The Regenerative Marriage Between High-Density Platelet-Rich Plasma and Adipose Tissue

Abstract

The use of autologous biological preparations (ABPs) and their combinations fills the void in healthcare treatment options that exists between surgical procedures, like plastic reconstructive, cosmetic, and orthopedic surgeries; non-surgical musculoskeletal biological procedures; and current pharmaceutical treatments. ABPs, including high-density platelet-rich plasma (HD-PRP), bone marrow aspirate concentrates (BMACs), and adipose tissue preparations, with their unique stromal vascular fractions (SVFs), can play important roles in tissue regeneration and repair processes. They can be easily and safely prepared at the point of care. Healthcare professionals can employ ABPs to mimic the classical wound healing cascade, initiate the angiogenesis cascade, and induce tissue regenerative pathways, aiming to restore the integrity and function of damaged tissues. In this review, we will address combining autologous HD-PRP with adipose tissue, in particular the tissue stromal vascular fraction (t-SVF), as we believe that this biocellular combination demonstrates a synergistic effect, where the HD-PRP constituents enhance the regenerative potential of t-SVF and its adipose-derived mesenchymal stem cells (AD-MSCs) and pericytes, leading to improved functional tissue repair, tissue regeneration, and wound healing in variety of clinical applications. We will address some relevant platelet bio-physiological aspects, since these properties contribute to the synergistic effects of combining HD-PRP with t-SVF, promoting overall better outcomes in chronic inflammatory conditions, soft tissue repair, and tissue rejuvenation.

Keywords: adipose-derived mesenchymal stem cells; autologous platelet exosomes; high-density platelet-rich plasma; tissue repair; tissue stromal vascular fraction.

Figure 2

Electron microscopic image (JEOL-2000FX transmission electron microscope) of intact non-activated human PRP platelets (magnification ×7000). The blue lines mark a single platelet in a vial of PRP. The magnification of a single platelet reveals the three platelet granular structures. Adapted and modified from [45]. Abbreviations: ɑ: alpha-granules; DG: dense granules; L: lysosomes.

Figure 1

Overview of classical and angiogenesis healing cascades.

Figure 3

Graphical representation of an activated platelet releasing its granular content. Agonists like thrombin, ADP, and collagen activate non-activated platelets in HD-PRP. As a result, all three types of platelet granules release their stored molecules, such as growth factors, chemokines, cytokines, adhesion proteins, and EVs, along with the cargo contained within the platelet microvesicles and exosomes. Adapted and modified from Everts et al. [42]. Abbreviations: PLT-EXOs: platelet exosomes; EV: extracellular vesicle; TGF: transforming growth factor; VEGF: vascular endothelial growth factor; SDF: stromal cell-derived factor; ADP: adenosine phosphate; 5-HT: serotonin; PGDF: platelet-derived growth factor; EFG: epidermal growth factor; b-FGF: basic fibroblast growth factor; CTGF: connective tissue growth factor; PMP: platelet microparticles; IL-8: interleukin-8; Ang: angiopoietin.

Figure 4

Graphic representation of t-SVF cellular content. t-SVF comprises a heterogenous cell population extracted from adipose tissue, containing a mix of different cell types, including highly proliferative adipose stem/progenitor cells.

Figure 5

Mechanical emulsification using a 2.4 mm restraining adaptor (Tulip^® Medical, San Diego CA, USA).

Figure 6

Mixing a high volume of HD-PRP (leukocyte-rich preparation) with a high volume of partially emulsified adipose tissue for a plastic reconstructive procedure.

Figure 7

HD-PRP mixed with t-SVF serving as a biocellular graft. In (A), the combined biocellular graft is injected in the wound edges of a chronic venous lower extremity ulcer. In (B), the HD-PRP and t-SVF mixture is injected in the scalp to stimulate hair growth in a patient suffering from alopecia errata.