A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic–organic composite membrane

• Jonathan Stott and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2020, 11, 938–951, doi:10.3762/bjnano.11.78

• Fores et al. The authors realized peptide hydrogels in a porous melamine foam for use in continuous flow chemistry [30]. Other polyelectrolytes such as poly(acrylic acid) were prepared using an ozone-induced grafting process for cellulose fibers [31]. Hydrophobic foams of poly(γ-benzyl-ʟ-glutamate-co-ʟ

• chose phenylalanine as an aromatic and hydrophobic amino acid to achieve a good interaction with slightly water-soluble compounds (e.g. chloroanilic acid) in aqueous solutions. Due the lack of amino groups in the side chain of phenylalanine, no further protection groups are needed for NCA-synthesis and

• therefore phenylalanine serves as an ideal and straightforward test bed. To the best of our knowledge, in situ formation and grafting of hydrophobic organo-gels within an inorganic porous environment has not been studied so far. As an inorganic substrate, sintered porous alumina membranes were

Preparation, characterization and photocatalytic performance of heterostructured CuO–ZnO-loaded composite nanofiber membranes

• Wei Fang,
• Liang Yu and
• Lan Xu

Beilstein J. Nanotechnol. 2020, 11, 631–650, doi:10.3762/bjnano.11.50

• PVDF/PAN weight ratios are displayed in Figure 4. All CNFMs are hydrophobic, and the hydrophobicity of the CNFMs decreases slightly with decreasing weight ratio. The reason might be that the hydrophobicity of pure PVDF nanofiber membranes (NFMs) is higher than that of pure PAN NFMs. Also, nanofiber

Silver-decorated gel-shell nanobeads: physicochemical characterization and evaluation of antibacterial properties

• Marta Bartel,
• Katarzyna Markowska,
• Marcin Strawski,
• Krystyna Wolska and
• Maciej Mazur

Beilstein J. Nanotechnol. 2020, 11, 620–630, doi:10.3762/bjnano.11.49

• reduction of AgNO3 with sodium borohydride). Since polystyrene is hydrophobic, the adsorption of hydrophilic Ag species in aqueous medium results in a decrease of the Gibbs surface free energy. The advantage of this method is its simplicity. However, even though it was demonstrated that the resulting

• structures are stable in aqueous solution, this may not be the case after addition of surfactants or the exchange of the solvent for a more hydrophobic one. Zhao et al. [23] proposed to incorporate silver nanoparticles into polystyrene/polystyrene sulfonate particles through accumulation of a silver complex

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• ) 8.1 times that of commercial, activated carbon for AR1. The remarkable adsorption of AR1 and JGB over KOH-900 could be explained by the combined mechanisms of hydrophobic, π–π, electrostatic and van der Waals interactions. Keywords: acid red 1; adsorption; bulky dye molecules; Janus green B

• other adsorbent, KOH-900 showed the highest performance in AR1 adsorption, as shown in Figure 3. Therefore, hydrophobic interaction can be suggested as a plausible mechanism for AR1 and JGB adsorption. This mechanism, which has been suggested earlier in adsorption of malachite green [52], aromatics [64

• the bulky dye molecules. In summary, the remarkable adsorption of AR1 and JGB over KOH-900 can be explained by the combined mechanisms of hydrophobic, π–π, electrostatic and van der Waals interactions. Competitiveness of KOH-900 in adsorption of dyes Based on the remarkable performance of KOH-900 in

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• interact with the proteins [22]. The affinity of a protein for a certain surface and the mode of interaction rise from the interplay of electrostatic interactions, hydrogen bondings, and hydrophobic forces [32]. Both nanomaterials are negatively charged at physiological pH. However, SNPs exhibit a less

• groups/nm2 [31][32]. Both surfaces exhibit surface sites able to form hydrogen bonds or hydrophobic interaction with proteins. However, such tendency may be different since hydrogen bond formation obeys geometrical constraints due to the directional character of this bond. On the other hand, both silica

• and carbon surfaces exhibit hydrophobic patches, i.e., siloxane bridges and carbon–carbon bonds, respectively. These moieties have a different nature, exhibiting a higher dipolar character. Previous studies reported fibrinogen-induced aggregation for silica nanoparticles [23][40]. However, in these

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• various forces, mostly electrostatic interactions, hydrogen bonding, covalent bonding, host–guest interactions and other interactions (e.g., hydrophobic and biospecific recognition) as shown in Figure 3. Electrostatic interactions The LbL assemblies were originally applied to both charged planar

• calixarene units covalently bound in various ways. Although there are many reports on calixerene [59], cyclodextrins offer a wide scope for such interactions in biological applications. They could act as a host for many biomolecules or drugs via hydrogen bonding, hydrophobic interaction or van der Waals

• thickening at elevated temperatures was responsible for trapping the macromolecules inside the capsules. The hydrophobic molecules could be loaded into multilayer capsules by changing the state of the capsules from open to closed via a polarity change [73]. Alternatively, water soluble, positively charged

Preparation and in vivo evaluation of glyco-gold nanoparticles carrying synthetic mycobacterial hexaarabinofuranoside

• Gennady L. Burygin,
• Polina I. Abronina,
• Nikita M. Podvalnyy,
• Sergey A. Staroverov,
• Leonid O. Kononov and
• Lev A. Dykman

Beilstein J. Nanotechnol. 2020, 11, 480–493, doi:10.3762/bjnano.11.39

• -induced coagulation (due to electrostatic and hydrophobic interactions and structural-mechanical stability factors) [57][97][98]. The minimal stabilizing concentrations for both glycosides 1 and 2 were found to be 100 μg·mL−1. This concentration was used to conjugate antigens 1 and 2 with GNPs, which gave

• may be related to the formation of reaction solutions with modified structures featuring different supramolecular assemblies of the reagents (supramers [104]) in solution. In a similar fashion, solutions of Ara6C2NH2-GNPs 3 with the shorter and more hydrophobic С2 spacer aglycon might form tighter

Brome mosaic virus-like particles as siRNA nanocarriers for biomedical purposes

• Alfredo Nuñez-Rivera,
• Pierrick G. J. Fournier,
• Danna L. Arellano,
• Ana G. Rodriguez-Hernandez,
• Rafael Vazquez-Duhalt and
• Ruben D. Cadena-Nava

Beilstein J. Nanotechnol. 2020, 11, 372–382, doi:10.3762/bjnano.11.28

• internalization of VLPs In order to test the cell internalization of VLPs, BMV and CCMV VLPs were loaded with NanoOrange, a hydrophobic fluorescent dye. Both BMV and CCMV viruses have hydrophobic residues in their capsid protein in which hydrophobic molecules, such as NanoOrange, are bound. Due to the high

• internalization To visualize the cell internalization, viruses were loaded with NanoOrange. These are hydrophobic molecules that bind to the hydrophobic domains of the capsid proteins of BMV and CCMV. NanoOrange (NanoOrange™ Protein Quantitation Kit; ThermoFisher Scientific) were incubated with 1 µg of BMV or

Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine

• Valentina Francia,
• Daphne Montizaan and
• Anna Salvati

Beilstein J. Nanotechnol. 2020, 11, 338–353, doi:10.3762/bjnano.11.25

• side effects [6]. Additionally, nanomedicines can encapsulate different types of hydrophilic and hydrophobic drugs, and they can be designed to control their release profile [7]. Several other characteristics of nanomaterials such as size, material, shape, surface charge, hydrophobicity, roughness, and

• specific carriers) [72][73], membrane bending, which occurs through different mechanisms, including the insertion of hydrophobic protein motifs in the membrane, local recruitment of membrane-bending domains, or scaffolding by proteins (the classic example being clathrin) [72][73][77][78], and scission of

Rational design of block copolymer self-assemblies in photodynamic therapy

• Maxime Demazeau,
• Laure Gibot,
• Anne-Françoise Mingotaud,
• Patricia Vicendo,
• Clément Roux and
• Barbara Lonetti

Beilstein J. Nanotechnol. 2020, 11, 180–212, doi:10.3762/bjnano.11.15

• that could be either hydrophobic or a polyelectrolyte enabled the creation of numerous systems [8]. Depending on their structure, copolymers may also form self-assemblies. This is typically the case for amphiphilic block copolymers, which can form in aqueous solution polymer nanoobjects such as

• micelles or vesicles. The driving forces of this assembly are a loss of entropy during the self-assembly and different interactions acting on the monomer units of the polymer. Whereas polymer/polymer interactions are favored for the hydrophobic block, interactions between the hydrophobic block and water

• are strongly disfavored, leading to the isolation of the hydrophobic block into core or membranes [9]. In the last twenty years, thousands of papers have been published on this topic and the reader is referred to recent reviews [10][11][12][13][14]. Basically, the desired properties of an ideal

Molecular architectonics of DNA for functional nanoarchitectures

• Debasis Ghosh,
• Lakshmi P. Datta and
• Thimmaiah Govindaraju

Beilstein J. Nanotechnol. 2020, 11, 124–140, doi:10.3762/bjnano.11.11

• acid (PNA) dimers (clamps) via WC and Hoogsteen base pairing interactions (Figure 6) [75]. The hydrogen bonding interactions, along with hydrophobic interactions, imparted by the nucleobases and the NDI core, facilitated the formation of versatile nano- and microarchitectures. The morphological

• hydrophobic effects and characteristic optical responses to monitor the insertion mechanism. Notably, the position of conjugation and the number of porphyrin units were crucial parameters that significantly affected the insertion process. Asanuma and co-workers incorporated six methyl red chromophores into a

• of DNA, and this concept has been exploited by Trau and co-workers to analyze the different interaction patterns of methylated and nonmethylated DNA with gold nanoparticles [22]. The consistent and high methylation level of genomes makes the DNA more hydrophobic, while the distinct methylation in

Internalization mechanisms of cell-penetrating peptides

• Ivana Ruseska and
• Andreas Zimmer

Beilstein J. Nanotechnol. 2020, 11, 101–123, doi:10.3762/bjnano.11.10

• [20]. The second class within this classification scheme is formed by CPPs which noncovalently complex their cargo. They occur mostly as amphipathic peptides, consisting of a hydrophilic and a hydrophobic domain. Pep-1 and MPG are amphipathic peptides which are reported to form stable, noncovalent

• complexes with cargo molecules through electrostatic interaction. Pep-1 has successfully been used to deliver small peptides and proteins into cells, while MPG has shown to efficiently deliver small interfering RNA (siRNA) into cultured cell lines [3][10]. The interplay between hydrophilic and hydrophobic

• sequentially hydrophilic and hydrophobic amino acids in their primary structure [5][21]. This group includes MPG, penetratin, CADY, pVec, and other peptides. Secondary amphipathic peptides commonly have less than 20 amino acids in their sequence and are able to take their α-helix or β-sheet conformation after

Recent progress in perovskite solar cells: the perovskite layer

• Xianfeng Dai,
• Ke Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2020, 11, 51–60, doi:10.3762/bjnano.11.5

• improves the adhesion of the perovskite ink to hydrophobic substrates, effectively inhibiting the solution flow dynamics in the drying perovskite ink layer leading to compact and uniform perovskite films. The very small amount of surfactant additive has no adverse effect on the optoelectronic properties of

• new 2D/3D perovskite materials by incorporating hydrophobic alkylammonium salts with halogen functional groups (2-chloroethylammonium chloride and 2-bromoethylammonium bromide) into formamidinium-based 3D perovskites. By adjusting the relative amount of the ammonium salts the mixing ratio of the 2D

• and 3D perovskite phases could be controlled. The hydrophobic alkylammonium cations remarkably enhanced the humidity resistance of the 2D/3D mixtures. In addition, the halogen functional groups in the alkylammonium salts could cause changes of the electron cloud distribution and also enhance the

An investigation on the drag reduction performance of bioinspired pipeline surfaces with transverse microgrooves

• Weili Liu,
• Hongjian Ni,
• Peng Wang and
• Yi Zhou

Beilstein J. Nanotechnol. 2020, 11, 24–40, doi:10.3762/bjnano.11.3

• the drag [12]. It is well known that organisms found in nature provide substantial inspiration for solving engineering problems. Bionic research has found that some natural organisms form a specific surface structure with antidrag [13], antiwear [14][15], and hydrophobic [16][17] performance through

Fully amino acid-based hydrogel as potential scaffold for cell culturing and drug delivery

• Dávid Juriga,
• Evelin Sipos,
• Orsolya Hegedűs,
• Gábor Varga,
• Miklós Zrínyi,
• Krisztina S. Nagy and
• Angéla Jedlovszky-Hajdú

Beilstein J. Nanotechnol. 2019, 10, 2579–2593, doi:10.3762/bjnano.10.249

• with different swelling properties (and also different stiffness). The PSI-based gels show a low swelling degree at pH 8 due to the hydrophobic character of the PSI backbone (Figure 2a). Since PSI is insoluble in water, the Huggins interaction parameter increases in an aqueous medium, hence, the gels

Small protein sequences can induce cellular uptake of complex nanohybrids

• Jan-Philip Merkl,
• Malak Safi,
• Christian Schmidtke,
• Fadi Aldeek,
• Johannes Ostermann,
• Tatiana Domitrovic,
• Sebastian Gärtner,
• John E. Johnson,
• Horst Weller and
• Hedi Mattoussi

Beilstein J. Nanotechnol. 2019, 10, 2477–2482, doi:10.3762/bjnano.10.238

• (not to scale). The central QD (red, yellow, blue = core/shell/shell) is embedded in a crosslinked polymer micelle, consisting of a hydrophobic block (red) and an amphiphilic block (PEO). Interaction of the QDs with AuNPs (purple) is driven by the amine functional group. Gold nanoparticles are His

pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

• Saban Kalay,
• Yurij Stetsyshyn,
• Volodymyr Donchak,
• Khrystyna Harhay,
• Ostap Lishchynskyi,
• Halyna Ohar,
• Yuriy Panchenko,
• Stanislav Voronov and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2019, 10, 2428–2439, doi:10.3762/bjnano.10.233

• polymer brushes via polymerization initiated from their surface [12][28]. In particular, BNNTs were covalently modified with hydrophobic polystyrene or poly(glycidyl methacrylate) polymer brushes [28]. The modified nanotubes demonstrated high dispersibility in a large number of organic solvents. In our

• aggregation of poly(acrylic acid) due to hydrophobic interactions was shown [54]. At neutral or basic pH, the hydrodynamic diameter of the poly(acrylic acid) macromolecules was significantly decreased, indicating the disruption of intermolecular aggregates [54]. Cellular imaging using P(AA-co-FA

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• quantum yields are typically prepared in organic solvents at high temperatures using hydrophobic capping agents such as oleic acid [16][17]. Life sciences applications of these NPs require to render them water-dispersible using either ligand exchange or encapsulation procedures [2][13][18][19]. This can

• be similarly necessary for applications in plasmonics or chemical sensing [20][21]. One of the most versatile ways to protect the surface of NP, making hydrophobic particle surfaces hydrophilic and simultaneously providing functional groups for subsequent covalent attachment of, e.g., biomolecules

• monodisperse particles with just one UCNP core in the center coated by a thick silica shell are obtained. This method should also be suitable for other NPs with hydrophobic surfaces dispersed in an apolar solvent independent of their chemical composition. Results and Discussion The core particles used in this

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• of operation/storage. The weak interaction of the toluene molecule with the surface of both functionalised and non-functionalised sensors can be explained by the hydrophobic–hydrophobic interaction between the functional groups of the monolayer (CH3 groups) and the CH3 group of the toluene molecule

• -mercaptohexadecanoic acid (MHDA) showed no response to aromatic vapours [22]. As presented in Table 1, the vapours tested are nonpolar in nature and therefore have a high affinity with the hydrophobic CH3 group of the HDT. On the contrary, MHDA molecules are carboxylic acid terminated thiols, which are hydrophilic

• the sensor response was studied in a previous work [32]. The response to vapours remains basically unchanged for sensors employing hydrophobic thiols due to their hydrophobicity [31]. Such long-chain alkanethiol functionalised and decorated MWCNTs showed a high contact angle with water, which remains

Design of a nanostructured mucoadhesive system containing curcumin for buccal application: from physicochemical to biological aspects

• Sabrina Barbosa de Souza Ferreira,
• Gustavo Braga,
• Évelin Lemos Oliveira,
• Jéssica Bassi da Silva,
• Hélen Cássia Rosseto,
• Lidiane Vizioli de Castro Hoshino,
• Mauro Luciano Baesso,
• Wilker Caetano,
• Craig Murdoch,
• Helen Elizabeth Colley and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2019, 10, 2304–2328, doi:10.3762/bjnano.10.222

• elucidated by incorporation kinetics and location studies. They revealed that the drug was quickly incorporated and located in the hydrophobic portion of nanometer-sized polymeric micelles. Moreover, the systems displayed plastic behavior with rheopexy characteristics at 37 °C, viscoelastic properties and a

• increase of temperature can promote the self-assembly from unimers to micelles, with large endothermic heat. In this sense, PPO-groups dehydrate in a hydrophobic core with a surrounding hydrated shell. Higher concentrations of P407 are used (15% to 20%, w/w) as colloidal gelling systems in a cubic

• hexagonal core with ordered structure, which enable the solubilization of hydrophilic and hydrophobic drugs [4][5][6][7][8][9]. Moreover, C974P is an acrylic-acid derivative, highly cross-linked, hydrophilic, and displays mucoadhesive properties [1]. In this sense, an increase in temperature promotes the

Mannosylated brush copolymers based on poly(ethylene glycol) and poly(ε-caprolactone) as multivalent lectin-binding nanomaterials

• Stefania Ordanini,
• Wanda Celentano,
• Anna Bernardi and
• Francesco Cellesi

Beilstein J. Nanotechnol. 2019, 10, 2192–2206, doi:10.3762/bjnano.10.212

• aggregates (e.g., micelles and vesicles) above their critical aggregation concentration (CAC). The resulting self-assembled nanoparticles can act as drug carriers and delivery systems, being able to accommodate a hydrophobic drug within their hydrophobic core [22], or chemically bind bioactive agents [23][24

• tendency may be due to the presence of the mannose residues that, being connected to the hydrophobic PCL chains, could affect the self-assembly of the macromolecules and generate some aggregates. Remarkably, four-arm species had a slightly lower Dh than the corresponding linear species. Turbidity assay The

Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions

• Da Shi,
• Justine Wallyn,
• Dinh-Vu Nguyen,
• Francis Perton,
• Delphine Felder-Flesch,
• Sylvie Bégin-Colin,
• Mounir Maaloum and
• Marie Pierre Krafft

Beilstein J. Nanotechnol. 2019, 10, 2103–2115, doi:10.3762/bjnano.10.205

• fluorinated chains are reinforced by very effective hydrophobic repulsion caused by the proximity of the water phase. Figure 5 depicts the inverse of the characteristic adsorption time (1/τ) as a function of the Fe concentration of the dendronized IONPs. The 1/τ values increase with increasing Fe

Ion mobility and material transport on KBr in air as a function of the relative humidity

• Dominik J. Kirpal,
• Korbinian Pürckhauer,
• Alfred J. Weymouth and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2019, 10, 2084–2093, doi:10.3762/bjnano.10.203

• small and sharp splinter of a smashed sapphire bulk crystal was used as a tip. Sapphire is a very hard material, it is hydrophobic with a contact angle to water above 80°[20], and it is chemically inert [21]. The high hardness allows us to create large artificial defects in our sample (as described

Porous silver-coated pNIPAM-co-AAc hydrogel nanocapsules

• William W. Bryan,
• Riddhiman Medhi,
• Maria D. Marquez,
• Supparesk Rittikulsittichai,
• Michael Tran and
• T. Randall Lee

Beilstein J. Nanotechnol. 2019, 10, 1973–1982, doi:10.3762/bjnano.10.194

• by the lower critical solution temperature (LCST); that is, the temperature at which the hydrogel polymers become hydrophilic and soluble in aqueous solutions, or conversely, hydrophobic and insoluble in aqueous solutions [57][58][59]. Interestingly, through chemical modification, the LCST can be

• to the collapse of the hydrogel polymer due to increased hydrophobic interactions in the polymer hydrogel network [58]. Ionizable groups such as AAc and AAm are grafted into the polymer backbone to increase electrostatic interactions. The introduction of AAc, which has ionizable COOH groups, induces

High-tolerance crystalline hydrogels formed from self-assembling cyclic dipeptide

• Yongcai You,
• Ruirui Xing,
• Qianli Zou,
• Feng Shi and
• Xuehai Yan

Beilstein J. Nanotechnol. 2019, 10, 1894–1901, doi:10.3762/bjnano.10.184

• , which provide a substantial tendency for self-assembly and the formation of gels. In addition, other weak forces, such as π–π stacking, hydrophobic effect, electrostatic interactions, and van der Waals forces, are also serviceable in driving molecular self-assembly of CDPs toward the formation of gels

• ) (Figure 2A). Thioflavin T (ThT) and nile red (NR), two specific dyes for hydrophobic domains and beta-sheet secondary structures, respectively, were used to obtain insights into the detailed interior structure of the hydrogel [49]. CLSM results confirmed that the C-WY hydrogel contains both hydrophobic

• crystal pattern. (A) CLSM images of the C-WY hydrogel in light field. NR was used to indicate the formation of hydrophobic domains (red color, B) and ThT was used to indicate the beta-sheet secondary structures (blue color, C). (D) XRD pattern of the hydrogel. (E) POM images in cross-polarized light mode