Inhibition of the cancer-associated TASK 3 channels by magnetically induced thermal release of Tetrandrine from a polymeric drug carrier

Advances in nano-preparations for improving tetrandrine solubility and bioavailability

Tetrandrine (TET) is a natural bis-benzylisoquinoline alkaloid isolated from Stephania species with a wide range of biological and pharmacologic activities; it mainly serves as an anti-inflammatory agent or antitumor adjuvant in clinical applications. However, limitations such as prominent hydrophobicity, severe off-target toxicity, and low absorption result in suboptimal therapeutic outcomes preventing its widespread adoption. Nanoparticles have proven to be efficient devices for targeted drug delivery since drug-carrying nanoparticles can be passively transported to the tumor site by the enhanced permeability and retention (EPR) effects, thus securing a niche in cancer therapies. Great progress has been made in nanocarrier construction for TET delivery due to their outstanding advantages such as increased water-solubility, improved biodistribution and blood circulation, reduced off-target irritation, and combinational therapy. Herein, we systematically reviewed the latest advancements in TET-loaded nanoparticles and their respective features with the expectation of providing perspective and guidelines for future research and potential applications of TET.

Magnetic Thermosensitive Liposomes Loaded with Doxorubicin

Liposome-mediated anticancer drug delivery has the advantage of limiting the massive cytotoxicity of chemotherapeutic agents. Doxorubicin (DOX) PEG-liposomal does however have a slow-release rate that hinders its therapeutic efficacy. In this study, an integrated therapeutic system based on magnetic thermosensitive liposomes was designed. The chelated gadolinium acquired magnetic properties in the liposomes. The hyperthermia induced by ultra-high-field magnetic resonance imaging (UHF-MRI) enhances the chemotherapeutic effects of DOX. The DOX release from liposomes was facilitated over a narrow range of temperatures owing to the phase transition temperature of the liposomes. The magnetic properties of the liposomes were evident by the elevation of contrast after the exposure to UHF-MRI. Moreover, triple-negative breast cancer (TNBC) cells showed a significant decrease in cellular viability reaching less than 40% viability after 1 h of exposure to UHF-MRI. The liposomes demonstrated a physiological coagulation time and a minimal hemolytic potential in hemocompatibility studies; therefore, they were considered safe for physiological application. As a result, magnetic-thermosensitive liposomal guidance of local delivery of DOX could increase the therapeutic index, thereby reducing the amount of the drug required for systemic administration and the chance of affecting the adjacent tissues.

Opportunities and Challenges of Switchable Materials for Pharmaceutical Use

Switchable polymeric materials, which can respond to triggering signals through changes in their properties, have become a major research focus for parenteral controlled delivery systems. They may enable externally induced drug release or delivery that is adaptive to in vivo stimuli. Despite the promise of new functionalities using switchable materials, several of these concepts may need to face challenges associated with clinical use. Accordingly, this review provides an overview of various types of switchable polymers responsive to different types of stimuli and addresses opportunities and challenges that may arise from their application in biomedicine.

Progress on structural modification of Tetrandrine with wide range of pharmacological activities

Tetrandrine (Tet), derived from the traditional Chinese herb Fangji, is a class of natural alkaloids with the structure of bisbenzylisoquinoline, which has a wide range of physiological activities and significant pharmacfological effects. However, studies and clinical applications have revealed a series of drawbacks such as its poor water solubility, low bioavailability, and the fact that it can be toxic to humans. The results of many researchers have confirmed that chemical structural modifications and nanocarrier delivery can address the limited application of Tet and improve its efficacy. In this paper, we summarize the anti-tumor efficacy and mechanism of action, anti-inflammatory efficacy and mechanism of action, and clinical applications of Tet, and describe the progress of Tet based on chemical structure modification and nanocarrier delivery, aiming to explore more diverse structures to improve the pharmacological activity of Tet and provide ideas to meet clinical needs.

Triggered and monitored drug release from bifunctional hybrid nanocomposites

Polymer-coated carbon dot-containing calcium carbonate nanoparticles are reported as unique nanocomposites capable of encapsulating a chemotherapeutic drug and displaying afterglow behaviour.

Remote-controllable bone-targeted delivery of estradiol for the treatment of ovariectomy-induced osteoporosis in rats

BACKGROUND

Osteoporosis (OP) is a systemic skeletal disease marked by bone mass reduction and bone tissue destruction. Hormone replacement therapy is an effective treatment for post-menopausal OP, but estrogen has poor tissue selectivity and severe side effects.

RESULTS

In this study, we constructed a poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs)-based drug delivery system to co-load 17β estradiol (E₂) and iron oxide (Fe₃O₄) together, modified with alendronate (AL) to achieve bone targeting and realize a magnetically remote-controllable drug release. The NPs were fabricated through the emulsion solvent diffusion method. The particle size was approximately 200 nm while the encapsulation efficiency of E₂ was 58.34 ± 9.21%. The NPs were found to be spherical with a homogenous distribution of particle size. The NPs showed good stability, good biocompatibility, high encapsulation ability of E₂ and excellent magnetic properties. The NPs could be effectively taken up by Raw 264.7 cells and were effective in enriching drugs in bone tissue. The co-loaded NPs exposed to an external magnetic field ameliorated OVX-induced bone loss through increased BV/TV, decreased Tb.N and Tb.Sp, improved bone strength, increased PINP and OC, and downregulated CTX and TRAP-5b. The haematological index and histopathological analyses displayed the NPs had less side effects on non-skeletal tissues.

CONCLUSIONS

This study presented a remote-controlled release system based on bone-targeted multifunctional NPs and a new potential approach to bone-targeted therapy of OP.

Polymer Nanocomposite Microactuators for On-Demand Chemical Release via High-Frequency Magnetic Field Excitation

On-demand delivery of substances has been demonstrated for various applications in the fields of chemistry and biomedical engineering. Single-pulse release profile has been shown previously for micro/nanoparticles in different form factors. However, to obtain a sustained release, a pulsatile release profile is needed. Here, we demonstrate such a release profile from polymer magnetic nanocomposite microspheres loaded with chemicals. By exciting the microactuators with AC magnetic fields, we could achieve up to 61% cumulative release over a five-day period. One of the main advantages of using a magnetic stimulus is that the properties of the environment (e.g., transparency, density, and depth) in which the particles are located do not affect the performance. The operating magnitude of the magnetic field used in this work is safe and does not interact with any nonmetallic materials. The proposed approach can potentially be used in microchemistry, drug delivery, lab-on-chip, and microrobots for drug delivery.

A multifunctional magnetic nanosystem based on "two strikes" effect for synergistic anticancer therapy in triple-negative breast cancer

Multifunctional magnetic nanoparticles (MNPs) were widely used for ablation of cancer cells because of their potential on physical treatment. Herein, we developed the "cell targeting destructive" multifunctional polymeric nanoparticles (named as HA-Olb-PPMNPs) based on PEI-PLGA co-loaded with the anticancer drug Olaparib (Olb) and superparamagnetic iron oxide nanoparticles (Fe₃O₄ NPs), and further coated with a low molecular weight hyaluronic acid (HA) on its surface. Due to the high affinity between HA and CD44-receptor on cell surface of triple negative breast cancer (TNBC), an active targeting can be achieved. Under a rotating magnetic field (RMF), HA-Olb-PPMNPs produced a physical transfer of mechanical force by incomplete rotation. This mechanical force could cause the "two strikes" effect on the cells, in which "First-strike" was to damage the cell membrane structure (magneto-cell-lysis), another "Second-strike" could activate the lysosome-mitochondrial pathway by injuring lysosomes to induce cell apoptosis (magneto-cell-apoptosis). Therefore, the mechanical force and Olb exert dual anti-tumor effect to achieve synergistic therapeutic in the presence of RMF. This study proposes a novel multi-therapeutic concept for TNBC, as well as provided evidences of new anti-tumor therapeutic effects induced by the magnetic nanoparticles drug system.

Nanohybrid biodegradable scaffolds for TGF-β3 release for the chondrogenic differentiation of human mesenchymal stem cells

An ideal scaffold for bone tissue engineering should have chondroinductive, biodegradable, and biocompatible properties, as well as the ability to absorb and slowly release the biological molecules. In order to develop such a system to support bone tissue regeneration, in the present study, we developed a three-dimensional poly(L-lactic-co-glycolic acid) (PLGA)/Polycaprolactone (PCL) nanohybrid scaffold embedded with PLGA macroparticles (MPs) conjugated with TGF-β3 for the growth and chondrogenic differentiation of human mesenchymal stem cells (hMSCs). First, a microfluidic device was used to fabricate porous PLGA MPs with the sizes ranging from 10 to 50 µm. Next, the PLGA MPs were loaded with TGF-β3, mixed with PCL solution, and then electrospun to obtain PLGA-TGF-β3 MPs/PCL nanohybrid scaffold. Our results demonstrated that PLGA MPs fabricated using a microfluidic-based approach exhibited enhanced conjugation of TGF-β3 with over 80% loading efficiency and sustained release of TGF-β3. Furthermore, the results of glycosaminoglycan (GAG) content measurement and Safranin O staining revealed that the PLGA-TGF-β3 MPs and PLGA-TGF-β3 MPs/PCL nanohybrid scaffold can promote the proliferation and chondrogenic differentiation of hMSCs in vitro. Therefore, the PLGA-TGF-β3 MPs/PCL nanohybrid scaffold could pave the way for cartilage regeneration and have wide applications in regenerative medicine.

Enhancing cellular morphological changes and ablation of cancer cells via the interaction of drug co-loaded magnetic nanosystems in weak rotating magnetic fields

Tetrandrine and Fe₃O₄ nanoparticle co-loaded PLGA nanosystems produce rotational movement and promote tetrandrine release, causing a dual apoptotic effect to tumors.

Kinetic and spectroscopic responses of pH-sensitive nanoparticles: influence of the silica matrix

Intracellular pH sensing with fluorescent nanoparticles is an emerging topic as pH plays several roles in physiology and pathologic processes. Here, nanoparticle-sized pH sensors (diameter far below 50 nm) for fluorescence imaging have been described. Consequently, a fluorescent derivative of pH-sensitive hydroxypyrene with pK a = 6.1 was synthesized and subsequently embedded in core and core-shell silica nanoparticles via a modified Stöber process. The detailed fluorescence spectroscopic characterization of the produced nanoparticles was carried out for retrieving information about the environment within the nanoparticle core. Several steady-state and time-resolved fluorescence spectroscopic methods hint to the screening of the probe molecule from the solvent, but it sustained interactions with hydrogen bonds similar to that of water. The incorporation of the indicator dye in the water-rich silica matrix neither changes the acidity constant nor dramatically slows down the protonation kinetics. However, cladding by another SiO2 shell leads to the partial substitution of water and decelerating the response of the probe molecule toward pH. The sensor is capable of monitoring pH changes in a physiological range by using ratiometric fluorescence excitation with λ ex = 405 nm and λ ex = 488 nm, as confirmed by the confocal fluorescence imaging of intracellular nanoparticle uptake.

A transfer learning approach via procrustes analysis and mean shift for cancer drug sensitivity prediction

Transfer learning (TL) algorithms aim to improve the prediction performance in a target task (e.g. the prediction of cisplatin sensitivity in triple-negative breast cancer patients) via transferring knowledge from auxiliary data of a related task (e.g. the prediction of docetaxel sensitivity in breast cancer patients), where the distribution and even the feature space of the data pertaining to the tasks can be different. In real-world applications, we sometimes have a limited training set in a target task while we have auxiliary data from a related task. To obtain a better prediction performance in the target task, supervised learning requires a sufficiently large training set in the target task to perform well in predicting future test examples of the target task. In this paper, we propose a TL approach for cancer drug sensitivity prediction, where our approach combines three techniques. First, we shift the representation of a subset of examples from auxiliary data of a related task to a representation closer to a target training set of a target task. Second, we align the shifted representation of the selected examples of the auxiliary data to the target training set to obtain examples with representation aligned to the target training set. Third, we train machine learning algorithms using both the target training set and the aligned examples. We evaluate the performance of our approach against baseline approaches using the Area Under the receiver operating characteristic (ROC) Curve (AUC) on real clinical trial datasets pertaining to multiple myeloma, nonsmall cell lung cancer, triple-negative breast cancer, and breast cancer. Experimental results show that our approach is better than the baseline approaches in terms of performance and statistical significance.

Multifunctional co-loaded magnetic nanocapsules for enhancing targeted MR imaging and in vivo photodynamic therapy

Drug delivery nanocarriers based on magnetic nanoparticles have attracted increasing attention due to their potential applications in magnetic resonance imaging, photodynamic therapy and targeted drug delivery. Herein, we have fabricated the multifunctional co-loaded magnetic nanocapsules (MNCPs) using a microemulsion process for enhancing targeted magnetic resonance imaging and in vivo photodynamic therapy. MNCPs were synthesized by co-loading Co@Mn magnetic nanoparticles and chlorin e6 into the matrix of an amphiphilic polymer, and further surface covalently coupled with target molecules. This work demonstrates that MNCPs have uniform sizes (d_c: ~150 nm), favorable biocompatibility, long-term stability, excellent T₂ relaxation values, and high drug loading efficiency. These advantages offer MNCPs successfully applied in targeted magnetic resonance imaging, real-time fluorescent labeling, and photodynamic therapy. The research results will contribute to rationally design novel nano-platform and provide a promising approach for further clinical integration of diagnosis and treatment in the near future.

Synthesis, purification, and anticancer effect of magnetic Fe3O4-loaded poly (lactic-co-glycolic) nanoparticles of the natural drug tetrandrine

Here, we have successfully synthesised and purified multifunctional PLGA-based nanoparticles by the co-encapsulation of an anticancer drug (tetrandrine) and a magnetic material (Fe₃O₄). The obtained Tet-Fe₃O₄-PLGA NPs had a uniform spherical shape with a particle size of approximately 199 nm and a negative surface charge of -18.0 mV, displaying a high encapsulation efficiency. Furthermore, TEM studies provided representative images of the purification process of the magnetic nanoparticles with MACS^® technology. The MFM and VSM results indicated that both the Fe₃O₄ NPs and Tet-Fe₃O₄-PLGA NPs were superparamagnetic. The DSC spectrum demonstrated that Tet was successfully encapsulated within the PLGA-based nanoparticles. Significantly, the release studies revealed NPs had a relatively slower release rate than free Tet after 8 h's initial burst release, which had decreased from 98% to 65% after 24 h. In vitro cellular studies revealed that NPs could effectively penetrate into A549 cells and A549 multicellular spheroids to exert cytotoxicity, displaying a significantly high anti-proliferation effect. Moreover, western blot demonstrated that the co-loaded NPs had a higher anticancer activity by injuring lysosomes to activate the mitochondria pathway and induce A549 cell apoptosis. The magnetic characteristics and high anticancer activity support the use of Tet/Fe₃O₄ co-loaded PLGA-based nanoparticles as a promising strategy in the treatment of lung cancer.

Development of a fast and precise method for simultaneous quantification of the PLGA monomers lactic and glycolic acid by HPLC

Poly(lactide-co-glycolide acid) (PLGA) is an extraordinary well-described polymer and has excellent pharmaceutical properties like high biocompatibility and good biodegradability. Hence, it is one of the most used materials for drug delivery and biomedical systems, also being present in several US Food and Drug Administration-approved carrier systems and therapeutic devices. For both applications, the quantification of the polymer is inalienable. During the development of a production process, parameters like yield or loading efficacy are essential to be determined. Although PLGA is a well-defined biomaterial, it still lacks a sensitive and convenient quantification approach for PLGA-based systems. Thus, we present a novel method for the fast and precise quantification of PLGA by RP-HPLC. The polymer is hydrolyzed into its monomers, glycolic acid and lactic acid. Afterwards, the monomers are derivatized with the absorption-enhancing molecule 2,4′-dibromoacetophenone. Furthermore, the wavelength of the derivatized monomers is shifted to higher wavelengths, where the used solvents show a lower absorption, increasing the sensitivity and detectability. The developed method has a detection limit of 0.1 µg/mL, enabling the quantification of low amounts of PLGA. By quantifying both monomers separately, information about the PLGA monomer ratio can be also directly obtained, being relevant for degradation behavior. Compared to existing approaches, like gravimetric or nuclear magnetic resonance measurements, which are tedious or expensive, the developed method is fast, ideal for routine screening, and it is selective since no stabilizer or excipient is interfering. Due to the high sensitivity and rapidity of the method, it is suitable for both laboratory and industrial uses.

Tetrandrine suppresses cervical cancer growth by inducing apoptosis in vitro and in vivo

Introduction and aim

Cervical cancers are the most common forms of cancer that occur in women globally and are difficult to be cured in their terminal stages. Tetrandrine (TET), a monomeric compound isolated from a traditional Chinese medicine, Radix Stephania tetrandrae, exhibits anticancer effects on different tumor types. However, the mechanisms by which TET regulates the proliferation, apoptosis, migration, and invasion in cervical cancer remain unclear. Thus, this study aimed to investigate the therapeutic effects of TET on cervical cancer in vitro and in vivo.

Methods

Cell Counting Kit-8, immunofluorescence, flow cytometry, wound healing, and transwell migration assays were used to detect cell proliferation, apoptosis, and migration and invasion, respectively, in vitro. In addition, immunohistochemical assays were performed to evaluate tumor growth and apoptosis in vivo. Moreover, Western blotting was used to examine active caspase 3, matrix metalloproteinase (MMP)2, and MMP9 protein levels in vitro and in vivo.

Results

The results revealed that TET significantly inhibited SiHa cell proliferation in vitro and suppressed tumor growth in vivo. Meanwhile, TET was revealed to induce cervical cancer cell apoptosis by upregulating active caspase 3 in vitro and in vivo. Furthermore, the migration and invasion of SiHa cells were inhibited by TET accompanied with MMP2 and MMP9 downregulation.

Conclusion

We have shown that TET inhibited cervical tumor growth and migration in vitro and in vivo for the first time. The accumulating evidence suggests that TET could be a potential therapeutic agent for the treatment of cervical cancer.

Controllable Microfluidic Production of Drug-Loaded PLGA Nanoparticles Using Partially Water-Miscible Mixed Solvent Microdroplets as a Precursor

We present a versatile continuous microfluidic flow-focusing method for the production of Doxorubicin (DOX) or Tamoxifen (TAM)-loaded poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). We use a partially water-miscible solvent mixture (dimethyl sulfoxide DMSO+ dichloromethane DCM) as precursor drug/polymer solution for NPs nucleation. We extrude this partially water-miscible solution into an aqueous medium and synthesized uniform PLGA NPs with higher drug loading ability and longer sustained-release ability than conventional microfluidic or batch preparation methods. The size of NPs could be precisely tuned by changing the flow rate ratios, polymer concentration, and volume ratio of DCM to DMSO (VDCM/VDMSO) in the precursor emulsion. We investigated the mechanism of the formation of NPs and the effect of VDCM/VDMSO on drug release kinetics. Our work suggests that this original, rapid, facile, efficient and low-cost method is a promising technology for high throughput NP fabrication. For the two tested drugs, one hydrophilic (Doxorubicin) the other one hydrophobic (Tamoxifen), encapsulation efficiency (EE) as high as 88% and mass loading content (LC) higher than 25% were achieved. This new process could be extended as an efficient and large scale NP production method to benefit to fields like controlled drug release and nanomedicine.

One-Step Facile Synthesis of Highly Magnetic and Surface Functionalized Iron Oxide Nanorods for Biomarker-Targeted Applications

We report a one-step method for facile and sustainable synthesis of magnetic iron oxide nanorods (or IONRs) with mean lengths ranging from 25 to 50 nm and mean diameters ranging from 5 to 8 nm. The prepared IONRs are highly stable in aqueous media and can be surface functionalized for biomarker-targeted applications. This synthetic strategy involves the reaction of iron(III) acetylacetonate with polyethyleneimine in the presence of oleylamine and phenyl ether, followed by thermal decomposition. Importantly, the length and diameter as well as the aspect ratio of the prepared IONRs can be controlled by modulating the reaction parameters. We show that the resultant IONRs exhibit stronger magnetic properties compared to those of the widely used spherical iron oxide nanoparticles (IONPs) at the same iron content. The increased magnetic properties are dependent on the aspect ratio, with the magnetic saturation gradually increasing from 10 to 75 emu g^-1 when increasing length of the IONRs, 5 nm in diameter, from 25 to 50 nm. The magnetic resonance imaging (MRI) contrast-enhancing effect, as measured in terms of the transverse relaxivity, r₂, increased from 670.6 to 905.5 mM^-1 s^-1, when increasing the length from 25 to 50 nm. When applied to the immunomagnetic cell separation of the transferrin receptor (TfR)-overexpressed medulloblastoma cells using transferrin (Tf) as the targeting ligand, Tf-conjugated IONRs can capture 92 ± 3% of the targeted cells under a given condition (2.0 × 10⁴ cells/mL, 0.2 mg Fe/mL concentration of magnetic materials, and 2.5 min of incubation time) compared to only 37 ± 2% when using the spherical IONPs, and 14 ± 2% when using commercially available magnetic beads, significantly improving the efficiency of separating the targeted cells.

Multifunctional Core@Shell Magnetic Nanoprobes for Enhancing Targeted Magnetic Resonance Imaging and Fluorescent Labeling in Vitro and in Vivo

Core@shell magnetic nanoparticles (core@shell MNPs) are attracting widespread attention due to their enhancement properties for potential applications in hyperthermia treatment, magnetic resonance imaging (MRI), diagnostics, and so forth. Herein, we developed a facile thermal decomposition method for controllable synthesis of a superparamagnetic, monodispersed core@shell structure (Co@Mn = CoFe₂O₄@MnFe₂O₄) with uniform size distribution (σ < 5%, d_c ≈ 15 nm). The CoFe₂O₄ core could enhance magnetic anisotropy, and the MnFe₂O₄ shell could improve the magnetization value. The Co@Mn MNPs were transferred into aqueous solution with an amphiphilic polymer (labeled 2% TAMRA) and functionalized with PEG_2k and target molecules (folic acid, FA) to fabricate multifunctional PMA_TAMRA-Co@Mn-PEG_2k-FA nanoprobes. The obtained PMA_TAMRA-Co@Mn-PEG_2k-FA nanoprobes exhibit good biocompatibility, high T₂ relaxation values, and long-term fluorescence stability (at least 6 months). Our results demonstrate that the synthesized PMA_TAMRA-Co@Mn-PEG_2k-FA nanoprobes can effectively enhance the targeted MRI and fluorescent labeling in vitro and in vivo. The research outcomes will contribute to the rational design of new nanoprobes and provide a promising pathway to promote core@shell nanoprobes for further clinical contrast MRI and photodynamic therapy in the near future.

Drug releasing nanoplatforms activated by alternating magnetic fields

The use of an alternating magnetic field (AMF) to generate non-invasively and spatially a localized heating from a magnetic nano-mediator has become very popular these last years to develop magnetic hyperthermia (MH) as a promising therapeutic modality already used in the clinics. AMF has become highly attractive this last decade over others radiations, as AMF allows a deeper penetration in the body and a less harmful ionizing effect. In addition to pure MH which induces tumor cell death through local T elevation, this AMF-generated magneto-thermal effect can also be exploited as a relevant external stimulus to trigger a drug release from drug-loaded magnetic nanocarriers, temporally and spatially. This review article is focused especially on this concept of AMF induced drug release, possibly combined with MH. The design of such magnetically responsive drug delivery nanoplatforms requires two key and complementary components: a magnetic mediator which collects and turns the magnetic energy into local heat, and a thermoresponsive carrier ensuring thermo-induced drug release, as a consequence of magnetic stimulus. A wide panel of magnetic nanomaterials/chemistries and processes are currently developed to achieve such nanoplatforms. This review article presents a broad overview about the fundamental concepts of drug releasing nanoplatforms activated by AMF, their formulations, and their efficiency in vitro and in vivo. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editors: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.