CNT incorporation improves the resolution and stability of porous 3D printed PLGA/HA/CNT scaffolds for bone regeneration

Abstract

In this study, 3D printed porous poly(lactide-co-glycolide) (PLGA) and its nanocomposites with 5 wt. % hydroxyapatite (HA) and 0.5, 1 and 2 wt. % multi-walled carbon nanotubes (MWCNT) scaffolds were fabricated by using extrusion-based printing. The printing parameters were optimized by rheological studies. The rheological studies demonstrated shear thinning properties for all compositions and an increase in storage modulus was observed after the addition of MWCNT. Porous PLGA/HA/MWCNT scaffolds were printed by applying a pressure of 4.76 bar at 125 ⁰C. The addition of 0.5 wt. % of MWCNT reduced the strut size and increased the porosity from 42% to 60%. The increase of storage modulus and decrease of strut size was related to hydrogen bonding between MWCNT, HA and PLGA which ultimately improved shape fidelity. The scaffolds were characterized by analysis of their chemical structure, water contact angle measurement, in vitro bioactivity test, biodegradation test, mechanical analysis, and in vitro cell studies. The scaffolds were found to be more hydrophilic by the incorporation of MWCNTs. Also, degradation studies showed that the microstructure of the scaffold became more stable with the addition of HA and MWCNT. The compressive modulus of PLGA/HA/CNT2 scaffold was found to be 548.5 MPa which is found suitable to replace cancellous bone. The scaffolds were found highly biocompatible which is possibly due to alignment of MWCNT and PLGA during 3D printing process. Alizarin red staining indicated improvement of mineralization of MC3T3-E1 cells on the MWCNT incorporated porous 3D scaffolds. The results suggest that the produced porous 3D printed PLGA/HA/MWCNT scaffolds are promising for bone regeneration applications.

Three-Dimensional Printing of Multifunctional Composites: Fabrication, Applications, and Biodegradability Assessment

“…According to the literature, porous structures can be freely obtained directly through the 3D printing process [135,136]; however, the pores constructed in this way are usually macroscopic, which limits the overall porosity. It is possible to 3D print composites filled with removable particles/components and then remove them.…”

“…In the same test, the degradation of PLA prints yielded a surprisingly low result (21.7%); the extrusion and printing process may affect structural changes within this polymer [201]. PBAT, as a representative of polyesters containing an aromatic group, has a significantly reduced susceptibility to chemical hydrolysis compared with aliphatic esters [135].…”

Investigation of effect of processing parameters of 3D printed NHS/EDC crosslinked carboxy methyl cellulose/gelatin hydrogels with machine learning techniques

“…The 3D GEL-CMC scaffold's of square shape was designed using Solidworks computer-aided design (CAD) with standardized dimensions of 10 mm × 10 mm × 2 mm. Printing parameters included a speed of 4 mm s −1 , a needle type of 21 G, and The printing temperature of the samples were optimized by using a (Anton Paar, MCR302, Graz, Austria) rheometer [23]. The extrusion pressures were 20, 45, 82 and 38 psi and the printing temperatures were 36 °C, 50 °C, 75 °C and 50 °C for 7.5GEL-7.5CMC, 7.5GEL-10CMC, 7.5GEL-15CMC and 7.5GEL-10CMC-1GO for the prepared inks, respectively.…”