Non-Invasive Three-Dimensional Cell Analysis in Bioinks by Raman Imaging.

Area of Science:

• Biomaterials Science
• Cell Biology
• Biofabrication

Background:

• 3D bioprinting enables the creation of functional tissue models using bioinks.
• Analyzing embedded cells within bioprinted constructs non-invasively remains a significant challenge.
• Existing methods often lack the capability for non-destructive, molecular-level evaluation of cells in 3D cultures.

Purpose of the Study:

• To implement and evaluate Raman imaging as a non-invasive technique for analyzing cells within 3D bioprinted constructs.
• To assess the capability of Raman imaging in differentiating cell types and evaluating cellular phenotypes in various bioprinting formats and biomaterials.
• To establish Raman imaging as a quality control tool for bioprinted objects.

Main Methods:

• Raman imaging was employed for molecular-sensitive investigations on bioprinted objects.
• Experiments included different culture formats (2D, 3D-cast, 3D-printed), cell types (endothelial cells, fibroblasts), and biomaterials (alginate, alginate/nanofibrillated cellulose, alginate/gelatin).
• Multivariate analysis of spectral signatures was used for single-cell analysis.

Main Results:

• Raman imaging enabled marker-independent identification and localization of subcellular components within the biomaterial.
• The technique successfully discriminated between endothelial cells and fibroblasts based on their spectral signatures.
• Cellular features influenced by the bioprinting process were identified, and cell localization was accurately determined.

Conclusions:

• Raman imaging is a valuable tool for in situ analysis of cells in 3D cultures.
• The method allows for the evaluation of cell type localization and molecular phenotype in bioprinted objects.
• Raman imaging serves as an effective quality control measure for 3D bioprinted constructs.