Exosome-Based Drug Delivery System Development for Stroke

Exosomes are nano-sized lipid bilayer encapsulated extracellular vehicles (EVs). Their inherent properties, such as stability, biocompatibility, low immunogenicity, and ability to cross biological barriers, have generated interest in the use of exosomes as drug delivery vehicles. Studies have shown that exosomes modulate stroke through multiple mechanisms, including improving neuronal communication, promoting neurovascular remodeling, and maintaining nervous system homeostasis. At the same time, exosomes are also ideal carriers of bioactive substances that can be modified and targeted to lesion sites. Therefore, exosomes are highly desirable and effective drug delivery systems for stroke.

Fig. 1. Overview of exosome bioengineering for better ischemic stroke therapy. (Khan et al., 2021)

Our Exosome-Based Drug Delivery System Development Services

Based on our understanding of the role of exosomes in cerebral ischemia, Ace Therapeutics offers exosome-based drug delivery system development services to improve the ability of stroke drugs to cross the BBB.

Isolation and Characterization of Exosomes

The key to better analyzing the content and function of exosomes is to obtain high-quality exosomes. Ace Therapeutics can isolate exosomes from a variety of samples, including blood, urine, plasma, and cerebrospinal fluid. We offer a variety of methods to help clients isolate, purify, and characterize exosomes.

• Isolation of exosomes: We can isolate exosomes by a variety of methods, such as density gradient separation, tangential flow filtration, size exclusion chromatography (SEC).
• Characterization of exosomes: Nanoparticle tracer analysis to measure particle size, Western blotting and flow cytometry to analyze exosome surface proteins (e.g., CD63, CD8, TSG101, flotillin-1, ALIX, CD9, CD81, CD82), and electron microscopy for direct visualization of morphology and particle size of exosomes.

Bioengineering of Brain-Targeted Exosomes

Ace Therapeutics offers multiple strategies to modify exosomes for stroke drug delivery, improving their ability to cross the BBB, concentration at the target site, circulation time, and in vivo half-life.

Exosome Bioengineering

• Engineering of exosome-producing cells (using cells to transfect, activate or incubate drugs).
• Exosome engineering through genetic and chemical methods for targeted drug delivery.

Exosome Surface Modification

We offer exosome surface manipulation strategies to increase the circulation and residence time and targeting of exosomes.

• Exosomes coated with polyethylene glycol
• Brain-targeted peptide (LDL) modification of exosomes

Exosomes Loaded with Stroke Drugs

Our team of experts can help clients optimize exosomes for drug delivery to realize their full potential as drug delivery vehicles. We offer a variety of methods, including passive loading and active loading, to load stroke drugs into exosomes. We will select and design an appropriate drug loading strategy based on the specific drug and its properties, as well as the desired release mechanism.

• Passive loading: We treat the cells with stroke drugs and naturally incorporate the drug into the exosomes as they form. This method is suitable for lipophilic drugs that can easily cross cell and vesicle membranes.
• Active loading: We load stroke drugs directly into isolated exosomes using a variety of techniques (e.g., heat shock, sonication, electroporation, the use of saponins, or incubation with detergents) that increase exosome membrane permeability. This approach allows for higher loading efficiency and more precise control of drug loading amount.

Preclinical Studies of Exosome-Based Drug Delivery Systems Against Stroke

Ace Therapeutics offers a range of services to test the delivery efficiency of drug-loaded exosomes and perform comprehensive evaluations in cells or animals.

• We offer pharmacokinetic models to evaluate the distribution and uptake of drug-loaded exosomes.
• We provide in vitro BBB models to assess the BBB permeability of drug-loaded exosomes.
• We provide various in vitro and in vivo models of stroke to test the therapeutic effect of drug on stroke.
• We identify whether the drug is loaded or not by transmission electron microscopy.

Ace Therapeutics provides reliable preclinical development services for exosome-based drug delivery system, including drug release stability, brain neuronal cell reconstruction, immunomodulatory functions, targeted therapies, and targeted delivery across the BBB. If you are interested in our services, please do not hesitate to contact us!

1. Khan, H., et al. (2021). Native and bioengineered exosomes for ischemic stroke therapy. Frontiers in Cell and Developmental Biology, 9, 619565.