Multiple Treatment of Triple-Negative Breast Cancer Through Gambogic Acid-Loaded Mesoporous Polydopamine.

Triple-negative breast cancer (TNBC) is a highly heterogeneous subtype of breast cancer, characterized by aggressiveness and high recurrence rate. As monotherapy provides limited benefit to TNBC patients, combination therapy emerges as a promising treatment approach. Gambogic acid (GA) is an exceedingly promising anticancer agent. Nonetheless, its application potential is hampered by low drug loading efficiency and associated toxic side effects. To overcome these limitations, using mesoporous polydopamine (MPDA) endowed with photothermal conversion capabilities is considered as a delivery vehicle for GA. Meanwhile, GA can inhibit the activity of heat shock protein 90 (HSP90) to enhance the photothermal effect. Herein, GA-loaded MPDA nanoparticles (GA@MPDA NPs) are developed with a high drug loading rate of 75.96% and remarkable photothermal conversion performance. GA@MPDA NPs combined with photothermal treatment (PTT) significantly inhibit the tumor growth, and effectively trigger the immunogenic cell death (ICD), which thereby increase the number of activated effector T cells (CD8+ T cells and CD4+ T cells) in the tumor, and hoist the level of immune-inflammatory cytokines (IFN-γ, IL-6, and TNF-α). The above results suggest that the combination of GA@MPDA NPs with PTT expected to activate the antitumor immune response, thus potentially enhancing the clinical therapeutic effect on TNBC.

Losartan loaded liposomes improve the antitumor efficacy of liposomal paclitaxel modified with pH sensitive peptides by inhibition of collagen in breast cancer.

The dense collagen network in tumors restricts the penetration of drugs into tumors. Free losartan could inhibit collagen, but it would cause hypotension at the dosage of 10 mg/kg/d. In this study, losartan was encapsulated in liposomes (LST-Lip) and the collagen inhibition ability of LST-Lip was investigated. Our results showed the blood pressure was not affected by LST-Lip at the dosage of 2.5 mg/kg every other day. The amount of Evans Blue in tumor in LST-Lip group was 1.98 times of that in control group. Confocal laser scanning microscopy images showed that prior injection of LST-Lip could inhibit collagen and further improve the tumorous accumulation of liposomes modified with TH peptides (AGYLLGHINLHHLAHL(Aib)HHIL-NH2) (TH-Lip) in 4T1 tumors. Compared with control group, the tumor inhibition rate of combined strategy of LST-Lip and paclitaxel loaded TH-Lip (PTX-TH-Lip) was 41.73%, while that of group only treated with PTX-TH-Lip was 14.94%. Masson's trichrome staining confirmed that collagen was inhibited in LST-Lip group. Thus, the administration of LST-Lip in advance could inhibit the collagen in tumors effectively and did not affect the blood pressure, then PTX-TH-Lip injected subsequently could exert enhanced antitumor efficacy. In conclusion, this combined strategy might be promising for breast cancer therapy.

Polyethylene glycol modification decreases the cardiac toxicity of carbonaceous dots in mouse and zebrafish models.

AIM: Carbonaceous dots (CDs), which have been used for diagnosis, drug delivery and gene delivery, are accumulated in heart at high concentrations. To improve their biocompatibility, polyethylene glycol-modified CDs (PEG-CDs) were prepared. In this study we compared the cardiac toxicity of CDs and PEG-CDs in mouse and zebrafish models. METHODS: Mice were intravenously treated with CDs (size: 4.9 nm, 5 mg·kg(-1)·d(-1)) or PEG-CDs (size: 8.3 nm, 5 mg·kg(-1)·d(-1)) for 21 d. Their blood biochemistry indices, ECG, and histological examination were examined for evaluation of cardiac toxicity. CDs or PEG-CDs was added in incubator of cmlc2 transgenic Zebrafish embryos at 6 hpf, and the shape and size of embryos' hearts were observed at 48 hpf using a fluorescent microscope. Furthermore, whole-mount in situ hybridization was used to examine the expression of early cardiac marker gene (clml2) at 48 hpf. RESULTS: Administration of CDs or PEG-CDs in mice caused mild, but statistically insignificant reduction in serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels detected at 7 d, which were returned to the respective control levels at 21 d. Neither CDs nor PEG-CDs caused significant changes in the morphology of heart cells. Administration of CDs, but not PEG-CDs, in mice caused marked increase of heart rate. Both CDs and PEG-CDs did not affect other ECG parameters. In the zebrafish embryos, addition of CDs (20 µg/mL) caused heart development delay, whereas addition of CDs (80 µg/mL) led to heart malformation. In contrast, PEG-CDs caused considerably small changes in heart development, which was consistent with the results from the in situ hybridization experiments. CONCLUSION: CDs causes greater cardiac toxicity, especially regarding heart development. Polyethylene glycol modification can attenuate the cardiac toxicity of CDs.

[The construction of cell-penetrating peptide R8 and pH sensitive cleavable polyethylene glycols co-modified liposomes].

The purpose of the study is to construct R8 peptide (RRRRRRRR) and pH sensitive polyethylene glycols (PEG) co-modified liposomes (Cl-Lip) and utilize them in breast cancer treatment. The co-modified liposomes were prepared with soybean phospholipid, cholesterol, DSPE-PEG2K-R8 and PEG5K-Hz-PE (pH sensitive PEG). The size and zeta potential of Cl-Lip were also characterized. The in vitro experiment demonstrated that the Cl-Lip had high serum stability in 50% fetal bovine serum. The cellular uptake of Cl-Lip under different pre-incubated conditions was evaluated on 4T1 cells. And the endocytosis pathway, lysosome escape ability and tumor spheroid penetration ability were also evaluated. The results showed the particle size of the Cl-Lip was (110.4 ± 5.2) nm, PDI of the Cl-Lip was 0.207 ± 0.039 and zeta potential of the Cl-Lip was (-3.46 ± 0.05) mV. The cellular uptake of Cl-Lip on 4T1 cells was pH sensitive, as the cellular uptake of Cl-Lip pre-incubated in pH 6.0 was higher than that of pH 7.4 under each time point. The main endocytosis pathways of Cl-Lip under pH 6.0 were micropinocytosis and energy-dependent pathway. At the same time, the Cl-Lip with pre-incubation in pH 6.0 had high lysosome escape ability and high tumor spheroid penetration ability. All the above results demonstrated that the Cl-Lip we constructed had high pH sensitivity and is a promising drug delivery system.

[Cell penetrating peptide TAT and brain tumor targeting peptide T7 dual modified liposome preparation and in vitro targeting evaluation].

The purpose of this study is to prepare T7 and TAT dual modified liposomes (T7-TAT-LIP) to penetrate through blood brain barrier and target to brain tumor cells. The liposomes were prepared with CFPE, T7 modified PEG-DSPE, TAT modified PEG-DSPE, soybean phospholipid, PEG-DSPE and cholesterol. The CFPE was used to track the cellular uptake efficiency. The density of T7 and TAT and the length of PEG were optimized, and then the liposomes were characterized by particle size, zeta potential, morphology and stability. Afterwards, the cellular uptake by bEnd.3 and C6 cells were evaluated. The results showed that the optimized parameters were 6% of T7, 0.5% of TAT, the molecular weight of PEG for T7 was 2000 and the molecular weight of PEG for TAT was 1000. After optimization, the particle size of T7-TAT-LIP was 118 nm, the zeta potential was -6.32 mV and the particles were spherical. The turbidity and particle size of liposomes were not obviously changed after 24 h incubation in PBS at 37 °C. The particle size and polydispersity index were also stable during 1 month incubation at 4-8 °C. The cellular uptake by both bEnd.3 and C6 cells of T7-TAT-LIP was higher than that of T7 or TAT modified liposomes, suggesting dual modified liposomes possessed better blood brain barrier targeting ability and brain tumor targeting ability than the single ligand modified liposomes.

PEGylated fluorescent carbon nanoparticles for noninvasive heart imaging.

Fluorescent carbon nanoparticles (CNP) have gained much attention due to their unique fluorescent properties and safety. In this study, we evaluated the potential application of CNP and PEGylated CNP (PEG-CNP) in noninvasive heart imaging. CNP was prepared by hydrothermal treatment of silk. The particle size and zeta potential of CNP were 121.8 nm and -3.7 mV, respectively, which did not change significantly after PEGylation with a PEG density of 4.43 ± 0.02 µg/mg CNP. FTIR and XPS showed that CNP possessed several functional groups, such as -COOH, -OH, and NH2, which could be utilized for PEGylation and other modifications. CNP displayed strong blue fluorescence after excitation at the wavelength of 375 nm. PEG-CNP displayed better serum stability compared to CNP. The hemolysis rate of PEG-CNP was lower than that of CNP, suggesting PEGylation could enhance the hemocompatibility of CNP. Both CNP and PEG-CNP showed higher uptake capacity by H9c2 cells (a heart cell line) than that by human umbilical vein endothelial cells (HUVEC), suggesting the particles tend to be selectively taken up by heart cells. Both CNP and PEG-CNP were proven to be taken up through endosome-mediated pathway, and the colocalization of nanoparticles with mitochondria was also observed. In vivo results demonstrated that CNP could target heart with much higher fluorescent intensity than liver and spleen. Although PEGylation could decrease the distribution in heart, it remained high for PEG-CNP. In conclusion, CNP could be used for heart imaging, and moreover, PEGylation could improve the stability and biocompatibility of CNP.

Synergistic dual-ligand doxorubicin liposomes improve targeting and therapeutic efficacy of brain glioma in animals.

Therapeutic outcome for the treatment of glioma was often limited due to low permeability of delivery systems across the blood-brain barrier (BBB) and poor penetration into the tumor tissue. In order to overcome these hurdles, we developed the dual-targeting doxorubicin liposomes conjugated with cell-penetrating peptide (TAT) and transferrin (T7) (DOX-T7-TAT-LIP) for transporting drugs across the BBB, then targeting brain glioma, and penetrating into the tumor. The dual-targeting effects were evaluated by both in vitro and in vivo experiments. In vitro cellular uptake and three-dimensional tumor spheroid penetration studies demonstrated that the system could not only target endothelial and tumor monolayer cells but also penetrate tumor to reach the core of the tumor spheroids and inhibit the growth of the tumor spheroids. In vivo imaging further demonstrated that T7-TAT-LIP provided the highest tumor distribution. The median survival time of tumor-bearing mice after administering DOX-T7-TAT-LIP was significantly longer than those of the single-ligand doxorubicin liposomes and free doxorubicin. In conclusion, the dual-ligand liposomes comodified with T7 and TAT possessed strong capability of synergistic targeted delivery of payload into tumor cells both in vitro and in vivo, and they were able to improve the therapeutic efficacy of brain glioma in animals.

Metal coordination nanotheranostics mediated by nucleoside metabolic inhibitors potentiate STING pathway activation for cancer metalloimmunotherapy.

Activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is an effective way to initiate an immune response against tumors, and the research on agonists targeting STING has become a new hotspot in the development of antitumor drugs. However, as a novel STING agonist, the limited bioavailability and activation routes of manganese ions (Mn2+) significantly hinder its antitumor effects. To address these challenges, we have designed a metal-coordinated nucleoside metabolic inhibitor (gemcitabine, Gem)-induced metal nanotheranostic (MGP) with PEGylation. This formulation synergistically enhanced the immune response against cancer cells by sensitizing the cGAS-STING pathway and promoting immunogenic cell death (ICD). Modified with PEG derivatives, MGP was efficiently delivered to the tumor site and was internalized by cancer cells. Upon internalization, the release of Mn2+ triggered the activation of the cGAS-STING pathway, while the release of Gem induced DNA damage. On the one hand, the damaged DNA caused by Gem leaked into the cytoplasm, synergistically amplified Mn2+-induced activation of the cGAS-STING pathway, and induced the production of the tumor cytotoxic factor IFN-ß. On the other hand, Mn2+-mediated chemodynamic therapy (CDT) exhibited an ICD effect, which further synergized with the activation of the cGAS-STING pathway to promote dendritic cells (DCs) maturation and antigen-specific T cells infiltration. Both in vitro and in vivo studies have demonstrated that MGP nanotheranostics could elicit a robust antitumor effect, especially when combined with anti-PD-1. This study provided a new paradigm for intensifying immune activation by constructing metal coordination nanotheranostics.

Self-assembled polymersomes conjugated with lactoferrin as novel drug carrier for brain delivery.

PURPOSE: To develop a novel brain drug delivery system based on self-assembled poly(ethyleneglycol)-poly (D,L-lactic-co-glycolic acid) (PEG-PLGA) polymersomes conjugated with lactoferrin (Lf-POS). The brain delivery properties of Lf-POS were investigated and optimized. METHOD: Three formulations of Lf-POS, with different densities of lactoferrin on the surface of polymersomes, were prepared and characterized. The brain delivery properties in mice were investigated using 6-coumarin as a fluorescent probe loaded in Lf-POS (6-coumarin-Lf-POS). A neuroprotective peptide, S14G-humanin, was incorporated into Lf-POS (SHN-Lf-POS); a protective effect on the hippocampuses of rats treated by Amyloid-ß(25-35) was investigated by immunohistochemical analysis. RESULTS: The results of brain delivery in mice demonstrated that the optimized number of lactoferrin conjugated per polymersome was 101. This obtains the greatest blood-brain barrier (BBB) permeability surface area(PS) product and percentage of injected dose per gram brain (%ID/g brain). Immunohistochemistry revealed the SHN-Lf-POS had a protective effect on neurons of rats by attenuating the expression of Bax and caspase-3 positive cells. Meanwhile, the activity of choline acetyltransferase (ChAT) had been increased compared with negative controls. CONCLUSION: These results suggest that lactoferrin functionalized self-assembled PEG-PLGA polymersomes could be a promising brain-targeting peptide drug delivery system via intravenous administration.

Advanced Biomaterials for Cell-Specific Modulation and Restore of Cancer Immunotherapy.

The past decade has witnessed the explosive development of cancer immunotherapies. Nevertheless, low immunogenicity, limited specificity, poor delivery efficiency, and off-target side effects remain to be the major limitations for broad implementation of cancer immunotherapies to patient bedside. Encouragingly, advanced biomaterials offering cell-specific modulation of immunological cues bring new solutions for improving the therapeutic efficacy while relieving side effect risks. In this review, focus is given on how functional biomaterials can enable cell-specific modulation of cancer immunotherapy within the cancer-immune cycle, with particular emphasis on antigen-presenting cells (APCs), T cells, and tumor microenvironment (TME)-resident cells. By reviewing the current progress in biomaterial-based cancer immunotherapy, here the aim is to provide a better understanding of biomaterials' role in targeting modulation of antitumor immunity step-by-step and guidelines for rationally developing targeting biomaterials for more personalized cancer immunotherapy. Moreover, the current challenge and future perspective regarding the potential application and clinical translation will also be discussed.

Biomimetic Nanomaterials: Diversity, Technology, and Biomedical Applications.

Biomimetic nanomaterials (BNMs) are functional materials containing nanoscale components and having structural and technological similarities to natural (biogenic) prototypes. Despite the fact that biomimetic approaches in materials technology have been used since the second half of the 20th century, BNMs are still at the forefront of materials science. This review considered a general classification of such nanomaterials according to the characteristic features of natural analogues that are reproduced in the preparation of BNMs, including biomimetic structure, biomimetic synthesis, and the inclusion of biogenic components. BNMs containing magnetic, metal, or metal oxide organic and ceramic structural elements (including their various combinations) were considered separately. The BNMs under consideration were analyzed according to the declared areas of application, which included tooth and bone reconstruction, magnetic and infrared hyperthermia, chemo- and immunotherapy, the development of new drugs for targeted therapy, antibacterial and anti-inflammatory therapy, and bioimaging. In conclusion, the authors' point of view is given about the prospects for the development of this scientific area associated with the use of native, genetically modified, or completely artificial phospholipid membranes, which allow combining the physicochemical and biological properties of biogenic prototypes with high biocompatibility, economic availability, and scalability of fully synthetic nanomaterials.

Enhanced intracellular delivery and chemotherapy for glioma rats by transferrin-conjugated biodegradable polymersomes loaded with doxorubicin.

A brain drug delivery system for glioma chemotherapy based on transferrin-conjugated biodegradable polymersomes, Tf-PO-DOX, was made and evaluated with doxorubicin (DOX) as a model drug. Biodegradable polymersomes (PO) loaded with doxorubicin (DOX) were prepared by the nanoprecipitation method (PO-DOX) and then conjugated with transferrin (Tf) to yield Tf-PO-DOX with an average diameter of 107 nm and surface Tf molecule number per polymersome of approximately 35. Compared with PO-DOX and free DOX, Tf-PO-DOX demonstrated the strongest cytotoxicity against C6 glioma cells and the greatest intracellular delivery. It was shown in pharmacokinetic and brain distribution experiments that Tf-PO significantly enhanced brain delivery of DOX, especially the delivery of DOX into brain tumor cells. Pharmacodynamics results revealed a significant reduction of tumor volume and a significant increase of median survival time in the group of Tf-PO-DOX compared with those in saline control animals, animals treated with PO-DOX, and free DOX solution. By terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling, Tf-PO-DOX could extensively make tumor cell apoptosis. These results indicated that Tf-PO-DOX could significantly enhance the intracellular delivery of DOX in glioma and the chemotherapeutic effect of DOX for glioma rats.

The use of myristic acid as a ligand of polyethylenimine/DNA nanoparticles for targeted gene therapy of glioblastoma.

To establish a gene delivery system for brain targeting, a low molecular weight polyethylenimine (PEI(10 K)) was modified with myristic acid (MC), and complexed with DNA, yielding MC-PEI(10 K)/DNA nanoparticles successfully. The nanoparticles were observed to be successfully taken up by the brains of mice. The transfection efficiency of the nanoparticles was then investigated, and both the in vitro and in vivo gene expression of MC-PEI(10 K)/DNA nanoparticles is significantly higher than that of unmodified PEI(10 K)/DNA nanoparticles. The anti-glioblastoma effect of MC-PEI(10 K)/pORF-hTRAIL was demonstrated by the survival time of intracranial U87 glioblastoma-bearing mice. The median survival time of the MC-PEI(10 K)/pORF-hTRAIL group (28 days) was significantly longer than that of the PEI(10 K)/pORF-hTRAIL group (24 days), the MC-PEI(10 K)/pGL(3) group (21 days) and the saline group (22 days). Therefore, our results suggested that MC-PEI(10 K) could be potentially used for brain-targeted gene delivery and in the treatment of glioblastoma.

Unmasking CSF protein corona: Effect on targeting capacity of nanoparticles.

Among biological fluids, cerebrospinal fluid (CSF) not only protects and support brain, but also plays a pivotal role in intracerebral interaction of various nano-drug carriers. However, it is still uncertain how protein corona from CSF affects the targeting capability of functionalized nanoparticles (NPs). So, two types of polystyrene NPs, including PEGylated polystyrene NPs (PN) and transferrin (Tf)-modified PN (PT), were used to obtain protein corona-coated NPs, by incubating with CSF in vivo and in vitro. Strikingly, both the corona-coated NPs recovered in vivo and in vitro completely lost their active targeting characteristics towards bEnd.3 and C6 cells. Charge-, clathrin- and energy-mediated endocytosis contributed to the improved uptake efficiency of PT, whereas this enhancement in uptake of PT was disappeared after the formation of CSF protein corona. Moreover, serum albumin, which were found both in vivo and in vitro CSF corona, could mediate and facilitate the internalization of corona-coated NPs. Overall, these results have distinctly confirmed that the formation of CSF protein corona could cause the loss of active targeting specificity by shielding the targeting groups on the surface of polystyrene NPs and alter their cellular uptake by other non-specific internalization pathways.

Lactoferrin-conjugated biodegradable polymersome holding doxorubicin and tetrandrine for chemotherapy of glioma rats.

The blood-brain barrier (BBB) and multidrug resistance (MDR) are the main causes for poor prognosis of glioma patients after chemotherapy. To explore the way for settling this problem, in this study, a novel antitumor agent loaded drug delivery system, lactoferrin-conjugated biodegradable polymersome holding doxorubicin and tetrandrine (Lf-PO-Dox/Tet), integrating both BBB and glioma-targeting moiety and MDR inhibitor, was designed and its chemotherapy for glioma rats was evaluated. Biodegradable polymersome (PO) encapsulating both doxorubicin (Dox) and tetrandrine (Tet) was prepared by the thin-film hydration method (PO-Dox/Tet) and then conjugated with lactoferrin (Lf) to yield Lf-PO-Dox/Tet with an average diameter around 220 nm and surface Lf molecule number per polymersome around 40. Compared with PO-DOX, PO-Dox/Tet, and Lf-PO-Dox, Lf-PO-Dox/Tet demonstrated the strongest cytotoxicity against C6 glioma cells and the greatest uptake index by C6 cells. In vivo imaging analysis indicated that Lf-PO labeled with a near-infrared dye could enter the brain and accumulate at the tumor site. Pharmacokinetics and tissue distribution results also showed that Lf-PO-Dox/Tet accumulated more in the right hemisphere than other groups of polymersomes. Pharmacodynamics results revealed that tumor volume of the Lf-PO-Dox/Tet group was significantly smaller than that of other therapeutic groups, and the median survival time of Lf-PO-Dox/Tet group was longer than that of Lf-PO-Dox group and significantly longer than those of the other three therapeutic groups. These results suggested that Lf-PO-Dox/Tet could have therapeutic potential for gliomas.

Influence of ligands property and particle size of gold nanoparticles on the protein adsorption and corresponding targeting ability.

Nanoparticulated vesicles were widely used for carriers of drugs and imaging probes. To improve the targeting delivery efficiency of these vesicles, ligands were often functionalized onto their surfaces. However, the interaction between vesicles and plasma proteins may cover the ligands and hinder the targeting delivery. It is important to address the potential influence of ligands modification on plasma protein adsorption and the following targeting delivery. In this study, two common used ligands were chosen as the model: transferrin and RGD peptide. Gold nanoparticles were utilized as model particles. Sodium dodecyl sulfate polyacrylamide gel electrophoresis data demonstrated that higher PEG modification and smaller particle size could reduce the plasma protein adsorption, while ligand modification could increase. The cellular uptake results showed that the targeting ability of smaller ligand RGD peptide would be more easily influenced by the proteins corona.

Efficient siRNA transfer to knockdown a placenta specific lncRNA using RGD-modified nano-liposome: A new preeclampsia-like mouse model.

Preeclampsia is one of the most serious pregnancy complications. Many animal models have already been developed by researchers to study the pathogenesis and treatment of preeclampsia. However, most of these animal models were established by systemic administration or by surgery in the uterine cavity, which could lead to unwanted systemic toxicity or operative wounds and affect the accuracy of the results. Because of the high expression level of integrin αvß3 on the placenta, arginine-glycine-aspartic acid peptide (RGD) modified PEGylated cationic liposome (RGD-Lip) was designed as a novel gene delivery system to target the placenta safely and efficiently, and a new animal model of preeclampsia was established through targeting of long noncoding RNA (lncRNA). The results of cellular uptake and endosomal localization showed that RGD-Lip enhanced cellular uptake and endosomal escape of small interfering RNA (siRNA) on HTR-8/SVneo. In vivo imaging revealed that RGD-Lip was selectively delivered to the placenta. Additionally, H19x siRNA was efficiently transferred into the placenta of C57BL/6 mice via the injection of H19x siRNA-loaded RGD-Lip, which could result in the occurrence of preeclampsia-like symptoms. In summary, RGD-Lip provided a platform to efficiently deliver siRNA to the placenta, and a new preeclampsia-like mouse model was developed targeting placenta enriched/specific genes, including noncoding RNAs.

Targeted delivery of transferrin and TAT co-modified liposomes encapsulating both paclitaxel and doxorubicin for melanoma.

The purpose of this study was to develop an efficient dual-ligand based liposomal drug delivery system with targeting specificity as well as properties that would kill melanoma cells. Liposomes modified with transferrin (Tf) and cell-penetrating peptide TAT was prepared, which encapsulated two kinds of chemotherapy drugs, paclitaxel and doxorubicin (Tf/TAT-PTX/DOX-LP). The Tf ligands specifically bind to the overexpressed Tf receptors on the surface of melanoma cells, while the TAT ligands functioned as a classical cell penetrating peptide, helping dual-ligand liposomes be internalized by melanoma cells. The effect of dual-targeting system and "double-drug" combination therapy were evaluated both in vitro and in vivo. In vitro, cellular uptake, intracellular distribution and tumor spheroids penetration studies demonstrated that the system could not only be selectively and efficiently penetrate melanoma cells. Besides, apoptosis staining assay and cytotoxicity showed effective anti-tumor capability and obvious synergistic effect of combination therapy of PTX and DOX. In vivo imaging and fluorescent images of tumor section further demonstrated that Tf/TAT-PTX/DOX-LP had the highest tumor distribution. The results of these experiments demonstrated that double-drug liposomal drug delivery systems (DDS) had both enhanced targeting efficiency and increased therapeutic efficacy.

Co-delivery of doxorubicin and P-gp inhibitor by a reduction-sensitive liposome to overcome multidrug resistance, enhance anti-tumor efficiency and reduce toxicity.

To overcome multidrug resistance (MDR) in cancer chemotherapy with high efficiency and safety, a reduction-sensitive liposome (CL-R8-LP), which was co-modified with reduction-sensitive cleavable PEG and octaarginine (R8) to increase the tumor accumulation, cellular uptake and lysosome escape, was applied to co-encapsulate doxorubicin (DOX) and a P-glycoprotein (P-gp) inhibitor of verapamil (VER) in this study. The encapsulation efficiency (EE) of DOX and VER in the binary-drug loaded CL-R8-LP (DOX + VER) was about 95 and 70% (w/w), respectively. The uptake efficiencies, the cytotoxicity, and the apoptosis and necrosis-inducing efficiency of CL-R8-LP (DOX + VER) were much higher than those of DOX and the other control liposomes in MCF-7/ADR cells or tumor spheroids. Besides, CL-R8-LP (DOX + VER) was proven to be uptaken into MCF-7/ADR cells by clathrin-mediated and macropinocytosis-mediated endocytosis, followed by efficient lysosomal escape. In vivo, CL-R8-LP (DOX + VER) effectively inhibited the growth of MCF-7/ADR tumor and reduce the toxicity of DOX and VER, which could be ascribed to increased accumulation of drugs in drug-resistant tumor cells and reduced distribution in normal tissues. In summary, the co-delivery of chemotherapeutics and P-gp inhibitors by our reduction-sensitive liposome was a promising approach to overcome MDR, improve anti-tumor effect and reduce the toxicity of chemotherapy.

Synergistic Combination of Doxorubicin and Paclitaxel Delivered by Blood Brain Barrier and Glioma Cells Dual Targeting Liposomes for Chemotherapy of Brain Glioma.

Brain glioma has become a great threat to human health in decades. To maximize the therapeutic efficacy of brain glioma as well as minimize the side effects, drugs should be penetrated through the blood brain barrier (BBB) and then targeted to the brain carcinoma cells with effective concentration. A dual-ligand delivery strategy was employed to achieve both of these goals. Herein, both specific targeting ligand transferrin and cell-penetrating peptide TAT were conjugated onto liposomes (TF/TAT-LP) to develop a brain glioma dual-ligand delivery system. Synergistic combination of doxorubicin (DOX) and paclitaxel (PTX), compared with using them separately, could more efficiently suppress tumor aggravation. In vitro studies including cellular uptake and three-dimensional (3D) tumor spheroid penetration assays proved that TF/TAT-LP could target brain endothelial and carcinoma cells with deeply penetration through the endothelial monolayers and target to the core of the tumor spheroids. In vivo imaging proved that the TF/TAT-LP possesses the highest tumor distribution, which was also confirmed by fluorescent images of the brain section. Ultimately, the DOX and PTX-loaded TF/TAT-LP (TF/TAT-PTX/DOX-LP) shows the best anti-glioma effect with improvement of glioma bearing survival time. In conclusion, synergistic combination of doxorubicin and paclitaxel delivered by the TF/TAT-LP could efficiently target to the brain glioma with satisfying treatment efficiency, which may be a promising formulation for glioma therapy.