PEG-PLGA from PolySciTech used in quantitative analysis of fluorescent dye performance with varying nanoparticle loads.

 

Due to their chemical structure, fluorescent molecules have the ability to absorb light of a certain wavelength and emit light at a lower frequency (longer wavelength). This phenomenon is widely used in assays and imaging applications for example fluorescent labelling of certain molecules or items to more easily visualize them under microscope or use of near-infrared dyes which can penetrate through skin and muscle allowing imaging the location of particles or other items within a living organism. Recently, researchers at University of Queensland used mPEG-PLGA (AK026) from PolySciTech (www.polyscitech.com) to quantitatively test the fluorescence of dye loaded inside of pegylated nanoparticles and compare these results to other kinds of dye-loaded nanoparticles. Depending on the dye’s access to other dye molecules (which can reduce fluorescence due to self-quenching) and also the presence of items which may prevent the light from passing through the fluorescence intensity may be drastically altered. This research provides important fundamental understanding to dye-particle performance to optimize tracking studies and theranostic applications. Read more: Yang, Guangze, Yun Liu, and Chun-Xia Zhao. "Quantitative comparison of different fluorescent dye-loaded nanoparticles." Colloids and Surfaces B: Biointerfaces (2021): 111923. https://www.sciencedirect.com/science/article/pii/S0927776521003672

“Highlights: Many factors affect fluorescence intensity of dye-labeled NP at the same dye loading. These factors include dye distribution inside or on the surface of NP, and material shielding. A more reliable method was proposed to compare NP cell uptake. Abstract: Labeling nanoparticles with fluorescent dyes is a common approach to investigate their cell uptake and biodistribution, providing valuable information for the preclinical assessment of nanoparticles for drug delivery. However, the underlying assumption that the fluorescence intensity of dye-labeled nanoparticles correlates positively with the amount of nanoparticles taken up by cells might not be valid under some conditions, as it can be affected by many factors including dye dispersion, dye quenching, and material shading. Here we demonstrated that both nanoparticles with hydrophobic dyes encapsulated inside and nanoparticles with hydrophilic dyes conjugated on the particle surface suffer from different degrees of dye quenching, making it challenging for quantitative comparison of cell uptake of different nanoparticles. To address this challenge, we proposed a possible solution for direct comparative studies of dye-labeled nanoparticles. This work provides valuable information for designing and evaluating different nanoparticles for drug delivery applications.”