Cationic nanoemulsions as nucleic acids delivery systems

Pharmaceutical strategies for optimized mRNA expression

Messenger RNA (mRNA)-based immunotherapies and protein in situ production therapies hold great promise for addressing theoretically all the diseases characterized by aberrant protein levels. The safe, stable, and precise delivery of mRNA to target cells via appropriate pharmaceutical strategies is a prerequisite for its optimal efficacy. In this review, we summarize the structural characteristics, mode of action, development prospects, and limitations of existing mRNA delivery systems from a pharmaceutical perspective, with an emphasis on the impacts from formulation adjustments and preparation techniques of non-viral vectors on mRNA stability, target site accumulation and transfection efficiency. In addition, we introduce strategies for synergistical combination of mRNA and small molecules to augment the potency or mitigate the adverse effects of mRNA therapeutics. Lastly, we delve into the challenges impeding the development of mRNA drugs while exploring promising avenues for future advancements.

mRNA vaccines in tumor targeted therapy: mechanism, clinical application, and development trends

Malignant tumors remain a primary cause of human mortality. Among the various treatment modalities for neoplasms, tumor vaccines have consistently shown efficacy and promising potential. These vaccines offer advantages such as specificity, safety, and tolerability, with mRNA vaccines representing promising platforms. By introducing exogenous mRNAs encoding antigens into somatic cells and subsequently synthesizing antigens through gene expression systems, mRNA vaccines can effectively induce immune responses. Katalin Karikó and Drew Weissman were awarded the 2023 Nobel Prize in Physiology or Medicine for their great contributions to mRNA vaccine research. Compared with traditional tumor vaccines, mRNA vaccines have several advantages, including rapid preparation, reduced contamination, nonintegrability, and high biodegradability. Tumor-targeted therapy is an innovative treatment modality that enables precise targeting of tumor cells, minimizes damage to normal tissues, is safe at high doses, and demonstrates great efficacy. Currently, targeted therapy has become an important treatment option for malignant tumors. The application of mRNA vaccines in tumor-targeted therapy is expanding, with numerous clinical trials underway. We systematically outline the targeted delivery mechanism of mRNA vaccines and the mechanism by which mRNA vaccines induce anti-tumor immune responses, describe the current research and clinical applications of mRNA vaccines in tumor-targeted therapy, and forecast the future development trends of mRNA vaccine application in tumor-targeted therapy.

An Overview of Nanoparticle-Based Delivery Platforms for mRNA Vaccines for Treating Cancer

With its unique properties and potential applications, nanoparticle-based delivery platforms for messenger RNA (mRNA) vaccines have gained significant attention in recent years. Nanoparticles have the advantages of enhancing immunogenicity, targeting delivery, and improving stability, providing a new solution for drug and vaccine delivery. In some clinical studies, a variety of nanoparticle delivery platforms have been gradually applied to a wide range of vaccine applications. Current research priorities are exploring various types of nanoparticles as vaccine delivery systems to enhance vaccine stability and immunogenicity. Lipid nanoparticles (LNPs) have shown promising potential in preclinical and clinical studies on the efficient delivery of antigens to immune cells. Moreover, lipid nanoparticles and other nanoparticles for nucleic acids, especially for mRNA delivery systems, have shown vast potential for vaccine development. In this review, we present various vaccine platforms with an emphasis on nanoparticles as mRNA vaccine delivery vehicles. We describe several novel nanoparticle delivery platforms for mRNA vaccines, such as lipid-, polymer-, and protein-based nanoparticles. In addition, we provide an overview of the anti-tumor immunity of nanovaccines against different tumors in cancer immunotherapy. Finally, we outline future perspectives and remaining challenges for this promising technology of nanoparticle-based delivery platforms for vaccines.

Liposomes and Lipid Droplets Display a Reversal of Charge-Induced Hydration Asymmetry

The unique properties of water are critical for life. Water molecules have been reported to hydrate cations and anions asymmetrically in bulk water, being a key element in the balance of biochemical interactions. We show here that this behavior extends to charged lipid nanoscale interfaces. Charge hydration asymmetry was investigated by using nonlinear light scattering methods on lipid nanodroplets and liposomes. Nanodroplets covered with negatively charged lipids induce strong water ordering, while droplets covered with positively charged lipids induce negligible water ordering. Surprisingly, this charge-induced hydration asymmetry is reversed around liposomes. This opposite behavior in charge hydration asymmetry is caused by a delicate balance of electrostatic and hydrogen-bonding interactions. These findings highlight the importance of not only the charge state but also the specific distribution of neutral and charged lipids in cellular membranes.

Lipid carriers for mRNA delivery

Messenger RNA (mRNA) is the template for protein biosynthesis and is emerging as an essential active molecule to combat various diseases, including viral infection and cancer. Especially, mRNA-based vaccines, as a new type of vaccine, have played a leading role in fighting against the current global pandemic of COVID-19. However, the inherent drawbacks, including large size, negative charge, and instability, hinder its use as a therapeutic agent. Lipid carriers are distinguishable and promising vehicles for mRNA delivery, owning the capacity to encapsulate and deliver negatively charged drugs to the targeted tissues and release cargoes at the desired time. Here, we first summarized the structure and properties of different lipid carriers, such as liposomes, liposome-like nanoparticles, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, nanoemulsions, exosomes and lipoprotein particles, and their applications in delivering mRNA. Then, the development of lipid-based formulations as vaccine delivery systems was discussed and highlighted. Recent advancements in the mRNA vaccine of COVID-19 were emphasized. Finally, we described our future vision and perspectives in this field.

Circular RNA vaccine in disease prevention and treatment

CircRNAs are a class of single-stranded RNAs with covalently linked head-to-tail topology. In the decades since its initial discovery, their biogenesis, regulation, and function have rapidly disclosed, permitting a better understanding and adoption of them as new tools for medical applications. With the development of biotechnology and molecular medicine, artificial circRNAs have been engineered as a novel class of vaccines for disease treatment and prevention. Unlike the linear mRNA vaccine which applications were limited by its instability, inefficiency, and innate immunogenicity, circRNA vaccine which incorporate internal ribosome entry sites (IRESs) and open reading frame (ORF) provides an improved approach to RNA-based vaccination with safety, stability, simplicity of manufacture, and scalability. However, circRNA vaccines are at an early stage, and their optimization, delivery and applications require further development and evaluation. In this review, we comprehensively describe circRNA vaccine, including their history and superiority. We also summarize and discuss the current methodological research for circRNA vaccine preparation, including their design, synthesis, and purification. Finally, we highlight the delivery options of circRNA vaccine and its potential applications in diseases treatment and prevention. Considering their unique high stability, low immunogenicity, protein/peptide-coding capacity and special closed-loop construction, circRNA vaccine, and circRNA-based therapeutic platforms may have superior application prospects in a broad range of diseases.

Recent Advances in Messenger Ribonucleic Acid (mRNA) Vaccines and Their Delivery Systems: A Review

Messenger ribonucleic acid (mRNA) was found as the intermediary that transfers genetic information from DNA to ribosomes for protein synthesis in 1961. The emergency use authorization of the two covid-19 mRNA vaccines, BNT162b2 and mRNA-1273, is a significant achievement in the history of vaccine development. Because they are generated in a cell-free environment using the in vitro transcription (IVT) process, mRNA vaccines are risk-free. Moreover, chemical modifications to the mRNA molecule, such as cap structures and changed nucleosides, have proved critical in overcoming immunogenicity concerns, achieving sustained stability, and achieving effective, accurate protein production in vivo. Several vaccine delivery strategies (including protamine, lipid nanoparticles (LNPs), polymers, nanoemulsions, and cell-based administration) were also optimized to load and transport RNA into the cytosol. LNPs, which are composed of a cationic or a pH-dependent ionizable lipid layer, a polyethylene glycol (PEG) component, phospholipids, and cholesterol, are the most advanced systems for delivering mRNA vaccines. Moreover, modifications of the four components that make up the LNPs showed to increase vaccine effectiveness and reduce side effects. Furthermore, the introduction of biodegradable lipids improved LNP biocompatibility. Furthermore, mRNA-based therapies are expected to be effective treatments for a variety of refractory conditions, including infectious diseases, metabolic genetic diseases, cancer, cardiovascular and cerebrovascular diseases. Therefore, the present review aims to provide the scientific community with up-to-date information on mRNA vaccines and their delivery systems.

Development and Characterization of Cationic Nanostructured Lipid Carriers as Drug Delivery Systems for miRNA-27a

Although miRNA-27a has been identified as a promising candidate for miRNA mimic therapy of obesity, its application is limited due to enzymatic degradation and low membrane permeation. To overcome these problems, we developed cationic nanostructured lipid carriers (cNLCs) using high-pressure homogenization and used them as non-viral carriers for the anti-adipogenic miRNA-27a. Cargo-free octadecylamine-containing NLCs and miRNA/cNLC complexes were characterized regarding particle size, size distributions, zeta potential, pH values, particle topography and morphology, and entrapment efficacy. Furthermore, the cytotoxicity and cellular uptake of the miRNA/cNLC complex in the 3T3-L1 cell line were investigated. The investigation of the biological effect of miRNA-27a on adipocyte development and an estimation of the accumulated Oil-Red-O (ORO) dye in lipid droplets in mature adipocytes were assessed with light microscopy and absorbance measurements. The obtained data show that cNLCs represent a suitable DDS for miRNAs, as miRNA/cNLC particles are rapidly formed through non-covalent complexation due to electrostatic interactions between both components. The miRNA-27a/cNLC complex induced an anti-adipogenic effect on miRNA-27a by reducing lipid droplet accumulation in mature adipocytes, indicating that this approach might be used as a new therapeutic strategy for miRNA mimic replacement therapies in the prevention or treatment of obesity and obesity-related disorders.

Lipid-based colloidal nanoparticles for applications in targeted vaccine delivery

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

mRNA-Based Therapeutics in Cancer Treatment

Over the past two decades, significant technological innovations have led to messenger RNA (mRNA) becoming a promising option for developing prophylactic and therapeutic vaccines, protein replacement therapies, and genome engineering. The success of the two COVID-19 mRNA vaccines has sparked new enthusiasm for other medical applications, particularly in cancer treatment. In vitro-transcribed (IVT) mRNAs are structurally designed to resemble naturally occurring mature mRNA. Delivery of IVT mRNA via delivery platforms such as lipid nanoparticles allows host cells to produce many copies of encoded proteins, which can serve as antigens to stimulate immune responses or as additional beneficial proteins for supplements. mRNA-based cancer therapeutics include mRNA cancer vaccines, mRNA encoding cytokines, chimeric antigen receptors, tumor suppressors, and other combination therapies. To better understand the current development and research status of mRNA therapies for cancer treatment, this review focused on the molecular design, delivery systems, and clinical indications of mRNA therapies in cancer.

Advances of mRNA vaccine in tumor: a maze of opportunities and challenges

High-frequency mutations in tumor genomes could be exploited as an asset for developing tumor vaccines. In recent years, with the tremendous breakthrough in genomics, intelligence algorithm, and in-depth insight of tumor immunology, it has become possible to rapidly target genomic alterations in tumor cell and rationally select vaccine targets. Among a variety of candidate vaccine platforms, the early application of mRNA was limited by instability low efficiency and excessive immunogenicity until the successful development of mRNA vaccines against SARS-COV-2 broken of technical bottleneck in vaccine preparation, allowing tumor mRNA vaccines to be prepared rapidly in an economical way with good performance of stability and efficiency. In this review, we systematically summarized the classification and characteristics of tumor antigens, the general process and methods for screening neoantigens, the strategies of vaccine preparations and advances in clinical trials, as well as presented the main challenges in the current mRNA tumor vaccine development.

RNA-targeting strategies as a platform for ocular gene therapy

Genetic medicine is offering hope as new therapies are emerging for many previously untreatable diseases. The eye is at the forefront of these advances, as exemplified by the approval of Luxturna® by the United States Food and Drug Administration (US FDA) in 2017 for the treatment of one form of Leber Congenital Amaurosis (LCA), an inherited blindness. Luxturna® was also the first in vivo human gene therapy to gain US FDA approval. Numerous gene therapy clinical trials are ongoing for other eye diseases, and novel delivery systems, discovery of new drug targets and emerging technologies are currently driving the field forward. Targeting RNA, in particular, is an attractive therapeutic strategy for genetic disease that may have safety advantages over alternative approaches by avoiding permanent changes in the genome. In this regard, antisense oligonucleotides (ASO) and RNA interference (RNAi) are the currently popular strategies for developing RNA-targeted therapeutics. Enthusiasm has been further fuelled by the emergence of clustered regularly interspersed short palindromic repeats (CRISPR)-CRISPR associated (Cas) systems that allow targeted manipulation of nucleic acids. RNA-targeting CRISPR-Cas systems now provide a novel way to develop RNA-targeted therapeutics and may provide superior efficiency and specificity to existing technologies. In addition, RNA base editing technologies using CRISPR-Cas and other modalities also enable precise alteration of single nucleotides. In this review, we showcase advances made by RNA-targeting systems for ocular disease, discuss applications of ASO and RNAi technologies, highlight emerging CRISPR-Cas systems and consider the implications of RNA-targeting therapeutics in the development of future drugs to treat eye disease.

Gene editing strategies to treat lysosomal disorders: The example of mucopolysaccharidoses

Lysosomal storage disorders are a group of progressive multisystemic hereditary diseases with a combined incidence of 1:4,800. Here we review the clinical and molecular characteristics of these diseases, with a special focus on Mucopolysaccharidoses, caused primarily by the lysosomal storage of glycosaminoglycans. Different gene editing techniques can be used to ameliorate their symptoms, using both viral and nonviral delivery methods. Whereas these are still being tested in animal models, early results of phase I/II clinical trials of gene therapy show how this technology may impact the future treatment of these diseases. Hurdles related to specific hard-to-reach organs, such as the central nervous system, heart, joints, and the eye must be tackled. Finally, the regulatory framework necessary to advance into clinical practice is also discussed.

Enhancing the Effect of Nucleic Acid Vaccines in the Treatment of HPV-Related Cancers: An Overview of Delivery Systems

Prophylactic vaccines against human papillomavirus (HPV) have proven efficacy in those who have not been infected by the virus. However, they do not benefit patients with established tumors. Therefore, the development of therapeutic options for HPV-related malignancies is critical. Third-generation vaccines based on nucleic acids are fast and simple approaches to eliciting adaptive immune responses. However, techniques to boost immunogenicity, reduce degradation, and facilitate their capture by immune cells are frequently required. One option to overcome this constraint is to employ delivery systems that allow selective antigen absorption and help modulate the immune response. This review aimed to discuss the influence of these different systems on the response generated by nucleic acid vaccines. The results indicate that delivery systems based on lipids, polymers, and microorganisms such as yeasts can be used to ensure the stability and transport of nucleic acid vaccines to their respective protein synthesis compartments. Thus, in view of the limitations of nucleic acid-based vaccines, it is important to consider the type of delivery system to be used-due to its impact on the immune response and desired final effect.

Ivermectin Enhanced Antitumor Activity of Resiquimod in a Co-Loaded Squalene Emulsion

Immunogenic cell death (ICD) plays an important role in sensitizing tumor cells to antigen-presenting cells followed by antitumor immunity. However, a successful antitumor response by ICD requires both apoptotic tumor microenvironments and activated immune systems. Ivermectin (IVM) has been shown to induce cell apoptosis through autophagy which can be a great candidate for ICD therapy. However, a single treatment of IVM-free drug is not an ideal anticancer therapy due to its anti-inflammatory effects and cytotoxicity. In the present study, IVM was shown to enhance the ICD process in addition to the treatment of resiquimod (R848), a TLR7/8 agonist, when co-loaded in a squalene-based nanoemulsion (NE). R848-IVM co-loaded NE was developed and characterized in vitro. Antitumor activity of R848-IVM NE was also evaluated in vitro and in vivo. R848-IVM NE exhibited long-term stability and reduced cytotoxicity by IVM. In vivo studies demonstrated that IVM significantly augments the ICD by upregulating Cd8a and releasing HMGB1 in tumor tissue, which could enhance R848-driven antitumor immunity. R848-IVM NE treatment showed strong antitumor activity with over 80% tumor growth inhibition, suggesting a potential combination therapy of systemic co-delivering IVM with TLR agonists against solid cancer.

Ocular Drug Delivery: Advancements and Innovations

Ocular drug delivery has been significantly advanced for not only pharmaceutical compounds, such as steroids, nonsteroidal anti-inflammatory drugs, immune modulators, antibiotics, and so forth, but also for the rapidly progressed gene therapy products. For conventional non-gene therapy drugs, appropriate surgical approaches and releasing systems are the main deliberation to achieve adequate treatment outcomes, whereas the scope of “drug delivery” for gene therapy drugs further expands to transgene construct optimization, vector selection, and vector engineering. The eye is the particularly well-suited organ as the gene therapy target, owing to multiple advantages. In this review, we will delve into three main aspects of ocular drug delivery for both conventional drugs and adeno-associated virus (AAV)-based gene therapy products: (1) the development of AAV vector systems for ocular gene therapy, (2) the innovative carriers of medication, and (3) administration routes progression.

mRNA-based therapeutics: powerful and versatile tools to combat diseases

The therapeutic use of messenger RNA (mRNA) has fueled great hope to combat a wide range of incurable diseases. Recent rapid advances in biotechnology and molecular medicine have enabled the production of almost any functional protein/peptide in the human body by introducing mRNA as a vaccine or therapeutic agent. This represents a rising precision medicine field with great promise for preventing and treating many intractable or genetic diseases. In addition, in vitro transcribed mRNA has achieved programmed production, which is more effective, faster in design and production, as well as more flexible and cost-effective than conventional approaches that may offer. Based on these extraordinary advantages, mRNA vaccines have the characteristics of the swiftest response to large-scale outbreaks of infectious diseases, such as the currently devastating pandemic COVID-19. It has always been the scientists’ desire to improve the stability, immunogenicity, translation efficiency, and delivery system to achieve efficient and safe delivery of mRNA. Excitingly, these scientific dreams have gradually been realized with the rapid, amazing achievements of molecular biology, RNA technology, vaccinology, and nanotechnology. In this review, we comprehensively describe mRNA-based therapeutics, including their principles, manufacture, application, effects, and shortcomings. We also highlight the importance of mRNA optimization and delivery systems in successful mRNA therapeutics and discuss the key challenges and opportunities in developing these tools into powerful and versatile tools to combat many genetic, infectious, cancer, and other refractory diseases.

Emerging trends and promises of nanoemulsions in therapeutics of infectious diseases

Infectious diseases are prevalent and have contributed to high morbidity rates by creating havoc like the COVID-19, 1918 influenza and Black Death (the plague) pandemics. Antimicrobial resistance, adverse effects, the emergence of co-infections and the high cost of antimicrobial therapies are major threats to the health of people worldwide while impacting overall healthcare and socioeconomic development. One of the most common ways to address this issue lies in improving existing antimicrobial drug-delivery systems. Nanoemulsions and their modified forms have been successfully employed for the delivery of antimicrobials to treat infectious diseases. In this article, the authors comprehensively reviewed how nanoemulsion-based formulation systems are shifting the paradigm for therapeutics and diagnosis of infectious diseases.

Estimating the two graph dextran-stearic acid-spermine polymers based on iron oxide nanoparticles as carrier for gene delivery

Non-viral gene carriers have shown noticeable potential in gene delivery because of limited side effects, biocompatibility, simplicity, and the ability to take advantage of electrostatic interactions. However, the low transfection rate of non-viral vectors under physiological conditions is controversial. This study aimed to decrease the transfection time using a static magnetic field. We used self-assembled cationic polysaccharides based on dextran-stearic acid-spermine (DSASP) conjugates associated with Fe₃ O₄ superparamagnetic nanoparticles to investigate their potential as gene carriers to promote the target delivery. Our findings illustrate that the magnetic nanoparticles are spherical with a positive surface charge and exhibit superparamagnetic behavior. The DSASP-pDNA/Fe₃ O₄ complexes offered a strong pDNA condensation, protection against DNase degradation, and significant cell viability in HEK 293T cells. Our results demonstrated that although conjugation of stearic acid could play a role in transfection efficiency, DSASP magnetic carriers with more spermine derivatives showed better affinity between the amphiphilic polymer and the negatively charged cell membrane.

Nanoemulsions as Gene Delivery in Mucopolysaccharidosis Type I-A Mini-Review

Mucopolysaccharidosis type I (MPS I) is a rare monogenic disease in which glycosaminoglycans' abnormal metabolism leads to the storage of heparan sulfate and dermatan sulfate in various tissues. It causes its damage and impairment. Patients with the severe form of MPS I usually do not live up to the age of ten. Currently, the therapy is based on multidisciplinary care and enzyme replacement therapy or hematopoietic stem cell transplantation. Applying gene therapy might benefit the MPS I patients because it overcomes the typical limitations of standard treatments. Nanoparticles, including nanoemulsions, are used more and more in medicine to deliver a particular drug to the target cells. It allows for creating a specific, efficient therapy method in MPS I and other lysosomal storage disorders. This article briefly presents the basics of nanoemulsions and discusses the current state of knowledge about their usage in mucopolysaccharidosis type I.

The Potential of Nanomedicine to Unlock the Limitless Applications of mRNA

The year 2020 was a turning point in the way society perceives science. Messenger RNA (mRNA) technology finally showed and shared its potential, starting a new era in medicine. However, there is no doubt that commercialization of these vaccines would not have been possible without nanotechnology, which has finally answered the long-term question of how to deliver mRNA in vivo. The aim of this review is to showcase the importance of this scientific milestone for the development of additional mRNA therapeutics. Firstly, we provide a full description of the marketed vaccine formulations and disclose LNPs' pharmaceutical properties, including composition, structure, and manufacturing considerations Additionally, we review different types of lipid-based delivery technologies currently in preclinical and clinical development, namely lipoplexes and cationic nanoemulsions. Finally, we highlight the most promising clinical applications of mRNA in different fields such as vaccinology, immuno-oncology, gene therapy for rare genetic diseases and gene editing using CRISPR Cas9.

Poly (β amino esters) copolymers: Novel potential vectors for delivery of genes and related therapeutics

The unique properties of polymers have performed an essential contribution to the drug delivery system by providing an outstanding platform for the delivery of macromolecules and genes. However, the block copolymers have been the subject of many recently published works whose results have demonstrated excellent performance in drug targeting. Poly(β-amino esters) (PβAEs) copolymers are the synthetic cationic polymers that are tailored by chemically joining PβAEs with other additives to demonstrate extraordinary efficiency in designing pre-defined and pre-programmed nanostructures, site-specific delivery, andovercoming the distinct cellular barriers. Different compositional and structural libraries could be generated by combinatorial chemistry and by the addition of various novel functional additives that fulfill the multiple requirements of targeted delivery. These intriguing attributes allow PβAE-copolymers to have customized therapeutic functions such as excellent encapsulation capacity, high stability, and stimuli-responsive release. Here, we give an overview of PβAE copolymers-based formulations along with focusing on most notable improvements such as structural modifications, bio-conjugations, and stimuli-responsive approaches, for safe and effective nucleic acids delivery.

A Squalene-Based Nanoemulsion for Therapeutic Delivery of Resiquimod

Agonists for toll-like receptors (TLRs) have shown promising activities against cancer. In the present study, a squalene-based nanoemulsion (NE) was loaded with resiquimod, a TLR7/8 agonist for therapeutic delivery. R848 NE was developed and characterized for long-term stability. In vitro and in vivo antitumor immunity of R848 NE were also evaluated in combination with SD-101, a CpG-containing TLR9 agonist. In vitro studies demonstrated strong long-term stability and immune responses to R848 NE. When combined with SD-101, strong antitumor activity was observed in MC38 murine colon carcinoma model with over 80% tumor growth inhibition. The combination treatment showed a 4-fold increase in systemic TNFa production and a 2.6-fold increase in Cd8a expression in tumor tissues, suggesting strong cell-mediated immune responses against the tumor. The treatment not only demonstrated a strong antitumor immunity by TLR7/8 and TLR9 activations but also induced PD-L1 upregulation in tumors, suggesting a potential therapeutic synergy with immune checkpoint inhibitors.

Application of Non-Viral Vectors in Drug Delivery and Gene Therapy

Vectors and carriers play an indispensable role in gene therapy and drug delivery. Non-viral vectors are widely developed and applied in clinical practice due to their low immunogenicity, good biocompatibility, easy synthesis and modification, and low cost of production. This review summarized a variety of non-viral vectors and carriers including polymers, liposomes, gold nanoparticles, mesoporous silica nanoparticles and carbon nanotubes from the aspects of physicochemical characteristics, synthesis methods, functional modifications, and research applications. Notably, non-viral vectors can enhance the absorption of cargos, prolong the circulation time, improve therapeutic effects, and provide targeted delivery. Additional studies focused on recent innovation of novel synthesis techniques for vector materials. We also elaborated on the problems and future research directions in the development of non-viral vectors, which provided a theoretical basis for their broad applications.

Modulation of Colorectal Tumor Behavior via lncRNA TP53TG1-Lipidic Nanosystem

Long non-coding RNAs (lncRNAs) are an emerging group of RNAs with a crucial role in cancer pathogenesis. In gastrointestinal cancers, TP53 target 1 (TP53TG1) is an epigenetically regulated lncRNA that represents a promising therapeutic target due to its tumor suppressor properties regulating the p53-mediated DNA damage and the intracellular localization of the oncogenic YBX1 protein. However, to translate this finding into the clinic as a gene therapy, it is important to develop effective carriers able to deliver exogenous lncRNAs to the targeted cancer cells. Here, we propose the use of biocompatible sphingomyelin nanosystems comprising DOTAP (DSNs) to carry and deliver a plasmid vector encoding for TP53TG1 (pc(TP53TG1)-DSNs) to a colorectal cancer cell line (HCT-116). DSNs presented a high association capacity and convenient physicochemical properties. In addition, pc(TP53TG1)-DSNs showed anti-tumor activities in vitro, specifically a decrease in the proliferation rate, a diminished colony-forming capacity, and hampered migration and invasiveness of the treated cancer cells. Consequently, the proposed strategy displays a high potential as a therapeutic approach for colorectal cancer.

Mucopolysaccharidoses type I gene therapy

Mucopolysaccharidoses type I (MPS I) is an inherited metabolic disease characterized by a malfunction of the α-l-iduronidase (IDUA) enzyme leading to the storage of glycosaminoglycans in the lysosomes. This disease has longtime been studied as a therapeutic target for those studying gene therapy and many studies have been done using various vectors to deliver the IDUA gene for corrective treatment. Many vectors have difficulties with efficacy and insertional mutagenesis concerns including adeno-associated viral (AAV) vectors. Studies of AAV vectors treating MPS I have seemed promising, but recent deaths in gene therapy clinical trials for other inherited diseases using AAV vectors have left questions about their safety. Additionally, the recent modifications to adenoviral vectors leading them to target the vascular endothelium minimizing the risk of hepatotoxicity could lead to them being a viable option for MPS I gene therapy when coupled with gene editing technologies like CRISPR/Cas9.

Anti-aging properties of phytoconstituents and phyto-nanoemulsions and their application in managing aging-related diseases

Aging is spontaneous and inevitable process in all living beings. It is a complex natural phenomenon that manifests as a gradual decline of physiological functions and homeostasis. Aging inevitably leads to age-associated injuries, diseases, and eventually death. The research on aging-associated diseases aimed at delaying, preventing or even reversing the aging process are of great significance for healthy aging and also for scientific progress. Numerous plant-derived compounds have anti-aging effects, but their therapeutic potential is limited due to their short shelf-life and low bioavailability. As the novel delivery system, nanoemulsion can effectively improve this defect. Nanoemulsions enhance the delivery of drugs to the target site, maintain the plasma concentration for a longer period, and minimize adverse reaction and side effects. This review describes the importance of nanoemulsions for the delivery of phyto-derived compounds and highlights the importance of nanoemulsions in the treatment of aging-related diseases. It also covers the methods of preparation, fate and safety of nanoemulsions, which will provide valuable information for the development of new strategies in treatment of aging-related diseases.

Redox-Responsive Gene Delivery from Perfluorocarbon Nanoemulsions through Cleavable Poly(2-oxazoline) Surfactants

The clinical utility of emulsions as delivery vehicles is hindered by a dependence on passive release. Stimuli-responsive emulsions overcome this limitation but rely on external triggers or are composed of nanoparticle-stabilized droplets that preclude sizes necessary for biomedical applications. Here, we employ cleavable poly(2-oxazoline) diblock copolymer surfactants to form perfluorocarbon (PFC) nanoemulsions that release cargo upon exposure to glutathione. These surfactants allow for the first example of redox-responsive nanoemulsions in cellulo. A noncovalent fluorous tagging strategy is leveraged to solubilize a GFP plasmid inside the PFC nanoemulsions, whereupon protein expression is achieved selectively when employing a stimuli-responsive surfactant. This work contributes a methodology for non-viral gene delivery and represents a general approach to nanoemulsions that respond to endogenous stimuli.

Polymeric Nanosystems for Immunogenic Cell Death-Based Cancer Immunotherapy

Immunotherapy has pointed out a scientific and promising direction for cancer treatment through the rouse of immunosurveillance and the decrease of possible side effects in recent years. In immunotherapy, immunogenic cancer cell death (ICD) plays a critical role in regulating anti-cancer immune system in vivo via the release of damage-associated molecular patterns. ICD can not only induce in situ cancer cells apoptosis, but also arouse the immune response against metastatic tumors, which is of great clinical significance to eradicate tumors. In cancer immunotherapy, polymer nanoparticles have drawn increasing attention as an important component of ICD-based immunotherapy attributing to their controllable size, excellent biocompatibility, promising ability of protecting cargo from surrounding environment, which delivers the antigens or immune inducers to antigen-presenting cells, and further triggers sinnvoll T cell response. In this review, the recent advances in the development of polymeric material-based nanosystems for ICD-mediated cancer immunotherapy are summarized. The mechanism of ICD and some current restrictions inhibiting the efficiency of immunotherapy and future prospects are also discussed.

Small interfering RNA (siRNA) to target genes and molecular pathways in glioblastoma therapy: Current status with an emphasis on delivery systems

Glioblastoma multiforme (GBM) is one of the worst brain tumors arising from glial cells, causing many deaths annually. Surgery, chemotherapy, radiotherapy and immunotherapy are used for GBM treatment. However, GBM is still an incurable disease, and new approaches are required for its successful treatment. Because mutations and amplifications occurring in several genes are responsible for the progression and aggressive behavior of GBM cells, genetic approaches are of great importance in its treatment. Small interfering RNA (siRNA) is a new emerging tool to silence the genes responsible for disease progression, particularly cancer. SiRNA can be used for GBM treatment by down-regulating genes such as VEGF, STAT3, ELTD1 or EGFR. Furthermore, the use of siRNA can promote the chemosensitivity of GBM cells. However, the efficiency of siRNA in GBM is limited via its degradation by enzymes, and its off-targeting effects. SiRNA-loaded carriers, especially nanovehicles that are ligand-functionalized by CXCR4 or angiopep-2, can be used for the protection and targeted delivery of siRNA. Nanostructures can provide a platform for co-delivery of siRNA plus anti-tumor drugs as another benefit. The prepared nanovehicles should be stable and biocompatible in order to be tested in human studies.

Micro cell vesicle technology (mCVT): a novel hybrid system of gene delivery for hard-to-transfect (HTT) cells

A hybrid gene delivery platform, micro Cell Vesicle Technology (mCVT), produced from the fusion of plasma membranes and cationic lipids, is presently used to improve the transfection efficiency of hard-to-transfect (HTT) cells. The plasma membrane components of mCVTs impart specificity in cellular uptake and reduce cytotoxicity in the transfection process, while the cationic lipids complex with the genetic material and provide structural integrity to mCVTs.

Cationic Liposome/DNA Complexes Mediate Antitumor Immunotherapy by Promoting Immunogenic Tumor Cell Death and Dendritic Cell Activation

Immunotherapy has been successfully used in the treatment of multiple malignancies, but clinical studies revealed low response rates. Thus, the development of new effective immunotherapeutic modalities is urgently needed. Successfully inducing tumor cell death with enhanced antigenicity is important for the expansion and differentiation of tumor-specific CD8⁺ cytotoxic T lymphocytes. Cationic liposome/DNA complexes (CLN/DNA), which usually have obvious cytotoxic effects, may improve the antitumor immunity through enhancing the immunogenicity of dying tumor cells. Herein, we report that a plasmid DNA-encapsulated cationic lipid nanoparticle formulated with cholesterol, DOTAP, and DSPE-mPEG₂₀₀₀ significantly increases the tumor cell death with high antigenicity in vitro. Furthermore, the cationic liposome/DNA complex (CLN/DNA) treatment promotes the activation of dendritic cells (DCs). We also find that the intratumorally injected CLN/DNA successfully promoted the activation of DCs in the tumor-draining lymph node. Importantly, both local tumor growth and distant tumor formation were significantly inhibited by T cell-dependent antitumor immune responses after intratumoral injection of CLN/DNA. This study presents a simple and effective strategy for improving the cancer immunotherapy.

Molecular insights and novel approaches for targeting tumor metastasis

In recent years, due to the effective drug delivery and preciseness of tumor sites or microenvironment, the targeted drug delivery approaches have gained ample attention for tumor metastasis therapy. The conventional treatment approaches for metastasis therapy have reported with immense adverse effects because they exhibited maximum probability of killing the carcinogenic cells along with healthy cells. The tumor vasculature, comprising of vasculogenic impressions and angiogenesis, greatly depends upon the growth and metastasis in the tumors. Therefore, various nanocarriers-based delivery approaches for targeting to tumor vasculature have been attempted as efficient and potential approaches for the treatment of tumor metastasis and the associated lesions. Furthermore, the targeted drug delivery approaches have found to be most apt way to overcome from all the limitations and adverse effects associated with the conventional therapies. In this review, various approaches for efficient targeting of pharmacologically active chemotherapeutics against tumor metastasis with the cohesive objectives of prognosis, tracking and therapy are summarized.

Sphingomyelin-Based Nanosystems (SNs) for the Development of Anticancer miRNA Therapeutics

Gene replacement therapy with oncosuppressor microRNAs (miRNAs) is a promising alternative to interfere with cancer progression. However, miRNAs are highly inefficient in a biological environment, hampering a successful translation to clinics. Nanotechnology can tackle this drawback by providing delivery systems able to efficiently deliver them to cancer cells. Thus, the objective of this work was to develop biocompatible nanosystems based on sphingomyelin (SM) for the intracellular delivery of miRNAs to colorectal cancer cells. We pursued two different approaches to select the most appropriate composition for miRNA delivery. On the one hand, we prepared sphingomyelin-based nanosystems (SNs) that incorporate the cationic lipid stearylamine (ST) to support the association of miRNA by the establishment of electrostatic interactions (SNs–ST). On the other hand, the cationic surfactant (DOTAP) was used to preform lipidic complexes with miRNA (Lpx), which were further encapsulated into SNs (SNs-Lpx). Restitution of miRNA145 levels after transfection with SNs-Lpx was related to the strongest anticancer effect in terms of tumor proliferation, colony forming, and migration capacity assays. Altogether, our results suggest that SNs have the potential for miRNA delivery to develop innovative anticancer therapies.

Functional ibuprofen-loaded cationic nanoemulsion: Development and optimization for dry eye disease treatment

Inflammation plays a key role in dry eye disease (DED) affecting millions of people worldwide. Non-steroidal anti-inflammatory drugs (NSAIDs) can be used topically to act on the inflammatory component of DED, but their limited aqueous solubility raises formulation issues. The aim of this study was development and optimization of functional cationic nanoemulsions (NEs) for DED treatment, as a formulation approach to circumvent solubility problems, prolong drug residence at the ocular surface and stabilize the tear film. Ibuprofen was employed as the model NSAID, chitosan as the cationic agent, and lecithin as the anionic surfactant enabling chitosan incorporation. Moreover, lecithin is a mixture of phospholipids including phosphatidylcholine and phosphatidylethanolamine, two constituents of the natural tear film important for its stability. NEs were characterized in terms of droplet size, polydispersity index, zeta-potential, pH, viscosity, osmolarity, surface tension, entrapment efficiency, stability, sterilizability and in vitro release. NEs mucoadhesive properties were tested rheologically after mixing with mucin dispersion. Biocompatibility was assessed employing 3D HCE-T cell-based model and ex vivo model using porcine corneas. The results of our study pointed out the NE formulation with 0.05% (w/w) chitosan as the lead formulation with physicochemical properties adequate for ophthalmic application, mucoadhesive character and excellent biocompatibility.

Cationic Surfactants: Self-Assembly, Structure-Activity Correlation and Their Biological Applications

The development of biotechnological protocols based on cationic surfactants is a modern trend focusing on the fabrication of antimicrobial and bioimaging agents, supramolecular catalysts, stabilizers of nanoparticles, and especially drug and gene nanocarriers. The main emphasis given to the design of novel ecologically friendly and biocompatible cationic surfactants makes it possible to avoid the drawbacks of nanoformulations preventing their entry to clinical trials. To solve the problem of toxicity various ways are proposed, including the use of mixed composition with nontoxic nonionic surfactants and/or hydrotropic agents, design of amphiphilic compounds bearing natural or cleavable fragments. Essential advantages of cationic surfactants are the structural diversity of their head groups allowing of chemical modification and introduction of desirable moiety to answer the green chemistry criteria. The latter can be exemplified by the design of novel families of ecological friendly cleavable surfactants, with improved biodegradability, amphiphiles with natural fragments, and geminis with low aggregation threshold. Importantly, the development of amphiphilic nanocarriers for drug delivery allows understanding the correlation between the chemical structure of surfactants, their aggregation behavior, and their functional activity. This review focuses on several aspects related to the synthesis of innovative cationic surfactants and their broad biological applications including antimicrobial activity, solubilization of hydrophobic drugs, complexation with DNA, and catalytic effect toward important biochemical reaction.

Biodegradable Polymers for Gene Delivery

The cellular transport process of DNA is hampered by cell membrane barriers, and hence, a delivery vehicle is essential for realizing the potential benefits of gene therapy to combat a variety of genetic diseases. Virus-based vehicles are effective, although immunogenicity, toxicity and cancer formation are among the major limitations of this approach. Cationic polymers, such as polyethyleneimine are capable of condensing DNA to nanoparticles and facilitate gene delivery. Lack of biodegradation of polymeric gene delivery vehicles poses significant toxicity because of the accumulation of polymers in the tissue. Many attempts have been made to develop biodegradable polymers for gene delivery by modifying existing polymers and/or using natural biodegradable polymers. This review summarizes mechanistic aspects of gene delivery and the development of biodegradable polymers for gene delivery.

Cationic Niosomes as Non-Viral Vehicles for Nucleic Acids: Challenges and Opportunities in Gene Delivery

Cationic niosomes have become important non-viral vehicles for transporting a good number of small drug molecules and macromolecules. Growing interest shown by these colloidal nanoparticles in therapy is determined by their structural similarities to liposomes. Cationic niosomes are usually obtained from the self-assembly of non-ionic surfactant molecules. This process can be governed not only by the nature of such surfactants but also by others factors like the presence of additives, formulation preparation and properties of the encapsulated hydrophobic or hydrophilic molecules. This review is aimed at providing recent information for using cationic niosomes for gene delivery purposes with particular emphasis on improving the transportation of antisense oligonucleotides (ASOs), small interference RNAs (siRNAs), aptamers and plasmids (pDNA).

Gene Therapy

Gene therapy medicinal products (GTMPs) are one of the most promising biopharmaceuticals, which are beginning to show encouraging results. The broad clinical research activity has been addressed mainly to cancer, primarily to those cancers that do not respond well to conventional treatment. GTMPs to treat rare disorders caused by single-gene mutations have also made important advancements toward market availability, with eye and hematopoietic system diseases as the main applications.Nucleic acid-marketed products are based on both in vivo and ex vivo strategies. Apart from DNA-based therapies, antisense oligonucleotides, small interfering RNA, and, recently, T-cell-based therapies have been also marketed. Moreover, the gene-editing tool CRISPR is boosting the development of new gene therapy-based medicines, and it is expected to have a substantial impact on the gene therapy biopharmaceutical market in the near future.However, despite the important advancements of gene therapy, many challenges have still to be overcome, which are discussed in this book chapter. Issues such as efficacy and safety of the gene delivery systems and manufacturing capacity of biotechnological companies to produce viral vectors are usually considered, but problems related to cost and patient affordability must be also faced to ensure the success of this emerging therapy. Graphical Abstract.

Nanoemulsions of sulfonamide carbonic anhydrase inhibitors strongly inhibit the growth of Trypanosoma cruzi

Sulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitors targeting the α-class enzyme from the protozoan pathogen Trypanosoma cruzi, responsible of Chagas disease, were recently reported. Although many such derivatives showed low nanomolar activity in vitro, they were inefficient anti-T. cruzi agents in vivo. Here, we show that by formulating such sulfonamides as nanoemulsions in clove (Eugenia caryophyllus) oil, highly efficient anti-protozoan effects are observed against two different strains of T. cruzi. These effects are probably due to an enhanced permeation of the enzyme inhibitor through the nanoemulsion formulation, interfering in this way with the life cycle of the pathogen either by inhibiting pH regulation or carboxylating reactions in which bicarbonate/CO2 are involved. This type of formulation of sulfonamides with T. cruzi CA inhibitory effects may lead to novel therapeutic approaches against this orphan disease.

Box Behnken design of siRNA-loaded liposomes for the treatment of a murine model of ocular keratitis caused by Acanthamoeba

Acanthamoeba keratitis is an ophthalmic disease with no specific treatment that specially affects contact lens users. The silencing of serine phosphatase (SP) and glycogen phosphorylase (GP) proteins produced by Acanthamoeba has been shown to significantly reduce the cytopathic effect, although no vehicle was proposed yet to deliver the siRNA sequences to the trophozoites. In this study, PEGylated cationic liposomes were proposed and optimized using Box-Behnken design. The influence of DOTAP:DOPE ratio, DSPE-PEG concentration, and siRNA/DOTAP charge ratio were evaluated over both biological response and physicochemical properties of liposomes. The ratio of DOTAP:DOPE had an effect in the trophozoite activity whereas the charge ratio influenced both size and protease activity. The predicted values were very close to the observed values, yielding a formulation with good activity and toxicity profile, which was used in the following experiments. A murine model of ocular keratitis was treated with siGP + siSP-loaded liposomes, as well as their respective controls, and combined treatment of liposomes and chlorhexidine. After 15 days of eight daily administrations, the liposomal complex combined with chlorhexidine was the only treatment able to reverse the more severe lesions associated with keratitis. There was 60% complete regression in corneal damage, with histological sections demonstrating the presence of an integral epithelium, without lymphocytic infiltrate. The set of results demonstrate the efficacy of a combined therapy based on siRNA with classical drugs for a better prognosis of keratitis caused by Acanthamoeba.

Nasal Administration of Cationic Nanoemulsions as Nucleic Acids Delivery Systems Aiming at Mucopolysaccharidosis Type I Gene Therapy

PURPOSE

This study demonstrates the nasal administration (NA) of nanoemulsions complexed with the plasmid encoding for IDUA protein (pIDUA) as an attempt to reach the brain aiming at MPS I gene therapy.

METHODS

Formulations composed of DOPE, DOTAP, MCT (NE), and DSPE-PEG (NE-PEG) were prepared by high-pressure homogenization, and assessed in vitro on human fibroblasts from MPS I patients and in vivo on MPS I mice for IDUA production and gene expression.

RESULTS

The physicochemical results showed that the presence of DSPE-PEG in the formulations led to smaller and more stable droplets even when submitted to dilution in simulated nasal medium (SNM). In vitro assays showed that pIDUA/NE-PEG complexes were internalized by cells, and led to a 5% significant increase in IDUA activity, besides promoting a two-fold increase in IDUA expression. The NA of pIDUA/NE-PEG complexes to MPS I mice demonstrated the ability to reach the brain, promoting increased IDUA activity and expression in this tissue, as well as in kidney and spleen tissues after treatment. An increase in serum IL-6 was observed after treatment, although with no signs of tissue inflammatory infiltrate according to histopathology and CD68 assessments.

CONCLUSIONS

These findings demonstrated that pIDUA/NE-PEG complexes could efficiently increase IDUA activity in vitro and in vivo after NA, and represent a potential treatment for the neurological impairment present in MPS I patients.