On the Ion Implantation Synthesis of Ag-Embedded Over Sr-Substituted Hydroxyapatite on a Nano-Topography Patterned Ti for Application in Acetabular Fracture Sites.

Introduction: There is an ongoing need for improved healing response and expedited osseointegration on the Ti implants in acetabular fracture sites. To achieve adequate bonding and mechanical stability between the implant surface and the acetabular fracture, a new coating technology must be developed to promote bone integration and prevent bacterial growth. Methods: A cylindrical Ti substrate mounted on a rotating specimen holder was used to implant Ca2+, P2+, and Sr2+ ions at energies of 100 KeV, 75 KeV and 180 KeV, respectively, using a low-energy accelerator to synthesize strontium-substituted hydroxyapatite at varying conditions. Ag2+ ions of energy 100 KeV were subsequently implanted on the as-formed surface at the near-surface region to provide anti-bacterial properties to the as-formed specimen. Results: The properties of the as-formed ion-implanted specimen were compared with the SrHA-Ag synthesized specimens by cathodic deposition and low-temperature high-speed collision technique. The adhesion strength of the ion-implanted specimen was 43 ± 2.3 MPa, which is well above the ASTM standard for Ca-P coating on Ti. Live/dead cell analysis showed higher osteoblast activity on the ion-implanted specimen than the other two. Ag in the SrHA implanted Ti by ion implantation process showed superior antibacterial activity. Discussion: In the ion implantation technique, nano-topography patterned surfaces are not concealed after implantation, and their efficacy in interacting with the osteoblasts is retained. Although all three studies examined the antibacterial effects of Ag2+ ions and the ability to promote bone tissue formation by MC3T3-E1 cells on SrHA-Ag/Ti surfaces, ion implantation techniques demonstrated superior ability. The synthesized specimen can be used as an effective implant in acetabular fracture sites based on their mechanical and biological properties.

Synthetic strategy for the production of electrically polarized polyvinylidene fluoride-trifluoroethylene-co-polymer osseo-functionalized with hydroxyapatite scaffold.

The physiological mechanism of bone tissue regeneration is intricately organized and involves several cell types, intracellular, and extracellular molecular signaling networks. To overcome the drawbacks of autografts and allografts, a number of synthetically produced scaffolds have been manufactured by integrating ceramics, polymers, and their hybrid-composites. Considering the fact that natural bone is composed primarily of collagen and hydroxyapatite, ceramic-polymer composite materials seem to be the most viable alternative to bone implants. Here, in this experimental study, copolymer PVDF-TrFE has been amalgamated with HA ceramics to produce composite scaffolds as bone implants. In order to fabricate PVDF-TrFE-HA (polyvinylidene fluoride-trifluoroethylene-hydroxyapatite) composite scaffolds, solvent casting-particulate leaching technique was devised. Two scaffold specimens were produced, with different PVDF-TrFE and HA molar ratios (70:30 and 50:50), and then electrically polarized to observe the subsequent polarization impact on the tissue growth and the suppression of bacterial cell proliferation. Both the specimens underwent characterization to analyze their biocompatibility and bactericidal activities. The bacterial culture of Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) bacteria on the composites was studied to understand the antibacterial characteristics. Moreover, MG63 cells cultured on these as-formed composites provided information about osteogenesis. Improved osteogenesis and antibacterial efficacy were observed on both the composites. However, the composite with 70 wt% PVDF-TrFE and 30 wt% HA showed a higher bactericidal effect as well as osteogenesis. It was found that PVDF-TrFE-HA-based biomaterials have the potential for bone tissue engineering applications.

Incorporation of hydroxyapatite and cerium oxide nanoparticle scaffold as an antibacterial filler matrix for biomedical applications.

Managing bone healing is essential for preventing problems such as non-union, bacterial infection, structural instability, psychological, and physical damage in patients. The need to use antibiotics less often has prompted researchers to look at possible substitutes, such as nanoparticles. In this investigation, we choose to employ cerium oxide nanoparticles due to their unique antibacterial properties based on redox reactions. The cerium oxide-hydroxyapatite composite was synthesized, calcined, and ball-milled to create a fine CeO2-HA powder. Luffa cylindrica sponge was used to prepare the scaffold, and X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the structural and morphological features. Rapid upregulation of osteogenesis marker genes confirmed that CeO2-HA nanoparticles in the scaffolds promoted osteoblast cell proliferation and osteogenic differentiation. The cell viability test was conducted by MTT assay. When the CeO2-HA composite was cultured with S. aureus, it showed signs of having more antibacterial efficacy than pure HA.

Mangiferin-Enriched Mn-Hydroxyapatite Coupled with ß-TCP Scaffolds Simultaneously Exhibit Osteogenicity and Anti-Bacterial Efficacy.

Biphasic calcium phosphate (BCP) containing ß-tricalcium phosphate and manganese (Mn)-substituted hydroxyapatite (HAP) was synthesized. Biomedical scaffolds were prepared using this synthesized powder on a sacrificial polyurethane sponge template after the incorporation of mangiferin (MAN). Mn was substituted at a concentration of 5% and 10% in HAP to examine the efficacy of Mn at various concentrations. The phase analysis of the as-formed BCP scaffold was carried out by X-ray diffraction analysis, while the qualitative observation of morphology and the osteoblast cell differentiation were carried out by scanning electron microscopy and confocal laser scanning microscopy techniques. Gene expressions of osteocalcin, collagen 1, and RUNX2 were carried out using qRT-PCR analyses. Significantly higher (p < 0.05) levels of ALP activity were observed with extended osteoblast induction on the mangiferin-incorporated BCP scaffolds. After characterization of the specimens, it was found that the scaffolds with 10% Mn-incorporated BCP with mangiferin showed better osteogenicity and simultaneously the same scaffolds exhibited higher anti-bacterial properties as observed from the bacterial viability test. This study was carried out to evaluate the efficacy of Mn and MAN in BCP for osteogenicity and antibacterial action.

Bio-mimicked guided tissue regeneration/guided bone regeneration membranes with hierarchical structured surfaces replicated from teak leaf exhibits enhanced bioactivity.

Bio-mimicked GTR/GBR membranes with hierarchical structured surfaces were developed by direct and indirect replication of teak leaf surface. The membranes were fabricated using solvent casting method with customized templates. The surfaces obtained were those with micro-trichomes (MTS) and micro-depression (MDS) that resembled a whorling pattern. Structural details of the fabricated membrane surfaces were studied under stereomicroscope and scanning electron microscopy. Surface roughness, water wetting angle, water uptake, and degradation properties of the membranes were examined. The effects of the micro-patterned hierarchical structure on in vitro bioactivities of human osteoblast-like cells (MG63) and human gingival fibroblast cells HGF1-RT1 were studied. In vivo study carried out on rat skulls to assess the response of surrounding tissues for 4 weeks showed that the bio-mimicked MTS and MDS membrane surfaces enhanced the cell proliferation. The proliferation significantly increased with increasing surface roughness and decreasing contact angle. There was also an evidence of rapid new bone maturation with membranes with MTS. It is thus suggested that the teak leaf mimicked whorling patterned hierarchical structured surface is an important design for enhancing bioactivity.

Electrically Polarized Withaferin A and Alginate-Incorporated Biphasic Calcium Phosphate Microspheres Exhibit Osteogenicity and Antibacterial Activity In Vitro.

Biphasic calcium phosphate microspheres were synthesized by the water on oil emulsion method and, subsequently, withaferin A was incorporated in the microspheres to evaluate their efficacy in biomedical applications. These withaferin A and alginate-incorporated biphasic calcium phosphate (BCP-WFA-ALG) microspheres were then negatively polarized, and the formation of biphasic calcium phosphates was validated by X-ray diffraction study. Although the TSDC measurement of the BCP-WFA-ALG microspheres showed the highest current density of 5.37 nA/cm2, the contact angle of the specimen was found to be lower than the control BCP microspheres in all the media. The water uptake into BCP-WFA-ALG microspheres was significantly higher than in the pure BCP microspheres. MTT assay results showed that there was a significant enhancement in cell proliferation rate with the BCP-WFA-ALG composite microspheres. The osteogenic differentiation of MG 63 cells on BCP-WFA-ALG microspheres exhibited an increased expression of osteogenic marker genes in the case of the BCP-WFA-ALG composite microspheres.

Ti-9Mn ß-type alloy exhibits better osteogenicity than Ti-15Mn alloy in vitro.

Ti-9Mn and Ti-15Mn were prepared using an arc furnace in order to understand their osteogenic behavior as a biomedical implant. Ti-9Mn surface showed a significantly lower contact angle value (41%) as compared with the Ti-15Mn surface. The higher Ra and lower hydrophilicity values of Ti-9Mn alloy as compared with Ti-15Mn alloy indicates that Ti-9Mn can have better osteoconductive properties. ALP activity of the osteoblast cells on the Ti-9Mn alloy was elevated by 45% on day 7 and 20% on day 14 as compared to the Ti-15Mn alloy that reflects faster induction of osteoblast phenotypes of MG63 cells. Filopodia and lamellipodia structures were spread more on the Ti-9Mn specimens as compared to the Ti-15Mn alloy. Cell viability on Ti-9Mn alloy increased by 25% and 32%, respectively after 7 and 14 days of culture as compared to Ti-15Mn alloy. On day 14 of culture, the relative expression of RUNX2, COL1, and OC on Ti-9Mn alloy were elevated by 35%, 21%, and 30% respectively than the Ti-15Mn alloy. Ti-9Mn alloy also exhibited an inductive effect on the cell proliferation, and upregulation in the expression of ALP, RUNX2, and OC that is, the genes related to osteoblastic differentiation. Hence, the present in vitro results suggest that Ti-9Mn can be a preferred implant material than the Ti-15Mn alloy.

Dual response of osteoblast activity and antibacterial properties of polarized strontium substituted hydroxyapatite-Barium strontium titanate composites with controlled strontium substitution.

To mimic the electrical properties of natural bone, controlled strontium substitution of both hydroxyapatite and ferroelectric barium titanate were achieved by mixing in the ratio 30:70 by weight. The composites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy to investigate the phase composition and microstructure of the composites. Unpolarized and polarized strontium hydroxyapatite (SrHA)-barium strontium titanate (BST) composites with controlled degree of Sr substitution were examined, including 5SrHA-5BST (5% Sr substitution in both components) and 10SrHA-10BST composites. The 10SrHA-10BST composite showed a higher osteoblast activity, as observed from the cell viability studies performed using CCK-8 assay. The polarized composites showed promise against Staphylococcus aureus bacteria by minimizing the adhesion and growth of bacteria, as compared with their unpolarized counterparts. The polarized 10SrHA-10BST was found to be superior than all other composites. As a result, the approach of polarization of SrHA-BST composites has been found to be an effective bone substitute material in controlled enhancement of osteoblast growth with simultaneous reduction of bacterial infection.

Estimation of Trace Elements, Antioxidants, and Antibacterial Agents of Regularly Consumed Indian Medicinal Plants.

Nutritional profile of minerals and antioxidants in Indian spice extracts was evaluated in order to examine their efficacy in treating various diseases, disorders, and allergies in human health. Extracts of four medicinal plants such as Curcuma longa, Zingiber officinale, Piper nigrum, and Piper longum, regularly consumed as spice products in South Asia, have been studied using elemental analysis, antioxidant, and antibacterial studies. While potassium (K) and calcium (Ca) were estimated to be the major elements, trace elements such as manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), and lead (Pb) were determined in the plant extracts. Although higher concentration of Cu was estimated in Piper nigrum extracts, it can be inferred that Cu is not the only factor that is responsible for gastrointestinal disorders. Methanolic extract of the plants showed the highest inhibition zone for Curcuma longa against maximum bacterial strains while Zingiber officinale showed inhibition against S. aureus, K. pneumonia, and P. aeruginosa. Because of the highest concentration of antioxidants and inhibitory action against most of the bacterial strains, Curcuma longa can be used as a co-therapeutic agent in healing gastrointestinal infections.

Analysis of grains grown on fly ash treated soils.

One time application of fly ash was done at the rate of 200 t/hectare in the crop lands in Odisha, India. The increase in yield of maize grains was 28% and 34% over the control values whereas the increase in yield of rice grains was 40% and 13% at Malud and Dhenkanal, respectively. The results indicated that fly ash is an amendment for soil which can improve the physical and chemical properties of deficient soil and improves the soil fertility and crop yield.

Elemental analysis of coal and coal ASH by PIXE technique.

Coal and coal ash samples were characterized by particle induced X-ray emission spectroscopic technique. Sixteen elements, namely K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Rb, Sr, Y and Pb were quantified in this study. Elements like K, Ca, Ti and Fe were present as major elements, whereas, other elements like V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr and Pb were present in trace level. The enrichment ratio of different ash samples with respect to coal were also estimated and discussed.

Analysis of ancient Indian silver punch-marked coins by external PIXE.

Seven silver punch-marked coins were analysed using external particle induced X-ray emission technique. The main group of elements like Ag, Cu, Au, Pb and Fe were estimated along with a number of trace/minor elements such as K, Ca, Ti, V, Cr, Mn, Co, Ni and Rb in the analysed silver coins. Gold was found in all the coins and varied between 0.7% and 6.2% indicating the better economic condition of that civilisation.

Surface characteristics and biological studies of hydroxyapatite coating by a new method.

Hydroxyapatite was coated on the Ti implants by a new coating method called low temperature high speed collision (LTHSC). Higher roughness values were estimated in the formed thick coating on the implant surface. While the roughness value was lower than plasma sprayed HA coatings, LTHSC HA-coated surface showed higher hydrophilicity. The cell proliferation of oseteoblastic cells evaluated by MTT assay showed that HA-coated surface had significantly higher cell viability than the control. The HA-coated surface showed higher mean total protein production even though there was no statistical difference between two surfaces. Osteoblast differentiation, ALP activity and expression of differentiation marker genes such as osteopontin and osteocalcin were elevated in the cells cultured on HA-coated surface and this surface also showed higher collagen protein expression than titanium control. Moreover, in experimental group, BIC values were significantly increased after 12 weeks of implantation and about 30-50% cortical bone-implant contact was observed.

Synthesis of spherical hydroxyapatite granules with interconnected pore channels using camphene emulsion.

The aim of this study was to fabricate porous spherical hydroxyapatite (HA) granules with interconnected pore channels for use as a bone graft substitute. Various weights of camphene porogen were mixed with nano-sized HA powder (camphene/HA = 0, 10, 30, 50, 70, and 90% w/w) and 10% gelatin aqueous solution then added to the mixture. The water-in-oil emulsion method was employed to obtain spherical-shaped granules, of which those 1000-2000 µm in diameter were selectively classified using a standard sieve set. Thermogravimetric analysis and X-ray diffraction were used to determine optimal sintering conditions. The sintered granules were characterized using field emission-scanning electron microscopy (FE-SEM), microcomputed tomography, and porosimetry. The pore size and porosity of spherical HA granules increased with the addition of camphene. Granules with a HA/camphene ratio of 90% (HG90) demonstrated macropores (>50 µm) with interconnected pore channels (porosity: 58.49%). In addition, FE-SEM examination of HG90 coated with polycaprolactone showed that the granule may hold promise as a drug delivery carrier. We concluded that these HG90 granules merit consideration as a bone graft substitute or drug delivery carrier in bone tissue engineering.

Surface modification of titanium and titanium alloys by ion implantation.

Titanium and titanium alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, titanium and its alloys cannot meet all of the clinical requirements. Therefore, to improve the biological, chemical, and mechanical properties, surface modification is often performed. In view of this, the current review casts new light on surface modification of titanium and titanium alloys by ion beam implantation.

Elemental analysis of silver coins by PIXE technique.

Elemental analysis of nine Indian silver coins during British rule was carried out by proton induced X-ray emission spectroscopy. Eight elements, namely Cr, Fe, Ni, Cu, Zn, As, Ag, and Pb were determined in the present study. Ag and Cu were found to be the major elements, Zn was the only minor element and all other elements are present at the trace level. The variation of the elemental concentration may be due to the use of different ores for making coins.

Analysis of Indian cholesterol gallstones by particle-induced X-ray emission and thermogravimetry-derivative thermogravimetry.

OBJECTIVES: It has been reported that the role of some minor elements plays a significant role in the formation of gallstones. The relationship between minor and trace element concentrations was established in the present investigation and the trace element profile of the current investigation was compared with the literature values of south Indian gallstone samples in order to determine their possible role in stone formation and growth. The rate of weight loss and classification of cholesterol type of gallstones were also investigated by thermal analysis. BASIC METHODS: The trace element profile of the cholesterol gallstones was determined by proton-induced X-ray emission spectroscopic technique and the thermal properties of the cholesterol stones were studied by thermogravimetry-derivative thermogravimetry analysis. RESULTS: It was observed that 14 minor/trace elements, namely S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb, were present in the cholesterol stone samples. The average concentration of Fe in south Indian (Chennai region) gallstone samples (503.4 ppm) is about 2.5 times more than that of the east Indian gallstone samples (205.0 ppm), whereas the concentration of Fe is still higher in other parts of south India (848.2 ppm) as analysed by Ashok et al. CONCLUSIONS: The higher concentration of Cu (in some parts of south India except the Chennai region) and Fe in south Indian cholesterol stone samples may be due to the intake of tamarind (Garcinia camborginia) as their regular food. The thermogravimetry and derivative thermogravimetry curves provided information on the thermal decompositions of cholesterol stones.