Types Of Surface Modifications Research Articles

Development of a Bioactive Titanium Surface via Alkalinization and Naringenin Coating for Peri-Implant Repair: In Vitro Study

This study assessed the effects of titanium (Ti) surface modification with sodium hydroxide (NaOH) associated or not with Naringenin (NA) citrus flavonoid-coating on osteoblastic-like cells (Ob) metabolism. Ti discs were submitted to alkalinization by NaOH solution (5 M, 60 °C) for 24 h; then, the discs were impregnated or not with 100 µg/mL of NA and dried for 1 h at room temperature. The chemical composition, surface topography, and NA release were evaluated. For the biological assays, the discs were placed on 24-well cell culture plates and Ob (Saos-2; ATCC HTB-85) was seeded onto the discs. After different periods, cell adhesion and viability, alkaline phosphatase activity (ALP), and mineralized nodules deposition (MND) were assessed. In addition, cells stimulated with tumor necrosis factor-alpha (TNF-α) were submitted to matrix metalloproteinase (MMP)-2 synthesis and ALP gene expression assessment. Since data presented normal distribution and homogeneity (Shapiro-Wilk; Levene), Student’s t-test or one-way ANOVA/post-hoc tests were selected for data analysis (α = 0.05). Higher roughness was observed on Ti discs submitted to NaOH treatment, while the chemical and NA release evaluations indicated the successful adsorption of NA to alkali-treated Ti surface. Higher cell adhesion, cell viability (after 7 days of culture), ALP activity, and MND were observed on Ti NaOH coated with NA compared to the control group (Ti NaOH) (p < 0.05). Moreover, NA coating also promoted decreased MMP-2 synthesis and increased ALP gene expression in the presence of the inflammatory stimulus TNF-α (p < 0.05). The modification of Ti disks with NaOH associated with NA-coating enhanced bone cell metabolism, suggesting that this type of surface modification has a promising potential to accelerate bone repair and formation around dental implants.

Deposition and corrosion performance of phosphate-polylactic acid composite coatings on WE43 magnesium alloy

The degradation profile of Mg alloys in biomedical environments can be controlled by applying various types of surface coatings. Phosphate chemical conversion coatings (CaP) and polylactic acid (PLA) biopolymer coatings are biocompatible and promising for the corrosion protection of Mg alloys. The aim of this work was to investigate the physicochemical properties and corrosion performance of inorganic, organic, and mixed inorganic-organic coatings. Three types of surface modification, CaP, PLA, and a combined CaP-PLA coating were obtained on the surface of the magnesium alloy WE43. Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and infrared spectroscopy were employed to characterize the surface and interfacial morphology, along with the composition of the coatings before and after corrosion experiments. The protective performance of obtained coatings was examined by electrochemical impedance spectroscopy and immersion testing in Hank's solution. Coated samples showed significantly improved corrosion resistance. The values of polarization resistance based on impedance measurements were 164; 8688; 69,410; and 228,369 Ω cm2 for WE43 alloy, CaP, PLA, and CaP-PLA coatings, respectively. The results allowed to propose the mechanism of the coatings growth and their further corrosion degradation. A two-component CaP-PLA coating provided reliable corrosion resistance in Hank's solution for 14 days.

Fibroblast Viability Through Mechanical and Chemical Root Surface Modifications in Periodontal Healing: An In Vitro Comparative Study.

The wound-healing process incorporates a spectrum of periodontal therapeutic interventions that strive to restore the health and function of the periodontium. Fibroblasts play pivotal roles in tissue repair and regeneration. Extensive research has been focused on mechanical and chemical root surface modifications to enhance fibroblast adhesion, which is crucial for successful wound healing. This study aimed to assess the combined efficacy of mechanical and chemical root surface modifications in promoting fibroblast viability to root surfaces affected by periodontitis in comparison to chemical modifications alone. Root samples were collected from healthy individuals and those with advanced periodontitis. The specimens were prepared, and the experimental groups were categorized based on the type of surface modification with mechanical and/or chemical materials, including hyaluronic acid (HA), ethylenediaminetetraacetic acid(EDTA), enamel matrix derivatives (EMD), and EDTA/EMD. Fibroblasts were seeded onto previously treated root samples. Cell adhesion was assessed using a viability assay. Fibroblast viability was significantly higher on root surfaces treated with chemical agents than on those treated with mechanical and chemical modifications. Long-duration EDTA and short-duration EMD treatments were significantly effective in enhancing cell viability. EDTA/EMD surface treatments resulted in significantly higher cell viability in all groups compared to the periodontitis root surfaces. EDTA, EMD, and their combined application can potentially ameliorate periodontitis-induced surface structural impairments. Mechanical surface debridement can significantly affect the effectiveness of EDTA and EMD root conditioning agents.

Studies of the Solid Particle Erosion Resistance of 30 L Steel with Different Types of Surface Modification

Earlier studies have shown that 30 L steel, used for the manufacture of hydraulic machinery equipment elements, has greater resistance to cavitation wear than 20 GL steel. This paper presents the results of experimental studies of the solid particle erosion resistance of 30 L structural steel samples with different surface modifications based on nitriding and boriding processes. The characteristics of the modified near-surface layers were determined. The results of the solid particle erosion resistance tests carried out according to the ASTM G76-13 standard are presented. The research results demonstrated that boriding processes worsen the solid particle erosion resistance of 30 L steel at flow impact angles of 30° and 90°. All the considered variants of surface nitriding at an impact angle of 90° do not worsen the solid particle erosion resistance of 30 L steel samples, while at an impact angle of 30°, they increase the solid particle erosion resistance by at least 10–20%.

PHSPP06 Presentation Time: 3:20 PM: A New Way to Visualize Needles for Ultrasound Prostate Brachytherapy Using Color Doppler and Needle Surface Modifications

<h3>Purpose</h3> Brachytherapy applicator conspicuity during ultrasound (US) imaging can be impaired by bowel gas, tissue interfaces, or when the applicator is far or angled with respect to the ultrasound probe. Without adequate conspicuity, applicators can be inaccurately reconstructed, leading to decreased tumor control or increased normal tissue dose due to a geometrically inaccurate treatment plan. To improve the conspicuity of titanium high-dose rate (HDR) brachytherapy needles under US imaging, the surface of needles can be modified, and color-Doppler can be utilized to highlight the surface patterns. Color-Doppler imaging can produce a twinkling signature, also referred to as a ‘twinkling artifact,' when ultrasound waves reflect from a surface with a rough or patterned structure. The twinkling signature highlights the modified applicator as variegated pixels atop a grayscale B-mode US image, enhancing conspicuity. This research was a preliminary investigation into the types of surface modifications that can produce a twinkling signature, based upon a review of prior literature that has associated surface roughness with twinkling. <h3>Materials and Methods</h3> The surfaces of 17-gauge, 25 cm titanium HDR brachytherapy needles were modified using three methods of surface modification: sandblasting with an 80-grit media, laser-etching of thin grooves, and application of a polymethyl methacrylate (PMMA)-based bone cement. Laser-etches were created on the surface of the needles using a 343 nm femtosecond laser (Pharos, Light Conversion, Lithuania) on a machining system (Photomachining Inc., USA) and were created at variable widths (0.1-1 mm) and depths (10-100 μm) without penetrating the inner lumen of the applicator. Unmodified and modified needles were imaged with a bk3000 (BK Medical, USA) with an E14CL4b transrectal probe and Logiq E9 (General Electric, USA) with a 9L linear-array transducer under B-mode and color-Doppler imaging. Needle conspicuity between needle types was assessed qualitatively in the axial and sagittal planes within a prostate phantom (CIRS, Inc., USA). <h3>Results</h3> Color-Doppler imaging in combination with surface-modified needles produced a twinkling signature with select laser-etched and PMMA-cement surface modifications. The twinkling signature appeared as a color signal atop the applicator, overlaid on grayscale B-mode ultrasound images. The twinkling signature was observed with both transrectal and linear-array ultrasound transducers. Twinkling was observed at laser-etched scribe depths >20 μm and widths >0.1 mm, and it was observed that the magnitude of the twinkling signature was dependent upon the total surface area of the etched region. It was also demonstrated that needles can be laser-etched or coated with PMMA-cement to mark a reference location with respect to the needle tip (2 cm distal). The hand-roughened needles produced a faint twinkling signature with the linear-array transducer and negligible twinkling with the transrectal transducer. Sandblasted and unmodified needles produced a negligible twinkling signature. Generally, the twinkling signature was observed to be transient in nature and dependent on the pressure between the probe and the phantom. Future work is planned to study the mechanisms underlying the color-Doppler signal and to establish an optimal surface modification and signal strength. <h3>Conclusions</h3> Color-Doppler ultrasound combined with brachytherapy applicator surface modifications may be used to enhance applicator conspicuity and aid with applicator placement and digitization. HDR brachytherapy needles may be modified for color-Doppler imaging via laser-etching or coating with a PMMA-based bone cement.

Effect of microtopography on osseointegration of implantable biomaterials and its modification strategies.

Orthopedic implants are widely used for the treatment of bone defects caused by injury, infection, tumor and congenital diseases. However, poor osseointegration and implant failures still occur frequently due to the lack of direct contact between the implant and the bone. In order to improve the biointegration of implants with the host bone, surface modification is of particular interest and requirement in the development of implant materials. Implant surfaces that mimic the inherent surface roughness and hydrophilicity of native bone have been shown to provide osteogenic cells with topographic cues to promote tissue regeneration and new bone formation. A growing number of studies have shown that cell attachment, proliferation and differentiation are sensitive to these implant surface microtopography. This review is to provide a summary of the latest science of surface modified bone implants, focusing on how surface microtopography modulates osteoblast differentiation in vitro and osseointegration in vivo, signaling pathways in the process and types of surface modifications. The aim is to systematically provide comprehensive reference information for better fabrication of orthopedic implants.

Analysis of Surface Microstructures Formed on Ir Substrate under Different Bias Conditions by Microwave Plasma Chemical Vapor Deposition

To understand the process window of bias‐enhanced nucleation of diamond, it is important to study surface modifications of Ir substrates that occur under different conditions. Herein, various microstructures formed on Ir substrates are reported. The first microstructure contains rectangular particles with a size of several hundred nanometers obtained at a relatively high pressure of 12.5 kPa and a high temperature of 880 °C; these particles consist of epitaxially grown Ir3Si species. The second microstructure includes particles oriented along the [110] direction; these particles, however, consist of etched Ir pillars with a height of 400 nm when the substrate temperature increases to 1110 °C. Both microstructures form because of Ir sputtering due to the bombardment of energetic charged ions and the transport of Ir surface atoms. This study demonstrates two types of surface modifications under different bias‐enhanced nucleation conditions and provides a method for preparing an epitaxial Ir–Si compound that can be applied in various silicon‐based electronic devices.

Surface engineering of carbon fibre/epoxy composites with woven steel mesh for adhesion strength enhancement

Effects of surface modifications on the adhesive joint of carbon fibre reinforced polymer (CFRP) were investigated. CFRP surfaces were treated with traditional methods, such as acetone cleaning, sanding, grit blasting and peel ply. As a novel type of surface modification, stainless steel 316 wire mesh was co-cured on the CFRP laminate during the manufacturing stage. The surface topography of CFRP adherends was analysed through microscopic imaging. Surface roughness values were measured using a surface roughness tester. Contact angle measurements of probe liquids were performed to calculate surface energy. All adherends were bonded with a low viscosity epoxy adhesive. The single lap shear tests were used to measure the bonding strength of the CFRP joints. The experimental results showed that the highest average shear strength (24.2 MPa) was achieved for metal mesh modified joints. This amounted to a 101.7% increase compared with acetone-cleaned specimens. There was no statistically significant difference in shear strength among joints subjected to traditional surface treatments. Fracture surface images were analysed and correlation between surface treatment and lap shear strength was critically discussed.

Hemocompatibility And Cytotoxicity Of Small-Diameter Bioabsorbable Tissue-Engineered Vascular Grafts Depending On Anti-Thrombogenic And Antimicrobial Coating

Anti-thrombogenic and antimicrobial coatings of polymer grafts constitute a promising approach to preventing infection and thrombosis of vascular grafts. The objective was to study the hemocompatibility and cytotoxicity of PHBV/PCL grafts with iloprost and amphiphilic coating. Material and Methods — Polymer matrices were manufactured by electrospinning a mixture of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL) polymers. Several matrices were modified by complexation between polyvinylpyrrolidone (PVP) and cationic amphiphile and/or iloprost. The amphiphile was covalently cross-linked to the surface of other PHBV/PCL matrices. Unmodified PHBV/PCL matrices were used as the control group. Hemocompatibility and cytotoxicity of scaffolds before and after the modification were evaluated. Results — The hemocompatibility assessment revealed that hemolysis degree did not exceed normal values in all types of matrices. The PHBV/PCL/PVP matrices had increased platelet aggregation on the surface of the grafts. Subsequent addition of iloprost and amphiphile resulted in a sevenfold reduction of platelet aggregation. In PHBV/PCL/PVP matrices, the degree of platelet adhesion increased without changing the platelet deformation index values. Iloprost and amphiphilic coating of PHBV/PCL/PVP matrices diminished the number of adhered platelets and platelet deformation index by 1.5 times. The amphiphile, covalently cross-linked to PHBV/PCL matrices, caused a negative effect on the platelet adhesion, aggregation, and deformation index values. Evaluation of cytotoxicity of PHBV/PCL/PVP matrices, coated with iloprost and/or cationic amphiphile, demonstrated a slight decline in the rates of cell growth and proliferation after three days. Moreover, after three days, cell deaths and a sharp drop in the cell index values were noted in PHBV/PCL matrices with covalently cross-linked amphiphile. Conclusion — Iloprost and amphiphilic coating of PHBV/PCL grafts has increased their hemocompatibility. Also, there were no signs of cytotoxicity while using the complexation technique. However, covalently cross-linked amphiphile caused an increase in the cytotoxicity of matrices, which may have been indicative of the negative effect observed in this type of surface modification.

Experimental and Finite Element Studies on Free Vibration of Areca Leaf Sheath Reinforced Polymer Composites

The present work deals with the experimental and finite element free vibration studies on areca leaf sheath reinforced polymer composites. In this study fundamental frequencies are obtained for five boundary conditions numerically (such as CFFF, CFCF, SSSS, CSCS and CCCC) and only for 2 boundary conditions (CFFF and CFCF) experimentally. The natural frequencies were determined using the CQUAD8 finite element of MSC/NASTRAN and comparison made between the experimental values and the finite element solution. The effects of age of areca palm, number of layers, type of surface modification and boundary conditions on the natural frequencies of composites were studied. The experimental values of the first, second and third natural frequencies are in good agreement with those of the finite element solution in the case of areca leaf sheath reinforced composites under CFFF and CFCF boundary conditions. The natural frequency values found increases with an increase in the number of layers, age of areca palm and alkali percentage from 5 to 15% [46, 47]. Among different boundary conditions considered, composites with the CCCC boundary condition have exhibited higher values of natural frequencies as compared to other boundary conditions under finite element solutions.

Effect of surface modifications of additively manufactured Ti-6Al-4V alloys on apatite formation ability for biomedical applications

In this study, Ti-6Al-4V alloys were additively manufactured (AM) with different laser powers. The goal was to investigate the effect of different surface modifications on apatite formation ability. Four types of surface modifications, namely, sandblasting (S), acid etching (E), anodic oxidation (AO) and anodic spark oxidation (ASO), were achieved on the Ti-6Al-4V samples. The microstructure, phase, morphology, roughness and wettability properties were examined by optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), surface profilometer and contact angle techniques. The bioactivity analysis was performed in simulated body fluid (SBF) for 2 weeks. The results indicated that the microstructure, surface topography, roughness and wettability influenced the apatite formation were affected by the production laser power. Generally, the samples 3 showed higher Ca and P ion ratio value because of percentage of β phase amount, the presence of bioactive phases on the surfaces. The E3 sample resulted in the best apatite formation theoretically. The etching procedure of AM Ti-6Al-4V in the acidic solution can be applied to improve the apatite formation ability of Ti-6Al-4V alloys.

The effects of surface topography modification on hydrogel properties.

Hydrogel has been an attractive biomaterial for tissue engineering, drug delivery, wound healing, and contact lens materials, due to its outstanding properties, including high water content, transparency, biocompatibility, tissue mechanical matching, and low toxicity. As hydrogel commonly possesses high surface hydrophilicity, chemical modifications have been applied to achieve the optimal surface properties to improve the performance of hydrogels for specific applications. Ideally, the effects of surface modifications would be stable, and the modification would not affect the inherent hydrogel properties. In recent years, a new type of surface modification has been discovered to be able to alter hydrogel properties by physically patterning the hydrogel surfaces with topographies. Such physical patterning methods can also affect hydrogel surface chemical properties, such as protein adsorption, microbial adhesion, and cell response. This review will first summarize the works on developing hydrogel surface patterning methods. The influence of surface topography on interfacial energy and the subsequent effects on protein adsorption, microbial, and cell interactions with patterned hydrogel, with specific examples in biomedical applications, will be discussed. Finally, current problems and future challenges on topographical modification of hydrogels will also be discussed.

A critical review on surface modifications mitigating dairy fouling.

Thermal treatments performed in food processing industries generate fouling. This fouling deposit impairs heat transfer mechanism by creating a thermal resistance, thus leading to regular shutdown of the processes. Therefore, periodic and harsh cleaning-in-place (CIP) procedures are implemented. This CIP involves the use of chemicals and high amounts of water, thus increasing environmental burden. It has been estimated that 80% of production costs are owed to dairy fouling deposit. Since the 1970s, different types of surface modifications have been performed either to prevent fouling deposition (anti-fouling) or to facilitate removal (fouling-release). This review points out the impacts of surface modification on type A dairy fouling and on cleaning behaviors under batch and continuous flow conditions. Both types of anti-fouling and fouling-release coatings are reported as well as the different techniques used to modify stainless steel surface. Finally, methods for testing and characterising the effectiveness of coatings in mitigating dairy fouling are discussed.

Microtensile Bond Strength Between Resin-Matrix CAD/CAM Ceramics and Resin Cement after Various Surface Modifications and Artificial Aging.

To evaluate the effect of different surface modification methods on the microtensile bond strength (μTBS) of four resin-matrix CAD/CAM ceramics after artificial aging. Specimens of four CAD/CAM materials (Shofu Block HC, Lava Ultimate, Brilliant Crios, and Vita Enamic) were prepared and divided into four groups. Each group received one of the following treatments: group 1 (INT): no surface modification; group 2: sandblasting with 29-μm Al2O3 particles (SB); group 3: hydrofluoric acid etching (9%) + silane (HF+Si); group 4: sandblasting with 30-μm particles of the CoJet system (CJ). The specimens of each group were luted together in pairs using resin cement (RelyX Ultimate). After one week of water storage (37°C), the sandwich specimens were sectioned into rectangular microspecimens and half of them were immediately subjected to μTBS testing, while the other half was tested after six months. Data were statistically analyzed using FFANOVA including the factors of material, treatment, and storage time, with α = 0.05. After one week, the lowest μTBS was observed for INT, while the highest was found for either mechanical (SB and CJ) or chemical (HF+Si) treatments (p < 0.05). After six months, a significant decrease in μTBS was observed depending on treatment (p < 0.05), while artificial aging significantly influenced the μTBS of all experimental groups (p < 0.05). During the two storage periods, the failure type was mainly interfacial and was associated with the type of surface modification. After artificial aging, the μTBS appeared to depend on srface modification, while the parameter "material" did not influence the results. Consequently, adhesive strategies should be oriented towards surface modification techniques.

Potential Uses of Musaceae Wastes: Case of Application in the Development of Bio-Based Composites.

The Musaceae family has significant potential as a source of lignocellulosic fibres and starch from the plant’s bunches and pseudostems. These materials, which have traditionally been considered waste, can be used to produce fully bio-based composites to replace petroleum-derived synthetic plastics in some sectors such as packaging, the automotive industry, and implants. The fibres extracted from Musaceae have mechanical, thermal, and physicochemical properties that allow them to compete with other natural fibres such as sisal, henequen, fique, and jute, among others, which are currently used in the preparation of bio-based composites. Despite the potential use of Musaceae residues, there are currently not many records related to bio-based composites’ developments using starches, flours, and lignocellulosic fibres from banana and plantain pseudostems. In this sense, the present study focusses on the description of the Musaceae components and the review of experimental reports where both lignocellulosic fibre from banana pseudostem and flour and starch are used with different biodegradable and non-biodegradable matrices, specifying the types of surface modification, the processing techniques used, and the applications achieved.

A New Method of Bio-Catalytic Surface Modification for Microbial Desalination Cell

A microbial desalination cell (MDC) built on a modified surface has been studied for seawater desalination. The goal of this study is to provide and develop a seawater desalination system that does not require energy support by applying a modification of the anode as an electron acceptor. The different potential charges that occur between anode and cathode can serve as the driving force for electrodialysis of seawater, resulting in its desalination. Yeast has been applied as a biocatalyst and neutral red has been chosen as a redox mediator to facilitate the electron transport originating from the bioactivity of cells. Several types of surface modification have been conducted, i.e., biocatalyst-mediator immobilisation and electropolymerisation of neutral red at the anode surface. The optimisation of each device has been characterised by cyclic voltammetry and chronoamperometry. It has also been observed in a microbial fuel cell (MFC), prior to being functioned in the MDC. The concentrations of salt ion migration have been determined by ion exchange chromatography. This study found that the best configuration of a modified surface was obtained from carbon felt coated by polyneutral red film (CF/PNR); this generated the maximum value of all tested parameters: 42.2% of current efficiency; 27.11% of bio-devices efficiency; 92.5 mA m-2 of current density; and 61% of NaCl transport. Moreover, the modified surface could be a promising method for improving anode performance.

A Molecular Dynamics Study of Heat Transfer Enhancement during Phase Change from a Nanoengineered Solid Surface

This study investigates the enhancement of the rate of evaporation from a nanoengineered solid surface using non-equilibrium molecular dynamics simulation. Four different types of surface modifications were introduced to examine the thermal transportation behavior. The surface modification includes: (1) transformation of surface wetting condition from hydrophobic to hydrophilic, (2) implementing nanostructures on the smooth surface, (3) cutting nano slots on the smooth surface and (4) introducing nano-level surface roughness. Evaporation behavior from the same effective surface area was also studied. The simulation domain consisted of three distinct zones: solid base wall made of copper, a few layers of liquid argon, and a vapor zone made of argon. All the nano-level surface modifications were introduced on the solid base surface. The few layers of liquid argon representing the liquid zone of the domain take heat from the solid surface and get evaporated. Outside this solid and liquid zone, there is argon vapor. The simulation began at the initial time t = 0 ns and then was allowed to reach equilibrium. Immediately after equilibrium was achieved on all three-phase systems, the temperature of the solid wall was raised to a higher value. In this way, thermal transportation from the solid wall to liquid argon was established. As the temperature of the solid wall was high enough, the liquid argon tended to evaporate. From the simulation results, it is observed that during the transformation from hydrophobic to hydrophilic conditions, enhancement of evaporation takes place due to the improvement of thermal transportation behavior. At the nanostructure surface, the active nucleation sites and effective surface area increase which results in evaporation enhancement. With nano slots and nano-level surface roughness, the rate of evaporation increases due to the increase of solid-liquid contact area and effective surface area.

Active Carbon-Based Nanomaterials in Food Packaging

Carbon-based nanomaterials (CBN) are currently used in many biomedical applications. The research includes optimization of single grain size and conglomerates of pure detonated nanodiamond (DND), modified nanodiamond particles and graphene oxide (GO) in order to compare their bactericidal activity against food pathogens. Measurement of grain size and zeta potential was performed using the Dynamic Light Scattering (DLS) method. Surface morphology was evaluated using a Scanning Electron Microscope (SEM) and confocal microscope. X-ray diffraction (XRD) was performed in order to confirm the crystallographic structure of detonation nanodiamond particles. Bacteriostatic tests were performed by evaluating the inhibition zone of pathogens in the presence of carbon based nanomaterials. Raman spectroscopy showed differences between the content of the diamond and graphite phases in diamond nanoparticles. Fluorescence microscopy and adenosine-5′-triphosphate (ATP) determination methods were used to assess the bactericidal of bioactive polymers obtained by modification of food wrapping film using various carbon-based nanomaterials. The results indicate differences in the sizes of individual grains and conglomerates of carbon nanomaterials within the same carbon allotropes depending on surface modification. The bactericidal properties depend on the allotropic form of carbon and the type of surface modification. Depending on the grain size of carbon-based materials, surface modification, the content of the diamond and graphite phases, surface of carbon-based nanomaterials film formation shows more or less intense bactericidal properties and differentiated adhesion of bacterial biofilms to food films modified with carbon nanostructures.

A New Method of Bio-Catalytic Surface Modification For Microbial Desalination Cell

Microbial desalination cell (MDC) built on surface modification has been studied for seawater desalination. Herein, the bio-catalytic surface modification for maintenance the long-term MDC performance during desalination process has been developed. The goal of this study is to provide and develop a seawater desalination system without requiring energy support by applying a modification of anode as an electron acceptor, and the different potential charges that occur between anode and cathode can play as driving force for electrodialysis of seawater desalination. Yeast has been applied as biocatalyst, meanwhile neutral red has been chosen as redox mediator to facilitate the electron transport from bioactivity of cells. Several types of surface modification have been conducted, i.e. biocatalyst-mediator immobilization and electropolymerization of NR at the surface of the anode. The optimization of each device has been characterized by cyclic voltammetry, chronoamperometry, and observed in Microbial fuel cell (MFC) prior functioned in MDC. The concentrations of salt ion migration have been determined by Ion Exchange Chromatography. MFC results reported that the best configuration of surface modification was obtained from CF/PNR then applied in MDC. CF/PNR delivered the highly significant performance by having the maximum value of all tested parameters, i.e 42.2% of current efficiency; 27.11% of bio-devices efficiency; 92.5 mA m-2 of current density and also 61% of NaCl transport. The profiles of surface devices have been detected by Scanning electron microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX). A several spherical shapes around 4 nm within alginate layer have been detected from SEM images and it was confirmed as yeast, meanwhile 5.04% of N has been found from EDX spectrum and was indicated from PNR. The results show that surface modification could be a promising method for bioelectricity generation which simultaneously produces electricity and seawater desalination and provides a green chemistry technology.

One- pot development of spray dried cationic proliposomal dry powder insufflation: Optimization, characterization and bio-interactions

In the present investigation, one-pot synthesis method has been reported for the preparation of tramadol loaded proliposomes (PLs) coated with chitosan (CCPLs) and carboxymethyl chitosan (CM-ChPLs) for intranasal administration. Spray drying method used for formulation of PLs was optimized using Design of Experiment (DoE). The formulated PLs were extensively characterized and evaluated. The formulation was assessed for biocompatibility using cell viability assay, along with estimation of inflammatory potential of PLs,in vitro drug permeation across nasal mucosa,in vitro mucoadhesion study, nasal mucosa penetration study and analysis of powder spray pattern. The prepared PLs were also assessed for their interactions and stability under various physiological conditions. The interaction of different PLs with serum protein and mucin was assessed using DLS and zeta potential measurement. The stability study demonstrated superiority of coated PLs over uncoated PLs. The cell viability study confirmed the biocompatibility of developed PLs while confocal microscopy confirmed enhanced permeation of coated PLs across nasal mucosa. All PLs were stable in simulated nasal fluid. The in vitro drug release studies demonstrated sustained release which was also supported by results obtained after ex vivo permeation study. The overall results confirmed that type of surface modification and surface charge along with particle size plays an important role in type and extent of interaction of PLs with proteins and mucin. This could directly or indirectly affect the diffusion or penetration of nanoliposomes across mucosa and ultimately affects in vivo results.