PEER-REVIEW | FACIAL AESTHETICS |
to growth factors in PRP. These transmembrane
receptors in turn induce an activation of an endogenous internal signal protein, which causes the expression of (unlocks) a normal gene sequence of the cell such as cellular proliferation, matrix formation, osteoid production, and collagen synthesis. The significance of this is that the PRP growth factors never enter the cell or its nucleus, are not mutagenic, and act through the stimulation of normal healing, but much faster. Therefore, PRP has no ability to induce tumour formation and has never been found to do so22, 23
.
Platelet concentration PRP must be developed in an anti-coagulated state and should be used on the graft, flap, wound, or skin within 10 minutes of clot initiation. There is a dose–response relationship between platelet concentration and the proliferation of human adult mesenchymal stem cells, the proliferation of fibroblasts, and the production of type I collagen24, 25
. This suggests that the application of
autologous PRP can enhance wound healing, as has been demonstrated in controlled animal studies for both soft and hard tissues26, 27
. The next question, therefore, concerns how many
platelets are enough. A sufficient cellular response to platelet concentrations first began when a 4- to 5-fold increase over baseline platelet numbers was achieved24 Lui and al25
. A similar study by showed that fibroblast
often more expensive. For example, in Korea it is possible to carry out a half-face study, which is not possible in the UK, and in Italy, the process can be performed only in a clinic/hospital with a haematologist on site.
Literature review When using PRP, the different methods used during preparation are important as they influence the quality of the product. Activation of the platelets is required for the release and enmeshment of growth factors, but the method of activation may influence the resulting matrix, growth factor availability, and healing28
. Furthermore,
some methods enrich leukocytes as well as platelets, but others are designed to be leukocyte-poor. Leukocytes have many important roles in healing and their inclusion in PRP results in increased platelet concentrations. Generally, TGF-ß1 and PDGF levels are higher in preparations that contain leukocytes compared with leukocyte-poor PRP28
.
The literature published between March 2001 and March 2011 was reviewed by Davis et al29
, and the
PRP must be developed in an anti-coagulated state and
proliferation and type I collagen production were also enhanced by increasing platelet concentrations and that much of the response was pH-dependent, with the best responses occurring at more acidic pH levels. PRP is rapidly gaining a lot of interest worldwide, but
10 minutes of clot initiation.
health regulations differ from country to country, making the generalisation of the process more complicated and
meta-analysis of chronic wound studies revealed that PRP therapy is favoured for complete healing. This systematic review in cutaneous wounds showed complete and partial wound healing was improved compared with control wound care. Within the eligible studies, three main types of
should be used on the graft, flap, wound, or skin within
wounds were identified and treated with PRP: open and chronic wounds, acute surgical wounds with primary closure, and acute surgical wounds with secondary closure30, 31
. The primary
outcome assessed in this systematic review was complete healing32
wound studies, complete wound closure was
more likely in wounds treated with PRP therapy. Another review concluded that the percentage of total healing in PRP-treated skin ulcers consistently increased
Figure 1 Benefits reported in the healing cascade Healing
cascade with APC+
Normal healing cascade
HAEMOSTASIS INFLAMMATION REGENERATION REMODELLING
Plasma platelets Fibrin VWF Fibrinogen
Leukocytes inflammatory factors PDGF PF-4 ß-TG
RANTES CD40L
36 ❚
Chemiotactic factors Growth factors TGF ß1 TGF ß2 EGF VEGF IGF
Differentiation factors 3D Matrix Secondary factors
Body’s
response to tissue injury (time)
. In both chronic and acute
June 2013 |
prime-journal.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84