Confocal imaging of HepG2 and SK-HEP-1 cells stained with CTred and CTgreen, both markers for live cells.

<p>Type-I collagen treated NFCA threads with HepG2 cells mixed within the material (red staining/HepG2 cells within the thread). A-B) HepG2 cells seeded on the surface of the NFCA threads and incubated for 72h (green). C-D) SK-HEP-1 cells seeded on the surface of the NFCA threads and incubated for 48h (green). HepG2 cells within the threads grew individually or in very small clusters; however, surface growth showed typical cluster and epithelial morphology of HepG2 and SK-HEP-1 respectively.</p

Viscosity measurements of NFC and NFCA samples.

<p>Addition of alginate increases the viscosity of the hydrogel composition. A minor increase can be observed with the incremental addition of alginate content within the mixture.</p

NFCA coated suture performance testing on small-animal tissues.

<p>Suturing was completed with instrument type knots. 12 out of 14 successful sutures were performed on mouse and rat skin (A and B) in addition to rat intestine (C). Some peeling off was observed in 2 sutures during the performance testing (D). Failed sutures were clearly visible and easily noticed as long tube-like segments (D).</p

Confocal imaging and preparation of NFCA-HepG2 coated surgical sutures.

<p>Live staining of CTred was performed after 72 h incubation. A) Sutures coated with NFCA-HepG2 and sewn three times through a pig liver segment indicating live HepG2 cells within the coating matrix. B, D) Preparation method of NFCA coated sutures. C) NFCA-HepG2 coating could be peeled off from the surgical suture as intact segments without damaging its tube-like structure showing live HepG2 cells remaining within the coating.</p

Live/Dead confocal imaging of NFCA-HepG2 threads stained with FDA (alive/green) and PI (dead/red).

<p>A) HepG2 cells were mixed within the NFCA before crosslinking; after 1-week of incubation and C) after 2 weeks of incubation. B) HepG2 cells were seeded on top of type-I collagen treated NFCA threads; after 1-week of incubation and D) after 2 weeks of incubation. An increase in the number of cells after the 2-week incubation period was not observed when the cells were mixed within the NFCA material. However, HepG2 clusters were growing on the surface cultures. Only a few dead cells were observed during the study period.</p