Hao Ying, Zerdoum Aidan B, Stuffer Alexander J, Rajasekaran Ayyappan K, Jia Xinqiao
Department of Materials Science and Engineering, University of Delaware , Newark, Delaware 19716, United States.
Department of Biomedical Engineering, University of Delaware , Newark, Delaware 19716, United States.
Biomacromolecules. 2016 Nov 14;17(11):3750-3760. doi: 10.1021/acs.biomac.6b01266. Epub 2016 Oct 20.
Toward the goal of establishing physiologically relevant in vitro tumor models, we synthesized and characterized a biomimetic hydrogel using thiolated hyaluronic acid (HA-SH) and an acrylated copolymer carrying multiple copies of cell adhesive peptide (PolyRGD-AC). PolyRGD-AC was derived from a random copolymer of tert-butyl methacrylate (tBMA) and oligomeric (ethylene glycol) methacrylate (OEGMA), synthesized via atom transfer radical polymerization (ATRP). Acid hydrolysis of tert-butyl moieties revealed the carboxylates, through which acrylate groups were installed. Partial modification of the acrylate groups with a cysteine-containing RGD peptide generated PolyRGD-AC. When PolyRGD-AC was mixed with HA-SH under physiological conditions, a macroscopic hydrogel with an average elastic modulus of 630 Pa was produced. LNCaP prostate cancer cells encapsulated in HA-PolyRGD gels as dispersed single cells formed multicellular tumoroids by day 4 and reached an average diameter of ∼95 μm by day 28. Cells in these structures were viable, formed cell-cell contacts through E-cadherin (E-CAD), and displayed cortical organization of F-actin. Compared with the control gels prepared using PolyRDG, multivalent presentation of the RGD signal in the HA matrix increased cellular metabolism, promoted the development of larger tumoroids, and enhanced the expression of E-CAD and integrins. Overall, hydrogels with multivalently immobilized RGD are a promising 3D culture platform for dissecting principles of tumorigenesis and for screening anticancer drugs.
为了建立与生理相关的体外肿瘤模型，我们使用硫醇化透明质酸（HA-SH）和携带多个细胞黏附肽拷贝的丙烯酸化共聚物（PolyRGD-AC）合成并表征了一种仿生水凝胶。PolyRGD-AC由甲基丙烯酸叔丁酯（tBMA）和甲基丙烯酸寡聚（乙二醇）酯（OEGMA）的无规共聚物衍生而来，通过原子转移自由基聚合（ATRP）合成。叔丁基部分的酸水解揭示了羧酸盐，通过这些羧酸盐安装了丙烯酸酯基团。用含半胱氨酸的RGD肽对丙烯酸酯基团进行部分修饰生成了PolyRGD-AC。当在生理条件下将PolyRGD-AC与HA-SH混合时，产生了平均弹性模量为630 Pa的宏观水凝胶。封装在HA-PolyRGD凝胶中的LNCaP前列腺癌细胞以分散的单细胞形式在第4天形成多细胞肿瘤样结构，到第28天平均直径达到约95μm。这些结构中的细胞是有活力的，通过E-钙黏蛋白（E-CAD）形成细胞间接触，并显示出F-肌动蛋白的皮质组织。与使用PolyRDG制备的对照凝胶相比，HA基质中RGD信号的多价呈现增加了细胞代谢，促进了更大肿瘤样结构的发育，并增强了E-CAD和整合素的表达。总体而言，具有多价固定化RGD的水凝胶是用于剖析肿瘤发生原理和筛选抗癌药物的有前途的3D培养平台。
