Stem Cells, Building Blocks for Tissue Engineering

kissimmeemisologistBiotechnology

Dec 14, 2012 (4 years and 6 months ago)

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Life, Death, and


Stem Cell Research

Richard L. Elliott, MD, PhD, FAPA

Director, Medical Ethics

Professor, Internal Medicine

Mercer University School of Medicine

Adjunct Professor

Mercer University School of Law

Goals


Background


Timeline


Principles of medical ethics


Sources and fate of stem cells


Potential therapeutic uses and abuses


Access to results


Ethics and IVF


Preimplantation

Genetic Determination


IVF, RU486, IUDs


Cloning

Recent Timeline


1978 Louise Brown IVF


1996 Dolly the sheep


1998 First human embryonic stem cells


2001 Federal funding for stem cell research limited to
existing stem cell lines


2004 South Korean researchers claim first human
cloned to generate stem cells


2007 Reprogramming of fibroblasts into stem cells


2009 Executive order reversed previous ban on
federal funding for new embryonic stem cell lines

Principles of Medical Ethics


Autonomy


Informed consent of gamete donors, parents
around fate of embryos


Beneficence


Potential therapeutic uses of
hESC

cell research


Non
-
maleficence


Harm to embryos


Social justice


Who will benefit? Will all have access to uses?

Sources of Stem Cells


Existing stem cell lines


Pre
-
2009 18
hESC

lines approved for study using federal
funding


Unused embryos from IVF


2010 43 approved
hESC

lines, 115 submitted for review.
But only one line from pre
-
2009 lines approved thus far


Programmed adult skin cells (
iPSC
)


Umbilical cord blood


Amniotic fluid cells


Bone marrow


Fetal tissue


Somatic cell nuclear transfer

In Vitro Fertilization

IVF


In Vitro Fertilization


Ethical Issues and IVF
-
Derived
hESCs


Weighing harm to embryos
vs

potential
benefits


Informed consent


hESCs

and personhood


Federal funding for
hESC

research

Beneficence and Therapeutic Potential

First FDA
-
approved Clinical Trial Using
hESCs


January 2009


Geron


Spinal cord injury

Autonomy, NIH, Informed Consent, and
hESCs


hESC

derived from IVF for reproductive
purposes


Available alternative uses explained


No payments for embryos


Care provided independent of decision


Should avoid clinician/researcher same


Donors gave voluntary written consent to use
embryos for research

NIH, Informed Consent, and
hESCs


Must provide information on:


Fate of embryos


Embryos may be kept for years


Research not intended as treatment for donor


What personal, potentially identifying information
would be available to researchers


That research might result in financial gain for
researchers, not donors

Non
-
maleficence and The Moral
Status of the Embryo

When Does Life Begin?:

Biological Landmarks


Day 1



Fertilization


Day 4
-
5



Cells used for
hESC


Day 7
-
10


Implantation


Day 14



Primitive streak


Weeks 18
-
20


Quickening


Month 9



Delivery


The Moral Status of the Embryo:

When is the early embryo fully human?


Aristotle and Aquinas: ensoulment with
quickening


Catholic Church through 1591


abortion
before quickening not punishable


1869
-

Pius IX
-

Excommunication for
abortion at any stage of pregnancy


Multiple ethics panels concluded the embryo
is a developing human deserving respect but
not full rights and protections

Faith and Embryonic Stem Cell Research


Harris Poll 2005


70% Americans favor, 19% oppose


70% Catholics, 38% born
-
again Evangelicals favor


57% who oppose abortion favor embryonic stem cell
research


“not in womb, not abortion”


O. Hatch


opposes abortion, favors
hESC

research


Islam
-

no prohibition


Judaism


no prohibition


Hindus


unclear


MUSM research


IVF acceptable across faiths

Embryos and the Law


Georgia Criminal Law:

“unborn child” means a
member of the species homo sapiens at any stage of
development who is carried in the womb.


Roe v. Wade
: "We need not resolve the difficult
question of when life begins. When those trained in
the respective disciplines of medicine, philosophy,
and theology are unable to arrive at any consensus,
the judiciary, at this point in the development of man's
knowledge, is not in a position to speculate as to the
answer.“ May abort up to time of fetal “viability”

Ethics, IVF, and Stem Cells


Does use of
hESCs

from IVF for
procreation restrict research on cells from
the poor?


Is it morally acceptable to use existing
stem cell lines created from embryos?


Should gamete donors and potential
parents have equal rights?


Who should determine fate?


Should Federal funds be used to derive
new
hESC

lines for research?


What to do with leftover embryos?


Over 500,000 embryos
in storage


$100
-
150/year


What if donors don’t pay
for storage?

Access to Stem Cell Benefits


Stem Cell Fraud, Scams
and non
-
FDA Approved
Treatments

Cloned human

Offshore clinics

Non
-
FDA approved


Resources


Elliott_rl@mercer.edu


This presentation


Medicine.mercer.edu


search medical ethics


“resources”


NIH resources on stem cell ethics


http://bioethics.od.nih.gov/stemcell.html


International Society for Stem Cell Research


http://www.isscr.org/public/ethics.htm

Supplemental Slides for Dr. Elliott


More Complete Timeline


1974 Congress bans all federally funded fetal tissue
research


Ethics Advisory Board established to set guidelines for
research on fetal tissue research on tissue derived from
abortions. EAB recommends federally funded research
into IVF


1981 EAB disbanded, effectively ends federal funding into
research on embryonic stem cells


DHHS continues moratorium on federal funding despite
18
-
3 recommendation for federal funding by b Human
Fetal Tissue Transplantation Research Panel


1993 Moratorium on federal funding lifted


1994 Moratorium reinstated

Preimplantation Genetic Testing


Sex selection


Genetic “defects”


Physical characteristics

Stem Cells and PEDs


Should results from stem cell research
be used to enhance performance?


Human Growth hormone


Anabolic steroids


EPO

IVF, RU486, IUDs


RU486 as an emergency contraceptive
and IUDs prevent implantation


Contraception
vs

abortion in preventing
implantation


Compare unused (non
-
implanted)
embryos from IVF with RU486 and IUDs
ethically

Terminology


IVF


Embryonic stem cells


Totipotency
,
pluripotency


Cloning

Cloning

Somatic Cell Nuclear transfer

Somatic Cell Nuclear Transfer


Generate stem cells with defective gene for
research on disease, e.g., Parkinson’s


Use patient’s cells to generate stem cells to
create tissue for transplantation that has
similar immunological characteristics as
patient


Hybrids


Human cloning

Induced
Pluripotent

Stem cells

What are areas of ethical concern?


Source and fate of stem cells


Potential therapeutic uses and abuses


Access to results


Ethics and IVF


Preimplantation Genetic Determination


IVF, RU486, IUDs


Cloning


NIH Guidelines for Stem Cell Lines


Pre
-
2009 18
hESC

lines approved for
study using federal funding


2010 43 approved
hESC

lines, 115
submitted for review. But only one line
from pre
-
2009 lines approved thus far