Mixed Polymeric Micelles Research Articles

Design and synthesis of mixed micellar system for enhanced anticancer efficacy of Paclitaxel through its co-delivery with Naringin

Emergence of multidrug resistance (MDR) has limited the success of chemotherapeutic agents. Reversal of drugs efflux systems through combination therapy has got wider attention for increasing anticancer drugs efficacy. This study aims at co-encapsulation of Paclitaxel with Naringin in mixed polymeric micelles for enhanced anticancer activity of the drug. Drug-loaded micelles were prepared using two different amphiphilic block co-polymers and were characterized for morphology, size, zeta potential, drug encapsulation, in vitro release and stability using atomic force microscope (AFM), zetasizer, UV spectrophotometer, and FT-IR. MTT assay and fluorescence microscopy were used for in vitro cytotoxicity and cellular uptake studies. Nano-size micelles with spherical morphology and negative charge encapsulated 76.52 ± 0.94% and 32.87 0.61% Paclitaxel and Naringin, respectively. The micelles were thermally stable and retained 87.05 ± 0.69% and 92.88 ± 2.17% Paclitaxel and Naringin upon one-month storage. Maximum drug release was achieved at fourth hour of the study for both the loaded drugs. Paclitaxel co-encapsulation with Naringin synergistically improved its intracellular uptake and 65% in vitro cytotoxicity against breast cancer cells was achieved at its lower dose of 15 µg/mL. Results suggest that co-encapsulation of Paclitaxel with Naringin in mixed micelles is an effective strategy for achieving its higher anticancer activity.

Glutathione Triggered Near Infrared Fluorescence Imaging-Guided Chemotherapy by Cyanine Conjugated Polypeptide.

Precise detection of the tumor environment for cancer diagnosis has been strongly demanded for further therapies. Here, a redox-responsive fluorescence switch off/on system PCQ was designed and synthesized conjugated with near-infrared (NIR) cyanine dyes (Cy5.5) and relevant quencher (FQ) in mixed polymeric micelles (PCy and PFQ). The mixed PCQ micelles were prepared with two kinds of polymers with poly(oligo (ethylene glycol) methacrylate) (POEGMA) as the hydrophilic shell, in which fluorescence emission was quenched by fluorescence resonance energy transfer (FRET) effect. The FQ was conjugated with POEGMA by disulfide linkage, which could be broken with a redox environment such as high glutathione (GSH) concentration in tumor cells. After the PCQ micelles got into tumor cells, PFQ blocks in PCQ would be disassembled to recompose PCy micelles. During that process, drugs like doxorubicin (DOX) could be loaded inside and formed PCQ@DOX nanoparticles and then released for accurate NIR bioimaging and drug delivery instantly.

In-vivo anti-diabetic and wound healing potential of chitosan/alginate/maltodextrin/pluronic-based mixed polymeric micelles: Curcumin therapeutic potential

Development of curcumin-loaded mixed polymeric micelles based on chitosan, alginate, maltodextrin, pluronic F127, pluronic P123, and tween 80, by thin-film hydration method has been investigated in Bisphenol A induced diabetics rats. Curcumin (C21H20O6) extracted from rhizomes of the “Curcuma longa” has attracted considerable attention of pharmaceutical researchers due to its low cost, excellent pharmacological activities and lesser side effects. Despite its diverse pharmacological properties, the therapeutic application of curcumin as an oral therapy has been limited due to its poor aqueous solubility, fixed chemical stability, and low bioavailability. In an attempt to overcome these limitations, we developed curcumin-loaded mixed polymeric micelles. Diabetes mellitus is a most common chronic carbohydrate metabolic disorder. The results clearly demonstrated the ability of developed formulation to reduce the elevated blood glucose level and lipid profile (total cholesterol, triglycerides). It maintained the body-weight, HDL cholesterol level, various biochemical parameters and accelerated the wound healing process when treated with these curcumin-based formulations. The treatment of curcumin loaded mixed polymeric formulations allowed a favorable inhibitory effect to these histopathological changes of liver, kidney, and pancreas. The newly developed curcumin-based formulations have proved superior therapeutic potential and excellent healing efficacy as compared to standard drugs and pure curcumin.

Preparation and Characterization of Spray-Dried Inhalable Powders Containing Polymeric Micelles for Pulmonary Delivery of Paclitaxel in Lung Cancer

Local delivery of chemotherapeutic drugs to the lungs offers many advantages for lung cancer treatment compared to conventional systemic chemotherapy. In the present study, novel mixed polymeric micelles based on tocopheryl succinate-polyethylene glycol 1000 and 5000 Da (TPGS1K and TPGS5K) were synthesized and loaded with paclitaxel (PTX). Then, the optimized micelles were incorporated as colloidal drug delivery system into lactose carrier particles using a spray drying technique. The mixed micelles of TPGS5K and TPGS1K in different molar ratios (10:0, 7:3, 5:5, 3:7, 0:10) were prepared and physicochemical properties including: particle size, zeta potential, critical micelle concentration (CMC), drug loading, drug release rate, and in vitro cytotoxicitywere investigated in details. The optimized nanoparticles were co-spray dried with lactose carriers to produce the spherical particle morphology of the inhalable particles. Particle sizes and zeta potentials of the different formulations varied in the range of 102 to 196 nm and -9.4 to -13.8 mV, respectively. The lowest CMC values were calculated for 5:5 and 7:3 combinations (16.33 and 17.89 µM, respectively). The drug release rate from different formulations were very slow and only 30% of the drug was released during 72 h. Cytotoxicity assay demonstrated increased cytotoxic activity of PTX-loaded mixed micelles compared to the free drug. The in vitro deposition data indicated that spray drying of PTX-loaded micelles with lactose resulted in the production of inhalable powders with the high fine particle fraction (60%). These results demonstrate that this novel PTX-loaded micelles embedded in dry powder inhalation aerosol platform has a great potential to be used in lung cancer treatment.

Pluronic-Based Mixed Polymeric Micelles Enhance the Therapeutic Potential of Curcumin.

Curcumin is a naturally occurring constituent of turmeric that is a good substitute for synthetic medicines for the treatment of different diseases, due to its comparatively safer profile. However, there are certain shortcomings that limit its use as an ideal therapeutic agent. In order to overcome these drawbacks, we prepared novel curcumin-loaded mixed polymeric micelles using different biocompatible polymers by the thin-film hydration method. We investigated the critical micelle concentration and temperature, drug loading and encapsulation efficiency, and minimum inhibitory concentration by spectrophotometry. Surface morphology, stability, particle size, drug-polymer interaction, and physical state of the prepared formulations were investigated using scanning electron microscopy, zeta potential, particle size analyzer, Fourier-transform infrared spectroscopy, and X-ray diffraction, respectively. The drug loading and entrapment efficiency were significantly increased (P < 0.01) when curcumin was encapsulated with pluronic-based mixed polymeric micelles as compared to that of pluronic-based micelles alone. In vitro studies exhibited that pluronic-based mixed polymeric micelles significantly increased anticancer (P < 0.01), antimicrobial (P < 0.001), antioxidant (P < 0.001), and α-amylase inhibitory (P < 0.001) activities when compared to pure curcumin and/or pluronic-based micelles alone. These findings suggest that the formation of mixed polymeric micelles increases the stability and solubility of curcumin.

Formulation and evaluation of mixed polymeric micelles of quercetin for treatment of breast, ovarian, and multidrug resistant cancers.

BackgroundQuercetin (QCT), a naturally occurring flavonoid has a wide array of pharmacological properties such as anticancer, antioxidant and anti-inflammatory activities. QCT has low solubility in water and poor bioavailability, which limited its use as a therapeutic molecule. Polymeric micelles (PMs) is a novel drug delivery system having characteristics like smaller particle size, higher drug loading, sustained drug release, high stability, increased cellular uptake and improved therapeutic potential. In the present study, we have formulated and characterized mixed PMs (MPMs) containing QCT for increasing its anticancer potential.MethodsThe MPMs were prepared by thin film hydration method, and their physicochemical properties were characterized. The in vitro anticancer activity of the MPMs were tested in breast (MCF-7 and MDA-MB-231, epithelial and metastatic cancer cell lines, respectively), and ovarian (SKOV-3 and NCI/ADR, epithelial and multi-drug resistant cell lines, respectively) cancer.ResultsThe optimal MPM formulations were obtained from Pluronic polymers, P123 and P407 with molar ratio of 7:3 (A16); and P123, P407 and TPGS in the molar ratio of 7:2:1 (A22). The size of the particles before lyophilization (24.83±0.44 nm) and after lyophilisation (37.10±4.23 nm), drug loading (8.75±0.41%), and encapsulation efficiency (87.48±4.15%) for formulation A16 were determined. For formulation A22, the particle size before lyophilization, after lyophilization, drug loading and encapsulation efficiency were 26.37±2.19 nm, 45.88±13.80 nm, 9.01±0.11% and 90.07±1.09%, respectively. The MPMs exhibited sustained release of QCT compared to free QCT as demonstrated from in vitro release experiments. The solubility of QCT was markedly improved compared to pure QCT. The MPMs were highly stable in aqueous media as demonstrated by their low critical micelle concentration. The concentration which inhibited 50% growth (IC50) values of both micellar preparations in all the cancer cell lines were significantly less compared to free QCT.ConclusionBoth the MPMs containing QCT could be used for effective delivery to different type of cancer and may be considered for further development.

MPEG5k- b-PLGA2k/PCL3.4k/MCT Mixed Micelles as Carriers of Disulfiram for Improving Plasma Stability and Antitumor Effect in Vivo.

The clinical application of disulfiram (DSF) in cancer treatments is hindered by its rapid degradation in the blood circulation. In this study, methoxy poly(ethylene glycol)- b-poly(lactide- co-glycolide)/poly(ε-caprolactone) (mPEG5k- b-PLGA2k/PCL3.4k) micelles were developed for encapsulation of DSF by using the emulsification-solvent diffusion method. Medium chain triglyceride (MCT) was incorporated into the mixed polymeric micelles to improve drug loading by reducing the core crystallinity. Differential scanning calorimetry (DSC) results implied that DSF is likely present in an amorphous form within the micelles, and is well dispersed. DSF is encapsulated within the core and the reservoir is stabilized by the hydrophilic shell to prevent rapid diffusion of DSF from the core. The DSF mixed micelles (DSF-MMs) showed good drug loading (5.90%) and a well-controlled particle size (86.4 ± 13.2 nm). The mixed micelles efficiently protected DSF from degradation in plasma, with 58% remaining after 48 h, while almost 90% of DSF was degraded after the same period for the DSF solution (DSF-sol), which was used as a control. The pharmacokinetics study showed that the maximum plasma concentration and bioavailability of DSF were improved by using the DSF-MMs (2 and 2.5 times that of the DSF-sol). The TIRs (tumor inhibition rates) of 5-FU, DSF-sol, and DSF-MMs were 63.46, 19.57, and 69.98%, respectively, implying that DSF-MMs slowed the growth of a H22 xenograft tumor model effectively.

Synthetic Polymeric Mixed Micelles Targeting Lymph Nodes Trigger Enhanced Cellular and Humoral Immune Responses.

It has been widely accepted that lymph nodes (LNs) are critical targets of cancer vaccines because antigen presentation and initiation of T-cell-mediated immune responses occur primarily at these locations. In this study, amphiphilic diblock copolymer poly(2-ethyl-2-oxazoline)-poly(d,l-lactide) (PEOz-PLA) combined with carboxylterminated-Pluronic F127 was used to construct mixed micelles [carboxylated-nanoparticles (NPs)] for codelivery of antigen ovalbumin (OVA) and Toll-like receptor-7 agonist CL264 (carboxylated-NPs/OVA/CL264) to the LN-resident dendritic cells (DCs). The results showed that the small, sub-60 nm size of the self-assembled mixed micelles enables them to rapidly penetrate into lymphatic vessels and reach draining lymph nodes after subcutaneous injection. Furthermore, the surface modification with carboxylic groups imparted the carboxylated-NPs with endocytic receptor-targeting ability, allowing for DC internalization of carboxylated-NPs/OVA/CL264 via the scavenger receptor-mediated pathway. Because stimulation of CL264 in early endosomes will lead to a more effective immune response than that in late endo/lysosomes, the mass ratio of PEOz-PLA to carboxylated-Pluronic F127 in the mixed micelles was adjusted to release the encapsulated CL264 to the early endosome, resulting in increased expression of costimulatory molecules and secretion of stimulated cytokines by DCs. Moreover, the incorporation of PEOz outside the micellar shell effectively augmented MHC I antigen presentation through facilitating endosome escape and cytosolic release of antigens. This in turn evoked potent immune responses in vivo, including activation of antigen-specific T-cell responses, production of antigen-specific IgG antibodies, and generation of cytotoxic T-lymphocyte responses. Finally, immunization with the codelivery system in E.G7-OVA tumor-bearing mice could not only significantly inhibit tumor growth but also markedly prolong the survival of tumor-bearing mice. Taken together, carboxylated-NPs/OVA/CL264 have demonstrated great potential for clinical applications as an effective antitumor vaccine for further immunotherapy.

Formulation and in vivo assessment of terconazole-loaded polymeric mixed micelles enriched with Cremophor EL as dual functioning mediator for augmenting physical stability and skin delivery

The aim of the current study was to formulate terconazole (TCZ) loaded polymeric mixed micelles (PMMs) incorporating Cremophor EL as a stabilizer and a penetration enhancer. A 23 full factorial design was performed using Design-Expert® software for the optimization of the PMMs which were formulated using Pluronic P123 and Pluronic F127 together with Cremophor EL. To confirm the role of Cremophor EL, PMMs formulation lacking Cremophor EL was prepared for the purpose of comparison. Results showed that the optimal PMMs formulation (F7, where the ratio of total Pluronics to drug was 40:1, the weight ratio of Pluronic P123 to Pluronic F127 was 4:1, and the percentage of Cremophor EL in aqueous phase was 5%) had a high micellar incorporation efficiency (92.98 ± 0.40%) and a very small micellar size (33.23 ± 8.00 nm). Transmission electron microscopy revealed that PMMs possess spherical shape and good dispersibility. The optimal PMMs exhibited superior physical stability when compared with the PMMs formulation of the same composition but lacking Cremophor EL. Ex vivo studies demonstrated that the optimal PMMs formula markedly improved the dermal TCZ delivery compared to PMMs lacking Cremophor EL and TCZ suspension. In addition, it was found that the optimal PMMs exhibited a greater extent of TCZ deposition in the rat dorsal skin relative to TCZ suspension. Moreover, histopathological studies revealed the safety of the optimal PMMs upon topical application to rats. Consequently, PMMs enriched with Cremophor EL, as a stable nano-system, could be promising for the skin delivery of TCZ.

Improved intestinal absorption of paclitaxel by mixed micelles self-assembled from vitamin E succinate-based amphiphilic polymers and their transcellular transport mechanism and intracellular trafficking routes

To ensure that antitumor drugs can be effectively transported across intestinal barrier and then quickly released in tumor cells, mixed polymeric micelles (Mix-PMs) were designed and fabricated by combining poly(2-ethyl-2-oxazoline)-vitamin E succinate (PEOz-VES) with TPGS1000 for enhancing intestinal absorption of paclitaxel. PEOz-VES exhibited an extremely low critical micelle concentration and negligible cytotoxicity. The Mix-PMs were characterized to have about 20 nm in diameter, uniform spherical morphology, high drug-loading content and sustained drug release profile with a retained pH-sensitivity. The results of the transport through Caco-2 cell monolayers and intestinal absorption revealed that Mix-PMs displayed higher transcellular transport efficiency compared with PEOz-VES micelles and Taxol®. The possible mechanism of transcellular transport for Mix-PMs was elucidated to be mainly through clathrin- and caveolae/lipid rafts-mediated transcytosis. Confocal laser scanning micrographs revealed that late endosomes, lysosomes, endoplasmic reticulum, Golgi apparatus, and mitochondria were all involved in intracellular trafficking of Mix-PMs. The proteins involved in transcytosis of Mix-PMs and finally excreted were unraveled for the first time by the analysis of proteins in the basolateral media according to the proteomics method. Consequently, the fabricated mixed polymeric micelles may have great potential in enhancing intestinal absorption and accelerating drug release in tumor cells.

Mixed polymeric micelles as a multifunctional visual thermosensor for the rapid analysis of mixed metal ions with Al3+ and Fe3+

A novel type of responsive mixed double hydrophilic block copolymer (DHBC)-based multifunctional visual thermosensor for the detection of Al3+ and Fe3+ was designed and synthesized based on reversible addition fragmentation chain transfer (RAFT) polymerization.

A novel mixed polymeric micelle for co-delivery of paclitaxel and retinoic acid and overcoming multidrug resistance: synthesis, characterization, cytotoxicity, and pharmacokinetic evaluation

In the current study, retinoic acid (RA) was conjugated to Pluronic F127 (PF127) through an esterification process. Mixed micelles were formed with tocopheryl polyethylene glycol 1000 (TPGS) for co-delivery of paclitaxel (PTX) and RA to the cancer cells. Mixed micelles of RA-PF127 and TPGS in different weight ratios (10:0, 7:3, 5:5, 3:7, 0:10 w/w) were prepared and physicochemical properties including, particle size, zeta potential, critical micelle concentration (CMC), drug loading content, entrapment efficiency, drug release, cellular uptake and in vitro cytotoxicity, were investigated in details. Furthermore, the pharmacokinetics of PTX-loaded optimized mixed micelles were evaluated in Sprague-Dawley rats and compared with Stragen® (PTX in Cremophor EL®). Particle sizes and zeta potentials of the drug-loaded micelles were in the range of 102.6–223.5 nm and −5.3 to −9.6 mV, respectively. The 7:3 and 5:5 micellar combinations had lower CMC values (0.034–0.042 mg/mL) than 0:10 (0.124 mg/mL). The entrapment efficiencies of 10:0, 7:3, and 5:5 were 53.4 ± 9.3%, 61.3 ± 0.5%, and 78.7 ± 1.66%, respectively. The release rates of PTX from 7:3 and 5:5 mixed micelles were significantly slower than other formulations. Cytotoxicity assay demonstrated increased cytotoxic activity of PTX-loaded mixed micelles compared to free PTX. The Vd and t1/2ß of PTX-loaded RA-PF127/TPGS (7:3) were increased by 2.61- and 1.27-fold, respectively, while the plasma area under the curve (AUC) of the micelles was 2.03-fold lower than those of Stragen®. Therefore, these novel mixed micelles could be effectively used for delivery of PTX and RA to the cancer cells. Moreover, TPGS as part of micelle composition could enhance the therapeutic effect of PTX and reduce side effects.

Curcumin-Loaded TPGS/F127/P123 Mixed Polymeric Micelles for Cervical Cancer Therapy: Formulation, Characterization, and InVitro and InVivo Evaluation.

Cervical cancer is the fourth most common cancer in women worldwide, and existing treatments cause severe side effects and great burdens. Thus, the development of safe, inexpensive therapeutic agents is necessary. Curcumin (Cur), a well-known natural product, exerts promising anti-cancer activities against various cancer types. However, its therapeutic efficacy is severely restrained due to rapid degradation, poor aqueous solubility, and low bioavailability. The objective of this study was to investigate the therapeutic potential of novel curcumin-loaded TPGS/F127/P123 mixed polymeric micelles (Cur@NPT100) for cervical cancer treatment. The Cur@NPT100 exhibited an average size of approximately 19 nm, a zeta potential of around -4 mV, a drug loading of 8.18 ± 0.36%, and an encapsulation efficiency of 79.38 ± 4.65%. Unlike free Cur, Cur@NPT100 are readily dispersed in aqueous medium, showing enhanced stability and a sustained release profile over a 6-day period. In vitro cell culture experiments revealed that TPGS/F127/P123 mixed polymeric micelles (NPT100) based nanocarriers substantially promoted the selective cellular uptake of Cur into HeLa cells rather than by non-cancerous NIH3T3 cells, inducing higher cytotoxicity and greater apoptosis and significantly increasing the percentage of cells arrested at the G2/M phase of the cell cycle. Additionally, the Cur@NPT100 facilitated more Cur accumulation in the mitochondria and decreased the mitochondrial membrane potential. In addition, western blot assays demonstrated that Cur@NPT100 were more potent than free Cur at activating the mitochondria-mediated apoptosis pathway. In vivo results further confirmed that Cur@NPT100 exhibited a much higher antitumor efficacy than free Cur and had excellent biocompatibility. In conclusion, Cur@NPT100 might be an effective therapeutic agent for cervical cancer.

Phage-derived protein-mediated targeted chemotherapy of pancreatic cancer

Pancreatic cancer has been a life-threatening illness associated with high incidence and mortality rates. Paclitaxel (PCT) that causes mitotic arrest in cancer cells disrupting microtubule function is used for pancreatic cancer treatment. Nausea, anorexia and abdominal pain are some of the typical dose-limiting toxicity associated gastrointestinal side effects of the drug. Here, we present the use of polymeric mixed micelles to enable a targeted delivery of PCT and to provide additional advantages such as enhanced drug solubility, bioavailability and minimal dose-limiting toxicity. Also, these micelles self-assemble with pancreatic cancer cells-specific phage proteins P38, L1 and with the hydrophobic drug PCT resolving the issue of complex chemistry efforts normally needed for any conjugation. Our cytotoxicity and binding experiment results in vitro in 2 D and 3 D models suggested that the phage protein-targeted drug-loaded micelles bind and exhibit higher cell killing over the non-targeted ones.

Preparation and Characterization of Mixed Polymeric Micelles as a Versatile Strategy for Meloxicam Oral Administration

Introduction: Currently, there are a significant number of drugs getting approval with poor biopharmaceutical characteristics, as low solubility and bioavailability. These facts lead to a decrease of the therapeutic effect and to an increase of the drug dosage. In this regard, there is a need to overcome this problem, in which the development of new drug delivery systems (DDS) arises as a promising strategy, since these systems could improve some drug characteristics, like solubility and dissolution rate, increasing their therapeutic effect with a lower dose. Therefore, the aim of this work consisted in the development and characterization of a new formulation of mixed polymeric micelles based on Pluronics® P123 and F68 to improve the administration of meloxicam (MLX). Methods: Firstly, polymeric micelles were prepared by the thin-film method. Secondly, it was performed the physicochemical characterization of the systems through the evaluation of their size, increment of solubility (IS) and encapsulation efficiency (EE) by DLS and UV spectroscopy, respectively. Besides this, it was also evaluated the morphology of the polymeric micelles by transmission electronic microscopy (TEM) and their chemical structure by FTIR spectroscopy and differential scanning calorimetry (DSC). Moreover, it was determined the physical stability of these systems and their cytotoxicity in vitro. Results: The obtained results show that the formulation FM2, (Pluronic P123 and MLX) and the formulation FM3, (Puronic P123 and F68 and MLX) have presented the better results for size, polydispersion index (PDI), IS and EE. Being, these results related to the capacity of these formulations to protect and to avoid the sequestration of MLX by the liver and spleen and, consequently, to improve the bioavailability of MLX. Besides this, these systems have the better results for the assay representing the physical stability in the passage for the gastrointestinal (GI) tract and they have a low toxicity for the cells, even at bigger concentrations. Conclusion: Thus, these formulations can be considered promising systems to improve the solubility of MLX and other poor soluble drugs in an oral administration. Keywords: Pluronic P123, pluronic F68, polymeric micelles, meloxicam, drug delivery systems, oral administration.

Physical and Pharmacokinetic Characterizations of trans-Resveratrol (t-Rev) Encapsulated with Self-Assembling Lecithin-based Mixed Polymeric Micelles (saLMPMs)

This study involved physical and pharmacokinetic characterizations of trans-resveratrol (t-Rev)-loaded saLMPMs which attempted to improve t-Rev’s pharmacokinetic profiles and bioavailability resolving hurdles limiting its potential health benefits. The optimal formulation consisted of t-Rev, lecithin, and Pluronic® P123 at 5:2:20 (t-Rev-loaded PP123 saLMPMs) provided mean particle size <200 nm, encapsulation efficiency >90%, and drug loading >15%. Compared to t-Rev solubilized with HP-β-CD, t-Rev-loaded PP123 saLMPMs enhanced t-Rev’s stability in PBS at RT, 4 °C, and 37 °C and in FBS at 37 °C, and retarded the in vitro release. Intravenous administration of t-Rev-loaded PP123 saLMPMs was able to enhance 40% absolute bioavailability and a greater portion of t-Rev was found to preferably distribute into peripheral compartment potentially establishing a therapeutic level at the targeted site. With oral administration, t-Rev-loaded LMPMs increases 2.17-fold absolute bioavailability and furnished a 3-h period of time in which the plasma concentration maintained above the desirable concentration for chemoprevention and accomplished a higher value of the dose-normalized area under the curve for potentially establishing an effective level at the target site. Therefore, intravenous and oral pharmacokinetic characteristics of t-Rev encapsulated with PP123 saLMPMs indicate that t-Rev can be translated into a clinically useful therapeutic agent.

Polymeric mixed micelles loaded mitoxantrone for overcoming multidrug resistance in breast cancer via photodynamic therapy.

Mitoxantrone (MIT) is an anticancer agent with photosensitive properties that is commonly used in various cancers. Multidrug resistance (MDR) effect has been an obstacle to using MIT for cancer therapy. Photochemical internalization, on account of photodynamic therapy, has been applied to improve the therapeutic effect of cancers with MDR effect. In this study, an MIT-poly(ε-caprolactone)-pluronic F68-poly(ε-caprolactone)/poly(d,l-lactide-co-glycolide)–poly(ethylene glycol)–poly(d,l-lactide-co-glycolide) (MIT-PFP/PPP) mixed micelles system was applied to reverse the effect of MDR in MCF-7/ADR cells via photochemical reaction when exposed to near-infrared light. MIT-PFP/PPP mixed micelles showed effective interaction with near-infrared light at the wavelength of 660 nm and exerted great cytotoxicity in MCF-7/ADR cells with irradiation. Furthermore, MIT-PFP/PPP mixed micelles could improve reactive oxygen species (ROS) levels, decrease P-glycoprotein activity, and increase the cellular uptake of drugs with improved intracellular drug concentrations, which induced cell apoptosis in MCF-7/ADR cells under irradiation, despite MDR effect, as indicated by the increased level of cleaved poly ADP-ribose polymerase. These findings suggested that MIT-PFP/PPP mixed micelles may become a promising strategy to effectively reverse the MDR effect via photodynamic therapy in breast cancer.

EGFR-Targeted Cationic Polymeric Mixed Micelles for Codelivery of Gemcitabine and miR-205 for Treating Advanced Pancreatic Cancer.

Gemcitabine (GEM), a first-line chemotherapy for pancreatic cancer undergoes rapid metabolism and develops chemoresistance after repeated administration. We previously demonstrated that the combination of GEM and miR-205 provides an effective therapeutic strategy to sensitize GEM-resistant pancreatic cancer cells. Since epidermal growth factor receptor (EGFR) is overexpressed in pancreatic cancer cells, in this study, we aimed to deliver mixed micelles containing GEM and miR-205 decorated with EGFR-targeting cetuximab (C225) monoclonal antibody for targeted therapy. Cetuximab C225 was conjugated to malemido-poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylene carbonate-graft-dodecanol (C225-PEG-PCD) to prepare mixed micelles with mPEG-b-PCC-g-GEM-g-DC-g-TEPA for targeted codelivery of GEM and miR-205. This mixed micelle formulation showed a significant enhancement in EGFR-mediated cellular uptake in GEM-resistant MIA PaCa-2R cells. Further, an enhanced tumor accumulation of C225-micelles conjugated with near-infrared fluorescent Cy7.5 dye and Dy677-labeled miR-205 in orthotopic pancreatic tumor bearing NSG mice was evident after systemic administration. In addition, inhibition of tumor growth was also observed with increased apoptosis and reduced EMT after treatment with C225-micelles containing GEM and miR-205. Therefore, we believe that the targeted delivery of GEM and miR-205 in combination could be a novel strategy for treating advanced pancreatic cancer.

Polysialic acid and pluronic F127 mixed polymeric micelles of docetaxel as new approach for enhanced antitumor efficacy

In our previous study, polysialic acid-octadecyl dimethyl betaine (PSA-BS18) was synthesized and modified to liposomal EPI. Preliminary experiments revealed that the PSA-BS18 was a potential material for targeting tumor site with superior curative effects. In this study, PSA-BS18 and Pluronic F127 (F127) mixed polymeric micelles encapsulated docetaxel (DTX) (FP/DTX) were prepared by a self-assembly method. The FP/DTX was found to have a diameter of 34.83 ± 0.50 nm with a narrow polydispersity, the entrapment efficiency was 99.12 ± 1.17%, and the drug loading efficiency of 1.40 ± 0.01%. The storage and dilution stability of FP/DTX was fine. In vitro release studies demonstrated that FP/DTX had delayed the drug release from the micelles. In vitro cytotoxicity assay on B16 cells presented that FP/DTX led to a stronger cytotoxic activity in comparison to F127 micelles based DTX (F127/DTX) and Tween80-based DTX (Taxotere®). The in vivo imaging study showed that the accumulation of FP/DTX at tumor sites was more than F127/DTX. The in vivo antitumor activity of FP/DTX against B16 tumor xenograft model showed a significant higher inhibition and a lower toxicity compared with F127/DTX and Taxotere®. Taken together, the results obtained above showed that PSA-BS18 and F127 mixed polymeric micelles may be a promising strategy for antitumor delivery of DTX.

Pluronic F127 and D-\u03b1-Tocopheryl Polyethylene Glycol Succinate (TPGS) Mixed Micelles for Targeting Drug Delivery across The Blood Brain Barrier

A novel polymeric mixed micelle composed of Pluronic F127 and D-α-tocopheryl polyethylene glycol succinate (TPGS) was developed to improve the delivery of fluorescent dyes and protein across the blood brain barrier (BBB). Rhodamine 123 (Rho123) and DiR loaded mixed micelles, composed of Pluronic F127 and TPGS with proportion of 4:1 (FT), were prepared by thin-film hydration, and β-galactosidase (β-Gal) loaded FT mixed micelles were prepared by self-assembly. The brain-targeted capability of FT mixed micelles were evaluated both in vitro and in vivo. The FT mixed micelles showed that a average particle size of 20.03 nm, and a low CMC of 0.0031% in water. The in vitro release of Rho123 from Rho123 loaded FT mixed micelles (FT/Rho123) presented a sustained-release property. FT/Rho123 also showed higher efficiency for the accumulation in brain capillary endothelial cells (BCECs) and brain tissues. β-Gal, a model protein, was also delivered and accumulated efficiently in the brain by spontaneous loading in the FT mixed micelles. Therefore, the results indicated that F127/TPGS mixed micelles may be considered as an effective nanocarrier for the brain-targeted delivery of diagnostic and therapeutic drugs.