Improving bacteria viability in metal oxide hosts via an alginate-based hybrid approach

M. PERULLINI; M. AMOURA; M. JOBBAGY; C. ROUX; J. LIVAGE; T. CORADIN; S. ALDABE BILMES

JOURNAL OF MATERIALS CHEMISTRY

ROYAL SOC CHEMISTRY

Año: 2011 vol. 21 p. 8026 - 8031

0959-9428

A two-step process relying on cell encapsulation in alginate beads followed by inorganic gelation fromcolloidal metal oxides was successfully applied to the immobilization of Escherichia coli bacteria in thepresence of boehmite and zirconium oxyhydroxide particles. In the case of the Al-based gel, the alginatebead obtained at low biopolymer content provides an efficient barrier against the encapsulation stress.In contrast, an increase in the alginate concentration together with the phosphate-inducedmineralization of the biopolymer bead is found necessary to maintain the viability of entrappedbacteria in Zr-based gels. Diffusion studies using model molecular and colloidal species put in evidencethat positively charged Zr-oligomers and ZrO2 nanoparticles may be involved in the cytotoxicity of theprecursor solution. This optimization of the encapsulation process allows the first observation of E. coligrowth within such metal oxide–alginate hybrid gels. Results presented in this work give a clearevidence that sol–gel based cell encapsulation can now be envisioned within a wide variety of metaloxide hosts through the optimization of the pre-encapsulation environment.