Rational Design of Bisphosphonate Lipid-like Materials for mRNA Delivery to the Bone Microenvironment

Furan-Derived Lipid Nanoparticles for Transporting mRNA to the Central Nervous System

Delivery of mRNA (mRNA) to the central nervous system (CNS) remains a significant challenge. Herein, we design a library of furan-derived lipids and, to our knowledge, for the first time, leverage the meningeal lymphatic vessels (MLVs) route to achieve efficient delivery of mRNA to the brain. These furan-derived lipids were engineered with different furan cores, functional groups, and tails. We found that tetrahydrofuran (THF)-derived lipid nanoparticles (LNPs) generally displayed exceptional mRNA delivery compared to their furan-based counterparts. Specifically, LNPs formulated with four-acetal-tail mono-THF-derived lipid F10T5 and four-acetal-tail di-THF-derived lipid F11T6 demonstrated significantly higher mRNA delivery efficiency to the brain compared with FDA-approved SM102 LNPs. The data revealed that these LNPs bypassed the blood-brain barrier (BBB) via the lymphatic pathway, traveling from deep cervical lymph nodes (dCLNs) to the meninges and subsequently entering brain cells. Collectively, this work provides valuable insights into engineering LNPs and exploring alternative approaches for the delivery of mRNA to the brain.

Janus dendritic ionizable lipids with fine designed headgroup and tails to improve mRNA delivery efficiency

Lipid nanoparticles (LNP) are recognized as the most efficient non-viral carriers for the delivery of nucleic acids including small interfering RNA (siRNA) and messenger RNA (mRNA). Ionizable lipid within the system is pivotal component influencing encapsulation, endosomal escape, delivery efficiency and immunogenicity. Accordingly, the precision design of ionizable lipids is a key step in the development of LNP. In this report, we constructed sixteen Janus dendritic ionizable lipids by varying numbers and alkyl chain length of tails based on different ionizable head containing hydroxyl and tertiary amine groups. The corresponding LNP were prepared by using microfluidic mixing device, with all samples exhibiting particle size around 100 nm and polydispersity index (PDI) below 0.2. In vivo validation demonstrates that two optimized ionizable lipids containing two hydroxy groups, two tertiary amines and six hydrophobic chain tails (U-502, U-503) show superior delivery efficiency compared to lipids with less tails and commercial ALC-0315. Hematoxylin and Eosin (H&E) staining of tissues, immunogenicity, liver and kidney function tests additionally confirm that both ionizable lipids have favorable biocompatibility and low in vivo toxicity. Lysosomal escape and cell transfection data verify the in vitro delivery efficacy of these LNP. Taken together, Janus dendritic lipids with fine designed ionizable head and multiple hydrophobic tails have improved mRNA delivery efficiency and biosafety, which may be promise in the development of delivery system.

Multivalent ionizable lipid-polypeptides for tumor-confined mRNA transfection

mRNA therapeutics is revolutionizing the treatment concepts toward many diseases including cancer. The potential of mRNA is, however, frequently limited by modest control over site of transfection. Here, we have explored a library of multivalent ionizable lipid-polypeptides (MILP) to achieve robust mRNA complexation and tumor-confined transfection. Leveraging the multivalent electrostatic, hydrophobic, and H-bond interactions, MILP efficiently packs both mRNA and plasmid DNA into sub-80 nm nanoparticles that are stable against lyophilization and long-term storage. The best MILP@mRNA complexes afford 8-fold more cellular uptake than SM-102 lipid nanoparticle formulation (SM-102 LNP), efficient endosomal disruption, and high transfection in different cells. Interestingly, MILP@mLuc displays exclusive tumor residence and distribution via multivalency-directed strong affinity and transcytosis, and affords specific protein expression in tumor cells and macrophages at tumor sites following intratumoral injection, in sharp contrast to the indiscriminate distribution and transfection in main organs of SM-102 LNP. Notably, MILP@mIL-12 with specific and efficient cytokine expression generates significant remodeling of tumor immunoenvironments and remarkable antitumor response in subcutaneous Lewis lung carcinoma and 4T1 tumor xenografts. MILP provides a unique strategy to site-specific transfection that may greatly broaden the applications of mRNA.

Intelligent Nanomaterials Design for Osteoarthritis Managements

Osteoarthritis (OA) is the most prevalent degenerative joint disorder, characterized by progressive joint degradation, pain, and diminished mobility, all of which collectively impair patients' quality of life and escalate healthcare expenditures. Current treatment options are often inadequate due to limited efficacy, adverse side effects, and temporary symptom relief, underscoring the urgent need for more effective therapeutic strategies. Recent advancements in nanomaterials and nanomedicines offer promising solutions by improving drug bioavailability, reducing side effects and providing targeted therapeutic benefits. This review critically examines the pathogenesis of OA, highlights the limitations of existing treatments, and explores the latest innovations in intelligent nanomaterials design for OA therapy, with an emphasis on their engineered properties, therapeutic mechanisms, and translational potential in clinical application. By compiling recent findings, this work aims to inspire further exploration and innovation in nanomedicine, ultimately advancing the development of more effective and personalized OA therapies.

Bone-brain interaction: mechanisms and potential intervention strategies of biomaterials

Following the discovery of bone as an endocrine organ with systemic influence, bone-brain interaction has emerged as a research hotspot, unveiling complex bidirectional communication between bone and brain. Studies indicate that bone and brain can influence each other's homeostasis via multiple pathways, yet there is a dearth of systematic reviews in this area. This review comprehensively examines interactions across three key areas: the influence of bone-derived factors on brain function, the effects of brain-related diseases or injuries (BRDI) on bone health, and the concept of skeletal interoception. Additionally, the review discusses innovative approaches in biomaterial design inspired by bone-brain interaction mechanisms, aiming to facilitate bone-brain interactions through materiobiological effects to aid in the treatment of neurodegenerative and bone-related diseases. Notably, the integration of artificial intelligence (AI) in biomaterial design is highlighted, showcasing AI's role in expediting the formulation of effective and targeted treatment strategies. In conclusion, this review offers vital insights into the mechanisms of bone-brain interaction and suggests advanced approaches to harness these interactions in clinical practice. These insights offer promising avenues for preventing and treating complex diseases impacting the skeleton and brain, underscoring the potential of interdisciplinary approaches in enhancing human health.

Developing mRNA Nanomedicines with Advanced Targeting Functions

The emerging messenger RNA (mRNA) nanomedicines have sprung up for disease treatment. Developing targeted mRNA nanomedicines has become a thrilling research hotspot in recent years, as they can be precisely delivered to specific organs or tissues to enhance efficiency and avoid side effects. Herein, we give a comprehensive review on the latest research progress of mRNA nanomedicines with targeting functions. mRNA and its carriers are first described in detail. Then, mechanisms of passive targeting, endogenous targeting, and active targeting are outlined, with a focus on various biological barriers that mRNA may encounter during in vivo delivery. Next, emphasis is placed on summarizing mRNA-based organ-targeting strategies. Lastly, the advantages and challenges of mRNA nanomedicines in clinical translation are mentioned. This review is expected to inspire researchers in this field and drive further development of mRNA targeting technology.

Transforming Medicine: Cutting-Edge Applications of Nanoscale Materials in Drug Delivery

Since their inception in the early 1960s, the development and use of nanoscale materials have progressed tremendously, and their roles in diverse fields ranging from human health to energy and electronics are undeniable. The application of nanotechnology inventions has revolutionized many aspects of everyday life including various medical applications and specifically drug delivery systems, maximizing the therapeutic efficacy of the contained drugs by means of bioavailability enhancement or minimization of adverse effects. In this review, we utilize the CAS Content Collection, a vast repository of scientific information extracted from journal and patent publications, to analyze trends in nanoscience research relevant to drug delivery in an effort to provide a comprehensive and detailed picture of the use of nanotechnology in this field. We examine the publication landscape in the area to provide insights into current knowledge advances and developments. We review the major classes of nanosized drug delivery systems, their delivery routes, and targeted diseases. We outline the most discussed concepts and assess the advantages of various nanocarriers. The objective of this review is to provide a broad overview of the evolving landscape of current knowledge regarding nanosized drug delivery systems, to outline challenges, and to evaluate growth opportunities. The merit of the review stems from the extensive, wide-ranging coverage of the most up-to-date scientific information, allowing unmatched breadth of landscape analysis and in-depth insights.

Protein corona formed on lipid nanoparticles compromises delivery efficiency of mRNA cargo

Lipid nanoparticles (LNPs) are the most clinically advanced nonviral RNA-delivery vehicles, though challenges remain in fully understanding how LNPs interact with biological systems. In vivo , proteins form an associated corona on LNPs that redefines their physicochemical properties and influences delivery outcomes. Despite its importance, the LNP protein corona is challenging to study owing to the technical difficulty of selectively recovering soft nanoparticles from biological samples. Herein, we developed a quantitative, label-free mass spectrometry-based proteomics approach to characterize the protein corona on LNPs. Critically, this protein corona isolation workflow avoids artifacts introduced by the presence of endogenous nanoparticles in human biofluids. We applied continuous density gradient ultracentrifugation for protein-LNP complex isolation, with mass spectrometry for protein identification normalized to protein composition in the biofluid alone. With this approach, we quantify proteins consistently enriched in the LNP corona including vitronectin, C-reactive protein, and alpha-2-macroglobulin. We explore the impact of these corona proteins on cell uptake and mRNA expression in HepG2 human liver cells, and find that, surprisingly, increased levels of cell uptake do not correlate with increased mRNA expression in part likely due to protein corona-induced lysosomal trafficking of LNPs. Our results underscore the need to consider the protein corona in the design of LNP-based therapeutics.

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Ionizable Cholesterol Analogs as the Fifth Component of Lipid Nanoparticles for Selective Targeting Delivery of mRNA

Lipid nanoparticles (LNP) have shown great promise in clinical applications for delivering mRNA. Targeted delivery of mRNA to particular tissues or organs is essential for precise therapeutic outcomes and minimized side effects in various disease models. However, achieving targeted delivery beyond the liver is a challenge based on current LNP formulations. In this report, we synthesized four ionizable cholesterol analogs by attaching two tertiary amine groups onto the head of a cholesterol-like structure and incorporated them as a fifth component into conventional commercial LNPs based on ALC-0315 or SM-102. Selective targeting delivery of mRNA is achieved by adjusting the proportion of the fifth component in the LNP. Specifically, a spleen-targeted 0315-Ergo-40% formulation demonstrated an impressive 95% delivery efficiency, while a lung-targeted 102-Sito-40% formulation achieved up to 78%. Moreover, when this strategy is applied to a self-developed ionizable lipid named U-101 instead of ALC-0315 or SM-102, the targeting delivery efficiencies to the spleen and lungs reach 96 and 71%, respectively. Multiple assessments suggest that inclusion of the fifth component does not compromise LNP stability, as indicated by consistent particle size, polydispersity index (PDI), and encapsulation efficiency. Furthermore, the test results of liver and kidney function and immunogenicity reveal no increase of toxicity in vivo following the introduction of the fifth component. Additional studies on in vitro cytotoxicity, lysosomal escape, and cellular transfection efficiency confirm that the fifth component does not diminish delivery performance. Taken together, the incorporation of ionizable cholesterol analogs leads to targeting of LNP delivery, which features strong organ selectivity, high safety, and suitability for further evaluation.

Piperazine-Derived Bisphosphonate-Based Ionizable Lipid Nanoparticles Enhance mRNA Delivery to the Bone Microenvironment

Nucleic acid delivery with mRNA lipid nanoparticles are being developed for targeting a wide array of tissues and cell types. However, targeted delivery to the bone microenvironment remains a significant challenge in the field, due in part to low local blood flow and poor interactions between drug carriers and bone material. Here we report bone-targeting ionizable lipids incorporating a piperazine backbone and bisphosphate moieties, which bind tightly with hydroxyapatite ([Ca5(PO4)3OH]), a key component of mineralized tissues. These lipids demonstrate biocompatibility and low toxicity in both vitro and in vivo studies. LNP formulated with these lipids facilitated efficient cellular transfection and improved binding to hydroxyapatite in vitro, and targeted delivery to the bone microenvironment in vivo following systemic administration. Overall, our findings demonstrate the critical role of the piperazine backbone in a novel ionizable lipid, which incorporates a bisphosphonate group to enable efficient bone-targeted delivery, highlighting the potential of rational design of ionizable lipids for next-generation bone-targeting delivery systems.

Multiarm-Assisted Design of Dendron-like Degradable Ionizable Lipids Facilitates Systemic mRNA Delivery to the Spleen

Lipid nanoparticles (LNPs) have emerged as pivotal vehicles for messenger RNA (mRNA) delivery to hepatocytes upon systemic administration and to antigen-presenting cells following intramuscular injection. However, achieving systemic mRNA delivery to non-hepatocytes remains challenging without the incorporation of targeting ligands such as antibodies, peptides, or small molecules. Inspired by comb-like polymeric architecture, here we utilized a multiarm-assisted design to construct a library of 270 dendron-like degradable ionizable lipids by altering the structures of amine heads and multiarmed tails for optimal mRNA delivery. Following in vitro high-throughput screening, a series of top-dendron-like LNPs with high transfection efficacy were identified. These dendron-like ionizable lipids facilitated greater mRNA delivery to the spleen in vivo compared to ionizable lipid analogs lacking dendron-like structure. Proteomic analysis of corona-LNP pellets showed enhancement of key protein clusters, suggesting potential endogenous targeting to the spleen. A lead dendron-like LNP formulation, 18-2-9b2, was further used to encapsulate Cre mRNA and demonstrated excellent genome modification in splenic macrophages, outperforming a spleen-tropic MC3/18PA LNP in the Ai14 mice model. Moreover, 18-2-9b2 LNP encapsulating therapeutic BTB domain and CNC homologue 1 (BACH1) mRNA exhibited proficient BACH1 expression and subsequent Spic downregulation in splenic red pulp macrophages (RPM) in a Spic-GFP transgene model upon intravenous administration. These results underscore the potential of dendron-like LNPs to facilitate mRNA delivery to splenic macrophages, potentially opening avenues for a range of mRNA-LNP therapeutic applications, including regenerative medicine, protein replacement, and gene editing therapies.

Interaction design in mRNA delivery systems

Following the coronavirus disease 2019 (COVID-19) pandemic, mRNA technology has made significant breakthroughs, emerging as a potential universal platform for combating various diseases. To address the challenges associated with mRNA delivery, such as instability and limited delivery efficacy, continuous advancements in genetic engineering and nanotechnology have led to the exploration and refinement of various mRNA structural modifications and delivery platforms. These achievements have significantly broadened the clinical applications of mRNA therapies. Despite the progress, the understanding of the interactions in mRNA delivery systems remains limited. These interactions are complex and multi-dimensional, occurring between mRNA and vehicles as well as delivery materials and helper ingredients. Resultantly, stability of the mRNA delivery systems and their delivery efficiency can be both significantly affected. This review outlines the current state of mRNA delivery strategies and summarizes the interactions in mRNA delivery systems. The interactions include the electrostatic interactions, hydrophobic interactions, hydrogen bonding, π-π stacking, coordination interactions, and so on. This interaction understanding provides guideline for future design of next-generation mRNA delivery systems, thereby offering new perspectives and strategies for developing diverse mRNA therapeutics.

Ionizable polymeric micelles (IPMs) for efficient siRNA delivery

Lipid nanoparticles (LNPs) are widely used for nucleic acid delivery but face challenges like limited targeting and accelerated blood clearance (ABC) effect. We design three ionizable oligomers (IOs) that, with polylactide-polyethylene glycol (PLA-PEG), form a potential siRNA delivery system, named Ionizable Polymeric Micelles (IPMs). The siRNA encapsulated IPMs escape from lysosomes upon cellular uptake, and silence the target gene. A fibroblast activation protein inhibitor modified IPMs (FAPi-IPMs) show higher targeting for activated hepatic stellate cells (HSCs) compared to that for hepatocytes, silencing both HSP47 and HMGB1, reducing collagen secretion and liver inflammation, thereby treating fibrosis. Moreover, IPMs and FAPi-IPMs mitigate ABC effect and produce fewer PEG antibodies than LNPs, and show minimal apolipoprotein adsorption in vivo compared with LNPs, differentiating their targeting effects from LNPs. In conclusion, IPMs represent a nucleic acid delivery system with alternative targeting ability and reduced ABC effect.

Nonviral targeted mRNA delivery: principles, progresses, and challenges

Messenger RNA (mRNA) therapeutics have garnered considerable attention due to their remarkable efficacy in the treatment of various diseases. The COVID-19 mRNA vaccine and RSV mRNA vaccine have been approved on the market. Due to the inherent nuclease-instability and negative charge of mRNA, delivery systems are developed to protect the mRNA from degradation and facilitate its crossing cell membrane to express functional proteins or peptides in the cytoplasm. However, the deficiency in transfection efficiency and targeted biological distribution are still the major challenges for the mRNA delivery systems. In this review, we first described the physiological barriers in the process of mRNA delivery and then discussed the design approach and recent advances in mRNA delivery systems with an emphasis on their tissue/cell-targeted abilities. Finally, we pointed out the existing challenges and future directions with deep insights into the design of efficient mRNA delivery systems. We believe that a high-precision targeted delivery system can greatly improve the therapeutic effects and bio-safety of mRNA therapeutics and accelerate their clinical transformations. This review may provide a new direction for the design of mRNA delivery systems and serve as a useful guide for researchers who are looking for a suitable mRNA delivery system.

Combinatorial design of siloxane-incorporated lipid nanoparticles augments intracellular processing for tissue-specific mRNA therapeutic delivery

Systemic delivery of messenger RNA (mRNA) for tissue-specific targeting using lipid nanoparticles (LNPs) holds great therapeutic potential. Nevertheless, how the structural characteristics of ionizable lipids (lipidoids) impact their capability to target cells and organs remains unclear. Here we engineered a class of siloxane-based ionizable lipids with varying structures and formulated siloxane-incorporated LNPs (SiLNPs) to control in vivo mRNA delivery to the liver, lung and spleen in mice. The siloxane moieties enhance cellular internalization of mRNA-LNPs and improve their endosomal escape capacity, augmenting their mRNA delivery efficacy. Using organ-specific SiLNPs to deliver gene editing machinery, we achieve robust gene knockout in the liver of wild-type mice and in the lungs of both transgenic GFP and Lewis lung carcinoma (LLC) tumour-bearing mice. Moreover, we showed effective recovery from viral infection-induced lung damage by delivering angiogenic factors with lung-targeted Si5-N14 LNPs. We envision that our SiLNPs will aid in the clinical translation of mRNA therapeutics for next-generation tissue-specific protein replacement therapies, regenerative medicine and gene editing.

An "All-in-One" Strategy to Reconstruct Temporomandibular Joint Osteoarthritic Microenvironment Using γ-Fe2O3@TA@ALN Nanoparticles

Current clinical strategies for the treatment of temporomandibular joint osteoarthritis (TMJOA) primarily target cartilage biology, overlooking the synergetic effect of various cells and inorganic components in shaping the arthritic microenvironment, thereby impeding the effectiveness of existing therapeutic options for TMJOA. Here, γ-Fe2O3@TA@ALN magnetic nanoparticles (γ-Fe2O3@TA@ALN MNPs) composed of γ-Fe2O3, tannic acid (TA), and alendronate sodium (ALN) are engineered to reconstruct the osteoarthritic microenvironment and mitigate TMJOA progression. γ-Fe2O3@TA@ALN MNPs can promote chondrocytes' proliferation, facilitate chondrogenesis and anisotropic organization, enhance lubrication and reduce cartilage wear, and encourage cell movement. Magnetic-responsive γ-Fe2O3@TA@ALN MNPs also exhibit pH sensitivity, which undergoes decomposition within acidic environment to release ALN on demand. Under a 0.2 T static magnetic field, γ-Fe2O3@TA@ALN MNPs accelerate the synthesis of cartilage-specific proteins, and suppress catabolic-related genes expression and reactive oxygen species generation, affording additional protection to TMJ cartilage. In TMJOA mouse models, articular injection of γ-Fe2O3@TA@ALN MNPs effectively alleviates cartilage degeneration and subchondral bone loss in short and long terms, offering promising avenues for the development of therapeutic interventions for TMJOA.

Placenta-tropic VEGF mRNA lipid nanoparticles ameliorate murine pre-eclampsia

Pre-eclampsia is a placental disorder that affects 3-5% of all pregnancies and is a leading cause of maternal and fetal morbidity worldwide1,2. With no drug available to slow disease progression, engineering ionizable lipid nanoparticles (LNPs) for extrahepatic messenger RNA (mRNA) delivery to the placenta is an attractive therapeutic option for pre-eclampsia. Here we use high-throughput screening to evaluate a library of 98 LNP formulations in vivo and identify a placenta-tropic LNP (LNP 55) that mediates more than 100-fold greater mRNA delivery to the placenta in pregnant mice than a formulation based on the Food and Drug Administration-approved Onpattro LNP (DLin-MC3-DMA)3. We propose an endogenous targeting mechanism based on β2-glycoprotein I adsorption that enables LNP delivery to the placenta. In both inflammation- and hypoxia-induced models of pre-eclampsia, a single administration of LNP 55 encapsulating vascular endothelial growth factor (VEGF) mRNA resolves maternal hypertension until the end of gestation. In addition, with our VEGF mRNA LNP 55 therapeutic, we demonstrate improvements in fetal health and partially restore placental vasculature, the local and systemic immune landscape and serum levels of soluble Fms-like tyrosine kinase-1, a clinical biomarker of pre-eclampsia1. Together, these results demonstrate the potential of this mRNA LNP platform for treating placental disorders such as pre-eclampsia.

Dynamic Covalent Prodrug Nanonetworks via Reaction-Induced Self-Assembly for Periodontitis Treatment

Periodontitis is characterized by dysbiotic biofilms, gingival inflammation, and bone resorption, highlighting the urgent need for a comprehensive approach to drug combination therapy. In this study, we introduce dynamic covalent nanonetworks (dcNNWs) synthesized through a one-pot, four-component reaction-induced self-assembly method using polyamines, 2-formylphenylboronic acid, epigallocatechin gallate, and alendronate. The formation of iminoboronate bonds drives the creation of dcNNWs, allowing controlled release in the periodontitis microenvironment. The inclusion of catechol and bisphosphonate imparts exceptional bioadhesive properties to the dcNNWs, enhancing their efficacy in preventing pathogenic bacterial biofilm formation and eliminating mature biofilms. Moreover, the dcNNWs efficiently absorb pathogen-associated molecular patterns and scavenge excess reactive oxygen species, regulating the local immune response and demonstrating anti-inflammatory effects. Additionally, the released polyphenol and alendronate from the dcNNWs alleviated inflammation and enhanced osteogenesis significantly. The detailed synergistic effects of dcNNWs in biofilm eradication, anti-inflammation, and bone remodeling, with minimal impact on healthy tissues, are confirmed in a rat model of periodontitis. With a facile synthesis process, excellent synergistic effects in periodontitis treatment, and biocompatibility, our dcNNWs present a promising and translational solution for the effective management of periodontitis.

Isosteric 3D Bicyclo[1.1.1]Pentane (BCP) Core-Based Lipids for mRNA Delivery and CRISPR/Cas Gene Editing

Lipid nanoparticles (LNPs) are an essential component of messenger RNA (mRNA) vaccines and genome editing therapeutics. Ionizable amino lipids, which play the most crucial role in enabling mRNA to overcome delivery barriers, have, to date, been restricted to two-dimensional (2D) architectures. Inspired by improved physicochemical properties resulting from the incorporation of three-dimensionality (3D) into small-molecule drugs, we report the creation of 3D ionizable lipid designs through the introduction of bicyclo[1.1.1]pentane (BCP) core motifs. BCP-based lipids enabled efficient in vivo mRNA delivery to the liver and spleen with significantly greater performance over 2D benzene- and cyclohexane-based analogues. Notably, lead BCP-NC2-C12 LNPs mediated ∼90% reduction in the PCSK9 serum protein level via CRISPR/Cas9 gene knockout, outperforming 2D controls and clinically used DLin-MC3-DMA LNPs at the same dose. Here, we introduce BCP-based designs with superior in vivo activity, thereby expanding the chemical scope of ionizable amino lipids from 2D to 3D and offering a promising avenue to improve mRNA and gene editing efficiency for the continued development of genetic medicines.

Drug-phospholipid conjugate nano-assembly for drug delivery

Phospholipid-based liposomes are among the most successful nanodrug delivery systems in clinical use. However, these conventional liposomes present significant challenges including low drug-loading capacity and issues with drug leakage. Drug-phospholipid conjugates (DPCs) and their assemblies offer a promising strategy for addressing these limitations. In this review, we summarize recent advances in the design, synthesis, and application of DPCs for drug delivery. We begin by discussing the chemical backbone structures and various design strategies such as phosphate head embedding and mono-/bis-embedding in the sn-1/sn-2 positions. Furthermore, we highlight stimulus-responsive designs of DPCs and their applications in treating diseases such as cancer, inflammation, and malaria. Lastly, we explore future directions for DPCs development and their potential applications in drug delivery.

Manganese Oxide-Incorporated Hybrid Lipid Nanoparticles Amplify the Potency of mRNA Vaccine via Oxygen Generation and STING Activation

Messenger RNA (mRNA) vaccines have exhibited enormous potential in the treatment of human diseases; however, their widespread applications are curtailed by the induction of reactive oxygen species during mRNA translation, which greatly compromises the translation efficiency. Herein, we present a robust strategy with the capability to substantially enhance the efficacy of the mRNA vaccine through promoting mRNA translation and stimulator of interferon genes (STING) activation. The strategy entails the coassembly of small-sized manganese oxide nanoparticles (Mn3O4 NPs) with lipid nanoparticles (LNPs) as the hybrid delivery vehicle (MnLNPs) for the fabrication of mRNA vaccine. The acquired MnLNPs proficiently scavenge reactive oxygen species (ROS) produced during mRNA translation and facilitate oxygen production, thereby boosting adenosine triphosphate (ATP) synthesis and augmenting mRNA translation. Furthermore, MnLNPs effectively bolster the antigen presentation and maturation of dendritic cells by activating the cGAS-STING pathway. In vivo studies demonstrate that mRNA vaccine prepared from MnLNPs markedly enhances the translation of antigen-encoding mRNA compared to LNPs, leading to superior antitumor efficacy. The tumor-suppressive capabilities of MnLNPs@mRNA are further promoted by synergizing with immune checkpoint blockade, underscoring MnLNPs-based mRNA vaccine as an exceptionally promising avenue in cancer immunotherapy.

Navigating the intricate in-vivo journey of lipid nanoparticles tailored for the targeted delivery of RNA therapeutics: a quality-by-design approach

RNA therapeutics, such as mRNA, siRNA, and CRISPR-Cas9, present exciting avenues for treating diverse diseases. However, their potential is commonly hindered by vulnerability to degradation and poor cellular uptake, requiring effective delivery systems. Lipid nanoparticles (LNPs) have emerged as a leading choice for in vivo RNA delivery, offering protection against degradation, enhanced cellular uptake, and facilitation of endosomal escape. However, LNPs encounter numerous challenges for targeted RNA delivery in vivo, demanding advanced particle engineering, surface functionalization with targeting ligands, and a profound comprehension of the biological milieu in which they function. This review explores the structural and physicochemical characteristics of LNPs, in-vivo fate, and customization for RNA therapeutics. We highlight the quality-by-design (QbD) approach for targeted delivery beyond the liver, focusing on biodistribution, immunogenicity, and toxicity. In addition, we explored the current challenges and strategies associated with LNPs for in-vivo RNA delivery, such as ensuring repeated-dose efficacy, safety, and tissue-specific gene delivery. Furthermore, we provide insights into the current clinical applications in various classes of diseases and finally prospects of LNPs in RNA therapeutics.

Synergistic integration of mRNA-LNP with CAR-engineered immune cells: Pioneering progress in immunotherapy

Chimeric antigen receptor T cell (CAR-T) therapy has emerged as a revolutionary approach in the treatment of malignancies. Despite its remarkable successes, this field continues to grapple with challenges such as scalability, safety concerns, limited therapeutic effect, in vivo persistence, and the need for precise control over CAR expression. In the post-pandemic era of COVID-19 vaccine immunization, the application of messenger RNA (mRNA) encapsulated within lipid nanoparticles (LNPs) has recently garnered significant attention as a potential solution to address these challenges. This review delves into the dynamic landscape of mRNA-LNP technology and its potential implications for CAR-engineered immune cell-based immunotherapy.

Tuning Lipid Nanoparticles for RNA Delivery to Extrahepatic Organs

RNA therapeutics have been successfully transitioned into clinical applications. Lipid nanoparticles (LNPs) are widely employed as nonviral delivery vehicles for RNA therapeutics in commercial vaccine and gene therapy products. However, the bottleneck in expanding the clinical applications of LNP-based RNA therapeutics lies in the tendency of these nanoparticles to preferentially accumulate in the liver. This challenge underscores the need to design LNPs capable of delivering RNA to organs beyond the liver. In this perspective, recent progress is discussed in developing strategies for designing LNPs to deliver RNA to extrahepatic organs. Organ-selective targeting capability is achieved by either altering the composition of the LNP formulation or chemically modifying the ionizable lipid component. Both approaches result in changes in the physicochemical properties of the LNPs, which subsequently alters the composition of the biomolecular corona that adsorbs onto its surface following administration. The biomolecular corona is a known mechanism that mediates organ-selective LNP delivery. Furthermore, this perspective aims to provide an outlook on shaping the next-generation LNP delivery platforms. Potential efforts include targeting specific cell types, improving the safety profile of LNPs, and developing strategies to overcome physiological barriers against organ-specific delivery.

Targeting TUBB3 Suppresses Anoikis Resistance and Bone Metastasis in Prostate Cancer

Bone metastases occur in more than 70% of advanced prostate cancer (PCa) patients, leading to a poor prognosis. Resistance to detachment-induced apoptosis, also known as anoikis, plays a crucial role in the onset of tumor metastasis. Targeting anoikis resistance is of immense therapeutic significance in repression of metastatic spread. In this study, based on an anoikis-related prognostic risk model of PCa, this study identifies TUBB3 as a key anoikis-related prognostic gene that is highly expressed in bone metastatic PCa. TUBB3 expression is increased in anoikis-resistant PCa cells, and TUBB3 depletion significantly reverses anoikis resistance during extracellular matrix (ECM) detachment and inhibits anoikis-resistance-induced PCa cell invasion and migration as well as epithelial-mesenchymal transition (EMT) process. TUBB3 knockdown significantly reduces αvβ3/FAK/Src axis activation, blocking its downstream oncogenic signaling. In addition, this work develops bone-targeting lipid nanoparticles (BT-LNP) based on bisphosphonate-modified ionizable lipid for systemic delivery of siRNA targeting TUBB3 (siTUBB3). BT-LNP-delivered siTUBB3 therapy with localization in the bone microenvironment significantly attenuate PCa bone metastasis progression in vivo upon intravenous administration. These findings pinpoint that TUBB3, as a key regulator of anoikis resistance, is an effective therapeutic target in bone metastatic PCa and that BT-LNP-mediated systemic delivery of siTUBB3 can be developed as a novel therapeutic strategy for this disease.

Enhancing RNA-lipid nanoparticle delivery: Organ- and cell-specificity and barcoding strategies

Recent advancements in RNA therapeutics highlight the critical need for precision gene delivery systems that target specific organs and cells. Lipid nanoparticles (LNPs) have emerged as key vectors in delivering mRNA and siRNA, offering protection against enzymatic degradation, enabling targeted delivery and cellular uptake, and facilitating RNA cargo release into the cytosol. This review discusses the development and optimization of organ- and cell-specific LNPs, focusing on their design, mechanisms of action, and therapeutic applications. We explore innovations such as DNA/RNA barcoding, which facilitates high-throughput screening and precise adjustments in formulations. We address major challenges, including improving endosomal escape, minimizing off-target effects, and enhancing delivery efficiencies. Notable clinical trials and recent FDA approvals illustrate the practical applications and future potential of LNP-based RNA therapies. Our findings suggest that while considerable progress has been made, continued research is essential to resolve existing limitations and bridge the gap between preclinical and clinical evaluation of the safety and efficacy of RNA therapeutics. This review highlights the dynamic progress in LNP research. It outlines a roadmap for future advancements in RNA-based precision medicine.

Bone Destruction-Chemotactic Osteoprogenitor Cells Deliver Liposome Nanomedicines for the Treatment of Osteosarcoma and Osteoporosis

Therapeutic efficacy of skeletal diseases is usually limited by unfavorable drug delivery due to incapable bone targeting and low bone affinity of conventional drug carriers, as well as relatively reduced vascularization and dense structure of bone tissues. Due to CXC chemokine receptor 4 (CXCR4)/CXC chemokine ligand 12 (CXCL12) signal axis-guided recruitment, osteoprogenitor cells (OPCs) can actively migrate to bone disease nidus. Here, drugs-loaded nanoliposomes are prepared and decorated onto OPCs by biotin-streptavidin linkage for precise bone disease targeting and effective drug delivery. In mouse models of tibia defect and orthotopic osteosarcoma, superior targeting property of OPCs-based drug delivery systems toward diseased bone niduses is verified. By encapsulating antitumor and antiosteoporosis drugs into nanoliposomes, OPCs-based drug delivery systems effectively inhibit disease development and restore bone destruction in mouse models of orthotopic osteosarcoma and ovariectomized osteoporosis. This study reveals a cell-based drug delivery system for precise bone disease targeting and highly effective drug delivery, which will find great potential as a universal drug delivery platform for targeting treatment of various bone diseases.

Development of Organ Targeting Lipid Nanoparticles with Low Immunogenicity and Their Application in the Treatment of Pulmonary Fibrosis

As the most advanced non-viral delivery system, lipid nanoparticles (LNPs) were approved by the FDA, propelling the advancements of gene therapy. However, their clinical applications are hampered by the potential immunogenicity of the lipid components that trigger immune-related adverse events, like inflammation and allergy. Herein, we formulate various dLNPs with diminished immunogenicity by incorporating dexamethasone (Dex) into liver-, spleen-, and lung-targeting LNPs formulations that exhibit excellent abilities to target specific organs and deliver various types of RNA, such as mRNA and siRNA. In vivo investigations demonstrate unparalleled advantages in safety as compared to conventional LNPs, showing promising potential in the development of RNA therapeutics. Intriguingly, the encapsulation of runt-related transcription factor-1 siRNA (siRUNX1) into lung-targeting dLNPs (dLNPs@siRUNX1) demonstrates remarkable advantages in the treatment of pulmonary fibrosis through the synergy of gene therapy and drug therapy. This research establishes secure and universal platforms for the precise delivery of nucleic acid therapeutics, showcasing promising clinical applications in gene therapy.

Recent Advances in Lipid Nanoparticles and Their Safety Concerns for mRNA Delivery

INTRODUCTION

The advent of lipid nanoparticles (LNPs) as a delivery platform for mRNA therapeutics has revolutionized the biomedical field, particularly in treating infectious diseases, cancer, genetic disorders, and metabolic diseases. Recent Advances in Therapeutic LNPs: LNPs, composed of ionizable lipids, phospholipids, cholesterol, and polyethylene glycol (PEG) lipids, facilitate efficient cellular uptake and cytosolic release of mRNA while mitigating degradation by nucleases. However, as synthetic entities, LNPs face challenges that alter their therapeutic efficacy and safety concerns. Toxicity/Reactogenicity/Immunogenicity: This review provides a comprehensive overview of the latest advancements in LNP research, focusing on preclinical safety assessments encompassing toxicity, reactogenicity, and immunogenicity. Summary and Outlook: Additionally, it outlines potential strategies for addressing these challenges and offers insights into future research directions for enhancing the application of LNPs in mRNA therapeutics.

Lipid nanoparticles-based RNA therapies for breast cancer treatment

Breast cancer (BC) prevails as a major burden on global healthcare, being the most prevalent form of cancer among women. BC is a complex and heterogeneous disease, and current therapies, such as chemotherapy and radiotherapy, frequently fall short in providing effective solutions. These treatments fail to mitigate the risk of cancer recurrence and cause severe side effects that, in turn, compromise therapeutic responses in patients. Over the last decade, several strategies have been proposed to overcome these limitations. Among them, RNA-based technologies have demonstrated their potential across various clinical applications, notably in cancer therapy. However, RNA therapies are still limited by a series of critical issues like off-target effect and poor stability in circulation. Thus, novel approaches have been investigated to improve the targeting and bioavailability of RNA-based formulations to achieve an appropriate therapeutic outcome. Lipid nanoparticles (LNPs) have been largely proven to be an advantageous carrier for nucleic acids and RNA. This perspective explores the most recent advances on RNA-based technology with an emphasis on LNPs' utilization as effective nanocarriers in BC therapy and most recent progresses in their clinical applications.

Development of mRNA Lipid Nanoparticles: Targeting and Therapeutic Aspects

Lipid nanoparticles (LNPs) have emerged as leading non-viral carriers for messenger RNA (mRNA) delivery in clinical applications. Overcoming challenges in safe and effective mRNA delivery to target tissues and cells, along with controlling release from the delivery vehicle, remains pivotal in mRNA-based therapies. This review elucidates the structure of LNPs, the mechanism for mRNA delivery, and the targeted delivery of LNPs to various cells and tissues, including leukocytes, T-cells, dendritic cells, Kupffer cells, hepatic endothelial cells, and hepatic and extrahepatic tissues. Here, we discuss the applications of mRNA-LNP vaccines for the prevention of infectious diseases and for the treatment of cancer and various genetic diseases. Although challenges remain in terms of delivery efficiency, specific tissue targeting, toxicity, and storage stability, mRNA-LNP technology holds extensive potential for the treatment of diseases.

Bone targeted nano-drug and nano-delivery

There are currently no targeted delivery systems to satisfactorily treat bone-related disorders. Many clinical drugs consisting of small organic molecules have a short circulation half-life and do not effectively reach the diseased tissue site. This coupled with repeatedly high dose usage that leads to severe side effects. With the advance in nanotechnology, drugs contained within a nano-delivery device or drugs aggregated into nanoparticles (nano-drugs) have shown promises in targeted drug delivery. The ability to design nanoparticles to target bone has attracted many researchers to develop new systems for treating bone related diseases and even repurposing current drug therapies. In this review, we shall summarise the latest progress in this area and present a perspective for future development in the field. We will focus on calcium-based nanoparticle systems that modulate calcium metabolism and consequently, the bone microenvironment to inhibit disease progression (including cancer). We shall also review the bone affinity drug family, bisphosphonates, as both a nano-drug and nano-delivery system for bone targeted therapy. The ability to target and release the drug in a controlled manner at the disease site represents a promising safe therapy to treat bone diseases in the future.

Strategies for Organ-Targeted mRNA Delivery by Lipid Nanoparticles

Messenger RNA (mRNA) technology has rapidly evolved, significantly impacting various therapeutic applications, including vaccines, protein replacement, and gene editing. Lipid nanoparticles (LNPs) have emerged as a pivotal nonviral vector for mRNA delivery, crucial for organ-targeted therapies. Despite their success, most LNP formulations predominantly target the liver, limiting their use in nonliver diseases. This review explores strategies to achieve organ-specific mRNA delivery using LNPs, including the discovery of new lipid structures, modification of targeting ligands, incorporation of additional components, and optimization of LNP formulations. These advancements aim to enhance the precision and efficacy of mRNA therapeutics across a broader range of diseases.

Advances in the development of lipid nanoparticles for ophthalmic therapeutics

Previously, researchers have employed Lipid nanoparticles (LNPs) to directly encapsulate medicines. In the realm of gene therapy, researchers have begun to employ lipid nanoparticles to encapsulate nucleic acids such as messenger RNA, small interfering RNA, and plasmid DNA, which are known as nucleic acid lipid nanoparticles. Recent breakthroughs in LNP-based medicine have provided significant prospects for the treatment of ocular disorders, such as corneal, choroidal, and retinal diseases. The use of LNP as a delivery mechanism for medicines and therapeutic genes can increase their effectiveness while avoiding undesired immune reactions. However, LNP-based medicines may pose ocular concerns. In this review, we discuss the general framework of LNP. Additionally, we review adjustable approaches and evaluate their possible risks. In addition, we examine newly described ocular illnesses in which LNP was utilized as a delivery mechanism. Finally, we provide perspectives for solving these potential issues.

Bone-marrow-homing lipid nanoparticles for genome editing in diseased and malignant haematopoietic stem cells

Therapeutic genome editing of haematopoietic stem cells (HSCs) would provide long-lasting treatments for multiple diseases. However, the in vivo delivery of genetic medicines to HSCs remains challenging, especially in diseased and malignant settings. Here we report on a series of bone-marrow-homing lipid nanoparticles that deliver mRNA to a broad group of at least 14 unique cell types in the bone marrow, including healthy and diseased HSCs, leukaemic stem cells, B cells, T cells, macrophages and leukaemia cells. CRISPR/Cas and base editing is achieved in a mouse model expressing human sickle cell disease phenotypes for potential foetal haemoglobin reactivation and conversion from sickle to non-sickle alleles. Bone-marrow-homing lipid nanoparticles were also able to achieve Cre-recombinase-mediated genetic deletion in bone-marrow-engrafted leukaemic stem cells and leukaemia cells. We show evidence that diverse cell types in the bone marrow niche can be edited using bone-marrow-homing lipid nanoparticles.

Discovery of a Peptoid-Based Nanoparticle Platform for Therapeutic mRNA Delivery via Diverse Library Clustering and Structural Parametrization

Nanoparticle-mediated mRNA delivery has emerged as a promising therapeutic modality, but its growth is still limited by the discovery and optimization of effective and well-tolerated delivery strategies. Lipid nanoparticles containing charged or ionizable lipids are an emerging standard for in vivo mRNA delivery, so creating facile, tunable strategies to synthesize these key lipid-like molecules is essential to advance the field. Here, we generate a library of N-substituted glycine oligomers, peptoids, and undertake a multistage down-selection process to identify lead candidate peptoids as the ionizable component in our Nutshell nanoparticle platform. First, we identify a promising peptoid structural motif by clustering a library of >200 molecules based on predicted physical properties and evaluate members of each cluster for reporter gene expression in vivo. Then, the lead peptoid motif is optimized using design of experiments methodology to explore variations on the charged and lipophilic portions of the peptoid, facilitating the discovery of trends between structural elements and nanoparticle properties. We further demonstrate that peptoid-based Nutshells leads to expression of therapeutically relevant levels of an anti-respiratory syncytial virus antibody in mice with minimal tolerability concerns or induced immune responses compared to benchmark ionizable lipid, DLin-MC3-DMA. Through this work, we present peptoid-based nanoparticles as a tunable delivery platform that can be optimized toward a range of therapeutic programs.

Chemical Design Strategy of Ionizable Lipids for In Vivo mRNA Delivery

Lipid nanoparticles (LNPs) are the most clinically successful drug delivery systems that have accelerated the development of mRNA drugs and vaccines. Among various structural components of LNPs, more recent attention has been paid in ionizable lipids (ILs) that was supposed as the key component in determining the effectiveness of LNPs for in vivo mRNA delivery. ILs are typically comprised of three moieties including ionizable heads, linkers, and hydrophobic tails, which suggested that the combination of different functional groups in three moieties could produce ILs with diverse chemical structures and biological identities. In this concept article, we provide a summary of chemical design strategy for high-performing IL candidates and discuss their structure-activity relationships for shifting tissue-selective mRNA delivery. We also propose an outlook for the development of next-generation ILs, enabling the broader translation of mRNA formulated with LNPs.

Rational design of lipid nanoparticles: overcoming physiological barriers for selective intracellular mRNA delivery

This review introduces the typical delivery process of messenger RNA (mRNA) nanomedicines and concludes that the delivery involves a at least four-step SCER cascade and that high efficiency at every step is critical to guarantee high overall therapeutic outcomes. This SCER cascade process includes selective organ-targeting delivery, cellular uptake, endosomal escape, and cytosolic mRNA release. Lipid nanoparticles (LNPs) have emerged as a state-of-the-art vehicle for in vivo mRNA delivery. The review emphasizes the importance of LNPs in achieving selective, efficient, and safe mRNA delivery. The discussion then extends to the technical and clinical considerations of LNPs, detailing the roles of individual components in the SCER cascade process, especially ionizable lipids and helper phospholipids. The review aims to provide an updated overview of LNP-based mRNA delivery, outlining recent innovations and addressing challenges while exploring future developments for clinical translation over the next decade.

An overview of lipid constituents in lipid nanoparticle mRNA delivery systems

mRNA therapeutics have shown great potential for a broad spectrum of disease treatment. However, the challenges of mRNA's inherent instability and difficulty in cellular entry have hindered its progress in the biomedical field. To address the cellular barriers and deliver mRNA to cells of interest, various delivery systems are designed. Among these, lipid nanoparticles (LNPs) stand out as the most extensively used mRNA delivery systems, particularly following the clinical approvals of corona virus disease 2019 (COVID-19) mRNA vaccines. LNPs are comprised of ionizable cationic lipids, phospholipids, cholesterol, and polyethylene glycol derived lipids (PEG-lipids). In this review, we primarily summarize the recent advancements of the LNP mRNA delivery technology, focusing on the structures of four lipid constituents and their biomedical applications. We delve into structure-activity relationships of the lipids, while also exploring the future prospects and challenges in developing more efficacious mRNA delivery systems. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Comparative optimization of polysaccharide-based nanoformulations for cardiac RNAi therapy

Ionotropic gelation is widely used to fabricate targeting nanoparticles (NPs) with polysaccharides, leveraging their recognition by specific lectins. Despite the fabrication scheme simply involves self-assembly of differently charged components in a straightforward manner, the identification of a potent combinatory formulation is usually limited by structural diversity in compound collections and trivial screen process, imposing crucial challenges for efficient formulation design and optimization. Herein, we report a diversity-oriented combinatory formulation screen scheme to identify potent gene delivery cargo in the context of precision cardiac therapy. Distinct categories of cationic compounds are tested to construct RNA delivery system with an ionic polysaccharide framework, utilizing a high-throughput microfluidics workstation coupled with streamlined NPs characterization system in an automatic, step-wise manner. Sequential computational aided interpretation provides insights in formulation optimization in a broader scenario, highlighting the usefulness of compound library diversity. As a result, the out-of-bag NPs, termed as GluCARDIA NPs, are utilized for loading therapeutic RNA to ameliorate cardiac reperfusion damages and promote the long-term prognosis. Overall, this work presents a generalizable formulation design strategy for polysaccharides, offering design principles for combinatory formulation screen and insights for efficient formulation identification and optimization.

High-Throughput In Vivo Screening Identifies Differential Influences on mRNA Lipid Nanoparticle Immune Cell Delivery by Administration Route

Immune modulation through the intracellular delivery of nucleoside-modified mRNA to immune cells is an attractive approach for in vivo immunoengineering, with applications in infectious disease, cancer immunotherapy, and beyond. Lipid nanoparticles (LNPs) have come to the fore as a promising nucleic acid delivery platform, but LNP design criteria remain poorly defined, making the rate-limiting step for LNP discovery the screening process. In this study, we employed high-throughput in vivo LNP screening based on molecular barcoding to investigate the influence of LNP composition on immune tropism with applications in vaccines and systemic immunotherapies. Screening a large LNP library under both intramuscular (i.m.) and intravenous (i.v.) injection, we observed differential influences on LNP uptake by immune populations across the two administration routes, gleaning insight into LNP design criteria for in vivo immunoengineering. In validation studies, the lead LNP formulation for i.m. administration demonstrated substantial mRNA translation in the spleen and draining lymph nodes with a more favorable biodistribution profile than LNPs formulated with the clinical standard ionizable lipid DLin-MC3-DMA (MC3). The lead LNP formulations for i.v. administration displayed potent immune transfection in the spleen and peripheral blood, with one lead LNP demonstrating substantial transfection of splenic dendritic cells and another inducing substantial transfection of circulating monocytes. Altogether, the immunotropic LNPs identified by high-throughput in vivo screening demonstrated significant promise for both locally- and systemically-delivered mRNA and confirmed the value of the LNP design criteria gleaned from our screening process, which could potentially inform future endeavors in mRNA vaccine and immunotherapy applications.

Inflammatory microenvironment regulation and osteogenesis promotion by bone-targeting calcium and magnesium repletion nanoplatform for osteoporosis therapy

Osteoporosis is the most common bone metabolic disease that affects the health of middle-aged and elderly people, which is hallmarked by imbalanced bone remodeling and a deteriorating immune microenvironment. Magnesium and calcium are pivotal matrix components that participate in the bone formation process, especially in the immune microenvironment regulation and bone remodeling stages. Nevertheless, how to potently deliver magnesium and calcium to bone tissue remains a challenge. Here, we have constructed a multifunctional nanoplatform composed of calcium-based upconversion nanoparticles and magnesium organic frameworks (CM-NH2-PAA-Ald, denoted as CMPA), which features bone-targeting and pH-responsive properties, effectively regulating the inflammatory microenvironment and promoting the coordination of osteogenic functions for treating osteoporosis. The nanoplatform can efficaciously target bone tissue and gradually degrade in response to the acidic microenvironment of osteoporosis to release magnesium and calcium ions. This study validates that CMPA possessing favorable biocompatibility can suppress inflammation and facilitate osteogenesis to treat osteoporosis. Importantly, high-throughput sequencing results demonstrate that the nanoplatform exerts a good inflammatory regulation effect through inhibition of the nuclear factor kappa-B signaling pathway, thereby normalizing the osteoporotic microenvironment. This collaborative therapeutic strategy that focuses on improving bone microenvironment and promoting osteogenesis provides new insight for the treatment of metabolic diseases such as osteoporosis.

Leveraging high-throughput screening technologies in targeted mRNA delivery

Messenger ribonucleic acid (mRNA) has emerged as a promising molecular preventive and therapeutic approach that opens new avenues for healthcare. Although the use of delivery systems, especially lipid nanoparticles (LNPs), greatly improves the efficiency and stability of mRNA, mRNA tends to accumulate in the liver and hardly penetrates physiological barriers to reach the target site after intravenous injection. Hence, the rational design of targeting strategies aimed at directing mRNA to specific tissues and cells remains an enormous challenge in mRNA therapy. High-throughput screening (HTS) is a cutting-edge targeted technique capable of synthesizing chemical compound libraries for the large-scale experiments to validate the efficiency of mRNA delivery system. In this review, we firstly provide an overview of conventional low-throughput targeting strategies. Then the latest advancements in HTS techniques for mRNA targeted delivery, encompassing optimizing structures of large-scale delivery vehicles and developing large-scale surface ligands, as well as the applications of HTS techniques in extrahepatic systemic diseases are comprehensively summarized. Moreover, we illustrate the selection of administration routes for targeted mRNA delivery. Finally, challenges in the field and potential solutions to tackle them are proposed, offering insights for future development toward mRNA targeted therapy.

Targeted delivery of anti-osteoporosis therapy: Bisphosphonate-modified nanosystems and composites

Osteoporosis (OP) constitutes a significant health concern that profoundly affects individuals' quality of life. Bisphosphonates, conventional pharmaceuticals widely employed in OP treatment, encounter limitations related to inadequate drug targeting and a short effective duration, thereby compromising their clinical efficacy. The burgeoning field of nanotechnology has witnessed the development and application of diverse functional nanosystems designed for OP treatment. Owing to the bone tissue affinity of bisphosphonates, these nanosystems are modified to address shortcomings associated with traditional drug delivery. In this review, we explore the potential of bisphosphonate-modified nanosystems as a promising strategy for addressing osteoporotic conditions. With functional modification, these nanosystems exhibit a targeted and reversible effect on osteoporotic remodeling, presenting a promising solution to enhance precision in drug delivery. The synthesis methods, physicochemical properties, and in vitro/in vivo performance of bisphosphonate-modified nanosystems are comprehensively examined in this review. Through a thorough analysis of recent advances and accomplishments in this field, we aim to provide insights into the potential applications and future directions of bisphosphonate-modified nanosystems for targeted and reversible osteoporotic remodeling.

Screening for lipid nanoparticles that modulate the immune activity of helper T cells towards enhanced antitumour activity

Lipid nanoparticles (LNPs) can be designed to potentiate cancer immunotherapy by promoting their uptake by antigen-presenting cells, stimulating the maturation of these cells and modulating the activity of adjuvants. Here we report an LNP-screening method for the optimization of the type of helper lipid and of lipid-component ratios to enhance the delivery of tumour-antigen-encoding mRNA to dendritic cells and their immune-activation profile towards enhanced antitumour activity. The method involves screening for LNPs that enhance the maturation of bone-marrow-derived dendritic cells and antigen presentation in vitro, followed by assessing immune activation and tumour-growth suppression in a mouse model of melanoma after subcutaneous or intramuscular delivery of the LNPs. We found that the most potent antitumour activity, especially when combined with immune checkpoint inhibitors, resulted from a coordinated attack by T cells and NK cells, triggered by LNPs that elicited strong immune activity in both type-1 and type-2 T helper cells. Our findings highlight the importance of optimizing the LNP composition of mRNA-based cancer vaccines to tailor antigen-specific immune-activation profiles.

Biodegradable Lipid-Modified Poly(Guanidine Thioctic Acid)s: A Fortifier of Lipid Nanoparticles to Promote the Efficacy and Safety of mRNA Cancer Vaccines

Lipid nanoparticles (LNPs)-based messenger RNA (mRNA) therapeutics have emerged with promising potentials in the fields of infectious diseases, cancer vaccines, and protein replacement therapies; however, their therapeutic efficacy and safety can still be promoted by the optimization of LNPs formulations. Unfortunately, current LNPs suffer from increased production of reactive oxygen species during translation, which leads to a decreased translation efficiency and the onset of inflammation and other side effects. Herein, we synthesize a lipid-modified poly(guanidine thioctic acid) polymer to fabricate novel LNPs for mRNA vaccines. The acquired G-LNPs significantly promote the translation efficiency of loaded mRNA and attenuate inflammation after vaccination through the elimination of reactive oxygen species that are responsible for translational inhibition and inflammatory responses. In vivo studies demonstrate the excellent antitumor efficacy of the G-LNPs@mRNA vaccine, and two-dose vaccination dramatically increases the population and infiltration of cytotoxic T cells due to the intense antitumor immune responses, thus generating superior antitumor outcomes compared with the mRNA vaccine prepared from traditional LNPs. By synergy with immune checkpoint blockade, the tumor inhibition of G-LNPs@mRNA is further boosted, indicating that G-LNPs-based mRNA vaccines will be powerful and versatile platforms to combat cancer.

Physiological Barriers and Strategies of Lipid-Based Nanoparticles for Nucleic Acid Drug Delivery

Lipid-based nanoparticles (LBNPs) are currently the most promising vehicles for nucleic acid drug (NAD) delivery. Although their clinical applications have achieved success, the NAD delivery efficiency and safety are still unsatisfactory, which are, to a large extent, due to the existence of multi-level physiological barriers in vivo. It is important to elucidate the interactions between these barriers and LBNPs, which will guide more rational design of efficient NAD vehicles with low adverse effects and facilitate broader applications of nucleic acid therapeutics. This review describes the obstacles and challenges of biological barriers to NAD delivery at systemic, organ, sub-organ, cellular, and subcellular levels. The strategies to overcome these barriers are comprehensively reviewed, mainly including physically/chemically engineering LBNPs and directly modifying physiological barriers by auxiliary treatments. Then the potentials and challenges for successful translation of these preclinical studies into the clinic are discussed. In the end, a forward look at the strategies on manipulating protein corona (PC) is addressed, which may pull off the trick of overcoming those physiological barriers and significantly improve the efficacy and safety of LBNP-based NADs delivery.

Strategies for non-viral vectors targeting organs beyond the liver

In recent years, nanoparticles have evolved to a clinical modality to deliver diverse nucleic acids. Rising interest in nanomedicines comes from proven safety and efficacy profiles established by continuous efforts to optimize physicochemical properties and endosomal escape. However, despite their transformative impact on the pharmaceutical industry, the clinical use of non-viral nucleic acid delivery is limited to hepatic diseases and vaccines due to liver accumulation. Overcoming liver tropism of nanoparticles is vital to meet clinical needs in other organs. Understanding the anatomical structure and physiological features of various organs would help to identify potential strategies for fine-tuning nanoparticle characteristics. In this Review, we discuss the source of liver tropism of non-viral vectors, present a brief overview of biological structure, processes and barriers in select organs, highlight approaches available to reach non-liver targets, and discuss techniques to accelerate the discovery of non-hepatic therapies.

From structural design to delivery: mRNA therapeutics for cancer immunotherapy

mRNA therapeutics have emerged as powerful tools for cancer immunotherapy in accordance with their superiority in expressing all sequence-known proteins in vivo. In particular, with a small dosage of delivered mRNA, antigen-presenting cells (APCs) can synthesize mutant neo-antigens and multi-antigens and present epitopes to T lymphocytes to elicit antitumor effects. In addition, expressing receptors like chimeric antigen receptor (CAR), T-cell receptor (TCR), CD134, and immune-modulating factors including cytokines, interferons, and antibodies in specific cells can enhance immunological response against tumors. With the maturation of in vitro transcription (IVT) technology, large-scale and pure mRNA encoding specific proteins can be synthesized quickly. However, the clinical translation of mRNA-based anticancer strategies is restricted by delivering mRNA into target organs or cells and the inadequate endosomal escape efficiency of mRNA. Recently, there have been some advances in mRNA-based cancer immunotherapy, which can be roughly classified as modifications of the mRNA structure and the development of delivery systems, especially the lipid nanoparticle platforms. In this review, the latest strategies for overcoming the limitations of mRNA-based cancer immunotherapies and the recent advances in delivering mRNA into specific organs and cells are summarized. Challenges and opportunities for clinical applications of mRNA-based cancer immunotherapy are also discussed.