The biological scaffolds of tissue engineering are required to have good biocompatibility, matched mechanical properties, as well as morphology and microstructure for cell growth and reproduction. Although a large number of biomaterials have been developed to prepare tissue-engineering scaffolds, the forming problems and poor mechanical properties of the scaffolds still seriously limit the development of tissue engineering. The sodium alginate was used as raw material, and its mechanical properties were enhanced by agarose. The structure and morphology of sodium alginate/agarose composite hydrogels with different ratios were studied, the mechanical properties were tested. In addition, the composite hydrogel scaffold was formed by direct ink writing, and the size of the microscopic pores in composite hydrogels were designed and observed. The results show that the composite hydrogels with different ratios have little difference in water content, all around 90%. Apart from the pure agarose gel and the composite gel with a volume ratio of 1:2, the surface and cross section of the composite gel in other ratios are relatively rough. Agarose can enhance the composite gel to a certain extent, and the composite gel with the volume ratio of sodium alginate to agarose of 2:1 has the highest compression modulus, which can reach 0.353 MPa. The decomposition of calcium carbonate created submicron pores in the composite hydrogel, therefore the prepared composite hydrogel has rough surface and micro-pores, which is conducive for cell growth and reproduction.
RUDGE C , MATESANZ R , DELMONICO F L , et al. International practices of organ donation[J]. British Journal of Anaesthesia, 2012, 108 (Suppl 1): 48- 55.
2
KHOJASTEH A , BEHNIA H , DASHTI S G , et al. Current trends in mesenchymal stem cell application in bone augmentation: a review of the literature[J]. Journal of Oral and Maxillofacial Surgery, 2012, 70 (4): 972- 982.
doi: 10.1016/j.joms.2011.02.133
3
KHOJASTEH A , BEHNIA H , NAGHDI N , et al. Effects of different growth factors and carriers on bone regeneration: a systematic review[J]. Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 2013, 116 (6): 405- 423.
doi: 10.1016/j.oooo.2012.01.044
4
SHAYESTEH Y S , KHOJASTEH A , SOLEIMANI M , et al. Sinus augmentation using human mesenchymal stem cells loaded into a beta-tricalcium phosphate/hydroxyapatite scaffold[J]. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology, 2008, 106 (2): 203- 209.
doi: 10.1016/j.tripleo.2007.12.001
5
SHIEH S J , VACANTI J P . State-of-the-art tissue engineering: from tissue engineering to organ building[J]. Surgery, 2005, 137 (1): 1- 7.
doi: 10.1016/j.surg.2004.04.002
6
GRIFFITH L G , NAUGHTON G . Tissue engineering-current challenges and expanding opportunities[J]. Science, 2002, 295 (5557): 1009- 1014.
doi: 10.1126/science.1069210
7
KHADEMHOSSEINI A , LANGER R . A decade of progress in tissue engineering[J]. Nature Protocols, 2016, 11 (10): 1775- 1781.
doi: 10.1038/nprot.2016.123
8
LEE K Y , MOONEY D J . Alginate: properties and biomedical applications[J]. Progress in Polymer Science, 2012, 37 (1): 106- 126.
doi: 10.1016/j.progpolymsci.2011.06.003
9
SLAUGHTER B V , KHURSHID S S , FISHER O Z , et al. Hydrogels in regenerative medicine[J]. Advanced Materials, 2009, 21 (32/33): 3307- 3329.
10
ZHAO X , LANG Q , YILDIRIMER L , et al. Photocrosslinkable gelatin hydrogel for epidermal tissue engineering[J]. Advanced Healthcare Materials, 2016, 5 (1): 108- 118.
doi: 10.1002/adhm.201500005
11
NGUYEN D , HAGG D A , FORSMAN A , et al. Cartilage tissue engineering by the 3D bioprinting of iPS cells in a nanocellulose/alginate bioink[J]. Scientific Reports, 2017, 7 (1): 658.
doi: 10.1038/s41598-017-00690-y
12
YANG X , LU Z , WU H , et al. Collagen-alginate as bioink for three-dimensional(3D) cell printing based cartilage tissue engineering[J]. Materials Science and Engineering: C, 2018, 83, 195- 201.
doi: 10.1016/j.msec.2017.09.002
13
LÓPEZ-MARCIAL G R , ZENG A Y , OSUNA C , et al. Agarose-based hydrogels as suitable bioprinting materials for tissue engineering[J]. ACS Biomaterials Science & Engineering, 2018, 4 (10): 610- 3616.
ZHANG X L , WANG L L , WENG L , et al. Preparation technology and application status of alginate medical material[J]. Cotton Textile Technology, 2019, 47 (4): 75- 80.
doi: 10.3969/j.issn.1001-7415.2019.04.020
15
JOHNSON F A , CRAIG D Q M , MERCER A D . Characterization of the block structure and molecular weight of sodium alginates[J]. Journal of Pharmacy and Pharmacology, 1997, 49 (7): 639- 643.
16
VENKATESAN J , BHATNAGAR I , MANIVASAGAN P , et al. Alginate composites for bone tissue engineering: a review[J]. International Journal of Biological Macromolecules, 2015, 72, 269- 281.
doi: 10.1016/j.ijbiomac.2014.07.008
17
WENDT D , JAKOB M , MARTIN I . Bioreactor-based enginee-ring of osteochondral grafts: from model systems to tissue manufacturing[J]. Journal of Bioscience and Bioengineering, 2005, 100 (5): 489- 494.
doi: 10.1263/jbb.100.489
REN L L , FENG X , MA D Y , et al. Mechanical properties of al-ginate hydrogels with different concentrations and their effects on the proliferation chondrocytes in vitro[J]. Journal of Biomedical Engineering, 2012, 29 (5): 884- 888.
19
KUO C K , MA P X . Ionically crosslinked alginate hydrogels as scaffolds for tissue engineering: part 1.structure, gelation rate and mechanical properties[J]. Biomaterials, 2001, 22, 511- 521.
doi: 10.1016/S0142-9612(00)00201-5
20
OUWERX C , VELINGS N , MESTDAGH M M , et al. Physico-chemical properties and rheology of alginate gel beads formed with various divalent cations[J]. Polymer Gels and Networks, 1998, 6, 393- 408.
doi: 10.1016/S0966-7822(98)00035-5
21
AUGST A D , KONG H J , MOONEY D J . Alginate hydrogels as biomaterials[J]. Macromolecular Bioscience, 2006, 6 (8): 623- 633.
doi: 10.1002/mabi.200600069