Aim: To develop a safe and efficient method for targeted, anti-apoptotic gene therapy of corneal endothelial cells (CECs). Materials & methods: Magnetofection (MF), a combination of lipofection with magnetic nanoparticles (MNPs; PEI-Mag2, SO-Mag5, PalD1-Mag1), was tested in human CECs and in explanted human corneas. Effects on cell viability and function were investigated. Immunocompatibility was assessed in human peripheral blood mononuclear cells. Results: Silica iron-oxide MNPs (SO-Mag5) combined with X-tremeGENE-HP achieved high transfection efficiency in human CECs and explanted human corneas, without altering cell viability or function. Magnetofection caused no immunomodulatory effects in human peripheral blood mononuclear cells. Magnetofection with anti-apoptotic P35 gene effectively blocked apoptosis in CECs. Conclusion: Magnetofection is a promising tool for gene therapy of corneal endothelial cells with potential for targeted on-site delivery.
Endothelial cell damage often occurs in vascular disease such as atherosclerosis resulting in loss of vasoregulation and/or thrombosis. To restore endothelial function we have established novel methods to either combine site-specific endothelial cell positioning with lentiviral transduction in arteries or directly transduce the vascular endothelium in situ. Therefore, we have designed a special magnetic device to obtain a radially symmetric endothelial cell or lentivirus deposition on the vascular wall. Lentivirus is coupled to magnetic nanoparticles (MNPs) enabling the efficient transduction of endothelial cells by application of magnetic force. As a proof of concept we show that bovine pulmonary arterial endothelial cells (bPAECs) and human umbilical vein endothelial cells (HUVECs) are efficiently transduced with complexes of MNPs and lentiviral vectors carrying a GFP expression cassette. These cells can be positioned in a radially symmetric manner in an ex vivo flow-loop system. Moreover, this technique also allows for the direct lentiviral transduction of the murine endothelium in situ, which is proven by GFP expression in the vessel after 4–6 days in culture. We plan to use this approach in combination with the application of therapeutic genes e.g. the endothelial nitric oxide synthase (eNOS) to restore vascular endothelial function ex vivo and in vivo.
Abstract Implant-associated infections are a challenging problem in surgery. Bacteria in biofilms are difficult to treat as they are less susceptible to antibiotics or antiseptics which require high drug concentrations at the site of infection. We present a novel strategy to concentrate high antibiotic doses systemically at the target site using newly developed antibiotic-functionalized nanoparticles directed by a magnetic drug-targeting system. The important and effective antibiotic gentamicin served as antimicrobial substance and was ionically or covalently attached to magnetic nanoparticles. Subsequently, the particles were characterized thoroughly. Anti-infective properties with regard to Staphylococcus aureus and the degree of cytotoxicity concerning human umbilical vein endothelial cells were determined. The enrichment of the magnetic nanoparticles at the surface of model tubes in circulatory experiments was investigated. We describe a promising technique for the loading of magnetic nanoparticles to treat systemic infections. Gentamicin-coated magnetic nanoparticles reduced bacterial growth even beyond pathologically relevant concentrations within 24 h. Excellent concentration independent biocompatibility was found for the nanoparticles themselves and we demonstrate that the magnetic nanoparticles can be navigated and concentrated on surfaces of model implants using a permanent magnetic field. Keywords: Gentamicinimplantmagnetic nanoparticlestargeted drug deliverybiofilms Acknowledgements We would like to thank Dr.-Ing. B. Gleich for his great assistance in technical questions regarding highly focused magnetic fields and magnetic field forces for targeting. Furthermore we acknowledge Dipl. Wirtsch.-Ing. H. Stephan and Dipl. Phys. W. Kraus (Neue Magnetodyn GmbH) for their technical help, contributions and inspiring discussions. Special thanks to Dr. C. Bergemann (Chemicell GmbH), who kindly provides the TargetMag, FluidMag and SiMag ferrofluids. The authors did not receive any payments or benefits from a commercial party related directly or indirectly to the subject of this article. This work was partially supported by a grant from the Bayerische Forschungsstiftung.
'/%3e%3cuse xlink:href='%23a' transform='rotate(45 400 250)'/%3e%3cuse xlink:href='%23a' transform='rotate(67.5 400 250)'/%3e%3cpath id='b' fill='%2385340a' d='M404.31 274.41c.453 9.054 5.587 13.063 4.579 21.314 2.213-6.525-3.124-11.583-2.82-21.22m-7.649-23.757 19.487 42.577-16.329-43.887'/%3e%3cuse xlink:href='%23b' transform='rotate(22.5 400 250)'/%3e%3cuse xlink:href='%23b' transform='rotate(45 400 250)'/%3e%3cuse xlink:href='%23b' transform='rotate(67.5 400 250)'/%3e%3c/g%3e%3cuse xlink:href='%23c' transform='rotate(90 400 250)'/%3e%3cuse xlink:href='%23c' transform='rotate(180 400 250)'/%3e%3cuse xlink:href='%23c' transform='rotate(270 400 250)'/%3e%3ccircle cx='400' cy='250' r='27.778' fill='%23f6b40e' stroke='%2385340a' stroke-width='1.5'/%3e%3cpath id='h' fill='%23843511' d='M409.47 244.06c-1.897 0-3.713.822-4.781 2.531 2.136 1.923 6.856 2.132 10.062-.219a7.333 7.333 0 0 0-5.281-2.312zm-.031.438c1.846-.034 3.571.814 3.812 1.656-2.136 2.35-5.55 2.146-7.687.437.935-1.495 2.439-2.067 3.875-2.094z'/%3e%3cuse xlink:href='%23d' transform='matrix(-1 0 0 1 800.25 0)'/%3e%3cuse xlink:href='%23e' transform='matrix(-1 0 0 1 800.25 0)'/%3e%3cuse xlink:href='%23f' transform='translate(18.862)'/%3e%3cuse xlink:href='%23g' transform='matrix(-1 0 0 1 800.25 0)'/%3e%3cpath fill='%2385340a' d='M395.75 253.84c-.913.167-1.563.977-1.563 1.906 0 1.062.878 1.906 1.938 1.906a1.89 1.89 0 0 0 1.563-.812c.739.556 1.764.615 2.312.625.084.002.193 0 .25 0 .548-.01 1.573-.069 2.313-.625.36.516.935.812 1.562.812 1.06 0 1.938-.844 1.938-1.906 0-.929-.65-1.74-1.563-1.906.513.18.844.676.844 1.219a1.28 1.28 0 0 1-1.281 1.281c-.68 0-1.242-.54-1.282-1.219-.208.417-1.034 1.655-2.656 1.719-1.622-.064-2.447-1.302-2.656-1.719-.04.679-.6 1.219-1.281 1.219a1.28 1.28 0 0 1-1.281-1.281c0-.542.33-1.038.843-1.219zm2.09 5.69c-2.138 0-2.983 1.937-4.906 3.219 1.068-.427 1.91-1.27 3.406-2.125 1.496-.855 2.772.187 3.625.187h.031c.853 0 2.13-1.041 3.625-.187 1.497.856 2.369 1.698 3.438 2.125-1.924-1.282-2.8-3.219-4.938-3.219-.426 0-1.271.23-2.125.656h-.031c-.853-.426-1.698-.656-2.125-.656z'/%3e%3cpath fill='%2385340a' d='M397.12 262.06c-.844.037-1.96.207-3.563.688 3.848-.855 4.697.437 6.407.437h.03c1.71 0 2.56-1.292 6.407-.438-4.274-1.282-5.124-.437-6.406-.437h-.031c-.802 0-1.437-.312-2.844-.25z'/%3e%3cpath fill='%2385340a' d='M393.75 262.72c-.248.003-.519.005-.813.031 4.488.428 2.331 3 7.032 3h.03c4.702 0 2.575-2.572 7.063-3-4.7-.426-3.214 2.344-7.062 2.344h-.031c-3.608 0-2.496-2.421-6.22-2.375zm10.1 6.94a3.848 3.848 0 0 0-3.846-3.846 3.848 3.848 0 0 0-3.847 3.846 3.955 3.955 0 0 1 3.847-3.04 3.952 3.952 0 0 1 3.846 3.04z'/%3e%3cpath id='e' fill='%2385340a' d='M382.73 244.02c4.915-4.273 11.11-4.915 14.53-1.709.837 1.121 1.373 2.32 1.593 3.57.43 2.433-.33 5.062-2.236 7.756.215-.001.643.212.856.427 1.697-3.244 2.297-6.577 1.74-9.746a13.815 13.815 0 0 0-.67-2.436c-4.7-3.845-11.11-4.272-15.81 2.138z'/%3e%3cpath id='d' fill='%2385340a' d='M390.42 242.74c2.777 0 3.419.642 4.7 1.71 1.284 1.068 1.924.854 2.137 1.068.213.215 0 .854-.426.64s-1.284-.64-2.564-1.708c-1.283-1.07-2.563-1.069-3.846-1.069-3.846 0-5.983 3.205-6.41 2.991-.426-.214 2.137-3.632 6.41-3.632z'/%3e%3cuse xlink:href='%23h' transform='translate(-19.181)'/%3e%3ccircle id='f' cx='390.54' cy='246.15' r='1.923' fill='%2385340a'/%3e%3cpath id='g' fill='%2385340a' d='M385.29 247.44c3.633 2.778 7.265 2.564 9.402 1.282 2.136-1.282 2.136-1.709 1.71-1.709-.427 0-.853.427-2.564 1.281-1.71.856-4.273.856-8.546-.854z'/%3e%3c/svg%3e)
