Novel copolymers as mucoadhesives for drug delivery systems by luckboy


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									Novel copolymers as mucoadhesives for drug delivery systems
CfAM MicroNote 107 The surfaces of the eye, nose, mouth, respiratory tract, cervix and gastrointestinal tract are covered in mucus which is essentially a fully hydrated viscoelastic gel. The mucus protects the epithelial cells from physical and chemical harm and provides lubrication and wetting to the underlying tissue. Delivery of drugs to these regions requires careful design and there is much current interest in the design of mucoadhesive materials. Work at the University of Reading led by Dr Vitaliy Khutoryanskiy in collaboration with scientists at Kazakh National University is focusing on the use of novel cationic copolymers for this purpose.

The image to the left shows a transmission electron micrograph of an aqueous dispersion of mucin particles. The dark regions are the mucin particles. There is a polydisperse distribution of mucin particles with a bimodal spread. It is quite likely that the larger particles are aggregates of the smaller ones which average at 130nm while the large particles are of the order of 500nm.

This image shows a sample of the mucin dispersed in the novel cationic copolymers based on [2-(methacryloyloxy) ethyl]trimethylammonium chloride in the ratio 8:1. The image clearly shows the greater population of the smaller particles. The inhibition of the mucin aggregation is thought to be due to the interaction of the copolymer on the surface of the mucin particle. Microscopists – Nataliya Fefelova, Vitaliy Khutoryanskiy and Peter Harris These two images were obtained using a Philips CM20 transmission electron microscope in the Centre for Advanced Microscopy. For sample preparation the cooper grids were brought in 30 sec contact with aqueous dispersions of pure mucin and mucin mixed with copolymers, and then they were treated with 2 % of phosphotungstic acid for 10 sec and finally dried off with a filter paper. These images form part of a scientific paper Fefelova, N.A., Nurkeeva, Z.S., Mun, G.A., Khutoryanskiy, V.V., Mucoadhesive interactions of amphiphilic cationic copolymers based on [2-(methacryloyloxy)ethyl]trimethylammonium chloride, International Journal of Pharmaceutics (2007), doi:10.1016/j.ijpharm.2007.02.019 The Centre for Advanced Microscopy provides cutting edge microscopy services and solutions for the life and physical sciences CfAM, University of Reading, Whiteknights, Reading RG6 6AF UK 0118 378 6118 Fax 0118 378 4606 Email

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