Three-dimensional printing of blanks for blood vessels

Template for vessels printed by 3D printer

NanoNewsNet based on BWH materials: Building a Better Blood VesselCreating artificial blood vessels from scratch that could deliver nutrients, remove hazardous waste and thereby ensure the life of tissues and organs, as it happens in a living organism, remains a very difficult task for scientists.

However, using the technology of three-dimensional (3D) bioprinting, researchers from Brigham and Women's Hospital (BWH) managed to achieve some progress in this area.

"Engineers have made incredible progress in creating complex artificial tissues, such as heart, liver and lung tissues," says the head of the study, biomedical engineer Ali Khademhosseini, PhD, director of the Biomaterials Innovation Research Center (Biomaterials Innovation Research Center) BWH. "However, the creation of artificial blood vessels remains the most important problem of tissue engineering. We tried to solve it by proposing a unique strategy for the vascularization of hydrogel structures, combining advances in 3D bioprinting technology and in the development of biomaterials."

First, to create a matrix of agarose fibers (a natural polysaccharide), which was to serve as a template for future blood vessels, the researchers used a 3D bioprinter. After printing the template on a printer, they coated it with a precursor substance of hydrogel. Then this substance was subjected to cross-stitching, and the template inside it was removed.

Using hydrogel designs, Brigham Women's Hospital Scientists
we have created extensive networks of artificial blood vessels.
(Photo: Bertassoni et al., Lab On A Chip)

"Our approach involves printing agarose fibers that become channels of blood vessels. But its uniqueness lies in the fact that these fiber templates printed by us are strong enough so that they can be physically removed and channels obtained," comments Dr. Khademhosseini. "This eliminates the need to dissolve the template layers, which may not be good for the cells in the gel surrounding them."

Dr. Khademhosseini and his colleagues managed to obtain networks of microchannels demonstrating various structural characteristics, as well as successfully embed these functional and blood-permeable microchannels into a wide range of commonly used hydrogels, for example, based on methacrylated gelatin or polyethylene glycol in various concentrations.

In particular, methacrylated gelatin loaded with cells was used to show how newly developed vascular networks increase cell viability and improve their differentiation. In addition, the formation of an endothelial monolayer was successfully achieved in the obtained channels.

"In the future, 3D printing technology can be used to develop tissues for transplantation adapted to the individual needs of the patient, or tissues used outside the body to create safe and effective medicines," concludes Khademhosseini.

Article by Bertassoni et al. Hydrogel bioprinted microchannel networks for vascularization of tissue engineering constructs is published in the journal Lab On A Chip.

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