infocus #17 March 2010 PLGA Microspheres

McCarthy explains how he prepares PLGA microspheres for imaging and compares various imaging techniques.

DOI: 10.22443/rms.inf.1.53

PLGA (polylactic-co-glycolic acid) is a biodegradable and biocompatible copolymer that is widely used in the pharmaceutical industry as a drug delivery vehicle.

As a microscopist, I am frequently asked to image microspheres/microparticles (and nanospheres/nanoparticles) that aare formulated from PLGS using the Scanning Electron Microscope (SEM), for both size distribution and shape. Most researchers are concerned with obtaining a formulation that will yield a uniform particle size, which is within a desired range and that SEM images also match data from the mean particle analyser that uses light scattering techniques. In addition, sometimes it is necessary to image fractured particles to determine if they are solid or hollow.

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Author

David McCarthy

Experimental Officer, Electron Microscopy Unit, The School of Pharmacy, University of London, UK

David set-up the EM unit in The School of Pharmacy in January 1977 and has imaged a wide variety of samples using the TEM, SEM and optical microscopes, including cell cultures, crystals and most forms of drug delivery vehicles, from liposome’s and polymers to carbon nanotubes. The unit currently has a FEI CM120 Biotwin TEM with an AMT digital camera, a FEI Quanta FEG ESEM and a Nikon Microphot optical microscope. David has been a microscopist for 37 years and has won many awards for images, including 10 ‘Images of Excellence’ from the Wellcome Trust (2007/8/9), First prize for the UK Micro and Nanotechnology Network Image Competition (2006), Overall winner in the ’Visions of Science’ competition in both 2004 and 2005 and 5 prizes from the RMS International Micrograph Competition (including two Firsts). David is also honorary secretary of the Society of Electron Microscope Technology (SEMT) from 2000 and since 2005 sits on the RMS EM section committee.