Annexing Blood-Brain Barrier for Targeted Drug Delivery Designed for Brain Instigated Pathologies; An Application of Solid Lipid Nanoparticles

Abstract

In terms of brain pathologies, the major obstacle for treatment is due to insufficient transport of drugs across the blood brain barrier. This barrier is basically the junctions between endothelial cells and neurons of brain. Drug transport is halted due to the tight junctions present between the endothelium cells which are not permeable for most of the entities. This has beneficial role in preventing pathogens and toxic materials to reach brain but have disadvantage during treatment when most of the drug molecules are prevented to cross the blood to brain barrier. Viewing this factor, it is very important to devise a system that is capable and efficient enough to transport therapeutic drug to brain. Emergence of nanotechnology has paved way to overcome such obstacle through formulation of solid lipid nanoparticle as a carrier. Just like a vehicle, SLNPs have the ability to encapsulate transporting entity within its core and transport it to that area. Over the decade SLNP has proved to deliver drugs for other pathologies. In this case test drug diosgenin has been in focus due to its anti-cancer and anti-inflammatory properties. As it’s a natural extract of plant it showed higher effectivity and low toxicity in many studies. In this study, polysorbate-80 coated stearic acid SLNP were formulated with and without drug encapsulation. These SLNP were characterized through SEM, FTIR, XRD and HPLC. This formulation was then tested in-vitro and in-vivo. U87 MG cell lines were used in order to check the anti-cancer effect (MTT assay) by using blank SLNP, diosgenin only and diosgenin SLNP. Cell scratch assay was used with the IC-50 of the above formulations in order to check its anti-metastatic effect on glioma cells. Then sickness model were formed by injecting Concanavalin-A into mice and treating them with PBS, Fluoxetine, Diosgenin, xviiiAbstract blank SLNP and diosgenin SLNP. These groups were then undergone behavioral analysis to assess its behavior and effectivity of treatment. Open field test, elevated maze plus, social interaction, grooming test, tail suspension test and forced swim test were performed for analysis of their behavior. Histological sectioning and staining were performed on mice brains for anti-inflammatory response analysis in different groups of mice. Drug levels were analyzed in different organs and blood of mice through spectrophotometry. The characterization SLNP showed desired size with anionic charge which has encapsulated diosgenin in its core. The in-vitro assays showed the anti-proliferative activity of SLNP with and without drug and diosgenin exhibited high cytotoxicity level than diosgenin SLNP and blank SLNP. This suggests that diosgenin is quite effective at low concentrations. The in-vivo tests showed that the treatment which were given to mice had healing effect in sickened mice. The group diosgenin and diosgenin with SLNP showed higher level of social interaction and exploratory behavior than others. Which were further proved by the histology that the inflammation was controlled in these treated mice than the Con-A group. The blood tests proved that diosgenin is not toxic to cells. These tests and assays showed that diosgenin as a drug has potential for controlling glioma proliferation and showed quite high anti-inflammatory responses in mice.