Monitoring of optical properties of tumors during laser plasmon photothermal therapy.

We studied grafted tumors obtained by subcutaneous implantation of kidney cancer cells into male white rats. Gold nanorods with a plasmon resonance of about 800 nm were injected intratumorally for photothermal heating. Experimental irradiation of tumors was carried out percutaneously using a near-infrared diode laser. Changes in the optical properties of the studied tissues in the spectral range 350-2200 nm under plasmonic photothermal therapy (PPT) were studied. Analysis of the observed changes in the absorption bands of water and hemoglobin made it possible to estimate the depth of thermal damage to the tumor. A significant decrease in absorption peaks was observed in the spectrum of the upper peripheral part and especially the tumor capsule. The obtained changes in the optical properties of tissues under laser irradiation can be used to optimize laboratory and clinical PPT procedures.

Immersion optical clearing of adipose tissue in rats: ex vivo and in vivo studies.

Optical clearing (OC) of adipose tissue has not been studied enough, although it can be promising in medical applications, including surgery and cosmetology, for example, to visualize blood vessels or increase the permeability of tissues to laser beams. The main objective of this work is to develop technology for OC of abdominal adipose tissue in vivo using hyperosmotic optical clearing agents (OCAs). The maximum OC effect (77%) was observed for ex vivo rat adipose tissue samples exposed to OCA on fructose basis for 90 minutes. For in vivo studies, the maximum effect of OC (65%) was observed when using OCA based on diatrizoic acid and dimethylsulfoxide for 120 minutes. Histological analysis showed that in vivo application of OCAs may induce a limited local necrosis of fat cells. The efficiency of OC correlated with local tissue damage through cell necrosis due to accompanied cell lipolysis.

Photothermal and Photodynamic Therapy of Tumors with Plasmonic Nanoparticles: Challenges and Prospects.

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.

Systemic Administration of Polyelectrolyte Microcapsules: Where Do They Accumulate and When? In Vivo and Ex Vivo Study.

Multilayer capsules of 4 microns in size made of biodegradable polymers and iron oxide magnetite nanoparticles have been injected intravenously into rats. The time-dependent microcapsule distribution in organs was investigated in vivo by magnetic resonance imaging (MRI) and ex vivo by histological examination (HE), atomic absorption spectroscopy (AAS) and electron spin resonance (ESR), as these methods provide information at different stages of microcapsule degradation. The following organs were collected: Kidney, liver, lung, and spleen through 15 min, 1 h, 4 h, 24 h, 14 days, and 30 days after intravenous injections (IVIs) of microcapsules in a saline buffer at a dosage of 2.5 × 108 capsule per kg. The IVI of microcapsules resulted in reversible morphological changes in most of the examined inner organs (kidney, heart, liver, and spleen). The capsules lost their integrity due to degradation over 24 h, and some traces of iron oxide nanoparticles were seen at 7 days in spleen and liver structure. The morphological structure of the tissues was completely restored one month after IVI of microcapsules. Comprehensive analysis of the biodistribution and degradation of entire capsules and magnetite nanoparticles as their components gave us grounds to recommend these composite microcapsules as useful and safe tools for drug delivery applications.

Plasmonic photothermal therapy: Approaches to advanced strategy.

BACKGROUND: The analysis of recent studies on plasmonic photothermal therapy (PPT) after intravenous administration of gold nanorods (GNRs) has demonstrated that the effectiveness of nanoparticle-assisted laser hyperthermia depends on a correct dosage strategy of nanoparticle administration. Accumulation of GNRs in tumor tissue dramatically increases the local heating of the tumor without damage to healthy tissues. However, the optimal doses of GNR intravenous injections (IVIs) for effective accumulation in tumors, and optimal protocols of PPT are not designed yet. The current study aims to improve the efficacy of PPT in tumor-bearing rats using multiple fractional intravenous administration of GNRs. MATERIALS AND METHODS: For PPT experiments, the GNRs with aspect ratio of 4.1 were functionalized with thiolated polyethylene glycol (PEG) and their suspensions were used for multiple fractional intravenous administration in outbred albino male rats with experimental model of rat liver cancer (cholangiocarcinoma line PC-1). Doppler ultrasonography was performed to characterize the vascularity of transplanted rat tumors before any treatment. After a final injection of GNRs, tumor was irradiated during 15 minutes by 808-nm NIR diode laser at a power density 2.3 W/cm2 . The animals were withdrawn from the experiment and sampling of tissues for morphological study and gold accumulation was performed 24 hours and 3 weeks after PPT. RESULTS: The multiple IVIs of gold nanorods and further PPT of transplanted cholangiocarcinoma provided significant damage to tumor tissue resulting in pronounced necrotic mass and retardation of the tumor growth. More importantly, the proposed PPT protocol had low toxicity as evidenced by histological examination of internal organs. The efficiency of PPT depends on the presence of newly formed vasculature as revealed by the Doppler ultrasound investigation. CONCLUSION: The repeatable IVIs promote greater of GNR accumulation within the tumor thus resulting in higher PPT efficacy. Accompanying ultrasonography can be useful for prognosis and monitoring of treatment. Lasers Surg. Med. 50:1025-1033, 2018. © 2018 Wiley Periodicals, Inc.

Morphology alterations of skin and subcutaneous fat at NIR laser irradiation combined with delivery of encapsulated indocyanine green.

The goal of this study is to quantify the impact of the in vivo photochemical treatment of rats with obesity using indocyanine green (ICG) dissolved in saline or dispersed in an encapsulated form at NIR laser irradiation, which was monitored by tissue sampling and histochemistry. The subcutaneous injection of the ICG solution or ICG encapsulated into polyelectrolyte microcapsules, followed by diode laser irradiation (808 nm, 8 ?? W / cm 2 , 1 min), resulted in substantial differences in lipolysis of subcutaneous fat. Most of the morphology alterations occurred in response to the laser irradiation if a free-ICG solution had been injected. In such conditions, membrane disruption, stretching, and even delamination in some cases were observed for a number of cells. The encapsulated ICG aroused similar morphology changes but with weakly expressed adipocyte destruction under the laser irradiation. The Cochran Q test rendered the difference between the treatment alternatives statistically significant. By this means, laser treatment using the encapsulated form of ICG seems more promising and could be used for safe layerwise laser treatment of obesity and cellulite.

In vitro and in vivo MRI visualization of nanocomposite biodegradable microcapsules with tunable contrast.

Microcapsules, made of biodegradable polymers, containing magnetite nanoparticles with tunable contrast in both the T1 and T2 MRI modes, were successfully prepared using a layer-by-layer approach. The MRI contrast of the microcapsules was shown to depend on the distance between magnetite nanoparticles in the polymeric layers, which is controlled by their concentration in the microcapsule shell. A fivefold increase in the average distance between the nanoparticles in the microcapsule shell led to a change in the intensity of the MR signal of 100% for both the T1 and T2 modes. Enzyme treatment of biodegradable shells resulted in a change of the microcapsules' MRI contrast. In vivo degradation of nanocomposite microcapsules concentrated in the liver after intravenous injection was demonstrated by MRI. This method can be used for the creation of a new generation of drug delivery systems, including drug depot, with combined navigation, visualization and remote activated release of bioactive substances in vivo.

In vivo optical monitoring of transcutaneous delivery of calcium carbonate microcontainers.

We have developed a method for delivery of biocompatible CaCO3 microcontainers (4.0 ± 0.8 µm) containing Fe3O4 nanoparticles (14 ± 5 nm) into skin in vivo using fractional laser microablation (FLMA) provided by a pulsed Er:YAG laser system. Six laboratory rats have been used for the microcontainer delivery and weekly monitoring implemented using an optical coherence tomography and a standard histological analysis. The use of FLMA allowed for delivery of the microcontainers to the depth about 300 µm and creation of a depot in dermis. On the seventh day we have observed the dissolving of the microcontainers and the release of nanoparticles into dermis.

Transcutaneous delivery of micro- and nanoparticles with laser microporation.

Fractional laser ablation is one of the relatively safe and minimally invasive methods used to administer micro- and nanoparticles into the skin at sufficiently large depth. In this article, we present the results of delivery of TiO2 nanoparticles and Al2O3 microparticles into skin. Fractional laser microablation of skin was provided by a system based on a pulsed Er:YAG laser with the following parameters: the wavelength 2940 nm, the pulse energy 3.0 J, and the pulse duration 20 ms. Ex vivo and in vivo human skin was used in the study. The suspensions of titanium dioxide and alumina powder in polyethylene glycol with particle size of about 100 nm and 27 µm, respectively, were used. In the ex vivo experiments, reflectance spectra of skin samples with administered particles were measured and histological sections of the samples were made. In the in vivo experiment, reflectance spectroscopy, optical coherence tomography, and clinical photography were used to monitor the skin status during one month after suspension administering. It is shown that particles can be delivered into dermis up to the depth 230 µm and distributed uniformly in the tissue. Spectral measurements confirm that the particles stay in the dermis longer than 1 month.

Fat tissue histological study at indocyanine green-mediated photothermal/photodynamic treatment of the skin in vivo.

Histological slices of skin samples with the subcutaneous adipose tissue after photothermal/photodynamic treatment are analyzed. In the case of subcutaneous indocyanine green injection and 808-nm diode laser exposure of the rat skin site in vivo, the greatest changes in tissue condition were observed. Processes were characterized by dystrophy, necrosis, and desquamation of the epithelial cells, swelling and necrosis of the connective tissue, and widespread necrosis of the subcutaneous adipose tissue. The obtained data are useful for safe layer-by-layer dosimetry of laser illumination of ICG-stained adipose tissue for treatment of obesity and cellulite.

A 3-year-old boy with ovotestes: gender reassignment and surgical management.

OBJECTIVE: We report a male patient with ovotesticular disorder of sex development (OTDSD), resulting from structurally abnormal Y chromosome. CASE REPORT: A 3-year-old boy was admitted to the Surgical Pediatric Department for masculinizing reconstruction. He had a clitorophallus, bifid scrotum, perineal hypospadias and bilateral impalpable gonads. Pelvic ultrasound and laparoscopy showed a uterus and two gonads with primary ovarian follicles. Chromosome analysis detected a mos 47,XX,mar/46,XX karyotype. Complex genetic evaluation revealed that the marker was Yp isochromosome. Surgical care included a feminizing genitoplasty and separation of the gonads with total excision of testicular tissue. CONCLUSIONS: The presented case emphasizes the importance of a systematic approach to the investigation and management of the patients with ovotesticular DSD. It also raises the important issue about gender reassignment in intersex individuals in mid-childhood.

Laser-induced tissue hyperthermia mediated by gold nanoparticles: toward cancer phototherapy.

We describe an application of plasmonic silica/gold nanoshells to produce a controllable laser hyperthermia in tissues with the aim of the enhancement of cancer photothermal therapy. Laser irradiation parameters are optimized on the basis of preliminary experimental studies using a test-tube phantom and laboratory rats. Temperature distributions on the animal skin surface at hypodermic and intramuscular injection of gold nanoparticle suspensions and affectations by the laser radiation are measured in vivo with a thermal imaging system. The results of temperature measurements are compared with tissue histology.

Circulation and distribution of gold nanoparticles and induced alterations of tissue morphology at intravenous particle delivery.

Kinetics, biodistribution, and histological studies were performed to evaluate the particle-size effects on the distribution of 15 nm and 50 nm PEG-coated colloidal gold (CG) particles and 160 nm silica/gold nanoshells (NSs) in rats and rabbits. The above nanoparticles (NPs) were used as a model because of their importance for current biomedical applications such as photothermal therapy, optical coherence tomography, and resonance-scattering imaging. The dynamics of NPs circulation in vivo was evaluated after intravenous administration of 15 nm CG NPs to rabbit, and the maximal concentrations of gold were observed 15-30 min after injection. Rats were injected in the tail vein with PEG-coated NPs (about 0.3 mg Au/kg rats). 24 h after injection, the accumulation of gold in different organs and blood was determined by atomic absorption spectroscopy. In accordance with the published reports, we observed 15 nm particles in all organs with rather smooth distribution over liver, spleen and blood. By contrast, the larger NSs were accumulated mainly in the liver and spleen. For rabbits, the biodistribution was similar (72 h after intravenous injection). We report also preliminary data on the light microscopy and TEM histological examination that allows evaluation of the changes in biotissues after gold NPs treatment.