The use of gold and magnetite-gold composite nanoparticles for the enhanced detection of Salmonella LT2 cells under photoacoustic flow cytometry.

Photoacoustic flow cytometry (PAFC) is an emerging technology that has generated significant interest in several research fields, particularly in bacteremia. The application of functionalised nanoparticles like gold and iron oxide-gold complex (FeO-Au) has been realised to enhance the photoacoustic (PA) detection of bacteria cells under PAFC systems. Inclusively, the bacteria cell concentrations are statistically quantified through the number of time-signal detection counts.

The relevance of current forensic firearms examination techniques when applied to 3D printed firearms.

This research project had two major objectives. The first was to successfully print and fire the Liberator, a 3D-printed firearm, to assess its feasibility as a lethal weapon. The second objective was to identify any individual characteristics that might be deposited during the firing process by the firearm.

Cost-Effective Full-Color 3D Dental Imaging Based on Close-Range Photogrammetry.

Dental imaging plays a crucial role in clinical dental practice. Conventional 2D dental imaging serves general-purpose tasks, such as patient documentation, while high-precision 3D dental scanning is tailored for specialized procedures, such as orthodontics and implant surgeries. In this study, we aimed to develop a cost-effective 3D imaging technique that could bridge the gap between conventional dental photography and high-precision 3D dental scanning, with the goal of improving patient dental care.

The Application of Bacteriophage and Photoacoustic Flow Cytometry in Bacterial Identification.

Infection with resistant bacteria has become an ever-increasing problem in modern medical practice. Bacteremia is a serious and potentially lethal condition that can lead to sepsis without early intervention. Currently, broad-spectrum antibiotics are prescribed until bacteria can be identified through blood cultures, a process that can take 2-3 days and is unable to provide quantitative information.

Photoacoustic Flow Cytometry Using Functionalized Microspheres for Selective Detection of Bacteria.

Photoacoustic flow cytometry is a method to detect rare analytes in fluids. We developed photoacoustic flow cytometry to detect pathological cells in body fluids, such as circulating tumor cells or bacteria in blood. In order to induce specific optical absorption in bacteria, we use modified bacteriophage that precisely target bacterial species or subspecies for rapid identification.

Differentiating methicillin resistant and susceptible from ocular infections using photoacoustic labeling.

Introduction: Antibiotic resistance in bacterial species constitutes a growing problem in the clinical management of infections. Not only does it limit therapeutic options, but application of ineffective antibiotics allows resistant species to progress prior to prescribing more effective treatment to patients. Methicillin resistance in is a major problem in clinical infections as it is the most common hospital acquired infection.

Photoacoustic discrimination of antibiotic-resistant and sensitive Staphylococcus aureus isolates.

Objectives: Bacteremia is a serious and potentially lethal condition. Staphylococcus aureus is a leading cause of bacteremia and methicillin-resistant S. aureus (MRSA) accounts for more than a third of the cases.

Photoacoustic detection of circulating melanoma cells in late stage patients.

Melanoma is the deadliest skin cancer and is responsible for over 7000 deaths in the US annually. The spread of cancer, or metastasis, is responsible for these deaths, as secondary tumors interrupt normal organ function. Circulating tumor cells, or those cells that spread throughout the body from the primary tumor, are thought to be responsible for metastasis.

Capture and Isolation of Circulating Melanoma Cells Using Photoacoustic Flowmetry.

Early detection of cancer has been a goal of cancer research in general and melanoma research in particular (Birnbaum et al., Lancet Glob Health 6:e885-e893, 2018; Alendar et al., Bosnian J Basic Med Sci 9:77-80, 2009).

Predicting Metastasis in Melanoma by Enumerating Circulating Tumor Cells Using Photoacoustic Flow Cytometry.

Background And Objectives: Enumerating circulating tumor cells has been used as a method of monitoring progression of various cancers. Various methods for detecting circulating melanoma cells (CMCs) have been reported, but none has had sufficient sensitivity to determine if the presence of rare CMCs in the blood of Stage I-III melanoma patients predicts if those patients eventually develop metastatic disease.

Study Design: We quantified CMCs in serial blood samples from 38 early stage melanoma patients to determine if CMC numbers predict development of metastatic melanoma.

Bacteriophage-mediated identification of bacteria using photoacoustic flow cytometry.

Infection with resistant bacteria has become an ever increasing problem in modern medical practice. Currently, broad spectrum antibiotics are prescribed until bacteria can be identified through blood cultures, a process that can take two to three days and is unable to provide quantitative information. To detect and quantify bacteria rapidly in blood samples, we designed a method using labeled bacteriophage in conjunction with photoacoustic flow cytometry (PAFC).

The Nurse-Engineer: A New Role to Improve Nurse Technology Interface and Patient Care Device Innovations.

Purpose: The purpose of this article is to describe two innovative biomedical engineering and nursing collaborations designed to educate a new cadre of professionals and develop new knowledge and innovations (robots, patient care devices, and computer simulation).

Organizing Construct: Complex health problems demand a highly skilled response that uses teams of professionals from various disciplines. When the biomedical engineering lens is expanded to include the practical perspective of nursing, opportunities emerge for greater technology-nurse interface and subsequent innovation.

Role of branchiomotor neurons in controlling food intake of zebrafish larvae.

The physical act of eating or feeding involves the coordinated action of several organs like eyes and jaws, and associated neural networks. Moreover, the activity of the neural networks controlling jaw movements (branchiomotor circuits) is regulated by the visual, olfactory, gustatory and hypothalamic systems, which are largely well characterized at the physiological level. By contrast, the behavioral output of the branchiomotor circuits and the functional consequences of disruption of these circuits by abnormal neural development are poorly understood.

Detection and capture of breast cancer cells with photoacoustic flow cytometry.

According to the Centers for Disease Control and Prevention, breast cancer is the most common cancer and the second leading cause of cancer related deaths among women. Metastasis—the presence of secondary tumors caused by the spread of cancer cells via the circulatory or lymphatic systems—significantly worsens the prognosis of any breast cancer patient. A technique is developed to detect circulating breast cancer cells in human blood using a photoacoustic flow cytometry method.

Capture and Isolation of Circulating Melanoma Cells Using Photoacoustic Flowmetry.

Circulating tumor cells (CTCs) are those cells that separate from a solid tumor and spread through the blood or lymphatic systems. While there are many open questions concerning the biology of CTCs, there is mounting evidence that some of these cells go on to create secondary tumors in distant organs, thus enabling metastatic disease. Detection of CTCs may have clinical impact by providing prognostic information.

Quantitative photoacoustics to measure single cell melanin production and nanoparticle attachment.

Photoacoustics can be used as a label-free spectroscopic method of identifying pigmented proteins and characterizing their intracellular concentration over time in a single living cell. The authors use a microscopic laser irradiation system with a 5 ns, Q-switched laser focused onto single cells in order to collect photoacoustic responses of melanoma cells from the HS936 cell line and gold nanoparticle labeled breast cancer cells from the T47D cell line. The volume averaged intracellular concentration of melanin is found to range from 29-270 mM for single melanoma cells and the number of gold nanoparticles (AuNP) is shown to range from 850-5900 AuNPs/cell.

Photoacoustic measurement of refractive index of dye solutions and myoglobin for biosensing applications.

Current methods of determining the refractive index of chemicals and materials, such as ellipsometry and reflectometry, are limited by their inability to analyze highly absorbing or highly transparent materials, as well as the required prior knowledge of the sample thickness and estimated refractive index. Here, we present a method of determining the refractive index of solutions using the photoacoustic effect. We show that a photoacoustic refractometer can analyze highly absorbing dye samples to within 0.

Detection of circulating tumor cells by photoacoustic flowmetry.

Detection of circulating tumor cells (CTCs) in human blood and lymph systems has the potential to aid clinical decision making in the treatment of cancer (Cristofanilli et al. New Engl J Med 351:781-791, 2004; Check Cap Today 19:1.76-1.

Nanoparticle mediated thermal ablation of breast cancer cells using a nanosecond pulsed electric field.

In the past, ablation of cancer cells using radiofrequency heating techniques has been demonstrated, but the current methodology has many flaws, including inconsistent tumor ablation and significant ablation of normal cells. Other researchers have begun to develop a treatment that is more selective for cancer cells using metallic nanoparticles and constant electric field exposure. In these studies, cell necrosis is induced by heating antibody functionalized metallic nanoparticles attached to cancer cells.

Optically absorbing nanoparticle mediated cell membrane permeabilization.

Membrane permeabilization is imperative for gene and drug delivery systems, along with other cell manipulation methods, since the average eukaryotic cell membrane is not permeable to polar and large nonpolar molecules. Antibody conjugated optically absorbing gold nanospheres are targeted to the cell membrane of T47D breast cancer cell line and irradiated with 5 ns pulse, 20 Hz, 532 nm light to increase membrane permeability. Up to 90% permeabilization with less than 6% death is reported at radiant exposures up to 10 times lower than those of other comparable studies.

Photoacoustic spectroscopy of β-hematin.

Malaria affects over 200 million individuals annually, resulting in 800,000 fatalities. Current tests use blood smears and can only detect the disease when 0.1-1% of blood cells are infected.

Capture of circulating tumor cells using photoacoustic flowmetry and two phase flow.

Melanoma is the deadliest form of skin cancer, yet current diagnostic methods are unable to detect early onset of metastatic disease. Patients must wait until macroscopic secondary tumors form before malignancy can be diagnosed and treatment prescribed. Detection of cells that have broken off the original tumor and travel through the blood or lymph system can provide data for diagnosing and monitoring metastatic disease.

Total internal reflection photoacoustic spectroscopy for the detection of β-hematin.

Evanescent field sensing methods are currently used to detect many different types of disease markers and biologically important chemicals such as the HER2 breast cancer receptor. Hinoue et al. used Total Internal Reflection Photoacoustic Spectroscopy (TIRPAS) as a method of using the evanescent field to detect an optically opaque dye at a sample interface.

Detection and isolation of circulating melanoma cells using photoacoustic flowmetry.

Circulating tumor cells (CTCs) are those cells that have separated from a macroscopic tumor and spread through the blood and lymph systems to seed secondary tumors(1,2,3). CTCs are indicators of metastatic disease and their detection in blood samples may be used to diagnose cancer and monitor a patient's response to therapy. Since CTCs are rare, comprising about one tumor cell among billions of normal blood cells in advanced cancer patients, their detection and enumeration is a difficult task.