Table 1.
Characteristics of non-viral siRNA delivery vehicles
| Vehicle | Aptamer | Cationic peptide | Polymer | Liposome |
|---|---|---|---|---|
| Capacity (siRNA/delivery molecule) | 1 | Several | ~several thousands | ~several thousands |
| Cellular internalization | +/− | + | + | + |
| Transfection efficiency | +/− | + | + | + |
| Potential cytotoxicity | − | − | +/− | +/− |
| Protection against degradation | − (chemical modification needed) | + | + | + |
| Surface modification | − | − | ++ | ++ |
| Mode of complexation | Direct conjugation | Ionic interaction/condensation | Condensation/encapsulation | Encapsulation |
| Ease of production | ++ | ++ | + | + |
| Biodegradability | ++ | ++ | +/− | ++ |
| Controlled release | − | − | +/− | − |
| Targeted delivery | yes | yes | yes | Yes |
| Duration of silencing | Transient | Transient | Transient | Transient |
| Immunogenicity | low | low | low | Low |
−, low; +/−, moderate; +, high; ++, very high