Synthesis of manganese-incorporated polycaplactone-poly (glyceryl methacrylate) theranostic smart hybrid polymersomes for efficient colon adenocarcinoma treatment.

In the current study, a multifunctional nanoscale vesicular system (polymersome) with the ability to accumulate in the site of action, control drug release and integrate diagnostic and therapeutic functions was developed. The theranostic polymersome was engineered as a promising dual-functional nanoplatform, which can be used for tumor therapy and magnetic resonance imaging (MRI). In this regard, the amphiphilic diblock copolymer of poly(ε-caprolactone)-block-poly(glyceryl methacrylate)[(PCL-b-PGMA)] was synthesized by combined ring-opening polymerization (ROP), and reversible addition-fragmentation chain-transfer (RAFT) polymerization techniques followed by hydrolysis of the pendant oxiran rings to hydroxyl groups. Because of the amphiphilic properties and desirable hydrophobic/hydrophilic balance of the synthesized copolymer, it could self-assemble to form a polymersomal structure in an aqueous environment (with diameters about 100-145 nm). The hydrophilic anticancer drug, doxorubicin (DOX) and hydrophobic paramagnetic Mn (phenanthroline)2 complex, being well-represented on T1-weighted magnetic resonance imaging (MRI), were encapsulated in the hydrophilic core (33%±2.3 efficiency) and hydrophobic bilayer membrane (100 %efficient) of a polymersome system, respectively to provide PCL-PGMA@Mn(phen)2/DOX NPs. It was found that adding aptamer AS1411 to NPs surfaces enhanced their specificity and selectivity towards colorectal cancer cells expressing nucleolin (HT29 and C26). In vivo evaluation after intravenous administration of the prepared platform was performed using subcutaneous C26 tumor-bearing Balb/C mice. The obtained results demonstrated that the prepared targeted platform provided a reduced systemic toxicity in terms of body weight loss and mortality while showing efficient tumor regression. Furthermore, the prepared theranostic platform afforded MRI imaging capability for tumor monitoring. It could be concluded that the biocompatible PCL-PGMA magnetic DOX-loaded polymersomes could serve as a versatile multifunctional system for simultaneous tumor imaging and therapy.

Evaluation of the osteogenic potential of crocin-incorporated collagen scaffold on the bone marrow mesenchymal stem cells.

OBJECTIVE: The present study aimed to evaluate the effect of crocin (CRO)-loaded collagen (COL) scaffold on the osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BM-MSCs). SIGNIFICANCE: Different studies have been conducted to develop an efficient strategy to accelerate and improve the recovery process of bone defects. It was shown that CRO, extracted from saffron, could induce osteogenic differentiation of rat BM-MSCs. Scaffolds can also provide a three-dimensional environment for migration, adhesion, growth, and proliferation of MSCs. METHODS: Collagen scaffolds were fabricated through freeze-drying followed by cross-linking by dehydrothermal method. Then, CRO was incorporated into the scaffolds. Physicochemical characterization of the scaffolds was evaluated. Rat BM-MSCs were seeded on CRO-loaded COL scaffolds and cultured for 14 days. Osteogenic differentiation was evaluated using alizarin red (ALZ) staining and alkaline phosphatase (ALP) activity assay and compared to the positive control group. RESULTS: The average pore size of the COL scaffolds was about 97 ± 6.7 µm. Formation of amide cross-links was confirmed by FTIR. The scaffolds were capable of uptaking water up to 50 times more than their initial dry weight and releasing above 90% of their uploaded CRO during 24 h. Collagen scaffolds containing CRO (25 and 50 µM) increased ALZ intensity (3.16 ± 0.3 and 7.32 ± 0.3 folds, respectively) and ALP activity (13.7 ± 1.1 and 12.2 ± 9.4 folds, respectively) in comparison with the positive control group. CONCLUSION: Crocin-loaded COL scaffold could effectively enhance calcium deposition and ALP activity in BM-MSCs and therefore proposed as a good candidate to accelerate the healing process of vital bone defects.

Evaluation of debridement effects of bromelain-loaded sodium alginate nanoparticles incorporated into chitosan hydrogel in animal models.

OBJECTIVES: Bromelain, a mixture of proteolytic enzymes from pineapple (Ananas comosus) is known as a potential debriding agent in burn treatment. In this research, the debridement efficiency of chitosan hydrogel loaded by sodium alginate-chitosan nanoparticles (NPs) containing bromelain (Br 10%-AG-CS NPs) was evaluated in animal models. MATERIALS AND METHODS: The NPs were prepared using the ionic gelation technique and their properties were identified. Then, the debridement effect of bromelain NPs incorporated into chitosan hydrogel was evaluated 4 hr after wound treatment in animal models. RESULTS: The particle size of positively charged Br-AG-Cs NPs was about 390±25 nm. The encapsulation efficiency of bromelain into AG-CS NPs was about 92%. The in vitro release profile showed that the maximum release of bromelain from NPs occurred during the first 4 hr (70%). The hydrogel structure did not significantly affect the profile release of bromelain in the formulation. After 6 months of storage at 4 and 25 °C, the synthesized NPs indicated no significant changes in bromelain activity. It was found that Br 10%-Ag-Cs NPs-CS hydrogel had the most beneficial effects on reducing necrotic tissues and resulted in re-epithelialization compared with other treated groups (negative and positive control, CS hydrogel, and Br 10%-CS hydrogel). CONCLUSION: Therefore, using this novel formulation can be considered a potential debridement agent.

DNA G-quadruplexes binding and antitumor activity of palladium aryl oxime ligand complexes encapsulated in either albumin or algal cellulose nanoparticles.

The interactions between two Pd complexes, designated as [Pd3(C,N-(C6H4C(Cl) = NO)-4)6] (complex 1) and [Pd3(C12H8C = NO)6] (complex 2), with the human telomeric G-quadruplex DNA, 5'-G3(T2AG3)3-3' (HTG21), were monitored using spectroscopic, biological, and molecular modeling studies. According to the UV-vis results, these complexes can strongly induce and stabilize G-quadruplex DNA structure with Kb1 = 4.5(±0.3) × 106 M-1 and Kb2 = 1.0(±0.2) × 107 M-1via groove mode in comparison with duplex DNA. The release mechanism of the Pd complexes from BSA nanoparticles followed a biphasic pattern unlike that of algal cellulose nanoparticles in vitro. In addition, the cytotoxicity of these complexes on MCF-7 cancer cells and PBMC normal cells was evaluated and compared with cisplatin under similar experimental conditions. Furthermore, to determine and verify the interaction mode of these compounds with G-quadruplex, the molecular docking technique was also performed. Our data clearly demonstrated that complex 2 had higher activity and cytotoxicity than that of complex 1 and could be further investigated in the future as a drug discovery platform.

Comparison of the effect of crocin and crocetin, two major compounds extracted from saffron, on osteogenic differentiation of mesenchymal stem cells.

BACKGROUND: Mesenchymal stem cells (MSCs) can be considered as an effective tool for bone regeneration. It is variable to find new agents with low cytotoxicity and high efficiency for induction of MSCs into osteoblasts. In the present study, the ability of crocin and crocetin, extracted from saffron, to induce cell differentiation of rat bone marrow-derived mesenchymal stem cells (rat BM-MSCs) into osteoblasts was compared. METHODS: Bone marrow cells were isolated from rat's femurs and tibias. Cytotoxic effect of crocin and crocetin was assayed using MTT test and IC50 was calculated from the results. Osteogenic ability of crocin and crocetin at non-toxic concentrations has been evaluated and compared to osteogenic standard medium after 7 and 21 days, using alizarin red (ALZ) staining and alkaline phosphatase (ALP) activity. Furthermore, ALP mRNA expression has been analyzed by real time RT-PCR. RESULTS: Crocetin showed more cytotoxic effect on stem cells compared to crocin. Non-toxic concentrations (12.5, 25 and 50 µM) were selected for other experiments. Crocin and crocetin (25 µM) increased ALZ intensity (4.2 ±â€¯0.12 and 3.8 ±â€¯0.16 folds, respectively), ALP activity (46.4 ±â€¯5.8 and 43.2 ±â€¯1.9 folds, respectively) and ALP mRNA expression (14.27 ±â€¯1.98 and 8.4 ±â€¯1.17 folds, respectively) in MSCs after day 21 compared to negative control. Although, crocin was more effective than crocetin, but this difference was not significant. CONCLUSION: According to these findings, crocin and crocetin could effectively enhance osteogenic differentiation of MSCs and can be considered as safe therapeutic agents in clinical applications.

Tetrac-decorated chitosan-coated PLGA nanoparticles as a new platform for targeted delivery of SN38.

New integrin-targeted nanoparticles made of chitosan-stabilized PLGA matrix was developed to specifically target colon adenocarcinoma. To this aim, SN38-encapsulated chitosan-coated PLGA NPs were conjugated with tetrac for integrin receptor-guided delivery. To provide a sustained release pattern for SN38, it was loaded into nanoparticles using single emulsion method. The size of NPs were 174.23 ± 6.12 nm with drug encapsulation efficiency and loading content of 73.16 ± 11.15 and 4.45 ± 0.31, respectively. The in vitro results confirmed that the designed nanoplatform showed specific cellular uptake and cytotoxicity in integrin overexpressing cancer cells and provided a sustained release profile for SN38. Additionally, an increased therapeutic potency of targeted formulation over both non-targeted and free drug was shown in vivo.

Evaluation of Efficiency of Modified Polypropylenimine (PPI) with Alkyl Chains as Non-viral Vectors Used in Co-delivery of Doxorubicin and TRAIL Plasmid.

In this study, co-delivery system was achieved via plasmid encoding TNF related apoptosis inducing ligand (pTRAIL) and doxorubicin (DOX) using carrier based on polypropylenimine (PPI) modified with 10-bromodecanoic acid. Incorporation of alkylcarboxylate chain to PPIs (G4 and G5) could improve transfection efficiency via overcoming the plasma membrane barrier of the cells and decrease cytotoxicity of PPI. Characterization of fabricated NPs revealed that PPI G5 in which 30% of primary amines were substituted by alkyl carboxylate chain (PPI G5-Alkyl 30%) has higher drug loading as compared to the other formulations. PPI G5-Alkyl 30% indicated a decreased drug release may be due to alkyl chains on the surface of PPI, which serve as an additional hindrance for drug diffusion. In vitro cytotoxicity experiments demonstrated that co-delivery system induced apoptosis of tumor cells more efficiently than each of delivery system alone. Furthermore, these results revealed that our combined delivery platform of pTRAIL and DOX using Alkyl-modified PPI G5 can significantly improve the anti-tumor activity and this strategy might develop a new therapeutic window for cancer treatment.

Synthesis of theranostic epithelial cell adhesion molecule targeted mesoporous silica nanoparticle with gold gatekeeper for hepatocellular carcinoma.

AIM: In this study, we report the fabrication of epithelial cell adhesion molecule targeted 5-fluorouracil (5-FU) encapsulated PEGylated mesoporous silica nanoparticles (NPs) hybridized with gold NPs (PEG-Au@Si-5-FU) as gatekeeper for theranostic applications. MATERIALS & METHODS: The prepared targeted and nontargeted formulations were evaluated in vitro in terms of their cellular internalization and toxicity. The prepared theranostic hybrid system was also implemented for computed tomography of HepG2 tumor-bearing nude mice in vivo. RESULTS: Fluorescence microscopy and MTT assay demonstrated that the developed epithelial cell adhesion molecule-PEG-Au@Si-5-FU had higher cytotoxicity than nontargeted PEG-Au@Si-5-FU in 2D and 3D HepG2 cell cultures. Moreover, the targeted hybrid system was preferentially accumulated in HepG2 tumor cells in vitro and in vivo. CONCLUSION: This work introduces a novel strategy for developing multimodal NPs via nanoparticulate hybrid materials.

Comparison study of the effect of alkyl-modified and unmodified PAMAM and PPI dendrimers on solubility and antitumor activity of crocetin.

Poor water solubility of hydrophobic drugs is one of the major problems in pharmaceutical sciences. Herein, in order to address the poor solubility of crocetin, the 30% of primary amines of PAMAM G4 and PPI G4 were alkylated and evaluated as drug delivery vectors. According to the results, this modification could improve the drug delivery efficiency in term of drug solubility, release pattern and cytotoxicity; however, the encapsulation yield was decreased. Accordingly, it can be concluded that the designed alkylated dendrimers are able to improve the drug delivery efficiency, may be through improving the solubility and cellular uptake of crocetin.

Gene delivery efficiency and cytotoxicity of heterocyclic amine-modified PAMAM and PPI dendrimers.

Poly-(amidoamine) (PAMAM) and poly-(propylenimine) (PPI) are the two most widely investigated dendrimers for drug and gene delivery. In order to enhance DNA transfection activity of these dendrimers, generation 3 and 4 PAMAM and generation 4 and 5 PPI were modified by partial substitution of surface primary amines with histidine, pyridine, and piperazine, which have buffering capacity properties. It was shown that higher dendrimer generations and higher grafting percentages (30% and 50% of primary amines) were associated with higher transfection activity. Pyridine was the most effective substituent for PPI, while piperazine-modified PAMAM dendrimers showed the best transfection efficiency among PAMAM-based vectors in murine neuroblastoma (Neuro-2a) cells. None of the modified carriers showed remarkable cytotoxicity in vitro. Pretreatment of cells with bafilomycin A indicated that endosomal buffering capacity is the main mechanism of endosomal escape. In conclusion, PAMAM and PPI may exhibit different gene delivery efficiency and cytotoxicity profiles with the same chemical modifications. These modified dendrimers could be considered as efficient and safe gene carriers in neuroblastoma cells in vitro.

Effects of rutin on acrylamide-induced neurotoxicity.

BACKGROUND: Rutin is an important flavonoid that is consumed in the daily diet. The cytoprotective effects of rutin, including antioxidative, and neuroprotective have been shown in several studies. Neurotoxic effects of acrylamide (ACR) have been established in humans and animals. In this study, the protective effects of rutin in prevention and treatment of neural toxicity of ACR were studied. RESULTS: Rutin significantly reduced cell death induced by ACR (5.46 mM) in time- and dose-dependent manners. Rutin treatment decreased the ACR-induced cytotoxicity significantly in comparison to control (P <0.01, P < 0.001). Rutin (100 and 200 mg/kg) could prevent decrease of body weight in rats. In combination treatments with rutin (50, 100 and 200 mg/kg), vitamin E (200 mg/kg) and ACR, gait abnormalities significantly decreased in a dose-dependent manner (P < 0.01 and P < 0.001). The level of malondialdehyde significantly decreased in the brain tissue of rats in both preventive and therapeutic groups that received rutin (100 and 200 mg/kg). CONCLUSION: It seems that rutin could be effective in reducing neurotoxicity and the neuroprotective effect of it might be mediated via antioxidant activity.

Arginine-rich hydrophobic polyethylenimine: potent agent with simple components for nucleic acid delivery.

Conjugation of various arginine-rich peptide sequences to vectors based on 10 kDa polyethylenimine (PEI) and its hydrophobic derivative (hexanoate-PEI) was investigated as a strategy for improving pDNA and siRNA transfection activities. Six different arginine-histidine (RH) sequences and two arginine-serine (RS) sequences with a range of R/H ratios were designed and coupled to PEI and hexanoate-PEI. All arginine-rich peptide derivatives of PEI significantly enhanced luciferase gene expression compared to PEI 10 kDa alone. Hexanoate-PEI derivatives exhibited higher transfection activity than underivatized PEI vectors. Improved transfection activity may have resulted at least in part from use of higher vector/DNA ratios made possible by reduced cytotoxicity of vectors, and to use of vectors with higher molecular weights. Vectors that were the most efficient in pDNA delivery and transfection were also the most effective in siRNA delivery and protein expression knock down.

Development and Validation of HPLC Method for Determination of Crocetin, a constituent of Saffron, in Human Serum Samples.

OBJECTIVE(S): The present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. MATERIALS AND METHODS: The HPLC method was carried out by using a C18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow rate of 0.8 ml/min. The UV detector was set at 423 nm and 13-cis retinoic acid was used as the internal standard. Serum samples were pretreated with solid-phase extraction using Bond Elut C18 (200mg) cartridges or with direct precipitation using acetonitrile. RESULTS: The calibration curves were linear over the range of 0.05-1.25 µg/ml for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction. The mean recoveries of crocetin over a concentration range of 0.05-5 µg/ml serum for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction were above 70 % and 60 %, respectively. The intraday coefficients of variation were 0.37- 2.6% for direct precipitation method and 0.64 - 5.43% for solid-phase extraction. The inter day coefficients of variation were 1.69 - 6.03% for direct precipitation method and 5.13-12.74% for solid-phase extraction, respectively. The lower limit of quantification for crocetin was 0.05 µg/ml for direct precipitation method and 0.5 µg/ml for solid-phase extraction. CONCLUSION: The validated direct precipitation method for HPLC satisfied all of the criteria that were necessary for a bioanalytical method and could reliably quantitate crocetin in human serum for future clinical pharmacokinetic study.