Key advances of carboxymethyl cellulose in tissue engineering & 3D bioprinting applications

Polysaccharide-based implant drug delivery systems for precise therapy: Recent developments, and future trends

Implantable drug delivery systems offer numerous benefits, including effective drug administration at lower concentrations, fewer side effects, and improved patient compliance. Various polymers are used for fabricating implants, with biopolymers, particularly polysaccharides, being notable for their ability to modulate drug delivery characteristics. The review aims to describe the strategies employed in the development of polysaccharide-based implants and provide a comprehensive understanding of various polysaccharides such as starch, cellulose, alginate, chitosan, pullulan, carrageenan, dextran, hyaluronic acid, agar, pectin, and gellan gum in the fabrication of implant for targeted therapy. The review explores the biomedical applications of polysaccharide-based implantable devices, highlighting recent advancements in the development of these systems. Detailed discussions cover implants used in the oral cavity, nasal cavity, bone, ocular applications, and antiviral therapy. Additionally, regulatory considerations concerning implantable drug delivery are emphasized. The findings of the study show that polysaccharides can be used for the development of implants for drug delivery applications.

Multifunctional polydopamine-carboxymethyl cellulose composite gels with Ag/AgCl/ZnO heterojunction to enhance sunlight-responsive photocatalytic activity

Carboxymethyl cellulose (CMC) gel is an ideal substrate for supporting sunlight responsive photocatalysts, but the photocatalytic disinfection activity decreased due to the light-shielding effect of the gel. In order to enhance the formation of active oxygen species, polydopamine (PDA) was introduced in CMC gels to function as an intermediate to connect two semiconductors inside the gels via its quinhydrone charge-transfer complexation. CMC/PDA gel with a double-network was formed via chemical crosslinking and reversible hydrogen bonding between prepolymerized PDA and CMC, then Ag/AgCl, ZnO and Ag/AgCl/ZnO photocatalysts were formed in situ in CMC/PDA gel, respectively. Ag/AgCl/ZnO heterojunction loaded composite gel displayed a remarkable photocatalytic degradation activity, with a weight ratio of the degraded methyl orange divided by composite gels up to 0.00090 under sunlight irradiation for 30 min. Ag/AgCl/ZnO loaded gel presented the bactericidal rate of 99.9 % against E. coli and 99.8 % against S. aureus. The inhibition zone of Ag/AgCl/ZnO loaded composite gel with dopamine mass of 100 mg increased under 6 h of sunlight compared with 24 h in dark against both E. coli and S. aureus. The biocompatible Ag/AgCl/ZnO loaded composite gel with pH-responsive swelling property and sunlight-responsive antibacterial activity promised to broaden the application of CMC-based antibacterial gels.

Study on the barrier properties of carboxymethyl cellulose/montmorillonite mulch films regulated by magnetic field

To enhance the barrier performance of biomass films, carboxymethyl cellulose (CMC) was combined with montmorillonite (MMT) modified by stearyltrimethylammonium bromide (STAB) and loaded with Fe₃O₄ particles as a nano-filler, and a CMC/m-OMMT mulch film was fabricated using magnetic field orientation. The characterization of m-OMMT was conducted through Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM), which confirmed the successful intercalation of STAB into the MMT structure, along with the effective loading of Fe₃O4 particles onto the MMT matrix. A comprehensive investigation into the mechanical properties of CMC/m-OMMT films revealed that, in the dry state, the films exhibited a tensile strength of 29 MPa and an elongation at break of 64 %. A series of barrier performance tests were conducted on the films. The findings demonstrated that the incorporation of MMT and the application of a magnetic field substantially enhanced the water contact angle, increasing it from 86° to 112°. Additionally, water vapor permeability increased by approximately 30 %, soil erosion was reduced by about 22 %, and UV resistance was notably improved by 94 %. Moreover, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and biodegradation tests on the CMC/m-OMMT/40mT films revealed that the magnetic field effectively oriented the MMT nanosheets within the composite matrix. This study presents a novel approach for enhancing the barrier properties of biomass-based mulch films.

All-Cellulose Hydrogel-Based Bioinks for the Versatile 3D Bioprinting of Different Cell Lines

The development of bioink formulations with suitable properties is fundamental for the progress of 3D bioprinting. The potential of cellulose, the most abundant biopolymer, in this realm has often been underestimated, relegating it essentially to a reinforcement additive of bioinks. In this work, cell-laden bioink formulations, composed exclusively of cellulose, viz., "all-cellulose bioinks", were developed by combining carboxymethyl cellulose (CMC) and nanofibrillated cellulose (NFC) in different mass proportions (90/10, 80/20, and 70/30%). The incorporation of NFC increases the printability of the inks (from Pr = 0.7 to 0.9) while maintaining their shear-thinning behavior, and increasing contents of NFC also decrease the degradation rate of the hydrogels after 7 days. The bioprinting of the cell-laden formulations, with HaCaT (keratinocyte) and ATDC5 (chondrogenic) cells, resulted in high (>80%) cell viabilities for up to 7 days, corroborating the versatility of the bioinks and their potential to originate distinct 3D living structures for biomedical applications.

Digital light processing 3D bioprinting of biomimetic corneal stroma equivalent using gelatin methacryloyl and oxidized carboxymethylcellulose interpenetrating network hydrogel

Corneal blindness, a leading cause of visual impairment globally, has created a pressing need for alternatives to corneal transplantation due to the severe shortage of donor tissues. In this study, we present a novel interpenetrating network hydrogel composed of gelatin methacryloyl (GelMA) and oxidized carboxymethyl cellulose (OxiCMC) for bioprinting a biomimetic corneal stroma equivalent. We tested different combinations of GelMA and OxiCMC to optimize printability and subsequently evaluated these combinations using rheological studies for gelation and other physical, chemical, and biological properties. Using digital light processing (DLP) bioprinting, with tartrazine as a photoabsorber, we successfully biofabricated three-dimensional constructs with improved shape fidelity, high resolution, and excellent reproducibility. The bioprinted constructs mimic the native corneal stroma's curvature, with central and peripheral thicknesses of 478.9 ± 56.5µm and 864.0 ± 79.3µm, respectively. The dual crosslinking strategy, which combines Schiff base reaction and photocrosslinking, showed an improved compressive modulus (106.3 ± 7.7 kPa) that closely matched that of native tissues (115.3 ± 13.6 kPa), without relying on synthetic polymers, toxic crosslinkers, or nanoparticles. Importantly, the optical transparency of tartrazine-containing corneal constructs was comparable to the native cornea following phosphate-buffered saline washing. Morphological analyses using scanning electron microscopy confirmed the improved porosity, interconnected network, and structural integrity of the GelMA-OxiCMC hydrogel, facilitating better nutrient diffusion and cell viability.In vitrobiological assays demonstrated high cell viability (>93%) and desirable proliferation of human corneal keratocytes within the biofabricated constructs. Our findings indicate that the GelMA-OxiCMC hydrogel system for DLP bioprinting presents a promising alternative for corneal tissue engineering, offering a potential solution to the donor cornea shortage and advancing regenerative medicine for corneal repair.

Evaluation of Custom Microalgae-Based Bioink Formulations for Optimized Green Bioprinting

Green bioprinting, from the context of merging 3D bioprinting with microalgae cell organization, holds promise for industrial-scale optimization. This study employs spectrophotometric analysis to explore post-bioprinting cell growth density variation within hybrid hydrogel biomaterial scaffolds. Three hydrogel biomaterials-Alginic acid sodium salt (ALGINATE), Nanofibrillated Cellulose (NFC)-TEMPO, and CarboxyMethyl Cellulose (CMC)-are chosen for their scaffolding capabilities. Bioink development and analysis of their impact on cell proliferation and morphology are conducted. Chlorella microalgae cell growth within hydrogel compositions is probed using absorbance measurements, with additional assessment of shear thinning properties. Notably, NFC exhibits reduced shear thinning compared to CMC. Results reveal that while mono-hydrogel substrates with pronounced adhesion inhibit Chlorella cell proliferation, alginate fosters increased cell concentration alongside a slight viscosity rise.

Polymers Derived from Agro-Industrial Waste in the Development of Bioactive Films in Food

This review explores the potential of biopolymers as sustainable alternatives to conventional plastics in food packaging. Biopolymers derived from plant or animal sources are crucial in extending food shelf life, minimizing degradation, and protecting against oxidative and microbial agents. Their physical and chemical properties, influenced by the raw materials used, determine their suitability for specific applications. Biopolymers have been successfully used in fruits, vegetables, meats, and dairy products, offering antimicrobial and antioxidant benefits. Consequently, they represent a functional and eco-friendly solution for the packaging industry, contributing to sustainability while maintaining product quality.

Vat photopolymerization 3D printing optimization: Analysis of print conditions and print quality for complex geometries and ocular applications

3D printing, also known as additive manufacturing, continues to reshape manufacturing paradigms in healthcare by providing customized on-demand object fabrication. However, stereolithography-based 3D printers encounter a conflict between optimizing printing parameters, requiring more time, and print efficiency, requiring less time. Moreover, commonly used metrics to assess shape fidelity of 3D printed hydrogel materials like 'circularity' and 'printability' are limited by the soft nature of hydrogels, that can cause irregularities in their boundary. To unlock the full potential of 3D printing of biomaterials, it is also necessary to understand correlation between printing parameters and ink properties. In this work, a method based on curing depth, overcuring (cumulative cure), and print thickness was developed, which enables a time-efficient and reliable determination of printing conditions for complex geometries using gelatin methacrylate hydrogel biomaterial ink. We also examined the impact of printing direction on the print quality in terms of object/print thickness and aspect ratio. Moreover, the effects of dye concentration, exposure time, and layer thickness on print quality were evaluated, with discussions focused on the correlation between print dimension to layer thickness. Further evaluation was achieved by successfully printing bioinspired corneal stroma-like scaffold and delicate structures like a contact lens and a model eyeball, substantially expanding the scope of this method in producing high-quality prints with intricate details. We also demonstrate the effectiveness of 'Feret ratio,' another measure of object shape, in assessing the shape fidelity of different prints. Overall, the results highlight the practical potential of this method in enhancing the speed and reliability of the 3D printing processes involving complex geometries using a low-cost 3D printers.

An injectable hydrogel of porcine cholecyst extracellular matrix for accelerated wound healing

Hydrogel formulations of xenogeneic extracellular matrices have been widely used for topical wound care because of their exceptional tunability over other formulations like lyophilized sheets, powders, non-injectable gels, pastes, and ointments. This is important in the treatment of wounds with irregular shapes and depth. This study identified an injectable hydrogel formulation of porcine cholecyst extracellular matrix (60%) in medical-grade carboxymethyl cellulose (40%) as vehicle and evaluated its biomaterial properties. Further, an in-depth evaluation of in vivo wound healing efficacy was conducted in a rat full-thickness skin excision wound healing model, which revealed that the hydrogel formulation accelerated wound healing process compared to wounds treated with a commercial formulation and untreated wounds. The hydrogel appeared to have promoted a desirable pro-regenerative tissue reaction predominated by Th2 helper lymphocytes and M2 macrophages as well as an effective collagen remodeling indicative of diminished scarring. In conclusion, the porcine cholecyst extracellular matrix injectable hydrogel formulation appeared to be a promising candidate formulation as an advanced wound care biomaterial for faster healing of skin wounds with minimal scarring.

Highly degradable bio-based plastic with water-assisted shaping process and exceptional mechanical properties

The fabrication of biodegradable and recyclable bio-based plastic by complexing carboxymethyl cellulose (CMC) and cationic polymeric ionic liquid (PILCl) assisted with KNO3 is offered to utilize plastics sustainably and mitigate serious threats to the environment. The CMC/PIL plastic film, formed via electrostatic interactions, exhibits exceptional mechanical properties that surpass those of most conventional plastics. It demonstrates a tensile strength of approximately 200 MPa and a Young's modulus of around 5.5GPa. Even after recycling and regeneration, they essentially retain the original mechanical characteristics with a tensile strength of about 190 MPa. These CMC/PIL plastic films can be processed into three-dimensional (3D) shapes assisted with water and their fundamental qualities maintain after numerous shaping. Besides, they possess excellent biodegradability and can finish biodegrading in a few hours with cellulase and within a few days when exposed to soil. This innovation provides a fresh and practical way to produce degradable plastics.

Multifunctional lanthanum oxide-doped carboxymethyl cellulose nanocomposites: A promising approach for antimicrobial and targeted anticancer applications

This study presents the synthesis and characterization of lanthanum oxide (La₂O₃)-doped carboxymethyl cellulose (CMC) nanocomposites via a solution casting method, designed to offer an eco-friendly, multifunctional material with significant potential in biomedical applications. Structural analysis using FTIR, XRD, and EDX confirmed successful La₂O₃ integration, with FTIR spectra indicating a distinctive LaO stretching peak at 628.2 cm-1, XRD patterns revealing enhanced crystallinity with notable peaks at 16.6°, 27.6°, and 49.8°, and EDX showing a uniform lanthanum distribution with a 10.41 mass% concentration. These enhancements in structural stability and crystalline properties underscore the composite's functional robustness. Biological assessments revealed the composite's substantial antimicrobial efficacy, demonstrating inhibition zones up to 31 mm against pathogenic strains such as E. coli, S. aureus, E. faecalis, K. pneumoniae, and C. albicans at a 15 wt% La₂O₃ concentration-surpassing conventional antimicrobial agents. Minimum inhibitory concentration (MIC) tests supported these findings, showing MIC values as low as 7.82 μg/mL, further validating the composite's heightened antimicrobial potency compared to pure CMC. In vitro cytotoxicity assays indicated selective anticancer effects of the La₂O₃/CMC nanocomposites, with IC₅₀ values of 327.7 μg/mL and 189.8 μg/mL against PC-3 prostate and A549 lung cancer cells, respectively. Remarkably, the composite showed minimal impact on normal lung fibroblasts (Wi-38), with an IC₅₀ value of 956.8 μg/mL, emphasizing its selectivity towards cancer cells. Collectively, these results highlight the La₂O₃/CMC composite as a biocompatible and multifunctional material suitable for both antimicrobial and targeted anticancer applications, aligning with the growing demand for safe, effective biomedical solutions.

Silicified microcrystalline cellulose from renewable banana pseudostem: Physicochemical and functional analysis

Microcrystalline cellulose (MCC) has been isolated from numerous sources through acid hydrolysis of mercerized cellulose. Due to the fibrous shape, its poor flow ability and lower compactibility, MCC is often co-processed with other excipients to improve its functional properties. Musa MCC was isolated from the pseudostem of Musa balbisiana and silicified with 2 % silicon dioxide (SMCC) through homogenization followed by filtration and oven drying. Both Musa MCC and SMCC were thoroughly characterized through FTIR, SEM- EDS, XRD, and TGA-DTG analysis. Detailed pharmaceutical functional properties including packing and rearrangement, consolidation, compressibility, compactibility and tabletability were also investigated and compared against the standard commercial grade MCC. While the percent crystallinity was reduced by silicification, there was enhanced resistance to thermal degradation. By reducing the internal friction, silicification was able to decrease the cohesiveness and improve the flow property of MCC. From Heckel plot and the yield pressure obtained, silicification reduces the extent of plastic deformation of MCC. However, silicification successfully improved the compactibity, tabletability and manufacturability of the Musa MCC. Results from these analyses show that the pseudostem of M balbisiana is a potential sustainable source of highly functional MCC and the silicification process improved the compactibility and tabletability of the MCC.

Enhancing Skin Regeneration Efficacy of Human Dermal Fibroblasts Using Carboxymethyl Cellulose-Coated Biodegradable Polymer

BACKGROUND

Polylactic acid (PLA) is extensively used in the medical and cosmetic industries for skin regeneration and as a dermal filler due to its biocompatibility and biodegradability. However, the effectiveness of PLA as a cosmetic filler is limited by its slow degradation rate and poor cell attachment properties. Recent studies have focused on enhancing the performance of PLA by combining it with other materials. This study aimed to evaluate the performance of carboxymethyl cellulose (CMC), known for its high biocompatibility, in comparison with the widely used hyaluronic acid (HA).

METHODS

Two types of PLA-based particles, HA-PLA and CMC-PLA were synthesized by combining PLA with HA and CMC, respectively. After characterizing the particles, we evaluated cell adhesion and viability using human dermal fibroblasts and analyzed gene and protein expression related to cell attachment and angiogenic paracrine factors.

RESULTS

The CMC-PLA particles maintained a more uniform size distribution than the HA-PLA particles and exhibited superior cell adhesion properties. Cells attached on the CMC-PLA particles showed enhanced secretion of angiogenic paracrine factors, suggesting a potential improvement in therapeutic efficacy.

CONCLUSION

CMC-PLA particles demonstrated superior cell adhesion and secretion capabilities compared with HA-PLA particles, indicating their potential for application in skin regeneration and tissue recovery. Further research, including in vivo studies, is required to fully explore and validate the therapeutic potential of CMC-PLA particles.

CMC/Gel/GO 3D-printed cardiac patches: GO and CMC improve flexibility and promote H9C2 cell proliferation, while EDC/NHS enhances stability

In this research, carboxymethyl cellulose (CMC)/gelatin (Gel)/graphene oxide (GO)-based scaffolds were produced by using extrusion-based 3D printing for cardiac tissue regeneration. Rheological studies were conducted to evaluate the printability of CMC/Gel/GO inks, which revealed that CMC increased viscosity and enhanced printability. The 3D-printed cardiac patches were crosslinked with N-(3-dimethylaminopropyl)-n'-ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS) (100:20 mM, 50:10 mM, 25:5 mM) and then characterized by mechanical analysis, electrical conductivity testing, contact angle measurements and degradation studies. Subsequently, cell culture studies were conducted to evaluate the viability of H9C2 cardiomyoblast cells by using the Alamar Blue assay and fluorescence imaging. A high concentration of EDC/NHS (100:20 mM) led to the stability of the patches; however, it drastically reduced the flexibility of the scaffolds. Conversely, a concentration of 25:5 mM resulted in flexible but unstable scaffolds in phosphate buffer saline solution. The suitable EDC/NHS concentration was found to be 50:10 mM, as it produced flexible, stable, and stiff cardiac scaffolds with high ultimate tensile strength. Mechanical characterization revealed that % strain at break of C15/G7.5/GO1 exhibited a remarkable increase of 61.03% compared to C15/G7.5 samples. The improvement of flexibility was attributed to the hydrogen bonding between CMC, Gel and GO. The electrical conductivity of 3D printed CMC/Gel/GO cardiac patches was 7.0 × 10-3S cm-1, demonstrating suitability for mimicking the desired electrical conductivity of human myocardium. The incorporation of 1 wt% of GO and addition of CMC concentration from 7.5 wt% to 15 wt% significantly enhanced relative % cell viability. Overall, although this research is at its infancy, CMC/Gel/GO cardiac patches have potential to improve the physiological function of cardiac tissue.

Cellulose processing using ionic liquids: An analysis of patents and technological trends

The production of cellulose derivatives using ionic liquid (IL) as solvents and catalysts has become prominent over the last few years, since the process eliminates the use of toxic substances. This study aimed to map and understand the trends in cellulose processing using ILs by a patent analytic approach and technology life cycle modeling. The documents were searched on the Espacenet® and Orbit® platforms.The majority of innovations have come from companies based in developed countries. The data fitted to the sigmoid BiDoseResp model and the life cycle S-curve showed a market in an early stage of maturity. This mapping brings information that subsidizes decision-making regarding investments, research, and innovations aimed at IL-mediated cellulose treatment. Potential markets mostly use ILs of the imidazolium family in polymer chemistry, machinery, and biotechnology technologies. However, medical and pharmaceutical technologies and microstructure and nanostructure applications are still emerging, fostering perspectives for innovation.

A particle-filled hydrogel based on alginate and calcium phosphate nanoparticles as bone adhesive

The clinical need for bone adhesives as an alternative to osteosynthesis is evident. However, this is a challenging problem due to the moist environment in surgical sites with bone surfaces covered with blood and biomolecules like lipids or proteins. A nanoparticle-loaded hydrogel that is based on a freeze-dried powder of silica-coated calcium phosphate/carboxymethyl cellulose nanoparticles (CaP/CMC/SiO2) and an aqueous solution of sodium alginate (2 wt%) was developed and optimized with respect to the gluing ability in air and in water. The final paste was crosslinked within about one minute by calcium ions released from the calcium phosphate nanoparticles and contained about 20 wt% nanoparticles and 80 wt% water. The mechanical properties of the hydrogel were determined by extensive rheological tests. The thixotropic pasty hydrogel can be applied with a syringe. The adhesion strength was about 84 kPa between moist bone fragments in air. The hydrogel kept fragments of cortical bone well connected for >3 months during complete submersion in water. Besides water, the material consists only of biocompatible and biodegradable components (calcium phosphate, CMC, alginate). It carries only a very low dose of these materials into the bone site (mainly calcium phosphate nanoparticles). In-vitro cell culture with hMSCs that differentiated to osteoblasts confirmed a good biocompatibility of the bone adhesive formulation.

Silver and Copper Nanoparticles Hosted by Carboxymethyl Cellulose Reduce the Infective Effects of Enterotoxigenic Escherichia coli:F4 on Porcine Intestinal Enterocyte IPEC-J2

Zero-valent copper and silver metals (Ms) nanoparticles (NPs) supported on carboxymethylcellulose (CMC) were synthesized for treating Enterotoxigenic Escherichia coli fimbriae 4 (ETEC:F4), a major cause of diarrhea in post-weaned pigs. The antibacterial properties of Cu0/CMC and Ag0/CMC were assessed on infected porcine intestinal enterocyte IPEC-J2, an in vitro model mimicking the small intestine. The lower average particle size (218 nm) and polydispersity index [PDI]: 0.25) for Ag0/CMC, when compared with those of Cu0/CMC (367 nm and PDI 0.96), were explained by stronger Ag0/CMC interactions. The minimal inhibitory concentration (MIC) and half inhibitory concentration (IC50) of Ag0/CMC were lower in both bacteria and IPEC-J2 cells than those of Cu0/CMC, confirming that silver nanoparticles are more bactericidal than copper counterparts. IPEC-J2, less sensitive in MNP/CMC treatment, was used to further investigate the infective process by ETEC:F4. The IC50 of MNP/CMC increased significantly when infected IPEC-J2 cells and ETEC were co-treated, showing an inhibition of the cytotoxicity effect of ETEC:F4 infection and protection of treated IPEC-J2. Thus, it appears that metal insertion in CMC induces an inhibiting effect on ETEC:F4 growth and that MNP/CMC dispersion governs the enhancement of this effect. These results open promising prospects for metal-loaded biopolymers for preventing and treating swine diarrhea.

Green stabilization of silver nanoparticles over the surface of biocompatible Fe3O4@CMC for bactericidal applications

The emergence of antimicrobial resistance in bacteria, especially in agents associated with urinary tract infections (UTIs), has initiated an exciting effort to develop biocompatible nanoparticles to confront their threat. Designing simple, cheap, biocompatible, and efficient nanomaterials as bactericidal agents seems to be a judicious response to this problem. Here, a solvothermal method was hired for the one-pot preparation of the cellulose gum (carboxymethyl cellulose, CMC) magnetic composite to prepare a cost-effective, efficient, and biocompatible support for the plant-based stabilization of the silver NPs. The green stabilization of the Ag NPs is performed using Euphorbia plant extract with high efficiency. Various characterization methods, including FT-IR, XRD, SEM, EDS, TEM, and VSM were used to study the composition and properties of Fe3O4@CMC/AgNPs. The composite shows well integrity and monodispersity with a mean diameter of <300 nm, indicating its potential for bio-related application. The CMC functionalities of the proposed material facilitated the stabilization of the Ag NPs, resulting in their monodispersity and enhanced performance. The manufactured composite was used as an antibacterial agent for the removal of UTIs agents, collected from 200 hospitalized patients with acute coronary syndrome, which showed promising results. This study showed that the concentration of the Ag NPs has a direct relationship with the antibacterial properties of the composite.

Delivery of natural products via polysaccharide-based nanocarriers for cancer therapy: A review on recent advances and future challenges

Cancer, caused by uncontrolled proliferation of abnormal cells, has long been a global public health issue. For decades, natural products have been proven to be an essential source for novel anticancer drug discovery. But their instability, low solubility and bioavailability, poor targeting impede therapeutic efficacy. With the development of nanotechnology, nanomedicine delivery systems have emerged as promising strategies to improve bioavailability and enhance the therapeutic efficacy of drugs. However, constructing suitable nanocarrier is still a major challenge. Polysaccharides are extensively employed as carrier materials in nanomedicine delivery systems, owing to their unique physicochemical properties, biocompatibility and low immunogenicity. Polysaccharide-based nanomedicine delivery systems show high drug delivery efficiency, controlled drug release, and precise tumor targeting. This paper reviews influencing factors in the construction of polysaccharide-based nanocarriers and the application of polysaccharide-based nanocarriers for the delivery of natural products in treating various cancers. It focuses on their in vitro and in vivo anticancer efficacy and mechanisms. Furthermore, the review contrasts the capabilities and limitations of polysaccharide-based nanocarriers with traditional delivery methods, underlining their potential to enable targeted, reduced toxicity and excellent cancer treatment modalities. Finally, we discuss the current research limitations and future prospects in this emerging field.

Development of hybrid polyvinylpyrrolidone/carboxymethyl cellulose/collagen incorporated oregano scaffolds via direct ink write printing for potential wound healing applications

Additive manufacturing can develop regenerative scaffolds for wound healing. 3D printing offers meticulous porosity, mechanical integrity, cell adhesion and cost-effectiveness. Herein, we prepared ink composed of carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP), collagen, and oregano extract for the fabrication of tissue constructs. The blend was optimized to form a homogeneous ink and rheological characterization demonstrated shear thinning behavior. The scaffolds were printed using Direct Ink Write (DIW) at a flow speed of 4 mm3/s and a layer height of 0.18 mm. The fabricated scaffolds demonstrated an ultimate tensile strength (UTS) and toughness of 730 KPa and 2.72 MJ/m3, respectively. Scanning Electron Microscopy (SEM) revealed an average pore size of 300 ± 30 μm. Fourier transform infrared spectroscopy (FTIR) analysis confirmed that all materials were present. The contact angle of the composite scaffold was 68° ± 1°. Moreover, the scaffolds presented 82 % mass loss (degradation) in phosphate buffer saline (PBS) over 14 days. The composite scaffold exhibited inhibition zones of 9 mm and 12 mm against Staphylococcus aureus and Escherichia coli, respectively. The PVP/CMC/collagen/oregano 3D printed scaffolds exhibited excellent biocompatibility with the mesenchymal stem cells and humman dermal fibroblast cells, confirmed by water-soluble tetrazolium - 8 (WST-8) assay (test conducted for 7 days). The enhanced angiogenic potential of said scaffold was assesed by release of vascular endothelial growth factor followed by further validation through in-vivo CAM assay. Thus, confirming suitability for the potential wound healing application.

Engineered Microfibers for Tissue Engineering

Hydrogel microfibers are hydrogel materials engineered into fiber structures. Techniques such as wet spinning, microfluidic spinning, and 3D bioprinting are often used to prepare microfibers due to their ability to precisely control the size, morphology, and structure of the microfibers. Microfibers with different structural morphologies have different functions; they provide a flow-through culture environment for cells to improve viability, and can also be used to induce the differentiation of cells such as skeletal muscle and cardiac muscle cells to eventually form functional organs in vitro through special morphologies. This Review introduces recent advances in microfluidics, 3D bioprinting, and wet spinning in the preparation of microfibers, focusing on the materials and fabrication methods. The applications of microfibers in tissue engineering are highlighted by summarizing their contributions in engineering biomimetic blood vessels, vascularized tissues, bone, heart, pancreas, kidney, liver, and fat. Furthermore, applications of engineered fibers in tissue repair and drug screening are also discussed.

Mechanically Adaptive Metal-Coordinated Electrogel Membranes

Achieving specific mechanical properties of hydrogels, especially when used as thin films, can be crucial in diverse applications, including tissue engineering and bioelectronics. Here, a novel electrochemical approach for fabricating uniform and robust hydrogel films based on carboxymethyl cellulose cross-linked by Fe3+ ions (Fe-CMC), exhibiting tunable, dynamic properties is introduced. High modulation of the mechanical properties of the film is achieved by applying multiple electrochemical pulses of oxidative voltage during hydrogel deposition. Our study shows also a remarkable effect of the ionic strength on the properties of the electrodeposited hydrogel films. We found that switching from a salt solution to water enhanced the stiffness of the hydrogels, thereby regulating the permeability of the films. These results are supported by molecular dynamics (MD) simulations, showing that an increase in the ionic strength induces a weakening of the Fe-CMC interactions, ultimately affecting the network strength. Finally, the robustness of these electrodeposited hydrogel films enables their delamination from the electrode without any damage, thereby expanding their potential applications as freestanding smart membranes. By providing fundamental insights into the dynamics of metal-coordinated bonds and their response at the macroscopic scale, we have demonstrated the versatility of electrochemical gelation for the fabrication of robust hydrogel films with tunable mechanical properties, which could serve as smart platforms for a variety of biomedical applications.

The potential of carboxylmethyl cellulose from empty fruit bunch as versatile material in food coating: A review

The rising demand for food packaging has led to a growing interest in sustainable and eco-friendly food coatings. Carboxymethyl cellulose (CMC), being a versatile cellulose derivative produced from various lignocellulosic sources, has emerged in edible food coatings. This review evaluates the research trends on CMC production from empty fruit bunch (EFB) as a potential edible food coating material by systematic review approach. It explores sustainable pre-treatment for green cellulose and different CMC synthesis methods. The review compares CMC-based coatings to other materials, focusing on formulation processes, coating quality, safety, and commercial feasibility. The bibliometric analysis is performed to correlate food coating and CMC. As a result, the study discovered the rapid growth in research on edible food coatings made from CMC for various food industry applications. The green approach such as ozone pre-treatment appear as promising method for cellulose isolation from EFB to be used as raw material for CMC. The synthesis conditions of the treatment would affect the CMC characteristics and usage. Herein, utilizing CMC from cellulose EFB in coating formulation and on coated food shows different benefits. This review provides a road map for future research with potential to make important contributions to the food industry's long-term evolution.

The role of glycerol in manufacturing freeze-dried chitosan and cellulose foams for mechanically stable scaffolds in skin tissue engineering

Various strategies have extensively explored enhancing the physical and biological properties of chitosan and cellulose scaffolds for skin tissue engineering. This study presents a straightforward method involving the addition of glycerol into highly porous structures of two polysaccharide complexes: chitosan/carboxymethyl cellulose (Chit/CMC) and chitosan/oxidized cellulose (Chit/OC); during a one-step freeze-drying process. Adding glycerol, especially to Chit/CMC, significantly increased stability, prevented degradation, and improved mechanical strength by nearly 50%. Importantly, after 21 days of incubation in enzymatic medium Chit/CMC scaffold has almost completely decomposed, while foams reinforced with glycerol exhibited only 40% mass loss. It is possible due to differences in multivalent cations and polymer chain contraction, resulting in varied hydrogen bonding and, consequently, distinct physicochemical outcomes. Additionally, the scaffolds with glycerol improved the cellular activities resulting in over 40% higher proliferation of fibroblast after 21 days of incubation. It was achieved by imparting water resistance to the highly absorbent material and aiding in achieving a balance between hydrophilic and hydrophobic properties. This study clearly indicates the possible elimination of additional crosslinkers and multiple fabrication steps that can reduce the cost of scaffold production for skin tissue engineering applications while tailoring mechanical strength and degradation.

Characterization and Comparative Investigation of Hydroxyapatite/Carboxymethyl Cellulose (CaHA/CMC) Matrix for Soft Tissue Augmentation in a Rat Model

This study endeavors to develop an injectable subdermal implant material tailored for soft tissue repair and enhancement. The material consists of a ceramic phase of calcium hydroxyapatite (CaHA), which is biocompatible, 20-60 μm in size, known for its biocompatibility and minimal likelihood of causing foreign body reactions, antigenicity, and minimal inflammatory response, dispersed in a carrier phase composed of carboxymethyl cellulose (CMC), glycerol, and water for injection. The gel formulation underwent comprehensive characterization via various analytical techniques. X-ray diffraction (XRD) was employed to identify crystalline phases and investigate the structural properties of ceramic particles, while thermogravimetric analysis (TGA) was conducted to evaluate the thermal stability and decomposition behavior of the final formulation. Scanning electron microscopy (SEM) was utilized to examine the surface morphology and particle size distribution, confirming the homogeneous dispersion of spherical CaHA particles within the matrix. SEM analysis revealed particle sizes ranging from approximately 20-60 μm. Elemental analysis confirmed a stoichiometric Ca/P ratio of 1.65 in the hydroxyapatite (HA) structure. Heavy metal content exhibited suitability for surgical implant use without posing toxicity risks. Rheological analysis revealed a storage modulus of 58.6 and 68.9 kPa and a loss modulus of 21.7 and 24.8 kPa at the frequencies of 2 and 5 Hz, respectively. 150 μL of sterilized CaHA/CMC was injected subcutaneously into rats and compared with a similar product, Crystalys, to assess its effects on soft tissues. Skin tissue samples of rats were collected at specific intervals throughout the study (30, 45, 60, 90 and 120 days), and examined histologically. Results demonstrated that CaHA/CMC gel led to a significant increase in dermal thickness, elastic fibers, and collagen density. Based on the findings, the formulated CaHA/CMC gel was found to be biocompatible, biodegradable, nonimmunogenic, nontoxic, safe, and effective, and represents a promising option for soft tissue repair and augmentation.

Development of novel iron(III) crosslinked bioinks comprising carboxymethyl cellulose, xanthan gum, and hyaluronic acid for soft tissue engineering applications

The advent of three-dimensional (3D) bioprinting offers a feasible approach to construct complex structures for soft tissue regeneration. Carboxymethyl cellulose (CMC) has been emerging as a very promising biomaterial for 3D bioprinting. However, due to the inability to maintain the post-printed stability, CMC needs to be physically blended and/or chemically crosslinked with other polymers. In this context, this study presents the combination of CMC with xanthan gum (XG) and hyaluronic acid (HA) to formulate a multicomponent bioink, leveraging the printability of CMC and XG, as well as the cellular support properties of HA. The ionic crosslinking of printed constructs with iron(III) via the metal-ion coordination between ferric cations and carboxylate groups of the three polymers was introduced to induce improved mechanical strength and long-term stability. Moreover, immortalized human epidermal keratinocytes (HaCaT) and human foreskin fibroblasts (HFF) encapsulated within iron-crosslinked printed hydrogels exhibited excellent cell viability (more than 95%) and preserved morphology. Overall, the presented study highlights that the combination of these three biopolymers and the ionic crosslinking with ferric ions is a valuable strategy to be considered for the development of new and advanced hydrogel-based bioinks for soft tissue engineering applications.

Design of Carboxymethylcellulose/Poloxamer-Based Bioformulation Embedding Trichoderma afroharzianum for Agricultural Applications

Microbial biological control agents are believed to be a potential alternative to classical fertilizers to increase the sustainability of agriculture. In this work, the formulation of Trichoderma afroharzianum T22 (T22) spores with carboxymethyl cellulose (CMC) and Pluronic F-127 (PF-127) solutions was investigated. Rheological and microscopical analysis were performed on T22-based systems at three different CMC/PF-127 concentrations, showing that polymer aggregates tend to surround T22 spores, without viscosity, and the viscoelastic properties of the formulations were affected. Contact angle measurements showed the ability of PF-127 to increase the wettability of the systems, and the effect of the formulations on the viability of the spores was evaluated. The viability of the spores was higher over 21 days in all the formulations, compared to the control in water, at 4 and 25 °C. Finally, the effectiveness of the formulations on sweet basil was estimated by greenhouse tests. The results revealed a beneficial effect of the CMC/PF-127 mixture, but none on the formulation with T22. The data show the potential of CMC/PF-127 mixtures for the future design of microorganism-based formulations.

Fabrication of k-Carrageenan/Alginate/Carboxymethyl Cellulose basedScaffolds via 3D Printing for Potential Biomedical Applications

Three-dimensional (3D) printing technology was able to generate great attention because of its unique methodology and for its major potential to manufacture detailed and customizable scaffolds in terms of size, shape and pore structure in fields like medicine, pharmaceutics and food. This study aims to fabricate an ink entirely composed of natural polymers, alginate, k-carrageenan and carboxymethyl cellulose (AkCMC). Extrusion-based 3D printing was used to obtain scaffolds based on a crosslinked interpenetrating polymer network from the alginate, k-carrageenan, carboxymethyl cellulose and glutaraldehide formulation using CaCl2, KCl and glutaraldehyde in various concentrations of acetic acid. The stabile bonding of the crosslinked scaffolds was assessed using infrared spectroscopy (FT-IR) as well as swelling, degradation and mechanical investigations. Moreover, morphology analysis (µCT and SEM) confirmed the 3D printed samples' porous structure. In the AkCMC-GA objects crosslinked with the biggest acetic acid concentration, the values of pores and walls are the highest, at 3.9 × 10-2 µm-1. Additionally, this research proves the encapsulation of vitamin B1 via FT-IR and UV-Vis spectroscopy. The highest encapsulation efficiency of vitamin B1 was registered for the AkCMC-GA samples crosslinked with the maximum acetic acid concentration. The kinetic release of the vitamin was evaluated by UV-Vis spectroscopy. Based on the results of these experiments, 3D printed constructs using AkCMC-GA ink could be used for soft tissue engineering applications and also for vitamin B1 encapsulation.

Preparation of an injectable and photocurable carboxymethyl cellulose/hydroxyapatite composite and its application in cranial regeneration

Limited bone regeneration, uncontrollable degradation rate, mismatched defect zone and poor operability have plagued the reconstruction of irregular bone defect by tissue-engineered materials. A combination of biomimetic scaffolds with hydroxyapatite has gained great popularity in promoting bone regeneration. Therefore, we designed an injectable, photocurable and in-situ curing hydrogel by methacrylic anhydride -modified carboxymethyl cellulose (CMC-MA) loading with spherical hydroxyapatite (HA) to highly simulate the natural bony matrix and match any shape of damaged tissue. The prepared carboxymethyl cellulose-methacrylate/ hydroxyapatite(CMC-MA/HA) composite presented good rheological behavior, swelling ratio and mechanical property under light illumination. Meanwhile, this composite hydrogel promoted effectively proliferation, supported adhesion and upregulated the osteogenic-related genes expression of MC3T3-E1 cells in vitro, as well as the activity of the osteogenic critical protein, Integrin α1, β1, Myosin 9, Myosin 10, BMP-2 and Smad 1 in Integrin/BMP-2 signal pathway. Together, the composite hydrogels realized promotion of bone regeneration, deformity improvement, and the enhanced new bone strength in skull defect. It also displayed a good histocompatibility and stability of subcutaneous implantation in vivo. Overall, this study laid the groundwork for future research into developing a novel biomaterial and a minimally invasive therapeutic strategies for reconstructing bone defects and contour deficiencies.

Functionally graded hydrogels with opposing biochemical cues for osteochondral tissue engineering

Osteochondral tissue (OC) repair remains a significant challenge in the field of musculoskeletal tissue engineering. OC tissue displays a gradient structure characterized by variations in both cell types and extracellular matrix components, from cartilage to the subchondral bone. These functional gradients observed in the native tissue have been replicated to engineer OC tissuein vitro. While diverse fabrication methods have been employed to create these microenvironments, emulating the natural gradients and effective regeneration of the tissue continues to present a significant challenge. In this study, we present the design and development of CMC-silk interpenetrating (IPN) hydrogel with opposing dual biochemical gradients similar to native tissue with the aim to regenerate the complete OC unit. The gradients of biochemical cues were generated using an in-house-built extrusion system. Firstly, we fabricated a hydrogel that exhibits a smooth transition of sulfated carboxymethyl cellulose (sCMC) and TGF-β1 (SCT gradient hydrogel) from the upper to the lower region of the IPN hydrogel to regenerate the cartilage layer. Secondly, a hydrogel with a hydroxyapatite (HAp) gradient (HAp gradient hydrogel) from the lower to the upper region was fabricated to facilitate the regeneration of the subchondral bone layer. Subsequently, we developed a dual biochemical gradient hydrogel with a smooth transition of sCMC + TGF-β1 and HAp gradients in opposing directions, along with a blend of both biochemical cues in the middle. The results showed that the dual biochemical gradient hydrogels with biochemical cues corresponding to the three zones (i.e. cartilage, interface and bone) of the OC tissue led to differentiation of bone-marrow-derived mesenchymal stem cells to zone-specific lineages, thereby demonstrating their efficacy in directing the fate of progenitor cells. In summary, our study provided a simple and innovative method for incorporating gradients of biochemical cues into hydrogels. The gradients of biochemical cues spatially guided the differentiation of stem cells and facilitated tissue growth, which would eventually lead to the regeneration of the entire OC tissue with a smooth transition from cartilage (soft) to bone (hard) tissues. This promising approach is translatable and has the potential to generate numerous biochemical and biophysical gradients for regeneration of other interface tissues, such as tendon-to-muscle and ligament-to-bone.

Low-Concentration Gelatin Methacryloyl Hydrogel with Tunable 3D Extrusion Printability and Cytocompatibility: Exploring Quantitative Process Science and Biophysical Properties

Three-dimensional (3D) bioprinting of hydrogels with a wide spectrum of compositions has been widely investigated. Despite such efforts, a comprehensive understanding of the correlation among the process science, buildability, and biophysical properties of the hydrogels for a targeted clinical application has not been developed in the scientific community. In particular, the quantitative analysis across the entire developmental path for 3D extrusion bioprinting of such scaffolds is not widely reported. In the present work, we addressed this gap by using widely investigated biomaterials, such as gelatin methacryloyl (GelMA), as a model system. Using extensive experiments and quantitative analysis, we analyzed how the individual components of methacrylated carboxymethyl cellulose (mCMC), needle-shaped nanohydroxyapatite (nHAp), and poly(ethylene glycol)diacrylate (PEGDA) with GelMA as baseline matrix of the multifunctional bioink can influence the biophysical properties, printability, and cellular functionality. The complex interplay among the biomaterial ink formulations, viscoelastic properties, and printability toward the large structure buildability (structurally stable cube scaffolds with 15 mm edge) has been explored. Intriguingly, the incorporation of PEGDA into the GelMA/mCMC matrix offered improved compressive modulus (∼40-fold), reduced swelling ratio (∼2-fold), and degradation rates (∼30-fold) compared to pristine GelMA. The correlation among microstructural pore architecture, biophysical properties, and cytocompatibility is also established for the biomaterial inks. These photopolymerizable bio(material)inks served as the platform for the growth and development of bone and cartilage matrix when human mesenchymal stem cells (hMSCs) are either seeded on two-dimensional (2D) substrates or encapsulated on 3D scaffolds. Taken together, this present study unequivocally establishes a significant step forward in the development of a broad spectrum of shape-fidelity compliant bioink for the 3D bioprinting of multifunctional scaffolds and emphasizes the need for invoking more quantitative analysis in establishing process-microstructure-property correlation.

Gelatin Methacryloyl (GelMA)-Based Biomaterial Inks: Process Science for 3D/4D Printing and Current Status

Tissue engineering for injured tissue replacement and regeneration has been a subject of investigation over the last 30 years, and there has been considerable interest in using additive manufacturing to achieve these goals. Despite such efforts, many key questions remain unanswered, particularly in the area of biomaterial selection for these applications as well as quantitative understanding of the process science. The strategic utilization of biological macromolecules provides a versatile approach to meet diverse requirements in 3D printing, such as printability, buildability, and biocompatibility. These molecules play a pivotal role in both physical and chemical cross-linking processes throughout the biofabrication, contributing significantly to the overall success of the 3D printing process. Among the several bioprintable materials, gelatin methacryloyl (GelMA) has been widely utilized for diverse tissue engineering applications, with some degree of success. In this context, this review will discuss the key bioengineering approaches to identify the gelation and cross-linking strategies that are appropriate to control the rheology, printability, and buildability of biomaterial inks. This review will focus on the GelMA as the structural (scaffold) biomaterial for different tissues and as a potential carrier vehicle for the transport of living cells as well as their maintenance and viability in the physiological system. Recognizing the importance of printability toward shape fidelity and biophysical properties, a major focus in this review has been to discuss the qualitative and quantitative impact of the key factors, including microrheological, viscoelastic, gelation, shear thinning properties of biomaterial inks, and printing parameters, in particular, reference to 3D extrusion printing of GelMA-based biomaterial inks. Specifically, we emphasize the different possibilities to regulate mechanical, swelling, biodegradation, and cellular functionalities of GelMA-based bio(material) inks, by hybridization techniques, including different synthetic and natural biopolymers, inorganic nanofillers, and microcarriers. At the close, the potential possibility of the integration of experimental data sets and artificial intelligence/machine learning approaches is emphasized to predict the printability, shape fidelity, or biophysical properties of GelMA bio(material) inks for clinically relevant tissues.

Carboxymethyl cellulose-agarose hydrogel in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanofibers: A novel tissue engineered skin graft

Healing chronic and critical-sized full-thickness wounds is a major challenge in the healthcare sector. Scaffolds prepared using electrospinning and hydrogels serve as effective treatment options for wound healing by mimicking the native skin microenvironment. Combining synthetic nanofibers with tunable hydrogel properties can effectively overcome limitations in skin scaffolds made only with nanofibers or hydrogels. In this study, a biocompatible hybrid scaffold was developed for wound healing applications using poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers embedded with hydrogel made of 2 % carboxymethyl cellulose (CMC) blended with 1 % agarose. Hybrid scaffolds, characterized for surface morphology, swellability, porosity, and degradation, were found to be suitable for wound healing. Furthermore, the incorporation of CMC-agarose hydrogel into nanofibers significantly enhanced their mechanical strength compared to PHBV nanofibers alone (p < 0.05). Extract cytotoxicity and direct cytotoxicity tests showed that the hybrid scaffolds developed in this study are cytocompatible (>75 % viability). Furthermore, human adult dermal fibroblasts (HDFa) and human adult immortalized keratinocytes (HaCaT) adhesion, viability, and proliferation studies revealed that the hybrid scaffolds exhibited a significant increase in cell proliferation over time, similar to PHBV nanofibers. Finally, the developed hybrid scaffolds were evaluated in rat full-thickness wounds, demonstrating their ability to promote full-thickness wound healing with reepithelialization and epidermis closure.

Evolution of Hybrid Hydrogels: Next-Generation Biomaterials for Drug Delivery and Tissue Engineering

Hydrogels, being hydrophilic polymer networks capable of absorbing and retaining aqueous fluids, hold significant promise in biomedical applications owing to their high water content, permeability, and structural similarity to the extracellular matrix. Recent chemical advancements have bolstered their versatility, facilitating the integration of the molecules guiding cellular activities and enabling their controlled activation under time constraints. However, conventional synthetic hydrogels suffer from inherent weaknesses such as heterogeneity and network imperfections, which adversely affect their mechanical properties, diffusion rates, and biological activity. In response to these challenges, hybrid hydrogels have emerged, aiming to enhance their strength, drug release efficiency, and therapeutic effectiveness. These hybrid hydrogels, featuring improved formulations, are tailored for controlled drug release and tissue regeneration across both soft and hard tissues. The scientific community has increasingly recognized the versatile characteristics of hybrid hydrogels, particularly in the biomedical sector. This comprehensive review delves into recent advancements in hybrid hydrogel systems, covering the diverse types, modification strategies, and the integration of nano/microstructures. The discussion includes innovative fabrication techniques such as click reactions, 3D printing, and photopatterning alongside the elucidation of the release mechanisms of bioactive molecules. By addressing challenges, the review underscores diverse biomedical applications and envisages a promising future for hybrid hydrogels across various domains in the biomedical field.

Tuning thermoresponsive properties of carboxymethyl cellulose (CMC)-agarose composite bioinks to fabricate complex 3D constructs for regenerative medicine

3D bioprinting has emerged as a viable tool to fabricate 3D tissue constructs with high precision using various bioinks which offer instantaneous gelation, shape fidelity, and cytocompatibility. Among various bioinks, cellulose is the most abundantly available natural polymer & widely used as bioink for 3D bioprinting applications. To mitigate the demanding crosslinking needs of cellulose, it is frequently chemically modified or blended with other polymers to develop stable hydrogels. In this study, we have developed a thermoresponsive, composite bioink using carboxymethyl cellulose (CMC) and agarose in different ratios (9:1, 8:2, 7:3, 6:4, and 5:5). Among the tested combinations, the 5:5 ratio showed better gel formation at 37 °C and were further characterized for physicochemical properties. Cytocompatibility was assessed by in vitro extract cytotoxicity assay (ISO 10993-5) using skin fibroblasts cells. CMC-agarose (5:5) bioink was successfully used to fabricate complex 3D structures through extrusion bioprinting and maintained over 80 % cell viability over seven days. Finally, in vivo studies using rat full-thickness wounds showed the potential of CMC-agarose bulk and bioprinted gels in promoting skin regeneration. These results indicate the cytocompatibility and suitability of CMC-agarose bioinks for tissue engineering and 3D bioprinting applications.

Embedded 3D bioprinting - An emerging strategy to fabricate biomimetic & large vascularized tissue constructs

Three-dimensional bioprinting is an advanced tissue fabrication technique that allows printing complex structures with precise positioning of multiple cell types layer-by-layer. Compared to other bioprinting methods, extrusion bioprinting has several advantages to print large-sized tissue constructs and complex organ models due to large build volume. Extrusion bioprinting using sacrificial, support and embedded strategies have been successfully employed to facilitate printing of complex and hollow structures. Embedded bioprinting is a gel-in-gel approach developed to overcome the gravitational and overhanging limits of bioprinting to print large-sized constructs with a micron-scale resolution. In embedded bioprinting, deposition of bioinks into the microgel or granular support bath will be facilitated by the sol-gel transition of the support bath through needle movement inside the granular medium. This review outlines various embedded bioprinting strategies and the polymers used in the embedded systems with advantages, limitations, and efficacy in the fabrication of complex vascularized tissues or organ models with micron-scale resolution. Further, the essential requirements of support bath systems like viscoelasticity, stability, transparency and easy extraction to print human scale organs are discussed. Additionally, the organs or complex geometries like vascular constructs, heart, bone, octopus and jellyfish models printed using support bath assisted printing methods with their anatomical features are elaborated. Finally, the challenges in clinical translation and the future scope of these embedded bioprinting models to replace the native organs are envisaged.

Recent advances in carboxymethyl cellulose-based active and intelligent packaging materials: A comprehensive review

Researchers have concentrated on innovative approaches to increase the shelf life of perishable food products and monitor their quality during storage and transportation as consumer demand for safe, environmentally friendly, and effective packaging develops. This comprehensive review aims to provide an overview of recent developments in carboxymethyl cellulose (CMC) chemical synthesis and its applications in active and intelligent packaging materials. It explores various methods for modifying cellulose to produce CMC and highlights the unique properties that make it suitable for addressing packaging industry challenges. The integration of CMC into active packaging systems, which helps reduce food waste and enhance food preservation, is discussed in depth. Furthermore, the integration of CMC in smart sensors and indicators for real-time monitoring and quality assurance in intelligent packaging is examined. The chemical synthesis of CMC and strategies to optimise its properties were studied, and the review concluded by examining the challenges and prospects of CMC-based packaging in the industry. This review is intended to serve as a valuable resource for researchers, industry professionals, and policymakers interested in the evolving landscape of CMC and its role in shaping the future of packaging materials.

Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

Microfluidic Preparation of pH-Responsive Microsphere Fibers and Their Controlled Drug Release Properties

In this study, a capillary microfluidic device was constructed, and sodium alginate solution and a pH-sensitive hydrophobic polymer (p(BMA-co-DAMA-co-MMA)) solution were introduced into the device for the preparation of hydrogel fibers loaded with polymer microspheres. The structure of the microsphere fiber, including the size and spacing of the microspheres, could be controlled by flow rate, and the microspheres were able to degrade and release cargo responding to acidic pH conditions. By modification with carboxymethylcellulose (CMC), alginate hydrogel exhibited enhanced pH sensitivity (shrunk in acidic while swollen in basic condition). This led to an impact on the diffusion rate of the molecules released from the inner microspheres. The microsphere fiber showed dramatic and negligible degradation and drug release in tumor cell (i.e., A431 and A549 cells) and normal cell environments, respectively. These results indicated that the microsphere fiber prepared in this study showed selective drug release in acidic environments, such as tumor and inflammation sites, which could be applied as a smart surgical dressing with normal tissue protective properties.

Recent advances in 3D printed cellulose-based wound dressings: A review on in vitro and in vivo achievements

Chronic wounds, especially diabetic ulcers, pose a significant challenge in regenerative medicine. Cellulose derivatives offer remarkable wound management properties, such as effective absorption and retention of wound exudates, maintaining an optimal moisture environment crucial for successful chronic wound regeneration. However, conventional dressings have limited efficacy in managing and healing these types of skin lesions, driving scientists to explore innovative approaches. The emergence of 3D printing has enabled personalized dressings that meet individual patient needs, improving the healing process and patient comfort. Cellulose derivatives meet the demanding requirements for biocompatibility, printability, and biofabrication necessary for 3D printing of biologically active scaffolds. However, the potential applications of nanocellulose and cellulose derivative-based inks for wound regeneration remain largely unexplored. Thus, this review provides a comprehensive overview of recent advancements in cellulose-based inks for 3D printing of personalized wound dressings. The composition and biofabrication approaches of cellulose-based wound dressings are thoroughly discussed, including the functionalization with bioactive molecules and antibiotics for improved wound regeneration. Similarly, the in vitro and in vivo performance of these dressings is extensively examined. In summary, this review aims to highlight the exceptional advantages and diverse applications of 3D printed cellulose-based dressings in personalized wound care.

Tunable, thiol-ene, interpenetrating network hydrogels of norbornene-modified carboxymethyl cellulose and cellulose nanofibrils

Carboxymethyl cellulose modified with norbornene groups (NorCMC) and cellulose nanofibrils (CNFs) produced through mechanical refining without chemical pretreatment formed interpenetrating network hydrogels through a UV-light initiated thiol-ene reaction. The molar ratio of thiols in crosslinkers to norbornene groups off the NorCMC (T:N), total polymer weight percent in the hydrogel, and weight percent of CNFs of the total polymer content of the hydrogels were varied to control hydrogel properties. This method enabled orders of magnitude changes to behavior. Swelling in aqueous environments could be significant (>150 %) without CNFs to minimal (<15 %) with the use of 50 % CNFs. NorCMC and CNF networks interacted synergistically to create hydrogels with compression modulus values spanning 1 to 150 kPa - the values of most biological tissues. T:N and total polymer weight percent could be varied to create hydrogels with different CNF content, but the same compression modulus, targeting 10 and 100 kPa hydrogels and providing a system that can independently vary fibrillar content and bulk modulus. Analysis of the effective crosslinks, thiol-ene network mesh size, and burst release of the polymer indicated synergistic interactions of the NorCMC thiol-ene and CNFs networks. These interactions enhanced modulus and degradation control of the network under physiological conditions.

3D/4D printing of cellulose nanocrystals-based biomaterials: Additives for sustainable applications

Cellulose nanocrystals (CNCs) have gained significant attraction from both industrial and academic sectors, thanks to their biodegradability, non-toxicity, and renewability with remarkable mechanical characteristics. Desirable mechanical characteristics of CNCs include high stiffness, high strength, excellent flexibility, and large surface-to-volume ratio. Additionally, the mechanical properties of CNCs can be tailored through chemical modifications for high-end applications including tissue engineering, actuating, and biomedical. Modern manufacturing methods including 3D/4D printing are highly advantageous for developing sophisticated and intricate geometries. This review highlights the major developments of additive manufactured CNCs, which promote sustainable solutions across a wide range of applications. Additionally, this contribution also presents current challenges and future research directions of CNC-based composites developed through 3D/4D printing techniques for myriad engineering sectors including tissue engineering, wound healing, wearable electronics, robotics, and anti-counterfeiting applications. Overall, this review will greatly help research scientists from chemistry, materials, biomedicine, and other disciplines to comprehend the underlying principles, mechanical properties, and applications of additively manufactured CNC-based structures.

Melatonin-mediated IGF-1/GLP-1 activation in experimental OCD rats: Evidence from CSF, blood plasma, brain and in-silico investigations

Obsessive-compulsive disorder (OCD) is a neuropsychiatric condition characterized by intrusive, repetitive thoughts and behaviors. Our study uses a validated 8-OH-DPAT-induced experimental model of OCD in rodents. We focus on the modulatory effects of Insulin-like growth factor-1 (IGF-1) and glucagon-like peptide-1 (GLP-1), which are linked to neurodevelopment and survival. Current research investigates melatonin, a molecule with neuroprotective properties and multiple functions. Melatonin has beneficial effects on various illnesses, including Alzheimer's, Parkinson's, and depression, indicating its potential efficacy in treating OCD. In the present study, we employed two doses of melatonin, 5 mg/kg and 10 mg/kg, demonstrating a dose-dependent effect on 8-OH-DPAT-induced rat changes. In addition, the melatonin antagonist luzindole 5 mg/kg was utilized to compare and validate the efficacy of melatonin. In-silico studies alsocontribute to understanding the activation of IGF-1/GLP-1 pathways by melatonin. Current research indicates restoring neurochemical measurements on various biological samples (brain homogenates, CSF, and blood plasma) and morphological and histological analyses. In addition, the current research seeks to increase understanding of OCD and investigate potential new treatment strategies. Therefore, it is evident from the aforementioned research that the protective effect of melatonin can serve as a strong basis for developing a new OCD treatment by upregulating IGF-1 and GLP-1 levels. The primary focus of current study revolves around the examination of melatonin as an activator of IGF-1/GLP-1, with the aim of potentially mitigating behavioral, neurochemical, and histopathological abnormalities in an experimental model of obsessive-compulsive disorder caused by 8-OH-DPAT in adult Wistar rats.

Adhesive and biodegradable polymer mixture composed of high -biosafety pharmaceutical excipients as non-setting periodontal dressing

Periodontal dressing is a surgical dressing applied to oral wounds after periodontal surgery. Currently, all commercially available setting periodontal dressings are stiff, uncomfortable, with poor aesthetics, and need to be removed at the patient's follow-up visit, which may cause secondary damage. A periodontal dressing with soft texture, biodegradable properties, and that could balance both comfort and aesthetics is urgently desired. Hence, non-setting and degradable dressings were developed using sodium carboxymethyl cellulose, Eudragit S 100 and povidone K30, which were compared with the commercial degradable dressing Reso-pac®. The mucosal adhesion of the dressings was evaluated by lap shear tests, which indicated adequate adhesion. The in vitro swelling rates of the dressings were approximately half that of Reso-pac®, which led to less saliva adsorption and better dimensional stability. The dressings also exhibited satisfactory biocompatibility according to the results of CCK-8, Live/Dead staining, hemolysis, and subcutaneous implantation assays. Moreover, the dressing promoted the healing of full-thickness mucosal wounds in the palatal gingivae of SD rats and contributed to better therapeutic effect than Reso-pac®. Considering the multiple advantages and the pure pharmaceutical excipient formula, we anticipate that this dressing could be a promising product and may enter clinical practice in the near future.

The Role of Calcium Hydroxylapatite (Radiesse) as a Regenerative Aesthetic Treatment: A Narrative Review

For decades, a wide variety of natural and synthetic materials have been used to augment human tissue to improve aesthetic outcomes. Dermal fillers are some of the most widely used aesthetic treatments throughout the body. Initially, the primary function of dermal fillers was to restore depleted volume. As biomaterial research has advanced, however, a variety of biostimulatory fillers have become staples in aesthetic medicine. Such fillers often contain a carrying vehicle and a biostimulatory material that induces de novo synthesis of major structural components of the extracellular matrix. One such filler, Radiesse (Merz Aesthetics, Raleigh, NC), is composed of calcium hydroxylapatite microspheres suspended in a carboxymethylcellulose gel. In addition to immediate volumization, Radiesse treatment results in increases of collagen, elastin, vasculature, proteoglycans, and fibroblast populations via a cell-biomaterial-mediated interaction. When injected, Radiesse acts as a cell scaffold and clinically manifests as immediate restoration of depleted volume, improvements in skin quality and appearance, and regeneration of endogenous extracellular matrices. This narrative review contextualizes Radiesse as a regenerative aesthetic treatment, summarizes its unique use cases, reviews its rheological, material, and regenerative properties, and hypothesizes future combination treatments in the age of regenerative aesthetics.

LEVEL OF EVIDENCE: 5

Tissue Regeneration with Gelatine/Polysaccharide Derived Hydrogel Scaffolds: From Formulation to In Vivo Efficacy

Combinations of different biomaterials with certain formulations may lead to improved properties and have significant potential for use in tissue regeneration applications. However, previously reported studies comparing biomaterials often suffered from inconsistent processing methods or inadequate comprehensive application research, hindering a comprehension of their efficacy in tissue engineering. This report explores the significance of screening the combination of gelatine with polysaccharide materials, specifically hyaluronic acid (HA) and carboxymethyl cellulose (CMC), using the same crosslinking method used for tissue regeneration. Hydrogel scaffolds (Gel/HA and Gel/CMC) at various concentrations were developed and characterized to assess their physiochemical properties. The results demonstrated that the hydrogels exhibited desirable mechanical properties, appropriate swelling behaviour, suitable porosity, and excellent cytocompatibility. In particular, the Gel1HA1 and Gel1CMC1 hydrogels showed remarkable cellular proliferation and aggregation. Further, we performed animal studies and explored the tissue regeneration effects of the Gel1HA1 and Gel1CMC1 hydrogels. Both hydrogels exhibited an accelerated wound closure rate and promoted vessel formation in a rodent full-thickness skin excisional model. Additionally, the subcutaneous implantation model demonstrated the induction of angiogenesis and collagen deposition within the implanted hydrogel samples. Overall, the hydrogels developed in this study demonstrated promising potential for use in the regeneration of soft tissue defects and this study emphasizes the significance of screening biomaterial combinations and formulations for tissue regeneration applications.

4D printed multipurpose smart implants for breast cancer management

Breast-conserving surgery (BCS) is the primary strategy for treating early-stage breast cancer; however, the incidence of local recurrence and breast tissue loss negatively impacts patients and survivors. Furthermore, radiotherapy and/or systemic therapies are frequently advised to avoid recidivism and increase the patient's chance of survival, resulting in longer duration of treatments, and unpleasant systemic side effects. Given the poor prognosis and the heterogeneity between individuals and tumors, a patient-centered approach is fundamental. Herein we developed a multipurpose 4D printed implant made of a blend of carboxymethyl cellulose sodium salt (CMC) and cellulose nanocrystals (CNC), loaded with doxorubicin (DOX). To predict printability performance, full rheological characterization was carried out. The smart device was programmed to change size, under swelling, to better fit in the tissue cavity, resulting in a great potential for personalization, thus improving the aesthetic outcomes. The influence of the formulation and printing parameters on the morpho transformation was investigated through the swelling test, confirming the possibility to program the 4D shape. The manufactured implants were characterized by a variety of methods, including in vitro release studies. Lastly, the anticancer activity was conducted in vitro, on MDA-MB-231 cells. Implants promoted an anticancer effect of -58% viability after 72h incubation, even when tested 4 weeks after the printing process. Overall, the morpho transformation and the in vitro studies have shown that the implant could represent a potential strategy for breast cancer following resection, to fill the void in the breast resulting from the surgery and provide an anticancer effect to avoid recurrence.

Carboxymethyl cellulose-agarose-gelatin: A thermoresponsive triad bioink composition to fabricate volumetric soft tissue constructs

Polysaccharide based hydrogels have been predominantly utilized as ink materials for 3D bioprinting due to biocompatibility and cell responsive features. However, most hydrogels require extensive crosslinking due to poor mechanical properties leading to limited printability. To improve printability without using cytotoxic crosslinkers, thermoresponsive bioinks could be developed. Agarose is a thermoresponsive polysaccharide with upper critical solution temperature (UCST) for sol-gel transition at 35-37 °C. Therefore, we hypothesized that a triad of carboxymethyl cellulose(C)-agarose(A)-gelatin(G) could be a suitable thermoresponsive ink for printing since they undergo instantaneous gelation without any addition of crosslinkers after bioprinting. The blend of agarose-carboxymethyl cellulose was mixed with 1% w/v, 3% w/v and 5% w/v gelatin to optimize the triad ratio for hydrogel formation. It was observed that a blend (C2-A0.5-G1 and C2-A1-G1) containing 2% w/v carboxymethyl cellulose, 0.5% or 1% w/v agarose and 1% w/v gelatin formed better hydrogels with higher stability for up to 21 days in DPBS at 37 °C. Further, C2-A0.5-G1 and C2-A1-G1hydrogels showed higher storage modulus 762 ± 182 Pa & 2452 ± 430 Pa, higher porosity of 96.98 ± 2% & 98.2 ± 0.8% and swellability of 1518 ± 68% & 1587 ± 25% respectively. To evaluate the in vitro potential of these bioink formulations, indirect and direct cytotoxicity were determined using NCTC clone 929 (mouse fibroblast cells) and HADF (primary human adult dermal fibroblast) cells as per the ISO 10993-5 standards. Importantly, the printability of these bioinks was confirmed using extrusion bioprinting by successfully printing different complex 3D patterns.