Synthesis and functionalization of silica-based nanoparticles with fluorescent biocompounds extracted from Eysenhardtia polystachya for biological applications.

Several types of dyes or fluorophores are used for the detection of interactions between drug carriers and cells, within biomedicine field. However, many of them have a certain level of toxicity and instability affecting their biological properties. Different studies have demonstrated that nanoparticles (NPs) have interesting properties that could be used to stabilize diverse biomolecules, including dyes. Here, we report the synthesis of a novel nanosystem by the functionalization of silica NPs using biocompounds extracted from Mexican tree "Palo azul" (Eysenhardtia polystachya) and APTES as a coupling agent. Particle size, electrical properties, and morphology of the novel nanosystem were analyzed. The extracted biocompounds presented fluorescence which prevails over time, even after nanosystem formation and apparent cellular internalization. These were detected using MCF-7 cells visualized by confocal laser-scanning microscopy (CLSM), finding that the nanosystem was able to internalize into cells and act as a fluorescent biomarker. By this method, our novel nanosystem opens the possibilities to obtain sensitive data in a noninvasive manner for biological applications, such as early-stage cancer diagnosis, drug delivery, and pathogen detection.