Objective To verify the technics of inactivating/removing virus in collagen sponge derived from bovine Achilles tendon. Methods Possible pathogen species were determined according to the raw material of bovine Achilles tendon used in production, then vesicular stomatitis virus (VSV), theiler’s mouse encephalomyelitis virus (TEMV), pseudorabies virus (PRV), and simian vacuolating virus 40 (SV40) were selected as indicator virus. Virus suspension was prepared in accordance with Technical Standard for Disinfection. 60Co radiation 25 kGy of collagen sponge was determined as inactivating/removing virus process according to the analysis of the manufacture process, the virus inactivation/removal effect was verified by the measurement of median tissue culture infective dose (TCID50) and showed by virus reduction factor (sample average values of numerical difference before and after processing). Results Reduction factors of VSV, TEMV, PRV, and SV40 after 60Co radiation 25 kGy were 5.646, 4.792, 5.042, and 5.292 logTCID50/0.1 mL (logs), respectively. Reduction factor of each indicator virus was greater than 4 logs, showing that 60Co irradiation 25 kGy can effectively inactivate and remove viruses. Conclusion 60Co radiation 25 kGy of collagen sponge derived from bovine Achilles tendon can be used as the technics of inactivating/removing virus during the preparation process of collagen sponge to guarantee the safety of the product.
Objective To make an experimental research of the tissue engineered rat submandibular glands (SMG) cells growing on a collagensponge scaffold under an optimal culture condition. Methods The Wistar rat (8 days old) SMG cells of the second generation were seeded onthesurface of the collagen sponge scaffold (5 mm×5 mm×2 mm) and were cultured under a physiologically optimal condition for 3 weeks. At 1, 2 and 3 weeks, the cultured cells were observed on their shapes and structures by the histological examination and the scanning electron microscopy. The cultured cells underwentthe immunohistochemistry research (the cytokratin 813,CK8.13;αsmooth muscular actin,αSMA) staining performed at 3 weeks of the culture, and the amylaseactivity analysis (the Amano method) performed at 1 day, 1, 2 and 3 weeks of the culture for an evaluation on the secretion function of the cells; the ultrastructures of the cells were also observed by the transmission electron microscopy for an identification of their origins. Results The observatio n under the scanning electron microscope showed that at 1 week after the cellseeding, the seeded cells were attached to the collagen sponge scaffold surface, with no cell process formed; at 2 weeks the cells increased, with formation of the cell process that was anchored on the collagen sponge scaffold surface; and at 3 weeks, the scaffold surfaceattached cells increased, with formation of thefiliform fibers in the surface layer of the cells. The immunohistochemistry staining showed that the cultured epithelial cells of SMG were bly positive for the specific antibody of CK8.13, and the myoepithelial cells were positive forthe specific antibody of αSMA. The transmission electron microscopy showed that in the surface layer of the cultured epithelial cells of SMG the microvilli,plasm crease, and zymogen granules were observed, with a big and ovalshaped nucleus in the cell, and mitochondria and rough endoplasmic reticulum in the cytoplasm of the cell. The amount of amylase secreted by the cells cultured with thecollagen sponge scaffolds increased at a different degree with an extension of the culturing time. Conclusion The collagen sponge has a satisfactory cell compatibility, and the SMG cells cultured with this kind of collagen sponge can keep their abilities of proliferation and differentiation and theirfunction of secretion. Therefore, this kind of cultured SMG cells can be used as the tissueengineered cells seeded in the scaffold.
OBJECTIVE: To validate the hemostatic properties of collagen sponge made in China. METHODS: The experimental model of superficial cut of liver was established in 20 Sprague-Dawley adult rats, which were divided into two groups randomly. Collagen sponge or gelatin sponge was used to cover the cut respectively. Hemostatic result was observed. Afterwards, standard liver trauma model by resection left front liver lobe was made, wound was treated with collagen sponge or gelatin sponge respectively. Hemostatic result was observed. Concurrent hemostatic time and bleeding amount were noted. At 7, 14 and 20 days after operation, intra-abdominal adhension, infection and healing state of liver were observed by exploratory laparotomy. The histological changes of regenerate liver tissue were observed by microscopy. RESULTS: Collagen sponge adhered to wound well. Concurrent hemostatic time and bleeding amount in collagen sponge group were superior to those of gelatin sponge (P lt; 0.05). The histological examination showed that collagen sponge was absorbed and degraded rapidly, regenerative hepatocytes could be induced. CONCLUSION: Collagen sponge has fine hemostatic properties and can induce regeneration of hepatocytes effectively. It is worth popularizing for its convenience in clinical application and its properties of rapid degradation and absorption.