The in vitro application of high-intensity laser therapy on equine platelet-rich plasma and autologous protein solution does not alter select cytokine and growth factor concentrations.

Overview

• This study investigated whether applying high-intensity laser therapy (HILT) to equine platelet-rich plasma (PRP) and autologous protein solution (APS) in vitro would change the levels of specific cytokines and growth factors involved in immunomodulation and tissue healing.
• The researchers found that HILT did not significantly affect the concentrations of these molecules, suggesting that this laser treatment neither enhances nor diminishes their release in the blood-derived products tested.

Background and Purpose

• Equine PRP and APS are blood-derived orthobiologic products used to promote healing, especially in soft tissue injuries.
• These products contain key cytokines (like TGF-β1) and growth factors (like PDGF-BB) that modulate inflammation and tissue repair.
• High-intensity laser therapy (HILT) is a treatment modality that has potential regenerative benefits, but its effects on the release or concentration of these bioactive molecules in PRP and APS are unclear.
• The study aimed to determine if HILT could alter the concentration of such molecules, potentially enhancing the therapeutic efficacy of PRP and APS when used together.

Methodology

• Six adult horses provided whole blood samples, collected under controlled conditions at the University of Pennsylvania.
• Blood was processed into two orthobiologic preparations:
  • Platelet-rich plasma (PRP)
  • Autologous protein solution (APS)
• The PRP and APS samples were split into two groups:
  • Control group (no laser exposure)
  • HILT-exposed group
• HILT was applied using a Class IV laser with these parameters:
  • Wavelength: 1064 nm (infrared)
  • Mean power output: 20 watts
  • Pulse energy: 1,300 millijoules
  • Pulse duration: 65 milliseconds
  • Frequency: 10 Hz
  • Application time: 10 seconds per sample
• After treatment (and a freeze-thaw cycle), concentrations of key cytokines and growth factors were measured using:
  • Multiplex bead-based immunoassays
  • ELISA (enzyme-linked immunosorbent assay)

Results

• No significant changes were observed in the levels of tested cytokines and growth factors between control and HILT-treated samples.
• This indicates that HILT under the specific parameters used does not modulate the release or degradation of key immunomodulatory proteins in PRP or APS in vitro.

Interpretation and Implications

• The findings suggest that combining HILT with PRP or APS in a clinical setting would not inherently alter the concentration of potentially therapeutic cytokines and growth factors in these blood products.
• This lack of modulation could mean that any therapeutic benefit of HILT combined with blood orthobiologics in treating equine soft tissue injuries may come from mechanisms other than altering cytokine/growth factor levels in the products themselves.
• Understanding this interaction helps veterinarians and researchers rationally design combined treatment protocols, knowing that HILT does not compromise or enhance the bioactive content of PRP and APS prior to administration.
• Future research could explore other dosages, durations, or clinical applications to see if different HILT parameters or in vivo conditions affect cytokine release differently.

Conclusion

• High-intensity laser therapy, applied in vitro to equine platelet-rich plasma and autologous protein solution, does not alter the concentration of selected immunomodulatory cytokines and growth factors.
• These results contribute valuable knowledge for the integration of laser therapy with blood-based orthobiologics in equine medicine, supporting evidence-based approaches for treating soft tissue injuries.