Description
- Abstract:
- Today bone defects such as bone fractures, osteoporosis or bone cancers represent a common and significant clinical problem. However, traditional micron size implant materials have many shortcomings, including insufficient osseointegration, severe foreign body response, etc., which may lead to implant failure. Therefore, the objective of this dissertation was to design, synthesize, and fabricate a series of biomimetic nanostructured scaffolds or coating materials based on rosette nanotubes (RNTs), nanocrystalline hydroxyapatite (HA) as well as a biocompatible hydrogel (specifically, poly(2-hydroxyethyl methacrylate)) and, more importantly, to evaluate their cytocompatibility for improved bone tissue engineering, orthopedic and vascular applications. The RNTs are a class of biologically-inspired nanomaterials obtained through the self-assembly of DNA motifs (Guanine^Cytosine) in aqueous solutions. They have tailorable amino acids (such as K) and peptide side chains and biomimetic features similar to collagen in bone. In this study, the cell-adhesive RGD and KRSR peptides modified RNTs and different sizes of nanocrystalline HA were synthesized and fabricated into hydrogels or coated on conventional implant materials (titanium). The results of this in vitro study demonstrated for the first time that the RNT hydrogel composites significantly enhanced osteoblast (bone-forming cell) functions (such as adhesion, proliferation and differentiation), which suggested the excellent cytocompatibility of RNTs for bone tissue engineering applications. Furthermore, the work showed that nanocrystalline HA/RNTs in hydrogel and on titanium also exhibited good cytocompatibility for orthopedic applications. Moreover, KRSR modified RNTs coated on titanium selectively improved osteoblast adhesion (other cell such as fibroblast adhesion was not improved). After investigating the possibly underlying mechanisms of the observed favorable cell functions on RNTs, this study revealed that the controllable surface chemistry and nanostructured features of RNTs created a cell-favorable environment to improve osteoblast functions, thus, making them intriguing materials for further study in orthopedic applications. Lastly, since growing new blood vessels was important for bone growth, the study also investigated the endothelialization on RNT coatings. The result demonstrated that endothelial cell adhesion and proliferation were greatly enhanced on RNT coatings, thus, making them promising for vascular stent and orthopedic applications.
- Notes:
- Thesis (Ph.D.) -- Brown University (2009)
Access Conditions
- Rights
- In Copyright
- Restrictions on Use
- Collection is open for research.
Citation
Zhang, Lijie,
"Biologically Inspired Rosette Nanotube Nanocomposites for Bone Tissue Engineering, Orthopedic and Vascular Applications"
(2009).
Biomedical Engineering Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z0765CS2
Relations
Collection:
-
Biomedical Engineering Theses and Dissertations
Theses and Dissertations for the Biomedical Engineering department....