15502-m-pleumeekers

RESULTS Production and morphological characterization of bilayer BNC scaffolds Figure 1. Fabrication and purification process of bilayer BNC scaffolds composed of a dense nanocellulose layer joined with a macroporous composite layer. BNC hydrogel disks with cellulose content of 17% (i.e. dense layer) were produced by compression, whereas BNC/alginate composite scaffolds (i.e. porous layer) were fabricated by a freeze-drying process. A novel cellulose solvent system (i.e. ionic liquid EMIMAc) was used to achieve a strong interfacial molecular bonding between the dense and porous layers. The bilayer BNC scaffolds were then washed with endotoxin-free water for 14 days to yield non-pyrogenic and non-cytotoxic scaffolds. Bilayer BNC scaffolds, composed of a dense nanocellulose layer joined with a macroporous composite layer of nanocellulose and alginate, were successfully fabricated. (Figures 1 and 2) The dense and porous layers were stable and firmly attached, which facilitated the handling of the scaffolds during the purification process and throughout the study. SEM images revealed a compact BNC network structure in the dense layer and a macroporous structure in the porous layer. However, information about the pore size distribution was not possible to extract from these images (Figure 2B, C). Scanning and reconstruction with microCT of the micro- and macro-structures of the porous layer allowed computation of the 3D morphometric parameters by distance transformation. The Sc.Po, Pore.Th, Wall.Th andWall.N of a typical porous layer of a BNC bilayer scaffold was 75%, 50 ± 25 µm, 18 ± 10 µm and 21 mm -1 , respectively. (Figure 2F, G) 159 NOVEL BILAYER BNC: AN ECM-INSPIRED SCAFFOLD 8