Folic acid-conjugated iron oxide porous nanorods loaded with doxorubicin for targeted drug delivery

Shape Anisotropy-Governed High-Performance Nanomagnetosol for In Vivo Magnetic Particle Imaging of Lungs

Caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), coronavirus disease 2019 (COVID-19) has shown extensive lung manifestations in vulnerable individuals, putting lung imaging and monitoring at the forefront of early detection and treatment. Magnetic particle imaging (MPI) is an imaging modality, which can bring excellent contrast, sensitivity, and signal-to-noise ratios to lung imaging for the development of new theranostic approaches for respiratory diseases. Advances in MPI tracers would offer additional improvements and increase the potential for clinical translation of MPI. Here, a high-performance nanotracer based on shape anisotropy of magnetic nanoparticles is developed and its use in MPI imaging of the lung is demonstrated. Shape anisotropy proves to be a critical parameter for increasing signal intensity and resolution and exceeding those properties of conventional spherical nanoparticles. The 0D nanoparticles exhibit a 2-fold increase, while the 1D nanorods have a > 5-fold increase in signal intensity when compared to VivoTrax. Newly designed 1D nanorods displayed high signal intensities and excellent resolution in lung images. A spatiotemporal lung imaging study in mice revealed that this tracer offers new opportunities for monitoring disease and guiding intervention.

Exploring the Paradigm of Phyto-Nanofabricated Metal Oxide Nanoparticles: Recent Advancements, Applications, and Challenges

The development of nanotechnology, in particular metal oxide nanoparticles, has captured immense scientific attention in the global arena due to their unique properties leading to their unique diverse applications. But the use of toxic precursors and high operational cost make existing methodologies inefficient for synthesising metal oxide nanoparticles (MONPs). Biogenic synthesis of MONPs has been hailed as a more sustainable approach for the synthesis of NPs due to its alignment with the principles of green chemistry. Microorganisms (bacteria, yeast, algae), animal sources (silk, fur, etc.), and plants are effective, low-cost, and eco-friendly means of synthesizing MONPs since they possess a high bio-reduction abilities to produce NPs of various shapes and sizes. The current review encompasses recent advancements in the field of plant-mediated MONP synthesis and characterisation. The detailed evaluation of various synthesis processes and parameters, key influencing factors affecting the synthesis efficiency and product morphology, practical applications with insight into the associated limitations and challenges presents a valuable database that will be helpful in developing alternative prospects and potential engineering applications.

Advances with metal oxide-based nanoparticles as MDR metastatic breast cancer therapeutics and diagnostics

Metal oxide nanoparticles have attracted increased attention due to their emerging applications in cancer detection and therapy. This study envisioned to highlight the great potential of metal oxide NPs due to their interesting properties including high payload, response to magnetic field, affluence of surface modification to overcome biological barriers, and biocompatibility. Mammogram, ultrasound, X-ray computed tomography (CT), MRI, positron emission tomography (PET), optical or fluorescence imaging are used for breast imaging. Drug-loaded metal oxide nanoparticle delivered to the breast cancer cells leads to higher drug uptake. Thus, enhanced the cytotoxicity to target cells compared to free drug. The drug loaded metal oxide nanoparticle formulations hold great promise to enhance efficacy of breast cancer therapy including multidrug resistant (MDR) and metastatic breast cancers. Various metal oxides including magnetic metal oxides and magnetosomes are of current interests to explore cancer drug delivery and diagnostic efficacy especially for metastatic breast cancer. Metal oxide-based nanocarrier formulations are promising for their usage in drug delivery and release to breast cancer cells, cancer diagnosis and their clinical translations.

Biomarker targeted therapy approaches for TNBC using metal oxide-based NPs are highly effective and promising.

Endogenous reactive oxygen species burst induced and spatiotemporally controlled multiple drug release by traceable nanoparticles for enhancing antitumor efficacy

Reactive oxygen species (ROS) are not only used as a therapeutic reagent in chemodynamic therapy (CDT), to stimulate the release of antineoplastic drugs, they can also be used to achieve a combined effect of CDT and chemotherapy to enhance anticancer effects. Herein, we synthesized a pH-responsive prodrug (PEG2k-NH-N-DOX), ROS-responsive prodrug (PEG2k-S-S-CPT-ROS), organic CDT agents (TPP-PEG2k-LND, TPP-PEG2k-TOS), and T1-enhanced magnetic resonance imaging contrast agents (Gd-DTPA-N16-16), and used them to encapsulate combrestatinA4 (CA4) to prepare traceable pH/ROS dual-responsive multifunctional nanoparticles (TLDCAG NPs) with endogenous ROS burst and spatiotemporally controlled multiple drug release ability. Firstly, TLDCAG NPs were accumulated in the tumor cell microenvironment via an enhanced permeability and retention (EPR) effect. Secondly, CA4 was released and specifically destroyed angiogenesis to facilitate the interaction between the tumor and the remaining TLDCG NPs. After accumulating in tumor cells, the TLDCG NPs could be destroyed under acidic conditions to quickly release doxorubicin (DOX), TPP-PEG2k-LND, and TPP-PEG2k-TOS. Thirdly, TPP-PEG2k-LND and TPP-PEG2k-TOS quickly targeted mitochondria, induced endogenous ROS bursts, reduced the mitochondrial membrane potential, and induced tumor cell apoptosis. Endogenous ROS can not only be used as a therapeutic reagent for CDT, but also can cut off the thioketal bond in PEG2k-S-S-CPT-ROS and release camptothecin (CPT). Finally, TLDCAG NPs were traced by magnetic resonance imaging (MRI). Furthermore, in vitro and vivo results indicate that the TLDCAG NPs have vigorous antitumor activity and negligible systemic toxicity. Therefore, the TLDCAG NPs provide an efficient strategy for enhancing antitumor efficacy.

Metal Oxide Nanoparticles as Biomedical Materials

The development of new nanomaterials with high biomedical performance and low toxicity is essential to obtain more efficient therapy and precise diagnostic tools and devices. Recently, scientists often face issues of balancing between positive therapeutic effects of metal oxide nanoparticles and their toxic side effects. In this review, considering metal oxide nanoparticles as important technological and biomedical materials, the authors provide a comprehensive review of researches on metal oxide nanoparticles, their nanoscale physicochemical properties, defining specific applications in the various fields of nanomedicine. Authors discuss the recent development of metal oxide nanoparticles that were employed as biomedical materials in tissue therapy, immunotherapy, diagnosis, dentistry, regenerative medicine, wound healing and biosensing platforms. Besides, their antimicrobial, antifungal, antiviral properties along with biotoxicology were debated in detail. The significant breakthroughs in the field of nanobiomedicine have emerged in areas and numbers predicting tremendous application potential and enormous market value for metal oxide nanoparticles.

Shape Anisotropic Iron Oxide-Based Magnetic Nanoparticles: Synthesis and Biomedical Applications

Research on iron oxide-based magnetic nanoparticles and their clinical use has been, so far, mainly focused on the spherical shape. However, efforts have been made to develop synthetic routes that produce different anisotropic shapes not only in magnetite nanoparticles, but also in other ferrites, as their magnetic behavior and biological activity can be improved by controlling the shape. Ferrite nanoparticles show several properties that arise from finite-size and surface effects, like high magnetization and superparamagnetism, which make them interesting for use in nanomedicine. Herein, we show recent developments on the synthesis of anisotropic ferrite nanoparticles and the importance of shape-dependent properties for biomedical applications, such as magnetic drug delivery, magnetic hyperthermia and magnetic resonance imaging. A brief discussion on toxicity of iron oxide nanoparticles is also included.

Effects of Lignin-Based Hollow Nanoparticle Structure on the Loading and Release Behavior of Doxorubicin

Because of their exceptional absorption capacity, biodegradability, and nontoxicity, nanomaterials fabricated from renewable natural resources have recently become an increasingly important research area. However, the mechanism of drug encapsulation by lignin nanoparticles and the role of nanoparticle structure on the stability and loading performance still remain unknown. Herein, lignin hollow nanoparticles (LHNPs) were prepared and applied as promising vehicles for the antineoplastic antibiotic drug doxorubicin hydrochloride (DOX). The hydrogen bonding and π-π interactions contributed to the encapsulation of hydrophilic DOX by LHNPs with hydrophobic cavities. The encapsulation of DOX was enhanced by the pore volume and surface area. In addition, the nanoparticles contributed to the cellular uptake and the accumulation of the drug within HeLa cells. This work provides a scientific basis for future studies on the selective entrapment properties of hollow polymer nanoparticles derived from biomass material as vehicles for overcoming pharmacokinetic limitations.

Förster Resonance Energy Transfer-Activated Processes in Smart Nanotheranostics Fabricated in a Sustainable Manner

Multilayer nanocarriers loaded with optically activated payloads are gaining increasing attention due to their anticipated crucial role for providing new mechanisms of energy transfers in the health-oriented applications, as well as for energy storage and environmental protection. The combination of careful selection of optical components for efficient Förster resonance energy transfer, and surface engineering of the nanocarriers, allowed us to synthesize and characterize novel theranostic nanosystems for diagnosis and therapy of deep-seated tumors. The cargo, constrained within the oil core of the nanocapsules, composed of NaYF₄ :Tm⁺³ , Yb⁺³ up-converting nanoparticles together with a second-generation porphyrin-based photosensitizing agent-Verteporfin, assured requisite diagnostic and therapeutic functions under near-IR laser excitation. The outer polyaminoacid shell of the nanocapsules was functionalized with a ligand-poly(l-glutamic acid) functionalized by PEG-ylated folic acid-to ensure both a "stealth" effect and active targeting towards human breast cancer cells. The preparation criteria of all nanocarrier building blocks meet the requirements for sustainable and green chemistry practices. The multifunctionality of the proposed nanocarriers is a consequence of both the surface-functionalized organic exterior part, which was accessible for selective accumulation in cancer cells, and the hydrophobic optically active interior, which shows phototoxicity upon irradiation within the first biological window.

Preparation of Targeted Lignin⁻Based Hollow Nanoparticles for the Delivery of Doxorubicin

Due to their exceptional absorption capacity, biodegradability, and non-toxicity, nanoparticles (NPs) from lignin have emerged as vehicles for inorganic particles and drug molecules. However, the method for preparing targeted lignin particles is still complex and lacks sufficient research. Herein, a succinct strategy was proposed for the preparation of targeted lignin-based drug delivery NPs to load Doxorubicin Hydrochloride (DOX). The lignin hollow NPs (LHNPs) were used as a platform for the preparation of targeted delivery material by incorporating magnetic NPs and folic acid (FA) via layer-by-layer self-assembling. The results showed that the surface of LHNPs was covered uniformly by Fe₃O₄ NPs and grafted with folic acid. The folic-magnetic-functionalized lignin hollow NPs (FA-MLHNPs) could respond to magnetic field and folic acid receptors. In addition, the targeting performance of the FA-MLHNPs increased the cellular uptake of NPs in the case of HeLa cells. This research not only supported the modified NPs platform as a highly efficient nano-delivery method but also provided a facile approach to utilize renewable lignin biomaterials.

Multi-functional core-shell Fe3O4@Au nanoparticles for cancer diagnosis and therapy

Multi-functional core-shell Fe₃O₄@Au nanoparticles (Fe₃O₄@Au-DOX-mPEG/PEG-FA NPs) conjugated with doxorubicin (DOX), methoxy poly(ethylene glycol) (mPEG), and folic acid-linked poly(ethylene glycol) (PEG-FA) were synthesized for cancer theranostic applications. In the developed NPs, the DOX was chemically conjugated at the surface of core-shell Fe₃O₄@Au NPs using L-cysteine methyl ester (LCME) as a linker by acid-sensitive hydrazone bond. The formation of Fe₃O₄@Au-DOX-mPEG/PEG-FA NPs was confirmed by ¹H-NMR analysis. The TEM image and DLS studies showed that the mean diameter of the prepared NPs was about 18 and 38 nm, respectively. Due to the existence of superparamagnetic Fe₃O₄, the Fe₃O₄@Au-DOX-mPEG/PEG-FA NPs presented the saturation magnetization (Ms) value of 23 emu/g. The developed NPs displayed the maximum amount of drug release in the acidic medium than that in the mild alkaline medium because of the presence of acid-sensitive hydrazone bond. Due to the presence of FA, the Fe₃O₄@Au-DOX-mPEG/PEG-FA NPs displayed the increased cellular uptake through a folate-receptor-mediated endocytosis, which results in the improved cytotoxic effect on the HeLa cells. Under the laser irradiation, the cytotoxicity of Fe₃O₄@Au-DOX-mPEG/PEG-FA NPs was found to be improved due to the photothermal effect of Au shell existing in the NPs. These results reveal that the Fe₃O₄@Au-DOX-mPEG/PEG-FA NPs could be a promising tumour-targeted drug delivery system with the capabilities of combined MR/CT imaging, photothermal, and chemotherapy of tumours.

Synthesis of Distinct Iron Oxide Nanomaterial Shapes Using Lyotropic Liquid Crystal Solvents

A room temperature reduction-hydrolysis of Fe(III) precursors such as FeCl₃ or Fe(acac)₃ in various lyotropic liquid crystal phases (lamellar, hexagonal columnar, or micellar) formed by a range of ionic or neutral surfactants in H₂O is shown to be an effective and mild approach for the preparation of iron oxide (IO) nanomaterials with several morphologies (shapes and dimensions), such as extended thin nanosheets with lateral dimensions of several hundred nanometers as well as smaller nanoflakes and nanodiscs in the tens of nanometers size regime. We will discuss the role of the used surfactants and lyotropic liquid crystal phases as well as the shape and size differences depending upon when and how the resulting nanomaterials were isolated from the reaction mixture. The presented synthetic methodology using lyotropic liquid crystal solvents should be widely applicable to several other transition metal oxides for which the described reduction-hydrolysis reaction sequence is a suitable pathway to obtain nanoscale particles.

Designed synthesis and surface engineering strategies of magnetic iron oxide nanoparticles for biomedical applications

Iron oxide nanoparticles (NPs) hold great promise for future biomedical applications because of their magnetic properties as well as other intrinsic properties such as low toxicity, colloidal stability, and surface engineering capability. Numerous related studies on iron oxide NPs have been conducted. Recent progress in nanochemistry has enabled fine control over the size, crystallinity, uniformity, and surface properties of iron oxide NPs. This review examines various synthetic approaches and surface engineering strategies for preparing naked and functional iron oxide NPs with different physicochemical properties. Growing interest in designed and surface-engineered iron oxide NPs with multifunctionalities was explored in in vitro/in vivo biomedical applications, focusing on their combined roles in bioseparation, as a biosensor, targeted-drug delivery, MR contrast agents, and magnetic fluid hyperthermia. This review outlines the limitations of extant surface engineering strategies and several developing strategies that may overcome these limitations. This study also details the promising future directions of this active research field.

Preparation and in vitro evaluation of 5-flourouracil loaded magnetite-zeolite nanocomposite (5-FU-MZNC) for cancer drug delivery applications

In this work, super paramagnetic magnetite nanoparticles were synthesized onto/into zeolite, then loaded with anti-cancer drug 5-fluorouracil (5-FU). The physical properties of the prepared nanocomposite and drug loaded nanocomposite were characterized using different techniques. The drug loading and releasing behavior of the magnetic nanocarrier was investigated and the drug-loaded nanoparticles exhibited a sustained release of drug without any burst release phenomenon. Furthermore, 5-FU loaded MZNC were evaluated for its biological characteristics. The functional 5-FU-MZNC has been triggered intra-cellular release of the cancer therapeutic agent 5-fluorouracil (5-FU). Cytotoxic effects of 5-FU loaded MZNC on human gastric carcinoma (AGS) cells were determined by real time cell analysis and colorimetric WST-1 cell viability assay. Apoptosis of cells was further investigated by Annexin-V staining which indicates the loss of cell membrane integrity. According to our results, 5-FU-MZNC showed a concentration-dependent cell proliferation inhibitory function against AGS cells. Morphologic and apoptotic images were consistent with the cytotoxicity results. In conclusion, 5-FU loaded MZNC efficiently inhibit the proliferation of AGS cells in vitro through apoptotic mechanisms, and may be a beneficial agent against cancer, however further animal study is still required.

Design of liposomal formulations for cell targeting

Liposomes have gained extensive attention as carriers for a wide range of drugs due to being both nontoxic and biodegradable as they are composed of substances naturally occurring in biological membranes. Active targeting for cells has explored specific modification of the liposome surface by functionalizing it with specific targeting ligands in order to increase accumulation and intracellular uptake into target cells. None of the Food and Drug Administration-licensed liposomes or lipid nanoparticles are coated with ligands or target moieties to delivery for homing drugs to target tissues, cells or subcellular organelles. Targeted therapies (with or without controlled drug release) are an emerging and relevant research area. Despite of the numerous liposomes reviews published in the last decades, this area is in constant development. Updates urgently needed to integrate new advances in targeted liposomes research. This review highlights the evolution of liposomes from passive to active targeting and challenges in the development of targeted liposomes for specific therapies.

Dendrimeric anticancer prodrugs for targeted delivery of ursolic acid to folate receptor-expressing cancer cells: synthesis and biological evaluation

The anticancer efficacy of ursolic acid (UA) was limited by poor water solubility, non-specific tumor distribution, and low bioavailability. To overcome this problem, polyamidoamine (PAMAM) conjugated with UA and folic acid (FA) as novel dendrimeric prodrugs were designed and successfully synthesized by a concise one-pot synthetic approach. Both FA and UA were covalently conjugated to the surface of PAMAM through acid-labile ester bonds and the covalently linked UA could be hydrolysed either in acidic (pH 5.4) or in neutral (pH 7.4) PBS solution. The cellular uptake study indicated that the presence of FA enhanced uptake of the dendrimeric prodrugs in folate receptor (FR) over-expressing Hela cells. The enhanced cellular uptake could be due to the electrostatic absorptive endocytosis and FR-mediated endocytosis. In contrast, for HepG2 cells, a FR-negative cell line, FA conjugation on the surface of the dendrimer showed no effect on the cellular uptake. In MTT assay and cell cycle analysis, FA-modified dendrimeric prodrugs showed significantly enhanced toxicity than non-FA-modified ones in Hela cells. These results suggested that FA-modified dendrimeric UA prodrugs have the potential for targeted delivery of UA into cancer cells to improve its anti-tumor efficacy.

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

A novel tumor-targeted drug delivery system (Fe3O4/CMCS-Rapa NPs) was prepared using magnetic Fe3O4/carboxymethylchitosan nanoparticles (Fe3O4/CMCS NPs) as carrier and rapamycin (Rapa) as the model anti-tumor drug. The morphology, composition, and properties of the Fe3O4/CMCS-Rapa NPs were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), X-ray diffraction (XRD), thermal analysis (TG/DSC), vibration sample magnetometer (VSM), and drug release kinetics, cytotoxicity, cellular uptake, apoptosis studies in vitro. The results showed that the synthesized Fe3O4/CMCS-Rapa NPs were spherical in shape with an average size of 30±2 nm, the saturated magnetization reached 67.1 emu/g, and the loading efficiency of Rapa was approximately 6.32±0.34%. In addition, the in vitro drug release behavior displayed that the Fe3O4/CMCS NPs exhibited a biphasic drug release pattern with initial burst release and consequently sustained release. Furthermore, the Fe3O4/CMCS-Rapa NPs showed lower cytotoxicity to liver cell line (LO2) and comparatively higher cytotoxicity to human hepatocarcinoma cell line (HepG2) than native Rapa. Fe3O4/CMCS-Rapa NPs could enhance cellular uptake and reduce Rapa drug damage to the normal cells so as to improve the curative effect of drug to tumor cells. All these results demonstrated that the Fe3O4/CMCS-Rapa NPs may be useful as a promising candidate for targeted cancer diagnostic and therapy.

Self-assembled liquid-crystalline folate nanoparticles for in vitro controlled release of doxorubicin

Liquid-crystalline folate nanoparticles are ordered in structure which offers several advantages like high encapsulation of drugs, controlled release rates, biocompatible in nature. Moreover, it facilitates the cellular uptake of nanodrugs without any extra step of folate ligand based targeting. The size of these nanocarriers as well as the release profiles of drugs from these nano-carriers can be controlled precisely. Folate molecules self-assemble in ordered stacks and columns even at low concentration of 0.1wt%. Doxorubicin molecules get intercalated within the folate stacks and are developed into nanoparticles. These nanoparticles are composed of highly ordered folate self-assembly which encapsulate doxorubicin molecules. These drug molecules can be released in a controlled manner by disrupting this assembly in the environment of monovalent cations. The ordered structure of folate nanoparticles offers low drug losses of about 4-5%, which is significant in itself. This study reports the size-control method of forming doxorubicin encapsulated folate nanoparticles as well as the parameters to control the release rates of doxorubicin through liquid-crystalline folate nanoparticles. It has been demonstrated that doxorubicin release rates can be controlled by controlling the size of the nanoparticles, cross-linking cation and cross-linking concentration. The effect of different factors like drug loading, release medium, and pH of the medium on doxorubicin release rates was also studied. Moreover, this study also addresses the comparative in vitro cytotoxic performance of Doxorubicin loaded folate nanoparticles and cellular uptake of nano-carriers on cancer and normal cell line.

Self-assembling surfactant-like peptide A6K as potential delivery system for hydrophobic drugs

Background

Finding a suitable delivery system to improve the water solubility of hydrophobic drugs is a critical challenge in the development of effective formulations. In this study, we used A₆K, a self-assembling surfactant-like peptide, as a carrier to encapsulate and deliver hydrophobic pyrene.

Methods

Pyrene was mixed with A₆K by magnetic stirring to form a suspension. Confocal laser scanning microscopy, transmission electron microscopy, dynamic light scattering, atomic force microscopy, fluorescence, and cell uptake measurements were carried out to study the features and stability of the nanostructures, the state and content of pyrene, as well as the pyrene release profile.

Results

The suspension formed contained pyrene monomers trapped in the hydrophobic cores of the micellar nanofibers formed by A₆K, as well as nanosized pyrene crystals wrapped up and stabilized by the nanofibers. The two different encapsulation methods greatly increased the concentration of pyrene in the suspension, and formation of pyrene crystals wrapped up by A₆K nanofibers might be the major contributor to this effect. Furthermore, the suspension system could readily release and transfer pyrene into living cells.

Conclusion

A₆K could be further exploited as a promising delivery system for hydrophobic drugs.

Multilayer fluorescent magnetic nanoparticles with dual thermoresponsive and pH-sensitive polymeric nanolayers as anti-cancer drug carriers

Fluorescent magnetic nanoparticles with dual thermoresponsive and pH-sensitive polymeric nanolayers as anti-cancer drug carriers.

Folic acid-conjugated TiO2-doped mesoporous carbonaceous nanocomposites loaded with Mitoxantrone HCl for chemo-photodynamic therapy

A TiO₂-doped porous carbon drug delivery system was prepared. The ability of this system to combine chemotherapy with photodynamic activity enhanced the cancer cell killing effect.