AUTHOR=Jeršovaitė Jurga , Šarachovaitė Ugnė , Matulaitienė Ieva , Niaura Gediminas , Baltriukienė Daiva , Malinauskas Mangirdas 

TITLE=Biocompatibility enhancement via post-processing of microporous scaffolds made by optical 3D printer

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2023.1167753

DOI=10.3389/fbioe.2023.1167753

ISSN=2296-4185

ABSTRACT=Providing a 3D environment that mimics the native extracellular matrix is becoming increasingly
important for various applications such as cell function studies, regenerative medicine, and
drug discovery. Among the most important parameters to be considered is the complicated
micro-scale geometry and material properties of the scaffold. Therefore, stereolithography based
on photopolymerization is highly promising in this field due to its ability to selectively form
volumetric structures from liquid resin through polymerization reactions. However, among the
vitally essential parameters of scaffold is biocompatibility, which depends mainly on the material,
but also exposure conditions and even post-processing. To systematically study this, microporous
scaffolds with pore sizes of 0.051727 mm3 corresponding to the porosity of 16,4 % were made
with Asiga PICO2 39 UV stereolithography printer of widespread FormLabs Clear and Flex resins.
Using them directly for tissue engineering is of limited suitability for cells since after wet chemicalk
development the non-negligible amount remaining monomers intertwinned in photopolymerized
structures remain significantly toxic to cells. So the aim of this research was to find the best
method for the elimination of monomers out of the 3D scaffold using additional UV exposure,
for the first time for this purpose applying a Soxhlet extractor and soaking them into different
alcohols. Also, through the use of Raman micro-spectroscopy, it was investigated if different
post-processing methods affect the degree of conversion (cross-linking) to learn if specifically
it affects the biocompatibility of scaffolds. Finally, rat dental pulp-derived mesenchymal stem
cells were studied to confirm the increase of biocompatibility on the scaffolds and their ability to
support cell differentiation into bone tissue cells.