What are telocytes?

Telocytes are interstitial cells with a small cell body and long, very thin extensions called telopodes. These structures can extend over comparatively long distances in tissue and establish contact with different cell types.

They have been described in skin, heart, lung, liver, digestive tract, joint-related tissues and other organs. They are often found close to blood vessels, nerve fibres or stromal cell niches.

Distinction from fibroblasts

Telocytes are not simply unusually long fibroblasts. Morphologically, they differ by their small cell body and long, thin processes with alternating dilations, mainly described by electron microscopy. There is no single marker that clearly defines telocytes for routine use.

PRP: biological basics

Platelet-rich plasma, or PRP, is plasma obtained from autologous blood with an increased platelet concentration. Venous blood is collected, anticoagulated and centrifuged. Depending on the system and protocol, different fractions are produced and the platelet-rich portion is collected.

PRP contains platelets and platelet-derived mediators, including growth factors and cytokines that can be involved in physiological repair and remodelling processes. The exact composition is not uniform.

Influencing factors include blood volume, anticoagulant, tube type, centrifugation parameters, RCF/g-force, spin time, leukocyte content, activation and time between preparation and use.

Possible interactions between telocytes and PRP mediators

Research is examining whether telocytes can respond to mediators contained in PRP, especially signalling molecules released by platelets after activation. These are mechanistic hypotheses, not proof of clinical effect.

Receptors and signalling pathways

Receptor axes have been described for telocytes that could in principle interact with PRP-associated mediators, including PDGF-, TGF-β- and VEGF-related pathways. Such mechanisms are biologically plausible, but they do not prove clinical relevance.

Cell contacts and vesicles

Telocytes form contacts with other cell types and can release extracellular vesicles containing proteins, microRNAs and other signalling molecules. PRP also contains vesicular components. Mutual influence is experimentally conceivable; its clinical relevance is not clarified.

Preclinical and histological research fields

Several studies examine telocytes in tissues involved in remodelling and repair. The following examples are for scientific classification only. They do not describe established treatment areas and are not treatment recommendations.

Skin models and stromal repair zones

In preclinical and histological work, telocytes have been described in healing skin areas, sometimes near newly formed microvessels and stromal repair zones. A 2024 publication discusses telocytes as possible participants in PRP-associated cellular processes in skin tissue. These observations do not prove a clinical PRP treatment effect.

Myocardial and joint-related tissue research

In the myocardium, telocytes are investigated as part of the stromal network. In joint-related tissues, such as synovial membrane, their specific role remains a research question. Clinical PRP studies in orthopaedic questions are heterogeneous and do not prove a direct telocyte-mediated effect.

Why the evidence is limited

There is no single marker that reliably detects telocytes in routine practice. Electron microscopy, morphology and marker panels are often required, which limits comparability and reproducibility.

Cell culture, animal and tissue studies can describe biological mechanisms. They do not automatically show that a procedure is clinically effective, safe or superior in humans. Correlation is not causality: the observation of telocytes in tissue remodelling does not prove that they control the process.

Why PRP studies are difficult to compare

Practical classification for professional users

PRP should not be explained or promoted through telocyte-related efficacy claims. A clean, documented and indication-specific approach within the relevant legal, hygienic and product-specific requirements is more appropriate.

• document the PRP system and instructions for use
• record blood volume, anticoagulant and single-use materials
• use RCF/g-force rather than RPM alone
• document spin duration, final volume and fraction
• record LOT/batch of materials
• document information, consent and follow-up

Safety, information and limits

PRP applications belong in trained hands and must be performed according to the relevant system specifications. Possible local reactions include pain, swelling, redness or bruising at the application site. Infections are rare but possible with improper handling. These notes do not replace medical evaluation or product-specific instructions for use.

Conclusion

Telocytes are an interesting topic in current tissue research. A possible interaction with PRP mediators is biologically plausible, but the current evidence is not sufficient to derive established clinical mechanisms, treatment recommendations or standardised protocols. Communication should clearly distinguish between preclinical hypotheses, histological observations and clinically established evidence.