A meta-analysis review of the effect of Zn-doped synthetic polymer materials on bone regeneration

Introduction: Using the alternative compounds, such as ceramics, metals, natural and synthetic polymers, and their combination was mentioned for the bone regeneration. Many synthetic polymers were used to regenerate bone in recent years to eliminate bone defects. The advantages of these polymers include biocompatibility, biodegradability, and low toxicity. However, they cannot create ideal ossification when these compounds are used alone. Zinc (Zn) has been recently shown to enhance ossification in stem cells and is used in various polymers. The purpose of this PRISMA-compliant meta-analysis was to examine the efficacy of synthetic polymers alone and in combination with zinc for bone regeneration. Materials and methods: A search of four databases, PubMed, Embase, Cochrane Library, and Google Scholar, as of June 2021, found 163 related studies. Then, based on the titles, abstracts, and full texts, they were screened, and finally, 10 articles were selected. Results: Low concentrations of Zn²⁺ stimulated cell proliferation and differentiation towards osteogenesis, but high concentrations of Zn²⁺ caused cytotoxicity and inhibited ossification differentiation. Furthermore, polymers doped with zinc ions are more capable of bone regeneration. Conclusion: Using appropriate concentrations of zinc in polymeric materials compared to zinc-free materials can play an influential role in the bone regeneration.