Double-Network Hydrogels for Intraoral Ultrasound Imaging

• Author / Creator

  Yi, Jiaqiang

• Ultrasound imaging has great potential in intraoral diagnosis, due to its portability, low cost, and low safety risks. A couplant is normally placed between transducers and tissues for better ultrasound image quality. If applied intraorally, the couplants should possess good stability in water, robust mechanical properties, as well as good affinity to transducers and tissues. However, commercial couplants, such as Aquaflex (AF), are designed for external use and cannot fulfill these requirements. With great similarity to the extracellular structure, excellent mechanical properties, and numerous commercialized biomedical applications, double-network tough hydrogels could act as the potential candidate for couplants. In this thesis, a review of the ultrasound process and the defects of commercial couplants, biomedical applications of hydrogels, and mechanisms to synthesize tough hydrogels are presented first. Methods to quantify mechanical properties, friction properties, adhesion properties, ultrasound properties, and biocompatibility are explained next. Then, two types of double-network (DN) hydrogels and their application in intraoral ultrasound imaging are explored.
  In the first theme, Polyacrylamide/Alginate (PAM/Alginate) double-network hydrogels were evaluated for intraoral ultrasound imaging via a comprehensive comparison of physical, mechanical, frictional and ultrasound properties to AF. The PAM/Alginate DN hydrogel not only possesses better stability in water as well as improved mechanical properties and higher coefficients of friction than AF but also can provide similar ultrasound image quality as AF does. Moreover, the PAM/Alginate DN hydrogel shows lower cytotoxicity to both cancer (Hela) and fibroblast cells (MRC-5). With all these significant features, PAM/Alginate DN hydrogels serve as a proof-of-concept ultrasound couplant with great potential in intraoral ultrasound imaging.
  In the second theme, inspired by the mussel adhesion mechanism, we explored a poly(vinyl alcohol)-polyacrylamide-polydopamine (PVA-PAM-PDA) hydrogel synthesized by incorporating PDA into the PAM-PVA double-network for intraoral ultrasound imaging. The hydrogel not only maintains good stability in water and superior mechanical properties but also can adhere to different substrates (metal, glass, and porcine skin) without losing the original adhesiveness after multiple adhesion–strip cycles. Besides, when applied to image porcine mandibular incisor, it could provide a similar ultrasound image quality as AF does. With these features, such hydrogel can serve as the candidate for ultrasound couplant in intraoral ultrasound imaging.
  This work has explored the application of double-network hydrogels to intraoral ultrasound imaging and provided useful insights into the development of multifunctional hydrogel-based interfaces between human tissues and medical devices for health monitoring and disease diagnosis applications. Via a comprehensive comparison of the above-mentioned properties to AF, we have expanded the application of double-network hydrogels to intraoral ultrasound imaging as the candidates for couplants.

• Subjects / Keywords

  • Ultrasound imaging
  • Double-network hydrogel
  • Intraoral diagnosis
  • Adhesion
  • Frictional properties

• Graduation date

  Fall 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-ht8s-sp50

• License

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