Table 4.

List of the molecular moiety and benefits of different nanocarriers.

S. No.	Nanocarriers	Molecular Moiety	Benefits		References
Organic Nanocarriers
1.	Polymeric	PLA, PGA, PLGA, polycaprolactone (PCL) and polyethylene glycol (PEG), chitosan, polysaccharide, gelatin, starch		High biocompatibility, nontoxic by-products within the body and good sustained-release profiles	17, 131
2.	Dendrimers	Polyamidoamine (PAA), Polypropylenimine, Polyaryl ether (PAE)		Capable of encapsulating hydrophilic as well as hydrophobic molecules; Capable to cross various cell membranes or biological barriers, including the BBB through endocytosis	130, 132
3.	Nanogels	Water soluble and Cross-linked polymers like PEG		Greater surface area, unique softness and better drug loading capacity	133
4.	Micelles	L,D-lactine polycaprolactone, PEG		Improved drug stability and bioavailability	86, 134
5.	Liposomes	Spherical vesicles comprising of aqueous core surrounded with single or multiple amphiphilic lipid bilayers		Capable of encapsulating hydrophilic as well as hydrophobic molecules; efficiently delivery of therapeutic molecules, including drugs, vaccines, enzymes, proteins, and nucleic acids, and imaging agents for diagnostics by transcytosis, endocytosis and BBB disruption	131, 135
6.	SLNP	Colloidal nanocarriers comprising of surfactant-stabilized triglycerides, monoglycerides, complex glyceride mixtures, or waxes, hard fats		Enhanced entrapment efficiency for hydrophobic drugs; possess the advantages of both liposomes and polymeric nanoparticles; high physical stability, bioavailability, biocompatibility, drug protection, strict control of release, ease of preparation, efficient tolerance, and biodegradability without generating toxic by-products	136, 137
Inorganic Nanocarriers
1.	Fullerenes	Carbon-based nanomaterial structure; an allotrope of carbon formed as C60 and C70		Antioxidant nature; effective in crossing the BBB when hybridized with a biologically active moiety; prevent disruption and leakage of mitochondrial membrane	132, 139, 142
2.	Graphene	2D single layer of strongly packed carbon atoms; Hydroxyl, epoxyl and carboxyl groups modify the graphene to provide graphene oxide		Antioxidant responses; Anti-inflammatory responses; high drug target specificity; high drug efficiency	148, 150, 153
3.	Carbon Nanotubes	Cylindrical shaped carbon-based nanostructures		Increased surface area; High penetration power; Promotes neuronal activity, network communication and synaptic formation	154
Biological Vectors as Nanocarriers
1.	Viral Vectors	Retrovirus vectors, adenovirus vectors, lentivirus vectors, herpes simplex virus type 1, and adeno-associated virus vectors		Delivers a normal copy of a defective gene and subsequently reduce the harmful functions, thus fighting disease pathology	131, 158
2.	Extracellular Vesicles	Heterogenous cell-derived membrane structures; Exosomes and micro-vesicles		Easily cross BBB by adsorptive/receptor-mediated transcytosis; efficient drug delivery	161, 162