The objective of the present work was to investigate the effects of the mixture of nonionic/ionic surfactants on nanostructured lipid carriers (NLCs). Nonionic surfactant (polyethylene–poly(propylene glycol), Pluronic F68) and ionic surfactant (octenylsuccinic acid modified gum arabic, GA-OSA) were chosen as emulsifier for NLCs. The NLCs systems, which were composed of lipid matrix, modified 4-dedimethylaminosancycline (CMT-8), and various emulsifier agents, were characterized with dynamic light scattering (DLS), high performance liquid chromatography (HPLC), transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), in vitro release, and phagocytosis assay. This mixture of nonionic/ionic surfactants showed significant effects on physical properties including particle size, polydispersity index (PDI), entrapment efficiency, and particle morphology. Compared with single stabilizer, this mixed nonionic/ionic surfactant system provided NLCs with better drug carrier properties including prolonged release profile and low phagocytosis by phagocyte. We expect that these explorations can provide a new strategy for the development of lipid nanoparticles as drug delivery.

•Progress in lipid-based nanostructured dispersions for drug delivery applications highlighted•Key role of the structure determinations via the SAXS method for the nanomedicine design emphasized•Features of nanocarrier structural design for delivery of macromolecular drugs and anticancer phytochemicals outlinedThe present work highlights recent achievements in development of nanostructured dispersions and biocolloids for drug delivery applications. We emphasize the key role of biological small-angle X-ray scattering (BioSAXS) investigations for the nanomedicine design. A focus is given on controlled encapsulation of small molecular weight phytochemical drugs in lipid-based nanocarriers as well as on encapsulation of macromolecular siRNA, plasmid DNA, peptide and protein pharmaceuticals in nanostructured nanoparticles that may provide efficient intracellular delivery and triggered drug release. Selected examples of utilisation of the BioSAXS method for characterization of various types of liquid crystalline nanoorganizations (liposome, spongosome, cubosome, hexosome, and nanostructured lipid carriers) are discussed in view of the successful encapsulation and protection of phytochemicals and therapeutic biomolecules in the hydrophobic or the hydrophilic compartments of the nanocarriers. We conclude that the structural design of the nanoparticulate carriers is of crucial importance for the therapeutic outcome and the triggered drug release from biocolloids.Protein-loaded liquid crystalline lipid nanoparticle (left) and calculated small-angle X-ray scattering (SAXS) curves of biocolloidal dispersions (right).Download high-res image (250KB)Download full-size image

•It is the first time to synthesis BF/β-CD inclusion complex and FA targeted inclusion complex.•The BF/β-CD inclusion complex with IE of (94.22 ± 0.85) % and DL of (14.11 ± 0.20) % were much higher than other bufalin. carriers.•FA targeted inclusion complex significantly enhanced the solubility, cell uptake and antitumor efficiency of bufalin.Bufalin (BF), a traditional Chinese medicine, exhibited inhibitory activities against a broad spectrum of tumor cells. The present study elaborates that bufalin was successfully encapsulated into the cavity of β-cyclodextrin (β-CD), which was determined by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The best reaction mole ratio of BF/β-CD was 1:5. The solubilities of bufalin in water and phosphate buffer solution (pH = 7.4) were increased up to 24 and 34 times after encapsulated into the cavity of β-CD respectively. The inclusion efficiency (IE) and drug loading (DL) of bufalin in the inclusion complex were (94.22 ± 0.85)% and (14.11 ± 0.20)%, respectively. Then β-CD conjugated with folic acid (FA) were further prepared and employed to improve the anti-tumor efficacy of inclusion complex. The in vitro dissolution and solubility study showed better values of inclusion complex and FA targeted inclusion complex than that of pure BF. Cytotoxicity experiments by using HCT116 cell line revealed that the antitumor efficiency of bufalin were enhanced more than two folds in the presence of β-CD and folate conjugated β-CD (FA-PEI-β-CD), which demonstrated the potential application of β-CD (FA-PEI-β-CD) as delivery vehicles of bufalin for antitumor therapy.Download high-res image (176KB)Download full-size image

The interaction between biosurfactant Surfactin and cationic Gemini surfactant ethanediyl-1,3-bis(dodecyldimethylammonium bromide) (abbreviated as 12-3-12) was investigated using turbidity, surface tension, dynamic light scattering (DLS) and small angle neutron scattering (SANS). Analysis of critical micelle concentration (CMC) values in Surfactin/12-3-12 mixture indicates that there is synergism in formation of mixed Surfactin/12-3-12 micelles. Although Surfactin and 12-3-12 are oppositely charged in phosphate buffer solution (PBS, pH7.4), there are no precipitates observed at the concentrations below the CMC of Surfactin/12-3-12 system. However, at the concentration above CMC value, the Surfactin/12-3-12 mixture is severely turbid with high 12-3-12 content. DLS and SANS measurements follow the size and shape changes of mixed Surfactin/12-3-12 aggregates from small spherical micelles via elongated aggregates to large bulk complexes with increasing fraction of Gemini surfactant.

•The stable Doxorubicin hydrochloride loaded NLC was designed and prepared.•The DOX-OA/NLCs had a tumor specific drug release.•DLS, TEM, DSC and SAXS were used to study the physicochemical properties.•The EE and DL of DOX in NLC was 97.80% and 4.09%, respectively.•The DOX-OA/NLCs had comparable cytotoxicity to pure DOX and were favorably taken up by HCT 116 cells.The hydrophilic drug Doxorubicin hydrochloride (DOX) paired with oleic acid (OA) was successfully incorporated into nanostructured lipid carriers (NLCs) by a high-pressure homogenization (HPH) method. Drug nanovehicles with proper physico-chemical characteristics (less than 200 nm with narrow size distribution, spherical shape, layered internal organization, and negative electrical charge) were prepared and characterized by dynamic light scattering, zeta potential measurements, transmission electron microscopy, small-angle X-ray scattering and differential scanning calorimetry. The drug loading and entrapment efficiency of DOX-OA/NLCs were 4.09% and 97.80%, respectively. A pH-dependent DOX release from DOX-OA/NLCs, i.e., fast at pH 3.8 and 5.7 and sustained at pH 7.4, was obtained. A cytotoxicity assay showed that DOX-OA/NLCs had comparable cytotoxicity to pure DOX and were favorably taken up by HCT 116 cells. The intracellular distribution of DOX was also studied using a confocal laser scanning microscope. All of these results demonstrated that DOX-OA/NLCs could be a promising drug delivery system with tumor-specific DOX release for cancer treatment.

•Stable BJO-loaded nanostructure lipid carriers (NLCs) was prepared by HPH.•The BJO-loaded NLCs featured very high encapsulation efficiency and drug loading.•NLCs could enhance the antitumor effect of BJO obviously.•NLCs was used as the carrier of BJO for the first time.This study was aimed at preparing a stable nanostructure lipid carriers for Brucea javanica oil (BJO/NLCs) using the high-pressure homogenization (HPH) method. The obtained BJO/NLCs exhibited a particle size of approximately 180 nm and were quite stable during 30 days of storage. The entrapment efficiency (EE) and drug loading (DL) of BJO/NLCs were good, with values of up to 99.2% and 10.4%, respectively. The polydispersity index (PDI) and zeta potential values of BJO/NLCs were 0.17 and −31.2 mV, respectively. BJO/NLCs exhibited spherical or elongated particles when viewed by transmission electron microscopy (TEM). Small-angle X-ray scattering (SAXS) further confirmed that the internal structures of blank NLCs and BJO/NLCs were arranged into lamellar phases. Anti-tumor activity was studied using the MTT assay; the BJO/NLCs showed improved cytotoxicity to A549 cells. Taken together, these results indicate that this newly designed BJO/NLCs delivery system has the potential to exhibit improved BJO bioavailability.

Multidrug delivery devices are designed to take advantage of the synergistic effects of anticancer agents in combination therapies. Here we report novel liquid crystalline self-assembled nanocarriers enhancing the activity of the phytochemical anticancer agent baicalin (BAI) in combination with Brucea javanica oil (BJO), which ensures safe formulations for clinical applications. Small-angle X-ray scattering (SAXS) and cryogenic transmission electron microscopy (cryo-TEM) evidenced the multicompartment, sponge-type nano-organization of the blank and multidrug-loaded liquid crystalline carriers. Physico-chemical stability of the sponge nanoparticles was achieved through PEGylation of the lipid membranes, which make up the drug nanocarriers. The proposed green nanotechnology for nanocarrier preparation by supramolecular self-assembly provided a multidrug encapsulation efficiency as high as 75%. The apoptosis study with the human lung carcinoma cell line A549 demonstrated improved efficacy of the multidrug delivery nanocarriers in comparison to the single-drug reservoirs. The obtained results evidenced the synergistic anticancer apoptotic effects of the multidrug-loaded nanosponge carriers and suggested the opportunity for in vivo translation towards the treatment of lung, gastrointestinal, and ovarian cancers.

•The stable nanostructured lipid carrier was designed and prepared by HPH.•DLS, TEM, SANS, SAXS and XRD were used to study the physicochemical properties.•Docetaxel was used as an API to study the effects of lipophilic drug on NLC.•SANS was firstly used to study the microstructure of NLC for release properties.The aim of this study was to prepare a stable nanostructured lipid carrier (NLC) with biocompatible lipids and surfactants (Pluronic F68 and Cremophor EL) by high-pressure homogenization (HPH). Surface tension measurements were used to choose the suitable ratio between Pluronic F68 and Cremophor EL. Hydrophobic anticancer drug docetaxel (DTX) was used as an active pharmaceutical ingredient (API). The mean particle size of docetaxel loaded nanostructured lipid carrier (DTX-NLC), as determined by dynamic light scattering (DLS), was between 120 nm and 250 nm during the storage period of 30 days, with the entrapment efficiency decreasing from (60.5 ± 5.0)% to (55.3 ± 4.5)%, while zeta potential was slightly changed from (−43.19 ± 3.6) mV to (−40.12 ± 4.3) mV. Transmission electron microscopy (TEM) showed that some of DTX-NLCs have elongated shape. Small angle neutron scattering (SANS) demonstrated that DTX-NLC in solution contained dense core with perfectly smooth surface, while blank NLC had dense core but rough surface. The blank NLC and DTX-NLC showed cubic crystalline structure according to small angle X-ray scattering (SAXS). Wide angle X-ray diffraction (XRD) showed that adding of DTX increased the crystallinity of the NLC. Cytotoxicity was studied by MTT assay against Hela cells. The data suggested that blank NLC was biocompatible with HeLa cells while the DTX-NLC was more cytotoxic than pure DTX at the same drug concentration. DTX-NLC could be taken up into the cells more than pure DTX, which could be attributed to the better solubility of DTX after loading into NLC.

The interactions among neutral polymer polyacrylamide (PAM) and the biosurfactant Surfactin and four betaines, N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SDDAB), N-tetradecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (STDAB), N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SHDAB), and N-dodecyl-N,N-dimethyl-2-ammonio-acetate (C12BE), in phosphate buffer solution (PBS) have been studied by surface tension measurements, small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and rheological experiments. It has been confirmed that the length of alkyl chain is a key parameter of interaction between betaines and PAM. Differences in scattering contrast between X-ray and neutrons for surfactants and PAM molecules provide the opportunity to separately follow the changes of structure of PAM and surfactant aggregates. At concentrations of betaines higher than CMC (critical micelle concentration) and C2 (CMC of surfactant with the presence of polymer), spherical micelles are formed in betaines and betaines/PAM solutions. Transition from spherical to rod-like aggregates (micelles) has been observed in solutions of Surfactin and Surfactin/SDDAB (αSurfactin = 0.67 (molar fraction)) with addition of 0.8 wt % of PAM. The conformation change of PAM molecules only can be observed for Surfactin/SDDAB/PAM system. Viscosity values follow the structural changes suggested from scattering measurements i.e., gradually increases for mixtures PAM → Surfactin/PAM → Surfactin/SDDAB/PAM in PBS.

The objective of the present work was to investigate the effects of the mixture of nonionic/ionic surfactants on nanostructured lipid carriers (NLCs). Nonionic surfactant (polyethylene–poly(propylene glycol), Pluronic F68) and ionic surfactant (octenylsuccinic acid modified gum arabic, GA-OSA) were chosen as emulsifier for NLCs. The NLCs systems, which were composed of lipid matrix, modified 4-dedimethylaminosancycline (CMT-8), and various emulsifier agents, were characterized with dynamic light scattering (DLS), high performance liquid chromatography (HPLC), transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), in vitro release, and phagocytosis assay. This mixture of nonionic/ionic surfactants showed significant effects on physical properties including particle size, polydispersity index (PDI), entrapment efficiency, and particle morphology. Compared with single stabilizer, this mixed nonionic/ionic surfactant system provided NLCs with better drug carrier properties including prolonged release profile and low phagocytosis by phagocyte. We expect that these explorations can provide a new strategy for the development of lipid nanoparticles as drug delivery.

The interactions between the lipopeptide Surfactin and four betaines, N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SDDAB), N-tetradecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (STDAB), N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SHDAB), and N-dodecyl-N,N-dimethyl-2-ammonio-acetate (C12BE) are studied by surface tension and small-angle neutron scattering (SANS). SDDAB, STDAB, and SHDAB have the same headgroup but different hydrophobic chains. C12BE has different headgroup but the same hydrophobic chain with SDDAB. According to the interfacial parameters calculated from surface tension, the synergism between Surfactin and betaine is relevant with the molecule structure of betaine and the mole ratio of them. For betaines, the optimum alkyl chain length (STDAB) and long enough separation between positive charge and negative charge in headgroup are responsible for highest synergetic interaction with Surfactin. The aggregates of individual Surfactin and the mixtures of Surfactin and sulfopropyl betaines are predicted to be spherical based on the packing parameter (pp) and the average packing parameter (Pav), which is in close qualitative agreement with SANS data analysis, while Surfactin/C12BE forms ellipsoidal micelles due to the smaller headgroup of C12BE.

•Sponge-type nanocarriers (spongosomes) for Brucea javanica oil (BJO) are prepared.•SAXS, Cryo-TEM and DLS are used to study the physicochemical features.•Spongosome nanocarriers show high encapsulation efficiency and drug loading.•BJO-loaded spongosomes enhance the antitumor effect compared to free BJO.Sponge-type nanocarriers (spongosomes) are produced upon dispersion of a liquid crystalline sponge phase formed by self-assembly of an amphiphilic lipid in excess aqueous phase. The inner organization of the spongosomes is built-up by randomly ordered bicontinuous lipid membranes and their surfaces are stabilized by alginate chains providing stealth properties and colloidal stability. The present study elaborates spongosomes for improved encapsulation of Brucea javanica oil (BJO), a traditional Chinese medicine that may strongly inhibit proliferation and metastasis of various cancers. The inner structural organization and the morphology characteristics of BJO-loaded nanocarriers at varying quantities of BJO were determined by cryogenic transmission electron microscopy (Cryo-TEM), small angle X-ray scattering (SAXS) and dynamic light scattering (DLS). Additionally, the drug loading and drug release profiles for BJO-loaded spongosome systems also were determined. We found that the sponge-type liquid crystalline lipid membrane organization provides encapsulation efficiency rate of BJO as high as 90%. In vitro cytotoxicity and apoptosis study of BJO spongosome nanoparticles with A549 cells demonstrated enhanced anti-tumor efficiency. These results suggest potential clinical applications of the obtained safe spongosome formulations.

Multidrug delivery devices are designed to take advantage of the synergistic effects of anticancer agents in combination therapies. Here we report novel liquid crystalline self-assembled nanocarriers enhancing the activity of the phytochemical anticancer agent baicalin (BAI) in combination with Brucea javanica oil (BJO), which ensures safe formulations for clinical applications. Small-angle X-ray scattering (SAXS) and cryogenic transmission electron microscopy (cryo-TEM) evidenced the multicompartment, sponge-type nano-organization of the blank and multidrug-loaded liquid crystalline carriers. Physico-chemical stability of the sponge nanoparticles was achieved through PEGylation of the lipid membranes, which make up the drug nanocarriers. The proposed green nanotechnology for nanocarrier preparation by supramolecular self-assembly provided a multidrug encapsulation efficiency as high as 75%. The apoptosis study with the human lung carcinoma cell line A549 demonstrated improved efficacy of the multidrug delivery nanocarriers in comparison to the single-drug reservoirs. The obtained results evidenced the synergistic anticancer apoptotic effects of the multidrug-loaded nanosponge carriers and suggested the opportunity for in vivo translation towards the treatment of lung, gastrointestinal, and ovarian cancers.