What Is the Force-per-Molecule Inside a Biomaterial Having Randomly Oriented Units?

Abstract

Both synthetic and natural protein-based materials are made of randomly oriented cross-linked molecules. Here we introduce a coarse-grained approach to estimate the average force-per-molecule for materials made from globular proteins. Our approach has three steps: placement of molecules inside a unit volume, cross-linking, and trimming to remove the protein domains that do not participate to the force response. Following this procedure, we estimate the number of active domains per cross-section area, that allows for a direct calculation of the force-per-domain. Among the variables considered, we found that concentration was the most sensitive parameter. We then synthesized protein hydrogels made from BSA and polyprotein L and measured the stresses that these materials can withstand. We found that forces-per-molecules of up to 17 pN per domain can be obtained experimentally using protein hydrogels. Our approach represents an important step toward understanding the scaling of tension in biomaterials.Letter pubs.acs.org/JPCL

A Study on How Conformation Entropy of Attached Macromolecules Drives Polymeric Collapse and Protein Folding

“…The value for the bending angle was chosen to match the persistence length of a polypeptide chain. [ 11 ] During simulations, the molecules were not allowed to have coordinates with negative values in z . Following these simulations, the generated trajectories (molecular conformations) were used to estimate the separation between the free end and the surface, as well as the molecular end‐to‐end length, following the same procedure, as described above.…”

Intensified cross-linking dramatically improved the mechanical properties of hydroxyapatite and cellulose composites for repairing bone segmental defects

“…[11][12][13][14][15] The covalent and ionic bonds are strong bonds with energies 4100 kJ mol À1 . Although the energy of H-bonds is often one order of magnitude lower than that of covalent and ionic bonds, 16,17 the number of H-bonds in natural bone is large. A high number of H-bonds is thus an important consideration in the design of the bone-repair material.…”