Abstract

Biofilms are responsible for the development of chronic infections, which are 10-1000 times more resistant to antimicrobial agents than two-dimensional (2D) planktonic culture. Traditionally, 2D planktonic cultures are used to study efficacy of antimicrobial treatments but 2D cultures have several shortcomings such as increased sensitivity to treatments, lack of complexity of the three-dimensional (3D) environment, limited host defense mechanisms, and lack the structural thickness of natural biofilms. Biofilm-related infections play a critical role in the delayed healing process of chronic skin wounds, and while treatments for chronic skin wounds exist, including negative pressure wound healing (NPWT), biofilm infections still prevail. Therefore, there is an increasing need for biorelevant 3D models that mimic natural biofilm formation to accurately test antimicrobial treatments. 3D bioprinting has emerged as a versatile method for the fabrication of 3D bio-architectures which mimic the structural, mechanical, and biological performance of native conditions. This work includes the development of 3D printed single and mixed species in vitro biofilm models and investigation into a treatment option for biofilm infected skin wounds. Results suggest that the addition of chitosan and zinc oxide nanoparticles into NPWT wound dressing inhibits biofilm growth and may be used as an antimicrobial wound dressing during negative pressure treatments. Additionally, a gelatin 3D printing bath was fabricated, characterized, and yielded biomimetic 3D biofilm models that could not otherwise be fabricated with low viscosity bioinks. With (1) nontraditional scaffold fabrication techniques for low viscosity bioinks, (2) enhanced understanding of the effect of biofilm maturation age on antimicrobial susceptibility, and (3) investigation into the interaction of mixed species models, 3D printed biofilms could provide in vitro infectious disease models for the discovery of new antibiofilm drugs and antimicrobial wound dressings and foams.

Library of Congress Subject Headings

Biofilms--Mathematical models; Infection--Treatment--Mathematical models; Three-dimensional printing; Wound healing

Publication Date

4-2024

Document Type

Dissertation

Student Type

Graduate

Degree Name

Mechanical and Industrial Engineering (Ph.D)

Department, Program, or Center

Mechanical Engineering

College

Kate Gleason College of Engineering

Advisor

Iris V. Rivero

Advisor/Committee Member

Denis Cormier

Advisor/Committee Member

Ehsan Rashedi

Comments

This dissertation has been embargoed. The full-text will be available on or around 5/20/2025.

Campus

RIT – Main Campus

Plan Codes

MIE-PHD

Download

Available for download on Tuesday, May 20, 2025

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