Synthesis, characterization, and in vitro evaluation of curcumin-loaded albumin nanoparticles surface-functionalized with glycyrrhetinic acid

Carboxymethyl starch as a solid dispersion carrier to enhance the dissolution and bioavailability of piperine and 18β-glycyrrhetinic acid

OBJECTIVE

To investigate the applicability of carboxymethyl starch (CMS) as a carrier to prepare solid dispersions (SDs) of piperine (PIP) and 18β-glycyrrhetinic acid (β-GA) (PIP-CMS and β-GA-CMS SDs) and to explore the influence of drug properties on carrier selection.

SIGNIFICANCE

The low oral bioavailability of natural therapeutic molecules, including PIP and β-GA, severely restricts their pharmaceutical applications. Moreover, CMS, a natural polymer, is rarely reported as a carrier for SDs.

METHODS

PIP-CMS and β-GA-CMS SDs were prepared using the solvent evaporation method. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) were used for formulation characterization. Additionally, drug release characteristics were investigated.

RESULTS

In vitro dissolution studies showed that the dissolutions of PIP-CMS and β-GA-CMS SDs were 1.90-2.04 and 1.97-2.22 times higher than pure PIP and β-GA, respectively, at a drug:polymer ratio of 1:6. DSC, XRPD, FT-IR, and SEM analyses confirmed the formation of SDs in their amorphous states. Significant improvements in C_max and AUC_0-24 h of PIP-CMS and β-GA-CMS SDs (17.51 ± 8.15 μg/mL and 210.28 ± 117.13 μg·h/mL, respectively) and (32.17 ± 9.45 μg/mL and 165.36 ± 38.75 μg·h/mL, respectively) were observed in the pharmacokinetic study. Compared with weakly acidic β-GA, loading weakly basic PIP seemed to have a profound effect on stability through intermolecular forces.

CONCLUSIONS

Our findings showed CMS could be a promising carrier for SDs, and loading weakly basic drug may be more suitable, especially in binary SDs system.

A Comprehensive Review on Liver Targeting: Emphasis on Nanotechnology- based Molecular Targets and Receptors Mediated Approaches

BACKGROUND

The pathogenesis of hepatic diseases involves several cells, which complicates the delivery of pharmaceutical agents. Many severe liver diseases affecting the worldwide population cannot be effectively treated. Major hindrances or challenges are natural physiological barriers and non-specific targeting of drugs administered, leading to inefficient treatment. Hence, there is an earnest need to look for novel therapeutic strategies to overcome these hindrances. A kind of literature has reported that drug safety and efficacy are incredibly raised when a drug is incorporated inside or attached to a polymeric material of either hydrophilic or lipophilic nature. This has driven the dynamic investigation for developing novel biodegradable materials, drug delivery carriers, target-specific drug delivery systems, and many other novel approaches.

OBJECTIVE

Present review is devoted to summarizing receptor-based liver cell targeting using different modified novel synthetic drug delivery carriers. It also highlights recent progress in drug targeting to diseased liver mediated by various receptors, including asialoglycoprotein, mannose and galactose receptor, Fc receptor, low-density lipoprotein, glycyrrhetinic, and bile acid receptor. The essential consideration is given to treating liver cancer targeting using nanoparticulate systems, proteins, viral and non-viral vectors, homing peptides and gene delivery.

CONCLUSION

Receptors based targeting approach is one such approach that was explored by researchers to develop novel formulations which can ensure site-specific drug delivery. Several receptors are on the surfaces of liver cells, which are highly overexpressed in various disease conditions. They all are helpful for the treatment of liver cancer.

Glycyrrhizic Acid and Its Hydrolyzed Metabolite 18β-Glycyrrhetinic Acid as Specific Ligands for Targeting Nanosystems in the Treatment of Liver Cancer

Glycyrrhizic acid and its hydrolyzed metabolite 18β-glycyrrhetinic acid, obtained from the plant Glycyrrhiza glabra, have numerous pharmacological activities, such as anti-inflammatory, anti-ulcerative, antiallergic, immunomodulatory, antiviral, antitumor, hepatoprotective, and antioxidant effects, and others. In addition to the pharmacological activities, in the 1980s, an interaction and uptake of these molecules by the liver was verified, which was later confirmed by other studies through the discovery of specific receptors in the hepatocytes. The presence of these specific receptors in the liver led to vectorization and delivery of drugs, by the introduction of glycyrrhizic acid or glycyrrhetinic acid on the surface of nanosystems, for the treatment of liver diseases. This review describes experimental evidence of vectorization by conjugating glycyrrhizic acid or glycyrrhetinic acid to nanosystems and delivery of antitumor drugs for the treatment of liver cancer and also describes the techniques used to perform this conjugation. We have shown that due to the existence of specific receptors for these molecules, in addition to the targeting of nanosystems to hepatocytes, nanosystems having glycyrrhizic acid or glycyrrhetinic acid on their surface had the same therapeutic effect in a significantly lower dose compared to the free drug and unconjugated nanosystems, with consequent reduction of side effects and toxicity.

Albumin Nano-Encapsulation of Piceatannol Enhances Its Anticancer Potential in Colon Cancer Via Downregulation of Nuclear p65 and HIF-1α

Piceatannol (PIC) is known to have anticancer activity, which has been attributed to its ability to block the proliferation of cancer cells via suppression of the NF-kB signaling pathway. However, its effect on hypoxia-inducible factor (HIF) is not well known in cancer. In this study, PIC was loaded into bovine serum albumin (BSA) by desolvation method as PIC–BSA nanoparticles (NPs). These PIC–BSA nanoparticles were assessed for in vitro cytotoxicity, migration, invasion, and colony formation studies and levels of p65 and HIF-1α. Our results indicate that PIC–BSA NPs were more effective in downregulating the expression of nuclear p65 and HIF-1α in colon cancer cells as compared to free PIC. We also observed a significant reduction in inflammation induced by chemical colitis in mice by PIC–BSA NPs. Furthermore, a significant reduction in tumor size and number of colon tumors was also observed in the murine model of colitis-associated colorectal cancer, when treated with PIC–BSA NPs as compared to free PIC. The overall results indicate that PIC, when formulated as PIC–BSA NPs, enhances its therapeutic potential. Our work could prompt further research in using natural anticancer agents as nanoparticels with possible human clinical trails. This could lead to the development of a new line of safe and effective therapeutics for cancer patients.

Dual-Targeted Lactoferrin Shell-Oily Core Nanocapsules for Synergistic Targeted/Herbal Therapy of Hepatocellular Carcinoma

Herein, both strategies of synergistic drug combination together with dual active tumor targeting were combined for effective therapy of hepatocellular carcinoma (HCC). Therefore, based on the tumor sensitizing action, the herbal quercetin (QRC) was co-delivered with the targeted therapeutic drug sorafenib (SFB), preformulated as phospholipid complex, via protein shell-oily core nanocapsules (NCs). Inspired by the targeting action of lactoferrin (LF) via binding to LF receptors overexpressed by HCC cells, LF shell was electrostatically deposited onto the drug-loaded oily core to elaborate LF shell-oily core NCs. For dual tumor targeting, lactobionic acid (LA) or glycyrrhetinic acid (GA) was individually coupled to LF shell for binding to asialoglycoprotein and GA receptors on liver cancer cells, respectively. Compared to LF and GA/LF NCs, the dual-targeted LA/LF-NCs showed higher internalization into HepG2 cells with 2-fold reduction in half-maximal inhibitory concentration compared to free combination therapy after 48 h. Moreover, dual-targeted LF-NCs showed powerful in vivo antitumor efficacy. It was revealed as significant downregulation of the mRNA expression levels of nuclear factor-kappa B and tumor necrosis factor α as well as suppression of Ki-67 protein expression level in diethylnitrosamine (DEN)-induced HCC mice (P < 0.05). Furthermore, dual-targeted LF-NCs attenuated the liver toxicity induced by DEN in animal models. Overall, this study proposes dual-targeted LF-NCs for combined delivery of SFB and QRC as a potential therapeutic HCC strategy.

Albumin nano-encapsulation of caffeic acid phenethyl ester and piceatannol potentiated its ability to modulate HIF and NF-kB pathways and improves therapeutic outcome in experimental colitis

Hypoxia inducible factor and nuclear factor-kappa beta pathways have been proposed as therapeutic targets for several inflammatory diseases. Caffeic acid phenethyl ester (CAPE) and piceatannol (PIC) are natural anti-inflammatory compounds; however, poor bioavailability and limited understanding of biomolecular mechanistic limits its clinical use. The aims of this study are to enhance bioavailability and investigate their impact on nuclear p65 and HIF-1α for the first time in experimental colitis.Dextran sulphate sodium was used to induce colitis in mice and effect of either free CAPE/PIC or CAPE/PIC loaded albumin nanoparticles treatment was observed on disease development and levels of cellular p65 and HIF-1α.Our results indicate that albumin nano-encapsulation of CAPE/PIC not only enhances its anti-inflammatory potential but also potentiates its ability to effectively modulate inflammation related biomolecular pathways. Hence, combining nanotechnology with natural compounds could result in development of new therapeutic options for IBD.

Curcumin-loaded galactosylated BSA nanoparticles as targeted drug delivery carriers inhibit hepatocellular carcinoma cell proliferation and migration

Background

The main objective of this study was to develop novel BSA nanoparticles (BSA NPs) for improving the bioavailability of curcumin as an anticancer drug, and those BSA NPs were galactosylated for forming the curcumin-loaded galactosylated BSA nanoparticles (Gal-BSA-Cur NPs), thus enhancing their ability to target asialoglycoprotein receptor (ASGPR) overexpressed on hepatocellular carcinoma (HCC) cells.

Materials and methods

Gal-BSA-Cur NPs were prepared by the desolvation method and showed a spherical shape and well distribution with the average particle size of 116.24 nm.

Results

In vitro drug release assay exhibited that Gal-BSA-Cur NPs had higher release rates and improved the curcumin solubility. Cell uptake studies confirmed that Gal-BSA-Cur NPs could selectively recognize receptors on the surface of HCC (HepG2) cells and improve internalization ability of drug compared with BSA NPs-loaded curcumin (BSA-Cur NPs), which might be due to high affinity to galactose. Further, the effects of Gal-BSA-Cur NPs were evaluated by cytotoxicity assay, crystal violet assay, cell apoptosis assay, and wound healing assay, respectively, which revealed that Gal-BSA-Cur NPs could inhibit HepG2 cells proliferation, induce cell apoptosis, and inhibit cell migration.

Conclusion

Immunofluorescence staining has proved that the effects of Gal-BSA-Cur NPs related to the suppression of the nuclear factor κB-p65 (NF-κB-p65) expression in HepG2 cell nucleus. Therefore, these results indicate that novel Gal-BSA-Cur NPs are potential candidates for targeted curcumin delivery to HCC cells.

Doxorubicin‑loaded dual‑functional hyaluronic acid nanoparticles: Preparation, characterization and antitumor efficacy in vitro and in vivo

A novel GHH copolymer was synthesized using hyaluronic acid modified with glycyrrhetinic acid and L-histidine (His), and doxorubicin-loaded GHH nanoparticles (DOX/GHH) were prepared for liver-targeted drug delivery and pH-responsive drug release. In the present study, GHH nanoparticles were characterized, and their pH-responsive behaviors were evaluated at different pH levels. The antitumor effect of the DOX/GHH nanoparticles was investigated in vitro and in vivo. Results showed that the DOX/GHH nanoparticles were spherical, and the particle sizes ranged from 238.1 to 156.7 nm with an increase in the degree of substitution of His. The GHH nanoparticles were obviously internalized into human hepatoblastoma cells. In vitro cytotoxicity assay results showed that the DOX/GHH nanoparticles exhibited a dose-dependent antitumor effect. Compared with free DOX, the DOX/GHH nanoparticles displayed higher antitumor efficacy. These results indicate that GHH nanoparticles could be a promising nano-delivery carrier of hydrophobic drugs for liver-targeted therapy.

Folic acid-conjugated mesoporous silica particles as nanocarriers of natural prodrugs for cancer targeting and antioxidant action

Naturally derived prodrugs have a wide range of pharmacological activities, including anticancer, antioxidant, and antiviral effects. However, significant barriers inhibit their use in medicine, e.g. their hydrophobicity. In this comprehensive study, we investigated simple and effective nanoformulations consisting of amine-functionalized and conjugated with folic acid (FA) mesoporous silica nanoparticles (MSNs). Two types of MSNs were studied: KCC- 1, with mean size 324 nm and mean pore diameter 3.4 nm, and MCM - 41, with mean size 197 and pore diameter 2 nm. Both types of MSNs were loaded with three anticancer prodrugs: curcumin, quercetin, and colchicine. The nanoformulations were tested to target in vitro human hepatocellular carcinoma cells (HepG2) and HeLa cancer cells. The amine-functionalized and FA-conjugated curcumin-loaded, especially KCC-1 MSNs penetrated all cells organs and steadily released curcumin. The FA-conjugated MSNs displayed higher cellular uptake, sustained intracellular release, and cytotoxicity effects in comparison to non-conjugated MSNs. The KCC-1 type MSNs carrying curcumin displayed the highest anticancer activity. Apoptosis was induced through specific signaling molecular pathways (caspase-3, H2O2, c-MET, and MCL-1). The nanoformulations displayed also an enhanced antioxidant activity compared to the pure forms of the prodrugs, and the effect depended on the time of release, type of MSN, prodrug, and assay used. FA-conjugated MSNs carrying curcumin and other safe natural prodrugs offer new possibilities for targeted cancer therapy.

Polymeric Nano-Micelles as Novel Cargo-Carriers for LY2157299 Liver Cancer Cells Delivery

LY2157299 (LY), which is very small molecule bringing high cancer diffusion, is a pathway antagonist against TGFβ. LY dosage can be diluted by blood plasma, can be captured by immune system or it might be dissolved during digestion in gastrointestinal tract. The aim of our study is to optimize a “nano-elastic” carrier to avoid acidic pH of gastrointestinal tract, colon alkaline pH, and anti-immune recognition. Polygalacturonic acid (PgA) is not degradable in the gastrointestinal tract due to its insolubility at acidic pH. To avoid PgA solubility in the colon, we have designed its conjugation with Polyacrylic acid (PAA). PgA-PAA conjugation has enhanced their potential use for oral and injected dosage. Following these pre-requisites, novel polymeric nano-micelles derived from PgA-PAA conjugation and loading LY2157299 are developed and characterized. Efficacy, uptake and targeting against a hepatocellular carcinoma cell line (HLF) have also been demonstrated.

Hybrid polymeric-protein nano-carriers (HPPNC) for targeted delivery of TGFβ inhibitors to hepatocellular carcinoma cells

TGFβ1 pathway antagonists have been considered promising therapies to attenuate TGFβ downstream signals in cancer cells. Inhibiting peptides, as P-17 in this study, are bound to either TGFβ1 or its receptors, blocking signal transduction. However, for efficient use of these TGFβ1antagonist as target therapeutic tools, improvement in their delivery is required. Here, a plasmid carrying specific shDNA (SHT-DNA), small interfering RNA (siRNA), and the peptide (P-17) were loaded separately into folic acid (FA)-functionalized nano-carriers made of Bovine Serum Albumin (BSA). The two building blocks of the carrier, (BSA and FA) were used because of the high affinity of albumin for liver and for the overexpression of folate receptors on the membrane of hepatocellular carcinoma cells. The empty and the encapsulated carriers were thoroughly investigated to characterize their structure, to evaluate the colloidal stability and the surface functionalization. The entrapment of SHT-DNA, siRNA and P-17, respectively, was demonstrated by morphological and quantitative analysis. Finally, cellular studies were performed to assess the targeting efficiency of the hybrid carriers. These vectors were used because of the high affinity of albumin for liver and for the overexpression of folate receptors on the membrane hepatocellular carcinoma cells. The empty and the encapsulated carriers were thoroughly investigated to characterize their structure, to evaluate the colloidal stability and the surface functionalization. The entrapment of SHT-DNA, siRNA and P-17, respectively, was demonstrated by morphological and quantitative analysis. A novel fabrication of Hybrid Polymeric-Protein Nano-Carriers (HPPNC) for delivering TGF β1 inhibitors to HCC cells has been developed. SHT-DNA, siRNA and P-17 have been successfully encapsulated. TGF β1 inhibitors-loaded HPPNC were efficiently uptaken by HLF cells.

A Glycyrrhetinic Acid-Modified Curcumin Supramolecular Hydrogel for liver tumor targeting therapy

Curcumin (Cur), a phenolic anti-oxidant compound obtained from Curcuma longa plant, possesses a variety of therapeutic properties. However, it is suffered from its low water solubility and low bioavailability property, which seriously restricts its clinical application. In this study, we developed a glycyrrhetinic acid (GA) modified curcumin supramolecular pro-gelator (GA-Cur) and a control compound Nap-Cur by replacing GA with the naphthylacetic acid (Nap). Both compounds showed good water solubility and could form supramolecular gels by disulfide bond reduction triggered by glutathione (GSH) in vitro. Both formed gels could sustainedly release Cur in buffer solutions. We also investigated the cytotoxicity of pro-gelators to HepG2 cells by a MTT assay and determined the cellular uptake behaviours of them by fluorescence microscopy and LC-MS. Due to the over expression of GA receptor in liver cancer cells, our pro-gelator of GA-Cur showed an enhanced cellular uptake and better inhibition capacity to liver tumor cells than Nap-Cur. Therefore, the GA-Cur could significantly inhibit HepG2 cell growth. Our study provides a novel nanomaterial for liver tumor chemotherapy.

Novel multifunctional pH-sensitive nanoparticles loaded into microbubbles as drug delivery vehicles for enhanced tumor targeting

This study fabricated novel multifunctional pH-sensitive nanoparticles loaded into microbubbles (PNP-MB) with the combined advantages of two excellent drug delivery vehicles, namely, pH-sensitive nanoparticles and microbubbles. As an antitumor drug, resveratrol (RES) was loaded into acetylated β-cyclodextrin nanoparticles (RES-PNP). The drug-loaded nanoparticles were then encapsulated into the internal space of the microbubbles. The characterization and morphology of this vehicle were investigated through dynamic light scattering and confocal laser scanning microscopy, respectively. In vitro drug release was performed to investigate the pH sensitivity of RES-PNP. The antitumor property of RES-loaded PNP-MB (RES-PNP-MB) was also analyzed in vivo to evaluate the antitumor effect of RES-PNP-MB. Results suggested that PNP exhibited pH sensitivity, and was successfully encapsulated into the microbubbles. RES-PNP-MB exhibit effective tumor growth suppressing in vivo. Therefore, such drug delivery vehicle should be of great attention in tumor therapy.