treatment at a moderate-to-high laser temperature (7 Joules) set for hyperpigmentation/melasma treatment (ie, random laser application to prevent overheating of the skin) to the face, chest, and back with 6 passes per treatment area. After the last pass, the patient was assessed for discomfort and reported a pain level of 8 out of 10 for heat discomfort, stinging, and burning. After the assessment, a total of 3 mL of the 5 x 109 concentration of exosome serum was applied across the treatment areas. Immediately after application, the patient reported a reduction in the severity of discomfort to a pain level of 4 out of 10. As observed in Figure 1, erythema and swelling recovery time was also reduced.
Case Study Patient 2: One drawback of PRP is that the bioactivity of platelets and growth factors isolated from older individuals may be less efficient than in younger counterparts, impacting clinical effectiveness.5 Therefore, comparing the efficacy of PRP vs exosome therapy in older patients is of particular clinical interest. In Figure 2, a 72-year-old female patient is shown following after treatment with CO2 fractional laser therapy followed by PRP. The patient demonstrated erythema and swelling with PRP that continued for a week after treatment (Figure 2A). After receiving the same treatment, 4 years later, followed by 2.5 mL of the 12.5 x 109 exosome serum solution, the patient's skin showed reduced swelling at 4 days after treatment with minimal erythema and an overall reduction in peak post-treatment severity (Figure 2B). The reduced downtime, swelling, and discomfort contributed to increased patient satisfaction with the procedure.
Case Study Patient 3: A 49-year-old female patient who suffered a dog bite in the lower lip (Figure 3A) was treated by an emergency room physician (non-plastic surgeon) and presented for treatment 20 hours after wound stitching (Figure 3B). At this time point, the wound was cleaned with a hypochlorous acid solution, and 2.5 mL total of the 12.5 x 109 exosome solution was slowly applied, a few drops at a time, over 10 minutes using a 32 G half-inch needle, allowing each aliquot of serum to be absorbed by the skin before the subsequent application. Wound healing could be observed as early as 18 hours after exosome application. Although the emergency room estimate for healing of this type and location of traumatic injury was estimated to be 6 months, by day 10 (Figure 3C), the wound was completely closed, with no evidence of fibrotic tissue, and with minimal scarring and well preserved sensory and motor function. Within this time period, lip function was entirely restored, and evidence of scaring was nearly absent.
CONCLUSION
PRP is an autologous concentrate derived from a patient's own serum and its acquisition is a multi-step process that requires access to specific equipment and carries handling and contamination risks.3 Furthermore, PRP can contain variable numbers of platelets and growth factors, which can affect bioactivity.5 For more mature patients, PRP may not be able to provide enough of the cellular factors necessary, which is problematic as these are the patients who need healing and accelerated recovery the most. In contrast, harvesting and preparation of exosomes in a laboratory and according to GMP guidelines controls for variability in efficacy and removes the need for further manipulation in the clinic, allowing their application with no interruption in workflow and the expectation of a predictable level of bioactivity across patient populations and between batches.
The discovery of the ability of exosomes to act as carriers of genetic messages between cells has caused an explosion of interest in these micro-vesicles.7 In 2020, exosomes carrying some of the same genetic material contained within the exosomes used in these case studies (miRNA 425-5p and 142-3p; Exovex) were demonstrated to promote wound healing and to reduce scarring, potentially through the inhibition of transforming growth factor (TGF)-beta1 expression within injured tissue, suggesting a potential mechanism for their effects in promoting accelerated recovery time and traumatic injury.11 Indeed, a clinical study investigating the safety and efficacy of human placental mesenchymal stem cell-derived exosomes in the acceleration of wound healing after infection was recently (June 2022) initiated, further evidence of the interest in their clinical potential.12
