Compounds, Compositions, and Methods for Delivering Biologically Active Agents

Abstract

The present disclosure relates to lyotropic liquid crystal lipid carriers useful for the delivery of active agents. The present disclosure also relates to cosmetic or pharmaceutical compositions comprising the lipid carriers, and methods of using the lipid carriers or compositions thereof for treating, preventing, or diagnosing diseases, disorders, or conditions such as cancer or bacterial or fungal infections.

Description

Technical Field

[0001] Cross - reference to related applications This application claims priority from Australian Provisional Patent Application No. 2022 / 901069, filed on April 22, 2022, the content of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to the field of nanomedicine. Specifically, the present disclosure relates to lipid carriers or nanoparticles for delivering biologically active agents. Disclosed herein are carriers such as nanoparticles containing synthetic lipids, methods for their preparation, and the use of nanoparticles for the formulation and delivery of pharmaceutical or cosmetic agents.

Background Art

[0003] Any reference to background art herein should not be construed as an admission that such technology constitutes common general knowledge in Australia or elsewhere.

[0004] Pharmaceutical and cosmetic agents can be difficult to deliver due to low solubility in aqueous media, low cell permeability, chemical and / or biological instability, rapid enzymatic and metabolic degradation, and elimination from the body, among other reasons, along with low safety and tolerability. Many of such biologically active agents would be safer and more effective if they could be selectively administered. For example, chemotherapeutic drugs are often highly toxic to both cancer cells and normal cells, and in most cases, there is no method to bias systemic delivery to cancer cells in order to reduce off - target effects.

[0005] There are different strategies to overcome issues related to the delivery of biologically active agents, such as new dosage forms, alternative forms of the drug (salts / complexes), prodrugs or other conjugates of the drug, or alternative routes of administration. Further examples include the development of nanodelivery systems such as liposomes, polymeric micelles, microemulsions and self-emulsifying drug delivery systems, nanodispersions, inorganic nanoparticles, solid lipid nanoparticles, inclusion complexes, and nanodelivery systems based on chemical conjugation. The development of these technologies and their application to a wider range of biologically active agents continues to progress.

[0006] There is a need to provide additional carriers for delivering pharmaceutical and cosmetic agents, as well as other biologically active agents such as nucleic acids. There is a further need to develop new carriers that enable preferential delivery of biologically active agents to disease or infection sites. Such carriers would be useful for disease treatment and diagnosis, as well as for the formulation of pharmaceuticals and personal care products.

Summary of the Invention

[0007] The present disclosure provides compounds, compositions, and methods that are useful in any biological system where it may be desirable to deliver a material that is protected or otherwise separated from the system until certain conditions are present.

[0008] Specifically, the present disclosure provides compounds, compositions, and methods for improving the delivery of biologically active agents. In particular, this application provides compounds, compositions, and methods for making and using novel delivery agents that are stable in circulation and can undergo a structural change under appropriate physiological conditions (e.g., pH) that allow for control of the efficiency of delivery of biologically active agents.

[0009] The compounds, compositions, and methods provided by the present disclosure are stable in circulation at ambient pH and undergo a structural change under appropriate physiological conditions (e.g., reduced pH) that increase the release of the active agent in a local environment having these physiological conditions, thereby facilitating the effective delivery of the active agent. By providing an active agent encapsulated in a lipid carrier that undergoes a structural change under such local environments having a reduced pH, examples of such local environments include tumors, sites affected by certain bacterial and fungal infections, and subcellular organelles.

[0010] Non-limiting examples of active agents that can be delivered using the compounds, compositions, and methods of the present disclosure include hydrophilic and lipophilic agents, including therapeutically or cosmetically active molecules, small molecule drugs, peptides, proteins, hormones, vitamins, antibodies, oligonucleotides, siRNA, DNA, mRNA, and contrast agents.

[0011] By utilizing the structural phase change in the lipid carrier under appropriate physiological conditions (e.g., reduced pH), the release of the encapsulated active agent from the lipid carrier can be controlled and engineered for targeted delivery of the active agent, improving efficacy and reducing off-target side effects of the active agent.

[0012] In a first aspect, there is provided a lyotropic liquid crystal (LLC) lipid carrier comprising a structural lipid that is a lyotropic liquid crystal-forming lipid and an amino lipid having an amide linker, the LLC lipid carrier being adapted to undergo a mesophase transition when exposed to a decrease in pH.

[0013] In embodiments, the structural lipid can form a cubic mesophase structure. In embodiments, the structural lipid optionally comprises a hydrophobic tail group selected from the group consisting of oleyl, linoleoyl, linolenoyl, phytanoyl, farnesoyl, or extended aliphatic hydrophobic substances, optionally selected from oleyl, linoleoyl, and phytanoyl. In embodiments, the structural lipid is monoolein (glycerol monooleate).

[0014] In an embodiment, the amino lipid is present in weight % of the total lipid content of the LLC lipid carrier, which is suitable for bringing about a mesophase transition when exposed to a decrease in pH. In an embodiment, the amino lipid accounts for about 5 wt% to about 50 wt% of the total lipid content of the LLC lipid carrier.

[0015] In an embodiment, the amino lipid has the formula (I): Cyc-L-R (I), [wherein Cyc is a nitrogen heterocycle or heteroaryl, L is an amide linker, R is a C10-C44 carbon chain].

[0016] In an embodiment, the amino lipid has the formula (Ib):

Chemical formula

[0017] In an embodiment, R is selected from the group consisting of oleyl, linoleoyl, linolenoyl, phytanoyl, and farnesoyl.

[0018] In an embodiment, the amino lipid is

Chemical formula

[0019] In an embodiment, the LLC lipid carrier further comprises a stabilizer, and optionally, the stabilizer is a stabilizing polymer, optionally a nonionic triblock copolymer. In an embodiment, the stabilizer is present in an amount of about 10 wt% of the total lipid content of the LLC lipid carrier. The stabilizer is Pluronic F127 (Poloxamer407) or Poloxamer80.

[0020] In an embodiment, the LLC lipid carrier is in the form of lyotropic liquid crystal (LLC) nanoparticles.

[0021] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is a transition caused by a decrease in pH to less than pH 7.

[0022] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is a transition caused by a decrease in pH of 1 to 4 pH units.

[0023] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is a transition to an intermediate phase with a lower interfacial curvature than the intermediate phase occupied by the lipid carrier before the pH decrease.

[0024] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is a transition to an intermediate phase corresponding to a lower CPP value.

[0025] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is a transition from a hexagonal phase to a cubic phase.

[0026] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is L 2 →H 2 →Q 2 →L 3 a transition from one intermediate phase to another intermediate phase following the intermediate phase transition order of. In an embodiment, the intermediate phase transition is H 2 →Q 2 .

[0027] In an embodiment, the LLC lipid carrier comprises a hexagonal lyotropic liquid crystal phase structure at a pH of about 7 or higher, optionally about 7.4 or higher.

[0028] In an embodiment, the LLC lipid carrier comprises a cubic lyotropic liquid crystal phase structure at a pH of about 4.0 to pH 7.0.

[0029] In an embodiment, the LLC lipid carrier comprises a hexagonal lyotropic liquid crystal phase structure at a pH of about 7 or higher, optionally about 7.4 or higher, and a cubic lyotropic liquid crystal phase structure at a pH of about 4.0 to pH 7.0.

[0030] In an embodiment, the LLC lipid carrier further comprises an active agent, and optionally, the active agent is pharmaceutically or cosmetically active. In an embodiment, the active agent is selected from the group consisting of peptides, proteins, enzymes, small molecule drugs, and nucleic acids, and optionally, the active agent is selected from the group consisting of radionuclides, contrast agents, polymers, antibiotics, fungicides, metal-containing nanoparticles, anti-inflammatory agents, anti-tumor agents, cardiovascular agents, anti-anxiety agents, hormones, growth factors, steroid agents, gene expression modifiers, knockdown agents, siRNA, RNAi agents, mRNA, DNA, dicer substrates, miRNA, shRNA, antisense oligonucleotides, aptamers, and microbial-derived toxins. In an embodiment, the active agent is a topoisomerase I inhibitor optionally selected from camptothecin, irinotecan, and SN-38.

[0031] In an embodiment, the LLC lipid carrier has a water content of about 20 to about 60% by weight.

[0032] In a second aspect, there is provided a lyotropic liquid crystal (LLC) lipid nanoparticle composition which is a dispersion of the LLC lipid carrier of the first aspect in a polar medium.

[0033] In a third aspect, there is provided a cosmetic composition comprising the LLC lipid carrier of the first aspect, or the LLC lipid nanoparticle composition of the second aspect, and a cosmetically acceptable carrier, diluent, and / or excipient.

[0034] In a fourth aspect, there is provided a pharmaceutical composition comprising the LLC lipid carrier of the first aspect, or the LLC lipid nanoparticle composition of the second aspect, and a pharmaceutically acceptable carrier, diluent, and / or excipient.

[0035] In an embodiment, the cosmetic composition of the third aspect, or the pharmaceutical composition of the fourth aspect, is formulated as a composition for injection, topical administration, or subcutaneous administration.

[0036] In a fifth aspect, there is provided a method of delivering an active agent to a biological system, the method comprising administering to the biological system the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect.

[0037] In an embodiment, the delivery of the active agent in the biological system is altered by the response of the LLC lipid carrier to a predetermined pH range. In an embodiment, the response includes an intermediate phase transition of the LLC lipid carrier, and optionally, the phase transition is a transition from the hexagonal phase structure to the cubic phase structure of the LLC lipid carrier. In an embodiment, the intermediate phase transition occurs at a pH of about pH 7.0 to pH 4.0, optionally about pH 7.0 to pH 5.5. In an embodiment, the response results in the preferential release of the active agent in a predetermined pH range in the biological system.

[0038] In a sixth aspect, there is provided a method for controlled release of an active agent, the method comprising forming the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect, and administering the LLC lipid carrier, the LLC lipid nanoparticle composition, or the composition to a biological system comprising a target region having a predetermined pH, thereby achieving preferential release of the active agent in the target region.

[0039] In an embodiment, the LLC lipid carrier undergoes an intermediate phase transition in response to a predetermined pH. In an embodiment, the intermediate phase transition is a transition from the hexagonal phase structure to the cubic phase structure of the LLC lipid carrier.

[0040] In a seventh aspect, there is provided a method of treating or preventing a disease, disorder, or condition in a mammal, the method comprising administering to the mammal a therapeutically effective amount of the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect.

[0041] In an eighth aspect, there is provided the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect for use in the treatment or prevention of a disease, disorder, or condition.

[0042] In a ninth aspect, there is provided the use of the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect in the manufacture of a medicament for the treatment of a disease, disorder, or condition.

[0043] In embodiments, the disease, disorder, or condition is cancer or a bacterial or fungal infection.

[0044] In a tenth aspect, there is provided a method of diagnosing a disease, disorder, or condition in a mammal, the method comprising administering to the mammal or a biological sample obtained from the mammal the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect, wherein the active agent is a labeled active agent, to facilitate diagnosis of the disease, disorder, or condition in the mammal.

[0045] In embodiments, the disease, disorder, or condition is cancer or a bacterial or fungal infection.

[0046] In an eleventh aspect, formula (Ib):

Chemical formula

[0047] In an embodiment, Cyc is selected from the group consisting of pyridyl, pyrimidinyl, piperidinyl, piperazinyl, and pyrazinyl.

[0048] In an embodiment, R is selected from the group consisting of oleoyl, linoleoyl, linolenoyl, phytanoyl, and farnesoyl.

[0049] In an embodiment, the amino lipid is

Chemical formula

[0050] The various features and embodiments of the present invention mentioned in the previous individual sections are applied mutatis mutandis to other sections as necessary. Accordingly, the features specified in one section may be combined with the features specified in other sections as necessary.

[0051] Further features and advantages of the present invention will become apparent from the following detailed description.

Brief Description of the Drawings

[0052] Although it is understood that various embodiments disclosed herein may be utilized, several examples will be described hereinbelow with reference to the following drawings.

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs.

[0054] Unless otherwise stated, all publications discussed and / or referenced herein are hereby incorporated by reference in their entirety.

[0055] Unless required by context otherwise, singular terms shall include pluralities and plural terms shall include singulars. Throughout this disclosure, unless otherwise specified or required by context otherwise, references to a single step, composition, group of steps, or group of compositions shall include one and pluralities (i.e., one or more) of these steps, compositions, groups of steps, or groups of compositions. Accordingly, as used herein, the singular terms “a,” “an,” and “the” include plural aspects unless clearly indicated otherwise by context. For example, references to “a” include two or more as well as a single one, references to “an” include two or more as well as a single one, references to “the” include two or more as well as a single one, and so on.

[0056] One of ordinary skill in the art will appreciate that the disclosure herein is susceptible to variations and modifications other than those specifically described. It is intended that the disclosure include all such variations and modifications. The disclosure also includes all of the examples, steps, features, methods, compositions, formulations, and processes individually or collectively recited or shown herein, as well as any and all combinations or any two or more of such steps or features.

[0057] The term “and / or,” e.g., “X and / or Y,” shall be understood to mean either “X and Y” or “X or Y” and shall be construed to explicitly support both meanings or either meaning.

[0058] Unless otherwise indicated, terms such as “first,” “second,” etc. are used herein merely as a classification and are not intended to impose sequential, positional, or hierarchical requirements on the items they refer to. Further, references to a “second” item do not require or preclude the existence of a lower numbered item (e.g., a “first” item) and / or a higher numbered item (e.g., a “third” item).

[0059] As used herein, the phrases "at least one of" or "one or more of", when used in conjunction with a list of items, mean that different combinations of one or more of the listed items can be used, and that only one of the items in the list may be required. The items can be specific objects, things, or categories. In other words, "at least one of" means that any combination or number of items can be used from the list, but not all of the items in the list may be required. For example, "at least one of item A, item B, and item C" can mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, "at least one of item A, item B, and item C" can mean, for example but not limited to, 2 of item A, 1 of item B, and 10 of item C; 4 of item B, and 7 of item C; or some other suitable combination.

[0060] It should be understood that certain features described herein in the context of separate embodiments for clarity may be provided in combination in a single embodiment. Conversely, various features described in the context of a single embodiment for brevity may also be provided separately or in any sub - combination.

[0061] Throughout this specification, various aspects and components of the present disclosure can be presented in a range format. The range format is included for convenience and should not be construed as an inflexible limitation on the scope of the present disclosure. Accordingly, a range description should be considered to specifically disclose all possible sub-ranges and individual numerical values within that range, unless specifically indicated otherwise. For example, a range description such as 1 to 5 should be considered to specifically disclose sub-ranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 5, 3 to 5, etc., as well as individual and partial numbers within the listed range, such as 1, 2, 3, 4, 5, 5.5, and 6, unless an integer is required or implicit from the context. This applies regardless of the width of the disclosed range. If specific values are required, these will be indicated in the specification.

[0062] In this patent specification, the terms "comprises", "comprising", "includes", "including", or similar terms are intended to mean non-exclusive inclusion, such that a method or composition that includes a list of elements can include other elements not listed in addition to these elements.

[0063] "Consisting of" means including and limited to all that follows the phrase "consisting of". Accordingly, the phrase "consisting of" indicates that the listed elements are necessary or essential and that no other elements can be present.

[0064] "Consisting essentially of" means including any elements listed after the phrase and limited to other elements that do not interfere with or contribute to the activity or action specified in the disclosure for the listed elements. Accordingly, the phrase "consisting essentially of" indicates that the listed elements are necessary or essential, but that other elements may optionally be present, depending on whether they affect the activity or action of the listed elements.

[0065] Unless otherwise indicated herein, the term "about" includes a 10% tolerance in any value or values connected with the term.

[0066] As used herein, "weight %" may be abbreviated as "wt%" or "wt. %".

[0067] "Pharmaceutical composition" or "pharmaceutical preparation" refers to a composition suitable for pharmaceutical use in subjects including humans and mammals. A pharmaceutical composition includes a pharmacologically effective amount of the composition used by the methods described herein, and also includes a pharmaceutically acceptable carrier. A pharmaceutical composition includes a composition comprising the active ingredient and the inactive ingredients that constitute the carrier, such as excipients, as well as any combination, complexation or aggregation of any two or more ingredients, and / or dissociation of one or more ingredients, and / or any product directly or indirectly resulting from other types of reactions or interactions of one or more ingredients. Thus, the pharmaceutical compositions of the present invention include any composition prepared by mixing the composition used by the methods described herein with a pharmaceutically acceptable carrier.

[0068] Unless otherwise defined, "pharmaceutically acceptable carrier" or simply "carrier" refers to any of standard pharmaceutical carriers, buffers, and excipients. A pharmaceutically acceptable carrier can be physiological saline, such as phosphate buffered saline, or a 5% aqueous dextrose solution. Further examples of pharmaceutically acceptable carriers include, but are not limited to, emulsions such as oil / water or water / oil emulsions, and various types of wetting agents and / or adjuvants. Suitable pharmaceutical carriers and formulations are described in Remington’s Pharmaceutical Sciences, 19th Ed. (Mack Publishing Co., Easton, 1995). Preferred pharmaceutical carriers depend on the intended mode of administration of the active agent. Exemplary modes of administration include enteral (e.g., oral) or parenteral (e.g., subcutaneous, intramuscular, intravenous or intraperitoneal injection; or topical, transdermal, or transmucosal administration).

[0069] As used herein, the term "pharmaceutically acceptable salt" refers to salts of active agents that are toxicologically safe for systemic or topical administration, such as salts prepared from pharmaceutically acceptable non-toxic bases or acids, including inorganic or organic bases and inorganic or organic acids. Pharmaceutically acceptable salts can be selected from the group including alkali and alkaline earth metals, ammonium, aluminum, iron, amines, glucosamine, chlorides, sulfates, sulfonates, bisulfates, nitrates, citrates, tartrates, bitartrates, phosphates, carbonates, bicarbonates, malates, maleates, napsylates, fumarates, succinates, acetates, benzoates, terephthalates, palmitates, piperazines, pectates, and S-methylmethionine salts, among others.

[0070] As used herein, the term "cosmetic composition" refers to a composition used in cosmetics. Cosmetics are products intended to be rubbed, poured, sprinkled, sprayed, introduced, or otherwise applied to the human body for cleansing, beautifying, promoting attractiveness, or altering appearance. Typically, cosmetic compositions do not provide a therapeutic effect and are not formulated as pharmaceuticals. However, in some situations, cosmetic compositions are incorporated into pharmaceuticals to provide cosmetic benefits (e.g., treating the condition of the skin or hair). The present disclosure also contemplates the use of cosmetics in animals other than humans.

[0071] As used herein, "cosmetically acceptable" indicates that a particular component or excipient is generally considered to be safe and non-toxic at the levels used.

[0072] As used herein, the term "complex" is understood to mean a non-covalent physical interaction between two or more chemical substances.

[0073] As used herein, the terms "non-lamellar lyotropic liquid crystal phase" and "lyotropic liquid crystal (LLC) lipid carrier" refer to self-organizing non-lamellar liquid crystal phases formed from at least one amphiphilic substance that provide two-dimensional and / or three-dimensional mesophase structures capable of carrying an active agent. Dispersed non-lamellar lyotropic liquid crystal phase particles are presented herein to provide pH-responsive structural behavior. The term non-lamellar refers to a lyotropic liquid crystal phase or lipid carrier or particle that is not a liposome (or L α phase), i.e., does not exhibit a planar structure consisting of lipid bilayers separated by water, and the polar head groups of the amphiphilic molecules are in direct association and contact with water while the hydrophobic tails are away from the water. A liquid crystal phase is a substance that exhibits a phase of a material having properties intermediate between those of a conventional liquid phase and a solid crystal phase, as described herein. There are different types of liquid crystal phases, and these can be distinguished based on their different optical properties and other properties known in the art.

[0074] In embodiments, the LLC lipid carriers of the present invention contain only liquid crystals. That is, the LLC lipid carriers of the present invention do not contain any solid lipid components. Thus, the LLC lipid carriers of the present invention are not solid lipid nanoparticles (SLNs) or nanostructured lipid carriers (NLCs).

[0075] In embodiments, the term "non-lamellar lyotropic liquid crystal phase" or "lyotropic liquid crystal phase" encompasses only cubic, hexagonal, and sponge morphologies. "Sponge phase" or "sponge particles" (L 3 ) are recognized as having no long-range order and exhibiting an equivalent crystal periodicity to the inverse bicontinuous cubic phase (Q 2 ), although these are often "melted" Q 2A cubic phase is contemplated and thus considered to be included as the particles of the first or second aspect. Thus, the short-range order sponge phase is explicitly contemplated to be within the scope of this term. In embodiments, the term "non-lamellar lyotropic liquid crystal phase" or "lyotropic liquid crystal phase" includes hexagonal (normal and inverse), cubic (normal discrete, inverse discrete, inverse bicontinuous (including primitive, gyroidal, and rhombohedral), and inverse discontinuous), and other "mesophases" including ribbon, mesh, or non-cubic "sponge" bicontinuous phases, and may be used to include one or more phases selected from the group consisting of.

[0076] Amino lipid In a first aspect, the present disclosure provides a lyotropic liquid crystal (LLC) lipid carrier comprising a structural lipid that is a lyotropic liquid crystal phase-forming lipid and an amino lipid having an amide linker, wherein the LLC lipid carrier is adapted to undergo a mesophase transition when exposed to a decrease in pH.

[0077] In embodiments, the amino lipid has the formula (I): Cyc-L-R (I), [wherein Cyc is a nitrogen heterocycle or heteroaryl, L is an amide linker, and R is a C10-C44 carbon chain].

[0078] As used herein, the term "amino lipid" refers to an amphiphilic lipid compound containing a functional group containing a nitrogen atom, preferably a head group containing a nitrogen atom. In embodiments, the lipid compound contains a basic ionizable functional group such as an amine or a nitrogen-containing aromatic ring. In embodiments, the amino lipids disclosed herein are ionizable and / or cationic lipids. In embodiments, the amino lipid provides pH sensitivity to the LLC lipid carriers disclosed herein. In any of the embodiments disclosed herein, a lipid may be referred to as an "amino lipid" based on the presence of at least one nitrogen atom.

[0079] In the embodiments disclosed herein, the amino lipid generally includes a polar hydrophilic head group containing a nitrogen heterocycle or heteroaryl, and a non-polar hydrophobic tail group containing a C10-C44 carbon chain. In embodiments, the amino lipid in the LLC lipid carrier disclosed herein may generally include one or more cationic and / or ionizable head groups.

[0080] In embodiments, the nitrogen heterocycle or heteroaryl is, for example, piperidinyl, piperazinyl, pyrrolinyl, pyrrolidinyl, pyrazolidinyl, morpholinyl, imidazolinyl, imidazolidinyl, pyrrolinyl, pyrazolinyl, thiazolidinyl, thiomorpholinyl, tetrahydropyridyl, dihydropyridyl, tetrahydropyridinidinyl, pyrimidinyl, pyridyl, pyrrolyl, imidazolyl, pyrazolyl, oxazolyl, oxadiazolyl, pyrazinyl, tetrazolyl, thiazolyl, isoxazolyl, isothiazolyl, isoxazololonyl, triazolyl, oxadiazolyl, thiadiazolyl, or a 5- or 6-membered nitrogen heterocyclyl or heteroaryl such as a pyridazinyl group. In certain preferred embodiments, the nitrogen heterocycle or heteroaryl is selected from pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholinyl, and pyrazinyl. Preferably, the nitrogen heterocycle or heteroaryl is pyridyl or piperidinyl.

[0081] In embodiments, the amino lipid in the LLC lipid carrier disclosed herein may include a cationic ionizable amino head group bonded (e.g., covalently) to a non-polar hydrophobic tail group via an amide linker and containing a C10-C44 carbon chain.

[0082] As used herein, the term "amide linker" refers to a linker containing an amide group, such as an alkyl chain interrupted by an amide group.

[0083] In embodiments, the amide linker contains an optional carbon chain between the nitrogen heterocycle or heteroaryl and the amide group. In embodiments, the optional carbon chain contains from 1 to 6 carbon atoms, or from 1 to 5 carbon atoms, or from 1 to 4 carbon atoms, or from 1 to 3 carbon atoms, or from 1 to 2 carbon atoms, or 1 carbon atom, preferably from 1 to 4 carbon atoms.

[0084] In embodiments, when present, the carbon chain is optionally interrupted by one or more heteroatoms. In embodiments, each interrupting heteroatom can be independently selected from O, N, and S.

[0085] In embodiments, the nonpolar hydrophobic tail group contains a C10-C44 carbon chain. The carbon chain can be a linear or branched alkyl, alkenyl, or alkynyl chain. In certain embodiments, the tail group contains a C10-C36 alkyl, alkenyl, or alkynyl chain, a C12-C24 alkyl, alkenyl, or alkynyl chain, preferably a C12-C24 alkyl or alkenyl. In certain preferred embodiments, the tail group contains a C12-C18 alkyl, alkenyl or alkynyl chain, preferably a C12-C18 alkyl or alkenyl chain, preferably a C12-C18 alkenyl chain.

[0086] For example, the nonpolar hydrophobic tail group can contain oleyl, linoleoyl, linolenoyl, phytanoyl, and farnesoyl groups, preferably oleyl or linoleoyl, preferably oleyl group.

[0087] In some embodiments, the LLC lipid carriers disclosed herein have the formula (Ib):

Chemical formula

[0088] In embodiments, the Cyc group is a 6-membered nitrogen heterocycle or heteroaryl. In some embodiments, Cyc is selected from the group consisting of pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, tetrahydropyridyl, dihydropyridyl, tetrahydropyrimidinyl, pyrazinyl, and pyridazinyl. Preferably, Cyc is selected from the group consisting of pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholinyl, and pyrazinyl.

[0089] In any of the embodiments disclosed herein, the R group of the amino lipid can be selected from hydrophobic chains that follow the design rules of the inverse bicontinuous cubic phase. The selection of the R group hydrophobic chain can be made based on certain requirements understood in the art. For example, the hydrophobic chain can be selected from those that promote a type II lyotropic liquid crystal phase at ambient and physiological temperatures. Parameters that can be appropriate for the selection of a suitable hydrophobic chain include: 1. The use temperature should be above the chain melting temperature such that a molten chain is present; and 2. At least one cis unsaturated bond in a carbon chain of at least 14 carbons should be present at at least an intermediate position along the backbone; or 3. The carbon backbone should contain at least 12 carbons, three of which are secondary carbons having a methyl branch; and 4. The molecular weight of the hydrophobic chain should be greater than at least 200 amu.

[0090] In embodiments, the R group of the amino lipid is C12-C24 alkenyl, preferably C14-C22 alkenyl.

[0091] In embodiments, the R group is selected from the group consisting of oleoyl, linoleoyl, linolenoyl, phytanoyl, and farnesoyl. In some embodiments, the R group is oleoyl. In some embodiments, R is

Chemical formula

[0092] In embodiments, the R group can be selected from lipid tails known to form cationic or ionizable cationic lipids when used with a polar head group. For example, the following lipids are known to form lipid nanoparticles (LNPs) for nucleic acid delivery. The lipid tails of these lipids, and lipid tails in this structural class, can be suitable for use as the R group as defined herein.

Chemical formula

[0093] In embodiments, the amino lipid in the LLC lipid carrier disclosed herein is

Chemical formula

[0094] In some embodiments, the amino lipid is

Chemical formula

[0095] In another aspect, the present disclosure provides a compound of formula (Ib):

Chemical formula

[0096] In an embodiment, Cyc is selected from the group consisting of pyridyl, pyrimidinyl, piperidinyl, piperazinyl, and pyrazinyl.

[0097] In an embodiment, R is selected from the group consisting of oleyl, linoleoyl, linolenoyl, phytanoyl, and farnesoyl.

[0098] In an embodiment, the amino lipid is

Chemical formula

[0099] In an embodiment, the amino lipid is

Chemical formula

[0100] The amino lipids described herein can be synthesized by any suitable method known to those skilled in the relevant art.

[0101] For example, the amino lipid can be synthesized using an amide coupling reaction between a suitable carboxylic acid or its derivative bearing a hydrophobic tail group and an amine bearing a hydrophilic head group. Alternatively, the amino lipid can be synthesized using an amide coupling reaction between a suitable carboxylic acid or its derivative bearing a hydrophilic head group and an amine bearing a hydrophobic tail group. The conditions for the amide coupling reaction are well known in the art.

[0102] Rhotropic liquid crystal (LLC) lipid carrier According to a first aspect, there is provided a rhotropic liquid crystal (LLC) lipid carrier comprising a structural lipid that is a rhotropic liquid crystal phase-forming lipid and an amino lipid having an amide linker, the LLC lipid carrier being adapted to undergo a mesophase transition when exposed to a decrease in pH.

[0103] Rhotropic liquid crystal (LLC) materials are generally composed of amphiphilic substances that self-assemble into various mesophase structures in a polar medium (e.g., an aqueous solution or water). Generally, the present disclosure relates to non-lamellar-forming mesophases that can consist of well-defined networks of aqueous channels and lipid bilayer membranes, such as bicontinuous cubic or inverse hexagonal mesophases. As used herein, the terms "mesophase," "rhotropic phase," "liquid crystal phase," "rhotropic liquid crystal phase," or simply "phase" are used interchangeably. Non-lamellar mesophases can be applied as drug carriers either as the bulk phase or as fabricated colloidal nanocarriers, such as cubosomes and hexosomes.

[0104] As used herein, the terms "amphiphilic substance," "amphiphilic," and "amphiphilic lipid" refer to a compound that includes both a hydrophilic portion and a hydrophobic portion. Typically, such compounds have a hydrophilic head group and a hydrophobic tail. Suitable examples include fatty acids and various lipid molecules. In an aqueous solution, amphiphilic substances spontaneously form a structure that hides the hydrophobic portion but allows the hydrophilic head group to be hydrated.

[0105] As used herein, the term "lyotropic liquid crystal" material refers to a material having fluid properties similar to those of a viscous liquid and a degree of molecular order similar to that of a crystalline solid. The LLC lipid carriers of the present disclosure may have some or all of the components of a lyotropic liquid crystal (LLC) phase. In embodiments, the LLC lipid carriers disclosed herein are at least 90% in a lyotropic liquid crystal (LLC) phase. In some embodiments, the LLC lipid carriers disclosed herein do not contain any solid crystalline components.

[0106] Lyotropic phases are characterized in the art by the amount of curvature they exhibit. For example, when an amphiphilic monolayer is curved towards the aqueous phase, the lyotropic phase is called an inverse phase. In contrast, when the monolayer is curved away from the aqueous phase, the lyotropic phase is called a normal phase.

[0107] The LLC lipid carriers disclosed herein can be in the form of an LLC bulk phase. Bulk phase LLC materials are viscous gel-like materials. The present disclosure generally relates to inverse bicontinuous cubic (Q 2 ), inverse hexagonal (H 2 ), or inverse micellar cubic (I 2 ) phases, etc., of non-lamellar bulk self-assembled mesophases that can be formed depending on the complex interplay between the molecular shape of the amphiphilic substance, the total free energy of the lipid-aqueous system, and environmental conditions.

[0108] The bulk phase LLC materials disclosed herein can be dispersed in an aqueous solution to generate LLC nanoparticles such as cubosomes and hexasomes. Thus, in embodiments, the LLC lipid carriers disclosed herein are in the form of LLC nanoparticles.

[0109] In contrast to conventional lipid carriers such as solid lipid nanoparticles (SLN) or nanostructured lipid carriers (NLC), the lipid carriers disclosed herein are lyotropic liquid crystal (LLC) lipid carriers in which the amphiphilic substances retain fluid properties. As a result, the lyotropic liquid crystal (LLC) lipid carriers disclosed herein can advantageously undergo a mesophase transition, for example, upon exposure to a change in pH (e.g., a decrease in pH).

[0110] For example, the prior art SLN described by Mhule et al. (Int. J. Pharm., 2018, 550, 149 - 159) are solid lipid nanoparticles that contain crystallized amino lipids as the sole lipid component in addition to a surfactant and the drug vancomycin.

[0111] The LLC materials disclosed herein are typically formed under excess water conditions, which makes them particularly suitable for drug delivery applications. For example, the LLC lipid carriers of the present disclosure can contain water in an amount of from about 0.1 wt% to about 90 wt%, from about 0.1 wt% to about 85 wt%, from about 0.1 wt% to about 80 wt%, from about 0.1 wt% to about 75 wt%, from about 0.1 wt% to about 70 wt%, from about 0.1 wt% to about 65 wt%, from about 0.1 wt% to about 60 wt%, from about 0.1 wt% to 55 wt%, from about 0.1 wt% to about 50 wt%, from about 0.1 wt% to about 45 wt%, from about 0.1 wt% to about 40 wt%, from about 0.1 wt% to about 35 wt%, from about 0.1 wt% to about 30 wt%, from about 0.1 wt% to about 25 wt%, from about 0.1 wt% to about 20 wt%, from about 0.1 wt% to about 15 wt%, from about 0.1 wt% to about 10 wt%, from about 0.1 wt% to about 5 wt%, from about 0.1 wt% to about 4 wt%, from about 0.1 wt% to about 3 wt%, from about 0.1 wt% to about 2 wt%, or from about 0.1 wt% to about 1 wt%.

[0112] In embodiments, the LLC lipid carriers of the present disclosure contain water in an amount of at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt%. In embodiments, the LLC lipid carriers of the present disclosure contain water in an amount of at least 0.1 wt%, at least 0.5 wt%, at least 1 wt%, at least 2.5 wt%, at least 3 wt%, at least 3.5 wt%, at least 4 wt%, at least 4.5 wt%, or at least 5 wt%.

[0113] In embodiments, the LLC lipid carriers disclosed herein contain water in an amount of about 1 wt% to about 10 wt%, about 5 wt% to about 15 wt%, about 10 wt% to about 20 wt%, about 15 wt% to about 25 wt%, about 20 wt% to about 30 wt%, about 25 wt% to about 35 wt%, about 30 wt% to about 40 wt%, about 35 wt% to about 45 wt%, about 40 wt% to about 50 wt%, about 45 wt% to about 55 wt%, about 50 wt% to about 60 wt%, about 55 wt% to about 65 wt%, about 60 wt% to about 70 wt%, about 65 wt% to about 75 wt%, or about 70 wt% to about 80 wt%. In some embodiments, the LLC lipid carriers disclosed herein contain water in an amount of about 10 wt% to about 60 wt%, about 20 wt% to about 60 wt%, about 30 wt% to about 60 wt%, about 40 wt% to about 60 wt%, or about 50 wt% to about 60 wt%. In some embodiments, the LLC lipid carriers disclosed herein contain water in an amount of about 40 wt% to about 50 wt%.

[0114] The LLC lipid carriers disclosed herein are formed from at least one structural lipid that is a lyotropic liquid crystal phase-forming lipid, in addition to an amino lipid having an amide linker. In any embodiment herein, the at least one structural lipid is amphiphilic.

[0115] At least one structural lipid is selected from amphiphilic lipids known in the art and can form a lyotropic liquid crystal phase, particularly a cubic and / or mesophase structure, such as cubosomes and / or hexasomes. In an embodiment, the structural lipid can form a cubic mesophase structure, such as a cubosome.

[0116] The selection of a suitable at least one structural lipid can be made based on certain requirements understood in the art. For example, the lipid can be selected from those that adopt a type II lyotropic liquid crystal phase at ambient and physiological temperatures. Parameters that can be appropriate for the selection of a suitable lipid include: (i) for the hydrophobic component, 1. the temperature should be above the chain melting temperature such that melted chains are present; and 2. at least one cis unsaturated bond in a carbon chain of at least 14 carbons should be present at least midway along the backbone; or 3. the carbon backbone should contain at least 12 carbons, three of which are secondary carbons having methyl branches; and 4. the molecular weight of the hydrophobic substance should be greater than at least 200 amu, and (ii) with respect to the head group, 5. the head group should contain at least three functional groups (e.g., hydroxyl) having a minimum hydrophilicity; 6. the head group should be able to form a hydrogen bonding network of head group-water; and 7. the head group region should be small relative to the hydrophobic footprint. By way of example, this is exemplified by the MO lipid used in the examples of the present disclosure by meeting criteria 1, 2, and 4 for the hydrophobic substance and criteria 5, 6, and 7 for the head group. It will be understood that many other lipids that appropriately meet these criteria are available and can be selected based on these criteria which are known or readily ascertainable values.

[0117] Guidance regarding the selection of at least one structural lipid can be found in one or more of the following publications, each of which is hereby incorporated by reference in its entirety: (i) T. Kaasgaard and C. J. Drummond, “Ordered 2D and 3D Nanostructured Amphiphile Self-Assembly Materials Stable in Excess Solvent,” Phys. Chem. Chem. Phys. 2006, 8, 4957-4975. (ii) C. Fong, T. Le and C. J. Drummond, “Lyotropic Liquid Crystal Engineering - Ordered Nanostructured Small Molecule Amphiphile Self-Assembly Materials by Design,” Chem. Soc. Rev., 2012, 41, 1297-1322 DOI: 10.1039 / c1cs15148g; (iii) L. van ‘t Hag, S. L. Gras, C. E. Conn and C. J. Drummond, “Lyotropic liquid crystal engineering moving beyond binary compositional space - Ordered nanostructured amphiphile self-assembly materials by design,” Chem. Soc. Rev., 2017, 46, 2705-2731. DOI: 10.1039 / c6cs00663a; and (iv) S. Sarkar, N. Tran, Md H. Rashid, T. C. Le, I. Yarovsky, C. E. Conn and C. J. Drummond, “Toward cell membrane biomimetic lipidic cubic phases: a high-throughput exploration of lipid compositional space,” ACS Applied Biomaterials, 2019, 2, 182-195. DOI: 10.1021 / acsabm.8b00539.

[0118] Polyhydroxyl (glycolipids) and polyethers (polyethylene oxide) form two of the largest categories of type II that can form the head groups of interest. Non-limiting examples of head group motifs include alcohol, fatty acid, monoacylglycerol, MAG, 2-MAG, glycerate, glyceryl ether, ethylene oxide, amide, monoethanolamide, diethanolamide, serinolamide, methylpropanediolamide, ethylpropanediolamide, urea, urea alcohol, biuret, biuret alcohol, ureido, endocannabinoids (anandamide, virodhamine, 2-glycerol, dopamine, 2-glycerol ether), and glycolipids. Examples include phospholipids such as DMPC and DMPE.

[0119] In an embodiment, at least one structural lipid can be selected from the group consisting of ethylene oxide, monoacylglycerol, glycolipids, phosphatidylethanolamine, and urea-based amphiphilic substances, and derivatives or analogs thereof.

[0120] Ethylene oxide amphiphilic substances may include C12(EO)2, C12(EO)4, C12(EO)5 and C12(EO)6, as well as dialkyl ethylene oxide amphiphilic substances. Monoacylglycerols may include monomyristolein, monoolein, monobacsenin, and monoelsin. Amphiphilic substances similar to monoacylglycerols may be appropriate, including oleyl glycerate, phytanyl glycerate, glyceryl monooleyl ether, glyceryl phytanyl ether, phytantriol, and monononadecenoin. Glycolipids having a glycolipid moiety that may be appropriate, including monosubstituted glycolipids: β-Mal3(Phyt)2, β-Glc(Phyt), β-Xyl(Phyt), β-Glc-(TMO)2, β-Mal2(Phyt)2 and β-Glc(Phyt)2; and disubstituted unbranched glycolipids: 1,2-diacyl-(β-D-glucopyranosyl)-sn-glycerol; 1,2-dialkyl-(β-D-glucopyranosyl)-sn-glycerol; 1,3-diacyl-(β-D-glucopyranosyl)-sn-glycerol; 1,3-dialkyl-(β-D-glucopyranosyl)-sn-glycerol. Phosphatidylethanolamine amphiphilic substances may include dioleoyl phosphatidylcholine (DOPC) and dioleoyl phosphatidylethanolamine (DOPE). Urea amphiphilic substances may include dodecyl urea (DU), octadecyl urea (ODU), oleyl urea (OU), oleyl biuret (OBU), linoleyl urea (LU), phytanyl urea (PU), hexahydrofarnesyl urea (HFU).

[0121] In an embodiment, at least one structural lipid can be selected from the group consisting of 1-monoolein, 2-monoolein, citrem, oleoyl lactate, oleamide, monoelaidin, linoleic acid, elaidic acid, monopalmitolein, monolinolein, phytantriol, diolein, triolein, dioleoyl glycerol, didodecyldimethylammonium bromide, dioctadecyl(dimethyl)ammonium chloride (DOAC / DODMAC) or bromide (DODAB), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dioleoyl phosphatidylglycerol (DOPG), oleic acid, lysophosphatidylcholine 1-hydroxy-2-oleoyl-sn-glycero-3, 1,2-dioleoyl-sn-glycero-3-dihexylphosphocholine, vitamin E tocopherol, vitamin E (tocopheryl) acetate, phytanoyl monoethanolamide, farnesoyl monoethanolamide, oleoyl monoethanolamide, linoleoyl monoethanolamide, and linolenoyl monoethanolamide.

[0122] The single-chain amphiphilic lipid can be selected from the group consisting of saturated fatty acids C7-C16, oleic acid, elaidic acid, linoleic acid, sodium oleate / gadolinium oleate, oleamide, 1-glyceryl monooleyl ether (GME), GMO, 2-MO, oleoyl lactate, citrem, diglycerol monooleate (DGMO), lysophosphatidylcholine (1-oleoyl), (Z)-octadec-9-enyl ferrocene, N-dodecylcaprolactam (C12), vitamin K1, ubiquinone-10 (coenzyme Q10), vitamin E, vitamin E acetate, vitamin A palmitate, alpha-tocopheryl PEO1000 succinate (vitamin E TPGS), PEG2000-MO, PEG-PT, PEOx-stearate (x = 40-100), polysorbate 80.

[0123] Amphiphilic lipids having multiple alkyl chains can be selected from the group consisting of didecyldimethylammonium bromide (DDAB); di(canola ethyl ester)dimethylammonium chloride (DEEDAC); dioctadecyl(dimethyl)ammonium chloride (DOAC / DODMAC) or bromide (DODAB); diolein; dioleoyl glycerol (DOG), EDTA-bioleoyl; EDTA-biphytanyl; 1,2-dioleoyl-3-trimethylammonium propane (DOTAP); 1,2-dioleoyl phosphatidic acid (DOPA); 1,2-dioleoyl phosphatidylglycerol (DOPG), 1,2-distearoyl phosphatidylglycerol (DSPG); 1,2-dioleoyl phosphatidylethanolamine (DOPE), 1,2-distearoyl glycero-3-phosphoethanolamine (DSPE); 1,2-dioleoyl phosphatidylcholine (DOPC); 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC); 1,2-dioleoyl-sn-glycero-3-phosphoserine (DOPS); 1,2-dipalmitoyl phosphatidylserine (DPPS); DSPE-mPEG350, 750, 2000 (X = 7, 16, or 45); DSPE-PEG2000, 3400, 5000; DMPE-mPEG550; (C18)2DTPA(Gd), cardiolipin, cyclodextrin derivatives (βCD-nC10).

[0124] In any embodiment herein, at least one structural lipid can be monoolein and / or phytantriol.

[0125] In any embodiment herein, the lipid carrier of the present disclosure can include MO or phytantriol in combination with one or more of cholesterol, DLPC, DSPC, DPPE, DPPS, DOPS, DPPC, DMPC, DMPS, and DLPS.

[0126] Monoacylglycerols are known to form inverse phases over large regions of their phase diagrams, with monoolein being the most prominent. The formation of inverse phases is advantageous due to the kink introduced by the cis double bond. Longer acyl chains increase the volume of the hydrophobic chains, making monoolein more wedge-shaped and shifting the spectrum of the mesophase to the type 2 phase. When the double bond is closer to the end of the lipid, the effect is thereby reduced, which results in fewer wedge shapes. The elongation of the acyl chain is expected to further shift the mesophase formation towards the type 2 phase, and based on this, it is not surprising that the H 2 phase becomes the dominant phase with such a change.

[0127] In embodiments where the LLC lipid carrier comprises at least two structural amphiphilic lipids, then at least one can be selected from monoolein and phytantriol.

[0128] In such embodiments, at least one structural lipid of monoolein and / or phytantriol can be combined, individually or in combination, with one or more of triolein, vitamin E, and DOPE. If it is desired to impart a charge to the lipid carrier, these combinations themselves are well-known in the art, commercially available, and can be further combined with one or more cationic lipids selected from those containing a wide variety of quaternary ammonium cationic compounds.

[0129] Certain ones of the at least one structural lipid can be selected, in particular, due to their effect on the internal curvature of the final lipid particles, for example, DOPE.

[0130] Representative cationic lipids can be selected from the following non-limiting examples: 3-β[4N(1N8-diguanyidinospemidine)-carbamoyl]cholesterol (BGSC); 3-β[N,N-diguanidinoethylaminoethane)carbamoyl]cholesterol (BGTC); N,N1,N2,N3-tetramethyltetrapalmityl spermine (Selfectin); NtN’-butyl-N’-tetradecyl-3-tetradecyl-amino-propion-amidine (CLONfectin) dimethyldioctadecylammonium bromide (DDAB); 1,2-myristoxypropyl-3-dimethylhydroxyethylammonium bromide (DMRIE); 2,3-dioleoyloxy-N-[2(sperminecarboxamide)ethyl]-N,N-dimethyl-1-p-ropana (nitrotri fluoroacetate) (DOSPA); 1,3-dioleoyloxy-2-(6-carboxyspermil)propylamide (DOSPER); 4-(2,3-bis-palmitoyloxypropyl)-1-methyl-1H-imidazole (DPIM); N,N,N’,N’-tetramethyl-N,N’-bis(2-hydroxyethyl)-2,3-dioleoyloxy-1,4-butane, diammonium iodide (Tfx-50); N-1-(2,3-dioleoyloxy)propyl-N,N,N-trimethylammonium chloride (DOTMA) or other N-(N,N-1-dialkoxy)alkyl-N,N,N-trisubstituted ammonium surfactants; the trimethylammonium group is a cholesterol group (in the case of ChOTB) DORI (DL-1,2-dioleoyl-3-dimethylaminopropyl-β-hydroxyethylammonium) or DORIE (DL-1,2-O-dioleoyl-3-dimethylaminopropyl) (B-hydroxyethylammonium) (DORIE) disclosed in WO93 / 03709, or a butanol spacer arm 1,2-dioleoyl-3-(4’-trimethylammonio)butanol-sn-glycerol (DOBT) or cholesteryl (4’-trimethylammonia) butanoate (ChOTB) connected to a similar body to form a double strand (DOT); 1,2-dioleoyl-3-succinyl-sn-glycerol choline ester (DOSC);Tetraoctylammonium bromide (TOAB) as a cationic phase transfer agent; cholesteryl hemisuccinate ester (ChOSC); midonglycyl spermine (DOGS) and dipalmitoyl phosphatidylethanolamine spermine (DPPES) or the cationic lipids disclosed in U.S. Patent No. 5,283,185, cholesteryl-3β-carboxamidoethyltrimethylammonium chloride, 1-dimethylamino-3-trimethylammonio-DL-2-propyl cholesteryl carboxylate iodide, cholesteryl-3-O-carboxamidoethylamine, cholesteryl-3-β-oxysuccinamide-ethyltrimethylammonium iodide, 1-dimethylamino-3-trimethylammonio-DL-2-propyl cholesteryl-3-β-oxysuccinate iodide, 2-(2-trimethylammonio)ethylmethylaminoethyl alcohol, teryl-3-β-oxysuccinate iodide, 3-β-N-(N’,N’-dimethylaminoethane)carbamoyl cholesterol (DC-chol), and 3-β-N-(polyethyleneimine)carbamoyl cholesterol; O,O-dimyristyl-N-lysyl aspartate (DMKE); O,O-dimyristyl-N-lysyl glutamate (DMKD): 1,2-dimyristyloxypropyl-3-dimethylhydroxyethylammonium bromide (DMRIE); 1,2-dilauroyl-sn-glycero-3-ethylphosphocholine (DLEPC); 1,2-dimyristyl-sn-glycero-3-ethylphosphocholine (DMEPC); 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (DOEPC); 1,2-dipalmitoyl-sn-glycero-3-ethylphosphocholine (DPEPC); 1,2-distearoyl-sn-glycero-3-ethylphosphocholine (DSEPC); 1,2-dioleoyl-3-trimethylammonium propane (DOTAP); dioleoyldimethylaminopropane (DODAP); 1,2-palmitoyl-3-trimethylammonium propane (DPTAP); 1,2-distearoyl-3-trimethylammonium propane (DSTAP); 1,2-myristoyl-3-trimethylammonium propane (DMTAP); and sodium dodecyl sulfate (SDS).;

[0131] In an embodiment, particularly preferred cationic lipids are DOTAP and / or DODAB and / or tetraoctylammonium bromide (TOAB).

[0132] In an embodiment, the lipid carrier may contain a fatty acid in addition to at least one structural lipid such as oleic acid.

[0133] In a further embodiment, suitable amphiphilic lipids include, but are not limited to, lipid compounds containing a hydrophobic tail group selected from the group consisting of oleoyl, linoleoyl, linolenoyl, phytanoyl, farnesoyl, or an extended aliphatic hydrophobic tail. In certain embodiments, the structural lipid compound contains an oleoyl, linoleoyl, or phytanoyl hydrophobic tail, preferably an oleoyl tail.

[0134] Generally, any amphiphilic lipid typically used to form cubic phase nanoparticles can be used as the structural lipid.

[0135] In embodiments, one or more structural amphiphilic lipids can be selected from the group consisting of monoolein (also known as glycerol monooleate), citrem, oleoyl lactate, oleamide, monoelaidin, linoleic acid, elaidic acid, monopalmitolein, monolinolein, phytantriol, diolein, triolein, dioleoyl glycerol, didodecyldimethylammonium bromide, dioctadecyl(dimethyl)ammonium chloride (DOAC / DODMAC) or bromide (DODAB), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dioleoyl-phosphatidylglycerol (DOPG), oleic acid, lysophosphatidylcholine 1-hydroxy-2-oleoyl-sn-glycero-3, 1,2-dioleoyl-sn-glycero-3-dihexylphosphocholine, vitamin E tocopherol, vitamin E (tocopheryl) acetate, phytanoyl monoethanolamide, farnesoyl monoethanolamide, oleoyl monoethanolamide, linoleoyl monoethanolamide, and linolenoyl monoethanolamide.

[0136] In a preferred embodiment, the structural amphiphilic lipid is monoolein.

[0137] In embodiments, the LLC lipid carrier is a non-lamellar lyotropic liquid crystal phase such as a self-assembled non-lamellar lyotropic liquid crystal phase. In embodiments, the non-lamellar lyotropic liquid crystal phase is formed by the self-assembly of one or more amphiphilic lipids. Suitable amphiphilic lipids are understood to self-assemble in the presence of an aqueous solution such as water or an aqueous buffer solution to form a lyotropic liquid crystal structure exhibiting a non-lamellar mesophase. In embodiments, the non-lamellar lyotropic liquid crystal phase is an inverse bicontinuous cubic phase (Q 2 ), inverse hexagonal phase (H 2 ), or inverse micellar cubic phase (I 2 ) mesophase having the structure.

[0138] The bulk lyotropic liquid crystal phase can be dispersed to form nanoparticles. When dispersed in an aqueous solution, these nanoparticles retain their internal nanostructure and are called cubosomes, hexasomes, and micelle cubosomes.

[0139] Thus, in some embodiments, the LLC lipid carriers disclosed herein are in the form of nanoparticles such as lipid nanoparticles (LNPs). Such nanoparticles may be referred to as lyotropic liquid crystal (LLC) lipid nanoparticles or lyotropic liquid crystal lipid nanoparticles (LCNPs). The terms "nanoparticle," "LLC lipid nanoparticle," "LNP," and "LCNP" are used interchangeably herein.

[0140] Nanoparticles can be formed by dispersing a bulk non-lamellar lyotropic liquid crystal phase in a colloidal system. When dispersed, for example, in an aqueous solution, nanoparticles such as cubosomes, hexasomes, and micelle cubosomes are produced.

[0141] The LLC lipid carriers of the present invention may preferably contain at least one stabilizer selected from those known in the art. Suitable stabilizers can assist in the dispersion of the non-lamellar lyotropic liquid crystal phase and / or can assist in retaining the nanostructure of the nanoparticles.

[0142] In embodiments, the stabilizer can be a Poloxamer, a surfactant, or a PEGylated lipid stabilizer, or a modified version thereof.

[0143] In an embodiment, the stabilizer is selected from a PEG-PPO-PEG triblock copolymer, a nonionic block copolymer surfactant, and PEO copolymerized with a charged moiety. Poloxamer 407 and Pluronic 127 can be suitable examples of stabilizers and can be incorporated into any of the embodiments of the first or second aspect described herein. PEO copolymerized with (3-acrylamidopropyl) trimethylammonium chloride, or a similar charge-carrying moiety, can also be suitable. PEGylated lipid stabilizers including PEG2000-MO, PEG-PT, DSPE-PEG(2000) amine, 18:0PEG2000PE, and DSPE-PEG(5000) amine are suitable but not limited thereto. Many other such stabilizers are known in the art.

[0144] The use of a stabilizer is preferred and the properties of the stabilizer can be selected based on the properties of the lipid, but the selection and understanding of the compatibility of these components may be based on information known in the art.

[0145] Many steric stabilizers reported to date can be divided into four groups: (i) amphiphilic block copolymers (i.e., Poloxamer™), (ii) PEGylated lipids, (iii) customized lipid copolymers, and (iv) alternative steric stabilizers (e.g., bile salts, proteins). Ideally, the stabilizer selected prevents aggregation of the particles by forming an electrostatic or more generally a steric barrier between approaching particles. Stabilizers that can function optimally in the lipid particles of the present disclosure share similar properties, including (i) that they are generally very hydrophilic with high HLB (hydrophilic-lipophilic balance) values due to their asymmetric amphiphilic polymer structures having larger hydrophilic domains. It is important that the hydrophilic portion of the molecule is not surrounded by a hydrophobic region. High HLB can be achieved by the use of longer PEG chains or multiple PEG chains, (ii) the presence of hydrogen bond acceptors and the absence of hydrogen bond donors, and (iii) electrical neutrality. One of ordinary skill in the art can select a suitable stabilizer based on this. Further, the following academic papers address major aspects of stabilizers that may be suitable for use with the lipid carriers of the present disclosure, and all of them are incorporated herein by reference in their entirety: (i) J.Y.T. Chong, X. Mulet, B.J. Boyd and C.J. Drummond; “Steric Stabilizers for Cubic Phase Lyotropic Liquid Crystal Nanodispersions (Cubosomes)” in “Advances in Planar Lipid Bilayers and Liposomes”, Vol 21, Chp 5, (2015) p.131-187, ISSN1554-4516, Elsevier; (ii) J. Zhai, B. Fan, S.H. Thang, C.J. Drummond “Novel amphiphilic block copolymers for the formation of stimuli-responsive non-lamellar lipid nanoparticles” Molecules, 2021, 26, 3648-3664. DOI:10.3390 / molecules26123648; (iii) J. Zhai, R.Suryadinata, B. Luan, N. Tran, T. M. Hinton, J. Ratcliffe, X. Hao and C. J. Drummond “Amphiphilic brush polymers produced by the RAFT polymerisation method stabilise and reduce the cell toxicity of lipid lyotropic liquid crystalline nanoparticles” Faraday Discussions, 2016, 191, 545 - 563. DOI: 10.1039 / C6FD00039H; Faraday Discussion 191 on Nanoparticles with Morphological and Functional Anisotropy; (iv) J. Zhai, T. J. Hinton, L. J. Waddington, C. Fong, N. Tran, X. Mulet, C. J Drummond and B. W. Muir”Lipid-PEG Conjugates Sterically Stabilise and Reduce the Toxicity of Phytantriol-Based Lyotropic Liquid Crystalline Nanoparticles” Langmuir, 2015, 31, 10871 - 10880. DOI: 10.1021 / acs.langmuir.5b02797; (v) J. Y. T. Chong, X. Mulet, D. Keddie, L. J. Waddington, S. T. Mudie, B. J. Boyd and C. J. Drummond “Novel Steric Stabilisers for Lyotropic Liquid Crystalline Nanoparticles: Pegylated Phytanyl Copolymers” Langmuir, 2015, 31, 2615 - 2629. DOI: 10.1021 / la501471z; (vi) J. Y. T. Chong, X. Mulet, A. Postma, D. J. Keddie, L. J. Waddington, B. J. Boyd and C. J.Drummond, "Novel RAFT Amphiphile Brush Copolymer Steric Stabilisers for Cubosomes: Poly(octadecyl acrylate)-block-poly(polyethylene glycol methyl ether acrylate)", Soft Matter, 2014, 10, 6666 - 6676. DOI: 10.1039 / C4SM01064G; (vii) A. Tilley, C. J. Drummond and B. J. Boyd, "Disposition and Association of the Steric Stabiliser Pluronic F127 in Lyotropic Liquid Crystalline Nanostructured Particle Dispersions", J. Colloid and Interface Science, 2013, 392, 288 - 296. DOI: 10.1016 / j.jcis.2012.09.051 (viii) J. Y. T. Chong, X. Mulet, L. J. Waddington, B. J. Boyd and C. J. Drummond, "High Throughput Discovery of Novel Steric Stabilisers for Cubic Lyotropic Liquid Crystal Nanoparticle Dispersions", Langmuir, 2012, 28, 9223 - 9232. DOI: 10.1021 / la301874v; (ix) J. Y. T. Chong, X. Mulet, L. J. Waddington, B. J. Boyd and C. J. Drummond, "Steric Stabilisation of Cubic Lyotropic Liquid Crystalline Nanoparticles: High Throughput Evaluation of Triblock Polyethylene Oxide-Polypropylene Oxide-Polyethylene Oxide Copolymers.", Soft Matter, 2011, 7, 4768 - 4777. DOI: 10.1039 / c1sm05181d.

[0146] A stabilizer may be present during the formation of the LLC lipid nanoparticles disclosed herein.

[0147] Certain preferred stabilizers include stabilizing polymers such as nonionic triblock copolymers. In certain embodiments, the stabilizer is Pluronic F127 (also known as Poloxamer407) or Poloxamer80, preferably Pluronic F127.

[0148] The LLC lipid carriers disclosed herein can be prepared by mixing the amino lipids and the structural lipids disclosed herein. For example, the amino lipids and the structural lipids may be mixed as a solution in an organic solvent, followed by evaporation of the solvent. Preferably, at least the stabilizer is also mixed with these lipid components.

[0149] A mixture of two or more structural lipids may be used as the structural lipid. Similarly, two or more amino lipids may be used to form the lipid carriers of the present disclosure.

[0150] Various weight ratios of amino lipids and structural lipids can be used. These can be useful in determining the exact pH at which the desired structural transition occurs. The preferred weight ratio of amino lipid to structural lipid or total lipid in the lipid carrier can simply be determined by trying multiple ratios and determining the one that is optimal for the pH environment under consideration. Such an approach is described in the experimental section. Thus, in embodiments, the weight ratio of amino lipid to structural lipid or total lipid in the lipid carrier can be one that results in a mesophase transition when the pH decreases to a pre-determined pH value.

[0151] In an embodiment, the structural lipid may constitute most of the lipid carrier or may be used in a proportion equal to that of the amino lipid. In an embodiment, the ratio of the structural lipid to the lipid having an amide linker such as an amino lipid is 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, 10:90, 5:95% by weight, preferably 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 60:40, 50:50, 40:60, 30:70% by weight, preferably 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 60:40, 50:50% by weight. In an embodiment, the corresponding weight fraction of the amino lipid is 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, preferably 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4 and 0.5, 0.6, 0.7, preferably 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4 and 0.5.

[0152] In an embodiment, the amino lipid having an amide linker is present in a weight fraction of 0.1 to 0.7 of the total amount of lipids in the lipid carrier.

[0153] In an embodiment, the amino lipid having an amide linker is present in a weight fraction of 0.1 to 0.6, or 0.2 to 0.6, or 0.1 to 0.55, or 0.2 to 0.55 of the total amount of lipids in the lipid carrier.

[0154] In a certain preferred embodiment, the weight fraction of the amino lipid is 0.2 to 0.6, preferably 0.3 to 0.5, preferably 0.4 to 0.5.

[0155] In any of the embodiments described herein, the amino lipid may be present in weight % of the total lipid content of the LLC lipid carrier, which is suitable for bringing about a mesophase transition when exposed to a decrease in pH. For example, the amino lipid may account for about 5 wt% to about 50 wt% of the total lipid content of the LLC lipid carrier disclosed herein. The LLC lipid carrier may contain an amount of amino lipid that is more than about 5%, more than about 10%, more than about 15%, more than about 20%, more than about 25%, more than about 30%, more than about 35%, more than about 40%, more than about 45%, more than about 50%, more than about 55%, more than about 60%, more than about 65%, more than about 70%, more than about 75%, or more than about 80% of the total lipid content of the LLC lipid carrier. In an embodiment, the amino lipid may contain from about 0.5 wt% to about 50 wt% of the total lipid content of the LLC lipid carrier disclosed herein, for example, from about 0.5 wt% to about 40 wt%, from about 1 wt% to about 35 wt%, from about 1.5 wt% to about 30 wt%, from about 2 wt% to about 25 wt%, from about 2.5 wt% to about 20 wt%, from about 3 wt% to about 15 wt%, from about 3.5 wt% to about 10 wt%, or from about 4 wt% to 9 wt%. In one embodiment, the amino lipid contains about 40 wt% of the total lipid content of the LLC lipid carrier disclosed herein.

[0156] To prepare the LLC lipid nanoparticles disclosed herein, a mixture of amino lipid and structural lipid may be dispersed in an aqueous solution. For example, the aqueous solution may be water, a buffer, or another aqueous solution. The aqueous solution may also contain a stabilizer. Suitable stabilizers include the stabilizers described above. In an embodiment, the stabilizer may be a Poloxamer, a surfactant, or a PEGylated lipid stabilizer, or a modified version thereof. Preferred stabilizers include, but are not limited to, Pluronic F127 or Poloxamer80.

[0157] The LLC lipid nanoparticles of the present disclosure can contain water in an amount of about 0.1 wt% to about 90 wt%, about 0.1 wt% to about 85 wt%, about 0.1 wt% to about 80 wt%, about 0.1 wt% to about 75 wt%, about 0.1 wt% to about 70 wt%, about 0.1 wt% to about 65 wt%, about 0.1 wt% to about 60 wt%, about 0.1 wt% to 55 wt%, about 0.1 wt% to about 50 wt%, about 0.1 wt% to about 45 wt%, about 0.1 wt% to about 40 wt%, about 0.1 wt% to about 35 wt%, about 0.1 wt% to about 30 wt%, about 0.1 wt% to about 25 wt%, about 0.1 wt% to about 20 wt%, about 0.1 wt% to about 15 wt%, about 0.1 wt% to about 10 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 4 wt%, about 0.1 wt% to about 3 wt%, about 0.1 wt% to about 2 wt%, or about 0.1 wt% to about 1 wt%.

[0158] In embodiments, the LLC lipid nanoparticles disclosed herein contain water in an amount of at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt%. In embodiments, the LLC lipid nanoparticles of the present disclosure contain water in an amount of at least 0.1 wt%, at least 0.5 wt%, at least 1 wt%, at least 2.5 wt%, at least 3 wt%, at least 3.5 wt%, at least 4 wt%, at least 4.5 wt%, or at least 5 wt%.

[0159] In embodiments, the LLC lipid nanoparticles disclosed herein contain water in an amount of about 1 wt% to about 10 wt%, about 5 wt% to about 15 wt%, about 10 wt% to about 20 wt%, about 15 wt% to about 25 wt%, about 20 wt% to about 30 wt%, about 25 wt% to about 35 wt%, about 30 wt% to about 40 wt%, about 35 wt% to about 45 wt%, about 40 wt% to about 50 wt%, about 45 wt% to about 55 wt%, about 50 wt% to about 60 wt%, about 55 wt% to about 65 wt%, about 60 wt% to about 70 wt%, about 65 wt% to about 75 wt%, or about 70 wt% to about 80 wt%. In some embodiments, the LLC lipid nanoparticles disclosed herein contain water in an amount of about 10 wt% to about 60 wt%, about 20 wt% to about 60 wt%, about 30 wt% to about 60 wt%, about 40 wt% to about 60 wt%, or about 50 wt% to about 60 wt%. In some embodiments, the LLC lipid nanoparticles disclosed herein contain water in an amount of about 40 wt% to about 50 wt%.

[0160] The LLC lipid nanoparticles of the present disclosure can be provided as a nanoparticle dispersion in a polar medium such as an aqueous medium. Thus, in a second aspect, there is provided a lyotropic liquid crystal (LLC) lipid nanoparticle composition which is a dispersion of the LLC lipid carriers disclosed herein in a polar medium, such as an aqueous dispersion of the LLC lipid carriers disclosed herein. The term "polar medium" is to be understood to mean polar media including, but not limited to, water, glycerol, propylene glycol, propylene carbonate, methanol, ethanol, glycol formal, etc., and solutions based on these liquids, and mixtures thereof. For example, the polar medium can be water or an aqueous buffer. Generally, the LLC lipid nanoparticle compositions disclosed herein can include solvents or dispersion media including, but not limited to, water, ethanol, polyols (e.g., glycerol, propylene glycol, liquid polyethylene glycol, etc.), lipids (e.g., triglycerides, vegetable oils, and injectable organic esters such as ethyl oleate), and combinations thereof. In some cases, it may be preferred to include an isotonic agent such as, for example, sugar, sodium chloride, or a combination thereof.

[0161] In some embodiments, the LLC lipid nanoparticle compositions disclosed herein are formed by dispersing the LLC lipid carriers disclosed herein in a pharmaceutically or cosmetically acceptable carrier or diluent including, but not limited to, water or any solvent, dispersion medium, coating, surfactant, antioxidant, preservative (e.g., antibacterial, antifungal agents), isotonic agent, absorption delaying agent, salt, preservative, drug, drug stabilizer, gel, binder, excipient, disintegrant, lubricant, sweetening agent, flavoring agent, dye, and similar materials and combinations thereof known to those skilled in the art (Remington’s, 1990). Use in therapeutic, pharmaceutical, and cosmetic compositions is contemplated provided any conventional pharmaceutically or cosmetically acceptable carrier is not incompatible with the active ingredient. The compositions used in the present disclosure may contain different types of carriers depending on whether it is to be administered in solid, liquid, or aerosol form and whether it needs to be sterile for an administration route such as injection.

[0162] In embodiments, the amount of polar medium (e.g., water) in the LLC lipid nanoparticle composition disclosed herein is at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, at least about 40 wt%, at least about 45 wt%, at least about 50 wt%, at least about 55 wt%, at least about 60 wt%, at least about 65 wt%, at least about 70 wt%, at least about 75 wt%, at least about 80 wt%, at least about 85 wt%, at least about 90 wt%, or at least about 95 wt%. In some embodiments, the amount of polar medium (e.g., water) in the LLC lipid nanoparticle composition disclosed herein is from about 80 wt% to about 99 wt%, e.g., about 80 wt%, about 82 wt%, about 84 wt%, about 86 wt%, about 88 wt%, about 90 wt%, about 91 wt%, about 92 wt%, about 93 wt%, about 94 wt%, about 95 wt%, about 96 wt%, about 97 wt%, about 98 wt%, or about 99 wt%. In some embodiments, the amount of polar medium (e.g., water) in the LLC lipid nanoparticle composition disclosed herein is about 90 wt%.

[0163] The nanostructure of the LLC lipid carrier can be determined by any technique known to those of skill in the relevant art. For example, the structure can be determined using small-angle X-ray scattering (SAXS).

[0164] In embodiments, the mesophase transition of the LLC lipid carrier when exposed to a decrease in pH is a transition caused by a decrease in pH of less than pH 10, less than pH 9, less than pH 8, or less than pH 7. In embodiments, the LLC lipid carriers disclosed herein can undergo a mesophase transition at pH 4 to pH 7, pH 5 to pH 7, or pH 5 to pH 6.5, e.g., at pH 5.5 to pH 6.

[0165] In embodiments, the mesophase transition when exposed to a decrease in pH is a transition caused by a decrease in pH of 1 to 4 pH units.

[0166] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is a transition to an intermediate phase with a lower interfacial curvature than the intermediate phase previously occupied by the lipid carrier before the pH decrease.

[0167] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is a transition to an intermediate phase corresponding to a lower CPP value.

[0168] In an embodiment, the intermediate phase transition when exposed to a decrease in pH is an L 2 →H 2 →Q 2 →L 3 transition from one intermediate phase to another intermediate phase following the general intermediate phase transition order. In an embodiment, the phase transition is H 2 →Q 2 .

[0169] In an embodiment, the nanostructure of the non-lamellar lyotropic liquid crystal phase (LLC lipid carrier) is hexagonal (H 2 ) or cubic (Q 2 ). In an embodiment, the non-lamellar lyotropic liquid crystal phase is hexagonal at a pH above about pH 10, above about pH 9, above about pH 8, or above about pH 7. In an embodiment, the non-lamellar lyotropic liquid crystal phase is hexagonal at a pH of about pH 7 or higher, for example, about pH 7.4 or higher, or about pH 7.5 or higher. In an embodiment, the non-lamellar lyotropic liquid crystal phase is cubic at a pH of less than about pH 7.5, for example, about pH 7.4 or less.

[0170] In a preferred embodiment, the non-lamellar lyotropic liquid crystal phase transitions from a hexagonal phase at a pH above about pH 8 to a cubic phase at a pH less than about pH 7.5. In certain embodiments, the non-lamellar lyotropic liquid crystal phase transitions from a hexagonal phase at a pH above about pH 7.5 to a cubic phase at a pH less than about pH 7. In certain embodiments, the non-lamellar lyotropic liquid crystal phase transitions from a hexagonal phase at a pH above about pH 6.5 to a cubic phase at a pH less than about pH 6.5. In a preferred embodiment, the non-lamellar lyotropic liquid crystal phase undergoes a transition mainly from a hexagonal phase to a cubic phase at a pH less than about pH 7. In some embodiments, the transition is completed within 0.5 pH units.

[0171] In a preferred embodiment, the non-lamellar lyotropic liquid crystal phase of the lipid carrier undergoes a transition from a mainly hexagonal phase at pH 7 to a mainly cubic phase at pH 5.5 - 6.0. In other words, the lipid carrier undergoes a transition to an intermediate phase with a lower interfacial curvature and / or a transition to an intermediate phase corresponding to a lower CPP (critical packing parameter) value and / or a transition from L 2 →H 2 →Q 2 →L 3 in a general order of transitions from one intermediate phase to another, but not necessarily through each of these intermediate phases.

[0172] Advantageously, the pH range of 5.5 - 6.0 is a pathologically relevant pH range reported to be found in tumors, certain bacterial and fungal infection sites, and subcellular (intracellular) organelles, and is clearly lower than healthy tissue (about pH 7). The present disclosure is based at least in part on the recognition that the amino lipids disclosed herein can be used to manipulate the structural behavior of lipid carriers to provide carrier particles that can undergo a phase change in response to a pH such as a pH of 5 - 7. For example, the non-lamellar lyotropic liquid crystal phase can undergo a phase change to an intermediate phase with a lower interfacial curvature in response to a reduction in pH from an ambient pH of about 7 - 7.5 to a reduced pH of less than 7, such as a pH of 5 - 7, for example 5.5 - 6.0. Since the reduced pH range may be found in tumors, certain bacterial and fungal infection sites, and subcellular (intracellular) organelles, the LLC lipid carriers disclosed herein are thought to undergo a phase transition at such sites. For example, the LLC lipid nanoparticles disclosed herein can undergo a phase transition from a hexagonal phase at pH 7 to a cubic phase at pH 5.5 - 6.0.

[0173] LLC lipid carriers containing an active agent In embodiments, the LLC lipid carriers disclosed herein contain an active agent. In embodiments, the active agent is encapsulated in the LLC lipid carrier.

[0174] In the context of the present disclosure, encapsulating or including an active agent within an LLC lipid carrier means that when the encapsulated active agent is placed within a biological system, most of the agent is not immediately released, but rather, release is slow and is either facilitated by diffusion of the agent through the lipid carrier or is facilitated by a phase transition of the LLC lipid carrier.

[0175] In embodiments, the active agent is a pharmaceutically or cosmetically active agent. In embodiments, the active agent is selected from the group consisting of peptides, proteins, enzymes, small molecule drugs, and nucleic acids.

[0176] For example, suitable active agents include radionuclides, contrast agents, polymers, antibiotics, fungicides, metal-containing nanoparticles, anti-inflammatory agents, anti-cancer agents, cardiovascular agents, anti-anxiety agents, hormones, growth factors, steroid agents, gene expression modifiers, knockdown agents, siRNA, RNAi agents, DNA, mRNA, dicer substrates, miRNA, shRNA, antisense oligonucleotides, aptamers, and microbial-derived toxins.

[0177] In embodiments, the active agent is a small molecule drug. In preferred embodiments, the active agent is an anti-cancer chemotherapeutic agent. Non-limiting examples of anti-cancer chemotherapeutic agents include temozolomide, dacarbazine, carmustine, lomustine, paclitaxel, docetaxel, vincristine, vinblastine, vinorelbine, etoposide, teniposide, topotecan, irinotecan, doxorubicin, daunomycin, epirubicin, idarubicin, methotrexate, cytarabine, gemcitabine, capecitabine, cisplatin, carboplatin, cyclophosphamide, oxaliplatin, or mixtures thereof, but are not limited thereto.

[0178] In some embodiments, the anti-cancer chemotherapeutic agent is a topoisomerase I inhibitor, such as camptothecin, irinotecan, and SN-38, preferably SN-38, etc.

[0179] In an embodiment, the active agent is an antibiotic.

[0180] In an embodiment, the active agent is a fungicide.

[0181] In an embodiment, the active agent is an oligonucleotide or a nucleic acid.

[0182] In an embodiment, the active agent is a cosmetically active agent.

[0183] As described above, the LLC lipid carriers disclosed herein can undergo a mesophase transition in response to a pH of less than 10, less than 9, less than 8, less than 7.5, less than 7, preferably a pH of 4 to 7, pH 5 to 7, or pH 5 to 6.5, for example, a pH of 5.5 to 6, etc. (e.g., a decrease in pH).

[0184] In an embodiment, the LLC lipid carriers disclosed herein undergo a transition to a mesophase with a lower interfacial curvature in response to a decrease in pH. For example, a decrease in pH can result in a phase transition of the LLC lipid carriers disclosed herein to a phase with a lower critical packing parameter (CPP), such as a transition from a mainly hexagonal phase (e.g., H 2 ) to a mainly cubic phase (e.g., Q 2 ). For example, the phase transition can be L 2 →H 2 →Q 2 →L 3 (i.e., from high CPP to low). In an embodiment, the phase transition is H 2 →Q 2 .

[0185] In embodiments, the LLC lipid carriers disclosed herein undergo a transition to a mesophase with a lower interfacial curvature at about pH 10, about pH 9, about pH 8, about pH 7, or about pH 6. In embodiments, the LLC lipid carriers disclosed herein undergo a transition to a mesophase with a lower interfacial curvature at a pH less than 10, a pH less than 9, a pH less than 8, or a pH less than 7, for example, from pH 4.0 to pH 7.0, pH 5 to pH 7, or pH 5.5 to pH 6.5. In embodiments, the LLC lipid carriers disclosed herein undergo a transition mainly to a cubic phase at a pH less than 10, a pH less than 9, a pH less than 8, or a pH less than 7, for example, from pH 4 to pH 7, pH 5 to pH 7, or pH 5.5 to pH 6.5. In embodiments, the LLC lipid carriers disclosed herein undergo a transition mainly from a hexagonal phase to a cubic phase at a pH less than 10, a pH less than 9, a pH less than 8, or a pH less than 7, for example, from pH 4 to pH 7, pH 5 to pH 7, or pH 5.5 to pH 6.5. This transition can be from a mainly hexagonal phase at about pH 7 or above (e.g., pH 7.4 or above) to a mainly cubic phase at a pH less than 7, for example, from pH 4.0 to pH 7.0, pH 5 to pH 7, or pH 5.5 to pH 6.5. In some embodiments, the LLC lipid carriers disclosed herein undergo a mesophase transition from a hexagonal phase at about pH 7 or above (e.g., pH 7.4 or above) to a cubic phase at about pH 4.0 to pH 7.0, pH 5 to pH 7, or pH 5.5 to pH 6.5. In certain embodiments, the mesophase transition is from an inverse hexagonal phase at about pH 7 or above (e.g., pH 7.4 or above) to a bicontinuous cubic phase at about pH 4.0 to pH 7.0, pH 5 to pH 7, or pH 5.5 to pH 6.5.

[0186] Previous studies have shown that a hexagonal host structure releases encapsulated guests much more slowly than the corresponding cubic host structure. Consistent with these previous studies, and without wishing to be bound by theory, the LLC lipid carriers disclosed herein are thought to release encapsulated active agents when transitioning from a hexagonal to a cubic phase structure at low pH. Thus, the encapsulated agent has a slow release profile while the lipid carrier is in an environment having a surrounding pH, e.g., a physiological pH of about 7-7.5, and a faster release profile when the lipid carrier is in an environment having a reduced pH, e.g., a pH less than 7, e.g., a pH of 7-5, as may be seen. Such reduced pH ranges can be found in tumor sites, sites of certain bacterial and fungal infections, and environments including subcellular organelles.

[0187] Composition of an LLC lipid carrier comprising an active agent In a third aspect, there is provided a cosmetic composition comprising the LLC lipid carrier of the first aspect, a cosmetically active agent, and a cosmetically acceptable carrier, diluent, and / or excipient.

[0188] In a fourth aspect, there is provided a pharmaceutical composition comprising the LLC lipid carrier of the first aspect, a pharmaceutically active agent, and a pharmaceutically acceptable carrier, diluent, and / or excipient.

[0189] Preferably, the cosmetically or pharmaceutically acceptable carrier, diluent, and / or excipient may be or include one or more of a diluent, solvent, pH buffer, binder, filler, emulsifier, disintegrant, polymer, lubricant, oil, fat, wax, coating, viscosity modifier, flow promoter, etc.

[0190] Examples of diluents may include one or more of microcrystalline cellulose, lactose, mannitol, calcium phosphate, calcium sulfate, kaolin, dried starch, powdered sugar, etc. Examples of binders may include one or more of povidone, starch, stearic acid, rubber, hydroxypropylmethylcellulose, etc. Examples of disintegrants may include one or more of starch, croscarmellose sodium, crospovidone, sodium starch glycolate, etc. Examples of solvents may include one or more of ethanol, methanol, isopropanol, chloroform, acetone, methyl ethyl ketone, methylene chloride, water, etc. Examples of lubricants may include one or more of magnesium stearate, zinc stearate, calcium stearate, stearic acid, sodium stearyl fumarate, hydrogenated vegetable oil, glyceryl behenate, etc. The flow promoter may be one or more of colloidal silicon dioxide, talc, or corn starch. Examples of buffers may include, but are not limited to, phosphate buffers, borate buffers, and carbonate buffers. Examples of fillers may include, but are not limited to, one or more gels including gelatin, starch, and synthetic polymer gels. The coating may contain one or more of a film-forming agent, a solvent, a plasticizer, etc. Suitable film-forming agents may be one or more of hydroxypropylmethylcellulose, methylhydroxyethylcellulose, ethylcellulose, hydroxypropylcellulose, povidone, sodium carboxymethylcellulose, polyethylene glycol, acrylate, etc. Suitable solvents may be one or more of water, ethanol, methanol, isopropanol, chloroform, acetone, methyl ethyl ketone, methylene chloride, etc. Plasticizers may be one or more of propylene glycol, castor oil, glycerin, polyethylene glycol, polysorbate, etc.

[0191] Regarding pharmaceutically acceptable carriers, diluents, and / or excipients, refer to Handbook of Excipients 6th Edition, Eds. Rowe, Sheskey & Quinn (Pharmaceutical Press), which provides non-limiting examples of excipients that may be useful according to the present disclosure.

[0192] The cosmetic compositions disclosed herein may further comprise nutrients such as carnitine, ferrous iron, ferric iron salts or elemental iron as iron, iodine, folic acid, vitamins, or micronutrients.

[0193] The cosmetic composition may also comprise a colorant or a flavoring agent.

[0194] It will be understood that the selection of a cosmetic or pharmaceutically acceptable carrier, diluent, and / or excipient depends at least in part on the mode of administration of the formulation. By way of mere example, the composition can be in the form of tablets, capsules, caplets, powders, injectable liquids, suppositories, sustained-release formulations, osmotic pump formulations, or any other form effective and safe for administration.

[0195] In embodiments, the cosmetic composition or pharmaceutical composition is a liquid dispersion of an LLC lipid carrier comprising a cosmetic or pharmaceutically active agent, respectively. The liquid dispersion can be an aqueous dispersion. The liquid dispersion can be encapsulated within standard capsules known for the delivery of liquid formulations. The liquid dispersion can be formulated for delivery by injection, or for topical administration, or for subcutaneous administration.

[0196] Method for delivering an active pharmaceutical agent using an LLC lipid carrier In a fifth aspect, there is provided a method for delivering an active pharmaceutical agent to a biological system, the method comprising administering to the biological system an LLC lipid carrier of the first aspect, an LLC lipid nanoparticle composition of the second aspect, or a composition of the third or fourth aspect.

[0197] In a sixth aspect, there is provided a method for the controlled release of an active agent, comprising the steps of forming the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect, and administering the lipid carrier or composition to a biological system comprising a target region having a predetermined pH, thereby achieving preferential release of the active agent in the target region.

[0198] As discussed, the LLC lipids disclosed herein can provide a desirable release profile for the host active agent due to the entrapment of the active agent within the complex internal architecture of the non-lamellar lyotropic liquid crystal phase at ambient pH, such as physiological pH of about 7.4 (e.g., 7.35 - 7.45).

[0199] The target region can be any region to which it is desirable to deliver the active agent. The target region can be in a biological sample or tissue or fluid of a mammalian subject. For example, the target region can be a tumor, a tissue infected with a bacterial infection, or a tissue infected with a fungal infection. The target region can be a population of cells in a subject or cell culture. For example, the target region can be a subcellular organelle.

[0200] Therapeutic and diagnostic uses of LLC lipid carriers containing an active agent In a seventh aspect, there is provided a method for treating or preventing a disease, disorder, or condition in a mammal, comprising administering to the mammal a therapeutically effective amount of the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect.

[0201] In an eighth aspect, there is provided the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect for use in the treatment or prevention of a disease, disorder, or condition.

[0202] In a ninth aspect, there is provided the use of the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect, in the manufacture of a medicament for the treatment of a disease, disorder, or condition.

[0203] In a tenth aspect, there is provided a method of diagnosing a disease, disorder, or condition in a mammal, the method comprising administering the LLC lipid carrier of the first aspect, the LLC lipid nanoparticle composition of the second aspect, or the composition of the third or fourth aspect, in which the active agent is a labeled active agent, to the mammal or a biological sample obtained from the mammal, to facilitate the diagnosis of a disease, disorder, or condition in the mammal.

[0204] As generally used herein, terms such as "administer" or "administering" refer to introducing the relevant particles or compositions into a mammal by a particular route or vehicle, such as. Routes of administration may include, but are not limited to, topical, parenteral, and enteral, including oral, buccal, sublingual, nasal, anal, gastrointestinal, subcutaneous, intramuscular, and intradermal routes of administration. The compounds, compositions, and methods of the present invention can be used for both delivery to a specific site of administration or systemic delivery.

[0205] "Treat", "treatment", or "treating" means administering the relevant particles or compositions to a subject to at least improve, reduce, or suppress existing signs or symptoms of a disease, disorder, or condition experienced by the subject to the extent that the medical condition is improved according to clinically acceptable standards. For example, "treating a bacterial or fungal infection" means reducing the infection, eradicating the infection, or alleviating the symptoms of the infection in the patient, and the improvement and alleviation are evaluated by clinically acceptable standardized tests and / or empirical tests, including swab sample tests.

[0206] "Prevent", "preventing", or "preventive" means prophylactically administering a relevant particle or composition to a subject who does not exhibit signs or symptoms of a disease, disorder, or condition but is expected or anticipated to be likely to exhibit such signs or symptoms without prevention. Preventive treatment can at least reduce or partially ameliorate the expected symptoms or signs.

[0207] As used herein, "effective amount" or "therapeutically effective amount" refers to the administration of an amount of a relevant particle or composition sufficient to prevent the occurrence of symptoms of a condition being treated, or to halt the worsening of symptoms, or to treat and alleviate or at least reduce the severity of symptoms. The effective amount will vary as understood by one of ordinary skill in the art depending on, for example, the age, sex, weight of the patient, etc. A suitable dosage or dosing regimen can be determined through routine testing or based on current treatment regimens for the active agent being delivered via the particles of the first or second aspect.

[0208] As used herein, the terms "subject" or "individual" or "patient" can refer to any subject for whom treatment is desired, particularly a vertebrate subject, and more particularly a mammalian subject. Suitable vertebrate animals include, but are not limited to, primates, birds, domestic animals (e.g., sheep, cows, horses, donkeys, pigs), laboratory test animals (e.g., rabbits, mice, rats, guinea pigs, hamsters), companion animals (e.g., cats, dogs), and captured wild animals (e.g., foxes, deer, dingoes). Preferred subjects are humans in need of treatment for a disease, disorder, or condition described herein. However, it will be understood that the foregoing terms do not necessarily imply the presence of symptoms. In one embodiment, the subject is a human being undergoing treatment for a bacterial or fungal infection, particularly a gram-negative bacterial infection.

[0209] As used herein, the terms "combination therapy" and "combined therapy" mean the treatment of a subject in need thereof by administering, by any suitable means, one or more particles or compositions described herein and one or more agents for treating a disease, disorder, or condition, simultaneously, sequentially, separately, or in a single pharmaceutical formulation or combination. When administered in separate dosage forms, the number of dosages administered per day for each compound may be the same or different. The relevant particles or compositions and one or more active agents for treating a disease, disorder, or condition may be administered via the same or different routes of administration.

[0210] As discussed above, the LLC lipid carriers of the first aspect can include an active agent that can be pharmaceutically active. The lipid carriers can include, for example, two or more different pharmaceutically active agents if the agents are effective against the same or different targets. The agents can have synergistic activity. For example, the delivery of different agents can be advantageous when treating a polymicrobial infection or targeting tumor cells that express two or more different molecular targets.

[0211] The LLC lipid carriers (e.g., LLC lipid nanoparticles) disclosed herein are particularly suitable for the controlled delivery of active agents that can be pharmaceutically or cosmetically active. Accordingly, the disclosure also provides a method of treating, preventing, or diagnosing a disease, disorder, or condition, comprising administering to a subject the LLC lipid carriers (e.g., LLC lipid nanoparticles) disclosed herein, the LLC lipid nanoparticle compositions disclosed herein, or the cosmetic or pharmaceutical compositions disclosed herein.

[0212] As discussed previously, the LLC lipid carriers disclosed herein can undergo pH-responsive phase changes, for example, upon a reduction in pH from a physiological pH of about 7.4 (e.g., 7.35 - 7.45) to a pH of 7 - 5. Such reduced pH ranges can be found in environments including tumors, sites of certain bacterial and fungal infections, and subcellular organelles, and can induce phase changes of the disclosed non-lamellar lyotropic liquid crystal phases. Also, the phase changes can promote the release of encapsulated active agents.

[0213] Accordingly, in some embodiments, diseases, disorders, or conditions suitable for treatment, prevention, or diagnosis by the methods disclosed herein are cancer or bacterial or fungal infections.

[0214] In some embodiments, diseases, disorders, or conditions suitable for treatment, prevention, or diagnosis by the methods disclosed herein are tumors or other malignancies. As used herein, cancer, tumor, and malignancy refer to a disease, disorder, or condition characterized by abnormal or unusual cell growth, differentiation, and / or migration, often accompanied by an abnormal or unusual molecular phenotype that includes one or more genetic mutations or other genetic changes associated with carcinogenesis, expression of tumor markers, loss of expression or activity of tumor suppressors, and / or expression of abnormal or unusual cell surface markers. Or refer to cells or tissues related to a disease, disorder, or condition. In general embodiments, cancers, tumors, and malignancies can include, but are not limited to, sarcomas, lymphomas, leukemias, solid tumors, granulomas, gliomas, carcinomas, melanomas, and metastatic cancers. A more comprehensive list of cancers, tumors, and malignancies can be found at the National Cancer Institute website http: / / www.cancer.gov / cancertopics / types / alphalist.

[0215] In some embodiments, the disease, disorder, or condition is a bacterial infection. In one embodiment, the disease, disorder, or condition is caused by or associated with a pathogen. The pathogen can be a bacterium or fungus capable of infecting mammals.

[0216] In embodiments where the infectious disease suitable for treatment, prevention, or diagnosis by the methods disclosed herein is a Gram-negative infectious disease, the bacteria can be selected from the group consisting of Enterobacteriaceae, Pseudomonas, Vibrio, Campylobacter, Legionella, Neisseria, Hemophilus, and Bartonella.

[0217] In embodiments, the Gram-negative bacteria can be selected from the group consisting of E. coli, Pseudomonas aeruginosa, Klebsiella, Acinetobacter baumannii, Neisseria gonorrhoeae, and Enterobacteriaceae.

[0218] In embodiments where the infectious disease suitable for treatment, prevention, or diagnosis by the methods disclosed herein is a Gram-positive infectious disease, the bacteria can be selected from the group consisting of Staphylococci, Streptococci, Pneumococci, Enterococci, Bacilli, Clostridia, Corynebacterium, Listeria, and Actinomyces.

[0219] Non-limiting examples of pathogenic bacteria include, but are not limited to, Staphylococcus aureus, Helicobacter pylori, Bacillus anthracis, Bordatella pertussis, Corynebacterium diptheriae, Clostridium tetani, Clostridium botulinum, Streptococcus pneumoniae, Streptococcus pyogenes, Listeria monocytogenes, Hemophilus influenzae, Pasteurella multicida, Shigella dysenteriae, Mycobacterium tuberculosis, Mycobacterium leprae, Mycoplasma pneumoniae, Mycoplasma hominis, Neisseria meningitidis, Neisseria gonorrhoeae, Rickettsia rickettsii, Legionella pneumophila, Klebsiella pneumoniae, Pseudomonas aeruginosa, Propionibacterium acnes, Treponema pallidum, Chlamydia trachomatis, Vibrio cholerae, Salmonella typhimurium, Salmonella typhi, Borrelia burgdorferi, and Yersinia pestis.

[0220] Non-limiting examples of fungi include, but are not limited to, Candida and Aspergillus species. In embodiments, the fungus associated with or causing a disease, disorder, or condition is selected from the group consisting of C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. dublinensis, C. krusei, C. lusitaniae, C. Auris, and A. fumigatus.

[0221] As discussed previously, the phase changes of the LLC lipid carriers disclosed herein, and the associated release of encapsulated active agents, can occur in subcellular (intracellular) organelles. Typically, the delivery of therapeutic nucleic acids is determined by the delivery of the nucleic acids to the cells in which they exert their mode of action. Thus, any condition suitable for treatment with oligonucleotides or nucleic acids can be treated with the LLC lipid carriers disclosed herein containing an active agent. Suitable oligonucleotides or nucleic acids can be selected from gene expression modifiers, knockdown agents, small interfering RNAs (siRNAs), RNA interference (RNAi), mRNAs, DNAs, antisense oligonucleotides, functional nucleic acids such as ribozymes, aptamers and Spiegelmers, Dicer substrates, microRNAs (miRNAs), and short hairpin RNAs (shRNAs).

[0222] When the active agent is a labeled active agent, the lipid carrier of the second aspect containing the active agent, or the composition of the third or fourth aspect containing the active agent, can be used for the detection or diagnosis of the diseases, disorders, or conditions discussed previously.

[0223] Typically, the detection or diagnosis is performed in mammals or in cell populations.

[0224] In an embodiment, the labeled active agent is a contrast agent.

[0225] The following numbered embodiments are disclosed herein.

[0226] Embodiment 1. Formula (I): Cyc-L-R (I), [wherein Cyc is a nitrogen heterocycle or heteroaryl, L is an amide linker, R is a C10-C44 carbon chain] lipid compound.

[0227] The lipid compound according to Embodiment 1, wherein Cyc is selected from a 5- or 6-membered nitrogen-heterocyclyl or -heteroaryl group.

[0228] The lipid compound according to Embodiment 1 or 2, wherein Cyc is selected from the group consisting of piperidinyl, piperazinyl, pyrrolinyl, pyrrolidinyl, pyrazolidinyl, morpholinyl, imidazolinyl, imidazolidinyl, pyrrolinyl, pyrazolinyl, thiazolidinyl, thiomorpholinyl, tetrahydropyridyl, dihydropyridyl, tetrahydropyridinidinyl, pyrimidinyl, pyridyl, pyrrolyl, imidazolyl, pyrazolyl, oxazolyl, oxadiazolyl, pyrazinyl, tetrazolyl, thiazolyl, isoxazolyl, isothiazolyl, isoxazololonyl, triazolyl, oxadiazolyl, thiadiazolyl, and pyridazinyl.

[0229] The lipid compound according to any one of the preceding embodiments, wherein L contains an optional carbon chain between Cyc and the amide group.

[0230] The lipid compound according to Embodiment 4, wherein the carbon chain between Cyc and the amide group, when present, is a C1-C6 chain.

[0231] The lipid compound according to any one of the preceding embodiments, wherein R is a C10-C36 alkyl, alkenyl, or alkynyl chain.

[0232] The lipid compound according to any one of the preceding embodiments, wherein R is a C12-C24 alkyl or alkenyl chain.

[0233] The lipid compound according to any one of the preceding embodiments, wherein R is a C12-C18 alkenyl chain.

[0234] The lipid compound according to any one of the preceding embodiments, wherein R is optionally interrupted by one or more heteroatoms.

[0235] Embodiment 10. The amino lipid compound of formula (I) is a compound of formula (Ib): [Chem.] [wherein Cyc is a nitrogen heterocycle or heteroaryl, R is a C12 - C24 alkyl or alkenyl chain, n is an integer from 1 to 6] is the lipid compound according to any one of the preceding embodiments.

[0236] Embodiment 11. The lipid compound according to Embodiment 10, wherein Cyc is a 6 - membered nitrogen - heterocycle or - heteroaryl.

[0237] Embodiment 12. The lipid compound according to Embodiment 11, wherein Cyc is selected from the group consisting of pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, tetrahydropyridyl, dihydropyridyl, tetrahydropyrimidinyl, pyrazinyl, and pyridazinyl.

[0238] Embodiment 13. The lipid compound according to Embodiment 12, wherein Cyc is selected from the group consisting of pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholinyl, and pyrazinyl.

[0239] Embodiment 14. The lipid compound according to any one of Embodiments 10 - 13, wherein N is an integer from 1 to 4.

[0240] Embodiment 15. The lipid compound according to any one of Embodiments 10 - 14, wherein R is C12 - C24 alkenyl.

[0241] Embodiment 16. The lipid compound according to Embodiment 14, wherein R is C14 - C22 alkenyl.

[0242] Embodiment 17. The lipid compound according to any one of the preceding embodiments, wherein R is selected from the group consisting of oleyl, linoleoyl, linolenoyl, phytanoyl, and farnesoyl.

[0243] Embodiment 18. The lipid compound according to any one of Embodiments 10 to 17, wherein R is optionally interrupted by one or more heteroatoms.

[0244] Embodiment 19. The lipid compound is [Chemical formula] The lipid compound according to any one of the preceding embodiments, which is selected from the group consisting of [[wherein R is as defined in any one of the preceding embodiments]].

[0245] Embodiment 20. The lipid compound is [Chemical formula]

[0246] Embodiment 21. R is [Chemical formula]

[0247] Embodiment 22. A lipid carrier comprising a lipid having an amide linker, the lipid carrier being adapted to undergo a mesophase transition when exposed to a decrease in pH.

[0248] Embodiment 23. The lipid carrier according to Embodiment 22, further comprising a structural lipid compound, the structural lipid compound being amphiphilic.

[0249] Embodiment 24. The lipid carrier according to Embodiment 23, wherein the structural lipid compound comprises a hydrophobic tail group selected from the group consisting of oleyl, linoleoyl, linolenoyl, phytanoyl, farnesoyl, or an extended aliphatic hydrophobic substance.

[0250] Embodiment 25. The lipid carrier according to Embodiment 24, wherein the hydrophobic tail group is selected from oleyl, linoleoyl, and phytanoyl.

[0251] Embodiment 26. The lipid carrier according to embodiment 24 or 25, wherein the hydrophobic tail group is oleyl.

[0252] Embodiment 27. The lipid carrier according to any one of embodiments 23 to 26, wherein the structural lipid compound is monoolein (glycerol monooleate).

[0253] Embodiment 28. The lipid carrier according to any one of embodiments 22 to 27, wherein the lipid carrier is a non-lamellar lyotropic liquid crystal phase lipid carrier.

[0254] Embodiment 29. The lipid carrier according to embodiment 28, wherein the non-lamellar lyotropic liquid crystal phase lipid carrier is a self-assembled non-lamellar lyotropic liquid crystal phase lipid carrier.

[0255] Embodiment 30. The lipid carrier according to embodiment 28 or 29, wherein the non-lamellar lyotropic liquid crystal phase lipid carrier is in the form of nanoparticles.

[0256] Embodiment 31. The lipid carrier according to any one of embodiments 28 to 30, wherein the non-lamellar lyotropic liquid crystal phase lipid carrier further comprises a stabilizer.

[0257] Embodiment 32. The lipid carrier according to embodiment 31, wherein the stabilizer is a stabilizing polymer.

[0258] Embodiment 33. The lipid carrier according to embodiment 32, wherein the stabilizing polymer is a non-ionic triblock copolymer.

[0259] Embodiment 34. The lipid carrier according to embodiment 32 or 33, wherein the stabilizing polymer is Pluronic F127 (Poloxamer407) or Poloxamer80.

[0260] Embodiment 35. The lipid carrier according to any one of embodiments 22 to 34, wherein the lipid having an amide linker is present in a weight percentage of the total lipid content of the lipid carrier suitable for causing a mesophase transition at a selected pH.

[0261] Embodiment 36. The lipid carrier according to any one of Embodiments 22 to 35, wherein the lipid having an amide linker accounts for about 5% to about 50% by weight of the total lipid content of the lipid carrier.

[0262] Embodiment 37. The lipid carrier according to any one of Embodiments 22 to 36, wherein the lipid having an amide linker is the lipid compound according to any one of Embodiments 1 to 21.

[0263] Embodiment 38. The lipid carrier according to any one of Embodiments 28 to 37, wherein the non-lamellar lyotropic liquid crystal phase is a hexagonal or cubic non-lamellar lyotropic liquid crystal phase.

[0264] Embodiment 39. The lipid carrier according to Embodiment 38, wherein the non-lamellar lyotropic liquid crystal phase is a hexagonal non-lamellar lyotropic liquid crystal phase at a pH above about pH 8.

[0265] Embodiment 40. The lipid carrier according to Embodiment 38 or 39, wherein the non-lamellar lyotropic liquid crystal phase is a cubic non-lamellar lyotropic liquid crystal phase at a pH below about pH 7.5.

[0266] Embodiment 41. The lipid carrier according to any one of Embodiments 38 to 40, wherein the non-lamellar lyotropic liquid crystal phase is a hexagonal non-lamellar lyotropic liquid crystal phase at a pH above about pH 8 and a cubic non-lamellar lyotropic liquid crystal phase at a pH below about pH 7.5.

[0267] Embodiment 42. The lipid carrier according to Embodiment 38 or 39, wherein the non-lamellar lyotropic liquid crystal phase is a hexagonal non-lamellar lyotropic liquid crystal phase at a pH above about pH 7.5 and a cubic non-lamellar lyotropic liquid crystal phase at a pH below about pH 7.

[0268] Embodiment 43. The lipid carrier according to Embodiment 38 or 39, wherein the non-lamellar lyotropic liquid crystal phase is a hexagonal non-lamellar lyotropic liquid crystal phase at a pH above about pH 7 and a cubic non-lamellar lyotropic liquid crystal phase at a pH below about pH 6.5.

[0269] Embodiment 44. The lipid carrier according to any one of Embodiments 35 to 37, wherein the non-lamellar lyotropic liquid crystal phase is a hexagonal non-lamellar lyotropic liquid crystal phase at a pH above about 6.5 and a cubic non-lamellar lyotropic liquid crystal phase at a pH of about 6.5 or less.

[0270] Embodiment 45. The lipid carrier according to any one of Embodiments 22 to 44, further comprising an active agent.

[0271] Embodiment 46. The lipid carrier according to Embodiment 45, wherein the active agent is pharmaceutically or cosmetically active.

[0272] Embodiment 47. The lipid carrier according to Embodiment 45 or 46, wherein the active agent is selected from the group consisting of peptides, proteins, enzymes, small molecule drugs, and nucleic acids.

[0273] Embodiment 48. The lipid carrier according to any one of Embodiments 45 to 47, wherein the active agent is selected from the group consisting of radionuclides, contrast agents, polymers, antibiotics, fungicides, metal-containing nanoparticles, anti-inflammatory agents, anti-tumor agents, cardiovascular agents, anti-anxiety agents, hormones, growth factors, steroid agents, gene expression modifiers, knockdown agents, siRNA, RNAi agents, mRNA, DNA, dicer substrates, miRNA, shRNA, antisense oligonucleotides, aptamers, and microbial-derived toxins.

[0274] Embodiment 49. The lipid carrier according to any one of Embodiments 45 to 48, wherein the active agent is a topoisomerase I inhibitor.

[0275] Embodiment 50. The lipid carrier according to Embodiment 49, wherein the topoisomerase I inhibitor is selected from camptothecin, irinotecan, and SN-38.

[0276] Embodiment 51. A cosmetic composition comprising the lipid carrier according to any one of Embodiments 22 to 46, and a cosmetically acceptable carrier, diluent, and / or excipient.

[0277] Embodiment 52. A pharmaceutical composition comprising the lipid carrier according to any one of Embodiments 22 to 50, and a pharmaceutically acceptable carrier, diluent, and / or excipient.

[0278] Embodiment 53. The cosmetic composition according to Embodiment 51, or the pharmaceutical composition according to Embodiment 52, wherein the composition is an injectable composition.

[0279] Embodiment 54. The cosmetic composition according to Embodiment 51, or the pharmaceutical composition according to Embodiment 52, wherein the composition is a composition for topical administration.

[0280] Embodiment 55. The cosmetic composition according to Embodiment 51, or the pharmaceutical composition according to Embodiment 52, wherein the composition is a composition for subcutaneous administration.

[0281] Embodiment 56. A method for delivering an active agent to a biological system, comprising the step of administering to the biological system the lipid carrier according to any one of Embodiments 45 to 50, or the composition according to any one of Embodiments 51 to 55.

[0282] Embodiment 57. The method according to Embodiment 56, wherein the delivery of the active agent in the biological system is altered by the response of the lipid carrier to a predetermined pH range.

[0283] Embodiment 58. The method according to Embodiment 57, wherein the response includes a phase structure transition of the lipid carrier.

[0284] Embodiment 59. The method according to Embodiment 58, wherein the phase structure transition is a transition of the lipid carrier from a hexagonal crystal to a cubic crystal phase structure.

[0285] Embodiment 60. The method according to Embodiment 59, wherein the transition occurs at a pH of less than about 8.

[0286] Embodiment 61. The method according to Embodiment 59 or 60, wherein the transition occurs at a pH of about 7.5 or less.

[0287] Embodiment 62. The method according to any one of Embodiments 59 to 61, wherein the metastasis occurs at a pH of about 7 or less.

[0288] Embodiment 63. The method according to any one of Embodiments 59 to 62, wherein the metastasis occurs at a pH of about 6.5 or less.

[0289] Embodiment 64. The method according to any one of Embodiments 56 to 63, wherein the response results in preferential release of the active agent in a predetermined pH range in a biological system.

[0290] Embodiment 65. A method for controlled release of an active agent, comprising forming a lipid carrier according to any one of Embodiments 45 to 50, or a composition according to any one of Embodiments 51 to 55, and administering the lipid carrier or composition to a biological system comprising a target region having a predetermined pH, thereby achieving preferential release of the active agent in the target region.

[0291] Embodiment 66. The method according to Embodiment 65, wherein the lipid carrier undergoes a phase structure transition in response to a predetermined pH.

[0292] Embodiment 67. The method according to Embodiment 66, wherein the phase structure transition is a transition of the lipid carrier from a hexagonal crystal to a cubic crystal phase structure.

[0293] Embodiment 68. A method for treating or preventing a disease, disorder, or condition in a mammal, comprising administering to the mammal a therapeutically effective amount of a lipid carrier according to any one of Embodiments 45 to 50, or a composition according to any one of Embodiments 51 to 55.

[0294] Embodiment 69. A lipid carrier according to any one of Embodiments 45 to 50, or a composition according to any one of Embodiments 51 to 55, for use in the treatment or prevention of a disease, disorder, or condition.

[0295] Use of the lipid carrier according to any one of Embodiments 45 to 50, or the composition according to any one of Embodiments 51 to 55, in the manufacture of a medicament for the treatment of a disease, disorder or condition.

[0296] Embodiment 71. A method for diagnosing a disease, disorder or condition in a mammal, comprising administering to the mammal or a biological sample obtained from the mammal the lipid carrier according to any one of Embodiments 45 to 50, or the composition according to any one of Embodiments 51 to 55, wherein the active agent is a labeled active agent, and facilitating the diagnosis of the disease, disorder or condition in the mammal.

[0297] Embodiment 72. The method according to Embodiment 68 or 71, the lipid carrier or pharmaceutical composition for use according to Embodiment 69, or the use according to Embodiment 70, wherein the disease, disorder or condition is cancer or a bacterial or fungal infection.

[0298] Embodiment 73. The lipid carrier according to any one of the preceding embodiments, wherein the water content of the lipid carrier itself is about 20% to about 60% by weight.

[0299] The following experimental section describes in more detail certain characterizations of the compounds of the present invention and their effectiveness. Certain embodiments of the compounds of the present invention and their effectiveness are intended to be illustrated without limiting the present invention in any way.

Examples

[0300] Hereinafter, the present disclosure will be further described with reference to the following non-limiting examples and the accompanying drawings.

[0301] Materials 4-(Aminomethyl)pyridine, picolylamine, 4-(2-aminoethyl)morpholine, 1-(2-aminoethyl)piperidine, N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC), hydroxybenzotriazole (HOBt), dimethylaminopyridine (DMAP), dichloromethane (DCM), n-hexane, ethyl acetate, sodium sulfate, sodium chloride, deuterated chloroform, deuterated dimethyl sulfoxide, deuterium oxide, and Pluronic F-127 were purchased from Sigma-Aldrich. Milli-Q water (18.2 18.2 MΩ·cm) was used for all aqueous preparations. Monoolein (MO) and oleic acid (OA) were obtained from Nu-chek-Prep, Inc (Elysian, MN, USA) with a purity of greater than 99%. SN-38 was procured from Adooq bioscience.

[0302] Example 1: Synthesis, Purification, and Analysis of Amino Lipids The amino lipids disclosed herein contain a hydrophilic head group comprising a nitrogen heterocycle or heteroaryl conjugated to a hydrophobic carbon chain tail via an amide linker. In the following examples, a C18 oleyl tail was used and kept constant for all synthetic lipids, while the length of the head group and amide linker was varied.

[0303] The amino lipids were synthesized using an amide coupling reaction between oleic acid (OA) and an amine carrying the head group. EDC (3.9 mmol, 1.1 equivalents) was added to a cooled solution of OA in DCM (3.54 mmol, 1.0 equivalent). The solution was stirred at 0 - 5 °C for 30 minutes, and the amine (3.54 mmol, 1.0 equivalent) and DMAP (0.7 mmol, 0.2 equivalent) of this cooled reaction mass were added. The reaction temperature was slowly raised to room temperature (RT) and stirred at RT for 24 hours. The solvent was removed using a rotary evaporator, and the resulting crude material was purified using a flash silica column. The synthesized amino lipids were subjected to analysis by nuclear magnetic resonance (NMR) imaging ( 1 H). 1The 1H NMR spectrum was obtained using a Bruker 300 Ultrashield™ NMR spectrometer.

[0304] Results: The physical state of the synthesized amino lipid was semi-solid at room temperature. Generally, the reaction yield was in the range of 60 - 75%, and the purity was 85 - 95%. The structure and purity of the synthesized amino lipid were confirmed by NMR (data not shown). An exemplary structure synthesized by this method is shown in Figure 2. In the following examples, the following amino lipids were used or referenced. [Table 1]

[0305] Example 2: Preparation of LLC Nanoparticles Containing Amino Lipids The LLC lipid carriers disclosed herein can be in the bulk phase or dispersed in the form of nanoparticles containing the amino lipids and structural amphiphilic lipids disclosed herein. The structural amphiphilic lipid can constitute the majority of the nanoparticles depending on the amount of amino lipid used. In the following examples, monoolein (MO) was used as the structural amphiphilic lipid.

[0306] LLC nanoparticles composed of amino lipid and MO were formulated using the high-throughput method reported in Tran et al. 2016, which is incorporated herein by reference. The amount of amino lipid added to the formulation is defined as R MO represented by, and herein, R AL can be referred to as. Briefly, MO (20 mg / 1 mL ethanol) and amino lipid (20 mg / 1 mL ethanol) were mixed at 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 60:40, 50:50, increasing the ratio of amino lipid, to give R values of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, and 0.5 MOValues were obtained. 1 mL of the lipid solution was added to each well of a 96-well deep well block (Greiner Bio-One, Interpath Inc., Australia). Then, an organic solvent was removed using a centrifugal evaporator (GeneVac, NSW, Australia) to obtain a dried lipid mixture.

[0307] In these examples, Pluronic F-127 was used to stabilize the nanoparticles. Thus, 1 mL of F127 (a solution of 20 mg in 1 mL of DI water) was added to the dried lipid mixture. The resulting mixture was sonicated by a high throughput multi-probe sonicator (Q Sonica) to obtain an opaque dispersion.

[0308] Nanoparticles can also be prepared by finely tuning their pH responsiveness using a mixture of two or more amino lipids.

[0309] Results: Various amounts of amino lipids from 5 wt% to 50 wt% were added to MO and these were dispersed with Pluronic F-127. The amount of Pluronic F-127 was kept at 10 wt% of the total amount of lipids in the system. All these formulations were well dispersed without visual sedimentation or phase separation.

[0310] Example 3: Particle Size and Polydispersity Index of LLC Lipid Nanoparticles The average hydrodynamic diameter and polydispersity index (PDI) of the lipid nanoparticles were measured by dynamic light scattering (DLS) using a Malvern Zetasizer Nano ZS (Malvern Instruments, UK). All measurements were performed at 25 °C (n = 3) by loading the lipid formulation (10 μL) onto a transparent 96-well half area polystyrene plate and diluting with 190 μL of milli-Q water (Zhai et al. 2015).

[0311] Results The above-mentioned nanoparticle formulation was investigated for average particle size and polydispersity index (PDI). The obtained values are shown in Tables 1 and 2, respectively.

Table 2

Table 3

[0312] Tables 1 and 2 show the particle size and polydispersity index (PDI) data for nanoparticle formulations prepared by adding amino lipids to MO dispersed with the stabilizer Pluronic F-127. The amount of amino lipid added to the formulation is represented by R MO as defined as the weight / weight ratio of amino lipid to total lipid, and herein may be referred to as R AL . The measured values were averaged from triplicates and the results were reported as mean + / - standard deviation.

[0313] Generally, the nanoparticles had a hydrodynamic diameter in the range of 137 nm to 300 nm, and the PDI was in the range of 0.15 to 0.40 (Tables 1 and 2). To evaluate the stability of the nanoparticles at RT, the particle size of the nanoparticles was also measured after standing at RT for 30 days after preparation. No significant differences in size or physical appearance were observed, indicating that the nanoparticles were stable at room temperature for at least 30 days (data not shown).

[0314] Example 4: Phase Behavior of LLC Lipid Nanoparticles The effects of amino lipid concentration and pH on the mesophase of the nanoparticles were determined using high-throughput formulation and synchrotron small-angle X-ray scattering (SAXS).

[0315] The nanoparticle preparation (50 μL) was loaded into a transparent 96-well half-area polystyrene plate (Greiner Bio-One, Interpath Inc., VIC, Australia), and 50 μL of a suitable buffer solution (citrate buffer) at the specified pH was added to the plate. The phase behavior of the nanoparticles was characterized at the SAXS / WAXS beamline of the Australian Synchrotron. This instrument used an X-ray wavelength of λ = 1.128 Å (11.0 keV) with a typical flux of about 10 photons / second. The distance from the sample to the detector was selected as 1.6 m to provide a q range of 0.01 - 0.5 Å (scattering vector q = 4πsin(θ / 2) / λ, where θ is the scattering angle and λ is the wavelength). The sample scattering patterns were obtained at 25 °C and 37 °C following the procedures reported in the literature. The plate was placed in a holder perpendicular to the X-ray beam. The sample holder was moved by a motor controlled by in-house ScatterBrain software for automated SAXS screening. The sample temperature was controlled by a circulating water bath and maintained at 25 °C or 37 °C. Two-dimensional X-ray diffraction images were recorded on a Dectris-Pilatus1-M detector using ScatterBrain. The scattering images were integrated into one-dimensional plots of intensity versus q for phase discrimination. The mesophases of the nanoparticles were assigned by matching the relative positions of the scattering peaks to the known patterns of the bicontinuous cubic, hexagonal, lamellar, and micellar cubic phases. The lattice parameters of the nanoparticles were calculated using IDL-based software AXcess following the described method (Tran et al. 2018; Tran et al. 2016). -1 As detailed previously in Example 2, the lipid nanoparticles described herein are of 8 different compositions (R

[0316] Results MO ​At ( = 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5), the synthesized amino lipids were prepared by doping MO and dispersed with Pluronic F-127. The mesophase structures of the drug-free formulations were determined by SAXS over 10 different pH values (pH range of 2.5 - 10). Figure 3 represents the SAXS partial phase diagram of these nanoparticles at 25 °C. The shape of the amphiphilic substance can be characterized by the critical packing parameter (CPP). CPP = V / al, where V is the effective volume of the hydrophobic tail of the amphiphilic substance, a is the effective cross-sectional area of the head group, and l is the effective length of the hydrocarbon chain. The lamellar phase (L α ) is typically observed with zero interfacial curvature. When the CPP value is greater than 1, inverse phases such as the Q 2 phase and the H 2 phase are formed with an increasing negative interfacial curvature. The Q 2 phase consists of lipid bilayers arranged in a periodic 3D structure by twisting the bilayer into the shape of an infinite periodic minimal surface. H 2 is a closed extended micelle columnar structure, and there is no direct contact between the water inside and outside the H 2 phase.

[0317] High-throughput SAXS experiments demonstrated that both the amino lipid composition and pH affected the internal mesophase of the nanoparticles, as discussed below.

[0318] (a) Effect of adding amino lipids to MO nanoparticles at neutral pH In the case of MO, the head group size is relatively small, resulting in the formation of an inverse bicontinuous cubic phase with negative surface Gaussian curvature in an aqueous environment. Previous studies have shown that MO nanoparticles stabilized with Pluronic F-127 exhibited a primitive cubic phase (Im3m space group) at room temperature (Tran et al. 2015; Sarkar et al. 2018). At neutral pH, for lipids 10, 11, and 13, when adding increasing amounts of amino lipids to MO nanoparticles, the sequence of bicontinuous cubic → hexagonal → inverse micelle (Q 2 →H 2 →L2 ) The intermediate phase structure was changed to follow. The continuous change can be rationalized by the change in the effective molecular critical packing parameter (CPP). At neutral pH, adding lipids 10, 11, and 13 to MO can further increase the effective CPP and result in more curvature in the lipid membrane. MO has a 2-OH (hydroxyl) group as part of its head group, and the hydroxyl group can also participate in hydrogen bonding with adjacent water molecules, making the effective head group area of MO larger than that of lipids 10, 11, and 13.

[0319] For lipid 10-doped nanoparticles, the Q 2 to H 2 transition occurred at R MO = 0.4. For lipid 11-doped nanoparticles at R MO = 0.4, the L 2 phase was observed.

[0320] The lipids 10 and 11 prepared herein can be compared with lipids 1 and 2, which are comparative substances having an ester linker instead of an amide linker (Rajesh et al. 2021, the content of which is incorporated herein by reference). The amino lipids disclosed herein contain an amide group in the linker, while the disclosed comparative substances were ester-containing amino lipids. Interestingly, the Q 2 to H 2 transition occurs at a much higher R MO for lipid 10-doped MO nanoparticles compared to lipid 1. The Q 2 to H 2 transition at pH 7 occurs at a much higher R MOThe fact that this occurs with the amide-containing amino lipids of the present invention is most likely due to the hydrophilicity of the amide bond. The partition coefficient P is defined as the ratio of the concentration of a compound between an organic phase and an aqueous phase, and the logP value can be used as a measure of lipophilicity. The predicted logP values of the comparative lipid 1 and lipid 10 of the present disclosure are 6.95 and 6.12 (Chemdraw software), respectively, indicating that the comparative amino lipid, lipid 1, is more lipophilic.

[0321] For lipid 12, the opposite trend was observed, so that when the amount of lipid 12 was increased and added, the change was from the bicontinuous cubic mesophase → (mixed cubic + sponge) mesophase → sponge (Q 2 →Q 2 +L 3 →L 3 ) mesophase. The L 3 phase is usually found in a narrow region between the L a phase and the Q 2 phase and represents a "melted" cubic phase structure without long-range order. The SAXS diffraction pattern of the L 3 phase contains only a single broad scattering peak due to the absence of a periodic structure. Coexistence of the sponge phase and the Q 2 phase was observed, and adding more lipid 12 resulted in a single sponge phase. This difference is due to the chemical structure of lipid 12, which is an amide linker bound to a hydrophilic morpholine, and increases the effective head group area to be larger than the effective head group area of MO. By adding additives that are more polar than MO or have a larger head group size, the effective CPP can be further reduced, resulting in a lower curvature in the lipid membrane.

[0322] (b) Effect of pH on the mesophase structure of amino lipid-containing MO nanoparticles For each system, the pH was varied from pH 2 to pH 8, and Synchrotron SAXS was used to determine the effect of pH on the mesophase structure of MO nanoparticles doped with four different amino lipids. The SAXS results for nanoparticles stabilized by F-127 are presented in Figure 3. MO nanoparticles stabilized by F-127 exhibited a primitive cubic phase independent of pH between pH 2.5 and pH 8 (data not shown). In general, as the pH decreased, the mesophase of the amino lipid-doped MO nanoparticles converted to a structure with a lower interfacial curvature. This observation confirmed that the ionization state of the amino lipid plays an important role in the pH responsiveness of MO nanoparticles. The headgroups containing a tertiary amine moiety acquire protons at low pH and obtain a positive charge resulting from protonation. This combination with the electrostatic repulsion of the ionized headgroups leads to a larger effective headgroup size and a smaller CPP. At higher pH, depending on the apparent pKa of the amino lipid, the headgroups of the amino lipid remain non-ionized and thus have a small effective headgroup (larger CPP). Thus, as summarized in Figure 4, in the self-assembled lipid microenvironment, a decrease in pH results in a transition from high CPP to low CPP, or in other words, an L 2 →H 2 →Q 2 phase transformation sequence. As shown in Figure 4, at pH -7, when lipid 10, 11, or lipid 13 was added, the observed phase transition was Q 2 →H 2 →L 2 and for nanoparticles doped with lipid 12, the phase transition of Q 2 →Q 2 +L 3 →L 3 was observed. By changing the pH, a decrease in interfacial curvature was brought about, and the transition tendency followed the sequence L 2 →H 2 →Q 2 .

[0323] The ionizable head group moiety of the amino lipid is present at the lipid-water interface. Each of the previously prepared nanoparticle formulations is unique in terms of the amino lipid type and varies in amount for each of these, and thus can have a different apparent pKa as the pH and ionic strength are changed. This apparent pKa is mainly influenced by the interfacial solvation medium effect and the surface charge density of the weak base at the interface. The surface charge density at the interface is determined by the degree of head group ionization (pH effect) and ionic strength (electrostatic screening effect) (Drummond et al., 1989).

[0324] The pH range in which the phase transition occurs depends on both the molecular structure of the amino lipid and its doping level in the MO nanoparticles. For lipid 10, the desirable phase transition from H at a higher pH of 7.5 2 to Q at pH 5.5 2 was observed in the concentration range R MO = 0.4 - 0.5, and a further decrease to pH 4.0 resulted in liposome formation. For lipid 11 with R MO = 0.4 - 0.5, the transition from L 2 to Q 2 was observed at pH 3.0. For lipid 12, as the pH was decreased, a mixing of L 3 with weekly ordered Q 2 was brought about, and as the pH was further reduced to the L α phase 。 For lipid 13, at R MO = 0.2 - 0.3, the desirable H 2 → Q 2 transition was observed at pH 7.0, and the system appeared to be very sensitive, with the change from H 2 to Q 2 being observed within a difference of 0.5 pH units. It should be noted that there is a wide region in the phase diagram for the system with lipid 13 where the intermediate phase cannot be determined (denoted as N / D). For these samples, phase identification was precluded because the scattering peaks were either too weak or not found.

[0325] The results showed that the ionizable amino lipids studied promoted the formation of the H 2 phase in MO nanoparticles at neutral pH. However, at acidic pH, the amino lipids are gradually protonated, and the electrostatic repulsion between the protonated head groups at the lipid-water interface reduces the surface curvature. As a result, the decrease in pH induces a phase transition, which is thought to convert hexosomes to cubosomes under acidic conditions. Of the four exemplary amino lipid-MO nanoparticle systems, two of these, namely lipid 10 and lipid 13, exhibit pH-dependent H 2 →Q 2 phase transitions at pH values (pH 5.0 to pH 6.5) that are pathologically relevant for solid tumors.

[0326] (c) Effect of temperature on the mesophase structure of amino lipid-containing MO nanoparticles The lyotropic liquid crystal phase is temperature-dependent, and thus, to evaluate the final outcome of the nanoparticles at body temperature, SAXS experiments were also performed at 37 °C to study and compare the phase behavior of the nanoparticles at 25 °C and 37 °C. For this purpose, a formulation with lipid 10 that exhibited H 2 at pH 7.5 and transitioned to Q 2 at lower pH, with an R MO of 0.4 was selected. One-dimensional SAXS profiles for nanoparticles at pH 4.0 to pH 7.5 are shown in Figure 5. It is clear from the SAXS profiles that temperature has a minor effect on the mesophase structure of the amino lipid-doped nanoparticles. At 37 °C, the phase transition from H 2 to Q 2 is 0.5 pH unit higher compared to the phase transition at 25 °C. Nevertheless, both systems are qualified for loading the active drug using the drug SN-38 and were further investigated for drug loading, encapsulation efficiency (EE), and drug release studies.

[0327] Example 5: Preparation of LLC lipid nanoparticles containing an active drug The LLC lipid carriers disclosed herein, such as the LLC lipid nanoparticles disclosed herein, can contain active agents such as chemotherapeutic agents, cosmetically active molecules, or nucleic acids. In the following examples, the potent anticancer agent SN-38 was used as the active agent.

[0328] First, a drug-containing formulation was prepared by preparing a dried lipid mixture of MO and amino lipid as described in Example 2 above. Solid SN-38 was added to the dried lipid mixture (20 mg). The resulting mixture was heated at 60 °C overnight. The resulting mixture was mixed for 2 minutes using a vortex mixer and then an aqueous solution of Pluronic F-127 (2 mg / ml) was added. The subsequent mixture was probe sonicated for 5 minutes in pulse mode (Ranneh et al., 2016).

[0329] Results In this example, 1, 2, 5, or 10 wt% of SN-38 relative to the total amount of the lipid mixture in the formulation was added to pH-responsive MO nanoparticles containing lipid 10 (R MO = 0.4) to prepare four formulations with different amounts of SN-38.

[0330] Some precipitate was observed especially at 5 wt% and 10 wt%, but visual observation of the formed formulations suggested that the formulations were well dispersed.

[0331] Example 6: Particle Size and Polydispersity Index of LLC Lipid Nanoparticles Containing Active Agents The SN-38-containing lipid nanoparticles prepared as described in Example 5 above were studied for their physicochemical properties.

[0332] Results Each of the four lipid nanoparticle formulations was investigated for its particle size and polydispersity index (PDI) as described in Example 3 above, and the results are shown in Figure 6.

[0333] The particle size of the drug-loaded formulation was in the range of 244 - 274 nm with a PDI of 0.19 - 0.26. Generally, as more SN-38 was added to the system, the particle size increased slightly and gradually. Carsado et al. reported that the lipid / drug molar ratio strongly affects the size and amount of SN-38 within the vesicles, and a significant increase in liposome size was observed for a novel microfluidic liposome formulation for SN-38 delivery (Carsado et al., 2018). However, for the formulation with lipid 10, the increase in the average particle size was about 10 - 15%, and these are suitable for delivering SN-38.

[0334] Example 7: Phase behavior of LLC lipid nanoparticles containing an active agent The mesophase structure of each of the SN-38 containing lipid nanoparticle formulations prepared as described in Example 5 was determined over a pH range.

[0335] Results As described previously in Example 4, SAXS experiments were performed to study the internal mesophase structure in response to pH in the range of 2.5 - 8 at 25 °C (data not shown) and 37 °C. The partial phase diagram at 37 °C is presented in Figure 7 and compared to the formulation without drug.

[0336] SAXS experiments were performed on the drug-loaded formulations to see the effect of drug loading on the mesophase behavior and compared these to the formulations without drug. It was interesting to note that all the drug-loaded formulations behaved slightly differently from the drug-free controls. For the formulations with 1, 2, and 5 wt%, the H 2 →Q 2 phase transition occurred at pH 5.0. At a ratio of 10 wt%, the coexistence phase window of the (X + H 2 ) drug-loaded formulation was observed at pH 5.5, where X was not a distinguishable phase and was probably a weak scattering Q 2 phase. The complete transition to the Q 2 phase occurred at pH 5.0. Slightly higher H 2 →Q 2The transfer pH can be explained by the study conducted by Casado et al. on the interaction between the SN-38 drug and the biomembrane model, which reported that SN-38 was inserted into the hydrophobic core of the bilayer due to its highly hydrophobic nature and drug localization in the outer hydrophobic zone of the bilayer (Carsado et al., 2018). H 2 →Q 2 The fact that the phase transfer pH moves by 0.5 pH units is an additional advantage, and the results are positive because SN-38 can be inserted into the hydrophobic core of the mixed lipid bilayer without disturbing its structure or affecting the stability of the nanoparticles.

[0337] The SAXS results demonstrated that the drug loading did not change the mesophase structure at neutral pH and that the drug loading shifted the phase transition (H 2 →Q 2 )pH 0.5 units higher than the drug-free control.

[0338] Example 8: Drug Loading and Drug Encapsulation Efficiency of LLC Lipid Nanoparticles Containing Active Pharmaceutical Ingredients The drug loading (DL) and encapsulation efficiency (EE) were determined for each of the four formulations of Example 5 using the HPLC method.

[0339] The nanoparticles containing the drug were centrifuged at 1000×g for 25 minutes at 25 °C to remove any non-encapsulated drug agglomerates. The supernatant was collected and vortexed at 2500 rpm for 10 minutes for uniform distribution.

[0340] For the SN-38 drug content assay, a UV variable detector at a wavelength of 265 nm and an Agilent Zorbax SB-C18 column (4.6 mm × 250 mm, 5 μm) were utilized. The mobile phase was 25 mM NaH 2 PO 4(pH = 3.1) It consisted of a 50:50 (v / v) mixture of buffer and acetonitrile. The pH of the mobile phase was maintained at 3.8 to ensure that the analyte, SN-38, was in the closed lactone ring form during the assay. Samples for HPLC were prepared by diluting the nanoparticles 100-fold with HPLC solvent (10 μL of the formulation with 990 μL of a 50 / 50 mixture of buffer and acetonitrile). During the assay, an aliquot of 20 μL of the sample was injected into the HPLC system in duplicate at a flow rate of 1 mL / min. The SN-38 content in the formulation was quantitatively determined using a standard curve prepared as described in previously published academic papers (Zhang et al. 2004; Escoriaza et al. 2000).

[0341] The following formula:

Number

[0342] Formulations were prepared by adding 1, 2, 5, and 10 wt% of SN-38 to the total amount of the lipid mixture in the formulation. Unencapsulated free drug was removed from the formulation using centrifugation, and %EE was determined using HPLC as outlined previously. When 1 wt% of the drug was added to the formulation, an average %EE of 82% was found, indicating that most of the added drug was encapsulated in the bilayer and only a small amount of free unencapsulated drug was present. For drug loading with OAPy-4, it was observed that the higher the ratio of drug to lipid, the more the %EE decreased. Each drug has specific requirements for efficient and stable encapsulation in lipid nanoparticles.

[0343] Results The DL and EE% for the SN-38-loaded formulations are shown in Table 3 and Figure 8. The data in Table 3 representing the drug loading and %EE of samples prepared by adding 1, 2, 5, and 10 wt% of SN-38 to the total amount of the lipid mixture in the formulation (MO + OAPy-4) and dispersed with F-127 were triplicated for three independently prepared SN-38-loaded formulations, and all values are represented as mean ± SD (n = 3).

Table 4

[0344] A high loading of 844 μg / ml of SN-38 was achieved, which is approximately 100 times the solubility of SN-38 in water. A prior study conducted by Ranneh et al. loaded SN-38 in phytantriol-based cubosomes with a surfactant to increase solubility and used a cationic surfactant to achieve a high-loading formulation of SN-38 at a loading of 90 - 120 μg / ml (Ranneh et al., 2016). Compared to the study conducted by Ranneh, this formulation with ionizable amino lipids is loaded approximately 8-fold more.

[0345] The dynamic properties of the bilayer can significantly impede or promote the incorporation of hydrophobic molecules such as SN-38. Carriers with a rigid bilayer have obvious advantages such as low permeability and stability in vivo, but these have many drug loading limitation problems. In contrast, fluid bilayers more readily accommodate hydrophobic molecules within their hydrophobic cores. For drug loading with Lipid 10, it was observed that the higher the ratio of drug to lipid, the lower the %EE. Each drug has specific requirements for efficient and stable encapsulation in nanoparticles. Among these, many factors contribute to the success of the final formulation, such as the lipid composition, as well as the manufacturing process that determines size, surface charge, and bilayer fluidity (Bala et al., 2013). Loading is pH-dependent, and nanoparticles prepared with PBS buffer were observed to have better loading than those prepared with DI water. As the pH increases, SN-38 undergoes a structural change from a closed lactone ring to an open-ring carboxylate form, and since both forms are in equilibrium at pH 6.7, higher loading with PBS may be possible. The open-ring carboxylate form is water-soluble and is thus incorporated into the water channels along with the bilayer and higher drug loading. The efficiency of drug loading depends on its encapsulation into the aqueous core, its incorporation into the bilayer, or its partitioning between these two phases.

[0346] Overall, the results indicate that the novel LLC lipid nanoparticles disclosed herein enable high drug loading of the drug SN-38.

[0347] Example 9: Drug Release Study The in vitro release of SN-38 from the nanoparticles was evaluated using the dynamic dialysis method (Zambito, Y. International Journal of Pharmaceutics 2012, 434(1), 28 - 34). The drug release rate was determined by placing the dispersion within a dialysis tube (Pur-A-Lyzer® Maxi Dialysis Tube molecular weight cut-off 3500) and thoroughly dialyzing it.

[0348] After removing the free drug, the highest SN-38-loaded nanoparticles (1 mL of formulation) were placed inside a dialysis tube. The dialysis tube was then immersed in 1000 mL of buffer maintained at 37 ± 1.0 °C and stirred at 400 rpm. The analysis of the separation of free drug from the drug-loaded formulation was carried out over a period of 420 minutes. The release experiments were performed in triplicate on three independently prepared SN-38-loaded formulations. For physiological pH, the experiments were conducted by dialyzing the formulation against 1000 mL of phosphate buffer (pH 7.0). The experiments at lower pH were conducted by dialyzing the formulation against 1000 mL of phosphate buffer adjusted to the required pH. The SN-38 remaining in the dialysis tube was quantitatively measured by HPLC. At predetermined time intervals (60 minutes, 120 minutes, 240 minutes, and 420 minutes), 10 μL of the sample was removed from the dialysis tube and diluted with 990 μL of HPLC solvent. A protocol for predicting the release kinetics from the recovery of samples from inside the dialysis bag is described in the literature.

[0349] Results Calibration experiments for drug diffusion through the dialysis membrane without the lipid nanocarrier drug delivery vehicle were carried out to evaluate the effect of the dialysis membrane on the release kinetics. More than 90% of SN-38 was released from the pure drug suspension within 60 - 90 minutes (data not shown here), and thus any membrane effect was negligible regarding the drug release kinetics.

[0350] The release profiles of SN-38 from SN-38-lipid 10 nanoparticles at different pH values are shown in Figure 9. The SN-38-lipid 10 formulation showed a burst release (about 37%) during the first 60 minutes of the study for both the studied pHs (7.0 and 5.0) and a sustained release after the first hour. In the dialysis setup, the sink condition was maintained at 10 - 20 times the volume required for a saturated drug solution so that the free drug could rapidly equilibrate across the dialysis membrane. Since the water solubility of SN-38 is 7 - 11 μg / mL, 1000 mL of sink solution was used for 1 mL of the formulation. This 1000-fold dilution increased the diffusion-controlled drug release rate by orders of magnitude, resulting in an apparent burst release of SN-38.

[0351] After the first hour of the study, the drug release rate from the sample at pH = 5.0 was faster compared to the sample at pH = 7.0. This difference in the sustained release behavior is consistent with the presence of different mesophases (inverse hexagonal or cubic phases) under different pH conditions. The cubic phase with two interpenetrating water channels that are likely to be open to the external aqueous phase provides more surface area and more available pathways for drug release. On the other hand, the hexagonal phase with a closed columnar micelle structure hinders drug release. Drug release from the continuous cubic phase network with large open channels is faster than from the hexagonal phase-filled channels with smaller diameters.

[0352] Previous in vitro and in vivo studies have shown that varying the release rate is one of the possible approaches to increase drug distribution to tumors and improve the anti-tumor effect of drugs. The release results of SN-38-lipid 10 nanoparticles reveal a slower drug release rate in the simulated normal cell physiological environment (pH = 7.4) and a faster release rate in the simulated tumor microenvironment and lysosomal environment (pH = 5.0). The slower release rate at pH 7.4 may be potentially beneficial as it may lead to a reduction in drug loss during circulation and an increase in the bioavailability of the drug at the tumor site. The faster release rate at pH = 5.0 is beneficial as it leads to an accumulation of the drug in the pathological environment with a reduction in the cytotoxicity of SN-38 and an improvement in efficacy for healthy cells.

[0353] The results indicate that the novel LLC lipid nanoparticles disclosed herein enable the controlled release of the drug SN-38 in response to pH.

[0354] Example 10: In Vivo Toxicity Study of LLC Lipid Nanoparticles The in vivo toxicity of the LLC lipid nanoparticles disclosed herein was evaluated in mice.

[0355] Nanoparticles were prepared using the above evaporation and sonication methods with amino lipids OAPi-1 and OAPy-4, and monoolein (MO) as the structural lipids.

Chemical formula

[0356] Briefly, the lipids were dissolved in ethanol at an appropriate ratio. The ratios of MO:OAPi-1 were 75:25 and 85:15 (weight:weight). The ratio of MO:OAPy-4 was 60:40. The solvent was evaporated overnight in a vacuum oven at 40 °C. An aqueous solution containing Pluronic F-127 was added to the dried lipid mixture. The ratio of F-127 to the lipids was kept constant at 1:10 (weight / weight). The solution was sonicated using a probe sonicator to generate stable nanoparticles.

[0357] Six-week-old Balb / c nude mice were intraperitoneally injected with the formulated nanoparticles at the specified doses (50, 100, and 200 mg / kg). The mice were monitored for adverse effects over 24 hours.

Table 5

[0358] The results showed that at the tested concentrations, the nanoparticles did not show adverse effects after 24 hours. This experiment suggests that the nanoparticles do not cause acute toxicity in mice. It is also suggested that the maximum tolerated dose is above 200 mg / kg.

[0359] The results indicate that the novel LLC lipid nanoparticles disclosed herein are suitable for clinical applications as pharmaceutical or cosmetic drug carriers.

[0360] Those skilled in the art will understand that numerous variations and / or modifications can be made to the above embodiments without departing from the broad general scope of the present disclosure. Accordingly, the present embodiments are to be considered in all respects as illustrative and not restrictive.

[0361] References Bala, V.; Rao, S.; Boyd, B. J.; Prestidge, C. A., Prodrug and nanomedicine approaches for the delivery of the camptothecin analogue SN38. J Control Release 2013, 172(1), 48 - 61. Casado, A.; Sagrista, M. L.; Mora, M., A novel microfluidic liposomal formulation for the delivery of the SN - 38 camptothecin: characterisation and in vitro assessment of its cytotoxic effect on two tumor cell lines. Int J Nanomedicine 2018, 13, 5301 - 5320. Drummond, C. J.; Grieser, T. F.; Healy, T. W., Acid - Base Equilibria in Aqueous Micellar Solutions. Journal of the Chemical Society, Faraday Transactions 1. 1989, 85(3), 521 - 535. Escoriaza, J.; Castellanos, A. A. C.; Calvo, E.; Giraldez, J. Simple and rapid determination of Irinotecan and its metabolite SN-38 in plasma by high-performance liquid-chromatography: application to clinical pharmacokinetic studies. Journal of Chromatography B, 2000, 740(2000)159 - 168. Rajesh, S.; Zhai J.;, Drummond, C. J., Tran, N. Synthetic ionizable aminolipids induce a pH dependent inverse hexagonal to bicontinuous cubic lyotropic liquid crystalline phase transition in monoolein nanoparticles. Journal of Colloid and Interface Science, 2021, Volume 589, 85 - 95. Ranneh, A. H.; Iwao, Y.; Noguchi, S.; Oka, T.; Itai, S. The use of surfactants to enhance the solubility and stability of the water-insoluble anticancer drug SN38 into liquid crystalline phase nanoparticles. Int J Pharm 2016, 515(1 - 2), 501 - 505. Sarkar, S.; Tran, N.; Rashid, M. H.; Le, T. C.; Yarovsky, I.; Conn, C. E.; Drummond, C. J. Toward Cell Membrane Biomimetic Lipidic Cubic Phases: A High-Throughput Exploration of Lipid Compositional Space. ACS Applied Bio Materials 2018, 2(1), 182 - 195. Tran, N.; Hawley, A. M.; Zhai, J.; Muir, B. W.; Fong, C.; Drummond, C. J.; Mulet, X., High-Throughput Screening of Saturated Fatty Acid Influence on Nanostructure of Lyotropic Liquid Crystalline Lipid Nanoparticles. Langmuir 2016, 32(18), 4509 - 4520. Tran, N.; Hocquet, M.; Eon, B.; Parveen Sangwan; Ratcliffe, J.; Hinton, T. M.; White, J.; Ozcelik, B.; Reynolds, N. P.; Muir, B. W., Non-Lamellar Lyotropic Liquid Crystalline Nanoparticles Enhance the Antibacterial Effects of Rifampicin against Staphylococcus Aureus. Journal of colloidal and interface Science 2018, 519(1), 107 - 118. Tran, N.; Mulet, X.; Hawley, A. M.; Hinton, T. M.; Mudie, S. T.; Muir, B. W.; Giakoumatos, E. C.; Waddington, L. J.; Kirbyb, N. M.; Drummond, C. J., Nanostructure and cytotoxicity of self-assembled monoolein-capric acid lyotropic liquid crystalline nanoparticles. Royal Society of Chemistry Advances 2015, 5(34), 26785-26795. Zhai, J.; Hinton, T. M.; Waddington, L. J.; Fong, C.; Tran, N.; Mulet, X.; Drummond, C. J.; Muir, B. W., Lipid-PEG conjugates sterically stabilise and reduce the toxicity of phytantriol-based lyotropic liquid crystalline nanoparticles. Langmuir 2015, 31(39), 10871-10880. Zhang, J. A.; Xuan, T.; Parmar, M.; Ma, L.; Ugwu, S.; Ali, S.; Ahmad, I., Development and characterisation of a novel liposome-based formulation of SN-38. Int J Pharm 2004, 270(1-2), 93-107.

Claims

1. A lyotropic liquid crystal (LLC) lipid carrier comprising a structural lipid that is a lyotropic liquid crystal phase forming lipid and an amino lipid having an amide linker, wherein the LLC lipid carrier is adapted to undergo an intermediate phase transition when exposed to a decrease in pH.

2. The structural lipid can form a cubic intermediate phase structure, and / or The LLC lipid carrier according to claim 1, wherein the structural lipid comprises a hydrophobic tail group selected from the group consisting of oleyl, linoleoil, linolenoyl, phytanoyl, farnesoyl, or an elongated aliphatic hydrophobic substance, optionally selected from oleyl, linoleoil, and phytanoyl.

3. The LLC lipid carrier according to claim 1, wherein the structural lipid is monoolein (glycerol monooleate).

4. The amino lipids are present in a weight percentage of the total lipid content of the LLC lipid carrier, and / or are suitable for inducing the intermediate phase transition when exposed to a decrease in pH. The LLC lipid carrier according to any one of claims 1 to 3, wherein the amino lipid accounts for about 5% to about 50% by weight of the total lipid content of the LLC lipid carrier.

5. The amino lipids are defined by formula (I): Cycle-L-R (I) [In the formula, Cyc is a nitrogen heterocycle or heteroaryl, L is an amide linker, R has a structure in which C10-C44 carbon chains, and / or The aforementioned amino lipid is given by formula (Ib): 【Chemistry 1】 [In the formula, Cyc is a 5-membered or 6-membered nitrogen heterocyclyl or heteroaryl optionally selected from the group consisting of pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholinyl, and pyrazinyl.] R is a C10-C44 carbon chain, optionally a C12-C24 alkyl or alkenyl, optionally interrupted by one or more heteroatoms. An LLC lipid carrier according to any one of claims 1 to 3, having the structure [where n is an integer from 1 to 6].

6. The LLC lipid carrier according to claim 5, wherein R is selected from the group consisting of oleyl, linoleoyl, linolenoyl, phytanoyl, and farnesoyl.

7. The aforementioned amino lipids 【Chemistry 2】 An LLC lipid carrier according to any one of claims 1 to 3, selected from the group consisting of [wherein R is as defined in claim 5].

8. The LLC lipid carrier according to any one of claims 1 to 3, wherein the LLC lipid carrier further comprises a stabilizer, wherein the stabilizer is optionally a stabilizing polymer, or optionally a nonionic triblock copolymer.

9. The LLC lipid carrier according to claim 8, wherein the stabilizer is present in an amount of about 10% by weight of the total lipid content of the LLC lipid carrier, and / or the stabilizer is Pluronic F127 (Poloxamer 407) or Poloxamer 80.

10. The LLC lipid carrier according to any one of claims 1 to 3, wherein the LLC lipid carrier is in the form of lyotropic liquid crystal (LLC) nanoparticles.

11. The LLC lipid carrier according to any one of claims 1 to 3, wherein the intermediate phase transition when exposed to a decrease in pH is a transition from a hexagonal phase to a cubic phase.

12. The LLC lipid carrier contains a hexagonal lyotropic liquid crystal phase structure at a pH of approximately 7 or higher, optionally at a pH of approximately 7.4 or higher, or The LLC lipid carrier contains a cubic lyotropic liquid crystal phase structure at a pH of approximately 4.0 to 7.0, or The LLC lipid carrier according to claim 11, wherein the LLC lipid carrier comprises a hexagonal lyotropic liquid crystal phase structure at a pH of approximately 7 or higher, optionally at a pH of approximately 7.4 or higher, and a cubic lyotropic liquid crystal phase structure at a pH of approximately 4.0 to 7.

0.

13. The LLC lipid carrier according to claim 1, further comprising an active agent, wherein the active agent is optionally pharmaceutically or cosmetically active.

14. The active agent is selected from the group consisting of peptides, proteins, enzymes, small molecule drugs, and nucleic acids, and optionally the active agent is selected from the group consisting of radionuclides, contrast agents, polymers, antibiotics, fungicides, metal-containing nanoparticles, anti-inflammatory agents, antitumor agents, cardiovascular agents, anxiolytics, hormones, growth factors, steroids, gene expression modifiers, knockdown agents, siRNA, RNAi agents, mRNA, DNA, Dicer substrates, miRNA, shRNA, antisense oligonucleotides, aptamers, and microbial toxins, and / or The LLC lipid carrier according to claim 13, wherein the active agent is a topoisomerase I inhibitor optionally selected from camptothecin, irinotecan, and SN-38.

15. The LLC lipid carrier according to claim 1, wherein the LLC lipid carrier has a water content of about 20 to about 60% by weight.

16. A lyotropic liquid crystal (LLC) lipid nanoparticle composition, which is a dispersion of the LLC lipid carrier described in claim 13 in a polar medium.

17. A pharmaceutical composition comprising an LLC lipid carrier according to any one of claims 13 to 15, or an LLC lipid nanoparticle composition according to claim 16, and a pharmaceutically acceptable carrier, diluent, and / or excipient.

18. The pharmaceutical composition according to claim 17, formulated as a composition for injection, topical administration, or subcutaneous administration.

19. A pharmaceutical composition for treating or preventing a disease, disorder, or condition in a mammal, comprising a therapeutically effective amount of the LLC lipid carrier described in claim 13 or the LLC lipid nanoparticle composition described in claim 16.

20. The pharmaceutical composition according to claim 19, wherein the disease, disorder, or condition is cancer or a bacterial or fungal infection.

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