The role of lipid components in lipid nanoparticles for vaccines and gene therapy

Liposomes as versatile agents for the management of traumatic and nontraumatic central nervous system disorders: drug stability, targeting efficiency, and safety

Various nanoparticle-based drug delivery systems for the treatment of neurological disorders have been widely studied. However, their inability to cross the blood-brain barrier hampers the clinical translation of these therapeutic strategies. Liposomes are nanoparticles composed of lipid bilayers, which can effectively encapsulate drugs and improve drug delivery across the blood-brain barrier and into brain tissue through their targeting and permeability. Therefore, they can potentially treat traumatic and nontraumatic central nervous system diseases. In this review, we outlined the common properties and preparation methods of liposomes, including thin-film hydration, reverse-phase evaporation, solvent injection techniques, detergent removal methods, and microfluidics techniques. Afterwards, we comprehensively discussed the current applications of liposomes in central nervous system diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, traumatic brain injury, spinal cord injury, and brain tumors. Most studies related to liposomes are still in the laboratory stage and have not yet entered clinical trials. Additionally, their application as drug delivery systems in clinical practice faces challenges such as drug stability, targeting efficiency, and safety. Therefore, we proposed development strategies related to liposomes to further promote their development in neurological disease research.

A factorial design-optimized microfluidic LNP vaccine elicits potent magnesium-adjuvating cancer immunotherapy

Human papillomavirus (HPV)-associated cancers remain a critical health challenge, prompting the development of effective therapeutic vaccines. This study presents a lipid nanoparticle (LNP)-based vaccine co-loading E7 antigen peptide and magnesium ions as the adjuvant. Microfluidic technology was employed to optimize LNP preparation and formulation, ensuring efficient co-delivery of antigen and adjuvant. Magnesium ions were chosen over conventional aluminum-based adjuvants, which often suffer from limited efficacy and adverse effects, particularly for cancer immunotherapy. Compared to aluminum, magnesium ions exhibited superior capabilities in enhancing T-cell activation and promoting cellular immune response. Mechanistic insights suggest that magnesium ions facilitate dendritic cell maturation and antigen presentation via a collagen-CD36 axis, contributing to the adjuvant activity of magnesium. Through design of experiments (DoE) optimization, the LNP formulation was tailored for enhanced encapsulation and stability, positioning it as a targeted system for immune activation. These findings support the promise of magnesium ions as effective and safer adjuvants in LNP-based vaccines, marking a potential advancement for therapeutic cancer vaccination.

Investigation of the impact of lipid nanoparticle compositions on the delivery and T cell response of circRNA vaccine

Circular RNA (circRNA) is an emerging class of vaccines for various diseases, such as cancer immunotherapy. For cancer therapeutic vaccines, it is critical to deliver circRNA to lymphoid tissues such as lymph nodes (LNs) and dendritic cells (DCs) and then elicit antigen-specific T cell responses. Lipid nanoparticles (LNPs) have shown great success for mRNA vaccines and may also have great potential as nanocarriers for circRNA vaccines. Here, we studied the impact of LNP composition on the efficiency of immune delivery, protein expression, and the T cell responses for circRNA vaccine. First, we used model mRNA and circRNA encoding firefly luciferase (mRNA-fLuc) to study protein expression and used two small circRNA vaccines to study T cell responses. We investigated a combination of six ionizable lipids, three helper lipids, and six different molar ratios of cholesterol and β-sitosterol for their impact on the physicochemical properties of RNA LNPs, in vitro DC transfection, in vivo protein expression in draining LNs, and antigen-specific T cell responses. Among these ionizable lipids, SM-102 was the most effective for DC transfection and enabling circRNA vaccines to elicit T cell responses. DOPE and β-sitosterol incorporation in LNPs resulted in efficient protein expression, albeit β-sitosterol incorporation appeared to be associated with reduced T cell response. Overall, circRNA was efficiently delivered to DCs and macrophages in mouse draining lymph nodes by LNPs of SM-102 (50 %), cholesterol (38.5 %), DOPE (10 %), and DMG-PEG2000 (1.5 %), resulting in the induction of potent antigen-specific CD8+ T cell response in mice. These findings may provide insights into designing the compositions of LNPs as the carrier for circRNA therapeutics and vaccines.

Pancreas-targeted lipid nanoparticles for relatively non-invasive interleukin-12 mRNA therapy in orthotopic pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) represents 90 % of pancreatic cancers and shows limited response to immune therapy owing to the highly immunosuppressive tumor microenvironment (TME). Cytokine-encoded mRNA therapy demonstrates a great promise in converting "cold" tumors into "hot" ones, while it is typically administered through intratumoral injection and applicable only to superficial tumors, which limites their application in PDAC. In this study, we design and develop a lipid nanoparticle (LNP) delivery system capable of targeting pancreatic tissue via intraperitoneal (I.P.) injection. This system not only efficiently delivers mRNA to pancreatic tissues but also selectively targets immune cells in PDAC. A single I.P. injection of LNP encapsulating interleukin-12 (IL-12) mRNA (LNP/mIL-12) activates both myeloid and lymphoid cells in PDAC, reprogramming the immunosuppressive TME. Remarkably, I.P. injection of LNP/mIL-12 induces eradication of orthotopic PDAC in some cases. Our work represents the first relatively non-invasive method to deliver IL-12 mRNA for targeted treatment of orthotopic PDAC, offering a novel approach for PDAC immunotherapy.

Dual centrifugation as fast and novel screening approach for optimal RNA loaded lipid-based nanoparticles

The last decade has shown increased benefits for non-viral gene delivery. To overcome the challenges of nucleic acid administration, appropriate drug delivery systems (DDS) are required. The recently approved RNA formulations have demonstrated that lipid nanoparticles (LNPs) are suitable DDS for delivering RNAs. LNPs are commonly composed of cationic and/or ionizable lipids, helper lipids and PEGylated lipids. Conventional manufacturing procedures for LNPs are mixing systems, such as microfluidics, with drawbacks in terms of time and resource consumption. The LNPs produced also pose problems with storage stability. Based on a microRNA (miRNA) model, we present dual centrifugation (DC) as a novel and reproducible way for preparing RNA loaded LNP formulations via in-vial homogenization. Our formulations show promising results in size characteristics, as well as in their cell performance. Depending on the lipid composition of the LNPs, a remarkable knockdown efficiency is achieved. With a net formulation time of 7 min, an enormously fast approach can be presented. DC offers the capability for fast LNP screenings, with a loading capacity of up to 40 vials per run. The simplicity of the method could take advantage of bedside preparation, overcoming the hurdles of storage stability for LNP formulations.

Local delivery of lipid-based nanoparticles containing microbial nucleic acid for osteoimmunomodulation

Osteoimmunomodulation is a strategy to promote bone regeneration in implants by modifying the immune environment. CpG-containing oligonucleotides type C (CpG ODN C) and Polyinosinic:polycytidylic acid (Poly[I:C]) are analogs of microbial nucleic acids that have been studied for various immunotherapeutic applications. This research investigates the potential of CpG ODN C and Poly(I:C) as an osteoimmunomodulatory agent for bone regenerative purposes. We encapsulated each nucleic acid in a lipid-based nanoparticle to facilitate the delivery into intracellular pathogen recognition receptors in immune cells. The lipid-based nanoparticles were ±250 nm in size with a negative charge (-36 to -40 mV) and an encapsulation efficiency of ±60 %. Lipid-based nanoparticles containing nucleic acids, Lip/CpG ODN C and Lip/Poly(I:C), increased the production of TNF, IL-6, and IL-10 by primary human macrophages compared to free-form nucleic acids. Conditioned medium from macrophages treated with CpG ODN C (10 µg/ml) and Lip/CpG ODN C (0.1, 1, and 10 µg/ml) promoted osteoblast differentiation of human mesenchymal stromal cells by 2.6-fold and 3-fold, respectively; no effect was seen for Lip/Poly(I:C). Bone implants were prepared, consisting of a biphasic calcium phosphate scaffold, bone morphogenetic protein (BMP) 2, and lipid-based nanoparticles suspended in gelatin methacryloyl (GelMA) hydrogel. Implants were evaluated for de novo bone formation in an extra-skeletal implantation model in rabbits for 5 weeks. Based on the particles suspended in GelMA, six groups of implants were prepared: Lip/CpG ODN C, Lip/Poly(I:C), Lip (empty), CpG ODN C, Poly(I:C), and a control group consisting of empty GelMA. After 5 weeks, healthy bone tissue formed in all of the implants with active osteoblast and osteoclast activity, however, the amount of new bone volume and scaffold degradation were similar for all implants. We suggest that the working concentrations of the nucleic acids employed were inadequate to induce a relevant inflammatory response. Additionally, the dosage of BMP-2 used may potentially mask the immune-stimulatory effect. Lip/CpG ODN C holds potential as a bioactive agent for osteoimmunomodulation, although further in vivo demonstration should corroborate the current in vitro findings.

Click Lipid Nanoparticles for the Delivery of mRNA to Metabolically Labeled Cancer Cells

Lipid nanoparticle (LNP)-based mRNA delivery has a lot of potential in combating a wide range of diseases, but delivering mRNA to specific cell types continues to be challenging. Despite recent advances in organ and cell specificity, the majority of clinical LNP systems cannot fully release their payload to a targeted site. Incorporating active targeting moieties into LNPs is highly desired to expand nanomedicine applications. In this Letter, we developed LNPs that harness the power of bioorthogonal "click" azide-alkyne chemical reactions. We show that the plasma membranes of cancer cells can be labeled with azide groups by metabolic sugar labeling, and these azide groups can react with dibenzocyclooctyne (DBCO) on LNPs to achieve specific binding. To achieve this, we synthesized new and versatile lipids by functionalizing DBCO groups to phospholipids with or without a poly(ethylene glycol) (PEG) linker. The DBCO lipids were successfully formulated into DBCO-LNPs comprising other standard lipid compounds. When using these DBCO-LNPs to deliver mRNA to metabolically labeled cells, DBCO-LNPs showed a remarkable ability to preferentially deliver mRNA to azide-labeled cells. Removing PEG linkers from DBCO lipids enables better integration and retention in the LNP, and the higher the amount of DBCO lipid, the stronger the targeting effect. This work demonstrates that cell-specific targeting can be achieved utilizing azide-alkyne ″click″ chemistry and could inspire the development of the next generation of LNPs for active cyto-tropic nanomedicines.

Cyclen-based lipidoids for mRNA delivery and immunotherapy

As mRNA vaccines continue to gain widespread attention, the development of lipid nanoparticles (LNPs), as the preferred platform for mRNA delivery, has become a key focus of research. 1,4,7,10-Tetraazacyclododecane (cyclen), with its excellent protonation capability and ease of modification, has emerged as a promising candidate for the ionizable head group of lipid materials. In this study, a series of cyclen-based lipidoids with different linkages and hydrophobic tails was designed and conveniently synthesized. Structure-activity relationship studies were performed to screen out the carriers capable of efficient mRNA delivery and with potential for tumor therapeutic applications. In vivo biodistribution experiments in mice revealed that the lipidoid OEs-K, containing both hydroxyl and ester groups in its linkage, exhibited high mRNA delivery efficiency and lymph node-targeting properties. Using a subcutaneous EG.7-OVA tumor model in mice, the delivery of tumor antigen OVA mRNA using the lipidoid material was evaluated for its antitumor immunotherapeutic potential. Results demonstrated that LNPs formulated with OEs-K promoted dendritic cell uptake in lymph nodes, effectively activated immune responses, and inhibited tumor growth. Hematological and histopathological evaluations indicated no significant toxicity to the body. This study provides insights into the design and development of carrier materials for mRNA vaccines.

A platform method for simultaneous quantification of lipid and nucleic acid components in lipid nanoparticles

Nucleic acid-based medicines have achieved significant advancements in recent years, with lipid nanoparticles (LNPs) being a pivotal platform for their delivery. However, the complexity of LNP presents significant challenges, requiring analytical methods to identify and quantify individual components to guide formulation development and ensure quality and safety. Current approaches often perform nucleic acid and lipid analysis separately and focus on a single type of formulation, highlighting the need for a simple platform method that can be applied to diverse formulations. We present a platform ion-pair reversed-phase HPLC method with UV and charged aerosol detection (CAD) to simultaneously separate and quantify lipid and nucleic acid components in LNPs. The method separated and quantified 12 lipid species and three types of nucleic acids (antisense oligonucleotide, single-guide RNA, and mRNA), covering a broad range of therapeutic cargoes. Notably, this can be achieved for the first time by one HPLC run with one-step facile sample preparation. Specifically, we used a simple buffer containing Triton and heparin to enable the single-step, simultaneous extraction of both nucleic acid and lipid components from LNPs, achieving quantification recoveries of 90-110 %. We further applied this method and addressed process and quality control challenges of LNPs, including the recovery rate of individual LNP components after purification and simultaneous quantification of co-loaded, different nucleic acid species for potential gene editing applications. This new platform method offers a robust and widely applicable tool to assess the quality of lipid-based nucleic acid therapies.

A Post-Encapsulation Method for the Preparation of mRNA-LNPs via the Nucleic Acid-Bridged Fusion of mRNA-Free LNPs

Lipid nanoparticles with encapsulated mRNA (mRNA-LNPs) have become key modalities for personalized medicines and RNA vaccines. Once the platform technology is established, the mRNA-LNPs could be applicable to a variety of protein-based therapeutic strategies. A post-encapsulation method, in which the mRNA solution is incubated with preformed mRNA-free LNPs to prepare the mRNA-LNPs, would accelerate the development of RNA-based therapeutics since even nonexperts could manufacture the mRNA-LNPs. In this study, we describe that the post-encapsulation of mRNA into mRNA-free LNPs is accompanied by "nucleic acid-bridged fusion" of them. The adsorption of mRNA onto mRNA-free LNPs via electrostatic interactions and the internalization of mRNA into the LNPs via particle-to-particle fusion are two steps that occur at different levels of pH. To complete post-encapsulation using only one-step mixing, the pH must be controlled within a limited region where both processes occur simultaneously. The size of the mRNA-free LNPs determines the effectiveness of mRNA loading.

Generation of an inflammatory niche in a hydrogel depot through recruitment of key immune cells improves efficacy of mRNA vaccines

Messenger RNA (mRNA) delivered in lipid nanoparticles (LNPs) rose to the forefront of vaccine candidates during the COVID-19 pandemic due to scalability, adaptability, and potency. Yet, there remain critical areas for improvements of these vaccines in durability and breadth of humoral responses. In this work, we explore a modular strategy to target mRNA/LNPs to antigen-presenting cells with an injectable polymer-nanoparticle (PNP) hydrogel technology, which recruits key immune cells and forms an immunological niche in vivo. We characterize this niche on a single-cell level and find it is highly tunable through incorporation of adjuvants like MPLAs and 3M-052. Delivering commercially available severe acute respiratory syndrome coronavirus 2 mRNA vaccines in PNP hydrogels improves the durability and quality of germinal center reactions, and the magnitude, breadth, and durability of humoral responses. The tunable immune niche formed within PNP hydrogels effectively skews immune responses based on encapsulated adjuvants, creating opportunities to precisely modulate mRNA/LNP vaccines for various indications from infectious diseases to cancers.

Role of PEGylated lipid in lipid nanoparticle formulation for in vitro and in vivo delivery of mRNA vaccines

mRNA-loaded lipid nanoparticles (mRNA-LNPs) hold great potential for disease treatment and prevention. LNPs are normally made from four lipids including ionizable lipid, helper lipid, cholesterol, and PEGylated lipid (PEG-lipid). Although PEG-lipid has the lowest content, it plays a crucial role in the effective delivery of mRNA-LNPs. However, previous studies have yet to elucidate the key factors of PEG-lipid that influence the properties of LNPs. This study reported how PEG-lipid content, lipid tail length, and chemical linkage between PEG and lipid affected in vitro and in vivo properties of mRNA-LNPs. Forty-eight LNP formulations were prepared and characterized. The results revealed that a PEG-lipid molar content exceeding 3.0 % significantly reduced the encapsulation efficiency of mRNA in LNPs via manual mixing. An increased PEG-lipid content also significantly decreased mRNA translation efficiency. Although the chemical linkage had minimal impact, the lipid tail length of PEG-lipid significantly affected the properties of mRNA-LNPs, irrespective of whether the LNPs were prepared using manual or microfluidic mixing. mRNA-LNPs made from ALC-0159 with C14 lipid tails, which is used in Pfizer/BioNTech COVID-19 mRNA vaccines, or C16-Ceramide-PEG preferably accumulated in the liver, while mRNA-LNPs prepared from C8-Ceramide-PEG were largely found in the lymph nodes. In a mouse SARS-CoV-2 Delta variant spike protein-encoded mRNA vaccine model, mRNA-LNPs made from either C8-Ceramide-PEG or C16-Ceramide-PEG yielded comparable vaccination efficacy to mRNA-LNPs made from ALC-0159, while mRNA-LNPs formulated with DSPE-PEG with C18 lipid tails mediated lower vaccination efficacy. C16-Ceramide-PEG LNPs and DSPE-PEG LNPs induced higher anti-PEG antibody response than C8-Ceramide-PEG and ALC-0159 LNPs. All the LNPs tested did not cause significant toxicity in mice. These results offer valuable insights into the use of PEG-lipid in LNP formulations and suggest that C8-Ceramide-PEG holds potential for use in the formulation of mRNA vaccine-loaded LNPs.

Cutting-edge biotherapeutics and advanced delivery strategies for the treatment of metabolic dysfunction-associated steatotic liver disease spectrum

Metabolic dysfunction-associated steatotic liver disease (MASLD), a condition with the potential to progress into liver cirrhosis or hepatocellular carcinoma, has become a significant global health concern due to its increasing prevalence alongside obesity and metabolic syndrome. Despite the promise of existing therapies such as thyroid hormone receptor-β (THR-β) agonists, PPAR agonists, FXR agonists, and GLP-1 receptor agonists, their effectiveness is limited by the complexity of the metabolic, inflammatory, and fibrotic pathways that drive MASLD progression, encompassing steatosis, metabolic dysfunction-associated steatohepatitis (MASH), and reversible liver fibrosis. Recent advances in targeted therapeutics, including RNA interference (RNAi), mRNA-based gene therapies, monoclonal antibodies, proteolysis-targeting chimeras (PROTAC), peptide-based strategies, cell-based therapies such as CAR-modified immune cells and stem cells, and extracellular vesicle-based approaches, have emerged as promising interventions. Alongside these developments, innovative drug delivery systems are being actively researched to enhance the stability, precision, and therapeutic efficacy of these biotherapeutics. These delivery strategies aim to optimize biodistribution, improve target-specific action, and reduce systemic exposure, thus addressing critical limitations of existing treatment modalities. This review provides a comprehensive exploration of the underlying biological mechanisms of MASLD and evaluates the potential of these cutting-edge biotherapeutics in synergy with advanced delivery approaches to address unmet clinical needs. By integrating fundamental disease biology with translational advancements, it aims to highlight future directions for the development of effective, targeted treatments for MASLD and its associated complications.

Metabolic Stability and Targeted Delivery of Oligonucleotides: Advancing RNA Therapeutics Beyond The Liver

Oligonucleotides have emerged as a formidable new class of nucleic acid therapeutics. Fully modified oligonucleotides exhibit enhanced metabolic stability and display successful clinical applicability for targets formerly considered "undruggable". Accumulating studies show that conjugation to targeting modalities of stabilized oligonucleotides, especially small interfering RNAs (siRNAs), has enabled robust delivery to intended cells/tissues. However, the major challenge in the field has been the stability and targeted delivery of oligonucleotides (siRNAs and antisense oligonucleotides (ASOs)) to extrahepatic tissues. In this Perspective, we review chemistry innovations and emerging delivery approaches that have revolutionized oligonucleotide drug discovery and development. We explore findings from both academia and industry that highlight the potential of oligonucleotides for indications involving different extrahepatic organs─including skeletal muscles, brain, lungs, skin, heart, adipose tissue, and eyes. In all, continued advances in chemistry coupled with conjugation-based approaches or novel administration routes will further advance the delivery of oligonucleotides to extrahepatic tissues.

Lipid Nanoparticles and PEG: Time Frame of Immune Checkpoint Blockade Can Be Controlled by Adjusting the Rate of Cellular Uptake of Nanoparticles

The engineerability of lipid nanoparticles (LNPs) and their ability to deliver nucleic acids make LNPs attractive tools for cancer immunotherapy. LNP-based gene delivery can be employed for various approaches in cancer immunotherapy, including encoding tumor-associated antigens and silencing of negative immune checkpoint proteins. For example, LNPs carrying small interfering RNAs can offer several advantages, including sustained and durable inhibition of an immune checkpoint protein. Due to their tunable design, modifying the lipid composition of LNPs can regulate the rate of their uptake by immune cells and the rate of gene silencing. Controlling the kinetics of LNP uptake provides additional flexibility and strategies to generate appropriate immunomodulation in the tumor microenvironment. Here, we evaluated the effects of polyethylene glycol (PEG) content ranging from 0.5 to 6 mol % on the cellular uptake of LNPs by immune cells and gene silencing of PD-L1 after intratumoral administration. We evaluated the cellular uptake and PD-L1 blockade in vitro in cell studies and in vivo using the YUMM1.7 melanoma tumor model. Cell studies showed that the rate of cell uptake was inversely correlated to an increasing mol % of PEG in a linear relationship. In the in vivo studies, 0.5% PEG LNP initiated an immediate effect in the tumor with a significant decrease in the PD-L1 expression of immune cells observed within 24 h. In comparison, the gene silencing effect of 6% PEG LNP was delayed, with a significant decrease of PD-L1 expression in immune cell subsets being observed 72 h after administration. Notably, performance of the 6% PEG LNP at 72 h was comparable to that of the 0.5% PEG LNP at 24 h. Overall, this study suggests that PEG modifications and intratumoral administration of LNPs can be a promising strategy for an effective antitumor immune response.

Regulating mRNA endosomal escape through lipid rafts: A review

Messenger RNA (mRNA) therapeutics, enabled by lipid nanoparticles (LNPs) delivery systems, have revolutionized modern medicine by facilitating the delivery of genetic cargo to target cells. However, the efficient release of mRNA from LNPs within the endosomal pathways into the cytosol remains a major bottleneck in this field. Revisiting the formulation and function of mRNA-LNPs, it has been found that lipid rafts formed by cholesterol and distearoylphosphatidylcholine during the self-assembly process plan an essential role in the intracellular delivery and endosomal escape of mRNA-LNPs. These lipid rafts enhance the rigidity and stability of LNPs, facilitating mRNA encapsulation and closely contributing to improved intracellular delivery efficiency. By adjusting the composition or behavior of lipid rafts within LNPs-such as substituting cholesterol or altering the lipid phase-endosomal membranes can be destabilized, facilitating the escape of mRNA into the cytoplasm. This approach provides a promising strategy for rational design of mRNA delivery system and optimization of LNPs formulation. Additionally, methods for studying the mRNA escape process are summarized, as they serve as the foundation for achieving reliable and reproducible results.

The Fomivirsen, Patisiran, and Givosiran Odyssey: How the Success Stories May Pave the Way for Future Clinical Translation of Nucleic Acid Drugs

Over the past 25 years, the approval of several nucleic acid-based drugs by the US Food and Drug Administration (FDA) has marked a significant milestone, establishing nucleic acid drugs as a viable therapeutic modality. These groundbreaking discoveries are the result of some crucial points in the timeline of nucleic acid drug development. The inventions used in fomivirsen (Vitravene; Isis Pharmaceuticals) development paved the road for structural backbone modifications as well as nucleobase and sugar modifications. The approval of patisiran (Onpattro; Alnylam) demonstrated an effective and safe delivery system for small interfering RNA (siRNA), extending potential applications to other nucleic acids such as messenger RNA (mRNA). Givosiran (Givlaari; Alnylam) further revolutionized the field with a carrier-free, targeted platform, utilizing N-Acetylgalactosamine (GalNAc)-siRNA conjugates to enable efficient delivery, expanding therapeutic applications beyond rare genetic disorders to more common conditions such as hyperlipidemia and hypertension. In this review paper, we highlight the evolution of nucleic acid-based drug development, focusing on the pioneering agents fomivirsen, patisiran, and givosiran, and discuss the ongoing challenges in advancing these therapeutics and vaccines.

Incorporation of cellular membrane protein extracts into lipid nanoparticles enhances their cellular uptake and mRNA delivery efficiency

mRNA therapeutics enable transient expression of desired proteins within cells, holding great potential for advancements in vaccines, protein replacement therapies and gene editing approaches. Lipid nanoparticles (LNPs) are arguably the leading nanoplatform for mRNA delivery due to their scalability and transfection efficiency. However, their limited ability to target specific cell types, inefficient cellular uptake by many cell types, and endosomal entrapment represent challenges for improving targeted mRNA delivery. To address this, we evaluated a novel class of LNPs functionalized with cell-derived membrane proteins, that we refer to as hybrisomes. Membrane protein extracts (MPEs) were isolated from cultured cells using a mild detergent-based extraction protocol. Cy5-labeled mRNA encoding for eGFP was used to form LNPs and hybrisomes to investigate their internalization efficiency and mRNA delivery via flow cytometry and microscopy, with MPE content incorporated into hybrisomes during microfluidic mixing. MPEs were successfully incorporated into the lipid membrane of hybrisomes. Remarkably, the cellular uptake of hybrisomes was up to 15-fold higher than LNPs, while the mRNA delivery efficiency improved up to 8-fold depending on the MPE content incorporated into the hybrisomes. Further studies confirmed that the enhanced cellular uptake of hybrisomes and mRNA is partially explained by the presence of membrane proteins and hybrisomes' unique morphology including bleb-like structures. Moreover, the versatility of hybrisomes was demonstrated by producing formulations using MPEs isolated from different cell types, which led to variations in cellular uptake and mRNA delivery, suggesting that the cell type from which MPEs are derived influences their biological function. These findings pave the way for the development of more targeted and effective nanotherapeutic strategies.

Placental targeted drug delivery: a review of recent progress

The placenta plays a crucial role in mediating nutrient and gas exchange between the mother and fetus during pregnancy. Targeting therapeutic agents to the placenta presents significant opportunities for treating placental disorders and enhancing fetal outcomes. However, the unique structural complexity and selective permeability of the placenta pose substantial challenges for effective drug delivery. This review provides a comprehensive overview of current strategies for placental targeting, including lipid nanoparticle (LNP) delivery systems, targeted peptide modifications, specific antibody targeting of placental receptors, and the use of viral vectors. We critically analyze the advantages and limitations of each approach, emphasizing recent advancements in enhancing targeting specificity and delivery efficiency. By consolidating the latest research developments, this review aims to foster further innovation in placental drug delivery methods and contribute significantly to the advancement of therapeutic strategies for placental disorders, ultimately improving outcomes for both mother and fetus.

Macrophage-targeted Mms6 mRNA-lipid nanoparticles promote locomotor functional recovery after traumatic spinal cord injury in mice

Traumatic spinal cord injury (SCI) causes severe central nervous system damage. M2 macrophages within the lesion are crucial for SCI recovery. Our previous research revealed that M2 macrophages transfected with magnetotactic bacteria-derived Mms6 gene can resist ferroptosis and enhance SCI recovery. To address the limitations of M2 macrophage transplantation, we developed lipid nanoparticles (LNPs) encapsulating Mms6 mRNA targeting macrophages (Mms6 mRNA-PS/LNPs). The targeting efficiency and therapeutic effect of these LNPs in SCI mice were evaluated. Intravenous administration of Mms6 mRNA-PS/LNPs delivered more Mms6 mRNAs to lesion-site macrophages than those in the Mms6 mRNA-LNP group, which resulted in enhancing motor function recovery, reducing lesion area and scar formation, and promoting neuronal survival and nerve fiber repair. These effects were nullified when macrophages were depleted. These findings suggest that macrophage-targeted delivery of Mms6 mRNA is a promising therapeutic strategy for promoting spinal cord repair and motor function recovery in patients with traumatic SCI.

Autonomic lysosomal escape via sialic acid modification enhances mRNA lipid nanoparticles to eradicate tumors and build humoral immune memory

Lysosomes present a major barrier to efficient mRNA delivery. Existing strategies primarily depend on lysosomal disruption, which is inefficient and carries a risk of cytolysis. We propose an Autonomic Lysosomal Escape (ALE) strategy, in which sialic acid (SA) modification enables over 90 % of LNPs to successfully escape from lysosomes by inducing cells to spontaneously reduce lysosome generation. The SA modification enhances the transfection efficiency of LNPs administered via intravenous injection, intramuscular injection, and inhalation, demonstrating the broad applicability. The structure of cleavable PEG-lipids was optimized using a newly developed method, termed Systematic Evaluation of LNPs' Efficiency by Cumulative Tests (SELECT). The results showed that polyethylene glycol 2000-cholesterol hemisuccinate (Ps) is the optimal candidate for co-modification with SA. The resulting LNPs co-modified with SA and Ps (SAPs@LNPs) completely eradicated TC-1 tumors and induced humoral immune memory. Combining SA-modified doxorubicin liposomes (DOX-SL) further accelerates tumor elimination, while licensed PEGylated liposomal doxorubicin (Caelyx) impairs the efficacy of mRNA vaccines. This difference stems from DOX-SL's selective depletion of tumor-associated immune cells (TAICs) and the nonspecific cytotoxicity of Caelyx. These findings suggest that combining Caelyx with mRNA vaccines should be approached with caution. Our study also highlights the key roles of humoral immune memory and natural killer cell-driven antibody-dependent cellular cytotoxicity (ADCC) in tumor eradication, and incorporating them into the cancer immune cycle further refines this theory.

Bioactivity and biomedical applications of pomegranate peel extract: a comprehensive review

Pomegranate peel is a by-product generated during the processing of pomegranate (Punica granatum L.) fruit, accounting for approximately 50% of the total mass of the fruit. Although pomegranate peel is usually regarded as waste, it is rich in various bioactive metabolites such as polyphenols, tannins, and flavonoids, demonstrating significant medicinal and nutritional value. In recent years, Pomegranate peel extract (PPE) has shown broad application prospects in the biomedical field due to its multiple effects, including antioxidant, anti-inflammatory, antibacterial, anti-apoptotic properties, and promotion of cell regeneration. This review consolidates the major bioactive metabolites of PPE and explores its applications in biomedical materials, including nanodrug carriers, hydrogels, and tissue engineering scaffolds. By synthesizing the existing literature, we delve into the potential value of PPE in biomedicine, the challenges currently encountered, and the future directions for research. The aim of this review is to provide a scientific basis for optimizing the utilization of PPE and to facilitate its broader application in the biomedical field.

Probing the Role of Lipid Nanoparticle Elasticity on mRNA Delivery to the Placenta

It is well established that the physicochemical properties of lipid nanoparticles (LNPs) can govern their interactions with various biological barriers. One property hypothesized to influence nanoparticle-cell interactions is elasticity. Here, we formulate LNPs with naturally occurring cholesterol analogs to tune LNP elasticity and study its role on mRNA delivery to the placenta. LNP elasticity was measured via atomic force microscopy where these LNPs exhibited Young's moduli ranging from 71.0 ± 26.2 to 411.4 ± 145.7 kPa. In vitro screening of these LNPs in placental trophoblasts showed that stiffer LNPs improved LNP uptake and mRNA delivery compared with softer LNPs. Following intravenous administration to pregnant mice, the stiffer LNPs incorporating β-sitosterol enhanced placental and reduced liver mRNA delivery compared with softer LNPs containing only cholesterol. These results demonstrate the ability of stiffer LNPs to promote placental mRNA delivery and highlight the potential of tuning LNP elasticity to improve LNP-mediated mRNA delivery to organs of interest.

Adipose progenitor cell-derived extracellular vesicles suppress macrophage M1 program to alleviate midlife obesity

Among different age groups, middle-aged individuals are particularly susceptible to obesity, with a 22% higher risk of all-cause mortality. However, the underlying mechanisms remain unclear. In this study, we identify adipose progenitor cells (APCs) in the white adipose tissue (WAT) of middle-aged subjects as potential causes of midlife obesity. Specifically, the extracellular vesicles (EVs) derived from APCs display an impaired ability to mitigate the inflammaging of adipose tissue macrophages (ATMs) in middle-aged individuals. Mechanistically, these EVs, lacking miR-145-5p, fail to suppress the expression of L-selectin in ATMs, thereby facilitating their M1 program via the NF-κB signaling pathway. In contrast, EVs from young APCs effectively inhibit M1 macrophage polarization. Accordingly, targeted liposomes are designed to deliver miR-145-5p mimics to ATMs, which effectively prevent the obesity in middle-aged mice. Collectively, our findings highlight the role of APC-derived EVs in midlife obesity and propose miR-145-5pas a promising therapeutic target for clinical applications.

Tailoring Lipid Nanoparticle with Ex Situ Incorporated Conjugated Oligoelectrolyte for Enhanced mRNA Delivery Efficiency

Developing new lipid nanoparticle (LNP) formulations typically involves reconstruction from separate elements followed by rigorous purification steps, contributing to drawn-out drug discovery processes. Membrane-intercalating conjugated oligoelectrolytes (COEs) are water-soluble molecules featuring a conjugated backbone and peripheral ionic groups, specifically designed to spontaneously integrate into lipid bilayers. Herein, an ex situ strategy to "dope" the representative COE-S6 into pre-formed messenger RNA-LNPs (mRNA-LNPs) is presented, exploiting its spontaneous membrane intercalation property through a straightforward add-and-mix procedure. Incorporating 0.2% COE-S6 into mRNA-LNPs relative to lipid content reduced particle size from 84.5 ± 1 to 67.9 ± 0.8 nm, elevated cellular uptake, and improved endosomal escape. These traits culminate in an increase in in cellula transfection from 24.2 ± 1.6% to 98.7 ± 0.6%. When injected intravenously into healthy BALB/c mice, the optimized COE-S6-doped mRNA-LNPs boost in vivo luciferase expression by 1.75-fold. Additionally, COE-S6-doped mRNA-LNPs exhibit fluorogenic properties, enabling intracellular mechanistic studies via confocal microscopy. This simple method enhances the properties of mRNA-LNPs with minimal COE quantities, offering a novel strategy to improve existing LNP formulations and provide optical reporting capabilities, essential for expediting drug discovery and delivery.

Targeting Neuroinflammation in Central Nervous System Diseases by Oral Delivery of Lipid Nanoparticles

Neuroinflammation within the central nervous system (CNS) is a primary characteristic of CNS diseases, such as Parkinson's disease, Alzheimer's disease (AD), amyotrophic lateral sclerosis, and mental disorders. The excessive activation of immune cells results in the massive release of pro-inflammatory cytokines, which subsequently induce neuronal death and accelerate the progression of neurodegeneration. Therefore, mitigating excessive neuroinflammation has emerged as a promising strategy for the treatment of CNS diseases. Despite advancements in drug discovery and the development of novel therapeutics, the effective delivery of these agents to the CNS remains a serious challenge due to the restrictive nature of the blood-brain barrier (BBB). This underscores the need to develop a novel drug delivery system. Recent studies have identified oral lipid nanoparticles (LNPs) as a promising approach to efficiently deliver drugs across the BBB and treat neurological diseases. This review aims to comprehensively summarize the recent advancements in the development of LNPs designed for the controlled delivery and therapeutic modulation of CNS diseases through oral administration. Furthermore, this review addresses the mechanisms by which these LNPs overcome biological barriers and evaluate their clinical implications and therapeutic efficacy in the context of oral drug delivery systems. Specifically, it focuses on LNP formulations that facilitate oral administration, exploring their potential to enhance bioavailability, improve targeting precision, and alleviate or manage the symptoms associated with a range of CNS diseases.

Hurdles to healing: Overcoming cellular barriers for viral and nonviral gene therapy

Gene delivery offers great potential for treating various diseases, yet its success requires overcoming several biological barriers. These hurdles span from extracellular degradation, reaching the target cells, and inefficient cellular uptake to endosomal entrapment, cytoplasmic transport, nuclear entry, and transcription limitations. Viruses and non-viral vectors deal with these barriers via different mechanisms. Viral vectors, such as adenoviruses, adeno-associated viruses, and lentiviruses use natural mechanisms to efficiently deliver genetic material but face limitations including immunogenicity, cargo capacity, and production complexity. Nonviral vectors, including lipid nanoparticles, polymers, and protein-based systems, offer scalable and safer alternatives but often fall short in overcoming intracellular barriers and achieving high transfection efficiencies. Recent advancements in vector engineering have partially overcome several of these challenges. Ionizable lipids improve endosomal escape while minimizing toxicity. Biodegradable polymers balance efficacy with safety, and engineered protein systems, inspired by viral or bacterial entry mechanisms, integrate multifunctionality for enhanced delivery. Despite these advances, challenges, particularly in achieving robust in vivo translatability, scalability, and reduced immunogenicity, remain. This review synthesizes current knowledge of cellular barriers and the approaches to overcome them, providing a roadmap for designing more efficient gene delivery systems. By addressing these barriers, the field can advance toward safer, and more effective therapies.

The immunogenic potential of an optimized mRNA lipid nanoparticle formulation carrying sequences from virus and protozoan antigens

BACKGROUND

Lipid nanoparticles (LNP) are a safe and effective messenger RNA (mRNA) delivery system for vaccine applications, as shown by the COVID-19 mRNA vaccines. One of the main challenges faced during the development of these vaccines is the production of new and versatile LNP formulations capable of efficient encapsulation and delivery to cells in vivo. This study aimed to develop a new mRNA vaccine formulation that could potentially be used against existing diseases as well as those caused by pathogens that emerge every year.

RESULTS

Using firefly luciferase (Luc) as a reporter mRNA, we evaluated the physical-chemical properties, stability, and biodistribution of an LNP-mRNA formulation produced using a novel lipid composition and a microfluidic organic-aqueous precipitation method. Using mRNAs encoding a dengue virus or a Leishmania infantum antigen, we evaluated the immunogenicity of LNP-mRNA formulations and compared them with the immunization with the corresponding recombinant protein or plasmid-encoded antigens. For all tested LNP-mRNAs, mRNA encapsulation efficiency was higher than 85%, their diameter was around 100 nm, and their polydispersity index was less than 0.3. Following an intramuscular injection of 10 µg of the LNP-Luc formulation in mice, we detected luciferase activity in the injection site, as well as in the liver and spleen, as early as 6 h post-administration. LNPs containing mRNA encoding virus and parasite antigens were highly immunogenic, as shown by levels of antigen-specific IgG antibody as well as IFN-γ production by splenocytes of immunized animals that were similar to the levels that resulted from immunization with the corresponding recombinant protein or plasmid DNA.

CONCLUSIONS

Altogether, these results indicate that these novel LNP-mRNA formulations are highly immunogenic and may be used as novel vaccine candidates for different infectious diseases.

Lipid Nanoparticles for mRNA Delivery in Cancer Immunotherapy

Cancer immunotherapy is poised to be one of the major modalities for cancer treatment. Messenger RNA (mRNA) has emerged as a versatile and promising platform for the development of effective cancer immunotherapy. Delivery systems for mRNA therapeutics are pivotal for their optimal therapeutic efficacy and minimal adverse side effects. Lipid nanoparticles (LNPs) have demonstrated a great success for mRNA delivery. Numerous LNPs have been designed and optimized to enhance mRNA stability, facilitate transfection, and ensure intracellular delivery for subsequent processing. Nevertheless, challenges remain to, for example, improve the efficiency of endosomal escape and passive targeting. This review highlights key advancements in the development of mRNA LNPs for cancer immunotherapy. We delve into the design of LNPs for mRNA delivery, encompassing the chemical structures, characterization, and structure-activity relationships (SAR) of LNP compositions. We discuss the key factors influencing the transfection efficiency, passive targeting, and tropism of mRNA-loaded LNPs. We also review the preclinical and clinical applications of mRNA LNPs in cancer immunotherapy. This review can enhance our understanding in the design and application of LNPs for mRNA delivery in cancer immunotherapy.

Development of a messenger RNA vaccine using pH-responsive dipeptide-conjugated lipids exhibiting reduced inflammatory properties

Lipid nanoparticles (LNPs) are used to encapsulate messenger ribonucleic acids (mRNAs) and enhance mRNA vaccine efficacy by producing inflammatory mediators. However, the overproduction of inflammatory mediators via LNP injection causes severe side effects, presenting a potential limitation. To resolve this issue, we developed pH-responsive dipeptide-conjugated lipid (DPL)-based LNPs (DPL-LNPs) for efficient small interfering RNA delivery with excellent biocompatibility. In detail, we optimized the dipeptide sequence and lipid-tail length of DPL, the helper-lipid compositions, and the molecular weight and lipid-tail length of the polyethylene glycol (PEG)-lipid to achieve highly efficient and safe mRNA delivery. Our results revealed that the LNPs prepared using glutamic acid (E)- and arginine (R)-conjugated DPL (DPL-ER) displayed higher protein-expression efficacy than DPL-threonine-R- and DPL-aspartic acid-R-based LNPs. Additionally, the lipid-tail length of the C22-bearing DPL-ER (DPL-ER-C22)-based LNPs displayed higher protein-expression efficacies than their C18 (DPL-ER-C18)- and C24 (DPL-ER-C24)-based LNPs. Moreover, the DPL-ER-C22-based LNPs incorporating low-lipid-tail-length phospholipids and PEG-lipids exhibited efficient protein expression. Most importantly, the injection of optimized DPL-LNPs exhibited comparable antigen-specific antibody production levels, with significantly lower inflammatory-mediator production compared with those of the commercially available LNPs. These results indicate that DPL-based LNPs (DPL-LNPs) can be deployed as highly efficient, safe carriers for mRNA delivery for developing mRNA vaccine formulations.

Cationic liposomes as broad-spectrum antidotes for heparin-based anticoagulants

Heparin-based anticoagulants have been widely used for the prevention and treatment of venous thrombotic diseases, as well as for anticoagulation during cardiopulmonary bypass and hemodialysis. However, excessive heparin usage brings serious bleeding risk, necessitating immediate reversal of their anticoagulant activity. Additionally, to prevent bleeding during surgery and restore hemostatic function post-cardiopulmonary bypass and hemodialysis, it is also crucial to reverse heparin's anticoagulant effects. Currently, protamine sulfate (PS) is the only clinically approved antidote for heparin. However, its effectiveness against low molecular weight heparin (LMWH) and fondaparinux sodium is limited. Moreover, PS has great potential to trigger fatal allergic reactions. Despite these concerns, no successful clinical substitutes for PS have been developed. In the current work, drawing inspiration from the mechanism by which PS efficiently reverses heparin, we modified the cationic liposome with cationic amino acids, arginine and lysine, to serve as a broad-spectrum antidote (CRKRK-Lipo) for heparin-based anticoagulants. This modification not only enhances their reversal efficiency but also reduces the overall surface charge, potentially improving their biocompatibility. In the tail bleeding and liver injury mouse models, CRKRK-Lipo demonstrated reversal efficiency comparable to PS for heparin and superior reversal efficiency for LMWH and fondaparinux sodium. Notably, CRKRK-Lipo exhibited a wider therapeutic dose window and did not exhibit severe cytotoxicity or immunogenicity, in contrast to PS. It is worth noting that cationic liposomes without polypeptide modification also displayed a significant heparin reversal effect. Our findings not only offer a potential alternative for PS but also broaden the application fields of cationic liposome. STATEMENT OF SIGNIFICANCE: This study introduces the cationic liposomes as a novel and effective alternative to protamine sulfate (PS) for the functional reversal of heparin-based anticoagulants. The results reveal that both CRKRK-modified cationic liposomes (CRKRK-Lipo) and unmodified cationic liposomes (Lipo) showed comparable reversal efficiency to PS for UFH and superior reversal efficiency for LMWH and fondaparinux sodium, with a wider therapeutic dose window and reduced toxicity. This work offers an alternative strategy for detoxifying heparin-based anticoagulants and expands the biomedical applications of cationic liposomes.

Optimizing Peptide-Conjugated Lipid Nanoparticles for Efficient siRNA Delivery across the Blood-Brain Barrier and Treatment of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is a WHO grade 4 glioma and the most common malignant primary brain tumor. Addressing the clinical management of GBM presents an exceptionally daunting and intricate challenge, particularly in overcoming the blood-brain barrier (BBB) to deliver effective therapies to the brain. Nanotechnology-based drug delivery systems have exhibited considerable promise in tackling this aggressive brain cancer. However, the BBB remains a key challenge in achieving effective brain delivery of nanocarriers. Here, we have optimized a lipid nanoparticle (LNP) formulation (C2) and modified the LNP with Angiopep-2 peptide, which exhibits the most significant improvements in blood-brain barrier penetration and brain accumulation (about 2.23% injection dose). Using the Ang-2-coupled C2 LNP formulation, we researched the therapeutic effect of Polo-like Kinase 1(PLK1)-targeted siRNA delivery to treat a mouse model of GBM. The optimized LNP formulation was demonstrated to significantly inhibit mouse GBM growth and extend the median survival of mice (2.18-fold). This work demonstrates the efficacy of a brain-targeted siRNA delivery system in GBM treatment. As the understanding of the role of RNAs in GBM deepens and innovative delivery methods are continually developed and refined, RNA-based therapies could emerge as a crucial breakthrough in the advancement of brain tumor treatment.

Rapidly separable bubble microneedle-patch system present superior transdermal mRNA delivery efficiency

Traditional mRNA vaccine formulation loaded by lipid nanoparticle (mRNA-LNP) has several shortcomings in clinical application, including the need for cryopreservation, discomfort associated with intramuscular injections, and the risk of liver aggregation. Dissolvable microneedles (DMNs), as a novel transdermal drug delivery platform, can overcome the skin barrier to deliver drugs directly into the skin in a minimally invasive manner. However, mRNA-LNP is unstable and easily degraded during the solidification of DMN. In this study, we proposed to establish a rapidly dissolvable bubble microneedle patch (bMNP) system for the transdermal delivery of mRNA-LNP. We explored to use polyvinyl alcohol (PVA) and trehalose for the first time as matrix material for preparing microneedles. Our results demonstrate that the stability of the mRNA-LNP was obviously improved. The mRNA in this bMNP system can be stored at room temperature for at least one month. Furthermore, the existence of air bubbles between the needle tip and the dorsal scale of bMNP can achieve dorsal scale separation by applying shear force after inserting into subcutaneous tissue, and effectively target lymph nodes in vivo after releasing mRNA-LNP. Using mRNA that encodes the spike protein from SARS-CoV-2 as a test case, the rapidly separable bMNP system induced the production of significant levels of spike-specific IgG antibodies, neutralizing antibodies, and a Th1-polarized T cell response, providing an alternative route for mRNA delivery. Our research is expected to provide a promising transdermal drug delivery strategy that can improve mRNA vaccine accessibility.

Landscape of small nucleic acid therapeutics: moving from the bench to the clinic as next-generation medicines

The ability of small nucleic acids to modulate gene expression via a range of processes has been widely explored. Compared with conventional treatments, small nucleic acid therapeutics have the potential to achieve long-lasting or even curative effects via gene editing. As a result of recent technological advances, efficient small nucleic acid delivery for therapeutic and biomedical applications has been achieved, accelerating their clinical translation. Here, we review the increasing number of small nucleic acid therapeutic classes and the most common chemical modifications and delivery platforms. We also discuss the key advances in the design, development and therapeutic application of each delivery platform. Furthermore, this review presents comprehensive profiles of currently approved small nucleic acid drugs, including 11 antisense oligonucleotides (ASOs), 2 aptamers and 6 siRNA drugs, summarizing their modifications, disease-specific mechanisms of action and delivery strategies. Other candidates whose clinical trial status has been recorded and updated are also discussed. We also consider strategic issues such as important safety considerations, novel vectors and hurdles for translating academic breakthroughs to the clinic. Small nucleic acid therapeutics have produced favorable results in clinical trials and have the potential to address previously "undruggable" targets, suggesting that they could be useful for guiding the development of additional clinical candidates.

Cyclic Poly(2-methyl-2-oxazoline)-Lipid Conjugates Are Good Alternatives to Poly(ethylene glycol)-Lipids for Lipid Nanoparticle mRNA Formulation

Lipid nanoparticles (LNPs) with ionizable cationic lipids have revolutionized RNA drug delivery, playing a key role in the success of mRNA-based therapeutics, such as COVID-19 vaccines. A vital component of these LNPs is the poly(ethylene glycol) (PEG)-lipid conjugate, which enhances colloidal stability but may trigger the production of anti-PEG antibodies, resulting in accelerated blood clearance (ABC) and diminished therapeutic efficacy. In this study, we explored poly(2-methyl-2-oxazoline) (PMOXA) as an alternative stabilizing agent for mRNA LNPs. We synthesized both cyclic and linear PMOXA, conjugated them to dialkyl lipids, and created lipid-polymer amphiphiles. We systematically evaluated how polymer topology influenced the physicochemical properties of LNPs, including in vitro cellular uptake, transfection efficiency, and protein corona formation, and directly compared these properties with those of PEG-stabilized counterparts. In vivo experiments in mice further assessed the biodistribution and protein translation efficiency of these LNPs following intravenous administration. Our results showed that cyclic PMOXA conjugates not only matched but potentially surpassed the performance of PEG-based analogues, highlighting their promise as a superior alternative in mRNA-LNP formulations.

In vivo vectorization and delivery systems for gene therapies and RNA-based therapeutics in oncology

Gene and RNA-based therapeutics represent a promising frontier in oncology, enabling targeted modulation of tumor-associated genes and proteins. This review explores the latest advances in payload vectorization and delivery systems developed for in vivo cancer treatments. We discuss viral and non-viral organic particles, including lipid based nanoparticles and polymeric structures, for the effective transport of plasmids, siRNA, and self-amplifying RNA therapeutics. Their physicochemical properties, strategies to overcome intracellular barriers, and innovations in cell-based carriers and engineered extracellular vesicles are highlighted. Moreover, we consider oncolytic viruses, novel viral capsid modifications, and approaches that refine tumor targeting and immunomodulation. Ongoing clinical trials and regulatory frameworks guide future directions and emphasize the need for safe, scalable production. The potential convergence of these systems with combination therapies paves the way toward personalized cancer medicine.

mRNA delivery with templated dynamic covalent polymers

Messenger RNA is a novel therapeutic modality which was key in curbing the Covid-19 pandemic. However, the delivery of mRNA in cells requires the development of smart vectors. We here report on amphiphilic dynamic covalent polymers formed in situ through RNA templating, and show effective nanoparticle formation and delivery of EGFP mRNA in cells.

An LNP-mRNA vaccine protects fish against rhabdovirus infection

mRNA vaccines are poised to revolutionize disease prevention, following the approval of their administration to humans against SARS-CoV-2. Although they have been extensively studied for human applications, their potential in the veterinary field has not been explored yet. No mRNA vaccines have yet been reported for fish, despite the urgent need for new vaccines against emerging pathogens in aquaculture. As fish are ectotherms, temperature has an impact on their immune response and on many other biological parameters, including the composition of membrane lipids. It is therefore crucial to identify whether mRNA delivery systems are suitable for in vivo expression in fish for vaccine purposes. In the present study, we developed a proof of concept for mRNA vaccination in rainbow trout, a salmonid, demonstrating the efficacy of current vaccine delivery systems in fish. We used lipid nanoparticles (LNPs), which represent the most advanced delivery technology for mRNA. LNPs use a combination of lipid components that form an encapsulating structure offering protection and promote endosome escape of the mRNA to allow its expression. In vitro assays showed that LNPs are a powerful vehicle for mRNA delivery in fish cells without substantial toxicity. In vivo imaging in adult zebrafish (Danio rerio) demonstrated that intramuscular injection of LNP-formulated egfp mRNA resulted in local expression of eGFP for up to 7 days. An LNP-based mRNA vaccine candidate encoding the viral haemorrhagic septicaemia virus (VHSV) glycoprotein induced neutralizing antibodies in rainbow trout (Oncorhynchus mykiss) and offers almost complete protection against a lethal viral challenge. Our data constitute a first proof of concept of mRNA vaccination in fish, paving the way for new developments in veterinary vaccines for aquaculture.

Emerging roles of noncoding RNAs in cardiovascular pathophysiology

This review comprehensively examines the diverse roles of noncoding RNAs (ncRNAs) in the pathogenesis and treatment of cardiovascular disease (CVD), focusing on microRNA (miRNA), long noncoding RNA (lncRNA), piwi-interacting RNA (piRNA), small-interfering RNA (siRNA), circular RNA (circRNA), and vesicle-associated RNAs. These ncRNAs are integral regulators of key cellular processes, including gene expression, inflammation, and fibrosis, and they hold great potential as both diagnostic biomarkers and therapeutic targets. The review highlights novel insights into how these RNA species, particularly miRNAs, lncRNAs, and piRNAs, contribute to various CVDs such as hypertension, atherosclerosis, and myocardial infarction. In addition, it explores the emerging role of extracellular vesicles (EVs) in intercellular communication and their therapeutic potential in cardiovascular health. The review underscores the need for continued research into ncRNAs and RNA-based therapies, with a focus on advancing delivery systems and expanding personalized medicine approaches to improve cardiovascular outcomes.

Engineering Lipid Nanoparticles for mRNA Immunotherapy

Over the last decades, messenger RNA (mRNA) has emerged as a promising therapeutic modality, enabling the delivery of genetic instructions to cells for producing therapeutic proteins or antigens. As such, mRNA-based therapies can be developed for a wide range of conditions, including infections, cancer, metabolic disorders, and genetic diseases. Nevertheless, using mRNA therapeutically requires chemical modifications to reduce immunostimulatory effects and nanotechnology to prevent degradation and ensure intracellular delivery. Lipid nanoparticles (LNPs) have become the most effective delivery platform for mRNA therapeutics, which are primarily employed for vaccine purposes following local administration and hepatic applications following systemic administration. Here, we review the state-of-the-art LNP-mRNA technology and discuss its potential for immunotherapy. We first outline the requirements for mRNA to be used therapeutically, including the role of LNP-mediated delivery. Next, we highlight LNP-mRNA immunotherapy approaches for vaccination, immuno-oncology, and autoimmune disorders. In addition, we discuss challenges that are limiting LNP-mRNA's widespread use, including tunable biodistribution and immunostimulatory effects. Finally, we provide an outlook on how implementing approaches such as library screening and machine learning will guide the development of next-generation mRNA therapeutics.

Exploring the immuno-nano nexus: A paradigm shift in tumor vaccines

Tumor vaccines have become a crucial strategy in cancer immunotherapy. Challenges of traditional tumor vaccines include inadequate immune activation and low efficacy of antigen delivery. Nanoparticles, with their tunable properties and versatile functionalities, have redefined the landscape of tumor vaccine design. In this review, we outline the multifaceted roles of nanoparticles in tumor vaccines, ranging from their capacity as delivery vehicles to their function as immunomodulatory adjuvants capable of stimulating anti-tumor immunity. We discuss how this innovative approach significantly boosts antigen presentation by leveraging tailored nanoparticles that facilitate efficient uptake by antigen-presenting cells. These nanoparticles have been meticulously designed to overcome biological barriers, ensuring optimal delivery to lymph nodes and effective interaction with the immune system. Overall, this review highlights the transformative power of nanotechnology in redefining the principles of tumor vaccines. The intent is to inform more efficacious and precise cancer immunotherapies. The integration of these advanced nanotechnological strategies should unlock new frontiers in tumor vaccine development, enhancing their potential to elicit robust and durable anti-tumor immunity.

The analysis of neutron reflectivity from Langmuir monolayers of lipids using molecular dynamics simulations: the role of lipid area

Biomolecular simulations are increasingly being used to generate detailed structural models to aid interpretation of neutron reflectometry (NR) data obtained from model biological membranes. Unlike globular systems, often studied by small-angle scattering, simulations of two-dimensional layers are sensitive to the simulation cell used which constrains the system laterally. We perform a careful analysis of NR data obtained from a monolayer of the lipid distearoylphosphatidylcholine at the air-water interface and show that the fit of number density profiles obtained from atomistic molecular dynamics simulation to the experimental data is very sensitive to the assumed area per lipid (APL). We propose a protocol for obtaining a realistic isotherm by combining the experimental surface pressure corresponding to a reflectometry measurement with an APL obtained from the simulation that best fits that data. Finally, we demonstrate how downstream interpretation of the experimental sample, derived from structural and dynamic properties of the atomistic model, depends strongly on the correct choice of simulation cell.

CD47 Knock-Out Using CRISPR-Cas9 RNA Lipid Nanocarriers Results in Reduced Mesenchymal Glioblastoma Growth In Vivo

Immune checkpoint (ICP) blockade has shown limited effectiveness in glioblastoma (GBM), particularly in the mesenchymal subtype, where interactions between immune cells and glioblastoma cancer stem cells (GSCs) drive immunosuppression and therapy resistance. Tailoring ICPs specific to GSCs can enhance the antitumor immune response. This study proposes the use of lipid nanoparticles (LNPs) encapsulating CRISPR RNAs as an in vivo screening tool for ICPs in a syngeneic model of mesenchymal GSCs. Using PD-L1 and CD47 to validate the proof of concept, intratumoral administration of LNPs in orthotopic tumors achieved efficient editing of ICPs, leading to enhanced immune cell infiltration within the tumor microenvironment. Targeting CD47 reduced tumor growth, suggesting improved cancer cell sensitization to the immune system post-ICP editing. The study positions LNPs as a robust tool for in vivo validation of ICPs as therapeutic targets in clinically relevant GBM models. LNPs could serve as a screening tool in patient-derived xenografts to identify and optimize ICP combinations, potentially expediting ICP translation and enhancing personalized GBM immunotherapies.

Chemistry, manufacturing and controls strategies for using novel excipients in lipid nanoparticles

Lipid nanoparticles (LNPs) for nucleic acid delivery often use novel lipids as functional excipients to modulate the biodistribution, pharmacokinetics, pharmacodynamics and efficacy of the nucleic acid. Novel excipients used in pharmaceutical products are subject to heightened regulatory scrutiny and often require data packages comparable to an active pharmaceutical ingredient. Although these regulatory requirements may help to ensure patient safety they also create economic and procedural barriers that can disincentivize innovation and delay clinical investigation. Despite the unique structural and functional role of lipid excipients in LNPs, there is limited specific global regulatory guidance, which adds uncertainty and risk to the development of LNPs. In this Perspective we provide an industry view on the chemistry, manufacturing and controls challenges that pharmaceutical companies face in the use of novel lipid excipients at each stage of development, and propose consensus recommendations on how to streamline and clarify development and regulatory expectations.

Muco-Penetrating Lipid Nanoparticles Having a Liquid Core for Enhanced Intranasal mRNA Delivery

Intranasal delivery of mRNA vaccines offers promising opportunities to combat airborne viruses like SARS-CoV-2 by provoking mucosal immunity, which not only defends against respiratory infection but also prevents contagious transmission. However, the development of nasal mRNA vaccines has been hampered by the lack of effective means to overcome the mucus barrier. Herein, ionizable lipid-incorporated liquid lipid nanoparticles (iLLNs) capable of delivering mRNA cargo across airway mucosa are designed. Adjusting the ratios of ionizable and cationic lipids allows fine-tuning of the pKa of iLLNs to the range of nasal mucosal pH (5.5-6.5), thus facilitating mucus penetration via the formation of near-neutral, PEGylated muco-inert surfaces. When nasally administered to mice, the top candidate iLLN-2/mRNA complexes enable about 60-fold greater reporter gene expression in the nasal cavity, compared to the benchmark mRNA-lipid nanoparticles (ALC-LNP) having the same lipid composition as that of BNT162b2 vaccine. Moreover, a prime-boost intranasal immunization of iLLN-2/mRNA complexes elicits a greater magnitude of SARS-CoV-2 spike-specific mucosal IgA and IgG response than ALC-LNP, without triggering any noticeable inflammatory reactions. Taken together, these results provide useful insights for the design of nasally deliverable mRNA formulations for prophylactic applications.

Fenugreek seeds as a natural source of L-arginine-encapsulated lipid nanoparticles against diabetes

Diabetes, affecting over 10.5% of the global population, leads to severe health complications and economic burdens, highlighting the urgent need for effective therapeutic approaches. Current treatments are often insufficient, prompting the exploration of novel therapeutic agents and delivery mechanisms. This study addresses this gap by investigating the roles of L-arginine (identified as a target drug candidate through network pharmacology) in diabetes management, while also evaluating lipid nanocarriers synthesized from fenugreek seed oil for improved drug delivery. Our docking analyses revealed L-arginine's strong interactions with diabetes-target genes (CYP1A2, CYP2C19, and NFKB), with multiple hydrogen bonds and binding energies ranging from - 7.2 to - 8.9 kcal/mol. Encapsulated L-arginine lipid nanoparticles were characterized using UV-Visible spectroscopy, showing absorbance peaks at 415 nm for simple nanoparticles and 521 nm for L-arginine-loaded nanoparticles. Scanning electron microscopy confirmed an average nanoparticle size of 100.2 nm, and zeta potential analysis indicated a neutral surface charge (- 9.37 mV). Antioxidative activity showed 84.44% inhibition with an IC50 value of 40.5 µg/mL The nanoparticles inhibited albumin denaturation by 81.10% and alpha-amylase by 89.30%, surpassing metformin (78.43% at 1000 µg/mL). Hemolysis percentage was minimal at 10.54%. These findings demonstrate the potential of L-arginine as an anti-diabetic agent and highlight the efficacy of lipid nanocarriers as innovative drug delivery systems, providing a foundation for advancing therapeutic interventions against diabetes.

Targeted delivery systems of siRNA based on ionizable lipid nanoparticles and cationic polymer vectors

As an emerging therapeutic tool, small interfering RNA (siRNA) had the capability to down-regulate nearly all human mRNAs via sequence-specific gene silencing. Numerous studies have demonstrated the substantial potential of siRNA in the treatment of broad classes of diseases. With the discovery and development of various delivery systems and chemical modifications, six siRNA-based drugs have been approved by 2024. The utilization of siRNA-based therapeutics has significantly propelled efforts to combat a wide array of previously incurable diseases and advanced at a rapid pace, particularly with the help of potent targeted delivery systems. Despite encountering several extracellular and intracellular challenges, the efficiency of siRNA delivery has been gradually enhanced. Currently, targeted strategies aimed at improving potency and reducing toxicity played a crucial role in the druggability of siRNA. This review focused on recent advancements on ionizable lipid nanoparticles (LNPs) and cationic polymer (CP) vectors applied for targeted siRNA delivery. Based on various types of targeted modifications, we primarily described delivery systems modified with receptor ligands, peptides, antibodies, aptamers and amino acids. Finally, we discussed the challenges and opportunities associated with siRNA delivery systems based on ionizable LNPs and CPs vectors.

Antibody immunotherapies for personalized opioid addiction treatment

Approved therapies for managing opioid addiction involve intensive treatment regimens which remain both costly and ineffective. As pharmaceutical interventions have achieved variable success treating substance use disorders (SUD), alternative therapeutics must be considered. Antidrug antibodies induced by vaccination or introduced as monoclonal antibody formulations can neutralize or destroy opioids in circulation before they reach their central nervous system targets or act as enzymes to deactivate opioid receptors, preventing the physiologic and psychoactive effects of the substance. A lack of "reward" for those suffering from SUD has been shown to result in cessation of use and promote long-term abstinence. Decreased antibody production costs and the advent of novel gene therapies that stimulate in vivo production of monoclonal antibodies have renewed interest in this strategy. Furthermore, advances in understanding of SUD immunopathogenesis have revealed distinct mechanisms of neuroimmune dysregulation underlying the disorder. Beyond assisting with cessation of drug use, antibody therapies could treat or reverse pathophysiologic hallmarks that contribute to addiction and which could be the cause of chronic cognitive defects resulting from drug use. In this review, we synthesize key current literature regarding the efficacy of immunotherapies in managing opioid addiction and SUD. We will explore the neuropharmacology underlying these treatments by relating evidence from studies on the use of antibody therapeutics to counteract various drug behaviors and by drawing parallels to the similar immunopathology observed in neurodegenerative disorders. Finally, we will discuss the implications of novel immunization technologies and the application of computational methods in developing personalized addiction treatments. SIGNIFICANCE STATEMENT: Significant new evidence contributing to our understanding of substance use disorders has recently emerged leading to a paradigm shift concerning the role of immunology in the neuropathogenesis of opioid use disorder. Concurrently, immunotherapeutic technologies such as antibody therapeutics have advanced the capabilities regarding applications that take advantage of these key principles. This article reviews key antibody-based treatments being studied and highlights directions for further research that may contribute to the management of opioid use disorder.

Intracellular trafficking of lipid nanoparticles is hindered by cholesterol

The intracellular trafficking of lipid nanoparticles (LNPs) leading to endosomal escape is critical for delivery efficiency. How components of LNP affect its intracellular trafficking and delivery efficiency remains unknown. Here, we developed a highly sensitive LNP/nucleic acid tracking platform based on streptavidin-biotin-DNA complex and high throughput imaging. Naked nucleic acids were found to be retained in the endocytotic vesicles proportional to endocytosis activity. With the help of LNP, nucleic acids were transported along the endolysosomal pathway with N/P ratio as low as 2 amongst very weak nucleic acid and LNP interaction. As the N/P ratio increases (concomitant concentration increase of all lipids), the monophasic endocytosis of LNP-DNA demonstrated biphasic characteristics, as shown by accumulation of LNP-DNA trapped in early endosomes in the peripheral of cells. Through a series of specifically designed LNPs, we found increase in N/P ratio alone, i.e. increase of ionizable lipid content, had no effect on the formation of peripheral LNP-endosomes. Importantly, increase in cholesterol content, via dose or concentration increase, positively correlated with formation and aggregation of peripheral LNP-endosomes. Meanwhile, helper lipid such as DSPC alleviated the detrimental effect of cholesterol on aggregation of peripheral LNP-endosomes. The trapping of LNP-nucleic acids in peripheral early endosomes hindered their intracellular trafficking along the endolysosomal pathway, thus reducing their reach to releasing compartments and diminishing cargo delivery efficiency. Our results demonstrate that high cholesterol content hinders LNP intracellular trafficking, which is detrimental for intracellular delivery of cargo.

Ether bond-modified lipid nanoparticles for enhancing the treatment effect of hepatic fibrosis

Lipid nanoparticle (LNP)-mediated RNA delivery holds significant potential for the treatment of various liver diseases. Ionizable lipids play a crucial role in the formulation of LNPs and directly influence their delivery efficiency. In this study, we introduced an innovative concept by incorporating an ether bond into the hydrophobic tail of ionizable lipids for the first time. Three ionizable lipids, namely, ND-O1, ND-O2, and ND-O3, were synthesized based on 1-octylnonyl 8-[(2-hydroxyethyl)-[8-(nonyloxy)-8-oxooctyl] amino] octanoate (Lipid M). The efficacy of lipids-based LNPs for the delivery of the heat shock protein 47 (HSP47)-targeted siRNA to the liver was investigated. Compared to Lipid M-based LNP (LNP-M), it was observed that ND-O1 based LNP (LNP-O1) exhibited enhanced siRNA transfection efficiency in activated fibroblasts. In the fibrosis mice, LNP-O1 effectively suppressed HSP47 expression by approximately 84%, which was three times more effective than LNP-M, resulting in a significant decrease of collagen deposition and an amelioration of liver fibrosis. These findings highlighted the potential application of ND-O1 as an ionizable lipid for enhancing the efficient delivery of LNPs-delivered siRNA to the liver. Furthermore, this ionizable lipid design strategy offers a promising avenue for the improvement of the LNP delivery system.