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 Biomedical MicrodevicesJournal Prestige (SJR): 0.538 Citation Impact (citeScore): 2Number of Followers: 9      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1572-8781 - ISSN (Online) 1387-2176 Published by Springer-Verlag  [2658 journals]
• Dynamic flow and shear stress as key parameters for intestinal cells
morphology and polarization in an organ-on-a-chip model

Abstract: Abstract Gut-on-a-chip microfluidic devices have emerged as versatile and practical systems for modeling the human intestine in vitro. Cells cultured under microfluidic conditions experience the effect of shear stress, used as a biomechanical cue to promote a faster cell polarization in Caco-2 cells when compared with static culture conditions. However, published systems to date have utilized a constant flow rate that fails to account for changes in cell shear stress ( $${\tau }_{c}$$ ) resulting from changes in cell elongation that occur with differentiation. In this study, computational fluid dynamics (CFD) simulations predict that cells with villi-like morphology experience a $${\tau }_{c}$$ higher than bulge-like cells at the initial growth stages. Therefore, we investigated the use of a dynamic flow rate to maintain a constant $${\tau }_{c}$$ across the experiment. Microscopic assessment of cell morphology and dome formation confirmed the initiation of Caco-2 polarization within three days. Next, adopting our dynamic approach, we evaluated whether the following decreased flow could still contribute to complete cell differentiation if compared with the standard constant flow methodology. Caco-2 cells polarized under both conditions, secreted mucin-2 and villin and formed tight junctions and crypt-villi structures. Gene expression was not impacted using the dynamic flow rate. In conclusion, our dynamic flow approach still facilitates cell differentiation while enabling a reduced consumption of reagents.
PubDate: 2021-10-16

• Axial forces at disk surfaces in a cylindrical nanopore

Abstract: Abstract Understanding the physics of object translocation in nanopores is critical for using nanopores as sensors of molecular properties and as object size and shape sensors. Based on Poisson-Nernst-Planck and Navier–Stokes simulations we dissect three axial pressures and forces at disk edges (upper, lower and rim) – Coulomb, dielectric and fluidic. Axial Coulomb and dielectric rim forces are small and cancel each other. Upper and lower axial forces are largely controlled by the external axial electric field and interestingly by the pore wall charges that determine the amplitude and direction of axial combined force. Axial total Coulomb force (sum of its upper and lower edge components) makes the greatest contribution, but the axial total dielectric force (calculated using Maxwell stress tensor), which opposes it is surprisingly large. External ion concentration alters Coulomb and axial dielectric forces but influences only their amplitude. Axial total fluidic force is near zero (its upper and lower disk edge components are significant but cancel each other) regardless of external electric field, but pore wall charges and external fluidic pressure can alter it. Modest changes of external electric field or concentration produce axial forces comparable to those produced by large external fluidic pressures. Axial forces depend little on disk’s axial position. Finally, mean axial pressures (calculated to compare forces acting on disks of different radius) are greater for larger disks.
PubDate: 2021-10-13

• Fabrication and characterization of a microneedle array electrode with
flexible backing for biosignal monitoring

Abstract: Abstract The conventional wet electrode for recording biosignals poses many inconveniences, as it requires an electrolytic gel that dries over time changing its electrical characteristics. The skin typically needs to be abraded when the electrode is applied to record high-quality signals, requiring assistance of trained personnel for the placement of the wet electrode. Alternative electrode designs to overcome these challenges often have difficulties recording small amplitude signals or their fabrication methods are complex and expensive. This research proposes a novel design and a simple fabrication method for a dry microneedle electrode for biosignal monitoring. The electrode can record electroencephalogram and electrocardiogram signals from a human subject without electrolytic gel and it does not require skin preparation such as abrasion, making it suitable for long term measurements as opposed to the wet electrode. When applied to the skin of a human subject with an impact inserter, the electrode has a lower impedance at the skin–electrode interface yielding better signal recording compared to application by hand. The selected electrode materials provides microneedles stiff enough to cross the outmost layer of the skin, while the flexible backing of the electrode has been designed to improve the conformation of the electrode to the rounded shape of the body. The proposed fabrication method for the electrode is based on a simple mold casting process that enables batch production while also reducing the time spent in a cleanroom and the use of expensive machinery.
PubDate: 2021-10-06

• Bioinspired soft microrobots actuated by magnetic field

Abstract: Abstract In contrast to traditional large-scale robots, which require complicated mechanical joints and material rigidity, microrobots made of soft materials have exhibited amazing features and great potential for extensive applications, such as minimally invasive surgery. However, microrobots are faced with energy supply and control issues due to the miniaturization. Magnetic field actuation emerges as an appropriate approach to tackle with these issues. This review summarizes the latest progress of biomimetic soft microrobots actuated by magnetic field. Starting with an overview of the soft material and magnetic material adopted in the magnetic field actuated soft microrobots, the various fabrication methods and design structures of soft microrobots are summarized. Subsequently, practical and potential applications, such as targeted therapy, surgical operation, and the transportation of microscopic objects, in the fields of biomedicine and environmental remediation are presented. In the end, some current challenges, and the future development trends of magnetic soft microrobots are briefly discussed. This review is expected to offer a helpful guidance for the new researchers of biomimetic soft microrobots actuated by magnetic field.
PubDate: 2021-10-01

• A novel design of microfluidic platform for metronomic combinatorial
chemotherapy drug screening based on 3D tumor spheroid model

Abstract: Abstract For treating cancer at various stages, chemotherapy drugs administered in combination provide better treatment results with lower side effects compared to single-drug therapy. However, finding the potential drug combinations has been challenging due to the large numbers of possible combinations from approved drugs and the failure of in vitro 2D well plate-based cancer models. 3D spheroid-based high-throughput microfluidic platforms recapitulate some of the important features of native tumor tissue and offer a promising alternative to evaluate the combinatory effects of the drugs. This study develops a novel polydimethylsiloxane (PDMS) based microfluidic design with a dynamic environment and strategically placed U-shaped wells for testing all seven possible combinations (three single-drug treatments, three pairwise combinations, treatment with all three drugs) of three chemotherapy drugs (Paclitaxel, Vinorelbine, and Etoposide) on lung tumor spheroids. The design of U-shaped wells has been validated with computational results. Firstly, we test all combinations of drugs on the conventional well plate in static conditions with 3D tumor spheroids. Based on static drug testing results, we show a proof-of-concept by testing the most effective drug combination on the microfluidic device in a dynamic environment. The concentration of the drugs used in combination falls below the maximum tolerated dose (MTD) of the individual drugs, towards low dose metronomic (LDM) chemotherapy. LDM combinatorial chemotherapy identified in this study can potentially lower toxicity and provide better treatment results in cancer patients. The device can be further used to culture patient-specific tumor spheroids and identify synergistic drug combinations for personalized medicine.
PubDate: 2021-10-01

• Immunomagnetic separation in a novel cavity-added serpentine microchannel
structure for the selective isolation of lung adenocarcinoma cells

Abstract: Abstract The manipulation and separation of circulating tumor cells (CTCs) in continuous fluidic flows play an essential role in various biomedical applications, particularly the early diagnosis and treatment of diseases. Recent advances in magnetic bead development have provided promising solutions to the challenges encountered in CTC manipulation and isolation. In this study, we proposed a biomicrofluidic platform for specifically isolating human lung carcinoma A549 cells in microfluidic channels. The principle of separation was based on the effect of the magnetic field on aptamer-conjugated magnetic beads, also known as immunomagnetic beads, in a serpentine microchannel with added cavities (SMAC). The magnetic cell separation performance of the proposed structure was modeled and simulated by using COMSOL Multiphysics. The experimental procedures for aptamer molecular conjugation on 1.36 µm-diameter magnetic beads and magnetic bead immobilization on A549 cells were also reported. The lung carcinoma cell–bead complexes were then experimentally separated by an external magnetic field. Separation performance was also confirmed by optical microscopic observations and fluorescence analysis, which showed the high selectivity and efficiency of the proposed system in the isolation and capture of A549 cells in our proposed SMAC. At the flow rate of 5 µL/s, the capture rate of human lung carcinoma cells exceeded 70% in less than 15 min, whereas that of the nontarget cells was approximately 4%. The proposed platform demonstrated its potential for high selectivity, portability, and facile operation, which are suitable considerations for developing point-of-care applications for various biological and clinical purposes.
PubDate: 2021-10-01

• Separation of circulating tumor cells from blood using dielectrophoretic
DLD manipulation

Abstract: Abstract Circulating Tumor Cells (CTCs) play a prominent role in early cancer detection. Emerging label-free techniques can be promising to CTC detection due to advantages in preserving cell integrity and minimal sample consumption. Deterministic Lateral Displacement (DLD) is a size-based label-free technique employing laminar flow for continuous sorting of suspended cells. However, separation based solely on size is challenging as the size distributions of CTCs tend to overlap with blood cells. Moreover, the rarity of CTCs in blood requires high throughput processing of samples for clinical utility. In this work, a dielectrophoretic DLD technique is presented to segregate CTCs from blood. This technique utilizes the cell size and dielectric properties as well as particle movement caused by polarization effect to accomplish continuous separation at high flow rates. A numerical model is developed and validated to investigate the effects of various parameters related to the fluid flow, micro-post array, and electric field. It is demonstrated that the dielectrophoretic DLD with specific post arrangement can continuously separate A549 lung CTCs from WBCs by applying a field frequency close to the crossover frequency of CTCs. The analysis further indicates that such a device can perform well despite uncertainties of CTC crossover frequencies. Additionally, efficient separation with minimum clogging can be achieved by setting the electric field perpendicular to fluid flow. The presented platform offers distinct advantages and can be potentially combined with techniques such as antibody-based immune-binding methods for rapid detection of CTCs.
PubDate: 2021-09-28

• Electrically controlled nicotine delivery through Carbon nanotube
membranes via electrochemical oxidation and nanofluidically enhanced
electroosmotic flow

Abstract: Abstract A promising tool for nicotine addiction treatment is a programmable nicotine delivery device coupled to smart phone-assisted behavioral therapies. Key metrics for such a device are delivery of adjustable nicotine doses tailored to individual needs, compact size and power efficiency. Reported here is a detailed optimization of carbon nanotube (CNT) membrane fabrication based on electrochemical oxidation, to improve its electrically driven performance for nicotine fluxes and switching ON (-1.5 V)-OFF (0 V) flux ratio. ON- state nicotine flux of ~ 6 µmoles/cm2/h at -1.5 V applied bias was achieved allowing ~ 6-folds decrease in the size of device (4 cm2) to attain flux equivalent to high dose nicotine gum (1.1 µmoles/cm2/h). Application of + 1.5 V bias in OFF state reduced diffusional background flux, giving an ON (-1.5 V)/OFF (+ 1.5 V) flux ratio of 68 that enabled device to deliver between the highest nicotine gum (1.1 µmoles/cm2/h) and lowest nicotine patch (0.08 µmoles/cm2/h) doses, as well as taper off nicotine doses for long term addiction treatment. The nicotine transport mechanism was studied as a function of pH and applied bias, using neutral tracer molecule, showing a mechanism of both electroosmosis and electrophoresis in the atomically smooth nanofluidic pores of CNTs. Optimal power consumption/flux efficiency of 111(µW/cm2)/µmoles/cm2/h was achieved allowing watch-battery lifetimes of 7–62 days for conventional treatment dosing regimens. Bluetooth-enabled, remotely controlled CNT membrane system has potential for treatments of nicotine, opioid and alcohol addictions that needs dose adjustment with precise temporal control.
PubDate: 2021-09-25

• CO2 laser fabrication of hydrogel-based open-channel microfluidic devices

Abstract: Abstract This study proposed a rapid and low-cost fabrication method for open-channel hydrogel-based microfluidic devices using CO2 laser ablation. The agarose hydrogel substrate was prepared with agarose gelation in DI water upon microwave heating, then a commercial CO2 laser system was used for the direct laser ablation of microchannels on the surface of agarose hydrogel substrate, the hydrophilic nature of the microchannels fabricated on hydrogel substrate enables the self-driven of the liquid inside the microchannels with capillary force. The profiles of the laser ablated microchannels on agarose hydrogel substrate with various laser power and scan speed were studied in detail. Due to the loss of water when exposed to the atmosphere, significant deformation of the fabricated microchannels was observed, and the profile change was recorded for 48 h for comparison. An easy-to-access storage method of hydrogel-based microfluidic device in DI water was also proposed in this study. Unlike compact silicon or polymer-based microfluidic devices, the hydrogel is formed by cross-linked polymer chains filled with water, for a better understanding of the diffusion of small molecules into the bulk hydrogel material during fluid propagation inside the microchannel, the Nile red fluorescent was added into the liquid and the diffusion across the hydrogel-based microchannels with time was measured and discussed in this study. Several open-channel agarose hydrogel-based microfluidic devices were fabricated in this study for the demonstration of the proposed fabrication method. The CO2 laser ablation approach for agarose hydrogel-based microfluidic devices has the advantages of rapid processing time, low-cost, highly biocompatible, and self-driven without pumps and could have wide application potentials in biological and medical fields.
PubDate: 2021-09-22

• Enhanced aptasensor performance for targeted HER2 breast cancer detection
by using screen-printed electrodes modified with Au nanoparticles

Abstract: Abstract The development of an Aptamer based biosensor for the selective detection of human epidermal growth factor receptor 2 (HER2) with high sensitivity and specificity was achieved. A screen-printed carbon electrode was used in the scope of this work. The HER2 Aptamer was immobilized via electrostatic adsorption on the surface of a screen-printed electrode, which was modified with Au Nanoparticles (~ 20 nm diameter) to support the Aptamer immobilization. The Aptasensor was extensively investigated using Cyclic voltammetry, Differential pulse voltammetry, Electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy and Atomic force microscopy. The Aptasensor exhibits a fast response with a binding time of only 5 min and shows a log-linear response over a wide concentration range of 0.001—100 ng/mL. Moreover, it has high sensitivity and enhanced detection limit reaching 52.85 μA/ng/mL, and 0.001 ng/mL, respectively, with a relative standard deviation < 5%. The Aptasensor selectivity was studied by using different interfering substances, and the results demonstrate that the Aptasensor is efficient for the detection of HER2 with approximately 8% extent of the interference.
PubDate: 2021-09-21
DOI: 10.1007/s10544-021-00586-9

• A portable multi-sensor module for monitoring external ventricular drains

Abstract: Abstract External ventricular drains (EVDs) are used clinically to relieve excess fluid pressure in the brain. However, EVD outflow rate is highly variable and typical clinical flow tracking methods are manual and low resolution. To address this problem, we present an integrated multi-sensor module (IMSM) containing flow, temperature, and electrode/substrate integrity sensors to monitor the flow dynamics of cerebrospinal fluid (CSF) drainage through an EVD. The impedimetric sensors were microfabricated out of biocompatible polymer thin films, enabling seamless integration with the fluid drainage path due to their low profile. A custom measurement circuit enabled automated and portable sensor operation and data collection in the clinic. System performance was verified using real human CSF in a benchtop EVD model. Impedimetric flow sensors tracked flow rate through ambient temperature variation and biomimetic pulsatile flow, reducing error compared with previous work by a factor of 6.6. Detection of sensor breakdown using novel substrate and electrode integrity sensors was verified through soak testing and immersion in bovine serum albumin (BSA). Finally, the IMSM and measurement circuit were tested for 53 days with an RMS error of 61.4 μL/min.
PubDate: 2021-09-20
DOI: 10.1007/s10544-021-00579-8

• Label-free rapid isolation of saccharomyces cerevisiae with optically
induced dielectrophoresis-based automatic micromanipulation

Abstract: Abstract Saccharomyces cerevisiae is well-known in the baking and brewing industries and always used for the preparation of probiotics, especially its subtype, Saccharomyces boulardii, to prevent and treat various diarrhea and intestinal diseases. However, case reports on the side effects of a wide range of serious infections for the elderly, immunocompromised and critically ill patients after treatment with the S. cerevisiae have been increasing in recent years. The existing diagnose methods of the invasive S. cerevisiae infections in clinical, especially, the key step of the method—cell isolation, is time-consuming that always miss timey diagnose and early prevention. Here, we propose a new automatic micromanipulation method to label-free rapid isolation of S. cerevisiae based on the optically-induced dielectrophoresis (ODEP) technology, combining with image processing and recognition. S. cerevisiae is firstly identified by the image recognition method and then, automatically captured and moved to the target location by designing optical patterns. The results indicate the method can flexibly and automatically manipulate multiple S. cerevisiae cells simultaneously, such as, arranging S. cerevisiae cells, moving an array of the cells at any directions, aggregating the cells, and separating S. cerevisiae from the solution mixed with impurities. This work represents a step toward the use of automatic micromanipulation of ODEP technology to automatically and rapidly isolate S. cerevisiae for the detection of the invasive S. cerevisiae infections.
PubDate: 2021-09-18
DOI: 10.1007/s10544-021-00582-z

• Cellulose nanocrystals-based materials as hemostatic agents for wound
dressings: a review

Abstract: Abstract Wound dressings are devices used to stop bleeding and provide appropriate environmental conditions to accelerate wound healing. The effectiveness of wound dressing materials can be crucial to prevent deaths from excessive bleeding in surgeries and promote complete restoration of the injury. Some requirements for an ideal wound dressing are rapid hemostatic effect, high swelling capacity, antibacterial properties, biocompatibility, biodegradability, and mechanical strength. However, finding all these properties in a single material remains a challenge. In this context, nanocomposites have demonstrated an excellent capacity for this application because of their multifunctionality. One of the emerging materials used in nanocomposite manufacture is cellulose nanocrystals (CNCs), which are rod-like crystalline nanometric structures present on cellulose chains. These nanoparticles are attractive for wound healing applications because of their high aspect ratio, high mechanical properties, functionality and low density. Hence, this work aimed to present an overview of nanocomposites constituted by CNCs for wound healing applications. The review focuses on the most common materials used as matrices, the types of dressing, and their fabrication techniques. Novel wound dressings composites have improved hemostatic, swelling, and mechanical properties compared to other pure biopolymers while preserving their other biological properties. Films, nanofibers mats, sponges, and hydrogels have been prepared with CNCs nanocomposites, and in vitro and in vivo tests have proved their suitability for wound healing.
PubDate: 2021-09-07
DOI: 10.1007/s10544-021-00581-0

• Hand-drawn electrode based disposable paper chip for artificial sweat
analysis using impedance spectroscopy

Abstract: Abstract Low cost, disposable paper based electrical sensor to examine the analyte concentration in an extremely small volume of sample solution is essential for environmental and healthcare applications. For the development of paper based devices, sophisticated instruments are essential to pattern electrode on the top surface of the paper. In most cases, such fabricated device results in direct contact with the analyte solution on the surface of the electrode during electrical detection and leads to high electrical double layer capacitance. In this work, we have focused to reduce the double layer capacitance by fabricating hand drawn electrode paper sensor utilising the reverse side of the paper. This design acts as a sample storage and facilitate impedimetric sensing of ionic concentration of analyte solution using a few microlitre. Droplet formation at the bottom of the paper in the confined area is visually monitored to reduce sample wastage. The interaction between two different electrode materials (graphite and silver) on the paper substrate with the different volume and concentration of the electrolyte is analysed to improve the robustness and sensitivity of the measurement. Simultaneously, we observed a reduction in the electrical double layer effect on the low sample volumes. The proposed paper based sensor shows the enhanced impedance stability on silver electrode patterned paper chip than graphite electrode paper chip to detect the different ionic concentration of artificial sweat sample. Finally, it demonstrates that paper chip has great potential as a disposable diagnostics sensor in healthcare applications.
PubDate: 2021-09-01
DOI: 10.1007/s10544-021-00578-9

• Inertial microfluidics: Determining the effect of geometric key parameters
on capture efficiency along with a feasibility evaluation for bone marrow
cells sorting

Abstract: Abstract Despite great developments in inertial microfluidics, there is still a lack of knowledge to precisely define the particles’ behavior in the microchannels. In the present study, as a prerequisite to experimental studies, numerical simulations have been used to study the capture efficiency of target particles in the contraction–expansion microchannel, aiming to provide an estimation of the conditions at which the channel performs best. Fluid analysis based on Navier–Stokes equations is conducted using the finite element method to determine the streamlines and vortices. The highest capture efficiency for 10, 15, and 19-micron particles occurs when the center of the vortex is approximately in the middle of the wide section (at the flow rate of 0.35 ml/min). In addition to investigating the effect of particle diameter and input flow rate, the effect of channel geometry parameters (channel height and initial length of the channel) on particle trapping has also been studied. Also, to consider great interest in separating different-sized bioparticles from a sample, a three-stage platform has been designed to separate four types of bone marrow cells and evaluate the possibility of using contraction–expansion channels in this application.
PubDate: 2021-08-11
DOI: 10.1007/s10544-021-00577-w

• Dean migration of unfocused micron sized particles in low aspect ratio
spiral microchannels

Abstract: Abstract We present an analysis of the microfluidic Dean migration of 2.5 µm particles, which do not meet focus criterion, in tall and low aspect ratio microchannels. We demonstrate the use of such low aspect ratio and tall spirals (h > 50 µm) for isolating high concentration (> 106 particles or cells/mL) micron sized particles without an initial off-chip dilution step. We specifically show the need for a sheath fluid for isolation and systematically analyze the particle stream profile (i.e. thickness and distance from the channel wall) as a function of downstream channel length and curvature ratio, with changes in the fluid velocity and the flow rate ratio of particles to sheath fluid (FRR). We also show that the width of the particle stream can control the particle migration and that a threshold stream width and Dean drag is necessary to initiate the particle stream migration from the channel wall. We then propose a design guide based on the selection of optimum curvatures, flow velocities and the FRRs required for achieving a narrow particle stream through a particular outlet. Finally, we use the design guide to demonstrate the isolation of bacteria from bladder epithelial cells.
PubDate: 2021-07-26
DOI: 10.1007/s10544-021-00575-y

• Copper coating formed by micro-arc oxidation on pure Mg improved
antibacterial activity, osteogenesis, and angiogenesis in vivo and in
vitro

Abstract: Abstract Micro-arc oxidation (MAO) was used to improve the resistance of pure magnesium (Mg). Copper (Cu), a good antibacterial, angiogenic, and osteogenic element, was added by reaction in a Cu-containing electrolyte to improve the osteogenic and pro-angiogenic activities of Mg. The surface microstructures of the resulting MAO were evaluated by a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) mapping. The release of Cu ions was detected by ICP-OES. The antibacterial activity of films with different concentrations of Cu ions was assessed against Staphylococcus aureus (S. aureus). The osteogenesis of films was confirmed by cell morphology and proliferation, ALP activity, alizarin red staining, and osteogenic-related gene expression in the MC3T3-E1 cell line. The angiogenesis of the films was tested in human umbilical vein endothelial cells (HUVECs) by cell migration, tube formation, and VEGF quantification in vitro, and by a chicken embryo chorioallantoic membrane (CAM) assay in vivo. The results showed that the microporous structure was shaped by MAO, and the Cu group was denser and more uniform. The Cu coating showed effective antibacterial activity against S. aureus while also enhancing osteogenesis and angiogenesis in vitro. According to the CAM assay, the Cu group showed not only biocompatibility but also a significant angiogenic response, which was consistent with in vitro studies. The findings indicate that a Cu coating on Mg-MAO enhances osteogenesis and angiogenesis.
PubDate: 2021-07-24
DOI: 10.1007/s10544-021-00573-0

• Fabrication of novel-shaped microneedles to overcome the disadvantages of
solid microneedles for the transdermal delivery of insulin

Abstract: Abstract In this study, we fabricated two different microneedles (MNs) — semi-hollow and bird-bill — to overcome the limitations of solid and coated MNs, respectively. The two MN arrays were developed using a general injection molding process to obtain high-quality MNs with uniform shape. The semi-hollow and bird-bill MNs could penetrate the micropores of swine skin up to depths of 178.5 ± 27.6 µm and 232.1 ± 51.3 µm, respectively. When the semi-hollow MNs were used for the transdermal delivery of insulin in diabetic rats, it was observed that the blood glucose concentration (BGC) decreased remarkably within 30 min, and the desired effect of insulin was maintained for an additional 3 h after the removal of insulin from the skin surface. The bird-bill MN was able to load a coating gel at a maximum capacity of 3.20 ± 0.21 mg per MN array, and the BGC continued to decrease significantly after MN application for up to 2–6 h. In summary, we fabricated semi-hollow and bird-bill MN arrays using the injection molding method; these can be mass produced and are capable of effectively producing micro-holes in the stratum corneum. The two MN arrays could provide effective transdermal delivery of large-molecular-weight drugs such as insulin.
PubDate: 2021-07-21
DOI: 10.1007/s10544-021-00576-x

budesonide-Soluplus film

Abstract: Abstract Micro-reservoir based drug delivery systems have the potential to provide targeted drug release locally in the intestine, i.e. at the inflamed areas of the intestine of patients with inflammatory bowel disease (IBD). In this study, microcontainers with a diameter of 300 µm and a height of 100 µm, asymmetrical geometry and the possibility to provide unidirectional release, are fabricated in the biodegradable polymer poly-ɛ-caprolactone (PCL) using hot punching. As a first step towards local treatment of IBD, a novel method for loading of microcontainers with the corticosteroid budesonide is developed. For this purpose, a budesonide-Soluplus drug-polymer film is prepared by spin coating and loaded into the microcontainer reservoirs using hot punching. The processing parameters are optimized to achieve a complete loading of a large number of containers in a single step. A poly(lactic-co-glycolic acid) (PLGA) 50:50 lid is subsequently applied by spray coating. Solid-state characterization indicates that the drug is in an amorphous state in the drug-polymer films and the in vitro drug release profile showed a 68% release over 10 h. The results demonstrate that hot punching can be employed both as a production and loading method for PCL microcontainers with the perspective of local treatment of IBD.
PubDate: 2021-07-16
DOI: 10.1007/s10544-021-00572-1

• Non-enzymatic and rapid detection of glucose on PVA-CuO thin film using
ARDUINO UNO based capacitance measurement unit

Abstract: Abstract Glucose measurement is one of the essential health monitoring practices for maintaining blood sugar levels. Here, we have fabricated a highly specific capacitive nano-sensor for non-enzymatic glucose detection. Capacitance measurements were carried out on polyvinyl alcohol capped copper oxide (PVA-CuO) thin films on indium tin oxide (ITO) coated glass using ARDUINO UNO. The capacitance study shows a decrease in capacitance with an increase in glucose concentrations. The applicability in real samples was performed by studying the glucose in the presence of fetal bovine serum. Most commonly found interfering agents were used for interference studies, which confirmed the capacitive nano-sensor specificity. The system was further checked for repeatability up to six readings and reproducibility up to 5 chips. The shelf-life study showed stability for four weeks of a chip. These studies indicate that this capacitance-based measurement unit can be used for reliable, rapid, and non-enzymatic detection of glucose in real sample.
PubDate: 2021-07-14
DOI: 10.1007/s10544-021-00568-x

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