Functional nanofiber coating on metal and polymer implants.

Abstract

Electrospun nanofiber is used for wide range of applications in the field of biomedical engineering because of its ease of production. Due to its low cost, biocompatibility, and slow bioresorption, poly-??-caprolactone (PCL) is used as a polymer to produce the nanofiber for various applications. In this Thesis, there are three independent goals. (a) To improve the biomechanical efficiency of a composite hydrogel made with Polyethylene (glycol) Diacrylate (PEGDA) anchored with PCL nanofiber as an implant for disc degenerative disease. (b) To improve the biomechanical efficiency of a titanium implant by altering the surface and treating it with tesryl chloride and fibernectin, (c) Develop an engineered blood vessel for an artery disease. To achieve the first goal, the biomechanical performances of the intervertebral disc (IVD) implant anchored with electrospun nanofiber mesh to the natural and those IVDs made with silicone NP only are compared. The short time (static) compression, rheological, finite element tests using human lumbar spine model showed the potentiality of the disc as a tissue-engineered IVD. The compression test results show that ENAS disc compressive modulus (87.47 ?? 7.56 kPa, n = 3) is significantly higher in comparison to silicone gel (38.75 ?? 2.15 kPa, n = 3) and the value is within the range of the compressive modulus of human NP (64.9 ?? 44.1 kPa). The rheological test results show that ENAS disc compressive modulus (16 ~ 40 kPa) is significantly higher in comparison to silicone gel (0.10 ~ 0.16 kPa) and the value is within the range of the compressive modulus of human NP (7 ~ 20 kPa). Also, we have conducted in vivo biological efficiency using the rat tail IVD model for which our fabricated IVD was implanted on six rat tails. After 28 days of the implantation, the IVD implant has been removed. Micro-computed tomography (??CT) images and histological analysis were conducted to see the disc height and bone growth around the implant. To achieve the second goal, the laser grooved titanium implant coated with PCL nanofibers and the implant which has only laser groove (control) are implanted in the femur of a rabbit. Both the implants are treated with tesrylchloride and fibernectin before nanofiber coating. Histological analysis is done for the implants and the results were compared to that of control implants. The bone growth around the grooved titanium implant is found to be significantly higher to a controlled one. For the third goal, a preliminary study has been carried out and a blood vessel is fabricated using the PCL polymer solution. A simulated blood fluid is passed through the blood vessel and the maximum flow rate of the engineered blood vessel is determined.