%0 Journal Article
%T Platelet-Rich Plasma Peptides: Key for Regeneration
%A Dolores Javier S¨˘nchez-Gonz¨˘lez
%A Enrique M¨Śndez-Bolaina
%A Nayeli Isabel Trejo-Bahena
%J International Journal of Peptides
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/532519
%X Platelet-derived Growth Factors (GFs) are biologically active peptides that enhance tissue repair mechanisms such as angiogenesis, extracellular matrix remodeling, and cellular effects as stem cells recruitment, chemotaxis, cell proliferation, and differentiation. Platelet-rich plasma (PRP) is used in a variety of clinical applications, based on the premise that higher GF content should promote better healing. Platelet derivatives represent a promising therapeutic modality, offering opportunities for treatment of wounds, ulcers, soft-tissue injuries, and various other applications in cell therapy. PRP can be combined with cell-based therapies such as adipose-derived stem cells, regenerative cell therapy, and transfer factors therapy. This paper describes the biological background of the platelet-derived substances and their potential use in regenerative medicine. 1. Introduction Platelets are nonnuclear cellular fragments derived from megakaryocytes in the bone marrow; they are specialized secretory elements that release the contents of their intracellular granules in response to activation. They were discovered by Bizzozero in the 19th century [1] and after Wright observed that megakaryocytes are platelet precursors [2]. Actually we know that platelets synthesize proteins and that pattern of peptides synthesis changes in response to cellular activation [3]. Platelets contain a great variety of proteins molecules, among which are the high presence of signaling, membrane proteins, protein processing, cytoskeleton regulatory proteins, cytokines, and other bioactive peptides that initiate and regulate basic aspects of wound healing [3]. It is known, through efforts such as the platelet proteome project, that more than 300 proteins are released by human platelets in response to thrombin activation [4]. Proteome platelet includes 190 membrane-associated and 262 phosphorylated proteins, which were identified via independent proteomic and phospho proteomic profiling [5]. When platelets fall precipitously below critical levels (usually under 10,000 to 20,000 per cubic millimeter), molecular disassembly opens the zippers formed by adjacent intercellular endothelial junctions, causing extravasation of erythrocytes into the surrounding tissues. In addition to their well-known function in hemostasis, platelets also release substances that promote tissue repair, angiogenesis, and inflammation [6]. Furthermore, they induce the migration and adherence of bone-marrow-derived cells to sites of angiogenesis; platelets also induce differentiation of endothelial-cell
%U http://www.hindawi.com/journals/ijpep/2012/532519/