Introduction Polymeric porous microspheres are promising for drug delivery and cancer therapeutics.

Polymeric material benefits: • Biocompatibility • Degradability • Excellent thermal and mechanical properties • Eliminated by kidney filtration and bioassimilation • Can be made from from renewable resources1,2

Porous Microspheres: • Less polymer to be eliminated from the body • Can be filled with cells and therapeutics • Control drug delivery • Cell internalization and phagocytosis3,4

2 to 250µm

4nm to 25µm <100nm

6 to 200nm

• Introduction

Results and Discussion

Stirrer time

Rate of droplets

Aqueous phase concentration

pH

Increased energy input to system

• Introduction

66.92+ 19.2µm 2.02 + 1.04µm

29.52+ 1.94µm 1.63 + 0.05µm

16.64+ 6.87µm 1.40 + 0.20µm

0.20 + 0.025µm

44.50+ 23.44µm 1.63 + 0.05µm

55.35+ 21.1µm 3.84 + 1.02µm

Conclusions • The sphericity , porosity, surface morphology and size of

spheres can be controlled by varying the parameters • Hydrolysis can be applied post production to enable

interconnected and wide-open porous structures • These microspheres have a variety of applications, including –

drug carriers, enzyme transplantation, gene therapy and as contrast agents in diagnostics.

Delivery site and target size 5,6,7:

Porous Polymer Microspheres:

Controlling shape, size and porosity

for controlled drug delivery

Ana Letícia Braz1, Derek Irvine and Ifty Ahmed1 1Advanced Materials Research Group, Healthcare Technologies, University of Nottingham, Nottingham, UK.; Tel: +44 (0) 115 7484675

E-mail: emxalb@nottingham.ac.uk and ifty.ahmed@nottingham.ac.uk

• Introduction

References 1. Almeida S A et al., J.Poly Test., 31, 267-275, 2012. 2. Vert M et al., Euro. Poly. J., 68, 516-525, 2015. 3. Leong K W et al., J.Contro.Rel., 53, 183-193, 1998. 4. Kim M R et al., Macrom. J., 34, 406-410, 2013. 5. Bertrand N et al., J.Contro.Rel.,161, 152-163, 2012. 6. Broichsitter M B et al., J.Contro.Rel., 161, 214-224, 2012. 7. Yu Y et al., Biom.J., 35, 3467-3479, 2014.

• Introduction Aim and Objectives

In this work emulsion based techniques were used with varying surfactant concentration (polyvinyl alcohol) and stirring conditions to produce porous microspheres with varying porosity ranges.

Methodology

• Introduction Acknowledgements

The authors would like to thank the University of Nottingham Faculty of Engineering Dean of Engineering Scholarship and Capes for International Excellence in Research for funding this project.

50 to 100nm

Organic solvents (dichloromethane solvent for PLA) and non-solvent cyclohexane are mixed with water in presence of surfactant (PVA) and stirred to create an emulsion

Methodology