The response of gingiva monolayer, spheroid, and ex vivo tissue cultures to collagen membranes and bone substitute

Abstract

Collagen membranes and bone substitute are popular biomaterials in guided tissue regeneration for treatment of traumatized or diseased periodontal tissue. Development of these biomaterials starts in monolayer cell culture, failing to reflect in vivo tissue organization. Spheroid cultures potentially mimic in vivo tissues in structure and functionality. This study aims to compare gingiva cell (GC) monolayers and spheroids to ex vivo gingiva. Human GC monolayers, spheroids and gingiva ex vivo tissues were cultured on plastic surfaces, collagen membranes or bone substitute. Hematoxylin–eosin (HE) staining, immunohistochemistry for KI67 and caspase 3 (CASP3), resazurin‐based toxicity assays, quantitative polymerase chain reaction for collagen I (COL1A1), vascular endothelial growth factor (VEGF), angiogenin (ANG), interleukin (IL)6 and IL8 and ELISA for COL1A1, VEGF, ANG, IL6 and IL8 were performed in all cultures. Morphology was different in all culture set‐ups. Staining of KI67 was positive in monolayers and staining of CASP3 was positive in spheroids. All culture set‐ups were viable. COL1A1 production was modulated in monolayers and ex vivo tissues at mRNA levels, VEGF in monolayers and ex vivo tissues at mRNA levels and in spheroids at protein levels, ANG in spheroids at mRNA levels and in monolayers and spheroids at protein levels, IL6 in monolayers and spheroids at mRNA levels and in spheroids and ex vivo tissues at protein levels and IL8 in monolayers and ex vivo tissues at mRNA levels. Modulations were surface‐dependent. In conclusion, each culture model is structurally and functionally different. Neither GC monolayers nor spheroids mimicked gingiva ex vivo tissue in all measured aspects.

Highly Mimetic Ex Vivo Lung‐Cancer Spheroid‐Based Physiological Model for Clinical Precision Therapeutics

“…The level of Ki‐67 in the spheroid group was lower than that in the 2D culture, validating that the 2D culture exhibited unrestricted proliferation when compared with that in the spheroid group, which was mainly observed at the periphery of the spheroid. [ 32 ] The high levels of HIF‐1 α and EGFR in the spheroid group indicated that hypoxic conditions could be replicated using the proposed spheroid model, thereby leading to an increase in the EGFR response to hypoxic conditions. [ 33 ] In addition, the increments in E‐cadherin and β ‐catenin levels in the western blot results also indicated the enhanced cell–cell junction formation in this 3D spheroid model.…”

Light‐controlled scaffold‐ and serum‐free hard palatal‐derived mesenchymal stem cell aggregates for bone regeneration

“…Second, great osteogenic capacity of cell aggregates was confirmed by a number of researches 72–74 and our in vivo studies. Cytochemical analysis, gene expression quantification, and protein expression quantification showed that MSC aggregates were associated with increased ALP activity and higher levels of expression of osteogenic markers, including osteocalcin, ALP, Runx2, collagen I, and BMPs 74–76 . Related signaling pathways might include the Wnt/β‐catenin and BMP‐Smad pathways, as indicated by more significant upregulation of the p‐Smad1/5, p‐p38, phospho‐extracellular signal‐regulated kinase (p‐ERK), β‐catenin, and secreted frizzled‐related protein 3 (SFRP3) that was detected in the cell aggregates 77,78 …”

Flow cytometric quantification of apoptotic and proliferating cells applying an improved method for dissociation of spheroids

“…Contrary to reports on the size development of tumor spheroids (Mamnoon et al, 2020), the size of spheroids of primary cells again decreased over time probably caused by a decrease in the size of single cells within the spheroid (Grässer et al, 2018; Takezawa et al, 1993). The loss of contact inhibition, which is characteristic of tumor cells, leads to high cell proliferation in tumor spheroids whereas only a low cellular proliferation is reported for primary cells organized as spheroids (Janjic et al, 2020).…”