Programming Cells to Target Specific Tissues May Enable More Effective Cell-Based Therapies

Stem cell therapies hold huge potential to tackle some of the most devastating disorders, diseases, and tissue defects worldwide. However, the inability to target cells to tissues of interest poses a considerable hurdle to effective cell therapy. To address this obstacle, researchers have devised a platform approach to incorporate chemically homing receptors onto the surface of cells. This simple application has the potential to improve the effectiveness of many types of cell therapies by increasing the concentrations of cells at target locations in the body.

The study’s findings were published online in the journal Blood on October 27, 2011. For this new platform, researchers modified the surface of cells to include receptors that act as a homing device. “The central hypothesis of our work is that the ability of cells to home to specific tissues can be enhanced, without otherwise altering cell function,” said corresponding author Jeffrey M. Karp, PhD, codirector of the Regenerative Therapeutics Center at Brigham and Women’s Hospital (BWH; Boston, MA, USA), and a principal faculty member of the Harvard Stem Cell Institute. “By knowing the ‘zip code’ [US postal code] of the blood vessels in specific tissues, we can program the ‘address’ onto the surface of the cells to potentially target them with high efficiencies.”

Whereas traditional cell therapies that include local administration of cells can be useful, they are typically more invasive with limited potential for multiple doses. “You can imagine, that when the targeted tissue is cardiac muscle, for example to treat heart attacks or heart failure, injecting the cells directly into the heart can be an invasive procedure and typically this approach can only be performed once,” said Dr. Karp, also an assistant professor at Harvard Medical School (Boston, MA, USA) and affiliate faculty Harvard-Massachusetts Institute of Technology (MIT) Division of Health Sciences and Technology (Cambridge, MA, USA).

Using the platform the researchers created, the cells are prepared to travel directly to the area of interest after being injected through a common and much less invasive intravenous infusion technique. “These engineered cells may also be more effective because multiple doses can be administered,” stated Debanjan Sarkar, PhD, previously a postdoctoral fellow in Dr. Karp’s lab and now an assistant professor of Biomedical Engineering at the State University of New York, University at Buffalo (NY, USA).

“The necessity for a more effective delivery approach stems from the potential diseases cell therapy may address,” said Dr. Karp, noting that the approach can be used to systemically target bone producing cells to the bone marrow to treat osteoporosis, cardiomyocytes to the heart to treat ischemic tissue, neural stem cells to the brain to treat Parkinson’s disease, or endothelial progenitor cells to sites of peripheral vascular disease to promote formation of new blood vessels.

The researchers concluded that, as the determination of the processes of cell trafficking grows, the capability to improve homing to specific tissues through engineered techniques should considerably enhance cell therapy by reducing the invasiveness of local administration, allowing repeat dosing, and potentially reducing the number of cells needed to achieve a therapeutic effect, in the end providing better outcomes for patients.

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