Bovine Serum Fibrinogen Research Articles

A green zwitterionic bi-continuous membranes prepared by dual-bath procedure for mitigating biofouling during bacterial removal from water

This work explores the possibility of forming green microfiltration antifouling membranes based on polyvinylidene fluoride (PVDF) and a zwitterionic copolymer derivative of sulfobetaine methacrylate (SBMA), utilizing gamma-valerolactone (GVL) as the solvent and a mixture of ethanol and water as non-solvents. Efforts were initially focused on adjusting the immersion time of the matrix polymer in alcohol alone to obtain a porous structure, and 15 s were sufficient to achieve a symmetric, open porous morphology. Next, the polymer/copolymer/solvent blend was characterized. While it did not show the characteristics of a fully miscible system, DLS and visual observations revealed the obtaining of a homogeneous (relatively narrow particle size) and transparent to translucent system. Thus, membranes could be cast, and were shown to be stable. The addition of the copolymer maintained the physical characteristics of microfiltration membranes, but an FT-IR analysis revealed its effect on the dominant crystalline polymorph (switching from β to α). The membrane wettability was enhanced in an important extent with a dynamic water contact angle (WCA) gradually falling to < 40° (while the virgin membrane's WCA remained about 138° all test long), and a hydration capacity reaching about 530 mg/cm3 against <10 mg/cm3 for the virgin membrane. It reflected on the antifouling abilities of the membranes as tested using bovine serum albumin, fibrinogen, Escherichia coli, and Stenotrophomonas maltophilia, with relative decreases in adsorption during static tests measured to be 95 %, 70 %, 91 % and 98 %, respectively. Finally, compared to the virgin membrane, the modified membrane featured improved flux recovery (32 % vs. 11 %), significantly higher rejection (98.9 % vs. 89.1 %) and lower irreversible fouling tendency (68 % vs. 89 %) during cyclic water/bacterial solution filtration in dead-end mode, making it potentially suitable for addressing bacterial pollution in wastewater.

Novel magnetic iron oxide-dextran sulphate nanocomposites as potential anticoagulants: Investigating interactions with blood components and assessing cytotoxicity

Examining the critical role of anticoagulants in medical practice, particularly their central function in preventing abnormal blood clotting, is of the utmost importance. However, the study of interactions between blood proteins and alternative anticoagulant nano-surfaces is still understood poorly. In this study, novel approach involving direct functionalisation of magnetic iron oxide nanoparticles (MNPs) as carriers with sulphated dextran (s-dext) is presented, with the aim of evaluating the potential of magnetically-responsive MNPs@s-dext as anticoagulants. The physicochemical characterisation of the synthesised MNPs@s-dext includes crystal structure analysis, morphology study, surface and electrokinetic properties, thermogravimetric analysis and magnetic properties` evaluation, which confirms the successful preparation of the nanocomposite with sulfonate groups. The anticoagulant potential of MNPs@s-dext was investigated using a standardised activated partial thromboplastin time (APTT) test and a modified APTT test with a quartz crystal microbalance with dissipation (QCM-D) which confirmed the anticoagulant effect. Time-resolved solid-liquid interactions between the MNPs@s-dext and model blood proteins bovine serum albumin and fibrinogen were also investigated, to gain insight into their hemocompatibility, and revealed protein-repellence of MNPs@s-dext against blood proteins. The study also addressed comprehensive cytotoxicity studies of prepared nanocomposites, and provided valuable insights into potential applicability of MNPs@s-dext as a promising magnetic anticoagulant in biomedical contexts.

Bioinspired Self-Adhesive Multifunctional Lubricated Coating for Biomedical Implant Applications.

In the realm of clinical applications, the concern surrounding biomedical device-related infections (BDI) is paramount. To mitigate the risk associated with BDI, enhancing surface characteristics such as lubrication and antibacterial efficacy is considered as a strategic approach. This study delineated the synthesis of a multifunctional copolymer, embodying self-adhesive, lubricating, and antibacterial properties, achieved through free radical polymerization and a carbodiimide coupling reaction. The copolymer was adeptly modified on the surface of stainless steel 316L (SS316L) substrates by employing a facile dip-coating technique. Comprehensive characterizations were performed by using an array of analytical techniques including Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, optical interferometry, scanning electron microscopy, and atomic force microscopy. Nanoscale tribological assessments revealed a notable reduction in the value of the friction coefficient of the copolymer-coated SS316L substrates compared to bare SS316L samples. The coating demonstrated exceptional resistance to protein adsorption, as evidenced in protein contamination models employing bovine serum albumin and fibrinogen. The bactericidal efficacy of the copolymer-modified surfaces was significantly improved against pathogenic strains such as Staphylococcus aureus and Escherichia coli. Additionally, in vitro evaluations of blood compatibility and cellular compatibility underscored the remarkable anticoagulant performance and biocompatibility. Collectively, these findings indicated that the developed copolymer coating represented a promising candidate, with its facile modification approach, for augmenting lubrication and antifouling properties in the field of biomedical implant applications.

PEG-functionalized aliphatic polycarbonate brushes with self-polishing dynamic antifouling properties

Hydrophilic antifouling polymers provide excellent antifouling effects under usual short-term use conditions, but the long-term accumulation of contaminants causes them to lose their antifouling properties. To overcome this drawback, surface-initiated ring-opening graft polymerization (SI-ROP) was performed on the surface of the material by applying the cyclic carbide monomer 4′-(fluorosulfonyl)benzyl-5-methyl-2-oxo-1,3-dioxane-5-carboxylate (FMC), which contains a sulfonylfluoride group on the side chain, followed by a “sulfur(IV)-fluorine exchange” (SuFEx) post click modification reaction to link the hydrophilic polyethylene glycol (PEG) to the polyFMC (PFMC) brush, and a novel antifouling strategy for self-polishing dynamic antifouling surfaces was developed. The experimental results showed that the antifouling surface could effectively prevent the adsorption of proteins such as bovine serum albumin (BSA, ∼96.4%), fibrinogen (Fg, ∼87.8%) and lysozyme (Lyz ∼69.4%) as well as the adhesion of microorganisms such as the bacteria Staphylococcus aureus (S. aureus) (∼87.5%) and HeLa cells (∼67.2%). Moreover, the enzymatically self-polished surface still has excellent antifouling properties. Therefore, this modification method has potential applications in the field of biosensors and novel antifouling materials.

Non-fibril amyloid aggregation at the air/water interface: self-adaptive pathway resulting in a 2D Janus nanofilm.

The amyloid states of proteins are implicated in several neurodegenerative diseases and bioadhesion processes. However, the classical amyloid fibrillization mechanism fails to adequately explain the formation of polymorphic aggregates and their adhesion to various surfaces. Herein, we report a non-fibril amyloid aggregation pathway, with disulfide-bond-reduced lysozyme (R-Lyz) as a model protein under quasi-physiological conditions. Very different from classical fibrillization, this pathway begins with the air-water interface (AWI) accelerated oligomerization of unfolded full-length protein, resulting in unique plate-like oligomers with self-adaptive ability, which can adjust their conformations to match various interfaces such as the asymmetric AWI and amyloid-protein film surface. The pathway enables a stepwise packing of the plate-like oligomers into a 2D Janus nanofilm, exhibiting a divergent distribution of hydrophilic/hydrophobic residues on opposite sides of the nanofilm. The resulting Janus nanofilm possesses a top-level Young's modulus (8.3 ± 0.6 GPa) among amyloid-based materials and exhibits adhesive strength two times higher (145 ± 81 kPa) than that of barnacle cement. Furthermore, we found that such an interface-directed pathway exists in several amyloidogenic proteins with a similar self-adaptive 2D-aggregation process, including bovine serum albumin, insulin, fibrinogen, hemoglobin, lactoferrin, and ovalbumin. Thus, our findings on the non-fibril self-adaptive mechanism for amyloid aggregation may shed light on polymorphic amyloid assembly and their adhesions through an alternative pathway.

Preparation of aminated poly (L‐lactic acid) film coated with multilayers of mussel‐inspired heparin‐like carboxymethylcellulose sodium and chitosan for anticoagulant materials

AbstractIn this study, dopamine hydrochloride was grafted onto the sulfated carboxymethylcellulose sodium with different sulfated degree (DA‐g‐SCMCS) as heparin‐like polysaccharides. By studying the preliminary structure and coagulation time of DA‐g‐SCMCS, the DA‐g‐SCMC2 possessing good anticoagulant properties were selected to be assembled layer by layer on the surface of aminated poly (L‐lactic acid) (APLLA) film with chitosan (CS). The characterization properties including morphologies and wettability of DA‐g‐SCMC2/CS multilayers modified APLLA films were studied by scanning electron microscope and water contact angle instrument. Anticoagulation tests revealed that the (DA‐g‐SCMC2/CS)15 multilayers modified APLLA film experienced a decrease of 37.5% and 73.68% in the adsorption of bovine serum albumin (BSA) and fibrinogen (FBG), respectively. And the platelet adhesion ability was reduced by 92.42% compared with the APLLA film. The degree of platelet activation (PF4 and TAT) and hemolysis rates of modified APLLA films also decreased significantly. Besides, the modified APLLA films promoted the growth of L929 cells and exhibited remarkable anti‐inflammatory and antibacterial abilities. To summarize, the APLLA films modified with heparin‐like multifunctional DA‐g‐SCMC2/CS multilayers exhibit outstanding biocompatibility, cytocompatibility, anti‐inflammatory, and antibacterial characteristics, showcasing their potential as anticoagulation materials.

Tuning physical properties of polyurethane hard segments through extender chain length variation and doping of pentaerythritol and their effect on in vitro protein adsorption

AbstractThis study explores the synthesis and characterization of polyurethanes (PUs) derived from hexamethylene diisocyanate (HDI) and 1,n‐alkane diols with varying chain lengths (n = 4, 6, and 10). Additionally, pentaerythritol (PE) is introduced as a dopant in PU6 at different weight percentages (25%, 50%, 75%, and 1:1%w/w). The research encompasses a comprehensive analysis of PU properties, including morphology, crystallinity, surface area, porosity, thermal behavior, rheological properties, and electrical conductivity. Of particular interest is the evaluation of protein adsorption capabilities employing bovine serum albumin (BSA) and fibrinogen proteins in in vitro tests. The study emphasizes the crucial role played by the chain length between isocyanate and diol groups and the nature and strength of hydrogen bonds among chains in shaping the polymer's properties, especially crystallinity and biocompatibility. Among the synthesized PUs, PU6 emerges as the top performer in terms of crystallinity and biocompatibility. Furthermore, the addition of PE is found to act as a plasticizer, reducing the glass transition temperature (Tg) from 75°C to 31°C. Electrochemical Impedance Spectroscopy shows that doping influences charge transfer processes, rendering the material semi‐conducting, as evidenced by decreased conductance when adding silver nanoparticles to PU6. Notably, protein adsorption studies reveal that undoped PU6 displays superior protein resistance compared to its doped counterpart, with fibrinogen exhibiting a higher adsorption affinity than BSA. The study discusses a plausible mechanism underlying protein adsorption.

Antifouling Surfaces Based on Polyzwitterion Loop Brushes.

Antifouling surfaces have attracted increasing interest in recent years due to their potential application in various fields. In this work, we report a loop polyzwitterionic coating that exhibits excellent resistance to protein adsorption. Triblock and diblock copolymers of 2-[(2-hydroxyethyl)disulfanyl]ethyl methacrylate) (HSEMA) and 2-(dimethylamino)ethyl methacrylate) (DMAEMA) were synthesized by atom-transferred radical polymerization, followed by betainization of the DMAEMA block with 1,3-propane sultone and reduction of the disulfide bond in HSEMA to yield a triblock copolymer comprising a zwitterionic poly(sulfobetaine methacrylate) (PSBMA) midblock and poly(2-sulfanylethyl methacrylate) (PSEMA) terminal blocks as well as its diblock analogue that was of the same composition as the former and half the chain length. Both copolymers adsorbed to the gold substrate via the thiol groups in the terminal PSEMA block(s), creating loop and linear PSBMA brush coatings of comparable thickness, as revealed by X-ray photoelectron spectroscopy and ellipsometry. Adsorption of bovine serum albumin and fibrinogen as model proteins from solution to these surfaces was investigated by a quartz crystal microbalance with dissipation and confocal laser scanning microscopy (CLSM), and platelet and bacterial adhesions were assessed by scanning electron microscopy and CLSM. The results demonstrate that both linear and loop polyzwitterion brushes are excellent in resisting the adsorption of the foulants, and the loop brushes are superior to the linear analogues.

Enhancement of protein immobilization on polydimethylsiloxane using a synergistic combination of polydopamine and micropattern surface modification

Understanding protein interactions at biointerfaces is critical for the improved design of biomaterials and medical devices. Polydimethylsiloxane (PDMS) is used for numerous device applications, and surface modifications can enhance protein immobilization and the response to cells. A multifunctional approach combining topographical and biochemical modifications was applied to PDMS by fabricating 10–20 µm scale patterns onto PDMS surfaces and by coating with polydopamine (PDA). The modifications were confirmed by surface characterization and bovine serum albumin (BSA), fibrinogen (Fg), and fetuin-A (Fet-A) were radiolabeled with 125I. The amounts of protein attached to the surface before and after elution with sodium dodecyl sulfate (SDS) were quantified from single and complex multi-protein solutions to determine protein stability and competitive binding. The PDA coatings were the most stable and capable of immobilizing the highest levels of all proteins. Furthermore, combinations of PDA coatings with the smallest micropatterns provided an additional improvement, enhancing the amount immobilized and the stability. The adsorption of BSA and Fg from plasma demonstrated competitive binding and possible orientation changes, respectively. It was determined that Fet-A, a less studied protein, adsorbed from plasma at low levels, but the adsorption from fetal bovine serum (FBS) was significantly greater, providing important quantification data from radiolabeling that is relevant to many cell culture studies. Overall, combining topography and PDA modification has a synergistic effect on improving protein immobilization. These findings provide new insight on the quantities of proteins bound to PDMS and PDA coatings with implications for cell interactions in various biotechnology and medical applications.

Size Matters? A Comprehensive In Vitro Study of the Impact of Particle Size on the Toxicity of ZnO.

This study describes a comparative in vitro study of the toxicity behavior of zinc oxide (ZnO) nanoparticles and micro-sized particles. The study aimed to understand the impact of particle size on ZnO toxicity by characterizing the particles in different media, including cell culture media, human plasma, and protein solutions (bovine serum albumin and fibrinogen). The particles and their interactions with proteins were characterized in the study using a variety of methods, including atomic force microscopy (AFM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Hemolytic activity, coagulation time, and cell viability assays were used to assess ZnO toxicity. The results highlight the complex interactions between ZnO NPs and biological systems, including their aggregation behavior, hemolytic activity, protein corona formation, coagulation effects, and cytotoxicity. Additionally, the study indicates that ZnO nanoparticles are not more toxic than micro-sized particles, and the 50 nm particle results were, in general, the least toxic. Furthermore, the study found that, at low concentrations, no acute toxicity was observed. Overall, this study provides important insights into the toxicity behavior of ZnO particles and highlights that no direct relationship between nanometer size and toxicity can be directly attributed.

Toward Protein-Repellent Surface Coatings from Catechol-Containing Cationic Poly(2-ethyl-2-oxazoline)

Inspired by mussel proteins that enable surface binding in harsh marine environments, we envisioned a platform of protein-repellent macromolecules based on poly(2-ethyl-2-oxazoline) carrying catechol and cationic functional groups. To facilitate surface attachment, catechol units were installed by copolymerizing a functional comonomer, i.e., 2-(3,4-dimethoxyphenyl)-2-oxazoline, in a gradient fashion. Cationic units were introduced by partial acidic hydrolysis. The surface affinity of these polymers was probed using a quartz crystal microbalance with dissipation monitoring (QCM-D), and it was found that polymers with catechol units had a strong tendency to form surface-bound layers on different substrates, i.e., gold, iron, borosilicate, and polystyrene. While the neutral catechol-containing polymers showed strong, but uncontrolled binding, the ones with additional cationic units were able to form defined and durable polymer films. These coatings were able to prevent the attachment of different model proteins, i.e., bovine serum albumin (BSA), fibrinogen (FI), or lysozyme (LYZ). The herein-introduced platform offers straightforward access to nonfouling surface coatings using a biomimetic approach.

Implant surface physicochemistry affects keratinocyte hemidesmosome formation.

Previous studies have shown hydrophilic/hydrophobic implant surfaces stimulate/hinder osseointegration. An analogous concept was applied here using common biological functional groups on a model surface to promote oral keratinocytes (OKs) proliferation and hemidesmosomes (HD) to extend implant lifespans through increased soft tissue attachment. However, it is unclear what physicochemistry stimulates HDs. Thus, common biological functional groups (NH2 , OH, and CH3 ) were functionalized on glass using silanization. Non-functionalized plasma-cleaned glass and H silanization were controls. Surface modifications were confirmed with X-ray photoelectron spectroscopy and water contact angle. The amount of bovine serum albumin (BSA) and fibrinogen, and BSA thickness, were assessed to understand how adsorbed protein properties were influenced by physicochemistry and may influence HDs. OKs proliferation was measured, and HDs were quantified with immunofluorescence for collagen XVII and integrin β4. Plasma-cleaned surfaces were the most hydrophilic group overall, while CH3 was the most hydrophobic and OH was the most hydrophilic among functionalized groups. Modification with the OH chemical group showed the highest OKs proliferation and HD expression. The OKs response on OH surfaces appeared to not correlate to the amount or thickness of adsorbed model proteins. These results reveal relevant surface physicochemical features to favor HDs and improve implant soft tissue attachment.

Probing the Protein Corona of Nanoparticles in a Fluid Flow by Single-Particle Differenced Resonance Light Scattering Correlation Spectroscopy.

The protein corona of nanoparticles (NPs) plays a crucial role in determining NPs' biological fates. Here, a novel measurement strategy was proposed to in situ investigate the protein corona formed in the NPs with the home-built dual-wavelength laser-irradiated differenced resonance light scattering correlation spectroscopy (D-RLSCS) technique, combined with the modified generation method of the D-RLSCS curve. With the measurement strategy, the dissociation constants and the binding rates between proteins and gold nanoparticles (GNPs) were determined based on the binding-induced ratiometric diffusion change of NPs (the ratio of characteristic rotational diffusion time to translational one), using the formation of the protein corona of bovine serum albumin (BSA) or fibrinogen (FIB) on gold nanoparticles as a model. It was found that BSA shows a stronger binding constant and faster binding rate to gold nanospheres (GNSs) compared with those of FIB. Meanwhile, the dynamic behavior of the protein corona in a fluid flow mimicking biological vessels was further studied based on the combination of the D-RLSCS technique with a microfluidic channel. The measurement results indicated that some "loose" protein corona layers would strip off the surface of NPs within the microchannel due to the fluid sheath force. This method can provide the comprehensive information of a protein corona by averaging the diffusion behavior of many particles different from some conventional methods and overcome the shortcomings of conventional correlation spectroscopy methods.

Proteins at polysaccharide-based biointerfaces: A comparative study of QCM-D and electrokinetic measurements

Controlling protein adsorption on biomaterial surfaces requires a thorough understanding of interfacial phenomena. Proteins adhering after implantation influence successful biointegration. Deciphering adsorption mechanisms at biointerfaces is crucial and of high interest. Here, a combination of time-resolved in situ electrokinetic measurements and quartz crystal microbalance with dissipation monitoring (QCM-D) was employed to understand the adsorption phenomena of blood proteins at thin layers of polysaccharide-based biointerfaces. Adsorption kinetics of bovine serum albumin (BSA), fibrinogen (Fg), and γ-globulin (γG) was studied on polydimethylsiloxane (PDMS) coatings functionalised with chitosan-surfactant complex and hyaluronic acid. The functionalised surfaces show a suppressed protein affinity compared to hydrophobic PDMS. Fg exhibits peculiar adsorption behaviour on PDMS, stemming from the highly oriented end-on adsorption with freely moving α chains. BSA demonstrates arbitrary surface orientation, while γG shows preferential surface orientation on PDMS, exposing a higher density of cationic moieties. The combination of the mentioned techniques proved beneficial for the investigation of interactions, orientations, and changes at biointerfaces in real-time. The approach is versatile and promising where research on surfaces and interfaces is in high demand.

Proactive Hemocompatibility Platform Initiated by PAMAM Dendrimer Adapting to Key Components in Coagulation System.

Surface modification manipulates the application performance of materials, and thrombosis caused by material contact is a key risk factor of biomaterials failure in blood-contacting/implanting devices. Therefore, building a safe and effective hemocompatibility platform is still urgent. Owing to the unique properties of polyamidoamine (PAMAM) dendrimers, in this study, modified surfaces with varying dendrimer densities were interacted with elements maintaining blood homeostasis. These included the plasma proteins bovine serum albumin and fibrinogen, cells in blood (platelets and erythrocyte), as well as endothelial cells (ECs), and the objective was to evaluate the blood compatibility of the chosen materials. Whole blood test and dynamic blood circulation experiment by the arteriovenous shunt mode of rabbit were also conducted, based on the complexity and fluidity of blood. The PAMAM-modified substrates, particularly that with a high density of PAMAM (N1.0), adsorbed proteins with lessened fibrinogen adsorption, reduced platelet activation and aggregation, and suppressed clotting in whole blood and dynamic blood testing. Furthermore, the designed PAMAM dendrimer densities were safe and showed negligible erythrocyte lysis. Concurrently, PAMAM modification could maintain EC growth and did not trigger the release of procoagulant factors. These results suggest that the PAMAM-modified materials are compatible for maintaining blood homeostasis. Thus, PAMAM dendrimers can work as excellent surface modifiers for constructing a hemocompatibility platform and even a primer layer for desired functional design, promoting the service performance of blood-contacting devices.

Tailor-Made Protein Corona Formation on Polystyrene Microparticles and its Effect on Epithelial Cell Uptake.

Microplastic particles are pollutants in the environment with a potential impact on ecology and human health. As soon as microplastic particles get in contact with complex (biological) environments, they will be covered by an eco- and/or protein corona. In this contribution, protein corona formation was conducted under defined laboratory conditions on polystyrene (PS) microparticles to investigate the influence on surface properties, protein corona evolution, particle-cell interactions, and uptake in two murine epithelial cells. To direct protein corona formation, PS particles were preincubated with five model proteins, namely, bovine serum albumin (BSA), myoglobin, β-lactoglobulin, lysozyme, and fibrinogen. Subsequently, the single-protein-coated particles were incubated in a cell culture medium containing a cocktail of serum proteins to analyze changes in the protein corona profile as well as in the binding kinetics of the model proteins. Therein, we could show that the precoating step has a critical impact on the final composition of the protein corona. Yet, since proteins building the primary corona were still detectable after additional incubations in a protein-containing medium, backtracking of the particle's history is possible. Interestingly, whereas the precoating history significantly disturbs particle-cell interactions (PCIs), the cellular response (i.e., metabolic activity, MTT assay) stays unaffected. Of note, lysozyme precoating revealed one of the highest rates in PCI for both epithelial cell lines. Taken together, we could show that particle history has a significant impact on protein corona formation and subsequently on the interaction of particles with murine intestinal epithelial-like cells. However, as this study was limited to one cell type, further work is needed to assess if these observations can be generalized to other cell types.

Mineralized Enzyme-Based Biomaterials with Superior Bioactivities for Bone Regeneration.

The formation and metabolic balance of bone tissue is a controllable process of biomineralization, which is regulated by various cells, biomolecules, and ions. Enzyme molecules play an important role in this process, and alkaline phosphatase (ALP) is one of the most critical factors. In this study, inspired by the process of bone biomineralization, a biomimetic strategy is achieved for the preparation of mineralized ALP nanoparticles (MALPNs), by taking advantages of the unique reaction between ALP and calcium ions in Dulbecco's modified Eagle's medium. Benefiting from the mild biomineralization reaction, the MALPN system highly maintains the activity of ALP. Furthermore, the in vitro studies show that the MALPN system significantly enhances the proliferation of bone marrow mesenchymal stem cells and upregulates their osteogenic differentiation. When evaluated as synthetic graft materials for bone regeneration, the MALPN-incorporated gelatin methacryloyl graft shows excellent mechanical properties, a sustained release profile of ALP, and high biocompatibility and efficacy in guiding bone regeneration and vascularization for critical-sized rat calvarial defect. Moreover, we also demonstrate that the biomimetic mineralization strategy can be adopted for other proteins such as acid phosphatase, bovine serum albumin, fibrinogen, and gelatin, suggesting its universality for constructing mineralized protein-/enzyme-based bioactive materials for the application of tissue regeneration.

Fading of nanocurcumin-based configured biosensor array for differentiation of carrier proteins in biological fluids

Herein, a simple, novel, and cost-effective biosensor array is developed for the differentiation of carrier proteins (i.e. human serum albumin (HSA), bovine serum albumin (BSA), transferrin (TRF), immunoglobulin G (IgG), fibrinogen (Fb) and casein (Cas) based on fading nanocurcumin in alkaline solutions. We found that the carrier proteins show different inhibitory effects with diverse extents on the alkaline decomposition of nanocurcumin. In the other words, in the presence of carrier proteins, the biosensor array produces fingerprint-like absorbance patterns to identify each carrier protein. The absorbance patterns of this biosensor array can be analyzed by linear discrimination analysis (LDA) and hierarchical cluster analysis (HCA). The six carrier proteins have been well discriminated in different concentrations levels. Furthermore, complex mixtures of HSA and TRF with a total concentration of 25 µM and different mole ratios are also discriminated without errors. Also, the HSA as an example of carrier proteins has been well determined in the range of 5–75 µM. The results revealed that the biosensor array shows high selectivity to the carrier proteins in the presence of other interfering substances. The analytical performance of the biosensor array is examined by the differentiation of carrier proteins in human urine and serum biofluids. It should be noted that the biosensor array is very simple, label-free, and selective, and only restricted sensor elements are required for attaining a high differentiation capability of carrier proteins.

A hydrophobic antifouling surface coating on bioprosthetic heart valves for enhanced antithrombogenicity.

Thrombosis is an important factor that causes the failure of artificial biological valves in addition to calcification and immune rejection. A hydrophobic antifouling surface can improve blood compatibility by reducing the absorption of protein. In this study, porcine pericardium was cross-linked with glycidyl methacrylate, and carbon-carbon double bonds were introduced. Then, fluoride monomer was added so that the pericardial surface would become hydrophobic and antifouling. Fluoride modification changed the hydrophilicity of the pericardium surface, and the surface water contact angle increased from 84° to 143°. Compared with unmodified pericardium, the adsorption of bovine serum albumin and fibrinogen decreased by 93.1% and 85%, respectively, and the anti-thrombogenicity was greatly enhanced.

Effect of interface-active proteins on the salt crystal size in waterborne hybrid materials

Aqueous processes yielding hybrid or composite materials are widespread in natural environments and their control is fundamental for a multiplicity of living organisms. Their design and in vitro engineering require knowledge about the spatiotemporal evolution of the interactions between the involved liquid and solid phases and, especially, the interphases governing the development of adhesion during solidification. The present study illustrates the effects of distinct proteins on the precipitation of sodium chloride encompassing the size, shape and distribution of halite crystals formed during the drying of droplets containing equally concentrated saline protein solutions. The precipitates obtained from aqueous sodium chloride formulations buffered with tris(hydroxymethyl)aminomethane (Tris) contained either bovine serum albumin (BSA), fibrinogen or collagen and were characterized with respect to their structure and composition using optical and electron microscopy as well as x-ray analysis. The acquired findings highlight that depending on the protein type present during droplet drying the halite deposits predominantly exhibit cubic or polycrystalline dendritic structures. Based on the phenomenological findings, it is suggested that the formation of the interphase between the growing salt phase and the highly viscous saline aqueous jelly phase containing protein governs not only the material transport in the liquid but also the material exchange between the solid and liquid phases.