Encapsulation of Uncharged Water-Insoluble Organic Substance in Polymeric Membrane Capsules via Layer-by-Layer Approach

Manna, Uttam and Patil, Satish (2008) Encapsulation of Uncharged Water-Insoluble Organic Substance in Polymeric Membrane Capsules via Layer-by-Layer Approach. In: Journal of Physical Chemistry B, 112 (42). pp. 13258-13262.

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Abstract

We report a general and versatile method for the encapsulation of electrically uncharged organic substance in polymeric capsules by using a layer-by-layer (LbL) approach. Electrical charge was induced on the surface of pyrene (uncharged organic substance) with an amphiphilic surfactant (sodium dodecyl sulfate, SDS) by micellar solubilization. The SDS micellar solution of pyrene in water was then deposited on a flat substrate as well as colloidal particles with chitosan as an oppositely charged polyelectrolyte. Pyrene was used as a model drug because it displayed intrinsic fluorescence that allowed us to monitor LbL growth by fluorescence and under confocal laser scanning microscopy (CLSM). To examine the proof of concept, multilayers were coated on the planar support by the LbL method. UV-vis spectroscopy showed regular growth of each layer deposited. Thin film formation was evidenced by scanning electron microscopy. The LbL method was extended to particles where fluorescence spectroscopy revealed LbL growth and transmission electron microscopy (TEM) provided evidence of particle coating. The quantification of dye in each deposited layer further proved LbL growth. The removal of sacrificial core provided thin capsules. The capsules were characterized by TEM and CLSM. The capsules showed potential as a drug delivery system, which is suggested by the slow release of entrapped dye by concentration-dependent diffusion in isotonic saline solution. The kinetics of desorption of pyrene from this thin film was modeled by a pseudo-second-order model.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry B
Publisher:	American Chemical Society
Additional Information:	Copyright of this article belongs to American Chemical Society.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	19 May 2009 05:03
Last Modified:	19 Sep 2010 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/16761

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