Engineering nanoparticles to overcome barriers to immunotherapy

Nanoformulations: Reforming treatment for non-small cell lung cancer metastasis

Non-small cell lung cancer (NSCLC) is frequently diagnosed at an advanced stage, with 20 % of cases presenting as localized disease, 25 % with regional metastasis, and 55 % with distant metastasis, contributing significantly to increased morbidity and mortality rates. Current treatments, including chemotherapy, immunotherapy, radiotherapy and targeted therapy, have shown therapeutic efficacy but are limited by issues such as lack of specificity, cytotoxicity, and therapeutic resistance. Nanoparticles (NPs) offer promising solutions to these challenges by enhancing drug penetration and retention, improving biocompatibility and stability, and achieving greater precision in targeting cancer cells. This review provides insights into various types of NPs utilized in anti-metastatic drug delivery, emphasizing their ability to enhance the efficacy of existing chemotherapeutics for the prophylaxis of metastatic NSCLC. The usage of NPs as carriers of synthetic and natural compounds aimed at inhibiting cancer cell migration and invasion have also been reviewed. Special attention has been given to biomimetic nanomaterials including extracellular vesicles, exosomes and engineered NPs, that are capable of targeting molecular pathways such as EMT, p53 and PI3K/Akt to treat metastatic NSCLC. Additionally, emphasis has been given to clinical trials of these nanoformulations and their efficacy. Although therapeutic outcomes have demonstrated certain improvements, challenges related to toxicity persist, highlighting the need for further optimization of these formulations to enhance safety and efficacy. Finally, we discuss the current limitations and future perspectives for integrating NPs into clinical settings as novel therapeutic agents for lung cancer metastasis.

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

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

Effect of Acetonitrile on the Conformation of Bovine Serum Albumin

The use of organic solvents in drug delivery systems (DDSs) either to produce albumin nanoparticles or to manipulate the binding of target molecules to albumin, a promising nanocarrier material, presents challenges due to the conformational changes induced in the protein. In this study, we investigated the alterations in the conformation of bovine serum albumin (BSA) caused by acetonitrile (ACN) in aqueous solution by using a combination of spectroscopic analysis and molecular dynamics (MD) simulations. Ultraviolet (UV) absorption, fluorescence, and infrared (IR) absorption spectroscopy were used to analyze the BSA conformation in the solutions containing 0-60 vol % ACN. Additionally, MD simulations were conducted to elucidate the interactions between BSA and solvent components, focusing on the structural changes in the hydrophobic pocket with Trp residues of the albumin. Increasing the ACN concentration leads to significant changes in the BSA conformation, as evidenced by shifts in UV fluorescence wavelength, decreased intensity, and alterations in IR absorption bands. Furthermore, the formation of protein aggregates was observed at high ACN concentration (30 vol % ACN), shown by increased hydrodynamic diameter distribution. MD simulations further demonstrate that the presence of ACN molecules near the hydrophobic pocket with the Trp-213 residue increases the fluctuations in the positions of amino acids observed near the hydrophobic pocket with Trp-213. Moreover, the intrusion of water molecules into the hydrophobic pocket under 60% ACN conditions with highly decreased solvent polarity was correlated with the changes in the BSA secondary structure. These findings enhance our understanding of how solvent polarity affects the albumin conformation, which is crucial for optimizing albumin-based DDS applications.

Chitosan-based hydrogels in cancer therapy: Drug and gene delivery, stimuli-responsive carriers, phototherapy and immunotherapy

Nanotechnology has transformed the oncology sector by particularly targeting cancer cells and enhancing the efficacy of conventional therapies, not only improving efficacy of conventional therapeutics, but also reducing systemic toxicity. Environmentally friendly materials are the top choice for treating cancer. Chitosan, sourced from chitin, is widely used with its derivatives for the extensive synthesis or modification of nanostructures. Chitosan has been deployed to develop hydrogels, as 3D polymeric networks capable of water absorption with wide biomedical application. The chitosan hydrogels are biocompatible and biodegradable structures that can deliver drugs, genes or a combination of them in cancer therapy. Increased tumor ablation, reducing off-targeting feature and protection of genes against degradation are benefits of using chitosan hydrogels in cancer therapy. The efficacy of cancer immunotherapy can be improved by chitosan hydrogels to prevent emergence of immune evasion. In addition, chitosan hydrogels facilitate photothermal and photodynamic therapy for tumor suppression. Chitosan hydrogels can synergistically integrate chemotherapy, immunotherapy, and phototherapy in cancer treatment. Additionally, chitosan hydrogels that respond to stimuli, specifically thermo-sensitive hydrogels, have been developed for inhibiting tumors.

Challenges of enzyme therapy: Why two players are better than one

Enzyme-based therapy has garnered significant attention for its current applications in various diseases. Despite the notable advantages associated with the use of enzymes as therapeutic agents, that could have high selectivity, affinity, and specificity for the target, their application faces challenges linked to physico-chemical and pharmacological properties. These limitations can be addressed through the encapsulation of enzymes in nanoplatforms as a comprehensive solution to mitigate their degradation, loss of activity, off-target accumulation, and immunogenicity, thus enhancing bioavailability, therapeutic efficacy, and circulation time, thereby reducing the number of administrations, and ameliorating patient compliance. The exploration of novel nanomedicine-based enzyme therapeutics for the treatment of challenging diseases stands as a paramount goal in the contemporary scientific landscape, but even then it is often not enough. Combining an enzyme with another therapeutic (e.g., a small molecule, another enzyme or protein, a monoclonal antibody, or a nucleic acid) within a single nanocarrier provides innovative multidrug-integrated therapy and ensures that both the actives arrive at the target site and exert their therapeutic effect, leading to synergistic action and superior therapeutic efficacy. Moreover, this strategic approach could be extended to gene therapy, a field that nowadays has gained increasing attention, as enzymes acting at genomic level and nucleic acids may be combined for synergistic therapy. This multicomponent therapeutic approach opens opportunities for promising future developments. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Nanomaterial-Driven Precision Immunomodulation: A New Paradigm in Therapeutic Interventions

Immunotherapy is a rapidly advancing field of research in the treatment of conditions such as cancer and autoimmunity. Nanomaterials can be designed for immune system manipulation, with precise targeted delivery and improved immunomodulatory efficacy. Here, we elaborate on various strategies using nanomaterials, including liposomes, polymers, and inorganic NPs, and discuss their detailed design intricacies, mechanisms, and applications, including the current regulatory issues. This type of nanomaterial design for targeting specific immune cells or tissues and controlling release kinetics could push current technological frontiers and provide new and innovative solutions for immune-related disorders and diseases without off-target effects. These materials enable targeted interactions with immune cells, thereby enhancing the effectiveness of checkpoint inhibitors, cancer vaccines, and adoptive cell therapies. Moreover, they allow for fine-tuning of immune responses while minimizing side effects. At the intersection of nanotechnology and immunology, nanomaterial-based platforms have immense potential to revolutionize patient-centered immunotherapy and reshape disease management. By prioritizing safety, customization, and compliance with regulatory standards, these systems can make significant contributions to precision medicine, thereby significantly impacting the healthcare landscape.

Nanocarrier-based gene delivery for immune cell engineering

Clinical advances in genetically modified immune cell therapies, such as chimeric antigen receptor T cell therapies, have raised hope for cancer treatment. The majority of these biotechnologies are based on viral methods for ex vivo genetic modification of the immune cells, while the non-viral methods are still in the developmental phase. Nanocarriers have been emerging as materials of choice for gene delivery to immune cells. This is due to their versatile physicochemical properties such as large surface area and size that can be optimized to overcome several practical barriers to successful gene delivery. The in vivo nanocarrier-based gene delivery can revolutionize cell-based cancer immunotherapies by replacing the current expensive autologous cell manufacturing with an off-the-shelf biomaterial-based platform. The aim of this research is to review current advances and strategies to overcome the challenges in nanoparticle-based gene delivery and their impact on the efficiency, safety, and specificity of the process. The main focus is on polymeric and lipid-based nanocarriers, and their recent preclinical applications for cancer immunotherapy.

The Application of Nanovaccines in Autoimmune Diseases

Autoimmune diseases are diseases caused by the body's chronic immune responses to self-antigens and attacks on the host's own cells, tissues and organs. The dysfunction of innate immunity and adaptive immunity leads to the destruction of autoimmune tolerance, which is the most basic factor leading to pathogenesis. The optimal strategy for autoimmune diseases is to modify the host immune system to restore tolerance. The ideal effect of therapeutic autoimmune diseases is to eliminate the autoantigen-specific spontaneous immune response without interfering with the immune response against other antigens. Therapeutic nanovaccines that produce immune tolerance conform to this principle. Nanomaterials provide a platform for antigen loading and modification due to their unique physical and chemical properties. Nanovaccines based on nanomaterial technology can simultaneously enable antigens and adjuvants to be absorbed by immune cells and induce rapid and durable immunity. Nanovaccines have the advantages of being able to be designed and loaded and of better protecting antigens from premature degradation. Nanovaccines also have the ability to target specific tissues or cells through optimized design. We review the latest research progress of nanovaccines for autoimmune diseases and the design strategies of nanovaccines to promote the development of more effective nanovaccines for autoimmune diseases.

Use of Albumin for Drug Delivery as a Diagnostic and Therapeutic Tool

Drug delivery is an important topic that has attracted the attention of researchers in recent years. Albumin nanoparticles play a significant role in drug delivery as a carrier due to their unique characteristics. Albumin is non-toxic, biocompatible, and biodegradable. Its structure is such that it can interact with different drugs, which makes the treatment of the disease faster and also reduces the side effects of the drug. Albumin nanoparticles can be used in the diagnosis and treatment of many diseases, including cancer, diabetes, Alzheimer's, etc. These nanoparticles can connect to some compounds, such as metal nanoparticles, antibodies, folate, etc. and create a powerful nanostructure for drug delivery. In this paper, we aim to investigate albumin nanoparticles in carrier format for drug delivery application. In the beginning, different types of albumin and their preparation methods were discussed, and then albumin nanoparticles were discussed in detail in diagnosing and treating various diseases.

Novel Strategies Using Sagacious Targeting for Site-Specific Drug Delivery in Breast Cancer Treatment: Clinical Potential and Applications

For more than a decade, researchers have been working to achieve new strategies and smart targeting drug delivery techniques and technologies to treat breast cancer (BC). Nanotechnology presents a hopeful strategy for targeted drug delivery into the building of new therapeutics using the properties of nanomaterials. Nanoparticles are of high regard in the field of diagnosis and the treatment of cancer. The use of these nanoparticles as an encouraging approach in the treatment of various cancers has drawn the interest of researchers in recent years. In order to achieve the maximum therapeutic effectiveness in the treatment of BC, combination therapy has also been adopted, leading to minimal side effects and thus an enhancement in the quality of life for patients. This review article compares, discusses and criticizes the approaches to treat BC using novel design strategies and smart targeting of site-specific drug delivery systems.

A Glance on Nanovaccine: A Potential Approach for Disease Prevention

There are several vaccines available for preventing various bacterial and viral infections, but still, there are many challenges that require the development of noninvasive, more efficient, and active vaccines. The advancement in biotechnological tools has provided safer antigens, such as nucleic acids, proteins etc., but due to their lower immunogenic property, adjuvants of stronger immune response are required. Nanovaccines are effective vaccines when compared with conventional vaccines as they can induce both Humoral and cell-mediated immune responses and also provide longer immunogenic memory. The nanocarriers used in vaccines act as adjuvant. They provide site-specific delivery of antigens and can be used in conjugation with immunostimulatory molecules for enhancing adjuvant therapy. The nanovaccines avoid degrading cell pathways and provide effective absorption into blood vessels. The higher potential of nanovaccines to treat various diseases, such as acquired immuno deficiency syndrome, cancer, tuberculosis, malaria and many others, along with their immunological mechanisms and different types, have been discussed in the review.

Current Immunotherapy Strategies for Rheumatoid Arthritis: The Immunoengineering and Delivery Systems

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease accompanied by persistent multiarticular synovitis and cartilage degradation. The present clinical treatments are limited to disease-modifying anti-rheumatic drugs (DMARDs) and aims to relieve pain and control the inflammation of RA. Despite considerable advances in the research of RA, the employment of current clinical procedure is enormous, hindered by systemic side effect, frequent administration, tolerance from long-lasting administration, and high costs. Emerging immunoengineering-based strategies, such as multiple immune-active nanotechnologies via mechanism-based immunology approaches, have been developed to improve specific targeting and to reduce adverse reactions for RA treatments. Here, we review recent studies in immunoengineering for the treatment of RA. The prospect of future immunoengineering treatment for RA has also been discussed.

Immunomodulatory effects of nanoparticles on dendritic cells in a model of allergic contact dermatitis: importance of PD-L2 expression

Nanoparticle (NP) skin exposure is linked to an increased prevalence of allergic contact dermatitis. In our prior studies using the mouse contact hypersensitivity (CHS) model, we reported that silica 20 nm (SiO2) NPs suppressed the allergic response and titanium dioxide NPs doped with manganese (mTiO2) exacerbated it. In this work, we conducted in vitro experiments using bone marrow-derived dendritic cells (BMDCs) to study the combinatorial effect of the potent 2,4-dinitrofluorobenzene (DNFB) hapten sensitizer with SiO2 and mTiO2 NPs on BMDC cytotoxicity, cytokine secretion and phenotype using the B7 family ligands. Results show that DNFB and mTiO2 behave similarly and exhibit proinflammatory characteristics while SiO2 promotes a naive phenotype. We observe that the B7-H3 (CD276) ligand is only expressed on CD80 + (B7-1) BMDCs. Results from adoptive transfer CHS studies, combined with BMDC phenotype analysis, point to the importance of PD-L2 expression in modulating the adaptive immune response. This work identifies metrics that can be used to predict the effects of NPs on contact allergy and to guide efforts to engineer cell-based therapies to induce hapten specific immune tolerance.

Nano-immunotherapy: overcoming delivery challenge of immune checkpoint therapy

Immune checkpoint (ICP) molecules expressed on tumor cells can suppress immune responses against tumors. ICP therapy promotes anti-tumor immune responses by targeting inhibitory and stimulatory pathways of immune cells like T cells and dendritic cells (DC). The investigation into the combination therapies through novel immune checkpoint inhibitors (ICIs) has been limited due to immune-related adverse events (irAEs), low response rate, and lack of optimal strategy for combinatorial cancer immunotherapy (IMT). Nanoparticles (NPs) have emerged as powerful tools to promote multidisciplinary cooperation. The feasibility and efficacy of targeted delivery of ICIs using NPs overcome the primary barrier, improve therapeutic efficacy, and provide a rationale for more clinical investigations. Likewise, NPs can conjugate or encapsulate ICIs, including antibodies, RNAs, and small molecule inhibitors. Therefore, combining the drug delivery system (DDS) with ICP therapy could provide a profitable immunotherapeutic strategy for cancer treatment. This article reviews the significant NPs with controlled DDS using current data from clinical and pre-clinical trials on mono- and combination IMT to overcome ICP therapeutic limitations.

Immunomodulatory Effects of Nanoparticles on Dendritic Cells in a Model of Allergic Contact Dermatitis - Importance of PD-L2 Expression

Nanoparticle (NP) skin exposure is linked to the increased prevalence of allergic contact dermatitis. In prior studies using the mouse contact hypersensitivity (CHS) model, we reported that silica 20 nm (Si20nm) suppressed the allergic response and TiO2 doped with manganese (mTiO2) exacerbated it. In this work, we conducted in vitro experiments using bone marrow-derived dendritic cells (BMDCs) to study the combinatorial effect of the potent 2, 4-dinitrofluorobenzene (DNFB) hapten sensitizer with Si20nm and mTiO2 NPs on BMDC cytotoxicity, cytokine secretion and phenotype using the B7 family ligands. Results show that DNFB and mTiO2 behave similarly and exhibit proinflammatory characteristics while Si20nm promotes a naive phenotype. We observe that the B7-H3 (CD276) ligand is only expressed on CD80+ (B7-1) BMDC. Results from adoptive transfer CHS studies, combined with BMDC phenotype analysis, point to the importance of PD-L2 expression in modulating the adaptive immune response. This work identifies metrics that can be used to predict the effects of NPs on contact allergy and to guide efforts to engineer cell-based therapies to induce antigen specific immune tolerance.

Carrier-free subunit nanovaccine amplifies immune responses against tumors and viral infections

Codelivering subunit antigens and Toll-like receptor (TLR) molecular adjuvants via nanocarriers can stimulate potent innate and specific immune responses. Simple and effective nanovaccines fabrication is crucial for application. However, most nanovaccines were fabricated by introducing additional delivery materials, increasing safety risk, cost and processing complexity. Herein, a carrier-free nanovaccine was facilely prepared using a TLR1/TLR2 adjuvant, Diprovocim, rich in benzene rings that could interact with aromatic residues in subunit antigens through π-π stacking without additional materials. The carrier-free nanovaccines with a narrow size distribution could target lymph nodes (LNs) after intravenous injection to mice. The carrier-free nanovaccines based on ovalbumin (OVA) can stimulate strong antibody titers and CD4⁺ and CD8⁺ T cell immune responses in mice, and it synergized with anti-PD1 showing a potent tumor suppression in B16F10-OVA tumor model of mice. Furthermore, the carrier-free nanovaccine with glycoprotein E (gE), a glycoprotein of the varicella-zoster virus (VZV), also showed potent humoral and cellular immune responses. Therefore, using subunit proteins to support Diprovocim by π-π stacking provides a new approach for the preparation and application of novel vaccines for tumor therapy and prevention of infectious diseases. STATEMENT OF SIGNIFICANCE: Codelivering subunit antigens and adjuvants via nanocarriers stimulate potent innate and specific immune responses. However, existing delivery materials for fabricating nanovaccines will inevitably increase the cost of preparation, controllability, process complexity and safety assessment. Therefore, this study easily prepared carrier-free nanovaccines using the benzene ring-rich TLR1/TLR2 adjuvant Diprovocim, which can interact with aromatic residues in subunit antigens via π-π stacking without additional materials. The carrier-free nanovaccines of OVA demonstrated a potent tumor inhibition in treating melanoma in combination with anti-PD1. And the nanovaccines of gE stimulated a strong antibody titer and cellular immune response for herpes zoster. Thus, the present study provides a new approach for the preparation of subunit vaccines to combat various cancers and virus infections.

The novel treatments based on tissue engineering, cell therapy and nanotechnology for cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) is a global public health issue. Conventional treatments have substantial costs, side effects, and parasite resistance. Due to easy application and inexpensive cost, topical treatment is the optimal approach for CL. It could be used alone or with systemic treatments. Electrospun fibers as drug release systems in treating skin lesions have various advantages such as adjustable drug release rate, maintaining appropriate humidity and temperature, gas exchange, plasticity at the lesion site, similarity with the skin extracellular matrix (ECM) and drug delivery with high efficiency. Hydrogels are valuable scaffolds in the treatment of skin lesions. The important features of hydrogels include preserving unstable drugs from degradation, absorption of wound secretions, high biocompatibility, improving the re-epithelialization of the wound and preventing the formation of scars. One of the issues in local drug delivery systems for the skin is the low permeability of drugs in the skin. Polymeric scaffolds that are designed as microneedle patches can penetrate the skin and overcome this challenge. Also, drug delivery using nanocarriers increases the effectiveness of drugs in lower and more tolerable doses and reduces the toxicity of drugs. The application of cell therapy in the treatment of parasitic and infectious diseases has been widely investigated. The complexity of leishmaniasis treatment requires identifying new treatment options like cell therapy to overcome the disease. Topics investigated in this study include drug delivery systems based on tissue engineering scaffolds, nanotechnology and cell therapy-based studies to reduce the complications of CL.

Effect of nanoparticles on gouty arthritis: a systematic review and meta-analysis

OBJECTIVE

The purpose of this study was to explore the effects of nanoparticles on gouty arthritis, and to provide evidence for the preclinical application of nanoparticles in gouty arthritis and ideas for nanomedicine improvement for nanoparticle researchers.

METHODS

Five databases including the Cochrane Library, PubMed, Scopus, Web of Science, and Embase were searched for eligible studies until April 2022. The quality of the selected studies was assessed by SYRCLE's risk of bias (RoB) tool, and the random-effects model was used to calculate the overall effect sizes of weighted mean differences (WMD).

RESULTS

Ten studies met the inclusion criteria. Results showed that nanoparticles were effective in reducing uric acid levels (WMD: -4.91; 95% confidence interval (CI): - 5.41 to - 4.41; p < 0.001), but were not better than allopurinol (WMD: -0.20; 95% CI: - 0.42 to 0.02; p = 0.099). It was worth noting that the nanoparticles were safer than allopurinol. Subgroup analyses indicated that nanoparticle encapsulated substance, animal species, nanoparticle dosage, animal quantity, and animal gender were all sources of heterogeneity.

CONCLUSION

The nanoparticles are safe medications for gouty arthritis which can effectively reduce uric acid levels in rodents. Although the results are still uncertain, it is expected to have certain clinical application value. The nanoparticles may be the preclinical medications for gouty arthritis in the future.

Chemically engineering cells for precision medicine

Cell-based therapy holds great potential to address unmet medical needs and revolutionize the healthcare industry, as demonstrated by several therapeutics such as CAR-T cell therapy and stem cell transplantation that have achieved great success clinically. Nevertheless, natural cells are often restricted by their unsatisfactory in vivo trafficking and lack of therapeutic payloads. Chemical engineering offers a cost-effective, easy-to-implement engineering tool that allows for strengthening the inherent favorable features of cells and confers them new functionalities. Moreover, in accordance with the trend of precision medicine, leveraging chemical engineering tools to tailor cells to accommodate patients individual needs has become important for the development of cell-based treatment modalities. This review presents a comprehensive summary of the currently available chemically engineered tools, introduces their application in advanced diagnosis and precision therapy, and discusses the current challenges and future opportunities.

Focused ultrasound-mediated small-molecule delivery to potentiate immune checkpoint blockade in solid tumors

In the last decade, immune checkpoint blockade (ICB) has revolutionized the standard of treatment for solid tumors. Despite success in several immunogenic tumor types evidenced by improved survival, ICB remains largely unresponsive, especially in "cold tumors" with poor lymphocyte infiltration. In addition, side effects such as immune-related adverse events (irAEs) are also obstacles for the clinical translation of ICB. Recent studies have shown that focused ultrasound (FUS), a non-invasive technology proven to be effective and safe for tumor treatment in clinical settings, could boost the therapeutic effect of ICB while alleviating the potential side effects. Most importantly, the application of FUS to ultrasound-sensitive small particles, such as microbubbles (MBs) or nanoparticles (NPs), allows for precise delivery and release of genetic materials, catalysts and chemotherapeutic agents to tumor sites, thus enhancing the anti-tumor effects of ICB while minimizing toxicity. In this review, we provide an updated overview of the progress made in recent years concerning ICB therapy assisted by FUS-controlled small-molecule delivery systems. We highlight the value of different FUS-augmented small-molecules delivery systems to ICB and describe the synergetic effects and underlying mechanisms of these combination strategies. Furthermore, we discuss the limitations of the current strategies and the possible ways that FUS-mediated small-molecule delivery systems could boost novel personalized ICB treatments for solid tumors.

Ganglioside-Functionalized Nanoparticles for Chimeric Antigen Receptor T-Cell Activation at the Immunological Synapse

Chimeric Antigen Receptor (CAR) T cell therapy has proven to be an effective strategy against hematological malignancies but persistence and activity against solid tumors must be further improved. One emerging strategy for enhancing efficacy is based on directing CAR T cells to antigen presenting cells (APCs). Activation of CAR T cells at the immunological synapse (IS) formed between APC and T cell is thought to promote strong, persistent antigen-specific T cell-mediated immune responses but requires integration of CAR ligands into the APC/T-cell interface. Here, we demonstrate that CAR ligand functionalized, lipid-coated, biodegradable polymer nanoparticles (NPs) that contain the ganglioside GM3 (GM3-NPs) bind to CD169 (Siglec-1)-expressing APCs and localize to the cell contact site between APCs and CAR T cells upon initiation of cell conjugates. The CD169+ APC/CAR T-cell interface is characterized by a strong optical colocalization of GM3-NPs and CARs, enrichment of F-actin, and recruitment of ZAP-70, indicative of integration of GM3-NPs into a functional IS. Ligands associated with GM3-NPs localized to the APC/T-cell contact site remain accessible to CARs and result in robust T-cell activation. Overall, this work identifies GM3-NPs as a potential antigen delivery platform for active targeting of CD169 expressing APCs and enhancement of CAR T-cell activation at the NP-containing IS.

Three-dimensional (3D) scaffolds as powerful weapons for tumor immunotherapy

Though increasing understanding and remarkable clinical successes have been made, enormous challenges remain to be solved in the field of cancer immunotherapy. In this context, biomaterial-based immunomodulatory strategies are being developed to boost antitumor immunity. For the local immunotherapy, macroscale biomaterial scaffolds with 3D network structures show great superiority in the following aspects: facilitating the encapsulation, localized delivery, and controlled release of immunotherapeutic agents and even immunocytes for more efficient immunomodulation. The concentrating immunomodulation in situ could minimize systemic toxicities, but still exert abscopal effects to harness the power of overall anticancer immune response for eradicating malignancy. To promote such promising immunotherapies, the design requirements of macroscale 3D scaffolds should comprehensively consider their physicochemical and biological properties, such as porosity, stiffness, surface modification, cargo release kinetics, biocompatibility, biodegradability, and delivery modes. To date, increasing studies have focused on the relationships between these parameters and the biosystems which will guide/assist the 3D biomaterial scaffolds to achieve the desired immunotherapeutic outcomes. In this review, by highlighting some recent achievements, we summarized the latest advances in the development of various 3D scaffolds as niches for cancer immunotherapy. We also discussed opportunities, challenges, current trends, and future perspectives in 3D macroscale biomaterial scaffold-assisted local treatment strategies. More importantly, this review put more efforts to illustrate how the 3D biomaterial systems affect to modulate antitumor immune activities, where we discussed how significant the roles and behaviours of 3D macroscale scaffolds towards in situ cancer immunotherapy in order to direct the design of 3D immunotherapeutic.

Molecularly Targeted Photothermal Ablation of Epidermal Growth Factor Receptor-Expressing Cancer Cells with a Polypyrrole-Iron Oxide-Afatinib Nanocomposite

Simple Summary

In this manuscript, we describe the design and synthesis of a nanocomposite containing afatinib, polypyrrole, and iron oxide (PIA-NC) to molecularly target epidermal growth factor receptor (EGFR)-overexpressing cancer cells for photothermal conversion. In addition to physical and chemical characterization, we also showed that PIA-NC induces selective reactive oxygen species surge and apoptosis in response to sublethal near-infrared light only in EGFR-overexpressing cancer cells, not in EGFR-negative fibroblasts. The work demonstrates the feasibility of photothermal therapy with cellular precision.

Abstract

Near-infrared–photothermal therapy (NIR-PTT) is a potential modality for cancer treatment. Directing photothermal effects specifically to cancer cells may enhance the therapeutic index for the best treatment outcome. While epithelial growth factor receptor (EGFR) is commonly overexpressed/genetically altered in human malignancy, it remains unknown whether targeting EGFR with tyrosine kinase inhibitor (TKI)-conjugated nanoparticles may direct NIR-PTT to cancers with cellular precision. In the present study, we tested this possibility through the fabrication of a polypyrrole–iron oxide–afatinib nanocomposite (PIA-NC). In the PIA-NC, a biocompatible and photothermally conductive polymer (polypyrrole) was conjugated to a TKI (afatinib) that binds to overexpressed wild-type EGFR without overt cytotoxicity. A Fenton catalyst (iron oxide) was further encapsulated in the NC to drive the intracellular ROS surge upon heat activation. Diverse physical and chemical characterization experiments were conducted. Particle internalization, cytotoxicity, ROS production, and apoptosis in EGFR-positive and -negative cell lines were investigated in the presence and absence of NIR. We found that the PIA-NCs were stable with a size of 243 nm and a zeta potential of +35 mV. These PIA-NCs were readily internalized close to the cell membrane by all types of cells used in the study. The Fourier transform infrared spectra showed 3295 cm⁻¹ peaks; substantial O–H stretching was seen, with significant C=C stretching at 1637 cm⁻¹; and a modest appearance of C–O–H bending at 1444 cm⁻¹ confirmed the chemical conjugation of afatinib but not iron oxide to the NC. At a NIR-PTT energy level that has a minimal cytotoxic effect, PIA-NC significantly sensitizes EGFR-overexpressing A549 lung cancer cells to NIR-PTT-induced cytotoxicity at a rate of 70%, but in EGFR-negative 3T3 fibroblasts the rate was 30%. Within 1 min of NIR-PTT, a surge of intracellular ROS was found in PIA-NC-treated A549 cells. This was followed by early induction of cellular apoptosis for 54 ± 0.081% of A549 cells. The number of viable cells was less than a quarter of a percent. Viability levels of A549 cells that had been treated with NIR or PIA were only 50 ± 0.216% and 80 ± 0.216%, respectively. Only 10 ± 0.816% of NIH3T3 cells had undergone necrosis, meaning that 90 ± 0.124% were alive. Viability levels were 65 ± 0.081% and 81 ± 0.2%, respectively, when only NIR and PIA were used. PIA binding was effective against A549 cells but not against NIH3T3 cells. The outcome revealed that higher levels of NC + NIR exposure caused cancer cells to produce more ROS. In summary, our findings proved that a molecularly targeted NC provides an orchestrated platform for cancer cell-specific delivery of NIR-PTT. The geometric proximity design indicates a novel approach to minimizing the off-target biological effects of NIR-PTT. The potential of PIA-NC to be further developed into real-world application warrants further investigation.

Inorganic nanoparticle-based advanced cancer therapies: promising combination strategies

Inorganic nanoparticles for drug delivery in cancer treatment offer many potential advantages because they can maximize therapeutic effect through targeting ligands while minimizing off-target side-effects through drug adsorption and infiltration. Although inorganic nanoparticles were introduced as drug carriers, they have emerged as having the capacity for combined therapeutic capabilities, including anticancer effects through cytotoxicity, suppression of oncogenes and cancer cell signaling pathway inhibition. The most promising advanced strategies for cancer therapy are as synergistic platforms for RNA interference (siRNA, miRNA, shRNA) and as synergistic drug delivery agents for the inhibition of cancer cell signaling pathways. The present work summarizes relevant current work, the promise of which is suggested by a projected compound annual growth rate of ∼20% for drug delivery alone.

Immunostimulatory Polymers as Adjuvants, Immunotherapies, and Delivery Systems

Activating innate immunity in a controlled manner is necessary for the development of next-generation therapeutics. Adjuvants, or molecules that modulate the immune response, are critical components of vaccines and immunotherapies. While small molecules and biologics dominate the adjuvant market, emerging evidence supports the use of immunostimulatory polymers in therapeutics. Such polymers can stabilize and deliver cargo while stimulating the immune system by functioning as pattern recognition receptor (PRR) agonists. At the same time, in designing polymers that engage the immune system, it is important to consider any unintended initiation of an immune response that results in adverse immune-related events. Here, we highlight biologically derived and synthetic polymer scaffolds, as well as polymer–adjuvant systems and stimuli-responsive polymers loaded with adjuvants, that can invoke an immune response. We present synthetic considerations for the design of such immunostimulatory polymers, outline methods to target their delivery, and discuss their application in therapeutics. Finally, we conclude with our opinions on the design of next-generation immunostimulatory polymers, new applications of immunostimulatory polymers, and the development of improved preclinical immunocompatibility tests for new polymers.

Nanoparticles for Coronavirus Control

More than 2 years have passed since the SARS-CoV-2 outbreak began, and many challenges that existed at the beginning of this pandemic have been solved. Some countries have been able to overcome this global challenge by relying on vaccines against the virus, and vaccination has begun in many countries. Many of the proposed vaccines have nanoparticles as carriers, and there are different nano-based diagnostic approaches for rapid detection of the virus. In this review article, we briefly examine the biology of SARS-CoV-2, including the structure of the virus and what makes it pathogenic, as well as describe biotechnological methods of vaccine production, and types of the available and published nano-based ideas for overcoming the virus pandemic. Among these issues, various physical and chemical properties of nanoparticles are discussed to evaluate the optimal conditions for the production of the nano-mediated vaccines. At the end, challenges facing the international community and biotechnological answers for future viral attacks are reviewed.

The Landscape of Nanovectors for Modulation in Cancer Immunotherapy

Immunotherapy represents a promising strategy for the treatment of cancer, which functions via the reprogramming and activation of antitumor immunity. However, adverse events resulting from immunotherapy that are related to the low specificity of tumor cell-targeting represent a limitation of immunotherapy's efficacy. The potential of nanotechnologies is represented by the possibilities of immunotherapeutical agents being carried by nanoparticles with various material types, shapes, sizes, coated ligands, associated loading methods, hydrophilicities, elasticities, and biocompatibilities. In this review, the principal types of nanovectors (nanopharmaceutics and bioinspired nanoparticles) are summarized along with the shortcomings in nanoparticle delivery and the main factors that modulate efficacy (the EPR effect, protein coronas, and microbiota). The mechanisms by which nanovectors can target cancer cells, the tumor immune microenvironment (TIME), and the peripheral immune system are also presented. A possible mathematical model for the cellular communication mechanisms related to exosomes as nanocarriers is proposed.

Engineering Optimal Vaccination Strategies: Effects of Physical Properties of the Delivery System on Functions

With rapid developments in medical science and technology, vaccinations have become the key to solving public health problems. Various diseases can be prevented by vaccinations, which mimic a disease by...

Effect of the stiffness of one-layer protein-based microcapsules on dendritic cell uptake and endocytic mechanism

Microcapsules are one of the most promising microscale drug carriers due to their facile fabrication, excellent deformability, and high efficacy in drug storage and delivery. Understanding the effects of their physicochemical properties (size, shape, rigidity, charge, surface chemistry, etc.) on both in vitro and in vivo performance is not only highly significant and interesting but also very challenging. Stiffness, an important design parameter, has been extensively explored in recent years, but how the rigidity of particles influences cellular internalization and uptake mechanisms remains controversial. Here, one-layered lysozyme-based microcapsules with well-controlled stiffness (modulus ranging from 3.49 ± 0.18 MPa to 26.14 ± 1.09 MPa) were prepared and used to investigate the effect of stiffness on the uptake process in dendritic cells and the underlying mechanism. The cellular uptake process and endocytic mechanism were investigated with laser scanning confocal microscopy, mechanism inhibitors, and pathway-specific antibody staining. Our data demonstrated that the stiffness of protein-based microcapsules could be a strong regulator of intracellular uptake and endocytic kinetics but had no obvious effect on the endocytic mechanism. We believe our results will provide a basic understanding of the intracellular uptake process of microcapsules and the endocytic mechanism and inspire strategies for the further design of potential drug delivery microcarriers.

A camptothecin-based, albumin-binding prodrug enhances efficacy and safety in vivo

The albumin-based drug delivery system is an effective drug delivery strategy for traditional chemotherapeutic drugs that can improve their antitumour efficacies and reduce systemic toxicities. The camptothecin derivative CPTS0001 has excellent antitumour activity in vitro, but it shows toxicity and side effects in vivo. In this study, we report the synthesis and biological evaluation of the β-glucuronidase-reactive albumin-binding prodrug Mal-glu-CPTS0001 based on quaternary ammonium. After intravenous administration, the compound covalently binds to plasma albumin through Michael addition, enabling it to accumulate in tumours, where tumour-associated β-glucuronidase triggers the selective release of CPTS0001. This prodrug significantly reduced the toxicity of the parent drug, and the maximum tolerated dose was increased by 2.5 times. At the same time, this prodrug enhanced the selectivity in vivo and improved the preferential accumulation of prodrug in tumours. Notably, this prodrug exhibited excellent in vivo antitumour effects in a murine breast cancer xenograft model without visible pathological toxicity.

Role of proteins in the biosynthesis and functioning of metallic nanoparticles

Proteins are known to play important roles in the biosynthesis of metallic nanoparticles (NPs), which are biological substitutes for conventionally used chemical capping and stabilizing agents. When a pristine nanoparticle comes in contact with a biological media or system, a bimolecular layer is formed on the surface of the nanoparticle and is primarily composed of proteins. The role of proteins in the biosynthesis and further uptake, translocation, and bio-recognition of nanoparticles is documented in the literature. But, a complete understanding has not been achieved concerning the mechanism for protein-mediated nanoparticle biosynthesis and the role proteins play in the interaction and recognition of nanoparticles, aiding its uptake and assimilation into the biological system. This review critically evaluates the knowledge and gaps in the protein-mediated biosynthesis of nanoparticles. In particular, we review the role of proteins in multiple facets of metallic nanoparticle biosynthesis, the interaction of proteins with metallic nanoparticles for recognition and interaction with cells, and the toxic potential of protein-nanoparticle complexes when presented to the cell.

The application of immune checkpoint blockade in breast cancer and the emerging role of nanoparticle

Breast cancer is the most common malignancy in the female population with a high mortality rate. Despite the satisfying depth of studies evaluating the contributory role of immune checkpoints in this malignancy, few articles have reviewed the pros and cons of immune checkpoint blockades (ICBs). In the current review, we provide an overview of immune-related inhibitory molecules and also discuss the original data obtained from international research laboratories on the aberrant expression of T and non-T cell-associated immune checkpoints in breast cancer. Then, we especially focus on recent studies that utilized ICBs as the treatment strategy in breast cancer and provide their efficiency reports. As there are always costs and benefits, we discuss the limitations and challenges toward ICB therapy such as adverse events and drug resistance. In the last section, we allocate an overview of the recent data concerning the application of nanoparticle systems for cancer immunotherapy and propose that nano-based ICB approaches may overcome the challenges related to ICB therapy in breast cancer. In conclusion, it seems it is time for nanoscience to more rapidly move forward into clinical trials and illuminates the breast cancer treatment area with its potent features for the target delivery of ICBs.

Development of a Polysaccharide-Based Hydrogel Drug Delivery System (DDS): An Update

Delivering a drug to the target site with minimal-to-no off-target cytotoxicity is the major determinant for the success of disease therapy. While the therapeutic efficacy and cytotoxicity of the drug play the main roles, the use of a suitable drug delivery system (DDS) is important to protect the drug along the administration route and release it at the desired target site. Polysaccharides have been extensively studied as a biomaterial for DDS development due to their high biocompatibility. More usefully, polysaccharides can be crosslinked with various molecules such as micro/nanoparticles and hydrogels to form a modified DDS. According to IUPAC, hydrogel is defined as the structure and processing of sols, gels, networks and inorganic–organic hybrids. This 3D network which often consists of a hydrophilic polymer can drastically improve the physical and chemical properties of DDS to increase the biodegradability and bioavailability of the carrier drugs. The advancement of nanotechnology also allows the construction of hydrogel DDS with enhanced functionalities such as stimuli-responsiveness, target specificity, sustained drug release, and therapeutic efficacy. This review provides a current update on the use of hydrogel DDS derived from polysaccharide-based materials in delivering various therapeutic molecules and drugs. We also highlighted the factors that affect the efficacy of these DDS and the current challenges of developing them for clinical use.

Targeting immunosuppressor cells with nanoparticles in autoimmunity: How far have we come to?

Autoimmunity is the assault of immune response towards self-antigens, resulting to inflammation and tissue injury. It is staged into three phases and caused by malfunction of immune tolerance. In our body, immune tolerance is synchronized by several immunosuppressor cells such as regulatory T cells and B cells as well as myeloid-derived suppressor cells, which are prominently dysregulated in autoimmunity. Hence, targeting these cell populations serve as a significant potential in the therapy of autoimmunity. Nanotechnology with its advantageous properties is shown to be a remarkable tool as drug delivery system in this field. This review focused on the development of therapeutics in autoimmune diseases utilizing various nanoparticles formulation based on two targeting approaches in autoimmunity, passive and active targeting. Lastly, this review outlined the approved present nanomedicines as well as in clinical evaluations and issues regarding the lack of translation of these nanomedicines into the market, despite the abundant of positive experimental observations.

Afatinib-loaded inhalable PLGA nanoparticles for localized therapy of non-small cell lung cancer (NSCLC)-development and in-vitro efficacy

Afatinib (AFA) is a potent aniline-quinazoline derivative, approved by the Food and Drug Administration (FDA) in 2013, as a first-line treatment for metastatic non-small cell lung cancer (NSCLC). However, its clinical application is highly limited by its poor solubility, and consequently low bioavailability. We hypothesize that loading of AFA into biodegradable PLGA nanoparticles for localized inhalational drug delivery will be instrumental in improving therapeutic outcomes in NSCLC patients. Formulated AFA nanoparticles (AFA-NP) were evaluated for physicochemical properties (particle size: 180.2 ± 15.6 nm, zeta potential: - 23.1 ± 0.2 mV, % entrapment efficiency: 34.4 ± 2.3%), formulation stability, in-vitro aerosol deposition behavior, and anticancer efficacy. Stability studies revealed the physicochemical stability of AFA-NP. Moreover, AFA-NP exhibited excellent inhalable properties (mass median aerodynamic diameter (MMAD): 4.7 ± 0.1 μm; fine particle fraction (FPF): 77.8 ± 4.3%), indicating efficient particle deposition in deep lung regions. With respect to in-vitro drug release, AFA-NP showed sustained drug release with cumulative release of 56.8 ± 6.4% after 48 h. Cytotoxic studies revealed that encapsulation of AFA into PLGA nanoparticles significantly enhanced its cytotoxic potential in KRAS-mutated NSCLC cell lines (A549, H460). Cellular uptake studies revealed enhanced internalization of coumarin-loaded nanoparticles compared to plain coumarin in A549. In addition, 3D tumor spheroid studies demonstrated superior efficacy of AFA-NP in tumor penetration and growth inhibition. To conclude, we have established in-vitro efficacy of afatinib-loaded PLGA nanoparticles as inhalable NSCLC therapy, which will be of great significance when designing preclinical and clinical studies. Graphical abstract.

Physiological and Pathological Factors Affecting Drug Delivery to the Brain by Nanoparticles

The prevalence of neurological/neurodegenerative diseases, such as Alzheimer's disease is known to be increasing due to an aging population and is anticipated to further grow in the decades ahead. The treatment of brain diseases is challenging partly due to the inaccessibility of therapeutic agents to the brain. An increasingly important observation is that the physiology of the brain alters during many brain diseases, and aging adds even more to the complexity of the disease. There is a notion that the permeability of the blood-brain barrier (BBB) increases with aging or disease, however, the body has a defense mechanism that still retains the separation of the brain from harmful chemicals in the blood. This makes drug delivery to the diseased brain, even more challenging and complex task. Here, the physiological changes to the diseased brain and aged brain are covered in the context of drug delivery to the brain using nanoparticles. Also, recent and novel approaches are discussed for the delivery of therapeutic agents to the diseased brain using nanoparticle based or magnetic resonance imaging guided systems. Furthermore, the complement activation, toxicity, and immunogenicity of brain targeting nanoparticles as well as novel in vitro BBB models are discussed.

Research progress in tumor targeted immunotherapy

INTRODUCTION

Compared with traditional cancer treatment methods, tumor-targeted immunotherapy can combine targeted therapy and immunotherapy with long-lasting responses to achieve synergistic therapy, which brings hope to the complete cure of cancer.

AREAS COVERED

This review summarizes the newest and most up-to-date advances in tumor-targeted immunotherapy, including tumor-associated macrophages (TAMs) targeted immunotherapy, regulatory T (Treg) cells targeted immunotherapy, tumor-associated fibroblasts (TAFs) targeted immunotherapy and immune checkpoints targeted immunotherapy.

EXPERT OPINION

Immunotherapy can restore anti-tumor immunity in the tumor microenvironment and produce a lasting immune surveillance effect. Smart multifunctional nano delivery system can effectively combine targeted therapy with immunotherapy, which has attracted extensive attention. With the deepening of research, more and more tumor-targeted immunotherapy enter into the clinical trial phases, especially antibodies and inhibitors. Tumor-targeted immunotherapy is a promising approach for conquering cancer and bringing hope for human health.

The Uniqueness of Albumin as a Carrier in Nanodrug Delivery

Albumin is an appealing carrier in nanomedicine because of its unique features. First, it is the most abundant protein in plasma, endowing high biocompatibility, biodegradability, nonimmunogenicity, and safety for its clinical application. Second, albumin chemical structure and conformation allows interaction with many different drugs, potentially protecting them from elimination and metabolism in vivo, thus improving their pharmacokinetic properties. Finally, albumin can interact with receptors overexpressed in many diseased tissues and cells, providing a unique feature for active targeting of the disease site without the addition of specific ligands to the nanocarrier. For this reason, albumin, characterized by an extended serum half-life of around 19 days, has the potential of promoting half-life extension and targeted delivery of drugs. Therefore, this article focuses on the importance of albumin as a nanodrug delivery carrier for hydrophobic drugs, taking advantage of the passive as well as active targeting potential of this nanocarrier. Particular attention is paid to the breakthrough NAB-Technology, with emphasis on the advantages of Nab-Paclitaxel (Abraxane), compared to the solvent-based formulations of Paclitaxel, i.e., CrEL-paclitaxel (Taxol) in a clinical setting. Finally, the role of albumin in carrying anticancer compounds is depicted, with a particular focus on the albumin-based formulations that are currently undergoing clinical trials. The article sheds light on the power of an endogenous substance, such as albumin, as a drug delivery system, signifies the importance of the drug vehicle in drug performance in the biological systems, and highlights the possible future trends in the use of this drug delivery system.

Challenges and Perspectives of Standard Therapy and Drug Development in High-Grade Gliomas

Despite their low incidence rate globally, high-grade gliomas (HGG) remain a fatal primary brain tumor. The recommended therapy often is incapable of resecting the tumor entirely and exclusively targeting the tumor leads to tumor recurrence and dismal prognosis. Additionally, many HGG patients are not well suited for standard therapy and instead, subjected to a palliative approach. HGG tumors are highly infiltrative and the complex tumor microenvironment as well as high tumor heterogeneity often poses the main challenges towards the standard treatment. Therefore, a one-fit-approach may not be suitable for HGG management. Thus, a multimodal approach of standard therapy with immunotherapy, nanomedicine, repurposing of older drugs, use of phytochemicals, and precision medicine may be more advantageous than a single treatment model. This multimodal approach considers the environmental and genetic factors which could affect the patient's response to therapy, thus improving their outcome. This review discusses the current views and advances in potential HGG therapeutic approaches and, aims to bridge the existing knowledge gap that will assist in overcoming challenges in HGG.

Nanobiotechnology for Agriculture: Smart Technology for Combating Nutrient Deficiencies with Nanotoxicity Challenges

Nanobiotechnology in agriculture is a driver for modern-day smart, efficient agricultural practices. Nanoparticles have been shown to stimulate plant growth and disease resistance. The goal of sustainable farming can be accomplished by developing and sustainably exploiting the fruits of nanobiotechnology to balance the advantages nanotechnology provides in tackling environmental challenges. This review aims to advance our understanding of nanobiotechnology in relevant areas, encourage interactions within the research community for broader application, and benefit society through innovation to realize sustainable agricultural practices. This review critically evaluates what is and is not known in the domain of nano-enabled agriculture. It provides a holistic view of the role of nanobiotechnology in multiple facets of agriculture, from the synthesis of nanoparticles to controlled and targeted delivery, uptake, translocation, recognition, interaction with plant cells, and the toxicity potential of nanoparticle complexes when presented to plant cells.

Enhancing Immunity with Nanomedicine: Employing Nanoparticles to Harness the Immune System

The failure of immune responses to vaccines and dysfunctional immune responses to viral infection, tumor development, or neoantigens lead to chronic viral infection, tumor progression, or incomplete immune protection after vaccination. Thus, strategies to boost host immunity are a topic of intense research and development. Engineered nanoparticles (NPs) possess immunological properties and can be modified to promote improved local immune responses. Nanoparticle-based approaches have been employed to enhance vaccine efficacy and host immune responses to viral and tumor antigens, with impressive results. In this Perspective, we present an overview of studies, such as the one reported by Alam et al. in this issue of ACS Nano, in which virus-like particles have been employed to enhance immunity. We review the cellular cornerstones of effective immunity and discuss how NPs can harness these interactions to overcome the current obstacles in vaccinology and oncology. We also discuss the barriers to effective NP-mediated immune priming including (1) NP delivery to the site of interest, (2) the quality of response elicited, and (3) the potential of the response to overcome immune escape. Through this Perspective, we aim to highlight the value of nanomedicine not only in delivering therapies but also in coordinating the enhancement of host immune responses. We provide a forward-looking outlook for future NP-based approaches and how they could be tailored to promote this outcome.

Advances in Bio-Based Polymers for Colorectal CancerTreatment: Hydrogels and Nanoplatforms

Adenocarcinoma of the colon is the most common malignant neoplasia of the gastrointestinal tract and is a major contributor to mortality worldwide. Invasiveness and metastatic behavior are typical of malignant tumors and, because of its portal drainage, the liver is the closest capillary bed available in this case, hence the common site of metastatic dissemination. Current therapies forecast total resection of primary tumor when possible and partial liver resection at advanced stages, along with systemic intravenous therapies consisting of chemotherapeutic agents such as 5-fluorouracil. These cures are definitely not exempt from drawbacks and heavy side effects. Biocompatible polymeric networks, both in colloids and bulk forms, able to absorb large quantities of water and load a variety of molecules-belong to the class of innovative drug delivery systems, thus suitable for the purpose and tunable on each patient can represent a promising alternative. Indeed, the implantation of polymeric scaffolds easy to synthesize can substitute chemotherapy and combination therapies scheduling, shortening side effects. Moreover, they do not require a surgical removal thanks to spontaneous degradation and guarantees an extended and regional cargo release, maintaining high drug concentrations. In this review, we focus our attention on the key role of polymeric networks as drug delivery systems potentially able to counteract this dramatic disease.