Poly(3-hydroxyoctanoate), a promising new material for cardiac tissue engineering.

Cardiac tissue engineering (CTE) is currently a prime focus of research because of an enormous clinical need. In the present work, a novel functional material, poly(3-hydroxyoctanoate), P(3HO), a medium chain-length polyhydroxyalkanoate (PHA), produced using bacterial fermentation, was studied as a new potential material for CTE. Engineered constructs with improved mechanical properties, crucial for supporting the organ during new tissue regeneration, and enhanced surface topography, to allow efficient cell adhesion and proliferation, were fabricated. Results showed that the mechanical properties of the final patches were close to that of cardiac muscle. Biocompatibility of neat P(3HO) patches, assessed using neonatal ventricular rat myocytes (NVRM), showed that the polymer was as good as collagen in terms of cell viability, proliferation and adhesion. Enhanced cell adhesion and proliferation properties were observed when porous and fibrous structures were incorporated into the patches. In addition, no deleterious effect was observed on adult cardiomyocyte contraction when cardiomyocytes were seeded on the P(3HO) patches. Hence, P(3HO)-based multifunctional cardiac patches are promising constructs for efficient CTE. This work will have a positive impact on the development of P(3HO) and other PHAs as a novel new family of biodegradable functional materials with huge potential in a range of different biomedical applications, particularly CTE, leading to further interest and exploitation of these materials. Copyright © 2016 John Wiley & Sons, Ltd.

An experimental, hands-on approach to epithelial ion transport: A simple technique for introducing students to ion transport in epithelia.

We have realized that our Biology undergraduate students learn biological concepts as established truths without awareness of the body of experimental evidence supporting the emerging models as usually presented in handbooks and texts in general. Therefore, we have implemented a laboratory practice in our course of Physiology and Biophysics, aimed to introduce the students in the way the scientific models and theories are built, through the measurement of Na(+) transport in frog skin. Transepithelial Na(+) transport was assessed in the frog skin, with measurements of short circuit currents. The mucosal Na(+) and serosal K(+) concentrations were modified and the effects were recorded. These effects were reversible. Addition of a drug that blocks epithelial Na(+) channels (amiloride) to the mucosal side solution abolished the short circuit current. Sodium fluxes were calculated, and the results were adjusted to Michaelis-Menten kinetics. The impact of the proposed practice on the students is discussed.