Custom ROS-Responsive Liposome Service

Intelligent, controllable, and efficient stimulus-responsive drug delivery carriers are currently the focus of research and clinical trials in drug delivery systems. BOC Sciences has advanced lipid preparation technologies and established a multifunctional lipid platform to support various research in drug development.

What is ROS-Responsive Liposome

• Stimulus-Responsive Carriers

Stimuli-responsive carriers can not only enhance the accumulation of drugs at the tumor site, but also enable precise control over drug release. Stimuli-responsive carriers include pH-responsive carriers, reduction-responsive carriers, light-responsive carriers, ultrasound-responsive carriers, magnetic-responsive carriers, thermal-responsive carriers, and reactive oxygen species (ROS)-responsive carriers, etc. Among them, ROS-responsive carriers have the advantages of fast response and high sensitivity, mainly targeting responses to hydrogen peroxide (H₂O₂), singlet oxygen (¹O₂), hydroxyl radicals (·OH), and superoxide, etc. inside the cells.

• ROS-Responsive Liposomes

Reactive oxygen species (ROS) mainly refer to a type of free radical in cells that is produced by mitochondria and often has high oxidizing activity. ROS-responsive liposomes are prepared based on the high expression of ROS in the tumor microenvironment. Researchers modify the phospholipids with special structures such as thioether, boronic ester, and ferrocene through chemical synthesis methods. When the prepared liposomes reach the tumor site, their lipid membrane structure changes under the oxidation of ROS, resulting in the release of encapsulated drugs. In addition, phospholipids containing unsaturated carbon-carbon bonds, such as Egg PC, DOPC, and 18:2 (Cis) PC, can be directly added in liposome formulations. Unsaturated carbon-carbon bonds can react with ROS, triggering changes in the lipid membrane structure and achieving the goal of drug release.

Fig. 1 Liposomal release driven by ROS/H₂O₂ addition.

• Application of ROS-Responsive Liposomes

(1) Combine ROS-responsive drug delivery strategies with other stimuli-responsive strategies, such as pH-sensitive and GSH-sensitive.

(2) Combine ROS-responsive drug delivery strategies with other therapeutic strategies, such as thermotherapy, photodynamic therapy, ultrasound therapy, near-infrared therapy, and evaluate treatment efficacy by combined fluorescence imaging.

BOC Sciences' Custom ROS-Responsive Liposome Services Details

Services Related to Custom ROS Responsive Liposomes

(1) Particle size and zeta potential

Particle size: The particle size of liposomes is typically between 50-200 nm, but can be adjusted through different preparation methods and composition. Smaller liposomes can more easily penetrate tissue barriers such as cell membranes and the blood-brain barrier to reach target cells. Larger liposomes have higher drug stability and loading capacity.

Zeta potential: Zeta potential is a measure of surface charge that reflects the stability and dispersibility of liposomes. Liposomes with high negative charges typically have better stability and lower aggregation tendencies due to their stronger repulsion forces.

(2) Encapsulation efficiency and drug loading

Encapsulation efficiency is the proportion of the internal drug volume in liposomes to the total volume, meaning that a higher encapsulation efficiency indicates a higher drug concentration inside the liposome and can enhance the effectiveness of the drug.

Drug loading capacity refers to the maximum amount of drug that can be contained in a unit weight of liposome. A higher drug loading capacity means that more drug can be contained in a unit weight of liposome, which can improve the efficacy of the drug.

(3) Morphology of liposomes

The size and shape of the liposomes have an impact on the stability and solubility of drugs, as well as affecting the drug loading capacity and release rate of liposomes.