Amoxicillin loaded bentonite, advanced low-cost antibacterial and environmentally friendly materials

Abstract

In this paper, natural bentonite (N-BENT) from the west of Algeria was used to prepare new inorganic-organic hybrid materials by accommodating amoxicillin (AMO) as a biological molecule in its interlayer space. The incorporation of AMO within the structure of bentonite was carried out through an ion exchange process between the interlayer's sodium and potassium cations, and the biological AMO molecules leading to two hybrids AMO1@BENT and AMO2@BENT materials with different AMO exchange rates. The intercalation of AMO between the aluminosilicate layers of bentonite material was confirmed by X-ray diffraction (XRD) analysis which showed that the basal spacing of bentonite shifted from 12.39 Å to ∼15 Å for both obtained hybrid materials. Other characterization methods such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and UV–Visible (UV-Vis) spectroscopy validated the intercalation of AMO in the bentonite and explained the phenomenon occurred during this intercalation process. The prepared materials were tested against gram-positive which are Bacillus subtilis (B. subtilis), Bacillus cereus (B. cereus) and Methicillin-resistant staphylococcus aureus (MRSA) and the gram-negative bacteria which are Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae), the results exhibited a very high antibacterial activity against the six bacteria. Indeed, an inhibition diameter as high as 55mm was obtained in the case of pathogenic MRSA bacteria. Furthermore, AMO2@BENT material is still very active against pathogenic MRSA bacteria after several reuses. All these results could make these low-cost hybrid materials exploitable in many different fields such as medicine, biology and the environment.