Unicamp research conducted by chemist Sofia Elisa Moraga Galdames established parameters to assist doctors in obtaining and applying a great ally of regenerative medicine: Platelet Rich Plasma (PRP), a product prepared from the patient's own blood and used with success in therapies for the regeneration of injured tissues and organs.

The study evaluated the influence of anticoagulants on the production and properties of PRP, establishing the most appropriate anticoagulant to obtain the best quality Platelet Rich Plasma. Anticoagulants are essential for obtaining PRP, preventing the blocking of clotting reactions and keeping the blood fluid.

The work evaluated PRP using mesenchymal stem cells derived from human adipose tissue. According to researcher Sofia Galdames, an ongoing clinical study on patients at the Hospital de Clínicas (HC) at Unicamp is presenting very promising prospects.

According to her, the main results of the research demonstrated that a type of anticoagulant based on citric acid, sodium citrate and dextrose (ACD-A) is among the best evaluated for stimulating cell growth, thus being able to accelerate further regeneration of damaged tissue.

Furthermore, the work established protocols for the preparation of PRP with anticoagulants, using a mathematical model that evaluated the properties of blood in the recovery efficiency of Platelet-Rich Plasma. The effects of the anticoagulants ethylenediamine tetraacetic acid (EDTA), sodium heparin (HP), sodium citrate (CIT) and citric acid, sodium citrate and dextrose (ACD-A) were studied.

“The standardization of PRP is still a challenge because studies that encompass basic science are scarce. The selection of anticoagulants to obtain PRP has not received due attention, both in clinical application and in basic research. There are few studies reporting the influence of different anticoagulants on the process of obtaining PRP. Therefore, the work is relevant, especially because it should contribute to improving the patient’s health and treatment condition”, considers the study author.

Sofia Galdames' research was part of her master's thesis defended in November 2015 at the Postgraduate Program at the Faculty of Chemical Engineering (FEQ) at Unicamp. The study was guided by professor Maria Helena Andrade Santana, who works in the Department of Materials and Bioprocess Engineering (DEMbio) and coordinates the Unit's Biotechnological Process Development Laboratory (LADPB).

There was collaboration with the Umbilical Cord and Placental Blood Bank of the Hemocentro (Hematology and Hemotherapy Center) and the Orthopedic Biomaterials Laboratory (Labimo), both linked to the Faculty of Medical Sciences (FCM) at Unicamp. In addition to professor Ângela Cristina Malheiros Luzo, who coordinates the Hemocentro Blood Bank, and professor William Dias Belangero, from Labimo, the research involved the partnership of orthopedist and Unicamp researcher, José Fábio Lana. The Coordination for the Improvement of Higher Education Personnel (Capes) financed the project, granting a scholarship to the researcher.

According to the author of the work, Platelet-Rich Plasma has been considered highly effective in regenerative medicine. Sofia Galdames reports on studies that show the success of using PRP in the regeneration of various tissues, such as tendons, cartilage, bone tissue, skin ulcers in diabetics, in addition to helping in the recovery of knees with osteoarthritis and muscle injuries.

“This is explained by the fact that Platelet-Rich Plasma’s ability to supply large amounts of growth factors and accelerate the regeneration process, in addition to avoiding any type of rejection in the applied region, as it is an autologous product, that is, extracted from the individual.”

The Unicamp scholar explains that tissue repair occurs in stages in the human body: first, dead cells are removed from the site of injury; then the proliferation and migration of cells to the location where the tissue is damaged; and, finally, the formation of new vascular structures. She adds that growth factors, substances responsible for communication between cells, play an important role, coordinating this entire process.

“PRP contains a concentration of growth factor three to five times higher than the level considered 'normal', with approximately 70% of stored growth factors being released within 10 minutes, and almost 100% being released within a hour. However, small amounts can continue to be produced by platelets for 8 to 10 days. This is what the literature on the subject reports, but it will depend on the type of PRP activation”, he reveals.

PRP Quality

Sofia Galdames recognizes that there are numerous challenges to obtaining a high-quality PRP. She clarifies that this is directly related to the number of platelets and their integrity. “The greater the number of intact platelets, the greater the amount of growth factors released during the application of PRP. And this depends, mainly, on the centrifugation process and the choice of anticoagulant.”

The chemistry graduate from Unicamp explains that the centrifugation process is used to accelerate the separation of an anticoagulated venous blood sample. During this process, cell fragments, such as platelets, become dispersed in the plasma while red blood cells rapidly sediment under the action of centrifugal force.

3rd generation PRP

Platelet-Rich Plasma has been used since the 1960s, according to the Unicamp study. At first it was only used as an alternative to whole blood transfusion. Composed of a concentrate of platelets, leukocytes and proteins, dispersed in a small fraction of plasma, PRP is already in what Sofia Galdames considers to be its third generation.

“In the last decade, the use of PRP has represented an important option for smaller surgeries, such as the treatment of bones and cartilage that have difficulty healing. And more recently, Platelet-Rich Plasma has been used together with biomaterials, such as, for example, hyaluronic acid, a substance naturally present in the human body. This biomaterial serves as a kind of structure in implants for bone and soft tissue regeneration. One of my research suggestions for future work is to evaluate the interactions of 3rd generation PRP, that is, associated with biomaterials in adult mesenchymal cells.”

Publication 

Dissertation: “Study of the influence of anticoagulants on the production and properties of Platelet-Rich Plasma”
Author: Sofia Elisa Moraga Galdames
Advisor: Maria Helena Andrade Santana
Unity: Faculty of Chemical Engineering (FEQ)
Financing: Capes