As distinctive spontaneous polarization and far-infrared radiation characteristics, the natural mineral tourmaline (TM) has the regulatory effect on crystallization behavior, which possesses potential application in biomimetic mineralization and bone regeneration. In this study, polyurethane (PU) and gelatin (GE) membranes with different adding proportion of TM nanoparticles were prepared via electrospinning. Additionally, the effect of TM nanoparticles on the mineralization process of hydrophobic PU and hydrophilic GE was investigated by immersing the composite TM/PU and TM/GE electrospun membranes in the 10× simulated body fluid (10SBF) at 37 °C for varying periods of time. SEM images confirmed the well-dispersed TM nanoparticles in the PU and GE electrospun fibers. The mineralization deposition was characterized by the SEM, EDS, XRD, and FTIR, and it indicated that two types of calcium phosphate deposits with different Ca/P molar ratios were obtained when TM/PU membranes and TM/GE membranes were incubated in 10SBF. Honeycomb-like hydroxyapatite crystals nucleated and grew faster on TM/PU and TM/GE membranes than the pure PU and GE membranes, respectively. Furthermore, with the increase of the added TM nanoparticles in the composite membranes, more calcium phosphate crystals were precipitated. These results showed that the added TM nanoparticles were able to improve the mineralization of polymer fibrous membranes, which is potential for the composite bone scaffold.

The function of acid-activated sepiolite clay was evaluated for use in the clarification of apple juice. Optimizing the clarification process was done using response surface methodology (RSM) considering juice turbidity as a response. The efficiency of sepiolite in terms of clarification was compared to that of bentonite and a combination of these fining agents with gelatin and silica gel at optimal conditions. The conditions of 0.05% clay concentration at a temperature of 50°C for 7 h were deemed optimal in terms of juice clarification. The present results showed that treatment of sepiolitegelatin-silica gel was the most active fining agent with 99.7% reduction in apple-juice turbidity. The rate of turbidity, the viscosity, the total phenolic contents and the colour changes were fitted to first-, zero-, first- and zero-order kinetic models, respectively.

Introduction. Polyphenols have received significant attention in recent years due to their antioxidant capacity and their significant role in disease prevention. Cocoa is one of the major naturally occurring sources of antioxidants, particularly of polyphenolic compounds. Materials and methods. Gelatin nanoparticles loaded with a cocoa-derived polyphenolic extract were synthesized by nanoprecipitation. The nanoparticle synthesis was performed using a central composite experimental design that allowed for the assessment of how gelatin concentration and surfactant concentration (Tween 80) affected the hydrodynamic diameter and polydispersity of the particles. The nanoparticles were characterized using dynamic light scattering (DLS), assessments of zeta potential, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Results. The analyses demonstrated that the nanoparticles examined exhibited hydrodynamic diameters of (100 to 400) nm, polydispersity indices of less than 0.2 and average zeta potential values of 29–33 mV. SEM images revealed that most nanoparticles were spherical and uniform in morphology, with average sizes less than 250 nm. In vitro experiments in which the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used to assess the prevalence of free radical-scavenging ability among these nanoparticles indicated that the loading efficiency for the nanoparticles was approximately 77.56%. Conclusion. Nanoparticles loaded with polyphenolic extract were obtained with average sizes ranging from (120 to 250) nm and largely spheroidal morphologies. Polymer and surfactant concentrations significantly influenced the hydrodynamic diameters and polydispersity indices of the particles. The incorporation of the polyphenolic extract into the polymer matrix enabled the preservation of the antiradical activity of the bioactive compound.

Introduction. Mango is the most economically important and nutritionally rich tropical fruit; it has high commercial value but a highly perishable nature; its sensitivity to postharvest diseases and physical injury limits its successful marketing. Postharvest losses in fruits are a serious problem because of rapid deterioration during handling, transport and storage. Edible films and coatings can be potentially used as an elective preservation technique to extend the shelf life of fruits. Materials and methods. The influence of zein and gelatin coatings on the physicochemical characteristics, softening and antioxidative enzyme activities of mango fruits stored at (32 ± 1) °C were evaluated at regular intervals of their storage period and compared with mango without coatings (control). Results and discussion. Zein and gelatin coatings seemed to have a beneficial impact on delaying the changes in weight loss, soluble solids, titratable acidity, pH, sugar content and total carotenoids. Zein and gelatin coatings resulted in the highest retention of ascorbic acid and phenolic content as compared with that of control. Zein and gelatin coatings delayed the ripening of mango fruit by suppressing the activity of softening enzymes such as polygalacturonase, pectin methyl esterase, cellulase and β-galactosidase. Zein 5% and gelatin 10% coatings maintained the highest induction of defense-related peroxidase enzymes, followed by gelatin 5% and zein 10% coatings. Conclusion. The application of zein 5% and gelatin 10% coatings could be used in delaying the ripening, maintaining the quality attributes and extending the shelf life of mango fruit during storage.

Summary

Background and objectives: Colloids such as hydroxyethyl starch (HES), gelatin, dextran and albumin are useful for maintaining renal perfusion and function. The comparative renal effects of colloids have not been previously reviewed. Methods: Computer searches of the MEDLINE and EMBASE bibliographic databases and the Cochrane Library were conducted using the search terms: colloids; hetastarch; gelatin; dextrans; serum albumin; kidney failure; cardiac surgical procedures; and kidney transplantation. Relevant studies were also sought through hand searching and examination of reference lists. Results of identified studies were qualitatively summarized with account taken for potential confounding factors. Results: The three artificial colloids HES, gelatin and dextran all exhibited troublesome renal side-effects. Randomized trials have demonstrated adverse renal effects of HES in sepsis and surgery. Undesirable renal effects are common to all available HES solutions regardless of molecular weight, substitution or C2/C6 ratio. While some of its effects may be less severe than those of HES, gelatin also can adversely affect the kidney. A negative renal impact of dextran is well-established, although this colloid is now less extensively used than formerly. As the normal endogenous colloid, albumin exhibits a wide margin of renal safety, although albumin overdose needs to be avoided. Albumin also appears to exert protective effects on the kidney such as inhibition of apoptosis and scavenging of reactive oxygen species. Conclusions: Colloids display important differences in their actions on the kidney. These contrasting renal effects should be considered in making fluid management decisions.

Rhinophyma is considered to be the final stage of rosacea and has an unknown aetiology. We present two new surgical adjuncts for the treatment of this condition. The microdebrider is easy to use and allows precise contouring of the nose. It shares the same underlying principle as free-hand scalpel shaving but outperforms this method in key areas. We also describe a novel use for FloSeal®, a gelatin-thrombin co-mixture, utilizing its haemostatic properties to address bleeding from the re-shaped denuded nose.

The substrate specificity of porcine pepsin has been altered by site-directed mutagenesis in an attempt to selectively cleave bovine hide collagen at only a few sites, similar to cathepsin D, for the production of high quality gelatin. Kinetic parameters were determined using chromogenic peptide substrates based on the sequence Lys-Pro-Xaa-Yaa-Phe*Nph-Arg-Leu (where Xaa is Ile or Pro, Yaa is Glu, Leu, Gln or Lys, Nph is p-nitrophenylalanine, and * is the site of cleavage). Substitution of Thr222 and Glu287 within the S2 subsite of pepsin by Val and Met, respectively, produced a double mutant with a two- to fourfold higher kcat/Km, compared with wild-type pepsin, for the chromogenic peptides with residues Leu, Gln, and Glu at position P2 (Yaa). The results suggest that the functional group of the P2 side chain may be exposed to solvent, while the aliphatic portion interacts with hydrophobic residues comprising S2. Wild-type pepsin cleaved a peptide corresponding to the carboxy-terminal telopeptide region of bovine type I collagen α1 chain, SGGYDLSFLPQPPQE, predominantly at three sites (Asp-Leu, Leu-Ser, and Phe-Leu) and at a significantly lower rate at Ser-Phe. However, Thr222Val/Glu287Met cleaved site Ser-Phe at a rate 20-fold higher than the wild-type. Significantly, enzymes containing the double substitution Phe111Thr/Leu112Phe cleaved this peptide predominantly at one site Leu-Ser (similar to cathepsin D) and at a rate 23-fold higher than the wild-type. These mutants can potentially enhance the rate of solubilization of bovine hide collagen under conditions mild enough to maintain the triple helix structure and hence minimize the rate of subsequent denaturation and proteolytic cleavage.

A 120 d feeding study with adult rats was conducted to evaluate the influence of two protein sources (casein and gelatin), two protein levels (50 and 300g/kg diet) and two fat levels (50 and 150g/kg diet) on serum lipids (total cholesterol, HDL-cholesterol and triacylglycerols) and liver polyunsaturated fatty acid levels. In general, the concentrations of serum triacylglycerols and total cholesterol and liver phospholipid levels of arachidonic acid (AA) and docosahexaenoic acid (DHA) were higher in rats fed on casein diets compared with those fed on the gelatin diets. These effects were more pronounced in rats fed on the high-casein (300 g/kg)-high-fat (150g/kg) diet. Gelatin was hypocholesterolaemic and also suppressed the liver phospholipid levels of AA and DHA (reported for the first time). The difference in the amino acid composition between casein and gelatin may be responsible for the observed effects. Casein contains higher levels of glutamic acid, methionine, phenylalanine and tyrosine, while gelatin contains higher levels of arginine, glycine and hydroxyproline. It is suggested that a protein source which increases serum cholesterol may also increase the concentrations of AA and DHA in rat tissues.

The influence of haemodilution with colloids on somatosensory evoked potentials in non-premedicated volunteers is reported. In seven volunteers (randomized crossover design), blood (20 mL kg−1 within 30 min) was removed and simultaneously replaced by gelatin 3% or hydroxyethylstarch 6%. After 30 min, blood was retransfused within 30 min. Median and posterior tibial nerve somatosensory evoked potentials were recorded from the cortex, second cervical vertebra, Erb's point and 1st lumbar vertebra, respectively. One volunteer experienced a severe allergic reaction to gelatin, therefore only six gelatin trials were evaluated. Haemodilution decreased the haematocrit from 39.8 ± 1.6% (mean ± SD) to 31.1 ± 2.0% (gelatin) and from 40.7 ± 1.7% to 29.8 ± 1.5% (hydroxyethylstarch), respectively. Retransfusion increased haematocrit to 34.4 ± 0.9% (gelatin) and to 34.2 ± 1.3% (hydroxyethylstarch). Neither haemodilution with gelatin nor haemodilution with hydroxyethylstarch or retransfusion influenced evoked potentials. In conclusion, the treatment of blood loss up to 30% of estimated blood volume with gelatin or hydroxyethylstarch will not affect somatosensory evoked potential monitoring provided normovolaemic conditions are maintained.