Elasticity, an often-overseen parameter in the development of nanoscale drug delivery systems

• Agnes-Valencia Weiss and
• Marc Schneider

Beilstein J. Nanotechnol. 2023, 14, 1149–1156, doi:10.3762/bjnano.14.95

• properties of drug carriers. Keywords: atomic force microscopy; drug delivery; elasticity; mechanical properties; nanomedicine; nanoparticles; stiffness measurement; tissue/body distribution; Introduction Drug delivery systems are developed with the aim to transport a given drug to the site of action

• properties of nanoparticles, it nearly impossible to compare studies from different labs and pick a value to aim for during the development of a drug delivery system. This is due to the variety of possibilities to examine and express the mechanical properties of these systems (e.g., stiffness, elasticity

• particles showed better cellular uptake if no mucus layer was present. In contrast to this, the cellular uptake for semielastic particles was not significantly affected by the presence of a mucus layer [38]. Liposomes with PLGA cores were used by Yu et al. to increase the stiffness in combination with

Spatial mapping of photovoltage and light-induced displacement of on-chip coupled piezo/photodiodes by Kelvin probe force microscopy under modulated illumination

• Zeinab Eftekhari,
• Nasim Rezaei,
• Hidde Stokkel,
• Jian-Yao Zheng,
• Andrea Cerreta,
• Ilka Hermes,
• Minh Nguyen,
• Guus Rijnders and
• Rebecca Saive

Beilstein J. Nanotechnol. 2023, 14, 1059–1067, doi:10.3762/bjnano.14.87

• -right corner of each color map. The expected bulging shape is observed for samples B and C shown in Figure 4b and c, respectively. The smallest sample (D) nonetheless shows a relatively uniform displacement, which can arise from the increased stiffness of the membrane as a result of its minuscule

Exploring internal structures and properties of terpolymer fibers via real-space characterizations

• Michael R. Roenbeck and
• Kenneth E. Strawhecker

Beilstein J. Nanotechnol. 2023, 14, 1004–1017, doi:10.3762/bjnano.14.83

• nano- and microscale topography, stiffness, and transverse elastic modulus (ET) maps of internal structural features and local mechanical responses in real space. (See the Experimental section for additional details.) As Technora® has often been compared to Kevlar® K29 fibers, we focus further on

• ®, both the topography and stiffness maps (Figure 2) revealed a consistent microstructure across the fiber diameter at this length scale. Complementing topography and stiffness maps, lateral line profiles (e.g., dashed line, Figure 2a) quantified both topography and stiffness variations across the

• diameter. Topography and stiffness (Figure 2c) were remarkably uniform across the diameter as well. Only two notable features deviate from our consistent topography and stiffness measurements: (i) slopes from the outer edges inward and (ii) a sudden jump at a lateral position of ca. 5 μm. It should be

Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

• Akeem Adeyemi Oladipo,
• Saba Derakhshan Oskouei and
• Mustafa Gazi

Beilstein J. Nanotechnol. 2023, 14, 631–673, doi:10.3762/bjnano.14.52

• linkers have been used, many of which contain rigid backbones that have been substituted with multiple carboxylate groups for metal coordination. As linkers in MOFs, organic compounds with fused π rings and strong conjugation are frequently used. Due to their stiffness, they are frequently both very

Suspension feeding in Copepoda (Crustacea) – a numerical model of setae acting in concert

• Alexander E. Filippov,
• Wencke Krings and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2023, 14, 603–615, doi:10.3762/bjnano.14.50

• of the process, which allows us to make some conclusions about the efficiency of the feeding process at different properties of the setae. The segments were provided with longitudinal (K∥) and transverse (K⟂) stiffness, K∥ = K⟂. The transverse stiffness tends to hold the angle between the neighboring

• segments close to 180°. According to the goals of this study, we varied the stiffness from segment to segment depending on the hypothetical particular structure. A deformation of the setae produced elastic forces proportional to the seta stiffness. The forces were described by the following equations (see

Transferability of interatomic potentials for silicene

• Marcin Maździarz

Beilstein J. Nanotechnol. 2023, 14, 574–585, doi:10.3762/bjnano.14.48

• symmetry implies isotropy of the stiffness tensor, that is, there are only two distinct elastic constants and they satisfy, in Voigt notation, such conditions that C11 = C22, C33 = (C11 − C12)/2. Structural and mechanical characteristics that were determined from DFT computations, namely lattice parameters

Nanoarchitectonics to entrap living cells in silica-based systems: encapsulations with yolk–shell and sepiolite nanomaterials

• Celia Martín-Morales,
• Jorge Fernández-Méndez,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2023, 14, 522–534, doi:10.3762/bjnano.14.43

• as stiffness and abrasion resistance to help the growth of the entrapped cells. In addition, control of the porosity of the involved inorganic materials is key to control efficiently the exchange of metabolites and nutrients with the surrounding environment. In this context, the present contribution

Laser-processed antiadhesive bionic combs for handling nanofibers inspired by nanostructures on the legs of cribellate spiders

• Sebastian Lifka,
• Kristóf Harsányi,
• Erich Baumgartner,
• Lukas Pichler,
• Dariya Baiko,
• Karsten Wasmuth,
• Johannes Heitz,
• Marco Meyer,
• Anna-Christin Joel,
• Jörn Bonse and
• Werner Baumgartner

Beilstein J. Nanotechnol. 2022, 13, 1268–1283, doi:10.3762/bjnano.13.105

• the case for these reasons: (1) Due to the smaller radius, the fiber also becomes softer. In consequence, the easier deflection can increase the contact area, resulting in larger forces. The van der Waals force is proportional to the root of the radius, μ ∼ √R, and the materials stiffness, expressed

• surface. The point of detachment of the fiber from the surface is defined as the detachment point x0. This point can parametrize the curve and is initially assumed to be known. The fiber is assumed to have a certain bending stiffness and, thus, it can be modelled according to the linear elastic (Hookean

• parameters and some constants such as the Hamaker constant and the elastic modulus of the fiber. These free parameters are the amplitude a and the spatial period Λ = 2λ of the sinusoidal surface, as well as the bending stiffness and the radius of the fiber in the case of S = 0. While finding the minimum of

Microneedle-based ocular drug delivery systems – recent advances and challenges

• Piotr Gadziński,
• Anna Froelich,
• Monika Wojtyłko,
• Antoni Białek,
• Julia Krysztofiak and
• Tomasz Osmałek

Beilstein J. Nanotechnol. 2022, 13, 1167–1184, doi:10.3762/bjnano.13.98

• are usually prepared from ceramic materials, silicon, or metal, they display higher stiffness than polymer-based systems. The risk of clogging the internal canals of the needles upon application is mentioned in the literature as a possible drawback of these systems [142]. Dissolving microneedles are

A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy

• Hao Liu,
• Zuned Ahmed,
• Sasa Vranjkovic,
• Manfred Parschau,
• Andrada-Oana Mandru and
• Hans J. Hug

Beilstein J. Nanotechnol. 2022, 13, 1120–1140, doi:10.3762/bjnano.13.95

• obtained by using cantilever-based AFM instruments, where cantilevers with stiffness of the order of few tens of newtons per meter were oscillated with amplitudes of a few nanometers [4][5][6][7]. Atomic resolution is achieved if the tip–sample distance is sufficiently reduced, such that short-ranged

• macroscopic wire tip to the free prong. Compared to the typically used microscopic AFM cantilevers, the tuning fork sensor has a rather high stiffness, k ≈ 2 kN/m. This facilitates AFM operation with small oscillation amplitudes (A < 100 pm) because a snap-to-contact or instabilities of the phase-locked loop

• tip–sample interaction. However, because of the macroscopic size of the tuning fork, the high stiffness of the sensor goes together with a low resonance frequency typically around 30 kHz. This substantially limits the minimally measurable tip–sample interaction force gradients such that very small AFM

Biomimetic chitosan with biocomposite nanomaterials for bone tissue repair and regeneration

• Se-Kwon Kim,
• Sesha Subramanian Murugan,
• Pandurang Appana Dalavi,
• Sebanti Gupta,
• Sukumaran Anil,
• Gi Hun Seong and
• Jayachandran Venkatesan

Beilstein J. Nanotechnol. 2022, 13, 1051–1067, doi:10.3762/bjnano.13.92

• phosphatase, bone morphogenic protein, runt-related transcription factor-2, bone sialoprotein, and osteocalcin. In vitro and in vivo studies highlight the scientific findings of antibacterial activity, tissue integration, stiffness, mechanical strength, and degradation behaviour of composite materials for

• nanosized hydroxyapatite crystals with connective collagen fibrils [27]. The bone possesses a unique combination of strength and stiffness, and it has excellent compressive strength and tensile strength due to the attribution of deep nanostructures of inorganic and organic components. Human bones are

• in order to achieve vascularization and rapid tissue growth. To achieve tissue scaffold maturation, research into the development of scaffolds with supplied growth factors, programmable degradation rate, and good mechanical stiffness with improved bioactivity is required. Furthermore, mathematical

Micro-structures, nanomechanical properties and flight performance of three beetles with different folding ratios

• Jiyu Sun,
• Pengpeng Li,
• Yongwei Yan,
• Fa Song,
• Nuo Xu and
• Zhijun Zhang

Beilstein J. Nanotechnol. 2022, 13, 845–856, doi:10.3762/bjnano.13.75

• contact depth. S is the contact stiffness. A Berkovich tip with a tip radius of approximately 100 nm was used for the tests. In order to study the effect of nanomechanical properties of different veins on the lift of the beetle hind wings, the same location of the same vein of three beetles was selected

Temperature and chemical effects on the interfacial energy between a Ga–In–Sn eutectic liquid alloy and nanoscopic asperities

• Yujin Han,
• Pierre-Marie Thebault,
• Corentin Audes,
• Xuelin Wang,
• Haiwoong Park,
• Jian-Zhong Jiang and
• Arnaud Caron

Beilstein J. Nanotechnol. 2022, 13, 817–827, doi:10.3762/bjnano.13.72

• force–distance curve with each cantilever on a quartz glass sample (manufactured by Goodfellow, United Kingdom) and extracting its slope in the range of repulsive forces. Subsequently, we determined the bending stiffness Cn of each cantilever by analyzing its thermal noise vibration [18]. After

• forward and backward direction by multiplying the height signal with the bending stiffness. We observe a hysteresis for both normal and lateral forces, which indicates a dragging force opposing the sliding motion of the tip. The observation of hysteresis for the lateral force is common on solid surfaces

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

• varied providing colloidally stable and soft particles. This is in contrast to the aforementioned investigations, where the particle stiffness could not be influenced by the preparation, but only increased through particle aging after a storage period. Quantitative imaging (QI™-mode) was used for the

Fabrication and testing of polymer microneedles for transdermal drug delivery

• Vahid Ebrahiminejad,
• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55

• considerable potential for medical applications such as transdermal drug delivery, point-of-care diagnostics, and vaccination. These miniature microdevices should successfully pierce the skin tissues while having enough stiffness to withstand the forces imposed by penetration. Developing low-cost and simple

• porcine back skin. Pig skin possesses similarities to human skin [30]; excised dorsal (back) skin has greater stiffness compared to other skin locations [31]. The experimental results include the MN mechanical strength, mechanisms of MN damage, skin insertion force, and margin of safety prediction, along

Quantitative dynamic force microscopy with inclined tip oscillation

• Philipp Rahe,
• Daniel Heile,
• Reinhard Olbrich and
• Michael Reichling

Beilstein J. Nanotechnol. 2022, 13, 610–619, doi:10.3762/bjnano.13.53

• straight tip sampling path with arbitrary oscillation direction. The starting point is the differential equation describing the displacement q(t) in presence of the tip–sample force field and excitation force as follows with the sensor parameters fundamental eigenfrequency f0, modal sensor stiffness k0

Effects of substrate stiffness on the viscoelasticity and migration of prostate cancer cells examined by atomic force microscopy

• Xiaoqiong Tang,
• Yan Zhang,
• Jiangbing Mao,
• Yuhua Wang,
• Zhenghong Zhang,
• Zhengchao Wang and
• Hongqin Yang

Beilstein J. Nanotechnol. 2022, 13, 560–569, doi:10.3762/bjnano.13.47

• Fujian Provincial Key Laboratory for Developmental Biology and Neurosciences, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China 10.3762/bjnano.13.47 Abstract The stiffness of the extracellular matrix of tumour cells plays a key role in tumour cell metastasis. However, it is

• unclear how mechanical properties regulate the cellular response to the environmental matrix. In this study, atomic force microscopy (AFM) and laser confocal imaging were used to qualitatively evaluate the relationship between substrate stiffness and migration of prostate cancer (PCa) cells. Cells

• substrate stiffness and the mechanical properties of cells in prostate tumour metastasis, providing a basis for understanding the changes in the biomechanical properties at a single-cell level. Keywords: actin cytoskeleton; atomic force microscopy; migration; prostate cancer cells; substrate stiffness

Investigation of electron-induced cross-linking of self-assembled monolayers by scanning tunneling microscopy

• Patrick Stohmann,
• Sascha Koch,
• Yang Yang,
• Christopher David Kaiser,
• Julian Ehrens,
• Jürgen Schnack,
• Niklas Biere,
• Dario Anselmetti,
• Armin Gölzhäuser and
• Xianghui Zhang

Beilstein J. Nanotechnol. 2022, 13, 462–471, doi:10.3762/bjnano.13.39

• create ultrathin carbon nanomembranes (CNMs) [25][26]. Depending on the precursor molecules and the exposure conditions, thickness [27], mechanical stiffness [28], and electronic transport characteristics [29][30] of CNMs can be tailored. Carbon nanomembranes have been applied as electron microscopy

Effect of sample treatment on the elastic modulus of locust cuticle obtained by nanoindentation

• Chuchu Li,
• Stanislav N. Gorb and
• Hamed Rajabi

Beilstein J. Nanotechnol. 2022, 13, 404–410, doi:10.3762/bjnano.13.33

• ). The specimens were indented using a SA2 Nanoindenter (MTS Nano Instruments, Oak Ridge, TN, USA) equipped with a Berkovich diamond tip. The elastic modulus of the specimens was measured using the continuous stiffness measurement (CSM) technique. CSM is a well-established technique for obtaining the

• elastic modulus continuously as a function of the indentation depth (Figure 1d). The method involves applying a dynamic load on the top of the static load while loading. The dynamic unloading part is then used to measure the stiffness, which is further processed to calculate the elastic modulus of the

• period of time. Storing the specimens in water can also cause overhydration. The increased amount of water can result in swelling of specimens, which can consequently reduce the cuticle stiffness [9][15]. Here, we suggest a new protocol that can be used to measure the elastic modulus of cuticle specimens

Micro- and nanotechnology in biomedical engineering for cartilage tissue regeneration in osteoarthritis

• Zahra Nabizadeh,
• Mahmoud Nasrollahzadeh,
• Hamed Daemi,
• Mohamadreza Baghaban Eslaminejad,
• Ali Akbar Shabani,
• Mehdi Dadashpour,
• Majid Mirmohammadkhani and
• Davood Nasrabadi

Beilstein J. Nanotechnol. 2022, 13, 363–389, doi:10.3762/bjnano.13.31

• cues, and surface stiffness in osteochondral tissue differentiation and engineering is discussed with examples from recent studies that highlight their importance in tissue engineering applications. 2 Articular cartilage biology The composition and complex structure of articular cartilage need to be

Systematic studies into uniform synthetic protein nanoparticles

• Nahal Habibi,
• Ava Mauser,
• Jeffery E. Raymond and
• Joerg Lahann

Beilstein J. Nanotechnol. 2022, 13, 274–283, doi:10.3762/bjnano.13.22

• response at the cellular level. Several studies [28][29][30] have shown that considerations such as aspect ratio, stiffness/deformability, and particle surface roughness (deviation of circularity) can have a comparable impact on cellular uptake and/or endosomal escape. Hence, it is important to incorporate

Theoretical understanding of electronic and mechanical properties of 1T′ transition metal dichalcogenide crystals

• Seyedeh Alieh Kazemi,
• Sadegh Imani Yengejeh,
• Vei Wang,
• William Wen and
• Yun Wang

Beilstein J. Nanotechnol. 2022, 13, 160–171, doi:10.3762/bjnano.13.11

• and MoS2 structures display larger values. Since bulk and shear moduli are directly related to the mechanical stiffness of the materials, their Young’s moduli exhibit a similar trend as well. WS2 is the TMD most resistant to compression amongst all systems investigated, with B and Y values of 50 and

Nanoscale friction and wear of a polymer coated with graphene

• Robin Vacher and
• Astrid S. de Wijn

Beilstein J. Nanotechnol. 2022, 13, 63–73, doi:10.3762/bjnano.13.4

• the stiffness and r0 = 2.6 Å is the equilibrium bond length. The bending potential is approximated by an angular potential described in a table format. For graphene we use the AIREBO-M potential developed by O’Connor and co-workers [31]. It is an empirical many-body potential that is directly

Polarity in cuticular ridge development and insect attachment on leaf surfaces of Schismatoglottis calyptrata (Araceae)

• Venkata A. Surapaneni,
• Tobias Aust,
• Thomas Speck and
• Marc Thielen

Beilstein J. Nanotechnol. 2021, 12, 1326–1338, doi:10.3762/bjnano.12.98

• ][41][42]. Moreover, the amount of polysaccharide and cutin components present in the cuticle probably influences the stiffness and elastic behavior of the cuticle–cell wall interface [43] and certainly affects ridge formation. The thickened cuticle provides structural support to the growing epidermal

Cantilever signature of tip detachment during contact resonance AFM

• Devin Kalafut,
• Ryan Wagner,
• Maria Jose Cadena,
• Anil Bajaj and
• Arvind Raman

Beilstein J. Nanotechnol. 2021, 12, 1286–1296, doi:10.3762/bjnano.12.96

• thermal method [33] was then used to calculate the static cantilever bending stiffness. To study the process of tip detachment, we swept drive frequencies (low to high, then high to low) at selected drive amplitudes near the first contact resonance frequency of the cantilever–sample system. The cantilever

• step is pertinent not only to parameter identification, but also the dynamic simulations. Measurements of the resonance frequencies for both the free and contact cases allow us to identify critical stiffness quantities required for converting raw experimental output into physical quantities. The

• solution valid for both the first and second contact modes, thus determining kratio and γ for the system. We define the cantilever spring constant as [1]: and the first free vibrating mode stiffness as [40]: allowing us to solve for kcantilever and the flexural rigidity EI. Combining these with previous