title: Preparation and biological characteristics of recombinant human bone morphogenetic protein-2-loaded dextran-co-gelatin hydrogel microspheres, in vitro and in vivo studies.
abstract: Hydrogels are based on hydrophilic polymers which are cross-linked to prevent dissolution in water. Because hydrogels can contain large amounts of water, they are interesting devices for the delivery of protein drugs. In this contribution, biodegradable dextran-co-gelatin hydrogel microspheres (DG-MPs) are described which are based on physical interactions and are particularly suitable for the controlled delivery of pharmaceutically active proteins. The unique feature of this preparation system is that the hydrogel microsphere formation takes place in an all-aqueous solution, by which the use of organic solvents is avoided. We investigated the preparation and biological activities of recombinant human bone morphogenetic protein-2 (rhBMP2)-loaded dextran-co-gelatin hydrogel microspheres (rhBMP2-DG-MPs), which aimed to keep rhBMP2's biological activity and to achieve a long-term sustained release of rhBMP2. The microspheres' average diameter was about 20-40 microm and rhBMP2 release in vitro could be maintained for >10 days. Cytology studies showed that using rhBMP2-DG-MPs could promote the proliferation and osteoblastic differentiation of periodontal ligament cells better than using rhBMP2 aqueous solution. By a freeze-drying method, rhBMP2-DG-MPs could be adhered in chitosan membranes for guided tissue regeneration use, namely functionalized membranes. To evaluate bone regeneration induced by rhBMP2-DG-MPs, an animal experiment with canine class III furcation defects was adopted and the results indicated that using rhBMP2-DG-MPs incorporating scaffolds and functionalized membranes could gain more periodontal tissue regeneration than using scaffolds and general membranes soaked with concentrated rhBMP2 aqueous solution. Therefore, those studies demonstrate the potential of DG-MPs in the sustained delivery of low dosages of rhBMP2 to periodontal defects.
authors.affiliation: Center Laboratory for Tissue Engineering, College of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: Faming
authors.initials: F
authors.lastname: Chen
authors.forename: Zhifen
authors.initials: Z
authors.lastname: Wu
authors.forename: Qintao
authors.initials: Q
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Nie
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage* / Q000627:therapeutic use; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D048271:Chitosan; D003692:Delayed-Action Preparations; D003911:Dextrans; D004285:Dogs; D005260:Female; D017823:Furcation Defects / Q000628:therapy; D005780:Gelatin; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D020100:Hydrogels; D008863:Microspheres; D010513:Periodontal Ligament / Q000166:cytology; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D013678:Technology, Pharmaceutical; D016212:Transforming Growth Factor beta / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D003692:Delayed-Action Preparations; D003911:Dextrans; D020100:Hydrogels; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D005780:Gelatin; D048271:Chitosan