The overall goal of this competing NIH R01 renewal application is to create a tumor-targeted cell-penetrating peptide (CPP) nanoscale drug delivery system to target therapeutic payloads to a wide range of solid tumors. This proposal builds upon the observation that oligoarginine peptides display a strong threshold effect in their cell penetration ability;below a threshold of 6 consecutive arginine (Arg) residues in the CPP, little cell uptake is observed, while above this threshold number of Arg residues, there is significant cell uptake. We hypothesized that this threshold effect is not related to the number of sequential Arg residues in the oligoarginine CPP, but instead is reflective of the local Arg residue density. This hypothesis predicts that the triggered self-assembly of a diblock copolymer, that presents <6 Arg residues on its hydrophilic end, into a micelle should provide a system that exhibits digital """"""""off-on"""""""" cell uptake. To test this hypothesis and develop an externally triggered CPP drug delivery system, thermally responsive diblock copolymers of an elastin-like polypeptide (ELPBCs) will be synthesized such that the number of Arg residues on the hydrophilic terminus of the ELPBC will be below the threshold required for efficient cellular uptake of ELPBC unimers at 37 ?C. In tumors that are externally heated to 39-42 ?C, which is greater than the critical micellization temperature of the ELPBC, the ELPBC will self-assemble into micelles decorated with Arg residues, and the local Arg residue density in the corona of the ELPBC will exceed the threshold required for efficient cellular uptake, thereby resulting in efficient intracellular uptae within the tumor. Arg-presenting ELPBC with a range of architectural variables will be synthesized, tested for self-assembly and stability between 39 and 42 ?C in serum, and their temperature-triggered cellular uptake will be quantified by flow cytometry and visualized by fluorescence microscopy. Optimal Arg-presenting ELPBC selected from these studies will then be tested for their pharmacokinetics, tissue distribution and their ability to regress tumors, when they are fused to gemcitabine that is sequestered within the core of the ELPBC micelles. The significance of this proposal is that it will provide a receptor independent method of actively targeting tumors that is applicable to a broad range of cancer types and circumvents the limitations of receptor targeting;furthermore this targeting modality piggybacks on to existing hyperthermia technology, so that it can be readily deployed in the clinic. The drug carrier design presented here is innovative because it is, to our knowledge, the first attempt to control cellular uptake of cancer therapeutics by manipulating the local density of Arg residues on a nanoscale scaffold by externally triggered self-assembly under clinically relevant conditions.

Public Health Relevance

The proposed research will develop a biodegradable, temperature sensitive polymer that will morph into nanoparticles in tumors that are mildly heated by an external source. These nanoparticles will be decorated with arginine residues on their exterior and will contain a cancer drug. The arginine's will allow efficient uptake of the nanoparticles by cells in the tumor, thereby leading to selective and effective treatment of the tumor by the drug with few side-effects.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB007205-07
Application #
8683172
Study Section
Nanotechnology Study Section (NANO)
Program Officer
Tucker, Jessica
Project Start
2012-07-01
Project End
2016-06-30
Budget Start
2014-07-01
Budget End
2015-06-30
Support Year
7
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Duke University
Department
Biomedical Engineering
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
City
Durham
State
NC
Country
United States
Zip Code
27705
Bhattacharyya, Jayanta; Weitzhandler, Isaac; Ho, Shihan Bryan et al. (2017) Encapsulating a Hydrophilic Chemotherapeutic into Rod-like Nanoparticles of a Genetically Encoded Asymmetric Triblock Polypeptide Improves its Efficacy. Adv Funct Mater 27:
MacEwan, Sarah R; Chilkoti, Ashutosh (2017) From Composition to Cure: A Systems Engineering Approach to Anticancer Drug Carriers. Angew Chem Int Ed Engl 56:6712-6733
Wang, Jing; Dzuricky, Michael; Chilkoti, Ashutosh (2017) The Weak Link: Optimization of the Ligand-Nanoparticle Interface To Enhance Cancer Cell Targeting by Polymer Micelles. Nano Lett 17:5995-6005
Wang, Jing; MacEwan, Sarah R; Chilkoti, Ashutosh (2017) Quantitative Mapping of the Spatial Distribution of Nanoparticles in Endo-Lysosomes by Local pH. Nano Lett 17:1226-1232
Simon, Joseph R; Carroll, Nick J; Rubinstein, Michael et al. (2017) Programming molecular self-assembly of intrinsically disordered proteins containing sequences of low complexity. Nat Chem 9:509-515
Weinberger, Andreas; Walter, Vivien; MacEwan, Sarah R et al. (2017) Cargo self-assembly rescues affinity of cell-penetrating peptides to lipid membranes. Sci Rep 7:43963
Wang, Jing; Bhattacharyya, Jayanta; Mastria, Eric et al. (2017) A quantitative study of the intracellular fate of pH-responsive doxorubicin-polypeptide nanoparticles. J Control Release 260:100-110
Bhattacharyya, Jayanta; Ren, Xiu-Rong; Mook, Robert A et al. (2017) Niclosamide-conjugated polypeptide nanoparticles inhibit Wnt signaling and colon cancer growth. Nanoscale 9:12709-12717
MacEwan, Sarah R; Weitzhandler, Isaac; Hoffmann, Ingo et al. (2017) Phase Behavior and Self-Assembly of Perfectly Sequence-Defined and Monodisperse Multiblock Copolypeptides. Biomacromolecules 18:599-609
Schaal, Jeffrey L; Li, Xinghai; Mastria, Eric et al. (2016) Injectable polypeptide micelles that form radiation crosslinked hydrogels in situ for intratumoral radiotherapy. J Control Release 228:58-66

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