Photoacoustically-guided photothermal killing of mosquitoes targeted by nanoparticles

Label-free photothermal disruption of cytotoxic aggregates rescues pathology in a C. elegans model of Huntington's disease

Aggregation of proteins is a prominent hallmark of virtually all neurodegenerative disorders including Alzheimer’s, Parkinson’s and Huntington’s diseases. Little progress has been made in their treatment to slow or prevent the formation of aggregates by post-translational modification and regulation of cellular responses to misfolded proteins. Here, we introduce a label-free, laser-based photothermal treatment of polyglutamine (polyQ) aggregates in a C. elegans nematode model of huntingtin-like polyQ aggregation. As a proof of principle, we demonstrated that nanosecond laser pulse-induced local photothermal heating can directly disrupt the aggregates so as to delay their accumulation, maintain motility, and extend the lifespan of treated nematodes. These beneficial effects were validated by confocal photothermal, fluorescence, and video imaging. The results obtained demonstrate that our theranostics platform, integrating photothermal therapy without drugs or other chemicals, combined with advanced imaging to monitor photothermal ablation of aggregates, initiates systemic recovery and thus validates the concept of aggregate-disruption treatments for neurodegenerative diseases in humans.

Gold nanoparticles to enhance ophthalmic imaging

The use of gold nanoparticles as diagnostic tools is burgeoning, especially in the cancer community with a focus on theranostic applications to both cancer diagnosis and treatment. Gold nanoparticles have also demonstrated great potential for use in diagnostic and therapeutic approaches in ophthalmology. Although many ophthalmic imaging modalities are available, there is still a considerable unmet need, in particular for ophthalmic molecular imaging for the early detection of eye disease before morphological changes are more grossly visible. An understanding of how gold nanoparticles are leveraged in other fields could inform new ways they could be utilized in ophthalmology. In this paper, we review current ophthalmic imaging techniques and then identify optical coherence tomography (OCT) and photoacoustic imaging (PAI) as the most promising technologies amenable to the use of gold nanoparticles for molecular imaging. Within this context, the development of gold nanoparticles as OCT and PAI contrast agents are reviewed, with the most recent developments described in detail.

Relative larvicidal property of common oxide nanostructures against Culex quinquefasciatus

Common oxide nanostructures such as silicon-di-oxide, magnesium-oxide, zinc-oxide, and copper-oxide (CuO) having useful functional and bioactive properties have been synthesised and characterised. All these nanostructures have been found to be larvicidal towards Culex quinquefasciatus mosquito especially against lower instars in comparison with higher instars in 48 h. Only, CuO is larvicidal against late instar stages after 48 h. Moreover, CuO is larvicidal against first instar stages after 24 h (LC₅₀ 157 mg/l). However, none of these nanostructures are pupicidal. Post mortality larval morphology was found to be distorted under bright field microscopy and scanning electron microscopy images of affected larval surface appeared to be rough and uneven. Fluorescent images showed that nanostructures infiltrated inside visceral organs of larvae. Nanostructures also caused tissue oxidative stress in larvae. These results indicate that above stated oxide nanostructures are effective larvicidal agents against early instar stages of Culex larvae.

Modern trends in biophotonics for clinical diagnosis and therapy to solve unmet clinical needs

This contribution covers recent original research papers in the biophotonics field. The content is organized into main techniques such as multiphoton microscopy, Raman spectroscopy, infrared spectroscopy, optical coherence tomography and photoacoustic tomography, and their applications in the context of fluid, cell, tissue and skin diagnostics. Special attention is paid to vascular and blood flow diagnostics, photothermal and photodynamic therapy, tissue therapy, cell characterization, and biosensors for biomarker detection.