Nano Drug Delivery System for Tumor Immunotherapy: Next-Generation Therapeutics

Abstract

Tumor immunotherapy is an artificial stimulation of the immune system to enhance anti-cancer response. It has become a powerful clinical strategy for treating cancer. The number of immunotherapy drug approvals has been increasing in recent years, and many treatments are in clinical and preclinical stages. Despite this progress, the special tumor heterogeneity and immunosuppressive microenvironment of solid tumors made immunotherapy in the majority of cancer cases difficult. Therefore, understanding how to improve the intratumoral enrichment degree and the response rate of various immunotherapy drugs is key to improve efficacy and control adverse reactions. With the development of materials science and nanotechnology, advanced biomaterials such as nanoparticle and drug delivery systems like T-cell delivery therapy can improve effectiveness of immunotherapy while reducing the toxic side effects on non-target cells, which offers innovative ideas for improving immunity therapeutic effectiveness. In this review, we discuss the mechanism of tumor cell immune escape and focus on current immunotherapy (such as cytokine immunotherapy, therapeutic monoclonal antibody immunotherapy, PD-1/PD-L1 therapy, CAR-T therapy, tumor vaccine, oncolytic virus, and other new types of immunity) and its challenges as well as the latest nanotechnology (such as bionic nanoparticles, self-assembled nanoparticles, deformable nanoparticles, photothermal effect nanoparticles, stimuli-responsive nanoparticles, and other types) applications in cancer immunotherapy.

Exosomes: A potential tool for immunotherapy of ovarian cancer

“…Exosomes in the serum of patients with ovarian cancer can promote the role of regulatory T cells and inhibit the effect of immune system on tumors by expressing a variety of immunosuppressive factors, such as TGF-β1 and IL-10 ( 263 , 264 ). Additionally, exosomes isolated from the ascites of patients with ovarian cancer can promote apoptosis of peripheral blood lymphocytes and DCs ( 265 , 266 ).…”

Immunotherapy: cancer immunotherapy and its combination with nanomaterials and other therapies

“…PRRs are existent in peripheral macrophages or dendritic cells (DCs) and are delivered to draining lymph nodes or splenic immune organs. 99 However, converting cancer vaccines into efficient clinical treatments still constituted a challenge for decades because of the diversity of tumor antigens and the comparatively low immune response. 100 Nanomaterial carriers can effectively encapsulate antigens and adjuvants during tumor vaccine delivery through electrostatic or hydrophobic interactions, covalent binding, etc.…”

Advanced Generation Therapeutics: Biomimetic Nanodelivery System for Tumor Immunotherapy

“…TME, the decisive factor of anticancer efficiency, consists of extracellular matrix, myelogenous suppressor cells, tumor-associated macrophages (TAMs), tumor-infiltrating lymphocytes (TILs), regulatory T cells, cancer-associated fibroblasts and soluble protein molecules (transforming growth factor-β [TGF-β], indoleamine-2, 3-dioxygenase [IDO], cyclooxygenase-2 [COX-2] and epidermal growth factor). − Together, the TME is regulated into an immunosuppressive microenvironment (iTME), by these elements, aiming to support tumor growth and metastasis and limit the function of antigen-presenting cells and infiltrating T cells. In general, the iTME is in a state of immune escape.…”