腮腺細胞在聚乙烯醇上的行為表現

Abstract

在組織工程中的研究常利用生醫材料作為細胞的載體，因此探討細胞與生醫材料的相互作用是相當重要的課題，由過去研究已知生醫材料的親疏水性對於細胞的生長有巨大的影響，因此在生醫材料的選擇上，親疏水性是一個相當重要的考慮因素，本研究的目的在於探討腮腺細胞在高親水性材料聚乙烯醇和一般培養皿上的生長情形，利用免疫螢光染色反應鑑定細胞的特有功能性表現，並使用光學顯微鏡及掃描式電子顯微鏡觀察細胞型態，加以比較。 研究結果發現當腮腺細胞在聚乙烯醇上培養，細胞並不會貼附在基材表面，而是聚集成團並懸浮在培養液中，掃描式電子顯微鏡觀察發現培養在聚乙烯醇上的腮腺細胞，在剛形成球團的初期，細胞與細胞間仍保有一些距離，可以輕易分辨出單顆細胞，長時間培養在聚乙烯醇後，細胞與細胞被細胞間基質所覆蓋，造成細胞融合現象，使球團表面無法分辨單顆細胞。當腮腺細胞在聚乙烯醇上聚集成球團時，免疫螢光染色可以發現具有腮線細胞特有的功能表現澱粉酶之存在，細胞在接受乙醯膽鹼的刺激時，聚集成團的細胞比在一般培養皿上貼附的細胞，更容易接受刺激而且會產生較大的酵素活性反應。 實驗結果亦發現，若將在聚乙烯醇材料上聚集成團的細胞再種回一般培養皿上時，細胞會從球團中慢慢爬出，繼續生長並表現澱粉酶功能，因此可以確定利用聚乙烯醇的高親水特性使細胞經碰撞，自我組裝成團狀，團狀的細胞較類似生物體內的立體狀態，故可表現較佳的細胞功能性，根據以上結果顯示聚乙烯醇可作為保存細胞使細胞較近似生物體內的立體結構並提高細胞功能的生醫材料，可作為唾液腺再生的應用。

Biomaterials are usually applied for growing of cells in tissue engineering. It is very important to understand the interactions of cells with biomaterials. Upon this, hydrophilicity of biomaterials is one of the most important factors in the effects of cell-surface interactions. The purpose of this reserch was to investigate the behaviors of parotid acinar cells on polyvinyl alcohol which is with high hydrophilicity. Acinar cells were cultured on PVA, and tissue culture plates (TCPS) were used as control group. Functional expression of α-amylase in acinar cells was identified with immuno-fluorescent staining technique. Cell morphology on PVA and TCPS were investigated with light microscopy and scanning electron microscopy (SEM). Our results demonstrated that in contrast to of attachment of cells on TCPS, cells were suspended and aggregated as spheres on PVA. In the initial stage of cell sphere formation, single cell interface could be identified with SEM. However, after cultured on PVA for a long period, the cell-cell interface was covered with extracellular matrix and cells were hard to identify single cell interface. Immno-fluorescent staining of α-amylase revealed the functional activities of aggregated acinar cells on PVA. Additionally, when receiving the acetylcholine stimulation, these cell aggregates were with higher functional activities compared to those on TCPS. When aggregated cells on PVA were transferred to TCPS, migration from the aggregates and reattachment on TCPS were evident and cells were also with α-amylase expression. Our results demonstrated that acinar cells on high hydrophilic biomaterial PVA could be self-assembled as three-dimensional spheres which are more resemble the in vivo state and with better function. We proposed that PVA might be applied for preserving the acinar cells in three-dimensional cell sphere which are more similar to the biological condition in vivo with better function for salivary gland regeneration.