Table 2 Different delivery methods for nanoparticles

Exosomes

Ability to cross natural barriers e.g. blood-brain barrier, autologous use for personalized medicine, provides biocompatibility to nanoparticles

Undesired effects due to the exosome components, lack of standardized production protocols, need to develop techniques for large scale cell culture

Chitosan

Less cytotoxic, biodegradable, easily metabolised by the kidneys

Plasma membrane coating

Provides immune evasion, red cell membranes have long circulation time, high versatility, easy fractionalization

Need for high yield methods for membrane derivation, lack of knowledge about all cell membrane components

Mesenchymal stem cells (MSCs)

Easy isolation and culture in vitro, non-immunogenicity, tissue regeneration capacity, tumour tropism, migration ability to site of damage, small and relatively homogenous size

Uncertain tumorigenic effect, high retention in the lungs after systemic administration, risk of occlusion of micro-vessels after systemic administration, development of autoantibodies after repeated injections, need for standardized protocols for isolation, purification, and characterization of cell of origin.