352 results on '"Eugenia Kumacheva"'
Search Results
2. Biomimetic hydrogel supports initiation and growth of patient-derived breast tumor organoids
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Elisabeth Prince, Jennifer Cruickshank, Wail Ba-Alawi, Kelsey Hodgson, Jillian Haight, Chantal Tobin, Andrew Wakeman, Alona Avoulov, Valentina Topolskaia, Mitchell J. Elliott, Alison P. McGuigan, Hal K. Berman, Benjamin Haibe-Kains, David W. Cescon, and Eugenia Kumacheva
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Science - Abstract
Patient-derived tumour organoids are important preclinical models but suffer from variability from the use of basement-membrane extract and cell contamination. Here, the authors report on the development of mimetic nanofibrilar hydrogel which supports tumour organoid growth with reduced batch variability and cell contamination.
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- 2022
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3. Microdroplet-based one-step RT-PCR for ultrahigh throughput single-cell multiplex gene expression analysis and rare cell detection
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Jennifer Ma, Gary Tran, Alwin M. D. Wan, Edmond W. K. Young, Eugenia Kumacheva, Norman N. Iscove, and Peter W. Zandstra
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Medicine ,Science - Abstract
Abstract Gene expression analysis of individual cells enables characterization of heterogeneous and rare cell populations, yet widespread implementation of existing single-cell gene analysis techniques has been hindered due to limitations in scale, ease, and cost. Here, we present a novel microdroplet-based, one-step reverse-transcriptase polymerase chain reaction (RT-PCR) platform and demonstrate the detection of three targets simultaneously in over 100,000 single cells in a single experiment with a rapid read-out. Our customized reagent cocktail incorporates the bacteriophage T7 gene 2.5 protein to overcome cell lysate-mediated inhibition and allows for one-step RT-PCR of single cells encapsulated in nanoliter droplets. Fluorescent signals indicative of gene expressions are analyzed using a probabilistic deconvolution method to account for ambient RNA and cell doublets and produce single-cell gene signature profiles, as well as predict cell frequencies within heterogeneous samples. We also developed a simulation model to guide experimental design and optimize the accuracy and precision of the assay. Using mixtures of in vitro transcripts and murine cell lines, we demonstrated the detection of single RNA molecules and rare cell populations at a frequency of 0.1%. This low cost, sensitive, and adaptable technique will provide an accessible platform for high throughput single-cell analysis and enable a wide range of research and clinical applications.
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- 2021
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4. Computational Modelling and Big Data Analysis of Flow and Drug Transport in Microfluidic Systems: A Spheroid-on-a-Chip Study
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Sina Kheiri, Eugenia Kumacheva, and Edmond W.K. Young
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organ-on-a-chip ,cancer spheroids ,drug delivery ,full-factorial experiments ,microfluidic design space exploration ,hierarchical clustering ,Biotechnology ,TP248.13-248.65 - Abstract
Microfluidic tumour spheroid-on-a-chip platforms enable control of spheroid size and their microenvironment and offer the capability of high-throughput drug screening, but drug supply to spheroids is a complex process that depends on a combination of mechanical, biochemical, and biophysical factors. To account for these coupled effects, many microfluidic device designs and operating conditions must be considered and optimized in a time- and labour-intensive trial-and-error process. Computational modelling facilitates a systematic exploration of a large design parameter space via in silico simulations, but the majority of in silico models apply only a small set of conditions or parametric levels. Novel approaches to computational modelling are needed to explore large parameter spaces and accelerate the optimization of spheroid-on-a-chip and other organ-on-a-chip designs. Here, we report an efficient computational approach for simulating fluid flow and transport of drugs in a high-throughput arrayed cancer spheroid-on-a-chip platform. Our strategy combines four key factors: i) governing physical equations; ii) parametric sweeping; iii) parallel computing; and iv) extensive dataset analysis, thereby enabling a complete “full-factorial” exploration of the design parameter space in combinatorial fashion. The simulations were conducted in a time-efficient manner without requiring massive computational time. As a case study, we simulated >15,000 microfluidic device designs and flow conditions for a representative multicellular spheroids-on-a-chip arrayed device, thus acquiring a single dataset consisting of ∼10 billion datapoints in ∼95 GBs. To validate our computational model, we performed physical experiments in a representative spheroid-on-a-chip device that showed excellent agreement between experimental and simulated data. This study offers a computational strategy to accelerate the optimization of microfluidic device designs and provide insight on the flow and drug transport in spheroid-on-a-chip and other biomicrofluidic platforms.
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- 2021
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5. Printing Structurally Anisotropic Biocompatible Fibrillar Hydrogel for Guided Cell Alignment
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Zhengkun Chen, Nancy Khuu, Fei Xu, Sina Kheiri, Ilya Yakavets, Faeze Rakhshani, Sofia Morozova, and Eugenia Kumacheva
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anisotropy ,cellulose nanofiber ,3D printing ,hydrogels ,alignment ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
Many fibrous biological tissues exhibit structural anisotropy due to the alignment of fibers in the extracellular matrix. To study the impact of such anisotropy on cell proliferation, orientation, and mobility, it is important to recapitulate and achieve control over the structure of man-made hydrogel scaffolds for cell culture. Here, we report a chemically crosslinked fibrous hydrogel due to the reaction between aldehyde-modified cellulose nanofibers and gelatin. We explored two ways to induce structural anisotropy in this gel by extruding the hydrogel precursor through two different printheads. The cellulose nanofibers in the hydrogel ink underwent shear-induced alignment during extrusion and retained it in the chemically crosslinked hydrogel. The degree of anisotropy was controlled by the ink composition and extrusion flow rate. The structural anisotropy of the hydrogel extruded through a nozzle affected the orientation of human dermal fibroblasts that were either seeded on the hydrogel surface or encapsulated in the extruded hydrogel. The reported straightforward approach to constructing fibrillar hydrogel scaffolds with structural anisotropy can be used in studies of the biological impact of tissue anisotropy.
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- 2022
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6. Polyelectrolyte vs Polyampholyte Behavior of Composite Chitosan/Gelatin Films
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Daniel Pinto Ramos, Sharon Sarjinsky, Moien Alizadehgiashi, Juri Möbus, and Eugenia Kumacheva
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Chemistry ,QD1-999 - Published
- 2019
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7. From Structure to Properties of Composite Films Derived from Cellulose Nanocrystals
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Brandon Vollick, Pei-Yu Kuo, Moien Alizadehgiashi, Ning Yan, and Eugenia Kumacheva
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Chemistry ,QD1-999 - Published
- 2017
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8. Colloidal cholesteric liquid crystal in spherical confinement
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Yunfeng Li, Jeffrey Jun-Yan Suen, Elisabeth Prince, Egor M. Larin, Anna Klinkova, Héloïse Thérien-Aubin, Shoujun Zhu, Bai Yang, Amr S. Helmy, Oleg D. Lavrentovich, and Eugenia Kumacheva
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Science - Abstract
Confinement-induced organization of nanoparticles is utilized to generate new structures with novel optical or magnetic properties. Here, Li et al.show that colloidal liquid crystals formed by rod-like nanoparticles self-assemble into various geometries depending on the degree of spherical confinement in droplets.
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- 2016
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9. One-Step Fabrication of Microchannels with Integrated Three Dimensional Features by Hot Intrusion Embossing
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Mike Debono, Dan Voicu, Mohammad Pousti, Muhammad Safdar, Robert Young, Eugenia Kumacheva, and Jesse Greener
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microfluidics ,microfabrication ,thermoplastic ,hot embossing ,intrusion embossing ,Chemical technology ,TP1-1185 - Abstract
We build on the concept of hot intrusion embossing to develop a one-step fabrication method for thermoplastic microfluidic channels containing integrated three-dimensional features. This was accomplished with simple, rapid-to-fabricate imprint templates containing microcavities that locally control the intrusion of heated thermoplastic based on their cross-sectional geometries. The use of circular, rectangular and triangular cavity geometries was demonstrated for the purposes of forming posts, multi-focal length microlense arrays, walls, steps, tapered features and three-dimensional serpentine microchannels. Process variables, such as temperature and pressure, controlled feature dimensions without affecting the overall microchannel geometry. The approach was demonstrated for polycarbonate, cycloolefin copolymer and polystyrene, but in principle is applicable to any thermoplastic. The approach is a step forward towards rapid fabrication of complex, robust, microfluidic platforms with integrated multi-functional elements.
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- 2016
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10. Manipulation of signaling thresholds in 'engineered stem cell niches' identifies design criteria for pluripotent stem cell screens.
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Raheem Peerani, Kento Onishi, Alborz Mahdavi, Eugenia Kumacheva, and Peter W Zandstra
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Medicine ,Science - Abstract
In vivo, stem cell fate is regulated by local microenvironmental parameters. Governing parameters in this stem cell niche include soluble factors, extra-cellular matrix, and cell-cell interactions. The complexity of this in vivo niche limits analyses into how individual niche parameters regulate stem cell fate. Herein we use mouse embryonic stem cells (mESC) and micro-contact printing (microCP) to investigate how niche size controls endogenous signaling thresholds. microCP is used to restrict colony diameter, separation, and degree of clustering. We show, for the first time, spatial control over the activation of the Janus kinase/signal transducer and activator of transcription pathway (Jak-Stat). The functional consequences of this niche-size-dependent signaling control are confirmed by demonstrating that direct and indirect transcriptional targets of Stat3, including members of the Jak-Stat pathway and pluripotency-associated genes, are regulated by colony size. Modeling results and empirical observations demonstrate that colonies less than 100 microm in diameter are too small to maximize endogenous Stat3 activation and that colonies separated by more than 400 microm can be considered independent from each other. These results define parameter boundaries for the use of ESCs in screening studies, demonstrate the importance of context in stem cell responsiveness to exogenous cues, and suggest that niche size is an important parameter in stem cell fate control.
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- 2009
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11. Dual-Function Hydrogel Dressings with a Dynamic Exchange of Iron Ions and an Antibiotic Drug for Treatment of Infected Wounds
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Iuliia Pilipenko, Anna Murzova, Artemii Savin, Al-Abbass Mohamed, Elizaveta Vladimirova, Elena Koshel, Olga Shamova, and Eugenia Kumacheva
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Biomaterials ,Biochemistry (medical) ,Biomedical Engineering ,General Chemistry - Published
- 2023
12. Stimulus-Responsive Transport Properties of Nanocolloidal Hydrogels
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Yuhang Huang, Sofia M. Morozova, Terek Li, Shangyu Li, Hani E. Naguib, and Eugenia Kumacheva
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Biomaterials ,Polymers and Plastics ,Materials Chemistry ,Bioengineering - Abstract
Applications of polymer hydrogels in separation technologies, environmental remediation, and drug delivery require control of hydrogel transport properties that are largely governed by the pore dimensions. Stimulus-responsive change in pore size offers the capability to change gel's transport properties "on demand". Here, we report a nanocolloidal hydrogel that exhibits temperature-controlled increase in pore size and, as a result, enhanced transport of encapsulated species from the gel. The hydrogel was formed by the covalent cross-linking of aldehyde-modified cellulose nanocrystals and chitosan carrying end-grafted poly(
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- 2022
13. A 3D printing approach to intelligent food packaging
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Chantal T. Tracey, Aleksandra L. Predeina, Elena F. Krivoshapkina, and Eugenia Kumacheva
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Food Science ,Biotechnology - Published
- 2022
14. Stimulus-Responsive Nanoconjugates Derived from Phytoglycogen Nanoparticles
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Yingshan Ma, Vahid Adibnia, Monica Mitrache, Ilias Halimi, Gilbert C. Walker, and Eugenia Kumacheva
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Biomaterials ,Methotrexate ,Polymers and Plastics ,Materials Chemistry ,Nanoparticles ,Serum Albumin, Bovine ,Bioengineering ,Nanoconjugates - Abstract
Plant-derived phytoglycogen nanoparticles (PhG NPs) have the advantages of size uniformity, dispersibility in water, excellent lubrication properties, and lack of cytotoxicity; however, their chemical functionalization may lead to loss of NP structural integrity. Here, we report a straightforward approach to the generation of PhG NP conjugates with biologically active molecules. Hydrogen bonding of bovine serum albumin with electroneutral PhG NPs endows them with additional ligand binding affinity and enables the electrostatically governed attachment of methotrexate (MTX), a therapeutic agent commonly used in the treatment of cancer and arthritis diseases, to the protein-capped NPs. We showed stimuli-responsive release of MTX from the PhG-based nanoconjugates under physiological cues such as temperature and ionic strength. The results of this study stimulate future exploration of biomedical applications of nanoconjugates of PhG NPs.
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- 2022
15. The rise of self-driving labs in chemical and materials sciences
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Milad Abolhasani and Eugenia Kumacheva
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- 2023
16. Structurally anisotropic hydrogels for tissue engineering
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Nancy Khuu, Sina Kheiri, and Eugenia Kumacheva
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Materials science ,Characterization methods ,Tissue engineering ,Fabrication methods ,Self-healing hydrogels ,technology, industry, and agriculture ,Nanotechnology ,Critical assessment ,macromolecular substances ,General Chemistry ,Anisotropy ,Biocompatible material ,complex mixtures - Abstract
Many tissues in vivo exhibit structural anisotropy, which endows them with orientation-specific properties and functions. Structurally anisotropic hydrogels have emerged as promising scaffolds for tissue engineering applications, owing to their ability to recapitulate the structure and physical properties of anisotropic tissues in vivo and provide cells with the appropriate cues. This review highlights key progress in the development of biocompatible structurally anisotropic hydrogels for tissue engineering. We provide an overview of tissues with structural anisotropy and different fabrication methods of anisotropic hydrogels, summarize different characterization methods of hydrogel structural anisotropy, and provide insights on the physical properties of anisotropic hydrogels and their impact on cell behavior. We conclude with a critical assessment of future directions of structurally anisotropic hydrogels for tissue engineering applications.
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- 2021
17. Resilient Women and the Resiliency of Science
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Sabrina Sicolo, Qing Shen, Elham Rezasoltani, Stacey F. Bent, Sara E. Skrabalak, Eugenia Kumacheva, Delia J. Milliron, Lihi Adler-Abramovich, Jennifer Neu, Niveen M. Khashab, and Fedwa El-Mellouhi
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Materials science ,General Chemical Engineering ,Materials Chemistry ,General Chemistry ,Developmental psychology - Published
- 2021
18. Nanoparticle synthesis assisted by machine learning
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Alán Aspuru-Guzik, Eugenia Kumacheva, Tianyi Wu, Matteo Aldeghi, Huachen Tao, and Tony C. Wu
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Medical diagnostic ,business.industry ,Nanoparticle ,Polymeric nanoparticles ,Machine learning ,computer.software_genre ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,Materials Chemistry ,Pharmaceutics ,Artificial intelligence ,business ,computer ,Energy (miscellaneous) - Abstract
Many properties of nanoparticles are governed by their shape, size, polydispersity and surface chemistry. To apply nanoparticles in chemical sensing, medical diagnostics, catalysis, thermoelectrics, photovoltaics or pharmaceutics, they have to be synthesized with precisely controlled characteristics. This is a time-consuming, laborious and resource-intensive task, because nanoparticle syntheses often include multiple reagents and are conducted under interdependent experimental conditions. Machine learning (ML) offers a promising tool for the accelerated development of efficient protocols for nanoparticle synthesis and, potentially, for the synthesis of new types of nanoparticles. In this Review, we discuss ML algorithms that can be used for nanoparticle synthesis and highlight key approaches for the collection of large datasets. We examine ML-guided synthesis of semiconductor, metal, carbon-based and polymeric nanoparticles, and conclude with a discussion of current limitations, advantages and perspectives in the development of ML-assisted nanoparticle synthesis. Machine learning can be applied for the controlled synthesis of nanoparticles with precise properties. This Review discusses different machine learning approaches for the synthesis of semiconductor, metal, carbon-based and polymeric nanoparticles, and highlights key approaches for the collection of large datasets.
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- 2021
19. Multifunctional 3D-Printed Wound Dressings
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Nancy Khuu, Daniel Pinto Ramos, Shana O. Kelley, Eugenia Kumacheva, Moien Alizadehgiashi, Sharif Uddin Ahmed, Nitesh Mittal, Mahshid Chekini, and Carine R. Nemr
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Vascular Endothelial Growth Factor A ,Wound site ,3d printed ,Silver ,Personalized treatment ,Metal Nanoparticles ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Silver nanoparticle ,Mice ,medicine ,Animals ,General Materials Science ,integumentary system ,Chemistry ,General Engineering ,Granulation tissue ,Hydrogels ,021001 nanoscience & nanotechnology ,Bandages ,Controlled release ,Physiological responses ,Anti-Bacterial Agents ,0104 chemical sciences ,medicine.anatomical_structure ,Printing, Three-Dimensional ,Drug delivery ,0210 nano-technology ,Biomedical engineering - Abstract
Personalized wound dressings provide enhanced healing for different wound types; however multicomponent wound dressings with discretely controllable delivery of different biologically active agents are yet to be developed. Here we report 3D-printed multicomponent biocomposite hydrogel wound dressings that have been selectively loaded with small molecules, metal nanoparticles, and proteins for independently controlled release at the wound site. Hydrogel wound dressings carrying antibacterial silver nanoparticles and vascular endothelial growth factor with predetermined release profiles were utilized to study the physiological response of the wound in a mouse model. Compared to controls, the application of dressings resulted in improvement in granulation tissue formation and differential levels of vascular density, dependent on the release profile of the growth factor. Our study demonstrates the versatility of the 3D-printed hydrogel dressings that can yield varied physiological responsesiin vivo/iand can further be adapted for personalized treatment of various wound types.
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- 2021
20. Oxidative Elimination and Reductive Addition of Thiol‐Terminated Polymer Ligands to Metal Nanoparticles
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Jing Kang, Yu‐Xi Wang, Fei Peng, Ning‐Ning Zhang, Yao Xue, Yang Yang, Eugenia Kumacheva, and Kun Liu
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Oxidative Stress ,Polymers ,Metal Nanoparticles ,General Medicine ,Gold ,Sulfhydryl Compounds ,General Chemistry ,Ligands ,Oxidation-Reduction ,Catalysis - Abstract
Metal nanoparticles (NPs) stabilized with thiol- (HS-) terminated polymers have applications in medicine, optoelectronics, and catalysis. It is assumed that upon exposure to oxidants or even air, these NPs lose colloidal stability, due to the oxidation of the HS-end-group and elimination of polymer ligands from the NP surface, however, this mechanism does not explain the unsuccessful recovery of the NP stability by adding fresh HS-terminated polymers. Here we propose the oxidation of the surface metal atoms as a mechanism for the oxidative elimination of polymer from the NP surface. Based on this mechanism, we reversed NP aggregation by reducing the oxidized metal surface and re-attaching HS-terminated polymer ligands. This mechanism is general for various metal NPs and different HS-terminated polymers. We show that oxidative elimination and reductive addition reactions can improve the colloidal stability of polymer-capped metal NPs and control their redox stimuli-responsive self-assembly.
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- 2022
21. Polymer-Tethered Nanoparticles: From Surface Engineering to Directional Self-Assembly
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Ning-Ning Zhang, Xiaoxue Shen, Kun Liu, Zhihong Nie, and Eugenia Kumacheva
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Polymers ,Nanoparticles ,General Medicine ,General Chemistry ,Ligands ,Micelles ,Nanostructures - Abstract
Current interest in nanoparticle ensembles is motivated by their collective synergetic properties that are distinct from or better than those of individual nanoparticles and their bulk counterparts. These new advanced optical, electronic, magnetic, and catalytic properties can find applications in advanced nanomaterials and functional devices, if control is achieved over nanoparticle organization. Self-assembly offers a cost-efficient approach to produce ensembles of nanoparticles with well-defined and predictable structures. Nanoparticles functionalized with polymer molecules are promising building blocks for self-assembled nanostructures, due to the comparable dimensions of macromolecules and nanoparticles, the ability to synthesize polymers with various compositions, degrees of polymerization, and structures, and the ability of polymers to self-assemble in their own right. Moreover, polymer ligands can endow additional functionalities to nanoparticle assemblies, thus broadening the range of their applications.In this Account, we describe recent progress of our research groups in the development of new strategies for the self-assembly of nanoparticles tethered to macromolecules. At the beginning of our journey, we developed a new approach to patchy nanoparticles and their self-assembly. In a thermodynamically driven strategy, we used poor solvency conditions to induce homopolymer surface segregation in pinned micelles (patches). Patchy nanoparticles underwent self-assembly in a well-defined and controlled manner. Following this work, we overcame the limitation of low yield of the generation of patchy nanoparticles, by using block copolymer ligands. For block copolymer-capped nanoparticles, patch formation and self-assembly were "staged" by using distinct stimuli for each process. We expanded this work to the generation of patchy nanoparticles via dynamic exchange of block copolymer molecules between the nanoparticle surface and micelles in the solution. The scope of our work was further extended to a series of strategies that utilized the change in the configuration of block copolymer ligands during nanoparticle interactions. To this end, we explored the amphiphilicity of block copolymer-tethered nanoparticles and complementary interactions between reactive block copolymer ligands. Both approaches enabled exquisite control over directional and self-limiting self-assembly of complex hierarchical nanostructures. Next, we focused on the self-assembly of chiral nanostructures. To enable this goal, we attached chiral molecules to the surface of nanoparticles and organized these hybrid building blocks in ensembles with excellent chiroptical properties. In summary, our work enables surface engineering of polymer-capped nanoparticles and their controllable and predictable self-assembly. Future research in the field of nanoparticle self-assembly will include the development of effective characterization techniques, the synthesis of new functional polymers, and the development of environmentally responsive self-assembly of polymer-capped nanoparticles for the fabrication of nanomaterials with tailored functionalities.
- Published
- 2022
22. Microfluidic arrays of dermal spheroids: a screening platform for active ingredients of skincare products
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Albert Gevorkian, Valerie Andre, Eugenia Kumacheva, Edmond W. K. Young, Sina Kheiri, Ted Deisenroth, and Zhengkun Chen
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Collagen type ,Active ingredient ,0303 health sciences ,Drug discovery ,Chemistry ,Microfluidics ,Cell Culture Techniques ,Biomedical Engineering ,Spheroid ,Hydrogels ,Bioengineering ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Biochemistry ,In vitro model ,Dermal fibroblast ,03 medical and health sciences ,Spheroids, Cellular ,Animals ,Multicellular spheroid ,0210 nano-technology ,030304 developmental biology ,Biomedical engineering - Abstract
Organotypic micrometre-size 3D aggregates of skin cells (multicellular spheroids) have emerged as a promising in vitro model that can be utilized as an alternative of animal models to test active ingredients (AIs) of skincare products; however, a reliable dermal spheroid-based microfluidic (MF) model with a goal of in vitro AI screening is yet to be developed. Here, we report a MF platform for the growth of massive arrays of dermal fibroblast spheroids (DFSs) in a biomimetic hydrogel under close-to-physiological flow conditions and with the capability of screening AIs for skincare products. The DFSs formed after two days of on-chip culture and, in a case study, were used in a time-efficient manner for screening the effect of vitamin C on the synthesis of collagen type I and fibronectin. The computational simulation showed that the uptake of vitamin C was dominated by the advection flux. The results of screening the benchmark AI, vitamin C, proved that DFSs can serve as a reliable in vitro dermal model. The proposed DFS-based MF platform offers a high screening capacity for AIs of skincare products, as well as drug discovery and development in dermatology.
- Published
- 2021
23. Nanocolloidal Hydrogel with Sensing and Antibacterial Activities Governed by Iron Ion Sequestration
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Marina Dukhinova, Liubov Shkodenko, Elena F. Krivoshapkina, Eugenia Kumacheva, Mahshid Chekini, Sina Kheiri, Elena I. Koshel, Nancy Khuu, and Maria Shestovskaya
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integumentary system ,Chemistry ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Materials Chemistry ,Wound closure ,sense organs ,0210 nano-technology ,Wound healing ,Biomedical engineering - Abstract
Advanced wound dressings improve wound healing by releasing antibacterial agents, accelerating wound closure, and reporting (sensing) changes in the wound’s state. The challenge with the release of...
- Published
- 2020
24. Nanostructured Temperature Indicator for Cold Chain Logistics
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Anastasiya Navrotskaya, Darya Aleksandrova, Mahshid Chekini, Ilya Yakavets, Sina Kheiri, Elena Krivoshapkina, and Eugenia Kumacheva
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Refrigeration ,General Engineering ,Temperature ,Solvents ,General Physics and Astronomy ,Water ,General Materials Science ,Dimethyl Sulfoxide ,Carbon - Abstract
Food, chemicals, agricultural products, drugs, and vaccines should be transported and stored within an appropriate low-temperature range, following cold chain logistics. Violations of the required temperature regime are generally reported by time-temperature indicators; however, current sensors do not cover a sufficiently broad low-temperature range and may lack thermal and photostability. Here, we report a nanostructured solvatochromic temperature indicator formed from cellulose nanocrystals decorated with carbon dots (C-dots). The indicator utilizes a strong nonlinear dependence of photoluminescence of C-dots on the composition of water/dimethyl sulfoxide (DMSO) solvent and a composition-dependent variation of the melting temperature of the water/DMSO mixture. Exceeding the temperature of the frozen mixed solvent above a designated threshold value results in solvent melting, flow, and impregnation of the nanostructured film, thus causing an irreversible change in the intensity and wavelength of photoluminescence emission of the film, which is reported both qualitatively and quantitatively. The indicator covers a temperature range from -68 to +19 °C and is cost-efficient, portable and photo- and thermostable.
- Published
- 2022
25. Bipolar-shell resurfacing for blue LEDs based on strongly confined perovskite quantum dots
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Min-Jae Choi, Oleksandr Voznyy, Mahshid Chekini, Ya-Kun Wang, Eugenia Kumacheva, Yuan Liu, Dongxin Ma, Hinako Ebe, Se-Woong Baek, Yitong Dong, James Z. Fan, Zheng-Hong Lu, Rafael Quintero-Bermudez, Fanglong Yuan, Yi Hou, Liang-Sheng Liao, Sjoerd Hoogland, Edward H. Sargent, Laxmi Kishore Sagar, Bin Sun, Petar Todorović, Bin Chen, Filip Dinic, Makhsud I. Saidaminov, Andrew Johnston, Seungjin Lee, Peicheng Li, Hao Ting Kung, Erdmann Spiecker, and Mingjian Wu
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Electron mobility ,Photoluminescence ,Materials science ,business.industry ,Biomedical Engineering ,Quantum yield ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Ion ,Semiconductor ,Quantum dot ,Optoelectronics ,General Materials Science ,Quantum efficiency ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Perovskite (structure) - Abstract
Colloidal quantum dot (QD) solids are emerging semiconductors that have been actively explored in fundamental studies of charge transport1 and for applications in optoelectronics2. Forming high-quality QD solids—necessary for device fabrication—requires substitution of the long organic ligands used for synthesis with short ligands that provide increased QD coupling and improved charge transport3. However, in perovskite QDs, the polar solvents used to carry out the ligand exchange decompose the highly ionic perovskites4. Here we report perovskite QD resurfacing to achieve a bipolar shell consisting of an inner anion shell, and an outer shell comprised of cations and polar solvent molecules. The outer shell is electrostatically adsorbed to the negatively charged inner shell. This approach produces strongly confined perovskite QD solids that feature improved carrier mobility (≥0.01 cm2 V−1 s−1) and reduced trap density relative to previously reported low-dimensional perovskites. Blue-emitting QD films exhibit photoluminescence quantum yields exceeding 90%. By exploiting the improved mobility, we have been able to fabricate CsPbBr3 QD-based efficient blue and green light-emitting diodes. Blue devices with reduced trap density have an external quantum efficiency of 12.3%; the green devices achieve an external quantum efficiency of 22%. A solution-based ligand-exchange strategy enables the realization of close-packed quantum dot solid films with near-unity photoluminescence quantum yield and high charge carrier mobility.
- Published
- 2020
26. Solvent-Mediated Isolation of Polymer-Grafted Nanoparticles
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Megan G. Roberts, Carleigh Pace-Tonna, Mahshid Chekini, Ekaterina B. Zhulina, Pournima Narayanan, Elisabeth Prince, and Eugenia Kumacheva
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chemistry.chemical_classification ,Polymers and Plastics ,Chemistry ,Organic Chemistry ,Nanoparticle ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Solvent ,Chemical engineering ,Materials Chemistry ,0210 nano-technology - Abstract
Nanoparticles (NPs) functionalized with polymers have a broad range of applications; however, a key challenge is to achieve high-yield and time-efficient isolation of the polymer-capped NPs from fr...
- Published
- 2020
27. Colloidal stability of nanoparticles stabilized with mixed ligands in solvents with varying polarity
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Eugenia Kumacheva, Zhihong Nie, Hu Zhu, Pournima Narayanan, Kun Liu, and Elisabeth Prince
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inorganic chemicals ,Polarity (physics) ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,Colloid ,chemistry.chemical_compound ,Bromide ,Materials Chemistry ,chemistry.chemical_classification ,digestive, oral, and skin physiology ,technology, industry, and agriculture ,Metals and Alloys ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Solvent ,chemistry ,Chemical engineering ,Ceramics and Composites ,Gradual increase ,0210 nano-technology ,Layer (electronics) - Abstract
Colloidal stability of nanoparticles (NPs) strongly influences their synthesis, processing, and applications. For gold NPs stabilized with cetyl trimethylammonium bromide (CTAB) and polymer ligands we show that gradual increase in polarity of the water/aprotic solvent mixture leads to stabilization-aggregation-stabilization-aggregation transitions. We propose that these transitions are mediated by structural rearrangements of the CTAB layer on the NP surface.
- Published
- 2020
28. Composite Microgels for Imaging-Monitored Tracking of the Delivery of Vascular Endothelial Growth Factor to Ischemic Muscles
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Eugenia Kumacheva, Seyed Sepehr Mohseni, Azadeh Ghaee, Alireza Rajabnejadkeleshteri, Mehdi Farokhi, Hamideh Basiri, and Ali Abouei Mehrizi
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Vascular Endothelial Growth Factor A ,Biodistribution ,Polymers and Plastics ,Angiogenesis ,Fibroin ,Neovascularization, Physiologic ,Bioengineering ,02 engineering and technology ,Chick Embryo ,Biomaterials ,03 medical and health sciences ,chemistry.chemical_compound ,Tissue engineering ,Materials Chemistry ,Animals ,Tissue Distribution ,Therapeutic angiogenesis ,030304 developmental biology ,0303 health sciences ,Microgels ,Chemistry ,Muscles ,021001 nanoscience & nanotechnology ,In vitro ,3. Good health ,Cell biology ,Vascular endothelial growth factor ,Chorioallantoic membrane ,0210 nano-technology - Abstract
Monitoring the supply of vascular endothelial growth factor (VEGF) to ischemic tissues provides information on its biodistribution and delivery to meet the requirements of therapeutic angiogenesis and tissue engineering applications. We herein report the use of microfluidically generated microgels containing VEGF-conjugated fluorescent carbon dots (CDs) (VEGF-CDs), a gelatin-phenol conjugate, and silk fibroin for imaging-monitored tracking of VEGF delivery to ischemic muscles. An in vitro release study and a bioactivity assay indicated that the VEGF-CDs were released in a sustained manner with high bioactivity. The microgels showed a high angiogenesis potential, along with a strong fluorescent signal, for the chicken chorioallantoic membrane and chick embryo. Imaging and studies of therapeutic modalities of the composite microgels indicated their effective localization in ischemic tissues and sustained VEGF release, which resulted in enhanced therapeutic angiogenesis of ischemic muscles. This work reveals the success of using VEGF-loaded composite polymer microgels for efficient and monitored VEGF delivery by intramuscular administration for ischemic disease treatment.
- Published
- 2021
29. Microfluidic Reactors for Polymer Particles
- Author
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Eugenia Kumacheva, Piotr Garstecki and Eugenia Kumacheva, Piotr Garstecki
- Published
- 2011
30. Cylindrical Confinement of Nanocolloidal Cholesteric Liquid Crystal
- Author
-
Yongliang Wang, Eugenia Kumacheva, Elisabeth Prince, and Ivan I. Smalyukh
- Subjects
Capillary Tubing ,Materials science ,Capillary action ,Cholesteric liquid crystal ,Shell (structure) ,Physics::Optics ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Topological defect ,Physics::Fluid Dynamics ,Condensed Matter::Soft Condensed Matter ,Core (optical fiber) ,Liquid crystal ,Materials Chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
The organization of nanocolloidal liquid crystals in constrained geometries has fundamental and practical importance, since under confinement, liquid crystals contain stable topological defects that can serve as templates for nanoparticle organization. Three-dimensional confinement of cholesteric (Ch) liquid crystals formed by cellulose nanocrystals (CNCs) have been extensively studied; however, their two-dimensional confinement remains under-investigated. Here, we report the results of systematic experimental studies of two-dimensional confinement of Ch-CNC liquid crystal in cylindrical capillaries with varying inner diameters. Confinement resulted in phase separation of the Ch-CNC liquid crystal into a Ch shell formed by concentric CNC pseudolayers with the helicoidal axis perpendicular to the inner surface of the capillary walls, and a micrometer-diameter isotropic core thread running parallel to the long axis of the capillary. The morphology of the confined Ch-CNC liquid crystal varied when progressively increasing the degree confinement. Finally, we show that phase separation of the Ch-CNC liquid crystal into a Ch shell and an isotropic core is preserved in flexible capillary tubing, suggesting the applicability of this system for the fabrication of flexible optical waveguides.
- Published
- 2021
31. Phytoglycogen nanoparticles : nature-derived superlubricants
- Author
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Ilias Halimi, Yingshan Ma, Vahid Adibnia, Gilbert C. Walker, Xavier Banquy, Eugenia Kumacheva, and Université de Montréal. Faculté de pharmacie
- Subjects
Materials science ,General Physics and Astronomy ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Adsorption ,Monolayer ,Bound water ,General Materials Science ,Phytoglycogen ,Hydrogen bond ,Surface force ,General Engineering ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,Green chemistry ,Branched polymers ,Lubrication ,Biolubrication ,Nanoparticles ,0210 nano-technology - Abstract
Phytoglycogen nanoparticles (PhG NPs), a single-molecule highly branched polysaccharide, exhibit excellent water retention, due to the abundance of close-packed hydroxyl groups forming hydrogen bonds with water. Here we report lubrication properties of close-packed adsorbed monolayers of PhG NPs acting as boundary lubricants. Using direct surface force measurements, we show that the hydrated nature of the NP layer results in its striking lubrication performance, with two distinct confinement-controlled friction coefficients. In the weak- to moderate-confinement regime, when the NP layer is compressed down to 8% of its original thickness under a normal pressure of up to 2.4 MPa, the NPs lubricate the surface with a friction coefficient of 10-3. In the strong-confinement regime, with 6.5% of the original layer thickness under a normal pressure of up to 8.1 MPa, the friction coefficient was 10-2. Analysis of the water content and energy dissipation in the confined NP film reveals that the lubrication is governed by synergistic contributions of unbound and bound water molecules, with the former contributing to lubrication properties in the weak- to moderate-confinement regime and the latter being responsible for the lubrication in the strong-confinement regime. These results unravel mechanistic insights that are essential for the design of lubricating systems based on strongly hydrated NPs.
- Published
- 2021
32. Helicoidal Patterning of Gold Nanorods by Phase Separation in Mixed Polymer Brushes
- Author
-
Eugenia Kumacheva, Elizabeth Galati, Joseph G. Manion, Linye Chen, Huachen Tao, Ekaterina B. Zhulina, and Dwight S. Seferos
- Subjects
chemistry.chemical_classification ,Materials science ,Nanoparticle ,02 engineering and technology ,Surfaces and Interfaces ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Nanomaterials ,chemistry.chemical_compound ,Colloid ,chemistry ,Chemical engineering ,Monolayer ,Electrochemistry ,General Materials Science ,Nanorod ,Polystyrene ,0210 nano-technology ,Ethylene glycol ,Spectroscopy - Abstract
The spatial distribution of polymer ligands on the surface of nanoparticles (NPs) is of great importance because it determines their interactions with each other and with the surrounding environment. Phase separation in mixtures of polymer brushes has been studied for spherical NPs; however, the role of local surface curvature of nonspherical NPs in the surface phase separation of end-grafted polymer ligands remains an open question. Here, we examined phase separation in mixed monolayers of incompatible polystyrene and poly(ethylene glycol) brushes end-capping the surface of gold nanorods in a good solvent. By varying the molar ratio between these polymers, we generated a range of surface patterns, including uniform and nonuniform polystyrene shells, randomly distributed polystyrene surface patches, and, most interestingly, a helicoidal pattern of polystyrene patches wrapping around the nanorods. The helicoidally patterned nanorods exhibited long-term colloidal stability in a good solvent. The helicoidal wrapping of the nanorods was achieved for the mixtures of polymers with different molecular weights and preserved when the quality of the solvent for the polymers was reduced. The helicoidal organization of polymer patches on the surface of nanorods can be used for templating the synthesis or self-assembly of helicoidal multicomponent nanomaterials.
- Published
- 2019
33. Staged Surface Patterning and Self‐Assembly of Nanoparticles Functionalized with End‐Grafted Block Copolymer Ligands
- Author
-
Eugenia Kumacheva, Christian Rossner, and Ekaterina B. Zhulina
- Subjects
Chemistry ,Ligand ,technology, industry, and agriculture ,Nanoparticle ,General Chemistry ,General Medicine ,Micelle ,Catalysis ,Colloid ,Chemical engineering ,Copolymer ,Molecule ,Self-assembly ,Self-assembly of nanoparticles - Abstract
Using two orthogonal external stimuli, programmable staged surface patterning and self-assembly of inorganic nanoparticles (NPs) was achieved. For gold NPs capped with end-grafted poly(styrene-block-(4-vinylbenzoic acid)), P(St-block-4VBA), block copolymer ligands, surface-pinned micelles (patches) formed from NP-adjacent PSt blocks under reduced solvency conditions (Stimulus 1); solvated NP-remote P(4VBA) blocks stabilized the NPs against aggregation. Subsequent self-assembly of patchy NPs was triggered by crosslinking the P(4VBA) blocks with copper(II) ions (Stimulus 2). Block copolymer ligand design has a strong effect on NP self-assembly. Small, well-defined clusters assembled from NPs functionalized with ligands with a short P(4VBA) block, while NPs tethered with ligands with a long P(4VBA) block formed large irregularly shaped assemblies. This approach is promising for high-yield fabrication of colloidal molecules and their assemblies with structural and functional complexity.
- Published
- 2019
34. Helicoidal Patterning of Nanorods with Polymer Ligands
- Author
-
Elizabeth Galati, Michael Rubinstein, Moritz Tebbe, Eugenia Kumacheva, Rija Ansari, Huachen Tao, and Ekaterina B. Zhulina
- Subjects
chemistry.chemical_classification ,Morphology (linguistics) ,Materials science ,010405 organic chemistry ,Ligand ,Nanoparticle ,02 engineering and technology ,General Medicine ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,010402 general chemistry ,01 natural sciences ,Micelle ,Article ,Catalysis ,0104 chemical sciences ,chemistry ,Chemical engineering ,Nanorod ,Self-assembly ,0210 nano-technology ,Layer (electronics) - Abstract
Chiral packing of ligands on the surface of nanoparticles (NPs) is of fundamental and practical importance, as it determines how NPs interact with each other and with the molecular world. Herein, for gold nanorods (NRs) capped with end-grafted nonchiral polymer ligands, we show a new mechanism of chiral surface patterning. Under poor solvency conditions, a smooth polymer layer segregates into helicoidally organized surface-pinned micelles (patches). The helicoidal morphology is dictated by the polymer grafting density and the ratio of the polymer ligand length to nanorod radius. Outside this specific parameter space, a range of polymer surface structures was observed, including random, shish-kebab, and hybrid patches, as well as a smooth polymer layer. We characterize polymer surface morphology by theoretical and experimental state diagrams. The helicoidally organized polymer patches on the NR surface can be used as a template for the helicoidal organization of other NPs, masked synthesis on the NR surface, as well as the exploration of new NP self-assembly modes.
- Published
- 2019
35. Design and applications of man-made biomimetic fibrillar hydrogels
- Author
-
Eugenia Kumacheva and Elisabeth Prince
- Subjects
Biomimetic materials ,Chemistry ,Nanotechnology ,macromolecular substances ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,3D cell culture ,Tissue engineering ,Self-healing hydrogels ,Materials Chemistry ,0210 nano-technology ,Energy (miscellaneous) - Abstract
Many extracellular matrices (ECMs) have a filamentous architecture, which influences cell growth and phenotype and imparts tissues with specific properties. Man-made fibrillar hydrogels can function as biomimetic materials to reproduce the filamentous nature and properties of ECMs and to serve as scaffolds for 3D cell culture and tissue engineering. Different types of synthetic nanofibrillar hydrogels have been developed, with diverse mechanisms of assembly and a variety of physical properties and applications. In this Review, we explore the design and properties of biomimetic man-made nanofibrillar hydrogels. We discuss the assembly of peptides, block copolymer worm-like micelles and filamentous nanoparticles into fibrillar hydrogels and investigate the relationship between structure and physical as well as biochemical properties. Potential applications for 3D cell culture and tissue engineering are examined, and the properties and structure of natural and man-made fibrillar hydrogels are compared. Finally, we critically assess current challenges and future directions of the field. Man-made fibrillar hydrogels mimic the structure of filamentous extracellular matrices and can be used as biomaterials for 3D cell culture and tissue engineering. In this Review, the authors discuss the design and properties of fibrillar hydrogels and explore different building blocks, assembly mechanisms, properties and applications.
- Published
- 2019
36. Self-organization of nanoparticles and molecules in periodic Liesegang-type structures
- Author
-
Ivan I. Smalyukh, Eugenia Kumacheva, Gábor Holló, Honghu Zhang, Haridas Mundoor, István Lagzi, Oleg Gang, and Amanda J. Ackroyd
- Subjects
Self-organization ,Work (thermodynamics) ,Multidisciplinary ,Materials science ,Hierarchy (mathematics) ,Precipitation (chemistry) ,Diffusion ,Materials Science ,SciAdv r-articles ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Suspension (chemistry) ,Chemistry ,Chemical physics ,Molecule ,0210 nano-technology ,Research Articles ,Research Article - Abstract
Solvent evaporation from a suspension of cellulose nanocrystals and l-(+)-tartaric acid leads to periodic ring-type patterns., Chemical organization in reaction-diffusion systems offers a strategy for the generation of materials with ordered morphologies and structural hierarchy. Periodic structures are formed by either molecules or nanoparticles. On the premise of new directing factors and materials, an emerging frontier is the design of systems in which the precipitation partners are nanoparticles and molecules. We show that solvent evaporation from a suspension of cellulose nanocrystals (CNCs) and l-(+)-tartaric acid [l-(+)-TA] causes phase separation and precipitation, which, being coupled with a reaction/diffusion, results in rhythmic alternation of CNC-rich and l-(+)-TA–rich rings. The CNC-rich regions have a cholesteric structure, while the l-(+)-TA–rich bands are formed by radially aligned elongated bundles. The moving edge of the pattern propagates with a finite constant velocity, which enables control of periodicity by varying film preparation conditions. This work expands knowledge about self-organizing reaction-diffusion systems and offers a strategy for the design of self-organizing materials.
- Published
- 2021
37. Nanofibrillar Hydrogel Recapitulates Changes Occurring in the Fibrotic Extracellular Matrix
- Author
-
Elisabeth Prince, Zhengkun Chen, Nancy Khuu, and Eugenia Kumacheva
- Subjects
food.ingredient ,Polymers and Plastics ,Bioengineering ,macromolecular substances ,02 engineering and technology ,010402 general chemistry ,complex mixtures ,01 natural sciences ,Gelatin ,Biomaterials ,Extracellular matrix ,Mechanobiology ,food ,Fibrosis ,Materials Chemistry ,medicine ,Humans ,Cellulose ,Chemistry ,technology, industry, and agriculture ,Hydrogels ,021001 nanoscience & nanotechnology ,medicine.disease ,Biocompatible material ,In vitro ,0104 chemical sciences ,Extracellular Matrix ,Self-healing hydrogels ,Biophysics ,Collagen ,Tissue stiffness ,0210 nano-technology - Abstract
Fibrosis is a pathological condition that leads to excessive deposition of collagen and increased tissue stiffness. Understanding the mechanobiology of fibrotic tissue necessitates the development of effective in vitro models that recapitulate its properties and structure; however, hydrogels that are currently used for this purpose fail to mimic the filamentous structure and mechanical properties of the fibrotic extracellular matrix (ECM). Here, we report a nanofibrillar hydrogel composed of cellulose nanocrystals and gelatin, which addresses this challenge. By altering the composition of the hydrogel, we mimicked the changes in structure, mechanical properties, and chemistry of fibrotic ECM. Furthermore, we decoupled the variations in hydrogel structure, properties, and ligand concentration. We demonstrate that this biocompatible hydrogel supports the three-dimensional culture of cells relevant to fibrotic diseases. This versatile hydrogel can be used for in vitro studies of fibrosis of different tissues, thus enabling the development of novel treatments for fibrotic diseases.
- Published
- 2021
38. Matrix Stiffness-Regulated Growth of Breast Tumor Spheroids and Their Response to Chemotherapy
- Author
-
Albert Gevorkian, Yunfeng Li, Ningtong Zhang, Alison P. McGuigan, Huachen Tao, Eugenia Kumacheva, Zhengkun Chen, Nancy Khuu, and Elisabeth Prince
- Subjects
Polymers and Plastics ,Cell Culture Techniques ,Bioengineering ,Breast Neoplasms ,macromolecular substances ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biomaterials ,Extracellular matrix ,Breast cancer ,Spheroids, Cellular ,Materials Chemistry ,medicine ,Tumor Microenvironment ,Humans ,Doxorubicin ,Cell adhesion ,Chemistry ,technology, industry, and agriculture ,Spheroid ,Cancer ,Hydrogels ,021001 nanoscience & nanotechnology ,medicine.disease ,0104 chemical sciences ,Extracellular Matrix ,Cell culture ,embryonic structures ,Self-healing hydrogels ,Biophysics ,Female ,0210 nano-technology ,medicine.drug - Abstract
Interactions between tumor cells and the extracellular matrix (ECM) are an important factor contributing to therapy failure in cancer patients. Current in vitro breast cancer spheroid models examining the role of mechanical properties on spheroid response to chemotherapy are limited by the use of two-dimensional cell culture, as well as simultaneous variation in hydrogel matrix stiffness and other properties, e.g., hydrogel composition, pore size, and cell adhesion ligand density. In addition, currently used hydrogel matrices do not replicate the filamentous ECM architecture in a breast tumor microenvironment. Here, we report a collagen-alginate hydrogel with a filamentous architecture and a 20-fold variation in stiffness, achieved independently of other properties, used for the evaluation of estrogen receptor-positive breast cancer spheroid response to doxorubicin. The variation in hydrogel mechanical properties was achieved by altering the degree of cross-linking of alginate molecules. We show that soft hydrogels promote the growth of larger MCF-7 tumor spheroids with a lower fraction of proliferating cells and enhance spheroid resistance to doxorubicin. Notably, the stiffness-dependent chemotherapeutic response of the spheroids was temporally mediated: it became apparent at sufficiently long cell culture times, when the matrix stiffness has influenced the spheroid growth. These findings highlight the significance of decoupling matrix stiffness from other characteristics in studies of chemotherapeutic resistance of tumor spheroids and in development of drug screening platforms.
- Published
- 2020
39. Simultaneous generation of droplets with different dimensions in parallel integrated microfluidic droplet generators
- Author
-
Craig A. Simmons, Edmond W. K. Young, Minseok Seo, Eugenia Kumacheva, Piotr Garstecki, Zhihong Nie, and Wei Li
- Subjects
Physics::Fluid Dynamics ,Generator (circuit theory) ,Coupling ,Materials science ,Flow (psychology) ,Microfluidics ,Analytical chemistry ,General Chemistry ,Mechanics ,Condensed Matter Physics ,Parametric statistics - Abstract
This paper describes geometric coupling of the dynamics of break-up of liquid threads in parallel flow-focusing devices (FFD), which are integrated into a multiple quadruple-microfluidic droplet generator (QDG). We show weak parametric coupling between parallel FFDs with an identical design, which leads to the slight broadening of the distribution of sizes of droplets. Using parallel FFDs with distinct geometries we simultaneously generated several populations of droplets with different volumes, yet, each of these populations was characterized by a narrow size distribution. Simulation of the generation of droplets in the quadruple-microfluidic droplet generator based on hydraulic resistances to the flow of a single-phase fluid was in good agreement with the experimental results.
- Published
- 2020
40. Microfluidic consecutive flow-focusing droplet generators
- Author
-
Shengqing Xu, Minseok Seo, Zhihong Nie, Eugenia Kumacheva, and Chantal Paquet
- Subjects
Physics::Fluid Dynamics ,endocrine system ,Flow focusing ,Chemical engineering ,Microfluidics ,technology, industry, and agriculture ,Physics::Atomic and Molecular Clusters ,Nanotechnology ,General Chemistry ,Condensed Matter Physics ,complex mixtures ,eye diseases - Abstract
This article describes emulsification in a microfluidic double droplet generator (DDR) comprising two consecutive flow-focusing devices with locally modified surface chemistry. We generated W/O/W, O/O/W and O/W/O double emulsions with precisely controlled sizes and morphology of droplets. Secondly, by combining two mechanisms of droplet formation (the flow-focusing mechanism and the break up of liquid threads at T-junction) we produced multiple populations of droplets with varying size and/or composition. These droplets were used as the structural units for the formation of complex dynamic lattices.
- Published
- 2020
41. Biomimetic hydrogel supports initiation and growth of patient-derived breast tumor organoids
- Author
-
Elisabeth Prince, Jennifer Cruickshank, Wail Ba-Alawi, Kelsey Hodgson, Jillian Haight, Chantal Tobin, Andrew Wakeman, Alona Avoulov, Valentina Topolskaia, Mitchell J. Elliott, Alison P. McGuigan, Hal K. Berman, Benjamin Haibe-Kains, David W. Cescon, and Eugenia Kumacheva
- Subjects
Organoids ,Mice ,Multidisciplinary ,Biomimetics ,General Physics and Astronomy ,Animals ,Humans ,Breast Neoplasms ,Female ,Hydrogels ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
Patient-derived tumor organoids (PDOs) are a highly promising preclinical model that recapitulates the histology, gene expression, and drug response of the donor patient tumor. Currently, PDO culture relies on basement-membrane extract (BME), which suffers from batch-to-batch variability, the presence of xenogeneic compounds and residual growth factors, and poor control of mechanical properties. Additionally, for the development of new organoid lines from patient-derived xenografts, contamination of murine host cells poses a problem. We propose a nanofibrillar hydrogel (EKGel) for the initiation and growth of breast cancer PDOs. PDOs grown in EKGel have histopathologic features, gene expression, and drug response that are similar to those of their parental tumors and PDOs in BME. In addition, EKGel offers reduced batch-to-batch variability, a range of mechanical properties, and suppressed contamination from murine cells. These results show that EKGel is an improved alternative to BME matrices for the initiation, growth, and maintenance of breast cancer PDOs.
- Published
- 2020
42. Morphological Transitions in Patchy Nanoparticles
- Author
-
Christian Rossner, Elizabeth Galati, Huachen Tao, Ekaterina B. Zhulina, and Eugenia Kumacheva
- Subjects
Coalescence (physics) ,chemistry.chemical_classification ,Morphology (linguistics) ,Materials science ,General Engineering ,General Physics and Astronomy ,Nanoparticle ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Micelle ,0104 chemical sciences ,Colloid ,chemistry ,Chemical physics ,Desorption ,Molecule ,General Materials Science ,0210 nano-technology - Abstract
Nanoparticles (NPs) decorated with topographically or chemically distinct surface patches are an emerging class of colloidal building blocks of functional hierarchical materials. Surface segregation of polymer ligands into pinned micelles offers a strategy for the generation of patchy NPs with controlled spatial distribution and number of patches. The thermodynamic nature of this approach poses a question about the stability of multiple patches on the NP surface, as the lowest energy state is expected for NPs carrying a single patch. In the present work, for gold NPs end-grafted with thiol-terminated polymer molecules, we show that the patchy surface morphology is preserved under conditions of strong grafting of the thiol groups to the NP surface (i.e., up to a temperature of 40 °C), although the patch shape changes over time. At higher temperatures (e.g., at 80 °C), the number of patches per NP decreases, due to the increased lateral mobility and coalescence of the patches as well as the ultimate loss of the polymer ligands due to desorption at enhanced solvent quality. The experimental results were rationalized theoretically, using a scaling approach. The results of this work offer insight into the surface science of patchy nanocolloids and specify the time and temperature ranges of the applications of patchy NPs.
- Published
- 2020
43. Carbon Dots Conjugated with Vascular Endothelial Growth Factor for Protein Tracking in Angiogenic Therapy
- Author
-
Azadeh Ghaee, Mahshid Chekini, Ali Abouei Mehrizi, Eugenia Kumacheva, Hamideh Basiri, and Mehdi Farokhi
- Subjects
Vascular Endothelial Growth Factor A ,Cell Survival ,medicine.medical_treatment ,Neovascularization, Physiologic ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Umbilical vein ,chemistry.chemical_compound ,Western blot ,Tissue engineering ,Cell Movement ,Quantum Dots ,Electrochemistry ,medicine ,Human Umbilical Vein Endothelial Cells ,Humans ,General Materials Science ,Spectroscopy ,Fluorescent Dyes ,Tube formation ,Microscopy, Confocal ,medicine.diagnostic_test ,Chemistry ,Growth factor ,Cell migration ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,In vitro ,Carbon ,0104 chemical sciences ,Vascular endothelial growth factor ,Microscopy, Fluorescence ,Biophysics ,0210 nano-technology - Abstract
One of the challenges of using growth factors for tissue regeneration is to monitor their biodistributions and delivery to injured tissues for minimally invasive detection. In the present study, tracking of human vascular endothelial growth factor (VEGF) was achieved by chemically linking it to photoluminescent carbon dots (CDs). Carbon dots were synthesized by the hydrothermal method and, subsequently, conjugated with VEGF using carbodiimide coupling. ELISA and western blot analysis revealed that VEGF-conjugated CDs preserve the binding affinity of VEGF to its antibodies. We also show that VEGF-conjugated CDs maintain the functionality of VEGF for tube formation and cell migration. The VEGF-conjugated CDs were also used for in vitro imaging of human umbilical vein endothelial cells. The results of this work suggest that cell-penetrating VEGF-conjugated CDs can be used for growth factor protein tracking in therapeutic and tissue engineering applications.
- Published
- 2020
44. Self-limiting directional nanoparticle bonding governed by reaction stoichiometry
- Author
-
Eugenia Kumacheva, Chenglin Yi, Shaoyi Zhang, Zhong-Yuan Lu, Yan Zhang, Yiqun Yang, Zhihong Nie, and Hong Liu
- Subjects
chemistry.chemical_classification ,Multidisciplinary ,Materials science ,Nanostructure ,chemistry ,Covalent bond ,Chemical physics ,Nanoparticle ,Molecule ,Polymer ,Electrostatics ,Order of magnitude ,Nanomaterials - Abstract
Nanoparticle clusters with molecular-like configurations are an emerging class of colloidal materials. Particles decorated with attractive surface patches acting as analogs of functional groups are used to assemble colloidal molecules (CMs); however, high-yield generation of patchy nanoparticles remains a challenge. We show that for nanoparticles capped with complementary reactive polymers, a stoichiometric reaction leads to reorganization of the uniform ligand shell and self-limiting nanoparticle bonding, whereas electrostatic repulsion between colloidal bonds governs CM symmetry. This mechanism enables high-yield CM generation and their programmable organization in hierarchical nanostructures. Our work bridges the gap between covalent bonding taking place at an atomic level and colloidal bonding occurring at the length scale two orders of magnitude larger and broadens the methods for nanomaterial fabrication.
- Published
- 2020
45. Bipolar-shell resurfacing for blue LEDs based on strongly confined perovskite quantum dots
- Author
-
Yitong, Dong, Ya-Kun, Wang, Fanglong, Yuan, Andrew, Johnston, Yuan, Liu, Dongxin, Ma, Min-Jae, Choi, Bin, Chen, Mahshid, Chekini, Se-Woong, Baek, Laxmi Kishore, Sagar, James, Fan, Yi, Hou, Mingjian, Wu, Seungjin, Lee, Bin, Sun, Sjoerd, Hoogland, Rafael, Quintero-Bermudez, Hinako, Ebe, Petar, Todorovic, Filip, Dinic, Peicheng, Li, Hao Ting, Kung, Makhsud I, Saidaminov, Eugenia, Kumacheva, Erdmann, Spiecker, Liang-Sheng, Liao, Oleksandr, Voznyy, Zheng-Hong, Lu, and Edward H, Sargent
- Abstract
Colloidal quantum dot (QD) solids are emerging semiconductors that have been actively explored in fundamental studies of charge transport
- Published
- 2019
46. Temperature-Responsive Self-Assembly of Nanoparticles Grafted with UCST Polymer Ligands
- Author
-
Huachen Tao, Elizabeth Galati, and Eugenia Kumacheva
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Nanoparticle ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Chemical engineering ,chemistry ,Upper critical solution temperature ,Materials Chemistry ,0210 nano-technology ,Self-assembly of nanoparticles - Abstract
Temperature-responsive self-assembly (TRSA) of polymer-stabilized nanoparticles is a promising method that is useful for many applications. Currently, polymers ligands with a lower critical solutio...
- Published
- 2018
47. Patterning of Structurally Anisotropic Composite Hydrogel Sheets
- Author
-
Elisabeth Prince, Moien Alizadehgiashi, Melissa Campbell, Nancy Khuu, Alexandra Albulescu, Kevin De France, Dimitrije Ratkov, Yunfeng Li, Todd Hoare, and Eugenia Kumacheva
- Subjects
food.ingredient ,Materials science ,Polymers and Plastics ,Composite number ,Nanofibers ,3D printing ,Microextrusion ,Bioengineering ,02 engineering and technology ,Regenerative Medicine ,010402 general chemistry ,01 natural sciences ,Gelatin ,Hydrogel, Polyethylene Glycol Dimethacrylate ,Biomaterials ,food ,Tissue engineering ,Materials Chemistry ,Humans ,Cellulose ,Tissue Engineering ,business.industry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemical engineering ,Permeability (electromagnetism) ,Self-healing hydrogels ,Anisotropy ,Nanoparticles ,Extrusion ,0210 nano-technology ,business - Abstract
Compositional and structural patterns play a crucial role in the function of many biological tissues. In the present work, for nanofibrillar hydrogels formed by chemically cross-linked cellulose nanocrystals (CNC) and gelatin, we report a microextrusion-based 3D printing method to generate structurally anisotropic hydrogel sheets with CNCs aligned in the direction of extrusion. We prepared hydrogels with a uniform composition, as well as hydrogels with two different types of compositional gradients. In the first type of gradient hydrogel, the composition of the sheet varied parallel to the direction of CNC alignment. In the second hydrogel type, the composition of the sheet changed orthogonally to the direction of CNC alignment. The hydrogels exhibited gradients in structure, mechanical properties, and permeability, all governed by the compositional patterns, as well as cytocompatibility. These hydrogels have promising applications for both fundamental research and for tissue engineering and regenerative medicine.
- Published
- 2018
48. Compound droplets derived from a cholesteric suspension of cellulose nanocrystals
- Author
-
Eugenia Kumacheva, Toyoko Suzuki, Albert Gevorkian, and Yunfeng Li
- Subjects
Materials science ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Suspension (chemistry) ,Surface tension ,chemistry.chemical_compound ,Colloid ,Monomer ,Chemical engineering ,chemistry ,Liquid crystal ,Phase (matter) ,Janus ,Soft matter ,0210 nano-technology - Abstract
This study reports microfluidic generation of Janus droplets that consist of a liquid crystal component (a cholesteric aqueous suspension of cellulose nanocrystals, Ch-CNC) and a mineral oil (MO) component. The composition of the droplets was controlled by varying the relative flow rates of MO and Ch-CNC suspension. The shape of the Ch-CNC component of the droplets was changed from a truncated sphere to a hemisphere to a crescent moon. For these three Ch-CNC phase shapes, the Ch packing of the CNC pseudolayers was preserved, however the Ch pitch reduced, which was ascribed to the change in CNC orientation at the Ch-CNC/MO interface from perpendicular to parallel. The shape of the compound droplets was tuned from a dumbbell to a sphere by reducing interfacial tension between the Ch-CNC suspension and MO phases. Photopolymerization of the monomer mixture introduced in the Ch-CNC phase of the droplets and the removal of the sacrificial MO phase enabled the generation of Ch microgels. The results of this work can be used for exploring new applications of Janus colloids and the fabrication of programmable active soft matter.
- Published
- 2018
49. Shear-Induced Alignment of Anisotropic Nanoparticles in a Single-Droplet Oscillatory Microfluidic Platform
- Author
-
Yunfeng Li, Amir Khabibullin, Elisabeth Prince, Moien Alizadehgiashi, Milad Abolhasani, and Eugenia Kumacheva
- Subjects
Materials science ,Fabrication ,Isotropy ,Microfluidics ,Nanoparticle ,Anisotropic nanoparticles ,Nanotechnology ,02 engineering and technology ,Surfaces and Interfaces ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Condensed Matter::Soft Condensed Matter ,Physics::Fluid Dynamics ,Shear rate ,Shear (geology) ,Electrochemistry ,General Materials Science ,0210 nano-technology ,Anisotropy ,Spectroscopy - Abstract
Flow-induced alignment of shape-anisotropic colloidal particles is of great importance in fundamental research and in the fabrication of structurally anisotropic materials; however, rheo-optical studies of shear-induced particle orientation are time- and labor-intensive and require complicated experimental setups. We report a single-droplet oscillatory microfluidic strategy integrated with in-line polarized light imaging as a strategy for studies of shear-induced alignment of rod-shape nanoparticles. Using an oscillating droplet of an aqueous isotropic suspension of cellulose nanocrystals (CNCs), we explore the effect of the shear rate and suspension viscosity on the flow-induced CNC alignment and subsequent relaxation to the isotropic state. The proposed microfluidic strategy enables high-throughput studies of shear-induced orientations in structured liquid under precisely controlled experimental conditions. The results of such studies can be used in the development of structure-anisotropic materials.
- Published
- 2017
50. Microfluidic Arrays of Breast Tumor Spheroids for Drug Screening and Personalized Cancer Therapies
- Author
-
Valentina Topolskaia, Yihe Wang, Jennifer Cruickshank, Eugenia Kumacheva, David W. Cescon, Fei Xu, Sina Kheiri, Huachen Tao, Edmond W. K. Young, Elisabeth Prince, and Alison P. McGuigan
- Subjects
Drug ,medicine.medical_treatment ,media_common.quotation_subject ,Microfluidics ,Drug Evaluation, Preclinical ,Biomedical Engineering ,Pharmaceutical Science ,Breast Neoplasms ,Biomaterials ,Breast cancer ,In vivo ,Cell Line, Tumor ,Spheroids, Cellular ,Tumor Microenvironment ,Humans ,Medicine ,Early Detection of Cancer ,media_common ,Chemotherapy ,Tumor microenvironment ,business.industry ,Spheroid ,Cancer ,medicine.disease ,embryonic structures ,Cancer research ,Female ,Personalized medicine ,business - Abstract
One of the obstacles limiting progress in the development of effective cancer therapies is the shortage of preclinical models that capture the dynamic nature of tumor microenvironments. Interstitial flow strongly impacts tumor response to chemotherapy; however, conventional in vitro cancer models largely disregard this key feature. Here, a proof of principle microfluidic platform for the generation of large arrays of breast tumor spheroids that are grown under close-to-physiological flow in a biomimetic hydrogel is reported. This cancer spheroids-on-a-chip model is used for time- and labor-efficient studies of the effects of drug dose and supply rate on the chemosensitivity of breast tumor spheroids. The capability to grow large arrays of tumor spheroids from patient-derived cells of different breast cancer subtypes is shown, and the correlation between in vivo drug efficacy and on-chip spheroid drug response is demonstrated. The proposed platform can serve as an in vitro preclinical model for the development of personalized cancer therapies and effective screening of new anticancer drugs.
- Published
- 2021
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