Plant Macromolecules as Biomaterials for Wound Healing

Natural biomolecules are increasingly relevant for biomedical applications and tissue engineering for being able to produce an effect on chemical signals, organization of cells, and restitution of extracellular matrix in lesioned tissues. In this chapter, we will address the potential of plant macromolecules, in particular, carbohydrates and proteins such as hemicelluloses and lectins. While lectins are mostly carbohydrate-binding proteins, which can interact with cell surfaces to initiate anti-inflammatory pathways, as well as immunomodulatory functions, hemicelluloses are remarkably known by their ability to form viscous solutions even at low concentrations, which makes them an excellent candidate as vehicle to carry different sorts of biomolecules. Taking into account the complexity of the whole healing process, as an overlapping and coordinated cascade of events, most of the properties presented here by those materials may be of interest to the wound-care market

Peptidases from Latex of Carica candamarcensis Upregulate COX-2 and IL-1 mRNA Transcripts against Salmonella enterica ser. Typhimurium-Mediated Inflammation

The immunomodulatory properties of a mixture of cysteine peptidases (P1G10) obtained from the fruit lattice of Carica candamarcensis were investigated. P1G10 was obtained from fresh latex samples by chromatography in a Sephadex column and initially administered to Swiss mice (n=5; 1 or 10 mg/kg) via i.p. After 30 min, the mice were injected with carrageenan (0.5 mg/mouse) or heat-killed S. Typhimurium (107 CFU/mL; 100°C/30 min) into the peritoneal cavity. Afterwards, two animal groups were i.p. administered with P1G10 (n=6; 1, 5, or 10 mg/Kg) or PBS 24 hours prior to challenge with live S. Typhimurium (107 CFU/mL). P1G10 stimulated the proliferation of circulating neutrophils and lymphocytes, 6 h after injection of carrageenan or heat-killed bacteria, respectively. Furthermore, survival after infection was dose-dependent and reached 60% of the animal group. On the other hand, control mice died 1–3 days after infection. The examination of mRNA transcripts in liver cells 24 h after infection confirmed fold variation increases of 5.8 and 4.8 times on average for IL-1 and COX-2, respectively, in P1G10 pretreated mice but not for TNF-α, IL-10, γ-IFN and iNOS, for which the results were comparable to untreated animals. These data are discussed in light of previous reports

Zoonotic potential of multidrug-resistant extraintestinal pathogenic Escherichia coli obtained from healthy poultry carcasses in Salvador, Brazil

The zoonotic potential to cause human and/or animal infections among multidrug-resistant extraintestinal pathogenic Escherichia coli from avian origin was investigated. Twenty-seven extraintestinal pathogenic E. coli isolates containing the increased survival gene (iss) were obtained from the livers of healthy and diseased poultry carcasses at two slaughterhouses in Salvador, northeastern Brazil. The antimicrobial resistance-susceptibility profiles were conducted with antibiotics of avian and/or human use by the standardized disc-diffusion method. Antimicrobial resistance was higher for levofloxacin (51.8%), amoxicillin/clavulanic acid (70.4%), ampicillin (81.5%), cefalotin (88.8%), tetracycline (100%) and streptomycin (100%). The minimum inhibitory concentrations above the resistance breakpoints of doxycycline, neomycin, oxytetracycline and enrofloxacin reached, respectively, 88.0%, 100%, 75% and 91.7% of the isolates. Strains with high and low antimicrobial resistance were i.p. administered to Swiss mice, and histopathological examination was carried out seven days after infection. Resistance to goat and human serum complement was also evaluated. The results show that Swiss mice challenged with strain 2B (resistant to 11 antimicrobials) provoked a severe degeneration of hepatocytes besides lymphocytic infiltration in the liver, whereas the spleen showed areas of degeneration of the white and red pulp. Conversely, the spleen and liver of mice challenged with strain 4A (resistant to two antimicrobials) were morphologically preserved. In addition, complement resistance to goat and human serum was high for strain 2B and low for strain 4A. Our data show that multidrug resistance and pathogenesis can be correlated in extraintestinal pathogenic E. coli strains obtained from apparently healthy poultry carcasses, increasing the risk for human public healthy