In vivo stepwise immunomodulation using chitosan nanoparticles as a platform nanotechnology for cancer immunotherapy

Biodegradable nanoplatforms for antigen delivery: part II - nanoparticles, hydrogels, and microneedles for cancer immunotherapy

INTRODUCTION

In recent years, chimeric antigen receptor T (CAR-T) cell therapy has resulted in a breakthrough in the treatment of patients with refractory or relapsed hematological malignancies. However, the identification of patients suitable for CAR-T cell therapy needs to be improved.

AREASCOVERED

CAR-T cell therapy has demonstrated excellent efficacy in hematological malignancies; however, views on determining when to apply CAR-T cells in terms of the evaluation of patient characteristics remain controversial.

EXPERT OPINION

We reviewed the current feasibility and challenges of CAR-T cell therapy in the most common hematological malignancies and classified them according to disease type and treatment priority, to guide clinicians and researchers in applying and investigating CAR-T cells further.

Nitroxide radical conjugated ovalbumin theranostic nanosystem for enhanced dendritic cell-based immunotherapy and T1 magnetic resonance imaging

Melanoma, known for its aggressive metastatic nature, presents a formidable challenge in cancer treatment, where conventional therapies often fall short. This study introduces a pioneering approach utilizing metal-free nanosystem as tumor vaccines, spotlighting their potential in revolutionizing melanoma treatment. This work employed organic nitroxides, specifically 4-carboxy-TEMPO, in combination with chitosan (CS), to create a novel nanocomposite material - the CS-TEMPO-OVA nanovaccines. This composition not only improves biocompatibility and extends blood circulation time of TEMPO but also marks a significant departure from traditional gadolinium-based contrast agents in MRI technology, addressing safety concerns. CS-TEMPO-OVA nanovaccines demonstrate excellent biocompatibility at both the cellular and organoid level. They effectively stimulate bone marrow-derived dendritic cells (BMDCs), which in turn promote the maturation and activation of T cells. This ultimately leads to a strong production of essential cytokines. These nanovaccines serve a dual purpose as both therapeutic and preventive. By inducing an immune response, activating cytotoxic T cells, and promoting macrophage M1 polarization, they effectively inhibit melanoma growth and enhance survival in mouse models. When combined with αPD-1, the CS-TEMPO-OVA nanovaccines significantly bolster the infiltration of cytotoxic T lymphocytes (CTLs) within tumors, sparking a powerful systemic antitumor response that effectively curbs tumor metastasis. The ability of these nanovaccines to control both primary (subcutaneous) and metastatic B16-OVA tumors highlights their remarkable efficacy. Furthermore, the CS-TEMPO-OVA nanovaccine can be administered in vivo via both intravenous and intramuscular routes, both of which effectively enhance the T1 contrast of magnetic resonance imaging in tumor tissue. This study offers invaluable insights into the integrated application of these nanovaccines in both clinical diagnostics and treatment, marking a significant stride in cancer research and patient care.

Immunogenicity of trivalent DNA vaccine candidate encapsulated in Chitosan-TPP nanoparticles against EV-A71 and CV-A16

Aim: To develop a trivalent DNA vaccine candidate encapsulated in Chitosan-TPP nanoparticles against hand foot and mouth disease (HFMD) and assess its immunogenicity in mice.Materials & methods: Trivalent plasmid carrying the VP1 and VP2 genes of EV-A71, VP1 gene of CV-A16 was encapsulated in Chitosan-TPP nanoparticles through ionic gelation. In vitro characterization and in vivo immunization studies of the CS-TPP-NPs (pIRES-VP121) were performed.Results: Mice administered with CS-TPP NPs (pIRES-VP121) intramuscularly were observed to have the highest IFN-γ response. Sera from mice immunized with the naked pDNA and CS-TPP-NPs (pIRES-VP121) demonstrated good viral clearance against wild-type EV-A71 and CV-A16 in RD cells.Conclusion: CS-TPP-NPs (pIRES-VP121) could serve as a prototype for future development of multivalent HFMD DNA vaccine candidates.

Therapeutic applications of carbohydrate-based compounds: a sweet solution for medical advancement

Carbohydrates, one of the most abundant biomolecules found in nature, have been seen traditionally as a dietary component of foods. Recent findings, however, have unveiled their medicinal potential in the form of carbohydrates-derived drugs. Their remarkable structural diversity, high optical purity, bioavailability, low toxicity and the presence of multiple functional groups have positioned them as a valuable scaffold and an exciting frontier in contemporary therapeutics. At present, more than 170 carbohydrates-based therapeutics have been granted approval by varying regulatory agencies such as United States Food and Drug Administration (FDA), Japan Pharmaceuticals and Medical Devices Agency (PMDA), Chinese National Medical Products Administration (NMPA), and the European Medicines Agency (EMA). This article explores an overview of the fascinating potential and impact of carbohydrate-derived compounds as pharmacological agents and drug delivery vehicles.

Drug delivery methods for cancer immunotherapy

Despite the fact that numerous immunotherapy-based drugs have been approved by the FDA for the treatment of primary and metastatic tumors, only a small proportion of the population can benefit from them because of primary and acquired resistances. Moreover, the translation of immunotherapy from the bench to the clinical practice is being challenging because of the short half-lives of the involved molecules, the difficulties to accomplish their delivery to the target sites, and some serious adverse effects that are being associated with these approaches. The emergence of drug delivery vehicles in the field of immunotherapy is helping to overcome these difficulties and limitations and this review describes how, providing some illustrative examples. Moreover, this article provides an exhaustive review of the studies that have been published to date on the particular case of hematological cancers. (Created with BioRender).

Research Progress of Chitosan-based Multifunctional Nanoparticles in Cancer Targeted Therapy

Conventional tumor therapeutic modalities, such as radiotherapy, chemotherapy, and surgery, involve low tumor inhibition efficiency, non-targeted drug delivery, and side effects. The development of novel and practical nano-drug delivery systems (DDSs) for targeted tumor therapy has become particularly important. Among various bioactive nanoparticles, chitosan is considered a suitable candidate for drug delivery due to its nontoxicity, good biocompatibility, and biodegradability. The amino and hydroxyl groups of chitosan endow it with the diverse function of chemical modification, thereby improving its physical and biological properties to meet the requirements of advanced biomedical applications. Therefore, it is necessary to review the property and applications of chitosan- based materials in biomedicine. In this review, the characteristics of chitosan related to its applications are first introduced, and then the preparation and modification of chitosan-based nanoparticles, including the function tailoring of chitosan-modified nanoparticles, are demonstrated and discussed. Finally, the opportunities and challenges of chitosan- based nanomaterials in this emerging field are proposed from the perspective of the rational and systematic design for the biomedicine field.

Four Ounces Can Move a Thousand Pounds: The Enormous Value of Nanomaterials in Tumor Immunotherapy

The application of nanomaterials in healthcare has emerged as a promising strategy due to their unique structural diversity, surface properties, and compositional diversity. In particular, nanomaterials have found a significant role in improving drug delivery and inhibiting the growth and metastasis of tumor cells. Moreover, recent studies have highlighted their potential in modulating the tumor microenvironment (TME) and enhancing the activity of immune cells to improve tumor therapy efficacy. Various types of nanomaterials are currently utilized as drug carriers, immunosuppressants, immune activators, immunoassay reagents, and more for tumor immunotherapy. Necessarily, nanomaterials used for tumor immunotherapy can be grouped into two categories: organic and inorganic nanomaterials. Though both have shown the ability to achieve the purpose of tumor immunotherapy, their composition and structural properties result in differences in their mechanisms and modes of action. Organic nanomaterials can be further divided into organic polymers, cell membranes, nanoemulsion-modified, and hydrogel forms. At the same time, inorganic nanomaterials can be broadly classified as nonmetallic and metallic nanomaterials. The current work aims to explore the mechanisms of action of these different types of nanomaterials and their prospects for promoting tumor immunotherapy.

Semisynthetic Pneumococcal Glycoconjugate Nanovaccine

Pneumococcal conjugate vaccines offer an excellent safety profile and high protection against the serotypes comprised in the vaccine. However, inclusion of protein antigens fromStreptococcus pneumoniaecombined with potent adjuvants and a suitable delivery system are expected to both extend protection to serotype strains not represented in the formulation and stimulate a broader immune response, thus more effective in young children, elderly, and immunocompromised populations. Along this line, nanoparticle (NP) delivery systems can enhance the immunogenicity of antigens by protecting them from degradation and increasing their uptake by antigen-presenting cells, as well as offering co-delivery with adjuvants. We report herein the encapsulation of a semisynthetic glycoconjugate (GC) composed of a synthetic tetrasaccharide mimicking theS. pneumoniae serotype 14 capsular polysaccharide (CP14) linked to the Pneumococcal surface protein A (PsaA) using chitosan NPs (CNPs). These GC-loaded chitosan nanoparticles (GC-CNPs) were not toxic to human monocyte-derived dendritic cells (MoDCs), showed enhanced uptake, and displayed better immunostimulatory properties in comparison to the naked GC. A comparative study was carried out in mice to evaluate the immune response elicited by the glycoconjugate-administered subcutaneously (SC), where the GC-CNPs displayed 100-fold higher IgG response as compared with the group treated with nonencapsulated GC. Overall, the study demonstrates the potential of this chitosan-based nanovaccine for efficient delivery of glycoconjugate antigens.

Nanocarriers for cancer nano-immunotherapy

The host immune system possesses an intrinsic ability to target and kill cancer cells in a specific and adaptable manner that can be further enhanced by cancer immunotherapy, which aims to train the immune system to boost the antitumor immune response. Several different categories of cancer immunotherapy have emerged as new standard cancer therapies in the clinic, including cancer vaccines, immune checkpoint inhibitors, adoptive T cell therapy, and oncolytic virus therapy. Despite the remarkable survival benefit for a subset of patients, the low response rate and immunotoxicity remain the major challenges for current cancer immunotherapy. Over the last few decades, nanomedicine has been intensively investigated with great enthusiasm, leading to marked advancements in nanoparticle platforms and nanoengineering technology. Advances in nanomedicine and immunotherapy have also led to the emergence of a nascent research field of nano-immunotherapy, which aims to realize the full therapeutic potential of immunotherapy with the aid of nanomedicine. In particular, nanocarriers present an exciting opportunity in immuno-oncology to boost the activity, increase specificity, decrease toxicity, and sustain the antitumor efficacy of immunological agents by potentiating immunostimulatory activity and favorably modulating pharmacological properties. This review discusses the potential of nanocarriers for cancer immunotherapy and introduces preclinical studies designed to improve clinical cancer immunotherapy modalities using nanocarrier-based engineering approaches. It also discusses the potential of nanocarriers to address the challenges currently faced by immuno-oncology as well as the challenges for their translation to clinical applications.

Tumor microenvironment penetrating chitosan nanoparticles for elimination of cancer relapse and minimal residual disease

Chitosan and its derivatives are among biomaterials with numerous medical applications, especially in cancer. Chitosan is amenable to forming innumerable shapes such as micelles, niosomes, hydrogels, nanoparticles, and scaffolds, among others. Chitosan derivatives can also bring unprecedented potential to cross numerous biological barriers. Combined with other biomaterials, hybrid and multitasking chitosan-based systems can be realized for many applications. These include controlled drug release, targeted drug delivery, post-surgery implants (immunovaccines), theranostics, biosensing of tumor-derived circulating materials, multimodal systems, and combination therapy platforms with the potential to eliminate bulk tumors as well as lingering tumor cells to treat minimal residual disease (MRD) and recurrent cancer. We first introduce different formats, derivatives, and properties of chitosan. Next, given the barriers to therapeutic efficacy in solid tumors, we review advanced formulations of chitosan modules as efficient drug delivery systems to overcome tumor heterogeneity, multi-drug resistance, MRD, and metastasis. Finally, we discuss chitosan NPs for clinical translation and treatment of recurrent cancer and their future perspective.

Nanoparticles targeting hematopoietic stem and progenitor cells: Multimodal carriers for the treatment of hematological diseases

Modern-day hematopoietic stem cell (HSC) therapies, such as gene therapy, modify autologous HSCs prior to re-infusion into myelo-conditioned patients and hold great promise for treatment of hematological disorders. While this approach has been successful in numerous clinical trials, it relies on transplantation of ex vivo modified patient HSCs, which presents several limitations. It is a costly and time-consuming procedure, which includes only few patients so far, and ex vivo culturing negatively impacts on the viability and stem cell-properties of HSCs. If viral vectors are used, this carries the additional risk of insertional mutagenesis. A therapy delivered to HSCs in vivo, with minimal disturbance of the HSC niche, could offer great opportunities for novel treatments that aim to reverse disease symptoms for hematopoietic disorders and could bring safe, effective and affordable genetic therapies to all parts of the world. However, substantial unmet needs exist with respect to the in vivo delivery of therapeutics to HSCs. In the last decade, in particular with the development of gene editing technologies such as CRISPR/Cas9, nanoparticles (NPs) have become an emerging platform to facilitate the manipulation of cells and organs. By employing surface modification strategies, different types of NPs can be designed to target specific tissues and cell types in vivo. HSCs are particularly difficult to target due to the lack of unique cell surface markers that can be utilized for cell-specific delivery of therapeutics, and their shielded localization in the bone marrow (BM). Recent advances in NP technology and genetic engineering have resulted in the development of advanced nanocarriers that can deliver therapeutics and imaging agents to hematopoietic stem- and progenitor cells (HSPCs) in the BM niche. In this review we provide a comprehensive overview of NP-based approaches targeting HSPCs to control and monitor HSPC activity in vitro and in vivo, and we discuss the potential of NPs for the treatment of malignant and non-malignant hematological disorders, with a specific focus on the delivery of gene editing tools.

Studies on chitosan-

PolyI:C is an immunomodulatory agent that can be used in immunotherapy, but its transportation in the body is hindered. In this study, a chitosan (CS)-graft-polyethyleneimine (PEI) copolymer (C-g-P) is prepared by an N,N′-carbonyl diimidazole (CDI) coupling method as a drug carrier for PolyI:C and simulated antigen ovalbumin (OVA). The results of FT-IR, 1H NMR, elemental analysis and cytotoxicity studies show that PEI is successfully grafted onto CS, and a low cytotoxicity of C-g-P-x (x = 1, 2, 3) with different PEI grafting rates are obtained. C-g-P-x-PolyI:C/OVA (C-g-P-x-PO) (x = 1, 2, 3) nanoparticles are prepared by combining C-g-P-x (x = 1, 2, 3), PolyI:C and OVA by electrostatic self-assembly. The results of agarose gel electrophoresis show that PolyI:C is well coated by the graft copolymer and protected from nuclease degradation. The results show that C-g-P-1-PO nanoparticles with graft copolymer to PolyI:C (N/P) ratios of 80:1 have the best solution stability, and the OVA encapsulation efficiency is 60.6%. The nanoparticles also have a suitable size and regular shape to be absorbed by cells. In vitro immunoassay results show that PolyI:C and OVA-loaded nanoparticles promote the secretion of tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ). CS-g-PEI is a reliable drug carrier for the delivery of PolyI:C and OVA, and it also provides the possibility to carry other drugs.

Therapeutic Cancer Vaccines—Antigen Discovery and Adjuvant Delivery Platforms

For decades, vaccines have played a significant role in protecting public and personal health against infectious diseases and proved their great potential in battling cancers as well. This review focused on the current progress of therapeutic subunit vaccines for cancer immunotherapy. Antigens and adjuvants are key components of vaccine formulations. We summarized several classes of tumor antigens and bioinformatic approaches of identification of tumor neoantigens. Pattern recognition receptor (PRR)-targeting adjuvants and their targeted delivery platforms have been extensively discussed. In addition, we emphasized the interplay between multiple adjuvants and their combined delivery for cancer immunotherapy.

Emerging role of RNA sensors in tumor microenvironment and immunotherapy

RNA sensors detect foreign and endogenous RNAs to protect the host by initiating innate and adaptive immune response. In tumor microenvironment (TME), activation of RNA sensors induces tumor-inhibitory cytotoxic T lymphocyte responses and inhibits the activity of immunosuppressive cells though stimulating type I IFN signaling pathway. These characteristics allow RNA sensors to be prospective targets in tumor immunotherapy. Therefore, a comprehensive understanding of the roles of RNA sensors in TME could provide new insight into the antitumor immunotherapy. Moreover, RNA sensors could be prominent triggering targets to synergize with immunotherapies. In this review, we highlight the diverse mechanisms of RNA sensors in cancer immunity and their emerging contributions in cancer immunotherapy, including monotherapy with RNA sensor agonists, as well as combination with chemotherapy, radiotherapy, immune checkpoint blockade or cancer vaccine.

Recent advances on chitosan as an adjuvant for vaccine delivery

Chitosan (CS) is a natural polymer derived from chitin that has wide applications in drugs, vaccines, and antigen delivery. The distinctive mucoadhesive, biocompatibility, biodegradable, and less toxic properties of chitosan compared to the currently used vaccine adjuvants made it a promising candidate for use as an adjuvant/carrier in vaccine delivery. In addition, chitosan exhibits intrinsic immunomodulating properties making it a suitable adjuvant in preparing vaccines delivery systems. Nanoparticles (NPs) of chitosan and its derivatives loaded with antigen have been shown to induce cellular and humoral responses. Versatility in the physicochemical properties of chitosan can provide an excellent opportunity to engineer antigen-specific adjuvant/delivery systems. This review discusses the recent advances of chitosan and its derivatives as adjuvants in vaccine deliveryand the published literature in the last fifteen years. The impact of physicochemical properties of chitosan on vaccine formulation has been described in detail. Applications of chitosan and its derivatives, their physicochemical properties, and mechanisms in enhancing immune responses have been discussed. Finally, challenges and future aspects of chitosan use has been pointed out.

NIR irradiation-controlled drug release utilizing injectable hydrogels containing gold-labeled liposomes for the treatment of melanoma cancer

Drug-based chemotherapy is associated with serious side effects. We developed a chemotherapeutic system comprising a chitosan hydrogel (CH-HG) containing gold cluster-labeled liposomal doxorubicin (DOX) (CH-HG-GL_DOX) as an injectable drug depot system. CH-HG-GL_DOX can be directly injected into tumor tissue without a surgical procedure, allowing this system to act as a reservoir for liposomal DOX. CH-HG-GL_DOX enhanced the retention time of DOX in tumor tissue and controlled its release in response to near-infrared (NIR) irradiation, resulting in significant inhibition of tumor growth and reduced DOX-related toxicity. The combined effect of CH-HG-GL_DOX and poly (D,L-lactide-co-glycolic acid) nanoparticle-based vaccines increased cytotoxic CD8+ T cell immunity, leading to enhanced synergistic therapeutic efficacy. CH-HG-GL_DOX provides an advanced therapeutic approach for local drug delivery and controlled release of DOX, resulting in reduced toxicity. Here, we suggest a combination strategy for chemo- and immunotherapies, as well as in nanomedicine applications. STATEMENT OF SIGNIFICANCE: We developed an injectable hydrogel containing gold cluster-labeled liposomes for sustained drug release at the tumor site. Moreover, we demonstrated the combined therapeutic efficacy of a hydrogel system and a nanoparticle-based immunotherapeutic vaccine for melanoma cancer. Thus, we show a potential combination approach for chemo- and immunotherapies for cancer treatment.

Nanomedicine for Immunotherapy Targeting Hematological Malignancies: Current Approaches and Perspective

Conventional chemotherapy has partial therapeutic effects against hematological malignancies and is correlated with serious side effects and great risk of relapse. Recently, immunotherapeutic drugs have provided encouraging results in the treatment of hematological malignancies. Several immunotherapeutic antibodies and cell therapeutics are in dynamic development such as immune checkpoint blockades and CAR-T treatment. However, numerous problems restrain the therapeutic effectiveness of tumor immunotherapy as an insufficient anti-tumor immune response, the interference of an immune-suppressive bone marrow, or tumoral milieu with the discharge of immunosuppressive components, access of myeloid-derived suppressor cells, monocyte intrusion, macrophage modifications, all factors facilitating the tumor to escape the anti-cancer immune response, finally reducing the efficiency of the immunotherapy. Nanotechnology can be employed to overcome each of these aspects, therefore having the possibility to successfully produce anti-cancer immune responses. Here, we review recent findings on the use of biomaterial-based nanoparticles in hematological malignancies immunotherapy. In the future, a deeper understanding of tumor immunology and of the implications of nanomedicine will allow nanoparticles to revolutionize tumor immunotherapy, and nanomedicine approaches will reveal their great potential for clinical translation.

Using Chitosan or Chitosan Derivatives in Cancer Therapy

Cancer is one of the major causes of death worldwide. Chemotherapeutic drugs have become a popular choice as anticancer agents. Despite the therapeutic benefits of chemotherapeutic drugs, patients often experience side effects and drug resistance. Biopolymers could be used to overcome some of the limitations of chemotherapeutic drugs, as well as be used either as anticancer agents or drug delivery vehicles. Chitosan is a biocompatible polymer derived from chitin. Chitosan, chitosan derivatives, or chitosan nanoparticles have shown their promise as an anticancer agent. Additionally, functionally modified chitosan can be used to deliver nucleic acids, chemotherapeutic drugs, and anticancer agents. More importantly, chitosan-based drug delivery systems improved the efficacy, potency, cytotoxicity, or biocompatibility of these anticancer agents. In this review, we will investigate the properties of chitosan and chemically tuned chitosan derivatives, and their application in cancer therapy.

Advances in Engineered Polymer Nanoparticle Tracking Platforms towards Cancer Immunotherapy-Current Status and Future Perspectives

Engineering polymeric nanoparticles for their shape, size, surface chemistry, and functionalization using various targeting molecules has shown improved biomedical applications for nanoparticles. Polymeric nanoparticles have created tremendous therapeutic platforms, particularly applications related to chemo- and immunotherapies in cancer. Recently advancements in immunotherapies have broadened this field in immunology and biomedical engineering, where "immunoengineering" creates solutions to target translational science. In this regard, the nanoengineering field has offered the various techniques necessary to manufacture and assemble multifunctional polymeric nanomaterial systems. These include nanoparticles functionalized using antibodies, small molecule ligands, targeted peptides, proteins, and other novel agents that trigger and encourage biological systems to accept the engineered materials as immune enhancers or as vaccines to elevate therapeutic functions. Strategies to engineer polymeric nanoparticles with therapeutic and targeting molecules can provide solutions for developing immune vaccines via maintaining the receptor storage in T- and B cells. Furthermore, cancer immunotherapy using polymeric nanomaterials can serve as a gold standard approach for treating primary and metastasized tumors. The current status of the limited availability of immuno-therapeutic drugs highlights the importance of polymeric nanomaterial platforms to improve the outcomes via delivering anticancer agents at localized sites, thereby enhancing the host immune response in cancer therapy. This review mainly focuses on the potential scientific enhancements and recent developments in cancer immunotherapies by explicitly discussing the role of polymeric nanocarriers as nano-vaccines. We also briefly discuss the role of multifunctional nanomaterials for their therapeutic impacts on translational clinical applications.

Using nanoparticles for in situ vaccination against cancer: mechanisms and immunotherapy benefits

Immunotherapy to treat cancer is now an established clinical approach. Immunotherapy can be applied systemically, as done with checkpoint blockade antibodies, but it can also be injected directly into identified tumors, in a strategy of in situ vaccination (ISV). ISV is designed to stimulate a strong local antitumor immune response involving both innate and adaptive immune cells, and through this generate a systemic antitumor immune response against metastatic tumors. A variety of ISVs have been utilized to generate an immunostimulatory tumor microenvironment (TME). These include attenuated microorganisms, recombinant proteins, small molecules, physical disruptors of TME (alternating magnetic and focused ultrasound heating, photothermal therapy, and radiotherapy), and more recently nanoparticles (NPs). NPs are attractive and unique since they can load multiple drugs or other reagents to influence immune and cancer cell functions in the TME, affording a unique opportunity to stimulate antitumor immunity. Here, we describe the NP-ISV therapeutic mechanisms, review chemically synthesized NPs (i.e., liposomes, polymeric, chitosan-based, inorganic NPs, etc.), biologically derived NPs (virus and bacteria-based NPs), and energy-activated NP-ISVs in the context of their use as local ISV. Data suggests that NP-ISVs can enhance outcomes of immunotherapeutic regimens including those utilizing tumor hyperthermia and checkpoint blockade therapies.

A Review on Cancer Immunotherapy and Applications of Nanotechnology to Chemoimmunotherapy of Different Cancers

Clinically, different approaches are adopted worldwide for the treatment of cancer, which still ranks second among all causes of death. Immunotherapy for cancer treatment has been the focus of attention in recent years, aiming for an eventual antitumoral effect through the immune system response to cancer cells both prophylactically and therapeutically. The application of nanoparticulate delivery systems for cancer immunotherapy, which is defined as the use of immune system features in cancer treatment, is currently the focus of research. Nanomedicines and nanoparticulate macromolecule delivery for cancer therapy is believed to facilitate selective cytotoxicity based on passive or active targeting to tumors resulting in improved therapeutic efficacy and reduced side effects. Today, with more than 55 different nanomedicines in the market, it is possible to provide more effective cancer diagnosis and treatment by using nanotechnology. Cancer immunotherapy uses the body's immune system to respond to cancer cells; however, this may lead to increased immune response and immunogenicity. Selectivity and targeting to cancer cells and tumors may lead the way to safer immunotherapy and nanotechnology-based delivery approaches that can help achieve the desired success in cancer treatment.

Immunomodulatory potential of chitosan-based materials for cancer therapy: a systematic review of in vitro, in vivo and clinical studies

Chitosan (Ch) has recently been used in different studies as a vaccine adjuvant with an ability to modulate the tumor microenvironment (TME). This systematic review aims to elucidate the added value of using Ch-based therapies for immunotherapeutic strategies in cancer treatment, through the exploration of different Ch-based formulations, their capacity to modulate immune cells in vitro and in vivo, and their translational potential for clinical settings. A systematic review was conducted on PubMed, following both inclusion and exclusion steps. Original articles which focused on the immunomodulatory role of Ch-based formulations in the TME were included, as well as its usage as a delivery vehicle for other immunomodulatory molecules. This review illustrates the added value of Ch-based systems to reshape the TME, through the modulation of immune cells using different Ch formulations, namely solutions, films, gels, microneedles and nanoparticles. Generally, Ch-based formulations increase the recruitment and proliferation of cells associated with pro-inflammatory abilities and decrease cells which exert anti-inflammatory activities. These effects correlated with a decreased tumor weight, reduced metastases, reversion of the immunosuppressive TME and increased survival in vivo. Overall, Ch-based formulations present the potential for immunotherapy in cancer. Nevertheless, clinical translation remains challenging, since the majority of the studies use Ch in formulations with other components, implicating that some of the observed effects could result from the combination of the individual effects. More studies on the use of different Ch-based formulations, complementary to standardization and disclosure of the Ch properties used are required to improve the immunomodulatory effects of Ch-based formulations in cancer.

Chitosan Nanomedicine in Cancer Therapy: Targeted Delivery and Cellular Uptake

Nanomedicine has gained much attention for the management and treatment of cancers due to the distinctive physicochemical properties of the drug-loaded particles. Chitosan's cationic nature is attractive for the development of such particles for drug delivery, transfection, and controlled release. The particle properties can be improved by modification of the polymer or the particle themselves. The physicochemical properties of chitosan particles are analyzed in 126 recent studies, which allows to highlight their impact on passive and active targeted drug delivery, cellular uptake, and tumor growth inhibition (TGI). From 2012 to 2019, out of 40 in vivo studies, only 4 studies are found reporting a reduction in tumor size by using chitosan particles while all other studies reported tumor growth inhibition relative to controls. A total of 23 studies are analyzed for cellular uptake including 12 studies reporting cellular uptake mechanisms. Understanding and exploiting the processes involved in targeted delivery, endocytosis, and exocytosis by controlling the physicochemical properties of chitosan particles are important for the development of safe and efficient nanomedicine. It is concluded based on the recent literature available on chitosan particles that combination therapies can play a pivotal role in transformation of chitosan nanomedicine from bench to bedside.

Arginine-Based Poly(I:C)-Loaded Nanocomplexes for the Polarization of Macrophages Toward M1-Antitumoral Effectors

Background: Tumor-associated macrophages (TAMs), with M2-like immunosuppressive profiles, are key players in the development and dissemination of tumors. Hence, the induction of M1 pro-inflammatory and anti-tumoral states is critical to fight against cancer cells. The activation of the endosomal toll-like receptor 3 by its agonist poly(I:C) has shown to efficiently drive this polarization process. Unfortunately, poly(I:C) presents significant systemic toxicity, and its clinical use is restricted to a local administration. Therefore, the objective of this work has been to facilitate the delivery of poly(I:C) to macrophages through the use of nanotechnology, that will ultimately drive their phenotype toward pro-inflammatory states.

Methods: Poly(I:C) was complexed to arginine-rich polypeptides, and then further enveloped with an anionic polymeric layer either by film hydration or incubation. Physicochemical characterization of the nanocomplexes was conducted by dynamic light scattering and transmission electron microscopy, and poly(I:C) association efficiency by gel electrophoresis. Primary human-derived macrophages were used as relevant in vitro cell model. Alamar Blue assay, ELISA, PCR and flow cytometry were used to determine macrophage viability, polarization, chemokine secretion and uptake of nanocomplexes. The cytotoxic activity of pre-treated macrophages against PANC-1 cancer cells was assessed by flow cytometry.

Results: The final poly(I:C) nanocomplexes presented sizes lower than 200 nm, with surface charges ranging from +40 to −20 mV, depending on the envelopment. They all presented high poly(I:C) loading values, from 12 to 50%, and great stability in cell culture media. In vitro, poly(I:C) nanocomplexes were highly taken up by macrophages, in comparison to the free molecule. Macrophage treatment with these nanocomplexes did not reduce their viability and efficiently stimulated the secretion of the T-cell recruiter chemokines CXCL10 and CCL5, of great importance for an effective anti-tumor immune response. Finally, poly(I:C) nanocomplexes significantly increased the ability of treated macrophages to directly kill cancer cells.

Conclusion: Overall, these enveloped poly(I:C) nanocomplexes might represent a therapeutic option to fight cancer through the induction of cytotoxic M1-polarized macrophages.

Nanotechnology-Based Vaccines for Allergen-Specific Immunotherapy: Potentials and Challenges of Conventional and Novel Adjuvants under Research

The increasing prevalence of allergic diseases demands efficient therapeutic strategies for their mitigation. Allergen-specific immunotherapy (AIT) is the only causal rather than symptomatic treatment method available for allergy. Currently, AIT is being administered using immune response modifiers or adjuvants. Adjuvants aid in the induction of a vigorous and long-lasting immune response, thereby improving the efficiency of AIT. The successful development of a novel adjuvant requires a thorough understanding of the conventional and novel adjuvants under development. Thus, this review discusses the potentials and challenges of these adjuvants and their mechanism of action. Vaccine development based on nanoparticles is a promising strategy for AIT, due to their inherent physicochemical properties, along with their ease of production and ability to stimulate innate immunity. Although nanoparticles have provided promising results as an adjuvant for AIT in in vivo studies, a deeper insight into the interaction of nanoparticle-allergen complexes with the immune system is necessary. This review focuses on the methods of harnessing the adjuvant effect of nanoparticles by detailing the molecular mechanisms underlying the immune response, which includes allergen uptake, processing, presentation, and induction of T cell differentiation.

Nucleic acid nanotechnology for cancer treatment

Cancer is one of the most prevalent potentially lethal diseases. With the increase in the number of investigations into the uses of nanotechnology, many nucleic acid (NA)-based nanostructures such as small interfering RNA, microRNA, aptamers, and immune adjuvant NA have been applied to treat cancer. Here, we discuss studies on the applications of NA in cancer treatment, recent research trends, and the limitations and prospects of specific NA-mediated gene therapy and immunotherapy for cancer treatment. The NA structures used for cancer therapy consist only of NA or hybrids comprising organic or inorganic substances integrated with functional NA. We also discuss delivery vehicles for therapeutic NA and anti-cancer agents, and recent trends in NA-based gene therapy and immunotherapy against cancer.

Chitosan and chitosan nanoparticles as adjuvant in local Rift Valley Fever inactivated vaccine

The present study aimed to improve the potency of inactivated Rift Valley Fever Virus (RVFV) vaccine using chitosan (CS) or chitosan nanoparticles (CNP) as adjuvants. Chitosan nanoparticles were prepared by ionic gelation method. Rift Valley Fever Virus (RVFV) inactivated antigen was loaded on CS and CNP to form two vaccine formulations, RVFV-chitosan nanoparticles based vaccine (RVFV-CNP) and RVFV chitosan based vaccine (RVFV-CS). Five groups of mice were used in this study, each group was injected with one of the following: phosphate buffer saline (group1 G1), RVFV-CNP (G2), (RVF-CS) (G3), RVFV-Alum based vaccine (RVFV-Alum) (G4) and adjuvant free RVFV inactivated antigen (RVFV-Ag) (G5). The immunization was performed twice with 2 weeks interval. The results showed that, RVFV-CNP vaccine enhanced strongly the phagocytic activity of peritoneal macrophage (PM), neutralization antibodies titer against RVFV and IgG values against RVFV nucleoprotein than other vaccine formulations did. In addition, the RVFV-CNP and RVF-CS vaccines upregulate the gene expression of IL-2, IFN-γ (which promote cell mediated immunity) and IL-4 (which promote humeral immunity), while RVFV-Alum vaccine upregulate the gene expression of IL-4 only. These findings indicated that CS and CNP were comparable to the alum as adjuvant in efficacy but superior to it in inducing cell-mediated immune response and might be a candidate adjuvant for inactivated RVFV vaccine.

Chitosan Nanoparticles: Shedding Light on Immunotoxicity and Hemocompatibility

Nanoparticles (NPs) assumed an important role in the area of drug delivery. Despite the number of studies including NPs are growing over the last years, their side effects on the immune system are often ignored or omitted. One of the most studied polymers in the nano based drug delivery system field is chitosan (Chit). In the scientific literature, although the physicochemical properties [molecular weight (MW) or deacetylation degree (DDA)] of the chitosan, endotoxin contamination and appropriate testing controls are rarely reported, they can strongly influence immunotoxicity results. The present work aimed to study the immunotoxicity of NPs produced with different DDA and MW Chit polymers and to benchmark it against the polymer itself. Chit NPs were prepared based on the ionic gelation of Chit with sodium tripolyphosphate (TPP). This method allowed the production of two different NPs: Chit 80% NPs (80% DDA) and Chit 93% NPs (93% DDA). In general, we found greater reduction in cell viability induced by Chit NPs than the respective Chit polymers when tested in vitro using human peripheral blood monocytes (PBMCs) or RAW 264.7 cell line. In addition, Chit 80% NPs were more cytotoxic for PBMCs, increased reactive oxygen species (ROS) production (above 156 μg/mL) in the RAW 264.7 cell line and interfered with the intrinsic pathway of coagulation (at 1 mg/mL) when compared to Chit 93% NPs. On the other hand, only Chit 93% NPs induced platelet aggregation (at 2 mg/mL). Although Chit NPs and Chit polymers did not stimulate the nitric oxide (NO) production in RAW 264.7 cells, they induced a decrease in lipopolysaccharide (LPS)-induced NO production at all tested concentrations. None of Chit NPs and polymers caused hemolysis, nor induced PBMCs to secrete TNF-α and IL-6 cytokines. From the obtained results we concluded that the DDA of the Chit polymer and the size of Chit NPs influence the in vitro immunotoxicity results. As the NPs are more cytotoxic than the corresponding polymers, one should be careful in the extrapolation of trends from the polymer to the NPs, and in the comparisons among delivery systems prepared with different DDA chitosans.

Oral Deliverable Mucoadhesive Chitosan-Salmonella Subunit Nanovaccine for Layer Chickens

PURPOSE

Salmonellosis in poultry is a serious economic burden. A major concern is the public health hazard caused by consumption of Salmonella-contaminated poultry products. Currently used Salmonella vaccines are ineffective in combating poultry Salmonellosis warranting the need of a potent vaccine, especially an oral vaccine that can elicit robust local intestinal immunity.

MATERIALS AND METHODS

A Salmonella subunit chitosan nanoparticles (NPs)-based vaccine was prepared that contained immunogenic outer membrane proteins (OMPs) and -flagellin (F) protein (OMPs-F-CS NPs). OMPs-F-CS NPs were administered as an oral vaccine in layer chickens and the resultant humoral and cell-mediated immune responses and localization of NPs were examined using standard detection methods.

RESULTS

We demonstrated targeting of surface F-protein coated chitosan NPs to immune cells when delivered orally to layer chickens, the particles were localized in ileal Peyer's patches. The OMPs-F-CS NPs vaccinated layer chickens had significantly higher OMPs-specific mucosal IgA production and lymphocyte proliferation response. The candidate vaccine increased the expression of toll-like receptor (TLR)-2, TLR-4, IFN-γ, TGF-ß and IL-4 mRNA expression in chicken cecal tonsils.

CONCLUSION

Our study demonstrated that the chitosan-based oral Salmonella nanovaccine targets immune cells of chickens and induced antigen-specific B and T cell responses. This candidate oral Salmonella nanovaccine has the potential to mitigate Salmonellosis in poultry.

Hazard Assessment of Polymeric Nanobiomaterials for Drug Delivery: What Can We Learn From Literature So Far

The physicochemical properties of nanobiomaterials, such as their small size and high surface area ratio, make them attractive, novel drug-carriers, with increased cellular interaction and increased permeation through several biological barriers. However, these same properties hinder any extrapolation of knowledge from the toxicity of their raw material. Though, as suggested by the Safe-by-Design (SbD) concept, the hazard assessment should be the starting point for the formulation development. This may enable us to select the most promising candidates of polymeric nanobiomaterials for safe drug-delivery in an early phase of innovation. Nowadays the majority of reports on polymeric nanomaterials are focused in optimizing the nanocarrier features, such as size, physical stability and drug loading efficacy, and in performing preliminary cytocompatibility testing and proving effectiveness of the drug loaded formulation, using the most diverse cell lines. Toxicological studies exploring the biological effects of the polymeric nanomaterials, particularly regarding immune system interaction are often disregarded. The objective of this review is to illustrate what is known about the biological effects of polymeric nanomaterials and to see if trends in toxicity and general links between physicochemical properties of nanobiomaterials and their effects may be derived. For that, data on chitosan, polylactic acid (PLA), polyhydroxyalkanoate (PHA), poly(lactic-co-glycolic acid) (PLGA) and policaprolactone (PCL) nanomaterials will be evaluated regarding acute and repeated dose toxicity, inflammation, oxidative stress, genotoxicity, toxicity on reproduction and hemocompatibility. We further intend to identify the analytical and biological tests described in the literature used to assess polymeric nanomaterials toxicity, to evaluate and interpret the available results and to expose the obstacles and challenges related to the nanomaterial testing. At the present time, considering all the information collected, the hazard assessment and thus also the SbD of polymeric nanomaterials is still dependent on a case-by-case evaluation. The identified obstacles prevent the identification of toxicity trends and the generation of an assertive toxicity database. In the future, in vitro and in vivo harmonized toxicity studies using unloaded polymeric nanomaterials, extensively characterized regarding their intrinsic and extrinsic properties should allow to generate such database. Such a database would enable us to apply the SbD approach more efficiently.

Enhanced anti-tumor immunotherapy by silica-coated magnetic nanoparticles conjugated with ovalbumin

Background

The effective induction of an antigen-specific T cell immune response through dendritic cell activation is one of the key goals of tumor immunotherapy.

Methods

In this study, efficient antigen-delivery carriers using silica-coated magnetic nanoparticles were designed and, their antigen-specific T cell immune response through dendritic cell activation investigated.

Results

The results showed that the silica-coated magnetic nanoparticles with conjugated ovalbumin enhanced the production of cytokines and antigen uptake in bone marrow-derived dendritic cells. Also, this induced an antigen-specific cytotoxic T lymphocyte (CTL) immune response and activated antigen-specific Th1 cell responses, including IL-2 and IFN-γ production and proliferation. We proved that the immune-stimulatory effects of silica-coated magnetic nanoparticles with conjugated ovalbumin were efficient in inhibiting of tumor growth in EG7-OVA (mouse lymphoma-expressing ovalbumin tumor-bearing mice model).

Conclusion

Therefore, the silica-coated magnetic nanoparticles with conjugated ovalbumin are expected to be useful as efficient anti-cancer immunotherapy agents.

Implantable microneedles with an immune-boosting function for effective intradermal influenza vaccination

This study details effective influenza vaccination via sustained intradermal (ID) release of vaccines using implantable and patch-free chitosan microneedles (MNs). The microneedle (MN) patch is composed of vaccine-loaded chitosan MNs with a dissolvable supporting array that gives extra length for complete insertion of MNs and is dissolved within the skin during insertion. Chitosan MNs can be quickly and entirely implanted into the dermis to function as a depot and an immune-boosting agent for the extended release of vaccines and simultaneous activation of the immune system. We found the influenza virus-specific antibody levels induced by chitosan MN vaccination were significantly higher than those elicited by intramuscular (IM) immunization with influenza vaccine alone. The MN induced immune-enhancing effect was obvious 4 week after the vaccination and lasted for at least 16 weeks. Most importantly, MN-immunized mice were completely protected from H1N1 viral challenge without major weight loss, whereas mice receiving IM injection at the same dose had a mortality rate of 60% and experienced notable weight loss after challenge. Our results suggest that the chitosan MNs cannot only be a viable tool for precise ID vaccine delivery but also exert strong adjuvanticity to enhance vaccine potency and induce protective immunity against influenza virus infections. STATEMENT OF SIGNIFICANCE: There is an urgent need for generating a new vaccination strategy to address the threat of global pandemic influenza. This study presents implantable chitosan microneedles (MNs) with immune-boosting function for effective influenza vaccination. We demonstrate that the chitosan MN can not only be an efficient tool for sustained intradermal delivery but also serve as an immunological adjuvant to boost vaccine efficacy. Continuous antigen exposure and immune stimulation provided by the implanted MNs may enhance the immunogenicity of influenza vaccines and evoke long-lasting immune responses to completely protect mice from lethal influenza challenge. The proposed MN system has great potential to be used as a new adjuvanted vaccine formulation and make influenza vaccination more effective and more accessible.

Drug Delivery for Cancer Immunotherapy and Vaccines

Cancer cells are able to avoid immune surveillance and exploit the immune system to grow and metastasize. With the development of nano- and micro-particles, there has been a growing number of immunotherapy delivery systems developed to elicit innate and adaptive immune responses to eradicate cancer cells. This can be accomplished by training resident immune cells to recognize and eliminate cells with tumor-associated antigens or by providing external stimuli to enhance tumor cell apoptosis in the immunosuppressive tumor microenvironment (TME). In this review we will focus on nano- and micro-particle (NP and MP) based immunotherapies and vaccines used to elicit a potent and sustained antitumor immune response.

Nucleic acids presenting polymer nanomaterials as vaccine adjuvants

Most vaccines developed today include only the antigens that best stimulate the immune system rather than the entire virus or microbe, which makes vaccine production and use safer and easier, though they lack potency to induce acceptable immunity and long-term protection. The incorporation of additional immune stimulating components, named adjuvants, is required to generate a strong protective immune response. Nucleic acids (DNA and RNA) and their synthetic analogs are promising candidates as vaccine adjuvants activating Toll-like receptors (TLRs). Additionally, in the last few years several nanocarriers have emerged as platforms for targeted co-delivery of antigens and adjuvants. In this review, we focus on the recent developments in polymer nanomaterials presenting nucleic acids as vaccine adjuvants. We aim to compare the effectiveness of the various classes of polymers in immune modulating materials (nanoparticles, dendrimers, single-chain particles, nanogels, polymersomes and DNA-based architectures). In particular, we address the critical role of parameters such as size, shape, complexation and release of TLR ligands, cellular uptake, stability, toxicity and potential importance of spatial control in ligand presentation.

Roles of the cGAS-STING Pathway in Cancer Immunosurveillance and Immunotherapy

Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that initiates innate immune responses. DNA-bound cGAS produces cyclic GMP-AMP (cGAMP), which activates stimulator of interferon genes (STING) to induce inflammatory cytokines and other immune mediators. cGAS detects DNA without sequence specificity and responds to both cytosolic foreign DNA from pathogens and self-DNA leaked into the cytosol due to genome instability or cellular damage. Because of the diverse sources of cytosolic DNA, the cGAS-STING pathway plays a critical role during infection, autoimmune diseases, and senescence. Moreover, cGAS detects tumor-derived DNA and stimulates endogenous antitumor immunity. Thus, the cGAS-STING pathway is a promising target for cancer immunotherapy. Here, we review the role of the cGAS-STING pathway in various diseases and highlight various approaches targeting the cGAS-STING pathway for cancer therapy.

Chitosan-Based Nanomaterials for Drug Delivery

This review discusses different forms of nanomaterials generated from chitosan and its derivatives for controlled drug delivery. Nanomaterials are drug carriers with multiple features, including target delivery triggered by environmental, pH, thermal responses, enhanced biocompatibility, and the ability to cross the blood-brain barrier. Chitosan (CS), a natural polysaccharide largely obtained from marine crustaceans, is a promising drug delivery vector for therapeutics and diagnostics, owing to its biocompatibility, biodegradability, low toxicity, and structural variability. This review describes various approaches to obtain novel CS derivatives, including their distinct advantages, as well as different forms of nanomaterials recently developed from CS. The advanced applications of CS-based nanomaterials are presented here in terms of their specific functions. Recent studies have proven that nanotechnology combined with CS and its derivatives could potentially circumvent obstacles in the transport of drugs thereby improving the drug efficacy. CS-based nanomaterials have been shown to be highly effective in targeted drug therapy.

Self-Assembled, Adjuvant/Antigen-Based Nanovaccine Mediates Anti-Tumor Immune Response against Melanoma Tumor

Malignant melanoma is a highly aggressive type of cancer that requires radical treatment strategies to inhibit the cancer cell progression and metastasis. In recent years, preclinical research and clinical trials on melanoma treatment have been considerably focused on the adjuvant-based immunotherapy for enhancing the immune response of innate immune cells against cancer cells. However, the clinical outcome of these adjuvant-based treatments is inadequate due to an improper delivery system for these immune activators to reach the target site. Hence, we developed a vaccine formulation containing tumor lysate protein (TL) and poly I:C (PIC) complexed with positively charged poly (sorbitol-co-polyethylenimine (PEI) (PSPEI). The resulting ionic PSPEI-polyplexed antigen/adjuvant (PAA) (PSPEI-PAA) nanocomplexes were stable at the physiological condition, are non-toxic, and have enhanced intracellular uptake of antigen and adjuvant in immature dendritic cells leading to dendritic cell maturation. In the murine B16F10 tumor xenograft model, PSPEI-PAA nanocomplexes significantly suppressed tumor growth and did not exhibit any noticeable sign of toxicity. The level of matured dendritic cells (CD80+/CD86+ cells) in the tumor draining lymph node of PSPEI-PAA treated tumor mice were enhanced and therefore CD8+ T cells infiltration in the tumor were enriched. Additionally, the cytotoxic T lymphocytes (CTLs) assay involving co-culturing of splenocytes isolated from the PSPEI-PAA-treated mice with that of B16F10 cells significantly revealed enhanced cancer killing by the TL-reactivated CTLs compared to untreated control mice bearing tumor. Therefore, we strongly believe that PSPEI-PAA nanocomplexes could be an efficient antigen/adjuvant delivery system and enhance the antitumor immune response against melanoma tumor in the future clinical trials.

CD44-Targeting PLGA Nanoparticles Incorporating Paclitaxel and FAK siRNA Overcome Chemoresistance in Epithelial Ovarian Cancer

Chemotherapy is commonly used in the treatment of ovarian cancer, yet most ovarian cancers harbor inherent resistance or develop acquired resistance. Therefore, novel therapeutic approaches to overcome chemoresistance are required. In this study, we developed a hyaluronic acid-labeled poly(d,l-lactide-co-glycolide) nanoparticle (HA-PLGA-NP) encapsulating both paclitaxel (PTX) and focal adhesion kinase (FAK) siRNA as a selective delivery system against chemoresistant ovarian cancer. The mean size and zeta potential of the HA-PLGA-NP were 220 nm and -7.3 mV, respectively. Incorporation efficiencies for PTX and FAK siRNA in the HA-PLGA-NPs were 77% and 85%, respectively. HA-PLGA-NP showed higher binding efficiency for CD44-positive tumor cells as compared with CD44-negative cells. HA-PLGA (PTX+FAK siRNA)-NP caused increased cytotoxicity and apoptosis in drug-resistant tumor cells. Treatment of human epithelial ovarian cancer tumor models HeyA8-MDR (P < 0.001) and SKOV3-TR (P < 0.001) with HA-PLGA (PTX+FAK siRNA)-NP resulted in significant inhibition of tumor growth. Moreover, in a drug-resistant, patient-derived xenograft (PDX) model, HA-PLGA (PTX+FAK siRNA)-NP significantly inhibited tumor growth compared with PTX alone (P < 0.002). Taken together, HA-PLGA-NP acts as an effective and selective delivery system for both the chemotherapeutic and the siRNA in order to overcome chemoresistance in ovarian carcinoma.Significance: These findings demonstrate the efficacy of a novel, selective, two-in-one delivery system to overcome chemoresistance in epithelial ovarian cancer. Cancer Res; 78(21); 6247-56. ©2018 AACR.

Efficiency of novel nanocombinations of bovine milk proteins (lactoperoxidase and lactoferrin) for combating different human cancer cell lines

Bovine lactoperoxidase (LPO) and lactoferrin (LF) are suitable proteins to be loaded or adsorbed to chitosan nanoparticles (NPs) for preparing stable nanoformulations with potent anticancer activity. In the present study, nanocombinations of LPO and LF revealed improvement in their stability and activity compared to single (free or nanoformulated) bovine proteins. The coating or loading of LPO-loaded NPs with LF resulted in the highest synergistic cytotoxicity effect against Caco-2, HepG-2, MCF-7 and PC-3 cells in comparison with other NPs and free proteins without causing toxicity toward normal cells. This synergistic improvement in the anticancer activity was apoptosis-dependent that was confirmed by severe alterations in cellular morphology, high percentage of annexin-stained cells and sub-G1 populations as well as nuclear staining with orange fluorescence of treated cancer cells. Additionally, significant alterations in the expression of well characterized cellular proliferation and apoptosis guards (NF-κB, Bcl-2 and p53) in these NPs-treated cancer cells compared to 5-fluorouracil (5-FU) treated cells. Our findings provide for the first time that these new synergistic nanoformulated forms of LPO and LF were superior in their selective apoptosis-mediating anticancer effect than free form of these proteins and 5-FU. LF coating or loading of LPO-loaded NPs present as promising therapy for cancer.

Poly(I:C)-Encapsulating Nanoparticles Enhance Innate Immune Responses to the Tuberculosis Vaccine Bacille Calmette-Guérin (BCG) via Synergistic Activation of Innate Immune Receptors

The attenuated live vaccine strain bacille Calmette-Guérin (BCG) is currently the only available vaccine against tuberculosis (TB), but is largely ineffective against adult pulmonary TB, the most common disease form. This is in part due to BCG's ability to interfere with the host innate immune response, a feature that might be targeted to enhance the potency of this vaccine. Here, we investigated the ability of chitosan-based nanoparticles (pIC-NPs) containing polyinosinic-polycytidylic acid (poly(I:C)), an inducer of innate immunity via Toll-like receptor 3 (TLR3), to enhance the immunogenicity of BCG in mouse bone marrow derived macrophages (BMDM) in vitro. Incorporation of poly(I:C) into NPs protected it against degradation by ribonucleases and increased its uptake by mouse BMDM. Whereas soluble poly(I:C) was ineffective, pIC-NPs strongly enhanced the proinflammatory immune response of BCG-infected macrophages in a synergistic fashion, as evident by increased production of cytokines and induction of nitric oxide synthesis. Using macrophages from mice deficient in key signaling molecules involved in the pathogen recognition response, we identified combined activation of MyD88- and TRIF-dependent TLR signaling pathways to be essential for the synergistic effect between BCG and NP. Moreover, synergy was strongly dependent on the order of the two stimuli, with TLR activation by BCG functioning as the priming event for the subsequent pIC-NP stimulus, which acted through an auto-/paracrine type I interferon (IFN) feedback loop. Our results provide a foundation for a promising new approach to enhance BCG-vaccine immunogenicity by costimulation with NPs. They also contribute to a molecular understanding of the observed synergistic interaction between the pIC-NPs and BCG vaccine.

In vitro and in vivo investigation of chitosan–polylysine polymeric nanoparticles for ovalbumin and CpG co-delivery

A simple and powerful vaccine delivery system was developed by electrostatic binding of chitosan-based polycation methoxy poly(ethylene glycol)–chitosan–poly(l-lysine) (mPEG–CS–PLL) with ovalbumin (OVA) and cytosine–phosphate–guanine (CpG).