The fridge?The TV?The Wii?

Without Indoor plumbing , modern society would be set back 250 years.

Until recently, tissue engineers have been unable to provide plumbing for fabricated tissues.

This has greatly hindered advancement in terms of creating larger and more complex tissues and organs.↑ This is real

people! ↑

Urethra grown in vitro

Mammalian cells utilize capillary networks for the delivery of nutrients and the removal of waste

Capillary networks are arranged so that the cells which they nourish are located within 100 – 200 µm

Absence of vascular network has limited thickness of clinically used engineered tissues to mm scale at most

Failure to provide nutrient supply frequently results in loss of more than 95% of transplanted cells

Dr. Jason SpectorLeon Bellan

After giving a university lecture Dr. Jason Spector was approached by a student working with microfibers

Leon Bellan noted that the dimensions and general form of cotton candy mimics capillaries

Vascular microchannels were made with store bought sugar and a modified cotton candy machine

Step 1: Pour molten sugar to form thin stems. Let cool.

Step 2: Make cotton candy.

Step 3: Stick sugar stems into cotton candy.

Step 4: Incubate for 2 minutes to fuse sugar structure.

Step 5: Submerge in biocompatible epoxy. Let cure.

Step 6: Use ethanol to dissolve sugar. Rum should do.

Step 7: Fill with blood. Enjoy.

electron microscopy

multiphoton spectroscopy

Frames from video of flourescent polystyrene particle flow.

Red blood cells in vitro

Red blood cells in epoxy

Final Product: physiologically functional microvascular network in biocompatible PDMS cast.

The ability to construct microvascular networks is a major hurdle passed on the road to engineering complex organs.

REFERENCES

[1] URI BME 281 BME Seminar II <www.ele.uri.edu/courses/bme281>.

[2] Ikada, Yoshito. Tissue Engineering: Fundamentals and Applications. Kidlington, Oxfordshire: Elsevier Inc, 2006, pgs 63-64

[3] Leon M. Bellan, Sunil P. Singh, Peter W. Henderson, Teresa J. Porri, Harold G. Craighead, Jason A. Spector. "Fabrication of an artificial 3-dimensional vascular network using sacrificial sugar structures." Soft Matter, 2009: pgs 1354-1357.

[4] Jason W. Nichol, Ali Khademhosseini. "Modular tissue engineering: engineering biological tissue from the bottom up." Soft Matter, 2009: pgs 1312-1319.

[5] “Making Capillaries from Cotton Candy.” Dean of Invention, Planet Green, 2011. Television