Monocyte Infiltration and Differentiation in 3D Multicellular Spheroid Cancer Models

Tumor-associated macrophages often correlate with tumor progression, and therapies targeting immune cells in tumors have emerged as promising treatments. To select effective therapies, we established an in vitro 3D multicellular spheroid model including cancer cells, fibroblasts, and monocytes. We analyzed monocyte infiltration and differentiation in spheroids generated from fibroblasts and either of the cancer cell lines MCF-7, HT-29, PANC-1, or MIA PaCa-2. Monocytes rapidly infiltrated spheroids and differentiated into mature macrophages with diverse phenotypes in a cancer cell line-dependent manner. MIA PaCa-2 spheroids polarized infiltrating monocytes to M2-like macrophages with high CD206 and CD14 expression, whereas monocytes polarized by MCF-7 spheroids displayed an M1-like phenotype. Monocytes in HT-29 and PANC-1 primarily obtained an M2-like phenotype but also showed upregulation of M1 markers. Analysis of the secretion of 43 soluble factors demonstrated that the cytokine profile between spheroid cultures differed considerably depending on the cancer cell line. Secretion of most of the cytokines increased upon the addition of monocytes resulting in a more inflammatory and pro-tumorigenic environment. These multicellular spheroids can be used to recapitulate the tumor microenvironment and the phenotype of tumor-associated macrophages in vitro and provide more realistic 3D cancer models allowing the in vitro screening of immunotherapeutic compounds.

Hydrogel with supramolecular surface functionalization for cancer cell capture and multicellular spheroid growth and release

A hydrogel scaffold with non-fouling but specific cancer cell adhesive surface was fabricated through surface modification using β-cyclodextrin-based host-guest chemistry. Interestingly, the hydrogel surface not only selectively captured specific cancer...

Recent Advances in Three-Dimensional Multicellular Spheroid Formation for Biomedical Research

Multicellular spheroids (MCSs) from three dimensional culture, which is a complex architectural structure with dynamic cell to cell and cell to matrix interactions, mimic real tissues regarding structural and functional properties. MCSs have emerged as an effective tool for filling up the gap between the in vitro and in vivo experimental model and can replace the in vivo model. The viability and functional performance can be enhanced when cells are grown as multicellular spheroid (MCS). In this review paper, we discussed the basic mechanism of MCS formation, their biomedical applications, and recent advances in MCS culture and tissue engineering.

Far from equilibrium dynamics of tracer particles embedded in a growing multicellular spheroid

Local stresses on the cancer cells (CCs) have been measured by embedding inert tracer particles (TPs) in a growing multicellular spheroid. The utility of the experiments requires that the TPs do not alter the CC microenvironment. We show, using theory and extensive simulations, that proliferation and apoptosis of the CCs, drive the dynamics of the TPs far from equilibrium. On times less than the CC division times, the TPs exhibit sub-diffusive behavior (the mean square displacement, with βTP < 1). Surprisingly, in the long-time limit, the motion of the TPs is hyper-diffusive ( with αTP > 2) due to persistent directed motion for a number of CC division times. In contrast, CC proliferation randomizes their motion resulting from jamming at short times to super-diffusive behavior, with αCC exceeding unity, at long times. Surprisingly, the effect of the TPs on CC dynamics and radial pressure is negligible, suggesting that the TPs are reliable reporters of the CC microenvironment.