BioPhotonics Preview - March/April 2023
OCT & Alzheimer's
Alzheimer's disease is a progressive condition resulting in the loss of mental abilities. During the last 15 years there have been more than 500 trials of therapeutic agents with an overwhelming failure rate. Most studies lasted 1.5 to 3 years, yet their clinical endpoint - where effectiveness could officially be proven or disproven - would require 5-10 years. the early detection of neurologic damage and the efficacy of treatment at the microscopic level will reduce research costs and is a prerequisite for the development of potential cures. Optical coherence tomography (OCT) images have demonstrated thinning of the retinal nerve fiber and ganglion cell layers in patients with Alzheimer's disease. Obviously, the early molecular effects of the condition would manifest in the later changes in retinal imaging. Dynamic Light Scattering (DLS) measures the scattered light intensity fluctuations resulting from thermal random motion (Brownian motion), and has already proven useful in the detection of both early cataract formation and of diabetes in humans. A clinical retinal DLS instrument has been developed an in a proof-of-concept study, significant differences in measurements in patients with Alzheimer's disease were observed, well before other methods captured that information, in some cases even before the clinical diagnosis was confirmed. The development of an early, noninvasive, quantitative test to diagnose Alzheimer's disease will lead to differentiating effective treatments and hopefully, to successful therapy before dementia is irreversible.
Key Technologies: Optical coherence tomography, dynamic light scattering
Photoacoustic Microscopy
Acoustically detecting the optical absorption contrast, photoacoustic microscopy (PAM) has become an enabling tool in biomedical studies, with its high spatial resolution, intrinsic sensitivity to functional information, and relatively deep penetration in tissues. In recent years, enabled by the innovative imaging mechanisms, scanning technologies, and the resultant high imaging throughput, it has become feasible to implement high-speed PAM to image otherwise challenging targets that are sensitive to dynamic changes and/or prone to motion artifacts, such as whole brain functions of small animals in response to pathological challenges. Moreover, various miniaturized high-speed PAM systems have been developed for handheld, wearable, and even head-mounted applications, enabling the study of highly dynamic physiologic and pathophysiologic processes, such as longitudinal monitoring of rare circulating tumor cells of melanoma patients. All these technical innovations have allowed the acceleration of PAM systems without sacrificing the imaging performance, and broadened their applications in life sciences.
Key Technologies: photoacoustic microscopy
Raman Spectroscopy
Raman spectroscopy is a non-destructive technique that identifies the molecular makeup of samples by analyzing their vibrational modes and the scattering of photons. It is label-free and critical for applications ranging from pharmaceuticals, to microbiology, to regenerative medicine. Learn about the basic principles of Raman spectroscopy, how to construct a successful Raman system, and how this technique compares to other approaches like FTIR spectroscopy. Raman spectroscopy can identify and analyze biological samples with high sensitivity and precision.
Key Technologies: Raman spectroscopy, FTIR spectroscopy, Nd:YAG lasers, CCD, bandpass filters, SERS
Apatamer Molecular Photonic Beacons
Aptamers are short sequences (oligonucleotides) of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) that bind to a specific target molecule. The affinity can be very high. A single change in the target sequence changes affinity by 10000 times. By conjugating an antisense, a fluorophore and a quencher, an aptamer molecular photonic beacon is formed. When the aptamer binds to the target the antisense separates and on receipt, the fluorophores emit a photon at Stoke shift from the excited photon. The AMPB is provided in 1 mL PBS solution in a 5 mL vial. Saliva/blood sample of 100 microL is introduced into the vial. The resulting emission of photons can be measured by a simple smartphone and the image analyzed using advanced algorithms such as FFT and inverse FFT. Embedded GS-1 code on the vial label can be read to identify the test being carried, mitigating human errors. This technology bridges the gap between biological diagnostics and physics, bringing instant diagnostics to the digital world, from cloud storage of test results, demographical data on the dynamics of pandemics, rates of recovery and AI.
Key Technologies: aptamer molecular photonic beacons, AI, fluorescence quenchers,
See Pricing
>
LATEST NEWS