Injected Fibroblasts Toughen Up Thin Skin

The thick and tough skin on our palms and soles, called volar skin, stands up well under high-pressure conditions. This type of skin would be welcome on the limb stumps of amputees, since these points of contact with prostheses are covered in thin, non-volar skin that can be damaged over time. Now, Sam Lee and colleagues demonstrate that an injection of volar fibroblasts into non-volar skin in a group of human volunteers can promote volar features in the thin skin that last up to five months. Based on their analysis, Lee et al. are now enrolling amputees in a phase 2 clinical trial to further explore volar fibroblasts as a future therapy for treating pressure-caused skin damage. In the United States, more than 1.7 million people have lost limbs, most often from trauma, diabetes or vasculopathy, and may be reluctant to wear prostheses due to pain or skin breakdown. The researchers used a combination of live imaging of cells, gene expression analysis, mechanical pressure testing and bioprinting to characterize volar and non-volar fibroblasts and their features related to resilience to pressure. Fiona Watt discusses these results in a related Perspective.