Limits...
Lipid Coated Microbubbles and Low Intensity Pulsed Ultrasound Enhance Chondrogenesis of Human Mesenchymal Stem Cells in 3D Printed Scaffolds

View Article: PubMed Central - PubMed

ABSTRACT

Lipid-coated microbubbles are used to enhance ultrasound imaging and drug delivery. Here we apply these microbubbles along with low intensity pulsed ultrasound (LIPUS) for the first time to enhance proliferation and chondrogenic differentiation of human mesenchymal stem cells (hMSCs) in a 3D printed poly-(ethylene glycol)-diacrylate (PEG-DA) hydrogel scaffold. The hMSC proliferation increased up to 40% after 5 days of culture in the presence of 0.5% (v/v) microbubbles and LIPUS in contrast to 18% with LIPUS alone. We systematically varied the acoustic excitation parameters—excitation intensity, frequency and duty cycle—to find 30 mW/cm2, 1.5 MHz and 20% duty cycle to be optimal for hMSC proliferation. A 3-week chondrogenic differentiation results demonstrated that combining LIPUS with microbubbles enhanced glycosaminoglycan (GAG) production by 17% (5% with LIPUS alone), and type II collagen production by 78% (44% by LIPUS alone). Therefore, integrating LIPUS and microbubbles appears to be a promising strategy for enhanced hMSC growth and chondrogenic differentiation, which are critical components for cartilage regeneration. The results offer possibilities of novel applications of microbubbles, already clinically approved for contrast enhanced ultrasound imaging, in tissue engineering.

No MeSH data available.


Related in: MedlinePlus

(a) 1, 3 and 5-day hMSC proliferation with 3-min LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs pulse length) and 0.5% MB suspension (Data are mean ± StdEM, n = 9). Microscopic images of hMSC growth two days after LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs) pulse length). (b) Control, (c) LIPUS, (d) LIPUS with 0.5% (v/v) MB suspension. Values significantly different from the control group are indicated by *for p < 0.05 and **for p < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5121887&req=5

f5: (a) 1, 3 and 5-day hMSC proliferation with 3-min LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs pulse length) and 0.5% MB suspension (Data are mean ± StdEM, n = 9). Microscopic images of hMSC growth two days after LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs) pulse length). (b) Control, (c) LIPUS, (d) LIPUS with 0.5% (v/v) MB suspension. Values significantly different from the control group are indicated by *for p < 0.05 and **for p < 0.01.

Mentions: Consequently, we conducted 1, 3 and 5-day hMSC proliferation with LIPUS excitation in the presence of 0.5% (v/v) MB. We divided the samples into three groups: control (no LIPUS, no MB), LIPUS only, and LIPUS and MB. At predetermined time points, the cell viability was measured by an MTS assay with the results shown in Fig. 5(a). A significant increase in cell proliferation (p < 0.01) was observed with LIPUS treatment in the presence of optimal MB suspension after 1, 3 and 5 days of culture. hMSC proliferation enhanced up to 40% compared to the control (without MB and LIPUS) after 5 days of culture in the presence of MB and LIPUS while this value was only 18% when excited with LIPUS alone.


Lipid Coated Microbubbles and Low Intensity Pulsed Ultrasound Enhance Chondrogenesis of Human Mesenchymal Stem Cells in 3D Printed Scaffolds
(a) 1, 3 and 5-day hMSC proliferation with 3-min LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs pulse length) and 0.5% MB suspension (Data are mean ± StdEM, n = 9). Microscopic images of hMSC growth two days after LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs) pulse length). (b) Control, (c) LIPUS, (d) LIPUS with 0.5% (v/v) MB suspension. Values significantly different from the control group are indicated by *for p < 0.05 and **for p < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5121887&req=5

f5: (a) 1, 3 and 5-day hMSC proliferation with 3-min LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs pulse length) and 0.5% MB suspension (Data are mean ± StdEM, n = 9). Microscopic images of hMSC growth two days after LIPUS (30 mW/cm2; 1.5 MHz; 20% duty cycle; 200 μs) pulse length). (b) Control, (c) LIPUS, (d) LIPUS with 0.5% (v/v) MB suspension. Values significantly different from the control group are indicated by *for p < 0.05 and **for p < 0.01.
Mentions: Consequently, we conducted 1, 3 and 5-day hMSC proliferation with LIPUS excitation in the presence of 0.5% (v/v) MB. We divided the samples into three groups: control (no LIPUS, no MB), LIPUS only, and LIPUS and MB. At predetermined time points, the cell viability was measured by an MTS assay with the results shown in Fig. 5(a). A significant increase in cell proliferation (p < 0.01) was observed with LIPUS treatment in the presence of optimal MB suspension after 1, 3 and 5 days of culture. hMSC proliferation enhanced up to 40% compared to the control (without MB and LIPUS) after 5 days of culture in the presence of MB and LIPUS while this value was only 18% when excited with LIPUS alone.

View Article: PubMed Central - PubMed

ABSTRACT

Lipid-coated microbubbles are used to enhance ultrasound imaging and drug delivery. Here we apply these microbubbles along with low intensity pulsed ultrasound (LIPUS) for the first time to enhance proliferation and chondrogenic differentiation of human mesenchymal stem cells (hMSCs) in a 3D printed poly-(ethylene glycol)-diacrylate (PEG-DA) hydrogel scaffold. The hMSC proliferation increased up to 40% after 5 days of culture in the presence of 0.5% (v/v) microbubbles and LIPUS in contrast to 18% with LIPUS alone. We systematically varied the acoustic excitation parameters&mdash;excitation intensity, frequency and duty cycle&mdash;to find 30&thinsp;mW/cm2, 1.5&thinsp;MHz and 20% duty cycle to be optimal for hMSC proliferation. A 3-week chondrogenic differentiation results demonstrated that combining LIPUS with microbubbles enhanced glycosaminoglycan (GAG) production by 17% (5% with LIPUS alone), and type II collagen production by 78% (44% by LIPUS alone). Therefore, integrating LIPUS and microbubbles appears to be a promising strategy for enhanced hMSC growth and chondrogenic differentiation, which are critical components for cartilage regeneration. The results offer possibilities of novel applications of microbubbles, already clinically approved for contrast enhanced ultrasound imaging, in tissue engineering.

No MeSH data available.


Related in: MedlinePlus