Nanofibrous Membranes Based on Collagen and Conductive Polymers with Perspective for Biological Applications

Abstract

In this study, membranes of collagen-chitosan (C-Ch) in combination with conductive polymers (CPs) such as polyaniline (Pani) and polypyrrole (Ppy) were obtained by electrospinning using non-toxic solvents such as PBS and ethanol. The change in the morphology after swelling was observed by SEM, while an FTIR analysis showed specific interactions between C-Ch and CP. Mechanical tests showed that C-Ch/Ppy exhibited more elastic behavior and a better stress distribution compared to C-Ch/Pani. The diffusion of Na⁺ and Ca²⁺ ions through the membranes was evaluated and showed a greater resistance for Ca²⁺ in both membrane types. Preliminary biocompatibility testing with H9C2 cells showed a successful cell adhesion to the membranes. These results emphasize the potential of C-Ch/Pani composites for electrically active scaffolds and of C-Ch/PPy composites for applications in mechanically dynamic tissue-specific regeneration.

Keywords: collagen fibers; electrospinning technique; polyaniline; polypyrrole.

Figure 1

(a) FTIR spectra showing intermolecular interactions between collagen (C) and chitosan (Ch) due to hydrogen bonding via amine and hydroxyl functional groups. (b) FTIR spectra of C-Ch membranes with Ppy indicating a shift in the secondary amine region. (c) C-Ch membranes in combination with Pani show no significant spectral shifts, suggesting minimal interactions.

Figure 2

SEM images of the dried membranes of (a) C-Ch, (c) C-Ch/Pani and (e) C-Ch/Ppy as well as the membranes after wetting of (b) C-Ch, (d) C-Ch/Pani and (f) C-Ch/Ppy, showing the loss of morphology due to swelling.

Figure 3

The stress–strain curve of the membranes of the precursors (C-Ch) and C-Ch/Pani, which show a typical plastic behavior; C-Ch/Ppy, on the other hand, shows an elastomeric curve.

Figure 4

(a) Impedance using calcium (fill symbols) and sodium (symbols with border) and (b) Bode impedance using calcium (solid lines) and sodium (dashed lines).

Figure 5

(a) The evaluation of the cell viability of membranes assessed after 1 and 3 days in contact with myoblasts H9c2 (n = 3) using a two-way ANOVA where * indicates statistical significance difference, and the standard error was plotted. (b) The fluorescence of the cytoskeleton after 1 day of the control sample. In the cells with (c) C-Ch/Pani and (d) C-Ch/Ppy; the blue fluorescence is due to the membrane.