PEG modification on (111)In-labeled phosphatidyl serine liposomes for imaging of atherosclerotic plaques

Recent updates in applications of nanomedicine for the treatment of hepatic fibrosis

Over recent decades, nanomedicine has played an important role in the enhancement of therapeutic outcomes compared to those of conventional therapy. At the same time, nanoparticle drug delivery systems offer a significant reduction in side effects of treatments by lowering the off-target biodistribution of the active pharmaceutical ingredients. Cancer nanomedicine represents the most extensively studied nanotechnology application in the field of pharmaceutics and pharmacology since the first nanodrug for cancer treatment, liposomal doxorubicin (Doxil®), has been approved by the FDA. The advancement of cancer nanomedicine and its enormous technological success also included various other target diseases, including hepatic fibrosis. This confirms the versatility of nanomedicine for improving therapeutic activity. In this review, we summarize recent updates of nanomedicine platforms for improving therapeutic efficacy regarding liver fibrosis. We first emphasize the challenges of conventional drugs for penetrating the biological barriers of the liver. After that, we highlight design principles of nanocarriers for achieving improved drug delivery of antifibrosis drugs through passive and active targeting strategies.

Formulation of Phytosomes Containing Rubia cordifolia Extract for Neuropathic Pain: In Vitro and In Vivo Evaluation

This study aimed to develop a delivery system for the dried aqueous extract of Rubia cordifolia leaves (RCE) that could improve the neuroprotective potential of RCE by improving the bioavailability of the chief chemical constituent rubiadin. Rubiadin, an anthraquinone chemically, is a biomarker phytoconstituent of RCE. Rubiadin is reported to have strong antioxidant and neuroprotective activity but demonstrates poor bioavailability. In order to resolve the problem related to bioavailability, RCE and phospholipids were reacted in disparate ratios of 1:1, 1:2, and 1:3 to prepare phytosome formulations PC1, PC2, and PC3, respectively. The formulation PC2 showed particle size of 289.1 ± 0.21 nm, ζ potential of -6.92 ± 0.10 mV, entrapment efficiency of 72.12%, and in vitro release of rubiadin of 89.42% at pH 7.4 for a period up to 48 h. The oral bioavailability and neuroprotective potential of PC2 and RCE were assessed to evaluate the benefit of PC2 formulation over the crude extract RCE. Formulation PC2 showed a relative bioavailability of 134.14% with a higher neuroprotective potential and significantly (p < 0.05) augmented the nociceptive threshold against neuropathic pain induced by partial sciatic nerve ligation method. Antioxidant enzyme levels and histopathological studies of the sciatic nerves in various treatment groups significantly divulged that PC2 has enough potential to reverse the damaged nerves into a normal state. Finally, it was concluded that encapsulated RCE as a phytosome is a potential carrier system for enhancing the delivery of RCE for the efficient treatment of neuropathic pain.

Preparation and evaluation of 111In-labeled liposomes containing phosphatidylglycerol for detection of macrophages in atherosclerotic plaques

Macrophage infiltration is a characteristic feature of atherosclerotic plaque progression. Since liposomes containing 1,2-distearoyl-sn-glycero-3-phosphoglycerol (DSPG) are efficiently phagocytosed by macrophages, we deduced that radiolabeled liposomes containing DSPG could potentially be used for nuclear imaging of vulnerable atherosclerotic plaques. Indium-111 (111In)-labeled liposomes containing different ratios of DSPG were developed with a high labeling efficiency. 111In-labeled liposomes with higher DSPG content showed higher uptake by macrophage-like RAW264 cells. A biodistribution study demonstrated rapid blood clearance and selective accumulation in the liver and spleen, especially in normal mice injected with 111In-labeled liposomes with higher DSPG content. Accumulation in atherosclerotic plaques was evaluated using 111In-labeled DSPG liposomes, which had the highest DSPG content among the studied liposomes. 111In-labeled DSPG liposomes accumulated in the plaques and the radioactive regions were mostly consistent with the distribution of macrophages. The target-to-non-target ratio of 111In-labeled DSPG liposomes was higher than that of 111In-labeled control liposomes without DSPG. These results suggest that 111In-labeled liposomes containing DSPG are useful for nuclear medical diagnosis of atherosclerotic plaques.

Radiolabeled Liposomes for Nuclear Imaging Probes

Quantitative nuclear imaging techniques are in high demand for various disease diagnostics and cancer theranostics. The non-invasive imaging modality requires radiotracing through the radioactive decay emission of the radionuclide. Current preclinical and clinical radiotracers, so-called nuclear imaging probes, are radioisotope-labeled small molecules. Liposomal radiotracers have been rapidly developing as novel nuclear imaging probes. The physicochemical properties and structural characteristics of liposomes have been elucidated to address their long circulation and stability as radiopharmaceuticals. Various radiolabeling methods for synthesizing radionuclides onto liposomes and synthesis strategies have been summarized to render them biocompatible and enable specific targeting. Through a variety of radionuclide labeling methods, radiolabeled liposomes for use as nuclear imaging probes can be obtained for in vivo biodistribution and specific targeting studies. The advantages of radiolabeled liposomes including their use as potential clinical nuclear imaging probes have been highlighted. This review is a comprehensive overview of all recently published liposomal SPECT and PET imaging probes.

Development and evaluation of Hedyotis corymbosa (L.) extract containing phytosomes: a preclinical approach for treatment of neuropathic pain in rodent model

PURPOSE

The study was aimed to encapsulate Hedyotis corymbosa extract (HCE) into phytosomes to improve its therapeutic efficacy in neuropathic pain by enhancing the bioavailability of chief chemical constituent Hedycoryside -A (HCA).

METHODS

For preparing phytosomes complexes (F1, F2, and F3), HCE and phospholipids were reacted in disparate ratio. F2 was chosen to assess its therapeutic efficacy in neuropathic pain induced by partial sciatic nerve ligation. Nociceptive threshold and oral bioavailability were also estimated for F2.

RESULTS

Particle size, zeta potential and entrapment efficiency for F2 were analysed as 298.1 ± 1.1 nm, -3.92 ± 0.41 mV and 72.12 ± 0.72% respectively. F2 gave enhanced relative bioavailability (158.92%) of HCA along with a greater neuroprotective potential showing a significant antioxidant effect and augmentation (p < 0.05) in nociceptive threshold with the diminution in damage to nerves.

CONCLUSION

F2 is an optimistic formulation for enhancing the HCE delivery for the effective treatment of neuropathic pain.

Antioxidant Response Activating nanoParticles (ARAPas) localize to atherosclerotic plaque and locally activate the Nrf2 pathway

Atherosclerotic disease is the leading cause of death world-wide with few novel therapies available despite the ongoing health burden. Redox dysfunction is a well-established driver of atherosclerotic progression; however, the clinical translation of redox-based therapies is lacking. One of the challenges facing redox-based therapies is their targeted delivery to cellular domains of redox dysregulation. In the current study, we sought to develop Antioxidant Response Activating nanoParticles (ARAPas), encapsulating redox-based interventions, that exploit macrophage biology and the dysfunctional endothelium in order to selectively accumulate in atherosclerotic plaque. We employed flash nanoprecipitation (FNP) to synthesize bio-compatible polymeric nanoparticles encapsulating the hydrophobic Nrf2 activator drug, CDDO-Methyl (CDDOMe-ARAPas). Nuclear factor erythroid 2-related factor 2 (Nrf2)-activators are a promising class of redox-active drug molecules whereby activation of Nrf2 results in the expression of several antioxidant and cyto-protective enzymes that can be athero-protective. In this study, we characterize the physicochemical properties of CDDOMe-ARAPas as well as confirm their in vitro internalization by murine macrophages. Drug release of CDDOMe was determined by Nrf2-driven GFP fluorescence. Moreover, we show that these CDDOMe-ARAPas exert anti-inflammatory effects in classically activated macrophages. Finally, we show that CDDOMe-ARAPas selectively accumulate in atherosclerotic plaque of two widely-used murine models of atherosclerosis: ApoE^-/- and LDLr^-/- mice, and are capable of increasing gene expression of Nrf2-transcriptional targets in the atherosclerotic aortic arch. Future work will assess the therapeutic efficacy of intra-plaque Nrf2 activation with CDDOMe-ARAPas to inhibit atherosclerotic plaque progression. Overall, our present studies underline that targeting of atherosclerotic plaque is an effective means to enhance delivery of redox-based interventions.

Nanomaterials: A Promising Therapeutic Approach for Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a primary cause of death globally. A few classic and hybrid treatments exist to treat CVDs. However, they lack in both safety and effectiveness. Thus, innovative nanomaterials for disease diagnosis and treatment are urgently required. The tiny size of nanomaterials allows them to reach more areas of the heart and arteries, making them ideal for CVDs. Atherosclerosis causes arterial stenosis and reduced blood flow. The most common treatment is medication and surgery to stabilize the disease. Nanotechnologies are crucial in treating vascular disease. Nanomaterials may be able to deliver medications to lesion sites after being infused into the circulation. Newer point‐of‐care devices have also been considered together with nanomaterials. For example, this study will look at the use of nanomaterials in imaging, diagnosing, and treating CVDs.

Development and evaluation of phytosome-loaded microsphere system for delivery of ginseng extract

The current research work focuses mainly on evolving a delivery system for ginseng extract (GE), which in turn will ameliorate the neuroprotective potential through enhancing the Ginsenoside Rb1(GRb1) bioavailability (BA). Phytosome complexes (F1, F2, and F3) were prepared by reacting GE with phospholipids in disparate ratios. F3 was chosen for preparing the phytosomes powder (PP) and phytosomes-loaded microspheres (PMs). Extract microspheres (EMs) were prepared by the addition of extract directly into the same polymer mixture. F3 gave enhanced entrapment efficiency (50.61%, w/w) along with spherical-shaped particle size (42.58 ± 1.4 nm) with the least polydispersity index (0.193 ± 0.01). PM showed an enhanced relative bioavailability (157.94%) of GRb1. It also showed a greater neuroprotective potential exhibiting significant (p < 0.05) augmentation in the nociceptive threshold. It was concluded that the PM system might be an optimistic and feasible strategy to enhance the delivery of GE for the effectual treatment of neuropathy.

Therapeutic Efficacy Evaluation of Pegylated Liposome Encapsulated With Vinorelbine Plus 111In Repeated Treatments in Human Colorectal Carcinoma With Multimodalities of Molecular Imaging

BACKGROUND/AIM

In precision therapy, liposomal encapsulated chemotherapeutic drugs have been developed to treat cancers by achieving higher drug accumulation in the tumor compared to normal tissues/organs.

MATERIALS AND METHODS

We developed a novel chemoradiotherapeutic approach via nanoliposomes conjugated with vinorelbine (VNB) and ¹¹¹In (¹¹¹In-VNB-liposome) and examined their pharmacokinetics, biodistribution, maximum tolerance dose, and toxicity in a NOD/SCID mouse model.

RESULTS

Pharmacokinetic results showed that the area under the curve (AUC) of PEGylated liposomes was about 17-fold higher than that of the free radioisotope. Tumor growth inhibition by ¹¹¹In-VNB-liposome was significantly higher than that of the control (p<0.05).

CONCLUSION

The tumors in NOD/SCID mice bearing HT-29/tk-luc xenografts were significantly suppressed by ¹¹¹In-VNB-liposomes. The study proposed repeated treatments with a novel liposome-mediated radiochemotherapy and validation of therapeutic efficacy via imaging.

Enhanced efficacy of curcumin with phosphatidylserine-decorated nanoparticles in the treatment of hepatic fibrosis

Hepatic macrophages have been considered as a therapeutic target for liver fibrosis treatment, and phosphatidylserine (PS)-containing nanoparticles are commonly used to mimic apoptotic cells that can specifically regulate macrophage functions, resulting in anti-inflammatory effects. This study was designed to test the efficacy of PS-modified nanostructured lipid carriers (mNLCs) containing curcumin (Cur) (Cur-mNLCs) in the treatment of liver fibrosis in a rat model. Carbon tetrachloride-induced liver fibrosis in rats was used as an experimental model, and the severity of the disease was examined by both biochemical and histological methods. Here, we showed that mNLCs were spherical nanoparticles with decreased negative zeta potentials due to PS decoration, and significantly increased both mean residence time and area under the curve of Cur. In the rats with liver fibrosis, PS-modification of NLCs enhanced the nanoparticles targeting to the diseased liver, which was evidenced by their highest accumulation in the liver. As compared to all the controls, Cur-mNLCs were significantly more effective at reducing the liver damage and fibrosis, which were indicated by in Cur-mNLCs-treated rats the least increase in liver enzymes and pro-inflammatory cytokines in the circulation, along with the least increase in collagen fibers and alpha smooth muscle actin and the most increased hepatocyte growth factors (HGF) and matrix metalloprotease (MMP) two in the livers. In conclusion, PS-modified NLCs nanoparticles prolonged the retention time of Cur, and enhanced its bioavailability and delivery efficiency to the livers, resulting in reduced liver fibrosis and up-regulating hepatic expression of HGF and MMP-2.

Radionuclide imaging of liposomal drug delivery

INTRODUCTION

Ever since their discovery, liposomes have been radiolabeled to monitor their fate in vivo. Despite extensive preclinical studies, only a limited number of radiolabeled liposomal formulations have been examined in patients. Since they can play a crucial role in patient management, it is of importance to enable translation of radiolabeled liposomes into the clinic.

AREAS COVERED

Liposomes have demonstrated substantial advantages as drug delivery systems and can be efficiently radiolabeled. Potentially, radiolabeled drug-loaded liposomes form an elegant theranostic system, which can be tracked in vivo using single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. In this review, we discuss important aspects of liposomal research with a focus on the use of radiolabeled liposomes and their potential role in drug delivery and monitoring therapeutic effects.

EXPERT OPINION

Radiolabeled drug-loaded liposomes have been poorly investigated in patients and no radiolabeled liposomes have been approved for use in clinical practice. Evaluation of the risks, pharmacokinetics, pharmacodynamics and toxicity is necessary to meet pharmaceutical and commercial requirements. It remains to be demonstrated whether the results found in animal studies translate to humans before radiolabeled liposomes can be implemented into clinical practice.

Enhancement of Anti-Inflammatory Activity of Curcumin Using Phosphatidylserine-Containing Nanoparticles in Cultured Macrophages

Macrophages are one kind of innate immune cells, and produce a variety of inflammatory cytokines in response to various stimuli, such as oxidized low density lipoprotein found in the pathogenesis of atherosclerosis. In this study, the effect of phosphatidylserine on anti-inflammatory activity of curcumin-loaded nanostructured lipid carriers was investigated using macrophage cultures. Different amounts of phosphatidylserine were used in the preparation of curcumin nanoparticles, their physicochemical properties and biocompatibilities were then compared. Cellular uptake of the nanoparticles was investigated using a confocal laser scanning microscope and flow cytometry analysis in order to determine the optimal phosphatidylserine concentration. In vitro anti-inflammatory activities were evaluated in macrophages to test whether curcumin and phosphatidylserine have interactive effects on macrophage lipid uptake behavior and anti-inflammatory responses. Here, we showed that macrophage uptake of phosphatidylserine-containing nanostructured lipid carriers increased with increasing amount of phosphatidylserine in the range of 0%–8%, and decreased when the phosphatidylserine molar ratio reached over 12%. curcumin-loaded nanostructured lipid carriers significantly inhibited lipid accumulation and pro-inflammatory factor production in cultured macrophages, and evidently promoted release of anti-inflammatory cytokines, when compared with curcumin or phosphatidylserine alone. These results suggest that the delivery system using PS-based nanoparticles has great potential for efficient delivery of drugs such as curcumin, specifically targeting macrophages and modulation of their anti-inflammatory functions.