Advances in Biomaterials for 3D Printing of Scaffolds and Tissues: Session I
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Biomaterials Committee
Program Organizers: Changxue Xu, Texas Tech University; Jun Yin, Zhejiang University; Zhengyi Zhang, Huazhong University of Science and Technology; Yifei Jin, University of Nevada Reno; Heqi Xu, Texas Tech University
Tuesday 8:00 AM
March 21, 2023
Room: Sapphire 400B
Location: Hilton
Session Chair: Md Shahriar, Texas Tech University
8:00 AM Invited
Electrohydrodynamic 3D Printing of Aqueous Solutions: Ander Reizabal1; 1BCMaterials - Basque Center for Materials, Applications and Nanostructures
Among the different electrohydrodynamic processes, melt electrowriting (MEW), has achieved a great development for biomedical materials design, because of its ability to generate macro-structures with complex micro-features. Aqueous solutions electrowriting conserve the potential for high-resolution microscale printing but also bring new opportunities for materials processing. To boost its visibility, current research proposes a cryogenic stage that allows the freezing of EHD jets, to facilitate the 3D growth of structures. Using silk fibroin highly viscous solutions, microfibers of around 30 µm have been successfully stacked one-each other to achieve complex macrostructures. The obtained scaffolds show excellent biological response and capacities for cell guidance. In addition, porous fibers present micro-channels that invite us to explore their potential in different fields. With this approach, the suitability of a new type of 3D-printed material is achieved, as the time that the complexity and requirements of the new technology are tested.
8:30 AM
Development of Propolis Modified Scaffolds for Tissue Engineering: Alex Ossa1; Alejandro Pelaez2; Claudia Garcia3; 1Universidad Eafit; 2Universidad Cooperativa de Colombia; 3Universidad Nacional de Colombia
The development of scaffolds for bone tissue engineering requires mechanical responses and bacterial resistance corresponding to those of the surrounding native bone tissue to avoid rejection and increase feasibility of the treatment. In pursuit of these important requirements researchers have recently use the capabilities of additive manufacturing to produce different geometries comparable to those of bone. However, despite of important advances, still remains a limitation related with the anti-bacterial capabilities of the scaffolds produced. Here, we used additive manufacture to produce scaffolds with different geometries by using PLA and PCL with and without HAP particles to tune the mechanical response to that of bone. Further, bee Propolis was used to improve the anti-bacterial response of the scaffolds.
8:50 AM
Effects of Corona Treatment on Cellular Attachment and Morphology on Polydimethylsiloxane Micropillar Substrates: Md Shahriar1; Eduardo Pena1; Jiachen Liu1; Zhengyi Zhang2; Changxue Xu1; 1Texas Tech University; 2Huazhong University of Science and Technology
PDMS, a silicon-based elastomer is a widely used material in biomedical and microfluidic research. However, the intrinsic hydrophobic nature of PDMS hinders cellular attachment on the PDMS substrates. Corona discharge is widely used as a facile and robust method of surface treatment of PDMS substrates. This study investigates the effects of corona discharge on cellular attachment and morphology. With the increase of corona discharge time, the hydrophobic methyl groups are converted into polar silanol groups which significantly improves surface wettability and surface energy, as well as the corresponding cellular attachment and aspect ratio. However, prolonged corona discharge deteriorates surface wettability and cellular attachment due to crack formation. Higher water contact angle and reduced cell attachment are observed on thinner (0.1 mm) and thicker (1.5mm) samples. The optimal conditions observed are 0.5 mm sample thickness and corona discharge time of 60 seconds showing the best cellular attachment and morphology.
9:10 AM
Fabrication of Hierarchically Porous 316L Stainless Steel Scaffolds by Freeze Casting and 3D-printed Sacrificial Templating Techniques: Cheng Tsai1; Kuan-Cheng Lai1; Haw-Kai Chang1; Po-Yu Chen1; 1National Tsing Hua University
The hierarchical and lightweight structure is a strategy commonly employed by living creatures to adapt to the environment. In recent years, porous alloys with varying scales of pores (macro-, micro-, nano-) and hierarchical structures have drawn growing attention in materials research fields owing to their unique properties. In this study, 316L stainless steel was selected as it is one of the commonly used metallic biomaterials due to its good biocompatibility, low price, excellent corrosion resistance, and proper strength. By integrating freeze casting method and stereolithography (SLA) additive manufacturing technology, a dual templating process was developed to fabricate hierarchical millimeter/micrometer scale lightweight metal-/alloy-based scaffolds with proper compressive mechanical properties and tunable functional applicability. The porosity and elastic modulus of hierarchical porous 316L stainless steel scaffolds are in the range of 62-65% and 370-460 MPa, respectively. The novel lightweight, hierarchically porous 316L stainless steel scaffolds can be potentially applied in biomedical fields.
9:30 AM Break
9:50 AM
High Speed and High-Resolution 3D Printing of Self-healing and Ion-conductive Hydrogels via µCLIP: Wenbo Wang1; Siying Liu1; Luyang Liu1; Xiangfan Chen1; 1Arizona State University
Ion-conductive self-healing (SH) hydrogels have received significant attention as biomaterials benefiting from the behavior of living tissue to broaden the design of health monitoring systems and soft robotics with autonomously SH capabilities. Herein, we propose a high-resolution 3D printing of ion-conductive SH hydrogel realized by micro-continuous liquid interface production (µCLIP). Once damage occurs, the 3D printed hydrogel fully recovers the mechanical properties after 12h at room temperature without external trigger. These novel hydrogels are designed with interpenetrating polymer networks (IPN) based on physical-crosslinked poly(vinyl alcohol) networks combined with chemical/ionic crosslinked networks formed by acrylic acid and ferric chloride. In addition, the ionic conductivity and high stretchability of the hydrogel enables strain and pressure sensing capabilities that could be applied as health monitoring system or soft robotics. This novel approach of high-resolution 3D printing of SH hydrogels in complex structures will provide a promising development of future biomedical devices.
10:10 AM Cancelled
Inkjet Bioprinting of Cell-laden Biomaterials for Constructing 3D Multicell and Multimaterial Scaffolds: Dengke Zhao1; Jun Yin1; 1Zhejiang University
Inkjet bioprinting, as a promising dropwise biofabrication technology, favors printing of cell-laden biomaterials (aka bioink) to recapitulate 3D tissues with heterogeneity and component multiplicity. Here, being the premise of inkjet bioprinting, the droplet formation process of viscoelastic ink (for most solutions of biomaterials) was first investigated focusing on its dynamics and performance. Four distinct droplet formation regimes were identified, and a process dynamics-related dimensionless number (Wj) was proposed to construct an operating phase diagram on droplet formation and quantify the transition of droplet formation regimes. Furthermore, a 3D inkjet bioprinting process and matching bioink formulations were developed, where the bioink was printed based on droplet-droplet impact to fabricate high-fidelity 3D hydrogel structures, followed by post-processing to attain proper microenvironments for the encapsulated cells. Moreover, inkjet bioprinting of 3D heterogeneous tissue with multiple cells and materials was further achieved.
10:30 AM
Cell-Laden Bioink Circulation-Assisted Inkjet-Based Bioprinting to Mitigate Cell Sedimentation and Cell Aggregation: Jiachen Liu1; Md Shahriar1; Changxue Xu1; 1Texas Tech University
Bioink, as the building block for 3D bioprinting, generally composes of solution of biological materials and living cells. During inkjet bioprinting, since the gravitational force acting on cells is usually greater than the buoyant force provided by the solution of biological materials, cells sediment to form cell aggregates through cell-cell interaction. Cell sedimentation and cell aggregation results in highly nonuniform cell distribution within the bioink reservoir, undermining the printing performance and reliability in several aspects such as nozzle performance, droplet formation, and post-printing cell output, which is recognized as a significant challenge in achieving reliable bioprinting. To alleviate this problem, this study proposes a bioink circulation system to assist inkjet bioprinting without manipulation of bioink properties. Results demonstrate a high effectiveness of the proposed system in mitigating cell sedimentation and cell aggregation, therefore improving the bioprinting performance and reliability.