3

Methods

All the procedures of sample preparation and bioreactor culture

must follow Good Laboratory Practice (GLP) within the biosafety

rules for the type of cell to be used, according to the application of

interest (usually SL-1 or SL-2 cell types). The method described

can be applied to several types of scaffold materials; therefore,

according to their mechanical properties, the parameters of force

and flow must be previously tested.

3.1

Sample

Preparation

1. Sterilize the scaffolds prior to seed them with cells. The scaffold

sterilization method must respect its physicochemical proper-

ties, so the most common ones are autoclaving or UV-C bath

(see Note 5).

2. Seed the scaffolds with the desired cell type according to the

application of interest.

3. Keep the scaffolds under preculture in static conditions during

4 days, following standard procedures [21] (see Note 6).

Fig. 3 Bioreactor system (ElectroForce^® BioDynamic 5210^®, Bose/TA Instruments). Samples are placed

between the upper and lower columns (a) and the system is connected by a peristaltic pump. Regardless of

flow direction, the medium is oriented to be directly pumped throughout the scaffolds. Cell loads force sensors

are directly connected to each chamber (b). (Adapted with permission from Springer: Biotechnology Letters,

Ref. 6, Enhancement of cartilage extracellular matrix synthesis in poly(PCL-TMC)urethane scaffolds: a study of

oriented dynamic flow in bioreactor, Pedrini et al., 2020)

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