Preparation and Characterization of β-tricalcium Phosphate/Nano Clay Composite Scaffolds via Digital Light Processing Printing

doi:10.15541/jim20210745

Abstract

Abstract:

β-tricalcium phosphate (β-TCP) has biodegradability and biocompatibility, but its inherent brittleness limits its application in load-bearing implants. In order to further improve the mechanical property and biocompatibility of β-TCP, β-TCP/NC (TNC) composite scaffold with nano clay (NC) as additive and the porous structure of the scaffold has a pore size of 200-300 μm was prepared by digital light processing (DLP) technique. When the content of NC is 10% (in mass), the sintering shrinkage of each structural feature of the support (TNC10) is the smallest. Addition of NC does not change the phase composition of TCP, and Si and Mg elements are evenly distributed on the surface of the scaffold. Addition of NC can improve the compression strength of TCP scaffolds. NC (particle size < 500 nm) is fused in the gap of TCP particles. Compared with pure TCP scaffolds, the compression strength of TNC10 is increased by 10%. In addition, the specific surface area of TNC10 group was more than 2 times higher than that of pure TCP. TNC degradation rate is faster while Ca²⁺, Mg²⁺, Si⁴⁺, and Li²⁺ can be continuously released, which maintains a weakly alkaline environment. The results demonstrate that the addition of NC has a certain promotion effect on the mechanical strength, degradation performance β-TCP scaffolds. Porous bioceramic scaffolds with good physical, chemical property by DLP method have great application prospects in the field of bone repair.

Key words: β-tricalcium phosphate, DLP printing, porous scaffold, nano clay

CLC Number:

TQ174

ZHANG Hang, HAN Kunyuan, DONG Lanlan, LI Xiang. Preparation and Characterization of β-tricalcium Phosphate/Nano Clay Composite Scaffolds via Digital Light Processing Printing[J]. Journal of Inorganic Materials, 2022, 37(10): 1116-1122.

Figures/Tables 9

Table 1 Main raw materials and reagents for preparation of porous bioceramics

Materials and reagent	Chemical agent	Dosage/% (in mass)
Ceramic powder	β-TCP	50-60
Resin monomer	PEG200DA	20-40
Crosslinking agent	3,3-Dimethylacrylic acid	2-4
Dispersant	DCA-1228	0.3-1.0
Photoinitiator	TPO	0.5
Nano clay	Laponite	0-10

Fig. 1 Schematic diagram of DLP ceramic printing equipment

Fig. 2 Surface morphologies of scaffold (a, d, g, j) Microscope photos of scaffolds; (b, e, h, k) Microscope photos of scaffolds; (c, f, i, l) SEM images of scaffolds

Fig. 3 Shrinkage of porous scaffold (a) Definition of pore and bar for porous scaffolds; (b) Sintering shrinkage of scaffolds

Fig. 4 Component analysis of porous scaffolds (a) XRD patterns of porous scaffolds; (b) EDS analysis of the surface of scaffolds

Fig. 5 Mechanical property analysis of porous scaffolds (a) Porosity and specific surface area of the scaffolds; (b) Compression strength of the scaffolds; (c) Schematic diagram of NC enhanced TCP

Fig. 6 Weight loss and pH change after scaffold degradation (a) Weight loss of scaffold after soaking in SBF for different time; (b) pH change of SBF after soaking the scaffolds

Fig. 7 Changes of ion concentration released from scaffolds soaked in SBF (a) Ca2+; (b) Mg2+; (c) Li+; (d) Si4+

Fig. 8 Surface morphologies of scaffold after degradation in SBF (a, b) TCP; (c, d) TNC2; (e, f) TNC5; (g, h) TNC10

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