Synthetic Sponge Research Articles

Experimental sinusitis in a rhinogenic model.

The objectives were to determine the optimal sinusitis induction period and to examine microbiological and histopathological changes of sinusitis recovery stage in a rhinogenic sinusitis model. A synthetic sponge was inserted into the right-side nasal cavities of rabbits. The sponge was impregnated with a Streptococcus pneumoniae strain in group 1 and with sterile saline solution in groups 2 and 3. After the fourth day of sponge insertion, sinuses were examined by coronal computed tomography scans at two-day intervals until any radiological evidence of sinusitis was observed. When sinusitis was detected radiologically, five rabbits each from groups 1 and 2 were killed for histological examination. To determine the recovery period of sinusitis, sponges were removed from the rest of the rabbits in groups 1 and 2. Rabbits were selected randomly and killed on the 15th and the 30th days of the recovery period, immediately after radiological examinations. Group 3 was considered a sham group. Sinusitis induction was performed in all rabbits in groups 1 and 2 until the 8th day. After the sponges were removed, inflammation persisted until the 30th day of the study. In a rhinogenic sinusitis model, although histological features of sinusitis were demonstrated, further studies are required to standardize this model and to examine whether or not the studied bacterial strain spreads from nasal cavity into sinus.

Evaluation of oral formulations of gentamicin containing labrasol in beagle dogs

Gentamicin (GM) is a polarized water-soluble compound having very poor intestinal membrane permeability resulting in low oral bioavailability. Labrasol was found to improve the intestinal absorption of GM in rats. In the present study, GM formulations containing labrasol were evaluated in beagle dogs after filling into hydroxypropylmethyl cellulose (HPMC) capsules wrapped with Eudragit L100 (Eud L) and Eudragit S100 (Eud S) films. The results of the in vitro drug release studies could not differentiate between two kinds of enteric capsules and among the three kinds of GM formulations. Oral administration of GM solution at a dose of 50.0 mg per dog of GM and 0.60 ml per dog of labrasol has resulted in C max values of 2.38±0.50 μg/ml and 2.30±0.42 μg/ml with Eud L and Eud S capsules, respectively. The AUC values obtained were also higher at 4.35±1.31 μg h/ml and 5.34±0.95 μg h/ml with Eud L and Eud S capsules, respectively. Formulation of GM as a suspension in labrasol has resulted in the decrease of C max values by two to four times and AUC values by >2.5 times compared to the solution formulation. The above results indicate that solution formulation was better over the suspension. An absorbent, synthetic sponge was used to absorb GM solution formulation and encapsulated with Eud L and Eud S capsules. The C max and AUC values obtained with sponge formulation were higher than those of suspension formulations but were lower than solution formulations. There was no significant difference in the extent of GM absorption between Eud L and Eud S capsules used for encapsulating GM formulations.

A macroscopic finite strain model for cellular polymers

Viscoelastic polymer foams and synthetic sponges are exploited in a wide range of engineering applications. The cellular micro structure, as a result of the foaming process, gives these porous materials their outstanding mechanical characteristics. However, this complex cellular structure demands for an appropriate model for the description at a suitable means of computational costs. The goal of this paper is to present an efficient, large strain, multiphasic continuum model based on the Theory of Porous Media (TPM) accounting for the porous cell structure, the moving and interacting pore-fluid and the intrinsic viscoelastic behaviour of the polymer solid matrix.

Development of biodegradable porous scaffolds for tissue engineering

Three-dimensional biodegradable porous scaffolds play an important role in tissue engineering. A new method of preparing porous scaffolds composed of synthetic biodegradable polymers was developed by combining porogen leaching and freeze-drying techniques using preprepared ice particulates as the porogen material. The pore structures of the polymer sponges could be manipulated by controlling processing variables such as the size and weight fraction of the ice particulates and the polymer concentration. The synthetic polymer sponges were further hybridized with collagen microsponges to prepare biodegradable hybrid porous sponges of synthetic polymer and collagen. The collagen microsponges were formed in the pores of synthetic polymer sponges. The hybrid sponges exhibited the advantages of both the synthetic polymers and collagen. Hybrid sponges of synthetic polymer, collagen, and inorganic hydroxyapatite were developed by depositing hydroxyapatite particulates on the surfaces of the collagen microsponges in the synthetic polymer–collagen sponges. The use of synthetic polymer sponge as a mechanical skeleton facilitated the formation of these hybrid sponges into desired shapes, contributed good mechanical strength and handling, while the collagen and hydroxyapatite facilitated cell seeding and promoted cell interaction.

Effects of Indole Derivatives on the Growth of Chlamydomonas spp. as Causal Green Algae in the Hydroponics System.

Some Indole derivatives were examined for their algicidal activity to Chlamydomonas reinhardtii and the isolate of Chlamydomonas sp. which was isolated from the green algae-generating hydroponic solution in the hydroponic trough of the greenhouse. Of nine compounds tested, 3-indolepropionic acid, 3-indoleacrylic acid and 3- (3-indolyl) butanoic acid could suppress multiplication of C. reinhardtii cells. Although the first one exhibited the strong phytotoxicity, the latter two compounds were effective at lower concentrations which did not cause any toxic effect on the growth of tomato seedlings. In addition, 3-indoleacrylic acid and 3- (3-indolyl) butanoic acid inhibited the multiplication of Chlamydomonas green algae which were actively growing in our hydroponic facilities, and suppressed the algal emergence on the synthetic sponge cubes soaked in the hydroponic solution which had been inoculated with green algae. The present study suggests that these compounds have a potential to be used as an algicide for the hydroponics of crop plants.

Sponges as visual aids - bath time fun for biologists?

Cheap and colourful teaching aids from synthetic sponges enhance learning through their flexibility

Acute sinusitis in the rabbit model: histologic analysis.

Characterize the histology of the rhinogenic model of sinusitis and compare this with existing models of sinusitis. Prospective controlled trial in animals. New Zealand white rabbits were implanted with a synthetic sponge, which was then impregnated with Streptococcus pneumoniae bacteria. After a specified time the animals were sacrificed, and whole-mount sectioning of both the infected and noninfected sinuses was performed. The sinuses were carefully examined for evidence of inflammatory changes. This model produced a sinus infection that is characterized by luminal exudates of neutrophils and eosinophils, mucosal infiltration with lymphocytes and plasma cells, and epithelial degeneration. In addition, discrete lymphoid follicles were identified in both the implanted and nonimplanted sides that in the implanted sides appear to hypertrophy and liberate leukocytes into the sinus lumen. Other areas were observed where luminal exudates seem to act on and degrade mucosa that has little or no underlying inflammation. In severely infected sinuses submucosal vacuole formation with overlying granulation tissue was observed. The rhinogenic model of sinusitis demonstrates features typical of other known models of sinusitis. In addition, there appear to be unique features of this model, specifically the identification of discrete lymphoid aggregates, which suggest that this model has the potential to be valuable for the study of the immune response of the sinuses.

An evaluation of sterilization of endodontic instruments in artificial sponges

The ability to sterilize endodontic files inserted into synthetic sponges was tested. Sponges were subjected to 5 cycles of either dry heat (Driclave) or steam under pressure (autoclave) sterilization. Sterilization was corroborated by microbiological tests. The sponges and files were pre-sterilized separately using steam under pressure. One hundred eighty files contaminated with Bacillus stearothermophilus spores (experimental and positive control) and 60 noncontaminated files (negative control), were inserted into 60 sponges. After each cycle, each file and a portion of sponge surrounding the file were transferred aseptically to tubes containing trypticase soy broth culture medium for bacteriological analysis. None of the tubes containing files and portions of sponges that were subjected to autoclave grew Bacillus stearothermophilus spores. Two of 60 (3.33%) of the tubes that were subjected to sterilization by Driclave demonstrated bacterial growth. Although the sponges tolerated the dry heat cycles well physically, sterilization was achieved in only 96.67% of the cases.

A simple and rapid method for collecting saliva to assess sodium status in sheepum

Fifteen lambs were fed diet with normal (0.11%) or deficient levels of sodium ( 0.035%), respectively, for five weeks on each diet. At the end of each period saliva was collected by three different methods: swabbing with a 5 x 5 x 1.25cm synthetic sponge, aspiration with a 15cm long plastic tube connected to a 20ml syringe and sucking with a 4mm x 45cm long plastic tube through a water-jet aspirator pump or an eletric motor pump. The volume of saliva collected/min and the salivary sodium: potassium ratio were analysed. Larger volume of saliva was obtained with the developed sucking apparatus than with the sponge or the syringe. There was no influence of the method of saliva collection on the values of salivary Na:K ratio in both periods. Nevertheless, the lower the sodium dietary level was, the smaller the salivary Na:K ratio. Five weeks of low sodium diet intake resulted in a decrease in the salivary Na:K ratio values by half. However, the lambs did not exhibit any clinical sign of sodium deficiency. The advantages of the developed method to collect saliva are discussed.

BPC 157's effect on healing

The 15 amino acid agent BPC 157, showing a wide range of organoprotective action in different experimental models, was used in our experiments in order to establish its influence on different elements connected with the healing process. Elements thought to be of greatest importance in the process of healing are formation of granulation tissue, angiogenesis and production of collagen. In our work we tested the influence of BPC 157 on: granulation tissue and collagen formation, on angiogenesis as well as on tensile strength development, using three experimental rat models: 1) skin incisional wounds; 2) colon-colon anastomoses; and 3) angiogenesis model with synthetic sponge implantation. The specimens were histologically assessed for collagen, reticulin and blood vessels using scoring and morphometry. In all experiments significant differences between BPC 157-treated animals and controls were found, showing a strong, promoting involvement of BPC in the healing process. It is worth noting that these effects were achieved by different routes of application, including intragastric and local, making BPC 157 a potentially useful therapeutic agent.

Removal of technetium-99 from contaminated groundwater with sorbents and reductive materials

Pertechnetate oxyanion (TcO 4 −), which is highly soluble in water and readily mobile in the environment, can be immobilized through an ion exchange /adsorption process and chemical reduction followed by adsorption and/or precipitation. Previous studies have focused on the separation and removal of 99TcO 4 − from high-level waste streams; however, little information is available for 99TcO 4 − removal from only slightly contaminated groundwater. This paper describes treatment of 99TcO 4 −-contaminated groundwater with both batch and column flowthrough experiments. Synthetic resins and sponges, and zero-valence iron filings were used to evaluate their capacities and the rates of 99TcO 4 − removal. The toxicity characteristic leaching procedure (TCLP) was applied to evaluate the leachability of 99Tc adsorbed or co-precipitated on iron. Results suggest that both iron and synthetic resins remove 99TcO 4 − from groundwater and that at a high flow rate (with residence time of less than 1 min), 99TcO 4 − removal capacity is greater for iron filings than for the synthetic resins on a volume basis. Additionally, the rate of 99TcO 4 − sorption on the sponge is slow (approximately 3 days), and the capacity is relatively low. No appreciable amount of 99Tc can be leached out from the spent iron filings by the TCLP test. Overall, zero-valence iron filings provide fast reaction and high removal capacity for 99TcO 4 − in groundwater. The high removal efficiency, low cost, and the small waste production of zero-valence iron are attractive for remediation of 99TcO 4 −-contaminated groundwater.

Hepatocyte Transplantation in the Dalmatian Dog Model of Hyperuricosuria

Hepatocyte transplantation shows promise as a therapy to support liver function. We have previously shown that hepatocytes can be transplanted into prevascularized synthetic polymers in rat and pig models. This study was designed to assess the possibility of correction of a liver metabolic defect in a dog model. The Dalmatian dog is known to have an inborn error of metabolism in the hepatocyte that causes a decrease in the degradation of uric acid into allantoin. This leads to a rise in uric acid levels in blood and urine. Four male Dalmatian dogs 18-28 kg in weight were studied as recipients of normal hepatocytes. Poly vinyl alcohol sponges measuring 250 cm(2) x 5 mm were first implanted between the leaves of the mesentery and the omentum to form prevascularized implantation beds, and an end-to-side portacaval shunt to induce hepatotrophic stimulation was made. After 7 days 1.5 x 10(10) normal hepatocytes obtained from donor beagles receiving cyclosporine immunosuppression were implanted into the prevascularized sponges. Excretion of uric acid in urine decreased from 136.3 +/- 18.1 to 44.1 +/- 20.4 micromol/kg/day (p < 0.05) in these animals at 2 weeks, and continued for 6 weeks. Uric acid levels in serum did not change significantly from 26.77 +/- 10.30 to 39.65 +/- 9.09 micromol/liter (mean +/- SD) 4 weeks after transplantation. Control Dalmatians, which were transplanted with Dalmatian hepatocytes, remained at baseline. Creatinine clearance was unchanged. We conclude that hepatocyte transplantation is possible in this Dalmatian dog model of hyperuricosuria and that urinary excretion of uric acid can be decreased by beagle hepatocyte transplantation delivered in prevascularized synthetic polymer sponges using portacaval shunts as hepatotrophic stimulation.

Noise inhibiting arrangements for room air conditioners

Synthetic sponge or other resilient material is joined to the top of a room air-conditioner to absorb the physical impact of rain and dripping water to inhibit the creation of the noise that would otherwise occur. Additionally, a buffer formed with angular surfaces, to absorb and deflect the full impact of rain and dripping water to inhibit the creation of noise that would otherwise occur.

Pseudomonas aeruginosa folliculitis due to non-O:11 serogroups: acquisition through use of contaminated synthetic sponges.

We describe the features of 13 cases of Pseudomonas aeruginosa folliculitis (eight of which occurred sporadically and five of which resulted from two family outbreaks) that developed subsequent to the use of commercial synthetic sponges for bathing. On the basis of O serogrouping and pyocin typing and subtyping, the strains recovered from the skin lesions were found to be identical to those isolated from household shower water and sponges. P. aeruginosa folliculitis is commonly caused by the serogroup O:11; The serogroups described in this study are rare causative agents of this type of skin infection. We believe that this is the first report of P. aeruginosa folliculitis due to serogroups O:3 and O:16.

Differential regulation of collagen gene expression in granulation tissue and nonrepair connective tissues in vitamin C‐deficient guinea pigs

Poor wound healing during vitamin C deficiency is thought to be due to decreased hydroxylation of proline residues in collagen. In non-repair connective tissues of guinea pigs, however, procollagen gene expression is not decreased until weight loss occurs during the third and fourth weeks of scurvy (phase II) with only a moderate decrease in proline hydroxylation. Decreased procollagen gene expression is related to the induction of insulin-like growth factor binding proteins 1 and 2 that inhibit insulin-like growth factor-I action. We examined wound healing and granulation tissue formation during phase I of vitamin C deficiency. Synthetic sponges were implanted on day 7 of vitamin C deficiency and analyzed at 6 and 10 days after surgery, when there was no weight loss or induction of insulin-like growth factor binding proteins. Healing of incisions was almost complete at 10 days after surgery in normal controls but not in scorbutic animals. The area around the incision and implant exhibited excessive angiogenesis and hemorrhaging of vessels in the scorbutic animals at 6 and 10 days after surgery. At 10 days after surgery, collagen synthesis in the implants of scorbutic guinea pigs was 36% lower than control values, with a normal extent of proline hydroxylation. Concentrations of messenger RNAs for types I and III procollagens were slightly increased by scurvy at 6 days after surgery but were decreased by 26% and 40%, respectively, at 10 days. Fibronectin mRNA levels were unaffected by scurvy at both time points. Our results suggest that poor wound healing in phase I of scurvy may be related to defective interstitial procollagen gene expression and defective blood vessel formation, but it does not involve inhibition of proline hydroxylation or induction of insulin-like growth factor binding proteins. mRNA for insulin-like growth factor-II, transforming growth factor-beta(1), and transforming growth factor-beta(2) were significantly expressed in implants, but their patterns of expression did not correlate with changes in procollagen gene expression.

Attraction of Maladera matrida (Coleoptera: Scarabaeidae) to Eugenol and Other Lures

Attraction of the scarab beetle Maladera matrida Argaman to lures was evaluated in peanut fields in the northwestern Negev Desert in Israel. Japanese beetle traps (Attack, Ringer, Minneapolis, MN) were baited with eugenol, 2-phenethyl propionate (PEP), geraniol, lavender oil, or Japonilure alone and in combination with two parts eugenol. Eugenol was the best attractant for both sexes. Males were not attracted to Japonilure. The attraction of eugenol did not improve by combining it With any of the other lures. In testing the attractant, of various dispensers, results from the synthetic sponge (of the Attack trap) loaded with :3 g eugenol were not significantly different from those from a pair of rubber septa loaded with only 500 mg eugenol. In the hot and dry Negev region, reduction in attractancy of baits was 40, 70, and 90% after 3, 7, and 14 d, respectively. When the insecticide methamidophos (Tamaron, at 20 ppm) was mixed with an equal amount of eugenol, its repellency overrode the attraction of the lure.

Efficacy of sterilization of endodontic files after autoclaving in a synthetic sponge.

A common way of sterilizing endodontic files for clinical use is to insert them into synthetic sponges. The files are sterilized in the sponge, and the sponge is then used on the patient tray for ease of file retrieval. The ability to sterilize the files in a sponge has been questioned. The purpose of the present investigation was to evaluate the sterility of files and spore strips following autoclaving in a sponge. Commercial spore strips and contaminated endodontic files were inserted into sponges, sealed in sterilization pouches and autoclaved. The spore strips and the files were removed from the sponge and cultured for growth of microorganisms. Results show that no microbes were cultured from spore strips or contaminated files after autoclaving them in the sponges sealed in autoclave pouches. These results indicate that the insertion of files into the sponges used in this study does not obstruct the autoclaving process.

Application of Merocel ® NASAL PACKINGS for Management of Hemorrhage from the Nose and Nasal Airway after Le Fort I Osteotomy

Nasal airway obstruction due to postoperative swelling of the nasal mucosa may frequently occur after Le Fort I osteotomy. Additionally, as in persistent hemorrhage from the nose, it should become more difficult or impossible to maintain a patient's nasal air passage.Recently, we used Merocel ® NASAL PACKINGS on 23 patients who underwent Le Fort I osteotomy. This device is an intranasal pack made of biocompatible synthetic surgical sponge called Merocel, designed to compress the nasal mucosa adequately, and able to maintain the nasal airway with the tube in the center of the pack. The nasal pack was applied to bilateral nasal cavities for three days immediately after extubation.We have found this nasal pack to be useful not only for controlling hemorrhage from the nose, but also maintaining the nasal air passage in postoperative care of the patients who undergo Le Fort I osteotomy.

The impact of debris on the Florida manatee

The endangered Florida manatee ingests debris while feeding. From 1978 through 1986, 439 salvaged manatees were examined. Debris was in the gastrointestinal tract of 63 (14.4%) and four died as a direct result of debris ingestion. Monofilament fishing line was the most common debris found (N=49). Plastic bags, string, twine, rope, fish hooks, wire, paper, cellophane, synthetic sponges, rubber bands, and stockings also were recovered. Entanglement in lines and nets killed 11 manatees from 1974 through 1985. Numerous free-ranging manatees have missing or scarred flippers from entanglements, or debris still encircling one or both flippers. We recommend local cleanups, education of the public, and fishing restrictions in high use areas to significantly reduce harm to manatees.

Influence of sponges on invertebrate recruitment: A field test of allelopathy

We manipulated live sponges in Belize, Central America, Big Pine Key, Florida (USA), and Indian River lagoon, Florida (USA) in summer/autumn, 1988. At each location, live sponges of three species were placed within 0.5 cm of ceramic tiles. Tiles with synthetic sponges positioned in the same manner and tiles with no sponges served as controls. Of 26 recruiting species analyzed, only one (Sponge sp. 6 — Indian River) was inhibited by living sponges. Four species (Perophora regina — Belize;Aiptasia pallida — Big Pine Key; andCrassostrea virginica andAscidia nigra — Indian River) recruited in greater numbers in the presence of sponges, suggesting that some larvae may be attracted rather than repelled by sponge allelochemicals. Allelopathic effects were less important than small-scale flow effects and patchy larval supply in determining recruitment patterns on surfaces adjacent to sponges.