Chitosan-Based Polyelectrolyte Complexes as Potential Nanoparticulate Carriers: Physicochemical and Biological Characterization

Purpose

To investigate the effect of polyelectrolytes on the formation and physicochemical properties of chitosan nanoparticles (CS-NPs) used for the delivery of an anticancer drug, doxorubicin (DOX).

Method

Three DOX-loaded CS-NPs were formulated with tripolyphosphate (CS-TP/DOX NPs), dextran sulfate (CS-DS/DOX NPs), and hyaluronic acid (CS-HA/DOX NPs) by using ionotropic gelation or complex coacervation.

Results

CS-TP/DOX NPs were the smallest, with an average size of ~100 nm and a narrow size distribution, while CS-DS/DOX and CS-HA/DOX NPs were ~200 nm in size. Transmission electron microscopy clearly showed a spherical shape for all the NPs. The strong binding affinity of DOX for the multiple sulfate groups in DS resulted in a sustained release profile from CS-DS/DOX NPs at pH 7.4, while CS-HA/DOX NPs exhibited faster DOX release. This trend was also present under acidic conditions, where release of DOX was significantly augmented because of polymer protonation. Compared to CS-TP/DOX or CS-DS/DOX NPs, CS-HA/DOX NPs showed superior cellular uptake and cytotoxicity in MCF-7 and A-549 cells, because of their ability to undergo CD44-mediated endocytosis. Pharmacokinetic studies clearly showed that all CS-NPs tested significantly improved DOX plasma circulation time and decreased its elimination rate constant. Consistent with the in vitro release data, CS-DS/DOX NPs exhibited a relatively better DOX plasma profile and enhanced blood circulation, compared to CS-HA/DOX or CS-TP/DOX NPs. Overall, these results demonstrated how NP design can influence their function.

Conclusions

Taken together, CS-based polyelectrolyte complexes could provide a versatile delivery system with enormous potential in the pharmaceutical and biomedical sectors.     

Multifunctional self-delivery micelles targeting the invasion-metastasis cascade for enhanced chemotherapy against melanoma and the lung metastasis

Metastasis is closely related to the high mortality of cancer patients, which is regulated by multiple signaling pathways. Hence, multiphase blocking of this biological process is beneficial for cancer treatments. Herein, we establish a multifunctional self-delivering system by synthesizing D-α-tocopheryl succinates (TOS)-conjugated chondroitin sulfate (CS) (CT NPs), which both serve as nanocarrier and antimetastatic agent that affects different phases of the metastatic cascade. TOS as the hydrophobic segment of CT NPs can inhibit the secretion of matrix metalloproteinase-9, while the hydrophilic segment CS targets B16F10 cells through CD44 receptors and reduces the interaction between tumor cells and platelets. The results show that CT NPs are able to inhibit metastasis successfully both in vitro and in vivo by interfering the multiphase of the metastatic cascade. Following encapsulating chemotherapeutic drug doxorubicin (DOX), the obtained micelles CT/DOX efficiently suppress both primary-tumor growth and metastases in B16F10 bearing mice. As a result, the rationally designed multifunctional NPs composing of biocompatible materials provide excellent therapeutic effects on solid tumors and metastases.     

Evaluation of doxorubicin-loaded pH-sensitive polymeric micelle release from tumor blood vessels and anticancer efficacy using a dorsal skin-fold window chamber model

Aim： To evaluation the doxorubicin （DOX）-loaded pH-sensitive polymeric micelle release from tumor blood vessels into tumor interstitium using an animal vessel visibility model, the so-called dorsal skin-fold window chamber model.
Methods： DOX-loaded pH-sensitive polyHis-b-PEG micelles and DOX-loaded pH-insensitive PLLA-b-PEG micelles were prepared. The uptake of the micelles by MDA-MB-231 breast cancer cells in vitro and in vivo was examined using flow cytometry. The pharmacokinetic parameters of the micelles were determined in SD rats after intravenous injection of a DOX dose （6 mg/kg）. The release of the micelles from tumor vasculature and the antitumor efficacy were evaluated in MDA-MB-231 breast cancer xenografted in nude mice using a dorsal skin-fold window chamber.
Results： The effective elimination half-life t1/2 of the pH-sensitive, pH-insensitive polymeric micelles and DOX-PBS in rats were 11.3 h, 9.4 h, and 2.1 h, respectively. Intravital microscopy in MDA-MB-231 breast cancer xenografted in nude mice showed that the pH-sensitive polymeric micelles rapidly extravasated from the tumor blood vessels, and DOX carried by the pH-sensitive micelles was preferentially released at the tumor site as compared to the pH-insensitive polymeric micelles. Furthermore, the pH-sensitive polymeric micelles exhibited significant greater efficacy in inhibition of tumor growth in the nude mice.
Conclusion： When DOX is loaded into pH-sensitive polymeric micelles, the acidity in tumor interstitium causes the destabilization of the micelles and triggers drug release, resulting in high local concentrations within the tumor, thus more effectively inhibiting the tumor growth in vivo.     

槐耳颗粒联合DC-CIK细胞对乳腺癌MDA-MB-231干细胞体内外杀伤作用研究

目的 探究白屈菜红碱（CHE）对腺样囊性癌细胞（ACC2）生长的抑制作用及机制。方法 利用CCK8法、EdU法、Hoechst33342/PI双染色法、试剂盒法检测CHE对ACC2细胞活力、细胞增殖、细胞凋亡和活性氧（ROS）水平的影响;通过Western blotting技术检测CHE对Cleaved-Caspase 3、PARP、NF-κB、p-JNK、p-p38蛋白表达的影响;利用斑马鱼移植瘤模型检测CHE对斑马鱼体内ACC2细胞生长的抑制作用。结果 CCK-8结果显示：与对照组比较,2、3、4、5、6、7、8、9、10 μmol/L的CHE显著降低ACC2细胞的存活率（P<0.05、0.01）,且呈浓度相关性; ROS检测结果显示：与对照组比较,5、8 μmol/L的CHE导致ACC2细胞内的ROS水平显著上升（P<0.05、0.01）; EdU增殖检测结果表明：与对照组比较,5、8 μmol/L的CHE致使ACC2细胞的增殖能力显著下降（P<0.01）;Hoechst/PI染色结果显示：与对照组比较,CHE 5、8 μmol/L组ACC2细胞凋亡率显著上升（P<0.01）。抗氧化剂N-乙酰半胱氨酸（NAC）显著抑制CHE诱导的ROS水平升高、细胞凋亡增加（P<0.01）;Western blotting结果显示：2、5、8 μmol/L的CHE能够显著上调Cleaved-Caspase 3、PARP、NF-κB蛋白的表达（P<0.01）,且呈现浓度相关性,5、8 μmol/L的CHE能够显著上调p-JNK的蛋白表达（P<0.01）,8 μmol/L的CHE能够显著上调p-p38的蛋白表达（P<0.01）;NAC显著降低由CHE导致的Cleaved-Caspase 3、PARP、NF-κB、p-JNK、p-p38蛋白表达增加（P<0.01）,5、8 μmol/L CHE能够有效抑制斑马鱼体内肿瘤的生长（P<0.01）。结论 体外及斑马鱼移植瘤模型证明,CHE可以有效抑制ACC2细胞生长,其机制与提高细胞ROS水平,上调NF-κB、p-JNK、p-p38表达,从而抑制细胞增殖、诱导细胞凋亡相关。     

Docetaxel-loaded PLGA nanoparticles to increase pharmacological sensitivity in MDA-MB-231 and MCF-7 breast cancer cells

This study aimed to develop docetaxel (DTX) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (DTX-NPs) and to evaluate the different pharmacological sensitivity of NPs to MCF-7 and MDA-MB-231 breast cancer cells. NPs containing DTX or coumarin-6 were prepared by the nanoprecipitation method using PLGA as a polymer and d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) as a surfactant. The physicochemical properties of NPs were characterized. In vitro anticancer effect and cellular uptake were evaluated in breast cancer cells. The particle size and zeta potential of the DTX-NPs were 160.5 ± 3.0 nm and –26.7 ± 0.46 mV, respectively. The encapsulation efficiency and drug loading were 81.3 ± 1.85% and 10.6 ± 0.24%, respectively. The in vitro release of DTX from the DTX-NPs was sustained at pH 7.4 containing 0.5% Tween 80. The viability of MDA-MB-231 and MCF-7 cells with DTX-NPs was 37.5 ± 0.5% and 30.3 ± 1.13%, respectively. The IC₅₀ values of DTX-NPs were 3.92- and 6.75-fold lower than that of DTX for MDA-MB-231 cells and MCF-7 cells, respectively. The cellular uptake of coumarin-6-loaded PLGA-NPs in MCF-7 cells was significantly higher than that in MDA-MB-231 cells. The pharmacological sensitivity in breast cancer cells was higher on MCF-7 cells than on MDA-MB-231 cells. In conclusion, we successfully developed DTX-NPs that showed a great potential for the controlled release of DTX. DTX-NPs are an effective formulation for improving anticancer effect in breast cancer cells.     

The synergistic antitumor activity of 3-(2-nitrophenyl) propionic acid-paclitaxel nanoparticles (NPPA-PTX NPs) and anti-PD-L1 antibody inducing immunogenic cell death

Cancer immunotherapy is a strategy that is moving to the frontier of cancer treatment in the current decade. In this study, we show evidence that 3-(2-nitrophenyl) propionic acid-paclitaxel nanoparticles (NPPA-PTX NPs), act as immunogenic cell death (ICD) inducers, stimulating an antitumor response which results in synergistic antitumor activity by combining anti-PD-L1 antibody (aPD-L1) in vivo. To investigate the antitumor immunity induced by NPPA-PTX NPs, the expression of both ICD marker calreticulin (CRT) and high mobility group box 1 (HMGB1) were analyzed. In addition, the antitumor activity of NPPA-PTX NPs combined with aPD-L1 in vivo was also investigated. The immune response was also measured through quantitation of the infiltration of T cells and the secretion of pro-inflammatory cytokines. The results demonstrate that NPPA-PTX NPs induce ICD of MDA-MB-231 and 4T1 cells through upregulation of CRT and HMGB1, reactivating the antitumor immunity via recruitment of infiltrating CD3+, CD4+, CD8+ T cells, secreting IFN-γ, TNF-α, and the enhanced antitumor activity by combining with aPD-L1. These data suggest that the combined therapy has a synergistic antitumor activity and has the potential to be developed into a novel therapeutic regimen for cancer patients.     

Spatiotemporally Controlled Co-delivery of Anti-vasculature Agent and Cytotoxic Drug by Octreotide-Modified Stealth Liposomes

Purpose

Both combretastatin A-4 (CA-4) and doxorubicin (DOX) was loaded in different form in a targeted nanomedicine in order to achieve the active delivery of these two drugs followed by sequentially suppressing tumor vasculature and tumor cells.

Methods

Octreotide-modified stealth liposomes loaded with CA-4 and DOX (Oct-L[CD]) were prepared and characterized. Then in vitro release, cellular uptake, in vitro antitumor effect, pharmacokinetics, in vivo sequential killing effect, in vivo antitumor efficacy against somatostatin receptor (SSTR) positive cells, as well as the action mechanism of such system, were studied.

Results

A rapid release of CA-4 followed by a slow release of DOX was observed in vitro. The active targeted liposomes Oct-L[CD] showed a specific cellular uptake through ligand-receptor interaction and a higher antitumor effect in vitro against SSTR-positive cell line. The in vivo sequential killing effect of such system was found as evidenced by the fast inhibition of blood vessels and slow apoptosis-inducing of tumor cells. Oct-L[CD] also exhibited the strongest antitumor effect in MCF-7 subcutaneous xenograft models.

Conclusions

Oct-modified co-delivery system may have great potential as an effective carrier for cancer therapy.     

Immunoliposomal delivery of doxorubicin can overcome multidrug resistance mechanisms in EGFR-overexpressing tumor cells

Immunoliposomes (ILs) can be constructed to target the epidermal growth factor receptor (EGFR) to provide efficient intracellular drug delivery in tumor cells. We hypothesized that this approach might be able to overcome drug resistance mechanisms, which remain an important obstacle to better outcomes in cancer therapy. ILs were evaluated in vitro and in vivo against EGFR-overexpressing pairs of human cancer cells (HT-29 and MDA-MB-231) that either lack or feature the multidrug resistance (mdr) phenotype. In multidrug-resistant cell lines, ILs loaded with doxorubicin (DOX) produced 19–216-fold greater cytotoxicity than free DOX, whereas in nonresistant cells, immunoliposomal cytotoxicity of DOX was comparable with that of the free drug. In intracellular distribution studies, free DOX was efficiently pumped out of the multidrug-resistant tumor cells, whereas immunoliposomal DOX leads to 3.5–8 times higher accumulation of DOX in the cytoplasm and 3.5–4.9 times in the nuclei compared with the free drug. Finally, in vivo studies in the MDA-MB-231 Vb100 xenograft model confirmed the ability of anti-EGFR ILs-DOX to efficiently target multidrug-resistant cells and showed impressive antitumor effects, clearly superior to all other treatments. In conclusion, ILs provide efficient and targeted drug delivery to EGFR-overexpressing tumor cells and are capable of completely reversing the multidrug-resistant phenotype of human cancer cells.     

Folate-decorated poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) nanoparticles for targeting delivery: optimization and in vivo antitumor activity

Abstract

Context: Doxorubicin (DOX)-loaded folate-targeted poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) [P(HB-HO)] nanoparticles [DOX/FA-PEG-P(HB-HO) NPs] have potential application in clinical treatments for cervical cancer due to specific affinity of folate and folate receptor in HeLa cells.

Objective: The aim of this study was to develop an optimized formulation for DOX/FA-PEG-P(HB-HO) NPs, and investigate the targeting and efficacies of the nanoparticles.

Materials and methods: DOX/FA-PEG-P(HB-HO) NPs were prepared by W₁/O/W₂ solvent extraction/evaporation method, and an orthogonal experimental design [L₉ (3⁴)] was applied to establish the optimum conditions. The physico–chemical characteristics, microscopic observation and in vivo antitumor study of the nanoparticles were evaluated.

Results: The optimum formulation was obtained with DOX 10% (w/v), FA-PEG-P(HB-HO) 6.5% (w/v), PVA 3%(w/v) and oil phase/internal water phase volume ratio of 3/1. The size distribution, drug loading and encapsulation efficiency of the optimized nanoparticles were 150–350?nm, 29.6?±?2.9% and 83.5?±?5.7%, respectively. In vitro release study demonstrated that 80% of the drug could release from the nanoparticles within 11 days. Furthermore, in vitro microscopic observation and in vivo antitumor study showed that DOX/FA-PEG-P(HB-HO) NPs could inhibit HeLa cells effectively, and the tumor inhibition rate (TIR) in vivo was 76.91%.

Discussion and conclusions: DOX/FA-PEG-P(HB-HO) NPs have been successfully developed and optimized. In vitro drug release study suggested a sustained release profile. Moreover, DOX/FA-PEG-P(HB-HO) NPs could effectively inhibit HeLa cells with satisfying targeting, and reduce side effects and toxicity to normal tissues. DOX/FA-PEG-P(HB-HO) NPs were superior in terms of inhibiting HeLa tumor over non-targeted formulations therapy.     

Self-assembled nanoparticles of reduction-sensitive poly (lactic-co-glycolic acid)-conjugated chondroitin sulfate A for doxorubicin delivery: preparation,characterization and evaluation

In this study, reduction-sensitive self-assembled polymer nanoparticles based on poly (lactic-co-glycolic acid) (PLGA) and chondroitin sulfate A (CSA) were developed and characterized. PLGA was conjugated with CSA via a disulfide linkage (PLGA-ss-CSA). The critical micelle concentration (CMC) of PLGA-ss-CSA conjugate is 3.5?µg/mL. The anticancer drug doxorubicin (DOX) was chosen as a model drug, and was effectively encapsulated into the nanoparticles (PLGA-ss-CSA/DOX) with high loading efficiency of 15.1%. The cumulative release of DOX from reduction-sensitive nanoparticles was only 34.8% over 96?h in phosphate buffered saline (PBS, pH 7.4). However, in the presence of 20?mM glutathione-containing PBS environment, DOX release was notably accelerated and almost complete from the reduction-sensitive nanoparticles up to 96?h. Moreover, efficient intracellular DOX release of PLGA-ss-CSA/DOX nanoparticles was confirmed by CLSM assay in A549 cells. In vitro cytotoxicity study showed that the half inhibitory concentrations of PLGA-ss-CSA/DOX nanoparticles and free DOX against A549 cells were 1.141 and 1.825?µg/mL, respectively. Therefore, PLGA-ss-CSA/DOX nanoparticles enhanced the cytotoxicity of DOX in vitro. These results suggested that PLGA-ss-CSA nanoparticles could be a promising carrier for drug delivery.     

Folate-mediated poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) nanoparticles for targeting drug delivery

A novel targeting drug delivery system (TDDS) has been developed. Such a TDDS was prepared by W₁/O/W₂ solvent extraction/evaporation method, adopting poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) [P(HB-HO)] as the drug carrier, folic acid (FA) as the targeting ligand, and doxorubicin (DOX) as the model anticancer drug. The average size, drug loading capacity and encapsulation efficiency of the prepared DOX-loaded, folate-mediated P(HB-HO) nanoparticles (DOX/FA–PEG–P(HB-HO) NPs) were found to be around 240 nm, 29.6% and 83.5%. The in vitro release profile displayed that nearly 50% DOX was released in the first 5 days. The intracellular uptake tests of the nanoparticles (NPs) in vitro showed that the DOX/FA–PEG–P(HB-HO) NPs were more efficiently taken up by HeLa cells compared to non-folate-mediated P(HB-HO) NPs. In addition, DOX/FA–PEG–P(HB-HO) NPs (IC₅₀ = 0.87 μM) showed greater cytotoxicity to HeLa cells than other treated groups. In vivo anti-tumor activity of the DOX/FA–PEG–P(HB-HO) NPs showed a much better therapeutic efficacy in inhibiting tumor growth, and the final mean tumor volume was 178.91 ± 17.43 mm³, significantly smaller than normal saline control group (542.58 ± 45.19 mm³). All these results have illustrated that our techniques for the preparing of DOX/FA–PEG–P(HB-HO) NPs developed in present work are feasible and these NPs are effective in selective delivery of anticancer drug to the folate receptor-overexpressed cancer cells. The new TDDS may be a competent candidate in application in targeting treatment of cancers.     

Magnetically triggered drug release from nanoparticles and its applications in anti-tumor treatment

The objective of this study was to describe the magnetic nanoparticle–drug conjugates for improved control of drug delivery and drug release. The widely used anticancer agent Doxorubicin (DOX) was successfully conjugated via amine groups to the carboxylic functional groups coating magnetic nanoparticles (fluidMAG-CMX). Following purification of the nanoparticles, the conjugation of DOX on fluidMAG-CMX was confirmed using FTIR spectroscopy and confocal microscopy. The observed drug loading capacity of DOX was 22.3%. Studies of magnetically triggered release were performed under an oscillating magnetic field (OMF). DOX exhibited a significant release percentage of 70% under an OMF, as compared with the release in enzyme. A magnetic field turn-on and turn-off experiment was also conducted to confirm the control of drug release using this triggered system. In vivo experiments indicated that the tumor-inhibitory rate of CMX–DOX NPs under a magnetic field was higher than the other control groups. According to the toxicity assessments, CMX–DOX NPs were not noticeably toxic to mice at our tested dose.     

Engineering a folic acid-decorated ultrasmall gemcitabine nanocarrier for breast cancer therapy: Dual targeting of tumor cells and tumor-associated macrophages

Combination of passive targeting with active targeting is a promising approach to improve the therapeutic efficacy of nanotherapy. However, most reported polymeric systems have sizes above 100 nm, which limits effective extravasation into tumors that are poorly vascularized and have dense stroma. This will, in turn, limit the overall effectiveness of the subsequent uptake by tumor cells via active targeting. In this study, we combined the passive targeting via ultra-small-sized gemcitabine (GEM)-based nanoparticles (NPs) with the active targeting provided by folic acid (FA) conjugation for enhanced dual targeted delivery to tumor cells and tumor-associated macrophages (TAMs). We developed an FA-modified prodrug carrier based on GEM (PGEM) to load doxorubicin (DOX), for co-delivery of GEM and DOX to tumors. The co-delivery system showed small particle size of ～10 nm in diameter. The ligand-free and FA-targeted micelles showed comparable drug loading efficiency and a sustained DOX release profile. The FA-conjugated micelles effectively increased DOX uptake in cultured KB cancer cells that express a high level of folate receptor (FR), but no obvious increase was observed in 4T1.2 breast cancer cells that have a low-level expression of FR. Interestingly, in vivo, systemic delivery of FA-PGEM/DOX led to enhanced accumulation of the NPs in tumor and drastic reduction of tumor growth in a murine 4T1.2 breast cancer model. Mechanistic study showed that 4T1.2 tumor grown in mice expressed a significantly higher level of FOLR2, which was selectively expressed on TAMs. Thus, targeting of TAM may also contribute to the improved in vivo targeted delivery and therapeutic efficacy.     

l-Peptide functionalized dual-responsive nanoparticles for controlled paclitaxel release and enhanced apoptosis in breast cancer cells

Nanoparticles and macromolecular carriers have been widely used to increase the efficacy of chemotherapeutics, largely through passive accumulation provided by their enhanced permeability and retention effect. However, the therapeutic efficacy of nanoscale anticancer drug delivery systems is severely truncated by their low tumor-targetability and inefficient drug release at the target site. Here, the design and development of novel l-peptide functionalized dual-responsive nanoparticles (l-CS-g-PNIPAM-PTX) for active targeting and effective treatment of GRP78-overexpressing human breast cancer in vitro and in vivo are reported. l-CS-g-PNIPAM-PTX NPs have a relative high drug loading (13.5%) and excellent encapsulation efficiency (74.3%) and an average diameter of 275?nm. The release of PTX is slow at pH 7.4 and 25?°C but greatly accelerated at pH 5.0 and 37?°C. MTT assays and confocal experiments showed that the l-CS-g-PNIPAM-PTX NPs possessed high targetability and antitumor activity toward GRP78 overexpressing MDA-MB-231 human breast cancer cells. As expected, l-CS-g-PNIPAM-PTX NPs could effectively treat mice bearing MDA-MB-231 human breast tumor xenografts with little side effects, resulting in complete inhibition of tumor growth and a high survival rate over an experimental period of 60 days. These results indicate that l-peptide-functionalized acid – and thermally activated – PTX prodrug NPs have a great potential for targeted chemotherapy in breast cancer.     

Folate-modified doxorubicin-loaded nanoparticles for tumor-targeted therapy

Context: Polymeric nanoparticles (NPs) have been used frequently as drug delivery vehicles. Surface modification of polymeric NPs with specific ligands defines a new biological identity, which assists in targeting of the nanocarriers to specific cancers cells.

Objective: The aim of this study is to develop a kind of modified vector which could target the cancer cells through receptor-mediated pathways to increase the uptake of doxorubicin (DOX).

Methods: Folate (FA)-conjugated PEG–PE (FA–PEG–PE) ligands were used to modify the polymeric NPs. The modification rate was optimized and the physical–chemical characteristics, in vitro release, and cytotoxicity of the vehicle were evaluated. The in vivo therapeutic effect of the vectors was evaluated in human nasopharyngeal carcinoma KB cells baring mice by giving each mouse 100?µl of 10?mg/kg different solutions.

Results: FA–PEG–PE-modified NPs/DOX (FA-NPs/DOX) have a particle size of 229?nm, and 86% of drug loading quantity. FA-NPs/DOX displayed remarkably higher cytotoxicity (812?mm³ tumor volume after 13?d of injection) than non-modified NPs/DOX (1290?mm³) and free DOX solution (1832?mm³) in vivo.

Conclusion: The results demonstrate that the modified drug delivery system (DDS) could function comprehensively to improve the efficacy of cancer therapy. Consequently, the system was shown to be a promising carrier for delivery of DOX, leading to the efficiency of antitumor therapy.     

Zinc-doped Prussian blue nanoparticles for mutp53-carrying tumor ion interference and photothermal therapy

Quite a great proportion of known tumor cells carry mutation in TP53 gene, expressing mutant p53 proteins (mutp53) missing not only original genome protective activities but also acquiring gain-of-functions that favor tumor progression and impede treatment of cancers. Zinc ions were reported as agents cytocidal to mutp53-carrying cells by recovering p53 normal functions and abrogating mutp53. Meanwhile in a hyperthermia scenario, the function of wild type p53 is required to ablate tumors upon heat treatment hence the effects might be hindered in a mutp53 background. We herein synthesized zinc-doped Prussian blue (ZP) nanoparticles (NPs) to combine Zn²⁺ based and photothermal therapeutic effects. An efficient release of Zn²⁺ in a glutathione-enriched tumor intracellular microenvironment and a prominent photothermal conversion manifested ZP NPs as zinc ion carriers and photothermal agents. Apoptotic death and autophagic mutp53 elimination were found to be induced by ZP NPs in R280K mutp53-containing MDA-MB-231 cells and hyperthermia was rendered to ameliorate the treatment in vitro through further mutp53 elimination and increased cell death. The combinatorial therapeutic effect was also confirmed in vivo in a mouse model. This study might expand zinc delivery carriers and shed a light on potential interplay of hyperthermia and mutp53 degradation in cancer treatment.     

miR-200c/PAI-2 promotes the progression of triple negative breast cancer via M1/M2 polarization induction of macrophage

PurposeTo investigate the effect of miR-200c/PAI-2 on macrophage polarization into M2-type TAMs in TNBC.Methods and materialsPAI-2 expression in MDA-MB-231^con, MDA-MB-231^miR-200ab and MDA-MB-231^miR-200c breast cancer cells was evaluated by RT-PCR and immunofluorescence (IF), while the expression of the TAM marker F4/80 and the M2-type TAM marker CD206 in MDA-MB-231^con, MDA-MB-231^miR-200c and MDA-MB-231^{miR-200c/siPAI-2} mouse lung metastatic tumor tissues was examined with immunohistochemistry (IHC). The effects of RAW264.7 cells on MDA-MB-231^con, MDA-MB-231^miR-200c and MDA-MB-231^{miR-200c/siPAI-2} were examined by transwell co-culture. CD206 expression in RAW264.7 cells were confirmed by immunostaining. The level of PAI-2 and IL-10 in the co-culture supernatants were assessed using ELISA.Results1. RT-PCR and IF analysis showed that PAI-2 was upregulated in MDA-MB-231^miR-200c cells. 2. IHC assays analysis showed that the numbers of F4/80 and CD206 positive cells were increased in MDA-MB-231^miR-200c tumor tissues, while in MDA-MB-231^{miR-200c/siPAI-2} tumor tissues were decreased. 3. Transwell co-culture assays analysis showed that MDA-MB-231^miR-200c cells significantly promoted the cell migration ability compared with the control group, while knockdown PAI-2 significantly inhibited the cell migration ability (P < 0.05). 4. Transwell co-culture and immunostaining assays analysis showed that overexpression miR-200c in MDA-MB-231 cell line increased the CD206 expression in RAW264.7 cells, while knockdown PAI-2 decreased. 5. ELISA assays analysis showed that miR-200c-mediated MDA-MB-231 cells significantly increased the secretion of PAI-2 and IL-10, while decreased the secretion of PAI-2 and IL-10 in MDA-MB-231 ^{miR-200c/siPAI-2} cells.ConclusionsmiR-200c promotes the malignant progressions of TNBC by PAI-2 upregulation and M2 phenotype macrophages polarization.     

GSH-sensitive polymeric prodrug: Synthesis and loading with photosensitizers as nanoscale chemo-photodynamic anti-cancer nanomedicine

Precisely delivering combinational therapeutic agents has become a crucial challenge for anti-tumor treatment. In this study, a novel redox-responsive polymeric prodrug (molecular weight, MW: 93.5 kDa) was produced by reversible addition–fragmentation chain transfer (RAFT) polymerization. The amphiphilic block polymer-doxorubicin (DOX) prodrug was employed to deliver a hydrophobic photosensitizer (PS), chlorin e6 (Ce6), and the as-prepared nanoscale system [NPs(Ce6)] was investigated as a chemo-photodynamic anti-cancer agent. The glutathione (GSH)-cleavable disulfide bond was inserted into the backbone of the polymer for biodegradation inside tumor cells, and DOX conjugated onto the polymer with a disulfide bond was successfully released intracellularly. NPs(Ce6) released DOX and Ce6 with their original molecular structures and degraded into segments with low MWs of 41.2 kDa in the presence of GSH. NPs(Ce6) showed a chemo-photodynamic therapeutic effect to kill 4T1 murine breast cancer cells, which was confirmed from a collapsed cell morphology, a lifted level in the intracellular reactive oxygen species, a reduced viability and induced apoptosis. Moreover, ex vivo fluorescence images indicated that NPs(Ce6) retained in the tumor, and exhibited a remarkable in vivo anticancer efficacy. The combinational therapy showed a significantly increased tumor growth inhibition (TGI, 58.53%). Therefore, the redox-responsive, amphiphilic block polymeric prodrug could have a great potential as a chemo-photodynamic anti-cancer agent.     

Plumbagin attenuates cancer cell growth and osteoclast formation in the bone microenvironment of mice

Aim： To investigate the effects of plumbagin, a naphthoquinone derived from the medicinal plant Plumbago zeylanica, on human breast cancer cell growth and the cancer cell-induced osteolysis in the bone microenvironment of mice.
Methods： Human breast cancer cell subline MDA-MB-231SA with the ability to spread and grow in the bone was tested. The cell proliferation was determined using the CCK-8 assay. Apoptosis was detected with Annexin V/PI double-labeled flow cytometry. Red fluorescent protein-labeled MDA-MB-231SArfp cells were injected into the right tibia of female BALB/c-nu/nu mice. Three days after the inoculation, the mice were injected with plumbagin （2, 4, or 6 mg/kg, ip） 5 times per week for 7 weeks. The growth of the tumor cells was monitored using an in vivo imaging system. After the mice were sacrificed, the hind limbs were removed for radiographic and histological analyses.

Results： Plumbagin （2.5–20 μmol/L） concentration-dependently inhibited the cell viability and induced apoptosis of MDA-MB-231SA cells in vitro （the IC50 value of inhibition of cell viability was 14.7 μmol/L）. Administration of plumbagin to breast cancer bearing mice delayed the tumor growth by 2–3 weeks and reduced the tumor volume by 44%–74%. The in vivo imaging study showed that plumbagin dose-dependently inhibited MDA-MB-231SArfp cell growth in bone microenvironment. Furthermore, X-ray images and micro-CT study demonstrated that plumbagin reduced bone erosion area and prevented a decrease in bone tissue volume. Histological studies showed that plumbagin dose-dependently inhibited the breast cancer cell growth, enhanced the cell apoptosis and reduced the number of TRAcP-positive osteoclasts.

Conclusion： Plumbagin inhibits the cell growth and induces apoptosis in human breast cancer cells in mice bone microenvironment, leading to significant reduction in osteolytic lesions caused by the tumor cells.     

Hyaluronic Acid Derivative-Based Self-Assembled Nanoparticles for the Treatment of Melanoma

Purpose

Hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs) were developed for the targeted delivery of doxorubicin (DOX), and their antitumor efficacy for melanoma was evaluated.

Methods

DOX-loaded HACE-based self-assembled NPs were prepared and their physicochemical properties were characterized. The in vitro cytotoxicity of HACE was measured using an MTS-based assay. The cellular uptake efficiency of DOX into mouse melanoma B16F10 cells was assessed by confocal laser scanning microscopy and flow cytometry. Tumor growth and body weight were monitored after the intratumoral and intravenous injection of DOX-loaded NPs into a B16F10 tumor-bearing mouse model.

Results

DOX-loaded NPs, with a mean diameter of ~110?nm, a narrow size distribution, and high drug entrapment efficiency, were prepared. A sustained DOX release pattern was shown, and drug release was enhanced at pH 5.5 compared with pH 7.4. The cytotoxicity of HACE to B16F10 cells was negligible. It was assumed that DOX was taken up into the B16F10 cells through receptor-mediated endocytosis. A significant inhibitory effect was observed on tumor growth, without any serious changes in body weight, after the injection of DOX-loaded NPs into the B16F10 tumor-bearing mouse model.

Conclusions

DOX-loaded HACE-based NPs were successfully developed and their antitumor efficacy against B16F10 tumors was demonstrated.