Absorbance measurements at the tympanic membrane

Inflammation in connection to implants can result in biofilm formation at the surface of the implants. This in turn can lead explantation due to medical reasons. To prevent this loss of implants, antibacterial photodynamic therapy (aPDT) is currently investigated for possible coatings of the implant surface. Antibacterial properties could then be switched on by illumination with light. As the tympanic membrane (TM) is semitransparent, absorbance characteristics of the TM was investigated at different wavelengths in the current study.

Firstly, experimental conditions were established before tympanic membranes of young (p3-5) and adult rats were measured. Additionally, few human samples were investigated at wavelengths between 300 and 900 nm. A mainly continuous decrease in absorbance was measured with increasing wavelengths. Two local maxima were found at 420 nm and smaller but broader in the range of 540/580 nm. At larger wavelengths, about 10 %  of the light was transmitted in TM of young rats whereas only about 1 %  was transmitted through TM of adult rats. In humans, results varied between 1 and 10 % . Whether this would be enough to activate aPDT on implant surfaces through the TM remains to be investigated in future studies.

Poster-PDF A-1460.pdf

BMBF RESPONSE 03ZZ0914D

Publication History

Article published online:
13 May 2021