ovalbumin and acrylic-acid

Hydrogels based upon terpolymers of methacrylic acid, N-vinyl pyrrolidone, and poly(ethylene glycol) are developed and characterized for their ability to respond to changes in environmental pH and to partition protein therapeutics of varying molecular weights and isoelectric points. P((MAA-co-NVP)-g-EG) hydrogels are synthesized with PEG-based cross-linking agents of varying length and incorporation densities. The composition is confirmed using FT-IR spectroscopy and shows peak shifts indicating hydrogen bonding. Scanning electron microscopy reveals microparticles with an irregular, planar morphology. The pH-responsive behavior of the hydrogels is confirmed under equilibrium and dynamic conditions, with the hydrogel collapsed at acidic pH and swollen at neutral pH. The ability of the hydrogels to partition model protein therapeutics at varying pH and ionic strength is evaluated using three model proteins: insulin, porcine growth hormone, and ovalbumin. Finally, the microparticles are evaluated for adverse interactions with two model intestinal cell lines and show minimal cytotoxicity at concentrations below 5 mg mL

Topics: Acrylates; Administration, Oral; Animals; Caco-2 Cells; Cell Death; Growth Hormone; HT29 Cells; Humans; Hydrogel, Polyethylene Glycol Dimethacrylate; Hydrogen-Ion Concentration; Insulin; Nephelometry and Turbidimetry; Osmolar Concentration; Ovalbumin; Polymethacrylic Acids; Povidone; Proteins; Spectroscopy, Fourier Transform Infrared; Sus scrofa; Thermogravimetry; Titrimetry

We evaluated the potential of poly(N-vinylacetamide-co-acrylic acid) modified with d-octaarginine, which is a typical cell-penetrating peptide, as a carrier for mucosal vaccine delivery. Mice were nasally inoculated four times every seventh day with PBS containing ovalbumin with or without the d-octaarginine-linked polymer. The polymer enhanced the production of ovalbumin-specific immunoglobulin G (IgG) and secreted immunoglobulin A (IgA) in the serum and the nasal cavity, respectively. Ovalbumin internalized into nasal epithelial cells appeared to stimulate IgA production. Ovalbumin transferred to systemic circulation possibly enhanced IgG production. An equivalent dose of the cholera toxin B subunit (CTB), which was used as a positive control, was superior to the polymer in enhancing antibody production; however, dose escalation of the polymer overcame this disadvantage. A similar immunization profile was also observed when ovalbumin was replaced with influenza virus HA vaccines. The polymer induced a vaccine-specific immune response identical to that induced by CTB, irrespective of the antibody type, when its dose was 10 times that of CTB. Our cell-penetrating peptide-linked polymer is a potential candidate for antigen carriers that induce humoral immunity on the mucosal surface and in systemic circulation when nasally coadministered with antigens.

Topics: Acetamides; Acrylates; Adjuvants, Immunologic; Administration, Intranasal; Animals; Antibody Formation; Antigens; Cell-Penetrating Peptides; Cholera Toxin; Drug Carriers; Drug Delivery Systems; Epithelial Cells; Female; Immunity, Humoral; Immunoglobulin A, Secretory; Immunoglobulin G; Influenza Vaccines; Mice; Mice, Inbred BALB C; Mucous Membrane; Nasal Mucosa; Ovalbumin; Pharmaceutical Solutions; Polymers; Polyvinyls; Vaccination; Vaccines

Protein-based vaccines have significant potential as infectious disease and anticancer therapeutics, but clinical impact has been limited in some applications by their inability to generate a coordinated cellular immune response. Here, a pH-responsive carrier incorporating poly(propylacrylic acid) (PPAA) was evaluated to test whether improved cytosolic delivery of a protein antigen could enhance CD8+ cytotoxic lymphocyte generation and prophylactic tumor vaccine responses. PPAA was directly conjugated to the model ovalbumin antigen via reducible disulfide linkages and was also tested in a particulate formulation after condensation with cationic poly(dimethylaminoethyl methacrylate) (PDMAEMA). Intracellular trafficking studies revealed that both PPAA-containing formulations were stably internalized and evaded exocytotic pathways, leading to increased intracellular accumulation and potential access to the cytosolic MHC-1 antigen presentation pathway. In an EG.7-OVA mouse tumor protection model, both PPAA-containing carriers robustly inhibited tumor growth and led to an approximately 3.5-fold increase in the longevity of tumor-free survival relative to controls. Mechanistically, this response was attributed to the 8-fold increase in production of ovalbumin-specific CD8+ T-lymphocytes and an 11-fold increase in production of antiovalbumin IgG. Significantly, this is one of the first demonstrated examples of in vivo immunotherapeutic efficacy using soluble protein-polymer conjugates. These results suggest that carriers enhancing cytosolic delivery of protein antigens could lead to more robust CD8+ T-cell response and demonstrate the potential of pH-responsive PPAA-based carriers for therapeutic vaccine applications.

Topics: Acrylates; Animals; Antigen Presentation; Antigens; Cancer Vaccines; CD8-Positive T-Lymphocytes; Cell Proliferation; Disease-Free Survival; Drug Delivery Systems; Endosomes; Female; Hydrogen-Ion Concentration; Immunoglobulin G; Lymphocyte Activation; Methacrylates; Mice; Mice, Inbred C57BL; Neoplasm Transplantation; Nylons; Ovalbumin; Polymers; Thymoma; Thymus Neoplasms; Treatment Outcome