title: PDMS-based porous particles as support beds for cell immobilization: bacterial biofilm formation as a function of porosity and polymer composition.
abstract: The objective of this work is to test the performance of new synthetic polydimethylsiloxane (PDMS)-based bed particles acting as carriers for bacteria biofilms. The particles obtained have a highly interconnected porous structure which offers a large surface adsorption area to the bacteria. In addition, PDMS materials can be cross-linked by copolymerization with other polymers. In the present work we have chosen two hydrophilic polymers: xanthan gum polysaccharide and tetraethoxysilane (TEOS). This versatile composition helps to modulate the interfacial hydrophobic/hydrophilic balance at the particle surface level and the roughness topology and pore size distribution, as revealed by scanning electron microscopy. Biofilm formation of a consortium isolated from a tannery effluent enriched in Sulphate Reducing Bacteria (SRB), and pure Acidithiobacillus ferrooxidans (AF) strains were assayed in three different bed particles synthesized with pure PDMS, PDMS-xanthan gum and PDMS-TEOS hybrids. Bacterial viability assays using confocal laser scanning fluorescence microscopy indicate that inclusion of hydrophilic groups on particle's surface significantly improves both cell adhesion and viability.
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencias Exactas y Naturales, Instituto de Química Física de Materiales, Ambiente y Energía, Universidad de Buenos Aires, Argentina.
authors.forename: M R
authors.initials: MR
authors.lastname: Fernández
authors.forename: M G
authors.initials: MG
authors.lastname: Casabona
authors.forename: V N
authors.initials: VN
authors.lastname: Anupama
authors.forename: B
authors.initials: B
authors.lastname: Krishnakumar
authors.forename: G A
authors.initials: GA
authors.lastname: Curutchet
authors.forename: D L
authors.initials: DL
authors.lastname: Bernik
mesh_terms: D042763:Acidithiobacillus / Q000502:physiology*; D001419:Bacteria / Q000166:cytology / Q000378:metabolism; D001422:Bacterial Adhesion / Q000502:physiology; D018441:Biofilms / Q000254:growth & development*; D018914:Cells, Immobilized / Q000502:physiology; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D010316:Particle Size; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D016062:Porosity; D012821:Silanes / Q000737:chemistry; D013431:Sulfates / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D004129:Dimethylpolysiloxanes; D011135:Polysaccharides, Bacterial; D012821:Silanes; D013431:Sulfates; C040733:tetraethoxysilane; C013830:baysilon; C002563:xanthan gum