Nanoparticle “backpack” repairs damaged stem cells.
Stem cells that might save a baby’s life and be utilized to treat illnesses like lymphoma and leukemia are found in the umbilical cord of newborns. Because of this, many new parents decide to preserve (“bank”) the umbilical cord blood’s abundant stem cells for their child. However, since gestational diabetes destroys stem cells and makes them useless, parents are not given this choice in the 6 to 15% of pregnancies who are impacted by the illness.
In a study that will be published in the journal Communications Biology, bioengineers at the University of Notre Dame have now shown that a new approach may heal the injured stem cells and allow them to once again grow new tissues.
Specially-created nanoparticles are the key component of this new strategy. Each spherical nanoparticle may store medication and deliver it specifically to the stem cells by attaching it to the surface of the cells. These nanoparticles are about 150 nanometers in diameter or about a fourth of the size of a red blood cell. The particles deliver the medication gradually as a result of their unique tuning, which makes them very effective even at very low dosages.
Donny Hanjaya-Putra, an assistant professor of aerospace and mechanical engineering in the bioengineering graduate program at Notre Dame who directs the lab where the study was conducted, described the process using an analogy. “Each stem cell is like a soldier. It is smart and effective; it knows where to go and what to do. But the ‘soldiers’ we are working with are injured and weak. By providing them with this nanoparticle ‘backpack,’ we are giving them what they need to work effectively again.”
The main test for the new “backpack”-equipped stem cells was whether or not they could form new tissues. Hanjaya-Putra and his team tested damaged cells without “backpacks” and observed that they moved slowly and formed imperfect tissues. But when Hanjaya-Putra and his team applied “backpacks,” previously damaged stem cells began forming new blood vessels, both when inserted in synthetic polymers and when implanted under the skin of lab mice, two environments meant to simulate the conditions of the human body.
Although it may be years before this new technique reaches actual health care settings, Hanjaya-Putra explained that it has the clearest path of any method developed so far. “Methods that involve injecting the medicine directly into the bloodstream come with many unwanted risks and side effects,” Hanjaya-Putra said. In addition, new methods like gene editing face a long journey to Food and Drug Administration (FDA) approval. But Hanjaya-Putra’s technique used only methods and materials already approved for clinical settings by the FDA.
Hanjaya-Putra attributed the study’s success to a highly interdisciplinary group of researchers. “This was a collaboration between chemical engineering, mechanical engineering, biology, and medicine — and I always find that the best science happens at the intersection of several different fields.”
The study’s lead author was former Notre Dame postdoctoral student Loan Bui, now a faculty member at the University of Dayton in Ohio; stem cell biologist Laura S. Haneline and former postdoctoral fellow Shanique Edwards from the Indiana University School of Medicine; Notre Dame Bioengineering doctoral students Eva Hall and Laura Alderfer; Notre Dame undergraduates Pietro Sainaghi, Kellen Round and 2021 valedictorian Madeline Owen; Prakash Nallathamby, research assistant professor, aerospace and mechanical engineering; and Siyuan Zhang from the University of Texas Southwestern Medical Center.
The researchers hope their approach will be used to restore cells damaged by other types of pregnancy complications, such as preeclampsia. “Instead of discarding the stem cells,” Hanjaya-Putra said, “in the future, we hope clinicians will be able to rejuvenate them and use them to regenerate the body. For example, a baby born prematurely due to preeclampsia may have to stay in the NICU with an imperfectly formed lung. We hope our technology can improve this child’s developmental outcomes.”
Reference: “Engineering bioactive nanoparticles to rejuvenate vascular progenitor cells” by Loan Bui, Shanique Edwards, Eva Hall, Laura Alderfer, Kellen Round, Madeline Owen, Pietro Sainaghi, Siyuan Zhang, Prakash D. Nallathamby, Laura S. Haneline, and Donny Hanjaya-Putra, 29 June 2022, Communications Biology.
The study was funded by Notre Dame’s Advancing Our Vision Initiative in Stem Cell Research, Notre Dame’s Science of Wellness Initiative, the Indiana Clinical and Translational Sciences Institute, the American Heart Association, and the National Institutes of Health.