By Beata Sweryda-Krawiec and Shyh-Dar Li
Advanced drug delivery systems, including liposomes, polymeric nanoparticles, micelles, and metal nanoparticles, have been extensively studied in the past decade. Meanwhile, natural biomolecules are attractive alternatives to synthetic polymers in the development of novel drug delivery systems. Drug delivery systems have unusual materials requirements that derive mainly from their therapeutic role: to administer drugs over prolonged periods of time, to deliver drugs to the target with minimal systemic exposure, and to release the drug at rates that are independent of patient-to-patient variables.
In general, nucleotide, protein, and peptide delivery systems offer a number of advantages including biocompatibility and biodegradability. These novel drug delivery systems can be prepared under mild conditions without the use of toxic chemicals or organic solvents. They also have defined primary structure and can be easily modified for various surface modifications including covalent attachment of drugs and targeting ligands. They are scalable, tunable, robust, and functional. Here is more about three promising areas of research related to drug delivery systems:
Peixuan Guo, Ph.D., from The Ohio State University, and his group have constructed an assortment of thermodynamically and chemically stable RNA nanoparticles. These self-assembled nanoparticles are resistant to boiling, RNase and 8M urea denaturation, and remain intact after systemic injection. They strongly bind to cancer cells, with undetectable accumulation in organs. These RNA nanoparticles have various applications and uses for cancer immunotherapy, vaccine adjuvant, brain cancer targeting, delivery to liver/lung metastasis of colon cancer, as well as the treatment of gastric and three-negative breast cancers in animal models.
Kun Cheng, Ph.D., from the University of Missouri-Kansas City, is doing research on avidin-biotin interaction, which is one of the strongest non-covalent interactions, and explored it as a very promising platform for drug delivery systems for various pharmaceutical agents including small molecules, proteins, vaccines, monoclonal antibodies, and nucleic acids. His team developed a streptavidin-based multi-component siRNA nanocomplex to deliver siRNA to hepatic stellate cells (HSCs). The nanocomplex can efficiently protect siRNA from degradation in the serum and efficiently deliver the siRNA into HSC in a specific manner.
The biomolecules can also be easily modified by adding functional groups to form various structural forms (self-assembling peptides including hydrogelators), enabling self-assembly on demand under physiological conditions. Sotirios Koutsopoulos, Ph.D., is a research scientist in the Center for Biomedical Engineering at Massachusetts Institute of Technology working on design and characterization of novel self-assembling peptide sequences with applications in biomedical engineering including drug delivery.
Learn more about recent discoveries, the issues, and the most significant advancements and challenges in the field of drug delivery systems constructed using natural biomaterials, such as nucleic acids, proteins, and peptides, at the upcoming symposium The Promises and Challenges of Using Novel Biomaterials for Drug Delivery at the 2016 AAPS National Biotechnology Conference in Boston, on Wednesday, May 18, 2:00 pm–4:30 pm. Guo, Cheng, and Koutsopoulos will each present on their areas of research. Based on the presented work and the discussion, we hope to provide insight into the current state of such drug delivery systems and its implications along with some thoughts on the future directions.