Micro-Needling Depth Penetration, Presence of Pigment Particles, and Fluorescein-Stained Platelets: Clinical Usage for Aesthetic Concerns

BACKGROUND: Aesthetic micro-needling (MN) has demonstrated skin permeability to cosmeceutical ingredients and platelet-rich plasma by creating reversible micro-channels in the skin. OBJECTIVES: The purposes of this study were to determine: (1) actual needle depth-penetrations by adjusting needle lengths in a disposable tip of an electric MN device; (2) time-dependent passage of pigment and platelets; and (3) safety and efficacy profiles in patients. METHODS: Excised micro-needled pre-auricular skin was used to determine actual depths of tissue penetration with six needle lengths, and the presence of massaged pigment particles (histological examination) and fluorescein-labeled platelets (confocal laser microscopy) in 1 mm depth micro-channels over an hour. Patients were treated for wrinkles and skin laxity, scars, and alopecia with cosmeceuticals and plasma-rich platelets. RESULTS: Actual needle penetrations closely matched settings up to 1.0 mm, but were less consistent at settings from 1.5 to 2.5 mm. The optimal time for massaging pigment particles and labeled platelet-rich plasma (PRP) down 1.0 mm micro-channels was between 5 to 30 minutes after MN. Patients treated in the Skin Care Center (cosmeceuticals, 0.25-1 mm depth) and Surgical Center (PRP, 0.25-2.5 mm) demonstrated statistically significant improvements (P ≤ .05) in wrinkle effacement, skin laxity, scar softening, and hair growth by Patient and Observer Satisfaction Scores at 12 months. The average hair count in a 10 mm spot size at baseline (88.3 ± 22.5) increased at the 12 month evaluation period (133.6 ± 13.8). All patients experienced minimal side-effects. CONCLUSIONS: MN alone or in combination therapy resulted in safe and effective treatments from implemented guidelines. LEVEL OF EVIDENCE: 3 Therapeutic.