Aerosol Delivery of Functionalized Gold Nanoparticles Target and Activate Dendritic Cells in a 3D Lung Cellular Model

Harnessing Immunomodulatory Polymers for Treatment of Autoimmunity, Allergy, and Transplant Rejection

Autoimmunity, allergy, and transplant rejection are a collection of chronic diseases that are currently incurable, drastically decrease patient quality of life, and consume considerable health care resources. Underlying each of these diseases is a dysregulated immune system that results in the mounting of an inflammatory response against self or an innocuous antigen. As a consequence, afflicted patients are required to adhere to lifelong regimens of multiple immunomodulatory drugs to control disease and reclaim agency. Unfortunately, current immunomodulatory drugs are associated with a myriad of side effects and adverse events, such as increased risk of cancer and increased risk of serious infection, which negatively impacts patient adherence rates and quality of life. The field of immunoengineering is a new discipline that aims to harness endogenous biological pathways to thwart disease and minimize side effects using novel biomaterial-based strategies. We highlight and discuss polymeric micro/nanoparticles with inherent immunomodulatory properties that are currently under investigation in biomaterial-based therapies for treatment of autoimmunity, allergy, and transplant rejection.

Solid Lipid Nanoparticles for Pulmonary Delivery of Biopharmaceuticals: A Review of Opportunities, Challenges, and Delivery Applications

Biopharmaceuticals such as nucleic acids, proteins, and peptides constitute a new array of treatment modalities for chronic ailments. Invasive routes remain the mainstay of administering biopharmaceuticals due to their labile nature in the biological environment. However, it is not preferred for long-term therapy due to the lack of patient adherence and clinical suitability. Therefore, alternative routes of administration are sought to utilize novel biopharmaceutical therapies to their utmost potential. Nanoparticle-mediated pulmonary delivery of biologics can facilitate both local and systemic disorders. Solid lipid nanoparticles (SLNs) afford many opportunities as pulmonary carriers due to their physicochemical stability and ability to incorporate both hydrophilic and hydrophobic moieties, thus allowing novel combinatorial drug/gene therapies. These applications include pulmonary infections, lung cancer, and cystic fibrosis, while systemic delivery of biomolecules, like insulin, is also attractive for the treatment of chronic ailments. This Review explores physiological and particle-associated factors affecting pulmonary delivery of biopharmaceuticals. It compares the advantages and limitations of SLNs as pulmonary nanocarriers along with design improvements underway to overcome these limitations. Current research illustrating various SLN designs to deliver proteins, peptides, plasmids, oligonucleotides, siRNA, and mRNA is also summarized.

Exploration of inorganic nanoparticles for revolutionary drug delivery applications: a critical review

The nanosystems for delivering drugs which have evolved with time, are being designed for greater drug efficiency and lesser side-effects, and are also complemented by the advancement of numerous innovative materials. In comparison to the organic nanoparticles, the inorganic nanoparticles are stable, have a wide range of physicochemical, mechanical, magnetic, and optical characteristics, and also have the capability to get modified using some ligands to enrich their attraction towards the molecules at the target site, which makes them appealing for bio-imaging and drug delivery applications. One of the strong benefits of using the inorganic nanoparticles-drug conjugate is the possibility of delivering the drugs to the affected cells locally, thus reducing the side-effects like cytotoxicity, and facilitating a higher efficacy of the therapeutic drug. This review features the direct and indirect effects of such inorganic nanoparticles like gold, silver, graphene-based, hydroxyapatite, iron oxide, ZnO, and CeO2 nanoparticles in developing effective drug carrier systems. This article has remarked the peculiarities of these nanoparticle-based systems in pulmonary, ocular, wound healing, and antibacterial drug deliveries as well as in delivering drugs across Blood-Brain-Barrier (BBB) and acting as agents for cancer theranostics. Additionally, the article sheds light on the plausible modifications that can be carried out on the inorganic nanoparticles, from a researcher's perspective, which could open a new pathway.

Aerosol pulmonary immune engineering

Aerosolization of immunotherapies poses incredible potential for manipulating the local mucosal-specific microenvironment, engaging specialized pulmonary cellular defenders, and accessing mucosal associated lymphoid tissue to redirect systemic adaptive and memory responses. In this review, we breakdown key inhalable immunoengineering strategies for chronic, genetic, and infection-based inflammatory pulmonary disorders, encompassing the historic use of immunomodulatory agents, the transition to biological inspired or derived treatments, and novel approaches of complexing these materials into drug delivery vehicles for enhanced release outcomes. Alongside a brief description of key immune targets, fundamentals of aerosol drug delivery, and preclinical pulmonary models for immune response, we survey recent advances of inhaled immunotherapy platforms, ranging from small molecules and biologics to particulates and cell therapies, as well as prophylactic vaccines. In each section, we address the formulation design constraints for aerosol delivery as well as advantages for each platform in driving desirable immune modifications. Finally, prospects of clinical translation and outlook for inhaled immune engineering are discussed.

An In Vitro Alveolar Model Allows for the Rapid Assessment of Particles for Respiratory Sensitization Potential

Dust, both industrial and household, contains particulates that can reach the most distal aspects of the lung. Silica and nickel compounds are two such particulates and have known profiles of poor health outcomes. While silica is well-characterized, nickel compounds still need to be fully understood for their potential to cause long-term immune responses in the lungs. To assess these hazards and decrease animal numbers used in testing, investigations that lead to verifiable in vitro methods are needed. To understand the implications of these two compounds reaching the distal aspect of the lungs, the alveoli, an architecturally relevant alveolar model consisting of epithelial cells, macrophages, and dendritic cells in a maintained submerged system, was utilized for high throughput testing. Exposures include crystalline silica (SiO₂) and nickel oxide (NiO). The endpoints measured included mitochondrial reactive oxygen species and cytostructural changes assessed via confocal laser scanning microscopy; cell morphology evaluated via scanning electron microscopy; biochemical reactions assessed via protein arrays; transcriptome assessed via gene arrays, and cell surface activation markers evaluated via flow cytometry. The results showed that, compared to untreated cultures, NiO increased markers for dendritic cell activation, trafficking, and antigen presentation; oxidative stress and cytoskeletal changes, and gene and cytokine expression of neutrophil and other leukocyte chemoattractants. The chemokines and cytokines CCL3, CCL7, CXCL5, IL-6, and IL-8 were identified as potential biomarkers of respiratory sensitization.

Biomaterials Facilitating Dendritic Cell-Mediated Cancer Immunotherapy

Dendritic cell (DC)-based cancer immunotherapy has exhibited remarkable clinical prospects because DCs play a central role in initiating and regulating adaptive immune responses. However, the application of traditional DC-mediated immunotherapy is limited due to insufficient antigen delivery, inadequate antigen presentation, and high levels of immunosuppression. To address these challenges, engineered biomaterials have been exploited to enhance DC-mediated immunotherapeutic effects. In this review, vital principal components that can enhance DC-mediated immunotherapeutic effects are first introduced. The parameters considered in the rational design of biomaterials, including targeting modifications, size, shape, surface, and mechanical properties, which can affect biomaterial optimization of DC functions, are further summarized. Moreover, recent applications of various engineered biomaterials in the field of DC-mediated immunotherapy are reviewed, including those serve as immune component delivery platforms, remodel the tumor microenvironment, and synergistically enhance the effects of other antitumor therapies. Overall, the present review comprehensively and systematically summarizes biomaterials related to the promotion of DC functions; and specifically focuses on the recent advances in biomaterial designs for DC activation to eradicate tumors. The challenges and opportunities of treatment strategies designed to amplify DCs via the application of biomaterials are discussed with the aim of inspiring the clinical translation of future DC-mediated cancer immunotherapies.

Lessons from the history of inorganic nanoparticles for inhalable diagnostics and therapeutics

The respiratory tract is one of the most accessible ones to exogenous nanoparticles, yet drug delivery by their means to it is made extraordinarily challenging because of the plexus of aerodynamic, hemodynamic and biomolecular factors at cellular and extracellular levels that synergistically define the safety and efficacy of this process. Here, the use of inorganic nanoparticles (INPs) for inhalable diagnostics and therapies of the lung is viewed through the prism of the history of studies on the interaction of INPs with the lower respiratory tract. The most conceptually and methodologically innovative and illuminative studies are referred to in the chronological order, as they were reported in the literature, and the trends in the progress of understanding this interaction of immense therapeutic and toxicological significance are being deduced from it. The most outstanding actual trends delineated include the diminishment of toxicity via surface functionalization, cell targeting, tagging and tracking via controlled binding and uptake, hybrid INP treatments, magnetic guidance, combined drug and gene delivery, use as adjuvants in inhalable vaccines, and other. Many of the understudied research directions, which have been accomplished by the nanostructured organic polymers in the pulmonary niche, are discussed. The progress in the use of INPs as inhalable diagnostics or therapeutics has been hampered by their well-recognized inflammatory potential and toxicity in the respiratory tract. However, the annual numbers of methodologically innovative studies have been on the rise throughout the past two decades, suggesting that this is a prolific direction of research, its comparatively poor commercial takings notwithstanding. Still, the lack of consensus on the effects of many INP compositions at low but therapeutically effective doses, the plethora of contradictory reports on ostensibly identical chemical compositions and NP properties, and the many cases of antagonism in combinatorial NP treatments imply that the rational design of inhalable medical devices based on INPs must rely on qualitative principles for the most part and embrace a partially stochastic approach as well. At the same time, the fact that the most studied INPs for pulmonary applications have been those with some of the thickest records of pulmonary toxicity, e.g., carbon, silver, gold, silica and iron oxide, is a silent call for the expansion of the search for new inorganic compositions for use in inhalable therapies to new territories.

Mechanisms by Which Liposomes Improve Inhaled Drug Delivery for Alveolar Diseases

Diseases of the pulmonary alveolus, such as pulmonary fibrosis, are leading causes of morbidity and mortality, but exceedingly few drugs are developed for them. A major reason for this gap is that after inhalation, drugs are quickly whisked away from alveoli due to their high perfusion. To solve this problem, the mechanisms by which nano-scale drug carriers dramatically improve lung pharmacokinetics using an inhalable liposome formulation containing nintedanib, an antifibrotic for pulmonary fibrosis, are studied. Direct instillation of liposomes in murine lung increases nintedanib's total lung delivery over time by 8000-fold and lung half life by tenfold, compared to oral nintedanib. Counterintuitively, it is shown that pulmonary surfactant neither lyses nor aggregates the liposomes. Instead, each lung compartment (alveolar fluid, alveolar leukocytes, and parenchyma) elutes liposomes over 24 h, likely serving as "drug depots." After deposition in the surfactant layer, liposomes are transferred over 3-6 h to alveolar leukocytes (which take up a surprisingly minor 1-5% of total lung dose instilled) in a nonsaturable fashion. Further, all cell layers of the lung parenchyma take up liposomes. These and other mechanisms elucidated here should guide engineering of future inhaled nanomedicine for alveolar diseases.

Gold nanoparticles inhibit tumor growth via targeting the Warburg effect in a c-Myc-dependent way

Gold nanoparticles (AuNPs) are prospective tools for nano-based medicine that can directly target cellular biological processes to influence cell fate and function. Studies have revealed the essential role of AuNPs in metabolic remodeling for macrophage polarization. Nevertheless, as a hallmark of cancer cells, metabolic changes in tumor cells in response to AuNPs have not yet been reported. In the present study, polymer- and folate-conjugated AuNPs with satisfactory biocompatibility and tumor-targeting activity were synthesized to investigate their underlying roles in tumor metabolism. Tumor cells were significantly suppressed by AuNPs in vitro and in vivo, with little cytotoxicity in non-tumor cells. Subcellular localization showed that AuNPs localized in the mitochondria of tumor cells and impaired their structure and function, leading to excessive oxidative stress and mitochondrial apoptosis. Metabolic stress, with decreased glycolysis and insufficient nutrients, was also caused by AuNPs exposure in tumor cells. Mechanistically, the key enzymes (GLUT1 and HK2) for glycolysis modulation were remarkably reduced by AuNPs in a c-Myc-dependent manner. The present study demonstrated a new mechanism for AuNPs in the inhibition of tumor growth, that is, via directly targeting glycolysis and depriving energy. These findings provide new strategies for the design of nano-based medicines and anti-glycolytic therapeutics to inhibit the development of malignant tumors. STATEMENT OF SIGNIFICANCE: Gold nanoparticles (AuNPs) have acquired ever-increasing interest for applications in cancer treatment and diagnosis due to their high biosafety and facile surface modification. Recent studies have shown that AuNPs can work as active agents to directly target the cellular processes and harbor antitumor properties, while the underlying mechanisms remain largely unknown. From the present findings, the stabilized AuNPs showed direct inhibition effects on tumor growth by glycolysis inhibition and energy deprivation. These results provide new insights of AuNPs for tumor treatments, which will further contribute to the development of promising nano-based medicines and anti-glycolytic therapies.

In-vivo processing of nanoassemblies: a neglected framework for recycling to bypass nanotoxicological therapeutics

The proof-of-concept of nanomaterials (NMs) in the fields of imaging, diagnosis, treatment, and theranostics shows the importance in biopharmaceuticals development due to structural orientation, on-targeting, and long-term stability. However, biotransformation of NMs and their modified form in human body via recyclable techniques are not explored owing to tiny structures and cytotoxic effects. Recycling of NMs offers advantages of dose reduction, re-utilization of the administered therapeutics providing secondary release, and decrease in nanotoxicity in human body. Therefore, approaches like in-vivo re-processing and bio-recycling are essential to overcome nanocargo system-associated toxicities such as hepatotoxicity, nephrotoxicity, neurotoxicity, and lung toxicity. After 3-5 stages of recycling process of some NMs of gold, lipid, iron oxide, polymer, silver, and graphene in spleen, kidney, and Kupffer's cells retain biological efficiency in the body. Thus, substantial attention towards recyclability and reusability of NMs for sustainable development necessitates further advancement in healthcare for effective therapy. This review article outlines biotransformation of engineered NMs as a valuable source of drug carriers and biocatalyst with critical strategies like pH modification, flocculation, or magnetization for recovery of NMs in the body. Furthermore, this article summarizes the challenges of recycled NMs and advances in integrated technologies such as artificial intelligence, machine learning, in-silico assay, etc. Therefore, potential contribution of NM's life-cycle in the recovery of nanosystems for futuristic developments require consideration in site-specific delivery, reduction of dose, remodeling in breast cancer therapy, wound healing action, antibacterial effect, and for bioremediation to develop ideal nanotherapeutics.

Nanomaterials-Based Novel Immune Strategies in Clinical Translation for Cancer Therapy

Immunotherapy shows a lot of promise for addressing the problems with traditional cancer treatments. Researchers and clinicians are working to create innovative immunological techniques for cancer detection and treatment that are more selective and have lower toxicity. An emerging field in cancer therapy, immunomodulation offers patients an alternate approach to treating cancer. These therapies use the host's natural defensive systems to identify and remove malignant cells in a targeted manner. Cancer treatment is now undergoing somewhat of a revolution due to recent developments in nanotechnology. Diverse nanomaterials (NMs) have been employed to overcome the limits of conventional anti-cancer treatments such as cytotoxic, surgery, radiation, and chemotherapy. Aside from that, NMs could interact with live cells and influence immune responses. In contrast, unexpected adverse effects such as necrosis, hypersensitivity, and inflammation might result from the immune system (IS)'s interaction with NMs. Therefore, to ensure the efficacy of immunomodulatory nanomaterials, it is essential to have a comprehensive understanding of the intricate interplay that exists between the IS and NMs. This review intends to present an overview of the current achievements, challenges, and improvements in using immunomodulatory nanomaterials (iNMs) for cancer therapy, with an emphasis on elucidating the mechanisms involved in the interaction between NMs and the immune system of the host.

Cell Cultures at the Air-Liquid Interface and Their Application in Cancer Research

Air-liquid interface (ALI) cell cultures are considered a valid tool for the replacement of animals in biomedical research. By mimicking crucial features of the human in vivo epithelial barriers (e.g., lung, intestine, and skin), ALI cell cultures enable proper structural architectures and differentiated functions of normal and diseased tissue barriers. Thereby, ALI models realistically resemble tissue conditions and provide in vivo-like responses. Since their implementation, they are routinely used in several applications, from toxicity testing to cancer research, receiving an appreciable level of acceptance (in some cases a regulatory acceptance) as attractive testing alternatives to animals. In this chapter, an overview of the ALI cell cultures will be presented together with their application in cancer cell culture, highlighting the potential advantages and disadvantages of the model.

Narrative review on century of respiratory pandemics from Spanish flu to COVID-19 and impact of nanotechnology on COVID-19 diagnosis and immune system boosting

The rise of the highly lethal severe acute respiratory syndrome-2 (SARS-2) as corona virus 2019 (COVID-19) reminded us of the history of other pandemics that happened in the last century (Spanish flu) and stayed in the current century, which include Severe-Acute-Respiratory-Syndrome (SARS), Middle-East-Respiratory-Syndrome (MERS), Corona Virus 2019 (COVID-19). We review in this report the newest findings and data on the origin of pandemic respiratory viral diseases, reservoirs, and transmission modes. We analyzed viral adaption needed for host switch and determinants of pathogenicity, causative factors of pandemic viruses, and symptoms and clinical manifestations. After that, we concluded the host factors associated with pandemics morbidity and mortality (immune responses and immunopathology, ages, and effect of pandemics on pregnancy). Additionally, we focused on the burdens of COVID-19, non-pharmaceutical interventions (quarantine, mass gatherings, facemasks, and hygiene), and medical interventions (antiviral therapies and vaccines). Finally, we investigated the nanotechnology between COVID-19 analysis and immune system boosting (Nanoparticles (NPs), antimicrobial NPs as antivirals and immune cytokines). This review presents insights about using nanomaterials to treat COVID-19, improve the bioavailability of the abused drugs, diminish their toxicity, and improve their performance.

Elastic Nanovaccine Enhances Dendritic Cell-Mediated Tumor Immunotherapy

Nanovaccine-based immunotherapy (NBI) has the ability to initiate dendritic cell (DC)-mediated tumor-specific immune responses and maintain long-term antitumor immune memory. To date, the mechanism by which the mechanical properties of nanoparticles alter the functions of DCs in NBI remains largely unclear. Here, a soft mesoporous organosilica-based nanovaccine (SMONV) is prepared and the elasticity-dependent effect of the nanovaccine on the underlying DC-mediated immune responses is studied. It is found that the elasticity results in greater internalization of SMONV by DCs, followed by the induction of substantial cytosolic delivery of antigens via endosomal escape, leading to effective DC maturation and antigen cross-presentation. Impressively, elasticity enables SMONV to enhance lymphatic drainage of antigens in vivo, thus stimulating robust humoral and cellular immunity. The results from therapeutic tumor vaccination further reveal that subcutaneously administered SMONV effectively suppresses tumor growth in tumor-bearing mice by evoking antigen-specific CD8⁺ T-cell immune responses, mitigating regulatory T-cell-mediated immunosuppression, and increasing central memory and effector memory T-cell populations. Furthermore, combinatorial immunization with SMONV and anti-PD-L1 blocking antibodies results in an amplified therapeutic effect on tumor-bearing mice. These findings reveal the elastic effect of the nanovaccine on DC-mediated immune responses, and the prepared SMONV represents a facile and powerful strategy for antitumor immunotherapy.

Photoswitchable CRISPR/Cas12a-Amplified and Co3O4@Au Nanoemitter Based Triple-Amplified Diagnostic Electrochemiluminescence Biosensor for Detection of miRNA-141

In this work, a CRISPR/Cas12a initiated switchable ternary electrochemiluminescence (ECL) biosensor combined with a Co3O4@Au nanoemitter is presented for the in vitro monitoring of miRNA-141. Benefiting from the advantages of high-throughput cargo payload capability and superconductivity, three-dimensional reduced graphene oxide (3D-rGO) was designated as an introductory conducting stratum of a paper working electrode (PWE). With the collaborative participation of Co3O4@Au NPs, the transmutation of TPrA in the Ru(bpy)32+/TPrA system can be riotously expedited into exorbitant free radical ions TPrA•, which provoked the exaggeration of the ECL signal. Moreover, the programmable enzyme-free hybrid chain reaction (HCR) amplifier on the PWE surface accurately anchored the assembly of nucleic acid tandem and accomplished the secondary recursion of the signal. Impressively, the multifunctional CRISPR/Cas12a with nonspecific cis/trans-splitting decomposition manipulated the photoswitch of the "on-off" signal state that avoided the false-positive diagnosis. The presented multistrategy cooperative biosensor demonstrated extraordinary sensitivity and specificity, with a low detection limit of 3.3 fM (S/N = 3) in the concentration scope from 10 fM to 100 nM, which fully corresponded to the expectation. Overall, this innovative methodology paved a generous avenue for evaluating multifarious biotransformations and provided a tremendous impetus to the development of real-time diagnosis and clinical detection of other biomarkers.

Nanotechnology-based therapeutics for targeting inflammatory lung diseases

The physiochemical properties of drugs used in treating inflammation-associated lung diseases (i.e., asthma, chronic obstructive pulmonary disease, pulmonary fibrosis) play an important role in determining the effectiveness of formulations. Most commonly used drugs are associated with low solubility, low stability and rapid clearance, thus resulting in low bioavailability and therapeutic index. This review focuses on current trends and development of drugs (i.e., corticosteroids, long-acting β-agonists and biomacromolecules such as DNA, siRNA and mRNA) employed to treat inflammatory lung diseases. In addition, this review includes the current challenges of and future perspective with regard to nanotechnology in the treatment of inflammatory lung diseases.

Targeting innate immune system by nanoparticles for cancer immunotherapy

Various cancer therapies have advanced remarkably over the past decade. Unlike the direct therapeutic targeting of tumor cells, cancer immunotherapy is a new strategy that boosts the host's immune system...

Tailoring the physicochemical properties of nanomaterials for immunomodulation

Immunomodulation is poised to revolutionize the treatment of cancer, autoimmune diseases, and many other inflammation-related disorders. The immune system in these conditions can be either activated or suppressed by nanocarriers loaded with bioactive molecules. Although immunomodulation via these therapeutics has long been recognized, and a broad range of nanocarriers have been designed to accommodate varied usages, less studies have focused on the effects of nanomaterial physicochemical properties on immune responses, especially the immunity altered by nanocarrier materials alone. Conclusions are sometimes seemly inconsistent due to the complexities of nanomaterials and the immune system. An in-depth understanding of the nanocarrier-induced immune responses is essential for clinical applications. In this review, we summarize recent studies of the immune responses influenced by nanomaterial physicochemical properties with an emphasis on the intrinsic features of nanomaterials that modulate the innate and adaptive immunities. We then provide our perspectives on the design of nanomaterials for immunomodulation.

Cefixime-Containing Silica Nanoseeds Coated by a Hybrid PVA-Gold Network with a Cys-Arg Dipeptide Conjugation: Enhanced Antimicrobial and Drug Release Properties

Therapeutic nano-bioconjugates (TNBCs) as an advanced class of drug delivery systems have attracted much attention due to more efficacy than the individual medications. Hence, in this study, a novel anti-infection TNBC system is designed based on highly porous silica nanoparticles, gold nanoparticles (AuNPs), and hybridized polyvinyl alcohol (PVA) for the efficient delivery of cefixime (CFM). Furthermore, a conjugation of cysteine-arginine (CR) dipeptide is made onto the surfaces for the enhancement of cell adhesion. Concisely, the AuNPs incorporated inside the PVA network play the key role in the controlled release process triggered by localized surface plasmon resonance (LSPR) heating. The drug content of the CFM-containing cargo (named as CFM@SiO₂/PVA/Au-CR) and related release profile have been precisely studied by the confirmed analytical methods. Eventually, confocal microscopy on the stained cells has revealed that the TNBC particles are capable of entering the Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) bacterial cells better than the individual CFM. Also, optical density experiments (OD₆₀₀) have corroborated that the prepared CFM@SiO₂/PVA/Au-CR TNBC includes a high antimicrobial effect on K. pneumoniae and E. coli cells with (93.0 ± 1.5) % and (86.8 ± 1.0) % success rates, respectively, whereas the same dosage of the individual CFM has shown a lower effect on the cell growth rate. Also, estimation of minimum inhibitory/bactericidal concentrations (MIC/MBC) confirmed the enhanced antibacterial property of the CFM through the presented delivery method. Overall, this product is suggested to be clinically administrated instead of the individual CFM due to its high efficacy and containing lower dosage of the antibiotic drug.

Bioscaffold Stiffness Mediates Aerosolized Nanoparticle Uptake in Lung Epithelial Cells

In this study, highly porous, ultrasoft polymeric mats mimicking human tissues were formed from novel polyurethane soft dendritic colloids (PU SDCs). PU SDCs have a unique fibrillar morphology controlled by antisolvent precipitation. When filtered from suspension, PU SDCs form mechanically robust nonwoven mats. The stiffness of the SDC mats can be tuned for physiological relevance. The unique physiochemical characteristics of the PU SDC particles dictate the mechanical properties resulting in tunable elastic moduli ranging from 200 to 800 kPa. The human lung A549 cells cultured on both stiff and soft PU SDC membranes were found to be viable, capable of supporting the air-liquid interface (ALI) cell culture, and maintained barrier integrity. Furthermore, A549 cellular viability and uptake efficiency of aerosolized tannic acid-coated gold nanoparticles (Ta-Au) was found to depend on elastic modulus and culture conditions. Ta-Au nanoparticle uptake was twofold and fourfold greater on soft PU SDCs, when cultured at submerged and ALI conditions, respectively. The significant increase in endocytosed Ta-Au resulted in a 20% decrease in viability, and a 4-fold increase in IL-8 cytokine secretion when cultured on soft PU SDCs at ALI. Common tissue culture materials exhibit super-physiological elastic moduli, a factor found to be critical in analyzing nanomaterial cellular interactions and biological responses.

Nanoparticle-Based Drug Delivery System: The Magic Bullet for the Treatment of Chronic Pulmonary Diseases

Chronic pulmonary diseases encompass different persistent and lethal diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF), asthma, and lung cancers that affect millions of people globally. Traditional pharmacotherapeutic treatment approaches (i.e., bronchodilators, corticosteroids, chemotherapeutics, peptide-based agents, etc.) are not satisfactory to cure or impede diseases. With the advent of nanotechnology, drug delivery to an intended site is still difficult, but the nanoparticle's physicochemical properties can accomplish targeted therapeutic delivery. Based on their surface, size, density, and physical-chemical properties, nanoparticles have demonstrated enhanced pharmacokinetics of actives, achieving the spotlight in the drug delivery research field. In this review, the authors have highlighted different nanoparticle-based therapeutic delivery approaches to treat chronic pulmonary diseases along with the preparation techniques. The authors have remarked the nanosuspension delivery via nebulization and dry powder carrier is further effective in the lung delivery system since the particles released from these systems are innumerable to composite nanoparticles. The authors have also outlined the inhaled particle's toxicity, patented nanoparticle-based pulmonary formulations, and commercial pulmonary drug delivery devices (PDD) in other sections. Recently advanced formulations employing nanoparticles as therapeutic carriers for the efficient treatment of chronic pulmonary diseases are also canvassed.

Delivery of nanoparticle antigens to antigen-presenting cells: from extracellular specific targeting to intracellular responsive presentation

An appropriate delivery system can improve the immune effects of antigens against various infections or tumors. Antigen-presenting cells (APCs) are specialized to capture and process antigens in vivo, which link the innate and adaptive immune responses. Functionalization of vaccine delivery systems with targeting moieties to APCs is a promising strategy for provoking potent immune responses. Additionally, the internalization and intracellular distribution of antigens are closely related to the initiation of downstream immune responses. With a deeper understanding of the intracellular microenvironment and the mechanisms of antigen presentation, vehicles designed to respond to endogenous and external stimuli can modulate antigen processing and presentation pathways, which are critical to the types of immune response. Here, an overview of extracellular targeting delivery of antigens to APCs and intracellular stimulus-responsiveness strategies is provided, which might be helpful for the rational design of vaccine delivery systems.

Nanomaterials to target immunity

Critical advances have recently been made in the field of immunotherapy, contributing to an improved understanding of how to harness and balance the power of immune responses in the treatment of diseases such as cancer, cardiovascular disease, infectious diseases, and autoimmune diseases. Combining nanomedicine with immunotherapy provides the opportunity for customization, rational design, and targeting to minimize side effects and maximize efficacy. This review highlights current developments in the design and utilization of nano-based immunotherapy systems, including how rationally-designed nanosystems can target and modify immune cells to modulate immune responses in a therapeutic manner. We discuss the following topics: targeted immuno-engineered nanoformulations, commercial formulations, clinical applicability, challenges associated with current approaches, and future directions.

Effect of physicochemical properties on in vivo fate of nanoparticle-based cancer immunotherapies

Current advances of immunotherapy have greatly changed the way of cancer treatment. At the same time, a great number of nanoparticle-based cancer immunotherapies (NBCIs) have also been explored to elicit potent immune responses against tumors. However, few NBCIs are nearly in the clinical trial which is mainly ascribed to a lack understanding of in vivo fate of nanoparticles (NPs) for cancer immunotherapy. NPs for cancer immunotherapy mainly target the immune organs or immune cells to enable efficient antitumor immune responses. The physicochemical properties of NPs including size, shape, elasticity and surface properties directly affect their interaction with immune systems as well as their in vivo fate and therapeutic effect. Hence, systematic analysis of the physicochemical properties and their effect on in vivo fate is urgently needed. In this review, we first recapitulate the fundamentals for the in vivo fate of NBCIs including physio-anatomical features of lymphatic system and strategies to modulate immune responses. Moreover, we highlight the effect of physicochemical properties on their in vivo fate including lymph nodes (LNs) drainage, cellular uptake and intracellular transfer. Challenges and opportunities for rational design of NPs for cancer immunotherapy are also discussed in detail.

Understanding selectivity of metabolic labelling and click-targeting in multicellular environments as a route to tissue selective drug delivery

Cancer cells generally exhibit higher metabolic demands relative to that of normal tissue cells. This offers great possibilities to exploit metabolic glycoengineering in combination with bio-orthogonal chemistry reactions to achieve tumour site-targeted therapeutic delivery. This work addresses the selectivity of metabolic glycan labelling in diseased (i.e., cancer) versus normal cells grown in a multicellular environment. Dibenzocylooctyne (DBCO)-bearing acetylated-d-mannosamine (Ac4ManNDBCO) was synthesised to metabolically label three different types of cell lines originating from the human lung tissues: A549 adenocarcinomic alveolar basal epithelial cells, MeT5A non-cancerous mesothelial cells, and MRC5 non-cancerous fibroblasts. These cell lines displayed different labelling sensitivity, which trended with their doubling time in the following order: A549 ≈ MeT5A > MRC5. The higher metabolic labelling efficiency inherently led to a higher extent of specific binding and accumulation of the clickable N3-conjugated gold nanoparticles (N3-AuNps, core diameter = 30 nm) in the DBCO-glycan modified A549 and MeT5A cells, but to a less prominent effect in MRC5 cells. These findings demonstrate that relative rates of cell metabolism can be exploited using metabolic labelling to recruit nanotherapeutics whilst minimising non-specific targeting of surrounding tissues.

Loading Imatinib inside targeted nanoparticles to prevent Bronchiolitis Obliterans Syndrome

Bronchiolitis Obliterans Syndrome seriously reduces long-term survival of lung transplanted patients. Up to now there is no effective therapy once BOS is established. Nanomedicine introduces the possibility to administer drugs locally into lungs increasing drug accumulation in alveola reducing side effects. Imatinib was loaded in gold nanoparticles (GNP) functionalized with antibody against CD44 (GNP-HCIm). Lung fibroblasts (LFs) were derived from bronchoalveolar lavage of BOS patients. GNP-HCIm cytotoxicity was evaluated by MTT assay, apoptosis/necrosis and phosphorylated-cAbl (cAbl-p). Heterotopic tracheal transplantation (HTT) mouse model was used to evaluate the effect of local GNP-HCIm administration by Alzet pump. GNP-HCIm decreased LFs viability compared to Imatinib (44.4 ± 1.8% vs. 91.8 ± 3.2%, p < 0.001), inducing higher apoptosis (22.68 ± 4.3% vs. 6.43 ± 0.29; p < 0.001) and necrosis (18.65 ± 5.19%; p < 0.01). GNP-HCIm reduced cAbl-p (0.41 GNP-HCIm, 0.24 Imatinib vs. to control; p < 0.001). GNP-HCIm in HTT mouse model by Alzet pump significantly reduced tracheal lumen obliteration (p < 0.05), decreasing apoptosis (p < 0.05) and TGF-β-positive signal (p < 0.05) in surrounding tissue. GNP-HCIm treatment significantly reduced lymphocytic and neutrophil infiltration and mast cells degranulation (p < 0.05). Encapsulation of Imatinib into targeted nanoparticles could be considered a new option to inhibit the onset of allograft rejection acting on BOS specific features.

Labeling and tracking cells with gold nanoparticles

Gold nanoparticles (AuNPs) have garnered much attention as contrast agents for computerized tomography (CT) because of their facile synthesis and surface functionalization, in addition to their significant X-ray attenuation and minimal cytotoxicity. Cell labeling using AuNPs and tracking of the labeled cells using CT has become a time-efficient and cost-effective method. Actively targeted AuNPs can enhance CT contrast and sensitivity, and further reduce the radiation dosage needed during CT imaging. In this review, we summarize the state-of-the-art use of AuNPs in CT for cell tracking, including the precautionary steps necessary for their use and the difficulty in translating the process into clinical use.

Biokinetics and clearance of inhaled gold ultrasmall-in-nano architectures

Among an organism's entry portals, the respiratory tract is one of the most promising routes for non-invasive administration of therapeutics for local and systemic delivery. On the other hand, it is the subtlest to protect from environmental pollution and microbial occurrences. Here, the biokinetics, distribution, and clearance trends of gold ultrasmall-in-nano architectures administered through a single intranasal application have been quantitatively evaluated. Apart from reaching the lung parenchyma, the (bio)degradable nano-architectures are able to translocate as well to secondary organs and be almost completely excreted within 10 days. These findings further support the clinical relevance of plasmonic nanomaterials for oncology and infectious disease treatment and management. Notably, this investigation also provides crucial information regarding the associated risks as a consequence of the pulmonary delivery of nanoparticles.

Conventional and Nanotechnology Based Approaches to Combat Chronic Obstructive Pulmonary Disease: Implications for Chronic Airway Diseases

Chronic obstructive pulmonary disease (COPD) is the most prevalent obstructive lung disease worldwide characterized by decline in lung function. It is associated with airway obstruction, oxidative stress, chronic inflammation, mucus hypersecretion, and enhanced autophagy and cellular senescence. Cigarette smoke being the major risk factor, other secondary risk factors such as the exposure to air pollutants, occupational exposure to gases and fumes in developing countries, also contribute to the pathogenesis of COPD. Conventional therapeutic strategies of COPD are based on anti-oxidant and anti-inflammatory drugs. However, traditional anti-oxidant pharmacological therapies are commonly used to alleviate the impact of COPD as they have many associated repercussions such as low diffusion rate and inappropriate drug pharmacokinetics. Recent advances in nanotechnology and stem cell research have shed new light on the current treatment of chronic airway disease. This review is focused on some of the anti-oxidant therapies currently used in the treatment and management of COPD with more emphasis on the recent advances in nanotechnology-based therapeutics including stem cell and gene therapy approaches for the treatment of chronic airway disease such as COPD and asthma.

Recognition Sites for Cancer-targeting Drug Delivery Systems

BACKGROUND

Target-homing drug delivery systems are now gaining significant attention for use as novel therapeutic approaches in antitumor targeting for cancer therapy. Numerous targeted drug delivery systems have been designed to improve the targeting effects because these systems can display a range of favorable properties, thus, providing suitable characteristics for clinical applicability of anticancer drugs, such as increasing the solubility, and improving the drug distribution at target sites. The majority of these targeting systems are designed with respect to differences between cancerous and normal tissues, for instance, the low pH of tumor tissues or overexpressed receptors on tumor cell membranes. Due to the growing number of targeting possibilities, it is important to know the tumor-specific recognition strategies for designing novel, targeted, drug delivery systems. Herein, we identify and summarize literature pertaining to various recognition sites for optimizing the design of targeted drug delivery systems to augment current chemotherapeutic approaches.

OBJECTIVE

This review focuses on the identification of the recognition sites for developing targeted drug delivery systems for use in cancer therapeutics.

METHODS

We have reviewed and compiled cancer-specific recognition sites and their abnormal characteristics within tumor tissues (low pH, high glutathione, targetable receptors, etc.), tumor cells (receptor overexpression or tumor cell membrane changes) and tumor cell organelles (nuclear and endoplasmic reticular dysregulation) utilizing existing scientific literature. Moreover, we have highlighted the design of some targeted drug delivery systems that can be used as homing tools for these recognition sites.

RESULTS AND CONCLUSION

Targeted drug delivery systems are a promising therapeutic approach for tumor chemotherapy. Additional research focused on finding novel recognition sites, and subsequent development of targeting moieties for use with drug delivery systems will aid in the evaluation and clinical application of new and improved chemotherapeutics.

Lipid nanoparticles biocompatibility and cellular uptake in a 3D human lung model

Aim: Design nanostructured lipid carriers (NLC) to facilitate drug delivery to tuberculosis-infected areas, exploiting macrophage mannose receptors and assess their uptake in a 3D human lung model. Materials & methods: NLCs and mannosylated-NLCs were synthetized and characterized. Their uptake and biocompatibility were tested in a 3D human lung model. Results: The formulations have appropriate size (170–202 nm) and morphology for lung deposition. Cell membrane integrity was maintained and no significant pro-inflammatory cytokine (IL-1β, IL-8 and TNF-α) secretion or morphological changes were observed 24 h post nanoparticles exposure. NLCs and mannosylated NLCs were distributed in the apical side of the lung tissue, both in macrophages and in epithelial cells. Conclusion: NLCs are biocompatible carriers and can be used for pulmonary drug delivery.

Nanoparticle induced barrier function assessment at liquid-liquid and air-liquid interface in novel human lung epithelia cell lines

Inhalation is the most relevant entry point for nanoparticles (NPs) into the human body. To date, toxicity testing of nanomaterials in respect to oral, dermal and inhalative application is mainly based on animal experiments. The development of alternative test methods is the subject of current research. In vitro models can help to investigate mechanistic aspects, as e.g. cellular uptake or genotoxicity and might help to reduce in vivo testing. Lung cell lines are proper in vitro tools to assess NP toxicity. In respect to this, various cell models have been developed during the recent years, but often lack in a proper intact barrier function. However, besides other important in vivo criteria which are still missing like e.g. circulation, this is one basic prerequisite to come closer to the in vivo situation in certain mechanistic aspects such as particle translocation which is an important task for risk assessment of nanomaterials. Novel developed in vitro models may help to investigate the translocation of nanomaterials from the lung. We investigated the barrier function of the recently developed human lung cell lines CI-hAELVi and CI-huAEC. The cells were further exposed to CeO2 NPs and ZnO NPs, and their suitability as in vitro models for toxicological investigations was proven. The obtained data were compared with data generated with the A549 cell line. Measurement of transepithelial resistance and immunohistochemical examination of tight junctions confirmed the formation of a functional barrier for both cell lines for submerged and air-liquid cultivation. For particle exposure, hAELVi and huAEC cells showed comparable results to A549 cells without losing the barrier function. CeO2 NP exposure revealed no toxicity for all cell lines. In contrast, ZnO NPs was toxic for all cell lines at a concentration between 10-50 μg ml-1. Due to the comparable results to A549 cells CI-hAELVi and CI-huAEC offer new opportunities to investigate nanoparticle cell interactions more realistic than recent 2D cell models.

Physical and chemical profiles of nanoparticles for lymphatic targeting

Nanoparticles (NPs) have been gaining prominence as delivery vehicles for modulating immune responses to improve treatments against cancer and autoimmune diseases, enhancing tissue regeneration capacity, and potentiating vaccination efficacy. Various engineering approaches have been extensively explored to control the NP physical and chemical properties including particle size, shape, surface charge, hydrophobicity, rigidity and surface targeting ligands to modulate immune responses. This review examines a specific set of physical and chemical characteristics of NPs that enable efficient delivery targeted to secondary lymphoid tissues, specifically the lymph nodes and immune cells. A critical analysis of the structure-property-function relationship will facilitate further efforts to engineer new NPs with unique functionalities, identify novel utilities, and improve the clinical translation of NP formulations for immunotherapy.

3D organ models-Revolution in pharmacological research?

3D organ models have gained increasing attention as novel preclinical test systems and alternatives to animal testing. Over the years, many excellent in vitro tissue models have been developed. In parallel, microfluidic organ-on-a-chip tissue cultures have gained increasing interest for their ability to house several organ models on a single device and interlink these within a human-like environment. In contrast to these advancements, the development of human disease models is still in its infancy. Although major advances have recently been made, efforts still need to be intensified. Human disease models have proven valuable for their ability to closely mimic disease patterns in vitro, permitting the study of pathophysiological features and new treatment options. Although animal studies remain the gold standard for preclinical testing, they have major drawbacks such as high cost and ongoing controversy over their predictive value for several human conditions. Moreover, there is growing political and social pressure to develop alternatives to animal models, clearly promoting the search for valid, cost-efficient and easy-to-handle systems lacking interspecies-related differences. In this review, we discuss the current state of the art regarding 3D organ as well as the opportunities, limitations and future implications of their use.

SPIO Enhance the Cross-Presentation and Migration of DCs and Anionic SPIO Influence the Nanoadjuvant Effects Related to Interleukin-1β

Superparamagnetic iron oxide nanoparticles (SPIO) have been synthesized and explored for use as carriers of various nanoadjuvants via loading into dendritic cells (DCs). In our study, homogeneous and superparamagnetic nanoparticles are susceptible to internalization by DCs and SPIO-pulsed DCs showed excellent biocompatibility and capacity for ovalbumin (OVA) cross-presentation. Herein, we found that SPIO-loaded DCs can promote the maturation and migration of DCs in vitro. SPIO coated with 3-aminopropyltrimethoxysilane (APTS) and meso-2,3-dimercaptosuccinic acid (DMSA), which present positive and negative charges, respectively, were prepared. We aimed to investigate whether the surface charge of SPIO can affect the antigen cross-presentation of the DCs. Additionally, the formation of interleukin-1β (IL-1β) was examined after treatment with oppositely charged SPIO to identify the nanoadjuvants mechanism. In conclusion, our results suggest that SPIO are biocompatible and can induce the migration of DCs into secondary lymph nodes. SPIO coated with APTS (SPIO/A⁺) exhibited excellent adjuvant potentials for the promotion of antigen cross-presentation and T cell activation and surpassed that of DMSA-coated nanoparticles (SPIO/D^-). This process may be related to the secretion of IL-1β. Our study provides insights into the predictive modification of nanoadjuvants, which will be valuable in DC vaccine design and could lead to the creation of new adjuvants for applications in vaccines for humans.

Distribution of polymer-coated gold nanoparticles in a 3D lung model and indication of apoptosis after repeated exposure

AIM

The distribution and impact of aerosol-delivered gold nanoparticles (AuNPs) functionalized with a mixture of aminated-polyvinyl alcohol and amino-PEG ([polyvinyl alcohol/PEG]-NH₂) upon repeated administration onto a 3D lung model were explored.

MATERIALS & METHODS

AuNPs were aerosolized and uptake and epithelial translocation was assessed by inductively coupled plasma optical-emission spectroscopy, flow cytometry and electron microscopy. In addition, cytotoxicity, apoptosis and proinflammation were evaluated.

RESULTS

Repeated AuNP aerosolization resulted in NP accumulation in macrophages and epithelial cells. Dendritic cells demonstrated substantial NP internalization after single administration which was reduced in later time points. No cytotoxicity or proinflammation was observed but after 96 h significant apoptosis was induced by the polymer coating.

CONCLUSION

These results indicate the importance of repeated exposures in addressing potential effects of NPs.

Nanoparticles engineered to bind cellular motors for efficient delivery

Background

Dynein is a cytoskeletal molecular motor protein that transports cellular cargoes along microtubules. Biomimetic synthetic peptides designed to bind dynein have been shown to acquire dynamic properties such as cell accumulation and active intra- and inter-cellular motion through cell-to-cell contacts and projections to distant cells. On the basis of these properties dynein-binding peptides could be used to functionalize nanoparticles for drug delivery applications.

Results

Here, we show that gold nanoparticles modified with dynein-binding delivery sequences become mobile, powered by molecular motor proteins. Modified nanoparticles showed dynamic properties, such as travelling the cytosol, crossing intracellular barriers and shuttling the nuclear membrane. Furthermore, nanoparticles were transported from one cell to another through cell-to-cell contacts and quickly spread to distant cells through cell projections.

Conclusions

The capacity of these motor-bound nanoparticles to spread to many cells and increasing cellular retention, thus avoiding losses and allowing lower dosage, could make them candidate carriers for drug delivery.

Electronic supplementary material

The online version of this article (10.1186/s12951-018-0354-1) contains supplementary material, which is available to authorized users.

Towards the Identification of an In Vitro Tool for Assessing the Biological Behavior of Aerosol Supplied Nanomaterials

Nanoparticles (NP)-based inhalation systems for drug delivery can be administered in liquid form, by nebulization or using pressurized metered dose inhalers, and in solid form by means of dry powder inhalers. However, NP delivery to the lungs has many challenges including the formulation instability due to particle-particle interactions and subsequent aggregation, causing poor deposition in the small distal airways and subsequent alveolar macrophages activity, which could lead to inflammation. This work aims at providing an in vitro experimental design for investigating the correlation between the physico-chemical properties of NP, and their biological behavior, when they are used as NP-based inhalation treatments, comparing two different exposure systems. By means of an aerosol drug delivery nebulizer, human lung cells cultured at air–liquid interface (ALI) were exposed to two titanium dioxide NP (NM-100 and NM-101), obtained from the JRC repository. In parallel, ALI cultures were exposed to NP suspension by direct inoculation, i.e., by adding the NP suspensions on the apical side of the cell cultures with a pipette. The formulation stability of NP, measured as hydrodynamic size distributions, the cell viability, cell monolayer integrity, cell morphology and pro-inflammatory cytokines secretion were investigated. Our results demonstrated that the formulation stability of NM-100 and NM-101 was strongly dependent on the aggregation phenomena that occur in the conditions adopted for the biological experiments. Interestingly, comparable biological data between the two exposure methods used were observed, suggesting that the conventional exposure coupled to ALI culturing conditions offers a relevant in vitro tool for assessing the correlation between the physico-chemical properties of NP and their biological behavior, when NP are used as drug delivery systems.

Effects of engineered nanoparticles on the innate immune system

Engineered nanoparticles (NPs) have broad applications in industry and nanomedicine. When NPs enter the body, interactions with the immune system are unavoidable. The innate immune system, a non-specific first line of defense against potential threats to the host, immediately interacts with introduced NPs and generates complicated immune responses. Depending on their physicochemical properties, NPs can interact with cells and proteins to stimulate or suppress the innate immune response, and similarly activate or avoid the complement system. NPs size, shape, hydrophobicity and surface modification are the main factors that influence the interactions between NPs and the innate immune system. In this review, we will focus on recent reports about the relationship between the physicochemical properties of NPs and their innate immune response, and their applications in immunotherapy.

Assessing the Stability of Fluorescently Encoded Nanoparticles in Lysosomes by Using Complementary Methods

Nanoparticles (NPs) are promising tools in biomedical research. In vitro testing is still the first method for initial evaluation; however, NP colloidal behavior and integrity, in particular inside cells (that is, in lysosomes), are largely unknown and difficult to evaluate because of the complexity of the environment. Furthermore, while the majority of NPs are usually labeled with fluorescent dyes for tracking purposes, the effect of the lysosomal environment on the fluorophore properties, as well as the ensuing effects on data interpretation, is often only sparsely addressed. In this work, we have employed several complementary analytical methods to better understand the fate of fluorescently encoded NPs and identify potential pitfalls that may arise from focusing primary analysis on a single attribute, for example, fluorophore detection. Our study shows that in a lysosomal environment NPs can undergo significant changes resulting in dye quenching and distorted fluorescence signals.