Polymeric nanoparticles are versatile drug carriers and have shown great potentials in cancer therapy. Biodegradable polymers such as polylactide (PLA), poly(lactide-co-glycolide) (PLGA), polycaprolactone (PCL) and polyethylene glycol (PEG) are frequently used to encapsulate APIs into nanoparticles for a variety of drug delivery applications.
Potential benefits of drug encapsulation in nanoparticles include:
- Protection of API from Degradation
Often, drug molecules are hydrolyzed or degraded before reaching their targeted places. Nanoparticles shield the drug from degrading factors such as enzymes in the body fluids until they are released from the particles at the destination site.
- Passive Targeting
Due to their compromised vasculatures, cancerous cells may be subject to the enhanced permeability and retention (EPR) effect. EPR effect is the property by which particles in the size range of 10 – 500 nm tend to accumulate in tumor tissue much more than they do in normal tissues. It is becoming a common strategy to exploit the EPR effect for the delivery of therapeutic agents to tumor sites.
- Targeted Drug Delivery with Surface Coating or Conjugation
Development of targeted delivery platforms that can reduce toxicity and other side effects and maintain or improve the therapeutic index is the ultimate goal of cancer therapy. This can be achieved by physically coating or chemically conjugating a targeting agent onto the surface of drug-loaded nanoparticles.
- Extended Circulation Time
The surface of API-loaded nanoparticles may be treated with a hydrophilic entity so that the nanoparticles can circulate in the blood for extended times and thus have a better chance to reach the target. One example of such techniques is PEGylation, which involves the addition of polyethylene glycol to the surface of the nanoparticles.PEGylation can be done by either including a PEG copolymer into the starting formula of the nanoparticle preparation or by coating or conjugation after the nanoparticles are produced.
- Varying Surface Charge to Promote Cell Entry
The surface charge of API-loaded nanoparticles can be varied to facilitate cell entry. Depending on each specific need, the particle surface can be made positively, neutrally or negatively charged.
- Fluorescent Labeling for Imaging
A fluorescent agent can be incorporated into the nanoparticles along with the API so that the entire nanoparticle can be imaged in vivo. Alternatively, the dye can be conjugated to the surface of API loaded nanoparticles.
Phosphorex is capable of encapsulating small molecule or biologic APIs into polymeric nanoparticles in the size range of 50 nm to 1 mm. We can fabricate the particles, modify their surface for different targeting needs, scale up to support preclinical and IND-enabling studies, and develop GMP processes.