title: A novel one-pot process for near-net-shape fabrication of open-porous resorbable hydroxyapatite/protein composites and in vivo assessment.
abstract: We present a mild one-pot freeze gelation process for fabricating near-net, complex-shaped hydroxyapatite scaffolds and to directly incorporate active proteins during scaffold processing. In particular, the direct protein incorporation enables a simultaneous adjustment and control of scaffold microstructure, porosity, resorbability and enhancement of initial mechanical and handling stability. Two proteins, serum albumin and lysozyme, are selected and their effect on scaffold stability and microstructure investigated by biaxial strength tests, electron microscopy, and mercury intrusion porosimetry. The resulting hydroxyapatite/protein composites feature adjustable porosities from 50% to 70% and a mechanical strength ranging from 2 to 6 MPa comparable to that of human spongiosa without any sintering step. Scaffold degradation behaviour and protein release are assessed by in vitro studies. A preliminary in vivo assessment of scaffold biocompatibility and resorption behaviour in adult domestic pigs is discussed. After implantation, composites were resorbed up to 50% after only 4 weeks and up to 65% after 8 weeks. In addition, 14% new bone formation after 4 weeks and 37% after 8 weeks were detected. All these investigations demonstrate the outstanding suitability of the one-pot-process to create, in a customisable and reliable way, biocompatible scaffolds with sufficient mechanical strength for handling and surgical insertion, and for potential use as biodegradable bone substitutes and versatile platform for local drug delivery.
authors: University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen, Germany. Electronic address: beritm@uni-bremen.de.
authors: Berit
authors: B
authors: Mueller
authors: German Aerospace Center, Ceramic Composite Structures, Pfaffenwaldring 38-40, 70569 Stuttgart, Germany. Electronic address: dietmar.koch@dlr.de.
authors: Dietmar
authors: D
authors: Koch
authors: University of Erlangen-Nuremberg, Department of Oral and Maxillofacial Surgery, Glueckstrasse 11, 91054 Erlangen, Germany. Electronic address: rainer.lutz@uk-erlangen.de.
authors: Rainer
authors: R
authors: Lutz
authors: University of Erlangen-Nuremberg, Department of Oral and Maxillofacial Surgery, Glueckstrasse 11, 91054 Erlangen, Germany. Electronic address: andreas.schlegel@uk-erlangen.de.
authors: Karl A
authors: KA
authors: Schlegel
authors: University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen, Germany. Electronic address: treccani@uni-bremen.de.
authors: Laura
authors: L
authors: Treccani
authors: University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen, Germany. Electronic address: krezwan@uni-bremen.de.
authors: Kurosch
authors: K
authors: Rezwan
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D001861:Bone Regeneration / Q000187:drug effects; D018786:Bone Substitutes / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D002417:Cattle; D002645:Chickens; D017886:Durapatite / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D005260:Female; D008422:Materials Testing; D009113:Muramidase; D053761:Nanocomposites / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D012710:Serum Albumin, Bovine; D013552:Swine
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D011506:Proteins; D012710:Serum Albumin, Bovine; D017886:Durapatite; C421864:hen egg lysozyme; D009113:Muramidase
keywords: Biomimetic material; Bioresorption; Bone graft; Hydroxyapatite composite; Porosity; Protein