Antithrombotic functions of small molecule-capped gold nanoparticles

Nattokinase Encapsulated Nanomedicine for Targeted Thrombolysis: Development, Improved in Vivo Thrombolytic Effects, and Ultrasound/Photoacoustic Imaging

Nattokinase (NK), a potent thrombolytic enzyme that dissolves blood clots, is highly used in the treatment of cardiovascular disorders. However, its effective delivery remains demanding because of stability and bioavailability problems owing to its high molecular weight and proteineous nature. In this research, we have developed novel NK-loaded nontargeted liposomes (NK-LS) and targeted liposomes (RGD-NK-LS and AM-NK-LS) by the reverse phase evaporation method. The physiochemical characterizations (particle size, polydispersity index, zeta potential, and morphology) were performed by a Zetasizer, SEM, TEM, and AFM. The Bradford assay and XPS analysis confirmed the successful surface conjugation of the targeting ligands. Platelet interaction studies by CLSM, photon imager optima, and flow cytometry showed significantly higher (P < 0.05) platelet binding affinity of targeted liposomes. In vitro evaluations were performed using human blood and a fibrinolysis study by CLSM imaging demonstrating the potent antithrombotic efficacy of AM-NK-LS. Furthermore, bleeding and clotting time studies revealed that the targeted liposomes were free from any bleeding complications. Moreover, the in vivo FeCl3 model on Sprague-Dawley (SD) rats using a Doppler flow meter and ultrasound/photoacoustic imaging indicated the increased % thrombolysis and potent affinity of targeted liposomes toward the thrombus site. Additionally, in vitro hemocompatibility and histopathology studies demonstrated the safety and biocompatibility of the nanoformulations.

Surface Geometry of Cargo-less Gold Nanoparticles Is a Driving Force for Selective Targeting of Activated Neutrophils to Reduce Thrombosis in Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by recurrent arterial, venous, and microvascular thrombosis where activated neutrophils play a determinant role. However, neutrophils are challenging to target given their short lifespan in circulation and spontaneous activation. Screening of a small library of gold nanoparticles (AuNPs) led to the discovery of a formulation capable of targeting activated neutrophil attachment and has demonstrated that star-shaped, anti-PSGL-1-antibody-coated AuNPs (aPSGL-1-AuNPs) were more efficacious compared with other shapes of AuNPs. Our findings further revealed an exciting and safe targeting mode toward activated neutrophils in the APS mouse model induced by human-patient-derived antiphospholipid IgGs. Our studies demonstrate that targeting is dependent on the specific topographical features of the highly segregated PSGL-1 on the activated neutrophil surface for which a high affinity shape-driven nanomedicine can be designed and implemented. As such, star-shaped aPSGL-1-AuNPs serve as a promising nanoimmunotherapy for immunothrombosis associated with neutrophil adhesion in APS.

A Review of the Use of Metallic Nanoparticles as a Novel Approach for Overcoming the Stability Challenges of Blood Products: A Narrative Review from 2011-2021

PURPOSE

To obtain safe and qualified blood products (e.g., platelets, plasma, and red blood cells), various limitations such as limited shelf life (especially for platelets) and stability must be addressed. In this review study, the most commonly used metal nanomaterials (e.g., gold, silver, iron, and magnetic) reported in the literature from 2011 to 2021 were discussed owing to their unique properties, which provide exciting approaches to overcome these limitations and improve the stability, safety, and quality of blood products. Novelty: This study reviews for the first time the results of studies (from 2011 to 2021) that consider the effects of various metallic nanoparticles on the different blood products.

RESULTS

The results of this review study showed that some metallic nanoparticles are effective in improving the stability of plasma proteins. For this purpose, modified Fe₃O₄ magnetic nanoparticles and citrate-AuNPs protect albumin products against stressful situations. Also, SiO₂ microspheres and silicacoated magnetite nanoparticles are highly capable of improving IgG stability. ZnO nanoparticles also reduced thrombin production, and protein-coated GMNP nanoparticles prevented unwanted leakage of factor VIII through blood vessels. Furthermore, the stability and longevity of erythrocytes can be improved by AuNP nanoparticles and Zr-based organic nanoparticles. In addition, platelet storage time can be improved using PEGylated Au and functionalized iron oxide nanoparticles.

SUGGESTION

According to the results of this study, it is suggested that further research should be conducted on metal nanoparticles as the most promising candidates to prepare metal nanoparticles with improved properties to increase the stability of various blood products.

GPIIb/IIIa Receptor Targeted Rutin Loaded Liposomes for Site-Specific Antithrombotic Effect

Rutin (RUT) is a flavonoid obtained from a natural source and is reported for antithrombotic potential, but its delivery remains challenging because of its poor solubility and bioavailability. In this research, we have fabricated novel rutin loaded liposomes (RUT-LIPO, nontargeted), liposomes conjugated with RGD peptide (RGD-RUT-LIPO, targeted), and abciximab (ABX-RUT-LIPO, targeted) by ethanol injection method. The particle size, ζ potential, and morphology of prepared liposomes were analyzed by using DLS, SEM, and TEM techniques. The conjugation of targeting moiety on the surface of targeted liposomes was confirmed by XPS analysis and Bradford assay. In vitro assessment such as blood clot assay, aPTT assay, PT assay, and platelet aggregation analysis was performed using human blood which showed the superior antithrombotic potential of ABX-RUT-LIPO and RGD-RUT-LIPO liposomes. The clot targeting efficiency was evaluated by in vitro imaging and confocal laser scanning microscopy. A significant (P < 0.05) rise in the affinity of targeted liposomes toward activated platelets was demonstrated that revealed their remarkable potential in inhibiting thrombus formation. Furthermore, an in vivo study executed on Sprague Dawley rats (FeCl₃ model) demonstrated improved antithrombotic activity of RGD-RUT-LIPO and ABX-RUT-LIPO compared with pure drug. The pharmacokinetic study performed on rats demonstrates the increase in bioavailability when administered as liposomal formulation as compared to RUT. Moreover, the tail bleeding assay and clotting time study (Swiss Albino mice) indicated a better antithrombotic efficacy of targeted liposomes than control preparations. Additionally, biocompatibility of liposomal formulations was determined by an in vitro hemolysis study and cytotoxicity assay, which showed that they were hemocompatible and safe for human use. A histopathology study on rats suggested no severe toxicity of prepared liposomal formulations. Thus, RUT encapsulated nontargeted and targeted liposomes exhibited superior antithrombotic potential over RUT and could be used as a promising carrier for future use.

Iota-carrageenan/xyloglucan/serine powders loaded with tranexamic acid for simultaneously hemostatic, antibacterial, and antioxidant performance

This study sought to prepare powder hemostats based on iota-carrageenan (ιC), xyloglucan (XYL), l-serine (SER), and tranexamic acid (TA). The powder form was chosen because it enables the hemostat to be used in wounds of any shape and depth. The powder hemostats showed irregular shapes and specific surface areas ranging from 34 to 46 m²/g. Increasing TA amount decreases the specific surface area, bulk density, water and blood absorption, and the antibacterial activities of the powder hemostats, but not the water retention ability. Conversely, in vitro biodegradation was positively impacted by increasing the TA content in the powder hemostats. In both the in vitro and in vivo tests, powder hemostats showed reduced bleeding time, significant adhesion of red blood cells, great hemocompatibility, moderate antioxidant activity, and high biocompatibility. These findings shed new light on designing powder hemostats with intrinsic antibacterial and antioxidant activity and excellent hemostatic performance.

Rutin-Loaded Silver Nanoparticles With Antithrombotic Function

In this paper, we fabricated rutin-loaded silver nanoparticles (Rutin@AgNPs) as the nano-anticoagulant with antithrombotic function. The serum stability, anticoagulation activity, and bleeding risk of Rutin@AgNPs were evaluated. The results showed Rutin@AgNPs had good serum stability, hemocompatibility, and cytocompatibility. The anticoagulation activity of rutin was maintained, and its stability and aqueous solubility were improved. The Rutin@AgNPs could provide a sustained release to prolong the half-life of rutin. The results of the coagulation parameter assay and thrombus formation test in mice model showed that the activated partial thromboplastin time and prothrombin time were prolonged, and Rutin@AgNPs inhibited the thrombosis in the 48 h period. Moreover, the limited bleeding time indicated that the Rutin@AgNPs significantly minimized the hemorrhage risk of rutin. This Rutin@AgNPs is a potential anticoagulant for antithrombotic therapy.

Carbon Dot Nanoparticles Exert Inhibitory Effects on Human Platelets and Reduce Mortality in Mice with Acute Pulmonary Thromboembolism

The inhibition of platelet activation is considered a potential therapeutic strategy for the treatment of arterial thrombotic diseases; therefore, maintaining platelets in their inactive state has garnered much attention. In recent years, nanoparticles have emerged as important players in modern medicine, but potential interactions between them and platelets remain to be extensively investigated. Herein, we synthesized a new type of carbon dot (CDOT) nanoparticle and investigated its potential as a new antiplatelet agent. This nanoparticle exerted a potent inhibitory effect in collagen-stimulated human platelet aggregation. Further, it did not induce cytotoxic effects, as evidenced in a lactate dehydrogenase assay, and inhibited collagen-activated protein kinase C (PKC) activation and Akt (protein kinase B), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) phosphorylation. The bleeding time, a major side-effect of using antiplatelet agents, was unaffected in CDOT-treated mice. Moreover, our CDOT could reduce mortality in mice with ADP-induced acute pulmonary thromboembolism. Overall, CDOT is effective against platelet activation in vitro via reduction of the phospholipase C/PKC cascade, consequently suppressing the activation of MAPK. Accordingly, this study affords the validation that CDOT has the potential to serve as a therapeutic agent for the treatment of arterial thromboembolic disorders

Nanomaterials for the theranostics of obesity

As a chronic and lifelong disease, obesity not only significant impairs health but also dramatically shortens life span (at least 10 years). Obesity requires a life-long effort for the successful treatment because a number of abnormalities would appear in the development of obesity. Nanomaterials possess large specific surface area, strong absorptivity, and high bioavailability, especially the good targeting properties and adjustable release rate, which would benefit the diagnosis and treatment of obesity and obesity-related metabolic diseases. Herein, we discussed the therapy and diagnosis of obesity and obesity-related metabolic diseases by using nanomaterials. Therapies of obesity with nanomaterials include improving intestinal health and reducing energy intake, targeting and treating functional cell abnormalities, regulating redox homeostasis, and removing free lipoprotein in blood. Diagnosis of obesity-related metabolic diseases would benefit the therapy of these diseases. The development of nanomaterials will promote the diagnosis and therapy of obesity and obesity-related metabolic diseases.

Indole Derivative-Capped Gold Nanoparticles as an Effective Bactericide in Vivo

We synthesize indole derivative-capped gold nanoparticles (Au_IDs) via a straightforward route to fight multidrug-resistant (MDR) bacteria. When gold nanoparticles are modified with two indole derivatives, tryptophan and 5-aminoindole, they exhibit excellent antibacterial activities against both laboratory antibiotic-sensitive and MDR bacteria. Au_IDs possess remarkable bactericidal activities against MDR bacteria killing 99.9% of MDR Escherichia coli and polymyxin-resistant Klebsiella pneumoniae after 0.5 h of incubation, which are superior to clinical antibiotics including polymyxin B and cefotaxime. By evaluating the potential of Au_IDs in wound cure, Au_IDs show outstanding capability in MDR bacterial wound infection. Our findings provide new candidates for the development of bactericides and the fabrication of wound dressings for treating MDR infection.

Neuroprotective effect of gold nanoparticles composites in Parkinson's disease model

Parkinson's disease (PD) is second most common neurodegenerative disorder worldwide. Although drugs and surgery can relieve the symptoms of PD, these therapies are incapable of fundamentally treating the disease. For PD patients, over-expression of α-synuclein (SNCA) leads to the death of dopaminergic neurons. This process can be prevented by suppressing SNCA over-expression through RNA interference. Here, we successfully synthesized gold nanoparticles (GNP) composites (CTS@GNP-pDNA-NGF) via the combination of electrostatic adsorption and photochemical immobilization, which could load plasmid DNA (pDNA) and target specific cell types. GNP was transfected into cells via endocytosis to inhibiting the apoptosis of PC12 cells and dopaminergic neurons. Simultaneously, GNP composites are also used in PD models in vivo, and it can successfully cross the blood-brain barrier by contents of GNP in the mice brain. In general, all the works demonstrated that GNP composites have good therapeutic effects for PD models in vitro and in vivo.

Universal Coating from Electrostatic Self-Assembly to Prevent Multidrug-Resistant Bacterial Colonization on Medical Devices and Solid Surfaces

We provide a facile and scalable strategy for preparing gold nanoparticles (AuNPs)-based antibacterial coating on a variety of surfaces through electrostatic self-assembly. AuNPs conjugated with 4,6-diamino-2-pyrimidinethiol (DAPT, not antibacterial by itself), AuDAPT, can form stable coating on different substrates made from polyethylene (PS), polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polydimethylsiloxane (PDMS), and SiO₂ in one step. Such a coating can efficiently eradicate pathogenic Gram-negative bacteria and even multidrug-resistant (MDR) mutants without causing any side-effect such as cytotoxicity, hemolysis, coagulation, and inflammation. We show that immobilized AuDAPT, instead of AuDAPT released from the substrate, is responsible for killing the bacteria and that the antimicrobial components do not enter into the environment to cause secondary contamination to breed drug resistance. Advantages for such coating include applicability on a broad range of surfaces, low cost, stability, high antibacterial efficiency, good biocompatibility, and low risk in antibiotics pollution; these advantages may be particularly helpful in preventing infections that involve medical devices.