BEH.462/3. 962J Molecular Principles of Biomaterials Spring 2003 Lecture 11: Molecular Design and Synthesis of Biomaterials Il: Inorganic Biomaterials Last time: hydrogel applications: molecular imprinting and responsive drug delivery Today biomineralization and biomimetic inorganic/organic composites Inorganic biomaterials Reading L A. Estroff and A D. Hamilton, ' At the interface of organic and inorganic chemistry bioinspired synthesis of composite materials, Chem. Mater. 13, 3227-3235 (2001) tephen Mann, 'Biomineralization Principles and Concepts in Bioinorganic Materials Chemistry, Ch 5 pp. 68-88, Oxford Univ Press(2001) 1 million orthopaedic surgeries involving bone grafting materials each year in US(R Langer et al. Tissue Eng, 1 o autografting is best but limited in the size of defects that can be corrected (J. South Orthop ssoc. 9, 91 (2000): Aust J Surg. 69, 7 allografting presents possibility of disease transmission(HIV, hep B)(S Mendenhall; Commetnary: the bone graft market in the United States, in Bone engineering J.e. Davis, ed, em squared incorporated 2000, Torotonto, Canada p 585-590) o synthetic solid hydroxyapatite resorbs very slowly(Clin Orthop. 157, 259(1981)) Bone Tissue Engineering JBRM 29, 359(1995)Ca phosphate JBMR 36, 17(1997) PLGA Biomaterials 19, 1405(1998)PLGA J Biomat Sci-polym ed, 7, 661(1996)PLGA-Ca phos composite Test Biomineralization and biomimetic inorganic crystals Structure and synthesis mechanisms of biomimetic inorganic crystals motivation for studying biomineralization o natural bone composite organization, with organic molecules (peptides and proteins) guiding inorganic crystal growth, allows shapes that defy the classical 230 space groups of crystalline materials o biomineralization processes vs laboratory methods Biological methods- benign synthesis methods 1. Precisely control upon morphologies and structures over several length scales 2. Occur at near neutral PH, ambient temperature and pressure 3. Customize and optimize properties of materials according to the environme Laboratory methods: 1. Rely on extreme pH conditions form specific morphologies or patterned structures 2. high temperature and/or high pressure synthesis 3. Simple structure o up to 3000X greater strength than pure inorganic crystal Lecture 11-Inorganic Biomaterials 1of12BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Lecture 11 – Inorganic Biomaterials 1 of 12 Lecture 11: Molecular Design and Synthesis of Biomaterials III: Inorganic Biomaterials Last time: hydrogel applications: molecular imprinting and responsive drug delivery Today: biomineralization and biomimectic inorganic/organic composites Inorganic biomaterials Reading: L.A. Estroff and A.D. Hamilton, ‘At the interface of organic and inorganic chemistry: bioinspired synthesis of composite materials,’ Chem. Mater. 13, 3227-3235 (2001) Stephen Mann, ‘Biomineralization: Principles and Concepts in Bioinorganic Materials Chemistry,’ Ch. 5 pp. 68-88, Oxford Univ. Press (2001) • 1 million orthopaedic surgeries involving bone grafting materials each year in US (R. Langer et al. Tissue Eng., 1, 151 (1995)) o autografting is best but limited in the size of defects that can be corrected (J. South Orthop ssoc. 9, 91 (2000); Aust N Z J Surg. 69, 726 (1999)) o allografting presents possibility of disease transmission (HIV, hep B) (S. Mendenhall; Commetnary: the bone graft market in the United States, in Bone engineering J.e. Davis, ed., em squared incorporated 2000, Torotonto, Canada p. 585-590) o synthetic solid hydroxyapatite resorbs very slowly (Clin Orthop. 157, 259 (1981)) Bone Tissue Engineering: JBRM 29, 359 (1995) Ca phosphate JBMR 36, 17 (1997) PLGA Biomaterials 19, 1405 (1998) PLGA J Biomat Sci-polym ed, 7, 661 (1996) PLGA-Ca phos composite Test Biomineralization and biomimetic inorganic crystals1 Structure and synthesis mechanisms of biomimetic inorganic crystals2-4 • motivation for studying biomineralization o natural bone composite organization, with organic molecules (peptides and proteins) guiding inorganic crystal growth, allows shapes that defy the classical 230 space groups of crystalline materials o biomineralization processes vs. laboratory methods • Biological methods - benign synthesis methods 1. Precisely control upon morphologies and structures over several length scales 2. Occur at near neutral PH, ambient temperature and pressure 3. Customize and optimize properties of materials according to the environment • Laboratory methods: 1. Rely on extreme pH conditions form specific morphologies or patterned structures 2. high temperature and/or high pressure synthesis 3. Simple structure o o up to 3000X greater strength than pure inorganic crystal