Stem cells from umbilical cord blood may help build new heart valves



Rare injuries accounted for 3.5 percent of high school athletes’ injuries 2005 through 2007, according to the first study to examine rare injuries and conditions of U.S. high school athletes. Rare injuries include eye injuries, dental injuries, neck and cervical injuries and dehydration and heat illness, which may result in high morbidity, costly surgeries and

Full Post: Study looks at rare injuries in high school athletes

Children with heart defects may someday receive perfectly-matched new heart valves built using stem cells from their umbilical cord blood, according to research presented at the American Heart Association’s Scientific Sessions 2008.

When infants are born with malfunctioning heart valves that can’t be surgically repaired, they rely on replacements from animal tissue, compatible human organ donations or artificial materials. These replacements are lifesaving, but don’t grow and change shape as a child develops; so two or more surgeries may be needed to replace outgrown valves. The animal tissue may also stiffen over time as well and be less durable than a normal human valve. With artificial valves, children also must be treated with blood thinners.

“In our concept, if prenatal testing shows a heart defect, you could collect blood from the umbilical cord at birth, harvest the stem cells, and fabricate a heart valve that is ready when the baby needs it,” said Ralf Sodian, M.D., lead author of the study and a cardiac surgeon at the University Hospital of Munich.

The tissue engineering of heart valves is still in its infancy, with various researchers investigating the possibility of using cells from blood, bone marrow or amniotic fluid.

In the study, the research team used stem cells (CD133+ cells) derived from umbilical cord blood. The cord blood was frozen to preserve it. After 12 weeks, the cells were seeded onto eight heart valve scaffolds constructed of a biodegradable material and then grown in a laboratory.

Afterwards, examination using electron microscopes revealed that the cells had grown into pores of the scaffolding and formed a tissue layer. Biochemical examination indicated that the cells had not only survived and grown, but had produced important elements of the “extracellular matrix,” the portion of body tissue that functions outside of cells and is essential to tissue function and structure. Compared with human tissue from pulmonary heart valves, the tissue-engineered valves formed:

  • 77.9 percent as much collagen (the main protein in connective tissue);
  • 85 percent as much glycosaminoglycan, a carbohydrate important in connective tissue); and
  • 67 percent as much elastin (a protein in connective tissue)

Furthermore, using antibodies to detect various proteins, the researchers found the valves contained desmin (a protein in muscle cells), laminin (a protein in all internal organs), alpha-actin (a protein that helps muscle cells contract) and CD31, VWF and VE-cadherin (components of blood vessel linings).

“These markers all indicate that human cardiovascular tissue was grown in the lab,” Sodian said.

Several important questions remain to be solved regarding tissue-engineered functional heart valves, including identifying the optimal scaffold material and learning how to condition the valves in the laboratory so they work properly after being implanted, Sodian said.

“Tissue engineering provides the prospect of an ideal heart valve substitute that lasts throughout the patient’s lifetime and has the potential to grow with the recipient and to change shape as needed,” he said.

http://www.americanheart.org/

Link




Taking blood stem cells collected from an umbilical cord into the lab and expanding their number before transplanting them to replace a patient’s blood supply is as safe as a standard cord blood transplant, researchers reported at the 50th Annual Meeting of the American Society of Hematology. In a first-of-its-kind randomized clinical trial, researchers at

Full Post: Trial shows safety of pre-transplant expansion of umbilical cord blood stem cells



An innovative approach for implanting a new aortic heart valve without open-heart surgery is being offered to patients at NewYork-Presbyterian Hospital/Columbia University Medical Center. Known as the PARTNER (Placement of AoRTic traNscathetER valves) trial, this Phase 3 multicenter study is being led by national co-principal investigators Dr. Martin Leon and Dr. Craig Smith and is

Full Post: New method for implanting aortic heart valves



A new study suggests that adult bone marrow stem cells can be used in the construction of artificial skin. The findings mark an advancement in wound healing and may be used to pioneer a method of organ reconstruction. The study is published in Artificial Organs , official journal of the International Federation for Artificial Organs

Full Post: Bone marrow stem cells used to regenerate skin



Today at the annual scientific sessions of the American Heart Association, the first U.S. clinical trial data on the Melody transcatheter pulmonary valve were presented. These findings also represent the first U.S. data on transcatheter valves in a population with congenital heart disease and the first reported U.S. data on the use of a transcatheter

Full Post: Medtronic announces U.S. trial data on transcatheter valve for congenital heart disease



Researchers at Children’s Hospital of Pittsburgh of UPMC have been able to effectively repair damaged heart muscle in an animal model using a novel population of stem cells they discovered that is derived from human skeletal muscle tissue. The research team - led by Johnny Huard, PhD - transplanted stem cells purified from human muscle-derived

Full Post: Researchers repair injured heart muscle with novel stem cells