Development of a novel tubular scaffold for tissue-engineered small intestine

Infants with short bowel syndrome (SBS) have significant morbidity and mortality, especially if they depend on parenteral nutrition. Tissue-engineered small intestine (TESI) has been considered a potential therapeutic option for SBS but normal peristaltic function remains a challenge. The purpose of this study was to develop a novel tubular scaffold that promotes smooth muscle cell (SMC) alignment and ultimately peristalsis of TESI constructs.

Tubular scaffolds with aligned fibers were fabricated by electrospinning a 1:1 blend of polycaprolactone/type I collagen onto a mandrel rotating at 9,000-11,000 rpms. The fiber diameter, alignment, mechanical properties, and in vitro degradation rate were characterized. Primary human intestinal SMCs were seeded on aligned fiber tubular scaffolds and non-aligned scaffolds, cultured for 1 week, and analyzed with confocal and scanning electron microscopy to assess SMC alignment. Non-aligned scaffolds were fabricated with identical parameters of aligned fiber scaffolds except the mandrel speed was 1,000 rpms.

Scaffolds spun at 9-11,000 rpms (aligned) had circumferentially aligned fibers compared to those spun at 1,000 rpms (non-aligned). The aligned scaffolds demonstrated anisotropic mechanical properties with higher stiffness and strength when tensile tested in the direction of the fibers compared to perpendicular to the fibers. SMCs seeded on scaffolds demonstrated good alignment on aligned compared to non-aligned scaffolds which demonstrated more random orientation.

We developed electrospun tubular scaffolds with circumferentially aligned fibers that promote SMC alignment, have good mechanical strength and degradation profile suitable for the development of TESI. Future work will evaluate in vivo degradation and tissue formation of seeded constructs.