Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 25

Liczba wyników na stronie
first rewind previous Strona / 2 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  enkapsulacja
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 2 next fast forward last
PL
Artykuł stanowi przegląd literatury dotyczącej nanokompozytów silseskwioksanowych, jako nośników cząstek bioaktywnych, stosowanych we współczesnej teranostyce (terapii i diagnostyce). Przedstawiono metody syntezy funkcjonalizowanych struktur silseskwioksanowych (POSS), w tym dendrymerów, a także kopolimerów organiczno-nieorganicznych wykorzystywanych do kowalencyjnego wiązania i enkapsulacji cząstek bioaktywnych.
EN
The paper reviews current literature concerning silsesquioxane nanocomposites as potential nanocarriers in contemporary teranostics. It describes synthetic methods leading to functionalized silsesquioxanes (POSS), including dendrimers as well as organo-inorganic copolymers studied as covalent composites and systems for encapsulation of bioactive moieties.
2
Content available remote Wymiana masy w procesie uwalniania składników czynnych z emulsji wielokrotnych
PL
Praca dotyczy badań procesu jednoczesnego uwalniania dwóch substancji aktywnych (ko-uwalniania) z emulsji wielokrotnych o różnych strukturach wewnętrznych. Wyniki potwierdziły dyfuzyjny charakter uwalniania i wykazały, że enkapsulacja drugiej substancji aktywnej zmienia przebieg uwalniania składnika pod-stawowego z jednoetapowego na dwuetapowy i skraca czas potrzebny do jego całkowitego uwolnienia. Badania wymiany masy w procesie jednoczesnego uwalniania dwóch substancji potwierdzają możliwości zastosowań emulsji wielokrotnych, jako bio-nośników kilku składników czynnych.
EN
The paper concerns the process of simultaneous release of two active substances (co-release) from multiple emulsions with different internal structures. The results confirmed a diffusive nature of release and demonstrated that the encapsulation of second active substance changes the release rate of base component from a one-stage to a two-stage and reduces time required to the complete release. Studies of mass transfer during the simultaneous release of two substances confirmed possibility of the use of multiple emulsions as a few compounds bio-carriers.
3
PL
Przedstawiono wyniki badań emulsji wielokrotnych jako bionośników. Badania obejmowały proces enkapsulacji materiału biologicznego mESCs (mysie komórki embrionalne) oraz związków biologicznie czynnych (lek – salol). Analiza procesu enkapsulacji komórek macierzystych wykazała wyższe o 9÷11% stopnie przeżywalności komórek w emulsjach w stosunku do klasycznych stałych nośników matrycowych. W badaniach enkapsulacji leków uzyskano wysokie stopnie enkapsulacji (65÷95%) zależne od struktury emulsji. Wyniki badań potwierdziły możliwość wykorzystania emulsji wielokrotnych jako mikrośrodowiska do przechowywania materiału i substancji biologicznie aktywnych.
EN
Study results dealing with multiple emulsions as biocarriers are presented. The study included encapsulation of biological material (mouse embryonic stem cells) and biologically active compounds (drug - salol). Analysis of stem cell encapsulation showed that the survival rate of stem cells encapsulated in multiple emulsions was 9÷11% higher in comparison to a conventional solid matrix. The drug encapsulation study showed the high encapsulation efficiency (65÷95%) depending on the emulsion structure. The results confirmed the effectiveness of multiple emulsions as a microenvironment for the storage of biological materials and biologically active substances.
4
Content available remote Biomimetyczne matryce do przestrzennej hodowli komórek
PL
Celem badań było opracowanie biomimetycznej matrycy z nośnikiem tlenu do długoterminowej hodowli komórek. Przedstawiono wyniki wstępne obejmujące opracowanie warunków procesu produkcji dwufazowych matryc oraz przeprowadzenie hodowli ludzkich chondrocytów w uproszczonej matrycy. Przeprowadzone badania dowodzą, iż rozmiar produkowanych mikrokapsułek maleje wraz ze wzrostem częstotliwości drgań dyszy. Hodowla komórek CP5 wykazuje konieczność zwiększenia stopnia dotlenienia enkapsulowanych komórek.
EN
The purpose of this work was to develop biomimetic matrix with oxygen carrier for long-term cell culture. Preliminary research results including: microcapsules production conditions and results of human chondrocytes culture in simplified matrices are presented. The size of microcapsules decreases with the increase of nozzle vibration frequency. The chondrocytes culture showed that a greater oxygen supply to the cultured cells is needed.
PL
Przedstawiono możliwość wykorzystania procesu enkapsulacji makrocząstek ferromagnetyka do otrzymywania efektywnych heterogenizowanych katalizatorów metalokompleksowych. W tym celu opiłki żelaza o średniej wielkości ziarna ok. 2 mm pokryto warstwą żywicy epoksydowej funkcjonalizowanej grupami tiolowymi. Pokazano możliwość wykorzystania tego typu nośników w procesie immobilizacji kompleksu palladu. Przygotowane ferromagenetyczne katalizatory wykazały dużą aktywność oraz stabilność w reakcji Hecka oraz w reakcji uwodornienia. Omówiono czynniki wpływające na właściwości katalityczne otrzymanych katalizatorów.
EN
Fe filings were encapsulated in a thiol groups-contg. epoxy resin, used as supports for immobilization of the PdCl2(PhCN)2 catalyst, and then for studying Heck reaction of PhI with CH2=CHCOOMe to trans-PhCH=CHCOOMe and hydrogenation reaction of PhCH=CHCHO to Ph(CH2)3OH. A high conversion of raw materials (71–98%) was achieved in both cases. The catalyst showed high activity and stability in the studied reactions and only small losses of Pd mass were obsd. after multiple use of the catalysts.
PL
Badano wpływ metody atomizacji na trwałość rozpylanych liposomów jako nośników leków inhalacyjnych. Monitorując wielkość emitowanych kropel i stężenie enkapsulowanego trasera wykazano, że silne naprężenia towarzyszące atomizacji w nebulizatorze pneumatycznym silnie destabilizują rozpylany koloid. Korzystniejsze warunki atomizacji panują w inhalatorze typu VM, gdzie nie stwierdzono istotnej dezintegracji liposomów. Wyniki pozwalają na racjonalny dobór techniki atomizacji koloidu tiposomowego do zastosowań inhalacyjnych.
EN
Influence of atomization method on the stability of liposomes being a novel carrier of inhalation medicines was studied. Measuring the droplet size and concentration of encapsulated tracer allowed one to demonstrate that pneumatic nebulization is destructive for liposomes due to high hydrodynamic stresses associated with liquid atomization. The VM nebulizer was shown to be less damaging for liposomes. The results allow for more rational selection of the atomizing device for delivery of atomized liposomes by inhalation.
EN
The Maya Blue is a famous blue pigment developed by pre-Columbian civilizations of Mesoamerica and manufactured there for about thousand years. It was applied for body decoration, important for cruel religious rituals, as well as for artistic paintings, murals, or coloration of ceramics. Its production was abandoned in XVII century and the procedure forgotten. The chemical nature of this blue pigment remained a puzzle for a long time and only in nineteen sixties it was revealed [1, 2] that it is a composite consisting of inorganic matrix (palygorskite) that accommodates molecules of organic dye – indigo. The preparation procedure was rediscovered [3] and the products analogous to classical Maya Blue could be obtained by simple thermal insertion of indigo into palygorskite (and also into sepiolite). However, the nature of chemical interaction between dye and matrix that provides very high resistibility of resulting pigments remains still not satisfactorily explained. The hydrogen bonds or coordinative interaction with matrix cations are taken into an account. Zeolites and other molecular sieves can be efficiently applied as matrices for pigments similar to Maya Blue. The coloration and other properties of pigments can be considerably changed by initial modification of zeolites with various cations, what supports an important role of complexes formed by dye molecules and zeolite cations. On the other hand, the zeolite-like materials AlPO4 as well as to some extent mesoporous silica (with some contribution of micropores) lacking any cations are also efficient matrices for pigments analogous to Maya Blue. Not only indigo, but also indigo derivatives (leucoindigo, thioindigo, indigo carmine) could be embedded inside the molecular sieves. The thermal insertion as well as crystallization of zeolites from gels supplemented with respective dye can be used for pigment synthesis. It is interesting that role of matrix can be also played by representative of novel MOF family of the molecular sieves.
EN
The microencapsulation of PCMs involves enclosing them in thin and resilient polymer shells so that the physical state of this material can be changed from solid to liquid and back again within the shells. The utilization of microencapsulated PCMs in textile goods is advantageous since the encapsulation prevents PCM dispersion in the structure, reduces evaporation and reaction of PCMs with the outside environment, provides an increased heat-transfer area and a constant volume, and allows an easy application without affecting other textile properties and a normal fabric-care. In this paper the structural composition, preparation methods and characteristics of the microcapsules are discussed. Microencapsulation is a very time-consuming and complicated chemical process, running over several stages, making the microPCMs very expensive. In addition to microencapsulation of PCMs numerous attempts have been made to contain organic PCMs in certain macrostructures such as polymer matrices or porous materials (silica powder, perlite, expanded graphite). These containment structures are known as form-stable composite PCMs. The preparation and characterization of novel form-stable phase change material (PCM) is presented.
10
Content available remote Nowe metody syntezy pigmentów ultramarynowych z użyciem zeolitów
EN
The natural ultramarine (lazurite, lapis lazuli) has been known and valued since the ancient times as semiprecious gem applied for jewelry, artistic works, decoration and painting. In Middle Ages it was used as excellent, but very expensive pigment. At the beginning of the nineteenth century a method of synthesis of artificial ultramarine has been discovered and it soon became a common inexpensive commercial product applied mostly for production of paints and as an optical brightener. The procedure included heating of the substrate mixtures (kaolin, sulfur, sodium carbonate, reducing agent) in kilns at high temperature (800°C). The technology of ultramarine production has not been substantially changed up to now, whereas the law regulations concerning environment protection imposed in the twentieth century could not accept a serious air pollution (SO2, H2S) always accompanying the production process. Therefore, searching for novel, environmentally friendly procedures becomes challenging. Ultramarine is an aluminosilicate with sodalite structure that contains sulfur anion-radicals (mostly •S3-) combined with Na+ cations embedded inside ?-cages. The sulfur radicals play a role of chromophores (•S3- blue, •S3- yellow). Sodalite is a zeolite and the sodalite units (?-cages) are constituents of structure of several zeolites (LTA, FAU, LTN, EMT). The use of zeolitic structures for encapsulation of sulfur anion radicals appeared very promising. The direct introduction of sulfur radicals from aprotic solutions of oligosulfides [27] was not successful but the thermal treatment of zeolites mixed with sulfur radical precursors (NaSn, S + alkalis) resulted in colored products analogous to ultramarine [24-26, 30, 31]. Zeolites A seem the most useful for preparation of sulfur pigments but other zeolites can be applied as well. The products of various colors (yellow, green blue and sometimes pinky) and shades can be obtained by choosing appropriate zeolite, radi-cal precursor, kind and content of alkaline cation in the initial mixture, temperature (400-800°C) and time of treatment. It was found that zeolite structure can be maintained upon the thermal treatment or it can be transformed (mostly towards SOD) under highly alkaline thermal treatment. The sulfur radicals can also be embedded inside smaller than ?-cages (e.g. CAN) which favors a generation of smaller radicals (i.e. •S2-) [39-42]. It is also possible to incorporate the sulfur compounds into zeolites during their crystallization and then a generation of radical upon heating. The sulfur pigments based on non aluminosilicate matrices (e.g. AlPO4-20) can be also obtained [38, 53]. Generally use of zeolites allows to obtain ultramarine-like pigments with broad range of colors under much milder than conventional conditions and with much lower emission of polluting agents.
EN
In the paper a new material with optional mechanical/rheological properties has been introduced. It is built on the basis of loose grains encapsulated in a hermetic sleeve, where in the next step so called underpressure is generated. This increases internal frictional forces acting between constituent elements (grains) and in the global scale causes stiffening of the granular system. Increasing of internal underpressure value causes non-linear changes in mechanical properties of the system. In this paper basic rheological experimental results are presented and grain's material influence on global physical properties is discussed.
EN
This work deals with new "smart systems" that are based on granular materials. These systems consist of a tight flexible sleeve, which is filled with a granular material. The air is then pumped out of the sleeve, causing underpressure, compressing the granules and so making the system more rigid and changing its damping characteristics. This allows for quick, easy, and inexpensive controls of the damping and stiffness of such systems. The aim of this paper is to present the experimental results of uniaxial tests of a sleeve filled with granular materials. These results support the modeling of such a system filled with a granular material using the Bodner-Partom viscoplastic constitutive law.
13
Content available remote The biocompatibility of membranes for immunoisolation
EN
The assessment of biocompatibility of systems consisting of a host, permiselective membrane and a biological material, encapsulated within may be standardized for biological material immunoisolation purposes. The procedures for evaluation of the membrane non-toxicity against the biological material, the membrane physical and chemical stability post implantation and the biomaterial ability to perform with the host are presented.
EN
Encapsulation of bacteria in a semipermeable polymer membrane gives a lot of technological possibilities. Our aim was to evaluate the performance of bacteria encapsulated in hollow fibers when treated with chosen antibiotic. The antibiotic application may cause release of biologically active substances for which production the bacteria may be genetically modified. The encapsulated in HF bacteria Escherichia coli transfected with pQE-GFP (green fluorescent protein) plasmid were incubated with addition of gentamycin or tetracycline. The encapsulated in hollow fibers E. coli culture with addition of tetracycline proves the tetracycline impact on the bacteria viability increasing the necrotic bacteria share. Polypropylene modified membranes allow to avoid permeation of the bacteria through the membrane wall. E. coli encapsulated in HF may be used in future, in systems releasing the therapeutic factor.
EN
Presented paper is an initial probe of adaptation of the new "smart" structures, built on the basis of a loose material, encapsulated in a thigh sleeve, where in the next stage, so called underpressure has been generated, for the active (semi-active) damping of vibrations.
EN
Part I presents a basic overview of the microencapsulation science. The encapsulation techniques, structure of microcapsules and their and properties, the fixation of microcapsules to textiles are discussed. Some recent applications of microencapsulation technology in textile finishing are highlighted. Examples of each technology are described.
EN
The part II is concerned with the control release of active substances such as antimicrobials, fragrances and dispersive dyes.
PL
Technologie wykorzystujące możliwości enkapsulacji polimerów i wynikające stąd nowe właściwości są przedmiotem prac badawczych na całym świecie. Wykorzystanie możliwości precyzyjnego reagowania biocydów w mikrosferach polimerowych umieszczonych w podłożu tekstylnym otwiera nowe kierunki medycznych zastosowań wyrobów włókienniczych. Referat stanowi przeglądowy materiał dotyczący wytworzenia materiału włókienniczego o właściwościach bioaktywnych z uwzględnieniem kolejnych elementów decydujących o uzyskaniu wymaganego efektu przy wykorzystaniu techniki enkapsulacji biocydu. Na podstawie własnych doświadczeń omówiono sposoby określania parametrów mających wpływ na aktywność biocydu i kinetykę jego uwalniania na nośniku włókienniczym.
EN
Technologies based on polymer encapsulation - which offers new properties acquisition, are the subject of research and development works in the world. Using the capability of precise reacting of biocides in micro-spheres located in textile substrate opens new directions for medical applications of textile fabrics. This paper is a survey of manufacturing methods of textile materials having bio-active properties. Special focus is put on consecutive elements deciding upon desired effect acquisition, applying biocide encapsulation technique. Based on our own experience, the methods of determining the parameters influencing biocide activity and release kinetics of biocide on textile substrate have been described.
EN
Presented work concerns problems connected with a new "smart material". It is a granular structure, built basing on a loose material, placed in a tight encapsulation, where in a next stage so called underpressure has been generated. The main aim of this paper is to establish the general dependence between grain's material and an elastic range of deformations (proof stress), in uniaxial experiments, of specially performed granular samples, for a wide range of applied underpressure values.
EN
Presented work concerns problems connected with a new "smart structure". It is a granular structure, built basing on a loose material, placed in a tight encapsulation, where in a next stage so called underpressure has been generated. The main objective of this paper is to establish the general dependence between grain's material and stiffness (Young modulus) values, for a wide range of applied underpressures.
first rewind previous Strona / 2 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.