Author(s): Fernandes, Filipa Gracinda Silva ; Pereira, Mário R. ; Soares, Delfim ; Fonseca, A. M. ; Costa, Daniel ; Silva, Filipe Samuel ; Sousa, Nuno ; Catarino, Susana Oliveira ; Carvalho, Óscar Samuel Novais
Date: 2024
Persistent ID: https://hdl.handle.net/1822/93385
Origin: RepositóriUM - Universidade do Minho
Subject(s): Biological organs; Laser ablation; Light propagation; Muscle; Phantoms; TiO2 nanoparticles; Tissue engineering; Titanium dioxide
Searching for materials that accurately mimic the optical properties of biological tissues is essential, particularly for transcranial photobiomodulation (PBM) research, where it is necessary to comprehend how light propagates through the head tissues. In this research, we characterised, in the 500-1200 nm range, the transmittance spectra of porcine tissues (skin, muscle, cranium, brain, and cerebellum) and different agarose-based phantoms. These phantoms were developed using different combinations of titanium dioxide (TiO2), India ink, organometallic compounds, and laser-ablated gold and zinc oxide nanoparticles. The surface and mechanical properties of these phantoms were also characterized. The results showed that an increased TiO2 concentration decreased the optical transmittance of the phantoms. However, when TiO2 was added to the India ink and laser-ablated nanoparticles phantoms, not only did it reduce transmittance amplitude, but it also flattened its spectra. Comparing the phantoms and biological tissues results, the spectral profiles of TiO2 samples appeared similar to those of muscle, skin, and brain/cerebellum; organometallic compounds replicated the skin and muscle curves; India ink emulated skin and cranium; and the laser-ablated nanoparticles mimicked the muscle. Although it was possible to establish qualitative similarities between the phantoms and the biological tissues optical transmittance spectra, there is a need for further studies with different components combinations to ascertain curves that more closely mimic the biological tissues. © 2024 The Royal Society of Chemistry.
