Abstract

Objectives: To present a novel method for treating acne scars using diluted calcium hydroxylapatite (CaHA) delivered via a needle-free injector. Attendees will learn about this technique’s efficacy, precision, and ability to stimulate collagen and dermal remodeling, with biopsy and ultrasound findings supporting enhanced tissue regeneration. Introduction: Acne scars are challenging to treat with conventional methods. CaHA fillers are known for stimulating neocollagenesis. This study explores the effectiveness of delivering micro-droplets of diluted CaHA into the dermis using a needle-free injector to promote collagen production, scar elevation, and skin regeneration. Materials / method: 30 patients with atrophic acne scars received CaHA diluted 1:10 via a needle-free injector. Each session delivered 2,000–3,000 micro-injections over 5 minutes. Scar depth was measured using sonography and 3D imaging. Biopsies were taken from consenting patients to evaluate collagen synthesis and stem cell markers (CD31, CD34). Results: Patients showed significant improvement in scar depression and skin texture. Sonography confirmed accurate intradermal CaHA deposition. Biopsy revealed increased fibroblast activity, collagen, elastin, and vascularity. CD31 and CD34 expression increased by 68.5% and 59.2%, respectively. Active acne also improved without recurrence. Conclusion: Needle-free injection of diluted CaHA is a safe and effective treatment for acne scars, combining precision delivery with regenerative stimulation. It improves dermal quality, enhances collagen production, and promotes stem cell activation, offering a promising alternative to laser or microneedle-based approaches.