Table 10.

Advantages and disadvantages of various nanocarriers in drug delivery.

Nanocarrier	Advantages	Disadvantages	Refs.
Liposomes	Less cytotoxic Amphiphilic and Self-assembly capability Can load both hydrophilic and lipophilic drugs High payload Longer duration of action	Could crystallize during long term storage Poor control over the drug release rate Lack of means to prevail biological barriers Sufficient loading of drugs for which pH and ion gradients do not apply Leakage and fusion of loaded drug Phospholipids may undergo oxidation and hydrolysis	[117,118]
Dendrimers	Uniformity in molecular weight, size, shape and branch length A high degree of branching results in a high surface area Availability of internal cavities with Polyvalency offer high loading and targetting High water solubility Biocompatibility and absence of immunogenicity	Complex synthesis process Possibility of incomplete reactions with terminal groups Steric hindrance to the core molecule and dendrons obstructs the formation of high generation dendrimer	[119,120]
Exosomes	Cell targetting anad gene delivery Ability to loading both hydrophilic and lipophilic drugs Exosomes membranes possess many proteins thus show very high organotropism Immunocompatible if derived autologous	Rapid clearance from the blood Current methods available suffer low drug loading and retention Purification and large scale extraction is a hassle	[121,122]
Metal Nanoparticles	Tunable sizes and shapes (spherical, triangular, cubic, rods, starts, etc.) Possibilities of easy functionalization Size-dependent activity	RES uptake might result in low biocompatibility and cytotoxicity Instability of nanoparticles	[88,123]
Mesoporous silica nanoparticles	Ordered porous structure High surface area Tunable pore size and functionalization Poorly water-soluble drugs and gene delivery	More studies are needed on cytotoxicity The presence of high surface silanol groups interacts with the phospholipids of the red blood cell membranes leads to hemolysis	[124,125]
Carbon nanotubes	High surface area, enhanced conductivity and strength Vast functionalization sites Optical properties For targeted delivery	High immunogenicity, carcinogenicity and cytotoxicity Non-biodegradable Poor aqueous solubility and poor absorption	[103,126]
Nanocapsules/nanospheres	Efficient drug accumulation at the target site Controlled release of drug over weeks	Non-degradable polymers accumulate in tissues In vivo metabolism and elimination, routes are not elucidated	[127,128]
Quantum dots	Semiconductor nanocrystals with broad excitation spectra, narrow emission spectra, tunable emission peaks Possess long fluorescence lifetimes and negligible photobleaching Ability to conjugate with proteins and multiple molecular targets simultaneously	Quantum dot degradation result in the leaching of heavy metals such as Cadmium which generates reactive oxygen species (ROS) High cytotoxicity	[129,130,131]
Nanofibers	High specific surface area Multiple drugs with high loading capacity Tunable physicochemical properties Good Spatio-temporal distribution of drugs Great choice of polymers that are biodegradable and biocompatible Designed for various routes of administration for both hydrophilic and hydrophobic drugs	Scalability is an issue Poor control over nanofiber dimensions Need to optimize the solvent system for each polymer in the electrospinning process	[96,132,133,134]