Cangkang bekicot memiliki potensi sebagai bahan baku sintesis kalsium fosfat karena kandungan kalsium yang sangat tinggi, yaitu sekitar 99 %. Kalsium fosfat dapat diaplikasikan sebagai biomaterial ...karena sifatnya yang sama dengan jaringan penyusun tulang. Pada saat ini kebutuhan akan biomaterial sangat tinggi dan telah memberi dampak yang cukup besar terutama dalam bidang kedokteran ortopedi. Penelitian ini bertujuan untuk mengkaji karakteristik kalsium fosfat dengan menggunakan bahan baku cangkang bekicot. Penelitian ini dilakukan dengan metode presipitasi dengan variasi pH dan suhu sintering. Cangkang bekicot di kalsinasi pada suhu 900 oC lalu di campurkan dengan larutan asam fosfat sesuai dengan rasio molar Ca/P 1,67. Pengendapan kalsium fosfat dilakukan saat proses presipitasi dengan penambahan NaOH untuk mengatur pH pada rentang 11 dan 12. Selanjutnya dilakukan proses sintering pada suhu 600, 700, 800, dan 900 oC. Karakterisasi kalsium fosfat yang dihasilkan menggunakan XRF, XRD, dan SEM. Hasil penelitian menunjukkan perolehan hidroksiapatit (Hap) mencapai 100% pada pH 12, dan suhu 600 oC dengan struktur kristal amorf.
Some biomaterials are osteoinductive, that is, they are able to trigger the osteogenic process by inducing the differentiation of mesenchymal stem cells to the osteogenic lineage. Although the ...underlying mechanism is still unclear, microporosity and specific surface area (SSA) have been identified as critical factors in material-associated osteoinduction. However, only sintered ceramics, which have a limited range of porosities and SSA, have been analyzed so far. In this work, we were able to extend these ranges to the nanoscale, through the foaming and 3D-printing of biomimetic calcium phosphates, thereby obtaining scaffolds with controlled micro- and nanoporosity and with tailored macropore architectures. Calcium-deficient hydroxyapatite (CDHA) scaffolds were evaluated after 6 and 12 weeks in an ectopic-implantation canine model and compared with two sintered ceramics, biphasic calcium phosphate and β-tricalcium phosphate. Only foams with spherical, concave macropores and not 3D-printed scaffolds with convex, prismatic macropores induced significant ectopic bone formation. Among them, biomimetic nanostructured CDHA produced the highest incidence of ectopic bone and accelerated bone formation when compared with conventional microstructured sintered calcium phosphates with the same macropore architecture. Moreover, they exhibited different bone formation patterns; in CDHA foams, the new ectopic bone progressively replaced the scaffold, whereas in sintered biphasic calcium phosphate scaffolds, bone was deposited on the surface of the material, progressively filling the pore space. In conclusion, this study demonstrates that the high reactivity of nanostructured biomimetic CDHA combined with a spherical, concave macroporosity allows the pushing of the osteoinduction potential beyond the limits of microstructured calcium phosphate ceramics.
Banyaknya limbah pelepah pisang di Indonesia yang tidak dimanfaatkan hanya akan menambah kuantitas limbah. Pelepah pisang memiliki kandungan kalium yang cukup besar dan dapat berfungsi sebagai bahan ...baku pupuk. Pembuatan pupuk kalium fosfat (K3PO4) dari abu pelepah pisang dan asam fosfat (H3PO4) adalah dengan cara ekstraksi. Abu dari hasil pembakaran pelepah pisang diekstraksi dengan asam fosfat. Penelitian ini bertujuan untuk menentukan kinetika reaksi yaitu konstanta kecepatan reaksi dan orde reaksi pembentukan kalium fosfat dari ekstrak abu pelepah pisang dan asam fosfat. Penelitian dilakukan dengan perbedaan suhu dan waktu. Suhu yang digunakan adalah 40, 50, 60, 70, dan 80 oC. Waktu ekstraksi berlangsung dalam variasi 10, 20, 30, 40, dan 50 menit. Berdasarkan penelitian yang telah dilakukan, pembentukan kalium fosfat dari abu pelepah pisang dan asam fosfat mengikuti orde satu dengan tetapan laju reaksi, k = 0,0151 menit-1 pada suhu 80oC. Energi aktivasi yang didapatkan adalah 170,8776 J/mol dengan nilai frekuensi tumbukan (k0) adalah 0,0163 persamaan tetapan laju reaksi k = 0,0163 e-20,533/T. Konversi terbaik yang didapatkan adalah 0,5698 atau 56,98 %.
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Calcium phosphate cements (CPC) have seen clinical success in many dental and orthopaedic applications in recent years. The properties of CPC essential for clinical success are ...reviewed in this article, which includes properties of the set cement (e.g. bioresorbability, biocompatibility, porosity and mechanical properties) and unset cement (e.g. setting time, cohesion, flow properties and ease of delivery to the surgical site). Emphasis is on the delivery of calcium phosphate (CaP) pastes and CPC, in particular the occurrence of separation of the liquid and solid components of the pastes and cements during injection; and established methods to reduce this phase separation. In addition a review of phase separation mechanisms observed during the extrusion of other biphasic paste systems and the theoretical models used to describe these mechanisms are discussed.
Occurrence of phase separation of calcium phosphate pastes and cements during injection limits their full exploitation as a bone substitute in minimally invasive surgical applications. Due to lack of theoretical understanding of the phase separation mechanism(s), optimisation of an injectable CPC that satisfies clinical requirements has proven difficult. However, phase separation of pastes during delivery has been the focus across several research fields. Therefore in addition to a review of methods to reduce phase separation of CPC and the associated constraints, a review of phase separation mechanisms observed during extrusion of other pastes and the theoretical models used to describe these mechanisms is presented. It is anticipated this review will benefit future attempts to develop injectable calcium phosphate based systems.
Urea intensive application is considered to reduce soil quality, and food quality. The constraints of urea application in tropics are low effectivity due to intensive leaching and volatilization. In ...order to decrease the urea dose, cheap and renewable biofertilizer application is suggested. Coating urea with biofertilizer become an easy way to apply both biofertilizer. In the previous research, biofertilizer-coated urea (BCU) had been formulated by using Bacillus subtilis, B. megaterium, Azotobacter chroococcum and A. vinelandii. The objective of this research was to verify the effect of BCU on the growth and yield of lettuce (Lactuca sativa L.) cv. Romaine; and decrease of urea dose in a planting season. The field experiment was arranged in randomized block design with five treatments and five replications. Lettuces were treated with a dose and half dose of two BCU formulations. The results showed that BCU didn’t affect growth, P uptake and plant yield but half dose of BCU produced the same lettuce productivity with one dose of urea. Half dose of BCU resulted in the same shoot N uptake as one dose of urea but a dose of particular BCU formulation possibly decreased N uptake. The population of total Bacillus and Azotobacter in the rhizosphere was determined by dose and BCU formulation but they didn’t change abruptly after BCU application. The experiment suggested that application of urea coated by carrier-based biofertilizer was reliable to support lettuce cultivation and reduce the urea dose.
Fenomena tanah supresif telah banyak dikaji sebagai metode pengendalian penyakit tanaman alami di lapangan dan dicirikan dengan banyaknya sejumlah mikrob fungsional yang mampu menekan populasi ...patogen. Penelitian ini bertujuan mengetahui dan membandingkan komposisi bakteri fungsional pada tanah supresif dan kondusif layu fusarium. Metode penelitian terdiri atas pengambilan sampel tanah di lapangan, isolasi bakteri fungsional dari sampel tanah supresif (TS) dan kondusif (TK), penghitungan populasi dan jenis bakteri, penapisan berdasarkan keamanan hayati, dan karakterisasi bakteri fungsional dalam menekan Fusarium oxysporum. Hasil penelitian menunjukkan bahwa populasi bakteri pada TS lebih tinggi dibandingkan TK, khususnya bakteri toleran panas dan Pseudomonas kelompok fluorescent. Hal ini didukung dengan tingginya nilai keanekaragaman bakteri fungsional pada TS (H’ 3.70 > 3) dibandingkan TK yang tergolong sedang (1 < H’ 2.07 < 3), dengan sebaran bakteri fungsional tergolong hampir merata dan tidak ditemukan adanya dominansi jenis tertentu pada TS maupun TK. Persentase bakteri nonpatogenik pada TS lebih tinggi dibandingkan TK, masing-masing 51% dan 23%. Bakteri tersebut berpotensi sebagai plant growth promoting bacteria (PGPB) dengan memproduksi IAA atau melarutkan fosfat saja, masing-masing 24% dan 10% pada TS, sedangkan pada TK masing-masing 14% dan 29%. Hanya bakteri yang berasal dari tanah supresif yang mampu memproduksi IAA sekaligus melarutkan fosfat dengan persentase sebanyak 48%.
Bu çalışma dikalsiyum fosfat (DCP) ve monokalsiyum fosfatın (MCP) broylerde linear regresyon metoduyla presekal fosfor sindirile bilirliğini belirlemek amacıyla gerçekleştirilmiştir. Denemede toplam ...360 adet bir günlük yaşta erkek broyler civciv (Ross 308) 21 günlük yaşa kadar standart ticari broyler başlangıç yemi (Metabolize olabilir enerji 3000 kcal/kg, ham protein %22, Ca %0,9 P %0,6) ile beslenmiştir. Broylerler 21 günlük yaşta her biri 6 tekerrürden oluşan ve her tekerrürde 12 civciv bulunan 5 deneme grubuna ayrılmıştır. Fosfor sindirile bilirliği belirlenecek DCP ve MCP bazal rasyona P düzeyini %0,075 ve %0,15 düzeylerinde artıracak oranda ilave edilmiştir. Markır olarak titanyum dioksit %0,5 düzeyinde kullanılmıştır. Denemenin 28. gününde fosfor sindirile bilirliğini belirlemek için bütün hayvanlardan ileum içeriği toplanmıştır. Linear regresyon metoduyla DCP ve MCP’nin presekal fosfor sindirile bilirlikleri sırasıyla %76,60 ve %85,83 olarak hesaplanmıştır. Bu çalışma sonucunda broyler rasyonları formüle edilirken rasyon maliyetini ve çevre kirliliğini artırmadan, optimum fosfor düzeylerinin ayarlanması için fosfor kaynaklarının sindirile bilirliklerinin bilinmesinin önemi vurgulanmıştır.
Tujuan dari penelitian ini adalah mendapatkan karakteristik fisikokimia gelatin dari kulit ikan ayam-ayam. Metode yang digunakan adalah eksperimen dengan menggunakan rancangan acak lengkap (RAL), ...dengan pra-perlakuan perendaman asam fosfat (konsentrasi: 0,2 M; 0,4 M; dan 0,6 M). Hasil penelitian ini didapatkan bahwa perbedaan pra-perlakuan pada ekstraksi gelatin dari kulit ikan ayam-ayam melalui perendaman asam fosfat dengan konsentrasi 0,2 M, 0,4 M, dan 0,6 M memberikan pengaruh nyata (P<0,05) pada nilai rendemen, viskositas, kekuatan gel, titik gel, titik lelehn dan kadar lemak gelatin kuli ikan ayam-ayam. Sebaliknya, pra-perlakuan ekstraksi GKA dengan konsentrasi asam sitrat yang berbeda tidak memberikan pengaruh nyata (P>0,05) terhadap nilai pH, kadar air, kadari protein, dan kadar abu dari gelatin kulit ikan ayam-ayam.
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There is an urgent need of synthetic bone grafts with enhanced osteogenic capacity. This can be achieved by combining biomaterials with exogenous growth factors, which however can ...have numerous undesired side effects, but also by tuning the intrinsic biomaterial properties. In a previous study, we showed the synergistic effect of nanostructure and pore architecture of biomimetic calcium deficient hydroxyapatite (CDHA) scaffolds in enhancing osteoinduction, i.e. fostering the differentiation of mesenchymal stem cells to bone forming cells. This was demonstrated by assessing bone formation after implanting the scaffolds intramuscularly. The present study goes one step forward, since it analyzes the effect of the geometrical features of the same CDHA scaffolds, obtained either by 3D-printing or by foaming, on the osteogenic potential and resorption behaviour in a bony environment. After 6 and 12 weeks of intraosseous implantation, both bone formation and material degradation had been drastically affected by the macropore architecture of the scaffolds. Whereas nanostructured CDHA was shown to be highly osteoconductive both in the robocast and foamed scaffolds, a superior osteogenic capacity was observed in the foamed scaffolds, which was associated with their higher intrinsic osteoinductive potential. Moreover, they showed a significantly higher cell-mediated degradation than the robocast constructs, with a simultaneous and progressive replacement of the scaffold by new bone. In conclusion, these results demonstrate that the control of macropore architecture is a crucial parameter in the design of synthetic bone grafts, which allows fostering both material degradation and new bone formation.
Statement of Significance
3D-printing technologies open new perspectives for the design of patient-specific bone grafts, since they allow customizing the external shape together with the internal architecture of implants. In this respect, it is important to design the appropriate pore geometry to maximize the bone healing capacity of these implants. The present study analyses the effect of pore architecture of nanostructured hydroxyapatite scaffolds, obtained either by 3D-printing or foaming, on the osteogenic potential and scaffold resorption in an in vivo model. While nanostructured hydroxyapatite showed excellent osteoconductive properties irrespective of pore geometry, we demonstrated that the spherical, concave macropores of foamed scaffolds significantly promoted both material resorption and bone regeneration compared to the 3D-printed scaffolds with orthogonal-patterned struts and therefore prismatic, convex macropores.
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.
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