The temperature dose
It is well known that temperature has different actions on organisms, tissues, and cells. Thermobiomodulation1 (TBM) or Thermal-boosting (TB) is a completely new concept, though very easy to understand. Basically, it means that biological activity can be modulated by temperature, which is the same that happens with photobiomodulation (PBM), but with heat and/or cold instead of light. TBM contributes to several biological processes such as vasodilation, rheological properties alteration, or platelet kinetics modification, among many others.
As regards the energy involved in TBM treatments, published articles have applied a diverse range of temperatures on cells, with results showing that various cell types may respond differently to temperature. Currently, there is already pre-established knowledge that TBM therapy may achieve promising results in PRP treatments. Several studies are already aiming to optimize PRP protocols, and some authors have contrasted and evaluated different optimizing strategies, such as dilution, preincubation at 4 °C, and plasma cryoprecipitate supplementation, by analyzing PRP angiogenic and regenerative properties.2
How temperature affects PRP
These studies set the basis for PRP TBM at 4 °C and reached important conclusions, including the fact that though PRP is usually processed at 37 °C or at room temperature (20 °C – 25 °C), it is traditionally known that lower temperatures prime platelet activation and trigger the release of alpha granules.2 Some authors observed that the release of VEGF, EGF, and bFGF (but not PDGF) was significantly increased when PRP was incubated at 4 °C before inducing coagulation2 and others, that this release took place in a much more physiological way.3
Few studies have addressed the TBM issue, but those that have, reported consistent results, achieving, for example, statistically significant different concentrations of EGF, FGFb and VEGF before and after TBM protocols.1 Other groups went even further and concluded that TBM was a novel and convenient method for the preparation and activation of PRP without any additives and that, when compared to standard PRP, thermoactivated PRP showed more physiological characteristics while maintaining high quality.3
As with any other form of technology-based treatments, there is a lot of physics behind any effective TBM device. There are some hidden variables of maximum importance that have proved to be critical in the past and are beyond the control of the physician. This is the case, for example, of cooling speed.4
There are no comprehensive studies analyzing the change of effects that occur in TBM when parameters are tweaked individually. This considerable level of complexity means that the choice of parameters often depends on the practitioner’s personal preference or experience rather than on a consensus by an authoritative body. Still, dosimetry in TBM is not complicated.