Table 2.

Advantages and disadvantages of biomaterials in NTE.

Polymer type	Polymer name	Advantages	Disadvantages	Refs.
Proteins	Collagen	1.High biocompatibility 2.Low antigenicity and cytotoxic response 3.Versatility	1.Poor mechanical properties and structural integrity in hydrogel form	[18,51,52]
	Gelatin	1.Good biocompatibility 2.Low antigenicity	1.Insufficient mechanical properties	[53,54]
Polysaccharides	Hyaluronic acid	1.High water content 2.Safe degraded products 3.Influence wound healing and metastasis	1Lack of cell adhesion sites 2Limited mechanical properties	[55,56]
	Alginate	1.Fast crosslinking property 2.Water solubility 3.Versatility in 3D bioprinting 4.Low cost	1Limited biodegrading capability 2Lack of cellular adhesive binding sites	[57,58]
	Chitosan	1.Biocompatibility and biodegradability 2.Drug delivery capacity	1.Potential toxic risks 2.Low cellular interaction 3.Limited solubility	[59,60]
Synthetic polymers	PCL	1.Biocompatibility 2.Ease of processability 3.Long-term mechanical stability	1.Potential cytotoxic effects of organic solvents 2.Limited bioactivity	[61]
	PLLA	1High surface-to-volume ratio 2High porosity	1.Limited bioactivity 2.Release of acidic products on degradation 3.Poor processability	[62,63]
	PLGA	1.Ease of functionalization 2.Biodegradability	1Low bioactivity 2Deformation on exposure to long-term strain	[64,65]
	PPy	1.Good conductivity 2.Cell adhesion properties 3.Non-mutagenic	1.Insolubility 2.Non-degradability 3.Poor processability	[66]
	Carbon nanotubes	1.Superior conductivity 2.High aspect ratio 3.Mechanical stability	1.Cytotoxicity 2.Non-biodegradability	[67]