Encapsulation of Osteoblast Seeded Microcarriers into Injectable, Photopolymerizable Three-Dimensional Scaffolds Based on d,l-Lactide and ε-Caprolactone

Abstract

UMR-106 seeded microcarriers were encapsulated into in situ, photopolymerizable three-dimensional scaffolds based on d,l-lactide and epsilon-caprolactone. UMR-106 and rat bone marrow cells proliferated and differentiated well on the microcarriers. The microcarriers were completely colonized after 14 days in culture. The viscous polymer paste allowed to mix the UMR-106 seeded microcarriers and gelatin (porosigen) properly. After the photopolymerization process, microcarriers and gelatin were evenly distributed throughout the scaffold. Gelatin was leached out within 7 h, and a porous scaffold was obtained. The microcarriers remained in the scaffold even after 7 days which demonstrates that they were well entrapped in the polymer. Increasing the amount of entrapped microcarriers (20-50%) leads to scaffolds with a reduced cross-linking. Hence, the microcarriers leached out. The encapsulated UMR-106 cells did not show pyknotic nuclei which demonstrates that the photopolymerization and handling the viscous polymer/gelatin/microcarrier paste is not detrimental for the cells.

Evaluation of an Injectable, Photopolymerizable, and Three-Dimensional Scaffold Based on Methacrylate-Endcapped Poly(D,L-Lactide-co-ɛ-Caprolactone) Combined with Autologous Mesenchymal Stem Cells in a Goat Tibial Unicortical Defect Model

“…Declercq et al demonstrated in a previous in vitro study that the encapsulated cells did not show pyknotic nuclei, pointing out that the photopolymerization and handling of the viscous polymer=microcarrier paste were not detrimental for the survival of the cells. 9 The present study confirmed these results in an in vivo setting and demonstrated the implanted cells' ability to proliferate and produce a calcified matrix (osteocalcin positive) inside the polymer as cell proliferation and matrix production were absent in the polymer composite without BMSCs.…”

“…Approximately 400,000 cells were added to each well, depending on the amount of harvested cells. Cells were allowed to adhere under static conditions for 48 h. Afterward, the cell-carrier constructs were carefully transferred to a dynamic culture system (stirring speed 55 rpm) as has been described by Declercq et al 9 The constructs were cultured for an additional 2-3 weeks in osteogenic differentiation medium, with the addition of b-glycerophosphate after 1-week colonization at 378C (5% CO 2 ). Before implantation, cell colonization on the carriers was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt (MTS) analysis (100 mL MTS solution added to 100 mL CultiSpher carriers in 500 mL phenol-red-free medium).…”

“…[7][8][9] Composition of the scaffolds was selected based on the results previously reported. 8,9 No extra porogen was included in the composition of the scaffolds.…”

“…[7][8][9] Composition of the scaffolds was selected based on the results previously reported. 8,9 No extra porogen was included in the composition of the scaffolds. Preceding experiments showed that porosity could be induced by the leaching of the plastizer and as a result of the degradation of the polyester and the CultiSpher microcarrier particles.…”

Plasma Science and Technology - Progress in Physical States and Chemical Reactions

“…The typical pore size ranges typically from 100-1000 µm. More recently, the focus has shifted from thermoplastic biodegradable polymers to hydrogels, as several research groups have now succeeded to mix cells within the polymer feed [36,37]. This generates hybrid scaffolds that are composed of both dead and living species.…”