Overcoming Nanoparticle-Mediated Complement Activation by Surface PEG Pairing

Albumin Nanoparticle-Based Drug Delivery Systems

Nanoparticle-based systems are extensively investigated for drug delivery. Among others, with superior biocompatibility and enhanced targeting capacity, albumin appears to be a promising carrier for drug delivery. Albumin nanoparticles are highly favored in many disease therapies, as they have the proper chemical groups for modification, cell-binding sites for cell adhesion, and affinity to protein drugs for nanocomplex generation. Herein, this review summarizes the recent fabrication techniques, modification strategies, and application of albumin nanoparticles. We first discuss various albumin nanoparticle fabrication methods, from both pros and cons. Then, we provide a comprehensive introduction to the modification section, including organic albumin nanoparticles, metal albumin nanoparticles, inorganic albumin nanoparticles, and albumin nanoparticle-based hybrids. We finally bring further perspectives on albumin nanoparticles used for various critical diseases.

Research Advances of Lipid Nanoparticles in the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a common type of gastrointestinal tract (GIT) cancer and poses an enormous threat to human health. Current strategies for metastatic colorectal cancer (mCRC) therapy primarily focus on chemotherapy, targeted therapy, immunotherapy, and radiotherapy; however, their adverse reactions and drug resistance limit their clinical application. Advances in nanotechnology have rendered lipid nanoparticles (LNPs) a promising nanomaterial-based drug delivery system for CRC therapy. LNPs can adapt to the biological characteristics of CRC by modifying their formulation, enabling the selective delivery of drugs to cancer tissues. They overcome the limitations of traditional therapies, such as poor water solubility, nonspecific biodistribution, and limited bioavailability. Herein, we review the composition and targeting strategies of LNPs for CRC therapy. Subsequently, the applications of these nanoparticles in CRC treatment including drug delivery, thermal therapy, and nucleic acid-based gene therapy are summarized with examples provided. The last section provides a glimpse into the advantages, current limitations, and prospects of LNPs in the treatment of CRC.

Sulfoxide-containing polymers conjugated prodrug micelles with enhanced anticancer activity and reduced intestinal toxicity

Poly(ethylene glycol) (PEG) is widely utilized as a hydrophilic coating to extend the circulation time and improve the tumor accumulation of polymeric micelles. Nonetheless, PEGylated micelles often activate complement proteins, leading to accelerated blood clearance and negatively impacting drug efficacy and safety. Here, we have crafted amphiphilic block copolymers that merge hydrophilic sulfoxide-containing polymers (psulfoxides) with the hydrophobic drug 7-ethyl-10-hydroxylcamptothecin (SN38) into drug-conjugate micelles. Our findings show that the specific variant, PMSEA-PSN38 micelles, remarkably reduce protein fouling, prolong blood circulation, and improve intratumoral accumulation, culminating in significantly increased anti-cancer efficacy compared with PEG-PSN38 counterpart. Additionally, PMSEA-PSN38 micelles effectively inhibit complement activation, mitigate leukocyte uptake, and attenuate hyperactivation of inflammatory cells, diminishing their ability to stimulate tumor metastasis and cause inflammation. As a result, PMSEA-PSN38 micelles show exceptional promise in the realm of anti-metastasis and significantly abate SN38-induced intestinal toxicity. This study underscores the promising role of psulfoxides as viable PEG substitutes in the design of polymeric micelles for efficacious anti-cancer drug delivery.

Mechanisms and Barriers in Nanomedicine: Progress in the Field and Future Directions

In recent years, steady progress has been made in synthesizing and characterizing engineered nanoparticles, resulting in several approved drugs and multiple promising candidates in clinical trials. Regulatory agencies such as the Food and Drug Administration and the European Medicines Agency released important guidance documents facilitating nanoparticle-based drug product development, particularly in the context of liposomes and lipid-based carriers. Even with the progress achieved, it is clear that many barriers must still be overcome to accelerate translation into the clinic. At the recent conference workshop "Mechanisms and Barriers in Nanomedicine" in May 2023 in Colorado, U.S.A., leading experts discussed the formulation, physiological, immunological, regulatory, clinical, and educational barriers. This position paper invites open, unrestricted, nonproprietary discussion among senior faculty, young investigators, and students to trigger ideas and concepts to move the field forward.

Mass-Spectrometric Identification of Proteins and Pathways Responsible for Fouling on Poly(ethylene glycol) Methacrylate Polymer Brushes

Prevention of fouling from proteins in blood plasma attracts significant efforts, and great progress is made in identifying surface coatings that display antifouling properties. In particular, poly(ethylene glycol) (PEG) is widely used and dense PEG-like cylindrical brushes of poly[oligo(ethylene glycol) methacrylate] (poly(OEGMA)) can drastically reduce blood plasma fouling. Herein, a comprehensive study of the variation of blood plasma fouling on this surface, including the analysis of the composition of protein deposits on poly(OEGMA) coatings after contact with blood plasma from many different donors, is reported. Correlation between the plasma fouling behavior and protein deposit composition points to the activation of the complement system as the main culprit of dramatically increased and accelerated deposition of blood plasma proteins on this type of antifouling coating, specifically through the classical pathway. These findings are consistent with observations on PEGylated drug carriers and highlight the importance of understanding the potential interactions between antifouling coatings and their environment.

Bioinspired zwitterionic triblock copolymers designed for colloidal drug delivery: 2 - Biological evaluation

In this work, poly(lactide) nanoparticles were equipped with a bioinspired coating layer based on poly[2-(methacryloyloxy)ethyl phosphorylcholine] and then evaluated when administered to the lungs and after intravenous injection. Compared to the plain counterparts, the chosen zwitterionic polymer shell prevented the coated colloidal formulation from aggregation and conditioned it for lower cytotoxicity, protein adsorption, complement activation and phagocytic cell uptake. Consequently, no interference with the biophysical function of the lung surfactant system could be detected accompanied by negligible protein and cell influx into the bronchoalveolar space after intratracheal administration. When injected into the central compartment, the coated formulation showed a prolonged circulation half-life and a delayed biodistribution to the liver. Taken together, colloidal drug delivery vehicles would clearly benefit from the investigated poly[2-(methacryloyloxy)ethyl phosphorylcholine]-based polymer coatings.

Functionalized nanoparticles to deliver nucleic acids to the brain for the treatment of Alzheimer's disease

Brain-targeted gene delivery across the blood-brain barrier (BBB) is a significant challenge in the 21st century for the healthcare sector, particularly in developing an effective treatment strategy against Alzheimer's disease (AD). The Internal architecture of the brain capillary endothelium restricts bio-actives entry into the brain. Additionally, therapy with nucleic acids faces challenges like vulnerability to degradation by nucleases and potential immune responses. Functionalized nanocarrier-based gene delivery approaches have resulted in safe and effective platforms. These nanoparticles (NPs) have demonstrated efficacy in protecting nucleic acids from degradation, enhancing transport across the BBB, increasing bioavailability, prolonging circulation time, and regulating gene expression of key proteins involved in AD pathology. We provided a detailed review of several nanocarriers and targeting ligands such as cell-penetrating peptides (CPPs), endogenous proteins, and antibodies. The utilization of functionalized NPs extends beyond a singular system, serving as a versatile platform for customization in related neurodegenerative diseases. Only a few numbers of bioactive regimens can go through the BBB. Thus, exploring functionalized NPs for brain-targeted gene delivery is of utmost necessity. Currently, genes are considered high therapeutic potential molecules for altering any disease-causing gene. Through surface modification, nanoparticulate systems can be tailored to address various diseases by replacing the target-specific molecule on their surface. This review article presents several nanoparticulate delivery systems, such as lipid NPs, polymeric micelles, exosomes, and polymeric NPs, for nucleic acids delivery to the brain and the functionalization strategies explored in AD research.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

Therapeutic Peptides Are Preferentially Solubilized in Specific Microenvironments within PEG-PLGA Polymer Nanoparticles

Polymeric nanoparticles are a highly promising drug delivery formulation. However, a lack of understanding of the molecular mechanisms that underlie their drug solubilization and controlled release capabilities has hindered the efficient clinical translation of such technologies. Polyethylene glycol-poly(lactic-co-glycolic) acid (PEG-PLGA) nanoparticles have been widely studied as cancer drug delivery vehicles. In this letter, we use unbiased coarse-grained molecular dynamics simulations to model the self-assembly of a PEG-PLGA nanoparticle and its solubulization of the anticancer peptide, EEK, with good agreement with previously reported experimental structural data. We applied unsupervised machine learning techniques to quantify the conformations that polymers adopt at various locations within the nanoparticle. We find that the local microenvironments formed by the various polymer conformations promote preferential EEK solubilization within specific regions of the NP. This demonstrates that these microenvironments are key in controlling drug storage locations within nanoparticles, supporting the rational design of nanoparticles for therapeutic applications.

In Vitro and In Vivo Evaluation of the Pathology and Safety Aspects of Three- and Four-Way Junction RNA Nanoparticles

RNA therapeutics has advanced into the third milestone in pharmaceutical drug development, following chemical and protein therapeutics. RNA itself can serve as therapeutics, carriers, regulators, or substrates in drug development. Due to RNA's motile, dynamic, and deformable properties, RNA nanoparticles have demonstrated spontaneous targeting and accumulation in cancer vasculature and fast excretion through the kidney glomerulus to urine to prevent possible interactions with healthy organs. Furthermore, the negatively charged phosphate backbone of RNA results in general repulsion from negatively charged lipid cell membranes for further avoidance of vital organs. Thus, RNA nanoparticles can spontaneously enrich tumor vasculature and efficiently enter tumor cells via specific targeting, while those not entering the tumor tissue will clear from the body quickly. These favorable parameters have led to the expectation that RNA has low or little toxicity. RNA nanoparticles have been well characterized for their anticancer efficacy; however, little detail on RNA nanoparticle pathology and safety is known. Here, we report the in vitro and in vivo assessment of the pathology and safety aspects of different RNA nanoparticles including RNA three-way junction (3WJ) harboring 2'-F modified pyrimidine, folic acid, and Survivin siRNA, as well as the RNA four-way junction (4WJ) harboring 2'-F modified pyrimidine and 24 copies of SN38. Both animal models and patient serum were investigated. In vitro studies include hemolysis, platelet aggregation, complement activation, plasma coagulation, and interferon induction. In vivo studies include hematoxylin and eosin (H&E) staining, hematological and biochemical analysis as the serum profiling, and animal organ weight study. No significant toxicity, side effect, or immune responses were detected during the extensive safety evaluations of RNA nanoparticles. These results further complement previous cancer inhibition studies and demonstrate RNA nanoparticles as an effective and safe drug delivery vehicle for future clinical translations.

Cell Membrane Biomimetic Nano-Delivery Systems for Cancer Therapy

Nano-delivery systems have demonstrated great promise in the therapy of cancer. However, the therapeutic efficacy of conventional nanomedicines is hindered by the clearance of the blood circulation system and the physiological barriers surrounding the tumor. Inspired by the unique capabilities of cells within the body, such as immune evasion, prolonged circulation, and tumor-targeting, there has been a growing interest in developing cell membrane biomimetic nanomedicine delivery systems. Cell membrane modification on nanoparticle surfaces can prolong circulation time, activate tumor-targeting, and ultimately improve the efficacy of cancer treatment. It shows excellent development potential. This review will focus on the advancements in various cell membrane nano-drug delivery systems for cancer therapy and the obstacles encountered during clinical implementation. It is hoped that such discussions will inspire the development of cell membrane biomimetic nanomedical systems.

A shift of paradigm: From avoiding nanoparticular complement activation in the field of nanomedicines to its exploitation in the context of vaccine development

The complement system plays a central role in our innate immunity to fight pathogenic microorganisms, foreign and altered cells, or any modified molecule. Consequences of complement activation include cell lysis, release of histamines, and opsonization of foreign structures in preparation for phagocytosis. Because nanoparticles interact with the immune system in various ways and can massively activate the complement system due to their virus-mimetic size and foreign texture, detrimental side effects have been described after administration like pro-inflammatory responses, inflammation, mild to severe anaphylactic crisis and potentially complement activated-related pseudoallergy (CARPA). Therefore, application of nanotherapeutics has sometimes been observed with restraint, and avoiding or even suppressing complement activation has been of utmost priority. In contrast, in the field of vaccine development, particularly protein-based immunogens that are attached to the surface of nanoparticles, may profit from complement activation regarding breadth and potency of immune response. Improved transport to the regional lymph nodes, enhanced antigen uptake and presentation, as well as beneficial effects on immune cells like B-, T- and follicular dendritic cells may be exploited by strategic nanoparticle design aimed to activate the complement system. However, a shift of paradigm regarding complement activation by nanoparticular vaccines can only be achieved if these beneficial effects are accurately elicited and overshooting effects avoided.

Activation of the complement system by nanoparticles and strategies for complement inhibition

The complement system is a multicomponent and multifunctional arm of the innate immune system. Complement contributes to non-specific host defence and maintains homeostasis through multifaceted processes and pathways, including crosstalk with the adaptive immune system, the contact (coagulation) and the kinin systems, and alarmin high-mobility group box 1. Complement is also present intracellularly, orchestrating a wide range of housekeeping and physiological processes in both immune and nonimmune cells, thus showing its more sophisticated roles beyond innate immunity, but its roles are still controversial. Particulate drug carriers and nanopharmaceuticals typically present architectures and surface patterns that trigger complement system in different ways, resulting in both beneficial and adverse responses depending on the extent of complement activation and regulation as well as pathophysiological circumstances. Here we consider the role of complement system and complement regulations in host defence and evaluate the mechanisms by which nanoparticles trigger and modulate complement responses. Effective strategies for the prevention of nanoparticle-mediated complement activation are introduced and discussed.

Cholesterol removal improves performance of a model biomimetic system to co-deliver a photothermal agent and a STING agonist for cancer immunotherapy

Biological membranes often play important functional roles in biomimetic drug delivery systems. We discover that the circulation time and targeting capability of biological membrane coated nanovehicles can be significantly improved by reducing cholesterol level in the coating membrane. A proof-of-concept system using cholesterol-reduced and PD-1-overexpressed T cell membrane to deliver a photothermal agent and a STING agonist is thus fabricated. Comparing with normal membrane, this engineered membrane increases tumor accumulation by ~2-fold. In a melanoma model in male mice, tumors are eliminated with no recurrence in >80% mice after intravenous injection and laser irradiation; while in a colon cancer model in male mice, ~40% mice are cured without laser irradiation. Data suggest that the engineered membranes escape immune surveillance to avoid blood clearance while keeping functional surface molecules exposed. In summary, we develop a simple, effective, safe and widely-applicable biological membrane modification strategy. This "subtractive" strategy displays some advantages and is worth further development.

From Bench to Bedside: Implications of Lipid Nanoparticle Carrier Reactogenicity for Advancing Nucleic Acid Therapeutics

In biomedical applications, nanomaterial-based delivery vehicles, such as lipid nanoparticles, have emerged as promising instruments for improving the solubility, stability, and encapsulation of various payloads. This article provides a formal review focusing on the reactogenicity of empty lipid nanoparticles used as delivery vehicles, specifically emphasizing their application in mRNA-based therapies. Reactogenicity refers to the adverse immune responses triggered by xenobiotics, including administered lipid nanoparticles, which can lead to undesirable therapeutic outcomes. The key components of lipid nanoparticles, which include ionizable lipids and PEG-lipids, have been identified as significant contributors to their reactogenicity. Therefore, understanding the relationship between lipid nanoparticles, their structural constituents, cytokine production, and resultant reactogenic outcomes is essential to ensure the safe and effective application of lipid nanoparticles in mRNA-based therapies. Although efforts have been made to minimize these adverse reactions, further research and standardization are imperative. By closely monitoring cytokine profiles and assessing reactogenic manifestations through preclinical and clinical studies, researchers can gain valuable insights into the reactogenic effects of lipid nanoparticles and develop strategies to mitigate undesirable reactions. This comprehensive review underscores the importance of investigating lipid nanoparticle reactogenicity and its implications for the development of mRNA-lipid nanoparticle therapeutics in various applications beyond vaccine development.

Cleavable-Branched Polymer-Modified Liposomes Reduce Accelerated Blood Clearance and Enhance Photothermal Therapy

In recent years, cationic liposomes have been successfully used as delivery platforms for mRNA vaccines. Poly(ethylene glycol) (PEG)-lipid derivatives are widely used to enhance the stability and reduce the toxicity of cationic liposomes. However, these derivatives are often immunogenic, triggering the rise of anti-PEG antibodies. Understanding the role and impact of PEG-lipid derivatives on PEGylated cationic liposomes is key to solving the PEG dilemma. In this study, we designed linear, branched, and cleavable-branched cationic liposomes modified with PEG-lipid derivatives and investigated the effect of the liposome-induced accelerated blood clearance (ABC) phenomenon on photothermal therapy. Our study indicated that the linear PEG-lipid derivatives mediated the effect of photothermal therapy by stimulating splenic marginal zone (MZ) B cells to secrete anti-PEG antibodies and increasing the level of IgM expression in the follicular region of the spleen. However, the cleavable-branched and branched PEG-lipid derivatives did not activate the complement system and avoided the ABC phenomenon by inducing noticeably lower levels of anti-PEG antibodies. The cleavable-branched PEGylated cationic liposomes improved the effect of photothermal therapy by reversing the charge on the liposome surface. This detailed study of PEG-lipid derivatives contributes to the further development and clinical application of PEGylated cationic liposomes.

Advances in Enhancing Hemocompatibility of Hemodialysis Hollow-Fiber Membranes

Hemodialysis, the most common modality of renal replacement therapy, is critically required to remove uremic toxins from the blood of patients with end-stage kidney disease. However, the chronic inflammation, oxidative stress as well as thrombosis induced by the long-term contact of hemoincompatible hollow-fiber membranes (HFMs) contribute to the increase in cardiovascular diseases and mortality in this patient population. This review first retrospectively analyzes the current clinical and laboratory research progress in improving the hemocompatibility of HFMs. Details on different HFMs currently in clinical use and their design are described. Subsequently, we elaborate on the adverse interactions between blood and HFMs, involving protein adsorption, platelet adhesion and activation, and the activation of immune and coagulation systems, and the focus is on how to improve the hemocompatibility of HFMs in these aspects. Finally, challenges and future perspectives for improving the hemocompatibility of HFMs are also discussed to promote the development and clinical application of new hemocompatible HFMs.

Graphical Abstract

Assessment of core-shell nanoparticles surface structure heterogeneity by SAXS contrast variation and ab initio modeling

For the biomedical applications of nanoparticles, the study of their structure is a major step towards understanding the mechanisms of their interaction with biological environment. Detailed structural analysis of particles' surface is vital for rational design of drug delivery systems. In particular, for core-shell or surface-modified nanoparticles surface structure can be described in terms of shell coating uniformity and shell thickness uniformity around the nanoparticle core. Taken together, these terms can be used to indicate degree of heterogeneity of nanoparticle surface structure. However, characterization of nanoparticle surface structure under physiological conditions is challenging due to limitations of experimental techniques. In this paper, we apply SAXS contrast variation combined with ab initio bead modeling for this purpose. Approach is based on the fact that nanoparticles under study are produced by self-assembly of phospholipid-conjugated molecules that possess moieties with significantly different electron densities enabling SAXS technique to be used to distinguish nanoparticle shell and study its structure. Ab initio single phase and ab initio multiphase modeling based on SAXS curve of nanoparticles in phosphate buffer solution allowed to reconstruct nanoparticle shell coating and assess its uniformity, while serial nanoparticle reconstructions from solutions with gradually increased solvent electron densities revealed relative shell coating thickness around nanoparticle core. Nanoparticle shell structure representation was verified by molecular dynamics simulation and derived full-atom nanoparticle shell structure showed good agreement with SAXS-derived representation. Obtained data indicate that studied nanoparticles exhibit highly heterogeneous surface structure.

Perspectives on complement and phagocytic cell responses to nanoparticles: From fundamentals to adverse reactions

The complement system, professional phagocytes and other cells such as Natural killer cells and mast cells are among the important components of the innate arm of the immune system. These constituents provide an orchestrated array of defences and responses against tissue injury and foreign particles, including nanopharmaceuticals. While interception of nanopharmaceuticals by the immune system is beneficial for immunomodulation and treatment of phagocytic cell disorders, it is imperative to understand the multifaceted mechanisms by which nanopharmaceuticals interacts with the immune system and evaluate the subsequent balance of beneficial versus adverse reactions. An example of the latter is adverse infusion reactions to regulatory-approved nanopharmaceuticals seen in human subjects. Here, we discuss collective opinions and findings from our laboratories in mapping nanoparticle-mediated complement and leucocyte/macrophage responses.

Cell membrane-coated nanoparticles: a novel multifunctional biomimetic drug delivery system

Recently, nanoparticle-based drug delivery systems have been widely used for the treatment, prevention, and detection of diseases. Improving the targeted delivery ability of nanoparticles has emerged as a critical issue that must be addressed as soon as possible. The bionic cell membrane coating technology has become a novel concept for the design of nanoparticles. The diverse biological roles of cell membrane surface proteins endow nanoparticles with several functions, such as immune escape, long circulation time, and targeted delivery; therefore, these proteins are being extensively studied in the fields of drug delivery, detoxification, and cancer treatment. Furthermore, hybrid cell membrane-coated nanoparticles enhance the beneficial effects of monotypic cell membranes, resulting in multifunctional and efficient delivery carriers. This review focuses on the synthesis, development, and application of the cell membrane coating technology and discusses the function and mechanism of monotypic/hybrid cell membrane-modified nanoparticles in detail. Moreover, it summarizes the applications of cell membranes from different sources and discusses the challenges that may be faced during the clinical application of bionic carriers, including their production, mechanism, and quality control. We hope this review will attract more scholars toward bionic cell membrane carriers and provide certain ideas and directions for solving the existing problems.

Macrophage membrane-biomimetic adhesive polycaprolactone nanocamptothecin for improving cancer-targeting efficiency and impairing metastasis

The recent remarkable success and safety of mRNA lipid nanoparticle technology for producing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines has stimulated intensive efforts to expand nanoparticle strategies to treat various diseases. Numerous synthetic nanoparticles have been developed for pharmaceutical delivery and cancer treatment. However, only a limited number of nanotherapies have enter clinical trials or are clinically approved. Systemically administered nanotherapies are likely to be sequestered by host mononuclear phagocyte system (MPS), resulting in suboptimal pharmacokinetics and insufficient drug concentrations in tumors. Bioinspired drug-delivery formulations have emerged as an alternative approach to evade the MPS and show potential to improve drug therapeutic efficacy. Here we developed a biodegradable polymer-conjugated camptothecin prodrug encapsulated in the plasma membrane of lipopolysaccharide-stimulated macrophages. Polymer conjugation revived the parent camptothecin agent (e.g., 7-ethyl-10-hydroxy-camptothecin), enabling lipid nanoparticle encapsulation. Furthermore, macrophage membrane cloaking transformed the nonadhesive lipid nanoparticles into bioadhesive nanocamptothecin, increasing the cellular uptake and tumor-tropic effects of this biomimetic therapy. When tested in a preclinical murine model of breast cancer, macrophage-camouflaged nanocamptothecin exhibited a higher level of tumor accumulation than uncoated nanoparticles. Furthermore, intravenous administration of the therapy effectively suppressed tumor growth and the metastatic burden without causing systematic toxicity. Our study describes a combinatorial strategy that uses polymeric prodrug design and cell membrane cloaking to achieve therapeutics with high efficacy and low toxicity. This approach might also be generally applicable to formulate other therapeutic candidates that are not compatible or miscible with biomimetic delivery carriers.

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Macrophage membrane-biomimetic platform was exploited for nanodelivery of polycaprolactone nanocamptothecin.

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Macrophage-camouflaged nanocamptothecin exhibited tumor-tropic effects and increased tumor cell adhesion.

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The nanotherapy effectively suppressed primary tumor growth and the metastatic burden in vivo.

Lipid nano-carriers loaded with Cannabis sativa extract for epilepsy treatment - in vitro characterization and in vivo efficacy studies

Taking into consideration the latest reported beneficial anticolvusant effects of cannabidiol (CBD) and cannabiodiolic acid (CBDA) for clinical applications and the advantages of lipid nano-systems as carriers for targeted brain delivery, the aim of this study was set in direction of in vitro physico-chemical and biopharmaceutical characterization and in vivo evaluation of nanoliposomes and nanostructured lipid carriers loaded with Cannabis sativa extract intended for safe and efficient transport via blood-brain barrier and treatment of epilepsy. These nanoliposomes and nanostructured lipid formulations were characterized with z-average diameter <200 nm, following unimodal particle size distribution, negative values for Z-potential, high drug encapsulation efficiency and prolonged release during 24h (38.84-60.91 %). Prepared formulations showed statistically significant higher antioxidant capacity compared to the extract. The results from in vivo studies of the anticonvulsant activity demonstrated that all formulations significantly elevated the latencies for myoclonic, clonic and tonic seizures and, therefore, could be used in preventing different types of seizures. A distinction in the potential of the nano-systems was noted, which was probably anticipated by the type and the characteristics of the prepared formulations.

Recent trends in platelet membrane-cloaked nanoparticles for application of inflammatory diseases

Platelets are multifunctional effectors of inflammatory responses and inseparable from the occurrence and development of various inflammatory diseases. The platelet membrane (PM) is integrated onto the surface of a nano-drug delivery system to form the PM-cloaked nanoparticles (PM@NPs), which can increase the biocompatibility of the nano-drug delivery system and mitigate adverse drug reactions. Owing to the strong affinity of immune regulation and adhesion-related antigens on the surface of PM to the focal sites of inflammatory diseases, which endows PM@NPs with the potential to actively target lesions and improve the therapeutic efficacy of drugs for inflammatory diseases. Based on latest developments in PM biomimetic technique and nanomedicine for the treatment of inflammatory diseases, this paper mainly elaborates three aspects: advantages of PM@NPs, experimental foundation of PM biomimetic nanotechnology, and applications of PM@NPs to the treatment of inflammatory diseases. The aim is to provide reference for the development and application of PM@NPs and novel insights into the treatment of inflammatory diseases.

Allergy Electronic Health Record Documentation: A 2022 Work Group Report of the AAAAI Adverse Reactions to Drugs, Biologicals, and Latex Committee

The allergy section of the electronic health record (EHR) is ideally reviewed and updated by health care workers during routine outpatient visits, emergency room visits, inpatient hospitalizations, and surgical procedures. This EHR section has the potential to help proactively and comprehensively avoid exposures to drugs, contact irritants, foods, and other agents for which, based on an individual's medical history and/or genetics, there is increased risk for adverse outcomes with future exposures. Because clinical decisions are made and clinical decision support is triggered based on allergy details from the EHR, the allergy module needs to provide meaningful, accurate, timely, and comprehensive allergy information. Although the allergy section of the EHR must meet these requirements to guide appropriate clinical decisions and treatment plans, current EHR allergy modules have not achieved this standard. We urge EHR vendors to collaborate with allergists to optimize and modernize allergy documentation. A work group within the Adverse Reactions to Drugs, Biologicals, and Latex Committee of the American Academy of Allergy, Asthma & Immunology was formed to create recommendations for allergy documentation in the EHR. Whereas it is recognized that the term "allergy" is often used incorrectly because most adverse drug reactions (ADRs) are not true immune-mediated hypersensitivity reactions, "allergy" in this article includes allergies and hypersensitivities as well as side effects and intolerances. Our primary objective is to provide guidance for the current state of allergy documentation in the EHR. This guidance includes clarification of the definition of specific ADR types, reconciliation of confirmed ADRs, and removal of disproved or erroneous ADRs. This document includes a proposal for the creation, education, and implementation of a drug allergy labeling system that may allow for more accurate EHR documentation for improved patient safety.

Nanometer- and angstrom-scale characteristics that modulate complement responses to nanoparticles

The contribution of the complement system to non-specific host defence and maintenance of homeostasis is well appreciated. Many particulate systems trigger complement activation but the underlying mechanisms are still poorly understood. Activation of the complement cascade could lead to particle opsonisation by the cleavage products of the third complement protein and might promote inflammatory reactions. Antibody binding in a controlled manner and/or sensing of particles by the complement pattern-recognition molecules such as C1q and mannose-binding lectin can trigger complement activation. Particle curvature and spacing arrangement/periodicity of surface functional groups/ligands are two important parameters that modulate complement responses through multivalent engagement with and conformational regulation of surface-bound antibodies and complement pattern-recognition molecules. Thus, a better fundamental understanding of nanometer- and angstrom-scale parameters that modulate particle interaction with antibodies and complement proteins could portend new possibilities for engineering of particulate drug carriers and biomedical platforms with tuneable complement responses and is discussed here.

Integrated Platform of Oxygen Self-enriched Nanovesicles: SP94 Peptide-directed Chemo/sonodynamic Therapy for Liver Cancer

Hepatocellular carcinoma (HCC) is a most common primary liver cancer among the most deadly malignancies. Selectively killing the cancer cells within the liver urgently requires the novel treatment strategies. The combination of sonodynamic therapy (SDT) and chemotherapy based on the nanotechnology have achieved some achievements in the HCC treatments. However, off-targeting drug delivery to healthy cells and the hypoxic microenvironment in the solid tumors frustrate the efforts to the combined strategy. The hypoxic microenvironment restrains the generation of ROS, leading to the decreased effects of SDT. To improve the clinical outcomes of chemo/SDT strategy, we created a novel oxygen self-enriched active targeted nanovesicle (ICG-DOX NPs/PFH@SP94-Lip). SP94 peptide could enhance the selectivity of the nanovesicles to liver tumor cells rather than normal liver cells. Besides, an oxygen carrier, perfluorohexanes (PFH), was co-loaded into liposomes to increase the oxygen level in tumor tissue, thus improving the effects of SDT. The in vivo studies showed that the ICG-DOX NPs/PFH@SP94-Lip combined with the external US stimulation significantly inhibited effects on tumor growth. Therefore, this novel oxygen self-enriched chemo/SDT nanocomposites represents a proof-of-concept liver tumor treatment strategy.

Coronavirus disease 2019 vaccine administration in patients with reported reactions to polyethylene glycol- and polysorbate-containing therapeutics

BACKGROUND

Polyethylene glycol (PEG) and polysorbate reactions were initially implicated as a likely risk factor for reacting to coronavirus disease 2019 (COVID-19) vaccines and remain a source of vaccine hesitancy despite increasing evidence that they do not pose an increased risk for COVID-19 vaccine reactions.

OBJECTIVE

To investigate COVID-19 vaccine safety outcomes in patients with reported reactions to PEG- and polysorbate-containing medications and vaccines.

METHODS

COVID-19 vaccine safety was reviewed in patients with PEG or polysorbate reactions documented in their electronic medical records at a tertiary academic medical center (cohort 1) and patients referred to Allergy and Immunology with reported PEG or polysorbate reactions (cohort 2). COVID-19 vaccine safety was also reviewed following reported symptoms (onset ≤ 12 hours) to first-dose PEG-containing messenger RNA (mRNA) COVID-19 vaccine (cohort 3).

RESULTS

Of 252 patients in cohort 1 (n = 202) and cohort 2 (n = 50), 236 (94%) received mRNA COVID-19 vaccines (106 Pfizer, 130 Moderna); 235 received both doses. Only 3 patients from cohort 2 developed mild rash following vaccination. None of the 44 patients in cohort 3 with acute symptoms following first-dose mRNA COVID-19 vaccine (27 Pfizer, 17 Moderna) had previously reported PEG or polysorbate reactions. Of these 44 patients, 43 received the second dose and all 3 who developed symptoms following the second dose (1 required epinephrine) had negative PEG skin testing.

CONCLUSION

Patients with reported reactions to PEG and polysorbate safely received COVID-19 vaccines. PEG and polysorbate skin testing did not identify patients at risk for first dose or recurrent reactions to COVID-19 vaccines. Screening for PEG and polysorbate allergy may only increase vaccine hesitancy without identifying patients at risk for COVID-19 vaccine reactions.

Understanding the Role and Impact of Poly (Ethylene Glycol) (PEG) on Nanoparticle Formulation: Implications for COVID-19 Vaccines

Poly (ethylene glycol) (PEG) is a widely used polymer in a variety of consumer products and in medicine. PEGylation refers to the conjugation of PEG to drugs or nanoparticles to increase circulation time and reduce unwanted host responses. PEG is viewed as being well-tolerated, but previous studies have identified anti-PEG antibodies and so-called pseudoallergic reactions in certain individuals. The increased use of nanoparticles as contrast agents or in drug delivery, along with the introduction of mRNA vaccines encapsulated in PEGylated lipid nanoparticles has brought this issue to the fore. Thus, while these vaccines have proven to be remarkably effective, rare cases of anaphylaxis have been reported, and this has been tentatively ascribed to the PEGylated carriers, which may trigger complement activation in susceptible individuals. Here, we provide a general overview of the use of PEGylated nanoparticles for pharmaceutical applications, and we discuss the activation of the complement cascade that might be caused by PEGylated nanomedicines for a better understanding of these immunological adverse reactions.

Synthetic Glyconanoparticles Modulate Innate Immunity but Not the Complement System

Nanoparticles that modulate innate immunity can act as vaccine adjuvants and antigen carriers and are promising alternatives to conventional anticancer therapy. Nanoparticles might, upon contact with serum, activate the complement system that might in turn result in clearance and allergic reactions. Herein, we report that ultrasmall glyconanoparticles decorated with nonimmunogenic α-(1-6)-oligomannans trigger an innate immune response without drastically affecting the complement system. These negatively charged glyconanoparticles (10-15 nm) are stable in water and secrete proinflammatory cytokines from macrophages via the NF-κB signaling pathway. The glyconanoparticles can be used as immunomodulators for monotherapy or in combination with drugs and vaccines.

Cell-membrane-inspired polymers for constructing biointerfaces with efficient molecular recognition

Fabrication of devices that accurately recognize, detect, and separate target molecules from mixtures is a crucial aspect of biotechnology for applications in medical, pharmaceutical, and food sciences. This technology has also been recently applied in solving environmental and energy-related problems. In molecular recognition, biomolecules are typically complexed with a substrate, and specific molecules from a mixture are recognized, captured, and reacted. To increase sensitivity and efficiency, the activity of the biomolecules used for capture should be maintained, and non-specific reactions on the surface should be prevented. This review summarizes polymeric materials that are used for constructing biointerfaces. Precise molecular recognition occurring at the surface of cell membranes is fundamental to sustaining life; therefore, materials that mimic the structure and properties of this particular surface are emphasized in this article. The requirements for biointerfaces to eliminate nonspecific interactions of biomolecules are described. In particular, the major issue of protein adsorption on biointerfaces is discussed by focusing on the structure of water near the interface from a thermodynamic viewpoint; moreover, the structure of polymer molecules that control the water structure is considered. Methodologies enabling stable formation of these interfaces on material surfaces are also presented.

Broad-Spectrum Theranostics and Biomedical Application of Functionalized Nanomaterials

Nanotechnology is an important branch of science in therapies known as “nanomedicine” and is the junction of various fields such as material science, chemistry, biology, physics, and optics. Nanomaterials are in the range between 1 and 100 nm in size and provide a large surface area to volume ratio; thus, they can be used for various diseases, including cardiovascular diseases, cancer, bacterial infections, and diabetes. Nanoparticles play a crucial role in therapy as they can enhance the accumulation and release of pharmacological agents, improve targeted delivery and ultimately decrease the intensity of drug side effects. In this review, we discussthe types of nanomaterials that have various biomedical applications. Biomolecules that are often conjugated with nanoparticles are proteins, peptides, DNA, and lipids, which can enhance biocompatibility, stability, and solubility. In this review, we focus on bioconjugation and nanoparticles and also discuss different types of nanoparticles including micelles, liposomes, carbon nanotubes, nanospheres, dendrimers, quantum dots, and metallic nanoparticles and their crucial role in various diseases and clinical applications. Additionally, we review the use of nanomaterials for bio-imaging, drug delivery, biosensing tissue engineering, medical devices, and immunoassays. Understandingthe characteristics and properties of nanoparticles and their interactions with the biological system can help us to develop novel strategies for the treatment, prevention, and diagnosis of many diseases including cancer, pulmonary diseases, etc. In this present review, the importance of various kinds of nanoparticles and their biomedical applications are discussed in much detail.

Population-Based Incidence, Severity, and Risk Factors Associated with Treated Acute-Onset COVID-19 mRNA Vaccination-Associated Hypersensitivity Reactions

BACKGROUND

COVID-19 mRNA vaccination-associated acute-onset hypersensitivity reactions have caused anxiety and may be contributing to vaccine hesitancy.

OBJECTIVE

To determine the incidence, severity, and risk factors for treated acute-onset COVID-19 mRNA vaccination-associated hypersensitivity reactions in a well-characterized population.

METHODS

All Kaiser Permanente Southern California (KPSC) members who received COVID-19 mRNA vaccinations between December 15, 2020, and March 11, 2021, at a KPSC facility were identified and characterized, along with all treated acute-onset vaccination-associated hypersensitivity events.

RESULTS

We identified 391,123 unique vaccine recipients (59.18% female, age 64.19 ± 17.86 years); 215,156 received 2 doses (53.54% Moderna), 157,615 only a first dose (50.13% Moderna) (1961 [1.46%] >2 weeks late getting a second dose), and 18,352 (74.43% Moderna) only a second dose. Only 104 (0.028%) (85.58% female, age 53.18 ± 15.96 years) had treated first dose events, 68 (0.030%) Moderna. Only 32 (0.014%) (93.75% female, age 57.28 ± 17.09 years) had treated second dose events, 21 (0.016%) Moderna. Only 2 (0.00033%) vaccinations resulted in anaphylaxis. Only 27 (20.77%) of those with treated first dose reactions failed to get a second dose. Only 6 of 77 (7.8%) with first dose reactions also had second dose reactions. Individuals with treated events were more likely to be female (P < .0001), younger (P < .0001), and had more pre-existing drug "allergies" (2.11 ± 2.12 vs 1.02 ± 1.41 [P < .0001] for average recipients).

CONCLUSIONS

Treated acute-onset hypersensitivity events were mostly benign, more common with first COVID-19 mRNA vaccine doses, more likely to occur in younger females with typical risk factors associated with multiple drug intolerance syndrome, and very unlikely to be primarily immunologically mediated.

Cationic Nanomaterials for Autoimmune Diseases Therapy

Cationic nanomaterials are defined as nanoscale structures smaller than 100 nm bearing positive charges. They have been investigated to apply to many aspects including clinical diagnosis, gene delivery, drug delivery, and tissue engineering for years. Recently, a novel concept has been made to use cationic nanomaterials as cell-free nucleic acid scavengers and inhibits the inflammatory responses in autoimmune diseases. Here, we highlighted different types of cationic materials which have the potential for autoimmune disease treatment and reviewed the strategy for autoimmune diseases therapy based on cationic nanoparticles. This review will also demonstrate the challenges and possible solutions that are encountered during the development of cationic materials-based therapeutics for autoimmune diseases.

Internalization and Transport of PEGylated Lipid-Based Mixed Micelles across Caco-2 Cells Mediated by Scavenger Receptor B1

The aim of this study was to get insight into the internalization and transport of PEGylat-ed mixed micelles loaded by vitamin K, as mediated by Scavenger Receptor B1 (SR-B1) that is abundantly expressed by intestinal epithelium cells as well as by differentiated Caco-2 cells. Inhibition of SR-B1 reduced endocytosis and transport of vitamin-K-loaded 0%, 30% and 50% PEGylated mixed micelles and decreased colocalization of the micelles with SR-B1. Confocal fluorescence microscopy, fluorescence-activated cell sorting (FACS) analysis, and surface plasmon resonance (SPR) were used to study the interaction between the mixed micelles of different compositions (varying vitamin K loading and PEG content) and SR-B1. Interaction of PEGylated micelles was independent of the vitamin K content, indicating that the PEG shell prevented vitamin K exposure at the surface of the micelles and binding with the receptor and that the PEG took over the micelles' ability to bind to the receptor. Molecular docking calculations corroborated the dual binding of both vita-min K and PEG with the binding domain of SR-B1. In conclusion, the improved colloidal stability of PEGylated mixed micelles did not compromise their cellular uptake and transport due to the affinity of PEG for SR-B1. SR-B1 is able to interact with PEGylated nanoparticles and mediates their subsequent internalization and transport.

Getting to the Core of It All: Nanocapsules to Mitigate Infusion Reactions Can Promote Hemostasis and Be a Platform for Intravenous Therapies

One of the significant challenges to translation of intravenously administered nanomaterials has been complement-mediated infusion reactions which can be lethal. Slow infusions can reduce infusion reactions, but slow infusions are not always possible in applications like controlling bleeding following trauma. Thus, avoiding complement activation and infusion responses is essential to manage bleeding. We identified nanocapsules based on polyurethane as candidates that did not activate C5a and explored their PEGylation and functionalization with the GRGDS peptide to create a new class of hemostatic nanomaterials. Using the clinically relevant rotational thromboelastography (ROTEM), we determined that nanocapsules promote faster clotting than controls and maintain the maximum clot firmness, which is critical for reducing bleeding. Excitingly, these polyurethane-based nanocapsules did not activate complement or the major pro-inflammatory cytokines. This work provides critical evidence for the role of modulating the core material in developing safer nanomedicines for intravenous applications.

Drug delivery systems as immunomodulators for therapy of infectious disease: Relevance to COVID-19

The emergence of SARS-CoV-2, and the ensuing global pandemic, has resulted in an unprecedented response to identify therapies that can limit uncontrolled inflammation observed in patients with moderate to severe COVID-19. The immune pathology behind COVID-19 is complex and involves the activation and interaction of multiple systems including, but not limited to, complement, inflammasomes, endothelial as well as innate and adaptive immune cells to bring about a convoluted profile of inflammation, coagulation and tissue damage. To date, therapeutic approaches have focussed on inhibition of coagulation, untargeted immune suppression and/or cytokine-directed blocking agents. Regardless of recently achieved improvements in individual patient outcomes and survival rates, improved and focussed approaches targeting individual systems involved is needed to further improve prognosis and wellbeing. This review summarizes the current understanding of molecular and cellular systems involved in the pathophysiology of COVID-19, and their contribution to pathogen clearance and damage to then discuss possible therapeutic options involving immunomodulatory drug delivery systems as well as summarising the complex interplay between them.

Vaccine-Associated Thrombocytopenia and Thrombosis: Venous Endotheliopathy Leading to Venous Combined Micro-Macrothrombosis

Serious vaccine-associated side effects are very rare. Major complications of vaccines are thrombocytopenia and thrombosis in which pathogenetic mechanism is consistent with endotheliopathy characterized by "attenuated" sepsis-like syndrome, leading to the activation of inflammatory and microthrombotic pathway. In the COVID-19 pandemic, acute respiratory distress syndrome caused by microthrombosis has been the major clinical phenotype from the viral sepsis in association with endotheliopathy-associated vascular microthrombotic disease (EA-VMTD), sometimes presenting with thrombotic thrombocytopenic purpura (TTP)-like syndrome. Often, venous thromboembolism has coexisted due to additional vascular injury. In contrast, clinical phenotypes of vaccine complication have included "silent" immune thrombocytopenic purpura (ITP-like syndrome), multiorgan inflammatory syndrome, and deep venous thrombosis (DVT), cerebral venous sinus thrombosis (CVST) in particular. These findings are consistent with venous (v) EA-VMTD. In vEA-VMTD promoted by activated complement system following vaccination, "consumptive" thrombocytopenia develops as ITP-like syndrome due to activated unusually large von Willebrand factor (ULVWF) path of hemostasis via microthrombogenesis. Thus, the pathologic phenotype of ITP-like syndrome is venous microthrombosis. Myocarditis/pericarditis and other rare cases of inflammatory organ syndrome are promoted by inflammatory cytokines released from activated inflammatory pathway, leading to various organ endotheliitis. Vaccine-associated CVST is a form of venous combined "micro-macrothrombosis" composed of binary components of "microthrombi strings" from vEA-VMTD and "fibrin meshes" from vaccine-unrelated incidental vascular injury perhaps such as unreported head trauma. This mechanism is identified based on "two-path unifying theory" of in vivo hemostasis. Venous combined micro-macrothrombosis due to vaccine is much more serious thrombosis than isolated distal DVT made of macrothrombus. This paradigm changing novel concept of combined micro-macrothrombosis implies the need of combined therapy of a complement inhibitor and anticoagulant for CVST and other complex forms of DVT.

Engineering PEGylated Polyester Nanoparticles to Reduce Complement-Mediated Infusion Reaction

Translation of intravenously administered nanomaterials to the clinic is limited due to adverse infusion reactions. While these reactions are infrequent, with up to 10% prone to experiencing infusion reactions, the reactions can be severe and life-threatening. One of the innate immune pathways, the complement activation pathway, plays a significant role in mediating this response. Nanoparticle surface properties are a relevant design feature, as they control the blood proteins the nanoparticles interact with and allow the nanoparticles to evade the immune reaction. PEGylation of nanosurfaces is critical in improving the blood circulation of nanoparticles and reducing opsonization. Our goal was to understand whether modifying the surface architecture by varying the PEG density and architecture can impact the complement response in vitro. We utilized block copolymers of poly(lactic acid)-b-poly(ethylene glycol) prepared with poly(ethylene glycol) macroinitiators of molecular weights 3400 and 5000 Da. Tracking the complement biomarker C5a, we monitored the impact of changing PEGylation of the nanoparticles. We also investigated how the changing PEG length on the nanoparticle surface impacts further strengthening the stealth properties. Lastly, we determined which cytokines change upon blood incubation with nanoparticles in vitro to understand the extent to which inflammation may occur and the crosstalk between the complement and immune responses. Increasing PEGylation reduced the generation of complement-mediated anaphylatoxin C5a in vitro, with 5000 Da PEG more effectively reducing levels of C5a generated compared to 3400 Da PEG. The insights gathered regarding the impact of PEG density and PEG chain length would be critical in developing stealth nanoparticles that do not lead to infusion reactions upon intravenous administration.

Boosting nanomedicine performance by conditioning macrophages with methyl palmitate nanoparticles

Surface PEGylation, biological camouflage, shape and stiffness modulation of nanoparticles as well as liver blockade and macrophage depletion have all improved the blood longevity of nanomedicines. Yet, the mononuclear phagocytic system still recognizes, sequesters, and processes the majority of blood borne particles. Here, the natural fatty acid methyl palmitate is combined with endogenous blood components - albumin - realizing ∼200 nm stable, spherical nanoparticles (MPN) capable of inducing a transient and reversible state of dormancy into macrophages. In primary bone marrow derived monocytes (BMDM), the rate of internalization of 5 different particles, ranging in size from 200 up to 2000 nm, with spherical and discoidal shapes, and made out of lipids and polymers, was almost totally inhibited after an overnight pre-treatment with 0.5 mM MPN. Microscopy analyses revealed that MPN reversibly reduced the extension and branching complexity of the microtubule network in BMDM, thus altering membrane bulging and motility. In immunocompetent mice, a 4 h pre-treatment with MPN was sufficient to redirect 2000 nm rigid particles from the liver to the lungs realizing a lung-to-liver accumulation ratio larger than 2. Also, in mice bearing U87-MG tumor masses, a 4 h pre-treatment with MPN enhanced the therapeutic efficacy of docetaxel-loaded nanoparticles significantly inhibiting tumor growth. The natural liver sequestering function was fully recovered overnight. This data would suggest that MPN pre-treatment could transiently and reversibly inhibit non-specific particle sequestration, thus redirecting nanomedicines towards their specific target tissue while boosting their anti-cancer efficacy and imaging capacity.

Nanoparticle theranostics in cardiovascular inflammation

Theranostics, literally derived from the combination of the words diagnostics and therapy, is an emerging field of clinical and preclinical research, where contrast agents, drugs and diagnostic techniques are combined to simultaneously diagnose and treat pathologies. Nanoparticles are extensively employed in theranostics due to their potential to target specific organs and their multifunctional capacity. In this review, we will discuss the current state of theranostic nanomedicine, providing key examples of its application in the imaging and treatment of cardiovascular inflammation.

Differently PEGylated Polymer Nanoparticles for Pancreatic Cancer Delivery: Using a Novel Near-Infrared Emissive and Biodegradable Polymer as the Fluorescence Tracer

In this study, a chemically synthetic polymer, benzo[1,2-b:4,5-b']difuran(BDF)-based donor-acceptor copolymer PBDFDTBO, was individually coated by amphiphilic poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-PCL) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy(polyethylene glycol) (DSPE-PEG or PEG-DSPE), to form stably fluorescent nanoparticles in the near-infrared (NIR) window. The physicochemical properties of the synthesized nanoparticles were characterized and compared, including their size, surface charge, and morphology. In addition, in vitro studies were also performed using two pancreatic cancer cell lines, assessing the cell viability of the PBDFDTBO-included PEGylated nanoparticles formulations. Moreover, in vivo studies were also conducted, using subcutaneous murine cancer models to investigate the polymeric nanoparticles' circulation time, tumor accumulation, and preferred organ biodistribution. The overall results demonstrated that even with the same PEGylated surface, the hydrophobic composition anchored on the encapsulated PBDFDTBO core strongly affected the biodistribution and tumor accumulation of the nanoparticles, to a degree possibly determined by the hydrophobic interactions between the hydrophobic segment of amphiphilic polymers (DSPE or PCL moiety) and the enwrapped PBDFDTBO. Both PEGylated nanoparticles were compared to obtain an optimized coating strategy for a desired biological feature in pancreatic cancer delivery.

Effects of polyethylene glycol on the surface of nanoparticles for targeted drug delivery

The rapid development of drug nanocarriers has benefited from the surface hydrophilic polymers of particles, which has improved the pharmacokinetics of the drugs. Polyethylene glycol (PEG) is a kind of polymeric material with unique hydrophilicity and electrical neutrality. PEG coating is a crucial factor to improve the biophysical and chemical properties of nanoparticles and is widely studied. Protein adherence and macrophage removal are effectively relieved due to the existence of PEG on the particles. This review discusses the PEGylation methods of nanoparticles and related techniques that have been used to detect the PEG coverage density and thickness on the surface of the nanoparticles in recent years. The molecular weight (MW) and coverage density of the PEG coating on the surface of nanoparticles are then described to explain the effects on the biophysical and chemical properties of nanoparticles.

The Martini Model in Materials Science

The Martini model, a coarse-grained force field initially developed with biomolecular simulations in mind, has found an increasing number of applications in the field of soft materials science. The model's underlying building block principle does not pose restrictions on its application beyond biomolecular systems. Here, the main applications to date of the Martini model in materials science are highlighted, and a perspective for the future developments in this field is given, particularly in light of recent developments such as the new version of the model, Martini 3.

The Fate of Nanoparticles In Vivo and the Strategy of Designing Stealth Nanoparticle for Drug Delivery

Nano-drug delivery systems (Nano-DDS) offer powerful advantages in drug delivery and targeted therapy for diseases. Compared to the traditional drug formulations, Nano-DDS can increase solubility, biocompatibility, and reduce off-targeted side effects of free drugs. However, they still have some disadvantages that pose a limitation in reaching their full potential in clinical use. Protein adsorption in blood, activation of the complement system, and subsequent sequestration by the mononuclear phagocyte system (MPS) consequently result in nanoparticles (NPs) to be rapidly cleared from circulation. Therefore, NPs have low drug delivery efficiency. So, it is important to develop stealth NPs for reducing bio-nano interaction. In this review, we first conclude the interaction between NPs and biological environments, such as blood proteins and MPS, and factors influencing each other. Next, we will summarize the new strategies to reduce NPs protein adsorption and uptake by the MPS based on current knowledge of the bio-nano interaction. Further directions will also be highlighted for the development of biomimetic stealth nano-delivery systems by combining targeted strategies for a better therapeutic effect.

Surface Decoration of Cetyltrimethyl Ammonium Bromide on SiC Particles and Its Effects on the Co-Deposition Process

Cetyltrimethyl ammonium bromide (CTAB) is used to decorate the SiC particle surface. The mechanism of the decoration process has been studied by simulation and experimental approaches. Molecular dynamics (MD) simulation finds a bilayer adsorbed structure of CTAB on the SiC particles, which is then verified by Fourier-transform infrared and thermal gravimetric analysis measurements. The MD simulation also finds that the decorative effects of CTAB on the SiC particle surface are related to the surface charge condition of the SiC particles and the concentration of CTAB. The measured zeta potential of the SiC particles shows dependence on the pH condition and the concentration of CTAB. The decorated SiC particles are used to produce composition by the co-deposition technology. With the help of CTAB, SiC particles are successfully incorporated in the deposited layer, where the content of SiC particles is dependent on the concentration of CTAB and the pH of the bath.

Recent Advancements of Specific Functionalized Surfaces of Magnetic Nano- and Microparticles as a Theranostics Source in Biomedicine

Magnetic nano- and microparticles (MNMPs) belong to a highly versatile class of colloids with actuator and sensor properties that have been broadly studied for their application in theranostics such as molecular imaging and drug delivery. The use of advanced biocompatible, biodegradable polymers and polyelectrolytes as MNMP coating materials is essential to ensure the stability of MNMPs and enable efficient drug release while at the same time preventing cytotoxic effects. In the past years, huge progress has been made in terms of the design of MNMPs. Especially, the understanding of coating formation with respect to control of drug loading and release kinetics on the molecular level has significantly advanced. In this review, recent advancements in the field of MNMP surface engineering and the applicability of MNMPs in research fields of medical imaging, diagnosis, and nanotherapeutics are presented and discussed. Furthermore, in this review the main emphasis is put on the manipulation of biological specimens and cell trafficking, for which MNMPs represent a favorable tool enabling transport processes of drugs through cell membranes. Finally, challenges and future perspectives for applications of MNMPs as theranostic nanomaterials are discussed.