Development of glycyrrhetinic acid-modified stealth cationic liposomes for gene delivery

Glycyrrhetinic Acid Receptor-Mediated Zeolitic Imidazolate Framework-8 Loaded Doxorubicin as a Nanotherapeutic System for Liver Cancer Treatment

In this study, we designed and developed a DOX nanodrug delivery system (PEG-GA@ZIF-8@DOX) using ZIF-8 as the carrier and glycyrrhetinic acid (GA) as the targeting ligand. We confirmed that DOX was loaded and PEG-GA was successfully modified on the surface of the nanoparticles. The in vitro release profile of the system was investigated at pH 5.0 and 7.4. The cellular uptake, in vitro cytotoxicity, and lysosomal escape characteristics were examined using HepG2 cells. We established an H22 tumor-bearing mouse model and evaluated the in vivo antitumor activity. The results showed that the system had a uniform nanomorphology. The drug loading capacity was 11.22 ± 0.87%. In acidic conditions (pH 5.0), the final release rate of DOX was 57.73%, while at pH 7.4, it was 25.12%. GA-mediated targeting facilitated the uptake of DOX by the HepG2 cells. PEG-GA@ZIF-8@DOX could escape from the lysosomes and release the drug in the cytoplasm, thus exerting its antitumor effect. When the in vivo efficacy was analyzed, we found that the tumor inhibition rate of PEG-GA@ZIF-8@DOX was 67.64%; it also alleviated the loss of the body weight of the treated mice. This drug delivery system significantly enhanced the antitumor effect of doxorubicin in vitro and in vivo, while mitigating its toxic side effects.

Self-assembled glycyrrhetinic acid derivatives for functional applications: a review

Glycyrrhetinic acid (GA), a famous natural product, has been attracting more attention recently because of its remarkable biological activity, natural sweetness, and good biocompatibility. In the past few years, a considerable amount of literature has grown up around the theme of GA-based chemical modification to broaden its functional applications. Promising structures including gels, micelles, nanoparticles, liposomes, and so forth have been constantly reported. On the one hand, the assembly mechanisms of various materials based on GA derivatives have been elucidated via modern analytical techniques. On the other hand, their potential application prospects in edible additives, intelligent drug delivery, and other fields have been investigated fully due to availability, biocompatibility, and controllable degradability. Inspired by these findings, a systematic summary and classification of the materials formed by GA derivatives seems necessary and meaningful. This review sums up the new functional applications of GA derivatives for the first time and provides better prospects for their application and development.

Enhanced anti-breast cancer efficacy of co-delivery liposomes of docetaxel and curcumin

The successful treatment of breast cancer is hampered by toxicity to normal cells, impaired drug accumulation at the tumor site, and multidrug resistance. We designed a novel multifunctional liposome, CUR-DTX-L, to co-deliver curcumin (CUR) and the chemotherapeutic drug docetaxel (DTX) for the treatment of breast cancer in order to address multidrug resistance (MDR) and the low efficacy of chemotherapy. The mean particle size, polydispersity index, zeta potential, and encapsulation efficiency of CUR-DTX-L were 208.53 ± 6.82 nm, 0.055 ± 0.001, -23.1 ± 2.1 mV, and 98.32 ± 2.37%, respectively. An in vitro release study and CCK-8 assays showed that CUR-DTX-L has better sustained release effects and antitumor efficacy than free drugs, the antitumor efficacy was verified by MCF-7 tumor-bearing mice, the CUR-DTX-L showed better antitumor efficacy than other groups, and the in vivo pharmacokinetic study indicated that the plasma concentration-time curve, mean residence time, and biological half-life time of CUR-DTX-L were significantly increased compared with free drugs, suggesting that it is a promising drug delivery system for the synergistic treatment of breast cancer.

Glycyrrhetinic acid proliposomes mediated by mannosylated ligand: Preparation, physicochemical characterization, environmental stability and bioactivity evaluation

Glycyrrhetinic acid is a bioactive compound extracted from licorice that exhibits inhibition effect on various cancers. However, its hydrophobicity results in low bioavailability that limits application. We aim to overcome this barrier, the present research was performed to prepare glycyrrhetinic acid proliposomes mediated mannosylated ligand (mannose-diester lauric diacid-cholesterol, MDC) and to evaluate its physicochemical characterizations, environmental stability and bioactivity. In preliminary optimization studies of glycyrrhetinic acid proliposomes mediated MDC (MDC-GA-PL), four optimum operating parameters, cryoprotectant of glucose and mannitol, the mixed cryoprotectant ratio (glucose/mannitol) of 1:1, a cryoprotectant/egg phosphatidylcholine mass ratio of 10/1, and -60 ℃ pre-freezing temperature, were obtained after investigation. Under the optimum lyophilization conditions, MDC-GA-PL was freeze-dried and reconstituted proliposomes were characterized. These proliposomes showed that MDC-GA-PL were well-dispersible spherical particles with an average particle size of 120.80 nm, a polydispersity index about 0.095, a zeta potential of -33.15 mV, encapsulation efficiency of 85.9% and drug loading of 6.38%. In vitro drug release study showed that glycyrrhetinic acid release of MDC-GA-PL conforms to the Higuchi release model. In addition, these proliposomes were stable during six months at 4 ℃. Moreover, acute toxicity assay revealed no substantial safety concern for MDC-GA-PL. Finally, in vitro bioactivity of proliposomes was evaluated. Cytotoxicity effect and apoptosis efficiency of MDC-GA-PL by HepG2 cells was significantly higher than that of glycyrrhetinic acid proliposomes without MDC, demonstrating that MDC has a desirable effect on liver target. Overall, we have reason to believe that MDC-GA-PL would be a promising target delivery to improve therapeutic against hepatic diseases.

The Optimized Delivery of Triterpenes by Liposomal Nanoformulations: Overcoming the Challenges

The last decade has witnessed a sustained increase in the research development of modern-day chemo-therapeutics, especially for those used for high mortality rate pathologies. However, the therapeutic landscape is continuously changing as a result of the currently existing toxic side effects induced by a substantial range of drug classes. One growing research direction driven to mitigate such inconveniences has converged towards the study of natural molecules for their promising therapeutic potential. Triterpenes are one such class of compounds, intensively investigated for their therapeutic versatility. Although the pharmacological effects reported for several representatives of this class has come as a well-deserved encouragement, the pharmacokinetic profile of these molecules has turned out to be an unwelcomed disappointment. Nevertheless, the light at the end of the tunnel arrived with the development of nanotechnology, more specifically, the use of liposomes as drug delivery systems. Liposomes are easily synthesizable phospholipid-based vesicles, with highly tunable surfaces, that have the ability to transport both hydrophilic and lipophilic structures ensuring superior drug bioavailability at the action site as well as an increased selectivity. This study aims to report the results related to the development of different types of liposomes, used as targeted vectors for the delivery of various triterpenes of high pharmacological interest.

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.

Mito-Bomb: Targeting Mitochondria for Cancer Therapy

Cancer has been one of the most common life-threatening diseases for a long time. Traditional cancer therapies such as surgery, chemotherapy (CT), and radiotherapy (RT) have limited effects due to drug resistance, unsatisfactory treatment efficiency, and side effects. In recent years, photodynamic therapy (PDT), photothermal therapy (PTT), and chemodynamic therapy (CDT) have been utilized for cancer treatment owing to their high selectivity, minor resistance, and minimal toxicity. Accumulating evidence has demonstrated that selective delivery of drugs to specific subcellular organelles can significantly enhance the efficiency of cancer therapy. Mitochondria-targeting therapeutic strategies are promising for cancer therapy, which is attributed to the essential role of mitochondria in the regulation of cancer cell apoptosis, metabolism, and more vulnerable to hyperthermia and oxidative damage. Herein, the rational design, functionalization, and applications of diverse mitochondria-targeting units, involving organic phosphine/sulfur salts, quaternary ammonium (QA) salts, peptides, transition-metal complexes, guanidinium or bisguanidinium, as well as mitochondria-targeting cancer therapies including PDT, PTT, CDT, and others are summarized. This review aims to furnish researchers with deep insights and hints in the design and applications of novel mitochondria-targeting agents for cancer therapy.

Preparation of docetaxel-loaded, glycyrrhetinic acid-modified nanoparticles and their liver-targeting and antitumor activity

Liver cancer is one of the most common malignancies worldwide and poses a serious threat to human health. The most important treatment method, liver cancer chemotherapy, is limited due to its high toxicity and poor specificity. Targeted drug delivery systems have emerged as novel therapeutic strategies that deliver precise, substantial drug doses to target sites via targeting vectors and enhance the therapeutic efficacy. In the present study, glycyrrhetinic acid-modified hyaluronic acid (GA-HA) was used as a carrier for the model drug docetaxel (DTX) to prepare DTX-loaded GA-HA nanoparticles (DTX/GA-HA-NPs). The results indicated that the DTX/GA-HA-NPs exhibited high monodispersity (particle dispersity index, 0.209±0.116) and desirable particle size (208.73±5.0 nm) and zeta potential (-27.83±3.14 mV). The drug loading capacity and encapsulation efficiency of the NPs were 12.59±0.68 and 85.38±4.62%, respectively. Furthermore, it was determined that FITC-GA-HA was taken up by cells and distributed in the cytoplasm. DTX and DTX/GA-HA (just the DTX delivered by the nanoparticle) aggregated and altered the structure of cellular microtubules. Compared with DTX alone, DTX/GA-HA-NPs had a stronger inhibitory effect on HepG2 cell proliferation and promoted apoptosis of HepG2 cells. All experimental results indicated that DTX/GA-HA-NPs were successfully prepared and had liver-targeting and antitumor activities in vitro, which provided a foundation for future in vivo studies of the antitumor effects of DTX/GA-HA-NPs.

Nanocarriers-loaded with natural actives as newer therapeutic interventions for treatment of hepatocellular carcinoma

Introduction: Cancer has always been a menace for the society. Hepatocellular carcinoma (HCC) is one of the most lethal and 3rdlargest causes of deaths around the world.Area covered: The emergence of natural actives is considered as the greatest boon for fighting cancer. The natural actives take precedence over the traditional chemotherapeutic drugs in terms of their multi-target, multi-level and coordinated effects in the treatment of HCC. Literature reports have indicated the tremendous potential of bioactive natural products in inhibiting the HCC via molecular drug targeting, augmented bioavailability, and the ability for both passive or active targeting and stimulus-responsive drug release characteristics. This review provides a newer treatment approaches involved in the mechanism of action of different natural actives used for the HCC treatment via different molecular pathways. Besides, the promising advantage of natural bioactive-loaded nanocarriers in HCC treatment has also been also presented in this review. Expert opinion: The remarkable outcomes have been observed with therapeutic efficacy of the nanocarriers of natural actives in the treatment of HCC.Furthermore, it requires a thorough assessment of the safety and efficacy evaluation of the nanocarriers for the delivery of targeted natural active ingredients in HCC.].

Targeted Nanotherapeutics for Respiratory Diseases: Cancer, Fibrosis, and Coronavirus

Systemic delivery of therapeutics for treatment of lung diseases has several limitations including poor organ distribution of delivered payload with relatively low accumulation of active substances in the lungs and severe adverse side effects. In contrast, nanocarrier based therapeutics provide a broad range of opportunities due to their ability to encapsulate substances with different aqueous solubility, transport distinct types of cargo, target therapeutics specifically to the deceased organ, cell, or cellular organelle limiting adverse side effects and increasing the efficacy of therapy. Moreover, many nanotherapeutics can be delivered by inhalation locally to the lungs avoiding systemic circulation. In addition, nanoscale based delivery systems can be multifunctional, simultaneously carrying out several tasks including diagnostics, treatment and suppression of cellular resistance to the treatment. Nanoscale delivery systems improve the clinical efficacy of conventional therapeutics allowing new approaches for the treatment of respiratory diseases which are difficult to treat or possess intrinsic or acquired resistance to treatment. The present review summarizes recent advances in the development of nanocarrier based therapeutics for local and targeted delivery of drugs, nucleic acids and imaging agents for diagnostics and treatment of various diseases such as cancer, cystic fibrosis, and coronavirus.

Enhanced targeted delivery of adenine to hepatocellular carcinoma using glycyrrhetinic acid-functionalized nanoparticles in vivo and in vitro

Hepatocellular carcinoma (HCC), a common malignancy in China and globally, is primarily treated through surgical resection and liver transplantation, with chemotherapy as a significant synergistic option. Adenine (Ade), a nucleobase, exhibits antitumor effects by blocking human hepatic carcinoma cells in S phase and inhibiting tumor cell proliferation. However, its use is limited owing to its low solubility, poor targeting ability, and nephrotoxicity. Therefore, liver-targeting drug delivery systems have attracted considerable attention for the treatment of HCC. In this study, we explored the liver-targeting efficacy and antitumor effect of adenine-loaded glycyrrhetinic acid-modified hyaluronic acid (Ade/GA-HA) nanoparticles in vitro and in vivo. The GA-HA nanoparticles possessed obvious targeting specificity toward liver cancer cells, which was mainly achieved by the specific binding of the GA ligand to the GA receptor that was highly expressed on the liver cell membrane. In vitro and in vivo results showed that Ade/GA-HA nanoparticles could inhibit liver cancer cell proliferation and migration, promote apoptosis, and significantly inhibit the growth of tumor tissues. Altogether, this study is the first to successfully demonstrate that the targeting activity and antitumor effect of Ade against HCC are enhanced by using GA-HA nanoparticles in vitro and in vivo.

Improved efficacy of doxorubicin delivery by a novel dual-ligand-modified liposome in hepatocellular carcinoma

Liposomes have been widely used as drug carriers in both biomedical research and for clinical applications, allowing the stabilisation of therapeutic compounds and overcoming obstacles to cellular and tissue uptake. However, liposomes still have low targeting efficiency, resulting in insufficient killing of tumour cells and unnecessary damage to normal cells. In this study, glycyrrhetinic acid (GA) and peanut agglutinin (PNA) were used as ligands to prepare dual-ligand-modified doxorubicin-loaded liposomes (DOX-GA/PNA-Lips) to enhance the targeting accuracy and efficacy of drug delivery against malignant liver cancer. PNA and GA modification enhanced the binding ability of liposomes to liver cancer cells, leading to excellent tissue and cell targeting of DOX-GA/PNA-Lips. DOX-GA/PNA-Lips showed an effective anti-tumour effect in vivo and in vitro, with its targeted delivery facilitating attenuation of the toxic side effects of DOX. These results demonstrated that dual-ligand-modified liposomes may provide an effective strategy for the treatment of hepatocellular carcinoma.

Dual-Targeting Nanoparticle-Mediated Gene Therapy Strategy for Hepatocellular Carcinoma by Delivering Small Interfering RNA

As a gene therapy strategy, RNA interference (RNAi) offers tremendous tumor therapy potential. However, its therapeutic efficacy is restricted by its inferior ability for targeted delivery and cellular uptake of small interfering RNA (siRNA). This study sought to develop a dual-ligand nanoparticle (NP) system loaded with siRNA to promote targeted delivery and therapeutic efficacy. We synthesized a dual receptor-targeted chitosan nanosystem (GCGA), whose target function was controlled by the ligands of galactose of lactobionic acid (LA) and glycyrrhetinic acid (GA). By loading siPAK1, an siRNA targeting P21-activated kinase 1 (PAK1), a molecular-targeted therapeutic dual-ligand NP (GCGA-siPAK1) was established. We investigated the synergistic effect of these two targeting units in hepatocellular carcinoma (HCC). In particular, GCGA-siPAK1 enhanced the NP targeting ability and promoted siPAK1 cell uptake. Subsequently, dramatic decreases in cell proliferation, invasion, and migration, with an apparent increase in cell apoptosis, were observed in treated cells. Furthermore, this dual-ligand NP gene delivery system demonstrated significant anti-tumor effects in tumor-bearing mice. Finally, we illuminated the molecular mechanism, whereby GCGA-siPAK1 promotes endogenous cell apoptosis through the PAK1/MEK/ERK pathway. Thus, the dual-target property effectively promotes the HCC therapeutic effect and provides a promising gene therapy strategy for clinical applications.

Mitochondria-targeted drug delivery in cancers

Mitochondria are considered one of the most important subcellular organelles for targeting and delivering drugs because mitochondria are the main location for various cellular functions and energy (i.e., ATP) production, and mitochondrial dysfunctions and malfunctions cause diverse diseases such as neurodegenerative disorders, cardiovascular disorders, metabolic disorders, and cancers. In particular, unique mitochondrial characteristics (e.g., negatively polarized membrane potential, alkaline pH, high reactive oxygen species level, high glutathione level, high temperature, and paradoxical mitochondrial dynamics) in pathological cancers have been used as targets, signals, triggers, or driving forces for specific sensing/diagnosing/imaging of characteristic changes in mitochondria, targeted drug delivery on mitochondria, targeted drug delivery/accumulation into mitochondria, or stimuli-triggered drug release in mitochondria. In this review, we describe the distinctive structures, functions, and physiological properties of cancer mitochondria and discuss recent technologies of mitochondria-specific "key characteristic" sensing systems, mitochondria-targeted "drug delivery" systems, and mitochondrial stimuli-specific "drug release" systems as well as their strengths and weaknesses.

Preparation and in vitro and in vivo evaluations of 10-hydroxycamptothecin liposomes modified with stearyl glycyrrhetinate

10-Hydroxycamptothecin (HCPT) liposomes surface modified with stearyl glycyrrhetinate (SG) were prepared by the film dispersion method. Characterization of the liposomes, including drug release in vitro, pharmacokinetics and tissue distribution, was done. HCPT in plasma and tissues was determined by high-performance liquid chromatography (HPLC). Compared with the conventional HCPT-liposomes and commercially available hydroxycamptothecin injection (HCPT Inject), pharmacokinetic parameters indicated that SG-HCPT-liposomes had better bioavailability. Regarding tissue distribution, the concentration of HCPT loaded by SG modified liposomes in the liver was higher than other tissues and the risk to the kidney was lower than HCPT-liposomes and HCPT Inject. These results support the hypothesis that the HCPT-liposomes modified with SG show enhanced liver-targeting through the glycyrrhetinic acid (GA) receptor to be an efficient drug carrier, which may help to improve therapeutic methods for hepatic diseases in the future.

Targeting folate receptor β positive tumor-associated macrophages in lung cancer with a folate-modified liposomal complex

Tumor-associated macrophages (TAMs) facilitate cancer progression by promoting tumor invasion, angiogenesis, metastasis, inflammatory responses, and immunosuppression. Folate receptor β (FRβ) is overexpressed in TAMs. However, the clinical significance of FRβ-positive macrophages in lung cancer remains poorly understood. In this study, we verified that FRβ overexpression in lung cancer TAMs was associated with poor prognosis. We utilized a folate-modified lipoplex comprising a folate-modified liposome (F-PLP) delivering a BIM-S plasmid to target both lung cancer cells and FRβ-positive macrophages in the tumor microenvironment. Transfection of LL/2 cells and MH-S cells with F-PLP/pBIM induced cell apoptosis. Injection of F-PLP/pBIM into LL/2 and A549 lung cancer models significantly depleted FRβ-positive macrophages and reduced tumor growth. Treatment of tumor-bearing mice with F-PLP/pBIM significantly inhibited tumor growth in vivo by inducing tumor cell and macrophage apoptosis, reducing tumor proliferation, and inhibiting tumor angiogenesis. In addition, a preliminary safety evaluation demonstrated a good safety profile of F-PLP/pBIM as a gene therapy administered intravenously. This work describes a novel application of lipoplexes in lung cancer targeted therapy that influences the tumor microenvironment by targeting TAMs.

Lipid-based nanoparticle technologies for liver targeting

Liver diseases such as hepatitis, cirrhosis, and hepatocellular carcinoma are global health problems accounting for approximately 800 million cases and over 2 million deaths per year worldwide. Major drawbacks of standard pharmacological therapies are the inability to deliver a sufficient concentration of a therapeutic agent to the diseased liver, and nonspecific drug delivery leading to undesirable systemic side effects. Additionally, depending on the specific liver disease, drug delivery to a subset of liver cells is required. In recent years, lipid nanoparticles have been developed to passively and actively target drugs to the liver. The success of this approach has been highlighted by the FDA-approval of the first liver-targeting lipid nanoparticle, ONPATTRO, in 2018 and many other promising candidate technologies are expected to follow. This review summarizes recent developments of various lipid-based liver-targeting technologies, namely solid-lipid nanoparticles, liposomes, niosomes and micelles, and discusses the challenges and future perspectives in this field.

Synthesis, toxicity and antitumor activity of cobalt carbonyl complexes targeting hepatocellular carcinoma

Based on our previous research, a series of targeting hepatocellular carcinoma complexes, [R-Glycyrrhetinic acid-CH₂C₂H-[Co₂(CO)₆] (R = H, 1; R = NSAIDs-COOH, 2-4; R = Aromatic acid, 5-7; R = Amino acid, 8-10), were synthesized. The test showed they are slow CO releasers. Using HeLa, A549, HT-29, SMMC7721 and HepG2 cells as models, their activities against tumor cell proliferation were firstly evaluated. The resulting data show all the complexes displayed a good anti-proliferation activity against the HepG2 and SMMC-7721 liver cancer cells, and their IC₅₀ values were in the range of 10.07-66.06 µM; compared with cis-platin (DDP), their activities were comparable or even better under the same condition. Among them, complexes 3, 4, 6 and 9 exhibited higher anti-proliferation activities against HepG2 and SMMC-7721 cell lines than the other cell lines. To confirm further these complexes have selectivity to the liver cells, the uptakes of complexes 3, 4, 6 and 9 by HepG2, HT-29, A549 and SMMC7721 cell lines were studied. The results show the cell uptake rates of the complexes by HepG2 cells and SMMC7721 cells were much greater than by other cells under the same condition. In following tests, the tested complexes displayed higher activities in inhibiting NF-kB, COX-2 and iNOS; and they induced HepG2 cells apoptosis by mitochondrial pathway, which assessed by staining with different fluorescent reagent DAPI, PI, Mito-Tracker Green and DCFH-DA. Meanwhile, the tested complexes up-regulated the expression levels of caspase-3 and Bax, down-regulated the Bcl-2 expression. In addition, they had no effect on zebrafish embryo survival, embryo hatching, embryonic movement, zebrafish malformation and zebrafish movement at below 0.5 µM. This suggests the complexes are potential candidates to be used in clinic for liver cancers.

Development of 11-DGA-3-O-Gal-Modified Cantharidin Liposomes for Treatment of Hepatocellular Carcinoma

Background: Liver cancer is a common malignant tumor worldwide, and its morbidity and mortality increase each year. The disease has a short course and high mortality, making it a serious threat to human health. Purpose: The objective of this study was to create novel liver-targeting nanoliposomes to encapsulate cantharidin (CTD) as a potential treatment for hepatic carcinoma. Methods: 3-Galactosidase-30-stearyl deoxyglycyrrhetinic acid (11-DGA-3-O-Gal)-modified liposomes (11-DGA-3-O-Gal-CTD-lip) for the liver-targeted delivery of CTD were prepared via the film-dispersion method and characterized. In vitro analyses of the effects on cellular cytotoxicity, cell migration, cell cycle, and cell apoptosis were carried out and an in vivo pharmacokinetics study and tissue distribution analysis were performed. Results: Compared with unmodified liposomes (CTD-lip), 11-DGA-3-O-Gal-CTD-lip showed higher cytotoxicity and increased the inhibition of HepG2 cell migration, but they did not increase the apoptotic rate of cells. The inhibition mechanism of 11-DGA-3-O-Gal-CTD-lip on hepatocellular carcinoma was partly through cell cycle arrest at the S phase. Analysis of pharmacokinetic parameters indicated that 11-DGA-3-O-Gal-CTD-lip were eliminated more rapidly than CTD-lip. Regarding tissue distribution, the targeting efficiency of 11-DGA-3-O-Gal-CTD-lip to the liver was (41.15 ± 3.28)%, relative targeting efficiency was (1.53 ± 0.31)%, relative uptake rate was( 1.69 ± 0.37)%, and peak concentration ratio was (2.68 ± 0.12)%. Conclusion: 11-DGA-3-O-Gal-CTD-lip represent a promising nanocarrier for the liver-targeted delivery of antitumor drugs to treat hepatocellular carcinoma.

Effects of cationic adjuvant formulation particle type, fluidity and immunomodulators on delivery and immunogenicity of saRNA

Self-amplifying RNA (saRNA) is well suited as a vaccine platform against chlamydia, as it is relatively affordable and scalable, has been shown to induce immunity against multivalent antigens, and can result in protein expression for up to 60 days. Cationic adjuvant formulations (CAFs) have been previously investigated as an adjuvant for protein subunit vaccines; here we optimize the CAFs for delivery of saRNA in vivo and observe the immunogenicity profile in the context of both cellular and humoral immunity against the major outer membrane protein (MOMP) of Chlamydia trachomatis. We tested both liposomal and emulsion based CAFs with solid and fluid phase lipids, with or without the TLR agonists R848 and 3M-052, for in vitro transfection efficiency and cytotoxicity. We then optimized the RNA/delivery system ratio for in vivo delivery using saRNA coding for firefly luciferase (fLuc) as a reporter protein in vivo. We observed that while the fluid phase liposome formulations showed the highest in vitro transfection efficiency, the fluid and solid phase liposomes had equivalent luciferase expression in vivo. Incorporation of R848 or 3M-052 into the formulation was not observed to affect the delivery efficiency of saRNA either in vitro or in vivo. MOMP-encoding saRNA complexed with CAFs resulted in both MOMP-specific cellular and humoral immunity, and while there was a slight enhancement of IFN-γ⁺ T-cell responses when R848 was incorporated into the formulation, the self-adjuvanting effects of RNA appeared to dominate the immune response. These studies establish that CAFs are efficient delivery vehicles for saRNA both for in vitro transfections and in vivo immunogenicity and generate cellular and humoral responses that are proportionate to protein expression.

Natural products in licorice for the therapy of liver diseases: Progress and future opportunities

Liver diseases related complications represent a significant source of morbidity and mortality worldwide, creating a substantial economic burden. Oxidative stress, excessive inflammation, and dysregulated energy metabolism significantly contributed to liver diseases. Therefore, discovery of novel therapeutic drugs for the treatment of liver diseases are urgently required. Licorice is one of the most commonly used herbal drugs in Traditional Chinese Medicine for the treatment of liver diseases and drug-induced liver injury (DILI). Various bioactive components have been isolated and identified from the licorice, including glycyrrhizin, glycyrrhetinic acid, liquiritigenin, Isoliquiritigenin, licochalcone A, and glycycoumarin. Emerging evidence suggested that these natural products relieved liver diseases and prevented DILI through multi-targeting therapeutic mechanisms, including anti-steatosis, anti-oxidative stress, anti-inflammation, immunoregulation, anti-fibrosis, anti-cancer, and drug-drug interactions. In the current review, we summarized the recent progress in the research of hepatoprotective and toxic effects of different licorice-derived bioactive ingredients and also highlighted the potency of these compounds as promising therapeutic options for the treatment of liver diseases and DILI. We also outlined the networks of underlying molecular signaling pathways. Further pharmacology and toxicology research will contribute to the development of natural products in licorice and their derivatives as medicines with alluring prospect in the clinical application.

Antitumor activities of novel glycyrrhetinic acid-modified curcumin-loaded cationic liposomes in vitro and in H22 tumor-bearing mice

At present, the chemotherapy of advanced inoperable liver cancer is limited with serious side effects. Curcumin possesses multiple cancer preventive activities and low safety concerns. However, its poor solubility and instability in water pose significant pharmacological barriers to its clinical application. In this study, we presented a novel delivery system – the glycyrrhetinic acid modified curcumin-loaded cationic liposomes (GAMCLCL) and investigated its antitumor activities on HepG2 cells in vitro and in H22 tumor-bearing mice. The experimental results demonstrated that GAMCLCL was a cationic liposome and could be Intravenous administration. Compared to free curcumin, GAMCLCL exhibited stronger antitumor activities in vitro and in vivo. The antitumor results of GAMCLCL after intravenous administration were very similar to those after intratumoral administration. The main activities of GAMCLCL and curcumin included inhibition of HepG2 cell proliferation, inhibition of tumor growth, reduction of tumor microvascular density, down-regulation of the expression of VEGF protein, and up-regulation of the expression of Caspases3 protein in H22 tumor tissues. Furthermore, GAMCLCL improved the parameters of WBC, RBC, ALT, CRE, LDH of H22 tumor-bearing mice. Curcumin is a nontoxic natural compound with definite antitumor activities, its antitumor effects can be enhanced by preparation of GAMCLCL.

Curcumin in combination with anti-cancer drugs: A nanomedicine review

A huge surge of research is being conducted on combination therapy with anticancer compounds formulated in the form of nanoparticles (NPs). Numerous advantages like dose minimalization and synergism, reversal of multi drug resistance (MDRs), enhanced efficacy have emerged with nanoencapsulation of chemotherapeutic agents with chemo-sensitizing agent like curcumin. Within last couple of years various nano-sized formulations have been designed and tested both in vitro with cell lines for different types of cancers and in vivo with cancer types and drug resistance models. Despite the combinatorial models being advanced, translation to human trials has not been as smooth as one would have hoped, with as few as twenty ongoing clinical trials with curcumin combination, with less than 1/10th being nano-particulate formulations. Mass production of nano-formulation based on their physico-chemical and pharmacokinetics deficits poses as major hurdle up the ladder. Combination of these nano-sized dosage with poorly bioavailable drugs, unspecific target binding ability and naturally unstable curcumin further complicates the formulation aspects. Emphasis is now therefore being laid on altering natural forms of curcumin and usage of formulations like prodrug or coating of curcumin to overcome stability issues and focus more on enhancing the pharmaceutical and therapeutic ability of the nano-composites. Current studies and futuristic outlook in this direction are discussed in the review, which can serve as the basis for upcoming research which could boost commercial translational of improved nano-sized curcumin combination chemotherapy.

Optimization of the Linker Length of Mannose-Cholesterol Conjugates for Enhanced mRNA Delivery to Dendritic Cells by Liposomes

Liposomes (LPs) as commonly used mRNA delivery systems remain to be rationally designed and optimized to ameliorate the antigen expression of mRNA vaccine in dendritic cells (DCs). In this study, we synthesized mannose-cholesterol conjugates (MP_n-CHs) by click reaction using different PEG units (PEG₁₀₀, PEG₁₀₀₀, and PEG₂₀₀₀) as linker molecules. MP_n-CHs were fully characterized and subsequently used to prepare DC-targeting liposomes (MP_n-LPs) by a thin-film dispersion method. MP_n-LPs loaded with mRNA (MP_n-LPX) were finally prepared by a simple self-assembly method. MP_n-LPX displayed bigger diameter (about 135 nm) and lower zeta potential (about 40 mV) compared to MP_n-LPs. The in vitro transfection experiment on DC2.4 cells demonstrated that the PEG length of mannose derivatives had significant effect on the expression of GFP-encoding mRNA. MP₁₀₀₀-LPX containing MP₁₀₀₀-CH can achieve the highest transfection efficiency (52.09 ± 4.85%), which was significantly superior to the commercial transfection reagent Lipo 3K (11.47 ± 2.31%). The optimal DC-targeting MP₁₀₀₀-LPX showed an average size of 132.93 ± 4.93 nm and zeta potential of 37.93 ± 2.95 mV with nearly spherical shape. Moreover, MP₁₀₀₀-LPX can protect mRNA against degradation in serum with high efficacy. The uptake study indicated that MP₁₀₀₀-LPX enhanced mRNA expression mainly through the over-expressing mannose receptor (CD206) on the surface of DCs. In conclusion, mannose modified LPs might be a potential DC-targeting delivery system for mRNA vaccine after rational design and deserve further study on the in vivo delivery profile and anti-tumor efficacy.

Hepatocellular carcinoma-targeted effect of configurations and groups of glycyrrhetinic acid by evaluation of its derivative-modified liposomes

Background

There are abundant glycyrrhetinic acid (GA) receptors on the cellular membrane of hepatocytes and hepatocellular carcinoma (HCC) cells. The receptor binding effect might be related to the structure of the guiding molecule. GA exists in two stereoisomers with C3-hydroxyl and C11-carbonyl active groups.

Purpose

The objective of this study was to investigate the relationship between the HCC-targeted effect and the configurations and groups of GA.

Methods and results

Different GA derivatives (18β-GA, 18α-GA, 3-acetyl-18β-GA [3-Ace-GA] and 11-deoxy-18β-GA [11-Deo-GA]) were used to investigate the targeting effect of GA’s configurations and groups on HCC cells. The EC₅₀ values of competition to binding sites and the ratio of specific binding in HepG2 cells showed that 18β-GA and 3-Ace-GA demonstrated significant competitive effect with fluorescein isothiocyanate (FITC)-labeled GA. Then, the GA derivatives were distearoyl-phosphatidylethanolamine (DSPE)-PEGylated. 18β-GA-, 18α-GA-, 3-Ace-GA-and 11-Deo-GA-modified liposomes were prepared and characterized by size, zeta potential, encapsulation efficiency, loading capacity, leakage and membrane stability. Evaluation on the cellular location in vitro and tumor targeting in vivo was carried out. Compared to common long-circulation liposome (PEG-Lip), more 18β-GA- and 3-Ace-GA-modified liposomes aggregated around HepG2 cells in vitro in short time and transferred into HCC tumors in vivo for a longer time.

Conclusion

The β-configuration hydrogen atom on C18 position of GA played the most important role on the targeting effect. C11-carbonyl and C3-hydroxy groups of GA have certain and little influence on targeting action to HCC, respectively. In general, GA might be a promising targeting molecule for the research on liver diseases and hepatoma therapy.

A folate receptor-targeted lipoplex delivering interleukin-15 gene for colon cancer immunotherapy

Interleukin-15 has been implicated as a promising cytokine for cancer immunotherapy, while folate receptor α (FRα) has been shown to be a potentially useful target for colon cancer therapy. Herein, we developed F-PLP/pIL15, a FRα-targeted lipoplex loading recombinant interleukin-15 plasmid (pIL15) and studied its antitumor effects in vivo using a CT26 colon cancer mouse model. Compared with control (normal saline) treatment, F-PLP/pIL15 significantly suppressed tumor growth in regard to tumor weight (P < 0.001) and reduced tumor nodule formation (P < 0.001). Moreover, when compared to other lipoplex-treated mice, F-PLP/pIL15-treated mice showed higher levels of IL15 secreted in the serum (P < 0.001) and ascites (P < 0.01). These results suggested that the targeted delivery of IL15 gene might be associated with its in vivo antitumor effects, which include inducing tumor cell apoptosis, inhibiting tumor proliferation and promoting the activation of immune cells such as T cells and natural killer cells. Furthermore, hematoxylin and eosin staining of vital organs following F-PLP/pIL15 treatment showed no detectable toxicity, thus indicating that intraperitoneal administration may be a viable route of delivery. Overall, these results suggest that F-PLP/pIL15 may serve as a potential targeting preparation for colon cancer therapy.

Glycyrrhetinic Acid Functionalized Graphene Oxide for Mitochondria Targeting and Cancer Treatment In Vivo

Mitochondria-mediated apoptosis (MMA) is a preferential option for cancer therapy due to the presence of cell-suicide factors in mitochondria, however, low permeability of mitochondria is a bottleneck for targeting drug delivery. In this paper, glycyrrhetinic acid (GA), a natural product from Glycyrrhiza glabra, is found to be a novel mitochondria targeting ligand, which can improve mitochondrial permeability and enhance the drug uptake of mitochondria. GA-functionalized graphene oxide (GO) is prepared and used as an effective carrier for targeted delivery of doxorubicin into mitochondria. The detailed in vitro and in vivo mechanism study shows that GA-functionalized GO causes a decrease in mitochondrial membrane potential and activates the MMA pathway. The GA-functionalized drug delivery system demonstrates highly improved apoptosis induction ability and anticancer efficacy compared to the non-GA-functionalized nanocarrier delivery system. The GA-functionalized nanocarrier also shows low toxicity, suggesting that it can be a useful tool for drug delivery.

Glycyrrhetinic acid as a hepatocyte targeting unit for an anticancer drug delivery system with enhanced cell type selectivity

Herein, we explore glycyrrhetinic acid (GA) as an active targeting ligand for hepatocellular carcinoma (HCC) using a small molecule approach.

Mannosylated liposomes improve therapeutic effects of paclitaxel in colon cancer models

Mannose receptor (MR) is a highly effective endocytic receptor. It is closely related to tumour immune escape and metastasis. We found that MR was highly expressed in some colon cancer cell lines such as CT26 and HCT116 cells. Therefore, MR might be a potential target in colon cancer therapy. In this study, we aimed to develop mannosylated liposomes containing anticancer drug paclitaxel and investigate the potential effects on targeted therapy for colon cancer. Mannosylated liposomes were prepared by film dispersion method. Characterisation, drug release behaviour, cytotoxicity, cellular uptake, anti-tumour efficacy and safety profiles of liposomes were investigated. The results showed that mannosylated liposomes had a higher CT26 cells uptake efficiency and tumour inhibition rate, which might be due to the target effect to MR. And no notable toxicity was observed. Taken together, these data demonstrated that mannosylated liposomes could target colon cancer and improve the efficacy of chemotherapy.

Cellular uptake mechanism and clearance kinetics of fluorescence-labeled glycyrrhetinic acid and glycyrrhetinic acid-modified liposome in hepatocellular carcinoma cells

Glycyrrhetinic acid (GA) is a natural pentacyclic triterpene derivative that exerts significant effects in the suppression of liver cancer. The receptors of GA on liver cells and hepatocellular carcinoma (HCC) cells have drawn broad attention. The effects of GA might depend on its transport into and out of cells. However, the question has not been previously addressed despite its obvious and fundamental importance. In this paper, GA and GA-modified liposome (GA-Lip) were labeled with fluorescein isothiocyanate (FITC) or coumarin 6 (Cou6) using chemical or pharmaceutical techniques. The transport courses of FITC-GA and GA-Cou6-Lip were studied in HepG2 cells in vitro. We found that the fluorescence labeled GA and GA-Lip uptake and clearance were time-dependent. FITC-GA uptake involved passive diffusion and active transport, and the receptors were in the cytomembrane proteins. GA-Cou6-Lip uptake was mediated by caveolae-dependent endocytosis. In addition, FITC-GA and GA-Cou6-Lip clearance of the HCC cells fitted exponential decay and second-order processes, respectively. These findings provide new insights into the anti-HCC actions of GA.

Glycyrrhetinic acid-functionalized mesoporous silica nanoparticles as hepatocellular carcinoma-targeted drug carrier

In this study, a glycyrrhetinic acid-functionalized mesoporous silica nanoparticle (MSN-GA) was prepared for active tumor targeting. MSN-GA exhibited satisfactory loading capacity for insoluble drugs, uniform size distribution, and specific tumor cell targeting. Glycyrrhetinic acid, a hepatocellular carcinoma-targeting group, was covalently decorated on the surface of MSN via an amido bond. The successful synthesis of MSN-GA was validated by the results of Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), and zeta potential measurement. TEM images revealed the spherical morphology and uniform size distribution of the naked MSN and MSN-GA. Curcumin (CUR), an insoluble model drug, was loaded into MSN-GA (denoted as MSN-GA-CUR) with a high-loading capacity (8.78%±1.24%). The results of the in vitro cellular experiment demonstrated that MSN-GA-CUR significantly enhanced cytotoxicity and cellular uptake toward hepatocellular carcinoma (HepG2) cells via a specific GA receptor-mediated endocytosis mechanism. The results of this study provide a promising nanoplatform for the targeting of hepatocellular carcinoma.

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.

Optomizing Transfection Efficiency of Cervical Cancer Cells Transfected by Cationic Liposomes LipofectamineTM2000

BACKGROUND

Currently, cationic liposome has become the commonly used vehicles for gene transfection. Furthermore, one of the most significant steps in microRNAs expression studies is transferring microRNAs into cell cultures successfully. In this study we aim to approach the feasibility of transfection of cervical cancer cell lines mediated by liposome and to obtain the optimized transfection condition for cervical cancer cell lines.

MATERIALS AND METHODS

Lipofectamine(TM)2000 as the carrier, miR-101 mimic was transfected into Hela cells and Siha cells. Using green fluorescent protein as reporter gene, to set different groups according to cell seeding density, the amount of miRNA , miRNA and the proportion of Liposomes, Whether to add serum into medium to study their impact on the liposomal transfection efficiency. Finally, MTT assay was used to analyze the relative minimal cell toxicity of liposome reagents.

RESULTS

The seeding density of Hela cell line and Siha are 1.5 x 10(4) (per well of 24 well plates), miRNA amount is 1ul of both, the ratio of miRNA and liposome is 1:0.5 of Hela cell line; 1:0.7 of Siha cell line respectively, after 24 hours we can get the highest transfection efficiency. Compared with serum medium, only Siha cells cultured with serum-free medium obtained higher transfection efficiency before transfection (P<0.01).MTT assay showed that according to the above conditions which has the lowest cytotoxicity.

CONCLUSIONS

The method of Liposome to transfected is a suitable way and it can be an efficient reagent for miRNA delivery for Hela cells and Siha cells in vitro. It may serve as a reference for the further research or application.

Promising Nanocarriers for PEDF Gene Targeting Delivery to Cervical Cancer Cells Mediated by the Over-expressing FRα

Cervical cancer presents extremely low PEDF expression which is associated with tumor progression and poor prognosis. In this study, folate receptor α (FRα)-targeted nano-liposomes (FLP) were designed to enhance the anti-tumor effect by targeting delivery of exogenous PEDF gene to cervical cancer cells. The targeting molecule F-PEG-Chol was firstly synthesized by a novel simpler method. FLP encapsulating PEDF gene (FLP/PEDF) with a typical lipid-membrane structure were prepared by a film dispersion method. The transfection experiment found FLP could effectively transfect human cervical cancer cells (HeLa cells). FLP/PEDF significantly inhibited the growth of HeLa cells and human umbilical vein endothelial cells (HUVEC cells) and suppressed adhension, invasion and migration of HeLa cells in vitro. In the abdominal metastatic tumor model of cervical cancer, FLP/PEDF administered by intraperitoneal injection exhibited a superior anti-tumor effect probably due to the up-regulated PEDF. FLP/PEDF could not only sharply reduce the microvessel density but also dramatically inhibit proliferation and markedly induce apoptosis of tumor cells in vivo. Moreover, the preliminary safety investigation revealed that FLP/PEDF had no obvious toxicity. These results clearly showed that FLP were desired carriers for PEDF gene and FLP/PEDF might represent a potential novel strategy for gene therapy of cervical cancer.

Effective co-delivery of doxorubicin and curcumin using a glycyrrhetinic acid-modified chitosan-cystamine-poly(ε-caprolactone) copolymer micelle for combination cancer chemotherapy

A glycyrrhetinic acid-modified chitosan-cystamine-poly(ε-caprolactone) copolymer (PCL-SS-CTS-GA) micelle was developed for the co-delivery of doxorubicin (DOX) and curcumin (CCM) to hepatoma cells. Glycyrrhetinic acid (GA) was used as a targeting unit to ensure specific delivery. Co-encapsulation of DOX and CCM was facilitated by the incorporation of poly(ε-caprolactone) (PCL) groups. The highest drug loading content was 19.8% and 8.9% (w/w) for DOX and CCM, respectively. The PCL-SS-CTS-GA micelle presented a spherical or ellipsoidal geometry with a mean diameter of approximately 110nm. The surface charge of the micelle changed from negative to positive, when the pH value of the solution decreased from 7.4 to 6.8. Meanwhile, it also exhibited a character of redox-responsive drug release and GA/pH-mediated endocytosis in vitro. In simulated body fluid with 10mM glutathione, the release rate in 12h was 80.6% and 67.2% for DOX and CCM, respectively. The cell uptake of micelles was significantly higher at pH 6.8 than pH 7.4. The combined administration of DOX and CCM was facilitated by PCL-SS-CTS-GA micelle. Results showed that there was strong synergic effect between the two drugs. The PCL-SS-CTS-GA micelle might turn into a promising and effective carrier for improved combination chemotherapy.

Glycyrrhetinic Acid Mediated Drug Delivery Carriers for Hepatocellular Carcinoma Therapy

Glycyrrhetinic acid (GA), the main hydrolysate of glycyrrhizic acid extracted from the root of licorice, has been used in hepatocellular carcinoma (HCC) therapy. Particularly, GA as a ligand in HCC therapy has been widely explored in different drug delivery systems, including liposomes, micelles, and nanoparticles. There is considerable interest worldwide with respect to the development of GA-modified drug delivery systems due to the extensive presence of GA receptors on the surface of hepatocyte. Up until now, much work has been focused on developing GA-modified drug delivery systems which bear good liver- or hepatocyte-targeted efficiency both in vitro and in vivo. Owing to its contribution in overcoming the limitations of low lipophilicity and poor bioavailability as well as its ability to promote receptor-mediated endocytosis, GA-modified drug delivery systems play an important role in enhancing liver-targeting efficacy and thus are focused on the treatment of HCC. Moreover, since GA-modified delivery systems present more favorable pharmacokinetic properties and hepatocyte-targeting effects, they may be a promising formulation for GA in the treatment of HCC. In this review, we will give an overview of GA-modified novel drug delivery systems, paying attention to their efficacy in treating HCC and discussing their mechanism and the treatment effects.

Drug delivery system targeting advanced hepatocellular carcinoma: Current and future

Hepatocellular carcinoma (HCC) has a fairly high morbidity and is notoriously difficult to treat due to long latent period before detection, multidrug resistance and severe drug-related adverse effects from chemotherapy. Targeted drug delivery systems (DDS) that can selectively deliver therapeutic drugs into tumor sites have demonstrated a great potential in cancer treatment, which could be utilized to resolve the limitations of conventional chemotherapy. Numerous preclinical studies of DDS have been published, but targeted DDS for HCC has yet to be made for practical clinical use. Since rational targeted DDS design should take cancer-specific properties into consideration, we have reviewed the biological and physicochemical properties of HCC extensively to provide a comprehensive understanding on HCC, and recent DDS studies on HCC, aiming to find some potential targeted DDSs for HCC treatment and a meaningful platform for further development of HCC treatments.

FROM THE CLINICAL EDITOR

Hepatocellular carcinoma has a high incidence worldwide and is known to be multidrug resistant. Thus, intensive research is being carried out to find better chemotherapeutic agents as well as new drug delivery systems. In this article, the authors reviewed in depth the current challenges facing new drug designs and also outlined novel targeted drug delivery systems (DDS) in the fight against HCC.

Long circulating anionic liposomes for hepatic targeted delivery of cisplatin

Anionic liposomes, composed of acetyl glycyrrhetinic acid-poly(ethylene glycol)-stearate, 5-cholestene-3-beta-ol-3-hemisuccinate and phosphatidylcholine, were developed for hepatic targeted delivery of cisplatin.

A novel glycyrrhetinic acid-modified oxaliplatin liposome for liver-targeting and in vitro/vivo evaluation

In this study, oxaliplatin (OX) liposomes surface-modified with glycyrrhetinic acid (GA) were developed by the film-dispersion method. Their morphology, physical and chemical properties, and in vitro release performance were investigated. The transmission electron microscope (TEM) image showed that most liposomes were spherical particles with similar size and uniform dispersion. Both OX-liposomes and GA-OX-liposomes had an average size of 90 nm. They were negatively charged, with zeta potentials of −20.6 and −21.3 mV, respectively, and the entrapment efficiency values of both were higher than 94%. In vitro data showed that the application of liposomes could prolong the OX release. The relatively high correlation coefficient values obtained from analyzing the amount of drug released versus the square root of time depicted that release followed the Weibull model. No significant changes were observed after the addition of GA to the liposomes. In vivo, the relatively long time to reach the maximum plasma concentration of OX-liposomes suggested a sustained-release profile of liposomes, which was consistent with the results of the in vitro release study. The increased area under the curve and maximum plasma concentration of OX-liposomes and GA-OX-liposomes demonstrated an increased absorption. The drug concentration in tissues indicated that the GA-modified liposomes delivered OX mainly to liver after intravenous administration. In addition, no severe signs, such as appearance of epithelial necrosis or sloughing of epithelial cells, were detected in histology studies.