ABSTRACT
Background: Many patients lose their organs or tissues due to disease, trauma, or a variety of genetic disorders. Tissue engineering is a multidisciplinary science to regenerate or restore tissue or organ function and an appropriate scaffold is the first and certainly a crucial step in tissue engineering strategies. Objective: The purpose of this study is to fabricate and evaluate the in-vitro response of porous nano Polycaprolactone (PCL)/ chitosan/ multi-wall carbon nanotube (MWCNTs) scaffold for tissue regeneration. Material and Methods: In this experimental research, a novel scaffold containing MWCNTs in polycaprolactone/chitosan nanofibrous scaffold was synthesized by electrospinning technique. Results: According to scanning electron microscopy SEM images, by increasing the number of MWCNT in the scaffold by 2%, the average diameter decreased significantly for fabricated scaffolds with 5% MWCNTs. Based on the results, the scaffolds plunged from submicron to nanoscale fibers at about 80 nm. In addition, by adding more MWCNT to the nanofibrous scaffold, the biodegradation rate was decreased by 32%. However, mechanical characterization demonstrates that the higher level of MWCNT increases young modulus by 96%, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay illustrated that MWCNTs could enhance bioactivity and cell- scaffold relationship in addition to alkaline phosphatase (ALP). Conclusion: MWCNT significantly improves the physical and mechanical properties of fabricated scaffolds and in-vitro assessment demonstrated that the prepared nanofibrous scaffold containing 4% MWCNT could be a very useful biocompatible material for tissue engineering.
ABSTRACT
Myocardial infarction occurs because coronary arteries insufficiency is one of the major causes of mortality worldwide. Recent studies have shown that tissue engineering of myocardial tissue to regenerate infarcted tissue or engineering of the coronary artery may help overcome this problem. In the present research, gelatin and single-walled carbon nanotube were firstly administrated to physico-chemically and biologically modulate polyurethane nanofibers. Electrospinning, as versatile and effective technique for production of functional nanoscale fiber, was applied. Incorporation of both gelatin and SWNTs reduced mean diameter of nanofibrous scaffolds from 210 to 140 nm, which influenced on initial cell behavior. Possible interaction between gelatin and SWNTs with polyurethane chains was evaluated using FTIR and DSC techniques. Regarding the incorporation of both gelatin and SWNTs, it was found that hydrophilicity of nanofibrous scaffolds dramatically improved. Scaffold degradation profile was adjusted by incorporation of gelatin. Biomimetic mechanical properties of composite scaffolds like normal blood vessel were developed and SWNTs improved the Young modulus and ultimate strength of scaffolds up to 16.47 ± 0.5 and 23.73 ± 0.5 MPa, respectively. However, addition of gelatin increased elongation at break due to its softening effect. The incorporation of the SWNTs led to significant enhancement of electrical conductivity of the scaffolds. Biological evaluation using SEM and MTT assay demonstrated that nanofibrous surface was covered by confluent and dense layer of both myocardial myoblast and endothelial cells after 7 days of culture, which is crucial for cardiovascular tissue engineering. Results verified that the fabricated scaffolds could be effective for cardiovascular tissue engineering.
