The chemotherapeutic potential of doxorubicin-loaded PEG-b-PLGA nanopolymersomes in mouse breast cancer model

Targeted doxorubicin-loaded core-shell copper peroxide-mesoporous silica nanoparticles for combination of ferroptosis and chemotherapy of metastatic breast cancer

In the current study, a tumor microenvironment responsive (TME-responsive) copper peroxide-mesoporous silica core-shell structure with H2O2 self-supplying ability was fabricated for targeted ferroptosis/chemotherapy against metastatic breast cancer. At the first stage, copper peroxide nanodot was synthesized and subsequently coated with mesoporous organosilica shell. After (3-Aminopropyl) triethoxysilane (APTMS) functionalization of the organosilica shell, doxorubicin (DOX) was loaded in the mesoporous structure of the nanoparticles and then, heterofunctional COOH-PEG-Maleimide was decorated on the surface through EDC/NHS chemistry. Afterward, thiol-functionalized AS1411 aptamer was conjugated to the maleimide groups of the PEGylated nanoparticles. In vitro study illustrated ROS generation of the system in the treated 4 T1 cell. Cellular uptake and cytotoxicity experiments showed enhanced internalization and cytotoxicity of the targeted system comparing to non-targeted one. The in vivo study on ectopic 4 T1 tumor induced in Female BALB/c mice showed ideal therapeutic effect of Apt-PEG-Silica-DOT@DOX with approximately 90 % tumor suppression in comparison with 50 % and 25 % tumor suppression for PEG-Silica-DOT@DOX and PEG-Silica-DOT. Moreover, Apt-PEG-Silica-DOT@DOX provide favorable characteristics for biosafety issues concerning the rate of survival and loss of body weight. The prepared platform could serve as a multifunctional system with smart behavior in drug release, tumor accumulation and capable for ferroptosis/chemotherapy against breast cancer.

Synthesis of folate targeted theranostic cubosomal platform for co-delivery of bismuth oxide and doxorubicin to melanoma in vitro and in vivo

Liquid crystalline nanoparticles (LCNPs) have gained much attention in cancer nanomedicines due to their unique features such as high surface area, storage stability, and sustained-release profile. In the current study, a novel LCNP for co-encapsulation of Bi2O3 and hydrophilic doxorubicin (DOX) was fabricated and functionalized with folic acid (FA) to achieve efficient tumor targeting toward CT-scan imaging and chemotherapy of melanoma in vitro and in vivo. LCNPs Bi2O3 NPs were prepared using glycerol monooleate-pluronic F-127 (GMO/PF127/water). Firstly, GMO/water were homogenized to prepare LC gel. Then, the stabilizer aqueous solution (PF127/Bi2O3/DOX) was added to the prepared LC gel and homogenized using homogenization and ultrasonication. The formulated NPs exhibited superior stability with encapsulation efficiency. High cytotoxicity and cellular internalization of the FA-Bi2O3-DOX-NPs were observed in comparison with Bi2O3-DOX-NPs and the free DOX in folate-receptor (FR) overexpressing cells (B16F10) in vitro. Moreover, ideal tumor suppression with increased survival rate were observed in tumorized mice treated with FA-Bi2O3-DOX-NPs compared to those treated with non-targeted one. On the other hand, the CT-imaging ability of the Bi2O3-DOX-NPs was tested inB16F10 tumor-bearing mice. The obtained data indicated a high potential of the developed targeted theranostic FA-Bi2O3-DOX-NPs for diagnostics and treatment of melanoma.

Therapeutic Peptides Are Preferentially Solubilized in Specific Microenvironments within PEG-PLGA Polymer Nanoparticles

Polymeric nanoparticles are a highly promising drug delivery formulation. However, a lack of understanding of the molecular mechanisms that underlie their drug solubilization and controlled release capabilities has hindered the efficient clinical translation of such technologies. Polyethylene glycol-poly(lactic-co-glycolic) acid (PEG-PLGA) nanoparticles have been widely studied as cancer drug delivery vehicles. In this letter, we use unbiased coarse-grained molecular dynamics simulations to model the self-assembly of a PEG-PLGA nanoparticle and its solubulization of the anticancer peptide, EEK, with good agreement with previously reported experimental structural data. We applied unsupervised machine learning techniques to quantify the conformations that polymers adopt at various locations within the nanoparticle. We find that the local microenvironments formed by the various polymer conformations promote preferential EEK solubilization within specific regions of the NP. This demonstrates that these microenvironments are key in controlling drug storage locations within nanoparticles, supporting the rational design of nanoparticles for therapeutic applications.

Cubosomes-assisted transdermal delivery of doxorubicin and indocyanine green for chemo-photothermal combination therapy of melanoma

Melanoma is a highly aggressive form of skin cancer with limited therapeutic options. Chemo-photothermal combination therapy has demonstrated potential for effectively treating melanoma, and transdermal administration is considered the optimal route for treating skin diseases due to its ability to bypass first-pass metabolism and enhance drug concentration. However, the stratum corneum presents a formidable challenge as a significant barrier to drug penetration in transdermal drug delivery. Lipid-nanocarriers, particularly cubosomes, have been demonstrated to possess significant potential in augmenting drug permeation across the stratum corneum. Herein, cubosomes co-loaded with doxorubicin (DOX, a chemotherapeutic drug) and indocyanine green (ICG, a photothermal agent) (DOX-ICG-cubo) transdermal drug delivery system was developed to enhance the therapeutic efficiency of melanoma by improving drug permeation. The DOX-ICG-cubo showed high encapsulation efficiency of both DOX and ICG, and exhibited good stability under physiological conditions. In addition, the unique cubic structure of the DOX-ICG-cubo was confirmed through transmission electron microscopy (TEM) images, polarizing microscopy, and small angle X-ray scattering (SAXS). The DOX-ICG-cubo presented high photothermal conversion efficiency, as well as pH and thermo-responsive DOX release. Notably, the DOX-ICG-cubo exhibited enhanced drug permeation efficiency, good biocompatibility, and improved in vivo anti-melanoma efficacy through the synergistic effects of chemo-photothermal therapy. In conclusion, DOX-ICG-cubo presented a promising strategy for melanoma treatment.

Targeted therapy of breast tumor by PLGA-based nanostructures: The versatile function in doxorubicin delivery

Breast carcinoma is a molecularly diverse illness, and it is among the most prominent and often reported malignancies in female across the globe. Surgical intervention, chemotherapy, immunotherapy, gene therapy, and endocrine treatment are among the currently viable treatment options for the carcinoma of breast. Chemotherapy is among the most prevalent cancer management strategy. Doxorubicin (DOX) widely employed as a cytostatic medication for the treatment of a variety of malignancies. Despite its widespread acceptance and excellent efficacy against an extensive line up of neoplasia, it has a variety of shortcomings that limit its therapeutic potential in the previously mentioned indications. Employment of nanoparticulate systems has come up as a unique chemo medication delivery strategy and are being considerably explored for the amelioration of breast carcinoma. Polylactic-co-glycolic acid (PLGA)-based nano systems are being utilized in a number of areas within the medical research and medication delivery constitutes one of the primary functions for PLGA given their inherent physiochemical attributes, including their aqueous solubility, biocompatibility, biodegradability, versatility in formulation, and limited toxicity. Herein along with the different application of PLGA-based nano formulations in cancer therapy, the present review intends to describe the various research investigations that have been conducted to enumerate the effectiveness of DOX-encapsulated PLGA nanoparticles (DOX-PLGA NPs) as a feasible treatment option for breast cancer.

Surface engineering of hollow gold nanoparticle with mesenchymal stem cell membrane and MUC-1 aptamer for targeted theranostic application against metastatic breast cancer

Mesenchymal stem cell membrane (MSCM)-coated biomimetic doxorubicin-loaded hollow gold nanoparticles were fabricated and decorated with MUC1 aptamer in order to provide smart theranostic platform. The prepared targeted nanoscale biomimetic platform was extensively characterized and evaluated in terms of selective delivery of DOX and CT-scan imaging. The fabricated system illustrated spherical morphology with 118 nm in diameter. Doxorubicin was loaded into the hollow gold nanoparticles through physical absorption technique with encapsulation efficiency and loading content of 77%±10 and 31%±4, respectively. The in vitro release profile demonstrated that the designed platform could respond to acidic environment, pH 5.5 and release 50% of the encapsulated doxorubicin during 48 h, while 14% of the encapsulated doxorubicin was released in physiological condition, pH 7.4 up to 48 h. The in vitro cytotoxicity experiments on 4T1 as MUC1 positive cell line illustrated that the targeted formulation could significantly increase mortality at 0.468 and 0.23 µg/ml of equivalent DOX concentration compared to non-targeted formulation while this cytotoxicity was not observed in CHO as MUC1 negative cell line. Furthermore, in vivo experiments showed high tumor accumulation of the targeted formulation even 24 h after intravenous injection which induced effective tumor growth suppression against 4T1 tumor bearing mice. On the other hand, existence of hollow gold in this platform provided CT scan imaging capability of the tumor tissue in 4T1 tumor bearing mice up to 24 h post-administration. The obtained results indicated that the designed paradigm are promising and safe theranostic system for fighting against metastatic breast cancer.

Advances in aptamer-mediated targeted delivery system for cancer treatment

Aptamers with high affinity and specificity for certain targets have rapidly become a novel class of targeted ligands applicated in drug delivery. Based on the excellent characteristics of aptamers, different aptamer-mediated drug delivery systems have been developed, including aptamer-drug conjugate (ApDC), aptamer-siRNA, and aptamer-functionalized nanoparticle systems for the effective treatment of cancer, which can reduce potential toxicity and improve therapeutic efficacy. In this review, we summarize the recent progress of aptamer-mediated delivery systems in cancer therapy, and discuss the application prospects and existing problems of innovative approaches based on aptamer therapy. Overall, this review aims to better understand the current aptamer-based targeted delivery applications through in-depth analysis to improve efficacy and develop new therapeutic methods which can ultimately improve treatment outcomes for cancer patients.

Polymersomes Based Versatile Nanoplatforms for Controlled Drug Delivery and Imaging

Drug delivery systems made based on nanotechnology represent a novel drug carrier system that can change the face of therapeutics and diagnosis. Among all the available nanoforms polymersomes have wider applications due to their unique characteristic features like drug loading carriers for both hydrophilic and hydrophobic drugs, excellent biocompatibility, biodegradability, longer shelf life in the bloodstream and ease of surface modification by ligands. Polymersomes are defined as the artificial vesicles which are enclosed in a central aqueous cavity which are composed of self-assembly with a block of amphiphilic copolymer. Various techniques like film rehydration, direct hydration, nanoprecipitation, double emulsion technique and microfluidic technique are mostly used in formulating polymersomes employing different polymers like PEO-b-PLA, poly (fumaric/sebacic acid), poly(N-isopropylacrylamide) (PNIPAM), poly (dimethylsiloxane) (PDMS), and poly(butadiene) (PBD), PTMC-b-PGA (poly (dimethyl aminoethyl methacrylate)-b-poly(l-glutamic acid)) etc. Polymersomes have been extensively considered for the conveyance of therapeutic agents for diagnosis, targeting, treatment of cancer, diabetes etc. This review focuses on a comprehensive description of polymersomes with suitable case studies under the following headings: chemical structure, polymers used in the formulation, formulation methods, characterization methods and their application in the therapeutic, and medicinal filed.

Dental plaque-inspired versatile nanosystem for caries prevention and tooth restoration

Dental caries is one of the most prevalent human diseases resulting from tooth demineralization caused by acid production of bacteria plaque. It remains challenges for current practice to specifically identify, intervene and interrupt the development of caries while restoring defects. In this study, inspired by natural dental plaque, a stimuli-responsive multidrug delivery system (PMs@NaF-SAP) has been developed to prevent tooth decay and promote enamel restoration. Classic spherical core-shell structures of micelles dual-loaded with antibacterial and restorative agents are self-assembled into bacteria-responsive multidrug delivery system based on the pH-cleavable boronate ester bond, followed by conjugation with salivary-acquired peptide (SAP) to endow the nanoparticle with strong adhesion to tooth enamel. The constructed PMs@NaF-SAP specifically adheres to tooth, identifies cariogenic conditions and intelligently releases drugs at acidic pH, thereby providing antibacterial adhesion and cariogenic biofilm resistance, and restoring the microarchitecture and mechanical properties of demineralized teeth. Topical treatment with PMs@NaF-SAP effectively diminishes the onset and severity of caries without impacting oral microbiota diversity or surrounding mucosal tissues. These findings demonstrate this novel nanotherapy has potential as a promising biomedical application for caries prevention and tooth defect restoration while resisting biofilm-associated diseases in a controlled manner activated by pathological bacteria.

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Nanomaterials can adhere to tooth and target acidic biofilms specifically.

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Application of caries prevention and tooth defect restoration.

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Guidance for the innovation of the existing post-defect restoration strategies.

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The multidrug delivery system exerts antibacterial and restorative abilities on demand.

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Bacteria-responsive system resists biofilm-associated diseases in a controlled manner.

Targeted poly(L-glutamic acid)-based hybrid peptosomes co-loaded with doxorubicin and USPIONs as a theranostic platform for metastatic breast cancer

Peptosomes, as a vesicular polypeptide-based system and a versatile carrier for co-delivery of hydrophilic and hydrophobic materials, provide great delivery opportunities due to the intrinsic biocompatibility and biodegradability of the polypeptides backbone. In the current study, a novel poly(L-glutamic acid)-block-polylactic acid di-block copolymer (PGA-PLA) was synthesized in two steps. Firstly, γ-benzyl L-glutamate-N-carboxy anhydride (BLG-NCA) and 3,6-dimethyl-1,4-dioxane-2,5-dione were polymerized using N-hexylamine and benzyl alcohol as initiators to produce poly(γ-benzyl L-glutamate (PBLG) and polylactic acid. Then, PBLG was deprotected to produce PGA. Secondly, PGA was conjugated to the benzyl-PLGA to fabricate PGA-PLA diblock copolymer. The synthesized diblock copolymer was used for the encapsulation of doxorubicin, as hydrophilic anticancer and ultra-small superparamagnetic iron oxide nanoparticles (USPIONs) as hydrophobic contrast agent within aqueous core and bilayer of vesicular peptosome, respectively via double emulsion method. The prepared peptosomes (Pep@USPIONs-DOX) controlled the release of DOX (<15 % of the encapsulated DOX release up to 240 h of incubation at the physiological conditions) while increasing the stability and solubility of the hydrophobic USPIONs. Then, AS1411 DNA aptamer was decorated on the surface of the PGA-PLA peptosomes (Apt-Pep@USPIONs-DOX). The prepared targeted and non-targeted platforms showed spherical morphology with hydrodynamic sizes of 265 ± 52 and 229 ± 44 nm respectively. In vitro cellular cytotoxicity and cellular uptake were studied in nucleolin positive (4T1) and nucleolin negative (CHO) cell lines. Cellular uptake of the targeted formulation was greater than that of non-targeted peptosome, while cellular internalization of these peptosomes was identical in CHO cells. Moreover, targeted peptosomes showed greater toxicity than non-targeted peptosome in 4T1 cell line. The prepared theranostic targeted peptosomes demonstrated improved capability in terms of survival rate, biodistribution, tumor suppression efficiency, and MR imaging in the 4T1 tumor-bearing mice.

Gliadin Nanoparticles Containing Doxorubicin Hydrochloride: Characterization and Cytotoxicity

Doxorubicin hydrochloride (DOX) is a well-known antitumor drug used as first line treatment for many types of malignancies. Despite its clinical relevance, the administration of the compound is negatively affected by dose-dependent off-target toxicity phenomena. Nanotechnology has helped to overcome these important limitations by improving the therapeutic index of the bioactive and promoting the translation of novel nanomedicines into clinical practice. Herein, nanoparticles made up of wheat gliadin and stabilized by polyoxyethylene (2) oleyl ether were investigated for the first time as carriers of DOX. The encapsulation of the compound did not significantly affect the physico-chemical features of the gliadin nanoparticles (GNPs), which evidenced a mean diameter of ~180 nm, a polydispersity index < 0.2 and a negative surface charge. The nanosystems demonstrated great stability regarding temperature (25−50 °C) and were able to retain high amounts of drug, allowing its prolonged and sustained release for up to a week. In vitro viability assay performed against breast cancer cells demonstrated that the nanoencapsulation of DOX modulated the cytotoxicity of the bioactive as a function of the incubation time with respect to the free form of the drug. The results demonstrate the potential use of GNPs as carriers of hydrophilic antitumor compounds.

Preparation of targeted theranostic red blood cell membranes-based nanobubbles for treatment of colon adenocarcinoma

OBJECTIVES

Designing and fabrication of theranostic systems based on nanoscale gaseous vesicular systems, named nanobubbles (NBs), attracted enormous interest in recent years. Biomimetic vesicular platform (V-RBC-M) can improve the pharmacokinetics of the prepared platform due to augmented circulation half-life, desirable biodegradability and biocompatibility and reduced immunogenicity.

METHODS

V-RBC-M were used for the encapsulation of lipophilic camptothecin (CPT) in the bilayer of vesicles through top-down method, followed by filling the core of V-RBC-M with inert SF6 gas to fabricate NBs with ultrasonic contrast enhancement capability (SF6-NB-CPT). In the next step, targeted NBs were formed via decoration of MUC1 aptamer on the surface of NBs (Apt-SF6-NB-CPT).

RESULTS

The designed bio-NBs indicated high encapsulation efficiency and the sustained release of CPT at pH 7.4. In vitro study demonstrated higher cellular uptake and cytotoxicity of Apt-SF6-NB-CPT compared to SF6-NB-CPT in MUC1-overexpressing cells (C26). In vivo antitumor efficacy of the prepared NBs on C26 bearing BALB/c mice showed greater therapeutic efficacy and survival rate for Apt-SF6-NB-CPT. In this regard, SF6-NB-CPT showed 58% tumor growth suppression while Apt-SF6-NB-CPT system provided 95% tumor growth suppression. Furthermore, echogenic capability of SF6-NB-CPT was demonstrated through in vitro and in vivo ultrasonic imaging.

CONCLUSIONS

Our finding demonstrated that the prepared targeted NBs are a promising theranostic platform with effective therapeutic and diagnotic potentials.

PCL-based nanoparticles for doxorubicin-ezetimibe co-delivery: A combination therapy for prostate cancer using a drug repurposing strategy

INTRODUCTION

Drug repurposing is an effective strategy for identifying the use of approved drugs for new therapeutic purposes. This strategy has received particular attention in the development of cancer chemotherapy. Considering that a growing body of evidence suggesting the cholesterol-lowering drug ezetimibe (EZ) may prevent the progression of prostate cancer, we investigated the effect of EZ alone and in combination with doxorubicin (DOX) on prostate cancer treatment.

METHODS

In this study, DOX and EZ were encapsulated within a PCL-based biodegradable nanoparticle. The physicochemical properties of drug containing nanoparticle based on PCL-PEG-PCL triblock copolymer (PCEC) have been exactly determined. The encapsulation efficiency and release behavior of DOX and EZ were also studied at two different pHs and temperatures.

RESULTS

The average size of nanoparticles (NPs) observed by field emission scanning electron microscopy (FE-SEM) was around 82±23.80 nm, 59.7±18.7 nm, and 67.6±23.8 nm for EZ@PCEC, DOX@PCEC, and DOX+EZ@PCEC NPs, respectively, which had a spherical morphology. In addition, DLS measurement showed a monomodal size distribution of around 319.9, 166.8, and 203 nm hydrodynamic diameters and negative zeta potential (-30.3, -6.14, and -43.8) mV for EZ@PCEC, DOX@PCEC, and DOX+EZ@PCEC NPs, respectively. The drugs were released from the NPs sustainably in a pH and temperature-dependent manner. Based on the MTT assay results, PCEC copolymer exhibited negligible cytotoxicity on the PC3 cell line. Therefore, PCEC was a biocompatible and suitable nano-vehicle for this study. The cytotoxicity of the DOX-EZ-loaded NPs on the PC3 cell line was higher than that of NPs loaded with single drugs. All the data confirmed the synergistic effect of EZ in combination with DOX as an anticancer drug. Furthermore, fluorescent microscopy and DAPI staining were performed to show the cellular uptake, and morphological changes-induced apoptosis of treated cells.

CONCLUSION

Overall, the data from the experiments represented the successful preparation of the nanocarriers with high encapsulation efficacy. The designed nanocarriers could serve as an ideal candidate for combination therapy of cancer. The results corroborated each other and presented successful EZ and DOX formulations containing PCEC NPs and their efficiency in treating prostate cancer.

Doxorubicin-Loaded Multivesicular Liposomes (DepoFoam) as a Sustained Release Carrier Intended for Locoregional Delivery in Cancer Treatment: Development, Characterization, and Cytotoxicity Evaluation

Background

Despite the advantages of direct intratumoral (IT) injection, the relatively rapid withdrawal of most anti-cancer drugs from the tumor due to their small molecular size limits the effectiveness of this method of administration. To address these limitations, recently, increasing attention has been directed to using slow-release biodegradable delivery systems for IT injection.

Objectives

This study aimed to develop and characterize a doxorubicin-loaded DepoFoam system as an efficient controlled-release carrier to be employed for locoregional drug delivery in cancer treatment.

Methods

Major formulation parameters, including the molar ratio of cholesterol to the main lipid [Chol/egg phosphatidylcholine (EPC)], triolein (TO) content, and lipid-to-drug molar ratio (L/D), were optimized using a two-level factorial design approach. The prepared batches were evaluated for encapsulation efficiency (EE) and percentage of drug release (DR) after 6 and 72 hours as dependent variables. The optimum formulation (named DepoDOX) was further evaluated in terms of particle size, morphology, zeta potential, stability, Fourier-transform infrared spectroscopy, in vitro cytotoxicity, and hemolysis.

Results

The analysis of factorial design indicated that TO content and L/D ratio had a negative effect on EE; between these two, TO content had the greatest effect. The TO content was also the most significant component, with a negative effect on the release rate. The ratio of Chol/EPC showed a dual effect on the DR rate. Using a higher percentage of Chol slowed down the initial release phase of the drug; nevertheless, it accelerated the DR rate in the later slow phase. DepoDOX were spherical and honeycomb-like structures (≈ 9.81 μm) with a desired sustained release profile, as DR lasted 11 days. Its biocompatibility was confirmed by the results of cytotoxicity and hemolysis assays.

Conclusions

The in vitro characterization of optimized DepoFoam formulation demonstrated its suitability for direct locoregional delivery. DepoDOX, as a biocompatible lipid-based formulation, showed appropriate particle size, high capability for encapsulating doxorubicin, superior physical stability, and a markedly prolonged DR rate. Therefore, this formulation could be considered a promising candidate for locoregional drug delivery in cancer treatment.

Synthesis of doxorubicin-loaded peptosomes hybridized with gold nanorod for targeted drug delivery and CT imaging of metastatic breast cancer

BACKGROUND

Cancer nanomedicines based on synthetic polypeptides have attracted much attention due to their superior biocompatibility and biodegradability, stimuli responsive capability through secondary conformation change, adjustable functionalities for various cargos such as peptides, proteins, nucleic acids and small therapeutic molecules. Recently, a few nanoformulations based on polypeptides comprising NK105, NC6004, NK911, CT2103, have entered phase I-III clinical trials for advanced solid tumors therapy. In the current study, we prepared polypeptide-based vesicles called peptosome via self-assembly of amphiphilic polypeptide-based PEG-PBLG diblock copolymer.

RESULTS

In this regard, poly(γ-benzyl L-glutamate (PBLG) was synthesized via ring opening polymerization (ROP) of γ-benzyl L-glutamate-N-carboxyanhydride (BLG-NCA) using N-hexylamine as initiator. Then amine-terminated PBLG was covalently conjugated to heterofuctional maleimide PEG-carboxylic acid or methyl-PEG-carboxylic acid. The PEG-PBLG peptosomes were prepared through double emulsion method for the co-delivery of doxorubicin.HCl and gold nanorods as hydrophilic and hydrophobic agents in interior compartment and membrane of peptosomes, respectively (Pep@MUA.GNR-DOX) that DOX encapsulation efficiency and loading capacity were determined 42 ± 3.6 and 1.68 ± 3.6. Then, theranostic peptosomes were decorated with thiol-functionalized EpCAM aptamer throught thiol-maleimide reaction producing Apt-Pep@MUA.GNR-DOX for targeted delivery. The non-targeted and targeted peptosomes showed 165.5 ± 1.1 and 185 ± 4.7 nm diameters, respectively while providing sustained, controlled release of DOX. Furthermore, non-targeted and targeted peptosomes showed considerable serum stability. In vitro study on MCF-7 and 4T1 cells showed significantly higher cytotoxicity for Apt-Pep@MUA.GNR-DOX in comparison with Pep@MUA.GNR-DOX while both system did not show any difference in cytotoxicity against CHO cell line. Furthermore, Apt-Pep@MUA.GNR-DOX illustrated higher cellular uptake toward EpCAM-overexpressing 4T1 cells compared to Pep@MUA.GNR-DOX. In preclinical stage, therapeutic and diagnostic capability of the prepared Pep@MUA.GNR-DOX and Apt-Pep@MUA.GNR-DOX were investigated implementing subcutaneous 4T1 tumor model in BALB/c mice. The obtained data indicated highest therapeutic index for Apt-Pep@MUA.GNR-DOX compared to Pep@MUA.GNR-DOX and free DOX. Moreover, the prepared system showed capability of CT imaging of tumor tissue in 4T1 tumorized mice through tumor accumulation even 24 h post-administration.

CONCLUSION

In this regard, the synthesized theranostic peptosomes offer innovative hybrid multipurpose platform for fighting against breast cancer.

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.

PLGA's Plight and the Role of Stealth Surface Modification Strategies in Its Use for Intravenous Particulate Drug Delivery

Numerous human disorders can benefit from targeted, intravenous (IV) drug delivery. Polymeric nanoparticles have been designed to undergo systemic circulation and deliver their therapeutic cargo to target sites in a controlled manner. Poly(lactic-co-glycolic) acid (PLGA) is a particularly promising biomaterial for designing intravenous drug carriers due to its biocompatibility, biodegradability, and history of clinical success across other routes of administration. Despite these merits, PLGA remains markedly absent in clinically approved IV drug delivery formulations. A prominent factor in PLGA particles' inability to succeed intravenously may lie in the hydrophobic character of the polyester, leading to the adsorption of serum proteins (i.e., opsonization) and a cascade of events that end in their premature clearance from the bloodstream. PEGylation, or surface-attached polyethylene glycol chains, is a common strategy for shielding particles from opsonization. Polyethylene glycol (PEG) continues to be regarded as the ultimate "stealth" solution despite the lack of clinical progress of PEGylated PLGA carriers. This review reflects on some of the reasons for the clinical failure of PLGA, particularly the drawbacks of PEGylation, and highlights alternative surface coatings on PLGA particles. Ultimately, a new approach will be needed to harness the potential of PLGA nanoparticles and allow their widespread clinical adoption.

Photothermal MnO2 nanoparticles boost chemo-photothermal therapy-induced immunogenic cell death in tumor immunotherapy

The induction of immunogenic cell death (ICD) is an attractive strategy for generating in situ autologous tumor cell-based vaccines and thus has great potential in cancer prevention and personalized immunotherapy. However, the effectiveness of ICD in tumor immunotherapy has been greatly limited, mainly by low induction efficiency and the immunosuppressive tumor microenvironment (TME). Herein, we report a new strategy for chemo-photothermal therapy-induced ICD by employing photothermal MnO₂ nanoparticles loaded with doxorubicin (DOX) in tumor immunotherapy to overcome the low efficiency of traditional ICD inducers and the immunosuppressive TME. Specifically, we prepared photothermal bovine serum albumin (BSA)-templated MnO₂ NPs (BSA/MnO₂ NPs) with good aqueous dispersibility and high biocompatibility through the direct reduction of KMnO₄ with BSA, and we then efficiently loaded DOX, an ICD inducer, onto the MnO₂ NPs through coordination (DOX-BSA/MnO₂ NPs). The DOX-BSA/MnO₂ NPs achieved high photothermal conversion efficiency, highly efficient tumor targeting, TME-responsive DOX release and modulation of the hypoxic TME. Notably, a marked in vivo synergistic therapeutic effect was achieved in a triple-negative breast carcinoma-bearing mouse model by combining chemo-photothermal therapy-induced ICD with amelioration of the immunosuppressive TME. Our research highlights the great promise of modulating the TME with photothermal MnO₂ nanosystems to enhance ICD-induced antitumor immunotherapy.

Current understandings and clinical translation of nanomedicines for breast cancer therapy

Breast cancer is one of the most frequently diagnosed cancers that is threatening women's life. Current clinical treatment regimens for breast cancer often involve neoadjuvant and adjuvant systemic therapies, which somewhat are associated with unfavorable features. Also, the heterogeneous nature of breast cancers requires precision medicine that cannot be fulfilled by a single type of systemically administered drug. Taking advantage of the nanocarriers, nanomedicines emerge as promising therapeutic agents for breast cancer that could resolve the defects of drugs and achieve precise drug delivery to almost all sites of primary and metastatic breast tumors (e.g. tumor vasculature, tumor stroma components, breast cancer cells, and some immune cells). Seven nanomedicines as represented by Doxil® have been approved for breast cancer clinical treatment so far. More nanomedicines including both non-targeting and active targeting nanomedicines are being evaluated in the clinical trials. However, we have to realize that the translation of nanomedicines, particularly the active targeting nanomedicines is not as successful as people have expected. This review provides a comprehensive landscape of the nanomedicines for breast cancer treatment, from laboratory investigations to clinical applications. We also highlight the key advances in the understanding of the biological fate and the targeting strategies of breast cancer nanomedicine and the implications to clinical translation.

Multiple targeted doxorubicin-lonidamine liposomes modified with p-hydroxybenzoic acid and triphenylphosphonium to synergistically treat glioma

A type of pH-sensitive multi-targeted brain tumor site-specific liposomes (Lip-CTPP) co-modified with p-hydroxybenzoic acid (p-HA) and triphenylphosphonium (TPP) were designed and prepared to co-load doxorubicin (DOX) and lonidamine (LND). Lip-CTPP are promising potential carriers to exert the anti-glioma effect of DOX and LND collaboratively given the following features: 1) Lip-CTPP have a good pharmacokinetic behavior; 2) Lip-CTPP can cross the blood-brain barrier (BBB) and recognize tumor cells through the affinity of p-HA and dopamine/sigma receptors; 3) Lip-CTPP are highly positive charged once the acid-sensitive amide bonds are cleaved in endo/lysosomes to expose TPP and protonate amine groups; 4) the positive charged Lip-CTPP escape from endo/lysosomes and accumulate in mitochondria through electrostatic adsorption; 5) DOX and LND are released and synergistically increase anti-tumor efficacy. Our in vitro and in vivo results confirmed that Lip-CTPP could greatly elevate the inhibition rate of tumor cell proliferation, migration and invasion, promote apoptosis and necrosis, and interfere with mitochondrial function. In addition, Lip-CTPP could significantly prolong the survival time of glioma bearing mice, narrow the tumor region and inhibit the infiltration and metastasis capability of glioma cells. Collectively, Lip-CTPP are promising nano formulations to enhance the synergistic effect of DOX and LND in glioma treatment.

Promotion of angiogenesis toward transplanted ovaries using nitric oxide releasing nanoparticles in fibrin hydrogel

Transplantation of ovary is one method of facilitating fertility preservation to increase the quality of life of cancer survivors. Immediately after transplantation, ovaries are under ischemic conditions owing to a lack of vascular anastomosis between the graft and host tissues. The transplanted ovaries can suffer damage because of lack of oxygen and nutrients, resulting in necrosis and dysfunction. In the technique proposed in this paper, the ovary is encapsulated with nitric oxide-releasing nanoparticles (NO-NPs) in fibrin hydrogels, which form a carrying matrix to prevent ischemic damage and accelerate angiogenesis. The low concentration of NO released from mPEG-PLGA nanoparticles elicits blood vessel formation, which allows transplanted ovaries in the subcutis to recover from the ischemic period. In experiments with mice, the NO-NPs/fibrin hydrogel improved the total number and quality of ovarian follicles after transplantation. The intra-ovarian vascular density was 4.78 folds higher for the NO-NPs/fibrin hydrogel groups compared to that for the nontreated groups. Finally,in vitrofertilization revealed a successful blastocyst formation rate for NO-NPs/fibrin hydrogel coated ovaries. Thus, NO-NPs/fibrin hydrogels can provide an appropriate milieu to promote angiogenesis and be considered as adjuvant surgery materials for fertility preservation.

Self-targeted polymersomal co-formulation of doxorubicin, camptothecin and FOXM1 aptamer for efficient treatment of non-small cell lung cancer

In spite of huge developments in cancer treatment, versatile combinational formulations of different chemotherapeutic agents to enhance anticancer activity while reducing systemic toxicity still remains a challenge. In this regard, in the current study, an amphiphilic hyaluronic acid-b-polycaprolactone diblock copolymer was synthesized using "click chemistry". The synthesized copolymer was self-assembled to form polymersomal structures for co-encapsulation of hydrophilic doxorubicin (DOX) and hydrophobic camptothecin (CPT) in their interior aqueous compartment and their bilayer, respectively with 1:10 and 1:1 ratios. The prepared polymersomal combinational formulation surrounded by hyaluronic acid brush as hydrophilic segment, could provide active targeting of the system against CD44 marker expressed on the surface of cancerous cells. The hyaluronic acid shell could also provide flexible chemistry for the conjugation of therapeutic FOXM1-specific DNA aptamer (Forkhead Box M1; against transcription factor FOXM1) on the surface of polymersomes in order to further suppress cancerous cell proliferation. The obtained results demonstrated that the prepared co-formulation provided sustained, controlled release of the entrapped drugs during 200 h. In vitro cytotoxicity experiments on non-small cell lung cancer, A549 and SK-MES-1 cell lines, demonstrated that the co-formulation of DOX and CPT provided synergistic effect and significantly higher cytotoxicity in comparison with free drugs. The cytotoxicity experiment also indicated that the aptamer conjugation on the co-formulations surface could significantly increase the cytotoxicity and induce apoptosis in combination therapy on both A549 and SK-MES-1 cell lines while aptamer-conjugated blank NPs did not show any cytotoxicity which emphasizes on the sensitization capability of the FOXM1 DNA aptamer against non-small cell lung cancer. Furthermore, it was shown that the co-formulation with or without aptamer renders the formulation specific tumor accumulation in vivo 24 h post-administration, assisting the combination synergy observed in vitro to be translated to in vivo antitumor efficacy. This combinatorial delivery platform strongly offers a novel approach for the synergistic controlled transportation of several chemotherapeutics for the treatment of non-small cell lung cancer.

Multifunctional PLGA nanoparticles combining transferrin-targetability and pH-stimuli sensitivity enhanced doxorubicin intracellular delivery and in vitro antineoplastic activity in MDR tumor cells

Targeted delivery aims to enhance cellular uptake and improve therapeutic outcome with higher disease specificity. The expression of transferrin receptor (TfR) is upregulated on tumor cells, which make the protein Tf and its receptor vastly relevant when applied to targeting strategies. Here, we proposed Tf-decorated pH-sensitive PLGA nanoparticles containing the chemosensitizer poloxamer as a carrier for doxorubicin delivery to tumor cells (Tf-DOX-PLGA-NPs), aiming at alleviating multidrug resistance (MDR). We performed a range of in vitro studies to assess whether targeted NPs have the ability to improve DOX antitumor potential on resistant NCI/ADR-RES cells. All evaluations of the Tf-decorated NPs were performed comparatively to the nontargeted counterparts, aiming to evidence the real role of NP surface functionalization, along with the benefits of pH-sensitivity and poloxamer, in the improvement of antiproliferative activity and reversal of MDR. Tf-DOX-PLGA-NPs induced higher number of apoptotic events and ROS generation, along with cell cycle arrest. Moreover, they were efficiently internalized by NCI/ADR-RES cells, increasing DOX intracellular accumulation, which supports the greater cell killing ability of these targeted NPs with respect to MDR cells. Altogether, these findings supported the effectiveness of the Tf-surface modification of DOX-PLGA-NPs for an improved antiproliferative activity. Therefore, our pH-responsive Tf-inspired NPs are a promising smart drug delivery system to overcome MDR effect at some extent, enhancing the efficacy of DOX antitumor therapy.

PEGylated-PLGA Nanoparticles Coated with pH-Responsive Tannic Acid-Fe(III) Complexes for Reduced Premature Doxorubicin Release and Enhanced Targeting in Breast Cancer

Biodegradable poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) have been widely used as delivery vehicles for chemotherapy drugs. However, premature drug release in PLGA NPs can damage healthy tissue and cause serious adverse effects during systemic administration. Here, we report a tannic acid-Fe(III) (Fe^III-TA) complex-modified PLGA nanoparticle platform (DOX-TPLGA NPs) for the tumor-targeted delivery of doxorubicin (DOX). A PEGylated-PLGA inner core and Fe^III-TA complex outer shell were simultaneously introduced to reduce premature drug release in blood circulation and increase pH-triggered drug release in tumor tissue. Compared to the unmodified NPs, the initial burst rate of DOX-TPLGA NPs was significantly reduced by nearly 2-fold at pH 7.4. Moreover, the cumulative drug release rate at pH 5.0 was 40% greater than that at pH 7.4 due to the pH-response of the Fe^III-TA complex. Cellular studies revealed that the TPLGA NPs had enhanced drug uptake and superior cytotoxicity of breast cancer cells in comparison to free DOX. Additionally, the DOX-TPLGA NPs efficiently accumulated in the tumor site of 4T1-bearing nude mice due to the enhanced permeability and retention (EPR) effect and reached a tumor inhibition rate of 85.53 ± 8.77% (1.31-fold versus DOX-PLGA NPs and 3.12-fold versus free DOX). Consequently, the novel TPLGA NPs represent a promising delivery platform to enhance the safety and efficacy of chemotherapy drugs.

Targeted drug delivery strategies for precision medicines

Progress in the field of precision medicine has changed the landscape of cancer therapy. Precision medicine is propelled by technologies that enable molecular profiling, genomic analysis, and optimized drug design to tailor treatments for individual patients. Although precision medicines have resulted in some clinical successes, the use of many potential therapeutics has been hindered by pharmacological issues, including toxicities and drug resistance. Drug delivery materials and approaches have now advanced to a point where they can enable the modulation of a drug's pharmacological parameters without compromising the desired effect on molecular targets. Specifically, they can modulate a drug's pharmacokinetics, stability, absorption, and exposure to tumours and healthy tissues, and facilitate the administration of synergistic drug combinations. This Review highlights recent progress in precision therapeutics and drug delivery, and identifies opportunities for strategies to improve the therapeutic index of cancer drugs, and consequently, clinical outcomes.

Combination Therapy of Breast Cancer by Codelivery of Doxorubicin and Survivin siRNA Using Polyethylenimine Modified Silk Fibroin Nanoparticles

Here, polyethylenimine (PEI) modified silk fibroin nanoparticles (SFNPs) were prepared for codelivery of doxorubicin (DOX) and survivin siRNA. The prepared NPs were characterized in terms of stability and structural, functional, and physicochemical properties. Moreover, the ability of the conjugate to escape from the endosome and cellular uptake were assessed. Afterward, the in vivo therapeutic efficacy was analyzed in the mice model. The siRNA loaded PEI-SFNPs showed acceptable size, zeta potential, and stability in serum. It also effectively induced apoptosis in the 4T1 mouse mammary tumor cell line. Cellular uptake and endosomal escape analyses confirmed that PEI-SFNPs containing siRNA could escape from the endosome and accumulate in the cytoplasm of 4T1 cells. Real time-PCR indicated the significant decrease in the expression of survivin mRNA in the 4T1 cell line 48 h postincubation with siRNA loaded PEI-SFNPs. In vivo biodistribution of PEI-SFNPs confirmed higher accumulation of SFNPs in the tumor site compared with other organs. The codelivery systems remarkably reduced the growth rate of breast tumor in the mice model without any obvious weight lost. Histopathological and tunnel staining exhibited more apoptotic tumor cells in the group containing both DOX and survivin siRNA. Tumorigenic breast tissue resected from the animals after treatment with siRNA also exhibited significant suppression of survivin gene. In conclusion, the prepared drug delivery system had an acceptable potential in tumor removal, apoptosis induction in cancer cells, and therapeutic efficacy. Thus, it would be a good candidate for breast cancer therapy.

Silencing of HIF-1α/CD73 axis by siRNA-loaded TAT-chitosan-spion nanoparticles robustly blocks cancer cell progression

Induction of Hypoxia Inducible Factor (HIF) as a direct consequence of oxygen deficiency in tumor tissues is a potent stimulus of CD73 (ecto-5'-nucleotidase) expression. Hypoxic environment and CD73 overexpression are associated with altered metabolism, elevated cancer cell proliferation, and tumor vascularization. Herein, a delivery system was developed for silencing CD73 and HIF-1α gene using siRNA-loaded Superparamagnetic iron oxide (SPION) nanocarriers for cancer treatment. SPIONs were encapsulated with thiolated chitosan (TC) and trimethyl chitosan (TMC) for improving their stabilization and functionalization. The nanoparticles (NPs) were about 133 nm in size, spherical, and non-toxic, and the addition of TAT peptide (derived from HIV-1 TAT protein) to TMC-TC-SPIONs significantly increased their cellular uptake by cancer cells. The produced NPs could efficiently accumulate in the tumor site, indicating their stability and targeting ability in reaching the tumor region. TAT-conjugated TMC-TC-SPIONs containing siRNAs could significantly reduce the HIF-1α and CD73 expression levels in cancer cells. Following transfection, cancer cells showed a significant reduction in migration and proliferation. Moreover, siRNA-loaded NPs could effectively reduce tumor growth and angiogenesis, as investigated by the chick chorioallantoic membrane (CAM) assay. This study suggested that TAT-TMC-TC-SPIONs can be potential nanocarrier for gene transfection in cancer therapy. Moreover, the co-silencing of CD73 and HIF-1α can be assumed as a novel anti-cancer treatment strategy with high tumor suppression potential.

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.

Meta-Analysis of Nanoparticle Delivery to Tumors Using a Physiologically Based Pharmacokinetic Modeling and Simulation Approach

Numerous studies have engineered nanoparticles with different physicochemical properties to enhance the delivery efficiency to solid tumors, yet the mean and median delivery efficiencies are only 1.48% and 0.70% of the injected dose (%ID), respectively, according to a study using a nonphysiologically based modeling approach based on published data from 2005 to 2015. In this study, we used physiologically based pharmacokinetic (PBPK) models to analyze 376 data sets covering a wide range of nanomedicines published from 2005 to 2018 and found mean and median delivery efficiencies at the last sampling time point of 2.23% and 0.76%ID, respectively. Also, the mean and median delivery efficiencies were 2.24% and 0.76%ID at 24 h and were decreased to 1.23% and 0.35%ID at 168 h, respectively, after intravenous administration. While these delivery efficiencies appear to be higher than previous findings, they are still quite low and represent a critical barrier in the clinical translation of nanomedicines. We explored the potential causes of this poor delivery efficiency using the more mechanistic PBPK perspective applied to a subset of gold nanoparticles and found that low delivery efficiency was associated with low distribution and permeability coefficients at the tumor site (P < 0.01). We also demonstrate how PBPK modeling and simulation can be used as an effective tool to investigate tumor delivery efficiency of nanomedicines.

Progress in Polymeric Nano-Medicines for Theranostic Cancer Treatment

Cancer is a life-threatening disease killing millions of people globally. Among various medical treatments, nano-medicines are gaining importance continuously. Many nanocarriers have been developed for treatment, but polymerically-based ones are acquiring importance due to their targeting capabilities, biodegradability, biocompatibility, capacity for drug loading and long blood circulation time. The present article describes progress in polymeric nano-medicines for theranostic cancer treatment, which includes cancer diagnosis and treatment in a single dosage form. The article covers the applications of natural and synthetic polymers in cancer diagnosis and treatment. Efforts were also made to discuss the merits and demerits of such polymers; the status of approved nano-medicines; and future perspectives.

“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.

Incorporation of doxorubicin in different polymer nanoparticles and their anticancer activity

Background: Nanoparticles are under investigation as carrier systems for anticancer drugs. The expression of efflux transporters such as the ATP-binding cassette (ABC) transporter ABCB1 is an important resistance mechanism in therapy-refractory cancer cells. Drug encapsulation into nanoparticles has been shown to bypass efflux-mediated drug resistance, but there are also conflicting results. To investigate whether easy-to-prepare nanoparticles made of well-tolerated polymers may circumvent transporter-mediated drug efflux, we prepared poly(lactic-co-glycolic acid) (PLGA), polylactic acid (PLA), and PEGylated PLGA (PLGA-PEG) nanoparticles loaded with the ABCB1 substrate doxorubicin by solvent displacement and emulsion diffusion approaches and assessed their anticancer efficiency in neuroblastoma cells, including ABCB1-expressing cell lines, in comparison to doxorubicin solution. Results: The resulting nanoparticles covered a size range between 73 and 246 nm. PLGA-PEG nanoparticle preparation by solvent displacement led to the smallest nanoparticles. In PLGA nanoparticles, the drug load could be optimised using solvent displacement at pH 7 reaching 53 µg doxorubicin/mg nanoparticle. These PLGA nanoparticles displayed sustained doxorubicin release kinetics compared to the more burst-like kinetics of the other preparations. In neuroblastoma cells, doxorubicin-loaded PLGA-PEG nanoparticles (presumably due to their small size) and PLGA nanoparticles prepared by solvent displacement at pH 7 (presumably due to their high drug load and superior drug release kinetics) exerted the strongest anticancer effects. However, nanoparticle-encapsulated doxorubicin did not display increased efficacy in ABCB1-expressing cells relative to doxorubicin solution. Conclusion: Doxorubicin-loaded nanoparticles made by different methods from different materials displayed substantial discrepancies in their anticancer activity at the cellular level. Optimised preparation methods resulted in PLGA nanoparticles characterised by increased drug load, controlled drug release, and high anticancer efficacy. The design of drug-loaded nanoparticles with optimised anticancer activity at the cellular level is an important step in the development of improved nanoparticle preparations for anticancer therapy. Further research is required to understand under which circumstances nanoparticles can be used to overcome efflux-mediated resistance in cancer cells.

Co-delivery of doxorubicin and TRAIL plasmid by modified PAMAM dendrimer in colon cancer cells, in vitro and in vivo evaluation

One strategy for cancer treatment is combination therapy using nanoparticles (NPs), which has resulted in enhanced anti-cancer effects and reduced cytotoxicity of therapeutic agents. Polyamidoamine dendrimer (PAMAM) has attracted considerable attention because of its potential applications ranging from drug delivery to molecular encapsulation and gene therapy. In this study, PAMAM G5 modified with cholesteryl chloroformate and alkyl-PEG was applied for co-delivery of doxorubicin (DOX) and plasmid encoding TRAIL into colon cancer cells, in vitro and in vivo. The results showed DOX was efficiently encapsulated in modified carrier (M-PAMAM) with loading level about 90%, and the resulting DOX-loaded M-PAMAM complexed with TRAIL plasmid showed much stronger antitumor effect than M-PAMAM containing DOX or TRAIL plasmid. On the other hand, the obtained results demonstrated that the treatment of mice bearing C26 colon carcinoma with this developed co-delivery system significantly decreased tumor growth rate. Thus, this modified PAMAM G5 can be considered as a potential carrier for co-delivery of drug and gene in cancer therapy.

Enzyme responsive drug delivery systems in cancer treatment

Recent technological approaches in drug delivery have attracted scientist interest for improving therapeutic index of medicines and drug compliance. One of the powerful strategies to control the transportation of drugs is implementation of intelligent stimuli-responsive drug delivery system (DDS). In this regard, tumor tissues with unique characteristics including leaky vasculature and diverse enzyme expression profiles facilitate the development of efficient enzyme-responsive nanoscale delivery systems. Based on the stimuli nature (physical, chemical and biological), these systems can be categorized into three groups according to the nature of trigger initiating the drug release. Enzymes are substantial constituents of the biotechnology toolbox offering promising capabilities and ideal characteristics to accelerate chemical reactions. Nanoparticles which have the ability to trigger their cargo release in the presence of specific enzymes are fabricated implementing fascinating physico-chemical properties of different materials in a nanoscale dimension. In order to reduce the adverse effects of the therapeutic agents, nanocarriers can be utilized and modified with enzyme-labile linkages to provide on-demand enzyme-responsive drug release. In the current review, we give an overview of drug delivery systems which can deliver drugs to the tumor microenvironment and initiate the drug release in response to specific enzymes highly expressed in particular tumor tissues. This strategy offers a versatile platform for intelligent drug release at the site of action.

Enhanced efficacy of baicalin-loaded TPGS polymeric micelles against periodontitis

As a chronic infectious disease, periodontitis is the main cause of teeth exfoliation due to its severe inflammatory reaction and periodontal tissue destruction. Recent reports have shown that baicalin could inhibit the NF-κB signaling pathway in inflammatory activity of periodontitis, but the efficacy of baicalin is limited due to its poor water solubility. In this work, we report the fabrication and application of baicalin encapsulated D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) polymeric micelles (PMs) through thin-film hydration method. The monodispersed micelles showed a spherical shape in aqueous solution and a prolonged drug-release kinetic. After baicalin was loaded into PMs, cytotoxicity and apoptosis induction were both decreased. The expression of genes (including TNF-α, IL-1β, RANKL and NF-κB) and the phosphorylation level of NF-κB p65 protein in lipopolysaccharide (LPS)-induced rat gingival fibroblasts were also reduced. Further investigation of drug efficacy in a rat periodontal disease model confirmed that the use of baicalin-PMs could reduce the destruction of alveolar bone and gingival fiber. Moreover, the therapeutic effect of baicalin-PMs was significantly better than that of free baicalin. These results suggest that the direct injection of micelles containing water-insoluble drugs may become a simple but effective method for treating periodontitis.

Targeted Nanomedicine to Treat Bone Metastasis

Bone metastases are common complications of solid tumors, particularly those of the prostate, breast, and lungs. Bone metastases can lead to painful and devastating skeletal-related events (SREs), such as pathological fractures and nerve compressions. Despite advances in treatment for cancers in general, options for bone metastases remain inadequate and generally palliative. Anticancer drugs (chemotherapy and radiopharmaceuticals) do not achieve therapeutic concentrations in the bone and are associated with dose-limiting side effects to healthy tissues. Nanomedicines, with their tunable characteristics, have the potential to improve drug targeting to bone metastases while decreasing side effects for their effective treatment. In this review, we present the current state of the art for nanomedicines to treat bone metastases. We also discuss new treatment modalities enhanced by nanomedicine and their effects on SREs and disease progression.

Free Adriamycin-Loaded pH/Reduction Dual-Responsive Hyaluronic Acid-Adriamycin Prodrug Micelles for Efficient Cancer Therapy

Currently, tumor-targeted nanocarriers self-assembled from amphiphilic polymer-drug conjugates are of great demand. The appeal of these carriers arises mainly through their excellent loading efficiency of homologous drug molecules with microenvironment-triggered drug release. Herein, doxorubicin (DOX) was constructed to a hyaluronic acid (HA) backbone through hydrazone and disulfide linkages to construct pH and reduction coresponsive prodrug conjugates (HA-ss-DOX). During formulation, the amphipathic HA-ss-DOX spontaneously assembled into distinct core/shell micelles in aqueous media and showed conspicuous physical DOX loading capabilities (29.1%, DOX/HA-ss-DOX) based on homologous compatibility. DOX/HA-ss-DOX micelles were shown to be stable in normal physiological environments, while accomplishing selective, rapid DOX release at acidic pH and/or highly reducing conditions. The efficacy of DOX/HA-ss-DOX micelles was tested on A549 human lung cancer cells, wherein flow cytometry and confocal microscopy analysis revealed their HA receptor-mediated endocytosis mechanism. In comparison, DOX-loaded redox-insensitive micelles (DOX/HA-DOX) still demonstrated pH-dependent drug release. However, a more rapid intracellular DOX release profile was achieved in DOX/HA-ss-DOX micelles because of their sensitivity to both acidic and reducing environments. Resultantly, DOX/HA-ss-DOX exhibited the strongest cytotoxicity and apoptosis-inducing ability among all tested groups when tested on an A549 cell line and xenograft model.

Inducing angiogenesis with the controlled release of nitric oxide from biodegradable and biocompatible copolymeric nanoparticles

PURPOSE

Nitric oxide (NO) can be clinically applied at low concentrations to regulate angiogenesis. However, studies using small molecule NO donors (N-diazeniumdiolate, S-nitrosothiol, etc) have yet to meet clinical requirements due to the short half-life and initial burst-release profile of NO donors. In this study, we report the feasibility of methoxy poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles (NPs) as NO-releasing polymers (NO-NPs) for inducing angiogenesis.

MATERIALS AND METHODS

The mPEG-PLGA copolymers were synthesized by typical ring-opening polymerization of lactide, glycolide and mPEG as macroinitiators. Double emulsion methods were used to prepare mPEG-PLGA NPs incorporating hydrophilic NONOate (dieth-ylenetriamine NONOate).

RESULTS

This liposomal NP encapsulates hydrophilic diethylenetriamine NONOate (70%±4%) more effectively than other previously reported materials. The application of NO-NPs at different ratios resulted in varying NO-release profiles with no significant cytotoxicity in various cell types: normal cells (fibroblasts, human umbilical vein endothelial cells and epithelial cells) and cancer cells (C6, A549 and MCF-7). The angiogenic potential of NO-NPs was confirmed in vitro by tube formation and ex vivo through an aorta ring assay. Tubular formation increased 189.8% in NO-NP-treated groups compared with that in the control group. Rat aorta exhibited robust sprouting angiogenesis in response to NO-NPs, indicating that NO was produced by polymeric NPs in a sustained manner.

CONCLUSION

These findings provide initial results for an angiogenesis-related drug development platform by a straightforward method with biocompatible polymers.

Curcumin-entrapped MUC-1 aptamer targeted dendrimer-gold hybrid nanostructure as a theranostic system for colon adenocarcinoma

Gold NPs have great potential in biomedical applications. PAMAM dendrimers are spherical, hyper branched macromolecules which can encapsulate therapeutic molecules while stabilizing metal nanoparticle such as gold NPs. The aim of the current study was to investigate the theranostic capability of curcumin-loaded dendrimer-gold hybrid structure. Dendrimer-gold hybrid structure was synthesized by complexing AuCl₄^- ions with PEGylated amine-terminated generation 5 poly (amidoamine) dendrimer. The resultant hybrid system was loaded with curcumin. The curcumin-loaded PEGylated Au dendrimer was further conjugated to MUC-1 aptamer in order to target the colorectal adenocarcinoma in vitro and in vivo. Obtained results demonstrated that the targeted theranostic agent was accumulated in HT29 and C26 cells in vitro and showed higher cellular cytotoxicity in comparison with non-targeted system. On the other hand, in vivo experiment demonstrated the potential of targeted theranostic system in CT-scan tumor imaging as well as cancer therapy. Findings from this study suggested that MUC-1 targeted curcumin-loaded PEGylated Au dendrimers have good X-ray attenuation and is desirable probe for CT imaging while demonstrating high therapeutic index against colorectal cancer adenocarcinoma.

Theranostic niosomes for direct intratumoral injection: marked enhancement in tumor retention and anticancer efficacy

AIM

For simultaneous bioimaging and drug delivery via direct intratumoral injection, doxorubicin and Ag₂S quantum dots co-loaded multifunctional niosomes were prepared and fully characterized.

MATERIALS & METHODS

Various theranostic niosomes were prepared and investigated regarding cytotoxicity, in vivo imaging, drug accumulation in breast cancer tumor and antitumor activity.

RESULTS

Niosomes composed of Tween-60, Tween-80 or Span 60 produced strong and more durable detectable fluorescence signals. Despite a higher accumulation of Tween-60 niosomes in tumor, the Span 60 formulation showed the highest antitumor efficacy when compared with the free drug (71.7 and 20.3% inhibition in tumor growth, respectively).

CONCLUSION

Direct intratumoral injection of theranostic niosomes with appropriate composition could be a powerful tool for combined multimodal imaging and therapy.

A Novel AS1411 Aptamer-Based Three-Way Junction Pocket DNA Nanostructure Loaded with Doxorubicin for Targeting Cancer Cells in Vitro and in Vivo

Active targeting of nanostructures containing chemotherapeutic agents can improve cancer treatment. Here, a three-way junction pocket DNA nanostructure was developed for efficient doxorubicin (Dox) delivery into cancer cells. The three-way junction pocket DNA nanostructure is composed of three strands of AS1411 aptamer as both a therapeutic aptamer and nucleolin target, the potential biomarker of prostate (PC-3 cells) and breast (4T1 cells) cancers. The properties of the Dox-loaded three-way junction pocket DNA nanostructure were characterized and verified to have several advantages, including high serum stability and a pH-responsive property. Cellular uptake studies showed that the Dox-loaded DNA nanostructure was preferably internalized into target cancer cells (PC-3 and 4T1 cells). MTT cell viability assay demonstrated that the Dox-loaded DNA nanostructure had significantly higher cytotoxicity for PC-3 and 4T1 cells compared to that of nontarget cells (CHO cells, Chinese hamster ovary cell). The in vivo antitumor effect showed that the Dox-loaded DNA nanostructure was more effective in prohibition of the tumor growth compared to free Dox. These findings showed that the Dox-loaded three-way junction pocket DNA nanostructure could significantly reduce the cytotoxic effects of Dox against nontarget cells.

Design of pH-Sensitive Nanovesicles via Cholesterol Analogue Incorporation for Improving in Vivo Delivery of Chemotherapeutics

pH-responsive polymersomes have emerged as promising nanocarriers for antitumor drugs to realize their fast release and action in a weakly acidic microenvironment of tumor cells. Herein, however, we designed a remarkably pH-responsive polymersome self-assembled from amphiphilic benzimidazole-based polyphosphazenes via the incorporation of cholesteryl hemisuccinate (CholHS), a type of cholesteric molecule, into the polymersome bilayers to inhibit the drug release during blood circulation. Actually, unwanted premature drug leakage before arriving at the acidic tumor site has become a serious problem for polymersomes encapsulating water-soluble drugs, especially when the drug loading is at a high level, thus limiting the therapeutic efficacy. In this study, polymersomes displayed high loading capability of doxorubicin hydrochloride as 12.83%. More importantly, CholHS incorporation decreased the membrane permeability of the polymersome and effectively retarded the cargo release under physiological conditions but induced the fast drug-release rate at pH 5.5, demonstrating a more remarkably acid-responsive release behavior when compared to that of the CholHS-free polymersomes. Further in vivo investigations including pharmacokinetic and antitumor activity studies verified the extended circulation time and enhanced antitumor efficacy of the drug-loaded CholHS-incorporated polymersomes.