Synergistic MicroRNA Therapy in Liver Fibrotic Rat Using MRI-Visible Nanocarrier Targeting Hepatic Stellate Cells

Bimodal Imaging-Visible Nanomedicine Integrating CXCR4 and VEGFa Genes Directs Synergistic Reendothelialization of Endothelial Progenitor Cells

A major challenge to treat vascular endothelial injury is the restoration of endothelium integrity in which endothelial progenitor cells (EPCs) plays a central role. Transplantation of EPCs as a promising therapeutic means is subject to two interrelated processes, homing and differentiation of EPCs in vivo, and thus a lack of either one may greatly affect the outcome of EPC-based therapy. Herein, a polymeric nanocarrier is applied for the codelivery of CXCR4 and VEGFa genes to simultaneously promote the migration and differentiation of EPCs. Moreover, MRI T2 contrast agent SPION and NIR dye Cy7.5 are also loaded into the nanocarrier in order to track EPCs in vivo. Based on the synergistic effect of the two codelivered genes, an improved reendothelialization of EPCs is achieved in a rat carotid denuded model. The results show the potential of this bimodal imaging-visible nanomedicine to improve the performance of EPCs in repairing arterial injury, which may push forward the stem cell-based therapy of cardiovascular disease.

Recent Advances in Nanomedicine for the Diagnosis and Therapy of Liver Fibrosis

Liver fibrosis, a reversible pathological process of inflammation and fiber deposition caused by chronic liver injury and can cause severe health complications, including liver failure, liver cirrhosis, and liver cancer. Traditional diagnostic methods and drug-based therapy have several limitations, such as lack of precision and inadequate therapeutic efficiency. As a medical application of nanotechnology, nanomedicine exhibits great potential for liver fibrosis diagnosis and therapy. Nanomedicine enhances imaging contrast and improves tissue penetration and cellular internalization; it simultaneously achieves targeted drug delivery, combined therapy, as well as diagnosis and therapy (i.e., theranostics). In this review, recent designs and development efforts of nanomedicine systems for the diagnosis, therapy, and theranostics of liver fibrosis are introduced. Relative to traditional methods, these nanomedicine systems generally demonstrate significant improvement in liver fibrosis treatment. Perspectives and challenges related to these nanomedicine systems translated from laboratory to clinical use are also discussed.

MicroRNA interplay between hepatic stellate cell quiescence and activation

Hepatic stellate cells (HSCs) activation play a significant role in the progression of hepatic fibrosis. During chronic liver diseases, hepatocytes are damaged severely and secrete several pro-inflammatory markers and profibrogenic cytokines via modulation of a variety of signaling pathways that are responsible for the activation of HSCs. The microRNAs (miRNA or miR) have the potential to modulate fibrogenic signaling pathways in HSCs. A variety of miRNAs are identified as profibrogenic and are capable of activating HSCs by modulating fibrosis-associated signaling pathways such as transforming growth factor-β/Smad, Wnt/β-catenin, Hedgehog, Snail and Notch in the injured liver. On the other hand, HSCs also have certain antifibrotic miRNAs and these include miR-16, miR-19b, miR-29, miR-30, miR-101, miR-122, miR-133a, miR-144, miR-146a, miR-150-5p, miR-155, miR-195, miR-200a, miR-214, miR-335, miR-370, miR-454, miR-483, etc. are responsible for maintenance of the quiescent phenotype of normal HSCs, apoptosis induction and phenotypic reversion of activated HSCs, inhibition of HSCs proliferation, suppression of the extracellular matrix-associated gene expressions, etc. Thus, understanding of HSCs specific miRNAs regulation may provide new ideas for the targeted therapy of hepatic fibrosis at molecular level in the near future. Therefore, this review focusses on the modulation of miRNAs profile during the HSCs activation in the fibrotic liver.

Efficient drug and gene delivery to liver fibrosis: rationale, recent advances, and perspectives

Liver fibrosis results from chronic damages together with an accumulation of extracellular matrix, and no specific medical therapy is approved for that until now. Due to liver metabolic capacity for drugs, the fragility of drugs, and the presence of insurmountable physiological obstacles in the way of targeting, the development of efficient drug delivery systems for anti-fibrotics seems vital. We have explored articles with a different perspective on liver fibrosis over the two decades, then collected and summarized the information by providing corresponding in vitro and in vivo cases. We have discussed the mechanism of hepatic fibrogenesis with different ways of fibrosis induction in animals. Furthermore, the critical chemical and herbal anti-fibrotics, biological molecules such as micro-RNAs, siRNAs, and growth factors, which can affect cell division and differentiation, are mentioned. Likewise, drug and gene delivery and therapeutic systems on in vitro and in vivo models are summarized in the data tables. This review article enlightens recent advances in emerging drugs and nanocarriers and represents perspectives on targeting strategies employed in liver fibrosis treatment.

Enhancing the Efficacy of Metal-Free MRI Contrast Agents via Conjugating Nitroxides onto PEGylated Cross-Linked Poly(Carboxylate Ester)

Herein, two water-soluble PROXYL-based magnetic resonance imaging (MRI) macromolecular organic contrast agents (mORCAs) are designed and synthesized: linear and cross-linked PCE-mPEG-Ppa-PROXYL. They are prepared by conjugating linear and cross-linked poly(carboxylate ester) (PCE) with poly(ethylene glycol) (mPEG2000)-modified nitroxides (PROXYL), respectively. Both mORCAs form self-assembled aggregates in an aqueous phase and PROXYL is protected inside a hydrophobic core to achieve great resistance to reduction in the physiological environment, and they have low toxicity. Since cross-linked PCE-mPEG-Ppa-PROXYL possess a branched architecture, its self-assembled aggregate is more stable and compact with a greater particle size. Cross-linked PCE-mPEG-Ppa-PROXYL outperform the linear one in the following aspects: 1) its longitudinal relaxivity (r 1 = 0.79 mm -1 s-1) is higher than that of the linear one (r 1 = 0.64 mm -1 s-1) and both excel the best mORCA reported so far (r 1 = 0.42 mm -1 s-1); 2) its blood retention time (≈48 h) is longer than that of its linear counterpart (≈10 h); 3) cross-linked PCE-mPEG-Ppa-PROXYL provided better MR imaging contrast resolution in normal organs (liver and kidney) and tumor of mice than the linear one. Overall, cross-linked PCE-mPEG-Ppa-PROXYL may have great potential to be a novel metal-free macromolecular contrast agent for MR imaging.

MicroRNA Nanotherapeutics for Lung Targeting. Insights into Pulmonary Hypertension

In this review, the potential future role of microRNA-based therapies and their specific application in lung diseases is reported with special attention to pulmonary hypertension. Current limitations of these therapies will be pointed out in order to address the challenges that they need to face to reach clinical applications. In this context, the encapsulation of microRNA-based therapies in nanovectors has shown improvements as compared to chemically modified microRNAs toward enhanced stability, efficacy, reduced side effects, and local administration. All these concepts will contextualize in this review the recent achievements and expectations reported for the treatment of pulmonary hypertension.

Nuclear-Targeting Delivery of CRISPRa System for Upregulation of β-Defensin against Virus Infection by Dexamethasone and Phenylalanine Dual-Modified Dendrimer

The dual-modified dendrimer containing dexamethasone (DET) and phenylalanine (Phe) was prepared to deliver plasmid DNA encoding dCas9 and single-guide RNA (sgRNA) for specific upregulation of β-defensin. DET and Phe moieties synergistically enhanced the transfection efficiency and reduced cytotoxicity of dendrimers. Combination of three sgRNAs targeting β-defensin gene demonstrated higher activation efficacy of β-defensin than any single sgRNA and combinations of any two sgRNAs, showing an efficient inhibition of virus infection and replication. The titer of vesicular stomatitis virus (VSV) in the cells treated with dCas9-sgRNA targeting β-defensin was reduced by about 100-fold compared to that of cells treated with dCas9-scramble sgRNA (dCas9-scr sgRNA). In vivo experiments demonstrated that the DET- and Phe-modified dendrimer effectively delivered plasmid DNA encoding dCas9 protein into the airway epithelium, inducing β-defensin expression. Delivery of the CRISPR activation system by a dendrimer modified with DET and Phe was a promising approach against viral disease.

Hyperbranched lipoid-based lipid nanoparticles for bidirectional regulation of collagen accumulation in liver fibrosis

Liver fibrosis leads to over one million deaths annually worldwide. Hepatic stellate cells (HSCs) have been identified as the main executors of liver fibrosis. Unfortunately, no drug has yet been approved for clinical use against liver fibrosis, largely because the tested drugs have been unable to access HSCs and efficiently remove the collagen accumulation involved in fibrogenesis. Here, we designed an efficient HSC-targeting lipid delivery system that carried dual siRNAs intended to both inhibit collagen synthesis and promote collagen degradation, with the goal of realizing enhanced anti-liver fibrosis by bidirectional regulation of collagen accumulation. The delivery system was constructed by using amphiphilic cationic hyperbranched lipoids (C₁₅-PA) for siRNA complexation and helper lipoids (cholesterol-polyethylene glycol-vitamin A, Chol-PEG-VA) for HSCs targeting. The generated vitamin A-decorated and hyperbranched lipoid-based lipid nanoparticles (VLNPs) showed excellent gene-binding ability and transfection efficiency, and enhanced the delivery of siRNAs to HSCs. Fibrotic mice treated with dual siRNA-loaded VLNPs showed a great reduction in the collagen accumulation seen in this model; the enhanced effect of bidirectional regulation reduced the collagen accumulation level in treated mice to almost that seen in normal mice. There was no notable sign of toxicity or tissue inflammation in mice exposed to repeated intravenous administration of the dual siRNA-loaded VLNPs. In conclusion, our results indicate that biocompatible VLNPs designed to exploit precise targeting and an effective bidirectional regulation strategy hold promise for treating liver fibrosis.

The role of microRNAs in the pathogenesis, grading and treatment of hepatic fibrosis in schistosomiasis

Schistosomiasis is a prevalent parasitic disease worldwide. The main pathological changes of hepatosplenic schistosomiasis are hepatic granuloma and fibrosis due to worm eggs. Portal hypertension and ascites induced by hepatic fibrosis are usually the main causes of death in patients with chronic hepatosplenic schistosomiasis. Currently, no effective vaccine exists for preventing schistosome infections. For quite a long time, praziquantel (PZQ) was widely used for the treatment of schistosomiasis and has shown benefit in treating liver fibrosis. However, drug resistance and chemical toxicity from PZQ are being increasingly reported in recent years; therefore, new and effective strategies for treating schistosomiasis-induced hepatic fibrosis are urgently needed. MicroRNA (miRNA), a non-coding RNA, has been proved to be associated with the development of many human diseases, including schistosomiasis. In this review, we present a balanced and comprehensive view of the role of miRNAs in the pathogenesis, grading, and treatment of schistosomiasis-associated hepatic fibrosis. The multiple regulatory roles of miRNAs, such as promoting or inhibiting the development of liver pathology in murine schistosomiasis are also discussed in depth. Additionally, miRNAs may serve as candidate biomarkers for diagnosing liver pathology of schistosomiasis and as novel therapeutic targets for treating schistosomiasis-associated hepatic fibrosis.

An Artificial Intelligent Signal Amplification System for in vivo Detection of miRNA

MicroRNAs (miRNA) have been identified as oncogenic drivers and tumor suppressors in every major cancer type. In this work, we design an artificial intelligent signal amplification (AISA) system including double-stranded SQ (S, signal strand; Q, quencher strand) and FP (F, fuel strand; P, protect strand) according to thermodynamics principle for sensitive detection of miRNA in vitro and in vivo. In this AISA system for miRNA detection, strand S carries a quenched imaging marker inside the SQ. Target miRNA is constantly replaced by a reaction intermediate and circulatively participates in the reaction, similar to enzyme. Therefore, abundant fluorescent substances from S and SP are dissociated from excessive SQ for in vitro and in vivo visualization. The versatility and feasibility for disease diagnosis using this system were demonstrated by constructing two types of AISA system to detect Hsa-miR-484 and Hsa-miR-100, respectively. The minimum target concentration detected by the system in vitro (10 min after mixing) was 1/10th that of the control group. The precancerous lesions of liver cancer were diagnosed, and the detection accuracy were larger than 94% both in terms of location and concentration. The ability to establish this design framework for AISA system with high specificity provides a new way to monitor tumor progression and to assess therapeutic responses.

Core-Shell Distinct Nanodrug Showing On-Demand Sequential Drug Release To Act on Multiple Cell Types for Synergistic Anticancer Therapy

Among various inflammatory factors/mediators, autocrine and paracrine prostaglandin 2 (PGE₂), which are abundant in various tumors, promote the proliferation and chemoresistance of cancer cells. Thus, eliminating the cytoprotective effect of PGE₂ may strengthen the antitumor effect of chemotherapy. Chemo/anti-inflammatory combination therapy requires the programmed activities of two different kinds of drugs that critically depend on their spatiotemporal manipulation inside the tumor. Here, a micellar polymeric nanosphere, encapsulating chemotherapeutic paclitaxel (PTX) in the core and conjugating anti-inflammatory celecoxib (CXB) to the shell through a peptide linker (PLGLAG), was developed. The PLGLAG linker was cleavable by the enzyme matrix metalloproteinase-2 (MMP-2) in the tumor tissue, causing CXB release and turning the negatively charged nanosphere into a positively charged one to facilitate PTX delivery into cancer cells. The released CXB not only acted on cyclooxygenase-2 (COX-2) to suppress the production of pro-inflammatory PGE₂ in multiple cell types but also suppressed the expression of the anti-apoptotic Bcl-2 gene to sensitize cancer cells to chemotherapy, thus resulting in a synergistic anticancer effect of PTX and CXB. This study represents an example of using a surface charge-switchable nanosphere with on-demand drug release properties to act on multiple cell types for highly effective chemo/anti-inflammatory combination therapy of cancer.

Targeted Delivery of an siRNA/PNA Hybrid Nanocomplex Reverses Carbon Tetrachloride-Induced Liver Fibrosis

Liver fibrosis is a wound healing process with excessive accumulation of extracellular matrix in the liver. We recently discovered a PCBP2 siRNA that reverses fibrogenesis in activated hepatic stellate cells (HSCs), which are the key players in liver fibrogenesis. However, targeted delivery of siRNAs to HSCs still remains a challenge. Herein, we developed a new strategy to fabricate a multicomponent nanocomplex using siRNA/PNA hybrid instead of chemically conjugated siRNA, thus increasing the scalability and feasibility of the siRNA nanocomplex for animal studies. We modified the nanocomplex with an insulin growth factor 2 receptor (IGF2R)-specific peptide, which specifically binds to activated HSCs. The siRNA nanocomplex shows a controllable size and high serum stability. The nanocomplex also demonstrates high cellular uptake in activated HSCs in vitro and in vivo. Anti-fibrotic activity of the siRNA nanocomplex was evaluated in rats with carbon tetrachloride-induced liver fibrosis. Treatment with the PCBP2 siRNA nanocomplex significantly inhibits the mRNA expressions of PCBP2 and type I collagen in fibrotic liver. Histology study revealed that the siRNA nanocomplex efficiently reduces the protein level of type I collagen and reverses liver fibrosis. Our data suggest that the nanocomplex efficiently delivers the siRNA to fibrotic liver and produces a potent anti-fibrotic effect.