3D Bioplotting of Gelatin/Alginate Scaffolds for Tissue Engineering: Influence of Crosslinking Degree and Pore Architecture on Physicochemical Properties

doi:10.1016/j.jmst.2016.01.007

Abstract

Abstract:

Gelatin/Alginate hydrogels were engineered for bioplotting in tissue engineering. One major drawback of hydrogel scaffolds is the lack of adequate mechanical properties. In this study, using a bioplotter, we constructed the scaffolds with different pore architectures by deposition of gelatin/alginate hydrogels layer-by-layer. The scaffolds with different crosslinking degree were obtained by post-crosslinking methods. Their physicochemical properties, as well as cell viability, were assessed. Different crosslinking methods had little influence on scaffold architecture, porosity, pore size and distribution. By contrast, the water absorption ability, degradation rate and mechanical properties of the scaffolds were dramatically affected by treatment with various concentrations of crosslinking agent (glutaraldehyde). The crosslinking process using glutaraldehyde markedly improved the stability and mechanical strength of the hydrogel scaffolds. Besides the post-processing methods, the pore architecture can also evidently affect the mechanical properties of the scaffolds. The crosslinked gelatin/alginate scaffolds showed a good potential to encapsulate cells or drugs.

Key words: Bioplotting, Tissue engineering, Scaffolds, Gelatin, Alginate

Pan Ting,Song Wenjing,Cao Xiaodong,Wang Yingjun. 3D Bioplotting of Gelatin/Alginate Scaffolds for Tissue Engineering: Influence of Crosslinking Degree and Pore Architecture on Physicochemical Properties[J]. J. Mater. Sci. Technol., 2016, 32(9): 889-900.

Figures/Tables 11

Fig. 1. FTIR spectra of gelatin/alginate scaffolds with different crosslinking processes.

Fig. 2. Fluorescent images of wet scaffolds treated with different crosslinking processes: (a) CaCl2; (b) CaCl2+0.25% GTA; (c) CaCl2+1% GTA; (d) CaCl2+2.5% GTA; (e) CaCl2+0.25% GTA -90°.

Fig. 3. Low vacuum ESEM images of wet scaffolds of different magnifications: (a) CaCl2; (b) CaCl2+0.25% GTA; (c) CaCl2+1% GTA; (d) CaCl2+2.5% GTA; (e) CaCl2+0.25% GTA -90°.

Fig. 4. 3D rotational microscopy images of magnified surface and cross section of the dried scaffold: (a) CaCl2; (b) CaCl2+0.25% GTA; (c) CaCl2+1% GTA; (d) CaCl2+2.5% GTA; (e) CaCl2+0.25% GTA-90°. 1, 2 indicate the horizontal sections with different magnifications and 3 represents the vertical cross-sections of scaffolds.

Fig. 5. SEM images of magnified surface and cross section of the dried scaffold: (a) CaCl2; (b) CaCl2+0.25% GTA; (c) CaCl2+1% GTA; (d) CaCl2+2.5% GTA; (e) CaCl2+0.25% GTA-90°. 1, 2 indicate the horizontal sections with different magnifications and 3 represents the vertical cross-sections of scaffolds.

Fig. 6. (a) Porosity of both wet and dried scaffolds treated with different crosslinking processes, (b-f) pore size distribution of dried scaffolds. * indicated that there was significant difference (p?<?0.05).

Fig. 7. Reconstruction of 3D images of dried scaffolds by micro-CT: (a) CaCl2; (b) CaCl2+0.25% GTA; (c) CaCl2+1% GTA; (d) CaCl2+2.5% GTA; (e) CaCl2+0.25% GTA-90°.

Fig. 8. Water absorption ability of dried scaffolds.

Fig. 9. Degradation rate of hydrogel scaffolds.

Fig. 10. (a) Stress-strain curves with a compressing rate of 1?mm/min, (b) and (c) comparison of final deformation rate and Young's modulus. * indicated that there was significant difference (p?<?0.05).

Fig. 11. Fluorescent images of mBMSCs cell adhesion on scaffolds cultured for 3 days. The three parallel figures indicate three different focal planes under the same visual field.

References

[1]	S. Bose, M. Roy, A. Bandyopadhyay.Trends Biotechnol, 30(2012), pp. 546-554
[2]	F.P. W.Melchels, M.A.N. Domingos, T.J. Klein, J. Malda, P.J. Bartolo, D.W. Hutmacher. Prog. Polym. Sci, 37(2012), pp. 1079-1104
[3]	T. Mygind, M. Stiehler, A. Baatrup, H. Li, X. Zoua, A. Flyvbjerg, M. Kassem, C. Bunger.Biomaterials, 28(2007), pp. 1036-1047
[4]	X. Mingen, L. Yanlei, S. Hairui, Y. Yongnian, L. Li, W. Qiujun, G. Yakun, X. Ying.Biofabrication, 2(2010) 025002
[5]	B. Derby.Science, 338(2012), pp. 921-926
[6]	S.V. Murphy, A. Atala. Nat.Biotechnol, 32(2014), pp. 773-785
[7]	A. Atala, J. Yoo. Manuf. Eng(2015), pp. 63-66
[8]	A. Skardal, A. Atala. Ann.Biomed. Eng, 43(2015), pp. 730-746
[9]	B.V. Slaughter, S.S. Khurshid, O.Z. Fisher, A. Khademhosseini, N.A. Peppas.Adv. Mater, 21(2009), pp. 3307-3329
[10]	T.T. Lau, J.R.E.Neo, D.A. Wang. Polym. Int, 63(2014), pp. 1600-1607
[11]	X. Hu, Y. Zhu, C. Gao. Prog.Chem, 21(2009), pp. 2164-2175
[12]	S.V. Murphy, A. Skardal, A. Atala. J.Biomed. Mater. Res. A, 101(2013), pp. 272-284
[13]	M. Xu, X. Wang, Y. Yan, R. Yao, Y. Ge.Biomaterials, 31(2010), pp. 3868-3877
[14]	J.Y. Park, J.C. Choi, J.H. Shim, J.S. Lee, H. Park, S.W. Kim, J. Doh, D.W. Cho.Biofabrication, 6(2014) 035004
[15]	T. Zhang, Y. Yan, X. Wang, Z. Xiong, F. Lin, R. Wu, R. Zhang. J.Bioact. Compat. Pol, 22(2007), pp. 19-29
[16]	N.E. Fedorovich, I. Swennen, J. Girones, L. Moroni, C.A. van Blitterswijk, E. Schacht, J. Alblas, W.J.A. Dhert. Biomacromolecules, 10(2009), pp. 1689-1696
[17]	F. Zhang, K. Su, Y. Fang, S. Sandhya, D.A. Wang. J. Tyear Eng.Regen. Med, 9(2015), pp. 77-84
[18]	W. Xu, X. Wang, Y. Yan, W. Zheng, Z. Xiong, F. Lin, R. Wu, R. Zhang. J.Bioact. Compat. Pol, 22(2007), pp. 363-377
[19]	W. Leong, T.T. Lau, D.A. Wang.Acta Biomater, 9(2013), pp. 6459-6467
[20]	X. Hu, D. Li, C. Gao. Biotech.J., 6(2011), pp. 1388-1396
[21]	T. Billiet, M. Vandenhaute, J. Schelfhout, S. Van Vlierberghe, P. Dubruel.Biomaterials, 33(2012), pp. 6020-6041
[22]	Y. Elsayed, C. Lekakou, P. Tomlins. Polym.Test, 40(2014), pp. 106-115
[23]	A. Bigi, G. Cojazzi, S. Panzavolta, K. Rubini, N. Roveri.Biomaterials, 22(2001), pp. 763-768
[24]	R. Landers, A. Pfister, U. Hubner, H. John, R. Schmelzeisen, R. Mulhaupt. J.Mater. Sci, 37(2002), pp. 3107-3116
[25]	C.N. Grover, J.H. Gwynne, N. Pugh, S. Hamaia, R.W. Farndale, S.M. Best, R.E. Cameron.Acta Biomater, 8(2012), pp. 3080-3090
[26]	Z.W. Ma, Z.W. Mao, C.Y. Gao.Colloids Surf. B. Biointerfaces, 60(2007), pp. 137-157
[27]	J.L. Xu, L.Z. Bao, A.H. Liu, X.F. Jin, J.M. Luo, Z.C. Zhong, Y.F. Zheng. J. Alloy.Compd, 645(2015), pp. 137-142
[28]	V. Karageorgiou, D. Kaplan.Biomaterials, 26(2005), pp. 5474-5491
[29]	L. Zeng, Y. Yao, D.A. Wang, X. Chen. Mat.Sci. Eng.C-Mater, 34(2014), pp. 168-175
[30]	H.J. Lee, S.H. Ahn, G.H. Kim.Chem. Mater, 24(2012), pp. 881-891
[31]	A. Bigi, G. Cojazzi, S. Panzavolta, N. Roveri, K. Rubini.Biomaterials, 23(2002), pp. 4827-4832
[32]	F. Ganji, S. Vasheghani-Farahani, E. Vasheghani-Farahani.Iran. Polym. J., 19(2010), pp. 375-398
[33]	H. Zhuang, Y. Han, A. Feng. Mat.Sci. Eng.C-Mater, 28(2008), pp. 1462-1466
[34]	S.J. Hollister.Nat. Mater, 4(2005), pp. 518-524
[35]	L. Moroni, J.R. de Wijn, C.A. van Blitterswijk. Biomaterials, 27(2006), pp. 974-985