Education

• PhD, University of Nottingham, 1981

• BsC, Trent College, 1975

Specialties
Biological Materials
Drug Delivery
Nanomaterial manufacturing and characterization
Polymer and Protein Engineering

Research Interests

Dr. Needham's research program combines the fields of Materials Science with Colloid and Surface Chemistry focusing on "Biological and other Soft Wet Materials". 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: 1) 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 2) Novel thermally sensitive drug delivery system for treatment of solid tumors. Research topics currently under investigation include: lipid and surfactant monolayers at gas bubble, and liquid emulsion surfaces; diffusion-solubility, crystallization and solidification of polymers, lipids, proteins, inorganic crystals and drugs from 2 phase Microsystems, including degradable PLGA polymer microspheres. 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 Univ. UK.