Optical tweezers
4-May-2023: New way to track particles in soft colloids using optical tweezers can be applied in targeted drug delivery
Scientists have found a way to track minute clay particle movements within soft clay colloids using optical tweezers -- the application of which in biological systems brought the Nobel Prize in Physics in 2018. This new way to track particles and manipulate them as desired can be applied in areas like targeted drug delivery.
Using optical tweezers, researchers at Raman Research Institute (RRI), an autonomous institute funded by the Department of Science and Technology, Govt. of India, attempted to study the dynamics and hidden structural details of Laponite, a synthetic clay. As these clay particles are the same size (monodisperse) and transparent, so they are best suitable for performing advanced studies under light. Laponite is a widely used raw material in the pharmaceutical and cosmetics industries. This clay comprises disk-shaped particles sized 25 to 30 nanometres (nm) and one nm in thickness.
Polystyrene beads dispersed in Laponite clay suspension were used for the experimental setup. With time, microstructures were noted to have developed due to the electrostatic interactions between the clay particles. These microstructures grew stronger with time, with their network size dependent on the concentration of Laponite particles.
“These structures are responsible for the material's elasticity, enabling adjustment of elasticity by tuning the microstructures. These microstructures also form connections with micron-sized polystyrene particles, which are used to probe these suspensions in such studies,” said Anson G. Thambi, a third-year Ph.D. student at RRI.
In a study published in the journal ‘Soft Matter, Ranjini Bandyopadhyay, faculty, RRI, and her team used optical tweezers as they wanted to measure movements of the probe in nanometres scales, where the properties of the medium evolve with passing time. Optical tweezer is a popular tool in an optics laboratory, used to measure minute forces and manipulate tiny dielectric beads trapped at the tight focus of an intense laser beam over length scales down to a few nanometers. It allows the inducement of movement in the trapped probe particle, and its response is analysed to extract previously inaccessible local viscoelastic properties of the underlying medium.
“These attachments between the probe (PS) and Laponite clay particles are necessary to understand the properties of the suspension if the internal networks are of sizes greater than the probe itself,” said Bandyopadhyay.
Furthermore, the team used cryogenic field emission scanning electron microscopy (cryo-FESEM) to examine the average pore areas formed by the Laponite microstructures.
“Interestingly, the collective observations obtained using an optical tweezer and cryo-FESEM experiments revealed an intriguing and previously unknown correlation. We found that beads trapped by the optical tweezer moved much slower in denser network structures,” added Bandyopadhyay.
The RRI team thus concluded the prevalence of a direct relation between the morphologies of the clay suspension structures and the probe particle dynamics at micrometre length scales.
Tele Mental Health Assistance and Networking Across States (Tele-MANAS)
24-Apr-2023: India crosses a significant milestone for The National Tele Mental Health Programme of India
In a significant achievement towards providing quality mental healthcare for all across the country, Tele Mental Health Assistance and Networking Across States (Tele-MANAS) helpline of the Union Ministry of Health & Family Welfare has reached a milestone by receiving over 100,000 calls since its launch in October 2022.
The National Tele Mental Health Programme of India was inaugurated on the occasion of the World Mental Health Day on 10th October 2022. Since its inception, the service has aimed to create a digital mental health ecosystem that has provided a boost to the existing mental healthcare services. An urgent need was felt for a digital mental health network in the wake of COVID and Tele-MANAS aimed to provide the same by giving access to the mental healthcare services 24X7 to even in the remotest part of the country. These services are available for all individuals free-of-cost through a toll-free number 14416 / 1800-89-14416.
The nation-wide service, an initiative of the Ministry of Health and Family Welfare, Government of India successfully completed its first 6 months of functioning, with currently over 38 functional Tele MANAS Cells spread across 27 States and UTs, providing mental health services in over 20 languages and over 1600 trained counsellors running the first-line services. Most of the calls received at Tele MANAS thus far, are from callers calling regarding sadness of mood, stress related calls, exam related anxiety, domestic disturbances and calls regarding sleep disturbances.
Tele MANAS initiative which was announced by Union Ministry of Health & Family Welfare in the Union budget 2022-23 as an acknowledgement to the mental health crisis in the country, is a novel initiative to enable people to seek support for their mental health issues while maintaining anonymity of the callers, thereby reducing the stigma generally surrounding mental health issues.
The National Tele Mental Health Programme of India focusses on building the mental health workforce of the nation through capacity building initiatives whilst simultaneously ensuring that mental health services can reach free of cost to every household and every individual, targeting the most vulnerable and unreached sections of society that may otherwise have gone unnoticed. With Tele MANAS reaching the 1 lakh mark in 6 months, it turns a new leaf in achieving its ultimate aim of building a robust digital mental health network throughout India.
Lateral Flow Immunoassay (LFIA)
5-Apr-2023: New method of visual detection of SARS-CoV-2 can identify the infection at early stage
A new sandwich based lateral flow immunoassay (LFIA) for the detection of Receptor Binding Domain (RBD) of severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2) could provide an efficient substitute for RT-PCR tests. It can detect that RBD antigen of the SARS-CoV-2 at an early stage of infection with a visual line of detection (LOD).
Popularly used gold standard techniques such as RT-PCR and ELISA are usually time-consuming, require skilled labor, specific equipment and are not feasible for on-site detection.
In order to overcome this challenge, a team of researchers from DBT-National Institute of Animal Biotechnology (NIAB) and Gandhi Medical College developed a rapid and robust platform for early and on-field detection of SARS-CoV-2 virus. A smartphone app (Color grab) has been used for the qualitative analysis of the test strip. The developed LFIA working on the principle of antigen-antibody interaction holds the potential to be used for detection of SARS-CoV-2 without any requirement of skilled personnel and subsequently reduce the spread of the virus.
With support from Science and Engineering Research Board (SERB), an institution of the Department of Science and Technology (DST) the scientists came together to clone the gene responsible for RBD protein expression, and purify it to generate the antibody(Ab). The generated antibodies were then conjugated with monodisperse gold nanoparticles (AuNPs) to be used as a capture probe for colorimetric detection. The fabricated LFIA works in a sandwich format, where the RBD target analyte in the sample interacts with the gold nanoparticle conjugated RBD antibody to form a complex (AuNPs-Ab), which further moves along the nitrocellulose membrane and reacts with the RBD antibody coated as test line on the membrane to form a red colour band.
The RBD Ab and IgG secondary Ab were coated on the nitrocellulose membrane as test and control, respectively to test the presence of antigen (Ag) in the sample. Further, the excess antibody bonded with the control line coated with secondary IgG antibody validating the functionality of the test strip. An absorbent pad was placed at the end of the strip to prevent backflow across the strip.
The presence of band colour at test and control line indicates a positive result whereas a single line in control indicates a negative result. Depending on the target analyte, various parameters such as blocking buffer, antibody conjugation concentration, and antibody coating concentration on the membrane have been optimized to obtain band color with maximum binding efficiency. The band intensity of the test line was analysed using a simple smartphone-based application for image acquisition and analysis of the test line color, which can split any color data into its three primary color components -- red, green, and blue (RGB data). The specific color component shows the trend of increasing or decreasing intensity of color. This study was published in the Journal of Medical Virology recently.
The developed LFIA strips can be useful as a portable, point of care device (PoC) for on-site detection of SARS-CoV-2 particularly at home or even in rural areas. Moreover, the cost of LFIA strips is much less as compared to standard RT-PCR test making it a more economical option for people who cannot afford the RT-PCR test.