ABSTRACT
BACKGROUND: Translation of cell therapies to the clinic is accompanied by numerous challenges, including controlled and targeted delivery of the cells to their site of action, without compromising cell viability and functionality. OBJECTIVES: To explore the use of hollow microneedle devices (to date only used for the delivery of drugs and vaccines into the skin and for the extraction of biological fluids) to deliver cells into skin in a minimally invasive, user-friendly and targeted fashion. METHODS: Melanocyte, keratinocyte and mixed epidermal cell suspensions were passed through various types of microneedles and subsequently delivered into the skin. RESULTS: Cell viability and functionality are maintained after injection through hollow microneedles with a bore size ≥ 75 µm. Healthy cells are delivered into the skin at clinically relevant depths. CONCLUSIONS: Hollow microneedles provide an innovative and minimally invasive method for delivering functional cells into the skin. Microneedle cell delivery represents a potential new treatment option for cell therapy approaches including skin repigmentation, wound repair, scar and burn remodelling, immune therapies and cancer vaccines.
