Folate-polyethyleneimine functionalized mesoporous carbon nanoparticles for enhancing oral bioavailability of paclitaxel

Advances in oral peptide drug nanoparticles for diabetes mellitus treatment

Peptide drugs play an important role in diabetes mellitus treatment. Oral administration of peptide drugs is a promising strategy for diabetes mellitus because of its convenience and high patient compliance compared to parenteral administration routes. However, there are a series of formidable unfavorable conditions present in the gastrointestinal (GI) tract after oral administration, which result in the low oral bioavailability of these peptide drugs. To overcome these challenges, various nanoparticles (NPs) have been developed to improve the oral absorption of peptide drugs due to their unique in vivo properties and high design flexibility. This review discusses the unfavorable conditions present in the GI tract and provides the corresponding strategies to overcome these challenges. The review provides a comprehensive overview on the NPs that have been constructed for oral peptide drug delivery in diabetes mellitus treatment. Finally, we will discuss the rational application and give some suggestions that can be utilized for the development of oral peptide drug NPs. Our aim is to provide a systemic and comprehensive review of oral peptide drug NPs that can overcome the challenges in GI tract for efficient treatment of diabetes mellitus.

•Oral administration of peptide drugs is a promising strategy for diabetes mellitus treatment

•A series of formidable unfavorable conditions in gastrointestinal tract result in the low oral bioavailability of peptide drugs

•Nanoparticles can improve the oral bioavailability of peptide drugs

An updated review of mesoporous carbon as a novel drug delivery system

The nanotechnology approach has been recently adopted to provide more reliable, effective, controlled, and safe drug delivery systems. Nanostructured materials have gained great interest, including siliceous and carbonaceous nanoparticles. The effectiveness of mesoporous carbon nanoparticles (MCNs) in tumor imaging, targeting, and treatment is urging for more future studies. MCNs possess superior properties such as their biocompatibility, large surface area, large pore volume, tunability, and more responsive behavior to internal and external release triggers. These outstanding features make MCNs more applicable for stimuli-responsive drug delivery than the conventional forms of mesoporous silica nanoparticles (MSNs) and other carbon nanoparticles. In this review, we outlined the latest updates regarding the safety, benefits, and potential applications of MCNs.

Chitosan-capped enzyme-responsive hollow mesoporous silica nanoplatforms for colon-specific drug delivery

An enzyme-responsive colon-specific delivery system was developed based on hollow mesoporous silica spheres (HMSS) to which biodegradable chitosan (CS) was attached via cleavable azo bonds (HMSS-N=N-CS). Doxorubicin (DOX) was encapsulated in a noncrystalline state in the hollow cavity and mesopores of HMSS with the high loading amount of 35.2%. In vitro drug release proved that HMSS-N=N-CS/DOX performed enzyme-responsive drug release. The grafted CS could increase the biocompatibility and stability and reduce the protein adsorption on HMSS. Gastrointestinal mucosa irritation and cell cytotoxicity results indicated the good biocompatibility of HMSS and HMSS-N=N-CS. Cellular uptake results indicated that the uptake of DOX was obviously increased after HMSS-N=N-CS/DOX was preincubated with a colonic enzyme mixture. HMSS-N=N-CS/DOX incubated with colon enzymes showed increased cytotoxicity, and its IC₅₀ value was three times lower than that of HMSS-N=N-CS/DOX group without colon enzymes. The present work lays the foundation for subsequent research on mesoporous carriers for oral colon-specific drug delivery.

Efficient Oral Delivery of Poorly Water-Soluble Drugs Using Carnitine/Organic Cation Transporter 2-Mediated Polymeric Micelles

The intestine epithelium is considered to be the most critical obstacle for nanoparticles for oral delivery of water-insoluble and poorly absorbed drugs. Based on the specific transporters located on the apical membrane of the intestinal epithelium, the carnitine-conjugated polymeric micelles targeting to the carnitine/organic cation transporter 2 (OCTN2) were developed by combining carnitine-conjugated poly(2-ethyl-2-oxazoline)-poly(d,l-lactide) with monomethoxy poly(ethylene-glycol)-poly(d,l-lactide). The carnitine-conjugated micelles with favorable stability in gastrointestinal fluid were validated to remarkably increase the cellular internalization and transcellular transport, while these were not the cases in the presence of free carnitine. These were further confirmed by more distribution of the micelles within epithelial cells, on the apical and basolateral side of the epithelium in mice. Additionally, identification of the carnitine-conjugated micelles by OCTN2 was detected to facilitate cellular uptake of the micelles via fluorescence immunoassay. Both clathrin and caveolae/lipid rafts pathways mediated endocytosis and transcellular transport of the carnitine-conjugated micelles, implying the enrichment of endocytic and transcellular transport pathway compared with that of carnitine-unconjugated micelles. Further, the intracellular trafficking process of the carnitine-conjugated micelles was tracked under confocal laser scanning microscopy, which involved in intracellular compartments such as late endosomes, lysosomes, endoplasmic reticulum, and Golgi apparatus as well. In conclusion, the current study provided an efficient strategy to facilitate the oral absorption of water-insoluble and poorly absorbed agents using intestinal transporter-mediated polymeric micelles.

Preparation of paclitaxel-folic acid functionalized gelatin grafted mesoporous hollow carbon nanospheres for enhancing antitumor effects toward liver cancer (SMMC-7721) cell lines

Folic acid functionalized gelatin-coated mesoporous hollow carbon nanospheres (FGMCN) were synthesized and applied to enhance the antitumor curative effect of paclitaxel (PTX) for human liver cancer cell lines (SMMC-7721). PTX was loaded in FGMCN by the adsorption method and the PTX-loaded samples (PTX-FGMCN) had a drug content of 29.8 ± 1.06%. The PTX-FGMCN with a sustained release effect was characterized by X-ray diffraction and differential scanning calorimeter in order to analyze the PTX state in FGMCN. In vitro cell experiments showed that FMHSN improves the uptake of PTX and promotes apoptosis due to the nano-targeting effect of FMHSN. An in vivo tumor bearing experiment in mice indicated that the PTX-FGMCN significantly inhibited the growth of tumors. All of these results suggested that the PTX-FGMCN may be an effective anti-hepatoma drug in the future.

Evaluation of intestinal permeation enhancement with carboxymethyl chitosan-rhein polymeric micelles for oral delivery of paclitaxel

Polymeric micelles (PMs) are currently under investigation as potential nanocarriers for oral administration of paclitaxel (PTX). Previously, we developed amphiphilic carboxymethyl chitosan-rhein (CR) conjugate for oral delivery of PTX. PTX-loaded CR PMs exhibited a homogeneous and small size (<200 nm) with a drug loading capacity (DL) of 35.46 ± 1.07%. However, The absorption parameters of PTX using CR PMs have not been studied before. Here, we evaluated the intestinal permeation of CR PMs by in situ intestinal absorption experiments. PTX-loaded CR PMs enhanced the absorption of PTX in the intestine without causing significant intestinal villi injury. Compared to the P-glycoprotein (P-gp) inhibition of verapamil, the transport mechanism of CR PMs across intestinal epithelial cells may bypass P-gp efflux. Caco-2 cell uptake assays also confirmed that CR PMs can be taken up into the enterocyte as whole and independent of P-gp. Local biodistribution evaluation showed that fluorescence-labeled CR PMs were absorbed into the intestinal villi. In vivo bioimaging of tumor-bearing mice verified a significant portion of CR PMs were intactly absorbed through the intestine, then distributed and accumulated at the tumor site. For their significant intestinal permeation enhancement, CR PMs might be considered as promising oral delivery carriers for PTX and other water-insoluble drugs.

One-Step Synthesis of Nitrogen-Doped Hydrophilic Mesoporous Carbons from Chitosan-Based Triconstituent System for Drug Release

In situ nitrogen-doped hydrophilic mesoporous carbon spheres with different carbon-to-silicon (C/Si) ratios (NMCs-x/3, x = 5, 6, 7, and 8) were prepared by one-step method coupled with a spray drying and carbonizing technique, in which triblock copolymer (F127) and tetraethyl orthosilicate (TEOS) were used as template agents, and biocompatible chitosan (CS) was used as the carbon source and nitrogen source. These carbon materials were characterized by TG, BET, XRD, Raman, FTIR, TEM, XPS, and contact angle measuring device. The adsorption and release properties of mesoporous carbon materials for the poorly soluble antitumor drug hydroxycamptothecin (HCPT) were investigated. Results showed that nanospherical mesoporous carbon materials were successfully prepared with high specific surface area (2061.6 m²/g), narrowly pore size distribution (2.01-3.65 nm), and high nitrogen content (4.75-6.04%). Those NMCs-x showed a satisfactory hydrophilicity, which gradually increased with the increasing of surface N content. And the better hydrophilicity of NMCs-x was, the larger adsorption capacity for HCPT. The absorption capacity of NMCs-x towards HCPT was in the following orders: q_NMCs-5/3 > q_NMCs-6/3 > q_NMCs-7/3 > q_NMCs-8/3. NMCs-5/3 had the largest saturated adsorption capacity of HCPT (1013.51 mg g^-1) and higher dissolution rate (93.75%).

A Comparative Study of the Use of Mesoporous Carbon and Mesoporous Silica as Drug Carriers for Oral Delivery of the Water-Insoluble Drug Carvedilol

Mesoporous carriers have been extensively applied to improve the dissolution velocity and bioavailability of insoluble drugs. The goal of this work was to compare the drug-loading efficiency (LE) and drug-dissolution properties of mesoporous silica nanoparticles (MSN) and mesoporous carbon nanoparticles (MCN) as drug vectors oral delivery of water-insoluble drugs. For this purpose, MSN and MCN with similar particle size, surface area, and mesoporous diameter were prepared to precisely evaluate the effects of different textures on the drug-loading and dissolution behavior of insoluble drugs. Carvedilol (CAR), a Bio-pharmaceutic Classification System (BCS) class II drug, was loaded in the MSN and MCN by the solvent adsorption method and solvent evaporation method with different carrier–drug ratios. The carboxylated MCN (MCN–COOH) had a higher LE for CAR than MSN for both the two loading methods due to the strong adsorption effect and π–π stacking force with CAR. In vitro drug dissolution study showed that both MSN and MCN-COOH could improve the dissolution rate of CAR compared with the micronized CAR. In comparison to MSN, MCN-COOH displayed a slightly slower dissolution profile, which may be ascribed to the strong interaction between MCN-COOH and CAR. Observation of cell cytotoxicity and gastrointestinal mucosa irritation demonstrated the good biocompatibility of both MSN and MCN–COOH. The present study encourages further research of different carriers to determine their potential application in oral administration.

Preparation and evaluation of carboxymethyl chitosan-rhein polymeric micelles with synergistic antitumor effect for oral delivery of paclitaxel

An amphiphilic carboxymethyl chitosan-rhein (CR) conjugate was prepared, characterized, and evaluated as a potential carrier material for oral delivery of paclitaxel (PTX). CR conjugate self-assembled in aqueous environment into CR polymeric micelles (CR PMs). The drug loading capacity and entrapment efficiency of PTX-loaded CR PMs were 35.24 ± 1.58% and 86.99 ± 12.26%, respectively. Pharmacokinetic results indicate that PTX-loaded CR PMs could significantly enhance the oral bioavailability of PTX. Confocal imaging of intestinal sections verified many of CR PMs were absorbed as whole through the intestinal membrane. The cytotoxicity assays in Caco-2 cells and in vivo antitumor efficacy showed that PTX-loaded CR PMs had a stronger antitumor efficacy. A synergistic antitumor effect between CR conjugate and PTX was proven in MCF-7 cells and antitumor efficacy studies. The investigation of CR conjugate developed in this study showed that CR PMs are promising for oral delivery of water-insoluble antitumor drugs.

Folate and Borneol Modified Bifunctional Nanoparticles for Enhanced Oral Absorption

Oral delivery is considered the preferred route of administration due to its convenience and favorable compliance. Here, docetaxel (DTX) loaded polylactic-co-glycolic acid (PLGA) nanoparticles, coated with polyethyleneimine⁻folic acid (PEI-FA) and polyethyleneimine⁻borneol (PEI-BO), were designed to enhance oral absorption (FA/BO-PLGA-NPs). The FA/BO-PLGA-NPs were spherical and smooth with an average size of (137.0 ± 2.1) nm. Encapsulation efficiency (EE%) and drug loading (DL%) were (80.3 ± 1.8)% and (2.3 ± 0.3)%, respectively. In vitro release studies showed that approximately 62.1% of DTX was released from FA/BO-PLGA-NPs in media at pH 7.4. The reverted gut sac method showed that the absorption of FA/BO-PLGA-NPs in the intestines was approximately 6.0 times that of DTX. Moreover, cellular uptake suggested that the obtained FA/BO-PLGA-NPs could be efficiently internalized into Caco-2 cells via FA-mediated active targeting and BO-mediated P-glycoprotein (P-gp) inhibition. Pharmacokinetics study demonstrated that after oral administration of DTX at a dose of 10 mg/kg in FA/BO-PLGA-NPs, the bioavailability of FA/BO-PLGA-NPs was enhanced by approximately 6.8-fold compared with that of DTX suspension. FA/BO-PLGA-NPs caused no obvious irritation to the intestines. Overall, the FA/BO-PLGA-NP formulation remarkably improved the oral bioavailability of DTX and exhibited a promising perspective in oral drug delivery.

Effect of Paclitaxel-Mesoporous Silica Nanoparticles with a Core-Shell Structure on the Human Lung Cancer Cell Line A549

A nanodrug delivery system of paclitaxel-mesoporous silica nanoparticles with a core-shell structure (PAC-csMSN) was used to increase the dissolution of paclitaxel (PAC) and improve its treatment of lung cancer. PAC was loaded into the core-shell mesoporous silica nanoparticles (csMSN) by the adsorption equilibrium method and was in an amorphous state in terms of its mesoporous structure. In vitro and in vivo studies showed that csMSN increased the dissolution rate of PAC and improved its lung absorption. The area under concentration-time curve (AUC) value of PAC-csMSN used for pulmonary delivery in rabbits was 2.678-fold higher than that obtained with the PAC. After continuous administration for 3 days, a lung biopsy showed no signs of inflammation. Cell apoptosis results obtained by flow cytometry indicated that PAC-csMSN was more potent than pure PAC in promoting cell apoptosis. An absorption investigation of PAC-csMSN in A549 cells was carried out by transmission electron microscopy (TEM) and laser scanning confocal microscopy (LSCM). The obtained results indicated that the cellular uptake was time-dependent and csMSN was uptaken into the cytoplasm. All these results demonstrate that csMSN have the potential to achieve pulmonary inhalation administration of poorly water-soluble drugs for the treatment of lung cancer.

Mesoporous carbon nanomaterials in drug delivery and biomedical application

Recent development of nano-technology provides highly efficient and versatile treatment methods to achieve better therapeutic efficacy and lower side effects of malignant cancer. The exploration of drug delivery systems (DDSs) based on nano-material shows great promise in translating nano-technology to clinical use to benefit patients. As an emerging inorganic nanomaterial, mesoporous carbon nanomaterials (MCNs) possess both the mesoporous structure and the carbonaceous composition, endowing them with superior nature compared with mesoporous silica nanomaterials and other carbon-based materials, such as carbon nanotube, graphene and fullerene. In this review, we highlighted the cutting-edge progress of carbon nanomaterials as drug delivery systems (DDSs), including immediate/sustained drug delivery systems and controlled/targeted drug delivery systems. In addition, several representative biomedical applications of mesoporous carbon such as (1) photo-chemo synergistic therapy; (2) delivery of therapeutic biomolecule and (3) in vivo bioimaging are discussed and integrated. Finally, potential challenges and outlook for future development of mesoporous carbon in biomedical fields have been discussed in detail.

Improved oral absorption and anti-lung cancer activity of paclitaxel-loaded mixed micelles

The aim of this study was to establish a paclitaxel (PTX)-loaded mixed micelle delivery system (PTX-TP-M) with vitamin E-TPGS (TPGS) and Plasdone®S-630 Copovidone (PVPS630) as carriers to improve the solubility, oral absorption, and anti-tumor activity of PTX against lung cancer. In this study, PTX-TP-M was prepared using the ethanol thin-film dispersion method followed by characterization of the binary mixed micelles system. The average size of the PTX-TP-M was 83.5 ± 1.8 nm with a polydispersity index of 0.265 ± 0.007 and the drug loading (DL%) and entrapment efficiency (EE%) were 3.09 ± 0.09% and 95.67 ± 2.84%, respectively, which contributed to a high solubility of PTX about 24947-fold increase in water (4.78 ± 0.14 mg/mL). In addition, TEM analysis showed that the PTX-TP-M appeared spherical in structure and was well dispersed without aggregation and adhesion. In vitro release studies showed that the PTX-TP-M displayed a sustained release compared to free PTX in the dialysis bag. The efflux ratio of PTX reduced from 44.83 to 3.52 when formulated as PTX-TP-M; a 92.15% reduction, studied using the Caco-2 monolayer model. The oral bioavailability of PTX also improved by 4.35-fold, suggesting that PTX-TP-M can markedly promote the absorption in the gastrointestinal tract. Using in vitro MTT assays, it was observed that cytotoxicity was markedly increased, and IC50 values of PTX-TP-M (3.14 ± 0.85 and 8.28 ± 1.02 μg/mL) were lower than those of PTX solution (5.21 ± 0.93 and 14.53 ± 1.96 μg/mL) in A549 and Lewis cell, respectively. In vivo anti-tumor studies showed that PTX-TP-M achieved higher anti-tumor efficacy compared with PTX in Lewis bared C57BL/6 mice. Furthermore, a gastrointestinal safety assay also proved the safety of PTX-TP-M. All results demonstrated that the PTX-TP-M exhibited great potential for delivering PTX with increased solubility, oral bioavailability, and anti-cancer activity and this binary mixed micelles drug delivery system has potential to be used clinically.

Size effect on oral absorption in polymer-functionalized mesoporous carbon nanoparticles

In this manuscript, the effect of the particle size of polymer-functionalized mesoporous carbon (MPP) nanoparticles on enhancing oral absorption of a water-insoluble drug is first investigated. The insoluble drug, fenofibrate (Fen), was selected as the model drug loaded in the MPP nanoparticles. MPP nanoparticles with different particle sizes were designed for improving the oral bioavailability of drugs, in which the branched polyethyleneimine (PEI) and polyacrylic acid (PAA) were modified on the surfaces of mesoporous carbon nanoparticles (MCNs) with amide bonds. In addition, PEI-functionalized carbon quantum dots (PCA) and radioisotope ¹²⁵I were applied to label the MPP nanoparticles to trace in the vivo process. According to the data, the MPP nanoparticles could markedly improve the dissolution rate and oral bioavailability of Fen. Interestingly, the MPP nanoparticle size had a notable effect on Fen oral absorption, and intermediate sized MPP nanoparticles were expected to be more ideal oral drug carriers. The nanoparticles were safe and easily excreted. These findings present the prospect of MPP nanoparticles for oral application, and guides the rational design of an oral delivery system with respect to particle size.

A comparison between sphere and rod nanoparticles regarding their in vivo biological behavior and pharmacokinetics

In recent years, spherical nanoparticles has been studied extensively on biomedical applications including bioimaging and biosensing, diagnostics and theranostics, but the effect of the shape of nanoparticles has received little attention. In the present study, we designed three different shaped fluorescent mesoporous silica nanoparticles (MSNs), long rod nanoparticles (NLR), short rod nanoparticles (NSR), and spherical nanoparticles (NS) to systematically examine their behavior in vivo after oral administration. The results of the ex vivo optical imaging study in mice indicated that rod nanoparticles had a longer residence time in the gastrointestinal compared with spherical nanoparticles. The in vivo biodistribution showed that all the orally administered MSNs were mainly taken up by the liver, and kidney. NLR had a great capacity to overcoming rapid clearance by the RES and exhibited a longer circulation in the blood than NSR and NS. During renal excretion, the spherical nanoparticles were cleared faster than rod nanoparticles. In addition, it was also found that MSNs can be degraded in vivo and NSR were degraded faster than NLR and NS probably owing to their higher specific surface area. The pharmacokinetic results demonstrated that nifedipine(NI)-loaded NLR had a higher bioavailability than NI-loaded NSR and NS.

Cellular level evaluation and lysozyme adsorption regulation of bimodal nanoporous silica

The present work initially evaluated cellular toxicity and uptake of our previous biomimetic bimodal nanoporous silica (B-BNS) and applied it as lysozyme adsorbent, which aimed to study potential ability of B-BNS as antitumor biological macromolecules carrier. To highlight the advantage of bimodal mesopores, comparisons were made between single mesoporous silica nanoparticles (S-MSN) and B-BNS. Cell evaluation work was conducted using MCF-7 cells and lysozyme adsorption process was studied with pH and lysozyme concentration as independent variables. The results indicated that the toxicity of S-MSN and B-BNS on MCF-7 cell could be neglected. In addition, S-MSN and B-BNS had the ability to be uptaken into cells and even nucleus evidenced by inverted fluorescence microscope and confocal laser scanning microscopic. Compared to S-MSN, B-BNS adsorbed larger amount of lysozyme due to its bimodal mesopores. Lysozyme adsorption was favorably approximated by the pseudo-second order model. The equilibrium data of lysozyme adsorption were fitted to the Langmuir isotherm model much better than the Freundlich isotherm model, suggesting that lysozyme adsorption on B-BNS via the monolayer adsorption process. Overall, B-BNS can be considered as good antitumor biological macromolecules carrier.

Evaluation of mesoporous carbon aerogels as carriers of the non-steroidal anti-inflammatory drug ibuprofen

Towards the development of novel drug carriers for oral delivery of poorly soluble drugs mesoporous aerogel carbons (CAs), namely CA10 and CA20 with different pore sizes (10 and 20nm, respectively), were evaluated. The non-steroidal anti-inflammatory lipophilic compound ibuprofen was incorporated via passive loading. The drug loaded carbon aerogels were systemically investigated by means of High-Resolution Transmission Electron Microscopy (HR-TEM), Nitrogen physisorption studies, X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), X-ray photon electron spectroscopy (XPS) and ζ-potential studies. In vitro release studies were performed in simulated intestinal fluids reflecting both fasted (FaSSIF) and fed (FeSSIF) state conditions. Cytotoxicity studies were conducted with human intestinal cells (Caco-2). Drug was in an amorphous state in the pores of the carbon carrier as shown from the physicochemical characterization studies. The results showed marked differences in the release profiles for ibuprofen from the two aerogels in the media tested whereas in vitro toxicity profiles appear to be compatible with potential therapeutic applications at low concentrations.

Colloidal and micro-carbon spheres derived from low-temperature polymerization reactions

Carbon spheres (CSs) have recently attracted major interest due to their new applications, mainly in energy storage and conversion but also in hard-templating, sorption/catalysis processes, and drug delivery systems. This is attributable to their physico-chemical properties, including their tunable morphology (solid, hollow and core-shell), size, surface area/porosity, good electrical conductivity, low external surface-to-volume ratio, high packing density, enhanced mass transport, robust mechanical stability, low cytotoxicity, and excellent biocompatibility. They can be obtained from a wide variety of carbon precursors and methods. This review covers their production by carbonization of polymer spheres from low-temperature polymerization reactions, considered here as below 250°C. This is a very important method because it allows the synthesis of CSs with different morphologies and doped with other elements or chemical compounds. The preparation of polymer spheres by this technique is well documented in the literature, and the objective of this review is to summarize and give an overview of the most significant publications, proposing a novel classification based on the formation mechanism of the polymer spheres. This classification includes the following polymerization processes: emulsion polymerization and its derivatives, seeded emulsion and inverse emulsion polymerization; precipitation polymerization and its derivative, dispersion polymerization; hard-templating; spray-drying; and hydrothermal or solvothermal treatment of carbohydrates and biomass in general. This review also reports on the morphology and surface characteristics of the CSs obtained by different synthetic approaches. The final section of the review describes the current applications of these CSs, notably in energy storage (supercapacitors and rechargeable batteries) and energy conversion (fuel cells and dye-sensitized solar cells). Besides the numerous applications listed above, they are utilized as sacrificial hard templates to prepare single- and multi-shell hollow spheres of metal oxides and other inorganic compounds and filters, as well as in adsorption and catalysis processes, drug delivery systems, and other minority applications (e.g., lubricants, black pigment in e-papers, and microwave absorber).

RGD-peptide conjugated inulin-ibuprofen nanoparticles for targeted delivery of Epirubicin

Recently, chemotherapy-based polymeric nanoparticles have been extensively investigated for solid tumor treatment. Tumor targeted nanoparticles demonstrated great potential for improved accumulation in the tumor tissue, superior anticancer activity and reduced side effects. Thus, inulin-ibuprofen polymer was synthesized by esterification between inulin and ibuprofen, and RGD targeted epirubicin (EPB) loaded nanoparticles were prepared by the self-assembly of inulin-ibuprofen polymer and in situ encapsulation of EPB. RGD conjugated EPB loaded nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscope (TEM). The EPB release from the nanoparticles showed pH-dependent profile and accelerated by the decreased pH value, which would favor the effective drug delivery in vivo. Intracellular uptake analysis suggested that RGD conjugated nanoparticles could be easily internalized by the cancer cells. In vitro cytotoxicity revealed that RGD conjugated EPB loaded nanoparticles exhibited the better antitumor efficacy compared with non-conjugated nanoparticles. More importantly, RGD conjugated EPB loaded nanoparticles showed superior anticancer effects and reduced toxicity than free EPB and non-conjugated nanoparticles by in vivo antitumor activity, EPB biodistribution and histology analysis.

A review of the ligands and related targeting strategies for active targeting of paclitaxel to tumours

It has been 30 years since the discovery of the anti-tumour property of paclitaxel (PTX), which has been successfully applied in clinic for the treatment of carcinomas of the lungs, breast and ovarian. However, PTX is poorly soluble in water and has no targeting and selectivity to tumour tissue. Recent advances in active tumour targeting of PTX delivery vehicles have addressed some of the issues related to lack of solubility in water and non-specific toxicities associated with PTX. These PTX delivery vehicles are designed for active targeting to specific cancer cells by the addition of ligands for recognition by specific receptors/antigens on cancer cells. This article will focus on various ligands and related targeting strategies serving as potential tools for active targeting of PTX to tumour tissues, illustrating their use in different tumour models. This review also highlights the need of further studies on the discovery of receptors in different cells of specific organ and ligands with binding efficiency to these specific receptors.

Novel Nanostructured Solid Materials for Modulating Oral Drug Delivery from Solid-State Lipid-Based Drug Delivery Systems

Lipid-based drug delivery systems (LBDDS) have gained significant attention in recent times, owing to their ability to overcome the challenges limiting the oral delivery of poorly water-soluble drugs. Despite the successful commercialization of several LBDDS products over the years, a large discrepancy exists between the number of poorly water-soluble drugs displaying suboptimal in vivo performances and the application of LBDDS to mitigate their various delivery challenges. Conventional LBDDS, including lipid solutions and suspensions, emulsions, and self-emulsifying formulations, suffer from various drawbacks limiting their widespread use and commercialization. Accordingly, solid-state LBDDS, fabricated by adsorbing LBDDS onto a chemically inert solid carrier material, have attracted substantial interest as a viable means of stabilizing LBDDS whilst eliminating some of the various limitations. This review describes the impact of solid carrier choice on LBDDS performance and highlights the importance of appropriate solid carrier material selection when designing hybrid solid-state LBDDS. Specifically, emphasis is placed on discussing the ability of the specific solid carrier to modulate drug release, control lipase action and lipid digestion, and enhance biopharmaceutical performance above the original liquid-state LBDDS. To encourage the interested reader to consider their solid carrier choice on a higher level, various novel materials with the potential for future use as solid carriers for LBDDS are described. This review is highly significant in guiding future research directions in the solid-state LBDDS field and fostering the translation of these delivery systems to the pharmaceutical marketplace.