A new in vivo Raman probe for enhanced applicability to the body.
This paper describes a new in vivo Raman probe that allows investigation of areas of the body that are otherwise difficult to access. It is coupled to a previously described commercially available in vivo Raman spectrometer that samples the skin through an optical flat. In the work  presented here, the laser light emerges from a smaller pen-shaped probe. It thus works on the same principles as the original spectrometer, while its relative performance in terms of signal-to-noise ratio of the spectra and obtained spatial resolution is only slightly diminished. It allows  the window to be placed against the subject in more curved and recessed areas of subject's body and also for them to be more comfortable while the measurements take place. Results from three areas of the body that have previously been very difficult to study are described, the mouth, axilla,  and scalp. Results from the scalp and axilla strata cornea (SC) show significant differences from the "normal" SC of the volar forearm. For instance, the scalp is observed to have lower amounts of natural moisturizing factors (NMF) compared to the volar forearm within the same  subjects. Also for both the axilla and scalp the lipids show a change in order as compared to the lipids in the volar forearm and also differences from each other. The potential significance of these observations is discussed. Further, we show how we can probe the mouth, in this case observing  the presence of the astringent tea polyphenol epigallocatechin gallate within the oral mucosa.
Unilever Discover, Colworth Laboratory, Sharnbrook, Bedfordshire, UK. paul.pudney@unilever.com
Paul D A
PD
Pudney
Eleanor Y M
EY
Bonnist
Peter J
PJ
Caspers
Jean-Philippe
JP
Gorce
Chris
C
Marriot
Gerwin J
GJ
Puppels
Scott
S
Singleton
Martin J G
MJ
van der Wolf
D000328:Adult; D001365:Axilla; D002392:Catechin / Q000031:analogs & derivatives / Q000032:analysis; D004817:Epidermis / Q000737:chemistry*; D004867:Equipment Design; D005260:Female; D005542:Forearm; D006801:Humans; D008055:Lipids / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000737:chemistry*; D009928:Organ Specificity; D012535:Scalp / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods; D055815:Young Adult
D008055:Lipids; D002392:Catechin; C045651:epigallocatechin gallate