Biocompatibility of layer-by-layer structured silk fibroin/chitosan nanofibers serving as cardiac patches

AIM To investigate the biocompatibility of the synthesized silk fibroin(SF)/chitosan (CS) nanofibers with adipose tissue-derived mesenchymal stem cells (AD-MSCs) and the feasibility of nanofibers serving as cardiac patches. METHODS Cellulose nanofibers were fabricated by electrospinning and layer-by-layer (LBL) coated with SF and CS. Nanofibers characteristics were analyzed by ζ-potentials and X-ray photoelectron spectroscopy (XPS). AD-MSCs were constitutively expressed. Both firefly luciferase (Fluc) and green fluorescent protein (GFP) were isolated from Fluc-GFP transgenic mice and co-cultured with SF/CS nanofibrous membrane for 24 h. Cellular morphology and microstructure were observed using confocal microscopy (CFM) and scanning electron microscope (SEM). The linear relationship of the bioluminescent intensity and AD-MSCs count was detected using bioluminescence imaging (BLI) to assess the number of seeded cells. Cell viability was measured by MTT assay. RESULTS XPS displayed the alteration of surface element composition of the mats during LBL coating process. SEM showed that cellulose nanofibers and LBL structured nanofibers displayed porous and uniform nanofibrous 3D microstructures. The survival ratio, spread level and pseudopods of cells on SF/CS nanofibrous membrane were superior to those on cellulose nanofibrous mat. Results of CFM, BLI and MTT revealed cellular proliferation activity and 3D distribution of AD-MSC on SF/CS nanofibers. CONCLUSION Cellulose nanofibers LBL coated by SF and CS have improved biocompatibility.The application of nanofibers could promote cellular proliferation and 3D distribution of seeded AD-MSCs. LBL structured SF/CS nanofibers are ideal biomaterial materials for tissue-engineered cardiac patches.