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.