Thompson, C.J., Tetley, L., Uchegbu, I.F. and Cheng, W.P. (2009) The complexation between novel comb shaped amphiphilic polyallylamine and insulin-Towards oral insulin delivery. International Journal of Pharmaceutics, 376(1-2), pp. 46-55. (doi: 10.1016/j.ijpharm.2009.04.014)
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Publisher's URL: http://dx.doi.org/10.1016/j.ijpharm.2009.04.014
Abstract
Novel amphiphilic polyallylamine (PAA) were previously synthesised by randomly grafting palmitoyl pendant groups and subsequent quaternising with methyl iodide. The ability of these self-assembled polymers to spontaneously form nano-complexes with insulin in pH 7.4 Tris buffer was evaluated by transmittance study, hydrodynamic size and zeta potential measurements. The transmission electron microscopy images showed that non-quaternised polymer complexes appeared to form vesicular structures at low polymer:insulin concentrations. However, at higher concentrations they formed solid dense nanoparticles. The presence of quaternary ammonium moieties resulted in insulin complexing on the surface of aggregates. All polymers exhibited high insulin complexation efficiency between 78 and 93%. Incubation with trypsin, alpha-chymotrypsin and pepsin demonstrated that most polymers were able to protect insulin against enzymatic degradation by trypsin and pepsin. Quaternised polymers appeared to have better protective effect against trypsinisation, possibly due to stronger electrostatic interaction with insulin. Interestingly, non-quaternised polymers significantly enhanced insulin degradation by alpha-chymotrypsin. All polymers were less cytotoxic than PAA, with the quaternised polymers exhibiting up to 15-fold improvement in the IC50 value. Based on these results, quaternised palmitoyl graft polyallylamine polymers showed promising potential as oral delivery systems for insulin.
| Item Type: | Articles |
|---|---|
| Keywords: | Oral delivery, Proteins and peptides, Polymeric self-assemblies, Nano-complexes, Enzymatic degradation |
| Status: | Published |
| Refereed: | Yes |
| Glasgow Author(s) Enlighten ID: | Tetley, Dr Laurence |
| Authors: | Thompson, C.J., Tetley, L., Uchegbu, I.F., and Cheng, W.P. |
| Subjects: | Q Science > QP Physiology Q Science > QR Microbiology > QR180 Immunology |
| College/School: | College of Medical Veterinary and Life Sciences > School of Life Sciences |
| Journal Name: | International Journal of Pharmaceutics |
| ISSN: | 0378-5173 |
| Published Online: | 16 April 2009 |
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