In recent years, concerns about the harmful effects of synthetic UV filters on the environment have highlighted the need for natural sun blockers. Lignin, the most abundant aromatic renewable ...biopolymer on Earth, is a promising candidate for next-generation sunscreen due to its inherent UV absorbance and its green, biodegradable, and biocompatible properties. Lignin’s limitations, such as its dark color and poor dispersity, can be overcome by reducing particle size to the nanoscale, enhancing UV protection and formulation. In this study, 100–200 nm lignin nanoparticles (LNPs) were prepared from various biomass by-products (hardwood, softwood, and herbaceous material) using an eco-friendly anti-solvent precipitation method. Pure lignin macroparticles (LMPs) were extracted from beech, spruce, and wheat straw using an ethanol–organosolv treatment and compared with sulfur-rich kraft lignin (KL). Sunscreen lotions made from these LMPs and LNPs at various concentrations demonstrated novel UV-shielding properties based on biomass source and particle size. The results showed that transitioning from the macro- to nanoscale increased the sun protection factor (SPF) by at least 2.5 times, with the best results improving the SPF from 7.5 to 42 for wheat straw LMPs and LNPs at 5 wt%. This study underscores lignin’s potential in developing high-quality green sunscreens, aligning with green chemistry principles.
TMPRSS2-ERG junction oncogene is present in more than 50% of patients with prostate cancer and its expression is frequently associated with poor prognosis. Our aim is to achieve gene knockdown by ...siRNA TMPRSS2-ERG and then to assess the biological consequences of this inhibition. First, we designed siRNAs against the two TMPRSS2-ERG fusion variants (III and IV), most frequently identified in patients' biopsies. Two of the five siRNAs tested were found to efficiently inhibit mRNA of both TMPRSS2-ERG variants and to decrease ERG protein expression. Microarray analysis further confirmed ERG inhibition by both siRNAs TMPRSS2-ERG and revealed one common down-regulated gene, ADRA2A, involved in cell proliferation and migration. The siRNA against TMPRSS2-ERG fusion variant IV showed the highest anti-proliferative effects: Significantly decreased cell viability, increased cleaved caspase-3 and inhibited a cluster of anti-apoptotic proteins. To propose a concrete therapeutic approach, siRNA TMPRSS2-ERG IV was conjugated to squalene, which can self-organize as nanoparticles in water. The nanoparticles of siRNA TMPRSS2-ERG-squalene injected intravenously in SCID mice reduced growth of VCaP xenografted tumours, inhibited oncoprotein expression and partially restored differentiation (decrease in Ki67). In conclusion, this study offers a new prospect of treatment for prostate cancer based on siRNA-squalene nanoparticles targeting TMPRSS2-ERG junction oncogene.
This article presents new research on producing lignin nanoparticles (LNPs) using the antisolvent nanoprecipitation method. Acetone (90%) served as the lignin solvent and water (100%) as the ...antisolvent, using five types of lignins from various sources. Comprehensive characterization techniques, including NMR, GPC, FTIR, TEM, and DLS, were employed to assess both lignin and LNP properties. The antioxidant activity of the LNPs was evaluated as well. The results demonstrated the successful formation of spherical nanoparticles below 100 nm with initial lignin concentrations of 1 and 2%w/v. The study highlighted the crucial role of lignin purity in LNP formation and colloidal stability, noting that residual carbohydrates adversely affect efficiency. This method offers a straightforward, environmentally friendly approach using cost-effective solvents, applicable to diverse lignin sources. The innovation of this study lies in its demonstration of a cost-effective and eco-friendly method to produce stable, nanometric-sized spherical LNPs. These LNPs have significant potential as reinforcement materials due to their reinforcing capability, hydrophilicity, and UV absorption. This work underscores the importance of starting material purity for optimizing the process and achieving the desired nanometric dimensions, marking a pioneering advancement in lignin-based nanomaterials.
RET/PTC3 junction oncogene is typical of radiation-induced childhood papillary thyroid carcinoma (PTC) with a short latency period. Since, RET/PTC3 is only present in the tumour cells, thus ...represents an interesting target for specific therapy by small interfering RNA (siRNA). Our aim is to demonstrate in vitro and in vivo molecular and cellular effects of siRNA on RET/PTC3 knockdown for therapeutic application.First, we established a novel cell line stably expressing RET/PTC3 junction oncogene, named RP3 which was found tumorigenic in nude mice compared to NIH/3T3 mouse fibroblasts. Among four siRNAs and five concentrations tested against RET/PTC3, an efficient siRNA RET/PTC3 and an appropriate dose (50 nM) were selected which showed significant inhibition (p<0.001) of gene (RT-qPCR) and protein (Western blot) expressions. This siRNA was found efficient in RP3 cells (harbouring RET/PTC3) but non-efficient in BHP10-3 SCmice cell line (harbouring RET/PTC1) showing that a specific siRNA against fusion sequence is required to target the junction oncogene. In vitro siRNA RET/PTC3 showed significant (p<0.001) inhibitory effects on RP3 cell viability (MTT assay) and on invasion/migration (IncuCyte scratch test) with blockage of cell cycle at G0/G1 phase (flow cytometry) and induced apoptosis by caspase-3 and PARP1 cleavage (WB). After intravenous injection in nude mice, respective squalene (SQ) nanoparticles (NPs) of siRNA RET/PTC3 significantly (p<0.001) reduced RP3 tumour growth, oncogene and oncoprotein expressions, induced apoptosis and partially restored differentiation (decrease in Ki67). Hence, our findings highly support the use of siRNA RET/PTC3-SQ NPs as a new promising treatment for patients affected by PTC expressing RET/PTC3.
Tannin-furanic biobased foams, based on the co-reaction of bark-derived condensed tannins and thermoset furanic polymers, have low thermal conductivity, are self-extinguishing, and have high fire ...resistance, which allows their development for several industrial uses. One of their main drawbacks, however, is the absorption of water within the foam itself. Another problem is the rather friable surface, which is a definite drawback for some potential applications. In this work, these two problems are minimized or eliminated by introducing a component of oil-grafted tannin in the foam formulation. The incorporation of fatty chains markedly decreased foam friability and increased water repellency in the body of the foams. These properties and the compounds formed by fatty acids grafting onto the tannin flavonoids were extensively tested.
Two approaches to the synthesis of the title 6‐substituted 2(1H)‐pyridon‐3‐yl C‐2′‐deoxyribonucleosides have been pursued. A protected 6‐aminopyridine C‐nucleoside intermediate was converted into the ...N‐oxide followed by Ac2O‐mediated rearrangement and final deprotection to give 6‐acetylamino‐2‐oxo(1H)‐pyridin‐3‐yl deoxyribonucleoside. Due to the unusually high stability of the N‐acetyl group, the full deprotection was unsuccessful. In the second approach, 6‐chloro‐2‐pyridone was converted into phosphorodiamidate, which underwent ortho‐magnesiation and iodination to give the 3‐iododerivative. It was then used in a Heck coupling with a sugar glycal and the resulting product deprotected to give 6‐chloro‐2‐oxo(1H)‐pyridin‐3‐yl deoxyribonucleoside, which was either directly or after reprotection converted into 6‐methyl‐, 6‐amino‐, and 6‐unsubstituted pyridone C‐nucleosides. The final nucleosides were very unstable and easily epimerized and/or oxidized, which limits (but not excludes) their further use in chemical biology.
Long wanted and difficult to make 1‐deazapyrimidine C‐nucleosides: 6‐Substituted 2(1H)‐pyridon‐3‐yl C‐deoxyribonucleosides were prepared through a sequence consisting of ortho‐magnesiation/iodination, Heck coupling with glycal, reduction, reprotection, and cross‐coupling or hydrogenation of the key chloropyridine intermediate. The final compounds were relatively unstable.
In order to handle urgent energy and environmental issues, the development of a circular economy supported by lignocellulosic biorefineries is essential right now. In this respect, lignin should no ...longer be seen as a waste or byproduct but as a renewable and abundant resource. This is why research has recently focused on the development of lignin nanoparticles (LNPs) from kraft lignin (KL), opening up new value-added areas. However, to date, no study has focused on a top-down lignin-based approach over further produced LNP properties, i.e., the contribution of the initial raw biomass types (hardwood, softwood, and herbaceous material) and lignin macroparticle extraction. This top-down, lignin-based approach, considering lignin valorization as the primary resource from the design phase, offers insights into the chemical lignin structure and functional group interactions in LNP formation. To this end, a new water steam explosion pretreatment was carried out upstream of an ethanol-organosolv treatment in order to rapidly extract pure lignin, which is then reduced to nanosize by antisolvent precipitation. We show that the initial raw biomass type such as lignin extraction (organosolv lignin compared to KL) makes a significant difference to particle size (50–250 nm), aggregation, and morphology in aqueous suspensions. The tailored LNPs formed by this eco-friendly, simple, fast, and high-yield process (7–15 wt % LNPs of initial biomass byproducts), which can be upscaled for industrial purposes, are stable over 90 days’ storage and have better properties than those of kraft LNPs. LNPs resulting from this work therefore have great potential for high value-added applications such as cosmetics and medicine.
Herein, we report a multistep synthesis of novel (meth)acrylate monomers based on gallic acid (GA), a biosourced phenolic acid. The objective of this work was to obtain bio-based polymers exhibiting ...antioxidant properties provided by monomers derived from gallic acid. The phenolic groups of GA, which are responsible for antioxidant properties, need to be protected for two reasons. On the one hand, functionalization to transform GA into polymerizable monomers must not take place at the phenolic groups because they must remain free to maintain the maximum antioxidant activity in the final polymers. On the other hand, their protection is necessary to prevent radical scavenging during the radical polymerization. After synthesis of such monomers, protected GA-based polymers were thus produced through a photo-mediated RAFT polymerization at room temperature by evaluating two trithiocarbonate-type chain transfer agents (CTAs). The kinetics and molecular weight distributions were studied depending on the monomers and the CTAs. Protected polymers were then deprotected to afford polymeric chains carrying one free gallic acid moiety on each monomer unit. The antioxidant activity of these free GA-based polymers was demonstrated either through the DPPH free radical scavenging property or through the inhibition of methyl linoleate oxidation.
•Extractives from the bark of Indonesian tree species were investigated.•Mahoni and Acacia were the most promising species due to their high extractives contents.•Fatty acids, di- and triterpenes ...were the main compounds identified by GC–MS.•Acacia and sengon barks contain some condensed tannins.•Chemical composition explains antioxydative and antifungal properties of extracts.
Barks are available as waste material and by-product of wood industry. They have been reported to contain interesting molecules and show some bioactivity such as antioxidant and antifungal. This study aimed at evaluating the amounts of extractives in Acacia mangium (acacia), Paraserianthes falcataria (sengon) and Swietenia mahagoni (mahoni) barks, to evaluate their extractive contents and the presence of potential valuable molecules. The extraction method used soxhlet with four different solvents. Antioxidant activity assays were carried out using methyl linoleate and 2,2-diphenyl-1-picrilhidrazyl (DPPH) and the antifungal activity was determinate by fungal growth inhibitions assays. 5.3%–18.5% extraction yields were obtained. All acetone and toluene ethanol extracts show high antioxidant activity by DPPH. The highest antioxidant value obtained by DPPH was obtained for mahoni bark acetone extract with 3.9mg/L of EC50, followed by mahoni bark toluene ethanol 6.8mg/L, acacia bark acetone 7mg/L, and acacia bark toluene ethanol extract 7.4mg/L. Sengon bark extracts had the greatest antifungal activity inhibition. The greatest antioxidant and antifungal activity were obtained with phenolic compounds which were contained in the extracts.
Key message
Teak (
Tectona grandis
L.f.) is one of the most important tropical hardwood tree species, which is widely planted in Indonesia. Wood properties are strongly influenced by forest ...management conditioning further utilization of wood.
Context
In Indonesia, teak wood has been supplied from the state forests (Perhutani) for long rotation teak and from community teak plantations for short rotation teak. Short rotation teak has been harvested at 7–10 years and long rotation teak at 40–60 years.
Aims
This paper discusses the characterization of technical properties of short and long rotation teak wood based on the chemical, anatomical, physical, and mechanical properties.
Methods
The properties of short rotation and long rotation teak woods were characterized by measuring their density, extractive contents, chemical composition, swelling, wettability, water sorption isotherm, decay resistance, anatomical properties, bending strength (modulus of rupture (MOR), modulus of elasticity (MOE)), and hardness.
Results
The results indicate that short rotation teak was not particularly different in swelling, MOE and MOR, and Brinell hardness compared to long rotation teak, although it was less dense and less durable due to lower heartwood and extractive contents. Therefore, careful attention should be given to the use of short rotation teak in some wood-processing technologies.
Conclusion
Lower wood density and durability of the short rotation compared to the long rotation teak will restrict its utilization to some extent for both indoor and outdoor applications. Fast-growing teak from community cannot be used as usual heartwood teak from Perhutani because of the very low proportion of useful heartwood in the stem.
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