Highly Enhanced Curcumin Delivery Applying Association Type Nanostructures of Block Copolymers, Cyclodextrins and Polycyclodextrins

Abstract

The limited bioavailability of the highly hydrophobic natural compound, curcumin with wide range of beneficial bioactivity is still a challenge. Self-association type systems of polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymers (Pluronic) were applied to enhance the aqueous solubility of curcumin. Comparison of four Pluronics (94, 105, 127,108) with different compositions led to the conclusion that solubilization capacity is maximum for Pluronic 105 with intermediate polarity (hydrophilic/lipophilic balance (HLB) = 15) possessing the optimum balance between capacity of hydrophobic core of the micelle and hydrophilic stabilizing shell of the associate. Curcumin concentration in aqueous solution was managed to increase 105 times up to 1–3 g/L applying Pluronic at 0.01 mol/L. Formation of a host–guest complex of cyclodextrin as another way of increasing the curcumin solubility was also tested. Comparing the(2-hydroxypropyl)-α, β and γ cyclodextrins (CD) with 6, 7 and 8 sugar units and their polymers (poly-α-CD, poly-β-CD, poly-γ-CD) the γ-CD with the largest cavity found to be the most effective in curcumin encapsulation approaching the g/L range of concentration. The polymer type of the CDs presented prolonged and pH dependent release of curcumin in the gastrointestinal (GI) system modelled by simulated liquids. This retarding effect of polyCD was also shown and can be used for tuning in the combined system of Pluronic micelle and polyCD where the curcumin release was slower than from the micelle.

Influence of the Hydrophobicity of Pluronic Micelles Encapsulating Curcumin on the Membrane Permeability and Enhancement of Photoinduced Antibacterial Activity

“…One of the main drawbacks of Curcumin is its low solubility in water (less than 20 µg/mL); thus, the solubilization in micellar dispersions proves to be a viable solution to increase the drug’s solubility in aqueous formulations. A significant increase in CURC’s solubility, up to 3 mg/mL was reported in the literature in Pluronics P105, P108, and F127 solutions at concentrations above 10 −2 M [ 35 ]. Unfortunately, these concentrations are usually cytotoxic for most normal animal cells.…”

Preformulation Studies and Bioavailability Enhancement of Curcumin with a ‘Two in One’ PEG-β-Cyclodextrin Polymer

“…Our concept was to test the water-soluble polyethylene glycol cross-linked β-CD polymer as a ‘two in one’ polymeric system, which offers a combination of β-CD and PEG properties. Curcumin was chosen as a model drug, which can be solubilized by cyclodextrins [ 39 ], cyclodextrin polymers [ 39 ] and PEG 400 [ 40 ].…”

Modeling the Properties of Curcumin Derivatives in Relation to the Architecture of the Siloxane Host Matrices

“…These uses are possible due to its bioactivity demonstrated as antioxidant, antiviral, antibacterial, and antifungal [ 1 , 2 , 3 ]. Depending on the field of use, curcumin studies have been directed on methods to increase solubility for biomedical applications [ 4 , 5 , 6 , 7 , 8 ] or aimed at improving light or temperature stability properties for unconventional applications, such as sensors [ 9 , 10 , 11 ], pH indicators [ 12 , 13 ], dyes for solar cells [ 14 , 15 , 16 , 17 ], (bio) active coatings [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. In this regard, the dye was used in its natural form, or it was chemically modified either on β-diketone or peripheral aromatic groups.…”

“…In this regard, the dye was used in its natural form, or it was chemically modified either on β-diketone or peripheral aromatic groups. The physical and chemical properties of these structures are influenced by the type of dye conditioning, such as micelles [ 8 , 27 ], nanoparticles [ 6 ], or composite materials [ 28 , 29 , 30 ]. The targeted field of application is very important in choosing the type of conditioning of curcumin derivatives [ 31 ].…”