Table 2.

Advantages and disadvantages of physical methods of nonviral gene delivery.

Techniques	Advantages	Disadvantages
Microinjection	Allows delivery of large amount of genetic material, convenient, simple, cost-effective, less toxic, and reproducible	Special handling technique is required and cannot be used for large number of cells transfection
Needle injection	Simple to perform and requires small amount of DNA	Therapeutic efficacy is quite low and is difficult to conduct
Jet gun	Noninvasive, safe, and easily controllable	Causes local tissue damage and efficiency is low
Gene gun	Nontoxic, highly effective, and allows gene delivery to cells that are difficult to transfect	Limited to superficial cells and cannot be used for gene delivery to cells where deep penetration is required
Electroporation	Fast, effective, reproducible, and allows delivery of large quantities of DNA	Requires surgery, risk of DNA damage due to exposure to high voltage, and highly localized
Nucleofection	Fast and efficient in cases where cell membranes are difficult to permeate	Very limited application for in vivo gene delivery and can be highly toxic
Sonoporation	Noninvasive, capable of reaching deep tissues and organs, can be used for specific local targets, and capable of crossing blood–brain barrier	Efficiency is relatively low and target cells can be damaged
Hydrodynamic gene transfer	Simple and very efficient in deliver of gene to liver cells	Injection volume required is very large and clinically not feasible
Magnetoporation	Noninvasive and capable of reaching cells that are deep and demand complex transfection	Special equipment is required, preparation of magnetic vectors is complex, and magnetic reagent can cause toxicity after removal of magnetic field
Mechanical Massage	Simple, noninvasive, and easy to apply	Efficiency is low and application is not yet available for humans