# Lignin to Materials: A Focused Review on Recent Novel Lignin Applications
## 3 Medical Applications
### Pharmaceuticals
Another study presents three steps in which lignocellulose can be depolymerized to form platform chemicals, which can then be used to synthesize biologically active compounds with the use of a DES [32]. The DES used was a mixture of choline chloride and oxal acid. Biologically active compounds that can be synthesized include tetrahydro-2-benzazepines. Tetrahydro-2-benzazepines are present in alkaloids, such as galantamine, that could treat [PERSON]'s disease. In this three-step process, the only by-product was water. Furthermore, biologically active compounds derived in this study were also shown to be effective against _S. aureus_. Figure 3 summarizes the reaction pathway to synthesize biologically active compounds that likely exhibit antibacterial or anticancer activities. Figure 3: Summary of the reaction pathway to synthesize the biologically active compounds. Reprinted with permission from [32]. Copyright (2019) American Chemical Society. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Product** & **Usage** & **Feedstock Lignin** & **Lignin Content (wt \%)** & **Reaction/Process Condition** & **Source** \\ \hline \multirow{2}{*}{Lignophonds} & Potentially prevent & \multirow{2}{*}{Japanese ocular native lignin} & \multirow{2}{*}{N/A} & \multirow{2}{*}{Phase-separation with crossed and sulfuric acid} & [31] \\  & coronary heart disease & & & & \\  & Precursor to the drugs & & & & \\  & Int could treat & & & & \\  & Int could treat & & & & \\  & Alzheimer’s disease & & & & \\ \hline \multirow{4}{*}{Terankhydro-2-benzazephes Alzheimer Alzheimer’s disease} & \multirow{4}{*}{Time and poplar lignocellulosic} & \multirow{4}{*}{N/A} & \multirow{4}{*}{Pouse must addes and 40 bar \(\mathrm{H}_{3G}\) synthesis of product,} \\  & & & & & \\  & Deliver methotrexate & Sugar cane Bugase & & & \\  & Deliver Sortanelb and & & & & \\  & Benzazine & & & & \\  & & & & & \\  & Drug delivery system & Kraft lignin & Up to 80\% & &  
Materials containing lignin and lignin derivatives can also be effectively used to deliver drugs inside the human body. Perhaps the largest advantages of lignin-based nanoparticles for delivering drugs are their inexpensive and non-toxic properties. For instance, lignins derived from sugarcane can be used as a drug carrier to deliver methotrexate and treat rheumatoid arthritis [33]. Lignin nanoparticles encapsulating iron oxide could effectively deliver Sorafenib and Benzazulene in alkali media [34]. Hydrogels produced from varying concentrations of starch, Kraft lignin, hemicellulose, and citric acid were tested for their ability to deliver drugs effectively [35]. To characterize the performance of these hydrogels, the swelling capability was analyzed because it indicates the crosslinking density and ultimately the amount of water absorbed in the hydrogel. Based on the experiments testing the diffusion of water into the gel, the hydrogel has the potential to swell to 1380% at a pH of 9 and the potential to swell to 345% at a pH of 4. The pH-dependent swelling behavior is desirable for hydrogels, because the diffusion rates of molecules in and out of the gel can be controlled. Since pharmaceutical products are a common source of water pollution, lignin can adsorb these pharmaceuticals to alleviate water pollution. Kraft lignin and \(\alpha\)-chitin powder from crab shells were mixed with hydrogen peroxide to create a sorbent that adsorbed ibuprofen and acetaminophen, which are commonly used drugs that cause water pollution [36]. Figure 4 summarizes the process to construct the biosorbent with a high removal efficiency of ibuprofen and acetaminophen. Several mechanisms for the adsorption process were proposed. One such mechanism was ion\(-\)dipole interactions; there could be electrostatic interaction between pharmaceutical ions and the negatively or positively charged surface of the sorbent surface. Another mechanism could be hydrogen bonds forming between the pharmaceutical drug and the sorbent. Such sorbents can potentially be reused.