Dynamic Adhesive Behavior and Biofilm Formation of on Polylactic Acid Surfaces in Diabetic Environments.

Interest in biodegradable implants has focused attention on the resorbable polymer polylactic acid. However, the risk of these materials promoting infection, especially in patients with existing pathologies, needs to be monitored. The enrichment of a bacterial adhesion medium with compounds that are associated with human pathologies can help in understanding how these components affect the development of infectious processes.

Electrodeposited Zinc Coatings for Biomedical Application: Morphology, Corrosion and Biological Behaviour.

The improvement of biodegradable metals is currently an active and promising research area for their capabilities in implant manufacturing. However, controlling their degradation rate once their surface is in contact with the physiological media is a challenge. Surface treatments are in the way of addressing the improvement of this control.

Thermodynamic Characterization of Rhamnolipid, Triton X-165 and Ethanol as well as Their Mixture Behaviour at the Water-Air Interface.

In many industrial fields, in medicine or pharmacy, there are used multi-component mixtures of surfactants as well as more and more often mixtures containing biosurfactants. Thus, in our study the mixtures of rhamnolipid (RL), ethanol (ET) and Triton X-165 (TX165) were applied. For these mixtures the surface tension of aqueous solutions with constant concentration and composition of ET and RL as well as the variable concentration of TX165 was measured.

Bacterial Response to the Surface Aging of PLA Matrices Loaded with Active Compounds.

The use of active components in biomaterials improves the properties of existing ones and makes it possible to obtain new devices with antibacterial properties that prevent infections after implantation, thus guaranteeing the success of the implant. In this work, cetyltrimethylammonium bromide (CTAB) and magnesium particles were incorporated into polylactic acid (PLA) films to assess the extent to which progressive aging of the new surfaces resists bacterial colonization processes. For this purpose, the films' surface was characterized by contact angle measurements, ToF-SIMS and AFM, and adhesion, viability and biofilm growth of bacteria on these films were also evaluated.

Effect of Spontaneous and Water-Based Passivation on Components and Parameters of Ti6Al4V (ELI Grade) Surface Tension and Its Wettability by an Aqueous Solution of Sucrose Ester Surfactants.

Solid wettability is especially important for biomaterials and implants in the context of microbial adhesion to their surfaces. This adhesion can be inhibited by changes in biomaterial surface roughness and/or its hydrophilic-hydrophobic balance. The surface hydrophilic-hydrophobic balance can be changed by the specifics of the surface treatment (proper conditions of surface preparation) or adsorption of different substances.

Influence of Solvent and Substrate on Hydrophobicity of PLA Films.

The study of the surface properties of materials is key in determining whether the material will be suitable for medical purposes. One of these properties is hydrophobicity, which is important when assessing its behavior against bacterial adhesion. In this work, we have studied the influence of the solvent (chloroform, acetone, and tetrahydrofuran) and the substrate (glass, PTFE, silicone, and Ti6Al4V) on which polylactic acid is deposited in solution to manufacture films by solvent-casting.

Surface Characterisation of Human Serum Albumin Layers on Activated Ti6Al4V.

Adpsortion of protein layers on biomaterials plays an important role in the interactions between implants and the bio-environment. In this context, human serum albumin (HSA) layers have been deposited on modified Ti6Al4V surfaces at different ultraviolet (UV-C) irradiation times to observe possible changes in the adsorbed protein layer. Protein adsorption was done from solutions at concentraions lower than the serum protein concentration, to follow the surface modifications at the beginning of the albumin adhesion process.

Force spectroscopy-based simultaneous topographical and mechanical characterization to study polymer-to-polymer interactions in coated alginate microspheres.

Cell-laden hydrogel microspheres have shown encouraging outcomes in the fields of drug delivery, tissue engineering or regenerative medicine. Beyond the classical single coating with polycations, many other different coating designs have been reported with the aim of improving mechanical properties and in vivo performance of the microspheres. Among the most common strategies are the inclusion of additional polycation coatings and the covalent bonding of the semi-permeable membranes with biocompatible crosslinkers such as genipin.

Bacterial response to spatially organized microtopographic surface patterns with nanometer scale roughness.

In this study, the influence of nanometer scale roughness on bacterial adhesion and subsequent biofilm formation has been evaluated using spatially organized microtopographic surface patterns for four major opportunistic pathogens of the genus Staphylococcus (S. epidermidis and S. aureus) responsible for associated-biofilm infections on biomedical devices.

Corrosion behavior of surface modifications on titanium dental implant. In situ bacteria monitoring by electrochemical techniques.

The effects of surface modifications and bacteria on the corrosion behavior of titanium have been studied. Five surface modifications were analyzed: two acid etchings (op V, op N), acid etching + anodic oxidation (op NT), sandblasting + acid etching (SLA), and machined surfaces (mach). The corrosion behavior of the surface modifications was evaluated by following the standard ANSI/AAMI/ISO 10993-15:2000.

Balancing microbial and mammalian cell functions on calcium ion-modified implant surfaces.

Implant integration is a complex process mediated by the interaction of the implant surface with the surrounding ions, proteins, bacteria, and tissue cells. Although most implants achieve long-term bone-tissue integration, preventing pervasive implant-centered infections demands further advances, particularly in surfaces design. In this work, we analyzed classical microrough implant surfaces (only acid etched, AE; sandblasted then acid etching, SB + AE) and a new calcium-ion-modified implant surface (AE + Ca) in terms of soft- and hard-tissue integration, bacterial adhesion, and biofilm formation.

Direct Covalent Grafting of Phytate to Titanium Surfaces through Ti-O-P Bonding Shows Bone Stimulating Surface Properties and Decreased Bacterial Adhesion.

Myo-inositol hexaphosphate, also called phytic acid or phytate (IP6), is a natural molecule abundant in vegetable seeds and legumes. Among other functions, IP6 inhibits bone resorption. It is adsorbed on the surface of hydroxyapatite, inhibiting its dissolution and decreasing the progressive loss of bone mass.

Quercitrin-nanocoated titanium surfaces favour gingival cells against oral bacteria.

Many dental implants fail due to the infection and inflammation that walk hand in hand with poor healing and soft tissue integration. Titanium surfaces were nanocoated with quercitrin, a natural flavonoid, with the aim to improve soft tissue integration and increase dental implants success. Streptococcus mutans attachment and biofilm formation was analysed.

On the interactions of human bone cells with Ti6Al4V thermally oxidized by means of laser shock processing.

We investigated a Ti6Al4V alloy modified by means of laser peening in the absence of sacrificial coatings. As a consequence of the temperature rise during laser focusing, melting and ablation generated an undulated surface that exhibits an important increase in the content of titanium oxides and OH- ions. Human mesenchymal stem cells and osteoblasts cultured on the oxidized alloy develop noticeable filopodia and lamellipodia.

Incorporation of Mg particles into PDLLA regulates mesenchymal stem cell and macrophage responses.

In this work, we investigated a new approach to incorporate Mg particles within a PDLLA matrix using a solvent-free commercially available process. PDLLA/Mg composites were manufactured by injection moulding and the effects of Mg incorporated into PDLLA on MSC and macrophage responses were evaluated. Small amounts of Mg particles (≤ 1 wt %) do not cause thermal degradation of PDLLA, which retains its mechanical properties.

Bioinspired Quercitrin Nanocoatings: A Fluorescence-Based Method for Their Surface Quantification, and Their Effect on Stem Cell Adhesion and Differentiation to the Osteoblastic Lineage.

Polyphenol-based coatings have several potential applications in medical devices, such as cardiovascular stents, contrast agents, drug delivery systems, or bone implants, due to the multiple bioactive functionalities of these compounds. In a previous study, we fabricated titanium surfaces functionalized with flavonoids through covalent chemistry, and observed their osteogenic, anti-inflammatory, and antifibrotic properties in vitro. In this work, we report a fluorescence-based method for the quantification of the amount of flavonoid grafted onto the surfaces, using 2-aminoethyl diphenylborinate, a boronic ester that spontaneously forms a fluorescent complex with flavonoids.

Surface Topographical Changes of a Failing Acid-Etched Long-Term in Function Retrieved Dental Implant.

The aim of the present study was to report the main topographical and chemical changes of a failing 18-year in function retrieved acid-etching implant in the micro- and nanoscales. A partially edentulous 45 year old rehabilitated with a dental implant at 18 years of age exhibited mobility. After careful examination, a 3.

Flavonoid-modified surfaces: multifunctional bioactive biomaterials with osteopromotive, anti-inflammatory, and anti-fibrotic potential.

Flavonoids are small polyphenolic molecules of natural origin with antioxidant, anti-inflammatory, and antibacterial properties. Here, a bioactive surface based on the covalent immobilization of flavonoids taxifolin and quercitrin on titanium substrates is presented, using (3-aminopropyl)triethoxysilane (APTES) as coupling agent. FTIR and XPS measurements confirm the grafting of the flavonoids to the surfaces.

Studying the influence of surface topography on bacterial adhesion using spatially organized microtopographic surface patterns.

The influence of surface topography on bacterial adhesion has been investigated using a range of spatially organized microtopographic surface patterns generated on polydimethylsiloxane (PDMS) and three unrelated bacterial strains. The results presented indicate that bacterial cells actively choose their position to settle, differentiating upper and lower areas in all the surface patterns evaluated. Such selective adhesion depends on the cells' size and shape relative to the dimensions of the surface topographical features and surface hydrophobicity/hydrophilicity.

Three-dimensional and chemical changes on the surface of a 3-year clinically retrieved oxidized titanium dental implant.

Objective: To report the main topographical features in the micro- and nano-scales and to assess implant chemical changes of the surface of a 3-year clinically retrieved oxidized titanium dental implant, and compare them with a similar, unused implant.

Materials And Methods: The surface of the oxidized titanium dental implants was assessed by surface electron microscopy (SEM) analysis at increasing magnifications. X-ray photoelectron spectroscopy (XPS) measurement was performed to analyze the implants surface chemistry.

Effect of two hydrocarbon and one fluorocarbon surfactant mixtures on the surface tension and wettability of polymers.

The advancing contact angle of water, formamide and diiodomethane on polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) surfaces covered with the film of ternary mixtures of surfactants including p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethyleneglycols), Triton X-100 (TX100) and Triton X-165 (TX165) and the fluorocarbon surfactants, Zonyl FSN-100 (FSN100) or Zonyl FSO-100 (FSO100) was measured. The obtained results were used for the surface tension of PTFE and PMMA covered with this film determination from the Young equation on the basis of van Oss et al. and Neumann et al.

Functional living biointerphases.

Lactococcus lactis is modified to express a fibronectin fragment (FNIII₇₋₁₀) as a membrane protein. This interphase, based on a living system, can be further exploited to provide spatio-temporal factors to direct cell function at the material interface. This approach establishes a new paradigm in biomaterial surface functionalization for biomedical applications.

Ultrasmall liquid droplets on solid surfaces: production, imaging, and relevance for current wetting research.

The investigation of micro- and nanoscale droplets on solid surfaces offers a wide range of research opportunities both at a fundamental and an applied level. On the fundamental side, advances in the techniques for production and imaging of such ultrasmall droplets will allow wetting theories to be tested down to the nanometer scale, where they predict the significant influence of phenomena such as the contact line tension or evaporation, which can be neglected in the case of macroscopic droplets. On the applied side, these advances will pave the way for characterizing a diverse set of industrially important materials such as textile or biomedical micro- and nanofibers, powdered solids, and topographically or chemically nanopatterned surfaces, as well as micro-and nanoscale devices, with relevance in diverse industries from biomedical to petroleum engineering.

In vitro biocompatibility of an ultrafine grained zirconium.

We have investigated a novel ultrafine grained (UFG) Zr obtained by severe plastic deformation (SPD) which resulted in a refinement of the grain size by several orders of magnitude. Compared to conventional Zr, higher hardness values were measured on UFG Zr. Polished surfaces having similar topographical features from both materials were prepared, as assessed by atomic force microscopy (AFM).

Ultrastructural and physico-chemical heterogeneities of yeast surfaces revealed by mapping lateral-friction and normal-adhesion forces using an atomic force microscope.

Scanning force microscopy has been used to probe the surface of the emerging pathogenic yeast Candida parapsilosis, in order to get insight into its surface structure and properties at submicrometer scales. AFM friction images eventually show patches with a very strong contrast, showing high lateral interaction with the tip. Adhesion force measurement also reveals a high normal interaction with the tip, and patches show extraordinarily high pull off values.