Low-cost, rapidly-developed, 3D printed in vitro corpus callosum model for mucopolysaccharidosis type I

Abstract

The rising prevalence of high throughput screening and the general inability of (1) two dimensional (2D) cell culture and (2) release studies to predict in vitro in neurobiological and pharmacokinetic responses in humans has led to vivo greater interest in more realistic three dimensional (3D) benchtop platforms. Advantages of 3D human cell culture over its 2D analogue, or even animal models, include taking the effects of microgeometry and long-range topological features into consideration. In the era of personalized medicine, it has become increasingly valuable to screen candidate molecules and synergistic therapeutics at a patient-specific level, in particular for diseases that manifest in highly variable ways. The lack of established standards and the relatively arbitrary choice of probing conditions has limited drug release to a in vitro largely qualitative assessment as opposed to a predictive, quantitative measure of pharmacokinetics and pharmacodynamics in tissue. Here we report the methods used in the rapid, low-cost development of a 3D model of a mucopolysaccharidosis type I patient's corpus callosum, which may be used for cell culture and drug release. The CAD model is developed from brain in vivo MRI tracing of the corpus callosum using open-source software, printed with poly (lactic-acid) on a Makerbot Replicator 5X, UV-sterilized, and coated with poly (lysine) for cellular adhesion. Adaptations of material and 3D printer for expanded applications are also discussed.

Quantitative criteria to benchmark new and existing bio-inks for cell compatibility

“…Recent development of new bio-inks has focused primarily on the printability of the material and the cell compatibility post-printing, often overlooking the viability of the cells during printing. These studies have enabled proof-of-concept demonstrations for many different applications in tissue engineering and regenerative medicine[3–8], tissue modeling [6, 7, 9, 10], and stem cell biology [11]. As the field expands beyond proof-of-concept studies, it will be increasingly important to also consider the bio-ink compatibility with the cells during the fabrication process to make 3D bioprinting scalable and cost efficient.…”

Low-cost, rapidly-developed, 3D printed in vitro corpus callosum model for mucopolysaccharidosis type I

“…The 3D model was printed on a Makerbot Replicator 5X, sterilized ( Figure 1 ), and could be used for cell culture or in vitro release studies. The de-identified MRI scans were obtained as Digital Imaging and Communications in Medicine (DICOM) files ( Dataset 1 11 ). The CC was traced on the mid-sagittal slice and five adjacent slices in each hemisphere using open source InVesalius 3 ( http://www.cti.gov.br/invesalius/ , RRID: SCR_014693).…”

“…MRICron 1.0 ( http://people.cas.sc.edu/rorden/mricron/index.html ) RRID:SCR_002403 or mri_convert 1.0 ( https://surfer.nmr.mgh.harvard.edu/fswiki/mri_convert ) software packages may be used to convert between DICOM and NIfTI-1. The software was then used to render the scans into a single .STL file ( Dataset 2 12 ). The 3D model of the CC was loaded into MakerBot Desktop v. 3.6.0.78 ( https://www.makerbot.com/download-desktop/ ) and printed on a MakerBot Replicator 5X with poly(lactic acid) at a resolution of 0.2 mm, maintaining life-size dimensions.…”

“…Dataset 1 : DICOM files for the de-identified MRI scans of the corpus callosum of a MPS I subject, doi: 10.5256/f1000research.9861.d144327 11 …”

“…Dataset 2 : Resulting CAD file from InVesalius 3 software (.STL), used to render the DICOM files in Dataset 1 , doi: 10.5256/f1000research.9861.d144328 12 …”