Background: Platelets play an important role during the inflammatory phase of wound healing due to the release of growth factors. They also have antimicrobial peptides which contribute to their antimicrobial properties. These features make platelet-derived products suitable biological therapies specifically against bacterial infections. Hypothesis: Canine platelet lysate will display antimicrobial impacts against common bacteria found in canine skin wounds, while the leukocyte concentration, presence of plasma and complement will affect this antimicrobial activity. Animals: Blood was collected from nine purpose-bred dogs.
Methods: Platelet-rich plasma was generated using both leukocyte-reduced and leukocyte-rich centrifugation methods, while a portion of the formulations were depleted from plasma while others underwent complement inactivation via heat. The antimicrobial activity of the above formulation was tested against (ADD bacteria) using a bacteria spiking assay.
Results: After 3 hours, platelet lysate showed a statistically significant reduction in E. coli and S. aureus bacteria cultures. No significant differences were observed between leukocyte-rich and leukocyte-reduced lysate formulation. Plasma depletion increased the growth of S. pseud but reduced the growth of E. faecalis after 3 hours In comparison to platelet lysate, E. faecalis growth was significantly higher due to heat-induced deactivation of plasma complement proteins after 24 hours. Conclusions and Clinical Importance: Complement proteins and plasma are critical for inhibiting the growth of some bacterial strains although leukocyte concentration does not appear to affect this activity. These findings highlight the potential of platelet lysate to be used as an antibiotic substitute or supplement for clinical use.
