In this thesis work the attention was focused on research, very current and fascinating, related to the antibacterial activity of fatty acids and polymers, two classes of organic compounds also present in nature and widely used in the pharmaceutical, food and industrial fields . In particular, as regards fatty acids, numerous works have been collected to testify to their antimicrobial activity. For example, lauric acid (C10) has been shown to have the power to mitigate arenavirus activity in a dose dependent manner. From a study aimed at correlating the length of the chain of fatty acids and their bactericidal activity against gram positive and gram negative bacteria, it emerged that lauric acid is saturated fatty acid with greater inhibitory activity against gram positive organisms. The bactericidal activity of the lipids present in milk was also studied, from which it emerged that capric acid and lauric acid, unlike long-chain fatty acids, are active against Escherichia coli, Salmonella enteritidis, Campylobacter jejuni, Listeria monocytogenes and Clostridium perfringens, therefore, could improve the resistance to intestinal pathogens at the level of the gastrointestinal system. The effects of fatty acids on the pathogens present on the surface of the skin such as Staphylococcus aureus and Staphylococcus epidermidis, which respectively cause rough skin and atopic dermatitis, have been evaluated. It emerged that palmitoleic fatty acid has the potential to be used as a detergent in the treatment of dermatitis as it has a selective activity against Staphylococcus aureus.The physical-chemical properties of fatty acids such as capric, lauric and myristic acid and their binary mixtures and mixtures of oleic acid / stearic acid and oleic acid / behenic acid were evaluated to assess their solid-liquid behavior and stability at physiological temperature. The use of polymers in the medical industry is increasingly developed and current, therefore the intrinsic antimicrobial activity of some polymers has been studied, a feature that could lead to the solution of many problems related to infections that develop especially in hospitals. For these materials, the methods of microbial inhibition and the possible changes to be implemented were assessed in order to achieve an antimicrobial activity even to those who do not have it naturally or to enhance the activity of those who have an intrinsic one. One of these strategies could be the polymer-fatty acid coupling with antibacterial activity. The first attempts were made at our university by functionalizing polydimethylsiloxane with short chain acids such as capric and lauric. The polymer - antibiotic combinations were also evaluated as in the case of levofloxacin used to functionalize the PDMS, which allows a sustained antimicrobial action greater than only the active ingredient. Systems made with the three polymer components - fatty acid - antibiotic are under construction as regards basic research and could constitute an interesting development in the pharmaceutical and medical field.
In questo lavoro di tesi l’attenzione è stata focalizzata sulla ricerca, molto attuale e affascinante, relativa all’attività antibatterica degli acidi grassi e dei polimeri, due classi di composti organici presenti anche in natura e diffusamente impiegate in campo farmaceutico, alimentare e industriale. In particolare, per quanto riguarda gli acidi grassi, si sono raccolti numerosi lavori a testimonianza della loro attività antimicrobica. Ad esempio, l’acido laurico (C10) ha dimostrato avere il potere di attenuare l'attività di arenavirus in modo dose dipendente. Da uno studio volto a correlare la lunghezza della catena degli acidi grassi e la loro attività battericida nei confronti di batteri gram positivi e gram negativi, è emerso che l'acido laurico è l’acido grasso saturo con maggiore attività inibitoria contro organismi gram positivi. E’ stata studiata anche l'attività battericida dei lipidi presenti nel latte da cui è emerso che l'acido caprico e l’acido laurico a differenza di acidi grassi a lunga catene risultano attivi contro Escherichia coli, Salmonella enteritidis, Campylobacter jejuni, Listeria monocytogenes e Clostridium perfringens, pertanto potrebbero migliorare la resistenza ai patogeni intestinali a livello dell'apparato gastrointestinale .Si sono valutati gli effetti degli acidi grassi sui patogeni presenti sulla superficie della pelle come Staphylococcus aureus e Staphylococcus epidermidis i quali provocano rispettivamente pelle ruvida e dermatite atopica. Ne è emerso che l'acido grasso palmitoleico avrebbe il potenziale per essere utilizzato come detergente nella cura delle dermatiti in quanto presenta un’attività selettiva nei confronti di Staphylococcus aureus. Sono state valutate le proprietà chimico fisiche di acidi grassi quali acido caprico, laurico e miristico e loro miscele binarie e di miscele di acido oleico / acido stearico e acido oleico / acido beenico per valutarne il comportamento solido-liquido e la stabilità alla temperatura fisiologica. L’utilizzo dei polimeri nell'industria medicale è sempre più sviluppata e attuale, pertanto è stata studiata l'attività antimicrobica intrinseca di alcuni polimeri, caratteristica che potrebbe portare alla soluzione di molti problemi relativi alle infezioni che si sviluppano soprattutto negli ospedali. Per questi materiali sono state valutate le modalità di inibizione microbica e le modifiche possibili da attuare in modo da conseguire una attività antimicrobica anche a quelli che non la possiedono naturalmente o per potenziare l'attività di quelli che ne hanno una intrinseca. Una di queste strategie potrebbe essere proprio l’accoppiamento polimero – acido grasso con attività antibatterica. I primi tentativi sono stati fatti presso la nostra università funzionalizzando il polidimetilsilossano con acidi a catena corta quali il caprico e il laurico. Sono anche state valutate le combinazioni polimero - antibiotico come nel caso della levofloxacina usata per funzionalizzare il PDMS, che ne permette un’azione antimicrobica sostenuta maggiore rispetto al solo il principio attivo. Sistemi realizzati con le tre componenti polimero – acido grasso –antibiotico sono in fase di realizzazione per quanto riguarda la ricerca di base e potrebbero costituire un interessante sviluppo in campo farmaceutico e medico.
Attività antibatterica di sistemi termosensibili a base di polimeri e acidi grassi
TEDESCO, CLAUDIO
2019/2020
Abstract
In this thesis work the attention was focused on research, very current and fascinating, related to the antibacterial activity of fatty acids and polymers, two classes of organic compounds also present in nature and widely used in the pharmaceutical, food and industrial fields . In particular, as regards fatty acids, numerous works have been collected to testify to their antimicrobial activity. For example, lauric acid (C10) has been shown to have the power to mitigate arenavirus activity in a dose dependent manner. From a study aimed at correlating the length of the chain of fatty acids and their bactericidal activity against gram positive and gram negative bacteria, it emerged that lauric acid is saturated fatty acid with greater inhibitory activity against gram positive organisms. The bactericidal activity of the lipids present in milk was also studied, from which it emerged that capric acid and lauric acid, unlike long-chain fatty acids, are active against Escherichia coli, Salmonella enteritidis, Campylobacter jejuni, Listeria monocytogenes and Clostridium perfringens, therefore, could improve the resistance to intestinal pathogens at the level of the gastrointestinal system. The effects of fatty acids on the pathogens present on the surface of the skin such as Staphylococcus aureus and Staphylococcus epidermidis, which respectively cause rough skin and atopic dermatitis, have been evaluated. It emerged that palmitoleic fatty acid has the potential to be used as a detergent in the treatment of dermatitis as it has a selective activity against Staphylococcus aureus.The physical-chemical properties of fatty acids such as capric, lauric and myristic acid and their binary mixtures and mixtures of oleic acid / stearic acid and oleic acid / behenic acid were evaluated to assess their solid-liquid behavior and stability at physiological temperature. The use of polymers in the medical industry is increasingly developed and current, therefore the intrinsic antimicrobial activity of some polymers has been studied, a feature that could lead to the solution of many problems related to infections that develop especially in hospitals. For these materials, the methods of microbial inhibition and the possible changes to be implemented were assessed in order to achieve an antimicrobial activity even to those who do not have it naturally or to enhance the activity of those who have an intrinsic one. One of these strategies could be the polymer-fatty acid coupling with antibacterial activity. The first attempts were made at our university by functionalizing polydimethylsiloxane with short chain acids such as capric and lauric. The polymer - antibiotic combinations were also evaluated as in the case of levofloxacin used to functionalize the PDMS, which allows a sustained antimicrobial action greater than only the active ingredient. Systems made with the three polymer components - fatty acid - antibiotic are under construction as regards basic research and could constitute an interesting development in the pharmaceutical and medical field.È consentito all'utente scaricare e condividere i documenti disponibili a testo pieno in UNITESI UNIPV nel rispetto della licenza Creative Commons del tipo CC BY NC ND.
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https://hdl.handle.net/20.500.14239/11511