101
|
Peng LX, Ivetac A, Van S, Zhao G, Chaudhari AS, Yu L, Howell SB, McCammon JA, Gough DA. Characterization of a clinical polymer-drug conjugate using multiscale modeling. Biopolymers 2010; 93:936-51. [PMID: 20564048 PMCID: PMC3099131 DOI: 10.1002/bip.21474] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The molecular conformation of certain therapeutic agents has been shown to affect the ability to gain access to target cells, suggesting potential value in defining conformation of candidate molecules. This study explores how the shape and size of poly-γ-glutamyl-glutamate paclitaxel (PGG-PTX), an amphiphilic polymer-drug with potential chemotherapeutic applications, can be systematically controlled by varying hydrophobic and hydrophilic entities. Eighteen different formulations of PGG-PTX varying in three PTX loading fractions (f(PTX)) of 0.18, 0.24, and 0.37 and six spatial arrangements of PTX ('clusters', 'ends', 'even', 'middle', 'random', and 'side') were explored. Molecular dynamics (MD) simulations of all-atom (AA) models of PGG-PTX were run until a statistical equilibrium was reached at 100 ns and then continued as coarse-grained (CG) models until a statistical equilibrium was reached at an effective time of 800 ns. Circular dichroism spectroscopy was used to suggest initial modeling configurations. Results show that a PGG-PTX molecule has a strong tendency to form coil shapes, regardless of the PTX loading fraction and spatial PTX arrangement, although globular shapes exist at f(PTX) = 0.24. Also, less uniform PTX arrangements such as 'ends', 'middle', and 'side' produce coil geometries with more curvature. The prominence of coil shapes over globules suggests that PGG-PTX may confer a long circulation half-life and high propensity for accumulation to tumor endothelia. This multiscale modeling approach may be advantageous for the design of cancer therapeutic delivery systems. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 936-951, 2010.
Collapse
Affiliation(s)
- Lili X. Peng
- Department of Bioengineering, University of California at San Diego, La Jolla, CA
| | - Anthony Ivetac
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA
| | - Sang Van
- Nitto Denko Technical Corporation, Oceanside, CA
| | - Gang Zhao
- Nitto Denko Technical Corporation, Oceanside, CA
| | - Akshay S. Chaudhari
- Department of Bioengineering, University of California at San Diego, La Jolla, CA
| | - Lei Yu
- Nitto Denko Technical Corporation, Oceanside, CA
| | - Stephen B. Howell
- Moores Cancer Center, University of California at San Diego, La Jolla, CA
| | - J. Andrew McCammon
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA
| | - David A. Gough
- Department of Bioengineering, University of California at San Diego, La Jolla, CA
| |
Collapse
|
102
|
Abstract
Functional nanomaterials based on molecular self-assembly hold great promise for applications in biomedicine and biotechnology. However, their efficacy could be a problem and can be improved by precisely controlling the size, structure, and functions. This would require a molecular engineering design capable of producing monodispersed functional materials characterized by beneficial changes in size, shape, and chemical structure. To address this challenge, we have designed and constructed a series of amphiphilic oligonucleotide molecules. In aqueous solutions, the amphiphilic oligonucleotide molecules, consisting of a hydrophilic oligonucleotide covalently linked to hydrophobic diacyllipid tails, spontaneously self-assemble into monodispersed, three-dimensional micellar nanostructures with a lipid core and a DNA corona. These hierarchical architectures are results of intermolecular hydrophobic interactions. Experimental testing further showed that these types of micelles have excellent thermal stability and their size can be fine-tuned by changing the length of the DNA sequence. Moreover, in the micelle system, the molecular recognition properties of DNA are intact, thus, our DNA micelles can hybridize with complimentary sequences while retaining their structural integrity. Importantly, when interacting with cell membranes, the highly charged DNA micelles are able to disintegrate themselves and insert into the cell membrane, completing the process of internalization by endocytosis. Interestingly, the fluorescence was found accumulated in confined regions of cytosole. Finally, we show that the kinetics of this internalization process is size-dependent. Therefore, cell permeability, combined with small sizes and natural nontoxicity are all excellent features that make our DNA-micelles highly suitable for a variety of applications in nanobiotechnology, cell biology, and drug delivery systems.
Collapse
Affiliation(s)
- Haipeng Liu
- Center for research at the Bio/Nano Interface, Department of Chemistry Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, USA, Fax: (+1) 352-846-2410
| | - Zhi Zhu
- Center for research at the Bio/Nano Interface, Department of Chemistry Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, USA, Fax: (+1) 352-846-2410
| | - Huaizhi Kang
- Center for research at the Bio/Nano Interface, Department of Chemistry Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, USA, Fax: (+1) 352-846-2410
| | - Yanrong Wu
- Center for research at the Bio/Nano Interface, Department of Chemistry Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, USA, Fax: (+1) 352-846-2410
| | - Kwame Sefan
- Center for research at the Bio/Nano Interface, Department of Chemistry Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, USA, Fax: (+1) 352-846-2410
| | - Weihong Tan
- Center for research at the Bio/Nano Interface, Department of Chemistry Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, USA, Fax: (+1) 352-846-2410
| |
Collapse
|