An in vitro investigation into targeted paclitaxel delivery nanomaterials based on chitosan-Pluronic P123-biotin copolymer for inhibiting human breast cancer cells

Surfactant-rescued gelation: Stabilizing P123-chitosan hydrogels in blood-isotonic aqueous solutions for controlled drug delivery

The loss of gelation in Chitosan-Pluronic composite hydrogels under physiological saline conditions restricts their potential for drug delivery applications. To this effect, we present a dynamic and composite hydrogel system based on Pluronic P123 and chitosan, which restores gelation upon the addition of sodium dodecyl sulfate (SDS), even in the presence of NaCl at blood-isotonic concentrations. The entry of SDS induces electrostatic interactions and hydrophobic associations, enabling robust gel formation under physiological conditions. The gelation behavior can be desirably modified by varying chitosan concentration and temperature, allowing tunable mechanical properties suitable for drug delivery applications. Rheological analysis confirmed enhanced mechanical stability in saline environments, while FTIR spectroscopy elucidated molecular interactions within the hydrogel. Quinine sulfate release studies showed sustained drug release without burst effects. Kinetic modeling indicated a predominantly non-Fickian transport mechanism, governed by both diffusion and polymer relaxation. This surfactant-rescued gelation strategy stabilizes chitosan-based hydrogels in physiological conditions, making them promising candidates for controlled drug delivery.

Polyethylene glycol hexadecyl ether modified heparin for paclitaxel nano-delivery system

A paclitaxel (PTX) nano-delivery system using modified heparin and polyethylene glycol hexadecyl ether (Brij 58) was developed in this study. Brij 58 was conjugated to the heparin backbone via the cystamine bridge, denoted as Hep-Brij 58, to facilitate self-assembly into stable nanoparticles in an aqueous environment. The self-assembled formation of Hep-Brij nanoparticles was demonstrated through dynamic light scattering and TEM, while the iodine method identified the critical concentration for the self-assembled process. PTX was incorporated into Hep-Brij nanoparticles through physical entrapment. The PTX-loaded Hep-Brij nanoparticles were then characterized according to particle size and size distribution, drug-loading content, and efficiency. Compared to Brij 58, Hep-Brij 58 was more effective in terms of the amount of PTX loaded. Hep-Brij 58/PTX was stable over two weeks of storage in distilled water.In vitrorelease of PTX from Hep-Brij 58 exhibited a controlled drug release effect following the diffusion kinetics. Furthermore, Hep-Brij 58 was non-toxic to primary healthy cells and cancer cells. Thein vitroanticancer test with Hela cells indicated remarkable anticancer activity of PTX-loaded Hep-Brij 58 nanoparticles compared to free PTX. In summary, Hep-Brij 58 nanoparticles hold considerable potential for use as a delivery system for managing PTX therapy.

Self-assembly of Pluronics: A critical review and relevant applications

Pluronics, alias poloxamers, are synthetic amphiphilic copolymers owning a triblock structure with a central hydrophobic poly(propylene oxide) (PPO) segment linked to two lateral hydrophilic poly(ethylene oxide) (PEO) chains. Commercially, Pluronics exist in numerous types according to the length of PPO and PEO chains, exhibiting different behavior and phase diagrams in solution. Concentrated aqueous solutions of Pluronics form thermoreversible gel-like systems. Properties, such as versatility, biocompatibility, nontoxicity, thermosensitivity and self-assembling behavior, make them extremely attractive for numerous applications. This review paper provides an overview on Pluronics, with a focus on their properties and phase behaviors, and on the effect of the presence of salts and additives. Different strategies to endow Pluronics with improved and extra properties, such as their chemical modification and mixed micelles, are briefly illustrated. Furthermore, a synopsis of useful experimental methodologies for understanding the flow properties of Pluronic-based systems is presented, providing a practical guide to their experimental characterization. Eventually, significant advances of Pluronic-based materials are briefly reviewed to elucidate their role in diverse applications, ranging from drug delivery and tissue engineering to bioprinting, cell cultures, personal care industry, conductive hydrogels, and electrocatalytic science. The current article is a critical review of Pluronic block copolymers, not intended as just inert materials but also as systems with functional properties able to revolutionize the paradigm of many technological fields.

Amphiphilic, lauric acid-coupled pluronic-based nano-micellar system for efficient glipizide delivery

Glipizide; an insulin secretagogue belonging to the sulfonylurea class, is a widely used antidiabetic drug for managing type 2 diabetes. However, the need for life-long administration and repeated doses poses challenges in maintaining optimal blood glucose levels. In this regard, orally active sustained-release nano-formulations can be a better alternative to traditional antidiabetic formulations. The present study explored an innovative approach by formulating orally active sustained-release nano-micelles using the amphiphilic lauric acid-conjugated-F127 (LAF127) block copolymer. LAF127 block copolymer was synthesized through esterification and thoroughly characterized before being employed to develop glipizide-loaded nano-micelles (GNM) via the thin-film hydration technique. The optimized formulation exhibited mean particle size of 341.40 ± 3.21 nm and depicted homogeneous particle size distribution with a polydispersity index (PDI) < 0.2. The formulation revealed a surface charge of -17.11 ± 6.23 mV. The in vitro release studies of glipizide from developed formulation depicted a sustained release profile. Drug loaded micelles exhibited a substantial reduction in blood glucose levels in diabetic rats for a duration of up to 24 h. Notably, neither the blank nano-micelles of LAF127 nor the drug loaded micelles manifested any indications of toxicity in healthy rats. This study provides an insight on suitability of synthesized LAF127 block copolymer for development of effective oral drug delivery systems for anti-diabetic activity without any significant adverse effects.

Potential from synergistic effect of quercetin and paclitaxel co-encapsulated in the targeted folic-gelatin-pluronic P123 nanogels for chemotherapy

Dual-drug delivery systems for anticancer therapy have recently attracted substantial attention due to their potency to overcome limitations of conventional anti-cancer drugs, tackle drug resistance problems, as well as improve the therapeutic efficacy. In this study, we introduced a novel nanogel based on folic acid-gelatin-pluronic P123 (FA-GP-P123) conjugate to simultaneously deliver quercetin (QU) and paclitaxel (PTX) to the targeted tumor. The results indicated that the drug loading capacity of FA-GP-P123 nanogels was significantly higher than that of P123 micelles. The kinetic release profiles of QU and PTX from the nanocarriers were governed by Fickian diffusion and swelling behavior, respectively. Notably, FA-GP-P123/QU/PTX dual-drug delivery system induced higher toxicity to MCF-7 and Hela cancer cells than either QU or PTX individual delivery system, and the non-targeted dug delivery system (GP-P123/QU/PTX), indicating the synergistic combination of dual drugs and FA positive targeting effect. Furthermore, FA-GP-P123 could effectively deliver QU and PTX to tumors in vivo after administration into MCF-7 tumor-bearing mice, which resulted in 94.20 ± 5.90 % of tumor volume reduced at day 14. Moreover, the side effects of the dual-drug delivery system were significantly reduced. Overall, we suggest FA-GP-P123 as potential nanocarrier for dual-drug delivery for targeted chemotherapy.

Effect of targeting ligand designation of self-assembly chitosan-poloxamer nanogels loaded Paclitacel on inhibiting MCF-7 cancer cell growth

In this study, we investigated two formulations of chitosan-Pluronic P123 with different folate ligand designation for targeted delivery of Paclitaxel (PTX), in which folic acid (FA) was directly conjugated to chitosan (FA-Cs-P123) or substituted onto P123 (Cs-P123-FA). The results showed that the FA content of Cs-P123-FA was determined at 0.71 wt/wt% which was significantly higher than that of FA-Cs-P123 (0.31 wt/wt%). Two copolymers were low critical gel concentrations (CGC). FA-Cs-P123 and Cs-P123-FA nanogels performed high PTX encapsulation efficiency reaching 95.57 ± 5.51 and 92.51 ± 6.68 wt/wt%, respectively. Transmission electron microscopy (TEM) and zeta potential analysis indicated that the PTX-loaded nanogels were spherically formed around 60 nm in diameter along with positive charge. Furthermore, the PTX release profile was slow and it was controlled by the pH of the medium. In particular, in vitro biocompatibility assays indicated that both FA-Cs-P123 and Cs-P123-FA exhibited good biological compatibility with a human foreskin fibroblast cell line and well uptake efficiency into MCF-7 cancer cells. Cs-P123-FA nanogel significantly enhanced the cytotoxicity of PTX in comparison with FA-Cs-P123. The result indicates that Cs-P123-FA nanogels with a higher decorated FA content perform a better targeting efficiency; therefore, they could have great potential application towards breast cancer treatment.