Regenerative Medicine May Overcome Existing Hurdles with New Blood Vessel Method

A hurdle to effective transplantation of organs and tissues developed in laboratory is the inability to build a viable network of blood vessels that incorporates the new tissue into the individual. Now, a new way of developing blood vessels that makes use of patient derived 3-D scaffolds – as opposed to artificial ones – could fulfill this need and provide a major boost to regenerative medicine.

The investigators identified that the laboratory-generated blood vessels (in green) were capable to make new connections with sprouts protruding from the rat aorta tissue (in red). Image credit: Tiago Fortunato/University of Bath
The investigators identified that the laboratory-generated blood vessels (in green) were capable to make new connections with sprouts protruding from the rat aorta tissue (in red). Image credit: Tiago Fortunato/University of Bath

Investigators from the University of Bath and the Bristol Heart Institute published their new approach for developing 3-D blood vessels in the journal Scientific Reports.

They recommend because their approach of developing blood vessels in a 3-D scaffold uses cells from the patient, it decreases the risk of transplant denial.

The concept of regenerative medicine is to substitute impaired organs and tissues in sufferers with new ones. Preferably, these must be produced using material produced from the patient, so as to decrease the possibility of rejection by the immune system.

A best application of such tissue engineering is heart failure, where the heart is unable to pump sufficient blood all over the body due to  the heart muscle has turn into weak or stiff. In theory, new heart muscle engineered in the laboratory could be transplanted to substitute the worn out tissue in the sufferer.

However, in reality, regenerative medicine is placed back due to  issues with producing a blood supply to the new tissue.

Research team leader Dr. Giordano Pula describes:

“A main obstacle in tissue engineering and regenerative medicine is offering the new tissue with a network of blood vessels, and connecting this to the individual’s present blood supply; this is important for the tissue’s survival and incorporation with adjacent tissues.”

New network of blood vessels set up in 3 days

Professor Peter Weissberg, one of the study’s sponsors and Medical Director of the British Heart Foundation says that:

If the approach is confirmed to be effective in additional studies of its possible applications, it could help enhance the lives of the many individuals who are having difficulties to live with heart failure.

Previous attempts to generate a 3-D network of blood vessels using human cells and synthetic scaffolds have not been very successful.

The new approach depends on two components: human platelet lysate gel and endothelial progenitor cells (EPCs) – a kind of cell that allows maintain blood vessel walls.

Both the gel and the EPCs can be isolated from the sufferer’s blood. In their research, the investigators show how these can produce a network of small blood vessels.

They compared the new approach’s capability to develop new blood vessels within the aorta tissue of rats in opposition to other approaches that use collagen or fibrin gels.

The outcomes present that over a 3 day time, the EPCs had set up a new network of blood vessels within the human platelet lysate gel. This contrasted with “negligible development of an inter-connected capillary network inside collagen I or fibrin gels.”

Co-author Dr. Paul De Bank, states that due to the human platelet lysate gel consists of a number of various growth factors, this influences present blood vessels to infiltrate the gel and form new connections with the new vessels. Adding to above statement he says:

“Incorporating tissue-specific cells with this EPC-containing gel provides the possibilities for the development of fully vascularised, functional tissues or organs, which incorporate seamlessly with the patient.”

The investigators note that one more advantage of their approach is that because the gel comes from human platelets, it must be safer than gel extracted from animal products.