RESUMO
PURPOSE: To formulate conventional contact lenses that incorporate nanosphere-encapsulated antibiotic and demonstrate that the lenses provide for sustained antibacterial activity. METHODS: A copolymer composed of pullulan and polycaprolactone (PCL) was used to synthesize core-shell nanospheres that encapsulated ciprofloxacin. Bactericidal activity of the nanosphere-encapsulated ciprofloxacin (nanosphere/cipro) was tested by using liquid cultures of either Staphylococcus aureus or Pseudomonas aeruginosa. Nanosphere/cipro was then incorporated into HEMA-based contact lenses that were tested for growth inhibition of S. aureus or P. aeruginosa in liquid cultures inoculated daily with fresh bacteria. Lens designs included thin or thick lenses incorporating nanosphere/cipro and ciprofloxacin-HCl-soaked Acuvue lenses (Acuvue; Johnson & Johnson Vision Care, Inc., Jacksonville, FL). RESULTS: Less than 2 µg/mL of nanosphere/cipro effectively inhibited the proliferation of cultures inoculated with 10(7) or 10(8) bacteria/mL of S. aureus and P. aeruginosa, respectively. HEMA-based contact lenses polymerized with nanosphere/cipro were transparent, effectively inhibited the proliferation of greater than 10(7)/mL of bacteria added daily over 3 days of culture, and killed up to 5 × 10(9) total microbes in a single inoculation. A thicker lens design provided additional inhibition of bacterial growth for up to 96 hours. CONCLUSIONS: Core-shell nanospheres loaded with an antibiotic can be incorporated into a conventional, transparent contact lens and provide for sustained and effective bactericidal activity and thereby provide a new drug delivery platform for widespread use in treating ocular disorders.
Assuntos
Anti-Infecciosos/administração & dosagem , Ciprofloxacina/administração & dosagem , Lentes de Contato Hidrofílicas , Sistemas de Liberação de Medicamentos , Nanosferas , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Contagem de Colônia Microbiana , Preparações de Ação Retardada , Glucanos/química , Humanos , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Poliésteres/química , Pseudomonas aeruginosa/fisiologia , Staphylococcus aureus/fisiologiaRESUMO
Completion rates, total cost, and adverse effects were compared for patients in central Massachusetts treated for latent tuberculosis infection with 9 months of isoniazid or 4 months of rifampin. Although the adverse effects were similar between the 2 groups, 4 months of rifampin was associated with significantly better completion rates and less hepatotoxicity yet higher total cost.
