CMC and dynamic properties of poly(VA-b-St) copolymer micelles for drug delivery

Abstract

The polymeric micelles from amphiphilic block copolymer poly(vinyl alcohol-b-styrene) (poly(VA-b-St)) with different syndiotacticity of poly(vinyl alcohol) (PVA) block were prepared by dialysis against water. Critical micelle concentration (CMC) and dynamic properties of poly(VA-b-St) copolymeric micelles were investigated by fluorescence techniques. From the fluorescence emission spectrum measurements using pyrene as a fluorescence probe, the observed CMC value was in the range of 0.125-4.47 mg/L. The CMC value increased with decreasing the weight ratio of PS to PVA block and with increasing the syndiotacticity of PVA block. The rate of pyrene release was very slow for block copolymers containing PVA block with higher syndiotacticity, which indicates that their micelles have increased kinetic stability.

Docetaxel-loaded PEO–PPO–PCL/TPGS mixed micelles for overcoming multidrug resistance and enhancing antitumor efficacy

“…The critical micelle concentration (CMC) was determined by the fluorescence probe technique using pyrene as a fluorescence probe. 25 Aliquots of pyrene solution (30 Â 10 À6 M in acetone, 0.1 mL) were added to 10 mL flask and the acetone was allowed to evaporate to form a thin film. Then a series of stock micelles solution ranging from 0.2 to 30 mg L À1 were added into the flasks and the final concentration of pyrene was 6 Â 10 À7 M in the solution.…”

Micellization behavior of mixtures of amphiphilic promazine hydrochloride and cationic aniline hydrochloride in aqueous and electrolyte solutions

“…Amphiphilic molecules such as surfactants, drugs, hydrotropes, and polymers self-associate in aqueous solution to form micelles or related structures above a certain concentration known as critical micelle concentration (CMC) [1][2][3][4][5][6][7]. These micelles are of widespread use in pharmaceutical applications besides food, detergency, cosmetic industries and enhanced oil recovery and range of applications [8].…”

Analysis of Immediate Stress Mechanisms upon Injection of Polymeric Micelles and Related Colloidal Drug Carriers: Implications on Drug Targeting

“…25 Specific interactions between hydrophobic blocks increased association tendency as studied with mixed micelles composed of PEGylated poly-Dlactic acid (PEG-PDLA) and PEGylated poly-L-lactic acid (PEG-PLLA). 26 Other groups made similar observations and based the increased stability on an increased number of hydrogen bonds in the core forming blocks, 27,28 π−πstacking, 29 hydrophobic interactions, 30 ionic interactions in the core, 31 and core cross-linking. 32,33 Typically CAC values of block copolymers are between 1 and 5 mg/L.…”

“…Specific interactions between hydrophobic blocks increased association tendency as studied with mixed micelles composed of PEGylated poly- d -lactic acid (PEG-PDLA) and PEGylated poly- l -lactic acid (PEG-PLLA) . Other groups made similar observations and based the increased stability on an increased number of hydrogen bonds in the core forming blocks, , π–π-stacking, hydrophobic interactions, ionic interactions in the core, and core cross-linking. , Typically CAC values of block copolymers are between 1 and 5 mg/L . Consequently, maintenance of polymer blood concentrations above the CAC level requires a minimum polymer dose between 6 and 30 mg for an average adult (6 L blood volume assuming immediate complete distribution).…”