Fig. 2

The process of ZIF-8 inducing biomimetic mineralization spontaneously. a) SEM and TEM-EDS analysis results presented that ZIF-8 particles had characteristic rhombic dodecahedral architecture and Zn-N skeleton elements. b). Quantification of elemental mapping for mineralized ZIF-8 NPs in panel e. c) XRD patterns displaying the pure phase for our prepared ZIF-8 (red line). ZIF-8 particles experienced partial collapse in SBF over time. Novel diffraction peaks appeared, suggesting that novel crystal structures were formed. d) By comparing FTIR spectroscopy on ZIF-8 particles prior to and following incubation in SBF (day 21), ZIF-8 degradation was related to ligand release and ion coordination environment alteration. e) TEM-EDS mapping images for ZIF-8 particles revealed the changes of composition and morphology in SBF as time goes on. Mineralized ZIF-8 possessed Ca, P and Zn elements as well as distinct agglomeration. f) ZIF-8 particle size following mineralization (day 21) obviously increased in relative to the initial size. g) Following mineralization (day 21), ZIF-8 had changed zeta potential and distribution from negative to positive. h) Zn²⁺ and Ca²⁺ contents in SBF suggested that Zn ions were released and bound to Ca ions in incubation. i) Quantification of 2-methylimidazole content in SBF revealed that ligand was released through protonation