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Bioprinting three-dimensional cell-laden tissue constructs with controllable degradation.

Wu Z, Su X, Xu Y, Kong B, Sun W, Mi S - Sci Rep (2016)

Bottom Line: However, the printed cells in this hydrogel could not degrade the surrounding alginate gel matrix, causing them to remain in a poorly proliferating and non-differentiating state.The 3D-printed hydrogel network with interconnected channels and a macroporous structure was stable and achieved high cell viability (over 90%).Cell proliferation and specific marker protein expression results also revealed that with the help of sodium citrate degradation, the printed HCECs showed a higher proliferation rate and greater cytokeratin 3(CK3) expression, indicating that this newly developed method may help to improve the alginate bioink system for the application of 3D bioprinting in tissue engineering.

View Article: PubMed Central - PubMed

Affiliation: Biomanufacturing Engineering Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P.R. China.

ABSTRACT
Alginate hydrogel is a popular biologically inert material that is widely used in 3D bioprinting, especially in extrusion-based printing. However, the printed cells in this hydrogel could not degrade the surrounding alginate gel matrix, causing them to remain in a poorly proliferating and non-differentiating state. Here, we report a novel study of the 3D printing of human corneal epithelial cells (HCECs)/collagen/gelatin/alginate hydrogel incubated with a medium containing sodium citrate to obtain degradation-controllable cell-laden tissue constructs. The 3D-printed hydrogel network with interconnected channels and a macroporous structure was stable and achieved high cell viability (over 90%). By altering the mole ratio of sodium citrate/sodium alginate, the degradation time of the bioprinting constructs can be controlled. Cell proliferation and specific marker protein expression results also revealed that with the help of sodium citrate degradation, the printed HCECs showed a higher proliferation rate and greater cytokeratin 3(CK3) expression, indicating that this newly developed method may help to improve the alginate bioink system for the application of 3D bioprinting in tissue engineering.

No MeSH data available.


Related in: MedlinePlus

Images of the degradation process of the scaffolds set in the sodium citrate solution, from (a) 0 min, (b) 10 min, (c) 20 min, (d) 30 min, (e) 40 min, (f) 50 min, when the C/A is 1000% (mol/mol, %). (g) The relation of the total degradation time of the scaffolds to the mole ratio of C/A. (h) The relation curve between the degradation time of the printed constructs and amount of sodium citrate added to the culture medium.
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f5: Images of the degradation process of the scaffolds set in the sodium citrate solution, from (a) 0 min, (b) 10 min, (c) 20 min, (d) 30 min, (e) 40 min, (f) 50 min, when the C/A is 1000% (mol/mol, %). (g) The relation of the total degradation time of the scaffolds to the mole ratio of C/A. (h) The relation curve between the degradation time of the printed constructs and amount of sodium citrate added to the culture medium.

Mentions: Because of the drawback that cells cannot degrade the surrounding alginate gel matrix, sodium citrate was used to accelerate the degradation of alginate hydrogels. Fig. 5(a–f) shows the degradation process of the scaffolds after incubating with PBS containing sodium citrate from 0 min to 50 min. In addition, by changing the mole ratio of the C/A, the degradation time of alginate hydrogels can be controlled. As Fig. 5g shows, if the C/A (mol/mol) is higher than 1, the alginate hydrogel would completely degrade in less than 3 days. If the C/A is less than 0.5, the total degradation time would be more than 2 weeks, and the degradation time dramatically increases as the C/A decreases by even a small amount. This finding indicates that, by using this method, 3D bioprinting of degradation-controllable cell-laden tissue constructs can be successfully fabricated. Additionally, by applying the least squares method to the quadratic fitting according to Fig. 5g, the relation curve between the degradation time and mole ratio of the C/A was obtained, which is y = 11.339x2 − 36.994x + 28.857, R2 = 0.9957 (y is the degradation time, x is the mole ratio of the C/A), as shown in Fig. 5h. This formula is applicable when the amount of sodium citrate is similar to or less than the amount of sodium alginate in the system. Otherwise, the constructs would degrade too quickly to be controllable; for example, they degrade completely after 1 hour when the C/A is 1000%, as shown in Fig. 5(a–f).


Bioprinting three-dimensional cell-laden tissue constructs with controllable degradation.

Wu Z, Su X, Xu Y, Kong B, Sun W, Mi S - Sci Rep (2016)

Images of the degradation process of the scaffolds set in the sodium citrate solution, from (a) 0 min, (b) 10 min, (c) 20 min, (d) 30 min, (e) 40 min, (f) 50 min, when the C/A is 1000% (mol/mol, %). (g) The relation of the total degradation time of the scaffolds to the mole ratio of C/A. (h) The relation curve between the degradation time of the printed constructs and amount of sodium citrate added to the culture medium.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835808&req=5

f5: Images of the degradation process of the scaffolds set in the sodium citrate solution, from (a) 0 min, (b) 10 min, (c) 20 min, (d) 30 min, (e) 40 min, (f) 50 min, when the C/A is 1000% (mol/mol, %). (g) The relation of the total degradation time of the scaffolds to the mole ratio of C/A. (h) The relation curve between the degradation time of the printed constructs and amount of sodium citrate added to the culture medium.
Mentions: Because of the drawback that cells cannot degrade the surrounding alginate gel matrix, sodium citrate was used to accelerate the degradation of alginate hydrogels. Fig. 5(a–f) shows the degradation process of the scaffolds after incubating with PBS containing sodium citrate from 0 min to 50 min. In addition, by changing the mole ratio of the C/A, the degradation time of alginate hydrogels can be controlled. As Fig. 5g shows, if the C/A (mol/mol) is higher than 1, the alginate hydrogel would completely degrade in less than 3 days. If the C/A is less than 0.5, the total degradation time would be more than 2 weeks, and the degradation time dramatically increases as the C/A decreases by even a small amount. This finding indicates that, by using this method, 3D bioprinting of degradation-controllable cell-laden tissue constructs can be successfully fabricated. Additionally, by applying the least squares method to the quadratic fitting according to Fig. 5g, the relation curve between the degradation time and mole ratio of the C/A was obtained, which is y = 11.339x2 − 36.994x + 28.857, R2 = 0.9957 (y is the degradation time, x is the mole ratio of the C/A), as shown in Fig. 5h. This formula is applicable when the amount of sodium citrate is similar to or less than the amount of sodium alginate in the system. Otherwise, the constructs would degrade too quickly to be controllable; for example, they degrade completely after 1 hour when the C/A is 1000%, as shown in Fig. 5(a–f).

Bottom Line: However, the printed cells in this hydrogel could not degrade the surrounding alginate gel matrix, causing them to remain in a poorly proliferating and non-differentiating state.The 3D-printed hydrogel network with interconnected channels and a macroporous structure was stable and achieved high cell viability (over 90%).Cell proliferation and specific marker protein expression results also revealed that with the help of sodium citrate degradation, the printed HCECs showed a higher proliferation rate and greater cytokeratin 3(CK3) expression, indicating that this newly developed method may help to improve the alginate bioink system for the application of 3D bioprinting in tissue engineering.

View Article: PubMed Central - PubMed

Affiliation: Biomanufacturing Engineering Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen, P.R. China.

ABSTRACT
Alginate hydrogel is a popular biologically inert material that is widely used in 3D bioprinting, especially in extrusion-based printing. However, the printed cells in this hydrogel could not degrade the surrounding alginate gel matrix, causing them to remain in a poorly proliferating and non-differentiating state. Here, we report a novel study of the 3D printing of human corneal epithelial cells (HCECs)/collagen/gelatin/alginate hydrogel incubated with a medium containing sodium citrate to obtain degradation-controllable cell-laden tissue constructs. The 3D-printed hydrogel network with interconnected channels and a macroporous structure was stable and achieved high cell viability (over 90%). By altering the mole ratio of sodium citrate/sodium alginate, the degradation time of the bioprinting constructs can be controlled. Cell proliferation and specific marker protein expression results also revealed that with the help of sodium citrate degradation, the printed HCECs showed a higher proliferation rate and greater cytokeratin 3(CK3) expression, indicating that this newly developed method may help to improve the alginate bioink system for the application of 3D bioprinting in tissue engineering.

No MeSH data available.


Related in: MedlinePlus