Tumour microenvironment-responsive lipoic acid nanoparticles for targeted delivery of docetaxel to lung cancer

Antimicrobial capping agents on silver nanoparticles made via green method using natural products from banana plant waste

Herein, we investigated the phytochemical composition and antibacterial activities of the organic layers from biosynthesized silver nanoparticles (AgNPs). AgNPs were synthesized using Musa paradisiaca and Musa sapientum extracts. UV-vis absorption in the 400-450 nm range indicated surface plasmonic resonance peak of AgNPs. Samples analyses using dynamic light scattering and transmission electron microscopy revealed the presence of particles within nanometric ranges, with sizes of 30-140 nm and 8-40 nm, respectively. Fourier transform infrared (FTIR) unveiled the presence of several organic functional groups on the surface of AgNPs, indicating the presence of phytochemicals from plant extracts. Thin layer chromatography (TLC) of the phytochemicals (capping agents) from AgNPs identified multiple groups of secondary metabolites. These phytochemical capping agents exhibited antibacterial activities against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, with minimum inhibitory concentrations ranging from 62.5 to 1000 µg/mL. Regardless of the bacterial species or plant parts (leaves or pseudo-stems), capping agents from M. sapientum nanoparticles displayed significantly enhanced antibacterial effectiveness compared to all other samples, including the raw plant extracts and biosynthesized capped and uncapped AgNPs. These results suggest the presence of antimicrobial phytochemicals on biosynthesized AgNPs, highlighting the promise of green nanoparticle synthesis as a valuable approach in bioprospecting antimicrobial agents.

Organelle-oriented nanomedicines in tumor therapy: Targeting, escaping, or collaborating?

Precise tumor therapy is essential for improving treatment specificity, enhancing efficacy, and minimizing side effects. Targeting organelles is a key strategy for achieving this goal and is a frontier research area attracting a considerable amount of attention. The concept of organelle targeting has a significant effect on the structural design of the nanodrugs employed. Most notably, the intricate interactions among different organelles in a tumor cell essentially create a unified system. Unfortunately, this aspect might have been somewhat overlooked when existing organelle-targeting nanodrugs were designed. In this review, we underscore the synergistic relationship among the various organelles and advocate for a holistic view of organelle-targeting design. Through the integration of biology and material science, recent advancements in organelle targeting, escaping, and collaborating are consolidated to offer fresh perspectives for the development of antitumor nanomedicines.

Novel combinational nanomedicines, liposomes, to tackle breast cancer

AIMS

Doxorubicin (DOX), a potent chemotherapeutic, is a commonly prescribed treatment for breast cancer, but is limited by severe organ toxicity. Therefore, more effective therapies are required. This study developed a novel DOX-liposomes (LipDOX-ALA-AA) co-loaded with alpha-lipoic-acid (ALA) and ascorbic-acid (AA) to enhance antineoplastic effect.

METHODS

Liposomes were fabricated using a microfluidic-system with a DSPClipid:Cholesterol ratio of 1:1 and a flow rate ratio of 5:1. Liposomes were investigated using various-techniques such-as dynamic light scattering to measure liposomes' size and charge; and UV-spectroscopy to determine DOX-encapsulation-efficiency, EE. Cytotoxicity assays used various cell-lines.

RESULTS

Data revealed that LipDOX-ALA-AA had diameter of 79.0 ± 0.3 nm, with narrow size distribution, and zeta-potential of -4.0 ± 1.2. DOX-EE exceeded 95%, drug load was 0.5 mg/105.5 mg total content, drug release followed a biphasic pattern. Cytotoxicity assay showed activity (p < 0.05) against breast cancer cell-lines with reduced nephrotoxicity compared to Doxosome.

CONCLUSION

This novel formulation (LipDOX-ALA-AA) offers a promise in breast cancer therapy.

Exploring lung cancer microenvironment: pathways and nanoparticle-based therapies

Lung cancer stands out as a significant global health burden, with staggering incidence and mortality rates primarily linked to smoking and environmental carcinogens. The tumor microenvironment (TME) emerges as a critical determinant of cancer progression and treatment outcomes, comprising a complex interplay of cells, signaling molecules, and extracellular matrix. Through a comprehensive literature review, we elucidate current research trends and therapeutic prospects, aiming to advance our understanding of TME modulation strategies and their clinical implications for lung cancer treatment. Dysregulated immune responses within the TME can facilitate tumor evasion, limiting the efficacy of immune checkpoint inhibitors (ICI). Consequently, TME modulation strategies have become potential avenues to enhance therapeutic responses. However, conventional TME-targeted therapies often face challenges. In contrast, nanoparticle (NP)-based therapies offer promising prospects for improved drug delivery and reduced toxicity, leveraging the enhanced permeability and retention (EPR) effect. Despite NP design and delivery advancements, obstacles like poor tumor cell uptake and off-target effects persist, necessitating further optimization. This review underscores the pivotal role of TME in lung cancer management, emphasizing the synergistic potential of immunotherapy and nano-therapy.

Nanotechnological Approaches to Enhance the Potential of α-Lipoic Acid for Application in the Clinic

α-lipoic acid is a naturally occurring compound with potent antioxidant properties that helps protect cells and tissues from oxidative stress. Its incorporation into nanoplatforms can affect factors like bioavailability, stability, reactivity, and targeted delivery. Nanoformulations of α-lipoic acid can significantly enhance its solubility and absorption, making it more bioavailable. While α-lipoic acid can be prone to degradation in its free form, encapsulation within nanoparticles ensures its stability over time, and its release in a controlled and sustained manner to the targeted tissues and cells. In addition, α-lipoic acid can be combined with other compounds, such as other antioxidants, drugs, or nanomaterials, to create synergistic effects that enhance their overall therapeutic benefits or hinder their potential cytotoxicity. This review outlines the advantages and drawbacks associated with the use of α-lipoic acid, as well as various nanotechnological approaches employed to enhance its therapeutic effectiveness, whether alone or in combination with other bioactive agents. Furthermore, it describes the engineering of α-lipoic acid to produce poly(α-lipoic acid) nanoparticles, which hold promise as an effective drug delivery system.

Cholesterol-modified sphingomyelin chimeric lipid bilayer for improved therapeutic delivery

Cholesterol (Chol) fortifies packing and reduces fluidity and permeability of the lipid bilayer in vesicles (liposomes)-mediated drug delivery. However, under the physiological environment, Chol is rapidly extracted from the lipid bilayer by biomembranes, which jeopardizes membrane stability and results in premature leakage for delivered payloads, yielding suboptimal clinic efficacy. Herein, we report a Chol-modified sphingomyelin (SM) lipid bilayer via covalently conjugating Chol to SM (SM-Chol), which retains membrane condensing ability of Chol. Systemic structure activity relationship screening demonstrates that SM-Chol with a disulfide bond and longer linker outperforms other counterparts and conventional phospholipids/Chol mixture systems on blocking Chol transfer and payload leakage, increases maximum tolerated dose of vincristine while reducing systemic toxicities, improves pharmacokinetics and tumor delivery efficiency, and enhances antitumor efficacy in SU-DHL-4 diffuse large B-cell lymphoma xenograft model in female mice. Furthermore, SM-Chol improves therapeutic delivery of structurally diversified therapeutic agents (irinotecan, doxorubicin, dexamethasone) or siRNA targeting multi-drug resistant gene (p-glycoprotein) in late-stage metastatic orthotopic KPC-Luc pancreas cancer, 4T1-Luc2 triple negative breast cancer, lung inflammation, and CT26 colorectal cancer animal models in female mice compared to respective FDA-approved nanotherapeutics or lipid compositions. Thus, SM-Chol represents a promising platform for universal and improved drug delivery.

Mechanisms of Degradation for Polydisulfides: Main Chain Scission, Self-Immolation, Or Chain Transfer Depolymerization

Organic polydisulfides hold immense potential for the design of recyclable materials. Of these, polymers based on lipoic acid are attractive, as they are based on a natural, renewable resource. Herein, we demonstrate that reductive degradation of lipoic acid polydisulfides is a rapid process whereby the quantity of added initiator relative to the polymer content defines the mechanism of polymer degradation, through the main chain scission, self-immolation, or "chain transfer" depolymerization. The latter mechanism is defined as the one during which a thiol group released through the decomposition of one polydisulfide chain initiates depolymerization of the neighbor macromolecule. The chain transfer mechanism afforded the highest yields of recovery of the monomer in its pristine form, and just one molecule of the reducing agent to initiate polymer degradation afforded recovery of over 50% of the monomer. These data are important to facilitate the development of polymer recycling and monomer reuse schemes.

Traditionally used medicinal plants mediate the biosynthesis of silver nanoparticles: methodological, larvicidal, and ecotoxicological approach

It has been shown that vegetal species constitute an alternative natural source for the biosynthesis of new nanomaterials. Thus, aiming to expand knowledge about the potential use of plants in the fabrication of metallic nanomaterials, we aimed to synthesize silver nanoparticles (AgNPs) from phyto-formulation (PF) of ten commonly used medicinal plants. Our results demonstrate the formation of spherical, stable, polycrystalline AgNPs with a diameter of 8.42 nm to 18.40 nm, whose biosynthesis confirmation was performed via UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM)-energy dispersive X-ray spectroscopy (EDS) mapping, high-resolution transmission electron microscopy (HR-TEM), dynamic light scattering (DLS), and zeta potential studies. Furthermore, we demonstrated that the biosynthesized AgNPs showed larvicidal activity against Aedes aegypti and Anopheles stephensi larvae, with the histopathology findings from the fourth instar larval stage validating such larvicidal toxicity. The histological examinations showed severe degradation of the larvae's hindgut, epithelial cells, midgut, and cortical area. However, the PF extract and the biosynthesized AgNPs showed high ecotoxicity in Danio rerio larvae exposed to different concentrations. The treatments induced changes in hatchability percentage, animal growth, and heartbeat. Therefore, despite supporting the potential of PF (from ten plant species) as a raw material source for AgNPs biosynthesis, our study also sheds light on its ecotoxicological potential, suggesting that more comprehensive assessments of the ecotoxicity of biosynthesized would be performed before its application in different sectors.

Mussel-Inspired, Underwater Self-Healing Ionoelastomers Based on α-Lipoic Acid for Iontronics

Weak adhesion and lack of underwater self-healability hinder advancing soft iontronics particularly in wet environments like sweaty skin and biological fluids. Mussel-inspired, liquid-free ionoelastomers are reported based on seminal thermal ring-opening polymerization of a biomass molecule of α-lipoic acid (LA), followed by sequentially incorporating dopamine methacrylamide as a chain extender, N,N'-bis(acryloyl) cystamine, and lithium bis(trifluoromethanesulphonyl) imide (LiTFSI). The ionoelastomers exhibit universal adhesion to 12 substrates in both dry and wet states, superfast self-healing underwater, sensing capability for monitoring human motion, and flame retardancy. The underwater self-repairabilitiy prolongs over three months without deterioration, and sustains even when mechanical properties greatly increase. The unprecedented underwater self-mendability benefits synergistically from the maximized availability of dynamic disulfide bonds and diverse reversible noncovalent interactions endowed by carboxylic groups, catechols, and LiTFSI, along with the prevented depolymerization by LiTFSI and tunability in mechanical strength. The ionic conductivity reaches 1.4 × 10^-6 -2.7 × 10^-5 S m^-1 because of partial dissociation of LiTFSI. The design rationale offers a new route for creating a wide range of LA- and sulfur-derived supramolecular (bio)polymers with superior adhesion, healability, and other functionalities, and thus has technological implications for coatings, adhesives, binders and sealants, biomedical engineering and drug delivery, wearable and flexible electronics, and human-machine interfaces.

Integrated Platform of Oxygen Self-enriched Nanovesicles: SP94 Peptide-directed Chemo/sonodynamic Therapy for Liver Cancer

Hepatocellular carcinoma (HCC) is a most common primary liver cancer among the most deadly malignancies. Selectively killing the cancer cells within the liver urgently requires the novel treatment strategies. The combination of sonodynamic therapy (SDT) and chemotherapy based on the nanotechnology have achieved some achievements in the HCC treatments. However, off-targeting drug delivery to healthy cells and the hypoxic microenvironment in the solid tumors frustrate the efforts to the combined strategy. The hypoxic microenvironment restrains the generation of ROS, leading to the decreased effects of SDT. To improve the clinical outcomes of chemo/SDT strategy, we created a novel oxygen self-enriched active targeted nanovesicle (ICG-DOX NPs/PFH@SP94-Lip). SP94 peptide could enhance the selectivity of the nanovesicles to liver tumor cells rather than normal liver cells. Besides, an oxygen carrier, perfluorohexanes (PFH), was co-loaded into liposomes to increase the oxygen level in tumor tissue, thus improving the effects of SDT. The in vivo studies showed that the ICG-DOX NPs/PFH@SP94-Lip combined with the external US stimulation significantly inhibited effects on tumor growth. Therefore, this novel oxygen self-enriched chemo/SDT nanocomposites represents a proof-of-concept liver tumor treatment strategy.

Nanoparticles Based on Cross-Linked Poly(Lipoic Acid) Protect Macrophages and Cardiomyocytes from Oxidative Stress and Ischemia Reperfusion Injury

The control of radical damage and oxidative stress, phenomena involved in a large number of human pathologies, is a major pharmaceutical and medical goal. We here show that two biocompatible formulations of Pluronic-stabilized, poly (lipoic acid)-based nanoparticles (NP) effectively antagonized the formation of radicals and reactive oxygen species (ROS). These NPs, not only intrinsically scavenged radicals in a-cellular DPPH/ABTS assays, but also inhibited the overproduction of ROS induced by tert-Butyl hydroperoxide (t-BHP) in tumor cells (HeLa), human macrophages and neonatal rat ventricular myocytes (NRVMs). NPs were captured by macrophages and cardiomyocytes much more effectively as compared to HeLa cells and non-phagocytic leukocytes, eventually undergoing intracellular disassembly. Notably, NPs decreased the mitochondrial ROS generation induced by simulated Ischemia/Reperfusion Injury (IRI) in isolated cardiomyocytes. NPs also prevented IRI-triggered cardiomyocyte necrosis, mitochondrial dysfunction, and alterations of contraction-related intracellular Ca2+ waves. Hence, NPs appear to be an effective and cardiomyocyte-selective drug to protect against damages induced by post-ischemic reperfusion.

Nanomedicine Strategies for Management of Drug Resistance in Lung Cancer

Lung cancer (LC) is one of the leading causes of cancer occurrence and mortality worldwide. Treatment of patients with advanced and metastatic LC presents a significant challenge, as malignant cells use different mechanisms to resist chemotherapy. Drug resistance (DR) is a complex process that occurs due to a variety of genetic and acquired factors. Identifying the mechanisms underlying DR in LC patients and possible therapeutic alternatives for more efficient therapy is a central goal of LC research. Advances in nanotechnology resulted in the development of targeted and multifunctional nanoscale drug constructs. The possible modulation of the components of nanomedicine, their surface functionalization, and the encapsulation of various active therapeutics provide promising tools to bypass crucial biological barriers. These attributes enhance the delivery of multiple therapeutic agents directly to the tumor microenvironment (TME), resulting in reversal of LC resistance to anticancer treatment. This review provides a broad framework for understanding the different molecular mechanisms of DR in lung cancer, presents novel nanomedicine therapeutics aimed at improving the efficacy of treatment of various forms of resistant LC; outlines current challenges in using nanotechnology for reversing DR; and discusses the future directions for the clinical application of nanomedicine in the management of LC resistance.

"One-stitch" bioorthogonal prodrug activation based on cross-linked lipoic acid nanocapsules

Bioorthogonal prodrug activation is fascinating but suffers from staggered administration of prodrug and trigger, which would not only reduce the therapeutic effect but bring great inconvenience for clinical application. Herein, we report a new cross-linked lipoic acid nanocapsules (cLANCs) based two-component bioorthogonal nanosystem for "one-stitch" prodrug activation. Due to the reversible stability of cLANCs, the loaded prodrug and trigger cannot release in advance while can react upon arrival in the tumor tissue. Moreover, the cLANCs would be degraded into dihydrolipoic acid in tumor cells to potentiate the anticancer effect of the drug synthesized in situ. The data showed that the new bioorthogonal system held a killing effect 1.63 times higher than that of parent drug 3 against human colorectal tumor cells (HT29) and a tumor inhibitory rate 34.2% higher than that of 3 against HT29 tumor xenograft model with negligible side effects. The biodistribution study showed that the "one-stitch" prodrug activation exhibited a selective accumulation of 3 in the tumor tissue compared with free 3 group (34.2 μg vs 3.56 μg of 3/g of tissue). This two-component bioorthogonal nanosystem based on cross-linked lipoic acid nanocapsules constitutes the first example of "one-stitch" bioorthogonal prodrug activation.

Facile fabrication of robust, hyaluronic acid-surfaced and disulfide-crosslinked PLGA nanoparticles for tumor-targeted and reduction-triggered release of docetaxel

It is highly tempting to develop high-efficacy targeted nanotherapeutics based on FDA approved polymers like PLGA. Herein, we describe facile fabrication of robust, hyaluronic acid-surfaced and disulfide-crosslinked star-PLGA nanoparticles (HA-sPLGA XNPs) for targeted and reduction-triggered release of docetaxel (DTX), achieving markedly enhanced treatment of A549 lung tumor in vivo. HA-sPLGA XNPs carrying 5.2 wt.% DTX (DTX-HA-sPLGA XNPs) had a size of 105.5 ± 0.5 nm and great stability while almost completely released DTX under 10 mM glutathione. Confocal and flow cytometry experiments revealed fast cellular uptake of HA-sPLGA XNPs by CD44-overexpressing A549 cells. DTX-HA-sPLGA XNPs held much higher potency to A549 cells than DTX-loaded HA-surfaced and non-crosslinked star-PLGA nanoparticles (DTX-HA-sPLGA NPs), DTX-loaded HA-surfaced and non-crosslinked linear-PLGA nanoparticles (DTX-HA-lPLGA NPs), and free DTX (IC₅₀ = 0.18 versus 0.38, 1.21 and 0.83 µg DTX equiv./mL). Intriguingly, DTX-HA-sPLGA XNPs revealed a prolonged elimination half-life of 4.18 h and notable accretion of 9.49%ID/g in A549 tumor after 8 h injection. Accordingly, DTX-HA-sPLGA XNPs demonstrated significantly better suppression of subcutaneous A549 lung tumor than DTX-HA-PLGA NPs, DTX-HA-lPLGA NPs, and free DTX controls. HA-sPLGA XNPs with low toxicity and multi-functionality appear to be a unique targeted vehicle for chemotherapy of CD44-overexpressing tumors. STATEMENT OF SIGNIFICANCE: PLGA nanoparticles with superior safety and biodegradability are among the most advanced vehicles for therapeutic delivery. The efficacy of nanomedicines based on PLGA is, however, suboptimal, due to poor tumor cell selectivity and uptake, drug leakage, and slow drug release at the pathological site. It is highly desired to develop functional PLGA nanoparticles to improve their tumor-targeting ability and therapeutic efficacy. The sophisticated fabrication and potential toxicity concerns of reported novel PLGA nanoformulations, nevertheless, preclude their clinical translation. Here, we developed hyaluronic acid-surfaced and disulfide-crosslinked star-PLGA nanoparticles (HA-sPLGA XNPs) that enabled stable encapsulation and targeted delivery of docetaxel (DTX) to CD44+ A549 lung cancer cells in vitro and in vivo, affording markedly improved tumor accumulation and repression and lower side effects compared with free DTX control. Importantly, HA-sPLGA XNPs are based on fully biocompatible materials and comparably simple to fabricate. The evident tumor targetability and safety makes HA-sPLGA XNPs a unique and potentially translatable platform for chemotherapy of CD44+ cancers.

Poly(lipoic acid)-Based Nanoparticles as Self-Organized, Biocompatible, and Corona-Free Nanovectors

Herein we present an innovative approach to produce biocompatible, degradable, and stealth polymeric nanoparticles based on poly(lipoic acid), stabilized by a PEG-ended surfactant. Taking advantage of the well-known thiol-induced polymerization of lipoic acid, a universal and nontoxic nanovector consisted of a solid cross-linked polymeric matrix of lipoic acid monomers was prepared and loaded with active species with a one-step protocol. The biological studies demonstrated a high stability in biological media, the virtual absence of “protein” corona in biological fluids, the absence of acute toxicity in vitro and in vivo, complete clearance from the organism, and a relevant preference for short-term accumulation in the heart. All these features make these nanoparticles candidates as a promising tool for nanomedicine.

Redox-sensitive nanoparticles based on xylan-lipoic acid conjugate for tumor targeted drug delivery of niclosamide in cancer therapy

In this study, novel redox-sensitive nanoparticles based on xylan-lipoic acid (Xyl-LA) conjugate were developed for tumor targeted delivery of niclosamide (Nic) in cancer therapy. The niclosamide loaded xylan-lipoic acid conjugate nanoparticles (Xyl-LA/Nic NPs) showed redox responsive behaviour in presence of reductive glutathione (GSH), which indicate their suitability for intracellular drug release. The obtained Xyl-LA/Nic NPs exhibited uniform particle size (196 ± 1.64 nm), high loading capacity (~28.6 wt %) and excellent blood compatibility. The anticancer activity of the Niclosamide and the Xyl-LA/Nic NPs against the colon carcinoma cell lines (HCT-15, Colo-320) were evaluated by MTT assay and the overall results indicate that the Xyl-LA/Nic NPs significantly enhanced the therapeutic efficiency of niclosamide in cancer therapy.

Technetium-Radiolabeled Mannose-Functionalized Gold Nanoparticles as Nanoprobes for Sentinel Lymph Node Detection

Gold nanoparticles (AuNPs) are considered valuable nanomaterials for the design of radiolabeled nanoprobes for single-photon emission computed tomography (SPECT) imaging. Radiolabeled and functionalized AuNPs could improve lymphatic mapping by enhancing the radioactive signaling of individual particles in the sentinel node. In this study, an alternative method for functionalizing commercial AuNps with mannose is described. The chemical derivatization and biofunctionalization of AuNPs were performed with lipoic acid and mannose, respectively. Several levels of mannose were tested; the thiolate hydrazinonicotinamide-glycine-glycine-cysteine (HYNIC) molecule was also used for ^99mTc radiolabeling. Physicochemical characterization of this system includes U-V spectroscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, and transmission electron microscopy. The most stable nanoprobe, in terms of the aggregation, radiolabeling efficiency, and purity, was tested in a sentinel lymph node model in a rat by microSPECT/computed tomography (CT) imaging. The SPECT images revealed that ^99mTc-radiolabeled AuNPs functionalized with mannose can track and accumulate in lymph nodes in a similar way to the commercial ^99mTc-Sulfur colloid, commonly used in clinical practice for sentinel lymph node detection. These promising results support the idea that ^99mTc-AuNPs-mannose could be used as a SPECT contrast agent for lymphatic mapping.

Role of exosomal miR‑21 in the tumor microenvironment and osteosarcoma tumorigenesis and progression (Review)

Osteosarcoma is the most common bone tumor affecting both adolescents and children. Early detection is critical for the effective treatment of the disease. Derived from cancer cells, miR‑21 contained within exosomes in the tumor microenvironment may act on both cancer cells and the surrounding tumor microenvironment (TME), including immune cells, endothelial cells and fibroblasts. In human serum and plasm, the level of exosomal miR‑21 between osteosarcoma patients and healthy controls differs, supporting the role of miR‑21 as a biomarker for osteosarcoma. The involvement of a number of miR‑21 target genes in tumor progression suggests that miR‑21 may significantly affect the plasticity of cancer cells, leading to tumor progression, metastasis, angiogenesis and immune escape in osteosarcoma. Understanding the biogenesis and functions of exosomal miR‑21 is of great value for the diagnosis and therapy of cancer, including osteosarcoma. The present review discusses the role of miR‑21 in the tumor microenvironment, and in the development and progression of osteosarcoma, with an aim to summarize the functions of this miRNA in cancer.

SREBP1 siRNA enhance the docetaxel effect based on a bone-cancer dual-targeting biomimetic nanosystem against bone metastatic castration-resistant prostate cancer

Until recently, there have been limited options for patients with bone metastatic castration-resistant prostate cancer (BmCRPC) following the failure of or development of resistance to docetaxel (DTX), which is one of the frontline treatments. Sterol regulatory element-binding protein 1 (SREBP1) is reported to regulate abnormal lipid metabolism and to promote the progression and metastasis of prostate cancer (PCa). The siRNA interferes SREBP1 may provide an efficient treatment when combined with DTX. Methods: In this study, lipoic acid (LA) and cross-linked peptide-lipoic acid micelles were cross-linked (LC) for DTX and siSREBP1 delivery (LC/D/siR). Then, cell membrane of PCa cells (Pm) and bone marrow mesenchymal stem cells (Bm) were fused for cloaking LC/D/siR (PB@LC/D/siR). Finally, the synthesized PB@LC/D/siR was evaluated in vitro and in vivo. Results: PB@LC/D/siR is internalized in PCa cells by a mechanism of lysosome escape. Tumor targeting and bone homing studies are evaluated using bone metastatic CRPC (BmCRPC) models, both in vitro and in vivo. Moreover, the enhanced anti-proliferation, anti-migration and anti-invasion capacities of DTX- and siSREBP1- loaded PB@LC (PB@LC/D/siR) were observed in vitro. Furthermore, PB@LC/D/siR was able to suppress the growth of the tumor effectively with deep tumor penetration, high safety and good protection of the bone at the tumor site. Additionally, the mRNA levels and protein levels of SREBP1 and SCD1 were able to be significantly downregulated by PB@LC/D/siR. Conclusion: This study presented a bone-cancer dual-targeting biomimetic nanodelivery system for bone metastatic CRPC.

Nanoengineering multifunctional hybrid interfaces using adhesive glycogen nanoparticles

Amphiphilic phytoglycogen nanoparticles are used as building blocks for engineering multifunctional hybrid films with catalytic and sensing properties.

Core-matched nanoassemblies for targeted co-delivery of chemotherapy and photosensitizer to treat drug-resistant cancer

Emergence of drug resistance in tumors causes therapeutic failure or tumor relapse. Combination of chemotherapy and photodynamic therapy holds significant promise to treat drug-resistant tumors. However, stubborn hydrophobicity of photosensitizer (PS), low encapsulation efficiency and leaking problem of PS in organic carrier, and disparate physicochemical properties of PS and chemotherapeutics make the combination unachievable. Thus how to efficiently co-deliver the two functional agents to enable photo-chemotherapy seems to be one of the key challenges. Here, core-matched technology (CMT) was developed to realize efficient co-delivery of PS and chemotherapeutics, in which PS verteporfin (VP), tumor angiogenesis-targeting iNGR peptide and poly(lactic acid) (PLA) were respectively pre-modified with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and the conjugates self-assembled into iNGR-modified and VP conjugated nanoassemblies (iNGR-VP-NA) with chemotherapeutic agent docetaxel (DTX) loaded in the hydrophobic core. The obtained iNGR-VP-NA-DTX was characterized by mean size of 166.0 ± 9.2 nm and morphology of uniformly spherical shape. In vitro, with the assistance of laser, iNGR-VP-NA-DTX exhibited higher cellular uptake, stronger cytotoxicity in HUVEC cells, drug-resistant HCT-15 tumor cells and more effective inhibition of tube formation than iNGR-VP-NA-DTX without laser or VP-NA-DTX with laser. After intravenously injected into mice, through the near-infrared light emitted by VP, iNGR-VP-NA exhibited improved accumulation compared to VP-NA in drug-resistant HCT-15 tumor. Besides, iNGR-VP-NA-DTX with laser enhanced inhibition of angiogenesis and induced severe apoptosis and necrosis in tumor tissues along with minimal impact to normal areas. These evidences demonstrated that iNGR-VP-NA-DTX was of great potential to treat drug-resistant tumors via efficient angiogenesis-targeted photo-chemotherapy. STATEMENT OF SIGNIFICANCE: Combination of chemotherapy and photodynamic therapy is thought to be a potential approach to treat drug-resistant cancer. However, it is difficult to realize optimized photo-chemotherapy in one nano-system. Here, iNGR-modified nanoassemblies is created based on core-matched nanotechnology to realize targeted photo-chemotherapy. In this study, the improved co-loading of chemotherapy and photosensitizer in the nanoassemblies exerted a synergistic anti-tumor effect and the decoration with iNGR enhanced tumor-targeting efficiency. In the presence of laser irradiation, the nanoassemblies exhibited enhanced and targeted anti-tumor efficacy in drug-resistant HCT-15 tumor both in vitro and in vivo.

The effect of flow on blood oxygen level dependent (R* 2 ) MRI of orthotopic lung tumors

PURPOSE

Blood oxygen level dependent (BOLD) MRI based on R 2 * measurements can provide insights into tumor vascular oxygenation. However, measurements are susceptible to blood flow, which may vary accompanying a hyperoxic gas challenge. We investigated flow sensitivity by comparing R 2 * measurements with and without flow suppression (fs) in 2 orthotopic lung xenograft tumor models.

METHODS

H460 (n = 20) and A549 (n = 20) human lung tumor xenografts were induced by surgical implantation of cancer cells in the right lung of nude rats. MRI was performed at 4.7T after tumors reached 5 to 8 mm in diameter. A multiecho gradient echo MRI sequence was acquired with and without spatial saturation bands on each side of the imaging plane to evaluate the effect of flow on R 2 * . fs and non-fs R 2 * MRI measurements were interleaved during an oxygen breathing challenge (from air to 100% O₂ ). T 2 * -weighted signal intensity changes (ΔSI(%)) and R 2 * measurements were obtained for regions of interest and on a voxel-by-voxel basis and discrepancies quantified with Bland-Altman analysis.

RESULTS

Flow suppression affected ΔSI(%) and R 2 * measurements in each tumor model. Average discrepancy and limits of agreement from Bland-Altman analyses revealed greater flow-related bias in A549 than H460.

CONCLUSION

The effect of flow on R 2 * , and hence BOLD, was tumor model dependent with measurements being more sensitive in well-perfused A549 tumors.

IL-8 Secreted from M2 Macrophages Promoted Prostate Tumorigenesis via STAT3/MALAT1 Pathway

Prostate cancer (PCa) is a major health problem in males. Metastasis-associated with lung adenocarcinoma transcript-1 (MALAT1), which is overexpressed in PCa tissue, is associated with physiological and pathological conditions of PCa. M2 macrophages are major immune cells abundant in the tumor microenvironment. However, it remains unknown whether M2 macrophages are involved in the effects or not, and molecular mechanisms of MALAT1 on PCa progression have not yet been comprehensively explored. Here we reported that, M2 macrophages (PMA/IL-4 treated THP1) induced MALAT1 expression in PCa cell lines. Knockdown MALAT1 expression level in PCa cell lines inhibited cellular proliferation, invasion, and tumor formation. Further mechanistic dissection revealed that M2 macrophages secreted IL-8 was sufficient to drive up MALAT1 expression level via activating STAT3 signaling pathway. Additional chromatin immunoprecipitation (ChIP) and luciferase reporter assays displayed that STAT3 could bind to the MALAT1 promoter region and transcriptionally stimulate the MALAT1 expression. In summary, our present study identified the IL-8/STAT3/MALAT1 axis as key regulators during prostate tumorigenesis and therefore demonstrated a new mechanism for the MALAT1 transcriptional regulation.

Lipid nanoparticles loading triptolide for transdermal delivery: mechanisms of penetration enhancement and transport properties

Background

In recent years, nanoparticles (NPs) including nanostructured lipid carries (NLC) and solid lipid nanoparticles (SLN) captured an increasing amount of attention in the field of transdermal drug delivery system. However, the mechanisms of penetration enhancement and transdermal transport properties of NPs are not fully understood. Therefore, this work applied different platforms to evaluate the interactions between skin and NPs loading triptolide (TPL, TPL-NLC and TPL-SLN). Besides, NPs labeled with fluorescence probe were tracked after administration to investigate the dynamic penetration process in skin and skin cells. In addition, ELISA assay was applied to verify the in vitro anti-inflammatory effect of TPL-NPs.

Results

Compared with the control group, TPL-NPs could disorder skin structure, increase keratin enthalpy and reduce the SC infrared absorption peak area. Besides, the work found that NPs labeled with fluorescence probe accumulated in hair follicles and distributed throughout the skin after 1 h of administration and were taken into HaCaT cells cytoplasm by transcytosis. Additionally, TPL-NLC could effectively inhibit the expression of IL-4, IL-6, IL-8, IFN-γ, and MCP-1 in HaCaT cells, while TPL-SLN and TPL solution can only inhibit the expression of IL-6.

Conclusions

TPL-NLC and TPL-SLN could penetrate into skin in a time-dependent manner and the penetration is done by changing the structure, thermodynamic properties and components of the SC. Furthermore, the significant anti-inflammatory effect of TPL-NPs indicated that nanoparticles containing NLC and SLN could serve as safe prospective agents for transdermal drug delivery system.

Tumor microenvironment - Unknown niche with powerful therapeutic potential

Head and neck squamous cell carcinomas (HNSCC) are in a group of cancers that are the most resistant to treatment. The survival rate of HNSCC patients has been still very low since last 20 years. The existence of relationship between oncogenic and surrounding cells is probably the reason for a poor response to treatment. Fibroblasts are an important element of tumor stroma which increases tumor cells ability to proliferate. Another highly resistance, tumorigenic and metastatic cell population in tumor microenvironment are cancer initiating cells (CICs). The population of cancer initiating cells can be found regardless of differentiation status of cancer and they seem to be crucial for HNSCC development. In this review, we describe the current state of knowledge about HNSCC biological and physiological tumor microenvironment.

Targeted delivery of ginsenoside compound K using TPGS/PEG-PCL mixed micelles for effective treatment of lung cancer

Ginsenoside compound K (CK) is one of the effective ingredients in antitumor composition of ginsenoside. However, the poor water solubility and significant efflux have limited the widespread clinical use of CK. In this study, preparation of novel CK-loaded d-alpha-tocopheryl polyethylene glycol 1,000 succinate/poly(ethylene glycol)-poly(ε-caprolactone) mixed micelles (CK-M) is discussed to solve the above problems. Particle size, zeta potential, and morphology were characterized using dynamic light scattering and transmission electron microscopy. CK-M are spherical shaped with an average particle size of 53.07±1.31 nm with high drug loading of 11.19%±0.87% and entrapment efficiency of 94.60%±1.45%. Water solubility of CK was improved to 3.78±0.09 mg/mL, which was ~107.35 times higher than free CK. A549 and PC-9 cells were used to evaluate in vitro cytotoxicity and cellular uptake. IC₅₀ values of CK-M in A549 and PC-9 cells (24 h) were 25.43±2.18 and 18.35±1.90 μg/mL, respectively. Enhanced cellular uptake of CK-M was observed in both cells. Moreover, CK-M promoted tumor cell apoptosis, inhibited tumor cell invasion, metastasis, and efflux through regulation of Bax, Bcl-2, matrix metalloproteinase-2, Caspase-3, and P-glycoprotein. In vivo imaging indicated that CK-M has excellent tumor targeting effect within 24 h, and the relative tumor inhibition rate of CK-M was 52.04%±4.62% compared with control group (P<0.01). Thus, CK-M could be an appropriate delivery agent for enhanced solubility and antitumor effect of CK.

Enhanced photothermal therapy of biomimetic polypyrrole nanoparticles through improving blood flow perfusion

In this study, we reported a strategy to improve delivery efficiency of a long-circulation biomimetic photothermal nanoagent for enhanced photothermal therapy through selectively dilating tumor vasculature. By using a simply nanocoating technology, a biomimetic layer of natural red blood cell (RBC) membranes was camouflaged on the surface of photothermal polypyrrole nanoparticles (PPy@RBC NPs). The erythrocyte-mimicking PPy NPs inherited the immune evasion ability from natural RBC resulting in superior prolonged blood retention time. Additionally, excellent photothermal and photoacoustic imaging functionalities were all retained attributing to PPy NPs cores. To further improve the photothermal outcome, the endothelin A (ET_A) receptor antagonist BQ123 was jointly employed to regulate tumor microenvironment. The BQ123 could induce tumor vascular relaxation and increase blood flow perfusion through modulating an ET-1/ET_A transduction pathway and blocking the ET_A receptor, whereas the vessel perfusion of normal tissues was not altered. Through our well-designed tactic, the concentration of biomimetic PPy NPs in tumor site was significantly improved when administered systematically. The study documented that the antitumor efficiency of biomimetic PPy NPs combined with specific antagonist BQ123 was particularly prominent and was superior to biomimetic PPy NPs (P < 0.05) and PEGylated PPy NPs with BQ123 (P < 0.01), showing that the greatly enhanced photothermal treatment could be achieved with low-dose administration of photothermal agents. Our findings would provide a promising procedure for other similar enhanced photothermal treatment by blocking ET_A receptor to dramatically increase the delivery of biomimetic photothermal nanomaterials.

Calcium phosphate-quercetin nanocomposite (CPQN): A multi-functional nanoparticle having pH indicating, highly fluorescent and anti-oxidant properties

Calcium phosphate quercetin nanocomposite (CPQN) i.e., quercetin entrapped in calcium phosphate nanoparticle was synthesized by a precipitation method at 80°C, taking ammonium hydrogen phosphate, calcium nitrate and quercetin as precursors and sodium citrate as stabilizer. The nanocomposite suspension had different color at different pH values, a property that could render the nanoparticle a pH indicator. Besides color, the particles also had different size, shape, stability and quercetin content with change of pH. In addition, the CPQN was highly fluorescent having two sharp emission peaks at 460 and 497nm, when excited at 370nm; by this property it behaved as an effective fluorophore to label biological cell. Moreover, the nanocomposite had potential anti-oxidant property, for which mortality of mouse neuroblastoma cell N2A, by H₂O₂-induced oxidative stress, was found to be lowered by the pre-treatment of the cells with CPQN.