Rapamycin loaded magnetic Fe3O4/carboxymethylchitosan nanoparticles as tumor-targeted drug delivery system: Synthesis and in vitro characterization

Guidelines for the role of autophagy in drug delivery vectors uptake pathways

The process of autophagy refers to the intracellular absorption of cytoplasm (such as proteins, nucleic acids, tiny molecules, complete organelles, and so on) into the lysosome, followed by the breakdown of that cytoplasm. The majority of cellular proteins are degraded by a process called autophagy, which is both a naturally occurring activity and one that may be induced by cellular stress. Autophagy is a system that can save cells' integrity in stressful situations by restoring metabolic basics and getting rid of subcellular junk. This happens as a component of an endurance response. This mechanism may have an effect on disease, in addition to its contribution to the homeostasis of individual cells and tissues as well as the control of development in higher species. The main aim of this study is to discuss the guidelines for the role of autophagy in drug delivery vector uptake pathways. In this paper, we discuss the meaning and concept of autophagy, the mechanism of autophagy, the role of autophagy in drug delivery vectors, autophagy-modulating drugs, nanostructures for delivery systems of autophagy modulators, etc. Later in this paper, we talk about how to deliver chemotherapeutics, siRNA, and autophagy inducers and inhibitors. We also talk about how hard it is to make a drug delivery system that takes nanocarriers' roles as autophagy modulators into account.

Bioproperties, Nanostructured System and Analytical and Bioanalytical Methods for Determination of Rapamycin: A Review

The drug rapamycin is a potent inhibitor of the mTOR complex, acting directly in the signaling cascade of this protein complex; interrupting cell proliferation, in addition to being an extremely efficient immunosuppressant. Currently this drug is being used in several types of cancer. Rapamycin has been a target of great interest within nanomedicine involving nanostructured systems for drug delivery aiming to increase the bioactivity and bioavailability of this drug. In addition, there is a constant search for analytical methods to identify and quantify this drug. Numerous high-performance liquid chromatography analytical techniques, mass spectrometry and immunoassay techniques have been employed efficiently in an attempt to develop increasingly sensitive analytical methods. Thus, this review sought to bring together current and relevant scientific works involving rapamycin and; besides analytical methods more used for quantification of this molecule.

Novel Methacrylate-Based Multilayer Nanofilms with Incorporated FePt-Based Nanoparticles and the Anticancer Drug 5-Fluorouracil for Skin Cancer Treatment

Despite medical advances, skin-associated disorders continue to pose a unique challenge to physicians worldwide. Skin cancer is one of the most common forms of cancer, with more than one million new cases reported each year. Currently, surgical excision is its primary treatment; however, this can be impractical or even contradictory in certain situations. An interesting potential alternative could lie in topical treatment solutions. The goal of our study was to develop novel multilayer nanofilms consisting of a combination of polyhydroxyethyl methacrylate (PHEMA), polyhydroxypropyl methacrylate (PHPMA), sodium deoxycholate (NaDOC) with incorporated superparamagnetic iron–platinum nanoparticles (FePt NPs), and the potent anticancer drug (5-fluorouracil), for theranostic skin cancer treatment. All multilayer systems were prepared by spin-coating and characterised by atomic force microscopy, infrared spectroscopy, and contact angle measurement. The magnetic properties of the incorporated FePt NPs were evaluated using magnetisation measurement, while their size was determined using transmission electron microscopy (TEM). Drug release performance was tested in vitro, and formulation safety was evaluated on human-skin-derived fibroblasts. Finally, the efficacy for skin cancer treatment was tested on our own basal-cell carcinoma cell line.

Advanced metal and carbon nanostructures for medical, drug delivery and bio-imaging applications

Nanoparticles (NPs) offer great promise for biomedical, environmental, and clinical applications due to their several unique properties as compared to their bulk counterparts. In this review article, we overview various types of metal NPs and magnetic nanoparticles (MNPs) in monolithic form as well as embedded into polymer matrices for specific drug delivery and bio-imaging fields. The second part of this review covers important carbon nanostructures that have gained tremendous attention recently in such medical applications due to their ease of fabrication, excellent biocompatibility, and biodegradability at both cellular and molecular levels for phototherapy, radio-therapeutics, gene-delivery, and biotherapeutics. Furthermore, various applications and challenges involved in the use of NPs as biomaterials are also discussed following the future perspectives of the use of NPs in biomedicine. This review aims to contribute to the applications of different NPs in medicine and healthcare that may open up new avenues to encourage wider research opportunities across various disciplines.

Design, synthesis, and antitumor activity of PLGA nanoparticles incorporating a discovered benzimidazole derivative as EZH2 inhibitor

PURPOSE

Targeting enhancer of zeste homolog 2 (EZH2) can represent a hopeful strategy for oncotherapy. Also, the use of PLGA-based nanoparticles as a novel and rate-controlling carrier system was of our concern.

METHODS

Benzimidazole derivatives were synthesized, and their structures were clarified. In vitro antitumor activity was evaluated. Then, a modeling study was performed to investigate the ability of the most active compounds to recognize EZH2 active sites. Compound 30 (Drug) was selected to conduct pre-formulation studies and then it was incorporated into polymeric PLGA nanoparticles (NPs). NPs were then fully characterized to select an optimized formula (NP₄) that subjected to further evaluation regarding antitumor activity and protein expression levels of EZH2 and EpCAM.

RESULTS

The results showed the antitumor activity of some synthesized derivatives. Docking outcomes demonstrated that Compound 30 was able to identify EZH2 active sites. NP₄ exhibited promising findings and proved to keep the antitumor activity of Compound 30. HEPG-2 was the most sensitive for both Drug and NP₄. Protein analysis indicated that Drug and NP₄ had targeted EZH2 and the downstream signaling pathway leading to the decline of EpCAM expression.

CONCLUSIONS

Targeting EZH2 by Compound 30 has potential use in the treatment of cancer especially hepatocellular carcinoma.

Targeted Delivery of Erythropoietin Hybridized with Magnetic Nanocarriers for the Treatment of Central Nervous System Injury: A Literature Review

Although the incidence of central nervous system injuries has continued to rise, no promising treatments have been elucidated. Erythropoietin plays an important role in neuroprotection and neuroregeneration as well as in erythropoiesis. Moreover, the current worldwide use of erythropoietin in the treatment of hematologic diseases allows for its ready application in patients with central nervous system injuries. However, erythropoietin has a very short therapeutic time window (within 6–8 hours) after injury, and it has both hematopoietic and nonhematopoietic receptors, which exhibit heterogenic and phylogenetic differences. These differences lead to limited amounts of erythropoietin binding to in situ erythropoietin receptors. The lack of high-quality evidence for clinical use and the promising results of in vitro/in vivo models necessitate fast targeted delivery agents such as nanocarriers. Among current nanocarriers, noncovalent polymer-entrapping or polymer-adsorbing erythropoietin obtained by nanospray drying may be the most promising. With the incorporation of magnetic nanocarriers into an erythropoietin polymer, spatiotemporal external magnetic navigation is another area of great interest for targeted delivery within the therapeutic time window. Intravenous administration is the most readily used route. Manufactured erythropoietin nanocarriers should be clearly characterized using bioengineering analyses of the in vivo size distribution and the quality of entrapment or adsorption. Further preclinical trials are required to increase the therapeutic bioavailability (in vivo biological identity alteration, passage through the lung capillaries or the blood brain barrier, and timely degradation followed by removal of the nanocarriers from the body) and decrease the adverse effects (hematological complications, neurotoxicity, and cytotoxicity), especially of the nanocarrier.

Bioproperties, Nanostructured System and Analytical and Bioanalytical Methods for Determination of Rapamycin: A Review

The drug rapamycin is a potent inhibitor of the mTOR complex, acting directly in the signaling cascade of this protein complex; interrupting cell proliferation, in addition to being an extremely efficient immunosuppressant. Currently this drug is being used in several types of cancer. Rapamycin has been a target of great interest within nanomedicine involving nanostructured systems for drug delivery aiming to increase the bioactivity and bioavailability of this drug. In addition, there is a constant search for analytical methods to identify and quantify this drug. Numerous high-performance liquid chromatography analytical techniques, mass spectrometry and immunoassay techniques have been employed efficiently in an attempt to develop increasingly sensitive analytical methods. Thus, this review sought to bring together current and relevant scientific works involving rapamycin and; besides analytical methods more used for quantification of this molecule.

One-Step Synthesis of Metal-Modified Nanomagnetic Materials and Their Application in the Removal of Chlortetracycline

Magnetic nanomaterials are promising heterogeneous catalysts for environmental applications. According to X-ray diffraction, Brunauer-Emmett-Teller method, scanning electron microscopy, high-resolution transmission electron microscopy, and vibrating-sample magnetometer, a kind of copper-modified nanomagnetic material (Cu-nFe₃O₄) was successfully prepared by a one-step synthesis method. Among them, compared with the two-step synthesis method of Cu/Fe₃O₄ and Cu/nFe₃O₄, Cu-nFe₃O₄ has the best effect on chlortetracycline (CTC) removal. The batch study results indicate that the maximum removal of chlortetracycline is 99.0% at a dosage = 2.0 g L^-1, copper loading = 0.8 mM, and C ₀ = 100 mg L^-1 at the optimum conditions within 90 min. The effects of humic acids (HA), NO₃ ^-, Cl^-, CO₃ ^2-, and PO₄ ^3- on the CTC removal by Cu-nFe₃O₄ are also investigated. Repeated experiments were performed on the prepared Cu-nFe₃O₄, indicating that Cu-nFe₃O₄ has good recyclability. The kinetics of the Cu-nFe₃O₄ removal of CTC was investigated, indicating that the reaction conformed to the double constant model and the reaction is mainly dominated by a chemical reaction with physical adsorption. Finally, the mechanism of the CTC removal by Cu-nFe₃O₄ in a heterogeneous environment was clarified. This study aims to provide an experimental basis for the environmental application of Cu-nFe₃O₄.

Graphene oxide-based magnetic nanocomposites for the delivery of melittin to cervical cancer HeLa cells

Melittin (MEL), the primary active component of bee venom, has recently emerged as a promising cancer chemotherapeutic agent. However, the instability and rapid degradation of MEL is a significant challenge in practical therapeutic applications. In the present study, graphene oxide (GO)-based magnetic nanocomposites (PEG-GO-Fe₃O₄) were prepared and adopted as the drug delivery vehicles of MEL, and the anticancer effects of PEG-GO-Fe₃O₄/MEL complexes on human cervical cancer HeLa cells were studied. PEG-GO-Fe₃O₄ exhibited a series of unique physical and chemical properties resulting in multiple interactions with MEL, and ultimately the release of MEL. In vitro experiments showed that PEG-GO-Fe₃O₄/MEL not only distinctly enhanced the inhibition effect on HeLa cells, but also induced pore formation in the cell membrane that ultimately led to cell lysis. In this newly developed drug delivery system, PEGylated GO plays the role of a MEL protector while Fe₃O₄ nanoparticles act as magnetic responders; therefore active MEL can be released over a long period of time (up to 72 h) and maintain its inhibition effect on HeLa cells.

Silk Fibroin as a Coating Polymer for Sirolimus-Eluting Magnesium Alloy Stents

Magnesium (Mg) alloy-based, bioresorbable scaffolding is a promising candidate for next-generation stents. Rapid corrosion of Mg alloy in the physiological environment, however, hinders its clinical application. Hydrofluoric acid (HF) treatment and biodegradable polymer coating have been widely reported to enhance corrosion resistance of the Mg alloy. Poor biocompatibility of biodegradable polymers, however, is known to promote adverse events such as intimal hyperplasia and thrombosis. We selected silk fibroin (SF) as the polymer for stent coating and evaluated drug release from the SF layer, corrosion resistance of the Mg alloy, and biocompatibility. After the stent was coated with SF, ethanol treatment of the SF layer enriched the β-sheet content. Release of sirolimus (SRL), a drug that prevents intimal hyperplasia, from the SF layer was slower than that with a poly(ε-caprolactone), the conventional biodegradable polymer used on medical devices. Ethanol treatment of the SF-coated stent further slowed SRL release from the SF layer. Crystalline domains in SF formed by the β-sheet structure could contribute to the slow release of SRL. The SF coating suppressed local and deep corrosion of the Mg alloy stent, although total corrosion remained unaffected. Uniform corrosion without local or deep corrosion prolongs the stent's radial strength. The SF coating showed excellent biocompatibility with human umbilical vein endothelial cells and minimal platelet adhesion. SF is expected to replace traditional biodegradable polymers for use on bioresorbable stents.

Spinel ferrite nanoparticles and nanocomposites for biomedical applications and their toxicity

This review focuses on the biomedical applications and toxicity of spinel ferrite nanoparticles (SFNPs) with more emphasis on the recently published work. A critical review is provided on recent advances of SFNPs applications in biomedical areas. The novelty of SFNPs in addressing the bottleneck problems encountered in the areas of health; in particular, for diagnosis and treatment of tumour cells are well reviewed. Furthermore, research gaps, toxicity of SFNPs and areas which still need more attention are highlighted. Based on the result of this review, the SFNPs have unlimited capacity in cancer treatment, disease diagnosis, magnetic resonance imaging, drug delivery and release. Overall, stepping out of the conventional way of treatment is difficult but also essential in bringing long lasting solution for cancer and other diseases treatment. In fact, the toxicity study and commercialisation of the SFNPs based cancer treatment options are the main challenges and need further study, in order to reduce unforeseen consequences.

Autophagy Modulators: Mechanistic Aspects and Drug Delivery Systems

Autophagy modulation is considered to be a promising programmed cell death mechanism to prevent and cure a great number of disorders and diseases. The crucial step in designing an effective therapeutic approach is to understand the correct and accurate causes of diseases and to understand whether autophagy plays a cytoprotective or cytotoxic/cytostatic role in the progression and prevention of disease. This knowledge will help scientists find approaches to manipulate tumor and pathologic cells in order to enhance cellular sensitivity to therapeutics and treat them. Although some conventional therapeutics suffer from poor solubility, bioavailability and controlled release mechanisms, it appears that novel nanoplatforms overcome these obstacles and have led to the design of a theranostic-controlled drug release system with high solubility and active targeting and stimuli-responsive potentials. In this review, we discuss autophagy modulators-related signaling pathways and some of the drug delivery strategies that have been applied to the field of therapeutic application of autophagy modulators. Moreover, we describe how therapeutics will target various steps of the autophagic machinery. Furthermore, nano drug delivery platforms for autophagy targeting and co-delivery of autophagy modulators with chemotherapeutics/siRNA, are also discussed.

Protoporphyrin IX-loaded laminarin nanoparticles for anticancer treatment, their cellular behavior, ROS detection, and animal studies

Laminarin conjugate-based nano-scaled particles were in this study proposed as a delivery system for protoporphyrin IX (Pp IX) in photodynamic therapy (PDT) of human breast cancer cells (MCF-7). Hematin-Laminarin-Dithiodipropionic Acid-MGK, named as HLDM, was an amphiphilic carrier material with dual pH/redox sensitive that could be used to load hydrophobic drug to improve their solubility and enhance biocompatibility. Therefore, we combined photosensitizer (Pp IX) with HLDM to fabricate a novel nano-micelles, herein called Pp IX-loaded HLDM micelles. The Pp IX-loaded HLDM micelles were 149.3 ± 35 nm sized in neutral water. Phototoxicity, in vitro PDT effect, and dual sensibility to pH and redox microenvironment of Pp IX-loaded HLDM micelles were examined at different concentrations by using MCF-7 human breast cancer cells. The experiments on phototoxicity and reactive oxygen species (ROS) production proved that the micelles could produce PDT to kill the cancer cells with a certain wavelength light. The apoptosis experiment indicated that the micelles could cause nuclear damage. In vivo PDT effect of the micelles was studied by constructing the tumor-bearing nude mouse model of MCF-7 cells. In vivo studies showed that the Pp IX-loaded HLDM micelles could induce remarkable anti-tumor effect. A promising laminarin-based nanomedicine platform acts as a new drug delivery system to enhance the uptake, accumulation, and PDT efficacy of Pp IX in vitro and in vivo.

Magnetic nanoparticles-loaded liposomes as a novel treatment agent for iron deficiency anemia: In vivo study

Iron deficiency anemia (IDA) is a major worldwide public health problem. This is due to its prevalence among infants, children, adolescents, pregnant and reproductive age women. Ferrous sulfate (FeSO₄) is the first line therapy for iron IDA. Unfortunately, it is reported that FeSO₄ suffers from low absorption rate in the body and itself exhibits severe side effects. Herein, iron oxide magnetic nanoparticles-loaded liposomes (LMNPs) are prepared, characterized and evaluated as a treatment regimen for IDA in Wistar rats (as an animal model). Iron oxide magnetic nanoparticles (MNPs) are prepared and loaded into liposomes using the thin film hydration method. The size of the prepared formulations is in the range 10-100 nm, thus it can avoid the reticular endothelial system (RES), and increased their blood circulation time. For in vivo assessment, thirty-five Wistar rats are divided into 5 groups (n = 7): negative control group, positive control group, and three groups treated with different iron formulations (FeSO₄, MNPs and LMNPs). Anemia is induced in the anemic groups by the bleeding method and then treatment started with different iron compounds administrated orally for 13 days. Hematological parameters are followed up during the treatment period. Results indicate that, in the LMNPs group, the hematological parameters turn to normal values and the histopathological structures of the liver, spleen and kidney remain normal. This proves that liposome increases the bioavailability of MNPs. In conclusion, LMNPs demonstrate superiority as a therapeutic regimen for the treatment of IDA among the tested iron formulations.

A Dual Targeting Magnetic Nanoparticle for Human Cancer Detection

Malignant tumors are a major threat to human life and high lymphatic vessel density is often associated with metastatic tumors. With the discovery of molecules targeted at the lymphatic system such as lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) and Podoplanin, many studies have been performed to determine the role of lymphatic endothelial cells (LECs) in tumor metastasis. However, disadvantages such as non-specificity and high cost limit their research and diagnostic applications. In this study, Fe₃O₄@KCTS, a core-shell type of magnetic nanoparticles, was prepared by activating Fe₃O₄ with carbodiimide and cross-linking it with α-ketoglutarate chitosan (KCTS). The LYVE-1 and Podoplanin antibodies were then incorporated onto the surface of these magnetic nanoparticles and as a result, dual-targeting magnetic nanoprobes were developed. The experimental tests of this study demonstrated that a dual-targeting magnetic nanoprobe with high-purity LECs from tumor tissues was successfully developed, providing a basis for clinical application of LECs in colorectal cancer treatment as well as in early clinical diagnosis using bimodal imaging.

Toxicity and in vivo release profile of sirolimus from implants into the vitreous of rabbits' eyes

PURPOSE

To assess the in vivo release profile and the retinal toxicity of a poly (lactic-co-glycolic acid) (PLGA) sustained-release sirolimus (SRL) intravitreal implant in normal rabbit eyes.

METHODS

PLGA intravitreal implants containing or not SRL were prepared, and the viability of ARPE-19 and hES-RPE human retinal cell lines was examined after 24 and 72 h of exposure to implants. New Zealand rabbits were randomly divided into two groups that received intravitreal implants containing or not SRL. At each time point (1-8 weeks), four animals from the SRL group were euthanized, the vitreous was collected, and drug concentration was calculated. Clinical evaluation of the eyes was performed weekly for 8 weeks after administration. Electroretinography (ERG) was recorded in other eight animals, four for each group, at baseline and at 24 h, 1, 4, 6, and 8 weeks after the injection. ERG was carried out using scotopic and photopic protocols. The safety of the implants was assessed using statistical analysis of the ERG parameters (a and b waves, a and b implicit time, B/A ratio, oscillatory potential, and Naka-Rushton analysis) comparing the functional integrity of the retina between the PLGA and SRL-PLGA groups. After the last electrophysiological assessment, the rabbits were euthanized and retinal histopathology was realized.

RESULTS

After 24 and 72 h of incubation with PLGA or SRL-PLGA implants, ARPE-19 and hES-RPE cells showed viability over 70%. The maximum concentration of SRL (199.8 ng/mL) released from the device occurred within 4 weeks. No toxic effects of the implants or increase in the intraocular pressure was observed through clinical evaluation of the eye. ERG responses showed no significant difference between the eyes that received PLGA or SRL-PLGA implants at baseline and throughout the 8 weeks of follow-up. No remarkable difference in retinal histopathology was detected in rabbit eyes treated with PLGA or SRL-PLGA implants.

CONCLUSIONS

Intravitreal PLGA or SRL-PLGA implants caused no significant reduction in cell viability and showed no evident toxic effect on the function or structure of the retina of the animals. SRL was released from PLGA implant after application in the vitreous of rabbits during 8 weeks.

Fabrication and Cytotoxicity of Gemcitabine-Functionalized Magnetite Nanoparticles

Nanotechnology has been successfully used for the fabrication of targeted anti-cancer drug carriers. This study aimed to obtain Fe₃O₄ nanoparticles functionalized with Gemcitabine to improve the cytotoxic effects of the chemotherapeutic substance on cancer cells. The (un) functionalized magnetite nanoparticles were synthesized using a modified co-precipitation method. The nanoconjugate characterization was performed by XRD, SEM, SAED and HRTEM; the functionalizing of magnetite with anti-tumor substances has been highlighted through TGA. The interaction with biologic media has been studied by means of stability and agglomeration tendency (using DLS and Zeta Potential); also, the release kinetics of the drug in culture media was evaluated. Cytotoxicity of free-Gemcitabine and the obtained nanoconjugate were evaluated on human BT 474 breast ductal carcinoma, HepG2 hepatocellular carcinoma and MG 63 osteosarcoma cells by MTS. In parallel, cellular morphology of these cells were examined through fluorescence microscopy and SEM. The localization of the nanoparticles related to the cells was studied using SEM, EDX and TEM. Hemolysis assay showed no damage of erythrocytes. Additionally, an in vivo biodistribution study was made for tracking where Fe₃O₄@Gemcitabine traveled in the body of mice. Our results showed that the transport of the drug improves the cytotoxic effects in comparison with the one produced by free Gemcitabine for the BT474 and HepG2 cells. The in vivo biodistribution test proved nanoparticle accumulation in the vital organs, with the exception of spleen, where black-brown deposits have been found. These results indicate that our Gemcitabine-functionalized nanoparticles are a promising targeted system for applications in cancer therapy.

Controlled release of vancomycin from 3D porous graphene-based composites for dual-purpose treatment of infected bone defects

A vancomycin-loaded reduced graphene oxide/nano-hydroxyapatite (RGO–nHA) 3D porous composite for eradication of bone infection and facilitation of bone regeneration.

Local in vitro delivery of rapamycin from electrospun PEO/PDLLA nanofibers for glioblastoma treatment

Rapamycin, a mammalian target of rapamycin inhibitor and anti-proliferative agent, is used to treat glioma and other malignancies, but its effectiveness is limited by the fact that it cannot be delivered in a targeted manner to the site of the tumor. To address this issue, we fabricated a mesh via electrospinning using two biodegradable materials, poly(lactic acid) (PLA) and polyethylene oxide (PEO) as a carrier for rapamycin delivery to the tumor. Nanofiber diameter decreased with increasing PLA concentration in the mixed solution. Scanning electron microscopy analysis revealed the smooth and uniform surface morphology of hybrid fibers. Fourier transform infrared spectroscopy analysis demonstrated that rapamycin was encapsulated in the polymer solution; encapsulation efficiency was high and stable over the range of drug concentrations from 0.5-2wt%. A correlation was observed between sustained release of the drug in vitro and cytotoxicity in cultured glioma cells. These results indicate that the PEO/poly(d,l-lactic acid) nanofiber mesh can be used as a targeted delivery system for rapamycin that can limit side effects and prevent locoregional recurrence following surgical resection of glioma.

Nanosystems: the use of nanoalloys, metallic, bimetallic, and magnetic nanoparticles in biomedical applications

There is a growing interest in the use of nanosystems such as nanoalloys, bimetallic nanoparticles, metallic nanoparticles and magnetic nanoparticles in biomedical applications. These applications can be as diverse as hyperthermic treatments; targeted drug delivery; bio-imaging; cell labelling and gene delivery. The use of nanoalloys in these applications has received only limited attention due to the fact that there were many unanswered questions and concerns regarding nanoparticles and nanoalloys such as their stability over time, tendency to agglomerate, chemical activity, ease of oxidation, biocompatibility and cytotoxicity. In this chapter we survey current applications and advances in magnetic nanoparticles used in these biomedical applications so as to understand the materials properties that can pave the way for the use of nanoalloys as a potential alternative or improve solutions that are offered by current materials.