title: Antibacterial efficiency of vermiculite/chlorhexidine nanocomposites and results of the in vivo test of harmlessness of vermiculite.
abstract: Clay minerals have been proposed as very useful materials for modulating drug delivery. These are the commonly used materials in pharmaceutical production both as inorganic carriers or active agents. We focused on the development of suitable long-acting material for local treatment of oral infection where clay minerals act as inorganic drug carriers. Organovermiculites with antibacterial activity were prepared by ion exchange reactions using different concentrations of chlorhexidine diacetate. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal analysis (TGA). The antibacterial activity was evaluated by finding the minimum inhibitory concentration (MIC). All studied organoclays possessed good antibacterial activity after 24h exposure against Escherichia coli, Enterococcus faecalis and particularly against Staphylococcus aureus. Pseudomonas aeruginosa however proved very resistant as only the sample with the highest concentration of CA that successfully inhibited bacterial growth. Furthermore, clay mineral vermiculite was subjected to in vivo toxicological analysis and its influence on gastrointestinal tract during its oral application was investigated. Tissue samples from buccal mucosa, tongue, esophagus, stomach, terminal duodenum, small intestine, caecum, distal colon and liver were subjected to histological examination, both macroscopically and microscopically. Neither systemic nor local reactions were observed. Therefore the toxicity of vermiculite to a mammal model organism can be excluded.
authors: Nanotechnology Centre, VŠB - Technical University of Ostrava, 17. listopadu 15/2172, CZ-708 33 Ostrava, Poruba, Czech Republic; IT4Innovations Centre of Excellence, VŠB - Technical University of Ostrava, 17. listopadu 15/2172, CZ-708 00 Ostrava, Poruba, Czech Republic. Electronic address: sylva.holesova@vsb.cz.
authors: Sylva
authors: S
authors: Holešová
authors: Department of Maxillofacial Surgery, University Hospital Ostrava, 17. listopadu 1790/5, CZ-708 00 Ostrava, Poruba, Czech Republic.
authors: Jan
authors: J
authors: Stembírek
authors: Department of Human Pharmacology and Toxicology, University of Veterinary and Pharmaceutical Sciences Brno, Palackého 1/3, CZ-612 42 Brno, Czech Republic.
authors: Ladislava
authors: L
authors: Bartošová
authors: Department of Pathology, Masaryk Memorial Cancer Institute, Žlutý kopec 7, CZ-65653 Brno, Czech Republic.
authors: Gabriela
authors: G
authors: Pražanová
authors: Nanotechnology Centre, VŠB - Technical University of Ostrava, 17. listopadu 15/2172, CZ-708 33 Ostrava, Poruba, Czech Republic; IT4Innovations Centre of Excellence, VŠB - Technical University of Ostrava, 17. listopadu 15/2172, CZ-708 00 Ostrava, Poruba, Czech Republic.
authors: Marta
authors: M
authors: Valášková
authors: Nanotechnology Centre, VŠB - Technical University of Ostrava, 17. listopadu 15/2172, CZ-708 33 Ostrava, Poruba, Czech Republic; IT4Innovations Centre of Excellence, VŠB - Technical University of Ostrava, 17. listopadu 15/2172, CZ-708 00 Ostrava, Poruba, Czech Republic.
authors: Magda
authors: M
authors: Samlíková
authors: Institute of Public Health Ostrava, Centre of Clinical Laboratories, Partyzánské náměstí 7, CZ-702 00 Ostrava, Czech Republic.
authors: Erich
authors: E
authors: Pazdziora
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects; D002710:Chlorhexidine / Q000737:chemistry / Q000494:pharmacology*; D041981:Gastrointestinal Tract / Q000187:drug effects; D008297:Male; D008422:Materials Testing; D009092:Mucous Membrane / Q000187:drug effects; D053761:Nanocomposites / Q000737:chemistry* / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000538:Aluminum Silicates; D000900:Anti-Bacterial Agents; C003760:vermiculite; D002710:Chlorhexidine
keywords: Antibacterial activity; Histological examination; In vivo tests; Organovermiculites