(176x) Polymeric Particle Based Endotoxin Removal from Protein Solutions

Contamination of parenteral biomolecules and pharmaceutical products with endotoxins while extraction is one of the major shortcoming associated with the production of several biomolecules. Although there exists several techniques for removing endotoxins from biological and protein solutions, but there doesn’t exist a generalized method on how endotoxins removal can be carried out in an efficient and economical way and is therefore still one of the most sought-after issue with no satisfactory solution yet. In the past, different adsorbents have been investigated to remove endotoxins from protein and biological solutions. The most widely used interactions for endotoxins removal have been hydrophobic and electrostatic. In this work, the effectiveness of polymeric poly-ε-caprolactone (PCL) nanoparticles (NPs) (𝑑𝑃=780±285 𝑛m) synthesized using solvent evaporation technique in removing endotoxins from two model protein solutions using its hydrophobic interaction with endotoxins was evaluated. The PCL NPs removed ~93% LPS from protein solutions in water and the endotoxins removal efficacy increased to a higher level (~96%) when protein solutions were prepared using phosphate buffered saline (PBS; 150 mM NaCl), reflecting strengthening of endotoxins binding interactions with PCL in presence of kosmotropic salts which promote hydrophobic interaction. Protein recovery over 90 % was observed for the protein samples in water and PBS. Proteins and endotoxins were quantified using the BCA and BODIPY assay technique.