2022, Vol. 26 ›› Issue (21): 3421-3428

Performance optimization of a new type of calcium silicate (based) scaffold matched with bone tissue regeneration in the bone defect area

Zhang Chunyu1, Hu Baoyang2, Feng Yao1, Zhang Wanfen1, Sun Leiye1, Yang Yan1, 3   

Abstract: BACKGROUND: Calcium silicate scaffolds have attracted more and more attention, because of their high biocompatibility, osteoinduction and osteoconduction activities, and a degree of biodegradation. However, due to the unstable osteogenic effect, fast degradation rate and poor mechanical properties of calcium silicate, it has not yet been used in clinical bone defect repair.
OBJECTIVE: To review research progress in optimizing the performance of calcium silicate scaffolds, summarize the potential and insufficiency of the single-phase calcium silicate scaffolds applied in bone defect repair, and to explore the possibility of its use in clinical bone defect repair.
METHODS: The search was performed on CNKI, Wanfang, PubMed, Elsevier, and Web of Science databases. With the keywords of “3D print, calcium silicate, osteogenesis, composite modification, angiogenesis, stress distribution, bone defect repairing” in Chinese and English, related articles in recent 20 years were retrieved. According to the inclusion and exclusion criteria, 83 papers were finally reviewed. Based on the final screening articles, the research progress and challenges of the performance optimization of calcium silicate based scaffolds in bone tissue engineering were systematically and comprehensively analyzed.
RESULTS AND CONCLUSION: (1) Calcium silicate materials have a certain potential to promote osteogenic and angiogenic differentiation of bone marrow mesenchymal stem cells, and have certain degradability. Free Ca2+ and Si4+ can induce hydroxyapatite deposition, promote collagen- I secretion and differentiation of osteoblasts, thereby increasing bone mineral density and promoting mineralization. Now, it has become one of the most promising frontier research direction in the field of bone repair. (2) However, single-phase calcium silicate scaffolds are not fully suitable for bone tissue regeneration in bone defect area in terms of mechanical properties, biological activity, and degradation rate, so it has not been widely used in clinical practice. (3) At present, there are abundant studies on the performance optimization of calcium silicate scaffolds, but there is a lack of systematic summary. In this study, through a large number of literature summary and data extraction, the performance optimization methods of calcium silicate scaffolds are classified into two categories, namely, the optimization of scaffold structure and the optimization of scaffold material composition. (4) 3D printing technology has a prominent effect on the structure optimization of calcium silicate scaffolds. By accurately regulating the porosity and pore size of the scaffolds, 3D printing technology can make the calcium silicate scaffolds have better stress distribution mode and osteogenic and angiogenic effect. (5) The optimization of the composition of calcium silicate scaffolds is based on the influence of composite materials (including inorganic ions, molecules, organic molecules, and high polymer) on the biochemical structure of scaffolds in many aspects, so as to improve mechanical properties of calcium silicate scaffolds as well as the bioinduction properties of osteogenesis and angiogenesis. (6) In conclusion, the comprehensive use of 3D printing technology and composite modification of materials is a new idea for the studies of calcium silicate scaffolds in the field of bone repair. Based on the disadvantages of single-phase calcium silicate scaffolds in the application of bone defect repair, by optimizing and modifying the structure, composition and surface conditions of the calcium silicate scaffolds, a new type of calcium silicate-based tissue engineered bone scaffold, which can effectively promote osteogenic differentiation and bone mineralization, and whose mechanical properties and degradation rate could match the regeneration of bone tissue in bone defect area, will be explored.
Key words: calcium silicate, bone defect repairing, 3D printing, composite modification, stress distribution, osteogenesis induction, angiogenesis induction, scaffolds