Strongly Metal-Adhesive and Self-Healing Gelatin@Polydopamine-Based Hydrogels with Long-Term Antioxidant Activity.

Bioinspired adhesives have been increasingly developed, especially towards a biomedical application. Therefore, in this study, dopamine (DA) was oxidized into polydopamine (PDA) in a gelatin mixture via titration with NaIO4 as a strong oxidant to easily obtain an adhesive antioxidant and self-healing PDA-gelatin hydrogel. Rheology experiments show a stiffness in the order of kPa and a thermal resistance above 50 °C, much above the gel-sol transition temperature of pristine gelatin. After heating at 55 °C, the gel is self-healing. In addition, just after formulation, it shows strong peeling-rate-dependent adhesion to steel with a tensile work per unit area (W) of up to 100 ± 39 J/m2, which is 2.5 times higher than that of the same gel without PDA at a peeling rate of 1000 µm/s. The increase in W between peeling rates of 10 and 1000 µm/s was studied and interpreted in terms of the gels' viscoelasticity. Moreover, this hydrogel offers significant antioxidant activity (measured by DPPH scavenging) that lasts with storage for at least over 15 days, this being then prolonged for 2 additional days, which seems particularly relevant considering the importance of reactive oxygen species (ROS) in wound healing. To summarize, PDA-gelatin gel is a promising strong and antioxidant adhesive.

Percutaneous coronary intervention vs. coronary artery bypass grafting in emergency and non-emergency unprotected left-main revascularization.

BACKGROUND: The optimal revascularization strategy in patients with left main coronary artery (LMCA) disease in the emergency setting is still controversial. Thus, we aimed to compare the outcomes of percutaneous coronary interventions (PCI) vs. coronary artery bypass grafting (CABG) in patients with and without emergent LMCA disease. METHODS: This retrospective cohort study included 2138 patients recruited from 14 centers between 2015 and 2019. We compared patients with emergent LMCA revascularization who underwent PCI (n = 264) to patients who underwent CABG (n = 196) and patients with non-emergent LMCA revascularization with PCI (n = 958) to those who underwent CABG (n = 720). The study outcomes were in-hospital and follow-up all-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE). RESULTS: Emergency PCI patients were older and had a significantly higher prevalence of chronic kidney disease, lower ejection fraction, and higher EuroSCORE than CABG patients. CABG patients had significantly higher SYNTAX scores, multivessel disease, and ostial lesions. In patients presenting with arrest, PCI had significantly lower MACCE (P = 0.017) and in-hospital mortality (P = 0.016) than CABG. In non-emergent revascularization, PCI was associated with lower MACCE in patients with low (P = 0.015) and intermediate (P < 0.001) EuroSCORE. PCI was associated with lower MACCE in patients with low (P = 0.002) and intermediate (P = 0.008) SYNTAX scores. In non-emergent revascularization, PCI was associated with reduced hospital mortality in patients with intermediate (P = 0.001) and high (P = 0.002) EuroSCORE compared to CABG. PCI was associated with lower hospital mortality in patients with low (P = 0.031) and intermediate (P = 0.001) SYNTAX scores. At a median follow-up time of 20 months (IQR: 10-37), emergency PCI had lower MACCE compared to CABG [HR: 0.30 (95% CI 0.14-0.66), P < 0.003], with no significant difference in all-cause mortality between emergency PCI and CABG [HR: 1.18 (95% CI 0.23-6.08), P = 0.845]. CONCLUSIONS: PCI could be advantageous over CABG in revascularizing LMCA disease in emergencies. PCI could be preferred for revascularization of non-emergent LMCA in patients with intermediate EuroSCORE and low and intermediate SYNTAX scores.

Physical Chemistry Study of Collagen-Based Multilayer Films.

The surface properties of a biomaterial play an important role in cell behavior, e.g., recolonization, proliferation, and migration. Collagen is known to favor wound healing. In this study, collagen (COL)-based layer-by-layer (LbL) films were built using different macromolecules as a partner, i.e., tannic acid (TA), a natural polyphenol known to establish hydrogen bonds with protein, heparin (HEP), an anionic polysaccharide, and poly(sodium 4-styrene sulfonate) (PSS), an anionic synthetic polyelectrolyte. To cover the whole surface of the substrate with a minimal number of deposition steps, several parameters of the film buildup were optimized, such as the pH value of the solutions, the dipping time, and the salt (sodium chloride) concentration. The morphology of the films was characterized by atomic force microscopy. Built at an acidic pH, the stability of COL-based LbL films was studied when in contact with a physiological medium as well as the TA release from COL/TA films. In contrast to COL/PSS and COL/HEP LbL films, COL/TA films showed a good proliferation of human fibroblasts. These results validate the choice of TA and COL as components of LbL films for biomedical coatings.

Crosslinking of Bovine Gelatin Gels by Genipin Revisited Using Ferrule-Top Micro-Indentation.

(1) Background: Gelatin is widely used in food science, bioengineering, and as a sealant. However, for most of those applications, the mechanical properties of gelatin gels need to be improved by means of physical or chemical crosslinking. Among the used chemical agents, genipin allows low cytotoxicity in addition to improved Young's modulus. However, the mechanical properties of gelatin-genipin gels have only been investigated at the macroscale, and there is no knowledge of the influence of the genipin concentration on the surface homogeneity of Young's modulus. (2) Methods: To this aim, the influence of genipin concentration on Young's modulus of gelatin gels was investigated by means of ferrule-top micro-indentation. The data were compared with storage moduli obtained by shear rheology data. (3) Results: Ferrule-top indentation measurements allowed us to show that Young's moduli of gelatin-genipin gels increase up to a plateau value after approximately 12 mg/mL in genipin and 4 h of crosslinking. Young's moduli distribute with high homogeneity over 80 µm × 80 µm surface areas and are consistent with the storage moduli obtained by shear rheology. (4) Conclusions: It has been shown that ferrule-top indentation data fitted with the Hertz model yield Young's moduli of gelatin-genipin gels which are consistent with the storage moduli obtained by characterization at the macroscale using shear rheometry. In addition, Young's moduli are homogenously distributed (with some irregularities at the highest genipin concentrations) and can be increased by two orders of magnitude with respect to the uncrosslinked gel.

Experimental Methods to Get Polydopamine Films: A Comparative Review on the Synthesis Methods, the Films' Composition and Properties.

In 2007, polydopamine (PDA) films were shown to be formed spontaneously on the surface of all known classes of materials by simply dipping those substrates in an aerated dopamine solution at pH = 8.5 in the presence of Tris(hydroxymethyl) amino methane buffer. This universal deposition method has raised a burst of interest in surface science, owing not only to the universality of this water based one pot deposition method but also to the ease of secondary modifications. Since then, PDA films and particles are shown to have applications in energy conversion, water remediation systems, and last but not least in bioscience. The deposition of PDA films from aerated dopamine solutions is however a slow and inefficient process at ambient temperature with most of the formed material being lost as a precipitate. This incited to explore the possibility to get PDA and related films based on other catecholamines, using other oxidants than dissolved oxygen and other deposition methods. Those alternatives to get PDA and related films are reviewed and compared in this paper. It will appear that many more investigations are required to get better insights in the relationships between the preparation method of PDA and the properties of the obtained coatings.

Fluorescent bioinspired albumin/polydopamine nanoparticles and their interactions with Escherichia coli cells.

Inspired by the eumelanin aggregates in human skin, polydopamine nanoparticles (PDA NPs) are promising nanovectors for biomedical applications, especially because of their biocompatibility. We synthesized and characterized fluorescent PDA NPs of 10-25 nm diameter based on a protein containing a lysine-glutamate diad (bovine serum albumin, BSA) and determined whether they can penetrate and accumulate in bacterial cells to serve as a marker or drug nanocarrier. Three fluorescent PDA NPs were designed to allow for tracking in three different wavelength ranges by oxidizing BSA/PDA NPs (Ox-BSA/PDA NPs) or labelling with fluorescein 5-isothiocyanate (FITC-BSA/PDA NPs) or rhodamine B isothiocyanate (RhBITC-BSA/PDA NPs). FITC-BSA/PDA NPs and RhBITC-BSA/PDA NPs penetrated and accumulated in both cell wall and inner compartments of Escherichia coli (E. coli) cells. The fluorescence signals were diffuse or displayed aggregate-like patterns with both labelled NPs and free dyes. RhBITC-BSA/PDA NPs led to the most intense fluorescence in cells. Penetration and accumulation of NPs was not accompanied by a bactericidal or inhibitory effect of growth as demonstrated with the Gram-negative E. coli species and confirmed with a Gram-positive bacterial species (Staphylococcus aureus). Altogether, these results allow us to envisage the use of labelled BSA/PDA NPs to track bacteria and carry drugs in the core of bacterial cells.

Escherichia coli Biofilm Formation, Motion and Protein Patterns on Hyaluronic Acid and Polydimethylsiloxane Depend on Surface Stiffness.

The surface stiffness of the microenvironment is a mechanical signal regulating biofilm growth without the risks associated with the use of bioactive agents. However, the mechanisms determining the expansion or prevention of biofilm growth on soft and stiff substrates are largely unknown. To answer this question, we used PDMS (polydimethylsiloxane, 9-574 kPa) and HA (hyaluronic acid gels, 44 Pa-2 kPa) differing in their hydration. We showed that the softest HA inhibited Escherichia coli biofilm growth, while the stiffest PDMS activated it. The bacterial mechanical environment significantly regulated the MscS mechanosensitive channel in higher abundance on the least colonized HA-44Pa, while Type-1 pili (FimA) showed regulation in higher abundance on the most colonized PDMS-9kPa. Type-1 pili regulated the free motion (the capacity of bacteria to move far from their initial position) necessary for biofilm growth independent of the substrate surface stiffness. In contrast, the total length travelled by the bacteria (diffusion coefficient) varied positively with the surface stiffness but not with the biofilm growth. The softest, hydrated HA, the least colonized surface, revealed the least diffusive and the least free-moving bacteria. Finally, this shows that customizing the surface elasticity and hydration, together, is an efficient means of affecting the bacteria's mobility and attachment to the surface and thus designing biomedical surfaces to prevent biofilm growth.

Formulation and rheological evaluation of liposomes-loaded carbopol hydrogels based on thermal waters.

The aims of this study were to develop topical liposomal hydrogels based on thermal waters (TWs) acquired in the region of Biskra (Northeast Algeria) and also to investigate their rheological properties. Liposomes containing two highly mineralized thermal waters, Baraka (BTW) and Salhine (STW), were prepared by probe sonication using phosphatidylcholine (PC) and cholesterol (Chol), plain or mixed with phosphatidylglycerol (PG). Based on their lipid composition, obtained liposomes presented vesicle sizes of 60 nm, a low polydispersity index, and various negative zeta potentials. It was noted that with increasing counterions charge in TWs the zeta potential of liposomes decreased toward neutral values.Carbopol (1%, w/w) hydrogels prepared with BTW, STW, and also demineralized water (placebo hydrogel) showed a non-Newtonian behavior, pseudoplastic fluid adjusted to Carreau model. The composition of thermal waters influenced highly the rheological properties of Carbopol hydrogels. Liposomal hydrogels were prepared by dispersing liposomes in hydrogels formulated with the same encapsulated thermal water. Regardless of composition or lipid concentration of added liposomes, the viscosity and viscoelastic parameters of Carbopol hydrogels changed negligibly. Indeed, liposome composition and lipid concentration seemed to have no effect on the rheological properties of Carbopol hydrogel in the presence of an important charge of cations. Hence, hydrogels and liposomal hydrogels based on thermal waters had suitable rheological properties for topical application and delivery of minerals in the skin.

Adhesion of Resin to Lithium Disilicate with Different Surface Treatments before and after Salivary Contamination-An In-Vitro Study.

The salivary contamination occurring at the try-in procedures of lithium disilicate (LDS) can jeopardize their bond strength. Various laboratory reports have concluded that applying 37% phosphoric acid (H3PO4) could be considered as a predictable way of removing salivary contaminants. An experimental method that consists of sealing the intaglio of the ceramic restorations with a layer of cured adhesive could allow consequent time saving for dental practitioners. It is, besides, necessary to establish an optimal decontamination protocol. Hence, this study aimed to determine the most efficient surface treatment, before and after salivary contamination, by comparing the adhesion between resin and LDS. In order to do so, five groups of ten specimens (n = 10) each underwent the different types of surface treatments before bonding, followed by 2500 cycles in the thermocycler. A shear bond strength (SBS) test was then conducted on a universal testing machine (YLE GmbH Waldstraße Bad König, Germany), followed by a fracture-type analysis on an optical microscope (Olympus BX53, Shinjuku, Tokyo, Japan). Statistical analysis was set with a level of significance of α = 0.05. The surface treatment significantly affected the SBS results. The decontamination with HF (12.59 ± 2.71 MPa) and H3PO4 (13.11 ± 1.03 MPa) obtained the highest values, silanizing only before contamination obtained intermediate values (11.74 ± 3.49 MPa), and silanizing both before and after the salivary contamination (10.41 ± 2.75 MPa) along with applying a bonding agent before contamination (9.65 ± 1.99 MPa) resulted in the lowest values. In conclusion, H3PO4 proved to be efficient, thus, allowing the practitioner to avoid the clinical use of HF; it can, therefore, be considered as a valid alternative. Presilanization and resilanization of specimens, along with applying a bonding agent before contamination, did not yield satisfying results.

Non-covalent small molecule partnership for redox-active films: Beyond polydopamine technology.

HYPOTHESIS: The possibility to use hexamethylenediamine (HMDA) to impart film forming ability to natural polymers including eumelanins and plant polyphenols endowed with biological activity and functional properties has been recently explored with the aim to broaden the potential of polydopamine (PDA)-based films overcoming their inherent limitations. 5,6-dihydroxyindole-2-carboxylic acid, its methyl ester (MeDHICA) and eumelanins thereof were shown to exhibit potent reducing activity. EXPERIMENTS: MeDHICA and HMDA were reacted in aqueous buffer, pH 9.0 in the presence of different substrates to assess the film forming ability. The effect of different reaction parameters (pH, diamine chain length) on film formation was investigated. Voltammetric and AFM /SEM methods were applied for analysis of the film redox activity and morphology. HPLC, MALDI-MS and 1HNMR were used for chemical characterization. The film reducing activity was evaluated in comparison with PDA by chemical assays and using UV stressed human immortalized keratinocytes (HaCat) cells model. FINDINGS: Regular and homogeneous yellowish films were obtained with moderately hydrophobic properties. Film deposition was optimal at pH 9, and specifically induced by HMDA. The film consisted of HMDA and monomeric MeDHICA accompanied by dimers/small oligomers, but no detectable MeDHICA/HMDA covalent conjugation products. Spontaneous assembly of self-organized networks held together mainly by electrostatic interactions of MeDHICA in the anion form and HMDA as the dication is proposed as film deposition mechanism. The film displayed potent reducing properties and exerted significant protective effects from oxidative stress on HaCaT.

Polydopamine at biological interfaces.

In the last years coating of surfaces in the presence of dopamine or other catecholamines in oxidative conditions to yield "polydopamine" films has become a popular, easy and versatile coating methodology. Polydopamine(s) offer(s) also a rich chemistry allowing to post-functionalize the obtained coatings with metal nanoparticles with polymers and proteins. However, the interactions either of covalent or non-covalent nature between polydopamine and biomolecules has only been explored more recently. They allow polydopamine to become a material, in the form of nanoparticles, membranes and other assemblies, in its own right not just as a coating. It is the aim of this review to describe the most recent advances in the design of composites between polydopamine and related eumelanin like materials with biomolecules like proteins, nucleotides, oligosaccharides and lipid assemblies. Furthermore, the interactions between polydopamine and living cells will be also reported.

Optimization of the Elasticity and Adhesion of Catechol- or Dopamine-Loaded Gelatin Gels under Oxidative Conditions.

The synthesis of surgical adhesives is based on the need to design glues that give rise to strong and fast bonds without cytotoxic side effects. A recent trend in surgical adhesives is to use gel-forming polymers modified with catechol groups, which can undergo oxidative crosslinking reactions and are strongly adhesive to all kinds on surfaces in wet conditions. We previously showed that blending gelatin with catechol can yield strong adhesion when the catechol is oxidized by a strong oxidant. Our previous work was limited to the study of the variation in the sodium periodate concentration. In this article, for an in-depth approach to the interactions between the components of the gels, the influence of the gelatin, the sodium periodate and dopamine/(pyro)catechol concentration on the storage (G') and loss (G″) moduli of the gels, as well as their adhesion on steel, have been studied by shear rheometry. The hydrogels were characterized by infrared and UV-Vis spectroscopy and the size of their pores visualized by digital microscopy and SEM after freeze drying but without further additives. In terms of adhesion between two stainless steel plates, the optimum was obtained for a concentration of 10% w/v in gelatin, 10 mM in sodium periodate, and 20 mM in phenolic compounds. Below these values, it is likely that crosslinking has not been maximized and that the oxidizing environment is weakening the gelatin. Above these values, the loss in adhesiveness may result from the disruption of the alpha helixes due to the large number of phenolic compounds as well as the maintenance of an oxidizing environment. Overall, this investigation shows the possibility to design strongly adhesive hydrogels to metal surfaces by blending gelatin with polyphenols in oxidative conditions.

Impacts of Resveratrol and Pyrogallol on Physicochemical, Mechanical and Biological Properties of Epoxy-Resin Sealers.

This study aimed at evaluating the physicochemical and biological properties of experimental epoxy-resin sealers containing polyphenols such as resveratrol and pyrogallol. A conventional epoxy resin (OB) was modified by adding different concentrations of resveratrol (RS) or pyrogallol (PY) to its composition. Antibacterial and antioxidant activities, mechanical properties, along with wettability and morphological changes were investigated. The results were statistically analyzed using ANOVA and multiple comparison tests (α = 0.05). The incorporation of the tested polyphenols into the epoxy resin enhanced its mechanical properties. PY demonstrated much better antioxidant and antibacterial activities than RS, which were associated with a higher release of PY. In contrast, PY showed a higher cytotoxicity than OB and OB doped with RS. OB containing PY presented a rougher surface and higher water absorption than OB doped with RS. Both tested polyphenols caused no notable changes to the overall porosity of OB. Resveratrol and pyrogallol may not only influence the morphology and mechanical properties of epoxy-resin sealers, but could also enhance antioxidant activity and antibacterial effects against Enterococcus faecalis. Most epoxy-resin sealers currently available in the market can be considered as "passive" materials. Thus, doping their composition with specific polyphenols may be a suitable strategy to confer some antibacterial properties, antioxidant potential, along with improvement of some mechanical properties.

Dual role of tannic acid and pyrogallol incorporated in plaster of Paris: Morphology modification and release for antimicrobial properties.

The design of bioactive plasters is of major interest for the amelioration of dental and bone cements. In this article, a one pot and environmentally friendly strategy based on the addition of a cheap polyphenol-tannic acid (TA) or the main phenolic constituent of TA, namely pyrogallol (PY)- able to interact with calcium sulfate is proposed. Tannic acid and pyrogallol not only modify the morphology of the obtained plaster+TA/PY composites but a part of it is released and provides strong-up to twenty fold- antibacterial effect against Staphylococcus aureus. It is shown that the higher antibacterial efficiency of PY is related to a greater release compared to TA even if in solution the antibacterial effect of PY is lower than that of TA when reported on the basis of the molar concentration in PY units.

Antibacterial and Bonding Properties of Universal Adhesive Dental Polymers Doped with Pyrogallol.

This study investigated the antibacterial activity, bond strength to dentin (SBS), and ultra-morphology of the polymer-dentin interface of experimental adhesive systems doped with pyrogallol (PY), which is a ubiquitous phenolic moiety that is present in flavonoids and polyphenols. A universal adhesive containing 4-META and 10-MDP was used in this study. PY behaves as an antioxidant and anti-cancerogenic agent and it was incorporated into the adhesive at different concentrations (0.5 and 1 wt.%). The antibacterial activity and SBS were analyzed and the results were statistically analyzed. The ultra-morphology of the polymer-dentin interface was assessed using scanning electron microscopy (SEM). At 24 h, a lower antibacterial activity was observed for the control adhesive compared to those with 0.5% and 1% PY. No difference was seen in SBS between the three groups at 24 h. After 6 months, the SBS of the 0.5% PY adhesive was significantly lower than the other tested adhesives. The specimens created with 1% PY adhesive presented a higher bond strength at six months compared with that found at 24 h. No morphological differences were found at the polymer-dentin interfaces of the tested adhesives. Pyrogallol may be incorporated into modern universal adhesive systems to preserve the polymer-dentin bonding interface and confer a certain degree of antibacterial activity.

Insensitivity of dental pulp stem cells migration to substrate stiffness.

Dental pulp stem cells (DPSCs) are a promising cell source for regeneration of dental pulp. Migration is a key event but influence of the microenvironment rigidity (5 kPa at the center of dental pulp to 20 GPa for the dentin) is largely unknown. Mechanical signals are transmitted from the extracellular matrix to the cytoskeleton, to the nuclei, and to the chromatin, potentially regulating gene expression. To identify the microenvironmental influence on migration, we analyzed motility on PDMS substrates with stiffness increasing from 1.5 kPa up to 2.5 MPa. We found that migration speed slightly increases as substrate stiffness decreases in correlation with decreasing focal adhesion size. Motility is relatively insensitive to substrate stiffness, even on a bi-rigidity PDMS substrate where DPSCs migrate without preferential direction. Migration is independent of both myosin II activity and YAP translocation after myosin II inhibition. Additionally, inhibition of Arp2/3 complex leads to significant speed decrease for all rigidities, suggesting contribution of the lamellipodia in the migration. Interestingly, the chromatin architecture remains stable after a 7-days exposure on the PDMS substrates for all rigidity. To design scaffold mimicking dental pulp environment, similar DPSCs migration for all rigidity, leaves field open to choose this mechanical parameter.

Tannic acid speeds up the setting of mineral trioxide aggregate cements and improves its surface and bulk properties.

HYPOTHESIS: The setting time and mechanical properties of cements are a major technical concern for a long time in civil engineering. More recently those practical problems became a major concern for biomedical applications -in bone surgery and in dentistry- in particular concerning the setting time which should be minimized. The possibility to add organic additives to interact with the different constituting ions in cements constitutes a way to modify the setting kinetics. We made the assumption that a hydrolysable polyphenol like tannic acid could modify the setting time and the physical properties of Mineral Trioxide Aggregate (MTA). EXPERIMENTS: Tannic acid is added in variable proportions to the water used to set MTA. The formation of the hybrid organic-mineral cements is investigated using a combination of structural, chemical and mechanical methods. X-ray tomography was also used to investigate the changes in porosity and pore size distribution upon incorporation of tannic acid in MTA based cements. The hydrophilicity of the cements was evaluated by measuring the permeation kinetics of small water droplets. FINDINGS: We found that tannic acid allowed to reduce markedly the setting time of MTA based cements. The obtained cements have an increased hydrophilicity and display excellent resistance to compression. The number of pores but not the average pore size is also affected. The possible roles of tannic acid in modifying the cement properties are discussed.

Clinical Presentation and Outcome of Patients With Spontaneous Coronary Artery Dissection Versus Atherosclerotic Coronary Plaque Dissection.

BACKGROUND: Atherosclerotic coronary plaque dissection (ACPD) is one cause of acute coronary syndrome (ACS) caused by underlying atherosclerosis. Spontaneous coronary artery dissection (SCAD) occurs outside the setting of atherosclerosis among young women and individuals with few or no conventional atherosclerotic risk factors, and has emerged as an important cause of ACS, and sudden death. A comparison between ACPD and SCAD has not been previously addressed in the literature. Our study will compare ACPD and SCAD. METHODS: Patients with confirmed diagnosis of SCAD and ACPD were retrospectively identified from 30 centers in 4 Arab Gulf countries between January 2011 and December 2017. In-hospital (ventricular tachycardia/ventricular fibrillation, myocardial infarction (MI), percutaneous coronary intervention, dissection extension, cardiogenic shock, death, implantable cardioverter-defibrillator placement) and follow-up (MI, de novo SCAD, spontaneous superior mesenteric artery dissection, death) events were compared between them. RESULTS: Eighty-three cases of SCAD and 48 ACPD were compared. ACPD patients were more frequently male (91.67% vs. 49.40%, P < 0.001) and older (58.5 vs. 44, P < 0.001). Cardiovascular risk factors were more prevalent in patients with ACPD, including diabetes mellitus (60.4% vs. 25.3%), dyslipidemia (62.5% vs. 38.5%), and hypertension (62.5% vs. 31.3%), P < 0.001. Hospital presentation of ST-elevation MI was diagnosed in 48% of SCAD versus 27% of ACPD patients (P = 0.012). SCAD patients received medical-only treatment in 40% of cases and ACPD in 21% (P = 0.042). In-hospital and follow-up events were comparable in both groups (P = 0.25). CONCLUSIONS: Despite a completely different pathophysiology of ACS between SCAD and ACPD, in-hospital and follow-up events were comparable.

Correlative Microscopy Insight on Electrodeposited Ultrathin Graphite Oxide Films.

Here, we present a correlative microscopic analysis of electrodeposited films from catechol solutions in aqueous electrolytes. The films were prepared in a miniaturized electrochemical cell and were analyzed by identical location transmission electron microscopy, scanning transmission X-ray microscopy, and atomic force microscopy. Thanks to this combined approach, we have shown that the electrodeposited films are constituted of ultrathin graphite oxide nanosheets. Detailed information about the electronic structure of the films was obtained by X-ray absorption near edge structure spectroscopy. These results show the large potential of soft electrochemical conditions for the bottom-up production of ultrathin graphite oxide nanosheet films via a one-pot green chemistry approach from simple organic building blocks.

Polyarginine Decorated Polydopamine Nanoparticles With Antimicrobial Properties for Functionalization of Hydrogels.

Polydopamine (PDA) nanoparticles are versatile structures that can be stabilized with proteins. In this study, we have demonstrated the feasibility of developing PDA/polypeptides complexes in the shape of nanoparticles. The polypeptide can also render the nanoparticle functional. Herein, we have developed antimicrobial nanoparticles with a narrow size distribution by decorating the polydopamine particles with a chain-length controlled antimicrobial agent Polyarginine (PAR). The obtained particles were 3.9 ± 1.7 nm in diameter and were not cytotoxic at 1:20 dilution and above. PAR-decorated nanoparticles have exhibited a strong antimicrobial activity against S. aureus, one of the most common pathogen involved in implant infections. The minimum inhibitory concentration is 5 times less than the cytotoxicity levels. Then, PAR-decorated nanoparticles have been incorporated into gelatin hydrogels used as a model of tissue engineering scaffolds. These nanoparticles have given hydrogels strong antimicrobial properties without affecting their stability and biocompatibility while improving their mechanical properties (modulus of increased storage). Decorated polydopamine nanoparticles can be a versatile tool for the functionalization of hydrogels in regenerative medicine applications by providing bioactive properties.