Self-controlled release of Oxaliplatin prodrug from d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) functionalized mesoporous silica nanoparticles for cancer therapy

Advanced therapeutic strategy: A single-dose injection of a dual-loaded 6-mercaptopurine gelatin-based hydrogel for effective inhibition of tumor growth

The suboptimal aqueous solubility and pronounced systemic toxicity pose significant constraints on the clinical utility of 6-mercaptopurine (6-MP). This study presents an innovative approach using injectable sustained-release hydrogels for localized drug delivery. A gelatin-based anticancer hydrogel (Gel-MP@Gel@6-MP) was developed to deliver 6-MP through both physical encapsulation and chemical coupling via CS bonds, providing a multistage sustained release platform. In vitro experiments demonstrated that physically encapsuled drug achieved rapid release within 4 h, comparable to intravenous administration kinetics. Furthermore, in the presence of glutathione (GSH), nucleophilic attack triggered slow release of S-(6-purinyl) glutathione (PG) and a minor amount of 6-MP, with sustained release observed for up to 96 h. This suggests that, in contrast to conventional delivery methods, the proposed system not only facilitates an initial high-concentration drug release lasting hours, but also enables the sustained release of drug fragments over an extended period of several days, owing to the gradual cleavage of chemical bonds following one single injection. Ultimately, in vivo antitumor studies revealed superior tumor inhibition with Gel-MP@Gel@6-MP compared to free 6-MP. This dual drug loading strategy significantly prolongs drug action duration and obviates the necessity for repeated drug administrations, thereby revealing the diverse modes of drug administration.

Stimuli-Responsive Covalent Organic Frameworks for Cancer Therapy

Chemotherapy as a common anticancer therapeutic modality is often challenged by various obstacles such as poor stability, low solubility, and severe side effects of chemotherapeutic agents as well as multidrug resistance of cancerous cells. Nanoparticles in the role of carriers for chemotherapeutic drugs and platforms for combining different therapeutic approaches have effectively participated in overcoming such drawbacks. In particular, nanoparticles able to induce their therapeutic effect in response to specific stimuli like tumor microenvironment characteristics (e.g., hypoxia, acidic pH, high levels of glutathione, and overexpressed hydrogen peroxide) or extrinsic stimulus of laser light bring about more precise and selective treatments. Among them, nanostructures of covalent organic frameworks (COFs) have drawn great interest in biomedical fields during recent years. Possessing large surface area, high porosity, structural stability, and customizable architecture, these biocompatible porous crystalline polymers properly translate to promising platforms for drug delivery and induction of combination therapies. With the focus on stimuli-responsive characteristics of nanoscale COFs, this study aims to propose an overview of their potentiality in cancer treatment on the basis of chemotherapy alone or in combination with sonodynamic, chemodynamic, photodynamic, and photothermal therapies.

Computational Simulation Study of Potential Inhibition of c-Met Kinase Receptor by Phenoxy pyridine Derivatives: Based on QSAR, Molecular Docking, Molecular Dynamics

The mesenchymal-epithelial transition factor (c-Met) is a tyrosine kinase receptor protein, and excessive cell transformation can lead to cancer. Therefore, there is an urgent need to develop novel receptor tyrosine kinase inhibitors by inhibiting the activity of c-Met protein. In this study, 41 compounds are selected from the reported literature, and the interactions between phenoxy pyridine derivatives and tumor-associated proteins are systematically investigated using a series of computer-assisted drug design (CADD) methods, aiming to predict potential c-Met inhibitors with high activity. The Topomer CoMFA (q2=0.620, R2=0.837) and HQSAR (q2=0.684, R2=0.877) models demonstrate a high level of robustness. Further internal and external validation assessments show high applicability and accuracy. Based on the results of the Topomer CoMFA model, structural fragments with higher contribution values are identified and randomly combined using a fragment splice technique, result in a total of 20 compounds with predicted activities higher than the template molecules. Molecular docking results show that these compounds have good interactions and van der Waals forces with the target proteins. The results of molecular dynamics and ADMET predictions indicate that compounds Y4, Y5, and Y14 have potential as c-Met inhibitors. Among them, compound Y14 exhibits superior stability with a binding free energy of -165.18 KJ/mol. These studies provide a reference for the future design and development of novel compounds with c-Met inhibitory activity.

A review of chitosan in gene therapy: Developments and challenges

Gene therapy, as a revolutionary treatment, has been gaining more and more attention. The key to gene therapy is the selection of suitable vectors for protection of exogenous nucleic acid molecules and enabling their specific release in target cells. While viral vectors have been widely used in researches, non-viral vectors are receiving more attention due to its advantages. Chitosan (CS) has been widely used as non-viral organic gene carrier because of its good biocompatibility and its ability to load large amounts of nucleic acids. This paper summarizes and evaluates the potential of chitosan and its derivatives as gene delivery vector materials, along with factors influencing transfection efficiency, performance evaluation, ways to optimize infectious efficiency, and the current main research development directions. Additionally, it provides an outlook on its future prospects.

Paclitaxel-loaded ROS-responsive nanoparticles for head and neck cancer therapy

High intracellular reactive oxygen species (ROS) level is characteristic of cancer cells and could act as a target for the efficient targeted drug delivery for cancer treatment. Consequently, biomaterials that react to excessive levels of ROS are essential for biomedical applications. In this study, a novel ROS-responsive polymer based on D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) and poly (β-thioester) (TPGS-PBTE) was synthesized for targeted delivery of the first-line antineoplastic drug, paclitaxel (PTX). The resultant TPGS-PBTE NPs showed good ROS-responsive capability in size change and drug release. Compared to PTX, PTX-loaded nanoparticles (PTX@TPGS-PBTE NPs) showed enhanced cytotoxicity and higher level of apoptosis toward squamous cell carcinoma (SCC-7) cells. Tumor-targeted delivery of the NPs was also observed, especially after being modified with a tumor-targeting peptide, cRGD. Enhanced tumor growth inhibition was also observed in head and neck cancer SCC-7 murine models. In summary, PTX@TPGS-PBTE NPs can achieve good therapeutic effects of PTX against head and neck cancer both in vitro and in vivo, especially when modified by cRGD for active targeting, which enriched the application of ROS responsive system utilized in the delivery of anticancer drugs.

Synthesis and characterization of Mg-hydroxyapatite and its cellulose hybridized structure as enhanced bio-carrier of oxaliplatin drug; equilibrium and release kinetics

An advanced form of magnesium-doped hydroxyapatite (Mg HAP) was synthesized and hybridized with cellulose fibers, producing a safe biocomposite (CF/Mg HAP) as an enhanced delivery structure of traditional oxaliplatin (OXPN) chemotherapy drug during the treatment stages of colorectal cancer. The qualifications of CF/Mg HAP as a carrier for OXPN were followed based on loading, release, and cytotoxicity as compared to Mg HAP. The CF/Mg HAP composite exhibits a notably higher OXPN encapsulation capacity (256.2 mg g-1) than the Mg HAP phase (148.9 mg g-1). The OXPN encapsulation process into CF/Mg HAP displays the isotherm behavior of the Langmuir model (R2 = 0.99) and the kinetic assumptions of pseudo-first-order kinetics (R2 > 0.95). The steric studies reflect a strong increment in the quantities of the free sites after the cellulose hybridization steps (Nm = 178.58 mg g-1) as compared to pure Mg HAP (Nm = 69.39 mg g-1). Also, the capacity of each site was enhanced to be loaded by 2 OXPN molecules (n = 1.43) in a vertical orientation. The OXPN encapsulation energy into CF/Mg HAP (<40 kJ mol-1) reflects physical encapsulation reactions involving van der Waals forces and hydrogen bonding. The OXPN release profiles of CF/Mg HAP exhibit slow and controlled properties for about 100 h, either at pH 5.5 or pH 7.4. The release kinetics and diffusion exponent (>0.45) signify non-Fickian transport and a complex erosion/diffusion release mechanism. The free CF/Mg HAP particles display a considerable cytotoxic effect on the HCT-116 cancer cells (21.82% cell viability), and their OXPN-loaded product shows a strong cytotoxic effect (1.85% cell viability).

A computer-aided drug design approach to explore novel type II inhibitors of c-Met receptor tyrosine kinase for cancer therapy: QSAR, molecular docking, ADMET and molecular dynamics simulations

Small molecules such as 4-phenoxypyridine derivatives have remarkable inhibitory activity against c-Met enzymatic activity and proliferation of cancer cell lines. Since there is a relationship between structure and biological activity of these molecules, these little compounds may have great potential for clinical pharmaceutical use against various types of cancer caused by c-Met activity. The purpose of this study was to remodel the structures of 4-phenoxypyridine derivatives to achieve strong inhibitory activity against c-Met and provide favorable pharmacokinetic properties for drug design and discovery. Therefore, this paper describes the structure-activity relationship and the rationalization of appropriate pharmacophore sites to improve the biological activity of the investigated molecules, based on bioinformatics techniques represented by a computer-aided drug design approach. Accordingly, robust and reliable 3D-QSAR models were developed based on CoMFA and CoMSIA techniques. As a result, 46 lead molecules were designed and their biological and pharmacokinetic activities were predicted in silico. Screening filters by 3D-QSAR, Molecular Docking, drug-like and ADME-Tox identified the computer-designed compounds P54 and P55 as the best candidates to achieve high inhibition of c-Met enzymatic activity compared to the synthesized template compound T14. Finally, through molecular dynamics simulations, the structural properties and dynamics of c-Met free and complex (PDB code: 3LQ8) in the presence of 4-phenoxypyridine-derived compounds in an aqueous environment are discussed. Overall, the rectosynthesis of the designed drug inhibitors (P54 and P55) and their in vitro and in vivo bioactivity evaluation may be attractive for design and discovery of novel drug effective to inhibit c-Met enzymatic activity.Communicated by Ramaswamy H. Sarma.

Insight into the Morphological Properties of Nano-Kaolinite (Nanoscrolls and Nanosheets) on Its Qualification as Delivery Structure of Oxaliplatin: Loading, Release, and Kinetic Studies

Natural kaolinite underwent advanced morphological-modification processes that involved exfoliation of its layers into separated single nanosheets (KNs) and scrolled nanoparticles as nanotubes (KNTs). Synthetic nanostructures have been characterized as advanced and effective oxaliplatin-medication (OXAP) delivery systems. The morphological-transformation processes resulted in a remarkable enhancement in the loading capacity to 304.9 mg/g (KNs) and 473 mg/g (KNTs) instead of 29.6 mg/g for raw kaolinite. The loading reactions that occurred by KNs and KNTs displayed classic pseudo-first-order kinetics (R² > 0.90) and conventional Langmuir isotherms (R² = 0.99). KNTs exhibit a higher active site density (80.8 mg/g) in comparison to KNs (66.3 mg/g) and raw kaolinite (6.5 mg/g). Furthermore, compared to KNs and raw kaolinite, each site on the surface of KNTs may hold up to six molecules of OXAP (n = 5.8), in comparison with five molecules for KNs. This was accomplished by multi-molecular processes, including physical mechanisms considering both the Gaussian energy (<8 KJ/mol) and the loading energy (<40 KJ/mol). The release activity of OXAP from KNs and KNTs exhibits continuous and regulated profiles up to 100 h, either by KNs or KNTs, with substantially faster characteristics for KNTs. Based on the release kinetic investigations, the release processes have non-Fickian transport-release features, indicating cooperative-diffusion and erosion-release mechanisms. The synthesized structures have a significant cytotoxicity impact on HCT-116 cancer cell lines (KNs (71.4% cell viability and 143.6 g/mL IC-50); KNTs (11.3% cell viability and 114.3 g/mL IC-50). Additionally, these carriers dramatically increase OXAP's cytotoxicity (2.04% cell viability, 15.4 g/mL IC-50 (OXAP/KNs); 0.6% cell viability, 4.5 g/mL IC-50 (OXAP/KNTs)).

Characterization of cellulose-functionalized phillipsite biocomposite as an enhanced carrier of oxaliplatin drug during the treatment of colorectal cancer: loading, release, and cytotoxicity

Natural phillipsite (N.Ph) was hybridized with cellulose fibers to produce a safe biocomposite (CF/N.Ph) as an enhanced delivery structure of traditional oxaliplatin (OXPN) chemotherapy during the treatment stages of colorectal cancer cells. The requirements of CF/N.Ph as a carrier for OXPN were followed based on the loading, release, and cytotoxicity compared to N.Ph. CF/N.Ph composite exhibits a notably higher OXPN encapsulation capacity (311.03 mg g^-1) than the N.Ph phase (79.6 mg g^-1). The OXPN encapsulation processes into CF/N.Ph display the isotherm behavior of the Freundlich model (R² = 0.99) and the kinetic assumptions of pseudo-first order kinetic (R² > 0.95). The steric studies reflect a strong increment in the quantities of the free sites after the cellulose hybridization steps (Nm = 100.01 mg g^-1) compared to pure N.Ph (Nm = 27.94 mg g^-1). Additionally, the capacity of each site was enhanced to be loaded by 4 OXPN molecules (n = 3.11) compared to 3 by N.Ph (n = 2.85) in a vertical orientation. The OXPN encapsulation energy into CF/N.Ph (<40 kJ mol^-1) reflects physical encapsulation reactions involving electrostatic attraction, van der Waals forces, and hydrogen bonding. The OXPN release profiles of CF/N.Ph exhibit slow and controlled properties for about 150 h either at pH 5.5 or at pH 7.4. The release kinetics and diffusion exponent (>0.45) signify non-Fickian transport and a complex erosion/diffusion release mechanism. The free CF/N.Ph particles display a considerable cytotoxic effect on HCT-116 cancer cells (46.91% cell viability), and its OXPN-loaded product shows a strong cytotoxic effect (3.14% cell viability).

Synthesis and characterization of cellulose functionalized zeolitic diatomite as an enhanced carrier of oxaliplatin drug; loading, release, and cytotoxicity

Natural diatomite frustules (D) were incorporated in zeolitization and cellulose functionalization processes to obtain zeolitized diatomite (ZD) and cellulose fibrous/zeolitized diatomite composite (CF/ZD). The modified products were assessed as potential carriers of oxaliplatin drug (OXPL) with enhanced properties. The prepared ZD (112.5 mg/g) and CF/ZD (268.3 mg/g) structures exhibit significantly enhanced encapsulation capacities as compared to raw diatomite (65.9 mg/g). The occurred encapsulation reactions follow the classic Pseudo-first order kinetic (R² > 0.93) and traditional Langmuir isotherm (R² = 0.99). The estimated effective encapsulation site density of CF/ZD is 104.8 mg/g which is a notably higher value than ZD (44.6 mg/g) and D (28.4 mg/g). Moreover, each effective site can be occupied with up to 3 molecules of OXPL molecules in vertical forms involving multi-molecular mechanisms. The encapsulation energy (<40 KJ/mol) suggested the predominant effects of the physical mechanisms during the encapsulation reactions. The release profiles of ZD as well as CF/ZD exhibit slow and controlled properties for about 100 h either at pH 5.5 or at pH 7.4. The release kinetic studies involving the obtained diffusion exponent values (>0.45) suggested non-Fickian transport and complex erosion/diffusion release mechanism. These structures exhibit enhanced cytotoxic effects on the HCT-116 cancer cell lines (D (18.78 % cell viability), ZD (9.76 % cell viability), and CF/ZD (3.16 % cell viability).

Application of Mesoporous Silica Nanoparticles in Cancer Therapy and Delivery of Repurposed Anthelmintics for Cancer Therapy

This review focuses on the biomedical application of mesoporous silica nanoparticles (MSNs), mainly focusing on the therapeutic application of MSNs for cancer treatment and specifically on overcoming the challenges of currently available anthelmintics (e.g., low water solubility) as repurposed drugs for cancer treatment. MSNs, due to their promising features, such as tunable pore size and volume, ability to control the drug release, and ability to convert the crystalline state of drugs to an amorphous state, are appropriate carriers for drug delivery with the improved solubility of hydrophobic drugs. The biomedical applications of MSNs can be further improved by the development of MSN-based multimodal anticancer therapeutics (e.g., photosensitizer-, photothermal-, and chemotherapeutics-modified MSNs) and chemical modifications, such as poly ethyleneglycol (PEG)ylation. In this review, various applications of MSNs (photodynamic and sonodynamic therapies, chemotherapy, radiation therapy, gene therapy, immunotherapy) and, in particular, as the carrier of anthelmintics for cancer therapy have been discussed. Additionally, the issues related to the safety of these nanoparticles have been deeply discussed. According to the findings of this literature review, the applications of MSN nanosystems for cancer therapy are a promising approach to improving the efficacy of the diagnostic and chemotherapeutic agents. Moreover, the MSN systems seem to be an efficient strategy to further help to decrease treatment costs by reducing the drug dose.

Enhancement of anti-neoplastic effects of cuminaldehyde against breast cancer via mesoporous silica nanoparticle based targeted drug delivery system

AIMS

Synthesis of novel drug delivery system for targeted delivery of cuminaldehyde to breast cancer cells and the subsequent analyses of anti-neoplastic potential of the drug.

MAIN METHODS

3-carboxy-phenyl boronic acid (PBA) conjugated and polyacrylic acid (PAA) gated mesoporous silica nanoparticles (MSNs) were synthesized for the targeted delivery of cuminaldehyde (CUM) to breast cancer cells. Enhancement of anti-neoplastic effects of cuminaldehyde (4-isopropylbenzaldehyde) by the nanoconjugates was assessed.

KEY FINDINGS

The anti-cancer effects of non-targeted and targeted drug-nanoconjugates were examined in vitro and in vivo. The targeted drug-nanoconjugates caused cell cycle arrest and induced the intrinsic pathway of apoptosis in MCF-7 cells through mitochondrial damage. In vivo intravenous injection of the targeted drug-nanoconjugates led to effective reduction in growth of 4 T1 induced mammary pad tumor in female BALB/c mice via augmented accumulation of cuminaldehyde. The drug-nanoconjugates did not exhibit any systemic toxicity.

SIGNIFICANCE

Therefore, MSN-PBA-CUM-PAA represents a potent therapeutic model for breast cancer treatment.

Nanotherapeutics approaches to overcome P-glycoprotein-mediated multi-drug resistance in cancer

Multidrug resistance (MDR) in cancer chemotherapy is a growing concern for medical practitioners. P-glycoprotein (P-gp) overexpression is one of the major reasons for multidrug resistance in cancer chemotherapy. The P-gp overexpression in cancer cells depends on several factors like adenosine triphosphate (ATP) hydrolysis, hypoxia-inducible factor 1 alpha (HIF-1α), and drug physicochemical properties such as lipophilicity, molecular weight, and molecular size. Further multiple exposures of anticancer drugs to the P-gp efflux protein cause acquired P-gp overexpression. Unique structural and functional characteristics of nanotechnology-based drug delivery systems provide opportunities to circumvent P-gp mediated MDR. The primary mechanism behind the nanocarrier systems in P-gp inhibition includes: bypassing or inhibiting the P-gp efflux pump to combat MDR. In this review, we discuss the role of P-gp in MDR and highlight the recent progress in different nanocarriers to overcome P-gp mediated MDR in terms of their limitations and potentials.

Mesoporous silica nanoparticles for pulmonary drug delivery

Over the last years, respiratory diseases represent a clinical concern, being included among the leading causes of death in the world due to the lack of effective lung therapies, mainly ascribed to the pulmonary barriers affecting the delivery of drugs to the lungs. In this way, nanomedicine has arisen as a promising approach to overcome the limitations of current therapies for pulmonary diseases. The use of nanoparticles allows enhancing drug bioavailability at the target site while minimizing undesired side effects. Despite different approaches have been developed for pulmonary delivery of drugs, including the use of polymers, lipid-based nanoparticles, and inorganic nanoparticles, more efforts are required to achieve effective pulmonary drug delivery. This review provides an overview of the clinical challenges in main lung diseases, as well as highlighted the role of nanomedicine in achieving efficient pulmonary drug delivery. Drug delivery into the lungs is a complex process limited by the anatomical, physiological and immunological barriers of the respiratory system. We discuss how nanomedicine can be useful to overcome these pulmonary barriers and give insights for the rational design of future nanoparticles for enhancing lung treatments. We also attempt herein to display more in detail the potential of mesoporous silica nanoparticles (MSNs) as promising nanocarrier for pulmonary drug delivery by providing a comprehensive overview of their application in lung delivery to date while discussing the use of these particles for the treatment of respiratory diseases.

In-vitro evaluation of dendrimeric formulation of oxaliplatin

The aim of this study is, preparing various dendrimeric formulations of oxaliplatin and investigating their properties. First of all, the solubility enhancement capabilities of polyamidoamine (PAMAM) G3.5 and PAMAM G4.5 dendrimers were investigated. The results showed that oxaliplatin solubility mostly increasing linearly with dendrimer concentration. Additionally, the increase was more notable in PAMAM G4.5 dendrimers. Then, drug-dendrimer complexes were prepared in different mediums, since the medium used can affect the amount of drug-loaded to dendrimers. Prepared complexes were examined for loading capacity and loading efficiency. It was found that PAMAM G4.5 dendrimers can complex with 2- to 5-fold more oxaliplatin than PAMAM G3.5. Finally, oxaliplatin was modified to a platinum (IV) compound to prepare chemical drug-dendrimer conjugates. Ester bonds were established by Steglich esterification through the hydroxyl group of modified oxaliplatin and the carboxyl groups of the dendrimers. The formulations were characterized by UV, IR, NMR spectroscopy, and dynamic light scattering techniques. PAMAM G3.5 conjugate was further evaluated for the cytotoxicity test. The IC₅₀ value of PAMAM G3.5 conjugate was found as 0.72 µM. For unmodified oxaliplatin, this value was 14.03 µM. As a result, a dendrimer-based drug delivery system that has been found promising for further improvement has been developed successfully.

Progress in the study of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) reversing multidrug resistance

Currently, multidrug resistance (MDR) is one of the major reasons for failure in clinical cancer chemotherapy. Overexpression of the ATP binding cassette (ABC) transporter P-glycoprotein (P-gp), which significantly increases the efflux of anticancer drugs from tumor cells, enhances MDR. In the past few decades, four generations of P-gp inhibitors have appeared. However, they are limited in clinical application due to their severe toxic side effects. As a P-gp inhibitor and carrier for loading chemotherapy agents, TPGS has received increasing attention due to its advantages and unique properties of reversing MDR. TPGS is an amphipathic agent that increases the solubility of most chemotherapy drugs and decreases severe side effects. In addition, TPGS is an excellent carrier with P-gp-inhibiting ability. In this review, we summarize the latest articles on TPGS-based nanodelivery systems to prevent MDR.

Synthesis and evaluation of new compounds bearing 3-(4-aminopiperidin-1-yl)methyl magnolol scaffold as anticancer agents for the treatment of non-small cell lung cancer via targeting autophagy

Magnolol and honokiol are the two major active ingredients with similar structure and anticancer activity from traditional Chinese medicine Magnolia officinalis, and honokiol is now in a phase I clinical trial (CTR20170822) for advanced non-small cell lung cancer (NSCLC). In search of potent lead compounds with better activity, our previous study has demonstrated that magnolol derivative C2, 3-(4-aminopiperidin-1-yl)methyl magnolol, has better activity than honokiol. Here, based on the core of 3-(4-aminopiperidin-1-yl)methyl magnolol, we synthesized fifty-one magnolol derivatives. Among them, compound 30 exhibited the most potent antiproliferative activities on H460, HCC827, H1975 cell lines with the IC50 values of 0.63-0.93 μM, which were approximately 10- and 100-fold more potent than those of C2 and magnolol, respectively. Besides, oral administration of 30 and C2 on an H460 xenograft model also demonstrated that 30 has better activity than C2. Mechanism study revealed that 30 induced G0/G1 phase cell cycle arrest, apoptosis and autophagy in cancer cells. Moreover, blocking autophagy by the autophagic inhibitor enhanced the anticancer activity of 30in vitro and in vivo, suggesting autophagy played a cytoprotective role on 30-induced cancer cell death. Taken together, our study implied that compound 30 combined with autophagic inhibitor could be another choice for NSCLC treatment in further investigation.

Maximizing the potency of oxaliplatin coated nanoparticles with folic acid for modulating tumor progression in colorectal cancer

One of the challenges of nanotechnology is to improve the efficacy of treatments for diseases, in order to reduce morbidity and mortality rates. Following this line of study, we made a nanoparticle formulation with a small size, uniform surfaces, and a satisfactory encapsulation coefficient as a target for colorectal cancer cells. The results of binding and uptake prove that using the target system with folic acid works: Using this system, cytotoxicity and cell death are increased when compared to using free oxaliplatin. The data show that the system maximized the efficiency of oxaliplatin in modulating tumor progression, increasing apoptosis and decreasing resistance to the drug. Thus, for the first time, our findings suggest that PLGA-PEG-FA increases the antitumor effectiveness of oxaliplatin by functioning as a facilitator of drug delivery in colorectal cancer.

Synthesis of mesoporous silicate molecular sieves by the aerosol-assisted method for loading and release of drug

The mesoporous silicate molecular sieves were synthesized with polyether F127 as the template by the aerosol-assisted method for loading and release of ibuprofen (IBU). The synthesized samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and N2 adsorption-desorption isotherms. The drug IBU was applied as a model drug to investigate the drug release behaviour by ultraviolet spectrophotometry measurements. The investigation results demonstrate that mesoporous silicate molecular sieves by the aerosol-assisted method are spherical with a core-shell structure. As the drug carrier, it has good structural stability and can achieve drug controlled release which is expected. It exhibits safety to a certain degree. Therefore, the aerosol-assisted synthesis method provides a new idea for the synthesis of sustained-release drug carriers.

Long-Circulating Thermosensitive Liposomes for the Targeted Drug Delivery of Oxaliplatin

Introduction

Oxaliplatin (L-OHP) is a well-known third-generation platinum anticancer drug with severe systemic- and neuro-toxicity. The main objective of the current research was to develop a targeted long-circulating thermosensitive smart-release liposome (LCTL) system for better therapeutic efficacy and less toxicity.

Methods

The reverse-phase evaporation method (REV) was used to prepare L-OHP loaded LCTL (L-OHP/LCTL). The physical characteristics were evaluated including encapsulation efficiency (EE), size, zeta potential and stability. The release behavior, cytotoxicity and in vivo evaluation were also carried out.

Results

EE of LCTL was around 25% with a uniform size distribution, and LCTL achieved almost complete release at 42°C while it was only 10% at 37°C. Moreover, the LCTL showed significantly higher cytotoxicity at 42°C than that at 37°C. The in vivo results indicated LCTL could target tumors and enhance retention for more than 24 h, thereby enhancing anti-tumor efficacy on 4T1-bearing mice.

Discussion

These results indicated that LCTL not only possessed a prolonged circulation time but it also enhanced accumulation and achieved selective release at the tumor sites. Conclusively, LCTL could serve as a promising carrier for oxaliplatin delivery to treat solid tumors.

Biodegradable nanocarriers based on chitosan-modified mesoporous silica nanoparticles for delivery of methotrexate for application in breast cancer treatment

Nanocarriers have demonstrated great promise in the delivery of hydrophobic drugs particularly to tumor spaces by enhanced permeability and retention (EPR) effects. Mesoporous silica nanoparticles (MSNs) are the attractive nanocarrier system to reduce the drug's toxic side effects, enable controlled drug release, prevent drug degradation and provide a biocompatible and biodegradable high surface area carrier. Surface-modified MSNs have been applied to increase drug loading and efficiency. In this study, functionalized MSNs loaded with methotrexate (MTX) were designed for use as a cytotoxic agent. The MSNs were first modified with 3-triethoxysilylpropylamine (APTES) and then with chitosan through covalent coupling mediated by glutaraldehyde. The physicochemical properties of the nanoparticles were optimized for each step. The loading percentage (12.2%) and release profile of MTX as an anti-breast cancer drug, loaded at amine-modified MSNs, were measured via high performance liquid chromatography (HPLC). Moreover, the uptake profiles of fluorescein isothiocyanate (FITC)-labeled MSN-APTES-chitosan with or without MTX were monitored on MCF7 cancer cells via confocal microscopy. Following exposure of nanoparticles to body fluids, they were surrounded by specific proteins that may affect their cellular uptake. Hence, the adsorption profiles of protein corona on the surface of MSN, amine-modified MSN and MTX-loaded MSN-APTES-chitosan were analyzed. The cytotoxic potential for killing breast cancer cells was also studied. The MTX loaded MSN-APTES-chitosan showed a positive effect at a low dose (0.5 μM MTX). In this study, we introduce a new method to synthesize biodegradable MSNs with small and uniform particle size, achieve high MTX loading via covalent amine and chitosan-functionalization, monitor the cellular uptake and demonstrate the potential to decrease the viability of breast cancer cells at low dose.

Insight into the Loading and Release Properties of an Exfoliated Kaolinite/Cellulose Fiber (EXK/CF) Composite as a Carrier for Oxaliplatin Drug: Cytotoxicity and Release Kinetics

Kaolinite layers were exfoliated as single sheets and admixed with cellulose fibers, forming an advanced exfoliated kaolinite/cellulose fiber (EXK/CF) composite, which was characterized as a promising carrier for the oxaliplatin (OL) drug to induce safety as well as the therapeutic effect. The EXK/CF composite exhibited promising loading capacity and achieved an experimental value of 670 mg/g and an expected theoretical value of 704.4 mg/g. The loading behavior of OL using the EXK/CF composite followed the pseudo-first-order kinetic model and the Langmuir equilibrium model, achieving an adsorption energy of 7.7 kJ/mol. This suggested physisorption and homogeneous loading behavior of the OL molecules in a monolayer form. The release profile of OL from EXK/CF continued for about 100 h with maximum release percentages of 86.4 and 95.2% in the phosphate and acetate buffers, respectively. The determined diffusion exponent from the Korsmeyer-Peppas kinetic model suggested non-Fickian transport behavior of the OL molecules and releasing behavior controlled by erosion as well as diffusion mechanisms. Regarding the cytotoxic effect, the EXK/CF composite has a high safety impact on the normal colorectal cells (CCD-18Co) and higher toxic impacts on the colorectal cancer cell (HCT116) than the free oxaliplatin drug.

Modification of Mesoporous Silica Surface by Immobilization of Functional Groups for Controlled Drug Release

This paper introduces the synthesis of mesoporous silica nanoparticles (MSNs) with three different groups such as amine, thiol, and sulfonic acid, along the internal surface. Trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride was used to modify the external surface of the nanomaterials. Such materials allow control of the drug release from MSN pores. Multifunctional MSNs were loaded with doxycycline (Doxy) to study their capacities and uploading time. The loading profile indicates that sulfonic groups in the internal surface were the most efficient surfaces with a loading capacity of ca. 35% in 90 min in acidic media.

Effect of mesoporous silica nanoparticles co‑loading with 17‑AAG and Torin2 on anaplastic thyroid carcinoma by targeting VEGFR2

Anaplastic thyroid carcinoma (ATC) is a highly aggressive tumor with a poor prognosis and a low median survival rate because of insufficient effective therapeutic modalities. Recently, mesoporous silica nanoparticles (MSNs) as a green non-toxic and safe nanomaterial have shown advantages to be a drug carrier and to modify the targeting group to the targeted therapy. To aim of the study was to explore the effects of MSNs co-loading with 17-allylamino-17-demethoxy-geldanamycin (17-AAG; HSP90 inhibitor) and 9-(6-aminopyridin-3-yl)-1-(3-(trifluoromethyl)phenyl)benzo[h][1,6]naphthyridin-2(1H)-one (Torin2; mTOR inhibitor) by targeting vascular endothelial growth factor receptor 2 (VEGFR2) on the viability of human anaplastic thyroid carcinoma FRO cells. The cytotoxicity of 17-AAG and Torin2 were analyzed by MTT assay. The possible synergistic antitumor effects between 17-AAG and Torin2 were evaluated by CompuSyn software. Flow cytometry was performed to assess the VEGFR2 targeting of (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab and uptake by FRO cells. An ATC xenograft mouse model was established to assess the antitumor effect of (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab in vivo. The results revealed that the combination of 17-AAG and Torin2 inhibited the growth of FRO cells more effectively compared with single use of these agents. Additionally, the synergistic antitumor effect appeared when concentration ratio of the two drugs was 1:1 along with total drug concentration greater than 0.52 µM. Furthermore, in an ATC animal model, it was revealed that the (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab therapy modality could most effectively prolong the median survival time [39.5 days vs. 33.0 days (non-targeted) or 27.5 days (control)]. Compared to (17-AAG+Torin2)@MSNs, the (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab could not only inhibit ATC cell growth but also prolong the median survival time of tumor-bearing mice in vivo and vitro more effectively, which may provide a new promising therapy for ATC.

pH and Redox Dual-Responsive MSN-S-S-CS as a Drug Delivery System in Cancer Therapy

In order to achieve a controlled release drug delivery system (DDS) for cancer therapy, a pH and redox dual-responsive mesoporous silica nanoparticles (MSN)-sulfur (S)-S- chitosan (CS) DDS was prepared via an amide reaction of dithiodipropionic acid with amino groups on the surface of MSN and amino groups on the surface of CS. Using salicylic acid (SA) as a model drug, SA@MSN-S-S-CS was prepared by an impregnation method. Subsequently, the stability, swelling properties and drug release properties of the DDS were studied by x-ray diffraction, scanning electron microscopy, Fourier transform infrared microspectroscopy, size and zeta potential as well as Brunauer-Emmett-Teller surface area. Pore size and volume of the composites decreased after drug loading but maintained a stable structure. The calculated drug loading rate and encapsulation efficiency were 8.17% and 55.64%, respectively. The in vitro drug release rate was 21.54% in response to glutathione, and the release rate showed a marked increase as the pH decreased. Overall, double response functions of MSN-S-S-CS had unique advantages in controlled drug delivery, and may be a new clinical application of DDS in cancer therapy.

Self-assembled multifunctional nanotheranostics loading GEM for targeted lung cancer therapy

The aim of this study was to prepare a promising drug carrier for treatment of lung cancer. The self-assembly nanoparticles of SDP-GEM/PEI-PEG-anti-EGFR with chemotherapeutic drug of gemcitabine (GEM), Magnetic resonance imaging (MRI) guided- imaging and targeting of anti- Epidermal Growth Factor Receptor (anti-EGFR) were designed. The imaging capacity, targeting feasibility and anti-tumor function were evaluated respectively. SDP-GEM/PEI-PEG-anti-EGFR exhibited contrast enhancement under T2 Weight Image (T2WI) and a liner relationship was found between the concentration and relaxation rate of R2 and R2* in vitro. With the targeting of anti-EGFR, the endocytosis of nanoparticles increased significantly, which effectively killed lung cancer cells in vitro, and importantly it can be accurately delivered to tumor site within 3 h in vivo. Prolonged lifetime and smaller tumor volume demonstrated that SDP-GEM/PEI-PEG-anti-EGFR efficiently inhibited tumor growth in vivo. Therefore, SDP-GEM/PEI-PEG-anti-EGFR was an effective and safe drug carrier, which had a great potential application in MRI-guided lung cancer therapy.

Enteric pH responsive cargo release from PDA and PEG coated mesoporous silica nanoparticles: a comparative study in Drosophila melanogaster

Physiological stimulus-specific cargo release from nanoparticle carriers is a holy grail of drug delivery research. While the majority of such work is carried out in vitro with cell lines, widespread use of common mammalian model systems – mice and rats – is difficult due to the associated cost and regulatory restrictions. Here we use the inexpensive, easily reared, excellent genetic model system Drosophila melanogaster to test pH responsive cargo release from widely used mesoporous silica nanoparticles (MSNs) coated with pH sensitive polydopamine (PDA) and polyethylene glycol (PEG) polymers. We synthesized 650 ± 75 nm diameter PDA or PEG coated mesoporous silica nanoparticles loaded with a fluorescent dye and fed to individual adult flies. Subsequently, the passage of the particles were monitored through the fly gut. As in mammals, the fly intestine has multiple pH specific zones that are easily accessible for imaging and also genetic, biochemical or physiological manipulations. We observed that both the species of MSNs ruptured around the acidic (pH < 4.0) middle midgut of the flies. PEG coated particles showed sharper specificity of release in the acidic middle midgut of flies than the PDA coated ones and had less tendency to clump together. Our results clearly show that the Drosophila gut can be used as a model to test pH responsive biocompatible materials in vivo. Our work paves the way for greater use of Drosophila as an in vivo complete systemic model in drug delivery and smart materials research. It also suggests that such specific delivery of chemical/biological cargo can be exploited to study basic biology of the gut cells and their communication with other organs.

Targeted delivery in Drosophila middle mid-gut at pH < 4.0.

Zinc oxide end-capped Fe3O4@mSiO2 core-shell nanocarriers as targeted and responsive drug delivery system for chemo-/ions synergistic therapeutics

Multifunctional core-shell nanocarriers based on zinc oxide (ZnO)-gated magnetic mesoporous silica nanoparticles (MMSN) were prepared for cancer treatment through magnetic targeting and pH-triggered controlled drug release. Under an external magnetic field, the MMSN could actively deliver chemotherapeutic agent, daunomycin (DNM), to the targeted sites. At neutral aqueous, the functionalized MMSN could stably accommodate the DNM molecules since the mesopores were capped by the ZnO gatekeepers. In contrast, at the acid intercellular environment, the gatekeepers would be removed to control the release of drugs due to the dissolution of ZnO. Meanwhile, ZnO quantum dots not only rapidly dissolve in an acidic condition of cancer cells but also enhance the anti-cancer effect of Zn2+. An in vitro controlled release proliferation indicated that the acid sensitive ZnO gatekeepers showed well response by the 'on-off' switch of the pores. Cellular experiments against cervical cancer cell (HeLa cells) further showed that functionalized MMSN significantly suppressed cancer cells growth through synergistic effects between the chemotherapy and Zn2+ ions with monitoring the treatment process. These results suggested that the ZnO-gated MMSN platform is a promising approach to serve as a pH-sensitive system for chemotherapies delivery and Zn2+ controlled release for further application in the treatment of various cancers by synergistic effects.

Comparison of the effect of rhodium citrate-associated iron oxide nanoparticles on metastatic and non-metastatic breast cancer cells

Background

Nanocarriers have the potential to improve the therapeutic index of currently available drugs by increasing drug efficacy, lowering drug toxicity and achieving steady-state therapeutic levels of drugs over an extended period. The association of maghemite nanoparticles (NPs) with rhodium citrate (forming the complex hereafter referred to as MRC) has the potential to increase the specificity of the cytotoxic action of the latter compound, since this nanocomposite can be guided or transported to a target by the use of an external magnetic field. However, the behavior of these nanoparticles for an extended time of exposure to breast cancer cells has not yet been explored, and nor has MRC cytotoxicity comparison in different cell lines been performed until now. In this work, the effects of MRC NPs on these cells were analyzed for up to 72 h of exposure, and we focused on comparing NPs’ therapeutic effectiveness in different cell lines to elect the most responsive model, while elucidating the underlying action mechanism.

Results

MRC complexes exhibited broad cytotoxicity on human tumor cells, mainly in the first 24 h. However, while MRC induced cytotoxicity in MDA-MB-231 in a time-dependent manner, progressively decreasing the required dose for significant reduction in cell viability at 48 and 72 h, MCF-7 appears to recover its viability after 48 h of exposure. The recovery of MCF-7 is possibly explained by a resistance mechanism mediated by PGP (P-glycoprotein) proteins, which increase in these cells after MRC treatment. Remaining viable tumor metastatic cells had the migration capacity reduced after treatment with MRC (24 h). Moreover, MRC treatment induced S phase arrest of the cell cycle.

Conclusion

MRC act at the nucleus, inhibiting DNA synthesis and proliferation and inducing cell death. These effects were verified in both tumor lines, but MDA-MB-231 cells seem to be more responsive to the effects of NPs. In addition, NPs may also disrupt the metastatic activity of remaining cells, by reducing their migratory capacity. Our results suggest that MRC nanoparticles are a promising nanomaterial that can provide a convenient route for tumor targeting and treatment, mainly in metastatic cells.