Tissue engineering (TE) is an emerging field for tissue repair and regeneration compared to conventional techniques including autograft and allograft, through engineering functional implants created from living cells. TE is a highly interdisciplinary research area where material science, engineering, and biology are blended to achieve tissue regeneration. Efforts have been made to regenerate liver, skin, bone, and vascular tissues by applying a tissue engineering approach. To generate any type of tissue in a laboratory environment, scientists need to mimic the cellular microenvironment by offering structural, chemical, physical, and biological cues to the cells. Introduction of these cues to the cellular environment starts with manufacturing a supportive matrix called a scaffold.

Novel technologies such as solid freeform fabrication has enabled the bioprinting of reproducible, patterned, cellembedded tissue constructs that simulate the in vivo 3D microenvironment for the creation of high-fidelity physiological tissue models. Advancements in extracellular matrix material progresses biomodeling and scaffold design via environmental cues, essential macromolecules, and improved cell attachment. Some promising biomaterials, including matrigel and collagen, express unique thermal properties. The primary challenge to bioprinting these materials at room temperature is that they naturally gel by molecular self-assembly upon thermal cross-linking when ambient temperatures increase above an ≈4 °C threshold.

In this work, a motion- and temperature- controlled bioprinting system is conceptualized for cell-laden tissue fabrication. A cooling chamber has been designed and implemented to enable automated, temperature-controlled bioprinting of a 3D micro-organ. This method allows the matrigel and cell to be printed in a temperature-controlled environment, allows the cell/matrigel compound to form 3D tissue constructs with designed patterns and internal architectures, and applies the 3D matrigel tissue constructs as tissue or micro-organ models for biology, tissue engineering, and drug study.

This work was done by Wei Sun, Jessica Snyder, and Robert Change of Drexel University for Johnson Space Center. MSC-25471-1

NASA Tech Briefs Magazine

This article first appeared in the February, 2016 issue of NASA Tech Briefs Magazine.

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