Effect of Pore Size, Lubricant Viscosity, and Distribution on the Slippery Properties of Infused Cement Surfaces

The fabrication of slippery liquid-infused porous surfaces (SLIPS) usually requires the use of structured substrates, with specifically designed micro- and nanoroughness and complementary surface chemistry, ideally suited to trap lubricants. It is not yet established whether a random roughness, with a range of pores with a variable size reaching deep into the bulk of the material, is suitable for successful infusion. In this study, a highly porous material with random and complex roughness, obtained by using portland cement (the most common type of cementitious material), was tested for its potential to act as a SLIP surface. Atomic force microscopy meniscus measurements were used to investigate the distribution of lubricants on the surface upon subsequent stages of depletion because of the capillary absorption of the lubricant within the porous structure. Factors such as curing time of the cement paste, time since infusion, and lubricant viscosity were varied to identify the conditions under which infusion could be considered successful. A sensitive method to evaluate the penetration of liquid (low-temperature differential scanning calorimetry) was used, which could be applicable to many porous materials. The optimized infusion of cement surfaces ultimately resulted in the desired hallmarks of SLIPS, that is, high water repellence and slipperiness, effective for several weeks, reduced water permeability, and icephobicity

Polyenylphosphatidylcholines as bioactive excipient in tablets for the treatment of liver fibrosis.

Liver fibrosis is a condition characterized by the accumulation of extracellular matrix (ECM) arising from the myofibroblastic transdifferentiation of hepatic stellate cells (HSCs) occurring as the natural response to liver damage. To date, no pharmacological treatments have been specifically approved for liver fibrosis. We recently reported a beneficial effect of polyenylphosphatidylcholines (PPCs)-rich formulations in reverting fibrogenic features of HSCs. However, unsaturated phospholipids' properties pose a constant challenge to the development of tablets as preferred patient-centric dosage form. Profiting from the advantageous physical properties of the PPCs-rich Soluthin® S 80 M, we developed a tablet formulation incorporating 70% w/w of this bioactive lipid. Tablets were characterized via X-ray powder diffraction, thermogravimetry, and Raman confocal imaging, and passed the major compendial requirements. To mimic physiological absorption after oral intake, phospholipids extracted from tablets were reconstituted as protein-free chylomicron (PFC)-like emulsions and tested on the fibrogenic human HSC line LX-2 and on primary cirrhotic rat hepatic stellate cells (PRHSC). Lipids extracted from tablets and reconstituted in buffer or as PFC-like emulsions exerted the same antifibrotic effect on both activated LX-2 and PRHSCs as observed with plain S 80 M liposomes, showing that the manufacturing process did not interfere with the bioactivity of PPCs