Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 3, D-14195 Berlin, Germany.
J Am Chem Soc. 2012 Mar 14;134(10):4983-9. doi: 10.1021/ja300460p. Epub 2012 Mar 1.
Micrometer-sized hydrogel particles that contain living cells can be fabricated with exquisite control through the use of droplet-based microfluidics and bioinert polymers such as polyethyleneglycol (PEG) and hyperbranched polyglycerol (hPG). However, in existing techniques, the microgel gelation is often achieved through harmful reactions with free radicals. This is detrimental for the viability of the encapsulated cells. To overcome this limitation, we present a technique that combines droplet microfluidic templating with bio-orthogonal thiol-ene click reactions to fabricate monodisperse, cell-laden microgel particles. The gelation of these microgels is achieved via the nucleophilic Michael addition of dithiolated PEG macro-cross-linkers to acrylated hPG building blocks and does not require any initiator. We systematically vary the microgel properties through the use of PEG linkers with different molecular weights along with different concentrations of macromonomers to investigate the influence of these parameters on the viability and proliferation of encapsulated yeast cells. We also demonstrate the encapsulation of mammalian cells including fibroblasts and lymphoblasts.
可以使用基于液滴的微流控技术和生物惰性聚合物（如聚乙二醇（PEG）和超支化聚甘油（hPG）），以精细控制的方式制造含有活细胞的微米级水凝胶颗粒。然而，在现有的技术中，微凝胶的凝胶化通常是通过与自由基的有害反应来实现的。这对被包裹细胞的存活率有害。为了克服这一限制，我们提出了一种结合液滴微流控模板和生物正交的巯基-烯点击反应的技术，用于制造单分散、载细胞的微凝胶颗粒。这些微凝胶的凝胶化是通过二硫代 PEG 大分子交联剂对丙烯酰化 hPG 结构单元的亲核迈克尔加成反应来实现的，不需要任何引发剂。我们通过使用具有不同分子量的 PEG 连接子以及不同浓度的大分子单体来系统地改变微凝胶的性质，研究这些参数对被包裹酵母细胞的存活率和增殖的影响。我们还展示了包括成纤维细胞和淋巴母细胞在内的哺乳动物细胞的封装。
