Pelvic organ prolapse (POP) remains a great therapeutic challenge with no optimal treatment available. Tissue maintenance and remodelling are performed by fibroblasts, therefore altered cellular ...functionality may influence tissue quality. In this study, we evaluated functional characteristics of fibroblastic cells from tissues involved in POP. To rule out normal ageing tissue degeneration, biopsies from 18 premenopausal women were collected from the precervical region (non-POP site) after hysterectomy of 8 healthy and 10 POP cystocele cases (POP-Q stage ≥ II). Extra tissues from the prolapsed sites were taken in the POP cases to distinguish between intrinsic and acquired cellular defects. Twenty-eight primary fibroblastic cultures were studied in vitro. A contractility assay was used to test fibroblast-mediated collagen contraction. Cellular mechanoresponses on collagen-coated or uncoated substrates were evaluated by measuring matrix remodelling factors at protein or gene expression levels. No differences were found between fibroblasts from the controls and the non-POP site of the case group. Fibroblastic cells from the prolapsed site showed delayed fibroblast-mediated collagen contraction and lower production of matrix metalloproteinase-2 (MMP-2) on collagen-coated plates. On uncoated surfaces the gene MMP-2 and its tissue inhibitor of metalloproteinases-2 were up-regulated in POP site fibroblastic cells. In conclusion, fibroblastic cells derived from prolapsed tissues of patients with cystocele, display altered in vitro functional characteristics depending on the surface substrate and compared with non-prolapsed site. This implies an acquired rather than an intrinsic defect for most patients with cystocele, and should be taken into account when trying to improve treatments for POP.
Biocompatibility of artificial lungs can be improved by endothelialization of hollow fibers. Bioavailability of growth-inducing and anti-thrombotic agents on the hollow fiber–blood interface inhibits ...thrombosis. We investigated if nanoliposomal growth-inducing growth hormone (nGH) and anti-thrombotic sodium nitrite (nNitrite) incorporation into collagen-coating on silicone hollow fibers improves blood biocompatibility by increasing endothelial cell growth and nitrite bioavailability under flow. Nitrite production rate was assessed under varying flow conditions. Finite element (FE) modeling was used to simulate nitrite transport within the parallel-plate flow chamber, and nitrite bioavailability on the fiber–blood interface at 1–30 dyn/cm
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shear stress. Endothelial cell number on fibers coated with nNitrite-nGH-collagen conjugate was 1.5-fold higher than on collagen-coated fibers. For collagen-coated fibers, nitrite production reached a maximum at 18 dyn/cm
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shear stress. When fibers were coated with nNitrite-nGH-collagen conjugate, nitrite production increased continuously by increasing shear stress. FE modeling revealed that nitrite concentrations at the fiber–blood interface were affected by shear stress-induced nitrite production, and diffusion/convection-induced nitrite removal. Highest nitrite concentrations and lowest thrombus deposition were observed on fibers coated with nNitrite-nGH-collagen conjugate exposed to 6–12 dyn/cm
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shear stress. In conclusion, our results suggest that nNitrite-nGH-Col conjugate coatings promote endothelialization of silicone hollow fibers in biohybrid artificial lungs.
To achieve re-osseointegration on implant surfaces exposed to peri-implant infections, treatment should re-establish biocompatibility. The aim of this study was to test whether air powder abrasive ...treatment (APA) using osteoconductive powders can, in addition to cleaning, increase the biocompatibility of the contaminated implant surface. 96 in-vitro Ca-precipitated, organic-film-layer-coated SLA titanium discs were treated by APA using Erythritol, Hydroxylapatite (HA) and Biocalcium Phosphate (BioCaP) powders (n=16 per group). 6 treatment modalities were created (HA or Erythritol cleaning with/without BioCaP coating). MC3T3-E1cells were seeded on discs, and cell attachment, viability, proliferation and differentiation were evaluated. Pristine discs were used as control1. Contaminated and non-treated discs were used as control2. The cells were stretched and attached in all test groups. The cell viability and proliferation (DNA amount) in all test groups were significantly higher than in the pristine and contaminated disc groups. There was no significant difference between the test groups. The differentiation (ALP activity) of the cells on treated discs was significantly higher than on the contaminated discs but lower than in the pristine group. The cell viability in control2 was significantly lower than the control1. The APA with osteoconductive powder on contaminated titanium surfaces promoted the cell viability, proliferation and differentiation of the MC3T3-E1cells. The biocompatibility of the surface was higher than that of the contaminated discs. The tested aspects of cell response, with the exception of differentiation, reached to the level of the pristine surface. The in-vitro results showed that APA with osteoconductive powders could be a promising method for implant surface treatment.
Surface modification by functional groups promotes endothelialization in biohybrid artificial lungs, but whether it affects endothelial cell stability under fluid shear stress, and the release of ...anti-thrombotic factors, e.g. nitric oxide (NO), is unknown. We aimed to test whether surface-modified silicone tubes containing different functional groups, but similar wettability, improve collagen immobilization, endothelialization, cell stability and cell-mediated NO-release. Peroxide, carboxyl, and amine-groups increased collagen immobilization (41-76%). Only amine-groups increased ultimate tensile strength (2-fold). Peroxide and amine enhanced (1.5-2.5 fold), but carboxyl-groups decreased (2.9-fold) endothelial cell number after 6 d. After collagen immobilization, cell numbers were enhanced by all group-modifications (2.8-3.8 fold). Cells were stable under 1 h-fluid shear stress on amine, but not carboxyl or peroxide-group-modified silicone (>50% cell detachment), while cells were also stable on carboxyl-group-modified silicone with immobilized collagen. NO-release was increased by peroxide and amine (1.1-1.7 fold), but decreased by carboxyl-group-modification (9.8-fold), while it increased by all group-modifications after collagen immobilization (1.8-2.8 fold). Only the amine-group-modification changed silicone stiffness and transparency. In conclusion, silicone-surface modification of blood-contacting parts of artificial lungs with carboxyl and amine, but not peroxide-groups followed by collagen immobilization allows the formation of a stable functional endothelial cell layer. Amine-group-modification seems undesirable since it affected silicone's physical properties.
Highlights • The matrix composition of the three cartilaginous structures that constitute the TMJ was different, both at the tissue and cellular level. • Collagen type II and proteoglycan content of ...the condyle matrix differentiated this type of matrix with that of the disc and fossa cartilage. • The cultured cells from the fossa, disc, and condyle cartilage displayed a similar phenotype as the cells embedded in their native tissue.
Introduction and hypothesis
Little is known about dynamic cell-matrix interactions in the context of pathophysiology and treatments for pelvic organ prolapse (POP). This study sought to identify ...differences between fibroblasts from women with varying degrees of prolapse in reaction to mechanical stimuli and matrix substrates in vitro.
Methods
Fibroblasts from the vaginal wall of three patients with POP Quantification (POP-Q) system stages 0, II, and IV were stretched on artificial polymer substrates either coated or not coated with collagen I. Changes in morphology and anabolic/catabolic compounds that affect matrix remodelling were evaluated at protein- and gene-expression levels. Statistical analysis was performed using one-way analysis of variance (ANOVA), followed by Tukey-Kramer’s post hoc test.
Results
POP fibroblasts show delayed cell alignment and lower responses to extracellular matrix remodelling factors at both enzymatic- and gene-expression levels compared with healthy fibroblasts.
Conclusion
POP fibroblasts, when compared with healthy cells, show differential mechanoresponses on two artificial polymer substrates. This should be taken into account when designing or improving implants for treating POP.
Abstract
Context: During osteoarthritis (OA), chondrocytes undergo de-differentiation, resulting in the acquisition of a fibroblast-like morphology, decreased expression of collagen type II (colII) ...and aggrecan, and increased expression of collagen type I (colI), metalloproteinase 13 (MMP13) and nitric oxide synthase (eNOS). Notch signaling plays a crucial role during embryogenesis. Several studies showed that Notch is expressed in adulthood. Objective: The aim of our study was to confirm the involvement of Notch signaling in human OA at in vitro and ex vivo levels. Materials and methods: Normal human articular chondrocytes were cultured during four passages either treated or not with a Notch inhibitor: DAPT. Human OA cartilage was cultured with DAPT for five days. Chondrocytes secreted markers and some Notch pathway components were analyzed using Western blotting and qPCR. Results: Passaging chondrocytes induced a decrease in the cartilage markers: colII and aggrecan. DAPT-treated chondrocytes and OA cartilage showed a significant increase in healthy cartilage markers. De-differentiation markers, colI, MMP13 and eNOS, were significantly reduced in DAPT-treated chondrocytes and OA cartilage. Notch1 expression was proportional to colI, MMP13 and eNOS expression and inversely proportional to colII and aggrecan expression in nontreated cultured chondrocytes. Notch ligand: Jagged1 increased in chondrocytes culture. DAPT treatment resulted in reduced Jagged1 expression. Notch target gene HES1 increased during chondrocyte culture and was reduced when treated with DAPT. Conclusion: Targeting Notch signaling during OA might lead to the restitution of the typical chondrocyte phenotype and even to chondrocyte redifferentiation during the pathology.
Background aims Stem cell therapies are being evaluated as promising alternatives for cartilage regeneration. We investigated whether stromal vascular fraction cells (SVF) from the infrapatellar ...(Hoffa) fat pad are suitable for a one-step surgical procedure to treat focal cartilage defects. Methods SVF was harvested from patients undergoing knee arthroplasty ( n = 53). Colony-forming unit (CFU) assays, growth kinetics and surface marker profiles were determined, and the chondrogenic differentiation capacity of freshly isolated SVF was assessed after seeding in three-dimensional poly ( l -lactic-co-ϵ-caprolactone) scaffolds. Results SVF yield per fat pad varied between 0.55 and 16 × 106 cells. CFU frequency and population doubling time were 2.6 ± 0.6% and ±2 days, respectively. Surface marker profiles matched those of subcutaneous-derived adipose-derived stem cells (ASC). CFU from Hoffa SVF showed differentiation toward osteogenic and adipogenic lineages. Cartilage differentiation was confirmed by up-regulation of the cartilage genes sox9, aggrecan, collagen type II and cartilage oligomeric matrix protein (COMP), collagen II immunostaining, Alcian Blue staining and glycosaminoglycan production. Compared with passaged cells, SVF showed at least similar chondrogenic potential. Conclusions This study demonstrates that SVF cells from the infrapatellar fat pad are suitable for future application in a one-step surgical procedure to regenerate cartilage tissue. SVF shows similar favorable characteristics as cultured ASC, and chondrogenic differentiation even appears to be slightly better. However, because of variable harvesting volumes and yields, SVF from the infrapatellar fat pad might only be applicable for treatment of small focal cartilage defects, whereas for larger osteoarthritic defects subcutaneous adipose tissue depot would be preferable.
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