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van Haasterecht L, Zhou M, Ma Y, Bartolini L, Van Mourik F, Van Zuijlen PPM, Groot ML. Visualizing dynamic three-dimensional changes of human reticular dermal collagen under mechanical strain. Biomed Phys Eng Express 2023; 9:035033. [PMID: 37054703 DOI: 10.1088/2057-1976/accc8e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 04/13/2023] [Indexed: 04/15/2023]
Abstract
In clinical practice, plastic surgeons are often faced with large skin defects that are difficult to close primarily. Management of large skin wounds e.g. burns or traumatic lacerations requires knowledge of skin biomechanic properties. Research into skin microstructural adaptation to mechanical deformation has only been performed using static regimes due to technical limitations. Here, we combine uniaxial stretch tests with fast second harmonic generation imaging and we apply this for the first time to investigate dynamic collagen rearrangement in reticular human dermis.Ex vivohuman skin from the abdomen and upper thigh was simultaneously uniaxially stretched while either periodically visualizing 3D reorganization, or visualizing 2D changes in real time. We determined collagen alignment via orientation indices and found pronounced variability across samples. Comparing mean orientation indices at the different stages of the stress strain curves (toe, heel, linear) showed a significant increase in collagen alignment during the linear part of the mechanical response. We conclude that fast SHG imaging during uni-axial extension is a promising research tool for future studies on skin biomechanic properties.
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Affiliation(s)
- L van Haasterecht
- LaserLab Amsterdam, Department of Physics and Astronomy, Faculty of Sciences Vrije Universiteit, Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
- Amsterdam UMC, Vrije Universiteit, Department of Plastic, Reconstructive and Hand Surgery, Amsterdam Movement Sciences, PO Box 7057, 1007 MB Amsterdam, The Netherlands
- Burn Center, Red Cross Hospital, PO Box 1074, 1940 EB Beverwijk, The Netherlands
| | - M Zhou
- LaserLab Amsterdam, Department of Physics and Astronomy, Faculty of Sciences Vrije Universiteit, Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Y Ma
- LaserLab Amsterdam, Department of Physics and Astronomy, Faculty of Sciences Vrije Universiteit, Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - L Bartolini
- LaserLab Amsterdam, Department of Physics and Astronomy, Faculty of Sciences Vrije Universiteit, Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - F Van Mourik
- LaserLab Amsterdam, Department of Physics and Astronomy, Faculty of Sciences Vrije Universiteit, Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - P P M Van Zuijlen
- Amsterdam UMC, Vrije Universiteit, Department of Plastic, Reconstructive and Hand Surgery, Amsterdam Movement Sciences, PO Box 7057, 1007 MB Amsterdam, The Netherlands
- Burn Center, Red Cross Hospital, PO Box 1074, 1940 EB Beverwijk, The Netherlands
| | - M L Groot
- LaserLab Amsterdam, Department of Physics and Astronomy, Faculty of Sciences Vrije Universiteit, Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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Carbone F, Aubock G, Cannizzo A, Van Mourik F, Nair R, Geim A, Novoselov K, Chergui M. Femtosecond carrier dynamics in bulk graphite and graphene paper. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.01.052] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Van Brederode ME, Jones MR, Van Mourik F, Van Stokkum IH, Van Grondelle R. A new pathway for transmembrane electron transfer in photosynthetic reaction centers of Rhodobacter sphaeroides not involving the excited special pair. Biochemistry 1997; 36:6855-61. [PMID: 9188680 DOI: 10.1021/bi9703756] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
It is generally accepted that electron transfer in bacterial photosynthesis is driven by the first singlet excited state of a special pair of bacteriochlorophylls (P*). We have examined the first steps of electron transfer in a mutant of the Rhodobacter sphaeroides reaction center in which charge separation from P* is dramatically slowed down. The results provide for the first time clear evidence that excitation of the monomeric bacteriochlorophyll in the active branch of the reaction center (B(A)) drives ultrafast transmembrane electron transfer without the involvement of P*, demonstrating a new and efficient mechanism for solar energy transduction in photosynthesis. The most abundant charge-separated intermediate state probably is P+B(A)-, which is formed within 200 fs from B(A)* and decays with a lifetime of 6.5 ps into P+H(A)-. We also see evidence for the involvement of a B(A)+H(A)- state in the alternative pathway.
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Affiliation(s)
- M E Van Brederode
- Department of Physics and Astronomy, Free University of Amsterdam, The Netherlands.
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