Visualization and characterisation of defined hair follicle compartments by Fourier transform infrared (FTIR) imaging without labelling

Background: To visualise and characterise skin architecture, the tissue usually has to be destroyed and labelled. Objectives: The use of Fourier transform infrared (FTIR) spectroscopy as a label-free, minimally sample destructive method to define hair follicular structure has been explored and demonstrated in this paper. Methods: Human scalp skin cryosections were imaged using FTIR microscopy and the data was subsequently analysed with N-FINDR spectral unmixing algorithm. Results: This resulted in an excellent distinction of known hair follicle tissue layers, which could be discerned based on their molecular structure. Conclusion: The development of a minimally sample-destructive, label-free spectroscopy based technique that can differentiate layers of cells in the dermal papilla and connective tissue sheath in the mesenchyme of the hair follicle paves the way forward to identifying spectral markers important in wound healing and stem cell therapies.