title: A novel controlled-release system for antibacterial enzyme lysostaphin delivery using hydroxyapatite/chitosan composite bone cement.
abstract: In this work, a lysostaphin-loaded, control-released, self-setting and injectable porous bone cement with efficient protein delivery was prepared by a novel setting method using hydroxyapatite/chitosan (HA/CS) composite scaffold. The cement samples were made through cementitious reactions by mixing solid powder, a mixture of HA/CS composite particles, lysostaphin, Ca(OH)2, CaCO3 and NaHCO3, with setting liquid containing citric acid, acetic acid, NaH2PO4, CaCl2 and poloxamer. The setting parameters of the cement samples were determined. The results showed that the final setting time was 96.6±5.2 min and the pH value increased from approximately 6.2 to nearly 10 during the setting process and the porosity was 34% at the end. And the microstructure and composition were detected by scanning electron microscopy (SEM), x-ray diffraction and Fourier transform-infrared spectroscopy. For the release behavior of lysostaphin loaded in the cement sample, the in vitro cement extract experiment indicated that about 94.2±10.9% of the loaded protein was released before day 8 and the in vivo Qdot 625 fluorescence tracking experiment showed that the loaded protein released slower than the free one. Then the biocompatibility of the cement samples was evaluated using the methylthiazol tetrazolium assay, SEM and hematoxylin-eosin staining, which suggested good biocompatibility of cement samples with MC 3T3-E1 cells and subcutaneous tissues of mice. Finally the antibacterial activity assay indicated that the loaded lysostaphin had good release ability and strong antibacterial enzymatic activity against methicillin-resistant Staphylococcus aureus. Collectively, all the results suggested that the lysostaphin-loaded self-setting injectable porous bone cement released the protein in a controlled and effective way and the protein activity was well retained during the setting and releasing process. Thus this bone cement can be potentially applied as a combination of artificial bone substitute and controlled-release system for delivery of lysostaphin to treat bone defects and infections.
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, PR China.
authors.forename: Bai
authors.initials: B
authors.lastname: Xue
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, PR China; Shanghai High-Tech United Bio-Technological R&D Co., Ltd, 501 Jingang Road, Shanghai, 201206, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Shanghai High-Tech United Bio-Technological R&D Co., Ltd, 501 Jingang Road, Shanghai, 201206, PR China.
authors.forename: Yihan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, PR China.
authors.forename: Jincheng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Shanghai High-Tech United Bio-Technological R&D Co., Ltd, 501 Jingang Road, Shanghai, 201206, PR China.
authors.forename: Jien
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Shanghai High-Tech United Bio-Technological R&D Co., Ltd, 501 Jingang Road, Shanghai, 201206, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Lu
authors.affiliation: Shanghai High-Tech United Bio-Technological R&D Co., Ltd, 501 Jingang Road, Shanghai, 201206, PR China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Stomatology, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Shanghai, 200433, PR China.
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 220 Handan Road, Shanghai, 200433, PR China; Shanghai High-Tech United Bio-Technological R&D Co., Ltd, 501 Jingang Road, Shanghai, 201206, PR China.
authors.forename: Qingshan
authors.initials: Q
authors.lastname: Huang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001672:Biocompatible Materials / Q000737:chemistry; D001843:Bone Cements / Q000737:chemistry*; D002460:Cell Line; D048430:Cell Shape / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations; D017886:Durapatite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008248:Lysostaphin / Q000494:pharmacology*; D008422:Materials Testing; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008813:Mice, Inbred ICR; D008826:Microbial Sensitivity Tests; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D001843:Bone Cements; D003692:Delayed-Action Preparations; D048271:Chitosan; D017886:Durapatite; D008248:Lysostaphin