Enf.ª Ângela Faria

Nurse in the Outpatient Service 

Tissue repair and platelet-rich plasma

HPA Magazine 24 // 2025

Healing consists of a complex and dynamic process involving biological and molecular events. This same tissue repair comprises the phases of haemostasis, inflammation, proliferation and tissue remodelling/maturation. The progression between these events is mediated by a wide range of cell and soluble biomarkers – notably Growth Factors (GFs) and cytokines.

In certain tissues – such as ligaments or tendons – tissue repair is delayed due to reduced blood supply and, consequently, reduced cell renewal.
Numerous studies have been developed in response to the growing need for treatments that not only promote tissue repair, but also act as facilitators in the body's natural healing process. These treatments aim to complement or replace conventional treatments and stimulate the innate molecular mechanisms involved in tissue regeneration.
As a result of these studies, Platelet Rich Plasma (PRP) emerged. PRP is an autologous fluid –meaning it is a product that derives from the patient’s own blood – which after centrifugation contains a high concentration of platelets in its composition.
Platelets are anucleate components of blood, approximately 3μm in diameter, with a key role in haemostasis.
During the tissue repair process, platelets are activated, change shape, and eventually release cytokines and GFs – more specifically: platelet-derived growth factor (PDGF), transforming growth factor beta (TGF- ), vascular endothelial growth factor (VEGF), insulin-like growth factor 1 (IGF-1), fibroblast growth factor (FGF) and epidermal growth factor (EGF). These same GFs mediate proliferation, cell migration, differentiation, cell cycle and angiogenesis.
PRP is the blood-derived product that has revolutionized regenerative medicine. Its use span across several specialties such as orthopaedics, plastic surgery, dermatology, ophthalmology, vascular surgery, gynaecology, among others. Accordingly, several methods have emerged – from topical to injectable application –, guaranteeing promising results and improved quality of life for the patients.
 

However, there is still no standardized and comprehensive protocol for the collection and processing of blood to obtain PRP. Different preparation systems vary in terms of collection volume, final platelet concentration and preparation consistency. And, given the ongoing investment in this area, many innovative methods continue to be improved or developed.
In general, the process begins with a standard blood draw (often using anticoagulants, such as citrate) followed by centrifugation. This allows for the separation of blood components into layers and the isolation of PRP, making it ready for application.
As it is an organic, non-toxic and non-immunoreactive product, PRP has a low incidence of complications/adverse effects. The literature also reports greater efficacy of PPR compared to corticosteroid therapy or hyaluronic acid. Thus, this has become the most widely used blood derivative – ethically uncontroversial – for reducing inflammatory suffering and stimulating anabolism – that is, the synthesis of complex molecules in tissues. 
One additional advantage is the ability to cryopreserve PRP.This not only extends its shelf life but also facilitates transport and overcomes clinical storage limitations. Nevertheless, despite the biological components being stable and suitable for use, a notable loss of biological activity does occur following thawing.
PRP treatment is available at the HPA Saúde Group. Consult a doctor before considering its application.