Lignin Nanoparticles Research Articles

Modeling the Production Process of Lignin Nanoparticles Through Anti-Solvent Precipitation for Properties Prediction

Global warming has recently intensified research interest in renewable polymer chemistry, with significant attention directed towards lignin nanoparticle (LNP) synthesis. Despite progress, LNP industrial application faces challenges: (1) reliance on kraft lignin from declining raw biomass processes, (2) sulfur-rich and condensed lignin use, (3) complex lignin macroparticles to LNP conversion, using harmful and toxic solvents, and, above all, (4) lack of control over the LNP production process (i.e., anti-solvent precipitation parameters), resulting in excessive variability in properties. In this work, eco-friendly LNPs with tailored properties were produced from a semi-industrial organosolv process by studying anti-solvent precipitation variables. Using first a parametric and then a Fractional Factorial Design, predictions of LNP sizes and size distribution, as well as zeta-potential, were derived from a model over beech by-products organosolv lignin, depending on initial lignin concentration (x1, g/L), solvent flow rate (x2, mL/min), antisolvent composition (x3, H2O/EtOH v/v), antisolvent ratio (x4, solvent/antisolvent v/v), and antisolvent stirring speed (x5, rpm). This novel chemical engineering approach holds promise for overcoming the challenges inherent in industrial lignin nanoparticle production, thereby accelerating the valorization of lignin biopolymers for high value-added applications such as cosmetics (sunscreen or emulsion) and medicine (encapsulation, nanocarriers), a process currently constrained by significant limitations.

Green synthesis of multifunctional natural rubber-lignin nanocomposites: A sustainable approach for waste reduction

Lignin, a valuable biomaterial having an array of exciting properties is increasingly favoured as a reinforcement material in the fabrication of green composites. Reinforcement in biopolymers like natural rubber (NR) using lignin nanoparticles (LNP) is considered a hotspot today. In this study, LNP synthesized via the homogenization method was incorporated into natural rubber latex (NRL) using probe sonication, and NR/Lignin nanocomposites (NR/LNP) were fabricated using latex dipping method. The addition of LNP resulted in significant enhancements in mechanical and antibacterial properties, biodegradability, and ultraviolet (UV) blocking capabilities with the addition of 7 parts per hundred rubber (phr) of LNP, due to the uniform dispersion and effective interaction between NR and LNP. This research demonstrates a versatile pathway for integrating LNP into NR through a green method, enabling the production of eco-friendly NR nanocomposites for multifunctional applications. This pathway contributes to a safe disposal of NR based products.

The role of lignin as interfacial compatibilizer in designing lignocellulosic-polyester composite films

Advancing nanocomposites requires a deep understanding and careful design of nanoscale interfaces, as interfacial interactions and adhesion significantly influence the physical and mechanical properties of these materials. This study demonstrates the effectiveness of lignin nanoparticles (LNPs) as interfacial compatibilizer between hydrophilic cellulose nanofibrils (CNF) and a hydrophobic polyester, polycaprolactone (PCL). In this context, we conducted a detailed analysis of surface-to-bulk interactions in both wet and dry conditions using advanced techniques such as quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), water contact angle (WCA) measurements, broadband dielectric spectroscopy (BDS), and inverse gas chromatography (IGC).QCM-D was employed to quantify the adsorption behavior of LNPs on CNF and PCL surfaces, demonstrating LNPs’ capability to interact with both hydrophilic and hydrophobic phases, thereby enhancing composite material properties. LNPs showed extensive adsorption on a CNF model film (1186 ± 178 ng.cm−2) and a lower but still significant adsorption on a PCL model film (270 ± 64 ng.cm−2). In contrast, CNF adsorption on a PCL model film was the lowest, with a sensed mass of only 136 ± 35 ng.cm−2. These findings were further supported by comparing the morphology and wettability of the films before and after adsorption, using AFM and WCA analyses. Then, to gain insights into the molecular-level interactions and molecular mobility within the composite in dry state, BDS was employed. The BDS results showed that LNPs improved the dispersion of PCL within the CNF network. To further investigate the impact of LNPs on the composites’ interfacial properties, IGC was employed. This analysis showed that the composite films containing LNPs exhibited lower surface energy compared to those composed of only CNF and PCL. The presence of LNPs likely reduced the availability of surface hydroxyl groups, thus modifying the physicochemical properties of the interface. These changes were particularly evident in the heterogeneity of the surface energy profile, indicating that LNPs significantly altered the interfacial characteristics of the composite materials.Overall, these findings emphasize the necessity to control the interfaces between components for next-generation nanocomposite materials across diverse applications.

One‐Pot Synthesis of (S)‐Flavanones by a Double‐Face Promiscuous Chemo‐Enzymatic Cascade of Lipases

AbstractThe one‐pot stereoselective synthesis of (S)‐flavanones from 2′‐hydroxyacetophenone and substituted aromatic aldehydes was obtained by a double‐face promiscuous chemo‐enzymatic cascade of porcine pancreas and Mucor javanicus lipases. The reaction pathway comprises: A) cross‐aldol condensation catalysed by porcine pancreas lipase to yield chalcone intermediates; B) unprecedented intramolecular oxa‐Michael addition of chalcone intermediates to (S)‐flavanones. Mucor javanicus lipase was the most effective enzyme in step B. Imidazole and 2‐methylimidazole were studied as additive in order to improve the efficacy of the overall transformation. The sustainability of the chemo‐enzymatic cascade was increased by immobilization of lipases on cross‐linked hydroxy‐methylated kraft lignin nanoparticles, by use of concanavalin A. Immobilization conferred considerable stability and reusability at the system for 4 runs. Noteworthy, the reaction mixture was significantly enriched in (S)‐flavanones under both homogeneous and heterogeneous conditions. Computational studies encompassing docking and molecular dynamic analyses showed the role played by evolutionary conserved oxyanion holes and catalytic triad of Mucor javanicus lipase in the stereocontrol of the intra‐molecular oxa‐Michael addition.

Lignin-based flame retardant via sequential purification-nanoparticle formation, and N[sbnd]P coupled chemical modification

A nonhalogenated and ecofriendly flame-retarding material was developed using lignin, one of the main components of lignocellulosic biopolymers. Lignin was purified, dissolved, and formulated as nanoparticles and implemented after processing in an ecofriendly water-based γ-valerolactone (GVL) system at different concentrations. Nitrogen‑phosphorus sequential chemical modification was performed using polyethyleneimine (PEI) and phytic acid (PA), The char residue increased by ≥10 % compared with lignin nanoparticles (LNPs). A 10 wt% lignin-based flame retardant (L-FR) based on the weight of cotton fabric was introduced using a simple dipping method. Compared to existing cotton fabrics, the combustion time of L-FR treated cotton fabrics was reduced by 6.8 s. The maximum flame height was reduced by 5.4 cm, and the charcoal residue increased by 25 %. The flame-retarding mechanism of L-FR involved low-temperature dehydration, thermal decomposition of cellulose by the phosphorus component of PA and generation of expansive gas by the nitrogen component of PEI. These results showed that lignin-based raw material processing, polymer processing, and chemical modification were biomass-based, suggesting that lignin could be converted into an ecofriendly flame retardant, highlighting the feasibility of high-value-added lignin.

Sustainable Nanofluids Constructed from Size-Controlled Lignin Nanoparticles: Application Prospects in Enhanced Oil Recovery.

Lignin, a widely available, cost-effective, and structurally stable natural polymer, has recently attracted significant attention due to its diverse potential applications. A promising approach is to prepare lignin nanoparticles (LNPs) as a substitute for conventional nanoparticles to fulfill a variety of functions. In this study, LNPs with controlled size, regular morphology, and excellent dispersibility were synthesized by using industrial alkali lignin. The antisolvent method was employed, utilizing an aqueous solution of the anionic surfactant sodium apolyolefin sulfonate (AOS) as the antisolvent. Subsequently, the prepared LNPs were used to formulate nanofluids in combination with AOS and nonionic surfactant coconut diethanolamide (CDEA). The incorporation of LNPs has significantly enhanced the interfacial activity of the resulting nanofluids, thereby improving their emulsion stabilization, spreading on quartz surfaces, and oil droplet removal capabilities, which establish a strong foundation for the AOS/CDEA/LNPs nanofluid to achieve high performance in enhanced oil recovery (EOR), which was validated through microscopic visual physical model experiments. The quartz crystal microbalance with the dissipation monitoring (QCM-D) technique was employed to investigate the adsorption of surfactants onto quartz surfaces. It was found that the incorporation of LNPs significantly reduces the adsorption loss of surfactants, presenting a potential solution to overcome the challenges associated with surfactant adsorption in chemically enhanced oil recovery (EOR) processes, such as high cost and unreliable efficiency. This study reveals the good performance of LNPs/surfactant nanofluids and provides a potential approach to the advancement of green, sustainable, and intelligent EOR technologies.

Green synthesis of polyphenol-grafted lignin nanoparticles and their application as sustainable anti-acne, antioxidant, and UV-blocking agents

Acne is a persistent infectious skin condition primarily caused by Propionibacterium acne that affects 80 % of teenagers. The rise of antibiotic resistance in P. acnes has led to an increasing interest in exploring alternative antimicrobial agents. This study explored the effects of natural polyphenol (gallic and tannic acid)-grafted lignin nanoparticles on P. acnes and other pathogens causing skin infections. The process involved functionalizing lignin by grafting with gallic acid and tannic acid using laccase, followed by mechanical homogenization to synthesize lignin-gallic acid (LGAL-NPs) and lignin-tannic acid (LTAL-NPs) nanoparticles. LGAL-NPs and LTAL-NPs exhibited average low polydisperse particles of less than 60 nm and increased total phenolic content. Testing against P. acnes, S. aureus, and S. epidermidis showed that the nanoparticles had an MIC of 0.625 mg/mL. The effectiveness of LGAL-NPs and LTAL-NPs against acne-causing bacteria was attributed to their high phenolic content and nanosize. Furthermore, studies on the mechanism of action have revealed the interaction of LGAL-NPs with bacterial surfaces, destabilization of membranes, increase in ROS levels, and reduction of metabolic activity. Molecular docking results indicated that these nanoparticles effectively inhibited bacterial growth and compromised their pathogenic abilities by targeting and disrupting key virulence factors. Additionally, these nanoparticles exhibited antioxidant and UV-protecting properties, making them potentially useful in the cosmetic and pharmaceutical industries for developing skincare products. Their natural, low toxicity, cost-effective nature, and eco-friendly attributes make them a sustainable option for skincare applications.

One-Step Synthesis of Waterborne Epoxidized Lignin Nanoparticles with High Epoxy Value and Stability for High-Strength Adhesives

One-Step Synthesis of Waterborne Epoxidized Lignin Nanoparticles with High Epoxy Value and Stability for High-Strength Adhesives

Excellent facile fabrication of PVA and lignin nanoparticles from wheat straw after novel DES-THF pretreatment

The utilization of environmental friendly and renewable materials has received increasing attention recently. Lignin nanospheres (LNPs) prepared from recovered lignin and residual lignin after DESs and DESs-THF pretreatment were obtained by self-assembly in the present research. Then, films were prepared by incorporating them into polyvinyl alcohol (PVA) solution. The properties of various films were characterized and compared. Results showed that as the LNPs content increased, the UV blocking capacity of the films was gradually enhanced than PVA film. The DES-THF films showed better antioxidant properties up to 69 % due to higher phenolic hydroxyl content. The hydrophobicity of films incorporated with DESs-THF pretreated lignin was consistently better than that of DES pretreated. DES-THF-M films showed a higher Tmax than that of DES-M films, resulting in better thermal stability. Moreover, DES-THF-L films are lighter in color due to a lower degree of condensation, which is favorable to subsequent applications. The incorporation of LNPs improved mechanical and antioxidant properties, thermal stability, and UV shielding ability of PVA films, especially lignin after DES-THF pretreatment. In conclusion, the prepared PVA/LNPs composite films possessed good functional properties that make them potential for packaging materials.

Efficient synthesis of highly hydrophobic lignin nanoparticles and their application as nano fillers for multifunctional composite membranes

Controlling the hydrophobic behaviors of lignin nanoparticles (LNPs) is crucial and advantageous for their application as film Nano Fillers, yet it poses a significant challenge. Herein, we successfully developed a novel method for the preparation of LNPs with highly hydrophobic behaviors using ternary deep eutectic solution (DES)-H2O systems. The resulting LNPs exhibit a significantly reduced content of hydrophilic groups on their outer surface, leading to a zeta potential value of only −4.9 mV, and up to 140.0° of water contact angle (WCA). Afterwards, a “Dissolution-Restructuration” mechanism was proposed to explain the formation of the prepared LNPs. Firstly, DES demonstrates superior H-bonding capabilities, facilitating the complete disruption of inter- and intramolecular H-bonding in lignin, and resulting in the formation of a highly homogenized lignin network. Subsequently, the DES system undergoes compromise after adding water, triggering the reformation of both inter- and intramolecular H-bonding and π-π interactions. Consequently, lignin orderly self-assembles into LNPs with highly hydrophobic characteristics. Especially, using the as-prepared LNPs as Nano fillers, a series of LNPs-containing polyvinyl alcohol (PVA) films were successfully fabricated, exhibiting exceptional hydrophobic behaviors (with contact angles reaching up to 124.0°). Furthermore, the mechanical strength, UV-shielding capabilities, and biodegradability of the PVA films are significantly enhanced. This study introduces a sustainable and efficient approach for the synthesis of hydrophobic LNPs, thereby facilitating the broadening of applications for lignin-based functional composite film materials.

Eco-friendly synthesis of pure lignin nanoparticle and silver-doped lignin nanoparticle using fig tree bark for photocatalytic degradation of Rhodamine B dye and assessment of their anticancer and antibacterial performance

Lignin nanoparticles (lignin-NPs) have been successfully prepared from the bark of a fig tree by a hydrothermal method for the first time, next, synthesized lignin-NPs were doped with silver (Ag) metal. The Ag-doped lignin-NPs and pure lignin-NPs have been identified through UV–Vis, XRD, FT-IR, and FESEM/EDX techniques. XRD patterns of pure lignin-NPs and Ag-doped lignin-NPs have shown amorphous and crystalline structures respectively. The UV–Vis spectra of NPs presented strong absorption bands in 450, 228, and 289 nm. FESEM images of Ag-doped lignin-NPs and pure lignin-NPs exhibited spherical shapes via sizes of about 18.55 nm and 31.93 nm respectively. Also, the FTIR spectra revealed the same functional groups. Moreover, the photocatalytic performance of NPs for the decolorization of Rhodamine B (RhB) dye has been investigated under UVA light. As a result, Ag-doped lignin-NPs demonstrated a higher degradation percentage than pure lignin-NPs. The results of the MTT assay after 48 h indicate that pure lignin-NPs had little toxicity compared with Ag doped lignin-NPs on normal (L929) and cancer (Huh-7) cells. Also, according to the results of the agar diffusion test, Ag doped lignin-NPs had better antibacterial performance in comparison with pure lignin-NPs on Pseudomonas aeruginosa (POA1 and S7), and Enterococcus faecalis (clinical).

Curcumin-loaded lignin nanoparticles: Exploring sonication effects on drug loading and particle properties for future biomedical use

The present study investigates the effects of sonication and cross-linker (oxalic acid) concentration on drug loading and the properties of curcumin-loaded lignin nanoparticles. Selected samples were further assessed for their toxicity and antioxidant potential using the eukaryotic model organism Saccharomyces cerevisiae. Transmission electron microscopy analyses revealed the formation of spherical nanoparticles with diameters in the range of 39–49 nm. Differential scanning calorimetry experiments confirmed the encapsulation of curcumin. Factorial experimental design analyses indicated that sonication time, wave amplitude, cross-linker concentration, and their interactions significantly influenced both ζ-potential – from (−37.0 ± 1.7) mV to (−48.4 ± 0.6) mV – and curcumin loading – from (3.70 ± 0.32) % to (7.10 ± 0.57) %. These parameters are critical for biomedical applications as they relate to the clearance of nanoparticles from the human bloodstream and drug dosage optimization. Although sonication has been previously reported for the preparation of lignin nanoparticles, this study represents the first documented instance of manipulating drug loading by controlled sonication parameters. While none of the investigated factors significantly affected the mean particle diameter, observations from TEM micrographs suggest that cross-linker concentration and wave amplitude notably influence nanoparticle morphology. Moreover, the curcumin-loaded nanoparticles exhibited non-toxicity toward Saccharomyces cerevisiae and demonstrated the ability to enhance yeast cell tolerance to H2O2-induced oxidative stress, underscoring their antioxidant potential. Therefore, this research significantly contributes to the scientific understanding of how the control of sonication parameters and cross-linkers can modulate the properties of curcumin-loaded lignin nanoparticles for future biomedical applications.

Binary Biomass-Based Electrolyte Films for High-Performance All-Solid-State Supercapacitor.

Solid-state electrolytes have received widespread attention for solving the problem of the leakage of liquid electrolytes and effectively improving the overall performance of supercapacitors. However, the electrochemical performance and environmental friendliness of solid-state electrolytes still need to be further improved. Here, a binary biomass-based solid electrolyte film (LSE) was successfully synthesized through the incorporation of lignin nanoparticles (LNPs) with sodium alginate (SA). The impact of the mass ratio of SA to LNPs on the microstructure, porosity, electrolyte absorption capacity, ionic conductivity, and electrochemical properties of the LSE was thoroughly investigated. The results indicated that as the proportion of SA increased from 5% to 15% of LNPs, the pore structure of the LSE became increasingly uniform and abundant. Consequently, enhancements were observed in porosity, liquid absorption capacity, ionic conductivity, and overall electrochemical performance. Notably, at an SA amount of 15% of LNPs, the ionic conductivity of the resultant LSE-15 was recorded at 14.10 mS cm-1, with the porosity and liquid absorption capacity reaching 58.4% and 308%, respectively. LSE-15 was employed as a solid electrolyte, while LNP-based carbon aerogel (LCA) served as the two electrodes in the construction of a symmetric all-solid-state supercapacitor (SSC). The SSC device demonstrated exceptional electrochemical storage capacity, achieving a specific capacitance of 197 F g-1 at 0.5 A g-1, along with a maximum energy and power density of 27.33 W h kg-1 and 4998 W kg-1, respectively. Furthermore, the SSC device exhibited highly stable electrochemical performance under extreme conditions, including compression, bending, and both series and parallel connections. Therefore, the development and application of binary biomass-based solid electrolyte films in supercapacitors represent a promising strategy for harnessing high-value biomass resources in the field of energy storage.

Design of a hybrid nanoscaled skin photoprotector by boosting the antioxidant properties of food waste-derived lignin through molecular combination with TiO2 nanoparticles

TiO2 nanoparticles loaded with pistachio shell lignin (8 % and 29 % w/w) were prepared by a hydrothermal wet chemistry approach. The efficient interaction at the molecular level of the biomacromolecule and inorganic component was demonstrated by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Visible (UV–Vis), Fourier transform infrared (FT-IR), dynamic light scattering (DLS), and electron paramagnetic resonance (EPR) analysis. The synergistic combination of lignin and TiO2 nanoparticles played a key role in the functional properties of the hybrid material, which exhibited boosted features compared to the separate organic and inorganic phase. In particular, the hybrid TiO2-lignin nanoparticles showed a broader UV–Vis protection range and remarkable antioxidant performance in aqueous media. They could also better protect human skin explants from the DNA damaging effect of UV radiations compared to TiO2 as indicated by lower levels of p-H2A.X, a marker of DNA damage, at 6 h from exposure. In addition, the samples could protect the skin against the structural damage occurring 24 h post UV radiations by preventing the loss of keratin 10. These results open new perspectives in the exploitation of food-waste derived phenolic polymers for the design of efficient antioxidant materials for skin photoprotection in a circular economy perspective.

Lignin Nanoparticles: Transforming Environmental Remediation.

In the face of escalating environmental challenges driven by human activities, the quest for innovative solutions to counter pollution, contamination, and ecological degradation has gained paramount importance. Traditional approaches to environmental remediation often fall short in addressing the complexity and scale of modern-day environmental problems. As industries transition towards sustainable paradigms, the exploration of novel materials and technologies becomes crucial. Lignin nanoparticles have emerged as a promising avenue of exploration in this context. Once considered a mere byproduct, lignin's unique properties and versatile functional groups have propelled it to the forefront of environmental remediation research. This review paper delves into the resurgence of lignin from an environmental perspective, examining its pivotal role in carbon cycling and its potential to address various environmental challenges. The paper extensively discusses the synthesis, properties, and applications of lignin nanoparticles in diverse fields such as water purification and soil remediation. Moreover, it highlights the challenges associated with nanoparticle deployment, ranging from Eco toxicological assessments to scalability issues. Multidisciplinary collaboration and integration of research findings with real-world applications are emphasized as critical factors for unlocking the transformative potential of lignin nanoparticles. Ultimately, this review underscores lignin nanoparticles as beacons of hope in the pursuit of cleaner, healthier, and more harmonious coexistence between humanity and nature through innovative environmental remediation strategies.

Preparation of Alkali-Resistant Lignin Nanospheres Loaded with Silver Nanoparticles and Their Applications Toward Antibiosis and Printing.

Lignin nanoparticles (LNPs) loaded with silver nanoparticles have exhibited significant application potential in antibacterial and catalytic fields. However, the high solubility of LNPs in silver ammonia solution makes it difficult to achieve the reduction of Ag+ and the adsorption of silver nanoparticles. In this study, a protecting agent, terephthalic aldehyde (TA) is used to block lignin condensation and introduce aldehyde groups onto the lignin molecular backbone during lignin extraction. Furthermore, the TA stabilized lignin (TASL) is cross-linked with bisphenol A diglycidyl ether (BADGE) to enhance its alkali resistance performance and subsequently prepared into alkali-resistance BADGE- TASL hybrid LNPs (BADGE- TASL hy-LNPs) by anti-solvent precipitation and self-assembly. Because the presence of a large number of aldehyde groups in TASL compensates for the loss of phenolic hydroxyl groups caused by crosslinking reactions, a high loading of silver nanoparticles of 54.00% is obtained after redox reaction and adsorption in silver ammonia solution. When the BADGE-TASL hy-LNPs@Ag is used as an antibacterial agent, its inhibition efficiency reached ≈99%. Besides, the BADGE-TASL hy-LNPs@Ag can serve as a printing material for the preparation of conductive printing ink. Therefore, this study provides a strategy for lignin functionalization and application in printed electronics and antimicrobial fields.

A high-efficiency strategy for fruit preservation using green, natural raw materials

Straw is an abundant renewable biomass resource material. Lignin contained in straw is a unique natural aromatic compound in nature. At present, it is urgent to find ways to realize the higher value of natural lignin resources. In this study, alkali lignin was separated from rice straw by hydrothermal method in NaOH solution, which was prepared lignin nanoparticles by a simple green anti-solvent method. The obtained lignin nanoparticles had excellent anti-tyrosinase activity (IC50 = 0.329 mg mL−1) and anti-oxidation performance (IC50 = 0.0451 mg mL−1). Meanwhile, through the analysis of tyrosinase inhibition kinetics, it is concluded that the tyrosinase inhibition by lignin nanoparticles belongs to mixed inhibition. The affinity of lignin nanoparticles to the free enzyme is greater than that of enzyme and substrate complex. In addition, lignin nanoparticles were added to chitosan solution for compounding, then the composite films for fruit preservation were prepared by casting method. The experimental results show that the composite membrane can effectively extend the shelf life of fruits, which is expected to achieve a broader application in the field of fruit preservation and food packaging.

Active bio-nanocomposites from litchi seed starch, tamarind kernel xyloglucan, and lignin nanoparticles to improve the shelf-life of banana (Musa acuminata)

Valorization of agricultural byproducts to biodegradable packaging films aids in reducing plastic dependency and addressing plastic perils. Herein, starch (LSS) from litchi seeds and xyloglucan (XG) from tamarind kernels were recovered, and composite films were developed. The XG addition strengthened the weak polymer networks of LSS and improved rheological, molecular, morphological, mechanical, and water vapor barrier properties. The incorporation of lignin nanoparticles (LNPs) into the LSS-XG network further increased the tensile strength (14.83 MPa), elastic modulus (0.41 GPa), and reduced surface wettability (80.07°), and water vapor permeability (5.63 ± 0.38 × 10−7 g m−1s−1Pa−1). The phenolic hydroxyls of LNPs imparted strong UV-shielding and free radical scavenging abilities to films. These attributes aided in preserving the quality of coated banana fruits with minimal weight loss and color change. Overall, this research highlights the potential transformation of underutilized abundant byproducts into sustainable active bio-nanocomposites for food packaging and shelf-life extension of fruits.

Lignin Nanoparticles as pH-responsive Nanocarriers for Gastric-Irritant Oral Drug Aspirin.

Although lignin is one of the most naturally abundant biopolymers, the overall status of its utilization has long been subpar. The ability of Lignin to readily self-assemble into nanoparticles, along with its good biocompatibility and minimal toxicity, makes it a perfect agent for nanocarriers and drug delivery. Hence, in this study, we have attempted to examine lignin nanoparticles (LNPs) as an efficient pH-responsive nanocarrier for gastric-irritant oral NSAID, aspirin. Alkali lignin (AL) was extracted from rice straw via alkaline treatment, and the lignin nanoparticles were synthesized from lignin using the acid precipitation method. The average particle size was 201.37 ± 1.20 nm, and the synthesized LNPs exhibited a spherical shape and smooth outer surface along with high polydispersity (PDI= 0.284 ± 0.012). The LNPs showed moderate hemocompatibility during in vitro hemolysis studies. The nanoparticles presented nearly similar chemical structures to the AL from which they were developed, and the FT-IR absorption spectra confirmed the similarity of this chemical structure to the LNPs and AL. Aspirin was successfully loaded into the LNPs with a satisfactory drug loading value of 39.12 ± 1.50 and an excellent encapsulation efficiency value of 91.44 ± 0.59. Finally, the LNPs were capable of protecting the loaded drug at the acidic pH of the stomach (1.2) with just 29.20% release of the loaded aspirin after 10 h of observation in vitro. Contrarily, the LNPs were capable of rapidly releasing the aspirin at the basic pH of the intestine (7.4) with nearly 90% release of the loaded drug after 10 h observation in vitro. The basic pH of the intestine might lead to gradual dissociation of the LNPs followed by swift release of the loaded cargo. These findings substantiate that the LNPs carry the potential to be an apt and safe nanocarrier for oral drugs like aspirin as well as parenteral drugs, and LNPs can be utilized as an efficient alternative to enteric coating.

Simultaneous preparation of lignin-containing cellulose nanocrystals and lignin nanoparticles from wood sawdust by mixed organic acid hydrolysis

In the global search for sustainable and environmentally friendly materials, the efficient utilization of biomass resources has become a hot research topic. Due to the high specific surface area, nanocellulose crystals (CNCs) have attracted considerable attention. However, CNC preparation often requires the separation of lignin and hemicellulose, which wastes resources. In this study, lignin-containing cellulose nanocrystals (LCNCs) and lignin nanoparticles (LNPs) were prepared from p-toluenesulfonic acid (p-TsOH)/formic acid (FA) pretreated poplar wood in one-step. The process was performed in a mixed acid system with a mass ratio of p-TsOH, FA, and deionized water (DI) of 3:5:2, and mechanical stirring at 80 ºC for 3 h. Under these conditions, the lignin removal rate was about 70 %, and the LCNCs yield was more than 40 %. The p-TsOH is regained by vacuum distillation and recrystallization, and the recovery rate can reach 60 %. The prepared LCNCs were then carbonized and used as an electrode for electrochemical testing. The electrode obtained by carbonizing LCNC exhibits an areal capacitance of 156.4 F g−1 (0.5 A g−1). The study provided a new prospect for the efficient utilization of lignocellulosic nanomaterials.