Enhanced Cell Ingrowth and Proliferation through Three-Dimensional Nanocomposite Scaffolds with Controlled Pore Structures

Abstract

We present enhanced cell ingrowth and proliferation through crosslinked three-dimensional (3D) nanocomposite scaffolds fabricated using poly(propylene fumarate) (PPF) and hydroxyapatite (HA) nanoparticles. Scaffolds with controlled internal pore structures were produced from computer-aided design (CAD) models and solid freeform fabrication (SFF) technique, while those with random pore structures were fabricated by NaCl leaching technique for comparison. The morphology and mechanical properties of scaffolds were characterized using scanning electron microscopy (SEM) and mechanical testing, respectively. Pore interconnectivity of scaffolds was assessed using X-ray micro-computed tomography (micro-CT) and 3D imaging analysis. In vitro cell studies have been performed using MC3T3-E1 mouse preosteoblasts and cultured scaffolds in a rotating-wall-vessel bioreactor for 4 and 7 days to assess cell attachment, viability, ingrowth depth, and proliferation. The mechanical properties of crosslinked nanocomposite scaffolds were not significantly different after adding HA or varying pore structures. However, pore interconnectivity of PPF/HA nanocomposite scaffolds with controlled pore structures has been significantly increased, resulting in enhanced cell ingrowth depth 7 days after cell seeding. Cell attachment and proliferation are also higher in PPF/ HA nanocomposite scaffolds. These results suggest that crosslinked PPF/HA nanocomposite scaffolds with controlled pore structures may lead to promising bone tissue engineering scaffolds with excellent cell proliferation and ingrowth.

Extrusion-based 3D printing of poly(propylene fumarate) scaffolds with hydroxyapatite gradients

“…The compressive modulus for both S-HA 10 % scaffolds with and without SDS was about 50 MPa, which is greater than or comparable to previous reports with 3D printed polymers (20–90 MPa) [34], 3D printed composites (30–100 MPa) [40], and non-porous PPF-HA composites (20–60 MPa [27] and 135–150 MPa [28]). Our S-HA 10 % scaffolds also showed similar porosity and scaffold architecture to PPF-HA composites prepared via STL [47]; however, our results showed an improvement in compressive modulus with extrusion-based printing techniques. After comparing our results to other literature, it is notable that the incorporation of fully interconnected pores does not dramatically compromise mechanical properties, and the scaffolds fabricated in this work would facilitate waste and nutrient transport much more effectively in vitro and in vivo than non-porous composites.…”

Cryotemplation for the rapid fabrication of porous, patternable photopolymerized hydrogels

“…The architecture of hydrogels has been reported to influence cell migration in vitro 56, 57 and infiltration in vivo 58 , and control cellular expression of pro-regenerative signals 59, 60 . We investigated the ability to design porous hydrogels of complex architectures using material templation, photomasking, and fusion of preformed structures, which has been difficult to achieve with more conventional hydrogels 13 .…”

Enhancement of Cell Ingrowth, Proliferation, and Early Differentiation in a Three-Dimensional Silicon Carbide Scaffold Using Low-Intensity Pulsed Ultrasound

“…The final depth of the cell ingrowth in the scaffolds was determined by the offset, which was the total distance traveled from top to bottom, where the cells were occupied. 17 The offset number could be read in the Focus Window. Nine views were chosen for measurement from each sample (n = 3), and because the depths in each of these views varied, the average product was used as the depth for the sample.…”