Fibrin-based tissue engineering: comparison of different methods of autologous fibrinogen isolation.

Objective: This study is focussed on the optimal method of autologous fibrinogen isolation with regard to the yield and the use as a scaffold material. This is particularly relevant for pediatric patients with strictly limited volumes of blood. Materials and Methods: The following isolation methods were evaluated: cryoprecipitation, ethanol (EtOH) precipitation, ammonium sulfate [(NH4)2SO4)] precipitation, ammonium sulfate precipitation combined with cryoprecipitation, and polyethylene glycol precipitation combined with cryoprecipitation. Fibrinogen yields were quantified spectrophotometrically and by electrophoretic analyses. To test the influence of the different isolation methods on the microstructure of the fibrin gels, scanning electron microscopy (SEM) was used and the mechanical strength of the cell-free and cell-seeded fibrin gels was tested by burst strength measurements. Cytotoxicity assays were performed to analyze the effect of various fibrinogen isolation methods on proliferation, apoptosis, ...