Zein regulating apatite mineralization, degradability, in vitro cells responses and in vivo osteogenesis of 3D-printed scaffold of n-MS/ZN/PCL ternary composite

Abstract

Bioactive and degradable scaffolds of nano magnesium silicate (n-MS)/zein (ZN)/poly(caprolactone) (PCL) ternary composites were prepared by 3D-printing method. The results showed that the 3D-printed scaffolds possessed controllable pore structure, and pore morphology, pore size, porosity and pore interconnectivity of the scaffolds can be efficiently adjusted. In addition, the apatite-mineralization ability of the scaffolds in simulated body fluids was obviously improved with the increase of ZN content, in which the scaffold with 20 w% ZN (C20) possessed excellent apatite-mineralization ability. Moreover, the degradability of the scaffolds was significantly enhanced with the increase of ZN content in the scaffolds.The degradation of ZN produced acidic products that could neutralize the alkaline products from the degradation of n-MS, which avoid the increase of pH value in degradable solution. Furthermore, the MC3T3-E1 cells responses (e.g. proliferation and differentiation, etc.) to the scaffolds were significantly promoted with the increase of ZN content. The in vivo osteogenesis of the scaffolds implanted the femur defects of rabbits was investigated by micro-CT and histological analysis. The results demonstrated that the new bone formation was significantly enhanced with the increase of ZN content, in which the C20 scaffold induced the highest new bone tissues, indicating excellent osteogenesis. The results suggested that the ZN in the ternary composite scaffolds played key roles in assisting bone regeneration in vivo. Fig. 1 TEM image (a) and EDS (b) of n-MS, and XRD (c) of n-MS and ZN, and XRD (d) of C0, C10 and C20 scaffolds.Fig. 3 SEM micrographs of C0 (a and b), C10 (c and d) and C20 (e and f) scaffolds under different magnification after immersed into SBF for 5 days, EDS (g) of C20 scaffold immersed into SBF for 5 days, and the change of ions concentrations with time (h) after C20 scaffold immersed into SBF.

Current Status in the Utilization of Biobased Polymers for 3D Printing Process: A Systematic Review of the Materials, Processes, and Challenges

“…Zein is a type of alcohol-soluble prolamine storage proteins in corn, which is rather rich in hydrophobic and neutral amino acids, along with some polar amino acid residues. It can be applied as a hydrophobic printable ink for different 3D printing applications, including drug delivery systems, bioengineering, and food application. ,− Since zein is an expensive protein, therefore extraction of zein and production of 3D printed objects from it would produce an important economic benefit. Moreover, the classical brittleness and flexibility drawbacks of objects produced by zein are an essential problem for their use as a free-standing 3D printed construct and more widespread application as a printable ink.…”

“…These results offered an effective method for modification of mechanical strength of 3D scaffold without application of toxic cross-linking compounds, where the PCL/zein blend scaffold manufactured by the solution-based electrohydrodynamic printer can be used in drug delivery system and bioengineering. Similar work was accomplished by Ru et al, who developed bioactive and degradable scaffolds based on magnesium silicate/zein/PCL ternary system through the 3D printing method. They reported that the in vitro apatite mineralization behavior and the scaffolds degradability were prominently enhanced upon increasing zein level.…”

In Vivo Application of Silica-Derived Inks for Bone Tissue Engineering: A 10-Year Systematic Review

“…Plant-derived organic compounds [ 58 , 59 , 65 ], animal growth factors [ 60 , 63 , 64 , 73 ], osteopontin-derived peptide [ 61 ] and decellularized matrix [ 57 ] were investigated. Overall, they all triggered an enhanced bone regeneration compared to their respective non-loaded controls.…”

Preparation and characterization of 58S bioactive glass based scaffold with Kaempferol‐containing Zein coating for bone tissue engineering

“…It was shown that the scaffolds out of Zein are biocompatible; biodegradable could promote osteogenesis differentiation making it suitable for bone tissue engineering. 21,23,24 Local and sustained delivery of bioactive molecules such as growth factors, drugs, small molecule, and metallic ions have a vital role in bone tissue engineering. 25,26 Kaempferol (3, 5, 7-trihydroxy-2-[4-hydroxyphenyl]-4H-1-benzopyran-4-one) is a herbal compound (Molecular weight: 286.2 g/mol) that is extracted from the rhizome of Kaempferia galangal.…”

“…Zein has been used for preparing tissue‐engineering scaffolds by some researchers as well. It was shown that the scaffolds out of Zein are biocompatible; biodegradable could promote osteogenesis differentiation making it suitable for bone tissue engineering 21,23,24 …”