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EN
The aim of the present work was to develop new composite materials based on two biocompatible polymers (sodium alginate and polycaprolactone) intended for use in the treatment of bone tissue defects. Tests carried out to obtain polymer-fibre composites using two resorbable polymers demonstrated the possibility of attaining composites with mechanical properties that are suitable from the point of view of their applications. Young’s modulus values for the composite systems analysed (254-389 MPa) are higher than for an unmodified PCL sheet. Irrespective of the fibrous phase used, the PCL matrix demonstrates stability in in vitro conditions. The constant pH values and small changes in the ionic conductance of the water indicate that these materials undergo gradual but slow degradation.
PL
W pracy opracowano warunki wytwarzania kompozytów opartych o dwa biodegradowalne tworzywa. Przeprowadzone badania wykazały zróżnicowany wpływ obecności poszczególnych rodzajów fazy włóknistej na właściwości wytrzymałościowe, właściwości fizykochemiczne powierzchni oraz stabilność materiałów kompozytowych podczas procesu inkubacji w warunkach in vitro. W oparciu o uzyskane wyniki można przypuszczać, iż wytworzone materiały kompozytowe na bazie włókien alginianowych, będących nośnikami substancji czynnych, będą powodować wytworzenie dogodnych warunków do krystalizacji apatytu w żywym organizmie.
EN
Biomaterials basing on natural polysaccharides, i.e. hiauronic acid, alginate, chitosane are an alternative for already applied bioresorbable synthetic materials basing on synthetic polyhydroxy acids. Their main advantages are good accessibility, low cost, easy forming and high biocompatibility. Additionally , they are a perfect matrix for bioactive nanoparticles i.e. hydroxy apatite (HAp), tricalcium phosphate (TCP) and silica (SiO2). The work presents results of research on nanocomposite consisting of chitosane matrix (CS) modified with a nanofiller, which was natural montmorillonite (MMT). Nanocomposite foils were produced by the casting method. In order to induce better biocompatibility, the surface of the CS/MMT composite was neutralized (bath in NaOH solution). The nanocomposite foils were subjected to a bioactivity test by incubation in SBF at 37oC for 7 days. It was observed that the CS/ MMT material surface showed a local supersaturation, which was a result of apatite nucleation. The CS/ MMT nanocomposites were investigated using FT-IR ( Fourier Transform Infrared Spectroscopy) and Fourier Raman Spectroscopy. FTIR measurements o f the samples were carried out on the transmission and reflection modes. The FTIR microscopy spectra were collected using BioRad Excalibur with ATR attachment as well as microscope UMA500 equipped with MCT detector. Spectra were measure at 4 cm -1 resolution in the region from 4 000 cm -1 to 600 cm -1 . FT-Raman spectra were obtained using a FTS 6000 Bio-Rad spectrometer with Ge detector. The samples were excited with a Nd-YAG laser (1064nm). Additional all materials in all steps experiments were observed under Scanning Electron Microscopy (Nova Nano SEM). Vibrational spectroscopy methods (FT Raman and FTIR) can be used for investigation of nanocomposite foils basing on biopolymers. High sensitivity the applied spectroscopy techniques show that in the result of the neutralization of CS/ MMT foil (via incubation in NaOH solution the biopolymer chain breaks. This phenomena is visible by intensity ratio between COC/COH bands. Increase of reactivity of chitosane chain lead to entrapment of PO4+3-, which is the origin of the apatite forms nucleation process. Chemical treatment of the nanocomposite foils, i.e. NaOH washes in fluences their chemical structure and microstructure. Neutralisation of the foils is the first processing stage which precedes the potential use o fCS/ MMT foils in biomedical applications. The materials show a tendency to apatite crystallisation which may support regeneration of damaged bone tissue. The applied spectroscopic methods allowed to observe changes in the whole volume of the sample. Individual ATR measurements taken at various spectral ranges and penetration depths allow to observe subtle changes in the polymer matrix caused by chemical treatment (NaOH and SBF incubation). Results of the investigations indicate that in the CS/ MMT systems new chemical bonds and related to them vibrations appear. Quantity and quality of the interact ions is related to characteristics of the nanoparticle and the presence of forming apatite structures.
3
Content available remote Zastosowanie technik FTIR w badaniach nanokompozytów polimerowo-ceramicznych
PL
W pracy zbadano nanokompozytowe tworzywa polimerowo-ceramiczne, w których jako osnowę zastosowano biopolimer naturalny należący do grupy polisacharydów (chitosan, CS). Jako nanonapełanicz wykorzystano komercyjny glinokrzemian warstwowy - montmorylonit w dwóch odmianach: MMT-K5 i MMT-K10. Nanometryczne cząstki ceramiczne scharakteryzowano ze względu na powierzchnię rozwinięcia (BET), wielkość nanocząstek w roztworze rozpuszczalnika (DLS) i morfologię (TEM). Materiały wyjściowe: chitozan, MMT K5 i K10 poddano również analizie fourierowskiej spektroskopii w podczerwieni (FTIR) ze względu na późniejszy zakres badań otrzymanych na ich bazie tworzyw. Materiały nanokompozytowe otrzymano techniką odlewania, stosując kilkustopniową metodę dyspersji nanocząstek w matrycy. Udział nanonapełaniacza był stały i nie przekraczał 3% wag. MMT. Folie nanokompozytowe (CS/MMT-K5 i CS/MMT-K10) poddano badaniom FTIR. Materiałem odniesienia była niemodyfikowana folia CS. Widma badanych materiałów rejestrowano w zakresie środkowej podczerwieni techniką transmisyjną i refleksyjną techniką całkowitego wewnętrznego odbicia (ATR). Wykorzystując techniki FTIR, przedstawiono oddziaływania na granicy faz: nanocząstka a matryca biopolimerowa. Wykazano, że dzięki zastosowanym technikom FTIR można otrzymać informacje na temat rozłożenia nanonapełniacza w osnowie, jednorodności folii nanokompozytowej, skłonności nanonapełniacza do sedymentacji w trakcie procesu suszenia. Dobrane techniki badawcze pozwoliły na otrzymanie informacji uśrednionych (transmisja) oraz informacji z powierzchni tworzywa przy różnej głębokości penetracji (ATR z kryształem germanowym i diamentowym) i wielkości badanej powierzchni.
EN
The nanocomposites from renewable sources are considered to be a group of perspective materials. The main advantage of the nanocomposite materials based on natural biopolymers such as polysaccharides e.g. alginates or chitosane is their simple utilization and safe products of degradation. The additional advantage of nanocomposites based on chitosane and montmorylonite (MMT) is availability and low cost of the component materials. However, successful preparation of the nanocomposites still encounters many problems mainly related to proper dispersion of nano-fillers. High surface area, and high free surface energy are the cause of agglomeration of the nanoparticles, which then lose ability to create first-, and second-order interactions with a polymer matrix. In the result, the nano-filler becomes submicron or micron phase which because of its low fraction, not exceeding 10% (volume or weight), act as a defect weakening the polymer matrix. The situation between nanofillier and polymer matrix can be observed used the most popular measurement technique: thermal analyses (DSC, TG, DTA), microscopic methods such as: AFM, SEM, TEM, and spectroscopic methods; FTIR, Raman, XPS. In order to follow the structural changes in the nanocomposites materials a variety of investigative methods suitable for verification of complex phenomena taking place in the materials is utilized. The spectroscopy techniques FTIR can be relatively easily applied both to powder and foil samples on nanocomposite materials. Obtained result can be averaged in the case of transmission techniques or it may describe an area of a sample in the case of ATR technique. FTIR techniques enables better observation and interpretation of subtle changes taking place in the polymer matrix than XRD and SEM/EDS methods, especially when the investigated material is a nanocomposite polymer foil. In the work efforts of production of a series of nanocomposites based on natural chitosane and nano-clay (MMT) were taken. The nanocomposites materials was obtaining by casting method. Mechanical and ultrasound stirrer was used to better homogenization between nanoclay particles and biopolymer matrix. Two types of MMT (MMT-K5 and MMT-K10) with different particle size (DLS) and specific surface area (BET) were used. The nanoparticles morphology was examined with transmission electron microscopy (TEM). In each nanocomposite, the nano-filler amount was 3% wt. Dispersion of the nano-filler within the polymer matrix was investigated with the use of FTIR method (transmission mode, FTIR microscopy). FTIR measurements of the samples were carried out on the transmission mode in the region from 400 to 4000 cm-1 and ATR method in the region from 700 to 4000 cm-1. For the transmission mode powder samples were prepared in the form of potassium bromide (KBr), whereas the foils of the polymer samples were placed directly in the spectrometer. In the ATR method which allow to analyze the deep of penetration of the samples two different crystals were used: german and diament. In this way were observed how the clay (MMT-K5 or MMT-K10) influenced on the chemical structure of biopolymer chain.
4
Content available remote Nanokompozyty polimerowe do zastosowań medycznych
PL
Praca obejmuje badania nad biozgodnymi polimerami modyfikowanymi nanocząstkami ceramicznymi. Przedmiotem badań były nanokompozyty polimerowe, wytworzone z trzech różnych polimerów: polimeru biostabilnego (polisulfon - PSU), polimeru resorbowalnego (poli(L/DL)laktyd - PL(L/DL)A) oraz polimeru pochodzenia naturalnego (chitozan - CS). Jako modyfikatory zastosowano nanometryczne cząstki ceramiczne: montmorylonit (MMT), krzemionkę (SiO2) oraz nanorurki węglowe (CNT). Materiały nanokompozytowe zostały scharakteryzowane pod względem parametrów biologicznych i mechanicznych. Wyniki badań wskazują, że modyfikacja wszystkich trzech grup polimerów, przy zastosowaniu nanocząstek ceramicznych, to skuteczna droga do otrzymywania biozgodnych, bioaktywnych tworzyw, posiadających dodatkowo znacznie lepsze parametry mechaniczne w porównaniu z czystymi polimerami.
EN
Nanotechnology generally bases on modification of materials' behaviour. One of the first real products of nanotechnology is polymer nanocomposites, which are a combination of polymer matrix and nanoparticles (so called nanofillers) that have at least one dimension in a nanometric range. The nanofillers such as nanopowders, nanofibers, or nanotubes modify the polymer matrix on a molecular level. Properties of such materials depend both, on the matrix, and the nanoparticles. These materials may exhibit enhanced mechanical (tensile strength, stiffness, toughness), gas barrier, thermal expansion, thermal conductivity, ablation resistance, optical properties, chemical properties, electronic and magnetic properties. Polymer nanocomposites is a promising class of hybrid materials derived from both synthetic and natural polymers and inorganic/organic nanoparticles. The introduction of nanoparticles into a polymer matrix ensures significant improvement of the material's properties. Polymer nanocomposites are of immense interest of such biomedical technologies as; tissue engineering, bone replacement, dental applications and controlled drug delivery. Current opportunities for application of polymer nanocomposites in biomedical applications arise from their tailored bioactivity, biodegrabilty, and mechanical properties. Interaction between nanofillers and a polymer matrix enables them to act as molecular bridges in the polymer structure. High adhesion of nanoparticles to the polymer matrix results in the enhanced strength and Young's modulus of the nanocomposites comparing to conventional composites. The paper presents results of our investigations on three kinds of nanocomposites basing on biocompatible polymer matrices and nanoparticles such as; MMT, SiO2 and CNTs which constitute temporary replacing materials in a missing bone tissue. Such material should be biocompatible, osteoinductive, osteoconductive and porous as well as mechanically compatible with the bone tissue. The results of biological investigations provided evidence of good adhesion, proliferation and morphology of osteoblastic cells on the surface of each polymer nanocomposites. The ability of the polymer nanocomposite to cell attachment, spreading and growth in in vitro conditions, combined with the good mechanical properties suggest potential use of these material as biomedical devices, particularly in the area of regenerative medicine. Values of Young's modulus increase in all nanocomposites, and their tensile strength depends on dispersion of the nanoparticles in the polymer matrix, and in most cases decrease because of agglomeration of the nanoparticles. Polymer nanocomposite containing bioactive nanoprticles shows osteoinductive properties. Treatment of the nanocomposite samples in the simulated body fluid (SBF) induced some changes on the surface of the material containing bioactive ceramic nanoparticles. The results of the tests with SBF show that the material is able to produce apatite structure on its surface.
EN
Biomaterials basing on natural polysaccharides, i.e. hiauronic acid, alginate, chitosane are an alternative for already applied bioresorbable synthetic materials basing on synthetic polyhydroxyacids. Their main advantages are good accessibility, low cost, easy forming and high biocompatibility. Additionally, they are a perfect matrix for bioactive nanoparticles i.e. hydroxyapatite (HAp), tricalcium phosphate (TCP) and silica (SiO2). The work presents results of research on nanocomposite consisting of chitosane matrix (CS) modified with a nanofiller, which was natural montmorillonite (MMT). Nanocomposite foils were produced by the casting method. In order to induce better biocompatibility, the surface of the CS/MMT composite was neutralized (bath in NaOH solution). The nanocomposite foils were subjected to a bioactivity test by incubation in SBF at 37oC for 7 days. It was observed that the CS/MMT material surface showed a local supersaturation, which was a result of apatite nucleation. The CS/MMT nanocomposites were investigated using FT-IR (Fourier Transform Infrared Spectroscopy) and Fourier Raman Spectroscopy. FTIR measurements of the samples were carried out on the transmission and reflection modes. The FTIR microscopy spectra were collected using Bio-Rad Excalibur with ATR attachment as well as microscope UMA500 equipped with MCT detector. Spectra were measured at 4 cm-1 resolution in the region from 4000 cm-1 to 600 cm-1. FT-Raman spectra were obtained using a FTS6000 Bio-Rad spectrometer with Ge detector. The samples were excited with a Nd-YAG laser (1064nm). Additional all materials in all steps experiments were observed under Scanning Electron Microscopy (Nova NanoSEM). Vibrational spectroscopy methods (FT Raman and FTIR) can be used for investigation of nanocomposite foils basing on biopolymers. High sensitivity the applied spectroscopy techniques show that in the result of the neutralization of CS/MMT foil (via incubation in NaOH solution) the biopolymer chain breaks. This phenomena is visible by intensity ratio between COC/ COH bands. Increase of reactivity of chitosane chain lead to entrapment of PO43-, which is the origin of the apatite forms nucleation process. Chemical treatment of the nanocomposite foils, i.e. NaOH washes influences their chemical structure and microstructure. Neutralisation of the foils is the first processing stage which precedes the potential use of CS/MMT foils in biomedical applications. The materials show a tendency to apatite crystallisation which may support regeneration of damaged bone tissue. The applied spectroscopic methods allowed to observe changes in the whole volume of the sample. Individual ATR measurements taken at various spectral ranges and penetration depths allow to observe subtle changes in the polymer matrix caused by chemical treatment (NaOH and SBF incubation). Results of the investigations indicate that in the CS/ MMT systems new chemical bonds and related to them vibrations appear. Quantity and quality of the interactions is related to characteristics of the nanoparticle and the presence of forming apatite structures.
EN
Nanocomposite materials can be used in many application. In this study polymer–based nanocomposites modified with carbon nanotubes (CNTs) and ceramic silica nanoparticles (nSiO2) were used. Size and shape of nanoparticles were observed using transmission electron microscope (TEM). It was shown that, this parameter changes during mixing of nanoparticles with solvent or polymer solution. Dispersion of nanoparticles depends on their chemical composition. The CNTs are more compatible with polymer (PLDL) than nSiO2. Nanoparticles influence rheological parameters of the polymer solution (increase of viscosity). Distribution of nanoparticles within the polymer matrix was determined using DLS method. Nanocomposites in the form of thin foils were used for mechanical tests which show that small amount of nanoparticles increases tensile strength (Rm) and Young’s modulus (E) of the material. The biological properties of the polymer-based nanocomposite materials like viability and proliferation were measured using osteoblast-like human cells MG63. Results of these investigations show that both types of the nanocomposites are suitable for promoting bone tissue for faster regeneration process.
EN
Hybrid biomaterials due to their unique structure may become an alternative for many popular composite and nanocomposite materials. Multilevel modification of their matrix manifesting itself in the presence of particles of different sizes i.e., micrometric, submicrometric and nanometric together with the variety of shapes of a modyfing phase (nanometric fibres, submicron particles, coated nanoparticles) and its different chemical character make the hybrid materials similar to natural tissue. Bone tissue structure is particulary close to this model in which collagen fibres and hydroxyapatite particles and nanoparticles have not only different form but first of all they play different role in the tissue which depends on their chemical nature. In the biomedical engineering syntetic hybride biomaterials are usually produced using resorbable and degradable polymer matrices and inorganic filers (ceramic bioactive particles; HAp, TCP, SiO2) or organic filers (collagen, polysaccharides e.g. alginate fibres). The main function of the modyfing phase is inprovement of the polymer matrix leading to bioactive, stronger material showing high biofunctionality. Production of hybrid materials is based mainly on experimental works, which is related to the presence in their matrix few phases with different properties which may interact. Hybrid materials do not follow the rule of mixtures thus it is difficult to predict behaviour of a material in which co-exis different chemical and phisical phases. In the work hybrid composite foils were produced in which modyfing phase consisted in; nanocomposite calcium alginate fibres modyfied with ceramic nanoparticles; HAp (CAH fibres), TCP (CAT fibres), SiO2 (CAS fibres) and MMT (CAM fibres). Short fibres were subjected to additional size reduction in vibration ball mill resultiong in submicron and nanometric phases. Size of the particels after grinding was determined by screening analysis and DLS method (for particels smaller than 500 nm). It was observed than the population of short fibres consist in three fractions i.e.; micrometric (~2μm, 50 wt.%), submicrometric (500–800 nm, 40 wt.%) and nanometric ( below 500 nm, 10 wt.%). The fibres and products of their grinding were homogenised in P(L/ DL)LA polymer solution (poly-L/DL-lactide, Purarorb 80, Purac Germany). A hybride material in the form of thin foils containing 2 wt.% of a modyfing phase were subjected to durability tests consisting in incubation in distilled water (30 days/37C). Monitoring of the medium pH and conductivity did not show changes related to harmful products of their decomposition. Osteoblast-like cells from MG-63 line contacted with the surface of the materials showed high viability (MMT test) comparable with the reference material (TCPS). High degree of adherence of the cells to the materal surface (CV test) testifies of potential abilities of the material stimulating proliferation of bone tissue cells. The highes rate of dynamic growth (increase of the cells number after 7 days of incubation) was observed for the material which was modified with CAS fibres and products of their grinding. The performed investigations have a preliminary character. Their results testify for potential osteoconductive or osteoinductive abilities of hybride materials basing on P(L/DL)LA and alginate nanocomposite fibres.
EN
Aim of this work was fabrication of a polymer-matrix nanocomposite based on polyacrylonitrile (PAN) and a layered silicate (phyllosilicate) - montmorillonite (MMT) as a nanofiller. Nanoparticles of the filler, which originated from a natural deposit, were subjected to a chemical treatment (ethylenediamine, MMT-amine) or thermal treatment (nanofiller carbonisation, MMT-amine -> MMT-carbo) which objective was to reach better compatibility between the matrix and the nanofiller. Influence of the treatment method on the nanofiller characteristics was determined by structure (XRD) and microstructure (SEM) analysis of MMT and its derivatives. MMT-PAN nanocomposites were produced by casting method. It was observed, that a form of the nanofiller affected dispersion efficiency of the nanometric phase within the polymer matrix, as well as the thermal stability of the nanocomposite. Mechanical tests (stretching) revealed better compatibility of an exfoliated nanofiller (MMT-carbo) with the polymer matrix, which resulted in increase of the nanocomposite strength.
10
Content available remote Polimerowe kompozyty gradientowe dla zastosowań medycznych
PL
W pracy otrzymano i scharakteryzowano polimerowe kompozyty gradientowe. Wytworzone materiały charakteryzowały się gradientem porowatości (tworzącym się in situ), gradientem trwałości w warunkach in vitro oraz gradientem właściwości mechanicznych. Kompozyty gradientowe otrzymano przez dodatek do resorbowalnej osnowy kopolimeru laktydu i glikolidu (PGLA) biopolimeru - alginianu sodu w postaci proszku (NaAlg). Metodą odlewania otrzymano folie kompozytowe o różnym udziale wagowym 27%). Na podstawie przeprowadzonych badań degradacji (trwałości w warunkach in vitro), pomiarów profilometrycznych, testów mechanicznych oraz obserwacji mikroskopowych zaprojektowano i wykonano kompozytowe struktury gradientowe. Następnie materiały w formie kostek o różnym udziale wagowym modyfikatora podda-no badaniom degradacji, stosując jako medium immersyjne płyn Ringera. Stopień degradacji kompozytów określono na podstawie zmian prędkości fali ultradźwiękowej oraz pH medium. Stwierdzono, że szybkość degradacji kompozytów zależy od udziału wagowego porogenu oraz od kolejności ułożenia warstw różniących się udziałem wagowym modyfikatora w kompozycie gradientowym.
EN
Functional gradation is one of characteristic feature of living tissue. Bioinspired materials open new approaches for manufacturing implants for bone replacement. Different routes for new implant materials are presented using the principle of functional gradation. In this paper an artificial biomaterial for bone replacement has been developed by building a graded structure consisting of resorbable polymer matrix modified with biopolymer powder. For preparation graded materials with different in situ porosity and in vitro durability diversification biopolymer in form of sodium alginate (NaAlg, powder) was introduced into resorbable polymer matrix of lactide-co-glicolide (PGLA). Than composite films were cast from polymer solution with deferent mass fraction of modifier (7-27%). On the basis of degradation tests (durability in in vitro conditions), profile measurements, mechanical tests and microscopic observations composite structures (cubical shape with different arrangement of composite layers) were designed. Two types of porosity gradients were obtained. These graded materials with different mass fraction of sodium alginate were investigated during the durability tests in Ringer solution. Degradation degree was defined on the basis of velocity changes of the ultrasonic wave and pH of the immersion medium. It was found that composite degradation rate depends on porogene mass fraction and it was also connected with its arrangement way in polymer matrix.
PL
Nanocząstki modyfikatora MMT, pochodzące z naturalnego złoża (Jelesovy Potok), poddano jednoetapowej obróbce chemicznej (interkalacja etylenodiaminą, MMT-amina) lub obróbce dwuetapowej, tj. chemicznej, a następnie termicznej (karbonizacja nanonapełniacza, MMT-amina→ MMT-karbo). Celem tych zabiegów było osiągnięcie lepszej kompatybilności pomiędzy nanonapełniaczem a osnową polimerową, PAN. Wpływ modyfikacji na postać nanonapełniacza określono poprzez badania struktury (XRD) i mikrostruktury (SEM) montmorylonitu i jego pochodnych (interkalowanego MMT-amina i eksfoliowanego MMT-karbo). Wpływ zastosowanych modyfikacji na wielkość cząstek MMT zbadano przy użyciu metody DLS. Stwierdzono, że postać nanonapełniacza (wcześniejsza obróbka MMT) wpływa na poprawę dyspersji fazy nanometrycznej w osnowie polimerowej PAN. Nanokompozyty polimerowe z poliakrylonitrylu (PAN), w których jako nanonapełniacz zastosowano glinokrzemian warstwowy - montmorylonit (MMT) otrzymano metodą odlewania. Największą trwałością termiczną charakteryzował się nanokompozyt, gdzie jako nanonapełniacz zastosowano interkalowany aminą MMT (TG/DSC). Badania mechaniczne wykazały większą kompatybilność nanonapełniacza eksfoliowanego (MMT-karbo) do matrycy polimerowej, powodującą wzrost wytrzymałości tego nanokompozytu (testy rozciągania).
EN
Aim of this work was fabrication of a polymer-matrix nanocomposite based on polyacrylonitrile (PAN) and a layered silicate (phyllosilicate) - montmorillonite (MMT) as nanofiller. Nanoparticles of the filler, which originated from a natural deposit, were subjected to a chemical treatment (ethylenediamine, MMT-amine), or thermal treatment (nanofiller carbonisation, MMT-amine→ MMT-carbo) which objective was to reach better compatibility between the matrix and the nanofiller. In order to improve compatibility of MMT-type particles with a polymer matrix they are subjected to chemical treatments which consist in an introduction of cations of alkylamonium or alkylophosphonate salts between stocks of aluminasilicate piles. The introduction of organic matter between the stocks of piles is called intercalation. The additional objective of this treatment, apart form inducing organophilic character of the particles (i.e. formation of organoclays), is increase of an interpile spacing. Better results of nanocomposite strengthening with MMT-type particles are achieved when an organoclay undergoes exfoliaion i.e. when it completely loses layered structure, and the nanofiller plates are separated with the polymer chains. Usually both above mentioned phenomena occur simultaneously i.e. part of the piles is intercalated, while the rest is completely delaminated (exfoliated). In such case a flocculated nanocomposite is produced. Montmorylonite fraction was separated by sedimentation from bentonite from Jelesovy Potok deposit (Slovakia). Particle size distribution was determined by DLS method using NanoSizer Nano-ZS apparatus. The second type of the nanofiller was montmorylonite intercalated with secondary amine. The main purpose of this treatment was hydrophobisation of MMT piles, which was expected to improve a compatibility of the nanofiller with the polymer matrix. The intercalation process was carried out by mixing MMT with the secondary amine (proportion MMT:amine; 1:2). The third type of the nanofiller, was produced by thermal treatment of MMT-amine at 1000°C for 15 min in oxidising atmosphere. Influence of the treatment method on the nanofiller characteristics was determined by structure (XRD), and microstructure (SEM) analysis of MMT and its derivatives. MMT-PAN nanocomposites were produced by casting method. It was observed, that a form of the nanofiller influenced efficiency of dispersion of the nanometric phase within the polymer matrix, as well as the thermal stability of the nano-composite (TG/DSC). Mechanical tests (stretching) revealed better compatibility of an exfoliated nanofiller (MMT-carbo) with the polymer matrix, which resulted in increase of the nanocomposite strength.
12
Content available remote Membrany kompozytowe przeznaczone na implanty okulistyczne
PL
Zaprojektowano i wykonano materiał kompozytowy przeznaczany na śródgałkowy implant okulistyczny (implant keratocytowy). Materiałem bazowym był syntetyczny niedegradowalny terpolimer (PTFE-PVDF-PP) o stwierdzonej biozgodności (norma PN-EN ISO 10993). Jako fazę porotwórczą zastosowano biodegradowalny polimer-alginian sodu (NaAlg), którego użyto w formie proszku i włókien. Biopolimer mieszano z roztworem terpolimeru. Kompozyty otrzymywano metodą odlewania, a następnie poddawano je obróbce fizykochemicznej w celu nadania im niezbędnej porowatości. W ten sposób otrzymano biomateriał o wysokiej porowatości otwartej z systemem porów połączonych. Średnia wielkość porów w biomateriale zależy od rozmiaru cząstek fazy porogennej oraz od jej rodzaju (włókna lub proszek NaAlg). Membrana kompozytowa jest tworzywem trwałym, odpornym na długotrwałe obciążenia zarówno statyczne, jak i dynamiczne. Niewielki wzrost porowatości i wzrost wielkości porów obserwowany po testach zmęczeniowych nie powoduje deformacji tworzywa membrany i nie prowadzi do jej zniszczenia. Powierzchnie membran mają charakter silnie hydrofobowy (wyniki pomiarów kąta zwilżania i energii powierzchniowej), co utrudnia adhezję makromolekuł, będącą powodem blokowania się porów membrany. Wysoki kąt zwilżania utrzymuje się również w przypadku zastosowania jako cieczy pomiarowej medium hodowlanego wzbogacanego albuminą. Otrzymane wyniki eksperymentalne stanowiły podstawę do podjęcia dalszych badań nad zachowaniem się materiałów membranowych w warunkach in vivo.
EN
Glaucoma is an disease in which increased intraocular pressure causes damages of the eye structure. This leads to destruction of ophthalmic nerve, and as a result, changes of the field of vision. As a secondary effect secondary changes in the eye structure are observed. The disease is caused by blocking of a natural porous eyeball structure so called drainage angle. Inflow of the aqueous medium from inside the eye to the anterior chamber is more difficult than in physiological state. This state leads to excessive accumulation of the aqueous medium in the eye ball. As a result, the increased intraocular pressure causes tissue ischemia and afterwards their necrobiosis leaing to atrophy of the ophthalmic nerve. The role of materials used in therapy of glaucoma is to decrease the pressure inside eye. Materials for such application should fulfill main criteria, such as biocompatibility, biostability and appropriate high porosity. Moreover, it is necessary to provide nonpenetrating filtration inside the eye. For long-term-use, the material applied for cornea implants also have to withstand static pressure and dynamic pressure changes and have to be stable in biological environment. Therefore, its durability in in vitro conditions plays an important role. A new composite material for intraocular ophthalmic implant (keratitis implant) was designed and manufactured. The composite matrix based on a synthetic non-degradable terpolymer (PTFE-PVDF-PP) with certified biocompatibility (PN-EN ISO 10993 standard). As a porogenic phase bio-degradable polymer - sodium alginate (NaAlg) in the form of powder and fibres was used. The biopolymer was mixed with terpolymer solution. Composites were manufactured by casting technique followed by such a physicochemical treatment which led to obtaining appropriate porosity. This procedure enable to manufacture biomaterial possessing high open porosity with interconnected pore system. The average pore size in biomaterial remains in relation with size of porogenic phases and the type of porogenic phases (fibres or particles of NaAlg). The composite membrane is a material durable and resistant to long-term static and dynamic loads. The slight increase of total porosity and pore size which was observed after fatigue tests did not lead to deformation of the membrane material and did not lead to its destruction. Surfaces of the membrane materials were highly hydrophobic (results of wetting angle measurements and surface energy determination). That prevent adhesion of macromolecules responsible for blocking of membrane pores. High value of wetting angle were registered not only in case of distilled water but also in case of using plasma enriched with albumins. On the basis of results of these experiments new tests in in vivo conditions were continued.
PL
Przedmiotem pracy są nanokompozytowe materiały membranowe wytworzone na bazie resorobalnych włókien z polialkoholu winylowego modyfikowanego nanocząstkami ceramicznymi HAp lub SiO2. Materiały scharakteryzowano pod względem fizykochemicznym (chropowatość, zwilżalność), mikrostrukturalnym (wielkość porów, porowatość), strukturalnym (DSC). Uwzględniając aplikacje materiału zbadano również kinetykę uwalniania bioaktywnych nanocząstek które stymulować mogą nukleację apatytu na powierzchni membrany. Wykazano ze dodatek nanokompozytowych włókien wpływa na obniżenie hydrofobowości powierzchni i wzrost jej chropowatości. Zmiany ilościowe tych parametrów powierzchni zależą od rodzaju wprowadzonej fazy nanokompozytowej. Obecność włókien PVA/SiO2 i PVA/HAp zmienia mikrostrukturę a także strukturę matrycy polimeru.
EN
Aim of the work is investigations on nanocomposite membrane materials based on resorbable fibres of polyvinyl alcohol modified with ceramic nanoparticles of HAp or SiO2. The materials were characterised in terms of their physicochemical properties (roughness, wettability), microstructure (porosity, pore size) and structure (DSC). Taking into consideration a possible application of the materials the kinetics of release of bioactive particles which may stimulate nucleation of apatite on a membrane surface was investigated. It was shown, that addition of the nanocomposite fibres lead to decrease of hydrophobicity of the surface and increase of its roughness. Quantitative changes of these parameters depend on the type of the introduced nanocomposite phase. The presence of PVA/SiO2and PVA/HAp fibres changes microstructure of the composite and structure of the polymer matrix PCL.
PL
Przedstawione w pracy wyniki badań dotyczą kompozytów polimerowo-włoknistych, które służyć maja jako mikronarzędzia okulistyczne – refraktory tęczówkowe. Otrzymano serię materiałów kompozytowych, w których fazą ciągłą stanowiły nanokompozytowe włókna: syntetyczne (PAN) lub naturalne (CA). W osnowę włókien na etapie wytwarzania wprowadzono Nanocząstki modyfikatora którym dla włókien PAN były nanorurki węglowe (CNT) a dla włókien biopolimerowych CA były nanocząsteczki krzemionki. Do wytworzenia elastycznych mikronarzędzi na bazie włókien nanokompozytowych zastosowano osnowę z żywicy epoksydowej (E 57). Sprawdzono ich właściwości fizykochemiczne, a także użytkowe w porównaniu z dostępnym produktem handlowym. Celem nadania kompozytom odpowiedniej gładkości i podwyższenia ich biozgodności narzędzia pokryto warstwą bioz-godnego polimeru (PCL). Przeprowadzono ocenę mikroskopową powierzchni kompozytów (mikroskop stereoskopowy, mikroskop optyczny), zbadano ich parametry fizyczne (długość, średnica, kąt zakrzywienia) a także stabilność wytworzonych materiałów (1m-sc/370C/H2O). W końcowej części eksperymentu przeprowadzono badania poręczności retraktorów zakładając je na gałki oczne świni (badania in vitro).
EN
Results of investigations presented in the work concern polymer-fibrous composites which can be used as ophthalmologic micro-tools – iris retractors. A series of composite materials was produced in which a continuous phase consisted of synthetic (PAN) or natural (CA) nanocomposite fibres. The fibres matrix was modified with filler nanoparticles such as carbon nanotubes (CNT) for PAN and silica for biopolymer fibres CA respectively. The matrix of elastic micro-tools based on the nanocomposite fibres consisted of epoxy resin (E 57). Their physicochemical properties and usability were compared with commercially available products. In order to provide proper smoothness of the composites surface and to increase their biocompatibility the micro-tools were covered with a layer of bio-compatible polymer (PCL). Surface of the micro-tools was observed and evaluated using an optical micro-scope and a stereoscope. Their physical parameters such as length, diameter and inflection angle, and stability in in vitro conditions (1 mth/37oC/H2O) were determined. The last part of experiments consisted of studies of practical application of the micro-tools in rabbit’s eye balls (in vitro studies).
16
Content available remote Kompozyty alginianowe - nośniki substancji bioaktywnych badania wstępne
PL
Alginiany stosowane są w bioinżynierii medycznej od wielu lat. Niniejsza praca poświęcona jest kompozytowym materiałom biopolimerowy otrzymywanym na bazie soli alginowych. Wytworzono trzy rodzaje kompozytów, których matrycę stanowiła sól alginianu sodu (NaAlg), natomiast fazą zdyspergowaną były materiały ceramiczne. W celu modyfikacji matrycy zastosowano trzy rodzaje dodatków: nanometryczny hydroksyapatyt (nHAp), nanometryczną krzemionkę (nSiO2) lub bioaktywne szkło (BG) o rozmiarach ziaren rzędu < 5 žm. Wyjściową mieszaninę złożoną z biopolimerowej osnowy (NaAlg) i zdyspergowanej fazy ceramicznej (3% wag.) zestalano w roztworze soli nieorganicznej (CaCl2). W wyniku reakcji chemicznej (wymiana jonowa Na+ na Ca2+) otrzymano materiały kompozytowe, w których matrycą dla cząstek ceramicznych była sól alginianu wapnia. Określono stopień skurczu materiałów kompozytowych Ca(Alg)2/nHAp, Ca(Alg)2/nSiO2, Ca(Alg)2/BG otrzymanych w postaci kul. Materiałem odniesienia były sfery z alginianu wapnia pozbawione dodatku. Stwierdzono, że stopień dyspersji modyfikatora w osnowie biopolimerowej (SEM/EDS) zależy nie tylko od rozdrobnienia materiału, ale przede wszystkim od powinowactwa chemicznego modyfikatora do osnowy kompozytu. Materiały kompozytowe poddano także badaniom trwałości, określając wpływ mediów immersyjnych (woda, PBS, płyn Ringera) na ich zachowanie się w środowisku in vitro. Stopień degradacji określano na podstawie zmian pH medium, a także na podstawie obserwacji mikroskopowych powierzchni kompozytów (SEM/EDS). Powyższe badania wykazały, że zastosowane materiały ceramiczne stanowić mogą źródło substancji bioaktywnych stymulujących regenerację tkanki kostnej.
EN
For many years alginates have been used in biomedical engineering. This study is devoted to biopolymeric composite materials based on alginate salts. Three kinds of composite materials were produced and characterised. Dispersed phase consisted of ceramic materials such as: nano-hydroxyapatite (nHAp), nano-silica (nSiO2) or bioglass (BG). The composite matrix was sodium alginate solution consolidated in inorganic salt solution (CaCl2). In effect of chemical reactions, ion exchange followed by gelling, composite materials Ca(Alg)2/nHAp, Ca(Alg)2/nSiO2, Ca(Alg)2/BG were obtained. The alginate spheres were made from the bio-polymer powder (NovaMatrix-Biopolymer, Norway) containing 60+65% of G monomer. The formation of the spheres was realised by dropping in the sodium alginate solution into a gelling bath with 3% CaCl2 solution. The biopolymer matrix (NaAlg) was modified with: 3% wt. nanohydroxyapatite (AGH-UST, Department of Advanced Ceramics), 3% wt. colloidal silica (nSiO2), 3% wt. bioglass (AGH-UST, Department of Glass and Amorphous Coatings Technology). Spheres without modifying agent were used as the reference material. Surface of the composite spheres and their shrinkage was investigated using stereoscope microscope. Microstructural features of composites beads were observed under scanning electron microscope. Dispersion of ceramic particles in the biopolimer matrix were investigated. All samples Ca(Alg)2/nHAp, Ca(Alg)2/n-SiO2, Ca(Alg)2/BG were tested in vitro condition (incubated in water, at 37° C/30 days). Curves of changing pH immersion medium were the same in all types of samples. Result of investigation shown that degradation time of the investigated composite materials is different, and depends on a presence of Na+, K+, and Cl ions. Their durability decreases in the following order of immersing medium: PBS›Ringer solution›water. Dispersion of the modyfing particles depends on their chemical characteristics and size. The best dispersion was achieved in case of n-HAp particles, and the worst in case of BG. The alginate spheres may be an effective carrier of bioactive substances, such as nHAp, n-SiO2, BG, which are released during their degradation and can increase reconstruction and regeneration rates of the damaged tissue.
17
Content available remote Kompozytowe retraktory tęczówki - badania wstępne
PL
Przedstawiono wyniki badań wstępnych nad kompozytami włóknistymi, które będą wykorzystane do wytworzenia okulistycznych mikronarzędzi chirurgicznych w formie retraktorów tęczówkowych. Aktualnie do wytworzenia takiego narzędzia stosowane są czyste polimery, które przy bardzo małych przekrojach poprzecznych wyrobów są bardzo delikatne i często ulegają mechanicznemu uszkodzeniu. W pracy wytworzono serię materiałów kompozytowych, w których fazą zbrojącą były różne rodzaje włókien, takich jak naturalne (celuloza, jedwab), polimerowe (PAN) i biopolimerowe (Ca(Alg)2, Zn(Alg)2), a osnowę stanowiły dwa rodzaje żywic epoksydowych (E601 i E540). Sprawdzono ich właściwości fizykochemiczne, a także użytkowe w porównaniu z dostępnym produktem handlowym. Uformowane z kompozytów retraktory pokrywano cienką powłoką polimeru na bazie teflonu. Przeprowadzono ocenę mikroskopową powierzchni kompozytów (mikroskop stereoskopowy, mikroskop optyczny), zbadano ich parametry fizyczne (długość, średnica, kąt zakrzywienia), a także stabilność wytworzonych materiałów w warunkach in vitro (1 m-sc/37°C /H2O). W końcowej części eksperymentu przeprowadzono badania poręczności retraktorów, zakładając je na gałki oczne świni.
EN
The most popular retractors used in ophthalmology practice are made of plastics, usually nylon. Their main drawback is high stiffness of heads, which may cause many complications such as: damage of the iris constrictor, or iris atony (lack of reaction of the iris to a change in light intensity). The second group of materials used for the retractors is metals such as gold and titanium. Although they are easier to make required shapes, they could be dangerous due to their sharp tips which may cause iris rupture, lens capsule rupture or damage of corneal endothelium. Because of common incidence of eye affections requiring application of the iris retractors, much effort is put into investigations of new, biocompatible materials, which would be easy to apply during the operation, and on the other hand would minimise the risk of occurrence of post-surgery complications. The work presents preliminary results on fibrous composites which are planned to be used as elastic materials for production of ophthalmology microtools in the form of iris retractors. At present, for this purpose pure polymers are often used. The main drawback of such tools is their small cross section area, which makes them mechanically sensible, often resulting in their fracture. In this work number of composite materials containing various fibrous reinforcements such as natural fibres (cellulose, silk), polymer fibres (PAN), and biopolymer fibres (Ca(Alg)2, Zn(Alg)2) and two types of epoxy resins (E601, E540) as the composite matrix were prepared. Physicochemical properties of these composites, as well as their practical usefulness were compared to a commercially available polymer product. In order to provide suitable smoothness of the surface, and to improve bio-compatibility of the composites, the retractors were covered with a layer of teflon-based polymer. Surfaces of the composites were evaluated microscopically (stereoscopic microscope, optical microscope), and physically (length, diameter, angle of curvature). The last part of the research was an assessment of practical usefulness of the composite retractors by installing them in the pig eyeball.
18
Content available remote Degradowalne skaffoldy kompozytowe w chirurgii kostnej
PL
Celem pracy było wytworzenie materiałów kompozytowych, które służyć mają jako porowate podłoża przeznaczane dla inżynierii tkankowej. Do konstrukcji tych materiałów zastosowano biopolimer alginian sodu (NaAlg), który w pierwszym etapie poddawano obróbce chemicznej (kąpiele żelujące w roztworze CaCl2). Materiał formowano do postaci mikrosfer o średnicy d ~ 300 +400 žm. Stanowił on jedną z faz porotwórczych dla syntetycznej matrycy polimerowej (PGLA). Drugim porogenem, jaki zastosowano w materiale kompozytowym, był wyjściowy proszek z alginianu sodu (ziarna wyjściowe o średnicy d ~ 260 žm). W następnym etapie materiał biopolimerowy (kulki alginianowe z Ca(Alg)2 i wyjściowy proszek z NaAlg) wprowadzano do matrycy z kopolimeru laktydu i glikolidu (PGLA), otrzymując w ten sposób serię materiałów kompozytowych o różnym udziale masowym porogenu (60+63% wag. porogenu). Badano zachowanie się materiałów kompozytowych w środowisku biologicznym (badania degradacji in vitro), stosując jako medium immersyjne wodę i izotoniczny płyn wieloelektrolitowy (płyn Ringera). Stwierdzono, że szybkość degradacji kompozytu zależy od postaci porogenu. Szybszą degradację obserwuje się w przypadku zastosowania jako fazy porotwórczej proszku z alginianu sodu (monitoring przewodnictwa jonowego i pH płynu immersyjnego, obserwacje SEM). Dodatkowo wykazano (XRD), że zastosowana faza porotwórcza - kule z alginianu wapnia (Ca(Alg)2) są odpowiedzialne za krystalizację w porach materiału struktur apatytowych, a zatem otrzymany materiał może być uważany za materiał bioaktywny.
EN
The aim of this study was to form composite materials which can be use as porous scaffolds for tissue engineering. The sodium alginate (powder form) was used as a biopolymer. In the first stage of the experiment alginate powder was chemically formed in bath gelation (CaCl2 solution). During the formation process the spherical shape of the material was obtained. The diameter's range was between 300 and 400 žm. Alginate spheres were one of the porogene's phases which were used in the synthetic polymer matrix (PGLA). The second porogene which was used in the composite material was the initial alginate powder (grain's diameter, d ~260 žm). In the next stage the biopolymer material (alginate spheres with different diameters and alginate powder) were introduced into the polylactide-co- -glicolide matrix (PGLA). In that way various series of composite materials with different volume fractions of porogene were obtained (PGLA / spheres Ca(Alg)2 with 60% of porogene and PGLA/spheres Ca(Alg)2/powder NaAlg with 63% of porogene). The behavior of composite materials in the biological environment was investigated (degradation test). As an immersion medium distilled water and an isotonic solution (Ringer) were used. On the basis of the pH medium changes and also from the observation of composite surfaces (optical microscope, SEM) the degradation rate was determined. Additionally, it was demonstrated (XRD) that porous materials such as spheres made of calcium alginate (Ca(Alg)2 are responsible for forming an apatite structure in the material's pore. The obtained material can be considered as bioactive composite scaffolds.
PL
Otrzymano włókna alginianowe zawierające w swojej budowie rozproszony bioaktywny nanododatek hydroksyapatytu. Włókna te charakteryzują się wysokimi właściwościami sorpcyjnymi oraz wartością wytrzymałości właściwej powyżej 20cN/tex odpowiednią do przerobu na kompozyty przeznaczone do zastosowań medycznych.
EN
Alginate fibres containing in their structure a dispersed bioactive hydroxyapatite nano-additive were obtained. These fibres are characterized by high sorption properties and a tensile strength of over 20cN/tex, which is adequate for the production of composites designed for medical purposes.
PL
Silikonowe protezy twarzy (epitezy, ektoprotezy, protezy zewnętrzne) stosowane są u pacjentów, którzy w wyniku zabiegu chirurgicznego, w ramach leczenia chorób nowotworowych, wad wrodzonych, urazu utracili tkanki miękkie i twarde w zakresie twarzoczaszki np. oko, ucho, nos. Rekonstrukcje protetyczne wykorzystuje się w przypadku, gdy metody chirurgii plastycznej są nieskuteczne lub nie mogą być zastosowane. Istnieją różne metody umocowania ektoprotez. Badania kliniczne i ankietowe wykazały, iż większość pacjentów w pierwszej kolejności wybierała kleje medyczne. Niestety kleje te charakteryzują się krótkim czasem trwałego przytwierdzenia protezy do miejsca ubytku. W pracy zbadano przyczepności trzech rodzajów materiałów silikonowych przytwierdzanych do skóry pacjentów za pomocą klejów i taśm komercyjnych. W celu poprawy adhezji tworzywa zastosowano dwa rodzaje modyfikacji powierzchni. Zbadano wpływ obróbki mechanicznej na powierzchnie silikonów (gwarantujący wzrost chropowatości powierzchni). Zbadano także skuteczność chemicznej metody obróbki powierzchni (trawienie tworzywa w roztworach kwasów nieorganicznych). Celem weryfikacji skuteczności zastosowanych metod modyfikujących powierzchnię opracowano metodę pomiaru adhezji pomiędzy materiałem polimerowym a badanym środkiem klejącym (taśma, klej) wykorzystując w tym celu układ uchwytów uniwersalnej maszyny wytrzymałościowej.
EN
Silicone facial prostheses (epitheses, ecto-prostheses, external prostheses) are applied for patients who lost soft and hard tissues in craniofacial area, e. g. eye, ear, nose, due to a surgical treatment; tumour diseases treatment; birth defects or injuries. Prosthetic reconstructions are used when plastic surgery methods are ineffective, or cannot be applied. There are various methods of the ecto-prostheses fastening. Clinical tests and surveys revealed that the first choice for the majority of patients is medical glues. However, such glues can provide only short-time fastening of prosthesis to the damaged area. The work presents results of investigations on adhesion of three kinds of silicone materials fastened to patients' skin with the use of commercial glues and adhesive tapes. In order to improve the materials' adhesion two methods of their surface modification were applied. Influence of a mechanical treatment on the materials' surface was investigated. Effectiveness of the surface chemical treatment i.e. etching of the materials with inorganic acids solutions was investigated. In order to verify effectiveness of the applied surface modification methods a testing method of adhesion between the material and the adhesive agent i.e. adhesive tape or glue was developed. The testing method utilised a universal testing machine.
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