Biomedical Engineering Reference
In-Depth Information
That stem cells are supposed to be better the younger they are may result
from a complex phenomenon involving the telomere structure ± a region of
DNA at the end of a chromosome that protects the start of the genetic coding
sequence against shortening during successive replications. As the cell divides, a
series of these structural components is lost until it is completely absent: the cell
can then no longer divide and apoptosis follows. This, by some interesting
meanings, could be also referred to as the biological clock.
37
`This is all new biology, which could have an unlimited potential,' said Dr
Paul Sanberg, director of the University of Southern Florida's center for aging
and brain repair. `Cord blood research is moving us into an era of regenerative
medicine where we're going to be approaching chronic degenerative diseases
with ways to repair them by generating new tissues.'
From benchtop to bedside, in a logical sequence, what is expected is that
validated autologous cell therapy procedures alone or in combination with
biomaterials become the first medical routine in regenerative medicine and
TCEt. Then the road might diverge: one way to the off-the-shelf autologous and
allogeneic cell, the other to allograft and tissue substitutes of synthetic or natural
derivation. These different approaches will meet and connect to what shall path
the future of TCEt, the combination therapy. Before being included as routine
protocols in hospitals, TCEt will have to navigate the critical path of a new
product or medical device under regulatory agencies worldwide (FDA, EC,
ANVISA, and so on), as any other innovative technology in patient care.
As to cell therapy using autologous cells, there is no need to go through the
long period required for approval of new drugs. Although regulatory agencies
are issuing propositions to this matter, there are no formal regulations in this
field. Still, although some declare that the only requirement for autologous cell
treatments after a minimal ex vivo manipulation is to follow `good laboratory
procedures', that cannot be the rule. Standardized protocols must be searched
and regulatory agencies will certainly realize that whatever cell manipulation
there is, if one is meant to use it routinely, there has to be a safe, validated
protocol. That is, in summary, each cell collection has to be seen and treated as
if it were a pharmaceutical production lot. With all the quality control and
quality assurance data, proceedings, etc. And when cells are more extensively
manipulated in vitro, or when exogenous materials are used, standardized
protocols, risk assessment, quality controls should be emphasized.
Unlike biotechnology, molecular biology and genomics, which already have
a historical background of several decades, the organization and growth of tissue
engineering and cell therapy industry is yet to be established. Synthetic materials
would be the most interesting basis of tissue replacement products, but there are
no synthetic materials that are totally accepted by and integrated into the body.
Whatever synthetic structure that is implanted into the body will be encapsulated
by the body's immune system and gradually lose effectiveness.
38
Search WWH ::
Custom Search