Silver sulfide nanoparticles to advance in the diagnosis of eye diseases

A study published in the journal Small and developed by researchers from the Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC) in collaboration with the group of Drs. Enrique J. de la Rosa and Catalina Hernández at the Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC) present the development of a new type of probe that uses nanomaterials to facilitate the diagnosis of diseases affecting the eyes.

To create these probes, the researchers have used silver sulfide nanoparticles, which emit light in the infrared range (i.e., they are luminescent). These sensors, applied to the optical coherence tomography (OCT) technique, a widespread and robust method for diagnosing eye diseases, act in a dual way: they behave as contrast agents in OCT and also allow high-resolution luminescence infrared images of the inside of the eye to be obtained. Beatriz H. Juárez, a scientist at the ICMM-CSIC and one of the main authors of the study, points out that this dual function of nanoparticles "facilitates the development of new methods for diagnosing eye diseases".

This is due to the improvement in the quality of diagnostic images associated with the ability of the probes to "emit a very bright light capable of passing through tissues and a high light-scattering power," explains Emma Martín Rodríguez, a researcher at the Universidad Autónoma de Madrid and co-lead author of the study. These results have been possible thanks to the use of a type of biocompatible polymeric material "that surrounds the surface of the nanoparticles, controls the size of the probes, and provides a protective layer that preserves the infrared light-emitting properties of the nanoparticles," explains ICMM-CSIC researcher Amalia Coro.

The work carried out on mouse models, is an example of interdisciplinary research that has involved the coordination of chemists, physicists, biologists, and biotechnologists from the CSIC, the Universidad Autónoma de Madrid (UAM), the CIC-biomaGUNE (Biomaterials Cooperative Research Center Association) and the IMDEA Nanoscience Foundation.

"By expanding the possibilities of OCT, our research could have a significant impact on diagnosis, as well as facilitating the monitoring of the therapeutic potential of new treatments for retinal diseases," concludes Enrique J. de la Rosa, a researcher at CIB-CSIC.

Reference: Ag2S Biocompatible Ensembles as Dual OCT Contrast Agents and NIR Ocular Imaging Probes. Coro, A. Herrero Ruiz, M. Pazo‐González, A. Sánchez‐Cruz, T. Busch, A. Hernández Medel, E. C. Ximendes, D. H. Ortgies, R. López‐Méndez, A. Espinosa, D. Jimenez de Aberasturi, D. Jaque, N. F. Monsalve, E. J. de la Rosa, C. Hernández‐Sánchez, E. Martín Rodríguez, B. H. Juárez (2023) Small. DOI: 10.1002/smll.202305026

More information:

CSIC Press release (in Spanish): link.