A 3D in vitro co-culture model for evaluating biomaterial-mediated modulation of foreign-body responses

• DOI: 10.1007/s42242-022-00198-z
• Publication Date: 2022-05-18T15:06:58Z
• Authors: Betul Cakmak; Pelin Saglam-Metiner; Goze Beceren; Yu S. Zhang; Ozlem Yesil-Celiktas
• Keywords: 0303 health sciences; 4. Education; Cell-Culture; Activation; Hydrogels; Environment; Biomaterial; 3. Good health; Phenotypes; 03 medical and health sciences; Differentiation; Macrophage polarization; Biocompatibility; Genotoxicity; Immune response; Macrophage Polarization; Repair; Hyaluronic-Acid

This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under the grant number 219M057. PSM acknowledges TUBITAK 2211-A National Graduate Scholarship Program and BC acknowledges TUBITAK 2210-C National Priority Areas Graduate Scholarship Program. YSZ acknowledges support by the Brigham Research Institute.<br/>The immune response after implantation of a biomaterial may shorten the functional life of the implant, depending on the degree of the response. In this study, we used a polyacrylamide-alginate (PAAm-Alg) hydrogel, which has been previously characterized as a biocompatible material and shown to enhance regeneration of cartilage in vivo, along with a graphite-enhanced hydrogel (PAAm-Alg-G) as a non-biocompatible counterpart, to evaluate macrophage attachment and polarization to pro- or anti-inflammatory phenotypes. The performance of each biomaterial in the presence of fibroblasts and chondrocytes was validated by an in vitro model which demonstrated modulation of the foreign-body response. A blend of 5% gelatin methacryloyl and 0.1% methacrylated hyaluronic acid was optimized to mimic the extracellular matrix (ECM) and support cell viability, proliferation, migration, and functionality at an initial concentration of 3.25 x 10(5) cells/mL. The PAAm-Alg-G hydrogel localized in the simulated ECM showed cytotoxic and genotoxic effects for both fibroblasts and chondrocytes, while exhibiting a proliferative effect on macrophages with elevated immune response. The M1/M2 ratio was 0.73 for PAAm-Alg hydrogel but 2.64 for PAAm-Alg-G, leading to significant M1 dominance (p 0.0001), as expected, on day 13. Moreover, loading PAAm-Alg hydrogel with transforming growth factor beta-3 (TGF-beta 3) resulted in a slightly more balanced M1/M2 ratio of 0.87 (p > 0.05). The interleukin-6 (IL-6) concentration secreted in the presence of PAAm-Alg hydrogel (4.58 pg/mL) significantly decreased (p 0.0001) on day 13, while the increase (p 0.0001) in interleukin-10 (IL-10) concentration (120.73 pg/mL) confirmed the switch from a pro-inflammatory to an anti-inflammatory response. Predicting immune responses by developing a simplistic yet powerful three-dimensional in vitro model provides advantages in preparing for clinical use of biomaterials. [GRAPHICS] .<br/>Scientific and Technological Research Council of Turkey (TUBITAK) [219M057]; TUBITAK 2211-A National Graduate Scholarship Program; TUBITAK 2210-C National Priority Areas Graduate Scholarship Program; Brigham Research Institute<br/>