BEH.462/3. 962J Molecular Principles of Biomaterials Spring 2003 Lecture 12: Organic templating of inorganic materials and bone biomimesis Last time interfacial biomineralization and biomimetic inorganic chemistry Today biological strategies for inorganic templating by organic materials Biomimetic plate material Biomimesis of bone Reading S Mann, 'Biomineralization: Principles and Concepts of Bioinorganic Materials Chemistry, Ch 6, pp. 89-124(2001) Biological strategies for inorganic templating by organic materials Alteration of barriers to nucleation Organic surfaces alter free energy barrier to nucleation(Mann Science 1993) △Gn AG 级=级 Fig. 2. Diagrammatic rep- AG and presence(state 2)of ganic surface (b)depending on the levels of recogn fidelity of matrix production, both of which may be influenced by genetic. metabolic, and environmental processes o Reminder of free energy of nucleation(homogeneous, but principle applies to heterogeneous surface nucleation as well) △Gm=△Gme-△Ghak=4m-m Where AGv is the free energy change for formation of the solid per mole from the ions, and Vm is the molar volume of the nucleated solid Lecture 12-Inorganic biomaterials 1of13BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Lecture 12: Organic templating of inorganic materials and bone biomimesis Last time: interfacial biomineralization and biomimetic inorganic chemistry Today: biological strategies for inorganic templating by organic materials Biomimetic organic template materials Biomimesis of bone Reading: S. Mann, ‘Biomineralization: Principles and Concepts of Bioinorganic Materials Chemistry,’ Ch. 6, pp. 89-124 (2001) Biological strategies for inorganic templating by organic materials Alteration of barriers to nucleation • Organic surfaces alter free energy barrier to nucleation (Mann Science 1993) ∆G* ∆Gnuc o Reminder of free energy of nucleation (homogeneous, but principle applies to heterogeneous surface nucleation as well): ∆Gnuc = ∆Gsurface − ∆Gbulk = 4πr 2 σ − 4 3 πr 3 ∆Gv Vm ƒ Where ∆Gv is the free energy change for formation of the solid per mole from the ions, and Vm is the molar volume of the nucleated solid Lecture 12 – Inorganic Biomaterials 1 of 13