Autologous platelet-rich plasma exosome quantification after two thermo-photobiomodulation protocols with different fluences

Objective

The study aimed to assess the effects on exosome quantification of thermo-photobiomodulation (TPBM) with blue light administered at two different fluences for preconditioning platelet-rich plasma (PRP).

Material and Methods

This was an in-vitro study aiming to compare the number of exosomes released from PRP samples after preconditioning for 10 min with blue light (467 nm) at two different fluences, 1.0 J/cm² and 2.0 J/cm², and controlled heating at 37 °C. PRP samples form three healthy donors were obtained after withdrawing 64 mL of blood and were preconditioned following the two protocols using the MCT System®, a TPBM device with different energy, wavelength, temperature, and time combinations settings. Samples were placed in the MCT Kit® during the procedure, a single-use class IIa device with specific optical properties to optimize light scattering and transmittance. Exosomes were isolated by ultracentrifugation and quantified in triplicate using Nanoparticle Tracking Analysis (NTA).

Results

The mean exosome concentration was 2.99 × 10¹¹ particles/mL (SD 1.31 × 10¹¹) for the samples exposed to 1.0 J/cm² and 2.53 × 10¹¹ particles/mL (SD 1.39 × 10¹¹) for the samples exposed to 2.0 J/cm² (p = 0.0262). The lower light fluence resulted in a 15.4 % increase in exosome concentration compared to the highest one.

Conclusions

Different light fluences during the PRP preconditioning resulted in varying exosome concentrations, with the lowest fluence producing the highest yield. Further research is required to determine whether other fluences can improve outcomes and identify the most suitable preconditioning protocol.