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The concentration of CO2 in indoor environments may exceed 800 ppm, making people feel lightheaded and uncomfortable. In response, this study demonstrates how to reduce indoor CO2 concentration using a solid membrane for gas separation and CO2 removal. In this investigation, the solid membrane is made by blending polyvinyl alcohol (PVA) and poly(allylamine) (PAA) solution and coating this material on the surface of a reverse osmosis membrane via a spin coater. The separation layer is formed after drying. This separation layer is modified by hydroxyl and amine functional groups, thereby improving selectivity and effectiveness of CO2 capture. FTIR and SEM were applied to characterize the surface of the reverse osmosis membrane. Testing of the membrane showed that with lower input gas pressure, CO2 gas has a larger gas permeability (GP) value than nitrogen at room temperature. When the pressure is 0.75 cm Hg, 1 wt% PVA + 7 wt% PAA has the greatest CO2/N2 gas selectivity ratio. Under these conditions, the selectivity is 10.7.

Electrochemical alternating current synthesis starting from an ethanol solution of CuSO4 · 5H2O and allylamine in the presence of solid sodium azide results in formation of Cu[C3H5NH2]N3. The trigo...

The increasing resistance of pathogenic bacteria to the pharmaceutical compound could be a very important issue for public health. A sensitive, fast and accurate approaches for bacteria detection are going to be needed to enhance the effectiveness of treatment. This study aimed to develop a colorimetric sensor based on allylamine-conjugated polyacrylic acid and gold nanoparticles (AuNPs- AAm-PAA) for bacteria detection. Allylamine was conjugated to the polyacrylic acid and mixed with the gold colloid to form a self-assembled AuNPs-AAm-PAA. The polymer-modified gold nanoparticles were characterized for the particle size, zeta potential, reversibility using TEM, particle size analyzer, and UV-Vis spectrophotometer, respectively. The system was observed to detect bacteria and observed by the naked eye, UV-Vis spectrophotometer, and TEM. The results showed that AuNPs-PAA-AAm solution showed an absorbance peak at 530 nm, AuNPs particle size of 25.67 nm ± 2.68, and zeta potential -31.4 ± 4.5 mV. Introduction of bacteria into the Au-AAm-PAA solution resulted in a color change from red to purple at concentrations of 6x108 CFU/mL of Staphylococcus aureus and Escherichia coli. TEM analysis revealed the binding of aggregated gold nanoparticles around the outer membrane of bacteria. The sensor system based on conjugated polymer and gold nanoparticles demonstrated a promising way for bacteria detection.

International audience; A rapid photo-curing system based on poly(2-ethyl-2-oxazoline-co-2-allylamidopropyl-2-oxazoline) and its in vivo compatibility are presented. The base polymer was synthesized from the copolymerization of 2-ethyl-2-oxazoline (EtOx) and the methyl ester containing 2-methoxycarboxypropyl-2-oxazoline (C 3 MestOx) followed by amidation with allylamine to yield a highly water-soluble macromer. We showed that spherical hydrogels can be obtained by a simple waterin-oil gelation method using thiol−ene coupling and investigated the in vivo biocompatibility of these hydrogel spheres in a 28-day murine subdermal model. For comparison, hydrogel spheres prepared from poly(ethylene glycol) were also implanted. Both materials displayed mild, yet typical foreign body responses with little signs of fibrosis. This is the first report on the foreign body response of a poly(2-oxazoline) hydrogel, which paves the way for future investigations into how this highly tailorable class of materials can be used for implantable hydrogel devices.

Salicylic acid (SA) is a phenolic phytohormone with critical roles in plant growth regulation and resistance to biotic and abiotic stress. Since low SA concentrations can modulate many plant biochemical responses, innovative analytical tools are required to deeply understand its activity and to control its exogenous application in modern agricultural systems. Herein, a NIR-activated composite based on NaYF

Focused ultrasound (FU) is in demand for clinical cancer therapy, but the possible thermal injury to the normal peripheral tissues limits the usage of the ablative FU for tumors with a large size; therefore research efforts have been made to minimize the possible side effects induced by the FU treatment. Non-ablative focused ultrasound assisted chemotherapy could open a new avenue for the development of cancer therapy technology. Here, low intensity focused ultrasound (LIFU) for controlled quick intracellular release of small molecules (Mw ≤ 1000 Da) without acute cell damage is demonstrated. The release is achieved by a composite poly(allylamine hydrochloride) (PAH)/poly-(sodium 4-styrenesulfonate) (PSS)/SiO2 microcapsules which are highly sensitive to LIFU and can be effectively broken by weak cavitation effects. Most PAH/PSS/SiO2 capsules in B50 rat neuronal cells can be ruptured and release rhodamine B (Rh-B) into the cytosol within only 30 s of 0.75 W cm-2 LIFU treatment, as demonstrated by the CLSM results. While the same LIFU treatment shows no obvious damage to cells, as proved by the live/dead experiment, showing that 90% of cells remain alive.

Modification of boron-doped diamond (BDD) with gold-palladium nanoparticles (Au@PdNPs) was successfully performed. Prior to the modification, BDD was modified with allylamine to provide active sites for the attachment of nanoparticles, while the synthesis of Au@PdNPs was performed by chemical reduction of a palladium salt solution in a colloidal solution of gold nanoparticles. Characterization using TEM images showed that by controlling the palladium concentration, flower and core-shell shaped Au@PdNPs can be prepared. XPS studies confirmed that the nanoparticles with a flower shape could be attached better on the BDD surface. The Au@PdNPs-modified BDD (Au@PdNPs-BDD) electrodes were then examined for the oxygen reduction reaction in comparison with gold and palladium-based electrodes. One order higher current response was observed at Au@PdNPs-BDD compared to AuNPs-BDD, indicating the contribution of palladium in the oxygen reduction reaction. Good linearity with comparable limits of detection suggested that Au@PdNPs-BDD electrodes are promising for use as oxygen sensors. Furthermore, their application as BOD sensors was demonstrated.

A series of hydrophobic/hydrophilic well-defined stereoregular cyclic structures–p-tolyl-siloxanes with alkyl, O- and N-containing groups–were obtained as promising reagents for the synthesis of functionalized derivatives. This approach is based on the preparation of a stereoregular cyclic p-tolyl-siloxane with a Si–H group (1) followed by hydrosilylation of 1-octene, allyl glycol ethers and alcohol or allylamine derivatives (2a–g). The method is well scalable and allows the target products (3a–g) to be obtained on a gram scale (∼10 g) in 60–95% yields. The structure of the compounds was confirmed by a set of physicochemical methods of analysis, namely IR, ESI-HRMS, GPC, 1D and 2D 1H, 13C, and 29Si NMR experiments, and X-Ray diffraction for cyclic p-tolyl- and hydride-containing siloxane (1).

Tinea is a common superficial infection caused by keratinophylic fungi called dermatophytes. The objective of the current investigation was to develop and optimize a self-nanoemulsion drug delivery system (SENDDs) using clove oil loaded with naftifine (NF). Clove oil possesses good anti-inflammatory and antifungal properties that can support naftifine action. Box–Behnken designs were used to prepare plain and naftifine loaded SENDDs. The plain SENDDs were evaluated for their globule size. The medicated formulations (NF-CO-SENDDs) were characterized by measuring their globular size, ex vivo % NF permeated, level of interleukin-31 in rats, and antifungal activity. The optimum clove oil level was found to be 10–17%, while NF-CO-SENDDs formulations displayed globular sizes ranging from 119 to 310 nm. The statistical design confirmed the synergistic effect of clove oil and NF in the treatment of fungal infections, confirming that the anti-inflammatory effect of clove oil can counteract the side effects of NF. The optimized formulation composed of 14% clove oil, 12.5 mg Naftifine, and prepared with an Smix ratio equaling 3:1, exhibited good antifungal and anti-inflammatory activity, achieving up to 2-, 3-, 5.75-, and 2.74-fold increases in the amount of permeated NF, steady-state flux, permeability, and diffusion coefficients, respectively, compared with a commercial product. Moreover, the optimum formulation revealed an adequate zeta potential value of 28.31 ± 1.37 mV and showed reasonable stability with no or mild signs of skin sensitivity. Therefore, the designed nanoemulsions containing a combination of clove oil and naftifine could be considered promising delivery systems for the treatment of tinea.

Allylamines are versatile building blocks in the synthesis of various naturally occurring products and pharmaceuticals. In contrast to terminal allylamines, the methods of synthesis of their branched congeners with internal, stereodefined double bonds are less explored. This work describes a new approach for the preparation of allylamines via cross-coupling of alkyl bromides with simple 3-bromoallylamines by merging the photoredox approach and Ni catalysis. The reaction proceeds under mild conditions, under blue light irradiation, and in the presence of an organic dye, 4CzIPN, as a photocatalyst. The scope of suitable reaction partners is broad, including alkyl bromides bearing reactive functionalities (e.g., esters, nitriles, aldehydes, ketones, epoxides) and N-protected allylamines, as well as N-allylated secondary and tertiary amines and heterocycles. The employment of non-racemic starting materials allows for rapid and easy construction of complex multifunctional allylamine derivatives without the loss of enantiomeric purity.

Poli(allilamin) çözeltisinin CaA, NaX, NaY ve ZSM-5 zeolitleri üzerindeki adsorpsiyonu FT-IR ve Raman spektroskopileri kullanılarak araştırılmıştır. Bahsedilen zeolitler üzerine adsorbe edilmiş poli(allilamin) titreşim dalgasayıları rapor edilmiş ve farklı katyonlara ve moleküler boyutlara sahip zeolitlerin adsorpsiyon özellikleri karşılaştırılmıştır. Titreşim modları konumundaki düşük veya yüksek frekans bölgelerine kaymalar ya da titreşim bantlarının kaybolması, poli(allilamin) ve zeolitler arasında etkileşimler olduğu anlamına gelir. Elde edilen sonuçları dikkate alarak, bahsedilen zeolitler üzerindeki polimerin adsorpsiyon kaynağının, polimerin amin grubu ile zeolitlerin yüzeyi üzerindeki silanol hidroksil grubu arasındaki etkileşime dayanabileceğini söyleyebiliriz., The adsorptions of poly(allylamine) solution on CaA, NaX, NaY, and ZSM-5 zeolites have been investigated by using FT-IR and micro-Raman spectroscopies. Vibrational wavenumbers of poly(allylamine) adsorbed on the mentioned zeolites have been reported and the adsorption characteristics of zeolites with different cations and molecular sizes have been compared. The small shifts to the high or low-frequency regions in the position of vibration modes or the disappearance of the vibration bands show that there are interactions between poly(allylamine) and zeolites. By considering the obtained results, we can say that the adsorption source of polymer on the mentioned zeolites can withstand the interaction between the amine group of polymer and the silanol hydroxyl group on the surface of the zeolites.

Bis(N-ethylbenzimidazol-2-ylmethyl)allylamine (EtAIDB) and its two complexes, [Mn(EtAIDB)Cl2] (1) and [Zn(EtAIDB)Cl2] (2), have been synthesized and characterized by elemental analyses, molar conductivities, UV–Visible and IR spectra. The crystal structures of both complexes have been determined by X-ray single crystal diffraction. The coordination environment of Mn(II) in 1 is a five-coordinate distorted trigonal bipyramid with a N3Cl2 ligand set, while 2 is a four-coordinate twisted tetrahedral geometry. Structural and Hirshfeld surface analysis reveals that these two complexes are dimers formed by π···π interactions. The antioxidant activity was determined by superoxide methods in vitro, indicating that 1 exhibited potential antioxidant properties.

Palladium-catalyzed organometallic transformations of free amines are often unsuccessful due to side reactions, such as oxidation, that can occur. However, the ability to furnish the free amine products from these reactions is important for improving the utility and sustainability of these processes, especially for accessing their potential as medicinal and agrochemical agents. Notably, the 3,3-diarylallylamine motif is prevalent in a variety of biologically relevant structures, yet there are few catalytic approaches to their synthesis, and none involving the free amine. Herein, we describe a simple protocol for the arylation of cinnamylamines and the diarylation of terminal allylamines to generate a diverse group of 3,3-diarylallylamine products using a PdII precatalyst. Key features of the method are the ability to access relatively mild conditions that facilitate a broad substrate scope as well as direct diarylation of terminal allylamine substrates. In addition, several complex and therapeutically relevant molecules are included to demonstrate the utility of the transformation.

1,4-Naphthoquinone (NQ) undergoes a two electron and two proton redox process in one step at a potential of −0.05 V (vs Ag/AgCl) in 0.05 M H2SO4 aqueous solution. Its heterogeneous electron transfe...

Here, a novel poly(dimethylsiloxane) (PDMS)-based microbial culture system was investigated. Bacteria were encapsulated in functional and semipermeable membranes, mimicking the cell microenvironment and facilitating mass transport for interrogating microbial dynamics, thereby overcoming one of the major challenges associated with commercially available PDMS such as Sylgard 184. The hydrophobic nature and lack of control in the polymer network in Sylgard 184 significantly impede the the tunability of the transport and mechanical properties of the material as well as its usage as an isolation chamber for culturing and delivering microbes. Therefore, a novel PDMS composition was developed and functionalized with dimethylallylamine (DMAA) to alter its hydrophobicity and modify the polymer network. Characterization techniques including NMR spectroscopy, contact angle measurements, and sol-gel process were utilized to evaluate the physical and chemical properties of the newly fabricated membranes. Furthermore, the DMAA-containing polymer mixture was used as a proof of concept to generate hydrodynamically stable microcapsules and cultivate Escherichia coli cells in the functionalized capsules. The membrane exhibited a selective permeability to tetracycline, which diffused into the capsules to inhibit the growth of the encapsulated microbes. The functionality achieved here with the addition of DMAA, coupled with the high-throughput encapsulation technique, could prove to be an effective testing and diagnostic tool to evaluate microbial resistance, growth dynamics, and interspecies interaction and lays the foundation for in vivo models.

© 2020 Wiley-VCH GmbH An electrochemical sensor using glassy carbon electrode modified with carbon black within a poly(allylamine hydrochloride) film is proposed in this work. The novel sensor was characterized by scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry using the redox probe Fe(CN)63−/4−. The sensor was applied for the simultaneous determination of dopamine (DA), paracetamol (PAR), amlodipine (AML), and rosuvastatin (RSV). The quantification of all four analytes was carried out by linear sweep voltammetry and presented a linear concentration range for all analytes from 1.0 to 90 μmol L−1, with limit of detection of 0.55, 1.3, 5.7, and 3.0 μmol L−1 for DA, PAR, AML, and RSV, respectively. This sensor was successfully applied in the simultaneous determination of these analytes in environmental, pharmaceutical, and biological samples.

This article concerns studies of flexible track-etched membrane modification by photograft polymerization of methacrylic acid and subsequent formation of interpolyelectrolyte complexes with poly(allylamine) for enhancement of properties of electrochemical sensor. Optimal conditions leading to functionalization of the surface and maintenance of the pore structure were found. Membranes were characterized by SEM, FTIR, XPS, gas permeability and colorimetric assay. Square wave anodic stripping voltammetry (SW-ASV) was used for detection of Pb2+. Limits of detection (LOD) for sensors based on non-modified PET TeMs, membranes modified by graft polymerization of methacrylic acid (PET TeMs-g-PMAA) and membranes modified with interpolyelectrolyte complexes with poly(allylamine) (PET TeMs-g-PMAA-PAlAm) are 3.03, 2.78 and 1.25 µg/L, respectively. Thus, it was shown that the formation of interpolyelectrolyte complexes on the membranes leads to a more accurate detection of lead ions.

Purpose We aimed to optimize the factors affecting the production of the allylamine antifungal, terbinafine, by Lysinibacillus isolate MK212927, a natural producer of this broad-spectrum fungicidal compound. Methods We employed a central composite design to optimize the five most important variables influencing the production of terbinafine which were carbon source, nitrogen source, temperature, pH and agitation. Results The optimum conditions were found to be starch 5 g/L, ammonium chloride 5 g/L, temperature 32°C, agitation 150 rpm and pH 7. The actual response (inhibition zone diameter) was highly comparable to the value predicted by the model, indicating a valid model. Using the standard calibration curve of terbinafine, the optimized conditions resulted in an increase in the antifungal metabolite production (terbinafine) by about 1.6-fold (1814.662 µg/mL compared to 1165.550 µg/mL under standardized conditions). Conclusion This is the first report, to the best of our knowledge, on optimized production of terbinafine by Lysinibacillus species. Hence, these findings may be useful as baseline data for scaling up the production of terbinafine from a natural microbial source.

Poly(allylamine) graft polymers have been shown to hold potential as drug delivery vehicles and complexation agents for biological molecules such as insulin. The nanoparticles formed upon aggregation or complexation allow for enhanced cellular trafficking resulting in enhanced efficacy. Multiple reports have shown the ease of synthesis and reliability of these graft polymers, however, little investigation into the effect of the molecular weight of the homopolymer poly(allylamine) has been carried out. In this work we synthesized a range of oxadiazole grafted poly(allylamine) derivatives of varied molecular weight (15, 17.5, 120 & 900 kDa) set at a 5% polymer:oxadiazole mole grafting. The effect of molecular weight on the size, critical aggregation concentration and drug loading/release was evaluated in model drugs before loading the optimal formulation with doxorubicin and carrying out a preliminary cytotoxicity study. In line with other cationic polymers, the larger poly(allylamine) amphiphilic derivatives resulted in greater drug loading, however, the particle size increased whilst drug loading dramatically decreased, which for cancer nanomedicine could be a barrier for pharmaceutical use.

Hyperpolarization of N-heterocycles with Signal Amplification by Reversible Exchange (SABRE) induces NMR sensitivity gains for biological molecules. Substitutions with functional groups, in particular in the ortho-position of the heterocycle, however result in low polarization using a typical Ir-catalyst with bis-mesityl N-heterocyclic carbene ligand for SABRE, presumably due to steric hindrance. With the addition of allylamine or acetonitrile as coligands to the precatalyst chloro(1,5-cyclooctadiene)[4,5-dimethyl-1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene] iridium, the 1 H signal enhancement increased in several substrates with ortho NH 2 -substitutions. For example, for a proton in 2,4-diaminopyrimidine, the enhancement factors increased from -7 ± 1 to -210 ± 20 with allylamine or to -160 ± 10 with acetonitrile. CH 3 substituted molecules yielded maximum signal enhancements of -25 ± 7 with acetonitrile addition, which is considerably less than the corresponding NH 2 substituted molecules, despite exhibiting similar steric size. With the more electron-donating NH 2 substitution resulting in greater enhancement, it is concluded that steric hindrance is not the only dominant factor in determining the polarizability of the CH 3 substituted compounds. The addition of allylamine increased the signal enhancement for the 290 Da trimethoprim, a molecule with the 2,4-diaminopyrimidine moiety serving as a widespread antibacterial agent, to -70.

Surface-enhanced Raman scattering (SERS) nanoprobes based on Au@Ag core@shell nanoparticles coated with poly(allylamine) were functionalized with small targeting molecules to evaluate simultaneously the level of expression of two cancer-related markers, both in cells and in tissues. The Au@Ag nanoparticles provide a high SERS signal enhancement in the visible range when combined with resonant Raman-active molecules. The poly(allylamine) coating plays a dual key role in (i) protecting the metal surface against the complex biological medium, leading to a stable signal of the Raman-active molecules, and (ii) enabling specific biofunctionalization through its amine functions. Using small targeting molecules linked to the polymer coating, two different nanoprobes (duplex approach) were designed. Each was able to specifically target a particular cancer-related marker: folate receptors (FRs) and sialic acid (SA). We demonstrate that the level of expression of these targeted markers can be evaluated following the SERS signal of the probes incubated on cells or tissues. The potential overexpression of folate receptors and of sialic acid was evaluated and measured in breast and ovarian cancerous tissue sections. In addition, FR and/or SA overexpression in the tumor region can be visualized with high contrast with respect to the healthy region and with high spatial accuracy consistent with histology by SERS imaging of the nanoprobe signal. Owing to the unique spectral signature of the designed nanoprobes, this approach offers an efficient tool for the spatially resolved, in situ measurement of the expression level of several cancer-related markers in tumors at the same time.Graphical abstract.

Three new metal complexes, namely: [Mn(AIDB)Cl2]·DMF (1), [Zn(AIDB)Br2]·CH3OH (2) and [Co(AIDB)Cl2]·CH3OH (3) having a ligand bis(benzimidazol-2-ylmethyl)allylamine (AIDB), have been synthesized in high yields and characterized by elemental analyses, molar conductivities, IR, UV–Vis spectra and single-crystal X-ray diffraction. The structural analysis revealed that all the three complexes 1–3 have five-coordinated trigonal bipyramid geometry where the degree of distorting is 1>3>2. In vitro antioxidant activity assay demonstrates that the complexes 1 and 3 display high scavenging activity against hydroxyl (OH·) and superoxide (O2−·) radicals.

This paper reports a method for preparation of functional derivative – poly(N-2-sulfoethyl)allylamine – obtained when treating poly(allylamine) with sodium vinylsulfonate, and allowing for the comp...

Development of oral phosphorus binding agent with desirable biocompatibility and stability is full of significance in the treatment of chronic kidney disease. In this study, a natural product, cellulose, was selected as the substrate agent in which the –OH groups are able to chelate with Ce(IV) to generate the radicals and thereby initiate the surface grafting polymerization. Following this way, allylamine-grafted cellulose was prepared (ALE-CLS) under mild environment with high grafting ratio (160.2%) and desirable phosphorus binding capacities (23.3 mg/g). The phosphorus binding capacity increases with the rise of grafting ratio. The degradation tests give the result that the product possesses a good stability in acid environment and oxidation environment, suggesting a good stability in gastrointestinal tract. The in vivo experiment is also conducted to reveal the effect on reducing the serum phosphate levels in healthy rats and rats with hyperphosphatemia. The prepared ALE-CLS shows a much lower swelling ratio than that of RenaGel® (0.25 vs 3.69), which may serve as a good candidate as oral phosphorus binding agent with less gastrointestinal discomfort.

In the present work, allylamine exfoliated alpha zirconium phosphate (AXZrP) reinforced unsaturated polyester (UP) nanocomposites were developed and characterized. Exfoliation of alpha zirconium phosphate (α-ZrP) was achieved through Bronsted acid–base interaction using allylamine in different mole ratios. The partially exfoliated α-ZrP possesses a higher concentration of α-ZrP than completely exfoliated. Subsequently, the partially exfoliated α-ZrP was reinforced with UP resin to enhance the thermal and mechanical properties of the resulting composite. Detailed studies using scanning electron microscopic and X-ray diffraction analysis suggest that the AXZrP/UP composite possesses a homogeneous distribution of α-ZrP within the UP matrices. For 10.0 wt% AXZrP/UP composite, the mechanical properties such as tensile and flexural strength were observed to enhance up to 56% and 61% respectively. Further, appreciable enhancement in the flame retardant behavior with V0 rating and high thermal stability with LOI value of 27.1% for 10.0 wt% AXZrP/UP composite was observed. Similarly, the catalytic effect of α-ZrP contributes to enhancing the flame retardant behavior along with rapid char formation.

The current research was accomplished to study the application of graphene oxide functionalised with cyanuric chloride and allylamine (GO/Fe3O4/CC/AA) for the removal of pyrene from tap water, rive...

Preventing bacterial attachment to surfaces is the most efficient approach to controlling biofilm proliferation. The aim of this study was to compare anti-adhesion potentials of 5 and 50 mmol/L polyelectrolyte multilayers of poly(allylamine hydrochloride)/poly(sodium 4–styrenesulfonate), poly(4-vinyl-N-ethylpyridinium bromide)/ poly(sodium 4–styrenesulfonate), and poly(4-vinyl-N-isobutylpyridinium bromide)/poly(sodium 4–styrenesulfonate) against Escherichia coli. Glass surface was covered with five polyelectrolyte layers and exposed to bacterial suspensions. Poly(4-vinyl-N-ethylpyridinium bromide)/poly(sodium 4–styrenesulfonate) was the most effective against bacterial adhesion, having reduced it by 60 %, followed by poly(4-vinyl-N-isobutylpyridinium bromide)/poly(sodium 4– styrenesulfonate) (47 %), and poly(allylamine hydrochloride)/poly(sodium 4–styrenesulfonate) (38 %). Polyelectrolyte multilayers with quaternary amine groups have a significant anti-adhesion potential and could find their place in coatings for food, pharmaceutical, and medical industry.

Integration of two or more biomolecules with synergetic and complementary effects on a material surface can help to obtain multi-functions for various biomedical applications. However, the amounts of biomolecules integrated and their physiological functions are compromised due to the limited surface anchoring sites. Herein, we propose a novel concept of film engineering strategy “from surface to bulk synergetic modification”. This new concept is realized by employing the surface amine groups of plasma polymerized allylamine (PPAm) film for grafting a molecule e.g., thrombin inhibitor, bivalirudin (BVLD), meanwhile its bulk amine groups is used as a universal depot for storing and releasing therapeutic nitric oxide (NO) gas as supplement to the functions of BVLD. It is demonstrated that such a “from surface to bulk synergetic modification” film engineering can impart the modified-substrates with anti-platelet and anti-coagulant dual functions, giving rise to a highly endothelium-mimetic thromboresistant property. We believe that our research provides a very promising strategy to deliver multifunctional surface versatilely that require NO release in combination with other properties, which will find broad biomedical applications in blood-contacting devices, and et al. Moreover, it also provides a brand-new film engineering strategy for tailoring surface multi-functionalities of a wide range of materials., Graphical abstract Image 1, Highlights • A concept of “from surface to bulk synergetic modification” is proposed for tailoring surface multi-functionalities. • The surface amine groups of plasma polymerized allylamine (PPAm) film were used for grafting bivalirudin. • The bulk amine groups of PPAm film is utilized as the universal depots for storing and releasing nitric oxide.

Herein, we report redox responsive, colon cancer targeting poly(allylamine) (PA)/eudragit S-100 (EU) nanoparticles (PAEU NPs) (≈59 nm). These disulfide crosslinked PAEU NPs are developed via air oxidation of thiolated PA and thiolated EU, eliminating the need of any external crosslinking agent for dual drug delivery. PAEU NPs can effectively encapsulate both hydrophilic doxorubicin (DOX) and hydrophobic curcumin (Cur) drug with ≈85 % and ≈97 % encapsulation efficiency respectively. Here, the combination of drugs having different anticancer mechanism offers the possibility of developing nanosystem with enhanced anticancer efficacy. The developed PAEU NPs show good colloidal stability and low drug release under physiological conditions, while high DOX (≈98 %) and Cur (≈93 %) release is observed in reducing environment (10 mM GSH). Further, DOX and Cur loaded PAEU NPs exhibit higher cancer cell killing efficiency as compared to individual free drugs. In vivo biodistribution studies with Balb/C mice display the retention of PAEU NPs in the colon region up to 24 h presenting the developed approach as an efficient way for colorectal cancer therapy.

Bacterial adhesion can be controlled by different material surface properties, such as surface charge, on which we concentrate in our study. We use a silica surface on which poly(allylamine hydrochloride)/sodium poly(4-styrenesulfonate) (PAH/PSS) polyelectrolyte multilayers were formed. The corresponding surface roughness and hydrophobicity were determined by atomic force microscopy and tensiometry. The surface charge was examined by the zeta potential measurements of silica particles covered with polyelectrolyte multilayers, whereby ionic strength and polyelectrolyte concentrations significantly influenced the build-up process. For adhesion experiments, we used the bacterium Pseudomonas aeruginosa. The extent of adhered bacteria on the surface was determined by scanning electron microscopy. The results showed that the extent of adhered bacteria mostly depends on the type of terminating polyelectrolyte layer, since relatively low differences in surface roughness and hydrophobicity were obtained. In the case of polyelectrolyte multilayers terminating with a positively charged layer, bacterial adhesion was more pronounced than in the case when the polyelectrolyte layer was negatively charged.

Although electrostatic modification of bacterial surfaces using polyelectrolytes (PEs) is a convenient and versatile tool for biotechnological processes, the ambiguities in toxicity of PEs between various bacteria and the insufficient understanding of the mechanism of action of cationic PEs and their nano-thick shells formed around the bacteria create a bottleneck of the approach. Here, we show how the viability of two bacterial strains, Escherichia coli and Pseudomonas stutzeri, both from the Gram-negative group differs, when the cells are exposed to cationic PEs under different conditions. Although the cell wall architecture of the strains should be structurally similar, we found that the viability of E. coli was not affected by the electrostatic deposition of polyethyleneimine (PEI) or poly(allylamine) hydrochloride (PAH), whereas for P. stutzeri the deposition resulted in high death rates. The cells of E. coli proved to be suitable templates for Layer-by-Layer (LbL) modification, while in P. stutzeri a modified protocol with mild conditions had to be used to ensure the viability of the cells. Super resolution stimulated emission depletion (STED) microscopy allowed us to clearly visualize that after PE deposition onto the surface of the cells, the PEs could penetrate inside the cells of P. stutzeri, while forming a capsule around E. coli as expected. Therefore, this knowledge will help us select the most appropriate combinations of strains and PEs, for biotechnological processes or biomedical application, preventing unwanted toxicity.

Herein, we report on a new type of ethanol biosensor based on a screen-printed electrode modified with poly(allylamine hydrochloride). The alcohol dehydrogenase was immobilized on the surface of the sensor using the sol–gel matrix. Working parameters such as applied potential, pH, NAD+ concentration, storage conditions were optimized. A response range between 0.05 and 2 mM was found with a sensitivity of 13.45 ± 0.67 µA/mM·cm2 and a detection limit of 20 µM. The developed biosensor was used to detect ethanol in commercial beverages with good accuracy.