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A novel cell-printing method and its application to hepatogenic differentiation of human adipose stem cell-embedded mesh structures.

Ahn SH, Lee HJ, Lee JS, Yoon H, Chun W, Kim GH - Sci Rep (2015)

Bottom Line: In the shell of the nozzle, a cross-linking agent flowed continuously onto the surface of the dispensed bioink in the core nozzle, so that the bioink struts were rapidly gelled, and any remnant cross-linking solution during the process was rapidly absorbed into the working stage, resulting in high cell-viability in the bioink strut and stable formation of a three-dimensional mesh structure.To demonstrate the applicability of the technique, preosteoblasts and human adipose stem cells (hASCs) were used to obtain cell-laden structures with multi-layer porous mesh structures.The fabricated cell-laden mesh structures exhibited reasonable initial cell viabilities for preosteoblasts (93%) and hASCs (92%), and hepatogenic differentiation of hASC was successfully achieved.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomechatronic Engineering, College of Biotechnology and Bioengineering, Sungkyunkwan University (SKKU), Suwon, South Korea.

ABSTRACT
We report a cell-dispensing technique, using a core-shell nozzle and an absorbent dispensing stage to form cell-embedded struts. In the shell of the nozzle, a cross-linking agent flowed continuously onto the surface of the dispensed bioink in the core nozzle, so that the bioink struts were rapidly gelled, and any remnant cross-linking solution during the process was rapidly absorbed into the working stage, resulting in high cell-viability in the bioink strut and stable formation of a three-dimensional mesh structure. The cell-printing conditions were optimized by manipulating the process conditions to obtain high mechanical stability and high cell viability. The cell density was 1 × 10(7) mL(-1), which was achieved using a 3-wt% solution of alginate in phosphate-buffered saline, a mass fraction of 1.2 wt% of CaCl2 flowing in the shell nozzle with a fixed flow rate of 0.08 mL min(-1), and a translation velocity of the printing nozzle of 10 mm s(-1). To demonstrate the applicability of the technique, preosteoblasts and human adipose stem cells (hASCs) were used to obtain cell-laden structures with multi-layer porous mesh structures. The fabricated cell-laden mesh structures exhibited reasonable initial cell viabilities for preosteoblasts (93%) and hASCs (92%), and hepatogenic differentiation of hASC was successfully achieved.

No MeSH data available.


The CD-CS process with an absorbent dispensing stage and the resulting stable cell-laden mesh structure.(a) Optical and SEM images of the absorbent dispensing stage and the glass dispensing stage. The wetted red dye shows the water absorption properties of the stages. (b) A cell-laden mesh structure fabricated using the CD-CS process with an absorbent stage. (c) The storage modulus G′ and complex viscosity n* of the cell-laden alginate cross-linked on the absorbent dispensing stage. (d) A comparison of the storage moduli at 0.1 Hz.
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f3: The CD-CS process with an absorbent dispensing stage and the resulting stable cell-laden mesh structure.(a) Optical and SEM images of the absorbent dispensing stage and the glass dispensing stage. The wetted red dye shows the water absorption properties of the stages. (b) A cell-laden mesh structure fabricated using the CD-CS process with an absorbent stage. (c) The storage modulus G′ and complex viscosity n* of the cell-laden alginate cross-linked on the absorbent dispensing stage. (d) A comparison of the storage moduli at 0.1 Hz.

Mentions: To overcome this problem, we designed a modified CD-CS system with a new dispensing stage, which was highly water-absorbing. This absorbent dispensing stage was formed of the thermosetting polymer melamine resin, and the surface was highly porous, as shown in Fig. 3(a). On this absorbent stage, we dispensed the cell-laden alginate solution in the core region and the cross-linking agent in the shell region. Figure 3(b) shows the cell-dispensing process with the absorbent dispensing stage and optical images showing the fabricated mesh structure. As shown in the optical images, a highly porous cell-laden structure was well obtained due to the rapid absorption of the cross-linking agent onto the dispensing stage. To evaluate the effects of the absorbent stage on the modulus of the dispensed struts, we measured the modulus of the cell-laden solution with two cross-linking times (i.e., 1 min and 5 min). Figure 3(c) shows the rheological properties with 3- and 5-wt% cell-laden alginate suspensions for the two cross-linking times, and with a 1.2-wt% CaCl2 solution. As with the previous results, the storage modulus of the cell-laden alginate with the longer cross-linking time was larger; however, the difference in the moduli between the two cross-linking times was significantly smaller than that obtained using the glass dispensing stage, as shown in Fig. 3(d). This result shows that the cross-linking agent was rapidly absorbed into the dispensing stage, resulting in increased adhesion between the struts due to the viscosity of the partially cross-linked alginate.


A novel cell-printing method and its application to hepatogenic differentiation of human adipose stem cell-embedded mesh structures.

Ahn SH, Lee HJ, Lee JS, Yoon H, Chun W, Kim GH - Sci Rep (2015)

The CD-CS process with an absorbent dispensing stage and the resulting stable cell-laden mesh structure.(a) Optical and SEM images of the absorbent dispensing stage and the glass dispensing stage. The wetted red dye shows the water absorption properties of the stages. (b) A cell-laden mesh structure fabricated using the CD-CS process with an absorbent stage. (c) The storage modulus G′ and complex viscosity n* of the cell-laden alginate cross-linked on the absorbent dispensing stage. (d) A comparison of the storage moduli at 0.1 Hz.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4544022&req=5

f3: The CD-CS process with an absorbent dispensing stage and the resulting stable cell-laden mesh structure.(a) Optical and SEM images of the absorbent dispensing stage and the glass dispensing stage. The wetted red dye shows the water absorption properties of the stages. (b) A cell-laden mesh structure fabricated using the CD-CS process with an absorbent stage. (c) The storage modulus G′ and complex viscosity n* of the cell-laden alginate cross-linked on the absorbent dispensing stage. (d) A comparison of the storage moduli at 0.1 Hz.
Mentions: To overcome this problem, we designed a modified CD-CS system with a new dispensing stage, which was highly water-absorbing. This absorbent dispensing stage was formed of the thermosetting polymer melamine resin, and the surface was highly porous, as shown in Fig. 3(a). On this absorbent stage, we dispensed the cell-laden alginate solution in the core region and the cross-linking agent in the shell region. Figure 3(b) shows the cell-dispensing process with the absorbent dispensing stage and optical images showing the fabricated mesh structure. As shown in the optical images, a highly porous cell-laden structure was well obtained due to the rapid absorption of the cross-linking agent onto the dispensing stage. To evaluate the effects of the absorbent stage on the modulus of the dispensed struts, we measured the modulus of the cell-laden solution with two cross-linking times (i.e., 1 min and 5 min). Figure 3(c) shows the rheological properties with 3- and 5-wt% cell-laden alginate suspensions for the two cross-linking times, and with a 1.2-wt% CaCl2 solution. As with the previous results, the storage modulus of the cell-laden alginate with the longer cross-linking time was larger; however, the difference in the moduli between the two cross-linking times was significantly smaller than that obtained using the glass dispensing stage, as shown in Fig. 3(d). This result shows that the cross-linking agent was rapidly absorbed into the dispensing stage, resulting in increased adhesion between the struts due to the viscosity of the partially cross-linked alginate.

Bottom Line: In the shell of the nozzle, a cross-linking agent flowed continuously onto the surface of the dispensed bioink in the core nozzle, so that the bioink struts were rapidly gelled, and any remnant cross-linking solution during the process was rapidly absorbed into the working stage, resulting in high cell-viability in the bioink strut and stable formation of a three-dimensional mesh structure.To demonstrate the applicability of the technique, preosteoblasts and human adipose stem cells (hASCs) were used to obtain cell-laden structures with multi-layer porous mesh structures.The fabricated cell-laden mesh structures exhibited reasonable initial cell viabilities for preosteoblasts (93%) and hASCs (92%), and hepatogenic differentiation of hASC was successfully achieved.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomechatronic Engineering, College of Biotechnology and Bioengineering, Sungkyunkwan University (SKKU), Suwon, South Korea.

ABSTRACT
We report a cell-dispensing technique, using a core-shell nozzle and an absorbent dispensing stage to form cell-embedded struts. In the shell of the nozzle, a cross-linking agent flowed continuously onto the surface of the dispensed bioink in the core nozzle, so that the bioink struts were rapidly gelled, and any remnant cross-linking solution during the process was rapidly absorbed into the working stage, resulting in high cell-viability in the bioink strut and stable formation of a three-dimensional mesh structure. The cell-printing conditions were optimized by manipulating the process conditions to obtain high mechanical stability and high cell viability. The cell density was 1 × 10(7) mL(-1), which was achieved using a 3-wt% solution of alginate in phosphate-buffered saline, a mass fraction of 1.2 wt% of CaCl2 flowing in the shell nozzle with a fixed flow rate of 0.08 mL min(-1), and a translation velocity of the printing nozzle of 10 mm s(-1). To demonstrate the applicability of the technique, preosteoblasts and human adipose stem cells (hASCs) were used to obtain cell-laden structures with multi-layer porous mesh structures. The fabricated cell-laden mesh structures exhibited reasonable initial cell viabilities for preosteoblasts (93%) and hASCs (92%), and hepatogenic differentiation of hASC was successfully achieved.

No MeSH data available.