Methylcellulose, a Cellulose Derivative with Original Physical Properties and Extended Applications

Advanced applications of smart electrospun nanofibers in cancer therapy: With insight into material capabilities and electrospinning parameters

Cancer remains a major global health challenge, and despite available treatments, its prognosis remains poor. Recently, researchers have turned their attention to intelligent nanofibers for cancer drug delivery. These nanofibers exhibit remarkable capabilities in targeted and controlled drug release. Their inherent characteristics, such as a high surface area-to-volume ratio, make them attractive candidates for drug delivery applications. Smart nanofibers can release drugs in response to specific stimuli, including pH, temperature, magnetic fields, and light. This unique feature not only reduces side effects but also enhances the overall efficiency of drug delivery systems. Electrospinning, a widely used method, allows the precision fabrication of smart nanofibers. Its advantages include high efficiency, user-friendliness, and the ability to control various manufacturing parameters. In this review, we explore the latest developments in producing smart electrospun nanofibers for cancer treatment. Additionally, we discuss the materials used in manufacturing these nanofibers and the critical parameters involved in the electrospinning process.

Extraction of cellulose from halophytic plants for the synthesis of a novel biocomposite

Cellulose nanofibers, a sustainable and promising material with widespread applications, exhibit appreciable strength and excellent mechanical and physicochemical properties. The preparation of cellulosic nanofibers from food or agricultural residue is not sustainable. Therefore, this study was designed to use three halophytic plants (Cressa cretica, Phragmites karka, and Suaeda fruticosa) to extract cellulose for the subsequent conversion to cellulosic nanofibers composites. The other extracted biomass components including lignin, hemicellulose, and pectin were also utilized to obtain industrially valuable enzymes. The maximum pectinase (31.56 IU mL-1), xylanase (35.21 IU mL-1), and laccase (15.89 IU mL-1) were produced after the fermentation of extracted pectin, hemicellulose, and lignin from S. fruticosa, P. karka, and C. cretica, respectively. Cellulose was methylated (with a degree of substitution of 2.4) and subsequently converted into a composite using polyvinyl alcohol. Scanning electron microscopy and Fourier-transform infrared spectroscopy confirmed the successful synthesis of the composites. The composites made up of cellulose from C. cretica and S. fruticosa had a high tensile strength (21.5 and 15.2 MPa) and low biodegradability (47.58% and 44.56%, respectively) after dumping for 3 months in soil, as compared with the composite from P. karka (98.79% biodegradability and 4.9 MPa tensile strength). Moreover, all the composites exhibited antibacterial activity against gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and gram-positive bacteria (Staphylococcus aureus). Hence, this study emphasizes the possibility for various industrial applications of biomass from halophytic plants.

Influence of the Acceptor Fluid on the Bupivacaine Release from the Prospective Intra-Articular Methylcellulose Hydrogel

Injections are one way of delivering drugs directly to the joint capsule. Employing this possibility, local anesthetic, such as bupivacaine (Bu), in the form of the suspension can be administered. The aim of this work was to propose a methylcellulose-based hydrogel-incorporated bupivacaine for intra-articular injections and to study the release kinetics of the drug from the hydrogel to different acceptor media, reflecting the synovial fluid of a healthy joint and the synovial fluid of an inflamed joint. The drug release studies were performed employing the flow apparatus. The drug was released to four different acceptor fluids: phosphate buffer pH = 7.4 (PBS7.4), phosphate buffer pH = 6.8 (PBS6.8), phosphate buffer pH = 7.4 with the high-molecular-weight sodium hyaluronate (PBS7.4H), and phosphate buffer pH = 6.8 with the low-molecular-weight sodium hyaluronate (PBS6.8L). The investigation was carried out at the temperature of 37 °C. The absorbance of the Bu released was measured at the wavelength of 262 nm every 2 min for 24 h. The release profiles of Bu to the acceptor media PBS7.4, PBS6.8, PBS7.4H, and PBS6.8L were described best by the first-order kinetics and the second-order equation. According to these models, the release rate constants were the highest when Bu was released to the fluid PBS7.4 and were k1 = (7.20 ± 0.01) × 10-5 min-1 and k2 = (3.00 ± 0.04) × 10-6 mg-1 × min-1, respectively. The relative viscosity of the acceptor medium, its pH, and the addition of high-molecular-weight or low-molecular-weight sodium hyaluronate (HAH or HAL) to the acceptor fluid influenced the drug dissolution. The release of Bu into the medium reflecting healthy synovial fluid takes a different pattern from its release into the fluid of an inflamed joint.

Evaluating a promising methylcellulose hydrogel for enhanced diabetic foot ulcer therapy through comprehensive preclinical studies

The present research focuses on formulating and evaluating hydrogels modified with crosslinking agents using methylcellulose to treat diabetic foot ulcers (DFU). Methylcellulose hydrogels are prepared and characterized for their crosslinking capacity through FTIR and degradation studies. The optimized hydrogel is further assessed for viscosity, gel strength, contact angle, in-vitro biodegradation, water-vapor transmission rate, anti-bacterial activity, and in-vivo efficacy. The results demonstrate that the developed hydrogel exhibits promising properties for DFU treatment, including increased wound healing percentage, improved ulcer morphology, reduced levels of proinflammatory cytokines, and enhanced tissue characteristics. These findings suggest that the novel hydrogel composition could serve as a viable alternative to existing dressings for DFU management.

Thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin for the treatment of peritoneal metastasis in colorectal cancer

Advanced colorectal cancer (CRC) with peritoneal metastasis (PM) is a highly aggressive malignancy with poor prognosis. Systematic chemotherapy and local treatments are the primary therapeutic approaches. However, systemic chemotherapy is limited by low accumulation of drugs at the tumor site and systemic toxicity. Local treatments include cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). However, CRS faces challenges related to incomplete tumor resection, while HIPEC is restricted by the uneven distribution of drugs and potential complications. Herein, a thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin (OXA) was synthesized to improve this situation. Specifically, methyl cellulose (MC) coagulated into a hydrogel, and OXA was loaded into the MC hydrogel to construct the OXA-MC hydrogel. We explored the OXA-MC hydrogel for the treatment of PM in CRC. The results demonstrated that the OXA-MC hydrogel had favorable biocompatibility and thermo-sensitivity and could act as a local slow-release drug carrier. Moreover, in a CT-26 tumor-bearing model, it showed a remarkable anti-tumor effect by inhibiting proliferation and promoting apoptosis. Additionally, transcriptome analysis indicated that the OXA-MC hydrogel might be involved in the regulation of the PI3K-AKT signaling pathway. In summary, we successfully prepared the OXA-MC hydrogel and provided a valid approach in the treatment of PM in CRC, which lays a foundation for other PM treatments.

Plant-Based Decellularization: A Novel Approach for Perfusion-Compatible Tissue Engineering Structures

This study explores the potential of plant-based decellularization in regenerative medicine, a pivotal development in tissue engineering focusing on scaffold development, modification, and vascularization. Plant decellularization involves removing cellular components from plant structures, offering an eco-friendly and cost-effective alternative to traditional scaffold materials. The use of plant-derived polymers is critical, presenting both benefits and challenges, notably in mechanical properties. Integration of plant vascular networks represents a significant bioengineering breakthrough, aligning with natural design principles. The paper provides an in-depth analysis of development protocols, scaffold fabrication considerations, and illustrative case studies showcasing plant-based decellularization applications. This technique is transformative, offering sustainable scaffold design solutions with readily available plant materials capable of forming perfusable structures. Ongoing research aims to refine protocols, assess long-term implications, and adapt the process for clinical use, indicating a path toward widespread adoption. Plant-based decellularization holds promise for regenerative medicine, bridging biological sciences with engineering through eco-friendly approaches. Future perspectives include protocol optimization, understanding long-term impacts, clinical scalability, addressing mechanical limitations, fostering collaboration, exploring new research areas, and enhancing education. Collectively, these efforts envision a regenerative future where nature and scientific innovation converge to create sustainable solutions, offering hope for generations to come.

Cellulose-Based Hydrogels for Wastewater Treatment: A Focus on Metal Ions Removal

The rapid worldwide industrial growth in recent years has made water contamination by heavy metals a problem that requires an immediate solution. Several strategies have been proposed for the decontamination of wastewater in terms of heavy metal ions. Among these, methods utilizing adsorbent materials are preferred due to their cost-effectiveness, simplicity, effectiveness, and scalability for treating large volumes of contaminated water. In this context, heavy metal removal by hydrogels based on naturally occurring polymers is an attractive approach for industrial wastewater remediation as they offer significant advantages, such as an optimal safety profile, good biodegradability, and simple and low-cost procedures for their preparation. Hydrogels have the ability to absorb significant volumes of water, allowing for the effective removal of the dissolved pollutants. Furthermore, they can undergo surface chemical modifications which can further improve their ability to retain different environmental pollutants. This review aims to summarize recent advances in the application of hydrogels in the treatment of heavy metal-contaminated wastewater, particularly focusing on hydrogels based on cellulose and cellulose derivatives. The reported studies highlight how the adsorption properties of these materials can be widely modified, with a wide range of adsorption capacity for different heavy metal ions varying between 2.3 and 2240 mg/g. The possibility of developing new hydrogels with improved sorption performances is also discussed in the review, with the aim of improving their effective application in real scenarios, indicating future directions in the field.

Novel animal product substitutes: A new category of plant-based alternatives to meat, seafood, egg, and dairy products

Many consumers are adopting plant-centric diets to address the adverse effects of livestock production on the environment, health, and animal welfare. Processed plant-based foods, including animal product analogs (such as meat, seafood, egg, or dairy analogs) and traditional animal product substitutes (such as tofu, seitan, or tempeh), may not be desirable to a broad spectrum of consumers. This article introduces a new category of plant-based foods specifically designed to overcome the limitations of current animal product analogs and substitutes: novel animal product substitutes (NAPS). NAPS are designed to contain high levels of nutrients to be encouraged (such as proteins, omega-3 fatty acids, dietary fibers, vitamins, and minerals) and low levels of nutrients to be discouraged (such as salt, sugar, and saturated fat). Moreover, they may be designed to have a wide range of appearances, textures, mouthfeels, and flavors. For instance, they could be red, orange, green, yellow, blue, or beige; they could be spheres, ovals, cubes, or pyramids; they could be hard/soft or brittle/pliable; and they could be lemon, thyme, curry, or chili flavored. Consequently, there is great flexibility in creating NAPS that could be eaten in situations where animal products are normally consumed, for example, with pasta, rice, potatoes, bread, soups, or salads. This article reviews the science behind the formulation of NAPS, highlights factors impacting their appearance, texture, flavor, and nutritional profile, and discusses methods that can be used to formulate, produce, and characterize them. Finally, it stresses the need for further studies on this new category of foods, especially on their sensory and consumer aspects.

Impact of Thermo-Responsive N-Acetylcysteine Hydrogel on Dermal Wound Healing and Oral Ulcer Regeneration

This study investigates the efficacy of a thermo-responsive N-acetylcysteine (NAC) hydrogel on wound healing and oral ulcer recovery. Formulated by combining NAC with methylcellulose, the hydrogel's properties were assessed for temperature-induced gelation and cell viability using human fibroblast cells. In vivo experiments on Sprague Dawley rats compared the hydrogel's effects against saline, NAC solution, and a commercial NAC product. Results show that a 5% NAC and 1% methylcellulose solution exhibited optimal outcomes. While modest improvements in wound healing were observed, significant enhancements were noted in oral ulcer recovery, with histological analyses indicating fully regenerated mucosal tissue. The study concludes that modifying viscosity enhances NAC retention, facilitating tissue regeneration. These findings support previous research on the beneficial effects of antioxidant application on damaged tissues, suggesting the potential of NAC hydrogels in improving wound care and oral ulcer treatment.

Electrospun nanofibers as advanced wound dressing materials: comparative analysis of single-layered and multilayered nanofibers containing polycaprolactone, methylcellulose, and polyvinyl alcohol

The dressing materials that provide surface protection, bacteriostatic activities, and tissue regeneration are important for the treatment and management of complex wounds. This study aimed to evaluate the wound-healing properties of electrospun nanofibers containing a blend of methylcellulose (MC) and polyvinyl alcohol (PVA). The nanofibers were tested in single-layered (S-NFs) and multilayered (M-NFs) forms (PCL/MC-PVA/PCL). In vitro scratch assay using L929 cells and in vivo experiments on Wistar rats were conducted. The results showed that both S-NFs and M-NFs significantly accelerated wound closure by promoting cell migration. M-NFs demonstrated superior wound healing activity compared to S-NFs. Additionally, M-NFs exhibited faster skin epithelization compared to S-NFs. Histopathological evaluation confirmed the absence of irritation or lesions on the healed wound surface. Overall, the study concluded that these polymeric nanofibers have the potential to be used as self-wound healing dressings. They are safe, non-toxic, biodegradable, and biocompatible.

Thermoresponsive keratin-methylcellulose self-healing injectable hydrogel accelerating full-thickness wound healing by promoting rapid epithelialization

Chronic wounds suffer from impaired healing due to microbial attack and poor vascular growth. Thermoresponsive hydrogels gained attention in wound dressing owing to their gelation at physiological temperature enabling them to take the shape of asymmetric wounds. The present study delineates the development of thermoresponsive hydrogel (MCK), from hair-derived keratin (K) and methylcellulose (MC) in the presence of sodium sulfate. The gelation temperature (Tg) of this hydrogel is in the range of 30 °C to 33 °C. Protein-polymer interaction leading to thermoreversible sol-gel transition involved in MCK blends has been analyzed and confirmed by FTIR, XRD, and thermal studies. Keratin, has introduced antioxidant properties to the hydrogel imparted cytocompatibility towards human dermal fibroblasts (HDFs) as evidenced by both MTT and live dead assays. In vitro wound healing assessment has been shown by enhanced migration of HDFs in the presence of MCK hydrogel compared to the control. Also, CAM assay and CD31 expression by the Wistar rat model has shown increased blood vessel branching after the implantation of MCK hydrogel. Further, in vivo study, demonstrated MCK efficacy of hydrogel in accelerating full-thickness wounds with minimal scarring in Wistar rats, re-epithelialization, and reinstatement of the epidermal-dermal junction thereby exhibiting clinical relevance for chronic wounds.

Transparent multifunctional cellulose-based conductive hydrogel for wearable strain sensors and arrays

Conductive hydrogels as promising candidate materials for flexible strain sensors have gained considerable attentions. However, it is still a great challenge to construct hydrogel with multifunctional performance via natural polymer. Herein, a novel multifunctional conductive hydrogel based on methylcellulose and cellulose nanocrystal was prepared via a facile and low-cost strategy. Methylcellulose (MC) was introduced to not only guarantee the stability of tannic acid coated cellulose nanocrystal (TA@CNCs) in LiCl solution, but also improve anti-freezing ability. The obtained hydrogel exhibited high transparency (98 % at 800 nm), good stretchability (663.1 %), low temperature tolerance (-23.9 °C), superior conductivity (2.89 S/m) and excellent UV shielding behavior. Flexible strain sensor assembled by the prepared hydrogels can be used to detect human body motions include subtle and large motions, and exhibited good sensitivity and stability over a wide temperature range. Multiple flexible hydrogels can also be assembled into a 3D sensor array to detect the distribution and magnitude of spatial pressure. Therefore, the hydrogels prepared via natural polymers will have broad application prospects in wearable devices, electronic skin and multifunctional sensor components.

Understanding Self-Assembly and Molecular Packing in Methylcellulose Aqueous Solutions Using Multiscale Modeling and Simulations

We present a multiscale molecular dynamics (MD) simulation study on self-assembly in methylcellulose (MC) aqueous solutions. First, using MD simulations with a new coarse-grained (CG) model of MC chains in implicit water, we establish how the MC chains self-assemble to form fibrils and fibrillar networks and elucidate the MC chains' packing within the assembled fibrils. The CG model for MC is extended from a previously developed model for unsubstituted cellulose and captures the directionality of H-bonding interactions between the -OH groups. The choice and placement of the CG beads within each monomer facilitates explicit modeling of the exact degree and position of methoxy substitutions in the monomers along the MC chain. CG MD simulations show that with increasing hydrophobic effect and/or increasing H-bonding strength, the commercial MC chains (with degree of methoxy substitution, DS, ∼1.8) assemble from a random dispersed configuration into fibrils. The assembled fibrils exhibit consistent fibril diameters regardless of the molecular weight and concentration of MC chains, in agreement with past experiments. Most MC chains' axes are aligned with the fibril axis, and some MC chains exhibit twisted conformations in the fibril. To understand the molecular driving force for the twist, we conduct atomistic simulations of MC chains preassembled in fibrils (without any chain twists) in explicit water at 300 and 348 K. These atomistic simulations also show that at DS = 1.8, MC chains adopt twisted conformations, with these twists being more prominent at higher temperatures, likely as a result of shielding of hydrophobic methyl groups from water. For MC chains with varying DS, at 348 K, atomistic simulations show a nonmonotonic effect of DS on water-monomer contacts. For 0.0 < DS < 0.6, the MC monomers have more water contacts than at DS = 0.0 or DS > 0.6, suggesting that with few methoxy substitutions, the MC chains are effectively hydrophilic, letting the water molecules diffuse into the fibril to participate in H-bonds with the MC chains' remaining -OH groups. At DS > 0.6, the MC monomers become increasingly hydrophobic, as seen by decreasing water contacts around each monomer. We conclude based on the atomistic observations that MC chains with lower degrees of substitutions (DS ≤ 0.6) should exhibit solubility in water over broader temperature ranges than DS ∼ 1.8 chains.

Dietary Fibre for the Prevention of Post-Pancreatitis Diabetes Mellitus: A Review of the Literature and Future Research Directions

Post-pancreatitis diabetes mellitus-the most common sequela of pancreatitis-leads to poorer glycaemic control compared with type 2 diabetes. Because post-pancreatitis diabetes mellitus is an exemplar of secondary diabetes (with a clear underlying cause), much post-pancreatitis diabetes mellitus is preventable or treatable early. Earlier literature established the important role of dietary fibre in reducing plasma glucose in individuals with type 2 diabetes. The present review benchmarks available evidence on the role of habitual dietary fibre intake in pancreatitis and post-pancreatitis diabetes mellitus. It also paves the way for future research on the use of dietary fibre in the post-pancreatitis setting.

Overview of processed excipients in ocular drug delivery: Opportunities so far and bottlenecks

Ocular drug delivery presents a unique set of challenges owing to the complex anatomy and physiology of the eye. Processed excipients have emerged as crucial components in overcoming these challenges and improving the efficacy and safety of ocular drug delivery systems. This comprehensive overview examines the opportunities that processed excipients offer in enhancing drug delivery to the eye. By analyzing the current landscape, this review highlights the successful applications of processed excipients, such as micro- and nano-formulations, sustained-release systems, and targeted delivery strategies. Furthermore, this article delves into the bottlenecks that have impeded the widespread adoption of these excipients, including formulation stability, biocompatibility, regulatory constraints, and cost-effectiveness. Through a critical evaluation of existing research and industry practices, this review aims to provide insights into the potential avenues for innovation and development in ocular drug delivery, with a focus on addressing the existing challenges associated with processed excipients. This synthesis contributes to a deeper understanding of the promising role of processed excipients in improving ocular drug delivery systems and encourages further research and development in this rapidly evolving field.

3D Coculture between Cancer Cells and Macrophages: From Conception to Experimentation

A tumor is a complex cluster with many types of cells in the microenvironment that help it grow. Macrophages, immune cells whose main role is to maintain body homeostasis, represent in the majority of cancers the most important cell population. In this context, they are called tumor-associated macrophages (TAMs) because of their phenotype, which contributes to tumor growth. In order to limit the use of animals, there is a real demand for the creation of in vitro models able to represent more specifically the complexity of the tumor microenvironment (TME) in order to characterize it and evaluate new treatments. However, the two-dimensional (2D) culture, which has been used for a long time, has shown many limitations, especially in terms of tumor representation. The three-dimensional (3D) models, developed over the last 20 years, have made it possible to get closer to what happens in vivo in terms of phenotypic and functional characteristics. Due to their architectural similarity to in vivo tissues, they provide a more physiologically relevant in vitro system. Most recently, it is the development of 3D coculture models in which two or three cell lines are cultured together that has allowed a better representation of TME with cell-cell interactions. Unfortunately, there is no clear direction for the design of these models at this time. In this Review on the coculture between cancer cells and TAMs, an in-depth analysis is performed to answer multiple questions on the conception of these models: Which models to use, and with which material and cancer lineage? Which monocyte or macrophage lines should be added to the coculture? And how can these models be exploited?

A new approach for the treatment of Alzheimer's disease: insulin-quantum dots

The potential use of insulin supplementation for Alzheimer's Disease (AD) was aimed to investigate and explore CQDs as an alternative delivery system. CQDs were produced by microwave and characterised. Insulin-loaded Ins-CQDs and in-situ Gel-Ins-CQDs were developed. The in vitro release kinetics, penetrations of insulin through excised sheep nasal mucosa were determined. Toxicity of CQDs were calculated on SH-SY5Y cells. The stability and usability of the prepared formulations were assessed. The insulin release from the solution was 70.75% after 3 hours, while it was 37.51% for in-situ Gel-Ins-CQDs. IC50 value was 52 µM. The mean particle diameters of Ins-CQDs and in-situ Gel-Ins-CQDs varied between 8.35 ± 0.19 to 8.75 ± 0.03 nm during a 6-month period. Zeta potentials ranged from -31.51 ± 1.39 to -24.43 ± 0.26 mV, and PDI values were between 9.8 ± 0.01 to 5.3 ± 3.2%(SD, n = 3) for Ins-CQDs and in-situ Gel-Ins-CQDs, respectively.Our results show that Gel-Ins-CQDs represented a controlled release over time and can be used for AD through the nasal route.

Valorization of waste biomass for synthesis of carboxy-methyl-cellulose as a sustainable edible coating on fruits: A review

The coating on fruits and vegetables increases the shelf-life by providing protection against their spoilage. The existing petroleum-based coating materials have considerable health threats. Edible coating materials prepared with the cellulose derivative extracted from the waste biomass could be a sustainable alternative and environment friendly process to increase the shelf-life periods of the post-harvest crops. Selection of suitable waste biomass and extraction of cellulose are the critical steps for the synthesis of cellulose-based edible film. Conversion of extracted cellulose into cellulosic macromolecular derivatives such as carboxy-methyl-cellulose (CMC) is vital for synthesizing edible coating formulation. Applications of sophisticated tools and methods for the characterization of the coated fruits would be helpful to determine the efficiency of the coating material. In this review, we focused on: i) criteria for the selection of suitable waste biomass for extraction of cellulose, ii) pretreatment and extraction process of cellulose from the different waste biomasses, iii) synthesis processes of CMC by using extracted cellulose, iv) characterizations of CMC as food coating materials, v) various formulation techniques for the synthesis of the CMC based food coating materials and vi) the parameters which are used to evaluate the shelf-life performance of different coated fruits.

Readily soluble cellulose-based fluorescent probes for the detection and removal of Fe3+ ion

Cellulose is an economical, biodegradable, widely available, and eco-friendly natural macromolecule. But its utilization has been restricted due to its insolubility in water and common organic solvents. In this work, soluble fluorescent probes based on cellulose were synthesized. Firstly, the primary hydroxyl group in glucose units was reacted with SOCl2 to introduce Cl and obtain chloro-cellulose (Cell-Cl). This operation breaks down the regular structure and hydrogen bonding of the original cellulose, enabling it to dissolve in DMSO. Secondly, the Cell-Cl reacted with CS2 and 2-mercaptobenzothiazole to obtain a cellulose-based macromolecular RAFT reagent (Cell-CTA). Finally, the fluorescent monomers which bears -C=C- and naphthalimide, and methacrylic acid (MAA) were grafted onto the main chain of cellulose through RAFT polymerization. Thus, cellulose-based readily soluble macromolecular fluorescent probes were obtained. The cellulose-based probes can specifically recognize Fe3+ in pure water and can be recycled and regenerated. Additionally, the cellulose-based probes exhibit remarkable adsorption and separation properties for Fe3+ ions. The modification of cellulose decreases its crystallinity and introduces hydrophilic groups and fluorophores, which enables cellulose to be soluble in both pure water and the organic solvent DMSO. This work expands the application range of cellulose-based copolymers.

Simplified PCR-Based Quantification of Proteins with DNA Aptamers and Methylcellulose as a Blocking Agent

Due to their unique three-dimensional structure, DNA or RNA oligonucleotide aptamers bind to various molecules with high affinity and specificity. Aptamers, alone or in combination with antibodies, can be used to sensitively quantify target molecules by quantitative real-time polymerase chain reaction (qPCR). However, the assays are often complicated and unreliable. In this study, we explored the feasibility of performing the entire assay on wells of routinely used polypropylene PCR plates. We found that polypropylene wells efficiently bind proteins. This allows the entire assay to be run in a single well. To minimize nonspecific binding of the assay components to the polypropylene wells, we tested various blocking agents and identified methylcellulose as an effective alternative to the commonly used BSA. Methylcellulose not only demonstrates comparable or superior blocking capabilities but also offers the advantage of a well-defined composition and non-animal origin. Our findings support the utilization of aptamers, either alone or in combination with antibodies, for sensitive quantification of selected molecules immobilized in polypropylene PCR wells in a streamlined one-well qPCR assay under well-defined conditions.

Jute Stick-Derived Cellulose-Based Hydrogel: Synthesis, Characterization, and Methylene Blue Removal from Aqueous Solution

In this work, microcrystalline cellulose (MCC) was isolated from jute sticks and sodium carboxymethyl cellulose (Na-CMC) was synthesized from the isolated MCC. Na-CMC is an anionic derivative of microcrystalline cellulose. The microcrystalline cellulose-based hydrogel (MCCH) and Na-CMC-based hydrogel (Na-CMCH) were prepared by using epichlorohydrin (ECH) as a crosslinker by a chemical crosslinking method. The isolated MCC, synthesized Na-CMC, and corresponding hydrogels were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electronic microscopy (SEM), and energy dispersive spectroscopy (EDS) for functional groups, crystallinity, surface morphology, and composite elemental composition, respectively. Pseudo-first-order, pseudo-second-order, and Elovich models were used to investigate the adsorption kinetics. The pseudo-second-order one is favorable for both hydrogels. Freundlich, Langmuir, and Temkin adsorption isotherm models were investigated. MCCH follows the Freundlich model (R2 = 0.9967), and Na-CMCH follows the Langmuir isotherm model (R2 = 0.9974). The methylene blue (MB) dye adsorption capacities of ionic (Na-CMCH) and nonionic (MCCH) hydrogels in different contact times (up to 600 min), initial concentrations (10-50 ppm), and temperatures (298-318 K) were investigated and compared. The maximum adsorption capacity of MCCH and Na-CMCH was 23.73 and 196.46 mg/g, respectively, and the removal efficiency of MB was determined to be 26.93% for MCCH and 58.73% for Na-CMCH. The Na-CMCH efficiently removed the MB from aqueous solutions as well as spiked industrial wastewater. The Na-CMCH also remarkably efficiently reduced priority metal ions from an industrial effluent. An effort has been made to utilize inexpensive, readily available, and environmentally friendly waste materials (jute sticks) to synthesize valuable adsorbent materials.

Investigation of Biomaterial Ink Viscosity Properties and Optimization of the Printing Process Based on Pattern Path Planning

Extruded bioprinting is widely used for the biomanufacturing of personalized, complex tissue structures, which requires biomaterial inks with a certain viscosity to enable printing. However, there is still a lack of discussion on the controllable preparation and printability of biomaterial inks with different viscosities. In this paper, biomaterial inks composed of gelatin, sodium alginate, and methylcellulose were utablesed to investigate the feasibility of adjustment of rheological properties, thereby analyzing the effects of different rheological properties on the printing process. Based on the response surface methodology, the relationship between the material components and the rheological properties of biomaterial inks was discussed, followed by the prediction of the rheological properties of biomaterial inks. The prediction accuracies of the power-law index and consistency coefficient could reach 96% and 79%, respectively. The material group can be used to prepare biomaterial inks with different viscosity properties in a wide range. Latin hypercube sampling and computational fluid dynamics were used to analyze the effects of different rheological properties and extrusion pressure on the flow rate at the nozzle. The relationship between the rheological properties of the biomaterial ink and the flow rate was established, and the simulation results showed that the changes in the rheological properties of the biomaterial ink in the high-viscosity region resulted in slight fluctuations in the flow rate, implying that the printing process for high-viscosity biomaterial inks may have better versatility. In addition, based on the characteristics of biomaterial inks, the printing process was optimized from the planning of the print pattern to improve the location accuracy of the starting point, and the length accuracy of filaments can reach 99%. The effect of the overlap between the fill pattern and outer frame on the print quality was investigated to improve the surface quality of complex structures. Furthermore, low- and high-viscosity biomaterial inks were tested, and various printing protocols were discussed for improving printing efficiency or maintaining cell activity. This study provides feasible printing concepts for a wider range of biomaterials to meet the biological requirements of cell culture and tissue engineering.

Corrected solid-state 13 C nuclear magnetic resonance peak assignment and side-group quantification of hydroxypropyl methylcellulose acetyl succinate pharmaceutical excipients

Hydroxypropyl methylcellulose acetyl succinate (HPMCAS) is widely used as a pharmaceutical excipient, making a detailed understanding of its tunable structure important for formulation design. Several recently reported peak assignments in the solid-state 13 C NMR spectrum of HPMCAS have been corrected here using peak integrals in quantitative spectra, spectral editing, empirical chemical-shift predictions based on solution NMR, and full spectrum simulation analogous to deconvolution. Unlike in cellulose, the strong peak at 84 ppm must be assigned to C2 and C3 methyl ethers, instead of regular C4 of cellulose. The proposed assignment of signals at <65 ppm to OCH sites, including C5 of cellulose, could not be confirmed. CH2 spectral editing showed two resolved OCH2 bands, a more intense one from O-CH2 ethers of C6 at >69 ppm and a smaller one from its esters and possibly residual CH2 -OH groups, near 63 ppm. The strong intensities of resolved signals of acetyl, succinoyl, and oxypropyl substituents indicated the substitution of >85% of the OH groups in HPMCAS. The side-group concentrations in three different grades of HPMCAS were quantified.

Modulation of surface properties of cellulose nanocrystals through adsorption of tannic acid and alkyl cellulose derivatives

Cellulose nanocrystals (CNCs) are hydrophilic nanoparticles that cannot be dispersed in non-polar solvents or hydrophobic polymer matrices. Here, we demonstrate the tunable modification of CNC surfaces by physical adsorption of tannic acid (TA) and two alkyl cellulose derivatives (ACDs), methyl cellulose (MC) and ethyl cellulose (EC), while maintaining their sustainable nature. We compare the impact of ACD adsorption when mixed with CNCs to CNCs precoated with tannic acid (CNC@TA), varying ACD weight fractions in CNC suspensions. Our results show that CNC@ACD and CNC@TA@ACD aqueous suspensions display good colloidal stability in water, while their surface properties are altered. We use a wide range of analytical techniques to characterize these suspensions, with a focus on their interaction with water. The two selected ACDs adsorb on both CNCs and CNC@TA at low fractions (ACD ≤ 10 % w/w), followed by an intermediate region of saturation between 10 % and 30 % w/w. At fractions above 30 % w/w, we observe the formation of CNC- or CNC@TA-reinforced ACD composites. Most samples can be redispersed in water upon freeze-drying, except for EC-rich samples redispersible in toluene. Our facile method for preparing ACD-coated CNCs allows for the creation of a range of nanomaterials with modulable wetting and emulsification properties.

Crosslinking strategies in modulating methylcellulose hydrogel properties

Methylcellulose (MC) hydrogels are ideal materials for the design of thermo-responsive platforms capable of exploiting the environment temperature as a driving force to activate their smart transition. However, MC hydrogels usually show reduced stability in an aqueous environment and low mechanical properties, limiting their applications' breadth. A possible approach intended to overcome these limitations is chemical crosslinking, which represents a simple yet effective strategy to modify the MC hydrogels' properties (e.g., physicochemical, mechanical, and biological). In this regard, understanding the selected crosslinking method's role in modulating the MC hydrogels' properties is a key factor in their design. This review offers a perspective on the main MC chemical crosslinking approaches reported in the literature. Three main categories can be distinguished: (i) small molecule crosslinkers, (ii) crosslinking by high-energy radiation, and (iii) crosslinking via MC chemical modification. The advantages and limitations of each approach are elucidated, and special consideration is paid to the thermo-responsive properties after crosslinking towards the development of MC hydrogels with enhanced physical stability and mechanical performance, preserving the thermo-responsive behavior.

Development of Film-Forming Gel Formulations Containing Royal Jelly and Honey Aromatic Water for Cosmetic Applications

This study aimed to develop a film-forming gel containing honey aromatic water (HW) and royal jelly (RJ) for cosmetic applications as a facial peel-off mask. HW, which is industrial waste from the water-reduction process of honey, was sterilized by autoclaving and filtration through a 0.22 µm membrane. The film-forming gels were developed using various types of film-forming polymers, including polyvinyl alcohol (PVA 117), carboxymethyl cellulose (CMC), and hydroxyethyl cellulose (HEC). The gel formulations were characterized in terms of their external appearance, viscosity, pH, and drying time, whereas the films generated were characterized by a texture analyzer, microscopic investigation, Fourier transform infrared, and an X-ray diffractometer. The findings highlighted that HW has short storage shelf life due to microbial contamination. Sterilizations were required before further product development. The film-forming gel was created by using the combination of PVA 117, CMC, and HEC. HW and RJ were successfully incorporated into the film-forming gel. However, HW resulted in a decrease in the gel viscosity and mechanical properties of its film. Interestingly, the drying time was dramatically decreased, which would be more desirable for its use as a peel-off mask. Furthermore, incorporation of royal jelly enhanced the viscosity of the gels as well as improved the mechanical properties of the film. No effect on the chemical and crystal structure of the films was detected after the incorporation. Therefore, the film-forming gels containing HW and RJ, possessing aesthetic attributes that extended to both the gels themselves and the resultant films, were suitable for use as a peel-off mask.

Double-Cross-Linked Hydrogel with Long-Lasting Underwater Adhesion: Enhancement of Maxillofacial In Situ and Onlay Bone Retention

Bone retention is a usual clinical problem existing in a lot of maxillofacial surgeries involving bone reconstruction and bone transplantation, which puts forward the requirements for bone adhesives that are stable, durable, biosafe, and biodegradable in wet environment. To relieve the suffering of patients during maxillofacial surgery with one-step operation and satisfying repair, herein, we developed a double-cross-linked A-O hydrogel named by its two components: [(3-Aminopropyl) methacrylamide]-co-{[Tris(hydroxymethyl) methyl] acrylamide} and oxidated methylcellulose. With excellent bone adhesion ability, it can maintain long-lasting stable underwater bone adhesion for over 14 days, holding a maximum adhesion strength of 2.32 MPa. Schiff-base reaction and high-density hydrogen bonds endow the hydrogel with strong cohesion and adhesion performance as well as maneuverable properties such as easy formation and injectability. A-O hydrogel not only presents rarely reported long-lasting underwater adhesion of hard tissue but also owns inherent biocompatibility and biodegradation properties with a porous structure that facilitates the survival of bone graft. Compared to the commercial cyanoacrylate adhesive (3 M Vetbond Tissue Adhesive), the A-O hydrogel is confirmed to be safer, more stable, and more effective in calvarial in situ bone retention model and onlay bone retention model of rat, providing a practical solution for the everyday scenario of clinical bone retention.

Emerging Applications of Hydroxypropyl Methylcellulose Acetate Succinate: Different Aspects in Drug Delivery and Its Commercial Potential

Hydroxypropyl methylcellulose acetate succinate (HPMCAS) has multi-disciplinary applications spanning across the development of drug delivery systems, in 3D printing, and in tissue engineering, etc. HPMCAS helps in maintaining the drug in a super-saturated condition by inhibiting its precipitation, thereby increasing the rate and extent of dissolution in the aqueous media. HPMCAS has several distinctive characteristics, such as being amphiphilic in nature, having an ionization pH, and a succinyl and acetyl substitution ratio, all of which are beneficial while developing formulations. This review provides insights regarding the various types of formulations being developed using HPMCAS, including amorphous solid dispersion (ASD), amorphous nanoparticles, dry coating, and 3D printing, along with their applicability in drug delivery and biomedical fields. Furthermore, HPMCAS, compared with other carbohydrate polymers, shows several benefits in drug delivery, including proficiency in imparting stable ASD with a high dissolution rate, being easily processable, and enhancing bioavailability. The various commercially available formulations, regulatory considerations, and key patents containing the HPMCAS have been discussed in this review.

Evaluation of a protocol to assess a novel artificial biofilm equivalent for dentures-A prospective clinical pilot study

OBJECTIVES

This pilot study aimed to carry out preliminary tests of the removability of an artificial biofilm equivalent (ABE) and to verify the reproducibility of the ABE testing protocol for a planned main study.

BACKGROUND

There is a lack of data to develop suitable artificial biofilm substitutes, which may be helpful to perform denture hygiene education and to carry out in vitro examinations of oral hygiene products.

MATERIALS AND METHODS

This single-group, prospective, longitudinal, interventional pilot study was conducted in Dresden (Germany) from February until December 2020. Participants were recruited who wore fully functional upper complete dentures. Denture biofilm was grown on acrylic specimens by wearing dentures for 12 h and 36 h using intraoral appliances. Acrylic specimens were coated with ABEs of three compositions: chitosan (ChS) 0.3 g, methylcellulose (MC) 1.7 g; ChS 0.2 g, MC 1.8 g; ChS 0.1 g, MC 1.9 g (labelled 1.7MC, 1.8MC and 1.9MC, respectively). All specimens underwent standardised mechanical brushing. The percentages of remaining biofilm (POB) were measured.

RESULTS

Thirty-one participants were prescreened, and eight (26%) were included. The appliances were well tolerated, and biofilm was collected. ABE was prepared and brushed as planned. Three and six brushing strokes were needed to remove 12-h and 36-h natural denture biofilm, respectively. Correspondingly, three brushing strokes were needed to remove 1.9MC ABE and six brushing strokes to remove 1.8MC and 1.7MC ABE. A reproducibility of ABE removal was indicated.

CONCLUSION

The removability of ABE and the ABE testing protocol were feasible and reproducible for conducting the future main study.

Bioinks for Space Missions: The Influence of Long-Term Storage of Alginate-Methylcellulose-Based Bioinks on Printability as well as Cell Viability and Function

Bioprinting is considered a key technology for future space missions and is currently being established on the International Space Station (ISS). With the aim to perform bioink production as a critical and resource-consuming preparatory step already on Earth and transport a bioink cartridge "ready to use" to the ISS, the storability of bioinks is investigated. Hydrogel blends based on alginate and methylcellulose are laden with either green microalgae of the species Chlorella vulgaris or with different human cell lines including immortilized human mesenchymal stem cells, SaOS-2 and HepG2, as well as with primary human dental pulp stem cells. The bioinks are filled into printing cartridges and stored at 4°C for up to four weeks. Printability of the bioinks is maintained after storage. Viability and function of the cells embedded in constructs bioprinted from the stored bioinks are investigated during subsequent cultivation: The microalgae survive the storage period very well and show no loss of growth and functionality, however a significant decrease is visible for human cells, varying between the different cell types. The study demonstrates that storage of bioinks is in principle possible and is a promising starting point for future research, making complex printing processes more effective and reproducible.

Classification, gelation mechanism and applications of polysaccharide-based hydrocolloids in pasta products: A review

Polysaccharide-based hydrocolloids (PBHs) are a group of water-soluble polysaccharides with high molecular weight hydrophilic long-chain molecules, which are widely employed in food industry as thickeners, emulsifiers, gelling agents, and stabilizers. Pasta products are considered to be an important source of nutrition for humans, and PBHs show great potential in improving their quality and nutritional value. The hydration of PBHs to form viscous solutions or sols under specific processing conditions is a prerequisite for improving the stability of food systems. In this review, PBHs are classified in a novel way according to food processing conditions, and their gelation mechanisms are summarized. The application of PBHs in pasta products prepared under different processing methods (baking, steaming/cooking, frying, freezing) are reviewed, and the potential mechanism of PBHs in regulating pasta products quality is revealed from the interaction between PBHs and the main components of pasta products (protein, starch, and water). Finally, the safety of PBHs is critically explored, along with future perspectives. This review provides a scientific foundation for the development and specific application of PBHs in pasta products, and provides theoretical support for improving pasta product quality.

Biodegradable Polymer-Based Drug-Delivery Systems for Ocular Diseases

Ocular drug delivery is a challenging field due to the unique anatomical and physiological barriers of the eye. Biodegradable polymers have emerged as promising tools for efficient and controlled drug delivery in ocular diseases. This review provides an overview of biodegradable polymer-based drug-delivery systems for ocular diseases with emphasis on the potential for biodegradable polymers to overcome the limitations of conventional methods, allowing for sustained drug release, improved bioavailability, and targeted therapy. Natural and synthetic polymers are both discussed, highlighting their biodegradability and biocompatibility. Various formulation strategies, such as nanoparticles, hydrogels, and microemulsions, among others, are investigated, detailing preparation methods, drug encapsulation, and clinical applications. The focus is on anterior and posterior segment drug delivery, covering glaucoma, corneal disorders, ocular inflammation, retinal diseases, age-related macular degeneration, and diabetic retinopathy. Safety considerations, such as biocompatibility evaluations, in vivo toxicity studies, and clinical safety, are addressed. Future perspectives encompass advancements, regulatory considerations, and clinical translation challenges. In conclusion, biodegradable polymers offer potential for efficient and targeted ocular drug delivery, improving therapeutic outcomes while reducing side effects. Further research is needed to optimize formulation strategies and address regulatory requirements for successful clinical implementation.

Soluble Dietary Fibers as Antihyperlipidemic Agents: A Comprehensive Review to Maximize Their Health Benefits

The number of hypercholesterolemic people is increasing rapidly worldwide, with elevated lipid profiles representing a major risk factor of coronary heart diseases. Dietary intervention was shown to improve the lipid profile, thus enhancing the quality of life. Dietary fiber is a nondigestible form of carbohydrates, due to the lack of the digestive enzyme in humans required to digest fiber, and is classified according to its water solubility properties as either soluble (SDF) or insoluble dietary fiber (IDF). Consumption of SDF is associated with several health benefits such as reduced lipid levels, lower blood pressure, improved blood glucose control, improved immune function, and reduced inflammation. SDF has been shown to lower blood cholesterol by several action mechanisms including directly due to the gelling, mucilaginous, and viscous fiber nature, and indirectly due to its fermented products and modulation of the gut microbiome. This review aims to provide a holistic overview on how SDF impacts the lipid profile. We start by providing an overview of the chemical structure of the major SDFs including mucilage, gums (gum arabic and guar gum), pectin, and inulin.

Bacterial cellulose: Biopolymer with novel medical applications

Due to the growing importance of green chemistry, the search for alternatives to cellulose has begun, leading to the rediscovery of bacterial cellulose (BC). The material is produced by Gluconacetobacter and Acetobacter bacteria, mainly Komagataeibacter xylinus. It is a pure biopolymer, without lignin or hemicellulose, forming a three-dimensional mesh, showing much lower organization than its plant counterpart. Thanks to its design, it has proven itself in completely unprecedented applications - especially in the field of biomedical sciences. Coming in countless forms, it has found use in applications such as wound dressings, drug delivery systems, or tissue engineering. The review article focuses on discussing the main structural differences between plant and bacterial cellulose, methods of bacterial cellulose synthesis, and the latest trends in BC applications in biomedical sciences.

Highly efficient mRNA delivery with nonlinear microfluidic cell stretching for cellular engineering

In the past few years, messenger RNA (mRNA) has emerged as a promising therapeutic agent for the treatment and prevention of various diseases. Clinically, mRNA-based drugs have been used for cancer immunotherapy, infectious diseases, and genomic disorders. To maximize the therapeutic efficacy of mRNA, the exact amount of mRNAs must be delivered to the target locations without degradation; however, traditional delivery modalities, such as lipid carriers and electroporation, are suboptimal because of their high cost, cell-type sensitivity, low scalability, transfection/delivery inconsistency, and/or loss of cell functionality. Therefore, new effective and stable delivery methods are required. Accordingly, we present a novel nonlinear microfluidic cell stretching (μ-cell stretcher) platform that leverages viscoelastic fluids, i.e., methylcellulose (MC) solutions, and cell mechanoporation for highly efficient and robust intracellular mRNA delivery. In the proposed platform, cells suspended in MC solutions with mRNAs were injected into a microchannel where they rapidly passed through a single constriction. Owing to the use of viscoelastic MC solutions, a high shear force was applied to the cells, effectively creating transient nanopores. This feature allows mRNAs to be effectively internalized through generated membrane discontinuities. Using this platform, high delivery efficiency (∼97%), high throughput (∼3.5 × 10⁵ cells per min), cell-type-/cargo-size-insensitive delivery, simple operation (single-step), low analyte consumption, low-cost operation (<$1), and nearly clogging-free operation were demonstrated, demonstrating the high potential of the proposed platform for application in mRNA-based cellular engineering research.

Enriched Pea Protein Texturing: Physicochemical Characteristics and Application as a Substitute for Meat in Hamburgers

There is currently a growing trend towards the consumption of vegetable protein, even if it shows some deficiencies in essential amino acids. It has been driven by consumer passion for health and wellness, environmental sustainability, animal welfare and the flexitarian lifestyle. However, the formulation of plant protein food analogues to meat products is complicated by the technological properties of isolated plant protein. One of the processes used to improve these properties is the texturisation of the protein by extrusion, as well as the use of other plant materials that can enrich the formulation. Therefore, the aim of this study was to evaluate the effect of pea protein (PP) enriched with lucerne (L), spinach (S) and Chlorella (C) in powdered and texturised forms on the physicochemical properties and extrusion parameters, and to evaluate its technological and sensory quality as a meat analogue in vegetal hamburgers. Texturisation reduced the number of soluble components released, thus reducing the molecular degradation in extruded material. The texturised samples were significantly (p < 0.05) less hygroscopic than the non-textured samples. Once the properties of the powder and texturised had been analysed, they were used to prepare vegetal hamburgers. The addition of vegetable-enriched texturised samples with high chlorophyll content led to more intense colour changes in the vegetal hamburgers during cooking, with PP+C providing the darkest colouring, and also resulted in a final product more similar to a traditional meat hamburger, with higher overall and meat odour/flavour intensity, hardness, juiciness and chewiness, and less legume and spice odour and flavour. Overall, texturisation improved the technological properties of the enriched protein isolate, allowing for more efficient production of vegetal hamburgers.

Synthesis of methylcellulose-polyvinyl alcohol composite, biopolymer film and thermostable enzymes from sugarcane bagasse

Agro-industrial wastes and by-products are the natural and abundant resources of biomaterials to obtain various value-added items such as biopolymer films, bio-composites and enzymes. This study presents a way to fractionate and to convert an agro-industrial residue, sugarcane bagasse (SB), into useful materials with potential applications. Initially cellulose was extracted from SB which was then converted into methylcellulose. The synthesized methylcellulose was characterized by scanning electron microscopy and FTIR. Biopolymer film was prepared by using methylcellulose, polyvinyl alcohol (PVA), glutaraldehyde, starch and glycerol. The biopolymer was characterized to exhibit 16.30 MPa tensile strength, 0.05 g/m² h of water vapor transmission rate, 366 % of water absorption to its original weight after 115 min of immersion, 59.08 % water solubility, 99.05 % moisture retention capability and 6.01 % of moisture absorption after 144 h. Furthermore, in vitro studies on absorption and dissolution of model drug by biopolymer showed 2.04 and 104.59 % of swelling ratio and equilibrium water content, respectively. Biocompatibility of the biopolymer was checked by using gelatin media and it was observed that swelling ratio was higher in initial 20 min of contact. The extracted hemicellulose and pectin from SB were fermented by a thermophilic bacterial strain, Neobacillus sedimentimangrovi UE25 that yielded 12.52 and 6.4 IU mL^-1 of xylanase and pectinase, respectively. These industrially important enzymes further augmented the utility of SB in this study. Therefore, this study emphasizes the possibility for industrial application of SB to form various products.

Shear rheology of methyl cellulose based solutions for cell mechanical measurements at high shear rates

Methyl cellulose (MC) is a widely used material in various microfluidic applications in biology. Due to its biocompatibility, it has become a popular crowding agent for microfluidic cell deformability measurements, which usually operate at high shear rates (>10 000 s^-1). However, a full rheological characterization of methyl cellulose solutions under these conditions has not yet been reported. With this study, we provide a full shear-rheological description for solutions of up to 1% MC dissolved in phosphate-buffered saline (PBS) that are commonly used in real-time deformability cytometry (RT-DC). We characterized three different MC-PBS solutions used for cell mechanical measurements in RT-DC with three different shear rheometer setups to cover a range of shear rates from 0.1-150 000 s^-1. We report viscosities and normal stress differences in this regime. Viscosity functions can be well described using a Carreau-Yasuda model. Furthermore, we present the temperature dependency of shear viscosity and first normal stress difference of these solutions. Our results show that methyl cellulose solutions behave like power-law liquids in viscosity and exhibit first normal stress difference at shear rates between 5000-150 000 s^-1. We construct a general viscosity equation for each MC solution at a certain shear rate and temperature. Furthermore, we investigated how MC concentration influences the rheology of the solutions and found the entanglement concentration at around 0.64 w/w%. Our results help to better understand the viscoelastic behavior of MC solutions, which can now be considered when modelling stresses in microfluidic channels.

Microfluidic techniques for mechanical measurements of biological samples

The use of microfluidics to make mechanical property measurements is increasingly common. Fabrication of microfluidic devices has enabled various types of flow control and sensor integration at micrometer length scales to interrogate biological materials. For rheological measurements of biofluids, the small length scales are well suited to reach high rates, and measurements can be made on droplet-sized samples. The control of flow fields, constrictions, and external fields can be used in microfluidics to make mechanical measurements of individual bioparticle properties, often at high sampling rates for high-throughput measurements. Microfluidics also enables the measurement of bio-surfaces, such as the elasticity and permeability properties of layers of cells cultured in microfluidic devices. Recent progress on these topics is reviewed, and future directions are discussed.

Mucoadhesive chitosan-methylcellulose oral patches for the treatment of local mouth bacterial infections

Mucoadhesive buccal patches are dosage forms promising for successful drug delivery. They show the distinctive advantages of long residence time on the oral mucosa and increased in situ drug bioavailability. In this context, electrophoretic deposition (EPD) of chitosan (CS) has been demonstrated as a simple and easily tunable technique to produce mucoadhesive buccal patches. However, CS-based buccal patches may suffer from weak mucoadhesion, which can impair their therapeutic effect. In this work, methylcellulose (MC), a widely investigated biopolymer in the biomedical area, was exploited to increase the mucoadhesive characteristic of pristine CS patches. CS-MC patches were obtained in a one-pot process via EPD, and the possibility of incorporating gentamicin sulfate (GS) as a model of a broad-spectrum antibiotic in the so-obtained patches was investigated. The resulting CS-MC patches showed high stability in a water environment and superior mucoadhesive characteristic (σ_adh = 0.85 ± 0.26 kPa, W_adh = 1192.28 ± 602.36 Pa mm) when compared with the CS control samples (σ_adh = 0.42 ± 0.22 kPa, W_adh = 343.13 ± 268.89 Pa mm), due to both the control of the patch porosity and the bioadhesive nature of MC. Furthermore, GS-loaded patches showed no in vitro cytotoxic effects by challenging L929 cells with material extracts and noteworthy antibacterial activity on both Gram-positive and Gram-negative bacterial strains.

Aryloxy Ionic Liquid-Catalyzed Homogenous Esterification of Cellulose with Low-Reactive Acyl Donors

Ionic liquids (ILs) are recyclable, non-volatile, and can dissolve cellulose, a natural polymer that is insoluble in versatile solvents. Therefore, ILs have been used to modify cellulose. However, 1-ethyl-3-methylimidazolium acetate (EmimOAc), a commercially available IL often used to dissolve and modify cellulose to prepare cellulose-based materials, causes the undesired introduction of an acetyl group derived from the acetate anion of EmimOAc onto the hydroxy group of cellulose during esterification. In this study, for cellulose esterification, we prepared aryloxy ILs as non-carboxylate-type and basic ILs, which can theoretically prevent the undesired introduction of an acyl group from the IL onto the hydroxy group of cellulose. The optimized 1-ethyl-3-methylimidazolium 2-pyridinolate (Emim2OPy) and mixed solvent system achieved rapid cellulose esterification (within 30 min) with an excellent degree of substitution (DS) value (up to >2.9) derived from the employed low-reactive vinyl esters and bio-based unsaturated aldehydes, without any undesired substituent introduction from side reactions.

Wood Hemicelluloses as Innovative Wall Materials for Spray-Dried Microencapsulation of Berry Juice: Part 1—Effect of Homogenization Techniques on their Feed Solution Properties

The use of wood hemicelluloses, including galactoglucomannans (GGM) and glucuronoxylans (GX), in spray-dried microencapsulation of bioactive compounds has not been reported. Our study aims to investigate the benefits of spray-dried GGM and GX powders (sGGM and sGX) along with the effects of homogenization techniques (magnetic stirring, ultrasonication, and a combination of UltraTurrax homogenization and microfluidization) on the physicochemical properties of feed solutions (10–20%, w/w). Feed solutions of bilberry juice with sGGM, sGX, and mixtures of either sGGM or sGX with methylcellulose (MC) or carboxymethylcellulose (CMC) were examined to produce highly stable feed solutions for spray-dried microencapsulation. The effects of ultrasonication amplitudes (30–80%) on the viscosity and particle size distribution of sGGM feed solutions were more profound than observed in their sGX counterparts. Unlike sGX feed solutions, sGGM feed solutions homogenized by ultrasonication and microfluidization formed a gel-like structure. Microfluidization also caused a loss of total anthocyanin content (TAC) of the feed solutions. Magnetic stirring resulted in no gel formation and in the lowest viscosity of the feed solutions; hence, it is an effective method for preparing hemicellulose feed solutions. sGGM and sGX powders have high heat stability with melting temperatures of 170–180 °C. The sGGM + CMC combination was more stable over 1 week of storage than the sGGM and sGX feed solutions. Storing the feed solutions reduced TAC and increased sGGM viscosity. Our results indicated that GGM and GX have high potential for use as wall materials in the spray-dried microencapsulation of bioactive compounds.

A Comparative Study of Cellulose Ethers as Thermotropic Materials for Self-Tracking Solar Concentrators

The continuous growth in energy demand requires researchers to find new solutions to enlarge and diversify the possible ways of exploiting renewable energy sources. Our idea is the development of a solar concentrator based on trapping the luminous radiation with a smart window. This system is able to direct light towards the photovoltaic cells placed on window borders and produce electricity, without any movable part and without changing its transparency. Herein, we report a detailed study of cellulose ethers, a class of materials of natural origin capable of changing their state, from transparent aqueous solution to scattering hydrogel, in response to a temperature change. Cellulose thermotropism can be used to produce a scattering spot in a window filled with the thermotropic fluid to create a new kind of self-tracking solar concentrator. We demonstrate that the properties of the thermotropic fluid can be finely tuned by selecting the cellulose functionalization, the co-dissolved salt, and by regulating their dosage. Lastly, the results of our investigation are tested in a proof-of-concept demonstration of solar concentration achieved by thermotropism-based light trapping.

A Polysaccharide Isolated from the Herb Bletilla striata Combined with Methylcellulose to Form a Hydrogel via Self-Assembly as a Wound Dressing

The Bletilla striata Polysaccharide (BSP), a natural polysaccharide derived from the east Asian terrestrial orchid Bletilla striata, is an anti-inflammatory, antiviral, and antioxidant polysaccharide. Traditionally, it has been used to treat hemostasis and for wound healing. In this study, BSP was blended with methylcellulose (MC) and methylparaben (MP) to create a hydrogel through a self-assembly route as a wound dressing. The developed hydrogels were designed as M2Bx, M5Bx, and M8Bx. M stands for MC, and the number represents a percentage. Whereas the second letter of B stands for BSP, and x refers to the percentage variation of BSP: x = 0.5%, 1%, and 2%. All the developed MB hydrogels contained β-glucopyranosyl and α-mannopyranosyl, and rheology test had a tan δ value ≥ 0.5. The pore sizes of the hydrogels decreased by increasing the MC and BSP content, and they had better properties with respect to water loss and their swelling ratio. Evaluations in vitro and in vivo showed that all of the developed MB hydrogels have good cell viability and wound-healing properties. The M8B2 hydrogel group was found to be superior to the others from within the developed MB hydrogels. Therefore, we believe that the M8B2 hydrogel formulation has a high potential for development as a wound dressing.