title: Photoacoustic monitoring of granulation tissue grown in a grafted artificial dermis on rat skin.
abstract: In this study, we investigated the validity of photoacoustic (PA) measurement for monitoring granulation tissue and hence adhesion of grafted artificial dermis (AD). A 2.5 cm x 2.5 cm, 3-mm-thick AD composed of an atelocollagen sponge sheet and a silicone film was grafted on a full-thickness open wound in rat dorsal skin. The grafted AD was irradiated with low-energy, 532-nm nanosecond laser pulses to photoacoustically excite blood in neovascularities, and the PA signals induced were measured using a piezoelectric transducer as a function of postgrafting time. The PA signals were compared with results of laser Doppler imaging and histological analysis. We found a significant correlation between the depths of the first or shallowest PA signal peaks and the depths of granulation tissues estimated from histology with hematoxylin & eosin staining (R=0.951, p<0.05). There was also a significant correlation between the amplitudes of the first PA signal peaks and densities of CD31-positive cells evaluated from histology with immunohistochemical staining (R=0.859, p<0.05). With laser Doppler imaging, no clear perfusion signals were observed, which is attributable to a high light scattering loss in ADs. These findings suggest the validity of PA measurement for monitoring the adhesion of grafted ADs.
authors.affiliation: Department of Traumatology and Critical Care Medicine, National Defense Medical College, Saitama, Japan.
authors.forename: Kousuke
authors.initials: K
authors.lastname: Hatanaka
authors.forename: Shunichi
authors.initials: S
authors.lastname: Sato
authors.forename: Daizoh
authors.initials: D
authors.lastname: Saitoh
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ashida
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Sakamoto
mesh_terms: D000162:Acoustics; D000818:Animals; D006097:Granulation Tissue / Q000502:physiology*; D007089:Image Enhancement; D028022:Low-Level Light Therapy; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D016038:Skin Transplantation / Q000502:physiology; D017768:Skin, Artificial; D014945:Wound Healing / Q000502:physiology