{"id":29679,"date":"2024-08-23T11:23:05","date_gmt":"2024-08-23T09:23:05","guid":{"rendered":"https:\/\/fgu.antstudio.dev\/?post_type=vyzkumny-projekt&p=29679"},"modified":"2024-08-31T16:31:30","modified_gmt":"2024-08-31T14:31:30","slug":"creation-of-new-tissue-replacements","status":"publish","type":"vyzkumny-projekt","link":"https:\/\/fgu.cas.cz\/en\/research-project\/creation-of-new-tissue-replacements\/","title":{"rendered":"Creation of new tissue replacements"},"content":{"rendered":"

The general principle of the creation of tissue replacements, artificial material containing as an analogue<\/span> of extracellular matrix (ECM) and the cell<\/strong><\/h2>\n

The material thus constructed tissue replacement is a resorbable, ie. will be gradually eliminated and replaced with regenerated tissue<\/span>. So<\/span> artificial material in modern tissue engineering becomes not permanent replacement of damaged tissues, but only a temporary carrier cells inducing the regeneration of damaged tissue. The concentration and distribution of adhesion oligopeptides, i.e. ligands for adhesion cell receptors, regulates the number and the spreading area of the adherent cells. The amino acid composition of the oligopeptide then determines the type of the\u00a0adhered cells. E.g. the REDV sequence (Arg-Gly-Asp-Val) is preferred by endothelial cells<\/span>, the sequence\u00a0VAPG (Val-Ala-Pro-Gly) by the smooth muscle cells, the sequence\u00a0 KRSR (Lys-Arg-Ser-Lys) by the osteoblasts and the sequence\u00a0 RGD (Arg-Gly-Asp) is for all cell types.<\/p>\n

 <\/p>\n

In our studies we used the mentioned<\/span> model for tissue engineering of blood vessel wall. The polymeric material with oligopeptid ligands containing RGD (the ligands for the\u00a0integrin adhesion receptors) was seeded with vascular smooth muscle cells, which are the most abundant cell type of the vessels, providing especially their contractility.<\/p>\n

 <\/p>\n

\"-\"<\/p>\n

 <\/p>\n

In the culture\u00a0on the\u00a0polylactide (PDLLA<\/strong>) supplemented with the medium containing fetal\u00a0bovine\u00a0serum are the smooth muscle cells (HSB) normally spread and\u00a0have a polygonal shape, similarly as is in the cultures from the standard polystyrene cultivation dishes. The cells have a well-formed<\/span>\u00a0focal adhesion plaques (arrowed),i.e. group of adhesion receptors and other associated molecules, through which the cells adhere to the substrate<\/em>. Cell adhesion to the polylactide is mediated by spontaneous adsorption of proteins from the serum (especially<\/span> vitronectin and fibronectin), which is a cell adhesion receptors bind.<\/em><\/p>\n

 <\/p>\n

If the polylactide chain copolymerized with polyethylene oxide chains (PEO-PDLLA), the surface of the material\u00a0becomes strongly hydrophilic and mobile. Mobility can be imagined such as that chain PEO “flutter” in the culture medium, like grass or grain ropes in the wind. This\u00a0eliminates adsorption of proteins mediating the adhesion of cells from serum in the culture medium and the cells can not adhere to the substrate. They have a spherical shape and the lack of cell-adhesion material is trying to compensate with the cell-cell adhesion, i.e. by creating clusters.<\/span><\/p>\n

\n
\n
\n
<\/div>\n<\/div>\n<\/div>\n<\/div>\n

If some chain<\/span> of PEO (in this case 5 or 20%) fitted<\/span> with adhesion oligopeptides containing RGD (PDLLA-PEO-5% GRGDSG or PDLLA-PEO-20% GRGDSG), cell adhesion, their distribution on the substrate and formation of focal adhesion plaques are restored. The concentration of adhesion ligands affected the surface spreading of cells and the number of adherent cells in the sense that the spreading area was higher at lower concentrations of ligands, whereas the number of cells was proportional to the concentration of ligands.<\/em><\/p>\n

 <\/p>\n

This principle of the creation of<\/span> tissue replacement could be used in general for engineering a wide range of tissues, including bone tissue. Polymeric materials are generally less suitable for replacements of bone tissue for its poor mechanical<\/span> properties. Therefore we attempted to reinforce polymers with harder materials such as nanoparticles of diamond or ceramic materials, e.g. hydroxyapatite. These nanoparticles represent an inorganic (mineral) component of natural bone tissue. Polymers are used in the form of nanofibres, which mimicthe organic components of natural bone tissue, e.g. collagen fibers.<\/p>\n

This principle of the creation of<\/span> tissue replacement could be used in general for engineering a wide range of tissues, including bone tissue. Polymeric materials are generally less suitable for replacements of bone tissue for its poor mechanical<\/span> properties. Therefore we attempted to reinforce polymers with harder materials such as nanoparticles of diamond or ceramic materials, e.g. hydroxyapatite. These nanoparticles represent an inorganic (mineral) component of natural bone tissue. Polymers are used in the form of nanofibres, which mimicthe organic components of natural bone tissue, e.g. collagen fibers.<\/p>\n

 <\/p>\n

Potential substitutes of bone tissue based on polymer nanofibers reinforced with organic particles<\/strong><\/h2>\n

 <\/p>\n

\"-\"<\/p>\n

 <\/p>\n

\"-\"<\/p>\n

 <\/p>\n

Nanofibrous\u00a0membranes\u00a0from\u00a0 the\u00a0copolymer of lactide and glycolide (PLGA) were prepared by the electrostatic spinning method\u00a0in the NanospiderTM device (Elmarco Ltd.). Some\u00a0membranes have been\u00a0loaded with diamond nanoparticles of diamond, admixed into\u00a0the PLGA\u00a0solution before spinning (PLGA-ND). The final concentration of nanodiamond in PLGA was about 23 wt%. Human osteoblasts line MG 63 adhered and grew on both types of\u00a0scaffolds similary, but the PLGA-ND membranes showed higher mechanical resistance, as demonstrated by rupture tests of load and deflection of rupture probe at failure.<\/em><\/p>\n

Positive\u00a0results were also achieved with nanofibrous\u00a0membranes\u00a0fabricated from\u00a0the\u00a0polylactide (PLLA)\u00a0loaded with\u00a05 and 15% by weight of hydroxyapatite (HA). The presence of HA supported the growth of osteoblasts line MG 63, and also their osteogenic differentiation which manifested a higher concentration of osteocalcin in these cells<\/em>:<\/p>\n

 <\/p>\n

\"-\"<\/p>\n

 <\/p>\n

Pa\u0159\u00edzek M<\/strong>, Douglas TEL, Novotn\u00e1 K<\/strong>, Kromka A, Brady MA, Renzing A, Voss E, Jaro\u0161ov\u00e1 M, Palatinus L, Tes\u00e1rek P, Ryparov\u00e1 P, Lis\u00e1 V<\/strong>, dos Santos AM, Ba\u010d\u00e1kov\u00e1 L<\/strong>: Nanofibrous poly(lactide-co-glycolide) membranes loaded with diamond nanoparticles as promising substrates for bone tissue engineering. Int J Nanomed<\/strong> 7: 1931-1951, 2012<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

The general principle of the creation of tissue replacements, artificial material containing as an analogue of extracellular matrix (ECM) and the cell The material thus constructed tissue replacement is a resorbable, ie. will be gradually eliminated and replaced with regenerated tissue. So artificial material in modern tissue engineering becomes not permanent replacement of damaged tissues, […]<\/p>\n","protected":false},"author":1,"template":"","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"oddeleni":[151],"poskytovatel":[],"stav-projektu":[209],"class_list":["post-29679","vyzkumny-projekt","type-vyzkumny-projekt","status-publish","hentry","oddeleni-biomaterials-and-tissue-engineering","stav-projektu-current-projects"],"acf":[],"_links":{"self":[{"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/vyzkumny-projekt\/29679","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/vyzkumny-projekt"}],"about":[{"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/types\/vyzkumny-projekt"}],"author":[{"embeddable":true,"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":0,"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/vyzkumny-projekt\/29679\/revisions"}],"wp:attachment":[{"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/media?parent=29679"}],"wp:term":[{"taxonomy":"oddeleni","embeddable":true,"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/oddeleni?post=29679"},{"taxonomy":"poskytovatel","embeddable":true,"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/poskytovatel?post=29679"},{"taxonomy":"stav-projektu","embeddable":true,"href":"https:\/\/fgu.cas.cz\/en\/wp-json\/wp\/v2\/stav-projektu?post=29679"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}