Self-assembling antimicrobial peptides on nanotubular titanium surfaces coated with calcium phosphate for local therapy.

Bacterial infection is a serious medical problem leading to implant failure. The current antibiotic based therapies rise concerns due to bacterial resistance. The family of antimicrobial peptides (AMP) is one of the promising candidates as local therapy agents due to their broad-spectrum activity.

pH-Controlled Cerium Oxide Nanoparticle Inhibition of Both Gram-Positive and Gram-Negative Bacteria Growth.

Here, the antibacterial activity of dextran-coated nanoceria was examined against Pseudomonas aeruginosa and Staphylococcus epidermidis by varying the dose, the time of treatment, and the pH of the solution. Findings suggested that dextran-coated nanoceria particles were much more effective at killing P. aeruginosa and S.

Engineered Chimeric Peptides as Antimicrobial Surface Coating Agents toward Infection-Free Implants.

Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms.

pH-Dependent Activity of Dextran-Coated Cerium Oxide Nanoparticles on Prohibiting Osteosarcoma Cell Proliferation.

Cerium oxide nanoparticles (or nanoceria) have demonstrated great potential as antioxidants in various cell culture models. Despite such promise for reducing reactive oxygen species and an ability for surface functionalization, nanoceria has not been extensively studied for cancer applications to date. Herein, we engineered the surface of nanoceria with dextran and observed its activity in the presence bone cancer cells (osteosarcoma cells) at different pH values resembling the cancerous and noncancerous environment.

Reducing bacteria and macrophage density on nanophase hydroxyapatite coated onto titanium surfaces without releasing pharmaceutical agents.

Reducing bacterial density on titanium implant surfaces has been a major concern because of the increasing number of nosocomial infections. Controlling the inflammatory response post implantation has also been an important issue for medical devices due to the detrimental effects of chronic inflammation on device performance. It has recently been demonstrated that manipulating medical device surface properties including chemistry, roughness and wettability can control both infection and inflammation.

Controlling self-assembly of engineered peptides on graphite by rational mutation.

Self-assembly of proteins on surfaces is utilized in many fields to integrate intricate biological structures and diverse functions with engineered materials. Controlling proteins at bio-solid interfaces relies on establishing key correlations between their primary sequences and resulting spatial organizations on substrates. Protein self-assembly, however, remains an engineering challenge.

Biofunctionalization of materials for implants using engineered peptides.

Uncontrolled interactions between synthetic materials and human tissues are a major concern for implants and tissue engineering. The most successful approaches to circumvent this issue involve the modification of the implant or scaffold surfaces with various functional molecules, such as anti-fouling polymers or cell growth factors. To date, such techniques have relied on surface immobilization methods that are often applicable only to a limited range of materials and require the presence of specific functional groups, synthetic pathways or biologically hostile environments.

An in vitro evaluation of the Ca/P ratio for the cytocompatibility of nano-to-micron particulate calcium phosphates for bone regeneration.

Calcium phosphate based bioceramics have been widely used for orthopedic applications due to their chemical similarity to natural bone. The Ca/P stoichiometry of calcium phosphates strongly influences their performance under biological conditions, which have not yet been fully elucidated to date. For this reason, the objective of this in vitro study was to understand the relationship between the Ca/P ratio of nano-to-micron particulate calcium phosphate substrates and their biological properties, such as osteoblast (bone-forming cell) viability, collagen production, alkaline phosphatase activity and nitric oxide (NO) production.

Mechanical properties and biocompatibility of plasma-nitrided laser-cut 316L cardiovascular stents.

The effect of surface modification of laser-cut 316L cardiovascular stents by low-T plasma nitriding was evaluated in terms of mechanical properties and biocompatibility of the stents. The plasma nitriding was performed at 400, 450 or 500 degrees C using various ratios of nitrogen-hydrogen gas mixtures. The flexibility and radial strength were measured in crimped and expanded state of the stents, respectively.

BRCA1 and BRCA2 mutations in Turkish familial and non-familial ovarian cancer patients: a high incidence of mutations in non-familial cases.

Ovarian cancer is a clinically important cancer in Turkey. The contribution of BRCA1 and BRCA2 to ovarian cancer in Turkish patients has not previously been described. In this study we investigated the presence of BRCA1 and BRCA2 mutations in 102 consecutively ascertained, hospital-based, ovarian cancer cases.