A novel CHS/ALG bi-layer composite membrane with sustained antimicrobial efficacy used as wound dressing

A membrane composed of an alginate（ALG） layer and a chitosan（CHS） layer with sustained antimicrobial efficacy was prepared.Ciprofloxacin HC1（CIP） was incorporated into the ALG layer.Morphological feature of the composite membrane was analyzed by scanning electron microscopy（SEM）.Water uptake capacity,in vitro drug release,and in vitro antimicrobial activity were evaluated.The composite membrane exhibited perfect binding characteristic between the two layers.The water uptake capacity of all the membranes was above 800%.The CIP could release from the composite membranes for 48 h.The membrane could control the bacterial growth persistently.The results suggested that this CHS/ALG composite membrane incorporated with CIP had the potential for wound dressing application.

Direct and Residual Microbicidal Efficacy of Various Antiseptics against Multi-Drug Resistant Bacteria

Background: Infections in ICU’s patients are known to often originate from the colonization of wounds by the patient’s endogenous microbiota, and to eventually lead to secondary sepsis. Aim: to compare in vitro the direct and residual effects after different exposure times of 4% chlorhexidine, and of 0.1% and 0.04% polyhexanide (in gel and solution forms), on ATCC-microorganisms, and too, on bacterial strains obtained from ICU patients. Methods: We used wild multi-drug resistant strains recently obtained from the wounds of patients hospitalized at ICU and reference strains from the American Type Culture Collection (ATCC). Chlorhexidine 4% was studied as a reference solution. The direct and residual effects of the 0.1% and 0.04% polyhexanide, in gel and solution forms, were analyzed using cotton germ carriers. To evaluate the direct effect, we exposed the strains to the antiseptic. To assess the residual effect, the germ-carriers were impregnated with antiseptic and were allowed to dry before we contaminated them. We inoculated the germ carriers in a culture medium with an inhibitor of antiseptic effect to count the number of surviving microorganisms. Findings: 0.1% Polyhexanide solution proved a direct and residual efficacy after 24 hours equivalent to 4% chlorhexidine. Is very important to highlight that this great efficacy did not change according to whether they were ATCC or multidrug-resistant strains. Conclusions: 0.1% polyhexanide demonstrated a great direct and residual efficacy (like 4% chlorhexidine), against multi-drug resistant strains isolated from ICU’s patients. Moreover, due to its few cytotoxicity against keratinocytes and fibroblasts can be an optimal antiseptic for burns, wounds or ulcers.

Cultivation of Anabena variabilis,Synechococcus elongatus,Spirulina platensis for the production of C-Phycocyanin,C-Phycoerythrin and Thalassiosira,Skeletonema,Chaetoceros for fucoxanthin

The pigments are vital parts of photosynthetic machinery in algae and exhibit a myriad of applications as nutraceuticals,cosmetics,colorants,which find huge applications in many industires,including the paint industry and paper industry.The antimicrobial,antioxidative,anti-inflammatory,and anti-cancer potential of microalgal pigments contribute towards their varied industrial applications.In this study,pigments(Fucoxanthin,C-phycocyanin,and C-phycoerythrin),extracted from microalgae were investigated to check the antimicrobial efficacy using agar well diffusion and disc diffusion methods against pathogenic bacteria:Staphylococcus aureus and Escherichia coli.The fucoxanthin pigment isolated from diatom Thalassiosira sp.exhibited the highest antibacterial activity against Staphylococcus aureus(17±1.53 mm)and in contrast fucoxanthin pigment isolated from Chaetoceroes sp.exhibited the highest bactericidal activity against Escherichia coli(18±1).The pigment extract of Spirulina plantesis showed the highest antibacterial activity against E.coli(41±0.3)and S.elongatus also exhibited high antibacterial activity against E.coli(32±0.5)while Anabaena variabilis showed the highest antibacterial activity against Staphylococcus aureus(34±0.5).The potential of microalgal pigments is highly valuable and further extensive studies can elaborate the underlying mechanisms.