Cellulose Beads Research Articles

Cellulose-based hydrogel beads: Preparation and characterization

Biopolymer-based hydrogel beads possessing intrinsic low-toxicity, biocompatibility and biodegradability have gained widespread utility in several applications. Among the biopolymers, cellulose is one of the most abundant renewable biomaterials. Herein cellulose hydrogel beads have been prepared by dissolving cellulose in 68% ZnCl2 solution and then crosslinking the polymer chains through calcium ions. The water and ethanol washing of the beads profoundly influences the beads architecture as characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray powder diffraction and Scanning electron microscopy. The total crystallinity index of the beads increases with the amount of calcium ions that is further enhanced by water washing. These beads, possessing a layer-like nanoporous structure, are capable of loading bovine serum albumin (BSA) and releasing in a sustained manner. The outcome promises a large-scale production of cellulose beads having the potential to be eco-friendly and inexpensive delivery carriers in food, pharmaceutical, medical and agriculture applications.

Study of tentacle-like cationic macroporous cellulose spherical adsorbent for heavy metals

The rational structure and functional ligands design are of great significance to prepare high-performance adsorbents in the application. Herein, macroporous cellulose beads derived from pine needles with tentacle-like functionalized ligands are developed for heavy metal ions adsorption. The macroporous structure is generated via templated assistance, which endows the beads with high permeability, and the kinetic experiments reveal the fast adsorption rate within 40 min. The glycidyl methacrylate (GMA) serve as monomers to fabricate tentacle-like polymer chains on the beads and then m0odified with iminodiacetic acid (IDA). The grafted polymers increase the ligand density of IDA, which provides more binding sites for heavy metal ions. As a result, the adsorption experiments indicate that the prepared adsorbent shows a high adsorption capacity of 300.12, 240.62, 216.41 mg/g for copper (II), manganese (II), and nickel (II), respectively, which confirm the high performance of the adsorbents. On the basis of these results, this work not only provides a promising candidate for the heavy metal ions treatment, but also expands an approach of high-value utilization of biomass.

Hollow cellulose-carbon nanotubes composite beads with aligned porous structure for fast methylene blue adsorption

Polysaccharide based beads with unique porous structure have gained considerable interests due to their specific adsorption behaviors and biodegradability. The purpose of this paper was to develop hollow cellulose/carbon nanotubes composite beads with aligned porous structure which have potential applications in fast adsorption field. The composite beads were fabricated by ice template and freeze-drying technology. Different characterizations have proved that the carbon nanotubes and magnetic nanoparticles have been incorporated into the cellulose beads. Higher concentration of carbon nanotubes and cellulose would result in a larger diameter of the composite beads. The composite beads can effectively adsorb the methylene blue (MB). The pseudo-second-order model and Langmuir isotherm were best fitted to the adsorption. The composite beads showed a fast adsorption behavior towards MB with a t1/2 of 1.07 min obtained from pseudo-second-order model. The maximum adsorption capacity was 285.71 mg g−1 at pH 7.0. The composite beads also showed good reusability and biodegradability. We anticipate that different polysaccharides based composite beads with aligned porous structure can be obtained through the similar methods and applied in adsorption fields.

Tentacle-type poly(hydroxamic acid)-modified macroporous cellulose beads: Synthesis, characterization, and application for heavy metal ions adsorption

Herein, a facile yet efficient template method to fabricate macroporous cellulose beads (MCBs) is reported. In this method, micro-size CaCO3 is utilized to create macroporous structure for fast mass transfer, and tentacle-type poly(hydroxamic acid) as adsorption ligand is immobilized on the MCBs to improve adsorption capacity. The obtained tentacle-type poly(hydroxamic acid)-modified MCMs (TP-CMCBs) show uniform spherical shape (about 80 μm), bimodal pore system (macropores≈3.0 μm; diffusional pores≈14.5 nm), and high specific surface area (52.7 m2/g). The adsorption performance of TP-CMCBs is evaluated by heavy metal ions adsorption. TP-CMCBs exhibit not only high adsorption capacities (342.5, 261.5 and 243.2 mg/g for Cu2+, Mn2+ and Ni2+, respectively.), but also fast adsorption rate (>70% of its equilibrium uptake within 30 min). Additionally, TP-CMCBs have excellent reusability, as evidenced by that the adsorption capacities have no obvious change even after five-time consecutive adsorption-desorption cycles. All results demonstrate that the proposed TP-CMCBs have great potential in removal of heavy metal ions.

Characterization and antibacterial properties of epsilon-poly- l-lysine grafted multi-functional cellulose beads

In recent years, harmful microorganisms in water pose great harm to ecological environment and human health. To solve this problem, epsilon-poly-l-lysine (EPL) grafted cellulose beads were prepared via 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) mediated oxidation and carbodiimide mediated cross-linking reaction. Hydroxyl groups on C6 of cellulose were oxidized to carboxyl groups by TEMPO and grafting reaction was achieved between newly formed carboxyl groups of cellulose and amino of EPL. The beads were characterized by FTIR, SEM, XRD and TGA. The crystalline form of cellulose transformed from cellulose I to cellulose II after being dissolved and regenerated. The grafted cellulose beads showed good antibacterial activities against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus and Alicyclobacillus acidoterrestris with 10 h. The beads could be biodegraded in soil after 28 days. It is expected that the bio-based composite beads could have potential applications in water purification and food treatment fields.

Production of Cellulose Beads with Tetraethylammonium Hydroxide-Urea Solvent and Dropping Technique : Effects of Concentration of Cellulose Solution

Production of Cellulose Beads with Tetraethylammonium Hydroxide-Urea Solvent and Dropping Technique : Effects of Concentration of Cellulose Solution

TEMPO-Oxidized Cellulose Beads as Potential pH-Responsive Carriers for Site-Specific Drug Delivery in the Gastrointestinal Tract.

The development of controlled drug delivery systems based on bio-renewable materials is an emerging strategy. In this work, a controlled drug delivery system based on mesoporous oxidized cellulose beads (OCBs) was successfully developed by a facile and green method. The introduction of the carboxyl groups mediated by the TEMPO(2,2,6,6-tetramethylpiperidine-1-oxyradical)/NaClO/NaClO2 system presents the pH-responsive ability to cellulose beads, which can retain the drug in beads at pH = 1.2 and release at pH = 7.0. The release rate can be controlled by simply adjusting the degree of oxidation to achieve drug release at different locations and periods. A higher degree of oxidation corresponds to a faster release rate, which is attributed to a higher degree of re-swelling and higher hydrophilicity of OCBs. The zero-order release kinetics of the model drugs from the OCBs suggested a constant drug release rate, which is conducive to maintaining blood drug concentration, reducing side effects and administration frequency. At the same time, the effects of different model drugs and different drug-loading solvents on the release behavior and the physical state of the drugs loaded in the beads were studied. In summary, the pH-responsive oxidized cellulose beads with good biocompatibility, low cost, and adjustable release rate have shown great potential in the field of controlled drug release.

Physical and nutrient stimuli differentially modulate gut motility patterns, gut transit rate, and transcriptome in an agastric fish, the ballan wrasse.

The effects of nutrient and mechanical sensing on gut motility and intestinal metabolism in lower vertebrates remains largely unknown. Here we present the transcriptome response to luminal stimulation by nutrients and an inert bolus on nutrient response pathways and also the response on gut motility in a stomachless fish with a short digestive tract; the ballan wrasse (Labrus berggylta). Using an in vitro model, we differentiate how signals initiated by physical stretch (cellulose and plastic beads) and nutrients (lipid and protein) modulate the gut evacuation rate, motility patterns and the transcriptome. Intestinal stretch generated by inert cellulose initiated a faster evacuation of digesta out of the anterior intestine compared to digestible protein and lipid. Stretch on the intestine upregulated genes associated with increased muscle activity, whereas nutrients stimulated increased expression of several neuropeptides and receptors which are directly involved in gut motility regulation. Although administration of protein and lipid resulted in similar bulbous evacuation times, differences in intestinal motility, transit between the segments and gene expression between the two were observed. Lipid induced increased frequency of ripples and standing contraction in the middle section of the intestine compared to the protein group. We suggest that this difference in motility was modulated by factors [prepronociceptin (pnoca), prodynorphin (pdyn) and neuromedin U (nmu), opioid neurotransmitters and peptides] that are known to inhibit gastrointestinal motility and were upregulated by protein and not lipid. Our findings show that physical pressure in the intestine initiate contractions propelling the bolus distally, directly towards the exit, whereas the stimuli from nutrients modulates the motility to prolong the residence time of digesta in the digestive tract for optimal digestion.

Carbazate functionalized cellulose beads as potential scavengers specific for carbonylated proteins

Scavenging carbonylated proteins that are toxic substances inducing various diseases attract the most attention in the field of blood purification. In our study, functionalized cellulose beads modified by carbazate groups as affinity ligands of carbonyls were prepared for specific scavenging of carbonylated proteins based on the carbazate-aldehyde/ ketone reaction. Results showed that the carbazate-functionalized cellulose beads with different degrees of substitution (DS) maintained the original multi-porous structure with the diameter of about 50 μm and thermal stability. Spectroscopic and gel electrophoresis analysis indicated that the modified cellulose beads could effectively scavenge carbonylated proteins and the scavenging effects increased with the increase of DS. Thus, the carbazate functionalized cellulose beads may be developed as fillers in the column for the scavenging of carbonylated proteins.

Single-step fabrication and environmental applications of activated carbon-containing porous cellulose beads

Activated carbon (AC)-containing porous cellulose beads (ACPBs) with a three-dimensionally interconnected porous structure and high impact strength were prepared in a single step from cellulose acetate and AC via a non-solvent-induced phase separation process at room temperature. The adsorption behavior of the ACPBs was evaluated using toluidine blue (TB) dye as a model adsorbate. The effects of initial dye concentration and contact time on the adsorption kinetics and isotherms of ACPBs were studied. The adsorption of TB by the ACPBs followed pseudo-second-order kinetics and could be expressed by the Langmuir adsorption isotherm model. ACPB adsorbed 119.1 mg/g of TB at an initial TB concentration of 101.0 mg/L and the Langmuir equation predicted that the maximum adsorption capacity of ACPBs for TB was 123.5 mg/g. ACPBs could retain original shape and around 85% of their adsorption capacity after three times recycle. Furthermore, ACPBs efficiently removed malodorous gases from gas mixtures, indicating potential for environmental applications including toxic dye and gas elimination.

Congo red adsorption with cellulose-graphene nanoplatelets beads by differential column batch reactor

Cellulose beads loaded with graphene nanoplatelets (GNP) were prepared by a physical gelation method, which was feasible under mild conditions. The phases spontaneously separate when the cellulosic solution is dropped into an acid solution, maintaining semi-spherical shapes with diameter between 3.4 and 3.9 mm, which is desirable for continuous-flow systems. Beads were tested for the removal of Congo red dye using a differential column batch reactor. Langmuir isotherm described the adsorption equilibrium, with maximum adsorption capacities of 98.1 and 139.6 mg/g for cellulose and cellulose-GNP beads. GNP increased the number of binding sites in the adsorbent. Removal efficiencies were higher than 90% within a broad range of initial concentration and sorbent loading. Static batch experiments evidenced slow kinetics for both sorbents, reaching equilibrium after 400 min. Hence, mass transfer was enhanced using a differential column batch reactor. The mass transfer coefficient, kL increased from 3.16 × 10−4 to 6.94 × 10−4 L/mg min, reaching equilibrium in half of the static adsorption time. External mass transfer resistance was minimized as turbulent flow is developed around the sorbent particles, allowing to obtain adsorption efficiencies close to 100% in a reasonably low time of 100 min. GNP promoted faster kinetics, as kL was 7.58 × 10−4 L/mg min. A model was developed to describe the adsorption dynamics based on the equilibrium. Although desorption was not favorable, cellulose-GNP beads’ direct disposal is attractive due to the sorbent’s hydrogel-like nature. A future work perspective is to evaluate these adsorbents under continuous fixed-bed operation.

Enzyme-Functionalized Cellulose Beads as a Promising Antimicrobial Material.

The extensive use of antibiotics over the last decades is responsible for the emergence of multidrug-resistant (MDR) microorganisms that are challenging health care systems worldwide. The use of alternative antimicrobial materials could mitigate the selection of new MDR strains by reducing antibiotic overuse. This paper describes the design of enzyme-based antimicrobial cellulose beads containing a covalently coupled glucose oxidase from Aspergillus niger (GOx) able to release antimicrobial concentrations of hydrogen peroxide (H2O2) (≈ 1.8 mM). The material preparation was optimized to obtain the best performance in terms of mechanical resistance, shelf life, and H2O2 production. As a proof of concept, agar inhibition halo assays (Kirby-Bauer test) against model pathogens were performed. The two most relevant factors affecting the bead functionalization process were the degree of oxidation and the pH used for the enzyme binding process. Slightly acidic conditions during the functionalization process (pH 6) showed the best results for the GOx/cellulose system. The functionalized beads inhibited the growth of all the microorganisms assayed, confirming the release of sufficient antimicrobial levels of H2O2. The maximum inhibition efficiency was exhibited toward Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), although significant inhibitory effects toward methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus were also observed. These enzyme-functionalized cellulose beads represent an inexpensive, sustainable, and biocompatible antimicrobial material with potential use in many applications, including the manufacturing of biomedical products and additives for food preservation.

Preparation and characterization of water-swellable hydrogel-forming porous cellulose beads

Water-swellable hydrogel-forming porous cellulose beads (HFPCBs) were obtained from a single-step thermal reaction between urea and sodium dihydrogen phosphate dihydrate on porous cellulose beads (PCBs). The HFPCBs maintained the interconnected porous structure of the PCBs and featured a specific surface area of 36.5 m2/g. Fourier transform infrared spectroscopy analysis indicated the introduction of cellulose phosphate carbamate into the HFPCBs. At the optimum reaction composition and time, HFPCBs showed a maximum centrifuge retention capacity of approximately 50 g/g in deionized water. The swelling behavior of the HFPCBs followed the second-order kinetics model. Despite their highly porous structure, HFPCBs had a compressive strength of several tens of kilopascal in the swollen state. To demonstrate their potential application, the swollen HFPCBs were successfully used for the germination of plant seeds.

Amidoxime-functionalized bead cellulose for the decomposition of highly toxic organophosphates.

Regenerated bead cellulose is a promising material with excellent mechanical and rheological properties, ideally suited for advanced environmental applications. By introducing the amidoxime functional group into the glucose unit at the C-6 position, highly effective reactive sorbent was prepared and used to destroy priority hazardous substances such as organophosphate pesticides or nerve-paralytic chemical warfare agents (CWAs). Quantum mechanical (QM) calculations were performed to study the interactions of organophosphates with amidoxime functional groups at the molecular level. It was found that the energetic reaction barrier of the rate-limiting step is markedly reduced (from 31.40 to 11.37 kcal mol−1) in the case of the amidoxime-catalysed degradation of parathion methyl, which resulted in a dramatic increase in the degradation rate; this was fully confirmed by experiments, in which the pesticide degradation proceeded at the time scale of several hours (t1/2 = 20–30 hours at pH 7.22).

Production of Cellulose Beads with TEAH-Urea Solvent and Dropping Technique: Effect of Inner Diameter of Syringe Needle

Production of Cellulose Beads with TEAH-Urea Solvent and Dropping Technique: Effect of Inner Diameter of Syringe Needle

Topochemical Engineering of Cellulose-Carboxymethyl Cellulose Beads: A Low-Field NMR Relaxometry Study.

The demand for more ecological, highly engineered hydrogel beads is driven by a multitude of applications such as enzyme immobilization, tissue engineering and superabsorbent materials. Despite great interest in hydrogel fabrication and utilization, the interaction of hydrogels with water is not fully understood. In this work, NMR relaxometry experiments were performed to study bead–water interactions, by probing the changes in bead morphology and surface energy resulting from the incorporation of carboxymethyl cellulose (CMC) into a cellulose matrix. The results show that CMC improves the swelling capacity of the beads, from 1.99 to 17.49, for pure cellulose beads and beads prepared with 30% CMC, respectively. Changes in water mobility and interaction energy were evaluated by NMR relaxometry. Our findings indicate a 2-fold effect arising from the CMC incorporation: bead/water interactions were enhanced by the addition of CMC, with minor additions having a greater effect on the surface energy parameter. At the same time, bead swelling was recorded, leading to a reduction in surface-bound water, enhancing water mobility inside the hydrogels. These findings suggest that topochemical engineering by adjusting the carboxymethyl cellulose content allows the tuning of water mobility and porosity in hybrid beads and potentially opens up new areas of application for this biomaterial.

Properties of cellulose and modified cellulose-alginate for rifampicin drug delivery

Oral drug delivery of rifampicin as tuberculosis healing treatment has several challenging issues such as poor solubility in water and short biological half-life resulting in some unfavorable side effects. Various polymeric materials have the prospective to overcome the obstacles correlated with rifampicin oral drug delivery to deliver controlled release and protect this drug from the severe gastric environment. In this study, alginate (Alg), alginate-cellulose (Alg-Cel), and alginate-C16TMABr modified cellulose (Alg-MCel) beads were prepared and evaluated as a potential agent for drug delivery of rifampicin. Numerous parameters were investigated, such as beads size, gel fraction, swelling ratio, encapsulation efficiency, and release percentage. The results showed that the addition of cellulose and C16TMABr modified cellulose into the alginate improves the encapsulation efficiency and controlled release of rifampicin.

26P Cellulose beads prepared in deep eutectic solvent function as carrier and cytoprotective encapsulation matrix for CAR-T cells in T-cell therapy against glioblastoma cells

26P Cellulose beads prepared in deep eutectic solvent function as carrier and cytoprotective encapsulation matrix for CAR-T cells in T-cell therapy against glioblastoma cells

Overexpression and Purification of Gracilariopsis chorda Carbonic Anhydrase (GcCAα3) in Nicotiana benthamiana, and Its Immobilization and Use in CO2 Hydration Reactions.

Carbonic anhydrase (CA; EC 4.2.2.1) is a Zn-binding metalloenzyme that catalyzes the reversible hydration of CO2. Recently, CAs have gained a great deal of attention as biocatalysts for capturing CO2 from industrial flue gases owing to their extremely fast reaction rates and simple reaction mechanism. However, their general application for this purpose requires improvements to stability at high temperature and under in vitro conditions, and reductions in production and scale-up costs. In the present study, we developed a strategy for producing GcCAα3, a CA isoform from the red alga Gracilariopsis chorda, in Nicotiana benthamiana. To achieve high-level expression and facile purification of GcCAα3, we designed various constructs by incorporating various domains such as translation-enhancing M domain, SUMO domain and cellulose-binding domain CBM3. Of these constructs, MC-GcCAα3 that had the M and CBM3 domains was expressed at high levels in N. benthamiana via agroinfiltration with a yield of 1.0 g/kg fresh weight. The recombinant protein was targeted to the endoplasmic reticulum (ER) for high-level accumulation in plants. Specific and tight CBM3-mediated binding of recombinant GcCAα3 proteins to microcrystalline cellulose beads served as a means for both protein purification from total plant extracts and protein immobilization to a solid surface for increased stability, facilitating multiple rounds of use in CO2 hydration reactions.

Cellulose aerogel particles: control of particle and textural properties in jet cutting process

Reported approach aims for the synthesis of spherical cellulose beads with high production rates (0.7–4.1 kg/h of hydrogel) via the so-called jet cutting method. To form particles, jets of aqueous cellulose/sodium hydroxide solutions were cut into pieces and collected in a gelation bath (30 wt% aqueous H2SO4, 20 °C). After solvent exchange with ethanol and subsequent supercritical drying, cellulose aerogel particles were obtained. The particles showed high specific surface areas (ca. 400 m2/g) and low bulk (untapped) densities (0.06–0.10 g/cm3). Variation of cellulose content (4–7 wt%) and jet cutting process parameters (cutting frequency, nozzle diameter, jet velocity) turned to be useful parameters for controlling the particles size and shape. Highly spherical particles with sphericity SPH ≥ 0.92 were obtained in a broad range of achievable particle sizes (0.4–1.0 mm), with an optimum of SPH at 6 wt% cellulose content.