Enhanced drug targeting by attachment of an anti alphav integrin antibody to doxorubicin loaded human serum albumin nanoparticles.

Specific transport of anti-cancer drugs into tumor cells may result in increased therapeutic efficacy and decreased adverse events. Expression of alphavbeta3 integrin is enhanced in various types of cancer and monoclonal antibodies (mAbs) directed against alphavbeta3 integrins hold promise for anti-cancer therapy. DI17E6 is a monoclonal antibody directed against alphav integrins that inhibits growth of melanomas in vitro and in vivo and inhibits angiogenesis due to interference with alphavbeta3 integrins. Here, DI17E6 was covalently coupled to human serum albumin nanoparticles. Resulting nanoparticles specifically targeted alphavbeta3 integrin positive melanoma cells. Moreover, doxorubicin loaded DI17E6 nanoparticles showed increased cytotoxic activity in alphavbeta3-positive melanoma cells than the free drug. Therefore, DI17E6-coupled human serum albumin nanoparticles represent a potential delivery system for targeted drug transport into alphavbeta3-positive cells.

Specific targeting of HER2 overexpressing breast cancer cells with doxorubicin-loaded trastuzumab-modified human serum albumin nanoparticles.

Specific targeting of tumor cells to achieve higher drug levels in tumor tissue and to overcome cardiotoxic and other secondary effects is the major goal in cancer therapy. With trastuzumab as a humanized monoclonal antibody binding, the HER2 receptor specific targeting is possible. In the present study, target-oriented nanoparticles based on biodegradable human serum albumin (HSA) loaded with cytostatic drug doxorubicin were developed. The surface of the nanoparticles was modified by covalent attachment of trastuzumab. HER2 overexpressing breast cancer cells showed a good cellular binding and uptake of these nanoparticles. The specific transport of the cytostatic drug doxorubicin with this nanoparticulate formulation into the HER2 overexpressing breast cancer cells, their release, and biological activity was demonstrated. The results indicate that these cell-type specific drug-loaded nanoparticles could achieve an improvement in cancer therapy. To our knowledge, this is the first study demonstrating a specific trastuzumab-based targeting of HER2 overexpressing breast cancer cells with doxorubicin-loaded nanoparticles.

Freeze drying of human serum albumin (HSA) nanoparticles with different excipients.

Freeze drying is a suitable technique to improve the long-term storage stability of colloidal drug carrier systems such as nanoparticles. Aim of this study was to systematically evaluate excipients for the freeze drying and long-term stability of albumin-based nanoparticles. In our study, nanoparticles made of human serum albumin (HSA) were freeze dried in the presence of different cryoprotective agents and after reconstitution were evaluated with regard to their physico-chemical characteristics. Empty, doxorubicin-loaded, and PEGylated nanoparticles were prepared and were freeze dried in the presence of different concentrations of sucrose, trehalose, and mannitol, respectively. The samples were physico-chemically characterised with regard to lyophilisate appearance, particle size, and polydispersity using photon correlation spectroscopy. For evaluation of long-term stability, the samples were stored at 2-8, 25, and 40 degrees C over predetermined time intervals. In the absence of cryoprotectants, particle growth was observed in all freeze-dried formulations. In the presence of sucrose, mannitol, and trehalose aggregation of HSA nanoparticles during the freeze-drying procedure was prevented. Although all of the excipients were identified to be suitable stabilisers for freeze drying of HSA nanoparticles, sucrose and trehalose were superior to mannitol, especially with regard to the long-term storage stability results.