Intestinal permeation enhancement of docetaxel encapsulated into methyl-β-cyclodextrin/poly(isobutylcyanoacrylate) nanoparticles coated with thiolated chitosan

Surface engineering of chitosan nanosystems and the impact of functionalized groups on the permeability of model drug across intestinal tissue

Surface attributes of nanocarriers are crucial to determine their fate in the gastrointestinal (GI) tract. Herein, we have functionalized chitosan with biochemical moieties including rhamnolipid (RL), curcumin (Cur) and mannose (M). FTIR spectra of functionalized chitosan nanocarriers (FCNCs) demonstrated successful conjugation of M, Cur and RL. The functional moieties influenced the entrapment of model drug i.e., coumarin-6 (C6) in FCNCs with payload-hosting and non-leaching behavior i.e., >91 ± 2.5 % with negligible cumulative release of <2 % for 5 h in KREB, which was further verified in the simulated gastric and intestinal fluids. Consequently, substantial difference in the size and zeta potential was observed for FCNCs with different biochemical moieties. Scanning electron microscopy and atomic force microscopy of FCNCs displayed well-dispersed and spherical morphology. In addition, in vitro cytotoxicity results of FCNCs confirmed their hemocompatibility. In the ex-vivo rat intestinal models, FCNCs displayed a time-dependent-phenomenon in cellular-uptake and adherence. However, apparent-permeability-coefficient and flux values were in the order of C6-RL-FCNCs > C6-M-FCNCs > C6-Cur-FCNCs = C6-CNCs > Free-C6. Furthermore, the transepithelial electrical resistance revealed the FCNCs mediated recovery of membrane-integrity with reversible tight junctions opening. Thus, FCNCs have the potential to overcome the poor solubility and/or permeability issues of active pharmaceutical ingredients and transform the impact of functionalized-nanomedicines in the biomedical industry.

Orally administered docetaxel-loaded chitosan-decorated cationic PLGA nanoparticles for intestinal tumors: formulation, comprehensive in vitro characterization, and release kinetics

Intestinal cancers are the third most lethal cancers globally, beginning as polyps in the intestine and spreading with a severe metastatic tendency. Chemotherapeutic drugs used in the treatment of intestinal tumors are usually formulated for parenteral administration due to poor solubility and bioavailability problems. Pharmaceutically, clinical failure due to a drug's wide biodistribution and non-selective toxicity is one of the major challenges of chemotherapy. In addition, parenteral drug administration in chronic diseases that require long-term drug use, such as intestinal tumors, is challenging in terms of patient compliance and poses a burden in terms of health economy. Especially in the field of chemotherapy research, oral chemotherapy is a subject that has been intensively researched in recent years, and developments in this field will provide serious breakthroughs both scientifically and socially. Development of orally applicable nanodrug formulations that can act against diseases seen in the distant region of the gastrointestinal tract (GIT), such as intestinal tumor, brings with it a series of difficulties depending on the drug and/or GIT physiology. The aim of this study is to develop an oral nanoparticle drug delivery system loaded with docetaxel (DCX) as an anticancer drug, using poly(lactic-co-glycolic acid) (PLGA) as nanoparticle material, and modified with chitosan (CS) to gain mucoadhesive properties. In this context, an innovative nanoparticle formulation that can protect orally administered DCX from GIT conditions and deliver the drug to the intestinal tumoral region by accumulating in mucus has been designed. For this purpose, DCX-PLGA nanoparticles (NPs) and CS/DCX-PLGA NPs were prepared, and their in vitro characteristics were elucidated. Nanoparticles around 250-300 nm were obtained. DCX-PLGA NPs had positive surface charge with CS coating. The formulations have the potential to deliver the encapsulated drug to the bowel according to the in vitro release studies in three different simulated GIT fluids for approximately 72 h. Mucin interaction and penetration into the artificial mucus layer were also investigated in detail, and the mucoadhesive and mucus-penetration characteristics of the formulations were examined. Furthermore, in vitro release kinetic studies of the NPs were elucidated. DCX-PLGA NPs were found to be compatible with the Weibull model, and CS/DCX-PLGA NPs were found to be compatible with the Peppas-Sahlin model. Within the scope of in vitro cytotoxicity studies, the drug-loaded NPs showed significantly higher cytotoxicity than a DCX solution on the HT-29 colon cell line, and CS/DCX-PLGA showed the highest cytotoxicity (p < 0.05). According to the permeability studies on the Caco-2 cell line, the CS/DCX-PLGA formulation increased permeability by 383% compared to free DCX (p < 0.05). In the light of all results, CS/DCX-PLGA NPs can offer a promising and innovative approach as an oral anticancer drug-loaded nanoformulation for intestinal tumors.

Pushing the Limits on the Intestinal Crossing of Metal-Organic Frameworks: An Ex Vivo and In Vivo Detailed Study

Biocompatible nanoscaled metal-organic frameworks (nanoMOFs) have been widely studied as drug delivery systems (DDSs), through different administration routes, with rare examples in the convenient and commonly used oral administration. So far, the main objective of nanoMOFs as oral DDSs was to increase the bioavailability of the cargo, without considering the MOF intestinal crossing with potential advantages (e.g., increasing drug availability, direct transport to systemic circulation). Thus, we propose to address the direct quantification and visualization of MOFs' intestinal bypass. For that purpose, we select the microporous Fe-based nanoMOF, MIL-127, exhibiting interesting properties as a nanocarrier (great biocompatibility, large porosity accessible to different drugs, green and multigram scale synthesis, outstanding stability along the gastrointestinal tract). Additionally, the outer surface of MIL-127 was engineered with the biopolymer chitosan (CS@MIL-127) to improve the nanoMOF intestinal permeation. The biocompatibility and intestinal crossing of nanoMOFs is confirmed using a simple and relevant in vivo model, Caenorhabditis elegans; these worms are able to ingest enormous amounts of nanoMOFs (up to 35 g per kg of body weight). Finally, an ex vivo intestinal model (rat) is used to further support the nanoMOFs' bypass across the intestinal barrier, demonstrating a fast crossing (only 2 h). To the best of our knowledge, this report on the intestinal crossing of intact nanoMOFs sheds light on the safe and efficient application of MOFs as oral DDSs.

Shape stability of ellipsoidal nanomaterials prepared by physical deformation

The nonspherical shape of nanomaterials (NMs) represents a key attribute for controlling their biological behaviors. Analyzing shape stability over time represents a significant concern because nonspherical NMs are likely to rearrange into a thermodynamically more stable spherical shape. In this investigation, ellipsoidal NMs were designed by physical deformation of core/shell nanospheres composed of poly(isobutylcyanoacrylate) and chitosan or a mixture of chitosan and thiolated chitosan. After optimizing the process parameters for designing ellipsoidal NMs, the shape stability during storage was investigated for 6 months at different temperatures (4 °C, 20 °C and 40 °C). The NM shape was examined by analyzing the aspect ratio from images obtained by electron microscopy techniques. The results demonstrated the feasibility of designing shape-persistent ellipsoidal NMs by physical deformation of spherical particles.

Real-time visualization of morphology-dependent self-motion of hyaluronic acid nanomaterials in water

Drug delivery to target sites is often limited by inefficient particle transport through biological media. Herein, motion behaviors of spherical and nonspherical nanomaterials composed of hyaluronic acid were studied in water using real-time multiple particle tracking technology. The two types of nanomaterials have comparable surface compositions and surface potentials, and they have equivalent diameters. The analysis of nanomaterial trajectories revealed that particles with flattened morphology and a high aspect ratio, designated nanoplatelets, exhibited more linear trajectories and faster diffusion in water than nanospheres. Fitting the plots of mean square displacement vs. time scale suggests that nanoplatelets exhibited hyperdiffusive behavior, which is similar to the motion of living microorganisms. Furthermore, at 37 °C, the surface explored by a nanoplatelet was up to 33-fold higher than that explored by a nanosphere. This investigation on morphology-dependent self-motion of nanomaterials could have a significant impact on drug delivery applications by increasing particle transport through biological media.

An overview of in vitro, ex vivo and in vivo models for studying the transport of drugs across intestinal barriers

Oral administration is the most commonly used route for drug delivery owing to its cost-effectiveness, ease of administration, and high patient compliance. However, the absorption of orally delivered compounds is a complex process that greatly depends on the interplay between the characteristics of the drug/formulation and the gastrointestinal tract. In this contribution, we review the different preclinical models (in vitro, ex vivo and in vivo) from their development to application for studying the transport of drugs across intestinal barriers. This review also discusses the advantages and disadvantages of each model. Furthermore, the authors have reviewed the selection and validation of these models and how the limitations of the models can be addressed in future investigations. The correlation and predictability of the intestinal transport data from the preclinical models and human data are also explored. With the increasing popularity and prevalence of orally delivered drugs/formulations, sophisticated preclinical models with higher predictive capacity for absorption of oral formulations used in clinical studies will be needed.

Molecular and cellular cues governing nanomaterial-mucosae interactions: from nanomedicine to nanotoxicology

Mucosal tissues constitute the largest interface between the body and the surrounding environment and they regulate the access of molecules, supramolecular structures, particulate matter, and pathogens into it. All mucosae are characterized by an outer mucus layer that protects the underlying cells from physicochemical, biological and mechanical insults, a mono-layered or stratified epithelium that forms tight junctions and controls the selective transport of solutes across it and associated lymphoid tissues that play a sentinel role. Mucus is a gel-like material comprised mainly of the glycoprotein mucin and water and it displays both hydrophilic and hydrophobic domains, a net negative charge, and high porosity and pore interconnectivity, providing an efficient barrier for the absorption of therapeutic agents. To prolong the residence time, absorption and bioavailability of a broad spectrum of active compounds upon mucosal administration, mucus-penetrating and mucoadhesive particles have been designed by tuning the chemical composition, the size, the density, and the surface properties. The benefits of utilizing nanomaterials that interact intimately with mucosae by different mechanisms in the nanomedicine field have been extensively reported. To ensure the safety of these nanosystems, their compatibility is evaluated in vitro and in vivo in preclinical and clinical trials. Conversely, there is a growing concern about the toxicity of nanomaterials dispersed in air and water effluents that unintentionally come into contact with the airways and the gastrointestinal tract. Thus, deep understanding of the key nanomaterial properties that govern the interplay with mucus and tissues is crucial for the rational design of more efficient drug delivery nanosystems (nanomedicine) and to anticipate the fate and side-effects of nanoparticulate matter upon acute or chronic exposure (nanotoxicology). This review initially overviews the complex structural features of mucosal tissues, including the structure of mucus, the epithelial barrier, the mucosal-associated lymphatic tissues and microbiota. Then, the most relevant investigations attempting to identify and validate the key particle features that govern nanomaterial-mucosa interactions and that are relevant in both nanomedicine and nanotoxicology are discussed in a holistic manner. Finally, the most popular experimental techniques and the incipient use of mathematical and computational models to characterize these interactions are described.

Self-Assembly of Amphiphilic Compounds as a Versatile Tool for Construction of Nanoscale Drug Carriers

This review focuses on synthetic and natural amphiphilic systems prepared from straight-chain and macrocyclic compounds capable of self-assembly with the formation of nanoscale aggregates of different morphology and their application as drug carriers. Since numerous biological species (lipid membrane, bacterial cell wall, mucous membrane, corneal epithelium, biopolymers, e.g., proteins, nucleic acids) bear negatively charged fragments, much attention is paid to cationic carriers providing high affinity for encapsulated drugs to targeted cells. First part of the review is devoted to self-assembling and functional properties of surfactant systems, with special attention focusing on cationic amphiphiles, including those bearing natural or cleavable fragments. Further, lipid formulations, especially liposomes, are discussed in terms of their fabrication and application for intracellular drug delivery. This section highlights several features of these carriers, including noncovalent modification of lipid formulations by cationic surfactants, pH-responsive properties, endosomal escape, etc. Third part of the review deals with nanocarriers based on macrocyclic compounds, with such important characteristics as mucoadhesive properties emphasized. In this section, different combinations of cyclodextrin platform conjugated with polymers is considered as drug delivery systems with synergetic effect that improves solubility, targeting and biocompatibility of formulations.

Therapeutic potential of phenylethanoid glycosides: A systematic review

Phenylethanoid glycosides (PhGs) are generally water-soluble phenolic compounds that occur in many medicinal plants. Until June 2020, more than 572 PhGs have been isolated and identified. PhGs possess antibacterial, anticancer, antidiabetic, anti-inflammatory, antiobesity, antioxidant, antiviral, and neuroprotective properties. Despite these promising benefits, PhGs have failed to fulfill their therapeutic applications due to their poor bioavailability. The attempts to understand their metabolic pathways to improve their bioavailability are investigated. In this review article, we will first summarize the number of PhGs compounds which is not accurate in the literature. The latest information on the biological activities, structure-activity relationships, mechanisms, and especially the clinical applications of PhGs will be reviewed. The bioavailability of PhGs will be summarized and factors leading to the low bioavailability will be analyzed. Recent advances in methods such as bioenhancers and nanotechnology to improve the bioavailability of PhGs are also summarized. The existing scientific gaps of PhGs in knowledge are also discussed, highlighting research directions in the future.

Thiolated Chitosans: A Multi-talented Class of Polymers for Various Applications

Various properties of chitosan can be customized by thiolation for very specific needs in a wide range of application areas. Since the discovery of thiolated chitosans, many studies have proven their advantageous characteristics, such as adhesion to biological surfaces, adjustable cross-linking and swelling behavior, controllable drug release, permeation as well as cellular uptake enhancement, inhibition of efflux pumps and enzymes, complexation of metal ions, antioxidative properties, and radical scavenging activity. Simultaneously, these polymers remain biodegradable without increased toxicity. Within this Review, an overview about the different possibilities to covalently attach sulfhydryl ligands to the polymeric backbone of chitosan is given, and the resulting versatile physiochemical properties are discussed in detail. Furthermore, the broad spectrum of applications for thiolated chitosans in science and industry, ranging from their most advanced use in pharmaceutical and medical science over wastewater treatment to the impregnation of textiles, is addressed.

Cyclodextrin nanoparticle bound oral camptothecin for colorectal cancer: Formulation development and optimization

Chemotherapeutic drugs for colorectal cancer(CRC) which is currently the third most lethal cancer globally, are administered intravenously (iv) due to their low oral bioavailability resulting from their physicochemical properties. Non-selective biodistribution and difficulties of parenteral administration reduce treatment efficacy. The aim of this work is to develop cyclodextrin (CD) based cationic nanoparticles (NPs) for CRC treatment with model drug camptothecin (CPT) that can be administered orally, protecting CPT through gastrointestinal tract (GIT), accumulating at mucus layer and providing an effective local treatment for the tumor area. NPs using two different amphiphilic CDs were prepared and coated with polyethylenimine (PEI) or chitosan (CS) to obtain positively charged surface for all formulations. Pre-formulation studies resulted in optimal formulation, CPT loaded Poly-β-CD-C6 NPs, with 135 nm diameter and zeta potential of + 40 mV. In vitro release study was designed to represent gastrointestinal pH and transit time revealing 52% of encapsulated CPT successfully delivered all the way to simulated colon. CPT bound to Poly-β-CD-C6 NPs exhibited higher cytotoxicity on HT-29 cells compared to equivalent CPT in solution. Caco-2 cell permeability studies showed 276% increase in CPT permeability and significantly higher mucosal penetration in cationic CD nanoparticle form.

Chitosan-based advanced materials for docetaxel and paclitaxel delivery: Recent advances and future directions in cancer theranostics

Paclitaxel (PTX) and docetaxel (DTX) are key members of taxanes with high anti-tumor activity against various cancer cells. These chemotherapeutic agents suffer from a number of drawbacks and it seems that low solubility in water is the most important one. Although much effort has been made in improving the bioavailability of PTX and DTX, the low bioavailability and minimal accumulation at tumor sites are still the challenges faced in PTX and DTX therapy. As a consequence, bio-based nanoparticles (NPs) have attracted much attention due to unique properties. Among them, chitosan (CS) is of interest due to its great biocompatibility. CS is a positively charged polysaccharide with the capability of interaction with negatively charged biomolecules. Besides, it can be processed into the sheet, micro/nano-particles, scaffold, and is dissolvable in mildly acidic pH similar to the pH of the tumor microenvironment. Keeping in mind the different applications of CS in the preparation of nanocarriers for delivery of PTX and DTX, in the present review, we demonstrate that how CS functionalized-nanocarriers and CS modification can be beneficial in enhancing the bioavailability of PTX and DTX, targeted delivery at tumor site, image-guided delivery and co-delivery with other anti-tumor drugs or genes.

Nanoparticles from Gantrez® AN-poly(ethylene glycol) conjugates as carriers for oral delivery of docetaxel

The oral delivery of docetaxel (DTX) is challenging due to a low bioavailability, related to an important pre-systemic metabolism. With the aim of improving the bioavailability of this cytotoxic agent, nanoparticles from conjugates based on the copolymer of methyl vinyl ether and maleic anhydride (poly(anhydride)) and two different types of PEG, PEG2000 (PEG2) or methoxyPEG2000 (mPEG2), were evaluated. Nanoparticles, with a DTX loading close to 10%, were prepared by desolvation and stabilized with calcium, before purification and lyophilization. For the pharmacokinetic study, nanoparticles were orally administered to mice at a single dose of 30 mg/kg. The plasma levels of DTX were high, prolonged in time and, importantly, quantified within the therapeutic window. The relative oral bioavailability was calculated to be up to 56% when DTX was loaded in nanoparticles from poly(anhydride)-mPEG2000 conjugate (DTX-NP-mPEG2). Finally, a comparative toxicity study between equitoxic doses of free iv DTX and oral DTX-NP-mPEG2 was conducted in mice. Animals orally treated with DTX-loaded nanoparticles displayed less severe signs of hypersensitivity reactions, peripheral neurotoxicity, myelosuppression and hepatotoxicity than free iv docetaxel. In summary, poly(anhydride)-PEG conjugate nanoparticles appears to be adequate carries for the oral delivery of docetaxel.

Vascular targeted chitosan-derived nanoparticles as docetaxel carriers for gastric cancer therapy

A gastric cancer angiogenesis marker peptide, GX1, is promising to be a desirable ligand for anti-angiogenesis targeted drug of gastric cancer treatment. In this study, GX1 was utilized to fabricate a multifunctional vascular targeting docetaxel (DCT)-loaded nanoparticle with N-deoxycholic acid glycol chitosan (DGC) as the carrier and GX1-PEG-deoxycholic acid (GPD) conjugate as the targeting ligand. The mean size of obtained GX1-DGC-DCT was 150.9 nm with a narrow size distribution and their shape was spherical with smooth surface texture. The in vitro drug release test revealed a sustained release manner and an acid pH could accelerate the release compared with the neutral pH. Furthermore, GX1-DGC-DCT showed stronger cytotoxicity against co-cultured gastric cancer cells and human umbilical vein endothelial cells (co-HUVEC) than DCT within 100 μM. In addition, GX1 efficiently enhanced the cellular uptake of nanoparticles in co-HUVEC cells as confirmed by confocal fluorescence scanning microscopy. Moreover, in vivo delivery of GX1-DGC-DCT was demonstrated to inhibit tumor growth in SGC791 tumor-bearing mice with tumor inhibition rate (TIR) of 67.05% and no weight loss of mice was observed. The anti-tumor effects were further confirmed by H&E and TUNEL analysis. Therefore, this new drug delivery system represents a potential strategy for gastric cancer therapy.

Interactions Between Emodin and Efflux Transporters on Rat Enterocyte by a Validated Ussing Chamber Technique

Emodin, a major active anthraquinone, frequently interacts with other drugs. As changes of efflux transporters on intestine are one of the essential reasons why the drugs interact with each other, a validated Ussing chamber technique was established to detect the interactions between emodin and efflux transporters, including P-glycoprotein (P-gp), multidrug-resistant associated protein 2 (MRP2), and multidrug-resistant associated protein 3 (MRP3). Digoxin, pravastatin, and teniposide were selected as the test substrates of P-gp, MRP2, and MRP3. Verapamil, MK571, and benzbromarone were their special inhibitors. The results showed that verapamil, MK571, and benzbromarone could increase digoxin, pravastatin, and teniposide absorption, and decrease their E_r values, respectively. Verapamil (220 μM) could significantly increase emodin absorption at 9.25 μM. In the presence of MK571 (186 μM), the P_app values of emodin from M-S were significantly increased and the efflux ratio decreased. With the treatment of emodin (185, 370, and 740 μM), digoxin absorption was significantly decreased while teniposide increased. These results indicated that emodin might be the substrate of P-gp and MRP2. Besides, it might be a P-gp inducer and MRP3 inhibitor on enterocyte, which are reported for the first time. These results will be helpful to explain the drug–drug interaction mechanisms between emodin and other drugs and provide basic data for clinical combination therapy.

Advancements in the oral delivery of Docetaxel: challenges, current state-of-the-art and future trends

The oral delivery of cancer chemotherapeutic drugs is challenging due to low bioavailability, gastrointestinal side effects, first-pass metabolism and P-glycoprotein efflux pumps. Thus, chemotherapeutic drugs, including Docetaxel, are administered via an intravenous route, which poses many disadvantages of its own. Recent advances in pharmaceutical research have focused on designing new and efficient drug delivery systems for site-specific targeting, thus leading to improved bioavailability and pharmacokinetics. A decent number of studies have been reported for the safe and effective oral delivery of Docetaxel. These nanocarriers, including liposomes, polymeric nanoparticles, metallic nanoparticles, hybrid nanoparticles, dendrimers and so on, have shown promising results in research papers and clinical trials. The present article comprehensively reviews the research efforts made so far in designing various advancements in the oral delivery of Docetaxel. Different strategies to improve oral bioavailability, prevent first-pass metabolism and inhibition of efflux pumping leading to improved pharmacokinetics and anticancer activity are discussed. The final portion of this review article presents key issues such as safety of nanomaterials, regulatory approval and future trends in nanomedicine research.

Development of keratin nanoparticles for controlled gastric mucoadhesion and drug release

Background

Nanotechnology-based drug delivery systems have been widely used for oral and systemic dosage forms delivery depending on the mucoadhesive interaction, and keratin has been applied for biomedical applications and drug delivery. However, few reports have focused on the keratin-based mucoadhesive drug delivery system and their mechanisms of mucoadhesion. Thus, the mucoadhesion controlled kerateine (reduced keratin, KTN)/keratose (oxidized keratin, KOS) composite nanoparticles were prepared via adjusting the proportion of KTN and KOS to achieve controlled gastric mucoadhesion and drug release based on their different mucoadhesive abilities and pH-sensitive properties. Furthermore, the mechanisms of mucoadhesion for KTN and KOS were also investigated in the present study.

Results

The composite keratin nanoparticles (KNPs) with different mass ratio of KTN to KOS, including 100/0 (KNP-1), 75/25 (KNP-2), 50/50 (KNP-3), and 25/75 (KNP-4), displayed different drug release rates and gastric mucoadhesion capacities, and then altered the drug pharmacokinetic performances. The stronger mucoadhesive ability of nanoparticle could supply longer gastric retention time, indicating that KTN displayed a stronger mucoadhesion than that of KOS. Furthermore, the mechanisms of mucoadhesion for KTN and KOS at different pH conditions were also investigated. The binding between KTN and porcine gastric mucin (PGM) is dominated by electrostatic attractions and hydrogen bondings at pH 4.5, and disulfide bonds also plays a key role in the interaction at pH 7.4. While, the main mechanisms of KOS and PGM interactions are hydrogen bondings and hydrophobic interactions in pH 7.4 condition and were hydrogen bondings at pH 4.5.

Conclusions

The resulting knowledge offer an efficient strategy to control the gastric mucoadhesion and drug release of nano drug delivery systems, and the elaboration of mucoadhesive mechanism of keratins will enable the rational design of nanocarriers for specific mucoadhesive drug delivery.

Electronic supplementary material

The online version of this article (10.1186/s12951-018-0353-2) contains supplementary material, which is available to authorized users.

Co-Assembly of Heparin and Polypeptide Hybrid Nanoparticles for Biomimetic Delivery and Anti-Thrombus Therapy

Biomimetic delivery carriers using polypeptide/heparin hybrid nanoparticles that are adsorbed onto red blood cells for extended blood circulation time have been developed. This might open up an avenue to promote the innovations and advances of biomimetic, stimuli-responsive drug delivery, especially for the site-specific treatment of intravascular diseases such as thrombosis.

Enhancement of absorption and bioavailability of echinacoside by verapamil or clove oil

Purpose

This present study investigated the absorption kinetics of echinacoside (ECH) in situ and in vitro and its oral bioavailability in rats. Additional aim was to find an agent(s) to promote ECH absorption and oral bioavailability among two efflux proteins and three absorption promoters.

Methods

ECH absorption behaviors were investigated by everted gut sac model in vitro and single-pass intestinal perfusion model in situ. Pharmacokinetics study was performed to investigate the influences of verapamil and clove oil on ECH bioavailability in vivo. All samples were measured at different time intervals by high performance liquid chromatography.

Results

The results showed that the effective permeability coefficient (P_eff) and apparent permeability coefficient of ECH were 0.83×10⁻⁶–3.23×10⁻⁶ cm/s and 2.99×10⁻⁶–9.86×10⁻⁶ cm/s, respectively. The P_eff among duodenum, jejunum, and ileum were not statistically different, but they were higher than colon (P<0.01), which demonstrated that intestinal ECH absorption was poor and site dependent. Additionally, verapamil and clove oil significantly increased the jejunal P_eff of ECH both in situ and in vitro. Moreover, the bioavailability of ECH in combination with verapamil and clove oil were increased by 1.37-fold (P<0.05) and 2.36-fold (P<0.001), respectively, when compared to ECH group. Overall, verapamil and clove oil facilitated ECH absorption and oral bioavailability.

Conclusion

The absorption and bioavailability of ECH were enhanced by verapamil and clove oil, respectively, both in vitro and in vivo. Consequently, the combination of verapamil and clove oil with ECH will be a promising and effective approach to promote intestinal absorption and oral bioavailability of ECH.

Preparation and therapeutic application of docetaxel-loaded poly(d,l-lactide) nanofibers in preventing breast cancer recurrence

The aim of this study was to develop docetaxel (DTX)-loaded poly-d,l-lactide (PDLLA) nanofibers and evaluate their therapeutic effect in preventing local breast cancer recurrence. DTX was incorporated into biodegradable PDLLA nanofibers by electrospinning. The surface morphology of the DTX/PDLLA nanofibers was characterized using scanning electron microscopy and wide angle X-ray diffraction. The in vitro release behavior of DTX from the fiber mats was also studied in detail. The cytotoxicity of DTX/PDLLA nanofibers was evaluated by MTT assay in 4T1 breast cancer cells. Flow cytometry revealed that DTX/PDLLA nanofibers exhibited apoptotic activity in 4T1 cells. In vivo antitumor efficacy of DTX/PDLLA nanofibers was evaluated in BALB/c mice bearing local breast tumors. Locoregional recurrence after primary tumor resection decreased obviously in mice treated with subcutaneously (16.7%) administered DTX-loaded PDLLA nanofibers, compared with the blank PDLLA nanofibers (88.9%), systemic (75.0%) or locally (77.8%) administered DTX and the control group (100%) (p < 0.05). Finally, after subcutaneous transplantation in mice, the DTX/PDLLA scaffolds presented excellent biocompatibility, as exhibited by the minimal presence of inflammatory cells in the region surrounding the scaffolds. Our results suggest that DTX/PDLLA nanofibers could have great potential for clinical application requiring local chemotherapy.

Cell line-dependent cytotoxicity of poly(isobutylcyanoacrylate) nanoparticles coated with chitosan and thiolated chitosan: Insights from cultured human epithelial HeLa, Caco2/TC7 and HT-29/MTX cells

Nanoparticles composed of poly(isobutylcyanoacrylate) core coated with a mixture of chitosan and thiolated chitosan have already shown promising results in terms of mucoadhesion and permeation enhancement properties of pharmaceutical active drugs delivered via mucosal routes. In the present work, the cytotoxicity of these nanoparticles was first investigated using direct contact assay on undifferentiated human cervix epithelial HeLa cells. The results showed strong toxicity in HeLa cells for the two investigated concentrations 25 and 50 μg/mL. The cytotoxic effect was mainly attributed to the poly(isobutylcyanoacrylate) core since no significant differences in nanoparticle cytotoxicity were reported when nanoparticle shell composition was modified by adding chitosan or thiolated chitosan. In contrast, lower nanoparticle toxicity was reported using human fully-differentiated enterocyte-like Caco-2/TC7, and fully-differentiated mucus-secreting HT-29/MTX cells forming monolayer in culture mimicking an intestinal epithelial barrier. This study demonstrated that the toxicity of poly(isobutylcyanoacrylate) nanoparticles is highly cell line-dependent.

A vision for cyclodextrin nanoparticles in drug delivery systems and pharmaceutical applications

Cyclodextrins (CDs) have brought a revolution in the pharmaceutical field over the last decade. Natural and modified CDs (α-CD and β-CD) have been studied and some have gained US FDA approval or achieved 'Generally Regarded as Safe' (GRAS) status. Another characteristic of CDs is the ease with which they can be induced to form supramolecular structures for its use in drug delivery. CDs, grafted or crosslinked with polymers, are now being developed into 'smart' systems for efficient targeted drug delivery, especially for hydrophobic drugs. Amphiphilic CDs have the ability to form nanospheres or nanocapsules via a simple nanoprecipitation technique. This review deals with different types of CDs, and their efficacy, physicochemical properties and transformation into nanoparticles with interesting in vitro and in vivo applications.

Formulation and optimization of itraconazole polymeric lipid hybrid nanoparticles (Lipomer) using Box Behnken design

Background

The objective of the study was to formulate and to investigate the combined influence of 3 independent variables in the optimization of Polymeric lipid hybrid nanoparticles (PLHNs) (Lipomer) containing hydrophobic antifungal drug Itraconazole and to improve intestinal permeability.

Method

The Polymeric lipid hybrid nanoparticle formulation was prepared by the emulsification solvent evaporation method and 3 factor 3 level Box Behnken statistical design was used to optimize and derive a second order polynomial equation and construct contour plots to predict responses. Biodegradable Polycaprolactone, soya lecithin and Poly vinyl alcohol were used to prepare PLHNs. The independent variables selected were lipid to polymer ratio (X₁) Concentration of surfactant (X₂) Concentration of the drug (X₃).

Result

The Box-Behnken design demonstrated the role of the derived equation and contour plots in predicting the values of dependent variables for the preparation and optimization of Itraconazole PLHNs. Itraconazole PLHNs revealed nano size (210 ± 1.8 nm) with an entrapment efficiency of 83 ± 0.6% and negative zeta potential of −11.7 mV and also enhance the permeability of itraconazole as the permeability coefficient (P_app) and the absorption enhancement ratio was higher.

Conclusion

The tunable particle size, surface charge, and favourable encapsulation efficiency with a sustained drug release profile of PLHNs suggesting that it could be promising system envisioned to increase the bioavailability by improving intestinal permeability through lymphatic uptake, M cell of payer’s patch or paracellular pathway which was proven by confocal microscopy.