DescriptionNanotechnology is an emerging field with the promise for new materials and applications, particularly in the medical field for diagnosis and treatment of disease. The high surface area to volume ratio of nanoparticles gives rise to useful material properties such as enhanced solubility and dissolution for drug nanoparticles as well as superparamagnetism in the case of magnetic nanoparticles. Often, nanoparticle interactions with surfactants and polymers arise in a variety of scenarios: the production and stabilization to reduce particle agglomeration, to aid in nanoparticle delivery to specific areas of the body, increase bioavailability by avoiding body clearance mechanisms, add desired functionality, and finally the biological targets of nanoparticles are often the surfactants (lipids of the cell membrane) or polymers (proteins) of the body. Understanding the interfacial interactions of nanoparticles with polymers or surfactants is therefore crucial in proceeding ahead with nanoparticles as viable options for medical treatments. In this dissertation, a series of computational techniques are employed to elucidate the interfacial interactions at the molecular level between surfactants, polymers, ii and nanoparticles in three different case studies. First, Molecular Dynamics and Dissipative Particle Dynamics simulation methods are used to study the stability of a model cell membrane to an applied stress in order to mimic the interactions that occur in magnetic fluid hyperthermia, a nanoparticle-based treatment for cancerous tumors. Here, the aim is to determine if magnetic nanoparticles are capable of generating mechanical forces sufficient to rupture a cell membrane. Secondly, coarse-grained Molecular Dynamics is utilized to explore the interaction of micelle-forming amphiphilic molecules interacting with the human scavenger receptor A for use in preventing uptake of oxidized low-density lipoproteins. Finally, Monte Carlo simulations are developed to study nanocrystal nucleation from solution in the presence of polymers to determine factors that act to promote or inhibit nucleation. iii