Fe3O4SPIONs in cancer theranostics-structure versus interactions with proteins and methods of their investigation

As the second leading cause of death worldwide, neoplastic diseases are one of the biggest challenges for public health care. Contemporary medicine seeks potential tools for fighting cancer within nanomedicine, as various nanomaterials can be used for both diagnostics and therapies. Among those of particular interest are superparamagnetic iron oxide nanoparticles (SPIONs), due to their unique magnetic properties,. However, while the number of new SPIONs, suitably modified and functionalized, designed for medical purposes, has been gradually increasing, it has not yet been translated into the number of approved clinical solutions. The presented review covers various issues related to SPIONs of potential theranostic applications. It refers to structural considerations (the nanoparticle core, most often used modifications and functionalizations) and the ways of characterizing newly designed nanoparticles. The discussion about the phenomenon of protein corona formation leads to the conclusion that the scarcity of proper tools to investigate the interactions between SPIONs and human serum proteins is the reason for difficulties in introducing them into clinical applications. The review emphasizes the importance of understanding the mechanism behind the protein corona formation, as it has a crucial impact on the effectiveness of designed SPIONs in the physiological environment.

Magnetic Nanoparticles Mediated Thrombolysis-A Review

Nanoparticles containing thrombolytic medicines have been developed for thrombolysis applications in response to the increasing demand for effective, targeted treatment of thrombosis disease. In recent years, there has been a great deal of interest in nanoparticles that can be navigated and driven by a magnetic field. However, there are few review publications concerning the application of magnetic nanoparticles in thrombolysis. In this study, we examine the current state of magnetic nanoparticles in the application of in vitro and in vivo thrombolysis under a static or dynamic magnetic field, as well as the combination of magnetic nanoparticles with an acoustic field for dual-mode thrombolysis. We also discuss four primary processes of magnetic nanoparticles mediated thrombolysis, including magnetic nanoparticle targeting, magnetic nanoparticle trapping, magnetic drug release, and magnetic rupture of blood clot fibrin networks. This review will offer unique insights for the future study and clinical development of magnetic nanoparticles mediated thrombolysis approaches.

In vitro galactose-targeted study of RSPP050-loaded micelles against liver hepatocellular carcinoma

Andrographolide is in a group of diterpenoid lactone isolated from Andrographis paniculata (Burm.f.) NEES. One of the analogs is 19-O-triphenylmethylandrographolide (RSPP050) which possesses anticancer activity. In seeking to capitalise on the last property, we have investigated the in vitro tumour targeting capabilities and MRI imaging for hepatocellular carcinoma. In this study, we have designed galactose-targeted and non-targeted micelles comprised of poly(ethylene glycol)-b-poly(lactide) that enveloped RSPP050 as an anticancer agent and superparamagnetic iron oxide (SPIO) as a contrast agent. The targeting abilities were endeavored by examining the cellular uptake with MTT assay, fluorescence microscopy, Prussian blue staining, and in vitro MRI. Targeted SPIO micelles as a T₂* contrast agent decreased the relative T2* MRI intensity at 3 h. Results revealed that galactose micelles displayed 10.91 ± 0.19% drug loading content, -37.17 ± 0.63 mV zeta potential, and these micelles at the concentration of 0.5 µg/ml exhibited higher cytotoxicity than non-targeted micelles and free RSPP050 after incubation for 24 h. Fluorescence microscopy and Prussian blue staining at 3 h demonstrated significant cellular uptake by HepG2 cells. Thus, anticancer activity of RSPP050 could be improved using galactose as a targeting ligand and theranostic function was achieved using SPIO.

Iron Oxide Nanoparticle-Based Hyperthermia as a Treatment Option in Various Gastrointestinal Malignancies

Iron oxide nanoparticle-based hyperthermia is an emerging field in cancer treatment. The hyperthermia is primarily achieved by two differing methods: magnetic fluid hyperthermia and photothermal therapy. In magnetic fluid hyperthermia, the iron oxide nanoparticles are heated by an alternating magnetic field through Brownian and Néel relaxation. In photothermal therapy, the hyperthermia is mainly generated by absorption of light, thereby converting electromagnetic waves into thermal energy. By use of iron oxide nanoparticles, this effect can be enhanced. Both methods are promising tools in cancer treatment and are, therefore, also explored for gastrointestinal malignancies. Here, we provide an extensive literature research on both therapy options for the most common gastrointestinal malignancies (esophageal, gastric and colorectal cancer, colorectal liver metastases, hepatocellular carcinoma, cholangiocellular carcinoma and pancreatic cancer). As many of these rank in the top ten of cancer-related deaths, novel treatment strategies are urgently needed. This review describes the efforts undertaken in vitro and in vivo.

Localized NIR-II photo-immunotherapy through the combination of photothermal ablation and in situ generated interleukin-12 cytokine for efficiently eliminating primary and abscopal tumors

Recently, photothermal therapy (PTT) in the second near-infrared (NIR-II) biowindow has emerged as a promising treatment modality; however, its therapeutic outcomes are still limited by heterogeneous heat distribution and insufficient control of metastatic lesions. Tremendous efforts have been made to overcome the PTT's shortcomings by combining PTT with immunotherapy, but unfortunately current strategies still suffer from low response rates, primary/acquired resistance or severe immune-related adverse events. Herein, a novel photothermal agent and gene co-delivery nanoparticle (CSP), with CuS inside the SiO2 pore channels and PDMAEMA polycation on the outside of SiO2 surface, is explored for tumor localized NIR-II PTT and in situ immunotherapy through local generation of IL-12 cytokine. The resulting CSP integrated with the plasmid encoding IL-12 gene (CSP@IL-12) exhibited good gene transfection efficiency, outstanding NIR-II PTT effect and excellent therapeutic outcomes both in vitro and in vivo. Meanwhile, such an in situ joint therapy modality could significantly induce systemic immune responses including promoting DC maturation, CD8+ T cell proliferation and infiltration to efficiently eliminate possible metastatic lesions through abscopal effects. Hence, this creative combinational strategy of NIR-II PTT and IL-12 cytokine therapy might provide a more efficient, controllable and safer alternative strategy for future photo-immunotherapy.

Assembly and in vitro assessment of a powerful combination: aptamer-modified exosomes combined with gold nanorods for effective photothermal therapy

Due to good biocompatibility and plasma membrane similarity, the nanosized exosomes are ideal drug carriers. Near-infrared (NIR) photothermal therapy is an emerging method for cancer treatment in which photothermal agents absorb the energy of external NIR light to generate high temperatures in a targeted region to effectively kill cancer cells. Gold nanorods (AuNRs) have been found to provide a prominent photothermal performance, while aptamers can precisely target surface markers on cells with high affinity and specificity. In this study, exosomes were mildly functionalized by integrating them with aptamers and AuNRs to assemble a powerful combination Apt-Exos-AuNRs (AEARs) with good specificity and an effective photothermal killing action on cancer cells. The structure, hydrodynamic diameters, zeta potential, UV-vis absorption spectra and stability of the AEARs were further characterized. In addition, using a cell model, the cancer cell targeting ability of the AEARs and its cellular uptake were observed. Moreover, its photothermal killing effect on various human cancer cells in vitro was validated by a CCK-8 assay as well as apoptosis analysis, the results of which suggest this exosomes-based nanomaterial can serve as a novel and broad-spectrum platform for precision cancer therapy.

Shell-Free Copper Indium Sulfide Quantum Dots Induce Toxicity in Vitro and in Vivo

Semiconductor quantum dots (QDs) are attractive fluorescent contrast agents for in vivo imaging due to their superior photophysical properties, but traditional QDs comprise toxic materials such as cadmium or lead. Copper indium sulfide (CuInS₂, CIS) QDs have been posited as a nontoxic and potentially clinically translatable alternative; however, previous in vivo studies utilized particles with a passivating zinc sulfide (ZnS) shell, limiting direct evidence of the biocompatibility of the underlying CIS. For the first time, we assess the biodistribution and toxicity of unshelled CIS and partially zinc-alloyed CISZ QDs in a murine model. We show that bare CIS QDs breakdown quickly, inducing significant toxicity as seen in organ weight, blood chemistry, and histology. CISZ demonstrates significant, but lower, toxicity compared to bare CIS, while our measurements of core/shell CIS/ZnS are consistent with literature reports of general biocompatibility. In vitro cytotoxicity is dose-dependent on the amount of metal released due to particle degradation, linking degradation to toxicity. These results challenge the assumption that removing heavy metals necessarily reduces toxicity: indeed, we find comparable in vitro cytotoxicity between CIS and CdSe QDs, while CIS caused severe toxicity in vivo compared to CdSe. In addition to highlighting the complexity of nanotoxicity and the differences between the in vitro and in vivo outcomes, these unexpected results serve as a reminder of the importance of assessing the biocompatibility of core QDs absent the protective ZnS shell when making specific claims of compositional biocompatibility.

Carbon Nanodots Doped Super-paramagnetic Iron Oxide Nanoparticles for Multimodal Bioimaging and Osteochondral Tissue Regeneration via External Magnetic Actuation

Super-paramagnetic iron oxide nanoparticles (SPIONs) have multiple theranostics applications such as T2 contrast agent in magnetic resonance imaging (MRI) and electromagnetic manipulations in biomedical devices, sensors, and regenerative medicines. However, SPIONs suffer from the limitation of free radical generation, and this has a certain limitation in its applicability in tissue imaging and regeneration applications. In the current study, we developed a simple hydrothermal method to prepare carbon quantum dots (CD) doped SPIONs (FeCD) from easily available precursors. The nanoparticles are observed to be cytocompatible, hemocompatible, and capable of scavenging free radicals in vitro. They also have been observed to be useful for bimodal imaging (fluorescence and MRI). Further, 3D printed gelatin-FeCD nanocomposite nanoparticles were prepared and used for tissue engineering using static magnetic actuation. Wharton's jelly derived mesenchymal stem cells (MSCs) were cultured on them with magnetic actuation and implanted at the subcutaneous region. The tissues obtained have shown features of both osteogenic and chondrogenic differentiation of the stem cells in vivo. In vitro, PCR studies show MSCs express gene expression of both bone and cartilage-specific markers, suggesting FeCDs under magnetic actuation can lead MSCs to go through differentiating into an endochondral ossification route.

Biocompatible Chitosan Oligosaccharide Modified Gold Nanorods as Highly Effective Photothermal Agents for Ablation of Breast Cancer Cells

Photothermal therapy (PTT) using biocompatible nanomaterials have recently attracted much attention as a novel candidate technique for cancer therapy. In this work we report the performance of newly synthesized multidentate chitosan oligosaccharide modified gold nanorods (AuNRs-LA-COS) as novel agents for PTT of cancer cells due to their excellent biocompatibility, photothermal stability, and high absorption in the near-infrared (NIR) region. The AuNRs-LA-COS exhibit a strong NIR absorption peak at 838 nm with a mean length of 26 ± 3.1 nm and diameter of 6.8 ± 1.7 nm, respectively. The temperature of AuNRs-LA-COS rapidly reached 52.6 °C for 5 min of NIR laser irradiation at 2 W/cm². The AuNRs-LA-COS had very low cytotoxicity and exhibited high efficiency for the ablation of breast cancer cells in vitro. The tumor-bearing mice were completely ablated without tumor recurrence after photothermal treatment with AuNRs-LA-COS (25 µg/mL) under laser irradiation. In summary, this study demonstrated that AuNRs-LA-COS with laser irradiation as novel agents pave an alternative way for breast cancer therapy and hold great promise for clinical trials in the near future.

Dually folate/CD44 receptor-targeted self-assembled hyaluronic acid nanoparticles for dual-drug delivery and combination cancer therapy

Nanoparticles (NPs) functionalized with targeting ligands have shown promise, but are still limited by their nonspecific uptake by certain healthy tissues and cells that express low or even comparable levels of receptors. To increase their accumulation at tumor sites while decreasing the unintended toxicity, a possible solution is the involvement of two separate tumor-specific ligands in the localization. In this study, a dual tumor-targeting drug-loaded NP system was self-assembled by the amphiphilic conjugate of methotrexate-hyaluronic acid-octadecylamine (MTX-HA-OCA) with curcumin (CUR) encapsulated within the hydrophobic core (designated as MTX-HA-OCA/CUR NPs). The advantages of this nanosystem are that the anticancer drug MTX can be utilized as a tumor-targeting ligand toward folate receptors due to its structural similarity to folic acid (FA), and HA can serve as another tumor-targeting ligand toward CD44 receptors. The MTX-HA-OCA/CUR NPs are ∼70 nm in diameter and have sustained/controlled drug release behavior. An in vitro cellular uptake and competition inhibition study exhibited that MTX-HA-OCA/CUR NPs could significantly enhance the internalization efficiency in HeLa cells via folate/CD44 receptor-mediated endocytosis as compared to HA-OCA/CUR NPs. More importantly, the in vitro cytotoxicity of MTX-HA-OCA/CUR NPs was significantly enhanced as compared to those of the HA-OCA/CUR NPs, both free drugs, and individual free drug. Furthermore, the real-time in vivo and ex vivo fluorescence imaging of HeLa tumor-bearing mice showed that MTX-HA-OCA/CUR NPs could more efficiently enhance their accumulation and improve the penetration at the tumor site as compared to HA-OCA/CUR NPs. Therefore, these dually folate/CD44 receptor-targeted self-assembled HA NPs for the co-delivery of both anticancer drugs might provide a promising strategy for dual-targeted combination cancer therapy.

Core-shell NaGdF4@CaCO3 nanoparticles for enhanced magnetic resonance/ultrasonic dual-modal imaging via tumor acidic micro-enviroment triggering

For cancer diagnosis, a paramount challenge still exists in the exploring of methods that can precisely discriminate tumor tissues from their surrounding healthy tissues with a high target-to-background signal ratio. Here, we report a NaGdF4@CaCO3-PEG core-shell nanoparticle which has the tumor acidic microenvironment enhanced imaging signals of ultrasound and magnetic resonance. Under the acidic conditions, the CaCO3 shell will gradually dissolve which then facilitate the interaction of NaGdF4 with the external aqueous environment to enhance water proton relaxation. Meanwhile, the CO2 bubbles generated by the CaCO3 dissolvement will generate strong elastic echo for US detection. The core-shell structure of NaGdF4@CaCO3-PEG can be observed by TEM, and its composition can be determined by STEM. The acid triggered generation of CO2 bubbles and the enhancement of MRI signal could be demonstrated in vitro, and the excellent dual-modal magnetic resonance/ultrasonic cancer imaging abilities of NaGdF4@CaCO3-PEG could be also proved at the tumor site in vivo. The here described proof-of-concept nanoparticles with pH triggered magnetic resonance/ultrasonic dual-modal imaging enhancement, may serve as a useful guide to develop various molecular imaging strategies for cancer diagnosis in the future.

One-Pot Synthesis of MoS2 Nanoflakes with Desirable Degradability for Photothermal Cancer Therapy

Developing biodegradable photothermal agent holds great significance for potential clinical translation of photothermal therapy. In the current study, one-pot hydrothermal synthesis of MoS₂ nanoflakes with desirable degradation capability was presented. The participation of poly(acrylic acid) (PAA) in hydrothermal process could not only facilitate the modification of polyethylene glycol (PEG), but also bestow degradability to the prepared MoS₂ nanoflakes. Moreover, the PEGylated hybrid nanoflakes (MoS₂-PPEG) also exhibited excellent stability in various medium and outstanding photothermal properties. Interestingly, MoS₂-PPEG behaved distinctly different degradation rate in diverse condition. The rapid degradation of MoS₂-PPEG was observed in neutral pH solution, whereas much slower degradation occurred in an acidic tumor microenvironment. Furthermore, data indicated that the major degradation product of MoS₂-PPEG was water-soluble Mo-based ion. Meanwhile, the good in vitro biocompatibility of MoS₂-PPEG was also confirmed in terms of cytotoxicity and hemolysis. With favorable photothermal performance, MoS₂-PPEG can efficiently killing cancer cells in vitro and suppress the tumor growth in vivo. More importantly, the gradual decreasing content of MoS₂-PPEG in organs and detectable Mo element in urine of mice suggested that the degradability of MoS₂-PPEG might facilitate its excretion to some degree. Hence, the degradable MoS₂ nanoflakes prepared by one-pot hydrothermal routine may provide insight for further biomedical applications of inorganic photothermal agent.

Recent progress and development on polymeric nanomaterials for photothermal therapy: a brief overview

This review article summarizes the recent development and progress of polymeric photothermal agents for photothermal therapy and imaging-guided photothermal therapy applications.

Amphiphilic copolymer and TPGS mixed magnetic hybrid micelles for stepwise targeted co-delivery of DOX/TPP–DOX and image-guided chemotherapy with enhanced antitumor activity in liver cancer

Stepwise targeted and image-guided chemotherapy with enhanced antitumor activity in liver cancer.