Intestinal delivery of probiotics to modulate microbiome compositions has potential effects on the treatment of plenty of human diseases. However, the gastric acid in the stomach can greatly reduce the number of viable probiotics that reach the intestine. Here, sodium alginate/cellulose nanofiber gel macrospheres (ACMs) were fabricated by extruding a mixture of sodium alginate (SA) and TEMPO-oxidized cellulose nanofiber (CNF) into CaCl2 solutions for cross-linking. These gel macrospheres were evaluated as capsules for the encapsulation of probiotics. The structure of ACMs was studied by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD). The thermal properties, morphological properties, swelling properties, and cell viability of ACMs were also investigated. Moreover, the proliferation of probiotics in ACMs and in vitro release of probiotics from ACMs were evaluated. The results show that ACMs are stabilized in simulated gastric fluid, ensuring better protection of encapsulated probiotics in acidic environment. On the contrary, they will swell in simulated intestinal fluid, contributing to the release of encapsulated probiotics. The pH-responsive property of ACMs make them available to protect probiotics in simulated gastric fluids as well as release probiotics in simulated intestinal fluids, indicating potential application for intestinal-targeted delivery of probiotics.

Cellulose-based composite macrogels made by cellulose fiber/cellulose nanofiber (CCNM) were used as an intestine delivery vehicle for probiotics. Cellulose nanofiber (CNF) was prepared by a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation system, and the carboxyl groups in CNF acted as pore size and pH responsibility regulators in CCNMs to regulate the probiotics loading and controlled release property. The macrogel presented a porosity of 92.68% with a CNF content of 90%, and the corresponding released viable Lactobacillus plantarum (L. plantarum) was up to 2.68 × 10 cfu/mL. The porous structure and high porosity benefited L. plantarum cells to infiltrate into the core of macrogels. In addition, the macrogels made with high contents of CNF showed sustainable release of L. plantarum cells and delivered enough viable cells to the desired region of intestine tracts. The porous cellulose macrogels prepared by a green and environmental friendly method show potential in the application of fabricating targeted delivery vehicles of bioactive agents.

Easy and rapid continuous large-scale industrial production of transparent visualized cutaneous wound healing dressing from natural polymers is very worth studying in medical natural polymer materials and multifunction gauze dressing design fields. In this work, superclear, porous cellulose membranes (CMs) with chitosan-coated nanofibers were fabricated using a simple, one-step electrostatic spinning technology and evaluated as potential wound dressings. First, the pure CMs were dissolved by a simple physical method, and then, the membranes were regenerated in an acidic coagulation bath by the casting method. The chitosan solution was polarized into nanofibers and formed a continuous fiber mat on CMs because of the charge repulsion between molecules. The prepared chitosan-coated CMs (CM-CS) were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, tensile tests, and so forth. The results indicated that CM-CS showed high wettability, hydrophilicity, and gas permeability, in addition to excellent light transmittance and mechanical compliance. Cell cytotoxicity and morphology assay and antibacterial activity against Escherichia coli and Staphylococcus aureus were also studied. They exhibited good biocompatibility and antibacterial activity of CM-CS. Moreover, evaluation of an in vivo wound healing model in mice revealed that CM-CS had a good effect in promoting wound healing. This work provided an easy and rapid continuous large-scale industrial design strategy for natural bioresource-based wound dressing materials, which could act as potential wound dressings for clinical use.

Cellulose anionic hydrogels were successfully prepared by dissolving TEMPO-oxidized cellulose nanofibers in NaOH/urea aqueous solution and being cross-linked with epichlorohydrin. The hydrogels exhibited microporous structure and high hydrophilicity, which contribute to the excellent water absorption property. The growth indexes, including the germination rate, root length, shoot length, fresh weight, and dry weight of the seedlings, were investigated. The results showed that cellulose anionic hydrogels with suitable carboxylate contents as plant growth regulators could be beneficial for seed germination and growth. Moreover, they presented preferable antifungal activity during the breeding and growth of the sesame seed breeding. Thus, the cellulose anionic hydrogels with suitable carboxylate contents could be applied as soilless culture mediums for plant growth. This research provided a simple and effective method for the fabrication of cellulose anionic hydrogel and evaluated its application in agriculture.