Rational Design of GO-Modified Fe3O4/SiO2 Nanoparticles with Combined Rhenium-188 and Gambogic Acid for Magnetic Target Therapy

Physiological Microenvironment Dependent Self-Cross-Linking of Multifunctional Nanohybrid for Prolonged Antibacterial Therapy via Synergistic Chemodynamic-Photothermal-Biological Processes

Herein, a multifunctional nanohybrid (PL@HPFTM nanoparticles) was fabricated to perform the integration of chemodynamic therapy, photothermal therapy, and biological therapy over the long term at a designed location for continuous antibacterial applications. The PL@HPFTM nanoparticles consisted of a polydopamine/hemoglobin/Fe2+ nanocomplex with comodification of tetrazole/alkene groups on the surface as well as coloading of antimicrobial peptides and luminol in the core. During therapy, the PL@HPFTM nanoparticles would selectively cross-link to surrounding bacteria via tetrazole/alkene cycloaddition under chemiluminescence produced by the reaction between luminol and overexpressed H2O2 at the infected area. The resulting PL@HPFTM network not only significantly damaged bacteria by Fe2+-catalyzed ROS production, effective photothermal conversion, and sustained release of antimicrobial peptides but dramatically enhanced the retention time of these therapeutic agents for prolonged antibacterial therapy. Both in vitro and in vivo results have shown that our PL@HPFTM nanoparticles have much higher bactericidal efficiency and remarkably longer periods of validity than free antibacterial nanoparticles.

Radiolabeled florescent-magnetic graphene oxide nanosheets: probing the biodistribution of a potential PET-MRI hybrid imaging agent for detection of fibrosarcoma tumor

PURPOSE

Radiolabeled graphene oxide (GO) nanosheets has been one of the most extensively studied nanoplatform for in vivo radioisotope delivery. Herein, we describe the functionalization of the surface of GO nanosheets with Fe3O4 magnetic nanoparticles, cysteine amino acid as an interface ligand, and cadmium telluride quantum dots.

MATERIALS AND METHODS

To enable In vivo PET imaging, the GO@Fe3O4-cys-CdTe QDs were labeled with 68Ga to yield [68Ga] Ga-Go@ Fe3O4-Cys-CdTe QDs. Furthermore, serum stability tests were performed and the biological behavior of the nanocomposite was evaluated in rats bearing fibrosarcoma tumor.

RESULTS

Liver, blood and tumor were the most accumulated sites at 1 h after the injection, and the radiolabeled nanocomposite as a PET/MRI imaging agent showed fast depletion from body and acceptable tumor uptake.

CONCLUSION

Magnetic (Fe3O4) and fluorescent components (CdTe QDs) along with a positron-emitting radionuclide will help to design a multimodal imaging system (PET/MRI/OI) which will offer the advantages of combined imaging techniques and further possible used in localized radionuclide therapy. Overall, [68Ga] Ga-GO@Fe3O4-cys-CdTe QDs nanocomposite shows great promise as a radiolabeled imaging agent owing to high accumulation in tumor region.

Caged Polyprenylated Xanthones in Garcinia hanburyi and the Biological Activities of Them

The previous phytochemical analyses of Garcinia hanburyi revealed that the main structural characteristic associated with its biological activity is the caged polyprenylated xanthones with a unique 4-oxatricyclo [4.3.1.03,7] dec-2-one scaffold, which contains a highly substituted tetrahydrofuran ring with three quaternary carbons. Based on the progress in research of the chemical constituents, pharmacological effects and modification methods of the caged polyprenylated xanthones, this paper presents a preliminary predictive analysis of their drug-like properties based on the absorption, distribution, metabolism, excretion and toxicity (ADME/T) properties. It was found out that these compounds have very similar pharmacokinetic properties because they possess the same caged xanthone structure, the 9,10-double bond in a,b-unsaturated ketones are critical for the antitumor activity. The author believes that there is an urgent need to seek new breakthroughs in the study of these caged polyprenylated xanthones. Thus, the research on the route of administration, therapeutic effect, structural modification and development of such active ingredients is of great interest. It is hoped that this paper will provide ideas for researchers to develop and utilize the active ingredients derived from natural products.

Radiolabelled Extracellular Vesicles as Imaging Modalities for Precise Targeted Drug Delivery

Extracellular vesicles (ECVs) have been abandoned as bio-inspired drug delivery systems (DDS) in the biomedical field. ECVs have a natural ability to cross over extracellular and intracellular barriers, making them superior to manufactured nanoparticles. Additionally, they have the ability to move beneficial biomolecules among far-flung bodily cells. These advantages and the accomplishment of favorable in vivo results convincingly show the value of ECVs in medication delivery. The usage of ECVs is constantly being improved, as it might be difficult to develop a consistent biochemical strategy that is in line with their useful clinical therapeutic uses. Extracellular vesicles (ECVs) have the potential to enhance the therapy of diseases. Imaging technologies, particularly radiolabelled imaging, have been exploited for non-invasive tracking to better understand their in vivo activity.

Manipulation and elimination of circulating tumor cells using multi-responsive nanosheet for malignant tumor therapy

Tumor recurrence caused by metastasis is a major cause of death for patients. Thus, a strategy to manipulate the circulating tumor cells (CTCs, initiators of tumor metastasis ) and eliminate them along with the primary tumor has significant clinical significance for malignant tumor therapy. In this study, a magnet-NIR-pH multi-responsive nanosheet (Fe₃O₄@SiO₂-GO-PEG-FA/AMP-DOX, FGPFAD) was fabricated to capture CTCs in circulation, then magnetically transport them to the primary tumor, and finally perform NIR-dependent photothermal therapy as well as acidic-environment-triggered chemotherapy to destroy both the CTCs and the primary tumor. The FGPFAD nanosheet consists of silica-coated ferroferric oxide nanoparticles (Fe₃O₄@SiO₂, magnetic targeting agent), graphene oxide (GO, photothermal therapy agent), polyethylene glycol (PEG, antifouling agent for sustained circulation), folic acid (FA, capturer of CTCs) and antimicrobial-peptide-conjugated doxorubicin (AMP-DOX, agent for chemotherapy), in which the AMP-DOX was bound to the FGPFAD nanosheet via a cleavable Schiff base to achieve acidic-environment-triggered drug release for tumor-specific chemotherapy. Both in vitro and in vivo results indicated that the effective capture and magnetically guided transfer of CTCs to the primary tumor, as well as the multimodal tumor extermination performed by our FGPFAD nanosheet, significantly inhibited the primary tumor and its metastasis.

Load and release of gambogic acid via dual-target ellipsoidal-Fe3O4@SiO2@mSiO2-C18@dopamine hydrochloride -graphene quantum dots-folic acid and its inhibition to VX2 tumor cells

Ellipsoidal-Fe₃O₄@SiO₂@mSiO₂-C₁₈@dopamine hydrochloride-graphene quantum dots-folic acid (ellipsoidal-HMNPs@PDA-GQDs-FA), a dual-functional drug carrier, was stepwise constructed. Theα-Fe₂O₃ellipsoidal nanoparticles were prepared by a hydrothermal method, and then coated with SiO₂by Stöber method. The resulting core-shell structure, Fe₃O₄@SiO₂@mSiO₂-C₁₈magnetic nano hollow spheres, abbreviated as HMNPs, was finally grafted with graphene quantum dots (GQDs), dopamine hydrochloride (PDA) and folic acid (FA) by amide reaction to obtain HMNPs@PDA-GQDs-FA. Transmission electron microscopy, Fourier transform infrared spectroscopy, fluorescence spectroscopy and element analysis proved the successful construction of the HMNPs@PDA-GQDs-FA nanoscale carrier-cargo composite. The carrier HMNPs@PDA-GQDs-FA has higher load (51.63 ± 1.53%) and release (38.56 ± 1.95%) capacity for gambogic acid (GA). Cytotoxicity test showed that the cell survival rate was above 95%, suggesting the cytotoxicity of the carrier-cargo was very low. The cell lethality (74.91 ± 1.2%) is greatly improved after loading GA because of the magnetic targeting of HMNPs, the targeting performance of FA to tumor cells, and the pH response to the surrounding environment of tumor cells of PDA. All results showed that HMNPs@PDA-GQDs-FA had good biocompatibility and could be used in the treatment of VX2 tumor cells after loading GA.

Thermosensitive and magnetic molecularly imprinted polymers for selective recognition and extraction of aristolochic acid I

Recently, the natural compound of aristolochic acid I (AAI) has attracted wide attentions due to its strong nephrotoxicity and carcinogenicity. However, the extraction of AAI based on conventional molecularly imprinted polymers (MIPs) are tedious with extensive eluent, causing secondary pollution and poor regeneration. Herein, thermosensitive and magnetic MIPs (TMMIPs) were synthesized by a surface imprinting method, which achieved thermosensitive capture/release of AAI, along with rapid magnetic separation, significantly shortening the elution time and reducing organic-solvent consumption. TMMIPs with dual-stimuli responses exhibited superior affinity, selectivity, kinetics, and regeneration ability towards AAI. TMMIPs were applied to analyze AAI in Houttuynia cordata via dispersive solid-phase extraction (d-SPE) coupled with high performance liquid chromatography (HPLC), yielding satisfactory recoveries (79.03-99.67%) and relative standard deviations (≤5.78%). The limit of detection of AAI was as low as 26.67 µg/L. TMMIPs demonstrate great applicability for fast, selective and eco-friendly extraction of AAI in complicated matrices.

The Use of Alternative Strategies for Enhanced Nanoparticle Delivery to Solid Tumors

Nanomaterial (NM) delivery to solid tumors has been the focus of intense research for over a decade. Classically, scientists have tried to improve NM delivery by employing passive or active targeting strategies, making use of the so-called enhanced permeability and retention (EPR) effect. This phenomenon is made possible due to the leaky tumor vasculature through which NMs can leave the bloodstream, traverse through the gaps in the endothelial lining of the vessels, and enter the tumor. Recent studies have shown that despite many efforts to employ the EPR effect, this process remains very poor. Furthermore, the role of the EPR effect has been called into question, where it has been suggested that NMs enter the tumor via active mechanisms and not through the endothelial gaps. In this review, we provide a short overview of the EPR and mechanisms to enhance it, after which we focus on alternative delivery strategies that do not solely rely on EPR in itself but can offer interesting pharmacological, physical, and biological solutions for enhanced delivery. We discuss the strengths and shortcomings of these different strategies and suggest combinatorial approaches as the ideal path forward.

A Nanosensor for Naked-Eye Identification and Adsorption of Cadmium Ion Based on Core-Shell Magnetic Nanospheres

Fe₃O₄@SiO₂ nanospheres with a core-shell structure were synthesized and functionalized with bis(2-pyridylmethyl)amine (BPMA). The photoresponses of the as-obtained Fe₃O₄@SiO₂-BPMA for Cr³⁺, Cd²⁺, Hg²⁺ and Pb²⁺ ions were evaluated through irradiation with a 352 nm ultraviolet lamp, and Fe₃O₄@SiO₂-BPMA exhibited remarkable fluorescence enhancement toward the Cd²⁺ ion. The adsorption experiments revealed that Fe₃O₄@SiO₂-BPMA had rapid and effective adsorption toward the Cd²⁺ ion. The adsorption reaction was mostly complete within 30 min, the adsorption efficiency reached 99.3%, and the saturated adsorption amount was 342.5 mg/g based on Langmuir linear fitting. Moreover, Fe₃O₄@SiO₂-BPMA displayed superparamagnetic properties with the saturated magnetization of 20.1 emu/g, and its strong magnetic sensitivity made separation simple and feasible. Our efforts in this work provide a potential magnetic functionalized nanosensor for naked-eye identification and adsorption toward the Cd²⁺ ion.

Understanding the driving forces of camptothecin interactions on the surface of nanocomposites based on graphene oxide decorated with silica nanoparticles

Camptothecin (CPT) is a potent antitumor drug frequently used in studies of drug delivery systems. The poor water solubility and unfavourable pharmacokinetic conditions of CPT and the development of nanomaterials such as mesoporous silica nanoparticles (MSNs), graphene oxide (GO) and a new family of GO decorated with MSNs (GO-MSNs) motivated the present work, which sought to solve these challenges. In this context, release assays showed rapid and prolonged release, respectively, by silica and GO/GO-MSN nanomaterials; release was faster at pH 7.4 and slower at pH 5.0 in all situations. In particular, GO-MSNs presented an important advantage compared to GO due to their slower drug release at pH 7.4 (physiological conditions in blood; slowest release is expected under these conditions) and faster drug delivery at pH 5.0 (acidic conditions in endosomes of cancer cells; fastest release is expected under these conditions). The results, therefore, present the GO-MSN nanomaterial as a potential candidate for antitumor applications. The main drug-nanocarrier chemical interactions (London forces, hydrogen bonds, and electrostatic and dipole-dipole interactions) are also exhaustively described in order to understand the observed differences in drug delivery properties among these nanomaterials and to comprehend the influence of pH on concomitant and dynamic interactions.

Aminated β-cyclodextrin-grafted Fe3O4-loaded gambogic acid magnetic nanoparticles: preparation, characterization, and biological evaluation

Based on aminated β-cyclodextrin (6-NH₂-β-CD)-grafted Fe₃O₄ and gambogic acid (GA) clathrate complexes, a nanoparticle delivery system was developed with the aim to achieve low irritation, strong targeting, and high bioavailability of a gambogic acid magnetic nanopreparation. 6-NH₂-β-CD grafted onto Fe₃O₄ MNPs was demonstrated by high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, zeta potential, and magnetic measurements. The average particle size of the Fe₃O₄@NH₂-β-CD MNPs was 147.4 ± 0.28 nm and the PDI was 0.072 ± 0.013. The encapsulation efficiency, drug loading, zeta potential, and magnetic saturation values of the Fe₃O₄@NH₂-β-CD MNPs were 85.71 ± 3.47%, 4.63 ± 0.04%, −29.3 ± 0.42 mV, and 46.68 emu g⁻¹, respectively. Compared with free GA, the in vitro release profile of GA from Fe₃O₄@NH₂-β-CD MNPs was characterized by two phases: an initial fast release and a delayed-release phase. The Fe₃O₄@NH₂-β-CD MNPs displayed continuously increased cytotoxicity against HL-60 and HepG2 cell lines in 24 h, whereas the carrier Fe₃O₄@NH₂-β-CD MNPs showed almost no cytotoxicity, indicating that the release of GA from the nanoparticles had a sustained profile and Fe₃O₄@NH₂-β-CD MNPs as a tumor tissue-targeted drug delivery system have great potential. Besides, blood vessel irritation tests suggested that the vascular irritation could be reduced by the use of Fe₃O₄@NH₂-β-CD MNPs encapsulation for GA. The t_1/2 and the AUC of the Fe₃O₄@NH₂-β-CD@GA MNPs were found to be higher than those for the GA solution by approximately 2.71-fold and 2.42-fold in a pharmacokinetic study, respectively. The better biocompatibility and the combined properties of specific targeting and complexation ability with hydrophobic drugs make the Fe₃O₄@NH₂-β-CD MNPs an exciting prospect for the targeted delivery of GA.

Based on aminated β-cyclodextrin (6-NH₂-β-CD)-grafted Fe₃O₄ and gambogic acid clathrate complexes, a nanoparticle delivery system was developed with the aim of achieving low irritation, strong targeting and high bioavailability of a gambogic acid magnetic nanopreparation.

Carbon-Based Nanomaterials for Biomedical Applications: A Recent Study

The study of carbon-based nanomaterials (CBNs) for biomedical applications has attracted great attention due to their unique chemical and physical properties including thermal, mechanical, electrical, optical and structural diversity. With the help of these intrinsic properties, CBNs, including carbon nanotubes (CNT), graphene oxide (GO), and graphene quantum dots (GQDs), have been extensively investigated in biomedical applications. This review summarizes the most recent studies in developing of CBNs for various biomedical applications including bio-sensing, drug delivery and cancer therapy.

Renal-Clearable Peptide-Functionalized Ba2GdF7 Nanoparticles for Positive Tumor-Targeting Dual-Mode Bioimaging

Considering the dilemma between the effective tumor targeting and the avoidance of potential toxicity, it is desired to design nanoprobes with positive tumor-targeting and good renal clearance ability. In the present work, we developed epidermal growth factor receptor (EGFR)-targeted peptide-functionalized Ba₂GdF₇ nanoparticles (termed as pEGFR-targeted Ba₂GdF₇ NPs) for positive tumor-targeting magnetic resonance imaging and X-ray computed tomography (MRI/CT) dual-mode bioimaging. The positive tumor-targeting ability of pEGFR-targeted Ba₂GdF₇ NPs is achieved by conjugation of EGFR-targeted peptides on the 6.5 nm Ba₂GdF₇ NP surface through the formation of Gd-phosphonate coordinate bonds. The pEGFR-targeted Ba₂GdF₇ NPs display desirable cytocompatibility in the test concentration range and high binding affinity with lung cancer cells. In vivo MR and CT imaging results demonstrate that the pEGFR-targeted Ba₂GdF₇ NPs are able to be accumulated and detained within an engrafted A549 lung carcinoma, which enhances both MR and CT contrast in the tumor tissue. Systematic in vivo experimental results further demonstrate that the pEGFR-targeted Ba₂GdF₇ NPs have favorable in vivo renal clearance kinetics as well as reasonable in vivo biocompatibility.

A magnetic hydrazine-functionalized dendrimer embedded with TiO2 as a novel affinity probe for the selective enrichment of low-abundance phosphopeptides from biological samples

Dendrimers exhibit tunable terminal functionality and bio-friendly nature, making them of being promising materials for applications in the field of separation and enrichment. In this work, we prepared magnetic hydrazide-functionalized poly-amidoamine (PAMAM) dendrimer embedded with TiO₂ for the enrichment of phosphopeptides. The novel affinity probe possessed superparamagnetism, realizing its rapid separation from sample solution. Electrostatic attraction and hydrogen bonding existed between PAMAM and phosphopeptides while Lewis acid-base interaction was originated between TiO₂ and the targets. The combined synergistic strength of multiple binding interactions contributed to the highly selective enrichment of phosphopeptides. The specificity for the capture of phosphopeptides was reflected in quantities as low as 1:1000 mass ratio of phosphopeptides to non-phosphopeptides. The detection limit of β-casein digests was low to 0.4 fmol, indicating the high sensitivity of the developed method. Fifteen and four phosphopeptides could be selectively captured from non-fat milk digests and human serum samples, which further confirmed the great potential of the affinity probe in the extraction of low-abundance phosphopeptides from real complex biological samples.