Biology subjects

Polanek, M.

Publications and source records attributed to Polanek, M..

4 recordsLinked to original sources

bioRxiv2026

Reciprocal macrophage-MSC crosstalk drives immunomodulatory and regenerative phenotypes in a mineralized collagen scaffold

Critical sized craniomaxillofacial bone defects do not heal naturally and often exhibit chronic inflammatory responses that restrict regeneration. It is increasingly apparent that biomaterials must facilitate dynamic crosstalk between immune cells, such as macrophages, and osteoprogenitors to resolve inflammation and accelerate regeneration. Here, we evaluate interactions between macrophages in a neutral (M0) or pro-inflammatory (M1) state with mesenchymal stem cells (MSCs) in a basal or licensed state within a mineralized collagen scaffold. We reveal that MSC-macrophage crosstalk influences significant changes in osteoprogenitor cell differentiation and immune cell polarization. Notably, crosstalk between MSCs and macrophages drives an early-stage inflammatory response, which enhances the immunomodulatory activity of MSCs via secretion of IL-6, an effect that is heightened for already licensed MSCs. The presence of macrophages in the co-cultures upregulated osteogenic (ALPL, BMP2, COL1A2, and RUNX2) and angiogenic genes (ANGPT1) in basal MSC groups. Further, MSC-macrophage interactions subsequently drive increased M2-like macrophage polarization as early as 7 days of culture, as indicated by surface marker expression. These findings show that biomaterial scaffolds can be leveraged as mediators of MSC-mediated immunomodulation with an emphasis on achieving early-stage pro-inflammatory phenotypes that drive subsequent macrophage polarization and markers of increased regenerative potency.

bioengineering↗

bioRxiv2026

Mineralized collagen scaffold pore architecture and glycosaminoglycan content biases anti-inflammatory macrophage phenotype

Macrophages play a central role in early immune response after injury that can shape the success or failure of craniomaxillofacial (CMF) bone repair. While mineralized collagen glycosaminoglycan (GAG) scaffolds have been developed to support osteogenesis, here we define how scaffold pore size, pore alignment, and glycosaminoglycan (GAG) composition influence human monocyte-derived macrophage polarization. We establish flow cytometry, secretome, and gene expression benchmarks to assess primary macrophage polarization toward M1 versus M2 phenotypes in response to cytokine cocktails in 2D culture and 3D scaffolds. We then define the kinetics macrophage polarization in response to scaffold pore architecture and composition in the absence of exogenous cytokines. All scaffold variants support an early pro-inflammatory response followed by a shift toward M2-like phenotypes over seven days reflected by increased CD206 expression, secretion of pro-healing factors such as CCL18, and upregulation of M2a- and M2c-associated genes. Anisotropic scaffolds with smaller pores more robustly drove angiogenic and extracellular matrix related gene expression as well as earlier emergence of M2-like phenotypes. Scaffold GAG chemistry provided an additional tuning mechanism, with chondroitin-6-sulfate variants promoting the greatest late-stage M2 surface marker expression, heparin variants accelerating early M2 and pro-angiogenic phenotypes, and chondroitin-4-sulfate variants dampening both M1 and M2 phenotypes at early timepoints. These findings demonstrate that mineralized collagen scaffolds intrinsically guide macrophage polarization toward pro-regenerative states but that scaffold structure and composition can be used to shape the kinetics and intensity of these responses. These insights provide a critical foundation for immuno-instructive biomaterial designs that enhance CMF bone repair.

bioengineering↗

bioRxiv2023

DONOR VARIABILITY IN HUMAN MESENCHYMAL STEM CELL OSTEOGENIC RESPONSE AS A FUNCTION OF PASSAGE CONDITIONS AND DONOR SEX

Contemporary tissue engineering efforts often seek to use mesenchymal stem cells (MSCs) due to their potential to differentiate to various tissue-specific cells and generate a pro-regenerative secretome. While MSC differentiation and therapeutic potential can differ as a function of matrix environment, it may also be widely influenced as a function of donor-to-donor variability. Further, effects of passage number and donor sex may further convolute the identification of clinically effective MSC-mediated regeneration technologies. We report efforts to adapt a well-defined mineralized collagen scaffold platform to study the influence of MSC proliferation and osteogenic potential as a function of passage number and donor sex. Mineralized collagen scaffolds broadly support MSC osteogenic differentiation and regenerative potency in the absence of traditional osteogenic supplements for a wide range of MSCs (rabbit, rat, porcine, human). We obtained a library of bone marrow and adipose tissue derived stem cells to examine donor-variability of regenerative potency in mineralized collagen scaffolds. MSCs displayed reduced proliferative capacity as a function of passage duration. Further, MSCs showed significant sex-based differences. Notably, MSCs from male donors displayed significantly higher metabolic activity and proliferation while MSCs from female donor displayed significantly higher osteogenic response via increased alkaline phosphate activity, osteoprotegerin release, and mineral formation in vitro. Our study highlights the essentiality of considering MSC donor sex and culture expansion in future studies of biomaterial regenerative potential.

bioengineering↗

bioRxiv2022

Soluble extracts from amnion and chorion membranes improve hMSC osteogenic response in a mineralized collagen scaffold

Craniomaxillofacial (CMF) bone injuries present a major surgical challenge and cannot heal naturally due to their large size and complex topography. Approximately 26% of injured Iraq war veterans sustained CMF injuries in the form of blast wounds, and 0.1% of births involve CMF defects like cleft palate. We previously developed a class of mineralized collagen scaffolds designed to mimic native extracellular matrix (ECM) features of bone. These scaffolds induce in vitro human mesenchymal stem cell (hMSC) osteogenic differentiation and in vivo bone formation without the need for exogenous osteogenic supplements. Here, we seek to enhance cellular bioactivity and osteogenic activity via inclusion of placental-derived products in the scaffold architecture. The amnion and chorion membranes are distinct components of the placenta that individually have displayed anti-inflammatory, immunogenic, and osteogenic properties. They represent a potentially powerful compositional modification to the mineralized collagen scaffolds to improve bioactivity. Here we examine introduction of the placental-derived amnion and chorion membranes or soluble extracts derived from these membranes into the collagen scaffolds, comparing the potential for these modifications to improve hMSC osteogenic activity. We report structural analysis of the scaffolds via mechanical compression testing, imaging via scanning electron microscopy (SEM), and assessments of various metrics for osteogenesis including gene expression (Nanostring), protein elution (ELISA), alkaline phosphatase (ALP) activity, inductively coupled plasma mass spectrometry (ICP) for mineralization, and cell viability (AlamarBlue). Notably, a post fabrication step to incorporate soluble extracts from the amnion membrane induces the highest levels of metabolic activity and performs similarly to the conventional mineralized collagen scaffolds in regard to mineral deposition and elution of the osteoclast inhibitor osteoprotegerin (OPG). Together, these findings suggest that mineralized collagen scaffolds modified using elements derived from amnion and chorion membranes, particularly their soluble extracts, represent a promising environment conducive to craniomaxillofacial bone repair.

bioengineering↗