Increased deformations are dispensable for encapsulated cell mechanoresponse in engineered bone analogs mimicking aging bone marrow

Alexander M. Regner; Maximilien DeLeon; Kalin D. Gibbons; Sean Howard; Derek Q. Nesbitt; Seyedeh F. Darghiasi; Anamaria G. Zavala; Trevor J. Lujan; Clare K. Fitzpatrick; Mary C. Farach-Carson; Danielle Wu; Gunes Uzer

Mechanobiology in Medicine (Mar 2025)

Increased deformations are dispensable for encapsulated cell mechanoresponse in engineered bone analogs mimicking aging bone marrow

Alexander M. Regner,
Maximilien DeLeon,
Kalin D. Gibbons,
Sean Howard,
Derek Q. Nesbitt,
Seyedeh F. Darghiasi,
Anamaria G. Zavala,
Trevor J. Lujan,
Clare K. Fitzpatrick,
Mary C. Farach-Carson,
Danielle Wu,
Gunes Uzer

Affiliations

Alexander M. Regner: Mechanical and Biomedical Engineering Department, Boise State University, USA
Maximilien DeLeon: Department of Diagnostic and Biomedical Sciences, UTHealth Houston School of Dentistry, USA; Department of Bioengineering, Rice University, USA
Kalin D. Gibbons: Mechanical and Biomedical Engineering Department, Boise State University, USA
Sean Howard: Mechanical and Biomedical Engineering Department, Boise State University, USA
Derek Q. Nesbitt: Biomedical Engineering Program, Boise State University, USA
Seyedeh F. Darghiasi: Biomedical Engineering Program, Boise State University, USA
Anamaria G. Zavala: Mechanical and Biomedical Engineering Department, Boise State University, USA
Trevor J. Lujan: Mechanical and Biomedical Engineering Department, Boise State University, USA
Clare K. Fitzpatrick: Mechanical and Biomedical Engineering Department, Boise State University, USA
Mary C. Farach-Carson: Department of Diagnostic and Biomedical Sciences, UTHealth Houston School of Dentistry, USA; Department of Bioengineering, Rice University, USA; Department of Biosciences, Rice University, USA
Danielle Wu: Department of Diagnostic and Biomedical Sciences, UTHealth Houston School of Dentistry, USA; Department of Bioengineering, Rice University, USA
Gunes Uzer: Mechanical and Biomedical Engineering Department, Boise State University, USA; Corresponding author. Boise State University, Department of Mechanical & Biomedical Engineering, 1910 University Drive, MS-2085, Boise, ID 83725-2085, USA.

Journal volume & issue: Vol. 3, no. 1
p. 100097

Abstract

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Aged individuals and astronauts experience bone loss despite rigorous physical activity. Bone mechanoresponse is in-part regulated by mesenchymal stem cells (MSCs) that respond to mechanical stimuli. Direct delivery of low intensity vibration (LIV) recovers MSC proliferation in senescence and simulated microgravity models, indicating that age-related reductions in mechanical signal delivery within bone marrow may contribute to declining bone mechanoresponse. To answer this question, we developed a 3D bone marrow analog that controls trabecular geometry, marrow mechanics and external stimuli. Validated finite element (FE) models were developed to quantify strain environment within hydrogels during LIV. Bone marrow analogs with gyroid-based trabeculae of scaffold volume fractions (SV/TV) corresponding to adult (25 %) and aged (13 %) mice were printed using polylactic acid (PLA). MSCs encapsulated in migration-permissive hydrogels within printed trabeculae showed robust cell populations on both PLA surface and hydrogel within a week. Following 14 days of LIV treatment (1 g, 100 Hz, 1 h/day), cell proliferation, type-I collagen (Collagen-I) and filamentous actin (F-actin) were quantified for the cells in the hydrogel fraction. While LIV increased all measured outcomes, FE models predicted higher von Mises strains for the 13 % SV/TV groups (0.2 %) when compared to the 25 % SV/TV group (0.1 %). While LIV increased collagen-I volume 34 % more in 13 % SV/TV groups when compared to 25 % SV/TV groups, collagen-I and F-actin measures remained lower in the 13 % SV/TV groups when compared to 25 % SV/TV counterparts, indicating that both LIV-induced strains and scaffold volume fraction (i.e. available scaffold surface) affect cell behavior in the hydrogel phase. Overall, bone marrow analogs offer a robust and repeatable platform to study bone mechanobiology.

Published in Mechanobiology in Medicine

ISSN: 2949-9070 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Medicine: Medicine (General): Medical technology
Website: https://www.sciencedirect.com/journal/mechanobiology-in-medicine

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