# Industrial Mass Production of Platelet Dry Powder
## 4 Discussion  
Industrial mass-production of platelet dry powder was performed with pig blood. The centrifuge used in this study can process over 300 L of pig blood per hour, yielding large amounts of wet powder that was freeze-dried into platelet dry powder. The experimental  
Figure 5: Reproducibility across different batches, showing the GF concentrations of 6 batches of platelet dry powder prepared with the same conditions. (**a**) depicts a mean TGF-\(\beta\)1 concentration of 129,080 pg/mL; (**b**) shows the mean PDGF-BB concentration to be 81,173 pg/mL. Variation between batches is not substantial, demonstrating the stability of the preparation process and the repeatability of the experiment. Figure 6: Shelf-life testing. results indicate that the addition of calcium chloride solutions at different concentrations did not result in significant differences in platelet concentrations among the respective concentrations. Similarly, when different percentages of calcium chloride solutions were added, no noticeable variations in platelet concentrations were observed among the respective percentages. These findings suggest that, under the conditions of these experiments, the concentration and percentages of calcium chloride do not exert a discernible influence on platelet quantity. However, in contrast to platelet concentration, the results clearly demonstrate a pronounced impact of different concentrations and percentages of calcium chloride solutions on TGF-\(\beta\)1 and PDGF-BB concentrations. This highlights the significance of calcium chloride in influencing the release of growth factors, potentially impacting subsequent applications. Therefore, when utilizing calcium chloride solutions, careful regulation of TGF-\(\beta\)1 and PDGF-BB is crucial, in addition to monitoring platelet concentration, to ensure the accuracy and effectiveness of platelet dry powder applications. GF testing of the sterilized platelet dry power showed TGF-\(\beta\)1 concentrations over 100,000 pg/mL and PDGF-BB concentrations over 80,000 pg/mL, demonstrating that our method of preparing platelet dry powder is both high yield and high quality. Furthermore, our proposed method circumvents the risk of coagulated blood in the preparation of PRF without the use of anti-coagulants [12; 13] and the need for the careful extraction of platelets in the preparation of PRP [9; 10; 11], saving time and preventing human error. The two GFs tested in this study were TGF-\(\beta\)1 and PDGF-BB; however, the lesser availability of GF detection reagents for pig models than for human or mouse models has limited our comprehension and evaluation of the various GF contents in platelet dry powder prepared with pig blood to some extent. During the preparation of platelet products, the activation of platelets [14; 20; 21] is a vital step. There are many ways of activating platelets, including the addition of activators, the cyclical freezing and thawing of platelets, and the use of ultrasound techniques [22]. The addition of activators is broadly considered to be a more efficient method of activation, and common activators include thrombin, collagen, and calcium chloride solution [17; 22]. As the platelet dry powder can be prepared in various dosage forms for human use, when selecting an activator, its associated risks must also be considered. Thrombin may be a common option, but most thrombin products are derived from bovine thrombin, which is costly and holds certain risks that cannot be ignored. The use of exogenous bovine thrombin may trigger immune responses and allergic reactions in patients [6; 22; 23; 24]. The use of thrombin from either homologous or xenogenic sources in this procedure carries substantial risks. These forms of thrombin, derived from either genetically similar or distinct species, have the potential to induce allergic reactions in patients.