Preparation and in vitro characterization of monoclonal antibody ranibizumab conjugated magnetic nanoparticles for ocular drug delivery

Gold coated magnetite nanoparticles were prepared and coated with ranibizumab as an ocular drug delivery system. The surface morphologies of the nanoparticles were determined by Scanning Electron Microscopy (SEM). The size and surface charge were determined by using the dynamic light scattering (DLS) technique. Crystallographic properties of the gold coated Fe3O4 nanoparticles were recorded on X-ray diffractometer (XRD) the XRD pattern of nanoparticlees were shown to have uniqe Fe3O4 and gold peaks. Conjugation of ranibizumab onto nanoparticles was achieved using the physical adsorption method. The amount of ranibizumab on the surface of the nanoparticles was determined by thermogravimetric analysis (TGA). In the in vitro release studies performed using UV spectroscopy; it was found that almost 60% of antibodies were released within the first 30 minutes. Antibody activity after release studies was also proved with ELISA. Non-toxicity of gold coated Fe3O4 particles were proved with MTT. Results of the studies, showed that the antibody conjugated magnetic nanoparticle system could be a potential treatment system for ocular diseases.

Oxacillin magnetically targeted for the treatment of Methicillin-Resistant S. aureus infection in rats

Abstract Purpose: To evaluate the effect of oxacillin bonded to magnetic nanoparticles in local infection model in rat. Methods: Twelve Wistar rats weighing 290±18g were randomly divided into four groups (n=6, each) and all rats had a magnet ring sutured on their right thighs. In the biodistribution group rats 0.1mL of 99mTc-magnetite (0.66 MBq) was injected i.v and after 30 minutes, biodistribution of 99mTc-magnetite was evaluated in right and left thighs. The other groups were inoculated with MRSA in each thigh muscles. Group 1 rats were injected i.v. with magnetite, group 2 with Magnetite + Oxacillin, group 3 with saline twice a day. After 24 hours samples of muscle secretion were harvested for microbiological analysis; muscle, lungs and kidneys for histology. Results: 99mTc-magnetite uptake was three-fold higher in right thigh muscles (with external magnet) than in the left. In magnetite and oxacillin-magnetite groups, bacterial/CFU was significantly lower in thigh muscles than in saline-controls. The inflammatory reaction in muscles and lungs was significantly lower in oxacillin-magnetite group-rats than in other groups (p<0.001) . Conclusion: This study confirms the potential antimicrobial activity of magnetic nanoparticles for Methicillin-Resistant S. aureus strains, which in addition to concentrate the antibiotic at the infection site, positively influenced the treatment.

Trastuzumab-Conjugated Liposome-Coated Fluorescent Magnetic Nanoparticles to Target Breast Cancer

OBJECTIVE: To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNP@m-SiO2]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNP@m-SiO2]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. MATERIALS AND METHODS: The physiochemical characteristics of Lipo[MNP@m-SiO2] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNP@m-SiO2] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin(R))-conjugated Lipo[MNP@m-SiO2] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. RESULTS: We obtained uniformly-sized and evenly distributed Lipo[MNP@m-SiO2] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNP@m-SiO2] was observed by in vitro fluorescence and MR imaging. CONCLUSION: Trastuzumab-conjugated Lipo[MNP@m-SiO2] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.