Design and development of polymers for gene delivery

Investigation of the protein corona and biodistribution profile of polymeric nanoparticles for intra-amniotic delivery

When exposed to the biological environment, nanoparticles (NPs) form a protein corona that influences delivery profile. We present a study of protein corona formation and NP biodistribution in amniotic fluid (AF) for poly(lactic-co-glycolic acid) (PLGA) and poly(lactic-acid) (PLA) NPs, with and without polyethylene glycol (PEG), as well as poly(amine-co-ester)-PEG (PACE-PEG) NPs. The presence of surface PEG and polyvinyl alcohol (PVA) were characterized to investigate surfactant role in determining protein corona formation. The surface density of PEG groups demonstrated an inverse correlation with the total amount of protein surface adsorption. All PEGylated NPs exhibited a dense brush conformation and demonstrated higher levels of stability in AF than non-PEGylated NPs. The protein corona composition varied by core polymer, while the amount of protein adsorption varied by PEGylation status. In A549 cells, in vitro cellular association of each NP type correlated with the amount of albumin that was found in the protein corona. In vivo, only PEGylated NPs were able successfully distribute to fetal organs, likely due to the enhanced stability imparted by PEG. PLGA-PEG and PACE-PEG NPs had both high levels of albumin in the protein corona and high biodistribution to the fetal lung, consistent with the association with lung cells in vitro. PLA-PEG NPs distributed exclusively to the fetal bowel, which we propose is associated with known gastrointestinal targeting keratin proteins. By furthering our understanding of polymeric NP behavior in AF, this novel study provides a basis for optimization of intra-amniotic NP delivery systems targeting congenital pulmonary and gastrointestinal diseases.

A novel FTO-targeting nanodrug induces disulfidptosis and ameliorates the suppressive tumor immune environment to treat uveal melanoma

Uveal melanoma (UM) is the most prevalent primary ocular malignancy in adults, with high lethality and limited effective treatment options. Despite identified driver mutations in GNAQ, GNA11, and BAP1, therapeutic advancements have been minimal. This study highlights the pivotal role of N6-methyladenosine (m6A) modifications in UM pathogenesis and progression, focusing on the demethylase FTO as a therapeutic target. Elevated FTO expression in UM tissues correlates with decreased m6A levels, increased aggressiveness, and poor prognosis. The FTO inhibitor meclofenamic acid (MA) restored m6A levels, upregulated SLC7A11, and induced disulfidptosis, a unique form of cell death triggered by GSH depletion and NADPH consumption. To address MA's limitations in bioavailability and tumor targeting, we developed an MA-loaded nucleic acid nanodrug (SNAMA). SNAMA demonstrated effective tumor growth inhibition in orthotopic and metastatic UM models through GSH-responsive release and m6A-mediated disulfidptosis activation. Incorporating a PD-L1 aptamer into SNAMA further improved tumor targeting and immune modulation, enhancing therapeutic efficacy. This study identifies FTO as a critical target for UM therapy and introduces SNAMA-apt as a promising nanodrug. The findings offer a foundation for m6A-targeted approaches in UM and other malignancies, addressing bioavailability, targeting, and immune evasion challenges.

Thiol- and Disulfide-Functionalized Polycyclooctene: Metathesis Polymerization, Degradation, and Reformation

The enormous global production and use of polymers and plastics, combined with slower and less efficient disposal and recycling methods, have led to a worldwide growth in plastic waste. Here, we describe an approach that builds degradability into macromolecular polyolefins through the design of telechelic oligomers with reactive functional groups that enables control over polymer deconstruction and reconstruction. Our work exploits disulfide-containing polymers that have emerged as promising cyclable materials due to their dynamic reversibility (bond formation and cleavage) driven by redox chemistry under mild conditions. Specifically, we describe the synthesis of a telechelic α,ω-dithiopolycyclooctene (PCOE) by ring-opening metathesis polymerization using a dithioacetate chain transfer agent, followed by deprotection to convert the chain-end thioacetates to thiols. This process was studied towards control over the degree of oxidation to yield disulfide-containing PCOE, followed by an evaluation of reductive degradation and oxidative repolymerization. Overall, this approach facilitates the production of disulfide-containing unsaturated polyolefins and the integration of degradable and reformable moieties into soluble, processable, metathesis-derived polymers.

MicroRNA nanoformulation: a promising approach to anti-tumour activity

Cancer is a major cause of morbidity and mortality, making it one of the most debilitating diseases in our time. Despite advancements in therapeutic strategies, the development of chemoresistance and the occurrence of secondary tumours pose significant challenges. While several promising anti-tumour agents have been identified, their clinical utility is often limited due to toxicity and associated side effects. MicroRNAs (mi-RNAs) are critical regulators of gene expression, and their altered levels are closely linked to cancer development and progression. Although some microRNAs have shown potential as biomarkers for cancer detection, their integration into routine clinical practice has yet to be realized. Numerous candidate microRNAs exhibit therapeutic potential for cancer treatment; however, further research is needed to create efficient, patient-compliant, and customized drug delivery systems. In recent decades, various nanotechnology platforms have successfully transitioned to clinical trials, particularly in the field of RNA nanotechnology. Several RNA nanoparticles have been developed to address key challenges in vivo for targeting cancer, demonstrating favourable biodistribution characteristics. Studies have shown that RNA nanoparticles, characterized by precise stoichiometry and homogeneity, can effectively target tumour cells while avoiding aggregation in normal, healthy tissues following systemic injection. Animal models have demonstrated that RNA nanoparticles can deliver therapeutics such as siRNA and anti-microRNA, effectively inhibiting tumour growth. Using nanoparticles conjugated with antibodies and/or peptides enhances the targeted delivery and sustained release of microRNAs and anti-microRNAs, which may reduce the required therapeutic dosage and minimize systemic and cellular damage. This review focuses on developing microRNA nanoformulations to improve cellular uptake, bioavailability, and accumulation at tumour sites, assessing their potential anti-tumour efficacy against various types of malignancies. The significance of these advancements in clinical oncology cannot be overstated.

Combination therapy and drug co-delivery systems for atherosclerosis

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of plaque within the arteries. Despite advances in therapeutic strategies including anti-inflammatory, antioxidant, and lipid metabolism modulation treatments over the past two decades, the treatment of atherosclerosis remains challenging, as arterial damage is the result of interconnected pathological factors. Therefore, current monotherapies often fail to address the complex nature of this disease, leading to insufficient therapeutic outcomes. This review addressed this paucity of effective treatment options by comprehensively exploring the potential for combination therapies and advanced drug co-delivery systems for the treatment of atherosclerosis. We investigated the pathological features of and risk factors for atherosclerosis, underscoring the importance of drug combination therapies for the treatment of atherosclerotic diseases. We discuss herein mathematical models for quantifying the efficacy of the combination therapies and provide a systematic summary of drug combinations for the treatment of atherosclerosis. We also provide a detailed review of the latest advances in nanoparticle-based drug co-delivery systems for the treatment of atherosclerosis, focusing on the design of carriers with high biocompatibility and efficacy. By exploring the possibilities and challenges inherent to this approach, we aim to highlight cutting-edge technologies that can foster the development of innovative strategies, optimize drug co-administration, improve treatment outcomes, and reduce the burden of atherosclerosis-related morbidity and mortality on the healthcare system.

Preparation of thermoresponsive core-corona particles for controlled phagocytosis via surface properties and particle shape transformation

Cell-particle interactions, such as phagocytosis, exhibit variability based on particle shape, surface physical properties, and diameter. These interactions can be intentionally modified through in situ change in the physical characteristics of the particulate materials. By manipulating both the surface properties and shape of the particles, it may be feasible to regulate their interactions with cells. Objective of this research is to prepare thermoresponsive core-corona particles those undergo transformation and alteration in surface solubility near physiological temperature and to investigate particle shape- and surface physical property-dependent phagocytosis. The glass transition temperature of the prepared particles was controlled via the composition of the polymer core. Rod-type particles, prepared by uniaxially stretching particle-containing films at above the glass transition temperature of the core-forming materials, demonstrated reduced phagocytosis by macrophages compared to that of spherical particles. Furthermore, the physical properties of the particle surface exerted a significant influence on phagocytosis, with hydrophobic particles being more readily engulfed. Consequently, precise control of phagocytosis can be controlled by manipulating the particle's shape and surface properties. The prepared particles have potential applications as drug delivery system carriers, enabling the regulation of cell interactions via particle shape and surface physical properties induced by temperature changes.

Impact of pre-existing anti-polyethylene glycol (PEG) IgM on biodistribution and humoral response of intramuscularly administered PEGylated mRNA loaded lipid nanoparticle

With the approval of mRNA vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), lipid nanoparticles (LNP) have emerged as a powerful tool for nucleic acid delivery. Modification of LNP with polyethylene glycol (PEG)-lipids contributes to their in vitro and in vivo stability by reducing aggregation of the particles. Despite the general acknowledgement of the low immunogenicity of PEG, there are numerous reports of the occurrence of anti-PEG antibodies in the blood of healthy individuals. Furthermore, there are reports that pre-existing anti-PEG IgM antibodies attenuated the efficacy of PEG-modified drugs administered systemically. Skeletal muscles, the administration site for mRNA vaccines, are highly vascularized by a network of blood vessels to provide them with nutrients and oxygen. Since skeletal muscles can contain circulating anti-PEG antibodies or the administered mRNA-LNP extravasate into bloodstream, the purpose of this study was to evaluate the effects of pre-existing anti-PEG IgM on the protein translation, biodistribution, and humoral responses to mRNA-loaded LNP (mRNA-LNP) administered intramuscularly (i.m.) in mice. We found that the presence of anti-PEG IgM in blood has only a minor effect on the translation and distribution of mRNA-LNP in the localized muscle area where the mRNA-LNP were administered. Circulating anti-PEG IgM did not increase the total accumulation of mRNA-LNP in the liver, but did markedly diminish its protein translation because the mRNA-LNP were delivered primarily to Kupffer cells rather than to hepatocytes. Binding of anti-PEG IgM to mRNA-LNP, and subsequent complement activation, suppressed mRNA translation loaded in LNP in the liver. Repeated intramuscular injections of SARS-CoV-2 Spike protein mRNA-LNP elicited a robust immune response. Our results indicate that the presence of circulating anti-PEG IgM does not interfere with the efficiency of mRNA vaccines administered i.m. in mice. We can speculate that non-specific translation of mRNA vaccines in somatic cells may be inhibited in vivo by circulating anti-PEG IgM, reducing adverse effects such as hepatitis and myocarditis that are caused by immune responses against translated antigen proteins.

From genetic code to global health: the impact of nucleic acid vaccines on disease prevention and treatment

Vaccinology has revolutionized modern medicine, delivering groundbreaking solutions to prevent and control infectious diseases while pioneering innovative strategies to tackle non-infectious challenges, including cancer. Traditional vaccines faced inherent limitations, driving the evolution of next-generation vaccines such as subunit vaccines, peptide-based vaccines, and nucleic acid-based platforms. Among these, nucleic acid-based vaccines, including DNA and mRNA technologies, represent a major innovation. Pioneering studies in the 1990s demonstrated their ability to elicit immune responses by encoding specific antigens. Recent advancements in delivery systems and molecular engineering have overcome initial challenges, enabling their rapid development and clinical success. This review explores nucleic acid-based vaccines, including chemically modified variants, by examining their mechanisms, structural features, and therapeutic potential, while underscoring their pivotal role in modern immunization strategies and expanding applications across contemporary medicine.

Tobramycin crosslinking improves the colloidal stability of arginine chitosan biodynamers for safe and efficient siRNA delivery

We previously reported proteoid biodynamers to form dynamic nanocomplexes (dynaplexes, DPs) with siRNA and their efficient transfection via dynamic responsive changes in endosomal environments. However, their limited colloidal stability requires chemical crosslinking, which may cause toxicity. To address these limitations, we designed biodynamers using positively charged aldehyde chitosan (ACh) as the backbone, which was functionalized with arginine hydrazide (Arg) and/or tobramycin (Tob) to create either Arg-ACh, Tob-ACh or Arg/Tob-ACh, respectively. While the additional positive charges introduced by Arg improved the siRNA complexation, the multiple amine groups in Tob acted as internal crosslinkers. Additionally, the resulting siRNA-loaded DPs were coated with hyaluronic acid (HA), which further enhanced colloidal stability. Compared to proteoid biodynamers, these novel functionalized chitosan biodynamers provided adequate gene silencing efficiency without the need for potentially harmful additional crosslinkers.

Enhancing immunotherapy with tumour-responsive nanomaterials

The targeted delivery of immunotherapies to tumours using tumour-responsive nanomaterials is a promising area of cancer research with the potential to address the limitations of systemic administration such as on-target off-tumour toxicities and a lack of activity owing to the immunosuppressive tumour microenvironment (TME). Attempts to address these challenges include the design and functionalization of nanomaterials capable of releasing their cargoes in response to specific TME characteristics, thus facilitating the targeted delivery of immune-checkpoint inhibitors, cytokines, mRNAs, vaccines and, potentially, chimaeric antigen receptors as well as of agents that modulate the extracellular matrix and induce immunogenic cell death. In this Review, we describe these various research efforts in the context of the dynamic properties of the TME, such as pH, reductive conditions, reactive oxygen species, hypoxia, specific enzymes, high levels of ATP and locoregional aspects, which can be leveraged to enhance the specificity and efficacy of nanomaterial-based immunotherapies. Highlighting preclinical successes and ongoing clinical trials, we evaluate the current landscape and potential of these innovative approaches. We also consider future research directions as well as the most important barriers to successful clinical translation, emphasizing the transformative potential of tumour-responsive nanomaterials in overcoming the barriers that limit the activity of traditional immunotherapies, thus improving patient outcomes.

CBX2 as a therapeutic target in colorectal cancer: insights into the altered chromatin accessibility via RUNX1-CBX2-MAP4K1 axis

Chromobox homolog 2 (CBX2), a component of the polycomb repressive complex 1, is overexpressed in various cancers, but its specific role in colorectal cancer (CRC) is not fully understood. This study aimed to characterize the functional and regulatory roles of CBX2 in CRC. Tissue microarray analysis revealed the elevated CBX2 levels in tumor compared to adjacent normal tissues, which is significantly correlated with poor prognosis. Gain and loss of function studies demonstrated that CBX2 significantly promoted CRC progression and chemoresistance in cell lines, patient-derived CRC organoids and xenografts. In the AOM/DSS mouse model, treatment with the innovatively-developed cy5-PBAE/siCBX2 nanoparticle significantly reduced tumor aggressiveness. Mechanistic studies unveiled that the transcription factor RUNX1 is the positive regulator of CBX2. RNA-seq, ATAC-seq and CUT & RUN results indicated CBX2 knockdown induced epigenetic changes, especially alterations in chromatin accessibility. Moreover, we further identified MAP4K1 as a target gene of RUNX1-CBX2, with significant clinical and prognostic relevance in CRC. Collectively, these findings suggest the pivotal role of RUNX1-CBX2-MAP4K1 axis in CRC progression and underscore CBX2 as a promising biomarker and therapeutic target. The regulatory function of CBX2 on chromatin accessibility and the role of the RUNX1-CBX2-MAP4K1-pERK axis in the progression of colorectal cancer.

Endocytic highways: Navigating macropinocytosis and other endocytic routes for precision drug delivery

Drug molecules can reach intracellular targets by different mechanisms, such as passive diffusion, active transport, and endocytosis. Endocytosis is the process by which cells engulf extracellular material by forming a vesicle and transporting it into the cells. In addition to its biological functions, endocytosis plays a vital role in the internalization of the therapeutic molecules. Clathrin-mediated endocytosis, caveolar endocytosis, and macropinocytosis are the most researched routes in the field of drug delivery. In addition to conventional small therapeutic molecules, the use of nanoformulations and large molecules, such as nucleic acids, peptides, and antibodies, have broadened the field of drug delivery. Although the majority of small therapeutic molecules can enter cells via passive diffusion, large molecules, and advanced targeted delivery systems, such as nanoparticles, are internalized by the endocytic route. Therefore, it is imperative to understand the characteristics of the endocytic routes in greater detail to design therapeutic molecules or formulations for successful delivery to the intracellular targets. This review highlights the prospects and limitations of the major endocytic routes for drug delivery, with a major emphasis on macropinocytosis. Since macropinocytosis is a non-selective uptake of extracellular matrix, the selective induction of macropinocytosis, using compounds that induce macropinocytosis and modulate macropinosome trafficking pathways, could be a potential approach for the intracellular delivery of diverse therapeutic modalities. Furthermore, we have summarized the characteristics associated with the formulations or drug carriers that can affect the endocytic routes for cellular internalization. The techniques that are used to study the intracellular uptake processes of therapeutic molecules are briefly discussed. Finally, the major limitations for intracellular targeting, endo-lysosomal degradation, and different approaches that have been used in overcoming these limitations, are highlighted in this review.

Cell-Division-Independent Rapid Expression of DNA Delivered with α-Synuclein-Gold Nanoparticle Conjugates

Gene delivery is a primary technology employed in diverse areas of biomedical science, from gene therapy to gene editing, cancer treatment, and stem cell research. Here, we introduce a gene delivery system utilizing an intrinsically disordered protein of α-synuclein (αS) demonstrated to interact with lipid membranes by transforming its original random structure to an α-helix. Since the helix bundle formation is a signature of cell-penetrating peptides for membrane translocation, a multitude of αS(Y136C)s replacing tyrosine at the C-terminus with cysteine were covalently attached onto gold nanoparticles (AuNPs) in a specific orientation with the helix-forming basic N-termini exposed outward. The resulting αS(Y136C)-AuNP conjugates were found to exhibit a rapid gene expression without causing cytotoxicity when the gene of the enhanced green fluorescent protein (EGFP) was delivered with the conjugates into the cells. Based on inhibition studies toward endocytosis and mitosis, the αS(Y136C)-AuNP/DNA complex was demonstrated to take both endosomal and non-endosomal intracellular transport pathways. The DNA translocation into the nucleus was independent of cell division. This nondisruptive and rapid DNA transfection by αS(Y136C)-AuNPs allowed a successful delivery of granzyme A gene leading to cellular pyroptosis. Modifications of αS(Y136C)-AuNP/DNA complex, such as antibody immobilization and replacement of DNA with biological suprastructures including RNA, protein, and nonbiological fusion materials, would allow the intracellular delivery system to be applied in diverse areas of future biotechnology.

Mesenchymal stromal cells surface engineering for efficient hematopoietic reconstitution

Mesenchymal stromal cells (MSCs) are believed to migrate to injury sites, release chemical attractants, and either recruit local stem cells or modulate the immune system positively. Although MSCs are highly desired for their potential to reduce inflammation and promote tissue regeneration, their limited lifespan restricts their applications. This study presents a simple approach for protecting MSCs with epigallocatechin-3-gallate (EGCG) and magnesium (Mg) based metal-organic framework coatings (E-Mg@MSC). The layer strengthens MSCs resistant to harmful stresses and creates a favorable microenvironment for repair by providing Mg to facilitate MSCs' osteogenic differentiation and using EGCG to neutralize excessive reactive oxygen species (ROS). E-Mg@MSC serves as a treatment for hematopoietic injury induced by ionizing radiation (IR). Coated MSCs exhibit sustained secretion of hematopoietic growth factors and precise homing to radiation-sensitive tissues. In vivo studies show substantial enhancement in hematopoietic system recovery and multi-organ protection. Mechanistic investigations suggest that E-Mg@MSC mitigates IR-induced ROS, cell apoptosis, and ferroptosis, contributing to reduced radiation damage. The system represents a versatile and compelling strategy for cell-surface engineering with functional materials to advance MSCs therapy.

Applications of Gene Editing and Nanotechnology in Stem Cell-Based Therapies for Human Diseases

Stem cell research is a dynamic and fast-advancing discipline with great promise for the treatment of diverse human disorders. The incorporation of gene editing technologies, including ZFNs, TALENs, and the CRISPR/Cas system, in conjunction with progress in nanotechnology, is fundamentally transforming stem cell therapy and research. These innovations not only provide a glimmer of optimism for patients and healthcare practitioners but also possess the capacity to radically reshape medical treatment paradigms. Gene editing and nanotechnology synergistically enhance stem cell-based therapies' precision, efficiency, and applicability, offering transformative potential for treating complex diseases and advancing regenerative medicine. Nevertheless, it is important to acknowledge that these technologies also give rise to ethical considerations and possible hazards, such as inadvertent genetic modifications and the development of genetically modified organisms, therefore creating a new age of designer infants. This review emphasizes the crucial significance of gene editing technologies and nanotechnology in the progress of stem cell treatments, particularly for degenerative pathologies and injuries. It emphasizes their capacity to restructure and comprehensively revolutionize medical treatment paradigms, providing fresh hope and optimism for patients and healthcare practitioners.

A pH-Responsive and Guanidinium-Rich Nanoadjuvant Efficiently Delivers STING Agonist for Cancer Immunotherapy

As natural agonists of the stimulator of interferon genes (STING), cyclic dinucleotides (CDNs) have been identified as promising immunotherapies that trigger a potent immune response against tumors. However, the low stability, rapid clearance, inadequate cellular uptake, and inefficient cytosol localization heavily hinder the therapeutic efficacy of the hydrophilic and negatively charged 2', 3'-cyclic-GMP-AMP (cGAMP). How to efficiently deliver cGAMP into the endoplasmic reticulum (ER) to activate STING for immune priming remains challenging. Here, we report a pH-responsive and guanidinium-rich STING nanoagonist (nPGSA) for cytosol delivery of cGAMP. Compared with free cGAMP, nPGSA achieves up to a 37.4-fold enhancement of cellular internalization. The pH-sensitive and guanidinium-functional design facilitates quick release and endosome escape, thus enabling precise ER targeting of cGAMP and 33.9-fold amplification of STING sensibilization. Furthermore, through the modulation of tumor-associated macrophage (TAM) polarization, nPGSA elicits a potent antigen-specific cellular immune response and sustained tumor regression in melanoma- and neuroblastoma-bearing mice. Our study provides a promising strategy for the delivery of cGAMP, and it offers insights into the function of cGAMP in modulating the tumor immune microenvironment for cancer immunotherapy.

Structurally programmable, functionally tuneable dendrimers in biomedical applications

The application of nanotechnology in medical biology has seen a significant rise in recent years because of the introduction of novel tools that include supramolecular systems, complexes, and composites. Dendrimers are one of the remarkable examples of such tools. These spherical, regularly branching structures with enhanced cell compatibility and bioavailability have shown to be an excellent option for gene or drug administration. They are the fourth important architectural group of polymers after the three well-known types (branched, cross-linked, and linear polymers). These tiny macromolecules generate nanometer-size structures consisting of branching, with identical units assembled around a central core. By regulating dendrimer synthesis, it is possible to manipulate both their molecular weight and chemical content carefully, permitting predictable tailoring of their biocompatibility and pharmacokinetics, making them a promising candidate for biomedical uses. In contrast to their more easily obtainable synthetic techniques and comparable functions in hyperbranched polymers, dendrimers have demonstrated efficacy in biological applications, exhibiting remarkable sample purity and synthesizing reproducibility. Dendrimers are appealing as basic materials for manufacturing nanomaterials for uses in many different disciplines because of their highly specified chemical structure and globular form. Thus, much effort has been made to create functional materials with dendrimers. Especially looking at dendrimer-based nanomaterials meant for use in the biomedical domain, this review discusses the design, types, properties, and function of bionanomaterials employing several techniques, including surface modification, assembly, and hybrid development, and their uses.

Covalent Polymer-RNA Conjugates for Potent Activation of the RIG-I Pathway

RNA ligands of retinoic acid-inducible gene I (RIG-I) are a promising class of oligonucleotide therapeutics with broad potential as antiviral agents, vaccine adjuvants, and cancer immunotherapies. However, their translation has been limited by major drug delivery barriers, including poor cellular uptake, nuclease degradation, and an inability to access the cytosol where RIG-I is localized. Here this challenge is addressed by engineering nanoparticles that harness covalent conjugation of 5'-triphospate RNA (3pRNA) to endosome-destabilizing polymers. Compared to 3pRNA loaded into analogous nanoparticles via electrostatic interactions, it is found that covalent conjugation of 3pRNA improves loading efficiency, enhances immunostimulatory activity, protects against nuclease degradation, and improves serum stability. Additionally, it is found that 3pRNA could be conjugated via either a disulfide or thioether linkage, but that the latter is only permissible if conjugated distal to the 5'-triphosphate group. Finally, administration of 3pRNA-polymer conjugates to mice significantly increases type-I interferon levels relative to analogous carriers that use electrostatic 3pRNA loading. Collectively, these studies have yielded a next-generation polymeric carrier for in vivo delivery of 3pRNA, while also elucidating new chemical design principles for covalent conjugation of 3pRNA with potential to inform the further development of therapeutics and delivery technologies for pharmacological activation of RIG-I.

Nanocarrier-Mediated RNA Delivery Platform as a Frontier Strategy for Hepatic Disease Treatment: Challenges and Opportunities

Hepatic diseases cause serious public health problems worldwide, and there is an urgent need to develop effective therapeutic agents. In recent years, significant progress is made in RNA therapy, and RNA molecules, such as mRNAs, siRNAs, miRNAs, and RNA aptamers, are shown to provide significant advantages in the treatment of hepatic diseases. However, the drawbacks of RNAs, such as their poor biological stability, easy degradation by nucleases in vivo, low bioavailability, and low concentrations in target tissues, significantly limit the clinical application of RNA-based drugs. Therefore, exploring and developing effective nanoscale delivery platforms for RNA therapeutics are of immense value. This review focuses on the different types of hepatic diseases and RNA therapeutics, summarizing various nanoscale delivery platforms and their strengths and weaknesses. Finally, the current status and future prospects of nanoscale delivery systems for RNA therapy are discussed.

Stipulations of cell and gene therapy and the ties to biomanufacturing

Cell and gene therapy (CGT) products are emerging and innovative biopharmaceuticals that hold promise for treating diseases that are otherwise beyond the scope of conventional medicines. The evolution of CGT from a research idea to a promising therapeutic product is due to the complementary advancements across various scientific disciplines. First, the innovations and advancements in gene editing and delivery technology have provided fundamental tools to manipulate genes and cells for therapeutic pursuits. Second, advancements in applied and translational research, including how clinical trials are designed, performed, evaluated, and analyzed, have transformed the technology into a potential therapeutic product. Third, advancements in scaling up the production of CGT products have been critical in delivering the product for preclinical studies, clinical trials, and approved treatments. In parallel, regulatory requirements have continuously evolved, with lessons learned from translational studies and biomanufacturing. These combined efforts have transformed CGT products from a promising concept into a reality with the potential to treat a wide range of diseases. However, continued R&D and regulatory oversight are crucial to further improve the safety, efficacy, and accessibility of CGT products.

Lysosomal activity in response to the incubation of pristine and functionalized carbon nanodots

We present functional studies of lysosomes in human cells after uptake of carbon nanodots (CNDs). Even under high CND concentrations, the lysosomal functionality, as characterized via cathepsins B and L as well as the autophagic markers SQSTM1/p62 and LC3B-II, is maintained. Furthermore, branched polyethylenimine (bPEI) molecules have been coupled to the CNDs as a model functionalization or example of a drug. We observe that the bPEI-CND conjugates accumulate to a higher degree in the lysosomes as compared to bPEI or CND alone. Here, changes in the lysosomal size and function are observed, which can be explained exclusively by the bPEI. It is concluded that CNDs are highly efficient and inert carriers for functional molecules into lysosomes as target, with the added value that lysosomal escape is suppressed, thereby avoiding unintended side effects in other cellular compartments.

Microfluidic Synthesis of miR-200c-3p Lipid Nanoparticles: Targeting ZEB2 to Alleviate Chondrocyte Damage in Osteoarthritis

Introduction

Osteoarthritis (OA) is a degenerative joint disease characterized by articular cartilage degeneration. Chondrocyte inflammation, apoptosis, and extracellular matrix degradation accelerated OA progression. MicroRNA (miRNA) has the potential to be a therapeutic method for osteoarthritis. However, it is difficult to penetrate the cell to exercise its biological function, and its extracellular effect is unclear.

Methods

lipo-AgPEI-miR-200c-3p was created by combining miR-200c-3p with silver nitrate polyvinylimine nanoparticles on a microfluidic device. The drug release curve, stability, temperature sensitivity, cytotoxicity, and the impact of lipo-AgPEI-miR-200c-3p on the expression of proteins linked to matrix disintegration, apoptosis, and inflammatory factors were all detected.

Results

Results showed that the particle size of Lipo-AgPEI-miR-200c-3p was about 130 nm, the Zeta potential was lowered to 1.08±0.12 mV. Lipo-AgPEI-miR-200c-3p could increase cell viability, prevent cell apoptosis, and decrease the expression levels of TNF-α, IL-6, IL-1β, and MCP-1 in ADTC5 cells following LPS stimulation. MMP3, MMP13, and ADAMTS-4 expression was downregulated whereas collagen II expression was upregulated. The ZEB2 expression was greatly elevated following LPS stimulation and dramatically decreased following transfection of miR-200c-3p. Collagen II expression rose following transfection of si-ZEB2, whereas the expression levels of inflammatory factors, apoptosis-related proteins, MMP3, MMP13, and ADAMTS-4 decreased. The dual luciferase experiment demonstrated that ZEB2 was the target gene of miR-200c-3p.

Conclusion

The synergistic effect of AgPEI and miR-200c-3p can inhibit the inflammatory response, apoptosis, and matrix degradation of chondrocytes. Lipo-AgPEI-miR-200c-3p can also improve transfection efficiency and obtain good physicochemical properties of drugs. miR-200c-3p may be crucial in the development of OA and can influence the target gene ZEB2, control the inflammatory response, apoptosis, and chondrocyte matrix breakdown.

DNA vaccines as promising immuno-therapeutics against cancer: a new insight

Cancer is one of the leading causes of mortality around the world and most of our conventional treatments are not efficient enough to combat this deadly disease. Harnessing the power of the immune system to target cancer cells is one of the most appealing methods for cancer therapy. Nucleotide-based cancer vaccines, especially deoxyribonucleic acid (DNA) cancer vaccines are viable novel cancer treatments that have recently garnered significant attention. DNA cancer vaccines are made of plasmid molecules that encode tumor-associated or tumor-specific antigens (TAAs or TSAs), and possibly some other immunomodulatory adjuvants such as pro-inflammatory interleukins. Following the internalization of plasmids into cells, their genes are expressed and the tumor antigens are loaded on major histocompatibility molecules to be presented to T-cells. After the T-cells have been activated, they will look for tumor antigens and destroy the tumor cells upon encountering them. As with any other treatment, there are pros and cons associated with using these vaccines. They are relatively safe, usually well-tolerated, stable, easily mass-produced, cost-effective, and easily stored and transported. They can induce a systemic immune response effective on both the primary tumor and metastases. The main disadvantage of DNA vaccines is their poor immunogenicity. Several approaches including structural modification, combination therapy with conventional and novel cancer treatments (such as chemotherapy, radiotherapy, and immune checkpoint blockade (ICB)), and the incorporation of adjuvants into the plasmid structure have been studied to enhance the vaccine's immunogenicity and improve the clinical outcome of cancer patients. In this review, we will discuss some of the most promising optimization strategies and examine some of the important trials regarding these vaccines.

Impact of Acetylation, Succinylation, and pH on DNA Packaging in PEI-Based Polyplexes

Polyethylenimine (PEI) is a widely used cationic polymer for nonviral gene delivery, often modified to enhance transfection efficiency and reduce cytotoxicity. This study investigates how acetylation, succinylation (acPEI and zPEI), and pH influence the internal DNA packaging of polyplexes. Both modifications alter physicochemical properties, leading to complexes that decondense more readily with increasing modification. X-ray scattering reveals that high acetylation produces loosely packed DNA, while succinylation unexpectedly tightens DNA packing at higher modification levels. Polyplexes formed at low pH (pH 4) are more stable and tightly packed than those formed at pH 7.5. Acidifying polyplexes initially formed at pH 7.5 induces structural rearrangement to tighter DNA packing accompanied by significant PEI release, providing direct evidence for models where free PEI aids endosomal escape. These findings challenge conventional assumptions about PEI behavior and offer new insights into DNA packaging, emphasizing tailored polymer modifications and pH conditions to optimize gene delivery.

Polymer Nano-Carrier-Mediated Gene Delivery: Visualizing and Quantifying DNA Encapsulation Using dSTORM

The success of gene therapy hinges on the effective encapsulation, protection, and compression of genes. These processes deliver therapeutic genes into designated cells for genetic repair, cellular behavior modification, or therapeutic effect induction. However, quantifying the encapsulation efficiency of small molecules of interest like DNA or RNA into delivery carriers remains challenging. This work shows how super-resolution microscopy, specifically direct stochastic optical reconstruction microscopy (dSTORM), can be employed to visualize and measure the quantity of DNA entering a single carrier. Utilizing pNIPAM/bPEI microgels as model nano-carriers to form polyplexes, DNA entry into the carrier is revealed across different charge ratios at temperatures below and above the volume phase transition of the microgel core. The encapsulation efficiency also depends on DNA length and shape. This work demonstrates the uptake of the carrier entity by primary derived macro-phages and showcases the cell viability of the polyplexes. The study shows that dSTORM is a potent tool for fine-tuning and creating polyplex microgel carrier systems with precise size, shape, and loading capacity at the individual particle level. This advancement shall contribute significantly to optimizing gene delivery systems.

Novel Gene Therapy Approaches for Targeting Neurodegenerative Disorders: Focusing on Delivering Neurotrophic Genes

Neurodegenerative illnesses (NDDs) like Alzheimer's, Parkinson's, amyotrophic lateral sclerosis, spinal muscular atrophy, and Huntington's disease have demonstrated considerable potential for gene therapy as a viable therapeutic intervention. NDDs are marked by the decline of neurons, resulting in changes in both behavior and pathology within the body. Strikingly, only symptomatic management is available without a cure for the NDDs. There is an unmet need for a permanent therapeutic approach. Many studies have been going on to target the newer therapeutic molecular targets for NDDs including gene-based therapy. Gene therapy has the potential to provide therapeutic benefits to a large number of patients with NDDs by offering mechanisms including neuroprotection, neuro-restoration, and rectification of pathogenic pathways. Gene therapy is a medical approach that aims to modify the biological characteristics of living cells by controlling the expression of specific genes in certain neurological disorders. Despite being the most complex and well-protected organ in the human body, there is clinical evidence to show that it is possible to specifically target the central nervous system (CNS). This provides hope for the prospective application of gene therapy in treating NDDs in the future. There are several advanced techniques available for using viral or non-viral vectors to deliver the therapeutic gene to the afflicted region. Neurotrophic factors (NTF) in the brain are crucial for the development, differentiation, and survival of neurons in the CNS, making them important in the context of various neurological illnesses. Gene delivery of NTF has the potential to be used as a therapeutic approach for the treatment of neurological problems in the brain. This review primarily focuses on the methodologies employed for delivering the genes of different NTFs to treat neurological disorders. These techniques are currently being explored as a viable therapeutic approach for neurodegenerative diseases. The article exclusively addresses gene delivery approaches and does not cover additional therapy strategies for NDDs. Gene therapy offers a promising alternative treatment for NDDs by stimulating neuronal growth instead of solely relying on symptom relief from drugs and their associated adverse effects. It can serve as a long-lasting and advantageous treatment choice for the management of NDDs. The likelihood of developing NDDs increases with age as a result of neuronal degradation in the brain. Gene therapy is an optimal approach for promoting neuronal growth through the introduction of nerve growth factor genes.

Tumor Microenvironment-Responsive Polymer-Based RNA Delivery Systems for Cancer Treatment

Ribonucleic acid (RNA) therapeutics offer a broad prospect in cancer treatment. However, their successful application requires overcoming various physiological barriers to effectively deliver RNAs to the target sites. Currently, a number of RNA delivery systems based on polymeric nanoparticles are developed to overcome these barriers in RNA delivery. This work provides an overview of the existing RNA therapeutics for cancer gene therapy, and particularly summarizes those that are entering the clinical phase. This work then discusses the core features and latest research developments of tumor microenvironment-responsive polymer-based RNA delivery carriers which are designed based on the pathological characteristics of the tumor microenvironment. Finally, this work also proposes opportunities for the transformation of RNA therapies into cancer immunotherapy methods in clinical applications.

Polymers for mRNA Delivery

mRNA delivery has emerged as a transformative approach in biotechnology and medicine, offering a versatile platform for the development of novel therapeutics. Unlike traditional small molecule drugs or protein-based biologics, mRNA therapeutics have the unique ability to direct cells to generate therapeutic proteins, allowing for precise modulation of biological processes. The delivery of mRNA into target cells is a critical step in realizing the therapeutic potential of this technology. In this review, our focus is on the latest advancements in designing functional polymers to achieve efficient mRNA delivery. Biodegradable polymers and low molecular weight polymers in addressing the balance in mRNA binding and release are summarized. Benefiting from the excellent performance of lipid nanoparticles in mRNA delivery, polymer/lipid hybrid nanostructures are also included. Finally, the challenges and future prospects in the development of polymer-based mRNA delivery systems are discussed.

Bioengineered Nanomaterials for siRNA Therapy of Chemoresistant Cancers

Chemoresistance remains a long-standing challenge after cancer treatment. Over the last two decades, RNA interference (RNAi) has emerged as a gene therapy modality to sensitize cancer cells to chemotherapy. However, the use of RNAi, specifically small-interfering RNA (siRNA), is hindered by biological barriers that limit its intracellular delivery. Nanoparticles can overcome these barriers by protecting siRNA in physiological environments and facilitating its delivery to cancer cells. In this review, we discuss the development of nanomaterials for siRNA delivery in cancer therapy, current challenges, and future perspectives for their implementation to overcome cancer chemoresistance.

Pichia pastoris-Derived β-Glucan Capsules as a Delivery System for DNA Vaccines

BACKGROUND/OBJECTIVES

DNA vaccines are rapidly produced and adaptable to different pathogens, but they face considerable challenges regarding stability and delivery to the cellular target. Thus, effective delivery methods are essential for the success of these vaccines. Here, we evaluated the efficacy of capsules derived from the cell wall of the yeast Pichia pastoris as a delivery system for DNA vaccines.

METHODS

The capsules were extracted from the yeast Pichia pastoris strain GS115, previously grown in a YPD medium. pVAX1 expression vector was adopted to evaluate the DNA vaccine insertion and delivery. Three encapsulation protocols were tested to identify the most effective in internalizing the plasmid. The presence of plasmids inside the capsules was confirmed by fluorescence microscopy, and the encapsulation efficiency was calculated by the difference between the initial concentration of DNA used for insertion and the concentration of unencapsulated DNA contained in the supernatant. The capsules were subjected to different temperatures to evaluate their thermostability and were co-cultured with macrophages for phagocytosis analysis. HEK-293T cells were adopted to assess the cytotoxicity levels by MTT assay.

RESULTS

The microscopy results indicated that the macrophages successfully phagocytosed the capsules. Among the protocols tested for encapsulation, the one with 2% polyethylenimine for internalization showed the highest efficiency, with an encapsulation rate above 80%. However, the vaccine capsules obtained with the protocol that used 5% NaCl showed better thermal stability and encapsulation efficiency above 63% without induction of cell viability loss in HEK 293T.

CONCLUSIONS

We successfully described a vaccine delivery system using yeast capsules derived from Pichia pastoris, demonstrating its potential for DNA vaccine delivery for the first time. Additional studies will be needed to characterize and improve this delivery strategy.

Sparsely PEGylated poly(beta-amino ester) polyplexes enhance antigen specific T-cell response of a bivalent SARS-CoV-2 DNA vaccine

DNA technology has emerged as a promising route to accelerated manufacture of sequence agnostic vaccines. For activity, DNA vaccines must be protected and delivered to the correct antigen presenting cells. However, the physicochemical properties of the vector must be carefully tuned to enhance interaction with immune cells and generate sufficient immune response for disease protection. In this study, we have engineered a range of polymer-based nanocarriers based on the poly(beta-amino ester) (PBAE) polycation platform to investigate the role that surface poly(ethylene glycol) (PEG) density has on pDNA encapsulation, formulation properties and gene transfectability both in vitro and in vivo. We achieved this by synthesising a non-PEGylated and PEGylated PBAE and produced formulations containing these PBAEs, and mixed polyplexes to tune surface PEG density. All polymers and co-formulations produced small polyplex nanoparticles with almost complete encapsulation of the cargo in all cases. Despite high gene transfection in HEK293T cells, only the fully PEGylated and mixed formulations displayed significantly higher expression of the reporter gene than the negative control in dendritic cells. Further in vivo studies with a bivalent SARS-CoV-2 pDNA vaccine revealed that only the mixed formulation led to strong antigen specific T-cell responses, however this did not translate into the presence of serum antibodies indicating the need for further studies into improving immunisation with polymer delivery systems.

An mRNA-encoded dominant-negative inhibitor of transcription factor RUNX1 suppresses vitreoretinal disease in experimental models

Messenger RNA (mRNA)-based therapies are a promising approach to medical treatment. Except for infectious diseases, no other disease has mRNA-based therapies available. The eye is an ideal model for mRNA therapeutic development because it requires limited dosing. Proliferative vitreoretinopathy (PVR) is a blinding condition caused by retinal detachment that now lacks available medical treatment, with surgery as the only treatment option. We previously implicated runt-related transcription factor-1 (RUNX1) as a driver of epithelial-to-mesenchymal transition (EMT) in PVR and as a critical mediator of aberrant ocular angiogenesis when up-regulated. On the basis of these findings, an mRNA was designed to express a dominant-negative inhibitor of RUNX1 (RUNX1-Trap). We show that RUNX1-Trap delivered in polymer-lipidoid complexes or lipid nanoparticles sequestered RUNX1 in the cytosol and strongly reduced proliferation in primary cell cultures established from fibrotic membranes derived from patients with PVR. We assessed the preclinical efficacy of intraocular delivery of mRNA-encoded RUNX1-Trap in a rabbit model of PVR and in a laser-induced mouse model of aberrant angiogenesis often used to study wet age-related macular degeneration. mRNA-encoded RUNX1-Trap suppressed ocular pathology, measured as pathological scores in the rabbit PVR model and leakage and lesion size in the laser-induced choroidal neovascularization mouse model. mRNA-encoded RUNX1-Trap also strongly reduced proliferation in a human ex vivo explant model of PVR. These data demonstrate the therapeutic potential of mRNA-encoded therapeutic molecules with dominant-negative properties, highlighting the potential of mRNA-based therapies beyond standard gene supplementation approaches.

PEGylation Can Effectively Strike a Balance in siRNA Delivery Performances of Guanidinylated Linear Synthetic Polypeptides with Potential Use for Transcriptional Gene Silencing

The prevailing design philosophy for polymeric vectors delivering siRNA is rooted in the post-transcriptional gene silencing (PTGS) mechanism. Yet, the transcriptional gene silencing (TGS) mechanism offers a potentially more durable silencing effect, which necessitates efficient siRNA delivery into the nucleus. However, it remains a challenge for the polymeric vectors to efficiently deliver siRNA into the nucleus. We have explored guanidinylated cyclic synthetic polypeptides (GCSPs) to enhance the nuclear delivery of siRNA, but an increased cytotoxicity and difficulty in producing the GCSPs on a large scale limit their utility. Herein, we simply prepare PEGylated guanidinylated linear synthetic polypeptides (PGLSPs) exhibiting improved membrane penetration, direct siRNA transport to the nucleus, reduced toxicity, high cellular uptake, and mitigation of protein corona formation. The PEGylation can effectively balance the vector's nuclear delivery capacity with other critical aspects of performances for siRNA delivery. Therefore, the PGLSPs hold promise as TGS-based delivery vectors, offering potential for future therapeutic applications.

Synthetic genomic nanomedicine with triple-responsiveness for systemic anti-tumor therapy

To overcome the biological barriers in the journey of systemic gene delivery, a multifaceted genomic synthetic nanomedicine was elaborated and strategically equipped with a multiple of intriguing responsiveness. Particularly, core-shell plasmid DNA condensates were created based on polyionic complexation with block copolymer of polyethylene glycol (PEG)-polylysine (PLys), namely, the nanoscaled PLys&pDNA nanoparticle tethered with the biocompatible PEG surroundings. Furthermore, redox-reversible disulfide crosslinking was introduced into PLys&pDNA nanoparticle to accomplish adequate structural stabilities, and thermal-responsive polypropylacrylamide (PNIPAM) was introduced as the secondary intermediate surroundings onto the pre-formulated PLys&pDNA nanoparticle with the aim of preventing the potential enzymatic degradation from the environmental nucleases. Hence, hundreds of times prolonged survival and retention was determined in pertinent to the blood circulation properties. Additionally, the installation of a guide ligand at the distal end of PEG segments was proposed to encourage selective tumor uptake. A linear peptide of GPLGVRG, which is selectively susceptible to digestion by the tumor-enriched matrix metalloproteinase 2 (MMP-2), was used as the linkage between the shell and core. This peptide has been shown to detach the bio-inert PEGylation, resulting in further facilitated cell endocytosis and intracellular trafficking activities. Hence, the precisely defined synthetic nanomedicine, which exhibits desirable characteristics, efficient expression of the therapeutic gene in the affected cells, and contributed to potent therapeutic efficacy in systemic treatment of intractable tumors by encapsulating the anti-angiogenic gene.

Design and synthesis of a shikimoyl-functionalized cationic di-block copolypeptide for cancer cell specific gene transfection

Targeted and efficient gene delivery systems hold tremendous potential for the improvement of cancer therapy by enabling appropriate modification of biological processes. Herein, we report the design and synthesis of a novel cationic di-block copolypeptide, incorporating homoarginine (HAG) and shikimoyl (LSA) functionalities (HDA-b-PHAGm-b-PLSAn), tailored for enhanced gene transfection specifically in cancer cells. The di-block copolypeptide was synthesized via sequential N-carboxyanhydride (NCA) ring-opening polymerization (ROP) techniques and its physicochemical properties were characterized, including molecular weight, dispersity, secondary conformation, size, morphology, and surface charge. In contrast to the cationic poly-L-homoarginine, we observed a significantly reduced cytotoxic effect of this di-block copolypeptide due to the inclusion of the shikimoyl glyco-polypeptide block, which also added selectivity in internalizing particular cells. This di-block copolypeptide was internalized via mannose-receptor-mediated endocytosis, which was investigated by competitive receptor blocking with mannan. We evaluated the transfection efficiency of the copolypeptide in HEK 293T (noncancerous cells), MDA-MB-231 (breast cancer cells), and RAW 264.7 (dendritic cells) and compared it with commonly employed transfection agents (Lipofectamine). Our findings demonstrate that the homoarginine and shikimoyl-functionalized cationic di-block copolypeptide exhibits potent gene transfection capabilities with minimal cytotoxic effects, particularly in cancer cells, while it is ineffective for normal cells, indicative of its potential as a promising platform for cancer cell-specific gene delivery systems. To evaluate this, we delivered an artificially designed miRNA-plasmid against Hsp90 (amiR-Hsp90) which upon successful transfection depleted the Hsp90 (a chaperone protein responsible for tumour growth) level specifically in cancerous cells and enforced apoptosis. This innovative approach offers a new avenue for the development of targeted therapeutics with an improved efficacy and safety profile in cancer treatment.

Polymers as Efficient Non-Viral Gene Delivery Vectors: The Role of the Chemical and Physical Architecture of Macromolecules

Gene therapy is the technique of inserting foreign genetic elements into host cells to achieve a therapeutic effect. Although gene therapy was initially formulated as a potential remedy for specific genetic problems, it currently offers solutions for many diseases with varying inheritance patterns and acquired diseases. There are two major groups of vectors for gene therapy: viral vector gene therapy and non-viral vector gene therapy. This review examines the role of a macromolecule's chemical and physical architecture in non-viral gene delivery, including their design and synthesis. Polymers can boost circulation, improve delivery, and control cargo release through various methods. The prominent examples discussed include poly-L-lysine, polyethyleneimine, comb polymers, brush polymers, and star polymers, as well as hydrogels and natural polymers and their modifications. While significant progress has been made, challenges still exist in gene stabilization, targeting specificity, and cellular uptake. Overcoming cytotoxicity, improving delivery efficiency, and utilizing natural polymers and hybrid systems are vital factors for prospects. This comprehensive review provides an illuminating overview of the field, guiding the way toward innovative non-viral-based gene delivery solutions.

Delivery of PAMAM dendrimers and dendriplexes across natural barriers (blood-brain barrier and placental barrier) in healthy pregnant mice

Gene therapy is an important tool for treating fetal diseases that allows for the delivery and integration of therapeutic genes into the genome of cells carrying mutations. Nanomolecules, like PAMAM dendrimers, have recently come into wider use for carrying vectors as they have several advantages over viral vectors. Namely, (1) tunable size and surface chemistry, (2) uniform size, (3) the ability to target specific tissues, and (4) the ability to carry large biomolecules and drugs. Recently, we demonstrated that 4th generation (G4) PAMAM dendrimer with a cystamine core and a non-toxic surface having 90% -OH and 10% -NH2 groups (D-Cys) could cross the blood-brain barrier following injection into the bloodstream. In the current study, as a proof of concept, we delivered the dendrimers alone (D-Cys) tagged with Cy5.5 (D-Cys-cy5.5) to healthy pregnant C57BL/6J mice to determine the fate of these dendrimers in the pregnant mice as well as in the fetus. Systematic diffusion of the D-Cys-cy5.5 was evaluated on gestational day 17 (3 days after injection) using in vivo imaging. This revealed that the dendrimer was taken up into circulation and away from the injection site. Analysis of sections by fluorescence microscopy showed that D-Cys-cy5.5 was able to successfully cross the maternal blood-brain barrier. However, analysis of the fetal brains failed to detect dendrimers in the central nervous system (CNS). Instead, they appeared to be retained in the placenta. This is one of the first studies to analyze the distribution of surface-modified PAMAM dendrimer in the pregnant mouse and fetus following systemic injection.

Covalent recruitment of polymers and nanoparticles onto glycan-engineered cells enhances gene delivery during short exposure

Non-viral gene delivery with cationic polymers/nanoparticles relies on iterative optimization of the carrier to achieve delivery. Here we demonstrate, instead, that precision engineering of cell surfaces to covalently capture a polyplex accelerates gene delivery within just 10 min of exposure. Azides were installed into cell-surface sialic acids, which enabled the rapid and selective recruitment of cyclooctyne-functional polyplexes, leading to increased delivery of fluorescent cargo, and also increased plasmid expression and siRNA knockdown. Covalent delivery enhancement was also shown for a polymer-coated nanoparticle delivery system. This validates using cellular metabolic engineering (or other synthetic biology) tools to overcome payload delivery challenges.

Harnessing Guanidinium and Imidazole Functional Groups: A Dual-Charged Polymer Strategy for Enhanced Gene Delivery

Histidine and arginine are two amino acids that exhibit beneficial properties for gene delivery. In particular, the imidazole group of histidine facilitates endosomal release, while the guanidinium group of arginine promotes cellular entry. Consequently, a dual-charged copolymer library based on these amino acids was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The content of the N-acryloyl-l-histidine (His) monomer was systematically increased, while maintaining consistent levels of methyl N-acryloyl-l-argininate hydrochloride (ArgOMe) or N-(4-guanidinobutyl)acrylamide hydrochloride (GBAm). The resulting polymers formed stable, nanosized polyplexes when complexed with nucleic acids. Remarkably, candidates with increased His content exhibited reduced cytotoxicity profiles and enhanced transfection efficiency, particularly retaining this performance level at lower pDNA concentrations. Furthermore, endosomal release studies revealed that increased His content improved endosomal release, while ArgOMe improved cellular entry. These findings underscore the potential of customized dual-charged copolymers and the synergistic effects of His and ArgOMe/GBAm in enhancing gene delivery.

Advances in Nonviral mRNA Delivery Materials and Their Application as Vaccines for Melanoma Therapy

Messenger RNA (mRNA) vaccines are promising platforms for cancer immunotherapy because of their potential to encode for a variety of tumor antigens, high tolerability, and capacity to induce strong antitumor immune responses. However, the clinical translation of mRNA cancer vaccines can be hindered by the inefficient delivery of mRNA in vivo. In this review, we provide an overview of mRNA cancer vaccines by discussing their utility in treating melanoma. Specifically, we begin our review by describing the barriers that can impede mRNA delivery to target cells. We then review native mRNA structure and discuss various modification methods shown to enhance mRNA stability and transfection. Next, we outline the advantages and challenges of three nonviral carrier platforms (lipid nanoparticles, polymeric nanoparticles, and lipopolyplexes) frequently used for mRNA delivery. Last, we summarize preclinical and clinical studies that have investigated nonviral mRNA vaccines for the treatment of melanoma. In writing this review, we aim to highlight innovative nonviral strategies designed to address mRNA delivery challenges while emphasizing the exciting potential of mRNA vaccines as next-generation therapies for the treatment of cancers.

Optimizing Biocompatibility and Gene Delivery with DMAEA and DMAEAm: A Niacin-Derived Copolymer Approach

Gene therapy is pivotal in nanomedicine, offering a versatile approach to disease treatment. This study aims to achieve an optimal balance between biocompatibility and efficacy, which is a common challenge in the field. A copolymer library is synthesized, incorporating niacin-derived monomers 2-acrylamidoethyl nicotinate (AAEN) or 2-(acryloyloxy)ethyl nicotinate (AEN) with N,N-(dimethylamino)ethyl acrylamide (DMAEAm) or hydrolysis-labile N,N-(dimethylamino)ethyl acrylate (DMAEA). Evaluation of the polymers' cytotoxicity profiles reveals that an increase in AAEN or DMAEA molar ratios correlates with improved biocompatibility. Remarkably, an increase in AAEN in both DMAEA and DMAEAm copolymers demonstrated enhanced transfection efficiencies of plasmid DNA in HEK293T cells. Additionally, the top-performing polymers demonstrate promising gene expression in challenging-to-transfect cells (THP-1 and Jurkat cells) and show no significant effect on modulating immune response induction in ex vivo treated murine monocytes. Overall, the best performing candidates exhibit an optimal balance between biocompatibility and efficacy, showcasing potential advancements in gene therapy.

Modulating efficacy and cytotoxicity of lipoamino fatty acid nucleic acid carriers using disulfide or hydrophobic spacers

Double pH-responsive xenopeptides comprising polar ionizable succinoyl tetraethylene pentamine (Stp) motifs and lipophilic ionizable lipoamino fatty acids (LAFs) were recently found to efficiently transfect mRNA and pDNA at low doses. However, potency was often accompanied with cytotoxicity at higher doses. Insertion of bioreducible disulfide building blocks (ssbb) or non-reducible hydrophobic spacers between polar and apolar ionizable domains of LAF-Stp carriers should mitigate toxicity of xenopeptides. Carriers showed stable nucleic acid complexation and endosomal pH-dependent lytic activities, both of which were abolished after reductive cleavage of ssbb-containing carriers. For pDNA, U-shaped carriers with one Stp and two LAF units or bundle carriers with two Stps and four LAFs displayed highest potency. For mRNA, best transfection was achieved with bundle carriers with one Stp and four LAFs. Both the ssbb and hydrophobic spacer containing analogs displayed improved metabolic activity, reduced membrane damage, and improved cell growth. The ssbb carriers were most beneficial regarding living cell count and low apoptosis rates. Mechanistically, inserted spacers decelerated the transfection kinetics and altered the requirement of endosomal protonation. Overall, mRNA and pDNA carriers with improved biocompatibility have been designed, with their high potency illustrated in transfection of various cell lines including low passage number colon carcinoma cells.

Polyamidoamine Dendrimers: Brain-Targeted Drug Delivery Systems in Glioma Therapy

Glioma is the most common primary intracranial tumor, which is formed by the malignant transformation of glial cells in the brain and spinal cord. It has the characteristics of high incidence, high recurrence rate, high mortality and low cure rate. The treatments for glioma include surgical removal, chemotherapy and radiotherapy. Due to the obstruction of the biological barrier of brain tissue, it is difficult to achieve the desired therapeutic effects. To address the limitations imposed by the brain's natural barriers and enhance the treatment efficacy, researchers have effectively used brain-targeted drug delivery systems (DDSs) in glioma therapy. Polyamidoamine (PAMAM) dendrimers, as branched macromolecular architectures, represent promising candidates for studies in glioma therapy. This review focuses on PAMAM-based DDSs in the treatment of glioma, highlighting their physicochemical characteristics, structural properties as well as an overview of the toxicity and safety profiles.

Single-Stranded Nucleic Acid Transmembrane Molecular Carriers Based on Positively Charged Helical Foldamers

Transmembrane delivery of biologically active nucleic acids is an important process in cells and has inspired one to develop advanced drug delivery techniques. In this contribution, molecular-level single-stranded nucleic acid transmembrane carriers are reported based on 3.2 nm long Huc's foldamers (AOrnQ3Q3)8 and (mQ3Q2)8 with linearly and helically aligned positive charges, respectively. These two foldamers not only show very strong DNA affinity via electrostatic interactions but also discriminatively bind single-stranded DNA (ss-DNA) and double-stranded DNA (ds-DNA), corroborating the importance of precise charge arrangement in the electrostatic interactions. More importantly, these two foldamers are capable of efficiently transporting ss-DNA across the lipid membranes, and the ss-DNA transport activity of (AOrnQ3Q3)8 with linearly aligned charges is higher than that of (mQ3Q2)8 with helically aligned charges. Thus a type of novel single-stranded nucleic acid transmembrane molecular carriers based on positively charged helical foldamers are introduced. Further, effective and enhanced expression in EGFP-mRNA transfection experiments strongly demonstrates the potential of positively charged foldamers for RNA transmembrane transport and therapy.

Unidirectional gene delivery electrospun fibrous membrane via charge repulsion for tendon repair

Gene therapy is capable of efficiently regulating the expression of abnormal genes in diseased tissues and expected to be a therapeutic option for refractory diseases. However, unidirectional targeting gene therapy is always desired at the tissue interface. In this study, inspired by the principle that like charges repulse each other, a positively charged micro-nano electrospun fibrous membrane with dual-layer structure was developed by electrospinning technology to achieve unidirectional delivery of siRNA-loaded cationic nanocarriers, thus realizing unidirectional gene therapy at the tendon-paratenon interface. Under the charge repulsion of positively charged layer, more cationic COX-2 siRNA nanocarriers were enriched in peritendinous tissue, which not only improved the bioavailability of the gene drug to prevent the peritendinous adhesion formation, but also avoided adverse effects on the fragile endogenous healing of tendon itself. In summary, this study provides an innovative strategy for unidirectional targeting gene therapy of tissue interface diseases by utilizing charge repulsion to facilitate unidirectional delivery of gene drugs.

Nanoplatform-Based In Vivo Gene Delivery Systems for Cancer Therapy

Gene therapy uses modern molecular biology methods to repair disease-causing genes. As a burgeoning therapeutic, it has been widely applied for cancer therapy. Since 1989, there have been numerous clinical gene therapy cases worldwide. However, a few are successful. The main challenge of clinical gene therapy is the lack of efficient and safe vectors. Although viral vectors show high transfection efficiency, their application is still limited by immune rejection and packaging capacity. Therefore, the development of non-viral vectors is overwhelming. Nanoplatform-based non-viral vectors become a hotspot in gene therapy. The reasons are mainly as follows. 1) Non-viral vectors can be engineered to be uptaken by specific types of cells or tissues, providing effective targeting capability. 2) Non-viral vectors can protect goods that need to be delivered from degradation. 3) Nanoparticles can transport large-sized cargo such as CRISPR/Cas9 plasmids and nucleoprotein complexes. 4) Nanoparticles are highly biosafe, and they are not mutagenic in themselves compared to viral vectors. 5) Nanoparticles are easy to scale preparation, which is conducive to clinical conversion and application. Here, an overview of the categories of nanoplatform-based non-viral gene vectors, the limitations on their development, and their applications in cancer therapy.

A Lung-Expressing mRNA Delivery Platform with Tunable Activity in Hypoxic Environments

Messenger RNA (mRNA) delivery platforms often facilitate protein expression in the liver following intravenous injection and have been optimized for use in normally oxygenated cells (21% O2 atmosphere). However, there is a growing need for mRNA therapy in diseases affecting non-liver organs, such as the lungs. Additionally, many diseases are characterized by hypoxia (<21% O2 atmosphere), a state of abnormally low oxygenation in cells and tissues that can reduce the efficacy of mRNA therapies by upwards of 80%. Here, we report a Tunable Lung-Expressing Nanoparticle Platform (TULEP) for mRNA delivery, whose properties can be readily tuned for optimal expression in hypoxic environments. Briefly, our study begins with the synthesis and characterization of a novel amino acrylate polymer that can be effectively complexed with mRNA payloads into TULEPs. We study the efficacy and mechanism of mRNA delivery using TULEP, including analysis of the cellular association, endocytosis mechanisms, endosomal escape, and protein expression in a lung cell line. We then evaluate TULEP under hypoxic conditions and address hypoxia-related deficits in efficacy by making our system tunable with adenosine triphosphate (ATP). Finally, we conclude our study with an in vivo analysis of mRNA expression, biodistribution, and tolerability of the TULEP platform in mice. In presenting these data, we hope that our work highlights the utility of TULEPs for tunable and effective mRNA delivery while more broadly highlighting the utility of considering oxygen levels when developing mRNA delivery platforms.

Precision in Action: The Role of Clustered Regularly Interspaced Short Palindromic Repeats/Cas in Gene Therapies

Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-associated enzyme-CAS holds great promise for treating many uncured human diseases and illnesses by precisely correcting harmful point mutations and disrupting disease-causing genes. The recent Food and Drug Association (FDA) approval of the first CRISPR-based gene therapy for sickle cell anemia marks the beginning of a new era in gene editing. However, delivering CRISPR specifically into diseased cells in vivo is a significant challenge and an area of intense research. The identification of new CRISPR/Cas variants, particularly ultra-compact CAS systems with robust gene editing activities, paves the way for the low-capacity delivery vectors to be used in gene therapies. CRISPR/Cas technology has evolved beyond editing DNA to cover a wide spectrum of functionalities, including RNA targeting, disease diagnosis, transcriptional/epigenetic regulation, chromatin imaging, high-throughput screening, and new disease modeling. CRISPR/Cas can be used to engineer B-cells to produce potent antibodies for more effective vaccines and enhance CAR T-cells for the more precise and efficient targeting of tumor cells. However, CRISPR/Cas technology has challenges, including off-target effects, toxicity, immune responses, and inadequate tissue-specific delivery. Overcoming these challenges necessitates the development of a more effective and specific CRISPR/Cas delivery system. This entails strategically utilizing specific gRNAs in conjunction with robust CRISPR/Cas variants to mitigate off-target effects. This review seeks to delve into the intricacies of the CRISPR/Cas mechanism, explore progress in gene therapies, evaluate gene delivery systems, highlight limitations, outline necessary precautions, and scrutinize the ethical considerations associated with its application.

Regioselective Palladium-Catalyzed Chain-Growth Allylic Amination Polymerization of Vinyl Aziridines

Organometallic-mediated chain growth polymerization of readily accessible chemical building blocks is responsible for important commercial and technological advances in polymer science, but the incorporation of heteroatoms into the polymer backbone through these mechanisms remains a challenge. Transition metal π-allyl complexes are well-developed organometallic intermediates for carbon-heteroatom bond formation in small-molecule catalysis yet remain underexplored in polymer science. Here, we developed a regioselective palladium-phosphoramidite-catalyzed chain-growth allylic amination polymerization of vinyl aziridines for the synthesis of novel nitrogen-rich polymers via ambiphilic π-allyl complexes. The polymerization accessed a linear microstructure with four carbons between each nitrogen, which is challenging to achieve through other chain-growth polymerization approaches. The highly regioselective allylic amination polymerization demonstrated the characteristics of a controlled polymerization and was able to achieve molar masses exceeding 20 kg mol-1 with low dispersities (D̵ < 1.3). The identification of the polymer structure and well-defined chain ends were supported by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and chain extension experiments demonstrate opportunities for building more complex materials from this method. A Hammett study was performed to understand the role of the catalyst and monomer structure on regioselectivity, and the data supported a mechanism wherein regioselectivity was primarily controlled by the ligand-metal complex. Postpolymerization desulfonylation provided access to a novel polyamine that demonstrated broad anticancer activity in vitro, which highlights the benefits of unlocking novel polyamine microstructures through regioselective chain-growth allylic amination polymerization.