Search results for "Biomaterials"

Combination of an allogenic and a xenogenic bone substitute material with injectable platelet-rich fibrin – A comparative in vitro study

2020

The aim of the in vitro study was a comparison of an allogenic (ABSM) and a xenogenic bone substitute material (XBSM) with and without injectable platelet-rich fibrin (ABSM-i-PRF & XBSM-i-PRF) on cell characteristics of human osteoblasts (HOB). Here, ABSM and XBSM (+ i-PRF = test; - i-PRF = control) were incubated with HOB for 3, 7 and 10 days. HOB viability, migration, proliferation and differentiation (RT-PCR on alkaline phosphatase (AP), bone morphogenetic protein 2 (BMP-2) and osteonectin (OCN)) were measured and compared between groups. At day 3, an increased viability, migration and proliferation was seen for ABSM-i-PRF. For viability and proliferation (days 7 and 10) and for mig…

The effect of adhesives on inflammatory immune-markers during renal injury healing

2017

Renal injury is common in abdominal trauma. Adhesives and sealants can be used to repair and preserve damaged organs. We describe the effect of three biomaterial treatments (TachoSil, GelitaSpon, and Adhflex) on injured renal tissue. Renal traumatic injuries were experimentally induced in male Wistar rats (n = 90) using a punch. Animals were divided into five groups: (1) sham noninjured (n = 3) and punch injury groups; (2) nontreated (n = 6); (3) TachoSil (n = 27); (4) GelitaSpon (n = 27); and (5) Adhflex (n = 27). Wound healing was evaluated 2, 6, and 18 days postinjury by inflammatory cytokines response, histopathological evolution of lesions, inflammatory reaction markers (CD68), and vas…

Implanted neonatal human dermal fibroblasts influence the recruitment of endothelial cells in mice

2012

The vascularization of new tissue within a reasonable time is a crucial prerequisite for the success of different cell- and material-based strategies. Considering that angiogenesis is a multi-step process involving humoral and cellular regulatory components, only in vivo assays provide the adequate information about vessel formation and the recruitment of endothelial cells. The present study aimed to investigate if neonatal human dermal fibroblasts could influence in vivo neovascularization. Results obtained showed that fibroblasts were able to recruit endothelial cells to vascularize the implanted matrix, which was further colonized by murine functional blood vessels after one week. The ve…

The effect of human osteoblasts on proliferation and neo-vessel formation of human umbilical vein endothelial cells in a long-term 3D co-culture on p…

2008

Angiogenesis is a key element in early wound healing and is considered important for tissue regeneration and for directing inflammatory cells to the wound site. The improvement of vascularization by implementation of endothelial cells or angiogenic growth factors may represent a key solution for engineering bone constructs of large size. In this study, we describe a long-term culture environment that supports the survival, proliferation, and in vitro vasculogenesis of human umbilical vein endothelial cells (HUVEC). This condition can be achieved in a co-culture model of HUVEC and primary human osteoblasts (hOB) employing polyurethane scaffolds and platelet-rich plasma in a static microenvir…

Paracrine Effects Influenced by Cell Culture Medium and Consequences on Microvessel-Like Structures in Cocultures of Mesenchymal Stem Cells and Outgr…

2011

Mesenchymal stem cells (MSC) from bone marrow and outgrowth endothelial cells (OEC) from peripheral blood are considered as attractive cell types for applications in regenerative medicine aiming to build up complex vascularized tissue-engineered constructs. MSC provide several advantages such as the potential to differentiate to osteoblasts and to support the neovascularization process by release of proangiogenic factors. On the other hand, the neovascularization process can be actively supported by OEC forming perfused vascular structures after co-implantation with other cell types. In this study the formation of angiogenic structures in vitro was investigated in cocultures of MSC and OEC,…

Preservation of dendritic cell function upon labeling with amino functionalized polymeric nanoparticles.

2010

Dendritic cells (DCs) are key players in eliciting immunity against antigens, therefore making them the focus of many investigations on immune responses in infections, cancer and autoimmune diseases. Nanosized materials have just recently been investigated for their use as carriers of antigens and as labeling agents for DCs. For this later use nanoparticles should be non-toxic and should most importantly not alter the physiological functions of DCs. Here we demonstrate that by the use of polymeric fluorescent nanoparticles as synthesized by the miniemulsion process immature DCs (iDCs) can be efficiently labeled intracellularly. Amino functionalized nanoparticles are more effective than carb…

Functionalized Polystyrene Nanoparticles Trigger Human Dendritic Cell Maturation Resulting in Enhanced CD4+T Cell Activation

2012

Nanoparticles (NP) represent a promising tool for biomedical applications. Here, sulfonate- and phosphonate-functionalized polystyrene NP are analyzed for their interaction with human monocyte-derived dendritic cells (DC). Immature dendritic cells (iDC) display a higher time- and dose-dependent uptake of functionalized polystyrene NP compared to mature dendritic cells (mDC). Notably, NP induce an enhanced maturation of iDC but not of mDC (upregulation of stimulatory molecules and cytokines). NP-triggered maturation results in a significantly enhanced T cell stimulatory capacity (increased CD4(+) T cell proliferation and IFN-γ production), indicating a shift to a pronounced Th1 response. Imm…

Hyaluronic Acid–Silica Nanohybrid Gels

2013

Excessive water sorption and low mechanical properties are a severe drawback in some biomedical applications of hyaluronic acid (HA). A way to improve these properties is here explored through the novel concept of nanohybrid hydrogels consisting of a HA matrix including different amounts of silica-derived species. This inorganic filler phase controls the mechanical and swelling properties of HA cross-linked matrices. Below a 2 wt % of silica in the systems, nanoparticle aggregates of tens of nanometers and silica oligomers are distributed more or less homogeneously throughout the organic matrix, without percolating. This morphology of the silica phase is accompanied by an increased swelling…

Smaller calcite lattice deformation caused by occluded organic material in coccoliths than in mollusk shell.

2015

7 pages; International audience; The growth and nucleation of biominerals are directed and affected by associated biological molecules. In this paper, we investigate the influence of occluded biomolecules on biogenic calcite from the coccolithophorid Pleurochrysis carterae and from chalk, a rock composed predominantly of fossil coccoliths. We compare the results with data on chalk from the extensively studied mussel Pinna nobilis that served as a control. Using high resolution synchrotron powder X-ray diffraction combined with in situ heating, the influence of organic compounds on the structure of the inorganic phase was probed. Two heating cycles allow us to differentiate the effects of th…

2018

Synthetic materials based on calcium phosphate (CaP) are frequently used as bone graft substitutes when natural bone grafts are not available or not suitable. Chemical similarity to bone guarantees the biocompatibility of synthetic CaP materials, whereas macroporosity enables their integration into the natural bone tissue. To restore optimum mechanical performance after the grafting procedure, gradual resorption of CaP implants and simultaneous replacement by natural bone is desirable. Mg and Sr ions released from implants support osteointegration by stimulating bone formation. Furthermore, Sr ions counteract osteoporotic bone loss and reduce the probability of related fractures. The presen…