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Conventional tumor therapeutic modalities, such as radiotherapy, chemotherapy, and surgery, involve low tumor inhibition efficiency, non-targeted drug delivery, and side effects. The development of novel and practical nano-drug delivery systems (DDSs) for targeted tumor therapy has become particularly important. Among various bioactive nanoparticles, chitosan is considered a suitable candidate for drug delivery due to its non-toxicity, good biocompatibility, and biodegradability. The amino and hydroxyl groups of chitosan endow it with the diverse function of chemical modification, thereby improving its physical and biological properties to meet the requirements of advanced biomedical applications. Therefore, it is necessary to review the property and applications of chitosan-based materials in biomedicine. In this review, the characteristics of chitosan related to its applications are first introduced, and then the preparation and modification of chitosan-based nanoparticles, including the function tailoring of chitosan-modified nanoparticles, are demonstrated and discussed. Finally, the opportunities and challenges of chitosan-based nanomaterials in this emerging field are proposed from the perspective of the rational and systematic design for the biomedicine field.

Lignin is the only renewable aromatic material in nature and contains a large number of oxygen-containing functional groups. High-value and green utilization of "lignin-to-chemicals" can be realized via using lignin to produce fine chemicals such as phenols and carboxylic acids, which can not only reduce the waste of lignin in the process of lignocellulosic biomass treatment, but gradually make the substitution of traditional fossil fuels come true. The hydrogenolysis process under catalysis of metal catalyst has high product selectivity and less impurity, which is suitable for the production of same type or single fine chemicals. Hydrogenolysis of lignin via metal catalysts to produce lignin oil, and further modification of functional groups (e.g. methoxyl, alkyl and hydroxyl group) of depolymerized monomers in the bio-oil to yeild phenols and terephthalic acid are reviewed, and catalytic mechanisms are briefly summarized in this paper. Finally, the problems of lignin catalytic conversion existing currently are investigated, and the future development of this field is also prospected.

Four polyaniline-tea saponin (PTS) nanocomposites were prepared by an in-situ polymerization with tea saponin (TS) as a biosurfactant, and they were used to remove organic dyes from aqueous solution. The PTS nanocomposites were characterized by using field emission scanning electron microscopy, the Fourier transform infrared spectroscopy, the Ultraviolet-visible spectroscopy, and the thermogravimetric analysis. The adsorption performances of the PTS nanocomposites for organic dyes were studied by a static adsorption method. The experimental results reveal that adsorption capacities of the PTS nanocomposites are higher than that of pure polyaniline. Especially, the PTS nanocomposites exhibit excellent adsorption performances for anionic dyes because of the electrostatic interaction between the positively charged nitrogen atoms on the PTS chains and the negatively charged sulfonate ions in the anionic dyes. According to the adsorption kinetics and thermodynamics results, the adsorption processes of PTS20 for CR and AB74 follow well with the pseudo second-order and Langmuir isotherm models. It is indicated that TS should be very useful in the preparation of PTS nanocomposite and in removal of toxic dyes from waste water.

As a kind of lignocellulosic biomass, Pennisetum sinense (P. sinense) is commonly used as animal feed, fertilizer or papermaking raw materials. Based on the high carbon content and renewability of P. sinense, we explored the possibility and feasibility of using it as catalyst matrix. The catalyst was produced by sulfonation of char obtained from the carbonization of P. sinense at 550 °C. The structure of the catalyst was characterized by SEM, BET, XRD, FT-IR, XPS and TGA, and its catalytic performance for the hydrolysis of cellulose was investigated in detail. The highest acidity of the catalyst was 3.79 mmol/g and the maximum glucose yield of 59.92% was achieved under optimized conditions. The catalyst also showed a promising reusability. The glucose yield was 53.01% after 5 cycles and as high as 55.92% when using the regenerated catalyst.

Cassava residue was liquefied by using ethylene glycol (EG), ethylene carbonate, propylene carbonate and polyethylene glycol (molecular weight: 400 g/mol) as the liquefaction reagent respectively at the temperature of 130–170 °C with sulfuric acid as the catalyst. The influences of liquefaction parameters, such as the type of liquefaction reagents, mass ratio of EG/cassava residue, liquefaction temperature and time on the properties of the products were discussed. The optimum liquefaction conditions were obtained when the mass ratio of EG/cassava residue was 6:1 (w/w), the liquefaction temperature was 150 °C, the liquefaction time was 3 h and the mass fraction of concentrated sulfuric acid/EG was 2.5wt%. The hydroxyl numbers and residue content of the liquefied products at optimal conditions were 1 137 mgKOH/g and 0.43%, respectively. FT-IR spectrum showed that the liquefaction product of cassava residue was polyether polyol and could be used to prepare polyurethane material or alkyd resins.

As a kind of biomass that exists widely in plants, lignin shows much diversity as a functional material. In order to improve the adsorption ability, lignin was chemically modified by 5-sulfosalicylic acid and then used to adsorb methylene blue (MB) and Pb2+ from aqueous solutions. The results showed that the 5-sulfosalicylic acid modified lignin exhibited a high adsorption ability for dyes or heavy metals. The maximum adsorption capacity of the adsorbent approached 83.2 mg/g for MB and 39.3 mg/g for Pb2+ with the adsorbent dosage of 5 g/L at pH 5.85 or 5.35 (corresponding to MB or Pb2+, respectively), initial adsorbate concentration of 200 mg/L, temperature of 318 K and contact time of 12 h. The adsorption kinetics and isotherm studies indicated that both the adsorption of MB and Pb2+ onto SSAL followed the pseudo-second-order model and Langmuir isotherm model. It means that the adsorption process fits the model of mono-layer adsorption and it was mainly chemical process and accompanied with surface adsorption. The proposed SSAL is low-cost, eco-friendly and highly efficient therefore a promising material for adsorptive removal of MB and Pb2+ from wastewater.

Carbon quantum dots (CQDs), a new type of fluorescence carbon nanomaterials with particle size varied from 2 to 10 nm, have attracted much attention due to their strong multi-color luminescence properties, unprecedented biocompatibility, excellent aqueous dispersibility and easy preparation from a wide range of carbon materials. These multiple attributes help CQDs possess a broad range of prospective applications in numerous fields, especially for bio-imaging, drug delivery, chemical probe and photon therapy because of their advantages of low cytotoxicity and good biocompatibility. Therefore, it is necessary to recap the synthesis and application of CQDs-based materials in the field of biomedicine. The methods for the synthesis of CQDs are introduced firstly, and then different performance of CQDs related to their applications are demonstrated and discussed, including the function tailoring of CQDs. Finally, future opportunities and challenges of CQDs-based materials in this burgeoning field are proposed from the perspective of the rational design of systematic CQDs-based materials toward the biomedicine field.

Four compounds (TM-1∼4) based on N-(4-trifluoromethylphenyl)phenothiazine-S,S-dioxide and N-[3,5-bis(trifluoromethyl)phenyl]phenothiazine-S,S-dioxide are synthesized by Buchwald-Hartwig cross coupling reaction. The effect of different substituents in acceptors on the electronic, photophysical and electrochemical properties are studied by UV–Vis, fluorescence spectroscopy, cyclic voltammetry curves and theoretical calculations. The energy gaps (ΔEST) between singlet excited states (S1) and triplet excited states (T1) of these compounds decrease by addition of one para-substituted CF3 or two meta-substituted CF3 on N-phenyl in order to enhance the electron-withdrawing capability of the acceptors. Small ΔEST of these compounds range from 0.09 eV to 0.18 eV. TM-2∼4 exhibit thermally activated delayed fluorescence (TADF) characteristics with short delayed fluorescence lifetimes (τd) within 0.69-1.16 μs. TM-3 emits blue light with an emission wavelength of 475 nm.

Cobalt nanoparticles (CoNPs) have been widely used in industry given their physical, chemical and magnetic properties; however, CoNPs may cause neurological symptoms and diseases in human, yet their mechanisms of toxicity remain unknown. Here, we used male Wistar rats to investigate differences in the toxic effects associated with CoNPs and CoCl2. Upon exposure to CoCl2, and 96 nm or 123 nm CoNPs at the same concentration, the Co2+ content in CoCl2 group was significantly higher than that in either the CoNPs groups in brain tissues and blood, but lower in liver. Significant neural damage was observed in both hippocampus and cortex of the temporal lobe. Increase malondialdehyde (MDA) content and CASPASE 9 protein level were associated both with CoCl2 and CoNPs treatments, consistent with lipid perioxidation and apoptosis. Heme oxygenase-1 and (NF-E2) p45-related factor-2 protein levels were elevated in response to 96 nm CoNPs exposure. In PC12 cells, NRF2 downregulation led to reduced cell viability and increased apoptotic rate. In conclusion, both CoNPs and CoCl2 cause adverse neural effects, with nanoparticles showing greater neurotoxic potency. In addition, NRF2 protects neural cells from damage induced by CoCl2 and CoNPs by activating downstream antioxidant responses.

Hardwood residue (HR), a byproduct of paper industry, was liquefied by using polyethylene glycol 400 (PEG400) and ethylene carbonate (EC) as the liquefaction solvents, and concentrated sulfuric acid as the catalyst to produce bio-polyols (HRLP), which were used to synthesize polyurethane (PU) foams. The effects of conditions on the properties of HRLP and modified PU foams were investigated and the mechanism of biomass liquefaction was discussed. The optimum conditions of liquefaction were obtained as follows: reaction temperature of 160 °C, reaction time of 60 min, ratio of PEG400/EC of 8:2 (w/w), and ratio of liquid/solid of 5:1 (w/w). The characterization of HRLP modified PU foams suggested that HRLP could partially replace the petroleum polyols to synthesize PU foams. With the increase of the replacement percentage of HRLP, the apparent density and compressive strength of the foams increased firstly, and then decreased. Meanwhile, the thermal stability was improved slightly.

Four novel compounds (1–4) were synthesized using 2-phenyl-4H-1-benzopyran-4-one (flavone) moiety as an acceptor and phenoxazine, phenothiazine, 9,9-dimethyl-9,10-dihydroacridine, diphenylamine as donors. Their photophysical properties were studied with spectroscopic and theoretical methods. The results show that 1 and 2 exhibit good aggregation-induced emission (AIE) properties in tetrahydrofuran (THF)/water mixtures, whose maximum photoluminescence (PL) intensities are 156- and 187-fold higher than those in pure THF solutions, and can reach 256- and 506-fold higher than those in the mixtures at water fractions of 50%, respectively. 3 displays similar PL property except for obvious emission in pure THF solution. However, PL intensity of 4 decreases with an increase in water fraction, and then is enhanced with further increase in water fraction. Moreover, 4 shows high quantum yields both in toluene solution (0.61) and in solid state (0.83). It exhibits a positive solvatochromism. In addition, 2 possesses mechanofluorochromic transition from sky blue to yellow after grinding. It can also be applied in live-cell imaging.

Citric acid modified cellulose waste (CMCW) was prepared via esterification and used as a low-cost biosorbent for the removal of methylene blue (MB) from aqueous solutions. The effects of biosorbent concentration, initial pH of MB solution, biosorption temperature, contact time, and initial MB concentration on the biosorption of MB were investigated using batch biosorption technique under static conditions. The experimental results showed that CMCW exhibited excellent biosorption characteristics for MB. The maximum biosorption capacity of MB was up to 214.5 mg/g at an adsorption temperature of 293 K. The removal rate of MB onto CMCW reached the maximum at pH>4 and the biosorption reached an equilibrium at about 50 min. The kinetic data can be described well with the pseudo-second-order model and the isotherm data was found to fit the Langmuir isotherm with a monolayer adsorption capacity of 211.42 mg/g. The biosorption appears to be controlled by chemisorption and may be involved in surface adsorption and pore diffusion during the whole biosorption process.

Citric acid modified mixed hardwoods powder (CMH) was prepared as a biosorbent to remove copper ions and methylene blue (MB) from aqueous solution by batch techniques. FT-IR and XRD were used to characterize the biosorbent. The effects of initial pH value, biosorption temperature, contact time, and initial adsorbate concentration on the biosorption capacities and adsorptivity of Cu2+ and MB onto CMH were investigated. The results showed that CMH exhibited excellent biosorption characteristics for Cu2+ and MB. The maximal biosorption capacity of Cu2+ and MB onto CMH was 165.0 and 237.4 mg/g at 20 °C, respectively. The biosorption kinetics studies indicated that Cu2+ and MB biosorption followed the pseudo-second-order model. The biosorption may be controlled by external intraparticle diffusion mass transfer during the whole biosorption process. Furthermore, the biosorption-equilibrium can be well described by Langmuir and Freundlich isotherm models.

Novel woodceramics were successfully fabricated by enzymatic hydrolysis lignin (EHL) modified phenol-formaldehyde resin and woodpowders. The microstructure of woodceramics was investigated by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of EHL-modified PF resin on the properties of woodceramics, such as the weight loss ratio, volume shrinkage ratio, open porosity, bending strength and compressive strength, were studied. The experimental results showed that EHL modified woodceramics had a uniform porous structure. EHL-modified PF resin played an important role in the properties of woodceramics. With the increase of EHL-modified PF resin content, the open porosity, weight loss ratio and volume shrinkage ratio of woodceramics increased, but the bending strength and compressive strength decreased.

Enzymatic hydrolysis lignin (EHL), isolated from the enzymatic hydrolysis residues of the biomass, was liquefied using the mixed solvents of polyethyleneglycol (PEG) and glycerol at the temperature of 130-170°C with sulfuric acid as a catalyst. The influences of liquefaction parameters, such as the molecular weight of PEG, mass ratio of sulfuric acid to EHL, liquefaction temperature and time, and mass ratio of liquid (liquefying cosolvent) to solid (EHL) on the residue content and hydroxyl number were discussed. The FT-IR spectrum result showed that the liquefaction product of EHL was polyether polyol. The hydroxyl number of the liquefaction product was 80-120 mgKOH/g higher than that of PEG.

Emulsified asphalts are popular at recent years for saving energy to melt solid asphalt. Emulsifier is very important for emulsification of asphalt. Enzymatic hydrolysis lignin modified amine (EHLA) was synthesized by Mannich reaction of enzymatic hydrolysis lignin (EHL) with formaldehyde and triethylene tetramine (TETA). The structures of the product was analyzed by FT-IR, and the influence of process parameters such as the molar ratio of formaldehyde to TETA, the reaction temperature and time were discussed. According to the results, the optimized technological conditions were as follows: the reaction temperature was 80 °C, the molar ratio of formaldehyde to TETA was 1.6∶1, reaction time was 3 h, and the weight of lignin was 25 g. The result of emulsification shows that EHLA could be an effective and slow set cationic asphalt emulsifier.

Phenol-formaldehyde (PF) adhesives modified with enzymatic hydrolysis lignin (EHL) were synthesized by a one-step process. The phenol component of the PF adhesives was partially substituted by EHL extracted from the residues of cornstalks used to produce bio-ethanol. The EHL-PF adhesives were used to prepare plywoods by hot-pressing. The pH value, viscosity, solid content, free phenol content, free formaldehyde content and brominable substance content of EHL-PF resins were investigated. The bonding strengths of the plywoods were determined, and the influences of the replacement percentage of phenol by EHL (a) and the NaOH content (b) on the properties of the adhesives were investigated. The results showed that the performance of the modified adhesives and the plywoods glued with them almost met the Chinese National Standard (GB/T 14732-2006) for first grade plywood when 20 wt% of the phenol was replaced by EHL.