Synthetic biology used to develop cornea which can self-assemble.
Organ donation is where a live or deceased person consents to having one or more of their organs removed and transplanted to another person. Unfortunately, there’s currently an organ shortage crisis worldwide, and according to the US Department of Health, as of February 2018, there are 115,085 people waiting for life-saving organ transplants in the US. Therefore, much interest has been placed on made-to-order organs, particularly those developed via synthetic biology with the ability to self-assemble. Now, a study from researchers at the University of Newcastle utilises synthetic biology to develop a gel containing live corneal cells which self-assemble to form cornea-like structures. The team state that their new method could be tweaked to produce other human organs, potentially helping millions more people in need of transplants. The study is published in the journal Advanced Functional Material.
Previous studies show that for every person in the world who receives a cornea transplant, there are 69 others who still need one, leaving roughly 12.5 million people with limited sight due to a lack of eye donors. Over the past decade, scientists have been testing artificial corneas made from synthetic collagen gel, however, one of the difficulties is in getting the gel to self-assemble into the curved shape to fit the eye and focus light so the patient can regain their sight. The current study designs a gel mixture to contract by different amounts in different places to adopt a specific corneal shape.
The current study adds live corneal cells to collagen which act like micro-actuators, microscopic engines exerting a contracting pull force to shape a one inch-wide block of tissue into a corneal structure. Results show a circular shape divided into two rings is developed, with peptide amphiphiles located either in the outer ring or in the centre. Data findings show in both cases, one part contracted more than the other and this difference caused the gel to progressively curve over five days until it reached the correct corneal shape.
Results show that the properties of self‐curved gels are more similar to those of the native tissue, and represent a significant improvement over planar 3D scaffolds. The group state that it may be possible to use this technique to manufacture other artificial tissues from organs which normally contain cells that are able to contract, such as heart, skin, muscle and blood vessel tissues. They go on to explain the contracting cells have to be combined with the bio-material of interest, then it is just a matter of understanding which parts have to contract less than others and positioning the peptide amphiphiles within well-defined areas within the bio-material to make it self-assemble into the desired shape.
The team surmise that they have produced an artificial self-assembling corneal-like structure without the use of planar scaffolds. For the future, the researchers state that it may be possible to take this technology one step further to printing more complex biological structures or organs with can arrange themselves without the need of scaffolds to print the cells on, or remove them afterwards.
Source: The Conversation