3D printed carboxymethyl cellulose scaffolds for autologous growth factors delivery in wound healing.

This work aims to use carboxymethyl cellulose (CMC) as main structural and functional component of 3D printed scaffolds for healing of diabetic wounds. Differently from previous inks involving small contents in CMC, herein sterile (steam-heated) concentrated CMC solely dispersions (10-20%w/v) were screened regarding printability and fidelity properties. CMC (15%w/v)-citric acid inks showed excellent self-healing rheological properties and stability during storage. CMC scaffolds loaded with platelet rich plasma (PRP) sustained the release of relevant growth factors. CMC scaffolds both with and without PRP promoted angiogenesis in ovo, stem cell migration in vitro, and wound healing in a diabetic model in vivo. Transparent CMC scaffolds allowed direct monitoring of bilateral full-thickness wounds created in rat dorsum. CMC scaffolds facilitated re-epithelialization, granulation, and angiogenesis in full-thickness skin defects, and the performance was improved when combined with PRP. Overall, CMC is pointed out as outstanding component of active dressings for diabetic wounds.

One-step electrospun scaffold of dual-sized gelatin/poly-3-hydroxybutyrate nano/microfibers for skin regeneration in diabetic wound.

This work aimed to implement an electrospinning protocol that allows simultaneous production of micro- and nanofibers in a single scaffold to mimic the extracellular matrix (ECM) combining biodegradable polymers and proteins, and to evaluate its capability to manage diabetic wounds. Poly-3-hydroxybutyrate (PHB) and gelatin (Ge) were chosen to prepare micro- and nanofibers, respectively. Electrospinning conditions were optimized testing various polymer concentrations, voltages, and flow rates. One-step dual-size fibers were obtained from 8%w/v PHB in chloroform (microfibers, 1.25 ± 0.17 µm) and 30%w/v gelatin in acetic acid (75%w/v) (nanofibers, 0.20 ± 0.04 µm), at 0.5 mL/h and 25 kV. A chemical characterization, swelling, hydrophilicity of scaffolds made of PHB-microfibers, Ge-nanofibers and their combination (Ge-PHB) were evaluated before and after crosslinking with genipin. All scaffolds showed excellent fibroblasts viability and attachment after incubation for 1, 3, and 7 days, and low levels of hemolysis. In vivo wound healing was evaluated in diabetic rats for 21 days. Ge-containing scaffolds promoted faster healing. The wounds treated with the Ge-PHB scaffolds proved to be in a late proliferative stage showing higher content of hair follicles and sweat glands and lower content in fibroblast compared with the control wounds.

Evaluation of marine algae Undaria pinnatifida and Porphyra purpurea as a food supplement: composition, nutritional value and effect of intake on intestinal, hepatic and renal enzyme activities in rats.

BACKGROUND: There is a long tradition in Eastern countries of consuming seaweeds, although demand for these organisms has also increased in Western countries. However, knowledge of the effects of consumption of algae is limited. In this study the proximate composition and amino acid profile of Undaria pinnatifida (Harvey) Suringar (wakame) and Porphyra purpurea (Olivi) De Toni (nori) were determined. The effects of feeding diets containing 100 g kg(-1) of wakami or nori for 4 weeks on food intake, growth, protein efficiency ratio, diet conversion ratio and some organ weights in growing rats were evaluated. The effects on intestinal, hepatic and renal enzyme activities were also studied. RESULTS: Both algae are a good source of protein, particularly nori, and contain essential amino acids. There was no effect of alga consumption on trophic balance. Intestinal disaccharidase and hepatic and renal γ-glutamyl transpeptidase activities were lower in alga-fed rats than in the control group, while intestinal leucine aminopeptidase activity was higher in rats fed algae. CONCLUSION: Both seaweeds are a good source of protein and carbohydrates and contain all essential amino acids. The effects of the two algae on enzyme activities were similar. The inhibition of intestinal disaccharidase activity by seaweed ingestion could be interesting in patients with altered glucose homeostasis.

Evaluation of the marine alga Ulva rigida as a food supplement: effect of intake on intestinal, hepatic, and renal enzyme activities in rats.

The use of seaweeds as a food is more widespread in Eastern than in Western countries, although demand for these plants has increased in the West because their possible usefulness as dietary supplements. However, very little is known about the effects of regular consumption of algae. The aim of the present study was to determine the composition of Ulva rigida and to evaluate the effects of dietary supplementation of the diet with 10% alga for 4 weeks on dietary intake, growth, protein efficiency ratio, diet conversion ratio, and some organ weights in growing male rats. We also studied the effect of inclusion of the alga in the diet on intestinal, hepatic, and renal enzymatic activities. U. rigida was found to be a good source of protein and carbohydrates. Food intake was higher in the U. rigida group than in the control group, but ingestion of alga did not have any effect on the other trophic parameters. The intestinal disaccharidase and leucine aminopeptidase activities were lower in rats fed with alga than in control rats, but γ-glutamyl transpeptidase activity was higher in the kidneys of alga-fed rats than in control rats. U. rigida contains high amounts of protein, carbohydrates, vitamins, and minerals and low amounts of lipids. Analysis of the amino acid composition revealed good-quality protein. The addition of alga to the diet inhibited disaccharidase activities, which suggested that alga consumption could be useful in some chronic disorders associated with pertubations of glucose homeostasis caused by carbohydrate absorption.

Composition, nutritional aspects and effect on serum parameters of marine algae Ulva rigida.

BACKGROUND: Algae are commonly consumed in Asia and have also gained popularity in Europe. However, data on the bioavailability of their components are limited. The present study was designed to determine the composition of Ulva rigida and the effects of inclusion of 10% of the algae in a standard diet for 4 weeks on nutritive value and serum parameters in order to consider the usefulness of Ulva as a dietary supplement. RESULTS: Ulva rigida is rich in protein, carbohydrates, fibre, vitamins and minerals and has a low lipid content. Analysis of the amino acid composition revealed good-quality protein. The algae were well accepted by experimental animals and did not significantly change nutritional parameters but reduced LDL cholesterol. CONCLUSIONS: Ulva rigida is an excellent source of nutrients and could improve a balanced diet. Further studies are required to research the potential of the seaweed as a natural source of bioactive compounds.