Incorporation of Lamotrigine Drug in the PEO–PPO–PEO Triblock Copolymer (Pluronic F127) Micelles: Effect of Hydrophilic Polymers

Pluronic-phosphatidylcholine mixed polymeric nanomicellar formulation for curcumin drug bioavailability: Design, fabrication, characterization and in vitro bioinvestigations

Curcumin (CUR), obtained from turmeric, has biological advantages, but low aqueous solubility restricts its pharmaceutical applications. In the present work, a mixed polymeric nanomicellar formulation composed of bioactive Pluronic P123, Pluronic F68, and biocompatible phosphatidylcholine (PC) was designed and examined as the nanovehicles for overcoming the major barriers of poor bioavailability related to CUR. The CUR-incorporated P123/F68/PC mixed nanomicellar formulation (CUR-PFPC) was fabricated by the thin film technique and investigated in vitro. The fabrication of CUR-PFPC was optimized through D-optimal design. CUR-PFPC morphology, size distribution, zeta potential, drug encapsulating and incorporation efficiency, compatibility, and crystallinity were characterized using DLS, TEM, FTIR, XRD, and DSC analysis. Moreover, the cumulative drug release, antioxidant assays, and antimicrobial properties of formulations were also examined. The CUR-PFPC formulation exhibited a micellar size of 67.43 nm, a zeta potential of −15.1 mV, a PDI of 0.528, and a spherical shape. The mixed micellar formulation showed excellent compatibility and stability. The in vitro release profile of the CUR-PFPC reached over 60% in comparison to the 95% release of CUR, indicating a slow and sustained release. The DPPH assay showed that the CUR-PFPC had 96% antioxidant activity. Results show that the CUR-PFPC has powerful antibacterial and antifungal properties, which separates it from the free CUR. These findings suggest that the fabricated CUR-PFPC mixed polymeric nanomicellar formulation is thermodynamically and kinetically stable and may be considered a novel nanovehicle for hydrophobic antimicrobial drugs like CUR.

Graphical Abstract

[Formula: see text]

Tertiary Nanosystem Composed of Graphene Quantum Dots, Levofloxacin and Silver Nitrate for Microbiological Control

BACKGROUND

Infectious diseases have the highest mortality rate in the world and these numbers are associated with scarce and/or ineffective diagnosis and bacterial resistance. Currently, with the development of new pharmaceutical formulations, nanotechnology is gaining prominence.

METHODS

Nanomicelles were produced by ultrasonication. The particle size and shape were evaluated by scanning electron microscopy and confirmed by dynamic light scattering, also thermogravimetric analysis was performed to evaluate the thermal stability. Finally, antibacterial activity has been performed.

RESULTS

The results showed that a rod-shaped nanosystem, with 316.1 nm and PDI of 0.243 was formed. The nanosystem was efficient against Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis subsp. spizizenii with MIC inferior to 0.98 and a synergistic effect between silver graphene quantum dots and levofloxacin was observed.

CONCLUSION

The nanosystem produced may rise as a promising agent against the bacterial threat, especially regarding bacterial resistance.

Mixed Poloxamer Nanomicelles for the Anticonvulsant Lamotrigine Drug: Solubility, Micellar Characterization, and In-Vitro Release Studies

Recently the applications of Poloxamers in drug development is promising as it facilitated the drug molecule for delivering to the correct place, at the correct time and in the correct amount. Poloxamers can form nanomicelles to encapsulate hydrophobic drugs in order to increase solubility, stability and facilitate delivery at target. In this context, the solubilization of anticonvulsant lamotrigine (LMN) drug in a chain of Poloxamers containing different polyethylene oxide and polypropylene oxide noieties were examined. The results showed better solubilization of LMN in Poloxamers contain low CMTs while poor with Poloxamers having high CMTs. Systematic investigation of two mixed Poloxamer nanomicelles (P407:P403 and P407:P105) for LMN bioavailability at body temperature (37 °C) were investigated. The solubility of LMN was enhanced in mixed P407:P403 nanomicelles with the amount of P403 and reduced in mixed P407:P105 nanomicelles with the amount of P105. LMN encapsulated mixed Poloxamer nanomicelles were found spherical in shape with ~25 nm D_h sizes. The In-Vitro release profiles of mixed Poloxamer nanomicelles demonstrated the biphasic model with initial burst release and then slowly release of LMN. Better biocompatibility of LMN in the mixed P407:P403 nanomicelles was confirmed with stability data. The results of this work were proven the mixed P407:P403 nanomicelles as efficient nanocarriers for LMN.

Reinforced macromolecular micelle-crosslinked hyaluronate gels induced by water/DMSO binary solvent

Introducing macromolecular micelles into a biocompatible hyaluronic acid (HA) hydrogel is a promising strategy to improve its mechanical properties for biomedical applications. However, it is still unclear whether the solvent nature has an influence on the structure and property of HA gels especially when they are used for those cases containing binary solvents because reversible hydrophobic association within micelles could be weakened or even dissociated by organic solvents. In this work, we demonstrated that a binary solvent consisting of water and low-toxic dimethyl sulfoxide (DMSO), a commonly used cryoprotectant agent in biomedicine, can enhance the mechanical properties of hydrophobic-associated methacrylated hyaluronate (MeHA) gels crosslinked by diacrylated PEO99-PPO65-PEO99 (F127DA) macromolecular micelles, namely FH gels. The resulting FH hydro/organo-gels showed a crystalline structure due to polymer/solvent interactions. The FH gels showed a low swelling degree and the maximum strength (10.12 MPa), modulus (106.8 kPa) and toughness (1540 J m-2) in DMSO with a volume fraction of around 0.6. Moreover, the FH gels displayed a rapid recoverability under cyclic loading-unloading stress particularly in the presence of DMSO within the network due to their dual-dynamic dissipation networks. Such novel hydrophobic associated polysaccharide gels with tunable mechanical properties in binary solvents would be attractive in a cryopreservation system for cell-based applications.

Coarse-Grained Molecular Dynamic and Experimental Studies on Self-Assembly Behavior of Nonionic F127/HS15 Mixed Micellar Systems

The self-assembly of a nonionic triblock copolymer (F127) and a nonionic surfactant (HS15) has been investigated due to favorable changes in properties in their mixtures. The effect of the mixing ratio on the self-assembly process and on the structural stability of the mixtures was studied by coarse-grained molecular dynamic simulation (CGMD) and experimental measurements (transmission electron microscopy, dynamic light scattering measurement, drug loading stability analysis, and fluorescence spectroscopy measurement). The CGMD provided the information on self-assembly behavior. The microstructure and micellar stability are affected by different proportions of F127/HS15. Pure HS15 molecules (system I) can rapidly form stable aggregates driven by strong hydrophobic force, including two steps: the formation of seed clusters and the fusion of them. At low F127 ratio (system II), the self-assembly process is dynamic unstable, and a volatile "coil/cluster-like" aggregate is formed under the single "binding" effect. As the ratio of added F127 increase, such as system III, stable "lotus-seedpod-like" aggregates form under the double effects of "binding plus wrapping". Its dynamic equilibrium can be achieved rapidly. The experimental results approved the assumption of "different mixing ratio with different structural stability" and even different loading stability of F127/HS15 systems for drugs with different log P, such as PUE and DTX, which means different loading area for them in the micellar systems at different mixing ratios because of less hydrophobic microdomains with the increase of F127 molecules.