Formulation and optimization of a single-layer coat for targeting budesonide pellets to the descending Colon.

The current budesonide formulations are inadequate for addressing left-sided colitis, and patients might hesitate to use an enema for a prolonged time. This study focuses on developing a single-layer coating for budesonide pellets targeting the descending colon. Pellets containing budesonide (1.5%w/w), PVP K30 (5%w/w), lactose monohydrate (25%w/w) and Avicel pH 102 (68.5%w/w) were prepared using extrusion spheronization technique. Coating formulations were designed using response surface methodology with pH and time-dependent Eudragits. Dissolution tests were conducted at different pH levels (1.2, 6.5, 6.8, and 7.2). Optimal coating formulation, considering coating level and the Eudragit (S + L) ratio to the total coating weight, was determined. Budesonide pellets were coated with the optimized composition and subjected to continuous dissolution testing simulating the gastrointestinal tract. The coating, with 48% S, 12% L, and 40% RS at a 10% coating level, demonstrated superior budesonide delivery to the descending colon. Coated pellets had a spherical shape with a uniform 30 µm thickness coating, exhibiting pH and time-dependent release. Notably, zero-order release kinetics was observed for the last 9 h in colonic conditions. The study suggests that an optimized single-layer coating, incorporating pH and time-dependent polymers, holds promise for consistently delivering budesonide to the descending colon.

Transglutaminases in fibrosis-overview and recent advances.

Transglutaminases (TGs) are a family of protein cross-linking enzymes that are capable of stiffening and insolubilizing proteins and creating protein networks, and thereby altering biological functions of proteins. Their role in fibrosis progression has been widely investigated with a focus on kidney, lung, liver, and heart where activity is triggered by various stimuli including hypoxia, inflammation, and hyperglycemia. TG2 has been considered one of the key enzymes in the pathogenesis of fibrosis mainly through transforming growth factor beta (TGF-beta) signaling and matrix cross-linking mechanisms. Although TG2 has been most widely studied in this context, the involvement of other TGs, TG1 and Factor XIII-A (FXIII-A), is beginning to emerge. This mini-review highlights the major steps taken in the TG and fibrosis research and summarizes the most recent advances and contributions of TG2, TG1, and FXIII-A to the progression of fibrosis in various animal models. Also, their mechanisms of action as well as therapeutic prospects are discussed.

PNA-ATP aptamer-capped doxorubicin-loaded silica nanoparticles for targeted cancer therapy.

Nanomaterial-based drug delivery has opened new horizons in cancer therapy. This study aimed to investigate the in vitro and in vivo anti-cancer effects of a hyaluronic acid (HA)-targeted nanocarrier based on hollow silica nanoparticles (HSNPs), gated with peptide nucleic acid (PNA) and ATP aptamer (ATPApt) and loaded with doxorubicin (DOX). After formulation of a smart drug delivery nanosystem (HSNPs/DOX/ATPApt/PNA/HA), drug release, cytotoxicity, uptake, and in vivo anti-tumor properties were studied. Drug release test showed the controlled release of encapsulated DOX in response to ATP content. MTT and flow cytometry indicated that HA could improve both cytotoxicity and cellular uptake of the formulation. Moreover, HA-targeted formulation enhanced both the survival rate and tumor inhibition in the tumor-bearing mice compared with free DOX (P < 0.05). Our findings confirmed that HA-targeted nanoformulation, gated with PNA/aptamer and loaded with DOX can provide a novel therapeutic platform with great potential for cancer therapy.

Differentiation of human adipose-derived mesenchymal stem cells toward tenocyte by platelet-derived growth factor-BB and growth differentiation factor-6.

Mesenchymal Stem Cells (MSCs) are important in regenerative medicine and tissue engineering and will be a very sensible choice for repair and regeneration of tendon. New biological practices, such as cellular therapy using stem cells, are promising for facilitating or expediting tendon therapy. Before using these cells clinically, it is best to check and confirm the optimal conditions for differentiation of these cells in the laboratory. Hence, in the present study, the impacts of PDGF-BB and GDF-6 supplementation on adipose-derived MSCs (ASCs) culture were studied. The frozen ASC were recovered and expanded in basic culture medium (DMEM with 10%FBS). The cells after passage five (P5) were treated with basic medium containing L-Prolin, Ascorbic Acid and only PDGF-BB or GDF-6 (20 ng/ml) or both of them (mix) as 3 groups for 14 days to investigate efficiency of ASCs differentiation towards tenocytes. The cells culturing in basic medium were used as control group. To validate tenogenic differentiation, H&E and Sirius Red staining were used to assess cell morphology and collagen production, respectively. In addition, mRNA levels of collagen I and III, Scleraxis and Tenomodulin as tenogenic markers were analyzed using qPCR. In all test groups, cells appeared slenderer, elongated cytoplasmic attributes compared to the control cells. The intensity of Sirius Red staining was significantly higher in GDF-6, PDGF-BB alone, than in group without supplements. The optical density was higher in the GDF-6 than PDGF-BB and mix-group. QPCR results showed that Col I and III gene expression was increased in all groups compared to the control. SCX expression was significantly increased only in the PDGF-BB group. TNMD mRNA expression was not significant among groups. In this study, we have corroborated that human ASCs are reactionary to tenogenic induction by GDF-6 and PDGF-BB alone or in combination. These outcomes will help greater insight into GDF-6 and PDGF-BB driven tenogenesis of ASCs and new directions of discovery in the design of ASC-based treatments for tendon healing.

Induction of tenogenic differentiation of equine adipose-derived mesenchymal stem cells by platelet-derived growth factor-BB and growth differentiation factor-6.

Managing tendon healing process is complicated mainly due to the limited regeneration capacity of tendon tissue. Mesenchymal stem cells (MSCs) have potential applications in regenerative medicine and have been considered for tendon repair and regeneration. This study aimed to evaluate the capacity of equine adipose tissue-derived cells (eASCs) to differentiate into tenocytes in response to platelet-derived growth factor-BB (PDGF-BB) and growth differentiation factor-6 (GDF-6) in vitro. Frozen characterized eASCS of 3 mares were thawed and the cells were expanded in basic culture medium (DMEM supplemented with 10% FBS). The cells at passage 5 were treated for 14 days in different conditions including: (1) control group in basic culture medium (CM), (2) induction medium as IM (CM containing L-prolin, and ascorbic acid (AA)) supplemented with PDGF-BB (20 ng/ml), (3) IM supplemented with GDF-6 (20 ng/ml), and (4) IM supplemented with PDGF-BB and GDF-6. At the end of culture period (14th day), tenogenic differentiation was evaluated. Sirius Red staining was used to assess collagen production, and H&E was used for assessing cell morphology. mRNA levels of collagen type 1 (colI), scleraxis (SCX), and Mohawk (MKX), as tenogenic markers, were analyzed using real-time reverse-transcription polymerase chain reaction (qPCR). H&E staining showed a stretching and spindle shape (tenocyte-like) cells in all treated groups compared to unchanged from of cells in control groups. Also, Sirius red staining data showed a significant increase in collagen production in all treated groups compared with the control group. MKX expression was significantly increased in PDGF-BB and mixed groups and COLI expression was significantly increased only in PDGF-BB group. In conclusion, our results showed that PDGF-BB and GDF-6 combination could induce tenogenic differentiation in eASCs. These in vitro findings could be useful for cell therapy in equine regenerative medicine.

Designing a multifunctional staphylokinase variant (SAK-2RGD-TTI) with appropriate thrombolytic activity in vitro.

OBJECTIVE: Thrombin, platelets, and plasmin are three key factors involved in hemostasis and thrombolysis. Thrombolytic therapy with clinically approved drugs is often followed by recurrent thrombosis caused by thrombin-induced platelet aggregation from the clot debris. In order to minimize these problems, new constructs were designed for the expression of recombinant staphylokinase (rSAK) and also a fusion protein composed of staphylokinase, 20 amino acids containing 2 RGD followed by tsetse thrombin Inhibitor (SAK-2RGD-TTI) in Pichia pastoris. RESULT: Modeling the tertiary structure of SAK-2RGD-TTI showed that the linker containing RGD and TTI did not interfere with proper folding of SAK. In laboratory testing, the purified SAK-2RGD-TTI (420 µg/mL) dissolved an average of 45% of the blood clot. The activity of the SAK-2RGD-TTI was also confirmed in various tests including human plasminogen activation assay, fibrin clot lysis assay, well diffusion method, activated partial thromboplastin time and platelet rich clot lysis assay. CONCLUSION: Our findings suggest that SAK-2RGD-TTI has improved therapeutic properties preventing reocclussion. It further confirms that it is practicable to assemble and produce a hybrid multifunctional protein that targets hemostatic process at various stages.

Design, Synthesis, and In Vitro Evaluation of Low Molecular Weight Protamine (LMWP)-Based Amphiphilic Conjugates as Gene Delivery Carriers.

Development of efficient non-viral carriers is one of the major challenges of gene delivery. In the current study, we designed, synthesized, and evaluated the in vitro gene delivery efficiency of novel amphiphilic constructs composed of cholesterol and low molecular weight protamine (LMWP: VSRRRRRRGGRRRR) peptide. Vectors having both hydrophobic and hydrophilic moieties were evaluated in terms of particle size and charge, DNA condensation ability, cytotoxicity, and gene transfection efficiency. The prepared vectors spontaneity self-assembled into the liposome-like particles with a high local positive density. The nano-vehicle A (H5-LMWP-Cholestrol) and nano-vehicle B (LMWP-Cholesterol) could form micelles at concentrations above 50 µg/mL and 65 µg/mL, respectively. The gel retardation assay showed that nano-vehicles A and B could condense pDNA more efficiently than the corresponding unconjugated peptides. The mean of size and zeta potential of complexed nano-vehicle A at N/P ratios of 5, 15, and 30 were 151 nm and 23 mv, and those of nano-vehicle B were 224 nm and 19 mv, respectively. In terms of transfection efficiency, the designed nano-vehicles showed almost two-fold higher gene expression level compared to PEI 25 kDa at optimal N/P ratios, and also exhibited negligible cytotoxicity on a model cancer cell, Neuro 2a. The findings of the present study revealed that these cationic micelles can be promising candidates as non-viral gene delivery vehicles.

MUC1 aptamer-targeted DNA micelles for dual tumor therapy using doxorubicin and KLA peptide.

Targeted delivery of DNA nanoparticles is a promising approach in cancer therapy. Using aptamers, target specific delivery of DNA nanoparticles can be achieved. Further, aptamers can indirectly improve drug encapsulation efficiency of DNA nanoparticles for drugs intercalated within nucleic acid base pairs. Using DNA blocks, a micellar hybrid nanoparticle was prepared for the targeted co-delivery of doxorubicin and a pro-apoptotic peptide, KLA to tumor cells. Results demonstrated that anti-MUC1 aptamer could specifically deliver the synthesized DNA micelle into MCF-7 cells by improving its cellular uptake. Additionally, co-delivery of doxorubicin and KLA could significantly enhance the therapeutic efficacy of the construct resulting in reduction of required dose of doxorubicin that is a pivotal point in reducing chemotherapeutics side effects. Moreover, DOX-KLA-anti-MUC1-micelle remarkably inhibited tumor growth of tumor-bearing mice when compared with free drug. DOX-KLA-anti-MUC1-micelle also reduced toxic effect of free doxorubicin as determined by percent of body weight loss and survival rate in vivo.

High-level expression of a biologically active staphylokinase in Pichia pastoris.

Staphylokinase (SAK) as the third generation thrombolytic molecule is a promising agent for the treatment of thrombosis. SAK variant of SAKфC was expressed in Pichia pastoris strains KM71H and GS115. The codon adaptation index of SAK was improved from 0.75 to 0.89. The expression of recombinant SAK (rSAK) reached to its maximum (310 mg/L of the culture medium) after 48-hr stimulation with 3% methanol and remained steady until day 5. The maximum activity of the enzyme was at pH 8.6 and 37°C. It was highly active at temperatures 20-37°C and pH ranges of 6.8-9 (relative residual activity more than 80%). It was determined that rSAK was 73.8% of the total proteins secreted by P. pastoris KM71H into the culture media. The specific activities of rSAK were measured as 9,002 and 21,042 U/mg for the nonpurified and purified proteins, respectively. The quantity of the purified protein (>99% purity) was 720 µg/mL with a purification factor of 2.34. Western blot analysis showed two bands of nearly 22 and 18.6 kDa. It was concluded that P. pastoris is a proper host for expression of biologically active and endotoxin-free rSAK due to its high expression and low protein impurity in culture supernatant.

Antioxidant and anti-inflammatory properties of the citrus flavonoids hesperidin and hesperetin: an updated review of their molecular mechanisms and experimental models.

Inflammation and oxidative stress are two major causes of various life-threatening diseases. Hesperidin (Hsd) and its aglycone, hesperetin (Hst), are two flavonoids from citrus species that have numerous biological properties, particularly antioxidant and anti-inflammatory. New findings showed that the antioxidant activity of Hsd/Hst was not only limited to its radical scavenging activity, but it augmented the antioxidant cellular defenses via the ERK/Nrf2 signaling pathway as well. Various in vitro and in vivo studies have been conducted to evaluate Hsd, its metabolites, or its synthetic derivatives at reducing inflammatory targets including NF-κB, iNOS, and COX-2, and the markers of chronic inflammation. In this review, new findings regarding the molecular targets of Hsd and Hst in the reduction of oxidative stress are discussed. Also, in the anti-inflammatory section, we provide a summary of significant investigations concerning the mechanisms of action based on the studied inflammation models.

Assessment of protective effects of glucosamine and N-acetyl glucosamine against DNA damage induced by hydrogen peroxide in human lymphocytes.

The antigenotoxic activity of glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) in human peripheral lymphocytes exposed to oxidative stress was investigated. Human lymphocytes were treated with different concentrations of these aminosugars (0, 2.5, 5, 10, 20 and 40 mM) and 25 µM H2O2 simultaneously and evaluated by single cell gel electrophoresis technique (Comet assay). The single cells were analyzed using "TriTek Cometscore version 1.5" software and the data were presented as % DNA in tail. Both GlcN and GlcNAc at examined concentrations (2.5, 5, 10, 20 and 40 mM) did not reveal any genotoxicity compared to the vehicle control (PBS). Glucosamine at all concentrations (2.5, 5, 10, 20 and 40 mM) showed a significant protective activity (% DNA in tail ranging from 16.07 ± 0.85 to 5.47 ± 0.26, p < 0.001) against H2O2 induced DNA damage (% DNA in tail = 38 ± 0.65) while its N-acetylated analog only indicated a slight DNA protection at concentration of 40 mM (% DNA in tail = 33.4 ± 1.17, p < 0.01). We concluded that GlcN at tested concentrations exhibited potent antigenotoxic effect and its protection activity might be related to the presence of 2-NH2 moiety in its chemical backbone.

Antigenotoxic activities of the natural dietary coumarins umbelliferone, herniarin and 7-isopentenyloxy coumarin on human lymphocytes exposed to oxidative stress.

The antigenotoxic effects of umbelliferone (UMB), herniarin (HER) and 7-isopentenyloxy coumarin (7-IP), common natural dietary coumarins, were evaluated on the human lymphocyte DNA damage using single-cell gel electrophoresis. H(2)O(2)-induced DNA break was measured based on the percentage of DNA in tail, and the antigenotoxic effects of the tested compounds were compared with that of ascorbic acid (10, 25, 50, 100 and 200 µM). UMB, HER and 7-IP did not show any genotoxicity, as compared to phosphate-buffered saline. Treatment with UMB, HER and 7-IP led to a significant reduction in the percentage of DNA in tail induced by H(2)O(2) (p < 0.001) at all concentrations. The presence of prenyl moiety in the chemical structure of 7-IP may contribute to its better antigenotoxic property, compared to UMB. The results of this study showed that 7-IP possessed the best antigenotoxic activity among the tested compounds.

A review on bio-electro-Fenton systems as environmentally friendly methods for degradation of environmental organic pollutants in wastewater.

Bio-electro-Fenton (BEF) systems have been potentially studied as a promising technology to achieve environmental organic pollutants degradation and bioelectricity generation. The BEF systems are interesting and constantly expanding fields of science and technology. These emerging technologies, coupled with anodic microbial metabolisms and electrochemical Fenton's reactions, are considered suitable alternatives. Recently, great attention has been paid to BEFs due to special features such as hydrogen peroxide generation, energy saving, high efficiency and energy production, that these features make BEFs outstanding compared with the existing technologies. Despite the advantages of this technology, there are still problems to consider including low production of current density, chemical requirement for pH adjustment, iron sludge formation due to the addition of iron catalysts and costly materials used. This review has described the general features of BEF system, and introduced some operational parameters affecting the performance of BEF system. In addition, the results of published researches about the degradation of persistent organic pollutants and real wastewaters treatment in BEF system are presented. Some challenges and possible future prospects such as suitable methods for improving current generation, selection of electrode materials, and methods for reducing iron residues and application over a wide pH range are also given. Thus, the present review mainly revealed that BEF system is an environmental friendly technology for integrated wastewater treatment and clean energy production.

Smac peptide and doxorubicin-encapsulated nanoparticles: design, preparation, computational molecular approach and in vitro studies on cancer cells.

The N-terminal sequence of the Smac (second-mitochondria derived activator) protein is known to be involved in binding to the BIR3 (Baculovirus IAP repeat) domain of the IAPs (inhibitors of apoptosis proteins), and antagonized their function. Short peptides derived from N-terminal residues of Smac have shown to sensitize cancer cells to chemotherapeutic agents. In this regard, small library including 6-mer peptides were designed using docking to the BIR3 domain of cIAP1 in silico. Molecular dynamics simulation studies were also done on top-scored hits (SmacAQ, SmacIQ) using Desmond 2017-2 for 150 ns simulation time. These two peptides were conveniently synthesized using solid phase peptide synthesis on Fmoc-Gln (Trt)-Wang resin. Furthermore, we encapsulated DOX (doxorubicin) and synthesized peptides in PLGA: PLGA-PEG (9:1) NPs (nanoparticles) followed by MD (molecular dynamic) studies to understand the NP structure and the interactions between either DOX or peptide with polymeric nanoparticles during 100 ns simulation. Finally, the cytotoxic activity of these peptides in combination with DOX against two cancer cell lines including MCF7 and C26 were investigated. As a result, we found that DOX or peptide-loaded NPs had stable structure during the simulation. MD simulation also showed that alanine at N-terminal of Smac could be replaced with isoleucine without alternation of biological activity which was in agreement with in vitro experiments. Moreover, NPs-SmacIQ and NPs-SmacAQ significantly enhanced the cytotoxicity effect of NPs-DOX in vitro (p < 0.001).Communicated by Ramaswamy H. Sarma.

Preparation and Characterization of a Novel Multiparticulate Dosage Form Carrying Budesonide-Loaded Chitosan Nanoparticles to Enhance the Efficiency of Pellets in the Colon.

An attempt was made to conquer the limitation of orally administered nanoparticles for the delivery of budesonide to the colon. The ionic gelation technique was used to load budesonide on chitosan nanoparticles. The nanoparticles were investigated in terms of size, zeta potential, encapsulation efficiency, shape and drug release. Then, nanoparticles were pelletized using the extrusion-spheronization method and were investigated for their size, mechanical properties, and drug release. Pellets were subsequently coated with a polymeric solution composed of two enteric (eudragit L and S) and time-dependent polymers (eudragit RS) for colon-specific delivery. All formulations were examined for their anti-inflammatory effect in rats with induced colitis and the relapse of the colitis after discontinuation of treatment was also followed. The size of nanoparticles ranged between 288 ± 7.5 and 566 ± 7.7 nm and zeta potential verified their positive charged surface. The drug release from nanoparticles showed an initial burst release followed by a continuous release. Pelletized nanoparticles showed proper mechanical properties and faster drug release in acidic pH compared with alkaline pH. It was interesting to note that pelletized budesonide nanoparticles released the drug throughout the GIT in a sustained fashion, and had long-lasting anti-inflammatory effects while rapid relapse was observed for those treated with conventional budesonide pellets. It seems that there is a synergistic effect of nanoformulation of budesonide and the encapsulation of pelletized nanoparticles in a proper coating system for colon delivery that could result in a significant and long-lasting anti-inflammatory effect.

The impact of meteorological parameters on PM10 and visibility during the Middle Eastern dust storms.

Air pollution is one of the most pressing issues in populated Middle Eastern cities, in particular for the city of Ahvaz, Iran, imposing deleterious effects on the environment, public health, economy, culture, and other sectors. In this study, we investigate the relationship between meteorological parameters, PM10, AOD, air mass source origin, and visibility during severe desert dust storms (Average3h PM10 > 3200 µg m-3) between 2009 and 2012. Six of seven such events occurred between February and March. Interestingly, for the seven cases there was always an alarming PM10 mass concentration peak (137-553 µg m-3) between 12:00-18:00 (local time) that was 18-24 h before the dominant peak of the storm (3279-4899 µg m-3). The maximum wind speed over the multi-day periods examined for the dust storms is usually observed 6 h before the alarming PM10 peak. The minimum relative humidity, dew point temperature and air pressure occurred ± 3 h around the time of the alarming PM10 peak. Wind speed was the meteorological parameter that was consistently higher around the time of the first peak as compared to the second peak, with the reverse being true for sea level pressure. Based on four years of daily data in Ahvaz, PM10 was positively correlated with wind speed and air temperature and inversely correlated with sea level pressure and RH. An empirically-derived equation with R2 = 0.95 is reported to estimate the maximum PM10 concentration for severe desert dust events in the study region based on meteorological parameters. Finally, AOD is shown to correlate strongly (R2 = 0.86) with PM10 during periods with severe desert dust storms in the region.

Classification of sleep apnea using EMD-based features and PSO-trained neural networks.

In this study, we propose a method for detecting obstructive sleep apnea (OSA) based on the features extracted from empirical mode decomposition (EMD) and the neural networks trained by particle swarm optimization (PSO) in the classification phase. After extracting the features from the intrinsic mode functions (IMF) of each heart rate variability (HRV) signal of each segment, these features were applied to the input of popular classifiers such as multi-layer perceptron neural networks (MLPNN), Naïve Bayes, linear discriminant analysis (LDA), k-nearest neighborhood (KNN), and support vector machines (SVM) were applied. The results show that the MLPNN learned with back propagation (BP) algorithm has a diagnostic accuracy of less than 90%, and this may be due to being derivative based property of the BP algorithm, which causes trapping in the local minima. For Improving MLPNN's performance, we used the PSO algorithm instead of the BP method in training part. Therefore, the MLPNN's accuracy improved from 89.36 to 97.66% after the application of the PSO algorithm. The proposed method has also reached to 97.78 and 97.96% in sensitivity and specificity, respectively. So, it can be concluded that the proposed method achieves better or comparable results when compared with the previous works in this field.

A novel bio-electro-Fenton system with dual application for the catalytic degradation of tetracycline antibiotic in wastewater and bioelectricity generation.

In this new insight, the potential application of the eco-friendly Bio-Electro-Fenton (BEF) system was surveyed with the aim of simultaneous degradation of tetracycline and in situ generation of renewable bioenergy without the need for an external electricity source. To shed light on this issue, catalytic degradation of tetracycline was directly accrued via in situ generated hydroxyl free radicals from Fenton's reaction in the cathode chamber. Simultaneously, the in situ electricity generation as renewable bioenergy was carried out through microbial activities. The effects of operating parameters, such as electrical circuit conditions (in the absence and presence of external resistor load), substrate concentration (1000, 2000, 5000, and 10 000 mg L-1), catholyte pH (3, 5, and 7), and FeSO4 concentration (2, 5, and 10 mg L-1) were investigated in detail. The obtained results indicated that the tetracycline degradation was up to 99.04 ± 0.91% after 24 h under the optimal conditions (short-circuit, pH 3, FeSO4 concentration of 5 mg L-1, and substrate concentration of 2000 mg L-1). Also, the maximum removal efficiency of anodic COD (85.71 ± 1.81%) was achieved by increasing the substrate concentration up to 2000 mg L-1. However, the removal efficiencies decreased to 78.29 ± 2.68% with increasing substrate concentration up to 10 000 mg L-1. Meanwhile, the obtained maximum voltage, current density, and power density were 322 mV, 1195 mA m-2, and 141.60 mW m-2, respectively, at the substrate concentration of 10 000 mg L-1. Present results suggested that the BEF system could be employed as an energy-saving and promising technology for antibiotic-containing wastewater treatment and simultaneous sustainable bioelectricity generation.

Ladder-like targeted and gated doxorubicin delivery using bivalent aptamer in vitro and in vivo.

Regarding side effects of commonly used chemotherapeutic drugs on normal tissues, researchers introduced smart delivery and on-demand release systems. Herein, we applied a bivalent aptamer composed of ATP and AS1411 aptamers for separate targeting and gating of mesoporous silica nanoparticles in a ladder like structure with one bifunctional molecule. First part of the apatmer, AS1411, direct the delivery system to the desired site while the second part, ATP aptamer, opens the pores and release the drug just after penetrance to the cytoplasm ensuring delivery of DOX into the tumor cells. This approach faced the previous challenge of coincident targeting and gating with one aptamer. Our results demonstrated that the proposed nano-system remarkably accumulated in cancer tissue and released the drug in a sustained pattern in cancer cells. It was notably effective for inducing apoptosis in cancer cells and tumor growth inhibition without any significant side effect on normal cells and organs. Moreover, Si-cs-DOX-AAapt improved the mice survival time compared with free doxorubicin and there was no significant change in weight of mice administered with the targeted formulation. This report may open new insight for providing smart delivery systems for successful cancer treatment by introducing separate gating and targeting property by a bivalent aptamer to increase the control over drug release.

Self-assembly of an aptamer-decorated chimeric peptide nanocarrier for targeted cancer gene delivery.

In this study, we developed a peptide-based non-viral carrier decorated with aptamer to overcome the specific gene delivery barriers. The carrier (KLN/Apt) was designed to contain multiple functional segments, including 1) two tandem repeating units of low molecular weight protamine (LMWP) to condense DNA into stable nanosize particles and protect it from enzymatic digestion, 2) AS1411 aptamer as targeting moiety to target nucleolin and promote carrier internalization, 3) a synthetic pH-sensitive fusogenic peptide (KALA) for disrupting endosomal membranes and enhancing cytosol escape of the nanoparticles, and 4) a nuclear localization signal (NLS) for active cytoplasmic trafficking and nuclear delivery of DNA. The obtained results revealed the developed carrier capacity in terms of specific cell targeting, overcoming cellular gene delivery barriers, and mediating efficient gene transfection. The KLN/pDNA/aptamer nanoparticles offer remarkable potential for the conceptual design and formation of promising multi-functionalized carriers towards the most demanding therapeutic applications.