Quantification and Characterisation of Nano-Sized Particles in Cryoprecipitate Units

Background

Cryoprecipitate is an important blood product derived from fresh frozen plasma. It is primarily used to replenish fibrinogen levels in patients. Currently, there is a lack of studies characterising nano-sized particles, including extracellular vesicles (EVs) in cryoprecipitate. EVs play a key role in cell-to-cell communication in physiological and pathological conditions, through the transference of their bioactive cargo such as proteins, lipids, or nucleic acids. This study utilised modern techniques such as nanoparticle tracking analysis (NTA) to characterise these EVs.

Methods

We obtained ten individual cryoprecipitate units and determined their particle concentration and size distribution using optimised NTA parameters on the Nanosight NS300 instrument.

To prevent blockage of the Nanosight's micro-fluidics, samples are routinely filtered before sample injection. Therefore, we wanted to investigate if different filter materials could impact NTA measurements for cryoprecipitate. Samples were filtered with either regenerated cellulose (RC) or polytetrafluoroethylene (PTFE), with non-filtered samples as control. A one-way ANOVA with Tukey post hoc test was used to compare the particle parameters (particle concentration, mean, mode). Significance was set at p<0.05.

Results

The results showed that different cryoprecipitate units varied in their particle concentration and size, with an average concentration of 2.501 x 10 ¹¹ ± 1.098 x 10 ¹¹ particles per mL and a particle mean of 133.8 ± 7.5 nm and mode of 107.9 ±11.06 nm. In addition, only samples filtered using RC were there no significant changes in the measured particle parameters (particle concentration, p=0.936; mean, p=0.999; mode, p=0.996) compared to the non-filtered samples. A significant difference was observed in the mean of particle size between PTFE and RC filters (112.7 ± 6.033 nm, 42 133.8 ± 7.503 nm, p =<0.0001) and between PTFE and non-filtered (112.7 ± 6.033 nm, 133.7 ± 13.63 nm, p =0.0015). PTFE significantly reduced the particle mean compared to both RC and non-filtered.

Conclusions

Our findings revealed that NTA could be used as a novel method to measure particles in cryoprecipitate. Furthermore, RC filters are compatible with quantitative NTA analysis compared to PTFE filters.