Biosafety of a novel covered self-expandable metal stent coated with poly(2-methoxyethyl acrylate) in vivo

Biliary stents for active materials and surface modification: Recent advances and future perspectives

Demand for biliary stents has expanded with the increasing incidence of biliary disease. The implantation of plastic or self-expandable metal stents can be an effective treatment for biliary strictures. However, these stents are nondegradable and prone to restenosis. Surgical removal or replacement of the nondegradable stents is necessary in cases of disease resolution or restenosis. To overcome these shortcomings, improvements were made to the materials and surfaces used for the stents. First, this paper reviews the advantages and limitations of nondegradable stents. Second, emphasis is placed on biodegradable polymer and biodegradable metal stents, along with functional coatings. This also encompasses tissue engineering & 3D-printed stents were highlighted. Finally, the future perspectives of biliary stents, including pro-epithelialization coatings, multifunctional coated stents, biodegradable shape memory stents, and 4D bioprinting, were discussed.

Roles of interfacial water states on advanced biomedical material design

When biomedical materials come into contact with body fluids, the first reaction that occurs on the material surface is hydration; proteins are then adsorbed and denatured on the hydrated material surface. The amount and degree of denaturation of adsorbed proteins affect subsequent cell behavior, including cell adhesion, migration, proliferation, and differentiation. Biomolecules are important for understanding the interactions and biological reactions of biomedical materials to elucidate the role of hydration in biomedical materials and their interaction partners. Analysis of the water states of hydrated materials is complicated and remains controversial; however, knowledge about interfacial water is useful for the design and development of advanced biomaterials. Herein, we summarize recent findings on the hydration of synthetic polymers, supramolecular materials, inorganic materials, proteins, and lipid membranes. Furthermore, we present recent advances in our understanding of the classification of interfacial water and advanced polymer biomaterials, based on the intermediate water concept.