Optical parameters of healthy and tumor breast tissues in mice.

Knowledge of the optical parameters of tumors is important for choosing the correct laser treatment parameters. In this paper, optical properties and refraction indices of breast tissue in healthy mice and a 4T1 model mimicking human breast cancer have been measured. A significant decrease in both the scattering and refractive index of tumor tissue has been observed. The change in tissue morphology has induced the change in the slope of the scattering spectrum. Thus, the light penetration depth into tumor has increased by almost 1.5-2 times in the near infrared "optical windows." Raman spectra have shown lower lipid content and higher protein content in tumor. The difference in the optical parameters of the tissues under study makes it possible to reliably differentiate them. The results may be useful for modeling the distribution of laser radiation in healthy tissues and cancers for deriving optimal irradiation conditions in photodynamic therapy.

Biodegradable calcium carbonate carriers for the topical delivery of clobetasol propionate.

Inflammatory dermatoses represent a global problem with increasing prevalence and recurrence among the world population. Topical glucocorticoids (GCs) are the most commonly used anti-inflammatory drugs in dermatology due to a wide range of their therapeutic actions, which, however, have numerous local and systemic side effects. Hence, there is a growing need to create new delivery systems for GCs, ensuring the drug localization in the pathological site, thus increasing the effectiveness of therapy and lowering the risk of side effects. Here, we propose a novel topical particulate formulation for the GC clobetasol propionate (CP), based on the use of porous calcium carbonate (CaCO3) carriers in the vaterite crystalline form. The designed carriers contain a substantially higher CP amount than conventional dosage forms used in clinics (4.5% w/w vs. 0.05% w/w) and displayed a good biocompatibility and effective cellular uptake when studied in fibroblasts in vitro. Hair follicles represent an important reservoir for the GC accumulation in skin and house the targets for its action. In this study, we demonstrated successful delivery of the CP-loaded carriers (CP-CaCO3) into the hair follicles of rats in vivo using optical coherent tomography (OCT). Importantly, the OCT monitoring revealed the gradual intrafollicular degradation of the carriers within 168 h with the most abundant follicle filling occurring within the first 48 h. Biodegradability makes the proposed system especially promising when searching for new CP formulations with improved safety and release profile. Our findings evidenced the great potential of the CaCO3 carriers in improving the dermal bioavailability of this poorly water-soluble GC.

Multimodal Method for Differentiating Various Clinical Forms of Basal Cell Carcinoma and Benign Neoplasms In Vivo.

Correct classification of skin lesions is a key step in skin cancer screening, which requires high accuracy and interpretability. This paper proposes a multimodal method for differentiating various clinical forms of basal cell carcinoma and benign neoplasms that includes machine learning. This study was conducted on 37 neoplasms, including benign neoplasms and five different clinical forms of basal cell carcinoma. The proposed multimodal screening method combines diffuse reflectance spectroscopy, optical coherence tomography and high-frequency ultrasound. Using diffuse reflectance spectroscopy, the coefficients of melanin pigmentation, erythema, hemoglobin content, and the slope coefficient of diffuse reflectance spectroscopy in the wavelength range 650-800 nm were determined. Statistical texture analysis of optical coherence tomography images was used to calculate first- and second-order statistical parameters. The analysis of ultrasound images assessed the shape of the tumor according to parameters such as area, perimeter, roundness and other characteristics. Based on the calculated parameters, a machine learning algorithm was developed to differentiate the various clinical forms of basal cell carcinoma. The proposed algorithm for classifying various forms of basal cell carcinoma and benign neoplasms provided a sensitivity of 70.6 ± 17.3%, specificity of 95.9 ± 2.5%, precision of 72.6 ± 14.2%, F1 score of 71.5 ± 15.6% and mean intersection over union of 57.6 ± 20.1%. Moreover, for differentiating basal cell carcinoma and benign neoplasms without taking into account the clinical form, the method achieved a sensitivity of 89.1 ± 8.0%, specificity of 95.1 ± 0.7%, F1 score of 89.3 ± 3.4% and mean intersection over union of 82.6 ± 10.8%.

Rapid Ultrasound Optical Clearing of Human Light and Dark Skin.

Application of optical clearing of biological tissue in humans in vivo is challenging due to toxicity of chemical agents, long processing time (≥30 min), and moderate (1.3-1.5-fold) imaging depth improvement. Here, we introduce novel, robust, and rapid ultrasound-based optical clearing of human skin without chemical agents that provides dramatic (up to 10-fold) reducing processing time down to 2-5 min. We discovered that ultrasound alone can increase a light depth penetration for optical coherence tomography (OCT) up to ~1.5-fold during 2 min. Nevertheless, sequent application of microdermabrasion, oleic acid and ultrasound allowed increasing OCT signal amplitude up to 3.3-fold with more than twice improved depth penetration during 30 min that was not demonstrated with other approaches. Comparison of these effects in light and dark skin revealed similarity of the optical clearing mechanisms. However, for combined optical clearing, only 1.34-fold increase in OCT signal amplitude was achieved for dark skin.