ABSTRACT
Background Excessive elongation of axis and expansion of sclera is one of the hot topics in the study of the pathogenesis of high myopia.To establish a human scleral fibroblasts (HSFs)-collagen matrix culture model is helpful for understanding the reciprocal and adaptive interactions between HSFs and the collagen matrix in tissue.Objective The aim of this study was to establish a HSFs-seeded collagen three-dimension culture system that may mimic the sclera remolding in myopia.Methods HSFs were isolated and cultured from donor eyes by explant culture and purified by passages culture in vitro.The expressions of vimentin and keratin in the cells were detected by immunofluorescence technique to identify the cells.Rat tail tendon was obtained from 8-week-old SPF SD rats to prepare the collagen matrix.The mixed solution of 400 μl collagen matrix and 1 100 μl PBS,200 μ1 nutrient medium,50 μ1 NaOH and HSF suspension were mixed to prepare the collagen gel three-demension culture system.The growth and morphology of the cells in the culture system were observed under the inverted phase contrast microscope,and IPP-5 software was used to measure the contraction area of collagen gel,and the mechanical creep properties of the HSFs-seeded collagen matrix were measured by a biomechanics test instrument.Results HSFs emigrated from tissue 7 days after culture and passage could be performed 14 days after culture.The expression of keratin was absent in HSFs,while vimentin was positively expressed.The free-cell collagen gel was clear and unchanged in the experimental duration.However,the cells were obviously increased on the three-demension culture system and showed a tissue-like structure of net-like arrangement on dozens of layers.In 7-14 days after culture,the collagen gel area in a three-demension collagen matrix revealed a decrease of 90％.Duotriode-like and fusiform cells were seen 24 hours after culture.The biomechanical creep curve of HSFs-seeded collagen matrix consisted of the nonlinear section (0-100 seconds) and linear section (100-600 seconds),and the former appeared to be an elastic change of the gel under the temporal stress,and the latter was the creeping of the gel with the time.Conclusions Rat tail collagen appears to have a good biocompatibility to HSFs.HSFs-seeded collagen matrix can retain the mechanical creep properties,and it may be a good tool for the study on the relationship between HSFs and extracellular matrix or intercellular biological behaviour for scleral remodeling.
ABSTRACT
Sclera plays an very important role in maintenance of eyeball structure and its functions. The biological and biomechanical properties of sclera is determined by the extra cellular matrix metabolism, the cytokine expression and its own biomechanical properties of scleral fibroblasts. Lots of biological and biomechanical changes in sclera and scleral fibroblasts are the concomitants in the process of myopic development and therapy. The biomechanical studies on sclera and scleral fibroblasts by Mechanics Biology coupling will enable to reveal the physiological function, pathological change and therapeutic mechanism of ocular organ and in this review, such biomechanical studies about sclera and scleral fibroblasts were summarized and discussed.
ABSTRACT
Objective To evaluate the biomechanical properties of fibroblasts for rabbit experimental myopia after Posterior Scleral Reinforcement (PSR) treatment, and discuss the mechanism of PSR in myopia treatment as viewed from biomechanics. Method 45 rabbits of three week old were randomly monocular treated by eyelid suture to prepare experimental myopia eye. After 60 days, the experimental myopia eyes were divided into two groups randomly. Group A was treated by PSR. Group B was treated by similar operation without placing reinforce strap. After three months and six month, the fibroblasts from each group were isolated and cultured in vitro respectively. The cultured cells were then determined to be fibroblasts by using immunocyte chemistry method. Micropipette aspiration technique was used to investigate the viscoelastic properties of the fibroblasts from each group with mechanical model of semi infinite somatic cells. ResultsThree months after operation, the viscoelastic properties of the scleral fibroblasts in Group A and Group B exhibit no significant difference (P>0.05) three months and six months as well (P>0.05) after operation with the equilibrium modulus, E∞, and apparent viscosity, μ of the scleral fibroblasts in Group A (E = (361.2± 121.1)Pa、μ=(2928.2±669.4)Pa·s) compared with that in Group B (E =(347.6± 82.1)Pa、μ=(2820.6± 593.5)Pa·s). Neither in Group A nor Group B, the E∞ and μ at different stages after operation have significant difference (P>0.05). The E∞ and μ in transition zone tissues at different stages after operation have no significant difference(P>0.05) either. Conclusions The enhancement of PSR is caused by transition zone tissues and the strip itself.