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

• matrices for cell transplantation in the late 1980s [18], there have been numerous developments in the design and fabrication of bioinspired and smart biomaterials with improved potential of TE as a regenerative medicine approach. The development of hydrogel-based scaffolds for regenerative medicine

• . Micro- and nanostructures including microspheres, NPs, nanofibers, nanotubes, and nanofilms have been designed to construct new scaffolds and or incorporated into the hydrogel network to provide a controlled release or enhanced mechanical characteristics. Many of these substructures are widely used for

• incorporated them into an HA hydrogel. The structures showed superior mechanical properties and longer release of growth factor for more than six days compared to both a hydrogel scaffold loaded directly with TGF-β3 and one with non-coated microspheres. Incorporation of the TGF-β3 loaded microsphere into an

Self-assembly of amino acids toward functional biomaterials

• Huan Ren,
• Lifang Wu,
• Lina Tan,
• Yanni Bao,
• Yuchen Ma,
• Yong Jin and
• Qianli Zou

Beilstein J. Nanotechnol. 2021, 12, 1140–1150, doi:10.3762/bjnano.12.85

• strategy can provide different functions for amino acid assembly. Fmoc-phenylalanine and Fmoc-leucine were co-assembled, with Fmoc-phenylalanine as the hydrocoagulant and Fmoc-leucine as the antimicrobial unit. The resulting hydrogel selectively killed Staphylococcus aureus by breaking the cell wall and

• membrane and had good biocompatibility. After 20 h of incubation, approximately 95% of Staphylococcus aureus bacterial proliferation was effectively inhibited [46]. A novel supramolecular self-assembled hydrogel was prepared by mixing Fmoc-ʟ-phenylalanine (Fmoc-ʟ-Phe) with oligo(thiophene ethynylene)-ᴅ

• with drugs to play different therapeutic effects as drug delivery carriers. The encapsulation of the antibiotic aztreonam (ATZ) in the Fmoc-phenylalanine (Fmoc-F) hydrogel expands the antibacterial range of Fmoc-F, which can continuously release ATZ and Fmoc-F in the wound [48]. The AZT encapsulated

An overview of microneedle applications, materials, and fabrication methods

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

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• ) [15]. Doses sustained over time could be achieved using slowly dissolving structures or through stepwise bolus using multiple patches. Incorporation of hydrogel reservoirs in microneedle patches is a plausible alternative to conventional drug pump delivery systems and there has been some relevant work

• on hydrogel-forming polymer microneedles [16][17][18]. Microneedle patch technology has the potential to overcome the challenges involved in mass vaccination against COVID-19 across the world and has already shown promising achievements in delivering lyophilised or liquid formulation-based vaccines

• example using porous silicon, is one possible solution [39][40][41]. However, a hydrogel reservoir which could be much larger than the microneedle array seems a better option, since it can swell to achieve greater load which can be released under finger pressure in combination with microfluidic

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 magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• the design of various magnetic MNRs. Kim et al. [64] proposed a hydrogel microrobot based on the combination of an electroactive hydrogel and MNPs. Electroactive hydrogels are usually made of a single hydrogel [65]. They respond to electric fields and produce mechanical motion in an electrolyte [66

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• examples in which the photothermal effect was applied on gold nanomaterials (nanorods, nanoshells, silk hydrogel containing spherical gold nanoparticles) to induce antibacterial activity were summarized in a review [51]. Later on, in 2017, another review highlighted the advances in the gold nanoparticle

• heating of gold nanoparticles embedded in an injectable silk protein hydrogel was one of the first examples that used this approach [65]. The NIR laser irradiation at 528 nm for 15 min (450 mW) elevated the maximum gel temperature to 59 °C. The in vivo studies demonstrated a sufficient bacterial reduction

• . The local photothermal effect triggered by the NIR irradiation of PVA-GNS films was highly efficient in eliminating E. coli bacteria, as shown in Figure 4. In a very recent study, the antimicrobial activity of a chitosan-based hydrogel with embedded gold nanorods under low-power (200 mW) diode laser

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

• sulfonic groups followed by accumulation of silver ions in the generated hydrogel layer. Then, the silver ions were reduced using sodium borohydride, which resulted in the formation of silver nanoparticles. It has been demonstrated that during the reduction process also the sulfonic groups in the polymer

• modified with sulfonic groups followed by accumulation of silver ions in the formed hydrogel layer. Then, the silver ions are reduced using sodium borohydride. The reaction proceeds concurrently within the gel layers of the particles and in the bulk of the solution. However, after completion of the

• beads were incubated with silver ions with the intention that, through Coulomb interactions between anionic sulfonic groups and silver ions, the cations will accumulate in the hydrogel shell. Then, the reducing agent (sodium borohydride) was added to the reaction mixture to reduce the incorporated metal

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

• , concentration, intensity of mixing and agitation. These templates are biocompatible, easy to produce, and dissolvable by EDTA. Although crystallization processes cannot be controlled to provide uniform and homogenous cores, this matrix provides an efficient way for encapsulation. Additionally, hydrogel-based

• microparticles (10–200 µm) fabricated via stop flow lithography have emerged as useful templates to form custom-shaped and flexible microcapsules of poly-ʟ-lysine (PLL) [36]. The shell was formed by diffusion of PLL into an oppositely charged hydrogel matrix, enabling an easy surface modification that can be

• ]. First stimuli responsive supramolecular hydrogel films based on β-cyclodextrin and adamantyl-modified chitosan derivatives have demonstrated a reversible swelling and shrinking upon changing the ionic strength [62]. At high ionic strength, the decrease in the electrostatic repulsive effect between the

Poly(1-vinylimidazole) polyplexes as novel therapeutic gene carriers for lung cancer therapy

• Gayathri Kandasamy,
• Elena N. Danilovtseva,
• Vadim V. Annenkov and
• Uma Maheswari Krishnan

Beilstein J. Nanotechnol. 2020, 11, 354–369, doi:10.3762/bjnano.11.26

• to the proton-donating nature of the imidazole moiety have been demonstrated in [9]. Imidazole-based hydrogel films demonstrated excellent anti-microbial effects [10]. A copolymer of poly(acrylamide) and poly(vinylimidazole) was used as a hydrophilic matrix to disperse multiwalled carbon nanotubes

• and the enzyme glucose oxidase for glucose-sensing applications [11]. A hydrogel of xanthan gum and poly(1-vinylimidazole) was recently explored for protein encapsulation and delivery. The system exerted no toxic effects on cells and maintained the functionality of the protein [12]. A pyrrole

Understanding nanoparticle flow with a new in vitro experimental and computational approach using hydrogel channels

• Armel Boutchuen,
• Dell Zimmerman,
• Abdollah Arabshahi,
• John Melnyczuk and
• Soubantika Palchoudhury

Beilstein J. Nanotechnol. 2020, 11, 296–309, doi:10.3762/bjnano.11.22

• scaffold materials for the 3D bioprinting of biomimetic structures [38][39]. Therefore, we chose pHEMA hydrogels to build straight cylindrical channels mimicking sections of human vasculature for our experimental investigation of NP flow. In addition, we aimed to synthesize the hydrogel flow channels via a

• new, facile, and cost-effective approach. Here, we report a combined experimental and computational technique to serve as an in vitro assessment of the flow of NPs using novel pHEMA hydrogel channels as the biomimetic flow path. The flow of NPs was experimentally investigated with different iron oxide

• NP formulations synthesized via a facile method for monitoring the velocity and mass loss of NPs through the hydrogel channels. The experimental flow of NPs was compared with computational predictions for a reliable assessment of NP flow through soft vascular mimics. An in silico CFD method using the

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• of CA is drastically reduced compared to that of the precursor cellulose hydrogel and aerogel. The network of intertwined nanofibers of CA shown in Figure 2a was maintained from the cellulose aerogel (Figure S2, Supporting Information File 1). The diameter of the nanofibers was about 20–50 nm. The

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

• incubation for several days. However, an increase in oligoadenylic acid chain length resulted in changes in hydrogel color and rigidity. Metal–base pair interactions-guided design of DNA nanoarchitectures Metal–base pair interaction-driven molecular architectonics are one of the major alternatives to

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

• and the biodegradability of the hydrogel. In this paper, PASP cross-linked with cystamine (CYS) and lysine-methylester (LYS) was introduced as fully amino acid-based polymer hydrogel. Gels were synthesized employing six different ratios of CYS and LYS. The pH dependent swelling degree and the

• reductive conditions resulted in an increased drug release due to the cleavage of disulfide bridges in the hydrogels. Consequently, these hydrogels provide new possibilities in the fields of both tissue engineering and controlled drug delivery. Keywords: biocompatibility; cystamine; hydrogel; lysine; poly

• (amino acid)s [28][29]. The effect of poly-ʟ-lysine, which has a cationic character, on the cell behavior has been widely studied in the field of tissue engineering [30][31], while among the anionic poly(amino acid)s, poly(glutamic acid) is typically used for the development of hydrogel scaffolds [32

Integration of sharp silicon nitride tips into high-speed SU8 cantilevers in a batch fabrication process

• Nahid Hosseini,
• Matthias Neuenschwander,
• Oliver Peric,
• Santiago H. Andany,
• Jonathan D. Adams and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2019, 10, 2357–2363, doi:10.3762/bjnano.10.226

• blunt tips (the tip radius increased by an order of magnitude). Lee et al. have shown that hydrogel AFM cantilevers fabricated by replica moulding and UV curing have great potential for tuning the mechanical properties of the tip, its shape and the surface functionalization [26]. However, the

• fabrication of hydrogel probes requires processes that involve individual alignment and bonding [27]. The present work aims to overcome the primary limitation of polymer AFM cantilevers, namely the poor wear rate of polymer tips, by integrating a tip element made of a traditional tip material. The main

Microfluidics as tool to prepare size-tunable PLGA nanoparticles with high curcumin encapsulation for efficient mucus penetration

• Nashrawan Lababidi,
• Valentin Sigal,
• Aljoscha Koenneke,
• Konrad Schwarzkopf,
• Andreas Manz and
• Marc Schneider

Beilstein J. Nanotechnol. 2019, 10, 2280–2293, doi:10.3762/bjnano.10.220

• mucus. Drug carrier systems such as nanoparticles (NPs) require proper surface chemistry and small size to ensure their permeability through the hydrogel-like systems. We have employed a microfluidic system to fabricate poly(lactic-co-glycolic acid) (PLGA) nanoparticles coated with a muco-penetrating

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• important targets in biosensor technology. Someya and co-workers developed a highly flexible organic amplifier to detect weak biosignals [107]. A highly conductive biocompatible gel composite made from multiwalled carbon nanotubes and aqueous hydrogel was integrated into a two-dimensional organic amplifier

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

• describes the preparation and characterization of a new type of core–shell nanoparticle in which the structure consists of a hydrogel core encapsulated within a porous silver shell. The thermo-responsive hydrogel cores were prepared by surfactant-free emulsion polymerization of a selected mixture of N

• -isopropylacrylamide (NIPAM) and acrylic acid (AAc). The hydrogel cores were then encased within either a porous or complete silver shell for which the localized surface plasmon resonance (LSPR) extends from visible to near-infrared (NIR) wavelengths (i.e., λmax varies from 550 to 1050 nm, depending on the porosity

• ), allowing for reversible contraction and swelling of the hydrogel via photothermal heating of the surrounding silver shell. Given that NIR light can pass through tissue, and the silver shell is porous, this system can serve as a platform for the smart delivery of payloads stored within the hydrogel core

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

• -assembly of cyclic dipeptides results in highly robust hydrogels which can be applied for electrochemical applications such as electrochemical supercapacitors. Keywords: crystalline hydrogel; cyclic dipeptide; electrochemical supercapacitors; nanoarchitectonics; self-assembly; Introduction On account of

• hydrogel with crystal features and close-knit three-dimensional network structures. Importantly, the C-WY hydrogel exhibited adjustable rheological properties, excellent stability, and high tolerance under various conditions, including in the presence of charged biopolymers (poly-ʟ-lysine (PLL), alginate

• (ALG), hyaluronic acid (HA)), extreme acid/base environments, and thermal conditions. Owing to the robustness of the hydrogel, the material also showed excellent performance as an electrochemical supercapacitor. Hence, self-assembled CDP hydrogels are promising for applications in complex and harsh

A silver-nanoparticle/cellulose-nanofiber composite as a highly effective substrate for surface-enhanced Raman spectroscopy

• Yongxin Lu,
• Yan Luo,
• Zehao Lin and
• Jianguo Huang

Beilstein J. Nanotechnol. 2019, 10, 1270–1279, doi:10.3762/bjnano.10.126

• bacterial nanocellulose adsorbed with gold nanoparticles in the form of a hydrogel had a detection limit of 1 × 10−9 M for R6G [54], the Au–Ag bimetallic microfluidic SERS sensor had a detection limit of 1 × 10−13 M for the same analyte [64]; and a detection limit of 1 × 10−6 M was offered by a hybrid

Wearable, stable, highly sensitive hydrogel–graphene strain sensors

• Jian Lv,
• Chuncai Kong,
• Chao Yang,
• Lu Yin,
• Itthipon Jeerapan,
• Fangzhao Pu,
• Xiaojing Zhang,
• Sen Yang and
• Zhimao Yang

Beilstein J. Nanotechnol. 2019, 10, 475–480, doi:10.3762/bjnano.10.47

• 21500, P. R. China Research institute of Xi'an Jiaotong University, Hangzhou, Zhejiang, 311215, P. R. China 10.3762/bjnano.10.47 Abstract A stable and highly sensitive graphene/hydrogel strain sensor is designed by introducing glycerol as a co-solvent in the formation of a hydrogel substrate and then

• casting a graphene solution onto the hydrogel in a simple, two-step method. This hydrogel-based strain sensor can effectively retain water in the polymer network due to the formation of strong hydrogen bonding between glycerol and water. The addition of glycerol not only enhances the stability of the

• hydrogel over a wider temperature range, but also increases the stretchability of the hydrogel from 800% to 2000%. The enhanced sensitivity can be attributed to the graphene film, whereby the graphene flakes redistribute to optimize the contact area under different strains. The careful design enables this

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

• with 10% (w/v) PVA hydrogel. In a PVA gel, crosslinks between chains are formed by hydrogen bonding between hydroxyl side groups. We used hydrolyzed PVA, because by additional hydrolysis, acetate side groups in the polymer are turned into hydroxyl groups, and crosslink formation is promoted. Subjecting

• PVA to freeze–thaw cycles further stiffens the hydrogel by growing local crystalline regions that act as network junctions [46]. We prepared substrates of two stiffness degrees, by subjecting PVA to two or three freeze–thaw cycles

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

• hydrogel (rGH). The 3D macrostructures of rGH enhanced the accessible surface area and possessed highly porous structures with a pore size distribution of several micrometers, which enabled the use of the composite for the fast adsorption of Cr(VI) through π–π interactions and a nonporous surface

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

• Błażej Scheibe,
• Radosław Mrówczyński,
• Natalia Michalak,
• Karol Załęski,
• Michał Matczak,
• Mateusz Kempiński,
• Zuzanna Pietralik,
• Mikołaj Lewandowski,
• Stefan Jurga and
• Feliks Stobiecki

Beilstein J. Nanotechnol. 2018, 9, 591–601, doi:10.3762/bjnano.9.55

• -forming nanomaterials, as it allows obtaining three-dimensional highly porous structures, characterized by low density and high specific surface area [2][3][4][5]. Typically, the fabrication of aerogel is a multistep process, involving hydrogel formation via sol–gel technique followed by freeze drying or

• critical point drying [6]. During hydrogel formation, GO undergoes reduction. Therefore, after solvent removal, it forms a reduced graphene oxide (rGO) porous structure [7]. Currently, lots of research has been focused on the potential applications of rGO-based aerogels in energy storage systems (i.e., Li

• introduction into aerogel. The first method is based on the addition of iron precursors to GO water dispersion and “in situ” synthesis of iron oxide MNPs during hydrothermal hydrogel formation in autoclave. The precipitated nanoparticles are anchored to GO structure via Fe–C–O bonds or confined between GO

Liquid-crystalline nanoarchitectures for tissue engineering

• Baeckkyoung Sung and
• Min-Ho Kim

Beilstein J. Nanotechnol. 2018, 9, 205–215, doi:10.3762/bjnano.9.22

• electrostatically induced phase transitions from isotropic sol to nematic gel of synthetic nanofibers or filamentous bacteriophages can be adopted as a mild and efficient process for cell encapsulation in a highly anisotropic hydrogel scaffold [91][103]. These in situ cell inclusion techniques allow for the

• hydrogel composed of the aligned nanofibrils, enhanced cellular outgrowth was induced via augmented expression of integrin α1, which resulted in arteriogenesis and blood perfusion recovery in the mouse ischemia model. In another study, hydrogel films made of concentrated collagen type I showed regular

Vapor-based polymers: from films to nanostructures

• Meike Koenig and
• Joerg Lahann

Beilstein J. Nanotechnol. 2017, 8, 2219–2220, doi:10.3762/bjnano.8.221

• desired nanostructures. This combination of a conductive polymer with a hydrogel in a single nanostructure shows potential for the use in humidity sensors. Without the need for additives or solvents, a high purity of the resulting film is ensured, which is of paramount importance in the area of electronic