3D printing bioactive PLGA scaffolds using DMSO as a removable solvent

Abstract

Present bioprinting techniques lack the methodology to print with bioactive materials that retain their biological functionalities. This constraint is due to the fact that extrusion-based printing of synthetic polymers is commonly performed at very high temperatures in order to achieve desired mechanical properties and printing resolutions. Consequently, current methodology prevents printing scaffolds embedded with bioactive molecules, such as growth factors. With the wide use of mesenchymal stem cells (MSCs) in regenerative medicine research, the integration of growth factors into 3D printed scaffolds is critical because it can allow for inducible MSC differentiation. We have successfully incorporated growth factors into extrusion printed poly (lactic-co-glycolic acid) (PLGA) scaffolds by introducing dimethyl sulfoxide (DMSO) for low temperature printing. Mechanical testing results demonstrated significantly different compressive and tensile properties for PLGA scaffold printed with or without DMSO. In particular, the PLGA-DMSO scaffold displayed a highly stretchable feature compared to the regular PLGA scaffold. The cellular response of growth factor introduction was evaluated in vitro using human mesenchymal stem cells (hMSCs). By evaporating the DMSO after printing, we ensured that there was no cytotoxic effect on seeded hMSCs. The addition of lineage specific growth factors led to increased expression of corresponding genetic markers for chondrogenesis, osteogenesis, and adipogenesis. We concluded that the use of DMSO for 3D printed scaffold fabrication with bioactive items is a revolutionary methodology in advancing regenerative medicine. The incorporation of bioactive molecules opens pathways to more therapeutic uses for 3D printing in treating damaged or deteriorating native tissue.

Recent advances in biomaterials for 3D scaffolds: A review

“…An issue when using extrusion printing technology for scaffold production is the elevated temperature (above 100 °C) that prevents the incorporation of bioactive materials promoting the healing process. Guo et al proposed lowering the printing temperature of PLGA scaffold by utilizing dimethyl sulfoxide (DMSO) as a solvent that allows for the incorporation of proteins favourable for induction of hMSC differentiation [172]. After the solvent treatment, the material became tougher with improved flexibility and compressive strength similar to that of native cartilage while the activity of the growth factors was retained with the cold printing method used.…”

Biomaterial-based cell delivery strategies to promote liver regeneration

“…4 ). As fabrication technologies such as 3D bioprinting continue to develop [ 202 ], researchers can take advantage of these methods to tailor synthetic-based scaffolds for hepatocyte culture and transplantation.

Fig.

…”

Biomacromolecules for Tissue Engineering: Emerging Biomimetic Strategies

“…One recent example of low temperature extrusion utilized an ink composed of PLGA and proteins dissolved together in dimethyl sulfoxide (DMSO), producing scaffolds with fibronectin, TGF-β, insulin, and BMP-2 that retained their bioactivity after the evaporation of DMSO. 82 The suspension of other growth factors in DMSO and other organic solvents, however, may result in protein denaturation and loss of bioactivity. 81 Developing solvent-free, low-temperature printing methods will thus be of interest to avoid the loss of bioactivity for proteins and other biomolecules while continuing to capitalize on the high spatial definition afforded by 3DP techniques.…”