1. Quantifying the inhibition of EV release from astrocytoma cells
Photodynamic light therapy is a promising treatment for aggressive brain tumours, including astrocytoma. This in vitro study showed that photodynamic light therapy (PDT) paired with the photosensitiser Rose Bengal treatment-induced toxicity in astrocytoma cells, but not in healthy astrocytes. This was enhanced by amino acid starvation, but astrocytoma cell elimination of Rose Bengal limited effectiveness.
The mechanism of Rose Bengal elimination was found to be facilitated via EVs. The authors next used GW4869 to pharmacologically inhibit EV release from astrocytoma cells, which – when combined with Rose Bengal treatment, PDT and amino acid starvation – effectively induced cell death. Using this combined protocol, healthy astrocyte viability was not significantly impacted upon. TRPS was used in this study to confirm dose-dependent decrease in EV release with increased concentrations of GW4869.1
2. Size profiling of EVs loaded with albumin-bound curcumin
EVs from a mouse cell line were loaded with albumin and subsequently with curcumin in an attempt to stabilise curcumin for therapeutic uses. TRPS was used to measure the size distribution of these modified EVs as compared to ‘naïve’ EVs. Application of these albumin-bound curcumin EVs using dissolvable microneedle arrays or intradermal injection improved the skin lesions of rats with a model of psoriasis and induced better disease resolution than with curcumin alone.2
3. Sizing and quantification of EVs in a comparative methods study
In this study by Visan et al (2022), size-exclusion chromatography-based qEV columns were paired with pre-processing by either ultracentrifugation or tangential flow filtration. Three machines using two techniques between them were also compared for the analysis of these particles: TRPS using the qNano or nanoparticle tracking analysis (NTA) on two different machines. TRPS appeared to be superior for the analysis of particles <100 nm, with two NTA machines unable to measure a large proportion of the <100 nm particles which were quantified using TRPS. TRPS was also able to confirm that tangential flow filtration increased the yield of small EVs subsequently isolated using qEV columns as compared to ultracentrifugation.3
4. Size profiling of plasma EVs in women with preeclampsia
This study by Chen et al (2022) recruited women prospectively in early pregnancy and sampled plasma in the first, second and third trimesters. Of these women, 39 developed preeclampsia and 127 women remained healthy during pregnancy. Plasma EVs were isolated using size-exclusion chromatography-based qEV columns and were subsequently analysed using ELISA and TRPS, the latter showing slightly different size profiles and concentration in preeclamptic women compared to healthy controls. Cross validating various models based on significantly altered cytokines and EV concentration identified that plasma placental-derived EV (marked by PLAP) concentration combined with EV TGF-β had an accuracy of 90% for the prediction of preeclampsia development.4
