Drug Delivery Methods, Applications and A New Horizon of Conjugated Drugs
Authors: Goswami Jayita 
Published: April 2020

Diseases and drugs are an inevitable part of our lives. People use several techniques to make the drug efficient. Biological molecules are chiral molecules; such as proteins, sugar, fat, hormones etc. Most of the market available drugs are chiral drugs. It can be either isomer or in enantiomeric form. Pure enantiomers are hard to produce. Now molecular techniques are more efficient to deliver drugs in proper places. Every cellular mechanism is energy driven. Phosphorylation helps with energetic reactions. During epigenetic changes methylation and acetylation takes place. New cancer or Alzheimer’s drug target this acetylation or methylation sites. Peptides can be attached with drugs for better penetration in cells or for the stability. Polyarginine is an efficient amino acid that helps with penetration. Amino acid Arginine helps with cell penetration. Peptide drug attached with nano particle taking attention recently. Dendrimers (branched polymer), chitin, dextrose has used for drug delivery purposes. PEGylation helps the drug to get into the blood for long time. It is biodegradable. siRNA or miRNA is now widely used to silence genes. Hydrophilic double stranded siRNA is negatively charged, and it can be packaged with positively charged nano‐particles. Quantum dot technology is used very often in nanotechnology. Now it’s application has started for drug delivery purposes. Some plant viruses are ineffective in human, and it is a good cargo for drugs. DNA and in situ hybridization is an effective technique for target‐specific drugs. Nano particle like gold, mesoporous silica nanoparticles carry positive surface charge get attached with negatively charged DNA very tightly, and helps to deliver deep inside the cell. Novel metals are good molecular cargo. Chitosan is a polycationic polymer and dissolves easily in an acidic environment. It has capability to release drug slowly and that makes it a good vehicle for drug delivery. miRNA are microRNAs, people have started using those RNAs to silence disease‐specific genes. Quantum dots are gaining popularity due to its less toxicity, surfactant‐free attachment and target specific delivery. New emerging drug delivery method started using fullerene (C60) and its dendrimers. The carbon atoms of fullerene do not attach with surrounding carbon atoms; these characteristics make it a good vehicle for drugs. Carbon‐hydrogen (C‐H) bond breaks down much faster than carbon‐carbon (C‐C) bonds. This property holds the fullerene structure intact.

Polyethyleneimine can be tagged with nucleic acid or nano particle. DNA wrapped with magnetic nano particles and several natural polymers are getting importance for efficient drug delivery purposes. RNA, peptidoglycan, carbohydrate, fullerene, hydrogel is some of the examples. Artificially synthesized peptides can be a good source of drug.

Enzymes and metabolic biosynthetic pathway go through a reduced and oxidized state and carry cellular electricity. Various protein complex takes part in it. Quorum sensing and biofilm formation is related to microbial biomolecule secretion. Highly reduced state creates atomic oxygen which eventually perturbs protein stoichiometry and agglutination and electron transport.

Support or Funding Information

Former Funding and Institutional Affiliation ASU, NIH/NIDDK, BSU, BMC, Advanced Laboratory, DaryGold, DARPA.