A New Way to Prepare Fat-Based Stem Cells to Treat Wounds


An Italian laboratory headed by Dr. Raposio at the University of Parma has designed a simple and fast technique for preparing fat-based stem cells for use in the clinic.

Fat contains an alternative source of mesenchymal stem cells with characteristics similar to those found in bone marrow, but the fat-based stem cells are easier to isolate and have been shown to be effective enhancers of wound healing.

Raposio and his colleagues used fat contributed by liposuction patients. Each patient provided about 80 cubic centimeters of fat in liposuction procedures that were collected under anesthesia. Once the cells from this fat were isolated, they were mixed with platelet-rich plasma (PRP) that had been previously collected. Mixing PRP with stem cells enhances the capabilities of the fat-based stem cells and generates a concoction called “e-PRP.”  This simple procedure that consisted of fat collection, stem cell collection and mixing the cells with PRP to make e-PRP quickly made a produce that was ready for grafting onto wounds on the skin.

Detailed analyses of the cells isolated from the fat showed that they consisted of about 50,000 fat-based mesenchymal stem cells or ASCs. They represented about 5% of all cells in the sample. The remaining cells were blood-derived cell and blood vessel-making endothelial cells.

The significance of this procedure lies in the fact that most of the protocols used to isolate stem cells from fat take about two hours and require animal-derived reagents. However, the number of ASCs isolated with this new procedure is sufficient for application to wounds without the need of expanding the cells in culture. Also, this new procedure does not require serum or animal-derived reagents, and it takes only 15 minutes.

Thus this method of ASC isolation is innovative, feasible, and represents an advance in the stem cell-based treatment of chronic wounds.

Sweat Glands Are A Source of Stem Cells for Wound Healing


Stem Cells from human sweat glands serve as a remarkable source for wound healing treatments according to a laboratory in Lübeck, Germany.

Professor Charli Kruse, who serves as the head of the Fraunhofer Research Institute for Marine Biotechnology EMB, Lübeck, Germany, and his colleagues isolated cultured pancreatic cells in the course of their research to look into the function of a protein called Vigilin. When the pancreatic cells were grown in culture, they produced, in addition to other pancreatic cells, nerve and muscle cells. Thus the pancreas contains a stem cell population that can differentiate into different cell types.

Kruse and his group decided to investigate other glands contained a similar stem cell population that could differentiate into other cell types.

Kruse explained: “We worked our way outward from the internal organs until we got to the skin and the sweat glands. Again, this yielded the same result: a Petri dish full of stem cells.”

Up to this point, sweat glands have not received much attention from researchers. Mice and rats only have sweat glands on their paws, which makes them rather inaccessible. Human beings, on the other hand, have up to three million sweat glands, predominantly on the soles of out feet, palms of the hand, armpits, and forehead.

Ideally, a patient could have stem cells taken from her own body to heal an injury, wound, or burn, Getting to these endogenous stem cell populations, however, represents a challenge, since it requires bone marrow biopsies or aspirations, liposuction, or some other invasive procedure.

Sweat glands, however, are significantly easier to find, and a short inpatient visit to your dermatologist that extracts three millimeters of underarm skin could provide enough stem cells to grow in culture for treatments.

Stem cells from sweat glands have the capacity to aid wound healing. Kruse and his group used sweat gland-based stem cells in laboratory animals. The Kruse group used skin biopsies from human volunteers and separated out the sweat gland tissues under a dissecting scope. Then the sweat gland stem cells were grown in culture and induced to differentiate into a whole host of distinct cell types.

Then Kruse’s team grew these sweat gland stem cells in a skin-like substrate that were applied to wounds on the backs of laboratory animals. Those animals that had received stem cell applications healed faster than those that received no stem cells.

If the stem cells were applied to the mice with the artificial substrate, the cells moved into the bloodstream and migrated away from the site of the injury. In order to help heal the wound the cells had to integrate into the skin and participate in the healing process.

“Not only are stem cells from sweat glands easy to cultivate, they are extremely versatile, too,” said Kruse.

Kruse and his team are already in the process of testing a treatment for macular degeneration using sweat gland-based stem cells. “In the long-term, we could possibly set up a cell bank for young people to store stem cells from their own sweat glands/ They would then be available for use should the person need new cells, following an illness,l perhaps, or in the event of an accident,” Kruse said.

Wound Healing Therapy That Combines Gene and Stem Cell Therapy


Researchers from Johns Hopkins University have examined wound healing in older mice and discovered that increasing blood flow to the wound can increase the rate of wound healing. Increasing blood flow to the wound requires a combination of gene therapy and the same stem cells the body already uses to heal itself.

John W. Harmon is professor of surgery at Johns Hopkins School of Medicine, and in a presentation to the American College of Surgeons’ Surgical Club, made the case that harnessing the power of bone marrow stem cells can increase the rate at which older people heal.

As we age, our wounds do not heal as fast. However, Harmon thinks that harnessing the power of bone marrow stem cells can remedy this disparity in healing rates.

To heal burns or other wounds, stem cells from the one marrow rush into action and home to the wound where they can differentiate into blood vessels, skin, and other reparative tissues. Stem cell homing is mediated by a protein called Hypoxia-Inducible-Factor-1 (HIF-1). According to Harmon, in older patients, few of these stem cells are released from the bone marrow and there is a deficiency of HIF-1. HIF-1 was actually discovered about 15 years ago by one of Harmon’s collaborators, a Johns Hopkins scientist named Gregg J. Semenza.

HIF-1
HIF-1

Harmon’s first strategy was to boost HIF-1 levels by means of gene therapy. This simply consisted of injecting the rodents with a copy of the HIF-1 gene that yielded higher levels of HIF-1 expression.

Even though higher levels of HIF-1 improved wound healing rates, burns were another story. To accelerate burn healing, Harmon and his co-workers used bone marrow stem cells from younger mice combined with the increased levels of HIF-1. This combination of HIF-1 and bone marrow stem cells from younger mice led to accelerated healing of burns so that after 17 days, almost all the mice had completely healed burns. These animals that healed so fast showed better blood flow to the wound and more blood vessels supplying the wound.

Harmon said that while this strategy is promising, he think that a procedure that uses a patient’s own bone marrow cells would work better since such cells would have a much lower chance of being rejected by the patient’s immune system. In the meantime, HIF-1 gene therapy has been successfully used in humans with a sudden lack of blood flow to a limb (see Rajagopalan S., et al., Circulation. 2007 Mar 13;115(10):1234-43). Harmon postulated that “it’s not a stretch of the imagination to think this could someday be used in elderly people with burns or other difficult wounds.”