Artificial inorganic biohybrids: The functional combination of microorganisms and cells with inorganic materials.

Unlabelled: Biohybrids can be defined as the functional combination of proteins, viable cells or microorganisms with non-biological materials. This article reviews recent findings on the encapsulation of microorganisms and eukaryotic cells in inorganic matrices such as silica gels or cements. The entrapment of biological entities into a support material is of great benefit for processing since the encapsulation matrix protects sensitive cells from shear forces, unfavourable pH changes, or cytotoxic solvents, avoids culture-washout, and simplifies the separation of formed products.

Bone regeneration capacity of magnesium phosphate cements in a large animal model.

Unlabelled: Magnesium phosphate minerals have captured increasing attention during the past years as suitable alternatives for calcium phosphate bone replacement materials. Here, we investigated the degradation and bone regeneration capacity of experimental struvite (MgNHPO·6HO) forming magnesium phosphate cements in two different orthotopic ovine implantation models. Cements formed at powder to liquid ratios (PLR) of 2.

Trivalent chromium incorporated in a crystalline calcium phosphate matrix accelerates materials degradation and bone formation in vivo.

Unlabelled: Remodeling of calcium phosphate bone cements is a crucial prerequisite for their application in the treatment of large bone defects. In the present study trivalent chromium ions were incorporated into a brushite forming calcium phosphate cement in two concentrations (10 and 50 mmol/mol β-tricalcium phosphate) and implanted into a femoral defect in rats for 3 and 6 month, non-modified brushite was used as reference. Based on our previous in vitro findings indicating both an enhanced osteoclastic activity and cytocompatibility towards osteoprogenitor cells we hypothesized a higher in vivo remodeling rate of the Cr doped cements compared to the reference.

Osteoclastic differentiation and resorption is modulated by bioactive metal ions Co2+, Cu2+ and Cr3+ incorporated into calcium phosphate bone cements.

Biologically active metal ions in low doses have the potential to accelerate bone defect healing. For successful remodelling the interaction of bone graft materials with both bone-forming osteoblasts and bone resorbing osteoclasts is crucial. In the present study brushite forming calcium phosphate cements (CPC) were doped with Co2+, Cu2+ and Cr3+ and the influence of these materials on osteoclast differentiation and activity was examined.

Intrinsic 3D Prestressing: A New Route for Increasing Strength and Improving Toughness of Hybrid Inorganic Biocements.

Cement is the most consumed resource and is the most widely used material globally. The ability to extrinsically prestress cementitious materials with tendons usually made from steel allows the creation of high-strength bridges and floors from this otherwise brittle material. Here, a dual setting cement system based on the combination of hydraulic cement powder with an aqueous silk fibroin solution that intrinsically generates a 3D prestressing during setting, dramatically toughening the cement to the point it can be cut with scissors, is reported.

Data on TOF-SIMS analysis of Cu, Co and Cr doped calcium phosphate cements.

This article contains data of time of flight secondary ion mass spectrometry (TOF-SIMS) analysis of brushite-forming calcium phosphate cements doped with biologically active metal ions. This data are related to the research article "Cu, Co and Cr doping of a calcium phosphate cement influences materials properties and response of human mesenchymal stromal cells" (Schamel et al., 2017) [1].

In vitro ion adsorption and cytocompatibility of dicalcium phosphate ceramics.

Background: cell testing of degradable bioceramics such as brushite or monetite is often challenging due to the ion release into or adsorption from the culture medium. These ionic changes are then mostly responsible for cell proliferation and activity, which prohibits the investigation of effects originating from surface topography or further material modifications.

Methods: Here, we aimed to solve this problem by developing a pre-conditioning regime following the repeated immersion of brushite and monetite samples in various Ca, Mg and PO containing electrolytes, followed by studying ion adsorption / release as well as changes in phase composition and in vitro cytocompatibility with MG63 cells.

Simultaneous formation and mineralization of star-P(EO-stat-PO) hydrogels.

Natural bone is an organic-inorganic composite of highly ordered collagen fibrils and ~60-70% nanocrystalline hydroxyapatite (HA) crystals resulting in a high fracture resistance for various mechanical loading situations. This study aimed to synthesize highly mineralized hydrogels to mimic the mechanical properties of cancellous bone. A six armed star molecule functionalized with isocyanate groups as reactive termini (NCO-sP(EO-stat-PO)) was used to build up a hydrogel matrix, which was then subsequently mineralized with hydroxyapatite nanocrystals following the hydrolysis of incorporated α-tricalcium phosphate particles.

Phytic acid as alternative setting retarder enhanced biological performance of dicalcium phosphate cement in vitro.

Dicalcium phosphate cement preparation requires the addition of setting retarders to meet clinical requirements regarding handling time and processability. Previous studies have focused on the influence of different setting modifiers on material properties such as mechanical performance or injectability, while ignoring their influence on biological cement properties as they are used in low concentrations in the cement pastes and the occurrence of most compounds in human tissues. Here, analyses of both material and biological behavior were carried out on samples with common setting retardants (citric acid, sodium pyrophosphate, sulfuric acid) and novel (phytic acid).

Cu, Co and Cr doping of a calcium phosphate cement influences materials properties and response of human mesenchymal stromal cells.

The application of biologically active metal ions to stimulate cellular reactions is a promising strategy to accelerate bone defect healing. Brushite-forming calcium phosphate cements were modified with low doses of Cu, Co and Cr. The modified cements released the metal ions in vitro in concentrations which were shown to be non-toxic for cells.

A Bone Glue with Sustained Adhesion under Wet Conditions.

Bone glues often suffer from low adhesion to bone under wet conditions. This study aims to improve wet adhesiveness of a bone glue based on a photocurable poly(ethylene glycol) dimethacrylate matrix through in situ interpenetrating network formation by addition of six-armed isocyanate functional star-shaped prepolymers (NCO-sP(EO-stat-PO)). Biodegradable ceramic fillers are added to adjust the paste workability.

Thiol-ene Clickable Poly(glycidol) Hydrogels for Biofabrication.

In this study we introduce linear poly(glycidol) (PG), a structural analog of poly(ethylene glycol) bearing side chains at each repeating unit, as polymer basis for bioink development. We prepare allyl- and thiol-functional linear PG that can rapidly be polymerized to a three-dimensionally cross-linked hydrogel network via UV mediated thiol-ene click reaction. Influence of polymer concentration and UV irradiation on mechanical properties and swelling behavior was examined.

Novel bone wax based on poly(ethylene glycol)-calcium phosphate cement mixtures.

Unlabelled: Classic bone wax is associated with drawbacks such as the risk of infection, inflammation and hindered osteogenesis. Here, we developed a novel self-setting bone wax on the basis of hydrophilic poly(ethylene glycol) (PEG) and hydroxyapatite (HA) forming calcium phosphate cement (CPC), to overcome the problems that are linked to the use of conventional beeswax systems. Amounts of up to 10 wt.