Bioselectivity of silk protein-based materials and their bio-inspired applications

• Hendrik Bargel,
• Vanessa T. Trossmann,
• Christoph Sommer and
• Thomas Scheibel

Beilstein J. Nanotechnol. 2022, 13, 902–921, doi:10.3762/bjnano.13.81

• not allow good and sufficient cell attachment necessary for tissue engineering applications. However, several independent studies showed that the materials made of the positively charged eADF4(κ16) variant enabled partial cell adhesion due to the positive surface charge derived from lysine residues in

• the primary amino acid sequence [150][162][163]. Since cells expose many negatively charged molecules on their cellular surface, charge modification is often used to guide cellular interaction [164][165][166]. In the example of the recombinant 4RepCT spider silk, several charged amino acid residues in

Gelatin nanoparticles with tunable mechanical properties: effect of crosslinking time and loading

• Agnes-Valencia Weiss,
• Daniel Schorr,
• Julia K. Metz,
• Metin Yildirim,
• Saeed Ahmad Khan and
• Marc Schneider

Beilstein J. Nanotechnol. 2022, 13, 778–787, doi:10.3762/bjnano.13.68

• optimal treatment. Therefore, the characteristics of nanoparticles regarding mechanical properties, size, surface charge, surface composition, and degradation and drug release mechanisms must be considered during formulation development [1]. Except for the mechanical properties, the research activities do

• macromolecules, such as proteins [12] and peptides [13], or in the field of gene delivery [14]. The surface charge of gelatin nanoparticles at physiological pH can be easily influenced by the choice of gelatin type [15]. Crosslinking of gelatin nanoparticles is still inevitable to obtain particles that are

• polydispersity index (PdI) from 0.075 to 0.115, indicating a narrow size distribution. Crosslinking for 15 min did not result in stable particles with uniform colloidal properties. The surface charge of gelatin nanoparticles is clearly pH-dependent. At a pH value of 7.5 ± 0.1, the zeta potential values ranged

Stimuli-responsive polypeptide nanogels for trypsin inhibition

• Petr Šálek,
• Jana Dvořáková,
• Sviatoslav Hladysh,
• Diana Oleshchuk,
• Ewa Pavlova,
• Jan Kučka and
• Vladimír Proks

Beilstein J. Nanotechnol. 2022, 13, 538–548, doi:10.3762/bjnano.13.45

• varied from 0.233 to 0.258 at 25 °C and from 0.233 to 0.289 at 37 °C within the tested pH range from 4 to 7.4. Therefore, we assumed that the dependence of DH of Nα-Lys-NG nanogel on the pH could be significantly distorted. The surface charge analysis showed that Nα-Lys-NG nanogel was more anionic in

The effect of metal surface nanomorphology on the output performance of a TENG

• Yiru Wang,
• Xin Zhao,
• Yang Liu and
• Wenjun Zhou

Beilstein J. Nanotechnol. 2022, 13, 298–312, doi:10.3762/bjnano.13.25

• charge density [35][36][37], (2) reduction of the impact of the external environment on TENGs [38][39], (3) enhancement of the surface charge density, including active charge pumping and intercalation of a charge trap layer [40][41], and (4) increase of the number of TENG units [42][43]. In order to

• improve the surface charge density in the contact electrification process, it is necessary to expand the effective contact surface area by surface engineering of micro-/nanoscale structures [44][45][46]. There are various processes for the surface engineering of polymers with micro-/nanoscale structures

• sizes on the energy harvesting efficiency of the TENG were studied. The enhancement effect of different surface charge density distributions on the output performance of the nanostructured metal TENGs is explained. Experimental Materials and characterization In this study, 1 M sulfuric acid, copper

Relationship between corrosion and nanoscale friction on a metallic glass

• Haoran Ma and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2022, 13, 236–244, doi:10.3762/bjnano.13.18

• anodic polarization results in a net positive surface charge [36][37], caused by the accumulation of the dissolved metal cations on the inner layer and strengthens the adhesion of the negatively charged silicon AFM tip [38][39]. Figure 5d depicts schematically this charge buildup at the surface of the

• reveals a stable surface charge with different periods of immersion time. We conclude that there is an equilibrium between the production of metal cations by dissolution and diffusion of the ions into the solution, which entails the constant surface charge. In other words, during immersion in phosphate

• buffer, the ion transfer is limited by the dissolution rate. Anodic polarization in phosphate buffer with its stronger metal ion dissolution leads to an accumulation of cations on the surface and, thus, to a higher surface charge. In NaCl solution, adhesion increases with immersion time, indicating an

Engineered titania nanomaterials in advanced clinical applications

• Padmavati Sahare,
• Paulina Govea Alvarez,
• Juan Manual Sanchez Yanez,
• Gabriel Luna-Bárcenas,
• Samik Chakraborty,
• Sujay Paul and
• Miriam Estevez

Beilstein J. Nanotechnol. 2022, 13, 201–218, doi:10.3762/bjnano.13.15

• found that nps smaller than 100 nm produce more ROS due to their higher surface area [29]. Properties of nps such as surface charge density and zeta potential are influential in determining their reactivity, agglomeration properties, interaction with cells, stability in complex media, and adsorption of

• prevention of agglomeration [102]. Titania nanostructures are capable of loading molecules of various sizes, charges, and solubilities. The immobilization of drugs and their release profile is affected by the size and surface charge distribution of the drug molecule. It has been stated that for the long-term

Theranostic potential of self-luminescent branched polyethyleneimine-coated superparamagnetic iron oxide nanoparticles

• Rouhollah Khodadust,
• Ozlem Unal and
• Havva Yagci Acar

Beilstein J. Nanotechnol. 2022, 13, 82–95, doi:10.3762/bjnano.13.6

• and a positive surface charge. The former is very important for the pharmacokinetics of nanoparticles and needed for long blood circulation time, especially when a molecular targeting is aimed [36][37][38]. The latter is essential for the highly popular gene therapy, especially in the treatment of

Biocompatibility and cytotoxicity in vitro of surface-functionalized drug-loaded spinel ferrite nanoparticles

• Sadaf Mushtaq,
• Khuram Shahzad,
• Tariq Saeed,
• Anwar Ul-Hamid,
• Bilal Haider Abbasi,
• Nafees Ahmad,
• Waqas Khalid,
• Muhammad Atif,
• Zulqurnain Ali and
• Rashda Abbasi

Beilstein J. Nanotechnol. 2021, 12, 1339–1364, doi:10.3762/bjnano.12.99

• electrophoresis. All samples moved towards the positive potential due to the negatively charged PMA coating (Figure 2d). The colloidal stability (i.e., hydrodynamic size, surface charge, and polydispersity index, PDI) of NPs was assessed using dynamic light scattering (DLS). All NPs (PMA-coated, and drug-attached

• ) dispersed in deionized water, sodium borate buffer (SBB) pH 9.0, phosphate buffer saline (PBS) pH 7.4, and DMEM were used for zeta potential measurements. The purpose of using buffers (i.e., SBB, PBS) was to get indirect surface charge information. Deionized water was used to check the influence of

• drug molecules and NPs were acid labile in nature, resulting in the detachment of the drug from NPs under acidic conditions (pH. 5.5) [32]. The drug release became slower and sustained after that. Acidic conditions change the surface charge density which causes deionization of amide bonds, resulting in

Identifying diverse metal oxide nanomaterials with lethal effects on embryonic zebrafish using machine learning

• Richard Liam Marchese Robinson,
• Haralambos Sarimveis,
• Philip Doganis,
• Xiaodong Jia,
• Marianna Kotzabasaki,
• Christiana Gousiadou,
• Stacey Lynn Harper and
• Terry Wilkins

Beilstein J. Nanotechnol. 2021, 12, 1297–1325, doi:10.3762/bjnano.12.97

• representing different qualitative characteristic values for core shape, surface charge and purity [31], or the presence/absence of surface functional groups as important. Also, for example, elevated significance could be assigned to variables such as the Pauling metal atom electronegativity and the average

• variability in biological effects [28][29][31]. It is possible that our results regarding the limited significance of surface characteristics may be skewed by the manner in which surface chemical composition was represented using descriptors and the incomplete availability of surface charge information. (See

• for modelling of the 120 hpf excess lethality data could reflect biological significance arising from the nature of any surface coatings, rather than the presence or absence of any organic coating having general significance. Second, qualitative surface charge information, including “unknown” status

A review on slip boundary conditions at the nanoscale: recent development and applications

• Ruifei Wang,
• Jin Chai,
• Bobo Luo,
• Xiong Liu,
• Jianting Zhang,
• Min Wu,
• Mingdan Wei and
• Zhuanyue Ma

Beilstein J. Nanotechnol. 2021, 12, 1237–1251, doi:10.3762/bjnano.12.91

• this conclusion was drawn based on an ideal Lennard–Jones fluid. Its applicability on other Newtonian fluids with properties such as polarity and even on non-Newtonian fluids should be further validated. 2.2 Surface charge effects Investigating electrokinetics phenomena, including electro-osmosis

• applied electric field. Due to the surface charge on the solid surface, an electrical double layer (EDL), which is comprised of oppositely charged ions, naturally forms within the liquid in the vicinity of the solid surface. As shown in Figure 5, the EDL consists of an immobile Stern layer and a mobile

• experience a slippage [80]. In addition, the hydrodynamic slippage at the solid–liquid interface can in turn largely enhance the electro-osmotic velocity, which increases the urgency for a deep research on the liquid slippage phenomena in electrokinetics. Owing to the direct influence of surface charge

Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• material upon interaction with target gas analytes arise due to changes in, for instance, energy bands, surface charge, and work function caused by temperature, grain size, crystal plane energies, and doping [87][90][91]. Thus, there is no single sensing mechanism that explains all SMO gas sensors. The

pH-driven enhancement of anti-tubercular drug loading on iron oxide nanoparticles for drug delivery in macrophages

• Karishma Berta Cotta,
• Sarika Mehra and
• Rajdip Bandyopadhyaya

Beilstein J. Nanotechnol. 2021, 12, 1127–1139, doi:10.3762/bjnano.12.84

•  1). The NOR@IONPs also carry a surface charge and neutral pH. Thus indicating that these particles indeed have an improved stability, possibly due to the coating of drug. NOR@IONPpH5 also appear to have a higher drug loading. It was noted that both NOR@IONPpH5 and NOR@IONPpH10 had 2–3 nm larger

• identical treatment conditions (Figure 6a). The increased uptake could be due to active engulfment of nanoparticles by macrophages, due to their larger size (20–120 nm size range) and surface charge (+29 mV or −16.5 mV) [46], which results in simultaneous internalization of larger amounts of drug. Figure 6b

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• charged hydrophilic thiols (sodium 2-mercaptoethyl sulfonate, mercaptopropionic acid, 2-mercaptoethanol, 2-(dimethylamino)ethanethiol hydrochloride, and thiocholine) to vary the surface charge of the SERS substrate. We used two oppositely charged porphyrins, cationic copper(II) tetrakis(4-N-methylpyridyl

• the surface charge of the substrate, which tends to be negative. Using the data obtained and our model SERS system, we analyzed the modification of the Ag surface by different reagents (lithium chloride, polyethylenimine, polyhexamethylene guanidine, and multicharged metal ions). Finally, all those

• suggest that some negatively charged centers are still present at the NP surfaces after thiocholine modification, such as, for example, adsorbed chloride thiocholine counter ions, which contribute to the resulting surface charge. The experimental data obtained support previous reports about the great

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

• Sepand Tehrani Fateh,
• Lida Moradi,
• Elmira Kohan,
• Michael R. Hamblin and
• Amin Shiralizadeh Dezfuli

Beilstein J. Nanotechnol. 2021, 12, 808–862, doi:10.3762/bjnano.12.64

Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• conductive materials into a micro/nanorobot and then adjusting the surface charge of the robot or the electrochemical reaction on the interface through electric fields can also yield actuation. Zhang et al. [29] proposed an interdigital microelectrode system. When an AC electric field is applied, metal

Fate and transformation of silver nanoparticles in different biological conditions

• Barbara Pem,
• Marija Ćurlin,
• Darija Domazet Jurašin,
• Valerije Vrček,
• Rinea Barbir,
• Vedran Micek,
• Raluca M. Fratila,
• Jesus M. de la Fuente and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2021, 12, 665–679, doi:10.3762/bjnano.12.53

• medical products may be related to human exposure and safety as AgNPs may undergo complex transformations in biological media [6]. It is well known that AgNP physicochemical characteristics, such as size, shape, surface charge, surface functionalization, or core composition determine their interactions

• such conditions, the repulsive electrostatic forces between particles with the same surface charge are weakened, leading to aggregation upon collision [10]. The AgNPs with bulky coatings are less sensitive to this, since their stabilisation is steric and not electrostatic [14]. The dissolution of AgNPs

• AgNPs in artificial biological media In order to gain more coherent insight into the transformation of different AgNPs in biological media, we examined changes in their size, surface charge, and dissolution in simpler media (i.e., CCM, m(CCM+BSA), mCYS, m(CYS+BSA), mGSH, m(GSH+BSA), ALF, and AGF, see

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• , compared to 6.5 to 13.2 nm for the as-prepared nanoceria. After 75 days of dissolution, the surface charge was −9 mV, compared to the as-prepared nanoceria surface charge of −40 mV, suggesting the loss of the citrate coating. RAW 264.7 cell exposure to the as-prepared solvothermally synthesized nanoceria

• the exposure to partially dissolved nanoceria may be due to the increased surface content of Ce3+ providing antioxidant potential. After dialysis in water, the partially dissolved nanoceria rapidly precipitates from the dispersion, presumably due to the loss of surface citrate and reduced surface

• charge. The particles do not pass through a 0.2 micrometer MWCO filter, suggesting that they were quite large, which may have affected cell uptake. The results illustrate an effect of nanoceria dissolution on its biological identity. Nanoceria reactivity Nanoceria reactivity increased as the content of

Simulation of gas sensing with a triboelectric nanogenerator

• Kaiqin Zhao,
• Hua Gan,
• Huan Li,
• Ziyu Liu and
• Zhiyuan Zhu

Beilstein J. Nanotechnol. 2021, 12, 507–516, doi:10.3762/bjnano.12.41

• area. Further, in order to eliminate the inevitable topological change during the actual movement of the TENG, an air gap was established in COMSOL to construct the two-dimensional model of the TENG. Based on the assumption that the surface charge density of the triboelectric nanogenerator is constant

• materials approach or move away from each other, other substances, such as water vapor, carbon dioxide, and other gases, can pass through the gap. We present a simulation with water vapor under ideal conditions, that is, the surface charge density may be changed during the experiment. A simplified two

• triboelectric materials is helpful for distinguishing different gases. It is noted that water or humidity can degrade the surface charge density of the electrification surfaces in an actual experiment. We will carry out further investigations in the future. Conclusion Simulations of three differently shaped

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• aggregation, physicochemical or biological synthesis methods used, chemical nature of the coating, surface charge, and free Ag+ content. The quality control of AgNPs is necessary to guarantee their suitability for the intended use, reproducibility, efficacy, and low toxicity [146]. Another important point is

Colloidal particle aggregation: mechanism of assembly studied via constructal theory modeling

• Scott C. Bukosky,
• Sukrith Dev,
• Monica S. Allen and
• Jeffery W. Allen

Beilstein J. Nanotechnol. 2021, 12, 413–423, doi:10.3762/bjnano.12.33

• , as well as the particle size, spacing, and surface charge. As a result, these system parameters can be tuned in order to control the balance between the DLVO forces. Tunability, or the ability to direct the movement and assembly of particles into higher-order structures, is important for a wide

• electrolyte ions arrange near the surface of the particles to form an electric double layer, thus screening the surface charge. The characteristic length or “thickness” of this double layer (which is a function of the ion concentration, I) is known as the Debye length, λD, while the surface charge is

Doxorubicin-loaded gold nanorods: a multifunctional chemo-photothermal nanoplatform for cancer management

• Uzma Azeem Awan,
• Abida Raza,
• Shaukat Ali,
• Rida Fatima Saeed and
• Nosheen Akhtar

Beilstein J. Nanotechnol. 2021, 12, 295–303, doi:10.3762/bjnano.12.24

• their surface with PSS. The LSPR peak of the PSS-coated GNRs was slightly redshifted to 783 nm (Figure 1c). The shift of the LSPR peak after PSS coating is due to the side-by-side assembly of the PSS-GNRs [27]. The surface charge of the GNRs changed from strongly positive (+42 mV, due to CTAB presence

• concentration of 10 µg/mL and were stirred overnight in the dark at room temperature. Excess drug was removed by centrifugation at 12,000g for 10 min and the pellet was re-dispersed in 2 mL deionized water. UV–vis spectra of DOX-loaded GNRs were scanned at a wavelength range of 400–1100 nm. The surface charge

Differences in surface chemistry of iron oxide nanoparticles result in different routes of internalization

• Barbora Svitkova,
• Vlasta Zavisova,
• Veronika Nemethova,
• Martina Koneracka,
• Miroslava Kretova,
• Filip Razga,
• Monika Ursinyova and
• Alena Gabelova

Beilstein J. Nanotechnol. 2021, 12, 270–281, doi:10.3762/bjnano.12.22

• carrier, are the most frequently used materials for biomedical applications [17][18][19][20]. The impact of the surface chemistry on the mechanism of nanoparticle uptake has not been sufficiently clarified yet. MNPs with comparable basic physicochemical characteristics (e.g., particle size, surface charge

• surface charge), cell membrane properties (fluidity, type of receptors, and receptor density), and cell type [30][31][32]. For biomedical applications, the optimal size of nanocarriers is in the range of 95–200 nm because of the higher accumulation rate in tumors [33][34]. Spherical nanoparticles (NPs) in

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• phenomenon. However, the results were highly controversial [88][89]. Xu et al. [90] have proposed that the quantification of the surface charge density at different temperature values is a critical method for investigating this phenomenon. This can be readily explored as an effective tool to identify the

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• deposited patches primarily prefer uncovered areas. In addition, the PM gets well oriented in an electric field according to its surface charge. Initially, a drop of 5 µL WT PM suspension was attached to the substrate only and was not in contact with the opposite electrode. While the plate distance was kept

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• surface charge [51]. Positively charged silica particles interact more efficiently with the negatively charged cell membrane than negatively charged particles [45], which can also cause an enhanced uptake [51][52]. This process is supported by the fact that the hydrodynamic diameter of the AHAPS

• Table 1. The dispersion behavior and changes in the surface charge of the samples in various media (ethanol, water, and Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1% glutamine, 1% fungizone, and 1% penicillin) were studied by conducting DLS and ELS

• measurements. The DLS and ZP results are also shown in Table 1. The zeta potential changed from negative to positive after AHAPS functionalization due to the positive surface charge of the amine group in the AHAPS ligand. The zeta potential values of the AHAPS-functionalized samples slightly decreased after