Structure–property relations and cytotoxicity of isosorbide‐based biodegradable polyurethane scaffolds for tissue repair and regeneration

Abstract

Microporous scaffolds with potential applications for tissue engineering were produced from the biodegradable aliphatic isosorbide-based polyurethane using a combined salt leaching-solvent evaporation-coagulation process. Alkaline sodium phosphate heptahydrate crystals were used as a solid porogene, and acetone-water mixture was used as a nonsolvent-coagulant. The scaffolds used in this study had interconnected pores with sizes in the range of 70-120 microm and a pore-to-volume ratio of 87%. The XPS measurements showed that the residence of the scaffold in an aqueous solution of the alkaline porogene changed its surface atomic composition, that is increased the surface concentration of oxygen and nitrogen and reduced the surface concentration of hydrocarbons relative to the control material. This also enhanced the hydrophilicity of the scaffold's surfaces as assessed from contact angle measurements. The alkaline porogene did not affect the polymer's molecular weight. The MTT cytotoxicity assay showed that the isosorbide-based polyurethane scaffold is noncytotoxic. The amounts of interleukin-6 and interleukin-8 proinflammatory cytokines released from human blood leukocytes exposed to the polyurethane scaffolds in vitro were comparable and/or lower than the amount of the cytokines released by leukocytes exposed to the culture-grade polystyrene control.

In vitro and in vivo evaluation of a novel nanosize hydroxyapatite particles/poly(ester-urethane) composite scaffold for bone tissue engineering

“…This rearrangement has already been observed, albeit to a lesser extent, during PU scaffold processing and has been attributed to non-polar, carbon-containing methylene mobility at the surface [20]. Moreover, the etching of the scaffold surface by the alkaline sodium phosphate heptahydrate solution during porogen dissolution in water, which catalyzes ester bond hydrolysis and creates surface carboxylic functions, was also suggested as a source of surface oxygen increase [20]. Overall, both material processing and nHA Table 2 Rolling and adherent leukocytes in postcapillary and collecting venules within the border zones of PU and nHA/PU scaffolds directly (0 days) as well as on days 3, 6, 10 and 14 after implantation into the dorsal skinfold chamber of BALB/c mice.…”

“…The addition of nHA particles to the PU increased the surface oxygen content by 6.72%, which may be best explained by the interaction of nHA particles and PU, resulting in changes of macromolecule mobility during the foam processing and surface chemistry modifications [7]. This rearrangement has already been observed, albeit to a lesser extent, during PU scaffold processing and has been attributed to non-polar, carbon-containing methylene mobility at the surface [20]. Moreover, the etching of the scaffold surface by the alkaline sodium phosphate heptahydrate solution during porogen dissolution in water, which catalyzes ester bond hydrolysis and creates surface carboxylic functions, was also suggested as a source of surface oxygen increase [20].…”

“…The O1s peak could be resolved into two component peaks at 531.80 ± 0.40 eV (O@C) and 533.17 ± 0.35 eV (O-C) [20]. Finally, the N1s peak could be resolved into one peak at 400.0 eV (N-C(O)-O) [19,20]. The ratio between the C-O/C@O C1s and O-C/O@C O1s components are reported in Table 1.…”

“…High-resolution spectra of the C1s peak were resolved into three component peaks at 285.02 ± 0.02 eV (aliphatic carbon C-R, where R denotes C or H), 286.50 ± 0.05 eV (C-O) and 289.13 ± 0.12 eV (C@O) [19]. The O1s peak could be resolved into two component peaks at 531.80 ± 0.40 eV (O@C) and 533.17 ± 0.35 eV (O-C) [20]. Finally, the N1s peak could be resolved into one peak at 400.0 eV (N-C(O)-O) [19,20].…”

Manufacturing of biodegradable polyurethane scaffolds based on polycaprolactone using a phase separation method: physical properties and in vitro assay

“…8 Recently, investigators have designed biodegradable polyurethanes for applications such as artificial skin, 9 bone graft substitutes, 10 drug delivery systems, 11 and porous scaffolds for regenerating damaged tissues. 12 The biodegradability and biocompatibility of the polyurethanes are determined by their composition and preparation. 13 Polyurethanes containing ester or ether groups are vulnerable to degradation through hydrolysis in vivo.…”