Commanding the Permeability and Stimuli-Responsive Characteristics of Vesicles/Polymersomes Composed of Dual-Cavity Baskets
Abstract
Project Abstract In line with great advances in controlling the structure and function of hierarchical self- assembled materials, there is still a need for developing hollow nanostructures that are (a) stable under extreme dilutions, (b) prone to easy functionalization (modular), (c) capable of operating in harsh environments and (d) responsive to stimuli in their immediate surrounding. Governing the morphology, encapsulation capacity and permeability of such nanostructures is essential for the construction of working nanoreactors and molecular delivery formulations. The ultimate goals center on mimicking the action of organelles and cells whereby compartmentalization and control of the trafficking of molecules are essential for managing a plethora of simultaneous, coupled and orthogonal chemical transformations. In this vein, we recently discovered that bolaamphiphilic and dual-cavity baskets, with six (S)-alanine groups at their periphery, assemble into stable unilamellar vesicles in water. The vesicular layer, composed of these hosts, can bind to complementary molecules to alter its permeability and thus allow for trapping fluorescent dyes in the reservoir of such vesicles. Can the hierarchical structure of these novel and stable vesicles, become stimuli-responsive to their immediate environment? Can they change their permeability when prompted with photochemical/chemical stimuli? Does it take a few complementary guest molecules to bind to the vesicular layer to have an amplified response in terms of the materialÕs structure, permeability and function? Can these vesicles be made into polymersomes for allowing their stimuli-responsive operation and function in harsh environments? In the light of our findings and current challenges toward understanding a control of molecular trafficking across vesicles/polymersomes, molecular amplification and the action of nanoreactors, we hereby propose a set of studies aimed toward addressing the above questions. Our aim is to develop fundamental science for facilitating design and preparation of functional hierarchical materials akin to those found in natural systems (cells and organelles) where compartmentalization and molecular trafficking play the critical role. The objectives of the proposed research are: (1) To learn about the trafficking of molecules as a function of their size and charge across the vesicular membrane composed of dual-cavity baskets possessing various amino acids at their periphery, (2) To develop stimuli-responsive vesicles capable of retaining their cargo for a prolonged period of time and its tunable release/uptake when prompted with photo or chemical stimuli, (3) To conjugate polymers and block-copolymers to dual-cavity baskets for obtaining dendritic polymersomes, having excellent thermodynamic stability yet with permeability being a function of small molecules present in their immediate environment for creating a new class of nanoreactors. To accomplish our objectives, we will use methods of organic synthesis to obtain a variety of amphiphilic molecules and then a combination of spectroscopy (emission, absorption and NMR), electron microscopy (TEM, SEM and Fluorescence microscopy) and computational chemistry (molecular dynamics) to study and optimize their characteristics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 16, 2018
- Source ID
- W911NF1710140
Entities
People
- Jovica D Badjić
Organizations
- Army Contracting Command
- Ohio State University
- United States Army