Progress of reprogramming astrocytes into neuron.

As the main players in the central nervous system (CNS), neurons dominate most life activities. However, after accidental trauma or neurodegenerative diseases, neurons are unable to regenerate themselves. The loss of this important role can seriously affect the quality of life of patients, ranging from movement disorders to disability and even death. There is no suitable treatment to prevent or reverse this process. Therefore, the regeneration of neurons after loss has been a major clinical problem and the key to treatment. Replacing the lost neurons by transdifferentiation of other cells is the only viable approach. Although much progress has been made in stem cell therapy, ethical issues, immune rejection, and limited cell sources still hinder its clinical application. In recent years, somatic cell reprogramming technology has brought a new dawn. Among them, astrocytes, as endogenously abundant cells homologous to neurons, have good potential and application value for reprogramming into neurons, having been reprogrammed into neurons in vitro and in vivo in a variety of ways.

LBO-EMSC Hydrogel Serves a Dual Function in Spinal Cord Injury Restoration via the PI3K-Akt-mTOR Pathway.

It is critical to obtain an anti-inflammatory microenvironment when curing spinal cord injury (SCI). On the basis of this, we prepared Lycium barbarum oligosaccharide (LBO)-nasal mucosa-derived mesenchymal stem cells (EMSCs) fibronectin hydrogel for SCI restoration via inflammatory license effect and M2 polarization of microglias. LBO exhibited remarkable M2 polarization potential for microglia. However, EMSCs primed by LBO generated enhanced paracrine effects through the inflammatory license-like process. The observed dual function is likely based on the TNFR2 pathway. In addition, LBO-EMSC hydrogel possesses a synergistic effect on M2 polarization of microglia through the PI3K-Akt-mTOR signaling pathway. The obtained findings provide a simple approach for MSC-based therapies for SCI and shed more light on the role of TNFR2 on bidirectional regulation in tissue regeneration.

Enhanced oral bioavailability of Bisdemethoxycurcumin-loaded self-microemulsifying drug delivery system: Formulation design, in vitro and in vivo evaluation.

In this study, we sought to overcome the poor solubility and bioavailability of bismethoxycurcumin (BDMC) by fabricating a BDMC-loaded self micro-emulsifying system (BDMC-SMEDDS). Solubility and compatibility tests, pseudo-ternary phase diagrams (PTPDs) as well as d-optimal concept was applied to design the formulation. The assessment of the prepared BDMC-SMEDDS in-vitro mainly included droplet size (DS) and entrapment efficiency (EE) determination, morphology, drug release and stability testing. Besides, the in vivo behavior was also evaluated after oral administration of BDMC-SMEDDS to rats. The optimal formulation was found to compose of Kolliphor EL (K-EL, emulsifier, 645.3 mg), PEG 400 (co-emulsifier, 147.2 mg), ethyl oleate (EO, oil, 207.5 mg) and BDMC (50 mg). The BDMC-SMEDDS with satisfactory stability had a mean size of 21.25 ± 3.23 nm and EE of 98.31 ± 0.32%. Roughly 70% of BDMC was released from BDMC-SMEDDS within 84 h compared with <20% from the free BDMC. More importantly, the in-vivo behavior of BDMC-SMEDDS showed that the AUC(0-12h) and plasma concentration of BDMC increased substantially as compared to the free BDMC. Altogether, BDMC-SMEDDS has the potential to enhance the solubility and bioavailability of BDMC and could be applied in the clinics.

Novel cuminaldehyde self-emulsified nanoemulsion for enhanced antihepatotoxicity in carbon tetrachloride-treated mice.

OBJECTIVES: Cuminaldehyde self-emulsified nanoemulsion (CuA-SEN) was prepared and optimised to improve its oral bioavailability and antihepatotoxicity. METHODS: Cuminaldehyde self-emulsified nanoemulsion was developed through the self-nanoemulsification method using Box-Behnken Design (BBD) tool while appropriate physicochemical indices were evaluated. The optimised CuA-SEN was characterised via droplet size (DS), morphology, polydispersity index (PDI), zeta potential (ZP), entrapment efficiency, in-vitro release, and pharmacokinetic studies while its antihepatotoxicity was evaluated. KEY FINDINGS: Cuminaldehyde self-emulsified nanoemulsion with acceptable characteristics (mean DS-48.83 ± 1.06 nm; PDI-0.232 ± 0.140; ZP-29.92 ± 1.66 mV; EE-91.51 ± 0.44%; and drug-loading capacity (DL)-9.77 ± 0.75%) was formulated. In-vitro drug release of CuA-SEN significantly increased with an oral relative bioavailability of 171.02%. Oral administration of CuA-SEN to CCl4 -induced hepatotoxicity mice markedly increased the levels of superoxide dismutase, glutathione and catalase in serum. Also, CuA-SEN reduced the levels of tumour necrosis factor-alpha and interleukin-6 in both serum and liver tissues while aspartate aminotransferase, alanine aminotransferase and malonaldehyde levels were significantly decreased. CONCLUSIONS: These findings showed that the improved bioavailability of cuminaldehyde via SEN provided an effective approach for enhancing antioxidation, anti-inflammation and antihepatotoxicity of the drug.

Preparation, optimization, and pharmacokinetic study of nanoliposomes loaded with triacylglycerol-bound punicic acid for increased antihepatotoxic activity.

Punicic acid of pomegranate oil (PAP) has gained heightened interest due to several health benefits, such as anticarcinogenic, antidiabetic, and antiatherosclerotic properties. However, these bioactivities have been hampered by chemical instability, poor water solubility, rapid metabolism, and low bioavailability of PAP. Therefore, this study was aimed at optimizing the liposomal formulation of Triacylglycerol-bound punicic acid with its regioisomers (TPAR) for improved oral bioavailability and increased hepatoprotection through antioxidation and anti-inflammation. Herein, the optimized TPAR nanoliposome (TPAR-NL) was developed using thin-film dispersion method and subsequently characterized with appropriate indices. The optimized TPAR-NL produced fairly stable spherical nanoparticles (˂ 200 nm) with encapsulation efficiency (%EE) of 85.77%, as well as enhanced in vitro release and improved oral bioavailability. The TPAR-NL exhibited profound antihepatotoxic effect in mice pretreated with carbon tetrachloride (CCl4 ) via reduction of serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels compared with free TPAR. The TPAR-loaded liposome also significantly reduced oxidative stress by increasing superoxide dismutase and glutathione levels while lowering malonaldehyde concentration compared with the free TPAR. The TPAR-LNF further exhibited remarkable anti-inflammatory activity compared with the free drug via inhibition of interleukin-6 and tumor necrosis factor-alpha generation. Thus, the developed nanoliposomes potentiated the antihepatotoxic activity of TPAR via antioxidation and anti-inflammation.

Redox-responsive PEGylated self-assembled prodrug-nanoparticles formed by single disulfide bond bridge periplocymarin-vitamin E conjugate for liver cancer chemotherapy.

Periplocymarin (PPM), a cardiac glycoside, has a narrow therapeutic index, poor tumor selectivity and severe cardiovascular toxicity which hinder its wide clinical applications in cancer treatment. Herein, we report novel redox-responsive prodrug-nanoparticles (MPSSV-NPs) self-assembled by co-nanoprecipitation of PPM-vitamin E conjugate and a PEG derivative of linoleate (mPEG2000-LA) in water. It was found that the characteristics of PPM-vitamin E nanoparticles (PSSV-NPs) were improved through co-nanoprecipitation with increased percentages of mPEG2000-LA. Moreover, the MPSSV-NPs were optimized according to the in vitro release and cytotoxicity study. Furthermore, the optimized MPSSV-NPs dramatically enhanced the circulation time and tumor distribution of PSSV-NPs after single intravenous injection. The in vivo studies in malignant H22-bearing mice revealed that MPSSV-NPs could effectively suppress tumor growth without causing obvious systemic toxicity. Altogether, these results suggested that MPSSV-NPs could offer a safe, multifunctional and viable nanoplatform for cardiac glycosides in cancer treatment.

Octreotide-periplocymarin conjugate prodrug for improving targetability and anti-tumor efficiency: synthesis, in vitro and in vivo evaluation.

Cardiac glycosides could increase intracellular Ca2+ ion by inhibiting the Na+/K+ATPase to induce apoptosis in many tumor cells. However, narrow therapeutic index, poor tumor selectivity and severe cardiovascular toxicity hinder their applications in cancer treatment. To improve the safety profile and tumor targetablility of cardiac glycosides, we designed octreotide conjugated periplocymarin, a cardiac glycoside isolated from Cortex periplocae. The conjugate showed higher cytotoxicity on MCF-7 cells and HepG2 tumor cells (SSTRs overexpression) but much less toxicity in L-02 normal cells. Tissue distribution studies of the conjugate using H22 tumor model in mice showed higher accumulation in tumor and lower distribution in heart and liver than periplocymarin. Furthermore, in vivo anticancer effects of the conjugate on mice bearing H22 cancer xenografts confirmed enhanced anti-tumor efficacy and decreased systemic toxicity. Altogether, octreotide-conjugated periplocymarin demonstrated tumor selectivity and may be useful as a targeting agent to improve the safety profile of cardiac glycosides for cancer therapy.

Tissue distribution and enhanced in vivo anti-hyperlipidemic-antioxidant effects of perillaldehyde-loaded liposomal nanoformulation against Poloxamer 407-induced hyperlipidemia.

An optimized perillaldehyde-loaded liposomal nanoformulation (PAH-LNF) was successfully applied to improve the pharmacological effect of perillaldehyde (PAH) in poloxamer 407-induced hyperlipidemia. Oral administration of PAH-LNF (240mg/kg per body weight) in rats significantly enhanced solubility and relative bioavailability (270.7%) compared to the free PAH with about 2.7-, 1.5-, 1.3-, 1.3- and 1.5-fold increase in AUC, T1/2, MRT, Cmax and Tmax, respectively. Tissue distribution study also revealed the accumulation of PAH in the liver, lungs, spleen, kidney, brain and heart in order of decreasing affinity. Moreover, a significant decrease in serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) with simultaneous increase in high-density lipoprotein cholesterol (HDL-C) level was observed in the chemically-induced hyperlipidemic mice which further confirmed PAH's anti-hyperlipidemic properties. Additionally, PAH-LNF also significantly increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) with a concurrent decrease in malondialdehyde (MDA) to affirm the antioxidant and hepatoprotective effects of PAH. Thus, liposomal nanoformulation promises to be a useful drug delivery system for the development of PAH.

Reduced Burst Release and Enhanced Oral Bioavailability in Shikimic Acid-Loaded Polylactic Acid Submicron Particles by Coaxial Electrospray.

In this study, using the coaxial electrospray method, we prepared submicron particles of the water-soluble drug shikimic acid (SA) with polylactic acid (PLA) as a polymer, to reduce the burst release and enhance the oral bioavailability. In vitro release study performed in HCl solution (pH 1.2) showed that the coaxial electrospray submicron particles could reduce burst release effect and presented a sustained release profile, compared with free SA and the particles prepared by electrospray method. The absorption of SA in the intestinal tract, studied using an in situ perfusion method in rats, also revealed jejunum as the main absorptive segment followed by duodenum and ileum. Moreover, the SA-loaded particles greatly enhanced the absorption of SA in the tested intestinal segments. The intestinal absorption rate was not enhanced with increasing drug concentration (5-15 µg/mL) which suggested that active transport or facilitated diffusion could play vital role in SA absorption. In addition, the SA-loaded PLA coaxial electrospray particle exhibited a prolonged plasma circulation with enhanced bioavailability after oral administration. In all, the coaxial electrospray technique could provide notable advantages for the oral delivery of SA, thereby enhancing its clinical application.

Hypolipidemic potential of perillaldehyde-loaded self-nanoemulsifying delivery system in high-fat diet induced hyperlipidemic mice: Formulation, in vitro and in vivo evaluation.

This study reports the hypolipidemic effects of perillaldehyde-loaded self-nanoemulsifying delivery system (PAH-SNEDS) developed with D-optimal experimental design based on a three component system: 40% w/w drug-oil phase, X1 (a mixture of perillaldehyde-isopropyl myristate/medium chain triglyceride, 1:1, w/w); 48% surfactant, X2 (Kolliphor EL); and 12% co-surfactant, X3 (PEG 200). The design space was navigated using a linear model to produce spherical and homogenous droplets which were observed under TEM, with mean size, polydispersity index (PDI) and zeta potential of 32.8 ± 0.1 nm, 0.270 ± 0.029 and -10.14 ± 0.66 mV, respectively. PAH-SNEDS demonstrated significant increase in dissolution in vitro compared to the free PAH, and further yielded an oral relative bioavailability of about 206.18% in vivo which suggested a promising formulation design for potential liquid bioactive compounds. Oral administration of PAH-SNEDS (240 mg/kg per body weight) in high-fat induced hyperlipidemia in mice, also significantly decreased serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) while increasing high-density lipoprotein cholesterol (HDL-C) level. The improved bioavailability and functional application of PAH via SNEDDS suggested a suitable approach to promote hypolipidemic effect of the drug. Perillaldehyde, therefore, promises to be a useful bioactive compound to prevent high-fat diet induced hyperlipidemia.

Tumor targeted delivery of octreotide-periplogenin conjugate: Synthesis, in vitro and in vivo evaluation.

Periplogenin (PPG), a cardiac glycoside prepared from Cortex periplocae, with similar structure to bufalin, has been found to induce apoptosis in many tumor cells. However, lots of cardiac glycosides possessing strong antitumor activity in vitro have still not passed phase I clinical trials, mostly due to poor tumor selectivity and systemic toxicity. To overcome this drawback, we designed octreotide-periplogenin (OCT-PPG) conjugate by coupling PPG-succinate to the amino-terminal end of octreotide. In comparison with free PPG, the conjugate exhibited significantly stronger cytotoxicity on HepG2 cells (SSTRs overexpression) but much less toxicity in L-02 cells. After intravenous injection of OCT-PPG conjugate into H22 tumor-bearing mice, its total accumulation in tumor was 2.3 fold higher than that of free PPG, but was 0.71- and 0.84-fold lower in heart and liver, respectively, suggesting somatostatin-mediated target delivery of PPG into the tumor tissue and reduced distribution in heart and liver. In vivo studies using H22 tumor model in mice confirmed the remarkable therapeutic effect of this conjugate. These results suggested that OCT-PPG conjugate could provide a new approach for clinical application of cardiac glycosides and as a targeting agent for cancer therapy.

Enhanced oral bioavailability and in vivo antioxidant activity of chlorogenic acid via liposomal formulation.

In the present study, a formulation system consisting of cholesterol and phosphatidyl choline was used to prepare an effective chlorogenic acid-loaded liposome (CAL) with an improved oral bioavailability and an increased antioxidant activity. The developed liposomal formulation produced regular, spherical and multilamellar-shaped distribution nanoparticles. The pharmacokinetic analysis of CAL compared with chlorogenic acid (CA), showed a higher value of Cmax(6.42 ± 1.49 min versus 3.97 ± 0.39 min) and a delayed Tmax(15 min versus 10 min), with 1.29-fold increase in relative oral bioavailability. The tissue distribution in mice also demonstrated that CAL predominantly accumulated in the liver which indicated hepatic targeting potential of the drug. The increased activities of antioxidant enzymes (Total Superoxide Dismutase (T-SOD) and Glutathione Peroxidase (GSH-Px)) and total antioxidant capacity (T-AOC), in addition to decreased level of malondialdehyde (MDA) in CCl4-induced hepatotoxicity study further revealed that CAL exhibited significant hepatoprotective and antioxidant effects. Collectively, these findings present a liposomal formulation with significantly improved oral bioavailability and an increased in vivo antioxidant activity of CA.

An efficient in vitro and in vivo HPLC method for hydnocarpin in nanomicelles formulation.

For quantitative and other related bioactive studies of hydnocarpin, there is a need to establish an efficient, specific and sensitive analytical method (in vitro and in vivo). In this paper, an efficient HPLC method has been established and validated to analyze hydnocarpin in a nanomicelle formulation for the first time. Various chromatographic conditions for in vitro and in vivo determinations were investigated, with the application examined by pharmacokinetics and tissue distribution studies. The analysis was carried out using an HPLC system with a Waters symmetry C18 column (4.6 × 150 mm, 5 µm) at 25°C with a detecting wavelength of 342 nm. Eluting at a rate of 1.0 mL/min, a 65% methanol and 35% acetic acid solution (0.1%) served as the mobile phase for the in vitro determinations while a 62% methanol and 38% acetic acid solution (0.1%) was used for in vivo analysis with isoliquiritigenin as internal standard. The established in vitro linearity range for hydnocarpin was 0.2-20 µg/mL (R(2) = 0.9996), with the biological (in vivo) samples following the same trend. The accuracy of the method was >99% (in vitro) and 92.4-105.3% (in vivo). Also, the precision met the acceptance criterion. These results indicate that the established method exhibited high specificity, accuracy, linearity and precision. Additionally, this efficient HPLC method was applied to pharmacokinetics and tissue distribution studies.

Realgar nanoparticle-based microcapsules: preparation and in-vitro/in-vivo characterizations.

OBJECTIVES: The aim of this study was to prepare microcapsules for the oral delivery of realgar nanoparticles (RN) that are also capable of improving its stability. METHODS: RN and RN-based microcapsules (RNM) were prepared using ball milling and solvent evaporation techniques, respectively. Properties such as particle size, ζ-potential (ZP), morphology and X-ray diffractometer (XRD) were investigated. In addition, drug release, bioavailability and antitumour studies were also performed. KEY FINDINGS: The nanoparticles appeared round or elliptical in shape with a mean size of 85.4 ± 3.5 nm and a ZP of -34.3 ± 1.7 mV. The obtained RNM appeared spherical and not aggregated with a relatively narrow size distribution. XRD analysis revealed that ball milling technique did not change the crystallinity of the realgar powder. RN and RNM exhibited considerable higher release of As2 S2 , bioavailability and antitumour efficacies compared with crude realgar. Furthermore, RNM could protect RN directly exposed to the air and light, and therefore increased the stability of the RN. CONCLUSIONS: The developed RNM demonstrated a greater potential as a delivery system for realgar.