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Hydroxyapatite (HAp) is basically calcium phosphate and the main inorganic component in natural bone and teeth structure. Animal bones and eggshells are mass-generated bio-wastes, and their calcium-rich structure makes them suitable precursors for bioactive HAp synthesis through biomimetic mineralisation. Industrial wastewater discharge is a worldwide alarming problem due to high-capacity industrial-scale processes, and their adverse effects on human health and environment will be encountered long term. Adsorption is the most widely used separation process in wastewater treatment, in which HAp particles can be used as bio-adsorbents for wastewater treatment processes due to their bioactive nature. Utilisation of bio-waste-derived HAp particles for wastewater treatment applications would be a step towards sustainable development and circular economy concepts. It promotes the reuse and recycle rate of bio-wastes as bio-adsorbents through an effective waste management strategy and increases the circularity of the material in the production chain. This study offers a brief overview of articles published in 2023 on the use of bio-waste-derived HAp particles for wastewater treatment. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Trauma & Emergency Surgery / Ulusal Travma ve Acil Cerrahi Dergisi is the property of KARE Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Les je v krožnem biogospodarstvu prepoznan kot obetavna surovina, saj ima sposobnost skladiščenja ogljika, ki pa je pogojena z življenjsko dobo izdelka. Podaljšanje življenjske dobe lesa lahko dosežemo z ustrezno zaščito, pogosto z uporabo kemikalij, ki so lahko okolju in ljudem nevarne. Mineralizacija lesa s hidroksiapatitom predstavlja potencial za okolju prijazno zaščito lesa. Na primeru Plečnikove parkovne klopce, mineralizirane s hidroksiapatitom, sta bili izvedeni LCA in LCC analizi. Analiza LCA je temeljila na standardih EN ISO 14040 in EN ISO 14044, analiza LCC je bila prilagojena po vmesniku Evropske komisije za javna naročila. Pri primerjavi mineraliziranega lesa z življenjsko dobo 16 oz. 24 let z referenčnim (nemineraliziranim) lesom so rezultati pokazali, da je mineraliziran les z življenjsko dobo 24 let okolju najprijaznejša in hkrati najcenejša izbira. Največje negativne vplive na okolje je predstavljal mineraliziran les z življenjsko dobo 16 let, najdražja alternativa je bil referenčni les.

Which is the nearest of the bone structure of calcium phosphate rate (HAp, Ca10(PO4)6(OH)2) is hydroxyapatite. However, it is known that the mechanical properties of hydroxyapatite (HAp) such as strength and hardness are increased with polymer additives. Chitosan (CTS) was used as the polymer due to its low toxicity and high biocompatibility properties. Two types of chitosan were used while making HAp/CTS coatings. Medium molecular weight (MMW) and high molecular weight (HMW). The effect of HAp/CTS biocomposite coatings by doping with medium and high molecular weight chitosan was investigated. The coatings were produced by the ultrasonic assisted electrophoretic method. Their crystallographic and morphological structures were examined by FT-IR, XRD and SEM. The structure of the sample become more homogeneous as the high molecular weight chitosan value increased. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ege University School of Dentistry / Ege Üniversitesi Dis Hekimligi Fakültesi Dergisi is the property of Ege University Faculty of Dentistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the applicability of hydroxyapatite (HA) coatings on Al-Cu-Mg alloys (Al2024) was investigated by electrochemical techniques. The structural characterizations of the coated layers were investigated by SEM, EDS, and XRD equipment. The surface adhesion resistance and electrochemical degradation behavior were tested by scratch and potentiodynamic scanning (PDS) tests, respectively. It was observed that the HA coating had a homogeneous structure on the Al2024 surfaces, but some local areas could not be adequately coated with HA from the cross-section images. Also, the coating surfaces were microporous morphology, which is specific to the HA coatings. From the scratch test results of the coating, it was predicted that the critical load resistance (Lc1), 12N, would be sufficient for biomedical applications. Electrochemical corrosion tests revealed that HA coating decreased the corrosion current density (Icorr) and corrosion rate of the Al2024 alloy (0.885 and 5.260 μA·cm-2 for HA-coated and uncoated Al2024 alloy, respectively). However, despite the low Icorr value obtained with HA coating, it was observed that both Icorr and passivation current density (Ipass) values (3.15 μA·cm-2 for HA coating, 0.03 to 0.08 μA·cm-2 for different types of titanium alloys) were insufficient when compared to commercial titanium alloys. [ABSTRACT FROM AUTHOR]

Biyoimplant mühendisliği hasarlı dokuları ve organları onarmak, tamir etmek ya da korumayı amaçlamaktadır. Her yıl çok sayıda insan kaza ya da çeşitli hastalıklardan kaynaklı olan iskelet kusurlarındaki kemikleri onarmak/tamir etmek istemektedir. Bu nedenle üzerinde yeni kemik büyümesinin oluşabileceği iskeleleri oluşturabilmek çok farklı biyomalzeme türleri kullanılmıştır. Hidroksiapatit, apatit wollostonit ve karbon temelli biyomalzemeler bu amaçla kullanılmıştır. Karbon nanomateryal baskılı iskeleler ticari olarak ulaşılabilirlik, mekanik stabilite, biyolojik uyumluluk özelliklerinden dolayı kullanımı oldukça yaygın biyomalzeme grubudur. Karbon esaslı iskeleler osteojenikfarklılaşma, kemik doku yenilenmesi, etkili hücre çoğalması özelliği göstermektedir. Kemik iskeleleri doku mühendisliğinde kemik büyümesi, yenilenmesi, tamiri, kemik dokusu hücrelerinde farklılaşma, adhezyon için temel yapı taşı olarak görülmektedir. Kemik iskeleleri gibi hareket eden çok sayıda karbon nanomateryali mevcuttur. Karbon nanotüpler, grafen ve fulleren kemik iskelesi olarak kullanılabilen karbon esaslı malzemelerin başlıcalarıdır. Grafen ve türevleri dikkat çekici fiziksel, kimyasal ve biyolojik özelliklere sahip 2D karbon esaslı bir malzemedir. Grafen mükemmel elektriksel iletkenliği, biyouyumluluğu, yüzey alanı ve termal özellikleri yüzünden bilim dünyası tarafından ilgi görmektedir. Grafenin tabakaları yüksek mekanik dirence ve yüksek spesifik yüzey alanına sahiptir. Dahası grafenin kök hücre farklılaşmasını ve biyomateryal özelliklerini geliştirdiği literatürde raporlanmıştır. Gerçekleştirilen çalışmada grafenin biyouyumluluk özellikleri, grafenin biyomateryal olarak kullanımına dair son çalışmalar ve karbon temelli maddelerin klinik olarak uygulanabilmesi amacıyla biyogüvenlik tartışmaları incelenmiştir.

In this study, hydroxyapatites (FSHAp and ESHAp) from natural waste materials (fish bones and egg shells) were successfully synthesized and their physicochemical properties were characterized. Cu(II) ion adsorption potentials of FSHAp and ESHAp particles under different experimental conditions (pH, different adsorbent and Cu(II) concentration, contact time and temperature) were optimized by using the Response Surface Methodology (RSM), and their Cu(II) adsorption capacities were compared. The surface morphology, crystal structure, elemental contents, surface area and pore ratios of produced hydroxyapatitebased adsorbents were determined by using FTIR, SEM-EDX, XRD characterization techniques. Isotherm and kinetic models were calculated to determine their adsorption mechanism, and the results showed that the Cu(II) adsorption process of FSHAp and ESHAp particles was more suitable for the Tempkin and Scarthard isotherm models and the pseudo-second order kinetic model. The optimum adsorption capacity for Cu(II) removal for FSHAp and ESHAp particles were obtained as 19.4 mg/g and 10.6 mg/g, respectively (pH 5.5, 90 mg Cu(II)/L, 2g/L adsorbent concentration, 25℃ and 25 min). Desorption and regeneration studies have shown that adsorbents can be used effectively for up to three consecutive cycles. The results of this study revealed that FSHAp and ESHAp particles can be used as alternative, environmentally friendly, low-cost adsorbents for Cu(II) removal from aqueous environments and environmental improvements in the perspective of zero waste approach. [ABSTRACT FROM AUTHOR]

Metallic biomaterials are widely used in the orthopedic and dental applications owing to their advanced biocompatibility and sophisticated mechanical properties. Many studies are carried out to develop new alloys with high specific strength, high corrosion resistance and high biocompatibility as an alternative to present metallic biomaterials. Mg alloys are potential alloys as a biomaterial, especially because they have low density and high biocompatibility. However, especially the corrosion properties of Mg alloys need to be improved. In this study, the surfaces of AZ31, AZ61 and AZ91 alloys, which are promising as biomaterials, were coated with hydroxyapatite with high biocompatibility, and the effects of the bioceramics coatings on corrosion resistance were comprehensively investigated. Crack-free and porous surface morphologies were obtained in all bioceramic coatings and the presence of the coatings on the surfaces was supported by EDS analysis. As a result of the corrosion tests performed in SBF, it was determined that the AZ91 alloy had the highest corrosion resistance among the uncoated samples. The hydroxyapatite bioceramic coatings also improved the corrosion properties of all samples. However, among all samples, the highest corrosion resistance was obtained in the hydroxyapatite coated AZ91 alloy. [ABSTRACT FROM AUTHOR]

Copyright of Acta Facultatis Medicae Naissensis is the property of Nis University, Faculty of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstrak Biokeramik hidroksiapatit (HAp) adalah suatu komponen kimiawi sintetik dari turunan kalsium fosfat yang banyak digunakan untuk memperbaiki kerusakan jaringan keras. Salah satu bahan alami untuk membuat hidroksiapatit adalah cangkang kerang simping (Amusium pleuronectes), hasil samping dari usaha penangkapan kerang simping. Tujuan penelitian ini untuk menghasilkan sediaan HAp dari cangkang kerang simping dan mengkarakterisasi sediaan hidroksiapatit yang dihasilkan. Tahapan yang dilakukan adalah persiapan tepung cangkang kerang, proses kalsinasi dengan perlakuan suhu (700, 800, dan 900°C) dan waktu (6; 4,5; dan 3 jam), serta sintesis HAp menggunakan amonium dihidrogen fosfat. Hasil HAp terbaik diperoleh dari perlakuan suhu kalsinasi 800°C selama 4,5 jam dengan rendemen 75,20%. Gugus fungsi CO32- yang muncul mengindikasikan adanya vibrasi C-O dari gugus CO3 dan gugus hidrogen fosfat (HPO42-). Difraktogram HAp yang dihasilkan mendekati standar (HAp-S) dengan intensitas tinggi pada nilai 2θ: 25,88°; 31,75°; 32,18°; 32,88°; 34,05°; 39,77°; 46,61°; dan 49,97°. HAp yang dihasilkan memiliki unsur Ca dan P masing-masing 59,09 dan 40,91% dengan rasio Ca/P sebesar 1,44 dan diameter partikel rata-rata 396,88 nm. HAp ini memiliki morfologi berbentuk aglomerat dan tidak terdapat permukaan dengan tepi runcing dan tajam sehingga relatif aman untuk diaplikasikan pada jaringan lunak manusia. Abstract Hydroxyapatite bioceramic (HAp) is a synthetic chemical component of calcium phosphate derivatives generally used to repair hard tissue damage. One of the natural ingredients for making hydroxyapatite is scallop shells (Amusium pleuronectes), a by-product of catching fresh scallops, which only use the adductor meat/muscle. This study aimed on HAp preparations from scallop shells and characterized the resulting hydroxyapatite formulation. The steps taken were preparing scallop shell flour, the calcination processed with temperatures of 700, 800, and 900°C and times 6; 4.5; and 3 hours, and the synthesis processed using Ammonium Dihydrogen Phosphate (ADP). The results obtained were the best hydroxyapatite treatment at a calcination temperature of 800°C for 4.5 hours with a yield of 75.20%. The functional group found of CO32- indicated C-O vibrations from the CO3 group and the hydrogen phosphate group (HPO42-). The diffractogram of HAp was similar to standard hydroxyapatite (HAp-S) with high intensity at values of 2θ: 25,88°; 31.75°; 32.18°; 32.88°; 34.05°; 39.77°; 46.61°; and 49.97°. HAp from this study has an agglomerate morphology, without sharp surface and edges. Based on SEM-EDS analysis, the HAp contains Ca and P 59.09 and 40.91%, respectively, with a Ca/P ratio of 1.44. The average particle diameter size was 396.88 nm. The morphology of the resulting HAp will be safe for human soft tissue application.

Copyright of Duzce University Journal of Science & Technology is the property of Duzce University Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tulang ikan Baung memiliki komposisi kalsium sebesar 30,93% dengan rendemen sebesar 27,77%. Hidroksiapatit merupakan material yang banyak diaplikasikan secara luas untuk regenerasi tulang, implan tulang dan gigi, serta ortopedi. Penelitian ini bertujuan untuk mengetahui pengaruh waktu kalsinasi tulang ikan Baung menggunakan instrumen XRD dan FTIR. Instrumen XRD digunakan untuk mengetahui karakteristik fisika dan FTIR digunakan untuk mengetahui karakteristik kimia. Pada penelitian ini menggunakan metode sol-gel, karena mampu meningkatkan kristalinitas dari HAp dan mengatur komposisi, menghasilkan lapisan homogen, efektif dan murni bagi sintesis hidroksiapatit dalam fasa nano. Rendemen yang diperoleh pada proses kalsinasi sebesar 61,8%, 58,5% dan 62%. Hidroksiapatit yang diperoleh kemudian dikaraterisasi kimia menggunakan instrumen FTIR menunjukkan adanya gugus fungsi PO43- dan CO32- Sedangkan instrumen XRD menunjukkan fasa hidroksiapatit dan fasa pirofosfat Hidroksiapatit dikarakterisasi secara fisika memperoleh derajat kristanilitas sebesar 85,6%, 63,45%, dan 74,24%.

Copyright of Karaelmas Science & Engineering Journal / Karaelmas Fen ve Mühendislik Dergisi is the property of Karaelmas Science & Engineering Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Balai Besar Keramik (BBK) telah berhasil mensintesis hidroksiapatit (HA) dari sumber daya alam Indonesia yaitu batu kapur Padalarang dan Cirebon dengan metode presipitasi basah. Berbagai aplikasi yang dapat menggunakan hidroksiapatit sintetik ini antara lain: bone china, kandidat bone grafting, tulang cacat femoralis cavia cobaya, implan tulang berbahan komposit Al-HA dan material karbonat hidroksiapatit. HA merupakan bahan yang non fotokatalitik oleh karena itu tidak akan menimbulkan munculnya radikal bebas. Studi ini meneliti aplikasi dan sifat hidroksiapatit BBK sintetis sebagai bahan filter tabir surya baru. Kristalinitas, ukuran kristal dan mineralogi HA sintetik dikarakterisasi dengan XRD. Kemampuan dalam menyerap radiasi sinar UV dianalisis dengan UV-Vis kemudian nilai faktor SPF dihitung secara in vitro menggunakan persamaan Mansur. Dari hasil analisis UV-Vis menunjukkan bahwa hidroksiapatit sintetis BBK memiliki absorbsi pada panjang gelombang 280-410 nm. Dari perhitungan didapatkan nilai SPF sebesar 8,82.

It is known that hydroxyapatite is similar to the inorganic structure of bones and teeth. However, the use of pure HA in bone-tooth implants is limited because it has low mechanical properties. To overcome this problem, composites can be formed with various bio-ceramics. In this study, it was aimed to produce a new biocompatible composite material with high mechanical strength by adding different amounts of graphene and a constant amount of Si3N4 to HA. 5 different Hydroxyapatite-Silicon Nitride-Graphene bio composites with different reinforcement ratios were turned into pellets with the help of a single-axis press and sintered at 1 100 °C for 2 hours to gain final strength. The densities of the samples were determined according to the Archimedes principle, the microstructure was analysed by scanning electron microscopy (SEM) and the formed phases were determined by XRD analysis. In addition, the hardness of the samples was measured with Microvickers. As a result of the studies, it was determined that the hardness and density values increased by adding graphene and Si3N4 to HA. In addition, mechanisms that increase fracture toughness were observed in SEM images. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Advanced Research in Health Sciences (JARHS) / Sağlık Bilimlerinde İleri Araştırmalar Dergisi (SABİAD) is the property of Journal of Advanced Research in Health Sciences (JARHS) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rajungan (Portunus pelagicus) merupakan salah satu hewan laut yang banyak terdapat di perairan Indonesia. Limbah cangkang rajungan memiliki kadar protein (32,95%), serat kasar (10,89%), kalsium (22,93%), dan fosfor (0,78%). Kandungan kalsium yang tinggi membuat cangkang rajungan dapat diolah untuk mendapatkan senyawa hidroksiapatit, yang bisa dipergunakan untuk pupuk lepas lambat. Sebelum dikonversi menjadi senyawa hidroksiapatit, diperlukan proses pengecilan ukuran atau penepungan dari cangkang rajungan. Proses penepungan dapat dilakukan menggunakan Ball-Mill, tetapi belum ada penelitian secara khusus yang membahas tentang mekanisme penepungan cangkang rajungan menggunakan Ball-Mill. Tujuan dari penelitian ini adalah untuk menentukan parameter penggilingan dari model kinetik pada penggilingan cangkang rajungan sehingga didapatkan prediksi pengecilan ukuran partikel tepung cangkang rajungan. Dalam penelitian ini, Ball-Mill tipe batch digunakan untuk menggiling 1,5 kg cangkang rajungan kering dengan rasio diameter bola yang berbeda. Estimasi parameter pemecahan dilakukan menggunakan model algoritma penghitungan balik, dengan estimasi parameter pemecahan secara berurutan ɑ; α; δ; γ; 𜙠= 1,1 ; 1,9 ; 1000 ; 0,5 ; 0,6 pada perlakuan A, dan α; δ; γ; 𜙠adalah 8,8 ; 6,4 ; 1000 ; 0,6 ; 8,8 pada perlakuan B. Dengan menggunakan parameter tersebut dapat disimulasikan antara lama waktu penggilingan dengan ukuran partikel yang dihasilkan.

Pendahuluan: Resin akrilik heat cured (HC) merupakan pilihan utama bahan sebagai basis gigi tiruan. Hidroksiapatit (HAP) adalah molekul kristalin yang sudah banyak digunakan di kedokteran gigi. Penelitian terdahulu membuktikan bahwa HAP mampu mengurangi monomer sisa pada resin akrilik HC, yang akan mengurangi juga porositas resin akrilik tersebut. Berkurangnya porositas resin akrilik, diharapkan akan meningkatkan kekuatan mekanik resin akrilik tersebut. Tujuan penelitian menganalisis pengaruh penambahan hidroksiapatit terhadap porositas dan compressive strength resin akrilik HC. Metode: Jenis penelitian eksperimental laboratoris. Sampel penelitian 20 resin akrilik HC berbentuk silindris (6x3mm), dibagi menjadi 4 kelompok. Kelompok kontrol (tanpa penambahan HAP), kelompok HAP 2%, kelompok HAP 5%, dan kelompok HAP 10%. Permukaan sampel diteliti menggunakan SEM untuk porositasnya. Penghitungan compressive strength sampel menggunakan Universal Testing Machine (load cell 300kg/mm2). Hasil: Uji one-way ANOVA dan Tukey-HSD menunjukkan perbedaan signifikan (p

Researches on improving osseointegration which is defined as a direct bond formation between living bone and implant and reducing bacterial growth on the material, are still among the studies that engage scientists' attention. While hydroxyapatite coating is one of the most widely used approaches to increase osseointegration, methods used to reduce bacterial growth vary. One of these methods is to form a copper-doped hydroxyapatite layer on the implant, which is known to be antibacterial. In this study, a copper oxide-containing hydroxyapatite thin film layer (HA/CuO) was formed on the surface of 316L stainless steel by using pulsed laser deposition (PLD). Dry sliding wear behaviour and corrosion behaviour of untreated and coated samples were comparatively investigated in phosphate buffer saline (PBS) and simulated body fluid (SBF) after coating. Structural characterizations were examined with scanning electron microscope (SEM), X-ray diffraction (XRD) and 3D profilometer. [ABSTRACT FROM AUTHOR]

This paper describes an optimization procedure for the adsorption of arsenite ions from wastewater using the Adaptive Neuro-Fuzzy Inference System (ANFIS). The adsorbent is based on hydroxy apatite, a natural material obtained from carp (Cyprinus carpio) scales. The input parameters were the influence of pH, the temperature, the initial concentration and reaction time of arsenite adsorption while the adsorption capacity and the arsenite removal percentage were studied as the output parameters. / В данной статье описана процедура оптимизации адсорбции ионов арсенита из сточных вод с использованием адаптивной нейронечеткой логической системы (ANFIS). В основе адсорбента лежит природный гидроксиапатитный материал, полученный из чешуи карпа (Cyprinus carpio). В качестве параметров ввода использовались влияние pH, температуры, начальной концентрации и времени реакции на адсорбцию арсенита, а в качестве выходных параметров были исследованы адсорбционная емкость и процент удаления арсенита. / U radu se opisuje postupak optimizacije adsorpcije arsenitnih jona iz otpadnih voda korišćenjem adaptivnog neuro-fazi sistema (ANFIS). U osnovi adsorbenta nalazi se prirodni hidroksi-apatitni materijal dobijen iz krljušti šarana (Cyprinus carpio). Kao ulazni parametri korišćeni su uticaj pH, temperature, početne koncentracije i vremena adsorpcije arsenita, a kao izlazni parametri ispitivani su adsorpcioni kapacitet i procenat uklanjanja arsenita.

Inženjerstvo koštanog tkiva brzorastuće je polje istraživanja usmjereno na razvoj bioaktivnih 3D poroznih nosača, kao privremenih izvanstaničnih matrica, koji podržavaju prianjanje, umnažanje i diferencijaciju stanica te potiču stvaranje koštanog tkiva in vivo. Više od deset godina istraživanja naše grupe posvećena su razvoju novih materijala i postupaka za pripravu 3D poroznih nosača za inženjerstvo koštanog tkiva. Kao mogući nosači istraživani su porozni skeleti morskih organizama te kompozitni materijali i hidrogelovi na temelju biorazgradljivih polimera i bioresorbirajuće hidroksiapatitne keramike. U ovom radu dan je prikaz naših istraživanja i glavnih postignuća, objavljenih u međunarodnim znanstvenim publikacijama.

Elektriksel Kıvılcımla İşleme (EKİ), özellikle çok sert ve karmaşık şekilli malzemelerin işlenmesinde tercih edilen alışılmamış imalat yöntemidir. Toz Katkılı Elektriksel Kıvılcımla İşleme (TKEKİ) yönteminde ise dielektrik sıvıya katılan toz partikülleri ile işlem performansının artırılması amaçlanmıştır. Bu amaçla, silisyum karbür (SiC), bakır (Cu), alüminyum (Al), demir (Fe) ve karbon (C) gibi birçok toz katkısı kullanılmaktadır. Hidroksiapatit (HA) genellikle kemiklerde dolgu malzemesi olarak ya da implantları desteklemek amacıyla kullanılan biouyumlu seramiktir. Bunun yanında, Titanyum (Ti) ve titanyum alaşımları da sahip olduğu mekanik özellikleri ve korozyon direnci nedeniyle medikal uygulamalarda sıkça tercih edilmektedir. Bu çalışmada, mikronize HA toz katkılı EKİ yöntemiyle işlenmiş Ti-6Al-4V alaşımının yüzey özellikleri ve işleme sırasında yüzeye toz katkısı nüfuziyeti incelenmiştir. Numuneler, 4 farklı akım seviyesinde ve her bir akım seviyesi için 10 farklı darbe süresi uygulanarak işlenmiştir. İşlenen numuneler, Taramalı Elektron Mikroskopu (SEM), Enerji Dağılım Spektrometresi (EDS), X-Işını Kırınım Difraktometresi (XRD) ve Optik Mikroskop ile incelenmiştir. Yüzeyde HA yönünden zengin oluşumlar gözlemlenmiş ve bu oluşumların gözlemlendiği parametreler tespit edilmiştir. Buna göre en iyi nüfuziyetin 22 A darbe akımı ve 100 µs ve 800 µs darbe sürelerinde gerçekleştiği gözlemlenmiştir. Tıbbi uygulamalar için HA bakımından zengin fonksiyonel yüzeyler talep edilmektedir. Ayrıca bu yüzeylerin TKEKİ yöntemiyle elde edilmesi yenilikçi bir yaklaşımdır.

In this study, the capability of chemically synthesized hydroxyapatitemagnetite (HAp/Fe3O4-MHAp) nanocomposite for the sorption of Zn(II) ions was investigated. Magnetite-hydroxyapatite nanocomposite (MHAp) has been chosen as an adsorbent because of its excellent properties such as stability, low cost and effective sorption power. Adsorption process were tried to find the optimum conditions of the parameters for Zn(II) removal such as pH, concentrations of initial Zn(II) and adsorbent and reaction time. Nanocomposite properties were also characterized by using Fouirer Transform Infrared Spektrofotometre (FTIR), Scanning Electron Microscope (SEM) and Energy-dispersive X-ray Spectroscopy (EDX) techniques. Our results showed that the adsorption kinetic of Zn(II) using HAp/Fe3O4 composite fitted to the pseudo-second-order kinetic model. Calculations were carried out to determine which isotherm model the adsorption fits by using Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich (D-R) equations. Adsorption potential of MHAp nanocomposite was obtained 555.55 mg/g, and best removal value of 96% were determined at pH of 6.0, optimum adsorbent concentration of 6.25 g/L, in 25 mg/L Zn(II) concentration and optimum mixing time of 30 min. This study showed that the MHAp can be considered an effective adsorbent on the Zn(II) removal from wastewater. [ABSTRACT FROM AUTHOR]

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In this study, hydroxyapatite material was prepared for the removal of Remazol N.Blue RGB (RB203) from waters. In the synthesis of hydroxyapatite material, waste hen's eggshell was evaluated as calcium source. Synthesis of hydroxyapatites was performed at three different pH values (pH 9, 10 and 11) using precipitation method. Before and after calcination of eggshells, XRF, XRD and SEM analysis were carried out. Synthesized hydroxyapatites were characterized by TGA-DTA, XRD and FTIR analysis. At the end of the characterization studies, hydroxyapatite structure was obtained better in pH 10 medium, and adsorption studies were carried out with the material prepared at this pH value. The effects of pH (2-12), amount of sorbent (2-10 g/L) and concentration of dye (25-200 mg/L) on adsorption of RB203 using hydroxyapatite were examined. In order to determine the mechanism of adsorption, the Langmuir, Freundlich, Temkin and Henry isoterm equations were used. Comparing the adsorption isotherms in terms of correlation coefficients (R2), it was seen that the Langmuir, Freundlich and Temkin isotherm models were in good agreement with the experimental data. The highest adsorption capacity obtained with the Langmuir isotherm model was 27.93 mg/g. In order to examine the adsorption kinetics, the pseudo-first and the second order kinetic equations were used. The results of adsorption kinetics show that the adsorption of RB203 with hydroxyapatite was better expressed by the pseudo-second order kinetic equation. This study shows that the hydroxyapatite synthesized from waste calcined eggshell is a promising sorbent for adsorption of dye. [ABSTRACT FROM AUTHOR]

Sintesis coralline hydroxyapatite (CHAp) dari koral laut yang umumnya menggunakan metode basah yaitu hidrotermal yang memerlukan suhu dan tekanan tinggi. Tujuan dari penelitian ini adalah mengkonversi koral laut Goniopora sp. menjadi CHAp dengan metode sonikasi pada suhu rendah. Goniopora sp. dikalsinasi pada suhu 900 °C selama 3 jam, kemudian direaksikan dengan diammonium hidrogen fosfat [(NH4)2HPO4] dan mono kalium fosfat (KH2PO4) dengan waktu sonikasi 6 jam sampai 24 jam pada suhu 60 °C. Hasil penelitian menunjukkan bahwa telah terjadi perubahan fase dari koral menjadi CHAp yang dapat dilihat dari identifikasi pola difraksi sinar-X khas dari hidroksiapatit dengan derajat kristalinitas sebesar 66% untuk CHAp dengan waktu sonikasi 24 jam. Spektrum Fourier Transform Infra Red Spectroscopy (FTIR) menunjukkan puncak serapan khas dari hidroksiapatit yaitu gugus OH pada 3637 cm-1 sampai dengan 3404 cm-1 fosfat (PO43-) pada 569 cm-1, 603 cm-1, 960 cm-1, dan 1045 cm-1 serta karbonat (CO32-) pada 1456 cm-1 dan 873 cm-1. Carbonated hydroxyapatite yang terbentuk adalah tipe-B. Rasio Ca/P yang dihasilkan untuk CHAp dengan waktu sonikasi 24 jam adalah 1,7.

Bone tissue engineering (BTE) is a fast growing field focused on the development of bioactive 3D porous scaffolds as temporary extracellular matrices that support cell attachment, proliferation and differentiation, and stimulate bone tissue formation in vivo. Over more than ten years, our group has been devoted to developing new biomaterials and methods to prepare 3D porous scaffolds for BTE applications. The potential of natural porous structures such as marine skeletons, composite materials, and hydrogels based on biodegradable polymers and bioresorbable hydroxyapatite ceramics have been studied. In this paper, an overview of our research and main achievements, published in international scientific publications, is provided. [ABSTRACT FROM AUTHOR]

Bu çalışmada amaç; biyomedikal uygulamalarda kullanılmak üzere mevcut biyomalzemelerden daha hafif, biyolojik saldırılara karşı dirençli ve kemik yapısına benzer, doku ile uyumlu bir malzeme üretebilmektir. Hafiflik biyomalzeme uygulamalarında son derece önemlidir, çünkü paslanmaz çelik ve bunun gibi ağır metalik alaşımlar vücutta kullanıldığında implant çevresindeki dokulara zarar vererek enfeksiyona sebep olabilmektedir. AZ91 Mg alaşımının hafifliği büyük bir avantaj olsa da vücutta kullanmak için yeterli mukavemete sahip değildir ve biyolojik ortamda bozunmaktadır. AZ91 Mg alaşım tozları 320 °C sıcaklık ve 275 MPa basınçta sıcak pres yöntemi ile preslendikten sonra, yeterli dayanımı sağlamak ve bozunmasını engellemek amacıyla sol-jel ve dip coating metoduyla yüzeyi farklı daldırma sayılarında hidroksiapatit ile kaplanmış ve 400 °C’de sinterlenmiştir. Kaplanan numunelerin yüzey morfolojileri SEM; faz yapıları ise XRD ile incelenmiştir.

Today marine-derived biologic scaffolds are popular due to their biocompatibility and high regenerative potential. Previous studies prepared hydroxyapatite from cuttlebone, the internal shell of cuttlefish; However, its biocompatibility and bioactivity has not been fully studied especially in-vivo. The aim of this study was to evaluate cuttlebone-derived hydroxyapatite in-vivo potential and possible synergistic effect of platelet rich plasma with this scaffold in promoting bone healing. Hydroxyapatite was prepared from cuttlebone (Sepia officinalis) via hydrothermal transformation. The conversion and microstructure of prepared material was assessed by scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis. Fifteen male white New Zealand rabbits were randomly divided to 6 groups each containing 5 limbs. In order to reduce sample size right and left pelvic limbs of rabbits were used as separate groups. Full thickness bi-cortical defects were created bilaterally in proximal tibia. The defect was left untreated in negative control group. In experimental group I to V the defect was filled with platelet rich plasma, raw cuttlebone, raw cuttlebone combined with platelet rich plasma, cuttlebone derived hydroxyapatite and cuttlebone derived hydroxyapatite combined with platelet rich plasma, respectively. Histopathological evaluation was performed on specimens received on day 56. Bone healing was assessed according to union, spongiosa, cortex and bone marrow indices. Our results demonstrated that Group I was superior to negative control group in defined indices. Groups IV and V showed preferable outcomes regarding to union and cortex indices in comparison to groups II and III. Also acceptable degree of spongiosa formation was observed in all groups. Cuttlebone derived hydroxyapatite could be an appropriate biomaterial to stimulate bone formation and enhance bone regeneration. Furthermore platelet rich plasma was successful in advancement of bone marrow formation. [ABSTRACT FROM AUTHOR]