HepG2 and human healthy hepatocyte in vitro culture and co-culture in PCL electrospun platforms

The discovery of new drugs to treat pathological cells in the case of aggressive liver primary cancer is imposing the identification of high-throughput screening systems to predict the in vivo response of new therapeutic molecules, in order to reduce current use of animals and drug testing costs. Recently, micro/nanostructured scaffolds have been adopted to reproduce the hepatic microenvironment due to their higher similarity to the biological niche with respect to the traditional two-dimensional culture plate, so providing novel in vitro models for reliably understanding molecular mechanisms related to cancer cells activity. Herein, we propose the study of electrospun scaffolds made of polycaprolactone as in vitro model that can mimic the morphological organization of native extracellular matrix and the co-culture of hepatic cell lines-i.e., HepG2, human healthy hepatocytes (HHH). The micro- and nano-scale morphological features of fibers with diameter equal to (3.22 ± 0.42) μm and surface roughness of (17.84 ± 4.43) nm-allow the reproduction of the in vivo scenario influencing the adhesion and proliferation rate of the cultured cells. A much lower proliferation rate is observed for the HepG2 cells compared to the HHH cells, when cultured on the fibrous scaffolds over a time course of 4 weeks. Moreover, results on oxidative stress mechanisms indicate an antioxidant effect of fibers mainly in the case of co-colture, thus suggesting a promising use as new in vitro models to explore alternative therapeutic strategies in hepatocarcinoma treatment.

Needle-like ion-doped hydroxyapatite crystals influence osteogenic properties of PCL composite scaffolds

Surface topography and chemistry both play a crucial role on influencing cell response in 3D porous scaffolds in terms of osteogenesis. Inorganic materials with peculiar morphology and chemical functionalities may be proficiently used to improve scaffold properties-in the bulk and along pore surface-promoting in vitro and in vivo osseous tissue in-growth. The present study is aimed at investigating how bone regenerative properties of composite scaffolds made of poly(Ɛ-caprolactone) (PCL) can be augmented by the peculiar properties of Mg(2+) ion doped hydroxyapatite (dHA) crystals, mainly emphasizing the role of crystal shape on cell activities mediated by microstructural properties. At the first stage, the study of mechanical response by crossing experimental compression tests and theoretical simulation via empirical models, allow recognizing a significant contribution of dHA shape factor on scaffold elastic moduli variation as a function of the relative volume fraction. Secondly, the peculiar needle-like shape of dHA crystals also influences microscopic (i.e. crystallinity, adhesion forces) and macroscopic (i.e. roughness) properties with relevant effects on biological response of the composite scaffold: differential scanning calorimetry (DSC) analyses clearly indicate a reduction of crystallization heat-from 66.75 to 43.05 J g(-1)-while atomic force microscopy (AFM) ones show a significant increase of roughness-from (78.15  ±  32.71) to (136.13  ±  63.21) nm-and of pull-off forces-from 33.7% to 48.7%. Accordingly, experimental studies with MG-63 osteoblast-like cells show a more efficient in vitro secretion of alkaline phosphatase (ALP) and collagen I and a more copious in vivo formation of new bone trabeculae, thus suggesting a relevant role of dHA to support the main mechanisms involved in bone regeneration.

Chemical-biological warfare: medical logistics and defense

In this article, the authors discuss some of the hard realities of chemical and biological warfare defense in terms of the medical and medical logistics implications. In the opinion of the authors, there are no adequate defensive measures at present which would protect troops and sailors from the effects of either chemical or biological warfare tactics. An overview of the current world situation is presented, as well as some of the clinical and logistical responses to chem-bio war. The effectiveness of vaccinations or other medical approaches to protecting service members from chem-bio attacks is questioned in light of the technology and of the unpredictability in guessing the agent's strain or nature (e.g. viral, bacterial, or chemical). An analysis of Mission Oriented Protective Posture gear, gas masks, and other potential external protection devices reveals them to be inadequate, impractical, or expensive. In short, whether facing known war arsenals or unknown terrorist possibilities, the armed forces of the United States when meeting chemical or biological agents will be hard-pressed to protect and heal themselves, much less the nation's civilian population.