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Abstract:
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To understand the chemistry of life processes in detail is largely a challenge of resolving them in their native , cellular environment . Cell culture , first developed a century ago , has proven to be an essential tool for reductionist studies of cellular biochemistry and development . However , for the technology of cell culture to move forward and address increasingly complex problems , in vitro environments must be refined to better reflect the cellular environment in vivo . This dissertation work has focused on the development of methods to define cellular microenvironments using the high resolution , 3D capabilities of multiphoton lithography . Here , site -specific photochemistry using multiphoton excitation is applied to the photocrosslinking of proteins , providing the means to organize bioactive species into well -defined 3D microenvironments . Further , conditions have been identified that enable microfabrication to be performed in the presence of cells - - allowing cell outgrowth and motility to be directed in real time . In addition to the intrinsic chemical functionality of microfabricated protein structures , 3D protein matrices are shown to respond mechanically to changes in the chemical environment , enabling new avenues for micro -scale actuation to be explored . Complex 2D and 3D protein photocrosslinking is further facilitated by integrating transparency and automated reflectance photomasks into the fabrication system . These advances could be transformative in efforts to fabricate precise cellular scaffolding that replicates the morphological (and potentially biochemical ) features of in vivo tissue microenvironments . Finally , these methods are applied to the study of microorganism behavior with single -cell resolution . Microarchitectures are designed that allow the position and motion of motile bacterial to generate directional microfluidic flow - - providing a foundation to develop micro -scale devices powered by cells . |