## 5 Biomedical Indispensability of the PCL Electrospun Nanocomposites
The ternary system of PCL/graphene oxide/Fe\({}_{3}\)O\({}_{4}\) nanocomposites was prepared by using electrospinning methodology at a constant concentration of Fe\({}_{3}\)O\({}_{4}\) and varying contents of graphene oxide; it was reported that the living cells decreased with the increase of the graphene oxide due to its large surface area, triggered by an increase in the average diameter of the nanofiber [48]. Recently, a considerable amount of research has been conducted on the preparation of different electrospun PCL/nanofiber composites in order to assess the potential biomedical applications in remedying of ailments or for tissue engineering for both in-vivo and in-vitro classifications [49]. For example, [PERSON] and [PERSON] [71] conducted the preparation of PCL/collagen electrospun membranes for use in the wound healing applications. It was reported that the orientation of nanofibers is responsible in facilitating the regeneration of epithelial tissues in order to expedite the healing process of the wounds. The water contact analysis indicated the rapid water uptake, which suggests that the prepared mats can increase the cell adhesion around the affected area. Thus, due to an increased proliferation of the cells, the re-epithelialization phenomenon leads to a swift healing process of the wounds. Figure 4 displays the in-vivo treatment for the healing process of the wound by dressing scarred places with the electrospun PCL/collagen mats. The treatment of PCL/alginate nanocomposites using external electric fields of different capacity will serve as an impetus in the applications of drug delivery, especially for transfection in cell immobilization efficiency. Alginate has been recently considered as one of the most effective nanofibers in biomedical practices on the account that it is able to reduce cytotoxicity and alleviate excessive adsorption imminent between serum protein and cationic polyplexes, therefore this phenomenon will stimulate the transfection for in situ applications. The degradation rates can be controlled by treating PCL/alginate scaffolds with external electric fields so that they could be amenable for the gene immobilization for both gene delivery and tissue regeneration applications. [PERSON] and [PERSON] [74] reported the effect of the treatment of PCL/alginate mats by using external electric fields at different voltages in order to regulate the degradation rate of the scaffolds for the benefit in tissue regenerative applications. It was outlined that the increase of applied voltage reduces the transfection efficiency of scaffolds, thus manipulates the gene transportation caused by gene immobilization capacity. The  
Figure 4: The healing process relative to time of the applied PCL/collagen mats on the rat wound. Left: Comparison of wound closure among five groups. Right: Wound areas at different day points after grafting [71]. Copyrights Elsevier. control of the voltage within the range of 0.5 V to 1 V was found to be essential in providing the excellent effectiveness for gene transfection properties according to Figure 5.  
In recent years, a plethora of PCL/nanofibers and PCL-blend/nanofibers mats prepared by electrospinning technique for use in different biomedical applications including drug delivery, tissue regeneration and cell proliferation has been reported in the literature. The following table collates the indispensability of the electrospun PCL/nanofiber composites, induced by different nanoparticles of various properties and their potential biomedical applications. Selective studies on different nanofillers, component systems and average diameters, are tabulated in Table 3.