PEGylation
PEGylation technology refers to the process of attaching Polyethylene Glycol (PEG), a non-toxic and non-immunogenic polymer, to a molecule, drug, or protein. As a professional biotech company, we offer PEGylation services to help optimize the pharmaceutical properties of your molecules and maximize their potential uses in therapeutic applications.
What is PEG?
The chemical structure of Polyethylene Glycol (PEG) is HO-(CH2CH2)n-OH, which is a general term for ethylene glycol polymers with relative molecular mass between 200-8000 and above. PEG has precise molecular weight and is colorless, tasteless, non-toxic, non-immunogenic, biocompatible, highly soluble in water, high purity and low dispersibility.
The process of PEGylation increases the molecule's stability, circulating half-life, and solubility while reducing its immunogenicity. As a result, it enhances the therapeutic effects of drugs and improves their safety profiles. This technology can be applied to several molecules such as peptides, proteins, antibody fragments, liposomes, and nanoparticles.
PEGylated nanoparticles are often used in the field of biomedicine, particularly in drug delivery systems. The properties of PEG ensure that the nanoparticles have a prolonged circulation time in the body and a reduced immune response. This allows for a more effective delivery of therapeutic agents to target cells or tissues. This technique is widely used in pharmaceutical industry to enhance the therapeutic profile of drugs, especially those used in cancer treatment and other serious diseases.
Fig. 1 PEG-prodrug. (Mishra, P., 2016)
Types of PEGylation Molecules
Proteins: Protein PEGylation can prolong the circulating half-life, reduce immunogenicity, and improve the stability of proteins.
Peptides: Peptide PEGylation can significantly enhance their stability, half-life, and bioavailability.
Antibody Fragments: PEGylation can increase the size of antibody fragments and prolong their circulation time in the body.
Liposomes: PEGylation of liposomes can reduce their recognition by the immune system, thereby increasing their circulation time and improving the efficiency of drug delivery.
Nucleic Acids: PEGylation helps protect nucleic acids from nuclease degradation and extend their circulation half-life.
Small Molecule Drugs: PEGylation of small molecule drugs can enhance their solubility, stability, and half-life, reduce toxicity and side effects, and improve therapeutic efficacy.
Applications of PEGylation
Drug Delivery: PEGylation can be utilized to improve the pharmacokinetics of drugs. By attaching a PEG molecule to a therapeutic compound, its circulation time in the blood can be prolonged, reducing the frequency of administration and improving patient compliance. PEGylated drugs demonstrate decreased immunogenicity and antigenicity, increased solubility, and enhanced stability.
Diagnostics: PEGylation is used to reduce non-specific binding in diagnostic tests. Non-specific binding can lead to false-positive results and by PEGylating the diagnostic biomarkers, the accuracy of test results can be improved.
Biotechnology: PEGylation is also used in various biotechnology applications such as protein and peptide stabilization. By attaching PEG molecules to proteins and peptides, their stability, solubility, and resistance to proteolytic degradation can be increased.
Our company has expertise in PEGylation technology and we assure to provide robust, efficient and reliable solutions tailored to your specific needs.
Our PEGylation Services
As a professional biopharmaceutical company, we can provide the following services regarding PEGylation technology:
Customized PEGylation Service: According to customer needs, we can develop specific PEGylation strategies to optimize drugs, improve drug stability, extend half-life, increase solubility, reduce immunogenicity, etc.
PEGylated Drug Development: We provide a full range of PEGylated drug development services, including early-stage scientific research, drug design, and late-stage clinical trial support.
Production and Purification of PEGylated Proteins/Peptides/Drugs: Provides PEGylation services for small-scale production and can carry out optimized purification processes to ensure the stability and efficacy of drugs.
PEGylation Research and Development: We have a professional R&D team to conduct various application research on PEGylation, including the development of new drugs, the improvement of biomedical equipment, etc.
PEGylation Technology Consulting: We provide professional PEGylation technology consulting services and answer any questions customers have about PEGylation technology.
PEGylation Technology Training: Provide PEGylation technology training services to R&D personnel.
Quality Control and Stability Studies: Our quality control team will conduct strict quality tests on PEGylated products to ensure their properties and activity. We will also do stability studies, including physical stability, chemical stability and biological stability. Research.
Technology Transfer and Licensing: Based on customer needs, we can provide technology transfer or licensing services for PEGylation technology.
Our PEGylation Products
Our Advantages
Highly Experienced Team: We have extensive experience in custom PEGylation and comprehensive expertise in chemical and biological preparations.
Various Applications: Our PEGylation services can be applied to a wide range of products such as proteins, peptides, antibodies, and small molecules, making us a versatile partner in the biopharmaceutical industry.
Customized Services: We offer custom synthesis services and modify the properties of molecules according to customer-specific requirements.
Speedy Delivery: Our proven processes and efficient workflow ensure rapid turnaround times without sacrificing quality or accuracy.
Quality Assurance: We adhere to stringent quality regulations and standards to ensure utmost product consistency, potency, and purity.
Intellectual Property Rights: We fully respect our clients' intellectual property, maintaining strict confidentiality and offering transparent, clear communication throughout the entirety of each project.
Affordable Pricing: Despite our high-quality services, we offer competitive pricing models that prove cost-effective for our customers.
Excellent Customer Service: We pride ourselves on our exceptional customer service, where we maintain constant communication and provide progress updates throughout each project.
Trusted Partnership: Many top-tier biopharmaceutical companies around the world have chosen to partner with us, reflecting our reliability and professional expertise in PEGylation technology.
General Workflow for PEGylation
PEGylation: The conjugation of PEG to the molecule using various chemistries.
Purification: Purification steps are employed to remove unreacted PEG and other contaminants.
Analysis: The PEGylated product undergoes rigorous quality control testing to assess its stability, purity, and activity. Analytical methods such as size exclusion chromatography (SEC), dynamic light scattering (DLS), and mass spectrometry are typically used for these analyses.
PEGylation Protocol
Materials Required:
Drug or Protein
Polyethylene glycol (PEG) reagent
Suitable buffer solution
Dialysis membrane
Spectrophotometer or HPLC system for analysis.
Protocol:
- Dissolve the protein or drug in a suitable buffer solution.
- Add the PEG reagent to the solution. The molar ratio of PEG to protein/drug will be dependent on the specific application.
- Allow the reaction to occur at a suitable temperature for a specific time duration. This typically involves incubating the solution at a temperature of 4-37 ˚C for a period of several hours to days.
- Stop the reaction by adding a stop solution or by quickly cooling the samples.
- Remove the non-reacted PEG by dialysis or size-exclusion chromatography. This step is critical to purify the protein/drug from any unbound PEG.
- Analyse the PEGylated protein/drug using a spectrophotometer or HPLC system to confirm successful PEGylation and measure the degree of modification.
- Storage conditions of PEGylated products will vary based on the specific protein or drug used, but generally they should be stored in a cool, dry place.
Disclaimer:
This protocol is a broad overview and may not be suitable for all PEGylation applications. Always consult the literature or a specialist before performing any new protocols or techniques.
Case Study
Case Study 1
The technique of passive targeting drug delivery relies primarily on the concentration gradient produced between intracellular and extracellular spaces due to the drug's high concentration in the tumor vicinity. PEG conjugates take advantage of the enhanced permeation and retention (EPR) effect triggered by tumors to accumulate in the tumor vessels' pathological environment, facilitated by leaky vasculature and deficient lymphatic drainage. However, this effect is size-dependent and cannot be examined with low molecular weight drugs that can easily extravasate and cause systemic toxicity. The process of PEGylation enhances the size, molecular mass, solubility, and serum stability of drugs. Consequently, PEGylation is highly recognized as one of the most effective methods for passive targeting of anticancer treatments for these significant reasons.
Fig. 2 A schematic illustration of passive targeting with acid-sensitive PEG-prodrugs that cleave in the extracellular space. (Mishra, P., 2016)
Case Study 2
The early stages of creating PEG-protein conjugates relied on reactions with limited chemoselectivity which non-specifically altered the surface nucleophiles of proteins. However, advancements in bioorthogonal reactions and the utilization of unnatural amino acids in proteins have allowed for improved control over PEGylation site and degree. Some techniques include reductive alkylation for N-terminal a-amino groups, targeting Cys residues with PEG maleimides, vinyl sulfones, disulfides, or iodoacetamides, or converting Cys side-chains into dehydroalanine for modification with PEG thiol. Despite the possibility of diastereomeric mixtures, the significance of this stereochemical inconsistency hasn't been experimentally explored. Additionally, unnatural amino acids containing orthogonally reactive functional groups can be integrated into the proteins themselves and then selectively modified with corresponding PEG reagents. This produces PEG-protein conjugates with precisely-positioned PEGs, which opens up new possibilities for protein-based therapeutics.
Fig.3 Examples of natural and unnatural amino acids used in protein-PEG conjugation. (Paul, B.L., 2016)
FAQ
1. What is PEGylation?
PEGylation is the process of attaching the Polyethylene Glycol (PEG) polymer chains to another molecule, typically a drug or therapeutic protein, which can improve the safety and efficacy of therapeutic agents.
2. What are the benefits of PEGylation?
PEGylation can enhance the therapeutic properties of drugs by increasing their stability, solubility and half-life, improving their pharmacokinetics, and reducing immunogenicity and toxicity.
3. How does PEGylation improve drug delivery?
By increasing drug solubility, stability and reducing the clearance rate, PEGylation prolongs the circulation time of the drugs in the body, leading to a longer duration of action and better drug delivery to the targeted tissues or cells.
4. How does PEGylation reduce immunogenicity and antigenicity?
As a stealth polymer, PEG can effectively shield the drug molecule from the immune system, reducing the immunogenicity and antigenicity, which minimizes the risk of immune responses and side effects.
5. Does PEGylation affect the biological activity of drugs?
PEGylation may lead to the loss of biological activity of some proteins, but with the optimal design of PEGylation strategy, this negative impact can be minimized or offset by the improved pharmacokinetic properties.
6. Can you provide site-specific PEGylation?
Yes, we offer site-specific PEGylation strategies to control the PEGylation site and ratio, aiming to maximize the therapeutic effects and minimize potential side effects.
7. What types of molecules can be PEGylated?
A wide range of molecules can be PEGylated, including small molecule drugs, peptides, proteins, antibodies, oligonucleotides, and other therapeutic agents.
8. How do you ensure the quality and consistency of PEGylation?
We have established strict quality control systems, including the analysis of PEGylation degree, homogeneity, and bioactivity, to ensure the high quality and batch-to-batch consistency of PEGylated products.
9. What services do you provide related to PEGylation?
We provide comprehensive PEGylation services, from PEGylation strategy design, custom synthesis of PEGylated products, to analytical services such as PEGylation degree analysis and bioactivity test.
References
- Mishra, P., et al., Pegylation in anti-cancer therapy: an overview. Asian Journal of Pharmaceutical Sciences. 2016, 11: 337-348.
- Paul, B.L., et al., How pegylation influences protein conformational stability. Current Opinion in Chemical Biology. 2016, 34: 88-94.