Wednesday, January 17, 2007
J Orthop Res. 2007 Feb;25(2):230-40. Links
Platelet rich plasma (PRP) enhances anabolic gene expression patterns in flexor digitorum superficialis tendons.
Department of Clinical Sciences, VMC C3-181, Cornell University, Ithaca, New York 14853.
Platelet rich plasma (PRP) has recently been investigated for use in tissue regeneration studies that seek to utilize the numerous growth factors released from platelet alpha-granules. This study examined gene expression patterns, DNA, and collagen content of equine flexor digitorum superficialis tendon (SDFT) explants cultured in media consisting of PRP and other blood products. Blood and bone marrow aspirate (BMA) were collected from horses and processed to obtain plasma, PRP, and platelet poor plasma (PPP). IGF-I, TGF-beta1, and PDGF-BB were quantified in all blood products using ELISA. Tendons were cultured in explant fashion with blood, plasma, PRP, PPP, or BMA at concentrations of 100%, 50%, or 10% in serum-free DMEM with amino acids. Quantitative RT-PCR for expression of collagen type I (COL1A1), collagen type III (COL3A1), cartilage oligomeric matrix protein (COMP), decorin, matrix metalloproteinase-3 (MMP-3), and matrix metalloproteinase-13 (MMP-13) was performed as were DNA and total soluble collagen assays. TGF-beta1 and PDGF-BB concentrations were higher in PRP compared to all other blood products tested. Tendons cultured in 100% PRP showed enhanced gene expression of the matrix molecules COL1A1, COL3A1, and COMP with no concomitant increase in the catabolic molecules MMP-3 and MMP-13. These findings support in vivo investigation of PRP as an autogenous, patient-side treatment for tendonitis. (c) 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:230-240, 2007.
Monday, January 15, 2007
J Bone Joint Surg Am. 2007 Jan;89(1):139-47. Links
Platelet-rich plasma inhibits demineralized bone matrix-induced bone formation in nude mice.Ranly DM, Lohmann CH, Andreacchio D, Boyan BD, Schwartz Z.
It is unclear whether platelet-rich plasma is a clinically effective adjunct to osteoinductive agents such as demineralized bone matrix. It contains platelet-derived growth factor (PDGF), which decreases osteoinduction by human demineralized bone matrix in nude-mouse muscle, suggesting that platelet-rich plasma may also have a negative impact. This study tested the hypothesis that platelet-rich plasma reduces demineralized bone matrix-induced bone formation and that this effect varies with donor-dependent differences in platelet-rich plasma and demineralized bone matrix. Compared with platelet-poor plasma, platelet-rich plasma preparations exhibited a fourfold increase in the platelet count, a fifteenfold increase in the amount of transforming growth factor-beta, a sixfold increase in the amount of PDGF-BB, a fivefold increase in the amount of PDGF-AA, and a twofold increase in the amount of PDGF-AB. Platelet-rich plasma decreased the osteoinductivity of demineralized bone matrix implanted in immunocom-promised mice, and the activities of both demineralized bone matrix and platelet-rich plasma were donor-dependent. CLINICAL RELEVANCE: Platelet-rich plasma may not be an appropriate adjunct to demineralized bone matrix in some clinical applications.
Sunday, January 07, 2007
There is no data on the use of PRP for meniscus surgery so far. Many years ago, isolated meniscus repair was routinely enhanced using a fibrin clot which is similar to PRP. Again, this type of application makes sense but there isn't any solid information concerning its use in this area yet.
Adding PRP to meniscus repairs is best discussed on an individual basis with your surgeon.
Presently, there are no specific human trials using PRP for degenerative disc disease. Theoretical and cell culture evidence does support its use. An article published in the esteemed journal Spine by Akeda et al stated:
"Platelet-rich plasma was effective in stimulating cell proliferation and extracellular matrix metabolism. The response to platelet-rich plasma was greater in the case of anulus fibrosus cells than of nucleus pulposus cells. The local administration of platelet-rich plasma might stimulate intervertebral disc repair. In addition, given the risks of using animal serum for tissue engineering, autologous blood may gain favor as a source of growth factors and serum supplements needed for stimulating cells to engineer intervertebral disc tissues."
Clearly, much more research is needed but the use of PRP for DDD does seem like a reasonable option that may one day be available.
Saturday, January 06, 2007
- In the study outlined below, Platelet Rich Plasma improved nerve repair. Specifically, "the data demonstrated a measurable neurotrophic effect when PRP was present, with the most favorable results seen with PRP added to suture".
This is yet another study that helps us understand how to best use PRP.
Allan Mishra APEX PRP
- Laryngoscope. 2007 Jan;117(1):157-165.
Effect of Platelet Rich Plasma and Fibrin Sealant on Facial Nerve Regeneration in a Rat Model.
OBJECTIVE:: To investigate the effects of platelet rich plasma (PRP) and fibrin sealant (FS) on facial nerve regeneration. STUDY DESIGN:: Prospective, randomized, and controlled animal study. METHODS:: Experiments involved the transection and repair of facial nerve of 49 male adult rats. Seven groups were created dependant on the method of repair: suture; PRP (with/without suture); platelet poor plasma (PPP) (with/without suture); and FS (with/without suture) groups. Each method of repair was applied immediately after the nerve transection. The outcomes measured were: 1) observation of gross recovery of vibrissae movements within 8-week period after nerve transection and repair using a 5-point scale and comparing the left (test) side with the right (control) side; 2) comparisons of facial nerve motor action potentials (MAP) recorded before and 8 weeks after nerve transection and repair, including both the transected and control (untreated) nerves; 3) histologic evaluation of axons counts and the area of the axons. RESULTS:: Vibrissae movement observation: the inclusion of suturing resulted in overall improved outcomes. This was found for comparisons of the suture group with PRP group; PRP with/without suture groups; and PPP with/without suture groups (P < .05). The PRP without suture group had a significantly greater degree of recovery than the PPP without suture group (P < .05), but it did not have better performance than suture group (P > .05). The movement recovery of the suture group was significantly better than the FS group (P = .014). The recovery of function of the PRP groups was better than that of the FS groups, although this did not reach statistical significance (P = .09). Electrophysiologic testing: there was a significantly better performance of the suture group when compared with the PRP and PPP without suture groups in nerve conduction velocity (P < .05). The PRP with suture group had the best results when compared with the suture as well as the PPP with suture groups in duration and latency-2 of MAP (P < .05). For the FS groups, no results were found demonstrating a biological effect. The PRP with suture group demonstrated the best performance in the latency-2 and the area under the curve of MAP when compared with the suture and FS with suture groups (P < .05). Histomorphometric analysis: PRP with suture demonstrated the greatest increase in axon counts when compared with suture, FS with suture, and PPP with suture groups (P < .05). There was no statistically significant difference seen in axon diameter. CONCLUSION:: The best results for the return of function in our rat facial nerve axotomy models occurred when the nerve ends were sutured together. At the same time, the data demonstrated a measurable neurotrophic effect when PRP was present, with the most favorable results seen with PRP added to suture. There was an improved functional outcome with the use of PRP in comparison with FS or no bioactive agents (PPP). FS showed no benefit over conventional suturing in facial nerve regeneration. Our study provides the potential of a new clinical application for PRP in peripheral nerve regeneration.