Restoration of tumour-growth suppression in vivo via systemic nanoparticle-mediated delivery of PTEN mRNA

CREBZF mRNA nanoparticles suppress breast cancer progression through a positive feedback loop boosted by circPAPD4

BACKGROUND

Breast cancer (BC) negatively impacts the health of women worldwide. Circular RNAs (circRNAs) are a group of endogenous RNAs considered essential regulatory factor in BC tumorigenesis and progression. However, the underlying molecular mechanisms of circRNAs remain unclear.

METHODS

Expression levels of circPAPD4, miR-1269a, CREBZF, and ADAR1 in BC cell lines and tissues were measured using bioinformatics analysis, RT-qPCR, ISH, and IHC. Cell proliferation and apoptosis were measured using CCK8, EdU staining, flow cytometry, and TUNEL assays. Pearson correlation analysis, RNA pull-down, dual-luciferase reporter, and co-immunoprecipitation assays were used to explore the correlation among circPAPD4, miR-1269a, CREBZF, STAT3, and ADAR1. Effects of circPAPD4 overexpression on tumor progression were investigated using in vivo assays. Moreover, CREBZF mRNA delivered by polymeric nanoparticles (CREBZF-mRNA-NPs) was used to examine application value of our findings.

RESULTS

CircPAPD4 expression was low in BC tissues and cells. Functionally, circPAPD4 inhibited proliferation and promoted apoptosis in vitro and in vivo. Mechanistically, circPAPD4 biogenesis was regulated by ADAR1. And circPAPD4 promoted CREBZF expression by competitively binding to miR-1269a. More importantly, CREBZF promoted circPAPD4 expression by suppressing STAT3 dimerization and ADAR1 expression, revealing a novel positive feedback loop that curbed BC progression. Systematic delivery of CREBZF-mRNA-NPs effectively induced CREBZF expression and activated the positive feedback loop of circPAPD4/miR-1269a/CREBZF/STAT3/ADAR1, which might suppress BC progression in vitro and in vivo.

CONCLUSION

Our findings firstly illustrated that circPAPD4/miR-1269a/CREBZF/STAT3/ADAR1 positive feedback loop mediated BC progression, and delivering CREBZF mRNA nanoparticles suppressed BC progression in vitro and in vivo, which might provide novel insights into therapeutic strategies for breast cancer.

mRNA Vaccine Platform: mRNA Production and Delivery

Vaccination is the most efficient way to prevent infectious diseases. mRNA-based vaccines is a new approach to vaccine development, which have several very useful advantages over other types of vaccines. Since mRNA encodes only the target antigen there is no potential risk of infection as in the case with attenuated or inactivated pathogens. The mode of action of mRNA-vaccines implies that their genetic information is expressed only in the cytosol, leaving very little possibility of mRNA integration into the host's genome. mRNA-vaccines can induce specific cellular and humoral immune responses, but do not induce the antivector immune response. The mRNA-vaccine platform allows for easy target gene replacement without the need to change the production technology, which is important to address the time lag between the epidemic onset and vaccine release. The present review discusses the history of mRNA vaccines, mRNA vaccine production technology, ways to increase mRNA stability, modifications of the cap, poly(A)-tail, coding and noncoding parts of mRNA, target mRNA vaccine purification from byproducts, and delivery methods.

The Screening of Broadly Neutralizing Antibodies Targeting the SARS-CoV-2 Spike Protein by mRNA Immunization in Mice

Neutralizing antibodies (nAbs), the popular antiviral drugs used for the treatment of COVID-19, are effective in reducing viral load and hospitalization. Currently, most nAbs are screened from convalescent or vaccinated individuals through single B-cell sequencing which requires cutting-edge facilities. Moreover, owing to the rapid mutation of SARS-CoV-2, some approved nAbs are no longer effective. In the present study, we designed a new approach to acquiring broadly neutralizing antibodies (bnAbs) from mRNA-vaccinated mice. Using the flexibility and speed of mRNA vaccine preparation, we designed a chimeric mRNA vaccine and sequential immunization strategies to acquire bnAbs in mice within a short period. By comparing different vaccination orders, we found that the initially administered vaccine had a greater effect on the neutralizing potency of mouse sera. Ultimately, we screened a strain of bnAb that neutralized wild-type, Beta, and Delta SARS-CoV-2 pseudoviruses. We synthesized the mRNAs of the heavy and light chains of this antibody and verified its neutralizing potency. This study developed a new strategy to screen for bnAbs in mRNA-vaccinated mice and identified a more effective immunization strategy for inducing bnAbs, providing valuable insights for future antibody drug development.

Smart drug delivery systems to overcome drug resistance in cancer immunotherapy

Cancer immunotherapy, a therapeutic approach that inhibits tumors by activating or strengthening anti-tumor immunity, is currently an important clinical strategy for cancer treatment; however, tumors can develop drug resistance to immune surveillance, resulting in poor response rates and low therapeutic efficacy. In addition, changes in genes and signaling pathways in tumor cells prevent susceptibility to immunotherapeutic agents. Furthermore, tumors create an immunosuppressive microenvironment via immunosuppressive cells and secrete molecules that hinder immune cell and immune modulator infiltration or induce immune cell malfunction. To address these challenges, smart drug delivery systems (SDDSs) have been developed to overcome tumor cell resistance to immunomodulators, restore or boost immune cell activity, and magnify immune responses. To combat resistance to small molecules and monoclonal antibodies, SDDSs are used to co-deliver numerous therapeutic agents to tumor cells or immunosuppressive cells, thus increasing the drug concentration at the target site and improving efficacy. Herein, we discuss how SDDSs overcome drug resistance during cancer immunotherapy, with a focus on recent SDDS advances in thwarting drug resistance in immunotherapy by combining immunogenic cell death with immunotherapy and reversing the tumor immunosuppressive microenvironment. SDDSs that modulate the interferon signaling pathway and improve the efficacy of cell therapies are also presented. Finally, we discuss potential future SDDS perspectives in overcoming drug resistance in cancer immunotherapy. We believe that this review will contribute to the rational design of SDDSs and development of novel techniques to overcome immunotherapy resistance.

ROS-Responsive Nanoparticle Delivery of mRNA and Photosensitizer for Combinatorial Cancer Therapy

Messenger RNA (mRNA) therapy has shown tremendous potential for different diseases including cancer. While mRNA has been extensively used in cancer vaccine development as antigen or in cancer immunotherapy as immunomodulatory agent, the combination of mRNA therapy with photodynamic therapy has not been explored in cancer treatment. Herein, we report a reactive oxygen species (ROS)-responsive polymeric nanoparticle (NP) platform for first-in-field codelivery of mRNA and photosensitizer for effective cancer treatment. We developed ROS-responsive oligomer-based polymeric NPs and applied them to test a combination of p53 mRNA and indocyanine green (ICG). The ROS-triggered disassembly of the NPs could promote mRNA translation efficiency, whereby p53 expression induced apoptosis of lung tumor cells. Meanwhile, the released ICG could lead to generation of ROS under 808 nm laser irradiation to induce photodynamic therapy. The NP codelivery of p53 mRNA and ICG demonstrated an effective and safe anti-tumor effect in a lung cancer model.

Development and applications of mRNA treatment based on lipid nanoparticles

Nucleic acid-based therapies such as messenger RNA have the potential to revolutionize modern medicine and enhance the performance of existing pharmaceuticals. The key challenges of mRNA-based therapies are delivering the mRNA safely and effectively to the target tissues and cells and controlling its release from the delivery vehicle. Lipid nanoparticles (LNPs) have been widely studied as drug carriers and are considered to be state-of-the-art technology for nucleic acid delivery. In this review, we begin by presenting the advantages and mechanisms of action of mRNA therapeutics. Then we discuss the design of LNP platforms based on ionizable lipids and the applications of mRNA-LNP vaccines for prevention of infectious diseases and for treatment of cancer and various genetic diseases. Finally, we describe the challenges and future prospects of mRNA-LNP therapeutics.

Cancer nanomedicine toward clinical translation: Obstacles, opportunities, and future prospects

With the integration of nanotechnology into the medical field at large, great strides have been made in the development of nanomedicines for tackling different diseases, including cancers. To date, various cancer nanomedicines have demonstrated success in preclinical studies, improving therapeutic outcomes, prolonging survival, and/or decreasing side effects. However, the translation from bench to bedside remains challenging. While a number of nanomedicines have entered clinical trials, only a few have been approved for clinical applications. In this review, we highlight the most recent progress in cancer nanomedicine, discuss current clinical advances and challenges for the translation of cancer nanomedicines, and provide our viewpoints on accelerating clinical translation. We expect this review to benefit the future development of cancer nanotherapeutics specifically from the clinical perspective.

mRNA delivery in cancer immunotherapy

Messenger RNA (mRNA) has drawn much attention in the medical field. Through various treatment approaches including protein replacement therapies, gene editing, and cell engineering, mRNA is becoming a potential therapeutic strategy for cancers. However, delivery of mRNA into targeted organs and cells can be challenging due to the unstable nature of its naked form and the low cellular uptake. Therefore, in addition to mRNA modification, efforts have been devoted to developing nanoparticles for mRNA delivery. In this review, we introduce four categories of nanoparticle platform systems: lipid, polymer, lipid-polymer hybrid, and protein/peptide-mediated nanoparticles, together with their roles in facilitating mRNA-based cancer immunotherapies. We also highlight promising treatment regimens and their clinical translation.

mRNA-Based Therapeutics in Cancer Treatment

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

Nanobiotechnology-Enabled mRNA Stabilization

mRNA technology has attracted enormous interest due to its great therapeutic potential. Strategies that can stabilize fragile mRNA molecules are crucial for their widespread applications. There are numerous reviews on mRNA delivery, but few focus on the underlying causes of mRNA instability and how to tackle the instability issues. Herein, the recent progress in nanobiotechnology-enabled strategies for stabilizing mRNA and better delivery is reviewed. First, factors that destabilize mRNA are introduced. Second, nanobiotechnology-enabled strategies to stabilize mRNA molecules are reviewed, including molecular and nanotechnology approaches. The impact of formulation processing on mRNA stability and shelf-life, including freezing and lyophilization, are also briefly discussed. Lastly, our perspectives on challenges and future directions are presented. This review may provide useful guidelines for understanding the structure-function relationship and the rational design of nanobiotechnology for mRNA stability enhancement and mRNA technology development.

A Polymeric Nanoparticle Formulation for Targeted mRNA Delivery to Fibroblasts

Messenger RNA (mRNA)-based therapies offer enhanced control over the production of therapeutic proteins for many diseases. Their clinical implementation warrants formulations capable of delivering them safely and effectively to target sites. Owing to their chemical versatility, polymeric nanoparticles can be designed by combinatorial synthesis of different ionizable, cationic, and aromatic moieties to modulate cell targeting, using inexpensive formulation steps. Herein, 152 formulations are evaluated by high-throughput screening using a reporter fibroblast model sensitive to functional delivery of mRNA encoding Cre recombinase. Using in vitro and in vivo models, a polymeric nanoformulation based on the combination of 3 specific monomers is identified to transfect fibroblasts much more effectively than other cell types populating the skin, with superior performance than lipid-based transfection agents in the delivery of Cas9 mRNA and guide RNA. This tropism can be explained by receptor-mediated endocytosis, involving CD26 and FAP, which are overexpressed in profibrotic fibroblasts. Structure-activity analysis reveals that efficient mRNA delivery required the combination of high buffering capacity and low mRNA binding affinity for rapid release upon endosomal escape. These results highlight the use of high-throughput screening to rapidly identify chemical features towards the design of highly efficient mRNA delivery systems targeting fibrotic diseases.

Safe and Effective Delivery of mRNA Using Modified PEI-Based Lipopolymers

Chemically modified mRNA (modRNA) has proven to be a versatile tool for the treatment of various cancers and infectious diseases due to recent technological advancements. However, a safe and effective delivery system to overcome the complex extracellular and intracellular barriers is required in order to achieve higher therapeutic efficacy and broaden clinical applications. Here, we explored All-Fect and Leu-Fect C as novel transfection reagents derived from lipopolymers, which demonstrated excellent biocompatibility, efficient delivery capabilities, and a robust ability to escape the lysosomes. These properties directly increase mRNA stability by preventing mRNA degradation by nucleases and simultaneously promote efficient gene translation in vitro and in vivo. The modRNA delivered with lipopolymer vectors sustained effective transfection in mouse hearts following direct intramyocardial injection, as well as in major organs (liver and spleen) after systemic administration. No observable immune reactions or systemic toxicity were detected following the systemic administration of lipopolymer-mRNA complexes to additional solid organs. This study identified commercial reagents for the effective delivery of modRNA and may help facilitate the advancement of gene-based interventions involving the safe and effective delivery of nucleic acid drug substances.

Protein Transduction Domain-Mediated Delivery of Recombinant Proteins and In Vitro Transcribed mRNAs for Protein Replacement Therapy of Human Severe Genetic Mitochondrial Disorders: The Case of Sco2 Deficiency

Mitochondrial disorders represent a heterogeneous group of genetic disorders with variations in severity and clinical outcomes, mostly characterized by respiratory chain dysfunction and abnormal mitochondrial function. More specifically, mutations in the human SCO2 gene, encoding the mitochondrial inner membrane Sco2 cytochrome c oxidase (COX) assembly protein, have been implicated in the mitochondrial disorder fatal infantile cardioencephalomyopathy with COX deficiency. Since an effective treatment is still missing, a protein replacement therapy (PRT) was explored using protein transduction domain (PTD) technology. Therefore, the human recombinant full-length mitochondrial protein Sco2, fused to TAT peptide (a common PTD), was produced (fusion Sco2 protein) and successfully transduced into fibroblasts derived from a SCO2/COX-deficient patient. This PRT contributed to effective COX assembly and partial recovery of COX activity. In mice, radiolabeled fusion Sco2 protein was biodistributed in the peripheral tissues of mice and successfully delivered into their mitochondria. Complementary to that, an mRNA-based therapeutic approach has been more recently considered as an innovative treatment option. In particular, a patented, novel PTD-mediated IVT-mRNA delivery platform was developed and applied in recent research efforts. PTD-IVT-mRNA of full-length SCO2 was successfully transduced into the fibroblasts derived from a SCO2/COX-deficient patient, translated in host ribosomes into a nascent chain of human Sco2, imported into mitochondria, and processed to the mature protein. Consequently, the recovery of reduced COX activity was achieved, thus suggesting the potential of this mRNA-based technology for clinical translation as a PRT for metabolic/genetic disorders. In this review, such research efforts will be comprehensibly presented and discussed to elaborate their potential in clinical application and therapeutic usefulness.

Inhibition of Wnt Signaling in Colon Cancer Cells via an Oral Drug that Facilitates TNIK Degradation

We have synthesized an oxetane derivative of the benzimidazole compound mebendazole (OBD9) with enhanced solubility and strong anticancer activity in multiple types of cancer cells, especially colorectal cancer. In this report, we provide evidence that OBD9 suppresses colorectal cancer growth by interfering with the Wnt signaling pathway, a main driver of cell growth in colorectal cancer. Specifically, we find that OBD9 induces autophagic degradation of TNIK (traf2 and Nck-interacting kinase), which promotes T-cell factor-4 (TCF4)/beta-catenin-mediated gene expression. Thus, OBD9 as a TNIK inhibitor blocks Wnt/beta-catenin signaling at the final step of transcriptional activation. We suggest that OBD9 provides a potential novel autophagy-mediated, Wnt-damping therapeutic strategy for the treatment of colorectal cancer.

Glioblastoma immuno-endothelial multicellular microtissue as a 3D in vitro evaluation tool of anti-cancer nano-therapeutics

Despite being the most prevalent and lethal type of adult brain cancer, glioblastoma (GBM) remains intractable. Promising anti-GBM nanoparticle (NP) systems have been developed to improve the anti-cancer performance of difficult-to-deliver therapeutics, with particular emphasis on tumor targeting strategies. However, current disease modeling toolboxes lack close-to-native in vitro models that emulate GBM microenvironment and bioarchitecture, thus partially hindering translation due to poorly predicted clinical responses. Herein, human GBM heterotypic multicellular tumor microtissues (MCTMs) are generated through high-throughput 3D modeling of U-251 MG tumor cells, tissue differentiated macrophages isolated from peripheral monocytes, and brain microvascular primary endothelial cells. GBM MCTMs mimicked tumor spatial organization, extracellular matrix production and necrosis areas. The bioactivity of a model drug, docetaxel (DTX), and of tumor-targeted DTX-loaded polymeric NPs with a surface L-Histidine moiety (H-NPs), were assessed in the MCTMs. MCTMs cell uptake and anti-proliferative effect was 8- and 3-times higher for H-NPs, respectively, compared to the non-targeted NPs and to free DTX. H-NPs provided a decrease of MCTMs anti-inflammatory M2-macrophages, while increasing their pro-inflammatory M1 counterparts. Moreover, H-NPs showed a particular biomolecular signature through reduced secretion of an array of medium cytokines (IFN-γ, IL-1β, IL-1Ra, IL-6, IL-8, TGF-β). Overall, MCTMs provide an in vitro biomimetic model to recapitulate key cellular and structural features of GBM and improve in vivo drug response predictability, fostering future clinical translation of anti-GBM nano-therapeutic strategies.

Lipid Nanoparticle Delivery of Chemically Modified NGFR100W mRNA Alleviates Peripheral Neuropathy

Messenger RNA (mRNA) carries genetic instructions to the cell machinery for the transient production of antigens or therapeutic proteins and shows enormous potential in vaccine development, cancer immunotherapy, protein replacement therapy, and genome engineering. Here, the synthesis of chemically modified nerve growth factor mutant (NGF^R100W ) mRNA through in vitro transcription is described. After the replacement of the original signal peptide sequence with the Ig Kappa leader sequence, codon-optimized NGF^R100W mRNA yielded high secretion of mature NGF^R100W , which promotes axon growth in PC12 cells. Using lipid nanoparticle (LNP)-delivery of N1-methylpseudouridine-modified mRNA in mice, NGF^R100W -mRNA-LNPs result in the successful expression of NGF^R100W protein, which significantly reduces nociceptive activity compared to that of NGF^WT . This indicates that NGF^R100W derived from exogenous mRNA elicited "painless" neuroprotective activity. Additionally, the therapeutic value of NGF^R100W mRNA is established in a paclitaxel-induced peripheral neuropathy model by demonstrating the rapid recovery of intraepidermal nerve fibers. The results show that in vitro-transcribed mRNA has significant flexibility in sequence design and fast in vivo functional validation of target proteins. Furthermore, the results highlight the therapeutic potential of mRNA as a supplement to beneficial proteins for preventing or reversing some chronic medical conditions, such as peripheral neuropathy.

Excipient-Free Ionizable Polyester Nanoparticles for Lung-Selective and Innate Immune Cell Plasmid DNA and mRNA Transfection

Extrahepatic nucleic acid delivery using polymers typically requires the synthesis and purification of custom monomers, post-synthetic modifications, and incorporation of additional excipients to augment their stability, endosomal escape, and in vivo effectiveness. Here, we report the development of a single-component and excipient-free, polyester-based nucleic acid delivery nanoparticle platform comprising ionizable N-methyldiethanolamine (MDET) and various hydrophobic alkyl diols (Cp) that achieves lung-selective nucleic acid transfection in vivo. PolyMDET and polyMDET-Cp polyplexes displayed high serum and enzymatic stability, while delivering pDNA or mRNA to "hard-to-transfect" innate immune cells. PolyMDET-C4 and polyMDET-C6 mediated high protein expression in lung alveolar macrophages and dendritic cells without inducing tissue damage or systemic inflammatory responses. Improved strategies using readily available starting materials to produce a simple, excipient-free, non-viral nucleic acid delivery platform with lung-selective and innate immune cell tropism has the potential to expedite clinical deployment of polymer-based genetic medicines.

Modulating the expression of tumor suppressor genes using activating oligonucleotide technologies as a therapeutic approach in cancer

Tumor suppressor genes (TSGs) are frequently downregulated in cancer, leading to dysregulation of the pathways that they control. The continuum model of tumor suppression suggests that even subtle changes in TSG expression, for example, driven by epigenetic modifications or copy number alterations, can lead to a loss of gene function and a phenotypic effect. This approach to exploring tumor suppression provides opportunities for alternative therapies that may be able to restore TSG expression toward normal levels, such as oligonucleotide therapies. Oligonucleotide therapies involve the administration of exogenous nucleic acids to modulate the expression of specific endogenous genes. This review focuses on two types of activating oligonucleotide therapies, small-activating RNAs and synthetic mRNAs, as novel methods to increase the expression of TSGs in cancer.

Nanoparticles and Nanomaterials-Based Recent Approaches in Upgraded Targeting and Management of Cancer: A Review

Along with the extensive improvement in tumor biology research and different therapeutic developments, cancer remains a dominant and deadly disease. Tumor heterogeneity, systemic toxicities, and drug resistance are major hurdles in cancer therapy. Chemotherapy, radiotherapy, phototherapy, and surgical therapy are some prominent areas of cancer treatment. During chemotherapy for cancer, chemotherapeutic agents are distributed all over the body and also damage normal cells. With advancements in nanotechnology, nanoparticles utilized in all major areas of cancer therapy offer the probability to advance drug solubility, and stability, extend drug half-lives in plasma, reduce off-target effects, and quintessence drugs at a target site. The present review compiles the use of different types of nanoparticles in frequently and recently applied therapeutics of cancer therapy. A recent area of cancer treatment includes cancer stem cell therapy, DNA/RNA-based immunomodulation therapy, alteration of the microenvironment, and cell membrane-mediated biomimetic approach. Biocompatibility and bioaccumulation of nanoparticles is the major impediment in nano-based therapy. More research is required to develop the next generation of nanotherapeutics with the incorporation of new molecular entities, such as kinase inhibitors, siRNA, mRNA, and gene editing. We assume that nanotherapeutics will dramatically improve patient survival, move the model of cancer treatment, and develop certainty in the foreseeable future.

Lipid Nanoparticle Composition Drives mRNA Delivery to the Placenta

Ionizable lipid nanoparticles (LNPs) have gained attention as mRNA delivery platforms for vaccination against COVID-19 and for protein replacement therapies. LNPs enhance mRNA stability, circulation time, cellular uptake, and preferential delivery to specific tissues compared to mRNA with no carrier platform. However, LNPs have yet to be developed for safe and effective mRNA delivery to the placenta as a method to treat placental dysfunction. Here, we develop LNPs that enable high levels of mRNA delivery to trophoblasts in vitro and to the placenta in vivo with no toxicity. We conducted a Design of Experiments to explore how LNP composition, including the type and molar ratio of each lipid component, drives trophoblast and placental delivery. Our data revealed that a specific combination of ionizable lipid and phospholipid in the LNP design yields high transfection efficiency in vitro . Further, we present one LNP platform that exhibits highest delivery of placental growth factor mRNA to the placenta in pregnant mice, which demonstrates induced protein synthesis and secretion of a therapeutic protein. Lastly, our high-performing LNPs have no toxicity to both the pregnant mice and fetuses. Our results demonstrate the feasibility of LNPs as a platform for mRNA delivery to the placenta. Our top LNPs may provide a therapeutic platform to treat diseases that originate from placental dysfunction during pregnancy.

Erythrocyte Membrane-Camouflaged Aggregation-Induced Emission Nanoparticles for Fetal Intestinal Maturation Assessment

Assessment of fetal maturity is essential for timely termination of pregnancy, especially in pregnant women with pregnancy complications. However, there is a lack of methods to assess the maturity of fetal intestinal function. Here, we constructed erythrocyte membrane-camouflaged aggregation-induced emission (AIE) nanoparticles. Nanocore is formed using a hollow mesoporous silicon nanobox (HMSN) of different particle sizes loaded with AIE luminogens -PyTPA (P), which are then co-extruded with erythrocyte membranes (M) to construct M@HMSN@P. The 100 nm M@HMSN@P has a more effective cellular uptake efficiency in vitro and in vivo. Swallowing and intestinal function in fetal mice mature with the increase in gestational age. After intrauterine injection of M@HMSN@P, they were swallowed and absorbed by fetal mice, and their swallowed and absorbed amount was positively correlated with the gestational age with a correlation coefficient of 0.9625. Using the M@HMSN@P (fluorescence intensity) in fetal mice, the gestational age can be imputed, and the difference between this imputed gestational age and the actual gestational age is less than 1 day. Importantly, M@HMSN@P has no side effect on the health status of pregnant and fetal mice, showing good biocompatibility. In conclusion, we constructed M@HMSN@P nanoparticles with different particle sizes and confirmed that the smaller size M@HMSN@P has more efficient absorption efficiency and it can assess fetal intestinal maturity by the intensity of the fluorescence signal.

The landscape of mRNA nanomedicine

Messenger RNA (mRNA) is an emerging class of therapeutic agent for the prevention and treatment of a wide range of diseases. The recent success of the two highly efficacious mRNA vaccines produced by Moderna and Pfizer-BioNTech to protect against COVID-19 highlights the huge potential of mRNA technology for revolutionizing life science and medical research. Challenges related to mRNA stability and immunogenicity, as well as in vivo delivery and the ability to cross multiple biological barriers, have been largely addressed by recent progress in mRNA engineering and delivery. In this Review, we present the latest advances and innovations in the growing field of mRNA nanomedicine, in the context of ongoing clinical translation and future directions to improve clinical efficacy.

Nanoparticles (NPs)-mediated systemic mRNA delivery to reverse trastuzumab resistance for effective breast cancer therapy

Monoclonal antibody-based therapy has achieved great success and is now one of the most crucial therapeutic modalities for cancer therapy. The first monoclonal antibody authorized for treating human epidermal growth receptor 2 (HER2)-positive breast cancer is trastuzumab. However, resistance to trastuzumab therapy is frequently encountered and thus significantly restricts the therapeutic outcomes. To address this issue, tumor microenvironment (TME) pH-responsive nanoparticles (NPs) were herein developed for systemic mRNA delivery to reverse the trastuzumab resistance of breast cancer (BCa). This nanoplatform is comprised of a methoxyl-poly (ethylene glycol)-b-poly (lactic-co-glycolic acid) copolymer with a TME pH-liable linker (Meo-PEG-Dlink _m -PLGA) and an amphiphilic cationic lipid that can complex PTEN mRNA via electrostatic interaction. When the long-circulating mRNA-loaded NPs build up in the tumor after being delivered intravenously, they could be efficiently internalized by tumor cells due to the TME pH-triggered PEG detachment from the NP surface. With the intracellular mRNA release to up-regulate PTEN expression, the constantly activated PI3K/Akt signaling pathway could be blocked in the trastuzumab-resistant BCa cells, thereby resulting in the reversal of trastuzumab resistance and effectively suppress the development of BCa.

Chemically modified in-vitro-transcribed mRNA encoding thrombopoietin stimulates thrombopoiesis in mice

The use of messenger RNA (mRNA) enables the transient production of therapeutic proteins with stable and predictable translational kinetics and without the risk of insertional mutagenesis. Recent findings highlight the enormous potential of mRNA-based therapeutics. Here, we describe the synthesis of chemically modified thrombopoietin (TPO) mRNA through in vitro transcription and in vivo delivery via lipid nanoparticles (LNPs). After delivery of TPO mRNA in mice, compared with normal physiological values, plasma TPO protein levels increased over 1000-fold in a dose-dependent manner. Moreover, through a single intravenous dose of TPO mRNA-loaded LNPs, both reticulated and total platelet count increased significantly in mice, demonstrating that TPO protein derived from the exogenous mRNA was able to maintain normal activity. Submicrogram quantity of N₁-methylpseudouridine-modified TPO mRNA showed a similar effect in promoting thrombopoiesis as that by the TPO receptor agonist romiplostim. In addition, a therapeutic value was established in anti-GPIbα (CD42b) antibody-induced thrombocytopenia mouse models that showed a fast recovery of platelet count. Our study demonstrated chemically modified in-vitro-transcribed TPO mRNA as a potentially safe therapeutic intervention to stimulate thrombopoiesis.

The potential application of branch-PCR assembled PTEN gene nanovector in lung cancer gene therapy

Gene therapy offers an alternative and promising avenue to lung cancer treatment. Here, we used dibenzocyclooctyne (DBCO)-branched primers to construct a kind of PTEN gene nanovector (NP-PTEN) through branch-PCR. NP-PTEN showed the nanoscale structure with the biocompatible size (84.7 ± 11.2 nm) and retained the improved serum stability compared to linear DNA. When transfected into NCI-H1299 cancer cells, NP-PTEN could overexpress PTEN protein to restore PTEN function through the deactivation of PI3K-AKT-mTOR signaling pathway to inhibit cell proliferation and induce cell apoptosis. The apoptosis rate of NCI-H1299 cancer cells could reach up to 54.5% ± 4.6% when the transfection concentration of NP-PTEN was 4.0 μg/mL. In mice bearing NCI-H1299 tumor xenograft intratumorally administrated with NP-PTEN, the average tumor volume and tumor weight was separately reduced by 61.7% and 63.9% compared with the PBS group on the 18 th day of administration. The anticancer efficacy of NP-PTEN in NCI-H1299 tumor xenograft suggested the promising therapeutic potential of this branch-PCR assembled PTEN gene nanovectors in lung cancer gene therapy and also provided more opportunities to introduce two or more tumor suppressor genes as the all-in-one gene nanovectors for multiple gene-based cancer gene therapy.

Gene therapy to enhance angiogenesis in chronic wounds

Skin injuries and chronic non-healing wounds are one of the major global burdens on the healthcare systems worldwide due to their difficult-to-treat nature, associated co-morbidities, and high health care costs. Angiogenesis has a pivotal role in the wound-healing process, which becomes impaired in many chronic non-healing wounds, leading to several healing disorders and complications. Therefore, induction or promotion of angiogenesis can be considered a promising approach for healing of chronic wounds. Gene therapy is one of the most promising upcoming strategies for the treatment of chronic wounds. It can be classified into three main approaches: gene augmentation, gene silencing, and gene editing. Despite the increasing number of encouraging results obtained using nucleic acids (NAs) as active pharmaceutical ingredients of gene therapy, efficient delivery of NAs to their site of action (cytoplasm or nucleus) remains a key challenge. Selection of the right therapeutic cargo and delivery methods is crucial for a favorable prognosis of the healing process. This article presents an overview of gene therapy and non-viral delivery methods for angiogenesis induction in chronic wounds.

Lipid nanoparticle-based mRNA vaccines in cancers: Current advances and future prospects

Messenger RNA (mRNA) vaccines constitute an emerging therapeutic method with the advantages of high safety and efficiency as well as easy synthesis; thus, they have been widely used in various human diseases, especially in malignant cancers. However, the mRNA vaccine technology has some limitations, such as instability and low transitive efficiency in vivo, which greatly restrict its application. The development of nanotechnology in the biomedical field offers new strategies and prospects for the early diagnosis and treatment of human cancers. Recent studies have demonstrated that Lipid nanoparticle (LNP)-based mRNA vaccines can address the poor preservation and targeted inaccuracy of mRNA vaccines. As an emerging cancer therapy, mRNA vaccines potentially have broad future applications. Unlike other treatments, cancer mRNA vaccines provide specific, safe, and tolerable treatments. Preclinical studies have used personalized vaccines to demonstrate the anti-tumor effect of mRNA vaccines in the treatment of various solid tumors, including colorectal and lung cancer, using these in a new era of therapeutic cancer vaccines. In this review, we have summarized the latest applications and progress of LNP-based mRNA vaccines in cancers, and discussed the prospects and limitations of these fields, thereby providing novel strategies for the targeted therapy of cancers.

Application of mRNA Technology in Cancer Therapeutics

mRNA-based therapeutics pose as promising treatment strategies for cancer immunotherapy. Improvements in materials and technology of delivery systems have helped to overcome major obstacles in generating a sufficient immune response required to fight a specific type of cancer. Several in vivo models and early clinical studies have suggested that various mRNA treatment platforms can induce cancer-specific cytolytic activity, leading to numerous clinical trials to determine the optimal method of combinations and sequencing with already established agents in cancer treatment. Nevertheless, further research is required to optimize RNA stabilization, delivery platforms, and improve clinical efficacy by interacting with the tumor microenvironment to induce a long-term antitumor response. This review provides a comprehensive summary of the available evidence on the recent advances and efforts to overcome existing challenges of mRNA-based treatment strategies, and how these efforts play key roles in offering perceptive insights into future considerations for clinical application.

mRNA Vaccines Against SARS‐CoV‐2 Variants Delivered by Lipid Nanoparticles Based on Novel Ionizable Lipids

SARS‐CoV‐2 variants are now still challenging all the approved vaccines, including mRNA vaccines. There is an urgent need to develop new generation mRNA vaccines with more powerful efficacy and better safety against SARS‐CoV‐2 variants. In this study, a new set of ionizable lipids named 4N4T are constructed and applied to form novel lipid nanoparticles called 4N4T‐LNPs. Leading 4N4T‐LNPs exhibit much higher mRNA translation efficiency than the approved SM‐102‐LNPs. To test the effectiveness of the novel delivery system, the DS mRNA encoding the full‐length S protein of the SARS‐CoV‐2 variant is synthesized and loaded in 4N4T‐LNPs. The obtained 4N4T‐DS mRNA vaccines successfully trigger robust and durable humoral immune responses against SARS‐CoV‐2 and its variants including Delta and Omicron. Importantly, the novel vaccines have higher RBD‐specific IgG titers and neutralizing antibody titers than SM‐102‐based DS mRNA vaccine. Besides, for the first time, the types of mRNA vaccine‐induced neutralizing antibodies are found to be influenced by the chemical structure of ionizable lipids. 4N4T‐DS mRNA vaccines also induce strong Th1‐skewed T cell responses and have good safety. This work provides a novel vehicle for mRNA delivery that is more effective than the approved LNPs and shows its application in vaccines against SARS‐CoV‐2 variants.

Application Perspectives of Nanomedicine in Cancer Treatment

Cancer is a disease that seriously threatens human health. Based on the improvement of traditional treatment methods and the development of new treatment modes, the pattern of cancer treatment is constantly being optimized. Nanomedicine plays an important role in these evolving tumor treatment modalities. In this article, we outline the applications of nanomedicine in three important tumor-related fields: chemotherapy, gene therapy, and immunotherapy. According to the current common problems, such as poor targeting of first-line chemotherapy drugs, easy destruction of nucleic acid drugs, and common immune-related adverse events in immunotherapy, we discuss how nanomedicine can be combined with these treatment modalities, provide typical examples, and summarize the advantages brought by the application of nanomedicine.

Recent advances in mRNA-LNP therapeutics: immunological and pharmacological aspects

In the last decade, the development of messenger RNA (mRNA) therapeutics by lipid nanoparticles (LNP) leads to facilitate clinical trial recruitment, which improves the efficacy of treatment modality to a large extent. Although mRNA-LNP vaccine platforms for the COVID-19 pandemic demonstrated high efficiency, safety and adverse effects challenges due to the uncontrolled immune responses and inappropriate pharmacological interventions could limit this tremendous efficacy. The current study reveals the interplay of immune responses with LNP compositions and characterization and clarifies the interaction of mRNA-LNP therapeutics with dendritic, macrophages, neutrophile cells, and complement. Then, pharmacological profiles for mRNA-LNP delivery, including pharmacokinetics and cellular trafficking, were discussed in detail in cancer types and infectious diseases. This review study opens a new and vital landscape to improve multidisciplinary therapeutics on mRNA-LNP through modulation of immunopharmacological responses in clinical trials.

Clinical progress of nanomedicine-based RNA therapies

The clinical application of nanoparticles (NPs) to deliver RNA for therapy has progressed rapidly since the FDA approval of Onpattro® in 2018 for the treatment of polyneuropathy associated with hereditary transthyretin amyloidosis. The emergency use authorization or approval and widespread global use of two mRNA-NP based vaccines developed by Moderna Therapeutics Inc. and Pfizer-BioNTech in 2021 has highlighted the translatability of NP technology for RNA delivery. Furthermore, in clinical trials, a wide variety of NP formulations have been found to extend the half-life of RNA molecules such as microRNA, small interfering RNA, and messenger RNA, with limited safety issues. In this review, we discuss the NP formulations that are already used in the clinic to deliver therapeutic RNA and highlight examples of RNA-NPs which are currently under evaluation for human use. We also detail NP formulations that failed to progress through clinical trials, in hopes of guiding future successful translation of nanomedicine-based RNA therapeutics into the clinic.

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

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

Ocular Nanomedicine

Intrinsic shortcomings associated with conventional therapeutic strategies often compromise treatment efficacy in clinical ophthalmology, prompting the rapid development of versatile alternatives for satisfactory diagnostics and therapeutics. Given advances in material science, nanochemistry, and nanobiotechnology, a broad spectrum of functional nanosystems has been explored to satisfy the extensive requirements of ophthalmologic applications. In the present review, the recent progress in nanosystems, both conventional and emerging nanomaterials in ophthalmology from state-of-the-art studies, are comprehensively examined and the role of their fundamental physicochemical properties in bioavailability, tissue penetration, biodistribution, and elimination after interacting with the ophthalmologic microenvironment emphasized. Furthermore, along with the development of surface engineering of nanomaterials, emerging theranostic methodologies are promoted as potential alternatives for multipurpose ocular applications, such as emerging biomimetic ophthalmology (e.g., smart electrochemical eye), thus provoking a holistic review of "ocular nanomedicine." By affording insight into challenges encountered by ocular nanomedicine and further highlighting the direction of future studies, this review provides an incentive for enriching ocular nanomedicine-based fundamental research and future clinical translation.

Emerging vaccine nanotechnology: From defense against infection to sniping cancer

Looking retrospectively at the development of humanity, vaccination is an unprecedented medical landmark that saves lives by harnessing the human immune system. During the ongoing coronavirus disease 2019 (COVID-19) pandemic, vaccination is still the most effective defense modality. The successful clinical application of the lipid nanoparticle-based Pfizer/BioNTech and Moderna mRNA COVID-19 vaccines highlights promising future of nanotechnology in vaccine development. Compared with conventional vaccines, nanovaccines are supposed to have advantages in lymph node accumulation, antigen assembly, and antigen presentation; they also have, unique pathogen biomimicry properties because of well-organized combination of multiple immune factors. Beyond infectious diseases, vaccine nanotechnology also exhibits considerable potential for cancer treatment. The ultimate goal of cancer vaccines is to fully mobilize the potency of the immune system as a living therapeutic to recognize tumor antigens and eliminate tumor cells, and nanotechnologies have the requisite properties to realize this goal. In this review, we summarize the recent advances in vaccine nanotechnology from infectious disease prevention to cancer immunotherapy and highlight the different types of materials, mechanisms, administration methods, as well as future perspectives.

Emerging mRNA technologies: delivery strategies and biomedical applications

The great success achieved by the two highly-effective messenger RNA (mRNA) vaccines during the COVID-19 pandemic highlights the great potential of mRNA technology. Through the evolution of mRNA technology, chemistry has played an important role from mRNA modification to the synthesis of mRNA delivery platforms, which allows various applications of mRNA to be achieved both in vitro and in vivo. In this tutorial review, we provide a summary and discussion on the significant progress of emerging mRNA technologies, as well as the underlying chemical designs and principles. Various nanoparticle (NP)-based delivery strategies including protein-mRNA complex, lipid-based carriers, polymer-based carriers, and hybrid carriers for the efficient delivery of mRNA molecules are presented. Furthermore, typical mRNA delivery platforms for various biomedical applications (e.g., functional protein expression, vaccines, cancer immunotherapy, and genome editing) are highlighted. Finally, our insights into the challenges and future development towards clinical translation of these mRNA technologies are provided.

Nanodelivery of nucleic acids

There is growing need for a safe, efficient, specific and non-pathogenic means for delivery of gene therapy materials. Nanomaterials for nucleic acid delivery offer an unprecedented opportunity to overcome these drawbacks; owing to their tunability with diverse physico-chemical properties, they can readily be functionalized with any type of biomolecules/moieties for selective targeting. Nucleic acid therapeutics such as antisense DNA, mRNA, small interfering RNA (siRNA) or microRNA (miRNA) have been widely explored to modulate DNA or RNA expression Strikingly, gene therapies combined with nanoscale delivery systems have broadened the therapeutic and biomedical applications of these molecules, such as bioanalysis, gene silencing, protein replacement and vaccines. Here, we overview how to design smart nucleic acid delivery methods, which provide functionality and efficacy in the layout of molecular diagnostics and therapeutic systems. It is crucial to outline some of the general design considerations of nucleic acid delivery nanoparticles, their extraordinary properties and the structure-function relationships of these nanomaterials with biological systems and diseased cells and tissues.

Inhaled mRNA Nanoformulation with Biogenic Ribosomal Protein Reverses Established Pulmonary Fibrosis in a Bleomycin-Induced Murine Model

Idiopathic pulmonary fibrosis (IPF), a lethal respiratory disease with few treatment options, occurs due to repetitive microinjuries to alveolar epithelial cells (AECs) and progresses with an overwhelming deposition of extracellular matrix (ECM), ultimately resulting in fibrotic scars and destroyed the alveolar architecture. Here, an inhaled ribosomal protein-based mRNA nanoformulation is reported for clearing the intrapulmonary ECM and re-epithelializing the disrupted alveolar epithelium, thereby reversing established fibrotic foci in IPF. The nanoformulation is sequentially assembled by a ribosomal protein-condensed mRNA core, a bifunctional peptide-modified corona and keratinocyte growth factor (KGF) with a PEGylated shielding shell. When inhaled via a nebulizer, the nanoformulations carried by microdrops are deposited in the alveoli, and penetrate into fibrotic foci, where the outer KGFs are detached after matrix metalloproteinase 2 (MMP2) triggering. The RGD motif-grafted cores then expose and specifically target the integrin-elevated cells for the intracellular delivery of mRNA. Notably, repeated inhalation of the nanoformulations accelerates the clearance of locoregional collagen by boosting the intralesional expression of MMP13 and alveolar re-epithelialization mediated by KGFs, which synergistically ameliorates the lung function of a bleomycin-induced murine model. Therefore, this work provides an alternative mRNA-inhalation delivery strategy, which shows great potential for the treatment of IPF.

RNA cancer nanomedicine: nanotechnology-mediated RNA therapy

It has been demonstrated that RNA molecules-mRNA, siRNA, microRNA, and sgRNA-regulate cancer-specific genes, and therefore, RNA-based therapeutics can suppress tumor progression and metastasis by selectively upregulating and silencing these genes. However, the innate defense mechanisms (e.g., exonucleases and RNases) involving the human immune system catalyze the degradation of exogenous RNAs. Thus, nonviral nanoparticles have been employed to deliver therapeutic RNAs for effective cancer gene therapy. In this minireview, we highlight efforts in the past decade to deliver therapeutic RNAs for cancer therapy using novel nanoparticles. Specifically, we review nanoparticles, including lipid, polymer, inorganic, and biomimetic materials, which have been employed to deliver therapeutic RNAs and evoke tumor suppressing responses. Finally, we discuss the challenges and considerations that may accelerate the clinical translation of nanotechnology-mediated RNA therapy.

mRNA cancer vaccines: Advances, trends and challenges

Patients exhibit good tolerance to messenger ribonucleic acid (mRNA) vaccines, and the choice of encoded molecules is flexible and diverse. These vaccines can be engineered to express full-length antigens containing multiple epitopes without major histocompatibility complex (MHC) restriction, are relatively easy to control and can be rapidly mass produced. In 2021, the U.S. Food and Drug Administration (FDA) approved the first mRNA-based coronavirus disease 2019 (COVID-19) vaccine produced by Pfizer and BioNTech, which has generated enthusiasm for mRNA vaccine research and development. Based on the above characteristics and the development of mRNA vaccines, mRNA cancer vaccines have become a research hotspot and have undergone rapid development, especially in the last five years. This review analyzes the advances in mRNA cancer vaccines from various perspectives, including the selection and expression of antigens/targets, the application of vectors and adjuvants, different administration routes, and preclinical evaluation, to reflect the trends and challenges associated with these vaccines.

Messenger RNA vaccines for cancer immunotherapy: progress promotes promise

The COVID-19 pandemic has elevated mRNA vaccines to global recognition due to their unprecedented success rate in protecting against a deadly virus. This international success is underscored by the remarkable versatility, favorable immunogenicity, and overall safety of the mRNA platform in diverse populations. Although mRNA vaccines have been studied in preclinical models and patients with cancer for almost three decades, development has been slow. The recent technological advances responsible for the COVID-19 vaccines have potential implications for successfully adapting this vaccine platform for cancer therapeutics. Here we discuss the lessons learned along with the chemical, biologic, and immunologic adaptations needed to optimize mRNA technology to successfully treat cancers.

Synthesis of siRNA nanoparticles to silence plaque-destabilizing gene in atherosclerotic lesional macrophages

Macrophages in atherosclerotic lesions promote plaque progression and are an attractive therapeutic target in cardiovascular research. Here we present a protocol for synthesis of small interfering RNA (siRNA) nanoparticles (NP) that target lesional macrophages as a potential treatment for atherosclerosis. Ca²⁺/calmodulin-dependent protein kinase γ (CaMKIIγ) activity in macrophages of advanced human and mouse atherosclerotic plaques drives necrosis by downregulating the expression of the efferocytosis receptor MerTK. Therefore, selective inhibition of CaMKIIγ in lesional macrophages holds great promise for the treatment of advanced atherosclerosis. We recently developed a siRNA NP platform that can selectively silence CaMKIIγ in macrophages, resulting in increased plaque stability. We provide a detailed protocol for the synthesis of NP components, the preparation and characterization (physicochemical and in vitro) of siRNA NPs, and the evaluation of in vivo therapeutic effects of siRNA NPs and their biocompatibility in atherosclerotic mice. Our siRNA-loaded polymer-lipid hybrid NPs are constructed via a robust self-assembly method, exhibiting excellent in vivo features for systemic siRNA delivery. Following this protocol, it takes 3-5 d to prepare the siRNA NPs, 8-10 d to characterize the NPs and 4-5 weeks to evaluate their therapeutic effects in established atherosclerotic mice. By changing the RNA molecules loaded in the NPs, lesional macrophages can be targeted for the exploration and validation of new targets/pathways in atherosclerosis.

Mechanistic Studies of an Automated Lipid Nanoparticle Reveal Critical Pharmaceutical Properties Associated with Enhanced mRNA Functional Delivery In Vitro and In Vivo

Recently, lipid nanoparticles (LNPs) have attracted attention due to their emergent use for COVID-19 mRNA vaccines. The success of LNPs can be attributed to ionizable lipids, which enable functional intracellular delivery. Previously, the authors established an automated high-throughput platform to screen ionizable lipids and identified that the LNPs generated using this automated technique show comparable or increased mRNA functional delivery in vitro as compared to LNPs prepared using traditional microfluidics techniques. In this study, the authors choose one benchmark lipid, DLin-MC3-DMA (MC3), and investigate whether the automated formulation technique can enhance mRNA functional delivery in vivo. Interestingly, a 4.5-fold improvement in mRNA functional delivery in vivo by automated LNPs as compared to LNPs formulated by conventional microfluidics techniques, is observed. Mechanistic studies reveal that particles with large size accommodate more mRNA per LNP, possess more hydrophobic surface, are more hemolytic, bind a larger protein corona, and tend to accumulate more in macropinocytosomes, which may quantitatively benefit mRNA cytosolic delivery. These data suggest that mRNA loading per particle is a critical factor that accounts for the enhanced mRNA functional delivery of automated LNPs. These mechanistic findings provide valuable insight underlying the enhanced mRNA functional delivery to accelerate future mRNA LNP product development.

Intravesical delivery of KDM6A-mRNA via mucoadhesive nanoparticles inhibits the metastasis of bladder cancer

This study provides proof-of-principle evidence for intravesical delivery of messenger RNA (mRNA) via a mucoadhesive nanoparticle (NP) strategy and reveals the therapeutic potential of KDM6A in treating bladder cancer metastasis, which remains difficult due to the physiological bladder barriers. The mucoadhesive NPs could protect loaded mRNA, prolong exposure of mRNA in disease sites, and benefit the penetration and effective expression, which all represent challenging hurdles for intravesical delivery of mRNA therapeutics. mRNA local delivery can also avoid potential toxicity issues via systemic delivery and unwanted protein expression throughout the body. We expect this mucoadhesive mRNA nanotechnology can be useful for the effective up-regulation of targeted proteins in bladder tissues in situ for both mechanistic understanding and translational study of bladder-related diseases.

Lysine-specific demethylase 6A (KDM6A), also named UTX, is frequently mutated in bladder cancer (BCa). Although known as a tumor suppressor, KDM6A’s therapeutic potential in the metastasis of BCa remains elusive. It also remains difficult to fulfill the effective up-regulation of KDM6A levels in bladder tumor tissues in situ to verify its potential in treating BCa metastasis. Here, we report a mucoadhesive messenger RNA (mRNA) nanoparticle (NP) strategy for the intravesical delivery of KDM6A-mRNA in mice bearing orthotopic Kdm6a-null BCa and show evidence of KDM6A’s therapeutic potential in inhibiting the metastasis of BCa. Through this mucoadhesive mRNA NP strategy, the exposure of KDM6A-mRNA to the in situ BCa tumors can be greatly prolonged for effective expression, and the penetration can be also enhanced by adhering to the bladder for sustained delivery. This mRNA NP strategy is also demonstrated to be effective for combination cancer therapy with other clinically approved drugs (e.g., elemene), which could further enhance therapeutic outcomes. Our findings not only report intravesical delivery of mRNA via a mucoadhesive mRNA NP strategy but also provide the proof-of-concept for the usefulness of these mRNA NPs as tools in both mechanistic understanding and translational study of bladder-related diseases.

Combining p53 mRNA nanotherapy with immune checkpoint blockade reprograms the immune microenvironment for effective cancer therapy

Immunotherapy with immune checkpoint blockade (ICB) has shown limited benefits in hepatocellular carcinoma (HCC) and other cancers, mediated in part by the immunosuppressive tumor microenvironment (TME). As p53 loss of function may play a role in immunosuppression, we herein examine the effects of restoring p53 expression on the immune TME and ICB efficacy. We develop and optimize a CXCR4-targeted mRNA nanoparticle platform to effectively induce p53 expression in HCC models. Using p53-null orthotopic and ectopic models of murine HCC, we find that combining CXCR4-targeted p53 mRNA nanoparticles with anti-PD-1 therapy effectively induces global reprogramming of cellular and molecular components of the immune TME. This effect results in improved anti-tumor effects compared to anti-PD-1 therapy or therapeutic p53 expression alone. Thus, our findings demonstrate the reversal of immunosuppression in HCC by a p53 mRNA nanomedicine when combined with ICB and support the implementation of this strategy for cancer treatment.

The p53 tumor suppressor gene is frequently mutated in liver cancer. Here the authors show that restoration of p53 expression with a mRNA nanoparticle platform elicits anti-tumor immune responses and promotes response to immune checkpoint blockade in preclinical models of p53-null hepatocellular carcinoma.

Macrophage-targeting gene silencing orchestrates myocardial microenvironment remodeling toward the anti-inflammatory treatment of ischemia-reperfusion (IR) injury

Ischemia-reperfusion (IR) injury represents a major cause of myocardial dysfunction after infarction and thrombolytic therapy, and it is closely related to the free radical explosion and overwhelming inflammatory responses. Herein, macrophage-targeting nanocomplexes (NCs) are developed to mediate efficient co-delivery of siRNA against MOF (siMOF) and microRNA-21 (miR21) into myocardial macrophages, cooperatively orchestrating the myocardial microenvironment against IR injury. Bioreducible, branched poly(β-amino ester) (BPAE-SS) is designed to co-condense siMOF and miR21 into NCs in a multivalency-reinforced approach, and they are surface-decorated with carboxylated mannan (Man-COOH) to shield the positive surface charges and enhance the serum stability. The final MBSsm NCs are efficiently internalized by myocardial macrophages after systemic administration, wherein BPAE-SS is degraded into small segments by intracellular glutathione to promote the siMOF/miR21 release, finally provoking efficient gene silencing. Thus, cardiomyocyte protection and macrophage modulation are realized via the combined effects of ROS scavenging, inflammation inhibition, and autophagy attenuation, which ameliorates the myocardial microenvironment and restores the cardiac function via positive cellular crosstalk. This study renders promising solutions to address the multiple systemic barriers against in vivo nucleic acid delivery, and it also offers new options for IR injury by manipulating multiple reciprocal bio-reactions.

•

Macrophage-targeting and reduction-dissociable NCs mediate efficient siMOF/miR21 co-delivery.

•

siMOF and miR21 cooperatively inhibit ROS production, inflammation, and autophagy.

•

siMOF and miR21 orchestrate microenvironment remodeling via cellular cross-talk.

•

NCs mediate efficient treatment of myocardial ischemia reperfusion injury.