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Cellular, bacterial and humoral interactions with biomedical polymers under static and flow conditions

Brunstedt, Michael R.
http://rave.ohiolink.edu/etdc/view?acc_num=case1056993095

Abstract Details

1993, Doctor of Philosophy, Case Western Reserve University, Macromolecular Science.
Cellular, humoral, and bacterial interactions with biomedical polymers were studied under static and flow conditions using in vitro techniques. Static studies quantified in vitro endothelial cell attachment and proliferation as well as protein adsorption on polymethacrylate additive modified poly(ether urethane urea) (PEUU) films. Electron spectroscopy for chemical analysis showed additives to be surface active in the unhydrated state. Contact angle analysis suggested that, in water, hydrophilic additives at the interface rapidly reorient to expose hydrophilic moieties. Hydrophobic additives at the PEUU interface were displaced by the more hydrophilic PEUU chains and these films behaved similarly to unloaded films. Increased interfacial hydrophilicity caused by some of the additives correlated with enhanced protein adsorption and endothelial cell behavior on PEUU films. New additives were designed to increase interfacial hydrophilicity, and these additives often exhibited significantly better protein and endothelial cell behavior than did the polymethacrylate additives. Whole human blood, injected or preseeded with Staphyloccocus epidermidis, and cardiovascular materials were used in a recirculating system to address the questions of bacterial adhesion and persistence on biomater ials under flow conditions. Slime and non-slime forming S. epidermidis adhered avidly to nonsmooth materials. Protein adsorption levels in the presence of injected S. epidermidis correlated inversely to S. epidermidis adherence, implying that adherent bacteria block adsorbed proteins. Protein adsorption levels were highest on preseeded materials which adhered the highest numbers of bacteria. At least 70% of the bacteria on preseeded materials embolized during recirculation with human blood, implying that adsorption of proteins occurred to a remaining bacterial biofilm on the material. Whole blood white cell depletion and plasma C3a and fibrinopeptide A elevation in recirculated blood were largely independent of test conditions in the presence of bacteria. Conversely, whole blood platelet depletions and plasma thrombospondin concentrations were often significantly higher for respective materials in the presence of injected, slime forming S. epidermidis than for other bacterial conditions. Preseeded and injected slime and non-slime forming S. epidermidis activated humoral and cellular defense mechanisms, albeit to different degrees. These studies indicate that S. epidermidis meet two criteria of infection, bacterial adhesion and persistence, under all bacterial test conditions and for all materials tested.
James Anderson (Advisor)
247 p.
Cellular; bacterial; humoral interactions; biomedical polymers; static; flow

Recommended Citations

Citations

  • Brunstedt, M. R. (1993). Cellular, bacterial and humoral interactions with biomedical polymers under static and flow conditions [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1056993095

    APA Style (7th edition)

  • Brunstedt, Michael. Cellular, bacterial and humoral interactions with biomedical polymers under static and flow conditions. 1993. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1056993095.

    MLA Style (8th edition)

  • Brunstedt, Michael. "Cellular, bacterial and humoral interactions with biomedical polymers under static and flow conditions." Doctoral dissertation, Case Western Reserve University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1056993095

    Chicago Manual of Style (17th edition)

case1056993095
487
© 1993, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.