title: Highly porous bioresorbable scaffolds with controlled release of bioactive agents for tissue-regeneration applications.
abstract: Highly porous poly(DL-lactic-co-glycolic acid) films with controlled release of horseradish peroxidase (HRP) as a model protein have been successfully developed and studied. These films, which are prepared by freeze-drying inverted emulsions, are designed for use in tissue-regeneration applications. The effects of the emulsion's formulation and host polymer's characteristics on the film's microstructure and HRP release profile over 4 weeks were investigated. A dual pore size population is characteristic for most films, with large 12-18 microm pores and small 1.5-7 microm pores, and porosity in the range of 76-92%. An increase in the polymer content and its initial molecular weight, organic/aqueous (O:A) phase ratio and lactic acid content, or a decrease in the HRP content, all resulted in a decreased burst effect and a more moderate release profile. A simultaneous change in two or three of these formulation parameters (compared to a reference formulation) resulted in a synergistic effect on the HRP release profile. A constant HRP release rate was achieved when a composite film was used. Human gingival fibroblast adhesion to the films indicated good biocompatibility. Appropriate selection of the emulsion's parameters can therefore yield highly porous films with the desired protein-release behavior which can serve as scaffolds for bioactive agents in tissue-regeneration applications.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, Tel-Aviv University, Tel-Aviv 69978, Israel.
authors.forename: Orly
authors.initials: O
authors.lastname: Grinberg
authors.forename: Itzhak
authors.initials: I
authors.lastname: Binderman
authors.forename: Hila
authors.initials: H
authors.lastname: Bahar
authors.forename: Meital
authors.initials: M
authors.lastname: Zilberman
mesh_terms: D001672:Biocompatible Materials / Q000494:pharmacology*; D002478:Cells, Cultured; D003692:Delayed-Action Preparations; D004655:Emulsions; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D048091:Guided Tissue Regeneration / Q000379:methods*; D006735:Horseradish Peroxidase / Q000494:pharmacology*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000494:pharmacology; D016062:Porosity / Q000187:drug effects; D012038:Regeneration / Q000187:drug effects*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D004655:Emulsions; D011108:Polymers; D006735:Horseradish Peroxidase