Hydrotropic oligomer-conjugated glycol chitosan as a carrier of paclitaxel: synthesis, characterization, and in vivo biodistribution

Chitosan Nanoparticles for Targeted Cancer Therapy: A Review of Stimuli-Responsive, Passive, and Active Targeting Strategies

Despite all major advancements in drug discovery and development in the pharmaceutical industry, cancer is still one of the most arduous challenges for the scientific community. The implications of nanotechnology have certainly resolved major issues related to conventional anticancer modalities; however, the undesired recognition of nanoparticles (NPs) by the mononuclear phagocyte system (MPS), their poor stability in biological fluids, premature release of payload, and low biocompatibility have restricted their clinical translation. In recent decades, chitosan (CS)-based nanodelivery systems (eg, polymeric NPs, micelles, liposomes, dendrimers, conjugates, solid lipid nanoparticles, etc.) have attained promising recognition from researchers for improving the pharmacokinetics and pharmacodynamics of chemotherapeutics. However, the specialty of this review is to mainly focus on and critically discuss the targeting potential of various CS-based NPs for treatment of different types of cancer. Based on their delivery mechanisms, we classified CS-based NPs into stimuli-responsive, passive, or active targeting nanosystems. Moreover, various functionalization strategies (eg, grafting with polyethylene glycol (PEG), hydrophobic substitution, tethering of stimuli-responsive linkers, and conjugation of targeting ligands) adapted to the architecture of CS-NPs for target-specific delivery of chemotherapeutics have also been considered. Nevertheless, CS-NPs based therapeutics hold great promise for improving therapeutic outcomes while mitigating the off-target effects of chemotherapeutics, a long-term safety profile and clinical testing in humans are warranted for their successful clinical translation.

Anti-depressant effect of Naringenin-loaded hybridized nanoparticles in diabetic rats via PPARγ/NLRP3 pathway

Naringenin (NAR) has various biological activities but low bioavailability. The current study examines the effect of Naringenin-loaded hybridized nanoparticles (NAR-HNPs) and NAR on depression induced by streptozotocin (STZ) in rats. NAR-HNPs formula with the highest in vitro NAR released profile, lowest polydispersity index value (0.21 ± 0.02), highest entrapment efficiency (98.7 ± 2.01%), as well as an acceptable particle size and zeta potential of 415.2 ± 9.54 nm and 52.8 ± 1.04 mV, respectively, was considered the optimum formulation. It was characterized by differential scanning calorimetry, examined using a transmission electron microscope, and a stability study was conducted at different temperatures to monitor its stability efficiency showing that NAR-HNP formulation maintains stability at 4 °C. The selected formulation was subjected to an acute toxicological test, a pharmacokinetic analysis, and a Diabetes mellitus (DM) experimental model. STZ (50 mg/kg) given as a single i.p. rendered rats diabetic. Diabetic rat groups were allocated into 4 groups: one group received no treatment, while the remaining three received oral doses of unloaded HNPs, NAR (50 mg/kg), NAR-HNPs (50 mg/kg) and NAR (50 mg/kg) + peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist, GW9662 (1mg/kg, i.p.) for three weeks. Additional four non-diabetic rat groups received: distilled water (normal), free NAR, and NAR-HNPs, respectively for three weeks. NAR and NAR-HNPs reduced immobility time in forced swimming test and serum blood glucose while increasing serum insulin level. They also reduced cortical and hippocampal 5-hydroxyindoeacetic acid, 3,4-Dihydroxy-phenylacetic acid, malondialdehyde, NLR family pyrin domain containing-3 (NLRP3) and interleukin-1beta content while raised serotonin, nor-epinephrine, dopamine and glutathione level. PPAR-γ gene expression was elevated too. So, NAR and NAR-HNPs reduced DM-induced depression by influencing brain neurotransmitters and exhibiting anti-oxidant and anti-inflammatory effects through the activation PPAR-γ/ NLRP3 pathway. NAR-HNPs showed the best pharmacokinetic and therapeutic results.

Recent Progress in Nanomaterial-Based Biosensors and Theranostic Nanomedicine for Bladder Cancer

Bladder cancer (BCa) is one of the most expensive and common malignancies in the urinary system due to its high progression and recurrence rate. Although there are various methods, including cystoscopy, biopsy, and cytology, that have become the standard diagnosis methods for BCa, their intrinsic invasive and inaccurate properties need to be overcome. The novel urine cancer biomarkers are assisted by nanomaterials-based biosensors, such as field-effect transistors (FETs) with high sensitivity and specificity, which may provide solutions to these problems. In addition, nanomaterials can be applied for the advancement of next-generation optical imaging techniques and the contrast agents of conventional techniques; for example, magnetic resonance imaging (MRI) for the diagnosis of BCa. Regarding BCa therapy, nanocarriers, including mucoadhesive nanoparticles and other polymeric nanoparticles, successfully overcome the disadvantages of conventional intravesical instillation and improve the efficacy and safety of intravesical chemotherapy for BCa. Aside from chemotherapy, nanomedicine-based novel therapies, including photodynamic therapy (PDT), photothermal therapy (PTT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), and combination therapy, have afforded us new ways to provide BC therapy and hope, which can be translated into the clinic. In addition, nanomotors and the nanomaterials-based solid tumor disassociation strategy provide new ideas for future research. Here, the advances in BCa diagnosis and therapy mentioned above are reviewed in this paper.

Hyaluronan Oligosaccharides-Coated Paclitaxel-Casein Nanoparticles with Enhanced Stability and Antitumor Activity

This study aims to develop specific-molecular-weight hyaluronic acid oligosaccharides-coated paclitaxel-loaded casein nanoparticles (HA-PT-Cas NPs) via chemical conjugation to increase the stability and antitumor effects. Optimized HA-PT-Cas NPs (HA/casein of 3:1) were obtained with a mean size of 235.3 nm and entrapment efficiency of 93.1%. HA-PT-Cas exhibited satisfactory stability at 4 °C for 12 days and 37 °C for 3 h; paclitaxel was retained at rates of 81.4% and 64.7%, respectively, significantly higher than those of PT-Cas (only 27.8% at 4 °C after 16 h and 20.3% at 37 °C after 3 h). HA-PT-Cas exhibited high efficiency (61.3%) in inhibiting A375 tumor owing to the enhanced stability of HA oligosaccharides barrier, which was comparable with that of 10 μg/mL cis-platinum (64.9%). Mice experiments showed the 74.6% tumor inhibition of HA-PT-Cas by intravenously administration, significantly higher than that of PT-casein (39.8%). Therefore, this work provides an effective carrier for drug delivery via HA oligomers-coated modification.

Evaluation and antitumor mechanism of functionalized chitosan-based polymeric micelles for oral delivery of paclitaxel

D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS)-modified carboxymethyl chitosan-rhein (TCR) polymeric micelles (PMs) self-assembled by TCR conjugate were constructed for oral delivery of paclitaxel (PTX). PTX-loaded TCR PMs with a drug loading capacity of 47.52 ± 1.65 % significantly improved the intestinal absorption and oral bioavailability of PTX. TCR PMs loaded with PTX displayed time- and concentration-dependent cytotoxicity in Caco-2, MCF-7 and Taxol-resistant MCF-7 (MCF-7/Taxol) cells. In MCF-7/Taxol cells, PTX-loaded TCR PMs promoted apoptosis and changed cell cycle, and TCR conjugate exhibited a P-gp inhibition ability and caused ATP depletion. Moreover, confocal imaging of intestinal sections, Caco-2 cell uptake assay and in vivo bioimaging using environmental response fluorescence probe suggested that TCR PMs loaded with drugs can be absorbed as a whole through the intestinal epithelium after oral administration, enter systemic circulation, and then get to the tumor site. Remarkably, PTX-loaded TCR PMs displayed a significant antitumor effect in H22 tumor xenograft mice and the MCF-7 or MCF-7/Taxol xenograft zebrafish model, which was related to the inhibitory function of TCR conjugate for P-gp activity and P-gp and MDR1 expression. Functionalized TCR PMs are expected to improve the oral therapeutic efficacy of poorly water-soluble antitumor drugs and treat drug-resistant tumors.

Formulation and Evaluation of Luteolin-Loaded Nanovesicles: In Vitro Physicochemical Characterization and Viability Assessment

Luteolin (LT) is a natural polyphenol water-insoluble compound. LT-loaded nanovesicles (NVs) were prepared by using the solvent evaporation method. LT-NVs were prepared using cholesterol, phosphatidylcholine, span 60, and labrasol in a different composition. The prepared LT-NVs were evaluated for encapsulation efficiency, in vitro drug release, and permeation study. The optimized LT-NVs were further evaluated for antioxidant activity and cytotoxicity using the lung cancer cell line. LT-NVs showed nanometric size (less than 300 nm), an optimum polydispersibility index (less than 0.5), and a negative zeta potential value. The formulations also showed significant variability in the encapsulation efficiency (69.44 ± 0.52 to 83.75 ± 0.35%) depending upon the formulation composition. The in vitro and permeation study results revealed enhanced drug release as well as permeation profile. The formulation LT-NVs (F2) showed the maximum drug release of 88.28 ± 1.13%, while pure LT showed only 20.1 ± 1.21% in 12 h. The release data revealed significant variation (p < 0.001) in the release pattern. The permeation results also depicted significant (p < 0.001) enhancement in the permeation across the membrane. The enhanced permeation from LT-NVs was achieved due to the enhanced solubility of LT in the presence of the surfactant. The antioxidant activity results proved that LT-NVs showed greater activity compared to pure LT. The cytotoxicity study showed lesser IC50 value from LT-NVs than the pure LT. Thus, it can be concluded that LT-NVs are a natural alternative to the synthetic drug in the treatment of lung cancer.

Tumor-Targeting Glycol Chitosan Nanoparticles for Cancer Heterogeneity

Nanomedicine is extensively employed for cancer treatment owing to its unique advantages over conventional drugs and imaging agents. This increased attention to nanomedicine, however, has not fully translated into clinical utilization and patient benefits due to issues associated with reticuloendothelial system clearance, tumor heterogeneity, and complexity of the tumor microenvironment. To address these challenges, efforts are being made to modify the design of nanomedicines, including optimization of their physiochemical properties, active targeting, and response to stimuli, but these studies are often performed independently. Combining favorable nanomedicine designs from individual studies may improve therapeutic outcomes, but, this is difficult to achieve as the effects of different designs are interconnected and often conflicting. Glycol chitosan nanoparticles (CNPs) are shown to accumulate in tumors, suggesting that this type of nanoparticle may constitute a good basis for the additional modification of nanoparticles. Here, multifunctional glycol CNPs designed to overcome multiple obstacles to their use are described and key factors influencing in vivo targeted delivery, targeting strategies, and interesting stimulus-responsive designs for improving cancer nanomedicine are discussed.

Formulation and Evaluation of Novel Hybridized Nanovesicles for Enhancing Buccal Delivery of Ciclopirox Olamine

Ciclopirox olamine (CPO) is a topical wide-spectrum antimycotic agent that possesses antifungal, antibacterial and anti-inflammatory activities. Loading CPO into a hybridized vesicular system is expected to enhance its buccal permeation and hence, therapeutic activity, whereas the frequent administration and side effects are reduced. Vesicular systems with high penetration ability were prepared based on cholesterol, Lipoid S45 or Phospholipon 90H, with span 60 while incorporating a penetration enhancer (Labrafac or labrasol) followed by full assessment of their size, entrapment efficiency, and drug release profiles. The optimum formulation, composed of Lipoid S45 and Labrafac, possessed the smallest vesicle size (346.1 nm), highest entrapment efficiency (94.4%), and sustained CPO release pattern, and was characterized for its morphology and thermal properties. This powerful mixture of the penetration enhancers (Lipoid S45 and Labrafac) in the designed hybridized vesicles was thoroughly investigated for their characteristics after being incorporated in bioadhesive gel. Moreover, enhanced antifungal activity was demonstrated either upon testing the designed formulation on agar plates or in vivo upon treating infected rabbits with the proposed formulation. Results suggest that the presented bioadhesive gel incorporating the CPO-loaded vesicles can be a promising delivery system that can offer a prolonged localized antifungal treatment with enhanced therapeutic effect.

Optical and Optoacoustic Imaging

The spatiotemporal determination of molecular events and cells is important for understanding disease processes, especially in oncology, and thus for the development of novel treatments. Equally important is the knowledge of the biodistribution, localization, and targeted accumulation of novel therapies as well as monitoring of tumor growth and therapeutic response. Optical imaging provides an ideal versatile platform for imaging of all these problems and questions.

Formulation and Characterization of α-Mangostin in Chitosan Nanoparticles Coated by Sodium Alginate, Sodium Silicate, and Polyethylene Glycol

Context:

α-mangostin, one of the xanthone derivative compounds isolated from Garcinia mangostana L. peel extract, has an excellent anticancer efficacy. However, α-mangostin has a lack of site specificity, poor cells selectivity, and low aqueous solubility. Polymeric nanoparticles formulation can be used to solve these problems.

Aim:

Therefore, the main aim of this study was to develop polymeric nanoparticles of α-mangostin-based chitosan (αM-Ch) coated by sodium alginate (αM-Ch/Al), sodium silicate (αM-Ch/Si), and polyethylene glycol 6000 (αM-Ch/PEG).

Materials and Methods:

Polymeric nanoparticles were prepared by ionic gelation method with the spray pyrolysis technique. Optimized formula was characterized by scanning electron microscopy, particle size, entrapment efficiency, drug loading, Fourier transform infrared, X-ray diffraction (XRD), and differential scanning calorimetry (DSC).

Results:

αM-Ch/Al, αM-Ch/Si, and αM-Ch/PEG Nanoparticles were successfully prepared with the range of particle size approximately 200–400nm. The XRD patterns and DSC thermograms of αM-Ch/Al showed an amorphous state, whereas αM-Ch/Si and αM-Ch/PEG indicated low crystalline forms. In addition, αM-Ch/Al had the highest entrapment efficiency (98.33% ± 0.06%) compared to αM-Ch/Si (70.46% ± 8.93%), and αM-Ch/PEG (92.24% ± 10.98%).

Conclusion:

These results suggest that αM-Ch/Al has the potential to enhance the physicochemical properties of α-mangostin for further formulation as an anticancer agent.

Glycol Chitosan: A Water-Soluble Polymer for Cell Imaging and Drug Delivery

Glycol chitosan (GC), a water-soluble chitosan derivative with hydrophilic ethylene glycol branches, has both hydrophobic segments for the encapsulation of various drugs and reactive functional groups for facile chemical modifications. Over the past two decades, a variety of molecules have been physically encapsulated within or chemically conjugated with GC and its derivatives to construct a wide range of functional biomaterials. This review summarizes the recent advances of GC-based materials in cell surface labeling, multimodal tumor imaging, and encapsulation and delivery of drugs (including chemotherapeutics, photosensitizers, nucleic acids, and antimicrobial agents) for combating cancers and microbial infections. Besides, different strategies for GC modifications are also highlighted with the aim to shed light on how to endow GC and its derivatives with desirable properties for therapeutic purposes. In addition, we discuss both the promises and challenges of the GC-derived biomaterials.

Current strategies for different paclitaxel-loaded Nano-delivery Systems towards therapeutic applications for ovarian carcinoma: A review article

Ovarian carcinoma (OC) is one of the leading causes of death among gynecologic malignancies all over the world. It is characterized by high mortality rate because of the lack of early diagnosis. The first-line chemotherapeutic regimen for late stage epithelial ovarian cancer is paclitaxel in combination to carboplatin. However, in most of cases, relapse occurs within six months despite the initial success of this chemotherapeutic combination. A lot of challenges have been encountered with the conventional delivery of paclitaxel in addition to the occurrence of severe off-target toxicity. One major problem is poor paclitaxel solubility which was improved by addition of Cremophor EL that unfortunately resulted in hypersensitivity side effects. Another obstacle is the multi drug resistance which is the main cause of OC recurrence. Accordingly, incorporation of paclitaxel, solely or in combination to other drugs, in nanocarrier systems has grabbed attention of many researchers to circumvent all these hurdles. The current review is the first article that provides a comprehensive overview on multi-faceted implementations of paclitaxel loaded nanoplatforms to solve delivery obstacles of paclitaxel in management of ovarian carcinoma. Moreover, challenges in physicochemical properties, biological activity and targeted delivery of PTX were depicted with corresponding solutions using nanotechnology. Different categories of nanocarriers employed were collected included lipid, protein, polymeric, solid nanoemulsion and hybrid systems. Future perspectives including imperative research considerations in ovarian cancer therapy were proposed as well.

In vitro and in vivo evaluation of a novel mitomycin nanomicelle delivery system

Mitomycin C (MMC), naturally synthesized by Streptomyces caespitosus, is a potent antineoplastic antibiotic for the treatment of various solid tumors. However, the defects of conventional MMC injections have greatly limited its clinical application due to its toxic side effects and non-specific interactions. To solve this problem, the PEG_2k-Fmoc-Ibuprofen (PEG-FIbu) micellar nanocarrier was synthesized and the MMC-loaded micelles (PEG-FIbu/MMC) were prepared by thin film hydration method and characterized. Ibuprofen was used as a hydrophobic domain of PEG-FIbu nanocarrier, and we expect it to synergize with codelivered MMC in the overall antitumor activity. The in vitro release of PEG-FIbu/MMC was examined by dialysis method using MMC injection as a control. Our data suggested that PEG-FIbu/MMC micelles presented appropriate particle size, low CMC value, good stability, high drug loading efficiency and sustained release properties. In vitro cytotoxicity studies with several tumor cell lines showed that the carrier was effective in mediating intracellular delivery of MMC to tumor cells. In vivo pharmacokinetics, tissue distribution and therapeutic study proved that PEG-FIbu/MMC micelles prolonged blood circulation, significantly improved the tumor accumulation and therapeutic efficacy, and reduced undesirable side effect on normal tissues compared to MMC injection. In general, PEG-FIbu/MMC micelles represented an effective strategy to improve the performance for the delivery of MMC and safety of medication.

The introduction of a micellar delivery system of MMC increase efficiency, reduce toxicity and enhance specific interactions in tumor.

Chitosan Based Self-Assembled Nanoparticles in Drug Delivery

Chitosan is a cationic polysaccharide that is usually obtained by alkaline deacetylation of chitin poly(N-acetylglucosamine). It is biocompatible, biodegradable, mucoadhesive, and non-toxic. These excellent biological properties make chitosan a good candidate for a platform in developing drug delivery systems having improved biodistribution, increased specificity and sensitivity, and reduced pharmacological toxicity. In particular, chitosan nanoparticles are found to be appropriate for non-invasive routes of drug administration: oral, nasal, pulmonary and ocular routes. These applications are facilitated by the absorption-enhancing effect of chitosan. Many procedures for obtaining chitosan nanoparticles have been proposed. Particularly, the introduction of hydrophobic moieties into chitosan molecules by grafting to generate a hydrophobic-hydrophilic balance promoting self-assembly is a current and appealing approach. The grafting agent can be a hydrophobic moiety forming micelles that can entrap lipophilic drugs or it can be the drug itself. Another suitable way to generate self-assembled chitosan nanoparticles is through the formation of polyelectrolyte complexes with polyanions. This paper reviews the main approaches for preparing chitosan nanoparticles by self-assembly through both procedures, and illustrates the state of the art of their application in drug delivery.

Paclitaxel and quercetin nanoparticles co-loaded in microspheres to prolong retention time for pulmonary drug delivery

High drug resistance, poor water solubility, short half-life, and low local drug concentration are obstacles for successful delivery of chemotherapeutic drugs for lung cancer. A new method involving the use of nanoparticles (NPs) for pulmonary delivery is proposed. However, use of NPs is limited by the particle size range for pulmonary drug delivery considering that NPs cannot be deposited directly into the lungs. NPs polymerized into microspheres (polymeric microspheres, PMs) will result in suitable particle sizes and retain the advantages of nanodrugs after redispersion when applied in pulmonary delivery. We report the development of novel NPs in the form of PMs loaded with paclitaxel (PTX) and quercetin (QUE) double drugs based on the synthesis of oleic acid-conjugated chitosan (OA-CTS) for pulmonary delivery. This approach is aimed toward prolonging PTX retention time in the presence of QUE and bypassing P-glycoprotein drug efflux pumps. NPs loaded with PTX or QUE were prepared with 11% substitution degree using OA-CTS as the carrier by ionic cross-linking method, which NPs loaded with PTX or QUE were used in the preparation of PMs by spray-drying. The diameters of the PMs ranged from 1 to 5 μm which had uniform size range. Scanning electron microscopy showed that PMs were polymers formed by a large number of NPs and readily redispersed (after redispersion, size of NPs ranged between 250 and 350 nm) in water within 1 h. PMs displayed slow-release characteristics at pH 4.5 and 7.4. The in vivo pharmacokinetic and biodistribution studies suggested that PMs exhibit prolonged circulation time and a markedly high accumulation in the lung. The obtained results indicate that PMs can serve as a promising pulmonary delivery system for combined pharmacotherapy using hydrophobic anticancer drugs.

Versatile Chemical Derivatizations to Design Glycol Chitosan-Based Drug Carriers

Glycol chitosan (GC) and its derivatives have been extensively investigated as safe and effective drug delivery carriers because of their unique physiochemical and biological properties. The reactive functional groups such as the amine and hydroxyl groups on the GC backbone allow for easy chemical modification with various chemical compounds (e.g., hydrophobic molecules, crosslinkers, and acid-sensitive and labile molecules), and the versatility in chemical modifications enables production of a wide range of GC-based drug carriers. This review summarizes the versatile chemical modification methods that can be used to design GC-based drug carriers and describes their recent applications in disease therapy.

Folate-targeted polymersomes loaded with both paclitaxel and doxorubicin for the combination chemotherapy of hepatocellular carcinoma

Combination chemotherapy is a promising method of improving cancer treatment, but the distinct pharmacokinetics of combined drugs and non-specific drug distribution slow down the development in the clinic. In this study, folate (FA) receptor-targeted polymersomes with apparent bilayered lamellar structure were successfully developed to co-encapsulate a hydrophobic-hydrophilic chemotherapeutic drug pair (PTX and DOX) in a single vesicle for enhancing the combination chemotherapeutic effect. Hydrophobic PTX was loaded into the thick hydrophobic lamellar membrane by the self-assembly of triblock copolymer PCL₈₀₀₀-PEG₈₀₀₀-PCL₈₀₀₀, while hydrophilic DOX was encapsulated into the hydrophilic reservoir using a trans-membrane ammonium sulfate gradient method. In vitro release study indicated that the drugs were released from the polymersomes in a controlled and sustained manner. Cellular uptake study indicated that FA-targeted Co-PS had higher internalization efficiency in FA receptor-overexpressing BEL-7404 cells than non-targeted Co-PS. In vitro cytotoxicity assay demonstrated that FA-targeted Co-PS exhibited less cytotoxic effect than free drug cocktail, but suppressed the growth of tumor cells more efficiently than non-targeted Co-PS. Ex vivo imaging biodistribution studies revealed that FA-targeted Co-PS led to highly efficient targeting and accumulation in the BEL-7404 xenograft tumor. Furthermore, the in vivo antitumor study showed that the combination chemotherapy of polymersomes to BEL-7404 tumor via intravenous injection was superior to free drug cocktail treatment, and the FA-targeted Co-PS exhibited significantly higher tumor growth inhibition than non-targeted Co-PS group. Therefore, the newly developed FA-targeted co-delivery polymersomes hold great promise for simultaneous delivery of multiple chemotherapeutics and would have great potential in tumor-targeting and combination chemotherapy.

STATEMENT OF SIGNIFICANCE

Combination chemotherapy is a promising method of improving cancer treatment, but the distinct pharmacokinetics of combined drugs and non-specific drug distribution slow down the development in the clinic. In our study, novel folate-targeted co-delivery polymersomes (Co-PS) were successfully developed to encapsulate a hydrophobic-hydrophilic chemotherapeutic drug pair (paclitaxel and doxorubicin) into the different compartments of the vesicle. In vivo studies revealed that the combination chemotherapy of polymersomes to BEL-7404 xenograft tumor via intravenous injection was superior to free drug cocktail treatment, and the FA-targeted Co-PS exhibited significantly higher tumor growth inhibition than non-targeted Co-PS group. Therefore, the newly developed FA-targeted co-delivery polymersomes hold great promise for simultaneous delivery of multiple chemotherapeutics and would have great potential in tumor-targeting and combination chemotherapy.

Self-assembled nanoparticles based on a cationic conjugated polymer/hyaluronan–cisplatin complex as a multifunctional platform for simultaneous tumor-targeting cell imaging and drug delivery

A multifunctional nanoparticle system based on a cationic conjugated polymer/hyaluronan–cisplatin complex for tumor-targeting cell imaging and drug delivery.

Hydrotropic polymer-based paclitaxel-loaded self-assembled nanoparticles: preparation and biological evaluation

Hydrotropic polymer-based paclitaxel-loaded self-assembled nanoparticles: preparation and biological evaluation.

Phospholipid complex enriched micelles: A novel drug delivery approach for promoting the antidiabetic effect of repaglinide

To enhance the oral antidiabetic effect of repaglinide (RG), a newly emerging approach, based on the combination of phospholipid complexation and micelle techniques, was employed. Repaglinide-phospholipid complex (RG-PLC) was prepared by the solvent-evaporation method then characterized using Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XPRD). The results revealed obvious disappearance of the characteristic peaks of the prepared RG-PLCs confirming the formation of drug-phospholipid complex. RG-PLC enriched micelles (RG-PLC-Ms) were prepared by the solvent-evaporation technique employing poloxamer 188 as surfactant. The prepared RG-PLC-Ms showed high drug encapsulation efficiencies (93.81-99.38%), with nanometric particle diameters (500.61-665.32nm) of monodisperse distribution and high stability (Zeta potential < -29.8mV). The in vitro release of RG from RG-PLC-Ms was pH-dependant according to the release media. A higher release pattern was reported in pH=1.2 compared to a more retarded release in pH=6.8 owing to two different kinetics of drug release. Oral antidiabetic effect of two optimized RG-PLC-M formulations was evaluated in an alloxan-induced diabetic rat model for 7-day treatment protocol. The two investigated formulations depicted normal blood glucose, serum malondialdehyde and insulin levels as well as an improved lipid profile, at the end of daily oral treatment, in contrast to RG marketed tablets implying enhanced antidiabetic effect of the drug. Hence, phospholipid-complex enriched micelles approach holds a promising potential for promoting the antidiabetic effect of RG.

Carbohydrate-based amphiphilic nano delivery systems for cancer therapy

Nanoparticles (NPs) are novel drug delivery systems that have been attracting more and more attention in recent years, and have been used for the treatment of cancer, infection, inflammation and other diseases. Among the numerous classes of materials employed for constructing NPs, organic polymers are outstanding due to the flexibility of design and synthesis and the ease of modification and functionalization. In particular, NP based amphiphilic polymers make a great contribution to the delivery of poorly-water soluble drugs. For example, natural, biocompatible and biodegradable products like polysaccharides are widely used as building blocks for the preparation of such drug delivery vehicles. This review will detail carbohydrate based amphiphilic polymeric systems for cancer therapy. Specifically, it focuses on the nature of the polymer employed for the preparation of targeted nanocarriers, the synthetic methods, as well as strategies for the application and evaluation of biological activity. Applications of the amphiphilic polymer systems include drug delivery, gene delivery, photosensitizer delivery, diagnostic imaging and specific ligand-assisted cellular uptake. As a result, a thorough understanding of the relationship between chemical structure and biological properties facilitate the optimal design and rational clinical application of the resulting carbohydrate based nano delivery systems for cancer therapy.

Multicomponent, peptide-targeted glycol chitosan nanoparticles containing ferrimagnetic iron oxide nanocubes for bladder cancer multimodal imaging

While current imaging modalities, such as magnetic resonance imaging (MRI), computed tomography, and positron emission tomography, play an important role in detecting tumors in the body, no single-modality imaging possesses all the functions needed for a complete diagnostic imaging, such as spatial resolution, signal sensitivity, and tissue penetration depth. For this reason, multimodal imaging strategies have become promising tools for advanced biomedical research and cancer diagnostics and therapeutics. In designing multimodal nanoparticles, the physicochemical properties of the nanoparticles should be engineered so that they successfully accumulate at the tumor site and minimize nonspecific uptake by other organs. Finely altering the nano-scale properties can dramatically change the biodistribution and tumor accumulation of nanoparticles in the body. In this study, we engineered multimodal nanoparticles for both MRI, by using ferrimagnetic nanocubes (NCs), and near infrared fluorescence imaging, by using cyanine 5.5 fluorescence molecules. We changed the physicochemical properties of glycol chitosan nanoparticles by conjugating bladder cancer-targeting peptides and loading many ferrimagnetic iron oxide NCs per glycol chitosan nanoparticle to improve MRI contrast. The 22 nm ferrimagnetic NCs were stabilized in physiological conditions by encapsulating them within modified chitosan nanoparticles. The multimodal nanoparticles were compared with in vivo MRI and near infrared fluorescent systems. We demonstrated significant and important changes in the biodistribution and tumor accumulation of nanoparticles with different physicochemical properties. Finally, we demonstrated that multimodal nanoparticles specifically visualize small tumors and show minimal accumulation in other organs. This work reveals the importance of finely modulating physicochemical properties in designing multimodal nanoparticles for bladder cancer imaging.

Doxorubicin-Loaded Nanobubbles Combined with Extracorporeal Shock Waves: Basis for a New Drug Delivery Tool in Anaplastic Thyroid Cancer

BACKGROUND

No standard chemotherapy is available for anaplastic thyroid cancer (ATC). Drug-loaded nanobubbles (NBs) are a promising innovative anticancer drug formulation, and combining them with an externally applied trigger may further control drug release at the target region. Extracorporeal shock waves (ESWs) are acoustic waves widely used in urology and orthopedics, with no side effects. The aim of the present work was to combine ESWs and new doxorubicin-loaded glycol chitosan NBs in order to target doxorubicin and enhance its antitumor effect in ATC cell lines.

METHODS

CAL-62 and 8305C cells were treated with empty NBs, fluorescent NBs, free doxorubicin, and doxorubicin-loaded NBs in the presence or in the absence of ESWs. NB entrance was evaluated by fluorescence microscopy and flow cytofluorimetry. Cell viability was assessed by Trypan Blue exclusion and WST-1 proliferation assays. Doxorubicin intracellular content was measured by high-performance liquid chromatography.

RESULTS

Treatment with empty NBs and ESWs, even in combination, was safe, as cell viability and growth were not affected. Loading NBs with doxorubicin and combining them with ESWs generated the highest cytotoxic effect, resulting in drug GI50 reduction of about 40%. Mechanistically, ESWs triggered intracellular drug release from NBs, resulting in the highest nuclear drug content.

CONCLUSIONS

Combined treatment with doxorubicin-loaded NBs and ESWs is a promising drug delivery tool for ATC treatment with the possibility of using lower doxorubicin doses and thus limiting its systemic side effects.

Neuronal Differentiation of Induced Pluripotent Stem Cells on Surfactant Templated Chitosan Hydrogels

The development of effective tissue engineering materials requires careful consideration of several properties beyond biocompatibility, including permeability and mechanical stiffness. While surfactant templating has been used for over a decade to control the physical properties of photopolymer materials, the potential benefit of this technique with regard to biomaterials has yet to be fully explored. Herein we demonstrate that surfactant templating can be used to tune the water uptake and compressive modulus of photo-cross-linked chitosan hydrogels. Interestingly, templating with quaternary ammonium surfactants also hedges against property fluctuations that occur with changing pH. Further, we demonstrate that, after adequate surfactant removal, these materials are nontoxic, support the attachment of induced pluripotent stem cells and facilitate stem cell differentiation to neuronal phenotypes. These results demonstrate the utility of surfactant templating for optimizing the properties of biomaterials intended for a variety of applications, including retinal regeneration.

Polysaccharide-based nanoparticles for theranostic nanomedicine

Polysaccharides are natural biological molecules that have numerous advantages for theranostics, the integrated approach of therapeutics and diagnostics. Their derivable reactive groups can be leveraged for functionalization with a nanoparticle-enabling conjugate, therapeutics (small molecules, proteins, peptides, photosensitizers) and/or diagnostic agents (imaging agents, sensors). In addition, polysaccharides are diverse in size and charge, biodegradable and abundant and show low toxicity in vivo. Polysaccharide-based nanoparticles are increasingly being used as platforms for simultaneous drug delivery and imaging and are therefore becoming popular theranostic nanoparticles. The review focuses on the method of nanoparticle formation (self-assembled, physical or chemical cross-linked) when engineering polysaccharide-based nanoparticles for theranostic nanomedicine. We highlight recent examples of polysaccharide-based theranostic systems from literature and their potential for use in the clinic, particularly chitosan- and hyaluronic acid-based NPs.

Hyaluronic acid-coated liposomes for targeted delivery of paclitaxel, in-vitro characterization and in-vivo evaluation

Breast cancer is the leading cause of cancer death in women. Chemotherapy is regarded as the most essential strategy in inhibiting the proliferation of tumor cells. Paclitaxel is a widely used taxane; however, the side effects of available Cremophor-based formulations and also the limitations of passive targeting uncovered an essential need to develop tumor-specific targeted nanocarriers. A hyaluronic acid targeted liposomal formulation of paclitaxel was prepared in which, hyaluronic acid was electrostatistically attracted to the surface of liposomes. Liposomes, had a particle size of 106.4±3.2nm, a weakly negative zeta potential of -9.7±0.8mV and an acceptable encapsulation efficiency of 92.1±1.7%. The release profile of liposomes in buffer showed that 95% of PTX was released during 40h. Confocal laser scanning microscopy and flow cytometry analysis showed the greater cellular internalization of coumarin-loaded liposomes compared to free coumarin. MTT assay on 4T1 and T47D cells demonstrated the stronger cytotoxic activity of liposomes in comparison to free paclitaxel. Cell cycle analysis showed that cells were mainly blocked at G2/M phases after 48h treatment with liposomes. In vivo real time imaging on 4T1 tumor-bearing mice revealed that the liposomal formulation mainly accumulated in the tumor area. Liposomes also had better antitumor efficacy against Cremophor-based formulation. In conclusion, hyaluronic acid targeted paclitaxel liposome can serve as a promising targeted formulation of paclitaxel for future cancer chemotherapy.

Sirolimus-loaded polymeric micelles with honokiol for oral delivery

Objectives

The aims of the present study were to design polymeric micelles loading sirolimus with honokiol to increase drug solubility and to gain an insight into the effect of honokiol on oral transport of P-glycoprotein substrate (P-gp).

Methods

Particle size distribution, encapsulation efficiency, drug-loading content and in-vitro release of sirolimus-loaded micelles with honokiol were determined. Transport of sirolimus-loaded micelles across Caco-2 cell monolayers and jejunum segment of rats were investigated. In-vitro cytotoxicity experiments and the cellular uptake study were carried out via sulforhodamine B assay and flow cytometry, respectively.

Key findings

A coadministration of honokiol with sirolimus in micelles did not significantly modify the particle size, polydispersity index and release of drugs demonstrating successful loading within the micelles. The apparent transport coefficients (Papp) and effective permeability (Peff) of sirolimus were increased with more amount of honokiol loaded in micelles. Cellular uptake study demonstrated that rhodamine123 uptake rate was enhanced by honokiol-loaded micelles, indicating substantial P-gp inhibition action by honokiol and mPEG-PLA-based micelles.

Conclusion

Oral transport of sirolimus was significantly improved by coadministration with honokiol, an inhibitor of the P-gp, in polymeric micelles formulation.

A comparison of covalent and noncovalent strategies for paclitaxel release using poly(ester amide) graft copolymer micelles

Micelles formed from amphiphilic copolymers are promising for the delivery of drug molecules, potentially leading to enhanced properties and efficacies. Critical aspects of these systems include the use of biocompatible, biodegradable polymer backbones as well as the ability to control the incorporation of drugs and their release rates. In this work, a poly(ester amide)–poly(ethylene oxide) graft copolymer with paclitaxel conjugated via ester linkages was prepared and assembled into micelles. For comparison, micelles with physically encapsulated paclitaxel were also prepared. The release rates of these two systems were studied, and the micelles with covalently conjugated paclitaxel exhibited a prolonged release of the drug in comparison to the noncovalent system, which rapidly released the payload. In vitro studies suggested that the poly(ester amide)–poly(ethylene oxide) copolymers were nontoxic, whereas the toxicities of the drug-loaded micelles were dependent on their release rates. Overall, these systems are promising for further development as anticancer drug carriers.

Release kinetics study of poorly water-soluble drugs from nanoparticles: are we doing it right?

In vitro drug release kinetics studies are routinely performed to examine the ability of new drug formulations to modulate drug release. The underlying assumption is that the studies are performed in a sufficiently dilute solution, where the drug release is not limited by the solubility and the difference in release kinetics profile reflects the performance of a drug carrier in vivo. This condition is, however, difficult to meet with poorly water-soluble drug formulations, as it requires a very large volume of release medium relative to the formulation mass, which makes it challenging to measure the drug concentration accurately. These difficulties are aggravated with nanoparticle (NP) formulations, which are hard to separate from the release medium and thus require a dialysis bag or repeated high-speed centrifugation for sampling. Perhaps for these reasons, drug release kinetics studies of NPs of poorly water-soluble drugs are often performed in suboptimal conditions in which the NPs are not sufficiently diluted. However, such a practice can potentially underestimate drug release from NPs, leading to an inaccurate prediction that the NPs will attenuate the drug activity in vivo. Here we perform release kinetics studies of two different NP formulations of paclitaxel, a representative poorly water-soluble drug, according to common practices in the literature. We find that the drug release from NPs can be substantially underestimated depending on the choice of the release medium, NP/medium ratio, and handling of release samples. We discuss potential consequences of underestimating drug release, ending with suggestions for future studies with NP formulations of poorly water-soluble drugs.

Glycol chitosan-based fluorescent theranostic nanoagents for cancer therapy

Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging agents and also monitor the response to therapy. Polymeric nanosystems have been intensively explored for biomedical applications to diagnose and treat various cancers. In recent years, glycol chitosan-based nanoagents have been developed as dual-purpose materials for simultaneous diagnosis and therapy. They have shown great potential in cancer therapies, such as chemotherapeutics and nucleic acid and photodynamic therapies. In this review, we summarize the recent progress and potential applications of glycol chitosan-based fluorescent theranostic nanoagents for cancer treatments and discuss their possible underlying mechanisms.

Preparation and characterization of self-assembled nanoparticles based on low-molecular-weight heparin and stearylamine conjugates for controlled delivery of docetaxel

Low-molecular-weight heparin (LMWH)–stearylamine (SA) conjugates (LHSA)-based self-assembled nanoparticles were prepared for intravenous delivery of docetaxel (DCT). 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide were used as coupling agents for synthesis of LHSA conjugates. The physicochemical properties, in vitro antitumor efficacy, in vitro cellular uptake efficiency, in vivo antitumor efficacy, and in vivo pharmacokinetics of LHSA nanoparticles were investigated. The LHSA nanoparticles exhibited a spherical shape with a mean diameter of 140–180 nm and a negative surface charge. According to in vitro release and in vivo pharmacokinetic test results, the docetaxel-loaded LHSA5 (LMWH:SA =1:5) nanoparticles exhibited sustained drug release profiles. The blank LHSA nanoparticles demonstrated only an insignificant cytotoxicity in MCF-7 and MDAMB 231 human breast cancer cells; additionally, higher cellular uptake of coumarin 6 (C6) in MCF-7 and MDAMB 231 cells was observed in the LHSA5 nanoparticles group than that in the C6 solution group. The in vivo tumor growth inhibition efficacy of docetaxel-loaded LHSA5 nanoparticles was also significantly higher than the Taxotere^®-treated group in the MDAMB 231 tumor-xenografted mouse model. These results indicated that the LHSA5-based nanoparticles could be a promising anticancer drug delivery system.

Targeted delivery of anticancer agents via a dual function nanocarrier with an interfacial drug-interactive motif

We have developed a dual-function drug carrier, polyethylene glycol (PEG)-derivatized farnesylthiosalicylate (FTS). Here we report that incorporation of a drug-interactive motif (Fmoc) into PEG_5k–FTS₂ led to further improvement in both drug loading capacity and formulation stability. Doxorubicin (DOX) formulated in PEG_5k–Fmoc–FTS₂ showed sustained release kinetics slower than those of DOX loaded in PEG_5k–FTS₂. The maximum tolerated dose of DOX- or paclitaxel (PTX)-loaded PEG_5k–Fmoc–FTS₂ was significantly higher than that of the free drug. Pharmacokinetics and biodistribution studies showed that DOX/PEG_5k–Fmoc–FTS₂ mixed micelles were able to retain DOX in the bloodstream for a significant amount of time and efficiently deliver the drug to tumor sites. More importantly, drug (DOX or PTX)-loaded PEG_5k–Fmoc–FTS₂ led to superior antitumor activity over other treatments including drugs formulated in PEG_5k–FTS₂ in breast cancer and prostate cancer models. Our improved dual function carrier with a built-in drug-interactive motif represents a simple and effective system for targeted delivery of anticancer agents.

Advances in imaging probes and optical microendoscopic imaging techniques for early in vivo cancer assessment

A new chapter in the history of medical diagnosis happened when the first X-ray technology was invented in the late 1800s. Since then, many non-invasive and minimally invasive imaging techniques have been invented for clinical diagnosis to research in cellular biology, drug discovery, and disease monitoring. These imaging modalities have leveraged the benefits of significant advances in computer, electronics, and information technology and, more recently, targeted molecular imaging. The development of targeted contrast agents such as fluorescent and nanoparticle probes coupled with optical imaging techniques has made it possible to selectively view specific biological events and processes in both in vivo and ex vivo systems with great sensitivity and selectivity. Thus, the combination of targeted molecular imaging probes and optical imaging techniques have become a mainstay in modern medicinal and biological research. Many promising results have demonstrated great potentials to translate to clinical applications. In this review, we describe a discussion of employing imaging probes and optical microendoscopic imaging techniques for cancer diagnosis.

Self-assembled glycol chitosan nanoparticles for disease-specific theranostics

Hydrophobically modified glycol chitosan (hGC) conjugates spontaneously form self-assembled nanoparticles (NPs) in aqueous conditions, and glycol chitosan NPs (CNPs) have been extensively studied for the past few decades. For disease-specific theranostics, CNPs could be simply modified with imaging agents, and the hydrophobic domains of hGC are available for encapsulation of various drugs. Based on the excellent physiochemical and biological properties, CNPs have been investigated for multimodal imaging and target specific drug delivery. In particular, a recent application of CNPs has shown great potential as an efficient theranostic system because the CNPs could be utilized for a disease-specific theranostic delivery system of different imaging agents and therapeutics, simultaneously. Furthermore, various therapeutic agents including chemo-drugs, nucleotides, peptides, and photodynamic chemicals could be simply encapsulated into the CNPs through hydrophobic or charge-charge interactions. Under in vivo conditions, the encapsulated imaging agents and therapeutic drugs have been successfully delivered to targeted diseases. In this article, the overall research progress on CNPs is reviewed from early works. The current challenges of CNPs to overcome in theranostics are also discussed, and continuous studies would provide more opportunities for early diagnosis of diseases and personalized medicine.

Nanomicellar carriers for targeted delivery of anticancer agents

Clinical application of anticancer drugs is limited by problems such as low water solubility, lack of tissue-specificity and toxicity. Formulation development represents an important approach to these problems. Among the many delivery systems studied, polymeric micelles have gained considerable attention owing to ease in preparation, small sizes (10-100 nm), and ability to solubilize water-insoluble anticancer drugs and accumulate specifically at the tumors. This article provides a brief review of several promising micellar systems and their applications in tumor therapy. The emphasis is placed on the discussion of the authors' recent work on several nanomicellar systems that have both a delivery function and antitumor activity, named dual-function drug carriers.

Chitosan coating of copper nanoparticles reduces in vitro toxicity and increases inflammation in the lung

Despite their potential for a variety of applications, copper nanoparticles induce very strong inflammatory responses and cellular toxicity following aerosolized delivery. Coating metallic nanoparticles with polysaccharides, such as biocompatible and antimicrobial chitosan, has the potential to reduce this toxicity. In this study, copper nanoparticles were coated with chitosan using a newly developed and facile method. The presence of coating was confirmed using x-ray photoelectron spectroscopy, rhodamine tagging of chitosan followed by confocal fluorescence imaging of coated particles and observed increases in particle size and zeta potential. Further physical and chemical characteristics were evaluated using dissolution and x-ray diffraction studies. The chitosan coating was shown to significantly reduce the toxicity of copper nanoparticles after 24 and 52 h and the generation of reactive oxygen species as assayed by DHE oxidation after 24 h in vitro. Conversely, inflammatory response, measured using the number of white blood cells, total protein, and cytokines/chemokines in the bronchoalveolar fluid of mice exposed to chitosan coated versus uncoated copper nanoparticles, was shown to increase, as was the concentration of copper ions. These results suggest that coating metal nanoparticles with mucoadhesive polysaccharides (e.g. chitosan) could increase their potential for use in controlled release of copper ions to cells, but will result in a higher inflammatory response if administered via the lung.

Paclitaxel Nano-Delivery Systems: A Comprehensive Review

Paclitaxel is one of the most effective chemotherapeutic drugs ever developed and is active against a broad range of cancers, such as lung, ovarian, and breast cancers. Due to its low water solubility, paclitaxel is formulated in a mixture of Cremophor EL and dehydrated ethanol (50:50, v/v) a combination known as Taxol. However, Taxol has some severe side effects related to Cremophor EL and ethanol. Therefore, there is an urgent need for the development of alternative Taxol formulations. The encapsulation of paclitaxel in biodegradable and non-toxic nano-delivery systems can protect the drug from degradation during circulation and in-turn protect the body from toxic side effects of the drug thereby lowering its toxicity, increasing its circulation half-life, exhibiting improved pharmacokinetic profiles, and demonstrating better patient compliance. Also, nanoparticle-based delivery systems can take advantage of the enhanced permeability and retention (EPR) effect for passive tumor targeting, therefore, they are promising carriers to improve the therapeutic index and decrease the side effects of paclitaxel. To date, paclitaxel albumin-bound nanoparticles (Abraxane®) have been approved by the FDA for the treatment of metastatic breast cancer and non-small cell lung cancer (NSCLC). In addition, there are a number of novel paclitaxel nanoparticle formulations in clinical trials. In this comprehensive review, several types of developed paclitaxel nano-delivery systems will be covered and discussed, such as polymeric nanoparticles, lipid-based formulations, polymer conjugates, inorganic nanoparticles, carbon nanotubes, nanocrystals, and cyclodextrin nanoparticles.

Polymer nanoassemblies for cancer treatment and imaging

Amphiphilic polymers represented by block copolymers self-assemble into well-defined nanostructures capable of incorporating therapeutics. Polymer nanoassemblies currently developed for cancer treatment and imaging are reviewed in this article. Particular attention is paid to three representative polymer nanoassemblies: polymer micelles, polymer micellar aggregates and polymer vesicles. Rationales, design and performance of these polymer nanoassemblies are addressed, focusing on increasing the solubility and chemical stability of drugs. Also discussed are polymer nanoassembly formation, the distribution of polymer materials in the human body and applications of polymer nanoassemblies for combined therapy and imaging of cancer. Updates on tumor-targeting approaches, based on preclinical and clinical results are provided, as well as solutions for current issues that drug-delivery systems have, such as in vivo stability, tissue penetration and therapeutic efficacy. These are discussed to provide insights on the future development of more effective polymer nanoassemblies for the delivery of therapeutics in the body.

Effect of cell-penetrating peptide-coated nanostructured lipid carriers on the oral absorption of tripterine

PURPOSE

To develop nanostructured-lipid carriers (NLCs) coated with cell-penetrating peptides (CPP) for improving the oral bioavailability of tripterine.

METHODS

We prepared CPP-coated tripterine-loaded NLCs (CT-NLCs) by using a solvent evaporation method, and determined their physical properties. In vitro drug release was determined by using a dialysis bag diffusion technique, and intestinal toxicity was evaluated by performing MTT assay using Caco-2 cells. In vivo absorption was studied in an in situ rat intestinal perfusion model, and oral bioavailability was examined in beagles.

RESULTS

The average particle size, zeta potential, and encapsulation efficiency of the optimized CT-NLCs were 126.7 ± 9.2 nm, 28.7 ± 3.4 mV, and 72.64% ± 1.37%, respectively. The CT-NLCs showed a controlled release profile in vitro and had significantly lower intestinal cytotoxicity than the tripterine solution (P < 0.05). The absorption levels of tripterine from the CT-NLCs in the rat duodenum and jejunum were markedly higher than with tripterine-loaded NLCs without the CPP coating (T-NLCs), and with tripterine solution. Pharmacokinetic study showed that the maximum concentration of the CT-NLCs was greater than that of the T-NLCs and tripterine suspension, and that the time to maximum concentration of the CT-NLCs as well as the T-NLCs, was longer than that of the tripterine suspension. The relative oral bioavailability of the CT-NLCs compared to that of tripterine suspension and T-NLCs were 484.75% and 149.91% respectively.

CONCLUSION

The oral bioavailability of tripterine is dramatically increased by CT-NLCs. Therefore, CT-NLCs seem to be a promising carrier for oral delivery of tripterine.

Enhanced oral bioavailability of paclitaxel in pluronic/LHR mixed polymeric micelles: preparation, in vitro and in vivo evaluation

In order to enhance paclitaxel oral bioavailability, mixed polymeric micelles that comprised of pluronic copolymers and low molecular weight heparin-all-trans-retinoid acid (LHR) conjugate were developed. PTX-loaded mixed polymeric micelles (MPMs) were prepared by dialysis method with high drug loading 26.92 ± 2.08% and 25.82 ± 1.9% for F127/LHR and P188/LHR MPMs respectively, and were found to be spherical in shape with an average size of around 140 nm and a narrow size distribution. In vitro release study showed that pluronic/LHR MPMs exhibited delayed release characteristics compared to Taxol and faster drug release profile compared to LHR plain polymeric micelles (PPMs). The cytotoxic activity of PTX-loaded pluronic/LHR MPMs was slightly higher than LHR PPMs in MCF-7 cells (p<0.01). In situ effective permeability of PTX through rat small intestine was 5- to 6-fold higher with mixed micelles than that of Taxol. Moreover, pluronic/LHR MPMs achieved significantly higher AUC and C(max) level than both of LHR PPMs and Taxol. This enhancement might be due to the inhibition of both P-glycoprotein efflux system and cytochrome P450 metabolism by pluronic copolymers. The current results encourage further development of paclitaxel mixed polymeric micelles as an oral drug delivery system.