Depth profiling of PLGA copolymer in a novel biomedical bilayer using confocal Raman spectroscopy

Review on Surface Treatment for Implant Infection via Gentamicin and Antibiotic Releasing Coatings

Surface treatment of metallic implants plays a crucial role in orthopedics and orthodontics. Metallic implants produce side-effects such as physical, chemical/electro-chemical irritations, oligodynamic/catalytic and carcinogenic effects. These effects cause bacterial infections and account for huge medical expenses. Treatment for these infections comprises repeated radical debridement, replacement of the implant device and intravenous or oral injection antibiotics. Infection is due to the presence of bacteria in the patient or the surrounding environment. The antibiotic-based medication prevents prophylaxis against bacterial colonization, which is an emphatic method that may otherwise be catastrophic to a patient. Therefore, preventive measures are essential. A coating process was developed with its drug infusion and effect opposing biofilms. Modification in the medical implant surface reduces the adhesion of bacterial and biofilms, the reason behind bacterial attachment. Other polymer-based and nanoparticle-based carriers are used to resolve implant infections. Therefore, using an implant coating is a better approach to prevent infection due to biofilm.

Synergistic antibacterial effect of Bi2S3 nanospheres combined with ineffective antibiotic gentamicin against methicillin-resistant Staphylococcus aureus

In this paper, Bi₂S₃ nanospheres with size of 212nm were prepared by a simple hydrothermal process. The selectively enhanced antibacterial effects of Bi₂S₃ nanospheres with three classes of ineffective antibiotics, β-lactam (cefuroxime, CXM; cefotaxime, CTX and piperacillin, PIP), quinolone (ciprofloxacin, CIP) and aminoglycoside (gentamicin, GEN) against clinical isolated methicillin-resistant Staphylococcus aureus (MRSA) were investigated for the first time. GEN shows significantly synergistic growth inhibition against MRSA when combined with Bi₂S₃ nanospheres, while CXM, CTX, PIP and CIP do not. Raman spectroscopy and Z potential studies reveal that Bi₂S₃ could interact with GEN and the combination showed small electronegativity, which probably induced the increase of GEN content in cytoplasm of bacteria. Furthermore, the combination of Bi₂S₃ nanospheres and GEN can destroy the bacterial membrane function and induce more bactericidal reactive oxygen generation than that of Bi₂S₃ or GEN alone. The cytotoxicity test indicates that the combination of Bi₂S₃ and GEN presented low toxicity to human normal hepatocyte L02. This work shows that Bi₂S₃ nanospheres can be used to enhance the action of ineffective antibiotic GEN against MRSA, thus strengthening the antibiotic capacity for fighting MRSA infections.

Raman imaging of drug delivery systems

This review article includes an introduction to the principals of Raman spectroscopy, an outline of the experimental systems used for Raman imaging and the associated important considerations and limitations of this method. Common spectral analysis methods are briefly described and examples of interesting published studies which utilised Raman imaging of pharmaceutical and biomedical devices are discussed, along with summary tables of the literature at this point in time.