Quaternary Ammonium Polyethyleneimine: Antibacterial Activity

Table 1

Characterization of QA-PEI nanoparticles at different degrees of alkylation prepared via reductive amination.

Code	Degree of alkylationa	Inhibition concentrationb	Elemental analysisc			C/Nd	Particlesize (nm)e	Zeta potential (mV)f
			%N	%C
A	1 : 1	40 𝜇g/mL	7.03	32.74	54.00	3.61	24 ± 10	85 ± 10
B	1 : 0.75	40 𝜇g/mL	9.05	33.63	49.25	3.16	116 ± 100	60 ± 31
C	1 : 0.5	80 𝜇g/mL	8.85	30.94	54.25	2.81	56 ± 25	72 ± 31
D	1 : 0.25	160 𝜇g/mL	9.26	29.60	53.70	2.45	108 ± 106	80 ± 47

Octanal was reacted with cross-linked PEI nanoparticles at various mole ratios via reductive amination followed by N-methylation under the same conditions as described in the experimental section.
a Mole ratio of reactants (primary amine of PEI monomer units/alkylating agent).
b Concentration of the tested compound used for a complete inhibition of >10⁵   S. aureus growth. c Found Nitrogen, Carbon, and Iodine content of QA-PEI (elemental analysis). d C/N was determined by elemental analysis of the alkylated samples before methylation step, whereas C/N of the nonalkylated PEI was found to be 2.26. e Apparent particle size of QA-PEI nanoparticles (diameter). f Zeta potential of QA-PEI nanoparticles.