Living Bacterial Sacrificial Porogens to Engineer Decellularized Porous Scaffolds

Decellularization and cellularization of organs have emerged as disruptive methods in tissue engineering and regenerative medicine. Porous hydrogel scaffolds have widespread applications in tissue engineering, regenerative medicine and drug discovery as viable tissue mimics. However, the existing hydrogel fabrication techniques suffer from limited control over pore interconnectivity, density and size, which leads to inefficient nutrient and oxygen transport to cells embedded in the scaffolds. Here, we demonstrated an innovative approach to develop a new platform for tissue engineered constructs using live bacteria as sacrificial porogens. E.coli were patterned and cultured in an interconnected three-dimensional (3D) hydrogel network. The growing bacteria created interconnected micropores and microchannels. Then, the scafold was decellularized, and bacteria were eliminated from the scaffold through lysing and washing steps. This 3D porous network method combined with bioprinting has the potential to be broadly applicable and compatible with tissue specific applications allowing seeding of stem cells and other cell types

Interactions between two types of nanoparticles (nC(60) and TiO2) and porous media

19th Annual VM Goldschmidt Conference, Davos, SWITZERLAND, JUN 21, 2009International audienceno abstrac

Characterizing the impact of preparation method on fullerene cluster structure and chemistry

International audienceWe examined the physical and chemical characteristics of colloidal dispersions of fullerene materials (nC(60)) produced through several solvent exchange processes and through extended mixing in water only. The nC(60) produced via the different methods were unique from each other with respect to size, morphology. charge, and hydrophobicity. The greatest dissimilarities were observed between the nC(60) produced by extended mixing in water alone and the nC(60) produced by solvent exchange processes. The role of the respective solvents in determining the characteristics of the various nC(60) were attributed to differences in the solvent-C-60 interactions and the presence of the solvent as a residual in the nC(60) structure, indicating the significance of the solvent properties in determining the ultimate characteristics of the colloidal fullerene. Thus, fullerene C-60 that may become mobilized through natural processes (agitation in water) may behave in dramatically different ways than those produced through more artificial means. These results highlight the difficulties in generalizing nC(60) properties, particularly as they vary in potential toxicity considerations

Ecotoxicological effect of altered TiO2 nanocomposite on the earthworm, Eisenia fetida

19th Annual VM Goldschmidt Conference, Davos, SWITZERLAND, JUN 21, 2009International audienceno abstrac