Use of nanoparticles in therapeutic and imaging methods

Abstract

The invention provides nanoparticles for use in therapeutic and imaging methods, as well as related methods, compositions, and kits.

Description

[0001] Use of Nanoparticles in Therapeutic and Imaging Methods

[0002] Background of the Invention

[0003] Advances in the development of cancer therapies have led to increased life expectancies that could only have been imagined in the past. These advances, however, have also resulted in increased prevalence of long-term side effects of cancer therapies in patients. Such long-term side effects include, for example, cardiotoxicity, fatigue, cognitive issues, reduced lung capacity, kidney and urinary problems, nerve damage, hearing loss, bone and joint problems, dental problems, muscle weakness, and secondary cancers. In some instances, the side-effects can be just as, if not more, devastating than the cancer itself. As just an example, chemotherapy-induced cardiotoxicity is prevalent and deadly, with no effective therapy to slow progression to irreversible heart failure which, in the case of doxorubicin-induced cardiotoxicity, can reach 50% mortality.

[0004] There is a need for the development of therapies for long-term side effects of cancer treatment, including cardiotoxicity.

[0005] Summary of the Invention

[0006] The invention provides methods of preventing, treating, or reducing cardiotoxicity in a subject resulting from treatment with a therapy causing cardiotoxicity, the methods comprising administering acidifying nanoparticles (NPs) to the subject, wherein the NPs are derivatized with peptides.

[0007] In some embodiments, the nanoparticles are poly(lactic-co-glycolic acid) (PLGA), poly(lactic acid) (PLA), poly(glutamic acid) (PLG), polycaprolactone (PCL), or polyester nanoparticles.

[0008] In some embodiments, the nanoparticles are PLGA nanoparticles, wherein optionally the PLGA is present in pure D-form, pure L-form, or a mixture of D- and L-forms.

[0009] In some embodiments, the PLGA nanoparticles have lactic acid to glycolic acid ratios of, e.g., 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, or 85:15.

[0010] In some embodiments, the nanoparticles have at least one dimension (e.g., a diameter) within the range of 1 -1000 nm (e.g., 50-900, 100-750, 150-600, or 200-500), including any integer value between 1 nm and 1000 nm (including about 1 , 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 500, 600, 700, 800, 900, and 1000, or ranges between any of these values, or have at least one dimension (e.g., a diameter) that is no more than 1 pm.

[0011] In some embodiments, the PLGA nanoparticles comprise multi-arm PLGA molecules.

[0012] In some embodiments, the multi-arm PLGA molecules comprise 4, 6, or 8 arms.

[0013] In some embodiments, the molar ratio of PLGA to peptide is less than 1 :x, wherein x is the number of arms.

[0014] In some embodiments, the multi-arm PLGA comprises 8 arms and the molar ratio of PLGA to peptide is less than 1 :8 (e.g., 1 :1 , 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, or 1 :7).

[0015] In some embodiments, the peptides are positively charged under physiological conditions.

[0016] In some embodiments, the peptides comprise 2 to 50 amino acids, 2 to 30 amino acids, 2 to 20 amino acids, 2 to 10 amino acids, 2 to 5 amino acids, 3 amino acids, or 4 amino acids. In some embodiments, the peptides are arginine-containing (e.g., arginine-rich) peptides that are positively charged under physiological pH and further optionally wherein the peptides are capable of traversing the plasma membrane of eukaryotic cells.

[0017] In some embodiments, the peptides are Arg4 peptides.

[0018] In some embodiments, the peptides are covalently linked to the nanoparticles.

[0019] In some embodiments, the peptides are covalently linked to the nanoparticles by click chemistry, wherein optionally the linkage comprises dibenzocyclooctyne (DBCO), and / or wherein optionally the linkage comprises polyethylene glycol (PEG) (e.g., 1k or 5k) between the DBCO and a PLGA arm.

[0020] In some embodiments, the nanoparticles comprise a detectable label.

[0021] In some embodiments, the detectable label is attached to the nanoparticle via the peptide, e.g., at the N-terminal end of the peptide or at the C-terminal end of the peptide.

[0022] In some embodiments, the detectable label is fluorescent.

[0023] In some embodiments, the nanoparticles comprise polyethylene glycol.

[0024] In some embodiments, the subject does not have, but is at risk of developing, cardiotoxicity.

[0025] In some embodiments, the subject has one or more symptoms of cardiotoxicity.

[0026] In some embodiments, the acidifying nanoparticles do not comprise or are not covalently linked to a therapeutic agent, such as an anti-cancer agent, wherein optionally the therapeutic agent causes cardiotoxicity.

[0027] In some embodiments, the therapy causing cardiotoxicity is an anti-cancer therapy.

[0028] In some embodiments, the subject has been, is currently, or will be under treatment with an anticancer therapy selected from the group consisting of chemotherapy, radiation therapy, immunotherapy, targeted therapy, and hormone therapy.

[0029] In some embodiments, the therapy comprises treatment with an anticancer agent selected from one or more of the group consisting of anthracyclines, HER2-targeted agents, tyrosine kinase inhibitors, angiogenesis inhibitors, platinum-based chemotherapy agents, microtubule inhibitors, antimetabolites, alkylating agents, proteasome inhibitors, and lupeol.

[0030] In some embodiments, (a) the anthracycline is selected from the group consisting of doxorubicin, mitoxatrone, epirubicin, idarubicin, and daunorubicin; (b) the HER2-targeted agent is selected from the group consisting of trastuzumab, lapatinib, pertuzamab, and ado-trastuzumab emtasine; (c) the tyrosine kinase inhibitor is selected from the group consisting of sunitinib, sorafenib, axitinib, imatinib, and osimertinib; (d) the angiogenesis inhibitor is selected from the group consisting of bevacizumab, thalidomide, and cannabinoids; (e) the platinum-based chemotherapy agent is selected from the group consisting of cisplatin, oxaliplatin, and carboplatin; (f) the microtubule inhibitor is selected from taxanes, such as paclitaxel and docetaxel; (g) the antimetabolite is selected from the group consisting of 5- fluorouricil, capecitabine, cytarabine, gemcitabine, methotrexate, and hydroxyurea; (h) the alkylating agent is cyclophosphamide; or (i) the proteasome inhibitor is selected from the group consisting of bortezomib and carfilzomib.

[0031] In some embodiments, the anticancer therapy is an immunotherapy selected from the group consisting of a chimeric antigen receptor (CAR) T cell therapy, adoptive cell transfer therapy, or a monoclonal antibody. In some embodiments, (a) the chimeric antigen receptor (CAR) T cell therapy is selected from the group consisting of tisagenlecleucel and axicabtagene ciloleucel; or (b) the monoclonal antibody is selected from the group consisting of a monoclonal antibody targeted against VEGF, HER2, CTLA-4, PD1 and PD-L1.

[0032] In some embodiments, the subject has or is at risk of developing one or more of: heart failure (e.g., congestive heart failure), cardiomyopathy (e.g., dilated, hypertrophic, or restrictive cardiomyopathy), arrhythmias (e.g., QT interval prolongation or atrial fibrillation), conduction abnormalities, hypertension, myocardial ischemia, thromboembolism, coronary artery disease, pulmonary edema, left ventricular dysfunction, myocarditis, cardiogenic shock, pericarditis, pericardial effusion, valvular (e.g., mitral or aoritic) stenosis and / or regurgitation, ventricular tachycardia, sinus bradycardia, atrioventricular block, arteritis, and ischemia. These conditions can be diagnosed or monitored using standard methods in the art including, e.g., radionuclide ventriculography, positron emission tomography (PET), cardiac magnetic resonance (CMR), echocardiography, or biomarker (e.g., troponin, cardiac natriuretic peptides, or myeloperoxidase) detection.

[0033] In some embodiments, the therapy causing cardiotoxicity is an anti-HIV therapy; anti-malarial therapy, such as chloroquine or hydroxychloroquine; antifungal therapy, such as amphotericin B, or antiParkinson therapy, such as bromocriptine.

[0034] The invention further provides kits comprising acidifying nanoparticles (NPs) and a drug that causes cardiotoxicity, wherein the NPs are derivatized with peptides.

[0035] In some embodiments, the drug that causes cardiotoxicity is an anti-cancer drug.

[0036] In some embodiments, the acidifying nanoparticle comprises PLGA NPs.

[0037] In some embodiments, the anti-cancer agent is selected from one or more of the group consisting of anthracyclines, HER2-targeted agents, tyrosine kinase inhibitors, angiogenesis inhibitors, platinumbased chemotherapy agents, microtubule inhibitors, antimetabolites, alkylating agents, proteasome inhibitors, and lupeol.

[0038] In some embodiments, (a) the anthracycline is selected from the group consisting of doxorubicin, mitoxatrone, epirubicin, idarubicin, and daunorubicin; (b) the HER2-targeted agent is selected from the group consisting of trastuzumab, lapatinib, pertuzamab, and ado-trastuzumab emtasine; (c) the tyrosine kinase inhibitor is selected from the group consisting of sunitinib, sorafenib, axitinib, imatinib, and osimertinib; (d) the angiogenesis inhibitor is selected from the group consisting of bevacizumab, thalidomide, and cannabinoids; (e) the platinum-based chemotherapy agent is selected from the group consisting of cisplatin, oxaliplatin, and carboplatin; (f) the microtubule inhibitor is selected from taxanes, such as paclitaxel and docetaxel; (g) the antimetabolite is selected from the group consisting of 5- fluorouricil, capecitabine, cytarabine, gemcitabine, methotrexate, and hydroxyurea; (h) the alkylating agent is cyclophosphamide; or (i) the proteasome inhibitor is selected from the group consisting of ortezomib and carfilzomib.

[0039] In some embodiments, the anticancer agent is an immunotherapy selected from the group consisting of a chimeric antigen receptor (CAR) T cell therapy, adoptive cell transfer therapy, or a monoclonal antibody.

[0040] In some embodiments, (a) the chimeric antigen receptor (CAR) T cell therapy is selected from the group consisting of tisagenlecleucel and axicabtagene ciloleucel; or (b) the monoclonal antibody is selected from the group consisting of a monoclonal antibody targeted against VEGF, HER2, CTLA-4, PD1 and PD-L1.

[0041] In some embodiments, the acidifying nanoparticles do not comprise or are not covalently linked to an anti-cancer agent or any therapeutic associated with cardiotoxicity.

[0042] The invention further provides nanoparticles (e.g., PLGA nanoparticles) derivatized with peptides.

[0043] In some embodiments, the nanoparticle further comprises labels (e.g., fluorescent labels) that are linked to the nanoparticle by the peptides.

[0044] In some embodiments, the labeled peptides are linked to the nanoparticle using click chemistry, e.g., optionally wherein the linkage comprises DBCO and / or PEG (e.g., 1 k or 5k).

[0045] In some embodiments, the labels comprise a fluorophore linked to the PLGA nanoparticle through an -(Arg4)- peptide.

[0046] In some embodiments, the fluorophore is Cyanine5.5.

[0047] The invention further provides methods for medical imaging, the method comprising administering a nanoparticle described herein to a subject and detecting the presence of the nanoparticle in a tissue or organ of the subject.

[0048] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to,” and they are not intended to (and do not) exclude other moieties, additives, components, integers, or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0049] Brief Description of the Drawings

[0050] Figures 1 A-1 C provide information regarding the synthesis and characterization of functionalized PLGA NPs. The schematics in Figure 1 A are not drawn to scale.

[0051] Figures 2A-2H provide data relating to PLGA uptake and cytoprotective effects in cardiomyocyte H9C2 cells in vitro.

[0052] Figures 3A-3C provide data relating to PLGA uptake in mouse hearts in vivo.

[0053] Figures 4A-4E provide data showing the effects of PLGA treatment in mouse hearts after doxorubicin treatment.

[0054] Figure 5 provides information regarding an alternative synthesis of functionalized PLGA NPs. The schematics are not drawn to scale.

[0055] Figures 6A and 6B provide data showing the payload of fluorescent poly-arginine peptide functionalized PLGA nanoparticles.

[0056] Figure 7 provides data showing the effects of PLGA functionalized with Arg4-Cy5.5 peptide on cardiac cell survival after doxorubicin treatment.

[0057] Figures 8A-8E provides data showing that PLGA functionalized with Arg4-Cy5.5 peptide reduced cardiac apoptosis in doxorubicin-injected mice in vivo. Detailed Description

[0058] The invention provides methods for preventing, treating, or reducing cardiotoxicity that may occur, for example, in response to therapy (e.g., cancer, human immunodeficiency virus (HIV), or other therapy causing cardiotoxicity) or other cardiac injury. The invention is based, at least in part, on the present discovery that peptide-derivatized nanoparticles (NPs) can be used to decrease lysosomal pH in cells of the heart, and that this decrease leads to alleviation of cardiotoxicity, including, e.g., restoration to baseline. The methods of the invention involve the administration of peptide-derivatized NPs, such as a poly(lactic-co-glycolic acid) (PLGA) NPs (also see below) that are derivatized with peptides, as explained further below. The invention also provides peptide-derivatized NPs (e.g., peptide-derivatized PLGA NPs), as well as methods of using such NPs in imaging methods. The methods and NPs of the invention are described further, as follows.

[0059] Nanoparticles (NPs)

[0060] Nanoparticles (NPs) that can be used in the invention include those that are characterized by their ability to acidify lysosomes within cells. Examples of such NPs include poly(lactic-co-glycolic) acid (PLGA) NPs, which advantageously are biocompatible and have well-defined pharmacokinetic properties for human use. PLGA is a copolymer of glycolic acid and lactic acid that is used in many FDA-approved therapeutic products. Poly-lactic acid contains an asymmetric a-carbon, and thus can be poly D-lactic acid or poly L-lactic acid. In general, the term “PLGA” herein is used to describe poly D,L-lactic-co- glycolic acid, where the D- and L-lactic acid forms are present as a mixture or in either pure D- or L- form. The present invention can thus employ PLGA in the pure D-form, the pure L-form, or a mixture of D- and L-forms. The invention also includes the use of PLGA in which the ratios of lactic acid and glycolic acid differ (e.g., 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, or 10:90), or PLGA in combination with another polymer (e.g., polyethylene glycol, PEG).

[0061] PLGA NPs can be characterized by features including, for example, the molar ratio of the components of the copolymers, the size of the copolymers, the size of the NPs, and the shape of the NPs. These features can be selected for use in the preparation of NPs by those of skill in the art. In nonlimiting examples, PLGA NPs that can be used in the invention include those made of PLGA having lactic acid to glycolic acid ratios of, e.g., 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, or 85:15. In additional, non-limiting examples, the PLGA NPs can be comprised of PLGA polymers of, e.g., 5,000- 100,000, 10,000-90,000, 20,000-80,000, 30,000-70,000, or 40,000-60,000 molecular weight. In more specific examples, the ranges may be, e.g., 20,000-50,000, 30,000-60,000, or 40,000-75,000 molecular weight. In further non-limiting examples, the NPs (e.g., PLGA NPs) have at least one dimension (e.g., a diameter) within the range of 1 -1000 nm (e.g., 50-900, 100-750, 150-600, or 200-500), including any integer value between 1 nm and 1000 nm (including about 1 , 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 500, 600, 700, 800, 900, and 1000, or ranges between any of these values). In some embodiments, the NPs (e.g., PLGA NPs) have at least one dimension (e.g., a diameter) that is no more than 1 pm. NP size can be determined using methods known in the art including, e.g., sedimentation field flow fractionation, photon correlation spectroscopy, disk centrifugation, and dynamic light scattering. Furthermore, nanoparticles used in the invention are typically spherical but, optionally, can be of a different shape, e.g., they can be rod-shaped, needle-shaped, or cylindrical. The NPs used in the methods of the invention can include PLGA as the only polymer component or, optionally, can also include, e.g., another polymer selected from, e.g., polyethylenes (e.g., polyethylene glycol (PEG)), poly(e-carbobenzoxy-L-Lysine)(PLL), poly(lactic acid) (PLA), poly(glycolic acid) (PLG), polycarbonates, polyanhydrides, polyhydroxyacids, polypropylfumerates, polycaprolactones, polyamides, polyacetals, polyethers, polyesters, poly(orthoesters), polycyanoacrylates, polyvinyl alcohols, polyurethanes, polyphosphazenes, polyacrylates, polymethacrylates, polyureas, polystyrenes, polyamines, or combinations thereof.

[0062] In the case of PLGA-containing nanoparticles, the PLGA can optionally be multi-armed. For example, the PLGA may comprise 2, 3, 4, 5, 6, 7, or 8 arms. In some embodiments, the molar ratio of the PLGA to peptide is less than 1 :x, wherein x is the number of arms. Thus, for example, in the case of 8- arm PLGA the molar ratio of 8-arm PLGA:peptide can be less than 1 :8 (e.g., 1 :7, 1 :6, 1 :5, 1 :4, 1 :3, 1 :2, 1 :1 or a range between any of these ratios). Thus, for example, the molar ratio of 8-arm PLGA:peptide can be 1 :1 , 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, or 1 :7, or within a range (e.g., 1 :1 -1 :4 or 1 :2-1 :4).

[0063] NPs, such as PLGA NPs, can be made using methods known in the art (see, e.g., Fessi et al., International Journal of Pharmaceutics 55(1 ):R1 -R4, 1989; Garinot et al., J Control Release 120(3):195- 204, 2007; Rezvantalab et al., Frontiers in Pharm. 9(1260), 2018; Makadia et al., Polymers (Basel) 3(3):1377-1397, 2011 ). These methods can include, for example, approaches utilizing emulsificationevaporation, salting-out, nanoprecipitation, and microfluidics-assistance (see, e.g., Rezvantalab et al., supra).

[0064] One specific example of a method for making PLGA NPs is provided as follows. Variations of the method, as well as altering of the scale of the preparation, can be carried out by those of skill in the art. PLGA nanoparticles can be prepared by first dissolving 5 mg of PLGA (24-38 kDa, purchased from Sigma-Aldrich, St. Louis, MO, USA) in 100 pl of THF (tetrahydrofuran) to make a clear solution. The PLGA solution is then added dropwise to 15 ml of deionized FLO with vigorous stirring. After 3-4 days of constant stirring at room temperature, the PLGA nanoparticles are dialyzed with 50 kDa membrane, or by Amicon size-exclusion cartridge with 50 kDa cutoff to remove THF from PLGA polymer. The purified PLGA nanoparticle solution is then lyophilized to determine yield and for long-term storage. An alternative, exemplary method, involving the use of DMSO in place of THF, and the covalent attachment of arginine-rich fluorescent peptides on multi-arm PLGA polymer is described below in Example 2.

[0065] As noted above NPs (e.g., PLGA NPs) used in the invention are functionalized (e.g., covalently functionalized) with one or more peptides. This can be done so that the NP can optionally be used for purposes in addition to acidifying lysosomes. In one example, derivatized NPs can be used in imaging techniques. Accordingly, such molecules can be used simultaneously as therapeutic and diagnostic molecules (i.e. , as theranostics). Furthermore, and as is noted in the Examples, below, we have found that derivatization can be advantageous with respect to the formation of smaller and more reproducible PLGA nanoparticles. Functionalized nanoparticles (e.g., fluorescent NPs) can be prepared using molecules and methods that are known in the art. In some examples, click chemistry is used to derivatize NPs. As one non-limiting example, a dibenzocyclooctyne (DBCO) linker can be used. In some examples, and as noted above, the PLGA used to make a PLGA NP is a multi (e.g., 4 or 8)-arm PLGA, which facilitates derivatization. In some examples, the derivatization includes functionalization by azide or amine (PLGA-NH2) groups. Furthermore, in some examples, the polymer (e.g., PLGA) arm is linked to the peptide via a linker, e.g., a DBCO linker, and the polymer (e.g., PLGA) arm is connected to the linker via polyethylene glycol (PEG), e.g., 1 k or 5k PEG. It should be understood that DBCO + N3 copper-free click chemistry is just an example of a click chemistry that can be used to link peptides to the NPs, according to the invention, and that other types of click chemistry can be used instead.

[0066] Peptides that are used to derivatize the NPs can be, e.g., 2-50, 2-40, 2-30, 2-20, 2-10, 3-20, 3- 10, 4-20, 4-10, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acids in length. In some embodiments, the peptides are positively charged under physiological pH (7.4). In some embodiments, the peptides comprise one or more positively charged amino acid, e.g., one or more of arginine, lysine, or histidine. In some embodiments, the peptides comprise at least 50% positively charged amino acids (e.g., at least 75%, 80%, 90%, or 100%). In some embodiments, the peptides comprise poly-arginine stretches or comprise only arginines (e.g., R2, R3, R4, R5, or R6, such as R4). Accordingly, in some embodiments, the peptides are arginine-containing peptides that are positively charged under physiological pH and are capable of traversing the plasma membrane of eukaryotic cells. In some embodiments, each of the peptides on a NP (or within a mixture of NPs) is identical. In other embodiments, the peptides are different from one another.

[0067] One specific example of a method for making derivatized PLGA NPs is as follows. Variations of the method, as well as altering of the scale of the preparation, can be carried out by those of skill in the art. Fluorescent PLGA nanoparticles are prepared with multi-arm PLGA with an azide functional group at the end of each arm (30 kDa; Nanosoft Polymers, Winston-Salem, NC, USA). Multi-arm PLGA is first dissolved in THF. Fluorescent poly-arginine Cy5.5 peptide containing DBCO (dibenzocyclooctyne) for copper-free click reaction is prepared in DMSO. Under vigorous stirring, fluorescent peptide is added in 5 increments to the PLGA under stirring, every 3 minutes. The click reaction is allowed to proceed to completion for 1 .5 hours at room temperature. After click reaction, functionalized PLGA nanoparticles are formulated and purified as above. An alternative method is described in Example 2 below.

[0068] T reatment

[0069] NPs of the invention can be administered in amounts and in regimens determined to be appropriate by those of skill in the art based on factors including, e.g., the condition to be treated, the health of the subject, or whether other agents will be co-administered. The NPs can be administered prophylactically, in order to prevent cardiotoxicity, or therapeutically, in order to treat or reduce cardiotoxicity. The NPs can be administered before, at the same time as, or after one or more other treatments that may cause or put a subject at risk of cardiotoxicity. The NPs can be administered as sole therapeutic agents or, alternatively, can be administered in combination with, e.g., anticancer (e.g., as described herein) or other (e.g., other agents for treating cardiotoxicity) treatments. When administered with one or more anti-cancer treatments, the NPs and the anti-cancer treatments are separate molecular entities. Accordingly, the NPs are not delivery vehicles for the anti-cancer therapies.

[0070] In some examples, the NPs are administered by intravenous, intra-arterial, oral, or intra-cardiac routes. The NPs can be administered, e.g., in dosages in the range of 100-2000, 200-1800, 300-1500, 400-1200, 500-1000, 600-800, or 700 mg. Treatment can be carried out one time or repeated, as determined to be appropriate by those of skill in the art. Thus, for example, treatment can be carried out twice daily, daily, semi-weekly, weekly, bi-weekly, monthly, bi-monthly, etc. The NPs can be formulated for administration based on the administration route chosen. For example, the NPs can be formulated in water or in an optionally buffered saline solution (e.g., phosphate-buffered saline) or in a capsule.

[0071] Subjects that can be treated according to the methods of the invention include those having or at risk of developing cardiotoxicity, which is the result of, e.g., exposure to one or more drugs (e.g., chemotherapy or other anti-cancer therapies, anti-HIV therapies, or other therapies causing cardiotoxicity (e.g., anti-malarial therapy, such as chloroquine or hydroxychloroquine; antifungal therapy, such as amphotericin B, or anti-Parkinson therapy, such as bromocriptine)), treatments (e.g., radiation or surgery), or injuries (e.g., ischemic injury to the heart, such as ischemia-reperfusion injury, or other traumatic injury to the heart). The subjects treated according to the methods of the invention can be human patients, including adult patients and pediatric patients.

[0072] Cardiotoxicity results in damage to the heart tissue and can be characterized or result in a wide variety of cardiovascular conditions, which herein may be considered as a symptom of cardiotoxicity. For example, subjects having or at risk of cardiotoxicity according to the invention can be characterized by having or being at risk of developing one or more of heart failure (e.g., congestive heart failure), cardiomyopathy (e.g., dilated, hypertrophic, or restrictive cardiomyopathy), arrhythmias (e.g., QT interval prolongation or atrial fibrillation), conduction abnormalities, hypertension, myocardial ischemia, thromboembolism, coronary artery disease, pulmonary edema, left ventricular dysfunction, myocarditis, cardiogenic shock, pericarditis, pericardial effusion, valvular (e.g., mitral or aortic) stenosis and / or regurgitation, ventricular tachycardia, sinus bradycardia, atrioventricular block, arteritis, and ischemia. These conditions can be diagnosed or monitored using standard methods in the art including, e.g., radionuclide ventriculography, positron emission tomography (PET), cardiac magnetic resonance (CMR), echocardiography, or biomarker (e.g., troponin, cardiac natriuretic peptides, or myeloperoxidase) detection.

[0073] Cardiotoxicity may be subacute or acute, occurring during or soon after treatment, or may be chronic and occur either within 1 year of treatment (type 1 - early onset) or more than 1 year after treatment (type 2 - late onset). Although clinical definitions of cardiotoxicity are present in the art, e.g., that of the cardiac review and evaluation committee supervising trastuzumab clinical trials (see, e.g., Albini et al., J. Natl. Cancer Inst. 102(1 ):14-25, 2010), and can be consulted in the identification of cardiotoxicity, such definitions are not to be considered as limiting on the present invention. Rather, cardiotoxicity can be identified by those of skill in the art based on factors including, e.g., the treatments being used, as well as a subject’s condition before, during, and after treatment.

[0074] Treatments that can cause cardiotoxicity include, e.g., cancer therapies (e.g., chemotherapy, radiation therapy, immunotherapy, targeted therapies, and hormone therapies), HIV therapies, and other drug treatments (e.g., anti-malarial therapy, such as chloroquine or hydroxychloroquine; antifungal therapy, such as amphotericin B, or anti-Parkinson therapy, such as bromocriptine).

[0075] Specific examples of anti-cancer agents include anthracyclines (e.g., doxorubicin, mitoxatrone, pixantrone, epirubicin, idarubicin, and daunorubicin), HER2-targeted agents (e.g., trastuzumab, lapatinib, pertuzamab, and ado-trastuzumab emtasine), tyrosine kinase inhibitors (e.g., sunitinib, sorafenib, axitinib, imatinib, and osimertinib), angiogenesis inhibitors (e.g., bevacizumab, thalidomide, and cannabinoids), platinum-based chemotherapy agents (e.g., cisplatin, oxaliplatin, and carboplatin), microtubule inhibitors (e.g., taxanes, such as paclitaxel and docetaxel), antimetabolites (e.g., 5-fluorouricil, capecitabine, cytarabine, gemcitabine, methotrexate, and hydroxyurea), alkylating agents (e.g., cyclophosphamide), proteasome inhibitors (e.g., bortezomib and carfilzomib), and triterpenoids (e.g., lupeol). In some examples, the anti-cancer agent is an immuno-oncology agent, e.g., a chimeric antigen receptor (CAR) T cell therapy (e.g., tisagenlecleucel, KYMRIA™; or axicabtagene ciloleucel, YESCARTA™), adoptive cell transfer therapy, or a monoclonal antibody (e.g., an antibody against VEGF (e.g., bevacizumab or Avastin®), HER2 (e.g., trastuzumab or Herceptin®), CTLA-4 (e.g., ipilimumab), PD1 (e.g., pembrolizumab, Keytruda®; and nivolumab, Opdivo®), or PD-L1 ). Subject that will in the future, are currently, or have been treated with any one or more of these therapies are examples of subjects that can be treated according to the methods of the invention.

[0076] Furthermore, subjects treated according to the methods of the invention can optionally be diagnosed with cancer, in treatment for cancer, or in post-therapy recovery from cancer. The cancer treated according to the methods of the invention can optionally be a primary tumor, locally advanced, or metastatic.

[0077] In some examples, the cancer is selected from the group consisting of breast cancer, lung cancer (e.g., non-small cell lung cancer), stomach cancer, colon cancer, liver cancer, colorectal cancer, gallbladder cancer, pancreatic cancer, biliary tract cancer, rectal cancer, renal cancer, bladder cancer, urinary tract cancer, cervical cancer, endometrial cancer, ovarian cancer, vaginal cancer, vulvar cancer, prostate cancer, penile cancer, testicular cancer, pelvic cancer, brain cancer (e.g., glioma, glioblastoma, or astrocytoma), head and neck cancer, esophageal cancer, bronchus cancer, oral cancer, oropharyngeal cancer, thyroid cancer, larynx cancer, skin cancer (e.g., melanoma), central nervous system cancer, respiratory system cancer, bone cancer, and neuroendocrine cancer.

[0078] In various examples, the cancer is selected from the group consisting of leukemias (e.g., B-cell leukemia, T-cell leukemia, acute myeloid leukemia (AML), chronic myeloid leukemia (CML), acute lymphocytic (lymphoblastic) leukemia (ALL), chronic lymphocytic leukemia (CLL), and erythroleukemia), lymphomas (e.g., Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, Burkitt lymphoma, and follicular lymphoma), and sarcomas (e.g., angiosarcoma, hemangiosarcoma, chondrosarcoma, Ewing’s sarcoma, fibrosarcoma, gastrointestinal stromal tumor, leiomyosarcoma, liposarcoma, malignant peripheral nerve sheath tumor, malignant fibrous cytoma, osteosarcoma, pleomorphic sarcoma, rhabdomyosarcoma, synovial sarcoma, vascular sarcoma, Kaposi’s sarcoma, dermatofibrosarcoma, epithelioid sarcoma, leiomyosarcoma, and neurofibrosarcoma).

[0079] Additional drugs that may cause cardiotoxicity include, e.g., anti-malarials (e.g., chloroquine and hydroxychloroquine), antifungals (e.g., amphotericin B), and anti-Parkinson agents (e.g., bromocriptine. Accordingly, the therapeutic methods of the invention can be used in conjunction with treatment with these agents, as well.

[0080] Imaging

[0081] The NPs of the invention can be used in imaging methods. In some examples, the NPs are tagged with a label, such as a fluorescent label (e.g., Cyanine5.5), using, e.g., click chemistry. In some examples, the fluorescent label is linked to the NP via a peptide (e.g., a poly-arginine peptide, e.g., see above and elsewhere herein). In some examples, the imaging methods are carried out in pre-clinical models (e.g., murine models). This can be done, for example, to demonstrate and quantify the amount of PLGA uptake in a particular tissue or organ, such as the heart.

[0082] Kits

[0083] The invention provides kits that can be used in the methods of the invention. The kits include NPs as described herein (e.g., PLGA NPs), optionally in combination with one or more drug for treatment of a disease (e.g., cancer) in a subject. Thus, the kits can optionally include NPs (e.g., PLGA NPs) and one or more anti-cancer agents (e.g., chemotherapeutic or immune-oncology agents; also see above; anti-HIV therapy; anti-malarial therapy, such as chloroquine or hydroxychloroquine; antifungal therapy, such as amphotericin B, or anti-Parkinson therapy, such as bromocriptine). The kits can optionally further include devices for administering the NPs and / or the other drug(s), or instructions for administration. In other examples, the kits include labeled NPs. These kits can be used in imaging methods, e.g., as described herein.

[0084] Examples

[0085] Example 1

[0086] Chemotherapy-induced cardiotoxicity remains prevalent and deadly, with no effective therapy to slow the progression to irreversible heart failure which, in the case of doxorubicin (Dox) can reach 50% mortality. Dox impact on cardiomyocytes (CMs) is multifocal, including oxidative stress, lysosome alkalin ization, and apoptosis. PLGAs are FDA-approved polymers and form defined nanoparticles (NPs). We have shown that PLGA NPs target the lysosomal compartments, restore lysosomal acidity after Dox, and confer cardioprotective effects.

[0087] We synthesized fluorescent PLGA NPs by click chemistry. In H9C2 myocytes exposed to 1 -5 pM of Dox + / - 1 mg / ml of PLGA, we measured cell viability (MTT), lysosomal pH (OG-514), mitochondrial membrane potential (JC-1 ), and autophagy proteins (western blot). We further co-injected C57BI6 mice with PLGA (10 mg / kg, i.v.) and Dox (15 mg / kg, i.p.), to image apoptosis (Annexin) and autophagy (cathepsin-activatable autophagy probe, ADN, unpublished) after 24 hours, or 4 mg / kg Dox weekly, 5x, i.p. and echo after 3-4 weeks.

[0088] As explained in more detail below, PLGA NPs formulated are of controlled size and valency and emit near-infrared fluorescence. In H9C2s, PLGA significantly improved survival after Dox, acidified lysosomes, did not impact cell energetics, and further restored autophagic flux. Imaging in Dox mice revealed significant apoptosis reduction and autophagy activation, and cardiac function recovery.

[0089] Synthesis and characterization of functionalized PLGA NPs

[0090] Figure 1 A provides schematics of procedures used to synthesize PLGA NPs. FDA-approved PLGA was dissolved in tetrahydrofuran (THF), functionalized with Cy5.5-fluorescent poly-arginine peptide (Boston Open Labs, Cambridge, MA) by copper-free click chemistry, and stirred in water for 1 hour at room temperature before purifying with a 50 kDa filter. The resulting PLGA NPs are spherical, with PLGA coating encapsulating fluorescent peptides. Transmission electron microscopy (TEM) characterization of the PLGA NPs reveals spherical PLGA NPs without (top) or with (bottom) peptide functionalization (Figure 1 B). Absorbance spectra of PLGA NPs with tunable functionalization are shown in Figure 1 C. Table 1 provides information regarding physical characterization of formulations without (PLGA NP) or with (pPLGA NP) functionalization. Zeta potential of surface charge, diameter, and poly disperse index were measured by dynamic light scattering (DLS).

[0091] Table 1 : Characterization of PLGA formulations

[0092] We have found that, when functionalized covalently, particle size is smaller and more consistent.

[0093] The average size of 89 nm is significantly smaller than the particle size formed by simple loading (103 nm) or without loading (133 nm) and improves the particle size variations.

[0094] PLGA uptake and cytoprotective effects in cardiomyocyte H9C2 cells in vitro

[0095] Representative FACS scatter plots show that almost all cells take up pPLGA after 4-hour incubation (Figure 2A). Confocal microscopy confirmed the localization of pPLGA in lysosomal compartments, showing that it co-localizes well with commercial lysosome stain lysotracker (LTR). Scale bar=10pm (Figure 2B). While PLGA taken up by normal cells does not alter physiological pH, when lysosomal pH is alkalinated by doxorubicin (Dox), PLGA restores pH to acidic levels (Figure 2C). Dox (5 pM, 24 hours) significantly impairs H9C2 cell survival, while co-treatment with PLGA NPs significantly improves survival (Figure 2D). PLGA NPs functionalized with fluorescent peptide do not impair the cytoprotective effects seen in Figure 2D. In fact, it significantly improves survival as compared to PLGA without functionalization (Figure 2E). The cytoprotective effects of PLGA NPs are seen in all PLGAs tested, with different numbers of functional groups (Figures 2F). *p<0.05, **p<0.01 ,****p<0.0001 (Figure 2A: t-test, Figures 2C-2F: ANOVA). Mitochondrial membrane potential (Al4Jm) was significantly reduced by Dox, but no change was seen with PLGA (n=3) (Figure 2G). Western blot showed Dox-induced autophagy impairment evident by elevated LC3 II and reduced Beclin-1 . PLGA treatment reduced LC3 II accumulation and upregulated Beclin-1 levels (n=3) (Figure 2H).

[0096] PLGA uptake in mouse hearts in vivo

[0097] Peptide-functionalized Cy5.5-fluorescent pPLGA NPs were injected intravenously in naive mice at 10 mg / kg and allowed to circulate for 4 hours (Figure 3A). A representative mid-left ventricular slice of vehicle injected control mouse heart compared to pPLGA injected mice is shown in Figure 3B. The fluorescence intensity map of pPLGA in the myocardium was false-colored based on the scale shown in the heatmap. The fluorescence intensity of the target tissue was quantified by positioning a region-of- interest over the myocardium, while the background pPLGA fluorescence intensity was measured in the serum. Quantification of PLGA uptake was then calculated as contrast to noise ratio (CNR): [(pPLGA signal intensity in the myocardium)-(pPLGA signal intensity in the serum)] / Standard deviation of air signal. There was a significant increase in pPLGA CNR in mice injected with the fluorescent NP, compared to vehicle injected mice. ****p<0.0001 , ANOVA (Figure 3C). PLGA treatment restores cardiac function in doxorubicin challenged mice

[0098] Representative M-mode images of mice exposed to chronic doxorubicin challenge (4 mg / kg i.p. weekly, 5 doses) with or without PLGA co-treatment, given at early doxorubicin injection are shown in Figure 4A. PLGA significantly improved ejection fraction and fractional shortening, as shown in Figures 4B and 4C. Strain analysis reveals that PLGA significantly improves both regional and global longitudinal strain, restoring it to the baseline levels. *p<0.05, **p<0.01 . (Figures 4D and 4E) (Figures 4B-4D: t-test, Figure 4E: ANOVA). When functionalized covalently, the particle size is smaller and more consistent (see figure below). The average size of 89 nm is significantly smaller than the particle size formed by simple loading (103 nm) or without loading (133 nm), and improves the particle size variations.

[0099] Example 2

[0100] In additional studies, fluorescent poly-arginine peptide functionalized PLGA was synthesized using the method illustrated in Fig. 5. Azido-PLGA (8 arm) dissolved in dimethyl sulfoxide (DMSO) was reacted with fluorescent DBCO-Arg4-Cy5.5 peptide (synthesized by Boston Open Labs, Cambridge MA) under vigorous stirring at room temperature. After 1 hour of continuous stirring, the reaction was added to water under vigorous stirring at room temperature. After 1 hour of stirring, the resultant nanoparticle was purified with an Amicon filter (MilliporeSigma, Burlington MA) with a 50 kDa size cutoff. The retentate was washed 3x with water, collected, and lyophilized. The powder was then stored at -80eC and resuspended in dPBS (Dulbecco’s phosphate buffered saline) for cell and mouse experiments.

[0101] The fluorescent poly-arginine peptide functionalized PLGA nanoparticles were characterized for payload level. The number of fluorescent DBCO-Arg4-Cy5.5 peptides per PLGA was determined by absorbance spectroscopy by measuring the OD (optical density) PLGA peak at 275 nm (Figure 6A) and Cy5.5 at 688 nm (Figure 6B). The standard curves show an R squared value of 0.99, allowing the payload of fluorescent peptide functionalized on PLGA nanoparticles to be precisely and quantitatively characterized.

[0102] In further experiments, it was found that PLGA functionalized with Arg4-Cy5.5 peptide enhanced cardiac cell survival after doxorubicin in H9C2 cells treated with cytotoxic doxorubicin (Figure 7). PLGA functionalized with 1 or 4 Arg4 peptide(s) per PLGA (8 arm) both significantly improved cell survival compared to PLGA functionalized with the Cy5.5 fluorochrome without the peptide as control. Survival was measured by MTT assay at 24 hours after doxorubicin. Vehicle=DMSO. *p<0.05, ****p<0.0001 , ANOVA,

[0103] In additional experiments, it was found that PLGA functionalized with Arg4-Cy5.5 peptide reduced cardiac apoptosis in doxorubicin-injected mice in vivo (Figure 8). We injected 16 C57BI6 wild type mice with doxorubicin (15 mg / kg, i.p.) to induce apoptosis. Five of the doxorubicin-injected mice received 10 mg / kg PLGA only, 5 received 10 mg / kg PLGA functionalized with Arg4-Cy5.5 peptide, and 6 received doxorubicin only (Figure 8A). Six additional control C57BI6 mice were injected with vehicle (PBS). Fluorescent annexin V (Anx V) was injected to label apoptotic cells (Figure 8A). Representative in vivo Annexin imaging reveals that PLGA robustly reduced Anx V signal in the thorax (H: heart), while no change in thyroid (T) or liver (L) uptake, a major route of Anx probe clearance (Figure 8B). Mid-left ventricular cardiac slice of Anx V signal is shown in Figure 8C. Both plain PLGA and 4-arginine-Cy5.5 peptide functionalized PLGA significantly reduced apoptosis at 24-hours after doxorubicin injection (Figure 8D). The 4-arginine-Cy5.5. peptide functionalized PLGA formulation further significantly reduced apoptosis compared to plain PLGA (Figure 8D). *p<0.05, **p<0.01 , ***p<0.001 , ****p<0.0001 , ANOVA. We also found a significant 32.7% increase in ADN signal / autophagy, n=7 Dox only mice, n=4 Dox+PLGA mice (Figure 8E). **p<0.01 , t-test.

[0104] OTHER EMBODIMENTS

[0105] Various modifications and variations of the described invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in the art are intended to be within the scope of the invention.

[0106] Some embodiments are within the scope of the following numbered paragraphs.

[0107] 1 . A method of preventing, treating, or reducing cardiotoxicity in a subject resulting from treatment with a therapy causing cardiotoxicity, the method comprising administering acidifying nanoparticles (NPs) to the subject, wherein the NPs are derivatized with peptides.

[0108] 2. The method of paragraph 1 , wherein the nanoparticles are poly(lactic-co-glycolic acid) (PLGA), poly(lactic acid) (PLA), poly(glutamic acid) (PLG), polycaprolactone (PCL), or polyester nanoparticles.

[0109] 3. The method of paragraph 1 or 2, wherein the nanoparticles are PLGA nanoparticles, wherein optionally the PLGA is present in pure D-form, pure L-form, or a mixture of D- and L-forms.

[0110] 4. The method of paragraph 3, wherein the PLGA nanoparticles have lactic acid to glycolic acid ratios of, e.g., 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, or 85:15.

[0111] 5. The method of any one of paragraphs 1 to 4, wherein the nanoparticles have at least one dimension (e.g., a diameter) within the range of 1 -1000 nm (e.g., 50-900, 100-750, 150-600, or 200-500), including any integer value between 1 nm and 1000 nm (including about 1 , 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 500, 600, 700, 800, 900, and 1000, or ranges between any of these values, or have at least one dimension (e.g., a diameter) that is no more than 1 pm.

[0112] 6. The method of any one of paragraphs 3 to 5, wherein the PLGA nanoparticles comprise multiarm PLGA molecules.

[0113] 7. The method of paragraph 6, wherein the multi-arm PLGA molecules comprise 4, 6, or 8 arms.

[0114] 8. The method of paragraph 6 or 7, wherein the molar ratio of PLGA to peptide is less than 1 :x, wherein x is the number of arms.

[0115] 9. The method of paragraph 8, wherein the multi-arm PLGA comprises 8 arms and the molar ratio of PLGA to peptide is less than 1 :8 (e.g., 1 :1 , 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, or 1 :7).

[0116] 10. The method of any one of paragraphs 1 to 9, wherein the peptides are positively charged under physiological conditions.

[0117] 11 . The method of any one of paragraphs 1 to 10, wherein the peptides comprise 2 to 50 amino acids, 2 to 30 amino acids, 2 to 20 amino acids, 2 to 10 amino acids, 2 to 5 amino acids, 3 amino acids, or 4 amino acids. 12. The method of any one of paragraphs 1 to 11 , wherein the peptides are arginine-containing (e.g., arginine-rich) peptides that are positively charged under physiological pH and further optionally wherein the peptides are capable of traversing the plasma membrane of eukaryotic cells.

[0118] 13. The method of any one of paragraphs 1 to 12, wherein the peptides are Arg4 peptides.

[0119] 14. The method of any one of paragraphs 1 to 13, wherein the peptides are covalently linked to the nanoparticles.

[0120] 15. The method of any one of paragraphs 1 to 14, wherein the peptides are covalently linked to the nanoparticles by click chemistry, wherein optionally the linkage comprises dibenzocyclooctyne (DBCO), and / or wherein optionally the linkage comprises polyethylene glycol (PEG) (e.g., 1 k or 5k) between the DBCO and a PLGA arm.

[0121] 16. The method of any one of paragraphs 1 to 15, wherein the nanoparticles comprise a detectable label.

[0122] 17. The method of paragraph 16, wherein the detectable label is attached to the nanoparticle via the peptide, e.g., at the N-terminal end of the peptide or at the C-terminal end of the peptide.

[0123] 18. The method of paragraph 16 or 17, wherein the detectable label is fluorescent.

[0124] 19. The method of any one of paragraphs 1 to 18, wherein the nanoparticles comprise polyethylene glycol.

[0125] 20. The method of any one of paragraphs 1 to 19, wherein the subject does not have, but is at risk of developing, cardiotoxicity.

[0126] 21 . The method of any one of paragraphs 1 to 20, wherein the subject has one or more symptoms of cardiotoxicity.

[0127] 22. The method of any one of paragraphs 1 to 21 wherein the acidifying nanoparticles do not comprise or are not covalently linked to a therapeutic agent, such as an anti-cancer agent, wherein optionally the therapeutic agent causes cardiotoxicity.

[0128] 23. The method of any one of paragraphs 1 to 22, wherein the therapy causing cardiotoxicity is an anti-cancer therapy.

[0129] 24. The method of any one of paragraphs 1 to 23, wherein the subject has been, is currently, or will be under treatment with an anticancer therapy selected from the group consisting of chemotherapy, radiation therapy, immunotherapy, targeted therapy, and hormone therapy.

[0130] 25. The method of paragraph 24, wherein the therapy comprises treatment with an anticancer agent selected from one or more of the group consisting of anthracyclines, HER2-targeted agents, tyrosine kinase inhibitors, angiogenesis inhibitors, platinum-based chemotherapy agents, microtubule inhibitors, antimetabolites, alkylating agents, proteasome inhibitors, and lupeol.

[0131] 26. The method of paragraph 25, wherein:

[0132] (a) the anthracycline is selected from the group consisting of doxorubicin, mitoxatrone, epirubicin, idarubicin, and daunorubicin;

[0133] (b) the HER2-targeted agent is selected from the group consisting of trastuzumab, lapatinib, pertuzamab, and ado-trastuzumab emtasine;

[0134] (c) the tyrosine kinase inhibitor is selected from the group consisting of sunitinib, sorafenib, axitinib, imatinib, and osimertinib; (d) the angiogenesis inhibitor is selected from the group consisting of bevacizumab, thalidomide, and cannabinoids;

[0135] (e) the platinum-based chemotherapy agent is selected from the group consisting of cisplatin, oxaliplatin, and carboplatin;

[0136] (f) the microtubule inhibitor is selected from taxanes, such as paclitaxel and docetaxel;

[0137] (g) the antimetabolite is selected from the group consisting of 5-fluorouricil, capecitabine, cytarabine, gemcitabine, methotrexate, and hydroxyurea;

[0138] (h) the alkylating agent is cyclophosphamide; or

[0139] (i) the proteasome inhibitor is selected from the group consisting of bortezomib and carfilzomib.

[0140] 27. The method of paragraph 24, wherein the anticancer therapy is an immunotherapy selected from the group consisting of a chimeric antigen receptor (CAR) T cell therapy, adoptive cell transfer therapy, or a monoclonal antibody.

[0141] 28. The method of paragraph 27, wherein:

[0142] (a) the chimeric antigen receptor (CAR) T cell therapy is selected from the group consisting of tisagenlecleucel and axicabtagene ciloleucel; or

[0143] (b) the monoclonal antibody is selected from the group consisting of a monoclonal antibody targeted against VEGF, HER2, CTLA-4, PD1 and PD-L1 .

[0144] 29. The method of any one of paragraphs 1 to 28, wherein the subject has or is at risk of developing one or more of: heart failure (e.g., congestive heart failure), cardiomyopathy (e.g., dilated, hypertrophic, or restrictive cardiomyopathy), arrhythmias (e.g., QT interval prolongation or atrial fibrillation), conduction abnormalities, hypertension, myocardial ischemia, thromboembolism, coronary artery disease, pulmonary edema, left ventricular dysfunction, myocarditis, cardiogenic shock, pericarditis, pericardial effusion, valvular (e.g., mitral or aoritic) stenosis and / or regurgitation, ventricular tachycardia, sinus bradycardia, atrioventricular block, arteritis, and ischemia. These conditions can be diagnosed or monitored using standard methods in the art including, e.g., radionuclide ventriculography, positron emission tomography (PET), cardiac magnetic resonance (CMR), echocardiography, or biomarker (e.g., troponin, cardiac natriuretic peptides, or myeloperoxidase) detection.

[0145] 30. The method of any one of paragraphs 1 to 29, wherein the therapy causing cardiotoxicity is an anti-HIV therapy; anti-malarial therapy, such as chloroquine or hydroxychloroquine; antifungal therapy, such as amphotericin B, or anti-Parkinson therapy, such as bromocriptine.

[0146] 31 . A kit comprising acidifying nanoparticles (NPs) and a drug that causes cardiotoxicity, wherein the NPs are derivatized with peptides.

[0147] 32. The kit of paragraph 31 , wherein the drug that causes cardiotoxicity is an anti-cancer drug.

[0148] 33. The kit of paragraph 31 or 32, wherein the acidifying nanoparticle comprises PLGA NPs.

[0149] 34. The kit of paragraph 32 or 33, wherein the anti-cancer agent is selected from one or more of the group consisting of anthracyclines, HER2-targeted agents, tyrosine kinase inhibitors, angiogenesis inhibitors, platinum-based chemotherapy agents, microtubule inhibitors, antimetabolites, alkylating agents, proteasome inhibitors, and lupeol.

[0150] 35. The kit of paragraph 34, wherein:

[0151] (a) the anthracycline is selected from the group consisting of doxorubicin, mitoxatrone, epirubicin, idarubicin, and daunorubicin; (b) the HER2-targeted agent is selected from the group consisting of trastuzumab, lapatinib, pertuzamab, and ado-trastuzumab emtasine;

[0152] (c) the tyrosine kinase inhibitor is selected from the group consisting of sunitinib, sorafenib, axitinib, imatinib, and osimertinib;

[0153] (d) the angiogenesis inhibitor is selected from the group consisting of bevacizumab, thalidomide, and cannabinoids;

[0154] (e) the platinum-based chemotherapy agent is selected from the group consisting of cisplatin, oxaliplatin, and carboplatin;

[0155] (f) the microtubule inhibitor is selected from taxanes, such as paclitaxel and docetaxel;

[0156] (g) the antimetabolite is selected from the group consisting of 5-fluorouricil, capecitabine, cytarabine, gemcitabine, methotrexate, and hydroxyurea;

[0157] (h) the alkylating agent is cyclophosphamide; or

[0158] (i) the proteasome inhibitor is selected from the group consisting of bortezomib and carfilzomib.

[0159] 36. The kit of paragraph 34, wherein the anticancer agent is an immunotherapy selected from the group consisting of a chimeric antigen receptor (CAR) T cell therapy, adoptive cell transfer therapy, or a monoclonal antibody.

[0160] 37. The kit of paragraph 36, wherein:

[0161] (a) the chimeric antigen receptor (CAR) T cell therapy is selected from the group consisting of tisagenlecleucel and axicabtagene ciloleucel; or

[0162] (b) the monoclonal antibody is selected from the group consisting of a monoclonal antibody targeted against VEGF, HER2, CTLA-4, PD1 and PD-L1 .

[0163] 38. The kit of any one of paragraphs 31 to 37, wherein the acidifying nanoparticles do not comprise or are not covalently linked to an anti-cancer agent or any therapeutic associated with cardiotoxicity.

[0164] 39. A PLGA nanoparticle derivatized with peptides.

[0165] 40. The nanoparticle of paragraph 39, wherein the nanoparticle further comprises labels (e.g., fluorescent labels) that are linked to the nanoparticle by the peptides.

[0166] 41 . The nanoparticle of paragraph 39 or 40, wherein the labeled peptides are linked to the nanoparticle using click chemistry, e.g., optionally wherein the linkage comprises DBCO and / or PEG (e.g., 1 k or 5k).

[0167] 42. The nanoparticle of paragraph 40 or 41 , wherein the labels comprise a fluorophore linked to the PLGA nanoparticle through an -(Arg4)- peptide.

[0168] 43. The nanoparticle of paragraph 42, wherein the fluorophore is Cyanine5.5.

[0169] 44. A method for medical imaging, the method comprising administering a nanoparticle of any one of paragraphs 39 to 43 to a subject, and detecting the presence of the nanoparticle in a tissue or organ of the subject.

[0170] The disclosure also includes uses of the compositions (e.g., nanoparticles) described herein for the purposes described herein, and use of these compositions for the preparation of medicaments for the purposes. Other embodiments are within the scope of the claims.

[0171] What is claimed is:

Claims

CLAIMS1 . A method of preventing, treating, or reducing cardiotoxicity in a subject resulting from treatment with a therapy causing cardiotoxicity, the method comprising administering acidifying nanoparticles (NPs) to the subject, wherein the NPs are derivatized with peptides.

2. The method of claim 1 , wherein the nanoparticles are poly(lactic-co-glycolic acid) (PLGA), poly(lactic acid) (PLA), poly(glutamic acid) (PLG), polycaprolactone (PCL), or polyester nanoparticles.

3. The method of claim 1 , wherein the nanoparticles are PLGA nanoparticles, wherein optionally the PLGA is present in pure D-form, pure L-form, or a mixture of D- and L-forms.

4. The method of claim 3, wherein the PLGA nanoparticles have lactic acid to glycolic acid ratios of, e.g., 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, or 85:15.

5. The method of claim 1 , wherein the nanoparticles have at least one dimension (e.g., a diameter) within the range of 1 -1000 nm (e.g., 50-900, 100-750, 150-600, or 200-500), including any integer value between 1 nm and 1000 nm (including about 1 , 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 500, 600, 700, 800, 900, and 1000, or ranges between any of these values, or have at least one dimension (e.g., a diameter) that is no more than 1 pm.

6. The method of claim 3, wherein the PLGA nanoparticles comprise multi-arm PLGA molecules.

7. The method of claim 6, wherein the multi-arm PLGA molecules comprise 4, 6, or 8 arms.

8. The method of claim 6, wherein the molar ratio of PLGA to peptide is less than 1 :x, wherein x is the number of arms.

9. The method of claim 8, wherein the multi-arm PLGA comprises 8 arms and the molar ratio of PLGA to peptide is less than 1 :8 (e.g., 1 :1 , 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, or 1 :7).

10. The method of claim 1 , wherein the peptides are positively charged under physiological conditions.11 . The method of claim 1 , wherein the peptides comprise 2 to 50 amino acids, 2 to 30 amino acids, 2 to 20 amino acids, 2 to 10 amino acids, 2 to 5 amino acids, 3 amino acids, or 4 amino acids.

12. The method of claim 1 , wherein the peptides are arginine-containing (e.g., arginine-rich) peptides that are positively charged under physiological pH and further optionally wherein the peptides are capable of traversing the plasma membrane of eukaryotic cells.

13. The method of claim 1 , wherein the peptides are Arg4 peptides.

14. The method of claim 1 , wherein the peptides are covalently linked to the nanoparticles.

15. The method of claim 1 , wherein the peptides are covalently linked to the nanoparticles by click chemistry, wherein optionally the linkage comprises dibenzocyclooctyne (DBCO), and / or wherein optionally the linkage comprises polyethylene glycol (PEG) (e.g., 1 k or 5k) between the DBCO and a PLGA arm.

16. The method of claim 1 , wherein the nanoparticles comprise a detectable label.

17. The method of claim 16, wherein the detectable label is attached to the nanoparticle via the peptide, e.g., at the N-terminal end of the peptide or at the C-terminal end of the peptide.

18. The method of claim 16, wherein the detectable label is fluorescent.

19. The method of claim 1 , wherein the nanoparticles comprise polyethylene glycol.

20. The method of claim 1 , wherein the subject does not have, but is at risk of developing, cardiotoxicity.21 . The method of claim 1 , wherein the subject has one or more symptoms of cardiotoxicity.

22. The method of claim 1 , wherein the acidifying nanoparticles do not comprise or are not covalently linked to a therapeutic agent, such as an anti-cancer agent, wherein optionally the therapeutic agent causes cardiotoxicity.

23. The method of claim 1 , wherein the therapy causing cardiotoxicity is an anti-cancer therapy.

24. The method of claim 1 , wherein the subject has been, is currently, or will be under treatment with an anticancer therapy selected from the group consisting of chemotherapy, radiation therapy, immunotherapy, targeted therapy, and hormone therapy.

25. The method of claim 24, wherein the therapy comprises treatment with an anticancer agent selected from one or more of the group consisting of anthracyclines, HER2-targeted agents, tyrosine kinase inhibitors, angiogenesis inhibitors, platinum-based chemotherapy agents, microtubule inhibitors, antimetabolites, alkylating agents, proteasome inhibitors, and lupeol.

26. The method of claim 25, wherein:(a) the anthracycline is selected from the group consisting of doxorubicin, mitoxatrone, epirubicin, idarubicin, and daunorubicin;(b) the HER2-targeted agent is selected from the group consisting of trastuzumab, lapatinib, pertuzamab, and ado-trastuzumab emtasine;(c) the tyrosine kinase inhibitor is selected from the group consisting of sunitinib, sorafenib, axitinib, imatinib, and osimertinib;(d) the angiogenesis inhibitor is selected from the group consisting of bevacizumab, thalidomide, and cannabinoids;(e) the platinum-based chemotherapy agent is selected from the group consisting of cisplatin, oxaliplatin, and carboplatin;(f) the microtubule inhibitor is selected from taxanes, such as paclitaxel and docetaxel;(g) the antimetabolite is selected from the group consisting of 5-fluorouricil, capecitabine, cytarabine, gemcitabine, methotrexate, and hydroxyurea;(h) the alkylating agent is cyclophosphamide; or(i) the proteasome inhibitor is selected from the group consisting of bortezomib and carfilzomib.

27. The method of claim 24, wherein the anticancer therapy is an immunotherapy selected from the group consisting of a chimeric antigen receptor (CAR) T cell therapy, adoptive cell transfer therapy, or a monoclonal antibody.

28. The method of claim 27, wherein:(a) the chimeric antigen receptor (CAR) T cell therapy is selected from the group consisting of tisagenlecleucel and axicabtagene ciloleucel; or(b) the monoclonal antibody is selected from the group consisting of a monoclonal antibody targeted against VEGF, HER2, CTLA-4, PD1 and PD-L1 .

29. The method of claim 1 , wherein the subject has or is at risk of developing one or more of: heart failure (e.g., congestive heart failure), cardiomyopathy (e.g., dilated, hypertrophic, or restrictive cardiomyopathy), arrhythmias (e.g., QT interval prolongation or atrial fibrillation), conduction abnormalities, hypertension, myocardial ischemia, thromboembolism, coronary artery disease, pulmonary edema, left ventricular dysfunction, myocarditis, cardiogenic shock, pericarditis, pericardial effusion, valvular (e.g., mitral or aoritic) stenosis and / or regurgitation, ventricular tachycardia, sinus bradycardia, atrioventricular block, arteritis, and ischemia. These conditions can be diagnosed or monitored using standard methods in the art including, e.g., radionuclide ventriculography, positron emission tomography (PET), cardiac magnetic resonance (CMR), echocardiography, or biomarker (e.g., troponin, cardiac natriuretic peptides, or myeloperoxidase) detection.

30. The method of claim 1 , wherein the therapy causing cardiotoxicity is an anti-HIV therapy; anti-malarial therapy, such as chloroquine or hydroxychloroquine; antifungal therapy, such as amphotericin B, or anti-Parkinson therapy, such as bromocriptine.31 . A kit comprising acidifying nanoparticles (NPs) and a drug that causes cardiotoxicity, wherein the NPs are derivatized with peptides.

32. The kit of claim 31 , wherein the drug that causes cardiotoxicity is an anti-cancer drug.

33. The kit of claim 31 , wherein the acidifying nanoparticle comprises PLGA NPs.

34. The kit of claim 32, wherein the anti-cancer agent is selected from one or more of the group consisting of anthracyclines, HER2-targeted agents, tyrosine kinase inhibitors, angiogenesis inhibitors, platinum-based chemotherapy agents, microtubule inhibitors, antimetabolites, alkylating agents, proteasome inhibitors, and lupeol.

35. The kit of claim 34, wherein:(a) the anthracycline is selected from the group consisting of doxorubicin, mitoxatrone, epirubicin, idarubicin, and daunorubicin;(b) the HER2-targeted agent is selected from the group consisting of trastuzumab, lapatinib, pertuzamab, and ado-trastuzumab emtasine;(c) the tyrosine kinase inhibitor is selected from the group consisting of sunitinib, sorafenib, axitinib, imatinib, and osimertinib;(d) the angiogenesis inhibitor is selected from the group consisting of bevacizumab, thalidomide, and cannabinoids;(e) the platinum-based chemotherapy agent is selected from the group consisting of cisplatin, oxaliplatin, and carboplatin;(f) the microtubule inhibitor is selected from taxanes, such as paclitaxel and docetaxel;(g) the antimetabolite is selected from the group consisting of 5-fluorouricil, capecitabine, cytarabine, gemcitabine, methotrexate, and hydroxyurea;(h) the alkylating agent is cyclophosphamide; or(i) the proteasome inhibitor is selected from the group consisting of bortezomib and carfilzomib.

36. The kit of claim 34, wherein the anticancer agent is an immunotherapy selected from the group consisting of a chimeric antigen receptor (CAR) T cell therapy, adoptive cell transfer therapy, or a monoclonal antibody.

37. The kit of claim 36, wherein:(a) the chimeric antigen receptor (CAR) T cell therapy is selected from the group consisting of tisagenlecleucel and axicabtagene ciloleucel; or(b) the monoclonal antibody is selected from the group consisting of a monoclonal antibody targeted against VEGF, HER2, CTLA-4, PD1 and PD-L1 .

38. The kit of claim 31 , wherein the acidifying nanoparticles do not comprise or are not covalently linked to an anti-cancer agent or any therapeutic associated with cardiotoxicity.

39. A PLGA nanoparticle derivatized with peptides.

40. The nanoparticle of claim 39, wherein the nanoparticle further comprises labels (e.g., fluorescent labels) that are linked to the nanoparticle by the peptides.41 . The nanoparticle of claim 39, wherein the labeled peptides are linked to the nanoparticle using click chemistry, e.g., optionally wherein the linkage comprises DBCO and / or PEG (e.g., 1 k or 5k).

42. The nanoparticle of claim 40, wherein the labels comprise a fluorophore linked to the PLGA nanoparticle through an -(Arg4)- peptide.

43. The nanoparticle of claim 42, wherein the fluorophore is Cyanine5.5.

44. A method for medical imaging, the method comprising administering a nanoparticle of claim 39 to a subject and detecting the presence of the nanoparticle in a tissue or organ of the subject.

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