Can collagen sheet work as a catalyst in the healing process of nonhealing ulcers with platelet-rich plasma membrane? – correspondence

Dear Editor, Platelet-rich plasma (PRP) is clinically used in liquid or gel form to promote tissue repair. Conventional PRP is often difficult to handle because of the poor mechanical properties and requires application over a specific site, otherwise, released growth factors could be washed out during an operation. In 2001, Choukroun et al. developed platelet-rich fibrin (PRF) in France and prepared a protocol for PRF to accumulate platelets and release cytokines in a fibrin clot. Few systems like Fibrinet and Selphyl are available commercially, which give the end product as a dense, pliable, platelet-rich fibrin matrix (PRFM). PRFM maintains its mechanical properties throughout the testing process. There have been not many studies yet where a membrane over a scaffold of collagen sheet based on the concept of commercial kits, using fresh blood be used to understand platelet-rich plasma membrane (PRPM) efficacy in nonhealing ulcers of various causes. PRP concentrate was first classified in 2009 based on its cell content and fibrin architecture. According to this, it is classified into four types: (1) Pure platelet-rich plasma (P-PRP) or leukocyte-poor plateletrich plasma; (2) Leukocyte and platelet-rich plasma (L-PRP); (3) Pure platelet-rich fibrin (P-PRF) or leukocyte-poor plateletrich fibrin; (4) Leukocyte and platelet-rich fibrin (L-PRF). This classification helps to understand the utilities of various component-based concentrates in different clinical situations differently. Important points to consider are as follows: Oral and maxillofacial surgery requirements can be fulfilled by the L-PRP family as L-PRF clots and membranes present a volume and shape which is easy to combine with surgical techniques or as filling/interposition healing biomaterial or as protection healing membrane. They offer strength, and there is a slow release of factors over a long period. It is inexpensive and easy to prepare. P-PRF, in general, is used in other conditions with noteworthy results, such as in the treatment of skin wounds and ulcers. Its applications have been mentioned in orthopedic and sports medicine. But, their disadvantage is that these products are present in a highly polymerized activated form and cannot be used in injectable form. At the same time, the PRP solutions have the advantage of being in liquid form before activation and can be injected easily into various sports medicine or orthopedic conditions. It has an advantage in regenerative medicine, where suspensions need to be injected. The large variations of protocols of this method cause difficulty in comparison to their results. Various PRP families are not routinely used for daily applications but are an alternative to fibrin glues in most other surgeries, especially to improve skin wound healing. The use of the gel form of the PRP on the surgical site makes it a useful surgical adjuvant inmany situations, even though the results are similar to fibrin glues, which remains largely debated. Furthermore, Selphyl (Aesthetic Factors, LLC, Princeton, New Jersey) is a US Food and Drug Administration cleared device, and Fibrinet is available commercially, consisting of materials needed to produce an autologous PRFM. In Selphyl, blood is drawn from the patient into a vacuum collection tube containing a thixotropic separator gel, which is then centrifuged for 6 min at 1100 rpm causing the separation of blood into supernatant plasma/platelet suspension, and the remaining cells are located below in the separation gel. The fibrin, platelets, and serum are then transferred aseptically to a second vacuum tube containing a calcium chloride solution. At this point, fibrin polymerization begins, at first slowly but is completed in 10 min. Once this polymerization has occurred completely, the platelets are embedded in this fibrin matrix. These platelets are highly viable (59% are viable at 7 days after harvesting) and capable of a sustained release of various growth factors over 7 days in vitro; this has been associated with increased endothelial cell proliferation. This slow release is responsible for its higher efficacy. Using this method of formation of PRP, along with using a scaffold of collagen sheet over which the platelet-rich fibrin can be allowed to polymerize as a membrane, can create a more efficacious dressing that is easier to apply and retain.