Noninvasive optical assessment of implanted tissue-engineered construct success in situ.

Quantitative diffuse reflectance spectroscopy (DRS) was developed for label-free, noninvasive, and real-time assessment of implanted tissue-engineered devices manufactured from primary human oral keratinocytes (six batches in two five-patient cohorts). Constructs were implanted in a murine model for one and three weeks. DRS evaluated construct success in situ using optical absorption (hemoglobin concentration and oxygenation, attributed to revascularization) and optical scattering (attributed to cellular density and layer thickness). Destructive pre- and post-implantation histology distinguished experimental control from stressed constructs, whereas noninvasive pre-implantation measures of keratinocyte glucose consumption and residual glucose in spent culture media did not. In constructs implanted for one week, DRS distinguished control due to stressed and compromised from healthy constructs. In constructs implanted for three weeks, DRS identified constructs with higher post-implantation success. These results suggest that quantitative DRS is a promising, clinically-compatible technology for rapid, noninvasive, and localized tissue assessment to characterize tissue-engineered construct success in vivo.