Galactosylated solid lipid nanoparticles with cucurbitacin B improves the liver targetability

Understanding the regulatory landscape of protein phosphatase 2A (PP2A): Pharmacological modulators and potential therapeutics

Protein phosphatase 2A (PP2A) is a ubiquitously expressed serine/threonine phosphatase with a diverse and integral role in cellular signalling pathways. Consequently, its dysfunction is frequently observed in disease states such as cancer, inflammation and Alzheimer's disease. A growing understanding of both PP2A and its endogenous regulatory proteins has presented numerous targets for therapeutic intervention. This provides important context for the dynamic control and dysregulation of PP2A function in disease states. Understanding the intricate regulation of PP2A signalling in disease has resulted in the development of novel pharmacological agents aimed at restoring cellular homeostasis. Herein we review the structure and function of PP2A together with pharmacological modulators, both endogenous (proteins) and exogenous (small molecules and peptides), with relevance to targeting PP2A as a future pharmacotherapeutic strategy.

Metabolic fate of the natural anticancer agent cucurbitacin B: an LC-MS/MS-enabled profiling of its major phase I and II conjugates in vivo

Cucurbitacin B (CuB) is a natural triterpenoid with diverse pharmacological effects including potent anticancer activity. However, its oral bioavailability is hampered by limited metabolism in vivo. We characterized CuB's in vivo metabolism in rats to uncover bioactive metabolites retaining therapeutic potential, using a robust UHPLC-Q-TOF-MS/MS workflow. This workflow combined molecular networking, fragmentation filtering, and mass defect filtering to identify CuB metabolites in rat urine, plasma, and feces following oral administration. Thirteen metabolites were identified and seven were confirmed. Major phase I transformations involved hydrolysis, reduction, epoxidation, and amination. Phase II conjugation included cysteine, glutathione, glucuronide, and gluconic acid conjugates. Notably, one of the main metabolites formed was the cysteine conjugate CuB-Cys. CuB-Cys maintained similar in vitro antiproliferative activity to CuB on HepG2, MCF-7, and PANC-1 cancer cell lines. However, it demonstrated lower cytotoxicity towards non-cancerous L02 cells, highlighting improved therapeutic selectivity. Mechanistically, CuB-Cys induced greater apoptotic signaling in HepG2 cells than CuB via enhanced caspase activation and disrupted BAX-Bcl-2 balance. This represents the first systematic characterization of CuB's in vivo metabolic pathway. The identification and confirmation of CuB-Cys provide insight for drug development efforts aiming to maintain therapeutic efficacy while reducing toxicity, via metabolite-based approaches. Our findings shed light on strategies for improving CuB's clinical potential.

Enhanced intracellular accumulation and cytotoxicity of bortezomib against liver cancer cells using N-stearyl lactobionamide surface modified solid lipid nanoparticles

Asialoglycoprotein receptors (ASGPRs) are highly expressed on hepatocytes and have been used for liver-targeted delivery and hepatocellular carcinoma (HCC) therapy. However, targeted delivery of bortezomib (BTZ) to HCC has not been reported. In this study, N-stearyl lactobionamide (N-SALB) with galactose (Gal) moiety was synthesized as a targeting agent and its structure was confirmed by FT-IR and NMR analyses. N-SALB surface-modified solid lipid nanoparticles (SLNs) loaded with BTZ (Gal-SLNs/BTZ) were developed to target BTZ delivery into HCC cancer cells. The Gal-SLNs/BTZ had an average particle size of 116.3 nm, polydispersity index (PDI) of 0.210, and zeta potential of -13.8 mV. TEM analysis showed their nanometer-sized spherical morphology. The encapsulation efficiency (EE) and drug loading (DL) capacity were 84.5 % and 1.16 %, respectively. Release studies showed that BTZ loaded inside the SLNs was slowly released over a period of 72 h at pH 7.4. Flow cytometry analysis showed significantly higher intracellular uptake of N-SALB-targeted nanoparticles than non-targeted nanoparticles in HepG2 cells. All lipid formulations showed good biocompatibility in the cytotoxicity study using MTT assay. Concentration-dependent cytotoxicity was observed for all formulations, with N-SALB-targeted nanoparticles demonstrating more cytotoxicity against HepG2 cells. The highest percentage of apoptosis was obtained for N-SALB-targeted nanoparticles compared to non-targeted nanoparticles (42.2 % and 8.70 %, respectively). Finally, biodistribution studies in HepG2 bearing nude mice showed that the accumulation of targeted nanoparticles in the tumor was significantly higher than non-targeted nanoparticles.

Pharmacokinetics and Biological Activity of Cucurbitacins

Cucurbitacins are a class of secondary metabolites initially isolated from the Cucurbitaceae family. They are important for their analgesic, anti-inflammatory, antimicrobial, antiviral, and anticancer biological actions. This review addresses pharmacokinetic parameters recently reported, including absorption, metabolism, distribution, and elimination phases of cucurbitacins. It includes recent studies of the molecular mechanisms of the biological activity of the most studied cucurbitacins and some derivatives, especially their anticancer capacity, to propose the integration of the pharmacokinetic profiles of cucurbitacins and the possibilities of their use. The main botanical genera and species of American origin that have been studied, and others whose chemo taxonomy makes them essential sources for the extraction of these metabolites, are summarized.

Carbohydrate anchored lipid nanoparticles

Nanotechnology has been a dynamic field for formulation scientists with multidisciplinary research being conducted worldwide. Advancements in development of functional nanosystems have led to evolution of breakthrough technologies. Lipidic nanosystems, in particular, are highly preferred owing to their non-immunogenic safety profiles along with a range of versatile intrinsic properties. Surface modification of lipid nanoparticles by anchoring carbohydrates to these systems is one such attractive drug delivery technology. Carbohydrates confer interesting properties to the nanosystems such as stealth, biostability, bioavailability, reduced toxicity due to decreased immunogenic response, targeting potential as well as ease of commercial availability. The carbohydrate anchored systems can be developed using methods such as adsorption, incorporation (nanoprecipitation or solvent displacement method), crosslinking and grafting. Current review provides a detailed overview of potential lipid based nanoparticulate systems with an emphasis on liposomes, solid lipid nanoparticles, nanostructures lipid carriers and micelles. Review further explores basics of surface modification, methods applied therein, advantages of carbohydrates as surface modifiers, their versatile applications, techniques for characterization of carbohydrate anchored systems and vital regulatory aspects concerned with these specialized systems.

Cliv-92-Loaded Glycyrrhetinic Acid-Modified Chitosan Nanoparticles for Enhanced Hepatoprotection-Preparation, Characterization, and In Vivo Evaluation

Cliv-92 is a mixture of three structurally similar coumarinolignoids and a proven hepatoprotective agent. Low aqueous solubility and poor bioavailability are notable hindrances for its further use. Therefore, glycyrrhetinic acid-linked chitosan nanoparticles loaded with Cliv-92 were prepared for active targeting to the liver. The nanoparticles were prepared by the ionic gelation method to avoid the use of toxic solvents/rigorous agitation. The method of preparation was optimized using a central composite design with independent variables, namely polymer: drug ratio (3:1, w/w), crosslinker concentration (0.5%), and stirring speed (750 rpm). The optimized nanoparticles had a mean particle size of 185.17 nm, a polydispersity index of 0.41, a zeta potential of 30.93 mV, and a drug loading of 16.30%. The prepared formulation showed sustained release of approximately 63% of loaded Cliv-92 over 72 h. The nanoparticles were freeze-dried for long-term storage and further characterized. The formulation was found to be biocompatible for parenteral delivery. In vivo imaging study showed that optimized nanoparticles were preferentially accumulated in the liver and successfully targeting the liver. The present study successfully demonstrated the improved pharmacokinetic properties (≈12% relative bioavailability) and efficacy profile (evidenced by in vivo and histopathological studies) of fabricated Cliv-92 nanoparticles.

Use of cucurbitacins for lung cancer research and therapy

As the main substance in some traditional Chinese medicines, cucurbitacins have been used to treat hepatitis for decades in China. Currently, the use of cucurbitacins against cancer and other diseases has achieved towering popularity among researchers worldwide, as detailed in this review with summarized tables. Numerous studies have reported the potential tumor-killing activities of cucurbitacins in multiple aspects of human malignancies. Continuous research on its anticancer activity mechanisms also brings a glimmer of light to the treatment of patients with lung cancer. In line with the promising roles of cucurbitacins against cancer, through various molecular signaling pathways, it is justifiable to propose the use of cucurbitacins as a potential mainline chemotherapy before the onset and after the diagnosis of lung cancers. Here, this article mainly summarized the findings about the biological functions and underlying mechanisms of cucurbitacins on lung cancer pathogenesis and treatment. In addition, we also discussed the safety and efficacy of their application for further research and even clinical practice.

Phyto-drug conjugated nanomaterials enhance apoptotic activity in cancer

Cancer continues to be one of the leading causes of death worldwide and is a major obstacle to increased life expectancy. However, survival has not improved significantly with average cancer standard treatment strategies over the past few decades; survival rates have remained low, with tumor metastasis, adverse drug reactions, and drug resistance. Therefore, substitute therapies are essential to treat this dreadful disease. Recently, research has shown that natural compounds in plants, such as phytochemicals, are extensively exploited for their anticarcinogenic potential. Phytochemicals may show their anticancer activity different cancer cell markers may alter molecular pathways, which promote in cellular events such as cell cycle arrest and apoptosis, regulate antioxidant status, cell proliferation, migration, invasion and toxicity. Although their outstanding anticancer activity, however, their pharmacological budding is hindered by their low aqueous solubility, poor bioavailability, and poor penetration into cells, hepatic disposition, narrow therapeutic index, and rapid uptake by normal tissues. In this situation, nanotechnology has developed novel inventions to increase the potential use of phytochemicals in anticancer therapy. Nanoparticles can improve the solubility and stability of phytochemicals, specific tumor cell/tissue targeting, enhanced cellular uptake, reduction of phytochemicals. Therapeutic doses of phytochemicals for a long time. Additional benefits include better blood stability, multifunctional design of nanocarriers and improvement in countermeasures. This review summarizes the advances in the use of nanoparticles for the treatment of cancer, as well as various nano-drug deliveries of phytochemicals against cancer. In particular, we are introducing several applications of nanoparticles in combination with phyto-drug for the treatment of cancer.

Hepatic targeting of glycyrrhetinic acid via nanomicelles based on stearic acid-modified fenugreek gum

This study aimed to increase the solubility of glycyrrhetinic acid (GA) in water and enhance its liver-targeting ability using self-assembling nanomicelles (NMs) based on stearic acid-modified fenugreek gum (FG-C₁₈). The GA/FG-C₁₈ NMs were prepared by an ultrasonication dispersion method. The nanomicelles were spherical particles with a particle size of 198.61 ± 1.58 nm and a zeta potential of -30.12 ± 0.28 mV. The drug loading and encapsulation efficiency were 13.34 ± 0.24% and 80.07 ± 1.44%, respectively. The results of differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) indicated that GA was successfully encapsulated into the nanomicelles in a molecularly dispersed state. An in vitro release test showed that GA/FG-C₁₈ NMs possessed a slow drug release profile in PBS (pH 7.4) over 200 h. The cytotoxicity assay indicated that GA/FG-C₁₈ NMs showed much higher inhibitory efficacy in HepG2 cells than in MCF-7 cells. Tissue section studies indicated that the accumulation of DiR-loaded FG-C₁₈ nanomicelles in the liver of mice was higher than that of the DiR solution, and the fluorescence intensity decreased over time. GA/FG-C₁₈ NMs showed a larger area under the curve (AUC) and mean residence time (MRT) compared with free GA after intravenous administration in mice. The in vivo studies showed that GA mainly accumulated in the liver after encapsulation by FG-C₁₈ NMs, and the drug concentration was higher than that of free GA. These results suggested that FG-C₁₈ NMs could serve as a potential drug delivery system for targeting GA to liver tissue.

Zotepine loaded lipid nanoparticles for oral delivery: development, characterization, and in vivo pharmacokinetic studies

Background

The purpose of this work was to prepare and evaluate the zotepine (ZT) loaded solid lipid nanoparticles (SLNs) that might improve the oral bioavailability. ZT is an anti-psychotic drug used for the treatment of schizophrenia. Currently, it is available as parenteral and oral dosage form. But, ZT has a poor oral bioavailability of about 7–13% due to limited aqueous solubility and first-pass effect. ZT-SLNs were developed using homogenization method and characterized for optimal system based on physicochemical characteristics and in vitro release. The optimized ZT-SLNs were evaluated for permeation through rat intestine using evert sac method. The crystalline nature of the ZT-SLNs was studied using DSC and XRD analysis. Surface morphology studies were conducted using SEM. Physical stability of the optimized ZT-SLN was evaluated at refrigerator and room temperature over 2 months. Further, pharmacokinetic (PK) studies of ZT-SLN were conducted in male Wistar rats, in comparison with ZT coarse suspension (ZT-CS), in vivo.

Results

Among all the developed ZT-SLN formulations, optimized formulation (F1) showed Z-avg, PDI, and ZP of 104.3 ± 1.6 nm, 0.17 ± 0.01, and − 30.5 ± 2.5 mV, respectively. In vitro release and permeation studies exhibited 82.9 ± 1.6% of drug release and 19.6 ± 2.1% of percentage drug permeation over 48 h and 120 min, respectively. DSC and XRD studies revealed the conversion of ZT to amorphous form. SEM studies showed spherical shape with improved PDI of ZT-SLN formulation. PK studies showed a significant (p < 0.05) improvement in AUC of about 1.3-fold, in comparison with ZT-CS in Wistar rats.

Conclusion

Therefore, the results concluded that SLNs could be considered as a new alternative delivery system for the enhancement of oral bioavailability of ZT.

Viramidine-Loaded Galactosylated Nanoparticles Induce Hepatic Cancer Cell Apoptosis and Inhibit Angiogenesis

Current estimates indicate that hepatocarcinoma is the leading cause of death globally. There is interest in utilizing nanomedicine for cancer therapy to overcome side effects of chemo-interventions. Ribavirin, an antiviral nucleoside inhibitor, accumulates inside red blood cells, causing anemia. Its analog, viramidine, can concentrate within hepatocytes and spare red blood cells, thus limiting anemia. Hepatocarcinoma cells have a large number of asialoglycoprotein receptors on their membranes that can bind galactosyl-terminating solid lipid nanoparticles (Gal-SLN) and internalize them. Here, viramidine, 5-fluorouracil, and paclitaxel-loaded Gal-SLN were characterized inside cells. Cytotoxicities of free-drug, nano-void, and drug-loaded Gal-SLN were evaluated using HepG2 cells; over 3 days, cell viability was measured. To test the mechanistic pathway, we investigated in vitro apoptosis using flow cytometry and in ovo angiogenesis using the CAM assay. Results showed that 1 and 2 μM of the viramidine-encapsulated Gal-SLN had the highest cytotoxic effect, achieving 80% cell death with a steady increase over 3 days, with induction of apoptosis and reduction of necrosis and angiogenesis, compared to free-drugs. Gal-SLN application on breast cancer MCF-7 cells confirmed its specificity against liver cancer HepG2 cells. We conclude that viramidine-encapsulated Gal-SLN has anticancer and anti-angiogenic activities against hepatocarcinoma.

SPIO-loaded nanostructured lipid carriers as liver-targeted molecular T2-weighted MRI contrast agent

Background

Superparamagnetic iron oxide (SPIO) acts as a negative contrast agent in magnetic resonance imaging (MRI), and is widely used in clinical applications, including the diagnosis of hepatic diseases. Hepatocyte-targeted magnetic resonance contrast agents (MRCAs) can provide useful information for evaluating hepatic diseases. We prepared targeted magnetic nanostructured lipid carriers (MNLCs) to enhance the hepatocytes targeting efficiency.

Methods

In vitro characterizations of MNLCs were determined by transmission electron microscopy (TEM). The cytotoxicity assay of the MNLCs was measured by methyl tetrazolium (MTT) method. The uptaken study was measured by confocal microscopy, flow cytometry and MRI in vitro. The enhanced liver-targeting efficiency of MNLCs was measured by fluorescence imaging and MRI in vivo.

Results

Gal-NLC-SPIO was prepared successfully. The cytotoxicity assay of the MNLCs demonstrated that the MNLC had relatively low cytotoxicity and high biocompatibility for LO2 cells. More importantly, we confirmed that Gal-NLC-SPIO had greater uptake by LO2 cells than Gal-NLC-SPIO/PEG and free Gal in vitro. A liver distribution study of MNLCs in normal mice demonstrated that the fluorescent signal values to livers of the Gal-NLC-SPIO were significantly stronger than those of NLC-SPIO and Gal-NLC-SPIO/PEG. The liver targeting efficiency of Gal-NLC-SPIO was confirmed both in vitro and in vivo.

Conclusions

We successfully developed liver-targeting MNLCs, which showed accurate hepatocytes targeting, and thus have the potential to be a new MRI contrast agent to help the diagnosis of liver diseases.

Cucurbitacin B and cancer intervention: Chemistry, biology and mechanisms (Review)

Cancer is one of the most important healthcare matters, with the worst prognosis but the best possibilities for scientific development. It is likely to increase in the future and cause global havoc designating it as an epidemic. Cancer development requires urgent intervention. Past few decades have witnessed extensive research to challenge carcinogenesis. Treatment involving synthetic discipline is often associated with severe adverse effects, or even worsened prognosis. Accordingly, newer economic and patient friendly molecules are warranted. Many natural substances have proved their potential so far. Cucurbitacin B against cancer and other diseases has achieved towering popularity among the researchers around the world, as detailed in the below sections with summarized tables. In line with the fascinating role of cucurbitacin B against various types of cancers, through various molecular signaling pathways, it is justifiable to propose cucurbitacin B as a mainline chemotherapy before the onset and after the diagnosis of cancer.

Clinical Advancements in the Targeted Therapies against Liver Fibrosis

Hepatic fibrosis, characterized by excessive accumulation of extracellular matrix (ECM) proteins leading to liver dysfunction, is a growing cause of mortality worldwide. Hepatocellular damage owing to liver injury leads to the release of profibrotic factors from infiltrating inflammatory cells that results in the activation of hepatic stellate cells (HSCs). Upon activation, HSCs undergo characteristic morphological and functional changes and are transformed into proliferative and contractile ECM-producing myofibroblasts. Over recent years, a number of therapeutic strategies have been developed to inhibit hepatocyte apoptosis, inflammatory responses, and HSCs proliferation and activation. Preclinical studies have yielded numerous targets for the development of antifibrotic therapies, some of which have entered clinical trials and showed improved therapeutic efficacy and desirable safety profiles. Furthermore, advancements have been made in the development of noninvasive markers and techniques for the accurate disease assessment and therapy responses. Here, we focus on the clinical developments attained in the field of targeted antifibrotics for the treatment of liver fibrosis, for example, small molecule drugs, antibodies, and targeted drug conjugate. We further briefly highlight different noninvasive diagnostic technologies and will provide an overview about different therapeutic targets, clinical trials, endpoints, and translational efforts that have been made to halt or reverse the progression of liver fibrosis.

Improve bile duct-targeted drug delivery and therapeutic efficacy for cholangiocarcinoma by cucurbitacin B loaded phospholipid complex modified with berberine hydrochloride

In present study, a novel phospholipid complex loaded cucurbitacin B modified with berberine hydrochloride (CUB-PLC-BER) was prepared by a simple solvent evaporation method with the aim of improving bile duct-targeted drug delivery and therapeutic efficacy for cholangiocarcinoma (CC). The complex's physicochemical properties were systemically investigated in terms of scanning electron microscopy (SEM), x-ray diffraction (XRD) and infrared absorption spectroscopy (IR). In vivo and in vitro antitumor studies, CUB-PLC-BER and the unmodified cucurbitacin B-phospholipid complex (CUB-PLC) presented stronger antitumor efficacy against human cholangiocarcinoma cells (QBC939 cells) than free cucurbitacin B (CUB), while phospholipids (PL) itself had no significant toxicity. Besides that, CUB-PLC showed the advantage over the free CUB and CUB-PLC-BER with regard to the inhibition of tumor growth in vivo antitumor study. Failure to establish the orthotopic CC model, the study attempted to measure the level of CUB in plasma and in bile to explore bile duct-targeted effect indirectly. In the pharmacokinetics study in rats, the average values of Cmax and AUC0-8h of CUB-PLC-BER group in rat bile were higher than those of CUB-PLC, while an opposite result was found in plasma. Meanwhile, the Cmax, AUC0-8h and AUC0-24h of CUB were the least both in plasma and in bile. The results indicated that the CUB-PLC-BER tended to provide a high and prolonged drug concentration to bile duct, and PL played a central role in internalizing CUB into cells to improve the water insoluble drug's permeability, which was of great benefit to enhance the bioavailability of CUB and improve therapeutic efficacy of CC. These results elucidated the potential of CUB-PLC-BER as drug delivery system for improving bile duct-targeted and therapeutic efficacy for CC.

Diagnostic imaging and therapeutic application of nanoparticles targeting the liver

Liver diseases, particularly viral hepatitis, cirrhosis and hepatocellular carcinoma, are common in clinical practice with high morbidity and mortality worldwide. Many substances for diagnostic imaging and therapy of liver diseases may have either severe adverse effects or insufficient effectiveness in vivo because of their nonspecific uptake. Therefore, by targeting the delivery of drugs into the liver or specific liver cells, drug efficiency may be largely improved. This review summarizes the up-to-date research progress focusing on nanoparticles targeting the liver for both diagnostic and therapeutic purposes. Targeting strategies, mechanisms of enhanced effects, and clinical applications of nanoparticles are discussed specifically. We believe that new targeting nanotechnology such as nanoprobes for multi-modality imaging and multifunctional nanoparticles would facilitate significant advancements in this active research area in the near future.

Magnetoliposomes and their potential in the intelligent drug-delivery field

Research advancements for magnetically guided drug delivery encompass not only the improvement of the design, synthesis and evaluation of more selective nanomaterials bearing magnetic properties, but also the optimization of the transport and delivery of magnetic agents. Such versatile platforms can be utilized for simultaneously carrying therapeutics and diagnostics.

Galactosylated nanostructured lipid carriers for delivery of 5-FU to hepatocellular carcinoma

The aim of the present study was to design a targeted delivery system of 5-fluorouracil (5-FU) for hepatocellular carcinoma (HCC). Lactobionic acid (LB) was conjugated to stearyl amine (SA) by a chemical reaction. The nanostructured lipid carriers (NLCs), containing LB conjugate, lecithin, glyceryl monostearate, oil [oleic acid (OA) or Labrafac 5 or 10%], and 5-FU, were dissolved in alcohol/acetone, the oil phase was added to the aqueous phase containing Tween 80 or Solutol(®) HS15 (0.25 or 0.5%), and NLCs were prepared by an emulsification-solvent diffusion method. Physical properties and drug release were studied in NLCs. The thiazolyl blue tetrazolium bromide assay was used to study the cytotoxicity of NLCs on HepG(2) cells, and the cellular uptake of NLCs was determined by flow cytometry. Fourier transform infrared spectroscopy and (1)H-NMR spectra confirmed the successful conjugation of LB and SA. The optimized NLCs consisted of 0.5% Solutol HS15 and 10% OA oil. The particle size of these nanoparticles was 139.2 nm, with a zeta potential of -18 mV, loading efficiency of 34.2%, release efficiency after 2 hours of the release test was 72.6%, and crystallinity was 0.63%. The galactosylated NLCs of 5-FU were cytotoxic on the HepG(2) cell line in a half concentration of 5-FU and seems promising in reducing 5-FU dose in HCC.