Coordination of rigidity modulation and targeting ligand modification on orally-delivered nanoparticles for the treatment of liver fibrosis

Stiff-Soft Hybrid Biomimetic Nano-Emulsion for Targeted Liver Delivery and Treatment of Early Nonalcoholic Fatty Liver Disease

Background: Nonalcoholic fatty liver disease (NAFLD) poses a risk for numerous metabolic diseases. To date, the U.S. Food and Drug Administration has not yet approved any medications for the treatment of NAFLD, for which developing therapeutic drugs is urgent. Dihydromyricetin (DMY), the most abundant flavonoid in vine tea, has been shown to be hepatoprotective. Its application was limited by low bioavailability in vivo; Methods: In order to improve the bioavailability of DMY and achieve liver-targeted delivery, we designed a DMY-loaded stiff-soft hybrid biomimetic nano drug delivery system (DMY-hNE). The in vivo absorption, distribution, pharmacokinetic profiles, and anti-NAFLD efficacy of DMY-hNE were studied; Results: DMY-hNE was composed of a stiff core and soft shell, which led to enhanced uptake by gastrointestinal epithelial cells and increased penetration of the mucus barrier, thus improving the in vivo absorption, plasma DMY concentration, and liver distribution versus free DMY. In an early NAFLD mouse model, DMY-hNE effectively ameliorated fatty lesions accompanied with reduced lipid levels and liver tissue inflammation; Conclusions: These findings suggested that DMY-hNE is a promising platform for liver drug delivery and treatment of hepatopathy.

Effects of nanoparticle deformability on multiscale biotransport

Deformability is one of the critical attributes of nanoparticle (NP) drug carriers, along with size, shape, and surface properties. It affects various aspects of NP biotransport, ranging from circulation and biodistribution to interactions with biological barriers and target cells. Recent studies report additional roles of NP deformability in biotransport processes, including protein corona formation, intracellular trafficking, and organelle distribution. This review focuses on the literature published in the past five years to update our understanding of NP deformability and its effect on NP biotransport. We introduce different methods of modulating and evaluating NP deformability and showcase recent studies that compare a series of NPs in their performance in biotransport events at all levels, highlighting the consensus and disagreement of the findings. It concludes with a perspective on the intricacy of systematic investigation of NP deformability and future opportunities to advance its control toward optimal drug delivery.

Transepithelial transport of nanoparticles in oral drug delivery: From the perspective of surface and holistic property modulation

Despite the promising prospects of nanoparticles in oral drug delivery, the process of oral administration involves a complex transportation pathway that includes cellular uptake, intracellular trafficking, and exocytosis by intestinal epithelial cells, which are necessary steps for nanoparticles to enter the bloodstream and exert therapeutic effects. Current researchers have identified several crucial factors that regulate the interaction between nanoparticles and intestinal epithelial cells, including surface properties such as ligand modification, surface charge, hydrophilicity/hydrophobicity, intestinal protein corona formation, as well as holistic properties like particle size, shape, and rigidity. Understanding these properties is essential for enhancing transepithelial transport efficiency and designing effective oral drug delivery systems. Therefore, this review provides a comprehensive overview of the surface and holistic properties that influence the transepithelial transport of nanoparticles, elucidating the underlying principles governing their impact on transepithelial transport. The review also outlines the chosen of parameters to be considered for the subsequent design of oral drug delivery systems.

Nanostructure-Mediated Transport of Therapeutics through Epithelial Barriers

The ability to precisely treat human disease is facilitated by the sophisticated design of pharmacologic agents. Nanotechnology has emerged as a valuable approach to creating vehicles that can specifically target organ systems, effectively traverse epithelial barriers, and protect agents from premature degradation. In this review, we discuss the molecular basis for epithelial barrier function, focusing on tight junctions, and describe different pathways that drugs can use to cross barrier-forming tissue, including the paracellular route and transcytosis. Unique features of drug delivery applied to different organ systems are addressed: transdermal, ocular, pulmonary, and oral delivery. We also discuss how design elements of different nanoscale systems, such as composition and nanostructured architecture, can be used to specifically enhance transepithelial delivery. The ability to tailor nanoscale drug delivery vehicles to leverage epithelial barrier biology is an emerging theme in the pursuit of facilitating the efficacious delivery of pharmacologic agents.

Oral targeted drug delivery to post-gastrointestinal sites

As an essential branch of targeted drug delivery, oral targeted delivery is attracting growing attention in recent years. In addition to site-specific delivery for the treatment of locoregional diseases in the gastrointestinal tract (GIT), oral targeted delivery to remote sites beyond the GIT emerges as a cutting-edge research topic. This review aims to provide an overview of the fundamental concepts and most recent advances in this field. Owing to the physiological barriers existing in the GIT, carrier systems should be transported across the enteric epithelia to target remote sites. Recently, pioneer investigations have validated the transport of intact micro- or nanocarriers across gastrointestinal barriers and subsequently to various distal organs and tissues. The microfold (M) cell pathway is the leading mechanism underlying the oral absorption of particulates, but the contribution of the transcellular and paracellular pathways should not be neglected either. In addition to well-acknowledged physicochemical and biological factors, the formation of a protein corona may also influence the biological fate of carrier systems. Although in an early stage of conceptualization, oral targeted delivery to remote diseases has demonstrated promising potential for the treatment of inflammation, tumors, and diseases inflicting the lymphatic and mononuclear phagocytosis systems.

Escape sites from the endo-lysosomal trafficking route manipulate exocytosis of nanoparticles in polar epithelium

The endo-lysosomal pathway is a major barrier for the trans-epithelial transport of nanoparticles (NPs), but escape strategies could facilitate trans-epithelial delivery. Based on the polarization properties of the epithelium, different escape compartments may result in different exocytosis fates of NPs and further affect the delivery efficiency. Therefore, optimizing the escape sites is critical for trans-epithelial delivery. Here, commonly used PEG-coated-poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles were fabricated as model nanoparticles (MNPs) and the intestinal epithelium was chosen as the polarized epithelium. The MNPs were incubated with different endosomolytic agents for early endosomal escape, late endosomal escape and lysosomal escape, respectively. According to in vitro and in vivo studies, MNPs escaping from early endosomes and late endosomes exhibited stronger capacity for trans-epithelial transport than those escaping from lysosomes. By further probing into the mechanism, we surprisingly found that although MNPs escaping from early endosomes quickly egressed from the apical side of epithelia, they were subsequently followed by "reuptake" via caveolae and trafficked through the endoplasmic reticulum-Golgi apparatus (ER/GA) secretory pathway, achieving efficient trans-epithelial transport; MNPs escaping from late endosomes, which were located near the nucleus, were prone to enter the ER/GA for efficient basolateral exocytosis. However, MNPs escaping from lysosomes were detained within cells by autophagosomes. Collectively, our research suggested that early endosomes and late endosomes were ideal escape sites for trans-epithelial delivery.

Airway epithelial-targeted nanoparticle reverses asthma in inhalation therapy

Despite extensive research on corticosteroids for treating asthma, their short residence time in the lungs has limited their therapeutic effects in vivo. Nanoparticles have been widely investigated for inhaled drug delivery due to their potential benefits in prolonging drugs' residence time in the lungs. However, the retention of nanoparticles may be limited by mucus and ciliated epithelium clearance mechanisms in the airway. Herein, we anchored a neonatal-Fc-receptor-targeted peptide (FcBP) onto "mucus-penetrating" polyethylene glycol (PEG) nanoparticles (PEG-NP). Interestingly, the mucus-permeability of PEG-NP was not impaired by FcBP-functionalization. Moreover, FcBP modification enhanced cellular internalization and exocytosis via specific receptor-mediated processes, which subsequently ameliorated transepithelial transport and prolonged pulmonary retention. Importantly, after loading dexamethasone, FcBP-functionalization could effectively help nanoparticles cross the airway epithelial layer and be endocytosed by inflammatory cells, resulting in a marked decrease in inflammatory cytokines. Finally, FcBP modification significantly enhanced the therapeutic effect of dexamethasone-loaded nanoparticles in asthma mice. This study demonstrates that FcBP-functionalized PEG-NP can overcome multiple obstacles in the airway to prolong the pulmonary retention of drugs, providing a promising strategy for inhalation therapy.

Oral nanomedicine biointeractions in the gastrointestinal tract in health and disease

Oral administration is the preferred route of administration based on the convenience for and compliance of the patient. Oral nanomedicines have been developed to overcome the limitations of free drugs and overcome gastrointestinal (GI) barriers, which are heterogeneous across healthy and diseased populations. This review aims to provide a comprehensive overview and comparison of the oral nanomedicine biointeractions in the gastrointestinal tract (GIT) in health and disease (GI and extra-GI diseases) and highlight emerging strategies that exploit these differences for oral nanomedicine-based treatment. We introduce the key GI barriers related to oral delivery and summarize their pathological changes in various diseases. We discuss nanomedicine biointeractions in the GIT in health by describing the general biointeractions based on the type of oral nanomedicine and advanced biointeractions facilitated by advanced strategies applied in this field. We then discuss nanomedicine biointeractions in different diseases and explore how pathological characteristics have been harnessed to advance the development of oral nanomedicine.

Bioinspired fine-tuning of the mechanical rigidity of SNEDDS for the efficient crossing of multiple gastrointestinal barriers

Nanoproperties, such as size, charge, and rigidity, have been demonstrated to be crucial for nanovehicles to overcome numerous gastrointestinal obstacles. However, the facile approach of modifying the rigidity of nanovehicles remains scarce, limiting understanding of how rigidity impacts their oral delivery. Inspired by the fact that cellular phospholipid content regulates plasma membrane rigidity, the rigidity of self-nanoemulsifiying drug delivery system (SNEDDS) could be fine-tuned via phosphocholine content while their size and zeta potential remain unchanged, using insulin as a model drug. Notably, soft SNEDDS exerted longer gastrointestinal transit time, higher drug release rate, stronger gastrointestinal stability and relatively lower mucus permeation but superior epithelial transcytosis than their hard counterparts in a macropinocytosis-dependent manner. The rigidity-related enhanced transcytosis was attributed to improved endocytosis, lysosome escape capability and exocytosis. Rats with type 1 diabetes exhibited greater oral insulin absorption and blood glucose lowering effect with soft SNEDDS. This study demonstrated the regulatory role of phospholipids in nanovehicle rigidity, which could help develop mechanically optimized nanomedicines in the future.

Butyrate Modification Promotes Intestinal Absorption and Hepatic Cancer Cells Targeting of Ferroptosis Inducer Loaded Nanoparticle for Enhanced Hepatocellular Carcinoma Therapy

Sorafenib is an oral-administered first-line drug for hepatocellular carcinoma (HCC) treatment. However, the therapeutic efficacy of sorafenib is relatively low. Here, an oral delivery platform that increases sorafenib uptake by HCC and induces potent ferroptosis is designed. This platform is butyrate-modified nanoparticles separately encapsulated with sorafenib and salinomycin. The multifunctional ligand butyrate interacts with monocarboxylate transporter 1 (MCT-1) to facilitate transcytosis. Specifically, MCT-1 is differentially expressed on the apical and basolateral sides of the intestine, highly expressed on the surface of HCC cells but lowly expressed on normal hepatocytes. After oral administration, this platform is revealed to boost transepithelial transport effectively and continuously in the intestine, drug accumulation in the liver, and HCC cell uptake. Following drug release in cancer cells, sorafenib depletes glutathione peroxidase 4 and glutathione, consequently initiating ferroptosis. Meanwhile, salinomycin enhances intracellular iron and lipid peroxidation, thereby accelerating ferroptosis. In vivo experiments performed on the orthotopic HCC model demonstrate that this combination strategy induces pronounced ferroptosis damage and ignites a robust systemic immune response, leading to the effective elimination of tumors and establishment of systemic immune memory. This work provides a proof-of-concept demonstration that an oral delivery strategy for ferroptosis inducers may be beneficial for HCC treatment.

Modulation of engineered nanomaterial interactions with organ barriers for enhanced drug transport

The biomedical use of nanoparticles (NPs) has been the focus of intense research for over a decade. As most NPs are explored as carriers to alter the biodistribution, pharmacokinetics and bioavailability of associated drugs, the delivery of these NPs to the tissues of interest remains an important topic. To date, the majority of NP delivery studies have used tumor models as their tool of interest, and the limitations concerning tumor targeting of systemically administered NPs have been well studied. In recent years, the focus has also shifted to other organs, each presenting their own unique delivery challenges to overcome. In this review, we discuss the recent advances in leveraging NPs to overcome four major biological barriers including the lung mucus, the gastrointestinal mucus, the placental barrier, and the blood-brain barrier. We define the specific properties of these biological barriers, discuss the challenges related to NP transport across them, and provide an overview of recent advances in the field. We discuss the strengths and shortcomings of different strategies to facilitate NP transport across the barriers and highlight some key findings that can stimulate further advances in this field.

Lysosomal nanotoxicity: Impact of nanomedicines on lysosomal function

Although several nanomedicines got clinical approval over the past two decades, the clinical translation rate is relatively small so far. There are many post-surveillance withdrawals of nanomedicines caused by various safety issues. For successful clinical advancement of nanotechnology, it is of unmet need to realize cellular and molecular foundation of nanotoxicity. Current data suggest that lysosomal dysfunction caused by nanoparticles is emerging as the most common intracellular trigger of nanotoxicity. This review analyzes prospect mechanisms of lysosomal dysfunction-mediated toxicity induced by nanoparticles. We summarized and critically assessed adverse drug reactions of current clinically approved nanomedicines. Importantly, we show that physicochemical properties have great impact on nanoparticles interaction with cells, excretion route and kinetics, and subsequently on toxicity. We analyzed literature on adverse reactions of current nanomedicines and hypothesized that adverse reactions might be linked with lysosomal dysfunction caused by nanomedicines. Finally, from our analysis it becomes clear that it is unjustifiable to generalize safety and toxicity of nanoparticles, since different particles possess distinct toxicological properties. We propose that the biological mechanism of the disease progression and treatment should be central in the optimization of nanoparticle design.

Tuning Targeted Liposome Avidity to Cells via Lipid Phase Separation

The addition of both cell-targeting moieties and polyethylene glycol (PEG) to nanoparticle (NP) drug delivery systems is a standard approach to improve the biodistribution, specificity, and uptake of therapeutic cargo. The spatial presentation of these molecules affects avidity of the NP to target cells in part through an interplay between the local ligand concentration and the steric hindrance imposed by PEG molecules. Here, we show that lipid phase separation in nanoparticles can modulate liposome avidity by changing the proximity of PEG and targeting protein molecules on a nanoparticle surface. Using lipid-anchored nickel-nitrilotriacetic acid (Ni-NTA) as a model ligand, we demonstrate that the attachment of lipid anchored Ni-NTA and PEG molecules to distinct lipid domains in nanoparticles can enhance liposome binding to cancer cells by increasing ligand clustering and reducing steric hindrance. We then use this technique to enhance the binding of RGD-modified liposomes, which can bind to integrins overexpressed on many cancer cells. These results demonstrate the potential of lipid phase separation to modulate the spatial presentation of targeting and shielding molecules on lipid nanocarriers, offering a powerful tool to enhance the efficacy of NP drug delivery systems.

Increasing stiffness promotes pulmonary retention of ligand-directed dexamethasone-loaded nanoparticle for enhanced acute lung inflammation therapy

Inhaled nanoparticles (NPs) need to penetrate the bronchial mucosa to deliver drug payloads deeply in the lung for amplified local therapy. However, the bronchial mucociliary barrier eliminates NPs rapidly, which considerably limits their mucosal penetration. In this study, we find that surface ligand modification and stiffness adjustment of NPs contribute to the significantly enhanced bronchial mucosal absorption and pulmonary retention of inhaled drugs. We utilize neonatal Fc receptor ligand (FcBP) to modify the rationally designed low stiffness NPs (Soft-NP) and high stiffness NPs (Stiff-NP) to target bronchial mucosa. In an acute lung inflammation rat model, after intranasal administration with dexamethasone-loaded NPs, Stiff-NP endowed with FcBP displays superior therapeutic effects. The in vitro data demonstrate that the promotion effect of FcBP to bronchial mucosal absorption of Stiff-NP dominates over Soft-NP. This could be attributed to the higher affinity between ligand-receptor when incorporating FcBP on the Stiff-NP surface. Meanwhile, high stiffness modulates more actin filaments aggregation to mediate endocytosis, along with strengthened Ca2+ signal to enhance exocytosis. Conclusively, we highlight that FcBP-modified NPs with higher stiffness would be a potential pulmonary drug delivery system.

Ligand-modified nanocarriers for oral drug delivery: Challenges, rational design, and applications

Ligand-modified nanocarriers (LMNCs) specific to their targets have attracted increasing interest for enhanced oral drug delivery in recent decades. Although the design of LMNCs for enhanced endocytosis and improved exposure of the loaded drugs through the oral route has received abundant attention, it remains unclear how the design influences their transcellular process, especially the key factors affecting their functions. This review discusses the extracellular and cellular barriers to orally administered LMNCs in the gastrointestinal (GI) tract and new discoveries regarding the GI protein corona and the sequential transport barriers that impede the preplanned movements of LMNCs after oral administration. Furthermore, innovative progress in considering key factors (including target selection, ligand properties, and other important factors) in the rational design of LMNCs for oral drug delivery is presented. In particular, some factors that endow LMNCs with efficient transcytosis rather than only endocytosis are highlighted. Finally, the prospects of orally administered LMNCs in disease therapy for the enhanced oral/local bioavailability of active pharmaceutical ingredients, as well as emerging delivery routes, such as lymphatic drug delivery and systemic location-specific drug release based on oral transcellular LMNCs, are discussed.

Smart active-targeting of lipid-polymer hybrid nanoparticles for therapeutic applications: Recent advances and challenges

The advances in producing multifunctional lipid-polymer hybrid nanoparticles (LPHNs) by combining the biomimetic behavior of liposomes and architectural advantages of polymers have provided great opportunities for selective and efficient therapeutics delivery. The constructed LPHNs exhibit different therapeutic efficacies for special uses based on characteristics of different excipients. However, the high mechanical/structural stability of hybrid nano-systems could be viewed as both a negative property and a positive feature, where the concomitant release of drug molecules in a controllable manner is required. In addition, difficulties in scaling up the LPHNs production, due to involvement of several criteria, limit their application for biomedical fields, especially in monitoring, bioimaging, and drug delivery. To address these challenges bio-modifications have exhibited enormous potential to prepare reproducible LPHNs for site-specific therapeutics delivery, diagnostic and preventative applications. The ever-growing surface bio-functionality has provided continuous vitality to this biotechnology and has also posed desirable biosafety to nanoparticles (NPs). As a proof-of-concept, this manuscript provides a crucial review of coated lipid and polymer NPs displaying excellent surface functionality and architectural advantages. We also provide a description of structural classifications and production methodologies, as well as the biomedical possibilities and translational obstacles in the development of surface modified nanocarrier technology.

Modulation of Colloidal Particle Stiffness for the Exploration of Bio-Nano Interactions

Tuning the physicochemical parameters (e.g., size, shape, and surface chemistry) of colloidal particles (CPs) for the engineering of drug carriers has proven to be a promising approach to improve drug delivery efficacy. Recently, the stiffness of CPs has attracted widespread attention for modulating bio-nano interactions. In this perspective, we outline the strategies for the modulation and characterization of CP stiffness and highlight the importance of CP stiffness in the control over biological interactions. Challenges and opportunities of current and future developments in the modulation of CP stiffness for the exploration of bio-nano interactions in therapeutic delivery are also discussed. This perspective is expected to help thoroughly understand the role of CP stiffness in bio-nano interactions and facilitate the design of CPs as carriers for improved drug and vaccine delivery.