Longitudinal, 3D Imaging of Collagen Remodeling in Murine Hypertrophic Scars In Vivo Using Polarization-Sensitive Optical Frequency Domain Imaging

Abstract

Hypertrophic scars (HTS), frequently seen after traumatic injuries and surgery, remain a major clinical challenge due to the limited success of existing therapies. A significant obstacle to understanding HTS etiology is the lack of tools to monitor scar remodeling longitudinally and non-invasively. We present an in vivo, label-free technique using polarization-sensitive optical frequency domain imaging (PS-OFDI) for the 3D, longitudinal assessment of collagen remodeling in murine HTS. In this study, HTS was induced with a mechanical tension device for 4 to 10 days on incisional wounds and imaged up to one month after device removal; an excisional HTS model was also imaged at 6 months after injury to investigate deeper and more mature scars. We showed that local retardation (LR) and degree of polarization (DOP) provide a robust signature for HTS. Compared to normal skin with heterogeneous LR and low DOP, HTS was characterized by an initially low LR, which increased as collagen fibers remodeled, and a persistently high DOP. This study demonstrates that PS-OFDI offers a powerful tool to gain significant biological insights into HTS remodeling by enabling longitudinal assessment of collagen in vivo, which is critical to elucidating HTS etiology and developing more effective HTS therapies.

Polarization sensitive optical coherence tomography – a review [Invited]

“…A good deal of work has been done towards establishing baselines for the polarization properties of normal human skin as PS-OCT technology has progressed [15,145,[148][149][150]. This work has helped pave the way towards assessment of burns in humans [49, [151][152][153], and the assessment of scars [145,153,154]. In dermatology PS-OCT has also been used to asses dermal photoageing [155], and for the identification and delineation of basal cell carcinoma [156].…”

Three-dimensional multi-contrast imaging of in vivo human skin by Jones matrix optical coherence tomography

“…The uniformity of polarization property of tissue is also useful for dermatological investigation [36]. It was recently applied to investigate hypertrophic scars [37]. OCT-A has also been applied to dermatological investigations.…”

Dermoscopy guided dark-field multi-functional optical coherence tomography

“…Polarization-sensitive OCT (PS-OCT) provides polarization properties of tissues such as birefringence, and it is useful for distinguishing lesions from normal tissues if the normal ones have polarization properties. PS-OCT has been applied to studying various organs including the skin [16][17][18][19][20][21][22][23]. Angiographic OCT based on flow characteristics provides additional vascular information within tissue, such as diameter, shape and distribution of blood vessels and their perfusion.…”