Elastase-targeting biomimic nanoplatform for neurovascular remodeling by inhibiting NETosis mediated AlM2 inflammasome activation in ischemic stroke.

Neutrophil elastase (NE) is a protease released by activated neutrophils in the brain parenchyma after cerebral ischemia, which plays a pivotal role in the regulation of neutrophil extracellular traps (NETs) formation. The excess NETs could lead to blood-brain barrier (BBB) breakdown, overwhelming neuroinflammation, and neuronal injury. While the potential of targeting neutrophils and inhibiting NE activity to mitigate ischemic stroke (IS) pathology has been recognized, effective strategies that inhibit NETs formation remain under-explored. Herein, a biomimic multifunctional nanoplatform (HM@ST/TeTeLipos) was developed for active NE targeting and IS treatment. The core of the HM@ST/TeTeLipos consisted of sivelestat-loaded ditelluride-containing liposomes with ROS-responsive and NE-inhibiting properties. The outer shell was composed of platelet-neutrophil hybrid membrane vesicles (HMVs), which acted to hijack neutrophils and neutralize proinflammatory cytokines. Our studies revealed that HM@ST/TeTeLipos could effectively inhibit NE activity, thereby suppressing the release of NETs, impeding the activation of the AIM2 inflammasome, and consequently redirecting the immune response away from a pro-inflammatory M1 microglia phenotype. This resulted in enhanced neurovascular remodeling, reduced BBB disruption, and diminished neuroinflammation, ultimately promoting neuron survival. We believe that this innovative approach holds significant potential for improving the treatment of IS and various NE-mediated inflammatory diseases.

Enhanced neuroprotective effects of resveratrol delivered by nanoparticles on hydrogen peroxide-induced oxidative stress in rat cortical cell culture.

Resveratrol (RES) has recently been reported as a potential antioxidant in treatment of ischemia/reperfusion injury through attenuating oxidative stress and apoptosis. However, application of RES is limited for its insolubility and short half-time. Latest evidence raises the possibility of developing nanoparticle-based delivery systems with improved solubility, stability and cytotoxicity of lipophilic drug. Here, we reported first a simple way to produce RES-loaded nanoparticles (RES-NPs) based on poly(N-vinylpyrrolidone)-b-poly(ε-caprolactone) polymer and further evaluated the protective effect of RES-NPs on hydrogen peroxide-induced oxidative stress and apoptosis in rat cortical cell culture. The controlled release pattern of RES-loaded nanoparticles was characterized by in vitro release experiments. Cytotoxicity tests proved cytocompatibility of these nanoparticles with neurons. Shown by coumarin-6 loaded nanoparticles, the uptake of nanoparticles by neurons was considered through endocytosis, which could lead to higher uptake efficiency at lower concentration. Thereby, the hypothesis is raised that RES-NPs could demonstrate enhanced neuroprotection compared to an equivalent dose of free RES at lower concentration, especially. It was further supported by enhanced reduction of LDH release, elimination of ROS and MDA, and attenuation of apoptosis signal (ratio of Bax/Bcl-2, activation of caspase-3). RES-NPs could be a potential treatment needing intensive research for ischemia/reperfusion related disorder including stroke.

Paclitaxel/tetrandrine coloaded nanoparticles effectively promote the apoptosis of gastric cancer cells based on "oxidation therapy".

Paclitaxel (Ptx) has demonstrated encouraging activity in the treatment of gastric cancer. Development of drug-containing biodegradable polymeric nanoparticles (np) becomes one of the solutions to relieve side effects of Ptx. However, Ptx-loaded nanoparticles prepared by the nanoprecipitation method are unstable in the aqueous phase. Here we report that tetrandrine (Tet) effectively increases the stability of Ptx-loaded nanoparticles when Tet is coencapsulated with Ptx into mPEG-PCL nanoparticles. The current study demonstrates the synergistic antitumor effect of Tet and Ptx against gastric cancer cells, which provides the basis of coadministration of Tet and Ptx by nanoparticles. It is reported that the cellular chemoresistance to Ptx correlates with intracellular antioxidant capacity and the depletion of cellular antioxidant capacity could enhance the cytotoxicity of Ptx. Tet effectively induces intracellular ROS production. Therefore, the present study provides a promising novel therapeutic strategy basing on "oxidation therapy" that it could amplify the antitumor effect of paclitaxel by employing Tet as a pro-oxidant. More intracellular Tet accumulation by endocytosis of Ptx/Tet-np than equivalent doses of free drug leads to more intracellular ROS induction, which could efficiently enhance the cytotoxicity of Ptx by sequential inhibition of ROS-dependent Akt pathway and activation of apoptotic pathways, all of which would mediate the superior cytotoxicity of Ptx/Tet-np over free drug. The present results suggest that the codelivery of Ptx and Tet by nanoparticles provides a novel therapeutic strategy basing on "oxidation therapy" against gastric cancer.

Curcumin delivery by methoxy polyethylene glycol-poly(caprolactone) nanoparticles inhibits the growth of C6 glioma cells.

As a potential anticancer agent, curcumin (Cum) has been reported for its chemopreventive and chemotherapeutic activity in a series of cancers through influencing cell cycle arrest, differentiation, apoptosis, etc. Therefore, the potential activity against various cancers of Cum raises the possibility of its application as a novel model drug in nanoparticle-based delivery systems. The current study reported a spherical core-shell structure curcumin-loaded nanoparticle (Cum-np) formed by amphilic methoxy polyethylene glycol-poly(caprolactone) (mPEG-PCL) block copolymers. Characterization tests indicated that Cum was incorporated into mPEG-PCL-based nanoparticles with high encapsulation efficiency due to its lipophilicity. The incorporated Cum could be released from Cum-np in a sustained manner. Cum was effectively transported into the cells by nanoparticles through endocytosis and localized around the nuclei in the cytoplasms. In vitro studies proved that the cytotoxicity of Cum-np would be pro-apoptosis effect against rat C6 glioma cell line in a dose-dependent manner. The present results suggest that Cum-np could be a potential useful chemotherapeutic formulation for malignant glioma therapy. Moreover, the development of traditional Chinese medicine with nanoscale drug formation warrants more intensive research for its clinical applications.

Synergistic anti-glioma effect of a coloaded nano-drug delivery system.

The anti-glioma effect of temozolomide (Tem) is sometimes undermined by the emerging resistance. Recently, resveratrol (Res), herbal medicine extracted from grape seeds, has been demonstrated for its potential use in chemosensitization. In the current study, both these drugs were loaded simultaneously into nanoparticles with methoxy poly(ethylene glycol)-poly epsilon caprolactone (mPEG-PCL) as drug carriers in order to achieve better antitumor efficiency. Tem/Res-coloaded mPEG-PCL nanoparticles were constructed, characterized, and tested for antitumor effect on glioma cells by using in vitro and xenograft model system. The nanoparticle constructs were satisfactory with drug loading content (Res =~12.4%; Tem =~9.3%) and encapsulation capacity of >85% for both the drugs. In addition, the coencapsulation led to better in vitro stability of the nanoparticles than Tem-loaded nanoparticles. An in vitro uptake study demonstrated a high uptake efficiency of the nanoparticles by glioma cells. The synergistic antitumor effect against glioma cells was observed in the combinational treatment of Res and Tem. Tem/Res-coloaded nanoparticles induced higher apoptosis in U87 glioma cells as compared to cells treated by the combination of free drugs. Tem/Res-coloaded particles caused more effective inhibition of phosphor-Akt, leading to upregulation of the downstream apoptotic proteins. In addition, the in vivo study showed the superior tumor delaying effect of coloaded nanoparticles than that of free drug combination. These results suggest that Tem/Res-coloaded nanoparticles could be a potential useful chemotherapeutic formulation for glioma therapy.

Enhanced Pro-Apoptotic Effect of Tetrandrine Loaded Nanoparticles Against Osteosarcoma Cells.

BACKGROUND: Tetrandrine (Tet), a kind of herbal medicine belonging to the family of bis-benzylisoquinoline alkaloid, has gained more attraction for its potential anti-tumor effects. However, its potential utilization in clinic is greatly hampered by the poor pharmacokinetcs profile due to its insolubility. Recently, biodegradable polymeric nanoparticles with amphilic copolymers as drug carriers have shown better bioavailability against tumor as promising tumor-targeted drug delivery system. METHODS: In the current study, Tet-loaded nanoparticles (Tet-NPs) was prepared with amphiphilic block copolymer as drug carriers. The physiochemical characterization, in vitro and in vivo antitumor effect of nanoparticles were evaluated. RESULTS: In vitro study demonstrated the superior cell inhibitory effect of Tet-NPs. Most importantly, the viability of cells exposed to Tet-NPs was significant lower than that of cells treated with free Tet at lower equivalent doses. Moreover, Tet- NPs induced apoptosis and inhibited the proliferation of cells more effectively than free did at the equivalent concentration. Western blot showed that the expression of anti-apoptotic protein Bcl-2, Bcl-XL was significantly promoted while the pro-apoptotic Bax was significantly inhibited by the treatment of Tet-NPs. CONCLUSION: Data from the current study suggested that Tet-NPs is a promising delivery nano-system for the treatment of osteosarcoma.

Characterization of the Uptake Efficiency and Cytotoxicity of Tetrandrine-Loaded Poly(N-vinylpyrrolidone)-Block-Poly(ε-caprolactone) (PVP-b-PCL) Nanoparticles in the A549 Lung Adenocarcinoma Cell Line.

Tetrandrine (Tet) has been previously reported to induce apoptosis in several cancer cell lines. However, poor Tet solubility has limited its further application. The lipophilicity of Tet suggests that the development of Tet-loaded biodegradable polymeric micelle delivery systems may be possible. In our previous work, we demonstrated the superior antitumor efficiency of Tet-loaded mPEG-PCL nanoparticles (NPs) in colorectal cancer cell lines. In the present study, we report that a spherical core­shell Tet-loaded nanoparticle structure was prepared using a nanoprecipitation method by employing amphiphilic poly(N-vinylpyrrolidone)-block-poly(ε-caprolactone) (PVP-b-PCL) copolymers as drug carriers. Tet was incorporated into the NPs with high encapsulation efficiency and released in a sustained release pattern. Moreover, coumarin-6 (hydrophobic fluorescence)-loaded Tet-NP uptake was shown to be mediated mainly by endocytosis from the NPs and was more efficient than that of rhodamine B (hydrophilic fluorescence)-loaded NP uptake, which was mainly dependent upon infiltration. The endocytic uptake process was blocked by NaN3, a mitochondrial inhibitor. In vitro studies using the A549 cell line demonstrated the superior cytotoxicity and apoptosis induction ability of Tet-NPs in dose- and time-dependent manners compared to free Tet. The data obtained from this study, therefore, not only confirm the potential use of Tet to treat lung cancer but also suggest an effective manner by which to improve the anticancer efficiency of Tet in nano-drug delivery systems.

Efficient delivery of ursolic acid by poly(N-vinylpyrrolidone)-block-poly (ε-caprolactone) nanoparticles for inhibiting the growth of hepatocellular carcinoma in vitro and in vivo.

Previous reports have shown that ursolic acid (UA), a pentacyclic triterpenoid derived from Catharanthus trichophyllus roots, could inhibit the growth of a series of cancer cells. However, the potential for clinical application of UA is greatly hampered by its poor solubility, whereas the hydrophobicity of UA renders it a promising model drug for nanosized delivery systems. In the current study, we loaded UA into amphiphilic poly(N-vinylpyrrolidone)-block-poly (ε-caprolactone) nanoparticles and performed physiochemical characterization as well as analysis of the releasing capacity. In vitro experiments indicated that UA-NPs inhibited the growth of liver cancer cells and induced cellular apoptosis more efficiently than did free UA. Moreover, UA-NPs significantly delayed tumor growth and localized to the tumor site when compared with the equivalent dose of UA. In addition, both Western blotting and immunohistochemistry suggested that the possible mechanism of the superior efficiency of UA-NPs is mediation by the regulation of apoptosis-related proteins. Therefore, UA-NPs show potential as a promising nanosized drug system for liver cancer therapy.

An efficient Trojan delivery of tetrandrine by poly(N-vinylpyrrolidone)-block-poly(ε-caprolactone) (PVP-b-PCL) nanoparticles shows enhanced apoptotic induction of lung cancer cells and inhibition of its migration and invasion.

Earlier studies have demonstrated the promising antitumor effect of tetrandrine (Tet) against a series of cancers. However, the poor solubility of Tet limits its application, while its hydrophobicity makes Tet a potential model drug for nanodelivery systems. We report on a simple way of preparing drug-loaded nanoparticles formed by amphiphilic poly(N-vinylpyrrolidone)-block-poly(ε-caprolactone) (PVP-b-PCL) copolymers with Tet as a model drug. The mean diameters of Tet-loaded PVP-b-PCL nanoparticles (Tet-NPs) were between 110 nm and 125 nm with a negative zeta potential slightly below 0 mV. Tet was incorporated into PVP-b-PCL nanoparticles with high loading efficiency. Different feeding ratios showed different influences on sizes, zeta potentials, and the drug loading efficiencies of Tet-NPs. An in vitro release study shows the sustained release pattern of Tet-NPs. It is shown that the uptake of Tet-NPs is mainly mediated by the endocytosis of nanoparticles, which is more efficient than the filtration of free Tet. Further experiments including fluorescence activated cell sorting and Western blotting indicated that this Trojan strategy of delivering Tet in PVP-b-PCL nanoparticles via endocytosis leads to enhanced induction of apoptosis in the non-small cell lung cancer cell A549 line; enhanced apoptosis is achieved by inhibiting the expression of anti-apoptotic Bcl-2 and Bcl-xL proteins. Moreover, Tet-NPs more efficiently inhibit the ability of cell migration and invasion than free Tet by down-regulating matrix metalloproteinases (MMP)-2 and MMP-9, as well as up-regulating tissue inhibitor of MMP-3 (TIMP-3). Therefore, data from this study not only confirms the potential of Tet in treating lung cancer but also offers an effective way of improving the anticancer efficiency of Tet by nanodrug delivery systems.

Resveratrol-loaded nanoparticles reduce oxidative stress induced by radiation or amyloid-beta in transgenic Caenorhabditis elegans.

Resveratrol (trans-3,4',5-trihydroxystilbene, RES) is a naturally occurring lipophilic antioxidant that has been intensively studied for its promising efficacy in treating oxidative stress-associated disorders. Despite the array of bioactivities that it possesses, RES has low bioavailability due to its poor aqueous solubility and dissolution properties. Recent nanotechnology has led to the effective development of drug delivery systems. In this study, RES-loaded nanoparticles (RES-NPs) were prepared based on amphiphilic methoxy-polyethyleneglycol-poly-caprolactone (mPEG-PCL) block copolymers, which improve the physical properties of resveratrol in aqueous solution. The antioxidative capacity of RES-NPs was then evaluated sequentially in vitro and in vivo. RES-NPs exhibited stronger radical scavenging and anti-lipid peroxidization compared to that of raw RES in aqueous solution. The pre-treatment of irradiated Caenorhabditis elegans (C. elegans) with RES-NPs extended both the maximum and mean life span. Furthermore, the RES-NPs were capable of alleviating injury from gamma-ray radiation and amyloid-beta peptide overexpression toxicity in C. elegans through radical scavenging and over-regulation of SOD-3 expression. The enhancement of in vitro antioxidation properties in aqueous solution and protection against oxidative stress in C. elegans induced by both gamma-ray radiation and amyloid-beta peptide confirmed the successful development of antioxidant nanoparticles.

Delivery of ursolic acid (UA) in polymeric nanoparticles effectively promotes the apoptosis of gastric cancer cells through enhanced inhibition of cyclooxygenase 2 (COX-2).

It has been demonstrated that ursolic acid (UA) could effectively induces apoptosis of cancer cells by inhibiting the expression of cyclooxygenase 2 (COX-2), which constitutively expresses in gastric cancer. However, the hydrophobicity of UA increases the difficulty in its potential clinical application, which raises the possibility for its application as a novel model drug in nanoparticle-based delivery system. UA-loaded nanoparticles (UA-NPs) were prepared by a nano-precipitation method using amphilic methoxy poly(ethylene glycol)-polycaprolactone (mPEG-PCL) block copolymers as drug carriers. UA was effectively transported into SGC7901 cells by nanoparticles and localized around the nuclei in the cytoplasms. The in vitro cytotoxicity and apoptosis test indicated that UA-NPs significantly elicited more cell death at almost equivalent dose and corresponding incubation time. Moreover, UA-NPs led to more cell apoptosis through stronger inhibition of COX-2 and activation of caspase 3. The most powerful evidence from this report is that the significant differences between the cytotoxicity of free UA and UA-NPs are closely related to the expression levels of COX-2 and caspase-3, which demonstrates the superiority of UA-NPs over free UA through penetrating cell membrane. Therefore, the study offer an effective way to improve the anticancer efficiency of UA through nano-drug delivery system.

Resveratrol-loaded polymeric micelles protect cells from Abeta-induced oxidative stress.

Resveratrol has been reported to protect several types of cells against beta-amyloid peptide (Abeta) toxicity by scavenging reactive oxygen species (ROS) and inactivating caspase-3. However, other studies found that long-term treatment with resveratrol inhibited cells by inducing ROS generation and activating caspase-3. In the current report, a 48-h incubation of resveratrol at the concentrations of 5 and 10 microM significantly attenuated the viability of PC12 cells and a 12-h pre-incubation of resveratrol did not protect PC12 cells against Abeta exposure (even further inhibited PC12 cells at the concentrations of 10 microM) by acting as a pro-oxidant. Due to the lipophilicity of resveratrol, resveratrol-loaded polymeric micelles basing on amphiphilic block copolymer were developed. Then, the effects of resveratrol-loaded polymeric micelles on the viability and Abeta protection of PC12 cells were investigated. At the equivalent concentrations of 5 and 10 microM resveratrol, a 48-h incubation of resveratrol-loaded nanoparticles did not show toxicity to cells, while 12-h pre-incubation of resveratrol-loaded nanoparticles protected PC12 cells from Abeta-induced damage in a dose dependent manner (1-10 microM) by attenuating intracellular oxidative stress and caspase-3 activity. Further investigations are absolutely needed to evaluate the feasibility and advantages of in vivo applications of resveratrol-loaded nanoparticles.