The developed nano-immunostimulant can direct reactive oxygen species towards tumour cells and induce cell death.
Immunotherapy involves the use of one’s immune system to fight cancer and in recent years, have quickly risen to become a standard first-line treatment for certain types of cancer. Crucial to enhancing the therapeutic effect is to stimulate the patient’s immune system to produce a strong, effective, and lasting tumour-specific immune response. Engineered nanoplatforms have displayed incredible potential in enhancing anti-tumour responses. Yet, the current treatment platforms only trigger the immune system in a transient and restricted manner, which means inadequate immune activation and low therapeutic efficacy.
Now, a research group led by Professor Zhang Yun from Fujian Institute of Research on the Structure of Matter of the Chinese Academy of Sciences designed a novel targeted nano-immunostimulant based on persistent luminescence nanoparticles for effective and sustainable anti-tumour immune response.
To construct the nano-immunostimulant (ZGS-Si-Pc@HA), the researchers coupled the persistent luminescence nanoparticles with a photosensitiser and hyaluronic acid. This ensured immune stimulation would be sustained upon irradiation with biological window light.
Applying a simple acetylacetonate combustion method, the group prepared a renewable near-infrared (NIR)-emitting Zn3Ga2Sn2O10: Cr3+, Eu3+(ZGS) persistent luminescence nanoparticles. Subsequent functional modifications with silicon phthalocyanine (Si-Pc) and hyaluronic acid (HA), the developed nano-immunostimulant ZGS-Si-Pc@HA was found to continually drive reactive oxygen species towards tumour cells and induce immunogenic cell death.
When combined with the clinically approved PD-L1 checkpoint blockade therapy, ZGS-Si-Pc@HA was able to improve the therapeutic effect by effectively eradicating primary tumours that are exposed to reactive oxygen species, and hindering distant tumour growth by triggering anti-tumour immune responses.
Furthermore, the group reported a significant immunological memory effect in mice following treatment. This effectively protects mice from rechallenged cancer cells, thereby attaining a synergistic, efficient, and long-lasting anti-tumour immune response.
The group’s work with nano-immunostimulants not only presents us with a new way to improve cancer immunotherapy but also sheds light on how we can approach cancer metastasis and recurrence clinically. [APBN]
Source: Wang et al. (2021). Sustained Antitumor Immunity Based on Persistent Luminescence Nanoparticles for Cancer Immunotherapy. Advanced Functional Materials, 2106884.