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NanoHydroxyapatite/chitosan (Cs) composite material has been successfully synthesized by the co-precipitation method. The Hydroxyapatite (HAp) was synthesized by utilizing limestone in Druju Malang, East Java, as a source of calcium using the co-precipitation method. XRD characterization resulted in HAp crystal size 23.13 nm, and EDX characterization results showed a Ca/P ratio of 1.64. Variations in the pH of the solution with values 4, 7, and 13 were carried out on the synthesis of nanoHAp/Cs composites. At pH 4 (acid) for samples with sintering showed a significant increase in hardness compared to those without sintering from 14.28 to 177.87 kg/mm2. Acid pH conditions increase the hardness of the composite significantly. Therefore, the choice of reaction pH is worth consideration. [ABSTRACT FROM AUTHOR]

This research developed a single contrast agent based on hydroxyapatite (HA) [Ca10(PO4)6(OH)2] nanoparticles with Ag+ ions substitution to improve image quality. The samples of Ca10-xAgx(PO4)6(OH)2 with Ag concentrations (0≤x≤ 0.0028) were synthesized by co-precipitation method. The results showed that Ca10-xAgx(PO4)6(OH)2 was successfully synthesized in a single phase which has hexagonal structure. The substitution of Ag+ ions cause the decrease in the crystal size. The biocompatibility of samples decreases compared to pure HA. The contrast level of the samples was confirmed by SEM. The substitution of Ag+ with concentration x=0.0024 is suitable for contrast agents. [ABSTRACT FROM AUTHOR]

This study aims to fabricate PYA/PEG/Chitosan nanofiber scaffolds for skin tissue engineering. The scaffolds in the nanofiber structure closely match with the ECM structure of the skin tissue. PYA/PEG/Chitosan nanofibers were prepared by electrospinning technique with various compositions (v/v) % (95:5, 90:10, 85:15, 80:20). The scaffold surface morphology was characterized by scanning electron microscopy (SEM), and the functional groups were characterized by Fourier transform infrared (FTIR). The biodegradation test was carried out by immersing the sample in a simulated body fluid (SBF) solution with time variations of 1, 2, 3, and 4 weeks. The scaffolds have diameters in the range of 110-520 nm, which correspond to the skin ECM, and porosity in the range of 63-71%, which facilitates cell adhesion, and proliferation. The rate of biodegradation is faster in the composition (95:5). The surface morphology with random fiber diameter, porosity, and biodegradation are suitable for skin tissue scaffolding. [ABSTRACT FROM AUTHOR]

This paper describes the microstructural properties included the average particle diameter of Co0.8Ni0.2Fe2O4 nanoparticles with Williamson-Hall (W-H) method. The Co0.8Ni0.2Fe2O4 nanoparticles have been successfully synthesized by coprecipitation technique with the various high annealing temperatures. Based on the XRD analysis, Co0.8Ni0.2Fe2O4 nanoparticles had a single phase with the spinel cubic structure. The crystallite size and lattice strain were studied by W-H method using Uniform Deformation Model (UDM). This model was in line with Scherrer's formula. The TEM results confirmed that the range of average particle sizes was about 19 – 30 nm. [ABSTRACT FROM AUTHOR]

Nowadays, bone tissue engineering is developed rapidly along with better and faster healing needs. One application of bone tissue engineering is improvement in defects. This improvement was completed by regenerating the tissue through a skeleton called scaffold. In this study, nano-Hydroxyapatite (n-HAp)/PLA scaffold composites were successfully made with variations in composition. The basic ingredients for making n-HAp are from natural materials using the sonication method. Addition of PLA into the nHAp matrix was carried out with variations of 10, 20, 30, 40 and 50 wt%. Nano-HAp was characterized using XRD and SEM. n-HAp/PLA composites were characterized by SEM and porosity tests were carried out. The results showed the crystal size of HAp was 14.46 nm. The most optimal porosity test on composites with the composition of n-HAp: PLA; 90:10 wt%. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAp) is a bioceramic that can be applied for bone tissue regeneration. The hydroxyapatite scaffold has poor biodegradation. To increase the biodegradation of HAp, we composited it with PVA, Chitosan, and PEG polymers, which have faster biodegradation properties. PVA/CS/PEG/HAp composites nanofibers as a scaffold in bone tissue engineering were prepared by electrospinning. The composition of HAp varied 0, 2, 3, 4, 5, and 6%. HAp was synthesized from natural deposits and characterized using X-Ray Diffraction (XRD) to obtain phase, crystallinity, and crystal size. Surface morphology and porosity of nanofiber composites were characterized by SEM-EDX. Previous studies without the addition of PEG produced less homogeneous nanofibers. Increasing the concentration of HAp and adding PEG could increase the average diameter of the nanofiber and reduce porosity. Composite biodegradation of PVA/CS/PEG/HAp was also evaluated. Biodegradation test was carried out by immersing the sample in Krebs solution prepared for 1-4 weeks, and the fastest mass reduction occurred in HAp (0%) and decreased with increasing concentration of HAp. This nanofiber HAp/CS/PEG/HAp composite can be applied as a scaffold in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Ceramic/polymer composites are currently being developed by researchers because of their wide applications in biomedical. This work describes the synthesis of hydroxyapatite/polyethylene glycol (nHAp/PEG) composites by the co-precipitation method with a composition ratio of 80:20 wt% and temperature variations of 25, 50, 75 °C. HAp was synthesized from limestone using the co-precipitation method. The properties of HAp and nHAp/PEG composites were evaluated using XRD, SEM, EDX and hardness that was tested by Vickers hardness. Synthetic HAp has a crystal size of 28.89 nm. The co-precipitation temperature affected the porosity and hardness of the nHAp/PEG composites, respectively for porosity of 2.98, 5.88, 8.82% and for hardness of 0.07, 0.05, 0.04 GPa. SEM results show a microstructure with a narrow grain size distribution, which means it is almost homogeneous. Hardness values in the range 0.04-0.07 GPa are appropriate for dentin applications. [ABSTRACT FROM AUTHOR]

A study on Hydroxyapatite /Polyethylene-Glycol (HAp/PEG) composite is intriguing because of its biocompatible, bioactive, non-toxic features. Thus, it is mostly applied in the biomedical field. This study describes the fabrication of HAp/PEG composite. HAp nanoparticle was synthesized using limestone from Puger, Indonesia, with co-precipitation method. HAp/PEG composite with a weight ratio of 80:20% was fabricated using precipitation method with the deposit time variation of 12, 24, and 36 hours. The properties of HAp and Hap/PEG composite were evaluated using XRD, SEM, and EDX, while their hardness characteristic was determined through the Vickers hardness machine. The synthetic HAp has a crystallite size of 33.876 nm and a Ca/P ratio of 1.68. The increase of the deposit period enhances the HAp crystallite size and reduces the PEG crystallite size within the composite. The crystallinity degree raises along with upsurges of deposit period with a range of 33.54–74.36%. The optimum hardness of the HAp/PEG composite of 71.2 HVN occurs at the deposit period of 24 hours. The lowest hardness level of 43.1 HVN happens during the deposit period of 12 hours. The surface morphology has many more pores than in the deposit period of 24 and 36 hours. Therefore, the crystallinity degree, hardness, and surface morphology of the HAp/PEG composite are affected by the deposit period. [ABSTRACT FROM AUTHOR]

The synthesis of Fe3O4@ZnS core-shell has been successfully carried out using sonochemical methods. This research was conducted to investigate the crystal structure, functional groups, morphology, and antibacterial activity of Fe3O4@ZnS core-shell by varying the concentration of the ZnS precursor. The XRD characterization results showed that the addition of the ZnS composition resulted in a diffraction peak, representing the inverse cubic spinel (Fe3O4), and cubic sphalerite (ZnS) phases. Based on XRD data analysis, the average particle size of Fe3O4 was 7 - 21 nm, while the ZnS was 3 - 6 nm. The results of FTIR characterization indicated the presence of Fe-O functional groups in the wavenumbers range of 520.24 - 647.36 cm−1 for tetrahedra and 415.83 cm-1 for octahedral, linear to the cubic structure of Fe3O4. In addition, a ZnS functional group appeared at wave number of 959.09 - 1120.25 cm−1 and zinc acetate at wave number of 1548.51 - 1575.79 cm-1. The particle size distribution resulting from SEM characterization for Fe3O4 and Fe3O4@ZnS core-shell with variations of ZnS precursor concentrations of 1x and 2x were 88.36, 105.27, and 156.55 nm, respectively. The antibacterial inhibition of Fe3O4@ZnS core-shell was quite effective in preventing bacterial growth. The diameter of the antibacterial inhibitory capacity of Fe3O4@ZnS core-shell ranged from 3.6 - 7 mm. Thus, Fe3O4@ZnS core-shell is very potential to be applied as an antibacterial agent. [ABSTRACT FROM AUTHOR]

Zinc oxide nanorods/Graphene (ZnO NRs/Gr) were synthesized using an easy and fast method; spray for ZnO seed and graphene deposition and hydrothermal for ZnO NRs. The sample was varied by using different ZnO seed precursor of 0.1 M, 0.2 M, and 0.3 M. We found that the greater the concentration of ZnO led to a decrease in porosity, accompanied by an increase in the water contact angle of 150°, 153°, and 155°. The XRD results confirmed that there was no shift in the ZnO peak, which indicated that there was no significant structural change due to the lattice strain. UV-Vis analysis obtained a band gap of ∼3.4 eV and an excited state of ∼4 eV. Based on the results obtained, ZnO NRs/Graphene can be a promising waterproof coating material on cotton fabrics. [ABSTRACT FROM AUTHOR]

Silver nanoparticle has excellent antibacterial activity. For human treatment, it is necessary to optimize the activity as well as to prepare it as a biocompatible and safe compound. In this report, we use a combination of silver nanoparticle (AgNPs) and magnetite Fe3O4 nanoparticles (MNPs) which are encapsulated using polyethylene glycol (PEG). We report detail the influence of AgNPs on crystal structure, absorbance, and antibacterial activity of Ag-Fe3O4@PEG. The structure of the system has been characterized using FT-IR to obtain its functional group's bonds, XRD to obtain its crystal structure and its grain size, and SEM to achieve its morphology. The absorbance of Ag-Fe3O4@PEG was characterized using UV-Vis, while antibacterial activity was tested using diffusion method. It was shown that the introduction of AgNPs changes the functional bonds of the system. There is no significant change in the lattice parameter value. It means that the AgNPs, MNPs, and PEG appear as a composite system. We found that the porosity qualitatively changed with the increase of AgNPs. It is obtained that the absorbance of the system is gradually reduced by the increase of AgNPs addition, except an increasing feature at 0.11 g addition of AgNPs. It was also revealed that the rise of AgNPs resulted in increasing the antibacterial activity as expected previously. [ABSTRACT FROM AUTHOR]