Search

Zirconia is one of the most commonly used materials for abutments of dental implants, especially in the anterior region. Soft tissue integration to the zirconia abutment surface remains a challenge. Peri-implant soft tissue integration serves as a physiological barrier, attenuating pathogen penetration and preventing peri‑implant disease. The surface microstructure of zirconia has significant effects on the biological behaviors of human gingival fibroblasts (HGFs), but the effects under inflammatory conditions are still unclear. In this study, we established two micro-nano structures on zirconia surfaces using a femtosecond laser, including microgrooves with widths of 30 µm (G3) and 60 µm (G6) and depths of 5 µm, and nanoparticles inside the microgrooves. Polished surfaces were used as controls. HGFs were seeded onto the three groups of zirconia specimens and stimulated with lipopolysaccharide. The HGFs on micro-nano-structured zirconia surfaces exhibited lower inflammatory responses and higher cell adhesion, proliferation, and migration under inflammatory conditions compared with the polished surfaces. Additionally, the G3 group exhibited lower inflammatory responses and higher cell adhesion and migration than the G6 group. The micro-nano-structured zirconia surface exhibited decreased neutrophil infiltration and increased M2-type macrophage polarization in vivo. To explore the molecular mechanism, RNA sequencing and gene silencing were utilized, which revealed two critical target genes regulated by the G3 group. Overall, we proposed an innovative micro-nano-structured zirconia surface that reduced the in vitro and in vivo inflammatory responses and promoted HGF adhesion, migration, and proliferation under inflammatory conditions, in which TRAFD1 and NLRC5 were the underlying key genes. Zirconia is one of the most commonly used materials for abutments, especially in the anterior region. The surface microstructure of zirconia has significant effects on the biological behaviors of human gingival fibroblasts (HGFs), but few studies have investigated these effects under inflammatory conditions, and the mechanism remains unclear. In this study, we developed an innovative micro-nano-structured zirconia surface using a femtosecond laser, which reduces the in vitro and in vivo pro-inflammatory responses and promotes HGFs adhesion, migration, and proliferation under inflammatory conditions compared with the polished zirconia surface. The potential underlying mechanism was also investigated. This work has provided some theoretical basis for the micro-nano-structured zirconia surface in potentially reducing the inflammation and enhancing peri‑implant soft-tissue integration under inflammatory conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

Repair of functionally graded biological interfaces requires joining dissimilar materials such as hard bone to soft tendon/ligament, with re-injuries/re-tears expected to be minimized by incorporating biomimicking, stress-reducing features within grafts. At bone-tendon interfaces (entheses), stress can be reduced via angled insertion, geometric flaring, mechanical gradation, and interdigitation of tissues. Here, we incorporated enthesis attributes into 3D in silico and physical models of a unique suture anchor-tendon hybrid graft (SATHG) and investigated their effects on stress reduction via finite element analyses (FEA) studies. Over 20 different simulations altering SATHG angulation, flaring, mechanical gradation, and interdigitation identified an optimal design, which included 90° angulation, 25° flaring, and a compliant (ascending then descending) mechanical gradient in SATHG's bone-to-tendon-like transitional region. This design reduced peak stress concentration factor (SCF) by 43.6 % relative to an ascending-only mechanical gradient typically used in hard-to-soft tissue engineering. To verify FEA results, SATHG models were fabricated using a photocrosslinkable bone-tendon-like polyurethane (QHM polymer) for ex vivo tensile assessment. Tensile testing showed that ultimate load (132.9 N), displacement-at-failure (1.78 mm), stiffness (135.4 N/mm), and total work-to-failure (422.1 × 10−3 J) were highest in the optimized design. Furthermore, to assess envisioned usage, SATHG pull-out testing and 6-week in vivo implantation into large, 0.5-cm segmental supraspinatus tendon defects was performed. SATHG pull-out testing showed secure bone attachment while histological assessment such as hematoxylin and eosin (H&E) together with Safranin-O staining showed biocompatibility including enthesis regeneration. This work demonstrates that engineering biomaterials with FEA-optimized, enthesis-like attributes shows potential for enhancing hard-to-soft tissue repair. Successful repair of hard-to-soft tissue injuries is challenging due to high stress concentrations within bone-tendon/ligament grafts that mechanically compromise repair strength. While stress-reducing gradient biomaterials have been reported, little-to-no attention has focused on other bone-tendon/ligament interface (enthesis) features. To this end, a unique bone-tendon graft (SATHG) was developed by combining two common orthopaedic devices along with biomimetic incorporation of four enthesis-like features to reduce stress and encourage widespread clinician adoption. Notably, utilizing designs based on natural stress dissipation principles such as anchor insertion angle, geometric flaring, and mechanical gradation reduced stress by 43.6 % in silico , which was confirmed ex vivo , while in vivo studies showed SATHG's ability to support native enthesis regeneration. Thus, SATHG shows promise for hard-to-soft tissue repairs. [Display omitted] [ABSTRACT FROM AUTHOR]

Surface modification of implants in the nanoscale or implant nano-engineering has been recognized as a strategy for augmenting implant bioactivity and achieving long-term implant success. Characterizing and optimizing implant characteristics is crucial to achieving desirable effects post-implantation. Modified implant enables tailored, guided and accelerated tissue integration; however, our understanding is limited to multicellular (bulk) interactions. Finding the nanoscale forces experienced by a single cell on nano-engineered implants will aid in predicting implants' bioactivity and engineering the next generation of bioactive implants. Atomic force microscope (AFM) is a unique tool that enables surface characterization and understanding of the interactions between implant surface and biological tissues. The characterization of surface topography using AFM to gauge nano-engineered implants' characteristics (topographical, mechanical, chemical, electrical and magnetic) and bioactivity (adhesion of cells) is presented. A special focus of the review is to discuss the use of single-cell force spectroscopy (SCFS) employing AFM to investigate the minute forces involved with the adhesion of a single cell (resident tissue cell or bacterium) to the surface of nano-engineered implants. Finally, the research gaps and future perspectives relating to AFM-characterized current and emerging nano-engineered implants are discussed towards achieving desirable bioactivity performances. This review highlights the use of advanced AFM-based characterization of nano-engineered implant surfaces via profiling (investigating implant topography) or probing (using a single cell as a probe to study precise adhesive forces with the implant surface). Nano-engineering is emerging as a surface modification platform for implants to augment their bioactivity and achieve favourable treatment outcomes. In this extensive review, we closely examine the use of Atomic Force Microscopy (AFM) to characterize the properties of nano-engineered implant surfaces (topography, mechanical, chemical, electrical and magnetic). Next, we discuss Single-Cell Force Spectroscopy (SCFS) via AFM towards precise force quantification encompassing a single cell's interaction with the implant surface. This interdisciplinary review will appeal to researchers from the broader scientific community interested in implants and cell adhesion to implants and provide an improved understanding of the surface characterization of nano-engineered implants. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: We examined blood and protein dynamics potentially influenced by implant threads and hydrophilic/hydrophobic states of implant surfaces. Methods: A computational fluid dynamics model was created for a screw-shaped implant with a water contact angle of 70° (hydrophobic surface) and 0° (superhydrophilic surface). Movements and density of blood and fibrinogen as a representative wound healing protein were visualized and quantified during constant blood inflow. Results: Blood plasma did not occupy 40-50% of the implant interface or the inside of threads around hydrophobic implants, whereas such blood voids were nearly completely eliminated around superhydrophilic implants. Whole blood field vectors were disorganized and random within hydrophobic threads but formed vortex nodes surrounded by stable blood streams along the superhydrophilic implant surface. The averaged vector within threads was away from the implant surface for the hydrophobic implant and towards the implant surface for the superhydrophilic implant. Rapid and massive whole blood influx into the thread zone was only seen for the superhydrophilic implant, whereas a line of conflicting vectors formed at the entrance of the thread area of the hydrophobic implant to prevent blood influx. The fibrinogen density was up to 20-times greater at the superhydrophilic implant interface than the hydrophobic one. Fibrinogen density was higher at the interface than outside the threads only for the superhydrophilic implant. Conclusions: Implant threads and surface hydrophilicity have profound effects on vector and distribution of blood and proteins. Critically, implant threads formed significant biological voids at the interface that were negated by superhydrophilicity- induced contact hemodynamics. [ABSTRACT FROM AUTHOR]

• Preparation of new series of Gemini cationic surfactant. • Evaluating surface and thermodynamic parameters of the prepared amphiphiles. • The different analyses confirm the structure of the prepared amphiphiles. • The prepared amphiphiles were evaluated as antibacterial agents against both gram negative and positive bacteria and fugi. Three Gemini amphiphiles had prepared through reaction of amide of succinic acid with different bromo olefins. Their chemical structure was emphasized different spectroscopic methods. the surface tension measurements were investigated at 20, 40 and 60 °C. The Gemini surfactant with the longest tail clarified enhancement of surface parameters values with elevating mixture temperature. Both (ΔGo ads) & (ΔGo mic) data are negative, providing spontaneously occurrence of adsorption and micellization processes while the positivity of (ΔSo ads) &(ΔSo mic) revealing more order for both processes. Thermodynamic behaviour increases by raising chain length. All of fabricated amphiphiles exhibited antimicrobial activity against bacteria and fungi. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To evaluate the influence of brushing with a specific antiseptic soap solution on the surface (roughness and hardness) and biological properties of a specific hard chairside reline resin. Methods: The hard chairside reline resin specimens were made and distributed to the following groups according to disinfectant solution: sodium hypochlorite 0.5% (SH), Lifebuoy solution 0.78%; experimental group (LS) and phosphate-buffet-ed saline PBS to be submitted to the brushing cycle for 10 seconds. The roughness and hardness were assessed before and after the cycle. For the biological properties, the colony-forming unit and Alamar Blue assays were performed. For all the properties evaluated the sample size consisted of nine specimens. The data were submitted to two-factor ANOVA (surface properties) and oneway ANOVA (biological properties) and Tukey's post-test with a significance level of 5% (a= 0.05). Results: The Lifebuoy group did not present a statistical difference (P> 0.05) in relation to the other groups for the evaluated surface properties. Furthermore, the Lifebuoy solution showed a statistically significant difference (P> 0.05) in relation to the negative control in the reduction of biofilm on the resin and no significant difference (P> 0.05) was observed when compared to the positive control group. Thus, it was concluded that brushing with the Lifebuoy soap solution did not interfere with the surface properties of the hard chairside reline resin, and was able to reduce the biofilm of C albicans. [ABSTRACT FROM AUTHOR]

This study represents the baseline of estimation of the potential service provided by fishermen as "cleaners of the sea". The amount, composition and depth distribution of marine litter in fishing grounds of the Northern Adriatic seafloor has been investigated through the fishing for litter (FFL) scheme. Passive FFL campaigns were carried out by trawlers from two of the most important fishing ports in the northern Adriatic, Chioggia and Goro, from May 2020 to May 2021. Over the course of 256 days of fishing, over 6 tons of litter were removed from 265 km2 of seafloor. Abandoned, lost and derelict fishing gears (ALDFG) were the most represented litter category (48 % of the total litter), and of these 67 % were plastic ALDFG (mostly mussel socks and fishing nets). Fouling on plastic waste was analyzed to determine the fraction of collected litter items that could be destinated to recycling. Only a small percentage of the plastic litter analyzed was "clean" from adherent and/or encrusting organisms. Approximately 2.4 tons of plastic were recovered, but, due to the biological colonization of surfaces, they cannot be recycled by using the technologies present in the area. • Benthic litter in Adriatic fishing grounds was collected through FFL schemes. • The 20–30 m depth interval was the most polluted by marine waste. • In 256 days of fishing over 6 tons of litter were recovered, half of which were plastic ALDFG. • The majority of plastic litter was affected by biological fouling making it difficult to recycle. [ABSTRACT FROM AUTHOR]

Cold plasma (CP) has an inactivating effect on bacteria, but little research has been done on fungi, especially on aflatoxin (AF)-producing strains of Aspergillus flavus (A. flavus). In this study, a CP device was utilized to investigate the destructive effects and mechanisms of different voltage treatments on AF-producing A. flavus strains. The inactivation curve was fitted using Weibull and Logistics kinetic models (R 2 > 0.930). The results of viable spore count and AF detection showed that after 6 min of 60 V treatment, the total number of viable spores decreased by 4.47 log 10 CFU/mL, and the AF level was found to be significantly lower after treatment (p < 0.05). The microstructure of A. flavus spores was severely damaged after DBDP treatment. The leakage of nucleic acids and proteins, lipid oxidation level, reactive oxygen level, and Fourier transform infrared spectroscopy analysis of spores all confirmed that the cell membrane of A. flavus was damaged after DBDP treatment. This study could provide reference methods for CP technology in the control of AF-producing A. flavus. • Inactivation of Aspergillus flavus spores by cold plasma was significant. • Cold plasma effectively inhibited the ability of Aspergillus flavus to produce AFB 1 , AFB 2 and AFG 1. • The disruption of cell membrane integrity of Aspergillus flavus was observed after cold plasma treatment. • Cold plasma induced the change of biological macromolecules on the surface of Aspergillus flavus spores. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the influence of brushing with specific antiseptic soap solution on the surface (roughness, hardness, and color stability) and biological properties of a specific heat-polymerized denture base resin. Methods: 189 denture base acrylic resin specimens (10 mm x 1.2 mm) were made and distributed into three groups: sodium hypochlorite 0.5% (SH), Lifebuoy solution 0.78% (LS) and phosphate-buffered saline (PBS) and were submitted to the brushing cycle for 10 seconds. For each property assessed the sample size was composed of nine specimens. Roughness, hardness, and color stability were assessed before and after the cycle. For the biological properties (biofilm formation and reduction capacity) the colony forming unit and Alamar Blue assays were performed. For this, the specimens were placed separately in a 24-well plate with medium containing C. albicans. The plate was incubated for 48 hours for the formation of mature biofilm. The data were submitted to two-factor ANOVA (roughness and hardness) and one-way ANOVA (color stability and biological properties) and Tukey's post-test (a= 0.05). Results: The Lifebuoy group did not present a statistical difference (P> 0.05) in relation to the other groups for the evaluated surface properties (roughness, hardness, and color stability). Also, from the colony-formation unit and Alamar Blue assays, there was no statistical difference (P> 0.05) between the groups. Regarding biofilm reduction capacity formed on the samples, the results obtained from the count of colony forming units (CFU/mL) showed a reduction of approximately 1.3 logs in the number of CFU/mL in the Lifebuoy group (p = 4.78 log10) compared to the negative control group (p = 6.02 log10) (P< 0.05). When evaluating the cellular metabolism of C. albicans cells, the experimental group did not show any statistical difference compared to controls (P> 0.05). Brushing with Lifebuoy soap solution did not alter the surface properties of the acrylic resin, and reduced the C. albicans biofilm. [ABSTRACT FROM AUTHOR]

Zwitterionic polymers have shown promising results in non-fouling and preventing thrombosis. However, the lack of controlled surface coverage hinders their application for biomedical devices. Inspired by the natural biological surfaces, a facile zwitterionic microgel-based coating strategy is developed by the co-deposition of poly (sulfobetaine methacrylate-co-2-aminoethyl methacrylate) microgel (SAM), polydopamine (PDA), and sulfobetaine-modified polyethyleneimine (PES). The SAMs were used to construct controllable morphology by using the PDA combined with PES (PDAS) as the intermediate layer, which can be easily modulated via adjusting the crosslinking degree and contents of SAMs. The obtained SAM/PDAS coatings exhibit high anti-protein adhesive properties and can effectively inhibit the adhesion of cells, bacteria, and platelet through the synergy of high deposition density and controllable morphology. In addition, the stability of SAM/PDAS coating is improved owing to the anchoring effects of PDAS to substrate and SAMs. Importantly, the ex vivo blood circulation test in rabbits suggests that the SAM/PDAS coating can effectively decrease thrombosis without anticoagulants. This study provides a versatile coating method to address the integration of zwitterionic microgel-based coatings with high deposition density and controllable morphology onto various substrates for wide biomedical device applications. Thrombosis is a major cause of medical device implantation failure, which results in significant morbidity and mortality. In this study, inspired by natural biological surfaces (fish skin and vascular endothelial layer) and the anchoring ability of mussels, we report a convenient and efficient method to firmly anchor zwitterionic microgels using an oxidative co-deposition strategy. The prepared coating has excellent antifouling and antithrombotic properties through the synergistic effect of physical morphology and chemical composition. This biomimetic surface engineering strategy is expected to provide new insights into the clinical problems of blood-contacting devices related to thrombosis. [Display omitted] [ABSTRACT FROM AUTHOR]

The biological surface structure comprising fish scales and a mucous membrane exhibits good turbulent drag reduction ability. Based on this structure, a bionic frictional drag reduction model composed of a grooved structure and mucous membrane was established herein, and its efficacy in reducing the resistance of a turbulent boundary layer was analyzed. Accordingly, the drag reduction performance of the bionic structure was investigated through large eddy simulations. The results revealed that the mucous membrane was evenly distributed on the groove wall through secretion, and effectively improved the drag reduction rate of the groove wall. The bionic grooves and mucous membrane structure successfully inhibited the turbulent kinetic energy, turbulence intensity, and Reynolds stress. The grooved structure improved the shape of the Λ vortex structure and the mucous membrane reduced the number of three-dimensional (3D) vortex structures. Furthermore, the streak structure near the bionic structure wall was reduced and its shape was regularized, which intuitively demonstrates the turbulence suppression ability of the proposed bionic structure. This paper presents the results of a hydrodynamic analysis of the frictional drag reduction characteristics of a bionic structure consisting of grooves and viscous membranes acting on the turbulent boundary layer of a wall. [ABSTRACT FROM AUTHOR]

Recent knowledge about biological joint morphogenesis opens new perspectives in mechanics to automate joint contact surface design. The present work evaluates the feasibility of a generative design method inspired by the joint morphogenesis process to develop contact surfaces. A finite element model of joint morphogenesis reported in literature was implemented. This morphogenesis process was adapted and implemented for mechanical applications. The results show that the bioinspired joint shaping process adds matter in the zones next to the contact zone decreasing the contact pressure (up to 57%). The results demonstrate the feasibility of implementing biological growing rules in generative design. [ABSTRACT FROM AUTHOR]

Although an established drug delivery platform, liposomes have not fulfilled their true potential. In the body, interactions of liposomes are mediated by the layer of plasma proteins adsorbed on the surface, the protein corona. The review aims to collect the data of the last decade on liposome protein corona, tracing the path from interactions of individual proteins to the effects mediated by the protein corona in vivo. It offers a classification of the approaches to exploitation of the protein corona—rather than elimination thereof—based on the bilayer composition–corona composition–molecular interactions–biological performance framework. The multitude of factors that affect each level of this relationship urge to the widest implementation of bioinformatics tools to predict the most effective liposome compositions relying on the data on protein corona. Supplementing the picture with new pieces of accurately reported experimental data will contribute to the accuracy and efficiency of the predictions. The review focuses on liposomes as an established nanomedicine platform and analyzes the available data on how the protein corona formed on liposome surface in biological fluids affects performance of the liposomes. The review offers a rigorous account of existing literature and critical analysis of methodology currently applied to the assessment of liposome–plasma protein interactions. It introduces a classification of the approaches to exploitation of the protein corona and tailoring liposome carriers to advance the field of nanoparticulate drug delivery systems for the benefit of patients. [Display omitted] [ABSTRACT FROM AUTHOR]

This case study examines researchers' experiences with -- and several media's practices of -- communicating a research project that is scientifically complex, potentially highly impactful and socially contestable: the NTNU Cyborg. The project's researchers study human cells as components connected to a robot interfaced with biological neural networks. Key goals of our study are to understand challenges tied to communicating interdisciplinary research that tends to be regarded as pushing ethical barriers, and to contribute to critical reflection on how communication practices and media coverage may strengthen a dialogue between citizens and research communities on social issues tied to science-in-the-making. [ABSTRACT FROM AUTHOR]

Stem cells have great potential in the field of tissue engineering and regenerative medicine due to their inherent regenerative capabilities. However, an ongoing challenge within their clinical translation is to elicit or predict the desired stem cell behavior once transplanted. Stem cell behavior and function are regulated by their interaction with biophysical and biochemical signals present in their natural environment (i.e., stem cell niches). To increase our understanding about the interplay between stem cells and their resident microenvironments, biointerfaces have been developed as tools to study how these substrates can affect stem cell behaviors. This article aims to review recent developments on fabricating cell-instructive interfaces to control cell adhesion processes towards directing stem cell behavior. After an introduction on stem cells and their natural environment, static surfaces exhibiting predefined biochemical signals to probe the effect of chemical features on stem cell behaviors are discussed. In the third section, we discuss more complex dynamic platforms able to display biochemical cues with spatiotemporal control using on-off ligand display, reversible ligand display, and ligand mobility. In the last part of the review, we provide the reader with an outlook on future designs of biointerfaces. Stem cells have great potential as treatments for many degenerative disorders prevalent in our aging societies. However, an ongoing challenge within their clinical translation is to promote stem cell mediated regeneration once they are transplanted in the body. Stem cells reside within our bodies where their behavior and function are regulated by interactions with their natural environment called the stem cell niche. To increase our understanding about the interplay between stem cells and their niche, 2D materials have been developed as tools to study how specific signals can affect stem cell behaviors. This article aims to review recent developments on fabricating cell-instructive interfaces to control cell adhesion processes towards directing stem cell behavior. Stem cell adhesion to ECM components and ECM-inspired biointerfaces. [Display omitted] [ABSTRACT FROM AUTHOR]

This study aimed to assess the mechanical and biological properties of bioactive glass (BG) coating on titanium (Ti). Bioinert Ti substrates were coated by BG to induce bioactivity to the surface. The sol-gel derived BG 58S sol was successfully prepared and coated on the abraded and blasted Ti surface using the sol-dip method. The characterization and cell study for all substrates’ surface was carried out. Adhesion test confirmed that a firmly adhered BG coating layer was formed on the abraded and blasted Ti. The measured bonding strength between the coating and the blasted Ti substrate was the highest among all samples, which was 41.03±2.31 MPa. In-vitro cell viability and alkaline phosphatase activity (ALP) tests results also showed that BG coating on the Ti substrate improved the biological properties of the surface. The BG sol-dip coating method could be used to fabricate Ti substrate with a bioactive surface. [ABSTRACT FROM AUTHOR]

Bioactive surfaces modified with functional peptides are critical for both fundamental research and practical application of implant materials and tissue repair. However, when bioactive molecules are tethered on biomaterial surfaces, their functions can be compromised due to unwanted fouling (mainly nonspecific protein adsorption and cell adhesion). In recent years, researchers have continuously studied antifouling strategies to obtain low background noise and effectively present the function of bioactive molecules. In this review, we describe several commonly used antifouling strategies and analyzed their advantages and drawbacks. Among these strategies, antifouling molecules are widely used to construct the antifouling layer of various bioactive surfaces. Subsequently, we summarize various structures of antifouling molecules and their surface grafting methods and characteristics. Application of these functionalized surfaces in microarray, biosensors, and implants are also introduced. Finally, we discuss the primary challenges associated with antifouling layers in fabricating bioactive surfaces and provide prospects for the future development of this field. The nonspecific protein adsorption and cell adhesion will cause unwanted background "noise" on the surface of biological materials and detecting devices and compromise the performance of functional molecules and, therefore, impair the performance of materials and the sensitivity of devices. In addition, the selection of antifouling surfaces with proper chain length and high grafting density is also of great importance and requires further studies. Otherwise, the surface-tethered bioactive molecules may not function in their optimal status or even fail to display their functions. Based on these two critical issues, we summarize antifouling molecules with different structures, variable grafting methods, and diverse applications in biomaterials and biomedical devices reported in literature. Overall, we expect to shed some light on choosing the appropriate antifouling molecules in fabricating bioactive surfaces. [Display omitted] [ABSTRACT FROM AUTHOR]

Programmed cell death protein 1 (PD‐1), an immune checkpoint receptor expressed by activated T, B, and NK cells, is a well‐known target for cancer immunotherapy. Tislelizumab (BGB‐A317) is an anti‐PD‐1 antibody that has recently been approved for treatment of Hodgkin's lymphoma and urothelial carcinoma. Here, we show that tislelizumab displayed remarkable antitumor efficacy in a B16F10/GM‐CSF mouse model. Structural biology and Surface plasmon resonance (SPR) analyses revealed unique epitopes of tislelizumab, and demonstrated that the CC′ loop of PD‐1, a region considered to be essential for binding to PD‐1 ligand 1 (PD‐L1) but not reported as targeted by other therapeutic antibodies, significantly contributes to the binding of tislelizumab. The binding surface of tislelizumab on PD‐1 overlaps largely with that of the PD‐L1. SPR analysis revealed the extremely slow dissociation rate of tislelizumab from PD‐1. Both structural and functional analyses align with the observed ability of tislelizumab to completely block PD‐1/PD‐L1 interaction, broadening our understanding of the mechanism of action of anti‐PD‐1 antibodies. [ABSTRACT FROM AUTHOR]

In view of the fact that titanium (Ti)-based implants still face the problem of loosening and failure of the implants caused by the slow biological response, the low osseointegration rate and the implant bacterial infection in clinical application, we designed a cancellous bone-like biomimetic Ti scaffold using the template accumulated by sugar spheres as a pore-forming agent. And based on a modified surface mineralization process and mussel-like adhesion mechanism, a silicon-doped calcium phosphate composite coating (Van-pBNPs/pep@pSiCaP) with Vancomycin (Van)-loaded polydopamine (pDA)-modified albumin nanoparticles (Van-pBNPs) and cell adhesion peptides (GFOGER) was constructed on the surface of Ti scaffold for mimicking the extracellular matrix (ECM) microenvironment of natural bone matrix to induce greater tissue regeneration. The in vitro study demonstrated that this porous Ti scaffold with functional bio-surface could distinctly facilitate cell early adhesion and spreading, and activate the expression of α2β1 integrin receptor on the cell membrane through promoting the formation of focal adhesions (FAs) in bone marrow stromal cells (BMSCs), thus mediating greater osteogenic cell differentiation. And it could also effectively inhibit the adhesion and growth of Staphylococcus epidermidis, exhibiting good antibacterial properties. Moreover, the Van-pBNPs/pep@pSiCaP-Ti scaffolds showed enhanced in vivo bone-forming ability due to the contributions of bioactive chemical components and the natural cancellous bone-like macrostructure. This work offers a promising structural and functional bio-inspired strategy for designing metal implants with desirable ability of osteoinduction synergistically with antibacterial efficacy for promoting bone regeneration and infection prevention simultaneously. This manuscript describes a new method for making porous Ti scaffolds with a natural cancellous bone-like structure. Besides, a functional bio-surface was constructed on the bionic structure, mimicking some of the functions of the collagen-rich organic matrix and inorganic CaP nanocrystallites of native ECM of bone in chemical components and biological activities. This interconnected inter-pore opening structure encouraged the migration of cells among open macro-pores within the scaffold. In addition, the functionalized surface not only improved early cell adhesion, spreading, stimulated greater osteogenic differentiation of bone-forming cells, but also endowed the scaffold with excellent antibacterial effect. The biomimetic metal implant with multiple biomedical functions designed in this study has a great clinical application potential. This study represents a feasible method for the preparation of biomimetic structure of metal implants and the improvement of their surface biological activity. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Postoperative adhesions protect, repair, and supply nutrients to injured tissues; however, such adhesions often remain permanent and complicate otherwise successful surgeries by tethering tissues together that are normally separated. An ideal adhesion barrier should not only effectively prevent unwanted adhesions but should be easy to use, however, those that are currently available have inconsistent efficacy and are difficult to handle or to apply. A robust hydrogel film composed of alginate and a photo-crosslinkable hyaluronic acid (HA) derivative (glycidyl methacrylate functionalized hyaluronic acid (GMHA)) represents a solution to this problem. A sacrificial porogen (urea) was used in the film manufacture process to impart macropores that yield films that are more malleable and tougher than equivalent films produced without the sacrificial porogen. The robust mechanical behavior of these templated alginate/GMHA films directly facilitated handling characteristics of the barrier film. In a rat peritoneal abrasion model for adhesion formation, the polysaccharide films successfully prevented adhesions with statistical equivalence to the leading anti-adhesion technology on the market, Seprafilm®. Postoperative adhesions often remain permanent and complicate otherwise successful surgeries by tethering tissues together that are normally separated and pose potentially significant challenges to patients. Therefore, the generation of adhesion barriers that are easy to deploy during surgery and effectively prevent unwanted adhesions is a big challenge. In this study robust hydrogel films composed of alginate and a photo-crosslinkable hyaluronic acid (HA) derivative (glycidyl methacrylate functionalized HA, GMHA) were fabricated and investigated for their potential to act as a solution to this problem using a rat peritoneal abrasion model for adhesion formation. We observed the polysaccharide films successfully prevented adhesions with statistical equivalence to the leading anti-adhesion technology on the market, Seprafilm®, suggesting that such films represent a promising strategy for the prevention of postoperative adhesions. Image, graphical abstract [ABSTRACT FROM AUTHOR]

This paper reports a non-invasive method for in situ biofilm quantification based on the use of hyperspectral imaging to analyze a chromatically and texturally heterogeneous substrate as granite colonized by green algae and cyanobacteria. Biofilm-forming microorganisms were inoculated on granite blocks and incubated under laboratory conditions for 21 days. The intensity of the green stains formed on the granite surfaces differed depending on the initial concentration of microorganisms used. A biofilm quantification (BQ) index was computed to determine the level of colonization on the surfaces. The index was obtained by comparing the quotient of the reflectance of the green (G) and red (R) bands of each pixel of the hyperimage against a threshold value, fth. The optimal value of the threshold was determined by examining the linear correlation between the BQ index and the chlorophyll a extracted. The BQ results were then compared with the F0 and ΔE*ab parameters yielded by colour spectrophotometry and PAM fluorometry techniques and used as reference methodologies to quantify greening on stone surfaces. The BQ index showed a high level of consistency with all of the other parameters; it was linearly correlated with the chlorophyll a concentration, F0 andΔE*ab, with high coefficients of determination (r2 > 0.92) for the range from 1.87 to 5.69 μg chl a.cm-2. The strength of the BQ index lies in its double use as a biomarker of quantity and percentage cover, as well as its good performance under different conditions, ranging from initial phototrophic colonization and thin (young) biofilms covering 21.19% of the surface to profuse biological colonization covering 67.36% of the surface. Moreover, the proposed BQ index may be able to be used with other types of rock with less heterogeneous surfaces than granite. [ABSTRACT FROM AUTHOR]

Titanium surface characteristics, including microtopography, chemical composition, and wettability, are essential features to achieve osseointegration of dental implants, but the choice of a particular surface topography is still a debated topic among clinicians. An increased level of implant surface hydrophilicity has been demonstrated to ameliorate osseointegration and shorten healing times. The aim of this work is to develop and test a suitable thermal-based method to enhance titanium surface wettability without modifying other characteristics of the implant surface. For this function, titanium discs with different surface topography have been thermally treated by testing different temperatures and excluding those that led to evident chromatic and morphological modifications. The selected surface gain in wettability after the treatment was assessed through contact angle measurement, chemistry modifications through x-ray photoelectron spectroscopy (XPS) analysis, and microtopography through scanning electron microscopy (SEM). Results showed a great enhancement in hydrophilicity on the tested surfaces without any other modification in terms of surface chemical composition and topography. A possible limitation of this method could be the persistent, although relatively slow, biological aging of the surfaces after the treatment. The present findings indicate that the described treatment could be a safe and effective method to enhance dental titanium hydrophilicity and thus its biological performance. [ABSTRACT FROM AUTHOR]

Wear due to over-pressure is a well-known phenomenon that appears on bush bearing under off-center load. In this context, this paper proposes a methodology to develop a new bearing inspired from a lamb elbow. This bio-inspired bearing could replace bush bearing from helicopter's system. The method starts with the analysis of the contact surfaces of the biological joint from 3D scans. That allowed to extract a revolute profile for the bio-inspired bearing. Finite element simulations were then realized to find the best clearance specification to reduce contact pressure. The bio-inspired bearing is after optimized using Design Of Experiments method. [ABSTRACT FROM AUTHOR]

• Ceramic membrane is modified by imitating of superhydrophobic biological surfaces. • The micro/nano hierarchical structure with low surface energy endows the superhydrophobicity. • The P-ZN-CHF membrane obtains antifouling ability. • The modified membrane shows excellent performances during vacuum membrane distillation. To solve the problems of membrane material tolerance and membrane fouling, a micro/nano hierarchial structure with low surface energy was constructed above the exterior surface of a ceramic hollow fiber membrane using ZnO nanorod arrays and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PDTS) coatings, which make it superhydrophobic and self-cleaning. The surface morphology, chemical functional groups, and water contact angel of the modified membranes were identified. The results show that large quantity of ZnO nanorods possess desirable characteristics (i.e. superhydrophobicity, exceptional thermal and mechanical stability, and water contact angle of 160.12°) were detected on the ceramic membrane. The novel membrane shows excellent self-cleaning performance and good desalination ability in the utilization of vacuum membrane distillation (VMD) system for high-salinity water desalination. [ABSTRACT FROM AUTHOR]

To better understand the onset of damage occurring in the brain upon traumatic events, it is essential to analyze how external mechanical loads propagate through the skull and meninges and down to the brain cortex. However, despite their crucial role as structural dampers protecting the brain, the mechanical properties and dynamic behavior of the meningeal layers are still poorly understood. Here, we characterized the local mechanical heterogeneity of rat pia-arachnoid complex (PAC) at the microscale via atomic force microscopy (AFM) indentation experiments to understand how microstructural variations at the tissue level can differentially affect load propagation. By coupling AFM mechanical testing with fresh tissue immunofluorescent staining, we could directly observe the effect of specific anatomical features on the local mechanical properties of tissue. We observed a two-fold stiffening of vascularized tissue when compared to non-vascularized PAC (with instantaneous Young's modulus distribution means of 1.32 ± 0.03 kPa and 2.79 ± 0.08 kPa, respectively), and statistically significant differences between regions of low- and high-vimentin density, reflecting trabecular density (with means of 0.67 ± 0.05 kPa and 1.29 ± 0.06 kPa, respectively). No significant differences were observed between cortical and cerebellar PAC. Additionally, by performing force relaxation experiments at the AFM, we identified the characteristic time constant τ 1 of PAC tissue to be in the range of 2.7 ± 1.2 s to 3.1 ± 0.9 s for the different PAC regions analyzed. Taken together, the results presented point at the complex biomechanical nature of the meningeal tissue, and underscore the need to account for its heterogeneity when modeling its behavior into finite element simulations or other computational methods enabling the prediction of load propagation during injury events. The meningeal layers are pivotal in shielding the brain during injury events, yet the mechanical properties of this complex biological interface are still under investigation. Here, we present the first anatomically-informed micromechanical characterization of mammalian pia-arachnoid complex (PAC). We developed a protocol for the isolation and fresh immunostaining of rat PAC and subjected the tissue to AFM indentation and relaxation experiments, while visualizing the local anatomy via fluorescence microscopy. We found statistically significant variations in regional PAC stiffness according to the degree of vascularization and trabecular cell density, besides identifying the tissue's characteristic relaxation constant. In essence, this study captures the relationship between anatomy and mechanical heterogeneity in a key component of the brain-skull interface for the first time. [ABSTRACT FROM AUTHOR]

The extensive application of amorphous silica nanoparticles (aSiNPs) in recent years has resulted in unavoidable human exposure in daily life, thus raising widespread concerns regarding the safety of aSiNPs on human health. The particle size is one of the important characteristics of nanomaterials that could influence their toxicity. For the reason that particles with smaller sizes possess larger surface area, which may lead to higher surface activity and biological reactivity. However, due to the complexity of experimental conditions and biological systems, the relationship between the particle size and the toxic effect of aSiNPs remains unclear. Therefore, this systematic review aims to investigate how particle size influences the toxic effect of aSiNPs in vivo and to analyze the relevant experimental factors affecting the size-dependent toxicity of aSiNPs in vivo. We found that 83.8% of 35 papers included in the present review came to the conclusion that smaller-sized aSiNPs exhibited stronger toxicity, though a few papers (6 papers) put forward different opinions. The reasons for smaller aSiNPs manifested greater toxicity were summarized. In addition, certain important experimental factors could influence the size-dependent effects and in vivo toxicity of aSiNPs, such as the synthesis method of aSiNPs, disperse medium of aSiNPs, administration route of aSiNPs, species or strain of experimental animals, sex of experimental animals, aggregation/agglomeration and protein corona of aSiNPs. [Display omitted] • The article size is an important factor which impacts the in vivo toxicity of aSiNPs. • 83.8% included papers showed that smaller-sized aSiNPs exhibited stronger toxicity. • Reasons for smaller aSiNPs did or did not exhibit stronger toxicity were explored. • Some experimental factors would influence the size-dependent toxicity of aSiNPs. [ABSTRACT FROM AUTHOR]

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biological systems continuously interact with the surrounding environment because they are dynamically evolving. The interaction is achieved through mechanical, electrical, chemical, biological, thermal, optical, or a synergistic combination of these cues. To provide a fundamental understanding of the interaction, recent efforts that integrate biological systems with the electronic-mechanical assemblies create unique opportunities for simultaneous monitoring and eliciting the responses to the biological system. Recent innovations in materials, fabrication processes, and device integration approaches have created the enablers to yield bio-integrated devices to interface with the biological system, ranging from cells and tissues to organs and living individual. In this short review, we will provide a brief overview of the recent development on the integration of the biological systems with electronic-mechanical assemblies across multiple scales, with applications ranging from healthcare monitoring to therapeutic options such as drug delivery and rehabilitation therapies. An overview of the recent progress on the integration of the biological system with both electronic and mechanical assemblies is discussed. The integration creates the unique opportunity to simultaneously monitor and elicit the responses to the biological system, which provides a fundamental understanding of the interaction between the biological system and the electronic-mechanical assemblies. Recent innovations in materials, fabrication processes, and device integration approaches have created the enablers to yield bio-integrated devices to interface with the biological system, ranging from cells and tissues to organs and living individual. [ABSTRACT FROM AUTHOR]

• Recent progresses in fabricating G-BFNs for advanced biological and cellular interfaces are summarized. • Diverse facile and eco-friendly strategies for the synthesis and functionalization of G-BFNs are outlined. • Current developed G-BFNs based on their nanostructures and biofunctionalities have been carefully discussed. • Biointeractions and biocompatibilities at the interfaces of G-BFNs with viruses, bacteria and stem cells are highlighted. • Emerging biological applications and future perspectives of G-BFNs are discussed. Currently, abundant efforts have been devoted to research on graphene in interdisciplinary applications due to their unique physicochemical, electronic and biological properties. Accompanying the rapid developments of graphene, it is highly important to explore graphene based bio-functional nanostructures (G-BFNs) to bridge the gap between the fundamental advantages of graphene and the requirements in designing hybridized biomaterials. Here, this review aims to outline and summarize the recent advancements in fabricating G-BFNs for advanced biological and cellular interfaces. We first discuss the general protocols for the synthesis of G-BFNs, especially diverse facile and eco-friendly strategies. Then, we carefully summarize the current developed G-BFNs based on their nanostructures and biofunctionalities, such as physiologically-stability, stimuli-responsibility, graphene-inorganic nanohybrids, functional nano-inks, nacre-like layered composites, macroporous scaffolds, 3D printed microlattices, and injectable hydrogels. Moreover, biointeractions at the interfaces of G-BFNs with viruses, bacteria and stem cells, and the relevant biocompatibilities are also highlighted. Furthermore, the emerging applications and future perspectives of G-BFNs in nanotherapeutics, anti-pathogens, tissue regeneration, and monitoring biosensors are carefully discussed. We envision that such a timely and cutting-edge review will not only take a step towards the development of G-BFNs but also inspire new opportunities by using emerged nanomaterials for biological and cellular interfaces. [ABSTRACT FROM AUTHOR]

Abstract Ultra High Molecular Weight Polyethylene (UHMWPE), with a semi-trapezoidal topography, and glass samples were coated with a TiAlV film using magnetron sputtering in order to study its structure, chemical composition and the adhesion film properties on the polymer surfaces. The magnetron sputtering is a PVD technique that depending on the deposited parameter produces a coating with structural, chemical and specific topographic characteristics that increase the electrical, mechanical, optical and biological surface properties of the organic compounds. The quantities of Vanadium (V) and Aluminum (Al) were similar to that of Ti64 alloy. The metallic film obtained presents α-Ti phase structure with a (200) preferential orientation. The TiAlV film on polymeric surfaces with semi-trapezoidal topography exhibit irregularities and uncoated zones but on the glass, the metallic coating was smooth and continuous. The scratch tests were carried out using an incremental load configuration with a Tribotechnic scratch tester equipment. The metallic film decreased the viscoelastic recovering of the polymeric surface but increased the load capacity. The metallic film did not present complete delamination but fractures and small zones of coating detachment were observed on all the scratch tracks. Highlights • The coating of a texture polymeric surfaces with a TiAlV metallic film; • Structural, chemical and topographic characterization of a polymeric coated surfaces; • Improve of the polymeric load capacity of the surfaces with a metallic film; • 3D topography on UHMWPE surfaces; [ABSTRACT FROM AUTHOR]

Abstract The protective function of biological surfaces that are exposed to the exterior of living organisms is the result of a complex arrangement and interaction of cellular components. This is the case for the most external cornified layer of skin, the stratum corneum (SC). This layer is made of corneocytes, the elementary 'flat bricks' that are held together through adhesive junctions. Despite the well-known protective role of the SC under high mechanical stresses and rapid cell turnover, the subtleties regarding the adhesion and mechanical interaction among the individual corneocytes are still poorly known. Here, we explore the adhesion of single corneocytes at different depths of the SC, by pulling them using glass microcantilevers, and measuring their detachment forces. We measured their interplanar adhesion between SC layers, and their peripheral adhesion among cells within a SC layer. Both adhesions increased considerably with depth. At the SC surface, with respect to adhesion, the corneocyte population exhibited a strong heterogeneity, where detachment forces differed by more than one order of magnitude for corneocytes located side by side. The measured detachment forces indicated that in the upper-middle layers of SC, the peripheral adhesion was stronger than the interplanar one. We conclude that the stronger peripheral adhesion of corneocytes in the SC favors an efficient barrier which would be able to resist strong stresses. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The development of mucoadhesive materials is of great interest and is also a major challenge. Being adsorption sites, mucosae are suitable targets for drug delivery, but as defensive barriers they are complex biological surfaces to interact with, mainly due to their protective mucus layer. As such, first- and second-generation mucoadhesives focused on material-mucus interactions, whereas the third generation of mucoadhesives introduced structural motifs that are able to interact with the cells beneath the mucus layer. The combination of different prerequisites (water solubility, soft gel formation at body temperature and able to interact with the mucus) in a single molecule is easily achieved using elastin-like recombinamers (ELRs) given their multiple block design. Moreover, we have been able to introduce a short amino-acid sequence known as T7 that is able to bind to transferrin receptors in the epithelial cell layer. The T7 sequence enhances the cell-binding properties of the mucoadhesive ELR (MELR), as demonstrated using a Caco-2 epithelial cell model. In vivo experiments confirmed the mucoadhesive properties found in vitro. Statement of Significance The development of a mucoadhesive material is a major challenge. Mucosae are suitable targets for drug delivery, but as defense barriers, they are complex surfaces to interact with. In this work we report the first ELR that combines different functional blocks, in a single molecule, which provide it with the properties of soft-gel forming at body temperature and being able of efficiently adhering to the mucus layer of mucosas, as well as to the underlying epithelial cell layer, as demonstrated in vitro and in vivo. The rationally designed materials presented in this work sets the basis for developing ELR-based, mucosa-directed drug delivery systems, which could improve patient's compliance, enhancing drug retention at the mucosal site. [ABSTRACT FROM AUTHOR]

Biological composites incorporate structural arrays of rigid-elastic reinforcements made of minerals or crystalline biopolymers, which are connected by thin, compliant, and viscoelastic macromolecular matrix material. The near-interface regions of these biological composites grant them energy dissipation capabilities against dynamic mechanical loadings, which promote various biomechanical functions such as impact adsorption, fracture toughness, and mechanical signal filtering. Here, we employ theoretical modeling and finite-element simulations to analyze the mechanical response of the near-interface in biological composites to nanoscale dynamic mechanical analysis (DMA). We identified the dominating load-bearing mechanisms of the near-interface region and employed these insights to introduce simple semi-empirical formulations for approaching the mechanical properties (storage and loss moduli) of the biological composite from the nanoscale DMA results. Our analysis paves the way for the nanomechanical characterization of biological composites in diverse natural materials systems, which can also be employed for bioinspired and biomedical configurations. [ABSTRACT FROM AUTHOR]

The direct and indirect (by changing mechanical properties) effects of hydration at interfaces on cellular processes and tissue diseases are reviewed. The essential effect of substrate stiffness on cellular processes was demonstrated in the last decade. The combined effect of surface stiffness and hydration at interfaces has garnered much less attention, though hydration and dehydration play important roles in biological processes. This review focuses on the studies that demonstrate how hydration affects biological processes at interfaces. Elevated sodium and dehydration stimulate inflammatory signaling in endothelial cells and promote atherosclerosis. Various types of implant and blood contacting device coatings with varied surface stiffness and hydration have been reported. Effect of hydration on polymer modulus of elasticity and viscoelasticity was discussed taking into account cells adhesion, migration, proliferation, differentiation on surfaces with various degree of hydration. Future directions of research were considered, including the use of nanotechnology to regulate the hydration degree. [ABSTRACT FROM AUTHOR]

Fluoride (F-) contamination of groundwater is a silent killer of human health that has now become a global problem. In the present study, we sought to isolate fluoride-resistant, urease producing bacteria from F- contaminated groundwater to evaluate their potential F- biomineralization. Strain MLN9, isolated from the fluoride-contaminated village of Madhabpur in Birbhum, could resist up to 5600 mg L−1 F- concentration. Taxonomic classification of strain MLN9 based on whole genome sequence identified it as Proteus columbae MLN9. Strain MLN9 showed 88.9% of maximum F- removal efficiency at pH 8.0, 1.0 g L−1 CaCl 2 , and 10.0 g L−1 urea concentration. Scanning electron micrographs showed dense and porous biological crystal precipitates surrounding the surface of the bacterial cells, and the adherence of F- to the cell surface was confirmed by the energy dispersion spectrum. Moreover, the X-ray diffraction pattern showed that the F- precipitates on the cell surface were biological crystals of Ca 5 (PO 4) 3 F and CaF 2. Genomic analysis of strain MLN9 revealed the presence of crcB gene homologs possibly encoding F- transporters and urease regulatory proteins such as UreA, UreB, UreC, UreD, and UreG suggesting a role in defluoridation. Our findings provide new insights into the urease based MICP technology using a noble bacterium Proteus columbae MLN9 for fluoride removal. [Display omitted] • Urease-mediated fluoride biomineralization identified in P. columbae strain MLN9. • Maximum of 88.9% F- removal efficiency was achieved at optimized condition. • MICP based F- removal process was in the form of CaF 2 and Ca 5 (PO 4) F. • crcB gene homolog of F- transporter and urease operon may involve in defluoridation. [ABSTRACT FROM AUTHOR]

On-surface synthesis is the bottom-up construction of covalent bonds between molecular building blocks, which has been greatly developed during the past decade. Dozens of reactions have been successfully realized and scrutinized on various surfaces with the help of surface science techniques combined with theoretical calculations. Functional nanoarchitectures such as one-dimensional nanowires, nanoribbons and two-dimensional nanonetworks have been constructed on surfaces and explored in several potential applications. In fact, the generation of multilevel nanostructures will play a key role in future soft nanoscience and technologies due to their emergent properties ranging far beyond those of the individual molecules building them up. In this review, we discuss selected examples of important processes in on-surface synthesis developed in recent years and summarize them under the following aspects: (1) on-surface reactions in a category of different carbon types; (2) techniques applied in on-surface synthesis; (3) on-surface synthesized functional nanostructures; and (4) potential applications of on-surface synthesized nano-materials. The review concludes with a perspective of the future development of on-surface synthesis. [ABSTRACT FROM AUTHOR]

Estimates of landscape connectivity are routinely used to inform decision-making by conservation biologists. Most estimates of connectivity rely on cost-surfaces: raster representations of landscapes in which cost values represent the difficulty involved with traversing an area. However, there is considerable uncertainty in the generation of cost-surfaces that have not been widely explored. We investigated the effects of four potential sources of uncertainty in the creation of cost-surfaces: 1) number of landscape classes represented; 2) spatial resolution (grain size); 3) misclassification of edges between landscape classes; and 4) cost values selected for each landscape class. Following a factorial design we simulated multiple cost-surface pairs, each comprising one true surface with no errors and one surface with uncertainty comprised of some combination of the four error sources. We evaluated the relative importance of each source of uncertainty in determining the difference between the least-cost paths (LCPs) costs and resistance distances generated for the true and erroneous cost-surfaces, using four model evaluation metrics. Errors in the underlying geospatial layers produced larger inaccuracies in connectivity estimates than those produced by cost-value errors. Incorrect grain size had the largest overall effect on the accuracy of connectivity estimates. Though the removal of an element class was found to have a large effect on the configuration of connectivity estimates, and the addition of an element class had a large effect on estimates configuration. Our results highlight the importance of minimising and quantifying the uncertainty inherent in the geospatial data used to develop cost-surfaces. [ABSTRACT FROM AUTHOR]

Surface modification is crucial for conferring novel functionalities to objects and interfaces. However, simple yet versatile strategies for the surface modification of multiple classes of nanomaterials, including biointerfaces, are rare, as the chemical interactions between the surface modifiers and the substrates need to be tailored on a case-by-case basis. Recently, metal-phenolic networks (MPNs) have emerged as a versatile surface modifier based on the universal adherent properties of phenolic molecules, namely the constituent gallol and catechol groups. Additionally, the dynamic interactions between metal ions and phenolic molecules confer additional functionalities to the MPNs, such as stimuli-responsiveness. Given the interest in MPNs for nanomaterial and biointerface engineering, this review aims to provide an overview of the assembly process, physicochemical properties and applications of MPN coatings. [ABSTRACT FROM AUTHOR]

Spatio-ecological heterogeneity is strongly linked to many ecological processes and functions such as plant species diversity patterns and change, metapopulation dynamics, and gene flow. Remote sensing is particularly useful for measuring spatial heterogeneity of ecosystems over wide regions with repeated measurements in space and time. Besides, developing free and open source algorithms for ecological modelling from space is vital to allow to prove workflows of analysis reproducible. From this point of view, NASA developed programs like the Surface Biology and Geology (SBG) to support the development of algorithms for exploiting spaceborne remotely sensed data to provide a relatively fast but accurate estimate of ecological properties in vast areas over time. Most of the indices to measure heterogeneity from space are point descriptors : they catch only part of the whole heterogeneity spectrum. Under the SBG umbrella, in this paper we provide a new R function part of the rasterdiv R package which allows to calculate spatio-ecological heterogeneity and its variation over time by considering all its possible facets. The new function was tested on two different case studies, on multi- and hyperspectral images, proving to be an effective tool to measure heterogeneity and detect its changes over time. [ABSTRACT FROM AUTHOR]

Growing interest of endosseous implant research is focused on surface modification to achieve early and strong osseointegration. The present study compared the behaviour of hydroxyapatite coated, zinc doped hydroxyapatite coated and hydrothermally treated titanium (Ti6Al4V) with machined Ti6Al4V implants (control) on osseointegration. The surface characterization and bacterial affinity test for implants were performed. Forty eight (48) cylinders (4 types in each animal) were placed in the humerus bone of 12 black Bengal goats. Bone–implant interface was examined with histological, radiological parameters and scanning electron microscopy on 42nd, 90th, and 180th day post-implantation. Surface roughness alterations of bone-detached implants with time were analyzed by non-contact profilometer. Push-out test (90th day) was performed to assess the strength of bony integration of implants. The coated implants revealed direct and early bone–implant contact but high bacterial affinity and coating resorption/cracks. Low bacterial affinity and strongest osseointegration was observed with hydrothermally treated implants. Poor bacterial affinity and delayed but strong fixation were evident with control implant. Based on the results of laboratory and animal experiments, we conclude that the hydrothermal modification of titanium implant is the more suitable way to achieve safe and effective osseointegration than the other three implant types for endosseous application. [ABSTRACT FROM AUTHOR]

The measurement uncertainty of strains has been assessed in a bone analogue (sawbone), bovine trabecular bone and bone–cement interface specimens under zero load using the Digital Volume Correlation (DVC) method. The effects of sub-volume size, sample constraint and preload on the measured strain uncertainty have been examined. There is generally a trade-off between the measurement uncertainty and the spatial resolution. Suitable sub-volume sizes have been be selected based on a compromise between the measurement uncertainty and the spatial resolution of the cases considered. A ratio of sub-volume size to a microstructure characteristic (Tb.Sp) was introduced to reflect a suitable spatial resolution, and the measurement uncertainty associated was assessed. Specifically, ratios between 1.6 and 4 appear to give rise to standard deviations in the measured strains between 166 and 620 με in all the cases considered, which would seem to suffice for strain analysis in pre as well as post yield loading regimes. A microscale finite element (μFE) model was built from the CT images of the sawbone, and the results from the μFE model and a continuum FE model were compared with those from the DVC. The strain results were found to differ significantly between the two methods at tissue level, consistent in trend with the results found in human bones, indicating mainly a limitation of the current DVC method in mapping strains at this level. [ABSTRACT FROM AUTHOR]

Recent advances in dynamic biointerfaces enable spatiotemporal control over cell position and migration after attachment using substrates that employ chemical, optical, thermal, or electrical triggers. This review focuses on flexible and accessible methods for the fabrication of cellular arrays or co cultures for fundamental studies of cell biology or regenerative medicine. [ABSTRACT FROM AUTHOR]

We have developed a strain-gauge cantilever-based biosensor with liposomes as model cell membrane immobilized on the cantilever surface to investigate time course of dynamic behavior of amyloid-beta (1-40) protein (Aβ(1-40)) on lipid membrane. The results of this work clearly exhibit the characteristic of chronological change of the gauge resistance, which is closely related to the dependence of Aβ-liposome interaction extent on the state of Aβ during fibrillization and the type of lipid molecule. Therefore, it is considered that these results can adequately reflect the fibrillization process of Aβ(1-40) on different kinds of lipid membranes. Meanwhile, it means that we are able to discriminate the molecular states of Aβ and evaluate Aβ fibrillization process using the cantilever-based liposome biosensor. [ABSTRACT FROM AUTHOR]

Summary Silver nanoparticles constitute a very promising approach for the development of new antimicrobial systems. Nanoparticulate objects can bring significant improvements in the antibacterial activity of this element, through specific effect such as an adsorption at bacterial surfaces. However, the mechanism of action is essentially driven by the oxidative dissolution of the nanoparticles, as indicated by recent direct observations. The role of Ag + release in the action mechanism was also indirectly observed in numerous studies, and explains the sensitivity of the antimicrobial activity to the presence of some chemical species, notably halides and sulfides which form insoluble salts with Ag + . As such, surface properties of Ag nanoparticles have a crucial impact on their potency, as they influence both physical (aggregation, affinity for bacterial membrane, etc. ) and chemical (dissolution, passivation, etc. ) phenomena. Here, we review the main parameters that will affect the surface state of Ag NPs and their influence on antimicrobial efficacy. We also provide an analysis of several works on Ag NPs activity, observed through the scope of an oxidative Ag + release. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of electronspun PLGA/HAp/Zein scaffolds on the repair of cartilage defects. Methods The PLGA/HAp/Zein composite scaffolds were fabricated by electrospinning method. The physiochemical properties and biocompatibility of the scaffolds were separately characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and fourier transform infrared spectroscopy (FTIR), human umbilical cord mesenchymal stem cells (hUC-MSCs) culture and animal experiments. Results The prepared PLGA/HAp/Zein scaffolds showed fibrous structure with homogenous distribution. hUC-MSCs could attach to and grow well on PLGA/HAp/Zein scaffolds, and there was no significant difference between cell proliferation on scaffolds and that without scaffolds ( P >0.05). The PLGA/HAp/Zein scaffolds possessed excellent ability to promote in vivo cartilage formation. Moreover, there was a large amount of immature chondrocytes and matrix with cartilage lacuna on PLGA/HAp/Zein scaffolds. Conclusion The data suggest that the PLGA/HAp/Zein scaffolds possess good biocompatibility, which are anticipated to be potentially applied in cartilage tissue engineering and reconstruction. [ABSTRACT FROM AUTHOR]