Light delivery and monitoring during photodynamic therapy (PDT) is often limited by the need for a physical link between the light source, detectors and the treatment volume. This paper reports on the first in vivo experiments performed with a fully implantable telemetric system, designed for a rat glioblastoma model. In this system, light delivery is performed using a solid state optode containing 2 LEDs, and 4 photodiodes which will be used to monitor light delivery in future experiments. Powering and communication is achieved by means of an inductive link. The implant may remain in the animal for extended time periods, making it particularly interesting for performing metronomic PDT. In this paper, we demonstrate the feasibility of in vivo light delivery and biocompatibility of the device.. Activation of the inductive link as well as illumination of the brain by the LED did not influence animal behavior during or after treatment. We show that the implant can remain in the animal for two weeks without causing serious biological reactions.

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Photodynamic therapy (PDT) is a growing treatment modality for various diseases, most notably cancer. It has several advantages compared to radiotherapy and chemotherapy, but a good dosimetry is very important for an efficient treatment. One of the key parameters in PDT dosimetry is oxygen availability in tissue, which can be measured making use of spectroscopic techniques. For this purpose, a broadband source is needed to illuminate the volume of interest at all wavelengths necessary for the spectroscopic information. In an implantable system under development, this broadband source is being implemented as a microfabricated lamp. In this paper we report on the characterisation of a tungsten microheater as the incandescent filament, showing that this type of element can be brought to emit significant radiation in the wavelength range of interest.

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The impact of environmental pollution on climate change has necessitated the development of highly efficient gas sensors. Among the various sensing materials, metal oxides have shown great potential for gas sensing applications. However, the quest for highly efficient room-temperature gas sensors is ongoing. In this study, we present an approach for the fabrication of nanospheres from bulk TiO2 using the template-free pulsed laser ablation technique in liquids. The obtained nanoparticles were comprehensively characterized using X-ray diffraction, Raman analysis, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible (UV–vis) spectroscopy, and photoluminescence (PL) studies to evaluate their structural, morphological, and optical properties. The room-temperature gas sensing performance of the fabricated TiO2 nanospheres (NTO) was evaluated using clad-modified fiber optic gas sensors for various gas concentrations. Remarkably, the NTO gas sensor exhibited interesting results, where the performance of NTO was twice that of its bulk counterpart, indicating its suitability for highly efficient gas sensing applications. Additionally, a theoretical calculation of light modulation through optical fibers was presented, providing insights into the sensing mechanism. Our findings demonstrate the potential of pulsed laser ablation in liquids for developing highly efficient room-temperature gas sensors for environmental monitoring applications.