Bone defects cause significant socio-economic costs worldwide, while the clinical “gold standard” of bone repair, the autologous bone graft, has limitations including limited graft supply, secondary ...injury, chronic pain and infection. Therefore, to reduce surgical complexity and speed up bone healing, innovative therapies are needed. Bone tissue engineering (BTE), a new cross-disciplinary science arisen in the 21st century, creates artificial environments specially constructed to facilitate bone regeneration and growth. By combining stem cells, scaffolds and growth factors, BTE fabricates biological substitutes to restore the functions of injured bone. Although BTE has made many valuable achievements, there remain some unsolved challenges. In this review, the latest research and application of stem cells, scaffolds, and growth factors in BTE are summarized with the aim of providing references for the clinical application of BTE.
Functional materials displaying tunable emission and long-lived luminescence have recently emerged as a powerful tool for applications in information encryption, organic electronics and ...bioelectronics. Herein, we present a design strategy to achieve color-tunable ultralong organic room temperature phosphorescence (UOP) in polymers through radical multicomponent cross-linked copolymerization. Our experiments reveal that by changing the excitation wavelength from 254 to 370 nm, these polymers display multicolor luminescence spanning from blue to yellow with a long-lived lifetime of 1.2 s and a maximum phosphorescence quantum yield of 37.5% under ambient conditions. Moreover, we explore the application of these polymers in multilevel information encryption based on the color-tunable UOP property. This strategy paves the way for the development of multicolor bio-labels and smart luminescent materials with long-lived emission at room temperature.
Uncontrolled cancer cell proliferation, insufficient blood flow, and inadequate endogenous oxygen lead to hypoxia in tumor tissues. Herein, a unique type of hypoxia‐responsive human serum albumin ...(HSA)‐based nanosystem (HCHOA) is reported, prepared by cross‐linking the hypoxia‐sensitive azobenzene group between photosensitizer chlorin e6 (Ce6)‐conjugated HSA (HC) and oxaliplatin prodrug‐conjugated HSA (HO). The HCHOA nanosystem is stable under normal oxygen partial pressure with a size of 100–150 nm. When exposed to the hypoxic tumor microenvironment, the nanosystem can quickly dissociate into ultrasmall HC and HO therapeutic nanoparticles with a diameter smaller than 10 nm, significantly enabling their enhanced intratumoral penetration. After the dissociation, the quenched fluorescence of Ce6 in the produced HC nanoparticles can be recovered for bioimaging. At the same time, the production of singlet oxygen is increased because of the enhancement in the photoactivity of the photosensitizer. On account of these improvements, combined photodynamic therapy and chemotherapy is realized to display superior antitumor efficacy in vivo. Based on this simple strategy, it is possible to achieve the dissociation of hypoxic‐responsive nanosystem to enhance the tumor penetration and therapeutic effect.
A hypoxia‐responsive albumin‐based nanosystem can be dissociated into individual therapeutic agents with sizes below 10 nm for increased intratumoral permeability under a tumor's hypoxic environment. The photoactivity of the loaded chlorin e6 is activated with recovered fluorescence and increased singlet oxygen production, achieving superior antitumor treatment on animal models through combined photodynamic therapy and chemotherapy.
As an effective conventional absorbent, biochar exhibited limited adsorption ability toward small hydrophobic molecules. To enhance the adsorption capacity, a novel adsorbent was prepared by ...immobilizing nanoscale zero-valent iron onto modified biochar（MB） and then the elemental silver was attached to the surface of iron（Ag/Fe/MB）. It＇s noted that spherical Ag/Fe nanoparticles with diameter of 51 nm were highly dispersed on the surface of MB. As the typical hydrophobic contaminant, carbon tetrachloride was selected for examining the removal efficiency of the adsorbent. The removal efficiencies of carbon tetrachloride by original biochar（OB）, Ag/Fe, Ag/Fe/OB and Ag/Fe/MB were fully investigated. It＇s found that Ag/Fe/MB showed higher carbon tetrachloride removal efficiency, which is about 5.5 times higher than that of the OB sample due to utilizing the merits of high adsorption and reduction. Thermodynamic parameters revealed that the removal of carbon tetrachloride by Ag/Fe/MB was a spontaneous and exothermic process, which was affected by solution p H, initial carbon tetrachloride concentration and temperature. The novel Ag/Fe/MB composites provided a promising material for carbon tetrachloride removal from effluent.
A novel type of flexible fiber/wearable supercapacitor that is composed of two fiber electrodes – a helical spacer wire and an electrolyte – is demonstrated. In the carbon‐based fiber supercapacitor ...(FSC), which has high capacitance performance, commercial pen ink is directly utilized as the electrochemical material. FSCs have potential benefits in the pursuit of low‐cost, large‐scale, and efficient flexible/wearable energy storage systems.
Abstract
Critical-sized bone defects often lead to non-union and full-thickness defects of the calvarium specifically still present reconstructive challenges. In this study, we show that neurotrophic ...supplements induce robust in vitro expansion of mesenchymal stromal cells, and in situ transplantation of neurotrophic supplements-incorporated 3D-printed hydrogel grafts promote full-thickness regeneration of critical-sized bone defects. Single-cell RNA sequencing analysis reveals that a unique atlas of in situ stem/progenitor cells is generated during the calvarial bone healing in vivo. Notably, we find a local expansion of resident Msx1+ skeletal stem cells after transplantation of the in situ cell culture system. Moreover, the enhanced calvarial bone regeneration is accompanied by an increased endochondral ossification that closely correlates to the Msx1+ skeletal stem cells. Our findings illustrate the time-saving and regenerative efficacy of in situ cell culture systems targeting major cell subpopulations in vivo for rapid bone tissue regeneration.
This paper focuses on the effectiveness of removing ammonium ion and the theoretical aspects of adsorption including adsorption isotherm, kinetics and thermodynamics as well as ...desorption–regeneration studies. Results have demonstrated that natural zeolite shows good performance with up to 97% for ammonium removal depending on contact time, zeolite loading, initial ammonium concentration and pH. The adsorption kinetics is best approximated by the pseudo-second-order model, whereas the adsorption isotherm results indicated that Freundlich model provides the best fit for the equilibrium data. Furthermore, with regard to thermodynamic parameters, it was found that Gibbs free energy change or adsorption energy (ΔG°), −
19.52
kJ/mol at 25
°C, −
20.45
kJ/mol at 35
°C and −
22.91
kJ/mol at 45
°C is negative indicating the spontaneous nature of the adsorption process, whereas the enthalpy change (Δ
H°), 30.96
kJ/mol is positive indicating endothermic adsorption process. The entropy change (Δ
S°), 0.169
kJ/(mol K) at 25
°C is also positive indicating increasing randomness at the solid-solution interface during adsorption. In addition, the desorption–regeneration studies demonstrated that desorption of ammonium on the zeolite is sufficiently high using NaCl solutions.
► Natural zeolite was used to remove ammonium. ► The natural zeolite shows good performance for ammonium removal with up to 97%. ► The performance depends on the contact time, zeolite loading, initial ammonium concentration and pH. ► The adsorption kinetics is best approximated by the pseudo-second-order model. ► Freundlich model provides the best fit for the adsorption isotherm result.
•Hydrolysis of cellulose and biomass in hot-compressed GVL/water (HCGW) is studied.•Reaction rate and glucose recovery from cellulose hydrolysis in HCGW are increased.•GVL addition enhances ...hydrolysis reactions but suppresses isomerization reactions.•GVL/water co-solvent is an excellent reaction medium for biomass hydrolysis.
This study employs a semi-continuous reactor system to investigate the solvent effect of gamma-valerolactone (GVL) on cellulose hydrolysis in hot-compressed GVL/water (HCGW) at 250 °C and 10 MPa. The primary liquid products from cellulose hydrolysis in HCGW at various GVL concentrations are collected and characterised. Both hydrolysis reaction rate and final glucose recovery are found to increase with GVL concentration, with a high glucose recovery of 91% achieved in the primary liquid products of cellulose hydrolysis in 10% GVL/water. Further analyses of the primary liquid products using high performance anion exchange chromatography with pulsed amperometric detection show the reductions in the isomers of glucose oligomers (with reducing end as fructose and mannose) and the increases in the glucose oligomers with low degrees of polymerisation, indicating that GVL addition enhances hydrolysis reactions but suppresses isomerization reactions in the solid phase. Similar effects are also found in the secondary reactions of the primary liquid products during cellulose hydrolysis at reduced flow rates. The experimental results from biomass hydrolysis clearly demonstrate that GVL/water co-solvent is an excellent reaction medium for biomass hydrolysis under acid-free conditions, achieving a near-complete sugar recovery (i.e., 93%) at a low GVL concentration of 5%.
Fly ash is a waste substance from thermal power plants, steel mills, etc. that is found in abundance in the world. In recent years, utilisation of fly ash has gained much attention in public and ...industry, which will help reduce the environmental burden and enhance economic benefit. In this paper, the technical feasibility of utilisation of fly ash as a low-cost adsorbent for various adsorption processes for removal of pollutants in air and water systems has been reviewed. Instead of using commercial activated carbon or zeolites, a lot of researches have been conducted using fly ash for adsorption of NO
x
, SO
x
, organic compounds, and mercury in air, and cations, anions, dyes and other organic matters in waters. It is recognised that fly ash is a promising adsorbent for removal of various pollutants. Chemical treatment of fly ash will make conversion of fly ash into a more efficient adsorbent for gas and water cleaning. Investigations also revealed that unburned carbon component in fly ash plays an important role in adsorption capacity. Directions for future research are also discussed.
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