Polyoxazoline: A Potent Alternative to PEG-based Formulations of Hydrophobic Drugs

3/11/2019 11:45 - 12:20

  • Chemistry of Polyoxazolines (POx)
  • POx as a double amphiphile
  • Toxicity, immunogenicity and endocytosis of POx
  • POx conjugates
  • POx for the formulation of strongly hydrophobic drugs
  • POx nanoformulations: Preparation, stability, profile
  • Preclinical evaluation of POx nanoformulations vs. commercial formulations
  • Perspective

Polyethylenglycol (PEG) is still the gold standard for many polymer therapeutics (drug-polymer or protein-polymer conjugates) and PEG-containing polymer amphiphiles are widely used for the solubilization/formulation of hydrophobic drugs. This is because of early reports of the “stealth-effect”, advantageous biocompatibility and low immunogenicity of PEG. However, the widespread use of PEG and PEG-derivatives not only in therapeutics but in cosmetics, body care products, food additives and countless technological applications results in a constant exposure of humans to PEG. A constant growing number of reports evidence that the immune system can produce antibodies that specifically bind to PEG and an “accelerated blood clearance” (ABC) leads to failure of PEG-based therapeutics. Thus, there is an urgent need for alternative polymers with a similar or even better pharmacological profile. One of those is polyoxazoline (POx) for which the same “stealth-effect” was early reported. This talk will briefly outline the chemistry, toxicity and immunogenicity of POx and then focus on the use of amphiphilic POx as an exipient for the nanoformulation of strongly hydrophilic drugs. Besides unparalleled drug loading capacities of POx-based nanoformulations, long-term stability and facile formulation procedure, results of the preclinical evaluation of POx-based nanformulations for the treatment of cancer will be presented.