Design and development of poly-L/D-lactide copolymer and barium titanate nanoparticle 3D composite scaffolds using breath figure method for tissue engineering applications

In tissue engineering, the scaffold topography influences the adhesion, proliferation, and function of cells. Specifically, the interconnected porosity is crucial for cell migration and nutrient delivery in 3D scaffolds. The objective of this study was to develop a 3D porous composite scaffold for musculoskeletal tissue engineering applications by incorporating barium titanate nanoparticles (BTNPs) into a poly-L/D-lactide copolymer (PLDLA) scaffold using the breath figure method. The porous scaffold fabrication utilised 96/04 PLDLA, dioleoyl phosphatidylethanolamine (DOPE), and different types of BTNPs, including uncoated BTNPs, Al2O3-coated BTNPs, and SiO2-coated BTNPs. The BTNPs were incorporated into the polymer scaffold, which was subsequently analysed using field emission scanning electron microscopy (FE-SEM). The biocompatibility of each scaffold was tested using ovine bone marrow stromal stem cells. The cell morphology, viability, and proliferation were evaluated using FE-SEM, LIVE/DEAD staining, and Prestoblue assay. Porous 3D composite scaffolds were successfully produced, and it was observed that the incorporation of uncoated BTNPs increased the average pore size from 1.6 mu m (PLDLA) to 16.2 mu m (PLDLA/BTNP). The increased pore size in the PLDLA/BTNP scaffolds provided a suitable porosity for the cells to migrate inside the scaffold, while in the pure PLDLA scaffolds with their much smaller pore size, cells elongated on the surface. To conclude, the breath figure method was successfully used to develop a PLDLA/BTNP scaffold. The use of uncoated BTNPs resulted in a composite scaffold with an optimal pore size while maintaining the honeycomb-like structure. The composite scaffolds were biocompatible and yielded promising structures for future tissue engineering applications.Peer reviewe

miR-1468-3p promotes aging–related cardiac fibrosis

Abstract Non-coding microRNAs (miRNAs) are powerful regulators of gene expression and critically involved in cardiovascular pathophysiology. The aim of the current study was to identify miRNAs regulating cardiac fibrosis. Cardiac samples of age-matched control subjects and sudden cardiac death (SCD) victims with primary myocardial fibrosis (PMF) were subjected to miRNA profiling. Old SCD victims with PMF and healthy aged human hearts showed increased expression of miR-1468-3p. In vitro studies in human cardiac fibroblasts showed that augmenting miR-1468-3p levels induces collagen deposition and cell metabolic activity and enhances collagen 1, connective tissue growth factor, and periostin expression. In addition, miR-1468-3p promotes cellular senescence with increased senescence-associated β-galactosidase activity and increased expression of p53 and p16. AntimiR-1468-3p antagonized transforming growth factor β1 (TGF-β1)-induced collagen deposition and metabolic activity. Mechanistically, mimic-1468-3p enhanced p38 phosphorylation, while antimiR-1468-3p decreased TGF-β1-induced p38 activation and abolished p38-induced collagen deposition. RNA sequencing analysis, a computational prediction model, and qPCR analysis identified dual-specificity phosphatases (DUSPs) as miR-1468-3p target genes, and regulation of DUSP1 by miR-1468-3p was confirmed with a dual-luciferase reporter assay. In conclusion, miR-1468-3p promotes cardiac fibrosis by enhancing TGF-β1-p38 signaling. Targeting miR-1468-3p in the older population may be of therapeutic interest to reduce cardiac fibrosis

MiR‐185‐5p regulates the development of myocardial fibrosis

Abstract Background: Cardiac fibrosis stiffens the ventricular wall, predisposes to cardiac arrhythmias and contributes to the development of heart failure. In the present study, our aim was to identify novel miRNAs that regulate the development of cardiac fibrosis and could serve as potential therapeutic targets for myocardial fibrosis. Methods and results: Analysis for cardiac samples from sudden cardiac death victims with extensive myocardial fibrosis as the primary cause of death identified dysregulation of miR‐185‐5p. Analysis of resident cardiac cells from mice subjected to experimental cardiac fibrosis model showed induction of miR‐185‐5p expression specifically in cardiac fibroblasts. In vitro, augmenting miR‐185‐5p induced collagen production and profibrotic activation in cardiac fibroblasts, whereas inhibition of miR‐185‐5p attenuated collagen production. In vivo, targeting miR‐185‐5p in mice abolished pressure overload induced cardiac interstitial fibrosis. Mechanistically, miR‐185‐5p targets apelin receptor and inhibits the anti-fibrotic effects of apelin. Finally, analysis of left ventricular tissue from patients with severe cardiomyopathy showed an increase in miR‐185‐5p expression together with pro-fibrotic TGF‐β1 and collagen I. Conclusions: Our data show that miR‐185‐5p targets apelin receptor and promotes myocardial fibrosis