When liposomes met antibodies: Drug delivery and beyond

Antibody-Calixarene Drug Conjugate: A General Drug Delivery Platform for Tumor-Targeted Therapy

Antibody-drug conjugates (ADCs), which combine the precise targeting capabilities of antibodies with the powerful cytotoxicity of small-molecule drugs, have evolved into a promising approach for tumor treatment. However, the traditional covalent coupling method requires the design of a specific linker tailored to the properties of the small-molecule drugs, which greatly limits the development of ADCs and the range of drugs that can be used. Herein, a novel type of antibody-calixarene drug conjugates (ACDCs) that function similarly to ADCs by delivering drugs to their targets using antibodies but without the requirement of covalent conjugation of the drugs with antibodies is presented. By replacement of conventional linkers with supramolecular linkers, the ACDCs can load various chemotherapeutic drugs through host-guest interactions. Furthermore, ACDCs are readily reduced upon reaching the hypoxic microenvironment, resulting in rapid release of the drugs. With this precise drug encapsulation and controlled release mechanism, ACDCs deliver drugs to tumor tissues effectively and achieve a significantly enhanced antitumor effect. Considering that the ACDCs can be easily prepared by combining antibody-calixarene conjugates derived from tumor-targeting antibodies with various small-molecule drugs, ACDCs may provide a promising platform technology to accelerate ADC development and thus improve the therapeutic efficacy of chemotherapy.

Construction Strategy of Functionalized Liposomes and Multidimensional Application

Liposomes are widely used in the biological field due to their good biocompatibility and surface modification properties. With the development of biochemistry and material science, many liposome structures and their surface functional components have been modified and optimized one by one, pushing the liposome platform from traditional to functionalized and intelligent, which will better satisfy and expand the needs of scientific research. However, a main limiting factor effecting the efficiency of liposomes is the complicated environmental conditions in the living body. Currently, in order to overcome the above problem, functionalized liposomes have become a very promising strategy. In this paper, binding strategies of liposomes with four main functional elements, namely nucleic acids, antibodies, peptides, and stimuli-responsive motif have been summarized for the first time. In addition, based on the construction characteristics of functionalized liposomes, such as drug-carrying, targeting, long-circulating, and stimulus-responsive properties, a comprehensive overview of their features and respective research progress are presented. Finally, the paper critically presents the limitations of these functionalized liposomes in the current applications and also prospectively suggests the future development directions, aiming to accelerate realization of their industrialization.

Valrubicin-loaded immunoliposomes for specific vesicle-mediated cell death in the treatment of hematological cancers

We created valrubicin-loaded immunoliposomes (Val-ILs) using the antitumor prodrug valrubicin, a hydrophobic analog of daunorubicin. Being lipophilic, valrubicin readily incorporated Val-lLs that were loaded with specific antibodies. Val-ILs injected intravenously rapidly reached the bone marrow and spleen, indicating their potential to effectively target cancer cells in these areas. Following the transplantation of human pediatric B-cell acute lymphoblastic leukemia (B-ALL), T-cell acute lymphoblastic leukemia (T-ALL), or acute myeloid leukemia (AML) in immunodeficient NSG mice, we generated patient-derived xenograft (PDX) models, which were treated with Val-ILs loaded with antibodies to target CD19, CD7 or CD33. Only a small amount of valrubicin incorporated into Val-ILs was needed to induce leukemia cell death in vivo, suggesting that this approach could be used to efficiently treat acute leukemia cells. We also demonstrated that Val-ILs could reduce the risk of contamination of CD34+ hematopoietic stem cells by acute leukemia cells during autologous peripheral blood stem cell transplantation, which is a significant advantage for clinical applications. Using EL4 lymphoma cells on immunocompetent C57BL/6 mice, we also highlighted the potential of Val-ILs to target immunosuppressive cell populations in the spleen, which could be valuable in impairing cancer cell expansion, particularly in lymphoma cases. The most efficient Val-ILs were found to be those loaded with CD11b or CD223 antibodies, which, respectively, target the myeloid-derived suppressor cells (MDSC) or the lymphocyte-activation gene 3 (LAG-3 or CD223) on T4 lymphocytes. This study provides a promising preclinical demonstration of the effectiveness and ease of preparation of Val-ILs as a novel nanoparticle technology. In the context of hematological cancers, Val-ILs have the potential to be used as a precise and effective therapy based on targeted vesicle-mediated cell death.

Anti-HER2 Immunoliposomes: Antitumor Efficacy Attributable to Targeted Delivery of Anthraquinone-Fused Enediyne

Although natural products are essential sources of small-molecule antitumor drugs, some can exert substantial toxicities, limiting their clinical utility. Anthraquinone-fused enediyne natural products are remarkably potent antitumor drug candidates, and uncialamycin and tiancimycin (TNM) A are under development as antibody-drug conjugates. Herein, a novel drug delivery system is introduced for TNM A using anti-human epidermal growth factor receptor 2 (HER2) immunoliposomes (ILs). Trastuzumab-coated TNM A-loaded ILs (HER2-TNM A-ILs) is engineered with an average particle size of 182.8 ± 2.1 nm and a zeta potential of 1.75 ± 0.12 mV. Compared with liposomes lacking trastuzumab, HER2-TNM A-ILs exhibited selective toxicity against HER2-positive KPL-4 and SKBR3 cells. Coumarin-6, a fluorescent TNM A surrogate, is encapsulated within anti-HER2 ILs; the resultant ILs have enhanced cellular uptake in KPL-4 and SKBR3 cells when compared with control liposomes. Furthermore, ILs loaded with more Cy5.5 accumulated in KPL-4 mouse tumors. A single HER2-TNM A-IL dose (0.02 mg kg-1) suppressed the growth of HER2-positive KPL-4 mouse tumors without apparent toxicity. This study not only provides a straightforward method for the effective delivery of TNM A against HER2-positive breast tumors but also underscores the potential of IL-based drug delivery systems when employing highly potent cytotoxins as payloads.

Unveiling the hidden role of extracellular vesicles in brain metastases: a comprehensive review

Background

Extracellular vesicles (EVs) are small, transparent vesicles that can be found in various biological fluids and are derived from the amplification of cell membranes. Recent studies have increasingly demonstrated that EVs play a crucial regulatory role in tumorigenesis and development, including the progression of metastatic tumors in distant organs. Brain metastases (BMs) are highly prevalent in patients with lung cancer, breast cancer, and melanoma, and patients often experience serious complications and are often associated with a poor prognosis. The immune microenvironment of brain metastases was different from that of the primary tumor. Nevertheless, the existing review on the role and therapeutic potential of EVs in immune microenvironment of BMs is relatively limited.

Main body

This review provides a comprehensive analysis of the published research literature, summarizing the vital role of EVs in BMs. Studies have demonstrated that EVs participate in the regulation of the BMs immune microenvironment, exemplified by their ability to modify the permeability of the blood-brain barrier, change immune cell infiltration, and activate associated cells for promoting tumor cell survival and proliferation. Furthermore, EVs have the potential to serve as biomarkers for disease surveillance and prediction of BMs.

Conclusion

Overall, EVs play a key role in the regulation of the immune microenvironment of brain metastasis and are expected to make advances in immunotherapy and disease diagnosis. Future studies will help reveal the specific mechanisms of EVs in brain metastases and use them as new therapeutic strategies.

Targeting Strategies for Site-Specific mRNA Delivery

mRNA therapeutics hold great promise for disease treatment, yet a key challenge lies in achieving site-specific mRNA delivery to maximize therapeutic efficacy while minimizing off-target side effects. This viewpoint delves into multiple complementary targeting strategies to achieve precise site-specific mRNA delivery, covering topics of administration routes, passive targeting, and active targeting. It highlights the critical importance of rationally designed nanocarriers for obtaining desired therapeutic effects and accelerating the clinical translation of mRNA therapeutics.

Advances and Challenges in Interventional Immuno-Oncology Locoregional Therapies

Interventional immuno-oncology is making strides in locoregional therapies to address complex tumor microenvironments. Long-standing interventional radiology cancer therapies, such as tumor ablation and embolization, are being recharacterized in the context of immunotherapy. Intratumoral injections, such as those of genetically engineered or unaltered viruses, and the delivery of immune cells, antibodies, proteins, or cytokines into targeted tumors, along with advancements in delivery techniques, have produced promising results in preliminary studies, indicating their antitumor effectiveness. Emerging strategies using DNA scaffolding, polysaccharides, glycan, chitosan, and natural products are also showing promise in targeted cancer therapy. The future of interventional immuno-oncology lies in personalized immunotherapies that capitalize on individual immune profiles and tumor characteristics, along with the exploration of combination therapies. This study will review various interventional immuno-oncology strategies and emerging technologies to enhance delivery of therapeutics and response to immunotherapy.

Development of immunoliposomes containing cytotoxic gold payloads against HER2-positive breast cancers

Overexpression of the human epidermal growth factor receptor 2 (HER2) is found in 20-30% of breast cancer tumors (HER2-positive breast cancers) and is associated with more aggressive onset of disease, higher recurrence rate and increased mortality. Monoclonal antibodies (mAb) like trastuzumab and pertuzumab in combination with chemotherapeutics, and trastuzumab-based antibody drug conjugates (ADCs) are used in the clinic to treat these cancers. An alternative targeted strategy (not yet in clinical use) is the encapsulation of chemotherapeutic drugs in immunoliposomes. Such systems may not only facilitate targeted delivery to the tumor and improve intracellular penetration, but also override some of the resistance developed by tumors in response to cytotoxic loads. As a supplement to classical chemotherapeutics (based on organic compounds and conventional platinum-based derivatives), gold compounds are emerging as potential anticancer agents due to their high cytotoxicity and capacity for immunogenic cell death. Here, we describe the development of immunoliposomes functionalized with trastuzumab and pertuzumab; containing simple gold(i) neutral compounds ([AuCl(PR3)] (PR3 = PPh3 (1), PEt3 (2))) generated by the thin-film method to afford Lipo-1-Lipo-2. Trastuzumab and pertuzumab were engrafted onto these liposomes to generate gold-based immunoliposomes (Immunolipo-Tras-1, Immunolipo-Tras-2, Immunolipo-Per-1, Immunolipo-Per-2). We have characterized all liposomal formulations and demonstrated that the immunoliposomes (190 nm) are stable, have high binding affinity for HER2, and display selective cytotoxicity towards HER2-positive breast cancer cell lines. Trastuzumab-based immunoliposomes of a smaller size (100 nm) - encapsulating [AuCl(PEt3)] (2) - have been generated by an extrusion homogenization method. These optimized immunoliposomes (Opt-Immunolipo-Tras-2) have a trastuzumab engraftment efficiency, encapsulation efficiency for 2, and affinity for HER-2 similar to the immunoliposomes obtained by sonication (Immunolipo-Tras-2). While the amount of Au encapsulated is slightly lower, they display almost identical cytotoxicity and selectivity profiles. Moreover, the fluorescently-labeled phosphane drug [AuCl(PPh2-BODIPY)] (3) was encapsulated in both larger (Immunolipo-Tras-3) and smaller (Opt-Immunolipo-Tras-3) immunoliposomes and used to visualize the intracellular localization of the payload. Fluorescent imaging studies found that Opt-Immunolipo-Tras-3 accumulates in the cells more than 3 and that the unencapsulated payload accumulates primarily in lysosomes, while targeted liposomal 3 localizes in mitochondria and ER, hinting at different possibilities for modes of action.

Synergistic vesicle-vector systems for targeted delivery

With the immense progress in drug delivery systems (DDS) and the rise of nanotechnology, challenges such as target specificity remain. The vesicle-vector system (VVS) is a delivery system that uses lipid-based vesicles as vectors for a targeted drug delivery. When modified with target-probing materials, these vesicles become powerful vectors for drug delivery with high target specificity. In this review, we discuss three general types of VVS based on different modification strategies: (1) vesicle-probes; (2) vesicle-vesicles; and (3) genetically engineered vesicles. The synthesis of each VVS type and their corresponding properties that are advantageous for targeted drug delivery, are also highlighted. The applications, challenges, and limitations of VVS are briefly examined. Finally, we share a number of insights and perspectives regarding the future of VVS as a targeted drug delivery system at the nanoscale.

Recent Advances in Biomedical Nanotechnology Related to Natural Products

Natural product processing via nanotechnology has opened the door to innovative and significant applications in medical fields. On one hand, plants-derived bioactive ingredients such as phenols, pentacyclic triterpenes and flavonoids exhibit significant pharmacological activities, on another hand, most of them are hydrophobic in nature, posing challenges to their use. To overcome this issue, nanoencapsulation technology is employed to encapsulate these lipophilic compounds and enhance their bioavailability. In this regard, various nano-sized vehicles, including degradable functional polymer organic compounds, mesoporous silicon or carbon materials, offer superior stability and retention for bioactive ingredients against decomposition and loss during delivery as well as sustained release. On the other hand, some naturally occurring polymers, lipids and even microorganisms, which constitute a significant portion of Earth's biomass, show promising potential for biomedical applications as well. Through nano-processing, these natural products can be developed into nano-delivery systems with desirable characteristics for encapsulation a wide range of bioactive components and therapeutic agents, facilitating in vivo drug transport. Beyond the presentation of the most recent nanoencapsulation and nano-processing advancements with formulations mainly based on natural products, this review emphasizes the importance of their physicochemical properties at the nanoscale and their potential in disease therapy.

Unleashing the Potential: Designing Antibody-Targeted Lipid Nanoparticles for Industrial Applications with CMC Considerations and Clinical Outlook

Antibody-targeted lipid nanoparticles (Ab-LNPs) are rapidly gaining traction as multifaceted platforms in precision medicine, adept at delivering a diverse array of therapeutic agents, including nucleic acids and small molecules. This review provides an incisive overview of the latest developments in the field of Ab-LNP technology, with a special emphasis on pivotal design aspects such as antibody engineering, bioconjugation strategies, and advanced formulation techniques. Furthermore, it addresses critical chemistry, manufacturing, and controls (CMC) considerations and thoroughly examines the in vivo dynamics of Ab-LNPs, underscoring their promising potential for clinical application. By seamlessly blending scientific advancements with practical industrial perspectives, this review casts a spotlight on the burgeoning role of Ab-LNPs as an innovative and potent tool in the realm of targeted drug delivery.

Lipid-Based Nanotechnology: Liposome

Over the past several decades, liposomes have been extensively developed and used for various clinical applications such as in pharmaceutical, cosmetic, and dietetic fields, due to its versatility, biocompatibility, and biodegradability, as well as the ability to enhance the therapeutic index of free drugs. However, some challenges remain unsolved, including liposome premature leakage, manufacturing irreproducibility, and limited translation success. This article reviews various aspects of liposomes, including its advantages, major compositions, and common preparation techniques, and discusses present U.S. FDA-approved, clinical, and preclinical liposomal nanotherapeutics for treating and preventing a variety of human diseases. In addition, we summarize the significance of and challenges in liposome-enabled nanotherapeutic development and hope it provides the fundamental knowledge and concepts about liposomes and their applications and contributions in contemporary pharmaceutical advancement.

Multiphysics-Informed Pharmacokinetic Modeling of Systemic Exposure of Intramuscularly Injected LNPs

Lipid nanoparticle (LNP) constructs have been widely developed for gene therapy delivery. Understanding local absorption and presystemic clearance kinetics of LNPs, however, remains limited. This subsequently restrains the prediction and assessment of the systemic exposure of locally injected LNPs. As such, a multiscale computational approach was developed by integrating multiphysics simulation of intramuscular absorption kinetics of LNPs with whole-body pharmacokinetics modeling, bridged by a presystemic lymphatic kinetic model. The overall framework was enabled by utilizing physiological parameters obtained from the literature and drug-related parameters derived from experiments. The multiscale modeling and simulation approach predicted the systemic exposure of LNPs administered intramuscularly, with a high degree of agreement between the predicted and the experimental data. Sensitivity analyses revealed that the local absorption rate, pinocytosis presystemic clearance rate, and lymph flow rate of the presystemic lymphatic compartment had the most significant impacts on Cmax. The study yielded refreshing perspectives on estimating systemic exposures of locally injected LNPs and their safety and effectiveness.

Cellular Trafficking of Nanotechnology-Mediated mRNA Delivery

Messenger RNA (mRNA)-based therapy has emerged as a powerful, safe, and rapidly scalable therapeutic approach that involves technologies for both mRNA itself and the delivery vehicle. Although there are some unique challenges for different applications of mRNA therapy, a common challenge for all mRNA therapeutics is the transport of mRNA into the target cell cytoplasm for sufficient protein expression. This review is focused on the behaviors at the cellular level of nanotechnology-mediated mRNA delivery systems, which have not been comprehensively reviewed yet. First, the four main therapeutic applications of mRNA are introduced, including immunotherapy, protein replacement therapy, genome editing, and cellular reprogramming. Second, common types of mRNA cargos and mRNA delivery systems are summarized. Third, strategies to enhance mRNA delivery efficiency during the cellular trafficking process are highlighted, including accumulation to the cell, internalization into the cell, endosomal escape, release of mRNA from the nanocarrier, and translation of mRNA into protein. Finally, the challenges and opportunities for the development of nanotechnology-mediated mRNA delivery systems are presented. This review can provide new insights into the future fabrication of mRNA nanocarriers with desirable cellular trafficking performance.

Nanocarrier based active targeting strategies against erythrocytic stage of malaria

The Global Technical Strategy for Malaria 2016-2030 aims to achieve a 90% reduction in malaria cases, and strategic planning and execution are crucial for accomplishing this target. This review aims to understand the complex interaction between erythrocytic receptors and parasites and to use this knowledge to actively target the erythrocytic stage of malaria. The review provides insight into the malaria life cycle, which involves various receptors such as glycophorin A, B, C, and D (GPA/B/C/D), complement receptor 1, basigin, semaphorin 7a, Band 3/ GPA, Kx, and heparan sulfate proteoglycan for parasite cellular binding and ingress in the erythrocytic and exo-erythrocytic stages. Synthetic peptides mimicking P. falciparum receptor binding ligands, human serum albumin, chondroitin sulfate, synthetic polymers, and lipids have been utilized as ligands and decorated onto nanocarriers for specific targeting to parasite-infected erythrocytes. The need of the hour for treatment and prophylaxis against malaria is a broadened horizon that includes multiple targeting strategies against the entry, proliferation, and transmission stages of the parasite. Platform technologies with established pre-clinical safety and efficacy should be translated into clinical evaluation and formulation scale-up. Future development should be directed towards nanovaccines as proactive tools against malaria infection.

Therapeutic Antibodies in Medicine

Antibody engineering has developed into a wide-reaching field, impacting a multitude of industries, most notably healthcare and diagnostics. The seminal work on developing the first monoclonal antibody four decades ago has witnessed exponential growth in the last 10-15 years, where regulators have approved monoclonal antibodies as therapeutics and for several diagnostic applications, including the remarkable attention it garnered during the pandemic. In recent years, antibodies have become the fastest-growing class of biological drugs approved for the treatment of a wide range of diseases, from cancer to autoimmune conditions. This review discusses the field of therapeutic antibodies as it stands today. It summarizes and outlines the clinical relevance and application of therapeutic antibodies in treating a landscape of diseases in different disciplines of medicine. It discusses the nomenclature, various approaches to antibody therapies, and the evolution of antibody therapeutics. It also discusses the risk profile and adverse immune reactions associated with the antibodies and sheds light on future applications and perspectives in antibody drug discovery.

Multiphysics modeling and simulation of local transport and absorption kinetics of intramuscularly injected lipids nanoparticles

Recent clinical applications of mRNA vaccines highlight the critical role of drug delivery, especially when using lipid nanoparticles (LNPs) as the carrier for genetic payloads. However, kinetic and transport mechanisms for locally injected LNPs, such as lymphatic or cellular uptake and drug release, remain poorly understood. Herein, we developed a bottom-up multiphysics computational model to simulate the injection and absorption processes of LNPs in muscular tissues. Our purpose was to seek underlying connections between formulation attributes and local exposure kinetics of LNPs and the delivered drug. We were also interested in modeling the absorption kinetics from the local injection site to the systemic circulation. In our model, the tissue was treated as the homogeneous, poroelastic medium in which vascular and lymphatic vessel densities are considered. Tissue deformation and interstitial fluid flow (modeled using Darcy's Law) were also implemented. Transport of LNPs was described based on diffusion and advection; local disintegration and cellular uptake were also integrated. Sensitivity analyses of LNP and drug properties and tissue attributes were conducted using the simulation model. It was found that intrinsic tissue porosity and lymphatic vessel density affect the local transport kinetics; diffusivity, lymphatic permeability, and intracellular update kinetics also play critical roles. Simulated results were commensurate with experimental observations. This study could shed light on the development of LNP formulations and enable further development of whole-body pharmacokinetic models.

Multi-targeted immunotherapeutics to treat B cell malignancies

The concept of multi-targeted immunotherapeutic systems has propelled the field of cancer immunotherapy into an exciting new era. Multi-effector molecules can be designed to engage with, and alter, the patient's immune system in a plethora of ways. The outcomes can vary from effector cell recruitment and activation upon recognition of a cancer cell, to a multipronged immune checkpoint blockade strategy disallowing evasion of the cancer cells by immune cells, or to direct cancer cell death upon engaging multiple cell surface receptors simultaneously. Here, we review the field of multi-specific immunotherapeutics implemented to treat B cell malignancies. The mechanistically diverse strategies are outlined and discussed; common B cell receptor antigen targeting strategies are outlined and summarized; and the challenges of the field are presented along with optimistic insights for the future.

The Dawn of a New Era: Targeting the "Undruggables" with Antibody-Based Therapeutics

The high selectivity and affinity of antibodies toward their antigens have made them a highly valuable tool in disease therapy, diagnosis, and basic research. A plethora of chemical and genetic approaches have been devised to make antibodies accessible to more "undruggable" targets and equipped with new functions of illustrating or regulating biological processes more precisely. In this Review, in addition to introducing how naked antibodies and various antibody conjugates (such as antibody-drug conjugates, antibody-oligonucleotide conjugates, antibody-enzyme conjugates, etc.) work in therapeutic applications, special attention has been paid to how chemistry tools have helped to optimize the therapeutic outcome (i.e., with enhanced efficacy and reduced side effects) or facilitate the multifunctionalization of antibodies, with a focus on emerging fields such as targeted protein degradation, real-time live-cell imaging, catalytic labeling or decaging with spatiotemporal control as well as the engagement of antibodies inside cells. With advances in modern chemistry and biotechnology, well-designed antibodies and their derivatives via size miniaturization or multifunctionalization together with efficient delivery systems have emerged, which have gradually improved our understanding of important biological processes and paved the way to pursue novel targets for potential treatments of various diseases.

Triple targeting host-guest drug delivery system based on lactose-modified azocalix[4]arene for tumor ablation

Host-guest drug delivery systems (HGDDSs) have been studied in an effort to modify the characteristics of therapeutic agents through noncovalent interactions, reduce toxic side effects and improve therapeutic effects. However, it is still an important task to continuously improve the targeting ability of HGDDSs, which is conducive to the development of precision medicine. Herein, we utilize the lactose-modified azocalix[4]arene (LacAC4A) as a triple targeting drug carrier customized for antitumor purposes. LacAC4A integrates three targeting features, passive targeting through the enhancing permeability and retention effect, active targeting by the interactions of lactose and the asialoglycoprotein receptors on the surface of tumor cells, and stimuli-responsive targeting via the reduction of the azo group under a hypoxia microenvironment. After loading doxorubicin (DOX) in LacAC4A, the supramolecular nanoformulation DOX@LacAC4A clearly showed the effective suppression of tumor growth through in vivo experiments. LacAC4A can achieve effective targeting, rapid release, and improve drug bioavailability. This design principle will provide a new material for drug delivery systems.

A pH-responsive liposomal nanoplatform for co-delivery of a Pt(IV) prodrug and cinnamaldehyde for effective tumor therapy

Introduction: The tumor microenvironment (TME) is mainly characterized by abnormally elevated intracellular redox levels and excessive oxidative stress. However, the balance of the TME is also very fragile and susceptible to be disturbed by external factors. Therefore, several researchers are now focusing on intervening in redox processes as a therapeutic strategy to treat tumors. Here, we have developed a liposomal drug delivery platform that can load a Pt(IV) prodrug (DSCP) and cinnamaldehyde (CA) into a pH-responsive liposome to enrich more drugs in the tumor region for better therapeutic efficacy through enhanced permeability and retention effect. Methods: Using the glutathione-depleting properties of DSCP together with the ROS-generating properties of cisplatin and CA, we synergistically altered ROS levels in the tumor microenvironment to damage tumor cells and achieve anti-tumor effects in vitro. Results: A liposome loaded with DSCP and CA was successfully established, and this liposome effectively increased the level of ROS in the tumor microenvironment and achieved effective killing of tumor cells in vitro. Conclusion: In this study, novel liposomal nanodrugs loaded with DSCP and CA provided a synergistic strategy between conventional chemotherapy and disruption of TME redox homeostasis, leading to a significant increase in antitumor effects in vitro.

Holdase/Foldase Mimetic Nanochaperone Improves Antibody-Based Cancer Immunotherapy

Despite unprecedented successes of antibody-based cancer immunotherapy, the serious side effects and rapid clearance following systemic administration remain big challenges to realize its full potential. At the same time, combination immunotherapy using multiple antibodies has shown particularly promising in cancer treatment. It is noticed that the working mechanisms of natural holdase and foldase chaperone are desirable to overcome the limitations of therapeutic antibodies. Holdase chaperone stabilizes unfolded client and prevents it from activation and degradation, while foldase chaperone assists unfolded client to its native state to function. Here a holdase/foldase mimetic nanochaperone (H/F-nChap) to co-delivery two types of monoclonal antibodies (mAbs), αCD16 and αPDL1, and resiquimod (R848) is developed, which significantly improves cancer immunotherapy. The H/F-nChap presents holdase activity in blood and normal tissues that hides and protects mAbs from unnecessary targeted activation and degradation, thereby prolonging blood circulation and reducing immunotoxicity in vivo. Furthermore, H/F-nChap switches to foldase activity in the tumor microenvironment that exposes mAbs and releases R848 to enhance the engagement between NK cells and tumor cells and promote immune activation, respectively. The H/F-nChap represents a strategy for safe and spatiotemporal delivery of multiple mAbs, providing a promising platform for improved cancer immunotherapy.

Delivering on the promise of protein degraders

Over the past 3 years, the first bivalent protein degraders intentionally designed for targeted protein degradation (TPD) have advanced to clinical trials, with an initial focus on established targets. Most of these clinical candidates are designed for oral administration, and many discovery efforts appear to be similarly focused. As we look towards the future, we propose that an oral-centric discovery paradigm will overly constrain the chemical designs that are considered and limit the potential to drug novel targets. In this Perspective, we summarize the current state of the bivalent degrader modality and propose three categories of degrader designs, based on their likely route of administration and requirement for drug delivery technologies. We then describe a vision for how parenteral drug delivery, implemented early in research and supported by pharmacokinetic-pharmacodynamic modelling, can enable exploration of a broader drug design space, expand the scope of accessible targets and deliver on the promise of protein degraders as a therapeutic modality.

bioTCIs: Middle-to-Macro Biomolecular Targeted Covalent Inhibitors Possessing Both Semi-Permanent Drug Action and Stringent Target Specificity as Potential Antibody Replacements

Monoclonal antibody therapies targeting immuno-modulatory targets such as checkpoint proteins, chemokines, and cytokines have made significant impact in several areas, including cancer, inflammatory disease, and infection. However, antibodies are complex biologics with well-known limitations, including high cost for development and production, immunogenicity, a limited shelf-life because of aggregation, denaturation, and fragmentation of the large protein. Drug modalities such as peptides and nucleic acid aptamers showing high-affinity and highly selective interaction with the target protein have been proposed alternatives to therapeutic antibodies. The fundamental limitation of short in vivo half-life has prevented the wide acceptance of these alternatives. Covalent drugs, also known as targeted covalent inhibitors (TCIs), form permanent bonds to target proteins and, in theory, eternally exert the drug action, circumventing the pharmacokinetic limitation of other antibody alternatives. The TCI drug platform, too, has been slow in gaining acceptance because of its potential prolonged side-effect from off-target covalent binding. To avoid the potential risks of irreversible adverse drug effects from off-target conjugation, the TCI modality is broadening from the conventional small molecules to larger biomolecules possessing desirable properties (e.g., hydrolysis resistance, drug-action reversal, unique pharmacokinetics, stringent target specificity, and inhibition of protein-protein interactions). Here, we review the historical development of the TCI made of bio-oligomers/polymers (i.e., peptide-, protein-, or nucleic-acid-type) obtained by rational design and combinatorial screening. The structural optimization of the reactive warheads and incorporation into the targeted biomolecules enabling a highly selective covalent interaction between the TCI and the target protein is discussed. Through this review, we hope to highlight the middle to macro-molecular TCI platform as a realistic replacement for the antibody.

One-Step Formation of Targeted Liposomes in a Versatile Microfluidic Mixing Device

Targeted liposomes, as a promising carrier, have received tremendous attention in COVID-19 vaccines, molecular imaging, and cancer treatment, due to their enhanced cellular uptake and payload accumulation at target sites. However, the conventional methods for preparing targeted liposomes still suffer from limitations, including complex operation, time-consuming, and poor reproducibility. Herein, a facile and scalable strategy is developed for one-step construction of targeted liposomes using a versatile microfluidic mixing device (MMD). The engineered MMD provides an advanced synthesis platform for multifunctional liposome with high production rate and controllability. To validate the method, a programmed death-ligand 1 (PD-L1)-targeting aptamer modified indocyanine green (ICG)-liposome (Apt-ICG@Lip) is successfully constructed via the MMD. ICG and the PD-L1-targeting aptamer are used as model drug and targeting moiety, respectively. The Apt-ICG@Lip has high encapsulation efficiency (89.9 ± 1.4%) and small mean diameter (129.16 ± 5.48 nm). In vivo studies (PD-L1-expressing tumor models) show that Apt-ICG@Lip can realize PD-L1 targeted photoacoustic imaging, fluorescence imaging, and photothermal therapy. To verify the versatility of this approach, various targeted liposomes with different functions are further prepared and investigated. These experimental results demonstrate that this method is concise, efficient, and scalable to prepare multifunctional targeted liposomal nanoplatforms for molecular imaging and disease theranostics.

Sticking the Landing: Enhancing Liposomal Cell Delivery using Reversible Covalent Chemistry and Caged Targeting Groups

Liposomes are highly effective nanocarriers for encapsulating and delivering a wide range of therapeutic cargo. While advancements in liposome design have improved several pharmacological characteristics, an important area that would benefit from further progress involves cellular targeting and entry. In this concept article, we will focus on recent progress utilizing strategies including reversible covalent bonding and caging groups to activate liposomal cell entry. These approaches take advantage of advancements that have been made in complementary fields including molecular sensing and chemical biology and direct this technology toward controlling liposome cell delivery properties. The decoration of liposomes with groups including boronic acids and cyclic disulfides is presented as a means for driving delivery through reaction with functional groups on cell surfaces. Additionally, caging groups can be exploited to activate cell delivery only upon encountering a target stimulus. These approaches provide promising new avenues for controlling cell delivery in the development of next-generation liposomal therapeutic nanocarriers.

Therapeutic monoclonal antibodies with a focus on hereditary angioedema

Monoclonal antibodies (mAbs) have been shown to be effective and generally safe across a continually expanding list of therapeutic areas. We describe the advantages and limitations of mAbs as a therapeutic option compared with small molecules. Specifically, we discuss a novel mAb in the treatment of hereditary angioedema (HAE), a rare and potentially life-threatening condition characterized by recurrent unpredictable swelling attacks. HAE is mediated by dysregulation of plasma kallikrein activity leading to overproduction of bradykinin. Current prophylactic treatment for HAE includes androgens or replacement of the endogenous plasma kallikrein inhibitor, C1 inhibitor. However, there remains an unmet need for an effective, less burdensome treatment option. Lanadelumab is a fully human mAb targeting plasma kallikrein. Results from clinical trials, including a pivotal Phase 3 study and its ensuing open-label extension study, demonstrated that lanadelumab is associated with few treatment-related adverse events and reduced the rate of HAE attacks. This novel treatment option has the potential to significantly improve the lives of patients with HAE.

Nanomaterials targeting macrophages in sepsis: A promising approach for sepsis management

Sepsis is a life-threatening organ dysfunction resulting from dysregulated host responses to infection. Macrophages play significant roles in host against pathogens and the immunopathogenesis of sepsis, such as phagocytosis of pathogens, secretion of cytokines, and phenotype reprogramming. However, the rapid progression of sepsis impairs macrophage function, and conventional antimicrobial and supportive treatment are not sufficient to restore dysregulated macrophages roles. Nanoparticles own unique physicochemical properties, surface functions, localized surface plasmon resonance phenomenon, passive targeting in vivo, good biocompatibility and biodegradability, are accessible for biomedical applications. Once into the body, NPs are recognized by host immune system. Macrophages are phagocytes in innate immunity dedicated to the recognition of foreign substances, including nanoparticles, with which an immune response subsequently occurs. Various design strategies, such as surface functionalization, have been implemented to manipulate the recognition of nanoparticles by monocytes/macrophages, and engulfed by them to regulate their function in sepsis, compensating for the shortcomings of sepsis traditional methods. The review summarizes the mechanism of nanomaterials targeting macrophages and recent advances in nanomedicine targeting macrophages in sepsis, which provides good insight for exploring macrophage-based nano-management in sepsis.

Nucleic Acid Delivery to the Vascular Endothelium

This Review examines the state-of-the-art in the delivery of nucleic acid therapies that are directed to the vascular endothelium. First, we review the most important homeostatic functions and properties of the vascular endothelium and summarize the nucleic acid tools that are currently available for gene therapy and nucleic acid delivery. Second, we consider the opportunities available with the endothelium as a therapeutic target and the experimental models that exist to evaluate the potential of those opportunities. Finally, we review the progress to date from investigations that are directly targeting the vascular endothelium: for vascular disease, for peri-transplant therapy, for angiogenic therapies, for pulmonary endothelial disease, and for the blood-brain barrier, ending with a summary of the future outlook in this field.

Site-Selective Lysine Acetylation of Human Immunoglobulin G for Immunoliposomes and Bispecific Antibody Complexes

Site-selective acetylation of a single lysine residue in a protein that reaches a lysine acetyltransferase's accuracy, precision, and reliability is challenging. Here, we report a peptide-guided, proximity-driven group transfer reaction that acetylates a single lysine residue, Lys 248, of the fragment crystallizable region (Fc region) in the heavy chain of the human Immunoglobulin G (IgG). An Fc-interacting peptide bound with the Fc domain and positioned a phenolic ester close to Lys 248, which induced a nucleophilic reaction and resulted in the transfer of an acetyl group to Lys 248. The acetylation reaction proceeded to a decent yield under the physiological condition without the need for deglycosylation, unnatural amino acids, or catalysts. Along with acetylation, functional moieties such as azide, alkyne, fluorescent molecules, or biotin could also be site-selectively installed on Lys 248, allowing IgG's further derivatization. We then synthesized an antibody-lipid conjugate and constructed antibody-conjugated liposomes (immunoliposomes), targeting HER2-positive (HER2+) cancer cells. We also built a bispecific antibody complex (bsAbC) covalently linking an anti-HER2 antibody and an anti-CD3 antibody. The bsAbC showed in vitro effector-cell-mediated cytotoxicity at nanomolar concentrations. Compared with bispecific antibodies (bsAbs), bsAbCs are constructed based on native IgGs and contain two antigen-binding sites to each antigen, twice that of bsAbs. Altogether, this work reports a method of site-selective acetylation of native antibodies, highlights a facile way of site-selective IgG functionalization, and underscores the potential of bsAbCs in cancer immunotherapy.

Modeling Polyzwitterion-Based Drug Delivery Platforms: A Perspective of the Current State-of-the-Art and Beyond

Drug delivery platforms are anticipated to have biocompatible and bioinert surfaces. PEGylation of drug carriers is the most approved method since it improves water solubility and colloid stability and decreases the drug vehicles’ interactions with blood components. Although this approach extends their biocompatibility, biorecognition mechanisms prevent them from biodistribution and thus efficient drug transfer. Recent studies have shown (poly)zwitterions to be alternatives for PEG with superior biocompatibility. (Poly)zwitterions are super hydrophilic, mainly stimuli-responsive, easy to functionalize and they display an extremely low protein adsorption and long biodistribution time. These unique characteristics make them already promising candidates as drug delivery carriers. Furthermore, since they have highly dense charged groups with opposite signs, (poly)zwitterions are intensely hydrated under physiological conditions. This exceptional hydration potential makes them ideal for the design of therapeutic vehicles with antifouling capability, i.e., preventing undesired sorption of biologics from the human body in the drug delivery vehicle. Therefore, (poly)zwitterionic materials have been broadly applied in stimuli-responsive “intelligent” drug delivery systems as well as tumor-targeting carriers because of their excellent biocompatibility, low cytotoxicity, insignificant immunogenicity, high stability, and long circulation time. To tailor (poly)zwitterionic drug vehicles, an interpretation of the structural and stimuli-responsive behavior of this type of polymer is essential. To this end, a direct study of molecular-level interactions, orientations, configurations, and physicochemical properties of (poly)zwitterions is required, which can be achieved via molecular modeling, which has become an influential tool for discovering new materials and understanding diverse material phenomena. As the essential bridge between science and engineering, molecular simulations enable the fundamental understanding of the encapsulation and release behavior of intelligent drug-loaded (poly)zwitterion nanoparticles and can help us to systematically design their next generations. When combined with experiments, modeling can make quantitative predictions. This perspective article aims to illustrate key recent developments in (poly)zwitterion-based drug delivery systems. We summarize how to use predictive multiscale molecular modeling techniques to successfully boost the development of intelligent multifunctional (poly)zwitterions-based systems.

The effects of protein corona on in vivo fate of nanocarriers

With the emerging advances in utilizing nanocarriers for biomedical applications, a molecular-level understanding of the in vivo fate of nanocarriers is necessary. After administration into human fluids, nanocarriers can attract proteins onto their surfaces, forming an assembled adsorption layer called protein corona (PC). The formed PC can influence the physicochemical properties and subsequently determine nanocarriers' biological behaviors. Therefore, an in-depth understanding of the features and effects of the PC on the nanocarriers' surface is the first and most important step towards controlling their in vivo fate. This review introduces fundamental knowledge such as the definition, formation, composition, conformation, and characterization of the PC, emphasizing the in vivo environmental factors that control the PC formation. The effect of PC on the physicochemical properties and thus biological behaviors of nanocarriers was then presented and thoroughly discussed. Finally, we proposed the design strategies available for engineering PC onto nanocarriers to manipulate them with the desired surface properties and achieve the best biomedical outcomes.

Quantification of Available Ligand Density on the Surface of Targeted Liposomal Nanomedicines at the Single-Particle Level

Active targeting has been hailed as one of the most promising strategies to further enhance the therapeutic efficacy of liposomal nanomedicines. Owing to the critical role of ligand density in mediating cellular uptake and the intrinsic heterogeneity of liposomal formulations, precise quantification of the surface ligand density on a single-particle basis is of fundamental importance. In this work, we report a method to simultaneously measure the particle size and the number of ligands on the same liposomal nanoparticles by nanoflow cytometry. Then the ligand density for each individual liposome can be determined. With an analysis rate up to 10 000 particles per minute, a statistically representative distribution of ligand density could be determined in minutes. By utilizing fluorescently labeled recombinant receptors as the detection probe against the conjugated ligands, only those available for cell targeting can be exclusively detected. The influence of ligand input, conjugation strategy, and the polyethylene glycol spacer length on the available ligand density of folate-modified liposomes was investigated. The correlation between the available ligand density and cell targeting capability was assessed in a quantitative perspective for liposomes modified with three different targeting moieties. The optimal ligand density was determined to be 0.5-2.0, 0.7, and 0.2 ligand per 100 nm² for folate-, transferrin-, and HER2-antibody-conjugated liposomes, respectively. These optimal values agreed well with the spike density of the natural counterparts, viruses. The as-developed approach is generally applicable to a wide range of active-targeting nanocarriers.

Tumor Tropic Delivery of Hyaluronic Acid-Poly (D,L-lactide-co-glycolide) Polymeric Micelles Using Mesenchymal Stem Cells for Glioma Therapy

Tumor penetration and the accumulation of nanomedicines are crucial challenges in solid tumor therapy. By taking advantage of the MSC tumor-tropic property, we developed a mesenchymal stem cell (MSC)-based drug delivery system in which paclitaxel (PTX)-encapsulating hyaluronic acid-poly (D,L-lactide-co-glycolide) polymeric micelles (PTX/HA-PLGA micelles) were loaded for glioma therapy. The results indicated that CD44 overexpressed on the surface of both MSCs and tumor cells not only improved PTX/HA-PLGA micelle loading in MSCs, but also promoted the drug transfer between MSCs and adjacent cancer cells. It was hypothesized that CD44-mediated transcytosis played a crucial role and allowed deep glioma penetration depending on sequential intra–intercellular delivery via endocytosis–exocytosis. MSC-micelles were able to infiltrate from normal brain parenchyma towards contralateral tumors and led to the eradication of glioma. The survival of orthotopic glioma-bearing rats was significantly extended. In conclusion, the MSC-based delivery of HA-PLGA micelles is a potential strategy for tumor-targeting drug delivery.

19 F MRI Nanotheranostics for Cancer Management: Progress and Prospects

Fluorine magnetic resonance imaging (¹⁹ F MRI) is a promising imaging technique for cancer diagnosis because of its excellent soft tissue resolution and deep tissue penetration, as well as the inherent high natural abundance, almost no endogenous interference, quantitative analysis, and wide chemical shift range of the ¹⁹ F nucleus. In recent years, scientists have synthesized various ¹⁹ F MRI contrast agents. By further integrating a wide variety of nanomaterials and cutting-edge construction strategies, magnetically equivalent ¹⁹ F atoms are super-loaded and maintain satisfactory relaxation efficiency to obtain high-intensity ¹⁹ F MRI signals. In this review, the nuclear magnetic resonance principle underlying ¹⁹ F MRI is first described. Then, the construction and performance of various fluorinated contrast agents are summarized. Finally, challenges and future prospects regarding the clinical translation of ¹⁹ F MRI nanoprobes are considered. This review will provide strategic guidance and panoramic expectations for designing new cancer theranostic regimens and realizing their clinical translation.

Stimuli-Responsive Drug Delivery Systems for the Diagnosis and Therapy of Lung Cancer

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer death worldwide. Numerous drugs have been developed to treat lung cancer patients in recent years, whereas most of these drugs have undesirable adverse effects due to nonspecific distribution in the body. To address this problem, stimuli-responsive drug delivery systems are imparted with unique characteristics and specifically deliver loaded drugs at lung cancer tissues on the basis of internal tumor microenvironment or external stimuli. This review summarized recent studies focusing on the smart carriers that could respond to light, ultrasound, pH, or enzyme, and provided a promising strategy for lung cancer therapy.

Near-Infrared Light-Activated Oxygen Generator a Multidynamic Photo-Nanoplatform for Effective Anti-Cutaneous Squamous Cell Carcinoma Treatment

Introduction

Nanophototherapy has emerged as a novel and promising therapeutic strategy for cancer treatment; however, its efficacy in dermatological tumors and precancerous lesions remains severely limited. This study aimed to use the gas-liquid injection technique to fully utilize the synergistic photodynamic therapy (PDT)/photothermal therapy (PTT) of nanomaterials to enhance the antitumor effect.

Methods

A novel oxygen-generating nanocomposite (TSL-IR820-CAT) was synthesized by encapsulating the photosensitizer IR820 and catalase (CAT) using a matrix encapsulation method based on thermosensitive liposomes (TSL).-The liquid injection technology enhances the treatment of cutaneous squamous cell carcinoma (cSCC). The combined PDT/PTT therapeutic effect of TSL-IR820-CAT on cSCC was investigated using in vivo and in vitro experiments.

Results

TSL-IR820-CAT, with good stability, efficient drug release, and photothermal conversion ability, was successfully developed. Nanoparticles injected through a needle-free syringe efficiently accumulate in the tumor tissue. As TSL-IR820-CAT was consumed by A431 cells, some of it localized to the mitochondria and produced oxygen to relieve hypoxia, thereby enhancing the efficacy of PDT. PDT/PTT combination therapy resulted in irreversible apoptosis and inhibited cSCC growth. TSL-IR820-CAT coupled with gas-liquid injection was free from apparent systemic side effects.

Conclusion

This article discusses new strategies and ideas for treating skin tumors and has significant application value.

Smart Lipid-Based Nanosystems for Therapeutic Immune Induction against Cancers: Perspectives and Outlooks

Cancer immunotherapy, a promising and widely applied mode of oncotherapy, makes use of immune stimulants and modulators to overcome the immune dysregulation present in cancer, and leverage the host's immune capacity to eliminate tumors. Although some success has been seen in this field, toxicity and weak immune induction remain challenges. Liposomal nanosystems, previously used as targeting agents, are increasingly functioning as immunotherapeutic vehicles, with potential for delivery of contents, immune induction, and synergistic drug packaging. These systems are tailorable, multifunctional, and smart. Liposomes may deliver various immune reagents including cytokines, specific T-cell receptors, antibody fragments, and immune checkpoint inhibitors, and also present a promising platform upon which personalized medicine approaches can be built, especially with preclinical and clinical potentials of liposomes often being frustrated by inter- and intrapatient variation. In this review, we show the potential of liposomes in cancer immunotherapy, as well as the methods for synthesis and in vivo progression thereof. Both preclinical and clinical studies are included to comprehensively illuminate prospects and challenges for future research and application.

Nanoplatforms for Sepsis Management: Rapid Detection/Warning, Pathogen Elimination and Restoring Immune Homeostasis

Sepsis, a highly life-threatening organ dysfunction caused by uncontrollable immune responses to infection, is a leading contributor to mortality in intensive care units. Sepsis-related deaths have been reported to account for 19.7% of all global deaths. However, no effective and specific therapeutic for clinical sepsis management is available due to the complex pathogenesis. Concurrently eliminating infections and restoring immune homeostasis are regarded as the core strategies to manage sepsis. Sophisticated nanoplatforms guided by supramolecular and medicinal chemistry, targeting infection and/or imbalanced immune responses, have emerged as potent tools to combat sepsis by supporting more accurate diagnosis and precision treatment. Nanoplatforms can overcome the barriers faced by clinical strategies, including delayed diagnosis, drug resistance and incapacity to manage immune disorders. Here, we present a comprehensive review highlighting the pathogenetic characteristics of sepsis and future therapeutic concepts, summarizing the progress of these well-designed nanoplatforms in sepsis management and discussing the ongoing challenges and perspectives regarding future potential therapies. Based on these state-of-the-art studies, this review will advance multidisciplinary collaboration and drive clinical translation to remedy sepsis.

An intelligent cell-selective polymersome-DM1 nanotoxin toward triple negative breast cancer

Antibody-drug conjugates (ADCs) are among the most significant advances in clinical cancer treatments, however, they are haunted with fundamental issues like low drug/antibody ratio (DAR), need of large amount of antibody, and complex chemistry. Targeted nanomedicines while offering a promising alternative to ADCs are afflicted with drug leakage and inferior cancer-specificity. Herein, we developed an intelligent cell-selective nanotoxin based on anti-CD44 antibody-polymersome-DM1 conjugates (aCD44-AP-DM1) for potent treatment of solid tumors. DM1 was simultaneously coupled to vesicular membrane via disulfide bonds during self-assembly and anti-CD44 antibody was facilely clicked onto polymersome surface, tailor-making an optimal aCD44-AP-DM1 with a controlled antibody density of 5.0, extraordinary DAR of 275, zero drug leakage and rapid reduction-responsive DM1 release. aCD44-AP-DM1 displayed a high specificity and exceptional cytotoxicity toward MDA-MB-231 triple negative breast cancer, SMMC-7721 hepatocellular carcinoma and A549 non-small cell lung cancer cells with half-maximal inhibitory concentrations (IC₅₀) of 21.4, 3.7 and 64.6 ng/mL, respectively, 3.6-47.2-fold exceeding non-targeted P-DM1. Intriguingly, the systemic administration of aCD44-AP-DM1 significantly suppressed subcutaneous MDA-MB-231 tumor xenografts in nude mice while intratumoral injection achieved complete tumor eradication in four out of five mice, without causing toxicity. This intelligent cell-selective nanotoxin has emerged as a better platform over ADCs for targeted cancer therapy.

Photothermal nanozyme-ignited Fenton reaction-independent ferroptosis for breast cancer therapy

Ferroptosis is a type of programmed cell death caused by the iron-dependent lipid hydroperoxide pathway and has attracted significant interest. However, Fenton reaction-dependent ferroptosis has shown unsatisfactory therapeutic effects in tumor therapy, mainly due to inadequate reaction conditions in the tumor microenvironment. Here, we report a new strategy for Fenton-independent pathway by employing photothermal nanozyme to overcome limitations of the low efficiency of Fenton reaction. Specifically, we used iron redox pair (Fe²⁺/Fe³⁺)-containing hollow mesoporous Prussian blue (HMPB) nanocubes as the iron sources to fabricate iron-loaded liposome (HMPB@Lip). HMPB@Lip not only exerts the photothermal therapy, but also functions as nanozyme catalyzing lipid peroxidation for ferroptosis therapy. Importantly, Fenton reaction-independent ferroptosis triggered by photothermal nanozyme achieved effective tumor ablation. Therefore, HMPB@Lip can be used as a potential multifunctional nanozyme for effective Fenton reaction-independent ferroptosis therapy.

Daratumumab Immunopolymersome-Enabled Safe and CD38-Targeted Chemotherapy and Depletion of Multiple Myeloma

Multiple myeloma (MM) is a second ranking hematological malignancy. Despite the fast advancement of new treatments such as bortezormib and daratumumab, MM patients remain incurable and tend to eventually become relapsed and drug-resistant. Development of novel therapies capable of depleting MM cells is strongly needed. Here, daratumumab immunopolymersomes carrying vincristine sulfate (Dar-IPs-VCR) are reported for safe and high-efficacy CD38-targeted chemotherapy and depletion of orthotopic MM in vivo. Dar-IPs-VCR made by postmodification via strain-promoted click reaction holds tailored antibody density (2.2, 4.4 to 8.7 Dar per IPs), superb stability, small size (43-49 nm), efficacious VCR loading, and glutathione-responsive VCR release. Dar_4.4 -IPs-VCR induces exceptional anti-MM activity with an IC₅₀ of 76 × 10^-12 m to CD38-positive LP-1 MM cells, 12- and 20-fold enhancement over nontargeted Ps-VCR and free VCR controls, respectively. Intriguingly, mice bearing orthotopic LP-1-Luc MM following four cycles of i.v. administration of Dar_4.4 -IPs-VCR at 0.25 mg VCR equiv. kg^-1 reveal complete depletion of LP-1-Luc cells, superior survival rate to all controls, and no body weight loss. The bone and histological analyses indicate bare bone and organ damage. Dar-IPs-VCR appears as a safe and targeted treatment for CD38-overexpressed hematological malignancies.

Surface Ligand Valency and Immunoliposome Binding: when More Is Not Always Better

PURPOSE

Nano-drug delivery systems are designed to contain surface ligands including antibodies for "active targeting". The number of ligands on each nanoparticle, known as the valency, is considered a critical determinant of the "targeting" property. We sought to understand the correlation between valency and binding properties using antibody conjugated liposomes, i.e. immunoliposomes (ILs), as the model.

METHODS

Anti-CD3 Fab containing a terminal cysteine residue were conjugated to DSPE-PEG-maleimide and incubated with preformed liposomes at 60°C. The un-incorporated antibodies were removed and the obtained ILs were characterized to contain in average 2-22 copies of anti-CD3 Fabs per liposome. The Biolayer Interferometry (BLI) probe surface was coated with various densities of CD3 epsilon&delta heterodimer (CD3D/E) to imitate different CD3 expression levels on target cells. The inference wavelength shifts upon anti-CD3 liposome binding were monitored and analyzed.

RESULTS

The data indicated ILs may bind either monovalently or multivalently, determined mainly by the surface ligand density rather than the ILs antibody valency. The ILs valency indeed correlated with the dissociation rate constant (K_off), but not with the association rate constant (K_on). Their binding capabilities also did not necessarily increase with the surface anti-CD3 valency.

CONCLUSION

We proposed a model for understanding the binding properties of ILs with different ligand valencies. The binding mode may change when the targeted surfaces had different antigen densities. The model should be important for the designing and optimization of active targeting drug delivery systems to fit different applications.

The emergence of imaging mass spectrometry in drug discovery and development: Making a difference by driving decision making

The pharmaceutical industry is a dynamic, science-driven business constantly under pressure to innovate and morph into a higher performing organization. Innovations can include the implementation of new technologies, adopting new scientific methods, changing the decision-making process, compressing timelines, or making changes to the organizational structure. The drivers for the constant focus on performance improvement are the high cost of R&D as well as the lengthy timelines required to deliver new medicines for unmet needs. Successful innovations are measured against both the quality and quantity of potential new medicines in the pipeline and the delivery to patients. In this special feature article, we share our collective experience implementing matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) technology as an innovative approach to better understand the tissue biodistribution of drugs in the early phases of drug discovery to establish pharmacokinetic-pharmacodynamic (PK-PD) relationships, as well as in the development phase to understand pharmacology, toxicology, and disease pathogenesis. In our experience, successful implementation of MALDI IMS in support of therapeutic programs can be measured by the impact IMS studies have on driving decision making in pipeline progression. This provides a direct quantifiable measurement of the return to the organization for the investment in IMS. We have included discussion not only on the technical merits of IMS study conduct but also the key elements of setting study objectives, building collaborations, data integration into the medicine progression milestones, and potential pitfalls when trying to establish IMS in the pharmaceutical arena. We categorized IMS study types into five groups that parallel pipeline progression from the earliest phases of discovery to late stages of preclinical development. We conclude the article with some perspectives on how we see MALDI IMS maintaining relevance and becoming further embedded as an essential tool in the constantly changing environment of the pharmaceutical industry.

Recent Advances in Liposomal-Based Anti-Inflammatory Therapy

Liposomes can be seen as ideal carriers for anti-inflammatory drugs as their ability to (passively) target sites of inflammation and release their content to inflammatory target cells enables them to increase local efficacy with only limited systemic exposure and adverse effects. Nonetheless, few liposomal formulations seem to reach the clinic. The current review provides an overview of the more recent innovations in liposomal treatment of rheumatoid arthritis, psoriasis, vascular inflammation, and transplantation. Cutting edge developments include the liposomal delivery of gene and RNA therapeutics and the use of hybrid systems where several liposomal bilayer features, or several drugs, are combined in a single formulation. The majority of the articles reviewed here focus on preclinical animal studies where proof-of-principle of an improved efficacy-safety ratio is observed when using liposomal formulations. A few clinical studies are included as well, which brings us to a discussion about the challenges of clinical translation of liposomal nanomedicines in the field of inflammatory diseases.

The Molecular Basis of COVID-19 Pathogenesis, Conventional and Nanomedicine Therapy

In late 2019, a new member of the Coronaviridae family, officially designated as "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2), emerged and spread rapidly. The Coronavirus Disease-19 (COVID-19) outbreak was accompanied by a high rate of morbidity and mortality worldwide and was declared a pandemic by the World Health Organization in March 2020. Within the Coronaviridae family, SARS-CoV-2 is considered to be the third most highly pathogenic virus that infects humans, following the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV). Four major mechanisms are thought to be involved in COVID-19 pathogenesis, including the activation of the renin-angiotensin system (RAS) signaling pathway, oxidative stress and cell death, cytokine storm, and endothelial dysfunction. Following virus entry and RAS activation, acute respiratory distress syndrome develops with an oxidative/nitrosative burst. The DNA damage induced by oxidative stress activates poly ADP-ribose polymerase-1 (PARP-1), viral macrodomain of non-structural protein 3, poly (ADP-ribose) glycohydrolase (PARG), and transient receptor potential melastatin type 2 (TRPM2) channel in a sequential manner which results in cell apoptosis or necrosis. In this review, blockers of angiotensin II receptor and/or PARP, PARG, and TRPM2, including vitamin D3, trehalose, tannins, flufenamic and mefenamic acid, and losartan, have been investigated for inhibiting RAS activation and quenching oxidative burst. Moreover, the application of organic and inorganic nanoparticles, including liposomes, dendrimers, quantum dots, and iron oxides, as therapeutic agents for SARS-CoV-2 were fully reviewed. In the present review, the clinical manifestations of COVID-19 are explained by focusing on molecular mechanisms. Potential therapeutic targets, including the RAS signaling pathway, PARP, PARG, and TRPM2, are also discussed in depth.

Targeted Delivery of Combination Therapeutics Using Monoclonal Antibody 2C5-Modified Immunoliposomes for Cancer Therapy

PURPOSE

To develop immunoliposomes modified with monoclonal cancer-specific antibody (mAb) 2C5 and co-loaded with a combination of two chemotherapeutics, in order to simultaneously target bulk cancer cells using paclitaxel and cancer stem cells (CSCs) using salinomycin to prevent cancer growth and metastases.

METHODS

Breast cancer cells (MDA-MB-231 and/or SK-BR-3) were chosen as models for all in vitro testing. Liposomes composed of natural phospholipids co-loaded with salinomycin and paclitaxel were prepared and physically characterized. Immunoliposomes modified with mAb 2C5 coupled to polymeric conjugate were prepared and characterized for specific targeting. Wound healing assay was performed using the combination of free drugs in vitro. In vitro studies on cellular interaction and uptake were followed by holographic imaging to study cell-killing, cell-division and proliferation inhibiting effects of the formulation. Ex-vivo study on hemolysis was investigated to check possible toxicity of the formulation.

RESULTS

Physical characterization of the liposomes showed stable nanoparticles of consistent and desirable size range (170-220 nm), zeta potential (-13 mV to - 20 mV), polydispersity indices (<0.2) and drug encapsulation efficiencies (~150 μg per ml for salinomycin, ~210 μg/ml for paclitaxel and 1:1 for combination drug loaded liposomes). Combination therapy strongly affected cancer cell proliferation as shown by significant diminishing of artificial gap closure at the wound site on MDA-MB-231 cells in culture using wound healing assay. Quantitation of changes in wound widths showed ~219 μm for drug combination, ~104 μm for only paclitaxel, and ~ 7 μm for only salinomycin treatments. Statistically significant increase in cellular interaction and specific uptake of the targeted drug co-loaded liposomal nanopreparation (p value ≤ 0.05) by MDA-MB-231 and SK-BR-3 cells confirmed the effectiveness of the approach. Holographic imaging using MDA-MB-231 cells produced visible increase in cell-killing, proliferation and division in vitro. Ex-vivo experimentation showed reduced hemolysis correlating with low toxicity in athymic nude mice model.

CONCLUSION

The results demonstrated the enhanced therapeutic efficacy of a combination of salinomycin and paclitaxel delivered by mAb 2C5-modified liposomal preparation in cancer therapy.

Construction of Surface-Modified Polydopamine Nanoparticles for Sequential Drug Release and Combined Chemo-Photothermal Cancer Therapy

Single chemotherapy often causes severe adverse effects and drug resistance to limit therapeutic efficacy. As a noninvasive approach, photothermal therapy (PTT) represents an attractive option for cancer therapy due to the benefits of remote control and precise treatment methods. Nanomedicines constructed with combined chemo-photothermal properties may exert synergistic effects and improved antitumor efficacy. In this study, we developed polydopamine (PDA)-coated nanoparticles grafted with folic acid (FA) and polyethylene glycol to transport doxorubicin (DOX) for targeted cancer therapy. The results showed that this delivery vehicle has a nanoscale particle size and narrow size distribution. No particle aggregation or significant drug leakage was observed during the stability test. This system presented excellent photothermal conversion capability under near-infrared light (NIR) laser irradiation due to the PDA layer covering. In vitro dissolution profiles demonstrated that sequential and triggered DOX release from nanoparticles was pH-, NIR irradiation-, and redox level-dependent and could be best fitted with the Ritger-Peppas equation. FA modification effectively promoted the intracellular uptake of nanoparticles by HepG2 cells and therefore significantly inhibited cell recovery and induced tumor cell apoptosis. Compared to the free DOX group, nanoparticles reduced the DOX concentration in the heart to avoid drug-related cardiotoxicity. More importantly, the in vivo antitumor efficacy results showed that compared with the single chemotherapy strategy, the nanoparticle group exerted combined and satisfactory tumor growth inhibition effects with good biocompatibility. In summary, this nanocarrier delivery system can organically combine chemotherapy and PTT to achieve effective and precise cancer treatment.

3D Culture Systems for Exploring Cancer Immunology

Simple Summary

To study any disease, researchers need convenient and relevant disease models. In cancer, the most commonly used models are two-dimensional (2D) culture models, which grow cells on hard, rigid, plastic surfaces, and mouse models. Cancer immunology is especially difficult to model because the immune system is exceedingly complex; it contains multiple types of cells, and each cell type has several subtypes and a spectrum of activation states. These many immune cell types interact with cancer cells and other components of the tumor, ultimately influencing disease outcomes. 2D culture methods fail to recapitulate these complex cellular interactions. Mouse models also suffer because the murine and human immune systems vary significantly. Three-dimensional (3D) culture systems therefore provide an alternative method to study cancer immunology and can fill the current gaps in available models. This review will describe common 3D culture models and how those models have been used to advance our understanding of cancer immunology.

Abstract

Cancer immunotherapy has revolutionized cancer treatment, spurring extensive investigation into cancer immunology and how to exploit this biology for therapeutic benefit. Current methods to investigate cancer-immune cell interactions and develop novel drug therapies rely on either two-dimensional (2D) culture systems or murine models. However, three-dimensional (3D) culture systems provide a potentially superior alternative model to both 2D and murine approaches. As opposed to 2D models, 3D models are more physiologically relevant and better replicate tumor complexities. Compared to murine models, 3D models are cheaper, faster, and can study the human immune system. In this review, we discuss the most common 3D culture systems—spheroids, organoids, and microfluidic chips—and detail how these systems have advanced our understanding of cancer immunology.