Nicole H. Levi

C60-Fullerenes: detection of intracellular photoluminescence and lack of cytotoxic effects

We have developed a new method of application of C60 to cultured cells that does not require water-solubilization techniques. Normal and malignant cells take-up C60 and the inherent photoluminescence of C60 is detected within multiple cell lines. Treatment of cells with up to 200 μg/ml (200 ppm) of C60 does not alter morphology, cytoskeletal organization, cell cycle dynamics nor does it inhibit cell proliferation. Our work shows that pristine C60 is non-toxic to the cells, and suggests that fullerene-based nanocarriers may be used for biomedical applications.

Ink-Jet Printing of Encapsulated Bacteria

Even though viability for printed bacteria has been demonstrated, the effect of thermal ink-jet printing on cellular ultrastructures is unknown. Retention of viability is useful when colony growth is desired. However, when bacteria are isolated from a human infection they often exhibit characteristics that can be lost when grown in standard laboratory cultures. Ideally, individual bacteria from an infection could be printed and studied without extensive culturing or processing. We have investigated the gram-positive organism Staphylococcus aureus and the extracellular polymeric ultrastructure that encapsulates the bacterial cell. The capsule is composed of cell-wall associated polysaccharides. Our goal was to use ink-jet printing to spatially control the placement of S. aureus, without affecting the extracellular ultrastructure. Observation by scanning electron microscopy comparing the integrity and uniformity of encapsulated S. aureus before and after thermal ink-jet printing suggests that the capsule is disrupted, possibly completely removed, during printing.