Oral Delivery of Nucleic Acid Therapies for Local and Systemic Action

Chitosan nanovectors for siRNA delivery: New horizons for nonviral gene therapy

The growing interest in RNA-based therapeutics has positioned small interfering RNA (siRNA) as a promising tool for gene silencing with high specificity and efficacy. However, the successful clinical application of siRNA therapies requires efficient delivery systems to overcome extracellular and intracellular barriers. Chitosan, a naturally derived polysaccharide, has gained significant attention as a non-viral vector due to its biodegradability, biocompatibility, mucoadhesive properties, and capacity to enhance cellular uptake. These attributes make chitosan an attractive alternative to lipid-based nanoparticles, which currently dominate siRNA delivery platforms. Recent advancements in chitosan-based nanoformulations, including chemical modifications and functionalization strategies, have improved siRNA stability, targeting efficiency, and transfection potential, addressing key limitations such as low bioavailability and immunogenicity. Despite these advances, challenges remain in achieving optimal release kinetics, scalability, and consistent therapeutic efficacy. Future research efforts will focus on engineering chitosan derivatives with enhanced physicochemical properties, integrating multifunctional nanocarriers, and refining formulation strategies to bridge the gap between preclinical research and clinical translation. The continued development of chitosan-based siRNA therapeutics holds significant potential for advancing precision medicine and expanding treatment options for a variety of diseases, including cancer, metabolic disorders, and inflammatory conditions.

Synthetic and Biogenic Materials for Oral Delivery of Biologics: From Bench to Bedside

The development of nucleic acid and protein drugs for oral delivery has lagged behind their production for conventional nonoral routes. Over the past decade, the evolution of DNA- and RNA-based technologies combined with the innovation of state-of-the-art delivery vehicles for nucleic acids has brought rapid advancements to the biopharmaceutical field. Nucleic acid therapies have the potential to achieve long-lasting effects, or even cures, by inhibiting or editing genes, which is not possible with conventional small-molecule drugs. However, challenges and limitations must be addressed before these therapies can provide cures for chronic conditions and rare diseases, rather than only offering temporary relief. Nucleic acids and proteins face premature degradation in the acidic, enzyme-rich stomach environment and are rapidly cleared by the liver. To overcome these challenges, various delivery vehicles have been developed to transport therapeutic compounds to the intestines, where the active compounds are released and gut microbiota and mucosal immune system also play an important role. This review provides a comprehensive overview of the promises and pitfalls associated with the oral route of administration of biologics, current delivery systems, applications of orally delivered therapeutics, and the challenges and considerations for translation of nucleic acid and protein therapeutics into clinical practice.

Deciphering the roles of non-coding RNAs in liposarcoma development: Challenges and opportunities for translational therapeutic advances

Liposarcoma is one of the most prevalent forms of soft tissue sarcoma, and its prognosis is highly dependent on its molecular subtypes. Non-coding RNAs (ncRNAs) like microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) can bind various cellular targets to regulate carcinogenesis. By affecting the expressions and activities of their downstream targets post-transcriptionally, dysregulations of miRNAs can alter different oncogenic signalling pathways, mediating liposarcoma progression. On the contrary, lncRNAs can sponge miRNAs to spare their downstream targets from translational repression, indirectly affecting miRNA-regulated oncogenic activities. In the past 15 years, multiple fundamental and clinical research has shown that different ncRNAs play essential roles in modulating liposarcoma development. Yet, there is a lack of an effective review report that could summarize the findings from various studies. To narrow this literature gap, this review article aimed to compare the findings from different studies on the tumour-regulatory roles of ncRNAs in liposarcoma and to understand how ncRNAs control liposarcoma progression mechanistically. Additionally, the reported findings were critically reviewed to evaluate the translational potentials of various ncRNAs in clinical applications, including employing these ncRNAs as diagnostic and prognostic biomarkers or as therapeutic targets in the management of liposarcoma. Overall, over 15 ncRNAs were reported to play essential roles in modulating different cellular pathways, including apoptosis, WNT/β-catenin, TGF-β/SMAD4, EMT, interleukin, and YAP-associated pathways to influence liposarcoma development. 28 ncRNAs were reported to be upregulated in liposarcoma tissues or circulation, whereas 11 were downregulated, making them potential candidates as liposarcoma diagnostic biomarkers. Among these ncRNAs, measuring the tissues or circulating levels of miR-155 and miR-195 was reported to help detect liposarcoma, differentiate liposarcoma subtypes, and predict the survival and treatment response of liposarcoma patients. Overall, except for a few ncRNAs like miR-155 and miR-195, current evidence to support the use of discussed ncRNAs as biomarkers and therapeutic targets in managing liposarcoma is mainly based on a single-center study with relatively small sample sizes or cell-based studies. Hence, more large-scale multi-center studies should be conducted to further confirm the sensitivity, specificity, and safety of ncRNAs as biomarkers and therapeutic targets. Instead of furthering investigation to confirm the translational values of all the discussed ncRNAs, which can be time- and cost-consuming, it would be more practical to focus on a few ncRNAs, including miR-155 and miR-195, to evaluate if they are sensitive and safe to be used as liposarcoma biomarkers and therapeutic agents or targets.

Nucleic acid drugs: recent progress and future perspectives

High efficacy, selectivity and cellular targeting of therapeutic agents has been an active area of investigation for decades. Currently, most clinically approved therapeutics are small molecules or protein/antibody biologics. Targeted action of small molecule drugs remains a challenge in medicine. In addition, many diseases are considered 'undruggable' using standard biomacromolecules. Many of these challenges however, can be addressed using nucleic therapeutics. Nucleic acid drugs (NADs) are a new generation of gene-editing modalities characterized by their high efficiency and rapid development, which have become an active research topic in new drug development field. However, many factors, including their low stability, short half-life, high immunogenicity, tissue targeting, cellular uptake, and endosomal escape, hamper the delivery and clinical application of NADs. Scientists have used chemical modification techniques to improve the physicochemical properties of NADs. In contrast, modified NADs typically require carriers to enter target cells and reach specific intracellular locations. Multiple delivery approaches have been developed to effectively improve intracellular delivery and the in vivo bioavailability of NADs. Several NADs have entered the clinical trial recently, and some have been approved for therapeutic use in different fields. This review summarizes NADs development and evolution and introduces NADs classifications and general delivery strategies, highlighting their success in clinical applications. Additionally, this review discusses the limitations and potential future applications of NADs as gene therapy candidates.

Alternative routes for parenteral nucleic acid delivery and related hurdles: highlights in RNA delivery

INTRODUCTION

Nucleic acid-based therapies are promising advancements in medicine. They offer unparalleled efficacy in treating previously untreatable diseases through precise gene manipulation techniques. However, the challenge of achieving targeted delivery to specific cells remains a significant obstacle.

AREAS COVERED

This review thoroughly examines the physicochemical properties of nucleic acids, focusing on their interaction with carriers and exploring various delivery routes, including oral, pulmonary, ocular, and dermal routes. It also examines the nonviral vector delivery efficiency of nucleic acids, focusing on RNA, and provides regulatory landscapes.

EXPERT OPINION

The role of carriers in improving the effectiveness of nucleic acid-based therapies is emphasized. The discussion of published results covers regulatory frameworks, including insights into European Medicines Agency guidelines. It highlights cutting-edge biotechnological innovations and a quality-by-design approach that could facilitate clinical translation and smooth regulatory obstacles.

mRNA vaccines: a new era in vaccine development

The advent of RNA therapy, particularly through the development of mRNA cancer vaccines, has ushered in a new era in the field of oncology. This article provides a concise overview of the key principles, recent advancements, and potential implications of mRNA cancer vaccines as a groundbreaking modality in cancer treatment. mRNA cancer vaccines represent a revolutionary approach to combatting cancer by leveraging the body's innate immune system. These vaccines are designed to deliver specific mRNA sequences encoding cancer-associated antigens, prompting the immune system to recognize and mount a targeted response against malignant cells. This personalized and adaptive nature of mRNA vaccines holds immense potential for addressing the heterogeneity of cancer and tailoring treatments to individual patients. Recent breakthroughs in the development of mRNA vaccines, exemplified by the success of COVID-19 vaccines, have accelerated their application in oncology. The mRNA platform's versatility allows for the rapid adaptation of vaccine candidates to various cancer types, presenting an agile and promising avenue for therapeutic intervention. Clinical trials of mRNA cancer vaccines have demonstrated encouraging results in terms of safety, immunogenicity, and efficacy. Pioneering candidates, such as BioNTech's BNT111 and Moderna's mRNA-4157, have exhibited promising outcomes in targeting melanoma and solid tumors, respectively. These successes underscore the potential of mRNA vaccines to elicit robust and durable anti-cancer immune responses. While the field holds great promise, challenges such as manufacturing complexities and cost considerations need to be addressed for widespread adoption. The development of scalable and cost-effective manufacturing processes, along with ongoing clinical research, will be pivotal in realizing the full potential of mRNA cancer vaccines. Overall, mRNA cancer vaccines represent a cutting-edge therapeutic approach that holds the promise of transforming cancer treatment. As research progresses, addressing challenges and refining manufacturing processes will be crucial in advancing these vaccines from clinical trials to mainstream oncology practice, offering new hope for patients in the fight against cancer.

Advancing cancer treatments: The role of oligonucleotide-based therapies in driving progress

Although recent advancements in cancer immunology have resulted in the approval of numerous immunotherapies, minimal progress has been observed in addressing hard-to-treat cancers. In this context, therapeutic oligonucleotides, including interfering RNAs, antisense oligonucleotides, aptamers, and DNAzymes, have gained a central role in cancer therapeutic approaches due to their capacity to regulate gene expression and protein function with reduced toxicity compared with conventional chemotherapeutics. Nevertheless, systemic administration of naked oligonucleotides faces many extra- and intracellular challenges that can be overcome by using effective delivery systems. Thus, viral and non-viral carriers can improve oligonucleotide stability and intracellular uptake, enhance tumor accumulation, and increase the probability of endosomal escape while minimizing other adverse effects. Therefore, gaining more insight into fundamental mechanisms of actions of various oligonucleotides and the challenges posed by naked oligonucleotide administration, this article provides a comprehensive review of the recent progress on oligonucleotide delivery systems and an overview of completed and ongoing cancer clinical trials that can shape future oncological treatments.

Oral Piwi-Interacting RNA Delivery Mediated by Green Tea-Derived Exosome-Like Nanovesicles for the Treatment of Aortic Dissection

Aortic dissection (AD) is a severe cardiovascular disease necessitating active therapeutic strategies for early intervention and prevention. Nucleic acid drugs, known for their potent molecule-targeting therapeutic properties, offer potential for genetic suppression of AD. Piwi-interacting RNAs, a class of small RNAs, hold promise for managing cardiovascular diseases. Limited research on these RNAs and AD exists. This study demonstrates that an antagomir targeting heart-apoptosis-associated piRNA (HAAPIR) effectively regulates vascular remodeling, mitigating AD occurrence and progression through the myocyte enhancer factor 2D (Mef2D) and matrix metallopeptidase 9 (MMP9) pathways. Green tea-derived plant exosome-like nanovesicles (PELNs) are used for oral administration of antagomir. The antagomir-HAAPIR-nanovesicle complex, after purification and optimization, exhibits a high packing rate, while the antagomir is resistant to enzyme digestion. Administered to mice, the complex targets the aortic lesion, reducing AD incidence and improving survival. Moreover, MMP9 and Mef2D expression decrease significantly, inhibiting the phenotypic conversion of human aortic smooth muscle cells. PELNs encapsulate the antagomir-HAAPIR complex, maintaining stability, mediating transport into the bloodstream, and delivering Piwi-interacting RNAs to AD sites. Thus, HAAPIR is a potential target for persistent clinical AD prevention and treatment, and nanovesicle-encapsulated nucleic acids offer a promising cardiovascular disease treatment, providing insights for other therapeutic targets.

From Nature-Sourced Polysaccharide Particles to Advanced Functional Materials

Polysaccharides constitute over 90% of the carbohydrate mass in nature, which makes them a promising feedstock for manufacturing sustainable materials. Polysaccharide particles (PSPs) are used as effective scavengers, carriers of chemical and biological cargos, and building blocks for the fabrication of macroscopic materials. The biocompatibility and degradability of PSPs are advantageous for their uses as biomaterials with more environmental friendliness. This review highlights the progresses in PSP applications as advanced functional materials, by describing PSP extraction, preparation, and surface functionalization with a variety of functional groups, polymers, nanoparticles, and biologically active species. This review also outlines the fabrication of PSP-derived macroscopic materials, as well as their applications in soft robotics, sensing, scavenging, water harvesting, drug delivery, and bioengineering. The paper is concluded with an outlook providing perspectives in the development and applications of PSP-derived materials.

Solidification and oral delivery of biologics to the colon- A review

The oral delivery of biologics such as therapeutic proteins, peptides and oligonucleotides for the treatment of colon related diseases has been the focus of increasing attention over the last years. However, the major disadvantage of these macromolecules is their degradation propensity in liquid state which can lead to the undesirable and complete loss of function. Therefore, to increase the stability of the biologic and reduce their degradation propensity, formulation techniques such as solidification can be performed to obtain a stable solid dosage form for oral administration. Due to their fragility, stress exerted on the biologic during solidification has to be reduced with the incorporation of stabilizing excipients into the formulation. This review focuses on the state-of-the-art solidification techniques required to obtain a solid dosage form for the oral delivery of biologics to the colon and the use of suitable excipients for adequate stabilization upon solidification. The solidifying processes discussed within this review are spray drying, freeze drying, bead coating and also other techniques such as spray freeze drying, electro spraying, vacuum- and supercritical fluid drying. Further, the colon as site of absorption in both healthy and diseased state is critically reviewed and possible oral delivery systems for biologics are discussed.

Delivery of biologics: Topical administration

Biologics are unaffordable to a large majority of the global population because of prohibitively expensive fermentation systems, purification and the requirement for cold chain for storage and transportation. Limitations of current production and delivery systems of biologics were evident during the recent pandemic when <2.5% of vaccines produced were available to low-income countries and ∼19 million doses were discarded in Africa due to lack of cold-chain infrastructure. Among FDA-approved biologics since 2015, >90% are delivered using invasive methods. While oral or topical drugs are highly preferred by patients because of their affordability and convenience, only two oral drugs have been approved by FDA since 2015. A newly launched oral biologic costs only ∼3% of the average cost of injectable biologics because of the simplified regulatory approval process by elimination of prohibitively expensive fermentation, purification, cold storage/transportation. In addition, the cost of developing a new biologic injectable product (∼$2.5 billion) has been dramatically reduced through oral or topical delivery. Topical delivery has the unique advantage of targeted delivery of high concentration protein drugs, without getting diluted in circulating blood. However, only very few topical drugs have been approved by the FDA. Therefore, this review highlights recent advances in oral or topical delivery of proteins at early or advanced stages of human clinical trials using chewing gums, patches or sprays, or nucleic acid drugs directly, or in combination with, nanoparticles and offers future directions.

Cracking the intestinal lymphatic system window utilizing oral delivery vehicles for precise therapy

Oral administration is preferred over other drug delivery methods due to its safety, high patient compliance, ease of ingestion without discomfort, and tolerance of a wide range of medications. However, oral drug delivery is limited by the poor oral bioavailability of many drugs, caused by extreme conditions and absorption challenges in the gastrointestinal tract. This review thoroughly discusses the targeted drug vehicles to the intestinal lymphatic system (ILS). It explores the structure and physiological barriers of the ILS, highlighting its significance in dietary lipid and medication absorption and transport. The review presents various approaches to targeting the ILS using spatially precise vehicles, aiming to enhance bioavailability, achieve targeted delivery, and reduce first-pass metabolism with serve in clinic. Furthermore, the review outlines several methods for leveraging these vehicles to open the ILS window, paving the way for potential clinical applications in cancer treatment and oral vaccine delivery. By focusing on targeted drug vehicles to the ILS, this article emphasizes the critical role of these strategies in improving therapeutic efficacy and patient outcomes. Overall, this article emphasizes the critical role of targeted drug vehicles to the ILS and the potential impact of these strategies on improving therapeutic efficacy and patient outcomes.