Abstract
Background:
Kidney tubular engineering requires structures of small sizes (≤1mm) to mimic curvature of native kidney proximal tubule (PT), which is key for cellular functionality and maturation. Here, we created highly porous rhombus tubules using melt-electrowriting (MEW) to build a vascularized PT.
Methods:
A MEW device was used to print small polycaprolactone tubular scaffolds (inner ø: 1 mm) with defined rhombus microarchitectures (winding angles of 30°, 50° and 70°). Human conditionally immortalized PT epithelial cells (ciPTEC) and glomerular endothelial cells (ciGEnC) were seeded alone or consecutively in the scaffolds and evaluated via immunofluorescent stainings for monolayer formation and tightness (zonula occludens-1, cluster of differentiation 31 (CD31)), cell directionality (F-actin), polarization (a-tubulin, Na+K+-ATPase) and extracellular matrix (ECM) production (collagen IV). Furthermore, gene expression of endothelial (CD31 and Von Willebrand Factor) and PT (organic cation transporter-2, P-glycoprotein (P-gp), multidrug resistance protein) markers was measured via RT-qPCR, and P-gp transport was studied in the tubular scaffolds.
Results:
Tubular scaffolds (length: 2 cm, inner ø: 1 mm) with different rhombus microarchitectures were manufactured by controlling key instrument parameters. Both ciPTEC and ciGEnC formed tight monolayers within the tubular scaffolds and generated collagen IV-enriched ECM. The 30° winding angles induced preferential cell alignment along the scaffold fiber direction for ciPTEC and ciGEnC, and facilitated formation of polarized monolayers. Consecutive seeding of first ciPTEC and, after monolayer formation, ciGEnC enabled growth of endothelial cells on the ECM deposited by ciPTEC, thereby forming a vascularized PT, maintaining high gene expression of PT markers, and showing increased functionality of P-gp in co-culture.
Conclusion:
MEW tubes with highly controlled microarchitectures advance ciPTEC and ciGEnC organization and ECM deposition. Our results show the first prototype of a vascularized scaffold, where the basement membrane formed by ciPTEC supports ciGEnC adhesion and growth. This innovative approach not only shows the potential of MEW in tissue engineering but also sets a new benchmark for the creation of functional, bioengineered kidney models.
Kidney tubular engineering requires structures of small sizes (≤1mm) to mimic curvature of native kidney proximal tubule (PT), which is key for cellular functionality and maturation. Here, we created highly porous rhombus tubules using melt-electrowriting (MEW) to build a vascularized PT.
Methods:
A MEW device was used to print small polycaprolactone tubular scaffolds (inner ø: 1 mm) with defined rhombus microarchitectures (winding angles of 30°, 50° and 70°). Human conditionally immortalized PT epithelial cells (ciPTEC) and glomerular endothelial cells (ciGEnC) were seeded alone or consecutively in the scaffolds and evaluated via immunofluorescent stainings for monolayer formation and tightness (zonula occludens-1, cluster of differentiation 31 (CD31)), cell directionality (F-actin), polarization (a-tubulin, Na+K+-ATPase) and extracellular matrix (ECM) production (collagen IV). Furthermore, gene expression of endothelial (CD31 and Von Willebrand Factor) and PT (organic cation transporter-2, P-glycoprotein (P-gp), multidrug resistance protein) markers was measured via RT-qPCR, and P-gp transport was studied in the tubular scaffolds.
Results:
Tubular scaffolds (length: 2 cm, inner ø: 1 mm) with different rhombus microarchitectures were manufactured by controlling key instrument parameters. Both ciPTEC and ciGEnC formed tight monolayers within the tubular scaffolds and generated collagen IV-enriched ECM. The 30° winding angles induced preferential cell alignment along the scaffold fiber direction for ciPTEC and ciGEnC, and facilitated formation of polarized monolayers. Consecutive seeding of first ciPTEC and, after monolayer formation, ciGEnC enabled growth of endothelial cells on the ECM deposited by ciPTEC, thereby forming a vascularized PT, maintaining high gene expression of PT markers, and showing increased functionality of P-gp in co-culture.
Conclusion:
MEW tubes with highly controlled microarchitectures advance ciPTEC and ciGEnC organization and ECM deposition. Our results show the first prototype of a vascularized scaffold, where the basement membrane formed by ciPTEC supports ciGEnC adhesion and growth. This innovative approach not only shows the potential of MEW in tissue engineering but also sets a new benchmark for the creation of functional, bioengineered kidney models.
| Original language | English |
|---|---|
| Pages (from-to) | E905-E906 |
| Number of pages | 2 |
| Journal | Tissue Engineering - Part A |
| Volume | 31 |
| Issue number | 11-12 |
| DOIs | |
| Publication status | Published - 1 Jun 2025 |