Liver-Targeted siRNA Lipid Nanoparticles Treat Hepatic Cirrhosis by Dual Antifibrotic and Anti-inflammatory Activities

Liver cirrhosis: molecular mechanisms and therapeutic interventions

Liver cirrhosis is the end-stage of chronic liver disease, characterized by inflammation, necrosis, advanced fibrosis, and regenerative nodule formation. Long-term inflammation can cause continuous damage to liver tissues and hepatocytes, along with increased vascular tone and portal hypertension. Among them, fibrosis is the necessary stage and essential feature of liver cirrhosis, and effective antifibrosis strategies are commonly considered the key to treating liver cirrhosis. Although different therapeutic strategies aimed at reversing or preventing fibrosis have been developed, the effects have not be more satisfactory. In this review, we discussed abnormal changes in the liver microenvironment that contribute to the progression of liver cirrhosis and highlighted the importance of recent therapeutic strategies, including lifestyle improvement, small molecular agents, traditional Chinese medicine, stem cells, extracellular vesicles, and gut remediation, that regulate liver fibrosis and liver cirrhosis. Meanwhile, therapeutic strategies for nanoparticles are discussed, as are their possible underlying broad application and prospects for ameliorating liver cirrhosis. Finally, we also reviewed the major challenges and opportunities of nanomedicine‒biological environment interactions. We hope this review will provide insights into the pathogenesis and molecular mechanisms of liver cirrhosis, thus facilitating new methods, drug discovery, and better treatment of liver cirrhosis.

Liver fibrosis pathologies and potentials of RNA based therapeutics modalities

Liver fibrosis (LF) occurs when the liver tissue responds to injury or inflammation by producing excessive amounts of scar tissue, known as the extracellular matrix. This buildup stiffens the liver tissue, hinders blood flow, and ultimately impairs liver function. Various factors can trigger this process, including bloodborne pathogens, genetic predisposition, alcohol abuse, non-steroidal anti-inflammatory drugs, non-alcoholic steatohepatitis, and non-alcoholic fatty liver disease. While some existing small-molecule therapies offer limited benefits, there is a pressing need for more effective treatments that can truly cure LF. RNA therapeutics have emerged as a promising approach, as they can potentially downregulate cytokine levels in cells responsible for liver fibrosis. Researchers are actively exploring various RNA-based therapeutics, such as mRNA, siRNA, miRNA, lncRNA, and oligonucleotides, to assess their efficacy in animal models. Furthermore, targeted drug delivery systems hold immense potential in this field. By utilizing lipid nanoparticles, exosomes, nanocomplexes, micelles, and polymeric nanoparticles, researchers aim to deliver therapeutic agents directly to specific biomarkers or cytokines within the fibrotic liver, increasing their effectiveness and reducing side effects. In conclusion, this review highlights the complex nature of liver fibrosis, its underlying causes, and the promising potential of RNA-based therapeutics and targeted delivery systems. Continued research in these areas could lead to the development of more effective and personalized treatment options for LF patients.

Development of a Lipid-encapsulated TGFβRI-siRNA Drug for Liver Fibrosis Induced by Schistosoma mansoni

Schistosoma mansoni infection leads to chronic schistosomiasis and severe hepatic fibrosis. We designed a liver-targeted lipid nanoparticle (LNP) carrying siRNA against type I TGF-β receptor (TGFβRI) mRNA to treat schistosomiasis-induced liver fibrosis in BALB/c mice. Knockdown of TGFβRI by LNP-siTGFβRI reduced LX-2 cell activation in vitro and alleviated liver fibrosis in S. mansoni-infected mice. αSMA and Col1a1 fibrotic markers in the liver tissues of infected mice were significantly suppressed in the treatment groups. In the serum of the LNP-siTGFβRI-treated groups, cytokines IFNγ, IL-1α, IL-6, IL-12, RANTES (CCL5), and TNFα increased, while GM-CSF, IL-2, IL-4, IL-10, IL-13, and KC (CXCL1) decreased compared to the control. Cell proportions were significantly altered in S. mansoni-infected mice, with increased CD56d NK cells and decreased CD19+ B cells and CD4+ T cells compared to naïve mice. Following LNP-siTGFβRI treatment, CD56d NK cells were downregulated, while B and memory Th cell populations were upregulated. The density of fibrotic regions significantly decreased with LNP-siTGFβRI treatment in a dose-dependent manner, and no systemic toxicity was observed in the major organs. This targeted siRNA delivery strategy effectively reduced granulomatous lesions in schistosomiasis-induced liver fibrosis without detectable side effects.

Co-delivery of camptothecin and MiR-145 by lipid nanoparticles for MRI-visible targeted therapy of hepatocellular carcinoma

BACKGROUND

Camptothecin (CPT) is one of the frequently used small chemotherapy drugs for treating hepatocellular carcinoma (HCC), but its clinical application is limited due to severe toxicities and acquired resistance. Combined chemo-gene therapy has been reported to be an effective strategy for counteracting drug resistance while sensitizing cancer cells to cytotoxic agents. Thus, we hypothesized that combining CPT with miR-145 could synergistically suppress tumor proliferation and enhance anti-tumor activity.

METHODS

Lactobionic acid (LA) modified lipid nanoparticles (LNPs) were developed to co-deliver CPT and miR-145 into asialoglycoprotein receptors-expressing HCC in vitro and in vivo. We evaluated the synergetic antitumor effect of miR-145 and CPT using CCK8, Western blotting, apoptosis and wound scratch assay in vitro, and the mechanisms underlying the synergetic antitumor effects were further investigated. Tumor inhibitory efficacy, safety evaluation and MRI-visible ability were assessed using diethylnitrosamine (DEN) + CCl4-induced HCC mouse model.

RESULTS

The LA modification improved the targeting delivery of cargos to HCC cells and tissues. The LA-CMGL-mediated co-delivery of miR-145 and CPT is more effective on tumor inhibitory than LA-CPT-L or LA-miR-145-L treatment alone, both in vitro and in vivo, with almost no side effects during the treatment period. Mechanistically, miR-145 likely induces apoptosis by targeting SUMO-specific peptidase 1 (SENP1)-mediated hexokinase (HK2) SUMOylation and glycolysis pathways and, in turn, sensitizing the cancer cells to CPT. In vitro and in vivo tests confirmed that the loaded Gd-DOTA served as an effective T1-weighted contrast agent for noninvasive tumor detection as well as real-time monitoring of drug delivery and biodistribution.

CONCLUSIONS

The LA-CMGL-mediated co-delivery of miR-145 and CPT displays a synergistic therapy against HCC. The novel MRI-visible, actively targeted chemo-gene co-delivery system for HCC therapy provides a scientific basis and a useful idea for the development of HCC treatment strategies in the future.

Targeting Liver Epsins Ameliorates Dyslipidemia in Atherosclerosis

Rationale

Low density cholesterol receptor (LDLR) in the liver is critical for the clearance of low-density lipoprotein cholesterol (LDL-C) in the blood. In atherogenic conditions, proprotein convertase subtilisin/kexin 9 (PCSK9) secreted by the liver, in a nonenzymatic fashion, binds to LDLR on the surface of hepatocytes, preventing its recycling and enhancing its degradation in lysosomes, resulting in reduced LDL-C clearance. Our recent studies demonstrate that epsins, a family of ubiquitin-binding endocytic adaptors, are critical regulators of atherogenicity. Given the fundamental contribution of circulating LDL-C to atherosclerosis, we hypothesize that liver epsins promote atherosclerosis by controlling LDLR endocytosis and degradation.

Objective

We will determine the role of liver epsins in promoting PCSK9-mediated LDLR degradation and hindering LDL-C clearance to propel atherosclerosis.

Methods and Results

We generated double knockout mice in which both paralogs of epsins, namely, epsin-1 and epsin-2, are specifically deleted in the liver (Liver-DKO) on an ApoE -/- background. We discovered that western diet (WD)-induced atherogenesis was greatly inhibited, along with diminished blood cholesterol and triglyceride levels. Mechanistically, using scRNA-seq analysis on cells isolated from the livers of ApoE-/- and ApoE-/- /Liver-DKO mice on WD, we found lipogenic Alb hi hepatocytes to glycogenic HNF4α hi hepatocytes transition in ApoE-/- /Liver-DKO. Subsequently, gene ontology analysis of hepatocyte-derived data revealed elevated pathways involved in LDL particle clearance and very-low-density lipoprotein (VLDL) particle clearance under WD treatment in ApoE-/- /Liver-DKO, which was coupled with diminished plasma LDL-C levels. Further analysis using the MEBOCOST algorithm revealed enhanced communication score between LDLR and cholesterol, suggesting elevated LDL-C clearance in the ApoE-/- Liver-DKO mice. In addition, we showed that loss of epsins in the liver upregulates of LDLR protein level. We further showed that epsins bind LDLR via the ubiquitin-interacting motif (UIM), and PCSK9-triggered LDLR degradation was abolished by depletion of epsins, preventing atheroma progression. Finally, our therapeutic strategy, which involved targeting liver epsins with nanoparticle-encapsulated siRNAs, was highly efficacious at inhibiting dyslipidemia and impeding atherosclerosis.

Conclusions

Liver epsins promote atherogenesis by mediating PCSK9-triggered degradation of LDLR, thus raising the circulating LDL-C levels. Targeting epsins in the liver may serve as a novel therapeutic strategy to treat atherosclerosis by suppression of PCSK9-mediated LDLR degradation.

RNA nanomedicine in liver diseases

The remarkable impact of RNA nanomedicine during the COVID-19 pandemic has demonstrated the expansive therapeutic potential of this field in diverse disease contexts. In recent years, RNA nanomedicine targeting the liver has been paradigm-shifting in the management of metabolic diseases such as hyperoxaluria and amyloidosis. RNA nanomedicine has significant potential in the management of liver diseases, where optimal management would benefit from targeted delivery, doses titrated to liver metabolism, and personalized therapy based on the specific site of interest. In this review, we discuss in-depth the different types of RNA and nanocarriers used for liver targeting along with their specific applications in metabolic dysfunction-associated steatotic liver disease, liver fibrosis, and liver cancers. We further highlight the strategies for cell-specific delivery and future perspectives in this field of research with the emergence of small activating RNA, circular RNA, and RNA base editing approaches.

Nano-drug delivery systems (NDDS) in metabolic dysfunction-associated steatotic liver disease (MASLD): current status, prospects and challenges

About one-third of the global population suffers from metabolic dysfunction-associated steatotic liver disease (MASLD), but specific treatments for MASLD have long been lacking, primarily due to the unclear etiology of the disease. In addition to lifestyle modifications and weight loss surgery, pharmacotherapy is the most common treatment among MASLD patients, and these drugs typically target the pathogenic factors of MASLD. However, bioavailability, efficacy, and side effects all limit the maximum therapeutic potential of the drugs. With the development of nanomedicine, recent years have seen attempts to combine MASLD pharmacotherapy with nanomaterials, such as liposomes, polymer nanoparticles, micelles, and cocrystals, which effectively improves the water solubility and targeting of the drugs, thereby enhancing therapeutic efficacy and reducing toxic side effects, offering new perspectives and futures for the treatment of MASLD.

All Roads Lead to Rome: Comparing Nanoparticle- and Small Molecule-Driven Cell Autophagy

Autophagy, vital for removing cellular waste, is triggered differently by small molecules and nanoparticles. Small molecules, like rapamycin, non-selectively activate autophagy by inhibiting the mTOR pathway, which is essential for cell regulation. This can clear damaged components but may cause cytotoxicity with prolonged use. Nanoparticles, however, induce autophagy, often causing oxidative stress, through broader cellular interactions and can lead to a targeted form known as "xenophagy." Their impact varies with their properties but can be harnessed therapeutically. In this review, the autophagy induced by nanoparticles is explored and small molecules across four dimensions: the mechanisms behind autophagy induction, the outcomes of such induction, the toxicological effects on cellular autophagy, and the therapeutic potential of employing autophagy triggered by nanoparticles or small molecules. Although small molecules and nanoparticles each induce autophagy through different pathways and lead to diverse effects, both represent invaluable tools in cell biology, nanomedicine, and drug discovery, offering unique insights and therapeutic opportunities.

Targeting chronic liver diseases: Molecular markers, drug delivery strategies and future perspectives

Chronic liver inflammation, a pervasive global health issue, results in millions of annual deaths due to its progression from fibrosis to the more severe forms of cirrhosis and hepatocellular carcinoma (HCC). This insidious condition stems from diverse factors such as obesity, genetic conditions, alcohol abuse, viral infections, autoimmune diseases, and toxic accumulation, manifesting as chronic liver diseases (CLDs) such as metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction-associated steatohepatitis (MASH), alcoholic liver disease (ALD), viral hepatitis, drug-induced liver injury, and autoimmune hepatitis. Late detection of CLDs necessitates effective treatments to inhibit and potentially reverse disease progression. However, current therapies exhibit limitations in consistency and safety. A potential breakthrough lies in nanoparticle-based drug delivery strategies, offering targeted delivery to specific liver cell types, such as hepatocytes, Kupffer cells, and hepatic stellate cells. This review explores molecular targets for CLD treatment, ongoing clinical trials, recent advances in nanoparticle-based drug delivery, and the future outlook of this research field. Early intervention is crucial for chronic liver disease. Having a comprehensive understanding of current treatments, molecular biomarkers and novel nanoparticle-based drug delivery strategies can have enormous impact in guiding future strategies for the prevention and treatment of CLDs.

Lipid nanoparticles as the drug carrier for targeted therapy of hepatic disorders

The liver, a complex and vital organ in the human body, is susceptible to various diseases, including metabolic disorders, acute hepatitis, cirrhosis, and hepatocellular carcinoma. In recent decades, these diseases have significantly contributed to global morbidity and mortality. Currently, liver transplantation remains the most effective treatment for hepatic disorders. Nucleic acid therapeutics offer a selective approach to disease treatment through diverse mechanisms, enabling the regulation of relevant genes and providing a novel therapeutic avenue for hepatic disorders. It is expected that nucleic acid drugs will emerge as the third generation of pharmaceuticals, succeeding small molecule drugs and antibody drugs. Lipid nanoparticles (LNPs) represent a crucial technology in the field of drug delivery and constitute a significant advancement in gene therapies. Nucleic acids encapsulated in LNPs are shielded from the degradation of enzymes and effectively delivered to cells, where they are released and regulate specific genes. This paper provides a comprehensive review of the structure, composition, and applications of LNPs in the treatment of hepatic disorders and offers insights into prospects and challenges in the future development of LNPs.

Peptide-conjugated Nanoparticle Platforms for Targeted Delivery, Imaging, and Biosensing Applications

Peptides have become an indispensable tool in engineering of multifunctional nanostructure platforms for biomedical applications such as targeted drug and gene delivery, imaging and biosensing. They can be covalently incorporated into a variety of nanoparticles (NPs) including polymers, metallic nanoparticles, and others. Using different bioconjugation techniques, multifunctional peptide-modified NPs can be formulated to produce therapeutical and diagnostic platforms offering high specificity, lower toxicity, biocompatibility, and stimuli responsive behavior. Targeting peptides can direct the nanoparticles into specific tissues for targeted drug and gene delivery and imaging applications due to their specificity towards certain receptors. Furthermore, due to their stimuli-responsive features, they can offer controlled release of therapeutics into desired sites of disease. In addition, peptide-based biosensors and imaging agents can provide non-invasive detection and monitoring of diseases including cancer, infectious diseases, and neurological disorders. In this review, we covered the design and formulation of recent peptide-based NP platforms, as well as their utilization in in vitro and in vivo applications such as targeted drug and gene delivery, targeting, sensing, and imaging applications. In the end, we provided the future outlook to design new peptide conjugated nanomaterials for biomedical applications.

Hepatic Stellate Cell-Targeting Micelle Nanomedicine for Early Diagnosis and Treatment of Liver Fibrosis

Diagnosing and treating liver fibrosis is a challenging yet crucial endeavor due to its complex pathogenesis and risk of deteriorating into cirrhosis, liver failure, and even hepatic cancer. Herein, a silica cross-linked micelles (SCLMs) based nano-system is developed for both diagnosing and treating liver fibrosis. The SCLMs are first modified with peptide CTCE9908 (CT-SCLMs) and can actively target CXCR4, which is overexpressed in activated hepatic stellate cells (HSCs). To enable diagnosis, an ONOO--responded near-infrared fluorescent probe NOF2 is loaded into the CT-SCLMs. This nano-system can target the aHSCs and diagnose the liver fibrosis particularly in CCl4-induced liver damage, by monitoring the reactive nitrogen species. Furthermore, a step is taken toward treatment by co-encapsulating two anti-fibrosis drugs, silibinin and sorafenib, within the CT-SCLMs. This combined approach results in a significant alleviation of liver injury. Symptoms associated with liver fibrosis, such as deposition of collagen, expression of hydroxyproline, and raised serological indicators show notable improvement. In summary, the CXCR4-targeted nano-system can serve as a promising theragnostic system of early warning and diagnosis for liver fibrosis, offering hope against progression of this serious liver condition.

Cholesterol-Modified Anti-Il6 siRNA Reduces the Severity of Acute Lung Injury in Mice

Small interfering RNA (siRNA) holds significant therapeutic potential by silencing target genes through RNA interference. Current clinical applications of siRNA have been primarily limited to liver diseases, while achievements in delivery methods are expanding their applications to various organs, including the lungs. Cholesterol-conjugated siRNA emerges as a promising delivery approach due to its low toxicity and high efficiency. This study focuses on developing a cholesterol-conjugated anti-Il6 siRNA and the evaluation of its potency for the potential treatment of inflammatory diseases using the example of acute lung injury (ALI). The biological activities of different Il6-targeted siRNAs containing chemical modifications were evaluated in J774 cells in vitro. The lead cholesterol-conjugated anti-Il6 siRNA after intranasal instillation demonstrated dose-dependent therapeutic effects in a mouse model of ALI induced by lipopolysaccharide (LPS). The treatment significantly reduced Il6 mRNA levels, inflammatory cell infiltration, and the severity of lung inflammation. IL6 silencing by cholesterol-conjugated siRNA proves to be a promising strategy for treating inflammatory diseases, with potential applications beyond the lungs.

Alginate microspheres encapsulating hox transcript antisense RNA siRNA regulate the Hedgehog-Gli1 pathway to alleviate epidermal growth factor receptor tyrosine kinase inhibitors resistance

The long non-coding RNA HOTAIR and the Hedgehog-Gli1 signaling pathway are closely associated with tumor occurrence and drug resistance in various cancers. However, their specific roles in the development of EGFR-TKIs resistance in non-small cell carcinoma remain unclear. To address the issue of EGFR-TKIs resistance, this study utilized the electrospray method to prepare sodium alginate microspheres encapsulating HOTAIR siRNA (SA/HOTAIR siRNA) and investigated its effects on RNA interference (RNAi) in the gefitinib-resistant cell line PC9/GR. Furthermore, the study explored whether HOTAIR could modulate EGFR-TKIs resistance through the Hedgehog-GLi1 signaling pathway. The experimental results showed that sodium alginate (SA) microspheres demonstrated excellent biocompatibility with high encapsulation efficiency and drug-loading capacity, effectively enhancing the silencing efficiency of siRNA. HOTAIR siRNA significantly inhibited the proliferation, migration, and invasion abilities of PC9/GR cells while promoting apoptosis. Additionally, HOTAIR siRNA effectively suppressed tumor growth and downregulated the Hedgehog-GLi1 pathway and anti-apoptotic proteins, which were confirmed in animal experiments. Moreover, SA/HOTAIR siRNA exhibited superior inhibition of cellular and tumor functions compared to using HOTAIR siRNA alone. Clinical research findings indicated that monitoring the expression level of HOTAIR in the serum and urine samples of NSCLC patients before and after receiving EGFR-TKIs treatment can predict the efficacy of EGFR-TKIs to a certain extent. This study provided evidence that HOTAIR siRNA effectively mitigated the development of acquired resistance to EGFR-TKIs by inhibiting the Hedgehog-GLi1 pathway. Furthermore, it introduced a reliable and long-lasting drug delivery system for combating acquired resistance to EGFR-TKIs.

Liver fibrosis: pathological features, clinical treatment and application of therapeutic nanoagents

Liver fibrosis is a reversible damage-repair response, the pathological features of which mainly include damage to hepatocytes, sinusoid capillarization, hepatic stellate cells activation, excessive accumulation of extracellular matrix and inflammatory response. Although some treatments (including drugs and stem cell therapy) for these pathological features have been shown to be effective, more clinical trials are needed to confirm their effectiveness. In recent years, nanomaterials-based therapies have emerged as an innovative and promising alternative to traditional drugs, being explored for the treatment of liver fibrosis diseases. Natural nanomaterials (including extracellular vesicles) and synthetic nanomaterials (including inorganic nanomaterials and organic nanomaterials) are developed to facilitate drug targeting delivery and combination therapy. In this review, the pathological features of liver fibrosis and the current anti-fibrosis drugs in clinical trials are briefly introduced, followed by a detailed introduction of the therapeutic nanoagents for the precise delivery of anti-fibrosis drugs. Finally, the future development trend in this field is discussed.

Surface modification of lipid nanoparticles for gene therapy

Gene therapies have the potential to target and effectively treat a variety of diseases including cancer as well as genetic, neurological, and autoimmune disorders. Although we have made significant advances in identifying non-viral strategies to deliver genetic cargo, certain limitations remain. In general, gene delivery is challenging for several reasons including the instabilities of nucleic acids to enzymatic and chemical degradation and the presence of restrictive biological barriers such as cell, endosomal and nuclear membranes. The emergence of lipid nanoparticles (LNPs) helped overcome many of these challenges. Despite its success, further optimization is required for LNPs to yield efficient gene delivery to extrahepatic tissues, as LNPs favor accumulation in the liver after systemic administration. In this mini-review, we provide an overview of current preclinical approaches in that LNP surface modification was leveraged for cell and tissue targeting by conjugating aptamers, antibodies, and peptides among others. In addition to their cell uptake and efficiency-enhancing effects, we outline the (dis-)advantages of the different targeting moieties and commonly used conjugation strategies.

Lipid Nanoparticles Optimized for Targeting and Release of Nucleic Acid

Lipid nanoparticles (LNPs) are currently the most promising clinical nucleic acids drug delivery vehicles. LNPs prevent the degradation of cargo nucleic acids during blood circulation. Upon entry into the cell, specific components of the lipid nanoparticles can promote the endosomal escape of nucleic acids. These are the basic properties of lipid nanoparticles as nucleic acid carriers. As LNPs exhibit hepatic aggregation characteristics, enhancing targeting out of the liver is a crucial way to improve LNPs administrated in vivo. Meanwhile, endosomal escape of nucleic acids loaded in LNPs is often considered inadequate, and therefore, much effort is devoted to enhancing the intracellular release efficiency of nucleic acids. Here, different strategies to efficiently deliver nucleic acid delivery from LNPs are concluded and their mechanisms are investigated. In addition, based on the information on LNPs that are in clinical trials or have completed clinical trials, the issues that are necessary to be approached in the clinical translation of LNPs are discussed, which it is hoped will shed light on the development of LNP nucleic acid drugs.

Emerging drug delivery systems with traditional routes - A roadmap to chronic inflammatory diseases

Inflammation is prevalent and inevitable in daily life but can generally be accommodated by the immune systems. However, incapable self-healing and persistent inflammation can progress to chronic inflammation, leading to prevalent or fatal chronic diseases. This review comprehensively covers the topic of emerging drug delivery systems (DDSs) for the treatment of chronic inflammatory diseases (CIDs). First, we introduce the basic biology of the chronic inflammatory process and provide an overview of the main CIDs of the major organs. Next, up-to-date information on various DDSs and the associated strategies for ensuring targeted delivery and stimuli-responsiveness applied to CIDs are discussed extensively. The implementation of traditional routes of drug administration to maximize their therapeutic effects against CIDs is then summarized. Finally, perspectives on future DDSs against CIDs are presented.

Co-delivery of pirfenidone and siRNA in ZIF-based nanoparticles for dual inhibition of hepatic stellate cell activation in liver fibrotic therapy

Hepatic fibrosis, as a destructive liver disease, occurs due to activated hepatic stellate cells (HSCs) producing excessive extracellular matrix deposition. If left untreated, it could further deteriorate into cirrhosis and hepatoma with high morbidity and mortality. Currently, to break the dilemma of poor targeting efficiency on HSCs and limited effect of monotherapy, it is urgent to explore a precise and efficient treatment against liver fibrosis. In the present work, a novel multifunctional nanoplatform based on vitamin A (VA) modified zeolitic imidazolate framework-8 (ZIF-8) nanoparticles was designed for co-delivery of chemical drug (Pirfenidone) and genetic drug (TGF-β1 siRNA) to achieve HSCs targeting mediated synergistic chemo-gene therapy against liver fibrosis. With the large specific surface area and acid-responsive degradation characteristics, ZIF-8 nanoparticles have great advantages to achieve high loading efficiency of Pirfenidone and enable acid-reactive drug release. After complexing siRNA, the prepared chemo-gene drug co-delivered nanocomplex (GP@ZIF-VL) proved excellent serum stability and effectively protected siRNA from degradation. Importantly, in vitro cell uptake and in vivo biodistribution demonstrated that VA functionalization markedly enhanced the delivery efficiency of GP@ZIF-VL nanocomplex into HSCs. As expected, GP@ZIF-VL significantly reduced extracellular matrix deposition and ameliorated hepatic fibrosis, as evidenced by decreased levels of liver enzymes in serum and a reduction in the hydroxyproline content in liver tissue. Therefore, GP@ZIF-VL nanocomplex displayed a bright future on the treatment of liver fibrosis with HSCs-targeting mediated chemo-gene synergetic therapy.

Prospective therapeutics for intestinal and hepatic fibrosis

Currently, there are no effective therapies for intestinal and hepatic fibrosis representing a considerable unmet need. Breakthroughs in pathogenesis have accelerated the development of anti-fibrotic therapeutics in recent years. Particularly, with the development of nanotechnology, the harsh environment of the gastrointestinal tract and inaccessible microenvironment of fibrotic lesions seem to be no longer considered a great barrier to the use of anti-fibrotic drugs. In this review, we comprehensively summarize recent preclinical and clinical studies on intestinal and hepatic fibrosis. It is found that the targets for preclinical studies on intestinal fibrosis is varied, which could be divided into molecular, cellular, and tissues level, although little clinical trials are ongoing. Liver fibrosis clinical trials have focused on improving metabolic disorders, preventing the activation and proliferation of hepatic stellate cells, promoting the degradation of collagen, and reducing inflammation and cell death. At the preclinical stage, the therapeutic strategies have focused on drug targets and delivery systems. At last, promising remedies to the current challenges are based on multi-modal synergistic and targeted delivery therapies through mesenchymal stem cells, nanotechnology, and gut-liver axis providing useful insights into anti-fibrotic strategies for clinical use.

Surface engineering of lipid nanoparticles: targeted nucleic acid delivery and beyond

Harnessing surface engineering strategies to functionalize nucleic acid-lipid nanoparticles (LNPs) for improved performance has been a hot research topic since the approval of the first siRNA drug, patisiran, and two mRNA-based COVID-19 vaccines, BNT162b2 and mRNA-1273. Currently, efforts have been mainly made to construct targeted LNPs for organ- or cell-type-specific delivery of nucleic acid drugs by conjugation with various types of ligands. In this review, we describe the surface engineering strategies for nucleic acid-LNPs, considering ligand types, conjugation chemistries, and incorporation methods. We then outline the general purification and characterization techniques that are frequently used following the engineering step and emphasize the specific techniques for certain types of ligands. Next, we comprehensively summarize the currently accessible organs and cell types, as well as the other applications of the engineered LNPs. Finally, we provide considerations for formulating targeted LNPs and discuss the challenges of successfully translating the "proof of concept" from the laboratory into the clinic. We believe that addressing these challenges could accelerate the development of surface-engineered LNPs for targeted nucleic acid delivery and beyond.

Reprogramming activated hepatic stellate cells by siRNA-loaded nanocarriers reverses liver fibrosis in mice

We report on a novel strategy for treating liver fibrosis through reprogramming activated Hepatic Stellate Cells (aHSCs) into quiescent Hepatic Stellate Cells (qHSCs) using siRNA-loaded lipid nanoparticles (LNPs). The in vivo screening of an array of molecularly-diverse ionizable lipids identified two candidates, CL15A6 and CL15H6, with a high siRNA delivery efficiency to aHSCs. Optimization of the composition and physico-chemical properties of the LNPs enabled the ligand-free, selective, and potent siRNA delivery to aHSCs post intravenous administration, with a median effective siRNA dose (ED50) as low as 0.08 mg/Kg. The biosafety of the LNPs was confirmed by escalating the dose to 50-fold higher than the ED50 or by chronic administration. The recruitment of the novel LNPs for the simultaneous knockdown of Hedgehog (Hh) and Transforming Growth Factor Beta 1 (TGFβ1) signaling pathways using an siRNA cocktail enabled the reversal of liver fibrosis and the restoration of the normal liver function in mice. Analysis of the key transcription factors in aHSCs suggested that the reprogramming of aHSCs into qHSCs mediated the therapeutic outcomes. The scalable ligand-free platform developed in this study as well as the novel therapeutic strategy reported herein are promising for clinical translation.

Nanoparticle-Mediated RNA Therapy Attenuates Nonalcoholic Steatohepatitis and Related Fibrosis by Targeting Activated Hepatic Stellate Cells

Chronic liver injury and inflammation triggered by metabolic abnormalities initiate the activation of hepatic stellate cells (HSCs), driving fibrosis and parenchymal dysfunction, culminating in disorders such as nonalcoholic steatohepatitis (NASH). Unfortunately, there are currently no approved drugs capable of effectively treating NASH due to the challenges in addressing fibrosis and restoring extracellular matrix (ECM) homeostasis. We discovered a significant up-regulation of interleukin-11 (IL-11) in fibrotic livers using two well-established murine models of NASH. To leverage this signaling pathway, we developed a nanoparticle (NP)-assisted RNA interfering approach that specifically targets activated HSCs (aHSCs), blocking IL-11/ERK signaling to regulate HSC transdifferentiation along with fibrotic remodeling. The most potent NP, designated NP-AEAA, showed enhanced accumulation in fibrotic livers with NASH and was primarily enriched in aHSCs. We further investigated the therapeutic efficacy of aHSC-targeting NP-AEAA encapsulating small interfering RNA (siRNA) against IL11 or its cognate receptor IL11ra1 (termed siIL11@NP-AEAA or siIL11ra1@NP-AEAA, respectively) for resolving fibrosis and NASH. Our results demonstrate that both siIL11@NP-AEAA and siIL11ra1@NP-AEAA effectively inhibit HSC activation and resolve fibrosis and inflammation in two well-established murine models of NASH. Notably, siIL11ra1@NP-AEAA exhibits a superior therapeutic effect over siIL11@NP-AEAA, in terms of reducing liver steatosis and fibrosis as well as recovering liver function. These results constitute a targeted nanoparticulate siRNA therapeutic approach against the IL-11 signaling pathway of aHSCs in the fibrotic liver, offering a promising therapeutic intervention for NASH and other diseases.

Retinol-binding protein-hijacking nanopolyplex delivering siRNA to cytoplasm of hepatic stellate cell for liver fibrosis alleviation

Activated hepatic stellate cell (aHSC) is mainly responsible for deposition of extracellular collagen matrix that causes liver fibrosis. Although several siRNAs adequately inhibited HSC activation in vitro, they were demonstrated poor RNAi efficiency in vivo. Developing HSC-targeting and cytoplasmic delivery nanocarrier is highly essential to acquire a desirable siRNA therapeutic index for anti-liver fibrosis. Here, we developed a unique crosslinking nanopolyplex (called T-C-siRNA) modified by vitamin A (VA) with the well-designed natures, including the negative charge, retinol-binding protein (RBP) hijacking, and cytoplasmic siRNA release in response to ROS and cis diol molecules. The nanopolyplex was given a yolk-shell-like shape, camouflage ability in blood, and HSC-targeting capability by hijacking the endogenous ligand RBP via surface VA. PDGFR-β siRNA (siPDGFR-β) supplied via T-C-siPDGFR-β nanopolyplex dramatically reduced HSC activation and its production of pro-fibrogenic proteins in vitro and in vivo. Furthermore, T-C-siPDGFR-β nanopolyplex effectively alleviated CCl4-induced liver injury, decreased hepatic collagen sediment, and recovered liver function in mice. This study provides a sophisticated method for HSC-targeting cytoplasmic RNA delivery using endogenous ligand hijacking and dual sensitivity of ROS and cis diol compounds.

Reversal of hepatic fibrosis by the co-delivery of drug and ribonucleoprotein-based genome editor

Liver fibrosis is a chronic disease without effective treatment in the clinic. Gene editing systems such as the well-known CRISPR/Cas9 have shown great potential in the biomedical field. However, the delivery of the ribonucleoprotein is challenging due to the unstable RNA probe and the requirement for the entrance to the nucleus. Recently, a structure-guided endonuclease (SGN) has been reported as an effective gene-editing system composed of a nuclease and stable DNA probes, which can regulate the protein expression by targeting specific mRNA outside the nucleus. Here, we conjugated the SGN to a nanomicelle as the delivery system. In the resulting material, the chance of the collision between the endonuclease and the probe was raised due to the confinement of the two components within the 40-nm nanomicelle, thus the mRNA can be cleaved immediately after being captured by the probe, resulting in a space-induced nucleotide identification-cleavage acceleration effect. The delivery system was used to treat liver fibrosis via the co-delivery of SGN and a drug rosiglitazone to the hepatic stellate cells, which separately downregulated the expression of tissue inhibitor of metalloprotease-1 and inactivated the hepatic stellate cells. The system successfully reversed the liver fibrosis in mice through the bidirectional regulatory that simultaneously promoted the degradation and inhibited the production of the collagen, demonstrating the great potency of the SGN system as gene medicine.

Remodeling liver microenvironment by L-arginine loaded hollow polydopamine nanoparticles for liver cirrhosis treatment

Liver cirrhosis is a liver disease with a high mortality rate worldwide, and antifibrotic drugs are commonly used clinically to alleviate the symptoms, but there are still many challenges. Many studies have shown that excessive reactive oxygen species (ROS) in the microenvironment of liver lesions is an important factor leading to the development of liver cirrhosis. Herein, a nanomedicine-mediated antioxidant therapy was utilized to remodel liver microenvironment and hence reverse the process of cirrhosis from the root. Firstly, L-arginine (L-Arg) loaded and pPB peptide modified PEGylated hollow polydopamine (HPDA) nanoparticles (L-Arg@HPDA-PEG-pPB, L@HPp) were prepared successfully. The in vitro and in vivo experiment showed that L@HPp significantly inhibited oxidative stress and inflammatory reaction, reduced the activation of hepatic stellate cells (HSCs), inhibited the pro-fibrosis molecular pathway, and reduced the deposition of extracellular matrix (ECM), thereby effectively inhibiting liver fibrosis. The pPB peptide modification increased the targeting effect to HSCs. In addition, the oxidative microenvironment in liver cirrhosis promoted the transformation of the loaded L-Arg to nitric oxide (NO), and the latter one caused vascular dilation and further relieved portal hypertension, a typical complication of liver cirrhosis. Therefore, L@HPp had a good prospect of clinical application in the treatment of liver cirrhosis and its complications.

Albumin-Based Silibinin Nanocrystals Targeting Activated Hepatic Stellate Cells for Liver Fibrosis Therapy

Activated hepatic stellate cells (aHSCs) are critical during the development and progression of liver fibrosis. Once liver fibrosis occurs, aHSCs highly express secreted protein, acidic and rich in cysteine (SPARC), a typical albumin-binding protein. We designed a nano platform, silibinin albumin nanocrystals (SLB-HSA NCs), to target aHSCs for liver fibrosis therapy. The prepared SLB-HSA NCs showed uniform particle size distribution of approximately 60 nm with PDI < 0.15 and high loading efficiency up to 49.4%. Albumin coated on the surface of nanocrystals was demonstrated to increase cellular uptake by aHSCs through SPARC-mediated endocytosis. In addition, SLB-HSA NCs significantly improved the bioavailability compared with free SLB in pharmacokinetic study. Following tail-vein injection, SLB-HSA NCs were massively accumulated in the fibrotic liver and exhibited enhanced antifibrotic effects in hepatic fibrosis mice. Overall, our findings prove the great potential of SLB-HSA NCs in the targeted treatment of liver fibrosis.

Protective effect of pinocembrin from Penthorum chinense Pursh on hepatic ischemia reperfusion injury via regulating HMGB1/TLR4 signal pathway

Hepatic ischemia-reperfusion injury (HIRI) is of common occurrence during liver surgery and transplantation. Pinocembrin (PIN) is a kind of flavonoid monomer extracted from the local traditional Chinese medicine Penthorum chinense Pursh (P. chinense). However, the effect of PIN on HIRI has not determined. We investigated the protective effect and potential mechanism of PIN against HIRI. Model mice were subjected to partial liver ischemia for 60 min, experimental mice were pretreated with PIN orally for 7 days, and H₂ O₂ -induced oxidative damage model in AML12 hepatic cells was established in vitro. Histopathologic analysis and serum biochemical levels revealed that PIN had hepatoprotective activities against HIRI. The variation of GSH, SOD, MDA, and ROS levels indicated that PIN treatments attenuated oxidative stress in tissue. PIN pretreatment obviously ameliorated apoptosis, and restrained the expression of HMGB1 and TLR4 in vivo. In vitro, compared with H₂ O₂ group, the contents of ROS, mitochondrial membrane potential, apoptotic cells, and Bcl-2 protein were decreased, while the Bax protein expression was increased. Moreover, HMGB-1 small interfering RNA test and western blotting showed that PIN pretreatment reduced HMGB1 and TLR4 protein levels. In conclusion, PIN pretreatment effectively protected hepatocytes from HIRI and inhibited the HMGB1/TLR4 signaling pathway.

Monitoring the in vivo siRNA release from lipid nanoparticles based on the fluorescence resonance energy transfer principle

The siRNA-loaded lipid nanoparticles have attracted much attention due to its significant gene silencing effect and successful marketization. However, the in vivo distribution and release of siRNA still cannot be effectively monitored. In this study, based on the fluorescence resonance energy transfer (FRET) principle, a fluorescence dye Cy5-modified survivin siRNA was conjugated to nanogolds (Au-DR-siRNA), which were then wrapped with lipid nanoparticles (LNPs) for monitoring the release behaviour of siRNA in vivo. The results showed that once Au-DR-siRNA was released from the LNPs and cleaved by the Dicer enzyme to produce free siRNA in cells, the fluorescence of Cy5 would change from quenched state to activated state, showing the location and time of siRNA release. Besides, the LNPs showed a significant antitumor effect by silencing the survivin gene and a CT imaging function superior to iohexol by nanogolds. Therefore, this work provided not only an effective method for monitoring the pharmacokinetic behaviour of LNP-based siRNA, but also a siRNA delivery system for treating and diagnosing tumors.

Self-homing nanocarriers for mRNA delivery to the activated hepatic stellate cells in liver fibrosis

Herein, we report on the development of a platform for the selective delivery of mRNA to the hard-to-transfect Activated Hepatic Stellate Cells (aHSCs), the fundamental player in the progression of liver fibrosis. Using a microfluidic device (iLiNP), we prepared a series of lipid nanoparticles (LNPs) based on a diverse library of pH-sensitive lipids. After an in-depth in vivo optimization of the LNPs, their mRNA delivery efficiency, selectivity, potency, robustness, and biosafety were confirmed. Furthermore, some mechanistic aspects of their selective delivery to aHSCs were investigated. We identified a promising lipid candidate, CL15A6, that has a high affinity to aHSCs. Tweaking the composition and physico-chemical properties of the LNPs enabled the robust and ligand-free mRNA delivery to aHSCs in vivo post intravenous administration, with a high biosafety at mRNA doses of up to 2 mg/Kg, upon either acute or chronic administrations. The mechanistic investigation suggested that CL15A6 LNPs were taken up by aHSCs via Clathrin-mediated endocytosis through the Platelet-derived growth factor receptor beta (PDGFRβ) and showed a pKa-dependent cellular uptake. The novel and scalable platform reported in this study is highly promising for clinical applications.

Recent Advancements in the Design of Nanodelivery Systems of siRNA for Cancer Therapy

RNA interference (RNAi) has increased the possibility of restoring RNA drug targets for cancer treatment. Small interfering RNA (siRNA) is a promising therapeutic RNAi tool that targets the defective gene by inhibiting its mRNA expression and stopping its translation. However, siRNAs have flaws like poor intracellular trafficking, RNase degradation, rapid kidney filtration, off-targeting, and toxicity, which limit their therapeutic efficiency. Nanocarriers (NCs) have been designed to overcome such flaws and increase antitumor activity. Combining siRNA and anticancer drugs can give synergistic effects in cancer cells, making them a significant gene-modification tool in cancer therapy. Our discussion of NCs-mediated siRNA delivery in this review includes their mechanism, limitations, and advantages in comparison with naked siRNA delivery. We will also discuss organic NCs (polymers and lipids) and inorganic NCs (quantum dots, carbon nanotubes, and gold) that have been reported for extensive delivery of therapeutic siRNA to tumor sites. Finally, we will conclude by discussing the studies based on organic and inorganic NCs-mediated siRNA drug delivery systems conducted in the years 2020 and 2021.

Airway epithelial cell-specific delivery of lipid nanoparticles loading siRNA for asthma treatment

With specific and inherent mRNA cleaving activity, small interfering RNA (siRNA) has been deemed promising therapeutics to reduce the exacerbation rate of asthma by inhibiting the expression and release of proinflammatory cytokines from airway epithelial cells (AECs). To exert the therapeutic effects of siRNA drugs, nano-formulations with high efficiency and safety are required to deliver these nucleic acids to the target cells. Herein, we exploited novel inhaled lipid nanoparticles (LNPs) targeting intercellular adhesion molecule-1 (ICAM-1) receptors on the apical side of AECs. This delivery system is meant to enhance the specific delivery efficiency of siRNA in AECs to prevent the expression of proinflammatory cytokines in AECs and the concomitant symptoms in parallel. A cyclic peptide that resembles part of the capsid protein of rhinovirus and binds to ICAM-1 receptors was initially conjugated with cholesterol and subsequently assembled with ionizable cationic lipids to form the LNPs (Pep-LNPs) loaded with siRNA against thymic stromal lymphopoietin (TSLP siRNA). The obtained Pep-LNPs were subjected to thorough characterization and evaluations in vitro and in vivo. Pep-LNPs significantly enhanced cellular uptake and gene silencing efficiency in human epithelial cells expressing ICAM-1 in vitro, exhibited AEC-specific delivery and improved the gene silencing effect in ovalbumin-challenged asthmatic mice after pulmonary administration. More importantly, Pep-LNPs remarkably downregulated the expression of TSLP in AECs, effectively alleviated inflammatory cell infiltration, and reduced the secretion of other proinflammatory cytokines, including IL-4 and IL-13, as well as mucus production in asthmatic mice. This study demonstrates that Pep-LNPs are safe and efficient to deliver siRNA drugs to asthmatic AECs and could potentially alleviate allergic asthma by inhibiting the overexpression of proinflammatory cytokines in the airway.

High Levels of Heat Shock Protein 47 in the Aqueous Humor of Patients with Acute Primary Angle Closure

INTRODUCTION

Acute primary angle closure (APAC) is often characterized by acute elevation of intraocular pressure accompanied by severe ocular and systemic symptoms. Excessive collagen accumulation, which can be caused by upregulated heat shock protein 47 (HSP47) expression, can produce scarring in rat conjunctival blebs. Meanwhile, the presence of HSP47 in human aqueous humor and its levels are yet to be determined.

METHODS

We examined 32 consecutive patients with APAC and 16 age-matched participants without APAC scheduled for cataract surgery who were enrolled as a control group. Aqueous humor samples were collected from all subjects at the time of surgery and compared between the subjects with and without APAC.

RESULTS

The levels of HSP47 in the aqueous humor of patients with APAC (1,210.4 ± 450.2 pg/mL) were found to be significantly increased (p = 0.001) compared with those in the control group (863.4 ± 240.0 pg/mL). Notably, the levels of HSP47 negatively correlated with the age of patients with APAC (p = 0.023).

CONCLUSION

HSP47 was upregulated in the aqueous humor of patients with APAC and may play a role in scarring after trabeculectomy for APAC.

Co-Delivery of Doxorubicin and Anti-PD-L1 Peptide in Lipid/PLGA Nanocomplexes for the Chemo-Immunotherapy of Cancer

The combined delivery of chemotherapeutics with checkpoint inhibitors of the PD-1/PD-L1 pathway provides a new approach for cancer treatment. Small-molecule peptide inhibitors possess short production cycle, low immunogenicity, and fewer side effects; however, their potential in cancer therapy is hampered by the rapid biodegradation and a nanocarrier is needed for efficient drug delivery. Herein, anticancer drug doxorubicin (DOX) and PD-L1 inhibitor peptide P-12 are co-loaded by a lipid polymer nanocomplex based on poly(lactic-co-glycolic acid) (PLGA) and DSPE-PEG. Octaarginine (R8)-conjugated DSPE-PEG renders the LPN efficient internalization by cancer cells. The optimal nanomedicine LPN-30-R8^2K@DP shows a diameter of 125 nm and a DOX and P-12 loading content of 5.0 and 6.2%, respectively. LPN-30-R8^2K@DP exhibits good physiological stability and enhanced cellular uptake by cancer cells. It successfully induces immunogenic cell death and PD-L1 blockade in CT26 cancer cells. The in vivo antitumor study further suggests that co-loaded nanomedicine efficiently suppresses CT26 tumor growth and elicits antitumor immune response. This study manifests that lipid polymer nanocomplexes are promising drug carriers for the efficient chemo-immunotherapy of cancer.

Antibody-drug conjugates targeting CD248 inhibits liver fibrosis through specific killing on myofibroblasts

Background

Chronic liver injury induces pathological repair, resulting in fibrosis, during which hepatic stellate cells (HSCs) are activated and transform into myofibroblasts. CD248 is mainly expressed on myofibroblasts and was considered as a promising target to treat fibrosis. The primary aim of this study was to generate a CD248 specific antibody-drug conjugate (ADC) and evaluate its therapeutic efficacy for liver fibrosis and its safety in vivo.

Methods

CD248 expression was examined in patients with liver cirrhosis and in mice with CCl₄-induced liver fibrosis. The ADC IgG78-DM1, which targets CD248, was prepared and its bioactivity on activated primary HSCs was studied. The anti-fibrotic effects of IgG78-DM1 on liver fibrosis were evaluated in CCl₄-induced mice. The reproductive safety and biosafety of IgG78-DM1 were also evaluated in vivo.

Results

CD248 expression was upregulated in patients with liver cirrhosis and in CCl₄-induced mice, and was mainly expressed on alpha smooth muscle actin (α-SMA)⁺ myofibroblasts. IgG78-DM1 was successfully generated, which could effectively bind with and kill CD248⁺ activated HSCs in vitro and inhibit liver fibrosis in vivo. In addition, IgG78-DM1 was demonstrated to have qualified biosafety and reproductive safety in vivo.

Conclusions

Our study demonstrated that CD248 could be an ideal target for myofibroblasts in liver fibrosis, and CD248-targeting IgG78-DM1 had excellent anti-fibrotic effects in mice with liver fibrosis. Our study provided a novel strategy to treat liver fibrosis and expanded the application of ADCs beyond tumors.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00460-1.

Synthetic Conjugated Oligoelectrolytes Are Effective siRNA Transfection Carriers: Relevance to Pancreatic Cancer Gene Therapy

Conjugated oligoelectrolyte COE-S6 contains an elongated conjugated core with three cationic charges at each termini of the internal core. As an analogue of bolaamphiphiles, these structural attributes lead to the formation of spherical nanoplexes with Dh = 205 ± 5.0 nm upon mixing with small interfering RNA (siRNA). COE-S6/siRNA nanocomplexes were shown to be protective toward RNase, stimulate endosome escape, and achieve transfection efficiencies comparable to those achieved with commercially available LIP3000. Moreover, COE-S6/siRNA nanocomplexes enabled efficient silencing of the K-ras gene in pancreatic cancer cells and significant inhibition of cancer tumor growth with negligible in vitro toxicities. More importantly, cell invasion and colony formation of the Panc-1 cells were significantly inhibited, and apoptosis of the pancreatic cancer cells was also promoted. We also note that COE-S6 is much less toxic relative to commercial lipid formulations, and it provides optical signatures that can enable subsequent mechanistic work without the need to label nucleotides. COE-S6-based nanoplexes are thus a promising candidate as nonviral vectors for gene delivery.

Nanotechnology in Drug Delivery for Liver Fibrosis

Liver fibrosis is a reversible disease course caused by various liver injury etiologies, and it can lead to severe complications, such as liver cirrhosis, liver failure, and even liver cancer. Traditional pharmacotherapy has several limitations, such as inadequate therapeutic effect and side effects. Nanotechnology in drug delivery for liver fibrosis has exhibited great potential. Nanomedicine improves the internalization and penetration, which facilitates targeted drug delivery, combination therapy, and theranostics. Here, we focus on new targets and new mechanisms in liver fibrosis, as well as recent designs and development work of nanotechnology in delivery systems for liver fibrosis treatment.

Non-viral vectors for RNA delivery

RNA-based therapy is a promising and potential strategy for disease treatment by introducing exogenous nucleic acids such as messenger RNA (mRNA), small interfering RNA (siRNA), microRNA (miRNA) or antisense oligonucleotides (ASO) to modulate gene expression in specific cells. It is exciting that mRNA encoding the spike protein of COVID-19 (coronavirus disease 2019) delivered by lipid nanoparticles (LNPs) exhibits the efficient protection of lungs infection against the virus. In this review, we introduce the biological barriers to RNA delivery in vivo and discuss recent advances in non-viral delivery systems, such as lipid-based nanoparticles, polymeric nanoparticles, N-acetylgalactosamine (GalNAc)-siRNA conjugate, and biomimetic nanovectors, which can protect RNAs against degradation by ribonucleases, accumulate in specific tissue, facilitate cell internalization, and allow for the controlled release of the encapsulated therapeutics.

Harnessing reactive oxygen/nitrogen species and inflammation: Nanodrugs for liver injury

Overall, 12% of the global population (800 million) suffers from liver disease, which causes 2 million deaths every year. Liver injury involving characteristic reactive oxygen/nitrogen species (RONS) and inflammation plays a key role in progression of liver disease. As a key metabolic organ of the human body, the liver is susceptible to injury from various sources, including COVID-19 infection. Owing to unique structural features and functions of the liver, most current antioxidants and anti-inflammatory drugs are limited against liver injury. However, the characteristics of the liver could be utilized in the development of nanodrugs to achieve specific enrichment in the liver and consequently targeted treatment. Nanodrugs have shown significant potential in eliminating RONS and regulating inflammation, presenting an attractive therapeutic tool for liver disease through controlling liver injury. Therefore, the main aim of the current review is to provide a comprehensive summary of the latest developments contributing to our understanding of the mechanisms underlying nanodrugs in the treatment of liver injury via harnessing RONS and inflammation. Meanwhile, the prospects of nanodrugs for liver injury therapy are systematically discussed, which provides a sound platform for novel therapeutic insights and inspiration for design of nanodrugs to treat liver disease.

Solid Dosage Forms of Biopharmaceuticals in Drug Delivery Systems Using Sustainable Strategies

Drug delivery systems (DDS) often comprise biopharmaceuticals in aqueous form, making them susceptible to physical and chemical degradation, and therefore requiring low temperature storage in cold supply and distribution chains. Freeze-drying, spray-drying, and spray-freeze-drying are some of the techniques used to convert biopharmaceuticals-loaded DDS from aqueous to solid dosage forms. However, the risk exists that shear and heat stress during processing may provoke DDS damage and efficacy loss. Supercritical fluids (SCF), specifically, supercritical carbon dioxide (scCO₂), is a sustainable alternative to common techniques. Due to its moderately critical and tunable properties and thermodynamic behavior, scCO₂ has aroused scientific and industrial interest. Therefore, this article reviews scCO₂-based techniques used over the year in the production of solid biopharmaceutical dosage forms. Looking particularly at the use of scCO₂ in each of its potential roles—as a solvent, co-solvent, anti-solvent, or co-solute. It ends with a comparison between the compound’s stability using supercritical CO₂-assisted atomization/spray-drying and conventional drying.

Performance of High Mobility Protein Group 1 and Interleukin-6 as Predictors of Outcomes Resulting from Variceal Bleeding in Patients with Advanced Chronic Liver Disease

Variceal bleeding is a serious complication in cirrhotic patients and is related to increased expression of inflammatory mediators that accentuate circulatory dysfunction. The study aims to evaluate the performance of high mobility protein group 1 (HMG1) and interleukin-6 (IL-6) as predictors of acute kidney injury (AKI), infection and death in these patients. Fifty patients who were diagnosed with advanced chronic liver disease with variceal bleeding were included. The mean age was 52.8 ± 10.8 years, and 33 (66%) were male. Twenty-one (42%) patients were classified as Child-Pugh C, 21 (42%) Child-Pugh B and 8 (16%) Child-Pugh A. The mean HMG1 serum level was 2872.36 pg/mL ± 2491.94, and the median IL-6 serum level was 47.26 pg/mL (0-1102.4). In AKI, the serum level of HMG1 that performed best on the ROC curve was 3317.9 pg/mL. The IL-6 serum level was not associated with AKI. HMG1 and IL-6 cut-off values that better predicted infection were 3317.9 pg/mL and 72.9 pg/mL, and for mortality, the values were 2668 pg/mL and 84.5 pg/mL, respectively. In multivariate analysis, the variables that were associated with AKI and infection outcomes were model for end-stage liver disease and HMG1. Infections were related to the risk of death. Clinical and laboratory variables related to the outcomes were identified. Serum levels of HMG1 were associated with AKI and infection and had good performance in the ROC curve. IL-6 levels were not maintained in logistic regression outcomes but had good performance in infection and death outcomes. Such data will be useful for comparisons and possible future validations.

Synthesized HMGB1 peptide attenuates liver inflammation and suppresses fibrosis in mice

The liver has a high regenerative ability and can induce spontaneous regression of fibrosis when early liver damage occurs; however, these abilities are lost when chronic liver damage results in decompensated cirrhosis. Cell therapies, such as mesenchymal stem cell (MSC) and macrophage therapies, have attracted attention as potential strategies for mitigating liver fibrosis. Here, we evaluated the therapeutic effects of HMGB1 peptide synthesized from box A of high mobility group box 1 protein. Liver damage and fibrosis were evaluated using a carbon tetrachloride (CCl₄)-induced cirrhosis mouse model. The effects of HMGB1 peptide against immune cells were evaluated by single-cell RNA-seq using liver tissues, and those against monocytes/macrophages were further evaluated by in vitro analyses. Administration of HMGB1 peptide did not elicit a rapid response within 36 h, but attenuated liver damage after 1 week and suppressed fibrosis after 2 weeks. Fibrosis regression developed over time, despite continuous liver damage, suggesting that administration of this peptide could induce fibrolysis. In vitro analyses could not confirm a direct effect of HMGB1 peptide against monocyte/macrophages. However, macrophages were the most affected immune cells in the liver, and the number of scar-associated macrophages (Trem2+Cd9+ cells) with anti-inflammatory markers increased in the liver following HMGB1 treatment, suggesting that indirect effects of monocytes/macrophages were important for therapeutic efficacy. Overall, we established a new concept for cell-free therapy using HMGB1 peptide for cirrhosis through the induction of anti-inflammatory macrophages.

Smart Manganese Dioxide-Based Lanthanide Nanoprobes for Triple-Negative Breast Cancer Precise Gene Synergistic Chemodynamic Therapy

Small interfering RNA (siRNA)-based gene therapy has been widely studied as a promising treatment for malignant triple-negative breast cancer (TNBC), but efficient delivery of siRNA still remains a challenge. In this study, a smart manganese dioxide (MnO2)-based lanthanide nanoprobe therapeutic nanoplatform (ErNPs@MnO2-siS100A4-RGD) was developed for tumor imaging and precise stimuli-responsive S100A4 siRNA (siS100A4)-mediated gene therapy in synergism with chemodynamic therapy (CDT) of TNBC. ErNPs@MnO2-siS100A4-RGD has a tumor microenvironment-responsive capability attributed to the presence of MnO2, which can be degraded by glutathione (GSH) in the tumor region while releasing siRNA and generating Mn2+ to achieve precise gene therapy and a Fenton-like reaction-mediated CDT effect on TNBC. Subsequently, the lanthanide nanoprobes (ErNPs) are exposed to the second near-infrared region (NIR-II) fluorescence emission to realize the precise tumor location. Both the in vitro and in vivo results demonstrated that the smart nanoplatform possessed high siRNA delivery efficiency and GSH-responsive precise siRNA releasing ability, and compared with individual gene therapy, the GSH-depletion-enhanced CDT effect further reinforced TNBC inhibition, demonstrating excellent GSH-responsive-enhanced NIR-II precise tumor imaging therapy. These results indicate that the nanoplatform provides a crucial foundation for further research on theranostic systems of TNBC.

Non-viral nanoparticles for RNA interference: Principles of design and practical guidelines

Ribonucleic acid interference (RNAi) is an innovative treatment strategy for a myriad of indications. Non-viral synthetic nanoparticles (NPs) have drawn extensive attention as vectors for RNAi due to their potential advantages, including improved safety, high delivery efficiency and economic feasibility. However, the complex natural process of RNAi and the susceptible nature of oligonucleotides render the NPs subject to particular design principles and requirements for practical fabrication. Here, we summarize the requirements and obstacles for fabricating non-viral nano-vectors for efficient RNAi. To address the delivery challenges, we discuss practical guidelines for materials selection and NP synthesis in order to maximize RNA encapsulation efficiency and protection against degradation, and to facilitate the cytosolic release of oligonucleotides. The current status of clinical translation of RNAi-based therapies and further perspectives for reducing the potential side effects are also reviewed.

Identification of a potent ionizable lipid for efficient macrophage transfection and systemic anti-interleukin-1β siRNA delivery against acute liver failure

RNA interference (RNAi) therapy has great potential for treating inflammatory diseases. However, the development of potent carrier materials for delivering siRNA to macrophages is challenging. Herein, we design a set of ionizable lipid nanoparticles (LNPs) to screen and identify a potent carrier of siRNA for silencing an essential pro-inflammatory cytokine, interleukin-1β (IL-1β) in macrophages. The top performance LNP (114-LNP), containing ionizable lipid with spermine as an amine-head group, facilitated efficient siRNA internalization via multiple endocytosis pathways and achieved effective endosome escape in macrophages. The optimized LNP/siIL-1β achieved strong silencing of IL-1β in both activated Raw 264.7 cells and primary macrophages. Furthermore, systematic administration of 114-LNP/siIL-1β complexes could effectively inhibit IL-1β expression in an acute liver failure model and significantly attenuated hepatic inflammation and liver damage. These results suggest that the optimized ionizable lipid nanoparticle represents a promising platform for anti-inflammation therapies.

Lipid based nanocarriers for effective drug delivery and treatment of diabetes associated liver fibrosis

Non-alcoholic fatty liver disease (NAFLD) is a cluster of several liver diseases like hepatic steatosis, non-alcoholic steatohepatitis (NASH), non-alcoholic fatty liver (NAFL), liver fibrosis, and cirrhosis which may eventually progress to liver carcinoma. One of the primary key factors associated with the development and pathogenesis of NAFLD is diabetes mellitus. The present review emphasizes on diabetes-associated development of liver fibrosis and its treatment using different lipid nanoparticles such as stable nucleic acid lipid nanoparticles, liposomes, solid lipid nanoparticles, nanostructured lipid carriers, self-nanoemulsifying drug delivery systems, and conjugates including phospholipid, fatty acid and steroid-based. We have comprehensively described the various pathological and molecular events linking effects of elevated free fatty acid levels, insulin resistance, and diabetes with the pathogenesis of liver fibrosis. Various passive and active targeting strategies explored for targeting hepatic stellate cells, a key target in liver fibrosis, have also been discussed in detail in this review.

Tumor microenvironment remodeling-based penetration strategies to amplify nanodrug accessibility to tumor parenchyma

Remarkable advances in nano delivery systems have provided new hope for tumor prevention, diagnosis and treatment. However, only limited clinical therapeutic effects against solid tumors were achieved. One of the main reasons is the presence of abundant physiological and pathological barriers in vivo that impair tumoral penetration and distribution of the nanodrugs. These barriers are related to the components of tumor microenvironment (TME) including abnormal tumor vasculature, rich composition of the extracellular matrix (ECM), and abundant stroma cells. Herein, we review the advanced strategies of TME remodeling to overcome these biological obstacles against nanodrug delivery. This review aims to offer a perspective guideline for the implementation of promising approaches to facilitate intratumoral permeation of nanodrugs through alleviation of biological barriers. At the same time, we analyze the advantages and disadvantages of the corresponding methods and put forward possible directions for the future researches.

Core Role of Hydrophobic Core of Polymeric Nanomicelle in Endosomal Escape of siRNA

Efficient endosomal escape is the most essential but challenging issue for siRNA drug development. Herein, a series of quaternary ammonium-based amphiphilic triblock polymers harnessing an elaborately tailored pH-sensitive hydrophobic core were synthesized and screened. Upon incubating in an endosomal pH environment (pH 6.5-6.8), mPEG₄₅-P(DPA₅₀-co-DMAEMA₅₆)-PT₅₃ (PDDT, the optimized polymer) nanomicelles (PDDT-Ms) and PDDT-Ms/siRNA polyplexes rapidly disassembled, leading to promoted cytosolic release of internalized siRNA and enhanced silencing activity evident from comprehensive analysis of the colocalization and gene silencing using a lysosomotropic agent (chloroquine) and an endosomal trafficking inhibitor (bafilomycin A1). In addition, PDDT-Ms/siPLK1 dramatically repressed tumor growth in both HepG2-xenograft and highly malignant patient-derived xenograft models. PDDT-Ms-armed siPD-L1 efficiently blocked the interaction of PD-L1 and PD-1 and restored immunological surveillance in CT-26-xenograft murine model. PDDT-Ms/siRNA exhibited ideal safety profiles in these assays. This study provides guidelines for rational design and optimization of block polymers for efficient endosomal escape of internalized siRNA and cancer therapy.

Treatment of Hepatic Fibrosis in Mice Based on Targeted Plasmonic Hyperthermia

Liver fibrosis is a major health problem with multiple associated complications, which, to date, has no effective treatment. Hepatic stellate cells are the main responsible cells for fibrosis formation; upon their activation, excess accumulation of extracellular matrix and collagen deposits occurs. The mitogen platelet-derived growth factor (PDGF) and its receptor β (PDGFRβ) play a major role in hepatic stellate cells activation and are, therefore, promising targets for antifibrotic therapies. Gold nanorods hold great potential for diseased liver treatments, since their passive hepatic accumulation enhances active targeting strategies, hence increasing therapeutic efficiency. In addition, gold nanorods have photothermal properties that, combined with specific cell delivery, can be exploited to induce localized near-infrared light-mediated thermal ablation. Here, we demonstrate that gold nanorods coated with anti-PDGFRβ specifically target activated hepatic stellate cells in vivo. Additionally, gold nanorods-PDGFRβ-mediated photothermal therapy decreases fibrosis, hepatic inflammation, and hepatocyte injury in the experimental model of CCl₄-induced liver fibrosis in mice.