Nano and micro particles have steadily grown in interest for synthetic bone composite structures. Nano and micro sized calcium phosphates especially are of interest because of the osteoinductive behavior of calcium phosphate. Engineered composites incorporating polymers and ceramics, such as poly l-lactic acid (PLLA)/β-TCP, for bone tissue regeneration have been well investigated for their proliferative and osteoinductive abilities. Limited research has been done to thoroughly investigate the effects of various sized β-TCP particles on human mesenchymal stem cell behavior. Foreign bodies are known to elicit an inflammatory and cytotoxic response and several nano-particles are known to elicit cytotoxic and pro-inflammatory responses of mesenchymal stem cells. In this study, the modulation of adult human adipose-derived mesenchymal stem cell (hASC) behavior exposed to β-TCP, as functions of particle size, content and composition in a polymeric-ceramic scaffold system was investigated. The objectives of this work include the development and characterization of monolithic 3-D polymeric-ceramic structures using a modified unidirectional fabrication technique to investigate the cytotoxic, pro-inflammatory and osteogenic potential of PLLA-β-TCP composite on adult human stem cells. Characterization of PLLA-β-TCP composites showed that increasing β-TCP content the compressive strength decreases. Viability of hASCs over a 7 day exposure study showed increasing cytotoxicity with respect to increasing particle concentration regardless of size, although acute (24hr) cytotoxicity was more influenced by size. qPCR was used to measure the pro-inflammatory (IL-6) expression as well as early osteogenic differentiation (hALP). Results suggest there is a modulation in stem cell behavior as a function of β-TCP particle size, concentration and composite system.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-07272012-151912 |
| Date | 06 August 2012 |
| Creators | Terrell, Lekeith |
| Contributors | W. Todd Monroe, Daniel Hayes, Steven G. Hall |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-07272012-151912/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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