Structural analysis and prebiotic activity of exopolysaccharide produced by probiotic strain Bifidobacterium bifidum EPS DA-LAIM.

Exopolysaccharide (EPS)-producing Bifidobacterium bifidum EPS DA-LAIM was isolated from healthy human feces, the structure of purified EPS from the strain was analyzed, and its prebiotic activity was evaluated. The EPS from B. bifidum EPS DA-LAIM is a glucomannan-type heteropolysaccharide with a molecular weight of 407-1007 kDa, and its structure comprises 2-mannosyl, 6-mannosyl, and 2,6-mannosyl residues. The purified EPS promoted the growth of representative lactic acid bacteria and bifidobacterial strains. Bifidobacterium bifidum EPS DA-LAIM increased nitric oxide production in RAW 264.7 macrophage cells, indicating its immunostimulatory activity. Bifidobacterium bifidum EPS DA-LAIM also exhibited high gastrointestinal tract tolerance, gut adhesion ability, and antioxidant activity. These results suggest that EPS from B. bifidum EPS DA-LAIM is a potentially useful prebiotic material, and B. bifidum EPS DA-LAIM could be applied as a probiotic candidate. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01213-w.

Potential Probiotic Properties of Exopolysaccharide-Producing Lacticaseibacillus paracasei EPS DA-BACS and Prebiotic Activity of Its Exopolysaccharide.

Exopolysaccharide (EPS)-producing Lacticaseibacillus paracasei EPS DA-BACS was isolated from healthy human feces and its probiotic properties, as well as the structure and prebiotic activity of the EPS from this strain were examined. EPS from L. paracasei EPS DA-BACS had a ropy phenotype, which is known to have potential health benefits and is identified as loosely cell-bounded glucomannan-type EPS with a molecular size of 3.7 × 106 Da. EPS promoted the acid tolerance of L. paracasei EPS DA-BACS and provided cells with tolerance to gastrointestinal stress. The purified EPS showed growth inhibitory activity against Clostridium difficile. L. paracasei EPS DA-BACS cells completely inhibited the growth of Bacillus subtilis, Pseudomonas aeruginosa, and Aspergillus brasiliensis, as well as showed high growth inhibitory activity against Staphylococcus aureus and Escherichia coli. Treatment of lipopolysaccharide-stimulated RAW 264.7 cells with heat-killed L. paracasei EPS DA-BACS cells led to a decrease in the production of nitric oxide, indicating the anti-inflammatory activity of L. paracasei EPS DA-BACS. Purified EPS promoted the growth of Lactobacillus gasseri, Bifidobacterium bifidum, B. animalis, and B. faecale which showed high prebiotic activity. L. paracasei EPS DA-BACS harbors no antibiotic resistance genes or virulence factors. Therefore, L. paracasei EPS DA-BACS exhibits anti-inflammatory and antimicrobial activities with high gut adhesion ability and gastrointestinal tolerance and can be used as a potential probiotic.

Peutz-Jeghers Syndrome Manifested as Multiple Polyps in Jejunum With Intussusception.

Peutz-Jeghers syndrome (PJS) is a relatively rare autosomal dominant genetic disease, often manifested as mucous membranes, skin pigmented spots and multiple polyps in the gastrointestinal tract. It can be followed by a variety of serious complications such as bleeding, obstruction, intussusception, and malignant transformation. We introduce the case of a 26-year-old male patient who was diagnosed with multiple polyps in the jejunum with intussusception caused by PJS. He was discharged after emergency surgery reduction and partial resection of the small intestine. Gastrointestinal polyps, hemorrhage, intussusception, intestinal obstruction, and increased risk of cancer occur in patients with PJS. Currently, polypectomy under endoscopic techniques, reexamination and follow-up are the main treatment options; surgical treatment is used for bleeding, intussusception, and cancer. Therefore, it is very necessary for us to have a correct understanding of it, actively prevent it, treat it and follow these patients closely.

Triple herbal extract DA-9805 exerts a neuroprotective effect via amelioration of mitochondrial damage in experimental models of Parkinson's disease.

Moutan cortex, Angelica Dahurica root, and Bupleurum root are traditional herbal medicines used in Asian countries to treat various diseases caused by oxidative stress or inflammation. Parkinson's disease (PD) has been associated with mitochondrial dysfunction, but no effective treatment for mitochondrial dysfunction has yet been identified. In this study we investigated the neuroprotective effects of the triple herbal extract DA-9805 in experimental models of PD. DA-9805 was prepared by extracting three dried plant materials (Moutan cortex, Angelica Dahurica root, and Bupleurum root in a 1:1:1 mixture) with 90% ethanol on a stirring plate for 24 h at room temperature and fingerprinted using high-performance liquid chromatography. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its active metabolite 1-methyl-4-phenylpyridinium (MPP+), which both exert neurotoxic effects on dopaminergic neurons by inhibiting mitochondrial oxidative phosphorylation (OXPHOS) complex I, were used to make experimental models of PD. In MPP+-treated SH-SY5Y cells, DA-9805 ameliorated the suppression of tyrosine hydroxylase expression and mitochondrial damage on OXPHOS complex 1 activity, mitochondrial membrane potential, reactive oxygen species (ROS) generation, and oxygen consumption rate. In the MPTP-induced subacute PD model mice, oral administration of DA-9805 recovered dopamine content as well as bradykinesia, as determined by the rotarod test. DA-9805 protected against neuronal damage in the substantia nigra pars compacta (SNpc) and striatum. In both in vitro and in vivo models of PD, DA-9805 normalized the phosphorylation of AKT at S473 and T308 on the insulin signaling pathway and the expression of mitochondria-related genes. These results demonstrate that the triple herbal extract DA-9805 showed neuroprotective effects via alleviating mitochondria damage in experimental models of PD. We propose that DA-9805 may be a suitable candidate for disease-modifying therapeutics for PD.

Evaluation of PEGylated exendin-4 released from poly (lactic-co-glycolic acid) microspheres for antidiabetic therapy.

Peptide-based therapies have the potential to induce antibody formation if the molecules differ from a native human peptide. Several reports have disclosed the occurrence of antibody generation in a patient treated with exenatide. The immune response can be problematic from a clinical stand point, particularly if the antibodies neutralize the efficacy of the biotherapeutic agent or cause a general immune reaction. To overcome this limit, PEGylated exendin-4 analogs were designed and examined for metabolic stability and biological activity. To develop an extended release delivery system for exendin-4 for the safe and effective delivery of bioactive exendin-4 without peptide acylation and immunogenicity, PEGylated exendin-4 was encapsulated into poly (lactic-co-glycolic acid) (PLGA) microspheres by w/o/w double emulsion solvent evaporation method. Peptide-loaded microspheres were characterized in terms of morphology, particle diameter, and peptide encapsulation efficiency. Then, the release profile of the peptide from PLGA microspheres and the acylated products from PLGA polymer degradation was determined. The results obtained showed that the stability of exendin-4 was greatly improved by PEGylation. Moreover, eliminated acylation during PLGA polymer degradation in vitro and reduced immunogenicity in vivo were observed. The findings demonstrate that PEGylated exendin-4-loaded microspheres may be a safe and biocompatible system for clinical development.

Expression and function of a modified AP2/ERF transcription factor from Brassica napus enhances cold tolerance in transgenic Arabidopsis.

One of the most rapid and effective defensive mechanisms plants have for protecting themselves, from a variety of biotic and abiotic stresses, is the regulation of plant signal transcription factors. AP2/ERF factors play an important role in plant development as well as in hormonal regulation and cold response. Directed evolution is a powerful tool to modify proteins, improving their properties, and for studying their structure-function relations. Here, the transgenic Arabidopsis plants over-expressed a mutant gene, BnaERF-B3-hy15-mu3, which encoded for a factor that exhibited more binding activity with the GCC box element than the wild-type gene BnaERF-B3-hy15 encode factor, and exhibited more freezing tolerance than transgenic plants containing the original BnaERF-B3-hy15 gene. Real-time PCR analyses also revealed that the expression levels of several stress-regulated genes were altered in the over-expressed BnaERF-B3-hy15-mu3 transgenic lines. The BnaERF-B3-hy15 responded to exogenous ABA. Using RT-PCR analysis, the expression of BnaERF-B3-hy15 at different stages and stress treatments were also analyzed.

[Clinical observation of placement of tympanostomy microtube to treat middle ear atelectasis].

OBJECTIVE: To investigate the treatment efficacy of tympanostomy microtube placement surgery for middle ear atelectasis. METHODS: A retrospective analysis was conducted on 26 patients (28 ears) with middle ear atelectasis, who complained fullness or pressure in the ears.Otoscope showed tympanic membrane invagination, scattered or disappeared cone of light, tympanic membrane was pale and dull. The pure tone audiometry air-bone gap >10 dB. Acoustic immittance showed tympanic negative pressure. All the ears had atelectasis of I-III grade. Patients were performed tympanic membrane microtube placement under local anesthesia, and were followed up for 6-12 months. RESULTS: Twenty-five ears recovered from the fullness after operation, in which, 23 ears reverted from type "C" to type "A" in acoustic immittance tests and the pure-tone average (PTA) of hearing thresholds were decreasing from 5 to 20 dB, while 2 ears relapse after removal of the microtube. Three ears with middle ear atelectasis of III grade were ineffectiveness. All the 26 cases had no complications including middle ear infection, tympanosclerosis, and permanent perforation after removal of the microtubes. CONCLUSIONS: The placement of tympanostomy microtube can be used to treat middle ear atelectasis, especially to the patients with middle ear atelectasis of I-II grade as it is effective on elimination of middle ear negative pressure and remission of fullness.

Site-specific PEGylated Exendin-4 modified with a high molecular weight trimeric PEG reduces steric hindrance and increases type 2 antidiabetic therapeutic effects.

The purpose of this study was to optimize an Exendin-4 (Ex4-Cys) site-specific PEGylation method with a high-molecular-weight trimeric PEG. Here, we describe the preparation of C-terminal specific PEGylated Ex4-Cys (C40-tPEG-Ex4-Cys), which was performed using cysteine and amine residue specific coupling reactions between Ex4-Cys and activated trimeric PEG. The C40-PEG-Ex4-Cys was obtained at high yields (~83%) and characterized by MALDI-TOF mass spectrometry. The receptor binding affinity of C40-PEG(5K)-Ex4-Cys was 3.5-fold higher than that of N-terminal PEGylated Ex4-Cys (N(ter)-PEG(5K)-Ex4-Cys), and receptor binding by the trimeric PEG (tPEG; 23, 50 kDa) adduct was much higher than that of branched PEG (20 kDa). Furthermore, C40-tPEG(50K)-Ex4-Cys was found to have greater blood circulating t(1/2) and AUC(inf) values than native Ex4-Cys by 7.53- and 45.61-fold, respectively. Accordingly, its hypoglycemic duration was much greater at 59.2 h than that of native Ex4-Cys at 7.3 h, with a dose of 25 nM/kg. The results of this study show that C-terminal specific PEGylation using trimeric PEG is effective when applied to Ex4-Cys and suggest that C40-tPEG(50K)-Ex4-Cys has considerable potential as a type 2 antidiabetic agent.

PEG-transferrin conjugated TRAIL (TNF-related apoptosis-inducing ligand) for therapeutic tumor targeting.

Transferrin (Tf) is considered an effective tumor-targeting agent, and PEGylation effectively prolongs in vivo pharmacokinetics by delaying excretion via the renal route. The authors describe the active tumor targeting of long-acting Tf-PEG-TNF-related apoptosis-inducing ligand conjugate (Tf-PEG-TRAIL) for effective cancer therapy. Tf-PEG-TRAIL was prepared using a two-step N-terminal specific PEGylation procedure using different PEGs (Mw: 3.4, 5, 10 kDa). Eventually, only 10 kDa PEG was linked to Tf and TRAIL because TRAIL (66 kDa) and Tf (81 kDa) were too large to link to 3.4 and 5 kDa PEG. The final conjugate Tf-PEG(10K)-TRAIL was successfully purified and characterized by SDS-PAGE, western blotting. To determine the specific binding of Tf-PEG(10K)-TRAIL to Tf receptor, competitive receptor binding assays were performed on K 562 cells. The results obtained demonstrate that the affinity of Tf-PEG(10K)-TRAIL for Tf receptor is similar to that of native Tf. In contrast, PEG(10K)-TRAIL demonstrated no specificity. Biodistribution patterns and antitumor effects were investigated in C57BL6 mice bearing B16F10 murine melanomas and BALB/c athymic mice bearing HCT116. Tumor accumulation of Tf-PEG(10K)-TRAIL was 5.2 fold higher (at 2 h) than TRAIL, because Tf-PEG(10K)-TRAIL has both passive and active tumor targeting ability. Furthermore, the suppression of tumors by Tf-PEG(10K)-TRAIL was 3.6 and 1.5 fold those of TRAIL and PEG(10K)-TRAIL, respectively. These results suggest that Tf-PEG(10K)-TRAIL is a superior pharmacokinetic conjugate that potently targets tumors and that it should be viewed as a potential cancer therapy.

Low molecular weight (1 kDa) polyethylene glycol conjugation markedly enhances the hypoglycemic effects of intranasally administered exendin-4 in type 2 diabetic db/db mice.

An intranasally active glucagon-like peptide-1 (GLP-1) formulation would have great advantages over conventional injectable therapies for the treatment of diabetic patients. The purpose of this study was to investigate the biological potentials of PEGylated exendin-4 (PEG-Ex4) analogs administered intranasally and the effects of polyethylene glycol (PEG) molecular weight (1, 2, 5 kDa) on nasal absorption. Initially, PEGEx4 analogs were site-specifically PEGylated to Lys²7-amine, and their bioactivities and stabilities were studied in vitro. The hypoglycemic effects and pharmacokinetics of these analogs after nasal administration were evaluated in type 2 diabetic animal models. PEG-Ex4 analogs had 3.1-, 3.8-, and 5.9-fold increased stabilities in rat nasal homogenates than Ex4. However, Lys²7-PEG(1k)-Ex4 was found to have well-preserved bioactivities (83.3% potency vs. Ex4), and other analogs were found to have much lower bioactivities than Lys²7-PEG(1k)-Ex4. In particular, the in vivo pharmacokinetic parameters of Lys²7-PEG(1k)-Ex4 in intranasally administered rats were significantly improved by PEGylation. Area under the curve (AUC) values of Lys²7-PEG(1k)-Ex4 were 33.6-fold higher and circulating t(1/2) values was 27.1-fold higher than Ex4. But, other analogs were not effectively absorbed via the intranasal route, because the higher molecular weight PEG (over 2 kDa) limited intranasal absorption. Finally, in vivo hypoglycemic experiment showed that Lys²7-PEG(2k)-, Lys²7-PEG(5k)-Ex4 had significantly lower hypoglycemic efficacies than Lys²7-PEG(1k)-Ex4, probably because of their lower intrinsic bioactivities and intranasal absorptions. Taken together, our findings suggest that the site-specific conjugation of appropriately sized PEG (1 kDa) substitution onto peptides like Ex4 offers two advantages for deliveryvia the intranasal route, namely, increased stability and extended circulating half-life.

PEGylated TNF-related apoptosis-inducing ligand (TRAIL) for effective tumor combination therapy.

Although PEGylated TNF-related apoptosis-inducing ligand (PEG-TRAIL) has good tumor cell specificity and stability, its therapeutic potential is restricted by the development of tumor cell resistance. The purpose of this study was to develop an effective combination therapy with sustained biological activity based on microspheres. Doxorubicin (DOX), PEG-TRAIL, and DOX plus PEG-TRAIL (dual agent) were microencapsulated into poly (lactic-co-glycolic acid) (PLGA) microspheres using a double-emulsion solvent extraction method. Prepared dual agent microspheres showed the encapsulation efficiency 69.4 ± 2.3 for DOX and 87.7 ± 2.9% for PEG-TRAIL. Potential anti-tumor efficacy of this system was investigated in vitro and in vivo in a human colon cancer (HCT116) and in a human prostate cancer (PC-3). DOX and PEG-TRAIL release from dual agent microspheres were biologically active and significantly inhibited the TRAIL-sensitive HCT116 and resistant PC-3 cells in vitro. Dual agent microspheres simultaneous delivery of DOX and PEG-TRAIL was superior to all other DOX or PEG-TRAIL microspheres in vivo. A single local injection of PLGA microspheres loaded with low amounts of DOX, PEG-TRAIL, or dual agent resulted in 14.8, 30.2, and 63.6% reductions in HCT116 tumor volume and 20.4, 14.2, and 67.7% reductions in PC-3 tumor volume at 35 days. Our findings show that dual agent microspheres offer a promising means of delivering DOX and PEG-TRAIL to tumor sites.

PEGylated TNF-related apoptosis-inducing ligand (TRAIL) analogues: pharmacokinetics and antitumor effects.

The low stability and fast clearance of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) are the main obstacles to its implementation as an antitumor agent. Here, we attempted to improve its pharmacokinetic and pharmacodynamic profiles by using PEGylation. N-terminal PEGylated TRAIL (PEG-TRAIL) was synthesized using 2, 5, 10, 20, and 30 kDa PEG. Antitumor effect assessments in HCT116 tumor bearing nude mice showed that all PEG-TRAIL analogues efficiently suppressed mean tumor growth, with mean tumor growth inhibition (TGI) values (5K-, 20K-, 30K-PEG-TRAIL) of 43.5, 61.7, and 72.3%, respectively. In particular, 30K-PEG-TRAIL was found to have antitumor efficacy for five days after a single administration (1 mg/mouse, i.p.). The different antitumor effects of these PEG-TRAIL analogues were attributed to augmented pharmacokinetics and metabolic resistance. All analogues were found to have higher metabolic stabilities in rat plasma, extended pharmacokinetic profiles, and greater circulating half-lives (3.9, 5.3, 6.2, 12.3, and 17.7 h for 2, 5, 10, 20, and 30K-PEG-TRAIL, respectively, versus 1.1 h for TRAIL, i.p.) in ICR mice. Our findings suggest that TRAIL derivatized with PEG of an appropriate M(w) might be useful antitumor agent with protracted activity.

Mono-PEGylated dimeric exendin-4 as high receptor binding and long-acting conjugates for type 2 anti-diabetes therapeutics.

Dimerization is viewed as the most effective means of increasing receptor binding affinity, and both dimerization and PEGylation effectively prolong the life spans of short-lived peptides and proteins in vivo by delaying excretion via the renal route. Here, we describe the high binding affinities of two long-acting exendin-4 (Ex4) conjugates, dimerized Ex4 (Di-Ex4) and PEGylated Di-Ex-4 (PEG-Di-Ex4). Di-Ex4 and PEG-Di-Ex4 were prepared using cysteine and amine residue specific coupling reactions using Ex4-Cys, bisMal-NH(2), and activated PEG. The Ex4 conjugates produced were of high purity (>98.5%), as determined by size-exclusion chromatography and MALDI-TOF mass spectrometry. The receptor binding affinity of Di-Ex4 on RIN-m5F cells was 3.5-fold higher than that of Ex4, and the in vivo antihyperglycemic efficacy of Di-Ex4 was also greater than that of native Ex4 in type 2 diabetic db/db mice. Furthermore, Di-Ex4 and PEG-Di-Ex4 were found to have greater blood circulating t(1/2) and AUC(inf) values than native Ex4 by 2.7- and 13.7-fold, and by 4.0- and 17.3-fold, respectively. Accordingly, hypoglycemic durations were greatly increased to 15.0 and 40.1 h, respectively, at a dose of 25 nmol/kg (native Ex4 7.3 h). The results of this study show that combined dimerization and PEGylation are effective when applied to Ex4, and suggest that PEG-Di-Ex4 has considerable potential as a type 2 anti-diabetic agent.

Improved biological half-life and anti-tumor activity of TNF-related apoptosis-inducing ligand (TRAIL) using PEG-exposed nanoparticles.

TRAIL has received considerable attention as a potential anti-cancer agent due to its specific ability to target tumors. However, recombinant TRAIL has several limitations, such as, its short biological half-life, its inherent instability, and its potential hepatotoxicity. In this study, we developed a sustained release nanoparticle formulation of TRAIL and investigated its therapeutic effects in tumor-bearing mice. TRAIL-loaded nanoparticles (NPs) were prepared by mixing PEGylated heparin (PEG-HE), poly-L-lysine (PLL), and TRAIL. NPs prepared by the ionic interaction between polymer and TRAIL showed uniform spherical structures of diameter 213.3 ± 9.7 nm and a surface charge of 5.33 ± 1.2 mV. An in vitro study of the bioactivity of TRAIL in NPs showed that TRAIL-loaded PEG-HE/PLL NPs (TRAIL-PEG-NPs) were slightly less cytotoxic than TRAIL in vitro. To investigate pharmacokinetic parameters, TRAIL and TRAIL-PEG-NPs were intravenously injected into SD rats. The PEG-NP-based formulation demonstrated a 28.3 fold greater half-life than TRAIL alone. To evaluate the anti-tumor effect, TRAIL, TRAIL-loaded HE/PLL NPs (TRAIL-NPs), and TRAIL-PEG-NPs were intravenously injected into HCT-116 tumor-bearing BALB/c athymic mice. The TRAIL-PEG-NP formulation efficiently suppressed tumor growth (>70%), and histological findings confirmed that NPs induced significant tumor cell apoptosis without inducing liver toxicity. The PEG-exposed NP fabrication method applied in this study could be widely applied to protein and peptide delivery systems.

Preparation and characterization of water-soluble albumin-bound curcumin nanoparticles with improved antitumor activity.

Curcumin (CCM), a yellow natural polyphenol extracted from turmeric (Curcuma longa), has potent anti-cancer properties as has been demonstrated in various human cancer cells. However, the widespread clinical application of this efficient agent in cancer and other diseases has been limited by its poor aqueous solubility and bioavailability. In this study, we prepared novel CCM-loaded human serum albumin (HSA) nanoparticles (CCM-HSA-NPs) for intravenous administration using albumin bound technology. Field emission scanning electron microscopy (FE-SEM) and dynamic light scattering (DLS) investigation confirmed a narrow size distribution in the 130-150nm range. Furthermore, CCM-HSA-NPs showed much greater water solubility (300-fold) than free CCM, and on storage, the biological activity of CCM-HSA-NPs was preserved with negligible activity loss. In vivo distributions and vascular endothelial cells transport studies demonstrated the superiority of CCM-HSA-NPs over CCM. Amounts of CCM in tumors after treatment with CCM-HSA-NPs were about 14 times higher at 1h after injection than that achieved by CCM. Furthermore, vascular endothelial cell binding of CCM increased 5.5-fold, and transport of CCM across a vascular endothelial cell monolayer by Transwell testing was 7.7-fold greater for CCM-HSA-NPs than CCM. Finally, in vivo antitumor tests revealed that CCM-HSA-NPs (10 or 20mg/kg) had a greater therapeutic effect (50% or 66% tumor growth inhibition vs. PBS-treated controls) than CCM (18% inhibition vs. controls) in tumor xenograft HCT116 models without inducing toxicity. We attribute this potent antitumor activity of CCM-HSA-NPs to enhanced water solubility, increased accumulation in tumors, and an ability to traverse vascular endothelial cell.

PEGylated TNF-related apoptosis-inducing ligand (TRAIL)-loaded sustained release PLGA microspheres for enhanced stability and antitumor activity.

The purpose of this work was to develop an effective PEGylated TNF-related apoptosis-inducing ligand (PEG-TRAIL) delivery system for antitumor therapy based on local injection to tumor sites that has a sustained effect without protein aggregation or an initial release burst. The authors designed poly (lactic-co-glycolic) acid (PLGA) microspheres that deliver PEG-TRAIL locally and continuously at tumor sites with sustained biological activity and compared its performance with that of TRAIL microspheres. TRAIL or PEG-TRAIL was microencapsulated into PLGA microspheres using a double-emulsion solvent extraction method. Prepared TRAIL and PEG-TRAIL microspheres showed entirely spherical, smooth surfaces. However, PEG-TRAIL microspheres exhibited a 2.07-fold higher encapsulation efficiency than TRAIL microspheres, and exhibited a tri-phasic in vitro release profile with a lower initial burst (15.8%) than TRAIL microspheres (42.7%). Furthermore, released PEG-TRAIL showed a continued ability to induce apoptosis over 14 days. In vivo pharmacokinetic studies also demonstrated that PEG-TRAIL microspheres had a sustained release profile (18 days), and that the steady-state concentration of PEG-TRAIL in rat plasma was reached at day 3 and maintained until day 15; its steady-state concentration in rat plasma changed from 1444.3 ± 338.4 to 2697.7 ± 419.7 pg/ml. However, TRAIL microspheres were released out within 2 days after administration. Finally, in vivo antitumor tests revealed that tumor growths were significantly more inhibited by a single dose of PEG-TRAIL microspheres than TRAIL microspheres when delivered at 300 µg of TRAIL/mouse. Tumors taken from mouse treated with PEG-TRAIL microspheres showed 78.3% tumor suppression at 24 days, and this was 3.02-fold higher than that observed for TRAIL microspheres (25.9% tumor inhibition). Furthermore, these improved pharmaceutical characteristics of PEG-TRAIL microspheres resulted in superior therapeutic effects without detectable side effects. These findings strongly suggest that PEG-TRAIL microspheres offer a new therapeutic strategy for the treatment of cancers.

Preparation and characterization of Apo2L/TNF-related apoptosis-inducing ligand-loaded human serum albumin nanoparticles with improved stability and tumor distribution.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has received considerable attention as a potential anticancer agent. However, recombinant Apo2L/TRAIL has several limitations, which include a weak pharmacokinetic profile, namely, a short biological half-life and rapid renal clearance, and an inability to form a homotrimeric structure. In this research, we attempted to develop a sustained release nanoparticle (NP) formulation that stabilizes Apo2L/TRAIL and preserves its antitumor activity. Apo2L/TRAIL-loaded human serum albumin (HSA) NPs were prepared using a desolvation technique optimized by particle size, zeta-potential, and entrapment efficiency. Apo2L/TRAIL in HSA-NPs continuously released over 24 h at 37°C in phosphate buffered saline and rat plasma condition, and the biological activity of Apo2L/TRAIL-HSA-NPs was preserved (IC(50) = 67.2 ng/mL versus Apo2L/TRAIL IC(50) = 55.4 ng/mL) with negligible activity loss. Furthermore, in vivo pharmacokinetic profiles and tumor distribution demonstrated the superiority of Apo2L/TRAIL-HSA-NPs over Apo2L/TRAIL. The circulating half-life period was significantly prolonged from 9.8 to 90.7 min (9.2-fold enhancement), and drug bioavailability was clearly enhanced on the basis of area under the curve analysis (2.7-fold). And tumor distribution of Apo2L/TRAIL-HSA-NPs was also increased at 1 h after injection, which was about 14-fold (1-h point) over that of Apo2L/TRAIL. These results show that Apo2L/TRAIL-loaded HSA-NPs should be considered as potential long-acting cancer agents.

Optimizing the binding activity of the AP2/ERF transcription factor with the GCC box element from Brassica napus by directed evolution.

In this study, we cloned the ERF-B3 subfamily transcription factor gene BnaERF-B3-hy15 from Brassica napus L. Huyou15. This 600 bp gene encodes a 199 amino acid classic ethylene responsive factor (ERF), which shown no binding or very weak binding GCC box-binding activity by the yeast one-hybrid assay. We used gene shuffling and the yeast one-hybrid system to obtain three mutated sequences that can bind to the GCC box. Sequence analysis indicated that two residues, Gly156 in the AP2 domain and Phe62 at the N-terminal domain were mutated to arginine and serine, respectively. Changes of Gly156 to arginine and Phe62 to serine increased the GCCbinding activity of BnaERF-B3-hy15 and the alter of Gly156 to arginine changed the AP2-domain structure of BnaERF-B3- hy15.