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As biotechnology evolves, the quest to develop more advanced materials that closely mimic the human biological architecture while being readily accepted into the body has gained considerable momentum.  In particular, the field of microfluidics (designing systems that will handle fluid in a tiny – less than 1mm space) has grown, bringing us the inkjet, DNA chips, and more.  For the design to be effective, two essential goals must be met – (1) The structure must similar enough to carry out all functions of a vascular system (serve as intact passageway for blood flow and diffusion) and (2) Cells must be able to live and flourish within the channels (it must be biocompatible), so as to ensure the body does not reject the device.

Most protocols designed to achieve this thus far utilize methods borrowed from the semiconductor industry that establish a rigidly calculated structure according to absolute blueprints – very much resembling the fabrication of circuit boards.  These channels are etched onto a flat surface and have to be stacked to achieve a three-dimensional architecture.  However, this stacking is too difficult for research purposes, which don’t have the luxury of specially designed large-scale production equipment.  And so, another method is needed to assemble substantially thick 3D networks that simulate biological conditions.  What’s more, the vascular system of the human body is not in fact, rigidly engineered, but rather varies from individual to individual in terms of connectivity and dimensions.  Accordingly, to accommodate Nature’s broad range of solutions to life’s problems, we needed to make a randomized network.

We have proposed a simple yet clever solution to the problem – use a cotton candy machine to spin a 3D network of fibers, embed the fibers in a biocompatible material such as gelatin, and dissolve away the fibers to generate the network of microtubules!  In order for the procedure to work, the material used to spin fibers from must be dissolvable under conditions that do not destroy the gelatin framework in which it is embedded – that is, no extreme temperatures, low pressures, or toxic organic solvents can be used in the process.  For this purpose, shellac was selected, which can be “cotton-candified,” embedded in a gelatin slab, and subsequently removed with a mildly basic bath.

While we have furthered the optimization process along, much work still needs to be done in order to ensure continuous cell survival.  People building on our work may select different materials and apply different degrees of treatment to these materials so as to assimilate to the natural biological system and effectively heal damaged vascular systems.

In summary, there are two primary take home points from this project that should give pause to both scientists and non-scientists alike: (1) The problem of designing advanced biomaterials may actually be achieved through technologies one would least expect to be used for scientific purposes – such as a cotton candy machine, and (2) When it comes to biological systems, a randomized process may in fact be more viable and reliably received as opposed a rigidly engineered structure.  After all, quantum mechanics and sociology both seem to be finding that a statistical distribution is the most accurate description of reality we can articulate, so it only makes sense to incorporate this distribution into the biomaterials we are engineering – as long as care is taken to make sure that the proper parameters are kept rigidly determined and the proper parameters are left open to statistical randomization.

The full paper can be accessed here:

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