Miniaturized Biomedical Sensors for Enumeration of Extracellular Vesicles

A Miniature Biomedical Sensor for Rapid Detection of Schistosoma japonicum Antibodies

Schistosomiasis, typically characterized by chronic infection in endemic regions, has the potential to affect liver tissue and pose a serious threat to human health. Detecting and screening for this disease early on is crucial for its prevention and control. However, existing methods encounter challenges such as low sensitivity, time-consuming processes, and complex sample handling. To address these challenges, we report a soluble egg antigen (SEA)-based functionalized gridless and meander-type AlGaN/GaN high electron mobility transistors (HEMT) sensor for the highly sensitive detection of antibodies to Schistosoma japonicum. Immobilization of the self-assembled membrane on the gate surface was verified using a semiconductor parameter analyzer, scanning electron microscope (SEM), and atomic force microscopy (AFM). The developed biosensor demonstrates remarkable performance in detecting anti-SEA, exhibiting a linear concentration range of 10 ng/mL to 100 μg/mL and a sensitivity of 0.058 mA/log (ng/mL). It also exhibits similar excellent performance in serum systems. With advantages such as rapid detection, high sensitivity, miniaturization, and label-free operation, this biosensor can fulfill the requirements for blood defense.

Status and Prospects of Heterojunction-Based HEMT for Next-Generation Biosensors

High electron mobility transistor (HEMT) biosensors hold great potential for realizing label-free, real-time, and direct detection. Owing to their unique properties of two-dimensional electron gas (2DEG), HEMT biosensors have the ability to amplify current changes pertinent to potential changes with the introduction of any biomolecules, making them highly surface charge sensitive. This review discusses the recent advances in the use of AlGaN/GaN and AlGaAs/GaAs HEMT as biosensors in the context of different gate architectures. We describe the fundamental mechanisms underlying their operational functions, giving insight into crucial experiments as well as the necessary analysis and validation of data. Surface functionalization and biorecognition integrated into the HEMT gate structures, including self-assembly strategies, are also presented in this review, with relevant and promising applications discussed for ultra-sensitive biosensors. Obstacles and opportunities for possible optimization are also surveyed. Conclusively, future prospects for further development and applications are discussed. This review is instructive for researchers who are new to this field as well as being informative for those who work in related fields.

Ophthalmic Solution of Smart Supramolecular Peptides to Capture Semaphorin 4D against Diabetic Retinopathy

Diabetic retinopathy (DR) is the leading cause of vision loss in working age population. Intravitreal injection of anti-VEGF antibody is widely used in clinical practice. However, about 27% of patients show poor response to anti-VEGF therapy and about 50% of these patients continue to have macular thickening. Frequent intravitreal injections of antibody may increase the chance of endophthalmitis and cause visual loss or even blindness once happened. Therefore, there is a greatly urgent need for novel noninvasive target to treat DR clinically. Here, the formulation of a smart supramolecular peptide (SSP) eye drop for DR treatment that is effective via specifically identifying and capturing soluble semaphorin 4D (sSema4D), a strongly pro-angiogenesis and exudates factor, is reported. The SSP nanostructures encapsulate sSema4D so that all biological effects mediated by three receptors of sSema4D are inhibited, thereby significantly alleviating pathological retinal angiogenesis and exudates in DR. Moreover, it is found that combination of SSPs eye drop and anti-VEGF injection shows better therapeutic effect over anti-VEGF treatment alone. Overall, SSP eye drop provide an alternative and effective method for noninvasive treatment for DR.

Nanotechnology in ovarian cancer: Diagnosis and treatment

To overcome the drawbacks of conventional delivery, this review spotlights a number of nanoscale drug delivery systems, including nanoparticles, liposomes, nano micelles, branched dendrimers, nanocapsules, and nanostructured lipid formulations for the targeted therapy of ovarian cancer. These nanoformulations offer numerous advantages to promote therapeutic drug delivery such as nontoxicity, biocompatibility, good biodegradability, increased therapeutic impact than free drugs, and non-inflammatory effects. Importantly, the development of specific ligands functionalized nanoformulations enable preferential targeting of ovarian tumors and eventually amplify the therapeutic potential compared to nonfunctionalized counterparts. Ovarian cancer is typically identified by biomarker assessment such as CA125, HE4, Mucin 1, and prostatic. There is, nevertheless, a tremendous demand for less costly, faster, and compact medical tools, both for timely detection and ovarian cancer control. This paper explored multiple types of tumor marker-based on nanomaterial biosensors. Initially, we mention different forms of ovarian cancer biomarkers involving CA125, human epididymis protein 4 (HE4), mucin 1 (MUC1), and prostate. It is accompanied by a brief description of new nanotechnology methods for diagnosis. Nanobiosensors for evaluating ovarian cancer biomarkers can be categorized based on electrochemical, optical, paper-based, giant magnetoresistive, and lab-on-a-chip devices.

Optical, electrochemical and electrical (nano)biosensors for detection of exosomes: A comprehensive overview

Exosomes are small extracellular vesicles involved in many physiological activities of cells in the human body. Exosomes from cancer cells have great potential to be applied in clinical diagnosis, early cancer detection and target identification for molecular therapy. While this field is gaining increasing interests from both academia and industry, barriers such as supersensitive detection techniques and highly-efficient isolation methods remain. In the clinical settings, there is an urgent need for rapid analysis, reliable detection and point-of-care testing (POCT). With these challenges to be addressed, this article aims to review recent developments and technical breakthroughs including optical, electrochemical and electrical biosensors for exosomes detection in the field of cancer and other diseases and demonstrate how nanobiosensors could enhance the performance of conventional sensors. Working strategies, limit of detections, advantages and shortcomings of the studies are summarized. New trends, challenges and future perspectives of exosome-driven POCT in liquid biopsy have been discussed.