Magnetically Multilayer Polysaccharide Membranes for Biomedical Applications

Self-standing nanocomposite films based on biopolymers and functional nanostructures have been widely used due to their potential applications as active elements in biomedical devices. The coupling between chitosan (CHI) and alginate (ALG) multilayered films and magnetic nanoparticles (MNPs) allowed to fabricate magnetic responsive freestanding membranes with a high structural control along the thickness, using the layer-by-layer (LbL) methodology. The mechanical characterization evidenced a trend for an increase of both Young modulus, and ultimate tensile strength with the inclusion of MNPs, or by cross-linking with genipin. Additionally, the multilayered membranes exhibited shape memory properties triggered by hydration. The in vitro biological performance studies showed that cells were more viable and adherent with higher proliferation rates when MNPs were included in the membranes. Our results suggested the potential of the developed magneto-active freestanding membranes for biomedical applications, such as in tissue engineering and biomedical applications

Magnetically Multilayer Polysaccharide Membranes for Biomedical Applications

Self-standing nanocomposite films based on biopolymers and functional nanostructures have been widely used due to their potential applications as active elements in biomedical devices. The coupling between chitosan (CHI) and alginate (ALG) multilayered films and magnetic nanoparticles (MNPs) allowed to fabricate magnetic responsive freestanding membranes with a high structural control along the thickness, using the layer-by-layer (LbL) methodology. The mechanical characterization evidenced a trend for an increase of both Young modulus, and ultimate tensile strength with the inclusion of MNPs, or by cross-linking with genipin. Additionally, the multilayered membranes exhibited shape memory properties triggered by hydration. The in vitro biological performance studies showed that cells were more viable and adherent with higher proliferation rates when MNPs were included in the membranes. Our results suggested the potential of the developed magneto-active freestanding membranes for biomedical applications, such as in tissue engineering and biomedical applications

Physicochemical characterization of scaffolds.

<p>A) FTIR measurements of CHT/CS scaffolds and pure polysaccharides (CHT and CS), B) Swelling test up to 3 days (The inset graphic expands the water uptake for the first 5 hours), C) Weight loss of the scaffolds in PBS (▴) and in an enzymatic solution at 37°C (▪).</p

Histological cross-sections of scaffolds seeded with BCH and hMSCs stained by H&E and Alcian blue at different days of culture in differentiation medium.

<p>Histological cross-sections of scaffolds seeded with BCH and hMSCs stained by H&E and Alcian blue at different days of culture in differentiation medium.</p

DNA assay on the scaffolds seeded with BCH and hMSCs in differentiation medium.

<p>Significant differences between each cell type at different time points were found for p<0.05(*) and p<0.01(**).</p

Variations of (A) Storage modulus (E') and (b) loss factor (tanδ) of the CHT/CS scaffolds obtained by LbL methodology.

<p>Experiments are reported for dry samples (▪) and hydrated samples in PBS at 37°C (•).</p

Scaffold characterization.

<p>A) Production steps of scaffolds: LbL and leaching of free-packet paraffin spheres, B)Digital photograph of the scaffold after all the steps C) Optical Microscopy image of the scaffolds after the leaching of the core material, D, E) SEM micrographs of cross-sections (two different magnifications) and Histological cross-sections of the scaffolds after staining with alcian blue (F) and eosin (G).</p

Live/dead assay, MTT assay and cross-section SEM micrographs of BCH seeded on scaffold at day 1(A, B, C), 3(D, E, F), 14 (G, H, I) and 21(J, K, L) of culture in proliferation medium.

<p>Live/dead assay, MTT assay and cross-section SEM micrographs of BCH seeded on scaffold at day 1(A, B, C), 3(D, E, F), 14 (G, H, I) and 21(J, K, L) of culture in proliferation medium.</p