Advisor(s)

Vinoy Thomas

Committee Member(s)

Andrew Wood
Carmen Scholz
Eugenia Kharlempieva
Robin Foley
Yogesh Vohra

Document Type

Dissertation

Date of Award

1-27-2026

Degree Name

Doctor of Philosophy (PhD)

School

School of Engineering

Department

Materials Science

Abstract

Bio-integration, specifically osseo-integration of bone implants and scaffolds, are vital for the success of implants and bone tissue engineering (BTE). Calcification can be defined as the deposition of calcium compounds as either calcium phosphate(CaP) minerals consisting of hydroxyapatite(HAP) or CaP salts. The significance of the variety of phases of CaP is that mature bone matrix is composed of 65% CaP mineral. Many investigators have attempted to model the natural matrix by producing materials containing calcium phosphate in both amorphous CaP or in the more crystalline HAP form, with biomaterials (both synthetic and biological). Biomimetic CaP formation is a sign of bioactivity of polymeric biomaterials and scaffolds. Polymeric scaffolds are a possible solution due to characteristics of biocompatibility, tunable biodegradation, and easily adjustable mechanical properties. However, polymeric scaffolds have shown problems when it comes to bioactivity and osteo-integrative capabilities. Low temperature plasma (LTP) processing of polymeric scaffolds is a possible solution to both requirements. LTP allows for surface chemistry of scaffolds to be changed without causing degradation to the bulk scaffold or lowering the mechanical properties of the scaffold. The question is can LTP independently influence bioactivity? Bioactivity has been measured in the past by a materials capability to mineralize bone like apatite or some phase of calcium phosphate (CaP). Experimentally then, if the scaffold could mineralize CaP in vivo using LTP, where it could not before, then LTP is a process that can be used to optimize scaffolds by maintaining the mechanical properties, improving in vitro response, and influence the surface chemistry of the scaffold. While calcification is favorable for bone implants and scaffolds, it is an undesirable phenomenon for blood contacting implants such as heart valve materials, vascular stent, and grafts. Calcification is also one of the major causes for the catastrophic failure of polyurethane cardiac-assist devices and bioprosthetic valves, as calcification results in the loss of the flexibility of polyurethane biomaterials, thereby causing their mechanical failure and eventual degradation. The advantage of LTP processing is that by selecting suitable plasma-precursors, tuning the polymeric biomaterials surface for or against calcification is possible.

Keywords

Biomineralization;Calcium Phosphate;Plasma;Polymer;Scaffolds

ProQuest Publication Number

32285370

ISBN

9798273382121

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