Methylglyoxal-derived advanced glycation end products contribute to negative cardiac remodeling and dysfunction post-myocardial infarction.

Advanced glycation end-products (AGEs) have been associated with poorer outcomes after myocardial infarction (MI), and linked with heart failure. Methylglyoxal (MG) is considered the most important AGE precursor, but its role in MI is unknown. In this study, we investigated the involvement of MG-derived AGEs (MG-AGEs) in MI using transgenic mice that over-express the MG-metabolizing enzyme glyoxalase-1 (GLO1). MI was induced in GLO1 mice and wild-type (WT) littermates. At 6 h post-MI, mass spectrometry revealed that MG-H1 (a principal MG-AGE) was increased in the hearts of WT mice, and immunohistochemistry demonstrated that this persisted for 4 weeks. GLO1 over-expression reduced MG-AGE levels at 6 h and 4 weeks, and GLO1 mice exhibited superior cardiac function at 4 weeks post-MI compared to WT mice. Immunohistochemistry revealed greater vascular density and reduced cardiomyocyte apoptosis in GLO1 vs. WT mice. The recruitment of c-kit+ cells and their incorporation into the vasculature (c-kit+CD31+ cells) was higher in the infarcted myocardium of GLO1 mice. MG-AGEs appeared to accumulate in type I collagen surrounding arterioles, prompting investigation in vitro. In culture, the interaction of angiogenic bone marrow cells with MG-modified collagen resulted in reduced cell adhesion, increased susceptibility to apoptosis, fewer progenitor cells, and reduced angiogenic potential. This study reveals that MG-AGEs are produced post-MI and identifies a causative role for their accumulation in the cellular changes, adverse remodeling and functional loss of the heart after MI. MG may represent a novel target for preventing damage and improving function of the infarcted heart.

Riboflavin Surface Modification of Poly(vinyl chloride) for Light-Triggered Control of Bacterial Biofilm and Virus Inactivation.

Poly(vinyl chloride) (PVC) is the most used biomedical polymer worldwide. PVC is a stable and chemically inert polymer. However, microorganisms can colonize PVC producing biomedical device-associated infections. While surface modifications of PVC can help improve the antimicrobial and antiviral properties, the chemically inert nature of PVC makes those modifications challenging and potentially toxic. In this work, we modified the PVC surface using a derivative riboflavin molecule that was chemically tethered to a plasma-treated PVC surface. Upon a low dosage of blue light, the riboflavin tethered to the PVC surface became photochemically activated, allowing for Pseudomonas aeruginosa bacterial biofilm and lentiviral in situ eradication.

Mimicking biofilm formation and development: Recent progress in in vitro and in vivo biofilm models.

Biofilm formation in living organisms is associated to tissue and implant infections, and it has also been linked to the contribution of antibiotic resistance. Thus, understanding biofilm development and being able to mimic such processes is vital for the successful development of antibiofilm treatments and therapies. Several decades of research have contributed to building the foundation for developing in vitro and in vivo biofilm models. However, no such thing as an "all fit" in vitro or in vivo biofilm models is currently available. In this review, in addition to presenting an updated overview of biofilm formation, we critically revise recent approaches for the improvement of in vitro and in vivo biofilm models.