SBIR-STTR Award

Magnetic beads have gained increasing use as a convenient separation technique for many forms of cell, nucleic acid and protein isolations and analyses. In particular, the manufacturers of clinical immunoassays utilize magnetic beads both as a solid support for antibodies specifically targeted to analytes of clinical importance, and as the separation means to isolate and detect those bound analytes. But use of magnetic beads imposes a paradox. The magnetic beads must have sufficient size - normally on the order of several microns in diameter - in order to be separated in an easily achievable magnetic field. But magnetic beads of this size diffuse only very slowly, and present limited surface area for antibody binding compared to their volume. Thus the size of the current magnetic beads limits the speed and sensitivity that can be achieved in clinical assays. Through advances in template-directed polymer synthesis and nanotechnology, a new class of"smart"magnetic nanoparticles can be made. These magnetic nanoparticles can change from a monodispersed small diameter particle of roughly 20 nanometers diameter to a macro- aggregate of microns diameter in response to an environmental stimulus like a temperature or pH change. By using these advanced nanomaterials, assays can be developed in which the high surface to volume ratio and the small size / high diffusion of the smart magnetic nanoparticles provides for higher sensitivity and faster binding reactions compared to current magnetic bead reagents. And then a discrete pH or temperature stimulus can cause these nanoparticle reagents to co-aggregate into a macro-aggregate of micron dimensions which can be separated by a magnetic field as easily and quickly as currently used magnetic beads. This project will develop such"smart"assay reagents and then demonstrate their value in a model p24 (HIV) protein immunoassay. These materials present the promise of faster, more sensitive clinical immunoassays for important biomarkers of cardiac disease, cancer, endocrine and infectious diseases.

Public Health Relevance:
There exist many examples, such as assays for thyroglobulin or troponin, where increases in the sensitivity of clinical assays has led to a richer understanding of a disease state and to better medical management of patients. There are also examples, such as intra-operative thyroid stimulating hormone assays, where a faster assay leads to decreased time under anesthesia and obvious patient benefit. This project evaluates the promise of a newly developed smart reagent to enable more sensitive and faster clinical assays, and thus to contribute to better medical care.

Magnetic beads have gained increasing use as a convenient separation technique for many forms of cell, nucleic acid and protein isolations and analyses. In particular, the manufacturers of clinical immunoassays utilize magnetic beads both as a solid support for antibodies specifically targeted to analytes of clinical importance, and as the separation means to isolate and detect those bound analytes. But use of magnetic beads imposes a paradox. The magnetic beads must have sufficient size - normally on the order of several microns in diameter - in order to be separated in an easily achievable magnetic field. But magnetic beads of this size diffuse only very slowly, and present limited surface area for antibody binding compared to their volume. Thus the size of the current magnetic beads limits the speed and sensitivity that can be achieved in clinical assays. Through advances in template-directed polymer synthesis and nanotechnology, a new class of magnetic nanoparticles can be made. These magnetic nanoparticles, bearing stimuli-responsive polymers, can change from a monodispersed small diameter particle of roughly 20 nanometers diameter to a macro- aggregate of microns diameter in response to an environmental stimulus like a temperature or pH change. By using these advanced nanomaterials, assays can be developed in which the high surface area to volume ratio and the small size / high diffusion of the magnetic nanoparticles provides for higher sensitivity and faster binding reactions compared to current magnetic bead reagents. And then a discrete pH or temperature stimulus can cause these nanoparticle reagents to rapidly co-aggregate into a macro-complex of micron dimensions which can be separated by a magnetic field as easily and quickly as currently used magnetic beads. This project will develop, optimize, and begin scale-up of these unique assay reagents, and will then demonstrate their value in a model p24 (HIV) protein immunoassay. Phase II of this project will also demonstrate the ability to multiplex various types of HIV tests using these reagents, and demonstrate the potential of removing serum interferences for certain important clinical analytes. The HIV target assay of this project is only a model. These materials present the promise of faster, more sensitive clinical immunoassays for important biomarkers of cardiac disease, cancer, endocrine disorders and other infectious diseases. The multiplex capabilities of these reagents and the potential for removal of serum interferences will be broadly applicable to other clinically important analytes.

Public Health Relevance Statement:


Public Health Relevance:
Laboratory tests to identify infectious diseases, and cardiac markers, and cancer markers, have to be as sensitive as possible in order to enable appropriate medical management of patients. There has been a consistent evolution of these tests to greater and greater sensitivity, and thus better patient care. This project is developing a whole new category of chemical reagents to improve these tests further and to enhance their speed and sensitivity.

Project Terms:
Address; Agreement; anti-IgG; Antibodies; antibody conjugate; antigen binding; Archives; Area; Automation; Binding (Molecular Function); Biological Assay; Biological Markers; Biological Sciences; Blood Plasma Volume; Caliber; Cardiac; Categories; Cells; Chemicals; Chemistry; Clinical; Communicable Diseases; Complex; Cyanovirin-N; Data; Diagnostic; Diffuse; Diffusion; Dimensions; Endocrine System Diseases; Engineering; Enzyme-Linked Immunosorbent Assay; Evolution; Excision; Generations; Goals; Healthcare; Heart Diseases; HIV; HIV Core Protein p24; HIV-1; HIV-2; Human Chorionic Gonadotropin; Human immunodeficiency virus test; Immunoassay; Immunoglobulin G; improved; In Vitro; innovation; Intellectual Property; Laboratories; Lead; Libraries; Licensing; magnetic beads; magnetic field; Magnetism; Malignant Neoplasms; Manufacturer Name; Medical; Modeling; nanomaterials; nanometer; nanoparticle; Nanotechnology; Nature; novel; Nucleic Acid Amplification Tests; Nucleic Acids; Outcome; particle; pathogen; Patient Care; Patients; Performance; Phase; Plasma; polymerization; Polymers; Preparation; Process; Production; Property; Proteins; public health relevance; Reaction; Reaction Time; Reagent; Recombinants; Relative (related person); Research Personnel; response; Sales; Sampling; scale up; Serum; Solid; Solutions; Specificity; Specimen; Specimen Handling; Speed (motion); Stimulus; Sulfhydryl Compounds; Surface; System; Techniques; Technology; Temperature; Testing; Viral Load result; Virion