Scaffolds cell culturing

Yang SH et al (2005) Gelatin/chondroitin-6-sulfate copolymer scaffold for culturing human nucleus pulposus cells in vitro with production of extracellular matrix. J Biomed Mater Res B Appl Biomater 74(l) 488 f94... 

Figure 27. Human osteoblast-like MG 63 cells in cultures on porous (A) or fibrous (B) poly(L-lactide-co-glycolide) scaffolds. A A summarizing picture of horizontal optical sections. The depth of cell ingrowth into the pores (average pore diameter of 400-600 mm) is indicated by spectral colors (blue 0-60 mm, green 80-160 mm, yellow 180-220 mm, orange 240-300 mm, red 320-400 mm, violet 420-480 mm). Day 14 after seeding, cells stained with propidium iodide. B cells grown for 4 days in static culture followed by 2 days in dynamic perfusion cell culture system. Cell membrane stained with Texas Red C2-maleimide and the nuclei counterstained with Hoechst 33342. Leica TCS SP2 confocal microscope, objective 5x (A) or lOx (B) [37].

Although certain simple functions of the liver, such as the removal of some toxins, can be performed by using dialysis and adsorption with activated charcoal, it is clear that such a simple artificial approach cannot perform the complex functions of the liver, and that any practical liver support system must use living hepatocytes. It should be mentioned at this point that hepatocytes have an anchorage-dependent nature that is, they require a form of anchor (i.e., a solid surface or scaffold) on which to grow. Thus, the use of single-cell suspensions is not appropriate for liver cell culture, and fiver cells attached to solid surfaces are normally used. Encapsulated fiver cells and spheroids (i.e., spherical aggregates of fiver cells) may also be used for this purpose. 

One design requirement is to provide a physical scaffold that permits near-normal proliferation of cells. Proliferation is encouraged by scaffold with an open and curvilinear structure — a more or less natural conformation. For example, hepatic cells cultured on a flat plate do not function. The cell survival signals are functional as evidenced by our ability to keep cells alive, but their metabolic functions are destroyed when they are forced into a flat conformation. By inference, therefore, a concave structure is thought to be appropriate. As cells migrate to coat a surface, it is equally important to provide a scaffold that has as open an architecture as possible so as not to inhibit spreading. 

Folch, A., Mezzour, S., During, M., Hurtado, O., Toner, M., Muller, R., Stacks of microfabricated structures as scaffolds for cell culture and tissue engineering. Biomed. Microdevices 2000, 2(3), 207-214. 

Petronis S, Eckert KL, Gold J, Wintermantel E. Microstructuring ceramic scaffolds for hepatocyte cell culture. J Mater Sci Mater Med 2001 12 523-8. 

As summarized in Fig. 1, the components that must be customized based on the application include cell source, scaffold parameters, and cell culture procedures. 

In summary, there are many stem cell types that have the potential for cardiac repair, but more sophisticated cell culture and TE approaches need to be developed. In addition, the main obstacle influencing cell therapeutic efflcacy is the high death rate of donor stem cells after transplantation. Fabrication of biomaterial scaffolds with suitable nanostructure could be a feasible strategy for optimizing stem cell therapy for cardiac regeneration. 

Several cell culture studies demonstrated that scaffolds made via self-assembling peptides provide permissive substrates for cell attachment and growth as well as support for extensive neurite outgrowth and synapse formation [104-106],... 

Although aligned polymer nanofibers have some similarities to namral ECM, it is vital to tissue regeneration that resident cells produce their own natural matrix to compliment or replace the engineered scaffold. Substrate microstnicmre has pronounced effects on both the amount of ECM produced by resident cells and the architecture of that matrix. Increased ECM production has been observed in cells cultured on nanofibrous substrates compared to those on flat substrates and large (15 pm) microfibers [106, 135], The specific fiber diameter of nanofibrous substrates may also affect the ECM production of attached ceUs [129],... 

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