414
R. Mankamna Kumari et al.
The small size and large surface area provide enhanced bioavailability and increased
ability to cross the blood-brain barrier and pulmonary system (Kohane 2007). In
addition, the new formulation can give a new life to those drugs in the market that are
unmarketable due to their low solubility and bioavailability along with toxicity and
other side effects. Currently, NPs for drug delivery are synthesized using synthetic or
natural polymers besides inorganic materials, as they can be easily customized and
targeted to the specific site along with increased bioavailability and controlled release
of the drug in the physiological system (Onoue et al. 2014). The targeted approach of
drug delivery is mainly achieved by either active or passive route. Passive delivery of
drugs is achieved by the small size of NPs and enhanced permeability retention effect
owing to high vascularization and permeability of solid tumors (Boylan et al. 2012;
Harris et al. 2001). In case of active targeting, ligand grafted NPs are used for its
specific binding to cancer cells (Fig. 1). In addition to drug molecules, various nucleic
acids have also been explored, such as plasmid DNA, oligonucleotides, miRNA, and
siRNA. The limiting factor for the direct delivery of nucleic acids is its high negative
charge (Elsabahy et al. 2011; Gao et al. 2011; Guo et al. 2010). Thus, to overcome
this barrier, cationic lipids and polymers are employed for the delivery of nucleic
acids owing to their high biocompatibility and biodegradability (Bhavsar et al. 2012;
Xiong et al. 2011).
Fig. 1 Represents the uptake of ligand conjugated nanoparticles by the targeted tumor cells
R. Mankamna Kumari et al.
The small size and large surface area provide enhanced bioavailability and increased
ability to cross the blood-brain barrier and pulmonary system (Kohane 2007). In
addition, the new formulation can give a new life to those drugs in the market that are
unmarketable due to their low solubility and bioavailability along with toxicity and
other side effects. Currently, NPs for drug delivery are synthesized using synthetic or
natural polymers besides inorganic materials, as they can be easily customized and
targeted to the specific site along with increased bioavailability and controlled release
of the drug in the physiological system (Onoue et al. 2014). The targeted approach of
drug delivery is mainly achieved by either active or passive route. Passive delivery of
drugs is achieved by the small size of NPs and enhanced permeability retention effect
owing to high vascularization and permeability of solid tumors (Boylan et al. 2012;
Harris et al. 2001). In case of active targeting, ligand grafted NPs are used for its
specific binding to cancer cells (Fig. 1). In addition to drug molecules, various nucleic
acids have also been explored, such as plasmid DNA, oligonucleotides, miRNA, and
siRNA. The limiting factor for the direct delivery of nucleic acids is its high negative
charge (Elsabahy et al. 2011; Gao et al. 2011; Guo et al. 2010). Thus, to overcome
this barrier, cationic lipids and polymers are employed for the delivery of nucleic
acids owing to their high biocompatibility and biodegradability (Bhavsar et al. 2012;
Xiong et al. 2011).
Fig. 1 Represents the uptake of ligand conjugated nanoparticles by the targeted tumor cells