Influence of Hard Segments of Polyurethane on Cell Growth

Abstract

Polyurethanes (PU) with suitable soft segments have been found to be good blood-compatible polymers and have attracted much attention recently. In this study, various molar amounts of 4,4'-methylene bisphenyl isocyanate reacted with poly(tetramethy1ene oxide) were synthesized to explore the optimal ratio of hard/soft segments for cell attachment and proliferation in in uitro systems. Differential scanning calorimetry and dynamic mechanical analysis were used to determine the physical properties, hydrogen bonding index (HBI) and transmission electron microscopy to observe the phase-separation phenomena in the materials, and 3T3 fibroblast to evaluate the dependence of the cell proliferation at 37°C on the material properties. Our results show that cell attachment and proliferation are closely related to the cell growth surface, which in turn is controlled by (1) the ratio of hard to total segment concentration and (2) the recrystallization temperature (T,) of PU. To obtain a good cell growth surface, the ratio of hard to total segment concentration is found to be between 0.4 and 0.6, and HBI is between 1.5 and 2.1. Furthermore, when the T, of PU is near the physiology temperature, a stable surface for cell growth can be provided. The shorter molecules in the soft segment region can rearrange the molecular chain at 37°C. K e y words: polyurethane, cell growth, phase separation, hydrogen bonding index, cytotoxicity.

UV-curable low-surface-energy fluorinated poly(urethane-acrylate)s for biomedical applications

“…There are many factors that affect blood adhesion. The microphase separation resulting from the hydrophilic/hydrophobic nature of a material's surface is one factor determining its blood compatibility, but other basic surface propertiesincluding the surface roughness, free energy, electric charge, and polarization distribution -also can exert their effects [10,11,58].…”

“…Polyurethanes are frequently used in artificial hearts, vascular prostheses, and many types of catheters in various clinical applications. Hydrophilic/ hydrophobic microdomain structures, such as those of polyurethane, generally display higher blood compatibility [10,11]. Grasel and Cooper reported that materials exhibiting a greater amount of phase separation had low platelet and fibrinogen deposition levels [12].…”

Influence of the Nature of Acrylates on the Reactivity, Structure, and Properties of Polyurethane Acrylates

“…Hydrophilic/hydrophobic microdomain structures, such as those of polyurethane, generally display higher blood compatibility. 24,25 The growing commercial importance of polyurethane materials emphasizes the need for the study of polyurethane formation with respect to parameters such as chemical properties; micro-, macro-, and nanostructures; reagent concentrations; reaction media; and catalysts. Maji and Bhowmick reported micro-and nanostructured PUs based on various hyperbranched polymers.…”

“…From the biomedical point of view, polyurethanes are frequently used in the biomedical and pharmaceutical fields, in drug delivery systems, artificial hearts, vascular prostheses, and various types of catheters in clinical applications. Hydrophilic/hydrophobic microdomain structures, such as those of polyurethane, generally display higher blood compatibility. , The growing commercial importance of polyurethane materials emphasizes the need for the study of polyurethane formation with respect to parameters such as chemical properties; micro-, macro-, and nanostructures; reagent concentrations; reaction media; and catalysts. Maji and Bhowmick reported micro- and nanostructured PUs based on various hyperbranched polymers. , Until now, there are only a few literature references on polyurethane acrylate. ,, …”