Inorganic Nanomaterials as Highly Efficient Inhibitors of Cellular Hepatic Fibrosis

Nano-calcipotriol as a potent anti-hepatic fibrosis agent

Calcipotriol (CAL) has been widely studied as a fibrosis inhibitor and used to treat plaque psoriasis via transdermal administration. The clinical application of CAL to treat liver fibrosis is bottlenecked by its unsatisfactory pharmacokinetics, biodistribution, and side effects, such as hypercalcemia in patients. The exploration of CAL as a safe and effective antifibrotic agent remains a major challenge. Therefore, we rationally designed and synthesized a self-assembled drug nanoparticle encapsulating CAL in its internal hydrophobic core for systematic injection (termed NPs/CAL) and further investigated the beneficial effect of the nanomaterial on liver fibrosis. C57BL/6 mice were used as the animal model, and human hepatic stellate cell line LX-2 was used as the cellular model of hepatic fibrogenesis. Immunofluorescence staining, flow cytometry, western blotting, immunohistochemical staining, and in vitro imaging were used for evaluating the efficacy of NPs/CAL treatment. We found NPs/CAL can be quickly internalized in vitro, thus potently deactivating LX-2 cells. In addition, NPs/CAL improved blood circulation and the accumulation of CAL in liver tissue. Importantly, NPs/CAL strongly contributed to the remission of liver fibrosis without inducing hypercalcemia. Overall, our work identifies a promising paradigm for the development of nanomaterial-based agents for liver fibrosis therapy.

Understanding the Potential Role of Nanotechnology in Liver Fibrosis: A Paradigm in Therapeutics

The liver is a vital organ that plays a crucial role in the physiological operation of the human body. The liver controls the body's detoxification processes as well as the storage and breakdown of red blood cells, plasma protein and hormone production, and red blood cell destruction; therefore, it is vulnerable to their harmful effects, making it more prone to illness. The most frequent complications of chronic liver conditions include cirrhosis, fatty liver, liver fibrosis, hepatitis, and illnesses brought on by alcohol and drugs. Hepatic fibrosis involves the activation of hepatic stellate cells to cause persistent liver damage through the accumulation of cytosolic matrix proteins. The purpose of this review is to educate a concise discussion of the epidemiology of chronic liver disease, the pathogenesis and pathophysiology of liver fibrosis, the symptoms of liver fibrosis progression and regression, the clinical evaluation of liver fibrosis and the research into nanotechnology-based synthetic and herbal treatments for the liver fibrosis is summarized in this article. The herbal remedies summarized in this review article include epigallocathechin-3-gallate, silymarin, oxymatrine, curcumin, tetrandrine, glycyrrhetinic acid, salvianolic acid, plumbagin, Scutellaria baicalnsis Georgi, astragalosides, hawthorn extract, and andrographolides.

Attenuating endothelial leakiness with self-assembled DNA nanostructures for pulmonary arterial hypertension

Vascular endothelium dysfunction plays an important role in oncological and pulmonary diseases. Endothelial barrier dysfunction is the initial step of pulmonary vascular remodeling (PVR) and pulmonary arterial hypertension. Upregulation of a pro-autophagy protein Atg101 in the endothelial cells triggered a cascade of intracellular events that leads to endothelial dysfunction through apoptosis. Herein, we proposed a strategy that used endothelial targeting DNA nanostructures to deliver Atg101 siRNA (siAtg101) as a safe, biocompatible "band-aid" to restore pulmonary arterial endothelial barrier integrity within the intricate milieu of pulmonary cells and the pulmonary vasculature. The siAtg101 and aptamer conjugated DNA nanostructures were found to attenuate hypoxia-induced pulmonary endothelial leakiness with surprisingly high selectivity and efficacy. Further in vivo study revealed that functionalized DNA nanostructures likewise attenuated the vascular remodeling in a monocrotaline-induced PVR mouse model. Mechanistically, functionalized DNA nanostructures suppressed PVR by knocking down Atg101, which in turn, downregulated Beclin-1 and subsequently upregulated VE-cadherin to restore endothelial cells' adherin junctions. This work opened a new window for future nanomaterial design that directly addresses the interfacial endothelial cell layer that often stands between the blood and many diseased sites of nanotherapeutic interest.

Penetration and translocation of functional inorganic nanomaterials into biological barriers

With excellent physicochemical properties, inorganic nanomaterials (INMs) have exhibited a series of attractive applications in biomedical fields. Biological barriers prevent successful delivery of nanomedicine in living systems that limits the development of nanomedicine especially for sufficient delivery of drugs and effective therapy. Numerous researches have focused on overcoming these biological barriers and homogeneity of organisms to enhance therapeutic efficacy, however, most of these strategies fail to resolve these challenges. In this review, we present the latest progress about how INMs interact with biological barriers and penetrate these barriers. We also summarize that both native structure and components of biological barriers and physicochemical properties of INMs contributed to the penetration capacity. Knowledge about the relationship between INMs structure and penetration capacity will guide the design and application of functional and efficient nanomedicine in the future.

Are Ingested or Inhaled Microplastics Involved in Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) has emerged as the predominant cause of chronic liver injury; however, the mechanisms underlying its progression have not been fully elucidated. Pathophysiological studies have stated that NAFLD is significantly influenced by dietary and environmental factors that could participate in the development of NAFLD through different mechanisms. Currently, "plastic pollution" is one of the most challenging environmental problems worldwide since several plastics have potential toxic or endocrine disputing properties. Specifically, the intake of microplastics (MPs) and nanoplastics (NPs) in water or diet and/or the inhalation from suspended particles is well established, and these particles have been found in human samples. Laboratory animals exposed to MPs develop inflammation, immunological responses, endocrine disruptions, and alterations in lipid and energy metabolism, among other disorders. MPs additives also demonstrated adverse reactions. There is evidence that MPs and their additives are potential "obesogens" and could participate in NAFLD pathogenesis by modifying gut microbiota composition or even worsen liver fibrosis. Although human exposure to MPs seems clear, their relationship with NAFLD requires further study, since its prevention could be a possible personalized therapeutic strategy. Adequate mitigation strategies worldwide, reducing environmental pollution and human exposure levels of MPs, could reduce the risk of NAFLD.

Protein-Mimicking Nanoparticles in Biosystems

Proteins are essential elements for almost all life activities. The emergence of nanotechnology offers innovative strategies to create a diversity of nanoparticles (NPs) with intrinsic capacities of mimicking the functions of proteins. These artificial mimics are produced in a cost-efficient and controllable manner, with their protein-mimicking performances comparable or superior to those of natural proteins. Moreover, they can be endowed with additional functionalities that are absent in natural proteins, such as cargo loading, active targeting, membrane penetrating, and multistimuli responding. Therefore, protein-mimicking NPs have been utilized more and more often in biosystems for a wide range of applications including detection, imaging, diagnosis, and therapy. To highlight recent progress in this broad field, herein, representative protein-mimicking NPs that fall into one of the four distinct categories are summarized: mimics of enzymes (nanozymes), mimics of fluorescent proteins, NPs with high affinity binding to specific proteins or DNA sequences, and mimics of protein scaffolds. This review covers their subclassifications, characteristic features, functioning mechanisms, as well as the extensive exploitation of their great potential for biological and biomedical purposes. Finally, the challenges and prospects in future development of protein-mimicking NPs are discussed.

Understanding Nanomaterial-Liver Interactions to Facilitate the Development of Safer Nanoapplications

Nanomaterials (NMs) are widely used in commercial and medical products, such as cosmetics, vaccines, and drug carriers. Exposure to NMs via various routes such as dermal, inhalation, and ingestion has been shown to gain access to the systemic circulation, resulting in the accumulation of NMs in the liver. The unique organ structures and blood flow features facilitate the liver sequestration of NMs, which may cause adverse effects in the liver. Currently, most in vivo studies are focused on NMs accumulation at the organ level and evaluation of the gross changes in liver structure and functions, however, cell-type-specific uptake and responses, as well as the molecular mechanisms at cellular levels leading to effects at organ levels are lagging. Herein, the authors systematically review diverse interactions of NMs with the liver, specifically on major liver cell types including Kupffer cells (KCs), liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs), and hepatocytes as well as the detailed molecular mechanisms involved. In addition, the knowledge gained on nano-liver interactions that can facilitate the development of safer nanoproducts and nanomedicine is also reviewed.

Polystyrene nanoplastics potentiate the development of hepatic fibrosis in high fat diet fed mice

Polystyrene nanoparticles (PS-NPs) as an issue of global environmental concern, have been shown to induce hepatic toxicity via triggering oxidative injury and inflammation. Non-alcoholic fatty liver disease (NAFLD) is initiated when excessive lipid is accumulated in the liver and will proceed to liver fibrosis with repeatedly chronic liver injury. In this study, we examined whether intravenous injection of PS-NPs could enhance the hepatic toxicity and potentiate the development of liver fibrosis in experimental high fat diet (HFD)-induced mice. The results demonstrated that PS-NPs could aggravate chronic hepatitis by interfere with liver lipid metabolism in HFD induced mice. Further, hepatic tissue in PS-NPs treated HFD mice displayed substantially lowered superoxide dismutase (SOD) activity, which confirming the oxidative stress induced by PS-NPs. PS-NPs exposure also resulted in the up-regulation of inflammation response in liver, as evidenced by the enhanced infiltration of Kupffer cells (KCs) and elevated expression of pro-inflammatory related indicators. Meanwhile, Masson trichrome staining revealed that PS-NPs could aggravate steatohepatitis with higher collagen fiber in HFD fed mice. Our data suggests that PS-NPs can induce oxidative stress and inflammation in HDF-induced experimental mice and further aggravate liver fibrosis, which highlight the potential health risks of PS-NPs.

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.

Exploring the Gamut of Receptor Tyrosine Kinases for Their Promise in the Management of Non-Alcoholic Fatty Liver Disease

Recently, non-alcoholic fatty liver disease (NAFLD) has emerged as a predominant health concern affecting approximately a quarter of the world’s population. NAFLD is a spectrum of liver ailments arising from nascent lipid accumulation and leading to inflammation, fibrosis or even carcinogenesis. Despite its prevalence and severity, no targeted pharmacological intervention is approved to date. Thus, it is imperative to identify suitable drug targets critical to the development and progression of NAFLD. In this quest, a ray of hope is nestled within a group of proteins, receptor tyrosine kinases (RTKs), as targets to contain or even reverse NAFLD. RTKs control numerous vital biological processes and their selective expression and activity in specific diseases have rendered them useful as drug targets. In this review, we discuss the recent advancements in characterizing the role of RTKs in NAFLD progression and qualify their suitability as pharmacological targets. Available data suggests inhibition of Epidermal Growth Factor Receptor, AXL, Fibroblast Growth Factor Receptor 4 and Vascular Endothelial Growth Factor Receptor, and activation of cellular mesenchymal-epithelial transition factor and Fibroblast Growth Factor Receptor 1 could pave the way for novel NAFLD therapeutics. Thus, it is important to characterize these RTKs for target validation and proof-of-concept through clinical trials.

Cerium Oxide Nanoparticles Alleviate Hepatic Fibrosis Phenotypes In Vitro

Exposure to metallic nanoparticles (NPs) can result in inadvertent NP accumulation in body tissues. While their subsequent cellular interactions can lead to unintended consequences and are generally regarded as detrimental for health, they can on occasion mediate biologically beneficial effects. Among NPs, cerium oxide nanoparticles (CeO₂ NP) possess strong antioxidant properties and have shown to alleviate certain pathological conditions. Herein, we show that the presence of cubic 25 nm CeO₂ NP was able to reduce TGF-β-mediated activation in the cultured hepatic stellate cell line LX2 by reducing oxidative stress levels and TGF-β-mediated signalling. These cells displayed reduced classical liver fibrosis phenotypes, such as diminished fibrogenesis, altered matrix degradation, decreased cell motility, modified contractability and potentially lowered autophagy. These findings demonstrate that CeO₂ NP may be able to ameliorate hepatic fibrosis and suggest a possible therapeutic pathway for an otherwise difficult-to-treat condition.

Ion therapy of pulmonary fibrosis by inhalation of ionic solution derived from silicate bioceramics

Pulmonary fibrosis (PF) is a chronic and progressively fatal disease, but clinically available therapeutic drugs are limited due to efficacy and side effects. The possible mechanism of pulmonary fibrosis includes the damage of alveolar epithelial cells II (AEC2), and activation of immune cells such as macrophages. The ions released from bioceramics have shown the activity in stimulating soft tissue derived cells such as fibroblasts, endothelia cells and epithelia cells, and regulating macrophage polarization. Therefore, this study proposes an "ion therapy" approach based on the active ions of bioceramic materials, and investigates the therapeutic effect of bioactive ions derived from calcium silicate (CS) bioceramics on mouse models of pulmonary fibrosis. We demonstrate that silicate ions significantly reduce pulmonary fibrosis by simultaneously regulating the functions of AEC2 and macrophages. This result suggests potential clinical applications of ion therapy for lung fibrosis.

Protein-Mimicking Nanoparticles for a Cellular Regulation of Homeostasis

The distinct physical and chemical properties of nanoparticles (NPs) offer great opportunities to develop new strategies for diagnostic and therapeutic purposes. Whereas NPs often serve as inert nanocarriers, their inherent "biological" activities have recently been extensively unveiled and explored. These protein-mimicking NPs (dubbed protmins) have been reported to modulate a cellular homeostasis without displaying a general toxicity, which may act as potential nanomedicines to provide a monotherapy or combination therapy in a disease treatment. In the meanwhile, the unexpected behaviors of protmins in complex biological systems also raise new concerns on the biosafety issue. Herein, we summarize several categories of the protmin-based regulation of cellular homeostasis and discuss their broad effects on cell functions and behaviors.

Nanomedicine for the treatment of diabetes-associated cardiovascular diseases and fibrosis

Cardiomyopathy and fibrosis are the main causes of heart failure in diabetes patients. For therapeutic purposes, a delivery system is required to enhance antidiabetic drug efficacy and specifically target profibrotic pathways in cardiomyocytes. Nanoparticles (NPs) have distinct advantages, including biocompatibility, bioavailability, targeting efficiency, and minimal toxicity, which make them ideal for antidiabetic treatment. In this review, we overview the latest information on the pathogenesis of cardiomyopathy and fibrosis in diabetes patients. We summarize how NP applications improve insulin and liraglutide efficacy and their sustained release upon oral administration. We provide a comprehensive review of the results of NP clinical trials in diabetes patients and of animal studies investigating the effects of NP-mediated anti-fibrotic treatments. Collectively, the application of advanced NP delivery systems in the treatment of cardiomyopathy and fibrosis in diabetes patients is a promising and innovative therapeutic strategy.

The Evaluation of Drug Delivery Nanocarrier Development and Pharmacological Briefing for Metabolic-Associated Fatty Liver Disease (MAFLD): An Update

Current research indicates that the next silent epidemic will be linked to chronic liver diseases, specifically non-alcoholic fatty liver disease (NAFLD), which was renamed as metabolic-associated fatty liver disease (MAFLD) in 2020. Globally, MAFLD mortality is on the rise. The etiology of MAFLD is multifactorial and still incompletely understood, but includes the accumulation of intrahepatic lipids, alterations in energy metabolism, insulin resistance, and inflammatory processes. The available MAFLD treatment, therefore, relies on improving the patient's lifestyle and multidisciplinary pharmacotherapeutic options, whereas the option of surgery is useless without managing the comorbidities of the MAFLD. Nanotechnology is an emerging approach addressing MAFLD, where nanoformulations are suggested to improve the safety and physicochemical properties of conventional drugs/herbal medicines, physical, chemical, and physiological stability, and liver-targeting properties. A wide variety of liver nanosystems were constructed and delivered to the liver, only those that addressed the MAFLD were discussed in this review in terms of the nanocarrier classes, particle size, shape, zeta potential and offered dissolution rate(s), the suitable preparation method(s), excipients (with synergistic effects), and the suitable drug/compound for loading. The advantages and challenges of each nanocarrier and the focus on potential promising perspectives in the production of MAFLD nanomedicine were also highlighted.

Nanoapproaches to Modifying Epigenetics of Epithelial Mesenchymal Transition for Treatment of Pulmonary Fibrosis

Idiopathic Pulmonary Fibrosis (IPF) is a chronically progressive interstitial lung that affects over 3 M people worldwide and rising in incidence. With a median survival of 2-3 years, IPF is consequently associated with high morbidity, mortality, and healthcare burden. Although two antifibrotic therapies, pirfenidone and nintedanib, are approved for human use, these agents reduce the rate of decline of pulmonary function but are not curative and do not reverse established fibrosis. In this review, we discuss the prevailing epithelial injury hypothesis, wherein pathogenic airway epithelial cell-state changes known as Epithelial Mesenchymal Transition (EMT) promotes the expansion of myofibroblast populations. Myofibroblasts are principal components of extracellular matrix production that result in airspace loss and mortality. We review the epigenetic transition driving EMT, a process produced by changes in histone acetylation regulating mesenchymal gene expression programs. This mechanistic work has focused on the central role of bromodomain-containing protein 4 in mediating EMT and myofibroblast transition and initial preclinical work has provided evidence of efficacy. As nanomedicine presents a promising approach to enhancing the efficacy of such anti-IPF agents, we then focus on the state of nanomedicine formulations for inhalable delivery in the treatment of pulmonary diseases, including liposomes, polymeric nanoparticles (NPs), inorganic NPs, and exosomes. These nanoscale agents potentially provide unique properties to existing pulmonary therapeutics, including controlled release, reduced systemic toxicity, and combination delivery. NP-based approaches for pulmonary delivery thus offer substantial promise to modify epigenetic regulators of EMT and advance treatments for IPF.

Preparation and characterization of titanium dioxide nanoparticles and in vitro investigation of their cytotoxicity and antibacterial activity against Staphylococcus aureus and Escherichia coli

Titanium dioxide nanoparticles (TiO₂ NPs) are photo-active metallic nanoparticles becoming promising agents in modern biomedical applications. Herein, a novel process for the synthesis of TiO₂ NPs with high stability was developed by a sol-gel process and to investigate their cytotoxicity and antibacterial activity. Numerous experiments have been performed to confirm the morphologies, compositions, and physicochemical properties of prepared TiO₂ NPs, such as field emission scanning electron microscopy, dynamic light scattering, Zeta potential, Fourier transform infrared spectroscopy and X-ray diffraction. MTT assay was applied to assess the cytotoxicity of the prepared nanoparticles. The results indicate that the synthesized nanoparticles' diameter is about 68 nm and contains the anatase phase, in the range of 2θ from 25 to 80 °C. The hydrodynamic radius of nanoparticles is about 140.4 nm, and the zeta potential of nanoparticles is about -44.6 mV. The MTT results have not shown any toxicity; the antibacterial inhibitory effect of TiO₂ NPs at 200 mg/mL concentrations exhibited superior antibacterial activity at 15.9 ± 0.1, 14.0 ± 0.1 against Staphylococcus aureus and Escherichia coli, respectively. In conclusion, colloidal solutions with high stability were successfully synthesized, contributing to decreased dimensions and increased antibacterial properties.

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.

Nanoarchitectonics beyond Self-Assembly: Challenges to Create Bio-Like Hierarchic Organization

Incorporation of non-equilibrium actions in the sequence of self-assembly processes would be an effective means to establish bio-like high functionality hierarchical assemblies. As a novel methodology beyond self-assembly, nanoarchitectonics, which has as its aim the fabrication of functional materials systems from nanoscopic units through the methodological fusion of nanotechnology with other scientific disciplines including organic synthesis, supramolecular chemistry, microfabrication, and bio-process, has been applied to this strategy. The application of non-equilibrium factors to conventional self-assembly processes is discussed on the basis of examples of directed assembly, Langmuir-Blodgett assembly, and layer-by-layer assembly. In particular, examples of the fabrication of hierarchical functional structures using bio-active components such as proteins or by the combination of bio-components and two-dimensional nanomaterials, are described. Methodologies described in this review article highlight possible approaches using the nanoarchitectonics concept beyond self-assembly for creation of bio-like higher functionalities and hierarchical structural organization.

All Roads Lead to the Liver: Metal Nanoparticles and Their Implications for Liver Health

Metal nanoparticles (NPs) are frequently encountered in daily life, and concerns have been raised about their toxicity and safety. Among which, they naturally accumulate in the liver after introduction into the body, independent of the route of administration. Some NPs exhibit intrinsic pharmaceutical effects that are related to their physical parameters, and their inadvertent accumulation in the liver can exert strong effects on liver function and structure. Even as such physiological consequences are often categorically dismissed as toxic and deleterious, there are cell type-specific and NP-specific biological responses that elicit distinctive pharmacological consequences that can be harnessed for good. By limiting the scope of discussion to metallic NPs, this work attempts to provide a balanced perspective on their safety in the liver, and discusses both possible therapeutic benefits and potential accidental liver damage arising from their interaction with specific parenchymal and nonparenchymal cell types in the liver.

99mTc Radiolabeled HA/TPGS-Based Curcumin-Loaded Nanoparticle for Breast Cancer Synergistic Theranostics: Design, in vitro and in vivo Evaluation

Background

Emerging cancer therapy requires highly sensitive diagnosis in combination with cancer-targeting therapy. In this study, a self-assembled pH-sensitive curcumin (Cur)-loaded nanoparticle of ^99mTc radiolabeled hyaluronan-cholesteryl hemisuccinate conjugates (HA-CHEMS) and D-a-tocopheryl polyethylene glycol succinate (TPGS) was prepared for breast cancer synergistic theranostics.

Materials and Methods

The synthesized amphiphilic HA-CHEMS conjugates and TPGS self-assembled into Cur-loaded nanoparticles (HA-CHEMS-Cur-TPGS NPs) in an aqueous environment. The physicochemical properties of HA-CHEMS-Cur-TPGS NPs were characterized by transmission electron microscopy (TEM) and dynamic lighter scattering (DLS). The in vitro cytotoxicity of HA-CHEMS-Cur-TPGS NPs against breast cancer cells was evaluated by using the methyl thiazolyl tetrazolium (MTT) assay. Moreover, the in vivo animal experiments of HA-CHEMS-Cur-TPGS NPs including SPECT/CT imaging biodistribution and antitumor efficiency were investigated in 4T1 tumor-bearing BALB/c mice; furthermore, pharmacokinetics were investigated in healthy mice.

Results

HA-CHEMS-Cur-TPGS NPs exhibited high curcumin loading, uniform particle size distribution, and excellent stability in vitro. In the cytotoxicity assay, HA-CHEMS-Cur-TPGS NPs showed remarkably higher cytotoxicity to 4T1 cells with an IC50 value at 38 μg/mL, compared with free curcumin (77 μg/mL). Moreover, HA-CHEMS-Cur-TPGS NPs could be effectively and stably radiolabeled with ^99mTc. The SPECT images showed that ^99mTc-HA-CHEMS-Cur-TPGS NPs could target the 4T1 tumor up to 4.85±0.24%ID/g at 4 h post-injection in BALB/c mice. More importantly, the in vivo antitumor efficacy studies showed that HA-CHEMS-Cur-TPGS NPs greatly inhibited the tumor growth without resulting in obvious toxicities to major organs.

Conclusion

The results indicated that HA-CHEMS-Cur-TPGS NPs with stable ^99mTc labeling and high curcumin-loading capacity hold great potential for breast cancer synergistic theranostics.

Chitosan mediated solid lipid nanoparticles for enhanced liver delivery of zedoary turmeric oil in vivo

Zedoary turmeric oil (ZTO) has a strong antitumor activity. However, its volatility, insolubility, low bioavailability, and difficulty of medication owing to oily liquid limit its clinical applications. Solid lipid nanoparticles can provide hydrophobic environment to dissolve hydrophobic drug and solidify the oily active composition to decrease the volatility and facilitate the medication. Chitosan has been widely used in pharmaceutics in recent years and coating with chitosan further enhances the internalization of particles by cells due to charge attract. Here, Chitosan (CS)-coated solid lipid nanoparticles (SLN) loaded with ZTO was prepared and characterized using dynamic laser scanner (DLS) and transmission electron microscope (TEM). The uptake and distribution of drug were evaluated in vitro and in vivo. The average sizes of ZTO-SLN and CS-ZTO-SLN were 134.3 ± 3.42 nm and 210.7 ± 4.59 nm, respectively. CS coating inverted the surface charge of particles from -8.93 ± 1.92 mV to +9.12 ± 2.03 mV. The liver accumulation of CS-ZTO-SLN was higher than ZTO-SLN (chitosan-uncoated particles) by analysis of tissue homogenate using HPLC, and the bioavailability of ZTO was also obviously improved. The results suggested that SLN coated with CS improved the features of ZTO formulation and efficiently deliver drug to the liver.

Nanomaterials as Inhibitors of Epithelial Mesenchymal Transition in Cancer Treatment

Abstract: Epithelial-mesenchymal transition (EMT) has emerged as a key regulator of cell invasion and metastasis in cancers. Besides the acquisition of migratory/invasive abilities, the EMT process is tightly connected with the generation of cancer stem cells (CSCs), thus contributing to chemoresistance. However, although EMT represents a relevant therapeutic target for cancer treatment, its application in the clinic is still limited due to various reasons, including tumor-stage heterogeneity, molecular-cellular target specificity, and appropriate drug delivery. Concerning this last point, different nanomaterials may be used to counteract EMT induction, providing novel therapeutic tools against many different cancers. In this review, (1) we discuss the application of various nanomaterials for EMT-based therapies in cancer, (2) we summarize the therapeutic relevance of some of the proposed EMT targets, and (3) we review the potential benefits and weaknesses of each approach.

Nanoparticles' interactions with vasculature in diseases

The ever-growing use of inorganic nanoparticles (NPs) in biomedicine provides an exciting approach to develop novel imaging and drug delivery systems, owing to the ease with which these NPs can be functionalized to cater to various applications. In cancer therapeutics, nanomedicine generally relies on the enhanced permeability and retention (EPR) effect observed in tumour vasculature to deliver anti-cancer drugs across the endothelium. However, such a phenomenon is dependent on the tumour microenvironment and is not consistently observed in all tumour types, thereby limiting drug transport to the tumour site. On the other hand, there is a rise in utilizing inorganic NPs to intentionally induce endothelial leakiness, creating a window of opportunity to control drug delivery across the endothelium. While this active targeting approach creates a similar phenomenon compared to the EPR effect arising from tumour tissues, its drug delivery applications extend beyond cancer therapeutics and into other vascular-related diseases. In this review, we summarize the current findings of the EPR effect and assess its limitations in the context of anti-cancer drug delivery systems. While the EPR effect offers a possible route for drug passage, we further explore alternative uses of NPs to create controllable endothelial leakiness within short exposures, a phenomenon we coined as nanomaterial-induced endothelial leakiness (NanoEL). Furthermore, we discuss the main mechanistic features of the NanoEL effect that make it unique from conventionally established endothelial leakiness in homeostatic and pathologic conditions, as well as examine its potential applicability in vascular-related diseases, particularly cancer. Therefore, this new paradigm changes the way inorganic NPs are currently being used for biomedical applications.

Ultralong tumor retention of theranostic nanoparticles with short peptide-enabled active tumor homing

Computer tomography (CT) and magnetic resonance imaging (MRI) are noninvasive cancer imaging methods in clinics. Hence, a material that enables MRI/CT dual-modal imaging-guided therapy is in high demand. Currently, the available materials lack active tumor targeting, deep tumor penetration, and ultralong tumor retention and may lose their imaging elements. To overcome these drawbacks, herein, nanoparticles (NPs) were deveopled by integrating an MRI contrast-enhancing chelated gadolinium (Gd) complex within a doxorubicin (DOX)-loaded protective silica shell as well as a CT imaging/photothermal biocompatible bismuth (Bi) nano-core, which surface-displayed an MCF-7 breast tumor-homing peptide (AREYGTRFSLIGGYR, termed AR); we found that the resultant NPs AR-Bi@SiO2-Gd/DOXNPs could home to and penetrate deep into the tumors with the unexpected ultralong retention of at least 14 days (as determined by CT/MRI imaging) and the tumor retention half-life of 104.5 h (as determined by ICP-MS analysis) under the guidance of the AR peptide. These NPs can be further used to image tumors with significantly increased sharp contrasts via both CT and MRI, which are much better than the commercial standard contrast agents; moreover, they significantly inhibit tumor growth via the synergistic action of both Bi-enabled photothermal therapy and DOX-induced chemotherapy. The NPs are cleared by the spleen, liver and kidney and then excreted from the body along with faeces and urine. The precise tumor targeting and ultralong tumor retention of these unique NPs would enable both precise tumor detection for early diagnosis and signal-persistent tumor tracking for monitoring the treatment with only a single injection of these NPs.

Functionalizing NaGdF4:Yb,Er Upconverting Nanoparticles with Bone-Targeting Phosphonate Ligands: Imaging and In Vivo Biodistribution

Lanthanide-doped upconverting nanoparticles (UCNPs) transform near infrared light (NIR) into higher-energy UV and visible light by multiphotonic processes. Owing to such unique feature, UCNPs have found application in optical imaging and have been investigated for the NIR light activation of prodrugs, including transition metal complexes of interest in photochemotherapy. Besides, UCNPs also function as magnetic resonance imaging (MRI) contrast agents and positron emission tomography (PET) probes when labelled with radionuclides such as 18F. In this contribution, we report on a new series of phosphonate-functionalized NaGdF4:Yb,Er UCNPs that show affinity for hydroxyapatite (inorganic constituent of bones), and we discuss their potential as bone targeting multimodal (MRI/PET) imaging agents. In vivo biodistribution studies of 18F-labelled NaGdF4:Yb,Er UCNPs in rats indicate that surface functionalization with phosphonates favours the accumulation of nanoparticles in bones over time. PET results reveal leakage of 18F− for phosphonate-functionalized NaGdF4:Yb,Er and control nanomaterials. However, Gd was detected in the femur for phosphonate-capped UCNPs by ex vivo analysis using ICP-MS, corresponding to 6–7% of the injected dose.

Polypeptide-Conjugated Second Near-Infrared Organic Fluorophore for Image-Guided Photothermal Therapy

Image-guided photothermal therapy (PTT) is an attractive strategy to improve the diagnosis accuracy and treatment outcomes by monitoring the accumulation of photothermal agents in tumors in real-time and determining the best treatment window. Taking advantage of the superior imaging quality of NIR-II fluorescence imaging and remote-controllable phototherapy modality of PTT, we developed a facile macromolecular fluorophore (PF) by conjugating a small-molecule NIR-II fluorophore (Flav7) with an amphiphilic polypeptide. The PF can form uniform micelles in aqueous solution, which exhibit a slight negative charge. In vitro experimental results showed that the PF nanoparticles showed satisfactory photophysical properties, prominent photothermal conversion efficiency (42.3%), excellent photothermal stability, negligible cytotoxicity, and photothermal toxicity. Meanwhile, the PF can visualize and feature the tumors by NIR-II fluorescence imaging owing to prolonged blood circulation time and enhanced accumulation in tumors. Moreover, in vivo studies revealed that the PF nanoparticles achieved an excellent photothermal ablation effect on tumors with a low dose of NIR-II dye and light irradiation, and the process can be traced by NIR fluorescence imaging.

Photostable and Biocompatible Fluorescent Silicon Nanoparticles for Imaging-Guided Co-Delivery of siRNA and Doxorubicin to Drug-Resistant Cancer Cells

The development of effective and safe vehicles to deliver small interfering RNA (siRNA) and chemotherapeutics remains a major challenge in RNA interference-based combination therapy with chemotherapeutics, which has emerged as a powerful platform to treat drug-resistant cancer cells. Herein, we describe the development of novel all-in-one fluorescent silicon nanoparticles (SiNPs)-based nanomedicine platform for imaging-guided co-delivery of siRNA and doxorubicin (DOX). This approach enhanced therapeutic efficacy in multidrug-resistant breast cancer cells (i.e., MCF-7/ADR cells). Typically, the SiNP-based nanocarriers enhanced the stability of siRNA in a biological environment (i.e., medium or RNase A) and imparted the responsive release behavior of siRNA, resulting in approximately 80% down-regulation of P-glycoprotein expression. Co-delivery of P-glycoprotein siRNA and DOX led to > 35-fold decrease in the half maximal inhibitory concentration of DOX in comparison with free DOX, indicating the pronounced therapeutic efficiency of the resultant nanocomposites for drug-resistant breast cancer cells. The intracellular time-dependent release behaviors of siRNA and DOX were revealed through tracking the strong and stable fluorescence of SiNPs. These data provide valuable information for designing effective RNA interference-based co-delivery carriers.

Angiopoietin-1 accelerates restoration of endothelial cell barrier integrity from nanoparticle-induced leakiness

Nanoparticles (NPs) have been widely used in biomedical field for therapeutic treatments, drug carriers, and bio-imaging agent. Recent studies have highlighted the possibility of utilizing inorganic NPs in inducing endothelial leakiness through endothelial remodeling to promote drug transport across the barrier. However, an uncontrolled and persistent leakiness could lead to promiscuous transport of molecules and cells across the barrier, highlighting the pressing need to control the timely recovery from endothelial cell leakiness. Herein, we show that angiopoietin-1 (Ang1) could promote recovery of human microvascular endothelial cells (HMVECs) from titanium dioxide nanoparticle (TiO₂ NPs)-induced endothelial leakiness. Ang1 is known as an anti-permeability growth factor which forms complexes with its receptor Tie2 at the cell-to-cell junctions. We find that the introduction of Ang1 not only accelerates the recovery of NP-induced endothelial leakiness (NanoEL) but also promotes cell rigidity by increasing tubulin acetylation, thereby remodels the endothelial cells to further mitigate the effects of NP exposure through the activation of the Akt pathway. Using in vitro metastasis model, we further show that HMVECs treated with TiO₂ NPs followed by Ang1 could reduce migration of human skin cancer A431 cells across the endothelial barrier. In summary, Ang1 plays important roles in promoting the recovery of endothelial cell leakiness and endothelial stability through a mechano-transduction pathway and shows great potential as key modulator that allows material scientist to regulate endothelial leakiness induced by NPs.

Titanium Dioxide Nanoparticles Enhance Leakiness and Drug Permeability in Primary Human Hepatic Sinusoidal Endothelial Cells

Liver sinusoidal endothelial cells (LSECs) represent the permeable interface that segregates the blood compartment from the hepatic cells, regulating hepatic vascular tone and portal pressure amidst changes in the blood flow. In the presence of pathological conditions, phenotypic changes in LSECs contribute to the progression of chronic liver diseases, including the loss of endothelial permeability. Therefore, modulating LSECs offers a possible way to restore sinusoidal permeability and thereby improve hepatic recovery. Herein, we showed that titanium dioxide nanoparticles (TiO₂ NPs) could induce transient leakiness in primary human hepatic sinusoidal endothelial cells (HHSECs). Interestingly, HHSECs exposed to these NPs exhibited reduced protein kinase B (Akt) phosphorylation, an important protein kinase which regulates cell attachment. Using a 3D co-culture system, we demonstrated that TiO₂ NPs diminished the attachment of HHSECs onto normal human hepatic cell LO2. To further illustrate the significance of leakiness in liver sinusoids, we showed that NP-induced leakiness promoted Sunitinib transport across the HHSEC layer, resulting in increased drug uptake and efficacy. Hence, TiO₂ NPs have the potential to modulate endothelial permeability within the specialized sinusoidal endothelium, especially during events of fibrosis and occlusion. This study highlighted the possible use of inorganic NPs as a novel strategy to promote drug delivery targeting the diseased liver.

Effects of inorganic nanoparticles on liver fibrosis: Optimizing a double-edged sword for therapeutics

Liver fibrosis is a condition of sustained wound healing in response to chronic liver injury caused by various factors such as viral, cholestatic and inflammatory diseases. Despite significant advances in the understanding of the mechanistic details of fibrosis, therapeutic intervention with the use of anti-fibrotic drugs achieved only marginal efficacy. Among which, pharmacokinetics profile of agents leading to off-targeting and suboptimal distribution are the principal limiting factors. Concurrently, inorganic nanoparticles (NPs) have gained significant recognition in biomedicine, owning to their unique physicochemical properties. Since NPs are known to accumulate in well vascularised organs, the intuitive therapeutic targeting of the liver using engineered NPs seems to be a plausible approach in treating liver fibrosis. However, the application of inorganic NPs also raised concerns of its potential long-term impact to humans. Current literatures have reported both negative risks as well as surprising benefits, thus sparking off a needful discussion about the feasibility of using inorganic NPs in treating liver fibrosis. Inorganic NPs entrapped in the liver may pose health risks, particularly due to their non-biodegradability and potential toxicity when accumulated in undesirable concentrations. This highlighted the need to assess the health risk of using inorganic NPs, and also to establish a framework to evaluate the conditions when the beneficial effects of these NPs would outweigh potential risks. Hence, this review takes a balanced approach on assessing the mechanistic details behind inorganic NP-induced biochemical perturbations, which could either alleviate or worsen liver fibrosis. Consequently, it attempts to chart out possibilities for future directions through optimizing therapeutic outcomes by design.