Methacrylate-Modified Gold Nanoparticles Enable Non-Invasive Monitoring of Photocrosslinked Hydrogel Scaffolds.

• Authors: Lan Li, Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, Materials Science and Engineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA.; Carmen J Gil, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.; Tyler A Finamore, Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, Materials Science and Engineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA.; Connor J Evans, Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, Materials Science and Engineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA.; Martin L Tomov, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.; Liqun Ning, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.; Andrea Theus, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.; Gabriella Kabboul, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.; Vahid Serpooshan, Emory University; Ryan K Roeder, Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, Materials Science and Engineering Graduate Program, University of Notre Dame, Notre Dame, IN 46556, USA.
• Journal Title: Adv Nanobiomed Res
• Volume: Volume 2, Number 7
• Publisher: (publisher) | 2022-07
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1002/anbr.202200022
• Subjects: Engineering, Aerospace; Engineering, Biomedical; Engineering, Mechanical
• Keywords: Computed Tomography; Gelatin Methacryloyl (GelMA) Hydrogel; Gold Nanoparticles; Photopolymerization; Tissue Engineering Scaffold

Abstract

Photocrosslinked hydrogels, such as methacrylate-modified gelatin (gelMA) and hyaluronic acid (HAMA), are widely utilized as tissue engineering scaffolds and/or drug delivery vehicles, but lack a suitable means for non-invasive, longitudinal monitoring of surgical placement, biodegradation, and drug release. Therefore, we developed a novel photopolymerizable X-ray contrast agent, methacrylate-modified gold nanoparticles (AuMA NPs), to enable covalent-linking to methacrylate-modified hydrogels (gelMA and HAMA) in one-step during photocrosslinking and non-invasive monitoring by X-ray micro-computed tomography (micro-CT). Hydrogels exhibited a linear increase in X-ray attenuation with increased Au NP concentration to enable quantitative imaging by contrast-enhanced micro-CT. The enzymatic and hydrolytic degradation kinetics of gelMA-Au NP hydrogels were longitudinally monitored by micro-CT for up to one month in vitro, yielding results that were consistent with concurrent measurements by optical spectroscopy and gravimetric analysis. Importantly, AuMA NPs did not disrupt the hydrogel network, rheology, mechanical properties, and hydrolytic stability compared with gelMA alone. GelMA-Au NP hydrogels were thus able to be bioprinted into well-defined three-dimensional architectures supporting endothelial cell viability and growth. Overall, AuMA NPs enabled the preparation of both conventional photopolymerized hydrogels and bioprinted scaffolds with tunable X-ray contrast for noninvasive, longitudinal monitoring of placement, degradation, and NP release by micro-CT.