Apatite Glass-Ceramics: A Review

The authors would like to thank Cera Dynamics Limited, part of the James Kent Group and the Institute of Dentistry (Queen Mary University of London) for jointly funding TD

Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds

Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG) porous scaffolds have been checked in vitro and in vivo. BAG scaffolds were prepared by conventional glass melting route and subsequently, scaffolds were produced by evaporation of fugitive pore formers. After thorough physico-chemical and in vitro cell characterization, scaffolds were used for pre-clinical study. Soft and hard tissue formation in a rabbit femoral defect model after 2 and 4 months, were assessed using different tools. Histological observations showed excellent osseous tissue formation in Sr and Li + Sr scaffolds and moderate bone regeneration in Li scaffolds. Fluorochrome labeling studies showed wide regions of new bone formation in Sr and Li + Sr doped samples as compared to Li doped samples. SEM revealed abundant collagenous network and minimal or no interfacial gap between bone and implant in Sr and Li + Sr doped samples compared to Li doped samples. Micro CT of Li + Sr samples showed highest degree of peripheral cancellous tissue formation on periphery and cortical tissues inside implanted samples and vascularity among four compositions. Our findings suggest that addition of Sr and/or Li alters physico-chemical properties of BAG and promotes early stage in vivo osseointegration and bone remodeling that may offer new insight in bone tissue engineering

MiniMIST- En modellsatellit för att lära ut STEM-färdigheter

Satellites are evolving around the globe, expanding our possibility to explore space and many other applications. This thesis project is a model satellite used for teaching purposes in the course IE120V Electronics and Programming for Space Applications provided at KTH Royal Institute of Technology. The model can be used to teach Science, technology, engineering, and mathematics (STEM) in high school. The satellite is inspired by the MIniature Student saTellite (MIST) project carried out by the KTH Royal Institute of Technology, and hence this project will be called ”MiniMIST.” The MiniMIST aims to perform functions carried out on practical satellites. The onboard computer performs real-time image capturing, reads temperature from the surroundings, and analyzes power from solar panels and the power supply (batteries). The ground station setup is used to communicate with the satellite (MiniMIST) and receive data to be viewed and analyzed. The ESP32-Wrover was used as the main computer to run the MiniMIST. It was programmed with MicroPython and C++. Client-server communication using HTTP protocol emulated the communication between the ground station and MiniMIST with Web-Server communication. The ground station is a web page programmed using HTML, CSS, and JavaScript along with the AJAX framework. The thesis aims to build a working prototype of MiniMIST by dividing it into three sections: Hardware design, onboard computer software, and ground station software.Satelliter utvecklas runt om i världen, vilket utökar vår möjlighet att utforska rymden och många andra applikationer. Detta examensarbete är en modellsatellit som används för undervisningsändamål i kursen IE120V Elektronik och programmering för rymdtillämpningar som ges vid Kungliga Tekniska Högskolan. Modellen kan användas för att lära ut naturvetenskap, teknik, ingenjörskap och matematik (STEM) på gymnasiet. Satelliten är inspirerad av projektet MIniature Student saTellite (MIST) som genomförts av Kungliga Tekniska Högskolan, och därför kommer detta projekt att kallas ”MiniMIST”. MiniMIST syftar till att utföra funktioner som utförs på praktiska satelliter. Datorn ombord utför bildtagning i realtid, läser av temperatur från omgivningen och analyserar ström från solpaneler och strömförsörjningen (batterier). Markstationsinställningen används för att kommunicera med satelliten (MiniMIST) och ta emot data som ska ses och analyseras. ESP32-Wrover användes som huvuddator för att köra MiniMIST. Den programmerades med MicroPython och C++. Klient-serverkommunikation med hjälp av HTTP-protokoll emulerade kommunikationen mellan markstationen och MiniMIST med webbserverkommunikation. Markstationen är en webbsida programmerad med HTML, CSS och JavaScript tillsammans med AJAX-ramverket. Avhandlingen syftar till att bygga en fungerande prototyp av MiniMIST genom att dela upp den i tre sektioner: Hårdvarudesign, inbyggd datormjukvara och markstationsmjukvara

MiniMIST- En modellsatellit för att lära ut STEM-färdigheter

Satellites are evolving around the globe, expanding our possibility to explore space and many other applications. This thesis project is a model satellite used for teaching purposes in the course IE120V Electronics and Programming for Space Applications provided at KTH Royal Institute of Technology. The model can be used to teach Science, technology, engineering, and mathematics (STEM) in high school. The satellite is inspired by the MIniature Student saTellite (MIST) project carried out by the KTH Royal Institute of Technology, and hence this project will be called ”MiniMIST.” The MiniMIST aims to perform functions carried out on practical satellites. The onboard computer performs real-time image capturing, reads temperature from the surroundings, and analyzes power from solar panels and the power supply (batteries). The ground station setup is used to communicate with the satellite (MiniMIST) and receive data to be viewed and analyzed. The ESP32-Wrover was used as the main computer to run the MiniMIST. It was programmed with MicroPython and C++. Client-server communication using HTTP protocol emulated the communication between the ground station and MiniMIST with Web-Server communication. The ground station is a web page programmed using HTML, CSS, and JavaScript along with the AJAX framework. The thesis aims to build a working prototype of MiniMIST by dividing it into three sections: Hardware design, onboard computer software, and ground station software.Satelliter utvecklas runt om i världen, vilket utökar vår möjlighet att utforska rymden och många andra applikationer. Detta examensarbete är en modellsatellit som används för undervisningsändamål i kursen IE120V Elektronik och programmering för rymdtillämpningar som ges vid Kungliga Tekniska Högskolan. Modellen kan användas för att lära ut naturvetenskap, teknik, ingenjörskap och matematik (STEM) på gymnasiet. Satelliten är inspirerad av projektet MIniature Student saTellite (MIST) som genomförts av Kungliga Tekniska Högskolan, och därför kommer detta projekt att kallas ”MiniMIST”. MiniMIST syftar till att utföra funktioner som utförs på praktiska satelliter. Datorn ombord utför bildtagning i realtid, läser av temperatur från omgivningen och analyserar ström från solpaneler och strömförsörjningen (batterier). Markstationsinställningen används för att kommunicera med satelliten (MiniMIST) och ta emot data som ska ses och analyseras. ESP32-Wrover användes som huvuddator för att köra MiniMIST. Den programmerades med MicroPython och C++. Klient-serverkommunikation med hjälp av HTTP-protokoll emulerade kommunikationen mellan markstationen och MiniMIST med webbserverkommunikation. Markstationen är en webbsida programmerad med HTML, CSS och JavaScript tillsammans med AJAX-ramverket. Avhandlingen syftar till att bygga en fungerande prototyp av MiniMIST genom att dela upp den i tre sektioner: Hårdvarudesign, inbyggd datormjukvara och markstationsmjukvara

Standardization of growing media for hardening plantlets of Dendrobium var. Thongchai Gold

An experiment was conducted at Horticultural Research Station, Pechiparai, Tamil Nadu Agricultural University during the year 2017-2018 to standardize the media for hardening the plantlets of Dendrobium var. Thongchai Gold. The in vitro plantlets were hardened with four different growing media and their combinations viz., charcoal, coconut husk, broken pot pieces, thermocol and their combinations as  charcoal + coconut husk (1:1) ,  charcoal + broken pot pieces (1:1), charcoal + thermocol (1:1), coconut husk + broken pot pieces (1:1), coconut  husk + thermocol (1:1), charcoal + coconut husk + broken pot pieces (1:1:1) and charcoal + coconut husk + broken pot pieces + thermocol (1:1:1:1). The results revealed that combination of coconut husk and broken pot pieces in 1:1 ratio significantly enhanced the plant height (9.02 cm) and number of leaves per plantlet (4.61) while the control recorded the plant height of (7.47 cm) with 3.50 leaves per plant. The leaf length (6.96 cm), root length (6.90 cm) and shoot girth (3.20 mm) were the highest in the treatment combination of coconut husk and broken pot pieces in 1:1 ratio.  In the control the leaf length (5.52 cm), root length (5.30 cm) and shoot girth (2.20 mm) respectively. The highest survival per cent of 83.49 was recorded in the same treatment where as the survival per cent in the control was 62.55. Hence it can be concluded that the treatment combination of coconut husk and broken pot pieces in 1:1 ratio was the best medium for hardening the in vitro plantlets of Dendrobium var. Thongchai Gold

Determination of Oxidative Stress Related Toxicity on Repeated Dermal Exposure of Hydroxyapatite Nanoparticles in Rats

Hydroxyapatite nanoparticles (HANPs) have numerous applications, such as substitute for bone grafting, bone fillers, bioceramic coating, and dental fillings. The toxicity of these nanomaterials is of growing concern despite their significant scientific interest and promising potential in many applications. In this study, an in-house synthesized, characterized HANP of size <50 nm was investigated for the dermal toxicity. A paste of HANPs was prepared in water and applied on the dorsal side of the rats for 28 days. At the end of 28 days, blood was subjected to haematological and biochemical analysis. Gross necropsy was conducted and major organs were collected for histopathological observations. Liver from the animals was evaluated for lipid peroxidation, reduced glutathione, and antioxidant enzymes activity. It was observed that none of the animals showed any abnormality during the experimental period. Gross examination of carcasses did not reveal any abnormality in the organs examined. The results also demonstrated that there was no significant fluctuation in the level of antioxidant defense mechanisms, lipid peroxidation, and haematological and biochemical parameters. There was no histopathological lesion observed in any of the organs. Hence, it can be concluded that the synthesized HANPs were nontoxic at cellular level, when exposed dermally to rats

Biocompatibility property of 100% strontium-substituted SiO2-Al2O3-P2O5-CaO-CaF2 glass ceramics over 26 weeks implantation in rabbit model: Histology and micro-Computed Tomography analysis

One of the desired properties for any new biomaterial composition is its long-term stability in a suitable animal model and such property cannot be appropriately assessed by performing short-term implantation studies. While hydroxyapatite (HA) or bioglass coated metallic biomaterials are being investigated for in vivo biocompatibility properties, such study is not extensively being pursued for bulk glass ceramics. In view of their inherent brittle nature, the implant stability as well as impact of long-term release of metallic ions on bone regeneration have been a major concern. In this perspective, the present article reports the results of the in vivo implantation experiments carried out using 100% strontium (Sr)-substituted glass ceramics with the nominal composition of 4.5 SiO2-3Al(2)O(3)-1.5P(2)O(5)-3SrO-2SrF(2) for 26 weeks in cylindrical bone defects in rabbit model. The combination of histological and micro-computed tomography analysis provided a qualitative and quantitative understanding of the bone regeneration around the glass ceramic implants in comparison to the highly bioactive HA bioglass implants (control). The sequential polychrome labeling of bone during in vivo osseointegration using three fluorochromes followed by fluorescence microscopy observation confirmed homogeneous bone formation around the test implants. The results of the present study unequivocally confirm the long-term implant stability as well as osteoconductive property of 100% Sr-substituted glass ceramics, which is comparable to that of a known bioactive implant, that is, HA-based bioglass. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1168-1179, 2015