# Industrial Mass Production of Platelet Dry Powder
## 4 Discussion
Calcium chloride is generally lower cost than collagen and thrombin, which are quite expensive. Different requirements will also determine which activator is chosen. For example, activators that can rapidly release TGF-\(\beta\)1 in large amounts may be prioritized in applications to promote bone repair, while activators that assist with the steady release of PDGF and KGF may be preferred in hair follicle regeneration. Furthermore, the dosage form may also influence the activator choice, as the efficacy and adaptability of the activator must also be considered when creating a gel dosage form used to dress wounds or liquid dosage form to spray on skin. Calcium chloride solution was selected as the activator in this study because of its lower cost and ability to induce the formation of natural thrombin, thus simulating the physiological process and the sustained release of GFs. Sustained GF release is critical to ensuring proper tissue repair and wound healing. However, in the future, different activator combinations may be considered according to the GFs and applications involved. In common PRP applications, the activation of platelets [12; 14; 15; 17; 20; 24] is seen as a vital step in the release of GFs, which play a key role in cell proliferation, migration, and differentiation. The activation process is dependent on the use of specific activators, which are commonly thrombin, collagen, and calcium chloride solution [5; 6; 17]. Platelets contain three primary granule types: \(\alpha\) granules, dense granules, and lysosomes [6; 7; 8]; each granule stores different bioactive substances. When platelets are activated through the direct addition of these activators, GFs and other bioactive substances stored in these granules are released [5; 17; 18; 19]. During the activation process, these granules will release their bioactive substances and thus induce biological responses such as platelet aggregation, proliferation, and cell migration. The direct addition of an activator to activate PRP will alter the structure of fibrinogen into a 3D fibrin structure, converting fibrinogen into fibrin gel [5; 8; 17; 18]. This gel structure not only acts as a GF carrier, it also provides a microenvironment with controlled release properties, allowing the GF to be released when and where needed. However, in the mass-production of PRP, ensuring that all the completed PRP has been transformed into fibrin gel is incredibly difficult and time-intensive; furthermore, partial transformation of the platelet solution into fibrin gel will compromise the concentration and quality of the resulting platelet dry powder. Therefore, preventing the formation of fibrin gel is crucial in mass-production processes. In this study, platelet activation through the indirect addition of calcium chloride solution both enhanced the release of GF and minimized the formation of fibrin gel, ensuring that the concentration and quality of the prepared platelet dry powder was up to standard. In regenerative medicine research, PRP and PRF applications are primarily centered around autologous use [14; 15; 16]. However, given the limitations of human autologous blood, large-scale mass-production is rife with difficulties. In contrast, pig blood as the source for preparing platelet dry powder guarantees a steady supply that is easy to obtain and relatively low-cost, making it the foremost choice for the mass-production of platelet dry powder. Moreover, given the widespread use of pigs in biomedical research, our profound understanding of their physiological and hematological properties provides a solid foundation for their use in regenerative medicine.