Due to the presence of multiple endogenous transporters, BBB allows a selective entry of nutrients and minerals across it and limits the entry of foreign substances like drugs as well as neuropharmaceutical agents. This makes the CNS treatment ineffective. The conventional drug delivery systems which release the drug into general circulation fail to deliver drugs effectively to brain and are, therefore, not very useful in treating certain diseases that affect CNS including Alzheimer’s disease, dementia, Parkinson’s disease, mood disorders,

AIDS, and viral and bacterial meningitis. Therefore, #check details keyword# there is a need to develop and design approaches which specifically target to brain in a better and effective way [24] (Figure Inhibitors,research,lifescience,medical 2). Figure 2 The antibodies of the immunoliposomes recognise the specific receptor of the BBB releasing the drug of the immunoliposomes only close to the targeting cells. Drug delivery to the brain is hindered by the presence of the CNS barriers. Although the BBB and B-CSFB restrict the passage of many substances, both

are actually selectively permeable to nutrients necessary for healthy brain function. In the last decades, despite the advances in drug discovery, there has been little improvement on the prognosis of patients with brain diseases, like cancer, neurodegenerative diseases, Inhibitors,research,lifescience,medical or neurological disorders. Often, in clinical trials it has been found that promising agents in vitro have little impact on the disease. These disappointing results can be, at least in part, explained by the inability to deliver therapeutic agents to the

brain across CNS barriers avoiding Inhibitors,research,lifescience,medical various resistance mechanisms to reach the desired targets [25]. 3. Liposomes Liposomes have received widespread attention as a carrier system for therapeutically active compounds, due to their unique characteristics such as capability to incorporate hydrophilic and hydrophobic drugs, good compatibility, low toxicity, lack of immune system activation, and targeted delivery of Inhibitors,research,lifescience,medical bioactive compounds to the site of actions [26]. Liposomes are spherical vesicles that resemble cells in that they contain an inner hydrophilic core and a relatively impermeable outer lipophilic phospholipid bilayer [22, Suplatast tosilate 27]. The lipid components of liposomes are predominantly phosphatidylcholine derived from egg or soybean lecithin [28]. Liposomes have been shown to provide stable encapsulation for various drugs and offer distinct advantages over unencapsulated agents; thus, liposomes have been proposed for use in a variety of applications in research, industry, and medicine, particularly for the use as carriers of diagnostic and therapeutic compounds (Figure 1). Liposomes are synthetic lipid spheres composed by fatty acid on polymers with a bilayered membrane structure surrounding an aqueous core that can be used to encapsulate small molecules.