Light-responsive Liposome Development Service

Creative Biolabs stands at the forefront of light-responsive liposome technology, offering unparalleled advantages in the field of targeted drug delivery. With a robust portfolio of innovative solutions, we have established ourselves as a leader in precision medicine, providing cutting-edge liposomes that respond to specific wavelengths of light, enabling controlled and targeted release of therapeutic agents.

Background

Light is a clean and effective external stimulus, eschewing the need for physical contact. In contrast to other stimulus such as temperature and pH, light is favored for its robustness within biological environment, adjustable intensity, precise spatiotemporal control, and non-invasive nature. It is a form of electromagnetic (EM) radiation that spans a broad spectrum of wavelengths, with commonly utilized EM radiations including ultraviolet (UV) light, visible light, and near-infrared (NIR) radiation. Generally, the penetration depth increases with the wavelength.

• UV (200-400 nm): UV irradiation provides sufficient energy to initiate photochemical reactions in most light-responsive materials, including photoisomerization, photocleavage, and decrosslinking reactions, making it one of the most commonly used light sources. However, its application is limited by its low tissue penetration and phototoxicity, making it the preferred choice for treating early-stage (superficial) dermatological conditions.
• Visible light (400-700 nm): Visible light possesses high energy and exhibits limited tissue penetration depth.
• NIR (700-1000 nm): Due to the minimal attenuation and refraction of biomolecules and endogenous chromophores, NIR light possesses the advantage of penetrating deeper into tissues with minimal damage to normal cells. However, its energy is insufficient to induce photochemical reactions, meaning that only a limited number of light-responsive materials can directly respond to NIR light. Consequently, NIR light is the preferred choice for the treatment of advanced (deep) dermatological conditions.

Fig.1 Light source used for responsive release.

Opting for a light source with an appropriate wavelength is essential for modulating the depth and energy of tissue penetration. Generally, the most suitable wavelength for in vivo applications ranges from 650 to 900 nm, with tissue penetration depths in the millimeter range.

What is Light-responsive Liposome?

Light-responsive liposomes, also known as photosensitive liposomes, incorporate light-responsive materials either encapsulated within the liposomal structure or attached to its exterior. Upon exposure to specific light sources, these light-responsive materials absorb light energy, triggering chemical reactions or thermal effects that alter the properties and structure of the liposomes, facilitating drug release. By adjusting the duration and area of light exposure, precise spatiotemporal and dosage-controlled drug delivery can be achieved at the target site.

The intriguing aspect of light-responsive liposomes lies in their dual capability to deliver both chemotherapy and photothermal/photodynamic therapy. Photothermal therapy harnesses the conversion of light energy into heat through laser irradiation, thereby inducing ablation of tumor cells in proximity to the photothermal agents. Photodynamic therapy, on the other hand, activates photosensitizers with specific wavelengths of light, transforming oxygen in the tumor region into reactive oxygen species, which subsequently leads to the apoptosis of tumor cells.

Mechanisms of Drug Release in Light-responsive Liposome

The mechanisms of drug release in light-responsive liposomes are grounded in photochemical, photothermal, and photoisomerization processes.

• Photochemical Triggering: The release of drugs triggered by photochemistry is achieved by irradiation that cleaves photocleavable covalent bonds present within the liposomes.
• Photothermal Triggering: Drug release induced by photothermal reactions can effectively utilize the transfer of photothermal energy to affect the thermosensitive components of liposomes, thereby triggering drug release. Photothermal agents such as gold nanomaterials exhibit excellent photothermal conversion efficiency, strong light absorption, and good photostability.
• Photoisomerization: Drug release based on photoisomerization refers to the destabilization of liposomes following changes in molecular conformation upon light absorption, which in turn triggers drug release. Light irradiation can induce reversible photoisomerization reactions in certain organic compounds, including spiropyrans and azobenzenes, without the production of by-products.

Fig.2 Light-triggered mechanisms used in triggering drug release from liposomes.¹

Light-responsive Materials

UV, visible, and NIR light are extensively employed to trigger drug release within liposomes, with the choice of the light source being contingent upon the characteristics of the light-responsive materials and the composition of the liposomes. Ideal light-responsive liposomes should meet the following criteria for light-responsive materials:

1. Light-responsive materials encapsulated within the liposomes should retain good photoreactivity, exhibiting a high sensitivity to external light exposure.
2. Light-responsive material particles should be sufficiently small and stable, suitable for encapsulation within the aqueous phase or phospholipid bilayer of the liposomes, and able to coexist with the liposomes for extended periods without alteration.
3. Light-responsive materials should not significantly affect the stability and encapsulation efficiency of the liposomes into which they are incorporated.

Advantages of Light-responsive Liposome by Creative Biolabs

• Repeatability: Our liposomes are designed for sustained drug delivery over extended periods, ensuring consistent therapy outcomes.
• Controlled Release: We offer precise control over the timing, location, and dosage of drug release, maximizing therapeutic efficacy.
• Combination Therapy: Our liposomes synergize chemotherapy with photothermal therapy, enhancing treatment outcomes through the combined effects.
• Customized Solutions: Delivering tailored solutions to align with the unique requirements of your medicinal endeavors.
• Invasive-Free Delivery: Facilitating precise medication deployment through our light-responsive liposome, essential for pinpoint therapeutic interventions.
• Comprehensive Development and Characterization Platform: Equipped with cutting-edge resources for liposome preparation and analysis, guaranteeing superior quality and streamlined operations.

To learn more about how Creative Biolabs' light-responsive liposomes can elevate your pharmaceutical applications to new heights, we encourage you to contact us.

For Research Use Only. Not For Clinical Use