Functional Imaging for Regenerative Medicine: Tracking Vascularization of Intestinal Scaffolds

Area of Science:

• Biomedical Engineering
• Regenerative Medicine
• Medical Imaging

Background:

• Tissue-engineered small intestine (TESI) requires vascularization before intestinal implantation.
• Current methods lack noninvasive monitoring for construct vascular maturity.
• Assessing vascular maturity is crucial for successful TESI clinical translation.

Purpose of the Study:

• To evaluate photoacoustic imaging (PAI) as a noninvasive tool for monitoring vascular maturity in TESI scaffolds.
• To assess regional and temporal changes in vascularization within implanted scaffolds.
• To correlate PAI findings with histological assessments of vascularization.

Main Methods:

• Fabrication of tubular TESI scaffolds using electrospinning.
• Implantation of scaffolds in the omentum of Sprague-Dawley rats for 1 and 2 months.
• Noninvasive imaging of scaffolds using PAI to quantify tissue oxygenation and hemoglobin concentration.
• Correlation of PAI data with gross vascular observations and histological analysis.

Main Results:

• PAI successfully detected regional and temporal changes in scaffold vascularization.
• The top wall of the scaffold showed superior vascular maturity compared to the bottom wall.
• Vascular maturity in the top wall improved from 1 to 2 months post-implantation.
• PAI findings were consistent with gross and histological assessments.

Conclusions:

• PAI is a viable noninvasive method for monitoring vascular maturity in TESI constructs.
• This imaging technique can inform the timing of the second surgical procedure for TESI implantation.
• PAI has broad applicability for assessing vascularization in various tissue-engineered constructs.