Distinct CPT-induced deaths in lung cancer cells caused by clathrin-mediated internalization of CP micelles

Interplay of distributions of multiple guest molecules in block copolymer micelles: A dissipative particle dynamics study

HYPOTHESIS

Delivery of multiple payloads using the same micelle is of significance to achieve multifunctional or synergistic effects. The interacting distribution of different payloads in micelles is expected to influence the loading stability and capacity. It is highly desirable to explore how intermolecular interactions affect the joint distribution of multi-payloads.

EXPERIMENTS

Dissipative Particle Dynamics simulations were performed to probe the loading of three payloads: decane with a linear carbon chain, butylbenzene with an aromatic ring connected to carbon chain, and naphthalene with double aromatic rings, within poly(β-amino ester)-b-poly(ethylene glycol) micelles. Properties of core-shell micelles, e.g., morphological evolution, radial density distribution, mean square displacement, and contact statistics, were analyzed to reveal payloads loading stability and capacity. Explorations were extended to vesicular, multi-compartment, double helix, and layer-by-layer micelles with more complex inner structures.

FINDINGS

Different payloads have their own preferred locations. Decane locates at the hydrophilic/hydrophobic interface, butylbenzene occupies both the hydrophilic/hydrophobic interface and the hydrophobic core, while naphthalene enters the hydrophobic core. More efficient delivery of multi-payloads is achieved since the competition of payloads occupying preferred locations is minimized. The fusion of micelles encapsulating different payloads suggests that specific payloads will move to their preferred positions without interfering other payloads.

IR780-based nanomaterials for cancer imaging and therapy

IR780, a small molecule with a strong optical property and excellent photoconversion efficiency following near infrared (NIR) irradiation, has attracted increasing attention in the field of cancer treatment and imaging. This review is focused on different IR780-based nanoplatforms and the application of IR780-based nanomaterials for cancer bioimaging and therapy. Thus, this review summarizes the overall aspects of IR780-based nanomaterials that positively impact cancer biomedical applications.

Exploration and insights into the cellular internalization and intracellular fate of amphiphilic polymeric nanocarriers

The beneficial or deleterious effects of nanomedicines emerge from their complex interactions with intracellular pathways and their subcellular fate. Moreover, the dynamic nature of plasma membrane accounts for the movement of these nanocarriers within the cell towards different organelles thereby not only influencing their pharmacokinetic and pharmacodynamic properties but also bioavailability, therapeutic efficacy and toxicity. Therefore, an in-depth understanding of underlying parameters controlling nanocarrier endocytosis and intracellular fate is essential. In order to direct nanoparticles towards specific sub-cellular organelles the physicochemical attributes of nanocarriers can be manipulated. These include particle size, shape and surface charge/chemistry. Restricting the particle size of nanocarriers below 200 nm contributes to internalization via clathrin and caveolae mediated pathways. Similarly, a moderate negative surface potential confers endolysosomal escape and targeting towards mitochondria, endoplasmic reticulum (ER) and Golgi. This review aims to provide an insight into these physicochemical attributes of nanocarriers fabricated using amphiphilic graft copolymers affecting cellular internalization. Fundamental principles understood from experimental studies have been extrapolated to draw a general conclusion for the designing of optimized nanoparticulate drug delivery systems and enhanced intracellular uptake via specific endocytic pathway.

Multi-Stimuli-Responsive DOX Released from Magnetosome for Tumor Synergistic Theranostics

Background

To improve responses to tumor microenvironments for achieving a better therapeutic outcome in combination cancer therapy, poly(ε-caprolactone)-SS-poly(methacrylic acid) diblock copolymer (PCL-SS-PMAA) with a disulfide linkage between the hydrophobic and hydrophilic junctions was synthesized.

Materials and Methods

Repeating units of PCL and PMAA in PCL-SS-PMAA were controlled and formulated into polymersomes (PSPps). Truncated octahedral Fe₃O₄ nanoparticles (IONPs) were synthesized and encapsulated to produce IONPs-PSPps NPs and doxorubicin (DOX) was further loaded to produce IONPs-PSPps@DOX NPs for theranostic applications.

Results

IONPs-PSPps NPs remained a superparamagnetic property with a saturation magnetization value of 85 emu⋅g_Fe3O4 ^-1 and a relaxivity value of 180 mM^-1⋅s^-1. Upon exposure to an alternating magnetic field (AMF), IONPs-PSPps NPs increased temperature from 25°C to 54°C within 15 min. Among test groups, the cell apoptosis was greatest in the group exposed to IONPs-PSPps@DOX NPs with AMF and magnet assistance. In vivo T₂-weighted magnetic resonance images of A549 tumor-bearing mice also showed highest contrast and greatest tumor suppression in the tumor with AMF and magnet assistance.

Conclusion

IONPs-PSPps@DOX NPs are a potential theranostic agent having multifaceted applications involving magnetic targeting, MRI diagnosis, hyperthermia and chemotherapy.

Phytochemical naphtho[1,2-b] furan-4,5‑dione induced topoisomerase II-mediated DNA damage response in human non-small-cell lung cancer

BACKGROUND

Phytochemical naphtho[1,2-b] furan-4,5‑dione (NFD) presenting in Avicennia marina exert anti-cancer effects, but little is known regarding about DNA damage-mediated apoptosis in non-small-cell lung carcinoma (NSCLC).

PURPOSE

To examine whether NFD-induced apoptosis of NSCLC cells is correlated with the induction of DNA damage, and to investigate its underlying mechanism.

STUDY DESIGN

The anti-proliferative effects of NFD were assessed by MTS Assay Kit FACS assay, and in vivo nude mice xenograft assay. The DNA damage related proteins, the Bcl-2 family and pro-apoptotic factors were examined by immunofluorescence assay, q-PCR, and western blotting. The activity of NF-κB p65 in nuclear extracts was detected using a colorimetric DNA-binding ELISA assay. The inhibitory activity of topoisomerase II (TOPO II) was evaluated by molecular docking and TOPO II catalytic assay.

RESULTS

NFD exerted selective cytotoxicity against NSCLC H1299, H1437 and A549 cells rather than normal lung-embryonated cells MRC-5. Remarkably, we found that NFD activated the hull marker and modulator of DNA damage repairs such as γ-H2AX, ATM, ATR, CHK1, and CHK2 probably caused by the accumulation of intracellular reactive oxygen species (ROS) and inhibition of TOPO II activity. Furthermore, the suppression of transcription factor NF-κB by NFD resulted in significantly decreased levels of pro-survival proteins including Bcl-2 family Bcl-2, Bcl-xL and Mcl-1 and the endogenous inhibitors of apoptosis XIAP and survivin in H1299 cells. Moreover, the nude mice xenograft assay further validated the suppression of H1299 growth by NFD, which is the first report for evaluating the anti-cancer effect of NFD in vivo.

CONCLUSION

These findings provide a novel mechanism indicating the inhibition of TOPO II activity and NF-κB signaling by NFD, leading to DNA damage and apoptosis of NSCLC tumor cells.

Dimeric Prodrug Self-Delivery Nanoparticles with Enhanced Drug Loading and Bioreduction Responsiveness for Targeted Cancer Therapy

Efficient drug accumulation in tumor cells is essential for cancer therapy. Herein, we developed dimeric prodrug self-delivery nanoparticles (NPs) with enhanced drug loading and bioreduction responsiveness for triple negative breast cancer (TNBC) therapy. Specially designed camptothecin dimeric prodrug (CPTD) containing a disulfide bond was constructed to realize intracellular redox potential controlled drug release. Direct conjugation of hydrophobic CPTD to poly(ethylene glycol) PEG₅₀₀₀, a prodrug-based amphiphilic CPTD-PEG₅₀₀₀ co-polymer was synthesized, which could encapsulate parental CPTD prodrug spontaneously and form ultrastable NPs due to the highly analogous structure. Such dimeric prodrug self-delivery nanoparticles showed ultrahigh stability with critical micelle concentration as low as 0.75 μg/mL and remained intact during endocytosis. In addition, neurotensin (NT), a 13 amino acid ligand, was further modified on the nanoparticles for triple negative breast cancer (TNBC) targeting. Optimized NT-CPTD NPs showed improved pharmacokinetics profile and increased drug accumulation in TNBC lesions than free CPT, which largely reduced the systemic toxicity and presented an improved anticancer efficacy in vivo. In summary, with advantages of extremely high drug loading capacity, tumor microenvironmental redox responsiveness, and targeted TNBC accumulation, NT-CPTD NPs showed their potential for effective triple negative breast cancer therapy.

Photo-triggered micelles: simultaneous activation and release of microtubule inhibitors for on-demand chemotherapy

We report β-cyclodextrin-bearing micelles that can efficiently load Azo-CA4 and realize simultaneous drug activation and release upon light triggering.

Enzyme and Redox Dual-Triggered Intracellular Release from Actively Targeted Polymeric Micelles

Highly effective delivery of therapeutic agents into target cells using nanocarriers and subsequently rapid intracellular release are of great importance in cancer treatment. Here, we developed an enzyme and redox dual-responsive polymeric micelle with active targeting abilities to achieve rapid intracellular drug release. To overcome both its poor solubility in water and instability in the blood circulation, camptothecin (CPT) was chemically conjugated to monomethyl poly(ethylene glycol) (mPEG) via a redox-responsive linker to form polymeric prodrugs. The enzyme-responsive function is achieved by connecting hydrophobic polycaprolactone segments and hydrophilic PEG segments with azo bonds. Additionally, the end of the PEG segment was decorated with phenylboronic acid (PBA), endowing the nanocarriers with active targeting abilities. The dual-responsive targeting polymeric micelles can be generated by self-assembly of a mixture of the polymeric prodrug and enzyme-responsive copolymer. The in vitro drug release profile revealed that CPT was rapidly released from the micelles under a simulated condition similar to the tumor cell microenvironment. In vivo and ex vivo fluorescence imaging indicated that these micelles possess excellent specificity to target hepatoma carcinoma cells. The antitumor effect in mice liver cancer cells (H22) in tumor-bearing Kunming (KM) mice demonstrated that this nanocarrier exhibits high therapeutic efficiency in artificial solid tumors and low toxicity to normal tissues, with a survival rate of approximately 100% after 160 days of treatment.

Safe approaches for camptothecin delivery: Structural analogues and nanomedicines

Twenty-(S)-camptothecin is a strongly cytotoxic molecule with excellent antitumor activity over a wide spectrum of human cancers. However, the direct formulation is limited by its poor water solubility, low plasmatic stability and severe toxicity, which currently limits its clinical use. As a consequence, two strategies have been developed in order to achieve safe and efficient delivery of camptothecin to target cells: structural analogues and nanomedicines. In this review, we summarize recent advances in the design, synthesis and development of camptothecin molecular derivatives and supramolecular vehicles, following a systematic classification according to structure-activity relationships (structural analogues) or chemical nature (nanomedicines). A series of organic, inorganic and hybrid materials are presented as nanoplatforms to overcome camptothecin restrictions in administration, biodistribution, pharmacokinetics and toxicity. Nanocarriers which respond to a variety of stimuli endogenously (e.g., pH, redox potential, enzyme activity) or exogenously (e.g., magnetic field, light, temperature, ultrasound) seem the best positioned therapeutic materials for optimal spatial and temporal control over drug release. The main goal of this review is to be used as a source of relevant literature for others interested in the field of camptothecin-based therapeutics. To this end, final remarks on the most important formulations currently under clinical trial are provided.

An Acetamide Derivative as a Camptothecin Sensitizer for Human Non-Small-Cell Lung Cancer Cells through Increased Oxidative Stress and JNK Activation

In recent years, combination chemotherapy is a primary strategy for treating lung cancer; however, the issues of antagonism and side effects still limit its applications. The development of chemosensitizer aims to sensitize chemoresistant cancer cells to anticancer drugs and therefore improve the efficacy of chemotherapy. In this study, we examined whether N-[2-(morpholin-4-yl)phenyl]-2-{8-oxatricyclo[7.4.0.0,2,7]trideca-1(9),2(7),3,5,10,12-hexaen-4-yloxy}acetamide (NPOA), an acetamide derivative, sensitizes human non-small-cell lung cancer (NSCLC) H1299 cells towards camptothecin- (CPT-) induced apoptosis effects. Our results demonstrate that the combination of CPT and NPOA enhances anti-lung-cancer effect. The cytometer-based Annexin V/propidium iodide (PI) staining showed that CPT and NPOA cotreatment causes an increased population of apoptotic cells compared to CPT treatment alone. Moreover, Western blotting assay showed an enhancement of Bax expression and caspase cascade leading to cell death of H1299 cells. Besides, CPT and NPOA cotreatment-mediated disruption of mitochondrial membrane potential (MMP) in H1299 cells may function through increasing the activation of the stressed-associated c-Jun N-terminal kinase (JNK). These results showed that NPOA treatment sensitizes H1299 cells towards CPT-induced accumulation of cell cycle S phase and mitochondrial-mediated apoptosis through regulating endogenous ROS and JNK activation. Accordingly, NPOA could be a candidate chemosensitizer of CPT derivative agents such as irinotecan or topotecan in the future.

Enhanced Targeted Delivery of Cyclodextrin-Based Supermolecules by Core-Shell Nanocapsules for Magnetothermal Chemotherapy

In this study, double-emulsion capsules (DECs) capable of concealing drug-incorporated targeted-supermolecules are developed to achieve "on-demand" supermolecule release and enhanced sequential targeting for magneto-chemotherapy. These water-in-oil-in-water DECs less than 200 nm in diameter are synthesized using a single component of PVA (polyvinyl alcohol) polymer and the magnetic nanoparticles, which are capable of encapsulating large quantities of targeted supermolecules composed of palitaxel-incorporated beta-cyclodextrin decorated by hyaluronic acid (HA, a CD44-targeting ligand) in the watery core. The release profiles (slow, sustained and burst release) of the targeted supermolecules can be directly controlled by regulating the high-frequency magnetic field (HFMF) and polymer conformation without sacrificing the targeting ability. Through an intravenous injection, the positive targeting of the supermolecules exhibited a 20-fold increase in tumor accumulation via the passive targeting and delivery of DECs followed by positive targeting of the supermolecules. Moreover, this dual-targeting drug-incorporated supermolecular delivery vehicle at the tumor site combined with magneto-thermal therapy suppressed the cancer growth more efficiently than treatment with either drug or supermolecule alone.