Human collagen decorating microneedle patches for transdermal therapy

Abstract Collagen, the major structural protein in various tissues, is an ideal material for tissue regeneration. However, the collagen molecules cannot penetrate across the skin barrier due to their large molecular weight. It is necessary to develop new methods of delivery for promoting the collagen‐based therapy. Microneedle patches have been used in drug delivery applications as an alternative to traditional puncture delivery. In this study, the human collagen decorating microneedle patch was developed to deliver the collagen into the skin tissue, as the human‐source collagen can overcome the immunogenicity of animal‐source collagens in regenerative applications. The human collagen is usually limited by its source. Here, the collagen is derived from an allogeneic extracellular matrix expressed by human stem cells in vitro. The collagen was then loaded on the tip of the microneedle to achieve a high‐loading dose and efficient delivery. The experimental results proved that the microneedles were sharp and rigid enough to pierce the skin, which has the potential to be used for subcutaneous tissue regeneration. Moreover, the fabrication process was simple and effective to realize large‐scale production.