Multifunctional poly(2-oxazoline)-based macromonomers for the preparation of ECM-analogous multi-compartment cell support structures and biogels for tumor tissue engineering (TTE)

尽管肿瘤医学取得了巨大的进步，但为了阐明潜在的复杂分子和细胞过程并将其转化为有效的治疗方法，仍然需要进行大量的研究。优化的细胞培养模型可以对此做出决定性的贡献。除了经典的体细胞突变理论外，肿瘤微环境（tumor microenvironment， TME），即肿瘤相关的细胞外基质（extracellular matrix， ECM）也日益成为当前研究的热点。在组织工程（TE）的帮助下，可以建立肿瘤基质的ecm样模型，该模型可以在体外绘制肿瘤发生和肿瘤进展的各个阶段。在本项目中，该方法将借助纳米3d光刻技术（双光子聚合/ 2PP）和一类合适的功能聚合物，多功能聚（恶唑啉）（POx），建立肿瘤基质的ecm类似模型。这些将可用于诊断性TE（疾病建模）应用领域的研究，也可用于治疗性TE（再生）领域的研究，并将进行初步测试。从长远来看，这种结构也可以适用于微流体器官模型（芯片上的器官）。在该项目中，将合成两种不同类型的POx: i)具有可聚合端基的POx，用于使用2PP生产机械稳定的（Schwarz P-）支架结构；ii)具有交联化学功能的POx，用于生成具有定义粘度的“生物凝胶”，用于在支架结构中嵌入类似ecm的细胞。这两种元件，支架和生物凝胶，都将配备类似于天然ECM的生物功能分子。因此，它旨在将具有细胞粘附作用的肽序列（例如RGD肽）共价固定在支架和生物凝胶上，以及在痘生物凝胶中具有蛋白水解作用的肽序列（例如mmp敏感肽）。药物传递功能可以选择性地使用与POx和肝素的共聚物方法来实现，其中整个体相作为药物储存库。或者，基于pox的细胞载体结构也可以使用聚电解质（例如聚l -赖氨酸/肝素）在一层一层的过程中功能化，这样可以获得额外的药物传递功能。纳米级结构工艺（2PP）和多功能聚合物平台的理想组合导致了质量上的新设计，避免了以前生成人工ecm方法的显着缺点。

Despite immense progress in tumor medicine, there is still a significant need for research in order to elucidate the underlying complex molecular and cellular processes and to convert them into efficient therapeutic approaches. Optimized cell culture models can make a decisive contribution to this. In addition to the classic somatic mutation theory, the tumor microenvironment (TME), or in other words, the tumor-related deregulated extracellular matrix (ECM) is increasingly becoming the focus of current research. With the help of tissue engineering (TE), ECM-like models of the tumor matrix can be established that can map the various stages of tumorigenesis and tumor progression in vitro.In the present project, the approach is to be pursued with the help of nano-3D-lithography (two-photon polymerization / 2PP) and a suitable class of functional polymers, the multifunctional poly (oxazolines) (POx), ECM-analogous models of the tumor matrix are built up. These will be available for research in the application area of diagnostic TE (disease modeling) but also in the area of therapeutic TE (regeneration) and will be subjected to initial tests. In the long term, such structures can also be adapted for microfluidic organ models (organ-on-a-chip).In the project, two different types of POx will be synthesized: i) POx with polymerizable end groups for the production of mechanically stable (Schwarz P-) scaffold structures using 2PP and ii) POx with cross-linkable chemical functionalities to generate "biogels" with defined viscosity for the ECM-like embedding of cells within the scaffold structures. Both elements, the scaffolds and biogels, will be equipped with biofunctional molecules analogous to a natural ECM. It is therefore intended to covalently immobilize peptide sequences with a cell adhesive effect (e.g. RGD peptides) on both scaffolds and biogels, as well as peptides with a proteolytic effect (e.g. MMP-sensitive peptides) in the POx biogels. A drug delivery function can optionally be implemented using a copolymer approach with POx and heparin, in which the entire bulk phase functions as a drug reservoir. Alternatively, the POx-based cell carrier structures can also be functionalized in a layer-by-layer process using polyelectrolytes (e.g. poly-L-lysine / heparin) in such a way that an additional drug delivery function is available. The desired combination of a nanoscale structuring process (2PP) and the multifunctional polymer platform results in a qualitatively new design, which avoids significant disadvantages of previous approaches to the generation of artificial ECMs.