Thesis
Light-based 3D printed biomaterials with tunable properties using biosourced photoinitiators
University of Iowa
Master of Science (MS), University of Iowa
Spring 2025
DOI: 10.25820/etd.007876
Abstract
Light-based 3D printing is a promising additive manufacturing technique for fabricating engineered tissue mimics that recapitulate the complex architecture of biological tissues. This type of 3D printing relies on photopolymerization, which is a process that provides inherent spatial and temporal control and thus makes resolving features on meso- and micro-scales possible. However, several barriers limit the use of light-based 3D printing in biomedical applications. Firstly, few photoinitiators, the light-absorbing molecules that drive the polymerization reaction, are cytocompatible. Secondly, it is unknown how material properties such as Young’s modulus and swelling can be modulated using printing parameters. In this work, we use direct light processing (DLP) and two photon polymerization (TPP) and two model monomers—a combinatory hydroxyethyl methacrylate and urethane dimethacrylate or 6-hexanediol diacrylate—to assess the efficacy of a novel biosourced photoinitiator system (PhInS) comprised of curcumin and N-phenyl glycine. We compare its efficacy to the commercial photoinitiator, Irgacure 369, which is a known endocrine disruptor. Additionally, we extracted the Young’s modulus (stiffness) from TPP structures to study how printing parameters influence final material properties. Through our work, we found our novel PhInS can be used for both DLP and TPP. Further, we established key relationships between printing parameters through linear and non-linear regression models. For DLP, we found that as light intensity increased, needed exposure time decreased. A similar connection was identified for TPP, where increased laser power allowed for higher scanning speeds (the inverse of exposure time). We also found that for TPP structures, changing the laser power or scanning speed changes the stiffness of the polymerized materials, with increased laser power leading to less stiff materials while increased scanning speed led to stiffer materials. Together, we show the capabilities of biosourced photoinitiators for light-based 3D printing and how altering printing parameters allows for the creation of tunable materials. This work lays groundwork for the development of precisely controlled photomanufactured tissue mimetics, without the use of toxic materials.
Details
- Title: Subtitle
- Light-based 3D printed biomaterials with tunable properties using biosourced photoinitiators
- Creators
- Hailey McCoy-Munger
- Contributors
- Kristan Worthington (Advisor)Edward Sander (Committee Member)Xuan Mu (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Biomedical Engineering
- Date degree season
- Spring 2025
- DOI
- 10.25820/etd.007876
- Publisher
- University of Iowa
- Number of pages
- x, 41 pages
- Copyright
- Copyright 2025 Hailey McCoy-Munger
- Grant note
- This work was funded by the NSF (2142246). The author would like to acknowledge Andre V. James for Fourier transform infrared spectroscopy and Jacob J. Cannon for curcumin-N-phenyl glycine absorbance spectrum data collection. The author would also like to acknowledge use of the University of Iowa Central Microscopy Research Facility, a core resource supported by the University of Iowa Vice President for Research, and the Carver College of Medicine.
- Language
- English
- Date submitted
- 04/29/2025
- Description illustrations
- Illustrations, tables, graphs, charts
- Description bibliographic
- Includes bibliographical references (pages 37-41).
- Public Abstract (ETD)
3D printing has emerged as a powerful tool for creating engineered tissue mimetics. Compared to other types of 3D printing, light-based 3D printing provides superior control of when and where the reaction occurs, which makes it particularly advantageous for fabricating complex structures and replicating biological tissue. Several types of light-based 3D printing have been used in biomedical research, but their use is limited due to a few barriers. First, many of the initiator molecules used in traditional resins, which are necessary for light-based 3D printing, are toxic to living things. Second, properties of the materials, such as stiffness, are not easily controllable. In this work, we use a novel biologically sourced initiator system for two types of light-based 3D printing and compare its efficacy to a commercial analog. Through finding the optimal printing parameters, we were able to define mathematical relationships that can be used to predict which printing parameters work best for a given resin. We also find the stiffness of high-resolution 3D printed structures created using the novel initiator across a range of printing parameters. We relate the stiffness to the printing parameters to demonstrate how the parameters can be used to tune material properties of the final structure. Together, we show that biologically sourced initiators can be used with light-based 3D printing to create structures with tunable stiffnesses. These results advance our understanding on how biologically sourced initiators and light-based 3D printing can be coupled to create non-toxic tissue mimetics or other devices for biology and medicine.
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Craniofacial Anomalies Research Center
- Record Identifier
- 9984831121802771
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