Force sensors for measuring microenvironmental forces during mesenchymal condensation

Rosenfeld

et al. 2023

Small

Colloidal colorimetric microsensors enable the in‐situ detection of mechanical strains within materials. Enhancing the sensitivity of these sensors to small scale deformation while enabling reversibility of the sensing capability would expand their utility in applications including biosensing and chemical sensing. In this study, we introduce the synthesis of colloidal colorimetric nano‐sensors using a simple and readily scalable fabrication method. Colloidal nano sensors are prepared by emulsion‐templated assembly of polymer‐grafted gold nanoparticles (AuNP). To direct the adsorption of AuNP to the oil‐water interface of emulsion droplets, AuNP (≈11nm) are functionalized with thiol‐terminated polystyrene (PS, Mn = 11k). These PS‐grafted gold nanoparticles are suspended in toluene and subsequently emulsified to form droplets with a diameter of ≈30µm. By evaporating the solvent of the oil‐inwater emulsion, we form nanocapsules (AuNC) (diameter < 1µm) decorated by PS‐grafted AuNP. To test mechanical sensing, the AuNC are embedded in an elastomer matrix. The addition of a plasticizer reduces the glass transition temperature of the PS brushes, and in turn imparts reversible deformability to the AuNC. The plasmonic peak of the AuNC shifts towards lower wavelengths upon application of uniaxial tensile tension, indicating increased inter‐nanoparticle distance, and reverts back as the tension is released.

Section: Discussionmentioning

confidence: 99%

Polymer‐Grafted, Gold Nanoparticle‐Based Nano‐Capsules as Reversible Colorimetric Tensile Strain Sensors

Rosenfeld

et al. 2023

Small

“…This force is exerted on the incorporated HMPs through cellular interactions with HMPs such as integrin-based bindings. The magnitude of this force has been measured by analyzing the deformation of the incorporated microdroplets from the initial spherical shape (Campàs et al 2014;Móczó and Pukánszky 2016;Abbasi et al 2018;Gutierrez et al 2021). Taken together, through the incorporation of HMPs inside the aggregates, three major advantages will be obtained: (i) The BAs can be homogenously delivered throughout the aggregates in an inside-out, localized, sustained, and controllable manner; (ii) the mechanical properties of the cell aggregate microenvironment can be tuned similar to the native tissue to more accurately mimic the in vivo condition (mechanical regulation); (iii) the incorporated cell-sized HMPs can operate as the spacers between the cells to enhance the delivery of soluble factors like oxygen and nutrients to the central parts of the aggregates (mass transfer regulator) (Hayashi and Tabata 2011) (Fig.…”

Section: Cell-free Ba-laden Hmpsmentioning

confidence: 99%

Droplet microfluidic devices for organized stem cell differentiation into germ cells: capabilities and challenges

et al. 2021

Demystifying the mechanisms that underlie germline development and gamete production is critical for expanding advanced therapies for infertile couples who cannot benefit from current infertility treatments. However, the low number of germ cells, particularly in the early stages of development, represents a serious challenge in obtaining sufficient materials required for research purposes. In this regard, pluripotent stem cells (PSCs) have provided an opportunity for producing an unlimited source of germ cells in vitro. Achieving this ambition is highly dependent on accurate stem cell niche reconstitution which is achievable through applying advanced cell engineering approaches. Recently, hydrogel microparticles (HMPs), as either microcarriers or microcapsules, have shown promising potential in providing an excellent 3-dimensional (3D) biomimetic microenvironment alongside the systematic bioactive agent delivery. In this review, recent studies of utilizing various HMPbased cell engineering strategies for appropriate niche reconstitution and efficient in vitro differentiation are highlighted with a special focus on the capabilities of droplet-based microfluidic (DBM) technology. We believe that a deep understanding of the current limitations and potentials of the DBM systems in integration with stem cell biology provides a bright future for germ cell research.

Biotech & Bioengineering

“…The method utilizing hydrogel microsphere stress sensor (MSS) is a new type of stress characterization technology, which has the significant characteristics in three‐dimensional (3D) CTF measurement (Ding et al, 2022). It has been applied to the study of related biological issues such as the characterization of the spatial and temporal distribution pattern of stress field within tissues (Berg et al, 2021; Hofemeier et al, 2021; Lee et al, 2019), and the characterization of stress differences around cells to reveal the stress distribution within cells and tissues (Gutierrez et al, 2021; Vorselen et al, 2020, 2021). However, the characterization precision of 3D CTF of single cell by this method is still weak since the limitation of experimental conditions (sensor property modification, operation process simplification, and computational method optimization).…”

Section: Introductionmentioning

confidence: 99%

Quantitative characterization of tumor cell traction force on extracellular matrix by hydrogel microsphere stress sensor

Ma,

Wang,

et al. 2024

Cell traction force (CTF) is a kind of active force that is a cell senses external environment and actively applies to the contact matrix which is currently a representative stress in cell–extracellular matrix (ECM) interaction. Studying the distribution and variation of CTF during cell–ECM interaction help to explain the impact of physical factors on cell behaviors from the perspective of mechanobiology. However, most of the strategies of characterizing CTF are still limited by the measurement needs in three‐dimensional (3D), quantitative characteristics and in vivo condition. Microsphere stress sensor (MSS) as a new type of technology is capable of realizing the quantitative characterization of CTF in 3D and in vivo. Herein, we employed microfluidic platform to design and fabricate MSS which possesses adjustable fluorescent performances, physical properties, and size ranges for better applicable to different cells (3T3, A549). Focusing on the common tumor cells behaviors (adhesion, spreading, and migration) in the process of metastasis, we chose SH‐SY5Y as the representative research object in this work. We calculated CTF with the profile and distribution to demonstrate that the normal and shear stress can determined different cell behaviors. Additionally, CTF can also regulate cell adhesion, spreading, and migration in different cell states. Based on this method, the quantitative characterization of CFT of health and disease cells can be achieved, which further help to study and explore the potential mechanism of cell–ECM interaction.