Liposomes are phospholipid bilayers modified to take a spherical form. The bilayer surrounds an aqueous core; this enables the liposomes to encapsulate both hydrophilic and hydrophobic active compounds. Liposomes are non-toxic and non-immunogenic, as well as biocompatible and biodegradable. Their surfaces can be modified by targeting ligands such as antibodies. These attributes combined make liposomes ideal candidates for delivery vectors for a wide variety of active components.
We regularly use liposomes to encapsulate the following components:
mRNA, siRNA, and DNA
In particular, two mRNA-based COVID-19 vaccines rely on pegylated liposomes to enable mRNA delivery (MRNA-1273 from Moderna and BNT162b2 from BioNTech/Pfizer).
We have developed novel, automated, continuous flow, microfluidic approaches that enable scalable fabrication of highly monodisperse, run-to-run consistent liposomes and lipid nanoparticles in the size range of 35 – 400 nm.
Dendrimers are a class of hyper-branched polymers that can be formed into small 1-10 nm spherical structures. These materials possess unique properties that make them excellent candidates for solubilization and delivery vectors for hydrophobic active components.
Dendrimers contain large hydrophobic pockets/cavities that enable encapsulation at a very high active-to-carrier ratio. The hydrophobic cavities can be tailored to encapsulate, coordinate, or conjugate active components to fine-tune the strength of binding between the payload and the carrier.
Dendrimers are smaller than liposomes and other polymer nanoparticles giving them a high surface-to-volume ratio. This, combined with adaptable surface composition, enables highly effective aqueous solubilization and long-term stability in aqueous solutions.
These materials have similar structures to biological molecules such as insulin, cytochrome C, and hemoglobin.
Dendrimers have no intrinsic taste and can effectively coordinate to active components, making them ideal for taste-masking applications.
We have developed a novel, automated, continuous flow, microfluidic approaches that enable a scalable fabrication range of dendrimer formulations based on Poly(amidoamine) (PAMAM), poly(propylene imine) (PPI), and Tecto dendrimers.
PLGA (poly(lactic-co-glycolic acid)) is a material most commonly associated with controlled-release applications. Under physiological conditions, the co-polymer breaks up into lactic and glycolic acids releasing the encapsulated material. By manipulating the particle's size, molecular weight, and composition, we can create controlled release profiles that last from a couple of hours to several days.
PLGA itself is hydrophobic and is therefore used with oil-soluble API. The surface of the particle can be made hydrophilic, enabling solubilization of the formulation in aqueous solutions.
The surface groups can be modified to fine-tune the properties of the particles. Frequently we tether PEG molecules to the PLGA core. These surface functional groups can then be functionalized with antibodies enabling targeted delivery applications.
We have developed a novel, automated, continuous flow, microfluidic approaches that enable a scalable fabrication of uniform run-to-run consistent PLGA nanoparticle in the size range of 50 – 600 nm.