Polymer Nanoparticle-Mediated Delivery of Oxidized Tumor Lysate-Based Cancer Vaccines

Immunoactivity of a hybrid membrane biosurface on nanoparticles: enhancing interactions with dendritic cells to augment anti-tumor immune responses

Nano-biointerfaces play a pivotal role in determining the functionality of engineered therapeutic nanoparticles, particularly in the context of designing nanovaccines to effectively activate immune cells for cancer immunotherapy. Unlike involving chemical reactions by conventional surface decorating strategies, cell membrane-coating technology offers a straightforward approach to endow nanoparticles with natural biosurfaces, enabling them to mimic and integrate into the intricate biosystems of the body to interact with specific cells under physiological conditions. In this study, cell membranes, in a hybrid formulation, derived from cancer and activated macrophage cells were found to enhance the interaction of nanoparticles (HMP) with dendritic cells (DCs) and T cells among the mixed immune cells from lymph nodes (LNs), which could be leveraged in the development of nanovaccines for anti-tumor therapy. After loading with an adjuvant (R837), the nanoparticles coated with a hybrid membrane (HMPR) demonstrated effectiveness in priming DCs both in vitro and in vivo, resulting in amplified anti-tumor immune responses compared to those of nanoparticles coated with a single type of membrane or those lacking a membrane coating. The elevated immunoactivity of nanoparticles achieved by incorporating a hybrid membrane biosurface provides us a more profound comprehension of the nano-immune interaction, which may significantly benefit the development of bioactive nanomaterials for advanced therapy.

Nanovaccines: An effective therapeutic approach for cancer therapy

Cancer vaccines hold considerable promise for the immunotherapy of solid tumors. Nanomedicine offers several strategies for enhancing vaccine effectiveness. In particular, molecular or (sub) cellular vaccines can be delivered to the target lymphoid tissues and cells by nanocarriers and nanoplatforms to increase the potency and durability of antitumor immunity and minimize negative side effects. Nanovaccines use nanoparticles (NPs) as carriers and/or adjuvants, offering the advantages of optimal nanoscale size, high stability, ample antigen loading, high immunogenicity, tunable antigen presentation, increased retention in lymph nodes, and immunity promotion. To induce antitumor immunity, cancer vaccines rely on tumor antigens, which are administered in the form of entire cells, peptides, nucleic acids, extracellular vesicles (EVs), or cell membrane-encapsulated NPs. Ideal cancer vaccines stimulate both humoral and cellular immunity while overcoming tumor-induced immune suppression. Herein, we review the key properties of nanovaccines for cancer immunotherapy and highlight the recent advances in their development based on the structure and composition of various (including synthetic and semi (biogenic) nanocarriers. Moreover, we discuss tumor cell-derived vaccines (including those based on whole-tumor-cell components, EVs, cell membrane-encapsulated NPs, and hybrid membrane-coated NPs), nanovaccine action mechanisms, and the challenges of immunocancer therapy and their translation to clinical applications.

Advances in Cancer Nanovaccines: Harnessing Nanotechnology for Broadening Cancer Immune Response

Many advances have been made recently in the field of cancer immunotherapy, particularly with the development of treatments such as immune checkpoint inhibitors and adoptive cellular immunotherapy. The efficacy of immunotherapy is limited, however, owing to high levels of tumor heterogeneity and the immunosuppressive environments of advanced malignant tumors. Therefore, therapeutic anticancer vaccines have gradually become powerful tools for inducing valid antitumor immune responses and regulating the immune microenvironment. Tumor vaccines loaded in nanocarriers have become an indispensable delivery platform for tumor treatment because of their enhanced stability, targeting capability, and high level of safety. Through a unique design, cancer nanovaccines activate innate immunity and tumor-specific immunity simultaneously. For example, the design of cancer vaccines can incorporate strategies such as enhancing the stability and targeting of tumor antigens, combining effective adjuvants, cytokines, and immune microenvironment regulators, and promoting the maturation and cross-presentation of antigen-presenting cells (APCs). In this review, we discuss the design and preparation of nanovaccines for remodeling tumor antigen immunogenicity and regulating the immunosuppressive microenvironment.

Recent advancements in immunotherapy of melanoma using nanotechnology-based strategies

Melanoma is a malignant tumor that accounts for the deadliest form of skin cancers. Despite the significant efforts made recently for development of immunotherapeutic strategies including using immune checkpoint inhibitors and cancer vaccines, the clinical outcomes are unsatisfying. Different factors affect efficient cancer immunotherapy such as side-effects, immunosuppressive tumor microenvironment, and tumor heterogeneity. In the past decades, various nanotechnology-based approaches have been developed to enhance the efficacy of cancer immunotherapy, in addition to diminishing the toxicity associated with it. Several studies have shown that proper application of nanomaterials can revolutionize the outcome of immunotherapy in diverse melanoma models. This review summarizes the recent advancement in the integration of nanotechnology and cancer immunotherapy in melanoma treatment. The importance of nanomaterials and their therapeutic advantages for patients with melanoma are also discussed.

Nanotechnology for next-generation cancer immunotherapy: State of the art and future perspectives

Over the past decade, immunotherapy aiming to activate an effective antitumor immune response has ushered in a new era of cancer treatment. However, the efficacy of cancer immunotherapy is limited by low response rates and high systemic toxicity. Nanotechnology is an encouraging platform for the development of next-generation cancer immunotherapy to effectively treat advanced cancer. Nanotechnology-enabled immunotherapy has remarkable advantages, ranging from the increased bioavailability and stability of immunotherapeutic agents to the enhanced activation of immune cells and favorable safety profiles. Nanotechnology-enabled immunotherapy can target solid tumors through reprogramming or stimulating immune cells (i.e., nanovaccines); modulating the immunosuppressive tumor microenvironment; or targeting tumor cells and altering their responses to immune cells to generate effective antitumor immunity. In this Oration, I introduce the advanced strategies currently being pursued by our laboratory and other groups to improve the therapeutic efficacy of cancer immunotherapy and discuss the potential challenges and future directions.

PLGA Particles in Immunotherapy

Poly(lactic-co-glycolic acid) (PLGA) particles are a widely used and extensively studied drug delivery system. The favorable properties of PLGA such as good bioavailability, controlled release, and an excellent safety profile due to the biodegradable polymer backbone qualified PLGA particles for approval by the authorities for the application as a drug delivery platform in humas. In recent years, immunotherapy has been established as a potent treatment option for a variety of diseases. However, immunomodulating drugs rely on targeted delivery to specific immune cell subsets and are often rapidly eliminated from the system. Loading of PLGA particles with drugs for immunotherapy can protect the therapeutic compounds from premature degradation, direct the drug delivery to specific tissues or cells, and ensure sustained and controlled drug release. These properties present PLGA particles as an ideal platform for immunotherapy. Here, we review recent advances of particulate PLGA delivery systems in the application for immunotherapy in the fields of allergy, autoimmunity, infectious diseases, and cancer.

Engineered tumor cell-derived vaccines against cancer: The art of combating poison with poison

Tumor vaccination is a promising approach for tumor immunotherapy because it presents high specificity and few side effects. However, tumor vaccines that contain only a single tumor antigen can allow immune system evasion by tumor variants. Tumor antigens are complex and heterogeneous, and identifying a single antigen that is uniformly expressed by tumor cells is challenging. Whole tumor cells can produce comprehensive antigens that trigger extensive tumor-specific immune responses. Therefore, tumor cells are an ideal source of antigens for tumor vaccines. A better understanding of tumor cell-derived vaccines and their characteristics, along with the development of new technologies for antigen delivery, can help improve vaccine design. In this review, we summarize the recent advances in tumor cell-derived vaccines in cancer immunotherapy and highlight the different types of engineered approaches, mechanisms, administration methods, and future perspectives. We discuss tumor cell-derived vaccines, including whole tumor cell components, extracellular vesicles, and cell membrane-encapsulated nanoparticles. Tumor cell-derived vaccines contain multiple tumor antigens and can induce extensive and potent tumor immune responses. However, they should be engineered to overcome limitations such as insufficient immunogenicity and weak targeting. The genetic and chemical engineering of tumor cell-derived vaccines can greatly enhance their targeting, intelligence, and functionality, thereby realizing stronger tumor immunotherapy effects. Further advances in materials science, biomedicine, and oncology can facilitate the clinical translation of tumor cell-derived vaccines.

Advances in the Application of Nanomaterials to the Treatment of Melanoma

Melanoma can be divided into cutaneous melanoma, uveal melanoma, mucosal melanoma, etc. It is a very aggressive tumor that is prone to metastasis. Patients with metastatic melanoma have a poor prognosis and shorter survival. Although current melanoma treatments have been dramatically improved, there are still many problems such as systemic toxicity and the off-target effects of drugs. The use of nanoparticles may overcome some inadequacies of current melanoma treatments. In this review, we summarize the limitations of current therapies for cutaneous melanoma, uveal melanoma, and mucosal melanoma, as well as the adjunct role of nanoparticles in different treatment modalities. We suggest that nanomaterials may have an effective intervention in melanoma treatment in the future.

Cancer Immunotherapy and Delivery System: An Update

With an understanding of immunity in the tumor microenvironment, immunotherapy turns out to be a powerful tool in the clinic to treat many cancers. The strategies applied in cancer immunotherapy mainly include blockade of immune checkpoints, adoptive transfer of engineered cells, such as T cells, natural killer cells, and macrophages, cytokine therapy, cancer vaccines, and oncolytic virotherapy. Many factors, such as product price, off-target side effects, immunosuppressive tumor microenvironment, and cancer cell heterogeneity, affect the treatment efficacy of immunotherapies against cancers. In addition, some treatments, such as chimeric antigen receptor (CAR) T cell therapy, are more effective in treating patients with lymphoma, leukemia, and multiple myeloma rather than solid tumors. To improve the efficacy of targeted immunotherapy and reduce off-target effects, delivery systems for immunotherapies have been developed in past decades using tools such as nanoparticles, hydrogel matrix, and implantable scaffolds. This review first summarizes the currently common immunotherapies and their limitations. It then synopsizes the relative delivery systems that can be applied to improve treatment efficacy and minimize side effects. The challenges, frontiers, and prospects for applying these delivery systems in cancer immunotherapy are also discussed. Finally, the application of these approaches in clinical trials is reviewed.