Encapsulating Networks of Droplet Interface Bilayers in a Thermoreversible Organogel

Challita, Elio J.; Najem, Joseph S.; Monroe, Rachel; Leo, Donald J.; Freeman, Eric C.

doi:10.1038/s41598-018-24720-5

Cited by 21 publications

(44 citation statements)

References 71 publications

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“…In addition, our approach will allow the fabrication of responsive hydrogels across multiple length scales, as droplet volumes can range from fL to μL 18 . Droplet production can even be automated with microfluidics 32 and 3D droplet printers 25 , 33 . The method might be combined with other fabrication methods to create defined droplet features within larger hydrogel structures.…”

Section: Discussionmentioning

confidence: 99%

Multi-responsive hydrogel structures from patterned droplet networks

et al. 2020

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Responsive hydrogels that undergo controlled shape changes in response to a range of stimuli are of interest for microscale soft robotic and biomedical devices. However, these applications require fabrication methods capable of preparing complex, heterogeneous materials. Here we report a new approach for making patterned, multi-material, and multi-responsive hydrogels, on a μm to mm scale. Nanolitre aqueous pre-gel droplets were connected through lipid bilayers in predetermined architectures and photopolymerized to yield continuous hydrogel structures. By using this droplet network technology to pattern domains containing temperature-responsive or non-responsive hydrogels, structures that undergo reversible curling were produced. Through patterning of gold nanoparticle-containing domains into the hydrogels, light-activated shape change was achieved, while domains bearing magnetic particles allowed movement of the structures in a magnetic field. To highlight our technique, we generated a multi-responsive hydrogel that, at one temperature, could be moved through a constriction under a magnetic field; and at a second temperature, could grip and transport a cargo.

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Section: Discussionmentioning

confidence: 99%

Multi-responsive hydrogel structures from patterned droplet networks

et al. 2020

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“…[ 232 ] With the increasing precision of bioengineering, complex artificial cell colonies or prototissues can be constructed to facilitate artificial‐natural cell interactions, constructed through step‐by‐step emulsifications, or via droplet‐by‐droplet assembly with manual deposition, or 3D‐printing methods. [ 233 ] These prototissue models can be programmed to have precise and functional geometries, [ 234 ] and be responsive to external stimuli, [ 235 , 236 , 237 , 238 ] to trigger sequential biochemical reactions. Recently, pioneer studies demonstrate that prototissue models can be utilised to explore the metabolic pathway of natural cells and the development processes of organs.…”

Section: Artificial Cells As Programmable Drug Delivery Platformsmentioning

confidence: 99%

Droplet Microfluidics for Tumor Drug‐Related Studies and Programmable Artificial Cells

Dimitriou

Tornillo

et al. 2021

Global Challenges

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(1 of 17)www.global-challenges.com robotics, have promoted the use of in vitro tumor models in high-throughput drug screenings. [2,3] High-throughput screens for anticancer drugs have been, for a long time, limited to 2D culture of tumor cells, grown as a monolayer on the bottom of a well of a microtiter plate. Compared to 2D cell cultures, 3D culture systems can more faithfully model cell-cell interactions, matrix deposition and tumor microenvironments, including more physiological flow conditions, oxygen and nutrient gradients. [4] Therefore, 3D cultures have recently begun to be incorporated into high-throughput drug screenings, with the aim of better predicting drug efficacy and improving the prioritization of candidate drugs for further in vivo testing in animals.Because of the relatively simple, reproducible, amenable to automation and scalable culture methods, single-cell type and mixed-cell tumor spheroids, known as multicellular tumor spheroids (MCTSs), are used as 3D models. [5] There exists a broad range of natural hydrogels that are compatible with microfluidics, and which provide cancer cells with mechanical cues and adhesion sites to proliferate and grow into MCTSs. [6] With the aid of microfluidics and development of more complex 3D tumor models, [7,8] and the large-scale production of tumor spheroids in hydrogels, the number of compounds that could progress to in vivo testing could be restricted, thus reducing the number of animals needed for preclinical studies.Tumor-targeted drug delivery using microparticles and liposomes is beneficial compared to conventional drug administration. This is because encapsulated drug dosages can be controlled, healthy tissues can remain unharmed during treatment and drug resistance of cancer cells may be reduced/ prevented. [9,10] Microparticles and liposomes can be tailored to specifically target tumor sites using molecular conjugates, while avoiding toxic effects. [9] This review discusses the application of droplet-based microfluidic technologies for the development of accurate in vitro tumor models and improved cancer treatment strategies. The first part of the review centers around the generation of MCTSs in natural hydrogels for a better recapitulation of the in vivo tumor microenvironment. The second section is focused on microparticle and liposomal production for tumor-targeted drug delivery. Emphases is given to microfluidic methodologies for the production of these systems, and the potential of compartmentalized artificial cells as anticancer drug screening platforms.

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“…As Villar concluded, (these networks) “might be interfaced with tissues, used as tissue engineering substrates, or developed as mimics of living tissue” [ 48 ]. These systems have also been extended by others into droplet microfluidics for the construction of compartmentalised model membranes [ 50 ], and organogels [ 51 ]. Here then, this simple BLM, when flipped to be a bilayer between water droplets in oil ( Figure 2 B), has now spawned over 1000 entries listed on Google Scholar.…”

Section: Introductionmentioning

confidence: 99%

Micro-Surface and -Interfacial Tensions Measured Using the Micropipette Technique: Applications in Ultrasound-Microbubbles, Oil-Recovery, Lung-Surfactants, Nanoprecipitation, and Microfluidics

Kinoshita

Utoft

2019

Micromachines

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This review presents a series of measurements of the surface and interfacial tensions we have been able to make using the micropipette technique. These include: equilibrium tensions at the air-water surface and oil-water interface, as well as equilibrium and dynamic adsorption of water-soluble surfactants and water-insoluble and lipids. At its essence, the micropipette technique is one of capillary-action, glass-wetting, and applied pressure. A micropipette, as a parallel or tapered shaft, is mounted horizontally in a microchamber and viewed in an inverted microscope. When filled with air or oil, and inserted into an aqueous-filled chamber, the position of the surface or interface meniscus is controlled by applied micropipette pressure. The position and hence radius of curvature of the meniscus can be moved in a controlled fashion from dimensions associated with the capillary tip (~5–10 μm), to back down the micropipette that can taper out to 450 μm. All measurements are therefore actually made at the microscale. Following the Young–Laplace equation and geometry of the capillary, the surface or interfacial tension value is simply obtained from the radius of the meniscus in the tapered pipette and the applied pressure to keep it there. Motivated by Franklin’s early experiments that demonstrated molecularity and monolayer formation, we also give a brief potted-historical perspective that includes fundamental surfactancy driven by margarine, the first use of a micropipette to circuitously measure bilayer membrane tensions and free energies of formation, and its basis for revolutionising the study and applications of membrane ion-channels in Droplet Interface Bilayers. Finally, we give five examples of where our measurements have had an impact on applications in micro-surfaces and microfluidics, including gas microbubbles for ultrasound contrast; interfacial tensions for micro-oil droplets in oil recovery; surface tensions and tensions-in-the surface for natural and synthetic lung surfactants; interfacial tension in nanoprecipitation; and micro-surface tensions in microfluidics.

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Encapsulating Networks of Droplet Interface Bilayers in a Thermoreversible Organogel

Cited by 21 publications

References 71 publications

Multi-responsive hydrogel structures from patterned droplet networks

Multi-responsive hydrogel structures from patterned droplet networks

Droplet Microfluidics for Tumor Drug‐Related Studies and Programmable Artificial Cells

Micro-Surface and -Interfacial Tensions Measured Using the Micropipette Technique: Applications in Ultrasound-Microbubbles, Oil-Recovery, Lung-Surfactants, Nanoprecipitation, and Microfluidics

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