Preparation Of Smart Hydrogel Microsphere And Its Application In 3D Culture Of Ovarian Cancer Cells In Vitro

Cells culture in vitro has always been an important part in the field of biological tissue engineering. Since the cellular microenvironments in vivo, which consist of chemical, physical and biological factors, are so sophisticated, the integration of these factors is possible to be an effective method to replicate the cellular microenvironment, which can make cell behaviors in vitro similar to those in vivo. Cells three-dimensional culture (cells 3D culture) refers to mimicking the fibrous extracellular matrix (ECM) in vivo, including of chemical, physical and biological factors, and culturing cells on three dimensional matrix scaffolds. Compared to cells two-dimensional culture (cells 2D culture), cells 3D culture in vitro is closer to the cellular microenvironment, and it is more widely used in tissue engineering.With the development of tissue engineering, hydrogel has been widely used in cells 3D culture since its good biological compatibility, exact composition and structure, repeatable production, etc. Hydrogel is a kind of polymer that has 3D net structure and can swelling but do not dissolve. Its special structure and high water content is similar to the property of ECM. Supramolecular hydrogel based on cyclodextrin (CD) is a special kind of hydrogel. Besides the basic properties of normal hydrogel, such as good biocompatibility, high water content, and drug loading etc., it also has the intelligence according to specific self-assembly and molecular recognition, such as photo-responsive, thermos-responsive, pH-responsive, etc.In this study, we prepared intelligent hydrogel microspheres on which RGD (Arginine-Glycine-Aspartic acid) is introduced based on the host-guest interaction of P-cyclodextrin (P-CD) and azobenzene (Azo). We experimentally explored its application in ovarian cancer SKOV3 cells culture. After visible light irradiation, SKOV3 cells show good adhesion on the microspheres since the existence of RGD, which is good for cells culture; while once the UV irradiation, SKOV3 cells separate from microspheres since the inexistence of RGD, which is good for cells capture. The studies mainly concerns on the followings:1. The preparation and characterization of PEG cross-linked P-CD grafted poly (methyl vinyl ether-alt-maleic acid) (P(MVE-alt-MA)-g-β-CD) microspheres. P(MVE-alt-MA)-g-β-CD was prepared through the esterification reaction of poly(methyl vinyl ether-alt-maleic anhydride) P(MVE-alt-MAH) and β-CD, and PEG cross-linked P(MVE-alt-MA)-g-β-CD microspheres are prepared by inverse suspension polymerization. The morphology of microspheres was observed by optical microscope and scanning electron microscope (SEM). We found that the microspheres had a smooth surface and a relative uniform particle size distribution.2. RGD is firstly connected to Azo, then RGD is assembled on the microspheres through the host-guest interaction of β-CD and Azo, and finally the photo-responsive microspheres are achieved. β-CD has a hydrophilic outer surface and a hydrophobic inner cavity and their internal cavities could form inclusion complexes with hydrophobic guest molecules. Azo as a guest can enter P-CD’s internal cavity under visible light irradiation and separate from the internal cavity under UV irradiation.3. Culturing SKOV3 cells on the smart microspheres. We analyze the cells viability and proliferation on different microspheres with different light condition. It shows that the SKOV3 cells adhesion on microspheres before UV irradiation is better than that after UV irradiation.