Overcoming physiological barriers by nanoparticles for intravenous drug delivery to the lymph nodes

Uncovering layer by layer the risk of nanoplastics to the environment and human health

Nanoplastics (NPs), defined as plastic particles with dimensions less than 100 nm, have emerged as a persistent environmental contaminant with potential risk to both environment and human health. Nanoplastics might translocate across biological barriers and accumulate in vital organs, leading to inflammatory responses, oxidative stress, and genotoxicity, already reported in several organisms. Disruptions to cellular functions, hormonal balance, and immune responses were also linked to NPs exposure in in vitro assays. Further, NPs have been found to adsorb other pollutants, such as persistent organic pollutants (POPs), and leach additives potentially amplifying their advere impacts, increasing the threat to organisms greater than NPs alone. However, NPs toxic effects remain largely unexplored, requiring further research to elucidate potential risks to human health, especially their accumulation, degradation, migration, interactions with the biological systems and long-term consequences of chronic exposure to these compounds. This review provides an overview of the current state-of-art regarding NPs interactions with environmental pollutants and with biological mechanisms and toxicity within cells.

Drug delivery using gold nanoparticles

Modern nanotechnologies provide various possibilities for efficiently delivering drugs to biological targets. This review focuses on using functionalized gold nanoparticles (GNPs) as a drug delivery platform. Owing to their exceptional size and surface characteristics, GNPs are a perfect drug delivery vehicle for targeted and selective distribution. Several in vitro and in vivo tests have shown how simple it is to tailor these particles to administer chemical medications straight to tumors. The GNP surface can also be coated with ligands to modify drug release or improve selectivity. Moreover, the pharmacological activity can be enhanced by using the photothermal characteristics of the particles.

Advances in molecular imaging and targeted therapeutics for lymph node metastasis in cancer: a comprehensive review

Lymph node metastasis is a critical indicator of cancer progression, profoundly affecting diagnosis, staging, and treatment decisions. This review article delves into the recent advancements in molecular imaging techniques for lymph nodes, which are pivotal for the early detection and staging of cancer. It provides detailed insights into how these techniques are used to visualize and quantify metastatic cancer cells, resident immune cells, and other molecular markers within lymph nodes. Furthermore, the review highlights the development of innovative, lymph node-targeted therapeutic strategies, which represent a significant shift towards more precise and effective cancer treatments. By examining cutting-edge research and emerging technologies, this review offers a comprehensive overview of the current and potential impact of lymph node-centric approaches on cancer diagnosis, staging, and therapy. Through its exploration of these topics, the review aims to illuminate the increasingly sophisticated landscape of cancer management strategies focused on lymph node assessment and intervention.

Impact of nanoparticle properties on immune cell interactions in the lymph node

The lymphatic system plays an important role in health and many diseases, such as cancer, autoimmune, cardiovascular, metabolic, hepatic, viral, and other infectious diseases. The lymphatic system is, therefore, an important treatment target site for a range of diseases. Lymph nodes (LNs), rich in T cells, B cells, dendritic cells, and macrophages, are also primary sites of action for vaccines and immunotherapies. Promoting the delivery of therapeutics and vaccines to LNs can, therefore, enhance treatment efficacy and facilitate avoidance of off-target side effects by enabling a reduction in therapeutic dose. Several nanoparticle (NP) based delivery systems, such as polymeric NPs, lipid NPs, liposomes, micelles, and dendrimers, have been reported to enhance the delivery of therapeutics and/or vaccines to LNs. Specific uptake into the lymph following injection into tissues is highly dependent on particle properties, particularly particle size, as small molecules are more likely to be taken up by blood capillaries due to higher blood flow rates, whereas larger molecules and NPs can be specifically transported via the lymphatic vessels to LNs as the initial lymphatic capillaries are more permeable than blood capillaries. Once NPs enter LNs, particle properties also have an important influence on their disposition within the node and association with immune cells, which has significant implications for the design of vaccines and immunotherapies. This review article focuses on the impact of NP properties, such as size, surface charge and modification, and route of administration, on lymphatic uptake, retention, and interactions with immune cells in LNs. We suggest that optimizing all these factors can enhance the efficacy of vaccines or therapeutics with targets in the lymphatics and also be helpful for the rational design of vaccines. STATEMENT OF SIGNIFICANCE: The lymphatic system plays an essential role in health and is an important treatment target site for a range of diseases. Promoting the delivery of immunotherapies and vaccines to immune cells in lymph nodes can enhance efficacy and facilitate avoidance of off-target side effects by enabling a reduction in therapeutic dose. One of the major approaches used to deliver therapeutics and vaccines to lymph nodes is via injection in nanoparticle delivery systems. This review aims to provide an overview of the impact of nanoparticle properties, such as size, surface charge, modification, and route of administration, on lymphatic uptake, lymph node retention, and interactions with immune cells in lymph nodes. This will inform the design of future improved nanoparticle systems for vaccines and immunotherapies.

Spatiotemporal Nano-Regulator Unleashes Anti-Tumor Immunity by Overcoming Dendritic Cell Tolerance and T Cell Exhaustion in Tumor-Draining Lymph Nodes

Lymph nodes are crucial immune foci as the primary target for cancer immunotherapy. However, the anti-tumor functions of tumor-draining lymph nodes (TDLNs) are critically suppressed by tumors. Here, a novel spatiotemporal nano-regulator is presented, designed to modulate the dendritic cells (DCs) in TDLNs, establishing a supportive niche for immune surveillance. The DC-mediated nano-regulator (DNR) is established by the self-assembly of an imidazoquinoline (IMDQ) prodrug, inhibitory immune checkpoint (ICP) siRNA, and mannan (a TLR4 agonist). This unique design leverages the spatiotemporal activation of TLR4 and TLR7/8, thereby optimizing DC maturation and cytokine production. This further promotes efficient T cell priming. Simultaneously, the ICP-targeting siRNA mitigates the tolerogenic effects induced by tumor-derived factors and TLR activation, preventing T cell exhaustion. In essence, DNR facilitates potent remodeling of TDLNs and the tumor microenvironment, activating the anti-tumor immunity cascade. When combined with vaccines, DNR greatly promotes tumor regression and the establishment of long-term immunological memory.

Different leukocyte subsets are targeted by systemic and locoregional administration despite conserved nanomaterial characteristics optimal for lymph node delivery

Lymph nodes (LNs) house a large proportion of the body's leukocytes. Accordingly, engineered nanomaterials are increasingly developed to direct therapeutics to LNs to enhance their efficacy. Yet while lymphatic delivery of nanomaterials to LNs upon locoregional injection has been extensively evaluated, nanomaterial delivery to LN-localized leukocytes after intravenous administration has not been systematically explored nor benchmarked. In this work, a panel of inert, fluorescent nanoscale tracers and drug delivery vehicles were utilized to interrogate intravenous versus locoregionally administered nanomaterial access to LNs and leukocyte subsets therein. Hydrodynamic size and material effects on LN accumulation extents were similar between intravenous versus intradermal injection routes. Nanomaterial distribution to various LN leukocyte subsets differed substantially with injection route, however, in a manner not proportional to total LN accumulation. While intravenously administered nanomaterials accumulated in LNs lowly compared to systemic tissues, in sharp contrast to locoregional delivery, they exhibited size-dependent but material-independent access to immune cells within the LN parenchyma, which are not easily accessed with locoregional delivery.

The menace of severe adverse events and deaths associated with viral gene therapy and its potential solution

Over the past decade, in vivo gene replacement therapy has significantly advanced, resulting in market approval of numerous therapeutics predominantly relying on adeno-associated viral vectors (AAV). While viral vectors have undeniably addressed several critical healthcare challenges, their clinical application has unveiled a range of limitations and safety concerns. This review highlights the emerging challenges in the field of gene therapy. At first, we discuss both the role of biological barriers in viral gene therapy with a focus on AAVs, and review current landscape of in vivo human gene therapy. We delineate advantages and disadvantages of AAVs as gene delivery vehicles, mostly from the safety perspective (hepatotoxicity, cardiotoxicity, neurotoxicity, inflammatory responses etc.), and outline the mechanisms of adverse events in response to AAV. Contribution of every aspect of AAV vectors (genomic structure, capsid proteins) and host responses to injected AAV is considered and substantiated by basic, translational and clinical studies. The updated evaluation of recent AAV clinical trials and current medical experience clearly shows the risks of AAVs that sometimes overshadow the hopes for curing a hereditary disease. At last, a set of established and new molecular and nanotechnology tools and approaches are provided as potential solutions for mitigating or eliminating side effects. The increasing number of severe adverse reactions and, sadly deaths, demands decisive actions to resolve the issue of immune responses and extremely high doses of viral vectors used for gene therapy. In response to these challenges, various strategies are under development, including approaches aimed at augmenting characteristics of viral vectors and others focused on creating secure and efficacious non-viral vectors. This comprehensive review offers an overarching perspective on the present state of gene therapy utilizing both viral and non-viral vectors.

Ferulic Acid: A Comprehensive Review

Ferulic acid (FA), a phenolic compound abundant in the cell walls of seeds, leaves, and roots of various fruits, vegetables, cereals, and grains, is renowned for its wide range of biological activities, including antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. Despite its therapeutic potential, the clinical application of FA is hindered by challenges such as poor water solubility, limited bioavailability, rapid metabolism, and instability under physiological conditions. To address these issues, nanotechnology has emerged as a transformative approach, enhancing FA's pharmacokinetic profile. Various nanoparticle-based systems, including polymer-based and lipid-based nanoparticles, have been developed to encapsulate FA. These systems have demonstrated significant improvements in FA's solubility, stability, and bioavailability, with studies showing enhanced antioxidant activity and controlled release profiles. Further, the surface engineering of these nanoparticles provides targeted drug/phytochemical delivery potential. The targeted delivery of drugs/phytochemicals significantly enhances the therapeutic efficacy and minimizes systemic side effects. This review explores the therapeutic potential of FA, the limitations in its clinical application, and the advancements in nanoparticle-based delivery systems that are paving the way for its effective therapeutic use.

Stepwise Ultra-pH-Sensitive Micelles Overcome a pKa Barrier for Systemic Lymph Node Delivery

While local nanoparticle delivery to lymph nodes is well studied, there are few design criteria for intravenous delivery to the entire lymph node repertoire. In this study, we investigated the effect of NP pH transition on lymph node targeting by employing a series of ultra-pH-sensitive (UPS) polymeric micelles. The UPS library responds to pH thresholds (pKa 6.9, 6.2, and 5.3) over a range of physiological pH. We observed a dependence of intravenous lymph node targeting on micelle pH transition. UPS6.9 (subscript indicates pKa) shows poor lymph node delivery, while UPS5.3 delivers efficiently to lymph node sets. We investigated targeting mechanisms of UPS5.3, observing an accumulation among lymph node lymphatics and a dependence on lymph node-resident macrophages. To overcome the pH-threshold barrier, which limits UPS6.9, we rationally designed a nanoparticle coassembly of UPS6.9 with UPS5.3, called HyUPS. The HyUPS micelle retains the constitutive pH transitions of each polymer, showing stepwise responses to discrete pH thresholds. We demonstrate that HyUPS improves UPS6.9 delivery to lymph nodes, extending this platform for disease detection of lymph node metastasis.

Synthesis of ionizable lipopolymers using split-Ugi reaction for pulmonary delivery of various size RNAs and gene editing

We present an efficient approach for synthesizing cationic poly(ethylene imine) derivatives using the multicomponent split-Ugi reaction to rapidly create a library of complex functional ionizable lipopolymers. We synthesized a diverse library of 155 polymers, formulated them into polyplexes to establish structure-activity relationships crucial for endosomal escape and efficient transfection. After discovering a lead structure, lipopolymer-lipid hybrid nanoparticles are introduced to preferentially deliver to and elicit effective mRNA transfection in lung endothelium and immune cells, including T cells with low in vivo toxicity. The lipopolymer-lipid hybrid nanoparticles showed 300-fold improvement in systemic mRNA delivery to the lung compared to in vivo -JetPEI ® . Lipopolymer-lipid hybrid nanoparticles demonstrated efficient delivery of mRNA-based therapeutics for treatment of two different disease models. Lewis Lung cancer progression was significantly delayed after treatment with loaded IL-12 mRNA in U155@lipids after repeated i.v. administration. Systemic delivery of human CFTR (hCFTR) mRNA resulted in production of functional form of CFTR protein in the lungs. The functionality of hCFTR protein was confirmed by restoration of CFTR- mediated chloride secretion in conductive airway epithelia in CFTR knockout mice after nasal instillation of hCFTR mRNA loaded U155@lipids. We further showed that, U155@lipids nanoparticles can deliver complex CRISPR-Cas9 based RNA cargo to the lung, achieving 5.6 ± 2.4 % gene editing in lung tissue. Moreover, we demonstrated successful PD-1 gene knockout of T cells in vivo . Our results highlight a versatile delivery platform for systemic delivering of mRNA of various sizes for gene therapy for a variety of therapeutics.

Targeting lymph nodes for enhanced cancer vaccination: From nanotechnology to tissue engineering

Lymph nodes (LNs) occupy a critical position in initiating and augmenting immune responses, both spatially and functionally. In cancer immunotherapy, tumor-specific vaccines are blooming as a powerful tool to suppress the growth of existing tumors, as well as provide preventative efficacy against tumorigenesis. Delivering these vaccines more efficiently to LNs, where antigen-presenting cells (APCs) and T cells abundantly reside, is under extensive exploration. Formulating vaccines into nanomedicines, optimizing their physiochemical properties, and surface modification to specifically bind molecules expressed on LNs or APCs, are common routes and have brought encouraging outcomes. Alternatively, porous scaffolds can be engineered to attract APCs and provide an environment for them to mature, proliferate and migrate to LNs. A relatively new research direction is inducing the formation of LN-like organoids, which have shown positive relevance to tumor prognosis. Cutting-edge advances in these directions and discussions from a future perspective are given here, from which the up-to-date pattern of cancer vaccination will be drawn to hopefully provide basic guidance to future studies.

Interactions between nanoparticles and lymphatic systems: Mechanisms and applications in drug delivery

The lymphatic system has garnered significant attention in drug delivery research due to the advantages it offers, such as enhancing systemic exposure and enabling lymph node targeting for nanomedicines via the lymphatic delivery route. The journey of drug carriers involves transport from the administration site to the lymphatic vessels, traversing the lymph before entering the bloodstream or targeting specific lymph nodes. However, the anatomical and physiological barriers of the lymphatic system play a pivotal role in influencing the behavior and efficiency of carriers. To expedite research and subsequent clinical translation, this review begins by introducing the composition and classification of the lymphatic system. Subsequently, we explore the routes and mechanisms through which nanoparticles enter lymphatic vessels and lymph nodes. The review further delves into the interactions between nanomedicine and body fluids at the administration site or within lymphatic vessels. Finally, we provide a comprehensive overview of recent advancements in lymphatic delivery systems, addressing the challenges and opportunities inherent in current systems for delivering macromolecules and vaccines.

Controllable synthesis of barium carbonate nano- and microparticles for SPECT and CT imaging

The design and synthesis of nano- and microcarriers for preclinical and clinical imaging are highly attractive due to their unique features, for example, multimodal properties. However, broad translation of these carriers into clinical practice is postponed due to the unknown biological reactivity of the new components used for their synthesis. Here, we have developed microcarriers (∼2-3 μm) and  nanocarriers (<200 nm) made of barium carbonate (BaCO3) for multiple imaging applications in vivo. In general, barium in the developed carriers can be used for X-ray computed tomography, and the introduction of a diagnostic isotope (99mTc) into the BaCO3 structure enables in vivo visualization using single-photon emission computed tomography. The bioimaging has shown that the radiolabeled BaCO3 nano- and microcarriers had different biodistribution profiles and tumor accumulation efficiencies after intratumoral and intravenous injections. In particular, in the case of intratumoral injection, all the types of used carriers mostly remained in the tumors (>97%). For intravenous injection, BaCO3 microcarriers were mainly localized in the lung tissues. However, BaCO3 NPs were mainly accumulated in the liver. These results were supported by ex vivo fluorescence imaging, direct radiometry, and histological analysis. The BaCO3-based micro- and nanocarriers showed negligible in vivo toxicity towards major organs such as the heart, lungs, liver, kidneys, and spleen. This study provides a simple strategy for the design and fabrication of the BaCO3-based carriers for the development of dual bioimaging.

Impact of conjugation to different lipids on the lymphatic uptake and biodistribution of brush PEG polymers

Delivery to peripheral lymphatics can be achieved following interstitial administration of nano-sized delivery systems (nanoparticles, liposomes, dendrimers etc) or molecules that hitchhike on endogenous nano-sized carriers (such as albumin). The published work concerning the hitchhiking approach has mostly focussed on the lymphatic uptake of vaccines conjugated directly to albumin binding moieties (ABMs such as lipids, Evans blue dye derivatives or peptides) and their subsequent trafficking into draining lymph nodes. The mechanisms underpinning access and transport of these constructs into lymph fluid, including potential interaction with other endogenous nanocarriers such as lipoproteins, have largely been ignored. Recently, we described a series of brush polyethylene glycol (PEG) polymers containing end terminal short-chain or medium-chain hydrocarbon tails (1C2 or 1C12, respectively), cholesterol moiety (Cho), or medium-chain or long-chain diacylglycerols (2C12 or 2C18, respectively). We evaluated the association of these materials with albumin and lipoprotein in rat plasma, and their intravenous (IV) and subcutaneous (SC) pharmacokinetic profiles. Here we fully detail the association of this suite of polymers with albumin and lipoproteins in rat lymph, which is expected to facilitate lymph transport of the materials from the SC injection site. Additionally, we characterise the thoracic lymph uptake, tissue and lymph node biodistribution of the lipidated brush PEG polymers following SC administration to thoracic lymph cannulated rats. All polymers had moderate lymphatic uptake in rats following SC dosing with the lymph uptake higher for 1C2-PEG, 2C12-PEG and 2C18-PEG (5.8%, 5.9% and 6.7% dose in lymph, respectively) compared with 1C12-PEG and Cho-PEG (both 1.5% dose in lymph). The enhanced lymph uptake of 1C2-PEG, 2C12-PEG and 2C18-PEG appeared related to their association profile with different lipoproteins. The five polymers displayed different biodistribution patterns in major organs and tissues in mice. All polymers reached immune cells deep within the inguinal lymph nodes of mice following SC dosing. The ability to access these immune cells suggests the potential of the polymers as platforms for the delivery of vaccines and immunotherapies. Future studies will focus on evaluating the lymphatic targeting and therapeutic potential of drug or vaccine-loaded polymers in pre-clinical disease models.

Intervaginal space injection of photothermal chemotherapy nanoparticles for facilitating tumor targeting and improving outcomes in mice

Although numerous photothermal nanoparticles have been designed to improve the enhanced and permeability and retention (EPR) effect, the delivery of nanoparticles to the tumor site remains a major obstacle in cancer treatment. The interstital structure and its internal fluid that play an important role in material transmission, intercellular signal transduction, tissue morphology, immunity, tumor development, and disease diagnosis and treatment may be considered as a new route for drug delivery. Here, we prepared a nanoplatform composed of polydopamine (PDA), indocyanine green (ICG) as a photothermal agent, and paclitaxel (PTX) as a chemotherapeutic drug. The designed PDA-ICG nanoparticles displayed excellent photothermal conversion ability, with the synergistic effect of PTX, the growth of MDA-MB-231 cells was significantly suppressed with the cell viability of 6.19% in vitro. Taking advantage of bioimaging ability of ICG, tumor-targeting of the nanoparticles injected into the interstitial space was study, Compared with intravenous injection, nanoparticles better targeted the tumor based on the interstitial fluid flow in MBA-MD-231 bearing mice. Furthermore, the antitumor efficacy was studied in vivo. With the improved accumulation of PDA-ICG-PTX nanoparticles injected into the interstitial space and the synergistic effect of photothermal therapy and chemotherapy, tumor growth was inhibited without obvious side effects. These results demonstrated that interstitial space injection may be a superior administration route for tumor-targeting nanoparticles. The PDA-ICG-PTX nanoparticles delivered via the interstitial space exhibit great potential in the photothermal chemotherapy of cancers.

Biomimetic nanoparticles of platelet membranes carrying bFGF and VEGFA genes promote deep burn wound healing

INTRODUCTION

The treatment of burn wounds, especially deep burn wounds, remains a major clinical challenge. Growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor A (VEGFA) show great potential in promoting the healing of damaged tissues. This study explored wound healing following targeted delivery of bFGF and VEGFA genes into deep burn wounds through a novel platelet membrane-coated nanoparticle (PM@gene-NP) complex delivery system.

METHODS

First, bFGF and VEGFA genes were inserted into plasmid (pEGFP-N1) vectors. Subsequently, the assembled plasmids were loaded onto nanoparticles to form gene-loaded nanoparticle complexes, which were then wrapped with extracted platelet membrane, fully simulating the characteristics of platelets, in order to actively target sites of inflammatory damage. After administration of PM@gene-NP complexes through the tail vein of rats, a series of experiments were conducted to evaluate wound healing.

RESULTS

The PM@gene-NP complexes effectively targeted the burn sites. After the administration of the PM@gene-NP complexes, the rats exhibited increased blood flow in the burn wounds, which also healed faster than control groups. Histological results showed fewer inflammatory cells in the burned skin tissue after treatment. After the wounds healed, the production of hair follicles, sebaceous glands and other skin accessories in the skin tissue increased.

CONCLUSION

Our results showed that the PM@gene-NP complexes can effectively deliver gene therapy to the injured area, and this delivery system should be considered as a potential method for treating deep burns.

Battle of the milky way: Lymphatic targeted drug delivery for pathogen eradication

Many viruses, bacteria, and parasites rely on the lymphatic system for survival, replication, and dissemination. While conventional anti-infectives can combat infection-causing agents in the bloodstream, they do not reach the lymphatic system to eradicate the pathogens harboured there. This can result in ineffective drug exposure and reduce treatment effectiveness. By developing effective lymphatic delivery strategies for antiviral, antibacterial, and antiparasitic drugs, their systemic pharmacokinetics may be improved, as would their ability to reach their target pathogens within the lymphatics, thereby improving clinical outcomes in a variety of acute and chronic infections with lymphatic involvement (e.g., acquired immunodeficiency syndrome, tuberculosis, and filariasis). Here, we discuss approaches to targeting anti-infective drugs to the intestinal and dermal lymphatics, aiming to eliminate pathogen reservoirs and interfere with their survival and reproduction inside the lymphatic system. These include optimized lipophilic prodrugs and drug delivery systems that promote lymphatic transport after oral and dermal drug intake. For intestinal lymphatic delivery via the chylomicron pathway, molecules should have logP values >5 and long-chain triglyceride solubilities >50 mg/g, and for dermal lymphatic delivery via interstitial lymphatic drainage, nanoparticle formulations with particle size between 10 and 100 nm are generally preferred. Insight from this review may promote new and improved therapeutic solutions for pathogen eradication and combating infective diseases, as lymphatic system involvement in pathogen dissemination and drug resistance has been neglected compared to other pathways leading to treatment failure.

Advances in nanomedicines for lymphatic imaging and therapy

Lymph nodes play a pivotal role in tumor progression as key components of the lymphatic system. However, the unique physiological structure of lymph nodes has traditionally constrained the drug delivery efficiency. Excitingly, nanomedicines have shown tremendous advantages in lymph node-specific delivery, enabling distinct recognition and diagnosis of lymph nodes, and hence laying the foundation for efficient tumor therapies. In this review, we comprehensively discuss the key factors affecting the specific enrichment of nanomedicines in lymph nodes, and systematically summarize nanomedicines for precise lymph node drug delivery and therapeutic application, including the lymphatic diagnosis and treatment nanodrugs and lymph node specific imaging and identification system. Notably, we delve into the critical challenges and considerations currently facing lymphatic nanomedicines, and futher propose effective strategies to address these issues. This review encapsulates recent findings, clinical applications, and future prospects for designing effective nanocarriers for lymphatic system targeting, with potential implications for improving cancer treatment strategies.

Effective treatment of metastatic sentinel lymph nodes by dual-targeting melittin nanoparticles

Sentinel lymph node (SLN) metastasis is an important promoter of distant metastasis in breast cancer. Therefore, the timely diagnosis and precise treatment are crucial for patient staging and prognosis. However, the simultaneous diagnosis of metastasis and the implementation of imaging-guided SLN therapy is challenging. Here, we report a melittin-loaded and hyaluronic acid (HA)-conjugated high-density lipoprotein (HDL) mimic phospholipid scaffold nanoparticle (MLT-HA-HPPS), which dually-target to both breast cancer and its SLN and efficiently inhibit SLN metastasis in the LN metastasis model. The melittin peptide was successfully loaded onto HA-HPPS via electrostatic interactions, and MLT-HA-HPPS possesses effective cytotoxicity for breast cancer 4T1 cells. Moreover, the effective delivery of MLT-HA-HPPS from the primary tumor into SLN is monitored by NIR fluorescence imaging, which greatly benefits the prognosis and treatment of metastatic SLNs. After paracancerous administration, MLT-HA-HPPS can efficiently inhibit primary tumor growth with an inhibition rate of 81.3% and 76.5% relative to the PBS-treated control group and HA-HPPS group, respectively. More importantly, MLT-HA-HPPS can effectively inhibit the growth of the metastatic SLNs with an approximately 78.0%, 79.1%, and 64.2% decrease in SLNs weight than those in PBS, HA-HPPS, and melittin-treated mice, respectively. Taken together, the MLT-HA-HPPS may provide an encouraging theranostic of SLN drug delivery strategy to inhibit primary tumor progression and prevent SLN metastasis of breast cancer.

NIR-II Fluorescence Imaging for the Detection and Resection of Cancerous Foci and Lymph Nodes in Early-Stage Orthotopic and Advanced-Stage Metastatic Ovarian Cancer Models

The high mortality rate of ovarian cancer can be primarily attributed to late diagnosis and early lymph node (LN) metastasis. The anatomically deep-located ovaries own intricate anatomical structures and lymphatic drainages that compromise the resolution and sensitivity of near-infrared first-window (NIR-I) fluorescence imaging. Reported NIR-II imaging studies of ovarian cancer focused on late-stage metastasis detection via the intraperitoneal xenograft model. However, given the significant improvement in patient survival associated with early-stage cancer detection, locating tumors that are restricted within the ovary is equally crucial. We obtained the polymer nanoparticles with bright near-infrared-II fluorescence (NIR-II NPs) by nanoprecipitation of DSPE-PEG, one of the ingredients of FDA-approved nanoparticle products, and benzobisthiadiazole, an organic NIR-II dye. The one-step synthesis and safe component lay the groundwork for its clinical translation. Benefiting from the NIR-II emission (∼1060 nm), NIR-II NPs enabled a high signal-to-noise (S/N) ratio (13.4) visualization of early-stage orthotopic ovarian tumors with NIR-II fluorescence imaging for the first time. Imaging with orthotopic xenograft allows a more accurate mimic of human ovarian cancer origin, thereby addressing the dilemma of translating existing nanoprobe preclinical research by providing the nano-bio interactions with early local tumor environments. After PEGylation, the desirable-sized probe (∼80 nm) exhibited high lymphophilicity and relatively extended circulation. NIR-II NPs maintained their accurate detection of orthotopic tumors, tumor-regional LNs, and minuscule (<1 mm) disseminated peritoneal metastases simultaneously (with S/N ratios all above 5) in mice with advanced-stage cancer in real time ∼36 h after systematic delivery. With NIR-II fluorescence guidance, we achieved accurate surgical staging in tumor-bearing mice and complete tumor removal comparable to clinical practice, which provides preclinical data for translating NIR-II fluorescence image-guided surgery.

Application of Nano-Delivery Systems in Lymph Nodes for Tumor Immunotherapy

Immunotherapy has become a promising research "hotspot" in cancer treatment. "Soldier" immune cells are not uniform throughout the body; they accumulate mostly in the immune organs such as the spleen and lymph nodes (LNs), etc. The unique structure of LNs provides the microenvironment suitable for the survival, activation, and proliferation of multiple types of immune cells. LNs play an important role in both the initiation of adaptive immunity and the generation of durable anti-tumor responses. Antigens taken up by antigen-presenting cells in peripheral tissues need to migrate with lymphatic fluid to LNs to activate the lymphocytes therein. Meanwhile, the accumulation and retaining of many immune functional compounds in LNs enhance their efficacy significantly. Therefore, LNs have become a key target for tumor immunotherapy. Unfortunately, the nonspecific distribution of the immune drugs in vivo greatly limits the activation and proliferation of immune cells, which leads to unsatisfactory anti-tumor effects. The efficient nano-delivery system to LNs is an effective strategy to maximize the efficacy of immune drugs. Nano-delivery systems have shown beneficial in improving biodistribution and enhancing accumulation in lymphoid tissues, exhibiting powerful and promising prospects for achieving effective delivery to LNs. Herein, the physiological structure and the delivery barriers of LNs were summarized and the factors affecting LNs accumulation were discussed thoroughly. Moreover, developments in nano-delivery systems were reviewed and the transformation prospects of LNs targeting nanocarriers were summarized and discussed.

A core-satellite micellar system against primary tumors and their lymphatic metastasis through modulation of fatty acid metabolism blockade and tumor-associated macrophages

Lymph nodes (LNs) are the initial sanctuary of various metastatic tumor cells, and thus a precise lymphatic drug delivery strategy is necessary for the effective inhibition of metastasis. However, the complex biological barriers have restrained the drug delivery to tumor-draining lymph nodes (TDLNs). Metastatic tumor cells would undergo metabolic adaptation towards fatty acid oxidation (FAO) upon reaching the lipid-rich LNs. Herein, to inhibit primary tumors and their lymphatic metastasis, a core-satellite matrix metalloproteinase 2 (MMP-2) responsive micellar system was developed for sequential delivery of paclitaxel (PTX) and the metabolism-regulating drug etomoxir (ET) to tumors and TDLNs, respectively. Upon arrival at the tumor microenvironment (TME), the small satellite micelle encapsulating ET was detached from the core micelle in response to MMP-2, which not only drained to TDLNs via tumor-draining lymphatic vessels and inhibited the FAO of metastatic tumor cells, but also blocked M2-like macrophage polarization in the TME. Meanwhile, the core micelle containing PTX could largely accumulate in the TME and kill tumor cells. In an orthotopic 4T1 breast cancer model, the tumor and TDLN dual-targeted core-satellite micellar system effectively inhibited the growth of the primary tumor and alleviated immune suppression by blocking macrophage polarization. More importantly, tumor lymphatic metastasis was suppressed through FAO metabolic regulation. This strategy provides a promising approach for TDLN targeted therapy against breast cancer and its lymphatic metastasis.

Nanobiotechnological approaches in osteosarcoma therapy: Versatile (nano)platforms for theranostic applications

Constructive achievements in the field of nanobiotechnology and their translation into clinical course have led to increasing attention towards evaluation of their use for treatment of diseases, especially cancer. Osteosarcoma (OS) is one of the primary bone malignancies that affects both males and females in childhood and adolescence. Like other types of cancers, genetic and epigenetic mutations account for OS progression and several conventional therapies including chemotherapy and surgery are employed. However, survival rate of OS patients remains low and new therapies in this field are limited. The purpose of the current review is to provide a summary of nanostructures used in OS treatment. Drug and gene delivery by nanoplatforms have resulted in an accumulation of therapeutic agents for tumor cell suppression. Furthermore, co-delivery of genes and drugs by nanostructures are utilized in OS suppression to boost immunotherapy. Since tumor cells have distinct features such as acidic pH, stimuli-responsive nanoparticles have been developed to appropriately target OS. Besides, nanoplatforms can be used for biosensing and providing phototherapy to suppress OS. Furthermore, surface modification of nanoparticles with ligands can increase their specificity and selectivity towards OS cells. Clinical translation of current findings suggests that nanoplatforms have been effective in retarding tumor growth and improving survival of OS patients.

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.

Locoregional Lymphatic Delivery Systems Using Nanoparticles and Hydrogels for Anticancer Immunotherapy

The lymphatic system has gained significant interest as a target tissue to control cancer progress, which highlights its central role in adaptive immune response. Numerous mechanistic studies have revealed the benefits of nano-sized materials in the transport of various cargos to lymph nodes, overcoming barriers associated with lymphatic physiology. The potential of sustained drug delivery systems in improving the therapeutic index of various immune modulating agents is also being actively discussed. Herein, we aim to discuss design rationales and principles of locoregional lymphatic drug delivery systems for invigorating adaptive immune response for efficient antitumor immunotherapy and provide examples of various advanced nanoparticle- and hydrogel-based formulations.

Biomimetic nanoparticles directly remodel immunosuppressive microenvironment for boosting glioblastoma immunotherapy

Glioblastoma (GBM), as a very aggressive cancer of central nervous system, is very challenging to completely cure by the conventional combination of surgical resection with radiotherapy and chemotherapy. The success of emerging immunotherapy in hot tumors has attracted considerable interest for the treatment of GBM, but the unique tumor immunosuppressive microenvironment (TIME) of GBM leads to the failure of immunotherapy. Here, we show the significant improvement of the immunotherapy efficacy of GBM by modulating the TIME through novel all-in-one biomimetic nanoparticles (i.e. CS-I/J@CM NPs). The nanoparticles consist of utrasmall Cu_2-x Se nanoparticles (NPs) with outstanding intrinsic properties (e.g., photo-responsive Fenton-like catalytic property for inducing immunogenic cell death (ICD) and alleviating the hypoxia of tumor), indoximod (IND, an inhibitor of indoleamine-2,3-dioxygenease in tumor), JQ1 (an inhibitor for reducing the expression of PD-L1 by tumor cells), and tumor cell membrane for improving the targeting capability and accumulation of nanoparticles in tumor. We reveal that these smart CS-I/J@CM NPs could drastically activate the immune responses through remodeling TIME of GBM by multiple functions. They could (1) increase M1-phenotype macrophages at tumor site by promoting the polarization of tumor-associated macrophages through the reactive oxygen species (ROS) and oxygen generated from the Fenton-like reaction between nanoparticles and H₂O₂ within tumor under NIR II irradiation; (2) decrease the infiltration of Tregs cells at tumor site through the release of IND; (3) decrease the expression of PD-L1 on tumor cells through JQ1. The notable increments of anti-tumor CD8⁺T cells in the tumor and memory T cells (T_EM) in the spleen show excellent therapy efficacy and effectively prevent the recurrence of GBM after modulation of the TIME. This work demonstrates the modulation of TIME could be a significant strategy to improve the immunotherapy of GBM and other cold tumors.

Biomimetic Nanotherapeutics: Employing Nanoghosts to fight Melanoma

Melanoma is a cancer of melanocytes present at the basal layer of the skin. Nanomedicine has armed us with competent platform to manage such fatal neoplastic diseases. Nevertheless, it suffers from numerous pitfalls such as rapid clearance and opsonization of surface-functionalized carriers, biocompatibility and idiopathic reactions which could be difficult to predict in the patient. Biomimetic approach, a novel step towards personalized medicine bridges these drawbacks by employing endogenous cell membranes to traverse physiological barriers. Camouflaged carriers coated with natural cell membranes possess unique characteristics such as high circulatory periods, and the absence of allogenic and xenogenic responses. Proteins residing on the cell membranes render a diverse range of utilities to the coated nanoparticles including natural efficiency to identify cellular targets, homologous targeting, reticuloendothelial system evasion, biocompatibility and reduced adverse and idiopathic effects. In the present article, we have focused on cell membrane camouflaged nanocarriers for melanoma management. We have discussed various types of biomimetic systems, their processing and coating approaches, and their characterization. We have also enumerated novel avenues in melanoma treatment and the combination of biomimetic systems with smart nanoparticulate systems with the potential to bring breakthroughs in the near future. Additionally, immunotherapy-based biomimetic systems to combat melanoma have been highlighted. Hurdles towards clinical translation and ways to overcome them have been explained in detail.