Table 1 Comparison of drug loading approaches

Passive Loading

Simple method

Drug can alter cell properties

Uses concentration gradient

Passive unloading

Not suitable for hydrophobic drugs

Receptor mediated loading

Direct targeting toward receptor

May require use of nanoparticles

Expensive ligands

Physical loading

Tried and tested methods

Invasive

Impacts cell viability

Liposome-mediated Loading

Well researched

Expensive method when scaled up

Can be enhanced by targeting receptors/surface modification

Protects the delivered drug

EV vector loading

Naïve MSC EVs are therapeutic

Not fully characterised

Easily isolated

Poor targeting in some diseases

Proven to carry cargo from parent cell

Can be difficult to obtain large numbers