Laboratory of Nanomedicine

Nanoparticle Interaction with the Biological Milieu

Nanoparticle properties such as size, shape, surface charge, and surface functional groups dictate the interaction of nanoparticles with human body. As a consequence, these properties will affect nanoparticle pharmacokinetics, biodistribution, diffusivity through the extracellular matrix, and interaction on cellular and sub-cellular levels. A robust fundamental understanding of how nanoparticle properties influence interaction with the body on a sub-cellular, cellular, extracellular, and systemic level will be critical for developing safe nanomedicines for drug delivery or diagnostic applications.

Cellular Spheroids for Tissue Engineering

Magnetic particles, particularly iron oxide, have been used to manipulate cells and cellular spheroids (a spherical aggregate of cells) using magnetic forces, but often involve internalization and therefore adversely affect their use as tissue engineered building blocks. By developing a novel magnetic cellular spheroid that limits the interaction of magnetic nanoparticles and cells, these tissue building blocks maintain long-term cell viability and phenotype, thereby avoiding adverse effects related to magnetic nanoparticle use.  These magnetic cellular spheroids can be magnetically patterned to assemble fused complex tissue constructs of desired cellular and extracellular matrix content.

Rationally Designed Polymers for Controlled Drug Delivery and Imaging

Biodegradable and biocompatible polymers such as poly(lactide) are a preeminent class of biomaterials due to their well-characterized degradation properties and natural metabolism of degradation byproducts. However, the scope of their use is limited by their chemical structure. Therefore, developing rationally designed polymers that combine known and accepted polymeric biomaterials with novel modifications that impart new functionalities will expand the use of FDA-approved polymers for drug delivery and imaging applications.



Multifunctional Hybrid Nanoparticles for Controlled Drug Delivery and Imaging

Nanoparticles can be generally categorized as inorganic (gold nanoparticles, iron oxide nanoparticles, quantum dots, carbon nanotubes, hydroxyapatite) or organic (polymeric nanoparticles, liposomes, dendrimers). Often one category will have optimal properties for one application, but be limited in other areas. For example iron oxide particles have well known imaging capabilities (i.e. for MRI contrast) however they are limited as drug delivery vehicles, while polymeric nanoparticles have reached the clinical stage for drug delivery, but offer little potential as imaging agents. By synthesizing hybrid nanoparticles that merge both inorganic and polymeric domains, a novel theranostic nanoparticle system can be made, which combines therapy and diagnostics. Moreover combining inorganic and polymeric domains may provide interesting therapeutic possibilities. Specific indications for this research include controlled drug delivery for cancer therapy and for anabolic bone growth drugs.

Graphene-coated Nitinol for Biomedical Implants

Vascular stents are a means of increasing blood vessel patency with a small, often metallic, mesh tubes implanted endovascularly. While metallic alloys such as nitinol or stainless steel are often chosen for their superior mechanical properties, stents still fail at rates as high as 12% due to deployment complications, stent geometry, material properties, and surface coatings. Carbon-based coatings have been previously used to improve implant properties, however many are still limited in their efficacy as a functional stent material. Nitinol substrates coated with an atomically smooth graphene layer are expected to improve physiological response by 1) reducing protein adsorption on the surface. 2) Reducing the relative amount of fibrinogen adsorption, a protein involved in thrombus formation, compared to albumin, a serum protein. 3) Decreasing charge transfer from adsorbed proteins to the substrate, a physical process indicating protein conformational change. 4) Improving cell viability and morphology on the substrate.


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