Researchers at the Terasaki Institute in Los Angeles have developed a microneedle patch to deliver mesenchymal stem cells (MSCs) into the skin. The biodegradable needles contain a gelatin matrix in which MSCs can survive. Once applied to the skin and removed, the needles detach from the patch and remain within the tissue. The hard outer shell of the needles breaks down over time and allows the cells within to provide therapeutic effects on the surrounding tissue. MSCs have significant therapeutic potential in a wide variety of disease states. They show particular promise in a regenerative capacity, in applications such as wound healing or post-infarct tissue regeneration. However, delivering these cells to the site of therapy and keeping them there, alive and kicking, has proven to be a major challenge, and a sticking point in unlocking their full therapeutic potential. Researchers have developed a wide variety of biomaterial delivery systems in response to this issue. This latest approach is a little different, and is intended to deliver and retain MSCs in superficial tissues, with potential applications in wound healing. “Microneedles have been successfully used in the past to painlessly deliver drugs to target tissues such as skin, blood vessels and eyes. We demonstrate here with ‘Detachable Microneedle Depots’ that an analogous approach can deploy therapeutic cells at target sites,” said Ali Khademhosseini, a researcher involved in the study. “To achieve this, we developed an entirely new microneedle patch that supports stem cells’ viability, responsiveness to wound stimuli, and ability to accelerate wound healing.” In this latest study, published in the journal Advanced Functional Materials, the MSCs are encapsulated in a cross-linked gelatin matrix that supports cell survival and therapeutic function. The soft matrix is contained in a hard, biodegradable shell that forms the surface of the needle. The needles penetrate the tissue when the patch is applied to the skin. Once the patch is removed the needles detach and remain embedded within the tissue. The hard outer shell breaks down over time, allowing the cells encased within to exert effects on the surrounding tissue. So far, the researchers have tested the system in a rodent wound healing model, and found that a patch loaded with MSCs accelerated wound healing and skin regrowth. “In future scenarios, Detachable Hybrid Microneedle Depots could be rapidly fabricated in clinical laboratories shortly before use, applied to treat skin injuries, and explored more broadly as treatments for a variety of other disorders, including melanoma and other dermatological disorders that could benefit from the power of MSC cells,” added Khademhosseini. “The concept would even be compatible with using patient-derived cells in more personalized device approaches.” Study in Advanced Functional Materials: A Patch of Detachable Hybrid Microneedle Depot for Localized Delivery of Mesenchymal Stem Cells in Regeneration Therapy Source
