Bioprinting is a revolutionary technology for the tissue engineering field with promises to permit the rapid fabrication of tissues and organs. However, not all tissues are created equal in the eyes of a bioprinter. While all tissues and organs may eventually be bioprinted, there are several tissues that have characteristics that allow them to be more easily bioprinted right now and are on their way to clinical application.
- Skin is the body’s largest organ. Its structure is also striated and it possesses significant natural healing capacity. Both these factors make skin attractive as a bioprinting target. The use of a bioprinter to deposit distinct layers consisting of specialized bioinks to regenerate the epidermis, dermis, and subcutaneous layers of the skin is a promising blueprint for the mass production of graftable skin. Bioprinting can also be utilized to deliver the necessary cell types concurrently with bioink deposition. Furthermore, highly specialized bioink/cell mixtures can be deposited in specific regions of the construct for the regeneration of skin microstructure such as hair follicles. Treatment for baldness anyone?
- The cornea is a critical component of the eye by controlling and focusing the entry of light into the eye. While the tissue has a minor regenerative capacity, in severe injury the cornea can scar. This scarring can impair vision and be detrimental to quality of life. Like the skin, the cornea possesses a striated structure suitable for recapitulation through bioprinting! Deposition of specialized bioinks that can regenerate the epithelium, stroma, and endothelium to create a new cornea is an exciting option enabled by bioprinting!
- Staying within the eye, the retina has grown great attention in the bioprinting field. However, unlike the cornea, the retina possesses upwards of 10 layers and the unique challenge of integrating with the optical nerve. Great progress has been made in recent years, with researchers at Cambridge successfully printing retinal cells (http://www.cam.ac.uk/research/news/cells-from-the-eye-are-inkjet-printed-for-the-first-time). The success of a printed retina is dependent on its ability to integrate with the optical nerve. Fortunately, bioprinting has drawn great interest in the engineering of nerves.
- Building on the previous retinal tissue, bioprinting technology has been applied to the engineering of conduits to augment the healing of damaged and severed nerves. Bioprinting is a valuable tool is not only the fabrication of these hollow conduits but also the generation of gradient materials within the conduit that can guide regeneration (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4765385/). These gradients of cues such as biochemical factors, growth factors, and morphogens are essentially to direct the regeneration of the nerve. Bioprinting greatly simplifies the process of fabricating these gradients and permits the incorporation of more complicated gradients due to significantly better control over the fabrication process. Furthermore, the advances in the bioprinting of one tissue can be applied to the bioprinting of another tissue! Exciting!
- Finally we arrive at everyone’s favorite and least favorite tissue of the body, your teeth. Everyone loves them when you want to eat some cake, but hates them when you have to suffer the consequences of that sweet tooth at the dentist. Well you can thank researchers in Australia for solving this issue, who have utilized a bioprinter to print new teeth! (https://cosmosmagazine.com/technology/saving-your-teeth-latest-3d-bio-printing-breakthrough) Currently, the approach is in clinical trials and may only be two years away from practice. Stay tuned! You may be able to eat all the cake you want and only have to worry about maintaining your gym routine due to bioprinting technology!