Cancer remains one of the leading causes of death in the world. For a number of neoplasms, the efficiency of conventional chemo- and radiation therapies is insufficient because of drug resistance and marked toxicity. Plasmonic photothermal therapy (PPT) using local hyperthermia induced by gold nanoparticles (AuNPs) has recently been extensively explored in tumor treatment. However, despite attractive promises, the current PPT status is limited by laboratory experiments, academic papers, and only a few preclinical studies. Unfortunately, most nanoformulations still share a similar fate: great laboratory promises and fair preclinical trials. This review discusses the current challenges and prospects of plasmonic nanomedicine based on PPT and photodynamic therapy (PDT). We start with consideration of the fundamental principles underlying plasmonic properties of AuNPs to tune their plasmon resonance for the desired NIR-I, NIR-2, and SWIR optical windows. The basic principles for simulation of optical cross-sections and plasmonic heating under CW and pulsed irradiation are discussed. Then, we consider the state-of-the-art methods for wet chemical synthesis of the most popular PPPT AuNPs such as silica/gold nanoshells, Au nanostars, nanorods, and nanocages. The photothermal efficiencies of these nanoparticles are compared, and their applications to current nanomedicine are shortly discussed. In a separate section, we discuss the fabrication of gold and other nanoparticles by the pulsed laser ablation in liquid method. The second part of the review is devoted to our recent experimental results on laser-activated interaction of AuNPs with tumor and healthy tissues and current achievements of other research groups in this application area. The unresolved issues of PPT are the significant accumulation of AuNPs in the organs of the mononuclear phagocyte system, causing potential toxic effects of nanoparticles, and the possibility of tumor recurrence due to the presence of survived tumor cells. The prospective ways of solving these problems are discussed, including developing combined antitumor therapy based on combined PPT and PDT. In the conclusion section, we summarize the most urgent needs of current PPT-based nanomedicine.

Intraventricular hemorrhage is one of the most fatal forms of brain injury that is a common complication of premature infants. However, the therapy of this type of hemorrhage is limited, and new strategies are needed to reduce hematoma expansion. Here we show that the meningeal lymphatics is a pathway to remove red blood cells from the brain’s ventricular system of male human, adult and newborn rodents and is a target for non-invasive transcranial near infrared photobiomodulation. Our results uncover the clinical significance of phototherapy of intraventricular hemorrhage in 4-day old male rat pups that have the brain similar to a preterm human brain. The course of phototherapy in newborn rats provides fast recovery after intraventricular hemorrhage due to photo-improvements of lymphatic drainage and clearing functions. These findings shed light on the mechanisms of phototherapy of intraventricular hemorrhage that can be a clinically relevant technology for treatment of neonatal intracerebral bleedings.

In this paper, measurements of the optical properties (diffuse reflectance, total and collimated transmittance) of brain tissues in healthy rats and rats with C6-glioma were performed in the spectral range from 350 to 1800 nm. Using these measurements, characteristic tissue optical parameters, such as absorption coefficient, scattering coefficient, reduced scattering coefficient, and scattering anisotropy factor were reconstructed. It was obtained that the 10-day development of glioma led to increase of absorption coefficient, which was associated with the water content elevation in the tumor. However, further development of the tumor (formation of the necrotic core) led to decrease in the water content. The dependence of the scattering properties on the different stages of model glioma development was more complex. Light penetration depth into the healthy and tumor brain was evaluated.

The deposition of amyloid-β (Aβ) in the brain is a risk factor for Alzheimer’s disease (AD). Therefore, new strategies for the stimulation of Aβ clearance from the brain can be useful in preventing AD. Transcranial photostimulation (PS) is considered a promising method for AD therapy. In our previous studies, we clearly demonstrated the PS-mediated stimulation of lymphatic clearing functions, including Aβ removal from the brain. There is increasing evidence that sleep plays an important role in Aβ clearance. Here, we tested our hypothesis that PS at night can stimulate Aβ clearance from the brain more effectively than PS during the day. Our results on healthy mice show that Aβ clearance from the brain occurs faster at night than during wakefulness. The PS course at night improves memory and reduces Aβ accumulation in the brain of AD mice more effectively than the PS course during the day. Our results suggest that night PS is a more promising candidate as an effective method in preventing AD than daytime PS. These data are an important informative platform for the development of new noninvasive and nonpharmacological technologies for AD therapy as well as for preventing Aβ accumulation in the brain of people with disorder of Aβ metabolism, sleep deficit, elderly age, and jet lag.

The meningeal lymphatic system that was recently discovered is a network of optically transparent vessels that play a vital role in the health of the central nervous system (CNS) in protecting the brain against pathogens.^{1 – 3} In 2015, Louveau et al.¹ and Aspelund et al.² clearly showed that the meningeal lymphatic system is involved in the clearing of waste products from the brain.