The Study of Bile Duct Stent Having Antifouling Properties Using Biomimetics Technique

Abstract

Biomimetics is a field of technologies based on imitating the functions and properties found in living organisms. The application of the super-water-repellent fine structure of lotus leaves to create waterproof products is a well-known example of biomimetics. The present study examined the surface structure of snail shells, which exhibit oleophobic properties oil repellency and explored the feasibility of recreating this structure on the inner surfaces of conventional biliary stents. Observations of snail shells under an electron microscope show a covering of extremely fine protrusions of around 200 nm in size. When water enters the pores between these fine protrusions, a film of water exhibiting supernanohydrophilic structure forms on the shell. Because water and oil are immiscible, this film repels oil. We would expect stent occlusion to be less likely with a biliary stent having this structure on its inner surface. Biliary stricture caused by bile duct cancer or bile duct obstruction can lead to icterus and may, in serious cases, induce fatal hepatic failure. A surgical procedure that places indwelling biliary stents inside the biliary tract is sometimes performed to secure a passage for bile flow. However, conventional stents are prone to occlusion due to the accumulation of biliary sludge, resulting in the need for a second surgery to replace the stent. This problem is attributable to the polyethylene used to make the biliary stents; polyethylene is susceptible to the adhesion of cholesterol and fats found in the bile, eventually leading to stent occlusions. This paper reports our efforts to develop biliary stents that feature antifouling properties inspired by biomimetics to address this problem; specifically, the development of oleophobic inner stent surfaces featuring supernanohydrophilic structures inspired by snail shell surfaces.

Recent Developments in Biomimetic Antifouling Materials: A Review

“…Ren et al have recently reported “mucus-like and hierarchical ciliary bionic” antifouling surfaces for marine antifouling applications [ 63 ]. Another group have used snail shells exhibiting oleophobic properties and a surface texture [ 64 ] to explore the feasibility of recreating similar structures on the inner surfaces of conventional biliary stents for antifouling purposes in medical fields [ 65 ]. Detailed electron microscopy observations of snail shells demonstrated surface features of around 200 nm in size.…”

“…The authors hypothesized that when water enters the pores between these surface features, a film of water exhibiting super-nanohydrophilic structure forms on the shell, thus creating an oil-repellent surface with some antifouling effect. They were able to replicate analogous surface features on stents and conduct in vivo studies that demonstrated antifouling effects on the basis of a reduction in fouled surface area observed [ 65 ].…”

Dust Adhesion Suppression Effect by Meta-material Structure

“…From theses backgrounds, we have been developing the antifouling technology [23][24][25][26][27][28][29] of the measurement target used by metamaterial effect. In this study, in preparation of the antifouling technology development, stick some kinds of sheets and evaluate the effect against to the water and the muddy water.…”

Component Analysis of Extraneous Stuffs Attached on Measurement Target of Track Irregularity

“…From theses backgrounds, we have been developing the antifouling technology of the measurement target used by metamaterial effect [5][6][7][8][9][10]. There have been many studies on polymer surfaces and water droplets [11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”