Preparation of a pure autologous biodegradable fibrin matrix for tissue engineering.
ABSTRACT Parallel to the growing role of tissue engineering, the need for cell embedding materials, which allow cells to stabilise in a three-dimensional distribution, has increased. Although several substances have been tested, fibrin is thus far the only one that permits the clinical application of cultured tissue. To date, autologous fibrinogen has usually been polymerised with bovine thrombin, which can cause severe immunological side effects. The objective of this study was to explore the practicability of obtaining autologous thrombin from a single patient in an adequate concentration and amount. Fibrinogen was cryoprecipitated from 200 ml of freshly-frozen plasma. Thrombin was isolated from the supernatant through ion-exchange chromatography. The thrombin was first bound to Sephadex A-50 and then eluated using 2 ml of a salt buffer (2.0 M NaCl in 0.015 M trisodiumcitrate, pH 7.0). The activity of the thrombin (51 NIH x ml(-1) to 414 NIH x ml(-1) reached levels comparable to those in commercially available fibrin glues (4-500 NIH x ml(-1)). The study has shown that it is possible to obtain a sufficient amount of autologous thrombin from a single donor to create a fibrin matrix of high efficiency without the risk of immunological and infectious side effects.
- [show abstract] [hide abstract]
ABSTRACT: The two-component tissue adhesive system where the one component is a concentrated human fibrinogen solution and the other component is a thrombin solution containing Ca2+ is becoming increasingly important in surgery. In the commercially available tissue adhesive, the fibrinogen is separated from pooled plasma. The risk of transmitting foreign immunogens and viruses, always present when foreign biological materials are used, will be eliminated if the fibrinogen is separated from the patient's own blood. A method using ethanol precipitation is described for preparing a concentrated fibrinogen solution from plasma separated from small amounts of blood. The method is fast, the final product can be obtained within 30-60 min after collection of the blood. The recovery is compared with the recovery obtained by separating the fibrinogen with ammonium sulfate precipitation and with cryoprecipitation. The method using ethanol is by far the most profitable, and the product is evaluated by experimental liver surgery in pigs.European Surgical Research 02/1988; 20(5-6):381-9. · 0.75 Impact Factor
- Acta Haematologica 05/1957; 17(4):237-46. · 0.89 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: To establish a novel 3-dimensional (3-D) in vitro model for the investigation of destructive processes in rheumatoid arthritis (RA). Two distinct culture systems were developed, consisting of RA synovial membrane and articular cartilage explants or interactive RA synovial cell/chondrocyte cultures embedded in 3-D fibrin matrices. The expression of proteolytic enzymes, chondrocyte matrix architecture, and matrix degradation parameters was analyzed by immunohistochemistry. Of 28 RA explant cultures, 16 displayed an invasion of synovial tissue into the cartilage explants, compared with 1 of 8 osteoarthritis explants. The expression of collagenase and vascular cell adhesion molecule 1 could be demonstrated at the cartilage-pannus junction. Of 20 interactive cell cultures, 18 revealed invasive behavior and remained vital for extended periods of time. The models presented allow us to study distinct aspects of destructive joint diseases under in vitro conditions that resemble human pathology. Moreover, our model is able to supplement animal experiments in basic research and drug testing.Arthritis & Rheumatism 09/1997; 40(8):1420-8. · 7.48 Impact Factor