Temperature-responsive Liposome Development Service

Temperature-responsive liposomes are one of the most representative types of stimuli-responsive liposomes, capable of delivering drugs to target tissues that are locally heated, as well as to intracellular organelles. Creative Biolabs is committed to developing advanced temperature-responsive liposomes to meet the evolving needs of modern therapeutics. Choose us as a reliable partner in advancing your projects with cutting-edge technology and proven results!

What are Temperature-responsive Liposomes?

Temperature-responsive liposomes, also known as thermosensitive liposomes, can rapidly and effectively release drugs at temperatures exceeding physiological levels. As a type of triggerable nanoparticle, they can be integrated with thermotherapy to achieve controlled drug release. These liposomes release drugs via two primary mechanisms: extravascular-triggered and intravascular-triggered. Extravascular-triggered release relies on the accumulation of liposomes followed by extravasation via the enhanced permeability and retention (EPR) effect, which then triggers drug release at mild hyperthermia. In contrast, intravascular-triggered release does not depend on the EPR effect, allowing drug release within the microvasculature in heated environments.

Fig.1 Schematic of intravascular triggered drug release.^{1, 2}

Preparation of Temperature-responsive Liposomes

There are primarily two strategies for preparing stimuli-responsive liposomes: leveraging the phase transition of the lipid membrane to respond to stimuli, and modifying the liposomes with stimuli-responsive polymers.

• Phospholipids

The phospholipids that construct liposomes possess specific phase transition temperatures (Tm). Below Tm, the lipid membrane remains stable. When the temperature reaches Tm, the lipids transition from a gel to a liquid phase. At Tm, the stable lipid membrane transitions from an ordered gel phase to a disordered and loosely liquid crystalline phase. This transformation increases the fluidity and permeability of the lipid membrane, thereby facilitating drug release. Generally, different lipids can be mixed to adjust Tm. For example, liposomes prepared from DPPC and DSPC (molar ratio 3:1) showed a 100-fold increase in drug release at 44 °C compared to physiological temperature.

• Temperature-responsive Polymers

Hydrophobic interactions between side chain units, as well as hydrogen bonds between water molecules and polar groups inside the side chains, regulate the thermal responsiveness of temperature-responsive polymers. When the temperature deviates from a specific range, the temperature-responsive polymers exhibit phase separation, leading to abrupt changes in solubility. The temperature at which phase separation occurs above a specific threshold is referred to as the upper critical solution temperature (UCST), while the temperature below which phase separation occurs is known as the lower critical solution temperature (LCST).

Factors Influencing Temperature-responsive Liposomes Drug Delivery

• Lipid composition
• Plasma stability
• Vascular permeability
• Temperature (target tissue and body)
• Hyperthermia duration and timing
• Volume of hyperthermia

Advantages of Temperature-responsive Liposomes

Two key benefits of using temperature-responsive liposomes in combination with hyperthermia are as follows:

• It improves drug delivery to the disease site by increasing vascular permeability and interstitial transport while reducing delivery to healthy tissues.
• Hyperthermia can increase the permeability of the lipid bilayer, allowing the drug to be released more easily.

Heating Method for Triggered Release

• Temperature-responsive liposomes can deliver drugs to tumors locally with less systemic toxicity when combined with hyperthermia.
• Radiofrequency ablation (RFA)
• High-intensity focused ultrasound (HIFU)
• The light source for inducing localized hyperthermia (infrared lasers, cold light lamps, etc.)

Application of Temperature-responsive Liposomes

• Image-guided drug delivery
• Controlled release drugs
• Medical dressings
• Vaccine delivery
• Tumor targeting

At Creative Biolabs, we pride ourselves on our extensive expertise in the development of temperature-sensitive liposomes. Contact us to us now to discover how our cutting-edge temperature-responsive liposome solutions can enhance your research and propel advancements in medical science.

For Research Use Only. Not For Clinical Use