ABSTRACT
The pharmacokinetics data of phase I/II clinical trials (EudraCT Number: 2005-006186-14) of the new, triple inactivated plasma-derived Kedrion FIX concentrate was designed according to the recommendations of SSC-ISTH [1,2]: 11 post-infusion FIX/time points samples during the first 72 h. The PK data were also analysed by a modified, less dense, 9 FIX/time points, sample design. The outcomes of the safety and efficacy study and the pharmacokinetics' results have been previously and partially described [3,4]. The single-dose PK at enrolment (PK I) and the end of the trial (PK II) were analyzed by WinNonlin 7.0 (Pharsight) and according to three different methods: Non-Compartment Analysis (NCA), One Compartment Method (OCM), and Two-Compartment Method (TCM). The outcomes of PK parameters by TCM show that a higher number of FIX/time concentration points may not always give a better definition of the decay curve. On the other hand, the Terminal HL of NCA is deeply affected by the goodness of the last two-three points. The quite long Kedrion FIX HL may allow for a cost/effective tailoring of prophylaxis in haemophilia B patients.
ABSTRACT
BACKGROUND: Recently, there has been an increased interest in using mesenchymal stromal cells (MSCs) in bone tissue engineering coupled with a suitable scaffold of both biological and synthetic origin. The cells and these constructs can be combined in vitro or directly in vivo to enhance tissue repair. MSCs are spindle-shaped cells capable of self-renewal and can be induced to differentiate mainly into osteo-, chondro-, and adipogenic-progeny types. Several biomaterials are currently available and, among them, fibrin-based constructs seem to be suitable for guiding the cells during tissue repair or regeneration due to their biocompatibility and biodegradability. STUDY DESIGN AND METHODS: Here, this study describes a simple in vitro system using human mesenchymal stromal cells (hMSCs) and fibrin scaffold prepared at different concentrations in fibrinogen (1.5%-3% and 6%) to evaluate cell proliferation and viability inside these constructs. RESULTS: The data demonstrate that the constructs with 3 percent in fibrinogen resulted in the best scaffolds, because within them the cells were able to proliferate and were uniformly distributed. Finally, analyzing the capability of the clots to support osteogenic differentiation of MSCs, we observed that they differentiated into osteoblasts. CONCLUSION: These results suggest that fibrin gel could be useful as a delivery system for hMSCs.
