pH-responsive chitosan nanoparticles from a novel twin-chain anionic amphiphile for controlled and targeted delivery of vancomycin
摘要:
The design and synthesis of novel pH-responsive nanoantibiotics is an emerging research area to address the antibiotic resistance crisis. The purpose of this study was therefore to synthesize a new anionic gemini surfactant (AGS) that could result in the formulation of pH-responsive chitosan nanoparticles (CSNPs) to treat methicillin-resistant Staphylococcus aureus (MRSA) infections. The coupling of oleic acid with 2,2-dimethy1-5,5-bis(hydroxymethyl)-1,3-dioxane and subsequent deprotection followed by a reaction with succinic anhydride and sodium bicarbonate yielded AGS. Critical micelle concentration (CMC) was determined using conductometry and in vitro cytotoxicity was performed using a MTT assay. Vancomycin loaded CSNPs containing AGS (DL(-)CSSNPs) were prepared by ionotropic gelation of chitosan with pentasodium tripolyphosphate. CSNPs were characterized for size, polydispersity index (PDI), zeta potential (ZP), entrapment efficiency, surface morphology, in vitro drug release and in vitro antibacterial activity (at pH 6.5 and 7.4). Results from-the in vitro antibacterial activity were further supported by an in vivo study using a mice skin infection model. The CMC of AGS was found to be 1.3 mM/L and it was non-toxic. The DLISSNPs were spherical with size, PDI and ZP of 220.57 +/- 5.9 nm, 0.299 +/- 0.004 and 21.9 +/- 0.9 mV respectively. An increase in the vancomycin release from the DL(-)CSSNPs was observed at pH 6.5 compared to pH 7.4. The minimum inhibitory concentration values at pH 6.5 and 7.4 against MRSA were 7.81 and 62.5 mu g/ml respectively. In vivo antibacterial activity showed that the MRSA burden in mice treated with DL(-)CSSNPs was reduced by almost 8-fold compared to those treated with pure vancomycin. (C) 2017 Elsevier B.V. All rights reserved.
ESTERS FROM SOLID POLYOLS AND UNSATURATED CARBOXYLIC ACIDS
申请人:Daute Peter
公开号:US20130035271A1
公开(公告)日:2013-02-07
The present invention relates to a process for the preparation of an ester from a polyol which is solid at 25° C. and a carboxylic acid component which contains at least 50 wt. % of at least one mono- or polyunsaturated aliphatic carboxylic acid, based on the total weight of the carboxylic acid component, in a reactor under reduced pressure. The invention also provides a device, a process for the preparation of a thermoplastic composition comprising the ester prepared according to the invention, a process for the production of a shaped article comprising the ester according to the invention or the thermoplastic composition according to the invention, a process for the production of a packed product, a process for the production of an at least partly coated object, and uses of the esters according to the invention as an additive in various compositions.
The present invention relates to a process for the preparation of an ester in a reactor, a device, a process for the preparation of a thermoplastic composition comprising the ester prepared according to the invention, a process for the production of a shaped article comprising the ester according to the invention or the thermoplastic composition according to the invention, a process for the production of a packed product, a process for the production of an at least partly coated object, and uses of the esters according to the invention as an additive in various compositions.
Combinations of sunscreen agents with UV-A and UV-B filtering properties
申请人:3V SIGMA S.p.A
公开号:EP1027883A2
公开(公告)日:2000-08-16
Combinations of sunscreens comprising at least one specific anti UV-B filter with triazinoaniline structure and at least one specific anti UV-A filter selected from filters with benzoxazol substituted triazinoaniline structure and a long chain alkyl ester of a benzoxazolyl-aminophenyl-cyanoacrylic acid. Cosmetic and dermatological compositions containing them, optionally in combination with vitamins and/or other anti UV-A and anti UV-B filters.
Method for obtaining O/W cosmetic emulsions with high water resistance
申请人:3V SIGMA S.p.A
公开号:EP1977789A1
公开(公告)日:2008-10-08
This invention relates to a method for obtaining cationic O/W emulsions designed for skin care, which present high water resistance associated with excellent "skin feeling" characteristics, consisting of incorporating a polymer obtainable by homopolymerisation of a monomer A or B or copolymerisation of A and B, wherein A and B are dialkylaminoalkyl acrylate or dialkylaminoalkyl methacrylate or their quaternary ammonium salts. The invention also concerns the compositions obtainable by the method.
本发明涉及一种获得护肤用阳离子水包油型乳液的方法,该乳液具有高耐水性和优异的 "肤感 "特性,包括加入一种聚合物,该聚合物可通过单体 A 或 B 的均聚合或 A 和 B 的共聚合获得,其中 A 和 B 为丙烯酸二烷基氨基烷基酯或甲基丙烯酸二烷基氨基烷基酯或它们的季铵盐。本发明还涉及可通过该方法获得的组合物。