Sulfated carboxymethyl cellulose and carboxymethyl κ-carrageenan immobilization on 3D-printed poly-ε-caprolactone scaffolds differentially promote pre-osteoblast proliferation and osteogenic activity

Abstract

The lack of bioactivity in three-dimensional (3D)-printing of poly-є-caprolactone (PCL) scaffolds limits cell-material interactions in bone tissue engineering. This constraint can be overcome by surface-functionalization using glycosaminoglycan-like anionic polysaccharides, e.g., carboxymethyl cellulose (CMC), a plant-based carboxymethylated, unsulfated polysaccharide, and κ-carrageenan, a seaweed-derived sulfated, non-carboxymethylated polysaccharide. The sulfation of CMC and carboxymethylation of κ-carrageenan critically improve their bioactivity. However, whether sulfated carboxymethyl cellulose (SCMC) and carboxymethyl κ-carrageenan (CM-κ-Car) affect the osteogenic differentiation potential of pre-osteoblasts on 3D-scaffolds is still unknown. Here, we aimed to assess the effects of surface-functionalization by SCMC or CM-κ-Car on the physicochemical and mechanical properties of 3D-printed PCL scaffolds, as well as the osteogenic response of pre-osteoblasts. MC3T3-E1 pre-osteoblasts were seeded on 3D-printed PCL scaffolds that were functionalized by CM-κ-Car (PCL/CM-κ-Car) or SCMC (PCL/SCMC), cultured up to 28 days. The scaffolds’ physicochemical and mechanical properties and pre-osteoblast function were assessed experimentally and by finite element (FE) modeling. We found that the surface-functionalization by SCMC and CM-κ-Car did not change the scaffold geometry and structure but decreased the elastic modulus. Furthermore, the scaffold surface roughness and hardness increased and the scaffold became more hydrophilic. The FE modeling results implied resilience up to 2% compression strain, which was below the yield stress for all scaffolds. Surface-functionalization by SCMC decreased Runx2 and Dmp1 expression, while surface-functionalization by CM-κ-Car increased Cox2 expression at day 1. Surface-functionalization by SCMC most strongly enhanced pre-osteoblast proliferation and collagen production, while CM-κ-Car most significantly increased alkaline phosphatase activity and mineralization after 28 days. In conclusion, surface-functionalization by SCMC or CM-κ-Car of 3D-printed PCL-scaffolds enhanced pre-osteoblast proliferation and osteogenic activity, likely due to increased surface roughness and hydrophilicity. Surface-functionalization by SCMC most strongly enhanced cell proliferation, while CM-κ-Car most significantly promoted osteogenic activity, suggesting that surface-functionalization by CM-κ-Car may be more promising, especially in the short-term, for in vivo bone formation.

Carboxymethylated and Sulfated Furcellaran from Furcellaria lumbricalis and Its Immobilization on PLA Scaffolds

“…Following sulfation ( Figure 4 b), a novel absorption band emerged at 820 cm −1 (C–O–S stretching), indicating galactose-6-sulfate, and the intensity of the absorption band at 1220 cm −1 markedly increased [ 38 ]. The confirmation of carboxymethylated FUR, as depicted in Figure 4 c, was validated by the emergence of a band at 1597 cm −1 (–COO−), associated with the stretching vibration of the asymmetric carboxyl group, a band at 1417 cm −1 related to the symmetric C–O stretching of the carboxyl group, and a scissoring vibration of the methylene group at 1329 cm −1 [ 34 , 39 ].…”

“…Confirmation of surface functionalization by SF and CMF was established through an increase in the percentage of sulfur and nitrogen on the surfaces of PLA-SF and PLA-CMF. Oxygen concentration of PLA-CMF was slightly higher compared to PLA-SF scaffolds, indicating the presence of more carboxymethyl groups [ 39 ]. The higher nitrogen content (1.4%) in PLA-SF compared to PLA-CMF may stem from both plasma treatment and pyridine originated from the sulfation.…”

3D printing of bone and cartilage with polymer materials

“…The conductive materials usually printed in 3D are made based on non-metallic 3D printing technology on the thin film base ( Abbasi-Ravasjani et al, 2022 ). The appropriate 3D printing technology, dispersed liquid or conductive elastic composite material of the conductive filler, could be chosen for the flexible base to obtain the circuit pattern and the required conductive material and device ( Abbasi-Ravasjani et al, 2022 ).…”

“…The conductive materials usually printed in 3D are made based on non-metallic 3D printing technology on the thin film base ( Abbasi-Ravasjani et al, 2022 ). The appropriate 3D printing technology, dispersed liquid or conductive elastic composite material of the conductive filler, could be chosen for the flexible base to obtain the circuit pattern and the required conductive material and device ( Abbasi-Ravasjani et al, 2022 ). The 3D printing technology involved in the manufacturing of conductive materials mainly includes melting deposition (FDM), electric field-driven spray deposition (E-JET), polymer injection molding (Polyjet), direct ink writing (DIW), stereo light carvings (SLA) ( Abbasi-Ravasjani et al, 2022 ; Andjela et al, 2022 ; Ding et al, 2022 ).…”

“…The appropriate 3D printing technology, dispersed liquid or conductive elastic composite material of the conductive filler, could be chosen for the flexible base to obtain the circuit pattern and the required conductive material and device ( Abbasi-Ravasjani et al, 2022 ). The 3D printing technology involved in the manufacturing of conductive materials mainly includes melting deposition (FDM), electric field-driven spray deposition (E-JET), polymer injection molding (Polyjet), direct ink writing (DIW), stereo light carvings (SLA) ( Abbasi-Ravasjani et al, 2022 ; Andjela et al, 2022 ; Ding et al, 2022 ). According to the characteristics of the material, the appropriate 3D printing technology can be selected to manufacture the conductive material.…”