9. DNA is known to interfere with DMMB assay. Some of these
effects can be reduced by performing the assay in low pH (3) or
with high detergent and salt concentrations. Some reports
advise the test to be performed in pH (1.5). In such cases,
the standard curve should also be prepared in similar matrices.
Moreover, absorbance should be recorded immediately as otherwise the DMMB-GAG complex starts precipitating.
10. RNA or ssDNA can bind to Quant-iT™ PicoGreen
® reagent,
which can be removed by treating the sample with DNase-free
RNase.
Acknowledgments
This work has been supported by National Science Foundation
Award # 1624515. Pallab Datta acknowledges the Department of
Science and Technology, Government of India, INSPIRE Faculty
Award. The author thanks Dr. Weijie Peng (Penn State University)
for his fruitful insights and Dr. Adil Akkouch (The University of
Iowa) for his assistance with SEM imaging. The authors also thank
Dr. James A. Martin (The University of Iowa) for providing facilities with mechanical testing.
References
1. Dababneh AB, Ozbolat IT (2014) Bioprinting
technology: a current state-of-the-art review. J
Manuf Sci Eng 136:61016. https://doi.org/
10.1115/1.4028512
2. Ozbolat IT (2015) Scaffold-based or scaffoldfree bioprinting: competing or complementing
approaches? J Nanotechnol Eng Med 6:24701.
https://doi.org/10.1115/1.4030414
3. Wu Y, Wong YS, Fuh JYH (2017) Degradation
behaviors of geometric cues and mechanical
properties in a 3D scaffold for tendon repair.
J Biomed Mater Res A 105:1138–1149.
https://doi.org/10.1002/jbm.a.35966
4. Yu Y, Moncal KK, Li J et al (2016) Threedimensional bioprinting using self-assembling
scalable scaffold-free “tissue strands” as a new
bioink. Sci Rep 6:28714
5. Ozbolat IT, Hospodiuk M (2016) Current
advances and future perspectives in extrusionbased bioprinting. Biomaterials 76:321–343.
https://doi.org/10.1016/j.biomaterials.
2015.10.076
6. Ozbolat IT, Moncal KK, Gudapati H (2017)
Evaluation of bioprinter technologies. Addit
Manuf 13:179–200. https://doi.org/10.
1016/j.addma.2016.10.003
7. Gudapati H, Dey M, Ozbolat I (2016) A comprehensive review on droplet-based bioprinting: Past, present and future. Biomaterials
102:20–42.
https://doi.org/10.1016/j.
biomaterials.2016.06.012
8. Murphy SV, Atala A (2014) 3D bioprinting of
tissues
and
organs.
Nat
Biotechnol
32:773–785
9. Peng W, Unutmaz D, Ozbolat IT (2016) Bioprinting towards physiologically relevant tissue
models for pharmaceutics. Trends Biotechnol
34:722–732.
https://doi.org/10.1016/j.
tibtech.2016.05.013
10. Nicholson JK, Connelly J, Lindon JC, Holmes
E (2002) Metabonomics: a platform for studying drug toxicity and gene function. Nat Rev
Drug Discov 1:153–161. https://doi.org/10.
1038/nrd728
11. Yu Y, Zheng H, Buckwalter JA, Martin JA
(2014) Single cell sorting identifies progenitor
cell population from full thickness bovine articular
cartilage.
Osteoarthritis
Cartilage
22:1318–1326.
https://doi.org/10.1002/
nbm.3369
A Scaffold Free 3D Bioprinted Cartilage Model for In Vitro Toxicology
183
effects can be reduced by performing the assay in low pH (3) or
with high detergent and salt concentrations. Some reports
advise the test to be performed in pH (1.5). In such cases,
the standard curve should also be prepared in similar matrices.
Moreover, absorbance should be recorded immediately as otherwise the DMMB-GAG complex starts precipitating.
10. RNA or ssDNA can bind to Quant-iT™ PicoGreen
® reagent,
which can be removed by treating the sample with DNase-free
RNase.
Acknowledgments
This work has been supported by National Science Foundation
Award # 1624515. Pallab Datta acknowledges the Department of
Science and Technology, Government of India, INSPIRE Faculty
Award. The author thanks Dr. Weijie Peng (Penn State University)
for his fruitful insights and Dr. Adil Akkouch (The University of
Iowa) for his assistance with SEM imaging. The authors also thank
Dr. James A. Martin (The University of Iowa) for providing facilities with mechanical testing.
References
1. Dababneh AB, Ozbolat IT (2014) Bioprinting
technology: a current state-of-the-art review. J
Manuf Sci Eng 136:61016. https://doi.org/
10.1115/1.4028512
2. Ozbolat IT (2015) Scaffold-based or scaffoldfree bioprinting: competing or complementing
approaches? J Nanotechnol Eng Med 6:24701.
https://doi.org/10.1115/1.4030414
3. Wu Y, Wong YS, Fuh JYH (2017) Degradation
behaviors of geometric cues and mechanical
properties in a 3D scaffold for tendon repair.
J Biomed Mater Res A 105:1138–1149.
https://doi.org/10.1002/jbm.a.35966
4. Yu Y, Moncal KK, Li J et al (2016) Threedimensional bioprinting using self-assembling
scalable scaffold-free “tissue strands” as a new
bioink. Sci Rep 6:28714
5. Ozbolat IT, Hospodiuk M (2016) Current
advances and future perspectives in extrusionbased bioprinting. Biomaterials 76:321–343.
https://doi.org/10.1016/j.biomaterials.
2015.10.076
6. Ozbolat IT, Moncal KK, Gudapati H (2017)
Evaluation of bioprinter technologies. Addit
Manuf 13:179–200. https://doi.org/10.
1016/j.addma.2016.10.003
7. Gudapati H, Dey M, Ozbolat I (2016) A comprehensive review on droplet-based bioprinting: Past, present and future. Biomaterials
102:20–42.
https://doi.org/10.1016/j.
biomaterials.2016.06.012
8. Murphy SV, Atala A (2014) 3D bioprinting of
tissues
and
organs.
Nat
Biotechnol
32:773–785
9. Peng W, Unutmaz D, Ozbolat IT (2016) Bioprinting towards physiologically relevant tissue
models for pharmaceutics. Trends Biotechnol
34:722–732.
https://doi.org/10.1016/j.
tibtech.2016.05.013
10. Nicholson JK, Connelly J, Lindon JC, Holmes
E (2002) Metabonomics: a platform for studying drug toxicity and gene function. Nat Rev
Drug Discov 1:153–161. https://doi.org/10.
1038/nrd728
11. Yu Y, Zheng H, Buckwalter JA, Martin JA
(2014) Single cell sorting identifies progenitor
cell population from full thickness bovine articular
cartilage.
Osteoarthritis
Cartilage
22:1318–1326.
https://doi.org/10.1002/
nbm.3369
A Scaffold Free 3D Bioprinted Cartilage Model for In Vitro Toxicology
183