scholarly journals In situ miRNA delivery from a hydrogel promotes osteogenesis of encapsulated mesenchymal stromal cells

2019 ◽  
Author(s):  
James. Carthew ◽  
Surakshya. Shrestha ◽  
John. S. Forsythe ◽  
Ilze. Donderwinkel ◽  
Vinh. X. Truong ◽  
...  

AbstractHydrogels have many properties that emulate biological tissues and are therefore attractive candidates for use in tissue engineering. In particular the encapsulation and subsequent differentiation of mesenchymal stem/stromal cells (MSCs) is a strategy that holds great promise for the repair and regeneration of bone and cartilage. However, MSCs are well-known for their sensitivity to mechanical cues, particularly substrate stiffness, and so the inherent softness of hydrogels is poorly matched to the mechanical cues that drive efficient osteogenesis. This limits the success of bone tissue engineering using MSCs encapsulated in a hydrogel. One approach to overcome this limitation is to harness mechanotransductive signalling pathways and override the signals cells receive from their environment. Previous reports have shown that the mechanosensitive miRNAs, miR-100-5p and miR-143-3p can enhance MSC osteogenesis, but this required a complex multi-step procedure to transfect, encapsulate and differentiate the cells. In this study, we develop and characterise a facile system for in situ transfection of MSCs encapsulated within a light-crosslinkable gelatin-PEG hydrogel. Comparing the influence of different transfection agents and hydrogel compositions, we determine the factors affecting transfection agent release and MSC transfection, showing that it is possible to transfect MSCs with miRNAs in situ. We then compare the efficacy of both pretransfection and in situ transfection on the osteogenic capacity of hydrogel-encapsulated MSCs, demonstrating superior mineralisation and osteogenic gene expression for in situ transfected samples. Our platform therefore demonstrates a simple, one-pot system for delivery of pro-osteogenic miRNAs and in situ transfection that is able to enhance MSC osteogenic potential without the need of multi-step transfection procedures, thus demonstrating significant promise for bone tissue engineering.

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3825
Author(s):  
Mauro Petretta ◽  
Alessandro Gambardella ◽  
Giovanna Desando ◽  
Carola Cavallo ◽  
Isabella Bartolotti ◽  
...  

Multifunctional and resistant 3D structures represent a great promise and a great challenge in bone tissue engineering. This study addresses this problem by employing polycaprolactone (PCL)-based scaffolds added with hydroxyapatite (HAp) and superparamagnetic iron oxide nanoparticles (SPION), able to drive on demand the necessary cells and other bioagents for a high healing efficiency. PCL-HAp-SPION scaffolds with different concentrations of the superparamagnetic component were developed through the 3D-printing technology and the specific topographical features were detected by Atomic Force and Magnetic Force Microscopy (AFM-MFM). AFM-MFM measurements confirmed a homogenous distribution of HAp and SPION throughout the surface. The magnetically assisted seeding of cells in the scaffold resulted most efficient for the 1% SPION concentration, providing good cell entrapment and adhesion rates. Mesenchymal Stromal Cells (MSCs) seeded onto PCL-HAp-1% SPION showed a good cell proliferation and intrinsic osteogenic potential, indicating no toxic effects of the employed scaffold materials. The performed characterizations and the collected set of data point on the inherent osteogenic potential of the newly developed PCL-HAp-1% SPION scaffolds, endorsing them towards next steps of in vitro and in vivo studies and validations.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 287
Author(s):  
Ye Lin Park ◽  
Kiwon Park ◽  
Jae Min Cha

Over the past decades, a number of bone tissue engineering (BTE) approaches have been developed to address substantial challenges in the management of critical size bone defects. Although the majority of BTE strategies developed in the laboratory have been limited due to lack of clinical relevance in translation, primary prerequisites for the construction of vascularized functional bone grafts have gained confidence owing to the accumulated knowledge of the osteogenic, osteoinductive, and osteoconductive properties of mesenchymal stem cells and bone-relevant biomaterials that reflect bone-healing mechanisms. In this review, we summarize the current knowledge of bone-healing mechanisms focusing on the details that should be embodied in the development of vascularized BTE, and discuss promising strategies based on 3D-bioprinting technologies that efficiently coalesce the abovementioned main features in bone-healing systems, which comprehensively interact during the bone regeneration processes.


2021 ◽  
Vol 71 ◽  
pp. 101515
Author(s):  
Antoine Berbéri ◽  
Mohammad Fayyad-kazan ◽  
Sara Ayoub ◽  
Rita Bou Assaf ◽  
Joseph Sabbagh ◽  
...  

2005 ◽  
Vol 898 ◽  
Author(s):  
Devendra Verma ◽  
Rahul Bhowmik ◽  
Bedabibhas Mohanty ◽  
Dinesh R Katti ◽  
Kalpana S Katti

AbstractInterfaces play an important role in controlling the mechanical properties of composites. Optimum mechanical strength of scaffolds is of prime importance for bone tissue engineering. In the present work, molecular dynamics simulations and experimental studies have been conducted to study effect of interfacial interactions on mechanical properties of composites for bone replacement. In order to mimic biological processes, hydroxyapatite (HAP) is mineralized in presence of polyacrylic acid (PAAc) (in situ HAP). Further, solid and porous composites of in situ HAP with polycaprolactone (PCL) are made. Mechanical tests of composites of in situ HAP with PAAc have shown improved strain recovery, higher modulus/density ratio and also improved mechanical response in simulated body fluid (SBF). Simulation studies indicate potential for calcium bridging between –COO− of PAAc and surface calcium of HAP. This fact is also supported by infrared spectroscopic studies. PAAc modified surfaces of in situ HAP offer means to control the microstructure and mechanical response of porous composites. Nanoindentation experiments indicate that apatite grown on in situ HAP/PCL composites from SBF has improved elastic modulus and hardness. This work gives insight into the interfacial mechanisms responsible for mechanical response as well as bioactivity in biomaterials.


2011 ◽  
Vol 26 (8) ◽  
pp. 1035-1049 ◽  
Author(s):  
Federico Foschi ◽  
Enrico Conserva ◽  
Paolo Pera ◽  
Barbara Canciani ◽  
Ranieri Cancedda ◽  
...  

2011 ◽  
Vol 5 (2) ◽  
pp. 104-111 ◽  
Author(s):  
Isabel B. Leonor ◽  
Márcia T. Rodrigues ◽  
Manuela E. Gomes ◽  
Rui L. Reis

2007 ◽  
Vol 42 (12) ◽  
pp. 4183-4190 ◽  
Author(s):  
Yusuf M. Khan ◽  
Emily K. Cushnie ◽  
John K. Kelleher ◽  
Cato T. Laurencin

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