Hybrid Materials from Intermolecular Associations between Cationic Lipid and Polymers

Abstract

Intermolecular associations between a cationic lipid and two model polymers were evaluated from preparation and characterization of hybrid thin films cast on silicon wafers. The novel materials were prepared by spin-coating of a chloroformic solution of lipid and polymer on silicon wafer. Polymers tested for miscibility with the cationic lipid dioctadecyldimethylammonium bromide (DODAB) were polystyrene (PS) and poly(methyl methacrylate) (PMMA). The films thus obtained were characterized by ellipsometry, wettability, optical and atomic force microscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and activity against Escherichia coli. Whereas intermolecular ion-dipole interactions were available for the PMMA-DODAB interacting pair producing smooth PMMA-DODAB films, the absence of such interactions for PS-DODAB films caused lipid segregation, poor film stability (detachment from the silicon wafer) and large rugosity. In addition, the well-established but still remarkable antimicrobial DODAB properties were transferred to the novel hybrid PMMA/DODAB coating, which is demonstrated to be highly effective against E. coli.

Antimicrobial Biomimetics

“…Antimicrobial films are required for packaging of food products, since microbial contaminations are responsible for enormous losses in food safety, conservation and shelf life (Cha & Chinnan, 2004;Dutta et al, 2009). Much effort has been devoted to the design of antimicrobial materials in form of particles, coatings or surfaces able to prevent surface contamination and/or erradicate the biofilm consortia (Tiller et al, 2001;Francolini et al, 2004;Furno et al, 2004;Zivanovic et al, 2007;Pereira et al, 2008;Ye et al, 2008;Caro et al, 2009;Avila-Sosa et al, 2010). The first combinations of dental cements and resins with antibiotic drugs were described in the fifties (Colton & Ehrlich, 1953) whereas resorbable or soluble polymeric carriers which could deliver active drugs directly at the site of infection started to be described in the late seventies (Kopecek, 1977;Arai et al, 2010;Campoccia et al, 2010;Feng et al, 2010;Noel et al, 2010).…”

“…The first combinations of dental cements and resins with antibiotic drugs were described in the fifties (Colton & Ehrlich, 1953) whereas resorbable or soluble polymeric carriers which could deliver active drugs directly at the site of infection started to be described in the late seventies (Kopecek, 1977;Arai et al, 2010;Campoccia et al, 2010;Feng et al, 2010;Noel et al, 2010). Control, eradication or inhibition of biofilms and surface-related contaminations included development of novel materials, ranging from synthetic (Park et al, 1998;Hirota et al, 2005;Jampala et al, 2008;Pereira et al, 2008;Bryaskova et al, 2010) to natural and biodegradable compounds (Zhang et al, 1994;Cha & Chinnan, 2004;Pranoto et al, 2005;Maizura et al, 2007;Noel et al, 2010). Local antibiotic delivery systems have been proposed as alternative therapies to typical prophylactic antibiotic dosing (Frank et al, 2005).…”

“…Four deposition steps produced a tetralayered film with sucessive layers: (polycation/ polyanion/ ponericin G1/ polyanion) n , where n represents the number of deposited tetralayer repeats (Shukla et al, 2010). Another approach to produce antimicrobial films and coatings is the spin-coating technique (Pereira et al, 2008;Jausovec et al, 2008), which is based on the solubilization of polymer and antimicrobial compound in a volatile solvent, e.g. chloroform, followed by spin-coating of the solution on the surface of a glass slide or silicon wafer.…”

Partículas e filmes híbridos de polímeros e compostos de amônio quaternário com atividade antimicrobiana

“…A quarta geração dos antimicrobianos quaternários inclui diversos sais de mono-e dialquil dimetilamônio e polímeros de amônio quaternário, tais como os ionenos, que são polieletrólitos catiônicos com átomos de nitrogênio na cauda da cadeia polimérica (PETROCCI et al, 1979). As propriedades antimicrobiana, antifúngica e tumoricida dos ionenos indicam que os polímeros são mais ativos do que seus monômeros correspondentes, devido à melhor adsorção do polímero à superfície da célula bacteriana e à membrana citoplasmática, geralmente levando ao subseqüente rompimento da sua integridade (IKEDA & TAZUKE, 1983 (TÁPIAS et al, 1994;SICCHIEROLLI et al, 1995;KANAZAWA et al, 1995;RUSSELL & CHOPRA, 1996;MARTINS et al, 1997;CARMONA-RIBEIRO et al, 1997;CAMPANHÃ et al, 1999;CAMPANHÃ et al, 2001;VIEIRA et al, 2003;PACHECO et al, 2004 (MARINI et al, 2007;PEREIRA et al, 2008).…”

“…Conforme já foi descrito na literatura, um trabalho anterior do grupo da professora Ana Maria Carmona-Ribeiro (PEREIRA et al, 2008) A presente invenção trata de partículas com propriedades antimicrobianas, apresentando um composto anfifílico ou lipídico com grupamento amônio quaternário e dois polieletrólitos, sendo um aniônico e um catiônico, este último também contendo grupamento amônio quaternário. A concentração do composto de caráter anfifílico variou de 0,01 a 1,0 mM, sendo preferencialmente, 0,1 ou 0,5 mM.…”