Oral Delivery of Doxorubicin Using Novel Polyelectrolyte-Stabilized Liposomes (Layersomes)

Layer-by-Layer polyelectrolyte assemblies for encapsulation and release of active compounds

Soft assemblies obtained following the Layer-by-Layer (LbL) approach are accounted among the most interesting systems for designing biomaterials and drug delivery platforms. This is due to the extraordinary versatility and flexibility offered by the LbL method, allowing for the fabrication of supramolecular multifunctional materials using a wide range of building blocks through different types of interactions (electrostatic, hydrogen bonds, acid-base or coordination interactions, or even covalent bonds). This provides the bases for the building of materials with different sizes, shapes, compositions and morphologies, gathering important possibilities for tuning and controlling the physico-chemical properties of the assembled materials with precision in the nanometer scale, and consequently creating important perspective for the application of these multifunctional materials as cargo systems in many areas of technological interest. This review studies different physico - chemical aspects associated with the assembly of supramolecular materials by the LbL method, paying special attention to the description of these aspects playing a central role in the application of these materials as cargo platforms for encapsulation and release of active compounds.

Fabrication of Calcium Phosphate-Based Nanocomposites Incorporating DNA Origami, Gold Nanorods, and Anticancer Drugs for Biomedical Applications

DNA origami is designed by folding DNA strands at the nanoscale with arbitrary control. Due to its inherent biological nature, DNA origami is used in drug delivery for enhancement of synergism and multidrug resistance inhibition, cancer diagnosis, and many other biomedical applications, where it shows great potential. However, the inherent instability and low payload capacity of DNA origami restrict its biomedical applications. Here, this paper reports the fabrication of an advanced biocompatible nano-in-nanocomposite, which protects DNA origami from degradation and facilities drug loading. The DNA origami, gold nanorods, and molecular targeted drugs are co-incorporated into pH responsive calcium phosphate [Ca₃ (PO₄ )₂ ] nanoparticles. Subsequently, a thin layer of phospholipid is coated onto the Ca₃ (PO₄ )₂ nanoparticle to offer better biocompatibility. The fabricated nanocomposite shows high drug loading capacity, good biocompatibility, and a photothermal and pH-responsive payload release profile and it fully protects DNA origami from degradation. The codelivery of DNA origami with cancer drugs synergistically induces cancer cell apoptosis, reduces the multidrug resistance, and enhances the targeted killing efficiency toward human epidermal growth factor receptor 2 positive cells. This nanocomposite is foreseen to open new horizons for a variety of clinical and biomedical applications.

Preparation and characterization of surface-modified PLGA-polymeric nanoparticles used to target treatment of intestinal cancer

Docetaxel (DTX), a cytotoxic taxane, is a poor water-soluble drug and exhibits less oral bioavailability. Current research investigates the effective transport, for DTX-loaded chitosan (CS)-coated-poly-lactide-co-glycolide (PLGA)-nanoparticles (NPs) (DTX-CS-PLGA-NPs) and DTX-PLGA-NPs as well as a novel third-generation P-gp inhibitor i.e. GF120918 (Elacridar), across intestinal epithelium with its successive uptake by the tumour cells in an in vitro model. The prepared NPs showed a spherical shape particle size i.e. <123.96 nm with polydispersity index (PDI) of <0.290 whereas for CS-coated NPs, the zeta potential was converted from negative to positive value along with a small modification in particle size distribution. The entrapment efficiency observed for DTX-CS-PLGA-NPs was 74.77%, whereas the in vitro release profile revealed an initial rapid DTX release followed by a sustained release pattern. For apparent permeability, DTX-CS-PLGA-NPs and DTX-PLGA-NPs along with GF120918 showed a five-fold (p < .01) and 2.2-fold enhancement, respectively, as observed in rat ileum permeation study. Similarly, for pharmacokinetic (PK) studies, higher oral bioavailability was observed from DTX-CS-PLGA-NPs (5.11-folds) and DTX-PLGA-NPs (3.29-folds) as compared with DTX-suspension (DTX-S). Cell uptake studies on A549 cells as performed for DTX-CS-PLGA-NPs and DTX-PLGA-NPs loaded with rhodamine 123 dye, exhibited enhanced uptake as compared with plain dye solution. The enhanced uptake for DTX-CS-PLGA-NPs and DTX-PLGA-NPs formulations in the presence of GF120918 was confirmed further with the help of confocal laser scanning microscopic images (CLSM). The potential of the third-generation novel P-gp inhibitor (GF120918) investigated for the effective delivery of DTX as well as investigation of permeability and uptake studies whereby a strong potential of GF120918 for effective oral delivery was established.

Doxorubicin-loaded liposomes: enhancing the oral bioavailability by modulation of physicochemical characteristics

Aim: In this study, the effects of liposome characteristics on oral absorption of doxorubicin, as a hydrophilic low-permeability drug, were investigated. Materials & methods: Different doxorubicin-loaded liposomes were prepared, characterized and orally administered to 18 groups of rats. Plasma concentrations of doxorubicin and its aglycone metabolite were measured, and Caco-2 uptake and transport of optimum liposomes were investigated. Results: After studying different factors, a fourfold increase in oral bioavailability was achieved with the non-PEGylated, 120-nm-sized positively charged rigid liposomes (lipid to drug ratio = 10). The extent of drug’s first-pass metabolism as well as endocytosis of nanoparticles were markedly affected by liposomal formulation. Conclusion: Oral absorption is highly dependent on liposomal properties, and optimum formulations are effective for low-permeability drugs.

Self-assembled hemoglobin nanoparticles for improved oral photosensitizer delivery and oral photothermal therapy in vivo

AIM

The aim of the present study was to use hemoglobin (Hb) nanoparticles (NPs) to improve oral bioavailability of a near-infrared dye IR780 for in vivo antitumor application in photothermal therapy.

METHODS

One-step acid-denaturing method was used to encapsulate IR780 into self-assembled Hb NPs (IR780@Hb NPs). Pharmacokinetics, biodistribution and antitumor effect were studied in vivo.

RESULTS

The Hb NPs showed high stability in enzymatic and acidic conditions similar to the gastric environment, and enhanced absorption of IR780 into the blood. In vivo imaging revealed that IR780 could accumulate at the tumor sites and effectively caused photothermal effect, which resulted in tumor ablation after oral administration in tumor-bearing mice.

CONCLUSION

Hb NPs represent a promising delivery system for improving oral absorption of photosensitizer dyes, which could open new treatment modalities in cancer.

α-Tocopherol as functional excipient for resveratrol and coenzyme Q10-loaded SNEDDS for improved bioavailability and prophylaxis of breast cancer

The present study evaluates the prophylactic efficacy of α-tocopherol (α-TOH), resveratrol (RES), and coenzyme Q10 (CoQ10) co-loaded self-nanoemulsifying drug delivery system (α-TOH-RES-CoQ10 SNEDDS) in 7,12-Dimethylbenz[a]anthracene (DMBA) induced breast cancer model. SNEDDS formulation components were rationally selected and optimized for maximum drug loading by applying the design of experiments and further evaluated for stability in simulated gastrointestinal fluids, functional stability of antioxidants, in vitro release, Caco-2 cell uptake, oral bioavailability and prophylactic anticancer activity. The SNEDDS demonstrated excellent stability in stimulated gastrointestinal fluids. The functional activity of antioxidants was confirmed by 2,2-diphenylpicrylhydrazyl (DPPH) scavenging assay wherein significantly (p > .05) higher antioxidant activity was observed in case of SNEDDS as compared with free antioxidants. Coumarin 6 (C-6)-loaded SNEDDS formulation demonstrated remarkably higher Caco-2 cell uptake in comparison with free C-6, indicative of efficient internalization of sub-micron SNEDDS droplets by Caco-2 cells. In line with Caco-2 cell uptake observations, α-TOH-RES-CoQ10-SNEDDS showed ∼2.30- and ∼3.64-fold increase in the AUC_0-∞ values of RES and CoQ10 in comparison with free antioxidants. Significantly lower (p < .001) tumor volume (∼327 mm³) was found in case of animals treated with α-TOH-RES-CoQ10-SNEDDS in comparison with free antioxidant combination (∼1070 mm³) and DMBA control (∼1540 mm³) groups. Conclusively, the proposed strategy posed great potential in improving the prophylactic activity of antioxidants and hold promise for further exploration.

Poly-ion Complex of Chondroitin Sulfate and Spermine and Its Effect on Oral Chondroitin Sulfate Bioavailability

Chondroitin sulfate (CS) has been accepted as an ingredient in health foods for the treatment of symptoms related to arthritis and cartilage repair. However, CS is poorly absorbed through the gastrointestinal tract because of its high negative electric charges and molecular weight (MW). In this study, poly-ion complex (PIC) formation was found in aqueous solutions through electrostatic interaction between CS and polyamines-organic molecules having two or more primary amino groups ubiquitously distributed in natural products at high concentrations. Characteristic properties of various PICs generated by mixing CS and natural polyamines, including unusual polyamines, were studied based on the turbidity for PIC formation, the dynamic light scattering for the size of PIC particles, and ζ-potential measurements for the surface charges of PIC particles. The efficiency of PIC formation between CS and spermine increased in a CS MW-dependent manner, with 15 kDa CS being critical for the formation of PIC (particle size: 3.41 µm) having nearly neutral surface charge (ζ-potential: -0.80 mV). Comparatively, mixing tetrakis(3-aminopropyl)ammonium and 15 kDa of CS afforded significant levels of PIC (particle size: 0.42±0.16 µm) despite a strongly negative surface charge (-34.67±1.15 mV). Interestingly, the oral absorption efficiency of CS was greatly improved only when PIC possessing neutral surface charges was administered to mice. High formation efficiency and electrically neutral surface charge of PIC particles are important factors for oral CS bioavailability.

Mucoadhesive nanostructured lipid carriers (NLCs) as potential carriers for improving oral delivery of curcumin

PURPOSE

To examine effects of polymer types on the mucoadhesive properties of polymer-coated nanostructured lipid carriers (NLCs). Experiment: Curcumin-loaded NLCs were prepared using a warm microemulsion technique followed by coating particle surface with mucoadhesive polymers: polyethylene glycol400 (PEG400), polyvinyl alcohol (PVA), and chitosan (CS). The physicochemical properties and entrapment efficacy were examined. In vitro mucoadhesive studies were assessed by wash-off test. In addition, the stability of mucoadhesive NLCs in gastrointestinal fluids and the pattern of drug release were also investigated.

FINDINGS

The obtained nanoparticles showed spherical shape with size ranging between 200 nm and 500 nm and zeta potential between -37 and -9 mV depending on the type of polymer coating. Up to 80% drug entrapment efficacy was observed. In vitro mucoadhesive studies revealed that PEG-NLCs and PVA-NLCs were adhered strongly to freshly porcine intestinal mucosa, more than 2-fold mucoadhesive compared to CS-NLCs and uncoated-NLCs. The particle size of all polymer-coated NLCs could be maintained in both simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) suggesting good physical stability in physiological fluid. In contrast, uncoated-NLCs showed particle aggregation in SGF. In vitro dissolution studies revealed a fast release characteristic.

IN VITRO RELEASE KINETICS MODEL FITTING OF LIPOSOMES: AN INSIGHT

Liposomes are emerging cargoes for bioactive delivery owing to their widely accepted biocompatible and biodegradable nature. It is always a challenge to control the release of payload for effective delivery to the site of interest. Over the couple of decennia, mathematical modeling of release process is a need of time whether the drug remains in the circulation or reaches at the target site. For establishing a better in vitro - in vivo correlation, release kinetics models viz. Peppas, Higuchi, Weibull, Zero Order and First order including mechanistic models like All-or-None, Toroidal, and Biomembrane models etc. are continuously exploited to predict drug release profile. Most of these models rely on the diffusion equations based on the composition of liposomes and conditions of release. Here, we summarized the crucial reports exploring these models and associated interventions to know the underlying physicochemical release phenomenon. Such mathematical model fitting can be a promising approach to deduce release/delivery process to help in designing the safe and efficacious ("Smart") liposomes.

Role of nanoparticle size, shape and surface chemistry in oral drug delivery

Nanoparticles find intriguing applications in oral drug delivery since they present a large surface area for interactions with the gastrointestinal tract and can be modified in various ways to address the barriers associated with oral delivery. The size, shape and surface chemistry of nanoparticles can greatly impact cellular uptake and efficacy of the treatment. However, the interplay between particle size, shape and surface chemistry has not been well investigated especially for oral drug delivery. To this end, we prepared sphere-, rod- and disc-shaped nanoparticles and conjugated them with targeting ligands to study the influence of size, shape and surface chemistry on their uptake and transport across intestinal cells. A triple co-culture model of intestinal cells was utilized to more closely mimic the intestinal epithelium. Results demonstrated higher cellular uptake of rod-shaped nanoparticles in the co-culture compared to spheres regardless of the presence of active targeting moieties. Transport of nanorods across the intestinal co-culture was also significantly higher than spheres. The findings indicate that nanoparticle-mediated oral drug delivery can be potentially improved with departure from spherical shape which has been traditionally utilized for the design of nanoparticles. We believe that understanding the role of nanoparticle geometry in intestinal uptake and transport will bring forth a paradigm shift in nanoparticle engineering for oral delivery and non-spherical nanoparticles should be further investigated and considered for oral delivery of therapeutic drugs and diagnostic materials.

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

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

Advances in oral delivery of anti-cancer prodrugs

INTRODUCTION

Most anticancer drugs have poor aqueous solubility and low permeability across the gastrointestinal tract. Furthermore, extensive efflux by P-glycoproteins (P-gp) in the small intestine also limits the efficient delivery of anticancer drugs via oral route. Area covered: This review explores the prodrug strategy for oral delivery of anticancer drugs. Different categories of oral anticancer prodrugs along with recent clinical studies have been comprehensively reviewed here. Furthermore, novel anticancer prodrugs such as polymer-prodrugs and lipid-prodrugs have been discussed in detail. Finally, various nanocarrier-based approaches employed for oral delivery of anticancer prodrugs have also been discussed. Expert opinion: Premature degradation of anticancer prodrugs in the gastrointestinal tract could lead to variable pharmacokinetics and undesired toxicity. Despite their increased aqueous solubility, the oral bioavailability of several anticancer prodrugs are limited by their poor permeability across the gastrointestinal tract. These limitations can be overcome by the use of functional excipients (polymers, lipids, amino acids/dipeptides), which are specifically absorbed via transporters and receptor-mediated endocytosis. Oral delivery of anticancer prodrugs using nanocarrier-based drug delivery system is a recent development; however it should be justified based on the comparative advantages of encapsulating prodrug in a nanocarrier versus the use of anticancer prodrug molecule itself.

In Vitro and Ex Vivo Evaluations of Lipid Anti-Cancer Nanoformulations: Insights and Assessment of Bioavailability Enhancement

Lipid-based nanoformulations have been extensively investigated for improving oral efficacy of plethora of drugs. Chemotherapeutic agents remain a preferred option for effective management of cancer; however, most chemotherapeutic agents suffer from limitation of poor oral bioavailability that is associated with their physicochemical properties. Drug delivery via lipid-based nanosystems possesses strong rational and potential for improving oral bioavailability of such anti-cancer molecules through various mechanisms, viz. improving their gut solubilisation owing to micellization, improving mucosal permeation, improving lymphatic uptake, inhibiting intestinal metabolism and/or inhibiting P-glycoprotein efflux of molecules in the gastrointestinal tract. Various in vitro characterization techniques have been reported in literature that aid in getting insights into mechanisms of lipid-based nanodevices in improving oral efficacy of anti-cancer drugs. The review focuses on different characterization techniques that can be employed for evaluation of lipid-based nanosystems and their role in effective anti-cancer drug delivery.

Recent advances in liposome surface modification for oral drug delivery

Oral delivery via the gastrointestinal (GI) tract is the dominant route for drug administration. Orally delivered liposomal carriers can enhance drug solubility and protect the encapsulated theraputic agents from the extreme conditions found in the GI tract. Liposomes, with their fluid lipid bilayer membrane and their nanoscale size, can significantly improve oral absorption. Unfortunately, the clinical applications of conventional liposomes have been hindered due to their poor stability and availability under the harsh conditions typically presented in the GI tract. To overcome this problem, the surface modification of liposomes has been investigated. Although liposome surface modification has been extensively studied for oral drug delivery, no review exists so far that adequately covers this topic. The purpose of this paper is to summarize and critically analyze emerging trends in liposome surface modification for oral drug delivery.

Multilayer engineered nanoliposomes as a novel tool for oral delivery of lipopeptide-based vaccines against group A Streptococcus

Aim: To develop an oral nanovaccine delivery system for lipopeptide-based vaccine candidate against group A Streptococcus. Materials & methods: Lipid-core peptide-1-loaded nanoliposomes were prepared as a template and coated with opposite-charged polyelectrolytes to produce particles with size <200 nm. Efficacy of this oral nanovaccine delivery system was evaluated in mice model. Results: Polymer-coated liposomes produced significantly higher antigen-specific mucosal IgA and systemic IgG titers in comparison to vaccine formulated with a strong mucosal adjuvant upon oral immunization in mice. Moreover, high levels of systemic antibody titers were retained even at day 185 postprimary immunization. Conclusion: Efficient oral delivery platform for lipopeptide-based vaccines has been developed.

Effect of different types of surfactants on the physical properties and stability of carvedilol nano-niosomes

BACKGROUND

Niosomes are non-ionic surfactant vesicles used as drug carriers for encapsulating both hydrophobic and hydrophilic drugs. The aim of this study is to evaluate the effect of different surfactants on the physical properties and stability of carvedilol niosomes designed to improve oral bioavailability.

MATERIALS AND METHODS

Different niosomal formulations were prepared using a film hydration method, with various mixtures of different non-ionic surfactants including Span 20, 40, and 60, and also Tween 20, 40, and 60, along with cholesterol. The physicochemical characteristics of the formulations were evaluated in vitro.

RESULTS

The drug encapsulation efficiency was reduced by using lauryl (C12) chain containing surfactants, that is, Span/Tween. Cholesterol content and drug entrapment were the main factors affecting the mean particle size of the niosomes. The drug release profiles from most of the formulations were fitted well with the Baker-Lonsdale model, indicating a diffusion-based drug release mechanism. Niosomes prepared from 50 and 40% of the cholesterol with 25 or 30% of Span/Tween 60 showed the highest stability due to their high transition temperature and solid state feature of these surfactants.

CONCLUSIONS

From the results obtained, it may be concluded that nanoniosomes are promising stable carriers for the oral delivery of carvedilol.

Polymer-lipid hybrid systems: merging the benefits of polymeric and lipid-based nanocarriers to improve oral drug delivery

INTRODUCTION

A number of biobarriers limit efficient oral drug absorption; both polymer-based and lipid-based nanocarriers have demonstrated properties and delivery mechanisms to overcome these biobarriers in preclinical settings. Moreover, in order to address the multifaceted oral drug delivery challenges, polymer-lipid hybrid systems are now being designed to merge the beneficial features of both polymeric and lipid-based nanocarriers.

AREAS COVERED

Recent advances in the development of polymer-lipid hybrids with a specific focus on their viability in oral delivery are reviewed. Three classes of polymer-lipid hybrids have been identified, i.e. lipid-core polymer-shell systems, polymer-core lipid-shell systems, and matrix-type polymer-lipid hybrids. We focus on their application to overcome the various biological barriers to oral drug absorption, as exemplified by selected preclinical studies.

EXPERT OPINION

Numerous studies have demonstrated the superiority of polymer-lipid hybrid systems to their non-hybrid counterparts in providing improved drug encapsulation, modulated drug release, and improved cellular uptake. These features have encouraged their applications in the delivery of chemotherapeutics, proteins, peptides, and vaccines. With further research expected to optimize the manufacturing and scaling up processes and in-depth pre-clinical pharmacological and toxicological assessments, these multifaceted drug delivery systems will have significant clinical impact on the oral delivery of pharmaceuticals and biopharmaceuticals.

Development of dual toxoid-loaded layersomes for complete immunostimulatory response following peroral administration

AIM

Present study reports the development of divalent vaccine with enhanced protection, permeation and presentation following peroral immunization.

MATERIALS & METHODS

Layersomes were prepared by layer-by-layer tuning of polyelectrolytes on liposomes template. The developed system was evaluated for in vitro stability of antigen and layersomes, cell-based assays and immunization experiments in mice.

RESULTS

Layersomes exhibited enhanced stability in simulated biological fluids, still preserving the integrity, biological activity and conformational stability of toxoids. Layersomes also exhibited complete and protective (>0.1 IU/ml) immunostimulatory response include serum IgG titer, mucosal sIgA titer and cytokines (IL-2 and IFN-γ) levels following peroral administration.

CONCLUSION

The positive findings of proposed strategy are expected to contribute significantly in the field of stable liposomes technology and peroral immunization.

Surface decorated nanoparticles as surrogate carriers for improved transport and absorption of epirubicin across the gastrointestinal tract: Pharmacokinetic and pharmacodynamic investigations

Epirubicin (EPI) is a P-gp substrate antracycline analogue which elicits poor oral bioavailability. In the present work, EPI loaded poly-lactide-co-glycolic acid nanoparticles (PLGA-NPs) were prepared by double emulsion approach and superficially decorated with polyethylene glycol (EPI-PNPs) and mannosamine (EPI-MNPs). Average hydrodynamic particle size of EPI-PNPs and EPI-MNPs was found 248.63 ± 12.36 and 254.23 ± 15.16 nm, respectively. Cytotoxicity studies were performed against human breast adenocarcinoma cell lines (MCF-7) confirmed the superiority of EPI-PNPs and EPI-MNPs over free epirubicin solution (EPI-S). Further, confocal laser scanning microscopy (CLSM) and flow cytometric analysis (FACS) demonstrated enhanced drug uptake through EPI-PNPs and EPI-MNPs and elucidated dominance of caveolae mediated endocytosis for NPs uptake. Cellular transport conducted on human colon adenocarcinoma cell line (Caco-2) showed 2.45 and 3.17 folds higher permeability of EPI through EPI-PNPs and EPI-MNPs when compared with EPI-S (p<0.001) while permeability of EPI was found 5.23 and 5.67 folds higher across rat ileum, respectively. Furthermore, pharmacokinetic studies demonstrated 4.7 and 5.57 folds higher oral bioavailability through EPI-PNPs and EPI-MNPs when compared with EPI-S. In addition, both, EPI-PNPs and EMNPs showed tumor suppression comparable to indicated route (i.v. injection). EPI-MNPs showed 1.18 folds higher bioavailability and better tumor suppression than EPI-PNPs.

Lipid-based nanovesicles for nanomedicine

Multifunctional lipid-based nanovesicles (L-NVs) prepared by molecular self-assembly of membrane components together with (bio)-active molecules, by means of compressed CO₂-media or other non-conventional methods lead to highly homogeneous, tailor-made nanovesicles that are used for advanced nanomedicine. Confocal microscopy image of siRNA transfection using L-NVs, reprinted with permission from de Jonge,et al.,Gene Therapy, 2006,13, 400–411.

Enhanced efficacy of chemotherapy for breast cancer stem cells by simultaneous suppression of multidrug resistance and antiapoptotic cellular defense

While chemotherapy is universally recognized as a frontline treatment strategy for breast cancer, it is not always successful; among the leading causes of treatment failure is existing and/or acquired multidrug resistance. Cancer stem cells (CSCs), which constitute a minority of the cells of a tumor, are acknowledged to be responsible for increased resistance to chemo-drugs through a combination of increased expression of ATP-binding cassette transporters (ABC transporters), an increased anti-apoptotic defense, and/or the ability for extensive DNA repair like normal stem cells. Consequently, more effective therapy, especially targeted to CSCs, is urgently required. We studied the characteristics of 231-CSCs (CD44+/CD24-) sorted from human MDA-MB-231 breast cancer cells and demonstrated that 231-CSCs exhibited enhanced capacities for proliferation, migration, tumorigenesis and chemotherapy resistance. To address these multifunctional facets of CSCs, we devised a non-ionic surfactant-based vesicle (niosome) co-delivery system to simultaneously deliver siRNAs, targeted to both the ABC transporter (ABCG2) and the anti-apoptosis defense gene (BCL2), and doxorubicin (DOX) to CSCs. The rationale is to sensitize CSCs to DOX by down regulating the drug-resistance gene ABCG2 and simultaneously induce apoptosis by lowering BCL2 expression. The co-delivery system (CDS) successfully delivered siRNAs and DOX to the cytoplasm and nuclei, respectively, and resulted in a down-regulation of ABCG2- and BCL2 mRNAs in CSCs by 60% and 65%, respectively, compared to the control. A corresponding decrease in protein expression was observed using Western blotting. The IC50 of DOX in CSCs concurrently decreased significantly. Our result established CDS as a promising multi-drug delivery platform for cancer treatment.

STATEMENT OF SIGNIFICANCE

Cancer stem cells (CSCs) are acknowledged to be responsible for increased resistance to chemo-drugs through a combination of increased expression of ABC transporters, an increased anti-apoptotic defense, and/or the ability for extensive DNA repair like normal stem cells. Consequently, effective therapy, especially to CSCs, is urgently required. In current study, we studied the characteristics of 231-CSCs sorted from human MDA-MB-231 breast cancer cells and found that 231-CSCs possessed enhanced proliferation, migration, tumorigenesis, and DOX resistance. We employed a non-ionic surfactant-based vesicle (niosome) delivery system to simultaneously deliver siRNAs targeted to multi-drug resistance genes, and DOX to kill 231-CSCs. The CDS showed an enhanced therapeutic effect by resensitizing 231-CSCs to DOX and may constitute a promising candidate for cancer chemotherapy.

Oral and IV dosages of doxorubicin-methotrexate loaded- nanoparticles inhibit progression of oral cancer by down- regulation of matrix Methaloproteinase 2 expression in vivo

Oral cancer is one of the most common and lethal cancers in the world. Combination chemotherapy coupled with nanoparticle drug delivery holds substantial promise in cancer therapy. This study aimed to evaluate the efficacy and safety of two dosages of our novel pH and temperature sensitive doxorubicin-methotrexate-loaded nanoparticles (DOX-MTX NPs) with attention to the MMP-2 mRNA profile in a 4-nitroquinoline-1-oxide induced oral squamous cell carcinoma (OSCC) model in the rat. Our results showed that both IV and oral dosages of DOX-MTX NP caused significant decrease in mRNA levels of MMP-2 compared to the untreated group (p<0.003). Surprisingly, MMP-2 mRNA was not affected in DOX treated compared to cancer group (p>0.05). Our results indicated that IV dosage of MTX-DOX is more effective than free DOX (12 fold) in inhibiting the activity of MMP-2 in OSCCs (P<0.001). Furthermore, MMP-2 mRNA expression in the DOX-MTX treated group showed a significant relation with histopathological changes (P=0.011). Compared to the untreated cancer group, we observed no pathological changes and neither a significant alteration in MMP-2 amount in either of healthy controls that were treated with oral and IV dosages of DOX-MTX NPs whilst cancer group showed a high level of MMP-2 expression compared to healthy controls (p<0.001).Taking together our results indicate that DOX- MTX NPs is a safe chemotherapeutic nanodrug that its oral and IV forms possess potent anti-cancer properties on aggressive tumors like OSCC, possibly by affecting the expression of genes that drive tumor invasion and metastasis.

Pirfenidone-loaded liposomes for lung targeting: preparation and in vitro/in vivo evaluation

BACKGROUND

The purpose of this study was to develop novel pirfenidone (PFD)-loaded liposomes for targeting to the lung.

METHODS

The liposomes were prepared by the film hydration method, and their in vitro/vivo characteristics were evaluated.

RESULTS

The PFD liposomes appeared visually as green to yellowish suspensions and were spherical in shape. The particle size was 582.3±21.6 nm and the entrapment efficiency was relatively high (87.2%±5.7%). The liposomes showed typical sustained and prolonged drug-release behavior in vitro and fitted well with the Weibull distribution equation. The relatively slower time taken to reach a minimal plasma PFD concentration in vivo suggests that PFD liposomes have a sustained-release profile, which is consistent with the results of the in vitro release study. The PFD liposomes showed the largest area under the curve for the lung. The high distribution of PFD achieved in the lungs using this liposomal formulation may be explained by physical entrapment of the liposomes in the vascular network of the lung. Histopathological results indicated that liposomal PFD could alleviate pathological injury in lung tissue.

CONCLUSION

This liposomal formulation can enable sustained release of PFD and increase targeting to the lung.

DOX-MTX-NPs augment p53 mRNA expression in OSCC model in rat: effects of IV and oral routes

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the sixth most common malignancy worldwide. Cancer development and progression require inactivation of tumor suppressor genes and activation of proto-oncogenes. The well recognized mechanism of action demonstrated for chemotherapeutic agents is induction of apoptosis via reactivation of p53. In this context, we evaluate the efficacy of IV and oral routes of our novel PH and temperature sensitive doxorubicin-methotrexate-loaded nanoparticles (DOX-MTX NP) in affecting p53 profile in an OSCC rat model.

METHODS

In this study, 120 male rats were divided into 8 groups of 15 animals each. The new formulated DOX-MTX NP and free doxorubicin were IV and orally given to rats with 4-nitroquinoline-1- oxide induced OSCC.

RESULTS

RESULTS showed that both DOX and DOX-MTX-NP caused significant increase in mRNA levels of P53 compared to the untreated group (p<0.000). With both DOX and DOX-MTX NP, the IV mode was more effective than the oral (gavage) route (p<0.000). Surprisingly, in oral mode, p53 mRNA was not affected in DOX treated groups (p>0.05), Nonetheless, both IV and oral administration of MTX-DOX NP showed superior activity (~3 fold) over free DOX in reactivation of p53 in OSCC (p<0.000). The effectiveness of oral route in group treated with nanodrug accounts for the enhanced bioavailability of nanoparticulated DOX- MTX compared to free DOX. Moreover, in treated groups, tumor stage was markedly related to the amount of p53 mRNA (p<0.05).

CONCLUSION

Both oral and IV application of our novel nanodrug possesses superior activity over free DOX-in up-regulation of p53 in a OSCC model and this increase in p53 level associated with less aggressive tumors in our study. Although, impressive results obtained with IV form of nanodrug (-21 fold increase in p53 mRNA level) but both forms of nanodrug are effective in OSCC, with less toxicity normal cells.

Novel nanoliposomal delivery system for polydatin: preparation, characterization, and in vivo evaluation

Background

The objective of this study was to develop a novel polydatin (PLD)-loaded liposome system using the thin film hydration technique.

Methods

The delivery system was characterized in terms of morphology, size, zeta potential, encapsulation efficiency, and in vitro release. In addition, a pharmacokinetic study was carried out in rats after oral administration of PLD-loaded liposomes in vivo.

Results

Transmission electron microscopy revealed that the PLD-loaded liposomes had a homogeneous size and spherical shape. Dynamic light scattering showed that the PLD-loaded liposomes had a smaller size with a mean value of 80.2±3.7 nm and a polydispersity index of 0.12±0.06. The encapsulation efficiency of the prepared liposomes was 88.4%±3.7%. During the release process, liposome showed two distinct phases. The first was characterized by rapid release during the first 2 hours, which could be related to the release of the drug adsorbed on the surface of liposomes. In the second phase, the release rate slowed down, demonstrating a typical sustained and prolonged drug-release behavior. The release kinetic model for the PLD-loaded liposomes fitted well with the Weibull distribution equation. In vivo, relative oral bioavailability of the encapsulated PLD was 282.9%, ie, significantly enhanced (P<0.05) compared with the free drug. No histological changes occurred in the organs after administration of PLD-loaded liposomes.

Conclusion

PLD-loaded liposomes could significantly prolong the drug circulation time in vivo and increase the oral bioavailability of the drug.

Improved stability and skin permeability of sodium hyaluronate-chitosan multilayered liposomes by Layer-by-Layer electrostatic deposition for quercetin delivery

Layer-by-Layer (LbL) technology, based on the electrostatic interaction of polyelectrolytes, is used to improve the stability of drug delivery systems. In the present study, we developed multilayered liposomes with up to 10 alternating layers based on LbL deposition of hyaluronate-chitosan for transdermal delivery. Dihexadecyl phosphate was used to provide liposomes with a negative charge; the liposomes were subsequently coated with cationic chitosan (CH) followed by anionic sodium hyaluronate (HA). The resulting particles had a cumulative size of 528.28±29.22nm and an alternative change in zeta potential. Differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) revealed that the multilayered liposomes formed a spherical polyelectrolyte complex (PEC) after deposition. Observations in size distribution after 1 week found that the particles coated with even layers of polyelectrolytes, hyaluronate and chitosan (HA-CH), were more stable than the odd layers. Membrane stability in the presence of the surfactant Triton X-100 increased with an increase in bilayers as compared to uncoated liposomes. An increase in the number of bilayers deposited on the liposomal surface resulted in a sustained release of quercetin, with release kinetics that fit the Korsmeyer-Peppas model. In an in vitro skin permeation study, negatively charged (HA-CH)-L and positively charged CH-L were observed to have similar skin permeability, which were superior to uncoated liposomes. These results indicate that multilayered liposomes properly coated with polyelectrolytes of HA and CH by electrostatic interaction improve stability and can also function as potential drug delivery system for the transdermal delivery of the hydrophobic antioxidant quercetin.

Biodegradable polymeric nanoparticles for oral delivery of epirubicin: In vitro, ex vivo, and in vivo investigations

Epirubicin (EPI) is an anthracycline antineoplastic agent, commercially available for intravenous administration only and its oral ingestion continues to remain a challenge. Present investigation is aimed at the development of poly-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) for oral bioavailability enhancement of epirubicin. Developed formulation revealed particle size, 235.3±15.12 nm, zeta potential, -27.5±0.7 mV and drug content (39.12±2.13 μg/mg), with spherical shape and smooth surface. Cytotoxicity studies conducted on human breast adenocarcinoma cell lines (MCF-7) confirmed the superiority of epirubicin loaded poly-lactic-co-glycolic acid nanoparticles (EPI-NPs) over free epirubicin solution (EPI-S). Further, flow cytometric analysis demonstrated improved drug uptake through EPI-NPs and elucidated the dominance of caveolae mediated endocytosis for nanoparticles uptake. Transport study accomplished on human colon adenocarcinoma cell line (Caco-2) showed 2.76 fold improvement in permeability for EPI-NPs as compared to EPI-S (p<0.001) whereas a 4.49 fold higher transport was observed on rat ileum; a 1.8 fold higher (p<0.01) in comparison to Caco-2 cell lines which confirms the significant role of Peyer's patches in absorption enhancement. Furthermore, in vivo pharmacokinetic studies also revealed 3.9 fold improvement in oral bioavailability of EPI through EPI-NPs. Henceforth, EPI-NPs is a promising approach to replace pre-existing intravenous therapy thus providing "patient care at home".

Improved oral absorption of doxorubicin by amphiphilic copolymer of lysine-linked ditocopherol polyethylene glycol 2000 succinate: in vitro characterization and in vivo evaluation

In the previous study, we have synthesized an amphiphilic copolymer of nanostructure-forming material and P-glycoprotein (P-gp) inhibitor, lysine-linked ditocopherol polyethylene glycol 2000 succinate (PLV2K). The cytotoxicty in vitro and anticancer efficacy in vivo after intravenous administration of DOX-loaded PLV2K micelles (PLV2K-DOX) was found more effective than DOX solution (DOX-Sol). However, its performance and mechanism on oral absorption of doxorubicin are not well understood yet. PLV2K-DOX are spherical micelles with a narrow size distribution of 20.53 ± 2.44 nm. With an in situ intestinal perfusion model, the intestinal absorption potential of PLV2K-DOX was evaluated in comparison with DOX-Sol. PLV2K-DOX was specifically absorbed in duodenum and ileum sites of rats after oral administration. The intestinal absorption rate (Ka) of PLV2K-DOX is 3.19-, 1.61-, and 1.80-fold higher than that of DOX-Sol in duodenum, jejunum, and ileum, respectively. In Caco-2 uptake studies, PLV2K-DOX micelles significantly improve the internalized amount of DOX by P-gp inhibition of free PLV2K copolymer and endocytosis of DOX-loaded nanoparticles. Moreover, PLV2K-DOX micelles improve the membrane permeability of DOX by multiple transcytosis mechanisms, including caveolin-, clathrin-dependent, and caveolin-/clathrin-independent transcytosis in Caco-2 transport studies. However, the transepithelia electrical resistance (TEER) of Caco-2 cellular monolayer is not changed, suggesting no involvement of paracellular transport of PLV2K-DOX. In vivo pharmacokinetics in rats following oral administration demonstrated that PLV2K-DOX demonstrates higher AUC (5.6-fold) and longer t1/2 (1.2-fold) than DOX-Sol. The findings suggest the new PLV2K micelles might provide an effective nanoplatform for oral delivery of anticancer drugs with poor membrane permeability and low oral bioavailability.

Improved oral bioavailability of docetaxel by nanostructured lipid carriers: in vitro characteristics, in vivo evaluation and intestinal transport studies

The objective of the current study was to explore the potential of nanostructured lipid carriers (NLC) for oral delivery of docetaxel (DTX) and investigate the absorption mechanismin vivo.

A poly-l-glutamic acid functionalized nanocomplex for improved oral drug absorption

A PGA-based complex enhanced intestinal absorption due to the improved active epithelial endocytosis through specific interactions with epithelium-bound γ-GT.

Folate appended chitosan nanoparticles augment the stability, bioavailability and efficacy of insulin in diabetic rats following oral administration

The present study embarks upon the folic acid (FA) functionalization of chitosan nanoparticles and its implications on stability, oral bioavailability and hypoglycemic activity following oral administration.

Hyaluronic acid–PEI–cyclodextrin polyplexes: implications for in vitro and in vivo transfection efficiency and toxicity

The present study reveals novel HA–PEI–CyD polyplexes as non-viral vectors for gene delivery.

Rationally developed core–shell polymeric-lipid hybrid nanoparticles as a delivery vehicle for cromolyn sodium: implications of lipid envelop on in vitro and in vivo behaviour of nanoparticles upon oral administration

In the present study, cromolyn sodium, a highly water soluble molecule was encapsulated into rationally designed, core–shell polymeric-lipid hybrid nanoparticles for enhancing its oral bioavailability, by improving its intestinal permeability.

Enhanced transport of nanocage stabilized pure nanodrug across intestinal epithelial barrier mimicking Listeria monocytogenes

Ligand grafted nanoparticles have been shown to enhance drug transport across epithelium barrier and are expected to improve drug delivery. However, grafting of these ligands to the surface of pure nanodrug, i.e., nanocrystals (NCs), is a critical challenge due to the shedding of ligands along with the stabilizer upon high dilution or dissolving of the drug. Herein, a non-sheddable nanocage-like stabilizer was designed by covalent cross-linking of poly(acrylic acid)-b-poly(methyl acrylate) on drug nanocrystal surface, and a ligand, wheat germ agglutinin (WGA), was successfully anchored to the surface of itraconazole (ITZ) NCs by covalent conjugation to the nanocage (WGA-cage-NCs). The cellular study showed that large amount of WGA-cage-NCs were adhered to Caco-2 cell membrane, and invaded into cells, resulting in a higher drug uptake than that of ordinary NCs (ONCs). After oral administration to rats, WGA-cage-NC were largely accumulated on the apical side of epithelium cells, facilitating drug diffusing across epithelium barrier. Interestingly, WGA-cage-NCs were capable of invading rat intestinal villi and reaching to lamina propria by transcytosis across goblet cells, which behaved like a foodborne pathogen, Listeria monocytogenes. The WGA-cage-NCs showed an improved oral bioavailability, which was 17.5- and 2.41-folds higher than that of coarse crystals and ONCs, respectively. To our best knowledge, this may represent the first report that a functional ligand was successfully anchored to the surface of pure nanodrug by using a cage-like stabilizer, showing unique biological functions in gastrointestinal tract and having an important significance in oral drug delivery.

Chitosan-coated nano-liposomes for the oral delivery of berberine hydrochloride

Berberine hydrochloride (BH) possesses various pharmacological properties including anticancer; unfortunately, it has low oral bioavailability and potential side effects for its parenteral administration. Nanoscale delivery carriers can increase the oral bioavailability of BH. Chitosan has interesting biopharmaceutical properties such as nontoxicity, biocompatibility, biodegradability, and mucoadhesiveness, and the ability to open epithelial tight junctions. This study aims to engineer a chitosan-coated nano-liposomal carrier for the oral delivery of BH. The engineered formulation had a size in the nanoscale range. Chitosan-coated nano-liposomes displayed better stability and slower BH release in the simulated gastrointestinal (GI) environment as compared to the uncoated ones. All values of pharmacokinetic analysis for chitosan-coated nano-liposomes were higher than for uncoated ones. These findings demonstrate that chitosan-coated nano-liposomes are more efficient than uncoated ones for the oral delivery of BH. It can be concluded that the stability and delayed BH release in the simulated GI environment were improved with engineered chitosan-coated nano-liposomes. Moreover, since desirable in vitro and in vivo characteristics were achieved, they are promising release devices for the oral delivery of BH increasing the bioavailability of the drug.

Preparation, pharmacokinetics and biodistribution of baicalin-loaded liposomes

Baicalin (BA) is a major constituent of Scutellaria baicalensis Georgi, a medicinal herb. Previous pharmacokinetic studies of BA showed its low oral bioavailability. The aim of the present study was to develop a novel BA-loaded liposome (BA-LP) to enhance oral bioavailability. BA-LP, composed of BA, Tween(®) 80, Phospholipon(®) 90H, and citric acid at weight ratio of 96/50/96/50, respectively, was prepared by the effervescent dispersion technique and characterized in terms of morphology, size, zeta potential, encapsulation efficiency, and the in vitro release. Pharmacokinetics and biodistribution studies were carried out in rats after oral administration of BA-LP and a carboxymethyl cellulose suspension containing BA (BA-CMC) as a control. BA-LP exhibited a spherical shape by transmission electron microscopy observation. BA-LP had a mean particle size of 373±15.5 nm, zeta potential of -20.1±0.22 mV, and encapsulation efficiency of 82.7%±0.59%. The BA-LP showed a sustained-release behavior, and the in vitro drug-release kinetic model fit well with the Weibull distribution equation: lnln (1/(1-Q)) =0.609 lnt -1.230 (r=0.995). The oral bioavailability and the peak concentration of the BA-LP was threefold and 2.82-fold that of BA-CMC, respectively. The in vivo distribution results indicated that drug concentrations were significantly increased in the liver, kidney, and lung in the case of BA-LP, which were 5.59-fold, 2.33-fold, and 1.25-fold higher than those of BA-CMC, respectively. In conclusion, the study suggested that BA-LP might be a potential oral drug delivery system to improve bioavailability of BA.

Nanoparticles in drug delivery: mechanism of action, formulation and clinical application towards reduction in drug-associated nephrotoxicity

INTRODUCTION

Over the past few decades, nanoparticles (NPs) have gained immeasurable interest in the field of drug delivery. Various NP formulations have been disseminated in drug development in an attempt to increase efficacy, safety and tolerability of incorporated drugs. In this context, NP formulations that increase solubility, control release, and/or affect the in vivo disposition of drugs, were developed to improve the pharmacokinetic and pharmacodynamic properties of encapsulated drugs.

AREAS COVERED

In this article, important properties related to NP function such as particle size, surface charge and shape are disseminated. Also, the current understanding of how NP characteristics affect particle uptake and targeted delivery is elucidated. Selected NP systems currently used in delivery of drugs in biological systems and their production methods are discussed as well. Emphasis is placed on current NP formulations that are shown to reduce drug-induced adverse renal complications.

EXPERT OPINION

Formulation designs utilizing NP-encapsulated drugs offer alternative pharmacotherapy options with improved safety profiles for current and emerging drugs. NPs have been shown to increase the therapeutic index of several entrapped drugs mostly by decreasing drug localization and side effects on organs. Recent studies on NP-encapsulated chemotherapeutic and antibiotic medications show enhanced therapeutic outcomes by altering drug degradation, increasing systemic circulation and/or enhancing cell specific targeting. They may also reduce the distribution of encapsulated drugs into the kidneys and attenuate drug-associated adverse renal complications. The usefulness of NP formulation in reducing the nephrotoxicity of nonsteroidal anti-inflammatory drugs is an under explored territory that deserves more attention.

Ag@4ATP-coated liposomes: SERS traceable delivery vehicles for living cells

A liposome-Ag nanohybrid has been demonstrated as a SERS traceable intracellular drug nanocarrier. Liposomes have been introduced for their special qualities in drug delivery systems. In essence, 4-aminothiophenol (4ATP) tagged Ag nanoparticles (Ag@4ATP) were adsorbed onto the surfaces of liposomes via electrostatic interactions, in which 4ATP was used as a SERS reporter. In such a nanohybrid, the locations of the carrier can be tracked by SERS signals while those of the drugs can be monitored through their fluorescence, allowing the simultaneous investigation of the intracellular distribution of both the carriers and the drugs. Our experimental results suggest that the reported liposomal system has substantial potential for intracellular drug delivery.

Microfluidics fabrication of monodisperse biocompatible phospholipid vesicles for encapsulation and delivery of hydrophilic drug or active compound

We encapsulate the hydrophilic anti-cancer drug doxurubicin hydrochloride (DOX) with about 94% drug encapsulation efficiency, either alone or with nanomagnetite, in monodisperse biocompatible phospholipid vesicles. Glass capillary microfluidics is used to generate monodisperse water in oil in water (w/o/w) double-emulsion templates with a core-shell structure by using a mixture of liquid unsaturated phospholipids and powdered saturated phospholipid. This combination would overcome the low transition temperature of unsaturated powdered phospholipid and the solubility limitation of saturated phospholipid, as well as improving the fabrication of stable monodisperse phospholipid vesicles. The double-emulsion droplet is controlled from 50 to 200 μm according to different flow rates, and the final phospholipid vesicles are retained after a solvent removal step by dewetting. DOX-loaded phospholipid vesicles show sustained release compared with free DOX water solution. The in vitro cell viability of 100 μg/mL phospholipid vesicles on HeLa or MCF-7 cells after 24 h incubation at 310 K is above 90%, confirming the excellent biocompatibility of the phospholipid vesicles. These biocompatible phospholipid vesicles are promising oral drug delivery vehicles for biomedical applications and magnetic resonance imaging contrast agents for biomedical diagnosis.