Deep vein thrombosis, the development of blood clots in the peripheral veins, is a very serious, life threatening condition that is prevalent in the elderly. To deliver proper treatment that enhances the survival rate, it is very important to detect thrombi early and at the point of care. We explored the ability of magnetic particle spectroscopy (MSB) to detect thrombus via specific binding of aptamer functionalized magnetic nanoparticles with the blood clot. MSB uses the harmonics produced by nanoparticles in an alternating magnetic field to measure the rotational freedom and, therefore, the bound state of the nanoparticles. The nanoparticles’ relaxation time for Brownian rotation increases when bound [A.M. Rauwerdink and J. B. Weaver, Appl. Phys. Lett. 96, 1 (2010)]. The relaxation time can therefore be used to characterize the nanoparticle binding to thrombin in the blood clot. For longer relaxation times, the approach to saturation is more gradual reducing the higher harmonics and the harmonic ratio. The harmonic ratios of nanoparticles conjugated with anti-thrombin aptamers (ATP) decrease significantly over time with blood clot present in the sample medium, compared with nanoparticles without ATP. Moreover, the blood clot removed from the sample medium produced a significant MSB signal, indicating the nanoparticles are immobilized on the clot. Our results show that MSB could be a very useful non-invasive, quick tool to detect blood clots at the point of care so proper treatment can be used to reduce the risks inherent in deep vein thrombosis.

Cholesterol is essential for cellular function and is stored as cholesteryl esters (CEs). CEs biosynthesis is catalyzed by the enzymes acyl-CoA:cholesterol acyltransferase 1 and 2 (ACAT1 and ACAT2), with ACAT1 being the primary isoenzyme in most cells in humans. In Alzheimer’s Disease, CEs accumulate in vulnerable brain regions. Therefore, ACATs may be promising targets for treating AD. F12511 is a high-affinity ACAT1 inhibitor that has passed phase 1 safety tests for antiatherosclerosis. Previously, we developed a nanoparticle system to encapsulate a large concentration of F12511 into a stealth liposome (DSPE-PEG₂₀₀₀ with phosphatidylcholine). Here, we injected the nanoparticle encapsulated F12511 (nanoparticle F) intravenously (IV) in wild-type mice and performed an HPLC/MS/MS analysis and ACAT enzyme activity measurement. The results demonstrated that F12511 was present within the mouse brain after a single IV but did not overaccumulate in the brain or other tissues after repeated IVs. A histological examination showed that F12511 did not cause overt neurological or systemic toxicity. We then showed that a 2-week IV delivery of nanoparticle F to aging 3xTg AD mice ameliorated amyloidopathy, reduced hyperphosphorylated tau and nonphosphorylated tau, and reduced neuroinflammation. This work lays the foundation for nanoparticle F to be used as a possible therapy for AD and other neurodegenerative diseases.

Background: Sunitinib is a multi‐target tyrosine kinase inhibitor (TKI) that inhibits VEGF receptor 1, 2, 3 (VEGFRs), platelet‐derived growth factor receptor (PDGFR), colony‐stimulating factor receptor (CSFR), and the stem cell factor receptor c‐KIT. Temsirolimus inhibits mammalian target of rapamycin (mTOR) through binding to intracellular protein FKBP‐12. Both agents are approved for the treatment of metastatic renal cell carcinoma (mRCC), have different anticancer mechanisms, and non‐overlapping toxicities. These attributes form the scientific rationale for sequential combination of these agents. The primary objective of the study was to investigate the efficacy of alternating sunitinib and temsirolimus therapy on progression‐free survival (PFS) in mRCC.Methods: We undertook a phase II, multi‐center, single cohort, open‐label study in patients with mRCC. Patients were treated with alternating dosing of 4 weeks of sunitinib 50 mg PO daily, followed by 2 weeks rest, then 4 weeks of temsirolimus 25 mg IV weekly, followed by 2 weeks rest (12 weeks total per cycle). The primary endpoint was PFS. Secondary endpoints included clinical response rate and characterization of the toxicity profile of this combination therapy.Results: Nineteen patients were enrolled into the study. The median observed PFS (n = 13 evaluable for PFS) was 8.8 months (95% CI 6.8–25.2 months). Best responses achieved were five partial response, nine stable disease, and three disease progression according to RECIST 1.1 guidelines (two non‐evaluable). The most commonly observed toxicities were fatigue, platelet count decrease, creatinine increased, diarrhea, oral mucositis, edema, anemia, rash, hypophosphatemia, dysgeusia, and palmar‐plantar erythrodysesthesia syndrome.Conclusion: Alternating sunitinib and temsirolimus did not improve the PFS in patients with mRCC.

Cholesterol is essential to cellular function and is stored as cholesteryl esters (CEs). CEs biosynthesis is responsible by the enzymes acyl-CoA: cholesterol acyltransferase 1 and 2 (ACAT1 and ACAT2), with ACAT1 as the primary isoenzyme in most cells in humans. ACATs are targets for atherosclerosis therapies and may also be promising targets for treating Alzheimer’s Disease (AD). F12511 is a high-affinity ACAT1 inhibitor that has passed phase 1 safety tests for anti-atherosclerosis. Previously, we had developed a nanoparticle system to encapsulate a large concentration of F12511 into a stealth liposome (DSPE-PEG ₂₀₀₀ with egg phosphatidylcholine). Here, we injected the nanoparticle encapsulated F12511 (nanoparticle F) intravenously (IV) to wild-type (WT) mice and performed HPLC/MS/MS analysis and ACAT enzyme activity measurement. The results demonstrated that F12511 was present within the mouse brain after a single IV but did not over-accumulate in the brain or other tissues after repeated IVs. Histological examination showed that F12511 did not cause overt neurological or systemic toxicity. We then showed that 2-week IV delivery of nanoparticle F to aging 3xTg AD mice ameliorated amyloidopathy, reduced hyperphosphorylated tau and non-phosphorylated tau, and reduced neuroinflammation. This work lays the foundation with nanoparticle F as a possible therapy for AD and other neurodegenerative diseases.

Cholesterol homeostasis is pivotal for cellular function. Acyl-coenzyme A:cholesterol acyltransferase 1 (ACAT1), also abbreviated as SOAT1, is an enzyme responsible for catalyzing the storage of excess cholesterol to cholesteryl esters. ACAT1 is an emerging target to treat diverse diseases including atherosclerosis, cancer, and neurodegenerative diseases. F12511 is a high-affinity ACAT1 inhibitor. Previously, we developed a stealth liposome-based nanoparticle to encapsulate F12511 to enhance its delivery to the brain and showed its efficacy in treating a mouse model for Alzheimer’s disease (AD). In this study, we introduce F26, a close derivative of F12511 metabolite in rats. F26 was encapsulated in the same DSPE-PEG₂₀₀₀/phosphatidylcholine (PC) liposome-based nanoparticle system. We employed various in vitro and in vivo methodologies to assess F26’s efficacy and toxicity compared to F12511. The results demonstrate that F26 is more effective and durable than F12511 in inhibiting ACAT1, in both mouse embryonic fibroblasts (MEFs), and in multiple mouse tissues including the brain tissues, without exhibiting any overt systemic or neurotoxic effects. This study demonstrates the superior pharmacokinetic and safety profile of F26 in wild-type mice, and suggests its therapeutic potential against various neurodegenerative diseases including AD.