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Zinc (Zn)-based composites are promising biodegradable bone-implant materials because of their good biocompatibility, processability, and biodegradability. Nevertheless, the low interfacial bonding strength, coordinated deformation capacity, and mechanical strength of current Zn-based composites hinder their clinical application. In this study, we developed a biodegradable in situ4Mg2Ge/Zn-0.3Cu-0.05P composite (denoted ZMGCP) via phosphorus (P) modification and hot-rolling for bone-implant applications. The mechanical properties, corrosion behavior, biotribological performance, in vitrocytocompatibility and osteogenic differentiation, and in vivoosteogenesis and osteointegration of the as-cast (AC) and hot-rolled (HR) ZMGCP samples were systematically evaluated and compared to those of 4Mg2Ge/Zn-0.3Cu (denoted ZMGC). The primary and eutectic reinforcement Mg2Ge phases formed during solidification were refined after P modification and hot-rolling. The HR ZMGCP exhibited the best tensile properties among all the samples with an ultimate tensile strength of 288.9 MPa, a yield strength of 194.5 MPa, and an elongation of 17.7 %. The HR ZMGCP showed the lowest corrosion rate of 336 μm/a, 186 μm/a, and 61.7 μm/a as measured by potentiodynamic polarization, electrochemical impedance spectroscopy, and immersion testing, respectively, among all the samples in Hanks’ solution. The HR ZMGCP also showed higher biotribological resistance than its ZMGC counterpart. The HR ZMGCP exhibited the highest in vitrocytocompatibility, the best osteogenesis capability and angiogenesis property among the HR samples of pure Zn, ZMGC, and ZMGCP. Furthermore, the HR ZMGCP displayed complete in vivobiocompatibility, osteogenesis, osteointegration capability, and an appropriate degradation rate, showing significant potential for a biodegradable bone-implant material.

The difficulty in periodontal ligament healing significantly limits the clinical application of natural tooth replantation. Root surface conditioning can enhance periodontal membrane recovery and increase the success rate of natural tooth replantation. This study explored the effect and mechanism of the skin secretion of Andrias davidianus (SSAD) to promote periodontal ligament healing, as a novel root conditioner.

Zinc (Zn)-based composites have been received adequate attention lately in the biomedical field as degradable biomaterials owing to their simple preparation process, inherent biodegradability, intrinsic biological activity, and good biocompatibility. Nevertheless, the low mechanical strength and fast corrosion rate of Zn-based composites caused by a large number of coarse reinforcement particles have severely impeded their further clinical application. This work reports a promising method to fabricate an in situbiodegradable Zn–5Mg2Ge composite with high mechanical properties, wear resistance, corrosion resistance, and cytocompatibility via high-intensity ultrasonication and followed by hot-rolling. After hot rolling, the ultrasonicated Zn–5Mg2Ge composite exhibited the best mechanical properties and hardness with a yield strength, an ultimate tensile strength, elongation, Vickers hardness, and Brinell hardness of 142.9 MPa, 253.6 MPa, 8.9%, 109.5 HV, and 104.0 HB, respectively. Further, the ultrasonicated Zn–5Mg2Ge composite after hot-rolling exhibited significantly higher corrosion and wear resistance than its un-ultrasonicated counterpart in Hanks’ solution. The diluted extract (12.5% concentration) of the.