Professor Needham also holds appointments as Associate Professor of Biomedical Engineering; Associate Professor, Center for Bioinspired materials and material Systems, and the Center for Biomolecular and Tissue Engineering; and Associate Professor, Duke Comprehensive Cancer Center.
Needham's Lab uses a platform technology of micropipette manipulation to manipulate single and pairs of micro particles in order to assess their behavior in well defined fluids and excipient concentrations. He brings a wealth of expertise in micromanipulation, colloid stability, and drug delivery formulation.
The program is in the general area of forming, coating and encapsulation of solid, liquid and gaseous particles in the colloidal size range (10 nanometers to 10 micrometers). It deals more specifically with the material properties of 2-phase micro and nanosystems, such as surfactants, lipid monolayers, lipid bilayer membranes, micelles, liposomes, hydrogels, wax particles, emulsions, microdroplets, gas bubbles, microcrystals, microglasses, polymer microspheres, and blood and cancer cells.
It is also concerned with the adhesion and repulsion between particle surfaces involving molecular structures at interfaces including repulsive interactions due to the presence of grafted water-soluble polymers and specific interactions between receptors-ligand pairs. Such materials property measurements and inter particle interactions require specialized experimental equipment and the principal experimental approach is that of micropipet manipulation, to manipulate individual and pairs of micro particles and cells in controlled solution environments.
Previous NIH/NCI research grants, focused on experiments and theory concerning:
- Molecular exchange and defect formation in lipid vesicle membranes, (specifically involving the partitioning of amphipathic molecules like surfactants, drugs, pH sensitive polymers, and fusogenic peptides); and
- Novel thermally sensitive drug delivery system for treatment of solid tumors.
The latter is currently funded through an NIH grant entitled, "Microsphere Engineering for Proteins as Drugs". Particular applications of these materials and materials processing concepts are in drug delivery, specifically, the temperature-triggered drug release in solid tumors, and lately formulations of more hydrophobic drugs as emulsions and of proteins in polymer microspheres. Information gained in this work is directed towards, for example, improved image contrast agents, drug delivery systems that use lipids and polymers to create micro- and nano-capsules and monolayer coatings.
The Temperature-sensitive liposome systems are being tested pre-clinically and now clinically with collaborators in the Duke Medical Center, specifically with Dr. Mark Dewhirst in Radiation Oncology. New research is focusing on organic-inorganic nano composites derived from simple surfactants, and new bilayer model systems for studying and using single protein channel activity with Collaborators at Oxford University in the United Kingdom.