Dan Eduard Mihaiescu, Alexandru Mihai Grumezescu*, Alice Sandra Buteica, Diana Elena Mogosanu, Paul Catalin Balaure, Oana Maria Mihaiescu, Vanessa Trăistaru, Bogdan Stefan Vasile: Bioassay and electrochemical evaluation of controlled release behavior of cephalosporins from magnetic nanoparticles. Digest Journal of Nanomaterials and Biostructures, 7(1):253 – 260, 2012.
Four antibiotics from the cephalosporin class were used for the evaluation of controlled release behaviour. Plasma processed magnetic nanoparticles (C-Fe) were characterized by HR-TEM. Cephalosporins were deposed on magnetic nanoparticles by adsorbtion and the antimicrobial activity of cephalosporins and C-Fe/cephalosporins (cephachlor, cefuroxime, cefotaxime, and ceftriaxone) was tested. Two collection strains: Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922, were used for assessing the antimicrobial activity of corre/shell type nanoparticles. Controlled release of nanoparticles deposed antibiotics was studied by using a biological assay and an electrochemical aproach. The antimicrobial effect and its time dependence of the C–Fe/cephalosporins was studied by difusimetric method, comparing the groth inhibition zones determined from the functionalised nanoparticles and standardized antibiotic discs. longer exposure times emphasizing the increasing effect. The conductimetric method revealed the controlled release by measuring suspension conductivity at various times. We can conclude that the obtained adsorption shell C-Fe/cephalosporin nanostructures can be used as carriers for the controlled release of cephalosporins.