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Micromachines Feb 2022This study proposes a rapid and inexpensive thermocycler that enables rapid heating of samples using a thin glass chip and a cheap chip resistor to overcome the on-site...
This study proposes a rapid and inexpensive thermocycler that enables rapid heating of samples using a thin glass chip and a cheap chip resistor to overcome the on-site diagnostic limitations of polymerase chain reaction (PCR). Microchip PCR devices have emerged to miniaturize conventional PCR systems and reduce operation time and cost. In general, PCR microchips require a thin-film heater fabricated through a semiconductor process, which is a complicated process, resulting in high costs. Therefore, this investigation substituted a general chip resistor for a thin-film heater. The proposed thermocycler consists of a compact glass microchip of 12.5 mm × 12.5 mm × 2 mm that could hold a 2 μL PCR sample and a surface-mounted chip resistor of 6432 size (6.4 mm × 3.2 mm). Improving heat transfer from the chip resistor heater to the PCR reaction chamber in the microchip was accomplished via the design and fabrication of a three-dimensional chip structure using selective laser-induced etching, a rapid prototyping technique that allowed to be embedded. The fabricated PCR microchip was combined with a thermistor temperature sensor, a blower fan, and a microcontroller. The assembled thermocycler could heat the sample at a maximum rate of 28.8 °C/s per second. When compared with a commercially available PCR apparatus running the same PCR protocol, the total PCR operating time with a DNA sample was reduced by about 20%.
PubMed: 35208463
DOI: 10.3390/mi13020339 -
Micromachines Feb 2021Anthocyanins are antioxidant and anti-inflammatory ingredients in various fruit beverages, for which their conservation and quantitation are important for the food...
Anthocyanins are antioxidant and anti-inflammatory ingredients in various fruit beverages, for which their conservation and quantitation are important for the food industry. In this paper, we report a simple, portable device for accurate on-site determination of total monomeric anthocyanins in fruit beverages employing a Wi-Fi scanner coupled with a flexible microchip and a free mobile app. The detection principle is based on the pH-induced colorimetric reactions of anthocyanins performed in a specially designed microchip and validated with standard spectrophotometric measurements. The microchip with multiple testing vials was prepared with the benchtop molding method with a common PDMS elastomer and a transparency film; the photo of the scanned microchip is wirelessly sent to a smartphone and the RGB values of individual reaction vials in the microchip are analyzed with a free mobile app to determine the corresponding concentrations. It was demonstrated that the quantitation performance of this POCT device is comparable with conventional spectrophotometry in the determination of total anthocyanins in both standard solutions and fruit beverages.
PubMed: 33670979
DOI: 10.3390/mi12030246 -
Biosensors Feb 2023The detection of pathogens in food substances is of crucial concern for public health and for the safety of the natural environment. Nanomaterials, with their high... (Review)
Review
The detection of pathogens in food substances is of crucial concern for public health and for the safety of the natural environment. Nanomaterials, with their high sensitivity and selectivity have an edge over conventional organic dyes in fluorescent-based detection methods. Advances in microfluidic technology in biosensors have taken place to meet the user criteria of sensitive, inexpensive, user-friendly, and quick detection. In this review, we have summarized the use of fluorescence-based nanomaterials and the latest research approaches towards integrated biosensors, including microsystems containing fluorescence-based detection, various model systems with nano materials, DNA probes, and antibodies. Paper-based lateral-flow test strips and microchips as well as the most-used trapping components are also reviewed, and the possibility of their performance in portable devices evaluated. We also present a current market-available portable system which was developed for food screening and highlight the future direction for the development of fluorescence-based systems for on-site detection and stratification of common foodborne pathogens.
Topics: Food Safety; Nanostructures; Antibodies; Biosensing Techniques
PubMed: 36832016
DOI: 10.3390/bios13020249 -
Accounts of Chemical Research Oct 2014Circulating tumor cells (CTCs) are cancer cells that break away from either a primary tumor or a metastatic site and circulate in the peripheral blood as the cellular... (Review)
Review
Circulating tumor cells (CTCs) are cancer cells that break away from either a primary tumor or a metastatic site and circulate in the peripheral blood as the cellular origin of metastasis. With their role as a "tumor liquid biopsy", CTCs provide convenient access to all disease sites, including that of the primary tumor and the site of fatal metastases. It is conceivable that detecting and analyzing CTCs will provide insightful information in assessing the disease status without the flaws and limitations encountered in performing conventional tumor biopsies. However, identifying CTCs in patient blood samples is technically challenging due to the extremely low abundance of CTCs among a large number of hematologic cells. To address this unmet need, there have been significant research endeavors, especially in the fields of chemistry, materials science, and bioengineering, devoted to developing CTC detection, isolation, and characterization technologies. Inspired by the nanoscale interactions observed in the tissue microenvironment, our research team at UCLA pioneered a unique concept of "NanoVelcro" cell-affinity substrates, in which CTC capture agent-coated nanostructured substrates were utilized to immobilize CTCs with high efficiency. The working mechanism of NanoVelcro cell-affinity substrates mimics that of Velcro: when the two fabric strips of a Velcro fastener are pressed together, tangling between the hairy surfaces on two strips leads to strong binding. Through continuous evolution, three generations (gens) of NanoVelcro CTC chips have been established to achieve different clinical utilities. The first-gen NanoVelcro chip, composed of a silicon nanowire substrate (SiNS) and an overlaid microfluidic chaotic mixer, was created for CTC enumeration. Side-by-side analytical validation studies using clinical blood samples suggested that the sensitivity of first-gen NanoVelcro chip outperforms that of FDA-approved CellSearch. In conjunction with the use of the laser microdissection (LMD) technique, second-gen NanoVelcro chips (i.e., NanoVelcro-LMD), based on polymer nanosubstrates, were developed for single-CTC isolation. The individually isolated CTCs can be subjected to single-CTC genotyping (e.g., Sanger sequencing and next-generation sequencing, NGS) to verify the CTC's role as tumor liquid biopsy. Created by grafting of thermoresponsive polymer brushes onto SiNS, third-gen NanoVelcro chips (i.e., Thermoresponsive NanoVelcro) have demonstrated the capture and release of CTCs at 37 and 4 °C, respectively. The temperature-dependent conformational changes of polymer brushes can effectively alter the accessibility of the capture agent on SiNS, allowing for rapid CTC purification with desired viability and molecular integrity. This Account summarizes the continuous evolution of NanoVelcro CTC assays from the emergence of the original idea all the way to their applications in cancer research. We envision that NanoVelcro CTC assays will lead the way for powerful and cost-efficient diagnostic platforms for researchers to better understand underlying disease mechanisms and for physicians to monitor real-time disease progression.
Topics: Cell Separation; Humans; Microfluidic Analytical Techniques; Nanostructures; Neoplastic Cells, Circulating
PubMed: 25111636
DOI: 10.1021/ar5001617 -
Journal of Dairy Science Oct 2020Elevated temperature is often an indicator of an immune response and used in the diagnosis of illness in dairy calves; however, measuring rectal temperature is labor...
Elevated temperature is often an indicator of an immune response and used in the diagnosis of illness in dairy calves; however, measuring rectal temperature is labor intensive and often not measured daily on the farm. The objective of this study was to measure body temperature using a microchip and determine an appropriate implant site that would passively read body temperature in dairy calves. First, the precision of the temperature microchips and the rectal thermometer were tested ex vivo. Then, Holstein bull calves (n = 12) at 14 ± 12 d (mean ± SD) of age were implanted with microchips subcutaneously by the scutulum of the ear, subcutaneously in the upper scapula (SCAP), and intramuscularly in the trapezius muscle of the neck. One week after implantation, a temperature reading was taken for every microchip implant site using a radiofrequency ID (RFID) reader, as well as rectally and in the tympanic membrane using a digital thermometer every 60 min for 24 h in each calf (hereafter, the hourly study). Additionally, microchip readings and rectal temperatures were taken daily at 0800 h from 8 wk of age (n = 9; 57 ± 12 d of age) until 2 wk postweaning for a subset of the bull calves used in the hourly study (hereafter, the daily study). In the ex vivo trial, the microchip readings were very highly correlated with the rectal thermometer (r = 0.96), and the average coefficient of variation between microchip readings was very low (0.12 ± 0.03%). The relationships between the microchip readings within ear, SCAP, and neck and rectal and tympanic temperatures were analyzed using Pearson correlations and Bland-Altman plots. The ear and neck readings were strongly correlated for the hourly study [individual animal correlation; median (Q1, Q3), r = 0.78 (0.73, 0.84)] and for the daily study [r = 0.79 (0.73, 0.89)] across calves. However, rectal temperature was not significantly correlated with ear, SCAP, neck, or tympanic temperature for the daily and hourly studies. Results suggest that temperature microchips measure temperature appropriately, but temperature is dependent upon the implant site in calves, and temperature measured at ear, SCAP, and neck implant sites cannot be used to estimate rectal temperature. Future research should determine thresholds for fever that are specific to implant sites in calves.
Topics: Animals; Cattle; Male; Body Temperature; Cattle Diseases; Dairying; Fever; Implants, Experimental; Lab-On-A-Chip Devices; Neck; Rectum; Thermometers
PubMed: 32828511
DOI: 10.3168/jds.2019-17999 -
Medicina (Kaunas, Lithuania) Sep 2023: is a prevalent bacterium capable of inducing various infections, including skin and soft tissue infections, bloodstream infections, pneumonia, and surgical site... (Review)
Review
: is a prevalent bacterium capable of inducing various infections, including skin and soft tissue infections, bloodstream infections, pneumonia, and surgical site infections. The emergence of antimicrobial resistance in , particularly methicillin-resistant , has raised substantial concerns within global healthcare settings. Prior to antibiotic prescription, the ideal approach is antimicrobial susceptibility testing (AST); however, this is frequently perceived as excessively complex and time-intensive. Lab-on-a-chip (LOC) technology holds promise in addressing these challenges and advancing fundamental microbiological research while also aiding in the development of therapeutic strategies. This systematic review aims to evaluate the potential utility of LOC for AST of . : This study adhered to the PRISMA guidelines. Various databases, including SCOPUS, PubMed/MEDLINE, SCIELO, and LILACS, in addition to gray literature sources, were employed in the review process. : Sixteen studies were included in this systematic review. All these studies detailed the effectiveness, rapidity, and predictability of LOC systems for assessing susceptibility to various antibiotics. When comparing the LOC approach to traditional manual methods, it was evident that LOC requires a minimal quantity of reagents. Furthermore, most studies reported that the entire LOC procedure took 10 min to 7 h, with results being equally accurate as those obtained through traditional AST protocols. : The potential application of LOC for AST of is emphasized by its ability to provide rapid access to minimum inhibitory concentration data, which can substantially aid in selecting the most suitable antibiotics and dosages for treating challenging infections caused by this microorganism. Moreover, the rapid AST facilitated by LOC holds promise for enhancing the appropriateness and efficacy of therapy in clinical settings.
Topics: Humans; Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus; Anti-Bacterial Agents; Staphylococcal Infections; Lab-On-A-Chip Devices
PubMed: 37893437
DOI: 10.3390/medicina59101719 -
Scientific Reports Oct 2019While microfluidic systems model aspects of metastasis, they are limited to artificially created tissues of limited complexity. We set out to develop an in vitro model...
While microfluidic systems model aspects of metastasis, they are limited to artificially created tissues of limited complexity. We set out to develop an in vitro model of tumor cell migration from a primary tumor to a distant site that allows use of tissue. Accordingly, we created a macrofluidic model using culture plate wells connected with type I collagen-coated large bore tubing and has recirculating media. Green fluorescent protein-positive prostate carcinoma cells in a hydrogel or excised tumor xenografts from mice were placed into primary tumor sites and either human bone stromal cells (HS-5) in a hydrogel or human-derived bone chips were seeded into metastatic sites. Cells from the primary sites migrated to and grew in metastatic sites. Bone enhanced growth at metastatic sites and established a CXCL12 gradient that was higher in metastatic versus primary sites. AMD3100-mediated inhibition of CXCL12 function reduced the number of cells targeting the bone at the metastatic sites. In summary, we have developed a macrofluidic metastasis model that allows incorporation of tumor and metastatic microenvironment tissues and models chemotaxis. This system allows for incorporation of tumor heterogeneity and inclusion of an intact microenvironment. These features will facilitate identification of mechanisms and therapeutics for bone metastasis.
Topics: Animals; Bone Neoplasms; Cancellous Bone; Cell Movement; Chemokine CXCL12; Femur Head; Green Fluorescent Proteins; Heterografts; Humans; Hydrogels; Lab-On-A-Chip Devices; Male; Mice; Mice, Nude; Microchip Analytical Procedures; PC-3 Cells; Prostatic Neoplasms; Stromal Cells; Transduction, Genetic; Tumor Microenvironment
PubMed: 31628348
DOI: 10.1038/s41598-019-50577-3 -
Bioengineering (Basel, Switzerland) Oct 2022With the evolution of the pandemic caused by the Coronavirus disease of 2019 (COVID-19), reverse transcriptase-polymerase chain reactions (RT-PCR) have invariably been a...
With the evolution of the pandemic caused by the Coronavirus disease of 2019 (COVID-19), reverse transcriptase-polymerase chain reactions (RT-PCR) have invariably been a golden standard in clinical diagnosis. Nevertheless, the traditional polymerase chain reaction (PCR) is not feasible for field application due to its drawbacks, such as time-consuming and laboratory-based dependence. To overcome these challenges, a microchip-based ultrafast PCR system called SWM-02 was proposed to make PCR assay in a rapid, portable, and low-cost strategy. This novel platform can perform 6-sample detection per run using multiple fluorescent channels and complete an ultrafast COVID-19 RT-PCR test within 40 min. Here, we evaluated the performance of the microdevice using the gradient-diluted COVID-19 reference samples and commercial PCR kit and determined its limit-of-detection (LoD) as 500 copies/mL, whose variation coefficients for the nucleocapsid (N) gene and open reading frame 1 ab region (ORF1ab) gene are 1.427% and 0.7872%, respectively. The system also revealed an excellent linear correlation between cycle threshold (Ct) values and dilution factors (R2 > 0.99). Additionally, we successfully detected the target RNAs and internal gene in the clinical samples by fast PCR, which shows strong consistency with conventional PCR protocol. Hence, with compact dimension, user-friendly design, and fast processing time, SWM-02 has the capability of offering timely and sensitive on-site molecular diagnosis for prevention and control of pathogen transmission.
PubMed: 36290516
DOI: 10.3390/bioengineering9100548 -
International Journal of Clinical and... 2017Breast cancer has become the most popular malignant tumors in females. Breast cancer stem cells (BCSCs) play an important role in metastasis and recurrence. Previous...
Breast cancer has become the most popular malignant tumors in females. Breast cancer stem cells (BCSCs) play an important role in metastasis and recurrence. Previous study showed close correlation between miR-200c and behavioral regulation of breast cancer stem cells. This study aimed to investigate differential expression of miR-200c in breast cancer stem cells, and its role in regulation tumor formation property. DNA microchip assay and qRT-PCR analyzed differential expression of microRNA between BCSCs and non-tumor formation NTG cells. Bioinformatics and luciferase reporter gene assay determined targeted site of miR-200c. MiR mimic and inhibitor were transfected to change miR-200c expression level, followed by Western Blot for detecting BMI1 gene expression. Cell clonal assay determined cell proliferation, whilst tumor xenograft was performed to analyze tumor formation potency. MiR-200c was down-regulated in BCSCs compared to NTG cells (P<0.05). Bioinformatics and luciferase reporter gene assay attributed BMI1 gene as targeting site of miR-200c. Transfection of miR-200c and inhibitor altered miR-200c expression. Results showed that miR-200c could suppress BMI1 expression, and suppressed proliferation and tumor formation rate (P<0.05). Compared to NTG cells, BCSCs has significantly down-regulated expression of miR-200c. BCSCs facilitate BMI1 gene expression via inhibiting miR-200c expression, further elevating BCSCs proliferation and tumor formation potency.
PubMed: 31966899
DOI: No ID Found -
Sensors (Basel, Switzerland) Jul 2022The Industrial Internet of Things (IIoT) paradigm represents a significant leap forward for sensor networks, potentially enabling wide-area and innovative measurement...
The Industrial Internet of Things (IIoT) paradigm represents a significant leap forward for sensor networks, potentially enabling wide-area and innovative measurement systems. In this scenario, smart sensors might be equipped with novel low-power and long range communication technologies to realize a so-called low-power wide-area network (LPWAN). One of the most popular representative cases is the LoRaWAN (Long Range WAN) network, where nodes are based on the widespread LoRa physical layer, generally optimized to minimize energy consumption, while guaranteeing long-range coverage and low-cost deployment. Additive manufacturing is a further pillar of the IIoT paradigm, and advanced measurement capabilities may be required to monitor significant parameters during the production of artifacts, as well as to evaluate environmental indicators in the deployment site. To this end, this study addresses some specific LoRa-based smart sensors embedded within artifacts during the early stage of the production phase, as well as their behavior once they have been deployed in the final location. An experimental evaluation was carried out considering two different LoRa end-nodes, namely, the Microchip RN2483 LoRa Mote and the Tinovi PM-IO-5-SM LoRaWAN IO Module. The final goal of this research was to assess the effectiveness of the LoRa-based sensor network design, both in terms of suitability for the aforementioned application and, specifically, in terms of energy consumption and long-range operation capabilities. Energy optimization, battery life prediction, and connectivity range evaluation are key aspects in this application context, since, once the sensors are embedded into artifacts, they will no longer be accessible.
Topics: Artifacts; Electric Power Supplies; Monitoring, Physiologic
PubMed: 35897970
DOI: 10.3390/s22155466