1. Introduction

Platelets are small and anucleate cells derived from megakaryocytes in the bone marrow. Platelets carry vesicles containing presynthesized proteins in their granules that can be released into the local environment or transported for surface expression. Controlled and coordinated release of these factors is an important part of the normal wound healing process.

Platelet-rich plasma (PRP) is a composition comprising platelets in a plasma at a higher density than normal blood concentration. PRP has been shown to be an effective agent for bone grafting, cartilage regeneration, neovascularization, and tissue deposition in animal studies. These results have increased the interest in PRP and led to the use of PRP in human surgical applications.

PRP has been reported to be used in a wide variety of applications, mainly in problematic wound, maxillofacial, and spinal surgery. The results from these studies have provided strong evidence supporting the clinical use of PRP; however, only few include controls to clearly demonstrate the role of the PRP. Additionally, there is not a precise consensus regarding

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

platelet-rich plasma production and characterization. This lack of consensus also prevents a standard approach in the PRP [1–9].

molecule, is a soluble but unionizable substance. Classical blood preservatives include citrate dextrose and citrate phosphate dextrose as well as other substances to maintain cellular

Platelet-Rich Plasma in Burn Treatment http://dx.doi.org/10.5772/intechopen.70835 89

There are three overlapping stages to wound healing: inflammatory, proliferative, and remodeling. Inflammation is the first response to tissue damage. The goal is to provide rapid hemostasis and initiate a series of reactions leading to tissue regeneration. When blood exits from damaged vessels, a hematoma that fills the tissue space occurs, and platelets have crucial roles in this process. Cytokines and growth factors released from activated platelets and other cells result in several events, including cell migration, proliferation, differentiation, and matrix synthesis [16–19]. The fibrin mesh in the hematoma serves as a transient matrix to continue regenerative space and ensure

Neutrophils, inflammatory cells which first infiltrate the wound area and have lifetimes limited to hours and days, provide rapid defense against infections and removal of tissue debris.

After monocytes reach the wound area, they differentiate into macrophages, and macrophages become predominant cell types in this region. The macrophages, which have lifetimes limited to days to months, support neutrophils in their functions and increase secretion of factors from neutrophils [16–18, 21]. The role of T lymphocytes in a successful wound healing process is still not clearly understood [19]. The mesenchymal stem cells migrate to the wound site to form an unstable cell line that will serve as a skeleton for or formation of the bone, cartilage, fibrous tissue, blood vessels, and other tissues [17]. Fibroblasts migrate to the wound site and begin to proliferate to produce extracellular matrix [17, 22]. Blood vessel endothelium close to the injury area proliferates to create new capillaries, and then these new vessels extend to the damaged

During the proliferative phase, which is the second stage of wound healing, damaged and necrotic tissue is removed from the surrounding and replaced by living tissue that is in accordance with the original tissue structure of that region (e.g., bone, cartilage, fibrous tissue). Mesenchymal stem cells differentiate into fibroblasts, osteoblasts, chondrocytes, and other cell

The third phase, the remodeling phase, is the final stage of wound healing. During this phase, the newly generated tissue reshapes and reorganizes to more closely resemble the original tissue [17].

A lot of proteins are found within the alpha granules of platelets that strongly influence wound healing process, including transforming growth factor (TGF)-beta, platelet-derived growth factor (PDGF), platelet-derived endothelial growth factor (PDEGF), platelet-derived angiogenesis

Then a flow of monocytes and T lymphocytes occurs to wound area [16, 17, 19, 21].

site. These activities are regarded as the first steps of angiogenesis [16, 17].

types which are required to produce the appropriate tissue type [17].

4. Roles of platelets in wound healing

viability [9, 13–15].

3. Wound healing process

a scaffold for migration and proliferation of cells [18, 20].
