scholarly journals EMULSIFICATION PARAMETERS STUDY ON MICELLES FORMATION FROM HYDROPHOBICALLY MODIFIED CHITOSAN

Author(s):  
Agnieszka Piegat ◽  
◽  
Agata Niemczyk ◽  
Agata Goszczyńska ◽  

A series of N,O-acylated chitosan derivatives were emulsified with different fatty acids. Hydrophobically modified chitosan derivatives were expected to exhibit self-assembly behaviour resulting in micelle formation. Several parameters of the oil-in-water emulsification process were investigated: mixing method, speed and duration, volume oil phase and addition of modifiers. Their influence on micellar Z-average diameter, size distribution and Zeta potential was analysed based on dynamic light scattering measurements. There were various relations between the hydrodynamic behaviour of chitosan derivatives, their chemical structure and the process parameters. Additionally, the obtained micelles could serve as active compound carriers because they encapsulated two model substances, namely ibuprofen and α-tocopherol.

2006 ◽  
Vol 63 (4) ◽  
pp. 493-499 ◽  
Author(s):  
Y WU ◽  
T SEO ◽  
T SASAKI ◽  
S IRIE ◽  
K SAKURAI

2019 ◽  
Vol 25 (14) ◽  
pp. 1616-1622 ◽  
Author(s):  
Gabriela Muniz Félix Araújo ◽  
Gabriela Muniz Félix Araújo ◽  
Alana Rafaela Albuquerque Barros ◽  
Alana Rafaela Albuquerque Barros ◽  
João Augusto Oshiro-Junior ◽  
...  

Leishmaniasis is one of the most neglected diseases in the world. Its most severe clinical form, called visceral, if left untreated, can be fatal. Conventional therapy is based on the use of pentavalent antimonials and includes amphotericin B (AmB) as a second-choice drug. The micellar formulation of AmB, although effective, is associated with acute and chronic toxicity. Commercially-available lipid formulations emerged to overcome such drawbacks, but their high cost limits their widespread use. Drug delivery systems such as nanoemulsions (NE) have proven ability to solubilize hydrophobic compounds, improve absorption and bioavailability, increase efficacy and reduce toxicity of encapsulated drugs. NE become even more attractive because they are inexpensive and easy to prepare. The aim of this work was to incorporate AmB in NE prepared by sonicating a mixture of surfactants, Kolliphor® HS15 (KHS15) and Brij® 52, and an oil, isopropyl myristate. NE exhibited neutral pH, conductivity values consistent with oil in water systems, spherical structures with negative Zeta potential value, monomodal size distribution and average diameter of drug-containing droplets ranging from 33 to 132 nm. AmB did not modify the thermal behavior of the system, likely due to its dispersion in the internal phase. Statistically similar antileishmanial activity of AmB-loaded NE to that of AmB micellar formulation suggests further exploring them in terms of toxicity and effectiveness against amastigotes, with the aim of offering an alternative to treat visceral leishmaniasis.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1884
Author(s):  
Mengfei Jin ◽  
Shangyong Li ◽  
Yanhong Wu ◽  
Dandan Li ◽  
Yantao Han

(1) Background: In the treatment of ulcerative colitis (UC), accurate delivery and release of anti-inflammatory drugs to the site of inflammation can reduce systemic side effects. (2) Methods: We took advantage of this goal to prepare resveratrol-loaded PLGA nanoparticles (RES-PCAC-NPs) by emulsification solvent volatilization. After layer-by-layer self-assembly technology, we deposited chitosan and alginate to form a three-layer polyelectrolyte film. (3) Results: It can transport nanoparticles through the gastric environment to target inflammation sites and slowly release drugs at a specific pH. The resulting RES-PCAC-NPs have an ideal average diameter (~255 nm), a narrow particle size distribution and a positively charged surface charge (~13.5 mV). The Fourier transform infrared spectroscopy showed that resveratrol was successfully encapsulated into PCAC nanoparticles, and the encapsulation efficiency reached 87.26%. In addition, fluorescence imaging showed that RES-PCAC-NPs with positive charges on the surface can effectively target and accumulate in the inflammation site while continuing to penetrate downward to promote mucosal healing. Importantly, oral RES-PCAC-NPs treatment in DSS-induced mice was superior to other results in significantly improved inflammatory markers of UC. (4) Conclusions: Our results strongly prove that RES-PCAC-NPs can target the inflamed colon for maximum efficacy, and this oral pharmaceutical formulation can represent a promising formulation in the treatment of UC.


Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 107
Author(s):  
Agnieszka Piegat ◽  
Anna Żywicka ◽  
Agata Niemczyk ◽  
Agata Goszczyńska

The antibacterial activity of N,O-acylated chitosan derivative with linoleic acid (CH_LA) was tested by disc and well diffusion, agar impregnation and microdilution methods against Staphylococcus aureus, Escherichia coli and Helicobacter pylori strains. Hydrophobically modified chitosan (HMC) was expected to exhibit enhanced antibacterial activity and specific mucin interactions. Although diffusion tests have not indicated the antibacterial potential of chitosan (CH) or CH_LA, the results of the microdilution method demonstrated that tested polymers significantly reduced the amount of living bacteria cells in different concentrations depending on the microorganism. Additionally, CH_LA was characterized by enhanced antibacterial activity compared to CH, which may suggest a different mechanism of interaction with S. aureus and H. pylori. Furthermore, the UV-VIS analysis revealed that the amphiphilic character of derivative led to strong CH_LA–mucin interactions. The study proved the high potential of CH_LA in antibacterial applications, especially for the gastrointestinal tract.


2021 ◽  
Vol 546 ◽  
pp. 149161
Author(s):  
Frantisek Ondreas ◽  
Marcela Dusankova ◽  
Jaroslav Sita ◽  
Martin Cepa ◽  
Jiri Stepan ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2846
Author(s):  
Seung Hyuk Im ◽  
Dam Hyeok Im ◽  
Su Jeong Park ◽  
Justin Jihong Chung ◽  
Youngmee Jung ◽  
...  

Polylactide (PLA) is among the most common biodegradable polymers, with applications in various fields, such as renewable and biomedical industries. PLA features poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) enantiomers, which form stereocomplex crystals through racemic blending. PLA emerged as a promising material owing to its sustainable, eco-friendly, and fully biodegradable properties. Nevertheless, PLA still has a low applicability for drug delivery as a carrier and scaffold. Stereocomplex PLA (sc-PLA) exhibits substantially improved mechanical and physical strength compared to the homopolymer, overcoming these limitations. Recently, numerous studies have reported the use of sc-PLA as a drug carrier through encapsulation of various drugs, proteins, and secondary molecules by various processes including micelle formation, self-assembly, emulsion, and inkjet printing. However, concerns such as low loading capacity, weak stability of hydrophilic contents, and non-sustainable release behavior remain. This review focuses on various strategies to overcome the current challenges of sc-PLA in drug delivery systems and biomedical applications in three critical fields, namely anti-cancer therapy, tissue engineering, and anti-microbial activity. Furthermore, the excellent potential of sc-PLA as a next-generation polymeric material is discussed.


2021 ◽  
Author(s):  
Hui Dong ◽  
Yifei Jiang ◽  
Xia Li ◽  
Wenjia Han ◽  
Qijun Ding ◽  
...  

Abstract The aims of this study were to study the performance changes of S-CNCs (spherical cellulose nanocrystals) modified by OSA (octenyl succinic anhydride) stabilized Pickering oil-in-water (O/W) emulsions. The Fourier transform infrared (FTIR) spectroscopy and contact angle change of the MS-CNCs (modified spherical cellulose nanocrystals) prove the successful modification of OSA and the improvement of hydrophobicity. The effect of a series of MS-CNCs concentration on the volume mean diameter, emulsion ratio, stability and micro-rheological characteristic viscosity of the emulsion was studied. The results show that the emulsifying ability of the S-CNCs have been greatly improved. In addition, at a concentration of 10g/l, the volume mean diameter reaches the nanometer level (0.95 µm), and the emulsion ratio reaches 100%, while still maintaining its unique ultra-low viscosity characteristics. Furthermore, the emulsion still exhibits high-strength resistance to ionic strength, but exhibits unique responsiveness to pH (pH≤5) at special stages.


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