Understanding the role of dip-coating process parameters in the mechanical performance of polymer-coated bioglass robocast scaffolds. (December 2016)

• Record Type: Journal Article
• Authors: Motealleh, Azadeh; Eqtesadi, Siamak; Perera, Fidel Hugo; Pajares, Antonia; Guiberteau, Fernando; Miranda, Pedro
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 64(2016)
• Page Start: 253
• Page End: 261
• Publication Date: 2016-12
• Subjects: Dip-coating -- 45S5 bioactive glass -- Scaffold -- Robocasting -- Mechanical properties; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2016.08.004
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: The effect of different dip-coating variables—solvent, deposition temperature and polymer concentration—on the mechanical performance of polycaprolactone-coated 45S5 bioglass robocast scaffolds is systematically analyzed in this work. The reproducible geometry of the scaffolds produced by this additive manufacturing technique makes them an optimal model system and facilitates the analysis. The results suggest that the mechanical performance of the hybrid scaffolds is improved monotonically with polymer concentration, but this concentration cannot be increased indefinitely if the macroporosity interconnectivity, and thus the scaffold׳s capacity to promote tissue ingrowth, are to be preserved. An optimal concentration, and therefore viscosity (~1–4 Pa s in the present case), exists for any given set of process variables (scaffold geometry and material, polymer, solvent and process temperature) that yields coatings with optimal reinforcement and minimal reduction of scaffold functionality. Solvent and process temperature do not directly affect the strengthening provided by the polymeric coating. However they can determine the maximum concentration at the critical viscosity, and thereby the maximum achievable mechanical performance of the resulting hybrid scaffold. Graphical abstract: Highlights: Dip-coating can produce bioglass/PCL robocast scaffolds with improved performance. Polymer concentration determines the mechanical properties of coated scaffolds. Concentration cannot be increased indefinitely while preserving macroporosity. Solvent and temperature have secondary roles, but affect the maximum concentration.