Curcumin-loaded mixed micelles: preparation, optimization, physicochemical properties and cytotoxicityin vitro

Mirtazapine loaded polymeric micelles for rapid release tablet: A novel formulation-In vitro and in vivo studies

Major depression is a prevalent disorder characterized by sadness, lack of interest or pleasure, interrupted sleep or food, and impaired concentration. Mirtazapine (MTZ), a tetracyclic antidepressant drug, is commonly used to treat moderate to severe depression. MTZ is classified as a BCS class II drug that has shown bioavailability of 50% due to extensive first-pass metabolism. The aim of this research is to develop a delivery platform with enhanced solubility and oral bioavailability of MTZ through formulating polymeric micelles modeled in a rapid release tablet. Mirtazapine loaded polymeric micelles (MTZ-PMs) were formulated to enhance the solubility. Solutol® HS 15 and Brij 58 were used as combined surfactants in a ratio of (20:1) to MTZ in addition to Transcutol® P as a penetration enhancer. The following in vitro tests were performed: particle size, PDI, zeta potential, solubility factor, stability index, and transmission electron microscopes. Afterward, MTZ-PMs were converted to dry free flowable powder through loading on the adsorptive surface of Aerosil 200; then, the powder mixture was directly compressed (MTZ-PMs-RRT) into 13 mm tablets. MTZ-PMs-RRT was further investigated using in vitro evaluation tests of the tablets, namely, weight variation, thickness, diameter, hardness, friability, disintegration time, drug content, and in vitro dissolution test, which complied with the pharmacopeial limits. The pharmacokinetic parameters of MTZ-PMs-RRT compared to Remeron® tablet were further investigated in rabbits. The results showed enhanced solubility of MTZ with improved percentage relative bioavailability to 153%. The formulation of MTZ in the form of MTZ-PMs-RRT successfully improved the solubility, stability, and bioavailability of MTZ using a simple and scalable manufacturing process.

An active transport dual adaptive nanocarrier designed to overcome the corneal microenvironment for neovascularization therapy

The eyes have a complicated microenvironment with many clearance mechanisms, making it challenging for effective drug delivery to the targeted areas of the eyes. Substrate transport mediated by active transporters is an important way to change drug metabolism in the ocular microenvironment. We designed multifunctional, dual-adaptive nanomicelles (GSCQ@NTB) which could overcome multiple physiological barriers by acting on both the efflux transporter and influx transporter to achieve deep delivery of the P-gp substrate in the cornea. Specifically, an effective "triple" antiangiogenic agent, nintedanib (NTB), was loaded into the biocompatible micelles. The expression of the efflux transporter was reversed by grafting quercetin. The peptide (glycylsarcosine, GS) was modified to target the influx transporter "Peptide Transporter-1" (PepT-1). Quercetin (QRT) and nintedanib (NTB) were transported to the cornea cooperatively, achieving long retention on the ocular surface and high compatibility. In a New Zealand rabbit model, within 8 hours after local administration, GSCQ@NTB was enriched in corneal stromal neovascularization and effectively inhibited the progress of neovascularization. Its effectiveness is slightly better than that in the first-line clinical application of steroids. In this study, we introduce the preparation of a dual adaptive nano-micelle system, which may provide an effective non-invasive treatment for corneal neovascularization.

Recent Advances in Nanotechnology-Based Targeted Delivery Systems of Active Constituents in Natural Medicines for Cancer Treatment

Owing to high efficacy and safety, natural medicines have found their way into the field of cancer therapy over the past few decades. However, the effective ingredients of natural medicines have shortcomings of poor solubility and low bioavailability. Nanoparticles can not only solve the problems above but also have outstanding targeting ability. Targeting preparations can be classified into three levels, which are target tissues, cells, and organelles. On the premise of clarifying the therapeutic purpose of drugs, one or more targeting methods can be selected to achieve more accurate drug delivery and consequently to improve the anti-tumor effects of drugs and reduce toxicity and side effects. The aim of this review is to summarize the research status of natural medicines' nano-preparations in tumor-targeting therapies to provide some references for further accurate and effective cancer treatments.

Curcumin/Fusidic Acid Bitherapy Loaded Mixed Micellar Nanogel for Acne Vulgaris Treatment: In Vitro and In Vivo Studies

The combination of herbal drugs with a topical antibacterial for managing a chronic disease like acne vulgaris has emerged lately to settle side effects and bacterial multidrug resistance. Mixed micelles (MMs) incorporated into nanogel were explored for hybrid delivery of curcumin (Cur) and fusidic acid (FA) combination presenting a multi-strategic treatment. Curcumin-fusidic acid-loaded mixed micelles (Cur-FA-MMs) were assessed for size, surface charge, compatibility, in vitro release, and encapsulation. The selected formula was further loaded into nanogel and investigated for viscosity, ex vivo permeation, and in vivo potential. Cur-FA-MMs exhibited uniform nanosized spherical morphology, and negative surface charge affording high encapsulation for both drugs with a biphasic in vitro release over a period of 48h and good colloidal stability. The attained Cur-FA-MM-loaded nanogel had optimum viscosity with remarkable permeation coefficient values nearly 2-fold that related to plain nanogel. The pharmacodynamic effect of Cur on FA was pronounced by the significant improvement of the skin's degree of inflammation, epidermal hypertrophy, and congestion in animals treated with Cur-FA-MM-loaded nanogel. In conclusion, micellar nanogel could enable the progressive effect of Cur (an antioxidant with reported antibiotic activity) on FA (antibiotic) and decrease the risk of emerging antibiotic resistance by enhancing the solubility and permeation of Cur.

Self-Assembling Lecithin-Based Mixed Polymeric Micelles for Nose to Brain Delivery of Clozapine: In-vivo Assessment of Drug Efficacy via Radiobiological Evaluation

Purpose

The research objective is to design intranasal brain targeted CLZ loaded lecithin based polymeric micelles (CLZ- LbPM) aiming to improve central systemic CLZ bioavailability.

Methods

In our study, intranasal CLZ loaded lecithin based polymeric micelles (CLZ- LbPM) were formulated using soya phosphatidyl choline (SPC) and sodium deoxycholate (SDC) with different CLZ:SPC:SDC ratios via thin film hydration technique aiming to enhance drug solubility, bioavailability and nose to brain targeting efficiency. Optimization of the prepared CLZ-LbPM using Design-Expert® software was achieved showing that M6 which composed of (CLZ:SPC: SDC) in respective ratios of 1:3:10 was selected as the optimized formula. The optimized formula was subjected to further evaluation tests as, Differential Scanning Calorimetry (DSC), TEM, in vitro release profile, ex vivo intranasal permeation and in vivo biodistribution.

Results

The optimized formula with the highest desirability exhibiting (0.845), small particle size (12.23±4.76 nm), Zeta potential of (-38 mV), percent entrapment efficiency of > 90% and percent drug loading of 6.47%. Ex vivo permeation test showed flux value of 27 μg/cm².h and the enhancement ratio was about 3 when compared to the drug suspension, without any histological alteration. The radioiodinated clozapine ([¹³¹I] iodo-CLZ) and radioiodinated optimized formula ([¹³¹I] iodo-CLZ-LbPM) were formulated in an excellent radioiodination yield more than 95%. In vivo biodistribution studies of [¹³¹I] iodo-CLZ-LbPM showed higher brain uptake (7.8%± 0.1%ID/g) for intranasal administration with rapid onset of action (at 0.25 h) than the intravenous formula. Its pharmacokinetic behavior showed relative bioavailability, direct transport percentage from nose to brain and drug targeting efficiency of 170.59%, 83.42% and 117% respectively.

Conclusion

The intranasal self-assembling lecithin based mixed polymeric micelles could be an encouraging way for CLZ brain targeting.

Increased brain uptake of pterostilbene loaded folate modified micellar delivery system

Effective chemotherapy for clinical treatment of brain diseases is still lacking due to the poor penetration of the blood-brain barrier (BBB). The aim of this study was to construct a folate modified pterostilbene (Pt) loaded polymeric micellar delivery system (F-Pt/M) with mPEG-PCL as carrier material to aim at penetrating the BBB for brain tissue targeting via receptor-mediated endocytosis. In this study, F-Pt/M was prepared using thin-film hydration method and then optimized by response surface methodology (RSM) with the entrapment efficiency (EE), drug loading (DL) and hydrodynamic diameter (HD) as indexes. The average hydrodynamic diameter and zeta potential of optimal F-Pt/M were 133.2 nm and 24.6 mV, respectively. DL (18.3%) and EE (98.6%) made the solubility of Pt in water about 25 times higher than that of crude Pt. Results of DSC evaluation revealed that drugs were successfully encapsulated inside the polymeric micelles. TEM images showed that homogeneous spherical micellar structures with a narrow size distribution were developed. The release result in vitro showed that F-Pt/M presented sustained release behavior compared to control free Pt solution. Compared to non-targeted Pt/M, F-Pt/M had a significantly higher cytotoxicity against FR-overexpressing A172 cells. In vitro cellular uptake tests illustrated that the micellar delivery system could significantly improve the accumulation of drugs in target cells via receptor-mediated endocytosis. BBB penetration value (P) of F-Pt/M was about 4 folds higher than that of free Pt group. In addition, drug targeting index (DTI) was calculated to determine targeting of F-Pt/M to the brain which was found to be 4.89, implying improved brain targeting was achieved. Hence, the developed F-Pt/M exhibited great potential for delivering more drug molecules across the BBB for the treatment of brain diseases.

Enhancing the bioaccessibility of vitamin D using mixed micelles - An in vitro study

Vitamin-D deficiency is a global issue and a food fortification strategy may reduce deficiency levels. Mixed micelles (MM) are crucial to vitamin-D absorption in vivo and may enhance vitamin-D food fortification. This study compared the ability of MM based delivery systems to oil-in-water emulsions to improve vitamin-D bioaccessibility in vitro. Vitamin-D loaded emulsions were formed with olive or coconut oil alone or with added l-α-phosphatidylcholine, as well as two MM based systems. Particle size throughout digestion, fatty acid release, and vitamin-D bioaccessibility were measured. After digestion, particles in the MM size range (∼6-10 nm) were observed for emulsions but not for MM based systems. The bioaccessibility of vitamin-D in olive and coconut emulsions was 75% and 78%, respectively, and ∼ 90% with added l-α-phosphatidylcholine. Bioaccessibility for the MM alone was 93% and 90% when mixed with a protein/lactose base. Overall, MM show good potential as a delivery system for vitamin-D in vitro.

Advancements in redox-sensitive micelles as nanotheranostics: A new horizon in cancer management

World Health Organisation (WHO) delineated cancer as one of the foremost reasons for mortality with 10 million deaths in the year 2020. Early diagnosis and effective drug delivery are of utmost importance in cancer management. The entrapment of both bio-imaging dyes and drugs will open novel avenues in the area of tumor theranostics. Elevated levels of reactive oxygen species (ROS) and glutathione (GSH) are the characteristic features of the tumor microenvironment (TME). Researchers have taken advantage of these specific TME features in recent years to develop micelle-based theranostic nanosystems. This review focuses on the advantages of redox-sensitive micelles (RSMs) and supramolecular self-assemblies for tumor theranostics. Key chemical linkers employed for the tumor-specific release of the cargo have been discussed. In vitro characterisation techniques used for the characterization of RSMs have been deliberated. Potential bottlenecks that may present themselves in the bench-to-bedside translation of this technology and the regulatory considerations have been deliberated.

Hyaluronidase and pH Dual-Responsive Nanoparticles for Targeted Breast Cancer Stem Cells

pH-responsive and CD44 receptor-mediated targeted nanoparticles for eliminating cancer stem cells (CSCs) were developed based on complexes of PEG-poly(β-amino ester) (PEG-PBAE) micelles (PPM) coated with hyaluronic acid (HA) (HA-coated PPM complex, or HPPMc). Thioridazine (Thz) was loaded into HPPMc with a decent drug loading content. The release results of the drug in vitro showed that Thz was released from the HPPMc, which was stimulated by both the acidic pH and specific enzymes. Cytotoxicity studies on mammospheres (MS) revealed that the toxicity potential of Thz-loaded HPPMc (Thz–HPPMc) at pH 5.5 was better than drug solutions. Compared with that at pH 7.4, a higher cellular uptake of a coumarin-6 (C6)-labeled complex at pH 5.5 was observed, which demonstrated that complexes were efficiently taken up in MS. Meanwhile, free HA competitively inhibited the cellular uptake of HPPMc, which revealed that the uptake mechanism was CD44 receptor-mediated endocytosis. Within the acidic endolysosomal environment, the protonation of PBAE facilitated the escape of the complex from the lysosome and releases the drug. The results of in vivo distribution studies and tumor suppression experiments showed that HPMMc could stay in the tumor site of BALB/c nude mice for a longer period of time, and Thz–HPPMc could significantly improve the tumor-suppressing effect. All these results demonstrated the great potential of the multifunctional nanoparticle system for eliminating CSCs.

Use of Micellar Delivery Systems to Enhance Curcumin's Stability and Microbial Photoinactivation Capacity

Microbial photoinactivation using ultraviolet (UV) or visible light can be enhanced by photosensitizers. This study assessed the efficacy of encapsulating a food-grade photosensitizer (curcumin) in surfactant micelles on its water dispersibility, chemical stability, and antimicrobial activity. Stock curcumin-surfactant solutions were prepared with Surfynol 465 (S465) or Tween 80 (T80) (5 mM sodium citrate buffer). The antimicrobial activity of curcumin-loaded surfactant solutions was determined by monitoring the inactivation of Escherichia coli O157: H7 and Listeria innocua after 5-min irradiation with UV-A light (λ = 365 nm). The solutions mixed with the bacterial suspensions contained 1 µM curcumin and each surfactant below, near, and above their critical micelle concentrations (CMCs). The addition of surfactants at any level to the curcumin solution enhanced its dispersibility, stability, and efficacy as a photosensitizer, thereby enhancing its antimicrobial activity. Gram-positive bacteria were more susceptible than Gram-negative bacteria when curcumin-loaded micelles were used against them. The photoinactivation efficacy of curcumin-surfactant solutions depended on the pH of the solution (low > high), surfactant type (S465 > T80), and the amount of surfactant present (below CMC ≥ near CMC > above CMC = unencapsulated curcumin). This result suggests that excessive partitioning of curcumin into micelles reduced its ability to interact with microbial cells. Synergistic antimicrobial activity was observed when S465 was present below or near the CMC with curcumin at pH 3.5, which could be attributed to a more effective interaction of the photosensitizer with the cell membranes as supported by the fluorescence lifetime micrographs. The use of a micelle-based delivery system facilitates adsorption and generation of reactive oxygen species in the immediate environment of the microbial cell, enhancing photoinactivation.

Improving vitamin D3 stability to environmental and processing stresses using mixed micelles

Deficiency of vitamin-D is prevalent globally and can lead to negative health consequences. The fat-soluble nature of vitamin-D, coupled with its sensitivity to heat, light and oxygen limits its incorporation into foods. Mixed micelles (MM) have potential to enhance bioavailability of vitamin-D. This study explores the stability of MM to food processing regimes and their ability to protect vitamin-D. Subjecting MM to a range of shearing speeds (8,000-20,500 rpm) and to high pressure processing (600 MPa, 120sec) resulted in no change in MM size (4.1-4.5 nm). MM improved the retention of vitamin-D following exposure to UV-C light, near UV/visible light, and heat treatment. MM suspensions protected vitamin-D over a four week storage period at refrigeration or freezer conditions. Overall MM show potential to protect vitamin-D from degradation encountered in food processing and storage and may be beneficial as a mechanism to fortify foods with vitamin-D.

Targeting Cancer using Curcumin Encapsulated Vesicular Drug Delivery Systems

Curcumin is a major curcuminoid present in turmeric. The compound is attributed to various therapeutic properties, which include anti-oxidant, anti-inflammatory, anti-bacterial, anti-malarial, and neuroprotection. Due to its therapeutic potential, curcumin has been employed for centuries in treating different ailments. Curcumin has been investigated lately as a novel therapeutic agent in the treatment of cancer. However, the mechanisms by which curcumin exerts its cytotoxic effects on malignant cells are still not fully understood. One of the main limiting factors in the clinical use of curcumin is its poor bioavailability and rapid elimination. Advancements in drug delivery systems such as nanoparticle-based vesicular drug delivery platforms have improved several parameters, namely, drug bioavailability, solubility, stability, and controlled release properties. The use of curcumin-encapsulated niosomes to improve the physical and pharmacokinetic properties of curcumin is one such approach. This review provides an up-to-date summary of nanoparticle-based vesicular drug carriers and their therapeutic applications. Specifically, we focus on niosomes as novel drug delivery formulations and their potential in improving the delivery of challenging small molecules, including curcumin. Overall, the applications of such carriers will provide a new direction for novel pharmaceutical drug delivery, as well as for biotechnology, nutraceutical, and functional food industries.

Curcumin-loaded Pluronic® F-127 Micelles as a Drug Delivery System for Curcumin-mediated Photodynamic Therapy for Oral Application

Antimicrobial photodynamic therapy (aPDT) is promising for oral decontamination. Curcumin has been used as photosensitizer; however, the hydrophobic properties can negatively affect aPDT. This study evaluated the aPDT efficacy using Cur-loaded Pluronic^® F-127 micelles against Streptococcus mutans and Candida albicans biofilms. Micelles characterization was performed by zeta potential, dynamic light scattering, transmission electron microscopy, absorption and fluorescence spectroscopy. Cur concentrations, cell viability by CFU mL^-1 and confocal microscopy were determined. Data were analyzed by parametric and nonparametric tests under 5%. Cur-loaded Pluronic^® F-127 exhibited spherical shape, suitable particle size (≤100 nm), adequate polydispersity index, best stability, lower photodegradation and autoaggregation compared to unloaded-Cur. Both microorganisms were sensitive to Cur-loaded Pluronic^® F-127 micelles aPDT, with minimum inhibitory concentration (MIC) of 270 μm and 2.1093 μm for S. mutans and C. albicans suspended culture, respectively. Cur-loaded Pluronic^® F-127 aPDT exhibited antibacterial/antifungal effect against the biofilms (~3 log₁₀ reduction; P ≤ 0.05); however, similar to unloaded (P ≥ 0.05). Confocal images confirmed these results. Cur-loaded Pluronic^® F-127 micelles exhibited good photo-chemical properties and may be a viable alternative to deliver Cur and to improve aPDT effect during the treatment of dental caries. Moreover, Pluronic^® micelles can enhance the solubility, stability, permeability and control the release of Cur.

GE11 Peptide Conjugated Liposomes for EGFR-Targeted and Chemophotothermal Combined Anticancer Therapy

How to actively target tumor sites manipulating the controllable release of the encapsulated anticancer drugs and photosensitizers for synergistic anticancer therapy remains a big challenge. In this study, a cancer cell-targeted, near-infrared (NIR) light-triggered and anticancer drug loaded liposome system (LPs) was developed for synergistic cancer therapy. Photosensitizer indocyanine green (ICG) and chemotherapy drug Curcumin (CUR) were coencapsulated into the liposomes, followed by the surface conjugation of GE11 peptide for epidermal growth factor receptor (EGFR) targeting on the cancer cell surface. Strictly controlled by NIR light, GE11 peptide modified and CUR/ICG-loaded LPs (GE11-CUR/ICG-LPs) could introduce hyperthermia in EGFR overexpressed A549 cancer cells for photothermal therapy, which could also trigger the increased release of CUR for enhanced cancer cell inhibition. GE11-CUR/ICG-LPs synergized photochemotherapy could induce reactive oxygen species (ROS) generation and cytoskeleton disruption to activate stronger apoptotic signaling events than the photothermal therapy or chemotherapy alone by regulating Bax/Bcl-2 and PI3K/AKT pathways. This EGFR-targeted drug-delivery nanosystem with NIR sensitivity may potentially serve in more effective anticancer therapeutics with reduced off-target effects.

Black phosphorus nanosheets and docetaxel micelles co-incorporated thermoreversible hydrogel for combination chemo-photodynamic therapy

The platform of the combination chemo-photodynamic therapy has received widespread attention for enhancing anticancer efficacy and inhibiting tumor growth, which supports thermosensitive and controlled drug release. Here, an injectable thermoreversible hydrogel (BPNSs/DTX-M-hydrogel) co-encapsulating black phosphorus nanosheets (BPNSs) and docetaxel (DTX) micelles was prepared to increase drug accumulation in tumor tissue and improve anticancer efficacy. BPNSs were prepared by liquid exfoliation method with a simple and rapid preparation, and DTX micelles were prepared by the thin film dispersion method. Hydrogel was prepared with F127 as hydrogel matrix for intratumoral injection. BPNSs, DTX micelles, and BPNSs/DTX-M-hydrogel were characterized by particle size, morphology, stability and degradation, phase transition feature, and photodynamic performance. And the in vivo anticancer efficacy was evaluated in 4T1 tumor-bearing Balb/c mice. The results showed that the particle size of DTX micelles and BPNSs were about 16 and 180 nm, respectively. The hydrogel with the transformation temperature at near body exhibited great photodynamic efficacy and good biodegradability. Moreover, BPNSs/DTX-M-hydrogel with the combination of chemotherapy and photodynamic therapy exhibited unique anticancer efficacy with low toxicity. In conclusion, the combination platform of chemo-photodynamic therapy based on BPNSs could be a prospective strategy in antitumor research. Graphical abstract.

Enhancement of Simvastatin ex vivo Permeation from Mucoadhesive Buccal Films Loaded with Dual Drug Release Carriers

BACKGROUND

Simvastatin (SMV), a hypocholesterolemic agent, suffers from very low bioavailability due to its poor aqueous solubility and extensive first-pass metabolism.

METHODS

Two SMV carrier systems, namely, polymeric drug inclusion complex (IC) and mixed micelles (MM) nanoparticles, were developed and loaded into mucoadhesive buccal films to enhance SMV bioavailability. The two carrier systems were characterized and their permeation across human oral epithelial cells (OEC) was studied. The effect of IC to MM ratio (X1) and the mucoadhesive polymer concentration (X2) on the cumulative percent of drug released, elongation percent and the mucoadhesive strength, from the prepared mucoadhesive films, were optimized. Ex vivo permeation across bovine mucosal tissue was investigated. The permeation parameters for the in vitro and ex vivo release data were calculated.

RESULTS

Complexation of SMV with hydroxypropyl beta-cyclodextrin (HP β-CD) was superior to all other polymers as revealed by the equilibrium saturation solubility, stability constant, complexation efficiency and thermodynamic potential. SMV-HP β-CD IC was utilized to develop a saturated polymeric drug solution. Both carrier systems showed enhanced permeation across OEC when compared to pure drug. X1 and X2 were significantly affecting the characteristics of the prepared films. The optimized mucoadhesive buccal film formulation loaded with SMV IC and drug MM nanoparticles demonstrated superior ex vivo permeation when compared to the corresponding pure drug buccal film, and the calculated permeation parameters confirmed this finding.

CONCLUSION

Mucoadhesive buccal films containing SMV IC and drug MM can be used to improve drug bioavailability; however, additional pharmacokinetic and pharmacodynamic studies are required.

99mTc-radiolabeled Levofloxacin and micelles as infection and inflammation imaging agents

Easy and early detection of infection and inflammation is essential for early and effective treatment. In this study, PEGylated micelles were designed and both micelles and Levofloxacin were radiolabeled with 99mTcO4 - to develop potential radiotracers for detection of infection/inflammation. Radiolabeling efficiency, in vitro stability and bacterial binding of 99mTc-Levofloxacin and 99mTc-micelles were compared. The aim of this study is to formulate and compare 99mTc-Levofloxacin and 99mTc-micelles as infection and inflammation agents having different mechanisms for the accumulation at infection and inflammation site. PEGylated micelles were designed with a particle size of 80 ± 0.7 nm and proper characterization properties. High radiolabeling efficiency was achieved for 99mTc-Levofloxacin (96%) and 99mTc-micelles (87%). The radiolabeling efficiency was remained stable with some insignificant alterations for both radiotracers at 25 °C for 24 h. Although in vitro bacterial binding of 99mTc-levofloxacine was higher than 99mTc-micelles, 99mTc-micelles may also be evaluated potential agent due to long circulation and passive accumulation mechanisms at infection/inflammation site. Both radiopharmaceutical agents exhibit potential results in design, characterization, radiolabeling efficiency and in vitro bacterial binding point of view.

A Lipid Micellar System Loaded with Dexamethasone Palmitate Alleviates Rheumatoid Arthritis

Glucocorticoids have been confirmed to be effective in the treatment of a variety of inflammatory diseases. However, their application encounters limitations in terms of tissue distribution and bioavailability in vivo. To address these key issues, we designed and developed a nanopreparation by using egg yolk lecithin/sodium glycocholate (EYL/SGC) and utilize such mixed micelles (MMs) to encapsulate dexamethasone palmitate (DMP) for the treatment of rheumatoid arthritis (RA). The prepared DMP-MMs had an average particle size of 49.18 ± 0.43 nm and were compared with an emulsion-based dexamethasone palmitate. Pharmacokinetic and in vivo fluorescence imaging showed that mixed micelles had higher bioavailability and targeting efficiency in inflammatory sites. An arthritis rat model was established via induction by Complete Freund's Adjuvant (CFA), followed by the efficacy studies by the observations of paw volume, histology, spleen index, pro-inflammatory cytokines, and CT images. It was confirmed that intravenous injection of DMP-MMs exhibited advantages in alleviating joint inflammation compared with the emulsion system. Composed of pharmaceutical adjuvants only, the nanoscale mixed micelles seem a promising carrier system for the RA treatment with lipophilic drugs.

Superiority of TPGS-loaded micelles in the brain delivery of vinpocetine via administration of thermosensitive intranasal gel

Background: Vinpocetine (VPN) is a synthetic derivative of the Vinca minor alkaloids. The drug is characterized by a short half-life, limited water solubility and high hepatic first-pass effect. The objective was to develop different lipid-based nanocarriers (NCs) loaded into a thermosensitive in situ gelling (ISG) system to improve VPN bioavailability and brain targeting via intranasal (IN) delivery. Methods:  Different lipid-based NCs were developed and characterized for vesicle size, zeta potential, VPN entrapment efficiency (EE) and morphological characterization using transmission electron microscope (TEM). The prepared NCs were loaded into ISG formulations and characterized for their mucoadhesive properties. Ex-vivo permeation and histological study of the nasal mucosa were conducted. Pharmacokinetic and brain tissue distribution were investigated and compared to a marketed VPN product following administration of a single dose to rats. Results: VPN-D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) micelles nano-formulation showed the smallest particle size, highest EE among the studied NCs. TEM images revealed an almost spherical shape for all the prepared NCs. Among the NCs studied, VPN-loaded TPGS micelles demonstrated the highest percent cumulative VPN ex vivo permeation. All the prepared ISG formulations revealed the presence of mucoadhesive properties and showed no signs of inflammation or necrosis upon histological examination. Rats administered IN VPN-loaded TPGS-micelles ISG showed superior VPN concentration in the brain tissue and significant high relative bioavailability when compared to that received raw VPN-loaded ISG and marketed drug oral tablets. VPN-D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) micelles nano-formulation showed the smallest particle size, highest EE among the studied NCs. TEM images revealed an almost spherical shape for all the prepared NCs. Among the NCs studied, VPN-loaded TPGS micelles demonstrated the highest percent cumulative VPN ex vivo permeation. All the prepared ISG formulations revealed the presence of mucoadhesive properties and showed no signs of inflammation or necrosis upon histological examination. Rats administered IN VPN-loaded TPGS-micelles ISG showed superior VPN concentration in the brain tissue and significant high relative bioavailability when compared to that received raw VPN-loaded ISG and marketed drug oral tablets. Conclusion: VPN-loaded TPGS-micelles ISG formulation is a successful brain drug delivery system with enhanced bioavailability for drugs with poor bioavailability and those that are frequently administered.

Solutol HS15 based binary mixed micelles with penetration enhancers for augmented corneal delivery of sertaconazole nitrate: optimization, in vitro, ex vivo and in vivo characterization

Keratomycosis is a serious corneal disease that can cause a permanent visual disability if not treated effectively. Sertaconazole nitrate (STZ), a novel broad spectrum antifungal drug, was suggested as a promising treatment. However, its utility in the ocular route is restricted by its poor solubility, along with other problems facing the ocular delivery like short residence time, and the existing corneal barrier. Therefore, the objective of this study was to formulate STZ loaded binary mixed micelles (STZ-MMs) enriched with different penetration enhancers using thin-film hydration method, based on a 3¹.2² mixed factorial design. Different formulation variables were examined, namely, type of auxiliary surfactant, type of penetration enhancer, and total surfactants: drug ratio, and their effects on the solubility of STZ in MMs (S_M), particle size (PS), polydispersity index (PDI), and zeta potential (ZP) were evaluated. STZ-MMs enhanced STZ aqueous solubility up to 338.82-fold compared to free STZ. Two optimized formulations (MM-8 and MM-11) based on the desirability factor (0.891 and 0.866) were selected by Design expert^® software for further investigations. The optimized formulations were imaged by TEM which revealed nanosized spherical micelles. Moreover, they were examined for corneal mucoadhesion, stability upon dilution, storage effect, and ex vivo corneal permeation studies. Finally, both in vivo corneal uptake and in vivo corneal tolerance were investigated. MM-8 showed superiority in the ex vivo and in vivo permeation studies when compared to the STZ-suspension. The obtained results suggest that the aforementioned STZ loaded mixed micellar system could be an effective candidate for Keratomycosis-targeted therapy.

Hyaluronic Acid-Modified Micelles Encapsulating Gem-C12 and HNK for Glioblastoma Multiforme Chemotherapy

Glioblastoma multiforme (GBM), a prevalent brain cancer with high mortality, is resistant to the conventional single-agent chemotherapy. In this study, we employed a combination chemotherapy strategy to inhibit GBM growth and addressed its possible beneficial effects. The synergistic effect of lauroyl-gemcitabine (Gem-C₁₂) and honokiol (HNK) was first tested and optimized using U87 cells in vitro. Then, the hyaluronic acid-grafted micelles (HA-M), encapsulating the optimal mole ratio (1:1) of Gem-C₁₂ and HNK, were prepared and characterized. Cell-based studies demonstrated that HA-M could be transported into cells by a CD44 receptor-mediated endocytosis, which could penetrate deeper into tumor spheroids and enhance the cytotoxicity of payloads to glioma cells. In vivo, drug-loaded HA-M significantly increased the survival rate of mice bearing orthotopic xenograft GBM compared with the negative control (1.85-fold). Immunohistochemical analysis indicated that the enhanced efficacy of HA-M was attributed to the stronger inhibition of glioma proliferation and induction of apoptosis. Altogether, our findings showed advantages of combination chemotherapy of GBM using HA-grafted micelles.

High drug payload curcumin nanosuspensions stabilized by mPEG-DSPE and SPC: in vitro and in vivo evaluation

CONTEXT

Curcumin (CUR) is a promising drug candidate based on its broad bioactivities and good antitumor effect, but the application of CUR is potentially restricted because of its poor solubility and bioavailability.

OBJECTIVE

This study aims at developing a simple and effective drug delivery system for CUR to enhance its solubility and bioavailability thus to improve its antitumor efficacy.

MATERIALS AND METHODS

Curcumin nanosuspensions (CUR-NSps) were prepared by precipitation-ultrasonication method using mPEG2000-DSPE and soybean lecithin as a combined stabilizer.

RESULTS

CUR-NSps with a high drug payload of 67.07% were successfully prepared. The resultant CUR-NSps had a mean particle size of 186.33 ± 2.73 nm with a zeta potential of -19.00 ± 1.31 mV. In vitro cytotoxicity assay showed that CUR-NSps exhibited enhanced cytotoxicity compared to CUR solution. The pharmacokinetics results demonstrated that CUR-NSps exhibited a significantly greater AUC0-24 and prolonged MRT compared to CUR injections after intravenous administration. In the biodistribution study, CUR-NSps demonstrated enhanced biodistribution compared with CUR injections in liver, spleen, kidney, brain, and tumor. The CUR-NSps also showed improved antitumor therapeutic efficacy over the injections (70.34% versus 40.03%, p < 0.01).

CONCLUSIONS

These results suggest that CUR-NSps might represent a promising drug formulation for intravenous administration of CUR for the treatment of cancer.

Effective improvement of the neuroprotective activity after spinal cord injury by synergistic effect of glucocorticoid with biodegradable amphipathic nanomicelles

Dexamethasone acetate (DA) produces neuroprotective effects by inhibiting lipid peroxidation and inflammation by reducing cytokine release and expression. However, its clinical application is limited by its hydrophobicity, low biocompatibility and numerous side effects when using large dosage. Therefore, improving DA's water solubility, biocompatibility and reducing its side effects are important goals that will improve its clinical utility. The objective of this study is to use a biodegradable polymer as the delivery vehicle for DA to achieve the synergism between inhibiting lipid peroxidation and inflammation effects of the hydrophobic-loaded drugs and the amphipathic delivery vehicle. We successfully prepared DA-loaded polymeric micelles (DA/MPEG-PCL micelles) with monodispersed and approximately 25 nm in diameter, and released DA over an extended period in vitro. Additionally, in the hemisection spinal cord injury (SCI) model, DA micelles were more effective in promoting hindlimb functional recover, reducing glial scar and cyst formation in injured site, decreasing neuron lose and promoting axon regeneration. Therefore, our data suggest that DA/MPEG-PCL micelles have the potential to be applied clinically in SCI therapy.

d-α-Tocopheryl Succinate/Phosphatidyl Ethanolamine Conjugated Amphiphilic Polymer-Based Nanomicellar System for the Efficient Delivery of Curcumin and To Overcome Multiple Drug Resistance in Cancer

Nanomedicines have emerged as a promising treatment strategy for cancer. Multiple drug resistance due to overexpression of various drug efflux transporters and upregulation of apoptotic inhibitory pathways in cancer cells are major barriers that limit the success of chemotherapy. Here, we developed a d-α-tocopherol (α-TOS)/lipid-based copolymeric nanomicellar system (VPM) by conjugating phosphatidyl ethanolamine (PE) and α-TOS with poly(ethylene glycol) (PEG) via an amino acid linkage. The synthesized polymers were characterized by Fourier transform IR, gas-phase chromatography, and ¹H and ¹³C NMR spectroscopy. VPM exhibited mean hydrodynamic diameter of 141.0 ± 0.94 nm with low critical micelles concentrations (CMC) of 15 μM compared to plain PEG-PE micelles (PPM) with size of 23.9 ± 0.34 nm and CMC 20 μM. The bigger hydrophobic compartment in VPM resulted in improved loading of a potent chemotherapeutic drug, curcumin (Cur), and increased encapsulation efficiency (EE) (% drug loading 98.3 ± 1.92, and 85.3 ± 3.29; EE 14.8 ± 0.16 and 12.8 ± 0.09 for VPM and PPM, respectively). Curcumin loaded Vitamin E based micelles exhibited higher cytotoxicity compared to Curcumin loaded PEG-PE micelles in tested cancer cell lines. C-VPM demonstrated ∼3.2 and ∼2.7-fold higher ability to reverse multiple drug resistance compared to PPM and verapamil (concentration used 30 μM), respectively. In the in vivo study by using B16F10 implanted C57Bl6/J mice, C-VPM reduced the tumor volume and weight more efficiently than C-PPM by inducing apoptosis as analyzed by TUNEL assay on tumor cryosections. The newly developed polymeric micelles, VPM with improved drug loadability and ability to reverse the drug resistance could successfully be utilized as a nanocarrier system for hydrophobic chemotherapeutic agents for the treatment of drug-resistant solid tumors.

Zonisamide-loaded triblock copolymer nanomicelles as a novel drug delivery system for the treatment of acute spinal cord injury

Spinal cord injury (SCI) commonly leads to lifelong disability due to the limited regenerative capacity of the adult central nervous system. Nanomicelles can be used as therapeutic systems to provide effective treatments for SCI. In this study, a novel triblock monomethyl poly(ethylene glycol)-poly(l-lactide)-poly(trimethylene carbonate) copolymer was successfully synthesized. Next, polymeric nanomicelles loaded with zonisamide (ZNS), a Food and Drug Administration-approved antiepileptic drug, were prepared and characterized. The ZNS-loaded micelles (ZNS-M) were further utilized for the treatment of SCI in vitro and in vivo. The obtained ZNS-M were ~50 nm in diameter with good solubility and dispersibility. Additionally, these controlled-release micelles showed significant antioxidative and neuron-protective effects in vitro. Finally, our results indicated that ZNS-M treatment could promote motor function recovery and could increase neuron and axon density in a hemisection SCI model. In summary, these results may provide an experimental basis for the use of ZNS-M as a clinically applicable therapeutic drug for the treatment of SCI in the future.

Polymeric mixed micelles as nanomedicines: Achievements and perspectives

During the past few decades, polymeric micelles have raised special attention as novel nano-sized drug delivery systems for optimizing the treatment and diagnosis of numerous diseases. These nanocarriers exhibit several in vitro and in vivo advantages as well as increased stability and solubility to hydrophobic drugs. An interesting approach for optimizing these properties and overcoming some of their disadvantages is the combination of two or more polymers in order to assemble polymeric mixed micelles. This review article gives an overview on the current state of the art of several mixed micellar formulations as nanocarriers for drugs and imaging probes, evaluating their ongoing status (preclinical or clinical stage), with special emphasis on type of copolymers, physicochemical properties, in vivo progress achieved so far and toxicity profiles. Besides, the present article presents relevant research outcomes about polymeric mixed micelles as better drug delivery systems, when compared to polymeric pristine micelles. The reported data clearly illustrates the promise of these nanovehicles reaching clinical stages in the near future.

Development and Characterization of FLT3-Specific Curcumin-Loaded Polymeric Micelles as a Drug Delivery System for Treating FLT3-Overexpressing Leukemic Cells

This study aimed at developing a curcumin (CM) nanoparticle targeted to Feline McDonough Sarcoma (FMS)-like tyrosine kinase 3 (FLT3) protein on the surface of leukemic cells and at evaluating their properties, specificity, cytotoxicity, and inhibitory effect on FLT3 protein level in FLT3-overexpressing leukemic cells, EoL-1, and MV-4-11 cells. FLT3-specific peptides were conjugated onto modified poloxamer 407 using the copper-catalyzed azide-alkyne cycloaddition reaction. The thin film hydration method was performed for FLT3-specific CM-loaded polymeric micelles (FLT3-CM-micelles) preparation. Flow cytometry and fluorescence microscopy were used to determine rate of cellular uptake. 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to test the cytotoxicity of the micelles on leukemic cells. FLT3-CM-micelles demonstrated a mean particle size less than 50 nm, high entrapment efficiency, and high rate of CM uptake by leukemic cells. The intracellular CM fluorescence is related to FLT3 protein levels on the leukemic cell surfaces. Moreover, FLT3-CM-micelles demonstrated an excellent cytotoxic effect and decreased FLT3 protein expression in the leukemic cells. The FLT3-CM-micelles could enhance both solubility and cytotoxicity of CM on FLT3-overexpressing leukemic cells. These promising nanoparticles may be used for enhancing antileukemic activity of CM and developed as a targeted drug delivery system in the future.

Enhanced anticancer activity in vitro and in vivo of luteolin incorporated into long-circulating micelles based on DSPE-PEG2000 and TPGS

OBJECTIVES

This study aimed to evaluate enhanced anticancer activity in vitro and in vivo of luteolin-loaded long-circulating micelles (DTLLMs) formulated.

METHODS

DTLLM was the luteolin formulation prepared with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy-poly (ethylene glycol 2000) (DSPE-PEG2000 ) and d-α-tocopheryl polyethylene glycol succinate (TPGS) in this study. We performed a systematic comparative evaluation of the antiproliferative effect, cellular uptake, antitumour efficacy and in vivo tumour targeting of these micelles using non-small cell lung cancer (NSCLC) A549 cells.

KEY FINDINGS

Results showed that the obtained micelles have a mean particle size of around 42.34 nm, and the size of micelles was narrowly distributed. With the improved cellular uptake, DTLLM displayed a more potent antiproliferative action on A549 cell lines than luteolin; half-maximal inhibitory concentration (IC50 ) was 7.29 vs 19.14 μg/ml, respectively. The antitumour efficacy test in nude mice showed that DTLLM exhibited significantly higher antitumour activity against NSCLC with lesser toxic effects on normal tissues. The imaging study for in vivo targeting demonstrated that the long-circulating micelles formulation achieved targeted drug delivery and make drug release slow to prolong the circulating time.

CONCLUSION

DTLLM might be a potential antitumour formulation.

Optimization and anticancer activity in vitro and in vivo of baohuoside I incorporated into mixed micelles based on lecithin and Solutol HS 15

Baohuoside I, extracted from the Herba epimedii, is an effective but a poorly soluble antitumor drug. To improve its solubility, formulation of baohuoside I-loaded mixed micelles with lecithin and Solutol HS 15 (BLSM) has been performed in this study. We performed a systematic comparative evaluation of the antiproliferative effect, cellular uptake, antitumor efficacy, and in vivo tumor targeting of these micelles using non-small cell lung cancer (NSCLC) A549 cells. Results showed that the obtained micelles have a mean particle size of around 62.54 nm, and the size of micelles was narrowly distributed. With the improved cellular uptake, BLSM displayed a more potent antiproliferative action on A549 cell lines than baohuoside I; half-maximal inhibitory concentration (IC₅₀) was 6.31 versus 18.28 µg/mL, respectively. The antitumor efficacy test in nude mice showed that BLSM exhibited significantly higher antitumor activity against NSCLC with lesser toxic effects on normal tissues. The imaging study for in vivo targeting demonstrated that the mixed micelles formulation achieved effective and targeted drug delivery. Therefore, BLSM might be a potential antitumor formulation.