title: Noninvasive in situ evaluation of osteogenic differentiation by time-resolved laser-induced fluorescence spectroscopy.
abstract: The clinical implantation of bioengineered tissues requires an in situ nondestructive evaluation of the quality of tissue constructs developed in vitro before transplantation. Time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) is demonstrated here to noninvasively monitor the formation of osteogenic extracellular matrix (ECM) produced by putative stem cells (PLA cells) derived from human adipose tissue. We show that this optical spectroscopy technique can assess the relative expression of collagens (types I, III, IV, and V) within newly forming osteogenic ECM. The results are consistent with those obtained by conventional histochemical techniques (immunofluorescence and Western blot) and demonstrate that TR-LIFS is a potential tool for monitoring the expression of distinct collagen types and the formation of collagen cross-links in intact tissue constructs.
authors.affiliation: Laboratory for Regenerative Bioengineering and Repair, Departments of Surgery and Orthopedics, UCLA School of Medicine, Los Angeles, CA 90095, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Ashjian
authors.forename: Amir
authors.initials: A
authors.lastname: Elbarbary
authors.forename: Patricia
authors.initials: P
authors.lastname: Zuk
authors.forename: Daniel A
authors.initials: DA
authors.lastname: DeUgarte
authors.forename: Prosper
authors.initials: P
authors.lastname: Benhaim
authors.forename: Laura
authors.initials: L
authors.lastname: Marcu
authors.forename: Marc H
authors.initials: MH
authors.lastname: Hedrick
mesh_terms: D015153:Blotting, Western; D001842:Bone and Bones / Q000166:cytology / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D003094:Collagen / Q000276:immunology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D010012:Osteogenesis / Q000502:physiology*; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: D003094:Collagen