Novel galactosylated biodegradable nanoparticles for hepatocyte-delivery of oridonin

BioMOF-Based Anti-Cancer Drug Delivery Systems

A variety of nanomaterials have been developed specifically for biomedical applications, such as drug delivery in cancer treatment. These materials involve both synthetic and natural nanoparticles and nanofibers of varying dimensions. The efficacy of a drug delivery system (DDS) depends on its biocompatibility, intrinsic high surface area, high interconnected porosity, and chemical functionality. Recent advances in metal-organic framework (MOF) nanostructures have led to the achievement of these desirable features. MOFs consist of metal ions and organic linkers that are assembled in different geometries and can be produced in 0, 1, 2, or 3 dimensions. The defining features of MOFs are their outstanding surface area, interconnected porosity, and variable chemical functionality, which enable an endless range of modalities for loading drugs into their hierarchical structures. MOFs, coupled with biocompatibility requisites, are now regarded as highly successful DDSs for the treatment of diverse diseases. This review aims to present the development and applications of DDSs based on chemically-functionalized MOF nanostructures in the context of cancer treatment. A concise overview of the structure, synthesis, and mode of action of MOF-DDS is provided.

Apocynin-loaded PLGA nanomedicine tailored with galactosylated chitosan intrigue asialoglycoprotein receptor in hepatic carcinoma: Prospective targeted therapy

Nature serves as a priceless source for phytomedicines to treat different types of cancer, including hepatocellular carcinoma (HCC). Apocynin (APO), an anti-cancer phytomedicine, is a particular nicotinamide adenine dinucleotide phosphate-oxidase (NADPH-oxidase) inhibitor, which has recently dawned for its multilateral pharmacological activities. As far as we are aware, no investigation has been carried out yet to develop a targeted-nanostructured delivery system of APO to HCC. Consequently, chitosan derivative with galactose groups namely; galactosylated chitosan (GC), particularly recognized by the asialoglycoprotein receptor (ASGR), was synthesized and its chemical structure was thoroughly characterized by substantial techniques. Afterwards, GC-coated nanoplatform for hepatocyte attachment "APO-loaded galactosylated chitosan-coated poly(d,l-lactide-co-glycolide) nanoparticles (APO-loaded GC-coated PLGA NPs)" was developed. The prosperous APO-loaded GC-coated PLGA NPs would be comprehensively appraised through extensive investigations. Their solid state characterization using Fourier transform-infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry proved APO's encapsulation in the polymeric matrix. Transmission electron microscopy imaging of the investigated NPs highlighted their spherical architecture with a nanosized range and a characteristic halo-like appearance traceable to the GC coating of the NPs' surface. Saliently, the results of in vitro cytotoxicity screening revealed the spectacular anti-cancer efficacy of APO-loaded GC-coated PLGA NPs formula against the HepG2 cell line. Moreover, the fluorescence microscope disclosed the distinguished cellular uptake of such formula via ASGPR mediated endocytosis. Inclusively, a multifunctional nano-phytomedicine delivery system with a promising active hepatocyte-targeting, effective uptake into HepG2 cells, and sustained drug release pattern was successfully developed.

A holistic QBD approach to design galactose conjugated PLGA polymer and nanoparticles to catch macrophages during intestinal inflammation

Recruited macrophages in inflammation attract various ligand-receptor drug delivery approaches. Galactose bound nanocarriers are promising to catch macrophages because of surface-expressed macrophage galactose type-lectin-C (MGL-2) receptor. The present study reported fabrication of galactose conjugated PLGA (GAL-PLGA) polymer and nanoparticles under quality by design (QBD) approach to investigate macrophages targeting potential at inflamed intestine. GAL-PLGA nanoparticles were fabricated through O/W emulsion-evaporation method under QBD approach and Box-Behnken design. Obtained GAL-PLGA nanoparticles have optimum particle size (~118 nm), drug entrapment (87%) and zeta potential (-9.5). TGA, XPRD and FTIR confirmed stability and negate drug-polymer interactions. Further, nanoparticles have considerable hemocompatibility, biocompatibility and cellular uptake; macrophage uptake was inhibited by D-galactose confirming involvement of MGL-2. Moreover, drug retention studies in the DSS-colitis model provide background for potential of nanoparticles to target and reside inflamed intestine. It is concluded that GAL-PLGA nanoparticles are suitable platform to target macrophages at the inflamed intestine through oral route.

Synthesis, Colloidal Characterization and Targetability of Phenylboronic Acid Functionalized α-Tocopheryl Polyethylene Glycol Succinate in Cancer Cells

This study reports targetable micelles developed after covalent functionalization of α-tocopheryl polyethylene glycol succinate (TPGS) with amino phenylboronic acid (APBA). Nuclear magnetic resonance (NMR) and infrared (IR) spectroscopic results showed successful attachment of APBA to the hydrophilic segment of TPGS. Dynamic light scattering and small-angle neutron scattering studies revealed that the conjugate self-assembled in water to produce spherical core-shell micelles (14–20 nm) which remained stable against temperature (ca. 25–45 °C) and pH changes. The micelles could solubilize a high payload of paclitaxel (PLX) without exhibiting changes in the average size. However, at the saturation solubility, drug molecules migrated from the core to the shell region and engaged with APBA groups via π–π stacking interaction. Confocal microscopy and cell sorting analyses verified the effective translocation ability of TPGS-APBA micelles in sialic acid (SA) expressing MDA-MB-453 cells. At equivalent PLX dose, TPGS-APBA micelles showed about a twofold improvement in apoptotic death among the cells exposed for 2 h. Our findings indicate that the attachment of APBA can be a potential strategy for improving the intra-cellular localization of carriers among cancer cells expressing SA residues.

Solubility and Bioavailability Enhancement of Oridonin: A Review

Oridonin (ORI), an ent-kaurene tetracyclic diterpenoid compound, is isolated from Chinese herb Rabdosia rubescens with various biological and pharmacological activities including anti-tumor, anti-microbial and anti-inflammatory effects. However, the clinical application of ORI is limited due to its low solubility and poor bioavailability. In order to overcome these shortcomings, many strategies have been explored such as structural modification, new dosage form, etc. This review provides a detailed discussion on the research progress to increase the solubility and bioavailability of ORI.

Co-Delivery of Docetaxel and Salinomycin to Target Both Breast Cancer Cells and Stem Cells by PLGA/TPGS Nanoparticles

PURPOSE

Conventional chemotherapy is hampered by the presence of breast cancer stem cells (BCSCs). It is crucial to eradicating both the bulky breast cancer cells and BCSCs, using a combination of conventional chemotherapy and anti-CSCs drugs. However, the synergistic ratio of drug combinations cannot be easily maintained in vivo. In our previous studies, we demonstrated that the simultaneous delivery of two drugs via nanoliposomes could maintain the synergistic drug ratio for 12 h in vivo. However, nanoliposomes have the disadvantage of quick drug release, which makes it difficult to maintain the synergistic drug ratio for a long time. Herein, we developed a co-delivery system for docetaxel (DTX)-a first-line chemotherapy drug for breast cancer-and salinomycin (SAL)-an anti-BCSCs drug-in rigid nanoparticles constituted of polylactide-co-glycolide/D-alpha-tocopherol polyethylene glycol 1000 succinate (PLGA/TPGS).

METHODS

Nanoparticles loaded with SAL and DTX at the optimized ratio (NSD) were prepared by the nanoprecipitation method. The characterization, cellular uptake, and cytotoxicity of nanoparticles were investigated in vitro, and the pharmacokinetics, tissue distribution, antitumor and anti-CSCs activity of nanoparticles were evaluated in vivo.

RESULTS

We demonstrated that a SAL/DTX molar ratio of 1:1 was synergistic in MCF-7 cells and MCF-7-MS. Moreover, the enhanced internalization of nanoparticles was observed in MCF-7 cells and MCF-7-MS. Furthermore, the cytotoxicity of NSD against both MCF-7 cells and MCF-7-MS was stronger than the cytotoxicity of any single treatment in vitro. Significantly, NSD could prolong the circulation time and maintain the synergistic ratio of SAL to DTX in vivo for 24 h, thus exhibiting superior tumor targeting and anti-tumor activity compared to other treatments.

CONCLUSION

Co-encapsulation of SAL and DTX in PLGA/TPGS nanoparticles could maintain the synergistic ratio of drugs in vivo in a better manner; thus, providing a promising strategy for synergistic inhibition of breast cancer.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Liver-target nanotechnology facilitates berberine to ameliorate cardio-metabolic diseases

Cardiovascular and metabolic disease (CMD) remains a main cause of premature death worldwide. Berberine (BBR), a lipid-lowering botanic compound with diversified potency against metabolic disorders, is a promising candidate for ameliorating CMD. The liver is the target of BBR so that liver-site accumulation could be important for fulfilling its therapeutic effect. In this study a rational designed micelle (CTA-Mic) consisting of α-tocopheryl hydrophobic core and on-site detachable polyethylene glycol-thiol shell is developed for effective liver deposition of BBR. The bio-distribution analysis proves that the accumulation of BBR in liver is increased by 248.8% assisted by micelles. Up-regulation of a range of energy-related genes is detectable in the HepG2 cells and in vivo. In the high fat diet-fed mice, BBR-CTA-Mic intervention remarkably improves metabolic profiles and reduces the formation of aortic arch plaque. Our results provide proof-of-concept for a liver-targeting strategy to ameliorate CMD using natural medicines facilitated by Nano-technology.

Antifungal efficacy of Itraconazole loaded PLGA-nanoparticles stabilized by vitamin-E TPGS: In vitro and ex vivo studies

Itraconazole (ITZ) loaded Poly-(D, L-lactic-co-glycolic acid, PLGA) nanoparticles (PLGA-NPs) stabilized by D-α-Tocopherol polyethylene-glycol succinate-1000 (TPGS) were developed by nanoprecipitation and single emulsion solvent evaporation methods to improve antifungal activity of ITZ by enhancing its solubility, and hence bioavailability. Encapsulation efficiency, drug loading, in-vitro release, ex-vivo permeation and antifungal activity were performed for the optimized PLGA-NPs. Characterization of PLGA-NPs were performed by scanning electron microscopy, dynamic light scattering, differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffractometry. We observed that nanoprecipitation method was more efficient in encapsulating ITZ by using 0.3% TPGS (stabilizer) than single emulsion solvent evaporation method. Our thermal analysis studies showed no characteristic peaks for crystalline ITZ, indicating drug efficiently encapsulated inside the nanoparticle with no compatibility issues. Drug loaded PLGA-NPs preserved the antifungal activity of ITZ against Candida albicans. Drug release profile from the NPs showed an initial burst release followed by an extended release phase suggesting the potential of NPs for sustained release applications. Furthermore, ITZ encapsulated in PLGA-NPs showed enhanced intestinal permeability in the ex-vivo study. In conclusion, the developed nano-system successfully encapsulated ITZ, yielding an increased permeation and consequential antifungal activity.

Zirconium-Porphyrin PCN-222: pH-responsive Controlled Anticancer Drug Oridonin

Drug delivery carriers with a high drug loading capacity and biocompatibility, especially for controlled drug release, are urgently needed due to the side effects and frequent dose in the traditional therapeutic method. Guided by nanomaterials, we have successfully synthesized zirconium-based metal-organic frameworks, Zr-TCPP (TCPP: tetrakis (4-carboxyphenyl) porphyrin), namely, PCN-222, which is synthesized by solvothermal method. And it has been designed as a drug delivery system (DDS) with a high drug loading of 38.77 wt%. In our work, PCN-222 has achieved pH-sensitive drug release and showed comprehensive SEM, TEM, PXRD, DSC, FTIR, and N2 adsorption-desorption. The low cytotoxicity and good biocompatibility of PCN-222 were certificated by the in vitro results from an MTT assay, DAPI staining, and Annexin V/PI double-staining even cultivated L02 cells and HepG2 cells for 48h. Furthermore, Oridonin, a commonly used cancer chemotherapy drug, is adsorbed into PCN-222 via the solvent diffusion technique. Based on an analysis of the Oridonin release profile, results suggest that it can last for more than 7 days in vitro. And cumulative release rate of Ori at the 7 d was about 86.29% and 63.23% in PBS (pH 5.5 and pH 7.2, respectively) at 37°C. HepG2 cells were chosen to research the cytotoxicity of PCN-222@Ori and free Oridonin. The results demonstrated that the PCN-222@Ori nanocarrier shows higher cytotoxicity in HepG2 cells compared to Oridonin.

Biocompatible Fe-Based Micropore Metal-Organic Frameworks as Sustained-Release Anticancer Drug Carriers

Sustained-release preparation is a hot spot in antitumor drug research, where the first task is to select suitable drug carriers. Research has revealed that carboxylic acid iron metal⁻organic frameworks (MOFs), constructed from iron (Fe) ions and terephthalic acid, are nontoxic and biocompatible. Due to the breathing effect, the skeleton of this mesoporous material is flexible and can reversibly adapt its pore size through drug adsorption. Therefore, we chose one kind of Fe-MOF, MIL-53(Fe), as a carrier for the anticancer drug oridonin (Ori). In this work, we report the design and synthesis of MIL-53(Fe) and explore its ability as a transport vehicle to deliver Ori. MIL-53(Fe) is characterized by scanning electron microscopy and X-ray powder diffraction. A loading capacity of 56.25 wt % was measured by high performance liquid chromatography. This carrier was safe and nontoxic (cell viability > 95.27%), depending on the results of 3-(4,5-dimethylthiazol-2-yl)--2,5-diphenyltetrazolium bromide assays, lactate dehydrogenase assays, and Annexin V-fluoresce isothiocyanate/propidium iodide double-staining assays. After loading the drug, the structure of the MIL-53(Fe) was not destroyed, and Ori was amorphous in MIL-53(Fe). Based on an analysis of the Ori release profile, results suggest that it lasts for more than seven days in vitro. The cumulative release rate of Ori at the seventh day was about 82.23% and 91.75% in phosphate buffer saline solution at 37 °C under pH 7.2 and pH 5.5, respectively. HepG2 cells were chosen to study the cytotoxicity of Ori@MIL-53(Fe), and the results show that the anticancer ratio of Ori@MIL-53(Fe) system reaches 90.62%. Thus, MIL-53 can be used as a carrier for anticancer drugs and Ori@MIL-53(Fe) is a promising sustained-release drug delivery system for the cancer therapy.

Mucosal transfer of wheat germ agglutinin modified lipid-polymer hybrid nanoparticles for oral delivery of oridonin

Wheat germ agglutinin-modified lipid-polymer hybrid nanoparticles (WGA-LPNs) promote cellular uptake after oral delivery via receptor-mediated endocytosis and bioadhesion. Understanding the mucosal transport of WGA-LPNs would help to improve bioavailability and ensure therapeutic efficacy. In this study, WGA-LPNs interacted with mucin, forming larger agglomerates with intact core-shell structure. The interaction of WGA-LPNs with mucin improved enterocyte endocytosis in Caco-2 cells. An in situ intestinal diffusion study in mice confirmed that WGA-LPNs reached enterocytes and underwent endocytosis, despite interference from mucin. Importantly, oral bioavailability of oridonin-loaded WGA-LPNs increased by 1.96-fold compared with that of LPNs. Furthermore, oral administration of WGA-LPNs inhibited tumor growth in HepG2 xenograft nude mice. In addition to elucidating interactions between WGA-LPNs and mucin, these results indicated that WGA-LPNs might act as promising nanocarriers for oral delivery of drugs.

Preparation of a dual cored hepatoma-specific star glycopolymer nanogel via arm-first ATRP approach

A reductase-cleavable and thermo-responsive star-shaped polymer nanogel was prepared via an "arm-first" atom transfer radical polymerization approach. The nanogel consists of a thermo- and redox-sensitive core and a zwitterionic copolymer block. The dual sensitive core is composed of poly(N-isopropylacrylamide) that is formed by disulfide crosslinking of N-isopropylacrylamide. The zwitterionic copolymer block contains a poly(sulfobetaine methacrylate) component, a known anti-adsorptive moiety that extends blood circulation time, and a lactose motif of poly(2-lactobionamidoethyl methacrylamide) that specifically targets the asialoglycoprotein receptors (ASGP-Rs) of hepatoma. Doxorubicin (DOX) was encapsulated into the cross-linked nanogels via solvent extraction/evaporation method and dialysis; average diameter of both blank and DOX-loaded nanogels was ~120 nm. The multi-responsiveness of nanogel drug release in different temperatures and redox conditions was assessed. After 24 h, DOX release was only ~20% at 30°C with 0 mM glutathione (GSH), whereas over 90% DOX release was observed at 40°C and 10 mM GSH, evidence of dual responsiveness to temperature and reductase GSH. The IC50 value of DOX-loaded nanogels was much lower in human hepatoma (HepG2) cells compared to non-hepatic HeLa cells. Remarkably, DOX uptake of HepG2 cells differed substantially in the presence and absence of galactose (0.31 vs 1.42 µg/mL after 48 h of incubation). The difference was non-detectable in HeLa cells (1.21 vs 1.57 µg/mL after 48 h of incubation), indicating that the overexpression of ASGP-Rs leads to the DOX-loaded lactosylated nanogels actively targeting hepatoma. Our data indicate that the lactose-decorated star-shaped nanogels are dual responsive and hepatoma targeted, and could be employed as hepatoma-specific anti-cancer drug delivery vehicle for cancer chemotherapy.

Recent advances in engineered chitosan-based nanogels for biomedical applications

Recent progress in the preparation and biomedical applications of engineered chitosan-based nanogels has been comprehensively reviewed.

A Redox-Sensitive and RAGE-Targeting Nanocarrier for Hepatocellular Carcinoma Therapy

Hepatocellular carcinoma (HCC) is an aggressive malignancy and the second leading cause of cancer death worldwide. Most current therapeutic agents lack the tumor-targeting efficiency and result in a nonselective biodistribution in the body. In our previous study, we identified a peptide Ala-Pro-Asp-Thr-Lys-Thr-Gln (APDTKTQ) that can selectively bind to the receptor of advanced glycation end-products (RAGE), an immunoglobulin superfamily cell surface molecule overexpressed during HCC malignant progression. Here, we report the design of a mixed micelles system modified with this peptide to target HCC cells. Specifically, we modified Pluronic F68 (F68) with APDTKTQ (F68-APDTKTQ), and we conjugated d-α-tocopheryl polyethylene glycol succinate (TPGS) with poly(lactic-co-glycolic acid) (PLGA) by a disulfide linker (TPGS-S-S-PLGA). We mixed TPGS-S-S-PLGA and F68-APDTKTQ (TSP/FP) to form a micelle, followed by the loading of oridonin (ORI). The prepared micelles showed a homogeneously spherical shape without aggregation, triggered an increased cellular uptake, and induced apoptosis in more cells than did the free ORI. Taken together, these results demonstrate the potential of this APDTKTQ-modified ORI-loaded TSP/FP mixed micelle system as a promising strategy for HCC-targeting therapy.