A 3D Bioprinted In Vitro Model of Pulmonary Artery Atresia to Evaluate Endothelial Cell Response to Microenvironment

Extrusion‐Based 3D Bioprinting of Adhesive Tissue Engineering Scaffolds Using Hybrid Functionalized Hydrogel Bioinks

“…First, we examined the printability of various bioinks using our well‐established macro (bulk)‐ and micro (strand)‐ level fidelity measurement protocols ( Figure 3 , Table 2 ). [ 31,32,67 ] The bulk fidelity measurements of ATES diameter ( d ) showed r d,bulk ratios 78 ± 1%, 92 ± 1%, 87 ± 1%, 88 ± 1%, and 93 ± 1% for HAMA, GelMA, HAMA/GelMA, HAMA‐Dopa/GelMA (embedded printed), and HAMA‐Dopa/GelMA (air printed) groups, respectively (Figure 3A,B, Table 2). Further, the perimeter of disc‐shape constructs was measured to calculate r P,bulk ratios of 81 ± 1%, 96 ± 1%, 91% ±1%, 95 ± 2%, and 102 ± 1% for HAMA, GelMA, HAMA/GelMA, HAMA‐Dopa/GelMA (embedded printed), and HAMA‐Dopa/GelMA (air printed) groups, respectively (Figure 3A,B, Table 2).…”

“…Fidelity of bioprinted ATES constructs was evaluated at two different scales as previously reported. [ 23,30–32 ] First, strand‐level (micro) fidelity was examined [ 31 ] by printing a 2D network of bioink strands on the glass slide based on a lattice pattern designed by CAD software (Figure 1C). The diameter of the strands ( d strand ), the angle between two crossing strands ( α strands ), and the area between two pairs of parallel strands ( A strands ) were measured (ImageJ) and normalized by dividing to the corresponding values in the CAD design ( d strand in CAD , α strands in CAD , and A strands in CAD ) using the following equations: $$$$\begin{eqnarray}{r}_{{\rm{d,strand}}} = \frac{{{d}_{{\rm{strand\ in\ print}}}}}{{{d}_{{\rm{strand\ in\ CAD}}}}}\ \times \ 100\end{eqnarray}$$$$ $$$$\begin{eqnarray}{r}_{{\rm{\alpha ,strand}}} = \frac{{{\alpha }_{{\rm{strands\ in\ print}}}}}{{{\alpha }_{{\rm{strands\ in\ CAD}}}}}\ \times \ 100\end{eqnarray}$$$$ $$$$\begin{eqnarray}{r}_{{\rm{A,strand}}} = \frac{{{A}_{{\rm{strands\ in\ print}}}}}{{{A}_{{\rm{strands\ in\ CAD}}}}}\ \times \ 100\end{eqnarray}$$$$…”

“…Fidelity of bioprinted ATES constructs was evaluated at two different scales as previously reported. [23,[30][31][32] First, strand-level (micro) fidelity was examined [31] by printing a 2D network of bioink strands on the glass slide based on a lattice pattern designed by CAD software (Figure 1C). The diameter of the strands (d strand ), the angle between two crossing strands (𝛼 strands ), and the area between two pairs of parallel strands (A strands ) were measured (Im-ageJ) and normalized by dividing to the corresponding values in the CAD design (d strand in CAD , 𝛼 strands in CAD , and A strands in CAD ) using the following equations:…”

Leveraging 3D Bioprinting and Photon‐Counting Computed Tomography to Enable Noninvasive Quantitative Tracking of Multifunctional Tissue Engineered Constructs

“…Preparation of GelMA Bioinks: The GelMA used in this study was synthesized using a similar protocol as in previous studies. [55,56,59] Briefly, PBS was used to dissolve gelatin powder at 10% (w/v) at 50 °C, with methacrylic anhydride (MA, Sigma) added dropwise at the same temperature over a 3-h period. To stop the methacrylate reaction, warm PBS was added to the solution, followed by dialysis in deionized (DI) water for 1 week at 40 °C.…”

“…Strand diameter ratio (r d ), strand angle ratio (r 𝛼 ), strand uniformity ratio (r U ), and inter-strand area ratio (r A ) was measured as representative of strand-level fidelity using the protocol established before. [19,55,59,108] In this method, r d determines the accuracy in the printed strand diameter, r 𝛼 measures the precision in the angle between the two layers of strands, r U quantifies the uniformity (straightness) of the extruded strands, and r A quantifies the surface area variation of the quadrilateral areas created by four crossing strands, and. These ratios were obtained by dividing the measured (experimental) values by the theoretical value for each parameter in the CAD design using the following equations:…”