Advances in textile-based microfluidics for biomolecule sensing.

Textile-based microfluidic biosensors represent an innovative fusion of various multidisciplinary fields, including bioelectronics, material sciences, and microfluidics. Their potential in biomedicine is significant as they leverage textiles to achieve high demands of biocompatibility with the human body and conform to the irregular surfaces of the body. In the field of microfluidics, fabric coated with hydrophobic materials serves as channels through which liquids are transferred in precise amounts to the sensing element, which in this case is a biosensor. This paper presents a condensed overview of the current developments in textile-based microfluidics and biosensors in biomedical applications over the past 20 years (2005-2024). A literature search was performed using the Scopus database. The fabrication techniques and materials used are discussed in this paper, as these will be key in various modifications and advancements in textile-based microfluidics. Furthermore, we also address the gaps in the application of textile-based microfluidic analytical devices in biomedicine and discuss the potential solutions. Advances in textile-based microfluidics are enabled by various printing and fabric manufacturing techniques, such as screen printing, embroidery, and weaving. Integration of these devices into everyday clothing holds promise for future vital sign monitoring, such as glucose, albumin, lactate, and ion levels, as well as early detection of hereditary diseases through gene detection. Although most testing currently takes place in a laboratory or controlled environment, this field is rapidly evolving and pushing the boundaries of biomedicine, improving the quality of human life.

Enhanced Sweat Biosensing with Thread-Embedded Microfluidic Devices.

BACKGROUND This study explored the integration of conductive threads into a microfluidic compact disc (CD), developed using the xurographic method, for a potential sweat biosensing platform. MATERIAL AND METHODS The microfluidic CD platform, fabricated using the xurographic method with PVC films, included venting channels and conductive threads linked to copper electrodes. With distinct microfluidic sets for load and metering, flow control, and measurement, the CD's operation involved spinning for sequential liquid movement. Impedance analysis using HIOKI IM3590 was conducted for saline and artificial sweat solutions on 4 identical CDs, ensuring reliable conductivity and measurements over a 1 kHz to 200 kHz frequency range. RESULTS Significant differences in |Z| values were observed between saline and artificial sweat treatments. 27.5 µL of saline differed significantly from 27.5 µL of artificial sweat, 72.5 µL of saline from 72.5 µL of artificial sweat, and 192.5 µL of saline from 192.5 µL of sweat. Significant disparities in |Z| values were observed between dry fibers and Groups 2, 3, and 4 (varying saline amounts). No significant differences emerged between dry fibers and Groups 6, 7, and 8 (distinct artificial sweat amounts). These findings underscore variations in fiber characteristics between equivalent exposures, emphasizing the nuanced response of the microfluidic CD platform to different liquid compositions. CONCLUSIONS This study shows the potential of integrating conductive threads in a microfluidic CD platform for sweat sensing. Challenges in volume control and thread coating degradation must be addressed for transformative biosensing devices in personalized healthcare.

Analysis of Covarine Particle in Toothpaste Through Microfluidic Simulation, Experimental Validation, and Electrical Impedance Spectroscopy.

Covarine, copper phthalocyanine, a novel tooth whitening ingredient, has been incorporated into various toothpaste formulations using diverse technologies such as larger flakes, two-phase pastes, and microbeads. In this study, we investigated the behavior of covarine microbeads (200 µm) in Colgate advanced white toothpaste when mixed with artificial and real saliva. Our analysis utilized a custom-designed microfluidic mixer with 400 µm wide channels arranged in serpentine patterns, featuring a Y-shaped design for saliva and toothpaste flow. The mixer, fabricated using stereolithography 3D printing technology, incorporated a flexible transparent resin (Formlabs' Flexible 80A resin) and PMMA layers. COMSOL simulations were performed by utilizing parameters extracted from toothpaste and saliva datasheets, supplemented by laboratory measurements, to enhance simulation accuracy. Experimental assessments encompassing the behavior of covarine particles were conducted using an optical profilometer. Viscosity tests and electrical impedance spectroscopy employing recently developed all-carbon electrodes were employed to analyze different toothpaste dilutions. The integration of experimental data from microfluidic chips with computational simulations offers thorough insights into the interactions of covarine particles with saliva and the formation of microfilms on enamel surfaces.

Oral micro-electronic platform for temperature and humidity monitoring.

Intraoral theranostics, the integration of diagnostics and therapeutics within the oral cavity, is gaining significant traction. This pioneering approach primarily addresses issues like xerostomia (dry mouth), commonly resulting from cancer treatment, with a specific focus on monitoring temperature and humidity. This paper introduces the innovative Intra-Oral Portable Micro-Electronic (IOPM) fluidic theranostic device platform. It leverages conventional dental spoons by incorporating advanced sensors for precise measurements of oral temperature and humidity. Personalization options include a microfluidic chip and a tooth model, enabling targeted delivery of therapeutic agents to optimize treatment outcomes. The electronic control system simplifies the administration of fluid dosages, intelligently adjusted based on real-time oral cavity temperature and humidity readings. Rigorous experimental evaluations validate the platform's precision in delivering fluid volumes at predefined intervals. This platform represents a transformative advancement for individuals contending with oral health challenges such as xerostomia (dry mouth). Furthermore, it has the potential to elevate oral healthcare standards by providing advanced diagnostics and tailored therapeutic solutions, benefiting both patients and dental professionals alike.

A novel microfluidic compact disc to investigate electrochemical property changes between artificial and real salivary samples mixed with mouthwashes using electrical impedance analysis.

Diagnosing oral diseases at an early stage may lead to better preventive treatments, thus reducing treatment burden and costs. This paper introduces a systematic design of a microfluidic compact disc (CD) consisting of six unique chambers that run simultaneously from sample loading, holding, mixing and analysis. In this study, the electrochemical property changes between real saliva and artificial saliva mixed with three different types of mouthwashes (i.e. chlorhexidine-, fluoride- and essential oil (Listerine)-based mouthwashes) were investigated using electrical impedance analysis. Given the diversity and complexity of patient's salivary samples, we investigated the electrochemical impedance property of healthy real saliva mixed with different types of mouthwashes to understand the different electrochemical property which could be a foundation for diagnosis and monitoring of oral diseases. On the other hand, electrochemical impedance property of artificial saliva, a commonly used moisturizing agent and lubricant for the treatment of xerostomia or dry mouth syndrome was also studied. The findings indicate that artificial saliva and fluoride-based mouthwash showed higher conductance values compared to real saliva and two other different types of mouthwashes. The ability of our new microfluidic CD platform to perform multiplex processes and detection of electrochemical property of different types of saliva and mouthwashes is a fundamental concept for future research on salivary theranostics using point-of-care microfluidic CD platform.

Micro and Nano Interdigitated Electrode Array (IDEA)-Based MEMS/NEMS as Electrochemical Transducers: A Review.

Micro and nano interdigitated electrode array (µ/n-IDEA) configurations are prominent working electrodes in the fabrication of electrochemical sensors/biosensors, as their design benefits sensor achievement. This paper reviews µ/n-IDEA as working electrodes in four-electrode electrochemical sensors in terms of two-dimensional (2D) planar IDEA and three-dimensional (3D) IDEA configurations using carbon or metal as the starting materials. In this regard, the enhancement of IDEAs-based biosensors focuses on controlling the width and gap measurements between the adjacent fingers and increases the IDEA's height. Several distinctive methods used to expand the surface area of 3D IDEAs, such as a unique 3D IDEA design, integration of mesh, microchannel, vertically aligned carbon nanotubes (VACNT), and nanoparticles, are demonstrated and discussed. More notably, the conventional four-electrode system, consisting of reference and counter electrodes will be compared to the highly novel two-electrode system that adopts IDEA's shape. Compared to the 2D planar IDEA, the expansion of the surface area in 3D IDEAs demonstrated significant changes in the performance of electrochemical sensors. Furthermore, the challenges faced by current IDEAs-based electrochemical biosensors and their potential solutions for future directions are presented herein.

Role of Nanomaterials in the Fabrication of bioNEMS/MEMS for Biomedical Applications and towards Pioneering Food Waste Utilisation.

bioNEMS/MEMS has emerged as an innovative technology for the miniaturisation of biomedical devices with high precision and rapid processing since its first R&D breakthrough in the 1980s. To date, several organic including food waste derived nanomaterials and inorganic nanomaterials (e.g., carbon nanotubes, graphene, silica, gold, and magnetic nanoparticles) have steered the development of high-throughput and sensitive bioNEMS/MEMS-based biosensors, actuator systems, drug delivery systems and implantable/wearable sensors with desirable biomedical properties. Turning food waste into valuable nanomaterials is potential groundbreaking research in this growing field of bioMEMS/NEMS. This review aspires to communicate recent progress in organic and inorganic nanomaterials based bioNEMS/MEMS for biomedical applications, comprehensively discussing nanomaterials criteria and their prospects as ideal tools for biomedical devices. We discuss clinical applications for diagnostic, monitoring, and therapeutic applications as well as the technological potential for cell manipulation (i.e., sorting, separation, and patterning technology). In addition, current in vitro and in vivo assessments of promising nanomaterials-based biomedical devices will be discussed in this review. Finally, this review also looked at the most recent state-of-the-art knowledge on Internet of Things (IoT) applications such as nanosensors, nanoantennas, nanoprocessors, and nanobattery.

Effect of Radiation Therapy on Microsurgical Deep Inferior Epigastric Perforator Flap Breast Reconstructions: A Matched Cohort Analysis of 4577 Cases.

INTRODUCTION: Breast reconstruction with autologous tissue is a state-of-the art procedure. Several patient-related factors have been identified with regard to the safety and efficacy of these reconstructions. The presented study investigates the impact of prereconstruction radiation on outcomes of deep inferior epigastric perforator (DIEP) free-flap breast reconstructions using largest database available in Europe. MATERIALS AND METHODS: Between 2011 and 2019, 3926 female patients underwent 4577 DIEP flap breast reconstructions in 22 different German breast cancer centers. The cases were divided into a no-radiation (NR) and a radiation (R) group, according to radiation status before reconstruction. Groups were compared with regard to surgical complications and free-flap outcome. RESULTS: Overall, there was no significant difference between the groups regarding the rate of total flap loss [1.9% (NR) vs 2.1% (R), P = 0.743], partial flap loss [0.9% (NR) vs 1.5 (R), P = 0.069], and revision surgery [vascular revision: 4.4% (NR) vs 4.1% (R), P = 0.686; wound revision: 7.6% (NR) vs 9.4% (R), P = 0.122]. However, the patients had a significantly higher risk of developing wound healing disturbances at the recipient site [1.2% (NR) vs 2.1% (R), P = 0.035] and showed significantly longer hospitalization {8 [SD, 8.4 (NR)] vs 9 [SD, 15.4 {R}] days, P = 0.006} after prereconstruction radiation. CONCLUSIONS: Our findings suggest that DIEP flap reconstruction after radiation therapy is feasible. Women with a history of radiation therapy should, however, be informed in detail about the higher risk for wound healing disturbances at the recipient site.

Microplasma direct writing for site-selective surface functionalization of carbon microelectrodes.

Carbon micro- and nanoelectrodes fabricated by carbon microelectromechanical systems (carbon MEMS) are increasingly used in various biosensors and supercapacitor applications. Surface modification of as-produced carbon electrodes with oxygen functional groups is sometimes necessary for biofunctionalization or to improve electrochemical properties. However, conventional surface treatment methods have a limited ability for selective targeting of parts of a surface area for surface modification without using complex photoresist masks. Here, we report microplasma direct writing as a simple, low-cost, and low-power technique for site-selective plasma patterning of carbon MEMS electrodes with oxygen functionalities. In microplasma direct writing, a high-voltage source generates a microplasma discharge between a microelectrode tip and a target surface held at atmospheric pressure. In our setup, water vapor acts as an ionic precursor for the carboxylation and hydroxylation of carbon surface atoms. Plasma direct writing increases the oxygen content of an SU-8-derived pyrolytic carbon surface from ~3 to 27% while reducing the carbon-to-oxygen ratio from 35 to 2.75. Specifically, a microplasma treatment increases the number of carbonyl, carboxylic, and hydroxyl functional groups with the largest increase observed for carboxylic functionalities. Furthermore, water microplasma direct writing improves the hydrophilicity and the electrochemical performance of carbon electrodes with a contact-angle change from ~90° to ~20°, a reduction in the anodic peak to cathodic peak separation from 0.5 V to 0.17 V, and a 5-fold increase in specific capacitance from 8.82 mF∙cm-2 to 46.64 mF∙cm-2. The plasma direct-writing technology provides an efficient and easy-to-implement method for the selective surface functionalization of carbon MEMS electrodes for electrochemical and biosensor applications.

Carbon Nanomaterial-Based Electrochemical Biosensors for Foodborne Bacterial Detection.

The development of easy to use, rapid and sensitive methods for direct detection of foodborne bacterial pathogens has become significantly important due to their impact on human health. In recent years, carbon nanomaterials have been adapted in the fabrication of electrochemical biosensors due to their exceptional combination of intrinsic properties such as high conductivity, stability and biocompatibility that render them as a promising candidate for bio-sensing material. The scope of this review is to provide a brief history of the current methods and different types of electrochemical biosensors used for the detection of bacterial pathogens. We primarily focus on the recent progress and applications of graphene, carbon nanotubes and their derivatives in electrochemical biosensors for foodborne bacterial pathogens detection. Finally, the status and future prospects of carbon-based electrochemical biosensors are also reviewed and discussed.

Microsurgical Reconstruction of the Plantar Foot: Long-Term Functional Outcomes and Quality of Life.

BACKGROUND: When faced with plantar defects, reconstruction of the weight-bearing areas presents unique surgical challenges. Several free flap modalities have been described in this respect, but there remains debate regarding the best-suited flap modality. Aim of this study was to compare free muscle and non-neurotized fasciocutaneous flaps for plantar reconstruction with respect to long-term functional outcomes. METHODS: Overall, 89 patients received 100 free flaps (anterolateral thigh [ALT] n = 46; gracilis n = 54) for plantar reconstruction. The data were screened for patients' demographics, as well as perioperative details. Postoperative complications were accounted for and the two groups compared accordingly. All patients were contacted for a long-term follow-up examination. RESULTS: There were no significant differences between the two groups regarding major (24 vs. 17%; p = 0.366) and minor surgical complications (61 vs. 70%; p = 0.318). However, the ALT group showed a significantly higher need for secondary surgeries (39 vs. 19%; p = 0.022). Sixty-eight patients (76%) returned for long-term follow-up evaluation (mean: 51.2 months, range: 13-71 months). The ALT group showed significantly less pain at the recipient (p = 0.0004) and donor (p = 0.010) sites, and scar assessment revealed significantly better results (p < 0.001). Additionally, the ALT group showed better depth (p = 0.017) and superficial (p = 0.007) sensation and enabled better shoe provision (p = 0.014). CONCLUSION: Both the free ALT and gracilis flaps are well suited for plantar reconstruction, yielding overall similar functional outcomes. However, the ALT flap produces less scarring and pain, while showing better recovery of sensation and enabling better shoe provision. The ALT flap thus presents our preferred option.

Female eye attractiveness - Where beauty meets science.

INTRODUCTION: While periorbital and -ocular surgery ranks amongst the most frequently performed plastic surgical procedures, only scarce information exists regarding the contributing factors of aging and its systematic anatomic assessment. The presented study, based on measuring distinct physical landmarks, aimed to gather data to provide a foundation of in-depth periorbital analysis in order to more clearly define female eye attractiveness. METHODS: 80 probands (age range: 30-50 years, M = 38.4 ± 6.5 years) were asked to judge 60 standardized high-resolution digital pictures of female eye regions in respect to the perceived age (in years) and attractiveness (7-point Likert scale). All photographs were objectively evaluated and measured utilizing a total of 38 distinct landmarks. The data was analyzed by calculating correlations between relevant measured eye area parameters and mean attractiveness ratings including age estimations. RESULTS: Overall, it was found that several specific eye shape features correlate with attractiveness and perceived age. For instance, large visible height of the iris and large upward and lateral inclination of both eye axis and eyebrows correlated moderately to strongly with attractiveness (p < 0.05). CONCLUSION: Regarding the female eye, there exist distinct periorbital anatomic features and landmarks which contribute to a youthful appearance and attractiveness. Knowledge regarding these facts may serve as an important guideline for pre- and post-operative patient analysis.

The lateral arm flap for reconstruction of tissue defects due to olecranon bursitis.

Wound healing problems following acute and chronic olecranon bursitis can result in problematic tissue defects around the elbow. These defects often require a regional flap or a free flap for durable tissue coverage. The aim of this study was to assess clinical outcome the lateral arm flap (LAF) used to cover tissue defects caused by chronic olecranon bursitis. Between 2011 and 2015, 13 patients with soft tissue defects of the elbow resulting from chronic bursitis olecrani were treated in an interdisciplinary approach. First sufficient debridement was performed in conjunction with the orthopedic surgeons. Then, using a defect specific algorithm, reconstruction followed using pedicled extended LAFs or reverse LAFs, with and without inclusion of triceps muscle tissue. Mean follow-up was 52.3 months (range 23-72 months). There were no complete flap losses. All flaps healed in nicely without major wound healing complications. No patient showed signs of recurrent infections during follow-up, and all patients were able to achieve full range of motion post-operatively. Depending on the size of the defect, the conditions of the surrounding tissues, involvement of the elbow joint or need for sensate tissue, reconstruction may require different approaches. In our opinion the LAF can be designed to address these demands.

All-carbon suspended nanowire sensors as a rapid highly-sensitive label-free chemiresistive biosensing platform.

Nanowire sensors offer great potential as highly sensitive electrochemical and electronic biosensors because of their small size, high aspect ratios, and electronic properties. Nevertheless, the available methods to fabricate carbon nanowires in a controlled manner remain limited to expensive techniques. This paper presents a simple fabrication technique for sub-100 nm suspended carbon nanowire sensors by integrating electrospinning and photolithography techniques. Carbon Microelectromechanical Systems (C-MEMS) fabrication techniques allow fabrication of high aspect ratio carbon structures by patterning photoresist polymers into desired shapes and subsequent carbonization of resultant structures by pyrolysis. In our sensor platform, suspended nanowires were deposited by electrospinning while photolithography was used to fabricate support structures. We have achieved suspended carbon nanowires with sub-100 nm diameters in this study. The sensor platform was then integrated with a microfluidic chip to form a lab-on-chip device for label-free chemiresistive biosensing. We have investigated this nanoelectronics label-free biosensor's performance towards bacterial sensing by functionalization with Salmonella-specific aptamer probes. The device was tested with varying concentrations of Salmonella Typhimurium to evaluate sensitivity and various other bacteria to investigate specificity. The results showed that the sensor is highly specific and sensitive in detection of Salmonella with a detection limit of 10 CFU mL-1. Moreover, this proposed chemiresistive assay has a reduced turnaround time of 5 min and sample volume requirement of 5 µL which are much less than reported in the literature.

The ideal ear position in Caucasian females.

PURPOSE: Ear position contributes significantly to facial appearance. However, while objective measurements remain the foundation for esthetic evaluations, little is known about how an ear should ideally be positioned regarding its rotational axis. This study aimed to further evaluate whether there exists a universally applicable ideal ear axis, and how sociodemographic factors impact such preferences. MATERIALS AND METHODS: An interactive online survey was designed, enabling participants to change the axis of a female model's ear in terms of its forward and backward rotation. The questionnaire was sent out internationally to plastic surgeons and the general public. Demographic data were collected and analysis of variance was used to investigate respective preferences. RESULTS: A total of 1016 responses from 35 different countries (response rate: 18.5%) were gathered. Overall, 60% of survey takers chose the minus 10 or 5° angles to be most attractive. Significant differences were found regarding sex, ethnicity, country of residence, profession and respective ear axis preferences. CONCLUSION: Across multiple countries and ethnicities, an ear position in slight reclination of minus 5-10° is considered most pleasing in Caucasian females. However, sociodemographic factors significantly impact individual ear axis preferences and should be taken into consideration when performing reconstructive ear surgery.

The spreaded gracilis flap revisited: Comparing outcomes in lower limb reconstruction.

BACKGROUND: In lower limb reconstruction, the free gracilis muscle flap is usually chosen for coverage of small- to medium-sized defects. Aim of this study was a re-appraisal regarding the reconstructive indications of the gracilis muscle flap with a focus on postoperative complications in order to evaluate if it can also be routinely used to reconstruct large-size lower limb defects. METHODS: A total of 204 patients underwent free gracilis muscle transfers for lower limb reconstruction at our institution. Cases were divided according to the size of the defect into two groups (<150 cm2 versus ≥150 cm2 ). The small- to medium defect size group included 150 patients and the large defect size group included 54 patients. In the large defect size group, the muscle was enlarged as needed by careful dissection of the epimysium and all connective tissue surrounding the intrinsic vessels under loupe magnification to protect the muscle perfusion. Surgical complications were accounted for and the two groups compared accordingly. RESULTS: Overall, there were no significant differences between the two groups of patients regarding the rate of major (15.72% versus 10.91%; P = .506) and minor surgical complications (6.92% versus 3.64%; P = .522). The total percentage of flap losses in the small to medium defect size group was 5.03%. There were no total flap losses in the large defect size group (P = .117). CONCLUSION: The use of the spreaded gracilis flap provides a valuable option for the microsurgeon, especially also to reconstruct large size lower limb defects.

A Colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) Detection Platform for a Point-of-Care Dengue Detection System on a Lab-on-Compact-Disc.

The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings.

A portable automatic endpoint detection system for amplicons of loop mediated isothermal amplification on microfluidic compact disk platform.

In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP) on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV) emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD). The sensitivity test has been performed with detection limit up to 2.5 × 10(-3) ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis device for foodborne pathogens detection in a resource-limited environment.

Soft tissue perineurioma and other unusual tumors in a patient with neurofibromatosis type 1.

Perineurioma is a rare benign peripheral nerve sheath tumor featuring perineurial differentiation. Perineurioma occurs sporadically with only one reported case in the setting of neurofibromatosis type 1 (NF-1). We present a 6.7-cm soft tissue perineurioma of the lower leg in a 51-year-old man with proven NF-1. The tumor displayed whorled and fascicular pattern with infiltrative margins and expressed EMA, GLUT-1, claudin-1, and CD34. Electron microscopy confirmed diagnosis. Furthermore, lipomatosis, cutaneous angiomatous nodules, vasculopathy, and iliac spine lesion consistent with non-ossifying fibroma were observed. Tumor DNA revealed no NF2 mutations or chromosomal aberrations but a germline NF1-deletion (c.449_502delTGTT) was detected in his blood sample. His brother displayed neurofibromas, duodenal ganglioneuroma and colonic juvenile polyp, and his mother a neurofibroma, cutaneous squamous cell carcinoma, and jejunal gastrointestinal stromal tumor (GIST); both were affected by NF-1. In conclusion, perineurioma may rarely be NF-1 related and should be included in the spectrum of neoplasms occurring in this disorder.