Layer-by-Layer Investigation of Ultrastructures and Biomechanics of Human Cornea.

The cornea is an avascular, innervated, and transparent tissue composed of five layers: the epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. It is located in the outermost fraction of the eyeball and is responsible for the refraction of two-thirds of light and protection from external mechanical damage. Although several studies have been done on the cornea on the macroscopic scale, there is a lack of studies on the micro-nanoscopic scale, especially an analysis evaluating the cornea layer by layer. In this study, atomic force microscopy (AFM) was employed to assess four layers that form the cornea, analyzing: adhesion, stiffness, and roughness. The results showed microvilli in the epithelial and endothelial layers, pores in the basement membrane, and collagen fibers in the Stroma. These data increase the knowledge about the human cornea layers' ultrastructures and adds new information about its biophysical properties.

Diabetes and Cognitive Decline: An Innovative Approach to Analyzing the Biophysical and Vibrational Properties of the Hippocampus.

Diabetes Mellitus (DM) is a disease characterized by high blood glucose levels, known as hyperglycemia. Diabetes represents a risk factor for the development of neurodegenerative diseases, such as Alzheimer's Disease (AD), one of the most prevalent neurodegenerative diseases worldwide, which leads to progressive mental, behavioral, and functional decline, affecting many brain structures, especially the hippocampus. Here, we aim to characterize the ultrastructural, nanomechanical, and vibrational changes in hyperglycemic hippocampal tissue using atomic force microscopy (AFM) and Raman spectroscopy. DM was induced in rats by streptozotocin injection (type 1) or dietary intervention (type 2). Cryosections of the hippocampus were prepared and analyzed on an MM8 AFM (Bruker) in Peak Force Quantitative Nanomechanics mode, performing 25 µm2 scans in 9 regions of 3 samples from each group. Ultrastructural and nanomechanical data such as surface roughness, area, volume, Young's modulus, and adhesion were evaluated. The hippocampal samples were also analyzed on a T64000 Spectrometer (Horiba), using a laser λ = 632.8 nm, and for each sample, four spectra were obtained in different regions. AFM analyses show changes on the ultrastructural scale since diabetic animals had hippocampal tissue with greater roughness and volume. Meanwhile, diabetic tissues had decreased adhesion and Young's modulus compared to control tissues. These were corroboratedby Raman data that shows changes in the molecular composition of diabetic tissues. The individual spectra show that the most significant changes are in the amide, cholesterol, and lipid bands. Overall, the data presented here show that hyperglycemia induces biophysical alterations in the hippocampal tissue of diabetic rats, providing novel biophysical and vibrational cues on the relationship between hyperglycemia and dementia.

[223Ra] RaCl2 nanomicelles showed potent effect against osteosarcoma: targeted alpha therapy in the nanotechnology era.

The treatment of bone metastatsis as primary bone cancer itself is still a challenge. The use od radium dichloride ([223Ra] RaCl2) has emerged in the last few years as one of the best treatment choice for bone cancer, with especial focus in bone metastasis. The alpha-emitter radiopharmaceutical has showed potent and efficient results in several clinical trials. In this study we have formulated radium dichloride ([223Ra] RaCl2) nanomicelles in order to evaluate and compare with pure radium dichloride ([223Ra] RaCl2). The results showed that nanomicelles at the same dose had a superior effect (20% higher efficient) when compared with pure radium dichloride ([223Ra] RaCl2). The results corroborated the effectiveness of the nanosystem validating the application of nanotechnology in alpha-radiotherapy with radium dichloride ([223Ra] RaCl2).