In vitro and in vivo drug release and antibacterial properties of the novel vancomycin-loaded bone-like hydroxyapatite/poly amino acid scaffold.
Antibiotic-loaded carriers were developed to fill cavities and locally deliver antibiotics following implantation. However, the most commonly used antibiotic carrier, polymethyl methacrylate (PMMA), has many disadvantages including that it does not promote bone regeneration or conduction. Vancomycin-loaded bone-like hydroxyapatite/poly amino acid (V-BHA/PAA) was successfully fabricated by a homogeneous method, certified as biosafe and known to promote osteogenesis. To evaluate its drug-release features, the quantity of the vancomycin in the elution was obtained every 2 days after in vitro simulated body fluid immersion. The drug concentration in the elution was determined to obtain the drug-release curve. The in vitro drug release was a three-phase process with two release peaks. Its antibacterial activity was evaluated in vitro using an antibacterial zone assay, antibacterial inhibition, and scanning electron microscopy (SEM) observation. Scaffolds of V-BHA/PAA were implanted into a rabbit model of chronic osteomyelitis. The antibacterial activity of the material was evaluated in vivo by gross observations, X-ray, and histological and ultrastructural observations. During the first 48 h, the vancomycin release was more rapid, followed by a period of sustained slow release. Use of V-BHA/PAA could achieve relatively long-term vancomycin delivery of 38 days in vitro and 42 days in vivo. V-BHA/PAA showed a significant and consistent bactericidal effect toward bothStaphylococcus aureusand methicillin-resistantS. aureus(MRSA) in vitro and in vivo. Moreover, the bactericidal effect was stronger than that of vancomycin-loaded polymethyl meth acrylate (V-PMMA). The duration of the antibacterial effect of V-BHA/PAA toward bothS. aureusand MRSA exceeded 28 days in vitro, while that of V-PMMA lasted only 14 days. The curative rate for V-BHA/PAA in the chronic osteomyelitis model was 75% for regularS. aureusand 66.67% for MRSA infection, which significantly exceeded that of V-PMMA (50% and 41.67%, respectively). Vancomycin released from the V-BHA/PAA scaffold was significantly superior to that delivered by V-PMMA.
Department of Orthopedics, The Emergency Medical Center of Chongqing City, Chongqing, People's Republic of China.
Zhidong
Z
Cao
Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
Dianming
D
Jiang
Department of Orthopedics, The First People's Hospital of Zunyi City, Zunyi, People's Republic of China.
Ling
L
Yan
Department of Orthopedics, Children's Hospital Affiliated to Chongqing University of Medical Sciences, Chongqing, People's Republic of China.
Jun
J
Wu
D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D001842:Bone and Bones / Q000737:chemistry* / Q000187:drug effects / Q000473:pathology; D015169:Colony Count, Microbial; D065546:Drug Liberation; D017886:Durapatite / Q000494:pharmacology*; D007958:Leukocyte Count; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D011817:Rabbits; D013203:Staphylococcal Infections / Q000097:blood / Q000188:drug therapy / Q000473:pathology; D054457:Tissue Scaffolds / Q000737:chemistry*; D014640:Vancomycin / Q000494:pharmacology*
D000596:Amino Acids; D000900:Anti-Bacterial Agents; D014640:Vancomycin; D017886:Durapatite
BHA/PAA; chronic osteomyelitis; drug release; local antibiotics delivery; scaffold; vancomycin