Table 2 ∣.
Characteristics of selected delivery strategies for cancer immunotherapies
| Delivery technology | Classes of immunotherapy |
Advantages | Limitations |
|---|---|---|---|
| In vivo nanoparticle delivery to immune cells | • Cytokines • Checkpoint inhibitors • Agonistic antibodies • Engineered T cells |
• Surface functionalization with targeting agents • Localized delivery • Cargo protection |
• Premature drug release • Nanoparticle stability • Delivery to off-target clearance organs • Systemic toxicity |
| Ex vivo T cell functionalization with nanoparticles | • Cytokines • Vaccines • Engineered T cells |
• Innate tumour infiltration • Improved drug delivery • Can be engineered ex vivo or in vivo |
• Long production time • Short drug release profiles • Cell death after administration • Complex manufacturing |
| Controlled release systems | • Cytokines • Checkpoint inhibitors • Agonistic antibodies |
• Extended therapy timeline • Cargo protection • Low required doses • Localized delivery following intravenous injection |
• Difficult to control release profiles • Toxicities from off-target release • Potentially require surgical implantation • Acidification can degrade cargo |
| Biomaterial implant scaffolds | • Cytokines • Vaccines • Engineered T cells |
• In situ dendritic cell activation • Delivery of dendritic cell attractants • Implant functionalization with antigen • Controlled release profiles • Provides physical structure for cells |
• Potential toxicity from the implant material • Need to define specific antigens • Potential rejection of loaded adjuvant • Requires surgery |
| Injectable biomaterial scaffolds | • Cytokines • Checkpoint inhibitors • Neoantigens |
• Minimally invasive • No surgery required • Controlled release of loaded cargo • Delivery directly to the tumour |
• Early stages of development • Requires extensive characterization for biodegradation profile • May require large gauge needle |
| Transdermal delivery systems | • Checkpoint inhibitors • Neoantigens |
• Sustained release • Low required doses • Local delivery directly to the tumour • Minimally invasive • Bioresponsive |
• Small treatment area • Bioavailability and biocompatibility are unknown • Can be used only for tumours close to the skin • Complex manufacturing |