Evaluating PDGF+ with a 2910 nm Laser in Skin of Color

With increasing interest in regenerative medicine for the treatment of dermatologic conditions, current studies explore the efficacy and safety of various therapies including PRP (platelet-rich plasma), PPP (plasma-poor platelet), PRF (plasma-rich fibrin), and exosome therapy for both medical and aesthetic outcomes. PRP, obtained via the centrifugation of autologous blood, contains high concentrations of platelets, growth factors, and adhesion proteins.¹ Platelet-derived growth factors (PDGF) increase dermal fibroblast production of type I procollagen and hyaluronan synthesis, highlighting their role in skin fibrosis, wound healing, tissue remodeling, and skin aging.² Despite their common use, PRP and PRF are limited by their  inconsistent yield of growth factors, need for blood draw, and risk of contamination from other blood products.^3,4 A commonly noted limitation across studies is the heterogenicity in PRP preparation and administration alongside a lack of standardization in outcome measures.⁴ Similarly, while studies suggest exosomes’ potential in skin rejuvenation and hair restoration, the FDA maintains both a consumer and physician warning on such therapies due to a lack of regulatory standards. 

Laser resurfacing generate a controlled skin injury to stimulate a wound-healing response, thereby enabling collagen remodeling to improve skin tone and texture.⁵ Topical agents including PRP and exosomes are commonly employed after laser treatments to facilitate recovery, enhance cosmetic results, and reduce adverse events, which include erythema and dyspigmentation.⁵ 

Despite documented synergy between PRP and laser modalities in enhancing aesthetic results,^6,7 there is a lack of consensus regarding required concentrations for treatment success in both inter-and intra-patient outcome variability. A more recent innovation—pharmaceutical-grade pure platelet-derived growth factor (PDGF+)—provides an alternative to PRP/PRF that no longer relies on autologous platelet production while guaranteeing consistent growth factor concentrations.⁸ This case series evaluates the safety and tolerability of PDGF+ following laser treatment for skin rejuvenation in patients with skin of color patients—a population at increased risk for postinflammatory hyperpigmentation. 

Study Design

A series of three African-American patients with Fitzpatrick Skin Type (FST) IV to V underwent superficial ablative 2910 nm mid-infrared fiber laser treatment in Clear mode (depth, 10 µm to 20 µm; spot size, 15 mm; 12.5% coverage), followed by twice daily application of either PDGF+ or bland moisturizer in a split-face design. Transepidermal water loss (TEWL) was measured at baseline, immediately post-treatment, and at Day 1. Blinded Investigator Global Assessment (IGA) scores were noted for hyperpigmentation and erythema at baseline, Day 1 and Day 6. Subject and Physician Clinical Tolerability Scales were also recorded immediately post-laser treatment and at 5, 10, and 15 minutes post-treatment after PDGF+ application on Day 0 and Day 1. 

Results

Our findings showed that the mean percent change (delta) in TEWL from Day 0 to Day 1 was 109.5% (SD = 9.7), range: 101.6% to 120.4%, for the treatment (PDGF+) side and 120.0% (SD = 43.5), range: 92.3% to 170.1%, for the control (bland moisturizer) side, showing no significant difference (p = 0.649) (Figure 1).

Figure 1. Mean TEWL values for treatment and control side. For the PDGF+ treated site, Mean TEWL at pre-treatment, post-treatment and Day 1, across all three patient was 19.80 ± 5.50, 83.74 ± 17.34, and 43.97 ± 9.04, respectively. For the control side, Mean TEWL was 20.48 ± 5.64, 97.82 ± 13.28, and 43.27 ± 5.09, respectively.

Results saw no change in IGA score for hyperpigmentation bilaterally between Day 0 and Day 1 (Figure 1) but demonstrated improvement in scores between Day 0 and Day 6. Notably, all three patients saw a decrease in IGA score for hyperpigmentation on the treatment site, with only one patient noting improvement on the control side (Table). 

Although 2 of 3 patients had an increase in erythema between Day 0 and Day 1, there was no difference in IGA scores between the treatment and control side (Table). Erythema in both patients resolved by Day 6 and returned to baseline presentation (Table). 

On Physician Clinical Tolerability Scale, 1 of 3 patients had an increase in edema (trace to moderate), with equal findings on the treatment and control sides (Figure 2). On Subject Clinical Tolerability Scale, 2 of 3 patients reported mild to moderate burning within 15 min of PDGF+ treatment; symptoms resolved within 30 minutes of application (Figure 1). No patients reported swelling or itching. 

Figure 2. Subject clinical tolerability grading scale for burning.

Discussion 

Scoring for TEWL, hyperpigmentation, and erythema demonstrated comparable results for post-laser topical application of PDGF+ as compared to bland moisturizer, making this a safe option for patients of color. 

In the present study, TEWL measurements were recorded from Day 0 to Day 1 to evaluate skin barrier disruption and retained hydration. Our findings showed topical PDGF+ to be noninferior to bland moisturizer in minimizing moisture loss, although the time frame of assessment was limiting to the inflammatory stage of wound healing. During this stage, platelets aggregate in a fibrin network to re-establish homeostasis and re-form a protective skin barrier to allow for fibroblast proliferation.⁵ Studies have shown that recombinant PDGF human platelet-derived growth factor (rhPDGF) has been successful in treating diabetic lower-extremity ulcers, demonstrating greater complete healing as compared to placebo groups in trials.⁹ Future studies should evaluate TEWL measurements for up to 1 week after laser procedure to better assess whether topical PDGF+ treatment potentially accelerates skin barrier recovery post-laser therapy, as doing so could prevent complications associated with delayed healing or exposure to environmental irritants. 

A common concern when employing laser-based energy devices in darker skin types is the heightened predilection to PIH (postinflammatory hyperpigmentation), which is attributed to increased melanin production and deposition with inflammation in response to thermal injury.¹⁰ 

A review of 369 Asian patients (FST III to V) suggests that among those who experience hyperpigmentation after laser therapy, 85% of PIH cases occurred on the face.¹⁰ Between the types of lasers utilized, PIH was most commonly reported after treatment with fractional carbon dioxide (CO₂) lasers and the 532 nm Q-switched neodymium-doped yttrium aluminum garnet (QS Nd:YAG) lasers (as noted in 43% and 25% of patients, respectively).¹⁰ The present study employed the 2910 nm mid infrared fiber laser to maximize superficial ablation without bulk-heating. Clear mode settings were applied with the intention of targeting the stratum corneum. 

Our results showed decreased IGA scores for hyperpigmentation between Day 0 and Day 6 on the treatment side compared to control, though statistical significance was limited by small sample size. These findings align with previous studies evaluating the incidence of PIH in patients treated with topicals containing EGF (epidermal growth factor) following ablative-laser resurfacing.⁵ A review that included 169 total patients showed no significant difference in PIH incidence in the treatment groups compared to controls.5 Despite this, the EGF group had a significant decrease in melanin index score at 1 month post-laser procedure vs. control groups.⁵ Another study found that 34% of patients saw prevention of PIH with application of topical EGF post-laser treatment.¹⁰ Still, PIH incidence between the treatment and control groups was insignificant.¹⁰ 

Our findings suggest that the post-procedural application of topical PDGF+ may be safely employed in patients with darker skin types, without increasing the risk for PIH. While current data surrounding the effectiveness of topical PDGF/PDGF+ in post-laser recovery are limited, the present case series is among the first to assess its safety and tolerability in patients with skin of color. Overall, the subjects tolerated the treatment without adverse event, demonstrating marginal difference from control outcomes. Larger-scale studies are warranted to further evaluate post-treatment efficacy following both superficial and deep ablative procedures, and to explore PDGF+’s potential to accelerate wound healing.