Biomedical Ti-Nb-Zr Foams Prepared by Means of Thermal Dealloying Process and Electrochemical Modification

The paper presents results of preparation and modification of Ti20Nb5Zr foams by a thermal dealloying method followed by electrochemical modification. The first step of this study was the preparation of Ti20Nb5Zr30Mg nanopowder using mechanical alloying (MA). The second was forming green compacts by cold pressing and then sintering with magnesium dealloyed from the structure, which resulted in pores formation. The next step was surface modification by electrochemical etching and silver nanoparticle deposition. Porosity, morphology, mechanical properties as well as biocompatibility and antibacterial behavior were investigated. Titanium foam porosity up to approximately 60% and wide pore size distribution were successfully prepared. The new materials have shown positive behavior in the MTT assay as well as antibacterial properties. These results confirmed great potential for thermal dealloying in preparation of porous structures.

Ultrafine-Grained Ti-31Mo-Type Composites with HA and Ag, Ta2O5 or CeO2 Addition for Implant Applications

Ultrafine-grained Ti31Mo alloy and Ti31Mo5HA, Ti31Mo5HA-Ag (or Ta₂O₅, CeO₂) composites with a grain size of approximately 2 μm were produced by the application of mechanical alloying and powder metallurgy. Additionally, the surface of the Ti31Mo alloy was modified. In the first stage, the specimens were immersed in 5M NaOH for 24 h at 60 °C. In the second stage, hydroxyapatite (HA) was deposited on the sample surface. The cathodic deposition at −5 V vs. open circuit potential (OCP) in the electrolyte containing 0.25M CaNa₂-EDTA (di-calcium ethylenediaminetetraacetic acid), 0.25M K₂HPO₄ in 1M NaOH at 120 °C for 2 h was applied. The bulk Ti31Mo alloy is a single β-type phase. In the alkali-modified surface titanium oxide, Ti₃O is formed. After hydrothermal treatment, the surface layer mostly consists of the Ca₁₀(PO₄)₆(OH)₂ (81.23%) with about 19% content of CaHPO₄·2H₂O. Using optical profiler, roughness 2D surface topography parameters were estimated. The in vitro cytocompatibility of synthesized materials was studied. The cell lines of normal human osteoblasts (NHost) and human periodontal ligament fibroblasts (HPdLF) was conducted in the presence of tested biomaterials. Ultrafine-grained Ti-based composites altered with HA and Ag, Ta₂O₅ or CeO₂ have superior biocompatibility than the microcrystalline Ti metal. NHost and HPdLF cells in the contact with the synthesized biomaterial showed stable proliferation activity. Biocompatibility tests carried out indicate that the ultrafine-grained Ti31Mo5HA composites with Ag, Ta₂O_5, or CeO₂ could be a good candidate for implant applications.

Response of inflammatory cells to biodegradable ultra-fine grained Mg-based composites

Ultra-fine grained biodegradable Mg-based Mg1Zn1Mn0.3 Zr - HA and Mg4Y5.5Dy0.5 Zr - 45S5 Bioglass composites have shown great medical potential. Two types of these Mg-based biomaterials subjected to different treatments were tested and as shown earlier they are biocompatible. The aim of the study is to determine how much culture media incubated with these ultra-fine trained Mg-based composites can cause inflammatory reactions and /or periodontal cell death. The incubation of composites in the medium releases metal ions into the solution. It can be assumed that this process is permanent and also occurs in the human body. The results have shown that the effect of proinflammatory IL-6 and TNF- cytokines results in the strongest production of the acute phase proteins in the first day on the Mg1Zn1Mn0.3 Zr-5 wt.% HA-1 wt. % Ag HF-treated biocomposite after immersion for 2 h in 40 % HF and then the fastest decrease in these processes on the third day. In turn, the inflammatory process induced on the Mg1Zn1Mn0.3 Zr-5 wt.% HA-1 wt. % Ag biomaterial, in BAX / BCL ratio assessment, is the strongest on the third day and maintains a significantly high level on the following day, which, at the same time, confirms its persistence and development. In addition, these results confirm the successively generated necrotic processes. Ions can induce inflammatory reactions, which in the case of the implant may take a long time, which results in the loss of the implant. Even if the material is biocompatible in rapid in-vitro tests, it can induce inflammation in the body after some time due to the release of ions. Not every treatment improves the material's properties in terms of subsequent safety.

Molecular analysis of biocompatibility of anodized titanium with deposited silver nanodendrites

Titanium (>99.6% purity) and its anodically oxidized modifications, with and without deposited silver nanodendrites regarding its biocompatibility were evaluated. In human gingival fibroblasts and osteoblast cell lines grown on tested samples, the level of expression of genes encoding αV (ITGAV) and β1 (ITGB1) integrin subunits also genes encoding focal adhesion (FAK) and extracellular-signal regulated (ERK) kinases was assessed. For this purpose, the qualitative and quantitative PCR technique was used. The expression of studied genes was dependent on the origin of cell lines and the type of evaluated material. The high expression of PBGD and ITGAV genes in fibroblasts grown on the surface of anodically modified titanium with deposited silver nanodendrites indicates potentially high biocompatibility of these samples for soft tissue cells. The high expression of the ITGB1 and ERK1 genes and the enhanced expression of the FAK gene in osteoblasts cells grown on the tested material was also observed. Summarizing, the nanocrystalline Ti modified with silver deposits showed higher biocompatibility in comparison with the conventional pure Ti samples.

The knowledge of risk factors and prevention of breast cancer in Polish women

PURPOSE

Currently, breast cancer is one of the most common malignancies among women and it constitutes a significant medical, economic, and social problem.

MATERIALS AND METHODS

The study was conducted in a group of 600 healthy women (aged 18 to 88 years) between September 2011 and February 2015 living in the region of Wielkopolska (Poland) in a private gynecological practice. A survey questionnaire designed specifically for purposes of the study was a tool used to conduct the study.

RESULTS

With regards to risk factors for breast cancer: 93% - familial history of breast cancer, 46% - use of hormone treatment, and 40.16% - taking contraceptive pills.

CONCLUSIONS

A significant component of breast cancer prevention should be providing information regarding prevention tests and increasing accessibility to medical services.

Development of β Type Ti23Mo-45S5 Bioglass Nanocomposites for Dental Applications

Titanium β-type alloys attract attention as biomaterials for dental applications. The aim of this work was the synthesis of nanostructured β type Ti23Mo-x wt % 45S5 Bioglass (x = 0, 3 and 10) composites by mechanical alloying and powder metallurgy methods and their characterization. The crystallization of the amorphous material upon annealing led to the formation of a nanostructured β type Ti23Mo alloy with a grain size of approximately 40 nm. With the increase of the 45S5 Bioglass contents in Ti23Mo, nanocomposite increase of the α-phase is noticeable. The electrochemical treatment in phosphoric acid electrolyte resulted in a porous surface, followed by bioactive ceramic Ca-P deposition. Corrosion resistance potentiodynamic testing in Ringer solution at 37 °C showed a positive effect of porosity and Ca-P deposition on nanostructured Ti23Mo 3 wt % 45S5 Bioglass nanocomposite. The contact angles of glycerol on the nanostructured Ti23Mo alloy were determined and show visible decrease for bulk Ti23Mo 3 wt % 45S5 Bioglass and etched Ti23Mo 3 wt % 45S5 Bioglass nanocomposites. In vitro tests culture of normal human osteoblast cells showed very good cell proliferation, colonization, and multilayering. The present study demonstrated that porous Ti23Mo 3 wt % 45S5 Bioglass nanocomposite is a promising biomaterial for bone tissue engineering.

In vitro biocompatibility of Ti-45S5 bioglass nanocomposites and their scaffolds

Titanium-10 wt % 45S5 Bioglass nanocomposites and their scaffolds were prepared by mechanical alloying (MA) followed by pressing, sintering, or combination of MA and a "space-holder" sintering process, respectively. An amorphous structure was obtained at 15 h of milling. The crystallization of the amorphous phase upon annealing led to the formation of a nanostructured Ti-10 wt % 45S5 Bioglass composite with a grain size of approximately 7 nm. The in vitro cytocompatibility of these materials was evaluated and compared with a conventional microcrystalline titanium. During the studies, established cell line of human fibroblasts CCD-39Lu was cultured in the presence of tested materials and its survival rate, and proliferation activity were examined. Furthermore, the influence of the Ti-45S5 Bioglass nanocomposites and microcrystalline titanium was tested on the growth of Candida albicans yeast. Biocompatibility tests carried out indicate that the nanocomposite Ti-10 wt % 45S5 Bioglass scaffolds could be a possible candidate for dental implants and other medicinal applications.