Plant flavonoids: Classification, distribution, biosynthesis, and antioxidant activity.

Bacterial cellulose (BC), with non-toxicity, high purity, and biocompatibility, has been considered as a versatile candidate for various biomedical applications. Recently, the fabrication of BC-bas...

Bacterial Cellulose-Based Composite Scaffolds for Biomedical Applications: A Review

Carbon and graphene quantum dots are prepared using top-down and bottom-up methods. Sustainable synthesis of quantum dots has several advantages such as the use of low-cost and non-toxic raw materials, simple operations, expeditious reactions, renewable resources and straightforward post-processing steps. These nanomaterials are promising for clinical and biomedical sciences, especially in bioimaging, diagnosis, bioanalytical assays and biosensors. Here we review green methods for the fabrication of quantum dots, and biomedical and biotechnological applications.

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Green synthesis, biomedical and biotechnological applications of carbon and graphene quantum dots. A review

Lignin–carbohydrate complexes (LCCs) have shown antioxidant ability to scavenge the individual free radicals in vitro, while little work has been carried out to show if the LCCs can efficiently scavenge the intracellular and endogenous reactive oxygen species (ROS), which are the multiple radicals derived from the reduction of molecular oxygen during the metabolism process. In this work, carbohydrate-rich LCCs from bamboo (LCCs–B-B) and poplar (LCCs–B-P) were isolated according to the classical method, and their antioxidant activities were evaluated by scavenging intracellular ROS in RAW 264.7 cells in vitro and endogenous ROS in zebrafish in vivo. Results from composition analysis show that both LCC preparations possess similar contents of carbohydrate (52.2% and 51.2%) and lignin (44.1% and 47.8%). However, NMR analysis revealed that the LCCs–B-B contain 16.1/100C9 LCCs linkages, higher than that in LCCs–B-P (12.3/100C9). Antioxidant assays indicated that LCCs–B-B exhibited better antioxidant activities...

Characterization and Application of Lignin–Carbohydrate Complexes from Lignocellulosic Materials as Antioxidants for Scavenging In Vitro and In Vivo Reactive Oxygen Species

As an important member of fluorescence nanoparticles, carbon dots (CDs) not only possess exceptional chemical properties, including excellent biocompatibility, low toxicity and chemical inertness, but also exhibit promising optical properties, such as broad excitation spectra, tunable emission spectra and high photostability, thus attracting tremendous attention. Over the past decade, applications of CDs in numerous fields have been intensively investigated, ranging from biomedical analysis to optoelectronics and energy. Among these cutting-edge applications, this review article mainly outlines recent advances in the field of CD-based bioimaging and summarizes achievements in two broad categories: in vitro imaging in terms of the approaches to deliver CD-based probes into different types of cells and vital cell organelles, as well as in vivo applications that focus on distribution and uptake of CDs in mice and zebrafish, imaging-guided drug delivery and tumor therapeutics. Furthermore, the potential superiority, challenges and future directions of CDs for imaging are also presented. The purpose of this review is to highlight the importance of CD-based bioimaging and to boost its development in diverse research fields ranging from materials science to biomedicine.

Recent advances in carbon dots for bioimaging applications

The carbon quantum dot (CQD), a fluorescent carbon nanoparticle, has attracted considerable interest due to its photoluminescent property and promising applications in cell imaging and bioimaging. In this work, biocompatible, photostable, and sustainably sourced CQDs were synthesized from byproducts derived from a biorefinery process using one-pot hydrothermal treatment. The main components of byproducts were the degradation products (autohydrolyzate) of biomass pretreated by autohydrolysis. The as-synthesized CQDs had a size distribution from 2.0–6.0 nm and had high percentage of sp2 and sp3 carbon groups. The CQDs showed blue-green fluorescence with a quantum yield of ~13%, and the fluorescence behaviors were found to be stable with strong resistance to photobleaching and temperature change. In addition, it is found that the as-synthesized CQDs could be used for imaging of cells and tumors, which show potential applications in bioimaging and related fields such as phototherapy and imaging.

https://www.mdpi.com/2079-4991/9/3/387/pdf

Synthesis of Carbon Quantum Dot Nanoparticles Derived from Byproducts in Bio-Refinery Process for Cell Imaging and In Vivo Bioimaging

The cellular components of historical or archaeological wooden objects can be degraded by fungi or bacteria during ageing. However, understanding the chemical changes of the molecular and structural features of lignin during ageing and degradation remains inadequate. To improve the state of knowledge in this field of study, lignins from archaeological fir wood aged in tombs, which range in years from ∼200 BC–1600 AD, have been thoroughly analyzed. Results from the visual fluorescence images showed that the lignin in certain regions of the xylem cell wall underwent more degradation compared to the control sample (healthy fir wood). Chemical analysis and structural analysis, using nuclear magnetic resonance, of isolated lignins from each wood sample indicated lignin depolymerization via loss of native substructures, most notably a decrease in β-O-4 linkages over time. Relative to the control sample, it is found that ageing mostly induces depolymerization, but certain results hint that lignin repolymerization might take place at extended ageing times. Overall, the results obtained can help guide efforts towards taking better care of archaeological woods uncovered across the world.

Revealing the effects of centuries of ageing on the chemical structural features of lignin in archaeological fir woods

Green solvent pretreatment for enhanced production of sugars and antioxidative lignin from poplar

Promoting enzymatic hydrolysis of aggregated bamboo crystalline cellulose by fast microwave-assisted dicarboxylic acid deep eutectic solvents pretreatments.

Synergistic effects of hydrothermal and deep eutectic solvent pretreatment on co-production of xylo-oligosaccharides and enzymatic hydrolysis of poplar

Yan Su

Papers

Synthesis of Carbon Quantum Dot Nanoparticles Derived from Byproducts in Bio-Refinery Process for Cell Imaging and In Vivo Bioimaging

Revealing the effects of centuries of ageing on the chemical structural features of lignin in archaeological fir woods

Green solvent pretreatment for enhanced production of sugars and antioxidative lignin from poplar

Promoting enzymatic hydrolysis of aggregated bamboo crystalline cellulose by fast microwave-assisted dicarboxylic acid deep eutectic solvents pretreatments.

Synergistic effects of hydrothermal and deep eutectic solvent pretreatment on co-production of xylo-oligosaccharides and enzymatic hydrolysis of poplar