Nanomaterials possess exceptional unique nanoscale size dependent physical, optical, catalytic, electrical, and chemical properties that can be controlled (scalable). These properties are entirely different than their bulk counterpart. One of the exciting feature of nanotechnology is its utility in the field of nanomedicine, therapeutics, and medical devices . When these small size materials are introduced into biological systems, their extremely small size and their unique nanoscale properties make it possible to use them as delivery vectors and probes for biological diagnostics, imaging and therapeutics . Infact, when size decreases, the surface area to volume ratio of materials becomes very large, so that a vast suitable surface is available for chemical interactions with biomolecules. This critically implied that nanotechnology is facing a transition into the tangible advancement of human therapeutics. Recently, we have seen the beginning of multiple clinical trials of nanomaterials; both for therapeutics and for medical devices.
When we talk about nanomedicine, its aim can be broadly defined as the comprehensive production of materials to control, either repair, defence or therapy, and improvement of different human biological systems. For this purpose different nano-engineered structures are applied at molecular level. Here, nanoscale size materials can be included due to their active components in the size range from one nanometre to hundreds of nanometres
Nanomaterials based drug delivery systems can interact with biomolecules positioned on both cell surface and within the cell. Thus nano based drug delivery systems not only transfer encapsulated or grafted chemotherapeutics, but can also deliver them within the cellular system once they have penetrated. Such systems can also be modified and decorated with different functionalizing agents such as antibodies to develop target specific drug delivery system . At present only two families of therapeutic nanomedicine-albumin and liposomes nanoparticles are clinically established worldwide.
Nano Drug Delivery Systems (DDS) generally possess three vector generation; First generation vectors comprising nano spheres and nano capsules. Second generation vectors of nanoparticles that are coated with hydrophilic polymers such as Polyethylene Glycol (PEG). Third generation vectors which combines a biodegradable core and a Polymer Envelope (PEG) with a functionalization agent. Such systems offer inherent merits of protecting drug from being degraded in the body before it is actually delivered to its target, enhance drug absorption, better control over drug distribution to tissue and avoiding side effects by preventing interaction with normal cells. Many FDA approved nanomedicines are available for clinical use