3D polylactide-based scaffolds for studying human hepatocarcinoma processesin vitro

Abstract

We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-based blends, on the simultaneous bulk/surface modifications and pore architectures in the scaffolds, and assessed the effects on human hepatocarcinoma viability and cell adhesion. The influence of PEG molecular weight on the scaffold morphology and cell viability and adhesion were also investigated. Morphological studies indicated that it was possible to obtain scaffolds with well-interconnected pores of assorted sizes. The analysis confirmed that SK-Hep1 cells adhered well to the polymeric support and emitted surface protrusions necessary to grow and differentiate three-dimensional systems. PEGs with higher molecular weight showed the best results in terms of cell adhesion and viability.

Melt Processed PCL/PEG Scaffold With Discrete Pore Size Gradient for Selective Cellular Infiltration

“…The presence of another water-soluble organic phase in the mixture, PEG, had the role to increase the degree of interconnection between the pores by allowing a complete leaching of mineral filler as shown in a previous works. [39][40][41] The porosity calculated by Equation (2), in fact, is very close to the theoretical one for all the scaffold types, which makes reasonable to conclude that all the filled porogen agents were extracted from the devices. This hypothesis is confirmed by the connectivity, higher than 99% for all the materials, as calculated from Equation (3).…”

“…In fact, micropores network, characterized by pores ranging from 1 to 5 mm are reasonably due to PEG solvation, can be observed in the pores wall. [39,40] Finally, M 10 materials, (Figure 2c), present the highest density of pores per unit of volume. This structure is highly interconnected and its pores have an average pores size of 20 mm with very thin walls (thickness even below than 1 mm).…”

“…[39][40][41] In brief, PCL, PEG, and NaCl, with composition of respectively 20/5/75 wt%, were fed to a batch mixer (Brabender PLE-330 T ¼ 100 8C, n ¼ 60 rpm) and processed until a constant value of torque was achieved, usually after about 10 min. The PEG:NaCl ratio was chosen based on the promising results described in our previous work.…”

“…The PEG:NaCl ratio was chosen based on the promising results described in our previous work. [39] The blend was then fed out and rapidly cooled with liquid nitrogen. In particular, three blends were developed by changing only the NaCl granulometry: M 100 with NaCl grains sieved in the fraction 90-110 mm, M 50 ranging from 45 to 65 mm, and M 10 with NaCl particles <45 mm, as summarized in Table 1.…”

“…[38] Poly(ethylene glycol) (PEG) is the moiety most commonly used to develop tunable surface properties in terms of protein adsorption and cell adhesion. [39] In this work, an eco-friendly technology based on melt mixing and salt water leaching to prepare three-layer (TL) porous scaffolds is presented. The combination of melt mixing and salt leaching in water, differently from many others scaffold production technologies can be considered eco-friendly because it does not need the use of organic solvent, potentially dangerous for environment and for living cells and tissues.…”