Keeping Abreast (or two) of Regenerative Medicine

Regenerative medicine is based upon thebody's ability to build itself -- and to often re-build itself after injury.  We are seeing breakthroughs in stem cell technologies virtually every week.  New technologies that allow physicians to use a patient's own cells to re-build a lost or damaged body part will avoid problems with immune rejection and ethical objections.  And if the touchstone for the explosion of regenerative medicine happens to be the human breast -- who can complain?

How to Build a New Breast

Cytori’s process for reconstructing or augmenting breasts relies on the recent discovery that human fat contains an amazing concentration of stem cells—cells that can be separated out using a centrifuge. That’s the science part. The artistry comes in when the surgeon makes tiny incisions for depositing the enriched fat cells, building a breast one dot-sized injection at a time like a 3-D pointillist. Here’s how it works.

Step 1 Liposuction

Breast reconstruction usually starts in the abdomen, using liposuction to harvest fat cells. Each liposuction syringe holds about 60 cc (2 fluid ounces) of fat cells and takes five minutes to fill. Repairing the divot caused by an average lumpectomy requires eight to 10 syringes to get about 360 cc of fat tissue. Half the fat is used to create the volume needed to fill the divot and half is processed to isolate stem and regenerative cells. A typical augmentation requires 800 cc (27 ounces) of liposuctioned fat: Volume varies, but in one study 160 cc of injected stem-cell-enriched tissue boosted breast circumference an average of 4 centimeters (1.6 cup sizes).

Step 2 Centrifugation

The liposuctioned fat is injected into the Celution System. ›› The fat cells are then “washed” with proprietary enzymes that break down the scaffolding that holds the fat cells together. ›› Next, a centrifuge separates the fat cells from the stem and regenerative cells, concentrating them into a pellet, which is then extracted. ›› The pellet of cells is added back to some of the liposuctioned fat cells, producing a liquid suspension enriched with stem and regenerative cells and ready for injection.

Step 3 Injection

Using a tool called the Celbrush, the surgeon repeatedly deposits the enriched cells in the breast, either at the site of a lumpectomy or throughout the breast for augmentation or repair of a mastectomy.

With reconstruction patients, the tip on the brush makes tiny cuts that perforate scarred areas, transforming the bed of damaged tissue into a biological mesh. The Celbrush releases 0.5 cc of cell-enriched tissue each time the surgeon moves its control wheel. The process typically takes a couple of hours, depending on the extent of treatment. The deposited tissue bonds quickly to the existing tissue. Within 48 hours, new capillaries and blood vessels entwine through the new cells, supplying oxygen and nutrients to the now-stable tissue. ›› The injection area isn’t painful afterward; patients go home the same day.

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More from Brian Wang

New RiPS Stem Cells May Become Therapeutic Breakthrough

Scientists have invented an efficient way to produce apparently safe alternatives to human embryonic stem cells without destroying embryos, a long-sought step toward bypassing the moral morass surrounding one of the most promising fields in medicine.

A team of researchers at the Harvard Stem Cell Institute in Boston published a series of experiments Thursday showing that synthetic biological signals can quickly reprogram ordinary skin cells into entities that appear virtually identical to embryonic stem cells. Moreover, the same strategy can then turn those cells into ones that could be used for transplants.

"This is going to be very exciting to the research community," said Derrick J. Rossi of the Children's Hospital Boston, who led the research published in the journal Cell Stem Cell. "We now have an experimental paradigm for generating patient-specific cells highly efficiently and safely and also taking those cells to clinically useful cell types."

Scientists hope stem cells will lead to cures for diabetes, Alzheimer's disease, spinal cord injuries, heart attacks and many other ailments because they can turn into almost any tissue in the body, potentially providing an invaluable source of cells to replace those damaged by disease or injury. But the cells can be obtained only by destroying days-old embryos. _WaPo

A new induced stem cell technique from Harvard scientists promises to snowball into a bona fide breakthrough in regenerative medicine. Using messenger RNA (mRNA), a Harvard team has developed a safe and efficient technique for transforming virtually any cell type into an induced pluripotent stem cell.

Rossi said it was a happy coincidence that using RNA instead of changing the DNA was as much as 100-fold more efficient. He said the effect was possibly because the process more closely reflects how cells themselves transform.

Rossi successfully differentiated his stem cells into muscle cells using RNA, a process that may offer promise in gene therapy and other treatments. His method does not alter the cell's underlying genome, though Rossi admits that he does not yet understand what it does to the cell's epigenome, which controls expression of genes.

Rossi said that his cells, which he's named RiPS, for "RNA induced Pluripotent Stem" cells, are more like embryonic stem cells than traditional iPS cells because they have not been genetically altered.

Melton said the Harvard Stem Cell Institute, which includes several hundred stem-cell researchers from across Harvard University and its affiliated hospitals, will now be making its standard iPS cells with Rossi's method. _TechnologyReview

See WaPo RiPS video