Co-delivery of paclitaxel and curcumin loaded solid lipid nanoparticles for improved targeting of lung cancer: In vitro and in vivo investigation

The objective of this study was to develop nanotechnology-mediated paclitaxel (PAC) and curcumin (CUR) co-loaded solid lipid nanoparticles (PAC-CUR-SLNs) for the treatment of lung cancer, which is a leading cause of death worldwide. Around 85 % cases of lungs cancer constitute non-small cell lung cancer (NSCLC). PAC-CUR-SLNs were prepared via high pressure homogenization. The in vitro drug release of PAC-CUR-SLNs was checked followed by their in vitro cytotoxic investigation using adenocarcinomic human alveolar basal epithelial cells (A549) cell lines. Anticancer effects along with side effects of the synergistic delivery of PAC-CUR-SLNs were studied in vivo, using BALB/c mice. PAC-CUR-SLNs were nano sized (190 nm), homogeneously disseminated particles with %IE of both PAC and CUR above 94 %. PAC-CUR-SLNs released PAC and CUR in a controlled fashion when compared with free drug suspensions. The cytotoxicity of PAC-CUR-SLNs was higher than individual drug-loaded SLNs and pure drugs. Moreover, the co-delivery displayed synergistic effect, indicating potential of PAC-CUR-SLNs in lung cancer treatment. In vivo tumor investigation of PAC-CUR-SLNs exhibited 12-fold reduced tumor volume and almost no change in body weight of BALB/c mice, when compared with the experimental groups including control group. The inhibition of tumor rate on day 28 was 82.7 % in the PAC-CUR-SLNs group, which was significantly higher than the pure drugs and monotherapies. It can be concluded that, encapsulating the co-loaded antitumor drugs like PAC-CUR in SLNs may help in improved targeting of the tumor with enhanced anticancer effect.

Advanced nanoscale drug delivery systems for bone cancer therapy

Bone tumors are relatively rare, which are complex cancers and mostly involve the long bones and pelvis. Bone cancer is mainly categorized into osteosarcoma (OS), chondrosarcoma, and Ewing sarcoma. Of these, OS is the most intimidating cancer of the bone tissue, which is mostly found in the log bones in young children and older adults. Conspicuously, the current chemotherapy modalities used for the treatment of OS often fail mainly due to (i) the non-specific detrimental effects on normal healthy cells/tissues, (ii) the possible emergence of drug resistance mechanisms by cancer cells, and (iii) difficulty in the efficient delivery of anticancer drugs to the target cells. To impose the maximal therapeutic impacts on cancerous cells, it is of paramount necessity to specifically deliver chemotherapeutic agents to the tumor site and target the diseased cells using advanced nanoscale multifunctional drug delivery systems (DDSs) developed using organic and inorganic nanosystems. In this review, we provide deep insights into the development of various DDSs applied in targeting and eradicating OS. We elaborate on different DDSs developed using biomaterials, including chitosan, collagen, poly(lactic acid), poly(lactic-co-glycolic acid), polycaprolactone, poly(ethylene glycol), polyvinyl alcohol, polyethyleneimine, quantum dots, polypeptide, lipid NPs, and exosomes. We also discuss DDSs established using inorganic nanoscale materials such as magnetic NPs, gold, zinc, titanium NPs, ceramic materials, silica, silver NPs, and platinum NPs. We further highlight anticancer drugs' role in bone cancer therapy and the biocompatibility of nanocarriers for OS treatment.

Dimeric Artesunate-Phosphatidylcholine-Based Liposomes for Irinotecan Delivery as a Combination Therapy Approach

In this work, dimeric artesunate-phosphatidylcholine conjugate (dARTPC)-based liposomes encapsulated with irinotecan (Ir) were developed for anticancer combination therapy. First, dARTPC featured with unique amphipathic properties formed liposomes by classical thin-film methods. After that, Ir was encapsulated into dARTPC-based liposomes (Ir/dARTPC-LP) by the triethylammonium sucrose octasulfate gradient method. Physicochemical characterization indicated that Ir/dARTPC-LP had a mean size of around 140 nm and a negative ζ potential of approximately -30 mV. Most noticeably, liposomes displayed an encapsulation efficiency of greater than 98% with a controllable drug loading of 4-22%. The in vitro release of dihydroartemisinin (DHA) and Ir from Ir/dARTPC-LP was investigated by dialysis in different media. It was found that effective release of both DHA (65.42%) and Ir (77.28%) in a weakly acidic medium (pH 5.0) after 48 h was achieved in comparison to very slow release under a neutral environment (DHA 9.90% and Ir 8.72%), indicating the controllable release of both drugs. Confocal laser scanning microscopy confirmed the improved cellular internalization of Ir/dARTPC-LP. The cytotoxicity of Ir/dARTPC-LP was evaluated in the MCF-7, A549, and HepG2 cell lines. The results showed that Ir/dARTPC-LP had significant synergistic efficacy in the loss of cell growth. In vivo anticancer evaluation was performed using a 4T1 xenograft tumor model. Ir/dARTPC-LP had a high tumor inhibition rate of 62.7% without significant toxicity in comparison with the injection of Ir solution. Taken together, dARTPC encapsulated with Ir has great potential for anticancer combination therapy.

Co-delivery of doxorubicin and paclitaxel by reduction/pH dual responsive nanocarriers for osteosarcoma therapy

Nanoparticle-based drug delivery system offers a promising platform for combination cancer therapy. However, the inefficient drug release in cells reduces the therapeutic efficacy of cancer nanomedicines. Herein, a PEGylated poly(α-lipoic acid) copolymer (mPEG-PαLA) was prepared and used as a reduction/pH dual responsive nanocarrier to simultaneously deliver paclitaxel (PTX) and doxorubicin (DOX) for osteosarcoma therapy. The amphiphilic mPEG-PαLA could efficiently encapsulate both PTX and DOX during its self-assembly into micelles in aqueous solution to generate PTX and DOX co-loaded nanoparticles (NP-PTX-DOX). The as-prepared NP-PTX-DOX showed enhanced PTX and DOX release in response to reductive and acidic stimuli. Moreover, the dual-drug loaded nanoparticles were efficiently internalized by K7 osteosarcoma cells and released drugs intracellularly, as confirmed by flow cytometry analysis and confocal laser scanning microscopy. Consequently, NP-PTX-DOX exhibited synergistic therapeutic effects and induced enhanced cell apoptosis in K7 cells. Furthermore, NP-PTX-DOX presented improved biodistribution and higher tumor growth inhibition efficacy compared to the control groups in a murine osteosarcoma model. Altogether, the results of this work indicate that the proposed strategy is promising for osteosarcoma therapy using mPEG-PαLA copolymer as a dual-responsive nanocarrier to co-deliver anticancer drugs.

Particle and Gel Characterization of Irinotecan-Loaded Double-Reverse Thermosensitive Hydrogel

The irinotecan-loaded double-reverse thermosensitive hydrogel (DRTH) is a dispersed system of irinotecan-loaded solid lipid nanoparticles (SLN) in a thermosensitive hydrogel. To optimise the particle and gel properties of DRTHs for rectal administration of irinotecan, SLNs and DRTHs were prepared with tricaprin, triethanolamine, Tween 80, and Span 20. Among the SLNs tested, an SLN composed of 1 g irinotecan, 0.5 g lipid mixture, and 0.5 g combined surfactant gave the highest entrapment efficiency and smallest particle size. A DRTH composed of (poloxamer 407/poloxamer 188/combined surfactant/SLN dispersion/H₂O (10/15/17/4/54%)) showed easy administration, fast gelling, and strong gel-forming in the body.

A PEGylated alternating copolymeric prodrug of sulfur dioxide with glutathione responsiveness for Irinotecan delivery

An enhanced anticancer strategy combining the chemotherapy from Irinotecan with the oxidative damage from a sulfur dioxide polymer prodrug is presented.

Targeting cancer cells with nanotherapeutics and nanodiagnostics: Current status and future perspectives

Nanotechnology is reshaping health care strategies and is expected to exert a tremendous impact in the coming years offering better healthcare facilities. It has led to not only therapeutic drug delivery feasibility but also to diagnostics. Materials in the size of nano range (1-100 nm) used in the design, fabrication, regulation, and application of therapeutic drugs or devices are classified as medical nanotechnology and nanopharmacology. Delivery of more complex molecules to the specific site of action as well as gene therapy has pushed forward the nanoparticle-based drug delivery to its maximum. Areas that benefit from nano-based drug delivery systems are cancer, diabetes, infectious diseases, neurodegenerative diseases, blood disorders and orthopedic-related ailments. Moreover, development of nanotherapeutics with multi-functionalities has a considerable potential to fill the gaps that exist in the present therapeutic domain. In cancer treatment, nanomedicines have superiority over current therapeutic practices as they can effectively deliver the drug to the affected tissues, thus reducing drug toxicities. Along this line, polymeric conjugates of asparaginase and polymeric micelles of paclitaxel have recently been recommended for the treatment of various types of cancers. Nanotechnology-based therapeutics and diagnostics provide greater effectiveness with less or no toxicity concerns. Similarly, diagnostic imaging holds promising future applications with newer nano-level imaging elements. Advancements in nanotechnology have emerged to a newer direction which use nanorobotics for various applications in healthcare. Accordingly, this review comprehensively highlights the potentialities of various nanocarriers and nanomedicines for multifaceted applications in diagnostics and drug delivery, especially the potentialities of polymeric nanoparticle, nanoemulsion, solid-lipid nanoparticle, nanostructured lipid carrier, self-micellizing anticancer lipids, dendrimer, nanocapsule and nanosponge-based therapeutic approaches in the field of cancer. Furthermore, this article summarizes the most recent literature pertaining to the use of nano-technology in the field of medicine, particularly in treating cancer patients.

Vitamin E-based prodrug self-delivery for nanoformulated irinotecan with synergistic antitumor therapeutics

Irinotecan (Ir) is a potent antitumor chemotherapeutics in clinic and used for the treatment of a various cancers, but the degree of its application is critically limited by toxic side-effects and marked heterogeneities. Nano-formulation of prodrugs, based on "all-in-one" carrier-free self-assemblies offers an effective approach to alter pharmacokinetics and safety profiles of cytotoxic agents. In this study, a novel vitamin E succinate-based formulation of Ir (VES-Ir) combined with nanoscaled characteristics and synergistic combination was constructed through esterification. The conjugation makes amphiphilic VES-Ir prodrug self-assemble into nanoparticles with a fine diameter (VES-Ir NPs, 75.4 nm) of spherical morphology. Furthermore, VES-Ir NPs with a 1:1 drug-to-drug ratio was demonstrated to possess respectable physiological stability within 72 h test, while can react to pH/esterase-sensitive drug release in lysosomes internalized into tumor cells, potentially highlighting their alleviating side effects. Compared with single and mixture drugs administration, the nanoformulated VES-Ir NPs codelivered both VES and Ir with different anticancer mechanisms to induce the highest suppress proliferation of MCF-7 (IC₅₀ 0.18 μM) and A549 (IC₅₀ 0.29 μM) cells in a synergistic way (CI < 1). More importantly, the formulating nanoparticulate Ir is to significantly enhance its bioavailability in vivo with long retention time in bloodstream and thereby, resulting the superior tumor inhibitory rate (TIR) of 85.2% versus controls. This simple nanoformulation of Ir drug deprived from VES conjugation, together with self-delivery and synergistic property, may provide an effective strategy for multiple chemotherapeutics delivery to treat cancers or other diseases.

Indocyanine green/doxorubicin-encapsulated functionalized nanoparticles for effective combination therapy against human MDR breast cancer

To overcome low therapeutic efficacy of chemotherapy against multidrug resistance (MDR) breast cancer, a combination therapy system based upon functionalized polymer nanoparticles comprising poly(γ-glutamic acid)-g-poly(lactic-co-glycolic acid) (γ-PGA-g-PLGA) as the major component was developed. The NPs were loaded with doxorubicin (DOX) and indocyanine green (ICG) for dual modality cancer treatment and coated with cholesterol-PEG (C-PEG) for MDR abrogation in treatment of human MDR breast cancer. The in vitro cellular uptake of the DOX/ICG loaded nanoparticles (DI-NPs) by MDR cancer cells was significantly enhanced owing to effective inhibition of the P-gp activity by C-PEG and γ-PGA receptor-mediated endocytosis. DOX localization in cytoplasm and nucleus was observed particularly with the photo-thermal effect that facilitated intracellular drug release. As a result, the C-PEG coated DI-NPs after photo-irradiation exhibited a synergistic effect of combination (chemo/thermal) therapy to depress the proliferation of MDR cancer calls. The ex vivo biodistribution study revealed an enhanced tumor accumulation of C-PEG (2000) coated DI-NPs in MCF-7/MDR tumor-bearing nude mice due to the excellent EPR effects by the NP surface PEGylation. The MDR tumor growth was almost entirely inhibited in the group receiving combination therapy from CP2k-DI-NPs and photo-irradiation along with substantial cell apoptosis of tumor tissues examined by immunohistochemical staining. The results demonstrate a promising dual modality therapy system, CP2k-DI-NPs, developed in this work for effective combination therapy of human MDR breast cancer.

Therapeutic polymeric nanomedicine: GSH-responsive release promotes drug release for cancer synergistic chemotherapy

To obtain an efficient dual-drug release and enhance therapeutic efficiency for combination chemotherapy, a glutathione (GSH)-responsive therapeutic amphiphilic polyprodrug copolymer (mPEG-b-PCPT) is synthesized to load doxorubicin (DOX) via hydrophobic and π–π stacking interaction. In this nanomedicine system (mPEG-b-PCPT/DOX), the ratio of the two drugs can be easily modulated by changing the loading content of DOX. The in vitro drug release curves and laser confocal images suggested that the release of CPT and DOX is induced through a “release promotes release strategy”: after internalization into tumor cells, the disulfide bonds in the nanomedicine are cleaved by glutathione (GSH) in the cytoplasm and then lead to the release of CPT. Meanwhile, the disassembly of nanomedicine immediately promotes the co-release of DOX. The optimum dose ratio of CPT and DOX is evaluated via the combination index (CI) value using HepG-2 cells. The results of cell apoptosis and cell viability prove the better synergistic efficiency of the nanomedicine than free drugs at the optimum dose ratio of 1. Consequently, this stimuli-responsive synergistic chemotherapy system provides a direction for the fabrication of nanomedicines possessing promising potential in clinical trials.

In the GSH-responsive doxorubicin loading camptothecin prodrug nanomedicine, easy modulation of the dose ratio and controlled co-release were achieved, and the synergistic effect was significantly improved.

Biodegradable Nanoparticles Mediated Co-delivery of Erlotinib (ELTN) and Fedratinib (FDTN) Toward the Treatment of ELTN-Resistant Non-small Cell Lung Cancer (NSCLC) via Suppression of the JAK2/STAT3 Signaling Pathway

Background: Erlotinib (ELTN)-based targeted therapy as first-line treatment for epidermal growth factor receptor (EGFR)-mutant lung cancers suffers from insufficient selectivity, side effects, and drug resistance, which poses critical challenges in the clinical setting. Acquired resistance of ELTN results in extremely poor prognoses of non-small cell lung cancer (NSCLC) patients, wherein activation of the JAK2/STAT3 signaling pathway has been proven to induce acquired ELTN resistance.

Methods: In this study, we developed a nanoparticle (NP) delivery system based on Food and Drug Administration (FDA)-approved poly(ethylene glycol) (PEG)-poly(lactic acid) (PLA) for the co-delivery of ELTN and fedratinib (FDTN, a small-molecular, highly selective JAK2 inhibitor). Both ELTN and FDTN could be encapsulated into the PEG-PLA NPs via optimization of the encapsulation method. The effect of NPs on NSCLC cells was evaluated by MTT assay. Western blotting was performed to study the molecular mechanisms of NPs inhibiting the downstream pathways of EGFR in vitro. The histological analysis and protein expression in vivo were assessed by hematoxylin/eosin (H&E) staining and immunohistochemistry, respectively.

Results: The drug cargoes exhibited great stability, and could be released more efficiently in the acidic tumorous condition. Mechanistic study showed that FDTN notably down-regulated the expression levels of proteins in the JAK2/STAT3 signaling pathway, including p-EGFR, p-JAK2, p-STAT3 and Survivin, therefore reversing the ELTN resistance. As a result, synergistic anti-cancer effect was achieved by PEG-PLA NPs encapsulating both ELTN and FDTN in ELTN-resistant NSCLC tumors both in vitro and in vivo, and lower systemic side effect was noted for the co-delivery NPs compared to free drugs.

Conclusion: This study provides a promising approach to overcome the ELTN resistance in the treatment of NSCLC, and the use of FDA-approved materials with clinically applied/investigated chemical drugs may facilitate the translation of the current delivery system.

Autophagy Inhibitor (LY294002) and 5-fluorouracil (5-FU) Combination-Based Nanoliposome for Enhanced Efficacy Against Esophageal Squamous Cell Carcinoma

In this study, 5-fluorouracil (5-FU) and LY294002 (LY)-loaded PEGylated nanoliposome was prepared to target esophageal squamous cell carcinoma (ESCC). The particles were characterized in terms of physicochemical and biological parameters. The co-delivery of autophagy inhibitor and chemotherapeutic drug in a single carrier was successfully accomplished. The two components from 5-FU and LY-loaded PEGylated nanoliposome (FLNP) released in a controlled manner with LY relatively released faster compared to that of 5-FU. FLNP showed a receptor-mediated cellular uptake that will allow the gradual release of drug in the acidic environment. The cellular uptake of nanoparticles (NP) was further confirmed by FACS analysis. The combination of 5-FU and LY resulted in higher cytotoxic effect compared to that of individual drugs. Most importantly, FLNP exhibited a significantly higher anticancer effect in cancer cells compared to that of free cocktail combinations. The faster release of LY from FLNP leads to autophagy inhibition that improves the sensitivity of cancer cells towards 5-FU, resulting in more cell death. Consistently, FLNP induced a greater apoptosis (~ 48%) of cancer cells compared to that of any other groups. Western blot analysis clearly showed that 5-FU and LY individually increased the expression of caspase-3 and PARP, while as expected FLNP induced a remarkable expression of these protein markers indicating the superior anticancer effect. We believe that the programmed release of autophagy inhibitor and chemotherapeutic drug from a single nanocarrier will increase the prospect of anticancer therapy in ESCC.

Folic acid-conjugated mesoporous silica nanoparticles for enhanced therapeutic efficacy of topotecan in retina cancers

In this study, topotecan-loaded mesoporous silica nanoparticles were prepared and surface conjugated with folic acid (FTMN) to enhance the therapeutic efficacy of topotecan for the treatment of retinoblastoma (RB) cancers. The particles were nano-sized and exhibited a sustained release of drug in the physiological conditions. The folic acid-conjugated nanoformulations exhibited a remarkable uptake in RB cells compared to that of non-targeted nanoparticles. These results clearly indicate that receptor-mediated endocytosis is the mechanism of cellular internalization. The greater cellular uptake of FTMN resulted in significantly higher cytotoxic effect in Y79 cancer cells compared to that of other formulations. The results were well corroborated with the live/dead assay and nuclear fragmentation assay. FTMN consistently induced apoptosis of cancer cells with an efficiency of ~58%. Our results clearly showed that nanoparticulate encapsulation of TPT exhibited superior anticancer efficacy in Y79 cancer cells compared to that of free drug or non-targeted nanoparticles. As expected, FTMN exhibited a remarkable reduction in the overall tumor volume compared to any other group with less presence of tumor cells in histology staining. Overall, folic acid-conjugated nanoparticulate system could provide an effective platform for RB treatment.

Polysaccharide-modified nanoparticles with intelligent CD44 receptor targeting ability for gene delivery

BACKGROUND

Hyaluronic acid (HA) and chondroitin sulfate (CD) are endogenous polysaccharides. In recent years, they have aroused the interest of scientists because of specific binding to CD44 receptors, which are overexpressed in several types of tumors.

METHODS

In this study, HA- and CD-modified poly(D,L-lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) copolymers were synthesized and applied to encapsulate 1,2-Dioleoyl-3-trimethylammonium-propane (DOTAP)/pDNA (D/P) lipoplex as CD44 receptor targeting gene delivery nanoparticles (NPs).

RESULTS

The particle size of CD-PEG-PLGA-D/P (186.8 ± 21.7 nm) was smaller than that of HA-PEG-PLGA-D/P (270.2 ± 13.8 nm), with narrow size distribution, and both HA-PEG-PLGA-D/P NPs and CD-PEG-PLGA NPs possessed negative zeta potentials (-39.63 ± 5.44 mV and -38.9 ± 2.0 mV, respectively), which prevent erythrocytes from agglutination. Both NPs exhibited pH-dependent release and had faster release in pH 4.0 than in pH 7.4. Generally, the CD-PEG-PLGA-D/P NPs possessed less cytotoxicity than HA-PEG-PLGA-D/P NPs. The D/P-loaded HA-PEG-PLGA and CD-PEG-PLGA NPs expressed significantly higher transfection in CD44 high-expressed U87 (30.1% ± 2.1% and 40.7% ± 4.3%, respectively) than in CD44-negative HepG2 (3.3% ± 1.5% and 1.4% ± 1.0%, respectively) (p < 0.001). It was revealed that the endocytosis of HA-PEG-PLGA-D/P NPs was majorly dominated by macropinocytosis and the endocytosis of CD-PEG-PLGA-D/P NPs was dominated by clathrin-mediated endocytosis pathway (p < 0.001).

CONCLUSION

The high selectivity to CD44-positive U87 cancer cells and low cytotoxicity in L929 normal cells assured the promising potential of CD-PEG-PLGA NPs as gene delivery nano-carriers.

Fabrication of a triptolide-loaded and poly-γ-glutamic acid-based amphiphilic nanoparticle for the treatment of rheumatoid arthritis

Triptolide (TP) exhibits immunosuppressive, cartilage-protective and anti-inflammatory effects in rheumatoid arthritis. However, the toxicity of TP limits its widespread use. To decrease the toxic effects, we developed a novel nano-drug carrier system containing TP using poly-γ-glutamic acid-grafted di-tert-butyl L-aspartate hydrochloride (PAT). PAT had an average diameter of 79±18 nm, a narrow polydispersity index (0.18), a strong zeta potential (−32 mV) and a high drug encapsulation efficiency (EE₁=48.6%) and loading capacity (EE₂=19.2%), and exhibited controlled release (t_1/2=29 h). The MTT assay and flow cytometry results indicated that PAT could decrease toxicity and apoptosis induced by free TP on RAW264.7 cells. PAT decreased lipopolysaccharides/interferon γ-induced cytokines expression of macrophage (P<0.05). In vivo, PAT accumulated at inflammatory joints, improved the survival rate and had fewer side effects on tumor necrosis factor α transgenic mice, compared to TP. The blood biochemical indexes revealed that PAT did not cause much damage to the kidney (urea nitrogen and creatinine) and liver (alanine aminotransferase and aspartate aminotransferase). In addition, PAT reduced inflammatory synovial tissue area (P<0.05), cartilage loss (P<0.05), tartrate-resistant acid phosphatase-positive osteoclast area (P<0.05) and bone erosion (P<0.05) in both knee and ankle joints, and showed similar beneficial effect as free TP. In summary, our newly formed nanoparticle, PAT, can reduce the toxicity and guarantee the efficacy of TP, which represents an effective drug candidate for RA with low adverse side effect.

Combination of Oxaliplatin and Vit.E-TPGS in Lipid Nanosystem for Enhanced Therapeutic Efficacy in Colon Cancers

PURPOSE

The main aim of present study was to prepare the oxaliplatin (OXL)-loaded D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS)-based lipid nanoparticles to enhance the anticancer effect in colon cancer cells.

METHODS

The nanoparticles were nanosized and spherical shaped and exhibited controlled release kinetics. Flow cytometer and confocal laser scanning microscopy (CLSM) showed a remarkable uptake of nanoparticles in cancer cells in a time-dependent manner.

RESULTS

The presence of TPGS remarkably increased the anticancer effect of OXL in HT-29 colon cancer cells. The IC50 value of free OXL was 4.25 μg/ml whereas IC50 value of OXL-loaded TPGS-based lipid nanoparticles (OXL/TLNP) was 1.12 μg/ml. The 3-fold lower IC50 value of OXL/TLNP indicates the superior anticancer effect of nanoparticle-based OXL. Consistently, OXL/TLNP induced a remarkable apoptosis of cancer cells. Approximately, ~52% of cells were in early apoptosis phase and ~13% of cells were in late apoptosis phase indicating the potent anticancer effect of the formulations. The findings from this study provide novel insights into the use of TPGS and lipid nanoparticle together for the better antitumor effect in colon cancers. Future studies will involve the detailed in vitro and in vivo studies on clinically relevant animals.

Facile construction of bioreducible crosslinked polypeptide micelles for enhanced cancer combination therapy

In this study, we developed pH and redox-responsive crosslinked polypeptide-based combination micelles for enhanced chemotherapeutic efficacy and minimized side effects. The stability and drug release properties of the polypeptide micelles were efficiency balanced by the corona-crosslinking of the triblock copolymer, poly(ethylene glycol)-b-poly(aspartic acid)-b-poly(tyrosine) (PEG-b-pAsp-b-pTyr) with coordinated redox and pH dual-sensitivity by introducing disulfide crosslinkages. Because of the crosslinking of the middle shell of the triblock polypeptide micelles, their robust structure was maintained in strong destabilization conditions and exhibited excellent stability. GSH concentrations were significantly higher in tumor tissue than in normal tissue, which formed the basis for our design. Drug release was elevated under redox and low acidic conditions. Furthermore, crosslinked micelles showed a superior anticancer effect compared to that of non-crosslinked micelles. Incorporation of docetaxel (DTX) and lonidamine (LND) in crosslinked polypeptide micelles increased the intracellular reactive oxygen species (ROS) level and oxidative stress and caused damage to intracellular components that resulted in greater apoptosis of cancer cells than when DTX or LND was used alone. The combination of DTX and LND in crosslinked micelles exhibited efficacious inhibition of tumor growth with an excellent safety profile compared to that reported for drug cocktail combinations and non-crosslinked micelles. Overall, redox/pH-responsive polypeptide micelles could be an interesting platform for efficient chemotherapy.

STATEMENT OF SIGNIFICANCE

We have synthesized a biodegradable polypeptide block copolymer to construct a facile pH and redox-responsive polymeric micelle asan advanced therapeutic system for cancer therapy. We have designed a corona-crosslinked triblock copolymer (poly (ethylene glycol)-b-poly(aspartic acid)-b-poly(tyrosine) (PEG-b-pAsp-b-pTyr)) micelles co-loaded with docetaxel and lonidamine (cl-M/DL). The corona of triblock polymer was crosslinked to maintain its structural integrity in the physiological environment. The mitochondrial targeting LND is expected to generate ROS, oxidative stress and thereby synergize the chemotherapeutic efficacy of DTX in killing cancer cells. Consistently, cl-M/DL exhibited excellent antitumor efficacy in xenograft tumor model with remarkable tumor regression. Overall, we demonstrated the construction of bioreducible nanosystem for the effective synergistic delivery of DTX/LND in tumor tissues towards cancer treatment.

Polymer-lipid hybrid nanoparticles-based paclitaxel and etoposide combinations for the synergistic anticancer efficacy in osteosarcoma

In this study, paclitaxel and etoposide-loaded lipid-polymer hybrid nanoparticles (PE-LPN) was successful prepared and evaluated for physicochemical and anticancer effect. Nanosized PE-LPN was obtained with a perfect spherical morphology. PE-LPN exhibited a controlled release of two drugs in a sequential manner. The nanoparticles exhibited a typical endocytosis-mediated cellular uptake in cancer cells. The ratiometric combination of paclitaxel (PTX) and etoposide (ETP) were significantly more cytotoxic than individual drugs. Importantly, superior cytotoxic effect was observed for dual-drug-loaded PE-LPN than cocktail combination at a much lower dose. Similarly, PE-LPN exhibited a significantly higher apoptosis of cancer cells (∼45%) compared to that of any other groups with higher caspase-3 and -8 activity. Importantly, PE-LPN showed a remarkable tumor regression effect and exhibited a 2-fold superior efficacy than free drugs. PE-LPN treated group showed significantly less Ki-67 positive cells (less than 25%) than PTX/ETP and single drug treated groups, suggesting less active cell proliferation and a considerably higher tumor growth inhibition effect. The results collectively showed that combination of drugs could greatly improve the therapeutic property of chemotherapeutic drugs. By combining ETP with PTX (a powerful anticancer drug) in a polymer-lipid hybrid nanoparticle system, therapeutic efficacy could be improved in osteosarcoma treatments.

Engineering of multifunctional temperature-sensitive liposomes for synergistic photothermal, photodynamic, and chemotherapeutic effects

Heterogeneity of cancer cells and drug resistance require multiple therapeutic approaches for comprehensive treatment. In this study, temperature-sensitive liposomes containing anti-cancer agent tanespimycin (17-AAG) and photosensitizer IR 820 were developed for combination of phototherapy and chemotherapy. The temperature-sensitive liposomes composed of DPPC, cholesterol, DSPE-PEG, 17-AAG, and IR 820 (LP-AI) at weight ratio of 35/15/3/2/2 were formulated as a thin film using extrusion and evaluated for particle size, morphology and drug release profile. Furthermore, the anticancer effect of combined therapy was examined in vitro and in vivo in SCC-7 and MCF-7 cell lines. As a result, LP-AI was prepared at particle size of 166.7±1.3nm, PDI of 0.153±0.012, and ζ-potential of -32.6±0.8mV. After NIR irradiation (660 and 808nm laser), LP-AI could generate heat and ROS and enhance drug release from nanoparticles which were useful to kill the cancer cells. These were confirmed by in vitro cytotoxicity as well as in vivo effective ablation of tumors. In conclusion, fast drug release and enhanced treatment efficacy of LP-AI indicate the potential of integrating photo- and chemotherapy for synergistic anti-cancer effects.

Combined photothermal and photodynamic therapy by hyaluronic acid-decorated polypyrrole nanoparticles

Aim: To develop a nanoparticle-based platform using polypyrrole and IR-780 for effective combined photothermal and photodynamic therapy. Materials & methods: IR-780 was loaded in a poly(lactic-co-glycolic acid) core, decorated with polypyrrole shells and hyaluronic acid (IPPH). Physicochemical properties and in vitro and in vivo anticancer effects of these nanoparticles were evaluated. Results: The resulting IPPHs were spherical, small and negatively charged. Under near-infrared laser irradiation, the IPPHs generated reactive oxygen species and heat and synergistically improved therapeutic efficacy. The antitumor effects were confirmed by in vitro cellular reactive oxygen species detection and cytotoxicity assays, and in vivo in a xenograft tumor model, with no damage to body organs. Conclusion: Our results indicate the potential of applying IPPH in oncology nanomedicine.

Capsaicin-loaded folic acid-conjugated lipid nanoparticles for enhanced therapeutic efficacy in ovarian cancers

In this study, folic acid-conjugated lipid nanoparticles were successfully prepared to enhance the active targeting of capsaicin (CAP) in ovarian cancers. The particles were nanosized and exhibited a controlled release of drug in the physiological conditions. The folic acid (FA)-conjugated system exhibited a remarkably higher uptake of nanoparticles in the cancer cells compared to that of non-targeted system. The folate-conjugated CAP-loaded lipid nanoparticles (CFLN) upon interacting with cancer cells were internalized via receptor-mediated endocytosis mechanism and resulted in higher concentration in the cancer cells. Consistently, CFLN showed a remarkably higher toxic effect compared to that of non-targeted nanoparticle system. CFLN showed significantly higher cancer cell apoptosis with nearly 39% of cells in apoptosis chamber (early and late) compared to only ∼21% and ∼11% for CAP-loaded lipid nanoparticles (CLN) and CAP. The loading of drug in the lipid nanoparticle system extended the drug retention in the blood circulation and allowed the active targeting to specific cancer cells. The prolonged circulation of drug attributed to the antifouling property of polyethylene glycol molecule in the structure. Overall, study highlights that using targeting moiety could enhance the therapeutic response of nanomedicines in the treatment of solid tumors.

Irinotecan-loaded double-reversible thermogel with improved antitumor efficacy without initial burst effect and toxicity for intramuscular administration

Intramuscularly administered, anti-tumour drugs induce severe side effects due to their direct contact with body tissues and initial burst effect. In this study, to solve this problem, a novel double-reversible thermogel system (DRTG) for the intramuscular administration of irinotecan was developed. This irinotecan-loaded DRTG was prepared by dispersing the irinotecan-loaded thermoreversible solid lipid nanoparticles (SLNs) in the thermoreversible hydrogel. In DRTG, the former was solid at 25°C but converted to liquid at 36.5°C; in contrast, the latter existed in a liquid form but transformed to gel state in the body. The DRTG was easily administered intramuscularly. Its particle size and drug content were not noticeably changeable, resulting that it was stable at 40°C for at least 6months. Compared to the irinotecan-loaded solution and conventional hydrogel, the DRTG significantly delayed drug release, leading to a reduced burst effect. Moreover, it showed decreased C_max and maintained the sustained plasma concentrations at a relatively low level for the long period of 60h in rats, resulting in ameliorated side effects of the anti-tumour drug. Furthermore, it gave significantly improved anti-tumour efficacy in tumour-bearing mice compared to the hydrogel but, unlike the conventional hydrogel, induced no body weight loss and local damage to the muscle. Thus, this DRTG with improved antitumor efficacy without initial burst effect and toxicity could provide a potential pharmaceutical system for the intramuscular administration of irinotecan.

STATEMENT OF SIGNIFICANCE

Intramuscularly administered, anti-tumour drugs induce severe side effects due to their direct contact with body tissues and initial burst effect. To solve this problem, we developed a novel double-reversible thermogel system (DRTG) for the intramuscular administration of irinotecan. Unlike the conventional hydrogel, the DRTG is a dispersion of the irinotecan-loaded thermoreversible solid lipid nanoparticles in the thermoreversible hydrogel. In DRTG, the former was solid at 25°C but converted to liquid at 36.5°C; in contrast, the latter existed in a liquid form but transformed to gel state in the body. This DRTG gave significantly improved anti-tumour efficacy in tumour-bearing mice compared to the hydrogel but, unlike the conventional hydrogel, induced no body weight loss and local damage to the muscle.

Irinotecan-encapsulated double-reverse thermosensitive nanocarrier system for rectal administration

Intravenously administered for the treatment of rectum cancer, irinotecan produces severe side effects due to very high plasma concentrations. A novel irinotecan-encapsulated double reverse thermosensitive nanocarrier system (DRTN) for rectal administration was developed as an alternative. The DRTN was fabricated by dispersing the thermosensitive irinotecan-encapsulated solid lipid nanoparticles (SLN) in the thermosensitive poloxamer solution. Its gel properties, pharmacokinetics, morphology, anticancer activity and immunohistopathology were assessed after its rectal administration to rats and tumor-bearing mice. In the DRTN, the solid form of the SLN and the liquid form of the poloxamer solution persisted at 25 °C; the former melted to liquid, and the latter altered to gel at 36.5 °C. The DRTN was easily administered to the anus, gelling rapidly and strongly after rectal administration. Compared to the conventional hydrogel and intravenously administered solution, it retarded dissolution and initial plasma concentration. The DRTN gave sustained release and nearly constant plasma concentrations of irinotecan at 1–3 h in rats, resulting in improved anticancer activity. It induced no damage to the rat rectum and no body weight loss in tumor-bearing mice. Thus, this irinotecan-encapsulated DRTN associated with a reduced burst effect, lack of toxicity and excellent antitumor efficacy would be strongly recommended as a rectal pharmaceutical product alternative to commercial intravenous injection in the treatment of rectum and colon cancer.

Precise Engineering of Prodrug Cocktails into Single Polymeric Nanoparticles for Combination Cancer Therapy: Extended and Sequentially Controllable Drug Release

The synergistic combination of two or more chemotherapeutics frequently requires packaging in single delivery vehicles for the sequential release of each substance in a predictable manner. Here, we demonstrate for the first time that the rational engineering of a prodrug cocktail into single polymeric nanoparticles (NPs) can enable the sequential release of chemotherapeutics in a controllable manner. Exploiting combretastatin-A4 (CA4, 1) as a model antiangiogenesis agent, two ester derivatives, 2 and 3, tethered with saturated fatty acids (butanoic and heptanoic acid for 2 and 3, respectively) were synthesized. 7-Ethyl-10-hydroxycamptothecin (SN38) derivative 4, esterified with α-linolenic acid, was used as a cytotoxic drug. Because of their augmented lipophilicity and miscibility, all constructed prodrugs readily assembled with clinically approved polymeric matrices. Results showed that altering the aliphatic chains of modifiers for CA4 chemical derivatization enabled the drug retention capacity within particle systems to be adjusted, leading to the identification of the prodrug cocktail of 2 and 4 as an optimal combination for subsequent preclinical studies. Furthermore, in vivo assessements indicated that the resulting NPs simultaneously formulating 2 and 4 exhibited synergistic activities and outperformed NPs loaded with individual prodrugs 2 or 4 in terms of therapeutic efficacy. These findings highlight a novel and versatile strategy for tailoring chemically disparate prodrug cocktails for adaptation within a single nanoplatform as a potential modality for synergistic cancer therapy.

Co-delivery nanoparticles with characteristics of intracellular precision release drugs for overcoming multidrug resistance

Combination chemotherapy in clinical practice has been generally accepted as a feasible strategy for overcoming multidrug resistance (MDR). Here, we designed and successfully prepared a co-delivery system named S-D1@L-D2 NPs, where denoted some smaller nanoparticles (NPs) carrying a drug doxorubicin (DOX) were loaded into a larger NP containing another drug (vincristine [VCR]) via water-in-oil-in-water double-emulsion solvent diffusion-evaporation method. Chitosan-alginate nanoparticles carrying DOX (CS-ALG-DOX NPs) with a smaller diameter of about 20 nm formed S-D1 NPs; vitamin E D-α-tocopheryl polyethylene glycol 1000 succinate-modified poly(lactic-co-glycolic acid) nanoparticles carrying VCR (TPGS-PLGA-VCR NPs) with a larger diameter of about 200 nm constituted L-D2 NPs. Some CS-ALG-DOX NPs loaded into TPGS-PLGA-VCR NPs formed CS-ALG-DOX@TPGS-PLGA-VCR NPs. Under the acidic environment of cytosol and endosome or lysosome in MDR cell, CS-ALG-DOX@TPGS-PLGA-VCR NPs released VCR and CS-ALG-DOX NPs. VCR could arrest cell cycles at metaphase by inhibiting microtubule polymerization in the cytoplasm. After CS-ALG-DOX NPs escaped from endosome, they entered the nucleus through the nuclear pore and released DOX in the intra-nuclear alkaline environment, which interacted with DNA to stop the replication of MDR cells. These results indicated that S-D1@L-D2 NPs was a co-delivery system of intracellular precision release loaded drugs with pH-sensitive characteristics. S-D1@L-D2 NPs could obviously enhance the in vitro cytotoxicity and the in vivo anticancer efficiency of co-delivery drugs, while reducing their adverse effects. Overall, S-D1@L-D2 NPs can be considered an innovative platform for the co-delivery drugs of clinical combination chemotherapy for the treatment of MDR tumor.

Molecularly targeted co-delivery of a histone deacetylase inhibitor and paclitaxel by lipid-protein hybrid nanoparticles for synergistic combinational chemotherapy

In this study, a transferrin-anchored albumin nanoplatform with PEGylated lipid bilayers (Tf-L-APVN) was developed for the targeted co-delivery of paclitaxel and vorinostat in solid tumors. Tf-L-APVN exhibited a sequential and controlled release profile of paclitaxel and vorinostat, with an accelerated release pattern at acidic pH. At cellular levels, Tf-L-APVN significantly enhanced the synergistic effects of paclitaxel and vorinostat on the proliferation of MCF-7, MDA-MB-231, and HepG2 cancer cells. Vorinostat could significantly enhance the cytotoxic potential of paclitaxel, induce marked cell apoptosis, alter cell cycle patterns, and inhibit the migratory capacity of cancer cells. In addition, Tf-L-APVN showed prolonged circulation in the blood and maintained an effective ratio of 1:1 (for paclitaxel and vorinostat) throughout the study period. In HepG2 tumor-bearing mice, Tf-L-APVN displayed excellent antitumor efficacy and the combination of paclitaxel and vorinostat significantly inhibited the tumor growth. Taken together, dual drug-loaded Tf receptor-targeted nanomedicine holds great potential in chemotherapy of solid tumors.

Engineering of cell microenvironment-responsive polypeptide nanovehicle co-encapsulating a synergistic combination of small molecules for effective chemotherapy in solid tumors

In this study, we report a facile method to construct a bioactive (poly(phenylalanine)-b-poly(l-histidine)-b-poly(ethylene glycol) polypeptide nanoconstruct to co-load doxorubicin (DOX) and quercetin (QUR) (DQ-NV). The smart pH-sensitive nanovehicle was fabricated with precisely tailored drug-to-carrier ratio that resulted in accelerated, sequential drug release. As a result of ratiometric loading, QUR could significantly enhance the cytotoxic potential of DOX, induced marked cell apoptosis; change cell cycle patterns, inhibit the migratory capacity of sensitive and resistant cancer cells. In particular, pro-oxidant QUR from DQ-NV remarkably reduced the GSH/GSSG ratio, indicating high oxidative stress and damage to cellular components. DQ-NV induced tumor shrinkage more effectively than the single drugs in mice carrying subcutaneous SCC-7 xenografts. DQ-NV consistently induced high expression of caspase-3 and PARP and low expression of Ki67 and CD31 immunomarkers. In summary, we demonstrate the development of a robust polypeptide-based intracellular nanovehicle for synergistic delivery of DOX/QUR in cancer chemotherapy.

STATEMENT OF SIGNIFICANCE

In this study, we report a facile method to construct bioactive and biodegradable polypeptide nanovehicles as an advanced platform technology for application in cancer therapy. We designed a robust (poly(phenylalanine)-b-poly(l-histidine)-b-poly(ethylene glycol) nanoconstruct to co-load doxorubicin (DOX) and quercetin (QUR) (DQ-NV). The conformational changes of the histidine block at tumor pH resulted in accelerated, sequential drug release. QUR could significantly enhance the cytotoxic potential of DOX, induce marked cell apoptosis, change cell cycle patterns, and inhibit the migratory capacity of sensitive and resistant cancer cells. DQ-NV induced tumor shrinkage more effectively than the single drugs and the 2-drug cocktail in tumor xenografts. In summary, we demonstrate the development of an intracellular nanovehicle for synergistic delivery of DOX/QUR in cancer chemotherapy.

Bioflavonoid Fisetin Loaded α-Tocopherol-Poly(lactic acid)-Based Polymeric Micelles for Enhanced Anticancer Efficacy in Breast Cancers

PURPOSE

In this study, tocopherol based polymeric micelles were successfully prepared to enhance the anticancer effect of fisetin (FIS) in breast cancer cells.

METHODS

The drug-loaded carrier was characterized in terms of physicochemical and in vivo parameters.

RESULTS

Compared to FIS, FIS-TPN showed higher cellular uptake in MCF-7 breast cancer cells as revealed by CLSM and flow cytometry. The cytotoxicity assay results clearly showed that the free FIS and FIS-TPN exhibited a typical dose-dependent toxic effect in MCF-7 breast cancer cells. Especially, enhanced cytotoxic effect of FIS was observed when loaded in a nanocarrier. Free FIS induced a ~11% apoptosis whereas FIS-TPN induced a significantly greater apoptosis of ~20% by the end of 24 h. At 48 h, similar trend continued and free FIS showed ~30% of apoptosis whereas ~42% cell apoptosis was observed in FIS-TPN treated group. Notably, migration of cancer cell was significantly inhibited when treated with FIS-TPN formulations. The FIS-TPN significantly reduced to tumor burden and H&E staining showed the lowest tumor volume and higher cell apoptosis.

CONCLUSIONS

All the findings suggest that the fisetin-loaded TPGS-PLA polymeric micelles serve as a potential candidate and promising alternative for the effective treatment of breast cancers.

Highly Stable PEGylated Poly(lactic-co-glycolic acid) (PLGA) Nanoparticles for the Effective Delivery of Docetaxel in Prostate Cancers

In the present study, a highly stable luteinizing-hormone-releasing hormone (LHRH)-conjugated PEGylated poly(lactic-co-glycolic acid) (PLGA) nanoparticles were developed for the successful treatment of prostate cancers. We have demonstrated that a unique combination of targeted drug delivery and controlled drug release is effective against prostate cancer therapy. The docetaxel (DTX)/PLGA-LHRH micelles possessed a uniform spherical shape with an average diameter of ~170 nm. The micelles exhibited a controlled drug release for up to 96 h which can minimize the non-specific systemic spread of toxic drugs during circulation while maximizing the efficiency of tumor-targeted drug delivery. The LHRH-conjugated micelles showed enhanced cellular uptake and exhibited significantly higher cytotoxicity against LNCaP cancer cells. We have showed that PLGA-LHRH induced greater caspase-3 activity indicating its superior apoptosis potential. Consistently, LHRH-conjugated micelles induced threefold and twofold higher G2/M phase arrest than compared to free DTX or PLGA NP-treated groups. Overall, results indicate that use of LHRH-conjugated nanocarriers may potentially be an effective nanocarrier to effectively treat prostate cancer.

Engineering of caveolae-specific self-micellizing anticancer lipid nanoparticles to enhance the chemotherapeutic efficacy of oxaliplatin in colorectal cancer cells

Novel nanomaterials for the intracellular transport of therapeutic cargos have been actively sought to effectively breach cell-membrane barriers. In this study we developed novel self-micellizing anticancer lipid (SMAL)-based pro-apoptotic nanoparticles (NPs) that enhance the accumulation and chemotherapeutic efficacy of oxaliplatin (OL) in colorectal cancer cells (CRCs). We demonstrated that NPs with special affinity to caveolae could be designed and based on this specificity, NPs effectively differentiated between endothelial cells (tumor cells) and epithelial cells, without the need for a cell-specific targeting moiety. We demonstrated a remarkable uptake of OL-loaded SMAL NPs (SMAL-OL) in HCT116 and HT-29 cells via the caveolae-mediated endocytosis (CvME) pathway. The higher accumulation of SMAL-OL in the intracellular environment resulted in a significantly elevated anticancer effect compared to that of free OL. Cell cycle analysis proved G2/M phase arrest, along with substantial presence of cells in the sub-G1 phase. An immunoblot analysis indicated an upregulation of pro-apoptotic markers (Bax; caspase-3; caspase-9; and PARP1) and downregulation of Bcl-xl and the PI3K/AKT/mTOR complex, indicating a possible intrinsic apoptotic signaling pathway. Overall, the ability of SMAL NPs to confer preferential specificity towards the cell surface domain could offer an exciting means of targeted delivery without the need for receptor-ligand-type strategies.

STATEMENT OF SIGNIFICANCE

In this work, we developed a novel self-micellizing anticancer lipid (SMAL)-based pro-apoptotic nanoparticles (NPs) that enhance the accumulation and chemotherapeutic efficacy of oxaliplatin (OL) in colorectal cancer cells. We demonstrated that NPs with special affinity to caveolae could be realized and based on this specificity, NPs effectively differentiated between endothelial cells (tumor cells) and epithelial cells, without the need for a cell-specific targeting moiety. In addition, oxaliplatin-loaded SMAL were efficiently endocytosed by the cancer cells and represent a significant breakthrough as an effective drug delivery system with promising potential in cancer therapy. We believe this work holds promising potential for the development of next generation of multifunctional nanocarriers for an exciting means of targeted delivery without the need for receptor-ligand-type strategies.

Gemcitabine-based polymer-drug conjugate for enhanced anticancer effect in colon cancer

In this study, we have demonstrated gemcitabine (GEM)-conjugated amphiphilic biodegradable polymeric drug carriers. Our aim was to increase the chemotherapeutic potential of GEM in colon cancer by forming a unique polymer-drug conjugates. The polymer-drug conjugate micelles were nanosized with a typical spherical shape. The GEM-conjugated methoxy poly(ethylene glycol)-poly(lactic acid) (GEM-PL) exhibited a controlled release of drug in both the pH conditions. The developed GEM-PL efficiently killed the HT29 cancers cells in a typical time dependent manner. The clonogenic assay further confirmed the superior anticancer effect of GEM-PL which showed least number of colonies. GEM-PL formulation exhibited a significantly higher apoptosis of cancer cells (∼25%) when stained using Annexin-V/PI kit. Conjugation of GEM to the mPEG-PLA significantly enhanced the blood circulation potential in animal model compared to that of free GEM. GEM-PL could prevent quick elimination of the drug and can provide sufficient time for the greater accumulation of GEM at the tumor sites. GEM-PL showed a remarkable tumor regression effect as evident from the lowest tumor volume in HT-29 containing tumor model. Overall, mPEG-PLA/GEM conjugates showed the potential of polymer-based drug targeting and might hold significant clinical potential in the treatment of colon cancers.

Development of polymeric irinotecan nanoparticles using a novel lactone preservation strategy

Irinotecan (IRT) is an important part of the first- and second-line regimen for metastatic colorectal and some other cancers. However, IRT suffers the constraints of pH-dependent conversion of active lactone form to inactive carboxylate form, burst release owing to its aqueous solubility, short half-life and dose-dependent side effects. In this study, we developed polymeric nanoparticles (NPs) that not only deliver IRT to tumor sites, but also overcome its drawbacks by preserving active lactone conformation, prolonging the plasma circulation time, and by providing sustained release. IRT complex was rendered hydrophobic by ion-pairing with anions (docusate sodium, sodium lauryl sulfate, and sodium tripolyphosphate), and loaded in PEG-PLGA NPs via water/oil/water double emulsification method. The NPs were spherical, ∼60nm, monodispersed, and had shell-core morphology. They retained >80% lactone form for more than 1 month of storage and exhibited sustained release characteristics. In addition, sub -100nm size of NPs offered elevated cellular internalization. Owing to the presence of hydrophilic PEG outer layer and drug-loaded hydrophobic PLGA core, NPs conferred excellent plasma stability and prolonged the retention time of IRT by more than 10-fold as compared to free IRT. Therefore, this system could provide an excellent platform for efficient and sustained delivery of IRT and similar labile drugs to the tumor site, while maintaining their chemical integrity.

Styrene maleic acid-encapsulated paclitaxel micelles: antitumor activity and toxicity studies following oral administration in a murine orthotopic colon cancer model

Oral administration of paclitaxel (PTX), a broad spectrum anticancer agent, is challenged by its low uptake due to its poor bioavailability, efflux through P-glycoprotein, and gastrointestinal toxicity. We synthesized PTX nanomicelles using poly(styrene-co-maleic acid) (SMA). Oral administration of SMA-PTX micelles doubled the maximum tolerated dose (60 mg/kg vs 30 mg/kg) compared to the commercially available PTX formulation (PTX [Ebewe]). In a murine orthotopic colon cancer model, oral administration of SMA-PTX micelles at doses 30 mg/kg and 60 mg/kg reduced tumor weight by 54% and 69%, respectively, as compared to the control group, while no significant reduction in tumor weight was observed with 30 mg/kg of PTX (Ebewe). In addition, toxicity of PTX was largely reduced by its encapsulation into SMA. Furthermore, examination of the tumors demonstrated a decrease in the number of blood vessels. Thus, oral delivery of SMA-PTX micelles may provide a safe and effective strategy for the treatment of colon cancer.

PEGylated lipid bilayer-supported mesoporous silica nanoparticle composite for synergistic co-delivery of axitinib and celastrol in multi-targeted cancer therapy

Small-molecule drug combination therapies are an attractive approach to enhancing cancer chemotherapeutic responses. Therefore, this study aimed to investigate the potential of axitinib (AXT) and celastrol (CST) in targeting angiogenesis and mitochondrial-based apoptosis in cancer. Therefore, we prepared AXT/CST-loaded combination nanoparticles (ACML) with CST loaded in the mesoporous silica nanoparticles (MSN) and AXT in PEGylated lipidic bilayers. We showed that ACML effectively inhibited angiogenesis and mitochondrial function and was efficiently internalized in SCC-7, BT-474, and SH-SY5Y cells. Furthermore, hypoxia-inducible factor (HIF)-1α expression, which increased under hypoxic conditions in all cell lines exposed to ACML, markedly decreased, which may be critical for tumor inhibition. Western blotting showed the superior anticancer effect of combination nanoparticles in different cancer cells. Compared to the cocktail (AXT/CST), ACML induced synergistic cancer cell apoptosis. The AXT/CST-based combination nanoparticle synergism might be mediated by AXT, which controls vascular endothelial growth factor receptors while CST acts on target cell mitochondria. Importantly, ACML-treated mice showed remarkably higher tumor inhibition (64%) than other groups did in tumor xenograft models. Tumor xenograft immunohistochemistry revealed elevated caspase-3 and poly (ADP-ribose) polymerase and reduced CD31 and Ki-67 expression, clearly suggesting tumor apoptosis through mitochondrial and antiangiogenic effects. Overall, our results indicate that ACML potentially inhibited cell proliferation and induced apoptosis by blocking mitochondrial function, leading to enhanced antitumor efficacy.

STATEMENT OF SIGNIFICANCE

In this research, we formulated an anticancer drug combination nanoparticle loaded with axitinib (AXT) in the lipidic bilayer of PEGylated liposomes and celastrol (CST) in mesoporous silica nanoparticles. The anticancer effects of the AXT/CST-loaded combination nanoparticle (ACML) were synergistic and superior to the other formulations and involved more efficient drug delivery to the tumor site with enhanced effects on angiogenesis and mitochondrial function. Therefore, our study demonstrated that the inhibition of cell proliferation and induction of apoptosis by ACML, which was mediated by blockade of mitochondrial function and anti-angiogenesis, led to enhanced antitumor efficacy, which may be potentially useful in the clinical treatment of cancer.

Transferrin-conjugated polymeric nanomedicine to enhance the anticancer efficacy of edelfosine in acute myeloid leukemia

In this study, transferrin (Tf)-conjugated polyethylene glycol (PEG)-poly-l-lysine (PLL)-poly(lactic-co-glycolic acid) (PLGA) (PEG-PLL-PLGA)-based micellar formulations were successfully prepared for the delivery of edelfosine (EDS) in leukemia treatment. The micelles were nanosized and presented spherical shaped particles. Our in vitro data suggest that the nanoformulations maintain the biological activity of drugs for longer periods and lead to a continuous release of active drug. The enhanced cellular uptake of EDS-TM resulted in significantly higher cytotoxic effect in K562 leukemia cells. Cell cycle analysis further demonstrated the significantly higher G2/M phase arrest of cancer cells. Immunoblot analysis clearly revealed the potential of EDS-TM in inducing apoptosis of cancer cells which could improve the anticancer efficacy in leukemia. Importantly, EDS-M and EDS-TM significantly prolonged the circulation profile of EDS throughout until 24h, indicating the potential of targeted nanoparticulate delivery system. The prolonged blood circulation potential of micellar formulations might improve the therapeutic potential of drug by increasing its bioavailability in the serum. It would be worthwhile evaluating the effects of the EDS-loaded micelles on cancer cells in vivo for clinical application.

Docetaxel-loaded multilayer nanoparticles with nanodroplets for cancer therapy

A mixture of docetaxel (DTX) and Solutol^® HS 15 (Solutol) transiently formed nanodroplets when it was suspended in an aqueous medium. However, nanodroplets that comprised DTX and Solutol showed a rapid precipitation of DTX because of their unstable characteristics in the aqueous medium. The incorporation of nanodroplets that comprised DTX and Solutol through vesicle fusion and subsequent stabilization was designed to prepare multilayer nanoparticles (NPs) with a DTX-loaded Solutol nanodroplet (as template NPs) core for an efficient delivery of DTX as a chemotherapeutic drug. As a result, the DTX-loaded Solutol nanodroplets (~11.7 nm) were observed to have an increased average diameter (from 11.7 nm to 156.1 nm) and a good stability of the hydrated NPs without precipitation of DTX by vesicle fusion and multilayered structure, respectively. Also, a long circulation of the multilayer NPs was observed, and this was due to the presence of Pluronic F-68 on the surface of the multilayer NPs. This led to an improved antitumor efficacy based on the enhanced permeation and retention effect. Therefore, this study indicated that the multilayer NPs have a considerable potential as a drug delivery system with an enhanced therapeutic efficacy by blood circulation and with low side effects.

Polypyrrole coated PLGA core–shell nanoparticles for drug delivery and photothermal therapy

Core–shell PLGA@polypyrrole nanoparticls (PLGA@PPy NPS) were prepared for combination of photothermal therapy and chemotherapy.

Improved antitumor activity of epirubicin-loaded CXCR4-targeted polymeric nanoparticles in liver cancers

A liver-targeted drug delivery system (CX-EPNP) composed of PLGA/TPGS was prepared and characterized. The surface of nanoparticle was conjugated with LFC131 peptide to increase the specific interaction of carrier with CXCR4 overexpressing liver cancers to enhance the Epirubicin (EPI) delivery to tumors. The particles were nanosized with size than 150 nm and portrayed a sustained release kinetics suggesting its suitability for cancer targeting. The in vitro cell uptake results showed that the introduction of LFC131 to the nanoparticles could increase significantly the affinity to human hepatic carcinoma cells (HepG2) with approximately a 3-fold improvement in cellular uptake than non-targeted one. A specific receptor-mediated uptake was observed by confocal laser scanning microscopy. In addition, CX-EPNP showed remarkable cytotoxicity towards HepG2 cells, and could effectively inhibit tumor growth. The more significant EPI accumulation from CX-EPNP in the cancer cells gave rise to the enhanced EPI cytotoxicity and cell apoptosis. The CX-EPNP distributed mostly in the xenograft tumor after intravenous administration to mice and adequately remained in the blood for at least 24h. It seemed that CX-EPNP upon intravenous injection avoided rapid recognition by Kupffer cells and adequately remained in the blood. These findings suggest that CX-EPNP could effectively inhibit the growth of liver tumors in situ and could potentially reduce the systemic side effects. However, extensive investigation is still needed to assess the possible applications of the CX-EPNP in humans.