9.2–28.7 kDa were able to completely inhibit DNA migration at a N:P ratio of 5:1
(higher ratios than for PAEM, containing primary amines [177]). At N:P ratios
<15:1, the size of PHisA polyplexes decreased with increasing molecular weights
from 9.2 to 17.5 kDa, whereas 17.5 and 28.7 kDa PHisA condensed DNA into
comparable particle sizes at the same N:P ratios, as well as with increasing N:P
ratio. For PAEM (M n ¼ 9.8–33.7 kDa)-based polyplexes, the size was nearly
independent of chain length or charge ratio. At an N:P ratio of 15:1 and above,
all PHisA polymers were able to condense DNA into nanosized particles
(<220 nm), and the sizes as well as zeta potentials reached a plateau (moderate
positive surface charges of 13–19 mV). Although less toxic than PEI25K, by
comparing the transfection efficiency of pHisA 180 and pHisA 300 in COS-7 cells to
that of PEI25K at N:P ratio of 10, it was shown that their efficiency was slightly
higher than for PEI, which could be attributed to their higher buffering capacity.
Fig. 11 (a–g) Weak polycations without steric stabilizer: PMMA and methacrylamide derivatives
152
A. Bertin
(higher ratios than for PAEM, containing primary amines [177]). At N:P ratios
<15:1, the size of PHisA polyplexes decreased with increasing molecular weights
from 9.2 to 17.5 kDa, whereas 17.5 and 28.7 kDa PHisA condensed DNA into
comparable particle sizes at the same N:P ratios, as well as with increasing N:P
ratio. For PAEM (M n ¼ 9.8–33.7 kDa)-based polyplexes, the size was nearly
independent of chain length or charge ratio. At an N:P ratio of 15:1 and above,
all PHisA polymers were able to condense DNA into nanosized particles
(<220 nm), and the sizes as well as zeta potentials reached a plateau (moderate
positive surface charges of 13–19 mV). Although less toxic than PEI25K, by
comparing the transfection efficiency of pHisA 180 and pHisA 300 in COS-7 cells to
that of PEI25K at N:P ratio of 10, it was shown that their efficiency was slightly
higher than for PEI, which could be attributed to their higher buffering capacity.
Fig. 11 (a–g) Weak polycations without steric stabilizer: PMMA and methacrylamide derivatives
152
A. Bertin