Fig. 5.

Representative in vivo biocompatibility of Zn-based bone implants in the literature: (a) Hard tissue sections of pure Zn, Zn-0.4Li, Zn-0.1Mn, Zn-0.8 Mg, Zn-0.8Ca, Zn-0.1Sr, Zn-0.4Fe, Zn-0.4Cu and Zn–2Ag in metaphysis. The magnified region is marked by red rectangle. NB, new bone; DP, degradation products; FT, fibrous tissue. Scale bar, 0.5 mm in low magnification, 500 μm in high magnification. (Reproduced with permissions from Ref. [109]). (b) Histological sections of mouse distal femoral shaft from Zn–1Mg, Zn–1Ca, Zn–1Sr implanted pins groups and the sham control group observed under fluorescent microscopy at week 8. (Reproduced with permissions from Ref. [132]). (c) Histological section of Zn-0.05 Mg implanted in rabbit tibial shaft for 24 weeks. There are normal cortical bones (blue arrow); implant (white arrow); newly formed bone fractions around the implant (red arrow); bone junction between cortical bone and new bone formation (green arrow). (Reproduced with permissions from Ref. [107]). (d) Hard tissue sections of the Zn-0.1Li alloy after 8 and 12 weeks' implantation in rat femur condyle. (Reproduced with permissions from Ref. [135]). Hard tissue sections of (e) pure Zn (Reproduced with permissions from Ref. [146]), (f) Zn-5HA composite (Reproduced with permissions from Ref. [146]) and (g) Zn–5Mg composite (Reproduced with permissions from Ref. [145]) fabricated by spark plasma sintering after being implanted in the rat femur condyle for 4 and 8 weeks. The red rectangles correspond to the magnified bone-implant interface. The red triangle indicates newly formed bone. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)