Development and evaluation of axially aligned nanofibres for blood vessel tissue engineering.
Biodegradable polymers have been extensively used as scaffolds to regenerate lost tissues. The geometry of the three-dimensional (3D) scaffolds has an influence on the cellular behaviour. In this study, we have developed 3D-scaffolds of axially aligned nanofibres of poly(lactic acid) (PLA), poly(caprolactone) (PCL) and PLA:CL (50:50) with diameters in the range 100-400 nm, internal diameter 4 mm, length 4 cm and wall thickness 0.2 mm, by using a dynamic collector. PCL and PLA:CL nanofibres were significantly less hydrophobic than PLA nanofibres. The porosity of PCL (16.23 ± 9.88%) and PLA:CL nanofibres (14.77 ± 3.41%) were comparable, while PLA (6.57 ± 1.54%) nanofibres had lower porosity. The tensile strength and Young's modulus of PLA was significantly lower than PCL and PLA:CL nanofibres and the suture retention strengths of all three scaffolds were comparable. After 4 weeks, the molecular weight of PLA nanofibres was reduced by 53% compared to 44% and 41% for PCL and the PLA:CL nanofibres, respectively. However, the PLA:CL nanofibres maintained their structural integrity even after 28 days. Platelet adhesion studies showed that PCL nanofibres had least tendency to be thrombogenic, while PLA:CL blend nanofibres were highly thrombogenic. Further, in vitro responses such as cell adhesion, proliferation and gene expression of human umbilical vascular endothelial cells (HUVECs) were evaluated. After 6 days of culture, the surfaces of all the three scaffolds were completely covered with cells. Our results demonstrate that expression levels of elastin, angiopoietin, laminin-4α and -5α were upregulated in PCL and PLA:CL nanofibres without the addition of any exogenous factors.
Centre for Nanotechnology & Advanced Biomaterials, School of Chemical and Biotechnology, SASTRA University, Thanjavur, 613 401, Tamil Nadu, India.
Krishna Kumar
KK
Sankaran
Kirthanashri Srinivasan
KS
Vasanthan
Uma Maheswari
UM
Krishnan
Swaminathan
S
Sethuraman
D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects / Q000502:physiology*; D002152:Calorimetry, Differential Scanning; D002448:Cell Adhesion / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D019344:Lactic Acid / Q000494:pharmacology; D008422:Materials Testing; D008970:Molecular Weight; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D010973:Platelet Adhesiveness / Q000187:drug effects; D011091:Polyesters / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology; D016062:Porosity; D060888:Real-Time Polymerase Chain Reaction; D012756:Sheep; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*
D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; D019344:Lactic Acid; C033616:poly(lactide); D007770:L-Lactate Dehydrogenase