UM File # 2865
Injectable biodegradable polymeric particles (usually microspheres) represent an exciting approach to control the release of vaccine antigens to reduce the number of doses in the immunization schedule and optimize the desired immune response via selective targeting of antigen to antigen presenting cells. After the first couple of decades of their study, much progress has been made towards the clinical use of antigen-loaded microspheres. Poly (lactide-co-glycolic acids) (PLGAs) have been studied most commonly for this purpose because of their proven safety record and established use in marketed products for controlled delivery of several peptide drugs. PLGA microspheres have many desirable features relative to standard aluminum-based adjuvants, including the microspheres' ability to induce cell-mediated immunity, a necessary requirement for emergent vaccines against HIV and cancer. PLGA microparticles have displayed unprecedented versatility and safety to accomplish release of one or multiple antigens of varying physical-chemical characteristics and immunologic requirements, and have now met numerous critical benchmarks in development of long-lasting immunity after a single injected dose.
University of Michigan researchers have developed methods of encapsulating molecules such as biomacromolecules, including proteins, peptides, poly (nucleic acids) drugs, vaccine antigens, and so forth in pore-containing polymers. The methods involve placing a solution containing the biomacromolecule in contact with a polymer containing pores, or a solution containing the biomacromolecule in contact with a polymer, allowing the biomacromolecule to enter the pores, and then causing the pores to close, wherein the biomacromolecule is entrapped, encapsulated, or irreversibly absorbed in the polymer. The pore-containing polymer is not soluble in the encapsulation solution nor is the polymer dissolved during encapsulation, however the pore-containing polymer may be plasticized. Also see UMFiles 2151.1 and 4518.
Applications • Tissue engineering scaffolds and any type of biomaterial that requires the need to encapsulate molecules that do not strongly partition into the polymer phase, but in pores (typically aqueous as in biomaterials) of the polymer.
Advantages • Less expensive
Effects on the Controlled Release of ProteinsTechnology #2865
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UM File # 2865