3D Plastronics Culture Chambers and Benchtop MRI Setup Toward Tissue Engineering Applications

The rise of low-field benchtop MRI offers exciting opportunities for non-invasive, volumetric imaging of large biofabricated tissues in standard tissue engineering labs. Although low-field benchtop MRI scanners provide a cost-effective and accessible option, their performance is often restricted by low signal-to-noise ratio (SNR) and the use of generic, non-optimized hardware. This study introduces a novel, fully integrated benchtop MRI setup for in situ imaging of 3D bioprinted constructs. A custom perfusion culture chamber was designed and fabricated using 3D Plastronics, a method that allows for the direct integration of a bridged loop-gap resonator (BLGR) onto the chamber's surface. The performance of this integrated setup was quantitatively compared to a conventional setup using a commercial, all-purpose coil. The evaluation included measurements of the quality factor (Q), noise factor (F), SNR, and B₁ ⁺ field mapping. The practical application was demonstrated by high-resolution imaging of a 3D bioprinted hydrogel scaffold under perfusion. The 3D Plastronics setup demonstrated superior performance over the commercial coil setup, achieving a 60% increase in measured SNR, which was consistent with theoretical predictions. This improvement was attributed mainly to a higher filling factor due to the coil's proximity to the sample, enabled by the 3D Plastronics approach. B₁ ⁺ field maps also indicated higher mean field strength and improved homogeneity for the integrated coil due to its optimized design. High-resolution (234 $\mu$ m³) images of the bioprinted scaffold clearly displayed its internal macroporous structure, in 20 min. Integrating radio frequency (RF) coils directly onto a culture chamber with 3D Plastronics greatly enhances imaging performance in low-field MRI for tissue engineering. This method offers a scalable, customizable platform for nondestructive, long-term monitoring of 3D tissue constructs and opens new possibilities for in situ studies of tissue development.