Growing body parts for sale

By Michael Ogembo Kachieng’a

Tissue engineering research is fundamentally a collaborative endeavour between biomedical engineers and doctors.

Medicine is a lonely business. It is a business of the sick. I have always admired doctors from a distance. Working at the borderline of cutting-edge issues like life and death every hour, every day, every month and every year is pretty taxing.

Sometimes I pity them. Why would a normal healthy person spend the best part of his / her life attending the sick?

Maybe doctors have a divine mission to serve and save humanity. I have no competency to question the divine wisdom. Profession is all about choice.

When you inject engineering into medicine, the resulting professional endeavour becomes intellectually exciting and magical. The marriage of engineering and medicine gives birth to valuable siblings like tissue engineering and genetic engineering among others. These two professions meld into a unity.

Merely researching specialised sciences is barely interesting at best and boring at worst. The real excitement comes when actively working at the interfaces of sciences.

It is like a person with a multi-personality disorder — hard to understand and difficult to predict — thus, a source of excitement and deeper professional satisfaction with no set ideas of what to expect next. You are continually in intellectual suspense when working at the scientific interfaces.

Biomedical engineering has made great progress in the understanding of how cells grow into functioning tissue and what chemical cues they need to do so correctly. Tissue engineering is the application of that knowledge to the building or repairing of organs, including skin, the largest organ in the body. Generally, engineered tissue is a combination of living cells with a support structure called a scaffold.

The scaffold, depending on the organ in production, can be anything from a matrix of collagen, a structural protein, to synthetic bio-gradable plastic laced with chemicals that stimulate cell growth and multiplication. The ‘seed’ cells that initiate this propagation come from either laboratory cultures or from the patient’s body.

The problem with synthetic organ tissues is that they wear out. It is therefore better to design a synthetic structure that the body recognises as its own and can slowly remodel and replace with its own structure. For starters, tissue engineering is an amazing and exciting scientific endeavour. It is magical to engineer human skin for burn victims.

Synthetic skin seems like a ‘can’t miss technology’. Every year, several million people develop skin ulcers that cannot be cured by conventional dressings and bandages.

Graft skin

Yet, most of these ulcers can be healed completely by using engineered tissue — like a patch on your car tire. For extensive burns, doctors typically graft skin taken from cadavers. But after a few weeks, the patient’s body usually rejects the graft, so additional medical applications are needed to cover the wounds and prevent infections before the patient’s own tissue starts to regenerate.

In contrast, synthetic skin is not rejected because it is grown from versatile cells that do not trigger a strong immune system response.

The Holy Grail of the tissue engineering business may reside in the cartilage. There are many types of cartilage defects that need to be treated.

They range from trauma in motor vehicle accidents, to chronic diseases such as arthritis, in which cartilage is lost due to biochemical and biomechanical changes in the joints.

In Kenya, the candidates for cartilage business include marathon runners, footballers, the nyama choma elite (roast meat eaters), overweight beauties and indeed any adult over 45 years.

Amongst body joints, the knee is one of the largest. The knee has become the centre of focus in tissue engineering because of the strategic role played by the cartilage in it’s biomechanics.

Harvesting organs

One of the challenges researchers are facing is that the cartilage grows very slowly, without a large amount of supporting matrix.

But recently many laboratories have been experimenting with harvesting a patient’s own cartilage, growing it more quickly ‘in vitro’ , then transplanting it at some later stage into the original to body.

With modern developments in technological innovations, biology and biochemistry, the broadened research on tissue engineering has expanded to cover the development of support equipment for paraplegics such as synthetic ligaments.

Tissue engineering

The scientific effort to marry neurons and microelectronics into hybrid circuits is still at its infancy — but the interface holds the key to a magical world of manufacturing biological body parts.

Tissue engineering has made great strides as a science. It has been less successful as a business. Although there is high market potential, many companies in the business of manufacturing body parts are struggling with the entrepreneurial financing of their operations.

High-tech business history has taught us that start-ups based on novel technologies challenging the industrial status quo — such as tissue engineering have always had funding problems at the initial stages.

The tissue engineering business is no exception. Tissue engineering has the potential of revolutionising both clinical and health care services.

—The writer is a Biomedical Engineering Scientist, Consulting Technological Entrepreneur and Professor of Technological Entrepreneurship at the Graduate School of Technology Management, University of Pretoria, South Africa.