Table 1.

Comparative analysis in terms of mechanical and degradation properties of the eNFs wound dressings based on polysaccharide.

Polysaccharide	Mechanical Properties/Flexibility/Elasticity	Degradation Properties
I. Algae Origin Polysaccharides
Alginates (Alg) SA (sodium alginate)	-blending with synthetic polymers-PEO or PVA or natural polymers (cellulose nanocrystals, pullulan etc.) can enhance the mechanical potency of alginate [82]; -crosslinking with calcium chloride improves nanofiber hydrophilicity [82]; -human platelet lysate loading of PUL/SA eNFS affected scaffold stiffness by enhancing system deformation and by decreasing their elasticity [83].	-drug release from nanofibers can be realized by penetration from pores, drug desorption from the surface, or by matrix degradation [84]. -when honey is used as a bioactive substance, after Alg/PVA eNFs were immersed in PBS, the honey has dissolved, resulting in the degradation of eNFs and core-structure shattering for water-uptake, thus, diminishing the water absorption capacity [85].
II. Plant Origin Polysaccharides
Starch (S)	-the mechanical features of starch eNFs from pure starch are poor but can be improved by the addition of actives molecules such as carvacrol [86] or by association with pullulan, which helps the electrospinning process and ameliorates the fiber morphologies [87].	-the hydroxyl groups in starch structure enhance the water absorption and crosslinking process lowers water uptake and implicitly the degradation rate [88]; -the addition of antioxidants intends to bypass thermal degradation of polymers during manufacturing [86].
Cellulose CA (Cellulose acetate)	-the tensile strength/Young’s modulus values of cellulose eNFs could be increased by heat/chemical treatment, because during heat treatment eNFs gets crosslinked, so reaching at crossover points will lead to the bonding of nanofibers [89].	-in vitro degradation and drug release study revealed that cellulose eNFs are absorbable-degradable barriers, so they are prospective bio-degradable drug release devices [89]. -by adding silver-sulfadiazine (SSD) the thermal degradation of CA nanofibers was increased [90];
Pectins (PCT)	-if the PCT eNFs are subjected to prior oxidation or crosslinking reactions such as calcium chloride or adipic acid dihydrazide [91] then an improvement of the mechanical properties has been observed together with a reduction of the release of the incorporated active substances [92].	-the high density of crosslinking will result in a reduction of swelling and elasticity, which can cause the appearance of brittle gels at the moment of degradation for the eNFs derived from PCT [92].
Gums GA (Gum Arabic) Iranian Gum Tragacanth (IGT)	-co-solvent (glycerol) or partner polymers such as PVA, PEO, PCL by increasing the surface tension will facilitate the formation of eNFS derived from different gums [93]; -emulsifiers and thermal post-treatment can contribute to the improvement of mechanical attributes of gums derived eNFs [94];	-GA/PCL eNFs indicated degradation with environmental pH variation by decreasing the pH into the acidic range, beneficial in wound healing [95]. -high percentage of IGT confers superior mechanical, chemical stability, and degradation of IGT/PVA eNFs [96]. -green tea extract (catechin) substantially increased the thermal stability of PVA/Gum azivash eNFs, resulting in an augmented thermal degradation temperature [97].
III. Animal Origin Polysaccharides
Chitosan (CS)	-the association with synthetic polymers-PEO, PVA, PCL or biopolymers (gelatin, silk sericin, alginates, hyaluronic acid etc.) can enhance the mechanical characteristics and in the same time can improve considerabily the electrospinning process of chitosan based eNFs [98,99];	-combining synthetic polymer (PVA) with CS for the formation of CS/PVA eNFs incorporating honey as bioactive agent, TGA analysis showed a 2 phase degradation, the first weight-loss corresponding with the PVA degradation (250 °C) and the second one (350 °C) with the chitosan ones [100].
Hyaluronic acid (HA)	-similar with CS, many studies demonstrated improved mechanical features of the HA-nanofibers obtained by means of electrospinning when HA it was blend with other biopolymers (collagen, starch, gelatin, chitosan) and synthetic polymers (PVA, PEO, PU, PLGA) [101]; -PCL/HA nanofibers showed down-regulated collagen I expression and an up-regulated collagen III expression together with proper mechanical properties for wound application [102].	-due to the rapid and high in vitro/in vivo degradation of HA a periodic replacement of wound dressing is necessary, which can conduct to the formation of new lesions, enhanced risk of infection and suffering to the patient [101]; -to overcome the above-mentioned drawback the eNFs can incorporate biomolecules such as adhesive proteins (fibrinogen, fibronectin) or antimicrobial agents (natural products, antibiotics, silver nanoparticles) [103].
IV. Fungal Origin Polysaccharides
Pullulan (PUL)	-for the formation of PUL eNFs the association with proteins (pea protein) solution together with thermal cross-linking has indicated good mechanical properties [104]; -biopolymer (chitosan, sodium alginate) association with PUL was also reported for the development of eNFs with suitable mechanical attributes for the use as wound dressings [83,105].	-composite eNFs have different degradation comportment than the eNFs formed from pure PUL eNFs owing to the covalent bonds formation by the crosslinking with other biopolymer (chitosan) or biomolecules (tannic acid); -the composite eNFs reveals unstable thermal stability with onset decomposition at approx. 185 °C, lower than the onset degradation temperature of pure PUL eNFs (about 250 °C) [105].
Schizophyllan (SPG)	-SPG and PVA blend indicated a tensile strength of nanofibrous mat with great similarity with to the tensile strength of natural skin [60].	-vapor cross-linking process with glutaraldehyde will lead to bead-free SPG eNFs characterized by a degradation rate suitable for wound healing application [60].
V. Bacterial Origin Polysaccharides
Dextran (DXT)	-DXT, water-soluble biopolymer with low mechanical strength and by association with other polymers (PVA, PU, PCL), can improve the mechanical properties of DXT eNFs [106].	-cross-linking is imperative for tailoring DXT biodegradation stability, and the simple mixing with boric acid will lead to a gradual surface degradation discharge [107].
Xanthan Gum (XG)	-XG rheological and mechanical properties are improved at the addition of formic acid and at the association with CS for XG eNFs formation [108].	-XG treated at high ionic strengths facilitated more mechanical degradation due to the more rigid molecules in ascending order, which showed an effective stress [77].