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Biofabrication Aug 2020Current microfluidic methods for cell-laden microfiber fabrication generally require larger than 100 μl of cell-suspensions. Since some 'rare' cells can be only...
Current microfluidic methods for cell-laden microfiber fabrication generally require larger than 100 μl of cell-suspensions. Since some 'rare' cells can be only acquired in small amounts, the preparation of >100 μl cell-suspensions with high-cell density can be both expensive and time consuming. Here, we present a facile method capable of fabricating cell-laden microfibers using small-volume cell-suspensions. The method utilizes a 3D-printed coaxial microfluidic device featured with a 'luer-lock inlet' to effectively load cell-suspensions in a deterministic volume (down to 5 μl) with a low sample-loss. In experiments, we demonstrate the formation of fibrous tissues consisting of various kinds of cells. Investigations on the morphology and function of the encapsulated cells show the viability of the cells is not significantly affected by the fabrication process, and also indicate the potential of using our method to perform quantitative assays on fiber-shaped tissues, while reducing the overall material and time consumption.
Topics: Animals; Hep G2 Cells; Humans; Microfluidics; Microtechnology; Rats; Reproducibility of Results
PubMed: 32299072
DOI: 10.1088/1758-5090/ab89cb -
Theranostics 2023Micro/nanomotors are containers that pass through liquid media and carry cargo. Because they are tiny, micro/nanomotors exhibit excellent potential for biosensing and... (Review)
Review
Micro/nanomotors are containers that pass through liquid media and carry cargo. Because they are tiny, micro/nanomotors exhibit excellent potential for biosensing and disease treatment applications. However, their size also makes overcoming random Brownian forces very challenging for micro/nanomotors moving on targets. Additionally, to achieve desired practical applications, the expensive materials, short lifetimes, poor biocompatibility, complex preparation methods, and side effects of micro/nanomotors must be addressed, and potential adverse effects must be evaluated both and in practical applications. This has led to the continuous development of key materials for driving micro/nanomotors. In this work, we review the working principles of micro/nanomotors. Metallic and nonmetallic nanocomplexes, enzymes, and living cells are explored as key materials for driving micro/nanomotors. We also consider the effects of exogenous stimulations and endogenous substance conditions on micro/nanomotor motions. The discussion focuses on micro/nanomotor applications in biosensing, treating cancer and gynecological diseases, and assisted fertilization. By addressing micro/nanomotor shortcomings, we propose directions for further developing and applying micro/nanomotors.
Topics: Biosensing Techniques; Microtechnology; Nanotechnology
PubMed: 37284438
DOI: 10.7150/thno.81845 -
Advanced Materials (Deerfield Beach,... Jun 2023Cartilage degeneration is among the fundamental reasons behind disability and pain across the globe. Numerous approaches have been employed to treat cartilage diseases.... (Review)
Review
Cartilage degeneration is among the fundamental reasons behind disability and pain across the globe. Numerous approaches have been employed to treat cartilage diseases. Nevertheless, none have shown acceptable outcomes in the long run. In this regard, the convergence of tissue engineering and microfabrication principles can allow developing more advanced microfluidic technologies, thus offering attractive alternatives to current treatments and traditional constructs used in tissue engineering applications. Herein, the current developments involving microfluidic hydrogel-based scaffolds, promising structures for cartilage regeneration, ranging from hydrogels with microfluidic channels to hydrogels prepared by the microfluidic devices, that enable therapeutic delivery of cells, drugs, and growth factors, as well as cartilage-related organ-on-chips are reviewed. Thereafter, cartilage anatomy and types of damages, and present treatment options are briefly overviewed. Various hydrogels are introduced, and the advantages of microfluidic hydrogel-based scaffolds over traditional hydrogels are thoroughly discussed. Furthermore, available technologies for fabricating microfluidic hydrogel-based scaffolds and microfluidic chips are presented. The preclinical and clinical applications of microfluidic hydrogel-based scaffolds in cartilage regeneration and the development of cartilage-related microfluidic chips over time are further explained. The current developments, recent key challenges, and attractive prospects that should be considered so as to develop microfluidic systems in cartilage repair are highlighted.
Topics: Hydrogels; Tissue Engineering; Microfluidics; Cartilage; Microtechnology; Tissue Scaffolds
PubMed: 36633376
DOI: 10.1002/adma.202208852 -
Biomedical Microdevices Mar 2019Engineered microscale hydrogels have emerged as promising therapeutic approaches for the treatment of various diseases. These microgels find wide application in the... (Review)
Review
Engineered microscale hydrogels have emerged as promising therapeutic approaches for the treatment of various diseases. These microgels find wide application in the biomedical field because of the ease of injectability, controlled release of therapeutics, flexible means of synthesis, associated tunability, and can be engineered as stimuli-responsive. While bulk hydrogels of several length-scale dimensions have been used for over two decades in drug delivery applications, their use as microscale carriers of drug and cell-based therapies is relatively new. Herein, we critically summarize the fundamentals of hydrogels based on their equilibrium and dynamics of their molecular structure, as well as solute diffusion as it relates to drug delivery. In addition, examples of common microgel synthesis techniques are provided. The ability to tune microscale hydrogels to obtain controlled release of therapeutics is discussed, along with microgel considerations for cell encapsulation as it relates to the development of cell-based therapies. We conclude with an outlook on the use of microgels for cell sequencing, and the convergence of the use of microscale hydrogels for drug delivery, cell therapy, and cell sequencing based systems.
Topics: Cell- and Tissue-Based Therapy; Drug Delivery Systems; Engineering; Humans; Hydrogels; Microtechnology; Sequence Analysis
PubMed: 30904963
DOI: 10.1007/s10544-019-0358-0 -
Journal of Laboratory Automation Apr 2015Well-designed microfluidic platforms can be excellent tools to eliminate bottleneck problems or issues that have arisen in biological fields by providing unprecedented... (Review)
Review
Well-designed microfluidic platforms can be excellent tools to eliminate bottleneck problems or issues that have arisen in biological fields by providing unprecedented high-resolution control of mechanical and chemical microenvironments for cell culture. Among such microtechnologies, the precise generation of biochemical concentration gradients has been highly regarded in the biorelated scientific fields; even today, the principles and mechanisms for gradient generation continue to be refined, and the number of applications for this technique is growing. Here, we review the current status of the concentration gradient generation technologies achieved in various microplatforms and how they have been and will be applied to biological issues, particularly those that have arisen from cancer research, stem cell research, and tissue engineering. We also provide information about the advances and future challenges in the technological aspects of microscale concentration gradient generation.
Topics: Biomedical Research; Cytological Techniques; Microfluidic Analytical Techniques; Microtechnology; Tissue Engineering
PubMed: 25510472
DOI: 10.1177/2211068214562247 -
Lab on a Chip May 2016Biomechanical forces have been demonstrated to influence a plethora of neuronal functions across scales including gene expression, mechano-sensitive ion channels,... (Review)
Review
Biomechanical forces have been demonstrated to influence a plethora of neuronal functions across scales including gene expression, mechano-sensitive ion channels, neurite outgrowth and folding of the cortices in the brain. However, the detailed roles biomechanical forces may play in brain development and disorders has seen limited study, partly due to a lack of effective methods to probe the mechano-biology of the brain. Current techniques to apply biomechanical forces on neurons often suffer from low throughput and poor spatiotemporal resolution. On the other hand, newly developed micro- and nano-technologies can overcome these aforementioned limitations and offer advantages such as lower cost and possibility of non-invasive control of neuronal circuits. This review compares the range of conventional, micro- and nano-technological techniques that have been developed and how they have been or can be used to understand the effect of biomechanical forces on neuronal development and homeostasis.
Topics: Animals; Biomechanical Phenomena; Brain; Humans; Mechanical Phenomena; Microtechnology; Nanotechnology
PubMed: 27161943
DOI: 10.1039/c6lc00349d -
Methods in Molecular Biology (Clifton,... 2018Quantification of single-cell proteomics provides key insights in the field of cellular heterogeneity. This chapter discusses the emerging techniques that are being used... (Review)
Review
Quantification of single-cell proteomics provides key insights in the field of cellular heterogeneity. This chapter discusses the emerging techniques that are being used to measure the protein copy numbers at the single-cell level, which includes flow cytometry, mass cytometry, droplet cytometry, microengraving, and single-cell barcoding microchip. The advantages and limitations of each technique are compared, and future research opportunities are highlighted.
Topics: Flow Cytometry; Humans; Mass Spectrometry; Microfluidic Analytical Techniques; Microtechnology; Protein Array Analysis; Proteins; Proteomics; Single-Cell Analysis
PubMed: 29536450
DOI: 10.1007/978-1-4939-7717-8_17 -
Analytical and Bioanalytical Chemistry Jul 2016Miniaturized electrochemical in vivo biosensors allow the measurement of fast extracellular dynamics of neurotransmitter and energy metabolism directly in the tissue.... (Review)
Review
Miniaturized electrochemical in vivo biosensors allow the measurement of fast extracellular dynamics of neurotransmitter and energy metabolism directly in the tissue. Enzyme-based amperometric biosensing is characterized by high specificity and precision as well as high spatial and temporal resolution. Aside from glucose monitoring, many systems have been introduced mainly for application in the central nervous system in animal models. We compare the microsensor principle with other methods applied in biomedical research to show advantages and drawbacks. Electrochemical sensor systems are easily miniaturized and fabricated by microtechnology processes. We review different microfabrication approaches for in vivo sensor platforms, ranging from simple modified wires and fibres to fully microfabricated systems on silicon, ceramic or polymer substrates. The various immobilization methods for the enzyme such as chemical cross-linking and entrapment in polymer membranes are discussed. The resulting sensor performance is compared in detail. We also examine different concepts to reject interfering substances by additional membranes, aspects of instrumentation and biocompatibility. Practical considerations are elaborated, and conclusions for future developments are presented. Graphical Abstract ᅟ.
Topics: Animals; Biosensing Techniques; Enzymes; Equipment Design; Microtechnology
PubMed: 26935934
DOI: 10.1007/s00216-016-9420-4 -
Journal of Biomechanics Jul 2016One of the most popular methods to fabricate biomedical microfluidic devices is by using a soft-lithography technique. However, the fabrication of the moulds to produce... (Review)
Review
One of the most popular methods to fabricate biomedical microfluidic devices is by using a soft-lithography technique. However, the fabrication of the moulds to produce microfluidic devices, such as SU-8 moulds, usually requires a cleanroom environment that can be quite costly. Therefore, many efforts have been made to develop low-cost alternatives for the fabrication of microstructures, avoiding the use of cleanroom facilities. Recently, low-cost techniques without cleanroom facilities that feature aspect ratios more than 20, for fabricating those SU-8 moulds have been gaining popularity among biomedical research community. In those techniques, Ultraviolet (UV) exposure equipment, commonly used in the Printed Circuit Board (PCB) industry, replaces the more expensive and less available Mask Aligner that has been used in the last 15 years for SU-8 patterning. Alternatively, non-lithographic low-cost techniques, due to their ability for large-scale production, have increased the interest of the industrial and research community to develop simple, rapid and low-cost microfluidic structures. These alternative techniques include Print and Peel methods (PAP), laserjet, solid ink, cutting plotters or micromilling, that use equipment available in almost all laboratories and offices. An example is the xurography technique that uses a cutting plotter machine and adhesive vinyl films to generate the master moulds to fabricate microfluidic channels. In this review, we present a selection of the most recent lithographic and non-lithographic low-cost techniques to fabricate microfluidic structures, focused on the features and limitations of each technique. Only microfabrication methods that do not require the use of cleanrooms are considered. Additionally, potential applications of these microfluidic devices in biomedical engineering are presented with some illustrative examples.
Topics: Biomedical Technology; Costs and Cost Analysis; Lab-On-A-Chip Devices; Microfluidics; Microtechnology
PubMed: 26671220
DOI: 10.1016/j.jbiomech.2015.11.031 -
Biofabrication Oct 2023Neural tissues react to injuries through the orchestration of cellular reprogramming, generating specialized cells and activating gene expression that helps with tissue... (Review)
Review
Neural tissues react to injuries through the orchestration of cellular reprogramming, generating specialized cells and activating gene expression that helps with tissue remodeling and homeostasis. Simplified biomimetic models are encouraged to amplify the physiological and morphological changes during neural regeneration at cellular and molecular levels. Recent years have witnessed growing interest in lab-on-a-chip technologies for the fabrication of neural interfaces. Neural system-on-a-chip devices are promisingmicrophysiological platforms that replicate the key structural and functional characteristics of neural tissues. Microfluidics and microelectrode arrays are two fundamental techniques that are leveraged to address the need for microfabricated neural devices. In this review, we explore the innovative fabrication, mechano-physiological parameters, spatiotemporal control of neural cell cultures and chip-based neurogenesis. Although the high variability in different constructs, and the restriction in experimental and analytical access limit the real-life applications of microphysiological models, neural system-on-a-chip devices have gained considerable translatability for modeling neuropathies, drug screening and personalized therapy.
Topics: Microtechnology; Lab-On-A-Chip Devices; Microfluidics; Cell Culture Techniques; Nerve Tissue
PubMed: 37832555
DOI: 10.1088/1758-5090/ad032a