From microporous to mesoporous mineral frameworks: An alliance between zeolite and chitosan

Hydrogen energy systems: Technologies, trends, and future prospects

This review critically examines hydrogen energy systems, highlighting their capacity to transform the global energy framework and mitigate climate change. Hydrogen showcases a high energy density of 120 MJ/kg, providing a robust alternative to fossil fuels. Adoption at scale could decrease global CO2 emissions by up to 830 million tonnes annually. Despite its potential, the expansion of hydrogen technology is curtailed by the inefficiency of current electrolysis methods and high production costs. Presently, electrolysis efficiencies range between 60 % and 80 %, with hydrogen production costs around $5 per kilogram. Strategic advancements are necessary to reduce these costs below $2 per kilogram and push efficiencies above 80 %. Additionally, hydrogen storage poses its own challenges, requiring conditions of up to 700 bar or temperatures below -253 °C. These storage conditions necessitate the development of advanced materials and infrastructure improvements. The findings of this study emphasize the need for comprehensive strategic planning and interdisciplinary efforts to maximize hydrogen's role as a sustainable energy source. Enhancing the economic viability and market integration of hydrogen will depend critically on overcoming these technological and infrastructural challenges, supported by robust regulatory frameworks. This comprehensive approach will ensure that hydrogen energy can significantly contribute to a sustainable and low-carbon future.

Impact of adding zeolite to broilers' diet and litter on growth, blood parameters, immunity, and ammonia emission

This work was designed to assess the impact of varying zeolite concentrations in diet and litter to enhance broiler's growth performance, immunity, and litter quality. A complete random arrangement was used for distributing 525 unsexed "Cobb 500" broiler chicks into seven treatments (75 chick / treatment), each treatment divided into 3 replicates (25 chicks / replicate). The 1st group (control one) received the recommended basal diet. Zeolite has been introduced to the basal diet (ZD) of the second, third, and fourth groups at concentrations of 5, 10, and 15 g/kg, respectively. The 5th, 6th and 7th groups used zeolite mixed with litter (ZL) at 0.5, 1, and 1.5 kg/m2 of litter, respectively. Due to the obtained results, adding zeolite with levels 15 g/kg of diet and 1.5 kg/1 m2 of litter, a significant improvement occurred in live body weight (LBW), body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) and European production efficiency factor (EPEF). Also, transaminase enzymes (ALT and AST), creatinine, white blood cells (WBCs) and different Immunoglobulins were significantly increased with different zeolite levels, except urea concentrations which showed reduced due to different zeolite treatments. In addition, spleen relative weight hasn't been affected by zeolite treatments, even though thymus and bursa relative weights had been affected significantly. Moreover, the antibodies' production to Newcastle disease virus (NDV) and Avian influenza virus (AIV) had increased significantly with adding zeolite with levels 10 g/kg of diet and 1.5 kg/1m2 of litter. Litter quality traits (NH3 concentration, pH values, and Moisture content) were improved with zeolite addition. So, zeolite could be employed in both feed and litter of broilers to maximize their production, immunity and improve farm's climate.

Manufacturing Options for Activated Carbons with Selected Synthetic Polymers as Binders

Formed activated carbon (AC) is a multipurpose product with developed adsorption properties that is widely used in various areas of life. To create AC, hard coal has to go through various processes: grinding, granulation, carbonization, physical and/or chemical activation. Presented research was conducted in the professional company manufacturing activated carbons. Studied AC reached the demanded shape of grains thanks to binders added to granulation process. Research on the AC formed using new polymeric binders (applied so far in other branches: pharmacy and construction materials) is presented in this manuscript. Tested binders were not used before to manufacture ACs in the professional technological line. Such polymers as: sodium carboxymethylhydrocellulose (CMHC), poly[1-(2-oxo-1-pyrrolidinyl)ethylene] (POPE) and enriched methyl-hydroxypropyl cellulose MHPC were studied in this work. Conducted research has proven efficiency of 8% CMHC which allowed for proper granulation and carbonization and reached the best parameters. Single- and double-stage activation was investigated for AC with this binder. For newly manufactured AC BET surface and pore volume increased accordingly from 774 m2/g and 0.58 cm3/g (1-stage) to 968 m2/g and 0.72 cm3/g (2-stage). Chemical elemental features of surface of the best AC showed beside elementary carbon also calcium, silicon and aluminum ions as well as groups with an acidic character, phosphates, sulphates and chlorides. The new AC had a higher Mechanical Strength reaching 99.9% and a lower Ash content and Volatile Matter than AC manufactured with previous binder-molasse. The new AC is intended to be directed for full production line and implementation to usage after positive certification. It may be useful in water treatment. It will also find application in the treatment of industrial and municipal wastewater.

Chitosan nanocomposite for tissue engineering and regenerative medicine: A review

Regenerative medicine and tissue engineering have emerged as a multidisciplinary promising field in the quest to address the limitations of traditional medical approaches. One of the key aspects of these fields is the development of such types of biomaterials that can mimic the extracellular matrix and provide a conducive environment for tissue regeneration. In this regard, chitosan has played a vital role which is a naturally derived linear bi-poly-aminosaccharide, and has gained significant attention due to its biocompatibility and unique properties. Chitosan possesses many unique physicochemical properties, making it a significant polysaccharide for different applications such as agriculture, nutraceutical, biomedical, food, nutraceutical, packaging, etc. as well as significant material for developing next-generation hydrogel and bio-scaffolds for regenerative medicinal applications. Moreover, chitosan can be easily modified to incorporate desirable properties, such as improved mechanical strength, enhanced biodegradability, and controlled release of bioactive molecules. Blending chitosan with other polymers or incorporating nanoparticles into its matrix further expands its potential in tissue engineering applications. This review summarizes the most recent studies of the last 10 years based on chitosan, blends, and nanocomposites and their application in bone tissue engineering, hard tissue engineering, dental implants, dental tissue engineering, dental fillers, and cartilage tissue engineering.

Biopolymers for Tissue Engineering: Crosslinking, Printing Techniques, and Applications

Currently, tissue engineering has been dedicated to the development of 3D structures through bioprinting techniques that aim to obtain personalized, dynamic, and complex hydrogel 3D structures. Among the different materials used for the fabrication of such structures, proteins and polysaccharides are the main biological compounds (biopolymers) selected for the bioink formulation. These biomaterials obtained from natural sources are commonly compatible with tissues and cells (biocompatibility), friendly with biological digestion processes (biodegradability), and provide specific macromolecular structural and mechanical properties (biomimicry). However, the rheological behaviors of these natural-based bioinks constitute the main challenge of the cell-laden printing process (bioprinting). For this reason, bioprinting usually requires chemical modifications and/or inter-macromolecular crosslinking. In this sense, a comprehensive analysis describing these biopolymers (natural proteins and polysaccharides)-based bioinks, their modifications, and their stimuli-responsive nature is performed. This manuscript is organized into three sections: (1) tissue engineering application, (2) crosslinking, and (3) bioprinting techniques, analyzing the current challenges and strengths of biopolymers in bioprinting. In conclusion, all hydrogels try to resemble extracellular matrix properties for bioprinted structures while maintaining good printability and stability during the printing process.

Using Natural Zeolite as a Feed Additive in Broilers' Diets for Enhancing Growth Performance, Carcass Characteristics, and Meat Quality Traits

BACKGROUND

Using natural zeolites as a food additive in poultry diets offers an intriguing perspective. The objective of this study was to investigate the effects of zeolite addition and particle size on broiler performance, carcass characteristics, meat quality, moisture of excreta and litter, and intestinal measurements during 35 days.

METHODS

A total of 560 1-day-old female Ross-308 broilers were divided into five treatment levels (0, 5, 10, 15, and 20 g zeolite/kg diet) (n = 16 replicates/treatment, n = 8 replicates /particle size of each treatment). Performance was calculated weekly. Carcass characteristics, meat quality, small intestine (SI) measurements, litter pH, and moisture content were determined on day 35.

RESULTS

Litter pH, breast redness, cooking loss, chewiness, total weight, and SI length were all affected by zeolite treatments (p < 0.05). Particle size had an impact on the gastric pH and texture analysis. Their interaction had an effect on color redness, litter pH, and cooking loss. Performance was unaffected by either the main or interaction effects.

CONCLUSION

Zeolite as a feed additive may be useful in broiler diets, particularly large particles. The performance and production efficiency factor improved numerically (p > 0.05) with increasing zeolite doses up to 10 g zeolite/kg diet.

2D Organic Materials: Status and Challenges

In the past few decades, 2D layer materials have gradually become a central focus in materials science owing to their uniquely layered structural qualities and good optoelectronic properties. However, in the development of 2D materials, several disadvantages, such as limited types of materials and the inability to synthesize large-scale materials, severely confine their application. Therefore, further exploration of new materials and preparation methods is necessary to meet technological developmental needs. Organic molecular materials have the advantage of being customizable. Therefore, if organic molecular and 2D materials are combined, the resulting 2D organic materials would have excellent optical and electrical properties. In addition, through this combination, the free design and large-scale synthesis of 2D materials can be realized in principle. Furthermore, 2D organic materials exhibit excellent properties and unique functionalities along with great potential for developing sensors, biomedicine, and electronics. In this review, 2D organic materials are divided into five categories. The preparation methods and material properties of each class of materials are also described in detail. Notably, to comprehensively understand each material's advantages, the latest research applications for each material are presented in detail and summarized. Finally, the future development and application prospects of 2D organic materials are briefly discussed.

Chitosan - zeolite scaffold as a potential biomaterial in the controlled release of drugs for osteoporosis

Chitosan scaffolds are a potential material in many biomedical applications. A particularly interesting application is their use in bone tissue engineering. Because of their biocompatibility and nontoxicity, they are an ideal material for this application. What is missing from chitosan scaffolds is controlled drug release. They can obtain this property by adding drug carriers. In this work, chitosan‑calcium zeolite scaffolds were prepared and used in the controlled release of the drug for osteoporosis - risedronate. Their properties have been compared with those of the popular chitosan-hydroxyapatite scaffold. The zeolite was evenly distributed throughout the scaffold. More drug was retained on the scaffold with the addition of zeolite compared to that with the hydroxyapatite. The new scaffolds have proven to be able to retain the drug and slowly release it in small doses. The results obtained are promising and show great potential for this material in bone tissue engineering.

Recent Advances in Macroporous Hydrogels for Cell Behavior and Tissue Engineering

Hydrogels have been extensively used as scaffolds in tissue engineering for cell adhesion, proliferation, migration, and differentiation because of their high-water content and biocompatibility similarity to the extracellular matrix. However, submicron or nanosized pore networks within hydrogels severely limit cell survival and tissue regeneration. In recent years, the application of macroporous hydrogels in tissue engineering has received considerable attention. The macroporous structure not only facilitates nutrient transportation and metabolite discharge but also provides more space for cell behavior and tissue formation. Several strategies for creating and functionalizing macroporous hydrogels have been reported. This review began with an overview of the advantages and challenges of macroporous hydrogels in the regulation of cellular behavior. In addition, advanced methods for the preparation of macroporous hydrogels to modulate cellular behavior were discussed. Finally, future research in related fields was discussed.

Neat Chitosan Porous Materials: A Review of Preparation, Structure Characterization and Application

This review presents an overview of methods for preparing chitosan-derived porous materials and discusses their potential applications. This family of materials has garnered significant attention owing to their biocompatibility, nontoxicity, antibacterial properties, and biodegradability, which make them advantageous in a wide range of applications. Although individual porous chitosan-based materials have been widely discussed in the literature, a summary of all available methods for preparing materials based on pure chitosan, along with their structural characterization and potential applications, has not yet been presented. This review discusses five strategies for fabricating porous chitosan materials, i.e., cryogelation, freeze-drying, sol-gel, phase inversion, and extraction of a porogen agent. Each approach is described in detail with examples related to the preparation of chitosan materials. The influence of the fabrication method on the structure of the obtained material is also highlighted herein. Finally, we discuss the potential applications of the considered materials.

The Functional and Application Possibilities of Starch/Chitosan Polymer Composites Modified by Graphene Oxide

This study describes functional properties of bionanocomposites consisting of starch/chitosan/graphene oxide (GO) obtained using the green synthesis method, such as water-barrier and optical properties, as well as the rate of degradation by enzymatic and acid hydrolysis. The toxicity of the composites and their effects on the development of pathogenic microflora during storage of meat food products was also investigated. Although the results showed that the barrier properties of the composites were weak, they were similar to those of biological systems. The studies carried out confirmed the good optical properties of the composites containing chitosan, which makes it possible to use them as active elements of packaging. The susceptibility of starch and chitosan films to enzymatic and acid hydrolyses indicates their relatively high biodegradability. The lack of toxicity and the high barrier against many microorganisms offer great potential for applications in the food industry.

Natural Polymers and Their Nanocomposites Used for Environmental Applications

The aim of this review is to bring together the main natural polymer applications for environmental remediation, as a class of nexus materials with advanced properties that offer the opportunity of integration in single or simultaneous decontamination processes. By identifying the main natural polymers derived from agro-industrial sources or monomers converted by biotechnology into sustainable polymers, the paper offers the main performances identified in the literature for: (i) the treatment of water contaminated with heavy metals and emerging pollutants such as dyes and organics, (ii) the decontamination and remediation of soils, and (iii) the reduction in the number of suspended solids of a particulate matter (PM) type in the atmosphere. Because nanotechnology offers new horizons in materials science, nanocomposite tunable polymers are also studied and presented as promising materials in the context of developing sustainable and integrated products in society to ensure quality of life. As a class of future smart materials, the natural polymers and their nanocomposites are obtained from renewable resources, which are inexpensive materials with high surface area, porosity, and high adsorption properties due to their various functional groups. The information gathered in this review paper is based on the publications in the field from the last two decades. The future perspectives of these fascinating materials should take into account the scale-up, the toxicity of nanoparticles, and the competition with food production, as well as the environmental regulations.

Stabilization of Pb, Cd, and Zn in soil by modified-zeolite: Mechanisms and evaluation of effectiveness

As a type of soil stabilization material, zeolite has good cation exchange ability and synchronous stabilization potential for multiple active heavy metal cations in soil. However, natural zeolite contains relatively high amounts of impurities, and has a single heavy metal stabilization mechanism, which limits its capacity to stabilize heavy metals in soil. To develop a stabilization material that could efficiently stabilize several heavy metals simultaneously, in the present study, modified zeolite (MZEO) was prepared via NaCl pretreatment, chitosan modification, modified chitosan loading, and CaSiO₃ modification to enable Pb, Cd, and Zn stabilization in soil. The aim of the present study was to explore zeolite modification technologies, reveal the stabilization mechanism of polymetallic contaminated soil and evaluate the stabilization effects of MZEO. According to the results, the modification treatment increased the cation exchange capacity of MZEO nearly 8-fold, the specific surface area 3.4-fold, and its internal pore structure was richer, with more adsorption sites. The appearance of a -NH₂ absorption bands confirmed the loading of chitosan successfully, and the modification enhanced the heavy metal stabilization mechanism. Upon the addition of MZEO to Baiyin soil, the chemical morphologies of heavy metals changed, which reduced the weak acid extracted forms of Pb, Cd, and Zn in the soil by 21%, 10%, and 19%, respectively. The potential mechanisms of free heavy metal reduction were ion exchange with Na in MZEO, heavy metal mineral formation by Al replacement in the crystal lattice, and bonding with SiO₃^2- formed by the hydrolysis of MZEO-loaded synaptic CaSiO₃ particles, to form silicate precipitation. MZEO application minimized heavy metal leaching risk in the soil and heavy metal biological/plant accessibility, with potential economic benefits. MZEO has promising applications in polluted soil remediation.

Color removal from wastewater using a synthetic high-performance antifouling GO-CPTMS@Pd-TKHPP/polyether sulfone nanofiltration membrane

Modified graphene oxide with 5,10,15,20-tetrakis-(4-hexyloxyphenyl)-porphyrin and palladium (II) (signified by GO-CPTMS@Pd-TKHPP) prepared as a novel antifouling polyether sulfone (PES) blended nanofiller membrane. The membrane efficiency has been analyzed such as pure water flux (PWF), hydrophilicity, and antifouling features. By increasing of modified graphene oxide percentage from 0 to 0.1 wt.% in the polymer matrix, the PWF was incremented from 14.35 to 37.33 kg/m2·h at 4 bar. The membrane flux recovery ratio (FRR) has been investigated by applying powdered milk solution; the FRR results indicated that the 0.1 wt.%-modified graphene oxide membrane showed a positive effect on fouling behavior with Rir and FRR value 8.24% and 91.76%, respectively. The nanofiltration membrane performance was assessed applying the Direct Red 16 dye rejection. It was demonstrated that the optimal membranes (0.1 wt.%-modified graphene oxide) had notable dye removal (99.58% rejection). The results are also verified by measuring the scanning electron microscopy (SEM), water contact angle (WCA), and atomic microscopy analysis (AFM).

Chitosan Biocomposites for the Adsorption and Release of H2S

The search for H₂S donors has been increasing due to the multiple therapeutic effects of the gas. However, the use of nanoporous materials has not been investigated despite their potential. Zeolites and activated carbons are known as good gas adsorbents and their modification with chitosan may increase the material biocompatibility and simultaneously its release time in aqueous solution, thus making them good H₂S donors. Herein, we modified with chitosan a series of A zeolites (3A, 4A and 5A) with different pore sizes and an activated carbon obtained from glycerin. The amount of H₂S adsorbed was evaluated by a volumetric method and their release capacity in aqueous solution was measured. These studies aimed to verify which of the materials had appropriate H₂S adsorption/release properties to be considered a potential H₂S donor. Additionally, cytotoxicity assays using HeLa cells were performed. Considering the obtained results, the chitosan composite with the A zeolite with the larger pore opening was the most promising material to be used as a H₂S donor so a further cytotoxicity assay using H₂S loaded was conducted and no toxicity was observed.

In situ growth zeolite imidazole framework materials on chitosan for greatly enhanced antibacterial effect

Zeolite imidazole framework materials (ZIFs) are a new type of antibacterial material with high chemical and thermal stability, and good antibacterial effect. However, powder ZIFs materials have the disadvantages of difficult separation and easy aggregation, which limit their application. In this work, ZIFs and chitosan (CS) were compounded by in-situ growth method to prepare a new antibacterial agent. The synergism of CS and ZIFs can effectively promote antibacterial effect compared with CS and pristine ZIFs, and CS/ZIF-67(1:6) has the best antibacterial activity, and its inhibitory rate (in 15 h) of E. coli is 96.75%, and the inhibitory rate of S. aureus reaches as high as 100%. This composites can effectively cause bacterial cell membrane rupture and leakage of internal nucleic acid and protein, leads to achieve antibacterial effect, and also exhibit excellent long-term (at least 5 days) antibacterial properties, the leaching of cobalt is below than 0.5 mg·L^-1, and this composites are with excellent bio-compatibility.

Injectable Cell-Laden Hydrogels for Tissue Engineering: Recent Advances and Future Opportunities

Tissue engineering intends to create functionalized tissues/organs for regenerating the injured parts of the body using cells and scaffolds. A scaffold as a supporting substrate affects the cells' fate and behavior, including growth, proliferation, migration, and differentiation. Hydrogel as a biomimetic scaffold plays an important role in cellular behaviors and tissue repair, providing a microenvironment close to the extracellular matrix with adjustable mechanical and chemical features that can provide sufficient nutrients and oxygen. To enhance the hydrogel performance and compatibility with native niche, the cell-laden hydrogel is an attractive choice to mimic the function of the targeted tissue. Injectable hydrogels, due to the injectability, are ideal options for in vivo minimally invasive treatment. Cell-laden injectable hydrogels can be utilized for tissue regeneration in a noninvasive way. This article reviews the recent advances and future opportunities of cell-laden injectable hydrogels and their functions in tissue engineering. It is expected that this strategy allows medical scientists to develop a minimally invasive method for tissue regeneration in clinical settings. Impact statement Cell-laden hydrogels have been vastly utilized in biomedical application, especially tissue engineering. It is expected that this upcoming review article will be a motivation for the community. Although this strategy is still in its early stages, this concept is so alluring that it has attracted all scientists in the community and specialists at academic health centers. Certainly, this approach requires more development, and a bunch of crucial challenges have yet to be solved. In this review, we discuss this various aspects of this approach, the questions that must be answered, the expectations associated with it, and rational restrictions to develop injectable cell-laden hydrogels.

Tailoring Chitosan/LTA Zeolite Hybrid Aerogels for Anionic and Cationic Dye Adsorption

Chitosan (CS) is largely employed in environmental applications as an adsorbent of anionic dyes, due to the presence in its chemical structure of amine groups that, if protonated, act as adsorbing sites for negatively charged molecules. Efficient adsorption of both cationic and anionic dyes is thus not achievable with a pristine chitosan adsorbent, but it requires the combination of two or more components. Here, we show that simultaneous adsorption of cationic and anionic dyes can be obtained by embedding Linde Type A (LTA) zeolite particles in a crosslinked CS-based aerogel. In order to optimize dye removal ability of the hybrid aerogel, we target the crosslinker concentration so that crosslinking is mainly activated during the thermal treatment after the fast freezing of the CS/LTA mixture. The adsorption of isotherms is obtained for different CS/LTA weight ratios and for different types of anionic and cationic dyes. Irrespective of the formulation, the Langmuir model was found to accurately describe the adsorption isotherms. The optimal tradeoff in the adsorption behavior was obtained with the CS/LTA aerogel (1:1 weight ratio), for which the maximum uptake of indigo carmine (anionic dye) and rhodamine 6G (cationic dye) is 103 and 43 mg g⁻¹, respectively. The behavior observed for the adsorption capacity and energy cannot be rationalized as a pure superposition of the two components, but suggests that reciprocal steric effects, chemical heterogeneity, and molecular interactions between CS and LTA zeolite particles play an important role.

Electrolytic transesterification of waste frying oil using Na+/zeolite-chitosan biocomposite for biodiesel production

Given the economic and environmental advantages of using Waste Fried Oil (WFO) as a starting material, this investigation explores the conversion of WFO to Fatty Acid Methyl Ester (FAME) via electrolysis for use in waste. In electrolysis, hydroxyl ions are generated from water in close proximity to the cathode. When hydroxyl ions react with methanol, they produce a species of nucleophilic methoxide which is the main actor in converting WFO into FAME. This study specifically investigates the effects of voltage, catalyst concentration, co solvent amount, rotation speed, and molar ratio of methanol to WFO in electrolytic transesterification converting WFO into FAME using graphite electrodes in the presence of a heterogeneous, catalytic zeolite-chitosan composite. With an alcohol to WFO molar ratio of 8:1, 1 wt% zeolite-chitosan composite concentration at 40 V in the presence of 2 wt% H₂O of the whole solution at room temperature and stirrer rate of 400 rpm and reaction time of 30 min, a 96.5% yield of FAME was achieved. Characterization of physical and biodiesel fuel properties was performed using American Society for Testing and Materials (ASTM) methods. The biocomposite was characterized using Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Transmission Electron Microscopy(TEM), Brunauer Emmett Teller(BET), Thermogravimetric analysis (TG), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectrometry (EDX). Finally, the physical properties of FAME produced under optimal conditions were studied using Gas Chromatography-Mass Spectrometry (GC-MS), FTIR, surface tension, and viscosity.

Chitosan-based blends for biomedical applications

Polysaccharides are the most abundant naturally available carbohydrate polymers; composed of monosaccharide units covalently connected together. Chitosan is the most widely used polysaccharides because of its exceptional biocompatibility, mucoadhesion, and chemical versatility. However, it suffers from a few drawbacks, e.g. poor mechanical properties and antibacterial activity for biomedical applications. Blending chitosan with natural or synthetic polymers may not merely improve its physicochemical and mechanical properties, but may also improve its bioactivity-induced properties. This review paper summarizes progress in chitosan blends with biodegradable polymers and polysaccharides and their biomedical applications. Blends of chitosan with alginate, starch, cellulose, pectin and dextran and their applications were particularly addressed. The critical and challenging aspects as well as the future ahead of the use of chitosan-based blends were eventually enlightened.

An Overview and Evaluation of Highly Porous Adsorbent Materials for Polycyclic Aromatic Hydrocarbons and Phenols Removal from Wastewater

Polycyclic aromatic hydrocarbons (PAHs) and phenolic compounds had been widely recognized as priority organic pollutants in wastewater with toxic effects on both plants and animals. Thus, the remediation of these pollutants has been an active area of research in the field of environmental science and engineering. This review highlighted the advantage of adsorption technology in the removal of PAHs and phenols in wastewater. The literature presented on the applications of various porous carbon materials such as biochar, activated carbon (AC), carbon nanotubes (CNTs), and graphene as potential adsorbents for these pollutants has been critically reviewed and analyzed. Under similar conditions, the use of porous polymers such as Chitosan and molecularly imprinted polymers (MIPs) have been well presented. The high adsorption capacities of advanced porous materials such as mesoporous silica and metal-organic frameworks have been considered and evaluated. The preference of these materials, higher adsorption efficiencies, mechanism of adsorptions, and possible challenges have been discussed. Recommendations have been proposed for commercialization, pilot, and industrial-scale applications of the studied adsorbents towards persistent organic pollutants (POPs) removal from wastewater.

Recent Advances of Chitosan-Based Injectable Hydrogels for Bone and Dental Tissue Regeneration

Traditional strategies of bone repair include autografts, allografts and surgical reconstructions, but they may bring about potential hazard of donor site morbidity, rejection, risk of disease transmission and repetitive surgery. Bone tissue engineering (BTE) is a multidisciplinary field that offers promising substitutes in biopharmaceutical applications, and chitosan (CS)-based bone reconstructions can be a potential candidate in regenerative tissue fields owing to its low immunogenicity, biodegradability, bioresorbable features, low-cost and economic nature. Formulations of CS-based injectable hydrogels with thermo/pH-response are advantageous in terms of their high-water imbibing capability, minimal invasiveness, porous networks, and ability to mold perfectly into an irregular defect. Additionally, CS combined with other naturally-derived or synthetic polymers and bioactive agents has proven to be an effective alternative to autologous bone and dental grafts. In this review, we will highlight the current progress in the development of preparation methods, physicochemical properties and applications of CS-based injectable hydrogels and their perspectives in bone and dental regeneration. We believe this review is intended as starting point and inspiration for future research effort to develop the next generation of tissue-engineering scaffold materials.

Poloxamer: A versatile tri-block copolymer for biomedical applications

Poloxamers, also called Pluronic, belong to a unique class of synthetic tri-block copolymers containing central hydrophobic chains of poly(propylene oxide) sandwiched between two hydrophilic chains of poly(ethylene oxide). Some chemical characteristics of poloxamers such as temperature-dependent self-assembly and thermo-reversible behavior along with biocompatibility and physiochemical properties make poloxamer-based biomaterials promising candidates for biomedical application such as tissue engineering and drug delivery. The microstructure, bioactivity, and mechanical properties of poloxamers can be tailored to mimic the behavior of various types of tissues. Moreover, their amphiphilic nature and the potential to self-assemble into the micelles make them promising drug carriers with the ability to improve the drug availability to make cancer cells more vulnerable to drugs. Poloxamers are also used for the modification of hydrophobic tissue-engineered constructs. This article collects the recent advances in design and application of poloxamer-based biomaterials in tissue engineering, drug/gene delivery, theranostic devices, and bioinks for 3D printing. STATEMENT OF SIGNIFICANCE: Poloxamers, also called Pluronic, belong to a unique class of synthetic tri-block copolymers containing central hydrophobic chains of poly(propylene oxide) sandwiched between two hydrophilic chains of poly(ethylene oxide). The microstructure, bioactivity, and mechanical properties of poloxamers can be tailored to mimic the behavior of various types of tissues. Moreover, their amphiphilic nature and the potential to self-assemble into the micelles make them promising drug carriers with the ability to improve the drug availability to make cancer cells more vulnerable to drugs. However, no reports have systematically reviewed the critical role of poloxamer for biomedical applications. Research on poloxamers is growing today opening new scenarios that expand the potential of these biomaterials from "traditional" treatments to a new era of tissue engineering. To the best of our knowledge, this is the first review article in which such issue is systematically reviewed and critically discussed in the light of the existing literature.

Zeolite in tissue engineering: Opportunities and challenges

Tissue engineering and regenerative medicine follow a multidisciplinary attitude to the expansion and application of new materials for the treatment of different tissue defects. Typically, proper tissue regeneration is accomplished through concurrent biocompatibility and positive cellular activity. This can be resulted by the smart selection of platforms among bewildering arrays of structural possibilities with various porosity properties (ie, pore size, pore connectivity, etc). Among diverse porous structures, zeolite is known as a microporous tectosilicate that can potentially provide a biological microenvironment in tissue engineering applications. In addition, zeolite has been particularly appeared promising in wound dressing and bone‐ and tooth‐oriented scaffolds. The wide range of composition and hierarchical pore structure renders the zeolitic materials a unique character, particularly, for tissue engineering purposes. Despite such unique features, research on zeolitic platforms for tissue engineering has not been classically presented. In this review, we overview, classify, and categorize zeolitic platforms employed in biological and tissue engineering applications.

Copper-enriched diamond-like carbon coatings promote regeneration at the bone-implant interface

There have been several attempts to design innovative biomaterials as surface coatings to enhance the biological performance of biomedical implants. The objective of this study was to design multifunctional Cu/a-C:H thin coating depositing on the Ti-6Al-4V alloy (TC4) via magnetron sputtering in the presence of Ar and CH4 for applications in bone implants. Moreover, the impact of Cu amount and sp2/sp3 ratio on the interior stress, corrosion behavior, mechanical properties, and tribological performance and biocompatibility of the resulting biomaterial was discussed. X-ray photoelectron spectroscopy (XPS) revealed that the sp2/sp3 portion of the coating was enhanced for samples having higher Cu contents. The intensity of the interior stress of the Cu/a-C:H thin bio-films decreased by increase of Cu content as well as the sp2/sp3 ratio. By contrast, the values of Young's modulus, the H3/E2 ratio, and hardness exhibited no significant difference with enhancing Cu content and sp2/sp3 ratio. However, there was an optimum Cu content (36.8 wt.%) and sp2/sp3 ratio (4.7) that it is feasible to get Cu/a-C:H coating with higher hardness and tribological properties. Electrochemical impedance spectroscopy test results depicted significant improvement of Ti-6Al-4V alloy corrosion resistance by deposition of Cu/a-C:H thin coating at an optimum Ar/CH4 ratio. Furthermore, Cu/a-C:H thin coating with higher Cu contents showed better antibacterial properties and higher angiogenesis and osteogenesis activities. The coated samples inhibited the growth of bacteria as compared to the uncoated sample (p < 0.05). In addition, such coating composition can stimulate angiogenesis, osteogenesis and control host response, thereby increasing the success rate of implants. Moreover, Cu/a-C:H thin films encouraged development of blood vessels on the surface of titanium alloy when the density of grown blood vessels was increased with enhancing the Cu amount of the films. It is speculated that such coating can be a promising candidate for enhancing the osseointegration features.