Aspects of bone sugar biology : pectin nanocoatings of hard tissue implants

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>The improvement of implant biocompatibility is constantly under investigation. Titanium is a standard biomaterial that performs well in dental and orthopedic implantations. However, detrimental adverse effects resulting from e.g. biomaterial properties, inflammatory responses and surgical procedures occasionally occur. Coating the biomaterials aims at increasing the proportion of successful operations. </p><p>Pectins, large plant cell wall polysaccharides, are innovative, modifiable, and potentially anti-inflammatory candidates for biomaterial nanocoatings. In this thesis, covalently-grafted pectin fragments (modified hairy regions, MHRs) modified either <em>in vitro</em> (from apple) or <em>in vivo</em> (from potato) were tested. </p><p>Cell culture vessels and titanium substratum coated with the apple-MHRs, MHR-A and a further-tailored fragment type, MHR-B, were compared with controls for their ability to support proliferation and differentiation of osteoclasts and osteoblasts. Cells grew and differentiated on MHR-B and on the control surfaces; MHR-A did not perform well in these assays. Genetically-engineered potato MHRs did not support bone cell growth to the same extent as apple MHR-B, but nonetheless the possibility to manipulate cellular proliferation with specific <em>in vivo</em> – modifications of pectins was introduced. </p><p>When implanted into rat soft tissues, neither of the apple MHRs provoked severe acute inflammatory reactions, which indicates good <em>in vivo</em> - tolerance of these botanical macromolecules. These studies illustrate the biocompatibility of MHRs, and the directions towards which they could be further tailored. In terms of clinical use, their tolerability <em>in vivo</em> is especially significant. </p></div>