RESUMEN
Reconstructing the microscale villous organisation and functionality of the small intestine is essential for developing in vitro platforms tailored for absorption studies as well as for investigating intestinal morphogenesis in development and disease. However, the current fabrication techniques able to mimic the villus-crypt axis poses significant challenges in terms of reconstruction of the complex 3D microarchitecture. These challenges extend beyond mere structural intricacies to encompass the incorporation of diverse cell types and the management of intricate fluid dynamics within the system. Here, we introduce a novel microfluidic device called In-Crypts, which integrates a cell-instructive membrane aimed at inducing and guiding Caco-2 cells morphogenesis. Patterned topographical cues embossed onto the porous membrane induce the formation of a well-organized intestinal epithelium, characterized by proliferating crypt-like domains and differentiated villus-like regions. Notably, our cell-instructive porous membrane effectively sustains stem cells development, faithfully replicating the niche environment of in vivo intestinal crypts thus mirroring the cell biogeography observed in vivo. Moreover, by introducing dynamic fluid flow, we provide a faithful recapitulation of the native microenvironmental shear stress experienced by the intestinal epithelium. This stress plays a crucial role in influencing cell behaviour, differentiation, and overall functionality, thus offering a highly realistic model for studying intestinal physiology and pathology. The resulting intestinal epithelium exhibits significantly denser regions of mucus and microvilli, characteristic typically absent in static cultures, upregulating more than 1.5 of the amount expressed in the classical flattened configuration, enhanced epithelial cell differentiation and increased adsorptive surface area. Hence, the innovative design of In-Crypts proves the critical role of employing a cell-instructive membrane in argument the physiological relevance of organs-on-chips. This aspect, among others, will contribute to a more comprehensive understanding of organism function, directly impacting drug discovery and development. .
RESUMEN
(1) Background: Previous studies showed left ventricular (LV) and left atrial (LA) improvement and reverse remodeling after therapy with Sacubitril/Valsartan (S/V) in patients affected by heart failure with reduced ejection fraction (HFrEF). Therefore, we sought to investigate predictors of LA structural and functional reverse remodeling (LARR) in this setting of patients after therapy with S/V, focusing on left atrial strain parameters, such as peak atrial longitudinal strain (PALS). (2) Methods: Patients with HFrEF underwent clinical and echocardiographic evaluation at baseline and after six months of therapy with S/V. Measures of LA structure (LA volume index, LAVi) and function (LA emptying fraction (LAEF), PALS, LA conduit strain and peak atrial contraction strain (PACS) were also analyzed. Patients were divided in two groups, those with a LARR (relative reduction in LAVi > 15%, LARR+) and those without (LARR-). (3) Results: A total of 47 consecutive patients (66 ± 8 years, 85% male, mean LVEF 28 ± 6%) were enrolled in the study and followed up. A significant increase of LAEF (46 ± 13 vs. 37 ± 11%, p < 0.001) and a significant reduction of LAVi (42 ± 15 vs. 45 ± 15 mL/m2, p = 0.008) were found after 6 months of S/V therapy; 47% of the population showed LA reverse remodeling. LA strain parameters, PALS (19 ± 8 vs. 15 ± 7 %, p < 0.001) and LA conduit (-9.7 ± 5.2% vs. -7.6 ± 4.1%, p = 0.007) significantly improved after 6 months of S/V therapy. At multivariable stepwise regression analysis, changes in LV End Diastolic Volume (LVEDV) and PALS were significantly proportional to changes in LAVi values. (4) Conclusions: Six months of treatment with S/V in patients with HFrEF was associated with an improvement in LA functional reverse remodeling in a real-world scenario. LARR was not significantly correlated to baseline echocardiographic variables, but was proportional to changes in LV volumes and LA strain parameters. Finally, after S/V therapy, a strict connection between LA and LV reverse remodeling and between LA anatomical and functional reverse remodeling seems to be outlined.
RESUMEN
BACKGROUND: Observational studies have demonstrated that treatment with sacubitril/valsartan may improve left ventricular (LV) systolic and diastolic function in subjects with reduced LV ejection fraction (LVEF) in real-world studies. Subjects with heart failure and reduced EF (HFrEF), however, are also characterized by an impaired right ventricular (RV) function. We therefore aimed to evaluate whether also RV function may improve after S/V therapy and possible predictors of RV improvement could be identified at echocardiography and tissue Doppler imaging. METHODS: Fifty consecutive patients (67 ± 8 years, LVEF 28 ± 6%, male 86%) with chronic HFrEF and NYHA class II-III were followed up for 6 months after therapy with S/V. LV&RV function was assessed at baseline and after 6 months of therapy. RESULTS: After 6-month therapy with S/V a significant improvement was shown in the following echocardiography parameters assessing RV function: PAsP (31 ± 11 vs. 35 ± 10 mmHg, p < 0.001), TAPSE (19 ± 3 vs. 18 ± 3 mm, p < 0.001), RV FAC (38 ± 7 vs. 34 ± 6 mm, p < 0.001), RV S' (12 ± 2 vs. 10 ± 2 cm/s, p < 0.001), RV-FW-LS (-20 ± 5 vs. -18 ± 5%, p < 0.001), RV-4Ch-LS (-16 ± 5 vs. -14 ± 5%, p < 0.001). At multivariable analysis improvement in RV-FW-LS was associated to baseline levels of RV S' (r 0.75, p < 0.01) and RAV (r -0.32, p < 0.05). CONCLUSIONS: In a real-world scenario, 6-month therapy with S/V was associated with an improved RV function in HFrEF. RV function improvement may be predicted by assessing baseline RV S' and right atrial volume values.