Thermally induced irreversible conformational changes in collagen probed by optical second harmonic generation and laser-induced fluorescence. 2002

T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
Biomedical Optics and Applied Biophysics Laboratory, Department of Electrical and Computer Engineering, Division of Electromagnetics, Electrooptics and Electronic Materials, National Technical University of Athens, Zografou, Greece. theo_th@hotmail.com

Irreversible thermal conformational changes induced to collagen have been studied by optical methods. More specifically, second harmonic generation (SHG) from incident nanosecond Ng:YAG 1064 nm radiation and laser-induced fluorescence by 337 nm, pulsed nanosecond nitrogen laser excitation, at 405, 410 and 415 nm emission wavelengths were registered at eight temperatures (40 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees and 80 degrees C) and normalised with respect to the corresponding values at the ambient temperature of 30 degrees C. The heating protocol used in this work, was selected to monitor only permanent changes reflecting in the optical properties of the samples under investigation. In this context, the SHG, directly related to the collagen fibril population in triple helix conformation, indicated on irreversible phase transition around 64 degrees C. On the other hand fluorescence related to the destruction of cross-linked chromophores in collagen, some of which are related to the triple helix tertiary structure, also indicated a permanent phase transition around 63 degrees C. These results are in agreement with previous results from studies with differential scanning calorimetry. However SHG and fluorescence, being non-invasive optical methods are expected to have a significant impact in the fields of laser ablative surgery and laser tissue welding.

UI MeSH Term Description Entries
D007834 Lasers An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum. Masers,Continuous Wave Lasers,Pulsed Lasers,Q-Switched Lasers,Continuous Wave Laser,Laser,Laser, Continuous Wave,Laser, Pulsed,Laser, Q-Switched,Lasers, Continuous Wave,Lasers, Pulsed,Lasers, Q-Switched,Maser,Pulsed Laser,Q Switched Lasers,Q-Switched Laser
D011487 Protein Conformation The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain). Conformation, Protein,Conformations, Protein,Protein Conformations
D011489 Protein Denaturation Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein. Denaturation, Protein,Denaturations, Protein,Protein Denaturations
D002417 Cattle Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor. Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D003094 Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH). Avicon,Avitene,Collagen Felt,Collagen Fleece,Collagenfleece,Collastat,Dermodress,Microfibril Collagen Hemostat,Pangen,Zyderm,alpha-Collagen,Collagen Hemostat, Microfibril,alpha Collagen
D005453 Fluorescence The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
D006358 Hot Temperature Presence of warmth or heat or a temperature notably higher than an accustomed norm. Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D013050 Spectrometry, Fluorescence Measurement of the intensity and quality of fluorescence. Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D066298 In Vitro Techniques Methods to study reactions or processes taking place in an artificial environment outside the living organism. In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In

Related Publications

T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
April 2023, Nature communications,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
August 2006, The Journal of chemical physics,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
March 2005, Optics letters,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
May 2013, Optics express,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
May 2017, Langmuir : the ACS journal of surfaces and colloids,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
January 2020, Physical review letters,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
January 2019, Journal of the Royal Society, Interface,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
February 2022, Cancers,
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
February 2023, Materials (Basel, Switzerland),
T Theodossiou, and G S Rapti, and V Hovhannisyan, and E Georgiou, and K Politopoulos, and D Yova
October 2004, Optics letters,
Copied contents to your clipboard!