TGF-ß1, in association with the increased expression of connective tissue growth factor, induce the hypertrophy of the ligamentum flavum through the p38 MAPK pathway.

Hypertrophy of the ligamentum flavum (LF) is one of the key pathomechanisms of lumbar spinal stenosis (LSS). Transforming growth factor (TGF)-ß1 is abundantly expressed in hypertrophied degenerative LF tissues from LSS. However, the molecular mechanisms underling the association between TGF-ß1 and LF hypertrophy have not yet been fully elucidated. In this study, we investigated the important role of the mitogen-activated protein kinase (MAPK) pathway in the pathogenesis of LSS by analyzing the expression of connective tissue growth factor (CTGF) and extracellular matrix (ECM) components (collagen I and collagen III) in TGF-ß1-treated LF cells. Cell growth assay revealed that TGF-ß1, in association with CTGF, enhanced the the proliferation of LF cells, and we found that TGF-ß1 also elevated CTGF expression and subsequently enhanced the mRNA expression of collagen I and collagen III. The increased mRNA expression levels of CTGF, collagen I and collagen III were abolished by p38 inhibitors. Both immunofluorescence imaging and western blot analysis of p38 and p-p38 revealed the increased expression and phosphorylation of p38. Silencing the expression of p38 by siRNA in LF cells decreased the protein expression of p38, p-p38 and CTGF, as well as the mRNA expression of CTGF, collagen I and collagen III. Taken together, our findings indicate that TGF-ß1, in association with the increased expression of CTGF, contribute to the homeostasis of the ECM and to the hypertrophy of LF through the p38 MAPK pathway.

Porous nano-hydroxyapatite/collagen scaffold containing drug-loaded ADM-PLGA microspheres for bone cancer treatment.

To develop adriamycin (ADM)-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles in a porous nano-hydroxyapatite/collagen scaffold (ADM-PLGA-NHAC). To provide novel strategies for future treatment of osteosarcoma, the properties of the scaffold, including its in vitro extended-release properties, the inhibition effects of ADM-PLGA-NHAC on the osteosarcoma MG63 cells, and its bone repair capacity, were investigated in vivo and in vitro. The PLGA copolymer was utilized as a drug carrier to deliver ADM-PLGA nanoparticles (ADM-PLGA-NP). Porous nano-hydroxyapatite and collagen were used to materials to produce the porous nano-hydroxyapatite/collagen scaffold (NHAC), into which the ADM-PLGA-NP was loaded. The performance of the drug-carrying scaffold was assessed using multiple techniques, including scanning electron microscopy and in vitro extended release. The antineoplastic activities of scaffold extracts on the human osteosarcoma MG63 cell line were evaluated in vitro using the cell counting kit-8 (CCK8) method and live-dead cell staining. The bone repair ability of the scaffold was assessed based on the establishment of a femoral condyle defect model in rabbits. ADM-PLGA-NHAC and NHAC were implanted into the rat muscle bag for immune response experiments. A tumor-bearing nude mice model was created, and the TUNEL and HE staining results were observed under optical microscopy to evaluate the antineoplastic activity and toxic side effects of the scaffold. The composite scaffold demonstrated extraordinary extended-release properties, and its extracts also exhibited significant inhibition of the growth of osteosarcoma MG63 cells. In the bone repair experiment, no significant difference was observed between ADM-PLGA-NHAC and NHAC by itself. In the immune response experiments, ADM-PLGA-NHAC exhibited remarkable biocompatibility. The in vivo antitumor experiment revealed that the implantation of ADM-PLGA-NHAC in the tumor resulted in a improved antineoplastic effect and fewer adverse side effects than direct intraperitoneal injection of ADM. The ADM-PLGA-NHAC developed in this study exhibited excellent extended-release drug properties, bone repairing and antineoplastic efficacy, which make it a promising osteoconductivity material with the capability to inhibit osteosarcoma.

Characterization and bioavailability of tea polyphenol nanoliposome prepared by combining an ethanol injection method with dynamic high-pressure microfluidization.

Tea polyphenols are major polyphenolic substances found in green tea with various biological activities. To overcome their instability toward oxygen and alkaline environments, tea polyphenol nanoliposome (TPN) was prepared by combining an ethanol injection method with dynamic high-pressure microfluidization. Good physicochemical characterizations (entrapment efficiency = 78.5%, particle size = 66.8 nm, polydispersity index = 0.213, and zeta potential = -6.16 mv) of TPN were observed. Compared with tea polyphenol solution, TPN showed equivalent antioxidant activities, indicated by equal DPPH free radical scavenging and slightly lower ferric reducing activities and lower inhibitions against Staphylococcus aureus , Escerhichia coli , Salmonella typhimurium , and Listeria monocytogenes . In addition, a relatively good sustained release property was observed in TPN, with only 29.8% tea polyphenols released from nanoliposome after 24 h of incubation. Moreover, TPN improved the stability of tea polyphenol in alkaline solution. This study expects to provide theories and practice guides for further applications of TPN.

Improved in vitro digestion stability of (-)-epigallocatechin gallate through nanoliposome encapsulation.

(-)-Epigallocatechin gallate (EGCG) is unstable and degraded in near-neutral or alkaline fluids. To overcome its limitation, EGCG nanoliposome (EN) was prepared by an ethanol injection method combined with dynamic high-pressure microfluidization. EN possessed good physicochemical characterizations (high entrapment efficiency=92.1%, small average particle size=71.7nm, low polydispersity index=0.286 and zeta potential=-10.81mv). EN exhibited a relative good sustained release property. Stability of EGCG in simulated intestinal fluid (SIF) was significantly improved by nanoliposome encapsulation. After 1.5h incubating in SIF without or with pancreatin, the residual EGCG of EN was 31.2% and 47.7% respectively, but the residual EGCG in EGCG solution was only 3.4% and 3.5% respectively. The degenerations of in vitro antioxidant activities of EGCG were effectively slowed by nanoliposome encapsulation. This study expects to provide theories and practice guides for further applications of EN.