Mussel-inspired protein-mediated surface functionalization of electrospun nanofibers for pH-responsive drug delivery

pH-responsive drug delivery systems could mediate drug releasing rate by changing the pH values at specific times as per the pathophysiological need of the disease. This paper demonstrates that a mussel-inspired protein polydopamine coating can tune the loading and releasing rate of charged molecules from electrospun poly(ε-caprolactone) (PCL) nanofibers in solutions with different pH values. In vitro release profiles show that the positive charged molecules release significantly faster in acidic than those in neutral and basic environments within the same incubation time. The results of fluorescein diacetate staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays show the viability of cancer cells after treatment with doxorubicin-released media at different pH values qualitatively and quantitatively, indicating that the media containing doxorubicin that were released in solutions at low pH values could kill a significantly higher number of cells than those released in solutions at high pH values. Together, the pH-responsive drug delivery systems based on polydopamine-coated PCL nanofibers could have potential application in the oral delivery of anticancer drugs for treating gastric cancer and in vaginal delivery of anti-viral drugs or anti-inflammatory drugs, which could raise their efficacy, deliver them to the specific target and minimize their toxic side effects.

A study comparing three different laser-assisted hatching techniques

PURPOSE OF INVESTIGATION

Laser-assisted hatching (LAH) is recognized as a useful technology to improve clinical pregnancy rates and implantation rates. This study reports the differences between a new LAH method and two conventional LAH techniques.

MATERIALS AND METHODS

The authors studied 151 patients with repeated implantation failure, who were divided into three groups.

RESULTS

In group 1, the zona pellucida (ZP) was opened using LAH (n = 52). In group 2, laser-assisted thinning was performed to dissolve the outer layer of the ZP (n = 49). In group 3, laser-assisted thinning was performed to dissolve the inner layer of the ZP (n = 50). The clinical pregnancy rates and implantation rates among the groups were compared. The results demonstrate that there are significant differences in the clinical pregnancy rates and implantation rates between group 3 and the other two groups.

CONCLUSION

Performing laser-assisted thinning to dissolve the inner layer of the ZP markedly increases the pregnancy rates and implantation rates of patients with repeated implantation failure.

Open reduction and internal fixation versus external fixation for unstable distal radial fractures: a meta-analysis

PURPOSE

To compare the clinical outcomes of open reduction and internal fixation (ORIF) versus the ones of closed reduction and external fixation (EF) in the treatment of distal radial fractures.

METHODS

We performed a meta-analysis of randomized controlled trials that compared the clinical results of ORIF to EF in the treatment of distal radial fractures. A systemic retrieve from PubMed, EMBASE, OVID and Cochrane Collaboration CENTRAL database resulted in 11 studies with 824 patients. We thus performed data synthesis using RevMan (version 5.1).

RESULTS

Superior statistical differences were observed for DASH scores (at 3, 6 and 12 months follow-up) grip strength (at 3 months follow-up), volar tilt (at 12 months follow-up), flexion and supination (at 3 months follow-up), and extension (at 3 and 6 months follow-up) in ORIF patients group, compared with those in EF group. We also found a significantly higher risk of infection associated with EF. There was no significant difference in the incidence of malunion and median nerve dysfunction.

CONCLUSION

Regarding surgical fixation of unstable distal radius fractures, ORIF yields significantly better subjective outcome (DASH scores) the first year after operation, restoration of anatomic volar tilt, and forearm flexion and extension at the end of the follow-up period. However, EF results in higher incidence of infection compared to ORIF. ORIF is equal to EF for either grip strength, or range of motion of the injured wrist, or incidence of malunion or median nerve dysfunction at the end of the follow-up period.

LEVEL OF EVIDENCE

Level II. Therapeutic study.

Inhibition of activin receptor-like kinase 5 induces matrix metallopeptidase 9 expression and aggravates lipopolysaccharide-induced pulmonary injury in mice

BACKGROUND

TGF-β (Transforming Growth Factor-β) mediates its biological effects through members of activin receptor-like kinase (ALK) family and TGF-β/Smad3 signaling link inflammation to pulmonary fibrosis.

AIM

The aim of this study was to evaluate the role of SB431542 as a specific inhibitor of Activin receptor-Like Kinase 5 (ALK5) in pneumonic injury.

MATERIALS AND METHODS

Anesthetized and endo-tracheally intubated C57BL/6 mice were randomized to three groups: the control group with intra-tracheal instillation of 1.5 mg/kg normal saline (NS); LPS stimulation group with intra-tracheal instillation of 3 mg/kg LPS (lipopolysaccharide); and LPS+SB431542 group with intra-peritoneal (i.p.) injection of 4.2 mg/kg SB431542 1 h before intra-tracheal instillation of 3 mg/kg LPS. The lung tissue was obtained 6 h after injury, and the degree of pulmonary injury was evaluated by pathologic scoring. The lung wet/dry weight ratio was measured. TNF-α, IL-1β, and MMP-9 (matrix metallopeptidase-9) mRNA expression levels were assayed by real time PCR (polymerase chain reaction). The content of MMP-9 total protein was measured by Western blotting. The content of active MMP-9 was detected by gelatin zymography. Location of MMP-9 in mouse lung tissue was monitored by immunohistochemistry.

RESULTS

The results showed that (1) pathologic changes including interstitial pulmonary edema, neutrophil infiltration, alveolar edema and hemorrhage were observed 6 h after LPS instillation. The lung wet/dry weight rate and pathologic scores confirmed that SB431542 administration aggravated LPS injury to the mouse lung; (2) the amount of TNF-α and IL-1β mRNA expression in LPS groups was significantly higher than that in the control group, and the highest in LPS+SB431542 group; (3) the amount of MMP-9 mRNA and MMP-9 protein expression and active MMP-9 in the lung tissue of LPS groups was significantly higher than that in the control group 6 h after injury, and the highest in LPS+SB431542 group; and (4) MMP-9 expression was mainly observed in the airway epithelial cells, vascular smooth muscle cells and cytoplasm of inflammatory cells as shown by immunohistochemistry, and brownish yellow uniformed stained areas were also seen in the exudate from part of the alveoli.

CONCLUSIONS

These results indicate that blocking the activity of TGF-β/Smad pathway by specific inhibitor SB431542 of ALK5 promoted the releaser of large amounts of TNF-α, IL-1β and other pro-inflammatory cytokines from the lung tissue of mice sustaining acute lung injury (ALI). At the same time, the amount and activity of MMP-9 expression in the lung were increased, and MMP-9 expression was mainly located in the airway epithelial cells, vascular smooth muscle cells and inflammatory cells, causing increased permeability of the pulmonary blood vessels, degradation of the extracellular matrix and destruction of the normal lung tissue structures, which directly or indirectly promotes the progression of pulmonary inflammatory responses and aggravates ALI.

Gene expression profiling of dedifferentiated human articular chondrocytes in monolayer culture

OBJECTIVE

When primary chondrocytes are cultured in monolayer, they undergo dedifferentiation during which they lose their phenotype and their capacity to form cartilage. Dedifferentiation is an obstacle for cell therapy for cartilage degeneration. In this study, we aimed to systemically evaluate the changes in gene expression during dedifferentiation of human articular chondrocytes to identify underlying mechanisms.

METHODS

RNA was isolated from monolayer-cultured primary human articular chondrocytes at serial passages. Gene expression was analyzed by microarray. Based on the microarray analysis, relevant genes and pathways were identified. Their functions in chondrocyte dedifferentiation were further investigated.

RESULTS

In vitro expanded human chondrocytes showed progressive changes in gene expression. Strikingly, an overall decrease in total gene expression was detected, which was both gradual and cumulative. DNA methylation was in part responsible for the expression downregulation of a number of genes. Genes involved in many pathways such as the extracellular-signal-regulated kinase (ERK) and Bone morphogenetic protein (BMP) pathways exhibited significant changes in expression. Inhibition of ERK pathway did not show dramatic effects in counteracting dedifferentiation process. BMP-2 was able to decelerate the dedifferentiation and reinforce the maintenance of chondrocyte phenotype in monolayer culture.

CONCLUSION

Our study not only improves our knowledge of the intricate signaling network regulating maintenance of chondrocyte phenotype, but also contributes to improved chondrocyte expansion and chondrogenic performance for cell therapy.

Effect of clopidogrel with or without omeprazole in patients with carotid artery stenting

BACKGROUND

Recent concerns have been raised about the potential for proton pump inhibitors (PPIs) to blunt the efficacy of clopidogrel. We observed the effect of clopidogrel plus aspirin with or without omeprazole in patients with carotid stenoses after they received placement of carotid stents.

METHODS

Sixty-four consecutive patients treated with percutaneous carotid artery stenting (CAS) comprised the sample. All enrolled patients underwent the C13 urea breath test (C13 UBT) before CAS. Patients with Helicobacter pylori infection and a history of peptic ulcer were assigned dual antiplatelet combination with omeprazole. Others received dual antiplatelet without omeprazole. Transcranial Doppler and ultrasonography were performed to assess the middle cerebral artery and carotid artery in follow-up at three months and six months.

RESULTS

Eight patients had gastrointestinal bleeding; the event rate was 22.6% without omeprazole and 3.8% with omeprazole. The rate of gastrointestinal bleeding was reduced with omeprazole as compared without omeprazole (p = 0.026, p < 0.05). The two groups did not differ significantly in the rate of in-stent restenosis and thrombus through transcranial Doppler and ultrasonography.

CONCLUSION

Among patients receiving dual antiplatelet therapy, prophylactic use of omeprazole reduced the rate of upper gastrointestinal bleeding. There was no apparent interaction between clopidogrel and omeprazole in patients with carotid artery stenting.

βA3/A1-Crystallin controls anoikis-mediated cell death in astrocytes by modulating PI3K/AKT/mTOR and ERK survival pathways through the PKD/Bit1-signaling axis

During eye development, apoptosis is vital to the maturation of highly specialized structures such as the lens and retina. Several forms of apoptosis have been described, including anoikis, a form of apoptosis triggered by inadequate or inappropriate cell–matrix contacts. The anoikis regulators, Bit1 (Bcl-2 inhibitor of transcription-1) and protein kinase-D (PKD), are expressed in developing lens when the organelles are present in lens fibers, but are downregulated as active denucleation is initiated. We have previously shown that in rats with a spontaneous mutation in the Cryba1 gene, coding for βA3/A1-crystallin, normal denucleation of lens fibers is inhibited. In rats with this mutation (Nuc1), both Bit1 and PKD remain abnormally high in lens fiber cells. To determine whether βA3/A1-crystallin has a role in anoikis, we induced anoikis in vitro and conducted mechanistic studies on astrocytes, cells known to express βA3/A1-crystallin. The expression pattern of Bit1 in retina correlates temporally with the development of astrocytes. Our data also indicate that loss of βA3/A1-crystallin in astrocytes results in a failure of Bit1 to be trafficked to the Golgi, thereby suppressing anoikis. This loss of βA3/A1-crystallin also induces insulin-like growth factor-II, which increases cell survival and growth by modulating the phosphatidylinositol-3-kinase (PI3K)/AKT/mTOR and extracellular signal-regulated kinase pathways. We propose that βA3/A1-crystallin is a novel regulator of both life and death decisions in ocular astrocytes.

Antitumor effect of sFlt-1 gene therapy system mediated by Bifidobacterium Infantis on Lewis lung cancer in mice

Soluble fms-like tyrosine kinase receptor (sFlt-1) is a soluble form of extramembrane part of vascular endothelial growth factor receptor-1 (VEGFR-1) that has antitumor effects. Bifidobacterium Infantis is a kind of non-pathogenic and anaerobic bacteria that may have specific targeting property of hypoxic environment inside of solid tumors. The aim of this study was to construct Bifidobacterium Infantis-mediated sFlt-1 gene transferring system and investigate its antitumor effect on Lewis lung cancer (LLC) in mice. Our results demonstrated that the Bifidobacterium Infantis-mediated sFlt-1 gene transferring system was constructed successfully and the system could express sFlt-1 at the levels of gene and protein. This system could not only significantly inhibit growth of human umbilical vein endothelial cells induced by VEGF in vitro, but also inhibit the tumor growth and prolong survival time of LLC C57BL/6 mice safely. These data suggest that Bifidobacterium Infantis-mediated sFlt-1 gene transferring system presents a promising therapeutic approach for the treatment of cancer.

Skewing the Balance of Regulatory T-Cells and T-Helper 17 Cells in Breast Cancer Patients

This study investigated the distribution of interleukin (IL)-17-producing CD4+ T-cells (T-helper [Th17] cells) in relation to CD4+CD25+CD127− cells (regulatory T-cells [Treg]) in tumour-infiltrating lymphocytes (TILs) and peripheral blood mononuclear cells (PBMCs) from breast cancer patients. The Th17 and Treg cells were evaluated by flow cytometry and reported as a percentage of total CD4+ cells. In TILs from early breast cancer patients ( n = 12), the frequency of Th17 cells was significantly higher than in PBMCs (14.5 ± 7.2% versus 6.9 ± 2.1%). In TILs from patients with advanced breast cancer ( n = 15), the frequency of Th17 cells was also significantly higher than that in PBMCs (9.1 ± 5.7% versus 3.2 ± 2.3%) but lower compared with early disease. The Th17/Treg ratio in TILs was markedly increased in early versus advanced disease. In conclusion, Th17 and Treg cell accumulation in the tumour microenvironment of breast cancer occurred in early disease; Th17 cell infiltration gradually decreased and Treg cells accumulated with disease progression.