Vignesh Muthuvijayan

In this article, we report the development of graphene oxide (GO) reinforced electrospun poly(carbonate urethane) (PCU) nanocomposite membranes intended for biomedical applications. In this study, we aimed to improve the mechanical properties of PCU fibroporous electrospun membranes through fiber alignment and GO incorporation. Membranes with 1, 1.5, and 3% loadings of GO were evaluated for their morphology, mechanical properties, crystallinity, biocompatibility, and hemocompatibility. The mechanical properties were assessed under both static and dynamic conditions to explore the tensile characteristics and viscoelastic properties. The results show that GO presented a good dispersion and exfoliation in the PCU matrix, contributing to an increase in the mechanical performance. The static mechanical properties indicated a 55% increase in the tensile strength, a 127% increase in toughness for 1.5 wt % GO loading and the achievement of a maximum strength reinforcement efficiency value at the same loading. Crystallinity changes in membranes were examined by X-ray diffraction analysis. In vitro cytotoxicity tests with L-929 fibroblast cells and percentage hemolysis tests with fresh venous blood displayed the membranes to be cytocompatible with acceptable levels of hemolytic characteristics. Accordingly, these results highlight the potential of this mechanically improved composite membrane's application in the biomedical field.

Soft tissues connect, support, or surround other structures and organs of the body, including skeletal muscles, tendon vessels, and nerves supplying these components. Also, organs such as the heart, brain, liver, and kidney are considered as soft tissues. Acute and chronic injury may cause transient or permanent damage to organs and soft tissues. If the damage is severe, the natural physiological repair and restoration mechanisms are not possible. The repair or regeneration using tissue engineered (TE) scaffolds has been considered as a clinical solution. TE approach involves the replacement of damaged parts using grafts made from natural or synthetic or composite polymers. Choosing the polymer with appropriate biological, physicochemical, and mechanical properties is the key to make a successful TE scaffold, and it is still a challenging task. Moreover, the fabrication technique and choice of cells or growth factors for encapsulation to develop the graft also play a crucial role. Therefore, in this chapter, we have highlighted the grafts developed for engineering soft tissues such as blood vessels, skin, cartilage, intervertebral disc, tendon, and skeletal muscle. We have restricted our focus on electrospun scaffolds, and injectable hydrogels prepared using polymers include collagen (Col), chitosan (CS), hyaluronic acid (HA) alginate (Alg), poly(caprolactone) (PCL), poly(lactic acid) (PLA), poly(glycolic-lactic acid) (PLGA), and their composites. This chapter will help the readers to understand the choice of materials and fabrication techniques for developing successful TE scaffolds for soft tissue engineering applications.

The repairing procedure in the nervous system is intricate and brings significant difficulties to investigators. The complication of the structure and function of the nervous system, and its slow rate of regeneration, make it further challenging to treat in comparison to other human tissues when damage takes place. Furthermore, the existing therapeutic modalities comprising the utilization of conventional grafts and pharmacological actives have numerous shortcomings and cannot completely rehabilitate injuries to the nervous system. Though the peripheral nerves regenerate to some extent, the consequent findings are not satisfactory, especially for severe injuries. The continuing functional loss owing to inadequate regeneration of the nerve is a significant problem around the world. Therefore, a successful therapeutic approach to bring functional rehabilitation is immediately required. Lately, tissue engineering methods have enticed many scientists to lead tissue regeneration efficiently. Majorly, the electrospinning method has come into the limelight for the fabrication of the scaffolds as they can develop fibrous meshes with fiber diameter in nanoscale dimensions. The electrospun substrates have a high prospective in mimicking the structure of the natural extracellular matrix. These produced fibers can be random or oriented to assist the extension of neurite via contact guidance. In this book chapter, we have demonstrated the principal parameters necessary for suitable electrospinning. Further, we have discussed the recent advances of electrospun polymeric scaffolds in neural tissue engineering. Finally, the challenges and future potentialities have been addressed.