Fabrication and characterization of customized tubular scaffolds for tracheal tissue engineering by using solvent based 3D printing on predefined template

Abstract

Purpose This paper aims to discuss the successful fabrication of customized tubular scaffolds for tracheal tissue engineering with a novel route using solvent-based extrusion 3D printing. Design/methodology/approach The manufacturing approach involved extrusion of polymeric ink over a rotating predefined pattern to construct customized tubular structure of polycaprolactone (PCL) and polyurethane (PU). Dimensional deviation in thickness of scaffolds were calculated for various layer thicknesses of 3D printing. Physical and chemical properties of scaffolds were investigated by scanning electron microscope (SEM), contact angle measurement, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD). Mechanical characterizations were performed, and the results were compared to the reported properties of human native trachea from previous reports. Additionally, in vitro cytotoxicity of the fabricated scaffolds was studied in terms of cell proliferation, cell adhesion and hemagglutination assay. Findings The developed fabrication route was flexible and accurate by printing customized tubular scaffolds of various scales. Physiochemical results showed good miscibility of PCL/PU blend, and decrease in crystalline nature of blend with the addition of PU. Preliminary mechanical assessments illustrated comparable mechanical properties with the native human trachea. Longitudinal compression test reported outstanding strength and flexibility to maintain an unobstructed lumen, necessary for the patency. Furthermore, the scaffolds were found to be biocompatible to promote cell adhesion and proliferation from the in vitro cytotoxicity results. Practical implications The attempt can potentially meet the demand for flexible tubular scaffolds that ease the concerns such as availability of suitable organ donors. Originality/value 3D printing over accurate predefined templates to fabricate customized grafts gives novelty to the present method. Various customized scaffolds were compared with conventional cylindrical scaffold in terms of flexibility.

Statistical modelling and optimization of print quality and mechanical properties of customized tubular scaffolds fabricated using solvent-based extrusion 3D printing process

“…The polymeric scaffolds of PCL, PCL/PU and PU, post drying in a vacuum oven at 50°C for 48 h, showed no toxicity during the in vitro study (MTS assay for 21 days) that can be found in the authors' previous research work. 18 It indicated that the possibility of the toxic residual present in the samples was insignificant, though the measurement of solvent residual was not performed in the present work.…”

“…The 3D printer worked on an indigenous algorithm which allowed the extruder to extrude over a rotating template making an axisymmetric part. 18 It included a syringe plunger arrangement which was operated by three motors namely M1, M2 and M3.…”

Converging 3D Printing and Electrospinning: Effect of Poly(l‐lactide)/Gelatin Based Short Nanofibers Aerogels on Tracheal Regeneration

“…The hemolysis ratio of scaffolds was less than 2%, which demonstrated their good hemocompatibility. [ 24 ] To further discern the biocompatibility of the scaffolds, the cell seeding efficiency was determined, which was found to be 82.5 ± 1.7%, 92.2 ± 3.4%, and 96.1 ± 1.9% for TSF0.5, TSF1.0, and TSF1.5 scaffolds, respectively (Figure 7b). The tracheal scaffolds showed higher numbers of cells than that of the SF aerogels, which may be ascribed to their 3D porous structure conducive for cell proliferation and adhesion.…”

“…While tissue‐engineered tracheal scaffolds possess great potential for the replacement of defected tracheal tissues, fabricating a suitable tracheal candidate mimicking the NT structurally and functionally still faces numerous challenges. [ 3,24 ] Fabrication techniques, such as electrospinning and 3D printing can be exploited to fabricate tracheal scaffolds. [ 25 ] However, tracheal scaffolds fabricated from each of these techniques face several limitations; electrospun nanofibers exhibit compact structure, which may impede the diffusion of nutrients and oxygen as well as the infiltration of cellular components and tissues into scaffolds.…”

“…The normal saline and deionized water served as negative and positive controls, respectively. [ 24 ] The hemocompatibility was calculated by using Equation 8 ( n = 5) $$\begin{equation}{\rm{Hemolysis\;ratio}}\;\left( \% \right)\; = \;\left[ {\left( {{A_{\rm{T}}} - {A_{\rm{N}}}} \right)/\left( {{A_{\rm{P}}} - {A_{\rm{N}}}} \right)} \right]\; \times 100\% \;\end{equation}$$where, A T represented the OD of the sample. A P and A N were the corresponding OD values of positive and negative control groups, respectively.…”