PGMA-Based Star-Like Polycations with Plentiful Hydroxyl Groups Act as Highly Efficient miRNA Delivery Nanovectors for Effective Applications in Heart Diseases

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.

Delivery of miRNAs Using Nanoparticles for the Treatment of Osteosarcoma

Osteosarcoma is the predominant primary malignant bone tumor that poses a significant global health challenge. MicroRNAs (miRNAs) that regulate gene expression are associated with osteosarcoma pathogenesis. Thus, miRNAs are potential therapeutic targets for osteosarcoma. Nanoparticles, widely used for targeted drug delivery, facilitate miRNA-based osteosarcoma treatment. Numerous studies have focused on miRNA delivery using nanoparticles to inhibit the progress of osteosarcoma. Polymer-based, lipid-based, inorganic-based nanoparticles and extracellular vesicles were used to deliver miRNAs for the treatment of osteosarcoma. They can be modified to enhance drug loading and delivery capabilities. Also, miRNA delivery was combined with traditional therapies, for example chemotherapy, to treat osteosarcoma. Consequently, miRNA delivery offers promising therapeutic avenues for osteosarcoma, providing renewed hope for patients. This review emphasizes the studies utilizing nanoparticles for miRNA delivery in osteosarcoma treatment, then introduced and summarized the nanoparticles in detail. And it also discusses the prospects for clinical applications.

Recent Review on Biological Barriers and Host-Material Interfaces in Precision Drug Delivery: Advancement in Biomaterial Engineering for Better Treatment Therapies

Preclinical and clinical studies have demonstrated that precision therapy has a broad variety of treatment applications, making it an interesting research topic with exciting potential in numerous sectors. However, major obstacles, such as inefficient and unsafe delivery systems and severe side effects, have impeded the widespread use of precision medicine. The purpose of drug delivery systems (DDSs) is to regulate the time and place of drug release and action. They aid in enhancing the equilibrium between medicinal efficacy on target and hazardous side effects off target. One promising approach is biomaterial-assisted biotherapy, which takes advantage of biomaterials' special capabilities, such as high biocompatibility and bioactive characteristics. When administered via different routes, drug molecules deal with biological barriers; DDSs help them overcome these hurdles. With their adaptable features and ample packing capacity, biomaterial-based delivery systems allow for the targeted, localised, and prolonged release of medications. Additionally, they are being investigated more and more for the purpose of controlling the interface between the host tissue and implanted biomedical materials. This review discusses innovative nanoparticle designs for precision and non-personalised applications to improve precision therapies. We prioritised nanoparticle design trends that address heterogeneous delivery barriers, because we believe intelligent nanoparticle design can improve patient outcomes by enabling precision designs and improving general delivery efficacy. We additionally reviewed the most recent literature on biomaterials used in biotherapy and vaccine development, covering drug delivery, stem cell therapy, gene therapy, and other similar fields; we have also addressed the difficulties and future potential of biomaterial-assisted biotherapies.

'Passive' nanoparticles for organ-selective systemic delivery: design, mechanism and perspective

Nanotechnology has shown tremendous success in the drug delivery field for more effective and safer therapy, and has recently enabled the clinical approval of RNA medicine, a new class of therapeutics. Various nanoparticle strategies have been developed to improve the systemic delivery of therapeutics, among which surface modification of targeting ligands on nanoparticles has been widely explored for 'active' delivery to a specific organ or diseased tissue. Meanwhile, compelling evidence has recently been reported that organ-selective targeting may also be achievable by systemic administration of nanoparticles without surface ligand modification. In this Review, we highlight this unique set of 'passive' nanoparticles and their compositions and mechanisms for organ-selective delivery. In particular, the lipid-based, polymer-based, and biomimetic nanoparticles with tropism to different specific organs after intravenous administration are summarized. The underlying mechanisms (e.g., protein corona and size effect) of these nanosystems for organ selectivity are also extensively discussed. We further provide perspectives on the opportunities and challenges in this exciting area of organ-selective systemic nanoparticle delivery.

Biomaterial-assisted biotherapy: A brief review of biomaterials used in drug delivery, vaccine development, gene therapy, and stem cell therapy

Biotherapy has recently become a hotspot research topic with encouraging prospects in various fields due to a wide range of treatments applications, as demonstrated in preclinical and clinical studies. However, the broad applications of biotherapy have been limited by critical challenges, including the lack of safe and efficient delivery systems and serious side effects. Due to the unique potentials of biomaterials, such as good biocompatibility and bioactive properties, biomaterial-assisted biotherapy has been demonstrated to be an attractive strategy. The biomaterial-based delivery systems possess sufficient packaging capacity and versatile functions, enabling a sustained and localized release of drugs at the target sites. Furthermore, the biomaterials can provide a niche with specific extracellular conditions for the proliferation, differentiation, attachment, and migration of stem cells, leading to tissue regeneration. In this review, the state-of-the-art studies on the applications of biomaterials in biotherapy, including drug delivery, vaccine development, gene therapy, and stem cell therapy, have been summarized. The challenges and an outlook of biomaterial-assisted biotherapies have also been discussed.

Non-coding RNAs: Important participants in cardiac fibrosis

Cardiac remodeling is a pathophysiological process activated by diverse cardiac stress, which impairs cardiac function and leads to adverse clinical outcome. This remodeling partly attributes to cardiac fibrosis, which is a result of differentiation of cardiac fibroblasts to myofibroblasts and the production of excessive extracellular matrix within the myocardium. Non-coding RNAs mainly include microRNAs and long non-coding RNAs. These non-coding RNAs have been proved to have a profound impact on biological behaviors of various cardiac cell types and play a pivotal role in the development of cardiac fibrosis. This review aims to summarize the role of microRNAs and long non-coding RNAs in cardiac fibrosis associated with pressure overload, ischemia, diabetes mellitus, aging, atrial fibrillation and heart transplantation, meanwhile shed light on the diagnostic and therapeutic potential of non-coding RNAs for cardiac fibrosis.

The protein corona modulates the inflammation inhibition by cationic nanoparticles via cell-free DNA scavenging

A central paradigm in nanomedicine is that when synthetic nanoparticles (NPs) enter the body, they are immediately cloaked by a corona of macromolecules (mostly proteins) that mediates the role of the physico-chemical properties in the NP biological functions (the “coronation paradigm”). In this work, we focused on the assessment of the “coronation paradigm” for cationic NPs (cNPs) used as rheumatoid arthritis (RA) drugs due to their ability to scavenge cell-free DNA (cfDNA). We fabricated series of cNPs uniformly coated with single or di-hydroxyl groups and different types of amino groups and showed that hydroxylated nanoparticles displayed a prolonged retention in inflamed joints and greater anti-inflammatory effect in collagen-induced arthritis (CIA) rats than the non-hydroxylated analogues. Especially, the cNPs with secondary amines and a di-hydroxyl shell showed the best performance among the tested cNPs. Proteomic analysis showed that the cNPs with a di-hydroxyl shell adsorbed less opsonin proteins than the cNPs carrying mono hydroxyl groups and non-hydroxylated ones, which may provide a mechanistic explanation for the different biodistribution profiles of cNPs. Thus, this study suggests that the protein corona mediates the effects of the surface chemistry on the fate and functions of cNPs as anti-RA drugs.

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cNPs with hydroxyl shell decreased side-effects to cells and CIA rats without decreasing the ability to scavenge cfDNA.

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Hydroxyl shell reduced the adsorption of proteins, thus prolonged the circulation and site accumulation of cNPs.

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The composition of the protein corona formed onto the cNPs in the serum can be modulated by their synthetic identity.

Prevent Drug Leakage via the Boronic Acid Glucose-Insensitive Micelle for Alzheimer's Disease Combination Treatment

Boronic acid (BA) materials have been widely applied to glucose and oxidative stress-sensitive drug delivery for the treatment of cancer, diabetes, and Alzheimer's disease (AD). There are completely various BA-sensitive delivery conditions in different diseases. BA materials in the treatment of diabetes show better performance at a high-glucose environment than normal. In contrast, the concentration of glucose in the brain is much lower than that in the blood of AD patients. Hence, the typical glucose and oxidative stress dual-sensitive BA materials inevitably encounter drug leakage in circulation in AD. Attempts to decrease the glucose-sensitive capacity of BA materials are extremely essential for AD drug delivery. In this study, the epoxy group (electron-donating group) was introduced to increase the pKa values of BA materials by increasing the electron cloud density, and thus, the glucose-insensitive micelle (GIM) was obtained. The treatment effect and the synergism mechanism of the drug-loaded GIM micelle were studied on senescence-accelerated mouse prone 8 mice. This work provided excellent antioxidant drugs (vitamin E succinate, melatonin, and quercetin) and a glucose metabolism drug (insulin) loaded in GIM micelle for AD treatment. The discovery of the combination mechanism is enormously valuable for AD clinical research.

Gene Therapy for Cardiovascular Disease: Basic Research and Clinical Prospects

In recent years, the vital role of genetic factors in human diseases have been widely recognized by scholars with the deepening of life science research, accompanied by the rapid development of gene-editing technology. In early years, scientists used homologous recombination technology to establish gene knock-out and gene knock-in animal models, and then appeared the second-generation gene-editing technology zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) that relied on nucleic acid binding proteins and endonucleases and the third-generation gene-editing technology that functioned through protein-nucleic acids complexes-CRISPR/Cas9 system. This holds another promise for refractory diseases and genetic diseases. Cardiovascular disease (CVD) has always been the focus of clinical and basic research because of its high incidence and high disability rate, which seriously affects the long-term survival and quality of life of patients. Because some inherited cardiovascular diseases do not respond well to drug and surgical treatment, researchers are trying to use rapidly developing genetic techniques to develop initial attempts. However, significant obstacles to clinical application of gene therapy still exists, such as insufficient understanding of the nature of cardiovascular disease, limitations of genetic technology, or ethical concerns. This review mainly introduces the types and mechanisms of gene-editing techniques, ethical concerns of gene therapy, the application of gene therapy in atherosclerosis and inheritable cardiovascular diseases, in-stent restenosis, and delivering systems.

Lipids and Lipid Derivatives for RNA Delivery

RNA-based therapeutics have shown great promise in treating a broad spectrum of diseases through various mechanisms including knockdown of pathological genes, expression of therapeutic proteins, and programmed gene editing. Due to the inherent instability and negative-charges of RNA molecules, RNA-based therapeutics can make the most use of delivery systems to overcome biological barriers and to release the RNA payload into the cytosol. Among different types of delivery systems, lipid-based RNA delivery systems, particularly lipid nanoparticles (LNPs), have been extensively studied due to their unique properties, such as simple chemical synthesis of lipid components, scalable manufacturing processes of LNPs, and wide packaging capability. LNPs represent the most widely used delivery systems for RNA-based therapeutics, as evidenced by the clinical approvals of three LNP-RNA formulations, patisiran, BNT162b2, and mRNA-1273. This review covers recent advances of lipids, lipid derivatives, and lipid-derived macromolecules used in RNA delivery over the past several decades. We focus mainly on their chemical structures, synthetic routes, characterization, formulation methods, and structure-activity relationships. We also briefly describe the current status of representative preclinical studies and clinical trials and highlight future opportunities and challenges.

Non-Viral Gene Delivery Systems for Treatment of Myocardial Infarction: Targeting Strategies and Cardiac Cell Modulation

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality worldwide. Conventional therapies involving surgery or pharmacological strategies have shown limited therapeutic effects due to a lack of cardiac tissue repair. Gene therapy has opened an avenue for the treatment of cardiac diseases through manipulating the underlying gene mechanics. Several gene therapies for cardiac diseases have been assessed in clinical trials, while the clinical translation greatly depends on the delivery technologies. Non-viral vectors are attracting much attention due to their safety and facile production compared to viral vectors. In this review, we discuss the recent progress of non-viral gene therapies for the treatment of cardiovascular diseases, with a particular focus on myocardial infarction (MI). Through a summary of delivery strategies with which to target cardiac tissue and different cardiac cells for MI treatment, this review aims to inspire new insights into the design/exploitation of non-viral delivery systems for gene cargos to promote cardiac repair/regeneration.

Hydrogel-mediated delivery of microRNA-92a inhibitor polyplex nanoparticles induces localized angiogenesis

Localized stimulation of angiogenesis is an attractive strategy to improve the repair of ischemic or injured tissues. Several microRNAs (miRNAs) such as miRNA-92a (miR-92a) have been reported to negatively regulate angiogenesis in ischemic disease. To exploit the clinical potential of miR-92a inhibitors, safe and efficient delivery needs to be established. Here, we used deoxycholic acid-modified polyethylenimine polymeric conjugates (PEI-DA) to deliver a locked nucleic acid (LNA)-based miR-92a inhibitor (LNA-92a) in vitro and in vivo. The positively charged PEI-DA conjugates condense the negatively charged inhibitors into nano-sized polyplexes (135 ± 7.2 nm) with a positive net charge (34.2 ± 10.6 mV). Similar to the 25 kDa-branched PEI (bPEI25) and Lipofectamine RNAiMAX, human umbilical vein endothelial cells (HUVECs) significantly internalized PEI-DA/LNA-92a polyplexes without any obvious cytotoxicity. Down-regulation of miR-92a following the polyplex-mediated delivery of LNA-92a led to a substantial increase in the integrin subunit alpha 5 (ITGA5), the sirtuin-1 (SIRT1) and Krüppel-like factors (KLF) KLF2/4 expression, formation of capillary-like structures by HUVECs, and migration rate of HUVECs in vitro. Furthermore, PEI-DA/LNA-92a resulted in significantly enhanced capillary density in a chicken chorioallantoic membrane (CAM) model. Localized angiogenesis was substantially induced in the subcutaneous tissues of mice by sustained release of PEI-DA/LNA-92a polyplexes from an in situ forming, biodegradable hydrogel based on clickable poly(ethylene glycol) (PEG) macromers. Our results indicate that PEI-DA conjugates efficiently deliver LNA-92a to improve angiogenesis. Localized delivery of RNA interference (RNAi)-based therapeutics via hydrogel-laden PEI-DA polyplex nanoparticles appears to be a safe and effective approach for different therapeutic targets.

Fabrication of aminated poly(glycidyl methacrylate)-based polymers for co-delivery of anticancer drugs and the p53 gene

Aminated poly(glycidyl methacrylate)s-based polymers for gene delivery not only can reduce toxicity and improve solubility, but can improve gene transfection efficiency and reduce protein aggregation. In this study, we first prepared poly(glycidyl methacrylate) (PGMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization, and then the obtained PGMA homopolymer was post-modified with ethanol amine (EA), 1-amino-2-propanol (AP), 3-(dibutylamino)propylamine (DA) and N-(2-hydroxyethyl)ethylenediamine (HA), respectively, to yield four kinds of PGMA-based gene vectors containing hydroxyl groups (abbreviated as PGEA, PGAP, PGDA and PGHA). The effects of the different side chains and hydroxyl groups on the biological properties of these four cationic polymers were investigated. We found that the transfection efficiency of the PGHA/p53 complex was higher than those of the other three polymer/gene complexes through MTT assay and laser scanning confocal microscopy. Hence, we chose HA for further post-modification to fabricate a cationic copolymer, PCL-ss-P(PEGMA-co-GHA) (abbreviated as PGHAP), via a combination of ring opening polymerization (ROP) and RAFT copolymerization. The PCL-ss-P(PEGMA-co-GHA) amphiphilic copolymer could self-assemble into nanoparticles, which could be used to encapsulate anticancer drug doxorubicin (DOX) and compress the p53 gene to form the DOX-loaded PCL-ss-P(PEGMA-co-GHA)/p53 complex (abbreviated as DPGHAP/p53). The gel retardation assay showed that p53 gene could be well immobilized and remained stable under the electronegative conditions. MTT assay showed that the DPGHAP/p53 complex had a significant antitumor effect on A549 cells and H1299 cells compared with free DOX or/and p53 gene therapy alone. Furthermore, the test results from live cell imaging systems revealed that the DPGHAP/p53 complexes could effectively deliver DOX and the p53 gene into A549 cells. Therefore, the constructed cationic polymer PCL-ss-P(PEGMA-co-GHA) has potential application prospects as a co-vector of anticancer drugs and genes.

Reversible Treatment of Pressure Overload-Induced Left Ventricular Hypertrophy through Drd5 Nucleic Acid Delivery Mediated by Functional Polyaminoglycoside

Left ventricular hypertrophy and fibrosis are major risk factors for heart failure, which require timely and effective treatment. Genetic therapy has been shown to ameliorate hypertrophic cardiac damage. In this study, it is found that in mice, the dopamine D5 receptor (D5R) expression in the left ventricle (LV) progressively decreases with worsening of transverse aortic constriction-induced left ventricular hypertrophy. Then, a reversible treatment of left ventricular hypertrophy with Drd5 nucleic acids delivered by tobramycin-based hyperbranched polyaminoglycoside (SS-HPT) is studied. The heart-specific increase in D5R expression by SS-HPT/Drd5 plasmid in the early stage of left ventricular hypertrophy attenuates cardiac hypertrophy and fibrosis by preventing oxidative and endoplasmic reticulum (ER) stress and ameliorating autophagic dysregulation. By contrast, SS-HPT/Drd5 siRNA promotes the progression of left ventricular hypertrophy and accelerates the deterioration of myocardial function into heart failure. The reduction in cardiac D5R expression and dysregulated autophagy are observed in patients with hypertrophic cardiomyopathy and heart failure. The data show a cardiac-specific beneficial effect of SS-HPT/Drd5 plasmid on myocardial remodeling and dysfunction, which may provide an effective therapy of patients with left ventricular hypertrophy and heart failure.

Oncogenic Epidermal Growth Factor Receptor Silencing in Cervical Carcinoma Mediated by Dynamic Sugar-Benzoxaborole Polyplexes

Although, various types of pharmaceuticals have been developed for cervical carcinomas, treatment with these drugs often results in a number of undesirable side effects, toxicity and multidrug resistance. Here, we aimed at modifying the genetic profiling of cancer cells by silencing the expression of the epidermal growth factor receptor (EGFR) gene. We have synthesized two kinds of RAFT-made, biocompatible, and cationic polymers for the encapsulation of silencing RNA (siRNA). This vector has a dual capability: it contains a cationic segment to complex with the siRNA and an omega-end modified with an oxaborole group via thiol-ene click chemistry that responds to the acidic tumor microenvironment. This structural innovation enables this macromolecule to interact with multiple polyplexes and release the siRNA in a mild acidic environment. A strategy that has shown enhanced gene silencing without elevating the cytotoxicity of the system, as determined by Western blot analysis. The success of this approach has afforded further interest in utilizing boron-carbohydrate interaction in the development of nonviral vectors for gene therapy.

Surface Engineering of Cardiovascular Devices for Improved Hemocompatibility and Rapid Endothelialization

Cardiovascular devices have been widely applied in the clinical treatment of cardiovascular diseases. However, poor hemocompatibility and slow endothelialization on their surface still exist. Numerous surface engineering strategies have mainly sought to modify the device surface through physical, chemical, and biological approaches to improve surface hemocompatibility and endothelialization. The alteration of physical characteristics and pattern topographies brings some hopeful outcomes and plays a notable role in this respect. The chemical and biological approaches can provide potential signs of success in the endothelialization of vascular device surfaces. They usually involve therapeutic drugs, specific peptides, adhesive proteins, antibodies, growth factors and nitric oxide (NO) donors. The gene engineering can enhance the proliferation, growth, and migration of vascular cells, thus boosting the endothelialization. In this review, the surface engineering strategies are highlighted and summarized to improve hemocompatibility and rapid endothelialization on the cardiovascular devices. The potential outlook is also briefly discussed to help guide endothelialization strategies and inspire further innovations. It is hoped that this review can assist with the surface engineering of cardiovascular devices and promote future advancements in this emerging research field.

Topology-assisted, photo-strengthened DNA/siRNA delivery mediated by branched poly(β-amino ester)s via synchronized intracellular kinetics

Photo-degradable, branched poly(β-amino ester)s (BPAE-NB) were developed to mediate topology-assisted trans-membrane gene delivery as well as photo-strengthened intracellular gene release.

Reduction-Responsive Nucleic Acid Delivery Systems To Prevent In-Stent Restenosis in Rabbits

Cardiovascular and cerebrovascular ischemic diseases seriously affect human health. Endovascular stent placement is an effective treatment but always leads to in-stent restenosis (ISR). Gene-eluting stent, which combines gene therapy with stent implantation, is a potential method to prevent ISR. In this study, an efficient gene-eluting stent was designed on the basis of one new nucleic acid delivery system to decrease the possibility of ISR. The reduction-responsive branched nucleic acid vector (SKP) with low cytotoxicity was first synthesized via ring-opening reaction. The impressive in vitro transfection performances of SKP were proved using luciferase reporter, enhanced green fluorescent protein plasmid, and vascular endothelial growth factor plasmid (pVEGF). Subsequently, SKP/pVEGF complexes were coated on the surfaces of pretreated clinical stents to construct gene-eluting stents (S-SKP/pVEGF). Antirestenosis performance of S-SKP/pVEGF was evaluated via implanting stents into rabbit aortas. S-SKP/pVEGF could lead to the localized upregulation of VEGF proteins, improve the progress of re-endothelialization, and inhibit the development of ISR in vivo. Such efficient pVEGF-eluting stent with responsive nucleic acid delivery systems is very promising to prevent in-stent restenosis of cerebrovascular diseases.

Multifunctional cationic nanosystems for nucleic acid therapy of thoracic aortic dissection

Thoracic aortic dissection (TAD) is an aggressive vascular disease that requires early diagnosis and effective treatment. However, due to the particular vascular structure and narrowness of lesion location, there are no effective drug delivery systems for the therapy of TAD. Here, we report a multifunctional delivery nanosystem (TP-Gd/miRNA-ColIV) composed of gadolinium-chelated tannic acid (TA), low-toxic cationic PGEA (ethanolamine-aminated poly(glycidyl methacrylate)) and type IV collagen targeted peptide (ColIV) for targeted nucleic acid therapy, early diagnosis and noninvasive monitoring of TAD. Such targeted therapy with miR-145 exhibits impressive performances in stabilizing the vascular structures and preventing the deterioration of TAD. After the treatment with TP-Gd/miR-145-ColIV, nearly no dissection occurs in the thoracic aortic arches of the mice with TAD model. Moreover, TP-Gd/miRNA-ColIV also demonstrates good magnetic resonance imaging (MRI) ability and can be used to noninvasively monitor the development conditions of TAD.

CRISPR/Cas9 Delivery Mediated with Hydroxyl-Rich Nanosystems for Gene Editing in Aorta

A CRISPR/Cas9 system has emerged as a powerful tool for gene editing to treat genetic mutation related diseases. Due to the complete endothelial barrier, effective delivery of the CRISPR/Cas9 system to vasculatures remains a challenge for in vivo gene editing of genetic vascular diseases especially in aorta. Herein, it is reported that CHO-PGEA (cholesterol (CHO)-terminated ethanolamine-aminated poly(glycidyl methacrylate)) with rich hydroxyl groups can deliver a plasmid based pCas9-sgFbn1 system for the knockout of exon 10 in Fbn1 gene. This is the first report of a polycation-mediated CRISPR/Cas9 system for gene editing in aorta of adult mice. CHO-PGEA/pCas9-sgFbn1 nanosystems can effectively contribute to the knockout of exon 10 in Fbn1 in vascular smooth muscle cells in vitro, which leads to the change of the phosphorylation of Smad2/3 and the increased expression of two downstream signals of Fbn1: Mmp-2 and Ctgf. For in vivo application, the aortic enrichment of CHO-PGEA/Cas9-sgFbn1 is achieved by administering a pressor dose of angiotensin II (Ang II). The effects of the pCas9-sgFbn1 system targeting Fbn1 demonstrate an increase in the expression of Mmp-2 and Ctgf in aorta. Thus, the combination of CHO-PGEA/pCas9-sgFbn1 nanosystems with Ang II infusion can provide the possibility for in vivo gene editing in aorta.

Effective Delivery of Hypertrophic miRNA Inhibitor by Cholesterol-Containing Nanocarriers for Preventing Pressure Overload Induced Cardiac Hypertrophy

Persistent cardiac hypertrophy causes heart failure and sudden death. Gene therapy is a promising intervention for this disease, but is limited by the lack of effective delivery systems. Herein, it is reported that CHO-PGEA (cholesterol (CHO)-terminated ethanolamine-aminated poly(glycidyl methacrylate)) can efficiently condense small RNAs into nanosystems for preventing cardiac hypertrophy. CHO-PGEA contains two features: 1) lipophilic cholesterol groups enhance transfection efficiency in cardiomyocytes, 2) abundant hydrophilic hydroxyl groups benefit biocompatibility. miR-182, which is known to downregulate forkhead box O3, is selected as an intervention target and can be blocked by synthetic small RNA inhibitor of miR-182 (miR-182-in). CHO-PGEA can efficiently deliver miR-182-in into hearts. In the mice with aortic coarctation, CHO-PEGA/miR-182-in significantly suppresses cardiac hypertrophy without organ injury. This work demonstrates that CHO-PGEA/miRNA nanosystems are very promising for RNA-based therapeutics to treat heart diseases.

Core-Shell Polymer-Based Nanoparticles Deliver miR-155-5p to Endothelial Cells

Heart failure occurs in over 30% of the worldwide population and most commonly originates from cardiovascular diseases such as myocardial infarction. microRNAs (miRNAs) target and silence specific mRNAs, thereby regulating gene expression. Because the endogenous miR-155-5p has been ascribed to vasculoprotection, loading it onto positively charged, core-shell poly(isobutylcyanoacrylate) (PIBCA)-polysaccharide nanoparticles (NPs) was attempted. NPs showed a decrease (p < 0.0001) in surface electrical charge (ζ potential), with negligible changes in size or shape when loaded with the anionic miR-155-5p. Presence of miR-155-5p in loaded NPs was further quantified. Cytocompatibility up to 100 μg/mL of NPs for 2 days with human coronary artery endothelial cells (hCAECs) was documented. NPs were able to enter hCAECs and were localized in the endoplasmic reticulum (ER). Expression of miR-155-5p was increased within the cells by 75-fold after 4 hours of incubation (p < 0.05) and was still noticeable at day 2. Differences between loaded NP-cultured cells and free miRNA, at days 1 (p < 0.05) and 2 (p < 0.001) suggest the ability of prolonged load release in physiological conditions. Expression of miR-155-5p downstream target BACH1 was decreased in the cells by 4-fold after 1 day of incubation (p < 0.05). This study is a first proof of concept that miR-155-5p can be loaded onto NPs and remain intact and biologically active in endothelial cells (ECs). These nanosystems could potentially increase an endogenous cytoprotective response and decrease damage within infarcted hearts.

Hydroxyl-Rich PGMA-Based Cationic Glycopolymers for Intracellular siRNA Delivery: Biocompatibility and Effect of Sugar Decoration Degree

The ErbB family of proteins, structurally related to the epidermal growth factor receptor (EGFR), is found to be overexpressed in many cancers such as gliomas, a lung and cervical carcinomas. Gene therapy allows to modify the expression of genes like ErbB and has been a promising strategy to target oncogenes and tumor suppressor genes. In the current work, novel hydroxyl-rich poly(glycidyl methacrylate) (PGMA)-based cationic glycopolymers were designed for intracellular small interfering RNA (siRNA) delivery to silence the EGFR gene. The cationic polymers with different sugar decoration degrees (0, 9, and 33%) were synthesized by ring-opening reaction of PGMA with ethanolamine and a lactobionic acid-derived aminosaccharide (Lac-NH₂). Specific EGFR knockdown of the protein tyrosine kinase ErbB-overexpressing HeLa cells was achieved using these hydroxyl-rich polycation/siRNA complexes. Higher sugar content improved the biocompatibility of the polymers, but it also seems to decrease the EGFR knockdown capability, which should mainly be related to the surface charge of polyplexes. An optimum balance was observed with PGEL-1 (9% sugar content) formulation, achieving ∼52% knockdown efficiency as well as high cell viability. Considering the specific recognition between galactose residues and asialoglycoprotein receptor in hepatocytes, our novel PGMA-based cationic glycopolymers exhibited promising future to serve as a safe and targeting gene delivery vector to hepatoma cell line like HepG2.

Organic/inorganic nanohybrids as multifunctional gene delivery systems

In this review, we summarize the rational design and versatile application of organic/inorganic hybrid gene carriers as multifunctional delivery systems. Organic/inorganic nanohybrids with both organic and inorganic components in one nanoparticle have attracted intense attention because of their favorable properties. Particularly, nanohybrids comprising cationic polymers and inorganic nanoparticles are considered to be promising candidates as multifunctional gene delivery systems. In this review, we begin with an introduction of gene delivery and gene carriers to demonstrate the incentive for fabricating nanohybrids as multifunctional carriers. Next, the construction strategies and morphology effects of organic/inorganic hybrid gene carriers are summarized and discussed. Both sections provide valuable information for the design and synthesis of hybrid gene carriers with superior properties. Finally, an overview is provided of the application of nanohybrids as multifunctional gene carriers. Diverse therapies and versatile imaging-guided therapies have been achieved via the rational design of nanohybrids. In addition to a simple combination of the functions of organic and inorganic components, the performances arising from the synergistic effects of both components are considered to be more intriguing. In summary, this review might offer guidance for the understanding of organic/inorganic nanohybrids as multifunctional gene delivery systems.

Polycations for Gene Delivery: Dilemmas and Solutions

Gene therapy has been a promising strategy for treating numerous gene-associated human diseases by altering specific gene expressions in pathological cells. Application of nonviral gene delivery is hindered by various dilemmas encountered in systemic gene therapy. Therefore, solutions must be established to address the unique requirements of gene-based treatment of diseases. This review will particularly highlight the dilemmas in polycation-based gene therapy by systemic treatment. Several promising strategies, which are expected to overcome these challenges, will be briefly reviewed. This review will also explore the development of polycation-based gene delivery systems for clinical applications.

Fluorinated Acid-Labile Branched Hydroxyl-Rich Nanosystems for Flexible and Robust Delivery of Plasmids

Nucleic acid-based therapy specially needs a safe and robust delivery vector. Herein, a novel fluorinated acid-labile branched hydroxyl-rich polycation (ARP-F) is proposed for the flexible and effective delivery nanovector of different plasmids including reporter genes and the Cas9 plasmid. Acid-responsive polycation (ARP) with plentiful ortho ester linkages and hydroxyl groups is first synthesized via a facile one-pot ring-opening polymerization, followed by decoration of fluorinated alkyl chains onto ARP to achieve ARP-F. ARP-F possesses good pH-responsive degradability, biocompatibility, and its preliminary transfection ability evaluated by reporter plasmids pRL-CMV (encoding Renilla luciferase) and pEGFP-N1 (encoding enhanced green fluorescent protein) is also excellent. CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat/CRISPR-associated nuclease 9) technology is a potent genome-editing tool. The subsequent delivery of pCas9-surv (one typical all-in-one Cas9 plasmid) mediated by ARP-F exhibits impressive in vitro and in vivo tumor inhibition performances. In addition, the combination of ARP-F/pCas9-surv with temozolomide could further enhance tumor inhibition activities by increasing the sensitivity of cancer cells to anticancer drugs. Such high-performance polycation would provide a very promising means to produce efficient delivery nanovectors of versatile plasmids.

Unlockable Nanocomplexes with Self-Accelerating Nucleic Acid Release for Effective Staged Gene Therapy of Cardiovascular Diseases

Nucleic acid (NA)-based therapy is proposed to address serious diseases such as cardiovascular diseases (CVDs). Powerful NA delivery vehicles are essential for effective gene therapy. Herein, a novel type of delivery vehicle, an unlockable core-shell nanocomplex (Hep@PGEA) with self-accelerating NA release, is structurally designed. Hep@PGEA is composed of disulfide-bridged heparin nanoparticle (HepNP) core and low-toxicity PGEA cationic shell. In comparison with NA, heparin, a negatively charged polysaccharide macromolecule, exhibits stronger interactions with cationic species. Upon the breakdown of redox-responsive HepNP cores, unlocked heparin would interact with the outer cationic shells and replace the condensed NA to facilitate NA release. Such unique Hep@PGEA is successfully explored for effective miRNA-pDNA staged gene therapy of myocardial infarction (MI), one of the most serious CVDs. With the progression of MI, glutathione amounts in heart tissues increase. MiR-499 (for the inhibition of cardiomyocyte apoptosis) and plasmid encoding vascular endothelial growth factor (for the promotion of angiogenesis) are sequentially delivered for systemic treatment of MI. Such treatment produces impressive results in restoring heart function and suppressing cardiac hypertrophy. Due to the wide existence of redox agents in cells, the proposed unlockable delivery nanovehicle and staged therapy strategy can provide new methods to effectively treat different serious diseases.

Rodlike Supramolecular Nanoassemblies of Degradable Poly(Aspartic Acid) Derivatives and Hydroxyl-Rich Polycations for Effective Delivery of Versatile Tumor-Suppressive ncRNAs

The delivery of tumor-suppressive noncoding RNAs (ncRNAs) including short ncRNAs (i.e., miRNAs) and long ncRNAs (lncRNAs) is put forward to treat tumors. In this work, novel rodlike supramolecular nanoassemblies (CNC @CB[8] @ PGEA) of degradable poly(aspartic acid) (PAsp) derivatives-grafted cellulose nanocrystals (CNCs) and hydroxyl-rich polycations (ethanolamine-functionalized poly(glycidyl methacrylate), PGEA) are proposed via typical cucurbit[8]uril (CB[8])-based host-guest interactions for delivery of different ncRNAs to treat hepatocellular carcinoma (HCC). Spindly CNCs, one kind of natural polysaccharide nanoparticles, possess good biocompatibility and unique physico-chemical properties. PGEA with abundant hydroxyl groups is one promising gene carrier with low cytotoxicity. PAsp can benefit the disassembly and degradability of nanoassemblies within cells. CNC @ CB[8]@PGEA combines the different unique properties of CNC, PGEA, and PAsp. CNC @ CB[8] @ PGEA effectively complexes the expression constructs of miR-101 (plasmid pc3.0-miR-101) and lncRNA MEG3 (plasmid pc3.0-MEG3). CNC @ CB[8] @ PGEA produces much better transfection performances than PGEA-containing assembly units. In addition, the codelivery system of CNC @ CB[8] @ PGEA/(pc3.0-MEG3+pc3.0-miR-101) nanocomplexes demonstrates better efficacy in suppressing HCC than CNC @ CB[8] @ PGEA/pc3.0-MEG3 or CNC @ CB[8] @ PGEA/pc3.0-miR-101 nanocomplexes alone. Such rodlike supramolecular nanoassemblies will provide a promising means to produce efficient delivery vectors of versatile tumor-suppressive nucleic acids.

Acid-sensitive poly(β-cyclodextrin)-based multifunctional supramolecular gene vector

Multifunctional host–guest supramolecular PCD-acetal-PGEA/Ad-PEG-FA polyplexes showing FA-targeting and acid-triggered intracellular gene release resulted in good transfection efficiency and low cytotoxicity.

Rod-Shaped Active Drug Particles Enable Efficient and Safe Gene Delivery

Efficient microRNAs (miRNA) delivery into cells is a promising strategy for disease therapy, but is a major challenge because the available conventional nonviral vectors have significant drawbacks. In particular, after these vectors are entrapped in lysosomes, the escape efficiency of genes from lysosomes into the cytosol is less than 2%. Here, a novel approach for lethal-7a (let-7a) replacement therapy using rod-shaped active pure drug nanoparticles (≈130 nm in length, PNPs) with a dramatically high drug-loading of ≈300% as vectors is reported. Importantly, unlike other vectors, the developed PNPs/let-7a complexes (≈178 nm, CNPs) can enter cells and bypass the lysosomal route to localize to the cytosol, achieving efficient intracellular delivery of let-7a and a 50% reduction in expression of the target protein (KRAS). Also, CNPs prolong the t1/2 of blood circulation by ≈threefold and increase tumor accumulation by ≈1.5-2-fold, resulting in significantly improved antitumor efficacies. Additionally, no damage to normal organs is observed following systemic injection of CNPs. In conclusion, rod-shaped active PNPs enable efficient and safe delivery of miRNA with synergistic treatment for disease. This nanoplatform would also offer a viable strategy for the potent delivery of proteins and peptides in vitro and in vivo.

Advances in the delivery of RNA therapeutics: from concept to clinical reality

The rapid expansion of the available genomic data continues to greatly impact biomedical science and medicine. Fulfilling the clinical potential of genetic discoveries requires the development of therapeutics that can specifically modulate the expression of disease-relevant genes. RNA-based drugs, including short interfering RNAs and antisense oligonucleotides, are particularly promising examples of this newer class of biologics. For over two decades, researchers have been trying to overcome major challenges for utilizing such RNAs in a therapeutic context, including intracellular delivery, stability, and immune response activation. This research is finally beginning to bear fruit as the first RNA drugs gain FDA approval and more advance to the final phases of clinical trials. Furthermore, the recent advent of CRISPR, an RNA-guided gene-editing technology, as well as new strides in the delivery of messenger RNA transcribed in vitro, have triggered a major expansion of the RNA-therapeutics field. In this review, we discuss the challenges for clinical translation of RNA-based therapeutics, with an emphasis on recent advances in delivery technologies, and present an overview of the applications of RNA-based drugs for modulation of gene/protein expression and genome editing that are currently being investigated both in the laboratory as well as in the clinic.

Development of switchable polymers to address the dilemma of stability and cargo release in polycationic nucleic acid carriers

Cationic polymer gene delivery vehicles that effectively resist premature serum degradation often have difficulty releasing their nucleic acid cargoes. In this work, we report a pH-sensitive polymer (SP), poly(oligo(ethylene glycol) monomethyl ether methacrylate)-co-poly(2-(dimethylamino)ethyl methacrylate)-block- poly(propargyl methacrylate-graft-propyl-(4-methoxy-benzylidene)-amine) (p(PMA-PMBA)-b-(p(OEGMA-DMAEMA)), for successful in vitro and in vivo gene transfer. In the physiological condition, the hydrophobization of p(OEGMA-DMAEMA) polycations by p(PMA-PMBA) significantly enhanced the stability of its polyplexes counterpart. In endosomes, the polymer undergoes an acid-triggered hydrophilic transition through the cleavage of benzoic imines, thus allowing the vector to quickly release nucleic acid cargo due to the loss of hydrophobic functionalization. Compared to a pH-insensitive polymer (IP), SP exhibited more significant luciferase plasmid delivery efficiency with HeLa cells in vitro and with in vivo intraventricular brain injections. Therefore, the polymer designed here is a good solution to address the dilemma of stability and cargo release in gene delivery, and may have broad potential applications in therapeutic agent delivery.

MicroRNA-mediated silence of onco-lncRNA MALAT1 in different ESCC cells via ligand-functionalized hydroxyl-rich nanovectors

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies worldwide. Long noncoding RNA (lncRNA) MALAT1 acts as an essential oncogene lncRNA (onco-lncRNA) in the development of ESCC. Down-regulation of onco-lncRNA MALAT1 mediated by microRNA-101 (miR-101) and microRNA-217 (miR-217) has been proved to effectively suppress ESCC. In this study, poly(glycidyl methacrylate)-based star-like polycations with flanking folic acid (FA) ligands and rich hydrophilic hydroxyl groups (denoted as s-PGEA-FA) were proposed as efficient nanovectors to deliver miR-101 and miR-217 for silencing onco-lncRNA MALAT1 in different ESCC cells. The inhibition of ESCC by s-PGEA-FA/miRNA nanocomplexes would be achieved via subsequently targeting onco-lncRNA MALAT1 in ESCC cells. To evaluate the ESCC tumor-suppressing efficacy mediated by s-PGEA-FA/miRNA nanocomplexes, a series of assays were carried out, including gene transfection, cell proliferation, cell migration, and cell invasion. The results revealed that s-PGEA-FA-mediated miR-101 and miR-217 delivery effectively inhibited ESCC development, indicating the s-PGEA-FA nanovector was promising for future ESCC therapy.

An amphiphilic non-viral gene vector prepared by a combination of enzymatic atom transfer radical polymerization and enzymatic ring-opening polymerization

An amphiphilic non-viral gene vector (PCL-b-PGEA) was prepared by a combination of enzymatic ring-opening polymerization and enzymatic atom transfer radical polymerization for the first time and the kinetic features and gene delivery properties were investigated.

Functional electrospun fibrous scaffolds with dextran-g-poly(l-lysine)-VAPG/microRNA-145 to specially modulate vascular SMCs

Functional electrospun membranes loaded with Dex-g-PLL-VAPG/miR-145 complexes exhibit the excellent ability to modulate SMC phenotype and proliferation locally.

A Neutralized Noncharged Polyethylenimine-Based System for Efficient Delivery of siRNA into Heart without Toxicity

Cationic polymers constitute an important class of materials in development of delivery vehicles for nucleic acid-based therapeutics. Among them, polyethylenimine (PEI) has been a classical cationic carrier intensively studied for therapeutic delivery of DNA, RNA, and short RNA molecules to treat diseases. However, the development of PEI for in vivo applications has been hampered by the inherent problems associated with the material, particularly its cytotoxicity and the instability of the nucleic acid complexation systems formed via electrostatic interactions. Here, we demonstrate a strategy to modify PEI polymers via hydrazidation to create neutralized, stable, and multifunctional system for delivering siRNA molecules. Through substitution of the primary amino groups of PEI with neutral hydrazide groups, cross-linked nanoparticles with surface decorated with a model targeting ligands were generated. The neutral cross-linked siRNA nanoparticles not only showed favorable biocompatibility and cell internalization efficiency in vitro but also allowed for significant tissue uptake and gene silencing efficiency in zebrafish heart in vivo. Our study suggests transformation of conventional branched PEI into a neutral polymer that can lead to a new category of nonviral carriers, and the resulting functional delivery systems may be further explored for development of siRNA therapeutics for treating cardiovascular disease/injury.

A Facile Strategy to Prepare Hyperbranched Hydroxyl-Rich Polycations for Effective Gene Therapy

For effective gene therapy, nonviral gene carriers with low toxicity and high transfection efficiency are of much importance. In this work, we developed a facile strategy to prepare hyperbranched hydroxyl-rich polycations (denoted by TE) by the one-pot method involving ring-opening reactions between two commonly used reagents, ethylenediamine (ED) with two amino groups and 1,3,5-triglycidyl isocyanurate (TGIC) with three epoxy groups. The hyperbranched TEs with different molecular weights were investigated on their DNA condensation ability, protein absorption property, biocompatibility, transfection efficiency, and in vivo cancer therapy and toxicity. TE exhibited low cytotoxicity and protein absorption property due to the plentiful hydroxyl groups. The optimal transfection efficiency of TE was significantly higher than that of the gold standard polycationic gene carrier branched polyethylenimine (PEI, 25 kDa). Furthermore, TE was applied for in vivo tumor inhibition by the delivery of antioncogene p53, which showed good antitumor efficiency with low adverse effects. The present work provides a new concept for the facile preparation of hyperbranched hydroxyl-rich polycationic carriers with good transfection performances.