Abstract
It is very important to apply drug delivery system (DDS) to modern medicine. Because DDS is useful for transplantation, regeneration and gene therapy. For example, cell transplantation using DDS may cover the shortness of donor for organ transplantation. Regeneration also needs high technology including DDS. Liposome is one of the most promising careers, and has a lot of possibility. Polyethylene glycol (PEG)-coated on the liposomal surface reduces the uptake by reticuloendothelial system to prolong the circulation in blood. As for active targeting following passive targeting to the target site, PEG-immunoliposomes were studied in terms of the targeting and receptor-mediated endocytosis into the target cells. Our data show PEG-immunoliposomes are more effective than PEG-liposomes for systemic fungal infection. Since non-viral vectors such as liposcme have fewer side effects than viral vectors, non-viral vectors are suitable to gene therapy for many patients with common diseases. Alternatively, poor transfection efficiency is the major drawback of non-viral vector. If the transfection efficiency can be improved, the non-viral vectors would have potential of becoming the vectors for choice for gene therapy. We revealed that addition of ligand nr lectin to liposome yields large enhancement of transfection efficiency in human lung cancer cells. These results indicated ligand or lectin-facilitated transfection is an efficient gene delivery strategy. Employment of cell type-specific ligands or lectins may allow for efficient cell type-specific gene targeting. Finally, DDS will be able to play an important role in the modern medicine as long as we keep the right way to use DDS for medicine.
