Glutamate (Glu) and histamine (His) are two major neurotransmitters that play many critical roles in brain physiological functions and neurological disorders. Therefore, specific and sensitive monitoring of Glu and His is essential in the diagnosis and treatment of various mental health and neurodegenerative disorders. Both being non-electroactive species, direct electrochemical detection of Glu and His has been challenging.
View Article and Find Full Text PDFCentral nervous system (CNS) tumors are the leading cause of cancer-related death in children. Typical therapy for CNS tumors in children involves a combination of surgery, radiation, and chemotherapy. While upfront therapy is effective for many high-grade tumors, therapy at the time of relapse remains limited.
View Article and Find Full Text PDFBiosensors (Basel)
November 2023
Serotonin (5-HT) is a critical neurotransmitter involved in many neuronal functions, and 5-HT depletion has been linked to several mental diseases. The fast release and clearance of serotonin in the extracellular space, low analyte concentrations, and a multitude of interfering species make the detection of serotonin challenging. This work presents an electrochemical aptamer-based biosensing platform that can monitor 5-HT continuously with high sensitivity and selectivity.
View Article and Find Full Text PDFAntigen heterogeneity that results in tumor antigenic escape is one of the major obstacles to successful chimeric antigen receptor (CAR) T cell therapies in solid tumors including glioblastoma multiforme (GBM). To address this issue and improve the efficacy of CAR T cell therapy for GBM, we developed an approach that combines CAR T cells with inhibitor of apoptosis protein (IAP) antagonists, a new class of small molecules that mediate the degradation of IAPs, to treat GBM. Here, we demonstrated that the IAP antagonist birinapant could sensitize GBM cell lines and patient-derived primary GBM organoids to apoptosis induced by CAR T cell-derived cytokines, such as tumor necrosis factor.
View Article and Find Full Text PDFPrior to adoptive transfer, CAR T cells are activated, lentivirally infected with CAR transgenes, and expanded over 9 to 11 days. An unintended consequence of this process is the progressive differentiation of CAR T cells over time in culture. Differentiated T cells engraft poorly, which limits their ability to persist and provide sustained tumor control in hematologic as well as solid tumors.
View Article and Find Full Text PDFThe use of highly crosslinked molecularly imprinted polymers as a synthetic target receptor has the limitations of restricted accessibility to the binding sites resulting in slow response time. Moreover, such artificial receptors often require additional transduction mechanisms to translate target binding events into measurable signals. Here, we propose the development of a single-chain stimuli-responsive templated polymer, without using any covalent interchain crosslinkers, as a target recognition element.
View Article and Find Full Text PDFAptamer-immobilized graphene field-effect transistors (GFETs) have become a well-known detection platform in the field of biosensing with various biomarkers such as proteins, bacteria, virus, as well as chemicals. A conventional aptamer immobilization technique on graphene involves a two-step crosslinking process. In the first step, a pyrene derivative is anchored onto the surface of graphene and, in the second step, an amine-terminated aptamer is crosslinked to the pyrene backbone with EDC/NHS (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide) chemistry.
View Article and Find Full Text PDFCell-based immunotherapies using T cells that are engineered to express a chimeric antigen receptor (CAR-T cells) are an effective treatment option for several B cell malignancies. Compared with most drugs, CAR-T cell products are highly complex, as each cell product is composed of a heterogeneous mixture of millions of cells. The biodistribution and kinetics of CAR-T cells, following administration, are unique given the ability of T cells to actively migrate as well as replicate within the patient.
View Article and Find Full Text PDFInt Solid State Sens Actuators Microsyst Conf
June 2019
We present a novel electrochemical biosensing platform for the detection of neurotransmitter glutamate using templated polymer-based target receptors. Our sensing approach demonstrates, for the first time, a non-enzymatic approach without the need of glutamate oxidase, leading to a more specific and rapid response. The proposed detection principle is based on the following two claims: (1) our templated polymer-based receptor results in specific molecular recognition of the target glutamate and, (2) upon target binding, the polymer undergoes a conformation change which can then be measured via electrochemical techniques.
View Article and Find Full Text PDFMicromachines (Basel)
July 2020
Printable and flexible electronic materials have gained a tremendous amount of interest both in academia and in industry, due to their potential impact in many areas, including advanced manufacturing, healthcare, diagnostics, wearables, renewable energy, and defense, to name a few [...
View Article and Find Full Text PDFLab-on-a-chip technology offers an ideal platform for low-cost, reliable, and easy-to-use diagnostics of key biomarkers needed for early screening of diseases and other health concerns. In this work, a graphene field-effect transistor (GFET) functionalized with target-binding aptamers is used as a biosensor for the detection of thrombin protein biomarker. Furthermore, this GFET is integrated with a microfluidic device for enhanced sensing performances in terms of detection limit, sensitivity, and continuous monitoring.
View Article and Find Full Text PDFAptamers are oligonucleotides or peptides that are selected from a pool of random sequences that exhibit high affinity toward a specific biomolecular species of interest. Therefore, they are ideal for use as recognition elements and ligands for binding to the target. In recent years, aptamers have gained a great deal of attention in the field of biosensing as the next-generation target receptors that could potentially replace the functions of antibodies.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2019
We report a novel single-chain polymer-based chemical receptor that can be used for the label-free electrochemical detection of an analyte with high selectivity. The polymer was developed using poly-N-isopropylacrylamide (pNIPAM) as a backbone structure in addition to other functional monomers that are used to imprint the template molecule 4-nitrophenol. The polymer also contains a redox reporting monomers (ferrocene) which create a change in the electrochemical signal upon molecular recognition.
View Article and Find Full Text PDFSelective and rapid detection of biomarkers is of utmost importance in modern day health care for early stage diagnosis to prevent fatal diseases and infections. Among several protein biomarkers, the role of lysozyme has been found to be especially important in human immune system to prevent several bacterial infections and other chronic disease such as bronchopulmonary dysplasia. Thus, real-time monitoring of lysozyme concentration in a human body can pave a facile route for early warning for potential bacterial infections.
View Article and Find Full Text PDFWith recent advances in biotechnology, mammalian cells are used in biopharmaceutical industries to produce valuable protein therapeutics and investigated as effective therapeutic agents to permanently degenerative diseases in cell based therapy. In these exciting and actively expanding fields, a reliable, efficient, and affordable platform to culture mammalian cells on a large scale is one of the most vital necessities. To produce and maintain a very large population of anchorage-dependent cells, a microcarrier-based stirred tank bioreactor is commonly used.
View Article and Find Full Text PDFRecently, inkjet-printing has gained increased popularity in applications such as flexible electronics and disposable sensors, as well as in wearable sensors because of its multifarious advantages. This work presents a novel, low-cost immobilization technique using inkjet-printing for the development of an aptamer-based biosensor for the detection of lysozyme, an important biomarker in various disease diagnosis. The strong affinity between the carbon nanotube (CNT) and the single-stranded DNA is exploited to immobilize the aptamers onto the working electrode by printing the ink containing the dispersion of CNT-aptamer complex.
View Article and Find Full Text PDFNanomaterials (Basel)
August 2013
One dimensional polyaniline nanowire is an electrically conducting polymer that can be used as an active layer for sensors whose conductivity change can be used to detect chemical or biological species. In this review, the basic properties of polyaniline nanowires including chemical structures, redox chemistry, and method of synthesis are discussed. A comprehensive literature survey on chemiresistive/conductometric sensors based on polyaniline nanowires is presented and recent developments in polyaniline nanowire-based sensors are summarized.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2013
A pH sensor based on chemiresistive polyaniline nanowires, which makes use of the pH responsive conductivity of the polymer, requires an electrochemical system during measurements in order to maintain its oxidation state. In this work, we have developed an integrated electrochemical device where a reference, a counter, and a pair of working electrodes are all fabricated on a single chip. The polyaniline nanowires are grown between this pair of working electrodes that are separated by a microscale gap.
View Article and Find Full Text PDFAm J Orthop (Belle Mead NJ)
July 2007
Treatment of high-grade isthmic and dysplastic spondylolisthesis in children and adolescents remains a challenge. Surgical treatment of spondylolisthesis has been recommended in adolescents with pain refractory to nonoperative modalities, slippage progression, or > 50% slippage on presentation. Controversy exists as to the optimal surgical approach for high-grade spondylolisthesis.
View Article and Find Full Text PDFStudy Design: A retrospective study. OBJECTIVE.: To decipher the incidence, characteristics, functional outcomes, and complications of spinal fusion after revision surgery for recurrent pseudarthrosis in adult patients with scoliosis.
View Article and Find Full Text PDFBackground Context: Axial back pain affects a large percentage of the population. Often aggravated by weight-bearing activity, these patients frequently have associated degenerative or post-traumatic lumbar disc disease. Aquatherapy is frequently used to transition patients from less activity limited by pain to greater activity by reducing weight-bearing load of the lumbar spine.
View Article and Find Full Text PDFObjective: To describe the extraosseous blood supply of the tibia and how the blood supply of the distal tibia is influenced by different plating techniques.
Design: Microdissection of cadaveric adult hip disarticulation specimens following sequential arterial injections of india ink and Ward's Blue Latex was performed. Readily identifiable arterioles measured approximately 0.
Spine (Phila Pa 1976)
June 2002
Study Design: A prospective clinical trial to study the radiographic parameters and functional outcome in patients undergoing spinal osteotomy.
Objectives: To determine whether correction of specific radiographic parameters is associated with improved functional outcome.
Summary Of Background Data: Although vertebral osteotomies have been shown to improve functional outcome in patients with spinal deformity, no prospective reports have studied whether correction of specific radiographic parameters is associated with improvement in functional outcome.