Table 1 The advantages and disadvantages of different types of exosomes

Cell-secreted exosomes

Human embryonic kidney cells

Ease of growth; non-demanding maintenance conditions; high transfection efficiency; ideal host cells for membrane modification through gene manipulation

Immune inert

[23]

Cancer cells

Large secretion; targeting homotypic tumor

Have a less ideal pharmacokinetic profile; be involved in tumour development and metastasis; having potential safety issues

[30]

Immune cells (e. g. macrophage cells, dendritic cells, natural killer cells)

Reduced immunogenicity; inducing potent cellular immune responses; containing killer proteins and cytotoxic molecules to inhibit tumour growth; penetrating the blood–brain barrier

Lack of understanding of mechanisms regarding how exosomal components interact with acceptor cells

[10]

Stem cells (e. g. mesenchymal stem cells)

Immune regulation characteristics; low production cost; good homing and penetrating ability

The unclear cargo composition of exosomes and biological behavior mechanism

[31, 32]

Blood-derived exosomes

Blood

Wide source and easy access; reduced unexpected mutations in cell culture; no occurring horizontal gene transfer; high transfection efficiency; natural brain targeting ability

Not determined

[33]

Food-derived exosomes

Milk-derived exosomes

Rich sources; crossing through the gastrointestinal tract via the neonatal Fc receptor; improving the oral bioavailability of drugs; improving the effectiveness and stability of drugs; improving human and mouse intestinal cells

Variation in shape, size, and cargo contents of exosomes; the unclear mechanism of the absorption, movement, and action

[34–36]

Plants-derived exosomes (e. g. grape, strawberry, lemon)

Rich sources; have the stability in the digestive environment

Less understanding of the ability in the process; the unclear mechanism of the absorption, movement, and action

[36, 37]