Table 2.
Overview of the different transfection technologies for gene delivery applications.
| Strategy | Description | Pros | Cons | |
|---|---|---|---|---|
| Physical/mechanical methods [27,29,42] | electroporation | application of an electric field by voltage pulses to induce transient cell membrane poration | high efficiency; low costs; high reproducibility; ability to transfer large size DNA | tissue/cell damage; invasiveness; some DNA instability |
| sonoporation | use of highly-focused ultrasounds to trigger transient cell membrane poration | non-invasiveness; possibility to be used in combination with microbubbles/non-viral vectors | low efficiency; low reproducibility; tissue/cell damage | |
| optoporation | use of short ultra-focused laser pulses to induce transient cell membrane poration | high efficiency; high spatial precision | tissue/cell damage; low irradiation area; poor penetration of the laser pulses | |
| magnetofection | application of a magnetic field to ease the transfer of NAs-coated paramagnetic particles into cells | high efficiency; non-invasiveness; possibility to be used in combination with non-viral vectors | poor efficiency with naked DNA; possible agglomeration of magnetic particles | |
| microinjection | direct injection of NAs into single cells by means of a needle | high efficiency; simplicity; reproducibility; low cytotoxicity; ability to transfer large size DNA | time consuming; inability to transfect large number of cells | |
| gene gun | propulsion of NAs-coated particles towards the target site | high efficiency; safety | tissue/cell damage; poor penetration of particles | |
| Viral vectors [2,39,43,44] | adenoviruses (AdVs) | non-enveloped dsDNA–virus able to carry ≤8 kbp DNA | efficient in a broad range of host cells | high immunogenicity; transient expression |
| adeno-associated viruses (AAVs) | non-enveloped recombinant ssDNA–virus with a small carrying capacity (≤4 kbp) | efficient in a broad range of host cells; non-inflammatory/pathogenic | small carrying capacity | |
| retroviruses | enveloped ssRNA-carrying virus with ≤8 kbp RNA capacity | long-term expression | limited tropism to dividing cells; random integration | |
| lentiviruses | enveloped ssRNA-carrying virus with ≤8 kbp RNA capacity | efficient in a broad range of host cells; long-term expression | potential oncogenic responses | |
| herpes simplex viruses (HSV)-1 | enveloped dsDNA–virus with >30 kbp carrying capacity | large packing capacity; efficient in a broad range of host cells | potential inflammatory responses; transient expression | |
| Non-viral vectors [11,45,46,47,48] | inorganic nanoparticles | metal-based nanoparticles of different size and shapes | possibility of functionalization; low cytotoxicity | instability; toxicity |
| cation lipids | lipids able to self-assemble with NAs to give lipoplexes | tunable features; safety; low cytotoxicity | low transfection efficiency | |
| cationic polymers | polymers able to self-assemble with NAs to give polyplexes | tunable features; possibility of functionalization; mild cytotoxicity; stability in protein-rich media; low cytotoxicity | low transfection efficiency | |