Biophotonics II general remarks

Transcription

1 general remarks BIOPHOTONICS I (WS 2017/18) I. Imaging Systems human vision microscopy II. Light Scattering Mie scattering light propagation in tissue BIOPHOTONICS II (SS 2018) III. Biospectroscopy Fluorescence spectroscopy Phosphorescence, bio- and chemiluminescence Vibrational spectroscopy IV. Lasers in medicine Laser interaction with tissue Applications Literature: Bergmann-Schäfer, Optik (Walter de Gruyter) E. Hecht, Optik (Addison-Wesley) J. Bille, W. Schlegel, Medizinische Physik 3 (Springer) P.N. Prasad, Biophotonics (Wiley) T. Vo-Dinh, Biomedical Photonics Handbook (CRC Press) V.V Tuchin, Handbook of Optical Biomedical Diagnostics (SPIE Press) G.G. Hammes, Spectroscopy for the biological sciences (Wiley) J.R. Lakowicz, Principles of Fluorescence Spectroscopy (Springer) It is NOT required to have attended the Biophotonics I lecture prior to visiting Biophotonics II. Lecture Biophotonics II will be credited with 2 CP subject to successfully passing the written exam. If you intend to obtain credit points, i.e. to participate in the exam, you will have to register at: Prof. Dr. Petrich Biophotonics II (SS 2018) 1

2 lecture #8 (June 18 th, 2018): summary III.5.2. Biomedical vibrational spectroscopy water A) mid-infrared spectroscopy (2.5 µm 25 µm) options for mitigate the impact of water: 1. short interaction length ( Lambert-Beer s law) high pressure cuvette attenuated total reflection (ATR) 2. high spectral power density synchrotron radiation lead salt lasers (LN2-cooling) quantum cascade lasers 3. Drying ( biofilm technology) FT-IR B) near infrared spectroscopy V kr k' r... ~ 1 ~ 1 Evib hc n X ehc n ( R R0 ) ( R R0 )... 2 R 2 R R0 R0 7 hc ~ 2 hc ~ 7 49 ~ X ~ e hc 5 hc ~ hc (1 6X hc ~ e ) 5 25 X ~ e hc 3 hc ~ ~ 2 4 hc (1 4X e ) 2 hc ~ 3 9 X ~ e hc ~ 1 hc ~ hc (1 2X ) 2 4 e X ~ e hc 2 4 harmonic oscillator anharmonic oscillator n 1 n 1, 2, 3, (weak) overtones and combination bands readily available technology C) Raman spectroscopy I R ~ N m red 2 ( vib ) (1 e vib 4 h kt weak signal when compared to fluorescence fluorescence background hampers S/N ) Prof. Dr. Petrich Biophotonics II (SS 2018) 2

3 IV. Lasers in medicine IV. LASERS IN MEDICINE Prof. Dr. Petrich Biophotonics II (SS 2018) 3

4 IV. 1. Laser basics IV.1 Laser basics 1917 A. Einstein postulates stimulated emission 1923 R. Ladenburg first experimental observation of stimulated emission 1954 C. Townes Microwave Amplification by Stimulated Emission of Radiation (MASER)* 1960 T. Maiman Light Amplification by Stimulated Emission of Radiation (LASER) * Means of Acquiring Support for Expensive Research Source: wikipedia.org Prof. Dr. Petrich Biophotonics II (SS 2018) 4

5 IV. 1. Laser basics Properties of laser radiation: High power Large spectral power density Small linewidth Narrow emission angle (small divergence) Small beam parameter product Small beam diameter Example: 100 W laser light focussed down to a 2µm diameter spot intensity: 1GW/cm² electric field: 60 MV/m photon flux (e.g. = 600 nm, i.e. h = J per photon) photons per cm² and second high degree of coherence Example: Hg lamp HeNe laser 546 nm nm 1 GHz bandpass filter 1 MHz linewidth L c ~ 0,1m ~ 100 m Prof. Dr. Petrich Biophotonics II (SS 2018) 5

6 IV.1. Laser basics Source: wikipedia.org Wavelengths of commercially available lasers. Laser types with distinct laser lines are shown above the wavelength bar, while below are shown lasers that can emit in a wavelength range. The height of the lines and bars gives an indication of the maximal power/pulse energy commercially available, while the color codifies the type of laser material (see the figure description for details). Most of the data comes from Weber's book Handbook of laser wavelengths, [1] with newer data in particular for the semiconductor lasers. Prof. Dr. Petrich Biophotonics II (SS 2018) 6

7 absorption coefficient of water [1/cm] XeF XeCl KrF Nd:YLF Nd:YAG Ho:YAG Er:YAG ArF Argon-ion Nd:YAG (2 ) Krypton-ion Ruby Biophotonics II IV.2. Lasers in biology and medicine IV.2 Laser in biology and medicine CO ,1 Zolotarev et al. Hale et al. Irvine et al. 0,01 1E-3 1E-4 Alexandrite Ti:Sapphire diode var. dyes a (dermis) s ' (dermis) a (HbO in blood) a (Hb in blood) wavenumber [cm -1 ] wavelength [ m] 1 10 photon energy [ev] frequency [THz] ,1 Prof. Dr. Petrich Biophotonics II (SS 2018) 7

8 IV.2. Lasers in biology and medicine From: P. Prasad, Introduction to Biophotonics, Wiley (2003) Prof. Dr. Petrich Biophotonics II (SS 2018) 8

9 IV.2. Lasers in biology and medicine Prof. Dr. Petrich Biophotonics II (SS 2018) 9

10 IV.2. Lasers in biology and medicine IV.6. photodisruption and plasmainduced interaction IV.5. photoablation IV.4. photothermal interaction IV.3. photochemical interaction Prof. Dr. Petrich Biophotonics II (SS 2018) 10

11 IV.3 Photochemical interaction IV.3. photochemical interaction Prof. Dr. Petrich Biophotonics II (SS 2018) 11

12 IV. Lasers in medicine IV.3. photochemical interaction IV.3.1. effects of ultraviolett radiation Name Abbreviation Wavelength range Energy per photon Notes / alternative names Ultraviolet UV nm ev Ultraviolet A UVA nm ev long wave, black light, not absorbed by the ozone layer Ultraviolet B UVB nm ev Ultraviolet C UVC nm ev medium wave, mostly absorbed by the ozone layer short wave, germicidal, completely absorbed by the ozone layer and atmosphere Near Ultraviolet NUV nm ev visible to birds, insects and fish Middle Ultraviolet MUV nm ev Far Ultraviolet FUV nm ev Hydrogen Lyman-alpha H Lyman-α nm ev Extreme Ultraviolet EUV nm ev Vacuum Ultraviolet VUV nm ev Prof. Dr. Petrich Biophotonics II (SS 2018) 12

13 IV.3. Photochemical interaction damage in tissue by ultraviolett radiation 95% of the sun s UV radiation on earth surface is in the UV-A spectral range (thanks to the ozone layer) 1 hour of sunbathing Prof. Dr. Petrich Biophotonics II (SS 2018) 13

14 IV.3. Photochemical interaction damage in tissue by ultraviolett radiation UV-C UV-B UV-A 95% of the sun s UV radiation on earth surface is in the UV-A spectral range (thanks to the ozone layer) R.R. Anderson, J.A. Parrish, J. Invest.Dermat. 77(1981)13-19 Prof. Dr. Petrich Biophotonics II (SS 2018) 14

15 Biophotonics II IV.3. Photochemical interaction damage in tissue by ultraviolett radiation UV-C UV-B UV-A Excited state lifetimes of pyrimidines ~ 1ps due to internal conversion Most of excitation dissipated into heat, only few excited state reactions R.R. Anderson, J.A. Parrish, J. Invest.Dermat. 77(1981)13-19 See also: Kang et al, JACS 124 (2002) Prof. Dr. Petrich Biophotonics II (SS 2018) 15

16 IV.3. Photochemical interaction damage in skin by ultraviolett radiation Name Wavelength range Ultraviolet UV nm Ultraviolet A UVA nm Ultraviolet B UVB nm Ultraviolet C UVC nm Prof. Dr. Petrich Biophotonics II (SS 2018) 16

17 Biophotonics II IV.3. Photochemical interaction damage in skin by ultraviolett radiation UV-A Damages collagen fibre (skin aging) Destroys vitamin A Triggers release of melanin Stimulates vitame D production Does not cause reddening of skin Penetrates into basal epidermal layer i.e. deeper into skin than UV-B UV-B Damages collagen fibre (skin aging) Destroys vitamin A Causes production of melanin Damage mainly in superficial epidermal layer, i.e. not as deep as UV-A Direct DNA damage UV-B excited state reaction of DNA (formation of cyclobutane pyrimidine dimers) Indirect DNA damage UV-A Highly reactive intermediates (hydroxyl, oxygen radical) single strand breakage in DNA Note: UV-C is most dangerous UV radiation! 99% nucleotide excision repair 1% apoptosis or mutation Prof. Dr. Petrich Biophotonics II (SS 2018) 17

18 IV.3. Photochemical interaction Desinfection by ultraviolett germicidal irraditation (typ.: low pressure mercury 254nm) Direct DNA damage UV-C excited state reaction of DNA (formation of cyclobutane pyrimidine dimers) double strand break Prof. Dr. Petrich Biophotonics II (SS 2018) 18

19 IV.3. Photochemical interaction Prof. Dr. Petrich Biophotonics II (SS 2018) 19

20 IV. Lasers in medicine IV.3.2. photodynamic therapy Prof. Dr. Petrich Biophotonics II (SS 2018) 20

21 IV. Lasers in medicine IV.3.2. photodynamic therapy Theranostics 2013; 3(9): doi: /thno Prof. Dr. Petrich Biophotonics II (SS 2018) 21

22 IV.3. photochemical interaction: molecular oxygen Source: wikipedia.org Prof. Dr. Petrich Biophotonics II (SS 2018) 22

23 IV.3. photochemical interaction: molecular oxygen From: Haken, Wolf: Molekülphysik und Quantenchemie Atkins: Physikalische Chemie Prof. Dr. Petrich Biophotonics II (SS 2018) 23

24 IV.3. photochemical interaction: molecular oxygen t = 4µs Source: Prof. Dr. Petrich Biophotonics II (SS 2018) 24

25 IV.3.2. photodynamic therapy PDT sensitizer ( 1 P) h PS ( 1 P*) PS ( 3 P*) inter system crossing PS( 3 P*) + H 2 O PS + OH + H PS( 3 P*) + 3 O 2 PS( 1 P) + 1 O 2 * free radical singlet oxygen Prof. Dr. Petrich Biophotonics II (SS 2018) 25

26 IV.3.2. photodynamic therapy PDT mechanisms cellular vascular immunological localization in mitochondria apoptosis localization in membrane necrosis activation of thrombocytes microvascular statis hypoxia tumor regression stimulation of anti-tumor immunity inflammatory response tumor specific antigens induction of heat-shock proteins figures taken from: P. Mroz et al., Proc. SPIE 7565 (2010) W. Wang et al., Laser Phys Lett. 10 (2013) Prof. Dr. Petrich Biophotonics II (SS 2018) 26

27 IV.3.2. photodynamic therapy h h 1 O 2 and other reactive oxygen species no photochemical reaction protoporphyrin IX accumulates in neoplastic tissue selective tumor treatment Prof. Dr. Petrich Biophotonics II (SS 2018) 27

28 IV.3.2. photodynamic therapy Photodynamic Therapy for Skin Cancer. The top image shows a malignant skin lesion just above the circled number 3. A photosensitizer was administered to this patient, and at an appropriate time afterward the lesion was illuminated with a laser emitting red light at 630 nm, a wavelength that is absorbed by the photosensitizer. The middle picture shows the lesion immediately after this illumination period. You can see the reddening that is induced by the treatment, as malignant cells are being lethally injured. The reddening gradually clears, leaving behind only normal skin cells, as shown in the bottom picture. From: Prof. Dr. Petrich Biophotonics II (SS 2018) 28

29 biosynthesis of protoporphyrin IX From: en.wikipedia.org Prof. Dr. Petrich Biophotonics II (SS 2018) 29

30 Biophotonics II IV.3.2. photodynamic therapy Fluorescence emitted from basal carcinomas treated with 5-aminolevulinic acid methyl ester (5-ALA ME). A basal cell carcinoma is shown in the right figure. The same lesion is treated with 5-ALA ME and 3 hrs later exposed to blue light. Red fluorescence from protoporphyrin IX induced by 5-ALA ME in the lesion is shown on the left side. Prof. Dr. Petrich Biophotonics II (SS 2018) 30