Enhanced brain targeting of curcumin by intranasal administration of a thermosensitive poloxamer hydrogel

OBJECTIVES

The aim of this study was to develop a curcumin intranasal thermosensitive hydrogel and to improve its brain targeting efficiency.

METHODS

The hydrogel gelation temperature, gelation time, drug release and mucociliary toxicity characteristics as well as the nose-to-brain transport in the rat model were evaluated.

KEY FINDINGS

The developed nasal hydrogel, composed of Pluronic F127 and Poloxamer 188, had shorter gelation time, longer mucociliary transport time and produced prolonged curcumin retention in the rat nasal cavity at body temperature. The hydrogel release mechanism was diffusion-controlled drug release, evaluated by the dialysis membrane method, but dissolution-controlled release when evaluated by the membraneless method. A mucociliary toxicity study revealed that the hydrogel maintained nasal mucosal integrity until 14 days after application. The drug-targeting efficiencies for the drug in the cerebrum, cerebellum, hippocampus and olfactory bulb after intranasal administration of the curcumin hydrogel were 1.82, 2.05, 2.07 and 1.51 times that after intravenous administration of the curcumin solution injection, respectively, indicating that the hydrogel significantly increased the distribution of curcumin into the rat brain tissue, especially into the cerebellum and hippocampus.

CONCLUSIONS

A thermosensitive curcumin nasal gel was developed with favourable gelation, release properties, biological safety and enhanced brain-uptake efficiency.

Identification of circulating microRNAs as potential biomarkers for detecting acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. The disease is characterized by various cytogenetic and molecular abnormalities with distinct prognoses and gene expression profiles. Emerging evidence has suggested that circulating microRNAs (miRNAs) could serve as noninvasive biomarkers for cancer detection; however, little is known about circulating miRNA profiles in AML patients. In this study, a genome-wide serum miRNA expression analysis was performed using Solexa sequencing for initial screen, followed by validation with real-time PCR assays. The analysis was conducted on training and verification sets of serum samples from 140 newly diagnosed AML patients and 135 normal adult donors. After a two-phase selection and validation process, 6 miRNAs, miR-10a-5p, miR-93-5p, miR-129-5p, miR-155-5p, miR-181b-5p and miR-320d, were found to have significantly different expression levels in AML compared with control serum samples. Furthermore, unsupervised clustering analysis revealed the remarkable ability of the 6-miRNA profile to differentiate between AML patients and normal controls. The areas under the ROC curve for the selected miRNAs ranged from 0.8129 to 0.9531. More importantly, miR-181b-5p levels in serum were significantly associated with overall survival. These data demonstrated that the expression patterns of circulating miRNAs were systematically altered in AML and miR-181b-5p may serve as a predictor for overall survival in AML patients.

Abstract 329: δ-Opioid Receptor Mediated Regulation of Cortical MicroRNAs in the Rat Under Hypoxia

Cardiovascular disorders may reduce blood/oxygen supply to the brain, causing serious neurological disabilities. Activation of the delta-opioid receptor (DOR) induces cortical protection against hypoxic/ischemic insults. However, the mechanism underlying DOR protection is largely unclear yet. We have recently found that DOR activation modulates microRNA expression in the kidney exposed to hypoxic stress, suggesting that DOR protection may involve a microRNA mechanism. To determine if the microRNAs expressed in the cortex mediate DOR neuroprotection, we examined nineteen microRNAs, that are previously identified as hypoxia- and DOR-regulated microRNAs in the kidney, in the cortex treated with DOR activation in hypoxic condition. Total RNA for qPCR was isolated from the cortex of control or hypoxic rats as well as those animals treated with UFP-512, a potent and specific DOR agonist. Of the 19 microRNAs tested, 17 were significantly altered by hypoxia and/or DOR activation with the direction and amplitude dependent on hypoxic duration and times of DOR treatment. Several microRNAs such as miR-29b, 101b, -298, 324-3p, -347 and 466b were significantly depressed by hypoxia for 24 hours. The similar changes were seen in normoxic condition 24 hours after DOR activation with one time treatment of UFP-512. In contrast, some miRNAs were more tolerant to hypoxic stress and did not show any significant reduction until 5-days (e.g., miR-31 and -186) or 10-days (e.g., miR-29a, let-7f and -511), while DOR activation had differential effects on these miRNAs. Moreover, some miRNAs like miRs-363* and -370 were affected only by the combination of hypoxia and DOR treatment, with reductions greater than 70% in 5-day group. These data suggest that cortical microRNAs are significantly altered in response to hypoxia with differential hypoxia sensitivity among them and that DOR activation is able to modify, enhance or resolve the changes in microRNAs that are predicted to target ion transport, HIF, axonal guidance, free radical signaling, apoptosis and many other functions.

A microRNA expression signature predicts meningioma recurrence

The aberrant expression of microRNAs (miRNAs) is associated with a variety of diseases, including cancer. In our study, we examined the miRNA expression profile of meningiomas, which is a common type of benign intracranial tumor derived from the protective meninges membranes that surround the brain and spinal cord. To define a typical human meningioma miRNA profile, the expression of 200 miRNAs in a training sample set were screened using quantitative reverse transcription polymerase chain reaction analysis, and then significantly altered miRNAs were validated in a secondary independent sample set. Kaplan-Meier and univariate/multivariate Cox proportional hazard regression analyses were performed to assess whether miRNA expression could predict the recurrence of meningioma after tumor resection. After a two-phase selection and validation process, 14 miRNAs were found to exhibit significantly different expression profiles in meningioma samples compared to normal adjacent tissue (NAT) samples. Unsupervised clustering analysis indicated that the 14-miRNA profile differed between tumor and NAT samples. Downregulation of miR-29c-3p and miR-219-5p were found to be associated with advanced clinical stages of meningioma. Kaplan-Meier analysis showed that high expression of miR-190a and low expression of miR-29c-3p and miR-219-5p correlated significantly with higher recurrence rates in meningioma patients. Cox proportional hazard regression analysis revealed that miR-190a expression level is an important prognostic predictor that is independent of other clinicopathological factors. Our results suggest that the use of miRNA profiling has significant potential as an effective diagnostic and prognostic marker in defining the expression signature of meningiomas and in predicting postsurgical outcomes.

Identification of seven serum microRNAs from a genome-wide serum microRNA expression profile as potential noninvasive biomarkers for malignant astrocytomas

The involvement of circulating microRNAs (miRNAs) in cancer and their potential as biomarkers of diagnosis and prognosis are becoming increasingly appreciated; however, little is known about circulating miRNA profiles in astrocytomas. In our study, we performed genome-wide serum miRNA analysis by the Solexa sequencing followed by validation conducted in the training and verification sets with a stem-loop quantitative reverse-transcription PCR (RT-qPCR) assay from serum samples of 122 untreated astrocytomas patients (WHO grades III-IV) and 123 normal controls. Identified miRNAs were subsequently examined in 55 grade II, 15 grade I astrocytomas, 11 astrogliosis, 42 other primary brain tumors and 8 tumor tissues from grades II-IV astrocytomas. In addition, paired serum samples before and after operation were collected from 14 malignant astrocytomas to determine the effect of surgery on the miRNAs' levels. A marked difference in serum miRNA profile was observed between high-grade astrocytomas and normal controls. Seven miRNAs were validated by RT-qPCR assay to be significantly decreased in grades II-IV patients (p < 0.001), including miR-15b*, miR-23a, miR-133a, miR-150*, miR-197, miR-497 and miR-548b-5p, and the seven-miRNA panel demonstrated a high sensitivity (88.00%) and specificity (97.87%) for malignant astrocytomas prediction. These identified miRNAs also exhibited a global decrease in tumor tissues relative to normal tissues. Furthermore, these miRNAs in serum were markedly elevated after operation (p < 0.001). In addition, some of these serum miRNAs were significantly different between malignant and benign cases, astrogliosis and other primary brain tumors. The seven serum miRNAs identified in our study hold potential as noninvasive biomarker for malignant astrocytomas.

Preliminary experience of endoscopic submucosal tunnel dissection for upper gastrointestinal submucosal tumors

BACKGROUND AND STUDY AIM

Although the majority of submucosal tumors (SMTs) are benign, some do have a malignant potential. Resection of SMTs would aid in establishing the diagnosis and may be curative. Our aim was to examine the feasibility and safety of a novel method for endoscopic resection of upper gastrointestinal SMTs.

PATIENTS AND METHODS

In 12 patients who presented with an upper gastrointestinal SMT of ≤40 mm located in the esophagus or cardia, a submucosal tunnel was endoscopically created starting approximately 5 cm proximal to the lesion. After careful submucosal dissection with carbon dioxide or air insufflation, the SMTs were completely removed, and the entrance of the tunnel closed using endoclips.

RESULTS

SMTs had a mean size of 19.5 mm (range 10-40 mm); eight were located in the esophagus and four in the cardia. SMT resection was successful in all patients with en bloc resection in 10 patients (83.3%) and resection in two pieces in the remaining two patients. The mean time required for the procedure was 48.3 minutes (range 30-60 minutes). Two patients had both pneumothorax and subcutaneous emphysema. All the complications resolved with conservative management.

CONCLUSIONS

In this pilot study, endoscopic submucosal tunnel dissection (ESTD) of esophageal and cardia SMTs was effective and appeared to be safe. Larger studies that also examine its application for gastric SMTs are warranted.

Activated β-catenin forces N2A cell-derived neurons back to tumor-like neuroblasts and positively correlates with a risk for human neuroblastoma

Neuroblastoma is an embryonic malignancy arising from neuroblasts. The mechanisms that regulate the origination of neuroblastoma are still not very clear. In this study, we revealed that 6-bromoindirubin 3'-oxime (BIO), a specific GSK-3β inhibitor, promoted N2A cells-derived neurons to become tumor-like neuroblasts. Moreover, constitutively activated β-catenin (S33Y) also promoted this process, whereas, silencing endogenous expression of β-catenin abolished BIO-induced effects. These results implicated the potential relationship between the Wnt/β-catenin signaling and neuroblastoma formation. Indeed, we found that the amount of β-catenin in nucleus, which indicated the activation of Wnt/β-catnin signaling, was accumulated in human neuroblastoma specimens and positively correlated with clinical risk of neuroblastoma. These results give us a new sight into the neuroblastoma initiation and progression, and provide a potential drug target for neuroblastoma treatment.

4-Chloro-N'-(2-hy-droxy-4-meth-oxy-benzyl-idene)benzohydrazide methanol monosolvate

The title compound, C₁₅H₁₃ClN₂O₃·CH₃OH, was synthesized by the condensation reaction of 2-hy­droxy-4-meth­oxy­benzaldehyde with 4-chloro­benzohydrazide in methanol. The Schiff base mol­ecule displays a trans configuration with respect to the C=N and C—N bonds. The dihedral angle between the two benzene rings is 5.3 (2)°. In the crystal, mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen-bond inter­actions into chains running parallel to the a axis. An intra­molecular O—H⋯N hydrogen bond is observed.

Fabrication of a nanocarrier system through self-assembly of plasma protein and its tumor targeting

Human serum albumin (HSA) nanoparticles hold great promise as a nanocarrier system for targeted drug delivery. The objective of this study was to explore the possibility of preparing size controllable albumin nanoparticles using the disulfide bond breaking reagent β-mercaptoethanol (β-ME). The results showed that the protein concentration and temperature had positive effects on the sizes of the albumin nanoparticles, while pH had a negative effect on the rate of nanoparticle formation. The addition of β-ME induced changes in HSA secondary structure and exposed the hydrophobic core of HSA, leading to the formation of nanoparticles. Human serum albumin nanoparticles could be internalized by MCF-7 cells and mainly accumulated in cytoplasm. After injection in tumor bearing mice, the HSA nanoparticles accumulated in tumor tissues, demonstrating the targeting ability of the nanoparticles. Therefore, human serum albumin can be fabricated into nanoparticles by breaking the disulfide bonds and these nanoparticles exhibit high tumor targeting ability. Human serum albumin nanoparticles could be ideal for the targeted delivery of pharmacologically active substances.

2-[6,8-Dibromo-3-(4-hydroxycyclohexyl)-1,2,3,4-tetrahydroquinazolin-2-yl]phenol methanol 0.25-solvate

The title compound, C₂₀H₂₂Br₂N₂O₂·0.25CH₄O, was synthesized by the condensation reaction of salicyl­aldehyde with 4-(2-amino-3,5-dibromo­benzyl­amino)­cyclo­hexa­nol in methanol. There are four independent main mol­ecules and two half-occupied methanol solvent mol­ecules in the asymmetric unit. The dihedral angles between the two benzene rings in the four mol­ecules are 87.8 (6), 86.6 (6), 89.3 (6) and 83.1 (6)°. Each mol­ecule features an intra­molecular O—H⋯N hydrogen bond and a short N—H⋯Br link. In the crystal components are linked by O—H⋯O hydrogen bonds.

N'-(2-Hydr-oxy-4-methoxy-benzyl-idene)isonicotinohydrazide

The title compound, C(14)H(13)N(3)O(3), was synthesized by the condensation reaction of 2-hydr-oxy-4-methoxy-benzaldehyde with isonicotinohydrazide in a methanol solution. The mol-ecule of the compound displays a trans configuration with respect to the C=N and C-N bonds. The dihedral angle between the benzene and the pyridine rings is 27.3 (2)°. In the crystal, mol-ecules are linked by N-H⋯N inter-actions into zigzag chains with graph-set notation C(7) along [010]. An intra-molecular O-H⋯N hydrogen bond is observed.

The use of hsa-miR-21, hsa-miR-181b and hsa-miR-106a as prognostic indicators of astrocytoma

BACKGROUND

The aberrant expression of microRNAs (miRNAs) is associated with a variety of diseases including cancers. In the present study, the miRNA expression profile was examined in astrocytoma, a malignant and prevalent intracranial tumour in adults.

METHODS

We screened the expression profile of 200 miRNAs in a training sample set consisting of 84 astrocytoma samples and 20 normal adjacent tissue (NAT) samples using the method of stem-loop quantitative RT-PCR. The significantly altered miRNAs were validated in another independent sample set consisting of 40 astrocytoma samples and 40 NAT samples. The correlation of the miRNA levels with survival in astrocytoma samples was estimated by performing Kaplan-Meier survival analysis and univariate/multivariate Cox proportional hazard regression analysis.

RESULTS

After a two-phase selection and validation process, seven miRNAs were found to have a significantly different expression profile in astrocytoma samples upon comparison to the NAT samples. Unsupervised clustering analysis further revealed the great potential of the 7-miRNA profile to differentiate between tumours and normal brain tissues. The down-regulation of hsa-miR-137 in astrocytomas was shown to be associated with advanced clinical stages of this disease. Using Kaplan-Meier survival analysis we showed that low expression of hsa-miR-181b or hsa-miR-106a, or high expression of hsa-miR-21 was significantly associated with poor patient survival. Moreover, Cox proportional hazard regression analysis revealed that this prognostic impact was independent of other clinicopathological factors.

CONCLUSIONS

Our results suggest a great potential for the use of miRNA profiling as a powerful diagnostic and prognostic marker in defining the signature of astrocytomas and in predicting the post-surgical outcome.

N'-(2-Chloro-5-nitro-benzyl-idene)isonicotinohydrazide

The title compound, C(13)H(9)ClN(4)O(3), was synthesized by the condensation reaction of 2-chloro-5-nitro-benzaldehyde with isonicotinohydrazide in a methanol solution. The mol-ecule of the compound displays a trans configuration with respect to the C=N and C-N bonds. The dihedral angle between the benzene and pyridine rings is 12.1 (2)°. In the crystal structure, adjacent mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming dimers.

2-[6,8-Dibromo-3-(4-hydroxy-cyclo-hexyl)-1,2,3,4-tetra-hydro-quinazolin-2-yl]-6-methoxy-phenol

The title compound, C(21)H(24)Br(2)N(2)O(3), was synthesized by the condensation reaction of 3-methoxy-salicylaldehyde with 4-(2-amino-3,5-dibromo-benzyl-amino)cyclo-hexa-nol in a methanol solution. The dihedral angle between the two benzene rings is 76.4 (3)°. The cyclo-hexyl ring adopts a chair configuration. There is an intra-molecular O-H⋯N hydrogen bond which affects the solid state conformation of the mol-ecule. The crystal structure is stabilized by inter-molecular O-H⋯O hydrogen bonds, forming chains running along the b axis.

5-Methyl-2-phenyl-2H-pyrazol-3-ol

The title compound, C₁₀H₁₀N₂O, known as Edaravone (MCI-186), was crystallized from methanol. The two independent mol­ecules in the asymmetric unit are linked through an O—H⋯O hydrogen bond. One mol­ecule adopts a ketone form, while the other adopts an enol form. In the crystal structure, mol­ecules are linked through inter­molecular N—H⋯O hydrogen bonds, forming chains running along the b axis.

6-Chloro-N'-(2-hydr-oxy-1-naphthyl-methyl-ene)nicotinohydrazide

The title compound, C₁₇H₁₂ClN₃O₂, was synthesized by the Schiff base condensation reaction of 2-hydr­oxy-1-naphthaldehyde with 6-chloro­nicotinic acid hydrazide in a methanol solution. The mol­ecule displays a trans configuration with respect to the C=N and C—N bonds. The dihedral angle between the naphthyl ring system and the pyridine ring is 7.6 (4)°. There is an intra­molecular O—H⋯N hydrogen bond. The crystal structure is stabilized by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds, forming chains running along the b axis.

Investigation of excipient and processing on solid phase transformation and dissolution of ciprofloxacin

Ciprofloxacin, a very slightly soluble antibiotics, is known to exist as both anhydrous and hydrous forms. This study was carried out to investigate the solid phase transformation of ciprofloxacin during conventional formulation processing that impacts the performance of solid dosage forms. In addition, alternative processing and formulation options were also evaluated to circumvent phase transformation. Anhydrate and hydrate of ciprofloxacin were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) and powder dissolution. As expected, the anhydrate exhibited significantly higher dissolution rate than the hydrate. However, it rapidly converted to the hydrate upon exposure to aqueous medium. Interestingly, premixing the anhydrate with HPMC in the presence of water or ethanol was found to inhibit the processing-induced phase transition. Further studies demonstrated that wet granulation could be an option for preparing tablets with high loading of ciprofloxacin anhydrate through proper selection of excipients and control of processing conditions. Dissolution study of ciprofloxacin in HPMC based extended release matrix tablets indicated different dissolution rates between tablets containing the anhydrate and hydrate, suggesting transformation to the hydrate was significantly inhibited by HPMC in the gel layer of the hydrated tablets.

Floating matrix dosage form for phenoporlamine hydrochloride based on gas forming agent: In vitro and in vivo evaluation in healthy volunteers

Phenoporlamine hydrochloride is a novel compound that is used for the treatment of hypertension. The purpose of this study was to develop a sustained release tablet for phenoporlamine hydrochloride because of its short biological half-life. Three floating matrix formulations of phenoporlamine hydrochloride based on gas forming agent were prepared. Hydroxypropyl methylcellulose K4M and Carbopol 971P NF were used in formulating the hydrogel drug delivery system. Incorporation sodium bicarbonate into matrix resulted in the tablet floating over simulated gastric fluid for more than 6h. The dissolution profiles of all tablets showed non-Fickian diffusion in simulated gastric fluid. Moreover, release of the drug from these tablets was pH-dependent. In vivo evaluations of these formulations of phenoporlamine hydrochloride were conducted in six healthy male human volunteers to compare the sustained release tablets with immediate release tablets. Data obtained in these studies demonstrated that the floating matrix tablet containing more Carbopol was capable of sustained delivery of the drug for longer periods with increased bioavailability and the relative bioavailability of formulation (containing 25% Carbopol 971P NF, 8.3% HPMC K4M) showed the best bioequivalency to the reference tablet (the relative bioavailability was 1.11+/-0.19).

Dihydroayapin, a new coumarin compound from Dendrobium densiflorum

A new coumarin named dihydroayapin (1) together with seven known compounds were isolated from the stems of Dendrobium densiflorum. On the basis of physicochemical and spectral evidences, the structure of 1 was established as 6,7-methylenedioxy-3,4-dihydrobenzopyran-2-one.