ABSTRACT
The latest addition to the family of Coronaviruses, SARS-CoV-2, unleashed its wrath across the globe. The outbreak has been so rapid and widespread that even the most developed countries are still struggling with ways to contain the spread of the virus. The virus began spreading from Wuhan in China in December 2019 and has currently affected more than200 countries worldwide. Nanotechnology has huge potential for killing viruses as severe as HIV, herpes, human papilloma virus, and viruses of the respiratory tract, both inside as well as outside the host. Metal-nanoparticles can be employed for biosensing methodology of viruses/bacteria, along with the development of novel drugs and vaccines for COVID-19 and future pandemics. It is thus required for the nanoparticles to be synthesized quickly along with precise control over their size distribution. In this study, we propose a simple microfluidic-reactor-platform for in-situ metal-nanoparticle synthesis to be used against the pandemic for the development of preventive, diagnostic, and antiviral drug therapies. The device has been fabricated using a customized standard photolithography process using a simple and cost-effective setup. The confirmation on standard silver and gold metal nanoparticle formation in the microfluidic reactor platform was analysed using optical fiber spectrophotometer. This novel microfluidic platform provides the advantage of in-situ synthesis, flow parameter control and reduced agglomeration of nanoparticles over the bulk synthesis due to segregation of nucleation and growth stages inside a microchannel. The results are highly reproducible and hence scaling up of the nanoparticle production is possible without involving complex instrumentation.
ABSTRACT
In recent decades, organ-on-chip devices have gained substantial interest as an alternative for studying the pathophysiological processes relevant to drug screening. Micropumps are being utilized to simulate the in vivo physiological fluid flow more realistically in these organ-on-chip devices. Micropumps play a crucial role in pumping, perfusion, and circulation of fluids in various microdevices such as on-chip PCR, DNA microarrays, miniature bioreactor cell separation, and lab-on-chip biosensing platforms. With the rapid growth in technology, efficient pumping for proper circulation of media and nutrients has become imperative. In this study, we have described the design and development of an open-source impedance micropump for continuous perfusion of nutrient medium in a liver-on-chip prototype. This micropump is controlled via an integrated microcontroller board, with an observed flow rate ranging from 0.2 to 2 mL/min. Google Sketchup 2020 and DLP 3D printing were used to fabricate small precise parts of the impedance micropump. The flow rate was measured to characterize the actuating performance of the micropump. The poly-dimethyl siloxane-based liver-on-chip prototype has been fabricated using a soft photolithography procedure. Further, a study of continuous perfusion of culture medium through the liver-on-chip containing the Hepg2 cell line was successfully performed by integrating it with the impedance micropump. Hoechst staining and Alamar Blue observed cell viability to confirm the healthy cell growth inside the liver-on-chip microfluidic chip. The compactness of the overall setup allows it to fit in a Petri plate, eliminating chances of contamination while cell handling.
ABSTRACT
The requirement for clean water has been increasing for several reasons, for instance, the fast industrialization of developing countries, climate change, environmental pollution, growth of biofuel use and the resulting growth in irrigation. To meet the requirements for contamination-free water, a cost-effective water treatment can substantially improve the developing world's health, largely for children, and there is predicted to be a huge market for this. Existing water treatment processes consist of various phases that are time-consuming as well as pricey. There is an essential demand for cost-effective point of use methods to purify drinking water to reduce the impact of diseases induced by numerous waterborne pathogens. The development of micro-devices, with different outcomes, can be a helpful solution to various problems. To make this reality, a novel microfluidic device for the purification of water, with multiple hydrodynamic effects, has been shown in this paper. In the proposed novel device, the network of interconnected microfluidic channels was created in such a way that an amalgamation of multiple effects, such as the Fåhræus effect, centrifugal force, the Zweifach-Fung effect and constriction followed by expansion, act together in the microchannel to separate suspended impurities (i.e. bacteria and similar length scale particles present in water in the suspension form) from water. Furthermore, to improve the bacterial separation efficiency of the device, the pure water channel of the microdevice was designed with an encircled triple-sided film valve arrangement at a few points, which aided the modulation of the cross-sectional area of the pure water channel. Consecutively, the reduction of the cross-sectional area of the pure water channel caused a highly effective Zweifach-Fung effect, which aided the better separation of the suspended particles (i.e. bacteria, dust particles etc.). The device was observed to have an average of 99.6% efficiency in the separation of suspended microparticles/microbes with dimensions in the range of 1-10 micrometres. The device performance indicated its potential for the separation of other similar suspended impurities, i.e. small dust particles, bacteria, fungi, viruses and similar particles present in water in the suspension form.
ABSTRACT
A novel microfluidic-device for water disinfection via diverse physiochemical effects has been demonstrated. Firstly, a microfluidic device with embedded, multiple germicidal UV-LEDs was fabricated through the innovatively modified cost-effective soft-lithography process. Further, synthesised silver nanoparticles were immobilized within its inner microchannel surface. Disinfection results proved the synergistic bactericidal effect of coated AgNPs and coupled UV-light, while a suspension of bacterial strains, were passed through the micro-device.
