Bioactive glasses (6P55) used for coating Ti/Ti-alloy were tested for their in vitro behavior in a comparative study with commercial Bioglass™ (45S5) and commercial Ti alloy (Ti6Al4V). In vitro testing included pH and dissolution rate determination in simulated body fluid (SBF) along with in vitro cyto compatibility testing. It was seen in this work that 6P55 and 45S5 had similar dissolution behavior, demonstrating t½ dependence and maximum pH of approximately 8.1 after 10 days of immersion. This pH was reduce by 0.2 0.4 pH units when the in vitro V:A ratio was increased from 1 to 3. The dissolution rate of these glasses approached 0 after additional immersion tests after 15 days and the pH stablilized at less than 7.5. Cell culture studies showed that both glasses behaved in similar fashion after 16 hours in culture. Both glasses had an increase in cell numbers of close to 200-250%, whereas Ti6Al4V had a less pronounced cell number increase (∼ 180%)

The orientation distribution of crystalline grains in calcium phosphate coatings produced by pulsed laser deposition was investigated using an X-ray pole-figure diffractometer. Increased laser energy density of a KrF excimer laser in the 4–7 J/cm2 range leads to the formation of hydroxyapatite grains with the c-axis preferentially aligned perpendicularly to the substrates. This preferred orientation is most pronounced when the plume direction of incidence is normal to the substrate. This crystallographic texture of hydroxyapatite grains in the coatings is associated with the highly directional and energetic nature of the ablation plume. Anisotropic stresses, transport of hydroxyl groups, and dehydroxylation effects during deposition all seem to play important roles in texture development. Studies of cell adsorption using human Mesenchymal stem cells reveal that hydroxyapatite coatings with strong texture and random orientation show different cell adsorption behavior, which is consistent with the notion that protein attach differently on different faces of hydroxyapatite crystals. Cells seeded on textured coatings exhibit better spreading and adhesion compared to those placed on randomly oriented coatings.

3D fibrous scaffolds with shell-core fiber architecture offer the possibility to create multifunctional structures. In this study, a construct that combines mechanical stability with the core polymer and optimal surface properties for cell-material interactions with the shell polymer is discussed. Scaffolds were fabricated by a rapid prototyped technique known as 3D Fiber Deposition (3DF) and used for cartilage tissue engineering. Cells maintained the typical rounded morphology of cartilage in the shell-core scaffolds, while they spread into a spindle-like shape in scaffolds fabricated with the core polymer only. Extracellular matrix production and an increase in the dynamic stiffness of the engineered construct revealed a progressive maturation of the formed tissue, suggesting that shell-core 3D scaffolds could be optimal for cartilage tissue engineering.

The use of osseointegrated titanium implants has been related like an excellent alternative to traditional orthodontic anchorage methodologies, and they are a necessity when dental elements lack quantity or quality, when extraoral devices are impractical, or when noncompliance during treatment is likely. In orthodontics, the implants can be use to anchor different movements. However, conventional dental implants can only be placed in limited areas such as the retromolar or the edentulous areas. Another limitation has been the direction of the force application and conventional dental implants are troublesome for patients because of the severity of the surgery, the discomfort of the initial healing, and the difficulty of oral hygiene. Due to these factors, mini-implants became widely used. They have little limitations related to the local of implantation, the surgical procedure of insertion is relatively simple and the control of direction and quantify of the force is simple to be done. These improvements were obtained due to decrease of the size, but these changes could result on significant changes to the bone-implant interface. Since, the orthodontic treatment has to be done as fast as possible. The purpose of this work is to analyze the bone healing reactions to immediately loaded mini-implant of titanium alloy grade 4 by histological, fluorescent and SEM observation, by histomorphometric analysis and by removal torque test. Material and method: Seventy two mini-implants were inserted in eighteen New Zealand rabbits. Four mini-implants were put in the right tibiae of each rabbit and two of then were loaded immediately with 100 gf. Subcutaneous injections of fluorescent labels were administrated in defined periods. The animals were euthanized after 1, 4 and 12 weeks, performing three time analysis and the tibias were dissected and prepared to microcopy analysis and to removal torque test. Results: The results indicated that all the mini-implants remained stable during experimental time. The SEM findings indicated no differences between load and unload group in one and four weeks period, although, the 12 weeks loaded group demonstrated more mature bone formation than the unload group in the same time. These findings suggest that the force can be applied after insertion of the mini-implant without compromises their stability.

Bacterial adhesion is the first step in biofilm formation which impacts numerous environmental, industrial and medical processes. Examples of undesirable consequences of biofilm formation include metal rust, sewage sludge and bacteria-related diseases. Desirable consequences are biofiltration and bioremediation. Bacteria are resilient and can survive in harsh environments. A severe stress is desiccation since dehydration can damage DNA and change the properties of proteins. Some bacteria protect against dehydration by accumulating sugars such as sucrose and trehalose while others undergo a transformation from an active to a dormant state. Evaporative deposition of bacteria on a surface shows that some bacteria aggregate to form two dimensional patterns which may be important for nutrient sharing and survival in dry conditions. Since bacteria are increasingly being employed as components in biosensors and biofilm reactors, it is important to understand the material properties of bacteria in dry conditions for these applications. For a decade, Atomic Force Microscopy (AFM) has been the primary tool used to study the adhesion and elastic properties of individual bacteria. In this work we show it is possible to use a Surface Forces Apparatus (SFA) to measure elastic and adhesive properties of small collections of surface bound bacteria. The measurements are conducted with incomplete, patterned bacterial films and we have developed a protocol to image the contact area with AFM after the experiment. Using the SFA, we measured the force profile between a Pseudomonas aeruginosa PAO1 film and a bare mica surface. P. aeruginosa PAO1 is a ubiquitous gram-negative soil bacterium and is also an opportunistic pathogen. We repeated the measurement in the same contact position for six days to determine the effect of desiccation on the film material properties.