with well-understood pathogenic mechanisms and the potential of numerous emerging gene-targeted therapeutic approaches for ALS.

CRISPR-Cas9 Targeting PCSK9: A Promising Therapeutic Approach for Atherosclerosis

CRISPR-Cas9 gene editing technology, as an innovative biomedical tool, holds significant potential in the prevention and treatment of atherosclerosis. By precisely editing key genes such as PCSK9, CRISPR-Cas9 offers the possibility of long-term regulation of low-density lipoprotein cholesterol (LDL-C), which may reduce the risk of cardiovascular diseases. Early clinical studies of gene editing therapies like VERVE-101 have yielded encouraging results, highlighting both the feasibility and potential efficacy of this technology. However, clinical applications still face challenges such as off-target effects, immunogenicity, and long-term safety. Future research should focus on enhancing the specificity and efficiency of gene editing, optimizing delivery systems, and improving personalized treatment strategies. Additionally, the establishment of ethical and legal regulatory frameworks will be critical for the safe adoption of this technology. With the continued advancement of gene editing technology, CRISPR-Cas9 may become an important tool for treating atherosclerosis and other complex diseases.

Evaluation of Purification Methods for Minimizing Transgene Expression Background During Viral Manufacturing

Gene therapy has emerged as a promising therapeutic avenue, offering targeted treatments for various diseases. Purification of viral vectors presents a pivotal challenge, demanding the removal of impurities while preserving integrity and potency. During manufacturing, producer cells in transfection systems can be transiently transfected or retro-infected by the viral vectors they have just produced-a process referred to as "retro-transduction"-leading them to express the transgenes of interest. This can be a significant source of contamination in the viral solution pool, particularly when the transgenes encode extracellular, secreted proteins, resulting in cytotoxicity and reduced viral potency. Herein, we aimed to evaluate the efficiency of different viral purification systems commonly used in academic and industry settings in removing the transgene background from viral solutions. The efficiency of each system was assessed based on the levels of the secreted transgene Gaussia Luciferase (GLuc), which can be quickly detected in a solution and served as a readout for transgene background contamination in the viral pool during downstream processing. Through a systematic evaluation of purification methods, we identified the most effective approaches for producing pure viral batches with minimal transgene background, all while preserving viral potency and functionality. Our study revealed superior performance of batches that underwent purification via tangential flow filtration, which yielded over 90% reduction in GLuc background and the highest transduction efficiency rates. This work provides significant insights for advancing gene therapy applications that rely on the production of viral vectors encoding secreted transgenes.

Lactate and lactylation in cancer

Accumulated evidence has implicated the diverse and substantial influence of lactate on cellular differentiation and fate regulation in physiological and pathological settings, particularly in intricate conditions such as cancer. Specifically, lactate has been demonstrated to be pivotal in molding the tumor microenvironment (TME) through its effects on different cell populations. Within tumor cells, lactate impacts cell signaling pathways, augments the lactate shuttle process, boosts resistance to oxidative stress, and contributes to lactylation. In various cellular populations, the interplay between lactate and immune cells governs processes such as cell differentiation, immune response, immune surveillance, and treatment effectiveness. Furthermore, communication between lactate and stromal/endothelial cells supports basal membrane (BM) remodeling, epithelial-mesenchymal transitions (EMT), metabolic reprogramming, angiogenesis, and drug resistance. Focusing on lactate production and transport, specifically through lactate dehydrogenase (LDH) and monocarboxylate transporters (MCT), has shown promise in the treatment of cancer. Inhibitors targeting LDH and MCT act as both tumor suppressors and enhancers of immunotherapy, leading to a synergistic therapeutic effect when combined with immunotherapy. The review underscores the importance of lactate in tumor progression and provides valuable perspectives on potential therapeutic approaches that target the vulnerability of lactate metabolism, highlighting the Heel of Achilles for cancer treatment.

Nature Inspired Delivery Vehicles for CRISPR-Based Genome Editing

The advent of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based genome editing technologies has opened up groundbreaking possibilities for treating a wide spectrum of genetic disorders and diseases. However, the success of these technologies relies heavily on the development of efficient and safe delivery systems. Among the most promising approaches are natural and synthetic nanocarrier-mediated delivery systems, including viral vectors, extracellular vesicles (EVs), engineered cellular membrane particles, liposomes, and various nanoparticles. These carriers enhance the efficacy of the CRISPR system by providing a unique combination of efficiency, specificity, and reduced immunogenicity. Synthetic carriers such as liposomes and nanoparticles facilitate CRISPR delivery with high reproducibility and customizable functions. Viral vectors, renowned for their high transduction efficiency and broad tropism, serve as powerful vehicles for delivering CRISPR components to various cell types. EVs, as natural carriers of RNA and proteins, offer a stealth mechanism to evade immune detection, allowing for the targeted delivery of genome editors with minimal off-target effects. Engineered cellular membrane particles further improve delivery by simulating the cellular environment, enhancing uptake, and minimizing immune response. This review explores the innovative integration of CRISPR genome editors with various nanocarrier systems, focusing on recent advancements, applications, and future directions in therapeutic genome editing.

Genetically modified organoids for tissue engineering and regenerative medicine

To date, genetically modified organoids are emerging as a promising 3D modeling tool aimed at solving genetically relevant clinical and biomedical problems for regenerative medicine and tissue engineering. As an optimal vehicle for gene delivery, genetically modified organoids can enhance or reduce the expression of target genes through virus and non-virus-based gene transfection methods to achieve tissue regeneration. Animal experiments and preclinical studies have demonstrated the beneficial role of genetically modified organoids in various aspects of organ regeneration, including thymus, lacrimal glands, brain, lung, kidney, photoreceptors, etc. Furthermore, the technology offers a potential treatment option for various diseases, such as Fabry disease, non-alcoholic steatohepatitis, and Lynch syndrome. Nevertheless, the uncertain safety of genetic modification, the risk of organoid application, and bionics of current genetically modified organoids are still challenging. This review summarizes the researches on genetically modified organoids in recent years, and describes the transfection methods and functions of genetically modified organoids, then introduced their applications at length. Also, the limitations and future development directions of genetically modified organoids are included.

PDGFR-α shRNA-polyplex for uveal melanoma treatment via EMT mediated vasculogenic mimicry interfering

Up to 50% of individuals with uveal melanoma (UM), a frequent cancer of the eye, pass away from metastases. One of the major challenges in treating UM is the role of receptor tyrosine kinases (RTKs), which mediate the epithelial-mesenchymal transition (EMT) of tumors. RTKs are involved in binding multiple growth factors, leading to angiogenesis and vasculogenic mimicry (VM) phenomena. Currently, most anti-angiogenic drugs have shown a tendency to increase the VM of tumors in clinical trials, resulting in limited efficacy. The existing gap in UM treatment lies in the lack of effective strategies to target RTK-mediated EMT and VM. While some approaches have been attempted, there is still a need for novel therapeutic interventions that can specifically interfere with these processes. This research employed the gene vector PEI-g-PEG to interfere with the platelet derived growth factor-alpha receptor (PDGFR-α)-mediated EMT process, thereby retarding the growth of UM. The cell experiments demonstrated that the gene polyplex exhibited favorable cell uptake and lysosome escape properties, effectively suppressing the expression of PDGFR-α protein and EMT marker proteins and the occurrence of VM phenomenon. In vivo animal studies also inhibited the growth of UM, and PAS assays showed that the treatment reduced the generation of VM in tumor tissue. This study broadens the application of PEI-g-PEG while interfering with the RTK-mediated tumor EMT process with the help of RNAi technology, providing a new idea for tumor reduction research.

Sonogenetics in the Treatment of Chronic Diseases: A New Method for Cell Regulation

Sonogenetics is an innovative technology that integrates ultrasound with genetic editing to precisely modulate cellular activities in a non-invasive manner. This method entails introducing and activating mechanosensitive channels on the cell membrane of specific cells using gene delivery vectors. When exposed to ultrasound, these channels can be manipulated to open or close, thereby impacting cellular functions. Sonogenetics is currently being used extensively in the treatment of various chronic diseases, including Parkinson's disease, vision restoration, and cancer therapy. This paper provides a comprehensive review of key components of sonogenetics and focuses on evaluating its prospects and potential challenges in the treatment of chronic disease.

Tumor cell membrane-based vaccines: A potential boost for cancer immunotherapy

Because therapeutic cancer vaccines can, in theory, eliminate tumor cells specifically with relatively low toxicity, they have long been considered for application in repressing cancer progression. Traditional cancer vaccines containing a single or a few discrete tumor epitopes have failed in the clinic, possibly due to challenges in epitope selection, target downregulation, cancer cell heterogeneity, tumor microenvironment immunosuppression, or a lack of vaccine immunogenicity. Whole cancer cell or cancer membrane vaccines, which provide a rich source of antigens, are emerging as viable alternatives. Autologous and allogenic cellular cancer vaccines have been evaluated as clinical treatments. Tumor cell membranes (TCMs) are an intriguing antigen source, as they provide membrane-accessible targets and, at the same time, serve as integrated carriers of vaccine adjuvants and other therapeutic agents. This review provides a summary of the properties and technologies for TCM cancer vaccines. Characteristics, categories, mechanisms, and preparation methods are discussed, as are the demonstrable additional benefits derived from combining TCM vaccines with chemotherapy, sonodynamic therapy, phototherapy, and oncolytic viruses. Further research in chemistry, biomedicine, cancer immunology, and bioinformatics to address current drawbacks could facilitate the clinical adoption of TCM vaccines.

A new target for treating intervertebral disk degeneration: gut microbes

Intervertebral disk degeneration (IDD) is a common clinical spinal disease and one of the main causes of low back pain (LBP). Generally speaking, IDD is considered a natural degenerative process with age. However, with the deepening of research, people have discovered that IDD is not only related to age, but also has many factors that can induce and accelerate its progression. In addition, the pathogenesis of IDD remains unclear, resulting in limited traditional treatment methods that cannot effectively prevent and treat IDD. Conservative treatment may lead to patients' dependence on drugs, and the pain relief effect is not obvious. Similarly, surgical treatment is highly invasive, with a longer recovery time and a higher recurrence rate. With the deepening of exploration, people have discovered that intestinal microorganisms are an important symbiotic microbial community in the human body and are closely related to the occurrence and development of various diseases. Changes in intestinal microorganisms and their metabolites may affect the body's inflammatory response, immune regulation, and metabolic processes, thereby affecting the health of the intervertebral disk. In this context, the gut microbiota has received considerable attention as a potential target for delaying or treating IDD. This article first introduces the impact of gut microbes on common distal organs, and then focuses on three potential mechanisms by which gut microbes and their metabolites influence IDD. Finally, we also summarized the methods of delaying or treating IDD by interfering with intestinal microorganisms and their metabolites. Further understanding of the potential mechanisms between intestinal microorganisms and IDD will help to formulate reasonable IDD treatment strategies to achieve ideal therapeutic effects.

Therapeutic Applications of Engineered Mesenchymal Stromal Cells for Enhanced Angiogenesis in Cardiac and Cerebral Ischemia

Ischemic diseases are characterized by obstruction of blood flow to the respective organs, of which ischemia of the heart and brain are the most prominent manifestations with shared pathophysiological mechanisms and risk factors. While most revascularization therapies aim to restore blood flow, this can be challenging due to the limited therapeutic window available for treatment approaches. For a very long time, mesenchymal stromal cells have been used to treat cerebral and cardiac ischemia. However, their application is restricted either by inefficient mode of delivery or the low cell survival rates following implantation into the ischemic microenvironment. Nonetheless, several studies are currently focusing on using of mesenchymal stromal cells engineered to overexpress therapeutic genes as a cell-based gene therapy to restore angiogenesis. This review delves into the utilization of MSCs for angiogenesis and the applications of engineered MSCs for the treatment of cardiac and cerebral ischemia. Moreover, the safety issues related to the genetic modification of MSCs have also been discussed.

Unlocking Genome Editing: Advances and Obstacles in CRISPR/Cas Delivery Technologies

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats associated with protein 9) was first identified as a component of the bacterial adaptive immune system and subsequently engineered into a genome-editing tool. The key breakthrough in this field came with the realization that CRISPR/Cas9 could be used in mammalian cells to enable transformative genetic editing. This technology has since become a vital tool for various genetic manipulations, including gene knockouts, knock-in point mutations, and gene regulation at both transcriptional and post-transcriptional levels. CRISPR/Cas9 holds great potential in human medicine, particularly for curing genetic disorders. However, despite significant innovation and advancement in genome editing, the technology still possesses critical limitations, such as off-target effects, immunogenicity issues, ethical considerations, regulatory hurdles, and the need for efficient delivery methods. To overcome these obstacles, efforts have focused on creating more accurate and reliable Cas9 nucleases and exploring innovative delivery methods. Recently, functional biomaterials and synthetic carriers have shown great potential as effective delivery vehicles for CRISPR/Cas9 components. In this review, we attempt to provide a comprehensive survey of the existing CRISPR-Cas9 delivery strategies, including viral delivery, biomaterials-based delivery, synthetic carriers, and physical delivery techniques. We underscore the urgent need for effective delivery systems to fully unlock the power of CRISPR/Cas9 technology and realize a seamless transition from benchtop research to clinical applications.

Development and applications of lipid hydrophilic headgroups for nucleic acid therapy

Nucleic acid therapy is currently the most promising method for treating tumors and genetic diseases and for preventing infectious diseases. However, the biggest obstacle to this therapy is delivery of the nucleic acids to the target site, which requires overcoming problems such as capture by the immune system, the need to penetrate biofilms, and degradation of nucleic acid performance. Designing suitable delivery vectors is key to solving these problems. Lipids-which consist of a hydrophilic headgroup, a linker, and a hydrophobic tail-are crucial components for the construction of vectors. The headgroup is particularly important because it affects the drug encapsulation rate, the vector cytotoxicity, and the transfection efficiency. Herein, we focus on various headgroup structures (tertiary amines, quaternary ammonium salts, peptides, piperazines, dendrimers, and several others), and we summarize and classify important lipid-based carriers that have been developed in recent years. We also discuss applications of cationic lipids with various headgroups for delivery of nucleic acid drugs, and we analyze how headgroup structure affects transport efficiency and carrier toxicity. Finally, we briefly describe the challenges of developing novel lipid carriers, as well as their prospects.

CRISPR/Cas9-mediated neuronal deletion of 5-lipoxygenase alleviates deficits in mouse models of epilepsy

INTRODUCTION

Our previous work reveals a critical role of activation of neuronal Alox5 in exacerbating brain injury post seizures. However, whether neuronal Alox5 impacts the pathological process of epilepsy remains unknown.

OBJECTIVES

To prove the feasibility of neuron-specific deletion of Alox5 via CRISPR-Cas9 in the blockade of seizure onset and epileptic progression.

METHODS

Here, we employed a Clustered regularly interspaced short-palindromic repeat-associated proteins 9 system (CRISPR/Cas9) system delivered by adeno-associated virus (AAV) to specifically delete neuronal Alox5 gene in the hippocampus to explore its therapeutic potential in various epilepsy mouse models and possible mechanisms.

RESULTS

Neuronal depletion of Alox5 was successfully achieved in the brain. AAV delivery of single guide RNA of Alox5 in hippocampus resulted in reducing seizure severity, delaying epileptic progression and improving epilepsy-associated neuropsychiatric comorbidities especially anxiety, cognitive deficit and autistic-like behaviors in pilocarpine- and kainic acid-induced temporal lobe epilepsy (TLE) models. In addition, neuronal Alox5 deletion also reversed neuron loss, neurodegeneration, astrogliosis and mossy fiber sprouting in TLE model. Moreover, a battery of tests including analysis of routine blood test, hepatic function, renal function, routine urine test and inflammatory factors demonstrated no noticeable toxic effect, suggesting that Alox5 deletion possesses the satisfactory biosafety. Mechanistically, the anti-epileptic effect of Alox5 deletion might be associated with reduction of glutamate level to restore excitatory/inhibitory balance by reducing CAMKII-mediated phosphorylation of Syn ISer603.

CONCLUSION

Our findings showed the translational potential of AAV-mediated delivery of CRISPR-Cas9 system including neuronal Alox5 gene for an alternative promising therapeutic approach to treat epilepsy.

Beyond Lipids: Exploring Advances in Polymeric Gene Delivery in the Lipid Nanoparticles Era

The recent success of gene therapy during the COVID-19 pandemic has underscored the importance of effective and safe delivery systems. Complementing lipid-based delivery systems, polymers present a promising alternative for gene delivery. Significant advances have been made in the recent past, with multiple clinical trials progressing beyond phase I and several companies actively working on polymeric delivery systems which provides assurance that polymeric carriers can soon achieve clinical translation. The massive advantage of structural tunability and vast chemical space of polymers is being actively leveraged to mitigate shortcomings of traditional polycationic polymers and improve the translatability of delivery systems. Tailored polymeric approaches for diverse nucleic acids and for specific subcellular targets are now being designed to improve therapeutic efficacy. This review describes the recent advances in polymer design for improved gene delivery by polyplexes and covalent polymer-nucleic acid conjugates. The review also offers a brief note on novel computational techniques for improved polymer design. The review concludes with an overview of the current state of polymeric gene therapies in the clinic as well as future directions on their translation to the clinic.

Adeno-Associated Virus Engineering and Load Strategy for Tropism Modification, Immune Evasion and Enhanced Transgene Expression

Gene therapy aims to add, replace or turn off genes to help treat disease. To date, the US Food and Drug Administration (FDA) has approved 14 gene therapy products. With the increasing interest in gene therapy, feasible gene delivery vectors are necessary for inserting new genes into cells. There are different kinds of gene delivery vectors including viral vectors like lentivirus, adenovirus, retrovirus, adeno-associated virus et al, and non-viral vectors like naked DNA, lipid vectors, polymer nanoparticles, exosomes et al, with viruses being the most commonly used. Among them, the most concerned vector is adeno-associated virus (AAV) because of its safety, natural ability to efficiently deliver gene into cells and sustained transgene expression in multiple tissues. In addition, the AAV genome can be engineered to generate recombinant AAV (rAAV) containing transgene sequences of interest and has been proven to be a safe gene vector. Recently, rAAV vectors have been approved for the treatment of various rare diseases. Despite these approvals, some major limitations of rAAV remain, namely nonspecific tissue targeting and host immune response. Additional problems include neutralizing antibodies that block transgene delivery, a finite transgene packaging capacity, high viral titer used for per dose and high cost. To deal with these challenges, several techniques have been developed. Based on differences in engineering methods, this review proposes three strategies: gene engineering-based capsid modification (capsid modification), capsid surface tethering through chemical conjugation (surface tethering), and other formulations loaded with AAV (virus load). In addition, the major advantages and limitations encountered in rAAV engineering strategies are summarized.

Aerosol Inhalation of Gene Delivery Therapy for Pulmonary Diseases

Gene delivery therapy has emerged as a popular approach for the treatment of various diseases. However, it still poses the challenges of accumulation in target sites and reducing off-target effects. Aerosol gene delivery for the treatment of pulmonary diseases has the advantages of high lung accumulation, specific targeting and fewer systemic side effects. However, the key challenge is selecting the appropriate formulation for aerosol gene delivery that can overcome physiological barriers. There are numerous existing gene carriers under study, including viral vectors and non-viral vectors. With the development of biomaterials, more biocompatible substances have applied gene delivery via inhalation. Furthermore, many types of genes can be delivered through aerosol inhalation, such as DNA, mRNA, siRNA and CRISPR/Cas9. Aerosol delivery of different types of genes has proven to be efficient in the treatment of many diseases such as SARS-CoV-2, cystic fibrosis and lung cancer. In this paper, we provide a comprehensive review of the ongoing research on aerosol gene delivery therapy, including the basic respiratory system, different types of gene carriers, different types of carried genes and clinical applications.

Engineered exosomes: a potential therapeutic strategy for septic cardiomyopathy

Septic cardiomyopathy, a life-threatening complication of sepsis, can cause acute heart failure and carry a high mortality risk. Current treatments have limitations. Fortunately, engineered exosomes, created through bioengineering technology, may represent a potential new treatment method. These exosomes can both diagnose and treat septic cardiomyopathy, playing a crucial role in its development and progression. This article examines the strategies for using engineered exosomes to protect cardiac function and treat septic cardiomyopathy. It covers three innovative aspects: exosome surface modification technology, the use of exosomes as a multifunctional drug delivery platform, and plant exosome-like nanoparticle carriers. The article highlights the ability of exosomes to deliver small molecules, proteins, and drugs, summarizing several RNA molecules, proteins, and drugs beneficial for treating septic cardiomyopathy. Although engineered exosomes are a promising biotherapeutic carrier, they face challenges in clinical application, such as understanding the interaction mechanism with host cells, distribution within the body, metabolism, and long-term safety. Further research is essential, but engineered exosomes hold promise as an effective treatment for septic cardiomyopathy.

Peptide-based non-viral gene delivery: A comprehensive review of the advances and challenges

Gene therapy is the most effective treatment option for diseases, but its effectiveness is affected by the choice and design of gene carriers. The genes themselves have to pass through multiple barriers in order to enter the cell and therefore require additional vectors to carry them inside the cell. In gene therapy, peptides have unique properties and potential as gene carriers, which can effectively deliver genes into specific cells or tissues, protect genes from degradation, improve gene transfection efficiency, and enhance gene targeting and biological responsiveness. This paper reviews the research progress of peptides and their derivatives in the field of gene delivery recently, describes the obstacles encountered by foreign materials to enter the interior of the cell, and introduces the following classes of functional peptides that can carry materials into the interior of the cell, and assist in transmembrane translocation of carriers, thus breaking through endosomal traps to enable successful entry of genetic materials into the nucleus of the cell. The paper also discusses the combined application of peptide vectors with other vectors to enhance its transfection ability, explores current challenges encountered by peptide vectors, and looks forward to future developments in the field.

Studying the ssDNA loaded adeno-associated virus aggregation using coarse-grained molecular dynamics simulations

The aggregation of adeno-associated viral (AAV) capsids in an aqueous environment was investigated via coarse-grained molecular dynamics (CG-MD) simulations. The primary driving force and mechanism of the aggregation were investigated with or without single-strand DNA (ssDNA) loaded at various process temperatures. Capsid aggregation appeared to involve multiple residue interactions (i.e., hydrophobic, polar and charged residues) leading to complex protein aggregation. In addition, two aggregation mechanisms (i.e., the fivefold face-to-face contact and the edge-to-edge contact) were identified from this study. The ssDNA with its asymmetric structure could be the reason for destabilizing protein subunits and enhancing the interaction between the charged residues, and further result in the non-reversible face-to-face contact. At higher temperature, the capsid structure was found to be unstable with the significant size expansion of the loaded ssDNA which could be attributed to reduced number of intramolecular hydrogen bonds, the increased conformational deviations of protein subunits and the higher residue fluctuations. The CG-MD model was further validated with previous experimental and simulation data, including the full capsid size measurement and the capsid internal pressure. Thus, a good understanding of AAV capsid aggregation, instability and the role of ssDNA were revealed by applying the developed computational model.

The evolving landscape of gene therapy strategies for the treatment of osteoarthritis

OBJECTIVES

Significant advances have been made in our understanding of osteoarthritis (OA) pathogenesis; however, no disease-modifying therapies have been identified. This review will summarize the gene therapy landscape, its initial successes for OA, and possible challenges using recent studies and examples of gene therapies in clinical trials.

DESIGN

This narrative review has three major sections: 1) vector systems for OA gene therapy, 2) current and emerging targets for OA gene therapy, and 3) considerations and future directions.

RESULTS

Gene therapy is the strategy by which nucleic acids are delivered to treat and reverse disease progression. Specificity and prolonged expression of these nucleic acids are achieved by manipulating promoters, genes, and vector systems. Certain vector systems also allow for the development of combinatorial nucleic acid strategies that can be delivered in a single intraarticular injection - an approach likely required to treat the complexity of OA pathogenesis. Several viral and non-viral vector-based gene therapies are in clinical trials for OA, and many more are being evaluated in the preclinical arena.

CONCLUSIONS

In a post-coronavirus disease 2019 (COVID-19) era, the future of gene therapy for OA is certainly promising; however, the majority of preclinical validation continues to focus heavily on post-traumatic models and changes in only cartilage and subchondral bone. To ensure successful translation, new candidates in the preclinical arena should be examined against all joint tissues as well as pain using diverse models of injury-, obesity-, and age-induced disease. Lastly, consideration must be given to strategies for repeat administration and the cost of treatment owing to the chronic nature of OA.

Adeno-associated virus analysis by size exclusion chromatography within 3 minutes using short bio-inert columns made with 3 µm particles operated at high flowrates

Adeno-associated virus (AAV) analytical characterization is crucial to the well-defined and reproducible production of human gene therapies utilizing the AAV vector modality. The establishment of analytical methods based upon technology platforms currently widely used by bio-therapeutic manufacturers, namely HPLC, will assist efforts to produce high quality AAV reproducibly and decrease chemical manufacturing and control challenges in method portability and reliability. AAV analysis by size exclusion chromatography (SEC) is currently practiced with columns and mobile phase conditions traditional to SEC of proteins. Here, an improved method to measure multiple AVV critical quality attributes (CQA) rapidly by SEC is explored. The use of short columns made with small particles at high flow rates resulted in up to 80 % reduction in analysis time and 66 % in sample consumption while maintaining reliable quantitation of AAV aggregate or high molecular weight (HMW) content. These results were demonstrated across four different AAV serotypes. Furthermore, critical AAV sample handling learnings are shared.

Emerging Gene Therapeutics for Epidermolysis Bullosa under Development

The monogenetic disease epidermolysis bullosa (EB) is characterised by the formation of extended blisters and lesions on the patient's skin upon minimal mechanical stress. Causal for this severe condition are genetic mutations in genes, leading to the functional impairment, reduction, or absence of the encoded protein within the skin's basement membrane zone connecting the epidermis to the underlying dermis. The major burden of affected families justifies the development of long-lasting and curative therapies operating at the genomic level. The landscape of causal therapies for EB is steadily expanding due to recent breakthroughs in the gene therapy field, providing promising outcomes for patients suffering from this severe disease. Currently, two gene therapeutic approaches show promise for EB. The clinically more advanced gene replacement strategy was successfully applied in severe EB forms, leading to a ground-breaking in vivo gene therapy product named beremagene geperpavec (B-VEC) recently approved from the US Food and Drug Administration (FDA). In addition, the continuous innovations in both designer nucleases and gene editing technologies enable the efficient and potentially safe repair of mutations in EB in a potentially permanent manner, inspiring researchers in the field to define and reach new milestones in the therapy of EB.

Tailoring cell sheets for biomedical applications

Cell sheet technology has emerged as a novel scaffold-free approach for cell-based therapies in regenerative medicine. Techniques for harvesting cell sheets are essential to preserve the integrity of living cell sheets. This review provides an overview of fundamental technologies to fabricate cell sheets and recent advances in cell sheet-based tissue engineering. In addition to the commonly used temperature-responsive systems, we introduce alternative approaches, such as ROS-induced, magnetic-controlled, and light-induced cell sheet technologies. Moreover, we discuss the modification of the cell sheet to improve its function, including stacking, genetic modification, and vascularization. With the significant advances in cell sheet technology, cell sheets have been widely applied in various tissues and organs, including but not limited to the lung, cornea, cartilage, periodontium, heart, and liver. This review further describes both the preclinical and clinical applications of cell sheets. We believe that the progress in cell sheet technology would further propel its biomedical applications.

CRISPR-Cas9 technology: As an efficient genome modification tool in the cancer diagnosis and treatment

Cancer is the second most common cause of death globally and is a major public health concern. Managing this disease is difficult due to its multiple stages and numerous genetic and epigenetic changes. Traditional cancer diagnosis and treatment methods have limitations, making it crucial to develop new modalities to combat the increasing burden of cancer. The clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has transformed genetic engineering due to its simplicity, specificity, low cytotoxicity, and cost-effectiveness. It has been proposed as an effective technology to enhance cancer diagnosis and treatment strategies. This article presents the most recent discoveries regarding the structure, mechanism, and delivery methods of the highly powerful genome editing tool, CRISPR-Cas9. In terms of diagnosis, the article examines the role of CRISPR-Cas9 in detecting microRNAs and DNA methylation, and discusses two popular gene detection techniques that utilize the CRISPR-Cas system: DNA endonuclease-targeted CRISPR trans reporter and specific high sensitivity enzymatic reporter unlocking. Regarding treatment, the article explores several genes that have been identified and modified by CRISPR-Cas9 for effective tumorigenesis of common cancers such as breast, lung, and colorectal cancer. The present review also addresses the challenges and ethical issues associated with using CRISPR-Cas9 as a diagnostic and therapeutic tool. Despite some limitations, CRISPR-Cas9-based cancer diagnosis has the potential to become the next generation of cancer diagnostic tools, and the continuous progress of CRISPR-Cas9 can greatly aid in cancer treatment.

CRISPR/Cas gene editing and delivery systems for cancer therapy

CRISPR/Cas systems stand out because of simplicity, efficiency, and other superiorities, thus becoming attractive and brilliant gene-editing tools in biomedical field including cancer therapy. CRISPR/Cas systems bring promises for cancer therapy through manipulating and engineering on tumor cells or immune cells. However, there have been concerns about how to overcome the numerous physiological barriers and deliver CRISPR components to target cells efficiently and accurately. In this review, we introduced the mechanisms of CRISPR/Cas systems, summarized the current delivery strategies of CRISPR/Cas systems by physical methods, viral vectors, and nonviral vectors, and presented the current application of CRISPR/Cas systems in cancer clinical treatment. Furthermore, we discussed prospects related to delivery approaches of CRISPR/Cas systems. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Advances in Genetic Reprogramming: Prospects from Developmental Biology to Regenerative Medicine

The foundations of cell reprogramming were laid by Yamanaka and co-workers, who showed that somatic cells can be reprogrammed into pluripotent cells (induced pluripotency). Since this discovery, the field of regenerative medicine has seen advancements. For example, because they can differentiate into multiple cell types, pluripotent stem cells are considered vital components in regenerative medicine aimed at the functional restoration of damaged tissue. Despite years of research, both replacement and restoration of failed organs/ tissues have remained elusive scientific feats. However, with the inception of cell engineering and nuclear reprogramming, useful solutions have been identified to counter the need for compatible and sustainable organs. By combining the science underlying genetic engineering and nuclear reprogramming with regenerative medicine, scientists have engineered cells to make gene and stem cell therapies applicable and effective. These approaches have enabled the targeting of various pathways to reprogramme cells, i.e., make them behave in beneficial ways in a patient-specific manner. Technological advancements have clearly supported the concept and realization of regenerative medicine. Genetic engineering is used for tissue engineering and nuclear reprogramming and has led to advances in regenerative medicine. Targeted therapies and replacement of traumatized , damaged, or aged organs can be realized through genetic engineering. Furthermore, the success of these therapies has been validated through thousands of clinical trials. Scientists are currently evaluating induced tissue-specific stem cells (iTSCs), which may lead to tumour-free applications of pluripotency induction. In this review, we present state-of-the-art genetic engineering that has been used in regenerative medicine. We also focus on ways that genetic engineering and nuclear reprogramming have transformed regenerative medicine and have become unique therapeutic niches.

Chimeric antigen receptor Treg therapy in transplantation

In the quest for more precise and effective organ transplantation therapies, chimeric antigen receptor (CAR) regulatory T cell (Treg) therapies represent a potential cutting-edge advance. This review comprehensively analyses CAR Tregs and how they may address important drawbacks of polyclonal Tregs and conventional immunosuppressants. We examine a growing body of preclinical findings of CAR Treg therapy in transplantation, discuss CAR Treg design specifics, and explore established and attractive new targets in transplantation. In addition, we explore present impediments where future studies will be necessary to determine the efficacy of CAR Tregs in reshaping alloimmune responses and transplant microenvironments to reduce reliance on chemical immunosuppressants. Overall, ongoing studies and trials are crucial for understanding the full scope of CAR Treg therapy in transplantation.

Lentiviral-Mediated Systemic RNA Interference In Vivo

The shRNA-encoding lentivirus has been widely used for gene manipulation in preclinical studies. It is a powerful tool for gene transfer and shows promise in its ability to efficiently transduce immune cells and hematopoietic stems cells, which are the initial therapeutic target of autoimmune diseases, and considering that gene manipulation of these cells is usually difficult to achieve using other techniques. In previous chapters, we have described how to produce concentrated shRNA-encoding lentiviral particles. Here, systemic in vivo application of lentivirus, including viral quantification prior to injection, intraperitoneal injection, and quantification of integrated provirus, is introduced.

AAV for Gene Therapy in Ocular Diseases: Progress and Prospects

Owing to the promising therapeutic effect and one-time treatment advantage, gene therapy may completely change the management of eye diseases, especially retinal diseases. Adeno-associated virus (AAV) is considered one of the most promising viral gene delivery tools because it can infect various types of tissues and is considered as a relatively safe gene delivery vector. The eye is one of the most popular organs for gene therapy, since its limited volume is suitable for small doses of AAV stably transduction. Recently, an increasing number of clinical trials of AAV-mediated gene therapy are underway. This review summarizes the biological functions of AAV and its application in the treatment of various ocular diseases, as well as the characteristics of different AAV delivery routes in clinical applications. Here, the latest research progresses in AAV-mediated gene editing and silencing strategies to modify that the genetic ocular diseases are systematically outlined, especially by base editing and prime editing. We discuss the progress of AAV in ocular optogenetic therapy. We also summarize the application of AAV-mediated gene therapy in animal models and the difficulties in its clinical transformation.

Poor Result Reporting Rate in Cell Therapy Trials Registered at ClinicalTrials.gov

As research associates in clinical experiments, we have an obligation to disclose clinical methodologies and findings in full transparency in ethics. However, inadequate disclosure in results reporting clinical trials registered on ClinicalTrials.gov has been revealed, with approximately half the trial results not being reported in an applicable manner. Our recent study in clinical trials of regenerative medicine for four kinds of neurological diseases revealed that the rate of result reporting to ClinicalTrials.gov is inadequate for gene and cell therapy (CT) trials. In this path, further curiosity emerged to see what the findings would be if the analysis was conducted for trials in all disease areas, and outcomes if gene therapy (GT) and CT were distinguished in terms. In this study, the scope of analysis was further expanded to include all disease areas, and the drug classification from the AdisInsight database was used for modality classification, with biologic drug trials classified as controls, CT, ex vivo GT, and in vivo GT. To begin, among all interventional clinical trials with registration in the ClinicalTrials.gov registry and with a primary completion between 2010 and 2019, we created a total of 5539 datasets corresponding to trials classified as GT and CT, while biologics (BLG) as controls in the AdisInsight drug classification. The status of reported results of these trials was identified by surveying posting status of ClinicalTrials.gov and publication in journals (PubMed), respectively. Based on the obtained dataset, multivariate analysis was performed on the data on the reporting rate of clinical trial results, aggregated by sponsor, phase, status, and modality (CT, ex vivo GT, in vivo GT, and BLG), respectively. The result shows that CT was identified as an independent factor restraining result reporting ratio in both ClinicalTrials.gov and total disclosures, whereas ex vivo GT as boosting result reporting ratio. Since the result reporting rate of CT results was notably poor, we discussed the causes and solutions in this regard.

Advances in CAR-Engineered Immune Cell Generation: Engineering Approaches and Sourcing Strategies

Chimeric antigen receptor T-cell (CAR-T) therapy has emerged as a highly efficacious treatment modality for refractory and relapsed hematopoietic malignancies in recent years. Furthermore, CAR technologies for cancer immunotherapy have expanded from CAR-T to CAR-natural killer cell (CAR-NK), CAR-cytokine-induced killer cell (CAR-CIK), and CAR-macrophage (CAR-MΦ) therapy. Nevertheless, the high cost and complex manufacturing processes of ex vivo generation of autologous CAR products have hampered broader application. There is an urgent need to develop an efficient and economical paradigm shift for exploring new sourcing strategies and engineering approaches toward generating CAR-engineered immune cells to benefit cancer patients. Currently, researchers are actively investigating various strategies to optimize the preparation and sourcing of these potent immunotherapeutic agents. In this work, the latest research progress is summarized. Perspectives on the future of CAR-engineered immune cell manufacturing are provided, and the engineering approaches, and diverse sources used for their development are focused upon.

Dually Modified Cellulose as a Non-Viral Vector for the Delivery and Uptake of HDAC3 siRNA

RNA interference can be applied to different target genes for treating a variety of diseases, but an appropriate delivery system is necessary to ensure the transport of intact siRNAs to the site of action. In this study, cellulose was dually modified to create a non-viral vector for HDAC3 short interfering RNA (siRNA) transfer into cells. A guanidinium group introduced positive charges into the cellulose to allow complexation of negatively charged genetic material. Furthermore, a biotin group fixed by a polyethylene glycol (PEG) spacer was attached to the polymer to allow, if required, the binding of targeting ligands. The resulting polyplexes with HDAC3 siRNA had a size below 200 nm and a positive zeta potential of up to 15 mV. For N/P ratio 2 and higher, the polymer could efficiently complex siRNA. Nanoparticles, based on this dually modified derivative, revealed a low cytotoxicity. Only minor effects on the endothelial barrier integrity and a transfection efficiency in HEK293 cells higher than Lipofectamine 2000TM were found. The uptake and release of the polyplexes were confirmed by immunofluorescence imaging. This study indicates that the modified biopolymer is an auspicious biocompatible non-viral vector with biotin as a promising moiety.

Vascular reconstruction of the decellularized biomatrix for whole-organ engineering-a critical perspective and future strategies

Whole-organ re-engineering is the most challenging goal yet to be achieved in tissue engineering and regenerative medicine. One essential factor in any transplantable and functional tissue engineering is fabricating a perfusable vascular network with macro- and micro-sized blood vessels. Whole-organ development has become more practical with the use of the decellularized organ biomatrix (DOB) as it provides a native biochemical and structural framework for a particular organ. However, reconstructing vasculature and re-endothelialization in the DOB is a highly challenging task and has not been achieved for constructing a clinically transplantable vascularized organ with an efficient perfusable capability. Here, we critically and articulately emphasized factors that have been studied for the vascular reconstruction in the DOB. Furthermore, we highlighted the factors used for vasculature development studies in general and their application in whole-organ vascular reconstruction. We also analyzed in detail the strategies explored so far for vascular reconstruction and angiogenesis in the DOB for functional and perfusable vasculature development. Finally, we discussed some of the crucial factors that have been largely ignored in the vascular reconstruction of the DOB and the future directions that should be addressed systematically.

CRISPR/Cas9 Landscape: Current State and Future Perspectives

CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 is a unique genome editing tool that can be easily used in a wide range of applications, including functional genomics, transcriptomics, epigenetics, biotechnology, plant engineering, livestock breeding, gene therapy, diagnostics, and so on. This review is focused on the current CRISPR/Cas9 landscape, e.g., on Cas9 variants with improved properties, on Cas9-derived and fusion proteins, on Cas9 delivery methods, on pre-existing immunity against CRISPR/Cas9 proteins, anti-CRISPR proteins, and their possible roles in CRISPR/Cas9 function improvement. Moreover, this review presents a detailed outline of CRISPR/Cas9-based diagnostics and therapeutic approaches. Finally, the review addresses the future expansion of genome editors' toolbox with Cas9 orthologs and other CRISPR/Cas proteins.

Current limitations of gene therapy for rare pediatric diseases: Lessons learned from clinical experience with AAV vectors

Gene therapy using adeno-associated viral (AAV) vectors is a promising therapeutic strategy for multiple inherited diseases. Following intravenous injection, AAV vectors carrying a copy of the missing gene or the genome-editing machinery reach their target cells and deliver the genetic material. Several clinical trials are currently ongoing and significant success has already been achieved with at least six AAV gene therapy products with market approval in Europe and the United States. Nonetheless, clinical trials and preclinical studies have uncovered several limitations of AAV gene transfer, which need to be addressed in order to improve the safety and enable the treatment of the largest patient population. Limitations include the occurrence of immune-mediated toxicities, the potential loss of correction in the long run, and the development of neutralizing antibodies against AAV vectors preventing re-administration. In this review, we summarize these limitations and discuss the potential technological developments to overcome them. © 2023 Published by Elsevier Masson SAS on behalf of French Society of Pediatrics.

Development of New Genome Editing Tools for the Treatment of Hyperlipidemia

Hyperlipidemia is a medical condition characterized by high levels of lipids in the blood. It is often associated with an increased risk of cardiovascular diseases such as heart attacks and strokes. Traditional treatment approaches for hyperlipidemia involve lifestyle modifications, dietary changes, and the use of medications like statins. Recent advancements in genome editing technologies, including CRISPR-Cas9, have opened up new possibilities for the treatment of this condition. This review provides a general overview of the main target genes involved in lipid metabolism and highlights the progress made during recent years towards the development of new treatments for dyslipidemia.

A humanized chemogenetic system inhibits murine pain-related behavior and hyperactivity in human sensory neurons

Hyperexcitability in sensory neurons is known to underlie many of the maladaptive changes associated with persistent pain. Chemogenetics has shown promise as a means to suppress such excitability, yet chemogenetic approaches suitable for human applications are needed. PSAM4-GlyR is a modular system based on the human α7 nicotinic acetylcholine and glycine receptors, which responds to inert chemical ligands and the clinically approved drug varenicline. Here, we demonstrated the efficacy of this channel in silencing both mouse and human sensory neurons by the activation of large shunting conductances after agonist administration. Virally mediated expression of PSAM4-GlyR in mouse sensory neurons produced behavioral hyposensitivity upon agonist administration, which was recovered upon agonist washout. Stable expression of the channel led to similar reversible suppression of pain-related behavior even after 10 months of viral delivery. Mechanical and spontaneous pain readouts were also ameliorated by PSAM4-GlyR activation in acute and joint pain inflammation mouse models. Furthermore, suppression of mechanical hypersensitivity generated by a spared nerve injury model of neuropathic pain was also observed upon activation of the channel. Effective silencing of behavioral hypersensitivity was reproduced in a human model of hyperexcitability and clinical pain: PSAM4-GlyR activation decreased the excitability of human-induced pluripotent stem cell-derived sensory neurons and spontaneous activity due to a gain-of-function NaV1.7 mutation causing inherited erythromelalgia. Our results demonstrate the contribution of sensory neuron hyperexcitability to neuropathic pain and the translational potential of an effective, stable, and reversible humanized chemogenetic system for the treatment of pain.

Development of a perfusion process for continuous lentivirus production using stable suspension producer cell lines

The large-scale production of clinical-grade lentiviral vectors (LVs) for gene therapy applications is a remaining challenge. The use of adherent cell lines and methods like transient transfection are cost-intensive and hamper process scalability as well as reproducibility. This study describes the use of two suspension-adapted stable packaging cell lines, called GPRGs and GPRTGs, for the development of a scalable and serum-free LV production process. Both stable packaging cell lines are based on an inducible Tet-off system, thus requiring doxycycline removal for initiation of the virus production. Therefore, we compared different methods for doxycycline removal and inoculated three independent 5 L bioreactors using a scalable induction method by dilution, an acoustic cell washer and manual centrifugation. The bioreactors were inoculated with a stable producer cell line encoding for a LV carrying a clinically relevant gene. LV production was performed in perfusion mode using a cell retention device based on acoustic wave separation. Comparable cell-specific productivities were obtained with all three methods and cumulative functional yields up to 6.36 × 1011 transducing units per bioreactor were generated in a 234-h long process, demonstrating the usability of stable Tet-off cell lines for an easily scalable suspension process. Remarkably, cell viabilities >90% were maintained at high cell densities without compromising productivity throughout the whole process, allowing to further extend the process time. Given its low effects of toxicity during virus production, the presented cell lines are excellent candidates to develop a fully continuous LV production process to overcome the existing bottlenecks in LV manufacturing.

Engineering nanoparticle toolkits for mRNA delivery

The concept of using mRNA to produce its own medicine in situ in the body makes it an ideal drug candidate, holding great potential to revolutionize the way we approach medicine. The unique characteristics of mRNA, as well as its customizable biomedical functions, call for the rational design of delivery systems to protect and transport mRNA molecules. In this review, a nanoparticle toolkit is presented for the development of mRNA-based therapeutics from a drug delivery perspective. Nano-delivery systems derived from either natural systems or chemical synthesis, in the nature of organic or inorganic materials, are summarised. Delivery strategies in controlling the tissue targeting and mRNA release, as well as the role of nanoparticles in building and boosting the activity of mRNA drugs, have also been introduced. In the end, our insights into the clinical and translational development of mRNA nano-drugs are presented.

Genetically Engineered-Cell-Membrane Nanovesicles for Cancer Immunotherapy

The advent of immunotherapy has marked a new era in cancer treatment, offering significant clinical benefits. Cell membrane as drug delivery materials has played a crucial role in enhancing cancer therapy because of their inherent biocompatibility and negligible immunogenicity. Different cell membranes are prepared into cell membrane nanovesicles (CMNs), but CMNs have limitations such as inefficient targeting ability, low efficacy, and unpredictable side effects. Genetic engineering has deepened the critical role of CMNs in cancer immunotherapy, enabling genetically engineered-CMN (GCMN)-based therapeutics. To date, CMNs that are surface modified by various functional proteins have been developed through genetic engineering. Herein, a brief overview of surface engineering strategies for CMNs and the features of various membrane sources is discussed, followed by a description of GCMN preparation methods. The application of GCMNs in cancer immunotherapy directed at different immune targets is addressed as are the challenges and prospects of GCMNs in clinical translation.

Regenerative medicine improve neurodegenerative diseases

Regenerative medicine is a subdivision of medicine that improves methods to regrow, repair or replace unhealthy cells and tissues to return to normal function. Cell therapy, gene therapy, nanomedicine as choices used to cure neurodegenerative disease. Recently, studies related to the treatment of neurodegenerative disorders have been focused on stem cell therapy and Nano-drugs beyond other than regenerative medicine. Hence, by data from experimental models and clinical trials, we review the impact of stem cell therapy, gene therapy, and nanomedicine on the treatment of Alzheimer's disease (AD), Parkinson's disease (PD), and Amyotrophic lateral sclerosis (ALS). Indeed, improved knowledge and continued research on gene therapy and nanomedicine in treating Alzheimer's disease, Parkinson's disease, and Amyotrophic lateral sclerosis lead to advancements in effective and practical treatments for neurodegenerative diseases.

Electroactive nanoinjection platform for intracellular delivery and gene silencing

BACKGROUND

Nanoinjection-the process of intracellular delivery using vertically configured nanostructures-is a physical route that efficiently negotiates the plasma membrane, with minimal perturbation and toxicity to the cells. Nanoinjection, as a physical membrane-disruption-mediated approach, overcomes challenges associated with conventional carrier-mediated approaches such as safety issues (with viral carriers), genotoxicity, limited packaging capacity, low levels of endosomal escape, and poor versatility for cell and cargo types. Yet, despite the implementation of nanoinjection tools and their assisted analogues in diverse cellular manipulations, there are still substantial challenges in harnessing these platforms to gain access into cell interiors with much greater precision without damaging the cell's intricate structure. Here, we propose a non-viral, low-voltage, and reusable electroactive nanoinjection (ENI) platform based on vertically configured conductive nanotubes (NTs) that allows for rapid influx of targeted biomolecular cargos into the intracellular environment, and for successful gene silencing. The localization of electric fields at the tight interface between conductive NTs and the cell membrane drastically lowers the voltage required for cargo delivery into the cells, from kilovolts (for bulk electroporation) to only ≤ 10 V; this enhances the fine control over membrane disruption and mitigates the problem of high cell mortality experienced by conventional electroporation.

RESULTS

Through both theoretical simulations and experiments, we demonstrate the capability of the ENI platform to locally perforate GPE-86 mouse fibroblast cells and efficiently inject a diverse range of membrane-impermeable biomolecules with efficacy of 62.5% (antibody), 55.5% (mRNA), and 51.8% (plasmid DNA), with minimal impact on cells' viability post nanoscale-EP (> 90%). We also show gene silencing through the delivery of siRNA that targets TRIOBP, yielding gene knockdown efficiency of 41.3%.

CONCLUSIONS

We anticipate that our non-viral and low-voltage ENI platform is set to offer a new safe path to intracellular delivery with broader selection of cargo and cell types, and will open opportunities for advanced ex vivo cell engineering and gene silencing.

Intervertebral disc degeneration-Current therapeutic options and challenges

Degeneration of the intervertebral disc (IVD) is a normal part of aging. Due to the spine's declining function and the development of pain, it may affect one's physical health, mental health, and socioeconomic status. Most of the intervertebral disc degeneration (IVDD) therapies today focus on the symptoms of low back pain rather than the underlying etiology or mechanical function of the disc. The deteriorated disc is typically not restored by conservative or surgical therapies that largely focus on correcting symptoms and structural abnormalities. To enhance the clinical outcome and the quality of life of a patient, several therapeutic modalities have been created. In this review, we discuss genetic and environmental causes of IVDD and describe promising modern endogenous and exogenous therapeutic approaches including their applicability and relevance to the degeneration process.

Immunogenicity of Recombinant Adeno-Associated Virus (AAV) Vectors for Gene Transfer

Recombinant adeno-associated viruses (AAVs) have emerged as promising gene delivery vehicles resulting in three US Food and Drug Administration (FDA) and one European Medicines Agency (EMA)-approved AAV-based gene therapies. Despite being a leading platform for therapeutic gene transfer in several clinical trials, host immune responses against the AAV vector and transgene have hampered their widespread application. Multiple factors, including vector design, dose, and route of administration, contribute to the overall immunogenicity of AAVs. The immune responses against the AAV capsid and transgene involve an initial innate sensing. The innate immune response subsequently triggers an adaptive immune response to elicit a robust and specific response against the AAV vector. AAV gene therapy clinical trials and preclinical studies provide important information about the immune-mediated toxicities associated with AAV, yet studies suggest preclinical models fail to precisely predict the outcome of gene delivery in humans. This review discusses the contribution of the innate and adaptive immune response against AAVs, highlighting the challenges and potential strategies to mitigate these responses, thereby enhancing the therapeutic potential of AAV gene therapy.

An mRNA-Based Multiple Antigenic Gene Expression System Delivered by Engineered Salmonella for Severe Fever with Thrombocytopenia Syndrome and Assessment of Its Immunogenicity and Protection Using a Human DC-SIGN-Transduced Mouse Model

Currently, there are no commercial vaccines or therapeutics against severe fever with thrombocytopenia syndrome (SFTS) virus. This study explored an engineered Salmonella as a vaccine carrier to deliver a eukaryotic self-mRNA replicating vector, pJHL204. This vector expresses multiple SFTS virus antigenic genes for the nucleocapsid protein (NP), glycoprotein precursor (Gn/Gc), and nonstructural protein (NS) to induce host immune responses. The engineered constructs were designed and validated through 3D structure modeling. Western blot and qRT-PCR analyses of transformed HEK293T cells confirmed the delivery and expression of the vaccine antigens. Significantly, mice immunized with these constructs demonstrated a cell-mediated and humoral response as balanced Th1/Th2 immunity. The JOL2424 and JOL2425 delivering NP and Gn/Gc generated strong immunoglobulin IgG and IgM antibodies and high neutralizing titers. To further examine the immunogenicity and protection, we utilized a human DC-SIGN receptor transduced mouse model for SFTS virus infection by an adeno-associated viral vector system. Among the SFTSV antigen constructs, the construct with full-length NP and Gn/Gc and the construct with NP and selected Gn/Gc epitopes induced robust cellular and humoral immune responses. These were followed by adequate protection based on viral titer reduction and reduced histopathological lesions in the spleen and liver. In conclusion, these data indicate that recombinant attenuated Salmonella JOL2424 and JOL2425 delivering NP and Gn/Gc antigens of SFTSV are promising vaccine candidates that induce strong humoral and cellular immune responses and protection against SFTSV. Moreover, the data proved that the hDC-SIGN transduced mice as a worthy tool for immunogenicity study for SFTSV.

Applications of tissue-specific and cancer-selective gene promoters for cancer diagnosis and therapy

Current treatment of solid tumors with standard of care chemotherapies, radiation therapy and/or immunotherapies are often limited by severe adverse toxic effects, resulting in a narrow therapeutic index. Cancer gene therapy represents a targeted approach that in principle could significantly reduce undesirable side effects in normal tissues while significantly inhibiting tumor growth and progression. To be effective, this strategy requires a clear understanding of the molecular biology of cancer development and evolution and developing biological vectors that can serve as vehicles to target cancer cells. The advent and fine tuning of omics technologies that permit the collective and spatial recognition of genes (genomics), mRNAs (transcriptomics), proteins (proteomics), metabolites (metabolomics), epiomics (epigenomics, epitranscriptomics, and epiproteomics), and their interactomics in defined complex biological samples provide a roadmap for identifying crucial targets of relevance to the cancer paradigm. Combining these strategies with identified genetic elements that control target gene expression uncovers significant opportunities for developing guided gene-based therapeutics for cancer. The purpose of this review is to overview the current state and potential limitations in developing gene promoter-directed targeted expression of key genes and highlights their potential applications in cancer gene therapy.

Shaping the future from the small scale: dry powder inhalation of CRISPR-Cas9 lipid nanoparticles for the treatment of lung diseases

INTRODUCTION

Most lung diseases are serious conditions resulting from genetic and environmental causes associated with high mortality and severe symptoms. Currently, treatments available have a palliative effect and many targets are still considered undruggable. Gene therapy stands as an attractive approach to offering innovative therapeutic solutions. CRISPRCas9 has established a remarkable potential for genome editing with high selectivity to targeted mutations. To ensure high efficacy with minimum systemic exposure, the delivery and administration route are key components that must be investigated.

AREAS COVERED

This review is focused on the delivery of CRISPRCas9 to the lungs, taking advantage of lipid nanoparticles (LNPs), the most clinically advanced nucleic acid carriers. We also aim to highlight the benefits of pulmonary administration as a local delivery route and the use of spray drying to prepare stable nucleic-acid-based dry powder formulations that can overcome multiple lung barriers.

EXPERT OPINION

Exploring the pulmonary administration to deliver CRISPRCas9 loaded in LNPs as a dry powder increases the chances to achieve high efficacy and reduced adverse effects. CRISPRCas9 loaded in LNP-embedded microparticles has not yet been reported in the literature but has the potential to reach and accumulate in target cells in the lung, thus, enhancing overall efficacy and safety.