Hidroksiapatit (HA) sangat berpotensi untuk digunakan dalam implantasi jaringan keras. Makalah ini memaparkan pelapisan HA pada substrat stainless steel 316 untuk meningkatkan sifat mekanis HA dengan ...menggunakan metode deposisi elektroforesis. Pengaruh tiga parameter yaitu variasi waktu deposisi (15 menit dan 60 menit), kehalusan permukaan (600 grit dan 1200 grit), dan suhu sintering (800 oC, 900 oC, 1000 oC, dan 1200 oC) terhadap lapisan HA diamati. Hasil penelitian menunjukkan bahwa pelapisan HA pada substrat SS 316 lebih tebal pada waktu deposit 60 menit, dengan hasil padat dan homogen didapatkan pada kondisi permukaan substrat yang telah diamplas dengan kertas silikon karbida 1200 grit dan suhu sintering 900 oC.
Svrha: Željela se istražiti stabilnost implantata nakon podizanja dna sinusa i primjene dvaju nadomjesnih materijala te dobivene rezultate usporediti s implantatima postavljenima u neaugmentirani ...lateralni dio gornje čeljusti. Materijali i metode: Istraživanje je provedeno na 44 zdrava pacijenta s indikacijom za podizanje dna sinusa (ispitivana skupina). Nakon podizanja dna sinusa i primjene čistog beta trikalcijeva fosfata postavljeno je 46 implantata, a 39 je ugrađeno nakon augmentacije sa 60-postotnim hidroksiapatitom i 40-postotnim beta trikalcijevim fosfatom. U kontrolnoj skupini bilo je 48 zdravih pacijenata kojima je 85 implantata postavljeno u neaugmentirani
lateralni dio gornje čeljusti. Svim ispitanicima ugrađeni su implantati Astra Tech OsseoSpeed. Njihova stabilnost određivala se metodom analize rezonantne frekvencije. Na temelju triju mjerenja izračunat je kvocijent stabilnosti implantata (ISQ). Rezultati: Nije pronađena statistički značajna razlika u ISQ-vrijednosti između implantata koji su postavljeni augmentacijskim postupkom i onih bez njega (p=0,789). Statistički značajna razlika nije uočena ni kada su ISQ-vrijednosti implantata postavljenih nakon pojedinog nadomjesnog materijala uspoređene s ISQ-vrijednostima odgovarajućih implantata u neaugmentiranoj kosti (p=0,697 i p=0,402). Zaključak: Ovo istraživanje pokazalo je da je stabilnost implantata usporediva između implantata koji su postavljeni u lateralni dio gornje čeljusti, neovisno o podizanju dna sinusa i nadomjesnom materijalu. Implantati ugrađeni u augmentirani lateralni dio gornje čeljusti mogu se predvidivo protetski opskrbiti kao i implantati postavljeni u neaugmentiranu gornju čeljust.
Background: The filler addition to resin based sealers will enhance the physical properties of the polymer. Because of its biological properties, the synthetic hydroxyapatite (HA) has been proposed ...as filler for dental material such as composite resin. The calcite synthesized HA is the HA produced of calcite minerals that came from many Indonesian mining. Purpose: The aim of study was to determine the effect of different concentration of calcite synthesized HA as the filler of the epoxy-resin-based root canal sealer on the physical properties such as its contact angle, the film thickness and the microhardness. Methods: The crystal of the calcite synthesized hydroxyapatite with the size between 77.721-88.710 nm and the ratio of Ca/P 1.6886 were synthesized at Ceramic Laboratory, Mechanical Engineering, using wet method of hydrothermal microwave. The powders of the epoxy- resin were prepared by added the synthesized hydroxyapatite crystal in 5 different weight ratios (e.g.: HA-10%, HA-20%, HA-30%, HA-40% and HA-50%). Each of these was mixed with the paste of 3:1 ratio using spatula on a glass plate until homogen and then measuring the contact angle and the film thickness. Microhardness test was conducted after the mixture of experimental sealer was stored for 24 hrs at 37 oC to reach perfect polymerization. Results: All of contact angles were <90o and were not significantly different to each other (p= 0.510). All groups had a film thickness in accordance with ISO 6876 (<50 um) and with no statistical difference (p= 0.858). In the HA of 10%, 20%, 30% seen that the microhardness were increased, while in the HA-50% was decreased and in the HA-40% has the same microhardness to the control groups (HA-0%). Conclusion: Calcite synthesized HA as the filler did not affect contact angle and film thickness of the sealer. Microhardness of the epoxy-resin based sealer could be increased using maximum 30% of the calcite synthesized HA as the filler. Latar belakang: Penambahan bahan pengisi pada sealer berbahan dasar resin akan meningkatkan sifat fisik polimer. Karena sifat biologis bagus, hidroksiapatit (HA) sintetis digunakan sebagai bahan pengisi material kedokteran gigi seperti resin komposit. Hidroksiapatit sintesis kalsit merupakan HA yang hasilkan dari mineral kalsit berasal dari berbagai daerah pertambangan di Indonesia. Tujuan: Penelitian ini bertujuan untuk meneliti pengaruh berbagai konsentrasi HA sintesis kalsit sebagai bahan pengisi sealer berbahan dasar resin epoksi terhadap sifat fisiknya yaitu sudut kontak, ketebalan film dan kekerasan mikronya. Metode: Kristal HA sintesis kalsit yang berukuran 7,721-88,710 nm dengan rasio Ca/P 1,6886 diperoleh dari sintesis di Laboratorium Keramik, Teknik Mesin, Universitas Gadjah Mada menggunakan wet method dengan microwave hidrotermal. Serbuk resin epoksi dipersiapkan dengan menambahkan kristal HA sintesis kalsit dalam lima konsentrasi yang berbeda yaitu HA-10%, HA-20%, HA-30%, HA-40% dan HA-50% (dalam berat). Masing-masing serbuk diaduk dengan pasta resin epoksi dengan perbandingan 3:1 menggunakan spatula di atas glassplate hingga homogen, selanjutnya dilakukan pengukuran sudut kontak dan ketebalan film. Pengukuran kekerasan mikro dilakukan setelah sealer disimpan dalam inkubator 37 oC selama 24 jam sehingga mencapai polimerisasi sempurna. Hasil: Semua kelompok menunjukkan bahwa sudut kontak <90o dan menunjukkan tidak ada perbedaan yang signifikan (p=0,510). Semua kelompok menunjukkan bahwa ketebalan filmnya sesuai dengan ISO 6876 (<50 um) dan menunjukkan tidak ada perbedaan yang signifikan (p=0,858). Pada kelompok HA-10%, 20% dan 30% kekerasan mikronya meningkat, sedangkan pada HA-50% menurun dan HA-40% kekerasannya sama dengan kelompok kontrol (HA-0%). Simpulan: Penambahan hingga 50% HA sintesis kalsit sebagai bahan pengisi sealer resin epoksi tidak mempengaruhi sudut kontak dan ketebalan film. Kekerasan sealer dapat ditingkatkan dengan menambahkan HA sintesis kalsit maksimum hingga 30%.
Amaç: NaOH konsantrasyonu ve bekletme süresinin ağırlıkça % 19 kalsine edilmemiș karbonlanmıș hidroksiapatit (CHA)/Poly-ε -kaprolakton (PCL)’nin kütle kaybına etkisinin incelenmesi
Aim: To study the ...effect of NaOH concentration and duration of treatment on the % mass loss of 19 wt% uncalcined carbonated hydroxyapatite (CHA)/Poly-ε -caprolactone (PCL)
Provider: - Institution: - Data provided by Europeana Collections- During recent decades, a great attention has been focused on research and development of biomaterials that are exploited to replace ...missing body structures, to enhance functions of existing ones or promote the new tissue formation. The clinical success outcome of biomaterial used in tissue engineering applications depends critically upon physical and chemical properties of tested materials. The synthetic materials, capable of supporting the natural process of bone re-modeling, include the ex vivo generation of cell-scaffold complexes, in vivo resorbable bone cements, coatings that enhance the bonding between natural bone and implant, various forms of implantable prostheses, bone-repair agents etc. Synthetic bioactive ceramics such as certain forms of calcium-phosphate (hydroxyapatite: HA; α-tricalcium phosphate: α-TCP; β-tricalcium phosphate: β-TCP) and combinations of them have been widely studied due to their structural and chemical similarity with the inorganic components of natural bone. One of the most important stages of bone tissue engineering is to design and process scaffold materials aiming to, as high as possible, the in-growth of blood vessels, and to guide the growth of bone in a natural manner mimicking the structure of human compact bone. During the first decade of the twenty-first century third-generation of biomaterials has been designed to stimulate specific cellular responses at the level of molecular biology. Certain formulations of bioactive materials such as bioactive glasses release chemicals in the form of ionic dissolution products, or governing macromolecular growth factors, which at controlled rates, activate the cell functions. The goal of the thesis was to develop three-dimensional scaffolds based on silicon doped HA/α-TCP specifically designed for application in bone tissue engineering where, through controlled release rate of Si, Ca and P, one assure optimal influence at the biological response of material and invoke enhanced cell adhesion, differentiation and gene expression. Therefore, for scaffolds preparations silicon doped and un-doped HA particles were synthesized having different morphologies (spherical and whisker-like) using hydrothermal method. Appropriate quantities of the reactants Ca(NO3)2•4H2O, (NH4)2HPO4•2H2O, Na2EDTA (the last one being used for synthesis of spherical-like particles) and urea were used to prepare stoichiometric hydroxyapatite (Ca/P = 1.67) and hydroxyapatite of Ca/P molar ratio that approaches 1.50. The silicon-substituted apatites were prepared using a Ca/P molar ratio approaching 1.50 by adding two different quantities of tetraethyl orthosilicate (TEOS) as the source of silicon ions. Lower Ca/P ratio and doping with silicon were used in order to enhance formation of silicon-stabilized α-TCP and improve the bioactivity when compared to pure hydroxyapatite. The influence of silicon substitution level in spherical-and whisker-like particles on the morphology, phase transformations and bioactivity of the obtained powders and scaffolds based on these particles was investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive x-ray fluorescence spectroscopy (EDXRF), Fourier transform infrared (FTIR) spectroscopy and in in vitro test performed on SaOs2, L929 and MRC-5 cells. The investigations showed different degree of silicon substitution under the same synthesis conditions on spherical- and whisker-like particles revealed by XRD and EDXRF analyses, where higher content of added silicon enhanced phase transformation from HA to a-TCP at lower temperatures. These transformations are more pronounced on spherical particles. Although, there is no significant difference in phase composition between un-doped and material doped with silicon at low concentration after heating at high temperature, it was observed that samples doped with less amount of silicon (0.55 wt% for spherical and 0.58 wt% for whisker-like powder particles) exhibit higher in vitro bioactivity on SaOs2 cells than silicon-free hydroxyapatite. Annealing of the spherical and whiskers-like particles at 1200 °C reduced cytotoxicity of the extracts on both SaOs2 and L929 cells. The SEM and XRD analysis confirmed that spherical particles doped with controlled amount of silicon transformed from HA into α-TCP by annealing at 1150 °C retaining thereby the spherical morphology of the particles. Due to this synthesis procedure, spherical α-TCP particles with a uniform size distribution could be obtained without milling that is the irrefutable process for α-TCP particles preparation obtained by other methods. In this work three different techniques were used for scaffolds preparation. Scaffolds were prepared using silicon doped spherical- and whisker-like α-TCP particles pretreated at 1200 °C that were milled and mixed with 30 % H2O2 solution and polimethyl-metacrilate (PMMA) fibers, where PMMA have a function to form the interconnected porosity. After a setting time scaffolds with adequate micro- and macro-porous structure were obtained, where further annealing at higher temperatures were required to eliminate captivated PMMA fibers. When scaffolds have been obtained by mixing with H2O2 solutions, further annealing after the setting time was avoided. The scaffolds obtained by replica foam method using silicon doped spherical particles preheated at 1150 °C had a uniform and interconnected porous structure and compressive strength up to 5.7 MPa after sintering at 1450 °C. In vitro test, high proliferation activity of human fibroblast cells MRC-5 seeded on the scaffolds was confirmed. The results achieved in this thesis contribute to a better understanding of technological aspects of synthesis of common used scaffold materials based on calcium-phosphates. Furthermore, a number of different materials synthesized in forms of HA/α-TCP powders or scaffolds, properly characterized and thoroughly discussed, might be considered as attractive alternatives to gain appropriate knowledge for productions, within short to medium-term time span, creating innovative HA/α-TCP biomaterials of highest potential for bone defects healing.- Poslednjih nekoliko decenija, velika pažnja usmerena je na razvoj biomaterijala koji bi imali potencijal da reparišu ili zamene oštećenenih delova koštanog tkiva, pospeše funkcionisanje postojećeg ili ubrzaju stvaranje novog tkiva. Klinička primenana biomaterijala zavisi pre svega od fizičkih i hemijskih svojstava materijala. U savremene sintetičke biomaterijale se ubrajaju ex vivo ćelijama zasejani skafoldi, in vivo resorbilni koštani cementi, prevlake koje pospešuju stvaranje veze između prirodne kosti i implanta, različite forme implantnih proteza i dr. Bioaktivna keramika na bazi kalcijum-fosfata (hidroksiapatit: HA; α-kalcijum-fosfat: α-TCP; β-kalcijum-fosfata; β-(TCP) zauzima značajno mesto zbog strukturne i hemijske sličnosti sa neorganskom komponentom prirodne kosti. Jedno od najvažniji područja inženjerstva koštanog tkiva pretstavlja dizajniranje i procesiranje skafoldnih materijala po strukturi sličim kostima koji bi omogućili vaskularizaciju i urastanje koštanog tkiva. Tokom prve dekade 21. veka velika pažnja je usmerena na razvoj treće generacije bioaktivnih materijala koji bi stimulisali specifičan ćelijski odgovor. Značajnu grupa biomaterija čine materijali na bazi bioaktivnog stakla koji otpuštanjem jona u rastvoru stimulišu faktore rasta koji na kontrolisan način aktiviraju ćelijske funkcije. Cilj ove teze pretstavlja razvoj skafolda na bazi silicijumom dopiranih α-kalcijum-fosfata i hidroksiapatita za supstituciju i reparaciju koštanog tkiva koji bi kontrolisanim otpuštanjem jona silicijuma i kalcijuma i fosfatnih jona povoljno uticali na adheziju i diferencijaciju ćelija i gensku ekspresiju. U tom cilju sa procesiranje skafolda hidrotermalnim postupkom sintetisane su nedopirane i silicijumom dopirane čestice HA različite morfologije (sferne i vlaknaste). Kao polazna jedinjenja za sintezu stehiometrijskog hidroksiapatita (Ca/P = 1,67) i hidroksiapatita sa odnosom Ca/P = 1,50 korišćeni su Ca(NO3)2•4H2O, (NH4)2HPO4•2H2O, Na2EDTA (poslednje jedinjenje je korišćeno za sintezu sfernih čestica) i urea. Silicijumom dopirani hidroksiapatiti su sintetisani za odnos Ca/P = 1,50 korišćenjem tetraetil-ortosilikata (TEOS) kao izvora silicijumovih jona. Dopiranje silicijumom pri odnosu Ca/P = 1,50 je izvšeno u cilju favorizovanja formiranja silicijumom stabilisanog α-TCP i poboljšanja bioaktivnih svojstava u odnosu na stehiometrijski hidroksiapatit. Uticaj stepena supstitucije silicijumom na morfologiju, faznu transformaciju i bioaktivnost sintetisanih sfernih i vlaknastih čestica, kao i skafolda dobijenih od nedopiranih i silicijumom dopiranih čestica analiziran je rendgenskom difrakcijom (XRD), skenirajućom elektronskom mikroskopijom (SEM), transmisionom elektronskom mikroskopijom (TEM), visokorezolucionom transmisionom elektronskom mikroskopijom (HRTEM), energetskom disperzionom rendgenskom fluorescentnom spektroskopijom (EDXRF), infracrvenom spektroskopijom (IC) i u in vitro testovima u kulturi SaOs2, L929 i MRC-5 ćelija. XRD i EDXRF analiza je pokazala različiti nivo supstitucije silicijumom pri istim uslovima sinteze na sfernim i vlaknastim česticama. Takođe, utvrđeno je da dopiranje silicijumom dovodi do snižavanja temperature fazne transformacije HA u α-TCP. Ovaj efekat je izraženiji kod silicijumom dopiranih čestica HA sferne morfologije. Iako nema značajnije razlike u faznom sastavu između nedopiranih i silicijumom dopiranih u malom procentu prahova HA nakon termičkog tretmana na višim temperaturama, primećeno je da su prahovi dopirani silicijumom u manjem procentu (0,55 mas. % za sferne i 0,58 mas. % za vlaknaste čestice) bioaktivniji u kulturi SaOs2 ćelija u poređenju sa nedopi
Temporomandibular joint prosthesis serta berbagai macam bentuk dan material sudah cukup banyak diteliti. Namun, sejauh yang penulis teliti, belum ada yang menggunakan Hidroksiapatit (HA) sebagai ...material utama. Penelitian ini bertujuan untuk mengetahui laju keausan dari material komposit hidroksiapatit (HA) + polymethyl methacrylate (PMMA) serta mekanisme keausan yang terjadi pada permukaannya untuk aplikasi prosthesis. Pengujian keausan dilakukan menggunakan tribometer pin-on-disc dengan material komposit sebagai spesimen pin dan ultra high molecular weight polyethylene sebagai material disc. Variasi yang dilakukan adalah variasi kandungan hidroksiapatit pada material komposit yaitu sebesar 40%, 50%, 60% dan 70%. Pengujian keausan dilakukan pada keadaan tanpa lubrikasi dan dengan lubrikasi menggunakan cairan collagen. Hasil pehitungan densitas menunjukkan bahwa penambahan kadar HA dalam komposit akan menambah nilai densitas. Hasil pengujian keausan menunjukkan bahwa spesimen komposit dengan 40% hidroksiapatit memiliki ketahanan aus paling baik yaitu sebesar 4,16×10-6 mm3/Nm untuk pengujian tanpa lubrikasi dan 3,55×10-6 mm3/Nm untuk pengujian dengan lubrikasi. Penambahan lubrikasi dapat menurunkan besarnya laju keausan sebesar 14%. Pengamatan permukaan kontak menunjukkan bahwa mekanisme keausan yang terjadi adalah kombinasi antara keausan adhesif serta abrasif.
Dalam dunia kedokteran jika terapi fisik dan obat-obatan tidak dapat mengatasi kelainan atau kerusakan pada sendi rahang pasien maka jalan satu-satunya adalah dengan dilakukan perawatan bedah dengan ...mengganti sendi yang mengalami gangguan dengan prosthesis sebagai pengganti anggota gerak yang hilang. Dalam penelitian ini digunakan material hidroksiapatit dalam pengujian bending karena memiliki komposisi kimia yang sama dengan jaringan keras pada manusia seperti gigi dan tulang. Penelitian ini bertujuan mencari nilai tegangan bending maksimum yang bisa diterima oleh komposit hidroksiapatit. Penelitian ini dilakukan dengan mengambil variasi fraksi volume hidroksiapatit 40% HA, 50% HA, 60% HA, dan 70% HA. Setelah itu material di uji bending dengan menggunakan standar ASTM D790 dengan menggunakan metode pengujian three point bending. Dari penelitian ini didapatkan bahwa tegangan bending maksimum sebesar 31.2 Mpa pada spesimen dengan persentase hidroksiapatit 50% fraksi volume. Fraksi ini adalah fraksi yang paling optimal di antara variabel-variabel uji lain.
Provider: - Institution: - Data provided by Europeana Collections- Since the beginning of this century the bone tissue engineering has developed into one of the essential research fields in ...reconstructive medicine, as an alternative approach compared with the conventional bone transplants. The main objective of this kind of therapy is to repair, regenerate and reconstruct the damaged or disease-stricken tissue. Tissue engineering is based on scaffolds which are of various biomaterials capable of participating in the process of bone tissue regeneration. A great number of materials has been researched and analyzed so as to be used as a scaffold for cell seeding. Therefore, the scaffold would enable those cells to grow, proliferate and penetrate the bone defects, whereupon the new tissue would take over the structure and function of the damaged tissue. Hydroxyapatites and other calcium phosphate materials were widely used as bone replacements for more than two decades. However, the poor mechanical features of porous hydroxyapatites led to their limited use. In case when they are combined into the compound materials together with polymer/biopolymer thin films, the porous hydroxyapatites acquire optimal characteristics required by scaffolds, which can offer excellent conditions for cell infiltration, growth and activity which is necessary in bone tissue engineering. The main objective of the doctoral dissertation was to carry out the characterization, examine the biocompatibility and biofunctionality of porous hydroxyapatite created by the modified hydrothermal method (pHAP), porous hydroxyapatite created by the modified hydrothermal method in combination with PLGA (Phap + PLGA) and porous hydroxyapatite created by the modified hydrothermal method in combination with metformin (pHAP + metformin). The research included the characterization of the tested materials by means of Fourier transform infrared spectroscopy (FTIR), X-ray distraction method (XRD), atomic forse microscopy method (AFM), scanning electorn microscopy analysis(SEM) and BET method. Biocompatibility was examined by MTT test (indirect contact of the tested materials with the cell culture L 929 fibroblasts), LDH test (direct contact of the tested materilas with the cell culture L929 fribroblasts) and test of local effects on skin in rabbits. Biofunctionality of the examined materials was researched by their implatation into defects of critical size of 6mm in the region of parietal bone in rabbits. After 12 weeks the animals were sacrifised, and tissue samples were prepared for pathohistological analysis. By means of the optical microscopy the following parametres were determined both quantitatively and qualitatively: the size of the defect, the presence of giant cells, the presence of neoangiogenesis, the presence of basophils, the presence of nonspecific inflammation in the tissue, the appearance of the newly created bone, the presence of fibroplasia in the tissue and the percentage of mineralization. The results showed that the examined scaffolds were perfectly designed and they had the ideal surface morphology which had an impact on how the hydroxyapatite deposit as well as on the material surface activity necessary for scaffolds. The examined materilas indicated the presence of cytotoxicity in indirect contact with cell culture, but also showed that their surfaces, in direct contact with cell culture, are suitable for cell adhering and their proliferation, and furthermore, they have features which enable the cell growth. The results of the test of local effects on skin in rabbits, showed that none of the examined materilas causes irritation and can be considered as non-irritating, so due to that fact they are suitable for in vivo application. The porouse hydroxyapatite and compound scaffold pHAP with PLGA led to the creation of the new bone together with considerable presence of mineralization in critical sized defects. According to this reasearch, pHAP with PLGA has proved to be equal, and to certain parameters, even better than the applied BioOssR golden standard. pHAP with metformin did not show expected results. The research has shown that, in further experiments, pHAP together with PLGA can be the basis for generating the scaffold in bone tissue engineering and provide settlement of osteoblasts or any of osteoblast precursors, their growth and differentiation.- Tkivno inženjerstvo koštanog tkiva se u ovom veku razvilo u jedno od glavnih polja istraživanja u regenerativnoj medicini. Ono predstavlja alternativni pristup u odnosu na konvencionalne koštane transplantate. Osnovni cilj ove vrste terapije je da popravi, regeneriše i rekonstruiše oštećeno ili bolešću zahvaćeno tkivo. Osnovu tkivnog inženjerstva čine ćelijski nosači koji predstavljaju razne vrste biomaterijala sposobnih da učestvuju u regeneraciji koštanog tkiva. Veliki broj materijala je istraživan i analiziran sa ciljem da se koristi kao ćelijski nosač na koji bi mogle da se zasejavaju ćelije. Ćelijski nosač koji bi tim ćelijama omogućio rast, proliferaciju i njihovo unošenje u defekte kosti nakon čega bi novostvoreno tkivo preuzimalo strukturu i funkciju obolelog dela tkiva. Hidroksiapatiti i drugi kalcijum fosfatni materijali imali su široku upotrebu kao koštani zamenici više od dve decenije. Zbog loših mehaničkih osobina poroznih hidroksiapatita došlo je do ograničenja njihove primene. U slučaju kada se kombinuju u kompozitne materijale sa odgovarajućim polimer/biopolimer tankim filmovima, porozni hidroksiapatiti dobijaju optimalne osobine potrebne ćelijskim nosačima, koje mogu pružiti odlične uslove za infiltraciju, rast i aktivnost ćelija neophodnih u tkivnom inženjerstvu kosti. Osnovni cilj doktorske disertacije bio je izvršiti karakterizaciju, ispitati biokompatibilnost i biofunkcionalnost poroznog hidroksiapatita dobijenog modifikovanom hidrotermalnom metodom(pHAP), poroznog hidroksiapatita dobijenog modifikovanom hidrotermalnom metodom u kombinaciji sa PLGA (pHAP+PLGA) i poroznog hidroksiapatita dobijenog modifikovanom hidrotermalnom metodom u kombinaciji sa metforminom (pHAP+metformin). Istraživanje je podrazumevalo karakterizaciju ispitivanih materijala uz pomoć Fourier transform infracrvene spektroskopije (FTIR), metodom rentgen difrakcije (XRD), metodom atomski forsirane mikroskopije (AFM), analizom skening elektronske mikroskopije (SEM) i BET metodom. Biokompatibilnost je ispitivana pomoću MTT testa (indirektni kontakt ispitivanih materijala sa ćelijskom kulturom L 929 fibroblasta), LDH testa (direktni kontakt ispitivanih materijala sa ćelijskom kulturom L 929 fibroblasta) i testom kutane iritacije. Biofunkcionalnost ispitivanih materijala bila je istraživana njihovom implantacijom u defekte kritične veličine od 6 mm u predelu kalvarije kunića. Nakon 12 nedelja životinje su bile žrtvovane, a uzorci tkiva su obrađeni za patohistološku analizu. Optičkom mikroskopijom kvantitativno i kvalitativno obrađivani su sledeći parametri: veličina defekta, prisustvo džinovskih ćelija, prisustvo neoangiogeneze, prisustvo bazofila, postojanje znakova nespecifičnog zapaljenja u tkivu, pojava novostvorene kosti, prisustvo fibroplazije u tkivu i procenat mineralizacije. Rezultati istraživanja pokazuju da su ispitivani ćelijski nosači bili savršeno dizajnirani i da su imali idealnu morfologiju površine koja je uticala na način deponovanja hidroksiapatita kao i na aktivnost površine materijala neophodne za ćelijske nosače. Ispitivani materijali pokazali su postojanje citotoksičnosti u indirektnom kontaktu sa kulturom ćelija, ali i da su njihove površine u direktnom kontaktu sa kulturom ćelija pogodne za adheriranje ćelija i za njihovu proliferaciju i da se odlikuju karakteristikama koje omogućavaju rast ćelija. Rezultati testa kutane iritacije pokazali su da ni jedan od ispitivanih materijala ne izaziva iritaciju i da se mogu smatrati neiritirajućim pa su iz tog razlog pogodni za primenu u in vivo uslovima. Porozni hidroksiapatit i kompozitni ćelijski nosač pHAP sa PLGA doveo je do stvaranja nove kosti uz značajno prisustvo mineralizacije u defektima kritične veličine kalvarije kunića. pHAP sa PLGA se pokazao, na osnovu ovog istraživanja jednak, a po nekim parametrima i bolji od primenjenog zlatnog standarda BioOss-a. pHAP sa metforminom nije pokazao očekivane rezultate. Istraživanje je pokazalo da pHAP sa PLGA u daljim eksperimentima može da posluži kao osnova za dobijanje ćelijskog nosača u tkivnom inženjerstvu kosti i da omogući vezivanje osteoblasta ili nekog od prekursora osteoblasta, njihov rast i diferencijaciju.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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