Polymers for Biomedicine: Design, Fabrication, and Applications

The Pokorski Lab’s vision is to develop novel materials for biomedical applications by pursuing interdisciplinary research that combines chemistry, protein engineering and materials science. Our lab uses chemical synthesis, polymer processing and molecular biology to improve upon and introduce new functions into biomacromolecules. Students and postdoctoral fellows will learn a wide breadth of skills including small molecule, peptide, and polymer synthesis, molecular cloning and protein production, cell culture and polymer processing technologies.

Protein/Polymer Hybrid Materials

Proteins are inherently rife with biological functions that can be exploited for therapeutic purposes. These include receptor binding for drug delivery, activation of signaling cascades, and enzyme replacement therapies. Proteins, however, suffer from limited drug loading capacity, circulation lifetime, and in vivo stabilities. Additionally, it is difficult to incorporate full-length proteins into soft materials. Our lab explores the synthesis of novel protein:polymer conjugates to address these problems chemically. Projects in this area range from targeted nanoparticle drug delivery to tissue engineering and regenerative medicine.

Protein Composite Materials

The Pokorski lab is innovating the manufacture of slow-release protein/polymer depot formulations using traditional polymer processing tools. An inherent problem for advanced biomaterials is the lack of scalability, since most materials are fabricated using small-scale batch processes. This research focus uses traditional processing tools, like extrusion or injection molding, to fabricate slow-release protein/polymer blend devices. These devices can be in the form of microneedle patches, microparticles or implants depending on the therapeutic target. The ultimate vision for this research thrust is to develop protein delivery devices that are incredibly inexpensive, eliminate the cold-chain, can be self-applied and, most importantly, will improve therapeutic efficacy.  The future of this project is scale up of implants and patches using injection molding techniques that could be used to distribute vaccine devices in resource poor areas, most notably microneedle patches.

Nanofibers for Regenerative Medicine

The Pokorski lab has been at the forefront of developing coextruded polyester nanofibers as scalable biomaterials. Nanofibrous materials have seen great success in myriad biological applications from drug delivery to advanced bandages, however, few materials derived from nanofibers have been translated to practice. We posit that this is likely due to low throughput manufacturing processes. In collaboration with CLiPS, we have developed a melt-based process to fabricate polymer nanofibers using multi-layered coextrusion and have modified the materials with peptides, proteins, and chemotherapeutics. So far, we have used these materials as platforms for cell differentiation, anti-fouling filters, and advanced bandages. Currently we are exploring stem-cell response under dynamic and responsive mechanical and biochemical conditions. 

Polymer Drug Delivery and Imaging

The Pokorski lab works on the development of  polymers for use in disease treatment. Some of the examples include the use of highly fluorinated polymers for both MR imaging and drug delivery to various cancer subtypes. These polymers show exceptional self-assembly behaviors, high drug loading, but more importantly excellent biodistribution. Additional interest in the lab comes in the development of polymers for treatment of microbial infections that have typically been neglected by the nanomedicine community. Our most recent successes have come in the aqueous delivery of photodynamic therapy to drug resistant fungi. The future of these projects includes combination drug delivery to resistant cancers and cell-specific delivery to fungal and bacterial infections. 

Jon Pokorski    |    858.246.3183    |    jpokorski@ucsd.edu