Hydrogel fibers encapsulating human stem cells in an injectable calcium phosphate scaffold for bone tissue engineering

Abstract

Human induced pluripotent stem cells (hiPSCs), human embryonic stem cells (hESCs) and human umbilical cord MSCs (hUCMSCs) are exciting cell sources for use in regenerative medicine. There has been no report on long hydrogel fibers encapsulating stem cells inside injectable calcium phosphate cement (CPC) scaffold for bone tissue engineering. The objectives of this study were to: (1) develop a novel injectable CPC construct containing hydrogel fibers encapsulating cells for bone engineering, and (2) investigate and compare cell viability, proliferation and osteogenic differentiation of hiPSC-MSCs, hESC-MSCs and hUCMSCs in injectable CPC. The stem cell-encapsulating pastes were fully injectable under a small injection force, and the injection did not harm the cells, compared to cells without injection (p > 0.1). Mechanical properties of stem cell-CPC construct were much higher than previous injectable polymers and hydrogels for cell delivery. hiPSC-MSCs, hESC-MSCs and hUCMSCs in hydrogel fibers in CPC had excellent proliferation and osteogenic differentiation. All three cells yielded high alkaline phosphatase, runt-related transcription factor, collagen I, and osteocalcin expressions (mean ± sd; n = 6). Cell-synthesized minerals increased substantially with time (p < 0.05), with no significant difference among the three types of cells (p > 0.1). Mineralization by hiPSC-MSCs, hESC-MSCs and hUCMSCs in CPC at 14 d was 13-fold that at 1 d. In conclusion, all three types of cells (hiPSC-MSCs, hESC-MSCs and hUCMSCs) in CPC scaffold showed high potential for bone tissue engineering, and the novel injectable CPC construct with cell-encapsulating hydrogel fibers is promising to enhance bone regeneration in dental, craniofacial and orthopedic applications.

Human periodontal ligament stem cells on calcium phosphate scaffold delivering platelet lysate to enhance bone regeneration

“…Further study is needed to seed the hPDLSCs into the interior of the scaffold, for example, via cellencapsulating hydrogel microbeads or bers distributed inside the CPC scaffold. 56,57 The hydrogel microbeads and bers could protect the cells during the CPC paste mixing and CPC setting reaction. Then the microbeads and bers would degrade in a few days to release the cells throughout the CPC scaffold volume.…”

“…Then the microbeads and bers would degrade in a few days to release the cells throughout the CPC scaffold volume. 56,57 Further study is needed to encapsulate hPDLSCs inside hydrogel in CPC to form a three-dimensional (3D) cell-CPC scaffold, as well as to investigate cell-encapsulating scaffolds using 3D printing techniques.…”

TuningForkhead Box D3overexpression to promote specific osteogenic differentiation of human embryonic stem cells while reducing pluripotency in a three‐dimensional culture system

“…All groups were then transitioned to osteogenic medium (basal medium plus 0.1 μM dexamethasone, 50 μg/ml l ‐ascorbic acid 2‐phosphate, and 10 mM β‐glycerophosphate) with or without DOX. Medium was exchanged every other day for a period of 2 weeks, a culture duration selected to be consistent with several previous reports of hESC osteogenic differentiation (Arpornmaeklong et al, ; Hwang et al, ; Hwang et al, ; Wang et al, ). For each study, two separate encapsulation experiments, each with six to eight independent samples per treatment group, were performed.…”

“…In cases where current graft options are unavailable or insufficient, bioengineered bone grafts based on human embryonic stem cells (hESCs) may hold promise as a therapeutic alternative. A prevailing paradigm in hESC‐driven bone repair is to expand and/or differentiate hESCs in two‐dimensional (2D) culture formats, followed by encapsulation into a three‐dimensional (3D) biomaterial platform and culture in osteogenic medium for 2–3 weeks prior to implantation (Chen et al, ; Hwang, Varghese, Lee, Zhang, & Elisseeff, ; Rutledge, Cheng, Pryzhkova, Harris, & Jabbarzadeh, ; Wang et al, ). However, to come to clinical fruition, osteogenic differentiation of hESCs must be a controlled process, as well as time‐ and cost‐efficient (Heng, Cao, Stanton, Robson, & Olsen, ; Kim et al, ; Metallo, Azarin, Ji, De Pablo, & Palecek, ).…”

Induced Pluripotent Stem Cells in Dental and Nondental Tissue Regeneration: A Review of an Unexploited Potential

“…Human iPSCs-MSCs seeded on microporous CPC scaffolds using polyethylene glycol (PEG) particles showed upregulation of RUNX2, COL1A1, ALP, OPN, and platelet-derived growth factor receptor-beta (PDGF-R-β) [76]. Similarly, human iPSCs-MSCs seeded on CPC [62,[77][78][79] or poly lactic-co-glycolic acid/poly L-lactic acid (PLGA/PLLA) scaffold combined with macrophages [80] or fast degradable alginate microbeads [69] showed high expression of osteoblast-related genes. Moreover, murine iPSC-derived MSCs seeded onto three-dimensional gelatin scaffold revealed upregulation of several osteoblast-related genes in vitro and in vivo, following subcutaneous implantation in rats [81].…”