Fibroblasts can condense a hydrated collagen lattice to a tissue-like structure 1/28th the area of the starting gel in 24 hr. The rate of the process can be regulated by varying the protein content of the lattice, the cell number, or the con- centration of an inhibitor such as Colcemid. Fibroblasts of high population doubling level propagated in vitro, which have left the cell cycle, can carry out the contraction at least as efficiently as cycling cells. The potential uses of the system as an immu- nologically tolerated "tissue" for wound hea ing and as a model for studying fibroblast function are discussed.

Production of a tissue-like structure by contraction of collagen lattices by human fibroblasts of different proliferative

Platelet-rich plasma: evidence to support its use

There are a number of ways in which a clinical diagnosis of dementia of the Alzheimer type can be made – the application of clinical criteria is the commonest but ancillary techniques such as neuroima

Clinical Diagnosis of Alzheimer's Disease

https://www.cell.com/trends/biotechnology/pdf/S0167-7799(09)00015-8.pdf

Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF).

Platelets are known for their role in haemostasis where they help prevent blood loss at sites of vascular injury. To do this, they adhere, aggregate and form a procoagulant surface leading to thrombin generation and fibrin formation. Platelets also release substances that promote tissue repair and influence the reactivity of vascular and other blood cells in angiogenesis and inflammation. They contain storage pools of growth factors including PDGF, TGF-β and VEGF as well as cytokines including proteins such as PF4 and CD40L. Chemokines and newly synthesised active metabolites are also released. The fact that platelets secrete growth factors and active metabolites means that their applied use can have a positive influence in clinical situations requiring rapid healing and tissue regeneration.Their administration in fibrin clot or fibrin glue provides an adhesive support that can confine secretion to a chosen site. Additionally, the presentation of growth factors attached to platelets and/or fibrin may result in enhanced activity over recombinant proteins. Dental implant surgery with guided bone regeneration is one situation where an autologous platelet-rich clot clearly accelerates ossification after tooth extraction and/or around titanium implants. The end result is both marked reductions in the time required for implant stabilisation and an improved success rate. Orthopaedic surgery, muscle and/or tendon repair, reversal of skin ulcers, hole repair in eye surgery and cosmetic surgery are other situations where autologous platelets accelerate healing. Our aim is to review these advances and discuss the ways in which platelets may provide such unexpected beneficial therapeutic effects.

Autologous platelets as a source of proteins for healing and tissue regeneration

This article presents preliminary clinical evidence of the beneficial effect of the use of plasma rich in growth factors of autologous origin. The plasma is obtained from the individual patient by plasmapheresis. The macroscopic and microscopic results obtained with bone regeneration using this technique, which uses no membrane or barrier, can be observed. The incorporation of these concepts can introduce several advantages, including the enhancement and acceleration of bone regeneration and more rapid and predictable soft tissue healing.

/pdf/plasma-rich-in-growth-factors-preliminary-results-of-use-in-2zdc45r012.pdf

Plasma rich in growth factors: preliminary results of use in the preparation of future sites for implants.

BackgroundPlatelet-rich fibrin matrices release a natural mixture of growth factors that play central roles in the complex processes of tendon healing.HypothesisApplication of autologous platelet-rich matrices during Achilles tendon surgery may promote healing and functional recovery.Study DesignCase-control study and descriptive laboratory study; Level of evidence, 3.MethodsTwelve athletes underwent open suture repair after complete Achilles tendon tear. Open suture repair in conjunction with a preparation rich in growth factors (PRGF) was performed in 6 athletes and retrospectively compared with a matched group that followed conventional surgical procedure. The outcomes were evaluated on the basis of range of motion, functional recovery, and complications. Achilles tendons were examined by ultrasound at 50 ± 11 months in retrospective controls and 32 ± 10 months in the PRGF group. In the laboratory portion of the study, PRGF treatment was characterized by the number of platelets and concentration of ins...

/pdf/comparison-of-surgically-repaired-achilles-tendon-tears-1vkk8nsrbz.pdf

Comparison of Surgically Repaired Achilles Tendon Tears Using Platelet-Rich Fibrin Matrices

http://www.falloplastica.net/fp/pdf/prp03.pdf

Autologous preparations rich in growth factors promote proliferation and induce VEGF and HGF production by human tendon cells in culture.

http://biosscelulasmadre.com/wp-content/uploads/2015/04/New-insights-into-and-novel-applications-for-platelet-rich-fibrin-therapies.pdf

Eduardo Anitua

Papers

Autologous platelets as a source of proteins for healing and tissue regeneration

Plasma rich in growth factors: preliminary results of use in the preparation of future sites for implants.

Comparison of Surgically Repaired Achilles Tendon Tears Using Platelet-Rich Fibrin Matrices

Autologous preparations rich in growth factors promote proliferation and induce VEGF and HGF production by human tendon cells in culture.

New insights into and novel applications for platelet-rich fibrin therapies