Characterization of catechol derivative removal by lignin peroxidase in aqueous mixture

The use of lignin peroxidase (LIP) as an alternative method for the removal of four catechols (1,2-dihydroxybenzene): catechol (CAT), 4-chlorocatechol (4-CC), 4,5-dichlorocatechol (4,5-DCC) and 4-methylcatechol (4-MC) typical pollutants in wastewater derived from oil and paper industries, was evaluated. The removal of 2mM catecholic substrates by 1 microM LIP after 1h was in the following order: 4,5-DCC (95%)>4-CC(90%)>CAT(55%)>4-MC(43%). Except for 4-MC, all reactions were accompanied by the formation of insoluble products, leading to LIP precipitation. LIP was exposed to soluble or insoluble product-dependent inactivation, depending on the substrates tested, immediately at the start of the reactions. Despite immediate enzyme inactivation, removal of catecholic substrates continued, resulting in oligomeric product formation. Major oxidation products analyzed were compatible with dimeric, trimeric and tetrameric structures. Ether linkages and a benzoquinone structure were detected in two purified oligochlorocatechols. Catechol derivatives removal initiated by LIP, seems to be different for each catecholic substrate in terms of substrate consumption and transformation, and of enzyme activity.

[Stabilizers of horseradish peroxidase]

Keeping an enzyme in its native form with high catalytic activity is of great significance. In the present study, thermal stabilizers of horseradish peroxidase (HRP) were screened. The results indicated that thermal stability of HRP was enhanced by magnesium sulphate and gelatin. A synergic effect of magnesium sulphate and gelatin was observed. In the presence of the stabilizer, the enzymatic activity of HRP remained 89% after kept for 80 h at 50 degrees C and 57% for 90 days at room temperature. Thermal alterations of HRP structure in the absence and presence of the stabilizers were explored by using UV absorption spectra at 402 nm (Soret band), intrinsic fluorescence and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence. The results suggested that magnesium sulphate and gelatin attenuated the extent of unfolding of HRP and therefore the native enzyme structure was stabilized.

Hydroxyethyl starch 130/0.4 versus modified fluid gelatin for cardiopulmonary bypass priming: the effects on postoperative bleeding and volume expansion needs after elective CABG

Concerned about high dose starches and potential coagulopathy, we performed a double blinded randomised prospective study on the influence of gelatine or 6% HES 130/04 pump prime on postoperative blood loss and transfusion requirements after CABG surgery.

METHODS

After informed consent, 157 electively scheduled patients were randomly allocated to 6% HES (n=85) or gelatine (n=72) CPB priming. Postoperatively, chest tube drainage was noted hourly during the first 24 hours and every unit of colloid, albumin, FFP or Packed Red Cells needed to maintain hemodynamic stability was carefully registered. Blood losses were standardised as ml blood loss/kg body weight. Three patients in the HES group were excluded from the study because of postoperative haemorrhage of pure surgical origin. Data analysis consisted in unpaired t-test and Fisher exact test where appropriate.

RESULTS

Chest tube drainage was significantly higher at 1 hour in the HES group (2.38 ml/kg vs. 3.15 ml/kg, p = 0.03). At 24 hours, total blood loss was still higher in the HES group without reaching statistical significance (p = 0.07). Albumin supplements occurred more frequently in the HES group between 2 and 3 hours postoperatively (p = 0.02). Total artificial colloid supplement was significantly higher in the gelatin group (13.36 versus 8.96 ml/kg, p < 0.001). There were no differences in the number of packed red cells, fresh frozen plasma or platelets transfused between the two groups.

CONCLUSION

6% HES 130/0.4 is a safe alternative to gelatine pump prime with a volume effect persisting longer in the postoperative phase, mandating less volume expansion with artificial colloid during the first 24 postoperative hours and not causing additional allogeneic blood component exposure.

[Infusion solutions of gelatin derivates]

Besides crystalloids, colloids are used for the treatment of hypovolemia and shock. They are high-molecular-weight proteins of bovine origin with properties of more rapid replacement of circulating blood volume. Iso-oncotic character provides the volume effect (approximately equal to 100%) close to the volume intravenously infused with the duration of action for 2-4 hours. Gelatin solutions are excreted with urine and feces in unchanged form without prolonged fixation in organism. Even in case of acute renal failure, gelatin peptides do not accumulate due to increased activity of proteolytic enzymes; therefore, they are the first-choice colloids. Gelatin solutions do not change coagulation as other colloids; just they may cause hemodilution as crystalloids do, so they are safe in case of hemorrhage and thrombocytopenia. There is a decreased risk of bleeding when gelatin solutions are used in surgery as compared with other colloids; in addition, they protect from hypotension due to vasodilatation in epidural or spinal analgesia. Gelatin solutions may cause compensatory hyperemia and increase of cardiac output, cardiac index, myocardial contractility, mean arterial blood pressure, and diuresis; in addition, oxygen delivery to the tissues improves. The dosage depends on clinical condition of a patient, and it is suggested to be 100-2000 mL and even more, for isovolemic hemodilution--20 mL/kg of body weight. Adverse reactions such as anaphylactoid or anaphylactic to gelatin derivates are rare and similar to other colloids.

Effect of renal embolization with trisacryl and PAVc

OBJECTIVES

Evaluate the degree of vascular occlusion, vascular recanalization, and necrosis of the vascular wall caused by polyvinyl alcohol-covered polyvinyl acetate (PVAc) particles compared to trisacryl particles after renal embolization.

METHODS

Seventy-nine female albino New Zealand rabbits underwent arterial catheterization of the right kidney. Thirty-three animals were embolized with trisacryl particles, thirty-one with PVAc particles, and fifteen were kept as controls. Four animals were excluded (three trisacryl and one PVAc) due to early death. Five subgroups of six animals were created. The animals in the different groups were sacrificed either 48 hours, 5 days, 10 days, 30 days, or 90 days after embolization. The control group was divided into subgroups of three animals each and kept for the same periods of time. The kidneys were dyed with hematoxylin-eosin and Masson's trichrome and then examined using optical microscopy.

RESULTS

There were significant differences in the degree of vascular occlusion caused by the trisacryl and the PVAc particles between the five-day and the ten-day groups. Additional differences were noted between the five-day and 48-hour groups in regard to the amount of necrosis. For both findings, the PVAc group members showed adequate tissue reaction (ischemia and volumetric reduction) and less recanalization than those treated with trisacryl.

CONCLUSION

The use of PVAc as an embolization material exhibited an adequate tissue reaction (ischemia and volumetric reduction), more expressive vascular occlusion and necrosis, and less recanalization than the trisacryl material.

[Influence of different gelatin concentration and lymphocyte isolation liquid on primary culture of umbilical cord blood derived adhesive cells]

In order to study the influence of different gelatin concentrations, and lymphocyte isolation liquid on primary culture of umbilical cord blood-derived adhesive cells (hCBACs), the red blood cells of umbilical cord blood was separated by 3% and 6 % gelatin for detecting the effectiveness of sedimentation, then the adhesion rate at 48 hours, the day of initial expansion and the rate of culture success were detected for hCBACs cultured with CD34(+) cells after the mononuclear cells were separated by 6% gelatin followed by Ficoll and Percoll, and the morphological characteristics and growth status were observed by invert microscopy. Cytochemistry stain for nonspecific esterase stain (NSE), peroxidase (POX), periodic acid Schiff reaction (PAS) and alkali phosphatase (ALP) and immunocytochemistry labeling for CD31, CD45, CD68 and fibronectin (Fn) were detected. The results showed that 6 % gelatin was better than that 3% gelatin for red blood sedimentation. The Percoll was predominant over Ficoll in adhesion rate at 48 hours, the day of initial expansion, the time of initial formation of adhesive cell colony units, the time of maximal numbers of adhesive cell colony units, the the cell fusion time and ratio of culture success. 60% fibroblast-liked cells, 36% macrophage liked cells and 4% small-round cells were observed in cells isolated by both isolated methods. The cytochemistry stain for NSE, POX, PAS and ALP was similar in two groups, the difference was not statistically significant between these two groups. The immunocytochemistry labeling for CD31, CD45, CD68 and Fn was also similar in both groups and the difference was also not statistically significant between these two groups. It is concluded that the combination of 6% gelatin with Percoll is an ideal separation method for primary culture of hCBACs, which provides basic information for clinical application.

Laminin-511 but not -332, -111, or -411 enables mouse embryonic stem cell self-renewal in vitro

We tested specific laminin (LN) isoforms for their ability to serve as substrata for maintaining mouse embryonic stem (ES) cells pluripotent in vitro in the absence of leukemia inhibitory factor or any other differentiation inhibitors or feeder cells. Recombinant human LN-511 alone was sufficient to enable self-renewal of mouse ES cells for up to 169 days (31 passages). Cells cultured on LN-511 maintained expression of pluripotency markers, such as Oct4, Sox2, Tert, UTF1, and Nanog, during the entire period, and cells cultured for 95 days (17 passages) were used to generate chimeric mice. LN-332 enabled ES cells proliferation but not pluripotency. In contrast, under the same conditions LN-111, Matrigel, and gelatin caused rapid differentiation, whereas LN-411 and poly-d-lysine did not support survival. ES cells formed a thin monolayer on LN-511 that differed strikingly from typical dense cluster ES cell morphology. However, expression of pluripotency markers was not affected by morphological changes. The effect was achieved at low ES cell density (<200 cell/mm(2)). The ability of LN-511 and LN-332 to support ES cell proliferation correlated with increased cell contact area with those adhesive substrata. ES cells interacted with LN-511 via beta1-integrins, mostly alpha6beta1 and alphaVbeta1. This is the first demonstration that certain extracellular matrix molecules can support ES cell self-renewal in the absence of differentiation inhibitors and at low cell density. The results suggest that recombinant laminin isoforms can provide a basis for defined surface coating systems for feeder-free maintenance of undifferentiated mammalian ES cells in vitro. Disclosure of potential conflicts of interest is found at the end of this article.

Polymeric Enhancers of Mucosal Epithelia Permeability: Synthesis, Transepithelial Penetration-Enhancing Properties, Mechanism of Action, Safety Issues

Transmucosal drug administration across nasal, buccal, and ocular mucosae is noninvasive, eliminates hepatic first-pass metabolism and harsh environmental conditions, allows rapid onset, and further, mucosal surfaces are readily accessible. Generally, however, hydrophilic drugs, such as peptides and proteins, are poorly permeable across the epithelium, which results in insufficient bioavailability. Therefore, reversible modifications of epithelial barrier structure by permeation enhancers are required. Low molecular weight enhancers generally have physicochemical characteristics favoring their own absorption, whereas polymeric enhancers are not absorbed, and this minimizes the risk of systemic toxicity. The above considerations have warranted the present survey of the studies on polymeric transmucosal penetration-enhancers that have appeared in the literature during the last decade. Studies on intestinal permeation enhancers are also reviewed as they give information on the mechanism of action and safety of polymers. The synthesis and characterization of polymers, their effectiveness in enhancing the absorption of different drugs across different epithelium types, their mechanism of action and structure-efficacy relationship, and the relevant safety issues are reviewed. The active polymers are classified into: polycations (chitosan and its quaternary ammonium derivatives, poly-L-arginine (poly-L-Arg), aminated gelatin), polyanions (N-carboxymethyl chitosan, poly(acrylic acid)), and thiolated polymers (carboxymethyl cellulose-cysteine, polycarbophil (PCP)-cysteine, chitosan-thiobutylamidine, chitosan-thioglycolic acid, chitosan-glutathione conjugates).

Hydrogel-elastomer composite biomaterials: 3. Effects of gelatin molecular weight and type on the preparation and physical properties of interpenetrating polymer networks

To optimize the preparation of a gelatin-HydroThane Interpenetrating Polymer Network (IPN) and obtain optimum physical properties for its use as a wound dressing, we studied IPN films prepared with two types of gelatin having different molecular weights. The effects of the gelatin molecular weight and type on the IPN film's structure, morphology, swelling and mechanical properties were determined. While FTIR did not reveal any noticeable differences between the IPNs prepared using different gelatin, light microscopy showed a lesser phase separation of the film prepared with a high-molecular-weight type A gelatin. Furthermore, these films displayed slightly less swelling, higher strength and lower strain, compared to the IPNs prepared with either low-molecular-weight type A or type B gelatin. The IPN prepared with type B gelatin showed higher swelling in serum-containing medium than those prepared with type A gelatin, because of its ionic charges under the condition. Increases in viscosity were observed with increasing molecular weight, type A being more viscous than type B gelatin despite having a lower bloom number. The viscosity of the high-molecular-weight gelatin was in the same magnitude as that of HydroThane, which might lead to less phase separation. A better understanding of the effects of alterations in the gelatin molecular weight and type on the formation and properties of the gelatin-HydroThane IPN should facilitate the development of promising composite biomaterials for wound dressing applications.

Porous bioceramics reinforced by coating gelatin

Porous bioceramics with high porosity for bone tissue engineering were fabricated by the foam impregnation technique, but their mechanical strength was poor, only a mean compressive strength of 1.04+/-0.15 MPa and an mean elastic modulus of 0.1 GPa. In order to reinforce porous ceramics, the ceramic samples were immersed in 5% gelatin solution and gelatin coatings were formed on the inter-surface of their pores. It was found that the mean compressive strength value and the mean elastic modulus value of porous samples coated with gelatin were improved to 5.17+/-0.17 MPa and 0.3 GPa respectively without sacrificing their porosity greatly. Moreover composite samples were not as fragile as sintered ceramics. The results indicated that the gelatin coatings on the inter-surface of pores reinforced porous bioceramics effectively.

Recombinant human gelatin nanoparticles as a protein drug carrier

Considerable attention has been directed to the application of natural gelatin-based nanoparticles. However, there are still critical problems associated with a safety issue of animal-origin gelatins, heterogeneous molecular weight, subsequent nanoparticle size distributions and use of toxic cross-linker. The purpose of this study was to develop a simple, safe and reproducible preparation method of recombinant human gelatin (rHG) nanoparticles via a modified desolvation method using a natural cross-linker for protein drug delivery. The model protein, FITC-BSA, was released from rHG nanoparticles in a biphasic and sustained-release pattern without initial burst. Optimized nanoparticles based on rHG and a natural cross-linker were prepared for the first time and showed great potential for protein drug delivery in terms of sustained release, less initial burst, and safety. In addition, rHG nanoparticles were efficiently internalized in the cell and mainly localized in the cytoplasm without significant cytotoxicity. Overall, these results suggest that rHG nanoparticles are appropriate for a protein drug delivery system with minimal toxicity.

Detection and quantification of classical swine fever virus in air samples originating from infected pigs and experimentally produced aerosols

During epidemics of classical swine fever (CSF), neighbourhood infections occurred where none of the 'traditional' routes of transmission like direct animal contact, swill feeding, transport contact or transmission by people could be identified. A hypothesized route of virus introduction for these herds was airborne transmission. In order to better understand this possible transmission route, we developed a method to detect and quantify classical swine fever virus (CSFV) in air samples using gelatine filters. The air samples were collected from CSFV-infected pigs after experimental aerosolization of the virus. Furthermore, we studied the viability of the virus with time in aerosolized state. Three strains of CSFV were aerosolized in an empty isolator and air samples were taken at different time intervals. The virus remained infective in aerosolized state for at least 30 min with half-life time values ranging from 4.5 to 15 min. During animal experiments, concentrations of 10(0.3)-10(1.6)TCID(50)/m(3) CSFV were detected in air samples originating from the air of the pig cages and 10(0.4)-10(4.0)TCID(50)/m(3) from the expired air of infected animals. This is the first study describing the isolation and quantification of CSFV from air samples originating from infected pigs and their cages, supporting previous findings that airborne transmission of CSF is feasible.

A novel bone substitute composite composed of tricalcium phosphate, gelatin and drynaria fortunei herbal extract

The Chinese herb, Gu-Sui-Bu (GSB) (Drynaria fortunei J. Sm.) has been anecdotally reported to enhance bone healing. We had previously confirmed in vitro the efficacy and safety of GSB in bone healing, and showed that it influenced both osteoblast and osteoclast activity. For clinically useful application of these bone regenerative effects, a satisfactory delivery system for GSB is required. In this study, we determined the optimal concentration of GSB for regenerative activity in rat bone cells via MTT, alkaline phosphatase (ALP), nodule formation and TRAP assays, and designed and tested a GSB-rich bone composite material. The composite was fabricated by mixing a biodegradable GGT composite, containing genipin cross-linked gelatin and tricalcium phosphate, with the predetermined concentration of GSB (GGT-GSB). Neonatal rat calvarial culture and animal implantation were employed to evaluate and compare in vitro and in vivo the potential of GGT-GSB and GGT in regeneration of defective bone tissue. The most effective concentration of GSB was 100 mug/mL, which significantly increased osteoblast numbers, intracellular ALP levels and nodule numbers, without influencing osteoclast activity. In vitro and in vivo tests also showed that GGT-GSB accelerated bone regeneration compared to GGT. GGT-GSB thus has great potential for improved bone repair.

The pro-angiogenic characteristics of a cross-linked gelatin matrix

To overcome limitations on regeneration in the nervous system and other organs caused by insufficient blood supply, we have developed a gelatin sponge material which stimulates blood vessel formation, i.e. angiogenesis. Controlled chemical cross-linking was employed to slow down enzymatic degradation of the gelatin matrix. Four different in vitro assays using L929 fibroblasts and purified endothelial cells indicated that the sponge material did not release toxic components, but provided a permissive substratum for cell attachment, cell migration and pronounced cell proliferation, all of which are crucial for the formation of vasculature. Two in vivo models were employed to directly monitor the pro-angiogenic impact of the sponge material. Implantation of gelatin sponges onto the chorioallantoic membrane of fertilized chicken eggs induced robust attraction of endothelial cells and formation of blood vessels. Angiogenesis inside gelatin implants occurred more than 200 times faster than in a commercial collagen sponge. Similarly, after subcutaneous implantation of tube-like sponges into mice, an increasing immigration of cells and subsequent formation of functional vasculature became evident. Immunocytochemistry revealed no fibronection accumulation and no scarring. In summary, our matrix based on cross-linked gelatin promises to be a valuable component of future implants, improving neuronal and non-neuronal regeneration by concomitant pro-angiogenic stimulation.

Immobilization of drugs for glaucoma treatment

Recently there have been some developments in the preparation of controlled drug delivery systems for glaucoma. Many materials are being used in this area, namely gelatine and chitosan. Both of them present high levels of biocompatibility and biodegradability. In this paper, we wish to report the work we have been doing on the preparation and characterization of hydrogels based on gelatine and chitosan. The crosslinking agents used were 1-(3-(Dimethylamino)propyl)-3-Ethylcarbodiimide hydrocholide (CDI), 1,4-Butanodiol diglycidyl ether (epoxyde 1), Ethylene glycol diglycidyl ether (epoxyde 2) and genipin. The results obtained showed that all of the films were hydrogels. The surface and transversal cut showed a porous surface in all the films. The thermal analysis proved the modifications in the polymeric chains, with the stabilization of all of them by the crosslinking agents. The release pattern indicates that the gelatine films were the best since they release the adequate proportion of drug. Finally, the cytotoxicity showed that the gelatine films were all biocompatible, specially the ones crosslinked with one of the Epoxydes.

Lycopene inhibits PDGF-BB-induced signaling and migration in human dermal fibroblasts through interaction with PDGF-BB

In melanoma development and progression, platelet-derived growth factor (PDGF) has been suggested to modulate the microenvironment, especially stromal fibroblasts, to the benefit of melanoma growth, invasion, and metastasis. Lycopene, a natural carotenoid that is abundant in tomato, has been shown to inhibit proliferation of several types of cancer cells. However, little attention has been paid to skin fibroblasts and melanoma cells. In the present study, we determined the effects of lycopene on stromal fibroblasts and their interactions with melanoma cells. We found that lycopene inhibited PDGF-BB-induced human Hs68 skin fibroblast migration on gelatin and collagen. Further analysis showed that lycopene inhibited PDGF-BB-induced signaling in human Hs68 and primary cultured skin fibroblasts. PDGF-BB-induced phosphorylation of PDGF receptor beta (PDGFR-beta), extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and c-Jun N-terminal kinase (JNK) was attenuated by lycopene in a concentration-dependent manner, whereas the total expression of each protein was not affected. Interestingly, dot binding assay revealed that lycopene could directly bind to human PDGF-BB in PBS and human plasma, indicating that lycopene can bind to PDGF-BB in both in vitro and in vivo conditions. In functional studies, lycopene inhibited melanoma-induced fibroblast migration in a noncontact coculture system and attenuated signaling in fibroblasts simulated by melanoma-derived conditioned medium. Our results provide the first evidence showing that lycopene is an effective inhibitor of migration of stromal fibroblasts and this effect may contribute to its antitumor activity.

Hemostatic properties of a venomic protein in rodent dermal injuries

Hemostatic properties of a factor Xa-like protease (Q8009) from the Australian snake Pseudonaja textilis textilis were determined. In tail-tip transection and dermal incision (hind limb) models, reagents were applied with collagen matrix. Blood was collected on filter paper chads for 12 one-minute intervals or until hemostasis. Determination of blood loss was performed using the hematin content and reported as blood loss per minute and total blood lost. Results from the studies demonstrated that the addition of the protease Q8009 and collagen matrix significantly reduced the volume of blood loss and shortened the time-to-hemostasis. In the dermal incision model, Q8009 (100, 250 and 1000 microg/ml) plus collagen matrix significantly reduced (p<0.001) the volume of blood lost relative to Thrombin and shortened the time-to-hemostasis to 2.0 min compared to 4.77 min with Thrombin. In the tail-tip transection model when Q8009 was mixed with a collagen matrix there was no significant reduction in blood loss, when compared to Thrombin plus collagen matrix. However, when injured tail-tips were held in Q8009 (1000 microg/ml) solution, there was a significant reduction (p<0.001) in blood loss (5.88 microl) versus that of Thrombin at 58.0 mul, and time-to-hemostasis was reduced from 11 min with Thrombin to 3 min when the Q8009 solution was used. In these studies, topical application of the venomic protease Q8009 significantly reduced total blood loss with a shorter time-to-hemostasis relative to Thrombin.

Effects of albumin 5% and artificial colloids on clot formation in small infants

Albumin is often cited in textbooks as the gold standard for fluid replacement in paediatrics, but in practice artificial colloids are more frequently used. Although one concern with the use of artificial colloids is their intrinsic action on haemostasis, the available data in children are inconclusive for 6% hydroxyethyl starch 130/0.4 (HES) and no data exist for gelatine solution with respect to coagulation. A total of 42 children (3-15 kg) undergoing surgery and needing colloid replacement were randomly assigned to receive 15 mlxkg(-1) of either albumin 5%, 4% modified gelatine solution or 6% hydroxyethyl starch 130/0.4 solution. Standard coagulation tests and modified thrombelastography (ROTEM) were performed. After colloid administration, routine coagulation test results changed significantly and comparably in all groups, although activated partial thromboplastin time values increased more with gelatine and HES. Coagulation time was unchanged in the children who received albumin or gelatine but other activated modified thrombelastography values were significantly impaired in all groups. After gelatine and after albumin the median clot firmness decreased significantly but remained within the normal range. Following HES, coagulation time increased significantly, and clot formation time, alpha angle, clot firmness, and fibrinogen/fibrin polymerisation were significantly more impaired than for albumin or gelatine, reaching median values below the normal range. From a haemostatic point of view it might be preferable to use gelatine solution as an alternative to albumin; HES showed the greatest effects on the overall coagulation process.

Experimental comparative study in rabbits of three different ways of cartilage graft fixation: suture, gelatin-resorcin-formaldehyde and butyl-2-cyanoacrylate

CONCLUSION

The compound gelatin-resorcin-formaldehyde (GRF) was a better stabilizing material for cartilage grafts in rabbits than butyl-2-cyanoacrylate. GRF was also better than the suture when comparing fixation of cartilage to the periosteum and inflammatory reaction.

OBJECTIVE

Cartilage grafting is an interesting option for refinements on rhinoplasties. The objective of this study was to compare butyl-2-cyanoacrylate to GRF and suture to determine the efficacy of these methods in restraining grafted cartilage in rabbits.

MATERIALS AND METHODS

Fifteen male adult New Zealand rabbits underwent surgery with the aim of collecting six auricular cartilage grafts from each animal. Two of these grafts in each animal were glued together with butyl-2-cyanoacrylate, two were glued together with compound GRF, and two were sewn together with nylon suture. These sandwich grafts were then glued or sutured to the periosteum of the glabella. After 2, 6, and 12 weeks, groups of five animals were sacrificed and histological analysis for inflammation was performed. Cartilage graft migration, adhesion, and deformities of the grafts were also evaluated.

RESULTS

There was less migration of the cartilages glued with GRF than with cyanoacrylate and suture. GRF showed statistically less inflammatory reaction and angiogenesis than the other two methods. The three methods showed a tendency to decrease of fibrosis, inflammation, and angiogenesis as weeks passed. There was no detachment or deformity in the cartilage sandwiches sutured to the glabella's periostium. The majority of detached and deformed cartilages were those glued with cyanoacrylate. The number of detached cartilages was directly related to the number of deformed cartilages. The data were statistically significant (p<0.05).

Effects of fibrin sealer and resorbable gelatin on the repair of osseous defects in rat tibia

Gelfoam - a biologically resorbable gelatin sponge - has the function of restricting hemorrhage, providing platelet rupture, and supporting fibrin threads. Beriplast - a fibrinogen-thrombin compound - is used to adhere tissues, to consolidate sutures and in hemostasis. The objective of this study was to perform a histological analysis of the effects of haemostatic agents on osseous repair. These materials were inserted into surgical sites in young rat right and left tibiae. After the observation periods of 7, 14, 30 and 45 days, according to the bioethic protocol, the animals were killed, the tibiae were removed and fixed in 10% formalin and decalcified in equal parts of formic acid and sodium citrate solutions. After routine processing, the specimens were embedded in paraffin for microtomy. Analysis of the results demonstrated that the haemostatic agents are effective in controlling hemorrhage; they stimulate osteogenesis, featuring a pattern of osseous tissue formation similar to the control pattern, although the amount of osseous trabeculae was superior, especially in the Gelfoam group in the periods of 7 and 14 days; 30 days after surgery, the delay in tissue healing in the control group in relation to the experimental groups started to decrease, and the control and experimental groups exhibited similar tissue repair after 45 days, when all the groups exhibited secondary osseous tissue.

Volume therapy with colloid solutions preserves intestinal microvascular perfusion in endotoxaemia

Colloid solutions have been suggested to improve microvascular perfusion due to their anti-inflammatory properties. Whether this also applies for the gut, an important immunological organ vulnerable to hypoperfusion is unknown. This study investigated intestinal microcirculation of endotoxaemic rats after volume therapy with colloid solutions such as hydroxyethyl starch (HES) and gelatin or isotonic saline (NaCl). In addition intestinal oxygenation and morphology as well as mesenteric leukocyte-endothelium interaction were quantified. Rats were anaesthetised with urethane and ketamine, mechanically ventilated, and monitored haemodynamically. Normotensive endotoxaemia was induced by a continuous intravenous infusion of Escherichia coli lipopolysaccharide (LPS, 1.5 mg kg(-1) h(-1)). After 1 h of LPS infusion either 6% HES (16 ml kg(-1)), 4% gelatin (16 ml kg(-1)) or 0.9% NaCl (64 ml kg(-1)) were infused for 1 h. Using intravital microscopy, functional capillary density (FCD) and red blood cell velocity (RBCV) were measured in the mucosa of the terminal ileum at baseline and 3 h after volume therapy. In another set of animals, mesenteric leukocyte-endothelium interaction was determined 3 h after volume therapy. In all animals intestinal lactate/pyruvate ratio and intestinal morphology were assessed. Three hours after volume therapy, FCD decreased in NaCl (808 [749/843] cm(-1); median [quartiles] P<0.05 versus baseline) but not in HES (995 [945/1036] cm(-1)) and gelatin (988 [867/1193] cm(-1)) groups. RBCV, lactate/pyruvate ratio and intestinal morphology did not differ among groups. Also mesenteric leukocyte-endothelium interaction was not significantly influenced by either treatment. In conclusion, early volume therapy with HES or gelatin, but not with NaCl, preserved gut microvascular perfusion during endotoxaemia but did not have a significant effect on tissue oxygenation nor morphological appearance in this experimental model. An anti-inflammatory effect of colloid solutions was not seen and fails to explain the changes in intestinal microcirculation.

The effect of carbodiimide-derivatized hyaluronic acid and gelatin surface modification on peroneus longus tendon graft in a short-term canine model in vivo

PURPOSE

We have recently reported that application of carbodiimide-derivatized hyaluronic acid and gelatin (cd-HA gelatin) to a peroneus longus tendon graft increased tendon graft gliding ability and decreased work of flexion compared with untreated grafts in a canine model in vivo. In this study, we investigated the effect of this modification on adhesions, stiffness, strength of the distal attachment, and fibroblast count.

METHODS

A total of 24 dogs were used for this study. The peroneus longus tendons of each hind leg were grafted into the 2nd and 5th digits of one forepaw in each dog. One peroneus longus tendon was treated with cd-HA gelatin prior to grafting, and the other one was immersed in 0.9% saline solution as a control. Animals were killed 1, 3, or 6 weeks postoperatively.

RESULTS

The adhesion score of cd-HA gelatin-treated tendons was significantly less than that in the saline-treated tendons at all time points. There was no significant difference in the indentation stiffness between HA- and saline-treated grafts at any time point. For the ultimate force at the distal attachment, there was a significant difference among the time points, with a steady increase over time, but no significant difference between treated and control tendons at any time point. There was no significant difference in fibroblast count between treated and control tendons at any time point.

CONCLUSIONS

Although gross adhesion formation was less, there was no significant difference in strength at the distal tendon-bone interface, cellularity, or tendon graft stiffness when comparing saline-treated and cd-HA gelatin-treated tendon grafts in vivo.

Mechanical and biocompatible influences of chitosan fiber and gelatin on calcium phosphate cement

Calcium phosphate cement (CPC) is a widely used bone substitute in the clinic; however, the low strength of CPC limits its utilization. In this study, we investigated mechanical influences of chitosan fiber combined with gelatin on CPC, and examined the biocompatibility of the new composite with rat bone marrow stromal cells. Compared to the fiber impregnated in phosphate buffered saline (80.5 MPa), our study showed that tensile strength of chitosan fiber increased 106 and 114% with the impregnation of gelatin at the mass fraction 5 and 10%, although this increase was not statistically significant. It was demonstrated by Fourier transform infrared spectroscopy that the characteristic absorption bands of chitosan were changed with the addition of gelatin. The optimal flexural strength enhancement was obtained when CPC was reinforced with fiber at volume fraction of 30% and gelatin at mass fraction of 5% (maximum: 12.31 MPa). The fiber morphology was more compact when the chitosan fibers impregnated with gelatin at mass fraction of 5 or 10% than chitosan alone. The fracture analysis showed that the new CPC-chitosan fiber-gelatin composite presented many remnants of CPC adhered to fibers. Short minimum essential medium extract test showed no cell growth inhibition after the addition of the new composite. Rat bone marrow stromal cells retain the ability to spread and grow on the composite. Our studies demonstrated that the flexural strength is greatly increased by using CPC incorporated with proper ratio of CF and gelatin. More over, the new composite demonstrated biocompatibility in vitro.

[Effect of proteins pre-coating on bone marrow mesenchymal cells retention and proliferation on decellular bovine pericardium]

To observe the growth of rat bone marrow mesenchymal cells (BMMCs) on decellular bovine pericardia in vitro and to investigate the effect of proteins pre-coating on cells retention and proliferation, bovine pericardia were decellularized using trypsin, DNase and Triton X-100 respectively. Then three proteins (fibronetin (FN), gelatin, collagen I) were coated on the surfaces of the bovine pericardia separately. BMMCs were harvested from rat thighbone marrow , then expanded and seeded onto decellular bovine pericardia with the proteins pre-coated . Decelluar bovine pericardia without coating were used as controls. The retention and growth of BMMSCs were observed by Hochest staining and analyzed by MTT method. It was shown that the retention and proliferation of BMMCs on FN group and gelatin group were significantly enhanced comparing with those on collagen I group and control group (P < 0.001). There was no significant difference between FN group and gelatin group (P > 0.05), nor between collagen I group and control group (P > 0.05). We conclude that the retention and proliferation of seeding cells on FN and gelatin could be significantly improved on decellular bovine pericardia (DBP) but not on collagen I.

Influence of sex and estrous cycle on the effects of acute tryptophan depletion induced by a gelatin-based mixture in adult Wistar rats

Women are more vulnerable to develop depression and anxiety disorders than men. This may be related to higher serotonergic vulnerability in women. Serotonergic vulnerability entails that differences between people in the regulation of serotonin (5-HT) determine the vulnerability of an individual to develop depression or other 5-HT-related disorders. The aim of the present experiment was to evaluate whether male and female Wistar rats differ in serotonergic vulnerability. Here, a stronger behavioral response to acute tryptophan (TRP) depletion was assumed to reflect serotonergic vulnerability. Twenty-four male and 48 female rats were repeatedly subjected to treatment with a gelatin-based protein-carbohydrate mixture, either with or without L-tryptophan. Female estrous cycle phase was determined by means of vaginal smears and the females were divided into two groups based on their estrous cycle phase: pro-estrus/estrus and met-estrus/di-estrus. Blood samples showed stronger TRP depletion in males than females. There was no effect of estrous cycle on plasma TRP concentrations. In contrast, treatment effects on some brain TRP concentrations were influenced by estrous cycle phase, females in pro-estrus/estrus showed the strongest response to TRP depletion. In the open field test and home cage emergence test, females in pro-estrus/estrus also showed the strongest behavioral response to acute TRP depletion. In general, females showed more activity than males in anxiety-related situations and this effect appeared to be enhanced by TRP depletion. In the social interaction test, passive body contact in males and females in pro-estrus/estrus was decreased after TRP depletion whereas it was increased in females in the met-estrus/di-estrus phase. Acute TRP depletion affected object recognition, but did not affect behavior in the forced swimming test and a reaction time task. It is concluded that sex and estrous cycle phase can influence the behavioral response to TRP depletion, and that females in pro-estrus/estrus show the strongest behavioral response to acute TRP depletion.