Browsing by Author "Pal, Robert"

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    Mechanical opening of lipid bilayers by molecular nanomachines
    (2023-01-31) Tour, James M.; Pal, Robert; García, López Victor; Nilewski, Lizanne; Rice University; William Marsh Rice University; Durham University; United States Patent and Trademark Office
    Embodiments of the present disclosure pertain to methods of opening a lipid bilayer by associating the lipid bilayer with a molecule that includes a moving component capable of moving (e.g., rotating) in response to an external stimulus; and exposing the molecule to an external stimulus before, during or after associating the molecule with the lipid bilayer. The exposing causes the moving component of the molecule to move and thereby open the lipid bilayer (e.g., by pore formation). The external stimuli may include an energy source, such as ultraviolet light. The opened lipid bilayer may be a component of cell membranes in vitro or in vivo. The opening of the lipid bilayer may allow for the passage of various materials (e.g., active agents, such as peptide-based drugs) through the lipid bilayer and into cells. Additional embodiments of the present disclosure pertain to the aforementioned molecules for opening lipid bilayers.
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    Mechanical opening of lipid bilayers by molecular nanomachines
    (2021-10-26) Tour, James M.; Pal, Robert; García-López, Victor; Nilewski, Lizanne; Rice University; Durham University; United States Patent and Trademark Office
    Embodiments of the present disclosure pertain to methods of opening a lipid bilayer by associating the lipid bilayer with a molecule that includes a moving component capable of moving (e.g., rotating) in response to an external stimulus; and exposing the molecule to an external stimulus before, during or after associating the molecule with the lipid bilayer. The exposing causes the moving component of the molecule to move and thereby open the lipid bilayer (e.g., by pore formation). The external stimuli may include an energy source, such as ultraviolet light. The opened lipid bilayer may be a component of cell membranes in vitro or in vivo. The opening of the lipid bilayer may allow for the passage of various materials (e.g., active agents, such as peptide-based drugs) through the lipid bilayer and into cells. Additional embodiments of the present disclosure pertain to the aforementioned molecules for opening lipid bilayers.
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    Molecular machines open cell membranes
    (Springer Nature, 2017) García-López, Víctor; Chen, Fang; Nilewski, Lizanne G.; Duret, Guillaume; Aliyan, Amir; Kolomeisky, Anatoly B.; Robinson, Jacob T.; Wang, Gufeng; Pal, Robert; Tour, James M.
    Beyond the more common chemical delivery strategies, several physical techniques are used to open the lipid bilayers of cellular membranes[1]. These include using electric[2] and magnetic[3] fields, temperature[4], ultrasound[5] or light[6] to introduce compounds into cells, to release molecular species from cells or to selectively induce programmed cell death (apoptosis) or uncontrolled cell death (necrosis). More recently, molecular motors and switches that can change their conformation in a controlled manner in response to external stimuli have been used to produce mechanical actions on tissue for biomedical applications[7,8,9]. Here we show that molecular machines can drill through cellular bilayers using their molecular-scale actuation, specifically nanomechanical action. Upon physical adsorption of the molecular motors onto lipid bilayers and subsequent activation of the motors using ultraviolet light, holes are drilled in the cell membranes. We designed molecular motors and complementary experimental protocols that use nanomechanical action to induce the diffusion of chemical species out of synthetic vesicles, to enhance the diffusion of traceable molecular machines into and within live cells, to induce necrosis and to introduce chemical species into live cells. We also show that, by using molecular machines that bear short peptide addends, nanomechanical action can selectively target specific cell-surface recognition sites. Beyond the in vitro applications demonstrated here, we expect that molecular machines could also be used in vivo, especially as their design progresses to allow two-photon, near-infrared and radio-frequency activation[10]