Advanced biomaterials for cancer immunotherapy

Abstract

Immunotherapy, as a powerful strategy for cancer treatment, has achieved tremendous efficacy in clinical trials. Despite these advancements, there is much to do in terms of enhancing therapeutic benefits and decreasing the side effects of cancer immunotherapy. Advanced nanobiomaterials, including liposomes, polymers, and silica, play a vital role in the codelivery of drugs and immunomodulators. These nanobiomaterial-based delivery systems could effectively promote antitumor immune responses and simultaneously reduce toxic adverse effects. Furthermore, nanobiomaterials may also combine with each other or with traditional drugs via different mechanisms, thus giving rise to more accurate and efficient tumor treatment. Here, an overview of the latest advancement in these nanobiomaterials used for cancer immunotherapy is given, describing outstanding systems, including lipid-based nanoparticles, polymer-based scaffolds or micelles, inorganic nanosystems, and others.

Keywords: cancer; dendritic cells (DCs); hydrogel; immunotherapy; liposomes; micelles; microneedles; nanobiomaterials; nanoparticles.

Fig. 1

Scheme of the cancer immunotherapy mechanism. After antigens are processed by immature dendritic cells (ImDCs), they are presented to T cells by mature dendritic cells (mDCs) through major histocompatibility complex (MHC) class I or MHC class II complexes binding to CD8⁺ or CD4⁺ T cells, separately. Simultaneously, mDCs also express costimulatory molecules and cytokines such as IFN-γ and IL-12 to synergistically stimulate T cells. CD8⁺ T cells further differentiate into cytotoxic T lymphocytes (CTLs), and CD4⁺ T cells further differentiate into IFN-γ secreting T-helper 1 (Th1) cells to assist in activating CD8 cells and other innate immune cells, such as natural killer (NK) cells, granulocytes or macrophages, to directly kill tumor cells

Fig. 2

Different biomaterials for cancer immunotherapy. Reprinted with permission from [2]

Fig. 3

Schematic depiction of an in situ DC vaccine using chimeric cross-linked polymersomes (CCPS) as adjuvants combined with PDT and ICD for the treatment of MC38 colorectal cancer. a Process of self-assembled nanoparticle formation. b Immune response in vivo after injection of CCPS/HPPH/DOX. Reprinted with permission from [98]

Fig. 4

AC-NPs have the capacity to inhibit distant B16F10 xenografts. a Schematic illustration of cancer immunotherapy promotion by using antigen-capturing nanoparticles (AC-NPs) combined with radiotherapy and αPD-1 treatment. b Average tumor growth curves of abscopal tumors in mice treated with different administrations. c The survival rate of the treated mice in b. Reprinted with permission from [172]

Fig. 5

PVAX immunotherapy for both recurrent and metastatic 4T1 tumors. a Schematic depiction of the manufacture of PVAX for cancer immunotherapy. b Average and individual tumor growth curves of recurrent 4T1 xenografts in mice treated with different formulations. c Survival curves of the mice bearing 4T1 recurrent tumors. d Average tumor growth curves of the distant tumors treated with different formulations. e Tumor-free percentages of the abscopal tumor. Reprinted with permission from [195]

Fig. 6

The MSR–PEI vaccine inhibits established tumors. a Schematic illustration of PEI and antigen adsorption. b Schematic depiction of the MSR vaccine and MSR–PEI vaccine. Tumor growth (c) and survival rate (d) of mice bearing E7-expressing TC-1 tumors rechallenged with TC-1 cells. e The survival rate of mice bearing E7-expressing TC-1 tumors treated with different formulations. Reprinted with permission from [220]

Fig. 7

Local immunotherapy for various tumors via microneedles. a Schematic illustration of immunotherapy utilizing microneedles. b Average tumor growth and survival rate of treated C57BL/6J mice in the BP tumor model. c Average tumor growth and survival rate of treated BALB/c mice in the 4T1 tumor model. d Average tumor growth and survival rate of C57BL/6J mice in established BP tumor models. e Average tumor growth and survival rate of BALB/c mice in established 4T1 tumor models. Reprinted with permission from [255]

Fig. 8

eCPMV immunotherapy for metastatic breast, colon, and ovarian tumors. a Photo and survival rate of mice in a metastatic breast tumor model. b Photo and survival rate of mice in a colon tumor model. c Photo and survival rate of mice with ID8-Defb29/Vegf-A ovarian cancer. Reprinted with permission from [267]