Design, clinical applications and post-surgical assessment of bioresorbable 3D-printed craniofacial composite implants.

This study details the design, fabrication, clinical trials' evaluation, and analysis after the clinical application of 3D-printed bone reconstruction implants made of nHAp@PLDLLA [nanohydroxyapatite@poly(L-lactide-co-D,L-lactide)] biomaterial. The 3D-printed formulations have been tested as bone reconstruction Cranioimplants in 3 different medical cases, including frontal lobe, mandibular bone, and cleft palate reconstructions. Replacing one of the implants after 6 months provided a unique opportunity to evaluate the post-surgical implant obtained from a human patient. This allowed us to quantify physicochemical changes and develop a spatial map of osseointegration and material degradation kinetics as a function of specific locations. To the best of our knowledge, hydrolytic degradation and variability in the physicochemical and mechanical properties of the biomimetic, 3D-printed implants have not been quantified in the literature after permanent placement in the human body. Such analysis has revealed the constantly changing properties of the implant, which should be considered to optimize the design of patient-specific bone substitutes. Moreover, it has been proven that the obtained composition can produce biomimetic, bioresorbable and bone-forming alloplastic substitutes tailored to each patient, allowing for shorter surgery times and faster patient recovery than currently available methods.

Cell viability assessment and ion release profiles of GICs modified with TiO2- and Mg-doped hydroxyapatite nanoparticles.

OBJECTIVES: To assess and compare the cell viability and ion release profiles of two conventional glass ionomer cements (GICs), Fuji IX and Ketac Molar EasyMix, modified with TiO2 and Mg-doped-HAp nanoparticles (NPs). METHODS: TiO2 NPs, synthesized via a sol-gel method, and Mg-doped hydroxyapatite, synthesized via a hydrothermal process, were incorporated into GICs at a concentration of 5 wt.%. The biocompatibility of prepared materials was assessed by evaluating their effects on the viability of dental pulp stem cells (DPSCs), together with monitoring ion release profiles. Statistical analysis was performed using One-way analysis of variance, with significance level p < 0.05. RESULTS: The addition of NPs did not significantly affect the biocompatibility of GICs, as evidenced by comparable decreased levels in cell viability to their original formulations. Distinct variations in cell viability were observed among Fuji IX and Ketac Molar, including their respective modifications. FUJI IX and its modification with TiO2 exhibited moderate decrease in cell viability, while other groups exhibited severe negative effects. While slight differences in ion release profiles were observed among the groups, significant variations compared to original cements were not achieved. Fluoride release exhibited an initial "burst release" within the initial 24 h in all samples, stabilizing over subsequent days. CONCLUSIONS: The addition of NPs did not compromise biocompatibility, nor anticariogenic potential of tested GICs. However, observed differences among FUJI IX and Ketac Molar, including their respective modifications, as well as induced low viability of DPSC by all tested groups, suggest the need for careful consideration of cement composition in their biological assessments. CLINICAL SIGNIFICANCE: The findings contribute to understanding the complex interaction between NPs and GIC matrices. However, the results should be interpreted recognizing the inherent limitations associated with in vitro studies. Further research avenues could explore long-term effects, in vivo performance, and potential clinical applications.

Comparative assessment of the remineralization characteristics of nano-hydroxyapatite extracted from fish scales and eggshells.

OBJECTIVES: Dentine hypersensitivity (DH) is a common concern in dentistry that has the potential to restrict daily activities and harm a person's quality of life. In this study, the remineralization characteristics of nano-hydroxyapatite (nHAp) extracted from waste eggshells and fish scales were comparatively assessed. MATERIALS AND METHODS: The extraction methods used to obtain nHAp from both fish scales and eggshells are also described. The effect of the extraction process and bio-waste source on the physicochemical characteristics of the nHAp such as Ca/P ratio, functional groups, crystallinity and phase change, and surface morphology are presented in the study. The remineralization properties were evaluated using dentine models (n = 15). A field scanning electron microscope was used to evaluate the effectiveness of the dentine tubules occlusion. The percentage occluded area for all the specimens was evaluated statistically using a one-way analysis of variance (α = 0.05). RESULTS: The results showed that there were variations in the physicochemical characteristics of the nHAp extracted, including the crystallinity, particle size, and surface morphology, and buffering effects against citric acids. The EnHAp extracted from eggshells had higher crystallinity, superior buffering effects, and smaller particle size compared to the nHAp extracted from fish scales, making it a more favourable material for remineralization of teeth. The statistical evidence showed that there were statistically significant differences in the dentine occluding properties measured in the nHAp (p < 0.001). The highest mean % occluded area was measured with the EnHAp group. CONCLUSIONS: The findings of this study provide insights into the use of bio-waste materials for the development of sustainable and effective products for oral health care.

Assessment of sol-gel derived iron oxide substituted 45S5 bioglass-ceramics for biomedical applications.

Magnetic bioactive glass-ceramic (MGC) powders with nominal compositions of (45 - x)SiO224.5CaO24.5Na2O6P2O5xFe2O3 (x = 2, 4, 6, 8, 10, and 15 wt%) have been synthesized by a sol-gel route by systematically substituting silicon dioxide with iron oxide in Hench's 45S5 glass composition. Powder X-ray diffraction studies revealed a variation in the percentage of combeite (Ca2Na2Si3O9), magnetite (Fe3O4), and hematite (Fe2O3) nanocrystalline phases in MGC powders as a function of composition. Zeta potential measurements showed that MGC containing up to 10 wt% iron oxide formed stable suspensions. The saturation magnetization and heat generation capacity of MGC fluids increased with an increase in iron oxide content. Degradation of MGC powders was investigated in phosphate buffered saline (PBS). The in vitro bioactivity of the MGC powders taken in pellet form was confirmed by observing the pH variation as well as hydroxyapatite layer (HAp) formation upon soaking in modified simulated body fluid. These studies showed a decrement in the overall bioactivity in samples with high iron oxide content due to the proportional decrease in the silanol group. Monitoring the proliferation of MG-63 osteoblast cells in Dulbecco's Modified Eagle Medium (DMEM) revealed that MGC with up to 10 wt% iron oxide exhibited acceptable viability. The systematic study revealed that the MGC with 10 wt% iron oxide exhibited optimal cell viability, magnetic properties and induction heating capacity, which were better than those of FluidMag-CT, which is used for hyperthermia treatment.

Effect of simulated body fluid formulation on orthopedic device apatite-forming ability assessment.

Integration of native bone into orthopedic devices is a key factor in long-term implant success. The material-tissue interface is generally accepted to consist of a hydroxyapatite layer so bioactive materials that can spontaneously generate this hydroxyapatite layer after implantation may improve patient outcomes. Per the ISO 22317:2014 standard, "Implants for surgery - In vitro evaluation for apatite-forming ability of implant materials," bioactivity performance statements can be assessed by soaking the material in simulated body fluid (SBF) and evaluating the surface for the formation of a hydroxyapatite layer; however, variations in test methods may alter hydroxyapatite formation and result in false-positive assessments. The goal of this study was to identify the effect of SBF formulation on bioactivity assessment. Bioglass® (45S5 and S53P4) and non-bioactive Ti-6Al-4V were exposed to SBF formulations varying in calcium ion and phosphate concentrations as well as supporting ion concentrations. Scanning electron microscopy and X-ray powder diffraction evaluation of the resulting hydroxyapatite layers revealed that SBF enriched with double or quadruple the calcium and phosphate ion concentrations increased hydroxyapatite crystal size and quantity compared to the standard formulation and can induce hydroxyapatite crystallization on surfaces traditionally considered non-bioactive. Altering concentrations of other ions, for example, bicarbonate, changed hydroxyapatite induction time, quantity, and morphology. For studies evaluating the apatite-forming ability of a material to support bioactivity performance statements, test method parameters must be adequately described and controlled. It is unclear if apatite formation after exposure to any of the SBF formulations is representative of an in vivo biological response. The ISO 23317 standard test method should be further developed to provide additional guidance on apatite characterization and interpretation of the results.

Assessment of Streptococcus mutans biofilm formation on calcium phosphate ceramics: The role of crystalline composition and microstructure.

Streptococcus mutans is one of the bacteria that initiates the colonization of the pellicle at the tooth surface. It forms a plaque, together with other bacteria, which gradually dissolves the pellicle and leaves the tooth surface unprotected against the acidic oral environment. Calcium phosphate ceramics are excellent synthetic materials for the study of biofilm formation in dentistry because they are comparable to teeth in chemical composition and structure. Calcium phosphates can be processed to achieve a variety of crystalline compounds with biologically relevant ionic substitutions and structures that allow study of the effect of the surface chemistry and the topography independently. In this article, we describe the preparation and characterization of three types of calcium phosphate-based materials as a suitable surface for the formation of the S. mutans biofilm: beta-tricalcium phosphate (ß-TCP); sintered hydroxyapatite (SHA); and calcium-deficient hydroxyapatite (CDHA). The densest biofilms were formed on the surfaces of SHA and CDHA, with no significant differences due to the stoichiometry or microstructure. In contrast, ß-TCP showed a lower susceptibility to S. mutans biofilm formation, suggesting that the crystalline structure is the controlling parameter. Subsequently, SHA was selected to develop a dental biofilm model that allowed study of S. mutans biofilm susceptibility to chlorhexidine and ethanol.

Assessment of protein adhesion behaviour and biocompatibility of magnesium/Co-substituted HA-based composites for orthopaedic application.

Protein adsorption has a great influence on Mg-based metallic implants, which affects cell attachment and cell growth. Adsorption of the proteins (via electrostatic interaction, hydrophobic/hydrophilic, and hydrogen-bonding) on the implant surface is greatly influenced by the surface chemistry of the implant. Hydroxyapatite (HA) is a class of CaP ceramic, beneficial for protein adsorption as it possesses Ca2+ and PO43- in it, which are believed to be the protein binding sites on the HA surface. Moreover, HA is the popular choice for reinforcement in the magnesium matrix owing to its similarity with bone mineral composition. However, negligible interaction between HA and Mg particles during sintering is the major limitation for frequent usage of Mg-HA implants. Doping of HA with Mg2+ and Zn2+ (CoHA) ions leads to its chemistry similar to natural apatite in human bone and facilitates comparatively better bonding with the MgZn matrix. This study mainly aims to delve into the protein adsorption behaviour of Magnesium/Co-substituted HA-based Composites (M3Z-CoHA) along with their biocompatibility. Qualitative and quantitative protein adsorption analysis shows that the addition of 15 wt% CoHA to Mg matrix enhanced protein adsorption by ~60% and renders cell viability >90% after day 1, supporting cellular growth and proliferation. The implants also initiated osteogenic differentiation of the cells after day 7. The leached-out products from all the composites showed no toxicity. The morphology of the cells in all the composites was found as healthy as the control cells. Overall, the composite with 15 wt% HA reinforcement (M3Z-15CoHA) has shown favourable protein adsorption behaviour and cytocompatibility.

Octacalcium Phosphate for Bone Tissue Engineering: Synthesis, Modification, and In Vitro Biocompatibility Assessment.

Octacalcium phosphate (OCP, Ca8H2(PO4)6·5H2O) is known to be a possible precursor of biological hydroxyapatite formation of organic bone tissue. OCP has higher biocompatibility and osseointegration rate compared to other calcium phosphates. In this work, the synthesis of low-temperature calcium phosphate compounds and substituted forms of those at physiological temperatures is shown. Strontium is used to improve bioactive properties of the material. Strontium was inserted into the OCP structure by ionic substitution in solutions. The processes of phase formation of low-temperature OCP with theoretical substitution of strontium for calcium up to 50 at.% in conditions close to physiological, i.e., temperature 35-37 °C and normal pressure, were described. The effect of strontium substitution range on changes in the crystal lattice of materials, the microstructural features, surface morphology and biological properties in vitro has been established. The results of the study indicate the effectiveness of using strontium in OCP for improving biocompatibility of OCP based composite materials intended for bone repair.

Temporal, spatial and gender-based dietary differences in middle period San Pedro de Atacama, Chile: A model-based approach.

To explore the possible emergence and lived consequences of social inequality in the Atacama, we analyzed a large set (n = 288) of incredibly well preserved and contextualized human skeletons from the broad Middle Period (AD 500-1000) of the San Pedro de Atacama (Chile) oases. In this work, we explore model-based paleodietary reconstruction of the results of stable isotope analysis of human bone collagen and hydroxyapatite. The results of this modeling are used to explore local phenomena, the nature of the Middle Period, and the interaction between local situations and the larger world in which the oases were enmeshed by identifying the temporal, spatial, and biocultural correlates and dimensions of dietary difference. Our analyses revealed that: 1) over the 600-year period represented by our sample, there were significant changes in consumption patterns that may evince broad diachronic changes in the structure of Atacameño society, and 2) at/near 600 calAD, there was a possible episode of social discontinuity that manifested in significant changes in consumption practices. Additionally, while there were some differences in the level of internal dietary variability among the ayllus, once time was fully considered, none of the ayllus stood out for having a more (or less) clearly internally differentiated cuisine. Finally, sex does not appear to have been a particularly salient driver of observed dietary differences here. While we do not see any de facto evidence for complete dietary differentiation (as there is always overlap in consumption among individuals, ayllus, and time periods, and as isotopic analysis is not capable of pinpointing different foods items or preparations), there are broad aspects of dietary composition changing over time that are potentially linked to status, and foreignness. Ultimately, these stand as the clearest example of what has been termed "gastro-politics," potentially tied to the emergence of social inequality in the San Pedro oases.

Laser fabrication of structural bone: surface morphology and biomineralization assessment.

The current work explores the surface morphology of the laser-ablated bone using Yb-fiber coupled Nd:YAG laser (λ = 1064 nm) in continuous wave mode. As the laser-ablated region contains physiochemically modified carbonized and nonstructural region, it becomes unknown material for the body. Thus, biomineralization on such a laser-ablated region was assessed by in vitro immersion test in noncellular simulated body fluid. The presence of hydroxyapatite was detected in the precipitated mineral product using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction analysis. The effect of varying laser parameters on distribution of surface morphology features was identified and its corresponding effect on biomineralization was studied.

Stabilization of borate by hot isostatic pressing after co-precipitation with hydroxyapatite using MAP.

Boric acid is one of the most mobile inorganic contaminant species in nature due to its pKa of 9.23. Co-precipitation of borate with hydroxyapatite (HAp: Ca5(PO4)3OH) facilitates the simultaneous removal of borate with co-existing oxoanions in natural waters. The cost of phosphate is an impediment to industrialize the co-precipitation of borate with HAp for treatment of geothermal waters. In the present work, an inexpensive industrial by-product of magnesium ammonium phosphate (MAP) derived from sewage sludge, was examined as a phosphate source. MAP includes 89% pure magnesium ammonium phosphate, resulting in better performance than the pure chemical form of NH4H2PO4, because Mg2+ and Al3+ (trace elements in MAP product) play roles in enhancing the removal rate of borate and lowering the equilibrium borate concentration. These ions have a good affinity with phosphate to nucleate crystal seeds independently of powdery Ca sources. To reduce the bulky volume of solid residues, hot isostatic pressing (HIP) was applied. There is structural water in HAp; therefore, the greatest volume reduction was achieved with 78.3 ± 2.0% (n = 3). Additionally, a synergic effect to suppress the released borate, greater than the sequential combination of calcination and cold isostatic pressing was accomplished in the toxicity contents leaching procedure (TCLP) test. This is not due to larger crystal sizes alone, but it is derived from boron stabilization in HAp at an atomic level by the synergic effect of heating and pressing simultaneously.

Antibacterial alginate/nano-hydroxyapatite composites for bone tissue engineering: Assessment of their bioactivity, biocompatibility, and antibacterial activity.

Bone substitute materials based on bioceramics and polymers have evolved shifting from a passive role where they are merely accepted by the body; to an active role, where they respond to particular environmental conditions or to different types of cues generating suitable integration (osseointegration for this case) inside the host tissue. In this work, two types of composite materials based on a bioceramic (synthetic nano-hydroxyapatite, HA) and a biopolymer (sodium alginate, ALG) have been designed and assessed for promoting the bone regeneration. These materials were loaded with ciprofloxacin (CIP) for obtaining, not only a suitable material for a filling but with antibacterial properties. Therefore, their main features were studied through Fourier transformed-infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ultraviolet-Visible (UV-Vis) spectroscopy was used for obtaining the released concentrations of CIP and Zeta-potential (ζ-potential) was used for characterizing the adsorption of CIP onto nanoparticles. The release profile of this drug has been fit with the Ritger-Peppas model, used for studying the release kinetics of hydrogel-based systems. The bioactivity of these composites was also evaluated after 30 days of incubation in a simulated body fluid solution (SBF). Then, the assessment of antibacterial capability against the three main strains cause osteomyelitis was performed. Finally, the cell viability study and the cellular morphology assay were also carried out. These last assays have shown encouraging results and, gathered with their other properties, such as their bioactivity and antibacterial properties; they could lead to propose these materials as new bone filler antibiotic devices.

A practical assessment of nano-phosphate on soybean (Glycine max) growth and microbiome establishment.

The efficacy of needle-shaped nano-hydroxyapatite (nHA; Ca10(PO4)6(OH)2) as a phosphate (Pi) fertilizer was evaluated as well as its impact on soil and soybean (Glycine max) bacterial and fungal communities. Microbial communities were evaluated in soy fertilized with nHA using ITS (internal transcribed spacer) and 16S rRNA high-throughput gene sequencing. Separate greenhouse growth experiments using agriculturally relevant nHA concentrations and application methods were used to assess plant growth and yield compared with no Pi (-P), soluble Pi (+P), and bulk HA controls. Overall, nHA treatments did not show significantly increased growth, biomass, total plant phosphorus concentrations, or yield compared with no Pi controls. Soil and rhizosphere community structures in controls and nHA treatment groups were similar, with minor shifts in the nHA-containing pots comparable to bulk HA controls at equal concentrations. The implementation of nHA in an agriculturally realistic manner and the resulting poor soy growth advises that contrary to some reports under specialized conditions, this nano-fertilizer may not be a viable alternative to traditional Pi fertilizers. If nano-phosphate fertilizers are to achieve their conjectured agricultural potential, alternative nHAs, with differing morphologies, physicochemical properties, and interactions with the soil matrix could be investigated using the evaluative procedures described.

Ultrasonic-assisted recycling of Nile tilapia fish scale biowaste into low-cost nano-hydroxyapatite: Ultrasonic-assisted adsorption for Hg2+ removal from aqueous solution followed by "turn-off" fluorescent sensor based on Hg2+-graphene quantum dots.

This study was planned to recycle calcium and the phosphorus-rich Nile tilapia fish scale biowaste into nano-hydroxyapatite (FHAP), using ultrasonic-assisted extraction of calcium and phosphorus from fish scales, which was optimized in term of extraction time, acid concentration, extraction temperature, and ultrasonic power. These two elements were determined simultaneously by inductively coupled plasma atomic emission spectrometry and the FHAP phase was formed upon addition of the extracted element solution in alkaline medium using homogenous precipitation assisted with ultrasound energy. The FHAP adsorbent was characterized by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller. A combination of FHAP and the ultrasonic method was then used to remove Hg2+ from aqueous solution. Four significant variables affecting Hg2+ removal, namely, adsorbent dosage, pH, ultrasonic power, and adsorption time, were studied. The results exhibited that the optimal conditions for maximizing the removal of Hg2+ were 0.02 g adsorbent dosage, pH 8, 0.4 kW ultrasonic power, 20 min adsorption time, and 30 °C adsorption temperature. The sorption mechanism of Hg2+ was revealed by isotherm modeling, indicating that FHAP adsorbent has a potential for Hg2+ removal in aqueous media with the maximum adsorption capacity being 227.27 mg g-1. This adsorption behavior is in agreement with the Langmuir model as reflected by a satisfactory R2 value of 0.9967, when the kinetics data were fitted with pseudo-second-order. Therefore, the FHAP could be an alternative adsorbent for the ultrasonic-assisted removal of Hg2+ at very high efficiency and within a very short period of time.

Synthesis of silver @hydroxyapatite nanoparticles based biocomposite and their assessment for viability of Osseointegration for rabbit knee joint anterior cruciate ligament rehabilitation.

In this examination, chitosan-silk fibroin/polyethylene terephthalate (CTS-SF/PET), chitosan-silk fibroin/polyethylene terephthalate/hydroxyapatite (CTS-SF/PET/HAP) and chitosan-silk fibroin/polyethylene terephthalate/Silver @hydroxyapatite (CTS-SF/PET/Ag@HAP) scaffolds were prepared by utilizing the plasma splashing procedure. Field emission scanning electron microscopy (FESEM) results demonstrated that the outside of the PET covered with HAP nanoparticles. The cell viability results demonstrated that the number of Mesenchymal stem cells (MSCs) primarily spread out on CTS-SF/PET/Ag@HAP. RT-PCR results demonstrated that there was an upregulated mRNA articulation of osseous development-related properties in the CTS-SF/PET/Ag@HAP composite. The in vivo rabbit animal assessment scores of the CTS-SF/PET/Ag@HAP composite were significantly better than those of the CTS-SF/PET at 1 to 3 months. Both in-vivo and in-vitro results exhibited in this investigation recommend that the cytocompatibility and osseointegration of CTS-SF/PET/Ag@HAP tendon were fundamentally improved by expanding the multiplication of cells and up-regulating the outflow of tendon development-related properties. In conclusion, the CTS-SF/PET/Ag@HAP tendon is a promising candidate for Anterior Cruciate Ligament (ACL) replacement in the future.

Synthesis and assessment of metallic ion migration through a novel calcium carbonate coating for biomedical implants.

Titanium (Ti) implants are commonly regarded as well accepted by the body. However, metal ion release is still a cause for concern. A small decrease in pH, which can be caused by inflammation, may produce a large increase in the corrosion rate of Ti implants. Coating the alloy with a buffer layer could have a significant protective effect. In this study, a calcium carbonate coating was developed on commercially pure Ti and a Ti-6Al-4V alloy through a hydrothermal treatment of previously NaOH-treated surfaces in calcium-citric acid chelate complexes. The results showed that a superstructured calcite coating layer formed on the Ti substrate after treatment at 170°C for 3 hr. The coating was approx. 1 µm thick and covered the substrate surface uniformly. When prolonging the hydrothermal treatment from 5 hr to 24 hr, the rhombohedral structure of calcite was observed in addition to the superstructure of calcite. Dissolution test results showed no significant differences in solution pH between the coated- and un-coated samples. However, the CaCO3 coating reduced by approx. 2-5 times the Ti and V ion release from the substrate as compared to the uncoated material, at pH 4. CaCO3 and hydroxyapatite (HA) coatings gave nonsignificant effects at neutral pH although the HA coating showed a trend for better results at the longer time points. The reduction in metal ion release from the substrate and the buffering ability of the CaCO3 coating encourage further studies on this coating for clinical applications.

Prevalence and incidence of non-gout crystal arthropathy in southern Sweden.

OBJECTIVE: To estimate the prevalence and incidence of non-gout crystal arthropathy in relation to socioeconomic factors in southern Sweden. METHODS: All patients (age ≥ 18 years) with at least one visit to a physician with the diagnosis of interest in the Skåne region (population of 1.3 million) in 1998-2014 were identified. Non-gout crystal arthropathy (ICD-10 codes M11.0-M11.9) was subclassified in four different groups: calcium pyrophosphate crystal deposition related arthropathy (CPPD), unspecified non-gout arthropathies, chondrocalcinosis, and hydroxyapatite crystal deposition disease. The crude and age-adjusted point prevalence on December 31, 2014, and the cumulative incidence during 2014 were calculated for all non-gout crystal arthropathies, CPPD, and other unspecified non-gout arthropathies overall and in relation to occupation, income, and level of education. RESULTS: The crude 2014 point prevalence (95% CI) and 2014 cumulative incidence (95% CI) of all non-gout crystal arthropathies were 0.23% (0.23-0.24) and 21.5 (19-25) cases/100,000 persons. Mean age (range) among all prevalent cases in 2014 was 71 (20-102) years and 56% were males. The point prevalence and cumulative incidence of CPPD were 0.09% (0.08-0.09) and 8 (7-10)/100,000 persons, respectively. The corresponding data for unspecified non-gout crystal deposition disease was 0.16% (0.16-0.17) and 15.6 (13-18)/100,000 persons, respectively. The prevalence and incidence of CPPD and unspecified non-gout crystal arthropathies were slightly higher in men and increased with age irrespective of gender. Unspecified non-gout crystal arthropathy but not CPPD was less prevalent in persons with ≥ 15 years of education, whereas there were no clear associations with occupation and income. CONCLUSION: The prevalence of all diagnosed non-gout crystal arthropathies was 0.23%, thus considerably less prevalent than gout in southern Sweden. CPPD and other unspecified non-gout crystal arthropathies are the predominant diagnoses, increasing with age and in men. With the exception for unspecified non-gout crystal arthropathies being inversely correlated to a higher level of education, no convincing association with the socioeconomic factors was found.

In-vivo assessment of minerals substituted hydroxyapatite / poly sorbitol sebacate glutamate (PSSG) composite coating on titanium metal implant for orthopedic implantation.

Currently, bio-mimetic material synthetic processes are involved in bone implant design which is closely related to natural bone. In this work, Zinc, Cerium and Selenium substituted hydroxyapatite/ Poly (sorbitol sebacate glutamate) (Zn, Ce, Se-HAP/PSSG, M-HAP/PSSG) composite was prepared by sol-gel method as a bio-mimetic materials for bone implantation. The physiochemical characterizations of M-HAP/PSSG was analyzed by Fourier transform infra red (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX) and High resolution transmission electron microscopy (HRTEM). Then, the prepared M-HAP/PSSG composite was compared with HAP/PSSG, Zn-HAP/PSSG, Ce-HAP/PSSG and Se-HAP/PSSG composites in order to evaluate the influence of single minerals on HAP matrix. Then the coating ability of the final better M-HAP/PSSG composite on surface treated titanium (Ti) was investigated to evaluate the perfection of implant material. The higher micro-hardness was observed on M-HAP/PSSG composite coated Ti (305.92 ±â€¯20.42) due to the presence of multi-minerals as well as the co-polymer PSSG when compared with M-HAP coated Ti plate (273.0 ±â€¯15.75). The bio-compatibility and osteogenic activity evaluation of all prepared composite on human osteoblasts MG-63 cells shows that the better cell attachment, proliferation and differentiation was observed by M-HAP/PSSG bio-composites when compared with other composites. Histological staining and X-ray photographs of in-vivo rat model confirms that the formation of new tibial bone when the defected rat was treated with M-HAP/PSSG composite coated Ti implant. In conclusion, the bio-composite M-HAP/PSSG is better scaffold for coating on the surface of Ti implant for orthopedic implantation.

Environmental hazard assessment for polymeric and inorganic nanobiomaterials used in drug delivery.

BACKGROUND: The increasing development and use of nanobiomaterials raises questions about their potential adverse effects on the environment after excretion and release. Published ecotoxicological data was searched for five polymeric nanobiomaterials [chitosan, polylactic acid (PLA), polyacrylonitrile (PAN), polyhydroxyalkanoates (PHA), and poly(lactic-glycolic acid) (PLGA)] and one inorganic nanobiomaterial [hydroxyapatite (HAP)] to evaluate the environmental hazards for freshwater and soil using a meta-analysis. If enough data was available, a probabilistic species sensitivity distribution (pSSD) and from this a predicted no effect concentration (PNEC) was calculated. If only one data point was available, a PNEC was calculated based on the most sensitive endpoint. Each material was classified either as "nano" or "non-nano", depending on the categorization in the original articles. When the original article specified that the material consisted of nanoparticles, the material was classified as nano; when nothing was mentioned, the material was classified as "non-nano". RESULTS: For PLA, PHA and PLGA, no published data on ecotoxicity was found and therefore no hazard assessment could be conducted. In soils, HAP was found to have the lowest PNEC with 0.3 mg/kg, followed by PAN and chitosan. In freshwater, chitosan was found to have the lowest PNEC with 5 µg/l, followed by nano-chitosan, HAP and PAN. CONCLUSION: Compared with other common pollutants, even the most sensitive of the selected nanobiomaterials, chitosan, is less toxic than engineered nanomaterials such as nano-ZnO and nano-Ag, some common antibiotics, heavy metals or organic pollutants such as triclosan. Given the current knowledge, the nanobiomaterials covered in this work therefore pose only little or no environmental hazard.

Synthesis, characterization and cytocompatibility assessment of hydroxyapatite-polypyrrole composite coating synthesized through pulsed reverse electrochemical deposition.

Composite coating of hydroxyapatite-polypyrrole is synthesized with the help of pulsed reverse electrochemical deposition method from aqueous bath through in-situ formation and co-deposition of both phases simultaneously over metallic stainless steel surface. The inter phase bonding along with surface energy variation and morphology is tuned with the help of deposition current density, deposition time and reverse duty cycle. Hydroxyapatite (HA) lattice exhibits unidirectional growth along the highest atomic plane of 〈111〉 parallel to the coating surface. Different kind of deposited hydroxyapatite structures, namely lamellar and spherical particle scaffold, are observed at moderate and high current densities respectively together with the incorporation of polypyrrole (PPy) phase in between. Pyrrole ring stretching and bond strengthening represent the bonding with hydroxyapatite lattice, which in turn helps to increase the overall corrosion resistance of composite coating by ten-fold as compared to bare PPY coating. The coating deposited with moderate current density (10 mA/cm2) seems to be the optimum one regarding the faster-interconnected growth of MG63 cells over the coating surface along with highest corrosion resistance and anodic passivation capability. Presence of sub-micron level ceramic hydroxyapatite scaffold along with polymer filler material makes this composite biocompatible coating as a potential candidate to use over the load bearing metallic implant surfaces due to its sufficient elasticity along with superior toughness.