Microfluidic Particle Engineering of Hydrophobic Drug with Eudragit E100─Bridging the Amorphous and Crystalline Gap.

Co-processing active pharmaceutical ingredients (APIs) with excipients is a promising particle engineering technique to improve the API physical properties, which can lead to more robust downstream drug product manufacturing and improved drug product attributes. Excipients provide control over critical API attributes like particle size and solid-state outcomes. Eudragit E100 is a widely used polymeric excipient to modulate drug release. Being cationic, it is primarily employed as a precipitation inhibitor to stabilize amorphous solid dispersions. In this work, we demonstrate how co-processing of E100 with naproxen (NPX) (a model hydrophobic API) into monodisperse emulsions via droplet microfluidics followed by solidification via solvent evaporation allows the facile fabrication of compact, monodisperse, and spherical particles with an expanded range of solid-state outcomes spanning from amorphous to crystalline forms. Low E100 concentrations (≤26% w/w) yield crystalline microparticles with a stable NPX polymorph distributed uniformly across the matrix at a high drug loading (∼89% w/w). Structurally, E100 incorporation reduces the size of primary particles comprising the co-processed microparticles in comparison to neat API microparticles made using the same technique and the as-received API powder. This reduction in primary particle size translates into an increased internal porosity of the co-processed microparticles, with specific surface area and pore volume ∼9 times higher than the neat API microparticles. These E100-enabled structural modifications result in faster drug release in acidic media compared to neat API microparticles. Additionally, E100-NPX microparticles have a significantly improved flowability compared to neat API microparticles and as-received API powder. Overall, this study demonstrates a facile microfluidics-based co-processing method that broadly expands the range of solid-state outcomes obtainable with E100 as an excipient, with multiscale control over the key attributes and performance of hydrophobic API-laden microparticles.

Fluorescent microbeads for point-of-care testing: a review.

Microbead-based point-of-care testing (POCT) has demonstrated great promise in translating detection modalities from bench-side to bed-side. This is due to the ease of visualization, high surface area-to-volume ratio of beads for efficient target binding, and efficient encoding capability for simultaneous detection of multiple analytes. This review (with 112 references) summarizes the progress made in the field of fluorescent microbead-based POCT. Following an introduction into the field, a first large section sums up techniques and materials for preparing microbeads, typically of dye-labelled particles, various kinds of quantum dots and upconversion materials. Further subsections cover the encapsulation of nanoparticles into microbeads, decoration of nanoparticles on microbeads, and in situ embedding of nanoparticles during microbead synthesis. A next large section summarizes microbead-based fluorometric POCT, with subsections on detection of nucleic acids, proteins, circulating tumor cells and bacteria. A further section covers emerging POCT based on the use of smartphones or flexible microchips. The last section gives conclusions and an outlook on current challenges and possible solutions. Aside from giving an overview on the state of the art, we expect this article to boost the further development of POCT technology. Graphical Abstract Schematic presentation of the fabrication of microbeads, the detection targets of interest including bacteria, circulating tumor cells (CTCs), protein and nucleic acid, and the emerging point-of-care testing (POCT) platform. The colored wheels of the bus represent the fluorescent materials embedded in (red color) or decorated on the surface of microbeads (green color).

White-light emissive upconversion nanoparticles for visual and colorimetric determination of the pesticide thiram.

The authors describe the use of white-light emitting upconversion nanoparticles (WL-UCNPs) for visual detection of the pesticide thiram. The method is demonstrated to undergo a better discernable color change upon target binding. The WL-UCNPs are modified with the lead(II)-dithizone complex which acts as the energy acceptor and recognition unit. This leads to quenching of the blue (475 nm) and green (545 nm) emissions of the WL-UCNPs, while the red emission (650 nm) remains unaffected. Upon addition of thiram, the quenched emissions are recovered, with a linear signal increase in the range from 2 nM to 20 nM of thiram and a limit of detection of 0.26 nM. The nanoprobe was further integrated into a test paper for visual detection. The concentration-dependent color change that varies from red to cyan and bluish violet and then to white can be visually distinguished. Graphical abstract Schematic presentation of a white-light emissive upconversion nanoparticle based test paper for color-discernable detection of the pesticide thiram. The test stripe exhibits a concentration-dependent color variation spanning from red, cyan, to bluish violet, and at last to white.

Versatile design and synthesis of nano-barcodes.

Encoded nano-structures/particles have been used for barcoding and are in great demand for the simultaneous analysis of multiple targets. Due to their nanoscale dimension(s), nano-barcodes have been implemented favourably for bioimaging, in addition to their security and multiplex bioassay application. In designing nano-barcodes for a specific application, encoding techniques, synthesis strategies, and decoding techniques need to be considered. The encoding techniques to generate unique multiple codes for nano-barcodes are based on certain encoding elements including optical (fluorescent and non-fluorescent), graphical, magnetic, and phase change properties of nanoparticles or their different shapes and sizes. These encoding elements can generally be embedded inside, decorated on the surface of nanostructures or self-assembled to prepare the nano-barcodes. The decoding techniques for each encoding technique are different and need to be suitable for the desired applications. This review will provide a thorough discussion on designing nano-barcodes, focusing on the encoding techniques, synthesis methods, and decoding for applications including bio-detection, imaging, and anti-counterfeiting. Additionally, associated challenges in the field and potential solutions will also be discussed. We believe that a comprehensive understanding on this topic could significantly contribute towards the advancement of nano-barcodes for a broad spectrum of applications.

Family Adoption Program for Undergraduate Medical Students at a New Medical School of Jharkhand: An Experience and SWOC Analysis.

Introduction: Family adoption program (FAP) incorporated into the undergraduate medical education curriculum is beneficial to all stakeholders involved. Many medical colleges have started FAP at different times and various levels based on resources availability, feasibility, and accessibility. This article is intended to cover the process of FAP implementation, the strength, weakness, opportunities, and challenges at various levels, and its scope in future. Methodology: FAP was launched by adopting a hamlet 17 km away from the college. During the foundation course, orientation lessons and logbook discussions were conducted online before the actual field visit. During the initial visit, families were assigned, which was followed by collecting sociodemographic information, a plantation drive, and organizing medical camp/ door to door screening in the last visits for phase one students. Observations: The strengths perceived were early community exposure of students and leadership skills, and the weaknesses were allocating adequate number of slots in the curriculum, adopting families far away, etc., Similarly, FAP has an opportunity to achieve the larger goal of Heath for All in terms of identifying, following up, and managing various socio clinical cases in the adopted families. However, few challenges can pose as it progresses across other phases, such as language problem, allotment of problem families, existing social pathology in family, cultural taboos, etc. Conclusion: The article suggests that once a student leaves, another student should continue the cycle of adoption and provide continuum care of services to prevent the family from being orphaned.

Development and Validation of a Questionnaire to Measure a Medical Student's Interest in the Subject of Community Medicine.

Background: Lack of interest has been cited by many studies as the predominant cause for students undervaluing the subject of Community Medicine. However, there are few valid and reliable tools that could measure this interest. To develop and validate a questionnaire to measure a medical student's interest in the subject of Community Medicine. Material and Methods: Cross-sectional study conducted at MTMC Jamshedpur. The Community Medicine Interest Questionnaire (CMIQ) was developed in two phases: item generation and item reduction. Items were generated through a review of the literature, focused group discussions, and in-depth interviews. In the item reduction phase, the content and construct validity of the questionnaire were ascertained. Content validity was carried out by a group of experts based on three parameters: the interrater agreement on the representativeness of the item, the interrater agreement on the clarity of the items, and the content validity index. The construct validity was ascertained through pilot testing of 480 responses from undergraduate medical students. Exploratory factor analysis through principal axis factoring and Promax rotation. Results: Twenty-five items were generated. Three of these items were removed following expert validation. Furthermore, three items were removed after pilot testing. The resulting CMIQ consisted of 19 items distributed over three dimensions: feeling, value, and predisposition to reengage toward the subject. The internal consistency of each of the subscales was ascertained. Conclusions: CMIQ is a valid and reliable tool that can be used to measure such interest for providing educational interventions.

Medical and social implications of alcohol use among adult women in a rural area of Ranchi, Jharkhand: A cross-sectional study.

Introduction: The harmful use of alcohol is increasing at a huge pace leading to the occurrence of multiple diseases and has become a leading risk factor for global burden of diseases. Aims and Objectives: The aim of this study is to assess the health profile of adult women and to find out the medical and social effects of alcohol consumption. Methodology: A cross-sectional study was conducted in the rural field practice area, Ormanjhi of RIMS, Ranchi, for a duration of 27 months (September 2016 to November 2018) among 336 women by multistage random sampling. A pretested semi-structured questionnaire was used for data collection. Templates were generated in MS Excel sheet and analysis of data was done using SPSS software (20.0). Results: The mean BMI of the study subjects was 21.62 ± 3.33 kg/m2. Anaemia was present in 42.6% of the women, 10.4% women were hypertensive and 9.2% were suffering from diabetes. The association between alcohol consumption and occurrence of co-morbidities was found insignificant. The social effects of alcoholism varied ranging from going into debts seen in 35.42% of the women; 62.5% of the women were criticised about their drinking habit by relatives or children. About 9.5% of the women were found to consume alcohol during their last pregnancy, and among women who were on regular intake of alcohol even during pregnancy, majority (65.62%) of them delivered by normal vaginal delivery. Conclusion: Alcohol consumption among females caused several adverse social consequences without any significant effect on health.

Towards translational optogenetics.

Optogenetics is widely used to interrogate the neural circuits underlying disease and has most recently been harnessed for therapeutic applications. The optogenetic toolkit consists of light-responsive proteins that modulate specific cellular functions, vectors for the delivery of the transgenes that encode the light-responsive proteins to targeted cellular populations, and devices for the delivery of light of suitable wavelengths at effective fluence rates. A refined toolkit with a focus towards translational uses would include efficient and safer viral and non-viral gene-delivery vectors, increasingly red-shifted photoresponsive proteins, nanomaterials that efficiently transduce near-infrared light deep into tissue, and wireless implantable light-delivery devices that allow for spatiotemporally precise interventions at clinically relevant tissue depths. In this Review, we examine the current optogenetics toolkit and the most notable preclinical and translational uses of optogenetics, and discuss future methodological and translational developments and bottlenecks.

Modularly Assembled Upconversion Nanoparticles for Orthogonally Controlled Cell Imaging and Drug Delivery.

Upconversion nanoparticles (UCNPs) have been used effectively as light transducers to convert near-infrared irradiation to short-wavelength emissions for photoactivation in deep tissues. UCNPs with single/multiple emissions under excitation at a single wavelength can be used for simultaneous activation of single or multiple photosensitive molecules only; an ideal multifunctional UCNP nanoplatform should not only have the ability to load multiple molecules but also should activate them at the right time with the right dose when necessary, depending upon the application for which it is used. The control of many biological processes requires complex (simultaneous or subsequent) photoactivation at different time points. Subsequent photoactivation requires UCNPs with orthogonal fluorescence emissions, which can be controlled independently. So far, there are only a few reports about UCNPs with orthogonal emissions. Synthesis of these orthogonal emission nanoparticles is complicated and tedious because nanoparticles with multiple shells need to be synthesized, and different lanthanide ions need to be doped into different shells. Also, there is no flexibility for changing the doped ions and emission profile after the nanoparticles are produced. Here, we have demonstrated a versatile method to modularly assemble individual UCNPs into UCNP clusters (UCNPs-C) with adjustable emissions. The synthesis is much easier, and there is a lot of flexibility in changing the particle size, shape, doped ions, and emission profile. We have demonstrated the use of such UCNPs-C for color encoding at the nanoscale. We further designed orthogonal photoactivatable UCNPs-C (OP-UCNPs-C), which can be independently activated under 980 nm excitation for red emission and 808 nm excitation for UV/blue emission. These OP-UCNPs-C were used for independent activation of processes for cell imaging (980 nm) and drug delivery (808 nm). In comparison to the traditional nonprogrammed activation, a programmed controlled imaging and drug delivery process could guarantee highly targeted and enhanced cell death of cancerous cells.

Microfluidic-Based Immunomodulation of Immune Cells Using Upconversion Nanoparticles in Simulated Blood Vessel-Tumor System.

The goal of cancer immunotherapy is the selective killing of malignant cells by the cooperated efforts of immune cells at the primary and secondary sites. Here, we developed folic acid and secondary lymphoid tissue chemokine-loaded mesoporous silica-modified upconversion nanoparticle construct as a targeting, delivery, and imaging system to attract immune cells to folate receptor-expressing tumor cells. The effectiveness of the nanoparticles in targeting dendritic cells and T cells to the tumor compartment was tested in a vasculature-tumor interface model constructed from the co-culture of endothelial cells and ovarian cancer cells, in different interconnected channels in a microfluidic device. In comparison to the unconjugated nanoparticles, the folic acid-conjugated nanoparticles efficiently diffuse across the engineered blood vessel and specifically target the folate receptor-expressing ovarian cancer cells. The developed microfluidic platform was further used to demonstrate increased dendritic cell and T cell migration toward the ovarian cancer cell channel induced by the presence of the chemokine- and folic acid-loaded nanoparticles. The nanoparticle construct did not exhibit any significant cyto- and hemotoxicity. This proof of concept showed the potential of the nanoparticles to target cancer cells as well as to recruit dendritic cells and T cells to tumor sites to augment the weak host immune response.

Upconversion superballs for programmable photoactivation of therapeutics.

Upconversion nanoparticles (UCNPs) are the preferred choice for deep-tissue photoactivation, owing to their unique capability of converting deep tissue-penetrating near-infrared light to UV/visible light for photoactivation. Programmed photoactivation of multiple molecules is critical for controlling many biological processes. However, syntheses of such UCNPs require epitaxial growth of multiple shells on the core nanocrystals and are highly complex/time-consuming. To overcome this bottleneck, we have modularly assembled two distinct UCNPs which can individually be excited by 980/808 nm light, but not both. These orthogonal photoactivable UCNPs superballs are used for programmed photoactivation of multiple therapeutic processes for enhanced efficacy. These include sequential activation of endosomal escape through photochemical-internalization for enhanced cellular uptake, followed by photocontrolled gene knockdown of superoxide dismutase-1 to increase sensitivity to reactive oxygen species and finally, photodynamic therapy under these favorable conditions. Such programmed activation translated to significantly higher therapeutic efficacy in vitro and in vivo in comparison to conventional, non-programmed activation.

Upconversion Nanoparticles-Encoded Hydrogel Microbeads-Based Multiplexed Protein Detection.

Fluorescently encoded microbeads are in demand for multiplexed applications in different fields. Compared to organic dye-based commercially available Luminex's xMAP technology, upconversion nanoparticles (UCNPs) are better alternatives due to their large anti-Stokes shift, photostability, nil background, and single wavelength excitation. Here, we developed a new multiplexed detection system using UCNPs for encoding poly(ethylene glycol) diacrylate (PEGDA) microbeads as well as for labeling reporter antibody. However, to prepare UCNPs-encoded microbeads, currently used swelling-based encapsulation leads to non-uniformity, which is undesirable for fluorescence-based multiplexing. Hence, we utilized droplet microfluidics to obtain encoded microbeads of uniform size, shape, and UCNPs distribution inside. Additionally, PEGDA microbeads lack functionality for probe antibodies conjugation on their surface. Methods to functionalize the surface of PEGDA microbeads (acrylic acid incorporation, polydopamine coating) reported thus far quench the fluorescence of UCNPs. Here, PEGDA microbeads surface was coated with silica followed by carboxyl modification without compromising the fluorescence intensity of UCNPs. In this study, droplet microfluidics-assisted UCNPs-encoded microbeads of uniform shape, size, and fluorescence were prepared. Multiple color codes were generated by mixing UCNPs emitting red and green colors at different ratios prior to encapsulation. UCNPs emitting blue color were used to label the reporter antibody. Probe antibodies were covalently immobilized on red UCNPs-encoded microbeads for specific capture of human serum albumin (HSA) as a model protein. The system was also demonstrated for multiplexed detection of both human C-reactive protein (hCRP) and HSA protein by immobilizing anti-hCRP antibodies on green UCNPs.

Elimination of concentration dependent luminescence quenching in surface protected upconversion nanoparticles.

Quenching of lanthanide-doped upconversion nanoparticle (UCNP) luminescence at high dopant concentrations is an existing challenge that hampers their desired applications. It has already been reported that concentration quenching is strongly coupled to surface quenching. However, in this study we found that surface quenching is not the only cause for concentration quenching and concentration quenching was still observed in UCNPs with a well-protected surface. By using a mathematical model to better understand the processes, we proposed that this concentration quenching could be minimized by moving the extra sensitizers (Yb3+) to a different layer. To achieve this, a new tri-layer UCNP structure with sensitizers isolated in the middle layer was developed. It was observed that the quenching was reduced, and the luminescence intensity was enhanced up to 11.8 times in comparison with the brightest UCNPs without the sensitizing layer.

Fluorescent label-free quantitative detection of nano-sized bioparticles using a pillar array.

Disease diagnostics requires detection and quantification of nano-sized bioparticles including DNA, proteins, viruses, and exosomes. Here, a fluorescent label-free method for sensitive detection of bioparticles is explored using a pillar array with micrometer-sized features in a deterministic lateral displacement (DLD) device. The method relies on measuring changes in size and/or electrostatic charges of 1 µm polymer beads due to the capture of target bioparticles on the surface. These changes can be sensitively detected through the lateral displacement of the beads in the DLD array, wherein the lateral shifts in the output translates to a quantitative measurement of bioparticles bound to the bead. The detection of albumin protein and nano-sized polymer vesicles with a concentration as low as 10 ng mL-1 (150 pM) and 3.75 µg mL-1, respectively, is demonstrated. This label-free method holds potential for point-of-care diagnostics, as it is low-cost, fast, sensitive, and only requires a standard laboratory microscope for detection.

A protected excitation-energy reservoir for efficient upconversion luminescence.

Lanthanide-doped upconversion nanoparticles (UCNPs) are of great interest for biomedical applications. Currently, the applicability of UCNP bionanotechnology is hampered by the generally low luminescence intensity of UCNPs and inefficient energy transfer from UCNPs to surface-bound chromophores used e.g. for photodynamic therapy or analyte sensing. In this work, we address the low-efficiency issue by developing versatile core-shell nanostructures, where high-concentration sensitizers and activators are confined in the core and shell region of representative hexagonal NaYF4:Yb,Er UCNPs. After doping concentration optimization, the sensitizer-rich core is able to harvest/accumulate more excitation energy and generate almost one order of magnitude higher luminescence intensity than conventional homogeneously doped nanostructures. At the same time, the activator ions located in the shell enable a ∼6 times more efficient resonant energy transfer from UCNPs to surface-bound acceptor dye molecules due to the short distance between donor-acceptor pairs. Our work provides new insights into the rational design of UCNPs and will greatly increase the general applicability of upconversion nanotechnologies.