. 2024 Jan 4;11:1284630. doi: 10.3389/fbioe.2023.1284630

TABLE 3.

Half-maximal cytotoxic concentrations (CC₅₀) of nanoencapsulated naphthoquinones and their antimicrobial therapeutic indices.

Estimated indices	Cell lineage or bacterial strain	Formulations
Estimated indices	Cell lineage or bacterial strain	NQ1	NQ2	CNP-NQ1	CNP-NQ2
CC₅₀ (mg/mL)	HFF-1 (HTB-26)	0.005	0.03	132	1.1
TI	Staphylococcus aureus	0.01	0.1	104*	0.95
	ATCC 14458	0.01	0.1	104*	0.95
	Staphylococcus epidermidis ATCC 12228	0.04	0.2	100*	0.70
	Staphylococcus aureus	0.16	0.83	120*	-
	ATCC 29213	0.16	0.83	120*	-
	Streptococcus pyogenes	0.02	0.08	30*	-
	ATCC 19615	0.02	0.08	30*	-
	Pseudomonas aeruginosa	0.005	0.02	28*	-
	ATCC 15442**	0.005	0.02	28*	-

TI, Therapeutic index calculated as the CC₅₀/IC₅₀ ratio, where one asterisk (*) indicates TI ≥ 100 and > 27, 10-fold or 2.7-fold higher than the TI, value considered as safe, indicating that the antimicrobial agent may be safely used in human tissues. NQ1—3-chloromethylene-menadione, NQ2—2,3-dichloro-1, 4-naphthoquinone; CNP, chitosan nanocapsules, CNP-NQ1—NQ1-loaded chitosan nanocapsules (CNP-NQs). CNP-NQ2—NQ2-loaded chitosan nanocapsules. **Asterisk indicates that P. aeruginosa is a resistant pathogen to various commercial germicides.