Thiol-ene cross-linked alginate hydrogel encapsulation modulates the extracellular matrix of kidney organoids by reducing abnormal type 1a1 collagen deposition

• Published in: Biomaterials 2021-08, Vol.275, p.120976-120976, Article 120976
• Main Authors: Geuens, Thomas, Ruiter, Floor A.A., Schumacher, Anika, Morgan, Francis L.C., Rademakers, Timo, Wiersma, Loes E., van den Berg, Cathelijne W., Rabelink, Ton J., Baker, Matthew B., LaPointe, Vanessa L.S.
• Format: Article
• Language: English
• Subjects: Alginates; Biopolymers; Collagen Type I - metabolism; Collagen Type I, alpha 1 Chain; Extracellular Matrix; Humans; Hydrogel encapsulation; Hydrogels; Kidney; Kidney organoids; Organoids; Proteomics; Regenerative medicine; Sulfhydryl Compounds
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/j.biomaterials.2021.120976

Differentiated kidney organoids from induced pluripotent stem cells hold promise as a treatment for patients with kidney diseases. Before these organoids can be translated to the clinic, shortcomings regarding their cellular and extracellular compositions, and their developmental plateau need to be overcome. We performed a proteomic analysis on kidney organoids cultured for a prolonged culture time and we found a specific change in the extracellular matrix composition with increased expression of types 1a1, 2 and 6a1 collagen. Such an excessive accumulation of specific collagen types is a hallmark of renal fibrosis that causes a life-threatening pathological condition by compromising key functions of the human kidney. Here we hypothesized the need for a three-dimensional environment to grow the kidney organoids, which could better mimic the in vivo surroundings of the developing kidney than standard culture on an air–liquid interface. Encapsulating organoids for four days in a soft, thiol-ene cross-linked alginate hydrogel resulted in decreased type 1a1 collagen expression. Furthermore, the encapsulation did not result in any changes of organoid structural morphology. Using a biomaterial to modulate collagen expression allows for a prolonged kidney organoid culture in vitro and a reduction of abnormal type 1a1 collagen expression bringing kidney organoids closer to clinical application. •Prolonging kidney organoid culture results in a developmental plateau instead of improved in vitro maturation.•Proteomic analyses point to an increased expression of specific collagen subtypes associated with renal fibrosis.•Encapsulation using a soft thiol-ene cross-linked alginate hydrogel reduces collagen type 1a1 and αSMA deposition.