Preparation, characterization, and antibacterial property of carboxymethyl cellulose derivatives bearing tetrabutylammonium salt

Sodium Alginate- and Cationic Cellulose-Functionalized Polycaprolactone Nanofibers for In Vitro and Antibacterial Applications

The use of polyelectrolytes is emerging as a fascinating strategy for the functionalization of biomedical membranes, due to their ability to enhance biological responses using the interaction effect of charged groups on multiple interface properties. Herein, two different polyelectrolytes were used to improve the antibacterial properties of polycaprolactone (PCL) nanofibers fabricated via electrospinning. First, a new cationic cellulose derivative, cellulose-bearing imidazolium tosylate (CIMD), was prepared via the nucleophilic substitution of the tosyl group using 1-methylimidazole, as confirmed by NMR analyses, and loaded into the PCL nanofibers. Secondly, sodium alginate (SA) was used to uniformly coat the fibers' surface via self-assembly, as remarked through SEM-EDX analyses. Polyelectrolyte interactions between the CIMD and the SA, initially detected using a FTIR analysis, were confirmed via Z potential measurements: the formation of a CMID/SA complex promoted a substantial charge neutralization of the fibers' surfaces with effects on the physical properties of the membrane in terms of water adsorption and in vitro degradation. Moreover, the presence of SA contributed to the in vitro response of human mesenchymal stem cells (hMSCs), as confirmed by a significant increase in the cells' viability after 7 days in the case of the PCL/CMID/SA complex with respect to the PCL and PCL/CMID membranes. Contrariwise, SA did not nullify the antibacterial effect of CMID, as confirmed by the comparable resistance exhibited by S. mutans, S. aureus, and E. coli to the PCL/CIMD and PCL/CIMD/SA membranes. All the reported results corroborate the idea that the CIMD/SA functionalization of PCL nanofibers has a great potential for the fabrication of efficient antimicrobial membranes for wound healing.

Superhydrophilic quaternized calcium alginate based aerogel membrane for oil-water separation and removal of bacteria and dyes

In recent years, frequent oil spills and increasing industrial wastewater discharge have caused serious water pollution problems. In addition, there are often microbial and dye pollutants in oil-containing wastewater. The development of materials that can simultaneously treat these three pollutants is very important for the safe treatment and recovery of wastewater. In this work, a modified calcium alginate-based aerogel membrane (CTW) was prepared through sol spraying, Ca²⁺ crosslinking and freeze drying by using tetrabutylammonium hydroxide (TBA) quaternary ammonium salt modified sodium alginate (SA) as raw material and waterborne polyurethane (WPU) as adhesive. The results show that CTW membrane has super hydrophilic and underwater super-oleophobic properties, and can realize the separation oil-water emulsions under gravity, with the separation efficiency of >99 %. CTW membrane can also remove bacteria and dye such as Congo red from water by filtration, with removal rates of 100 % and 99 % respectively. The filtration results of mixed wastewater show that CTW membrane can realize one-step separation of oil, bacteria and dye in wastewater, and can also be recycled, having potential application prospect.

Sequestration and toxicological assessment of emerging contaminants with polypyrrole modified carboxymethyl cellulose (CMC/PPY): Case of ibuprofen pharmaceutical drug

Ibuprofen (IBU) is a non-steroidal anti-inflammatory drug released into water bodies causing toxic biological effects on living organisms. The current study aims to eliminate IBU from aqueous solutions by a novel carboxymethylcellulose/polypyrrole (CMC/PPY) composite with high removal efficiency. Pyrrole was polymerized to polypyrrole whose average size was about 20 nm on the CMC surface. The maximum removal percentage of IBU by CMC/PPY composite was optimized at initial concentration 10 mg/L, dosage 0.02 g, and pH 7 with adsorption capacity of 72.30 (mg/g) and removal of 83.17 %. IBU adsorption onto CMC/PPY theoretically fits into the Langmuir isotherm and Elovich-kinetic models. Fish and Phytotoxicity assessment were performed with zebrafish and seeds of Vigna mungo (VM) and Vigna radiata (VR). The toxicity study reveals that before adsorption, IBU shows high toxicity towards the zebrafish mortality (33 %), growth inhibition (58.52 % for VM, 60.84 % for VR), and germination (86.66 % for VM and 90 % for VR). As CMC/PPY adsorbs IBU, toxicity drastically decreases. Before adsorption, LC₅₀ was 233.02 mg/L. After adsorption, the LC₅₀ increases to 2325.07 mg/L as IBU molecules get adsorbed by CMC/PPY. These findings show the feasibility of preparing CMC/PPY composite to effectively remove pharmaceutical pollutant IBU from aqueous solutions with their toxicological assessment.

Proton-Conducting Biopolymer Electrolytes Based on Carboxymethyl Cellulose Doped with Ammonium Formate

In this work, CMC-AFT biopolymer electrolytes system was developed using Carboxymethyl cellulose (CMC) doped with varied amount (10-50 wt.%) of ammonium formate (AFT) in order to study the effect of AFT on the biopolymer-salt system. The chemical structure of the biopolymer was studied using Fourier-Transform infrared (FTIR) and X-ray diffraction (XRD). The interaction between the COO^- of CMC and the weakly-bound H⁺ of NH₄⁺ AFT occurred at 1573 cm^-1 as seen in FTIR analysis and the amorphous phase was found to increase with the addition of AFT as seen from XRD pattern. Both FTIR and XRD testing indicates that the AFT had disrupted the CMC crystalline structure. The ionic conductivity of the CMC-AFT biopolymer electrolytes increases and achieved the highest value of 1.47 × 10^-4 S·cm^-1 with the addition of AFT. The impedance measurement showed that the capacitive and resistive behavior inside the biopolymer diminished when 50 wt.% of AFT was added. Dielectric analysis confirmed the increased number of charge carriers is due to the increase in AFT composition. Further dielectric analysis showed the occurrence of conductivity relaxation peak thus affirmed the charge carriers' ability to travel further to a longer distances when AFT composition increases from 10 to 50 wt.%. The dielectric properties confirmed the non-Debye behavior of the CMC-AFT biopolymer electrolytes.

6-deoxy-aminocellulose derivatives embedded soft gelatin methacryloyl (GelMA) hydrogels for improved wound healing applications: In vitro and in vivo studies

Hydrogels were prepared by mixing protein and carbohydrate-based biopolymers to increase the mechanical properties and efficient cell adhesion and proliferation for wound healing applications. Microcrystalline cellulose (MCC) and its 6-deoxy-aminocellulose derivatives (6-deoxy-6-hydrazide Cellulose (Cell-Hyd), 6-deoxy-6-diethylamide Cellulose (Cell-DEA), and 6-deoxy-6-diethyltriamide Cellulose (Cell-DETA)) were embedded in methacrylated gelatin (GelMA). GelMA and 6-deoxy-aminocellulose derivatives were synthesized and characterized by spectroscopic techniques. MCC and cellulose derivatives embedded GelMA gels were characterized by FTIR, SEM and Tensile mechanical testing. SEM images revealed that, porosity of the amine MCC incorporated GelMA was decreased compared to GelMA and MCC incorporated GelMA. Tensile strain of GelMA 61.30% at break was increased to 64.3% in case of GelMA/Cell-HYD. In vitro cytocompatibility and cell proliferation using NIH-3T3 cell lines showed cell density trend on scaffold as GelMA/Cell-DETA>GelMA/Cell-Hyd > GelMA. Scratch assay for wound healing revealed that GelMA/Cell-DETA showed complete wound closure, while GelMA/Cell-Hyd and GelMA exhibited 85.7%, and 66.1% wound healing, respectively in 8 h. In vivo tests on rats revealed that GelMA/Cell-DETA exhibited 98% wound closure on day 9, whereas GelMA/Cell-Hyd exhibited 97.7% and GelMA 66.1% wound healing on day 14. Our findings revealed that GelMA embedded amine MCC derivatives hydrogels can be applied for achieving accelerated wound healing.