(150k) Surface and Sub-Surface Analyses of Electrospun Gelatin and Gelatin-Chondroitin Sulfate Scaffolds for Biological Applications

The extracellular matrix (ECM) is composed of several components such as collagen, elastin, and glycosaminoglycans. To leverage the interactions with ECM components and mimic ECM composition, fibrous gelatin scaffolds suitable for animal cell culture were synthesized using electrospinning. Gelatin, which is denatured collagen, can be more easily processed than collagen. To examine the interactions between gelatin and glycosaminoglycans in ECM, 10 wt% chondroitin sulfate with 90 wt% gelatin were mixed before making electrospun gelatin-chondroitin sulfate (CS) scaffolds. Scanning electron microscopy images revealed that the fiber diameter of electrospun gelatin and gelatin-CS scaffolds was 3.7±1.1 and 3.0±0.4 µm, respectively. In this study, time-of-flight secondary ion mass spectrometry was applied for surface and sub-surface chemical imaging of both electrospun scaffolds. Total ion images indicated that gelatin fibers were homogeneously distributed with different sizes of pores observed for electrospun gelatin and gelatin-CS scaffolds. From characteristic mass fragment distribution maps for gelatin, we found that the distribution of gelatin components had a homogeneous surface distribution of gelatin components in fibers for both electrospun scaffolds. With depth profiling, gelatin concentration increased with depths and remained homogeneous distribution in fibers for both electrospun scaffolds. From characteristic mass fragment distribution maps for CS, we found that CS was homogeneously mixed with gelatin on the surface. With depth profiling, the concentration of CS component exponentially/dramatically decreased with depths in an electrospun gelatin-CS scaffold. In an electrospun gelatin-CS scaffold, CS distribution tends to correlate positively with gelatin distribution. Such findings on the deposition of the scaffold components on the surface and sub-surfaces are crucial for tissue culture and tissue engineering or regeneration applications.