Comparative efficacy of cephradine-loaded silver and gold nanoparticles against resistant human pathogens

Figures & data

Figure 1. Chemical structure of cephradine.

Figure 2. Reaction optimisation of Ceph-Ag and Ceph-Au NPs.

Figure 3. Stability of Ceph-Ag and Ceph-Au NPs at different pH ranges.

Figure 4. Effects of temperature on the reaction kinetics of Ceph-Ag and Ceph-Au NPs.

Figure 5. Effect of brine on the stability of Ceph-Ag and Ceph-Au NPs.

Figure 6. FTIR analyses of (A) Ceph-Ag and (B) Ceph-Au NPs.

Figure 7. Mechanism of the interaction between AgNPs, AuNPs and cephradine [35].

Table 1. FTIR spectral assignment of free cephradine, Ceph-Ag NPs and Ceph-Au NPs.

Free cephradine	Ceph-Ag NPs	Ceph-Au NPs	Assignment
3500–2400 cm^−1	3500 cm^−1	3500 cm^−1	v (NH2)/(-OH)
1743 cm^−1	1743 cm^−1	------	v (O = C-NH2)
1625 cm^−1	1625 cm^−1	1548 cm^−1	v (C = C)
1361 cm^−1	1361 cm^−1	1361 cm^−1	v (-C-N)

Figure 8. TEM images of Ceph-Ag NPs.

Figure 9. TEM images of Ceph-Au NPs.

Figure 10. Particle size analyses of Ceph-Ag and Ceph-Au NPs using TEM images.

Figure 11. AFM images of cephradine capped with Ag nanoparticles.

Figure 12. AFM images of cephradine capped with Au nanoparticles.

Figure 13. Particle size analyses of Ceph-Ag and Ceph-Au NPs using XRD.

Table 2. Antimicrobial and Biofilm Inhibition Activities of Ceph-Ag and Ceph-Au NPs.

Organisms	Ceph-Au NPs			Ceph-Ag NPs			Cephradine
	Dose (μg/mL)		Biofilm % inhibition	Dose (μg/mL)		Biofilm % inhibition	MIC
	MIC	MBIC	AVG	MIC	MBIC	AVG
E. aerogenes	>500	500	19.25 ± 2.7	500	250	35.45 ± 3.9	128
E. faecalis	NR	NR	NR	NR	NR	NR	250
K. pneumoniae	500	250	32.18 ± 1.9	500	125	44.15 ± 3.8	250
P. mirabilis	NR	NR	NR	NR	NR	NR	NR
S. mutans	250	125	50.21 ± 3.1	125	62.5	48.52 ± 1.4	128
MRSA	500	125	61.25 ± 2.1	500	250	56.75 ± 2.5	500

MIC: minimum inhibitory concentration; MBIC: minimum biofilm inhibitory concentration; AVG: average; NR: No result; SD: standard deviation.

Table 3. Preformed biofilm eradication capability of Ceph-Ag and Ceph-Au NPs.

Organisms	Ceph-Au NPs			Ceph-Ag NPs
	Biofilm eradication dose (μg/mL)	Biofilm (%) eradication		Biofilm eradication dose (μg/mL)	Biofilm (%) eradication
		AVG	SD		AVG	SD
MRSA	500	29.28	3.4	500	24.19	1.4
K. pneumoniae		NA			NA
S. mutans	500	15.01	1.8	500	10.21	2.2

Ahmad T, Mahbood F, Sarwar R, et al. Synthesis of gemifloxacin conjugated silver nanoparticles, their amplified bacterial efficacy against human pathogen and their morphological study via TEM analysis. Artif Cells Nanomed Biotechnol. 2021;49(1):661–671.

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