Abstract

Bacterial contamination of medical devices remains a threat to the success of many medical interventions. Oral administration of antibiotics is a convenient, non-invasive way to treat infections. Most orally administered drugs, however, encounter biochemical and biological barriers that reduce their bioavailability at the target site. Therefore, prophylactic physico- chemical changes of biomaterial surfaces are considered alternatives to inhibit bacterial aggregation and subsequent biofilm formation. Millions of years of evolution have enabled nature to develop micro-topographical surface features specifically designed to avoid bacterial attachment and colonization. Examples of such topographies can be seen on insect cuticles, plant leaves, and the feet of some reptiles. Most manufacturing techniques commonly used to create micro-topographical patterns suffer from limitations when adapted to large-scale medical device manufacturing environments. This dissertation examines aerosol jet printing as a manufacturing tool for the high-throughput production of antibacterial shark-skin patterns on polymer devices. This dissertation presents a comprehensive physics-based framework for bypassing exhaustive empirical tests currently needed to identify optimal printing conditions. The work in this dissertation is divided into three parts. In the first part, a two-dimensional computational fluid dynamics model is presented to explain the aerodynamic phenomena that dictate the morphology of aerosol jet-printed features. In the second part, a three- dimensional computational framework is devised to explain the role of machine parameters such as aerodynamic lens design, the density of the sheath gas, and the size of droplets in the aerosol stream in determining print resolution and quality. In the third part, insights from computational models are used to print antimicrobial shark-skin patterns on planar and non-planar polymer surfaces. Antibacterial studies with Escherichia coli are performed to test the antibacterial efficacy of silver nanoparticle-containing patterns to inhibit bacterial aggregation and proliferation. Finally, lactate dehydrogenase assays are carried out to evaluate the cytotoxicity of the patterned polymer devices.

Publication Date

4-2022

Document Type

Dissertation

Student Type

Graduate

Degree Name

Mechanical and Industrial Engineering (Ph.D)

Department, Program, or Center

Mechanical Engineering (KGCOE)

Advisor

Iris V. Rivero

Advisor/Committee Member

Denis R. Cormier

Advisor/Committee Member

Karin Wuertz-Kozak

Comments

This dissertation has been embargoed. The full-text will be available on or around 5/11/2023.

Campus

RIT – Main Campus

Available for download on Thursday, May 11, 2023

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