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Indirect cell contact co-culture system is increasingly becoming more attractable owing to their advantages of easy cell separation and desirable outcomes for cell–cell interactions. However, how to precisely control the spatial position of cells within multicellular co-cultures is still experimentally challenging due to the incapability of the conventional methods in vitro . In the present study, a tunable collagen/alginate-chitosan (Col/Alg-Chi) membrane was established, which was capable of controlling intercellular distance between the neighboring cells at a level of micrometer resolution. It was showed that intercellular distance between the hepatocytes and the fibroblasts exerted significant influence on hepatic function in vitro . In particular, maintenance of the functionality of primary hepatocytes requires direct contact between the hepatocytes and their supportive stromal cells, and their effective contact distance is within 30 μm. This technical platform would potentially enable investigations of dynamic cell–cell interaction in a multitude of applications including organogenesis, development or even neoplastic transformation. [ABSTRACT FROM AUTHOR]

Small-interfering RNA (siRNA)-mediated gene silencing with the aid of chitosan (CS)-based carriers has shown efficient and reliable outcome in vitro , but the gene silencing efficiency in vivo is still limited. It is of great importance to balance the protection and release of siRNA from nanoparticles (NPs) so as to achieve high efficiency. However, siRNA release profile from CS/siRNA NPs has been rarely concerned. Here, Förster resonance energy transfer technique was adopted for in vitro investigation of siRNA release from CS NPs in lysozyme-contained buffer. The results clearly showed that siRNA molecules experienced a fast and short release phase under lysozyme competition to both CS and siRNA, and then a slow and long release under lysozyme degradation on CS. Moreover, lysozyme competition played more important role than enzymolysis on trigging siRNA release. This preliminary study of siRNA release is the first step to get insight of in vivo siRNA release mechanism from CS/siRNA NPs, which will be helpful to adjust the design of CS/siRNA NPs for balancing the protection and release of siRNA molecules. [ABSTRACT FROM AUTHOR]

Marine polysaccharide-based hydrogels have drawn much attention for diversified biomedical applications owing to their excellent (bio)physicochemical properties. In the present work, a series of marine polysaccharide-based hydrogels composed of chitosan, alginate, or fucoidan are prepared via a facile chemical cross-linking approach in an alkali/urea aqueous system. The prepared hydrogels possess tunable microporous architecture, swelling, and biodegradable properties by changing the components and proportions of marine polysaccharides. Importantly, the developed hydrogels are mechanically robust and the maximum compressive stress is up to 28.37 ± 4.63 kPa. Furthermore, the composite hydrogels exhibit excellent cytocompatibility, blood compatibility, and histocompatibility. When implanted subcutaneously in rats, the hydrogels containing fucoidan inhibit the inflammatory response of surrounding tissue. Thus, the designed composite hydrogels are promising bio-scaffolds in biomedical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Conventional wound-dressing materials with structural and functional deficiencies are not effective in promoting wound healing. The development of multifunctional wound dressings is emerging as a promising strategy to accelerate blood coagulation, inhibit bacterial infection, and trigger full-thickness wound into a regenerative process. Herein, multifunctional composite sponges were developed by incorporation of traditional Chinese medicine Kangfuxin (KFX) into alginate (AG)/carboxymethyl chitosan (CMC) via green crosslinking, electrostatic interaction, and freeze-drying methods. It is demonstrated that the AG/CMC/KFX (ACK) sponges exhibit a highly interconnected and porous structure, suitable water vapor transmittance, excellent elastic properties, antibacterial behavior, cytocompatibility, and rapid hemostasis. Further, in a rat full-thickness wounds model, the ACK sponge containing 10% KFX (ACK-10) significantly facilitates wound closure compared to the AC group and ACK sponge containing 5% and 15% KFX. Thus, the multifunctional ACK-10 composite sponge has great promise for the application of full-thickness wound healing. Unlabelled Image • Multifunctional alginate/carboxymethyl chitosan/kangfuxin sponges (ACK) were successfully fabricated. • ACK possessed a highly porous structure and excellent elastic properties. • ACK accelerated hemostasis and inhibited bacterial infection • ACK triggered the full-thickness wound into a regenerative process. [ABSTRACT FROM AUTHOR]

Abstract In the present work, five polysaccharides were selected as co-encapsulant of skim milk based matrix and used for the microencapsulation of Lactobacillus paracasei Lpc-37 by spray drying. The morphological characterization, physical properties, encapsulation efficiency, gastrointestinal simulation, and storage stability of microencapsules were examined to evaluate the protective capacity against the adverse conditions of the different wall matrices. Addition of polysaccharides was associated with the enhancement of physical performance of microencapsulated powders, such as the flowability and water activity. Encapsulation matrices containing gum Arabic showed the greatest encapsulation efficiency of 97.1% (maximum survival 7.78 log CFU/g). L. paracasei Lpc-37 encapsulated with the matrices incorporating sodium alginate or sodium carboxymethylcellulose exhibited higher survival (>6.5 log CFU/g) after exposed to simulated gastrointestinal condition and lower viability loss (<0.3 log CFU/g) after 8 weeks of refrigerated storage. The application of polysaccharides, however, showed the tendency of higher hygroscopicity and lower stability of the powders in high temperature and humid environment. Highlights • The applied polysaccharides improved the flowability of microencapsulated powder. • Gum Arabic maintained L. paracasei viable during spray-drying process. • Sodium alginate and sodium carboxymethylcellulose enhanced L. paracasei viability during simulated digestion. [ABSTRACT FROM AUTHOR]

Developing bio-multifunctional wound dressings with excellent hemostasis, antibacterial, anti-inflammatory, enhanced angiogenesis and hair follicle regeneration for promoting full-thickness wound healing is highly valuable in clinical application. Herein, bio-multifunctional composite sponges were prepared by coupling alginate and chitosan with fucoidan through electrostatic interaction, Ca2+ crosslinking, and lyophilization processes. The prepared alginate/chitosan/fucoidan (ACF) sponges display excellent elastic properties, preserving their shape even after bending and compressive strain without failure. The ACF sponge containing 10% fucoidan (ACF-1) shows better hemostatic and antibacterial performances, and significantly promotes wound closure in a rat full-thickness wounds model compared to the alginate/chitosan group and ACF sponge containing 30% fucoidan. Furthermore, the ACF-1 sponge greatly facilitates the epithelialization and the formation of collagen in the dermis, promotes the hair follicle regeneration, enhances vascularization by upregulating the protein expression of CD31, and reduces inflammation by downregulating the protein expression of TNF-α. This work suggests that ACF sponges with a certain amount of fucoidan display great potential for the treatment of full-thickness skin repair. Unlabelled Image • Bio-multifunctional ACF sponges were successfully prepared through a facile, efficient, green cross-linked, and freeze-drying processes. • The ACF sponges possessed excellent hemostatic and antibacterial performances as well as greatly promoted full-thickness wound healing. • The ACF sponges reduced inflammation, facilitated the epithelialization, as well as enhanced angiogenesis and hair follicle regeneration. [ABSTRACT FROM AUTHOR]