PROCEDURE FOR COATING SCHLAUCHFOERMIGEN PROSTHESES FROM PLASTIC.

The invention concerns a procedure for coating schlauchf5rmigen prostheses from plastic, e.g. container prostheses, with living cells, which are sown as aqueous suspension in physiological solution in the container and deposited due to the force of gravity on whereby the prosthesis stretched filled with the suspension in horizontal direction, those was beschiohtet before with an extracellular Matri× and turned in Sohritten interrupted by joggle breaks around a longitudinal axis wird.

For coating schlauchförmigen prostheses with living cells, in particular with mono layers of epithelial cells, that is usual managing gesohilderte procedures. In practice is shown, dsss auoh at “spacious” variations of the stepper angles for the turn and/or the duration of the joggle breaks an even surface does not have itself by cells on the inner wall of the prosthesis is not reached, but Streifenmuster to form, and the coatings reproducible results bringen.

Task of the invention is it the fact that an even distribution of the cells is always reached in circumferential direction and a complete (konfluente) coating of the prosthesis inner wall; in order to achieve a good “efficiency”, thereby all living and capable of surviving cells from the suspension are as solitaryly as possible werden.

This task is solved with the invention by the application of the following characteristics:

- &lt beginning sowing at a low temperature of; 5°0; - Heating up on for instance Körpertemperatur under continuous rotation for the homogenization of the suspension and prevention of premature, uncontrolled setting of the cells off; - Short one first joggle break of maximally 2 seconds; - Turns around an angle of rotation “= 2 n = + A, whereby n is either zero or a whole positive number and A of one the following Bruchtei [e of =:

4/5, 8/9, 10/9 and 6/5; - up to a total time of some hours: Under gradual increase of the pause period around an amount from 1 to 2 seconds alternating with turns around the selected angle; - Continuous rotation up to sucking the suspension off with that Zeilen.<br do not abgesohiedenen/> The low temperature at the beginning of the Ausssat - i.e. with filling the prosthesis, which consists for example of one into the Gefässprothetik used plastics, with a zellhaltigen, aqueous suspension in physiological solution - ensures that an allocation of the prosthesis with cells does not take place in the preparatory phase for the actual coating steps. Increased after reaching for instance Körpertemperatur e.g. 37°C, on the basis of a first short joggle break, within which surely likewise still no cells set off, the breaks zwisohen the individual turns gradual, gradually, whereby necessarily with each step a break extension does not have to take place. The break extensions had small in each case amounts between 1 to 2 seconds, which can be constant, but. Duroh these sohrittweisen break extensions receive all cells, whose durations of the deposit and/or - for speeds both within a Zellinie and of different Zellinien a whole spectrum form, which can be dependent also on the growth stage of the cells, the possibility abzusetzen.

The criteria for the angles, over those the turns between the breaks take place, guarantee that each wall element is on the average subjected to a same duration at joggle effect in circumferential direction, whereby the indicated borders prevent that it comes to bandings either by overlaps that or by empty spaces between - in the individual breaks setting the cells subjected off - the angle ranges into circumferential direction. The angles of rotation can be extended by integral multiple of 2 =, without the effect of the new procedure is impaired; if necessary such extensions can be even favourably, there thereby a mixing of the cells and thus intermediate homogenization of the suspension effectuation wird.

The angles of rotation correspond to the selected fractions of = and cause in addition that in all Bereiehen cells each AbsetzgeSo schwindigkeit, thus both fast and slowly itself setting off cells, on which whole extent is distributed successively deposited. When particularly favourably thereby angles of rotation of 4/5 = in the experiment or have themselves 6/5 = proved, with des5 nen the joggle range 5 seized during a break on the extent betrãgt.

If the breaks finally reached values of some, for example between 2 and 3 minutes, then very slowly setting off, damaged and dead cells are present in the suspension only itself, which must be removed. Setting the cells off up to sucking this remainder suspension off prevented by continuous turning of the Prothese.<br, still existing in the suspension,/> With advantage the new procedure for it, a prosthesis with a Monoschioht of epithelial cells, serves one or more cell types e.g. from EndotheI cells or a more einoder multi-layer layer to occupy. When using a number of plastics, for example of PU provided with pores, it is zweckmässi9 to submit the prosthesis before any coating of a Aquilibrier treatment with which the outside and which internal surface of the tube as well as the plastic is brought with the environment liquid in the equilibrium, i.e. is for example water-satisfied, over for example the pores to open and permeable to mas0 chen.

In the following the invention becomes closer on the basis a remark example erläutert.

It consists the task a container prosthesis of a tube, their production already in former times described is (EP-A 3 CH 676,195 A5 4 0 323,397) with a einlagigen layer endothelial cells too beschichten.

The BesoEhichtung effected in a likewise already more frûher described treatment chamber (EP-A 0,320,441), in that the prosthesis in longitudinal direction stretched and around a longitudinal axis, which is not necessarily concentric with the prosthesis axle, is swivelling. As rotation drive e.g. a conventional stepping motor serves, attached at its wave the treatment chamber ist.

in well-known way To be opened as mentioned, it is all pores for a prosthesis, as it the remark example is the basis to accomplish appropriately a Aquilibrierungs treatment in order the prosthesis wall with water to be satisfied and. For this pretreatment the completely uncoated prostheses are autoklaviert first in bidestilliertem water and filled then in the treatment chamber Aussenund interior within the range of the prosthesis with a well-known buffer solution HBS-2. HBS-2 is a physiologically buffered salt solution, which admits saltworks” under the name “Hepes buffered is, but additionally with Kalziumund magnesium chloride is modified. This treatment takes place without special thermalstatic precautions with ambient temperature; it consists itself simply of it that the plastic prosthesis filled with the solution stops some days, for example three days, a time, according to the kind of the plastic and after the wall structure of the prosthesis richtet.

Subsequently, the äquilibrierte prosthesis is provided in well-known way on their inside with a pre-coating from an extracellular matrix; such consists as well known of Fibronektin, Kollagen, Laminin, Elastin or Thrombospondin and/or natural or defined mixtures of particulars this and further materials. In the available example for pre-coating Fibronektin is used. The coating takes place after one for the coating of Kulturgef& ssen usual procedures. In detail first the buffer solution of the Äquilibriere treatment is removed from treatment chamber and prosthesis and filled these with a Fibronektin solution; subsequently, into the prosthesis is brought the surrounding outside space of the chamber again buffer solution, around draining the prosthesis wall from the outside ago too verhindern.

After a usual induction period of the Fibronektin solution on the prosthesis inner wall of for example about 45 min with ambient temperature the filled treatment chamber in a refrigerator is stored or in ice water posed to a cooling on for instance 4°C reached ist.

As next step r takes place) unmehr the sowing of the EndotheI cells into the prosthesis coated with Fibronektin. From the cooled treatment chamber Puffedösung and Fibronektin solution are removed and the prosthesis interior also, likewise on 4°C is filled more cooled down, cell suspension. At the low temperature the cells do not show a tendency in the suspension towards setting off. The cell need amounts to in well-known way for instance 10s Zellen/cm2 coating prosthesis surface. Into the outside space of the prosthesis a usual nutritive solution is added, with that it itself for example likewise around physiological Nähr-und cultural solution available in the trade handelt.

After putting in the described way the treated prosthesis and/or the still cooled treatment chamber on on the mentioned Schrittoder positioning engine the actual coating of the prosthesis inner wall with the cells takes place. The first indexing step for it exists 37°C, under continuous rotation of the chamber with 20 to 50 rpm., in warming up the whole Behandiungskammer to for instance Körpertemperatur, i.e. approximately in particular for example with 33 rpm. ; by the continuous turn sedimentations become within the cell suspension verhindert.

If the necessary Körpertemperatur is reached, then the Sedimentieren of the cells begins with a break of 2 second, after which a turn takes place around 6/5; after the turn again a joggle break follows, their duration around approximately 1 to 2 seconds. is extended, before a further turn attaches around the angle mentioned. Alternating with Pausenverlãngerungen around in each case 1 to 2 seconds - which are also only made with each step or after 2 or 3 steps - the prosthesis is always turned at the same angle progressively, until Pausenzeiten are reached by approximately 2 to 3 min. From it an entire coating duration of some hours results, while that is occupied evenly the whole prosthesis inside with endothelial cells, which completely and evenly cover the prosthesis after their propagation. On the whole extent thereby fast and slowly setting off cells are to a large extent evenly distributed, so that an even coating on the whole surface available ist.

After the end of actual coating, little capable of surviving and dead remainder cells setting off very slowly are available in the suspension, as previously mentioned, only itself, which must be sucked off. The treatment chamber becomes from there after coating with a number of revolutions from 1 to 5 U/miri. kontinuiedich turned, around setting these remainder cells off on the coated prosthesis too verhindern.

During this subsequent treatment or immediately after turning the lathe fixture off then the cell-poor suspension with the remainder cells becomes abgesaugt.

The coated prosthesis is subjected now in the same treatment chamber of a conditioning treatment, as it for example in the EP-A 0,320,441 descriptive ist.