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Contact Details

Phone
+64 3 479 7133
Email
greg.walker@otago.ac.nz
Position
Associate Professor Head of the Bayer Centre for Dairy Animal Health / Pharmaceutical Science and Product Innovations at the School of Pharmacy (2019-present)
Qualifications
BSc MSc PhD(Otago)
Research summary
Drug delivery and formulation
Teaching
  • PHCY211: Fundamental Pharmaceutical Sciences (Dosage forms module coordinator)
  • PHCY220: Integrated modules A
  • PHCY430: Elective Projects B
  • PHCY485: Honours
Memberships
  • Controlled Release Society (2012-present)
  • New Zealand Chapter of the Controlled Release Society (2012 to present): President of the Society (November 2017 to present)

Research

Associate Professor Walker’s general area of research interest is in formulation and delivery of bioactive molecules. Particular interests are in physico-chemical principles relating to how delivery systems can influence the absorption, disposition and fate of bioactives in the body and how such systems can increase the efficacy of bioactives.

He has extensive experience in polymeric drug delivery systems, engineering formulations for biopharmaceuticals, project management and pre-clinical studies.

Prior to joining University of Otago as a lecturer, he was the Research and Development Manager at a UK biotech company where he invented the lead technology of a new class of topical haemostat (PeproStat) which has completed successful phase two clinical trials.

As head of the Bayer Centre for Dairy Animal Health / Pharmaceutical Science and Product Innovations at the School of Pharmacy, he applies his formulation and drug delivery expertise to issues relating to veterinary and animal health.

Associate Professor Walker is a key researcher in three Ministry of Business, Innovation and Employment (MBIE) grants totalling to over NZ $19 million. These projects focus on the formulation and delivery of: vaccines, a new class of antimicrobials and bioactives to crops.

PhD projects are available, please contact me if you are interested in conducting PhD research in the field of formulation and drug delivery.

Publications

Nguyen, H. V., Campbell, K., Painter, G. F., Young, S. L., & Walker, G. F. (2022). Effect of carrier molecular weight on physicochemical properties and the in vitro immune-stimulatory activity of the CpG-dextran conjugates. International Journal of Pharmaceutics, 627, 122236. doi: 10.1016/j.ijpharm.2022.122236

Liu, W., Price, S., Bennett, G., Maxwell, T. M. R., Zhao, C., Walker, G., & Bunt, C. (2022). A landscape review of controlled release urea products: Patent objective, formulation and technology. Journal of Controlled Release, 348, 612-630. doi: 10.1016/j.jconrel.2022.06.009

McLaughlin, A. W., McDowell, A., Clarkson, A. N., & Walker, G. F. (2022). Characterization of poly(lactic-co-glycolic acid) nanofibers electrospun using a sustainable green chemistry with a low toxicity solvent system. International Journal of Polymeric Materials & Polymeric Biomaterials, 71(13), 983-992. doi: 10.1080/00914037.2021.1933976

Bērziņš, K., Fraser-Miller, S. J., Walker, G. F., Rades, T., & Gordon, K. C. (2021). Investigation on formulation strategies to mitigate compression-induced destabilization in supersaturated celecoxib amorphous solid dispersions. Molecular Pharmaceutics, 18, 3882-3893. doi: 10.1021/acs.molpharmaceut.1c00540

Liu, W., Walker, G., Price, S., Yang, X., Li, J., & Bunt, C. (2021). Electrospun membranes as a porous barrier for molecular transport: membrane characterization and release assessment. Pharmaceutics, 13(6), 916. doi: 10.3390/pharmaceutics13060916

McLaughlin, A. W., McDowell, A., Clarkson, A. N., & Walker, G. F. (2022). Characterization of poly(lactic-co-glycolic acid) nanofibers electrospun using a sustainable green chemistry with a low toxicity solvent system. International Journal of Polymeric Materials & Polymeric Biomaterials, 71(13), 983-992. doi: 10.1080/00914037.2021.1933976

Journal - Research Article

Nguyen, H. V., Campbell, K., Painter, G. F., Young, S. L., & Walker, G. F. (2022). Effect of carrier molecular weight on physicochemical properties and the in vitro immune-stimulatory activity of the CpG-dextran conjugates. International Journal of Pharmaceutics, 627, 122236. doi: 10.1016/j.ijpharm.2022.122236

Journal - Research Article

Bērziņš, K., Fraser-Miller, S. J., Walker, G. F., Rades, T., & Gordon, K. C. (2021). Investigation on formulation strategies to mitigate compression-induced destabilization in supersaturated celecoxib amorphous solid dispersions. Molecular Pharmaceutics, 18, 3882-3893. doi: 10.1021/acs.molpharmaceut.1c00540

Journal - Research Article

Campbell, K., Young, V. L., Donaldson, B. C., Woodall, M. J., Shields, N. J., Walker, G. F., Ward, V. K., & Young, S. L. (2021). Delivering two tumour antigens survivin and mucin-1 on virus-like particles enhances anti-tumour immune responses. Vaccines, 9(5), 463. doi: 10.3390/vaccines9050463

Journal - Research Article

Davison, E. K., McGowan, J. E., Li, F. F., Harper, A. D., Young Jeong, J., Mros, S., Harbison-Price, N., Van Zuylen, E. M., Knottenbelt, M. K., Heikal, A., Ferguson, S. A., McConnell, M. A., Cook, G. M., Krittaphol, W., Walker, G. F., … Rennison, D. (2021). C-2 derivatized 8-sulfonamidoquinolines as antibacterial compounds. Bioorganic & Medicinal Chemistry, 29, 115837. doi: 10.1016/j.bmc.2020.115837

Journal - Research Article

Dowlath, S., Campbell, K., Al-Barwani, F., Young, V. L., Young, S. L., Walker, G. F., & Ward, V. K. (2021). Dry formulation of virus-like particles in electrospun nanofibers. Vaccines, 9(3), 213. doi: 10.3390/vaccines9030213

Journal - Research Article

Liu, W., Walker, G., Price, S., Yang, X., Li, J., & Bunt, C. (2021). Electrospun membranes as a porous barrier for molecular transport: membrane characterization and release assessment. Pharmaceutics, 13(6), 916. doi: 10.3390/pharmaceutics13060916

Journal - Research Article

McGowan, J. E., Harper, A. D., Davison, E. K., Jeong, J. Y., Mros, S., Harbison-Price, N., Van Zuylen, E. M., Knottenbelt, M. K., Heikal, A., Ferguson, S. A., McConnell, M. A., Cook, G. M., Krittaphol, W., Walker, G. F., … Rennison, D. (2020). Substituted sulfonamide bioisosteres of 8-hydroxyquinoline as zinc-dependent antibacterial compounds. Bioorganic & Medicinal Chemistry Letters, 30, 127110. doi: 10.1016/j.bmcl.2020.127110

Journal - Research Article

Nguyen, H. V., Campbell, K., Painter, G. F., Young, S. L., & Walker, G. F. (2020). Nanoparticle system based on amino-dextran as a drug delivery vehicle: Immune-stimulatory CpG-oligonucleotide loading and delivery. Pharmaceutics, 12, 1150. doi: 10.3390/pharmaceutics12121150

Journal - Research Article

Poller, B., Painter, G. F., & Walker, G. F. (2019). Influence of albumin in the microfluidic synthesis of PEG-PLGA nanoparticles. Pharmaceutical Nanotechnology, 7, 460-468. doi: 10.2174/2211738507666191023091938

Journal - Research Article

Zawari, M., Poller, B., Walker, G., Pearson, A., & Carr, A. C. (2019). Formulation of broccoli sprout powder in gastro-resistant capsules protects against the acidic pH of the stomach in vitro but does not increase isothiocyanate bioavailability in vivo. Antioxidants, 8(9), 359. doi: 10.3390/antiox8090359

Journal - Research Article

Kramer, K., Shields, N. J., Poppe, V., Young, S. L., & Walker, G. F. (2017). Intracellular cleavable CpG oligodeoxynucleotide-antigen conjugate enhances anti-tumor immunity. Molecular Therapy, 25(1), 62-70. doi: 10.1016/j.ymthe.2016.10.001

Journal - Research Article

Kramer, K., Young, S. L., & Walker, G. F. (2017). Comparative study of 5′- and 3′-linked CpG–antigen conjugates for the induction of cellular immune responses. ACS Omega, 2(1), 227-235. doi: 10.1021/acsomega.6b00368

Journal - Research Article

Poller, B., Strachan, C., Broadbent, R., & Walker, G. F. (2017). A minitablet formulation made from electrospun nanofibers. European Journal of Pharmaceutics & Biopharmaceutics, 114, 213-220. doi: 10.1016/j.ejpb.2017.01.022

Journal - Research Article

Smith, G. P. S., McLaughlin, A., Clarkson, A. N., Gordon, K. C., & Walker, G. F. (2017). Raman microscopic imaging of electrospun fibers made from a polycaprolactone and polyethylene oxide blend. Vibrational Spectroscopy, 92, 27-34. doi: 10.1016/j.vibspec.2017.05.002

Journal - Research Article

Walker, G., Römann, P., Poller, B., Löbmann, K., Grohganz, H., Rooney, J. S., Huff, G. S., Smith, G. P. S., Rades, T., Gordon, K. C., Strachan, C. J., & Fraser-Miller, S. J. (2017). Probing pharmaceutical mixtures during milling: The potency of low frequency Raman spectroscopy in identifying disorder. Molecular Pharmaceutics, 14(12), 4675-4684. doi: 10.1021/acs.molpharmaceut.7b00803

Journal - Research Article

Yarragudi, S. B., Richter, R., Lee, H., Walker, G. F., Clarkson, A. N., Kumar, H., & Rizwan, S. B. (2017). Formulation of olfactory-targeted microparticles with tamarind seed polysaccharide to improve nose-to-brain transport of drugs. Carbohydrate Polymers, 163, 216-226. doi: 10.1016/j.carbpol.2017.01.044

Journal - Research Article

DeRouchey, J., Schmidt, C., Walker, G. F., Koch, C., Plank, C., Wagner, E., & Rädler, J. O. (2008). Monomolecular assembly of siRNA and Poly(ethylene glycol)—peptide copolymers. Biomacromolecules, 9(2), 724-732. doi: 10.1021/bm7011482

Journal - Research Article

Fella, C., Walker, G. F., Ogris, M., & Wagner, E. (2008). Amine-reactive pyridylhydrazone-based PEG reagents for pH-reversible PEI polyplex shielding. European Journal of Pharmaceutical Sciences, 34(4-5), 309-320. doi: 10.1016/j.ejps.2008.05.004

Journal - Research Article

Knorr, V., Allmendinger, L., Walker, G. F., Paintner, F. F., & Wagner, E. (2007). An acetal-based PEGylation reagent for pH-sensitive shielding of DNA polyplexes. Bioconjugate Chemistry, 18, 1218-1225. doi: 10.1021/bc060327a

Journal - Research Article

Ledger, R., Tucker, I. G., & Walker, G. F. (2002). Quantitative capillary electrophoresis assay for the proteolytic stability of luteinizing hormone-releasing hormones. Journal of Chromatography B, 769, 235-242.

Journal - Research Article

Ledger, R., Tucker, I. G., & Walker, G. F. (2002). The metabolic barrier of the lower intestinal tract of salmon to the oral delivery of protein and peptide drugs. Journal of Controlled Release, 85, 91-103.

Journal - Research Article

Walker, G. F., Ledger, R., & Tucker, I. G. (2001). Activity of pancreatic endopeptidases towards luteinizing hormone-releasing hormones. International Journal of Pharmaceutics, 216, 77-82.

Journal - Research Article

Walker, G., Ledger, R., & Tucker, I. G. (1999). Garbomer inhibits tryptic proteolysis of luteinizing hormone-releasing hormone and N-alpha-benzoyl-L-arginine ethyl ester by binding the enzyme. Pharmaceutical Research, 16(7), 1074-1080.

Journal - Research Article

Liu, W., Price, S., Bennett, G., Maxwell, T. M. R., Zhao, C., Walker, G., & Bunt, C. (2022). A landscape review of controlled release urea products: Patent objective, formulation and technology. Journal of Controlled Release, 348, 612-630. doi: 10.1016/j.jconrel.2022.06.009

Journal - Research Other

Nguyen, H. V., Campbell, K., Painter, G. F., Young, S. L., & Walker, G. F. (2021). Data on the uptake of CpG-loaded amino-dextran nanoparticles by antigen-presenting cells [Data article]. Data in Brief, 35, 106883. doi: 10.1016/j.dib.2021.106883

Journal - Research Other

Kramer, K., Young, S. L., & Walker, G. F. (2019). Data on the uptake of reducible antigen-adjuvant conjugates by dendritic cells [Data article]. Data in Brief, 23, 103759. doi: 10.1016/j.dib.2019.103759

Journal - Research Other

Donaldson, B., Lateef, Z., Walker, G. F., Young, S. L., & Ward, V. K. (2018). Virus-like particle vaccines: Immunology and formulation for clinical translation. Expert Review of Vaccines, 17(9), 833-849. doi: 10.1080/14760584.2018.1516552

Journal - Research Other

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