Multifunctional hybrid 3D network based on hyaluronic acid and a copolymer containing pendant spiroacetal moieties.

The elasticity, soft consistency and similarity to the human body are important characteristics of the gels. Such similarities allow the hydrogels to be biocompatible and, as a consequence, they are very attractive to be applied as biomaterials. This study presents a new strategy for developing a biohybrid complex based on a natural/synthetic polymer conjugate as gel type structure enriched with quercetin, which can be a relevant biomaterial for its antimicrobial properties. There are evidenced the preparation possibilities for the natural/synthetic structure as complex gel based on hyaluronic acid conjugated with poly(itaconic anhydride­co­3,9­divinyl­2,4,8,10­tetraoxaspiro[5.5] undecane) copolymer decorated with quercetin. The effects of the composition on various properties were assessed. The chemical composition of bioconjugate gels was confirmed by FTIR spectroscopy. It was established that the new gel structures have enhanced swelling capacity and a typical gel-like behavior. The investigations evidenced the gels responsiveness to stimuli and their high elasticity. The new structures were tested as drug delivery systems. The in vitro release shows the dependence of the mechanism of release on the composition of the gels, evidencing a transport behavior which varies from the Fickian to super case II. In vivo investigations demonstrated a good biocompatibility after systemic administration in mice.

The protective effects of zinc in experimental gentamicin induced acute renal failure in rats.

This study investigates the effects of zinc in acute kidney injury induced by gentamicin (Ge). We used Wistar male rats distributed in 4 groups of 12 animals each, treated intraperitoneally as follows: Group I (Control) treated with distilled water; Group II (Ge) with experimental induced acute renal failure with Ge; Group III (Ge + Zn) administration of ZnCl2 in animals with experimental induced renal failure with Ge, Group IV (Zn) treated with ZnCl2 as positive control. We measured serum levels of urea, creatinine, total antioxidant status, superoxide dismutase, glutathione peroxidase and urinary proteins before the nephrotoxicity induction (baseline) and 3, 7 and 10 days after Ge administration. The renal histopathological analysis was also done. The results showed an increase of urea and creatinine values in Ge + Zn group after 7 days compared to baseline, but less accentuated than those in Ge group. Zn supplementation was associated with an increase of the total antioxidant status in Ge + Zn group compared to Ge group (P < 0.01). It was also revealed a significant reduction of proteinuria in Ge + Zn group compared to Ge group (P < 0.001). The histopathological investigation highlighted the tubular necrosis affecting more than 90% of proximal tubules in Ge group. In Ge + Zn group it was observed a milder degree of tubular necrosis (influencing less than 25% of proximal tubules), a moderate inflammation and the presence of tubular regeneration. In conclusion, Zn administration proved a to have a protective role in experimental gentamicin-induced acute renal failure.

The effect of pregabalin - codeine combination on partial sciatic nerve ligation - induced peripheral mononeuropathy in rats.

The present study investigates the effects of pregabalin (PGB) and codeine (COD) combination on neuropathic hyperalgesia in an animal model of peripheral nerve injury represented by partial sciatic nerve ligation. Hot plate and analgesimeter tests were performed to evaluate the influence of PGB, COD and their combination on thermal and mechanical hyperalgesia in the hind paw with partial sciatic nerve ligation. Reactivity was evaluated by measuring the latency to withdrawal of the operated hind paw from the noxious heat and pressure stimulation. Nociceptive thresholds were evaluated before (baseline) and in the 1(st), 3(rd), 5(th) and 7(th) day after surgical procedure. The investigation demonstrates that the treatment with PGB attenuated partial sciatic nerve ligation development of thermal and mechanical hyperalgesia in rats operated hind paw. The oral administration, during 14 consecutive days of PGB-COD combination significantly reduced the degree of both thermal and mechanical hyperalgesia in the hind paw with partial sciatic nerve ligation. These results suggest that the association of PGB with COD exerted ameliorative effect on partial sciatic nerve ligation-induced neuropathic pain in rats.

In vivo biocompatibility evaluation of some Bidens tripartita extracts in rats.

UNLABELLED: Adaptogens represent a class of herbs frequently used as a unique and natural alternative medicine and herbal remedy for treating the many forms of stress and different other pathological conditions. Bidens tripartite, a flowering plant from the genus Bidens, family Compositae, subfamily Asteroideae was widely used in traditional medicine for its antiseptic, anti-inflammatory, antioxidant, astringent, diuretic, febrifuge, narcotic and sedative effects. Phytochemical analysis of this plant has revealed the presence of flavonoids, xanthophylls, volatile oil, acetylene and polyacetylene, sterols, aurones, chalcones, caffeine and tannins. AIM: The in vivo biocompatibility evaluation of two extracts from Bidens tripartita plant in rats. MATERIAL AND METHODS: The vegetable product used for the study was obtained after maceration and extraction in alcohol. Flower powder was dissolved in absolute chloroform, re-extracted and filtered. After a complete dryness the product was extracted by the addition of ethanol then evaporated. The chemical composition of the extracts was determined. The administered dose of Bidens tripartita retained was 1/20 of lethal dose 50 (LD50). The experiment was carried out on white male Wistar rats (200-250g) divided into 3 groups of 7 animals each treated intraperitoneally as follows: Group I (Control): distilled water 0.1ml/10g weight; Group II (coded BT-alcoholic): 200mg/kbw alcoholic Bidens tripartita extract; Group III (coded BT-aqueous): 250mg/kbw aqueous Bidens tripartita extract. The biocompatibility properties of alcoholic and aqueous extracts from Bidens tritartita were studied by assessing their effects on blood count and serum biochemical tests. The following immune parameters: phagocytic capacity of peripheral neutrophils (NBT test) and serum complement activity were also evaluated. The data were presented as +/- SD and significance was tested by SPSS for Windows version 13.0 and ANOVA method. Experimental protocol was implemented according to the recommendations of the University Committee for Research and Ethical Issues and guidelines of IASP Committee for Research and Ethical Issue. RESULTS: Laboratory analysis did not show significant differences on leucocyte formula (GOT, GPT and LDH) or immune parameters (phagocytic capacity of peripheral neutrophils and serum complement activity) between alcoholic and aqueous B. tripartita extracts and distilled water, elements suggesting a good in vivo biocompatibility. CONCLUSIONS: In our experimental conditions, the alcoholic extract and aqueous extract from B. tripartita determined similar immune responses as distilled water following intraperitoneal administration in rats, indicative of good in vivo biocompatibility.

Experimental researches on acute toxicity of a Bidens tripartita extract in mice - preliminary investigations.

UNLABELLED: Plants take up an important place in traditional medicine and scientific research confirmed properties about their use as alternative therapy. Bidens tripartita, commonly known as Three-lobe Beggarticks, Three-part Beggarticks, Trifid Bur-marigold, is a flowering plant in the genus Bidens, family Compositae, subfamily Asteroideae. Evaluation of the chemical composition of this plant has revealed the presence of flavonoids, xanthophylls, volatile oil, acetylene and polyacetylene, sterols, aurones, chalcones, caffeine and tannins. AIM: Theoretical data investigation regarding Bidens tripartita plant and experimental researches on acute toxicity of an original extract in mice. MATERIAL AND METHODS: The vegetal product of Bidens tripartita used for study was obtained by maceration and extraction in alcohol, and its chemical composition was determined. Acute toxicity of the alcoholic extract of Bidens tripartita was assessed by median lethal dose (LD50) calculation, using a limit dose test of up- and- down procedure at a limit dose of 2000mg/kbw after intraperitoneal administration in mice. RESULTS: In the alcoholic extract of Bidens tripartita different active principles were identified: tannins, anthracene derivatives, triterpenes, coumarins, antocyanosides. The toxicity of plant product was evaluated by different characteristic signs for the mouse which can be retained as toxicity elements of the extract. Using the intraperitoneal route, the animals showed dose-dependent signs of toxicity, ranging from lack of appetite, depression, immobility and respiratory distress to death. Single-dose intraperitoneal LD50 value of the alcoholic Bidens tripartita extract in mice was 4038 mg/kg. No macroscopic changes were seen in the organs of mice that died following extract administration. Histopathological lesions were not found in all examined organs. CONCLUSIONS: The obtained LD50 value classifies the study plant extract as slightly toxic according to Hodge and Sterner toxicity scale. We determined the low toxic dose at a rate of 4038 mg of body weight for the alcoholic extract of this medicinal plant. These results suggest that the alcoholic extract of Bidens tripartita is relatively safe toxicologically when administered intraperitoneally, and this product could be used with some degree of safety to continue the investigation for in vivo biocompatibility evaluation.