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

• engineering faces a limitation to mimic the architecture of cartilage. Therefore, Janssen et al. used VA–MWCNT micropillars to induce an unidirectional orientation of chondrocytes [137]. The Young’s modulus of the VA–MWCNT micropillars was in the range of the natural ECM of articular cartilage. The

• proliferation of chondrocytes to achieve unidirectional orientation was controllable by optimizing the size and spacing of VA–MWCNT micropillars. Cell attachment, proliferation, and ECM production reportedly were enhanced by micropillars in comparison to the control groups [137]. Apart from carbon nanotubes for

Wet-spinning of magneto-responsive helical chitosan microfibers

• Dorothea Brüggemann,
• Johanna Michel,
• Naiana Suter,
• Matheus Grande de Aguiar and
• Michael Maas

Beilstein J. Nanotechnol. 2020, 11, 991–999, doi:10.3762/bjnano.11.83

• in which freshly-spun alginate fibers containing magnetic nanoparticles were fixed with a magnetized conical tip and rotated around micropillars, acquiring a helical shape with three to four windings [47]. Non-scalable procedures, such as high-temperature synthesis, photolithography or the use of

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• enhancement of the optical emission between 850 and 1400 nm of an ensemble of silicon mono-vacancies (VSi), silicon and carbon divacancies (VCVSi), and nitrogen vacancies (NCVSi) in an n-type 4H-SiC array of micropillars. The micropillars have a length of ca. 4.5 μm and a diameter of ca. 740 nm, and were

• element method simulations. Our study provides the pathway for device design and fabrication with an integrated ultra-bright ensemble of VSi and NCVSi for in vivo imaging and sensing in the infrared. Keywords: color centers; micropillars; proton irradiation; quantum sensing; silicon carbide; vacancy

• for the VSi and the nitrogen vacancy (NCVSi) [36]. Micropillars in other materials have been successfully used as photonics structures designed to improve the photoluminescence performance of quantum dots for strong coupling of the emission with the photonics cavity, high photon-extraction efficiency

Pull-off and friction forces of micropatterned elastomers on soft substrates: the effects of pattern length scale and stiffness

• Peter van Assenbergh,
• Marike Fokker,
• Julian Langowski,
• Jan van Esch,
• Marleen Kamperman and
• Dimitra Dodou

Beilstein J. Nanotechnol. 2019, 10, 79–94, doi:10.3762/bjnano.10.8

• micropillars of 100 μm height and a stem diameter of 60 μm, terminated with a thin (2 μm) disc of 40 μm in diameter [11]. These so-called mushroom-shaped micropillars generated higher pull-off forces than flat-punch micropillars, a phenomenon attributed to a higher adaptability to substrate roughness due to

• -shaped micropillars detaches via a local thin-film peeling mechanism, multiple peeling fronts are present throughout the micropattern [14]. This splitting-up of the peeling front in multiple smaller fronts results in a drastic increase in peeling line length, and therefore in high pull-off and friction

• forces [14][15]. Heepe et al. investigated the significance of suction forces during detachment of mushroom-shaped micropillars [16], considering that the inside-towards-outside detachment mechanism gives rise to a low-pressure enclosed space in the center of the terminal disc during detachment. These

The effect of flexible joint-like elements on the adhesive performance of nature-inspired bent mushroom-like fibers

• Elliot Geikowsky,
• Serdar Gorumlu and
• Burak Aksak

Beilstein J. Nanotechnol. 2018, 9, 2893–2905, doi:10.3762/bjnano.9.268

• of the tip rather than the stalk played an important role in obtaining directional properties. In the work by Wang [18], a method to produce slanted functionally gradient micropillars was proposed, whereby a magnetically assisted technique was applied to manage the compliance of the slanted fiber. By

Review on optofluidic microreactors for artificial photosynthesis

• Xiaowen Huang,
• Jianchun Wang,
• Tenghao Li,
• Jianmei Wang,
• Min Xu,
• Weixing Yu,
• Abdel El Abed and
• Xuming Zhang

Beilstein J. Nanotechnol. 2018, 9, 30–41, doi:10.3762/bjnano.9.5

• hydrogen generation due to a limited active surface area and low mass transfer rate. In another work, Wang et al. proposed an optofluidic microreactor with staggered micropillars in the reaction microchamber [74], as shown in Figure 4. Such structure has four favorable features: (1) enlarged surface area

• . Adapted from [68], copyright 2014 Wiley-VCH Verlag GmbH & Co. KGaA. PS stands for photosystem. (A) Schematic of the high-surface-area optofluidic microreactor with micropillar structure. (B) Staggered micropillars in the reaction chamber. (C) Fabrication procedure of the optofluidic microreactor with the

• catalyst-coated micropillars. Reprint with the permission from [74], copyright 2014 Elsevier Ltd. (A) Schematic of the high-surface-area optofluidic microreactor with micro-grooved structure. (B) Fabrication procedure of the optofluidic microreactor with the catalysts on the PDMS substrate. Adapted from

Silicon microgrooves for contact guidance of human aortic endothelial cells

• Sara Fernández-Castillejo,
• Pilar Formentín,
• Úrsula Catalán,
• Josep Pallarès,
• Lluís F. Marsal and
• Rosa Solà

Beilstein J. Nanotechnol. 2017, 8, 675–681, doi:10.3762/bjnano.8.72

• , macroporous and micropillars, to study the effect of topography on the behaviour of endothelial cells. Collagen was found to stimulate cell adhesion and promote an enhanced cell attachment [32][33]. Herein, to mimic the elongated endothelium in natural lineal vessels, human aortic endothelial cells (HAECs

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

• Alexandra M. Greiner,
• Adria Sales,
• Hao Chen,
• Sarah A. Biela,
• Dieter Kaufmann and
• Ralf Kemkemer

Beilstein J. Nanotechnol. 2016, 7, 1620–1641, doi:10.3762/bjnano.7.155

• chromosomes repositioning [276]. Some different gene regulations were attributed to these changes in chromosomes positions [276]. In a different work, a dramatic drop of SMC proliferation on micropillars was reported and was argued that the deformation of the nuclear lamin was responsible of this change in

Scale effects of nanomechanical properties and deformation behavior of Au nanoparticle and thin film using depth sensing nanoindentation

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2014, 5, 822–836, doi:10.3762/bjnano.5.94

• reduced properties. Jang and Greer [6], for example reported for Ni micropillars (0.1–2.5 µm) under compression, that the yield strength was reduced as the diameter was decreased with a critical grain size of 60 nm. Of particular interest are cases in which properties are enhanced leading to the ‘smaller

• ‘smaller is stronger’ phenomenon. In compression studies involving Au (0.4–7.5 µm) micropillars a similar observation was made and higher yield strengths were observed compared to bulk with decreasing micropillar diameter [19]. For a thorough review, see Palacio and Bhushan [24]. The increase in yield