title: Tissue-engineered constructs of human oral mucosa examined by Raman spectroscopy.
abstract: A noninvasive quality monitoring of tissue-engineered constructs is a required component of any successful tissue-engineering technique. During a 2-week production period, ex vivo produced oral mucosa-equivalent constructs (EVPOMEs) may encounter adverse culturing conditions that might compromise their quality and render them ineffective. We demonstrate the application of near-infrared Raman spectroscopy to in vitro monitoring of EVPOMEs during their manufacturing process, with the ultimate goal of applying this technology in situ to monitor the grafted EVPOMEs. We identify Raman spectroscopic failure indicators for less-than optimal EVPOMEs that are stressed by higher temperature and exposure to higher than normal concentration of calcium ions. Raman spectra of EVPOMEs exposed to thermal and calcium stress showed correlation of the band height ratio of CH(2) deformation to phenylalanine ring breathing modes, providing a Raman metric to distinguish between viable and nonviable constructs. We compared these results to histology and glucose consumption measurements, demonstrating that Raman spectroscopy is more sensitive and specific to changes in proteins' secondary structure not visible by H&E histology. We also exposed the EVPOMEs to rapamycin, a cell growth inhibitor and cell proliferation capacity preserver, and distinguished between EVPOMEs pretreated with 2 nM rapamycin and controls, using the ratio of the Amide III envelope to the phenylalanine band as an indicator.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Khmaladze
authors.forename: Arindam
authors.initials: A
authors.lastname: Ganguly
authors.forename: Shiuhyang
authors.initials: S
authors.lastname: Kuo
authors.forename: Mekhala
authors.initials: M
authors.lastname: Raghavan
authors.forename: Raghu
authors.initials: R
authors.lastname: Kainkaryam
authors.forename: Jacqueline H
authors.initials: JH
authors.lastname: Cole
authors.forename: Kenji
authors.initials: K
authors.lastname: Izumi
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Marcelo
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Feinberg
authors.forename: Michael D
authors.initials: MD
authors.lastname: Morris
mesh_terms: D002118:Calcium / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D009061:Mouth Mucosa; D020123:Sirolimus / Q000494:pharmacology; D013059:Spectrum Analysis, Raman / Q000379:methods*; D023822:Tissue Engineering
chemical_list: D005947:Glucose; D002118:Calcium; D020123:Sirolimus