Synthesis of New Hydrophobically Modified Starch Nanoparticles

Modified starches are native starches that have been chemically or physically altered in order to improve their properties for a specific utilization in the research or industry. Chemically modified starches can be cross-linked, esterified or converted to other forms by using acids or enzymes to have for instance: greater viscosity, clarity, etc. Potato starch, among other kind of starches, can be hydrophobically modified to become amphiphilic with surface active properties and useful to stabilize oil/water systems. The properties of hydrophobically modified starches are mainly based on the fact that their hydrophobic interactions lead them to self-associate. Hydrophobically modified starches are created by grafting a low quantity of hydrophobic groups to both amylose and amylopectin [1]. Recently, there has been a growing interest in hydrophobically modified derivatives of polysaccharides for biomedical applications. The amphiphilic nature imparted upon polysaccharides after hydrophobic modification gives them a wide and interesting application spectrum, for instance as rheology modifiers, emulsion stabilizers, surface modifiers for liposomes and nanoparticles, and also as drug delivery vehicles. Drug based nanoparticles are solids, colloidal particles consisting of macromolecular substances that vary in size from 10 to 1,000 nm [2]. In the drug delivery systems drug molecules is usually dissolved, entrapped, adsorbed, attached or encapsulated into the nanoparticle matrix [3,4]. In the present work, we have prepared the hydrophobically modified starch covalently bonded long-chain fatty acids in order to decrease its hydrophilicity. The desirable grafted starch was made into nanoparticle by dialysis method and the particle size distribution and morphology of the obtained particles were investigated using different techniques such as SEM and particle seizer in aqueous solution. The obtained results indicated the formation of micelles ranged from 300 to 700 nm in PS diagram