Compressed Fluids, Porous Polymers and Tissue Engineering

Biodegradable porous polymers with interconnected pores of sub-micrometers to a few hundred micrometers find many applications in emerging technology areas such as tissue engineering, controlled drug delivery, and biochemical sensors. However, most of the current fabrication processes involve organic solvents and chemical blowing agents that may cause environmental concerns and leave residues harmful to biological cells. This paper presents a solvent free fabrication approach for biodegradable porous polymers. Ultrasound cavitation is introduced after the solid state foaming process to produce open cell structures. The material used in this study is polylactic acid (PLA). It belongs to a family of biodegradable polymers that can be used for tissue engineering scaffolds. In order to identify suitable conditions to apply ultrasound, a saturation and foaming study is conducted for the PLA-CO2 gas polymer system. The effects of various process variables are discussed.

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Toward the Fabrication of Hierarchically-Structured Porous Polymers for Tissue Engineering Scaffords

Manufacturing Engineering and Materials Handling, Parts A and B ◽

10.1115/imece2005-81140 ◽

2005 ◽

Author(s):

Hai Wang ◽

Wei Li

Keyword(s):

Tissue Engineering ◽

Focused Ultrasound ◽

Acoustic Power ◽

High Intensity Focused Ultrasound ◽

Acoustic Energy ◽

Porous Polymer ◽

Porous Polymers ◽

Heating Effect ◽

Foaming Process ◽

Transfer Behavior

Hierarchically-structured porous polymers play an important role in scaffold-based tissue engineering. However, the fabrication of these polymers presents a significant challenge because of the requirements of controllable pore size, distribution and interconnectivity. In this work, we report on a novel porous polymer fabrication method using high-intensity focused ultrasound (HIFU). The measurements of both spatial and temporal temperature field are reported for biocompatible PMMA (polymethyl methacrylate) samples insonated with a 1.1 MHz/3.3 MHz HIFU transducer. The acoustic power and insonation duration were both varied. The results have shown that HIFU has a dramatic heating effect on polymers: the temperature increasing rate can exceed 20°C/second and the final temperature can be higher than 120°C. This rapid, localized heating effect is exploited to foam CO2 saturated PMMA samples selectively and generate hierarchical microstructures. The created microstructures were characterized using the scanning electron microscopy (SEM). The results have shown that the amount and rate of acoustic energy dissipation during the HIFU insonation directly affect the polymer foaming process. Preliminary theoretical modeling of the acoustic field and heat transfer behavior in the porous polymers are also presented.

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Smart Materials for Tissue Engineering

10.1039/9781788010542 ◽

2017 ◽

Cited By ~ 22

Keyword(s):

Tissue Engineering ◽

Smart Materials

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Controlling the in vitro differentiation of embryonic stem cells for myocardial tissue engineering applications

Cell Biology International ◽

10.1042/cbi20090021 ◽

2009 ◽

Author(s):

Dong-Bo Ou ◽

Rui Chen ◽

Xiong-Tao Liu ◽

Jing-Jing Guo ◽

Hong-Tao Wang ◽

...

Keyword(s):

Tissue Engineering ◽

Stem Cells ◽

Embryonic Stem Cells ◽

Embryonic Stem ◽

Myocardial Tissue ◽

In Vitro Differentiation ◽

Engineering Applications ◽

Myocardial Tissue Engineering

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Decellularized bone extracellular matrix in skeletal tissue engineering

Biochemical Society Transactions ◽

10.1042/bst20190079 ◽

2020 ◽

Vol 48 (3) ◽

pp. 755-764

Author(s):

Benjamin B. Rothrauff ◽

Rocky S. Tuan

Keyword(s):

Tissue Engineering ◽

Bone Regeneration ◽

Tissue Regeneration ◽

Animal Studies ◽

Tumor Resection ◽

Regenerative Capacity ◽

Skeletal Tissue ◽

Large Bone

Bone possesses an intrinsic regenerative capacity, which can be compromised by aging, disease, trauma, and iatrogenesis (e.g. tumor resection, pharmacological). At present, autografts and allografts are the principal biological treatments available to replace large bone segments, but both entail several limitations that reduce wider use and consistent success. The use of decellularized extracellular matrices (ECM), often derived from xenogeneic sources, has been shown to favorably influence the immune response to injury and promote site-appropriate tissue regeneration. Decellularized bone ECM (dbECM), utilized in several forms — whole organ, particles, hydrogels — has shown promise in both in vitro and in vivo animal studies to promote osteogenic differentiation of stem/progenitor cells and enhance bone regeneration. However, dbECM has yet to be investigated in clinical studies, which are needed to determine the relative efficacy of this emerging biomaterial as compared with established treatments. This mini-review highlights the recent exploration of dbECM as a biomaterial for skeletal tissue engineering and considers modifications on its future use to more consistently promote bone regeneration.

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