Does platelet lysate switch cryopreserved human tissues on?

Platelet lysate is a derivative of platelet-rich plasma that is used as supplement for in vitro cell culture media. A variety of protocols for its preparation have been described. However, its potential use in the clinical setting has been poorly studied. In the present work, the effect of several protocols on cell proliferation has been comparatively analyzed. Additionally, the effect of exposing bone and vascular tissues to different concentrations of platelet lysate has also been analyzed. Human fibroblast-like cells were used to test preparation protocols. Thawed skull and artery fragments were incubated with platelet lysate and seeded as explants in culture plates. Cell growth was evaluated quantitatively in the first assay (cell count) and qualitatively in the second (presence of growing cell colonies). The presence of leukocytes in the raw material to obtain the platelet lysate was correlated with higher cell proliferation. In all cultures from arteries and 71.4% of those from bones, the presence of viable cells was detected. No statistically significant differences that correlated with the percentage of platelet lysate used during the post-thaw incubation were observed. The main findings of this study revealed that: there is a contribution of bioactive substances for cell growth by lymphocytes, incubation with platelet lysate had no significant activating effect on cells in thawed tissues, arteries stored in liquid nitrogen retained cell viability for long periods (over 5 years), and cell viability in bones stored at - 80 °C decreased after 3 months.