Structural and Functional Impairments of Reconstituted High-Density Lipoprotein by Incorporation of Recombinant ß-Amyloid42.

Beta (ß)-amyloid (Aß) is a causative protein of Alzheimer's disease (AD). In the pathogenesis of AD, the apolipoprotein (apo) A-I and high-density lipoprotein (HDL) metabolism is essential for the clearance of Aß. In this study, recombinant Aß42 was expressed and purified via the pET-30a expression vector and E.coli production system to elucidate the physiological effects of Aß on HDL metabolism. The recombinant human Aß protein (51 aa) was purified to at least 95% purity and characterized in either the lipid-free and lipid-bound states with apoA-I. Aß was incorporated into the reconstituted HDL (rHDL) (molar ratio 95:5:1, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC):cholesterol:apoA-I) with various apoA-I:Aß ratios from 1:0 to 1:0.5, 1:1 and 1:2. With an increasing molar ratio of Aß, the α-helicity of apoA-I was decreased from 62% to 36% with a red shift of the Trp wavelength maximum fluorescence from 337 to 340 nm in apoA-I. The glycation reaction of apoA-I was accelerated further by the addition of Aß. The treatment of fructose and Aß caused more multimerization of apoA-I in the lipid-free state and in HDL. The phospholipid-binding ability of apoA-I was impaired severely by the addition of Aß in a dose-dependent manner. The phagocytosis of LDL into macrophages was accelerated more by the presence of Aß with the production of more oxidized species. Aß severely impaired tissue regeneration, and a microinjection of Aß enhanced embryotoxicity. In conclusion, the beneficial functions of apoA-I and HDL were severely impaired by the addition of Aß via its detrimental effect on secondary structure. The impairment of HDL functionality occurred more synergistically by means of the co-addition of fructose and Aß.

Co-administration of CSL112 (apolipoprotein A-I [human]) with atorvastatin and alirocumab is not associated with increased hepatotoxic or toxicokinetic effects in rats.

CSL112 (apolipoprotein A-I, apo AI [human]) is an investigational drug in Phase 3 development for risk reduction of early recurrent cardiovascular events following an acute myocardial infarction (AMI). Although CSL112 is known to be well tolerated with a regimen of four weekly 6 g intravenous infusions after AMI, high doses of reconstituted apo AI preparations can transiently elevate liver enzymes in rats, raising the possibility of additive liver toxicity and toxicokinetic (TK) effects upon co-administration with cholesterol-lowering drugs, i.e., HMG-CoA reductase and proprotein convertase subtilisin/kexin type 9 inhibitors. We performed a toxicity and TK study in CD rats assigned to eleven treatment groups, including two dose levels of intravenous (IV) CSL112 (140 mg/kg, low-dose; 600 mg/kg, high-dose) administered as a single dose, alone or with intravenous alirocumab 50 mg/kg/week and/or oral atorvastatin 10 mg/kg/day. In addition, control groups of atorvastatin and alirocumab alone and in combination were investigated. Results showed some liver enzyme elevations (remaining <2-fold of baseline) related to administration of CSL112 alone. There was limited evidence of an additive effect of CSL112 on liver enzymes when combined, at either dose level, with alirocumab and/or atorvastatin, and histology revealed no evidence of an increased incidence or severity of hepatocyte vacuolation compared to the control treatments. Co-administration of the study drugs had minimal effect on their respective exposure levels, and on levels of total cholesterol and high-density lipoprotein cholesterol. These data support concomitant use of CSL112 with alirocumab and/or atorvastatin with no anticipated negative impact on liver safety and TK.

HDL biodistribution and brain receptors in zebrafish, using HDLs as vectors for targeting endothelial cells and neural progenitors.

High density lipoproteins (HDLs) display pleiotropic functions such as anti-inflammatory, antioxidant, anti-protease, and anti-apoptotic properties. These effects are mediated by four main receptors: SCARB1 (SR-BI), ABCA1, ABCG1, and CD36. Recently, HDLs have emerged for their potential involvement in brain functions, considering their epidemiological links with cognition, depression, and brain plasticity. However, their role in the brain is not well understood. Given that the zebrafish is a well-recognized model for studying brain plasticity, metabolic disorders, and apolipoproteins, it could represent a good model for investigating the role of HDLs in brain homeostasis. By analyzing RNA sequencing data sets and performing in situ hybridization, we demonstrated the wide expression of scarb1, abca1a, abca1b, abcg1, and cd36 in the brain of adult zebrafish. Scarb1 gene expression was detected in neural stem cells (NSCs), suggesting a possible role of HDLs in NSC activity. Accordingly, intracerebroventricular injection of HDLs leads to their uptake by NSCs without modulating their proliferation. Next, we studied the biodistribution of HDLs in the zebrafish body. In homeostatic conditions, intraperitoneal injection of HDLs led to their accumulation in the liver, kidneys, and cerebral endothelial cells in zebrafish, similar to that observed in mice. After telencephalic injury, HDLs were diffused within the damaged parenchyma and were taken up by ventricular cells, including NSCs. However, they failed to modulate the recruitment of microglia cells at the injury site and the injury-induced proliferation of NSCs. In conclusion, our results clearly show a functional HDL uptake process involving several receptors that may impact brain homeostasis and suggest the use of HDLs as delivery vectors to target NSCs for drug delivery to boost their neurogenic activity.

An 89Zr-HDL PET Tracer Monitors Response to a CSF1R Inhibitor.

The immune function within the tumor microenvironment has become a prominent therapeutic target, with tumor-associated macrophages (TAMs) playing a critical role in immune suppression. We propose an 89Zr-labeled high-density lipoprotein (89Zr-HDL) nanotracer as a means of monitoring response to immunotherapy. Methods: Female MMTV-PyMT mice were treated with pexidartinib, a colony-stimulating factor 1 receptor (CSF1R) inhibitor, to reduce TAM density. The accumulation of 89Zr-HDL within the tumor was assessed using PET/CT imaging and autoradiography, whereas TAM burden was determined using immunofluorescence. Results: A significant reduction in 89Zr-HDL accumulation was observed in PET/CT images, with 2.9% ± 0.3% and 3.7% ± 0.2% injected dose/g for the pexidartinib- and vehicle-treated mice, respectively. This reduction was corroborated ex vivo and correlated with decreased TAM density. Conclusion: These results support the potential use of 89Zr-HDL nanoparticles as a PET tracer to quickly monitor the response to CSF1R inhibitors and other therapeutic strategies targeting TAMs.

Phospholipid Component Defines Pharmacokinetic and Pharmacodynamic Properties of Synthetic High-Density Lipoproteins.

Synthetic high-density lipoprotein (sHDL) nanoparticles composed of apolipoprotein A-I mimetic peptide and phospholipids have been shown to reduce atherosclerosis in animal models. Cholesterol is mobilized from atheroma macrophages by sHDL into the blood compartment and delivered to the liver for elimination. Historically, sHDL drug discovery efforts were focused on optimizing peptide sequences for interaction with cholesterol cellular transporters rather than understanding how both sHDL components, peptide and lipid, influence its pharmacokinetic and pharmacodynamic profiles. We designed two sets of sHDL having either identical phospholipid but variable peptide sequences with different plasma stability or identical peptide and phospholipids with variable fatty acid chain length and saturation. We found that sHDL prepared with proteolytically stable 22A-P peptide had 2-fold longer circulation half-time relative to the less stable 22A peptide. Yet, longer half-life did not translate into any improvement in cholesterol mobilization. In contrast, sHDL with variable phospholipid compositions showed significant differences in phospholipid PK, with distearoyl phosphatidylcholine-based sHDL demonstrating the longest half-life of 6.0 hours relative to 1.0 hour for palmitoyl-oleoyl phosphatidylcholine-based sHDL. This increase in half-life corresponded to an approx. 6.5-fold increase in the area under the curve for the mobilized cholesterol. Therefore, the phospholipid component in sHDL plays a major role in cholesterol mobilization in vivo and should not be overlooked in the design of future sHDL. SIGNIFICANCE STATEMENT: The phospholipid composition in sHDL plays a critical role in determining half-life and cholesterol mobilization in vivo.

Rational Design of Lovastatin-Loaded Spherical Reconstituted High Density Lipoprotein for Efficient and Safe Anti-Atherosclerotic Therapy.

Reconstituted high density lipoprotein (rHDL) is a biomimetic nanoparticle with plaque targeting and anti-atherosclerotic efficacy. In this work, we report on a strategy to rational design of lovastatin (LOV)-loaded spherical rHDL (LOV-s-rHDL) for efficient and safe anti-atherosclerotic therapy. Briefly, three LOV-s-rHDLs were formulated with LOV/s-rHDL at ratios of 8:1, 10:1, and 15:1 upon their respective median-effect values ( Dm). The combined inhibitory effect between LOV and s-rHDL of different LOV-s-rHDL formulations on DiI-labeled oxLDL internalization was systemically investigated in RAW 264.7 cells based on the median-effect principle. Median-effect analysis demonstrated that the optimized LOV-s-rHDL was formulated with a ratio of 10:1 ( Dm LOV: Dm s-rHDL), in which LOV and s-rHDL carrier showed the best synergistic effect, presumably ascribed to their inhibitory effect on CD36 and SR-A expression according to the Western blot analysis. In vivo pharmacodynamics studies showed that the optimized LOV-s-rHDL displayed the most pronounced anti-atherosclerotic effect on decreasing plaque area and reducing the MMP level following an 8-week dosing regimen. In vivo atherosclerotic plaque targeting analysis revealed that s-rHDL had potent plaque targeting efficacy, probably owing to the interaction between apoA-I and scavenger receptor B-I. Furthermore, we observed that the optimized LOV-s-rHDL exhibited a favorable safety profile as evidenced by the results of a hemolysis assay, cell cytotoxicity study, and in vivo safety test. Collectively, the rational design of the biomimetic LOV-s-rHDL based on the median-effect analysis provides an efficient strategy to achieve a synergistic and safe anti-atherosclerotic therapy.

Reassembly of native components with donepezil to execute dual-missions in Alzheimer's disease therapy.

Alzheimer's disease (AD) is a multifaceted and progressive neurodegenerative disease characterized by accumulation of amyloid-beta (Aß) and deficits of acetylcholine. Accordingly, the intra-/extra-cerebral level of high density lipoprotein (HDL) is crucial on the pathogenesis of AD; and most of all, various HDL-protein subtypes play a double-edged role in AD pathology, of which apolipoprotein A-I (apoA-I) gives protective outcomes. Inspired from "HDL bionics", we proposed biologically reassembled nanodrugs, donepezil-loaded apolipoprotein A-I-reconstituted HDL (rHDL/Do) that concurrently executed dual-missions of Aß-targeting clearance and acetylcholinesterase (AChE) inhibition in AD therapy. Once prepared, rHDL/Do nanodrug achieved high drug encapsulation efficiency of 90.47%, and mimicked the configurations and properties of natural lipoproteins aiming to significantly enhance BBB penetration and modulate Aß-induced neuronal damage both in vitro and in vivo. Surface plasmon resonance (SPR) analysis confirmed that rHDL/Do facilitated microglial-mediated Aß intake and degradation, demonstrating low KD value with Aß affinity (2.45 × 10-8 of Aß monomer and 2.78 × 10-8 of Aß oligomer). In AD animal models, daily treatment of rHDL/Do efficiently inhibited AChE activity, ameliorated neurologic variation, promoted Aß clearance, and rescued memory loss at a safe level. The collective findings indicated that the biological nanodrug was provided with the capacities of BBB penetration, Aß capture and degradation via microglial cells, and cholinergic dysfunction amelioration after controlled donepezil release. In summary, rHDL/Do nanodrugs could offer a promising strategy to synergize both symptom control and disease modification in AD therapy.

Benefits of hypericin transport and delivery by low- and high-density lipoproteins to cancer cells: From in vitro to ex ovo.

Lipoproteins are very attractive natural-based transport systems suitable for applications in diagnostics and cancer therapy. Low- and high-density lipoproteins (LDL, HDL) were selected for hypericin (hyp) delivery in cancer cells. Hyp was used, as it is a well-known model for hydrophobic molecules, in order to estimate the LDL and HDL transport efficacy. We applied fluorescence techniques, absorption and Raman spectroscopy to characterize the state and alteration of LDL and HDL in the absence and presence of hyp. The fluorescence intensity of hyp loaded in lipoproteins was two times weaker in HDL than LDL. We demonstrated that there are faster redistribution kinetics of hyp from HDL than from LDL. As a consequence, hyp uptake by glioma and breast cancer cells was driven more via endocytosis when hyp was delivered by LDL than by HDL. Hyp induced photodynamic action was stronger when hyp was delivered by HDL than LDL. Ex ovo hyp fluorescence pharmacokinetics demonstrated differences in biodistributions of hyp in lipoproteins topical applications. However, hyp was successfully delivered to cancer cells grafted on quail's chorioallantoic membrane. The results presented in this paper could provide strategies to develop adequate and targeted anticancer therapy.

Moderate Renal Impairment Does Not Impact the Ability of CSL112 (Apolipoprotein A-I [Human]) to Enhance Cholesterol Efflux Capacity.

CSL112 (apolipoprotein A-I [human]) is a novel intravenous formulation of plasma-derived apolipoprotein A-I (apoA-I) that enhances cholesterol efflux capacity. Renal impairment is a common comorbidity in acute myocardial infarction patients and is associated with impaired lipid metabolism. The aim of this phase 1 study was to assess the impact of moderate renal impairment on the pharmacokinetic and pharmacodynamic profile of CSL112. Sixteen subjects with moderate renal impairment and 16 age-, sex-, and weight-matched subjects with normal renal function participated in the study. Within each renal function cohort, subjects were randomized 3:1 to receive a single intravenous infusion of CSL112 2 g (n = 6) or placebo (n = 2) or CSL112 6 g (n = 6) or placebo (n = 2). At baseline, subjects with moderate renal impairment versus normal renal function had higher total cholesterol efflux, ABCA1-dependent cholesterol efflux capacity, and pre-ß1-high-density lipoprotein (HDL) levels. Infusing CSL112 resulted in similar, immediate, robust, dose-dependent elevations in apoA-I and cholesterol efflux capacity in both renal function cohorts and significantly greater elevations in pre-ß1-HDL (P < .05) in moderate renal impairment. Lecithin-cholesterol acyltransferase activity, demonstrated by a time-dependent change in the ratio of unesterified to esterified cholesterol, did not differ by renal function. No meaningful changes in proatherogenic lipid levels were observed. Moderate renal impairment did not impact the ability of CSL112 to enhance cholesterol efflux capacity. CSL112 may represent a novel therapy to reduce the risk of early recurrent cardiovascular events following acute myocardial infarction in patients with or without moderate renal impairment.

Pharmacokinetics and Safety of CSL112 (Apolipoprotein A-I [Human]) in Adults With Moderate Renal Impairment and Normal Renal Function.

CSL112 (Apolipoprotein A-I [human]) is an intravenous preparation of apolipoprotein A-I (apoA-I), formulated with phosphatidylcholine (PC) and stabilized with sucrose, in development to prevent early recurrent cardiovascular events following acute myocardial infarction (AMI). This phase 1 study was designed to determine if moderate renal impairment (RI) influenced the pharmacokinetics (PK) and safety of CSL112. Thirty-two subjects, 16 with moderate RI (estimated glomerular filtration rate [eGFR] ≥ 30 and < 60 mL/min/1.73 m2 ) and 16 age-, sex-, and weight-matched subjects with normal renal function (eGFR ≥ 90 mL/min/1.73 m2 ) were randomized 3:1 to receive a single infusion of CSL112 2 g (n = 6) or placebo (n = 2), or CSL112 6 g (n = 6) or placebo (n = 2). PK sampling was at prespecified times from 48 hours prior to 144 hours following infusions, with final safety assessments at 90 days. Renal and hepatic safety, and adverse events (AEs) were monitored throughout the study. Plasma apoA-I and PC PK profiles were similar between renal function cohorts at both doses. For CSL112 6 g mean ± SD apoA-I AUC0-last was 7670 ± 1900 and 9170 ± 2910 mg·h/dL in normal renal function and moderate RI subjects, respectively. Renal apoA-I clearance was <1% of CSL112 dose. In moderate RI, sucrose clearance was slower; however, approximately 70% was excreted within 48 hours in both renal function cohorts. No CSL112-related serious AEs or clinically significant renal or hepatic safety changes were observed. Dose adjustment of CSL112 is not required in subjects with moderate RI, supporting its further investigation in AMI patients with moderate RI.

A dual-targeting reconstituted high density lipoprotein leveraging the synergy of sorafenib and antimiRNA21 for enhanced hepatocellular carcinoma therapy.

Sorafenib (So) is a multi-target kinase inhibitor extensively used in clinic for hepatocellular carcinoma therapy. It demonstrated strong inhibition both in tumor proliferation and tumor angiogenesis, while hampered by associated cutaneous side-effect and drug resistance. The knockdown of miR-21 with antisense oligonucleotides (antimiRNA21) was regarded as an efficient strategy for increasing tumor sensibility to chemotherapy, which could be employed to appreciate the efficacy of So. Herein, we successfully formulated a dual-targeting delivery system for enhanced hepatocellular carcinoma therapy by encapsulating So and antimiRNA21 in RGD pentapeptide-modified reconstituted high-density lipoprotein (RGD-rHDL/So/antimiRNA21). The RGD and apolipoprotein A-I (ApoA-I) on nanoparticles (NPs) could drive the system simultaneously to tumor neovascular and parenchyma by binding to the overexpressed ανß3-integrin and SR-B1 receptors, achieving precise delivery of therapeutics to maximize the efficacy. A series in vitro and in vivo experiments revealed that co-delivery of So and antimiRNA21 by RGD-rHDL significantly strengthened the anti-tumor and anti-angiogenic effect of So with negligible toxicity towards major organs, reversed drug-resistance and was capable of remodeling tumor environments. The constructed RGD-rHDL/So/antimiRNA21 with improved efficacy and excellent tumor targeting ability provided new idea for chemo-gene combined therapy in hepatocellular carcinoma. STATEMENT OF SIGNIFICANCE: Sorafenib (So) is a multi-target kinase inhibitor which was approved by FDA as first-line drug for hepatocellular carcinoma (HCC) therapy. However, long term application of So in clinic was hampered by serious dermal toxicity and drug resistance. Although numerous researchers were devoted to finding alternatives or therapies as combination treatments with So to reach more desired therapeutic efficacy, the therapeutic options were still limited. The present study prepares RGD pentapeptide decorated biomimic reconstituted high-density lipoprotein (rHDL) loaded with So and antimiRNA21 (RGD-rHDL/So/antimiRNA21) for enhanced HCC therapy. The RGD-rHDL/So/antimiRNA21 NPs offer an effective platform for anti-tumor and anti-angiogenesis therapy in HCC and provide new approach to reverse drug-resistance of So for feasible clinical application.

Evaluation of the Combined Effect of Recombinant High-Density Lipoprotein Carrier and the Encapsulated Lovastatin in RAW264.7 Macrophage Cells Based on the Median-Effect Principle.

Recombinant high-density lipoprotein (rHDL) displays a similar anti-atherosclerotic effect with native HDL and could also be served as a carrier of cardiovascular drug for atherosclerotic plaque targeting. In our previous studies, rHDL has shown a more potent anti-atherosclerotic efficacy as compared to the other conventional nanoparticles with a payload of lovastatin (LS). Therefore, we hypothesized that a synergistic anti-atherosclerotic effect of the rHDL carrier and the encapsulated LS might exist. In this study, the dose-effect relationships and the combined effect of the rHDL and LS were quantitatively evaluated in RAW 264.7 macrophage cells using the median-effect analysis, in which the rHDL carrier was regarded as a drug combined. Median-effect analysis suggested that rHDL and LS exerted a desirable synergistic inhibition on the oxLDL internalization at a ratio of 6:1 ( Dm,LS: Dm,rHDL) in RAW 264.7 macrophage cells. About 50% of the reduction on the intracellular lipid contents was found when RAW264.7 cells were treated with LS-loaded rHDLs at their respective median-effect dose ( Dm) concentrations and a synergistic effect on the mediating cholesterol efflux was also observed, which verified the accuracy of the results obtained from the median-effect analysis. The mechanism underlying the synergistic effect of the rHDL carrier and the drug might be attributed to their potent inhibitory effects on SR-A expression. In conclusion, the median-effect analysis was proven to be a feasible method to quantitatively evaluate the synergistic effect of the biofunctional carrier and the drug encapsulated.

CSL112 (Apolipoprotein A-I [Human]) Enhances Cholesterol Efflux Similarly in Healthy Individuals and Stable Atherosclerotic Disease Patients.

OBJECTIVE: CSL112 (apolipoprotein A-I [apoA-I; human]) is a novel formulation of apoA-I in development for reduction of early recurrent cardiovascular events after acute myocardial infarction. Cholesterol efflux capacity (CEC) is a marker of high-density lipoprotein (HDL) function that is strongly correlated with incident cardiovascular disease. Impaired CEC has been observed in patients with coronary heart disease. Here, we determined whether infused apoA-I improves CEC when administered to patients with stable atherosclerotic disease versus healthy volunteers. APPROACH AND RESULTS: Measurements of apoA-I, HDL unesterified cholesterol, HDL esterified cholesterol, pre-ß1-HDL, and CEC were determined in samples from patients with stable atherosclerotic disease before and after intravenous administration of CSL112. These measures were compared with 2 prior studies in healthy volunteers for differences in CEC at baseline and after CSL112 infusion. Patients with stable atherosclerotic disease exhibited significantly lower ATP-binding cassette transporter 1-mediated CEC at baseline (P<0.0001) despite slightly higher apoA-I levels when compared with healthy individuals (2 phase 1 studies pooled; P≤0.05), suggesting impaired HDL function. However, no differences were observed in apoA-I pharmacokinetics or in pre-ß1-HDL (P=0.5) or CEC (P=0.1) after infusion of CSL112. Similar elevation in CEC was observed in patients with low or high baseline HDL function (based on tertiles of apoA-I-normalized CEC; P=0.1242). These observations were extended and confirmed using cholesterol esterification as an additional measure. CONCLUSIONS: CSL112 shows comparable, strong, and immediate effects on CEC despite underlying cardiovascular disease. CSL112 is, therefore, a promising novel therapy for lowering the burden of atherosclerosis and reducing the risk of recurrent cardiovascular events.

Apolipoprotein E3-mediated cellular uptake of reconstituted high-density lipoprotein bearing core 3, 10, or 17 nm hydrophobic gold nanoparticles.

We have developed a high-density lipoprotein (HDL)-based platform for transport and delivery of hydrophobic gold nanoparticles (AuNPs). The ability of apolipoprotein E3 (apoE3) to act as a high-affinity ligand for the low-density lipoprotein receptor (LDLr) was exploited to gain entry of HDL with AuNPs into glioblastoma cells. AuNPs of 3, 10, and 17 nm diameter, the latter two synthesized by phase transfer process, were solubilized by integration with phospholipids and apoE3, yielding reconstituted HDL (rHDL) bearing AuNPs. Ultraviolet-visible spectra of rHDL-AuNP indicated the presence of stable particles with surface plasmon band at ~530 nm. Transmission electron microscopy (TEM) of rHDL-AuNP revealed roughly spherical particles with AuNPs embedded in the core. The rHDL-AuNP particles displayed robust binding to the LDLr and were internalized by receptor-mediated endocytosis in glioblastoma cells. Confocal microscopy confirmed cellular uptake of AuNPs in the endosomal-lysosomal compartments, while TEM revealed intracellular aggregated AuNPs. Cell viability assay demonstrated that >85% of cells were viable with rHDL-AuNP treatment of 0.1-100 µg/mL for 24 hours. These findings are significant since they offer an effective means of delivering AuNPs across the cell membrane, which is particularly relevant in tumor cells that overexpress LDLr.

A systematic comparison of clinically viable nanomedicines targeting HMG-CoA reductase in inflammatory atherosclerosis.

Atherosclerosis is a leading cause of worldwide morbidity and mortality whose management could benefit from novel targeted therapeutics. Nanoparticles are emerging as targeted drug delivery systems in chronic inflammatory disorders. To optimally exploit nanomedicines, understanding their biological behavior is crucial for further development of clinically relevant and efficacious nanotherapeutics intended to reduce plaque inflammation. Here, three clinically relevant nanomedicines, i.e., high-density lipoprotein ([S]-HDL), polymeric micelles ([S]-PM), and liposomes ([S]-LIP), that are loaded with the HMG-CoA reductase inhibitor simvastatin [S], were evaluated in the apolipoprotein E-deficient (Apoe-/-) mouse model of atherosclerosis. We systematically employed quantitative techniques, including in vivo positron emission tomography imaging, gamma counting, and flow cytometry to evaluate the biodistribution, nanomedicines' uptake by plaque-associated macrophages/monocytes, and their efficacy to reduce macrophage burden in atherosclerotic plaques. The three formulations demonstrated distinct biological behavior in Apoe-/- mice. While [S]-PM and [S]-LIP possessed longer circulation half-lives, the three platforms accumulated to similar levels in atherosclerotic plaques. Moreover, [S]-HDL and [S]-PM showed higher uptake by plaque macrophages in comparison to [S]-LIP, while [S]-PM demonstrated the highest uptake by Ly6Chigh monocytes. Among the three formulations, [S]-PM displayed the highest efficacy in reducing macrophage burden in advanced atherosclerotic plaques. In conclusion, our data demonstrate that [S]-PM is a promising targeted drug delivery system, which can be advanced for the treatment of atherosclerosis and other inflammatory disorders in the clinical settings. Our results also emphasize the importance of a thorough understanding of nanomedicines' biological performance, ranging from the whole body to the target cells, as well drug retention in the nanoparticles. Such systematic investigations would allow rational applications of nanomaterials', beyond cancer, facilitating the expansion of the nanomedicine horizon.

Safety and Tolerability of CSL112, a Reconstituted, Infusible, Plasma-Derived Apolipoprotein A-I, After Acute Myocardial Infarction: The AEGIS-I Trial (ApoA-I Event Reducing in Ischemic Syndromes I).

BACKGROUND: Human or recombinant apolipoprotein A-I (apoA-I) has been shown to increase high-density lipoprotein-mediated cholesterol efflux capacity and to regress atherosclerotic disease in animal and clinical studies. CSL112 is an infusible, plasma-derived apoA-I that has been studied in normal subjects or those with stable coronary artery disease. This study aimed to characterize the safety, tolerability, pharmacokinetics, and pharmacodynamics of CSL112 in patients with a recent acute myocardial infarction. METHODS: The AEGIS-I trial (Apo-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b trial. Patients with myocardial infarction were stratified by renal function and randomized 1:1:1 to CSL112 (2 g apoA-I per dose) and high-dose CSL112 (6 g apoA-I per dose), or placebo for 4 consecutive weekly infusions. Coprimary safety end points were occurrence of either a hepatic safety event (an increase in alanine transaminase >3 times the upper limit of normal or an increase in total bilirubin >2 times the upper limit of normal) or a renal safety event (an increase in serum creatinine >1.5 times the baseline value or a new requirement for renal replacement therapy). RESULTS: A total of 1258 patients were randomized, and 91.2% received all 4 infusions. The difference in incidence rates for an increase in alanine transaminase or total bilirubin between both CSL112 arms and placebo was within the protocol-defined noninferiority margin of 4%. Similarly, the difference in incidence rates for an increase in serum creatinine or a new requirement for renal replacement therapy was within the protocol-defined noninferiority margin of 5%. CSL112 was associated with increases in apoA-I and ex vivo cholesterol efflux similar to that achieved in patients with stable coronary artery disease. In regard to the secondary efficacy end point, the risk for the composite of major adverse cardiovascular events among the groups was similar. CONCLUSIONS: Among patients with acute myocardial infarction, 4 weekly infusions of CSL112 are feasible, well tolerated, and not associated with any significant alterations in liver or kidney function or other safety concern. The ability of CSL112 to acutely enhance cholesterol efflux was confirmed. The potential benefit of CSL112 to reduce major adverse cardiovascular events needs to be assessed in an adequately powered phase 3 trial. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT02108262.

Biomimetic HDL nanoparticle mediated tumor targeted delivery of indocyanine green for enhanced photodynamic therapy.

Photodynamic therapy has emerged as a promising strategy for cancer treatment. To ensure the efficient delivery of a photosensitizer to tumor for anticancer effect, a safe and tumor-specific delivery system is highly desirable. Herein, we introduce a novel biomimetic nanoparticle named rHDL/ICG (rHDL/I), by loading amphiphilic near-infrared (NIR) fluorescent dye indocyanine green (ICG) into reconstituted high density lipoproteins (rHDL). In this system, rHDL can mediate photoprotection effect and receptor-guided tumor-targeting transportation of cargos into cells. Upon NIR irradiation, ICG can generate fluorescent imaging signals for diagnosis and monitoring therapeutic activity, and produce singlet oxygen to trigger photodynamic therapy (PDT). Our studies demonstrated that rHDL/I exhibited excellent size and fluorescence stability, light-triggered controlled release feature, and neglectable hemolytic activity. It also showed equivalent NIR response compared to free ICG under laser irradiation. Importantly, the fluorescent signal of ICG loaded in rHDL/I could be visualized subcellularly in vitro and exhibited metabolic distribution in vivo, presenting superior tumor targeting and internalization. This NIR-triggered image-guided nanoparticle produced outstanding therapeutic outcomes against cancer cells, demonstrating great potential of biomimetic delivery vehicles in future clinical practice.

In Vivo PET Imaging of HDL in Multiple Atherosclerosis Models.

OBJECTIVES: The goal of this study was to develop and validate a noninvasive imaging tool to visualize the in vivo behavior of high-density lipoprotein (HDL) by using positron emission tomography (PET), with an emphasis on its plaque-targeting abilities. BACKGROUND: HDL is a natural nanoparticle that interacts with atherosclerotic plaque macrophages to facilitate reverse cholesterol transport. HDL-cholesterol concentration in blood is inversely associated with risk of coronary heart disease and remains one of the strongest independent predictors of incident cardiovascular events. METHODS: Discoidal HDL nanoparticles were prepared by reconstitution of its components apolipoprotein A-I (apo A-I) and the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine. For radiolabeling with zirconium-89 ((89)Zr), the chelator deferoxamine B was introduced by conjugation to apo A-I or as a phospholipid-chelator (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-deferoxamine B). Biodistribution and plaque targeting of radiolabeled HDL were studied in established murine, rabbit, and porcine atherosclerosis models by using PET combined with computed tomography (PET/CT) imaging or PET combined with magnetic resonance imaging. Ex vivo validation was conducted by radioactivity counting, autoradiography, and near-infrared fluorescence imaging. Flow cytometric assessment of cellular specificity in different tissues was performed in the murine model. RESULTS: We observed distinct pharmacokinetic profiles for the two (89)Zr-HDL nanoparticles. Both apo A-I- and phospholipid-labeled HDL mainly accumulated in the kidneys, liver, and spleen, with some marked quantitative differences in radioactivity uptake values. Radioactivity concentrations in rabbit atherosclerotic aortas were 3- to 4-fold higher than in control animals at 5 days' post-injection for both (89)Zr-HDL nanoparticles. In the porcine model, increased accumulation of radioactivity was observed in lesions by using in vivo PET imaging. Irrespective of the radiolabel's location, HDL nanoparticles were able to preferentially target plaque macrophages and monocytes. CONCLUSIONS: (89)Zr labeling of HDL allows study of its in vivo behavior by using noninvasive PET imaging, including visualization of its accumulation in advanced atherosclerotic lesions. The different labeling strategies provide insight on the pharmacokinetics and biodistribution of HDL's main components (i.e., phospholipids, apo A-I).

High-Density Lipoproteins: Nature's Multifunctional Nanoparticles.

High-density lipoproteins (HDL) are endogenous nanoparticles involved in the transport and metabolism of cholesterol, phospholipids, and triglycerides. HDL is well-known as the "good" cholesterol because it not only removes excess cholesterol from atherosclerotic plaques but also has anti-inflammatory and antioxidative properties, which protect the cardiovascular system. Circulating HDL also transports endogenous proteins, vitamins, hormones, and microRNA to various organs. Compared with other synthetic nanocarriers, such as liposomes, micelles, and inorganic and polymeric nanoparticles, HDL has unique features that allow them to deliver cargo to specific targets more efficiently. These attributes include their ultrasmall size (8-12 nm in diameter), high tolerability in humans (up to 8 g of protein per infusion), long circulating half-life (12-24 h), and intrinsic targeting properties to different recipient cells. Various recombinant ApoA proteins and ApoA mimetic peptides have been recently developed for the preparation of reconstituted HDL that exhibits properties similar to those of endogenous HDL and has a potential for industrial scale-up. In this review, we will summarize (a) clinical pharmacokinetics and safety of reconstituted HDL products, (b) comparison of HDL with inorganic and other organic nanoparticles,

GM1-Modified Lipoprotein-like Nanoparticle: Multifunctional Nanoplatform for the Combination Therapy of Alzheimer's Disease.

Alzheimer's disease (AD) exerts a heavy health burden for modern society and has a complicated pathological background. The accumulation of extracellular ß-amyloid (Aß) is crucial in AD pathogenesis, and Aß-initiated secondary pathological processes could independently lead to neuronal degeneration and pathogenesis in AD. Thus, the development of combination therapeutics that can not only accelerate Aß clearance but also simultaneously protect neurons or inhibit other subsequent pathological cascade represents a promising strategy for AD intervention. Here, we designed a nanostructure, monosialotetrahexosylganglioside (GM1)-modified reconstituted high density lipoprotein (GM1-rHDL), that possesses antibody-like high binding affinity to Aß, facilitates Aß degradation by microglia, and Aß efflux across the blood-brain barrier (BBB), displays high brain biodistribution efficiency following intranasal administration, and simultaneously allows the efficient loading of a neuroprotective peptide, NAP, as a nanoparticulate drug delivery system for the combination therapy of AD. The resulting multifunctional nanostructure, αNAP-GM1-rHDL, was found to be able to protect neurons from Aß(1-42) oligomer/glutamic acid-induced cell toxicity better than GM1-rHDL in vitro and reduced Aß deposition, ameliorated neurologic changes, and rescued memory loss more efficiently than both αNAP solution and GM1-rHDL in AD model mice following intranasal administration with no observable cytotoxicity noted. Taken together, this work presents direct experimental evidence of the rational design of a biomimetic nanostructure to serve as a safe and efficient multifunctional nanoplatform for the combination therapy of AD.