ABSTRACT
Objective To investigate the characteristics and feasibility of genipin-crosslinked amniotic membrane(AM) as bio-scaffold.Methods Human umbilical cord mesenchymal stem cells (hUCMSCs) were isolated from fresh umbilical cord and cultured by adherent method.The expressions of PE-CD34,PE-CD45,PE-CD90,FITC-105 and FITC-Oct-4,the markers of hUCMSCs,were detected by flow cytometry.Alizarin red and oil red O staining were performed to identify the cells after adipogenesis and osteogenesis induction on the third-generation cells.Human AMs were treated at 37 ℃ and 45 ℃ by 0.5％ and 1％ genipin solution for 24,36 and 48 hours respectively,and the mechanical properties of AM in each group were measured and compared.The hUCMSCs were divided into only hUCMSCs culture group,fresh AM group,crosslinked AM group,gelatin group and crosslinked AM+gelatin group,and the cells were cultured in the corresponding medium.The content of hydroxyproline among the groups was detected with hydroxyproline kit,and proliferation of the cells (absorbance) was assayed by MTT method to evaluate the biological compatibility of crosslinked AM.Results The maximum tensile displacement of the crosslinked-AM by 0.5％ and 1％ genipin was (8.31±0.43)mm and (4.49±0.37)mm respectively,and those after crosslinked with 0.5％ genipin under the 37 ℃ and 45 ℃ for 24 hours was (9.89±1.09)mm and (5.39±0.59)mm,respectively,showing a significant difference between them (t =6.389,P＜0.05).The maximum tensile displacement of the crosslinked-AM was gradually decreased as the lapse of crosslinking time,and an insignificant difference was found among 24,36 and 48 hours after 0.5％ genipin treatment under the 37 ℃ (P＞0.05).The loading force of the crosslinked-AM was significantly higher in the 1％ genipin treated group than that in the 0.5％ genipin treated group (P＜0.05),and the loading force of the AM was significantly increased in 45 ℃,0.5％ genipin,24 hours crosslinked group compared with the 37 ℃,0.5％ genipin,24 hours crosslinked group (t =5.528,P＜0.05).The content of hydroxyproline in the AM was (1.28±0.36),(2.03 ±0.49) and (2.11 ±0.10) mg/g in the 1％ genipin crosslinked AM group,0.5％ genipin crosslinked AM group and fresh AM group,respectively,and the content of hydroxyproline in the AM in the 1％ genipin group was significantly lower than that in the 0.5％ genipin group in the fresh AM group (both at P＜0.05).The proliferative values of the hUCMSCs were significantly lower in the only hUCMSCs culture group,fresh AM group and gelatin group were significantly reduced in comparison with the crosslinked AM group and crosslinked AM+gelatin group (all at P＜0.05).There was no significant difference in the proliferative values of the hUCMSCs between crosslinked AM group and crosslinked AM+gelatin group (P＞0.05).Conclusions Different crosslinked temprature,crosslinking period and concentration of genipin impact the mechanical properties of AM.Crosslinked AM with genipin is feasible as a carrier scaffold of artificial cornea because of less tissue toxicity and better plasticity.
ABSTRACT
Introduction: At the ending of endodontic treatment, is very important that the choice of root canals sealer will be done by biological compatibility criterial, which could promote less inflammation, turning quicker and more effective the healing process. Objective and material and methods: The aim of this study was to evaluate the apical and periapical tissues reactions in dogs teeth, after pulpectomy and root canals cleaning and shaping, which limit was the fisiological barrier of delta apical, and filling with gutta-percha and two calcium hydroxide based endodontics sealers, Sealapex® and Apexit®, by those hystopatological events in observation periods of 7, 21 and 45 days, making a comparison of inflammatory reactions and reparacional evolution that both materials promoted. Past all periods, the dogs were killed and histological cuts of teeth were obtained. Results: Through qualitative-quantitative analysis, Sealapex showed inflammatory level among mild and moderate in all periods, having a great improvement in healing process at 45 days. There was a biggest dispersion of Apexit in periapical tissue, which caused an intense macrophage activity, raising inflammatory level in last period. Conclusion: Regardless of the sealer used, there were observed necrosis in a few of delta apicals ramifications, being mostly in tooth filling by Apexit. In both ways, Sealapex showed best results than Apexit, about increased inflammatory reaction and healing process.
Introdução: No término do tratamento endodôntico é imprescindível que a escolha dos componentes da obturação seja feita com critério em relação à compatibilidade biológica, visando tornar o processo de reparação mais rápido e efetivo. Objetivo e material e métodos: Este estudo teve o propósito de analisar as reações teciduais apicais e periapicais em prémolares de cães, após pulpectomia e preparo químico-cirúrgico, cujo limite foi definido em nível do delta apical, e obturação com cones de gutapercha e dois cimentos contendo hidróxido de cálcio Sealapex® e Apexit®. Foram analisados os eventos histopatológicos em períodos de 7, 21 e 45 dias, a fim de comparar os fenômenos de inflamação e de reparação. Decorridos os períodos de observação, os cães foram sacrificados, e as peças, processadas para análise histológica. Resultados: Empregandose análise quantitativa-qualitativa, verificou-se que o cimento Sealapex® promoveu inflamação entre discreta e moderada em todos os períodos, que evoluiu para reparação aos 45 dias. Houve maior dispersão do cimento Apexit® no tecido periapical, que promoveu intensa atividade macrofágica na área, ampliando os fenômenos de inflamação, mesmo aos 45 dias. Conclusão: Ambos os cimentos provocaram necrose em algumas ramificações do delta apical, ocorrendo porém em maior número nos dentes obturados com Apexit®. Da comparação entre o emprego dos dois cimentos, o Sealapex® foi o que apresentou melhor tolerância tecidual e, por conseqüência, evolução de reparação mais favorável.
ABSTRACT
ETAN is a marine biomaterial which is made of chitosan,a partially deacetylated derivative of chitin ,and prepared by a foaming technique. The effects of absorbing exudate, stopbleeding,promoting wound healing and biological compatibility were observed in this experiment. The results showed ETAN could promote skin wound healing reduce the scab time of the wound surfaces. Skin tissue was healed quickly after ETAN was coated on wound skin surfaces,and it had marked effects of absorbing exudate,and haemostasis. Its effects were superior to that of gelatin sponge. ETAN could be fused with subcutaneous tisssue embeded subcutaneously two weeks later. The fused skin tissue was returned to normal skin tissue nearly after it was embeded four weeks . These experimental results showed ETAN had a better biological compatibility.