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Design of a scaffold with convenient mechanical properties to emulate bone structure is a major challenge for bone tissue engineers. In this study, porous ceramic scaffolds containing various weigh...

© 2017, Australian Ceramic Society. Nanofibrous composites of the poly(ε-caprolactone) (PCL), tricalcium phosphate (TCP), and hexagonal boron nitride (h-BN) with different compositions were manufactured by using an economical and non-complicated method called electrospinning. Produced fibrous structures showed no bead formation and had a clean surface. Characterization of the composites showed that particles were successfully mixed with polymer phase. High cell activity of SaOS-2 cells on the composites was observed with SEM images. In addition, fibrous scaffolds are biocompatible with human bone tissue and are highly degradable.

β-Tri calcium phosphate ceramics play a significant role in several biomedical application for their marked resorbability and bioactivity. One of them is in bone grafting, where it is used for treating bone defects caused by wounds or osteoporosis. In the present work an in-depth and systematic study of pure and different doped variants (Zinc, Magnesium and Titanium) of β-Tri calcium phosphate was done. We have prepared pure β-Tri calcium phosphate and its different dopants of different strength. All together seven different composition were studied. We have tried to investigate some important features which are the prerequisite for their application. These include lattice parameter study, mechanical properties, contacts behaviour with SBF, haemolytic characteristics, and its cytotoxic nature. The capability of new apatite development on the surface of pure and doped β-TCP samples were also considered and compared by using Simulated Body Fluid (SBF) to observe their interaction with human body fluid.

Calcium sulfate/tri-calcium phosphate (CaSO4/TCP) composite bone fillers were fabricated through molding method. Their structure and properties were characterized by infrared spectroscope, scanning electronic spectroscope, x-ray diffraction and degradation test. The results show that TCP crystals were attached to the CaSO4 crystals and prevented the growing of sulfate crystals. So their size is shorter than that of CaSO4 crystals prepared from pure CaSO4 semihydrate, and some even had defect. The resorption rate of CaSO4 bone fillers was decreased when TCP was incorporated.

Scaffold-like hydroxyapatite/tri-calcium-phosphate (HA/TCP) coatings have been deposited on strong zirconia-substrates using a unique HA-slip coating-deposition and coating-substrate co-sintering process. Bending strength of such layered composites is over 300 MPa, higher than the upper strength limit of natural bones. Thick scaffold-like HA-coatings with open pores larger than 100 lm can be deposited onto the micro-porous HA/TCP surface using the same technique. Such load-bearing “HA-scaffolds” with adequate bending strength and large open pore structures provide useful options as loadbearing bone implants.

Background: Angiogenesis is crucial for the success of bone reconstruction through tissue engineering. Currently, is still not known the activity of endothelial cells that is responsible for blood vessel formation, cultured in HA/TCP/chitosan scaffold. The ability of the scaffold to facilitate the proliferation and migration of endothelial cell to form blood vessel is essential for cell survival especially in the inner area of the scaffold that is susceptible for cell death if adequate vascularization is not occurred. Purpose: The purpose of this study was to evaluate the porosity of HA/TCP/chitosan scaffold and the biocompatibility of HA/TCP/chitosan scaffold to endothelial cells. Methods: Endothelial cells were isolated from umbilical vein (human umbilical vein endothelial cells/ HUVEC). HA/ TCP/chitosan scaffold was made from two gelling agents and various basic washing solutions. The characteristic of scaffold was examined by scanning electron microscopy. The activity of HUVEC was evaluated by MTT assay. Results: Initial average scaffold porosity size range from 68 μm and increased up to 134 μm after 7 days incubation with 10 mg/L lysozyme. There was no significant difference in the viability of HUVEC incubated with the scaffold compared to control. Conclusion: HA/TCP/chitosan has a good biocompatibility for HUVEC. This condition supports the activity of HUVEC in the scaffold for angiogenesis process, to provide oxygen and nutrient necessary for osteoblast.Latar belakang: Angiogenesis merupakan proses yang penting untuk keberhasilan rekonstruksi tulang melalui rekayasa jaringan. Saat ini, aktifitas sel endotel pembentuk dinding pembuluh darah pada HA/TCP/chitosan scaffold belum diketahui. Kemampuan scaffold sebagai tempat proliferasi dan migrasi sel endotel untuk membentuk pembuluh darah penting untuk kelangsungan hidup sel osteoblast terutama di bagian dalam scaffold. Tujuan: Mengevaluasi porositas HA/TCP/chitosan scaffold serta sifat biokompatibilitas scaffold terhadap sel endotel. Metode: Sel endotel diisolasi dari vena tali pusat (human umbilical vein endothelial cells/HUVEC). HA/TCP/ chitosan scaffold dibuat dengan variasi gelling agents dan dicuci dengan berbagai larutan basa. Karakter scaffold dievaluasi dengan scanning electron microscope. Aktifitas HUVEC dievaluasi dengan MTT assay. Hasil: Pada tahap awal, rata-rata ukuran porus 68 μm dan meningkat menjadi 134 μm setelah inkubasi dengan 10 mg/mL lysosyme selama 7 hari. Kultur HUVEC pada scaffold selama 24 jam tidak menunjukkan tingkat viabilitas yang berbeda dibandingkan dengan kontrol. Kesimpulan: HA/TCP/chitosan memiliki sifat biokompatibilitas yang baik terhadap sel HUVEC. Kondisi ini memberikan dukungan terhadap aktifitas sel HUVEC pada scaffold untuk proses angiogenesis yang akan memberikan oksigen dan nutrisi untuk osteoblas.

Porous tri-calcium phosphate, well-known for its use as artificial bone, was prepared via sponge polymeric method by the application of low cost polyurethane (PU) foam as a structural guide. In this experiment, fractions of tri-calcium phosphate (TCP) are controlled at 12, 13, 14, 15 and 16 grams and mixed with distilled water (fixed at 25 grams) to produce slurries. Subsequently, rectangular shaped PU foam was immersed in the slurry and dried for three days. Samples were then sintered at 1100°C to obtain porous tri-calcium phosphate. This method produces porous tri-calcium phosphate with porosity between 31-44% and the compressive strength in the range of 0.17-1.02 MPa. The macroporosity of the tri-calcium phosphate, observed through SEM, was in the range of 100 µm to 900 µm.

The tissue engineering focuses on synthesis or regeneration of tissues and organs. The hierarchical structure of nearly all porous scaffolds on the macro, micro- and nanometer scales resembles that of engineering foams dedicated for technical applications, but differ from the complex architecture of long bone. A major obstacle of scaffold architecture in tissue regeneration is the limited cell infiltration as the result of the engineering approaches. The biological cells seeded on the three-dimensional constructs are finally only located on the scaffold's periphery. This paper reports on the successful realization of calcium phosphate scaffolds with an anatomical architecture similar to long bones. Two base materials, namely nano-porous spray-dried hydroxyapatite hollow spheres and tri-calcium phosphate powder, were used to manufacture cylindrically shaped, 3D-printed scaffolds with micro-passages and one central macro-canal following the general architecture of long bones. The macro-canal is built for the surgical placement of nerves or larger blood vessels. The micro-passages allow for cell migration and capillary formation through the entire scaffold. Finally, the nanoporosity is essential for the molecule transport crucial for signaling, any cell nutrition and waste removal.

Tricalcium Phosphate Anhydrous Powder typically contains 300 to 400 mg/Kg (w/w) of aluminum. This level can be determined utilizing AAS and standard based on known standards. In this study, we have determined the amount of aluminum metal present in sample of Tricalcium Phosphate Anhydrous Powder using Atomic Absorption Spectrophotometer (AAS). The method has high precision and accuracy. The results of aluminum determinations obtained by employment of N2O-C2H2 flame AAS methods. Great care is necessary for preparation of the blank. The need to subtract blank with standard calibration curve this was done automatically. The accuracy was checked with recovery test of aluminum added to the sample before analysis. With employment of AAS method 98.5% and 99.0% of added aluminum was recovered. The detection limit for the determination of Al was 0.5 mg/Kg and results meet the requirements.

This work was focused to study the existence of Zn 2+ in structure, chemical composition as well as particle and crystallite size of hydroxyapatite (HAp) to characterize the effect of pH of the solution and calcination temperature. Non-stoichiometric HAp (nHAp) powders containing 4 at.% zinc fraction were synthesized via solution–precipitation method. In order to characterize the effect of pH (values: 9 and 10.5) and two calcination temperatures (550 and 1000 °C) on chemical composition, molecule internal bonds, particle and crystallite size of the synthesized powders, XRD, EDS, FTIR and SEM techniques were utilized. The results showed that zinc cations could be incorporated in the HAp atomic structure to form low crystalline single phase of nHAP. The pH adjustment to 10.5 caused the formation of powders with smaller particle and crystallite sizes. The results also indicated that calcination temperature up to 1000 °C caused decomposition of zinc doped nHAp to β-tri calcium phosphate and tri zinc calcium phosphate phases which are used to control the speed of biodegradation.