Advances in Biomaterials for 3D Printing of Scaffolds and Tissues: Advances in Biomaterials for 3D Printing of Scaffolds and Tissues II
Sponsored by: TMS Functional Materials Division, TMS Structural Materials 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

Monday 2:00 PM
February 28, 2022
Room: 201A
Location: Anaheim Convention Center

Session Chair: Heqi Xu, Texas Tech University; Jiachen Liu, Texas Tech University

2:00 PM
Development and 3D Printing of a Bioabsorbable Composite Material for Orthopaedic Applications: Cillian Thompson¹; Cristina Pascual-González¹; Guillermo Domínguez¹; Monica Echeverry-Rendón¹; Carlos González²; Javier Llorca²; ¹IMDEA Materials Institute; ²IMDEA Materials Institute & Technical University of Madrid
    This work shows the route to develop additively manufactured bioabsorbable composite materials for orthopaedic applications by combining Poly(L-D- Lactide) (PLDL) and Mg/Zn particles (~40ľm) of various volume fractions into 3D printable filaments to overcome the individual disadvantages associated with the bioabsorbable polymers and metals. Porous bioabsorbable bone scaffolds of various structural organisation (e.g. FCC, BCC) were developed and their mechanical, degradation, and cytocompatibility properties were determined. Degradation was evaluated through the mechanical tests of scaffolds that were immersed in simulated body fluids for various periods of time (up to 60 days) while cytocompatibility tests were carried out in line with ISO 10993-1 recommendations for both direct and indirect assays.

2:20 PM
Femto-second Laser Lithography of Fluorescent 2D/3D Nanostructures: Shobha Shukla¹; ¹IIT Bombay
    Bottom-up methods can be used to make large quantities of nanoparticles through a series of chemical reactions. However, top-down approaches are usually needed to synthesize complicated nanosystems. Electron beam lithography and focused ion beam lithography are two examples of top-down nanofabrication techniques. Like most top-down techniques, they are expensive, slow, and planar. This makes the task of building large-scale, three-dimensional functional structures difficult. Scaling-up nanofabrication is not a trivial task. Nonlinear optical effects can be used to pattern or grow polymeric and composite structures in three dimensions. Here, we will discuss usage of femtosecond-laser patterning as an alternative method of making three-dimensional nano and micro patterns for various applications. Femtosecond laser based microfabrication is scalable and can be used to manufacture large volumes of micro- and nanostructures quickly and inexpensively.

2:40 PM
Effects of Topographic Parameters on a Micropillar Surface on Cell Migration and Morphology: Srikumar Krishnamoorthy¹; Jiachen Liu¹; Heqi Xu¹; Zhengyi Zhang²; Changxue Xu¹; Md Shahriar¹; ¹Texas Tech University; ²Huazhong University of Science and Technology
    Guided cell migration refers to the engineering of local cell environment to specifically direct cell migration, and has important applications such as utilization in cell sorting and wound healing assays. Graded micropillar surfaces have been utilized for achieving guided cell migration. Topographic parameters such as micropillar diameter and spacing gradient may have effects on the morphology of attached cells. It is critical to understand this interaction between the cells and the underlying microscale structures. In this study, a graded micropillar substrate has been fabricated to investigate the effects of the microtopography on the cell morphology in terms of the cell aspect ratio and cell circularity. The results regarding interaction between the living cells and the underlying microscale topographic surfaces benefits better understanding of the formation and regeneration of tissues and organs.

3:00 PM
Synthesis and Characterization of Hydroxyapatite from Solid Mineral for Dental and Orthopedic Applications: Grace Oyatogun¹; Temitope Esan¹; Victor Abere¹; Chinenye Ibekwe¹; Kunle Oluwasegun¹; ¹Obafemi Awolowo University
    Limitations associated with bone grafts have prompted the need for bone graft substitutes, hence this work attempted to develop hydroxyapatite (HA) bone graft substitute for the treatment of bone injury. The HA was synthesized from limestone using aqueous precipitation method. Microstructural analysis was carried out using Scanning Electron Microscopy (SEM) and chemical analysis was carried out using Energy Dispersive Spectroscopy (EDS), Atomic Absorption Spectrophotometer (AAS), Fourier’s Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. Mechanical characterization was carried out using Vickers micro hardness tester and Instron universal tester. SEM findings revealed that the HA is porous while the chemical analysis affirmed that the sintered material is composed of calcium and phosphorus with an optimum hardness value of 742 HV at 9000C and compressive, tensile, hardness, fracture toughness and modulus of elasticity comparable with standard HA. Consequently, it will be a suitable bone graft substitute for dental and orthopaedic applications.