Text

theses

ETD graduate

Organ failure occurs when a bodily system is unable to perform tasks that are necessary for survival, and they can be caused by any significant change to internal body conditions, ranging from chronic diseases to sudden injuries. Long term or irreversible organ failure is most effectively treated with the transplantation of a donated replacement organ as a substitute for the diseased system. The number of patients who require an organ transplant significantly outnumbers available replacements both in the US and worldwide, resulting in many patients dying while on transplant waiting lists. Because organ donations cannot keep up with organ failure prevalence, there exists a need for other avenues of obtaining functional replacements.

3D biofabrication technologies have grown significantly in recent years and show promise as powerful tools in the creation of customizable and biocompatible organ components and even entire organ structures. However, materials that provide the ideal bioactivity necessary for development of fully functional artificial organs are rarely usable in conventional 3D biofabrication methods due to their incompatibility with high temperatures and inability to maintain their configuration after their extrusion. Recent advancements in a 3D biofabrication technology known as freeform reversible embedding of suspended hydrogels (FRESH), which uses a gelatin microbead support bath to maintain structural integrity, may provide an avenue for using these materials in more versatile ways, but published literature pertaining to this technique is lacking in detail in both material and process. Published material pertaining to FRESH printing also lacks description of how variations in processing steps and material properties affect experimental results, only reporting the specific steps that led to significant results. These information gaps make it difficult for new researchers to recreate and build upon what has already been developed. In order for FRESH printing to progress to the point where it is usable in clinics for creating artificial transplant organs, it is necessary for a full understanding of the technology and its protocols to be accessible.

In this thesis, the beginnings of a detailed FRESH printing protocol are established. It is determined that low blend time in the creation of the gelatin slurry used in FRESH results in a nonuniform support bath that is unusable in printing. This study also produced a protocol for creating a collagen-based bioink using customizable materials and found that existing protocols for FRESH printing using collagen inks may not be broadly effective. Lab closures cause by the COVID-19 pandemic prevented further analysis and protocol building, but a foundation has been laid for an accessible understanding of FRESH printing technologies.

ETD_11153

M.S.

Includes bibliographical references

doi:10.7282/t3-tdec-yf78

The author owns the copyright to this work.