Results show that

the ePTFE membrane had a degree of crystallinity of 59% and that this did not significantly change after grafting indicating that grafting occurs in the amorphous regions. SEM images showed a globular surface morphology for the grafted membranes. XPS was used to evaluate the chemical structure of the graft copolymer and to determine the XPS grafting extent using the C-F (ePTFE membrane) and the C-C (MOEP graft copolymer) peaks. The graft yield as well as grafting extent was found to increase with increasing monomer concentration. Concomitantly, the contact angle was found to decrease with increasing monomer concentration. No direct correlation was found between XI’S grafting extent and the

advancing water contact angle illustrating that the former does not adequately give an indication of the copolymer surface coverage of the first molecular layer. (C) 2010 Wiley AZD0530 order Periodicals, Inc. J Appl Polym Sci 117: 3331-3339, 2010″
“Objectives. The objective of this study was to analyze the effects of Choukroun’s PRF (platelet-rich fibrin), a leucocyte and platelet concentrate clinically usable as fibrin membrane or clot, on human primary cultures of gingival fibroblasts, dermal prekeratinocytes, preadipocytes, and maxillofacial osteoblasts.

Study design. For the proliferation study, these cells were cultivated with or without a PRF membrane originating from the same donor as for the cells. For osteoblasts and fibroblasts, dose-dependent effect C59 wnt was assessed (using 2 membranes). Cell counts and cytotoxicity tests were performed at 3, 7, 14, and 21 days, and even 28 days for osteoblasts. More osteoblast cultures were prepared in differentiation conditions according to

3 modalities (without PRF, with PRF, with PRF the first day and differentiation medium applied only after the first week of culture). Osteoblast differentiation was analyzed using Von Kossa A1155463 staining and alkaline phosphatase, DNA and total cell proteins dosage.

Results. PRF induced a significant and continuous stimulation of proliferation in all cell types. It was dose dependent during all the experiment with osteoblasts, but only on day 14 with fibroblasts. Moreover, PRF induced a strong differentiation in the osteoblasts, whatever the culture conditions. The analysis of osteoblast cultures in differentiation conditions with PRF, using light and scanning electron microscopy, revealed a starting mineralization process in the PRF membrane itself after 14 days. Moreover, PRF leucocytes seemed to proliferate and interact with osteoblasts.

Conclusions. Cultures with PRF are always cocultures with leucocytes. These “”chaperone leucocytes”" could be the source of differential geographic regulation within the culture and explain the double contradictory effect proliferation/differentiation observed on osteoblasts.