Efficient delivery of therapeutic miRNA nanocapsules for tumor suppression

Co-encapsulation of granzyme B and perforin in nanocapsules for tumour therapy: biomimicking immune cells

Granzyme B (GrB)-based immunotherapy is of interest for cancer treatment. However, insufficient cellular uptake and a lack of targeting remain challenges to make use of GrB for solid tumour therapy. As GrB induced cell death requires the help of perforin (PFN), we designed a system (nGPM) for the co-delivery of GrB and PFN. Therefore, GrB and PFN were loaded in a porous polymeric nanocapsule rich in acetylcholine analogues and matrix metalloproteinase-2 (MMP-2) responsive peptides. The neutrally charged nGPM nanocapsules showed as long circulating time and accumulated at the tumour sites. Once in the tumour the outside shell of nanocapsules became degraded by overexpressed MMP-2 proteases, resulting in the release of GrB and PFN. We found that the PFN complex formed small pores on the surface of tumour cells which allow GrB to enter the cytoplasm of tumour cells inducing cell apoptosis and tumour suppression significantly.

Nanogels: Smart tools to enlarge the therapeutic window of gene therapy

Gene therapy can potentially treat a great number of diseases, from cancer to rare genetic disorders. Very recently, the development and emergency approval of nucleic acid-based COVID-19 vaccines confirmed its strength and versatility. However, gene therapy encounters limitations due to the lack of suitable carriers to vectorize therapeutic genetic material inside target cells. Nanogels are highly hydrated nano-size crosslinked polymeric networks that have been used in many biomedical applications, from drug delivery to tissue engineering and diagnostics. Due to their easy production, tunability, and swelling properties they have called the attention as promising vectors for gene delivery. In this review, nanogels are discussed as vectors for nucleic acid delivery aiming to enlarge gene therapy's therapeutic window. Recent works highlighting the optimization of inherent transfection efficiency and biocompatibility are reviewed here. The importance of the monomer choice, along with the internal structure, surface decoration, and responsive features are outlined for the different transfection modalities. The possible sources of toxicological endpoints in nanogels are analyzed, and the strategies to limit them are compared. Finally, perspectives are discussed to identify the remining challenges for the nanogels before their translation to the market as transfection agents.

Self-Destructive Nanoscavengers Capture and Clear Neurotoxic Soluble β-Amyloid Aggregates

Cerebral soluble β-amyloid aggregates (sAβs) accumulation is one of the most important causes in Alzheimer's disease (AD) progression. In order to mitigate the neurotoxicity induced by sAβs and achieve enhanced AD therapeutic outcomes, robust sAβs clearance become an emerging task. Herein, a self-destructive nanoscavenger (SDNS) is reported based on multifunctional peptide-polymer complexes that can capture extracellular sAβs via hydrogen-bonding interactions and deliver them into microglial lysosomes. The internalized SDNS then occurs self-destruction within lysosomes and upregulates autophagy, thereby promoting the degradation of neurotoxic sAβs. Importantly, the enhanced autophagy also significantly suppresses the secretion of inflammatory factors by microglia, which is induced by internalized sAβs. Given that cerebral persistent inflammatory environment disturbs microglia-mediated phagocytosis and degradation, it is believed that this synergistic approach has valuable potential as a therapeutic strategy for AD.

Fluoropolymer Coated DNA Nanoclews for Volumetric Visualization of Oligonucleotides Delivery and Near Infrared Light Activated Anti-Angiogenic Oncotherapy

The potential of microRNA regulation in oncotherapy is limited by the lack of delivery vehicles. Herein, it is shown that fluoropolymer coated DNA nanoclews (FNCs) provide outstanding ability to deliver oligonucleotide through circulation and realize near infrared (NIR) light activated angiogenesis suppression to abrogate tumors. Oligonucleotides are loaded in DNA nanoclews through sequence specific bindings and then a fluorinated zwitterionic polymer is coated onto the surface of nanoclews. Further incorporating quantum dots in the polymer coating endows the vectors with NIR-IIb (1500-1700 nm) fluorescence and NIR light triggered release ability. The FNC vector can deliver oligonucleotides to cancer cells systemically and realize on-demand cytosolic release of the cargo with high transfection efficiency. Taking advantage of the NIR-IIb emission, the whole delivery process of FNCs is visualized volumetrically in vivo with a NIR light sheet microscope. Loaded by FNCs, an oligonucleotide can effectively silence the target miRNA when activated with NIR light, and inhibit angiogenesis inside tumor, leading to complete ablation of cancer. These findings suggest FNCs can be used as an efficient oligonucleotide delivery platform to modulate the expression of endogenous microRNA in gene therapy of cancer.

The Sequential and Systemic Administration of BMP-2 and SDF-1α Nanocapsules for Promoting Osteoporotic Fracture Healing

OBJECTIVE

The objective of this study was to investigate the use of the nanocapsule sequential delivery of BMP-2 and SDF-1α through the peripheral circulatory system to promote the healing of osteoporotic fractures.

METHODS

Based on increased vascular permeability in the early hematoma environment around the fracture and the presence of a large number of matrix metalloproteinase MMPs in the inflammatory environment, we designed MMP-sensitive nanocapsules which were formed viain situ free-radical polymerization on the surface of grow factors with 2-(methacryloyloxy) ethyl phosphorylcholine (MPC) and the bisacryloylated VPLGVRTK peptide. The antiphagic effect and biological activity of the growth factors for the nanomicrocapsule delivery system were tested by cell experiments. The 36 SD rats with an osteoporotic fracture model were randomly divided into six groups (A, B, C, D, E, and F). In this paper, the nanocapsules loaded with BMP-2 and SDF-1 are represented as n (BMP-2) and n (SDF-1α). In the six groups, the following different combinations of growth factors were injected into the bone defect site on days 1 and 3 after bone defect surgery: in group A, n (SDF-1α) combined with n (SDF-1α); in group B, n (BMP-2) combined with n (BMP-2); in group C, n (SDF-1α) + n (BMP-2) combined with n (SDF-1α) + n (BMP-2); in group D, n (SDF-1α) combined with n (BMP-2); in group E, n (BMP-2) combined with n (SDF-1α); in group F, nanocapsules without growth factor were used as the control group. Micro-CT was used to observe the effect of n(BMP-2) and n(SDF-1α) sequential delivery inearly healing in osteoporotic fractures. Finally, in this study, we evaluated the safety of the nanocapsules delivery system by detecting ectopic osteogenesis and inflammatory responses in animals.

RESULTS

Nanocapsules have low toxicity and protect the integrity and biological activity of growth factors. The results confirmed that nanocapsules could still be effectively targeted to the fracture site on days 1, 3, and 7 after intravenous administration. Growth factors encapsulated in nanocapsules have better bone repair results than natural growth factors. In particular, groups C and D had the best bone repair results than other groups.In vivo experiments confirmed that nanocapsules did not cause significant ectopic osteogenesis and inflammation.

CONCLUSION

The results confirmed that the special vascular permeability and inflammatory factor microenvironment of the fracture site could be used to deliver two growth factors with a synergistic effect through venous circulation, which could better promote the healing process of osteoporotic fracture.

Lipid-, Inorganic-, Polymer-, and DNA-Based Nanocarriers for Delivery of the CRISPR/Cas9 system

The clustered regularly interspaced short palindromic repeat (CRISPR)/associated protein 9 (CRISPR/Cas9) system has been widely explored for the precise manipulation of target DNA and has enabled efficient genomic editing in cells. Recently, CRISPR/Cas9 has shown promising potential in biomedical applications, including disease treatment, transcriptional regulation and genome-wide screening. Despite these exciting achievements, efficient and controlled delivery of the CRISPR/Cas9 system has remained a critical obstacle to its further application. Herein, we elaborate on the three delivery forms of the CRISPR/Cas9 system, and discuss the composition, advantages and limitations of these forms. Then we provide a comprehensive overview of the carriers of the system, and focus on the nonviral nanocarriers in chemical methods that facilitate efficient and controlled delivery of the CRISPR/Cas9 system. Finally, we discuss the challenges and prospects of the delivery methods of the CRISPR/Cas9 system in depth, and propose strategies to address the intracellular and extracellular barriers to delivery in clinical applications.

An antigen self-assembled and dendritic cell-targeted nanovaccine for enhanced immunity against cancer

The rise of nanotechnology has opened new horizons for cancer immunotherapy. However, most nanovaccines fabricated with nanomaterials suffer from carrier-related concerns, including low drug loading capacity, unpredictable metabolism, and potential systemic toxicity, which bring obstacles for their clinical translation. Herein, we developed an antigen self-assembled nanovaccine, which was resulted from a simple acryloyl modification of the antigen to induce self-assembly. Furthermore, a dendritic cell targeting head mannose monomer and a mevalonate pathway inhibitor zoledronic acid (Zol) were integrated or absorbed onto the nanoparticles (denoted as MEAO-Z) to intensify the immune response. The synthesized nanovaccine with a diameter of around 70 nm showed successful lymph node transportation, high dendritic cell internalization, promoted costimulatory molecule expression, and preferable antigen cross-presentation. In virtue of the above superiorities, MEAO-Z induced remarkably higher titers of serum antibody, stronger cytotoxic T lymphocyte immune responses and IFN-γ secretion than free antigen and adjuvants. In vivo, MEAO-Z significantly suppressed EG7-OVA tumor growth and prolonged the survival time of tumor-bearing mice. These results indicated the translation promise of our self-assembled nanovaccine for immune potentiation and cancer immunotherapy.

A Simple Synthesis of Reduction-Responsive Acrylamide-Type Nanogels for miRNA Delivery

MicroRNAs (miRNAs) have great therapeutic potential; however, their delivery still faces huge challenges, especially given the short half-life of naked miRNAs due to rapid hydrolysis or inactivation by abundant nucleases in the systemic circulation. Therefore, the search for reliable miRNA delivery systems is crucial. Nanogels are one of the more effective nanocarriers because they are biocompatible and have a high drug-loading capacity. In this study, acrylamide-based nanogels containing cationic groups and redox-sensitive crosslinkers were developed for cellular delivery of anti-miR21 (a-miR21). To achieve this, post-polymerization loading of a-miR21 oligonucleotides into nanogels was performed by utilizing the electrostatic interaction between positively charged nanogels and negatively charged oligonucleotides. Different molar ratios of the amine groups (N) on the cationic nanogel and phosphate groups (P) on the miRNA were investigated. An N/P ratio of 2 allowed high miRNA loading capacity (MLC, 6.7% w/w) and miRNA loading efficiency (MLE, 99.7% w/w). Successful miRNA loading was confirmed by dynamic light scattering (DLS) and electrophoretic light scattering (ELS) measurements. miRNA-loaded nanogels (NG/miRNA) formed stable dispersions in biological media and showed an enhanced miRNA release profile in the presence of glutathione (GSH). Moreover, the addition of heparin to dissociate the miRNA from the cationic nanogels resulted in the complete release of miRNA. Lastly, a cell uptake study indicated that NG/miRNA could be easily taken up by cancer cells.

Gene-activated titanium implants for gene delivery to enhance osseointegration

Osseointegration is the direct and intimate contact between mineralized tissue and titanium implant at the bone-implant interface. Early establishment and stable maintenance of osseointegration is the key to long-term implant success. However, in patients with compromised conditions such as osteoporosis and patients beginning early load-bearing activities such as walking, lower osseointegration around titanium implants is often observed, which might result in implant early failure. Gene-activated implants show an exciting prospect of combining gene delivery and biomedical implants to solve the problems of poor osseointegration formation, overcoming the shortcomings of protein therapy, including rapid degradation and overdose adverse effects. The conception of gene-activated titanium implants is based on "gene-activated matrix" (GAM), which means scaffolds using non-viral vectors for in situ gene delivery to achieve a long-term and efficient transfection of target cells. Current preclinical studies in animal models have shown that plasmid DNA (pDNA), microRNA (miRNA), and small interference RNA (siRNA) functionalized titanium implants can enhance osseointegration with safety and efficiency, leading to the expectation of applying this technique in dental and orthopedic clinical scenarios. This review aims to comprehensively summarize fabrication strategies, current applications, and futural outlooks of gene-activated implants, emphasizing nucleic acid targets, non-viral vectors, implant surface modification techniques, nucleic acid/vector complexes loading strategies.

Hierarchical self-uncloaking CRISPR-Cas13a-customized RNA nanococoons for spatial-controlled genome editing and precise cancer therapy

CRISPR-Cas13a holds enormous potential for developing precise RNA editing. However, spatial manipulation of CRISPR-Cas13a activity remains a daunting challenge for elaborately regulating localized RNase function. Here, we designed hierarchical self-uncloaking CRISPR-Cas13a-customized RNA nanococoons (RNCOs-D), featuring tumor-specific recognition and spatial-controlled activation of Cas13a, for precise cancer synergistic therapy. RNCOs-D consists of programmable RNA nanosponges (RNSs) capable of targeted delivery and caging chemotherapeutic drug, and nanocapsules (NCs) anchored on RNSs for cloaking Cas13a/crRNA ribonucleoprotein (Cas13a RNP) activity. The acidic endo/lysosomal microenvironment stimulates the outer decomposition of NCs with concomitant Cas13a RNP activity revitalization, while the inner disassembly through trans-cleavage of RNSs initiated by cis-recognition and cleavage of EGFR variant III (EGFRvIII) mRNA. RNCOs-D demonstrates the effective EGFRvIII mRNA silencing for synergistic therapy of glioblastoma cancer cells in vitro and in vivo. The engineering of RNSs, together with efficient Cas13a activity regulation, holds immense prospect for multimodal and synergistic cancer therapy.

Construction and application of star polycation nanocarrier-based microRNA delivery system in Arabidopsis and maize

Background

MicroRNA (miRNA) plays vital roles in the regulation of both plant architecture and stress resistance through cleavage or translation inhibition of the target messenger RNAs (mRNAs). However, miRNA-induced gene silencing remains a major challenge in vivo due to the low delivery efficiency and instability of miRNA, thus an efficient and simple method is urgently needed for miRNA transformation. Previous researches have constructed a star polycation (SPc)-mediated transdermal double-stranded RNA (dsRNA) delivery system, achieving efficient dsRNA delivery and gene silencing in insect pests.

Results

Here, we tested SPc-based platform for direct delivery of double-stranded precursor miRNA (ds-MIRNA) into protoplasts and plants. The results showed that SPc could assemble with ds-MIRNA through electrostatic interaction to form nano-sized ds-MIRNA/SPc complex. The complex could penetrate the root cortex and be systematically transported through the vascular tissue in seedlings of Arabidopsis and maize. Meanwhile, the complex could up-regulate the expression of endocytosis-related genes in both protoplasts and plants to promote the cellular uptake. Furthermore, the SPc-delivered ds-MIRNA could efficiently increase mature miRNA amount to suppress the target gene expression, and the similar phenotypes of Arabidopsis and maize were observed compared to the transgenic plants overexpressing miRNA.

Conclusion

To our knowledge, we report the first construction and application of star polycation nanocarrier-based platform for miRNA delivery in plants, which explores a new enable approach of plant biotechnology with efficient transformation for agricultural application.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01443-4.

Intelligent Gold Nanoparticles with Oncogenic MicroRNA-Dependent Activities to Manipulate Tumorigenic Environments for Synergistic Tumor Therapy

Tumorigenic environments, especially aberrantly overexpressed oncogenic microRNAs, play a critical role in various activities of tumor progression. However, developing strategies to effectively utilize and manipulate these oncogenic microRNAs for tumor therapy is still a challenge. To address this challenge, spherical nucleic acids (SNAs) consisting of gold nanoparticles in the core and antisense oligonucleotides as the shell are fabricated. Hybridized to the oligonucleotide shell is a DNA sequence to which doxorubicin is conjugated (DNA-DOX). The oligonucleotides shell is designed to capture overexpressed miR-21/miR-155 and inhibit the expression of these oncogenic miRNAs in tumor cells after tumor accumulation to manipulate genetic environment for accurate gene therapy. This process further induces the aggregation of these SNAs, which not only generates photothermal agents to achieve on-demand photothermal therapy in situ, but also enlarges the size of SNAs to enhance the retention time in the tumor for sustained therapy. The capture of the relevant miRNAs simultaneously triggers the intracellular release of the DNA-DOX from the SNAs to deliver tumor-specific chemotherapy. Both in vivo and in vitro results indicate that this combination strategy has excellent tumor inhibition properties with high survival rate of tumor-bearing mice, and can thus be a promising candidate for effective tumor treatment.

Signaling Pathway Inhibitors, miRNA, and Nanocarrier-Based Pharmacotherapeutics for the Treatment of Lung Cancer: A Review

Lung cancer is one of the most commonly diagnosed cancers and is responsible for a large number of deaths worldwide. The pathogenic mechanism of lung cancer is complex and multifactorial in origin. Thus, various signaling pathways as targets for therapy are being examined, and many new drugs are in the pipeline. However, both conventional and target-based drugs have been reported to present significant adverse effects, and both types of drugs can affect the clinical outcome in addition to patient quality of life. Recently, miRNA has been identified as a promising target for lung cancer treatment. Therefore, miRNA mimics, oncomiRs, or miRNA suppressors have been developed and studied for possible anticancer effects. However, these miRNAs also suffer from the limitations of low stability, biodegradation, thermal instability, and other issues. Thus, nanocarrier-based drug delivery for the chemotherapeutic drug delivery in addition to miRNA-based systems have been developed so that existing limitations can be resolved, and enhanced therapeutic outcomes can be achieved. Thus, this review discusses lung cancer's molecular mechanism, currently approved drugs, and their adverse effects. We also discuss miRNA biosynthesis and pathogenetic role, highlight pre-clinical and clinical evidence for use of miRNA in cancer therapy, and discussed limitations of this therapy. Furthermore, nanocarrier-based drug delivery systems to deliver chemotherapeutic drugs and miRNAs are described in detail. In brief, the present review describes the mechanism and up-to-date possible therapeutic approaches for lung cancer treatment and emphasizes future prospects to bring these novel approaches from bench to bedside.

Nanotherapeutics Overcoming the Blood-Brain Barrier for Glioblastoma Treatment

Glioblastoma (GBM) is the most common malignant primary brain tumor with a poor prognosis. The current standard treatment regimen represented by temozolomide/radiotherapy has an average survival time of 14.6 months, while the 5-year survival rate is still less than 5%. New therapeutics are still highly needed to improve the therapeutic outcome of GBM treatment. The blood-brain barrier (BBB) is the main barrier that prevents therapeutic drugs from reaching the brain. Nanotechnologies that enable drug delivery across the BBB hold great promise for the treatment of GBM. This review summarizes various drug delivery systems used to treat glioma and focuses on their approaches for overcoming the BBB to enhance the accumulation of small molecules, protein and gene drugs, etc. in the brain.

Early administration of MPC-n(IVIg) selectively accumulates in ischemic areas to protect inflammation-induced brain damage from ischemic stroke

Ischemic stroke is an acute and severe neurological disease, which leads to disability and death. Immunomodulatory therapies exert multiple remarkable protective effects during ischemic stroke. However, patients suffering from ischemic stroke do not benefit from immunomodulatory therapies due to the presence of the blood-brain barrier (BBB) and their off-target effects. Methods: We presented a delivery strategy to optimize immunomodulatory therapies by facilitating BBB penetration and selectively delivering intravenous immunoglobulin (IVIg) to ischemic regions using 2-methacryloyloxyethyl phosphorylcholine (MPC)-nanocapsules, MPC-n(IVIg), synthesized using MPC monomers and ethylene glycol dimethyl acrylate (EGDMA) crosslinker via in situ polymerization. In vitro and in vivo experiments verify the effect and safety of MPC-n(IVIg). Results: MPC-n(IVIg) efficiently crosses the BBB and IVIg selectively accumulates in ischemic areas in a high-affinity choline transporter 1 (ChT1)-overexpression dependent manner via endothelial cells in ischemic areas. Moreover, earlier administration of MPC-n(IVIg) more efficiently deliver IVIg to ischemic areas. Furthermore, the early administration of low-dosage MPC-n(IVIg) decreases neurological deficits and mortality by suppressing stroke-induced inflammation in the middle cerebral artery occlusion model. Conclusion: Our findings indicate a promising strategy to efficiently deliver the therapeutics to the ischemic target brain tissue and lower the effective dose of therapeutic drugs for treating ischemic strokes.

Dual ATP/reduction-responsive polyplex to achieve the co-delivery of doxorubicin and miR-23b for the cancer treatment

Combination therapy based on the co-delivery of therapeutic genes and anti-cancer drugs has emerged as a promising approach in the cancer treatment, and stimuli-responsive delivery systems could further improve the therapeutic efficacy. Herein, an ATP aptamer and its complementary DNA were used to form Duplex into which doxorubicin (DOX) was loaded to construct DOX-Duplex, and then the lipoic acid-modified oligoethyleneimine (LA-OEI) was employed as a carrier to realize the co-delivery of DOX-Duplex and miR-23b. The ternary nanocomplex LA-OEI/miR-23b/DOX-Duplex showed excellent anti-proliferative effect by inducing the cell apoptosis via mitochondrial signaling pathway and arresting the cell cycle at S phase. Meanwhile, the co-delivery of DOX-Duplex and miR-23b could efficiently inhibit the metastasis of cancer cells by reducing the expression level of MMP-9. The favorable anti-tumor efficacy of ternary nanocomplex was attributed to the rapid drug release in response to intracellular ATP concentration and reduction conditions and the synergistic effect between DOX-Duplex and miR-23b. Thus, ATP aptamer and reduction-responsive polymer provided a convenient platform to construct dual stimuli-responsive systems for the co-delivery of gene and drug in the cancer treatment.

Efficient and precise delivery of microRNA by photoacoustic force generated from semiconducting polymer-based nanocarriers

One major challenge in miRNA-based therapy is to explore facile delivery strategies, which can facilitate the efficient and precise accumulation of intrinsically instable microRNAs (miRNAs) at targeted tumor sites. To address this critical issue, for the first time we demonstrate that a near-infrared (NIR) pulse laser can guide efficient delivery of miRNAs mediated by a NIR-absorbing and photoacoustic active semiconducting polymer (SP) nanocarrier, which can generate photoacoustic radiation force to intravascularly overcome the endothelial barriers. Importantly, we demonstrate an ultrafast delivery of miRNA (miR-7) to tumor tissues under the irradiation of pulse laser in 20 min, showing a 5-fold boosted efficiency in comparison to the traditional passive targeting strategy. The delivered miR-7 acts as a sensitizer of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and synergizes with TRAIL-inducing compound (TIC), leading to sustained TRAIL upregulation for effective tumor suppression in mice. As such, our results indicate that the NIR-absorbing semiconducting polymer-mediated nanocarrier platform can significantly enhance the targeted delivery efficiency of therapeutic miRNAs to tumors, resulting in potent tumor growth inhibition.

Phosphatidylcholine-Engineered Exosomes for Enhanced Tumor Cell Uptake and Intracellular Antitumor Drug Delivery

Exosomes derived from non-tumor cells hold great potential as drug delivery vehicles because of their good biosafety and natural transference of bioactive cargo between cells. However, compared to tumor-derived exosomes, efficient delivery is limited by their weak interactions with tumor cells. It is essential to engineer exosomes that improve tumor cellular internalization efficiency. A simple and effective strategy to enhance tumor cell uptake by engineering the exosome membrane lipids can be established by drawing on the role of lipids in tumor exosomes interacting with tumor cells. Amphiphilic phosphatidylcholine (PC) molecules are inserted into the membrane lipid layer of reticulocyte-derived exosomes (Exos) by simple incubation to construct PC-engineered exosomes (PC-Exos). It is demonstrated that PC-Exos showed significantly enhanced tumor cell internalization and uptake rate compared to native Exos, up to a twofold increase. After therapeutic agent loading, PC-Exos remarkably promotes intracellular drug or RNA accumulation in cancer cells, thus showing enhanced in vitro anti-tumor activity. This work demonstrates the crucial role of engineering exosomal lipids in modulating cancer cellular uptake, which may shed light on the design of high-efficiency exosome-based drug delivery carriers.

Calixarene-Embedded Nanoparticles for Interference-Free Gene-Drug Combination Cancer Therapy

Combination therapy based on molecular drugs and therapeutic genes provides an effective strategy for malignant tumor treatment. However, effective gene and drug combinations for cancer treatment are limited by the widespread antagonism between therapeutic genes and molecular drugs. Herein, a calixarene-embedded nanoparticle (CENP) is developed to co-deliver molecular drugs and therapeutic genes without compromising their biological functions, thereby achieving interference-free gene-drug combination cancer therapy. CENP is composed of a cationic polyplex core and an acid-responsive polymer shell, allowing CENP loading and delivering therapeutic genes with improved circulation stability and enhanced tumor accumulation. Moreover, the introduction of carboxylated azocalix[4]arene, which is a hypoxia-responsive calixarene derivatives, in the polyplex core endows CENP with the capability to load molecular drugs through the host-guest complexation as well as inhibit the interference between the drugs and genes by encapsulating the drugs into its cavity. By loading doxorubicin and a plasmid DNA-based CRISPR interference system that targets miR-21, CENP exhibits the significantly enhanced anti-tumor effects in mice. Considering the wide variety of calixarene derivatives, CENP can be adapted to deliver almost any combination of drugs and genes, providing the potential as a universal platform for the development of interference-free gene-drug combination cancer therapy.

The effect of zwitterionic surface content on blood circulation time of nanocapsule

Zwitterionic modification can prolong the blood circulation time of nanocarrier in vivo, but zwitterionic content will affect the functions of nanocarrier such as enzyme-responsive and intracellular or extracellular delivery. Therefore, it is necessary to explore the relationship between the zwitterionic content and circulation time of nanocarrier so as to figure out what content of zwitterion can enable the nanocarrier to obtain both the long blood circulation ability and other functions mentioned above. Herein, using nanocapsule as a research model, we investigated the nanocapsule modified with zwitterion of phosphorylcholine (PC) or carboxybetaine (CB) respectively, and through ¹H-NMR quantification we determined the zwitterionic surface content, so as to study the effect of PC or CB surface content on blood circulation performance of nanocapsule. In vivo study showed that the nanocapsule possessed an optimal surface filling ratios range for blood circulation of 43-68% for PC and of 20-68% for CB, with the longest t_1/2=37.35 h for PC-nanocapsule and t_1/2=45.27 h for CB-nanocapsule. Furthermore, the protein adsorption and macrophage endocytosis experiments indicated that when the surface filling ratio reached 43% for PC-nanocapsule and 20% for CB-nanocapsule, it could effectively reduce the protein adsorption and weaken macrophage endocytosis, thus explaining the phenomenon of long circulation time of nanocapsules from the point of protein adsorption and interaction with immune cells. This study proposes a new direction for designing long-circulating nanocarrier, and provides basis for constructing enzyme-responsive and intracellular or extracellular delivery platform.

MiR-21 nanocapsules promote early bone repair of osteoporotic fractures by stimulating the osteogenic differentiation of bone marrow mesenchymal stem cells

Objective

The healing of osteoporotic fractures in the elderly patients is a difficult clinical problem. Currently, based on the internal fixation of fractures, the available drug treatments mainly focus on either inhibiting osteoclast function, such as bisphosphonate, calcitonin, oestrogen or promoting osteogenesis, such as parathyroid hormones. However, the availability of current antiosteoporotic drugs in promoting osteoporotic fracture healing is limited. The objective of the present study was to investigate the ability of the MiR-21/nanocapsule to enhance the early bone repair of osteoporotic fractures.

Methods

Based on the presence of matrix metalloproteinases that are overexpressed at the fracture site, we designed the matrix metalloproteinase–sensitive nanocapsules which were formed by in situ free radical polymerisation on the surface of MiR-21 with 2-(methacryloyloxy) ethyl phosphorylcholine and the bisacryloylated VPLGVRTK peptide. The MiR-21/nanocapsule [n (miR-21)] and O-carboxymethyl chitosan (CMCS) were mixed until they formed a gel-like material [CMCS/n (miR-21)] with good fluidity and injectability. Thirty elderly Sprague Dawley (SD) rats (female, 14-month-old, 380 ± 10 g) were subjected to bilateral removal of the ovaries (ovariectomised). All rats were subjected to bilateral bone defects (2 mm diameter) of the proximal tibia and randomly divided into three groups (groups A, B, and C): separately injected with CMCS/n (miR-21), CMCS/n (NC-miR), and saline. Micro-computed tomography (CT) imaging was performed to evaluate newly formed bone volume and connectivity. Nondecalcified histology and toluidine blue staining were performed to measure the effects of CMCS/n (miR-21) on bone repair. In vitro, the effect of n (miR-21) on osteogenic differentiation to bone marrow mesenchymal stem cells (BMSCs) which derived from the ovariectomised rat model was observed.

Results

The morphology of n (miR-21) was a regular spherical nanocapsule with a uniform small size (25–35 nm). The results confirmed that n (miR-21) could be efficiently phagocytosed by BMSCs and released in the cytoplasm to promote osteogenesis. The expression level of alkaline phosphatase and Runt-related transcription factor 2 mRNA in the n (miR-21) group was higher than that in the n (NC-miR) group. Animal experiments proved that CMCS/n (miR-21) produced better bone repair compared with the CMCS/n (NC-miR) group in the early stages of fracture healing at 4 weeks. In the late stage of fracture healing (8 weeks), micro-CT quantitative analysis showed that the new bone trabeculae in the CMCS/n (miR-21) group has decreased compared with the CMCS/n (NC-miR) group. In the CMCS/n (miR-21) group, the new cancellous bone had been absorbed, and the process of bone healing was almost completed. In contrast, the new bone in the CMCS/n (NC-miR) and the control groups was still in the healing process.

Conclusion

The cytological tests confirmed that n (miR-21) can promote osteogenic differentiation of BMSCs derived from the osteoporosis rat model. Furthermore, the results of animal tests demonstrated that local injection of CMCS/n (miR-21) promoted the early healing of osteoporotic bone defects. Consequently CMCS/n (miR-21) promoted the bone repair process to enter the moulding phase earlier.

The translational potential of this article

CMCS/n (miR-21) can be widely applied to elderly patients with osteoporotic fractures. This method can help patients with osteoporotic fractures recover earlier and avoid serious complications. It provides a potential approach for the clinical treatment of osteoporotic fractures in the elderly.

Exosome-mediated microRNA-497 delivery for anti-cancer therapy in a microfluidic 3D lung cancer model

Non-small cell lung cancer (NSCLC) is one of the leading causes of death from cancer worldwide. The delivery and controlled regulation of miRNAs via exosomes is known as a potential therapeutic approach in the treatment of cancer. In this study, human cell-derived exosomes were used as delivery vehicles for miRNAs, and we investigated their anti-tumor and anti-angiogenic effects on NSCLCs that were cultured in 2D and 3D microfluidic devices. We demonstrated that exosomes that contained miRNA-497 (miR-497) effectively suppressed tumor growth and the expression of their associated genes, i.e., yes-associated protein 1 (YAP1), hepatoma-derived growth factor (HDGF), cyclin E1 (CCNE1), and vascular endothelial growth factor-A (VEGF-A), in A549 cells. Also, the level of VEGF-A-mediated angiogenic sprouting was decreased drastically in human umbilical vein endothelial cells (HUVECs) cultured in a microfluidic device. To mimic the in vivo-like tumor microenvironment of NSCLC, A549 cells were co-cultured with HUVECs in a single device, and miR-497-loaded exosomes were delivered to both types of cells. As a result, both the tube formation of endothelial cells and the migration of tumor decreased dramatically compared to the control. This indicated that miR-497 has synergistic inhibitory effects that target tumor growth and angiogenesis, so exosome-mediated miRNA therapeutics combined with the microfluidic technology could be a predictive, cost-efficient translational tool for the development of targeted cancer therapy.

Enhanced Delivery of Rituximab Into Brain and Lymph Nodes Using Timed-Release Nanocapsules in Non-Human Primates

Tumor metastasis into the central nervous system (CNS) and lymph nodes (LNs) is a major obstacle for effective therapies. Therapeutic monoclonal antibodies (mAb) have revolutionized tumor treatment; however, their efficacy for treating metastatic tumors-particularly, CNS and LN metastases-is poor due to inefficient penetration into the CNS and LNs following intravenous injection. We recently reported an effective delivery of mAb to the CNS by encapsulating the anti-CD20 mAb rituximab (RTX) within a thin shell of polymer that contains the analogs of choline and acetylcholine receptors. This encapsulated RTX, denoted as n-RTX, eliminated lymphoma cells systemically in a xenografted humanized mouse model using an immunodeficient mouse as a recipient of human hematopoietic stem/progenitor cells and fetal thymus more effectively than native RTX; importantly, n-RTX showed notable anti-tumor effect on CNS metastases which is unable to show by native RTX. As an important step toward future clinical translation of this technology, we further analyzed the properties of n-RTX in immunocompetent animals, rats, and non-human primates (NHPs). Our results show that a single intravenous injection of n-RTX resulted in 10-fold greater levels in the CNS and 2-3-fold greater levels in the LNs of RTX, respectively, than the injection of native RTX in both rats and NHPs. In addition, we demonstrate the enhanced delivery and efficient B-cell depletion in lymphoid organs of NHPs with n-RTX. Moreover, detailed hematological analysis and liver enzyme activity tests indicate n-RTX treatment is safe in NHPs. As this nanocapsule platform can be universally applied to other therapeutic mAbs, it holds great promise for extending mAb therapy to poorly accessible body compartments.

SPION decorated exosome delivery of TNF-α to cancer cell membranes through magnetism

Tumor necrosis factor (TNF-α) is capable of inducing apoptosis and is a promising candidate for genetic engineering drugs in cancer therapy; however, the serious side-effects of TNF-α hinder their clinical application. In the present study, a method for preparing fusion proteins of cell-penetrating peptides (CPP) and TNF-α (CTNF-α)-anchored exosomes coupled with superparamagnetic iron oxide nanoparticles (CTNF-α-exosome-SPIONs) with membrane targeting anticancer activity has been demonstrated. To acquire exosomes with TNF-α anchored in its membrane, a CTNF-α expression vector was constructed and a stable mesenchymal stem cell cell line that expressed CTNF-α was established. Conjugating transferrin-modified SPIONs (Tf-SPIONs) onto CTNF-α-exosomes through transferrin-transferrin receptor (Tf-TfR) interaction yields CTNF-α-exosome-SPIONs with good water dispersibility. The incorporation of TNF-α into exosomes and the conjugation of SPIONs significantly enhanced the binding capacity of TNF-α to its membrane-bound receptor TNFR I, thus increasing the therapeutic effects. CTNF-α-exosome-SPIONs significantly enhanced tumor cell growth inhibition via induction of the TNFR I-mediated apoptotic pathway. In vivo studies using murine melanoma subcutaneous cancer models showed that TNF-α-loaded exosome-based vehicle delivery enhanced cancer targeting under an external magnetic field and suppressed tumor growth with mitigating toxicity. Taken together, our results suggest that CTNF-α-exosome-SPIONs showed great potential in membrane targeting therapy.

GLUT1-mediated effective anti-miRNA21 pompon for cancer therapy

Oncogenic microRNAs are essential components in regulating the gene expression of cancer cells. Especially miR21, which is a major player involved of tumor initiation, progression, invasion and metastasis in several cancers. The delivery of anti-miR21 sequences has significant potential for cancer treatment. Nevertheless, since anti-miR21 sequences are extremely unstable and they need to obtain certain concentration to function, it is intensely difficult to build an effective delivery system for them. The purpose of this work is to construct a self-assembled glutathione (GSH)-responsive system with tumor accumulation capacity for effective anti-miR21 delivery and cancer therapy. A novel drug delivery nanosphere carrying millions of anti-miR21 sequences was developed through the rolling circle transcription (RCT) method. GSH-responsive cationic polymer polyethyleneimine (pOEI) was synthesized to protect the nanosphere from degradation by Dicer or other RNase in normal cells and optimize the pompon-like nanoparticle to suitable size. Dehydroascorbic acid (DHA), a targeting molecule, which is a substrate of glucose transporter 1 (GLUT 1) and highly expressed on malignant tumor cells, was connected to pOEI through PEG, and then the polymer was used for contracting a RNA nanospheres into nanopompons. The anti-miR21 nanopompons showed its potential for effective cancer therapy.

A Multifunctional Peptide-Conjugated AIEgen for Efficient and Sequential Targeted Gene Delivery into the Nucleus

Gene therapy has immense potential as a therapeutic approach to serious diseases. However, efficient delivery and real-time tracking of gene therapeutic agents have not been solved well for successful gene-based therapeutics. Herein we present a versatile gene-delivery strategy for efficient and visualized delivery of therapeutic genes into the targeted nucleus. We developed an integrin-targeted, cell-permeable, and nucleocytoplasmic trafficking peptide-conjugated AIEgen named T_D NCP for the efficient and sequential targeted delivery of an antisense single-stranded DNA oligonucleotide (ASO) and tracking of the delivery process into the nucleus. As compared with T_D NCP/siRNA-NPs (siRNA functions mainly in the cytoplasm), T_D NCP/ASO-NPs (ASO functions mainly in the nucleus) exhibited a better interference effect, which further indicates that T_D NCP is a nucleus-targeting vector. Moreover, T_D NCP/ASO-NPs showed a favorable tumor-suppressive effect in vivo.

Enhancing the In Vitro and In Vivo Stabilities of Polymeric Nucleic Acid Delivery Nanosystems

Gene therapy holds great promise for various medical and biomedical applications. Nonviral gene delivery systems formed by cationic polymer and nucleic acids (e.g., polyplexes) have been extensively investigated for targeted gene therapy; however, their in vitro and in vivo stability is affected by both their intrinsic properties such as chemical compositions (e.g., polymer molecular weight and structure, and N/P ratio) and a number of environmental factors (e.g., shear stress during circulation in the bloodstream, interaction with the serum proteins, and physiological ionic strength). In this review, we surveyed the effects of a number of important intrinsic and environmental factors on the stability of polymeric gene delivery systems, and discussed various strategies to enhance the stability of polymeric gene delivery systems, thereby enabling efficient gene delivery into target cells. Future opportunities and challenges of polymeric nucleic acid delivery nanosystems were also briefly discussed.

Current Progress on MicroRNA-Based Gene Delivery in the Treatment of Osteoporosis and Osteoporotic Fracture

Emerging evidence demonstrates that microRNAs, as important endogenous posttranscriptional regulators, are essential for bone remodeling and regeneration. Undoubtedly, microRNA-based gene therapies show great potential to become novel approaches against bone-related diseases, including osteoporosis and associated fractures. The major obstacles for continued advancement of microRNA-based therapies in clinical application include their poor in vivo stability, nonspecific biodistribution, and unwanted side effects. Appropriate chemical modifications and delivery vectors, which improve the biological performance and potency of microRNA-based drugs, hold the key to translating miRNA technologies into clinical practice. Thus, this review summarizes the current attempts and existing deficiencies of chemical modifications and delivery systems applied in microRNA-based therapies for osteoporosis and osteoporotic fractures to inform further explorations.

The adaptive potential of RNA editing-mediated miRNA-retargeting in cancer

A-to-I RNA editing is a post-transcriptional mechanism that converts the genomically coded Adenosine (A) into Inosine (I) at the RNA level. This type of RNA editing is the most frequent in humans and is mediated by the ADAR enzymes. RNA editing can alter the genetic code of mRNAs, but also affect the functions of noncoding RNAs such as miRNAs. Recent studies have identified thousands of microRNA editing events in different cancer types. However, the important role played by miRNA-editing in cancer has been reported for just a few microRNAs. Herein, we recapitulate the current studies on cancer-related microRNA editing and discuss their importance in tumor growth and progression. This article is part of a Special Issue entitled: mRNA modifications in gene expression control edited by Dr. Soller Matthias and Dr. Fray Rupert.

Overview upon miR-21 in lung cancer: focus on NSCLC

Considering the high mortality rate encountered in lung cancer, there is a strong need to explore new biomarkers for early diagnosis and also improved therapeutic targets to overcome this issue. The implementation of microRNAs as important regulators in cancer and other pathologies expanded the possibilities of lung cancer management and not only. MiR-21 represents an intensively studied microRNA in many types of cancer, including non-small cell lung cancer (NSCLC). Its role as an oncogene is underlined in multiple studies reporting the upregulated expression of this sequence in patients diagnosed with this malignancy; moreover, several studies associated this increased expression of miR-21 with a worse outcome within NSCLC patients. The same pattern is supported by the data existent in the Cancer Genome Atlas (TCGA). The carcinogenic advantage generated by miR-21 in NSCLC resides in the target genes involved in multiple pathways such as cell growth and proliferation, angiogenesis, invasion and metastasis, but also chemo- and radioresistance. Therapeutic modulation of miR-21 by use of antisense sequences entrapped in different delivery systems has shown promising results in impairment of NSCLC. Hereby, we review the mechanisms of action of miR-21 in cancer and the associated changes upon tumor cells together a focused perspective on NSCLC signaling, prognosis and therapy.

Capturing intracellular oncogenic microRNAs with self-assembled DNA nanostructures for microRNA-based cancer therapy

Aberrantly overexpressed oncogenic microRNAs (miRNAs, miRs) are excellent targets for therapeutic interventions.

Aberrantly overexpressed oncogenic microRNAs (miRNAs, miRs) are excellent targets for therapeutic interventions. Nevertheless, thus far, little progress has been made in developing miRNA-based drugs and techniques for clinical applications, especially for overexpressed miRNAs. In this study, we demonstrate that self-assembled DNA nanostructures bearing multiple DNA sequences that are complementary to a target miRNA can effectively capture the overexpressed oncogenic miRNA and subsequently inhibit cancer cell proliferation. Specifically, a DNA nanotube structure that carries functional DNA segments (single-stranded, duplex and hairpin forms) was designed and synthesized to capture two well-known overexpressed miRNAs, miR-21 and miR-155. It was found that all three DNA nanotubes significantly reduced both miRNA levels and inhibited cancer cell growth. Moreover, the capture efficiency was highly concentration dependent and was associated with the structural design of the DNA nanotube. These results demonstrate that through careful design, programmable DNA nanostructures can hijack the natural cellular machinery and can serve as nucleic acid drugs themselves. The concept of using self-assembled DNA nanostructures to disrupt the intracellular machinery for therapeutic purposes opens a new paradigm for exploiting self-assembled DNA nanostructures for miRNA-based anticancer therapy.

A dual-targeting reconstituted high density lipoprotein leveraging the synergy of sorafenib and antimiRNA21 for enhanced hepatocellular carcinoma therapy

Sorafenib (So) is a multi-target kinase inhibitor extensively used in clinic for hepatocellular carcinoma therapy. It demonstrated strong inhibition both in tumor proliferation and tumor angiogenesis, while hampered by associated cutaneous side-effect and drug resistance. The knockdown of miR-21 with antisense oligonucleotides (antimiRNA21) was regarded as an efficient strategy for increasing tumor sensibility to chemotherapy, which could be employed to appreciate the efficacy of So. Herein, we successfully formulated a dual-targeting delivery system for enhanced hepatocellular carcinoma therapy by encapsulating So and antimiRNA21 in RGD pentapeptide-modified reconstituted high-density lipoprotein (RGD-rHDL/So/antimiRNA21). The RGD and apolipoprotein A-I (ApoA-I) on nanoparticles (NPs) could drive the system simultaneously to tumor neovascular and parenchyma by binding to the overexpressed ανβ3-integrin and SR-B1 receptors, achieving precise delivery of therapeutics to maximize the efficacy. A series in vitro and in vivo experiments revealed that co-delivery of So and antimiRNA21 by RGD-rHDL significantly strengthened the anti-tumor and anti-angiogenic effect of So with negligible toxicity towards major organs, reversed drug-resistance and was capable of remodeling tumor environments. The constructed RGD-rHDL/So/antimiRNA21 with improved efficacy and excellent tumor targeting ability provided new idea for chemo-gene combined therapy in hepatocellular carcinoma.

STATEMENT OF SIGNIFICANCE

Sorafenib (So) is a multi-target kinase inhibitor which was approved by FDA as first-line drug for hepatocellular carcinoma (HCC) therapy. However, long term application of So in clinic was hampered by serious dermal toxicity and drug resistance. Although numerous researchers were devoted to finding alternatives or therapies as combination treatments with So to reach more desired therapeutic efficacy, the therapeutic options were still limited. The present study prepares RGD pentapeptide decorated biomimic reconstituted high-density lipoprotein (rHDL) loaded with So and antimiRNA21 (RGD-rHDL/So/antimiRNA21) for enhanced HCC therapy. The RGD-rHDL/So/antimiRNA21 NPs offer an effective platform for anti-tumor and anti-angiogenesis therapy in HCC and provide new approach to reverse drug-resistance of So for feasible clinical application.

Collagenase nanocapsules: An approach to fibrosis treatment

Fibrosis is a common lesion in different pathologic diseases and defined by the excessive accumulation of collagen. Different approaches have been used to treat different conditions characterized by fibrosis. The FDA and EMA approved the use of collagenase to treat palmar fibromatosis (Dupuytren's contracture). The EMA approved additionally its use in severe Peyronie's disease, but it has been used off label in other conditions [1,2]. The approved treatment includes up to three (in palmar fibromatosis) or up to eight (in penile fibromatosis) injections followed by finger extension or penile modeling procedures, typically causing severe pain. Frequent single injections are adequate to treat palmar fibromatosis [3]. The need to repeatedly inject doses of this enzyme can be due to the labile nature of collagenase, which exhibits a complete activity loss after a short period of time. This study presents a novel strategy to manage this enzyme based on the synthesis of polymeric nanocapsules that contain collagenase encapsulated within their matrix. These nanocapsules have been engineered for achieving a gradual release of the encapsulated enzyme for a longer time, which can be up to ten days. The efficacy of these nanocapsules has been tested in a murine model of local dermal fibrosis, and the results demonstrate a reduction in fibrosis greater than that with the injection of free enzyme; this type of treatment showed a significant improvement compared to conventional therapy of free collagenase.

STATEMENT OF SIGNIFICANCE

The use of proteins as therapeutic molecules has recently attracted great interest. Collagenase injection is the current treatment for fibrotic diseases. Unfortunately, proteins have a low stability and presume several repetition cycles to obtain an effective treatment. This article describes a novel treatment for these types of diseases using collagenase nanocapsules designed to exhibit a sustainable release of the encapsulated enzyme, which maintains the enzymatic activity for a long period of time. The therapeutic effect of nanocapsules was tested in a murine mouse model of local dermal fibrosis, and the results showed an important improved effect compared to the effect of the administration of free enzyme. These results indicate a high potential for this novel system to improve the current treatment for fibrotic diseases.

Nanotechnological Strategies for Protein Delivery

The use of therapeutic proteins plays a fundamental role in the treatment of numerous diseases. The low physico-chemical stability of proteins in physiological conditions put their function at risk in the human body until they reach their target. Moreover, several proteins are unable to cross the cell membrane. All these facts strongly hinder their therapeutic effect. Nanomedicine has emerged as a powerful tool which can provide solutions to solve these limitations and improve the efficacy of treatments based on protein administration. This review discusses the advantages and limitations of different types of strategies employed for protein delivery, such as PEGylation, transport within liposomes or inorganic nanoparticles or their in situ encapsulation.

In Situ Monitoring of MicroRNA Replacement Efficacy and Accurate Imaging-Guided Cancer Therapy through Light-Up Inter-Polyelectrolyte Nanocomplexes

Replacement of downregulated tumor-suppressive microRNA (Ts-miRNA) is recognized as an alternative approach for tumor gene therapy. However, in situ monitoring of miRNA replacement efficacy in a real-time manner via noninvasive imaging is continually challenging. Here, glutathione (GSH)-activated light-up peptide-polysaccharide-inter-polyelectrolyte nanocomplexes are established through self-assembly of carboxymethyl dextran with disulfide-bridged ("S-S") oligoarginine peptide (S-Arg4), in which microRNA-34a (miR-34a) and indocyanine green (ICG) are simultaneously embedded and the nanocomplexes are subsequently stabilized by intermolecular cross-linking. Upon confinement within the robust nanocomplexes, the near-infrared fluorescence (NIRF) of ICG is considerably quenched ("off") due to the aggregation-caused quenching effect. However, after intracellular delivery, the disulfide bond in S-Arg4 can be cleaved by intracellular GSH, which leads to the dissociation of nanocomplexes and triggers the simultaneous release of miR-34a and ICG. The NIRF of ICG is concomitantly activated through dequenching of the aggregated ICG. Very interestingly, a good correlation between time-dependent increase in NIRF intensity and miR-34a replacement efficacy is found in nanocomplexes-treated tumor cells and tumor tissues through either intratumoral or intravenous injections. Systemic nanocomplexes-mediated miR-34a replacement significantly suppresses the growth of HepG-2- and MDA-MB-231-derived tumor xenografts, and provides a pronounced survival benefit in these animal models.

MicroRNAs as novel endogenous targets for regulation and therapeutic treatments

MicroRNAs (miRNAs) are small non-coding RNAs that have been identified as key endogenous biomolecules that are able to regulate gene expression at the post-transcriptional level. The abnormal expression or function of miRNAs has been demonstrated to be closely related to the occurrence or development of various human diseases, including cancers. Regulation of these abnormal miRNAs thus holds great promise for therapeutic treatments. In this review, we summarize exogenous molecules that are able to regulate endogenous miRNAs, including small molecule regulators of miRNAs and synthetic oligonucleotides. Strategies for screening small molecule regulators of miRNAs and recently reported small molecules are introduced and summarized. Synthetic oligonucleotides including antisense miRNA oligonucleotides and miRNA mimics, as well as delivery systems for these synthetic oligonucleotides to enter cells, that regulate endogenous miRNAs are also summarized. In addition, we discuss recent applications of these small molecules and synthetic oligonucleotides in therapeutic treatments. Overall, this review aims to provide a brief synopsis of recent achievements of using both small molecule regulators and synthetic oligonucleotides to regulate endogenous miRNAs and achieve therapeutic outcomes. We envision that these regulators of endogenous miRNAs will ultimately contribute to the development of new therapies in the future.

Artemisinin-Loaded Mesoporous Nanoplatform for pH-Responsive Radical Generation Synergistic Tumor Theranostics

The development of novel and effective cancer treatments will greatly contribute to prolonging and improving patient lives. In this study, a multifunctional nanoplatform was designed and developed based on mesoporous NiO (mNiO) nanoparticles and terbium complexes as an artemisinin (ART) vehicle, a T₂-weighted contrast agent, and a luminescence imaging probe. mNiO is a novel pH-responsive material that can degrade and release nickel ions (Ni²⁺) in an acidic tumor microenvironment. The endoperoxide bridge bond in the structure of ART tends to react with Ni²⁺ to produce radicals that can kill tumor cells. On the basis of its excellent near-infrared absorbance, mNiO can also be considered as a novel photothermal conversion agent for cancer photothermal therapy (PTT). Compared with free ART or PTT only, this novel agent showed remarkably enhanced antitumor activity in cultured cells and in tumor mice models, owing to the hypoxic tumor microenvironment impelling synergistic therapeutic action. These results provide a novel way of using a promising natural drug-based nanoplatform for synergistic therapy of tumors.

The synergistic effect of strontium-substituted hydroxyapatite and microRNA-21 on improving bone remodeling and osseointegration

Surgical failure, mainly caused by loosening implants, causes great mental and physical trauma to patients.

The effects of surface charge on the intra-tumor penetration of drug delivery vehicles with tumor progression

Tumor progression determines the penetrating ability of drug delivery vehicles with different surface charges.