Protein Formulation
As PLGA is the only approved synthetic matrix for implantable, resorbable depots, it has been widely applied in the development of sustained release protein therapeutics. However, it is widely understood that this material has several disadvantages when concerned with the microencapsulation of sensitive biomolecules. Its hydrolysis liberates carboxylic acid residues, which remain trapped within microspheres and gradually decrease the internal pH. Frequently, this causes proteins to unfold and form insoluble aggregates, which drastically reduces the potential for steady drug release and may also illicit an immune response in vivo.
Further, the combination of water soluble protein and water insoluble polymer usually necessitates the use of immiscible phases and surfactants to create an emulsion. It is commonly known that proteins containing hydrophilic and hydrophobic domains are disposed to unfold at water-solvent interfaces.
Q Chip is researching a proprietary microfluidics-based method for combining and controlling therapeutic proteins and PLGA solution, which does not involve rapidly sheared bi- or tri-phasic emulsions. In collaboration with Artes Biotechnology GmbH we are working around the conventional limits of microencapsulation technology to stabilise Interferon alpha-2a in injectable PLGA microspheres to provide sustained release over two to four weeks.
