Abstract: The problem of lost circulation is pertinent to the oil industry. To prevent fluid loss, a lost circulation material (LCM), or more generally, a plugging material, can be used to effectively plug the fractures in the rock formation. If the fractures are in the production zone, it is also ideal to unplug them when the drilling operation is complete. Therefore, a material engineered to degrade after a desired period would be useful. In examples, a plugging material has been developed by gelling an oil-based fluid using a low molecular weight gelator, dibenzylidene sorbitol (DBS). DBS gels are robust and show plugging behavior. DBS is shown to chemically degrade in presence of an acid. Hence, a self-degrading gel can be synthesized by incorporating an acid into the system. Further, by varying the type and concentration of the acid, the degradation time of the gel can be controlled.

Abstract: Hydrogels are networks of polymer chains that are swollen in water. These gels can protect vulnerable objects (e.g., an egg or a fruit) if wrapped there around. Gels are constructed by either physical cross-linking (e.g., gelatin) or chemical cross-linking (e.g., acrylamide). The addition of starch granules to the above gels greatly enhances their protective abilities. When a load strikes a gelatin gel containing 20% starch, the peak impact force is reduced by 25% when compared to a bare gel without the starch. Correspondingly, the coefficient of restitution (COR) is also lowered by the presence of starch (e.g., a ball bounces less on a starch-bearing gel). The impact-absorbing effects of starch granules are correlated to their ability to shear-thicken water. When starch granules are gelatinized by heat, they no longer give rise to shear-thickening, and in turn, their protective ability in a gel is also eliminated.

Abstract: Electroadhesion, adhesion induced by an electric field, occurs between non-sticky cationic and anionic hydrogels. When gel and tissue are placed under an electric field, the pair strongly adhere, and the adhesion persists indefinitely thereafter. Applying a direct current (DC) field with reversed polarity elimi-nates the adhesion. The use of electroadhesion can seal cuts or tears in tissues or model anionic gels. In an example, electroadhesion works with the aorta, cornea, lung, and cartilage. In another example, electroadhered gel-patches provide a robust seal over openings in bovine aorta, and a gel sleeve is able to rejoin pieces of a severed gel tube.

Abstract: Methods of synthesizing multilayer structures, including multilayer capsules, tubes and hair-covered substrates, are provided. A substrate is provided comprising a polymerization initiator. The initiator-loaded substrate is exposed to a solution comprising a monomer and crosslinker. The initiator diffuses outwardly from the substrate, thereby initiating polymerization of the monomer and forming a layered structure comprising a polymer portion disposed on an exterior surface of the substrate. The process may be repeated for a selected number of cycles, thereby forming a multilayer structure having a selected number of layers. The composition, thickness and properties of each layer are selectively controlled. Multilayer structures formed in accordance with the methodologies are also provided.

Abstract: Methods and systems for synthesizing multicompartment capsules are disclosed, as well as multicompartment polymer capsules formed in accordance with disclosed techniques. At least one plurality of polymer capsules are formed via a capsule-forming process. A feed solution and a reservoir solution are provided, each comprising a biopolymer. The feed solution biopolymer and the reservoir solution biopolymer have opposite charges. Droplets of the feed solution are introduced into the reservoir solution, thereby forming via electrostatic complexation a plurality of polymer capsules. At least a portion of the resulting polymer capsules are then encapsulated in a larger polymer capsule via a similar process, wherein the feed solution utilized for the encapsulation process also comprises the formed smaller capsules.

Abstract: Surprisingly, electric fields can induce a dramatic response in soft materials made from nonconducting biopolymers. Capsules made from Alginate, Chitosan, and Gellan gum, all of which are charged polysaccharides and are biocompatible and biodegradable. Each capsule is formed by crosslinking biopolymer chains via physical (ionic/electrostatic) interactions. Under a DC electric field, the capsules rupture and disintegrate in a span of less than five minutes. The mechanism for the electroresponse is attributed to electrophoretic rearrangement of ions and/or polyelectrolyte chains in the capsule. Alginate capsules first swell anisotropically on their side closer to the anode (+ electrode). Cations migrate away from the anode, thereby lowering the crosslink density on that side. As further crosslinks are lost from the anode side, the capsule eventually breaks. A valve design utilizes an orifice that is blocked by a capsule and the valve is opened when the capsule is dislodged by the field.

Abstract: The problem of lost circulation is pertinent to the oil industry. To prevent fluid loss, a lost circulation material (LCM), or more generally, a plugging material, can be used to effectively plug the fractures in the rock formation. If the fractures are in the production zone, it is also ideal to unplug them when the drilling operation is complete. Therefore, a material engineered to degrade after a desired period would be useful. In examples, a plugging material has been developed by gelling an oil-based fluid using a low molecular weight gelator, dibenzylidene sorbitol (DBS). DBS gels are robust and show plugging behavior. DBS is shown to chemically degrade in presence of an acid. Hence, a self-degrading gel can be synthesized by incorporating an acid into the system. Further, by varying the type and concentration of the acid, the degradation time of the gel can be controlled.

Abstract: In various aspects and embodiments, the present invention provides hemostatic products and methods for treating wounds, including cavity wounds and non-compressible hemorrhage. In various embodiments, the invention employs hydrophobically-modified polymer foams, gels, or pastes.

Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.

Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.

Abstract: A method of system of forming a biopolymer hydrogel structure includes a mold loaded with a cation. At least a portion of the surface of the mold is exposed to a solution comprising a gellable polymer such as alginate. An electric potential is applied to the mold so that the cation therein and the gellable polymer migrate via electrophoresis toward the surface portion, thereby interacting and forming a hydrogel structure adjacent to the surface portion.

Abstract: Methods of synthesizing multilayer structures, including multilayer capsules, tubes and hair-covered substrates, are provided. A substrate is provided comprising a polymerization initiator. The initiator-loaded substrate is exposed to a solution comprising a monomer and crosslinker. The initiator diffuses outwardly from the substrate, thereby initiating polymerization of the monomer and forming a layered structure comprising a polymer portion disposed on an exterior surface of the substrate. The process may be repeated for a selected number of cycles, thereby forming a multilayer structure having a selected number of layers. The composition, thickness and properties of each layer are selectively controlled. Multilayer structures formed in accordance with the methodologies are also provided.

Abstract: Methods and systems for synthesizing multicompartment capsules are disclosed, as well as multicompartment polymer capsules formed in accordance with disclosed techniques. At least one plurality of polymer capsules are formed via a capsule-forming process. A feed solution and a reservoir solution are provided, each comprising a biopolymer. The feed solution biopolymer and the reservoir solution biopolymer have opposite charges. Droplets of the feed solution are introduced into the reservoir solution, thereby forming via electrostatic complexation a plurality of polymer capsules. At least a portion of the resulting polymer capsules are then encapsulated in a larger polymer capsule via a similar process, wherein the feed solution utilized for the encapsulation process also comprises the formed smaller capsules.

Abstract: A hemostatic putty for treatment of a variety of wounds topographies, including but not limited to highly three dimensional wounds, for example gunshot wounds and impalements, is disclosed. The putty is comprised of a matrix polymer weakly crosslinked or not crosslinked such that a viscoelastic matrix is formed. The viscoelastic nature of the putty is tunable by the composition and enables the putty to conform to a variety of wound topographies. Likewise, a hemostatic polymer, for example chitosan or hydrophobically modified chitosan, is included in this matrix to impart hemostatic properties and tissue adhesive on the putty. The hemostatic polymers disclosed prevent microbial infection and are suitable for oxygen transfer required during normal wound metabolism.

Abstract: A formulation for coating surfaces, for example gloves, with a tacky film comprises a hydrophobically modified biopolymer, where the hydrophobic modifications of the biopolymer correspond to between 1 and 90% of available functional groups, a plasticizer, and a volatile solvent. The formulation quickly dries into a tacky film that provides an enhanced friction of the surface.

Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.

Abstract: A hemostatic putty for treatment of a variety of wounds topographies, including but not limited to highly three dimensional wounds, for example gunshot wounds and impalements, is disclosed. The putty is comprised of a matrix polymer weakly crosslinked or not crosslinked such that a viscoelastic matrix is formed. The viscoelastic nature of the putty is tunable by the composition and enables the putty to conform to a variety of wound topographies. Likewise, a hemostatic polymer, for example chitosan or hydrophobically modified chitosan, is included in this matrix to impart hemostatic properties and tissue adhesive on the putty. The hemostatic polymers disclosed prevent microbial infection and are suitable for oxygen transfer required during normal wound metabolism.

Abstract: A sprayable polymeric foam hemostat for both compressible and non-compressible (intracavitary) acute wounds is disclosed. The foam comprises hydrophobically-modified polymers, such as hm-chitosan, or other amphiphilic polymers that anchor themselves within the membrane of cells in the vicinity of the wound. By rapidly expanding upon being released from a canister pressurized with liquefied gas propellant, the foam is able to enter injured body cavities and staunch bleeding. The seal created is strong enough to substantially prevent the loss of blood from these cavities. Hydrophobically-modified polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The amphiphilic polymers form solid gel networks with blood cells to create a physical clotting mechanism that prevent loss of blood.

Abstract: The present invention provides a novel biomaterial which is a hybrid, self-assembling biopolymeric networked film that is functionalized through hydrophobic interactions with vesicles loaded with bioactive agents. The biomaterial compound is a polymeric network of hydrophobically modified chitosan scaffolds that is taken from solution and formed as a solid film. This solid state film is capable of hydrophobic interactions with the functionalized vesicles. The vesicles include one or more lamellar structures forming one or more nano-compartments that are capable of containing similar or alternative active moieties within. Use of the film results in a degradation of the chitosan scaffold thereby releasing the active moieties within the vesicles from the scaffold. Application of the current invention occurs through various delivery mechanisms and routes of administration as will be described herein.

Abstract: A hemostatic putty for treatment of a variety of wounds topographies, including but not limited to highly three dimensional wounds, for example gunshot wounds and impalements, is disclosed. The putty is comprised of a matrix polymer weakly crosslinked or not crosslinked such that a viscoelastic matrix is formed. The viscoelastic nature of the putty is tunable by the composition and enables the putty to conform to a variety of wound topographies. Likewise, a hemostatic polymer, for example chitosan or hydrophobically modified chitosan, is included in this matrix to impart hemostatic properties and tissue adhesive on the putty. The hemostatic polymers disclosed prevent microbial infection and are suitable for oxygen transfer required during normal wound metabolism.