Liposomal nanotechnology provides a versatile platform for exploring several approaches that can potentially enhance the delivery and targeting of therapies to tumors. As a biodegradable and essentially nontoxic platform, liposomes can be used to encapsulate both hydrophilic and hydrophobic materials and be utilized as drug carriers in drug delivery systems (DDSs). In addition, liposomes can be used to carry radioactive moieties, such as radiotracers, which can be bound at multiple locations within liposomes, making them Inhibitors,research,lifescience,medical attractive carriers for molecular imaging applications. In this study, gelatinase-binding peptides were attached to liposomes for synthesizing a targeted drug

delivery vehicle. For active targeting or drug delivery applications or both, intraliposomal encapsylation of multiple targeting agents or therapies can be (i) to the lipid bilayer, which can bind hydrophobic conjugates; (ii) to hydrated compartments for water-soluble components; (iii) by covalent binding directly or by utilizing spacer to the outer lipid leaflet [1]. Delivery of Inhibitors,research,lifescience,medical these nanoformulations to the reticuloendothelial system (RES) is Inhibitors,research,lifescience,medical readily achieved since, given their larger size, the RES traps

most conventional liposomes that are not shielded by polyethylene glycol chains (PEGs) or other similar steric water carrying substance. RES uptake can be increased by altering particle surface chemistry and charge, for instance, by adding positively charged lipids or biologically activating proteins or sugars on the surface of the liposomes. For purposes of agent delivery to target organs other than the RES, long-circulating Inhibitors,research,lifescience,medical liposomes have been developed by modifying the liposomal surface [2]. Determination of the in vivo biodistribution and targeting kinetics of liposome-encapsulated drugs is required for the assessment of drug bioavailability. The most commonly used nanoformulated drug is Caelyx/Doxil, a liposomal doxorubicin product. It has nearly Inhibitors,research,lifescience,medical supplanted doxorubicin in the therapy of ovarian cancer, breast cancer,

and Kaposi’s sarcoma. It differs from the former generation liposomal delivery systems, as the outer surface of Caelyx/Doxil is coated Annual Reviews with PEG chains that protect the liposomes from being opsonized by components of the immune system in the circulation. These stealth-type liposomes have longer circulation half-times than those for uncoated liposomes. In addition, they are safer than the native drugs chemical structure themselves (e.g., Caelyx/Doxil is not cardiotoxic, a major concern for native doxorubicin delivery). For cancer-based applications, peptides that can selectively detect and target metastatic disease and tumor invasive potential may offer critical prognostic information. Metastatic invasion is promoted by the attachment of tumor cells to the extracellular matrix, the degradation of matrix components by tumor-associated proteases, and the cellular movement into the area modified by protease activity.