Human tissue engineered products—drugs or devices?

Editor- I read your recent editorial on human tissue engineered
products--drugs or devices with great interest.1 As in the past, regulation
always lags behind scientific development. We all welcome the new
guidelines produced by the Medical Devices Agency on the use of human
derived therapeutic products. In ophthalmology, the use of autologous or
allogenic corneal limbal stem cell for ocular surface reconstruction is
now widely established.2,3 Yet no regulation in controlling its use has
been established until now. It is hard to imagine that developing the use
of cell-based therapy is much easier that developing a new medical device
or a new drug. In ex-vivo corneal stem cell expansion, the cells are grown
in media containing various growth factors and co-culture with transformed
mouse fibroblast cell before transplantation onto corneas with stem cell
deficiency.

Clearly, there is a need for accreditation of laboratories
conducting such work. The use of ancillary products must be addressed and
the use of co-culture system must be in consultation with United Kingdom
Xenotransplantation Interim Regulatory Authority. Without such stringency,
there will be a risk of cross-animal contamination such as the one we
witness recently in outbreaks of SARS virus.

1. Faulkner A, Geesink I, Kent J, FitzPatrick D. Human tissue
engineered products-grugs or devices? BMJ 2003;326:1159-1160

2. Pellegrini G, et al. Long-term restoration of damaged corneal surfaces
with autologous cultivated corneal epithelium. The Lancet 1997;349:990-3

3. Tsai RJF, Li LM, Chen JK. Reconstruction of damaged corneas by
transplantation of autologous limbal epithelial cells. NEJM 2000;343(2):87
-93

Competing interests:  
None declared