Conventionally used in vitro cancer models such as cancer cells cultured as a monolayer in a petridish, are not representative of the in vivo environment. Cancer spheroids (CS) are now being studied as an alternative to these monolayers, for more accurate early screening of promising drugs. Systematic generation of CS in biologically simulated polymeric scaffolds represent various characteristics of solid tumors such as tissue architecture and cell-cell or cell-extracellular matrix interactions  formed in humans and hence can be used as an in vitro model for fundamental investigations in cancer biology including studying various variables that affect tumor progression. These polymeric scaffold-based CS can be used for high throughput drug analysis, which is impracticable with in vivo animal studies or human samples. With this background, the present research focuses on the formulation of porous PLGA microspheres (PPMS) using a novel alginate microspheres (AMS) porogen which can subsequently be used to develop three dimensional (3D) cancer spheroids with uniform size and morphology.
The AMS porogen was developed by water-in-oil emulsion technique as described by Zhu et al.  with minor modification and non-porous PLGA MS (PLGAMS) were prepared using a single emulsion (oil-in-water) solvent evaporation technique . PPMS was developed by double emulsion solvent evaporation technique using AMS as the porogen. The porogen was added to PLGA to form the primary emulsion, which was then emulsified in poly vinyl alcohol solution. Formulated microspheres were then treated with ethylenediaminetetraacetic acid (EDTA) to digest AMS followed by centrifugation and washing with distilled water to get purified PPMS. AMS, PLGAMS and PPMS were finally evaluated for their size and morphology using brightfield microscopy and scanning electron microscopy (SEM).
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Jyothi Menon– Assistant Professor, Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island