Preparation, Characterization and Evaluation of α-Tocopherol Succinate-Modified Dextran Micelles as Potential Drug Carriers

Improved Cytotoxicity and Induced Apoptosis in HeLa Cells by Co-loading Vitamin E Succinate and Curcumin in Nano-MIL-88B-NH2

One of the strategies for improved therapeutic effects in cancer therapy is combination chemotherapy. In this study, a flexible nano-MOF (Fe-MIL-88B-NH2 ) was synthesized in a sonochemical process, then co-loaded with α-tocopheryl succinate (TOS) and curcumin (CCM). The anticancer activity of co-loaded Fe-MIL-88B-NH2 (Fe-MIL-88B-NH2 /TOS@CCM) against the HeLa cells was compared with that of the single-loaded counterpart (Fe-MIL-88B-NH2 @CCM). MTT analysis indicates improved cytotoxicity of Fe-MIL-88B-NH2 /TOS@CCM. The data from the cell apoptosis assay indicated more apoptosis in the case of the co-loaded nano-MOF. This study indicates the positive effect of the presence of TOS on enhancing the anticancer effect of Fe-MIL-88B-NH2 @CCM to prepare a more efficient drug delivery nanosystem.

Modification of Poly(Glycerol Adipate) with Tocopherol and Cholesterol Modulating Nanoparticle Self-Assemblies and Cellular Responses of Triple-Negative Breast Cancer Cells to SN-38 Delivery

This study aimed to fabricate new variations of glycerol-based polyesters by grafting poly(glycerol adipate) (PGA) with hydrophobic bioactive moieties, tocopherol (TOC), and cholesterol (CHO). Their effects on nanoparticle (NP) formation, drug release, and cellular responses in cancer and normal cells were evaluated. CHO and TOC were successfully grafted onto PGA backbones with 30% and 50% mole grafting. Increasing the percentage of mole grafting in both molecules increased the glass transition temperature and water contact angle of the final polymers but decreased the critical micelle concentration of the formulated particles. PGA-TOC NPs reduced the proliferation of MDA-MB-231 cancer cells. However, they enhanced the proliferation of primary dermal fibroblasts within a specific concentration range. PGA-CHO NPs minimally affected the growth of cancer and normal cells. Both types of NPs did not affect apoptosis or the cell cycle of cancer cells. PGA-CHO and PGA-TOC NPs were able to entrap SN-38, a hydrophobic anticancer drug, with a particle size <200 nm. PGA-CHO NPs had a higher drug loading capacity and a greater drug release than PGA-TOC NPs. However, SN-38-loaded PGA-TOC NPs showed higher toxicity than SN-38 and SN-38-loaded PGA-CHO NPs due to the combined effects of antiproliferation and higher cellular uptake. Compared with SN-38, the drug-loaded NPs more profoundly induced sub-G1 in the cell cycle analysis and apoptosis of cancer cells in a similar pattern. Therefore, PGA-CHO and PGA-TOC polymers have potential applications as delivery systems for anticancer drugs.

Musca domestica (Diptera: Muscidae) as a biological model for the assessment of magnetite nanoparticles toxicity

The use of nanoparticles (NPs) is rapidly expanding; there is a critical need for efficient assays to first determine the potential toxicity of NPs before their use in human applications. Magnetite nanoparticles (Fe₃O₄ NPs) have tremendous applications which include cell separation, arsenic removal from water and DNA separation. Spherically shaped Fe₃O₄ NPs with sizes ranging from 23 to 30 nm were used in this study. The housefly, Musca domestica is the most common fly species. It is present worldwide and considered to be an important medical insect which can carry and transmit over 100 human pathogens and zoonotic agents. It has been used in this study to assess Fe₃O₄NPs toxicity and give us an overview of their impact. The larvicidal activity of Fe₃O₄NPs was tested against the third instar larvae of M. domestica. We investigated the effects of six varying concentrations (15, 30, 45, 60, 75 and 90 μg/mL) used under laboratory conditions in two differential application assays: contact and feeding. The LC₅₀ value for Fe₃O₄ NPs was 60 and 75 μg/mL by feeding and contact, respectively. To investigate the toxicity effects of Fe₃O₄ NPs on houseflies, morphological and histoarchitectural changes in larvae, pupae and adult flies were analyzed. NP exposure caused morphological abnormalities of larvae and pupae as well as larval pupal intermediates, and deformed adult with crumpled wings. Also, some adults couldn't emerge and remained in their puparia. The histological examinations showed that Fe₃O₄ NPs caused severe tissue damage especially in the cuticle and the digestive system. Thus, besides affecting the organ of first contact (digestive system), remote organs such as the integument are also targeted by Fe₃O₄ NPs suggesting a systemic impact on fly development and physiology.

Smartphone enabled miniaturized temperature controller platform to synthesize nio/cuo nanoparticles for electrochemical sensing and nanomicelles for ocular drug delivery applications

Undoubtedly, various kinds of nanomaterials are of great significance due to their enormous applications in diverse areas. The structure and productivity of nanomaterials are heavily dependent on the process used for their synthesis. The synthesizing process plays a vital role in shaping nanomaterials effectively for better productivity. The conventional method requires expensive and massive thermal instruments, a huge volume of reagents. This paper aims to develop an Automatic Miniaturized Temperature Controller (AMTC) device for the synthesis of nickel oxide (NiO), copper oxide (CuO) nanoparticles, and nanomicelles. The device features a low-cost, miniaturized, easy-to-operate with plug-and-play power source, precise temperature control, and geotagged real-time data logging facility for the producing nanoparticles. With a temperature accuracy of ± 2 °C, NiO and CuO nanoparticles, and nanomicelles are synthesized on AMTC device, and are subjected to different characterizations to analyze their morphological structure. The obtained mean size of NiO and CuO is 27.14 nm and 85.13 nm respectively. As a proof-of-principle, the synthesized NiO and CuO nanomaterials are validated for electrochemical sensing of dopamine, hydrazine, and uric acid. Furthermore, the study is conducted, wherein, Dexamethasone (Dex) loaded nanomicelles are developed using AMTC device and compared to the conventional thin-film hydration method. Subsequently, as a proof-of-application, the developed nanomicelles are evaluated for transcorneal penetration using exvivo goat cornea model. Ultimately, the proposed device can be utilized for performing a variety of controlled thermal reactions on a minuscule platform with an integrated and miniaturized approach for various applications.

Micellar Drug Delivery Systems Based on Natural Biopolymers

The broad diversity of structures and the presence of numerous functional groups available for chemical modifications represent an enormous advantage for the development of safe, non-toxic, and cost-effective micellar drug delivery systems (DDS) based on natural biopolymers, such as polysaccharides, proteins, and peptides. Different drug-loading methods are used for the preparation of these micellar systems, but it appeared that dialysis is generally recommended, as it avoids the formation of large micellar aggregates. Moreover, the preparation method has an important influence on micellar size, morphology, and drug loading efficiency. The small size allows the passive accumulation of these micellar systems via the permeability and retention effect. Natural biopolymer-based micellar DDS are high-value biomaterials characterized by good compatibility, biodegradability, long blood circulation time, non-toxicity, non-immunogenicity, and high drug loading, and they are biodegraded to non-toxic products that are easily assimilated by the human body. Even if some recent studies reported better antitumoral effects for the micellar DDS based on polysaccharides than for commercial formulations, their clinical use is not yet generalized. This review is focused on the studies from the last decade concerning the preparation as well as the colloidal and biological characterization of micellar DDS based on natural biopolymers.

Nucleic Acid Delivery with α-Tocopherol-Polyethyleneimine-Polyethylene Glycol Nanocarrier System

Purpose

Nucleic acid-based therapies are a promising therapeutic tool. The major obstacle in their clinical translation is their efficient delivery to the desired tissue. We developed a novel nanosized delivery system composed of conjugates of α-tocopherol, polyethyleneimine, and polyethylene glycol (TPP) to deliver nucleic acids.

Methods

We synthesized a panel of TPP molecules using different molecular weights of PEG and PEI and analyzed with various analytical approaches. The optimized version of TPP (TPP₁₁₁ - the 1:1:1 molecular ratio) was self-assembled in water to produce nanostructures and then evaluated in diversified in vitro and in vivo studies.

Results

Through a panel of synthesized molecules, TPP₁₁₁ conjugate components self-assembled in water, forming globular shaped nanostructures of ~90 nm, with high nucleic acid entrapment efficiency. The polymer had low cytotoxicity in vitro and protected nucleic acids from nucleases. Using a luciferase-expressing plasmid, TPP₁₁₁-plasmid nano-complexes were rapidly up-taken by cancer cells in vitro and induced strong transfection, comparable to PEI. Colocalization of the nano-complexes and endosomes/lysosomes suggested an endosome-mediated uptake. Using a subcutaneous tumor model, intravenously injected nano-complexes preferentially accumulated to the tumor area over 24 h.

Conclusion

These results indicate that we successfully synthesized the TPP₁₁₁ nanocarrier system, which can deliver nucleic acids in vitro and in vivo and merits further evaluation.

Development of stimuli-responsive intelligent polymer micelles for the delivery of doxorubicin

Doxorubicin is still used as a first-line drug in current therapeutics for numerous types of malignant tumours (including lymphoma, transplantable leukaemia and solid tumour). Nevertheless, to overcome the serious side effects like cardiotoxicity and myelosuppression caused by effective doses of doxorubicin remains as a world-class puzzle. In recent years, the usage of biocompatible polymeric nanomaterials to form an intelligently sensitive carrier for the targeted release in tumour microenvironment has attracted wide attention. These different intelligent polymeric micelles (PMs) could change the pharmacokinetics process of drugs or respond in the special microenvironment of tumour site to maximise the efficacy and reduce the toxicity of doxorubicin in other tissues and organs. Several intelligent PMs have already been in the clinical research stage and planned for market. Therefore, related research remains active, and the latest nanotechnology approaches for doxorubicin delivery are always in the spotlight. Centring on the model drugs doxorubicin, this review summarised the mechanisms of PMs, classified the polymers used in the application of doxorubicin delivery and discussed some interesting and imaginative smart PMs in recent years.

Self-assembled nanoparticles of reduction-sensitive poly (lactic-co-glycolic acid)-conjugated chondroitin sulfate A for doxorubicin delivery: preparation, characterization and evaluation

In this study, reduction-sensitive self-assembled polymer nanoparticles based on poly (lactic-co-glycolic acid) (PLGA) and chondroitin sulfate A (CSA) were developed and characterized. PLGA was conjugated with CSA via a disulfide linkage (PLGA-ss-CSA). The critical micelle concentration (CMC) of PLGA-ss-CSA conjugate is 3.5 µg/mL. The anticancer drug doxorubicin (DOX) was chosen as a model drug, and was effectively encapsulated into the nanoparticles (PLGA-ss-CSA/DOX) with high loading efficiency of 15.1%. The cumulative release of DOX from reduction-sensitive nanoparticles was only 34.8% over 96 h in phosphate buffered saline (PBS, pH 7.4). However, in the presence of 20 mM glutathione-containing PBS environment, DOX release was notably accelerated and almost complete from the reduction-sensitive nanoparticles up to 96 h. Moreover, efficient intracellular DOX release of PLGA-ss-CSA/DOX nanoparticles was confirmed by CLSM assay in A549 cells. In vitro cytotoxicity study showed that the half inhibitory concentrations of PLGA-ss-CSA/DOX nanoparticles and free DOX against A549 cells were 1.141 and 1.825 µg/mL, respectively. Therefore, PLGA-ss-CSA/DOX nanoparticles enhanced the cytotoxicity of DOX in vitro. These results suggested that PLGA-ss-CSA nanoparticles could be a promising carrier for drug delivery.

2-Deoxyglucose-Modified Folate Derivative: Self-Assembling Nanoparticle Able to Load Cisplatin

Folic acid has been widely introduced into nano-drug delivery systems to give nanoparticle-targeted characteristics. However, the poor water solubility of folic acid may hinder the exploitation of its ability to load antineoplastic drugs. In the present study, we designed a new folate derivative (FA-2-DG) synthesized from folic acid and 2-Deoxyglucose (2-DG). The aim of this study was to evaluate the self-assembly characteristics of FA-2-DG, and its ability of loading cisplatin. The critical micelle concentration was 7.94 × 10^-6 mol L^-1. Fourier transform infrared spectroscopy indicated that hydrogen bonding interaction is a main driving force for the self⁻assembly of FA-2-DG. The particle was stable in pure water or 0.5% bovine serum albumin dispersions. By forming a coordination bond, the particles assembled from FA-2-DG can load cisplatin. The loading efficiency was maximal when the molar ratio of FA-2-DG to cisplatin was 2:1.

Synthesis and characterization of mesoporous magnetic nanocomposites wrapped with chitosan gatekeepers for pH-sensitive controlled release of doxorubicin

Multifunctional nanocarriers based on the Fe₃O₄ nanoparticles core and mesoporous silica shell (mSiO₂) were synthesized for controlled drug release through magnetic targeting and pH-sensitive performances. The developed Fe₃O₄@mSiO₂ nanocarriers exhibited a suitable size (63nm) and good magnetic responsibility, doxorubicin (DOX) could be successfully loaded into the mesoporous of Fe₃O₄@mSiO₂ via electrostatic interaction, and the drug loading content and loading efficiency are 29.3% and 93.6%, respectively. The chitosan (CS) was employed to wrap the Fe₃O₄@mSiO₂-DOX as the blocking agent to inhibit premature drug release, and the final CS/Fe₃O₄@mSiO₂-DOX exhibited excellent pH-sensitivity, 86.1% DOX was released within 48h at pH4.0. Furthermore, all the release behaviors fit the Higuchi model very well and a purely diffusion-controlled process played a major role on DOX release from CS/Fe₃O₄@mSiO₂-DOX. In addition, MTT assays in human liver hepatocellular carcinoma cells (HepG2) demonstrated that the CS/Fe₃O₄@mSiO₂-DOX had high anti-tumor activity, while the Fe₃O₄@mSiO₂ nanocarriers were practically non-toxic. Thus, our results revealed that the CS/Fe₃O₄@mSiO₂-DOX could play an important role in the development of intracellular delivery nanodevices for cancer therapy.

Correction: Preparation, Characterization and Evaluation of α-Tocopherol Succinate-Modified Dextran Micelles as Potential Drug Carriers. Materials 2015, 8, 6685-6696

The authors wish to make the following correction to their paper [1]. [...].