Photochemistry at UJI

Photochemistry Research Group
at Universitat Jaume I (Castellon, Spain)

Research lines

Our current projects are focused on the preparation of structures capable of reaching the mitochondria on living cells, specially cancerous ones, and be able to detect them by confocal microscopy. Once in the mitochondria, a double goal is pursued: detecting species of biochemical interest by fluorescence and/or eliminating undesired cells using light (mitochondrial PDT).

In relation to this topic, we also develop small-molecule photosensitizers as photo-antimicrobials, with a particular focus on drug-resistant strains responsible for hospital-acquired infections.

Another line of interest is the preparation of polymeric materials with photo-antimicrobial properties, in order to prevent microbial contamination by oportunistic pathogens (fungal and bacterial).

Molecular probes for cell imaging

We have developed small fluorescent organic molecules for the analysis of cellular organelles, such as lysosomes and mitochondria. In addition, we have achieved the detection of reactive species within these organelles—for example, nitric oxide (NO), in cancer cells. Our interest lies in developing improved carriers for targeted delivery to mitochondria and the visualization of NO and other reactive nitrogen species (RNS) by confocal microscopy. Knowledge of the roles of RNS in mitochondria could be leveraged to develop diagnostic methodologies based on the imbalance of these species associated with pathological conditions.

Photodynamic therapy of cancer

Another line of research involves the preparation and study of organic photosensitizers targeted to the mitochondria of cancer cells. There, the photoinduced generation of reactive oxygen species (ROS) is promoted, leading to the destruction of malignant cells. The use of photosensitizers operating in the near-infrared (NIR) region is an important objective, as it enables deeper light penetration into tissues. In addition, alternative mechanisms to type II PDT are currently under investigation.

Antimicrobial photodynamic inactivation

The same principles applied to PDT for cancer can also be used for the destruction of microbial pathogens. We are investigating several cationic organic compounds capable of eradicating cultures of Gram-positive and Gram-negative bacteria, as well as fungi, upon light irradiation. The emergence of antibiotic-resistant microorganisms in recent years makes this line of work an important avenue for future research.

Photo-sterilisable materials

This area of research focuses on the preparation of styrenic and acrylic polymers with photoactive properties. The photoinduced generation of singlet oxygen on the surface of these materials makes them promising candidates for the fabrication of photo-sterilizable objects, ranging from prostheses and catheters to coatings for everyday items. In connection with the previous line, contagion in hospital settings is becoming a major problem; therefore, pathogen-free surfaces will become an increasingly important property in the near future.