PLGA-PEG-PLGA
PLGA Molecular Weight: 1,000-50,000 Da
PEG Molecular Weight: 1000, 1500, 2000, 3000, 4000
Ratio(LA:GA): 50:50, 75:25
Minimal order quantity: 10 gram
PLGA-PEG-PLGA
PLGA Molecular Weight: 1,000-50,000 Da
PEG Molecular Weight: 1000, 1500, 2000, 3000, 4000
Ratio(LA:GA): 50:50, 75:25
Minimal order quantity: 10 gram
PLGA-PEG-PLGA is a state-of-the-art, biodegradable ABA triblock copolymer celebrated for its intelligent thermosensitive properties. This polymer is uniquely designed to undergo a reversible sol-gel transition in response to temperature changes. At lower temperatures (e.g., 4-20°C), it exists as a free-flowing, low-viscosity aqueous solution, making it easy to handle and mix with therapeutic agents. As the temperature rises to physiological levels (≈37°C), the polymer chains self-assemble into a three-dimensional hydrogel network. This in-situ gelling capability makes it an exceptional material for creating injectable, sustained-release drug depots.
To meet the precise demands of your research, we offer a diverse portfolio of PLGA-PEG-PLGA polymers. You can customize the material’s properties by selecting from a range of molecular weights for the central hydrophilic PEG block and the terminal hydrophobic PLGA blocks. Furthermore, the degradation rate and drug release kinetics can be precisely engineered by specifying the lactide-to-glycolide (L:G) ratio within the PLGA segments. This high degree of tunability allows you to control the exact gelling temperature, mechanical strength, and erosion profile of the resulting hydrogel.
The primary application for this remarkable polymer is in the development of injectable drug delivery systems for localized, long-term therapies. It is widely used to create sustained-release depots for proteins, peptides, and small molecule drugs in fields such as oncology, pain management, and ophthalmology. Its unique properties are also being explored for advanced applications in tissue engineering, where it can be used as an injectable scaffold that solidifies upon entering the body, and in 3D bioprinting as a component of sophisticated, temperature-responsive bioinks.
FAQ
Most frequent questions and answers
The mechanism is driven by temperature-dependent changes in polymer-water interactions. At low temperatures, the polymer chains are well-hydrated and exist as individual molecules or small aggregates, resulting in a low-viscosity solution (a “sol”). As the temperature increases towards body temperature (≈37°C), the hydrophobic PLGA blocks begin to dehydrate and associate with each other, forming a network of micelles that creates a viscous, three-dimensional hydrogel (the “gel” state). This transition temperature is known as the Lower Critical Solution Temperature (LCST).
The gelling behavior is concentration-dependent. A gel will only form above a certain threshold known as the Critical Gelation Concentration (CGC). For most PLGA-PEG-PLGA systems, this is typically in the range of 15% to 30% by weight in an aqueous buffer (like PBS). We recommend starting your experiments with a concentration of around 20 wt% and adjusting as needed for your specific polymer and application.
The gelling temperature is a highly tunable property based on the polymer’s architecture:
PLGA Block Length: Increasing the length (molecular weight) of the hydrophobic PLGA blocks will decrease the gelling temperature.
PEG Block Length: Increasing the length of the central hydrophilic PEG block will increase the gelling temperature.
L:G Ratio: A higher lactide content (e.g., 75:25 vs 50:50) makes the PLGA block more hydrophobic, which will also decrease the gelling temperature.
By selecting a polymer with the right combination of these parameters from our catalog, you can achieve a gelling temperature precisely tailored to your needs.
The process is remarkably simple. You first dissolve or suspend your therapeutic agent (drug, protein, etc.) into the cold aqueous polymer solution while it is still in its low-viscosity liquid state. Gentle mixing is usually sufficient to ensure a homogenous distribution. Once injected, the entire system will gel together, physically entrapping the drug within the hydrogel matrix for sustained release.
The primary advantages are ease of administration and patient comfort. Unlike microspheres that require complex fabrication and resuspension, this system is a simple aqueous solution. It can be easily injected through a standard needle. This is less invasive than surgical implantation and provides better conformity to irregular tissue sites compared to solid implants.
Because the polymer is sensitive to heat and hydrolytic degradation, you cannot use an autoclave. The recommended method for sterilization is sterile filtration. Prepare your drug-polymer solution in an aseptic environment and pass it through a 0.22 µm syringe filter while the solution is still cold and has low viscosity.
The hydrogel degrades via hydrolysis of the ester bonds in the PLGA blocks, similar to standard PLGA. The degradation byproducts are lactic acid and glycolic acid, which are naturally metabolized by the body. The central PEG block is water-soluble and is cleared through the kidneys. The degradation rate can be controlled by adjusting the L:G ratio in the PLGA blocks.
Drug release from the PLGA-PEG-PLGA hydrogel is typically a two-phase process. Initially, the release is governed by the diffusion of the drug through the aqueous channels of the hydrogel matrix. Over the long term, as the polymer matrix begins to break down via hydrolysis, polymer erosion becomes the dominant release mechanism. The initial “burst release” is primarily caused by the rapid diffusion of any drug that is weakly bound or located near the surface of the gel.