This study was supported by the Bulgarian Scientific Fund under Contract &#8470; K&#928;-06 H59/3 and by Scientific Project No. 07/2023 FVM, Trakia University.

1. Synthesis of lignin microparticles
<ol>
	<li>Prepare a 50 mg/mL alkali lignin aqueous solution by dissolving 2.5 g of alkali lignin in 50 mL of ultrapure water on a magnetic stirrer.</li>
	<li>Prepare 1% Tween 80 solution by dissolving 1 mL of Tween 80 in 100 mL of ultrapure water.</li>
	<li>Prepare a 2 M solution of HNO3 by diluting 6.65 mL of 67% HNO3 (density = 1.413 g/mL) with ultrapure water to a final volume of 50 mL.</li>
	<li>Slowly add 15 mL of the 1% Tween 80 solution...

Lignin Micro-/Submicron Particle Synthesis for Bioflavonoid Release

<ol>
	<li>Yu, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lignin+nanoparticles+with+high+phenolic+content+as+efficient+antioxidant+and+sun-blocker+for+food+and+cosmetics.">Lignin nanoparticles with high phenolic content as efficient antioxidant and sun-blocker for food and cosmetics.</a> ACS Sustainable Chem. Eng. 11 (10), 4082-4092 (2023).</li><li>Boarino, A., Klok, H. -. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Opportunities+and+challenges+for+lignin+valorization+in+food+packaging,+antimicrobial,+and+agricultural+applications.">Opportunities and challenges for lignin valorization in food packaging, antimicrobial, and agricultural applications.</a> Biomacromolecules. 24 (3), 1065-1077 (2023).</li><li>Aadil, K., Barapatre, A., Jha, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+characterization+of+Acacia+lignin-gelatin+film+for+its+possible+application+in+food+packaging.">Synthesis and characterization of Acacia lignin-gelatin film for its possible application in food packaging.</a> Bioresour. Bioprocess. 3 (27), 1-11 (2016).</li><li>Sharma, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Valorization+of+lignin+into+nanoparticles+and+nanogel:+characterization+and+application.">Valorization of lignin into nanoparticles and nanogel: characterization and application.</a> Bioresour. Technol. Reports. 18, 101041 (2022).</li><li>Zadeh, E. M., O'Keefe, S. F., Kim, Y. -. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Utilization+of+lignin+in+biopolymeric+packaging+films.">Utilization of lignin in biopolymeric packaging films.</a> ACS Omega. 3 (7), 7388-7398 (2018).</li><li>Beaucamp, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lignin+for+energy+applications+-+state+of+the+art,+life+cycle,+technoeconomic+analysis+and+future+trends+(Critical+Review).">Lignin for energy applications - state of the art, life cycle, technoeconomic analysis and future trends (Critical Review).</a> Green Chem. 24, 8193-8226 (2022).</li><li>Antunes, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+sugarcane+to+skin:+Lignin+as+a+multifunctional+ingredient+for+cosmetic+application.">From sugarcane to skin: Lignin as a multifunctional ingredient for cosmetic application.</a> Int J Biol Macromol. 234, 123592 (2023).</li><li>Garg, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+lignin+nanoparticles+for+cancer+drug+delivery:+An+update.">Applications of lignin nanoparticles for cancer drug delivery: An update.</a> Materials Letters. 311, 131573 (2022).</li><li>Anushikha, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lignin+as+a+UV+blocking,+antioxidant,+and+antimicrobial+agent+for+food+packaging+applications.">Lignin as a UV blocking, antioxidant, and antimicrobial agent for food packaging applications.</a> Biomass Conv. Bioref. , 1-14 (2023).</li><li>Freitas, F. M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=synthesis+of+lignin+nano-+and+micro-particles:+Physicochemical+characterization,+bioactive+properties+and+cytotoxicity+assessment.">synthesis of lignin nano- and micro-particles: Physicochemical characterization, bioactive properties and cytotoxicity assessment.</a> Int J Biol Macromol. 163, 1798-1809 (2020).</li><li>Rismawati, R., Nurdin, I. A., Pradiptha, M. N., Maulidiyah, A., Mubarakati, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+characterization+of+lignin+nanoparticles+from+rice+straw+after+biosynthesis+using+Lactobacillus+bulgaricus.">Preparation and characterization of lignin nanoparticles from rice straw after biosynthesis using Lactobacillus bulgaricus.</a> Journal of Physics: Conference Series. 9th International Seminar on New Paradigm and Innovation of Natural Sciences and its Application. 1524, 012070 (2020).</li><li>Worku, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+lignin+nanoparticles+from+Oxytenanthera+abyssinica+by+nanoprecipitation+method+followed+by+ultrasonication+for+the+nanocomposite+application.">Synthesis of lignin nanoparticles from Oxytenanthera abyssinica by nanoprecipitation method followed by ultrasonication for the nanocomposite application.</a> Journal of King Saud University - Science. 35 (7), 102793 (2023).</li><li>Gala Morena, A., Tzanov, T. z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibacterial+lignin-based+nanoparticles+and+their+use+in+composite+materials.">Antibacterial lignin-based nanoparticles and their use in composite materials.</a> Nanoscale Adv. 4, 4447-4469 (2022).</li><li>Ivanova, D., Nikolova, G., Karamalakova, Y., Marutsova, V., Yaneva, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Water-soluble+alkali+lignin+as+a+natural+radical+scavenger+and+anticancer+alternative.">Water-soluble alkali lignin as a natural radical scavenger and anticancer alternative.</a> Int J Mol Sci. 24 (16), 12705 (2023).</li><li>Ivanova, D., Toneva, M., Simeonov, E., Antov, G., Yaneva, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Newly+synthesized+lignin+microparticles+as+bioinspired+oral+drug-delivery+vehicles:+Flavonoid-carrier+potential+and+in+vitro+radical-scavenging+activity.">Newly synthesized lignin microparticles as bioinspired oral drug-delivery vehicles: Flavonoid-carrier potential and in vitro radical-scavenging activity.</a> Pharmaceutics. 15 (4), 1067 (2023).</li><li>Yaneva, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antimicrobial+potential+of+conjugated+lignin/morin/chitosan+combinations+as+a+function+of+system+complexity.">Antimicrobial potential of conjugated lignin/morin/chitosan combinations as a function of system complexity.</a> Antibiotics. 11, 650 (2022).</li><li>Handral, H. K., Wyrobnik, T. A., Lam, A. T. -. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Emerging+trends+in+biodegradable+microcarriers+for+therapeutic+applications.">Emerging trends in biodegradable microcarriers for therapeutic applications.</a> Polymers. 15 (6), 1487 (2023).</li><li>Figueiredo, P., Lintinen, K., Hirvonen, J. T., Kostiainen, M. A., Santos, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+and+chemical+modifications+of+lignin:+Towards+lignin-based+nanomaterials+for+biomedical+applications.">Properties and chemical modifications of lignin: Towards lignin-based nanomaterials for biomedical applications.</a> Prog. Mater. Sci. 93, 233-269 (2018).</li><li>Tang, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lignin-based+nanoparticles:+a+review+on+their+preparations+and+applications.">Lignin-based nanoparticles: a review on their preparations and applications.</a> Polymers. 12 (11), 2471 (2020).</li><li>Zhao, W., Simmons, B., Singh, S., Ragauskas, A., Cheng, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+lignin+association+to+nano-/micro-particle+preparation:+extracting+higher+value+of+lignin.">From lignin association to nano-/micro-particle preparation: extracting higher value of lignin.</a> Green Chemistry. 18 (21), 5693-5700 (2016).</li><li>Stewart, H., Golding, M., Matia-Merino, L., Archer, R., Davies, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Manufacture+of+lignin+microparticles+by+anti-solvent+precipitation:+Effect+of+preparation+temperature+and+presence+of+sodium+dodecyl+sulfate.">Manufacture of lignin microparticles by anti-solvent precipitation: Effect of preparation temperature and presence of sodium dodecyl sulfate.</a> Food Res Int. 66, 93-99 (2014).</li><li>Beisl, S., Friedl, A., Miltner, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lignin+from+micro-+to+nanosize:+Applications.">Lignin from micro- to nanosize: Applications.</a> Int. J. Mol. Sci. 18, 2367 (2017).</li><li>Mishra, P. K., Ekielski, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+method+to+synthesize+lignin+nanoparticles.">A simple method to synthesize lignin nanoparticles.</a> Colloids Interfaces. 3, 52 (2019).</li><li>Qian, Y., Deng, Y., Qiu, X., Li, H., Yang, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+uniform+colloidal+spheres+from+lignin,+a+renewable+resource+recovered+from+pulping+spent+liquor.">Formation of uniform colloidal spheres from lignin, a renewable resource recovered from pulping spent liquor.</a> Green Chem. 16, 2156-2163 (2014).</li><li>Tardy, B. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lignin+nano-+and+microparticles+as+template+for+nanostructured+materials:+formation+of+hollow+metal-phenolic+capsules.">Lignin nano- and microparticles as template for nanostructured materials: formation of hollow metal-phenolic capsules.</a> Green Chem. 20, 1335-1344 (2018).</li><li>Silva, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Paraquat-loaded+alginate/chitosan+nanoparticles:+preparation,+characterization+and+soil+sorption+studies.">Paraquat-loaded alginate/chitosan nanoparticles: preparation, characterization and soil sorption studies.</a> J Haz Mat. 190 (1-3), 366-374 (2011).</li><li>Georgieva, N., Yaneva, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+evaluation+of+natural+and+acid-modified+layered+mineral+materials+as+rimifon-carriers+using+UV/VIS,+FTIR,+and+equilibrium+sorption+study.">Comparative evaluation of natural and acid-modified layered mineral materials as rimifon-carriers using UV/VIS, FTIR, and equilibrium sorption study.</a> Cogent Chem. 1 (1), 1-16 (2015).</li><li>Zhang, P., Chen, D., Li, L., Sun, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Charge+reversal+nano-systems+for+tumor+therapy.">Charge reversal nano-systems for tumor therapy.</a> J Nanobiotechnol. 20, 31 (2022).</li><li>Yaneva, Z. L., Georgieva, N. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Removal+of+diazo+dye+from+the+aqueous+phase+by+biosorption+onto+ball-milled+maize+cob+(BMMC)+biomass+of+Zea+mays.">Removal of diazo dye from the aqueous phase by biosorption onto ball-milled maize cob (BMMC) biomass of Zea mays.</a> Maced. J. Chem. Chem. Eng. 32 (1), 133-149 (2013).</li><li>Zatorska, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug-loading+capacity+of+polylactide-based+micro-+and+nanoparticles+-+Experimental+and+molecular+modeling+study.">Drug-loading capacity of polylactide-based micro- and nanoparticles - Experimental and molecular modeling study.</a> Int J Pharmaceutics. 591, 120031 (2020).</li><li>Yaneva, Z., Georgieva, N., Grumezescu, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+5+-+Physicochemical+and+morphological+characterization+of+pharmaceutical+nanocarriers+and+mathematical+modeling+of+drug+encapsulation/release+mass+transfer+processes.">Chapter 5 - Physicochemical and morphological characterization of pharmaceutical nanocarriers and mathematical modeling of drug encapsulation/release mass transfer processes.</a> Nanoscale Fabrication, Optimization, Scale-Up and Biological Aspects of Pharmaceutical Nanotechnology. , 173-218 (2018).</li><li>Yaneva, Z., Georgieva, N., Staleva, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+d,l-&#945;-tocopherol+acetate/zeolite+carrier+system:+equilibrium+study.">Development of d,l-&#945;-tocopherol acetate/zeolite carrier system: equilibrium study.</a> Monatshefte fur Chemie Chemical Monthly. 147 (7), 1167-1175 (2016).</li><li>Yaneva, Z., Georgieva, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+on+the+physical+chemistry,+equilibrium,+and+kinetic+mechanism+of+Azure+A+biosorption+by+Zea+mays+biomass.">Study on the physical chemistry, equilibrium, and kinetic mechanism of Azure A biosorption by Zea mays biomass.</a> Journal of Dispersion Science and Technology. 35 (2), 193-204 (2014).</li></ol>

The authors have no conflicts of interest to disclose.

Among the main critical issues of modern synthesis methodologies for the design of drug-carrier formulations based on biopolymers is the application of hazardous organic reagents - volatile and flammable solvents, such as tetrahydrofuran, acetone, methanol, and even DMSO in high concentrations - which limits their applicability in biomedicine, pharmaceutical industry, and food technology due to the manifestation of possible toxic effects20,21,<sup clas...

Nowadays inclination towards biopolymers such as cellulose, chitosan, collagen, dextran, gelatin, and lignin as precursors for the design of micro-/submicron carriers with customizable size, physicochemical properties, and biofunctionalities has increased in the biomedical, pharmaceutical, and food technology industries due to their applicability in tissue engineering, 3D bioprinting, in vitro disease modeling platforms, packaging industry, emulsion preparation, and nutrient delivery among others1,2,3.
Novel studies highlight the aspects of lignin-based hydrogels as well as micro- and nano- formulations4 as advantageous vehicles used for food packaging materials5, energy storage6, cosmetics7, thermal/light stabilizers, reinforced materials, and drug-carrier matrices8 for the delivery of hydrophobic molecules, improvement of UV barriers9, as reinforcing agents in nanocomposites, and as an alternative to inorganic nanoparticles due to some recent safety issues10,11,12. The reason behind this tendency is the biocompatibility, biodegradability, and non-toxicity of the natural hetero biopolymer, as well as its proven bioactivities of lignin-antioxidant potential and radical scavenging, anti-proliferative, and antimicrobial activities13,14,15,16,17.
Scientific literature reports various methods for synthesis (self-assembly, anti-solvent precipitation, acid precipitation, and solvent shifting)18 and characterization of lignin-based micro-/nano- scaled formulations, including the application of expensive or harmful solvents such as tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and acetone, and complicated, indirect, and tedious processes that use a lot of equipment and toxic substances12,19,20.
To overcome the latter disadvantages, the following protocols present novel methodologies for the synthesis of lignin-based micro-/submicron particles using cheap and green solvents; easy, straightforward, quick, and sensitive processes requiring little equipment, non-toxic substances, and simple methods for their characterization and the determination of encapsulation capacity towards poorly water-soluble bioactive compounds and in vitro release potential of the lignin matrices. The presented lab-scale production methods are advantageous for the manufacture of functional lignin carriers with tunable sizes, high encapsulation capacity, and sustainable in vitro release behavior utilizing simple characterization procedures and eco-friendly chemicals that can find application in various areas of biomedical sciences and food technology. Two flavonoids were applied as target molecules encapsulated into the lignin particles: morin-into the microparticles, and quercetin-into the submicron particles. The difference in the structures of both flavonoids Is only the position of the second -OH group in the B-aromatic ring: the -OH group is on the 2&#39; position in morin and on the 3&#39; position in quercetin, thus both organic compounds are positional isomers. The latter fact presumes similar behavior of both bioactive natural compounds in the processes of encapsulation and/or release.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>automatic-cell counter</td>
			<td>EVE, NanoEnTek</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Citric acid</td>
			<td>Sigma</td>
			<td>251275</td>
			<td>&#160;ACS reagent, &#8805;99.5%</td>
		</tr>
		<tr>
			<td>digital water bath</td>
			<td>Memmert</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf tubes, 1.5-2 mL</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Sigma</td>
			<td>34852-M</td>
			<td>absolute, suitable for HPLC, &#8805;99.8%</td>
		</tr>
		<tr>
			<td>Folin&#8211;Ciocalteu&#8217;s phenol reagent</td>
			<td>Sigma</td>
			<td>F9252</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;freeze dryer</td>
			<td>Biobase</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>gallic acid</td>
			<td>Sigma-</td>
			<td>BCBW7577</td>
			<td>monohydrate</td>
		</tr>
		<tr>
			<td>HCl</td>
			<td>Sigma</td>
			<td>258148</td>
			<td>ACS reagent, 37%</td>
		</tr>
		<tr>
			<td>HNO3</td>
			<td>Sigma</td>
			<td>438073</td>
			<td>&#160;ACS reagent, 70%</td>
		</tr>
		<tr>
			<td>lignin, alkali</td>
			<td>Sigma</td>
			<td>370959</td>
			<td></td>
		</tr>
		<tr>
			<td>morin</td>
			<td>Sigma</td>
			<td>PHL82601</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Sigma</td>
			<td>S9888</td>
			<td>ACS reagent, &#8805;99.0%</td>
		</tr>
		<tr>
			<td>Na2CO3</td>
			<td>Sigma</td>
			<td>223530</td>
			<td>powder, &#8805;99.5%, ACS reagent</td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td>Sigma</td>
			<td>655104</td>
			<td>reagent grade, 97%, powder</td>
		</tr>
		<tr>
			<td>orbital shaker</td>
			<td>IKA</td>
			<td>KS 130 basic</td>
			<td></td>
		</tr>
		<tr>
			<td>pH-meter</td>
			<td>Consort</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>phosphate-buffered saline (PBS)</td>
			<td>Sigma</td>
			<td>RNBH7571</td>
			<td></td>
		</tr>
		<tr>
			<td>Quercetin hydrate</td>
			<td>Sigma</td>
			<td>STBG3815V</td>
			<td></td>
		</tr>
		<tr>
			<td>statistical software for Excel</td>
			<td>Microsoft Corporation</td>
			<td></td>
			<td>XLSTAT&#160; Version 2022.4.5.</td>
		</tr>
		<tr>
			<td>Tween 80</td>
			<td>Sigma</td>
			<td>P8074</td>
			<td>BioXtra, viscous liquid</td>
		</tr>
		<tr>
			<td>ultracentrifuge</td>
			<td>Hermle</td>
			<td>Z 326 K</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultrapure water system</td>
			<td>Adrona</td>
			<td>INTEGRITY+</td>
			<td></td>
		</tr>
		<tr>
			<td>ultrasound homogenizer</td>
			<td>Bandelin Sonopuls</td>
			<td>HD 2070</td>
			<td></td>
		</tr>
		<tr>
			<td>UV/Vis spectrophotometer</td>
			<td>Hach-Lange</td>
			<td>DR 5000</td>
			<td></td>
		</tr>
	</tbody>
</table>

green synthesis, characterization, encapsulation, and measurement of the release potential of novel alkali lignin micro-/submicron particles

The applicability of biopolymer micro-/nano- technology in human, veterinary medicine, pharmaceutical, and food technology is rapidly growing due to the great potential of biopolymer-based particles as effective carrier systems. The use of lignin as a basic heteropolymer biomatrix for the design of innovative micro-/submicron formulations allows the achievement of increased biocompatibility and offers various active functional groups presenting opportunities for customization of the physicochemical properties and bioactivities of the formulations for diverse applications. The aim of the present study was to develop a simple and ecofriendly methodology for the synthesis of lignin particles with micro- and submicron size; to evaluate their physicochemical, spectral, and structural characteristics; and to examine their capacity for encapsulation of biologically active molecules and potential for in vitro release of bioflavonoids in simulated gastrointestinal media. The presented methodologies apply cheap and green solvents; easy, straightforward, quick, and sensitive processes requiring little equipment, non-toxic substances, and simple methods for their characterization, the determination of encapsulation capacity towards the poorly water-soluble bioactive compounds morin and quercetin, and the in vitro release potential of the lignin matrices.

Author Spotlight: Development and Characterization of Eco-Friendly Lignin-Based Microparticles for Enhanced Delivery of Bioflavonoids

Green Synthesis, Characterization, Encapsulation, and Measurement of the Release Potential of Novel Alkali Lignin Micro-/Submicron Particles

The objective of this research was to create a straightforward and environmentally friendly process to produce small lignin particles. The study aimed to analyze their physical, chemical, and structural properties, as well as investigate their ability to encapsulate and release bioflavonoids in stimulated gastrointestinal environments. Our method synthesizes lignin based particles using cheap and green solvents.The process is easy, quick, and requires minimal equipment and non-toxic substances. It also has simple methods for characterization, encapsulation, capacity determination, and in-vitro release potential of poorly water soluble bioactive compounds. The innovative biopolymer microparticles are suitable for oral administration due to the lower risk of gastric irritation.The submicron particles, due to the small size and significant release potential, could be applied as injectable formulations.

An anti-solvent precipitation technique was executed to produce alkali lignin micro-/submicron particles. An aqueous solution of diluted inorganic acid-nitric acid/organic acid-citric acid was dispersed into an alkali lignin aqueous solution, enriched with an eco-friendly surfactant/ethanol, which resulted in the gradual precipitation of the biopolymer solute and, after sonication, a suspension of compact micro-/submicron particles was finally produced (Figure 1).
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We describe novel, simple methodologies of synthesis and characterization of biocompatible lignin micro- and submicron particles. These formulations provide a facile approach for the utilization of the heteropolymer, as well as an alternative for the rational design of multifunctional carrier matrices with potential applicability in biomedicine, pharmaceutical technology, and the food industry.

The applicability of biopolymer micro-/nano- technology in human, veterinary medicine, pharmaceutical, and food technology is rapidly growing due to the ...

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Research

JoVE Journal

Chemistry

338 Views.  Trakia University. The objective of this research was to create a straightforward and environmentally friendly process to produce small lignin particles. The study aimed to analyze their physical, chemical, and structural properties, as well as investigate their ability to encapsulate and release bioflavonoids in stimulated gastrointestinal environments. Our method synthesizes lignin based particles using cheap and green solvents.The process is easy, quick, and requires minimal equipment and non-toxic su...