Περίληψη:
The oregano leaves’ extract (ORLE) was used for the formation of silver nanoparticles
(AgNPs(ORLE)). ORLE and AgNPs(ORLE) (2 mg/mL) were dispersed in polymer hydrogels to give
the pHEMA@ORLE_2 and pHEMA@AgNPs(ORLE)_2 using hydroxyethyl–methacrylate (HEMA).
The materials were characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction
analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), derivative thermogravimetry/differential scanning calorimetry (DTG/DSC), ultraviolet (UV-Vis), and attenuated total
reflection mode (ATR-FTIR) spectroscopies in solid state and UV–Vis in solution. The crystallite size
value, analyzed with XRPD, was determined at 20 nm. The antimicrobial activity of the materials
was investigated against Gram-negative bacterial strains Pseudomonas aeruginosa (P. aeruginosa) and
Escherichia coli (E. coli). The Gram-positive ones of the genus of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) are known to be involved in microbial keratitis by the
means of inhibitory zone (IZ), minimum inhibitory concentration (MIC), and minimum bactericidal
concentration (MBC). The IZs, which developed upon incubation of P. aeruginosa, E. coli, S. epidermidis,
and S. aureus with paper discs soaked in 2 mg/mL of AgNPs(ORLE), were 11.7 ± 0.7, 13.5 ± 1.9,
12.7 ± 1.7, and 14.3 ± 1.7 mm. When the same dose of ORLE was administrated, the IZs were
10.2 ± 0.7, 9.2 ± 0.5, 9.0 ± 0.0, and 9.0 ± 0.0 mm. The percent of bacterial viability when they were
incubated over the polymeric hydrogel discs of pHEMA@AgNPs(ORLE)_2 was interestingly low
(66.5, 88.3, 77.7, and 59.6%, respectively, against of P. aeruginosa, E. coli, S. epidermidis, and S. aureus) and those of pHEMA@ORLE_2 were 89.3, 88.1, 92.8, and 84.6%, respectively. Consequently,
pHEMA@AgNPs(ORLE)_2 could be an efficient candidate toward the development of non-infectious
contact lenses.
Συγγραφείς:
A. Meretoudi, C.N. Banti, P.K. Raptis, C. Papachristodoulou, N. Kourkoumelis, A.A. Ikiades, P. Zoumpoulakis, T. Mavromoustakos, S. Hadjikakou
