Much like human blood, human tissue — including bone, skin, heart valves and corneas — is used in surgical applications to treat patients for a variety of conditions including severe burns, torn tendons and ligaments, and to repair musculoskeletal structure such as teeth, skin and spinal components.
And just like human blood there is no synthetic alternative that matches the power of real human tissue.
But the possibilities for engineered tissue are growing by the day and are showing immense promise.
To understand why tissue engineering is an increasingly important focus area for the biomedical sector, it is useful to unpack the need for human tissue among patients in South Africa.
At any given time, about 2 780 South Africans are in need of an organ to save, or dramatically improve, their quality of life.
The demand for human tissue for transplantation means that this number may increase to about 5 000 persons relying on donors for these lifesaving anatomic materials and organs.
Factors driving the human tissue transplantation market include an increase in the incidence of acute diseases, the introduction of highly sophisticated tissue products and an increase in the number of tissue banks, according to this research.
Yet, tissue and organ donation does not readily happen in South Africa. According to the latest figures, only 1.4 per million South Africans are registered organ donors. And while this number may be down to a number of factors, including a lack of awareness and understanding, cultural stigma and even apathy, an increase in the number of registered donors is not the only way to address this issue.
Engineering a new medical future
Tissue engineering is one of the most dynamic biomedical disciplines and has enormous potential to positively affect the lives of countless patients by assembling functional constructs that restore, maintain or improve damaged tissues or whole organs, as per the National Institutes of Health definition.
In fact, one of the key advantages of tissue engineering is its ability to regenerate a patient’s own tissue and organs, which eliminates the issue of biocompatibility.
In South Africa, where the chronic disease burden costs the economy millions each year, tissue engineering has the potential to offer an integrated solution that eases the pressure on the healthcare sector and ultimately ensures better patient outcomes.
But tissue engineering is not free of ethical challenges and it is crucial that these questions and concerns are identified at an early stage. Not only is it part of science’s responsibility towards society, but is in the best interest of the field itself.
The need for ethico-legal oversight is driven by the obligation scientists, researchers, engineers and healthcare professionals have to protect patients, manage medical risks and safety issues, and comply with the minimal legal, ethical, scientific and medical standards set in various regions and jurisdictions.
In the South African context, both research and anecdotal findings point to the need for ethico-legal requirements that address concerns.
Some of the most controversial ethico-legal challenges regarding tissue transplantation are:
Because some tissue products may require the use of embryonic stem cells, moral objections may arise, as it can require that embryonic stem cells be sourced by means of the destruction of a five to seven-week-old embryo.
In order to develop genetically identical or compatible tissue for transplantation, it may be necessary to rely on a process known as somatic cell nuclear transfer, which not only requires the use of human embryonic stem cells, but is controversial because it constitutes a form of human cloning.
The proliferation of the cells required in some tissue products poses challenging intellectual property questions relating to the patenting of living things, including the right of the donors of the cells to co-own or benefit from the sale of products developed using their cells or tissues.
The nature of very advanced tissue engineered products makes it difficult to determine appropriate regulatory frameworks for them, especially those that are not developed for widespread use, as is the case with ordinary pharmaceutical products. Regenerative medicine, which includes tissue-based or tissue-engineered products, is not regulated in South African law. Clarity is required as to whether tissue-engineered products should be regulated as biological medicines, medical devices, cell-based products or possibly even gene therapy.
It would be remiss to not acknowledge that tissue engineering as a vehicle for supplying medical products to South Africa and other low- and middle-income countries is still very much in its infancy.
Having said that, Vitanova, the country’s latest and most state-of-the-art tissue engineering facility, is doing a great job at fulfilling a need for allograph bone and tissue in the country, while the science and ethics around tissue engineering matures and catches up.
It is only with appropriate guidelines and a robust legal framework in place that tissue engineering will reach its potential and measurably improve the quality of life of those patients who would otherwise have no option but to wait for a tissue or organ voluntarily donated.