MARCO REFERENCIAL, MARCO CONCEPTUAL E HIPÓTESIS DE LA INVESTIGACIÓN
2.1.6 LOS CONTEXTOS DE ENSEÑANZA APRENDIZAJE UNIVERSITARIOS
Electron microscopical assessment of carbon fibre plugs with associated chondrocvtes. Scanning electron micrographs of sections of graft tissue of isolated rabbit articular chondrocytes cultured in vitro within a carbon fibre meshwork after 3 weeks culture are shown in Fig. 3.2.3.a.-d. The chondrocytes within the carbon fibre plug produced matrix which was laid down against and between the carbon fibres (Fig 3.2.3.a.+b.). The fine fibrillar nature of the synthesised matrix is shown in Fig. 3.2.3.C. Note how chondrocytes attach to the individual carbon fibres (Fig. 3.2.3.d.).
Electron microscopical assessment of collagen gel plugs with associated chondrocvtes. Transmission electron micrographs of sections of graft tissue of isolated rabbit articular chondrocytes on a collagen gel plug after 7 days in vitro culture are shown in
Fig. 3.2.3.e.-h. The collagen gel cultures were examined after 7 days in vitro and not after 21 days since most comparable literature on cells cultured on or within a collagen gel gives results during the first week in vitro. Similar to the results described by Gibson et al., (1982) chondrocytes cultured within a collagen gel maintain a rounded-polygonal configuration, in addition to some elongated cells. Ultrastructurally, the cells show features of active synthesis, for example, abundant, distended rough endoplasmatic reticulum, mitochondria and Golgi vesicles (Fig. 3.2.3.e.-h.).
Electron microscopv assessment of hydrogel PC 97 plugs with associated chondrocvtes. Scanning electron micrographs of sections of graft tissue of isolated rabbit articular chondrocytes within a hydrogel plug after 21 days in vitro culture are shown in Fig. 3.2.3.L-1. The structure of the hydrogel PC 97 is shown in detail in Fig. 3.2.3.i. The pore size varied from 20 |im to 38 |xm and some cellular ingrowth into these pores was observed, although the chondrocytes at the margin did not migrate very far into the hydrogel PC 97 (Fig. 3.2.3.k.4-l.).
As described above the surrounding synovial and capsular tissues were examined histologically for presence of graft material and the reaction of the synovial and capsular tissues to hydrogel PC 97. Further examination using scanning electron microscopy was carried out.
In order to confirm my interpretation of the wax sections (3.2.2.3. above), two sections were processed in tandem for wax and scanning electron microscopical examination, respectively. One section was stained with haematoxylin-eosin, whilst the other was dehydrated up to 70% alcohol and air-dried. Subsequently, the air-dried section was processed as described for the hydrogel PC 97 plug in chapter 2.2.3. The two tissue sections were compared and the foreign material was found (Fig. 3.2.3.m.-o.). Because of the similarities in physical structure and pore size of the foreign material in the
synovial and capsular tissues (Fig. 3.2.3.p.) and of the hydrogel PC 97 (Fig. 3.2.3.i.), it was concluded that the foreign material was hydrogel PC 97.
Fig. 3.2.3.a. Scanning electron micrograph of the interaction between chondrocyte and carbon fibre after 3 weeks in vitro culture (x 150). The chondrocytes within the carbon fibre plug (CF) produced matrix which was laid down against the carbon fibres.
Fig. 3.2.3.b. Scanning electron micrograph of the interaction between chondrocyte and carbon fibre after 3 weeks in vitro culture (x 240). The chondrocytes within the carbon fibre plug (CF) produced matrix (M) which was laid down between the carbon fibres.
Fig. 3.2.3.C. Scanning electron micrograph of the interaction between chondrocyte and carbon fibre after 3 weeks in vitro culture (x 2 500). The fine fibrillar nature of the produced matrix (M) is shown (CF = carbon fibre).
Fig. 3.2.3.d. Scanning electron micrograph showing attachment of the chondrocyte to the individual carbon fibre (CF) (x 2 500).
Fig. 3.2.3.e. Transmission electron micrograph of chondrocytes cultured on a collagen gel after 7 days in vitro culture (x 4 000). Three chondrocytes are shown with little matrix.
Fig. 3.2.3.f. Transmission electron micrograph of chondrocytes cultured on a collagen gel after 7 days in vitro culture (x 10 000). More detailed view of the chondrocytes showing some organelles: mitochondria (M), lipid drops (D) and vacuoles (V). (N = nucleus).
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% F i ^ . 3 . 2 . 3 . C . Kig 5 pm Fig. 3.2.3.e. F i g . 3 . 2 . 3 . 1 ) . K i g . 3 . 2 . 3 . ( 1 . l.O iT m Fig. 3 . 2 . 3.r.Fig. 3.2.3.g. Transmission electron micrograph of chondrocytes cultured on a collagen gel after 7 days in vitro culture (x 37 500). Ultrastructure of the cells showed the presence of endoplasmatic reticulum (E). (N = nucleus).
Fig. 3.2.3.h. Transmission electron micrograph of chondrocytes cultured on a collagen gel after 7 days in vitro culture (x 18 000). Ultrastructure of the cells showed widened cistemae of endoplasmatic reticulum (E) and mitochondria (M). (N = nucleus).
Fig. 3.2.3.i. Scanning electron micrograph of section of a hydrogel PC 97 plug prior to use (x 2 500). The structure of the hydrogel PC 97 (HG) can be seen in more detail. The pore size varies from 20 pm to 38 pm (D = dextrin).
Fig. 3.2.3.k. Scanning electron micrograph of section of graft tissue of isolated rabbit articular chondrocytes within a hydrogel plug after 21 days in vitro culture (x 550). This showed some ingrowth of the chondrocytes into the pores of the hydrogel (S = surface of the graft tissue).
Fig 3.2.3.I. Scanning electron micrograph of section of graft tissue of isolated rabbit articular chondrocytes within a hydrogel plug after 21 days in vitro culture (x 500). This gave more detailed view of the surface layers (S) of the graft tissue showing the presence of matrix at the margins of the hydrogel PC 97 plug.
Fig. 3.2.3.m. Photograph of wax-embedded section of synovial and capsular tissues at 3 months after implantation of hydrogel PC 97 plug (haematoxylin-eosin, x 150). A foreign material (hydrogel PC 97) was found.
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F i g . 3 . 2 . 3 . i . F i g . 3 . 2 . 3 . R .Fig. 3.2.3.Ü. Scanning electron micrograph of wax-embedded section of synovial and capsular tissues at 3 months after implantation of hydrogel PC 97 plug (x 125). This section was similar to the one shown in Fig. 3.2.3.m., but it was processed for SEM and hydrogel PC 97 (see arrows) was found.
Fig. 3.2.3.O. Scanning electron micrograph of wax-embedded section of synovial and capsular tissues at 3 months after implantation of hydrogel PC 97 plug (x 1 000). It showed the porous structure of the hydrogel PC 97 present in the synovial and capsular tissues.
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