The term “dPEG®” is Quanta BioDesign’s trademarked acronym for “discrete polyethylene glycol” or “discrete PEG”. The “discrete” portion of the dPEG® trademark indicates single molecular weight PEG technology. Like traditional PEGs, our products contain an amphiphilic backbone of repeating ethylene oxide units. However, traditional PEGs are not single compounds. Quanta BioDesign invented and manufactures these monodisperse PEG products using our proprietary synthetic and purification processes.
What is PEGylation?
PEGylation is the process adding polyethylene glycol (PEG) to a molecule or surface, often through covalent modification of the targeted molecule or surface. Molecules and surfaces that have been modified by PEGylation are called PEGylated. Any surface containing appropriate functional groups can be PEGylated. Gold, silver, iron, and silica are examples of surfaces that are often PEGylated for use in diagnostic, therapeutic, or theranostic applications. The list of molecules that are PEGylated is enormously long and continually expanding. Examples of the types of molecules that are PEGylated include small molecule therapeutic drugs, peptides, proteins, the carbohydrate coats of glycoproteins, oligonucleotides, and lipids.
The benefits of PEGylation include increased water solubility, increased hydrodynamic volume, decreased immunogenicity, and extended circulation in vivo in the bloodstream due to reduced renal clearance. In addition to reducing renal clearance, PEGylation also often modifies the biodistribution and pharmacokinetics of therapeutic, theranostic, and diagnostic molecules.
Specifically, traditional PEG products are prepared by polymerization processes. Any polymerized PEG product is a Poisson distribution of chain lengths and molecular weights., This distribution was formerly known as the polydispersity index (PDI), but is now known as the dispersity index or simply dispersity (indicated by the symbol “Đ”). The reported molecular weight is an average molecular weight, and Đ (or PDI) gives an indication of the range of molecular weights in the sample. Disperse samples have Đ > 1 and are a heterogeneous mixture of sizes and molecular weights. High M.W. (>50 kDa) traditional PEG has Đ up to 1.1. Lower M.W. traditional PEG has Đ in the range of 1.01 – 1.05. These numbers represent broad distributions of molecular weights.,,
dPEG® Products Are Different
Our dPEG® products are quite different from traditional PEGs, because of our proprietary, patent-protected processes. Each dPEG® product represents a single compound with a unique, specific, single molecular weight (MW). See Figure 1.