Creative Touch Permanent Makeup and Aesthetics

Tissue regeneration describes the biological process by which damaged or depleted tissue is restored through coordinated cellular activity – but regeneration is not a single outcome. It exists on a continuum from true like-for-like tissue replacement at one end, through functional-but-imperfect repair, to fibrotic scar replacement at the other. Which outcome a given healing event produces is determined by three principal variables: the balance of TGFβ isoforms in the repair environment, the transition timing of macrophages from pro-inflammatory to pro-regenerative phenotype, and the degree to which inflammageing has impaired the tissue’s stem and progenitor cell capacity. Regenerative aesthetics treatments – iPRF, polynucleotides, growth factor therapies – intervene in the proliferation and remodelling phases of tissue repair with the aim of shifting outcomes toward the regenerative end of the continuum. The inflammatory environment of the target tissue at the time of intervention is a primary determinant of whether they succeed.

Tissue regeneration is one of the most frequently invoked concepts in aesthetics – and one of the least precisely defined. “Regenerative treatment,” “stimulating the skin’s own repair processes,” and “activating natural renewal” appear across product marketing and clinical content, usually without distinguishing between the three genuinely different biological outcomes that repair processes can produce. That distinction matters practically: it explains why treatments work differently in different tissue environments, why two clients receiving identical protocols can have meaningfully different outcomes, and why the inflammatory state of the skin before treatment is not a secondary consideration but a primary determinant of what a regenerative stimulus will achieve.

Regeneration, Repair, and Fibrosis: The Continuum

When tissue is damaged, the body initiates a repair response whose outcome sits somewhere on a continuum between two extremes. At the regenerative end, damaged tissue is replaced with architecturally and functionally identical new tissue – the same cell types, the same extracellular matrix organisation, the same mechanical properties as the original. At the fibrotic end, damaged tissue is replaced with generic scar tissue – collagen-dense, mechanically stiff, poorly organised, and lacking the specialised cells and structures of the original. Between these extremes lies the most common outcome in adult human tissue: functional repair – tissue that is restored well enough to perform its basic role but that lacks the structural sophistication of the original. ^[1]

The reason adult mammals default to repair rather than true regeneration – whilst foetal wound healing in early gestation produces near-perfect tissue reconstruction with no scar – is not entirely resolved, but the evidence points to the inflammatory response as the key variable. Foetal wounds heal in a sterile, low-cytokine, TGFβ3-dominant environment with minimal macrophage infiltration; adult wounds heal in an environment rich in TGFβ1, TGFβ2, and inflammatory cytokines that drive fibrotic deposition. The foetal exception is not a curiosity – it is the biological proof of concept that the inflammatory environment, not the cellular repair machinery itself, is the primary determinant of where on the continuum an outcome lands. ^[4]

For aesthetics purposes, this framing redefines what regenerative treatments are doing: they are not simply delivering a biological stimulus and waiting for regeneration to occur. They are attempting to shift the local tissue environment toward the conditions under which regeneration – rather than repair or fibrosis – is the predominant outcome.

The Four Phases of Tissue Repair

Tissue repair proceeds through four sequential but overlapping phases. Regenerative treatments do not act uniformly across all four – understanding where they intervene clarifies what they can and cannot influence.

Haemostasis (minutes to hours) arrests bleeding through platelet aggregation and provisional fibrin matrix formation. This phase also initiates the subsequent inflammatory response through platelet degranulation and growth factor release – PDGF, TGFβ, VEGF, and EGF among them. In PRP and iPRF treatments, the injected platelet concentrate is delivering a concentrated version of this same initial growth factor release into tissue where no injury-initiated haemostatic response has occurred, seeding the repair sequence from the proliferative phase without the preceding inflammatory phase.

Inflammation (hours to days) recruits neutrophils and macrophages to the wound site, clearing debris and pathogens and producing the cytokine signals that transition the repair response into proliferation. This phase is necessary but its duration and intensity are critical: a controlled, resolving inflammatory phase facilitates progression to regenerative remodelling; a sustained or dysregulated inflammatory phase – the condition in ageing, rosacea, and chronically inflamed tissue – impairs the transition and drives the outcome toward fibrosis. ^[2]

Proliferation (days to weeks) is the phase most directly targeted by regenerative aesthetics treatments. Fibroblasts proliferate and migrate into the repair zone, synthesising new collagen (initially type III, subsequently remodelling toward type I), glycosaminoglycans, and other extracellular matrix components. Keratinocytes re-epithelialise the surface. New vasculature forms through angiogenesis. Growth factor signalling – from platelets, macrophages, and the fibroblasts themselves – drives and coordinates this activity. iPRF’s growth factor payload ( PDGF, TGFβ, IGF-1, VEGF, FGF) acts primarily on this phase, amplifying the proliferative signal in tissue where the endogenous platelet-derived growth factor concentration may be insufficient to drive optimal fibroblast activation.

Remodelling (weeks to months to years) reorganises the provisional collagen matrix laid down during proliferation into the mechanically organised architecture of mature tissue. Type III collagen is progressively replaced by type I; collagen fibres are cross-linked and aligned along mechanical stress lines; non-essential vasculature regresses. This phase is the biological basis for the extended timelines of regenerative treatment outcomes – the collagen laid down in the proliferative phase is not the collagen that determines the final visible result. Polynucleotides (PDRN) support this phase specifically through MMP suppression – reducing the enzymatic degradation that would otherwise break down newly synthesised matrix before remodelling is complete, and through adenosine receptor activation that promotes fibroblast activity during the extended remodelling window.

The TGFβ Isoform Balance

Transforming growth factor beta (TGFβ) is the central cytokine regulator of the repair/fibrosis/regeneration outcome, and its isoform composition in the repair environment is the molecular switch between these outcomes. ^[3]

TGFβ1 and TGFβ2 are the dominant isoforms in adult wound healing. They drive fibroblast activation, collagen synthesis, and myofibroblast differentiation – the contractile cells responsible for wound contraction and, in excess, for the dense collagen deposition of fibrotic scarring. Both isoforms suppress MMP activity (reducing matrix degradation, which maintains scar tissue) and promote epithelial-mesenchymal transition. Their activity is appropriate in the acute repair phase but becomes counterproductive if sustained, producing the excessive and disorganised collagen deposition of hypertrophic scars or the tissue rigidity of chronic fibrosis.

TGFβ3 is the isoform predominant in foetal wound healing and is substantially less abundant in adult repair. It promotes organised matrix deposition, facilitates the M1→M2 macrophage transition described below, and has anti-fibrotic rather than pro-fibrotic downstream signalling. Studies in adult tissue engineering and growth factor therapy research have consistently shown that shifting the TGFβ1:TGFβ3 ratio toward TGFβ3 produces more regenerative and less fibrotic outcomes. Platelet-derived growth factor preparations including iPRF contain TGFβ in a profile that includes TGFβ3 alongside the more abundant TGFβ1 – partly explaining the more regenerative tissue response observed with platelet concentrate therapies compared with injury-alone healing. ^[8]

Macrophage Phenotype: The Critical Checkpoint

The transition from the inflammatory phase to the proliferative and remodelling phases is gated by macrophage phenotype – and this checkpoint is where the regeneration/fibrosis outcome is most directly determined. ^[9]

M1 macrophages are the pro-inflammatory phenotype recruited in the early inflammatory phase. They produce TNF-α, IL-1β, IL-6, and IL-12, driving pathogen clearance and debris removal. Their activity is essential in the acute phase but must resolve for tissue repair to progress – sustained M1 activity maintains the inflammatory environment that suppresses fibroblast function and skews TGFβ signalling toward the fibrotic isoforms.

M2 macrophages are the pro-regenerative phenotype that dominate the later proliferative and remodelling phases. They produce TGFβ, VEGF, and IL-10, promoting fibroblast recruitment, angiogenesis, and matrix synthesis. The M1→M2 transition is the critical checkpoint: when it occurs on schedule, the repair response progresses toward regeneration; when it is delayed or incomplete – as occurs in chronic inflammation, ageing tissue, and diabetes – the sustained M1 environment drives the outcome toward fibrosis. ^[2]

Cold atmospheric plasma has a directly relevant mechanism here. Its RONS-mediated NF-κB modulation in activated macrophages facilitates the M1→M2 phenotype transition – providing one of the mechanistic explanations for CAP’s ability to convert a chronically inflamed tissue environment into one more capable of supporting regenerative outcomes. This is the biological basis for the treatment sequencing logic: resolving the inflammatory environment (CAP) before delivering a regenerative growth factor stimulus (iPRF, PDRN) is not a preference – it is a mechanistic imperative if the target tissue’s macrophage population is predominantly M1 at the time of treatment.

How Inflammageing Impairs Regenerative Capacity

In young, healthy tissue, the four-phase repair sequence proceeds with reasonable fidelity toward functional regeneration. In ageing tissue, chronic low-level inflammation – inflammageing – impairs the sequence at multiple points, progressively shifting the default outcome from regeneration toward fibrosis and from complete repair toward incomplete repair. ^[6]

The primary mechanisms are:

SASP cytokine suppression of progenitor cell function. Senescent cells – including the senescent adipocytes covered in the Subcutaneous Tissue entity – secrete SASP cytokines (IL-6, IL-8, TNF-α, MMP-3) into the local tissue environment. These cytokines suppress the proliferative capacity of adjacent stem and progenitor cells, reducing the pool of cells available to execute the regenerative response. A PNAS 2019 study demonstrated this directly: skeletal stem and progenitor cell function was significantly impaired by the inflammatory environment of ageing tissue, and reducing that inflammatory environment – rather than directly manipulating the stem cells – restored their regenerative capacity. ^[5] The implication is that the regenerative capacity of aged tissue is not fixed – it is environmentally suppressed, and can be partially restored by addressing the inflammatory environment.

Chronic NF-κB activation and the pro-fibrotic skew. NF-κB, the master transcription factor of the inflammatory response, is chronically activated in ageing tissue at a low level that does not produce acute inflammation but that maintains a baseline pro-inflammatory cytokine milieu. This chronically elevated NF-κB activity biases macrophage polarisation toward M1, sustains TGFβ1 dominance over TGFβ3, and suppresses the anti-inflammatory signalling that would normally facilitate the M1→M2 transition. The result is a tissue environment that is never fully in the pro-regenerative state required for optimal repair – even between injury events.

Impaired growth factor responsiveness. Ageing fibroblasts demonstrate reduced receptor expression and downstream signalling response to growth factors including PDGF and IGF-1, partly through chronic cytokine exposure and partly through intrinsic cellular ageing mechanisms including telomere shortening. This means that identical growth factor concentrations – from iPRF, for example – produce a weaker fibroblast activation response in aged tissue than in younger tissue, contributing to the clinical observation that older clients may require more treatment sessions to achieve comparable outcomes. ^[7]

Clinical Pearl The question “why do two clients having identical treatments get different results?” is one of the most common and least well-answered in aesthetics consultations. The answer lies almost entirely in tissue environment rather than treatment delivery: the client whose tissue has a lower senescent cell burden, a more responsive macrophage population, and a less NF-κB-skewed baseline will produce a more regenerative outcome from the same iPRF or PDRN protocol as the client whose tissue inflammageing has impaired all three. This is the mechanistic basis for investing in skin health as a precondition for regenerative treatment rather than as an alternative to it.