Hydrotropic polymeric mixed micelles based on functional hyperbranched polyglycerol copolymers as hepatoma-targeting drug delivery system

Role of non-coding RNAs in modulating the response of cancer cells to paclitaxel treatment

Paclitaxel is a chemotherapeutic substance that is administered for treatment of an extensive spectrum of human malignancies. In spite of its potent short-term effects against tumor cells, resistance to paclitaxel occurs in a number of patients precluding its long-term application in these patients. Non-coding RNAs have been shown to influence response of cancer cells to this chemotherapeutic agent via different mechanisms. Mechanistically, these transcripts regulate expression of several genes particularly those being involved in the apoptotic processes. Lots of in vivo and in vitro assays have demonstrated the efficacy of oligonucleotide-mediated microRNAs (miRNA)/ long non-coding RNAs (lncRNA) silencing in enhancement of response of cancer cells to paclitaxel. Therefore, targeted therapies against non-coding RNAs have been suggested as applicable modalities for combatting resistance to this agent. In the present review, we provide a summary of studies which assessed the role of miRNAs and lncRNAs in conferring resistance to paclitaxel.

Superbranched polyglycerol nanostructures as drug delivery and theranostics tools for cancer treatment

Hyperbranched polymers (HBPs), such as hyperbranched polyglycerols (HPGs) with a dendritic configuration, have been recognized for their excellent biocompatibility and multifunctionalization. HPGs have been studied for use in the delivery diagnostic, imaging and therapeutic molecules in the area of nanobiomedicine. They show superior characteristics to linear polymers and dendrimers, such as compact structure, a simple manufacturing process with easy functionalization ability, low viscosity, and high stability. Owing to these advantages, HPGs are now considered promising carriers for drug delivery, diagnostics, imaging, and theranostics applications for cancer treatment. In this review, we also discuss safety aspects of HPG-based nanoformulations in various animal models and the clinical translation status of such polymers for real-time applications.

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

We have designed and developed curcumin (Ccn)-loaded albumin nanoparticles (BNPs) surface-functionalized with glycyrrhetinic acid (Ccn-BNP-GA) for GA receptor-mediated targeting. Ccn-BNP-GA was prepared by conjugating GA as a hepatoma cell-specific binding molecule onto the surface of BNPs. Ccn-BNP-GA showed a narrow distribution with an average size of 258.8±6.4 nm, a regularly spherical shape, an entrapment efficiency of 88.55%±5.54%, and drug loading of 25.30%±1.58%. The density of GA as the ligand conjugated to BNPs was 140.48±2.784 μg/g bovine serum albumin. Cytotoxicity assay results indicated that Ccn-BNP-GA was significantly more cytotoxic to HepG2 cells and in a concentration-dependent manner. Ccn-BNP-GA also appeared to be taken up to a greater extent by HepG2 cells than undecorated groups, which might be due to the high affinity of GA for GA receptors on the HepG2 cell surface. These cytotoxicity assay results were corroborated by analysis of cell apoptosis and the cell cycle. Further, Ccn-BNP-GA showed an approximately twofold higher rate of cell apoptosis than the other groups. Moreover, proliferation of HepG2 cells was arrested in G₂/M phase based on cell cycle analysis. These results, which were supported by the GA receptor-mediated endocytosis mechanism, indicate that BNPs surface-functionalized with GA could be used in targeted cancer treatment with high efficacy, sufficient targeting, and reduced toxicity.

Elucidating the in vivo fate of nanocrystals using a physiologically based pharmacokinetic model: a case study with the anticancer agent SNX-2112

Introduction

SNX-2112 is a promising anticancer agent but has poor solubility in both water and oil. In the study reported here, we aimed to develop a nanocrystal formulation for SNX-2112 and to determine the pharmacokinetic behaviors of the prepared nanocrystals.

Methods

Nanocrystals of SNX-2112 were prepared using the wet-media milling technique and characterized by particle size, differential scanning calorimetry, drug release, etc. Physiologically based pharmacokinetic (PBPK) modeling was undertaken to evaluate the drug’s disposition in rats following administration of drug cosolvent or nanocrystals.

Results

The optimized SNX-2112 nanocrystals (with poloxamer 188 as the stabilizer) were 203 nm in size with a zeta potential of −11.6 mV. In addition, the nanocrystals showed a comparable release profile to the control (drug cosolvent). Further, the rat PBPK model incorporating the parameters of particulate uptake (into the liver and spleen) and of in vivo drug release was well fitted to the experimental data following administration of the drug nanocrystals. The results reveal that the nanocrystals rapidly released drug molecules in vivo, accounting for their cosolvent-like pharmacokinetic behaviors. Due to particulate uptake, drug accumulation in the liver and spleen was significant at the initial time points (within 1 hour).

Conclusion

The nanocrystals should be a good choice for the systemic delivery of the poorly soluble drug SNX-2112. Also, our study contributes to an improved understanding of the in vivo fate of nanocrystals.

Mixed nanomicelles as potential carriers for systemic delivery of Z-GP-Dox, an FAPα-based doxorubicin prodrug: formulation and pharmacokinetic evaluation

Z-GP-Dox, the FAPα (fibroblast activation protein-α)-based doxorubicin prodrug, demonstrates excellent tumor targeting effects and a favorable toxicokinetic profile. However, the insoluble nature of Z-GP-Dox becomes a significant barrier to drug administration, particularly when it comes to the clinical stage. Here we developed a nanomicelle system to facilitate the systemic delivery of Z-GP-Dox, and evaluated its disposition in rats following administration of the micelles using a physiologically-based pharmacokinetic model. Z-GP-Dox-loaded mixed nanomicelles (ZGD-MNs) were prepared by dispersion of an ethanol solution of Z-GP-Dox, lecithin, and sodium oleate in water. The obtained ZGD-MNs were 86.6 nm in size with a drug loading of 14.03%. ZGD-MNs were fairly stable in phosphate-buffered saline and showed satisfactory physical and chemical stability over a 2-week observation period. Accumulative drug release was more than 56% within 24 hours. Further, the physiologically-based pharmacokinetic rat model consisting of various organs (ie, heart, liver, spleen, lung, kidney, and intestine) was fitted to the experimental data following administration of ZGD-loaded cosolvent (control) or micelles. Derived partition coefficient values revealed that the nanomicelles significantly altered the biodistribution of Z-GP-Dox. Of note, drug distribution to the lung, liver, and spleen was greatly enhanced and the fold change ranged from 2.4 to 33. In conclusion, this is the first report of a mixed micelle system being a viable carrier for delivery of Z-GP-Dox. Also, the pharmacokinetic behavior of Z-GP-Dox was satisfactorily described by the physiologically-based pharmacokinetic model.

Specific targeting of A54 homing peptide-functionalized dextran-g-poly(lactic-co-glycolic acid) micelles to tumor cells

The delivery of chemotherapeutics into tumor cells is a fundamental knot for tumor-target therapy to improve the curative effect and avoid side effects. Here, A54 peptide-functionalized poly(lactic-co-glycolic acid)-grafted dextran (A54-Dex-PLGA) was synthesized. The synthesized A54-Dex-PLGA self-assembled to form micelles with a low critical micelle concentration of 16.79 μg·mL⁻¹ and diameter of about 50 nm. With doxorubicin (DOX) base as a model antitumor drug, the drug-encapsulation efficiency of DOX-loaded A54-Dex-PLGA micelles (A54-Dex-PLGA/DOX) reached up to 75%. In vitro DOX release from the A54-Dex-PLGA/DOX was prolonged to 72 hours. The A54-Dex-PLGA micelles presented excellent internalization ability into hepatoma cells (BEL-7402 cell line and HepG2 cell line) in vitro, and the cellular uptake of the micelles by the BEL-7402 cell line was specific, which was demonstrated by the blocking experiment. In vitro antitumor activity studies confirmed that A54-Dex-PLGA/DOX micelles suppressed tumor-cell (BEL-7402 cell) growth more effectively than Dex-PLGA micelles. Furthermore, in vivo biodistribution testing demonstrated that the A54-Dex-PLGA micelles had a higher distribution ability to BEL-7402 tumors than that to HepG2 tumors.

Active radar guides missile to its target: receptor-based targeted treatment of hepatocellular carcinoma by nanoparticulate systems

Patients with hepatocellular carcinoma (HCC) usually present at advanced stages and do not benefit from surgical resection, so drug therapy should deserve a prominent place in unresectable HCC treatment. But chemotherapy agents, such as doxorubicin, cisplatin, and paclitaxel, frequently encounter important problems such as low specificity and non-selective biodistribution. Recently, the development of nanotechnology led to significant breakthroughs to overcome these problems. Decorating the surfaces of nanoparticulate-based drug carriers with homing devices has demonstrated its potential in concentrating chemotherapy agents specifically to HCC cells. In this paper, we reviewed the current status of active targeting strategies for nanoparticulate systems based on various receptors such as asialoglycoprotein receptor, transferrin receptor, epidermal growth factor receptor, folate receptor, integrin, and CD44, which are abundantly expressed on the surfaces of hepatocytes or liver cancer cells. Furthermore, we pointed out their merits and defects and provided theoretical references for further research.

Synthesis and evaluation of glyco-coated liposomes as drug carriers for active targeting in drug delivery systems

Novel sugar-conjugated cholesterols, β-Gal-, α-Man-, β-Man-, α-Fuc-, and β-Man-6P-S-β-Ala-Chol, were synthesized and incorporated into liposomes. In vitro experiments using the glyco-coated liposomes showed that the glyco-coated liposomes are efficiently taken up by cells expressing carbohydrate-binding receptors selectively. Glyco-coated liposomes are promising candidates for drug delivery vehicles.

Synthesis of liver-targeting dual-ligand modified GCGA/5-FU nanoparticles and their characteristics in vitro and in vivo

Nanoparticle drug delivery systems using polymers hold promise for clinical applications. We synthesized dual-ligand modified chitosan (GCGA) nanoparticles using lactic acid, glycyrrhetinic acid, and chitosan to target the liver in our previous studies. We then synthesized the GCGA/5-FU nanoparticles by conjugating 5-fluorouracil (5-FU) onto the GCGA nanomaterial, which had a mean particle size of 239.9 nm, a polydispersity index of 0.040, a zeta potential of +21.2 mV, and a drug loading of 3.90%. GCGA/5-FU nanoparticles had good slow release properties, and the release process could be divided into five phases: small burst release, gentle release, second burst release, steady release, and slow release. Inhibitory effects of GCGA/5-FU on tumor cells targeted the liver, and were time and dose dependent. GCGA nanoparticles significantly prolonged the efficacy of 5-FU on tumor cells, and alleviated the resistance of tumor cells to 5-FU. GCGA/5-FU nanoparticles were mostly concentrated in the liver, indicating that the GCGA nanoparticles were liver targeting. GCGA/5-FU nanoparticles significantly suppressed tumor growth in orthotopic liver transplantation mouse model, and improved mouse survival.

Efficient hepatic delivery of drugs: novel strategies and their significance

Liver is a vital organ responsible for plethora of functions including detoxification, protein synthesis, and the production of biochemicals necessary for the sustenance of life. Therefore, patients with chronic liver diseases such as viral hepatitis, liver cirrhosis, and hepatocellular carcinoma need immediate attention to sustain life and as a result are often exposed to the prolonged treatment with drugs/herbal medications. Lack of site-specific delivery of these medications to the hepatocytes/nonparenchymal cells and adverse effects associated with their off-target interactions limit their continuous use. This calls for the development and fabrication of targeted delivery systems which can deliver the drug payload at the desired site of action for defined period of time. The primary aim of drug targeting is to manipulate the whole body distribution of drugs, that is, to prevent distribution to non-target cells and concomitantly increase the drug concentration at the targeted site. Carrier molecules are designed for their selective cellular uptake, taking advantage of specific receptors or binding sites present on the surface membrane of the target cell. In this review, various aspects of liver targeting of drug molecules and herbal medications have been discussed which elucidate the importance of delivering the drugs/herbal medications at their desired site of action.