Novel three‐dimensional printing of poly(ester urethane) scaffolds for biomedical applications

Abstract

Tissue engineering requires highly porous complex structures with interconnected pores and tightly controlled pore sizes, added to customized production. Additive manufacturing (AM) is nowadays one of the most suitable technologies for the preparation of structures with strictly defined complex three‐dimensional architectures. Moreover, computed tomography and magnetic resonance imaging can be employed to obtain personalized medical devices. Fused deposition modeling (FDM) is one of the most common, easiest, and cost‐effective AM techniques to obtain 3D objects from a wide variety of materials. However, there is a lack of bioresorbable materials that can fit the increasing demand for biomedical applications requiring stiff elastomers. In this work, a series of bioresorbable segmented poly(ester urethanes) (SPEU) with high hard segment content was synthesized and physicochemically characterized. The materials with higher thermal stability were processed into homogeneous filaments by hot‐melt extrusion with no need for additives nor plasticizers. These filaments were evaluated for FDM, and structures with controlled porosity, filament diameter, and in‐plane pore size could be easily obtained by modifying the printing parameters. Regarding SPEU mechanical properties, the obtained scaffolds could be promising for cartilage tissue engineering applications.

Additive manufacturing of bioresorbable poly(ester‐urethane)/glass‐ceramic composite scaffolds

“…Melt flow indexes (MFI) of 196.0 ± 14.8 g/10 min (157 C) and 73.1 ± 8.2 g/10 min (165 C) were measured for SPEU50 and SPEU60, respectively. [23] These values are higher than the MFI threshold of 10 g/10 min, required for an acceptable extrusion and 3D printing quality. [39] Plain SPEU and composite filaments of SPEU with GC microparticles (5% and 10% wt/wt) were successfully produced by combining compounding and filament formation in one extrusion system.…”

“…Melt flow indexes (MFI) of 196.0 ± 14.8 g/10 min (157°C) and 73.1 ± 8.2 g/10 min (165°C) were measured for SPEU50 and SPEU60, respectively. [ 23 ] These values are higher than the MFI threshold of 10 g/10 min, required for an acceptable extrusion and 3D printing quality. [ 39 ]…”

“…Bioresorbable aliphatic SPEU were synthesized by a classic two‐step polymerization method. [ 23 ] SPEU were formulated from HDI/PCL/BDO [2.01:0.25:1.75] and [2.01:0.16:1.84] mole ratios to obtain polymers with hard segment (HS) contents of 50% and 60% wt/wt, named SPEU50 and SPEU60, respectively. HDI was reacted with PCL diol in presence of DBTDL and a minimum amount of DMAc.…”

“…Scaffolds with different morphologies were obtained and characterized. [23] The use of polymer/bioactive ceramic composite scaffolds is a well-known strategy to combine to the beneficial properties of two or more types of materials to best suit the mechanical and physiological demands of the host tissues. [24][25][26][27] In this sense, Ryszkowska and coworkers reported on the biodegradable polyurethane/Bioglass ® composite scaffolds by a salt leaching/polymer coagulation method.…”

Biodegradable and Biocompatible Thermoplastic Poly(Ester-Urethane)s Based on Poly(ε-Caprolactone) and Novel 1,3-Propanediol Bis(4-Isocyanatobenzoate) Diisocyanate: Synthesis and Characterization

“…The vast majority of polyurethanes are designed to withstand long periods of service, which require biostable materials [ 1 ]. However, there is currently great interest in the development of biodegradable polymers for certain biomedical applications, such as tissue regeneration [ 2 , 3 ] or controlled drug release [ 4 , 5 ]. Specifically, in these applications, PUs not only need to meet certain physical and/or mechanical requirements, but it is also necessary to assess whether the building blocks and their degradation products are biocompatible, non-toxic, and metabolized by the living organism.…”