Photo-triggerable liposomes based on lipid-porphyrin conjugate and cholesterol combination: Formulation and mechanistic study on monolayers and bilayers.

Lipid-porphyrin conjugates are considered nowadays as promising building blocks for the conception of drug delivery systems with multifunctional properties such as photothermal therapy (PTT), photodynamic therapy (PDT), phototriggerable release, photoacoustic and fluorescence imaging. For this aim, we have recently synthesized a new lipid-porphyrin conjugate named PhLSM. This was obtained by coupling pheophorbide-a (Pheo-a), a photosensitizer derived from chlorophyll-a, to egg lyso-sphingomyelin. The pure PhLSMs were able to self-assemble into vesicle-like structures that were however not stable and formed aggregates with undefined structures due to the mismatch between the length of the alkyl chain in sn-1 position and the adjacent porphyrin. Herein, stable PhLSMs lipid bilayers were achieved by mixing PhLSMs with cholesterol which exhibits a complementary packing parameter. The interfacial behavior as well as the fine structures of their equimolar mixture was studied at the air/buffer interface by the mean of Langmuir balance and x-ray reflectomerty (XRR) respectively. Our XRR analysis unraveled the monolayer thickening and the increase in the lateral ordering of PhLSM molecules. Interestingly, we could prepare stable vesicles with this mixture that encapsulate hydrophilic fluorescent probe. The light-triggered release kinetics and the photothermal conversion were studied. Moreover, the obtained vesicles were photo-triggerable and allowed the release of an encapsulated cargo in an ON-OFF fashion.

Ultraviolet-C inactivation and hydrophobicity of Bacillus subtilis and Bacillus velezensis spores isolated from extended shelf-life milk.

Bacterial spores are important in food processing due to their ubiquity, resistance to high temperature and chemical inactivation. This work aims to study the effect of ultraviolet C (UVC) on the spores of Bacillus subtilis and Bacillus velezensis at a molecular and individual level to guide in deciding on the right parameters that must be applied during the processing of liquid foods. The spores were treated with UVC using phosphate buffer saline (PBS) as a suspension medium and their lethality rate was determined for each sample. Purified spore samples of B. velezensis and B. subtilis were treated under one pass in a UVC reactor to inactivate the spores. The resistance pattern of the spores to UVC treatment was determined using dipicolinic acid (Ca-DPA) band of spectral analysis obtained from Raman spectroscopy. Flow cytometry analysis was also done to determine the effect of the UVC treatment on the spore samples at the molecular level. Samples were processed for SEM and the percentage spore surface hydrophobicity was also determined using the Microbial Adhesion to Hydrocarbon (MATH) assay to predict the adhesion strength to a stainless-steel surface. The result shows the maximum lethality rate to be 6.5 for B. subtilis strain SRCM103689 (B47) and highest percentage hydrophobicity was 54.9% from the sample B. velezensis strain LPL-K103 (B44). The difference in surface hydrophobicity for all isolates was statistically significant (P < 0.05). Flow cytometry analysis of UVC treated spore suspensions clarifies them further into sub-populations unaccounted for by plate counting on growth media. The Raman spectroscopy identified B4002 as the isolate possessing the highest concentration of Ca-DPA. The study justifies the critical role of Ca-DPA in spore resistance and the possible sub-populations after UVC treatment that may affect product shelf-life and safety. UVC shows a promising application in the inactivation of resistant spores though there is a need to understand the effects at the molecular level to design the best parameters during processing.

Impact of high-energy electron irradiation on mechanical, structural and chemical properties of agarose hydrogels.

Due to their excellent biocompatibility and biodegradability, natural hydrogels are highly demanded biomaterials for biomedical applications such as wound dressing, tissue engineering, drug delivery or three dimensional cell culture. Highly energetic electron irradiation up to 10 MeV is a powerful and fast tool to sterilize and tailor the material's properties. In this study, electron radiation treatment of agarose hydrogels was investigated to evaluate radiation effects on physical, structural and chemical properties. The viscoelastic behavior, surface hydrophilicity and swelling behavior in a range of typical sterilization doses of 0 kGy to 30 kGy was analyzed. The mechanical properties were determined by rheology measurements and decreased by more than 20% compared to the initial moduli. The number average molecular weight between crosslinks was estimated based on rubber elasticity theory to judge on the radiation degradation. In this dose range, the number average molecular weight between crosslinks increased by more than 6%. Chemical structure was investigated by FTIR spectroscopy to evaluate the radiation resistance of agarose hydrogels. With increasing electron dose, an increasing amount of carbonyl containing species was observed. In addition, irradiation was accompanied by formation of gas cavities in the hydrogels. The gas products were specified for CO2, CO and H2O. Based on the radiolytic products, a radiolysis mechanism was proposed. Electron beam treatment under high pressure conditions was found to reduce gas cavity formation in the hydrogels.

Use of gamma irradiation technology for modification of bacterial cellulose nanocrystals/chitosan nanocomposite film.

The objective of this work was to investigate the influence of different gamma ray dosages (5, 10, and 10 kGy) on the structural, mechanical, surface and barrier properties of chitosan (Ch) based nanocomposite film. The results showed gamma irradiation caused an increase in the surface hydrophobicity, water vapor permeability and sensitivity of films to water and also, yellowness and opacity of films increased, simultaneously. By increasing the irradiation doses up to 10 kGy, the mechanical properties of Ch/BCNC film was significantly enhanced. As observed by FTIR spectra, no change occurred in the chemical functional groups of the films during irradiation. XRD studies confirmed that crystallinity of films was increased after irradiation. The nanocomposite film irradiated by 10 kGy had the highest thermal stability. In conclusion, gamma radiation can be considered as a safe method for sterilization of foods and modification of Ch/BCNC film properties.

Ultraviolet irradiation improves the hydrophilicity and osteo-conduction of hydroxyapatite.

BACKGROUND: Treating a titanium or titanium alloy implant with ultraviolet (UV) light is known to improve its associated cell growth and osseointegration. However, little is known about the effect of UV irradiation on hydroxyapatite (HA), which is also used frequently in orthopaedic and dental surgery. Here we examined the effect of UV irradiation on the hydrophilicity of HA, and on its osteoconduction ability in rats. METHODS: HA implants of low and high porosity were treated with UV light, and photofunctionalisation was assessed by the contact angle of a water drop on the surface. HA implants were also inserted into rat femurs, and the rats were killed 2 or 4 weeks later. The bone volume and bone area ratio were calculated from microcomputed tomography and histological data. RESULTS: The contact angle of a water drop on HA implants of both porosities was significantly reduced after UV irradiation. In the rat femurs, there was no significant difference in the bone volume between the UV light-treated and control implants at 2 or 4 weeks. The bone area ratio for the UV light-treated versus control implants was significantly increased at 2 weeks, but there was no significant difference at 4 weeks. CONCLUSIONS: The surface of UV-irradiated HA disks was hydrophilic, in contrast to that of non-irradiated HA disks. Photofunctionalisation accelerated the increase in the bone area ratio in the early healing stage. This technology can be applied to surgical cases requiring the early fusion of bone and HA.

The cataract-related S39C variant increases γS-crystallin sensitivity to environmental stress by destroying the intermolecular disulfide cross-links.

γS-crystallin, a crucial structural lens protein, plays an important role in maintaining lens transparency through its solubility and stability. The S39C mutation, a proven pathogenic mutation involved in congenital cataract, resulted in progressive cataract in adolescents. In this study, using biophysical methods, we thoroughly investigated the effects of the S39C mutation on the γS-crystallin structure, stability and propensity for aggregations. The data from spectroscopy analyses did not reveal an effect of the S39C mutation on the native structure of monomeric γS-crystallin. However, when faced with oxidative conditions, the S39C mutation prevented γS-crystallin from forming stable disulfide-linked dimers and remarkably increased hydrophobicity and the propensity to aggregate and precipitate. Under UV irradiation, heat shock, and GdnHCl-induced denaturation, the S39C mutant tended to aggregate and was prone to form more deleterious aggregates than the wild type protein. Therefore, the S39C mutation significantly increased the sensitivity of γS-crystallin to environmental stress. However, the addition of αA-crystallin and lanosterol did not change the tendency of the mutant to aggregate. According to molecular dynamic (MD) simulations, the S39C mutation had little effect on the secondary or tertiary structures of monomeric γS-crystallin but disrupted the disulfide-linked structure of the γS-crystallin dimer. The cleavage of this bond might largely reduce the structural stability of γS-crystallin. The significant decrease in the structural stability along with the increasing aggregation tendency under environmental stress might be the major causes of progressive juvenile onset cataracts induced by the S39C mutation.

Effect of gamma sterilization on the properties of microneedle array transdermal patch system.

Soluble microneedles (MNs) of four different hydrophilic polymers namely sodium carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP) K30, PVP K90 and sodium hyaluronate (HU) were fabricated by mold casting technique. When exposed to gamma radiation, a dose of 25 kilogray (kGy) was found to render the microneedle (MN) sterile. However, CMC was found to form MNs with poor mechanical properties, whereas PVP K30 MNs were drastically deformed upon exposure to applied dose as observed in bright field microscopy. Scanning electron microscopy (SEM) revealed that morphology of PVP K90 and HU MNs were not significantly affected at the applied dose. The appearances of characteristic peaks of irradiated MNs of PVP K90 and HU in Fourier-transform infrared spectra suggested structural integrity of the polymers on irradiation. Differential scanning calorimetry (DSC) indicated gamma irradiation failed to alter the glass transition temperature and thus mechanical properties of PVP K90 MNs. However, DSC and Powder X-ray Diffraction (PXRD) conclusively indicated that the degree in crystallinity of HU was substantially reduced on irradiation. In vitro dissolution profiles of sterile PVP K90 and HU MNs were similar to un-irradiated MNs with a similarity factor (f2) of 64 and 54, respectively. In vivo dissolution studies in human subjects indicated that sterile MNs of PVP K90 and HU exhibited dissolution of 78.45 ± 1.09 and 78.57 ± 0.70%, respectively, after 20 min. The studies suggested that PVP K90 and HU could be suitable polymers to fabricate soluble MNs as the structural, morphological, microstructural and dissolution properties remained unaltered post γ sterilization.

Hydrophobic Tags for Highly Efficient Light-Activated Protein Release.

We have previously described the photoactivated depot (PAD) approach for the light-stimulated release of therapeutic proteins such as insulin. The aim of this method is to release insulin from a shallow dermal depot in response to blood glucose information, using transcutaneous irradiation. Our first approach utilized a photocleavable group that linked insulin to an insoluble but injectable polymer bead. The bead conferred insolubility, ensuring that the injected material stayed at the site of injection, until light cleaved the link, and allowed insulin to be absorbed systemically. While this proved to be effective, the use of a polymer to ensure insolubility introduces two major design problems: (1) low concentration of insulin, as a majority of the material is composed of polymer, and (2) upon release of the insulin, the polymer has to be cleared from the system. To address these two problems, in this work, we have pursued "hydrophobic tags", photocleavable small nonpolar molecules that confer insolubility to the modified insulin prior to irradiation without the bulk or need for biodegradation required of polymers. We developed a combined solid- and solution-phase synthetic approach that allowed us to incorporate a range of small nonpolar moieties, including peptides, into the final depot materials. The resulting materials are >90% w/w insulin and have sharply decreased solubilities relative to unmodified insulin (≤1000 × lower). We demonstrated that they can be milled into low micron-sized particles that can be readily injected through a 31G needle. These suspensions can be prepared at an effective concentration of 20 mM insulin, a concentration at which 120 µL contains 7 days of insulin for a typical adult. Finally, upon photolysis, the insoluble particles release soluble, native insulin in a predictable fashion. These combined properties make these new modified insulins nearly ideal as candidates for PAD materials.

Physical relation and mechanism of ultrasonic bactericidal activity on pathogenic E. coli with WPI.

OBJECTIVE: This study aimed to investigate the physical relation and mechanism of bactericidal activity on pathogenic E. coli by ultrasonic field with whey protein isolate (WPI). METHODS: Ultrasound treatment was performed under the conditions of intensity at 65 W/cm2, pulse duty ratio at 0.5 for 0-15 min with WPI concentration ranged from 0 to 10%. Viscosity, granularity, surface hydrophobicity, free radical scavenging activity, and thermal denaturation were assessed by rotational viscometer, Malvern Mastersizer 2000 particle size analyzer, fluorescent probe ANS method, DPPH method, and differential scanning calorimetry, respectively. RESULTS: The thermal denaturation of WPI was not altered by ultrasound field, but the viscosity of WPI was increased upon 10 min treatment. Additionally, its ability to scavenge free radicals and hydrophobicity were increased. The result also showed that the bacteria viability was improved by WPI during ultrasound treatment. However, the WPI protection was decreased by the prolonged treatment. CONCLUSION: Ultrasound treatment resulted in the increasing of the viscosity, free radicals scavenging activity and hydrophobicity of WPI which led to reduced bactericidal activity on E. coil, while WPI protection was disintegrated by prolonged treatment.

Glycation of ovalbumin after high-intensity ultrasound pretreatment: effects on conformation, immunoglobulin (Ig)G/IgE binding ability and antioxidant activity.

BACKGROUND: Ovalbumin (OVA), a protein with excellent nutritional and processing properties, is the major allergen of hen egg white. High-intensity ultrasound treatment increases the immunoglobulin (Ig)G and IgE binding abilities by unfolding the conformational structure of OVA. This may allow a modification of the IgG and IgE binding of OVA by combining high-intensity ultrasound with other methods, such as glycation, thus representing a promising method for the improvement of protein properties. RESULTS: Glycation with mannose (M) after ultrasound pretreatment at 0-600 W significantly reduced the IgG and IgE binding abilities and dramatically enhanced the antioxidant activity of OVA-M conjugates, with the lowest values of IgG and IgE binding and highest values of antioxidant capacity observed at 600 W. Polyacrylamide gel electrophoresis showed that the molecular weight of OVA-M conjugates with ultrasound pretreatment increased more than non-pretreatment sample, implying that ultrasound pretreatment promoted glycation. The α-helix content and ultraviolet absorption of OVA were observably increased, whereas ß-sheet content, intrinsic fluorescence and surface hydrophobicity were notably decreased, indicating that the tertiary and secondary structures of OVA were markedly changed. CONCLUSION: High-intensity ultrasound pretreatment can be conducive to reducing the binding abilities of IgG and IgE and enhancing the antioxidant activity of OVA-M conjugates. Therefore, glycation combined with high-intensity ultrasound pretreatment might be a promising method for producing hypo-allergenic and high-antioxidant OVA products. © 2018 Society of Chemical Industry.

Epitaxy of the bound water phase on hydrophilic surfaces of biopolymers as key mechanism of microwave radiation effects on living objects.

The research investigates the mechanism of microwave radiation effects on biological characteristics and structural-dynamic parameters of a sensor bioluminescence system. The research objects are a sterile growth medium (fish meal hydrolisate) and a bacterial culture. It has been established that irradiation causes changes of the growth medium spectral properties within the range of 200-350nm. Changes take place in the intensity and character of luminescence, as well as in relaxation parameters of nuclear magnetic resonance, growth characteristics of the bacterial culture, its cellular morphology and surface topology. The research results enabled us to establish the mechanisms of primary molecular processes that occur when the bacterial culture is exposed to microwave radiation. Transformation of the dynamic-structural state of adsorbed water phases on biopolymer surfaces has been found to be the key factor in the mechanism of microwave effects on living and water-containing objects.

The effect of microwave on the interaction of flavour compounds with G-actin from grass carp (Catenopharyngodon idella).

BACKGROUND: In order to investigate the influence of non-thermal effects of microwaves on the flavour of fish and meat products, the G-actin of grass carp in ice baths was exposed to different microwave powers (0, 100, 300 or 500 W); the surface hydrophobicity, sulfhydryl contents, secondary structures and adsorption capacity of G-actin to ketones were determined. RESULTS: As microwave power increased from 0 to 300 W, the surface hydrophobicity, total and reactive sulfhydryls increased; α-helix, ß-sheet and random coil fractions turned into ß-turn fractions. As microwave power increased from 300 to 500 W, however, hydrophobicity and sulfhydryl contents decreased; ß-turn and random coil fractions turned into α-helix and ß-sheet fractions. The tendencies of adsorbed capacity of ketones were similar to hydrophobicity and sulfhydryl contents. CONCLUSION: The increased adsorbing of ketones could be attributed to the unfolding of secondary structures by revealing new binding sites, including thiol groups and hydrophobic binding sites. The decreased binding capacity was related to the refolding and aggregation of protein. The results suggested that microwave powers had obvious effects on the flavour retention and proteins structures in muscle foods. © 2017 Society of Chemical Industry.

Design, microfabrication, and characterization of a moulded PDMS/SU-8 inkjet dispenser for a Lab-on-a-Printer platform technology with disposable microfluidic chip.

In this paper, we present a disposable inkjet dispenser platform technology and demonstrate the Lab-on-a-Printer concept, an extension of the ubiquitous Lab-on-a-Chip concept, whereby microfluidic modules are directly integrated into the printhead. The concept is demonstrated here through the integration of an inkjet dispenser and a microfluidic mixer enabling control over droplet composition from a single nozzle in real-time during printing. The inkjet dispenser is based on a modular design platform that enables the low-cost microfluidic component and the more expensive actuation unit to be easily separated, allowing for the optional disposal of the former and reuse of the latter. To limit satellite droplet formation, a hydrophobic-coated and tapered micronozzle was microfabricated and integrated with the fluidics to realize the dispenser. The microfabricated devices generated droplets with diameters ranging from 150-220 µm, depending mainly on the orifice diameter, with printing rates up to 8000 droplets per second. The inkjet dispenser is capable of dispensing materials with a viscosity up to ∼19 mPa s. As a demonstration of the inkjet dispenser function and application, we have printed type I collagen seeded with human liver carcinoma cells (cell line HepG2), to form patterned biological structures.

Probing carbonyl-water hydrogen-bond interactions in thin polyoxazoline brushes.

Temperature-responsive oxazoline-based polymer brushes have gained increased attention as biocompatible surfaces. In aqueous environment, they can be tuned between hydrophilic and hydrophobic behavior triggered by a temperature stimulus. This transition is connected with changes in molecule-solvent interactions and results in a switching of the brushes between swollen and collapsed states. This work studies the temperature-dependent interactions between poly(2-oxazoline) brushes and water. In detail, thermoresponsive poly(2-cyclopropyl-2-oxazoline), nonresponsive hydrophilic poly(2-methyl-2-oxazoline), as well as a copolymer of the two were investigated with in situ infrared ellipsometry. Focus was put on interactions of the brushes' carbonyl groups with water molecules. Different polymer-water interactions could be observed and assigned to hydrogen bonding between C=O groups and water molecules. The switching behavior of the brushes in the range of 20-45 °C was identified by frequency shifts and intensity changes of the amide I band.

Enhancement of Chaperone Activity of Plant-Specific Thioredoxin through γ-Ray Mediated Conformational Change.

AtTDX, a thioredoxin-like plant-specific protein present in Arabidopsis is a thermo-stable and multi-functional enzyme. This enzyme is known to act as a thioredoxin and as a molecular chaperone depending upon its oligomeric status. The present study examines the effects of γ-irradiation on the structural and functional changes of AtTDX. Holdase chaperone activity of AtTDX was increased and reached a maximum at 10 kGy of γ-irradiation and declined subsequently in a dose-dependent manner, together with no effect on foldase chaperone activity. However, thioredoxin activity decreased gradually with increasing irradiation. Electrophoresis and size exclusion chromatography analysis showed that AtTDX had a tendency to form high molecular weight (HMW) complexes after γ-irradiation and γ-ray-induced HMW complexes were tightly associated with a holdase chaperone activity. The hydrophobicity of AtTDX increased with an increase in irradiation dose till 20 kGy and thereafter decreased further. Analysis of the secondary structures of AtTDX using far UV-circular dichroism spectra revealed that the irradiation remarkably increased the exposure of ß-sheets and random coils with a dramatic decrease in α-helices and turn elements in a dose-dependent manner. The data of the present study suggest that γ-irradiation may be a useful tool for increasing holdase chaperone activity without adversely affecting foldase chaperone activity of thioredoxin-like proteins.

Hierarchical periodic micro/nano-structures on nitinol and their influence on oriented endothelialization and anti-thrombosis.

The applications of hierarchical micro/nano-structures, which possess properties of two-scale roughness, have been studied in various fields. In this study, hierarchical periodic micro/nano-structures were fabricated on nitinol, an equiatomic Ni-Ti alloy, using a femtosecond laser for the surface modification of intravascular stents. By controlling the laser fluence, two types of surfaces were developed: periodic nano- and micro/nano-structures. Evaluation of water contact angles indicated that the nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. Endothelial cells aligned along the nano-structures on both surfaces, whereas platelets failed to adhere to the micro/nano-surface. Decorrelation between the responses of the two cell types and the results of water contact angle analysis were a result of the pinning effect. This is the first study to show the applicability of hierarchical periodic micro/nano-structures for surface modification of nitinol.

Modification of the cell adhesion and hydrophilic characteristics of poly(ether-ether-ketone) by 172-nm xenon excimer radiation.

BACKGROUND: Poly-ether-ether-ketone (PEEK) has biomechanical and chemical properties that are excellent for biomedical applications; however, PEEK adhesion to bone or chondral tissue proceeds slowly due to poor hydrophilicity and other surface characteristics. OBJECTIVE: We investigated the structural change, hydrophilicity, and cytocompatibility of a PEEK surface after 172-nm xenon excimer UV-irradiation. METHODS: The surface characteristics before and after irradiation were evaluated by contact angle and ATR-FTIR measurements. Mouse osteoblast-like cells (MC3T3-E1) were cultured on PEEK plates and collected after 6, 12 and 24 h for cell adhesion analysis by crystal violet staining (CVS) and scanning electron microscopy (SEM). RESULTS: UV-irradiation improved PEEK surface hydrophilicity, as indicated by a significant drop in water contact angle (p<0.05). Irradiated PEEK showed additional peaks around 3370 cm-1 and 1720 cm-1, highlighting the generation of hydroxyl and carbonyl groups. CVS and SEM revealed improved adhesion to the PEEK surface after UV-irradiation. CONCLUSION: Our results suggest that 172-nm UV-irradiated PEEK may be used in biomedical applications that require good cell adhesion.

Effect of ultraviolet photofunctionalisation on the cell attractiveness of zirconia implant materials.

Ultraviolet (UV) light treatment of implant surfaces has been demonstrated to enhance their bioactivity significantly. This study examined the effect of UV treatment of different zirconia surfaces on the response of primary human alveolar bone-derived osteoblasts (PhABO). Disks of two zirconia-based materials with two different surface topographies (smooth, roughened) were exposed to UV light. Qualitative and quantitative assessment of PhABO on zirconia surfaces, by means of immunofluorescence, scanning electron microscopy and DNA quantification at 4 and 24 h revealed a higher number of initially attached osteoblasts on UV-treated surfaces. Cell area and perimeter were significantly larger on all UV-treated surfaces (p<0.05). The proliferation activity was significantly higher on both roughened UV-treated surfaces than on untreated samples at day 3 of culture (p<0.05). The expression levels of collagen I, osteopontin and osteocalcin at day 14 and alkaline phosphatase activity at day 7 and 14 of culture period were similar among UV-treated and untreated surfaces. Alizarin-Red-Staining at day 21 demonstrated significantly more mineralised nodules on UV-treated samples than on untreated samples. Contact angle measurements and X-ray photoelectron spectroscopy showed that UV light transformed zirconia surfaces from hydrophobic to (super-) hydrophilic (p<0.05) and significantly reduced the atomic percentage of surface carbon. The results showed that UV light pre-treatment of zirconia surfaces changes their physicochemical properties and improves their attractiveness against PhABO, primarily demonstrated by an augmented cell attachment and spreading. This may result in faster healing and better bone-to-implant contact of zirconia implants in vivo following such a pre-treatment.

Effect of ultraviolet-mediated photofunctionalization for bone formation around medical titanium mesh.

PURPOSE: The new technology of photofunctionalization with ultraviolet (UV) light for titanium implants has earned considerable attention. We hypothesized that UV light treatment would enhance bone formation on titanium mesh. MATERIALS AND METHODS: We implemented in vitro and in vivo experiments to examine the effectiveness of UV treatment for bone formation on titanium mesh surfaces. Titanium mesh for medical use was prepared as samples, which were autoclaved and stored under dark ambient conditions for 4 weeks. UV treatment was performed for 12 minutes. Carbon contamination, hydrophilicity, and protein adhesion of the titanium mesh surface were examined in an in vitro model. Bone tissue formation around the titanium mesh was observed in a rat femur bone model. The Mann-Whitney U test was used to examine differences between the untreated and UV-treated groups. P values of < .05 were considered significant. RESULTS: UV-mediated photofunctionalization reduced carbon contamination rates on the untreated titanium mesh surfaces. The hydrophobic surface of the untreated titanium mesh became superhydrophilic after UV-mediated photofunctionalization (P < .01). The amount of protein adsorbed onto the titanium was 1.5 to 3 times greater on the photofunctionalized titanium mesh surfaces than on the untreated titanium mesh surfaces (P < .01). In the animal experiment, the newly formed bone on the UV-treated titanium mesh was approximately 2.5 times greater than that on the untreated mesh (P < .05). CONCLUSIONS: UV-mediated photofunctionalization is effective, as demonstrated by the enhanced bone tissue formation on the titanium mesh. Future studies will focus on bone augmentation using an UV-mediated photofunctionalized titanium implant and mesh.

Physicochemical properties of peanut protein isolate-glucomannan conjugates prepared by ultrasonic treatment.

Peanut protein isolate (PPI) was glycated with glucomannan through classical heating or ultrasound treatment in this work. The physicochemical properties of PPI-glucomannan conjugates prepared by ultrasound treatment were compared to those prepared by classical heating. Compared with classical heating, ultrasound treatment could accelerate the graft reaction between PPI and glucomannan and improve the concentration of available free amino groups of PPI. Solubility and emulsifying properties of the conjugates obtained by ultrasound treatment were both improved as compared to those obtained by classical heating and native PPI. Decreases of lysine and arginine contents during the graft reaction indicated that these two amino acid residues attended the covalent linkage between PPI and glucomannan. Structural feature analyses suggested that conjugates obtained by ultrasound treatment had less α-helix, more ß-structures and random coil, higher surface hydrophobicity and less compact tertiary structure as compared to those obtained by classical heating and native PPI.