Biology subjects

Stampanoni, M.

Publications and source records attributed to Stampanoni, M..

6 recordsLinked to original sources

bioRxiv2026

The Effects of Physical Exercise on Osteocyte Lacunar Morphology and Orientation around Bioresorbable Implants

In this study, we used synchrotron radiation micro-computed tomography (SR-CT) to investigate the effect of early post-operative physical exercise at 2, 4, and 6 weeks on osteocyte lacunar distribution and morphology in a Sprague Dawley rat femoral defect model after implantation of a bioresorbable pin. Physical exercise has been shown to improve bone remodeling after fracture, but its effects on the lacuno-canalicular network in the presence of bioresorbable implants remain unclear. The structure of lacunae is linked to that of osteocytes, which play an important role in bone remodeling and adaptation to stress. We studied a large number of lacunae (around 670 000 per sample) in terms of their location, morphology, and orientation. We show that in newly formed bone, lacunae are larger and rounder with exercise, while in previously existing bone, lacunae are less oriented along the long bone axis when exercise is performed. In addition, close to the implant, lacunar density is higher with exercise in both newly formed bone and previously existing bone. These findings point to a higher degree of remodeling and a pronounced lacunar response to mechanical stimulation and may thus help clarify bone behavior with exercise around implants to better design post-surgical recovery treatments.

bioengineering↗

bioRxiv2025

Histology-guided 3D virtual staining of microCT-imaged lung tissue via deep learning

Histologically stained tissue sections are considered the gold standard for studying microscopic anatomy and diagnosing disease in clinical practice. However, the processes of sectioning and staining are laborious, and the overall method relies on two-dimensional (2D) analysis. In contrast, X-ray-based virtual histology offers the advantage of virtual sectioning while retaining the full three-dimensional (3D) volumetric representation of the tissue. Nevertheless, its grayscale nature has prevented it to be readily utilized by pathologists who are accustomed to conventional histological stains. In this work, we present a histology-guided enhancement platform that can integrate the 3D information provided by synchrotron radiation phase-contrast microCT with the rich visual features characteristic of histological stains. We introduce a multi-stage microCT-histology co-registration method combined with a virtual staining deep neural network and demonstrate successful virtual histological staining of microCT human and mouse lung tissue that closely resembles standard histology. We evaluate our strategy on multiple histological stains and apply it to identify 3D collagen-based remodeling of pulmonary arteries in patients with pulmonary hypertension. Overall, this innovative enhancement pipeline has the potential to aid in the incorporation of microCT into clinical practice, and advance non-destructive 3D pathology for improved diagnostic efficiency and accuracy.

pathology↗

bioRxiv2021

Micrometer-resolution reconstruction and analysis of whole mouse brain vasculature by synchrotron-based phase-contrast tomographic microscopy

Nervous tissue metabolism is mainly supported by the dense thread of blood vessels which mainly provides fast supplies of oxygen and glucose. Recently, the supplying role of the brain vascular system has been examined in major neurological conditions such as the Alzheimers and Parkinsons diseases. However, to date, fast and reliable methods for the fine level microstructural extraction of whole brain vascular systems are still unavailable. We present a methodological framework suitable for reconstruction of the whole mouse brain cerebral microvasculature by X-ray tomography with the unprecedented pixel size of 0.65 m. Our measurements suggest that the resolving power of the technique is better than in many previous studies, and therefore it allows for a refinement of current measurements of blood vessel properties. Relevant insights emerged from analyses characterizing the regional morphology and topology of blood vessels. Specifically, vascular diameter and density appeared non-homogeneously distributed among the brain regions suggesting preferential sites for high-demanding metabolic requirements. Also, topological features such as the vessel branching points were non-uniformly distributed among the brain districts indicating that specific architectural schemes are required to serve the distinct functional specialization of the nervous tissue. In conclusion, here we propose a combination of experimental and computational method for efficient and fast investigations of the vascular system of entire organs with submicrometric precision.

neuroscience↗

bioRxiv2020

Hierarchical imaging and computational analysis of three-dimensional vascular network architecture in the entire postnatal and adult mouse brain

The formation of new blood vessels and the establishment of vascular networks are crucial during brain development, in the adult healthy brain, as well as in various diseases of the central nervous system (CNS). Here, we describe a method that enables hierarchical imaging and computational analysis of vascular networks in postnatal- and adult mouse brains. Resin-based vascular corrosion casting, scanning electron microscopy, synchrotron radiation and desktop {micro}CT imaging, and computational network analysis are used. Combining these methods enables detailed visualization and quantification of the three-dimensional (3D) brain vasculature. Network features such as vascular volume fraction, branch point density, vessel diameter, - length, -tortuosity, and -directionality as well as extravascular distance can be obtained at any developmental stage from the early postnatal to the adult brain. Our method allows characterizing brain vascular networks separately for capillaries and non-capillaries. The entire protocol, from mouse perfusion to vessel network analysis, takes approximately 10 days. Online summaryThis protocol uses vascular corrosion casting, hierarchical synchrotron radiation {micro}CT imaging, and computational image analysis to assess the three-dimensional vascular network architecture.

neuroscience↗

bioRxiv2019

Chronic pain alters microvascular architectural organization of somatosensory cortex

Chronic pain (CP) represents a complex pathology profoundly involving both neural and glial compartments of the central nervous system. While most CP studies have also investigated the macroscopic brain vascular system, its microstructural architecture still remains largely unexplored. Further, the adaptive modifications of the vascular microstructure as consequence of diseases or pathological insults, did not receive adequate attention. Here we show microtomographic signs of diffuse and conspicuous microvascular neogenesis in somatosensory cortex of CP animal models already peaking at 15 days from the model instantiation. Progressive fading of this microvessel neogenesis then ensued in the next six months yet maintaining higher vascular density with a preserved small fraction of them. Due to the important consequences on the neuron-glial-vessel arrangements and on the resulting metabolic and functional disorders of the local networks, novel additional scenarios of CP are thus conceivable with profound consequences of potential future CP diagnostic and therapeutic appraisals.

neuroscience↗

bioRxiv2017

Targeting xCT-Mediated Glutamate Release Normalizes Tumor Angiogenesis In The Brain

Brain tumors are among the most malignant primary tumors, hallmarked by angiogenesis, neuronal destruction and brain swelling. Inhibition of the glutamate-cystein antiporter xCT (system xc-/SLC7A11) alleviates seizures, neuronal cell death and tumor-associated brain edema. Here we show enhanced tumor vessel growth and increased brain edema in xCT-expressing brain tumors. Furthermore, xCT-mediated glutamate impacts directly on endothelial cells in an N-methyl-D-aspartate receptor (NMDAR) dependent manner with intracellular Ca2+ release. Cerebral intravital microscopy revealed that xCT-driven tumor vessels are functional and display increased permeability. Endothelial-cell-specific NMDAR1 knockout mice (GRINi{Delta}EC) show suppressed endothelial sprouting and vascular density compared to control littermates. In addition, implanted gliomas in GRINi{Delta}EC mice display reduced tumor vessels in contrast to gliomas in wildtype animals. Moreover, therapeutic targeting of xCT in gliomas alleviates tumor angiogenesis to normalized levels comparable to controls. Our data reveal that xCT and its substrate glutamate specifically operate on endothelial cells and promote neoangiogenesis. Thus, targeting xCT expression and glutamate secretion in gliomas provides a novel therapeutic roadmap for normalizing tumor angiogenesis.

cell biology↗