title: Treatment of Staphylococcus aureus-induced chronic osteomyelitis with bone-like hydroxyapatite/poly amino acid loaded with rifapentine microspheres.
abstract: OBJECTIVE
  The purpose of this study was to investigate the curative effect of bone-like hydroxyapatite/poly amino acid (BHA/PAA) as a carrier for poly(lactic-co-glycolic acid)-coated rifapentine microsphere (RPM) in the treatment of rabbit chronic osteomyelitis induced by Staphylococcus aureus.
  
  
  METHODS
  RPM was prepared through an oil-in-water emulsion solvent evaporation method, and RPM was combined with BHA/PAA to obtain drug-loaded, slow-releasing materials. Twenty-six New Zealand white rabbits were induced to establish the animal model of chronic osteomyelitis. After debridement, the animals were randomly divided into three groups (n=8): the experimental group (with RPM-loaded BHA/PAA), the control group (with BHA/PAA), and the blank group. The RPM-loaded BHA/PAA was evaluated for antibacterial activity, dynamics of drug release, and osteogenic ability through in vitro and in vivo experiments.
  
  
  RESULTS
  In vitro, RPM-loaded BHA/PAA released the antibiotics slowly, inhibiting the bacterial growth of S. aureus for up to 5 weeks. In vivo, at week 4, the bacterial colony count was significantly lower in the experimental group than in the control and blank groups (P<0.01). At week 12, the chronic osteomyelitis was cured and the bone defect was repaired in the experimental group, whereas the infection and bone defect persisted in the control and blank groups.
  
  
  CONCLUSIONS
  In vitro and in vivo experiments demonstrated that RPM-loaded BHA/PAA effectively cured S. aureus-induced chronic osteomyelitis. Therefore, BHA/PAA has potential value as a slow-releasing material in clinical setting. Further investigation is needed to determine the optimal dosage for loading rifapentine.
authors.affiliation: Department of Pathology, College of Basic Medicine, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Yan
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Dian-Ming
authors.initials: DM
authors.lastname: Jiang
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Zhi-Dong
authors.initials: ZD
authors.lastname: Cao
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: Pediatric Hospital, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Cardiology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Zheng-Long
authors.initials: ZL
authors.lastname: Wang
authors.affiliation: Department of Radiology, College of Basic Medicine, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Ya-Jun
authors.initials: YJ
authors.lastname: Li
authors.affiliation: Department of Pathology, College of Basic Medicine, Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Yong-Fen
authors.initials: YF
authors.lastname: Yi
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D002908:Chronic Disease; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry; D019344:Lactic Acid / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D008863:Microspheres; D010019:Osteomyelitis / Q000188:drug therapy* / Q000382:microbiology; D011100:Polyglycolic Acid / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D012293:Rifampin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017886:Durapatite; D012293:Rifampin; C018421:rifapentine
keywords: antibiotics-loaded bone materials; antimicrobial; bone defect; osteoconduction; osteomyelitis