The effect of primary closure versus secondary closure techniques on postoperative wound pain in patients undergoing mandibular surgery: A meta-analysis.

This research is intended to explore the influence of second and first degree closure methods on the degree of wound pain and swelling of the face following the removal of the mandible. For the purpose of this study, three data sets, including PubMed and Embase, were selected. A separate statistical analysis was conducted on the choice of the trial, the collection of data and the risk of bias. Differences between trials were analysed with a chi-square approach, with data analyses dependent on I2. A sensitivity analysis was conducted, and a possible publication bias was evaluated. Ultimately, nine qualifying trials were chosen out of an original pool of 1922 related trials following an in-depth evaluation under the eligibility and exclusion criteria, as well as a follow-up screening. The results indicated that there was no statistically significant change in the degree of post-operation pain after 1 day operation between one or secondary closures of treatment (MD, -0.46; 95% CI, -0.93, 0.01, p = 0.06); the results showed that there were no statistically significant differences in post-operation wound pain after 3 days in two group (MD, -0.15; 95% CI, -0.68, 0.37, p = 0.56); the results showed that there were no statistically different effects on the post-operation wound pain after the 7th day in two groups (MD, -0.14; 95% CI, -0.31, 0.03, p = 0.1). The results showed that there were no statistically different effects on the post-operation wound pain after the 1 day in two groups (MD, -0.26; 95% CI, -0.38, -0.13, p < 0.0001); on the 3rd day after surgery, the face was significantly smaller swelling in the secondary closure of closure compared with the first-stage closure group (MD, -0.70; 95% CI, -1.40, -0.00, p = 0.05). While there is no obvious effect on post-operation wound pain in patients with mandibular surgery, there is significant difference in post-operation face swelling. The findings do not support a preference for any of these methods.

Loose Pre-Cross-Linking Mediating Cellulose Self-Assembly for 3D Printing Strong and Tough Biomimetic Scaffolds.

The lack of an effective printable ink preparation method and the usual mechanically weak performance obstruct the functional 3D printing hydrogel exploitation and application. Herein, we propose a gentle pre-cross-linking strategy to enable a loosely cross-linked cellulose network for simultaneously achieving favorable printability and a strong hydrogel network via mediating the cellulose self-assembly. A small amount of epichlorohydrin is applied to (i) slightly pre-cross-link the cellulose chains for forming the percolating network to regulate the rheological properties and (ii) form the loosely cross-linked points to mediate the cellulose chains' self-assembly for achieving superior mechanical properties. The fabrication of the complex 3D structures verifies the design flexibility. The printed cellulose hydrogels exhibit a biomimetic nanofibrous topology, remarkable tensile and compressive strength (5.22 and 11.80 MPa), as well as toughness (1.81 and 2.16 MJ/m3). As a demonstration, a bilayer scaffold (mimicking the osteochondral structure) consisting of a top pristine cellulose and a bottom cellulose/bioactive glass hydrogel is printed and exhibits superior osteochondral defect repair performance, showing a potential in tissue engineering. We anticipate that our loose pre-cross-linking 3D printing ink preparation concept can inspire the development of other polymeric inks and strong 3D printing functional hydrogels, eventually spreading the applications in diverse fields.

Golgi membrane protein GP73 modified-liposome mediates the antitumor effect of survivin promoter-driven HSVtk in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide, and there is currently no effective therapeutic strategy in clinical practice. Gene therapy has great potential for decreasing tumor-induced mortality but has been clinically limited because of the lack of tumor-specific targets and insufficient gene transfer. The study of targeted transport of therapeutic genes in HCC treatment seems to be very important. In this study, we evaluated a gene therapy approach targeting HCC using the herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) suicide gene system in HCC cell lines and in an in vivo human HCC xenograft mouse model. GP73-modified liposomes targeted gene delivery to the tumor tissue, and the survivin promoter drove HSVtk expression in the HCC cells. Our results showed that the survivin promoter was specifically activated in tumor cells and HSVtk was expressed selectively in tumor cells. Combined with GCV treatment, HSVtk expression resulted in suppression of HCC cell proliferation via enhancing apoptosis. Moreover, tail vein injection of GP73-HSVtk significantly suppressed the growth of xenograft tumors through an apoptosis-dependent pathway and extended the survival of tumor-bearing mice without damaging the mice liver functions. Taken together, this study demonstrates an effective cancer-specific gene therapy strategy using the herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) suicide gene system for HCC that can be further developed for future clinical trials.

High-Strength and Tough Cellulose Hydrogels Chemically Dual Cross-Linked by Using Low- and High-Molecular-Weight Cross-Linkers.

Hydrogels are the focus of extensive research interests due to their potential application in the fields of biomedical materials, biosensors, agriculture, and cosmetics. Natural polysaccharide is one of the good candidates of these hydrogels. However, weak mechanical properties of cellulose hydrogels greatly limit their practical application. Here, chemically dual-cross-linked cellulose hydrogels (DCHs) were constructed by sequential reaction of cellulose with low- and high-molecular-weight cross-linkers to obtain relatively short chains and long chains cross-linked networks. Both the distribution and density of the cross-linking domains in the hydrogel networks were monitored by three-dimensional Raman microscopic imaging technique. Interestingly, the ruptured stress of DCHs in tensile and compressive tests were 1.7 and 9.4 MPa, which were 26.3- and 83.9-fold larger than those of chemically single-cross-linked cellulose hydrogel. The reinforcement mechanism of DCH was proposed, as the breaking of the short-chain cross-linking in the networks effectively dissipated mechanical energy, and the extensibility of the relatively long-chain cross-linking maintained the elasticity of DCH. Therefore, both the strength and toughness of DCH was enhanced, and the dual networks consisting of short-chain and long-chain cross-linking played an important role in the improvement of the mechanical properties of the cellulose hydrogels. The application prospect of the robust cellulose hydrogels with bimodal network structure would be greatly broadened in the sustainable biopolymer fields.

Stable Graphene-Based Membrane with pH-Responsive Gates for Advanced Molecular Separation.

Graphene-based stable pH-responsive membranes (GPMs) were developed by alternative deposition of graphene oxide (GO) with polyethylenimine (PEI) in a layer-by-layer manner. Different from the conventional pore-blocking pH-responsive membranes, the size of the gaps among the GO sheets were first designed to respond to the surrounding pH. Atomic force microscopy was used to dynamically explore the internal structure alteration of GPM in the pH range from 3 to 11. It was found that the PEI molecules not only cross-linked the GO sheets through amide bonds to ensure the membrane stability but also reversibly altered the gate size of GPM in a certain extent according to the surrounding pH. In filtration, the gates of GPM were widened with the decreasing pH of the feed and vice versa. As a result, the permeate flux of GPM increased with the decreasing feed pH. More importantly, the molecular weight cutoff of GPM could be continuously regulated by the feed pH in a certain range; during the filtration of the polyvinylpyrrolidone (PVP) and polyethylene oxide (PEO) mixed solution, only PVP (58 kDa) could penetrate GPM at pH 11, while the left PEO (600 kDa) would penetrate GPM at pH 3. The controlled penetration through GPM led to a complete separation and recovery of the molecules in different sizes, which is highly desirable for advanced molecular separation in environmental applications.

Super Strong All-Cellulose Composite Filaments by Combination of Inducing Nanofiber Formation and Adding Nanofibrillated Cellulose.

In this work, super strong all-cellulose multifilaments were obtained from cellulose dissolved in LiOH/urea system by inducing nanofiber formation, and were simultaneously reinforced by the introduction of TEMPO-oxidized nanofibrillated cellulose (NFC) with mean diameter of 20 nm. The all-cellulose composite filaments (CF) containing only 3 wt % NFC exhibits a high orientation that Herman's parameter is 0.89. Importantly, the NFC can simultaneously reinforce and toughen the CF, with a tensile strength and elongation at break of 3.92 cN/dT and 14.6%, respectively, which make the obtained CF to become super strong. The strengthened mechanism of CF is considered as the nanofibril-induced crystallization and orientation, which makes up for the deficits and constructs a flawless structure in the regenerated cellulose filaments. Of note, the stability of spinning dope was also effectively improved by adding small amount of NFC, which is very important for fiber spinning on industry. This finding contributes to the preparation of high performance regenerated cellulose multifilaments by a simple, energy-efficient, and eco-friendly route.

Porous PVdF/GO Nanofibrous Membranes for Selective Separation and Recycling of Charged Organic Dyes from Water.

Graphene oxide (GO) membranes are robust and continue to attract great attention due to their fascinating properties, despite their potential issues regarding stability and selectivity in aqueous-phase processing. That being said, however, the functional moieties of GO could be used for membrane surface modification, while ensuring simultaneous removal and recycling of industrial organic dyes. Herein, we present a versatile porous structured polyvinylidene fluoride-graphene oxide (PVdF-GO) nanofibrous membranes (NFMs), prepared by using simple and straightforward electrospinning approach for selective separation and filtration. The GO nanosheets were distributed homogeneously throughout the PVdF nanofiber, regulating the surface morphology and performance of PVdF-GO NFM. The PVdF-GO NFMs possesses high mechanical strength and surface free energy (SFE), consequently resulting high permeation and filtration efficiency as compared to PVdF NFM. The selectivity (99%) toward positively charged dyes based on electrostatic attraction, while maintaining rejection (100%) for negatively charged dye from mixed solutions highlight the role of GO in PVdF-GO NFM, owing to uniform pores and negatively charged surface. In addition, the actual efficiency of NFMs could be recovered easily up to three consecutive filtration cycles by regeneration, thereby assuring high stability. The high permeation, purification and filtration efficiency, good stability and recycling of PVdF-GO NFMs are promising for use in practical water purification and applications, particularly for selective filtration and recycling of dyes.

Nanocomposite Membrane with Polyethylenimine-Grafted Graphene Oxide as a Novel Additive to Enhance Pollutant Filtration Performance.

Synthetic membranes often suffer ubiquitous fouling as well as a trade-off between permeability and selectivity. However, emerging materials which are able to mitigate membrane fouling and break the permeability and selectivity trade-off are urgently needed. A novel additive, GO-PEI, bearing a positive charge and hydrophilic nature was prepared by the covalent grafting of polyethylenimine (PEI) molecules with graphene oxide (GO) nanosheets, which later was blended with bulk poly(ether sulfone) (PES) to fabricate the graphene containing nanocomposite membranes (NCMs). Strong π-π interactions contributed to the uniform dispersion of GO-PEI nanosheets in bulk PES to form the asymmetric structure of NCM without leaching. The ratio of the GO-PEI additive regulated the surface charge and hydrophilicity of NCMs. To filter charged proteins, the designed NCM exhibited a high permeability (flux) and high selectivity (retention) while showing resistance to fouling by the charged proteins, which could be attributed to the asymmetric structure and composition of the NCM that the porous internal and surface composited with the GO-PEI additive was responsible for the NCM's high flux; thereafter, the electrostatic attraction of the NCM surface to the charged pollutant enhanced the solute/water selectivity; finally, the synergistic effect of the hydrophilic and charged functional groups of the GO-PEI contributed to the formation of a dense hydration layer on the membrane surface thereby reducing membrane fouling. The NCM functionalized with the GO-PEI additive demonstrated potential for high-performance pollutant removal in water and wastewater treatments.

High-Strength Films Consisted of Oriented Chitosan Nanofibers for Guiding Cell Growth.

Chitosan has biocompatibility and biodegradability; however, the practical use of the bulk chitosan materials is hampered by its poor strength, which can not satisfy the mechanical property requirement of organs. Thus, the construction of highly strong chitosan-based materials has attracted much attention. Herein, the high strength nanofibrous hydrogels and films (CS-E) were fabricated from the chitosan solution in LiOH/KOH/urea aqueous system via a mild regenerating process. Under the mild condition (ethanol at low temperature) without the severe fluctuation in the system, the alkaline-urea shell around the chitosan chains was destroyed, and the naked chitosan molecules had sufficient time for the orderly arrangement in parallel manner to form relatively perfect nanofibers. The nanofibers physically cross-linked to form CS-E hydrogels, which could be easily oriented by drawing to achieve a maximum orientation index of 84%, supported by the scanning electron microscopy and two-dimensional wide-angle X-ray diffraction. The dried CS-E films could be bent and folded arbitrarily to various complex patterns and shapes. The oriented CS-E films displayed even ultrahigh tensile strength (282 MPa), which was 5.6× higher than the chitosan films prepared by the traditional acid dissolving method. The CS-E hydrogels possessed hierarchically porous structure, beneficial to the cell adhesion, transportation of nutrients, and removal of metabolic byproducts. The cell assay results demonstrated that the CS-E hydrogels were no cytotoxicity, and osteoblastic cells could adhere, spread, and proliferate well on their surface. Furthermore, the oriented CS-E hydrogels could regulate the directional growth of osteoblastic cells along the orientation direction, on the basis of the filopodia of the cells to extend and adhere on the nanofibers. This work provided a novel approach to construct the oriented high strength chitosan hydrogels and films.

Hierarchical Microspheres Constructed from Chitin Nanofibers Penetrated Hydroxyapatite Crystals for Bone Regeneration.

Chitin exists abundantly in crab and shrimp shells as the template of the minerals, which inspired us to mineralize it for fabricating bone grafting materials. In the present work, chitin nanofibrous microspheres were used as the matrix for in situ synthesis of hydroxyapatite (HA) crystals including microflakes, submicron-needles, and submicron-spheres, which were penetrated by long chitin nanofibers, leading to the hierarchical structure. The shape and size of the HA crystals could be controlled by changing the HA synthesis process. The tight interface adhesion between chitin and HA through the noncovanlent bonds occurred in the composite microspheres, and HAs were homogeneously dispersed and bounded to the chitin nanofibers. In our findings, the inherent biocompatibilities of the both chitin and HA contributed the bone cell adhesion and osteoconduction. Moreover, the chitin microsphere with submicron-needle and submicron-sphere HA crystals remarkably promoted in vitro cell adhesion and in vivo bone healing. It was demonstrated that rabbits with 1.5 cm radius defect were almost cured completely within three months in a growth factor- and cell-free state, as a result of the unique surface microstructure and biocompatibilities of the composite microspheres. The microsphere scaffold displayed excellent biofunctions and an appropriate biodegradability. This work opened up a new avenue to construct natural polymer-based organic-inorganic hybrid microspheres for bone regeneration.

Paper-Based Device for Colorimetric and Photoelectrochemical Quantification of the Flux of H2O2 Releasing from MCF-7 Cancer Cells.

In this work, a novel dual photoelectrochemical/colorimetric cyto-analysis format was first introduced into a microfluidic paper-based analytical device (µ-PAD) for synchronous sensitive and visual detection of H2O2 released from tumor cells based on an in situ hydroxyl radicals ((•)OH) cleaving DNA approach. The resulted µ-PAD offered an excellent platform for high-performance biosensing applications, which was constructed by a layer-by-layer modification of concanavalin A, graphene quantum dots (GQDs) labeled flower-like Au@Pd alloy nanoparticles (NPs) probe, and tumor cells on the surface of the vertically aligned bamboo like ZnO, which grows on a pyknotic Pt NPs modified paper working electrode (ZnO/Pt-PWE). It was the effective matching of energy levels between GQDs and ZnO levels that lead to the enhancement of the photocurrent response compared with the bare ZnO/Pt-PWE. After releasing H2O2, the DNA strand was cleaved by (•)OH generated under the synergistic catalysis of GQDs and Au@Pd alloy NPs and thus, reduced the photocurrent, resulting in a high sensitivity to H2O2 in aqueous solutions with a detection limit of 0.05 nmol observed, much lower than that in the previously reported method. The disengaged probe can result in catalytic chromogenic reaction of substrates, resulting in real-time imaging of H2O2 biological processes. Therefore, this work provided a truly low-cost, simple, and disposable µ-PAD for precise and visual detection of cellular H2O2, which had potential utility to cellular biology and pathophysiology.

Improved Mechanical Properties and Sustained Release Behavior of Cationic Cellulose Nanocrystals Reinforeced Cationic Cellulose Injectable Hydrogels.

Polysaccharide-based injectable hydrogels have several advantages in the context of biomedical use. However, the main obstruction associated with the utilization of these hydrogels in clinical application is their poor mechanical properties. Herein, we describe in situ gelling of nanocomposite hydrogels based on quaternized cellulose (QC) and rigid rod-like cationic cellulose nanocrystals (CCNCs), which can overcome this challenge. In all cases, gelation immediately occurred with an increase of temperature, and the CCNCs were evenly distributed throughout the hydrogels. The nanocomposite hydrogels exhibited increasing orders-of-magnitude in the mechanical strength, high extension in degradation and the sustained release time, because of the strong interaction between CCNCs and QC chains mediated by the cross-linking agent (ß-glycerophosphate, ß-GP). The results of the in vitro toxicity and in vivo biocompatibility tests revealed that the hydrogels did not show obvious cytotoxicity and inflammatory reaction to cells and tissue. Moreover, DOX-encapsulated hydrogels were injected beside the tumors of mice bearing liver cancer xenografts to assess the potential utility as localized and sustained drug delivery depot systems for anticancer therapy. The results suggested that the QC/CCNC/ß-GP nanocomposite hydrogels had great potential for application in subcutaneous and sustained delivery of anticancer drug to increase therapeutic efficacy and improve patient compliance.

Reinforced Mechanical Properties and Tunable Biodegradability in Nanoporous Cellulose Gels: Poly(L-lactide-co-caprolactone) Nanocomposites.

Incorporation of nanofillers into aliphatic polyesters is a convenient approach to create new nanomaterials with significantly reinforced mechanical properties compared to the neat polymers or conventional composites. Nanoporous cellulose gels (NCG) prepared from aqueous alkali hydroxide/urea solutions can act as alternative reinforcement nanomaterials for polymers with improved mechanical properties. We report a simple and versatile process for the fabrication of NCG/poly(L-lactide-co-caprolactone) (NCG/P(LLA-co-CL) nanocomposites through in situ ring-opening polymerization of L-lactide (LLA) and ε-caprolactone (ε-CL) monomers in the NCG. The volume fraction of the NCG in the nanocomposites was tunable and ranged from 4.5% to 37%. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) results indicated that P(LLA-co-CL) were synthesized within the NCG and partially grafted onto the surface of the cellulose nanofibrils. The glass-transition temperature (Tg) of the NCG/P(LLA-co-CL) nanocomposites could be altered by varying the molar ratio of LLA/ε-CL and was affected by the volume fraction of NCG. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) images confirmed that the interconnected nanofibrillar cellulose network structure of the NCG was finely distributed and preserved in the P(LLA-co-CL) matrix after polymerization. The dynamic mechanical analysis (DMA) results showed remarkable reinforcement of the tensile storage modulus (E') of the P(LLA-co-CL) nanocomposites in the presence of NCG, especially above the Tg of the P(LLA-co-CL). The modified percolation model agreed well with the mechanical properties of the NCG/P(LLA-co-CL) nanocomposites. The introduction of NCG into the P(LLA-co-CL) matrix improved the mechanical properties and thermal stability of the NCG/P(LLA-co-CL) nanocomposites. Moreover, the NCG/P(LLA-co-CL) nanocomposites have tunable biodegradability and biocompatibility and potential applications in tissue engineering repair, biomedical implants, and packing.

Effects of Chitin Whiskers on Physical Properties and Osteoblast Culture of Alginate Based Nanocomposite Hydrogels.

Novel nanocomposite hydrogels composed of polyelectrolytes alginate and chitin whiskers with biocompatibility were successfully fabricated based on the pH-induced charge shifting behavior of chitin whiskers. The chitin whiskers with mean length and width of 300 and 20 nm were uniformly dispersed in negatively charged sodium alginate aqueous solution, leading to the formation of the homogeneous nanocomposite hydrogels. The experimental results indicated that their mechanical properties were significantly improved compared to alginate hydrogel and the swelling trends were inhibited as a result of the strong electrostatic interactions between the chitin whiskers and alginate. The nanocomposite hydrogels exhibited certain crystallinity and hierarchical structure with nanoscale chitin whiskers, similar to the structure of the native extracellular matrix. Moreover, the nanocomposite hydrogels were successfully applied as bone scaffolds for MC3T3-E1 osteoblast cells, showing their excellent biocompatibility and low cytotoxicity. The results of fluorescent micrographs and scanning electronic microscope (SEM) images revealed that the addition of chitin whiskers into the nanocomposite hydrogels markedly promoted the cell adhesion and proliferation of the osteoblast cells. The biocompatible nanocomposite hydrogels have potential application in bone tissue engineering.

Accuracy of cone-beam computed tomography in detecting alveolar bone dehiscences and fenestrations.

INTRODUCTION: The purposes of this study were to evaluate the accuracy of cone-beam computed tomography (CBCT) for detecting naturally occurring alveolar bone dehiscences and fenestrations and to find a better method to diagnose them. METHODS: The sample consisted of 122 anterior teeth in 14 patients with Class III malocclusion who accepted accelerated osteogenic orthodontic surgery in the anterior tooth region. Dehiscences and fenestrations were measured both directly, with a gauge during surgery, and indirectly, by CBCT scans collected before treatment. A Bland-Altman plot for calculating agreement between the 2 methods was used. Direct data were regarded as the gold standard, and indirect data were analyzed to evaluate the accuracy of CBCT for detecting dehiscences and fenestrations by sensitivity, specificity, positive predictive value, negative predictive value, Youden index, positive likelihood ratio, and negative likelihood ratio. Receiver operator characteristic curves were also used to determine the area under curve and the best critical points of CBCT for detecting dehiscences and fenestrations. RESULTS: Both the sensitivity and specificity of CBCT for dehiscences and fenestrations were over 0.7. The negative predictive values were high (dehiscence, 0.82; fenestration, 0.98), whereas the positive predictive values were relatively low (dehiscence, 0.75; fenestration, 0.16). Areas under the curve were 0.873 for dehiscences and 0.766 for fenestrations. The best critical points for detecting both dehiscences and fenestrations were 2.2 mm. CONCLUSIONS: Our study showed that the CBCT method has some diagnostic value for detecting naturally occurring alveolar bone dehiscences and fenestrations. However, this method might overestimate the actual measurements.

Highly biocompatible nanofibrous microspheres self-assembled from chitin in NaOH/urea aqueous solution as cell carriers.

In this work, chitin microspheres (NCM) having a nanofibrous architecture were constructed using a "bottom-up" fabrication pathway. The chitin chains rapidly self-assembled into nanofibers in NaOH/urea aqueous solution by a thermally induced method and subsequently formed weaved microspheres. The diameter of the chitin nanofibers and the size of the NCM were tunable by controlling the temperature and the processing parameters to be in the range from 26 to 55 nm and 3 to 130 µm, respectively. As a result of the nanofibrous surface and the inherent biocompatibility of chitin, cells could adhere to the chitin microspheres and showed a high attachment efficiency, indicating the great potential of the NCM for 3D cell microcarriers.

Construction of chitin/PVA composite hydrogels with jellyfish gel-like structure and their biocompatibility.

High strength chitin/poly(vinyl alcohol) (PVA) composite hydrogels (RCP) were constructed by adding PVA into chitin dissolved in a NaOH/urea aqueous solution, and then by cross-linking with epichlorohydrin (ECH) and freezing-thawing process. The RCP hydrogels were characterized by field emission scanning electron microscopy, FTIR, differential scanning calorimetry, solid-state (13)C NMR, wide-angle X-ray diffraction, and compressive test. The results revealed that the repeated freezing/thawing cycles induced the bicrosslinked networks consisted of chitin and PVA crystals in the composite gels. Interestingly, a jellyfish gel-like structure occurred in the RCP75 gel with 25 wt % PVA content in which the amorphous and crystalline PVA were immobilized tightly in the chitin matrix through hydrogen bonding interaction. The freezing/thawing cycles played an important role in the formation of the layered porous PVA networks and the tight combining of PVA with the pore wall of chitin. The mechanical properties of RCP75 were much higher than the other RCP gels, and the compressive strength was 20× higher than that of pure chitin gels, as a result of broadly dispersing stress caused by the orderly multilayered networks. Furthermore, the cell culture tests indicated that the chitin/PVA composite hydrogels exhibited excellent biocompatibility and safety, showing potential applications in the field of tissue engineering.

In situ synthesis of robust conductive cellulose/polypyrrole composite aerogels and their potential application in nerve regeneration.

Nanostructured conductive polymers can offer analogous environments for extracellular matrix and induce cellular responses by electric stimulation, however, such materials often lack mechanical strength and tend to collapse under small stresses. We prepared electrically conductive nanoporous materials by coating nanoporous cellulose gels (NCG) with polypyrrole (PPy) nanoparticles, which were synthesized in situ from pyrrole monomers supplied as vapor. The resulting NCG/PPy composite hydrogels were converted to aerogels by drying with supercritical CO2, giving a density of 0.41-0.53 g cm(-3), nitrogen adsorption surface areas of 264-303 m(2) g(-1), and high mechanical strength. The NCG/PPy composite hydrogels exhibited an electrical conductivity of up to 0.08 S cm(-1). In vitro studies showed that the incorporation of PPy into an NCG enhances the adhesion and proliferation of PC12 cells. Electrical stimulation demonstrated that PC12 cells attached and extended longer neurites when cultured on NCG/PPy composite gels with DBSA dopant. These materials are promising candidates for applications in nerve regeneration, carbon capture, catalyst supports, and many others.

Enhancing stem cell therapy efficacy with functional lignin modified cerium-iron nanozyme through magnetic resonance imaging tracking and apoptosis protection in inflammatory environment.

Stem cell transplantation provides a promising approach for addressing inflammation and functional disorders. Nonetheless, the viability of these transplanted cells diminishes significantly within pathological environments, limiting their therapeutic potential. Moreover, the non-invasive tracking of these cells in vivo remains a considerable challenge, hampering the assessment of their therapeutic efficacy. Transition-metal oxide nanocrystals, known for their unique "enzyme-like" catalytic property and imaging capability, provide a new avenue for clinical application. In this study, the lignin as a biocompatible macromolecule was modified with poly (ethylene glycol) through chain-transfer polymerization, and then it was utilized to incorporate superparamagnetic iron oxide and cerium oxide nanocrystals creating a functional nanozyme. The iron oxide nanocrystals self-assembled into the hydrophobic core of nano system, while the in-situ mineralization of cerium oxide particles was carried out with the assistance of peripheral phenolic hydroxyl groups. The product, cerium­iron core-shell nanozyme, enabled effective stem cells labeling through endocytosis and exhibited catalase and superoxide dismutase activities within the cells. As a result, it could scavenge highly destructive hydroxyl radicals and peroxyl radicals, shielding stem cells from apoptosis in inflammatory environment and maintaining their differentiation ability. Additionally, when these functionalized stem cells were administered to mice with acute inflammation, not only did they alleviate disease symptoms, but they also allowed for the visualization using T2-weighted magnetic resonance imaging. This innovative therapeutic approach provides a new strategy for combatting diseases.

Mitochondrial Targeted Thermosensitive Nanocarrier for Near-Infrared-Triggered Precise Synergetic Photothermal Nitric Oxide Chemotherapy.

Nitric oxide (NO) intervenes, that is, a potential treatment strategy, and has attracted wide attention in the field of tumor therapy. However, the therapeutic effect of NO is still poor, due to its short half-life and instability. Therapeutic concentration ranges of NO should be delivered to the target tissue sites, cell, and even subcellular organelles and to control NO generation. Mitochondria have been considered a major target in cancer therapy for their essential roles in cancer cell metabolism and apoptosis. In this study, mesoporous silicon-coated gold nanorods encapsulated with a mitochondria targeted and the thermosensitive lipid layer (AuNR@MSN-lipid-DOX) served as the carrier to load NO prodrug (BNN6) to build the near-infrared-triggered synergetic photothermal NO-chemotherapy platform (AuNR@MSN(BNN6)-lipid-DOX). The core of AuNR@MSN exhibited excellent photothermal conversion capability and high loading efficiency in terms of BNN6, reaching a high value of 220 mg/g (w/w), which achieved near-infrared-triggered precise release of NO. The outer biocompatible lipid layer, comprising thermosensitive phospholipid DPPC and mitochondrial-targeted DSPE-PEG2000-DOX, guided the whole nanoparticle to the mitochondria of 4T1 cells observed through confocal microscopy. In the mitochondria, the nanoparticles increased the local temperature over 42 °C under NIR irradiation, and a high NO concentration from BNN6 detected by the NO probe and DSPE-PEG2000-DOX significantly inhibited 4T1 cancer cells in vitro and in vivo under the synergetic photothermal therapy (PTT)-NO therapy-chemotherapy modes. The built NIR-triggered combination therapy nanoplatform can serve as a strategy for multimodal collaboration.