title: Porous implants as drug delivery vehicles to augment host tissue integration.
abstract: The common premise of synthetic implants in the restoration of diseased tissues and organs is to use inert and solid materials. Here, a porous titanium implant was fabricated for the delivery of microencapsulated bioactive cues. Control-released transforming growth factor-beta1 (TGF-beta1) promoted the proliferation and migration of human mesenchymal stem cells into porous implants in vitro. At 4 wk of implantation in the rabbit humerus, control-released TGF-beta1 from porous implants significantly increased bone-to-implant contact (BIC) by 96% and bone ingrowth by 50% over placebos. Control-released 100 ng TGF-beta1 induced equivalent BIC and bone ingrowth to adsorbed 1 microg TGF-beta1, suggesting that controlled release is effective at 10-fold less drug dose than adsorption. Histomorphometry, scanning electron microscopy, and microcomputed tomography showed that control-released TGF-beta1 enhanced bone ingrowth in the implant's pores and surface. These findings suggest that solid prostheses can be transformed into porous implants to serve as drug delivery carriers, from which control-released bioactive cues augment host tissue integration.
authors.affiliation: Department of Neurological Surgery, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Clark
authors.forename: Eduardo K
authors.initials: EK
authors.lastname: Moioli
authors.forename: D Rick
authors.initials: DR
authors.lastname: Sumner
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Mao
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D006811:Humerus; D059630:Mesenchymal Stem Cells / Q000166:cytology; D016348:Osseointegration / Q000187:drug effects*; D016062:Porosity; D019736:Prostheses and Implants; D011817:Rabbits; D014025:Titanium; D053773:Transforming Growth Factor beta1 / Q000008:administration & dosage
chemical_list: D053773:Transforming Growth Factor beta1; D014025:Titanium