US-12623221-B2 - Object delivery systems and related methods

US12623221B2US 12623221 B2US12623221 B2US 12623221B2US-12623221-B2

Abstract

Embodiments include an object delivery system that may include a solute selected to diffuse through at least a portion of a porous material to a target and to associate with the target to form a source beacon capable of generating a solute outflux; and an object to be delivered to the target, wherein the solute outflux causes the object to migrate towards the target. Embodiments further include a method of using an object delivery system that may include one or more of the following steps: loading a target with a solute to form a source beacon, wherein the target is located within a porous material; releasing the solute from the source beacon to produce a solute outflux, wherein the solute outflux causes an object to migrate towards the target; and reloading the target with solute one or more times to form one or more additional source beacons.

Inventors

Todd Squires
Huanshu TAN

Assignees

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA

Dates

Publication Date: 20260512
Application Date: 20210915

Claims (6)

1 . A method of using an object delivery system, the method comprising: forming a first source beacon by loading a target within a porous material of the object delivery system with a first amount of solute; and producing a first solute outflux enabling an object to migrate towards the target by releasing at least a portion of the first amount of solute from the first source beacon.
2 . The method of claim 1 , wherein the forming the first source beacon includes associating the first amount of solute and the target by bringing a first solution including the first amount of solute in fluidic communication with the porous material.
3 . The method of claim 1 , wherein the producing the first solute outflux includes initiating the first solute outflux by removing permeated solute by convection from areas near the target by bringing a second solution including the object in fluidic communication with the porous material.
4 . The method of claim 1 , wherein the object is selected from the group consisting of a solid, a droplet, a bubble, a polymer, a colloid, an enzyme, a cell, a protein, a virus, a drug, an oil-liberating agent, a microcapsule, and a vesicle; or wherein the solute is selected from a salt, a surfactant, a polymer, an enzyme substrate, a dissolved gas, a solvent, and a molecule; or a combination thereof.
5 . The method of claim 1 , wherein the porous material is selected from the group consisting of an oil, a gas, a film, a coating, a living tissue, a brain tissue, a skin tissue, a polymeric material, a textile, a carpet, a fabric, a concrete, a cement, a grout, a drywall, a wood, a paper, a leaf, and hair.
6 . The method of claim 1 further comprising forming a plurality of source beacons by reloading the target with one or more additional amounts of solute one or more times.

Description

BACKGROUND Transporting colloidal objects to specific locations within porous media is important for many applications, including drug or cargo delivery, material fabrication, oil recovery, chemical and biochemical sensing, and remediation of polluted soils and waters. Even the delivery of small particles into porous environments remains highly challenging, however, since the low permeability of pore structures heterogeneously slows or even stops the passage of the fluids that suspend these colloids. For example, it is often difficult or impossible to force a fluid to flow into some areas within porous media, such as dead-end pores or small pores that require extremely high pressure to force a fluid through them. While delivery of particles to these and other areas may proceed by diffusion, the timescale required for the particles to diffuse to the desired area may be prohibitively long. For example, suspended colloids may traverse porous media via Brownian motion, this mechanism is impossibly slow in that micron-diameter particles may take about a month to diffuse even 1 millimeter. Even more challenging is that, in most cases, the specific location of targets is generally not known, and often cannot be determined from outside. SUMMARY According to one or more aspects of the invention, an object delivery system may include a solute selected to diffuse through at least a portion of a porous material to a target and to associate with the target to form a source beacon capable of generating a solute outflux; and an object to be delivered to the target, wherein the solute outflux causes the object to migrate towards the target. According to one or more aspects of the invention, a method of using an object delivery system may include one or more of the following steps: loading a target with a solute to form a source beacon, wherein the target is located within a porous material; releasing the solute from the source beacon to produce a solute outflux, wherein the solute outflux causes an object to migrate towards the target; and reloading the target with solute one or more times to form one or more additional source beacons. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart of a method of using an object delivery system, according to one or more embodiments of the invention. FIGS. 2A-2E is a schematic diagram of a system and method for targeted colloidal migration: (A) a micropore branches off from the main channel, where convective flows are applicable; there is a solute-favorable medium (e.g., a target) placed at the end of the micropore, where it is initially in an equilibrium state; (B) in a target loading step, solution is flowed through the main channel to create a diffusion influx of the solute towards the target, until (C) reaching a new equilibrium with a solute-saturated target in the micropore; (D) in a target releasing step, the solution in the main channel is replaced by flowing a colloidal suspension to build up a solute flux out of the micropore, after which (E) the solute-saturated target sustains the gradient of solute outfluxing, leading to a continuous colloidal movement towards the target such that the solute-favorable target becomes a beacon for the colloidal migration, according to one or more embodiments of the present disclosure. FIGS. 3A-3E illustrate an enhanced and prolonged colloidal migration towards a target: (A) a polyethylene glycol-diacrylate (PEG-DA) target was photopolymerized within a micropore and the colloidal streamlines along the main channel indicate no effective convection into the micropore; (B)-(E) are chronophotographic pictures of silicone oil droplets with color-coding to time display their locomotion in the first 10 min (color bar CB-1) and another 10 min after 3 hours (CB-2) by performing four different approaches: (B) solute-gradient-enhanced colloidal motion by the proposed strategy, i.e., preloading of 600 mM butanol solution to a target-placed micropore for 3 h; (C) solute-gradient-enhanced colloidal motion by preloading of 600 mM butanol solution to a micropore without a target for 3 h; (D) Brownian motion without a target; and (E) Brownian motion with a target, wherein the images in the far right column at 3 h highlight the enhanced and prolonged colloidal locomotions in (B), according to one or more embodiments of the present disclosure. FIGS. 4A-4F illustrate delivering colloids to a target hidden within a micro-channel branching network: (A) chronophotographic pictures of the network display the colloidal 15 min locomotion at 0, 5, and 10 h, demonstrating the colloidal delivery specifically to the target instead of the anti-target, where the zoom-in images at 10 h highlight the persistence of the targeted migration; (B) a schematic illustration of the network names the segments of the branching network for a diffusion simulation, where the partition coefficient (P) is P=10 for the target, and P=0.5 for the anti-target; (C) a simulation snapshot of t