Cancer immunotherapy: nanodelivery approaches for immune cell targeting and tracking

Abstract

Cancer is one of the most common diseases afflicting people globally. New therapeutic approaches are needed due to the complexity of cancer as a disease. Many current treatments are very toxic and have modest efficacy at best. Increased understanding of tumor biology and immunology has allowed the development of specific immunotherapies with minimal toxicity. It is important to highlight the performance of monoclonal antibodies, immune adjuvants, vaccines and cell-based treatments. Although these approaches have shown varying degrees of clinical efficacy, they illustrate the potential to develop new strategies. Targeted immunotherapy is being explored to overcome the heterogeneity of malignant cells and the immune suppression induced by both the tumor and its microenvironment. Nanodelivery strategies seek to minimize systemic exposure to target therapy to malignant tissue and cells. Intracellular penetration has been examined through the use of functionalized particulates. These nano-particulate associated medicines are being developed for use in imaging, diagnostics and cancer targeting. Although nano-particulates are inherently complex medicines, the ability to confer, at least in principle, different types of functionality allows for the plausible consideration these nanodelivery strategies can be exploited for use as combination medicines. The development of targeted nanodelivery systems in which therapeutic and imaging agents are merged into a single platform is an attractive strategy. Currently, several nanoplatform-based formulations, such as polymeric nanoparticles, micelles, liposomes and dendrimers are in preclinical and clinical stages of development. Herein, nanodelivery strategies presently investigated for cancer immunotherapy, cancer targeting mechanisms and nanocarrier functionalization methods will be described. We also intend to discuss the emerging nano-based approaches suitable to be used as imaging techniques and as cancer treatment options.

Nanoparticle Functionalization and Its Potentials for Molecular Imaging

“…Immunotherapies for cancer can be done using NPs which help us to keep in track the immune cells useful during metastasis 91. When the energy absorbed is emitted as heat radiation then PDT is carried out to lyse the cells while imaging.…”

A Systematic Overview of Cancer Immunotherapy: An Emerging Therapy

“…They are not tumor specific and their use may result in autoimmunity against normal tissue expressing that Antigen. Examples include MAGE, GAGE, and NY-ESO1 [21]. Despite the ability of our immune system to recognize unique antigens expressed by tumor cells, they also can avoid immune attack by employing several "tricks" termed as "tumor immune escape".…”

“…It was seen that the patients who received Herceptin treatment generated effective T cell responses. Additionally, mAbs may activate components of the immune system via Fc portion based interactions eventually promoting antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) by macrophages and NK cells [21]. Herceptin is known to mediate ADCC via NK cells and monocytes [26].…”

“…One obvious drawback with the use of mAbs in humans would be that the immune system may recognize these mAbs as foreign and eventually be destroyed by the body's immune system. But over the years, researchers have surmounted this obstacle by designing "chimeric" or humanized antibodies achieved by replacing some parts of the mouse antibody proteins with human proteins [9,21]. Additional limitations of mAb therapy are listed in the (Table 1).…”

“…Some examples include Herceptin, Avastin, Rituxan, Campath, Zevalin [21]. Monoclonal Antibodies (mAb) are the most widely used form of targeted cancer immunotherapy in clinic today [25].…”