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

2021 ◽  
Vol 27 (2) ◽  
pp. 421-428
Author(s):  
Rudranarayan Kandi ◽  
Pulak Mohan Pandey ◽  
Misba Majood ◽  
Sujata Mohanty

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.

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiongfeng Tang ◽  
Yanguo Qin ◽  
Xinyu Xu ◽  
Deming Guo ◽  
Wenli Ye ◽  
...  

For bone tissue engineering, the porous scaffold should provide a biocompatible environment for cell adhesion, proliferation, and differentiation and match the mechanical properties of native bone tissue. In this work, we fabricated porous polyetherimide (PEI) scaffolds using a three-dimensional (3D) printing system, and the pore size was set as 800 μm. The morphology of 3D PEI scaffolds was characterized by the scanning electron microscope. To investigate the mechanical properties of the 3D PEI scaffold, the compressive mechanical test was performed via an electronic universal testing system. For the in vitro cell experiment, bone marrow stromal cells (BMSCs) were cultured on the surface of the 3D PEI scaffold and PEI slice, and cytotoxicity, cell adhesion, and cell proliferation were detected to verify their biocompatibility. Besides, the alkaline phosphatase staining and Alizarin Red staining were performed on the BMSCs of different samples to evaluate the osteogenic differentiation. Through these studies, we found that the 3D PEI scaffold showed an interconnected porous structure, which was consistent with the design. The elastic modulus of the 3D PEI scaffold (941.33 ± 65.26 MPa) falls in the range of modulus for the native cancellous bone. Moreover, the cell proliferation and morphology on the 3D PEI scaffold were better than those on the PEI slice, which revealed that the porous scaffold has good biocompatibility and that no toxic substances were produced during the progress of high-temperature 3D printing. The osteogenic differentiation level of the 3D PEI scaffold and PEI slice was equal and ordinary. All of these results suggest the 3D printed PEI scaffold would be a potential strategy for bone tissue engineering.


2021 ◽  
Vol 8 ◽  
Author(s):  
Zixuan Xiong ◽  
Wenbin Liu ◽  
Hu Qian ◽  
Ting Lei ◽  
Xi He ◽  
...  

Polycarbonate (PCL) has been widely used in tissue engineering, but its hydrophobicity and low biological activity limit its further promotion and application. By adding nanoparticles, the hydrophilicity and biological activity of PCL can be improved. In this study, different amounts of Ta (1–10%wt) were added to PCL, and then their mechanical and biological properties were studied in vitro. XRD found that 5%Ta-PCL has the highest crystallinity. At the same time, cell experiments CCK8, cell adhesion, osteogenic differentiation, and osteogenesis related gene expression showed that Ta can enhance the mechanical and biological properties of PCL, while 5% Ta-PCL showed the best mechanical and biological properties. This composite of tantalum and PCL could have a clinical potential for orthopedic implants.


Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3583 ◽  
Author(s):  
Martina Doubkova ◽  
Ivana Nemcakova ◽  
Ivan Jirka ◽  
Vitezslav Brezina ◽  
Lucie Bacakova

Silicalite-1 is a purely siliceous form of zeolite, which does not contain potentially harmful aluminum in its structure as opposed to ZSM-5 aluminosilicate types of zeolite. This paper reports on a study of a silicalite-1 film, deposited on a silicon Si(100) substrate, as a potential anti-corrosive and biocompatible coating for orthopaedic implants. Silicalite-1 film was prepared in situ on the surface of Si(100) wafers using a reaction mixture of tetrapropyl-ammonium hydroxide (TPAOH), tetraethyl-orthosilicate (TEOS), and diH2O. The physico-chemical properties of the obtained surface were characterized by means of X-ray photoelectron spectroscopy, water contact angle measurement, atomic force microscopy, and scanning electron microscopy. The biocompatibility was assessed by interaction with the MG-63 cell line (human osteosarcoma) in terms of cell adhesion, morphology, proliferation, and viability. The synthesized silicalite-1 film consisted of two layers (b- and a, b-oriented crystals) creating a combination of micro- and nano-scale surface morphology suitable for cell growth. Despite its hydrophobicity, the silicalite-1 film increased the number of initially adhered human osteoblast-like MG-63 cells and the proliferation rate of these cells. The silicalite-1 film also improved the cell viability in comparison with the reference Si(100) substrate. It is therefore a promising candidate for coating of orthopaedic implants.


2020 ◽  
Vol 6 (1) ◽  
pp. 57-69
Author(s):  
Amirhosein Fathi ◽  
Farzad Kermani ◽  
Aliasghar Behnamghader ◽  
Sara Banijamali ◽  
Masoud Mozafari ◽  
...  

AbstractOver the last years, three-dimensional (3D) printing has been successfully applied to produce suitable substitutes for treating bone defects. In this work, 3D printed composite scaffolds of polycaprolactone (PCL) and strontium (Sr)- and cobalt (Co)-doped multi-component melt-derived bioactive glasses (BGs) were prepared for bone tissue engineering strategies. For this purpose, 30% of as-prepared BG particles (size <38 μm) were incorporated into PCL, and then the obtained composite mix was introduced into a 3D printing machine to fabricate layer-by-layer porous structures with the size of 12 × 12 × 2 mm3.The scaffolds were fully characterized through a series of physico-chemical and biological assays. Adding the BGs to PCL led to an improvement in the compressive strength of the fabricated scaffolds and increased their hydrophilicity. Furthermore, the PCL/BG scaffolds showed apatite-forming ability (i.e., bioactivity behavior) after being immersed in simulated body fluid (SBF). The in vitro cellular examinations revealed the cytocompatibility of the scaffolds and confirmed them as suitable substrates for the adhesion and proliferation of MG-63 osteosarcoma cells. In conclusion, 3D printed composite scaffolds made of PCL and Sr- and Co-doped BGs might be potentially-beneficial bone replacements, and the achieved results motivate further research on these materials.


2016 ◽  
Vol 36 (8) ◽  
pp. 771-784 ◽  
Author(s):  
Tejinder Kaur ◽  
Arunachalam Thirugnanam ◽  
Krishna Pramanik

Abstract Poly(vinyl alcohol) reinforced with nanohydroxyapatite (PVA-nHA) composite scaffolds were developed by varying the nHA (1%, 2%, 3%, 4%, and 5%, w/v) composition in the PVA matrix by solvent casting technique. The developed composite scaffolds were characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and contact angle measurement. The stability of the composite scaffolds in physiological environment was evaluated by swelling and degradation studies. Further, these composite scaffolds were tested for in vitro bioactivity, hemolysis, biocompatibility, and mechanical strength. SEM micrographs showed a homogenous distribution of nHA (3%, w/v) in the PVA matrix. XRD and ATR-FTIR analysis confirmed no phase contamination and the existence of the chemical bond between PVA-nHA at approximately 2474 cm-1. PVA-nHA composite scaffolds with 3% (w/v) concentration of nHA showed nominal swelling and degradation behavior with good mechanical strength. The mechanical strength and degradation properties of the scaffold above 3% (w/v) of nHA was found to deteriorate, which is due to the agglomeration of nHA. The in vitro bioactivity and hemolysis studies showed improved apatite formation and hemocompatibility of the developed scaffolds. In vitro cell adhesion, proliferation, alkaline phosphatase activity, and Alizarin red S staining confirmed the biocompatibility of the composite scaffolds.


Author(s):  
He Xu ◽  
Yan Xu ◽  
Peiyuan Wang ◽  
Hongpeng Yu ◽  
Ozoemena Anthony Ani ◽  
...  

Purpose The purpose of this paper is to explore a novel measurement approach for wheel-terrain contact angle using laser scanning sensors based on near-terrain perception. Laser scanning sensors have rarely been applied to the measurement of wheel-terrain contact angle for wheeled mobile robots (WMRs) in previous studies; however, it is an effective way to measure wheel-terrain contact angle directly with the advantages of simple, fast and high accuracy. Design/methodology/approach First, kinematics model for a WMR moving on rough terrain was developed, taking into consideration wheel slip and wheel-terrain contact angle. Second, the measurement principles of wheel-terrain contact angle using laser scanning sensors was presented, including “rigid wheel - rigid terrain” model and “rigid wheel - deformable terrain” model. Findings In the proposed approach, the measurement of wheel-terrain contact angle using laser scanning sensors was successfully demonstrated. The rationality of the approach was verified by experiments on rigid and sandy terrains with satisfactory results. Originality/value This paper proposes a novel, fast and effective wheel-terrain contact angle measurement approach for WMRs moving on both rigid and deformable terrains, using laser scanning sensors.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bochun Xu ◽  
Nan Zou ◽  
Yunhao Jia ◽  
Chao Feng ◽  
Jiajia Bu ◽  
...  

Purpose The purpose of this paper is to study the effect of micro-nano surface texture on the corrosion resistance of a titanium alloy and investigate the correlation between corrosion resistance and hydrophobicity. Design/methodology/approach The surface of the Ti6Al4V alloy was modified by laser processing and anodizing to fabricate micro-pits, nanotubes and micro-nano surface textures. Afterward, the surface morphology, hydrophobicity and polarization curve of the samples were analyzed by cold field scanning electron microscopy, contact angle measurement instruments and a multi-channel electrochemical workstation. Findings The micro-nano surface texture can enhance the hydrophobicity of the Ti6Al4V surface, which may lead to better drag reduction to ease the friction of implants in vivo. Nevertheless, no correlation existed between surface hydrophobicity and corrosion resistance; the corrosion resistance of samples with nanotubes and high-density samples with micro-nano surface texture was extremely enhanced, indicating the similar corrosion resistance of the two. Research limitations/implications The mechanism of micro-dimples on the corrosion resistance of the micro-nano surface texture was not studied. Practical implications The density of micro-pits needs to be optimized to guarantee excellent corrosion resistance in the design of the micro-nano surface texture; otherwise, it will not fulfill the requirement of surface modification. Originality/value The influence of the micro-nano surface texture on the corrosion resistance, as well as the relationship between hydrophobicity and corrosion resistance of the titanium alloy surface, were systematically investigated for the first time. These conclusions offer new knowledge.


2007 ◽  
Vol 342-343 ◽  
pp. 353-356 ◽  
Author(s):  
Jung Bok Lee ◽  
Seong Mi Yu ◽  
Sang Gil Lee ◽  
Jae Bong Choi ◽  
Jeong Koo Kim

PLGA (75:25)/hydroxyapatite (HA) composite films were fabricated by solvent-casting method to investigate the effect of various hydroxyapatite content ratio to the PLGA film for cellular attachment and proliferation. Mechanical property of the composite film was characterized by tensile test. The ultimate tensile strength of 10% HA content film was two folds higher than control group. The surface of the film was characterized by contact angle measurement. The PLGA/HA composite film was more hydrophilic than control film. In vitro chondrocyte responses to the composite films were measured by cellular attachment and proliferation test. The attached and proliferated cells were significantly higher on PLGA/HA (10%) composite film than control group (1.44 times higher in attachment test and 1.31 times higher for 6th-day at culture in proliferation assaying, p<0.05). Base on these finding, the PLGA/HA (10%) composite was effective for the cell attachment for the initial stage of cultivation and cell proliferation.


2009 ◽  
Vol 1187 ◽  
Author(s):  
Charles Andrew Collier ◽  
Julien M. Paillard ◽  
Athina E. Markaki ◽  
James A. Curran ◽  
Helen J Griffiths ◽  
...  

AbstractThe surface topology and composition of prosthetic implant materials affect cell responses and are therefore important design features. Plasma electrolytic oxidation (PEO) is a surface modification technique that can be used to produce oxidized surfaces with various surface properties. In this work, Ti-6Al-4V was PEO processed to give two surfaces with different morphologies but similar chemical composition. Surface characteristics were assessed using X ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, stylus profilometry and contact angle measurement.In vitro culture of human foetal osteoblasts (HOB) was performed on the surfaces, to examine cell responses to them. Cellular proliferation, morphology and differentiation were examined, using the AlamarBlue assay, SEM imaging and an alkaline phosphatase (ALP) activity assay respectively. Additionally, the individual effects of oxides present in the PEO processed surfaces (rutile and anatase) on the cells were examined, by binding them in powder form to produce surfaces with similar morphology, but different composition.Changes in the topology and chemistry of the surfaces affected osteoblast response. HOB proliferated more on the rougher PEO surface, and also displayed greater ALP activity. Also, cells responded differently to surfaces containing just rutile or anatase, indicating that the chemical phase of titanium oxide is of consequence for implant design.


2009 ◽  
Vol 610-613 ◽  
pp. 1011-1016 ◽  
Author(s):  
Yan Mei Chen ◽  
Ting Fei Xi ◽  
Yu Dong Zheng ◽  
Yi Zao Wan

The nanocomposite of nano-hydroxyapatite/bacterial cellulose (nHA/BC) obtained by depositing in simulated body fluid (SBF), incorporating their excellent mechanical and biological properties, is expected to have potential applications in bone tissue engineering. However, the biological response evaluation of biomaterials is required to provide useful information to improve their design and application. In this article, the in vitro cytotoxicity of composites nHA/BC as well as its degradation residues was studied. Scanning electron microscopy (SEM) was used to observe the morphology of original materials and their degradation residues. The degree of degradation was evalued by measuring the concentration of reducing sugar (glucose) by ultraviolet spectrophotometer. Bone-forming osteoblasts (OB) and infinite culture cell line L929 fibroblasts were used to measure the cytotocixity of materials with MTT assay. Both kinds of cells in infusion proliferate greatly in a normal form and their relative growth rate (RGR) exceeds by 75%, which shows the cytotoxicity of materials is graded as 0~1, according to the national standard. Nevertheless, bone-forming OB cells, as a kind of target cells, are more susceptive on the cytotoxicity than infinite culture fibroblast cells L929. The results suggest the nanocomposite of nHA/BC without cytotoxicity is greatly promising as a kind of scaffold materials for bone tissue engineering and tissue functional cells are more suited to evaluate the cytotoxicity of biomedical materials.


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