Advances in the Design of Functional Cellulose Based Nanopesticide Delivery Systems.

The advancement of science and technology, coupled with the growing environmental consciousness among individuals, has led to a shift in pesticide development from traditional methods characterized by inefficiency and misuse toward a more sustainable and eco-friendly approach. Cellulose, as the most abundant natural renewable resource, has opened up a new avenue in the field of biobased drug carriers by developing cellulose-based drug delivery systems. These systems offer unique advantages in terms of deposition rate enhancement, modification facilitation, and environmental impact reduction when designing nanopesticides. Consequently, their application in the field of nanoscale pesticides has gained widespread recognition. The present study provides a comprehensive review of cellulose modification methods, carrier types for cellulose-based nanopesticides delivery systems (CPDS), and various stimulus-response factors influencing pesticide release. Additionally, the main challenges in the design and application of CPDS are summarized, highlighting the immense potential of cellulose-based materials in the field of nanopesticides.

Monodispersed Renewable Particles by Cascade and Density Gradient Size Fractionation to Advance Lignin Nanotechnologies.

Control over particle size and shape heterogeneity is highly relevant to the design of photonic coatings and supracolloidal assemblies. Most developments in the area have relied on mineral and petroleum-derived polymers that achieve well-defined chemical and dimensional characteristics. Unfortunately, it is challenging to attain such control when considering renewable nanoparticles. Herein, a pathway toward selectable biobased particle size and physicochemical profiles is proposed. Specifically, lignin is fractionated, a widely available heterogeneous polymer that can be dissolved in aqueous solution, to obtain a variety of monodispersed particle fractions. A two-stage cascade and density gradient centrifugation that relieves the need for solvent pre-extraction or other pretreatments but achieves particle bins of uniform size (~60 to 860 nm and polydispersity, PDI<0.06, dynamic light scattering) along with characteristic surface chemical features is introduced. It is found that the properties and associated colloidal behavior of the particles are suitably classified in distinctive size populations, namely, i) nanoscale (50-100 nm), ii) photonic (100-300 nm) and iii) near-micron (300-1000 nm). The strong correlation that exists between size and physicochemical characteristics (molar mass, surface charge, bonding and functional groups, among others) is introduced as a powerful pathway to identify nanotechnological uses that benefit from the functionality and cost-effectiveness of biogenic particles.

Targeting CDK4/6 in glioblastoma via in situ injection of a cellulose-based hydrogel.

Despite aggressive treatments, including surgery, chemotherapy and radiotherapy, the prognosis of glioblastoma (GBM) remains poor, and tumor recurrence is inevitable. The FDA-approved CDK4/6 inhibitor palbociclib (PB) showed interesting anti-GBM effects, but its brain penetration is limited by the blood-brain barrier. The aim of this project is to find whether the cellulose-based hydrogel via in situ injection could provide an alternative route to PB brain delivery and generate sufficient drug exposure in orthotopic GBM. In brief, PB was encapsulated in a cellulose nanocrystal network structure crosslinked by polydopamine via divalent Cu2+ and hexadecylamine. The formed hydrogel (PB@PH/Cu-CNCs) exhibited sustained drug retention and acid-responsive network de-polymerization for controlled release in vivo. Specifically, the released Cu2+ catalyzed a Fenton-like reaction to generate reactive oxygen species (ROS), which was further enhanced by PB, and consequently, irreversible senescence and apoptosis were induced in GBM cells. Finally, PB@PH/Cu-CNCs demonstrated a more potent anti-GBM effect than those treated with free PB or PH/Cu-CNCs (drug-free hydrogel) in cultured cells or in an orthotopic glioma model. These results prove that the injection of the PB-loaded hydrogel in situ is an effective strategy to deliver the CDK4/6 inhibitor into the brain and its anti-GBM effect can be further enhanced by combining Cu2+-mediated Fenton-like reaction.

Liquid metal and Mxene enable self-healing soft electronics based on double networks of bacterial cellulose hydrogels.

Liquid metal (LM) nanodroplets and MXene nanosheets are integrated with sulfonated bacterial nanocellulose (BNC) and acrylic acid (AA). Upon fast sonication, AA polymerization leads to a crosslinked composite hydrogel in which BNC exfoliates Mxene, forming organized conductive pathways. Soft conducting properties are achieved in the presence of colloidally stable core-shell LM nanodroplets. Due to the unique gelation mechanism and the effect of Mxene, the hydrogels spontaneously undergo surface wrinkling, which improves their electrical sensitivity (GF = 8.09). The hydrogels are further shown to display interfacial adhesion to a variety of surfaces, ultra-elasticity (tailorable elongation, from 1000 % to 3200 %), indentation resistance and self-healing capabilities. Such properties are demonstrated in wearable, force mapping, multi-sensing and patternable electroluminescence devices.

Nanocellulose-based drug carriers: Functional design, controllable synthesis, and therapeutic applications.

With rising living standards and environmental awareness, materials-oriented chemical engineering has increasingly transitioned from traditional rough models to more resource-saving and eco-friendly models, providing an avenue for bio-based materials in the drug carrier field. Because of its excellent physical and chemical properties, including high specific surface area, abundant accessible hydroxyl groups, biocompatibility, and degradability, nanocellulose (NC) is an emerging bio-based material that has been widely exploited as biomedical materials. The modification techniques of NC, as well as advancements in the design and applications of drug carriers, were primarily discussed in this study. First, the NC modification methods are described; second, the applications of NC and its derivatives as drug carriers are summarized, focusing on NC-based carrier models, types of loaded therapeutic agents, and controlled release stimulators; and finally, the current challenges of NC in the drug carrier field and the directions of future research are also discussed.

Toxic reactive oxygen species enhanced chemodynamic therapy by copper metal-nanocellulose based nanocatalysts.

When compared with traditional petroleum-based materials, bio-based materials show greater application potential in the field of biomedicine owing to the good biocompatibility, in specifical, the application of natural macromolecular polymers in chemotherapeutics has become a hot topic in anticancer treatment. In this study, cellulose nanocrystals (CNCs) were selected as carriers, and Au nanoparticles (NPs) were directly conjugated on their surface, with the highly reactive Cu2+ ions serving as an ion-ligand bridge, to construct a multifunctional nanocatalyst. These findings suggest that the nanosystem delivers a large amount of highly reactive Cu2+ ions (3.75 wt%) and DOX (7.71 wt%) by the surface loading of cellulose nanocrystals, which greatly improves ROS yield and promotes the application of the Fenton reaction system in cancer therapy.

A biocompatible and pH-responsive nanohydrogel based on cellulose nanocrystal for enhanced toxic reactive oxygen species generation.

Traditional therapeutic regimens are currently far from satisfactory, and the integration of biocompatible carbohydrate polymers and nanotechnologies with conventional therapeutics has become a focus of research in cancer therapy. Herein, A novel biocompatible and pH-responsive nanohydrogel composed of two functional polymeric chains was developed from cellulose nanocrystals (CNCs) and 5-aminolevulinic acid (ALA), or dopamine (DPA). The biological molecules PDA and ALA were respectively conjugated to CNC through the coordination of iron ions to form two functional polymeric chains (PDA/Fe@CNC and ALA/Fe@CNC). The PDA/Fe@CNC chain increased the adhesion of the nanohydrogels to cells, while the ALA/Fe@CNC chain significantly increased reactive oxygen species (ROS) production. Furthermore, PTX molecules loaded into the nanohydrogels combined with ROS to efficiently kill tumor cells. The nanohydrogels displayed excellent cell affinity, high ROS yield (8.0-fold greater than that in control), and strong cytotoxicity (2.7 % of cell viability). The present study highlights the great potential of biocompatible natural polysaccharide-based materials for biomedical applications, and provides a new strategy for reducing the toxicity and side effects associated with traditional chemotherapy, demonstrating a novel antitumor treatment paradigm with high-efficiency but with only minor side effects.

Dendritic Mesoporous Organosilica Nanoparticles: A pH-Triggered Autocatalytic Fenton Reaction System with Self-supplied H2O2 for Generation of High Levels of Reactive Oxygen Species.

Dendritic mesoporous silica nanoparticles represent a new biomedical application platform due to their special central radial pore structure for the loading of drugs and functional modification. Herein, we report functionalized dendritic mesoporous organosilica nanoparticles (DMONs), a pH-triggered Fenton reaction generator (TA/Fe@GOD@DMONs), incorporating natural glucose oxidase (GOD) in the DMONs with tannic acid (TA) grafted using Fe3+ on the surface, that have been designed and constructed for efficient tumor ablation with self-supplied H2O2 and accelerated conversion of Fe3+/Fe2+ by TA. In view of the deficiency of endogenous H2O2, the self-supply through the TA/Fe@GOD@DMONs platform represented a high-yielding source of peroxygen. Furthermore, the production of Fe2+ induced by TA greatly improved the efficiency of the Fenton reaction resulting in significant tumor inhibition. This new design represents as novel paradigm for the development of autocatalytic Fenton nanosystems for effective treatment of tumors.

Low-Temperature Trigger Nitric Oxide Nanogenerators for Enhanced Mild Photothermal Therapy.

Surmounting the restriction issues of nitric oxide (NO) delivery to realize their precious on-demand release is highly beneficial for the widespread deployment of gas therapy for application in biomedicine. Herein, by employing core-shell structure Au@SiO2 nanomaterials with high photothermal performance, a novel strategy was proposed by integrating photothermal conversion nanomaterials and heat-triggered NO donors (RSNO) into a nanoplatform, which achieved photothermal therapy (PTT)-enhanced NO gas therapy under near-infrared (NIR) radiation. Specifically, 2-phenylethynesulfonamide (PES), an inhibitor of heat shock protein 70 (HSP-70), was loaded into the NO nanogenerators to realize effective low-temperature (∼45 °C) PTT. The obtained results showed that the near-infrared radiation (NIR) mediated mild PTT and gas therapy by releasing NO showed a substantially improved synergistic effect based on in vitro and in vivo results in breast cancer (MCF-7) models. Our study points out a strategy to realize mild photothermal therapy by inhibiting the expression of HSP-70 and simultaneously providing an avenue to achieve controllable release of NO. More important, this research highlights the great potential of multifunctional therapeutic agents in the synergistic treatment of cancer.

Synthesis and biological evaluation of surface-modified nanocellulose hydrogel loaded with paclitaxel.

Hydrogel for various applications, such as cell encapsulation and controlled release of drugs, has attracted the field of biomaterials in the past decades. Specially, research on the surface-modified nanocellulose hydrogel has grown rapidly on account of the importance of target delivery in the anti-cancer therapy. In this work, surface-modified nanocellulose was mixed with hexadecyl amine as long chains to blend to build a network to produce hydrogel, which was successfully developed for controlled and targeted delivery of paclitaxel. The pH-stimuli surface-modified nanocellulose hydrogel was characterized and biological evaluated in vitro. The hydrogel was stable at pH 7.4 and paclitaxel was released by the shape change of hydrogel in an acidic environment (pH 5.5), and the sustained release of paclitaxel was observed at pH 5.5. The vitro cytotoxicity studies indicated that the drug accumulation and the inhibition of A549 and HepG2 cells was effectively increased by the surface-modified nanocellulose hydrogel as compared with free paclitaxel. The inhibitory effect of A549 cells was improved by nearly 30% as compared with free paclitaxel and the apoptosis rate was up to 90.5% after 12 h incubation. In addition, the inversion test and the results of a series of cell experiments in vitro demonstrated a good performance of the surface-modified nanocellulose hydrogel.

Enhanced Reactive Oxygen Species Levels by an Active Benzothiazole Complex-Mediated Fenton Reaction for Highly Effective Antitumor Therapy.

Breaking the threshold of intracellular reactive oxygen species (ROS) levels can cause nonspecific oxidative damage to proteins and lead to the Fenton reaction-mediated exogenous ROS production to be a new promising anticancer strategy. However, the problems, including the inefficient transport of metal catalysts and insufficient endogenous hydrogen peroxide (H2O2) content in cells, still need to be improved. In this study, a functional nanosystem encapsulated with benzothiazole complexes (FeTB2) and the photosensitizer indocyanine green (ICG) was designed for highly effective antitumor therapy. The surface of the nanocarriers was modified with dihydroartemisinin (DHA)-grafted polyglutamic acid. The induced hyperthermia enables the lipid-polymer shell to depolymerize, releasing FeTB2. The released FeTB2 could kill tumor cells in two different ways by inhibiting DNA replication and catalyzing H2O2 to produce active •OH. Moreover, the conjugated DHA could increase the amount of peroxides in tumor cells and significantly enhance the ROS yield. This work has provided solid evidence that the present nanosystem enables a significant effect on tumor killing through the combined inhibition of DNA replication and ROS-mediated oxidative damage by regulation of the tumor microenvironment, providing a ROS-mediated high-efficiency antitumor strategy.

Investigating the role of colloids on the distribution of bisphenol analogues in surface water from an ecological demonstration area, China.

Owing to the widespread use of bisphenol analogues (BPs) as substitutes for bisphenol A (BPA), the presence of BPs in multiple environments is of increasing concern. However, there is a limited understanding of the effects of colloids on the distribution and risk assessment of BPs traditionally dissolved in surface water. In this study, seven BPs were investigated in both the truly dissolved (<5 kDa) and colloidal (5 kDa to 1 µm) phases with water, with mean concentrations in the range of 71.6-671 ng/L and 5.84-76.6 ng/L, respectively. BPA and bisphenol S (BPS) were the dominant BPs in both phases, but a clear positive correlation was found between the adsorption contribution proportions of colloids to BPs and their hydrophobicity (octanol-water partition coefficient). The colloids contributed 50.4% of bisphenol AF, 33.4% of tetrabromobisphenol A, 25.2% of bisphenol F, 10.9% of BPA and 9.50% of BPS in the traditionally dissolved phase (<1 µm), which suggests that colloids play an important role in regulating the transformation and transportation of BPs in aquatic environments. Based on BP concentrations in the truly dissolved phase, only moderate risk levels for BPs towards algae, daphnia and fish were posed, and no oestrogenic risk existed in the study area.

Reactive oxygen species mediated theranostics using a Fenton reaction activable lipo-polymersome.

Recently, reactive oxygen species (ROS)-induced apoptosis has been widely studied by researchers through various means. Among them, the singlet oxygen produced by the Fenton reaction is particularly effective in killing tumor cells. Although photodynamic therapy (PDT) takes advantage of the spatial-temporal control of ROS production, the design of the Fenton reaction in an ingenious way is still a question worth exploring. Herein, we have designed and prepared a succinic peroxide-filled Fenton reaction activable Pt/Fe3O4@SP-PLGA lipo-polymersome that displays ROS mediated chemodynamic therapy (CDT). The therapeutic element, ˙OH, is generated under NIR irradiation/tumor acidic pH environment through engineering the reaction between succinic peroxide (SP) and iron oxide. Instead of using single endogenous H2O2 or even encapsulation, the conjugation with SP in the Pt/Fe3O4@SP-PLGA lipo-polymersome provides a more stable, high-yielding peroxygen source. The results also showed that after the addition of cisplatin, the amount of ROS production increased significantly. The proof-of-concept design of the Fenton reaction activable Pt/Fe3O4@SP-PLGA lipo-polymersome with enhanced ROS-generation characteristics provides a general approach to afford potent ROS-mediated cancer therapy.

Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China.

Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values' responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky desertification areas. Understanding the vegetation ecological water consumption response to the vegetation coverage changes is essential for the vegetation restoration and water stresses mitigation in rocky desertification areas.