Three-dimensional (3D) cell cultures represent fundamental tools for the comprehension of cellular phenomena both in normal and in pathological conditions. In particular, mechanical and chemical stimuli play a relevant role on cell fate, cancer onset and malignant evolution. Here, we use mechanically-tuned alginate hydrogels to study the role of substrate elasticity on breast adenocarcinoma cell activity. The hydrogel elastic modulus (E) was measured via atomic force microscopy (AFM) and a remarkable range (150–4000 kPa) was obtained. A breast cancer cell line, MCF-7, was seeded within the 3D gels, on standard Petri and alginate-coated dishes (2D controls). Cells showed dramatic morphological differences when cultured in 3D versus 2D, exhibiting a flat shape in both 2D conditions, while maintaining a circular, spheroid-organized (cluster) conformation within the gels, similar to those in vivo. Moreover, we observed a strict correlation between cell viability and substrate elasticity; in particular, the number of MCF-7 cells decreased constantly with increasing hydrogel elasticity. Remarkably, the highest cellular proliferation rate, associated with the formation of cell clusters, occurred at two weeks only in the softest hydrogels (E = 150–200 kPa), highlighting the need to adopt more realistic and a priori defined models for in vitro cancer studies.

Skin mechanical properties are usually measured considering the entire skin thickness and very little is known about the mechanical behaviour of individual skin layers. We propose atomic force microscopy (AFM) as a tool to quantify nanoscale changes in the biomechanical properties and ultrastructure of human papillary dermis exposed to different mechanical and physical stimuli. Samples from 3 human skin biopsies were studied: one stretched by obesity, one subjected to a high level of sun exposure and normal skin as control. Slices of the papillary dermis layer were harvested at controlled depths from each skin biopsy and 25 μm areas of each slice were imaged and D-periodicity of collagen fibres measured by AFM, together with their stiffness. Standard histological analysis was also carried out to correlate biochemical properties and their distribution with stiffness and topography. We obtained similar stiffness values between the sample affected by obesity and the control sample at any depth level into the dermis, while the sun-exposed sample presented a significantly lower stiffness. Additionally, all samples presented an increase in the stiffness at higher depths into the papillary dermis layer. Collagen fibres close to the epidermis of sample affected either by obesity and sun exposure-the former even more than the latter-are thicker and present a larger D-period than those in the control sample. Our results open the possibility to use structural and mechanical analysis based on AFM as a complementary tool for medical diagnosis and therapy monitoring.

No abstract

No abstract

No abstract

Malignancy diagnosis of uterine smooth muscle neoplasms can be challenging. Morphologic features are subjective, and the utility of immunohistochemistry is still debated. 1,2 We propose to characterize and compare the ultrastructural and mechanical properties of leiomyoma and leiomyosarcoma with those of normal myometrium, using atomic force microscopy (AFM) technique. STUDY DESIGN: Three representative groups of samples were selected from the database of the Pathology UniteSan Martino Hospital, Genoa, Italy. Group 1 comprised 1 sample of normal myometrium and 1 sample of spindle cells leiomyoma from a 39-year-old patient and 1 sample of spindle cells leiomyosarcoma from a 62-year-old patient. Group 2 comprised 1 sample of normal myometrium and 1 sample of spindle cells leiomyoma from a 49-year-old patient and 1 sample of spindle cells leiomyosarcoma from a 67-year-old patient. Group 3 comprised 1 sample of normal myometrium and 1 sample of spindle cells leiomyoma from a 50-year-old patient and 1 sample of spindle cells leiomyosarcoma from a 55-year-old patient. Two shadowed sections (thickness of 5 mm for AFMimaging and 15 mm for AFM-indentation testing) were

No abstract

Introduction: The use of frozen section analysis is of considerable importance for the diagnosis of borderline ovarian tumors (BOTs) and to plan the most appropriate surgical management. The aim of this study is to determine the accuracy of frozen section in diagnosing BOTs.