Commercially available titanium (Ti) alloys, such as Ti–6Al–4V and c.p. Ti, even though established in clinical use as load-bearing bone implant materials in orthopedics and dentistry, possess significant drawbacks that may lead to implant failure: i) presence of alloying elements with harmful health effects, ii) high Young’s modulus (E > 100 GPa) compared to human cortical bone (Ebone = 10 – 30 GPa), and iii) lack of antibacterial activity against multidrug-resistant bacteria, which may lead to implant-associated infections. To overcome the first two drawbacks, a new generation of biocompatible metastable β-type Ti alloys has been developed, in particular β-type Ti–Nb alloys, which are versatile candidates due to their low Young’s modulus, high strength-to-weight ratio and improved corrosion resistance. The present work aims to tackle all three aforementioned issues by developing novel β-type Ti–45Nb-based alloys with potential intrinsic antibacterial activity by adding antibacterial gallium (Ga) and copper (Cu) in minor amounts (up to 8 wt.%) via metallurgical route. Nine alloys with the following chemical compositions: (100-x)(Ti–45Nb)–xGa, (100-x)(Ti–45Nb)–xCu (where x = 2, 4, 6, 8 wt.%), and 96(Ti–45Nb)–2Ga–2Cu, based on alloy design approaches, were produced by controlled casting and homogenization treatment. The effect of antibacterial alloying additions on phase constitution, mechanical characteristics, corrosion, and tribocorrosion response in a simulated physiological environment has been investigated. All nine alloys in the homogenized state display a single-phase β (BCC) phase microstructure, whose lattice parameter is proved to be sensitive to Ga and Cu content, with an almost linear contraction. The mechanical characteristics are strongly influenced by Ga and Cu addition, with a general strengthening effect mainly attributed to substitutional solid solution strengthening, and to grain boundary strengthening in case of Ga. Deformation behavior indicates high mechanical stability of the β phase, suggesting dislocation slip as dominant deformation mechanism. The results demonstrate that strategic alloy design is an effective method to significantly increase strength without adversely affecting the Young’s modulus, which remains in the range of good biomechanical compatibility (E = 64 – 104 GPa). Evaluation of the corrosion response and metal ion release in simulated physiological environment demonstrates the high corrosion resistance of the nine alloys, whereas tribocorrosion wear resistance increases upon Ga addition. Further thermal (aging) treatments, carried out on a specific Cu-containing alloy, proved the feasibility of tailoring enhanced mechanical, chemical and potentially antibacterial properties by thermally-induced precipitation of Ti₂Cu intermetallic compound. These novel developed alloys are considered to be promising candidates for biomedical bone implant applications.

To investigate and assess bone regeneration in sheep in combination with new implant materials classical histological staining methods as well as immunohistochemistry may provide additional information to standard radiographs or computer tomography. Available published data of bone defect regenerations in sheep often present none or sparely labeled histological images. Repeatedly, the exact location of the sample remains unclear, detail enlargements are missing and the labeling of different tissues or cells is absent. The aim of this article is to present an overview of sample preparation, staining methods and their benefits as well as a detailed histological description of bone regeneration in the sheep tibia. General histological staining methods like hematoxylin and eosin, Masson-Goldner trichrome, Movat’s pentachrome and alcian blue were used to define new bone formation within a sheep tibia critical size defect containing a polycaprolactone-co-lactide (PCL) scaffold implanted for 3 months (n = 4). Special attention was drawn to describe the bone healing patterns down to cell level. Additionally one histological quantification method and immunohistochemical staining methods are described.

To investigate and assess bone regeneration in sheep in combination with new implant materials classical histological staining methods as well as immunohistochemistry may provide additional information to standard radiographs or computer tomography. Available published data of bone defect regenerations in sheep often present none or sparely labeled histological images. Repeatedly, the exact location of the sample remains unclear, detail enlargements are missing and the labeling of different tissues or cells is absent. The aim of this article is to present an overview of sample preparation, staining methods and their benefits as well as a detailed histological description of bone regeneration in the sheep tibia. General histological staining methods like hematoxylin and eosin, Masson-Goldner trichrome, Movat’s pentachrome and alcian blue were used to define new bone formation within a sheep tibia critical size defect containing a polycaprolactone-co-lactide (PCL) scaffold implanted for 3 months (n = 4). Special attention was drawn to describe the bone healing patterns down to cell level. Additionally one histological quantification method and immunohistochemical staining methods are described.