Nano-Biomaterials for Immunotherapy Applications

 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