title: Water-borne, in situ crosslinked biomaterials from phase-segregated precursors.
abstract: A novel process for the preparation of water-borne biomaterials for hard tissue repair from injectable precursors is described, where the precursors form crosslinked materials in situ under physiological conditions. The precursors react by means of a Michael-type addition reaction that makes use of addition donors such as pentaerythritol tetrakis 3'-mercaptopropionate (QT) and addition acceptors such as poly(ethylene glycol) diacrylate 570 MW (PEGDA), pentaerythritol triacrylate (TA), and poly(propylene glycol) diacrylate 900 MW (PPODA). These crosslinked materials (at 75 wt% solid), prepared from water dispersions or reverse emulsions, showed ultimate strengths in compression of 1.8 +/- 0.2 and 6.7 +/- 0.5 MPa and ultimate deformations of 35 +/- 2+/- and 37 +/- 2%, respectively. Scanning electron microscopy (SEM) shows that the morphology of the precursors templated the morphology of the final materials. The current study indicates that it is possible to obtain injectable high-modulus materials that have appropriate mechanical properties and gelation kinetics for tissue augmentation and stabilization applications such as mechanical stabilization of the intervertebral disc annulus.
authors.affiliation: Department of Materials, Institute of Biomedical Engineering, Swiss Federal Institute of Technology (ETH), Moussonstrasse 18, CH-8044 Zurich, Switzerland.
authors.forename: Brent
authors.initials: B
authors.lastname: Vernon
authors.forename: Nicola
authors.initials: N
authors.lastname: Tirelli
authors.forename: Thomas
authors.initials: T
authors.lastname: Bächi
authors.forename: David
authors.initials: D
authors.lastname: Haldimann
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Hubbell
mesh_terms: D000179:Acrylates / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D019245:Compressive Strength; D005782:Gels; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011409:Propylene Glycols / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D014867:Water / Q000737:chemistry*
chemical_list: D000179:Acrylates; D001672:Biocompatible Materials; D005782:Gels; D011108:Polymers; D011409:Propylene Glycols; D014867:Water; C012504:polypropylene glycol; D011092:Polyethylene Glycols; C027992:pentaerythrityl triacrylate