Nanoscale influences on bioactivity : ultrastructure and nanomechanics of model bioactive hydroxyapatite based biomaterials

There is a significant need for improved synthetic materials as orthopedic implants to replace human bone lost and damaged due to disease or injury. Certain ceramics, such as hydroxyapatite (HA), have the special property of being bioactive, meaning that an interfacial bond between the implant and the surrounding tissue forms, leading to good fixation. Bioactive ceramics are being investigated in a wide variety of forms for use in different bone implant applications. Three model synthetic HA based bioceramic systems were examined; phase pure, dense, polycrystalline HA; phase pure, dense, polycrystalline HA with 0.8 wt% silicon substituted into the lattice (SiHA); and phase pure, dense, nanostructured HA (nanoHA) with grain sizes less than 100 nm. SiHA has shown markedly enhanced bioactivity over non-substituted HA yet they have similar micro- and meso-scale properties and nanoHA has shown increased bioactivity over traditionally structured HA although they are chemically identical. The form of a biomaterial, the nanoscale surface chemical properties (e.g. surface functional groups, charge distribution, Hamaker constant), and morphological structure (e.g. grain size, shape, distribution, roughness) will govern its interaction with the biological environment.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Vandiver, Jennifer M. (Jennifer McKeehan)

Advisor dc:contributor.advisor

• Christine Ortiz.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/37569

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/37569