Natural Polymeric Materials Research Articles

Composite or Modified Hydroxyapatite Microspheres as Drug Delivery Carrier for Bone and Tooth Tissue Engineering.

Since hydroxyapatite (HAp) is an important constituent of bone and teeth, it has excellent biocompatibility and bioactivity, good osteoconductive effects and the ability to induce bone formation as a material for bone or tooth repair and replacement. At present, widely used HAp microspheres have some characteristics, such as large specific surface area, light mass, good injection properties, good fluidity, and low aggregation ability, but they are difficult to really meet the biological and clinical needs due to their own mechanical property defects, such as low strength, brittleness, and poor plasticity. Based on the current research status of HAp microspheres, we summarize the research progress of various types of composite microspheres, including inorganic materials, natural polymer materials and synthetic polymer materials, and further analyze the advantages of HAp composite microspheres loaded with drug molecules, proteins and bioactive factors, so as to explore the development prospect of HAp composite microspheres as scaffolds for constructing sustained release systems. It provides a theoretical basis and research direction to prepare HAp composite micro-spheres with superior comprehensive properties so that they can be better applied in bone tissue regeneration and tooth regeneration engineering.

Unravelling the role of microwave absorber in color stripping of a dyed natural polymeric material with microwave assisted method

Unravelling the role of microwave absorber in color stripping of a dyed natural polymeric material with microwave assisted method

Application of Gaba-Gaba Egg Rack Bio-Composite as Material Wall Meeting Room Acoustics

Bio composite materials are a combination of two or more natural polymer materials or biofiber (natural fibers) which can be degraded as reinforcement and polymer or matrix. Natural fibers generally have the ability to absorb sound well and have basic properties as composite reinforcements. If a wave hits a material, the wave can be straightened, reflected and absorbed. The ability of composite structures to absorb sound can be used to reduce noise levels. This research models a combination of egg rack waste mixed with sago leaf stem (gaba-gaba) waste as a bio-composite material for room acoustic panels. This research uses a material modeling engineering method which is a pure experiment, with the stages of making test samples based on fixed variables and measurable variables and then testing to obtain the material absorption coefficient, then the test results are based on the specified variables, then applying the material to the meeting room. After that tested the acoustic level of the room, especially the meeting room.

Trends in the Incorporation of Antiseptics into Natural Polymer-Based Nanofibrous Mats.

Nanofibrous materials represent a very promising form of advanced carrier systems that can be used industrially, especially in regenerative medicine as highly functional bandages, or advanced wound dressings. By incorporation of antimicrobial additives directly into the structure of the nanofiber carrier, the functionality of the layer is upgraded, depending on the final requirement-bactericidal, bacteriostatic, antiseptic, or a generally antimicrobial effect. Such highly functional nanofibrous layers can be prepared mostly by electrospinning technology from both synthetic and natural polymers. The presence of a natural polymer in the composition is very advantageous. Especially in medical applications where, due to the presence of the material close to the human body, the healing process is more efficient and without the occurrence of an unwanted inflammatory response. However, converting natural polymers into nanofibrous form, with a homogeneously distributed and stable additive, is a great challenge. Thus, a combination of natural and synthetic materials is often used. This review clearly summarizes the issue of the incorporation and effectiveness of different types of antimicrobial substances, such as nanoparticles, antibiotics, common antiseptics, or substances of natural origin, into electrospun nanofibrous layers made of mostly natural polymer materials. A section describing the problematic aspects of antimicrobial polymers is also included.

Constructing a “micro-nano collaboration” network via disk-milling: Value-enhanced utilization of flexible temperature-resistant cellulose insulation films

Cellulose is a sustainable natural polymer material that has found widespread application in transformers and other power equipment because of its excellent electrical and mechanical performance. However, the utility of cellulose materials has been limited by the challenge of balancing heat resistance with flexibility. On the basis of the preliminary research conducted by the research team, further proposals have been put forward for a method involving disk milling to create a “micro–nanocollaboration” network for the fabrication of flexible, high-temperature-resistant, and ultrafine fiber-based cellulose insulating films. The resulting full-component cellulose films exhibited impressive properties, including high tensile strength (22 MPa), flexibility (92–263 mN), remarkable electrical breakdown strength (39 KV/mm), and volume resistivity that meets the standards for insulation materials (4.92 × 1011 Ω·m). These results demonstrate that the proposed method can produce full-component cellulose insulation films that offer both exceptional flexibility and high-temperature resistance.

Hygroscopy as an Indicator of Specific Surface Area in Polymer Materials.

Specific surface area (SSA) is an integral characteristic of the interfacial surface in poly-disperse systems, widely used for the assessment of technological properties in polymer materials and composites. Hygroscopic water content (Wh) is an obligate indicator of dispersed materials prior to any analysis of their chemical composition. This study links both indicators for the purpose of the express assessment of SSA using widely available Wh data, on the example of natural (starch, cellulose) and synthetic (acrylic hydrogels) polymer materials. The standard BET analysis of SSA using water vapor desorption was chosen as a reference method. In contrast to the known empirical correlations, this study is based on the fundamental thermodynamic theory of the disjoining water pressure for the connection of the analyzed quantities. The statistical processing of the results for the new methodology and the standard BET method showed their good compliance in a wide range of SSA from 200 to 900 m2/g. The most important methodological conclusion is the possibility of an accurate physically based calculation of hydrophilic SSA in polymer materials using their Wh data at a known relative humidity in the laboratory.

Biodegradability Study of Modified Chitosan Films with Cinnamic Acid and Ellagic Acid in Soil.

Currently, natural polymer materials with bactericidal properties are extremely popular. Unfortunately, although the biopolymer material itself is biodegradable, its enrichment with bactericidal compounds may affect the efficiency of biodegradation by natural soil microflora. Therefore, the primary objective of this study was to evaluate the utility of fungi belonging to the genus Trichoderma in facilitating the degradation of chitosan film modified with cinnamic acid and ellagic acid in the soil environment. Only two strains (T.07 and T.14) used chitosan films as a source of carbon and nitrogen. However, their respiratory activity decreased with the addition of tested phenolic acids, especially cinnamic acid. Addition of Trichoderma isolates to the soil increased oxygen consumption during the biodegradation process compared with native microorganisms, especially after application of the T.07 and T.14 consortium. Isolates T.07 and T.14 showed high lipolytic (55.78 U/h and 62.21 U/h) and chitinase (43.03 U/h and 41.27 U/h) activities. Chitinase activity after incorporation of the materials into the soil was higher for samples enriched with T.07, T.14 and the consortium. The isolates were classified as Trichoderma sp. and Trichoderma koningii. Considering the outcomes derived from our findings, it is our contention that the application of Trichoderma isolates holds promise for expediting the degradation process of chitosan materials containing bactericidal compounds.

Novel melanin-derived stationary phase for immobilized metal ion affinity chromatography in recombinant His-tagged protein purification

The matrix of the stationary phase is a crucial element in affinity chromatography for protein purification. Various materials, including polymer or magnetic materials, have been employed as the matrix in the purification of His-tagged protein. Here, for the first time, we utilized a combination of melanin and alginate, both natural polymer materials, to synthesize Ni-melanin/alginate (Ni-M/A) beads for His-tagged protein purification. We investigated the binding of His-tagged Mpro on the Ni-M/A beads, referred to as Ni-M/A-Mpro, and assessed the elution efficiency of Mpro from the beads. Our examination involved FTIR, EDS, XRD, SDS-PAGE, and Western blotting methods. FTIR spectra revealed notable changes in the stretching patterns and intensities of hydroxyl, amine, carbonyl, imine and amide chemical groups, when Mpro protein was present in the Ni-M/A sample. XRD spectra demonstrated the occurrence of two Nickel peaks at 35–40 deg and 40–45 deg in Ni-M/A, but only one nickel peak at 35–40 deg in Ni-M/A-Mpro, indicating the binding of Mpro on the Nickel ions. EDS analysis reported a decrease in the concentration of Nickel on the surface of Ni-M/A from 16% to 7% when Mpro protein was loaded into the stationary phase. Importantly, our data indicated that the purity of the His-tagged protein Mpro after purification reached 97% after just one-step purification using the Ni-M/A stationary phase. Moreover, the binding capacity of Ni-M/A for Mpro was approximately 5.2 mg/g with recovery efficiency of 40%. Our results suggested Ni-M/A as a highly potential solid phase for affinity chromatography in the purification of His-tagged protein.

Clay minerals/sodium alginate/polyethylene hydrogel adsorbents control the selective adsorption and reduction of uranium: Experimental optimization and Monte Carlo simulation study

Clay minerals formations are potential geological barrier (host rocks) for the long-rerm storage of uranium tailing in deep geological repositories. However, there are still obstacles to the efficient retardation of uranium because of the competition between negatively charged regions at the clay minerals end face, surface and between layers, as well as low mineralization capacity. Herein, employing a simple method, we used sodium alginate (SA), an inexpensive natural polymer material, polyethylene (PE), and the natural clay minerals montmorillonite (Mt), nontronite (Nt), and beidellite (Bd) to prepare three hydrogel adsorbents, (denoted as Mt/PE-@SA, Nt/PE-@SA, and Bd/PE-@SA), respectively. The application of obtained hydrogel adsorbents further extends to uranium(VI) removal from aqueous. Due to the synergistic action of SA group and PE group, hydrogel adsorbents showed select adsorption and mineralization effect on uranium(VI), among which the maximum uranium(VI) adsorption capacity of Nt/PE-@SA was 133.3 mg·g-1 and Mt/PE-@SA exhibited strong selectivity for uranium(VI) in the presence of coexisting metal ions. Cyclic voltammetry studies indicated the mitigation and immobilization of uranium species onto adsorbents by both reduction and mineralization. Besides, the synergistic adsorption of SA and PE on clay minerals was hypothesized, and the idea was supported by structure optimizations results from Monte Carlo dynamics simulation (MCD). Three obtained hydrogel adsorbents structural model was constructed based on its physicochemical characterization, the low energy adsorption sites and adsorption energies are investigated using MCD simulation. The simulation results show that obtained hydrogel adsorbents have a strong interaction with uranium(VI), which ensures the high adsorption capacity of those materials. Most importantly, this work demonstrates a new strategy for preparing mineral-based hydrogel adsorbents with enough stability and provides a new perspective for uranium(VI) removal in complex environment.

Construction of gelatin/alginate hydrogels doped hemicyanine derivatives for photodynamic antibacterial application

Hydrogel systems based on natural polymer materials have provided alternative opportunities for preparing antimicrobial dressings. A composite antibacterial hydrogel system containing gelatin (Gel), alginate (Alg) and hemicyanine derivatives with different chain lengths (C3, C6 and C10) was constructed. The composite hydrogels have excellent swelling ability and low degradability due to the classical three-dimensional network structure. Because of the photosensitization ability of C3, C6 and C10, hydrogels containing these molecules can also effectively produce reactive oxygen species (ROS) under light. Importantly, the hydrogel containing C3 molecules that have higher spatial extension structure and shorter alkyl chain than C6 and C10 shows better photo-responsive antibacterial effect against drug-resistant Escherichia coli. The bacterial killing activity of the composite hydrogel system could be regulated by changing the alkyl chain length of the photosensitizers. This effective and photo-responsive composite hydrogel system is expected to be used for bacteria-infected wound repair and promoting wound healing.

Recent advances in injectable hydrogel therapies for periodontitis.

Periodontitis is an immune-inflammatory disease caused by dental plaque, and deteriorates the periodontal ligament, causes alveolar bone loss, and may lead to tooth loss. To treat periodontitis, antibacterial and anti-inflammation approaches are required to reduce bone loss. Thus, appropriate drug administration methods are significant. Due to their "syringeability", biocompatibility, and convenience, injectable hydrogels and associated methods have been extensively studied and used for periodontitis therapy. Such hydrogels are made from natural and synthetic polymer materials using physical and/or chemical cross-linking approaches. Interestingly, some injectable hydrogels are stimuli-responsive hydrogels, which respond to the local microenvironment and form hydrogels that release drugs. Therefore, as injectable hydrogels are different and highly varied, we systematically reviewed the periodontal treatment field from three perspectives: raw material sources, cross-linking methods, and stimuli-responsive methods. We then discussed current challenges and opportunities for the translation of hydrogels to clinic, which may guide further injectable hydrogel designs for periodontitis.

Biopolymeric Materials in the Management of Diabetic Wound Healing: A Comprehensive Review

The compromised wound healing observed in diabetic patients poses significant hurdles, escalating the risk of infections. The growing interest in natural polymeric materials is fueled by their abundant availability, cost-effectiveness, and eco-friendly attributes. Advances in polymer science have expanded the applications, especially in tissue engineering and regenerative medicine. These interdisciplinary fields integrate knowledge and technology from diverse domains to restore damaged tissues and organs in medical interventions. Polymers function as versatile tools, serving as carriers for drugs and cells and facilitating host-cell integration to meet the requisites of regeneration and repair. This intricate process involves multiple stages, necessitating the development of various components to construct the desired neo-tissue or organ. Diverse biopolymers, encompassing biological, synthetic, and hybrid varieties, find extensive utility across various medical applications. Their tunable physical, chemical, and biological properties render them ideal for tailoring to specific application requirements. This review provides a comprehensive overview of the wound-healing process, with a specific focus on the challenges presented by diabetic wounds. Additionally, it explores various biopolymers, including alginate, gelatin, cellulose, silk sericin, chondroitin sulfate, chitosan, xanthan gum, cyclodextrin, and hyaluronic acid, elucidating their roles in the management of diabetic wounds.

Helianthus Annuus L. Comparison Of The Properties Of Fibers Obtained From The Plant By Methods of Decortication And Retting

A large amount of sunflower production is carried out in our country. The 2,500,000 tons of sunflower stalks that appeared after production pose a problem for our farmer. In order to clean up this environmental problem from the field, sunflower stalks are destroyed by burning to warm up in winter, broken down and mixed into the soil, or burned after harvesting. It is thought that by obtaining qualified, ecological and naturally decomposing sunflower fiber from the stem of the sunflower plant, which is an agricultural waste, it can increase the added value of agricultural products and contribute to the protection of the environment. In this study, the anatomical characteristics of the stem of the sunflower plant were determined, and natural lignocellulosic fibers were obtained from the sunflower stem by retting and decortication methods (fresh stem, dried stem). Various physical, chemical and mechanical properties of these fibers have been measured. For this purpose, FTIR (Fourier Transform Infrared Spectroscopy) analysis, XRD (X-Ray Diffractometer) analysis and SEM (Scanning Electron Microscope) analysis were applied to the fibers obtained by different methods. Thermal analyses were performed by TG-DTA (Thermogravimetric) analysis. In addition, fiber strength, fiber fineness, fiber length and color measurements were made. The chemical content of the obtained fibers (pectin, lignin, cellulose, hemicellulose) was determined. The properties of the fibers were compared using the obtained data. As a result of the study, it has been seen that the characteristic properties of the sunflower fibers obtained by the retting method are better. It has been determined that the elemental, thermal and crystal structures of the fibers obtained by different methods are similar. It was concluded that sunflower fiber will not be spun as a yarn, but can be used as a natural polymeric composite reinforcement material.

High-performance electrochromic device based on poly acrylamide gel polymer electrolyte containing hypromellose

Cellulose is one of the most widely distributed and abundant natural polymer material. Hypromellose (HPMC), a cellulose derivative, has received much attention in recent years in the field of electrolytes because of its biodegradability, high transparency, excellent water solubility and biocompatibility. In this work, poly acrylamide (PAM)-based hydrogel electrolytes with high ionic conductivity (5.3 × 10−2 S cm−1) and high transmittance (95.8% at 672 nm) were prepared by thermocuring AM monomer containing a certain amount of HPMC. We assembled an electrochromic device (ECD) based on this gel polymer electrolyte (GPE) with Prussian blue (PB) film and WO3·xH2O film. The ECD enables color switching between colorless and blue states. The optical modulation at 672 nm is 73.2% and the coloration efficiency is 154.7 cm2⋅C−1. The coloration time and bleaching time are 2.5 and 3.1 s, respectively. In addition, the optical modulation of the ECD remains 93.7% of its initial value after 1,000 cycles, demonstrating a good cycling stability of the ECD, which should be attributed to the existence of large number of hydrogen bonds between PAM and HPMC.

An anti-freezing and anti-drying nanocellulose hydrogel for human motion detection

Flexible sensors based on biological hydrogels have gained significant attention in the fields of wearable devices, human-computer interaction robots, and medical monitoring. Nanocellulose, a natural polymer material, offers advantages such as low cost, abundant reserves, green environmental protection, and renewability. However, the high water content of the nanocellulose-based flexible sensor limits its application at low temperatures, making it difficult for the nanocellulose-based hydrogel electronic skin to function properly. To enhance the hydrogel's anti-freezing and anti-drying properties, we introduced glycerol (GL) into the in-situ grown polypyrrole (PPy) hydrogel of 2,2,6,6-Tetramethylpiperidine-1-oxyl radical (TEMPO) oxidized cellulose nanofibril (TOCN) and obtained the organic hydrogel TOCN/PPy/GL. The prepared TOCN/PPy/GL organic hydrogel maintains excellent electrical conductivity, mechanical properties, and strain sensing capabilities (strain sensitivity GF=2.41 at −45 ℃, response time 100 ms, recovery time 200 ms). The TOCN/PPy/GL organic hydrogel electronic skin also exhibited exceptional anti-drying property, with a volume retention of 66.75% after 24 h at 100 ℃, which is six times higher than the volume retention of TOCN/PPy hydrogel without GL under the same conditions.

A comparative study on the influence of fiber enzymatic treatment in thermal, morphological and mechanical properties of PBS matrix reinforced with different date palm fibers: Under accelerated UV radiation exposure

The use of natural fiber-reinforced polymer materials has become increasingly common in various applications. However, the performance and durability of these composites in outdoor applications are not fully understood. Therefore, the objective of this study is to investigate the impact of an artificial ultraviolet radiation on the degradation behavior of composites based on a Poly Butylene Succinate (PBS) matrix. The reinforcement materials used in this research were the trunk and palm fibers obtained from date palm trees. Specifically, the effect of modifying the fiber surface with an enzymatic treatment on the interfacial adhesion fiber/matrix as well as on the rate of deterioration of the resulted composites, under accelerated aging, was assessed. Changes in the composite’s thermal stability, surface morphology and mechanical properties were determined after aging. A sharp transition in the behavior of the PBS matrix was observed after UV exposure, shifting from slight ductility following 100 h to brittleness after 700 h. The aging process resulted in a decrease in the thermal stability of all composites. However, the composites containing treated fibers exhibited better thermal stability compared to those with untreated fibers. Additionally, the use of enzyme-treated fibers in the composites promoted greater stability in the mechanical properties even after aging. The reinforcement of the composites with palm fibers yielded better interfacial adhesion compared to the use of trunk fibers, and resulted in better retention in the tensile strength property after aging. The enzymatic treatment facilitated stronger physical attachment between the fibers and the matrix, preventing any fiber or interface degradation.

Environmentally friendly separators based on cellulose diacetate-based crosslinked networks for lithium-ion batteries

Biomass fibers are recognized as degradable and renewable green natural polymer materials. However, research on biomass fiber-based lithium battery separators is still relatively limited. Here, a kind of cellulose diacetate-based composite separator for lithium batteries was investigated via electrostatic spinning technology. In this study, M-CDA/PEO/BM composite separators were obtained by modifying fiber-based nonwovens through deacetylation, followed by an infiltration process and thermal cross-linking reaction to introduce boehmite (BM) and polyethylene oxide (PEO). Wherein the infiltrating solution is composed of polyethylene glycol diglycidyl ether (PEGDE), polyetheramine (DPPG), and boehmite particles. The results demonstrate that this nanofibre composite separator exhibits good heat tolerance (no shrinkage at 200 °C), excellent wettability (contact angles only 15.1°), and high ionic conductivity (2.83 mS cm−1) in electrolytes. Additionally, the cells utilizing the composite separator exhibited superior cycle performance and better multiplier performance (170 mAh·g−1 at 0.5C) compared to the polypropylene separator that is currently available in the market, under identical circumstances. This renewable composite possesses remarkable properties that position it as a highly promising option for lithium-ion battery separators with exceptional performance.

Antibacterial and antioxidant properties of phenolic acid grafted chitosan and its application in food preservation: A review.

Chitosan is a bio-renewable natural polymeric material. The antibacterial and antioxidant activity of chitosan can be enhanced by grafting with phenolic acids to further expand its application in food. Therefore, this paper focuses on reviewing the structure, antimicrobial and antioxidant activities and their mechanisms with phenolic acid-g-CS, evaluating its cytotoxicity, and describing its application in various food preservation. In general, different reaction mechanisms of phenolic acid-g-CS synthesis lead to different product structures. Compared to chitosan, phenolic acid-g-chitosan exhibited enhanced antibacterial and antioxidant activities. The toxicity assessment showed that phenolic acid-g-CS is not cytotoxic. Moreover, phenolic acid-g-CS has been applied to a variety of food products such as fruits, vegetables and meat with good results. Overall, this review provides a certain reference for subsequent researchers to design phenolic acid-g-CS more rationally and for the subsequent development of phenolic acid-g-CS in food preservation.

Analyzing Temperature Distribution Patterns on the Facing and Backside Surface: Investigating Combustion Performance of Flame-Retardant Particle Boards Using Aluminum Hypophosphite, Intumescent, and Magnesium Hydroxide Flame Retardants.

Particle boards are manufactured through a hot pressing process using wood materials (natural polymer materials) and adhesive, which find common usage in indoor decorative finishing materials. Flame-retardant particleboard, crucial for fire safety in such applications, undergoes performance analysis that includes assessing temperature distribution across its facing surface and temperature increase on the backside surface during facade combustion, yielding critical insights into fire scenario development. In this study, a compact flame spread apparatus is utilized to examine the flame retardancy and combustion behavior of particle boards, with a specific emphasis on the application of cost-effective flame retardants, encompassing aluminum hypophosphite (ALHP), an intumescent flame retardant (IFR) comprising ammonium polyphosphate (APP), melamine (MEL), and Dipentaerythritol (DPE), alongside magnesium hydroxide (MDH), and their associated combustion characteristics. The D300°C values, representing the vertical distance from the ignition point (IP) to P300°C (the temperature point at 300 °C farthest from IP), are measured using a compact temperature distribution measurement platform. For MDH/PB, APP + MEL + DPE/PB, and ALHP/PB samples, the respective D300°C values of 145.79 mm, 117.81 mm, and 118.57 mm indicate reductions of 11.11%, 28.17%, and 27.71%, compared to the untreated sample's value of 164.02 mm. The particle boards treated with ALHP, IFR, and MDH demonstrated distinct flame-retardant mechanisms. MDH/PB relied on the thermal decomposition of MDH to produce MgO and H2O for flame retardancy, while APP + MEL + DPE/PB achieved flame retardancy through a cross-linked structure with char expansion, polyphosphate, and pyrophosphate during combustion. On the other hand, ALHP/PB attained flame retardancy by reacting with wood materials and adhesives, forming a stable condensed P-N-C structure. This study serves as a performance reference for the production of cost-effective flame-resistant particleboards and offers a practical method for assessing its fire-resistant properties when used as a decorative finishing material on facades in real fire situations.

A new eco-friendly fluorescent microcapsules for effective and selective detection of Hg(II)&Cu(II)

The detection of heavy metals in wastewater with eco-friendly materials and sustainable processes is extremely important for the environment and human health. In this study, sporopollenin, which is a natural polymer material, was derivatized with an innovative macrocyclic compound, and then fluorescence property was acquired. Bodipy and Pillar[5]arene were used to prepare fluorescent microcapsules (Sp-P[5]-bodipy) based on organic compounds. The compounds used in the preparation of fluorescent microcapsules were synthesized by conventional procedures and characterized by several methods such as NMR, FT-R, mass spectroscopy, elemental analysis, and melting point. The characterization of the obtained surfaces was carried out with TGA, FT-IR and SEM device in the determination of the surface morphology and the functional groups. The target fluorescent microcapsules, Sp-P[5]-bodipy, were performed using fluorescence spectroscopy to detect metal ions in aqueous solutions that the modified surfaces encapsulated Hg(II) and Cu(II) ions, respectively. Moreover, some parameters such as pH, temperature, response time, limit of detection (LOD) and binding stoichiometry were examined for practical chemo-sensor applications that Sp-P[5]-bodipy have a low LOD for both Cu(II) (6.16 µM) and Hg(II) ions (3.42 µM).