title: Steady antibiotic release from biodegradable beads in the pleural cavity: an in vitro and in vivo study.
abstract: BACKGROUND
  Inadequate localized drug concentrations and systemic adverse effects are among the concerns when regional infections are treated with systemic antibiotics. We designed and fabricated a poly(D,L)-lactide-co-glycolide (PLGA)-based biodegradable drug delivery system and evaluated the release of antibiotics both in vitro and in vivo.
  
  
  METHODS
  PLGA copolymer and penicillin G sodium were mixed, compressed, and sintered to fabricate biodegradable antibiotic beads. The beads were placed in phosphate-buffered saline to test the characteristics of in vitro drug release. The beads then were introduced into the pleural cavities through chest tubes of six New Zealand white rabbits. Daily pleural effusion was collected to measure the antibiotic concentration and bacterial inhibitory characteristics.
  
  
  RESULTS
  Forty percent of the penicillin was released in the first day in the in vitro study. The rest of the antibiotic was then gradually released in the following 30 days. All six animals survived the experiment. The initial surge of drug release was less significant in the pleural cavity than in the phosphate-buffered saline. The drug concentrations were well above the minimum inhibitory concentration breakpoint for penicillin susceptibility throughout the study period in both in vitro (30 days) and in vivo (14 days) studies.
  
  
  CONCLUSIONS
  These preliminary findings demonstrated that the biodegradable PLGA antibiotic beads could achieve a fairly steady antibiotic release in the pleural cavity for at least 2 weeks. This drug delivery system may have the potential to serve as an adjuvant treatment of pleural cavity infection.
authors.affiliation: Department of Mechanical Engineering, Chang Gung University, Tao-Yuan; Department of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital, Linkou.
authors.forename: Kuo-Sheng
authors.initials: KS
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, Chang Gung University, Tao-Yuan. Electronic address: shihjung@mail.cgu.edu.tw.
authors.forename: Shih-Jung
authors.initials: SJ
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, Chang Gung University, Tao-Yuan.
authors.forename: Hsiao-Yun
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital, Linkou.
authors.forename: Yao-Kuang
authors.initials: YK
authors.lastname: Huang
authors.affiliation: Department of Ophthalmology, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan.
authors.forename: Yi-Jie
authors.initials: YJ
authors.lastname: Peng
authors.affiliation: Department of Pathology, Chang Gung Memorial Hospital, Linkou.
authors.forename: Ren-Chin
authors.initials: RC
authors.lastname: Wu
authors.affiliation: Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Linkou.
authors.forename: Steve Wen-Neng
authors.initials: SW
authors.lastname: Ueng
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D001682:Biological Availability; D015505:Chest Tubes; D002851:Chromatography, High Pressure Liquid; D052978:Disk Diffusion Antimicrobial Tests; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D015918:Infusion Pumps, Implantable; D019344:Lactic Acid; D008863:Microspheres; D016979:Pasteurella multocida / Q000187:drug effects*; D010400:Penicillin G / Q000493:pharmacokinetics*; D035422:Pleural Cavity / Q000187:drug effects* / Q000378:metabolism* / Q000382:microbiology; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits
chemical_list: D000900:Anti-Bacterial Agents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D010400:Penicillin G