title: Enhancement of antibacterial activity of tilmicosin against Staphylococcus aureus by solid lipid nanoparticles in vitro and in vivo.
abstract: This study aimed to enhance the antibacterial activity of tilmicosin by solid lipid nanoparticles (SLN). Tilmicosin-loaded hydrogenated castor oil (HCO)-SLN was prepared using a hot homogenisation and ultrasonication method. The physicochemical characteristics of SLN were investigated by scanning electron microscopy (SEM) and photon correlation spectroscopy (PCS). The antibacterial activity of tilmicosin-SLN against Staphylococcus aureus was evaluated by growth inhibition and colony-counting method. A therapeutic study of tilmicosin-SLN was conducted by subcutaneous injection in a mouse mastitis model infected with S. aureus by teat canal infusion. Therapeutic efficacy was assessed by physical appearance of the mammary gland and measurement of colony-forming units (CFU) per gland. The results showed that the diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 343±26 nm, 0.33±0.08, -7.9±0.4 mV, 60.4±3.3% and 11.2±0.47%, respectively. Tilmicosin-SLN showed a sustained-release effect and sustained and enhanced antibacterial activity in vitro. SLN significantly enhanced the therapeutic efficacy of tilmicosin determined by lower CFU counts and a decreased degree of inflammation. These results demonstrated that the HCO-SLN is an effective carrier to enhance the antibacterial activity of tilmicosin.
authors: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, 2 Yuanmingyuan Road West, Beijing 100193, PR China.
authors: X F
authors: XF
authors: Wang
authors: S L
authors: SL
authors: Zhang
authors: L Y
authors: LY
authors: Zhu
authors: S Y
authors: SY
authors: Xie
authors: Z
authors: Z
authors: Dong
authors: Y
authors: Y
authors: Wang
authors: W Z
authors: WZ
authors: Zhou
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D002368:Castor Oil / Q000008:administration & dosage; D002417:Cattle; D002626:Chemistry, Pharmaceutical; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D008055:Lipids / Q000008:administration & dosage; D008414:Mastitis, Bovine / Q000188:drug therapy*; D051379:Mice; D008815:Mice, Inbred Strains; D053758:Nanoparticles; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000187:drug effects*; D013234:Stem Cells / Q000187:drug effects; D015645:Tylosin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D008055:Lipids; D002368:Castor Oil; C052319:tilmicosin; D015645:Tylosin