Research — David Thompson Group

RESEARCH OVERVIEW

WHAT WE DO IN THE THOMPSON LAB…

We are developing novel synthetic chemical and biochemical tools to address fundamental problems in human health, with a special emphasis on continuous flow chemistry, delivery of nucleic acid nanoparticles, accelerated protein structure determination using cryo-EM, and lysosomal storage disorder therapeutics. Development of efficient chemoselective routes to these materials is a major focus of our research. We are also exploring the effects of particle shape, size, and environmentally responsive transformations (e.g., pH, enzyme, light, ultrasound) on therapeutic performance. Translation of these basic studies to animal models of disease (e.g., bladder, lung, pancreatic & breast tumors) is the near-term goal of our materials development efforts.

Click on the links or scroll down for a brief description of these research projects. Check out our publications page to learn more about our projects.

RESEARCH TOPICS

Continuous Flow Chemistry
Nucleic Acid Delivery
Accelerated protein structure
Lysosomal Storage Disorder therapeutics

CONTINUOUS FLOW CHEMISTRY

Continuous flow chemistry offers a variety of advantages over traditional batch processes, by providing rapid, efficient mixing, superior heat transfer, and safe operation at high temperatures and pressures. Due to these attractive characteristics, along with an inherent potential for high scalability within a smaller physical footprint, flow chemistry has generated significant interest within the pharmaceutical industry for improving synthesis efficiency. Our lab utilizes the benefits of flow chemistry for two broad applications: organic synthesis and nanoparticle assembly. In collaboration with several research groups at Purdue, we are developing a multi-scale synthesis platform capable of optimizing synthesis routes for a broad range of common active pharmaceutical ingredients (APIs). Our system incorporates microreactors in the size range of 0.5-19.5 μL that have been coupled with on-line and off-line mass spectrometry (MS) for reaction monitoring and route optimization. We have also used these microreactors to control self-assembly reactions for the rapid and stepwise formulation of multifunctional nucleic acid-loaded therapeutic nanoparticles with excellent control over their physical properties and biological performance.

SELECTED PUBLICATIONS

“Multistep Flow Synthesis of Diazepam Guided by Droplet Reaction Screening With Mechanistic Insights from Rapid MS Analysis”, Organic Process
Research & Development 2017, DOI: 10.1021/acs.oprd.7b00218.

“Reaction Screening and Optimization of Continuous-Flow Atropine Synthesis by Preparative Electrospray Mass Spectrometry”, Analyst 2017, DOI:
10.1039/C7AN00622E.

“Mass Spectrometry Directed System for the Continuous-Flow Synthesis and Purification of Diphenhydramine”, Chemical Science2017 8, 4363-4370.

“Can Accelerated Reactions in Droplets Guide Chemistry at Scale?”, European Journal of Organic Chemistry 2016, 5480-5484.

“Influence of Molecular Structure on the In Vivo Performance of Flexible Rod Polyrotaxanes”, Biomacromolecules 2016 17, 2777-2786.

“Impact of Mixed b-Cyclodextrin Feeds on Pluronic Rotaxanation Efficiency and Product Solubility”, ACS Applied Materials & Interfaces 2015 7, 23831-23836.

“Effect of Pendant Group on pDNA Delivery by Cationic-b-Cyclodextrin:Alkyl-PVA-PEG Pendant Polymer Complexes”, Biomacromolecules 2014 15, 12-19.

DELIVERY OF NUCLEIC ACID AND NANOPARTICLES

Design and synthesis of new materials that utilize constitutive endosomal uptake and processing mechanisms to improve the delivery and performance of small molecule and nucleic acid biotherapeutics are a major focus in the Thompson Lab. The bioresponsive carrier systems we prepare — e.g., lipids, lipopeptides, lipopolymers, polyrotaxanes, diblock copolymers, and host:guest pendant polymers—are designed to degrade upon internalization within endosomes to release their therapeutic cargo into the cytosol of target cells. These basic studies are directed toward elucidating the fundamental material properties that influence carrier system efficacy in human tissue culture, primary dendritic cells, and animal models of cancer (bladder, lung, breast, and pancreatic).

SELECTED PUBLICATIONS

“Development and In Vitro Characterization of Bladder Tumor Cell Targeted Lipid-Coated Polyplex for Dual Delivery of Plasmids and Small Molecules”, International Journal of Nanomedicine201914, 9547-9561.

“Development of Dihydrochalcone-functionalized Gold Nanoparticles for Augmented Antineoplastic Activity”, International Journal of Nanomedicine201813, 1917-1926.

“PLGA-PEG Nano-delivery System for Epigenetic Therapy”, Biomedicine & Pharmacotherapy 2017 90, 586-597.

“Targeting and Internalization of Liposomes by Bladder Tumor Cells Using a Fibronectin Attachment Protein-Derived Peptide-Lipopolymer Conjugate”, Bioconjugate Chemistry 2017 28, 1481-1490.

“Pluronic based b-Cyclodextrin Polyrotaxanes for Treatment of Niemann-Pick Type C Disease”, Scientific Reports 2017 7, 46737.

“Impact of Surfactant Treatment of Paclitaxel Nanocrystals on Biodistribution and Tumor Accumulation in Tumor-bearing Mice”, Journal of Controlled Release 2016 237, 168-176.

“Mechanistic Insight into Receptor-mediated Delivery of Cationic-β-Cyclodextrin:Hyaluronic Acid-Adamantane Host:Guest pDNA Nanoparticles to CD44+ Cells”, Molecular Pharmaceutics 2016 13, 1176-1184.

“Structure-Property Relationship for siRNA Delivery Performance of Cationic 2-Hydroxypropyl-b-cyclodextrin: Poly(ethylene glycol)-Poly(propylene glycol)-Poly(ethylene glycol) Polyrotaxane Vectors”, Biomaterials 2016 84, 86-98.

“Efficient pDNA Delivery Using Cationic 2-Hydroxypropyl-β-Cyclodextrin Pluronic based Polyrotaxanes”, Macromolecular Bioscience 2016 16, 63-73. (journal cover)

“Decitabine Nanoconjugate Sensitizes Human Glioblastoma Cells to Temozolomide”, Molecular Pharmaceutics 2015 12, 1279-1288.

MATERIALS FOR ACCELERATED PROTEIN STRUCTURE DETERMINATION

The long-term objective of this work is the development of novel materials and methods for rapid structural analysis of proteins at high resolution to enable structure-based drug design for important unmet disease targets. Our strategies utilize high affinity interactions to immobilize protein targets onto TEM grids for single particle reconstruction analysis.

SELECTED PUBLICATIONS

“Selective Capture of Histidine-tagged Proteins from Cell Lysates Using TEM Grids Modified with NTA-Graphene Oxide”, Scientific Reports 2016 6, 32500.

“Non-fouling NTA-PEG-based TEM Grid Coatings for Selective Capture of Histidine-tagged Protein Targets from Cell Lysates”, Langmuir 2016 32, 551-559.

“Single-step Antibody-based Affinity Cryo-Electron Microscopy for Imaging and Structural Analysis of Macromolecular Assemblies”, Journal of Structural Biology 2014 187, 1-9.

LYSOSOMAL STORAGE DISORDER THERAPEUTICS

Niemann-Pick Type C (NPC) and Stargardt Disease (SD) are a rare, panethnic diseases that are among the 46 different lysosomal storage disorders known. NPC patients suffer from accumulation of unesterified cholesterol in the lysosomes of their cells, ultimately leading to cell death and the development of neurological and multiple organ dysfunction. Several lines of evidence suggest that 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) derivatives are able to initiate the efflux of aberrantly stored unesterified cholesterol from the late endosomal/lysosomal (LE/LY) compartments of NPC-deficient cells and extend lifetime in animal models of NPC disease. Unfortunately, these effects are temporary after a single dose of HP-β-CD, therefore, repeated injections or continuous infusions are required to produce durable responses. In an effort to make HP-β-CD treatment a more efficacious, safe, and long-lasting therapeutic option, we have developed a family of HP-β-CD polyrotaxanes derived from biocompatible triblock copolymers that are enzymatically activated to release multiple copies of HP-β-CD within the LE/LY to remove cholesterol deposits that have accumulated in this cellular compartment. SD, a childhood blinding. dis-order, arises from aberrant accumulation of bisretinoids in the retinal pigmented epithelium leading to necroptosis within the retina. Polyrotaxane derivatives and small molecules that enhance bisretinoid clearance and suppress the necroptosis pathway are under development.

SELECTED PUBLICATIONS

“Synthesis, Characterization, and Evaluation of Pluronic-based b-Cyclodextrin Polyrotaxanes for Mobilization of Accumulated Cholesterol from Niemann-Pick Type C Fibroblasts”, Biochemistry 2013 52, 3242-3253.

“Synthesis of 2-Hydroxypropyl-b-Cyclodextrin and Pluronic Based Polyrotaxanes in Heterogeneous Reactions for Niemann-Pick Type C Therapy”, Biomacromolecules 2013 14, 4189-4197.

“Pluronic based b-Cyclodextrin Polyrotaxanes for Treatment of Niemann-Pick Type C Disease”, Scientific Reports 2017 7, 46737.

“Synthesis of Hydroxypropyl-b-Cyclodextrin:Poly(decamethylenephosphate) and Evaluation of its Cholesterol Efflux Potential in Niemann-Pick C1 Cells”, Journal of Materials Chemistry B 2019 7, 528-537.