Mucic acid is a hexaric acid that can be biosynthesized by oxidation of D-galacturonic acid, which is the main constituent of pectin. The structure and properties of mucic acid are similar to that of glucaric acid, and can be widely applied in the preparation of important platform compounds, polymers and macromolecular materials. Pectin is a cheap and abundant renewable biomass resource, thus developing a process enabling production of mucic acid from pectin would be of important economic value and environmental significance. This review summarized the structure and hydrolysis of pectin, the catabolism and regulation of D-galacturonic acid in microorganisms, and the strategy for mucic acid production based on engineering of corresponding pathways. The future application of mucic acid are prospected, and future directions for the preparation of mucic acid by biological method are also proposed.
Hexuronic Acids/metabolism* ; Pectins/metabolism* ; Sugar Acids/metabolism*

In the present study, a gastric retention floating system for Brucea javanica oil, composed of alginate and carrageenan, was prepared using ionotropic gelation. Parameters for floatability, drug load, encapsulation efficiency, bead morphology, in vitro release, and in vivo gastric retention were evaluated. The optimized formulation via Box-Behnken design consisted of 1.7% alginate (W/V), 1.02% carrageenan (W/V), 1.4% CaCO (W/V), and a gelling bath of pH 0.8. The alginate-carrageenan-Brucea javanica oil beads had a porous structure and exhibited up to 24 h of in vitro floatability with a load capacity of 45%-55% and an encapsulation efficiency of 70%-80%. A 6-h sustained release was observed in vitro. The beads had a prolonged gastric retention (> 60% at 6 h) in fasted rats, compared to non-floating beads (15% at 6 h), as measured by gamma scintigraphy with single-photon emission tomography/computed tomography (SPET/CT). In conclusion, the alginate-carrageenan-Brucea javanica oil system showed enhanced oil encapsulation efficiency, excellent floating and gastric retention abilities, and a favorable release behavior.
Alginates ; chemistry ; Animals ; Biological Availability ; Brucea ; chemistry ; Carrageenan ; chemistry ; Delayed-Action Preparations ; administration & dosage ; chemistry ; pharmacokinetics ; Drug Carriers ; chemistry ; Drug Delivery Systems ; methods ; Drug Evaluation, Preclinical ; Gastric Mucosa ; metabolism ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Microspheres ; Plant Oils ; administration & dosage ; chemistry ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley

To observe the effect of uniform and shift rotation culture on the formation and activity of the alginate-chitosan (AC) microencapsulated HepLL immortalized human hepatocytes and HepG2 cells aggregates.AC microcapsulated HepG2 and HepLL cells were randomly divided into two groups. Each group was divided into 3 subgroups according to uniform and shift rotation culture.The size and number of aggregates were observed and measured under laser confocal microscopy and inverted microscope dynamically. The amount of albumin synthesis was detected by ELISA, the clearance of ammonia was detected by colorimetry, and diazepam conversion function was detected by high performance liquid chromatography (HPLC).On day 6, 8, 10, 12, 14 and 16, the number and size of the aggregates, albumin synthesis, diazepam clearance and ammonium clearance increased significantly in shift rotation culture group than in uniform group (all<0.01). The albumin synthesis, diazepam clearance, and ammonium clearance in the microencapsulated HepLL groups were significantly higher than those of HepG2 cells at any time (all<0.01).Shift rotation culture can significantly promote the formation and increase the activity of AC microencapsulated HepLL and HepG2 aggregates, and HepLL cells may be more suitable for bioartificial liver than HepG2.
Albumins ; biosynthesis ; metabolism ; Alginates ; Ammonia ; metabolism ; Animals ; Cell Aggregation ; physiology ; Cell Culture Techniques ; methods ; Cell Line, Transformed ; physiology ; Chitosan ; Diazepam ; metabolism ; Glucuronic Acid ; Hep G2 Cells ; cytology ; physiology ; Hepatocytes ; cytology ; physiology ; Hexuronic Acids ; Humans ; Liver, Artificial ; Rotation

OBJECTIVETo fabricate an innovative scaffold for lung cancer cell culture and establish a three-dimensional lung cancer model in vitro, and to reveal the differences in biological functions of lung cancer cells under the two-dimensional and three-dimensional culture conditions.

METHODSWe chose agarose and alginate as the scaffold materials, and 3D printing technique was applied to construct cell culture scaffold. 95D cells were co-cultured with this scaffold. The differences of cell morphology, proliferation ability, protein expression, etc. in the cells cultured under 2D and 3D cultural conditions were evaluated by light microscopy using HE staining, MTT assay, scanning electron microscopy, and Western blot analysis.

RESULTSCells cultured in 2D wells displayed a spindle and polygonal morphology, whereas those grown in the 3D culture aggregated into spheroids, which invaded, migrated and disseminated into the surrounding scaffold. MTT assay showed that the proliferation rates of the 3D-cultured cells for 2-6 days were significantly lower than, but those cultured for 8-9 days were significantly higher than that of the 2D-cultured cells, indicating that proliferative activity of the cells grown in 2D cultures for 8-9 days was inhibited. In contrast, cells grown on 3D scaffolds still maintained a higher proliferation. The Western blot assay showed that the expression of Cdc42, p53, mTOR were significantly down-regulated in 3D scaffold-cultured group (0.529±0.103, 0.820±0.038 vs. 1.967±0.066), compared with that of the 2D-cultured group (3.063±0.139, 1.738±0.122 vs. 2.472±0.151) (P<0.05 for all), while the expression of MMP-2 was up-regulated in the 3D-cultured cells (1.110±0.029), significantly higher than that of the 2D-cultured cells (0.017±0.001) (P<0.05).

CONCLUSIONSThe cell morphology, proliferation and associated protein expression of lung cancer cells in 3D-culture systems are distinctively different as compared to those of the 2D-cultural cells. 3D-bioprinted agarose-alginate scaffold can better mimic the growth microenvironment of lung cancer in vivo and may provide a promising model for lung cancer research in vitro.

Alginates ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; physiopathology ; Cell Culture Techniques ; Cell Movement ; Cell Proliferation ; Cells, Cultured ; Coculture Techniques ; Glucuronic Acid ; Hexuronic Acids ; Humans ; Lung Neoplasms ; metabolism ; pathology ; physiopathology ; Neoplasm Invasiveness ; Neoplasm Proteins ; metabolism ; Printing, Three-Dimensional ; Sepharose ; Spheroids, Cellular ; pathology ; Time Factors ; Tissue Scaffolds ; Tumor Microenvironment

OBJECTIVEAlthough chondroprotective activities have been documented for polysaccharides, the potential target of different polysaccharide may differ. The study was aimed to explore the effect of glucan HBP-A in chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs in vivo, especially on the expression of type II collagen.

METHODSChondrocytes isolated from rabbit articular cartilage were cultured and verified by immunocytochemical staining of type II collagen. Chondrocyte viability was assessed after being treated with HBP-A in different concentrations. Morphological status of chondrocytes-alginate hydrogel constructs in vitro was observed by scanning electron microscope (SEM). The constructs were treated with HBP-A and then injected to nude mice subcutaneously. Six weeks after transplantation, the specimens were observed through transmission electron microscopy (TEM). The mRNA expressions of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTs-5), aggrecan and type II collagen in both monolayer culture and constructs were determined by real time polymerase chain reaction (PCR). The expression of type II collagen and matrix metalloproteinases-3 (MMP-3) in chondrocyte monolayer culture was also tested through Western blot and enzyme linked immunosorbent assay (ELISA), respectively.

RESULTSMMP-3 secretion and ADAMTs-5 mRNA expression in vitro were inhibited by HBP-A at 0.3 mg/mL concentration. In morphological study, there were significant appearance of collagen in those constructs treated by HBP-A. Accordingly, in both chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs, the expression of type II collagen was increased significantly in HBP-A group when compared with control group (P<0.001).

CONCLUSIONSThe study documented that the potential pharmacological target of glucan HBP-A in chondrocytes monolayer culture and tissue engineered cartilage in vivo may be concerned with the inhibition of catabolic enzymes MMP-3, ADAMTs-5, and increasing of type II collagen expression.

ADAM Proteins ; genetics ; metabolism ; Aggrecans ; genetics ; metabolism ; Alginates ; pharmacology ; Animals ; Cartilage, Articular ; drug effects ; physiology ; Cell Proliferation ; drug effects ; Cell Shape ; drug effects ; Cell Survival ; drug effects ; Chondrocytes ; cytology ; drug effects ; metabolism ; ultrastructure ; Collagen Type II ; genetics ; metabolism ; Female ; Glucans ; pharmacology ; Glucuronic Acid ; pharmacology ; Hexuronic Acids ; pharmacology ; Hydrogel, Polyethylene Glycol Dimethacrylate ; pharmacology ; Immunohistochemistry ; Matrix Metalloproteinase 3 ; metabolism ; Mice, Nude ; RNA, Messenger ; genetics ; metabolism ; Rabbits ; Tissue Engineering ; methods

The cis-epoxysuccinate hydrolase (CESH) from Rhizobium strain BK-20 is the key enzyme for L(+)-tartaric acid production. To establish a highly efficient and stable production process, we first optimized the enzyme production from Rhizobium strain BK-20, and then developed an immobilized cell-culture process for sustained production of L(+)-tartaric acid. The enzyme activity of free cells reached (3 498.0 +/- 142.6) U/g, and increased by 643% after optimization. The enzyme activity of immobilized cells reached (2 817.2 +/- 226.7) U/g, under the optimal condition with sodium alginate as carrier, cell concentration at 10% (W/V) and gel concentration at 1.5% (W/V). The immobilized cells preserved high enzyme activity and normal structure after 10 repeated batches. The conversion rate of the substrate was more than 98%, indicating its excellent production stability.
Alginates ; chemistry ; Cells, Immobilized ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Hydrolases ; metabolism ; Rhizobium ; enzymology ; metabolism ; Tartrates ; metabolism

BACKGROUNDThe aim of this research was to determine the efficacy of combination therapy using an alginate dressing and mouse epidermal growth factor (mEGF) on proliferation and differentiation of epidermal stem cells (ESCs) in patients with refractory wounds.

METHODSEighteen patients (12 males and 6 females, aged from 18 to 61 years (mean 36.4 years)) with various skin wounds, were treated by dressing changing for one month. The wounds were located in the foot (11), calf (3), thigh (2) and forearm (2). The patients were randomly divided into 3 groups: alginate dressing and mEGF (group A; n = 6), mEGF (group B; n = 6) and control (group C; n = 6). Wound closure indexes were measured at 7, 14, 21 and 28 days. Samples were harvested for pathologic examination, at 7 and 14 days following treatment. Cytokeratin 10 (CK10) and cytokeratin 15 (CK15) positive cells were evaluated using the super-sensitivity (SP) immunohistochemical staining technique.

RESULTSWound healing was promoted in groups A and B. In group A, the wound closure index was increased significantly (P < 0.05), and in one case the maximum cure area reached 102 cm(2). Pathological examination identified a thicker epidermis, active angiogenesis and enhanced granulation in group A compared with groups B and C. Using the SP immunohistochemical staining technique, we showed that ESCs in group A were bigger in size and larger in number than in groups B and C. Overall, there was a significant difference in ESCs proliferation and differentiation between group A and group B (or C).

CONCLUSIONSCombination therapy using an alginate dressing and mEGF shows increased proliferation and differentiation of ESCs in patients with refractory wounds compared with those treated with mEGF alone.

Adolescent ; Adult ; Alginates ; therapeutic use ; Animals ; Bandages ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Epidermal Growth Factor ; therapeutic use ; Epithelial Cells ; cytology ; Female ; Glucuronic Acid ; therapeutic use ; Hexuronic Acids ; therapeutic use ; Humans ; Immunohistochemistry ; Keratin-15 ; metabolism ; Male ; Mice ; Middle Aged ; Stem Cells ; cytology ; drug effects ; Wound Healing ; drug effects ; Young Adult

Transplantation of islet cells into diabetic patients is a promising therapy, provided that the islet cells are able to evade host immune rejection. With improved islet viability, this strategy may effectively reverse diabetes. We applied 2% calcium alginate to generate small and large capsules to encapsulate porcine neonatal pancreatic cell clusters (NPCCs) using an air-driven encapsulator. After encapsulation, the viability was assessed at 1, 4, 7, 14 and 28 days and secretion of functional insulin in response to glucose stimulation were tested at days 14 and 28. Selective permeability of the small alginate capsules was confirmed using various sizes of isothiocyanate-labeled dextran (FITC-dextran). Encapsulation of NPCCs was performed without islet protrusion in the small and large capsules. The viability of NPCCs in all experimental groups was greater than 90% at day 1 and then gradually decreased after day 7. The NPCCs encapsulated in large capsules showed significantly lower viability (79.50 +/- 2.88%) than that of naive NPCCs and NPCCs in small capsule (86.83 +/- 2.32%, 87.67 +/- 2.07%, respectively) at day 7. The viability of naive NPCCs decreased rapidly at day 14 (75.67 +/- 1.75%), whereas the NPCCs encapsulated in small capsules maintained (82.0 +/- 2.19%). After 14 and 28 days NPCCs' function in small capsules (2.67 +/- 0.09 and 2.13 +/- 0.09) was conserved better compared to that of naive NPCCs (2.04 +/- 0.25 and 1.53 +/- 0.32, respectively) and NPCCs in large capsules (2.04 +/- 0.34 and 1.13 +/- 0.10, respectively), as assessed by a stimulation index. The small capsules also demonstrated selective permeability. With this encapsulation technique, small capsules improved the viability and insulin secretion of NPCCs without islet protrusion.
Alginates/chemistry/metabolism ; Animals ; Animals, Newborn ; Capsules/chemistry ; Cell Survival ; Diabetes Mellitus/pathology/*therapy ; Disease Models, Animal ; Glucuronic Acid/chemistry/metabolism ; Graft Rejection/etiology/*prevention & control ; Hexuronic Acids/chemistry/metabolism ; Humans ; Insulin/secretion ; Islets of Langerhans/*metabolism/pathology ; Islets of Langerhans Transplantation/*methods ; Postoperative Complications/etiology/*prevention & control ; *Swine

Marine can be considered as a rather unexplored source of biological material. Production of algal oligosaccharides by using valuable enzymes from marine origin has become an important way to utilize marine resources. As one of algal tool enzymes, the use of alginate lyases has been focused mainly on development and application of alginate oligosaccharides with bioactive function in recent years. In this paper, we reviewed the research of alginate lyases over the past decade in several aspects, including their origin, diversity, substrate specification, mode of action, structure and catalysis mechanism, assay of enzyme activity, enzyme characterization, as well as our own experience on this subject. At the end of the review, the application prospects of alginate lyases are presented.
Alginates ; metabolism ; Glucuronic Acid ; metabolism ; Hexuronic Acids ; metabolism ; Marine Biology ; methods ; Oligosaccharides ; metabolism ; Phaeophyta ; enzymology ; Polysaccharide-Lyases ; classification ; isolation & purification ; metabolism ; Substrate Specificity

This study was intended to investigate the crosslinking characteristics of a new crosslinking agent-oxidized sodium alginate (ADA), which might provide an ideal biological crosslinking reagent for the construction of soft tissue bioprostheses. Glutaraldehyde and genipin, which have been typically used in developing bioprostheses, were used as controls. The porcine aortas were treated by these three crosslinking agents for 15 min to 72 h and the fixation index was determined. Subsequently, the mechanical property and cytocompatibility of fixed tissues were also tested. The results indicated that fixed tissues by ADA were comparable as glutaraldehyde and superior to genipin controls in fixative efficiency. It was also found that tissues fixed by ADA were comparable as genipin and superior to glutaraldehyde controls in cytocompatibility and were similar to natural tissues in mechanical property. The results of in vitro study demonstrated that ADA could be a promising crosslinking reagent for biological tissue fixation.
Alginates ; chemistry ; pharmacology ; Animals ; Aorta ; cytology ; metabolism ; Biocompatible Materials ; metabolism ; Cross-Linking Reagents ; chemistry ; pharmacology ; Extracellular Matrix ; metabolism ; Glucuronic Acid ; chemistry ; pharmacology ; Hexuronic Acids ; chemistry ; pharmacology ; Swine ; Tissue Engineering ; methods ; Tissue Fixation ; Tissue Scaffolds