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.

A novel electrochemical aptasensor for ochratoxin a sensing in spiked food using strand-displacement polymerase reaction

Herein, an aptasensor is presented for electrochemical determination of ochratoxin A (OTA) based on nontarget-triggered production of rolling circular amplification (RCA). The surface of gold electrode is modified with thiolated complementary strand of aptamer (CS) as both capture probe and primer and OTA aptamer (Apt) as both sensing molecule and padlock probe (PLP). Following the addition of OTA, Apt/OTA conjugate is formed and detached from the electrode surface. Therefore, no RCA is produced after incubation of the modified electrode with T4 DNA ligase and phi29 DNA polymerase and a sharp current signal occurs. The analytical response ranged from 30 pM to 120 nM with detection limit of 5 pM. The designed aptasensor showed superior analytical performance in comparison with other approaches for OTA detection. Also, the approach exhibited good performance for OTA determination in spiked grape juice samples. The technique presented in this study, can be applied to develop sensors for detecting different toxins by replacing the relevant aptamers and complementary strands.

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.

Protective effect of crocin on bisphenol A - induced spatial learning and memory impairment in adult male rats: Role of oxidative stress and AMPA receptor

OBJECTIVES

Bisphenol A (BPA), a xenoestrogenic endocrine disrupting agent, is widely used in the production of polycarbonate plastics and has potential adverse effects on the developing nervous system, memory and learning abilities. The protective effect of the crocin, an important active constituent in Crocus sativus L, on memory impairment induced by BPA in rat was determined through evaluation of oxidative stress and the level of NMDA (N-methyl-D-aspartate receptors) and AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionicd acid) receptors.

MATERIALS AND METHODS

Rats were orally treated with BPA (100 mg/kg) or sesame seed oil in control group for 28 days. Crocin (10, 20, and 40 mg/kg, IP) was administrated in BPA-orally treated groups for 28 days. Memory and learning functions were evaluated by Morris water maze. The level of malondialdehyde (MDA) and glutathione (GSH) contents were determined in rat hippocampus. Additionally, the expression of NMDA and AMPA receptors were analyzed using Western blot method.

RESULTS

Administration of BPA significantly reduced memory and learning functions. Crocin significantly protected against learning and memory impairments induced by BPA. BPA administration markedly reduced GSH content and induced lipid peroxidation, while crocin was able to increase GSH content in rat hippocampus. The expression of NMDA receptor did not change in BPA-treated rats, while the significant reduction in AMPA receptor expression was observed. Moreover, crocin (20 mg/kg) significantly elevated the expression of AMPA receptor.

CONCLUSION

Crocin recovered spatial learning and memory defects induced by BPA in part through anti-oxidant activity and modulation the expression of AMPA receptor in rat hippocampus.

Targeted rod-shaped mesoporous silica nanoparticles for the co-delivery of camptothecin and survivin shRNA in to colon adenocarcinoma in vitro and in vivo

Simultaneous drug and gene delivery to cancer cells has been introduced to provide advantages of the synergistic effects of gene to sensitize the cancer cells to chemotherapeutic agent. In the current study, nucleolin-targeted co-delivery system, based on PEGylated rod-shaped mesoporous silica NPs was developed as a biocompatible nanocarrier for simultaneous delivery of camptothecin and survivin shRNA-expressing plasmid (iSur-DNA) to colon adenocarcinoma. The structural characterization including hydrodynamic radius and morphological characteristics of the prepared system demonstrated the mesoporous rod-shaped structure of the prepared system with 100-150 nm diameter. Camptothecin was loaded into the rod-shaped MSN NPs with encapsulation efficiency of 32%. At the next stage, the prepared camptothecin-loaded system was PEGylated and then iSur-DNA was condensed with C/P ratio of 6 to form PEG@MSNR-CPT/Sur. Then, the prepared camptothecin-iSur-DNA loaded PEGylated rod-shaped mesoporous silica NPs were tagged with AS1411 DNA aptamer (Apt-PEG@MSNR-CPT/Sur) in order to provide selective therapy against colorectal adenocarcinoma. The obtained results showed that the prepared platform controlled the release of anticancer drug, camptothecin. The experimental results indicated potent synergistic effect of iSur-pDNA and CPT in in vitro cytotoxicity, apoptosis induction and in vivo antitumor effect. In addition, tagging the system with AS1411 DNA aptamer facilitated drug uptake into nucleolin positive colorectal cancer cells leading to higher cellular toxicity and apoptosis induction in C26 cells compared to nucleolin-negative CHO cell line. Apt-PEG@MSNR-CPT/Sur system significantly supressed tumor growth rate in C26 tumor bearing mice while improving survival rate and pharmacokinetics of the platform in comparison with PEG@MSNR-CPT and PEG@MSNR-CPT/Sur. It could be concluded that the developed nucelolin targeted nanomedicine for co-delivery of camptothecin and iSur-DNA could serve as a versatile nanotherapeutic system against colorectal cancer.

Targeted doxorubicin-loaded mesenchymal stem cells-derived exosomes as a versatile platform for fighting against colorectal cancer

Exosomes hold great potential for cancer treatment to deliver therapeutics due to its inherent low immunogenicity. Exosomes are biocompatible cell-exocytosed secreted vesicles by most cell types, which can be used to construct novel biomanufacturing platform for drug delivery and cancer therapy. In this study, we implemented nano-sized vesicles which were secreted by mesenchymal stem cell (MSC), to encapsulate doxorubicin (DOX) through electroporation method (DOX@exosome). DOX was loaded into exosomes, with an encapsulation efficiency of up to 35% and separated by ultracentrifugation. Subsequently, carboxylic acid-end MUC1 aptamer was used to covalently decorate the surface amine groups of the exosomes via amide bond formation to provide selective guided drug delivery (DOX@exosome-apt). The data showed that the DOX@exosome-apt provided highly efficient DOX transportation to MUC1-positive cancer cells in vitro as confirmed by MTT and flow cytometry experiments. Moreover, in vivo study on ectopic model of C26 (mouse colon adenocarcinoma) in BALB/c mice indicated that the single dose intravenous injection of DOX@exosome-apt significantly suppress tumor growth in comparison with free DOX. Ex vivo fluorescent imaging also verified the desirable biodistribution of DOX@exosome-apt by exhibiting higher tumor accumulation and faster liver clearance in comparison with DOX@exosome and free DOX. It could be concluded that MUC1 aptamer-decorated exosomes can be implemented therapeutically for the safe and versatile delivery of DOX to colon adenocarcinoma, thus offering valuable platform for clinical applications.

Proteomic analysis of soluble protein extract of adult Toxocara cati

Toxocara cati is a cat roundworm and the causative agent of toxocariasis as a cosmopolitan zoonotic disease. As no information has been reported so far, identification of T. cati proteins can be useful for the development of new diagnostic strategies. This study was conducted to identify the major proteins in the adult T. cati tegument using bi-dimensional electrophoresis (2-DE) and shotgun proteomics. A total proteins were identified, among them the metabolic enzymes were the largest group, including: Enolase, triose phosphate isomerase, fructose-bisphosphate aldolase, aldehyde dehydrogenase. The other important protein groups recognized in T. cati, belong to the HSP-family, the structure and motor proteins, such as actin. The role of these proteins have been implicated in parasite-host interactions and modulating cellular immune response, immune regulation in evasion mechanisms of the host immune response. Characterizing T. cati adult proteins play a key role not only in host-parasite interactions, but also in the discovery of drug targets, subunit vaccines against toxocariasis, immunodiagnostic kits for toxocariasis and the identification of novel immuno-modulators that can form the next generation of therapeutic possibilities for inflammatory diseases.

Comparative proteomics study of proteins involved in induction of higher rates of cell death in mitoxantrone-resistant breast cancer cells MCF-7/MX exposed to TNF-α

Objective(s):

Resistance to medications is one of the main complications in chemotherapy of cancer. It has been shown that some multidrug resistant cancer cells indicate more sensitivity against cytotoxic effects of TNF-α compared to their parental cells. Our previous findings indicated vulnerability of the mitoxantrone-resistant breast cancer cells MCF-7/MX to cell death induced by TNF-α compared to the parent cells MCF-7. In this study, we performed a comparative proteomics analysis for identification of proteins involved in induction of higher susceptibility of MCF-7/MX cells to cytotoxic effect of TNF-α.

Materials and Methods:

Intensity of protein spots in 2D gel electrophoresis profiles of MCF-7 and MCF-7/MX cells were compared with Image Master Platinum 6.0 software. Selected differential protein-spots were identified with MALDI-TOF/TOF mass spectrometry and database searching. Pathway analyses of identified proteins were performed using PANTHER, KEGG PATHWAY, Gene MANIA and STRING databases. Western blot was performed for confirmation of the proteomics results.

Results:

Our results indicated that 48 hr exposure to TNF-α induced 87% death in MCF-7/MX cells compared to 19% death in MCF-7 cells. Forty landmarks per 2D gel electrophoresis were matched by Image Master Software. Six proteins were identified with mass spectrometry. Western blot showed that 14-3-3γ and p53 proteins were expressed higher in MCF-7/MX cells treated with TNF-α compared to MCF-7 cells treated with TNF-α.

Conclusion:

Our results showed that 14-3-3 γ, prohibitin, peroxiredoxin 2 and P53 proteins which were expressed differentially in MCF-7/MX cells treated with TNF-α may involve in the induction of higher rates of cell death in these cells compared to TNF-α-treated MCF-7 cells.

Mesenchymal stem cells engineered by modified polyethylenimine polymer for targeted cancer gene therapy, in vitro and in vivo

Cell-based delivery system is a promising strategy to protect therapeutic agents from the immune system and provide targeted delivery. Mesenchymal stem cells (MSCs) have recently been introduced as an encouraging vehicle in cell-based gene therapy due to their unique features including tumor-tropic property and migratory ability. However, gene transfer into MSCs is limited due to low efficiency and cytotoxicity of carriers. In this study, we designed a novel delivery system based on polyethylenimine (PEI₂₅ ) to improve these features of carrier and transfect plasmid encoding TRAIL to MSCs. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a death ligand of TNF family with selective effect on cancerous cells. Then, death induction and migration ability of TRAIL-expressing MSCs was studied in melanoma cells. The effect of engineered-MSCs as an antitumor vehicle was also investigated in mice bearing melanoma cells. Our findings indicated that heterocyclic amine derivative of PEI₂₅ showed significant improvement in MSCs viability determined by MTT assay and gene expression using fluorescent microscopy, flow cytometry, and Western blot analysis. We observed that engineered-MSCs could migrate toward and induce cell death in B16F0 cells in vitro. The single administration of TRAIL-expressing MSCs could delay tumor appearance and efficiently reduce tumor weights. Hematoxylin and eosin staining of tumor sections revealed extensive neoplastic cells necrosis. Furthermore, engineered-MSCs could migrate and localize to tumors sites within 5 days. Our results indicated that MSCs engineered by modified-PEI/TRAIL complexes could be considered as a promising cellular vehicle for targeted tumor suppression.

Combination therapy using Smac peptide and doxorubicin-encapsulated MUC 1-targeted polymeric nanoparticles to sensitize cancer cells to chemotherapy: An in vitro and in vivo study

Targeting inhibitors of apoptosis proteins (IAPs) family comprising high level expression in many cancer cells, could sensitize tumor cells to conventional chemotherapies. In the present study, we designed both doxorubicin and SmacN6 (an antagonist of the IAPs) encapsulated polymeric nanoparticles (NPs) and investigated their synergistic effect of combination therapy in vitro and in vivo. According to the results, NPs-SmacN6 significantly enhanced the cytotoxicity effect of NPs-DOX and reduced its IC₅₀ in MCF-7, 4T1 and C26 cancer cells. Western blot analysis confirmed mechanism of cell apoptosis via caspase activation through intrinsic and also extrinsic pathways. Moreover, 5TR1 aptamer-modified NPs could effectively deliver DOXor SmacN6 to C26 cancer cells (MUC1 positive) in comparison with the non-targeted one (p < 0.001). However, they could not be efficiently internalized into CHO cells (MUC1 negative), showing less cytotoxicity in this cell line. In vivo experiments in BALB/c mice bearing C26 tumor indicated that Apt-NPs-DOX in combination with Apt-NPs-SmacN6 had significant tumor growth inhibition in comparison with mice receiving either free DOX or Apt-NPs-DOX with p < 0.0001 and p < 0.05, respectively. Our results revealed that combination therapy of DOX and SmacN6 via Apt-modified nanoparticles can lead to improvement of therapeutic index of DOX in MUC1 positive cancer cells.

Therapeutic applications of AS1411 aptamer, an update review

Nucleolin or C23, is one of the most abundant non-ribosomal phosphoproteins of nucleolus. However, in several cancers, nucleolin is highly expressed both intracellularly and on the cell surface. So, it is considered as a potential target for the diagnosis and cancer therapy. Targeting nucleolin by compounds such as AS1411 aptamer can reduce tumor cell growth. In this regard, interest has increased in nucleolin as a molecular target for overcoming cancer therapy challenges. This review paper addressed recent progresses in nucleolin targeting by the G-rich AS1411 aptamer in the field of cancer therapy mainly over the past three years.

Point-of-care detection of Escherichia coli O157:H7 in water using AuNPs-based aptasensor

OBJECTIVES

Access to safe drinking and irrigation water has always been one of the major human concerns worldwide. Thus, rapid, sensitive, and inexpensive approaches for pathogenic bacteria detection, such as Escherichia coli O157:H7 (EHEC) that can induce important infectious diseases, are highly on demand.

MATERIALS AND METHODS

In this study, a sensitive aptamer-based AuNPs bioassay was developed that demonstrated its potential to detect EHEC. In the presence of the target bacterium, the specific adsorbed aptamer, leaves AuNPs surface and interacts with EHEC. The bare nanoparticles aggregate in the presence of NaCl and the color shifts from red to purple and blue depending on the bacterial concentration.

RESULTS

The proposed aptasensor exhibited a good linear response over a wide concentration range of 876 to 107 CFU/ml and was closely correlated with the line equation of "y=0.0094x+0.0006" (R2= 0.9861). It also showed a low detection limit (LOD) of 263 CFU/ml (Signal/Noise=3). No response was recorded in the presence of other tested bacterial strains including Listeria monocytogenes and Salmonella typhi, indicating the high selectivity of the aptasensor.

CONCLUSION

This biosensor may be used as a smart device to screen water reservoirs and prevents the outbreak of EHEC-related life-threatening contagious diseases.

A novel turn-off fluorescent aptasensor for ampicillin detection based on perylenetetracarboxylic acid diimide and gold nanoparticles

Herein, a novel turn-off fluorescent aptasensor was developed for selective detection of ampicillin (AMP) at picomolar level based on 3,4,9,10-perylenetetracarboxylic acid diimide (PTCDI) as an affordable and low-cost fluorophore. This aptasensor was designed using aptamer, its complementary strand (CS) and gold nanoparticles (AuNPs). The principle of the sensing method is a decrease in the fluorescence intensity of PTCDI in the presence of free CS. Following the addition of AMP, Aptamer/CS-modified AuNPs releases CS and so, the fluorescence intensity of PTCDI is reduced. The designed analytical method indicated a good linear range from 100 pM to 1000 pM and a limit of detection (LOD) of 29.2 pM was obtained. Furthermore, the sensing strategy indicated satisfactory results for the detection of AMP in the spiked human serum samples. By changing the sequences of aptamer and its CS, the presented analytical approach can be easily applied for detection of other antibiotics.

Targeted MMP-2 responsive chimeric polymersomes for therapy against colorectal cancer

In the current study, polyethylene glycol (PEG) was linked to polylactide (PLA) through the synthetic peptide PVGLIG which can be selectively cleaved by the tumor-associated matrix metalloproteinase 2 (MMP-2) enzyme. The synthesized chimeric triblock polymer of PEG-b-PVGLIG-PLA was implemented to form nanoscale self-assemble chimeric polymersomes. The hydrophobic SN38 was loaded into polymersomes with 70.3% ± 3.0% encapsulation efficiency demonstrating monodispersed spherical morphologies with 172 ± 30 nm dimension. The prepared chimeric polymersomal formulation provided controlled release of SN38 at physiological condition while illustrating seven-folds higher release rate when exposed to MMP-2 enzyme. At the next stage, AS1411 aptamer was conjugated onto the surface of MMP-2 responsive polymersomal formulation in order to provide guided drug delivery against nucleolin positive cells. In vitro cellular toxicity assay against C26 cell line (nucleolin positive) demonstrated significantly higher toxicity of targeted formulation in comparison with non-targeted one in low SN38 concentrations (0.15-1.25 μg/mL). In vivo study in mice bearing subcutaneous C26 tumor showed higher therapeutic index for MMP-2 responsive chimeric polymersomal formulation of SN38 in comparison with non-responsive one. On the other hand, AS1411 aptamer-targeted MMP-2 responsive chimeric polymersomal formulation exhibited highest therapeutic index compared to other groups. It could be concluded that the targeted chimeric polymersomes bearing both cleavable peptide sequence between their blocks and targeting ligand on their surface, provide favorable characteristics as an ideal delivery system against cancer.

Effect of Topiramate on Morphine-induced Conditioned Place Preference (CPP) in Rats: Role of ERK and CREB Proteins in Hippocampus and Cerebral Cortex

In this study, the effect of topiramate, as an antiepileptic drug, was evaluated on morphine craving in rats. The conditioned place preference (CPP) test was used for this purpose. Repeated administration of morphine (10 mg/kg, i.p. for 4 days) induced significant CPP. Administration of topiramate (50 and 100 mg/kg, i.p. for 4 days) with each morphine administration decreased the acquisition of morphine-induced CPP. At the next step, the levels of extracellular signal-regulated kinase (ERK), p-ERK, cAMP responsive element binding (CREB), and p-CREB proteins were evaluated in hippocampus and cerebral cortex using western blot analysis. Following the repeated administration of morphine, the level of p-ERK protein markedly enhanced in both tissues, while topiramate could significantly reduce the phosphorylation of ERK in these brain regions. Additionally, the level of CREB and p-CREB proteins did not change in different groups. Memantine as a positive control reduced the acquisition of morphine-induced CPP. Also, memantine significantly decreased the level of p-ERK protein in hippocampus and cerebral cortex. These results demonstrated that topiramate can attenuate the acquisition of morphine-induced CPP in rats. This effect in part can be mediated through down regulation of p-ERK protein in hippocampus and cerebral cortex.

Synthesis of multimodal polymersomes for targeted drug delivery and MR/fluorescence imaging in metastatic breast cancer model

The objective of the current study is to design and delivery of targeted PEG-PCL nanopolymersomes encapsulated with Gadolinium based Quantum Dots (QDs) and Doxorubicin (DOX) as magnetic resonance-florescence imaging and anti-cancer agent. Diagnostic and therapeutic efficiency of the prepared theranostic formulation was evaluated in vitro and in vivo. Hydrophobic QDs based on indium-copper-gadolinium-zinc sulfide were synthesized and characterized extensively. Hydrophobic QDs and hydrophilic DOX were loaded in PEG-PCL polymersomes through double emulsion method. Drug release pattern was studied in both citrate (pH 5.4) and phosphate (pH 7.4) buffer during 10 days. Both fluorescence and magnetic properties of bare QDs and prepared formulations were studied entirely. AS1411 DNA aptamer was covalently attached to the surface of polymersomal formulation in order to prepare targeted drug delivery system. Cellular cytotoxicity and cellular uptake analysis were performed in both nucleolin positive (MCF7 and 4T1) and nucleolin negative (CHO) cell lines. After in vitro evaluations, anti-tumor efficiency and diagnostic capability of the formulation was investigated in 4T1 tumor baring mice. Scanning emission electron microscopy (SEM) confirmed spherical shape and around 100 nm size of prepared formulations. Transmission electron microscopy (HRTEM) showed crystal shape of QDs with size of 2-3 nm. Drug release study obtained controlled release of encapsulated DOX and stability of formulation in physiologic condition. MTT and flow cytometry results demonstrated that AS1411 aptamer could enhance both toxicity and cellular uptake in nucleolin overexpressing cell lines (P < 0.05). Moreover, aptamer targeted formulation could increase survival rate and tumor inhibitory growth effect in 4T1 tumor baring mice (P < 0.05). Our results verify that aptamer targeted polymersomes loaded with non-toxic QDs as a diagnostic agent and DOX as an anti-cancer drug, could provide a theranostic platform with the purpose of optimization of treatment process and minimization of systemic side effects.

A smart ATP-responsive chemotherapy drug-free delivery system using a DNA nanostructure for synergistic treatment of breast cancer in vitro and in vivo

This study demonstrated a chemotherapy drug-free delivery system for breast cancer treatment based on a simple DNA nanostructure composed of sequence 1 containing ATP and AS1411 aptamers and sequence 2 containing antimiR-21. The DNA nanostructure was used for co-delivery of KLA peptide and antimiR-21 as antiapoptotic agents. These therapeutic agents could not be internalised into eukaryotic cells freely which is one of the great features of this targeting platform. The presented delivery system was ATP-responsive, leading to disassembly of the DNA nanostructure in high ATP concentration of cancer cells and restoration of the function of antimiR-21 in these cells. The DNA nanostructure was associated with high cellular uptake by MCF-7 and 4T1 cells due to expression of nucleolin as target of AS1411 on their plasma membranes, while the developed targeting platform could not be internalised into CHO cells because of lack of the active targeting moiety on their surfaces. Furthermore, the results showed that co-delivery of antimiR-21 and KLA peptide using the DNA nanostructure could efficiently prohibit tumour growth in vitro and in vivo and induce a synergistic anticancer activity. Thus, this work provides a new ATP-responsive nanotargeting delivery system and synergistic chemotherapy drug-free regimen for cancer treatment.

Design and synthesis of aptamer AS1411-conjugated EG@TiO2@Fe2O3nanoparticles as a drug delivery platform for tumor-targeted therapy

AS1411@GMBS@EG@TiO₂@Fe₂O₃nanoparticle is an effective and safe pH-responsive sustained release system for targeted drug delivery into nucleolin-positive cells.

“Smart” self-assembled structures: toward intelligent dual responsive drug delivery systems

In the current review, we summarized the polymer and peptide-based schizophrenic copolymers which could form micellar and vesicular (polymersome) systems providing novel structures with beneficial applications.