Anticancer and bone-enhanced nano-hydroxyapatite/gelatin/polylactic acid fibrous membrane with dual drug delivery and sequential release for osteosarcoma.

Surgical resection of osteosarcoma is always accompanied by residual metastasis of tumor cells and bone tissue defects. In this work, a novel kind of gelatin/polylactic acid (PLA) coaxial fiber membrane with a shell layer containing doxorubicin-loaded hydroxyapatite (DOX@nHAp) nanoparticles and a core layer containing Icariin (ICA) was developed for antitumor and bone enhancement at the defect site. Physical evaluation displayed that the composite membrane provided moderate hydrophilicity, enhanced tensile strength (Dry: 2-3 MPa, wet: 1-2 MPa) and elasticity (70-100 %), as well as increased specific surface area and pore volume (19.39 m2/g and 0.16 cm3/g). In SBF, DOX@nHAp in the fibers promoted biomineralization on the fiber surface. In in vitro evaluation, approximately 80 % of DOX had a short-term release during the first 8 days, followed by long-term release behavior of ICA for up to 40 days. CCK-8 results confirmed that the membrane could actively support MC3T3-E1 cells proliferation and was conductive to high alkaline phosphatase expression, while the viability of MG-63 cells was effectively inhibited to 50 %. Thus, the dual-loaded fibrous membrane with a coaxial structure and nHAp is a promising system for anticancer and defects reconstruction after osteosarcoma surgery.

Poly(ß-amino ester) Dual-Drug-Loaded Hydrogels with Antibacterial and Osteogenic Properties for Bone Repair.

In this study, we developed a poly(ß-amino ester) (PBAE) hydrogel for the double release of vancomycin (VAN) and total flavonoids of Rhizoma Drynariae (TFRD). VAN was covalently bonded to PBAE polymer chains and was released to enhance the antimicrobial effect first. TFRD chitosan (CS) microspheres were physically dispersed in the scaffold, TFRD was released from the microspheres, and osteogenesis was induced subsequently. The scaffold had good porosity (90.12 ± 3.27%), and the cumulative release rate of the two drugs in PBS (pH 7.4) solution exceeded 80%. In vitro antimicrobial assays demonstrated the antibacterial properties of the scaffold against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Besides these, cell viability assays indicated that the scaffold had good biocompatibility. Moreover, alkaline phosphatase and matrix mineralization were expressed more than in the control group. Overall, cell experiments confirmed that the scaffolds have enhanced osteogenic differentiation capabilities. In conclusion, the dual-drug-loaded scaffold with antibacterial and bone regeneration effects is promising in the field of bone repair.

Correction: Preparation and characterization of a novel drug-loaded Bi-layer scaffold for cartilage regeneration.

[This corrects the article DOI: 10.1039/D2RA00311B.].

Preparation and characterization of a novel drug-loaded Bi-layer scaffold for cartilage regeneration.

The incidence of articular cartilage defects is increasing year by year. In order to repair the cartilage tissue at the defect, scaffolds with nanofiber structure and biocompatibility have become a research hotspot. In this study, we designed and fabricated a bi-layer scaffold prepared from an upper layer of drug-dispersed gelatin methacrylate (GELMA) hydrogel and a lower layer of a drug-encapsulated coaxial fiber scaffold prepared from silk fiber (SF) and polylactic acid (PLA). These bi-layer scaffolds have porosity (91.26 ± 3.94%) sufficient to support material exchange and pore size suitable for cell culture and infiltration, as well as mechanical properties (2.65 ± 0.31 MPa) that meet the requirements of cartilage tissue engineering. The coaxial fiber structure exhibited excellent drug release properties, maintaining drug release for 14 days in PBS. In vitro experiments indicated that the scaffolds were not toxic to cells and were amenable to chondrocyte migration. Notably, the growth of cells in a bi-layer scaffold presented two states. In the hydrogel layer, cells grow through interconnected pores and take on a connective tissue-like shape. In the coaxial fiber layer, cells grow on the surface of the coaxial fiber mats and appeared tablet-like. This is similar to the structure of the functional partitions of natural cartilage tissue. Together, the bi-layer scaffold can play a positive role in cartilage regeneration, which could be a potential therapeutic choice to solve the current problems of clinical cartilage repair.

Esophageal Motor Dysfunctions in Gastroesophageal Reflux Disease and Therapeutic Perspectives.

Gastroesophageal reflux disease (GERD) is a very common disease, and the prevalence in the general population has recently increased. GERD is a chronic relapsing disease associated with motility disorders of the upper gastrointestinal tract. Several factors are implicated in GERD, including hypotensive lower esophageal sphincter, frequent transient lower esophageal sphincter relaxation, esophageal hypersensitivity, reduced resistance of the esophageal mucosa against the refluxed contents, ineffective esophageal motility, abnormal bolus transport, deficits initiating secondary peristalsis, abnormal response to multiple rapid swallowing, and hiatal hernia. One or more of these mechanisms result in the reflux of stomach contents into the esophagus, delayed clearance of the refluxate, and the development of symptoms and/or complications. New techniques, such as 24-hour pH and multichannel intraluminal impedance monitoring, multichannel intraluminal impedance and esophageal manometry, high-resolution manometry, 3-dimensional highresolution manometry, enoscopic functional luminal imaging probe, and 24-hour dynamic esophageal manometry, provide more information on esophageal motility and have clarified the pathophysiology of GERD. Proton pump inhibitors remain the preferred pharmaceutical option to treat GERD. The ideal target of GERD treatment is to restore esophageal motility and reconstruct the antireflux mechanism. This review focuses on current advances in esophageal motor dysfunction in patients with GERD and the influence of these developments on GERD treatment.

Gastroesophageal reflux disease and chronic cough: A possible mechanism elucidated by ambulatory pH-impedance-pressure monitoring.

BACKGROUND: The pathophysiological mechanism(s) of gastroesophageal reflux disease (GERD)-related chronic cough (CC) is unclear. We aimed to determine the mechanism of reflux-induced cough by synchronous monitoring of reflux episodes, esophageal motility, and cough. METHODS: Patients with GERD were prospectively enrolled and classified into GERD with CC (GERD-CC) and without CC (GERD) groups. Twenty-four-hour ambulatory pH-impedance-pressure monitoring was performed; the reflux patterns, esophageal motility during prolonged exposure to acid and characteristics of reflux episodes that induced coughing paroxysms were analyzed. KEY RESULTS: Thirty-one patients with GERD-CC and 47 with GERD were enrolled; all of whose monitoring results fulfilled the criteria for diagnosis of GERD. Patients with GERD-CC had higher reflux symptom scores, longer exposure to acid, higher DeMeester scores, and more frequent reflux episodes, proximal extent reflux detected by impedance, and higher percentage of strongly acidic reflux than patients in the GERD group (all P < .05). Of 63 reflux-cough episodes identified in the GERD-CC group, 74.6% of distal reflux and 67.0% of proximal reflux episodes were acidic. More patients had low pan-esophageal pressure in primary peristalsis (48.5% vs 11.8%, P = .000) and synchronous contraction in secondary peristalsis during prolonged exposure to acid in the GERD-CC than in the GERD group (63.9% vs 9.1%, P = .000). CONCLUSIONS & INFERENCES: Proximal acidic reflux and distal reflux-reflex are jointly associated with reflux-induced cough in patients with GERD. Low pan-esophageal pressure in primary peristalsis and synchronous contraction in secondary peristalsis may play important roles in GERD-associated chronic cough.

Sodium houttuyfonate inhibits LPS­induced mastitis in mice via the NF­κB signalling pathway.

Sodium houttuyfonate (SH) has been indicated to play an important anti­inflammatory role. Previous studies have confirmed that SH can inhibit the NF­κB pathway in lipopolysaccharide (LPS)­induced mastitis in bovine mammary epithelial cells. However, the effects of SH on LPS­induced mastitis in animals should be verified to further evaluate its actual value. In the present study, the anti­inflammatory effects of SH were investigated in mouse models and a mouse mammary epithelial cell line. Hematoxylin and eosin staining (H&E) showed that SH therapy significantly alleviated the pathological changes in mammary glands. Myeloperoxidase (MPO) activity analysis demonstrated that SH substantially decreased MPO activity in vivo. RT­qPCR results showed that SH reduced the expression of interleukin (IL)­1, IL­6 and tumor necrosis factor α both in vivo and in vitro. In addition, western blot results indicated that SH suppressed the phosphorylation of nuclear factor kappa­light­chain­enhancer of activated B­cells (NF­κB) p65 protein and reduced the degradation of inhibitor of kappa light polypeptide gene enhancer in B­cells alpha protein in vivo and in vitro. These results demonstrated that SH ameliorates LPS­induced mastitis by inhibiting the NF­κB pathway.

[Effects of aldosterone on osteoblast proliferation, differentiation and osteogenic gene expressions in vitro].

OBJECTIVE: To study the effect of aldosterone on cell proliferation, alkaline phosphatase (AKP) activity and osteogenic gene expression in rat osteoblasts and explore the mechanisms. METHODS: Osteoblasts isolated from the skull of neonatal SD rats by enzyme digestion were cultured and treated with different concentrations of aldosterone. The cell proliferation and AKP activity were evaluated using CCK-8 assay kit and AKP assay kit, respectively. The effects of aldosterone on mRNA and protein expressions of the osteogenic genes and epithelial sodium channel (ENaC) gene were investigated using semi-quantitative PCR and Western blotting. RESULTS: Compared with the control cells, the cells treated with 0.01-1.0 µmol/L aldosterone showed obviously enhanced proliferation while lower (1×10-3 µmol/L) or higher (10 µmol/L) concentrations of aldosterone did not significantly affect the cell proliferation. Aldosterone within the concentration range of 1×10-3 to 10 µmol/L did not cause significant changes in AKP activity in the osteoblasts. Treatment with 0.01 to 1.0 µmol/L aldosterone significantly upregulated the expressions of the osteogenic genes and α-ENaC gene at both the mRNA and protein levels. CONCLUSION: Aldosterone within the concentration range of 0.01-1.0 µmol/L stimulates the proliferation and osteogenic gene expressions and enhances α-ENaC gene expression in rat osteoblasts in vitro, suggesting the possibility that ENaC participates in aldosterone-mediated regulation of osteoblast functions.