Aptamer-based targeted drug delivery systems.

Nano-therapeutics often aims to design site-specific delivery of the therapeutics at the molecular level to treat diseased tissues or organs. On the contrary, both reachability and interaction of these therapeutic active molecules at the delivery site are challenging tasks, and most of the therapeutics are unable to achieve therapeutic efficacy, because of their side effect associated with off-targeting due to limited selectivity. Therefore, to avoid “off-target” delivery, presently aptamer-based drug target delivery systems have emerged as a vital therapeutic option having specific receptor recognition ability. Moreover, the wide range of chemical flexibility and tissue penetration competency of such delivery systems make aptamers suitable candidates for targeted drug delivery. Recently, various cutting-edge aptamer-based technologies received considerable attention due to their wider applicability in therapeutics including chemotherapeutics, peptides, toxins, and oligonucleotides. The objective of this book chapter is to explore aptamer-based targeting strategy as an advanced therapeutic option supported by evidence collected from past and current research progress. The outcome of the current chapter is thoroughly evaluated, discussed, and concluded for the present scenario and future direction considering the aptamer-based drug delivery

Lipid nanoparticles and nanoemulsions exploited in the diagnosis and treatment of infectious diseases.

In the 20th century, the primary option for the treatment of infectious diseases was based on using conventional antibiotics, antivirals, antifungals, antiprotozoals, and anthelminthics drugs. However, these therapies lose their therapeutic value with time due to the development of drug resistance in microorganisms. The concept of immunization is also a well-developed strategy to prevent infectious diseases in humans and other animals, which harness the endogenous disease-fighting immune mechanism. Advancement in nanotechnology transformed the conventional approaches for disease treatment and diagnosis. The nanocarriers are effective in inducing the naïve immune activity against the pathogens/immune diseases and are capable to improve the therapeutic value significantly. Lipid nanoparticles and nanoemulsions having a composition similar to the intrinsic cell membrane are novel vehicles for the delivery of therapeutic compounds in a controlled and temporal manner. Thus, they can improve the medicinal value of therapeutic compounds by improving the specificity up to molecular level target, avoidance of off-target delivery with minimum or no adverse events. The ease of development approaches makes them suitable as a potential tool for disease diagnosis and the delivery of traditional drugs, proteins as well as nucleic acid-based therapeutics. The manipulation of these lipid-based nanocarriers could further help in avoidance of foreign body immune reactions and reticuloendothelial escape (RES) uptake, in addition to high loading and targeting efficiency, enhanced permeation, and retention (EPR), intracellular delivery and lesser toxicity. It enables the lipid nano carriers as the potential tool to combat the infectious diseases. The current chapter is focused on the development of these lipid-based nanocarriers, their diagnostic and therapeutic applications and outlines the possible strategies to improve the scope of lipid-based carriers in infectious diseases