Influence of additives and binder on the physical properties of dental silicate glass-ceramic feedstock for additive manufacturing.

Objectives: The aim of the study was to investigate the impact of organic additives (binder, plasticizer, and the cross-linking ink) in the formulation of water-based feedstocks on the properties of a dental feldspathic glass-ceramic material developed for the slurry-based additive manufacturing technology "LSD-print."

Material And Methods: Three water-based feldspathic feedstocks were produced to study the effects of polyvinyl alcohol (AC1) and poly (sodium 4-styrenesulfonate) (AC2) as binder systems. A feedstock without organic additives was tested as the control group (CG).

Material aspects of sintering of EAC-1A lunar regolith simulant.

Future lunar exploration will be based on in-situ resource utilization (ISRU) techniques. The most abundant raw material on the Moon is lunar regolith, which, however, is very scarce on Earth, making the study of simulants a necessity. The objective of this study is to characterize and investigate the sintering behavior of EAC-1A lunar regolith simulant.

Osteogenic Effect of a Bioactive Calcium Alkali Phosphate Bone Substitute in Humans.

(1) Background: The desire to avoid autograft harvesting in implant dentistry has prompted an ever-increasing quest for bioceramic bone substitutes, which stimulate osteogenesis while resorbing in a timely fashion. Consequently, a highly bioactive silicon containing calcium alkali orthophosphate (Si-CAP) material was created, which previously was shown to induce greater bone cell maturation and bone neo-formation than β-tricalcium phosphate (β-TCP) in vivo as well as in vitro. Our study tested the hypothesis that the enhanced effect on bone cell function in vitro and in sheep in vivo would lead to more copious bone neoformation in patients following sinus floor augmentation (SFA) employing Si-CAP when compared to β-TCP.

Laser melting manufacturing of large elements of lunar regolith simulant for paving on the Moon.

The next steps for the expansion of the human presence in the solar system will be taken on the Moon. However, due to the low lunar gravity, the suspended dust generated when lunar rovers move across the lunar soil is a significant risk for lunar missions as it can affect the systems of the exploration vehicles. One solution to mitigate this problem is the construction of roads and landing pads on the Moon.

Additive manufacturing of metallic glass from powder in space.

Additive manufacturing of metals - and in particular building with laser-based powder bed fusion - is highly flexible and allows high-resolution features and feedstock savings. Meanwhile, though space stations in low Earth orbit are established, a set of visits to the Moon have been performed, and humankind can send out rovers to explore Venus and Mars, none of these milestone missions is equipped with technology to manufacture functional metallic parts or tools in space. In order to advance space exploration to long-term missions beyond low Earth orbit, it will be crucial to develop and employ technology for in-space manufacturing (ISM) and in-situ resource utilisation (ISRU).

A tissue engineered 3D printed calcium alkali phosphate bioceramic bone graft enables vascularization and regeneration of critical-size discontinuity bony defects .

Recently, efforts towards the development of patient-specific 3D printed scaffolds for bone tissue engineering from bioactive ceramics have continuously intensified. For reconstruction of segmental defects after subtotal mandibulectomy a suitable tissue engineered bioceramic bone graft needs to be endowed with homogenously distributed osteoblasts in order to mimic the advantageous features of vascularized autologous fibula grafts, which represent the standard of care, contain osteogenic cells and are transplanted with the respective blood vessel. Consequently, inducing vascularization early on is pivotal for bone tissue engineering.

Entering a New Dimension in Powder Processing for Advanced Ceramics Shaping.

Filigree structures can be manufactured via two-photon polymerization (2PP) operating in the regime of nonlinear light absorption. For the first time, it is possible to apply this technique to the powder processing of ceramic structures with a feature size in the range of the critical defect sizes responsible for brittle fracture and, thus, affecting fracture toughness of high-performance ceramics. In this way, tailoring of advanced properties can be achieved already in the shaping process.

Powder 3D Printing of Bone Scaffolds with Uniform and Gradient Pore Sizes Using Cuttlebone-Derived Calcium Phosphate and Glass-Ceramic.

The pore geometry of bone scaffolds has a major impact on their cellular response; for this reason, 3D printing is an attractive technology for bone tissue engineering, as it allows for the full control and design of the porosity. Calcium phosphate materials synthesized from natural sources have recently attracted a certain interest because of their similarity to natural bone, and they were found to show better bioactivity than synthetic compounds. Nevertheless, these materials are very challenging to be processed by 3D printing due to technological issues related to their nanometric size.

Searching for biological feedstock material: 3D printing of wood particles from house borer and drywood termite frass.

Frass (fine powdery refuse or fragile perforated wood produced by the activity of boring insects) of larvae of the European house borer (EHB) and of drywood termites was tested as a natural and novel feedstock for 3D-printing of wood-based materials. Small particles produced by the drywood termite Incisitermes marginipennis and the EHB Hylotrupes bajulus during feeding in construction timber, were used. Frass is a powdery material of particularly consistent quality that is essentially biologically processed wood mixed with debris of wood and faeces.

Development of biodegradable bioactive glass ceramics by DLP printed containing EPCs/BMSCs for bone tissue engineering of rabbit mandible defects.

Bioactive glass ceramics have excellent biocompatibility and osteoconductivity; and can form direct chemical bonds with human bones; thus, these ceramic are considered as "Smart" materials. In this study, we develop a new type of bioactive glass ceramic (AP40mod) as a scaffold containing Endothelial progenitor cells (EPCs) and Mesenchymal stem cells (BMSCs) to repair critical-sized bone defects in rabbit mandibles. For in vitro experiments: AP40mod was prepared by Dgital light processing (DLP) system and the optimal ratio of EPCs/BMSCs was screened by analyzing cell proliferation and ALP activity, as well as the influence of genes related to osteogenesis and angiogenesis by direct inoculation into scaffolds.

The GDF5 mutant BB-1 enhances the bone formation induced by an injectable, poly(l-lactide-co-glycolide) acid (PLGA) fiber-reinforced, brushite-forming cement in a sheep defect model of lumbar osteopenia.

Background Context: Targeted delivery of osteoinductive bone morphogenetic proteins (eg, GDF5) in bioresorbable calcium phosphate cement (CPC), potentially suitable for vertebroplasty and kyphoplasty of osteoporotic vertebral fractures, may be required to counteract augmented local bone catabolism and to support complete bone regeneration. The biologically optimized GDF5 mutant BB-1 may represent an attractive drug candidate for this purpose.

Purpose: The aim of the current study was to test an injectable, poly(l-lactide-co-glycolide) acid (PLGA) fiber-reinforced, brushite-forming CPC containing low-dose BB-1 in a sheep lumbar osteopenia model.

GDF5 significantly augments the bone formation induced by an injectable, PLGA fiber-reinforced, brushite-forming cement in a sheep defect model of lumbar osteopenia.

Background Context: Biodegradable calcium phosphate cement (CPC) represents a promising option for the surgical treatment of osteoporotic vertebral fractures. Because of augmented local bone catabolism, however, additional targeted delivery of bone morphogenetic proteins with the CPC may be needed to promote rapid and complete bone regeneration.

Purpose: In the present study, an injectable, poly(l-lactide-co-glycolide) acid (PLGA) fiber-reinforced, brushite-forming cement (CPC) containing the bone morphogenetic protein GDF5 was tested in a sheep lumbar osteopenia model.

Low-dose BMP-2 is sufficient to enhance the bone formation induced by an injectable, PLGA fiber-reinforced, brushite-forming cement in a sheep defect model of lumbar osteopenia.

Background Context: Bioresorbable calcium phosphate cement (CPC) may be suitable for vertebroplasty/kyphoplasty of osteoporotic vertebral fractures. However, additional targeted delivery of osteoinductive bone morphogenetic proteins (BMPs) in the CPC may be required to counteract the augmented local bone catabolism and support complete bone regeneration.

Purpose: This study aimed at testing an injectable, poly (l-lactide-co-glycolide) acid (PLGA) fiber-reinforced, brushite-forming cement (CPC) containing low-dose bone morphogenetic protein BMP-2 in a sheep lumbar osteopenia model.

Enhanced bone formation in sheep vertebral bodies after minimally invasive treatment with a novel, PLGA fiber-reinforced brushite cement.

Background Context: Injectable, brushite-forming calcium phosphate cements (CPC) show potential for bone replacement, but they exhibit low mechanical strength. This study tested a CPC reinforced with poly(l-lactide-co-glycolide) acid (PLGA) fibers in a minimally invasive, sheep lumbar vertebroplasty model.

Purpose: The study aimed to test the in vivo biocompatibility and osteogenic potential of a PLGA fiber-reinforced, brushite-forming CPC in a sheep large animal model.

Development of a synthetic tissue engineered three-dimensional printed bioceramic-based bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro.

Over the last decade there have been increasing efforts to develop three-dimensional (3D) scaffolds for bone tissue engineering from bioactive ceramics with 3D printing emerging as a promising technology. The overall objective of the present study was to generate a tissue engineered synthetic bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro, thereby mimicking the advantageous properties of autogenous bone grafts and facilitating usage for reconstructing segmental discontinuity defects in vivo. To this end, 3D scaffolds were developed from a silica-containing calcium alkali orthophosphate, using, first, a replica technique - the Schwartzwalder-Somers method - and, second, 3D printing, (i.

Decreased extrusion of calcium phosphate cement versus high viscosity PMMA cement into spongious bone marrow-an ex vivo and in vivo study in sheep vertebrae.

Background Context: Vertebroplasty or kyphoplasty of osteoporotic vertebral fractures bears the risk of pulmonary cement embolism (3.5%-23%) caused by leakage of commonly applied acrylic polymethylmethacrylate (PMMA) cement to spongious bone marrow or outside of the vertebrae. Ultraviscous cement and specific augmentation systems have been developed to reduce such adverse effects.

First-time systematic postoperative clinical assessment of a minimally invasive approach for lumbar ventrolateral vertebroplasty in the large animal model sheep.

Background Context: Large animal models are highly recommended for meaningful preclinical studies, including the optimization of cement augmentation for vertebral body defects by vertebroplasty/kyphoplasty.

Purpose: The aim of this study was to perform a systematic characterization of a strictly minimally invasive in vivo large animal model for lumbar ventrolateral vertebroplasty.

Study Design/ Setting: This is a prospective experimental animal study.

Temperature-programed time-of-flight secondary ion mass spectrometry study of 1-butyl-3-methylimidazolium trifluoromethanesulfonate during glass-liquid transition, crystallization, melting, and solvation.

For this study, time-of-flight secondary ion mass spectrometry was used to analyze the molecular orientation of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim][OTf]) and its interaction with the adsorbed Na and LiI species at temperatures of 150-300 K. A glassy [bmim][OTf] film crystallizes at around 230 K, as observed from the increase in the [bmim](+) yield. LiI and Na adsorbed on the glassy film are solvated, whereas they tend to form islands on a crystalline film.

On the wettability of lipid DPPC films.

By employing temperature-programmed desorption and time-of-flight secondary ion mass spectroscopy, the adsorption of water on the hydrophilic and hydrophobic surfaces of a lipid (DPPC) film has been investigated. It could be shown that it is possible to prepare lipid films ex situ with a preferential orientation of the lipid molecules on a solid support and to retain their specific properties under ultrahigh vacuum conditions. The water adsorption and desorption kinetics on the hydrophilic and hydrophobic surfaces provided by a lipid film are discussed in terms of their structural and chemical properties.

Sodium interacting with amorphous water films at 10 and 100 k.

In the present study, we compare the adsorption of Na on amorphous D(2)O ice films, held at 10 and 100 K. OH, D(2)O, and Na are easily distinguished by their characteristic signatures in metastable impact electron spectroscopy (MIES). It is found that at 10 K substrate temperature the donation of 3sNa charge to the ice film, which is regarded as a precursor for water deprotonation, is significantly reduced relative to 100 K.