PEGylation of Nanocarriers

Nanocarriers, such as micelles, liposomes, polymeric nanoparticles and inorganic nanoparticles are promising tools for controlled drug delivery or imaging in cancer therapy and many other applications. Up to date, a number of nanocarriers have been approved for clinical treatment of a variety of therapeutics. Our enormous knowledge, advanced skills and excellent capabilities will provide you with the most optimized synthesis route, the PEGylated products with the best quality, and offer you a value-added service to meet development needs.

Fig. 1. Schematic illustration of the most commonly used drug nanocarriers (Angew Chem Int Ed Engl. 2022, 61(3): e202107960).

What Are Nanocarriers?

Nanocarriers (10-100 nm) are drug delivery systems that utilize nanoparticles to transport and release therapeutic agents to specific target sites in the body. The potential uses and efficacy of various nanodrug carriers for anticancer drugs are much higher than those of ordinary nanodrug carriers. Nanocarriers offer several advantages over traditional drug delivery systems, such as extended plasma half-life, improved biodistribution, and targeted delivery of drugs to the tumor microenvironment through the endothelium. These nanocarrier-based drug delivery systems are used to combat various types of cancerous tumors containing tissue. Nanocarriers come in various forms, such as liposomes, polymeric nanoparticles, micelles, dendrimers, and solid lipid nanoparticles, each with its own unique properties and advantages.

Polyethylene Glycol Mechanism of Action

All nanoparticles (NPs) contain at least two basic spatial components: core and corona, which interact with the environment or solvent. Core/multi-shell systems add further complexity when in the core-shell configuration, for example, all core/multi-shell systems still have regions at the NP-solvent interface. PEG chains alter this interfacial layer and increase cycle time. Circulating half-life (t ½ ) describes the blood pool residence time and is the time during which the nanoparticle concentration in the circulation remains above 50% of the injected dose, similar to the half-life of a drug. Nanoparticle efficacy requires a sufficient t½ not only to reach the target but also to remain in the affected area (at a concentration sufficiently above background tissue) long enough to allow for image capture or drug delivery. The reticuloendothelial system (RES) prevents accumulation at specific sites because it removes nanoparticles from circulation, thereby acting as competitors for the intended target site. Additionally, nanoparticles must be cleared from non-target areas to produce imaging contrast or dose efficiency.

PEGylation Services for Nanocarrier

One of the major benefits of using nanocarriers for drug delivery is their ability to improve the solubility and stability of poorly soluble drugs. Nanocarriers can also be designed to target specific cells or tissues in the body, allowing for more precise and effective drug delivery. Additionally, nanocarriers can be used to deliver multiple drugs simultaneously, either in combination or sequential treatments. Nanocarriers can deliver synergistic combinations of drugs to target sites by encapsulating different drugs in separate compartments within the nanoparticle or conjugating them to the surface of the nanoparticle.

At BOC Sciences, our PEGylation services for nanocarriers are designed to help our customers optimize the performance of their drug delivery systems. Our expert team has extensive experience in PEGylation chemistry and can provide customized solutions to meet the specific requirements of each project. We offer comprehensive services including PEGylation of nanoparticles, liposomes, micelles and other nanocarriers, as well as characterization and analysis of PEGylated products.

PEGylation of Polymeric Nanoparticles

Biodegradable polymeric nanoparticles have many advantages for drug delivery, such as controlled release and targeting. However, after intravenous administration of polymeric nanoparticles, they will be cleared by the endothelial reticulum system within a few seconds or minutes. In order to overcome this shortcoming, hydrophilic PEG is introduced to modify the polymer. The introduction of PEG will not only affect the biodegradation behavior of nanoparticles, but also affect the release and distribution of drugs in the body. Polymeric nanoparticles are usually PEGylated by (1) physical surface coverage with PEG or PEG derivatives, (2) preparation of nanoparticles with PEG block co-polymers and (3) grafting PEG onto the nanoparticles surface.

Fig. 2. Types of polymeric nanoparticles (Pharmaceutics. 2022, 14(8): 1566).

PEGylation of Inorganic Nanoparticles

Inorganic nanoparticles made of calcium phosphate, gold, silica and iron oxide are preferred for drug delivery due to ease of preparation and uniform size and amenability for surface functionalization. However, these are less stable and could be toxic in biological systems. Therefore, in order to improve the biological stability and biocompatibility, surface modification has been carried out with PEG.

Fig. 3. PEG prevents uptake by the reticuloendothelial system (Nanomedicine. 2011, 6(4): 715-728).

PEGylation of Liposomes

Liposome is an ideal drug delivery carrier. It has targeted properties, longer blood retention time and higher organ distribution selectivity, can improve the efficacy of drugs and reduce toxic side effects. Ordinary liposomes have the disadvantage of being easily cleared from the systemic circulation by liver and spleen macrophages. In this case, PEGylation can solve the above shortcomings, making liposomes stay in the blood for a longer time and increasing the passive targeting function of drugs. Moreover, it is simple to prepare PEG-phospholipid derivatives in advance, which has become the current research focus of PEGylation technique.

Fig. 4. Schematic diagram of PEGylated liposome.

PEGylation of Micelles

Micelles are frequently preferred choice for anticancer drug delivery. Preparation of PEGylated micelles mostly utilizes PEGylated polymers or lipids through synthetic approaches. Block copolymer micelles with PEG coronas have emerged as systems with great potential in drug delivery, as they combine biocompatibility with the synthetic versatility of PEG. A variety of activated PEGs can be used exploited for these systems, such as block copolymer structures, providing control over the type and stability of covalent.

Nanocarrier Characterization Services

Nanocarriers offer several advantages over traditional drug therapies because their size, charge, surface properties, and targeting moieties are more easily tailored to modulate their uptake, biodistribution, targeting, and elimination. They can be administered by many different routes, such as parenteral, nasal, topical or oral routes. Owing to the above-mentioned advantages, there is an increasing need to develop nanocarriers with broad properties targeting various diseases. Based on this, BOC Sciences offers PEGylated nanocarrier characterization services covering a comprehensive range of techniques for evaluating and optimizing the properties of nanocarriers for various applications in drug delivery.

Why Choose BOC Sciences?

• Customizing the PEGylation process to meet the requirements of different nanoparticles and therapeutic agents
• Precise tuning of PEG chain length, density and orientation on nanoparticle surfaces
• Improving the pharmacokinetic properties of nanocarriers and the therapeutic agents they carry
• Provides a seamless transition from laboratory scale to pilot scale production
• Experienced project managers to oversee the entire development process
• Committed to providing cost-effective solutions without compromising on quality
• Provide comprehensive reports outlining product synthesis, characterization and performance

PEGylation Service Process

References

1. Tiwari, N. et al. Nanocarriers for Skin Applications: Where Do We Stand? Angew Chem Int Ed Engl. 2022, 61(3): e202107960.
2. Sabit, H. et al. Nanocarriers: A Reliable Tool for the Delivery of Anticancer Drugs. Pharmaceutics. 2022, 14(8): 1566.
3. Jokerst, J.V. et al. Nanoparticle PEGylation for imaging and therapy. Nanomedicine. 2011, 6(4): 715-728.