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vol. 15
97 - 106
EN
The aim of the study was to develop preparation methods of porous chitosan structures and to investigate their morphological properties as well as the kinetics of model substance release (salicylic acid). Chitosan scaffolds were generated using the liophylisation method and the systems obtained were saturated with hydroxyapatite and salicylic acid. Microscopic investigations (optical and electron microscopy) were carried out to examine the morphology of structures and water vapour sorption isotherms were determined to define the influence of hydroxyapatite on the system sorption ability. Additionally, the kinetic curve for the model substance release process (the process of the 1st order) was determined.
EN
Regenerative medicine is focusing on searching for stem cells, which can be efficiently and safely used for regeneration of damaged tissues and organs. Pluripotent stem cells would be ideal for this purpose. It is because they have the ability to differentiate into cells of all three germ layers (ecto-, meso- and endoderm). One of the sources of their isolation are embryos. For many years, they are made unsuccessful attempts to use of very controversial embryonic stem cells that are isolated from embryos. So strong ethical controversy forced scientists to look for other, undoubted ethically, sources of pluripotent stem cells. Induced pluripotent stem cells are proposed, as a more promising alternative to cells isolated from embryos. Unfortunately, both embryonic stem cells and induced pluripotent stem cells tend to genetic instability leading to the formation of teratomas. In parallel studies scientists try to use of stem cells isolated from adult tissues (e.g. bone marrow cells or adipose tissue) in the regeneration of parenchymal organs. Unfortunately, there is no convincing evidence for most of these cells that can regenerate damaged parenchymal organs. Regenerative medicine more frequently is employed in the otorhinolaryngological therapies. More and more researchers’ efforts are put into the development of an effective method of stimulation (in vitro) of pluripotent stem cells isolated from adult tissue for differentiation of the renewable progenitor stem cells which can keep their potential after transplantation into the recipient (e.g. in the treatment of imbalances or hearing loss). Moreover, there are promising methods for employing of the stem cells potential in tissue engineering as they are more effectively introduced as a clinical therapies.
EN
As a result of the removal of cells from human allogeneic dermis, a collagen scaffold is obtained, which can be populated de novo with autologous/allogeneic skin cells and transplanted onto the area of skin loss. The optimal method for production of acellular dermal matrices (ADM) has been selected. Three female patients (a mean age of 54 years) were subjected to the transplantation of either autologous or allogeneic keratinocytes and fibroblasts into the holes of acellular dermal matrix (ADM) mesh graft. The method for burn wound treatment based on the use of a viable dermal-epidermal skin substitute (based on ADM and in vitro cultured fibroblasts and keratinocytes) may be the optimal method of burn treatment.
EN
Creating innovative methods of treatment and regeneration of damaged tissues or organs is a key challenge of the twenty-first century. The aim of this study was to determine the possibility of producing and characterising the properties of self-organising chitosan hydrogels prepared with the use of chitosan lactate/chloride and disodium hydrogen phosphate dodecahydrate as a cross-linking agent. The structure and supramolecular architecture of the biomaterials were evaluated by Fourier-transform infrared spectroscopy and polarised optical microscopy. Biological studies assessed cytotoxicity by contact with a human colon adenocarcinoma cell line. The colourimetric resazurin assay showed that the obtained chitosan hydrogels are non-cytotoxic materials. Thus, self-organising biomaterials hold great promise for application in tissue engineering.
EN
Collagens are a family of fibrous proteins which are a major component of the extracellular matrix (ECM) in animal organisms. These proteins are found in most tissues and organs (bones, cartilages, skin, ligaments, tendons, corneas). The main functions of collagens include the maintenance of structural integrity, elasticity and tensile strength of the connective tissue. Macromolecules from the collagen family are characterized by a unique structure rich in e.g. glycine, proline and hydroxyproline. The collagen structure consists of three left-handed polypeptide chains which are coiled around each other forming a right-handed rope-like super helix. This structure is stabilized by the presence of interstrand hydrogen bonds. To date, 29 types of collagen have been isolated and described. They differ from each other in structure, functions, and body distribution. Research development has allowed us to understand the structure and properties of native collagens which has resulted in the production of artificial collagen fibrils used in nanotechnology and biomedicine. Collagen materials are considered to be the most useful biomaterials in medicine
PL
Kolageny to rodzina białek fibrylarnych, będąca głównym składnikiem macierzy zewnątrzkomórkowej organizmów zwierzęcych. Białka te występują w większości tkanek i narządów, m.in. w kościach, chrząstkach, skórze, więzadłach, ścięgnach, rogówce. Podstawowym ich zadaniem jest utrzymanie integralności strukturalnej i sprężystości tkanki łącznej oraz jej wytrzymałości na rozciąganie. Kolageny charakteryzują się unikatową strukturą bogatą w aminokwasy, takie jak glicyna i prolina oraz hydroksyprolina. Głównym elementem struktury kolagenów są 3 lewoskrętne polipeptydowe łańcuchy, nawijające się wokół siebie i tworzące prawoskrętną konformację liny superhelisowej, która utrzymywana jest dzięki obecności wiązań wodorowych. Dotychczas udało się wyizolować i opisać 29 typów kolagenów charakteryzujących się odmienną strukturą, funkcją oraz występowaniem w organizmie. Rozwój technik badawczych umożliwił poznanie struktury i właściwości naturalnych białek kolagenowych, co z kolei zaowocowało produkcją syntetycznych włókien kolagenowych, wykorzystywanych w nanotechnologii czy biomedycynie. Materiały kolagenowe zaliczane są do najbardziej użytecznych biomateriałów ze względu na takie właściwości, jak minimalna toksyczność, niska antygenowość, wysoka biozgodność oraz biodegradowalność.
EN
In the contemporary medicine, undifferentiated progenitor cells of various origin and various degree of plasticity have become highly promising. Their most abundant, renewable and uncontroversial sources are placental tissues and umbilical blood. The only epithelial cells in this group come from the amnion which is used as a whole as an allogenic biological dressing. They have a range of unusual properties, such as the relative lack of histocompatibility antigens, plasticity (enabling their differentiation into a number of epithelial and mesenchymal cells) and the lack of neoplastic capacity. Amniotic epithelial cells are the only epithelial cells of the placenta. It is believed that they retain their progenitor (pluripotent) properties even in term pregnancies. This probably results from the fact that they omit the differentiation that accompanies gastrulation. Such features are typical of all placental cells which differ from amniotic epithelial cells only in their non-epithelial origin. In culture conditions, amniotic epithelial cells are characterized by a considerable plasticity: they can be stimulated to differentiate into adipocytes, chondrocytes, osteocytes, myocytes, cardiomyocytes, neurocytes, pancreatic cells and hepatocytes. To date, however, the attempts to direct their development towards the epidermis have not been successful. Obtaining multilayer epidermis in amniotic epithelial culture would be of considerable importance for tissue engineering of biological dressings. Amniotic membranes have been used for this purpose for many years, but because of their complex structure and metabolic requirements, they do not heal but dry up when applied to the wound. Some reports, however, indicate that the epithelium isolated from the amnion could be able to heal thus being suitable for allogenic grafts.
PL
Współczesna medycyna coraz większe nadzieje pokłada w niezróżnicowanych komórkach progenitorowych różnego pochodzenia i o różnym stopniu plastyczności. Ich najbardziej zasobnym, odnawialnym i niekontrowersyjnym źródłem wydają się tkanki łożyska i krew pępowinowa. Jedyne w tej grupie komórki nabłonkowe pochodzą z owodni, wykorzystywanej często w całości jako allogeniczny opatrunek biologiczny. Mają one szereg niezwykłych cech, takich jak względny brak ekspresji antygenów zgodności tkankowej, plastyczność (umożliwiająca różnicowanie w cały szereg komórek nabłonkowych i mezenchymalnych) oraz brak zdolności do nowotworzenia. Komórki nabłonka owodni są jedynymi nabłonkowymi komórkami łożyska. Uważa się, że nawet w donoszonej ciąży zachowują właściwości progenitorowe (pluripotencjalne). Wynika to prawdopodobnie z faktu, iż pomijają różnicowanie towarzyszące gastrulacji. Cechy te przejawiają zresztą wszystkie komórki łożyska, różniące się od komórek nabłonka owodni jedynie nienabłonkowym pochodzeniem. W hodowli komórki nabłonka owodni charakteryzują się dużą plastycznością: ulegają stymulacji do różnicowania w kierunku adypocytów, chondrocytów, osteocytów, miocytów, kardiomiocytów, neurocytów, komórek trzustki i hepatocytów. Dotychczas nie udało się jednak skierować ich rozwoju w kierunku naskórka. Uzyskanie nabłonka wielowarstwowego w hodowli komórek nabłonka owodni miałoby ogromne znaczenie dla inżynierii tkankowej opatrunków biologicznych. Błony owodniowe wykorzystywane są w tym celu od wielu lat, jednak wskutek złożonej struktury i wymagań metabolicznych nie ulegają wgajaniu – wysychają po położeniu na powierzchni rany. Niektóre badania wskazują natomiast, że nabłonek izolowany z owodni mógłby się wgajać, nadawałby się zatem do allogenicznych przeszczepów.
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