National Institute of Standards and Technology (NIST) scientists have developed a novel combination of microscopes that can peer deep into tissue-engineering scaffolds and monitor the growth and differentiation of cells within those scaffolds.
Composed of biodegradable polymers or other building materials, scaffolds are seeded with cells that grow, multiply, and assemble into three-dimensional tissues. Whether the cells respond and organise as intended in this synthetic environment depends greatly on the composition, properties, and architecture of the scaffolds’ porous interiors.
Tools for simultaneously monitoring microstructure and cellular activity can help scientists to tease apart the essentials of this interactive relationship. In turn, such knowledge can speed development of tissue-engineered products ranging from skin replacements to substitute livers.
To build the new optical system, NIST scientist Joy Dunkers and her colleagues paired an optical coherence microscope – a high-resolution probe of the scaffold interior – with a confocal fluorescence microscope- used to track cells stained with a fluorescent dye. The instruments provide simultaneous images that can be merged to create a comprehensive rendering of microstructure and cellular activity. By stacking the sectional images that are obtained, they can create a top-to-bottom movie showing structural and cellular details throughout the scaffold’s volume.
Until now, scrutiny of this complicated, three-dimensional process has been limited to the top-most layers of the scaffolds used to coax and sustain cell development.
A complete technical description of the work can be found in the November issue of Optics Express: J. P. Dunkers, M. T. Cicerone, and N. R. Washburn, ‘Collinear optical coherence and confocal fluorescence microscopies for tissue engineering,’ Optics Express, Vol. 11, No. 23, pp. 3074-3079.