Shape induced inhibition of phagocytosis of polymer particles

Cranberry constituents prevent SOS-mediated filamentation of uropathogenic Escherichia coli

The diameter, length, and shape of bacteria are maintained with such high fidelity that these parameters are classically used as metrics in the distinction of bacterial species. Increasing evidence indicates that bacteria transiently shift their shapes into distinctive morphologies in response to environmental changes. Elongation of bacterial length into a filamentous shape provides unique survival advantages for many bacterial species. Analysis of 42 clinical isolates of uropathogenic Escherichia coli (UPEC) revealed that filamentation to host-derived antimicrobials is a conserved phenotype. Therefore, we hypothesize that filamentation represents a conserved mechanism of pathogenic bacterial persistence that can be targeted for narrow-spectrum, anti-virulence therapies. We demonstrate that cranberries prevent SulA-mediated filamentation of UPEC. Furthermore, we identify multiple fractions of cranberries that retain anti-filamentation properties. These studies provide mechanistic insight into the clinical efficacy of cranberry for patients with recurrent urinary tract infections. Inhibition of filamentation represents a novel approach to promote bacterial pathogen susceptibility to immune and antibiotic-mediated clearance to attenuate disease.

A review on biomacromolecular ligand-directed nanoparticles: New era in macrophage targeting

Traditional drug delivery strategies often have side effects due to uneven drug distribution leading to the subtherapeutic impacts. Ligand-modified nanoparticles offer a revolutionary approach to precise drug delivery. These modified nanoparticles can potentially target macrophages, which is crucial for defense and disease progression efficiently. Out of many classes of ligands, biomacromolecular ligands emerged as potential ligands for directing these nanoparticles to macrophages due to their consecutive receptors over the macrophage surface, assisting easy internalization and thus supporting elevated efficacy and reduced toxicity. This approach could significantly improve treatment for diseases like cancer, tuberculosis, etc. by directing drugs to macrophages and reducing side effects. By leveraging nanotechnology and biomacromolecular-based ligand-directed targeting, we can achieve more precise and effective treatments, paving the way for advancements in precision medicine.

Translational nanorobotics breaking through biological membranes

In the dynamic realm of translational nanorobotics, the endeavor to develop nanorobots carrying therapeutics in rational in vivo applications necessitates a profound understanding of the biological landscape of the human body and its complexity. Within this landscape, biological membranes stand as critical barriers to the successful delivery of therapeutic cargo to the target site. Their crossing is not only a challenge for nanorobotics but also a pivotal criterion for the clinical success of therapeutic-carrying nanorobots. Nevertheless, despite their urgency, strategies for membrane crossing in translational nanorobotics remain relatively underrepresented in the scientific literature, signaling an opportunity for further research and innovation. This review focuses on nanorobots with various propulsion mechanisms from chemical and physical to hybrid mechanisms, and it identifies and describes four essential biological membranes that represent the barriers needed to be crossed in the therapeutic journey of nanorobots in in vivo applications. First is the entry point into the blood stream, which is the skin or mucosa or intravenous injection; next is the exit from the bloodstream across the endothelium to the target site; further is the entry to the cell through the plasma membrane and, finally, the escape from the lysosome, which otherwise destroys the cargo. The review also discusses design challenges inherent in translating nanorobot technologies to real-world applications and provides a critical overview of documented membrane crossings. The aim is to underscore the need for further interdisciplinary collaborations between chemists, materials scientists and chemical biologists in this vital domain of translational nanorobotics that has the potential to revolutionize the field of precision medicine.

Magnesium-ion-doped silica nanosheets as degradable drug carriers with enhanced antibacterial activity and cellular uptake

Mesoporous silica nanoparticles (MSNs) have attracted significant interest in drug delivery applications due to their good biocompatibility and high specific surface area. However, conventional MSNs typically have small pore sizes and low degradation rates, resulting in limited drug loading capacity and potential in vivo nanoparticle accumulation. This study focuses on the synthesis of novel magnesium (Mg) ion-doped silica nanoparticles (MgMSNs) using a chemical precipitation method followed by calcination. In contrast to the nanorod-shaped MSNs, the Mg ion-doped silica nanoparticles exhibited a nanosheet-shaped morphology. When the added Mg2+ concentration was 5 mM, the prepared nanosheets (5MgMSNs) showed superior antibacterial activity and increased curcumin-loading capacity compared to pure silica nanoparticles. Additionally, the natural green fluorescence of curcumin allowed for the visualization of cellular uptake, confirming the efficient internalization of 5MgMSNs by L929 cells. Notably, under acidic conditions, the release of Mg ions and the degradability of the nanoparticles were enhanced, indicating pH-responsive release behavior. Overall, these results highlight the favorable degradability and improved cellular uptake capacity of nanosheet Mg-incorporated silica nanoparticles, suggesting their potential for loading polyphenol drugs such as curcumin and achieving efficient drug release within cells.

A review of innovative design strategies: Artificial antigen presenting cells in cancer immunotherapy

Developing nanocarriers that can carry medications directly to tumors is an exciting development in cancer nanomedicine. The efficacy of this intriguing therapeutic approach is, however, compromised by intricate and immunosuppressive circumstances that arise concurrently with the onset of cancer. The artificial antigen presenting cell (aAPC), a micro or nanoparticle based device that mimics an antigen presenting cell by providing crucial signal proteins to T lymphocytes to activate them against cancer, is one cutting-edge method for cancer immunotherapy. This review delves into the critical design considerations for aAPCs, particularly focusing on particle size, shape, and the non-uniform distribution of T cell activating proteins on their surfaces. Adequate surface contact between T cells and aAPCs is essential for activation, prompting engineers to develop nano-aAPCs with microscale contact areas through techniques such as shape modification and nanoparticle clustering. Additionally, we explore recommendations for future advancements in this field.

Microfluidic Nanoparticle Separation for Precision Medicine

A deeper understanding of disease heterogeneity highlights the urgent need for precision medicine. Microfluidics, with its unique advantages, such as high adjustability, diverse material selection, low cost, high processing efficiency, and minimal sample requirements, presents an ideal platform for precision medicine applications. As nanoparticles, both of biological origin and for therapeutic purposes, become increasingly important in precision medicine, microfluidic nanoparticle separation proves particularly advantageous for handling valuable samples in personalized medicine. This technology not only enhances detection, diagnosis, monitoring, and treatment accuracy, but also reduces invasiveness in medical procedures. This review summarizes the fundamentals of microfluidic nanoparticle separation techniques for precision medicine, starting with an examination of nanoparticle properties essential for separation and the core principles that guide various microfluidic methods. It then explores passive, active, and hybrid separation techniques, detailing their principles, structures, and applications. Furthermore, the review highlights their contributions to advancements in liquid biopsy and nanomedicine. Finally, it addresses existing challenges and envisions future development spurred by emerging technologies such as advanced materials science, 3D printing, and artificial intelligence. These interdisciplinary collaborations are anticipated to propel the platformization of microfluidic separation techniques, significantly expanding their potential in precision medicine.

Physicochemical Property Effects on Immune Modulating Polymeric Nanoparticles: Potential Applications in Spinal Cord Injury

Nanoparticles (NPs) offer promising potential as therapeutic agents for inflammation-related diseases, owing to their capabilities in drug delivery and immune modulation. In preclinical studies focusing on spinal cord injury (SCI), polymeric NPs have demonstrated the ability to reprogram innate immune cells. This reprogramming results in redirecting immune cells away from the injury site, downregulating pro-inflammatory signaling, and promoting a regenerative environment post-injury. However, to fully understand the mechanisms driving these effects and maximize therapeutic efficacy, it is crucial to assess NP interactions with innate immune cells. This review examines how the physicochemical properties of polymeric NPs influence their modulation of the immune system. To achieve this, the review delves into the roles played by innate immune cells in SCI and investigates how various NP properties influence cellular interactions and subsequent immune modulation. Key NP properties such as size, surface charge, molecular weight, shape/morphology, surface functionalization, and polymer composition are thoroughly examined. Furthermore, the review establishes connections between these properties and their effects on the immunomodulatory functions of NPs. Ultimately, this review suggests that leveraging NPs and their physicochemical properties could serve as a promising therapeutic strategy for treating SCI and potentially other inflammatory diseases.

A physiologically based toxicokinetic model for microplastics and nanoplastics in mice after oral exposure and its implications for human dietary exposure assessment

Evidence of microplastics (MPs) and nanoplastics (NPs) in foods and daily-use products, along with their frequent detection in the human body, has raised concerns regarding their potential impact on human health through dietary ingestion. However, there is a lack of quantitative tools to simulate their bioaccumulation and tissue distribution following environmental exposure. To address this gap, we developed the first physiologically based toxicokinetic (PBTK) model for predicting the biodistribution of MPs and NPs in mice following oral exposure under various exposure scenarios. This novel model incorporated key kinetic mass transport processes, such as membrane permeability, albumin binding, and cellular uptake. We identified that the absorption rate in the gastrointestinal tract and fecal excretion rate constant had significant impacts on organ dosimetry. Our regression analysis indicated that the size-dependent dissociation constant and urine clearance rate constant sharply increased by a factor of 3 as NPs particle size increased to 1 µm. Finally, we developed a graphical user interface to enable interactive visualization and analysis for future applications, supporting human dietary exposure and risk assessment using available food consumption data and MPs/NPs residue data. The simulation results offer a mechanistic perspective, enhancing understanding of the internal organ dosimetry burden and health impacts from dietary exposure to MPs and NPs.

A nanotechnology driven effectual localized lung cancer targeting approaches using tyrosine kinases inhibitors: Recent progress, preclinical assessment, challenges, and future perspectives

The higher incidence and mortality rate among all populations worldwide explains the unmet solutions in the treatment of lung cancer. The evolution of targeted therapies using tyrosine kinase inhibitors (TKI) has encouraged anticancer therapies. However, on-target and off-target effects and the development of drug resistance limited the anticancer potential of such targeted biologics. The advances in nanotechnology-driven-TKI embedded carriers that offered a new path toward lung cancer treatment. It is the inhalation route of administration known for its specific, precise, and efficient drug delivery to the lungs. The development of numerous TKI-nanocarriers through inhalation is proof of TKI growth. The future scopes involve using potential lung cancer biomarkers to achieve localized active cancer-targeting strategies. The adequate knowledge of in vitro absorption models usually helps establish better in vitro - in vivo correlation/extrapolation (IVIVC/E) to successfully evaluate inhalable drugs and drug products. The advanced in vitro and ex vivo lung tissue/ organ models offered better tumor heterogeneity, etiology, and microenvironment heterogeneity. The involvement of lung cancer organoids (LCOs), human organ chip models, and genetically modified mouse models (GEMMs) has resolved the challenges associated with conventional in vitro and in vivo models. To access potential inhalation-based drugtherapies, biological barriers, drug delivery, device-based challenges, and regulatory challenges must be encountered associated with their development. A proper understanding of material toxicity, size-based particle deposition at active disease sites, mucociliary clearance, phagocytosis, and the presence of enzymes and surfactants are required to achieve successful inhalational drug delivery (IDD). This article summarizes the future of lung cancer therapy using targeted drug-mediated inhalation using TKI.

Light-Driven Green-Fabricated Artificial Intelligence-Enabled Micro/Nanorobots for Multimodal Phototherapeutic Management of Bladder Cancer

Combination therapy based on precise phototherapies combined with immune modulation provides successful antitumor effects. In this study, a combination therapy is designed based on phototactic, photosynthetic, and phototherapeutic Chlamydomonas Reinhardtii (CHL)-glycol chitosan (GCS)-polypyrrole (PPy) nanoparticle (NP)-enhanced immunity combined with the tumor microenvironment turnover of cytotoxic T cells and M1/M2 macrophages, which is based on photothermal GCS-PPy NPs decorated onto the phototactic and photosynthetic CHL. Phototherapy based on CHL-GCS-PPy NPs alleviates hypoxia and modulates the tumor immune microenvironment, which induces tumor cell death. In particular, the precise antitumor immune response and potent immune memory induced by combining self-navigated phototherapies significantly alleviate the progression of bladder cancer in C57BL/6 mice and effectively inhibit bladder tumor growth. Furthermore, they also potentially prevent tumor recurrence, which provides a promising therapeutic strategy for clinical tumor therapy.

Smart nanocarriers for enzyme-activated prodrug therapy

Exogenous enzyme-activated prodrug therapy (EPT) is a potential cancer treatment strategy that delivers non-human enzymes into or on the surface of the cell and subsequently converts a non-toxic prodrug into an active cytotoxic substance at a specific location and time. The development of several pharmacological pairs based on EPT has been the focus of anticancer research for more than three decades. Numerous of these pharmacological pairs have progressed to clinical trials, and a few have achieved application in specific cancer therapies. The current review highlights the potential of enzyme-activated prodrug therapy as a promising anticancer treatment. Different microbial, plant, or viral enzymes and their corresponding prodrugs that advanced to clinical trials have been listed. Additionally, we discuss new trends in the field of enzyme-activated prodrug nanocarriers, including nanobubbles combined with ultrasound (NB/US), mesoscopic-sized polyion complex vesicles (PICsomes), nanoparticles, and extracellular vesicles (EVs), with special emphasis on smart stimuli-triggered drug release, hybrid nanocarriers, and the main application of nanotechnology in improving prodrugs.

Why does a cell function? New arguments in favor of quantum effects

In this study, the complexities of intracellular processes have been analyzed, including DNA folding, alternative splicing, mitochondrial function, and enzyme transport in lysosomes. Based on a previously proposed hypothesis (Levinthal's generalized paradox), a conclusion is made that all abovementioned processes cannot be realized with sufficient accuracy and in a realistic timeframe within the framework of classical physics. It is unclear why the cell functions at all. For the cell to function, its internal environment must be highly structured. In this regard, the cell shares similarities with computational devices (computers). In this study, quantum models of interactions between biologically important molecules were constructed, taking into account the long-range effects. One significant aspect of these models is the special role of the phase of the wavefunction, which serves as a controlling parameter. Experiments have been proposed that may confirm or refute these models.

Cuboids Prevail When Unraveling the Influence of Microchip Geometry on Macrophage Interactions and Metabolic Responses

Drug delivery advances rely on using nano- and microsized carriers to transfer therapeutic molecules, although challenges persist in increasing the availability of new and even approved pharmaceutical products. Particle shape, a critical determinant in how these carriers distribute within the body after administration, raises opportunities of using, for instance, micrometer-sized nonspherical particles for vascular targeting and thereby creating new prospects for precise drug delivery to specific targeted areas. The versatility of polycrystalline silicon microfabrication allows for significant variation in the size and shape of microchips, and so, in the current work, photolithography was employed to create differently shaped polysilicon microchips, including cuboids, cubes, bars, and cylinders, to explore the influence of particle shape on cellular interactions. These microchips with different shapes and lateral dimensions, accounting for surface areas in the range of ca. 15 to 120 μm2 and corresponding total volumes of 0.4 to 27 μm3, serve as ideal models for investigating their interactions with macrophages with diameters of ca. 20 μm. Side-scattering imaging flow cytometry was employed for studying the interaction of label-free prepared microchips with RAW 264.7 macrophages. Using a dose of 3 microchips per cell, results show that cuboids exhibit the highest cellular association (ca. 25%) and uptake (ca. 20%), suggesting their potential as efficient carriers for targeted drug delivery to macrophages. Conversely, similarly sized cylinders and bar-shaped microchips exhibit lower uptakes of about 8% and about 6%, respectively, indicating potential benefits in evading macrophage recognition. On average, 1-1.5 microchips were internalized, and ca. 1 microchip was surface-bound per cell, with cuboids showing the higher values overall. Macrophages respond to microchips by increasing their metabolic activity and releasing low levels of intracellular enzymes, indicating reduced toxicity. Interestingly, increasing the particle dose enhances macrophage metabolic activity without significantly affecting enzyme release.

Antibacterial Nanoplatelets via Crystallization-Driven Self-Assembly of Poly(l-lactide)-Based Block Copolymers

Membrane-active antimicrobial materials are promising substances to fight antimicrobial resistance. Herein, crystallization-driven self-assembly (CDSA) is employed for the preparation of nanoparticles with different morphologies, and their bioactivity is explored. Block copolymers (BCPs) featuring a crystallizable and antimicrobial block were synthesized using a combination of ring-opening and photoiniferter RAFT polymerizations. Subsequently formed nanostructures formed by CDSA could not be deprotected without degradation of the structures. CDSA of deprotected BCPs yielded 2D diamond-shaped nanoplatelets in MeOH, while spherical nanostructures were observed for assembly in water. Platelets exhibited improved antibacterial capabilities against two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) compared to their spherical counterparts. The absence of hemolytic activity leads to the excellent selectivity of platelets. A mechanism based on membrane permeabilization was confirmed via dye-leakage assays. This study emphasized the impact of the shape of nanostructures on their interaction with bacterial cells and how a controlled assembly can improve bioactivity.

Exploring the influence of silicon oxide microchips shape on cellular uptake using imaging flow cytometry

Nano- and micro-carriers of therapeutic molecules offer numerous advantages for drug delivery, and the shape of these particles plays a vital role in their biodistribution and their interaction with cells. However, analysing how microparticles are taken up by cells presents methodological challenges. Qualitative methods like microscopy provide detailed imaging but are time-consuming, whereas quantitative methods such as flow cytometry enable high-throughput analysis but struggle to differentiate between internalised and surface-bound particles. Instead, imaging flow cytometry combines the best of both worlds, offering high-resolution imaging with the efficiency of flow cytometry, allowing for quantitative analysis at the single-cell level. This study focuses on fluorescently labelled silicon oxide microchips of various morphologies but related surface areas and volumes: rectangular cuboids and apex-truncated square pyramid microchips fabricated using photolithography techniques, offering a reliable basis for comparison with the more commonly studied spherical particles. Imaging flow cytometry was utilised to evaluate the effect of particle shape on cellular uptake using RAW 264.7 cells and revealed phagocytosis of particles with all shapes. Increasing the particle dose enhanced the uptake, while macrophage stimulation had minimal effect. Using a ratio particle:cell of 10:1 cuboids and spheres showed an uptake rate of approximately 50%, in terms of the percentage of cells with internalised particles, and the average number of particles taken up per cell ranging from about 1-1.5 particle/cell for all the different shapes. This study indicates how differently shaped micro-carriers offer insights into particle uptake variations, demonstrating the potential of non-spherical micro-carriers for precise drug delivery applications.

Application of PPAR Ligands and Nanoparticle Technology in Metabolic Steatohepatitis Treatment

Metabolic dysfunction-associated steatotic liver disease/steatohepatitis (MASLD/MASH) is a major disease worldwide whose effective treatment is challenging. Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear receptor superfamily and function as ligand-activated transcription factors. To date, three distinct subtypes of PPARs have been characterized: PPARα, PPARβ/δ, and PPARγ. PPARα and PPARγ are crucial regulators of lipid metabolism that modulate the transcription of genes involved in fatty acid (FA), bile acid, and cholesterol metabolism. Many PPAR agonists, including natural (FAs, eicosanoids, and phospholipids) and synthetic (fibrate, thiazolidinedione, glitazar, and elafibranor) agonists, have been developed. Furthermore, recent advancements in nanoparticles (NPs) have led to the development of new strategies for MASLD/MASH therapy. This review discusses the applications of specific cell-targeted NPs and highlights the potential of PPARα- and PPARγ-targeted NP drug delivery systems for MASLD/MASH treatment.

Directed assembly of small binary clusters of magnetizable ellipsoids

We report the effect of shape anisotropy and material properties on the directed assembly of binary suspensions composed of magnetizable ellipsoids. In a Monte Carlo simulation, we implement the ellipsoid-dipole model to calculate the pairwise dipolar interaction energy as a function of position and orientation. The analysis explores dilute suspensions of paramagnetic and diamagnetic ellipsoids with different aspect ratios in a superparamagnetic medium. We analyze the local order of binary structures as a function of particle aspect ratio, medium permeability, and dipolar interaction strength. Our results show that local order and symmetry are tunable under the influence of a uniform magnetic field when one component of the structure is dilute with respect to the other. The simulation results match previously reported experiments on the directed assembly of binary suspension of spheres. Additionally, we report the conditions on particle aspect ratios and medium properties for various structures with rotational symmetries, as well as open and enclosed structures under the influence of a uniform magnetic field.

Macrophage based drug delivery: Key challenges and strategies

As a natural immune cell and antigen presenting cell, macrophages have been studied and engineered to treat human diseases. Macrophages are well-suited for use as drug carriers because of their biological characteristics, such as excellent biocompatibility, long circulation, intrinsic inflammatory homing and phagocytosis. Meanwhile, macrophages' uniquely high plasticity and easy re-education polarization facilitates their use as part of efficacious therapeutics for the treatment of inflammatory diseases or tumors. Although recent studies have demonstrated promising advances in macrophage-based drug delivery, several challenges currently hinder further improvement of therapeutic effect and clinical application. This article focuses on the main challenges of utilizing macrophage-based drug delivery, from the selection of macrophage sources, drug loading, and maintenance of macrophage phenotypes, to drug migration and release at target sites. In addition, corresponding strategies and insights related to these challenges are described. Finally, we also provide perspective on shortcomings on the road to clinical translation and production.

The road ahead to successful BBB opening and drug-delivery with focused ultrasound

This review delves into the innovative technology of Blood-Brain Barrier (BBB) opening with low-intensity focused ultrasound in combination with microbubbles (LIFU-MB), a promising therapeutic modality aimed at enhancing drug delivery to the central nervous system (CNS). The BBB's selective permeability, while crucial for neuroprotection, significantly hampers the efficacy of pharmacological treatments for CNS disorders. LIFU-MB emerges as a non-invasive and localized method to transiently increase BBB permeability, facilitating the delivery of therapeutic molecules. Here, we review the procedural stages of LIFU-MB interventions, including planning and preparation, sonication, evaluation, and delivery, highlighting the technological diversity and methodological challenges encountered in current clinical applications. With an emphasis on safety and efficacy, we discuss the crucial aspects of ultrasound delivery, microbubble administration, acoustic feedback monitoring and assessment of BBB permeability. Finally, we explore the critical choices for effective BBB opening with LIFU-MB, focusing on selecting therapeutic agents, optimizing delivery methods, and timing for delivery. Overcoming existing barriers to integrate this technology into clinical practice could potentially revolutionize CNS drug delivery and treatment paradigms in the near future.

Immunological Effects of Diesel Particles in a Murine Model of Healthy Mice

Introduction: Exposure to environmental pollutants such as diesel exhaust particles (DEP) increases the risk of respiratory disease exacerbation. However, the possible effects of these particles on the general population remain poorly understood. The present study aimed to assess the immunomodulatory and inflammatory effects of the inhalation of DEP in a model of healthy mice undergoing short-, mid- and long-term exposure. Materials and Methods: BALB/c ByJ mice were randomly divided into five experimental groups. The control group received three intranasal instillations of saline over 8 days while the other four groups received intranasal instillations of 150 µg of DEP 3 days per week for 8, 17, 26, and 53 days. Lung function assessment and flow cytometry were performed. Results: In lung tissue, intranasal exposure to DEP decreased total monocytes (p < 0.015 in all groups). At 26 days, a reduction in inflammatory monocytes and an increase in resident monocytes were observed, p = 0.001 and 0.0001, respectively. Eosinophils and neutrophils decreased at 26 days (p = 0.017 and p = 0.041, respectively). The intranasal challenges of DEP increased the total population of dendritic cells (DC) at 26 and 53 days (p = 0.017 and p = 0.022, respectively) and decreased the total and alveolar populations of macrophages (p < 0.003 for all groups compared to control), while interstitial macrophage populations increased over the time period (p = 0.0001 for all groups compared to control). Conclusions: Continuous DEP exposure triggers immune mechanisms that predispose healthy individuals to a pro-inflammatory and hyper-reactive microenvironment. This mouse model provides evidence of the capacity of DEP to increase DC, interstitial macrophages, and resident monocytes.

Immunofilaments Are Well Tolerated after Local or Systemic Administration in Mice

The invention of nanosized biomaterials has paved the way for novel therapeutics that can manipulate cells on a nanoscale. Nanosized immunofilaments (IFs) are synthetic filamentous polymers consisting out of polyisocyanopeptides, which have been recently established as a powerful platform to activate specific immune cells in vivo such that they raise an antitumor immune response. However, toxicological effects or immunogenicity toward the IFs have not yet been investigated. In this study, we evaluated potential toxic or immunogenic effects in C57BL/6 mice upon intravenous or subcutaneous injection of nonfunctionalized IFs or immunostimulatory IFs over 30 days. We here present a detailed analysis of the gross pathology, hematological parameters, blood biochemistry, histology, and antibody-response against the IF backbone. Our results demonstrate that IFs do not induce severe acute or chronic toxicity in mice. After 30 days, we only found elevated IgG-titers in intravenously injected but not subcutaneously injected mice. In summary, we demonstrate that IFs can be administered into a living organism without adverse side effects, thereby establishing the safety of IFs as a therapeutic intervention.

Nanoparticle-neutrophils interactions for autoimmune regulation

Neutrophils play an essential role as 'first responders' in the immune response, necessitating many immune-modulating capabilities. Chronic, unresolved inflammation is heavily implicated in the progression and tissue-degrading effects of autoimmune disease. Neutrophils modulate disease pathogenesis by interacting with the inflammatory and autoreactive cells through effector functions, including signaling, degranulation, and neutrophil extracellular traps (NETs) release. Since the current gold standard systemic glucocorticoid administration has many drawbacks and side effects, targeting neutrophils in autoimmunity provides a new approach to developing therapeutics. Nanoparticles enable targeting of specific cell types and controlled release of a loaded drug cargo. Thus, leveraging nanoparticle properties and interactions with neutrophils provides an exciting new direction toward novel therapies for autoimmune diseases. Additionally, recent work has utilized neutrophil properties to design novel targeted particles for delivery into previously inaccessible areas. Here, we outline nanoparticle-based strategies to modulate neutrophil activity in autoimmunity, including various nanoparticle formulations and neutrophil-derived targeting.

Enzyme-loaded rod-like microgel shapes: a step towards the creation of shape-specific microreactors for blood detoxification purposes

Rapid removal of toxic substances is crucial to restore the normal functions of our body and ensure survival. Due to their high substrate specificity and catalytic efficiency, enzymes are unique candidates to deplete toxic compounds. While enzymes display several limitations including low stability and high immunogenicity, these can be overcome by entrapping them in a diverse range of carriers. The resulting micro/nanoreactors shield the enzymes from their surroundings, preventing their misfolding or denaturation thus allowing them to conduct their function. The micro/nanoreactors must circulate in the blood stream for extended periods of time to ensure complete depletion of the toxic agents. Surprisingly, while it is widely acknowledged that non-spherical carriers exhibit longer residence time in the bloodstream than their spherical counterparts, so far, all the reported micro/nanoreactors have been assembled with a spherical architecture. Herein, we address this important issue by pioneering the first shape-specific microreactors. We use UV-assisted punching to create rod-like microgel shapes with dimensions of 8 μm × 1 μm × 2 μm and demonstrate their biocompatibility by conducting hemolysis and cell viability assays with a macrophage and an endothelial cell line. Upon encapsulation of the model enzyme β-lactamase, the successful fabrication of rod-shaped microreactors is demonstrated by their ability to convert the yellow nitrocefin substrate into its hydrolyzed product.

Manipulation of Macrophage Uptake by Controlling the Aspect Ratio of Graft Copolymer Micelles

Nanostructures of drug carriers play a crucial role in nanomedicine due to their ability to influence drug delivery. There is yet no clear consensus regarding the optimal size and shape (e.g., aspect ratio) of nanoparticles for minimizing macrophage uptake, given the difficulties in controlling the shape and size of nanoparticles while maintaining identical surface properties. Here, we employed graft copolymer self-assembly to prepare polymer micelles with aspect ratios ranging from 1.0 (spherical) to 10.8 (cylindrical) and closely matched interfacial properties. Notably, our findings emphasize that cylindrical micelles with an aspect ratio of 2.4 are the least susceptible to macrophage uptake compared with both their longer counterparts and spherical micelles. This reduced uptake of the short cylindrical micelles results in a 3.3-fold increase in blood circulation time compared with their spherical counterparts. Controlling the aspect ratio of nanoparticles is crucial for improving drug delivery efficacy through better nanoparticle design.

Shape Matters: Impact of Mesoporous Silica Nanoparticle Morphology on Anti-Tumor Efficacy

A nanoparticle's shape is a critical determinant of its biological interactions and therapeutic effectiveness. This study investigates the influence of shape on the performance of mesoporous silica nanoparticles (MSNs) in anticancer therapy. MSNs with spherical, rod-like, and hexagonal-plate-like shapes were synthesized, with particle sizes of around 240 nm, and their other surface properties were characterized. The drug loading capacities of the three shapes were controlled to be 47.46%, 49.41%, and 46.65%, respectively. The effects of shape on the release behaviors, cellular uptake mechanisms, and pharmacological behaviors of MSNs were systematically investigated. Through a series of in vitro studies using 4T1 cells and in vivo evaluations in 4T1 tumor-bearing mice, the release kinetics, cellular behaviors, pharmacological effects, circulation profiles, and therapeutic efficacy of MSNs were comprehensively assessed. Notably, hexagonal-plate-shaped MSNs loaded with PTX exhibited a prolonged circulation time (t1/2 = 13.59 ± 0.96 h), which was approximately 1.3 times that of spherical MSNs (t1/2 = 10.16 ± 0.38 h) and 1.5 times that of rod-shaped MSNs (t1/2 = 8.76 ± 1.37 h). This research underscores the significance of nanoparticles' shapes in dictating their biological interactions and therapeutic outcomes, providing valuable insights for the rational design of targeted drug delivery systems in cancer therapy.

Nanoparticles Targeting Lymph Nodes for Cancer Immunotherapy: Strategies and Influencing Factors

Immunotherapy has emerged as a potent strategy in cancer treatment, with many approved drugs and modalities in the development stages. Despite its promise, immunotherapy is not without its limitations, including side effects and suboptimal efficacy. Using nanoparticles (NPs) as delivery vehicles to target immunotherapy to lymph nodes (LNs) can improve the efficacy of immunotherapy drugs and reduce side effects in patients. In this context, this paper reviews the development of LN-targeted immunotherapeutic NP strategies, the mechanisms of NP transport during LN targeting, and their related biosafety risks. NP targeting of LNs involves either passive targeting, influenced by NP physical properties, or active targeting, facilitated by affinity ligands on NP surfaces, while alternative methods, such as intranodal injection and high endothelial venule (HEV) targeting, have uncertain clinical applicability and require further research and validation. LN targeting of NPs for immunotherapy can reduce side effects and increase biocompatibility, but risks such as toxicity, organ accumulation, and oxidative stress remain, although strategies such as biodegradable biomacromolecules, polyethylene glycol (PEG) coating, and impurity addition can mitigate these risks. Additionally, this work concludes with a future-oriented discussion, offering critical insights into the field.

Features of Anisotropic Drug Delivery Systems

Natural materials are anisotropic. Delivery systems occurring in nature, such as viruses, blood cells, pollen, and many others, do have anisotropy, while delivery systems made artificially are mostly isotropic. There is apparent complexity in engineering anisotropic particles or capsules with micron and submicron sizes. Nevertheless, some promising examples of how to fabricate particles with anisotropic shapes or having anisotropic chemical and/or physical properties are developed. Anisotropy of particles, once they face biological systems, influences their behavior. Internalization by the cells, flow in the bloodstream, biodistribution over organs and tissues, directed release, and toxicity of particles regardless of the same chemistry are all reported to be factors of anisotropy of delivery systems. Here, the current methods are reviewed to introduce anisotropy to particles or capsules, including loading with various therapeutic cargo, variable physical properties primarily by anisotropic magnetic properties, controlling directional motion, and making Janus particles. The advantages of combining different anisotropy in one entity for delivery and common problems and limitations for fabrication are under discussion.

Peptide nanovaccine in melanoma immunotherapy

Melanoma is an especially fatal neoplasm resistant to traditional treatment. The advancement of novel therapeutical approaches has gained attention in recent years by shedding light on the molecular mechanisms of melanoma tumorigenesis and their powerful interplay with the immune system. The presence of many mutations in melanoma cells results in the production of a varied array of antigens. These antigens can be recognized by the immune system, thereby enabling it to distinguish between tumors and healthy cells. In the context of peptide cancer vaccines, generally, they are designed based on tumor antigens that stimulate immunity through antigen-presenting cells (APCs). As naked peptides often have low potential in eliciting a desirable immune reaction, immunization with such compounds usually necessitates adjuvants and nanocarriers. Actually, nanoparticles (NPs) can provide a robust immune response to peptide-based melanoma vaccines. They improve the directing of peptide vaccines to APCs and induce the secretion of cytokines to get maximum immune response. This review provides an overview of the current knowledge of the utilization of nanotechnology in peptide vaccines emphasizing melanoma, as well as highlights the significance of physicochemical properties in determining the fate of these nanovaccines in vivo, including their drainage to lymph nodes, cellular uptake, and influence on immune responses.

FRET-Sensing of Multivalent Protein Binding at the Interface of Biomimetic Microparticles Functionalized with Fluorescent Glycolipids

Cell adhesion is a central process in cellular communication and regulation. Adhesion sites are triggered by specific ligand-receptor interactions inducing the clustering of both partners at the contact point. Investigating cell adhesion using microscopy techniques requires targeted fluorescent particles with a signal sensitive to the clustering of receptors and ligands at the interface. Herein, we report on simple cell or bacterial mimics, based on liquid microparticles made of lipiodol functionalized with custom-designed fluorescent lipids. These lipids are targeted toward lectins or biotin membrane receptors, and the resulting particles can be specifically identified and internalized by cells, as demonstrated by their phagocytosis in primary murine bone marrow-derived macrophages. We also evidence the possibility to sense the binding of a multivalent lectin, concanavalin A, in solution by monitoring the energy transfer between two matching fluorescent lipids on the surface of the particles. We anticipate that these liquid particle-based sensors, which are able to report via Förster resonance energy transfer (FRET) on the movement of ligands on their interface upon protein binding, will provide a useful tool to study receptor binding and cooperation during adhesion processes such as phagocytosis.

Nanomaterials in Medicine: Understanding Cellular Uptake, Localization, and Retention for Enhanced Disease Diagnosis and Therapy

Nanomaterials (NMs) have emerged as promising tools for disease diagnosis and therapy due to their unique physicochemical properties. To maximize the effectiveness and design of NMs-based medical applications, it is essential to comprehend the complex mechanisms of cellular uptake, subcellular localization, and cellular retention. This review illuminates the various pathways that NMs take to get from the extracellular environment to certain intracellular compartments by investigating the various mechanisms that underlie their interaction with cells. The cellular uptake of NMs involves complex interactions with cell membranes, encompassing endocytosis, phagocytosis, and other active transport mechanisms. Unique uptake patterns across cell types highlight the necessity for customized NMs designs. After internalization, NMs move through a variety of intracellular routes that affect where they are located subcellularly. Understanding these pathways is pivotal for enhancing the targeted delivery of therapeutic agents and imaging probes. Furthermore, the cellular retention of NMs plays a critical role in sustained therapeutic efficacy and long-term imaging capabilities. Factors influencing cellular retention include nanoparticle size, surface chemistry, and the cellular microenvironment. Strategies for prolonging cellular retention are discussed, including surface modifications and encapsulation techniques. In conclusion, a comprehensive understanding of the mechanisms governing cellular uptake, subcellular localization, and cellular retention of NMs is essential for advancing their application in disease diagnosis and therapy. This review provides insights into the intricate interplay between NMs and biological systems, offering a foundation for the rational design of next-generation nanomedicines.

Design of Liquid Formulation Based on F127-Loaded Natural Dimeric Flavonoids as a New Perspective Treatment for Leishmaniasis

Infectious and Parasitic Diseases (IPD) remain a challenge for medicine due to several interconnected reasons, such as antimicrobial resistance (AMR). American tegumentary leishmaniasis (ATL) is an overlooked IPD causing persistent skin ulcers that are challenging to heal, resulting in disfiguring scars. Moreover, it has the potential to extend from the skin to the mucous membranes of the nose, mouth, and throat in both humans and various animals. Given the limited effectiveness and AMR of current drugs, the exploration of new substances has emerged as a promising alternative for ATL treatment. Arrabidaea brachypoda (DC). Bureau is a native Brazilian plant rich in dimeric flavonoids, including Brachydin (BRA), which displays antimicrobial activity, but still little has been explored regarding the development of therapeutic formulations. In this work, we present the design of a low-cost liquid formulation based on the use of Pluronic F127 for encapsulation of high BRA concentration (LF-B500). The characterization techniques revealed that BRA-loaded F127 micelles are well-stabilized in an unusual worm-like form. The in vitro cytotoxicity assay demonstrated that LF-B500 was non-toxic to macrophages but efficient in the inactivation of forms of Leishmania amazonensis promastigotes with IC50 of 16.06 µg/mL. The results demonstrated that LF-B500 opened a new perspective on the use of liquid formulation-based natural products for ATL treatment.

Protein and peptide-based renal targeted drug delivery systems

Renal diseases have become an increasingly concerned public health problem in the world. Kidney-targeted drug delivery has profound transformative potential on increasing renal efficacy and reducing extra-renal toxicity. Protein and peptide-based kidney targeted drug delivery systems have garnered more and more attention due to its controllable synthesis, high biocompatibility and low immunogenicity. At the same time, the targeting methods based on protein/peptide are also abundant, including passive renal targeting based on macromolecular protein and active targeting mediated by renal targeting peptide. Here, we review the application and the drug loading strategy of different proteins or peptides in targeted drug delivery, including the ferritin family, albumin, low molecular weight protein (LMWP), different peptide sequence and antibodies. In addition, we summarized the factors influencing passive and active targeting in drug delivery system, the main receptors related to active targeting in different kidney diseases, and a variety of nano forms of proteins based on the controllable synthesis of proteins.

Nano-Formulations for Pulmonary Delivery: Past, Present, and Future Perspectives

With the development of nanotechnology and confronting the problems of traditional pharmaceutical formulations in treating lung diseases, inhalable nano-formulations have attracted interest. Inhalable nano-formulations for treating lung diseases allow for precise pulmonary drug delivery, overcoming physiological barriers, improving aerosol lung deposition rates, and increasing drug bioavailability. They are expected to solve the difficulties faced in treating lung diseases. However, limited success has been recorded in the industrialization translation of inhalable nano-formulations. Only one relevant product has been approved by the FDA to date, suggesting that there are still many issues to be resolved in the clinical application of inhalable nano-formulations. These systems are characterized by a dependence on inhalation devices, while the adaptability of device formulation is still inconclusive, which is the most important issue impeding translational research. In this review, we categorized various inhalable nano-formulations, summarized the advantages of inhalable nano-formulations over conventional inhalation formulations, and listed the inhalable nano-formulations undergoing clinical studies. We focused on the influence of inhalation devices on nano-formulations and analyzed their adaptability. After extensive analysis of the drug delivery mechanisms, technical processes, and limitations of different inhalation devices, we concluded that vibrating mesh nebulizers might be most suitable for delivering inhalable nano-formulations, and related examples were introduced to validate our view. Finally, we presented the challenges and outlook for future development. We anticipate providing an informative reference for the field.

A detailed insight of the tumor targeting using nanocarrier drug delivery system

Human struggle against the deadly disease conditions is continued since ages. The contribution of science and technology in fighting against these diseases cannot be ignored exclusively due to the invention of novel procedure and products, extending their size ranges from micro to nano. Recently nanotechnology has been gaining more consideration for its ability to diagnose and treat different cancers. Different nanoparticles have been used to evade the issues related with conservative anticancer delivery systems, including their nonspecificity, adverse effects and burst release. These nanocarriers including, solid lipid nanoparticles (SLNs), liposomes, nano lipid carriers (NLCs), nano micelles, nanocomposites, polymeric and magnetic nanocarriers, have brought revolutions in antitumor drug delivery. Nanocarriers improved the therapeutic efficacy of anticancer drugs with better accumulation at the specific site with sustained release, improved bioavailability and apoptosis of the cancer cells while bypassing the normal cells. In this review, the cancer targeting techniques and surface modification on nanoparticles are discussed briefly with possible challenges and opportunities. It can be concluded that understanding the role of nanomedicine in tumor treatment is significant, and therefore, the modern progressions in this arena is essential to be considered for a prosperous today and an affluent future of tumor patients.

Inhaled RNA drugs to treat lung diseases: Disease-related cells and nano-bio interactions

In recent years, RNA-based therapies have gained much attention as biomedicines due to their remarkable therapeutic effects with high specificity and potency. Lung diseases offer a variety of currently undruggable but attractive targets that could potentially be treated with RNA drugs. Inhaled RNA drugs for the treatment of lung diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, and acute respiratory distress syndrome, have attracted more and more attention. A variety of novel nanoformulations have been designed and attempted for the delivery of RNA drugs to the lung via inhalation. However, the delivery of RNA drugs via inhalation poses several challenges. It includes protection of the stability of RNA molecules, overcoming biological barriers such as mucus and cell membrane to the delivery of RNA molecules to the targeted cytoplasm, escaping endosomal entrapment, and circumventing unwanted immune response etc. To address these challenges, ongoing researches focus on developing innovative nanoparticles to enhance the stability of RNA molecules, improve cellular targeting, enhance cellular uptake and endosomal escape to achieve precise delivery of RNA drugs to the intended lung cells while avoiding unwanted nano-bio interactions and off-target effects. The present review first addresses the pathologic hallmarks of different lung diseases, disease-related cell types in the lung, and promising therapeutic targets in these lung cells. Subsequently we highlight the importance of the nano-bio interactions in the lung that need to be addressed to realize disease-related cell-specific delivery of inhaled RNA drugs. This is followed by a review on the physical and chemical characteristics of inhaled nanoformulations that influence the nano-bio interactions with a focus on surface functionalization. Finally, the challenges in the development of inhaled nanomedicines and some key aspects that need to be considered in the development of future inhaled RNA drugs are discussed.

Harnessing biomaterial architecture to drive anticancer innate immunity

Immunomodulation is a powerful therapeutic approach that harnesses the body's own immune system and reprograms it to treat diseases, such as cancer. Innate immunity is key in mobilizing the rest of the immune system to respond to disease and is thus an attractive target for immunomodulation. Biomaterials have widely been employed as vehicles to deliver immunomodulatory therapeutic cargo to immune cells and raise robust antitumor immunity. However, it is key to consider the design of biomaterial chemical and physical structure, as it has direct impacts on innate immune activation and antigen presentation to stimulate downstream adaptive immunity. Herein, we highlight the widespread importance of structure-driven biomaterial design for the delivery of immunomodulatory cargo to innate immune cells. The incorporation of precise structural elements can be harnessed to improve delivery kinetics, uptake, and the targeting of biomaterials into innate immune cells, and enhance immune activation against cancer through temporal and spatial processing of cargo to overcome the immunosuppressive tumor microenvironment. Structural design of immunomodulatory biomaterials will profoundly improve the efficacy of current cancer immunotherapies by maximizing the impact of the innate immune system and thus has far-reaching translational potential against other diseases.

Advancements in Macrophage-Targeted Drug Delivery for Effective Disease Management

Macrophages play a crucial role in tissue homeostasis and the innate immune system. They perform essential functions such as presenting antigens, regulating cytokines, and responding to inflammation. However, in diseases like cancer, cardiovascular disorders, and autoimmune conditions, macrophages undergo aberrant polarization, which disrupts tissue regulation and impairs their normal behavior. To address these challenges, there has been growing interest in developing customized targeted drug delivery systems specifically designed for macrophage-related functions in different anatomical locations. Nanomedicine, utilizing nanoscale drug systems, offers numerous advantages including improved stability, enhanced pharmacokinetics, controlled release kinetics, and precise temporal drug delivery. These advantages hold significant promise in achieving heightened therapeutic efficacy, specificity, and reduced side effects in drug delivery and treatment approaches. This review aims to explore the roles of macrophages in major diseases and present an overview of current strategies employed in targeted drug delivery to macrophages. Additionally, this article critically evaluates the design of macrophage-targeted delivery systems, highlighting limitations and discussing prospects in this rapidly evolving field. By assessing the strengths and weaknesses of existing approaches, we can identify areas for improvement and refinement in macrophage-targeted drug delivery.

Pulmonary endothelium-targeted nanoassembly of indomethacin and superoxide dismutase relieves lung inflammation

Lung inflammation is an essential inducer of various diseases and is closely related to pulmonary-endothelium dysfunction. Herein, we propose a pulmonary endothelium-targeted codelivery system of anti-inflammatory indomethacin (IND) and antioxidant superoxide dismutase (SOD) by assembling the biopharmaceutical SOD onto the "vector" of rod-like pure IND crystals, followed by coating with anti-ICAM-1 antibody (Ab) for targeting endothelial cells. The codelivery system has a 237 nm diameter in length and extremely high drug loading of 39% IND and 2.3% SOD. Pharmacokinetics and biodistribution studies demonstrate the extended blood circulation and the strong pulmonary accumulation of the system after intravenous injection in the lipopolysaccharide (LPS)-induced inflammatory murine model. Particularly, the system allows a robust capacity to target pulmonary endothelium mostly due to the rod-shape and Ab coating effect. In vitro, the preparation shows the synergistic anti-inflammatory and antioxidant effects in LPS-activated endothelial cells. In vivo, the preparation exhibits superior pharmacodynamic efficacy revealed by significantly downregulating the inflammatory/oxidative stress markers, such as TNF-α, IL-6, COX-2, and reactive oxygen species (ROS), in the lungs. In conclusion, the codelivery system based on rod-like pure crystals could well target the pulmonary endothelium and effectively alleviate lung inflammation. The study offers a promising approach to combat pulmonary endothelium-associated diseases.

Harnessing inhaled nanoparticles to overcome the pulmonary barrier for respiratory disease therapy

The lack of effective treatments for pulmonary diseases presents a significant global health burden, primarily due to the challenges posed by the pulmonary barrier that hinders drug delivery to the lungs. Inhaled nanomedicines, with their capacity for localized and precise drug delivery to specific pulmonary pathologies through the respiratory route, hold tremendous promise as a solution to these challenges. Nevertheless, the realization of efficient and safe pulmonary drug delivery remains fraught with multifaceted challenges. This review summarizes the delivery barriers associated with major pulmonary diseases, the physicochemical properties and drug formulations affecting these barriers, and emphasizes the design advantages and functional integration of nanomedicine in overcoming pulmonary barriers for efficient and safe local drug delivery. The review also deliberates on established nanocarriers and explores drug formulation strategies rooted in these nanocarriers, thereby furnishing essential guidance for the rational design and implementation of pulmonary nanotherapeutics. Finally, this review cast a forward-looking perspective, contemplating the clinical prospects and challenges inherent in the application of inhaled nanomedicines for respiratory diseases.

Current research trends of nanomedicines

Owing to the inherent shortcomings of traditional therapeutic drugs in terms of inadequate therapeutic efficacy and toxicity in clinical treatment, nanomedicine designs have received widespread attention with significantly improved efficacy and reduced non-target side effects. Nanomedicines hold tremendous theranostic potential for treating, monitoring, diagnosing, and controlling various diseases and are attracting an unfathomable amount of input of research resources. Against the backdrop of an exponentially growing number of publications, it is imperative to help the audience get a panorama image of the research activities in the field of nanomedicines. Herein, this review elaborates on the development trends of nanomedicines, emerging nanocarriers, in vivo fate and safety of nanomedicines, and their extensive applications. Moreover, the potential challenges and the obstacles hindering the clinical translation of nanomedicines are also discussed. The elaboration on various aspects of the research trends of nanomedicines may help enlighten the readers and set the route for future endeavors.

Iron Oxide Nanoparticles with Supramolecular Ureido-Pyrimidinone Coating for Antimicrobial Peptide Delivery

Antimicrobial peptides (AMPs) can kill bacteria by disrupting their cytoplasmic membrane, which reduces the tendency of antibacterial resistance compared to conventional antibiotics. Their possible toxicity to human cells, however, limits their applicability. The combination of magnetically controlled drug delivery and supramolecular engineering can help to reduce the dosage of AMPs, control the delivery, and improve their cytocompatibility. Lasioglossin III (LL) is a natural AMP form bee venom that is highly antimicrobial. Here, superparamagnetic iron oxide nanoparticles (IONs) with a supramolecular ureido-pyrimidinone (UPy) coating were investigated as a drug carrier for LL for a controlled delivery to a specific target. Binding to IONs can improve the antimicrobial activity of the peptide. Different transmission electron microscopy (TEM) techniques showed that the particles have a crystalline iron oxide core with a UPy shell and UPy fibers. Cytocompatibility and internalization experiments were carried out with two different cell types, phagocytic and nonphagocytic cells. The drug carrier system showed good cytocompatibility (>70%) with human kidney cells (HK-2) and concentration-dependent toxicity to macrophagic cells (THP-1). The particles were internalized by both cell types, giving them the potential for effective delivery of AMPs into mammalian cells. By self-assembly, the UPy-coated nanoparticles can bind UPy-functionalized LL (UPy-LL) highly efficiently (99%), leading to a drug loading of 0.68 g g-1. The binding of UPy-LL on the supramolecular nanoparticle system increased its antimicrobial activity against E. coli (MIC 3.53 µM to 1.77 µM) and improved its cytocompatible dosage for HK-2 cells from 5.40 µM to 10.6 µM. The system showed higher cytotoxicity (5.4 µM) to the macrophages. The high drug loading, efficient binding, enhanced antimicrobial behavior, and reduced cytotoxicity makes ION@UPy-NH2 an interesting drug carrier for AMPs. The combination with superparamagnetic IONs allows potential magnetically controlled drug delivery and reduced drug amount of the system to address intracellular infections or improve cancer treatment.

The interplay between PEGylated nanoparticles and blood immune system

During the last two decades, an increasing number of reports have pointed out that the immunogenicity of polyethylene glycol (PEG) may trigger accelerated blood clearance (ABC) and hypersensitivity reaction (HSR) to PEGylated nanoparticles, which could make PEG modification counterproductive. These phenomena would be detrimental to the efficacy of the load and even life-threatening to patients. Consequently, further elucidation of the interplay between PEGylated nanoparticles and the blood immune system will be beneficial to developing and applying related formulations. Many groups have worked to unveil the relevance of structural factors, dosing schedule, and other factors to the ABC phenomenon and hypersensitivity reaction. Interestingly, the results of some reports seem to be difficult to interpret or contradict with other reports. In this review, we summarize the physiological mechanisms of PEG-specific immune response. Moreover, we speculate on the potential relationship between the induction phase and the effectuation phase to explain the divergent results in published reports. In addition, the role of nanoparticle-associated factors is discussed based on the classification of the action phase. This review may help researchers to develop PEGylated nanoparticles to avoid unfavorable immune responses based on the underlying mechanism.

Selective organ targeting nanoparticles: from design to clinical translation

Targeting nanoparticle is a very promising therapeutic approach that can precisely target specific sites to treat diseases. Research on nanoscale drug delivery systems has made great progress in the past few years, making targeting nanoparticles a promising prospect. However, selective targeting nanoparticles designed for specific organs still face several challenges, one of which is the unknown fate of nanoparticles in vivo. This review starts with the in vivo journey of nanoparticles and describes the biological barriers and some targeting strategies for nanoparticles to target specific organs. Then, through the collection of literature in recent years, the design of selective targeting nanoparticles for various organs is illustrated, which provides a reference strategy for people to study the design of selective organ targeting nanoparticles. Ultimately, the prospect and challenge of selective organ targeting nanoparticles are discussed by collecting the data of clinical trials and marketed drugs.

CXCL17 Attenuates Diesel Exhaust Emissions Exposure-Induced Lung Damage by Regulating Macrophage Function

Exposure to diesel exhaust emissions (DEE) is strongly linked to innate immune injury and lung injury, but the role of macrophage chemoattractant CXCL17 in the lung damage caused by DEE exposure remains unclear. In this study, whole-body plethysmography (WBP), inflammatory cell differential count, and histopathological analysis were performed to assess respiratory parameters, airway inflammation, and airway injury in C57BL/6 male mice exposed to DEE for 3 months. qRT-PCR, IHC (immunohistochemistry), and ELISA were performed to measure the CXCL17 expression in airway epithelium or BALF (bronchoalveolar lavage fluid) following DEE/Diesel exhaust particle (DEP) exposure. Respiratory parameters, airway inflammation, and airway injury were assessed in CXCL17-overexpressing mice through adeno-associated virus vector Type 5 (AAV5) infection. Additionally, an in vitro THP-1 and HBE co-culture system was constructed. Transwell assay was carried out to evaluate the effect of rh-CXCL17 (recombinant human protein-CXCL17) on THP-1 cell migration. Flow cytometry and qRT-PCR were conducted to assess the impacts of rh-CXCL17 on apoptosis and inflammation/remodeling of HBE cells. We found that the mice exposed to DEE showed abnormal respiratory parameters, accompanied by airway injury and remodeling (ciliary injury in airway epithelium, airway smooth muscle hyperplasia, and increased collagen deposition). Carbon content in airway macrophages (CCAM), but not the number of macrophages in BALF, increased significantly. CXCL17 expression significantly decreased in mice airways and HBE after DEE/DEP exposure. AAV5-CXCL17 enhanced macrophage recruitment and clearance of DEE in the lungs of mice, and it improved respiratory parameters, airway injury, and airway remodeling. In the THP-1/HBE co-culture system, rh-CXCL17 increased THP-1 cell migration while attenuating HBE cell apoptosis and inflammation/remodeling. Therefore, CXCL17 might attenuate DEE-induced lung damage by recruiting and activating pulmonary macrophages, which is expected to be a novel therapeutic target for DEE-associated lung diseases.

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

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

Membrane backtracking at the maximum capacity of nondigestible antigen phagocytosis in macrophages

The zipper model has been dominantly used to describe the driving mechanism of the engulfment process and its specific identification of antigens during phagocytosis in macrophages. However, the abilities and limitations of the zipper model, capturing the process as an irreversible reaction, have not been examined yet under the critical conditions of engulfment capacity. Here, we demonstrated the phagocytic behavior of macrophages after reaching the maximum engulfment capacity by tracking the progression of their membrane extension during engulfment using IgG-coated nondigestible polystyrene beads and glass microneedles. The results showed that, after macrophages reached their maximum engulfment capacity, they induced membrane backtracking (the reverse phenomenon of engulfment) in both polystyrene beads and glass microneedles, regardless of the difference in the shape of these antigens. We evaluated the correlation of engulfment in simultaneous stimulations of two IgG-coated microneedles and found that each microneedle was regurgitated by the macrophage independently of the advancement or backtracking of membranes on the other microneedle. Moreover, assessing the total engulfment capacity determined by the maximum amount the macrophage was capable of engulfing when imposing each antigen geometry showed that the capacity increased as the attached antigen areas increased. These results indicate that the mechanism of engulfment should imply the following: 1) macrophages have a backtracking function to recover their phagocytic activity after reaching maximal engulfment limit, 2) both phagocytosis and backtracking are local phenomena of the macrophage membrane that operates independently, and 3) the maximum engulfment capacity is determined not only by mere local cell membrane capacity but also by the whole-cell volume increase during simultaneous phagocytosis of multiple antigens by the single macrophages. Thus, the phagocytic activity may entail a hidden backtracking function, adding to the conventionally known irreversible zipper-like ligand-receptor binding mechanism during membrane progression to recover the macrophages that are saturated from engulfing targets beyond their capacity.

Encapsulation of β-NGF in injectable microrods for localized delivery accelerates endochondral fracture repair

Introduction: Currently, there are no non-surgical FDA-approved biological approaches to accelerate fracture repair. Injectable therapies designed to stimulate bone healing represent an exciting alternative to surgically implanted biologics, however, the translation of effective osteoinductive therapies remains challenging due to the need for safe and effective drug delivery. Hydrogel-based microparticle platforms may be a clinically relevant solution to create controlled and localized drug delivery to treat bone fractures. Here, we describe poly (ethylene glycol) dimethacrylate (PEGDMA)-based microparticles, in the shape of microrods, loaded with beta nerve growth factor (β-NGF) for the purpose of promoting fracture repair. Methods: Herein, PEGDMA microrods were fabricated through photolithography. PEGDMA microrods were loaded with β-NGF and in vitro release was examined. Subsequently, bioactivity assays were evaluated in vitro using the TF-1 tyrosine receptor kinase A (Trk-A) expressing cell line. Finally, in vivo studies using our well-established murine tibia fracture model were performed and a single injection of the β-NGF loaded PEGDMA microrods, non-loaded PEGDMA microrods, or soluble β-NGF was administered to assess the extent of fracture healing using Micro-computed tomography (µCT) and histomorphometry. Results: In vitro release studies showed there is significant retention of protein within the polymer matrix over 168 hours through physiochemical interactions. Bioactivity of protein post-loading was confirmed with the TF-1 cell line. In vivo studies using our murine tibia fracture model show that PEGDMA microrods injected at the site of fracture remained adjacent to the callus for over 7 days. Importantly, a single injection of β-NGF loaded PEGDMA microrods resulted in improved fracture healing as indicated by a significant increase in the percent bone in the fracture callus, trabecular connective density, and bone mineral density relative to soluble β-NGF control indicating improved drug retention within the tissue. The concomitant decrease in cartilage fraction supports our prior work showing that β-NGF promotes endochondral conversion of cartilage to bone to accelerate healing. Discussion: We demonstrate a novel and translational method wherein β-NGF can be encapsulated within PEGDMA microrods for local delivery and that β-NGF bioactivity is maintained resulting in improved bone fracture repair.

The shape anisotropy of magnetic nanoparticles: an approach to cell-type selective and enhanced internalization

The effects of the shape anisotropy of nanoparticles on cellular uptake is still poorly understood due to challenges in the synthesis of anisotropic magnetic nanoparticles of the same composition. Here, we design and synthesize spherical magnetic nanoparticles and their anisotropic assemblies, namely magnetic nanochains (length ∼800 nm). Then, nanoparticle shape anisotropy is investigated on urothelial cells in vitro. Although both shapes of nanomaterials reveal biocompatibility, we havefound significant differences in the extent of their intracellular accumulation. Contrary to spherical particles, anisotropic nanochains preferentially accumulate in cancer cells as confirmed by inductively coupled plasma (ICP) analysis, indicating that control of the nanoparticle shape geometry governs cell-type-selective intracellular uptake and accumulation.

Nonspherical ultrasound microbubbles

Surface tension provides microbubbles (MB) with a perfect spherical shape. Here, we demonstrate that MB can be engineered to be nonspherical, endowing them with unique features for biomedical applications. Anisotropic MB were generated via one-dimensionally stretching spherical poly(butyl cyanoacrylate) MB above their glass transition temperature. Compared to their spherical counterparts, nonspherical polymeric MB displayed superior performance in multiple ways, including i) increased margination behavior in blood vessel-like flow chambers, ii) reduced macrophage uptake in vitro, iii) prolonged circulation time in vivo, and iv) enhanced blood-brain barrier (BBB) permeation in vivo upon combination with transcranial focused ultrasound (FUS). Our studies identify shape as a design parameter in the MB landscape, and they provide a rational and robust framework for further exploring the application of anisotropic MB for ultrasound-enhanced drug delivery and imaging applications.

Virus-like particle-based nanocarriers as an emerging platform for drug delivery

New nanocarrier technologies are emerging, and they have great potential for improving drug delivery, targeting efficiency, and bioavailability. Virus-like particles (VLPs) are natural nanoparticles from animal and plant viruses and bacteriophages. Hence, VLPs present several great advantages, such as morphological uniformity, biocompatibility, reduced toxicity, and easy functionalisation. VLPs can deliver many active ingredients to the target tissue and have great potential as a nanocarrier to overcome the limitations associated with other nanoparticles. This review will focus primarily on the construction and applications of VLPs, particularly as a novel nanocarrier to deliver active ingredients. Herein, the main methods for the construction, purification, and characterisation of VLPs, as well as various VLP-based materials used in delivery systems are summarised. The biological distribution of VLPs in drug delivery, phagocyte-mediated clearance, and toxicity are also discussed.