HER-2-Targeted Nanoparticle-Affibody Bioconjugates for Cancer Therapy

Affibodies are a class of polypeptide ligands that are potential candidates for cell- or tissue-specific targeting of drug-encapsulated controlled release polymeric nanoparticles (NPs). Here we report the development of drug delivery vehicles comprised of polymeric NPs that are surface modified with Affibody ligands that bind to the extracellular domain of the trans-membrane human epidermal growth factor receptor 2 (HER-2) for targeted delivery to cells which over express the HER-2 antigen. NPs lacking the anti-HER-2 Affibody did not show significant uptake by these cells. Using paclitaxel encapsulated NP-Affibody (1 wt% drug loading), we demonstrated increased cytotoxicity of these bioconjugates in SK-BR-3 and SKOV-3 cell lines. These targeted, drug encapsulated NPAffibody bioconjugates may be efficacious in treating HER-2 expressing carcinoma

Microfluidic channel optimization to improve hydrodynamic dissociation of cell aggregates and tissue.

Maximizing the speed and efficiency at which single cells can be liberated from tissues would dramatically advance cell-based diagnostics and therapies. Conventional methods involve numerous manual processing steps and long enzymatic digestion times, yet are still inefficient. In previous work, we developed a microfluidic device with a network of branching channels to improve the dissociation of cell aggregates into single cells. However, this device was not tested on tissue specimens, and further development was limited by high cost and low feature resolution. In this work, we utilized a single layer, laser micro-machined polyimide film as a rapid prototyping tool to optimize the design of our microfluidic channels to maximize dissociation efficiency. This resulted in a new design with smaller dimensions and a shark fin geometry, which increased recovery of single cells from cancer cell aggregates. We then tested device performance on mouse kidney tissue, and found that optimal results were obtained using two microfluidic devices in series, the larger original design followed by the new shark fin design as a final polishing step. We envision our microfluidic dissociation devices being used in research and clinical settings to generate single cells from various tissue specimens for diagnostic and therapeutic applications

Microfluidic channel optimization to improve hydrodynamic dissociation of cell aggregates and tissue.

Maximizing the speed and efficiency at which single cells can be liberated from tissues would dramatically advance cell-based diagnostics and therapies. Conventional methods involve numerous manual processing steps and long enzymatic digestion times, yet are still inefficient. In previous work, we developed a microfluidic device with a network of branching channels to improve the dissociation of cell aggregates into single cells. However, this device was not tested on tissue specimens, and further development was limited by high cost and low feature resolution. In this work, we utilized a single layer, laser micro-machined polyimide film as a rapid prototyping tool to optimize the design of our microfluidic channels to maximize dissociation efficiency. This resulted in a new design with smaller dimensions and a shark fin geometry, which increased recovery of single cells from cancer cell aggregates. We then tested device performance on mouse kidney tissue, and found that optimal results were obtained using two microfluidic devices in series, the larger original design followed by the new shark fin design as a final polishing step. We envision our microfluidic dissociation devices being used in research and clinical settings to generate single cells from various tissue specimens for diagnostic and therapeutic applications