Abstract
Purpose: :
Bioengineered tissues manufactured from stem cells admixed with or applied to a substrate or scaffold betoken revolutionary changes to regenerative medicine, but little attention has been paid to the development of global standards for minimizing health risks associated with their use. Ocular surface tissue serves as a bellwether for other tissues and organs in the field.
Methods: :
All clinical trials using bioengineered tissue for the ocular surface published between July 1st 1996 and June 30th 2005 were reviewed with attention to materials used and statements of risk assessment, risk remediation, adverse events, ethics approval and regulatory oversight.
Results: :
Ninety–five percent of investigational protocols used one or more animal–derived products and an overlapping 95% utilized one or more donor human tissues. Consideration of risks reveals a very low probability of potential harm, but significant risk of disability or death if such an event were to occur. Risks included xenogenic microchimerism, xenoantigenicity, viral or prion contamination, xenozoonosis, cell fusion, and tumorigenesis Adverse events were largely restricted to reports of post–operative infection. Details of ethics approval, patient consent, and donor serology were not consistently provided. No references were made to risk assessment and remediation or to codes of manufacturing and clinical practice.
Conclusions: :
While a degree of risk is associated with components used in the manufacture of ocular surface tissue grafts, investigational reports of this new technology have yet to address issues of risk management and regulatory oversight. Attention to risk and codes of manufacturing and clinical practice will however be required for advancement of the technology and we suggest the adoption of international standards to address these issues through an international regulatory agency or document such as the International Conference on Harmonization or the Declaration of Helsinki.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • cornea: clinical science • cornea: epithelium