Cell migration of preosteoblast cells on a clinical gelatin sponge for 3D bone tissue engineering

Abstract

Using three-dimensional (3D) bone engineering to fabricate bone segments is a better choice for repairing bone defects than using autologous bone. However, biomaterials for bone engineering are burdened with some clinical safety concerns. In this study, we layered commonly found clinical materials, hemostatic gelatin sponges, in a novel manner to create a 3D scaffold for bone engineering purposes. We further examined the comparable benefits of our design with both closed- and open-bottom holders. Cells in stacked layer disc systems were examined after a week of growth and differentiation. Osteoblasts in the outer layers of both closed- and open-bottom holder systems displayed gradually increased alkaline phosphatase (ALP) activity but decreased osteopontin (OPN) expression. Further, cell proliferation assays and LIVE/DEAD staining revealed decreased viable cell counts in the top layer with increased incubation time. However, while layered disc systems with closed-bottom holders underwent differentiation, they kept more differentiated cells alive within the gelatin sponge disc scaffold after 28 d of culturing. Whether cells were inoculated into the top, middle, or bottom portions of the layered disc stack, osteoblasts showed a preference for migrating to the top layer, in keeping with the oxygen and nutrients gradients. Regarding practical application, this study offers valuable information to promote the use of hemostatic gelatin sponges for bone engineering.

Monocarboxylate transporter 1-mediated lactate accumulation promotes nucleus pulposus degeneration under hypoxia in a 3D multilayered nucleus pulposus degeneration model

“…Since a single scaffold (1 mm) is not thin enough for nutrient and oxygen diffusion, after multilayered construction, an oxygen gradient within 5-layered gelatine sponge was obviously formed and cell behaviours (including cell viability and gene expression profile) were changed inside the construct. In a previous study, aerobic pre-osteoblast cells cultured on the bottom layer migrated to the top layer (Wang et al, 2019). However, low-oxygenrequiring NP cells would migrate to the bottom layer (data not shown).…”

“…Previous studies have shown that gradients of oxygen and nutrient concentrations exist within a 3D multilayered culture, similar to the microenvironmental changes observed during NP degeneration (Bettahalli al., 2014;Derda et al, 2009;Wang et al, 2019). It has not been shown whether the 3D multilayered culture model can mimic the progress of NPD.…”

Surface Tailoring of 3D Scaffolds to Promote Osteogenic Differentiation

“…Preosteoblasts were observed to form cell bridges between adjacent rods by employing the long filopodia and sheet-like lamellipodia (Figure ). In contrast to the limited preosteoblast migration to the bottom of the multilayered scaffolds, preosteoblasts in the nanoapatite-PMDE-scaffold showed autonomous cell migration from the top to the bottom. This phenomenon suggested that the mass transport of oxygen and nutrients within the nanoapatite-PMDE-scaffold was efficient to support the cellular activities of preosteoblasts, which resulted in high levels of oxygen and nutrients throughout the scaffold instead of being restricted at the top .…”

“…The preosteoblasts were preferentially aligned along the rods, suggesting that the cells were able to recognize the biophysical cues in the microenvironment and coordinate their behaviors. Substrate anisotropy provides an important cue to direct cellular orientation, , and preosteoblasts were reported to align along the fibers in polystyrene scaffolds coated with growth factors . In the nanoapatite-PMDE-scaffold, the combination of rod alignment with the polyelectrolyte and nanoapatite modification provides an effective approach to spatially control cell alignment and proliferation without involving growth factors.…”

PEG Reinforced Scaffold Promotes Uniform Distribution of Human MSC-Created Cartilage Matrix

“…Since we also noticed fewer cells in the central area of GH than in GH+PEG, we next examined if cell migration is one mechanism resulting in the difference in GAG deposition. Previously, it had been reported that MSCs could migrate in hyaluronic acid [ 19 ] and gelatin [ 20 ]-based scaffolds. However, in the method that we used in this study to assess cell migration, we did not see MSCs that crossed from ring to disc or vice versa.…”