Enhanced cytotoxicity to lung cancer cells by mitochondrial delivery of camptothecin.

Delivering traditional DNA-damaging anticancer drugs into mitochondria to damage mitochondria is a promising chemotherapy strategy. The impermeability of this mitochondrial inner membrane, however, impedes the delivery of drug molecules that could impact other important biological roles of mitochondria. Herein, the prodrug camptothecin (CPT)-triphenylphosphine (TPP) modified with hyaluronic acid (HA) via electrostatic adsorption (HA/CPT-TPP, HCT) was used to mediate the mitochondrial accumulation of CPT. These nanoparticles (NPs) showed enhanced drug accumulation in cancer cells through tumor targeting. HCT entered acidic lysosomes through endosomal transport, HA was degraded by hyaluronidase (HAase) in acidic lysosomes, and the positively charged CPT-TPP was exposed and accumulated fully in the mitochondria. Subsequently, CPT-TPP significantly disrupted the mitochondrial structure and damaged mitochondrial function, leading to increased reactive oxygen species (ROS) levels and energy depletion. Finally, HCT enhanced lung cancer cell apoptosis via the activation of caspase-3 and caspase-9. Furthermore, greatly increased tumor growth inhibition was observed in nude mice bearing A549 xenograft tumors after the administration of HCT via tail injection. This study demonstrated that the mitochondria-targeted delivery of CPT may be a promising antitumor therapeutic strategy.

A redox-responsive self-assembling COA-4-arm PEG prodrug nanosystem for dual drug delivery suppresses cancer metastasis and drug resistance by downregulating hsp90 expression.

Metastasis and resistance are main causes to affect the outcome of the current anticancer therapies. Heat shock protein 90 (Hsp90) as an ATP-dependent molecular chaperone takes important role in the tumor metastasis and resistance. Targeting Hsp90 and downregulating its expression show promising in inhibiting tumor metastasis and resistance. In this study, a redox-responsive dual-drug nanocarrier was constructed for the effective delivery of a commonly used chemotherapeutic drug PTX, and a COA-modified 4-arm PEG polymer (4PSC) was synthesized. COA, an active component in oleanolic acid that exerts strong antitumor activity by downregulating Hsp90 expression, was used as a structural and functional element to endow 4PSC with redox responsiveness and Hsp90 inhibitory activity. Our results showed that 4PSC/PTX nanomicelles efficiently delivered PTX and COA to tumor locations without inducing systemic toxicity. By blocking the Hsp90 signaling pathway, 4PSC significantly enhanced the antitumor effect of PTX, inhibiting tumor proliferation and invasiveness as well as chemotherapy-induced resistance in vitro. Remarkable results were further confirmed in vivo with two preclinical tumor models. These findings demonstrate that the COA-modified 4PSC drug delivery nanosystem provides a potential platform for enhancing the efficacy of chemotherapies.

Biomimetic metal-organic frameworks navigated biological bombs for efficient lung cancer therapy.

The rising risk of lung cancer has become a primary global concern with high mortality and mobility. Presently, clinically used anticancer drugs show limited efficacy and significant side effects. A new generation of anticancer weapons is in great demand for lung cancer therapy. Herein, we have developed a novel style of biomimetic zeolitic imidazolate framework-8 (ZIF-8) based on the merits of cell membranes derived from human bone marrow mesenchymal stem cells (hBMSCs), which can navigate biological bombs herpes simplex virus type I thymidine kinase-encoded plasmids (pHSVtk) and ganciclovir (GCV) to treat lung cancer. The biological bomb-loaded structure can kill transfected lung cancer cells and neighboring lung cancer cells through the "bystander effect," which induces efficient suppression of lung cancer both in vitro and in vivo. The biomimetic nanoparticles show an enhanced circulation lifetime and drug accumulation in the tumor tissues and significantly inhibit the tumors. We have developed a straightforward approach to deliver biological bombs with biomimetic metal-organic frameworks for efficient lung cancer therapy. To the best of our knowledge, this is the first report of such a strategy for lung cancer therapy.

Coassembling functionalized glycopolypeptides to prepare pH-responsive self-indicating nanocomplexes to manipulate self-assembly/drug delivery and visualize intracellular drug release.

The pH-responsive polymeric micelles (PMs) have been widely used as smart nano drug delivery systems to treat tumors. However, synchronously manipulating these PMs' self-assembly properties, drug release dynamics and tracing their pH-dependent intracellular fate remain challenges. Herein, we have first synthesized hyaluronic acid (HA) based glycopolypeptides modified by tetraphenylethylene (TPE) and a pH-sensitive doxorubicin (DOX) prodrug through Diels-Alder reaction, respectively. Then, the pH-responsive nanocomplexes (NCs) were prepared by coassembling the two obtained glycopolypeptides with different formulations. Controllable size within the range of 60-125 nm and morphologies like spherical, vesicular and oblate micelles can be easily accomplished by using this method; High drug encapsulating and loading efficiency can be easily realized and adjusted within a range of 86-97% and 7-25%, respectively; Acid sensitive drug release dynamics of these NCs are also tunable by using this way. Additionally, the programmed drug release induced by subtle pH variations can be extracellularly self-indicated by detecting the blue AIE changes of the TPE units through fluorescence resonance energy transfer (FRET) effect between DOX and TPE. More importantly, the dynamic pH-triggered DOX release can be easily traced inside the tumor cells by visualizing blue emission changes of the TPE through the FRET effect. In addition, both the size and the shape can affect the endocytic routes of the NCs; The HA coated NCs targeting the tumor cells can effectively inhibit the proliferation of the HeLa cells. This work can provide a new route to acquire the stimuli-responsive self-indicating PMs with the ability to adjust their self-assembly properties and their pH-triggered drug release dynamics, and even to simultaneously visualize the PMs' intracellular fate in a real-time.

Black phosphorus nanoparticles for dual therapy of non-small cell lung cancer.

Lung cancer remains one of the leading causes of death in humans. Gefitinib is an inhibitor of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) commonly used to suppress tumour growth. However, constantly use of gefitinib results in drug-resistance, reduced efficacy and undesired side effects. To circumvent these drawbacks, targeted and photothermal therapies have emerged as effective strategies. Herein, we are first to adopt a black phosphorus (BP) nanoparticle-based novel delivering strategy by combining gefitinib and cancer cytomembrane to treat non-small cell lung cancer (NSCLC). In these gefitinib-containing nano-carriers, cyanine 5 (Cy5) biotin-labelled BP was incorporated with cancer membrane and then consists of a nanomaterial (BPGM), which enabled to deliver gefitinib to the tumours effectively. The combination of BPGM showed reinforcing effects to suppress NSCLC cells and xenograft tumours without apparent adverse effects both in vitro and in vivo. BPGM facilitated the delivery of gefitinib to tumour tissue and extended its retention time within tumours. These studies thus suggest that BP may serve as novel delivery strategy for lung cancer.

Efficient Photoacoustic Imaging With Biomimetic Mesoporous Silica-Based Nanoparticles.

Indocyanine green (ICG), a near-infrared (NIR) fluorescent dye approved by the Food and Drug Administration (FDA), has been extensively used as a photoacoustic (PA) probe for PA imaging. However, its practical application is limited by poor photostability in water, rapid body clearance, and non-specificity. Herein, we fabricated a novel biomimetic nanoprobe by coating ICG-loaded mesoporous silica nanoparticles with the cancer cell membrane (namely, CMI) for PA imaging. This probe exhibited good dispersion, large loading efficiency, good biocompatibility, and homologous targeting ability to Hela cells in vitro. Furthermore, the in vivo and ex vivo PA imaging on Hela tumor-bearing nude mice demonstrated that CMI could accumulate in tumor tissue and display a superior PA imaging efficacy compared with free ICG. All these results demonstrated that CMI might be a promising contrast agent for PA imaging of cervical carcinoma.

The use of amphiphilic copolymer in the solid dispersion formulation of nimodipine to inhibit drug crystallization in the release media: Combining nano-drug delivery system with solid preparations.

Solid dispersion is a widely used method to improve the dissolution and oral bioavailability of water-insoluble drugs. However, due to the strong hydrophobicity, the drug crystallization in the release media after drug dissolution and the resulted decreased drug absorption retards the use of solid dispersions. It is widely known that the amphiphilic copolymer can encapsulate the hydrophobic compounds and help form stable nano-dispersions in water. Inspired by this, we tried to formulate the solid dispersion of nimodipine by using amphipathic copolymer as one of the carriers. Concerning the solid dispersions, there are many important points involved in these formulations, such as the miscibility between the drug and the carriers, the storage stability of solid dispersions, the dissolution enhancement and so on. In this study, a systemic method is proposed. In details, the supersaturation test and the glass transition temperature (Tg) measurement to predict the crystallization inhibition, the ratios of different components and the storage stability, the interactions among the components were investigated in detail by nuclear magnetic resonance (1H NMR) and isothermal titration calorimetry (ITC) and, the final dissolution and oral bioavailability enhancement. It was found that the amphiphilic copolymer used in the solid dispersion encouraged the formation the drug loading micelles in the release media and, finally, the problem of drug crystallization in the dissolution process was successfully solved.

Redox-responsive nanoparticles from disulfide bond-linked poly-(N-ε-carbobenzyloxy-l-lysine)-grafted hyaluronan copolymers as theranostic nanoparticles for tumor-targeted MRI and chemotherapy.

Redox-responsive theranostic nanoparticles based on poly-(N-ε-carbobenzyloxy-l-lysine) (PZLL) grafted hyaluronan (HA) (HA-g-SS-PZLL) copolymers were constructed for hepatocellular carcinoma diagnosis and therapy. These hyaluronan derivatives formed nanoparticles via a self-assembly process in aqueous solution at low concentration. Theranostic nanoparticles were obtained after loading hydrophobic doxorubicin (DOX) and superparamagnetic iron oxide (SPIO) into the core of the nanoparticles via a dialysis method. Theranostic nanoparticles exhibited redox triggered DOX release behavior, and faster DOX released from theranostic nanoparticles was detected under a reducing environment compared with slow DOX release under a normal physiological environment. Confocal laser scanning microscopy (CLSM), flow cytometry and Prussian blue staining against HepG2 cells demonstrated that HA-g-SS-PZLL theranostic nanoparticles were capable of delivering DOX and SPIO into the cells. The analysis of the anticancer effect revealed that the HA-g-SS-PZLL theranostic nanoparticles shown higher cytotoxicity against HepG2 cells than DOX-loaded HA-g-PZLL nanoparticles. In vitro T2 magnetic resonance imaging (MRI) results exhibited that theranostic nanoparticles showed a good contrast enhancement effect, and the r2 relaxivity value was approximately 231 Fe mM-1 s-1. Finally, the theranostic nanoparticles acted as nanoprobes for HepG2 tumor-bearing BALB/c mice for in vivo MRI. Therefore, HA-g-SS-PZLL copolymers have great potential as theranostic nanoparticles for tumor-targeted diagnosis and treatment.

Self-Delivery Photodynamic Nanoinhibitors for Tumor Targeted Therapy and Metastasis Inhibition.

Simultaneous inhibitions of primary tumor growth and distant metastasis are very critical for cancer patients to improve their survival and cure rates. Although photodynamic therapy (PDT) shows great potential for primary tumor treatment, it often exacerbates hypoxia with a reduced therapeutic efficacy and subsequently contributes to carcinoma progression and metastatic dissemination. To solve these issues, self-delivery photodynamic nanoinhibitors (PNI) are developed for tumor targeted therapy and metastasis inhibition. PNI are composed of a carbonic anhydrase inhibitor (CAi), a hydrophilic poly(ethylene glycol) (PEG) linker, and a hydrophobic photosensitizer protoporphyrin IX (PpIX). Such self-delivery design of PNI avoids the premature release and heterogeneous distribution of CAi and PpIX to enhance the availability and synergism. Briefly, the CAi-based nanoinhibitors improve the selectivity of CAi for specific recognition and inhibition of tumor-associated isoform carbonic anhydrase (CA) IX, which would not only facilitate the targeted drug delivery of PNI but also regulate the hypoxia-induced signaling cascade and PDT resistance. Benefiting from the CA IX inhibition and targeted PDT, PNI exhibit a robust inhibitory effect on primary tumor growth and distant metastasis. This targeted self-delivery strategy sheds light on the photosensitizer-based molecular design to overcome the defect of traditional PDT.

Electrospun Poly (Aspartic Acid)-Modified Zein Nanofibers for Promoting Bone Regeneration.

BACKGROUND: Critical-sized bone defects raise great challenges. Zein is of interest for bone regeneration, but it has limited ability to stimulate cell proliferation. In this regard, a poly (aspartic acid) (PAsp)-zein hybrid is promising, as PAsp can promote rat bone marrow stromal cell (rBMSCs) proliferation and osteogenic differentiation. This research aimed to develop electrospun PAsp-modified zein nanofibers to realize critical-sized bone defects repair. METHODS: Three groups of PAsp-modified zein nanofibers were prepared, they were PAsp grafting percentages of 0% (zein), 5.32% (ZPAA-1), and 7.63% (ZPAA-2). Using rBMSCs as in vitro cell model and SD rats as in vivo animal model, fluorescence staining, SEM, CCK-8, ALP, ARS staining, µCT and histological analysis were performed to verify the biological and osteogenic activities for PAsp-modified zein nanofibers. RESULTS: As the Asp content increased from 0% to 7.63%, the water contact angle decreased from 129.8 ± 2.3° to 105.5 ± 2.5°. SEM, fluorescence staining and CCK-8 assay showed that ZPAA-2 nanofibers had a superior effect on rBMSCs spreading and proliferation than did zein and ZPAA-1 nanofibers, ALP activity and ARS staining showed that ZPAA-2 can improve rBMSCs osteogenic differentiation. In vivo osteogenic activities was evaluated by µCT analysis, HE, Masson and immunohistochemical staining, indicating accelerated bone formation in ZPAA-2 SD rats after 4 and 8 weeks treatment, with a rank order of ZPAA-2 > ZPAA-1 > zein group. Moreover, the semiquantitative results of the Masson staining revealed that the maturity of the new bone was higher in the ZPAA-2 group than in the other groups. CONCLUSION: Electrospun PAsp-modified zein can provide a suitable microenvironment for osteogenic differentiation of rBMSCs, as well as for bone regeneration; the optimal membrane appears to have a PAsp grafting percentage of 7.63%.

Zein/gelatin/nanohydroxyapatite nanofibrous scaffolds are biocompatible and promote osteogenic differentiation of human periodontal ligament stem cells.

In bone tissue engineering, it is important for biomaterials to promote the osteogenic differentiation of stem cells to achieve tissue regeneration. Therefore, it is critical to develop biomaterials with excellent cytocompatibility and osteoinductive ability. In our previous study, we found a zein/gelatin electrospinning scaffold with good biocompatibility, but low osteoinductive ability for human periodontal ligament stem cells (hPDLSCs). Therefore, herein, we fabricated novel zein/gelatin/nanohydroxyapatite (zein/gelatin/nHAp) nanofibrous membranes to overcome the drawbacks of the zein/gelatin scaffold. The results showed that the surface wettability of the zein/gelatin/nHAp nanofiber membranes was increased. Moreover, the inclusion of nHAp facilitated the attachment, proliferation, and osteogenic differentiation of hPDLSCs. Overall, the zein/gelatin/nHAp nanofiber membranes showed good biocompatibility and osteoinductive activity for hPDLSCs in vitro and in vivo; this suggested potential applications of these membranes in bone tissue engineering.

Electrospun Zein/Gelatin Scaffold-Enhanced Cell Attachment and Growth of Human Periodontal Ligament Stem Cells.

Periodontitis is a widespread dental disease affecting 10 to 15% of worldwide adult population, yet the current treatments are far from satisfactory. The human periodontal ligament stem cell is a promising potential seed cell population type in cell-based therapy and tissue regeneration, which require appropriate scaffold to provide a mimic extracellular matrix. Zein, a native protein derived from corn, has an excellent biodegradability, and therefore becomes a hotspot on research and application in the field of biomaterials. However, the high hydrophobicity of zein is unfavorable for cell adhesion and thus greatly limits its use. In this study, we fabricate co-electrospun zein/gelatin fiber scaffolds in order to take full advantages of the two natural materials and electrospun fiber structure. Zein and gelatin in four groups of different mass ratios (100:00, 100:20, 100:34, 100:50), and dissolved the mixtures in 1,1,1,3,3,3-hexafluoro-2-propanol, then produced membranes by electrospinning. The results showed that the scaffolds were smooth and homogeneous, as shown in scanning electron micrographs. The diameter of hybrid fibers was increased from 69 ± 22 nm to 950 ± 356 nm, with the proportion of gelatin increase. The cell affinity of zein/gelatin nanofibers was evaluated by using human periodontal ligament stem cells. The data showed that hydrophilicity and cytocompatibility of zein nanofibers were improved by blended gelatin. Taken together, our results indicated that the zein/gelatin co-electrospun fibers had sufficient mechanical properties, satisfied cytocompatibility, and can be utilized as biological scaffolds in the field of tissue regeneration.