Characterization of thermoplastic polyurethane/polylactic acid (TPU/PLA) tissue engineering scaffolds fabricated by microcellular injection molding

Abstract

Polylactic acid (PLA) and thermoplastic polyurethane (TPU) are two kinds of biocompatible and biodegradable polymers that can be used in biomedical applications. PLA has rigid mechanical properties while TPU possesses flexible mechanical properties. Blended TPU/PLA tissue engineering scaffolds at different ratios for tunable properties were fabricated via twin screw extrusion and microcellular injection molding techniques for the first time. Multiple test methods were used to characterize these materials. Fourier transform infrared spectroscopy (FTIR) confirmed the existence of the two components in the blends; differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) confirmed the immiscibility between the TPU and PLA. Scanning electron microscopy (SEM) images verified that, at the composition ratios studied, PLA was dispersed as spheres or islands inside the TPU matrix and that this phase morphology further influenced the scaffold’s microstructure and surface roughness. The blends exhibited a large range of mechanical properties that covered several human tissue requirements. 3T3 fibroblast cell culture showed that the scaffolds supported cell proliferation and migration properly. Most importantly, this study demonstrated the feasibility of mass producing biocompatible PLA/TPU scaffolds with tunable microstructures, surface roughnesses, and mechanical properties that have the potential to be used as artificial scaffolds in multiple tissue engineering applications.

Development and molecular characterization of polymeric micro-nanofibrous scaffold of a defined 3-D niche for in vitro chemosensitivity analysis against acute myeloid leukemia cells

“…As shown in Figure S2, the FTIR spectrum of phase-separated scaffold of 100% PU showed the characteristic absorption peaks of PU at 3,448 cm -1 (stretching vibration of N-H bond in the urethane segments), 2,927-2,852.76 cm -1 (C-H stretching of alkane) and1,647 cm -1 . 28 The FTIR spectrum of 100% PLLA nanofibrous scaffold depicted characteristic absorption bands at 2,999 cm -1 (carboxylic acid O-H stretch), and 1,769 cm -1 , which represents the characteristic peaks of the ester backbone of PLLA.…”

“…Optical density was recorded at 562 nm using a BioTek PowerWave™ XS plate reader (BioTek Instruments Inc, Winooski, VT, USA). 28 …”

Thermoplastic Foams: Processing, Manufacturing, and Characterization

“…Poly (lactide acid) or polylactide (PLA) is a biodegradable and biocompatible polymer produced from such renewable sources as cornstarch and sugarcane [1][2][3][4]. PLA foam is a competitive material among most of other thermoplastic foams due to its biocompatibility and biodegradability, PLA has been widely used in tissue engineering applications such as skin, bones, blood vessels, due to their highly porous structure as scafolds in last [4].…”

“…PLA foam is a competitive material among most of other thermoplastic foams due to its biocompatibility and biodegradability, PLA has been widely used in tissue engineering applications such as skin, bones, blood vessels, due to their highly porous structure as scafolds in last [4].…”

“…Application area of the polymer foams has high variety such as transportation, bedding, carpet underlay, textile, toys, sport instruments, insulation appliances, and construction, biomedical, and automotive sectors [1][2][3][4][5]. A polymer foam is basically a polymer-and-gas mixture, which gives the material a microcellular structure.…”