Percutaneous collagen induction (microneedling) for the management of non-atrophic scars: literature review

Iosifidis C, Goutos I. Scars, Burns & Healing. 2019;5. DOI: 10.1177/2059513119880301. SAGE Publications. PubMed PMID: 31807320.

"Needling techniques are increasingly popular and involve the use of a device to produce numerous tiny perforations in the skin, stimulate collagen production and resurface the treated area... Needling has been appraised extensively in the atrophic acne scar literature with eight existing randomised controlled trials... [producing] comparable clinical results to other mainstream adjuncts with explicit advantages relating to the lower risk of side effects."

Clinical significance: This PubMed-indexed systematic review in the specialist journal Scars, Burns & Healing (SAGE) provides the most comprehensive evidence base specifically for PCI in non-atrophic scars — directly applicable to the post-surgical and traumatic scar cohort most commonly referred. The evidence supports PCI as a first-line consideration with a favourable safety profile superior to fractional laser.

Microneedling for the Treatment of Scars: An Update for Clinicians

Systematic Review. Clinical, Cosmetic and Investigational Dermatology. Dove Medical Press (PubMed-indexed). December 2020.

"Tissue histology after MN shows thickened epidermis, and an increase in dermal collagen and elastic fibre deposition. Over a period of weeks to months, newly formed type III collagen becomes mature type I collagen causing skin tightening and a decrease in the appearance of scars."

Clinical significance: Histological confirmation of tissue-level structural change (type III → type I collagen conversion, epidermal thickening) validates MCA as producing genuine dermal remodelling rather than superficial cosmetic effect. This distinction is critical for healthcare professionals seeking evidence of measurable tissue change in their patients.

Microneedling — A Form of Collagen Induction Therapy: Our First Experiences

Pilot Study. PubMed. PMID: 28869385. 2016–2017 (published 2017).

"The microtraumatization of scars with the Dermaroller leads to activation of the healing cascade, activation of growth factors which activate cell proliferation in the wound, increased synthesis and deposit of collagen-elastin complex with successive transformation of collagen III to collagen I, to neoangiogenesis and thus to accelerated scar remodelling... Objective evaluation with the Vancouver Scar Score showed an improvement of an average of two points before and after treatment."

Clinical significance: Validates use of the Vancouver Scar Scale as an objective outcome measure and demonstrates clinically meaningful improvement in post-burn scar patients — a population where scar-related functional restriction is particularly significant for physiotherapy and rehabilitation colleagues.

Accelerated burn wound healing with photobiomodulation therapy involves activation of endogenous latent TGF-β1

Arany PP et al. Scientific Reports (Nature Portfolio). 2021. DOI: 10.1038/s41598-021-92650-w. PMC: PMC8238984.

"PBM treatments improved burn wound healing in mice with elevated TGF-β signalling (phospho-Smad2) and reduced inflammation-associated gene expression... PBM treatments downregulated the expression of 18 [pro-inflammatory] genes... and upregulated 5 genes" consistent with a pro-regenerative phenotype. "TGF-β1 signalling has a central role in improved burn wound healing following PBM treatments."

Clinical significance: Published in Scientific Reports (Nature Portfolio), this study provides molecular-level mechanistic evidence for PBM's role in accelerating wound healing and resolving inflammation through TGF-β1 and Smad signalling — the same pathways central to scar maturation and tissue remodelling. Directly relevant to practitioners treating post-traumatic and post-surgical patients.

Photobiomodulation Activates Coordinated Signaling Networks to Modulate Inflammation, Adaptive Stress, and Tissue Healing via Redox-Mediated NF-κB–TGF-β1–ATF-4 Axis

Ponnusamy S, Amin M, Bhat A, et al. Cells (MDPI). 2026 Jan;15(1):88. DOI: 10.3390/cells15010088. PMC: PMC12785302. University at Buffalo / NIH affiliation.

"PBM downregulates inflammatory and apoptotic pathways while activating stress-adaptive responses in the NF-κB pathway... PBM primarily generates ROS intracellularly within mitochondria, which then diffuse extracellularly to activate latent TGF-β1. This activation triggers ATF-4 expression through both canonical (Smad3) and non-canonical (p38, ERK) TGF-β signalling pathways."

Clinical significance: This highly current NIH-affiliated study (2026) provides the most detailed mechanistic account of how PBM modulates the NF-κB inflammatory axis — the primary driver of chronic, dysregulated inflammation seen in hypertrophic and keloid scarring. Essential reference for clinicians managing patients with inflammatory scar pathology or chronic tissue irritation.

Photobiomodulation as Medicine: Low-Level Laser Therapy (LLLT) for Acute Tissue Injury or Sport Performance Recovery

Comprehensive Review. Journal of Functional Morphology and Kinesiology (MDPI). 2024;9(4):181. PMC: PMC11503318.

"In vitro studies show that LLLT increases cell viability, cell migration, proliferation and collagen synthesis. LLLT induces macrophages to release factors that stimulate fibroblast proliferation. In addition, LLLT promotes the production of interleukin-1α (IL-1α) and interleukin-8 (IL-8), which stimulate the migration of keratinocytes. LLLT also increases the expression of platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β)."

Clinical significance: Particularly relevant for physiotherapists, sports medicine practitioners, and chiropractors, this review contextualises PBM within an injury and recovery framework. It confirms that PBM simultaneously activates multiple wound healing pathways — growth factor upregulation, macrophage activation, keratinocyte migration — making it a genuinely systemic cellular stimulus rather than a single-mechanism intervention.