Enhanced Tensile Properties, Biostability, and Biocompatibility of Siloxane–Cross-Linked Polyurethane Containing Ordered Hard Segments for Durable Implant Application

Abstract

This work developed a series of siloxane-modified polyurethane (PU–Si) containing ordered hard segments by a facile method. The polyaddition between poly(ε-caprolactone) and excess diurethane diisocyanate was carried out to synthesize a polyurethane prepolymer with terminal isocyanate groups, which was then end-capped by 3-aminopropyl triethoxysilane to produce alkoxysilane-terminated polyurethane; the target products of PU–Si were obtained with hydrolysis and the condensation of alkoxysilane groups. The chemical structures were confirmed by FT-IR and XPS, and the effect of the siloxane content or cross-linked degree on the physicochemical properties of the PU–Si films was investigated in detail. The formation of the network structure linked by Si–O–Si bonds and interchain denser hydrogen bonds endowed PU–Si films with fine phase compatibility, low crystallinity, high thermal stability, and excellent tensile properties. Due to the high cross-linked degree and low interfacial energy, the films displayed a high surface water contact angle and low equilibrium water absorption, which resulted in slow hydrolytic degradation rates. Furthermore, the evaluation of protein adsorption and platelet adhesion on the PU–Si film surface presented high resistance to biofouling, indicating superior surface biocompatibility. Consequently, the siloxane–cross-linked polyurethane, which possessed excellent tensile properties, high biostability, and superior biocompatibility, showed great potential to be explored as biomaterials for durable implants.

Surface Properties of a Biocompatible Thermoplastic Polyurethane and Its Anti-Adhesive Effect against E. coli and S. aureus

“…The data demonstrate that there is no significant difference between samples and all three surfaces did not allow platelets to adhere (A) (<0.5% adhesion vs. TCP). The results were due to the hydrophobicity of TPU, already reported by Villani et al [34], and our findings are in accordance with the literature [44,45]. Quantitative data are supported Figure 6.…”

“…Furthermore, the capacity of fibrinogen to adhere on modified TPU surfaces was evaluated, since the importance for platelets adhesion. The results, shown in Figure 7 and Table 1, confirmed that a low percentage, with respect to the TCP control, could bind to the surface [44]. There is no significant difference between film and brush, whose surfaces displayed circa 15% of fibrinogen adhesion.…”

“…To further characterize the biological properties of the TPU surfaces, the adhesion of platelets, fibrinogen [44,45], and eukaryotic cells was evaluated [46].…”

Intermolecular Interactions in 3-Aminopropyltrimethoxysilane, N-Methyl-3-aminopropyltrimethoxysilane and 3-Aminopropyltriethoxysilane: Insights from Computational Spectroscopy

“…It finds applications in industries like textiles, paints, and plastics, where improved surface properties are desired. The same applies in the biomedical and pharmaceutical fields, as the surface of biomaterials, such as implants or drug delivery systems, are used to improve biocompatibility, reduce immunogenicity, and enhance the interaction with biological tissues (see, e.g., [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]).…”