Dual pH-responsive multifunctional nanoparticles for targeted treatment of breast cancer by combining immunotherapy and chemotherapy.

In the present study, a dual pH-responsive multifunctional nanoparticle system was designed for combining immunotherapy and chemotherapy to treat breast cancer through targeting immune cells and cancer cells. A proven anti-tumor immune regulator, R848, was encapsulated with poly(L-histidine) (PHIS) to form PHIS/R848 nanocores. Doxorubicin (DOX) was conjugated to hyaluronic acid (HA) through an acid-cleavable hydrazone bond linkage to synthesize polymeric prodrug HA-DOX, which was subsequently coated outside PHIS/R848 nanocores to form HA-DOX/PHIS/R848 nanoparticles. Ionization of PHIS around pH 6.5 (a pH value close to that of tumor microenvironment) switched the nature of this material from hydrophobic to hydrophilic, and thus triggered the release of R848 to exert immunoregulatory action. The rupture of hydrazone bond in HA-DOX at about pH 5.5 (pH of endo/lysosomes) accelerated the release of DOX to exert cytotoxic effects. In immune cells, PHIS/R848 nanocores exhibited strong immunoregulatory activities similar to those induced by free R848. In breast cancer cells overexpressing CD44, HA-DOX was specially internalized by CD44-mediated endocytosis and significantly inhibited the cell growth. In 4T1 tumor-bearing mice, HA-DOX/PHIS/R848 nanoparticles showed excellent tumor-targeting ability and remarkably inhibited the tumor growth by regulating tumor immunity and killing tumor cells. In summary, this multifunctional nanoparticle system could deliver R848 and DOX respectively to tumor microenvironment and breast cancer cells to achieve synergistic effects of immunotherapy and chemotherapy against breast cancer. Combination of immunotherapy and chemotherapy is becoming a promising new treatment for cancer. The major challenge is to target cancer and immune cells simultaneously and specifically. In this study, a dual pH-responsive multifunctional nanoparticle system based on poly(L-histidine) and hyaluronic acid was designed for co-loading R848 (immune-regulator) and doxorubicin (chemotherapeutic drug) through different encapsulation modes. By responding to the acidic pHs of tumor microenvironment and intracellular organelles, this multifunctional nanoparticle system could release R848 extracellularly and deliver DOX targetedly to breast cancer cells, thus achieving synergistic effects of immunotherapy and chemotherapy against breast cancer.

Liu Y ，Qiao L ，Zhang S ，Wan G ，Chen B ，Zhou P ，Zhang N ，Wang Y ... -  《-》

Self-assembled pH-responsive hyaluronic acid-g-poly((L)-histidine) copolymer micelles for targeted intracellular delivery of doxorubicin.

Hyaluronic acid (HA) was conjugated with hydrophobic poly(l-histidine) (PHis) to prepare a pH-responsive and tumor-targeted copolymer, hyaluronic acid-g-poly(l-histidine) (HA-PHis), for use as a carrier for anti-cancer drugs. The effect of the degree of substitution (DS) on the pH-responsive behaviour of HA-PHis copolymer micelles was confirmed by studies of particles of different sizes. In vitro drug release studies demonstrated that doxorubicin (DOX) was released from HA-PHis micelles in a pH-dependent manner. In vitro cytotoxicity assays showed that all the blank micelles were nontoxic. However, MTT assay against Michigan Cancer Foundation-7 (MCF-7) cells (overexpressed CD44 receptors) showed that DOX-loaded micelles with a low PHis DS were highly cytotoxic. Cellular uptake experiments revealed that these pH-responsive HA-PHis micelles taken up in great amounts by receptor-mediated endocytosis and DOX were efficiently delivered into cytosol. Moreover, micelles with the lowest DS exhibited the highest degree of cellular uptake, which indicated that the micelles were internalized into cells via CD44 receptor-mediated endocytosis and the carboxylic groups of HA are the active binding sites for CD44 receptors. Endocytosis inhibition experiments and confocal images demonstrated that HA-PHis micelles were internalized into cells mainly via clathrin-mediated endocytosis and delivered to lysosomes, triggering release of DOX into the cytoplasm. These results confirm that the biocompatible pH-responsive HA-PHis micelles are a promising nanosystem for the intracellular targeted delivery of DOX.

Qiu L ，Li Z ，Qiao M ，Long M ，Wang M ，Zhang X ，Tian C ，Chen D ... -  《-》

Robust, active tumor-targeting and fast bioresponsive anticancer nanotherapeutics based on natural endogenous materials.

The clinical success of cancer nanomedicines critically depends on availability of simple, safe and highly efficient nanocarriers. Here, we report that robust and multifunctional nanoparticles self-assembled from hyaluronic acid-g-poly(γ-benzyl-l-glutamate)-lipoic acid conjugates achieve a remarkably high loading (up to 25.8wt.%) and active targeted delivery of doxorubicin (DOX) to human breast tumor xenograft in vivo. DOX-loaded nanoparticles following auto-crosslinking (DOX-CLNPs) are highly stable with little drug leakage under physiological conditions while quickly release ca. 92% DOX in 30h under a cytoplasmic-mimicking reductive environment. The in vitro assays reveal that DOX-CLNPs possess a superior selectivity and antitumor activity to clinically used pegylated liposomal doxorubicin hydrochloride (DOX-LPs) in CD44 receptor overexpressing MCF-7 human breast cancer cells. Strikingly, DOX-CLNPs exhibit a superb tolerated dose of over 100mg DOX equiv./kg, which is more than 5 times higher than DOX-LPs, and an extraordinary breast tumor accumulation of 8.6%ID/g in mice. The in vivo therapeutic studies in MCF-7 human breast tumor-bearing nude mice show that DOX-CLNPs effectively inhibit tumor growth, improve survival rate, and significantly decrease adverse effects as compared to DOX-LPs. DOX-CLNPs based on natural endogenous materials with high drug loading, great stability and CD44-targetability are highly promising for precision cancer chemotherapy. We demonstrate that with rational design, simple and multifunctional anticancer nanotherapeutics can be developed to achieve highly efficient and targeted cancer chemotherapy. Doxorubicin-loaded multifunctional nanoparticles based on hyaluronic acid-g-poly(γ-benzyl-l-glutamate)-lipoic acid conjugates exhibit a high drug loading, superior stability, fast bioresponsivity, high tolerability, and obvious selectivity toward CD44-overexpressing tumors in vivo. These nanotherapeutics achieve effective tumor suppression, drastically improved survival rate and reduced side effects as compared to clinically used pegylated liposomal doxorubicin in MCF-7 human breast tumor-bearing nude mice. Unlike previously reported multifunctional nanomedicines, the present nanotherapeutics primarily based on natural endogenous materials are simple and straightforward to fabricate, which makes them potentially interesting for clinical translation.

Sun B ，Deng C ，Meng F ，Zhang J ，Zhong Z ... -  《-》

Hyaluronic acid-capped compact silica-supported mesoporous titania nanoparticles for ligand-directed delivery of doxorubicin.

Mesoporous titania nanoparticles (MTN), owing to their high surface area to volume ratio and tunable pore sizes, appear capable of delivering sizable amounts of drug payloads, and hence, show considerable promise as drug delivery candidates in cancer therapy. We designed silica-supported MTN (MTNst) coated with hyaluronic acid (HA) to effectively deliver doxorubicin (DOX) for breast cancer therapy. The HA coating served a dual purpose of stabilizing the payload in the carriers as well as actively targeting the nanodevices to CD44 receptors. The so-formed HA-coated MTNst carrying DOX (HA/DOX-MTNst) had spheroid particles with a considerable drug-loading capacity and showed significantly superior in vitro cytotoxicity against MDA-MB-231 cells as compared to free DOX. HA/DOX-MTNst markedly improved the cellular uptake of DOX in an apparently CD44 receptor-dependent manner, and increased the number of apoptotic cells as compared to free DOX. These nanoplatforms accumulated in large quantities in the tumors of MDA-MB-231 xenograft tumor-bearing mice, where they significantly enhanced the inhibition of tumor growth compared to that observed with free DOX with no signs of acute toxicity. Based on these excellent results, we deduced that HA/DOX-MTNst could be successfully used for targeted breast cancer therapy. STATEMENT OF SIGNIFICANCE: This is the first study to use silica-supported mesoporous titania nanoparticles (MTNst) for doxorubicin (DOX) delivery to treat breast cancer, which exhibited effective and enhanced in vitro and in vivo apoptosis and tumor growth inhibition. Solid silica was used to support the mesoporous TiO2 resulting in MTNst, which efficiently incorporated a high DOX payload. The hyaluronic acid (HA) coating over the MTNst surface served a dual purpose of first, stabilizing DOX inside the MTNst (capping agent), and second, directing the nanoplatform device to CD44 receptors that are highly expressed in MDA-MB-231 cells (targeting ligand). The NPs exhibited highly efficacious in vitro tumor-cell killing and excellent in vivo tumor regression, highlighting the enormous promise of this system for breast cancer therapy.

Gupta B ，Poudel BK ，Ruttala HB ，Regmi S ，Pathak S ，Gautam M ，Jin SG ，Jeong JH ，Choi HG ，Ku SK ，Yong CS ，Kim JO ... -  《-》

Janus nanocarrier-based co-delivery of doxorubicin and berberine weakens chemotherapy-exacerbated hepatocellular carcinoma recurrence.

Despite the rapid progress which has been made in hepatocellular carcinoma (HCC) chemotherapeutics, recurrence of liver cancer still remains a barrier to achieve satisfying prognosis. Herein, we aimed to decipher the role of berberine (BER) in chemotherapy-exacerbated HCC repopulation via developing a nanocarrier co-deliveries doxorubicin (DOX) and BER to achieve a synergic effect in HCC treatment. The underlying fact of chemotherapy that promotes HCC repopulation was firstly examined and corroborated by clinical samples and murine repopulation model. Then, hyaluronic acid (HA)-conjugated Janus nanocarrier (HA-MSN@DB) was developed to load DOX and BER simultaneously. The HCC targeting efficiency, pH-controlled drug-release and anti-cancer property of HA-MSN@DB were assessed in CD44-overexpressed HCCs and normal liver cells. Magnet resonance imaging, bio-distribution, biocompatibility, tumor and recurrence inhibition studies were performed in H22 tumor-bearing mice. BER significantly reduced doxorubicin (DOX)-triggered HCC repopulation in vitro and in vivo through inhibiting Caspase-3-iPLA2-COX-2 pathway. The delivery of HA-MSN@DB into HCCs through CD44 receptor-mediated targeting effect was demonstrated. The controlled release of DOX and BER in response to acidic tumor microenvironment was validated. Importantly, HA-MSN@DB drastically enhanced the antitumor activity of DOX and suppressed DOX-exacerbated HCC repopulation in vitro and in vivo. Furthermore, HA-MSN@DB exhibited enhanced tumor accumulation and biocompatibility. Our findings revealed the pivotal role of BER in overcoming chemotherapy-exacerbated HCC repopulation through Caspase-3-iPLA2-COX-2 pathway, thereby providing a promising and stable nanocarrier integrating DOX and BER for effective HCC chemotherapy without repopulation. STATEMENT OF SIGNIFICANCE: In this work, we have first demonstrated the fact that berberine (Ber) reduces chemotherapy-exacerbated HCC recurrence and studied its mechanism by the aid of a doxorubicin-induced mice HCC relapse model. We then developed a promising strategy that simultaneously inhibits HCC and its recurrence with an HCC-targeted co-delivery nanocarrier HA-MSN@DB and revealed that such an inhibition was related with the suppression of Caspase-3-iPLA2-COX-2 pathway by berberine.

Zhang F ，Jia Y ，Zheng X ，Shao D ，Zhao Y ，Wang Z ，Dawulieti J ，Liu W ，Sun M ，Sun W ，Pan Y ，Cui L ，Wang Y ，He K ，Zhang M ，Li J ，Dong WF ，Chen L ... -  《-》