Search

Marta Truffi,1 Marta Sevieri,2 Lucia Morelli,3 Matteo Monieri,2 Serena Mazzucchelli,2 Luca Sorrentino,2 Raffaele Allevi,2 Arianna Bonizzi,2 Pietro Zerbi,2 Beatrice Marchini,2 Erika Longhi,2 Gianluca Matteo Sampietro,4 Francesco Colombo,4 Davide Prosperi,3 Miriam Colombo,3 Fabio Corsi2,5 1Nanomedicine and Molecular Imaging Laboratory, Istituti Clinici Scientifici Maugeri IRCCS, Pavia 27100, Italy; 2Department of Biomedical and Clinical Sciences “Luigi Sacco, Università degli studi di Milano, Milano, 20157, Italy; 3NanoBioLab, Department of Biotechnology and Biosciences, Università degli studi di Milano-Bicocca, Milano, 20126, Italy; 4IBD Surgery Unit, ASST Fatebenefratelli Sacco - Ospedale “Luigi Sacco” Polo Universitario, Milano, 20157, Italy; 5Surgery Department, Breast Unit, Istituti Clinici Scientifici Maugeri IRCCS, Pavia, 27100, ItalyCorrespondence: Fabio CorsiSurgery Department, Breast Unit, Istituti Clinici Scientifici Maugeri IRCCS, via Maugeri 4, Pavia 27100, ItalyTel +39 02 5031 9850Fax +39 02 5031 9846Email fabio.corsi@icsmaugeri.itPurpose: Assessment of inflammatory bowel disease (IBD) currently relies on aspecific clinical signs of bowel inflammation. Specific imaging of the diseased bowel regions is still lacking. Here, we investigate mucosal addressin cell adhesion molecule 1 (MAdCAM-1) as a reliable and specific endothelial target for engineered nanoparticles delivering imaging agents to obtain an exact mapping of diseased bowel foci.Materials and Methods: We generated a nanodevice composed of PLGA-PEG coupled with anti-MAdCAM-1 antibody half-chains and loaded with quantum dots (P@QD-MdC NPs). Bowel localization and systemic biodistribution of the nanoconjugate were analyzed upon injection in a murine model of chronic IBD obtained through repeated administration of dextran sulfate sodium salt. Specificity for diseased bowel regions was also assessed ex vivo in human specimens from patients with IBD. Potential for development as contrast agent in magnetic resonance imaging was assessed by preliminary study on animal model.Results: Synthesized nanoparticles revealed good stability and monodispersity. Molecular targeting properties were analyzed in vitro in a cell culture model. Upon intravenous injection, P@QD-MdC NPs were localized in the bowel of colitic mice, with enhanced accumulation at 24 h post-injection compared to untargeted nanoparticles (p< 0.05). Nanoparticles injection did not induce histologic lesions in non-target organs. Ex vivo exposure of human bowel specimens to P@QD-MdC NPs revealed specific recognition of the diseased regions vs uninvolved tracts (p< 0.0001). After loading with appropriate contrast agent, the nanoparticles enabled localized contrast enhancement of bowel mucosa in the rectum of treated mice.Conclusion: P@QD-MdC NPs efficiently detected bowel inflammation foci, accurately following the expression pattern of MAdCAM-1. Fine-tuning of this nanoconjugate with appropriate imaging agents offers a promising non-invasive tool for specific IBD diagnosis.Keywords: polymeric nanoparticles, inflamed bowel, adhesion molecule, targeted imaging

Background Clinical experience highlights the wide heterogeneity of primary prostate cancer (PPCa), even when potentially related to the same grade and stage. Currently available prediction tools and biomarkers do not always allow for early recognition of PPCa aggressive phenotype, sometimes making it impossible to distinguish among men harbouring indolent tumours or life-threatening disease. Objective To establish a novel ex vivo/in vitro model suitable to estimate the invasive phenotype of PPCa cells (PPCaC). Design, setting, and participants The ability of PPCaC to infiltrate the prostate extracellular matrix (ECM) was used as an index of invasion. ECM was obtained by decellularising 24 NT-prostate specimens from radical prostatectomy. PPCaC were obtained from six tumours with different Gleason patterns and pathological stages. Invasion ability was estimated in direct-cocolture experiments. Outcome measurements and statistical analysis The extent of ECM invasion by PPCaC was quantified by counting the number of infiltrated cells. Mann–Whitney test was utilised for statistical comparisons. Results and limitations Samples of ECM resulted to be free of cells and DNA and with a preserved three-dimensional structure and stromal protein content. The system resulted to be reliable since well characterised normal-, benign-, and malignant-prostate cell lines either re-epitheliased or invaded the matrices, according to their specific nature. Similarly, PPCaC invaded the ECMs consistently with their stage and biochemical recurrence. Of notice, this model was able to identify a different invasive phenotype even among tumours with equal Gleason patterns and pathological stages. The small sample size represents a limitation. Conclusions We developed an ex vivo/in vitro model able to reproduce the original PPCa-microenvironment and suitable to recognise the inherent invasive behaviour of PPCaC. Patient summary We developed a novel ex vivo/in vitro system which enables us to uncover which prostate tumours host potentially aggressive cancer cells. The identification of cancer cells with different invasive abilities will likely lead to the identification of new biomarkers to safely predict disease progression.

In the fields of biomaterials and tissue engineering simulating the native microenvironment is of utmost importance. As a major component of the microenvironment, the extracellular matrix (ECM) contributes to tissue homeostasis, whereas modifications of native features are associated with pathological conditions. Furthermore, three-dimensional (3D) geometry is an important feature of synthetic scaffolds favoring cell stemness, maintenance and differentiation. We analyzed the 3D structure, geometrical measurements and anisotropy of the ECM isolated from (i) human bladder mucosa (basal lamina and lamina propria) and muscularis propria; and, (ii) bladder carcinoma (BC). Next, binding and invasion of bladder metastatic cell line was observed on synthetic scaffold recapitulating anisotropy of tumoral ECM, but not on scaffold with disorganized texture typical of non-neoplastic lamina propria. This study provided information regarding the ultrastructure and geometry of healthy human bladder and BC ECMs. Likewise, using synthetic scaffolds we identified linearization of the texture as a mandatory feature for BC cell invasion. Integrating microstructure and geometry with biochemical and mechanical factors could support the development of an innovative synthetic bladder substitute or a tumoral scaffold predictive of chemotherapy outcomes.

The extracellular matrix (ECM) from perilesional and colorectal carcinoma (CRC), but not healthy colon, sustains proliferation and invasion of tumor cells. We investigated the biochemical and physical diversity of ECM in pair-wised comparisons of healthy, perilesional and CRC specimens. Progressive linearization and degree of organization of fibrils was observed from healthy to perilesional and CRC ECM and was associated with a steady increase of stiffness and collagen crosslinking. In the perilesional ECM these modifications coincided with increased vascularization, whereas in the neoplastic ECM they were associated with altered modulation of matrisome proteins, increased content of hydroxylated lysine and lysyl oxidase. This study identifies the increased stiffness and crosslinking of the perilesional ECM predisposing an environment suitable for CRC invasion as a phenomenon associated with vascularization. The increased stiffness of colon areas may represent a new predictive marker of desmoplastic region predisposing to invasion, thus offering new potential application for monitoring adenoma with invasive potential.