Light-based Technologies Research Articles

Dynamic Light Cages: Putting Absorbing Matter Behind Bars

Ubiquitous miniaturization requires an everchanging tool set for handling, controlling and manipulating on the micro- and nanoscale. Light-based technologies like optical tweezers provide the contactless high-precision treatment needed for work done at these scales. Holographic optical tweezers (HOT) are used in hundreds of interdisciplinary applications, allowing researchers to move many dielectric particles and biological specimens in 3-D.

New Frontiers in Laser Surgery

The simultaneous advances in engineering, medicine, and molecular biology have accelerated the pace of introductions of new light-based technologies in dermatology. In this review, the authors examine recent advances in laser surgery as well as peer into the future of energy-based cutaneous medicine. The future landscape of dermatology will almost undoubtedly include (1) noninvasive imaging technologies and (2) improved "destructive" modalities based on real-time feedback from the skin surface.

Invasive imaging technologies

Since the introduction of intravascular, catheter-based invasive imaging and diagnostic tools in the catheterization laboratories two decades ago, the functional assessment of angiographically moderate or ambiguous lesions by fractional flow reserve measurements represents the established standard of care today. Likewise, intravascular ultrasound (IVUS) is widely accepted to guide treatment strategy in complex lesions, such as long or left main stem lesions. Developments are driven by the clinical interest to optimize treatment, prevent periprocedural complications, understand treatment failure and understand progression of atherosclerosis. As a result, a variety of devices are now clinically available that enable detection and monitoring of specific plaque features over time, such as the presence of necrotic core by IVUS-VH, a lipid-core plaque by near infrared (NIR) spectroscopy or a thin fibrous cap atheroma by optical coherence tomography (OCT). As the physical boundaries for both light and sound are different, these imaging technologies offer different advantages and limitations. Light-based technologies offer unparalleled high image resolution (OCT) or unparalleled high sensitivity and specificity for distinct plaque components (NIR spectroscopy), whereas conventional IVUS offers a much better tissue penetration. From a clinical perspective, both types of information are valuable. Ideally, this information should easily and in real time be available in the catheterization laboratory, consisting of co-registered datasets gained during a single catheter pullback. On this background, a combined NIR spectroscopy and IVUS catheter has recently been introduced for clinical use. The article discusses the potential and limitations of these different technologies. They may allow advanced coronary plaque diagnosis in a fast, accurate, reliable, user- and patient-friendly manner and, as such, can help to improve clinical practice today and therapeutic options in the future.

Deposition of antimicrobial coatings on microstereolithography-fabricated microneedles

Microneedles are small-scale needle-like projections that may be used for transdermal delivery of pharmacologic agents, including protein-containing and nucleic acid-containing agents. Commercial translation of polymeric microneedles would benefit from the use of facile and cost effective fabrication methods. In this study, visible light dynamic mask microstereolithography, a rapid prototyping technique that utilizes digital light projection for selective polymerization of a liquid resin, was used for fabrication of solid microneedle array structures out of an acrylate-based polymer. Pulsed laser deposition was used to deposit silver and zinc oxide coatings on the surfaces of the visible light dynamic mask microstereolithography-fabricated microneedle array structures. Agar diffusion studies were used to demonstrate the antimicrobial activity of the coated microneedle array structures. This study indicates that light-based technologies, including visible light dynamic mask microstereolithography and pulsed laser deposition, may be used to fabricate microneedles with antimicrobial properties for treatment of local skin infections.

Optical diagnostics in the oral cavity: an overview

As the emphasis shifts from damage mitigation to disease prevention or reversal of early disease in the oral cavity, the need for sensitive and accurate detection and diagnostic tools become more important. Many novel and emergent optical diagnostic modalities for the oral cavity are becoming available to clinicians with a variety of desirable attributes including: (i) non-invasiveness, (ii) absence of ionizing radiation, (iii) patient-friendliness, (iv) real-time information (v) repeatability, and (vi) high-resolution surface and subsurface images. In this article, the principles behind optical diagnostic approaches, their feasibility and applicability for imaging soft and hard tissues, and their potential usefulness as a tool in the diagnosis of oral mucosal lesions, dental pathologies, and other dental applications will be reviewed. The clinical applications of light-based imaging technologies in the oral cavity and of their derivative devices will be discussed to provide the reader with a comprehensive understanding of emergent diagnostic modalities.

A Review of Current Research in Light-Based Technologies for Treatment of Podiatric Infectious Disease States

Recently, there has been a resurgence of interest in potential phototherapy technologies for the local treatment of bacterial and fungal infection. Currently, onychomycosis is the principle disease that is the target of these phototherapies in podiatric medicine. Some of these technologies are currently undergoing in vitro and in vivo trials approved by institutional review boards. The three light-based technologies are ultraviolet light therapy, near infrared photo-inactivation therapy, and photothermal ablative antisepsis. Each of these technologies have markedly dissimilar mechanisms of action. In this review, each technology will be discussed from the perspectives of history, photobiology, individual mechanism of action, safety, and potential clinical efficacy, with data presented from published material. This review is intended to give podiatric physicians detailed information on state-of-the-art infectious disease phototherapy.

From chromoendoscopy to confocal microscopy: Recent developments in endoscopic imaging of the colon

Recent advances in optical physics and bioengineering have given rise to a wealth of novel technologies for gastrointestinal endoscopy, which may make possible the real-time detection of neoplasia in the colon. Conventional diagnostic endoscopy is limited to a gross view of gastrointestinal mucosa, but several new, light-based technologies allow a glimpse of the colon at the subcellular level. Currently, “optical biopsies” must still be correlated with pathologic biopsies to ensure accuracy. Soon, however, these modalities, alone or in combination, will provide accurate, real-time subcellular imaging and in vivo histopathologic diagnoses.