Thanks for joining me today to talk about getting more bang for your buck on regenerative PRP injections. Let's get to it!
What is PRP?
PRP consists of a concentrated solution of platelets, growth factors, signaling molecules, and other plasma proteins that play vital roles in orchestrating tissue healing and joint stabilization. The body’s natural response to an injury is to send platelets from the blood to the damaged tissues, which initiates the natural healing process. Platelets store a vast array of growth factors, which are released at the site of injury. Through cell signaling, the platelets call for other healing factors to be drawn into the site of injury. PRP can be injected into soft tissue injury sites or joints or even used for hair restoration and aesthetics. It is becoming more and more popular in regenerative medicine practices since it is quick, safe, and relieves pain while stimulating natural repair.
Improving PRP with Light
There are a couple of studies that indicate that PRP effects could be enhanced by using photobiomodulation (PBM), also called laser therapy or light therapy. Once blood is removed from the body, PBM applied to whole blood prior to the centrifuge process may "reversibly inhibit [platelet] activation...[there is] clear evidence of the PBM anti-aggregation effects. " The same study found that "Discontinuation of the PBM leads to the cessation of the effect on PLT aggregation....30–60 min from the end of PBM." Inhibiting platelet activation should lead to more intact platelets within the final PRP concentrate, "while no change in the total PLT count was observed." Since the effects are temporary, platelet activity probably has no lasting inhibition.
In theory, it is as if PBM puts the platelets into stasis for the centrifuge, separation, and injection stages, and then the platelets activate after they are injected into the target site.
Minimizing Red Blood Cell Damage Improves PRP
"High shear forces during specimen collection can liberate harmful hemolytic Hb components from disintegrating RBCs, leading to oxidative stress. " This also releases Platelet Activating Factor, leading to the premature action of platelets prior to injection. Macrophage Migration Inhibitory Factor is also released, which is a very potent inflammatory cytokine.
These Factors "might ultimately lead to secondary inflammatory conditions. In addition, the enormous MIF cytokine reservoir within RBCs are accountable for further increased levels of inflammation...physicians should choose the preparation method that safeguards the biologic." Separate research has shown that near-infrared "PBM limits RBCs lysis...cells subjected to NIR PBM were characterized by more excellent resistance to osmotic stress. "
Activating Platelets with Light
After the centrifuge and separation process, PBM can be used to enable "sustained growth factor release ." After applying light to the PRP, researchers observed that "ATP secretion and then, calcium release from platelets significantly increased...Photostimulation of platelets triggered lamellipodia extension, numerous filopodia formation, and platelet agglomeration as activation indicators. P-selectin expression was significantly increased after the application of PAC. In conclusion, PRP was successfully activated with [light] ... and realized activation-dependent sustained growth factor release during 28 days."
Clinical Application of Laser Therapy with PRP
Further research is needed prior to full adoption of PBM with PRP, and the following information is not our endorsement or recommendation for clinicians. But based on the current research, a protocol might look something like this in the future:
Step 1: Blood draw completed and specimens exposed to PBM. Parameters: 750–1100 nm, 1.5mW/cm2, 1 J/cm3 [1, 2, 4]
Step 2: After PRP solution is ready for injection, apply PBM again. Parameters: 600-1200 nm, 5mW/cm2, 0.5 - 10 J/cm2, [3, 5]
Step 3: Apply PBM in standard dosage to the region of the injection. Multitudes of studies have shown positive synergistic effects of PRP and PBM.
Much of this research is brand new and we are likely to learn more in the coming months and years. We'll update this blog post as that happens.
1. Walski, Tomasz et al. “Near-infrared photobiomodulation of blood reversibly inhibits platelet reactivity and reduces hemolysis.” Scientific reports vol. 12,1 4042. 8 Mar. 2022, doi:10.1038/s41598-022-08053-y 2. Everts, Peter A et al. “Assessing clinical implications and perspectives of the pathophysiological effects of erythrocytes and plasma free hemoglobin in autologous biologics for use in musculoskeletal regenerative medicine therapies. A review.” Regenerative therapy vol. 11 56-64. 10 May. 2019, doi:10.1016/j.reth.2019.03.009 3. Irmak, Gülseren et al. “Sustained release of growth factors from photoactivated platelet rich plasma (PRP).” European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V vol. 148 (2020): 67-76. doi:10.1016/j.ejpb.2019.11.011 4. Drohomirecka, Anna et al. “Low-level light therapy reduces platelet destruction during extracorporeal circulation.” Scientific reports vol. 8,1 16963. 16 Nov. 2018, doi:10.1038/s41598-018-35311-9 5. Zhang, Qi et al. “Potentials for prolonging shelf-life of platelets by near infrared low-level light.” Journal of biophotonics vol. 12,5 (2019): e201800390. doi:10.1002/jbio.201800390