Table 1.
Summary of properties of different magnetic gene vector configurations.
| Test Conditions | Buffer Conditions | Formulation Configurations | ||
|---|---|---|---|---|
| 1st Configuration (SPIONs/PEI/DNA/HA) | 2nd Configuration (SPIONs/PEI/DNA + HA) | 3rd Configuration (SPIONs/PEI + DNA + HA) | ||
| Size (nm) (with the increase % of charge ratio HA:PEI) | water | 100–300 | 100–300 | 400–200 |
| NaCl | 1000–500 | >1000 | 500–2500 | |
| RPMI | 600–200 | 500–100 | 400–1600 | |
| RPMI + 10% FCS | 150–40 | 150–40 | 180–70 | |
| Charges (with the increase % of charge ratio HA:PEI, reduced the positive charges) | water | ~32 mV to ~−25 mV | ~32 mV to ~−25 mV | ~29 mV |
| NaCl | ~14 mV to ~−10 mV | ~9 mV to ~−10 mV | ~17 mV to ~2 mV | |
| RPMI | ~8 mV to ~−12 mV | ~8 mV to ~−15 mV | ~12 mV to ~−5 mV | |
| RPMI + 10% FCS | increase the positive charge (~−18 mV to ~−10 mV) | increase the positive charge (~−18 mV to ~−10 mV) | increase the positive charge (~−16 mV to ~−8 mV) | |
| DNA retardation (with the increase % of charge ratio HA:PEI) | water | >25% DNA released | partial DNA disassembly, but no free DNA | no DNA release or disassembly |
| NaCl | No release of DNA | No release of DNA | No release of DNA | |
| RPMI | No release of DNA | No release of DNA | No release of DNA | |
| RPMI + 10% FCS | partial DNA disassembly | partial DNA disassembly | no DNA release or disassembly | |
| DNA binding | 5% of charge ratio HA:PEI | 96% ± 3% | 94% ± 1% | 99% ± 0.5% |
| 100% of charge ratio HA:PEI | 95% ± 2% | 93% ± 3% | 99% ± 1% | |
| Stability against extracellular environment | + | +++ | ++ | |
| Stability against nuclease | + | +++ | ++ | |
Abbreviations—SPIONs: superparamagnetic iron oxide nanoparticles; PEI: polyethylenimine; HA: hyaluronic acid; FCS: foetal calf serum