Because of their nano-size, biological compatibility, and ability to precisely
engineer antigens displayed, payloads packaged, and destinations targeted, nanobiomaterials are gaining traction as next-generation therapeutic tools. Oncolytic viruses
were the first to be exploited in cancer immunotherapy because these are natural cell
killers and, in some cases, highly selective for cancerous cells. Further, oncolytic
viruses can be engineered to encode immune-stimulators and therapeutic genes.
However, for oncolytic viruses to work, it is essential to develop these as viable viruses
with the ability to infect. This raises safety concerns and poses hurdles in regulatory
approval. To circumvent this limitation, non-replicating viruses and virus-like particles
have been explored for immunotherapeutic applications. The advantage of these is their
inability to infect mammals, thereby eliminating bio-safety concerns. Nonetheless,
concerns related to toxicity need to be addressed in each case. Several virus-like
particle candidates are currently in preclinical development stages and show promise
for clinical use via intertumoral administration, also referred to as vaccination in situ.
In cases where in situ administration is not possible due to the absence of solid tumours
or inaccessibility of the tumour, nano-biomaterials for systemic administration are
desired, and extracellular vesicles fit this bill. Exosomes, in particular, can provide
controlled abscopal effects – a property desirable for the treatment of metastatic cancer.
This chapter discusses the state-of-the-art in the development of nano-biomaterials for
immunotherapy. With a plethora of candidates in development and over two hundred
clinical trials ongoing worldwide, nanobiomaterials hold great promise as effective
cancer immunotherapies with minimal side effects.
Keywords: Adenovirus, AAV, Cancer vaccines, Checkpoint inhibitors, CPMV, Exosomes, Gene therapy, Immune suppression, Immunotherapy, In-situ vaccine, Nanoparticle, Oncolytic virus, Tumour micro-environment, Tumour remission, TVEC, VLP, Virus-like particle