# An Overview on Atomization and Its Drug Delivery and Biomedical Applications
## 8 Biomedical Applications  
Electrospray atomization can be applied in different fields like food processing, drug delivery, cell encapsulation, sensing, diagnostic and therapeutic imaging, implant coating, tissue engineering, vaccine delivery, etc. Figure 7 represents a graphical abstract of electro-spraying and its different biomedical applications. Some examples for each application are discussed below. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Techniques** & **Merits** & **Challenges** & **Ref** \\ \hline \multirow{4}{*}{Electrospray} & One step process; confined particle size that is & \multirow{4}{*}{Low yield; sometimes requires cross-linking} \\  & micro and nanoparticles; polymers with higher & & factors; advancing the technique for bulk \\  & molecular weights can be employed; surfactant & & manufacturing is not possible \\  & free; utilizes less solvents; drugs that are slightly & & \\  & soluble in water can be processed & & \\ \hline \multirow{2}{*}{Spray drying} & Develops inorganic polymeric microparticles; & Uses higher temperature gases as transporter; & \\  & scale-up production & & denatures heat sensitive substances & [90; 91] \\ \hline \multirow{3}{*}{Nanoprecipitation} & Easy procedure; nanoparticles generated by & \multirow{3}{*}{Utilizes substantial amount of solvent; drug} \\  & desorption; efficiently encloses hydrophobic & & loaded in the particles are low \\  & drugs; surfactant free & & \\ \hline \multirow{3}{*}{Emulsion solvent vaporization} & Adaptable technique; generates diverse & Only uses low molar mass polymers; not free of \\  & biomolecular particles & surfactants and solvents; not a single step & \\  & technique; wide range of particle size & \\ \hline \multirow{2}{*}{Sheet by sheet fabrication} & Accurate; multi-tiered particles; uniform sheet & \multirow{2}{*}{Tiresome and lengthy process; advancing the } \\  & thickness; regulated drug delivery & technique for bulk manufacturing is not possible & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparing electrospray to other common techniques. Figure 7: Graphical abstract of electrospray and its applications; reproduced from [94]. In order to attain a very fine and uniform coating of chocolate, [PERSON] et al. studied the electro hydrodynamic atomization process on chocolate and they obtained a very thin coating of the chocolate [95]. They also studied the atomization of Theobroma oil and lauric oil in the presence of electric fields and obtained a better coverage compared with other coating techniques [96]. [PERSON] et al. developed a microparticle using electrospray for the application of drug delivery systems. He used a hydrophobic drug, paclitaxel as the core of the system and enclosed this with a shell made up of PLGA polymer. The highlight of this study was he obtained a constant release of the drug for around 30 days [97]. Another group developed the same microparticles and was used for treating tumour cells by injecting these drug loaded particles under the skin of laboratory-bred albino nude mice. They found that the particles with a drug-loading efficiency of 20% showed a better performance and within 10 days of administration, the growth of the tumour was reduced significantly [98]. Another application of electrospray technique is the encapsulation of cells for various purposes. [PERSON] et al. developed a microparticle using the principle of electro hydrodynamic atomization, in which the core part contained the neuroblastoma rat cells which was enclosed in an alginate shell. They studied the viability and proliferation of the encapsulated cell [99]. [PERSON] et al. encapsulated Hep G2 into the calcium alginate beads using the dripping mode of electrospray atomization. They varied the voltage applied at the syringe needle and observed variation in the size of the microparticles and also in the frequency of the working fluid to drip from the needle. When the voltage was high, the system generated smaller droplets and an increase in the dripping frequency [100].