Exploring the relationship between epigenetic DNA methylation and cardiac fibrosis through Raman microspectroscopy.

Cardiomyopathies are associated with fibrotic remodeling of the heart, which is characterized by the excessive accumulation of collagen type I (COL I) due to chronic inflammation and suspected epigenetic influences. Despite the severity and high mortality rate of cardiac fibrosis, current treatment options are often inadequate, underscoring the importance of gaining a deeper understanding of the disease's underlying molecular and cellular mechanisms. In this study, the extracellular matrix (ECM) and nuclei in fibrotic areas of different cardiomyopathies were molecularly characterized by Raman microspectroscopy and imaging and compared with the control myocardium. Patient samples were obtained from heart tissue affected by ischemia, hypertrophy, and dilated cardiomyopathy and analyzed for fibrosis through conventional histology and marker-independent Raman microspectroscopy (RMS). Prominent differences between control myocardium and cardiomyopathies were revealed by spectral deconvolution of COL I Raman spectra. Statistically significant differences were identified in the amide I region of spectral subpeak at 1,608 cm-1, which is a representative endogenous marker for alterations in the structural conformation of COL I fibers. Moreover, epigenetic 5mC DNA modification was identified within cell nuclei by multivariate analysis. A statistically significant increase in signal intensities of spectral features indicative of DNA methylation was detected in cardiomyopathies in accordance with immunofluorescence 5mC staining. Overall, RMS is a versatile technology in the discrimination of cardiomyopathies based on molecular evaluation of COL I and nuclei while providing insights into the pathogenesis of the diseases.NEW & NOTEWORTHY Cardiomyopathies are associated with severe fibrotic remodeling of the heart, which is characterized by the excessive accumulation of collagen type I (COL I). In this study, we used marker-independent Raman microspectroscopy (RMS) to gain a deeper understanding of the disease's underlying molecular and cellular mechanisms.

Surface functionalization of electrospun scaffolds using recombinant human decorin attracts circulating endothelial progenitor cells.

Decorin (DCN) is an important small leucine-rich proteoglycan present in the extracellular matrix (ECM) of many organs and tissues. Endothelial progenitor cells (EPCs) are able to interact with the surrounding ECM and bind to molecules such as DCN. Here, we recombinantly produced full-length human DCN under good laboratory practice (GLP) conditions, and after detailed immunological characterization, we investigated its potential to attract murine and human EPCs (mEPCs and hECFCs). Electrospun polymeric scaffolds were coated with DCN or stromal cell-derived factor-1 (SDF-1α) and were then dynamically cultured with both cell types. Cell viability was assessed via imaging flow cytometry. The number of captured cells was counted and compared with the non-coated controls. To characterize cell-scaffold interactions, immunofluorescence staining and scanning electron microscopy analyses were performed. We identified that DCN reduced T cell responses and attracted innate immune cells, which are responsible for ECM remodeling. A significantly higher number of EPCs attached on DCN- and SDF-1α-coated scaffolds, when compared with the uncoated controls. Interestingly, DCN showed a higher attractant effect on hECFCs than SDF-1α. Here, we successfully demonstrated DCN as promising EPC-attracting coating, which is particularily interesting when aiming to generate off-the-shelf biomaterials with the potential of in vivo cell seeding.

Steps toward Maturation of Embryonic Stem Cell-Derived Cardiomyocytes by Defined Physical Signals.

Cardiovascular disease remains a leading cause of mortality and morbidity worldwide. Embryonic stem cell-derived cardiomyocytes (ESC-CMs) may offer significant advances in creating in vitro cardiac tissues for disease modeling, drug testing, and elucidating developmental processes; however, the induction of ESCs to a more adult-like CM phenotype remains challenging. In this study, we developed a bioreactor system to employ pulsatile flow (1.48 mL/min), cyclic strain (5%), and extended culture time to improve the maturation of murine and human ESC-CMs. Dynamically-cultured ESC-CMs showed an increased expression of cardiac-associated proteins and genes, cardiac ion channel genes, as well as increased SERCA activity and a Raman fingerprint with the presence of maturation-associated peaks similar to primary CMs. We present a bioreactor platform that can serve as a foundation for the development of human-based cardiac in vitro models to verify drug candidates, and facilitates the study of cardiovascular development and disease.

ECM and ECM-like materials - Biomaterials for applications in regenerative medicine and cancer therapy.

Regenerative strategies such as stem cell-based therapies and tissue engineering applications are being developed with the aim to replace, remodel, regenerate or support damaged tissues and organs. In addition to careful cell type selection, the design of appropriate three-dimensional (3D) scaffolds is essential for the generation of bio-inspired replacement tissues. Such scaffolds are usually made of degradable or non-degradable biomaterials and can serve as cell or drug carriers. The development of more effective and efficient drug carrier systems is also highly relevant for novel cancer treatment strategies. In this review, we provide a summary of current approaches that employ ECM and ECM-like materials, or ECM-synthetic polymer hybrids, as biomaterials in the field of regenerative medicine. We further discuss the utilization of such materials for cell and drug delivery, and highlight strategies for their use as vehicles for cancer therapy.