Dual-Responsive Alginate Hydrogel Constructed by Sulfhdryl Dendrimer as an Intelligent System for Drug Delivery

Intelligent stimulus-triggered release and high drug-loading capacity are crucial requirements for drug delivery systems in cancer treatment. Based on the excessive intracellular GSH expression and pH conditions in tumor cells, a novel glutathione (GSH) and pH dual-responsive hydrogel was designed and synthesized by conjugates of glutamic acid-cysteine dendrimer with alginate (Glu-Cys-SA) through click reaction, and then cross-linked with polyethylene glycol (PEG) through hydrogen bonds to form a 3D-net structure. The hydrogel, self-assembled by the inner disulfide bonds of the dendrimer, is designed to respond to the GSH heterogeneity in tumors, with a remarkably high drug loading capacity. The Dox-loaded Glu-Cys-SA hydrogel showed controlled drug release behavior, significantly with a release rate of over 76% in response to GSH. The cytotoxicity investigation indicated that the prepared DOX-loaded hydrogel exhibited comparable anti-tumor activity against HepG-2 cells with positive control. These biocompatible hydrogels are expected to be well-designed GSH and pH dual-sensitive conjugates or polymers for efficient anticancer drug delivery.

Advances in Anti-Tumor Nanomedicine based on Functional Metal Organic Frameworks beyond Drug Carriers

Nanoscale metal-organic frameworks (MOFs) have attracted widespread interest due to the unique properties including tunable porous structure, high drug loading capacity, structural diversity, and outstanding biocompatibility. MOFs have been extensively...

Improved Dissolution of Albendazole from High Drug Loaded Ternary Solid Dispersion: Formulation and Characterization

Bioavailability of a poorly water-soluble drug, e.g., widely used anthelmintic drug Albendazole (ABZ), is very low and thus, to obtain an optimized therapeutic efficacy, the aqueous solubility of such drugs needs to be enhanced. The objective of this study was to develop an effective high drug-loaded solid dispersion (SD) of ABZ with two biocompatible drug carriers, namely Soluplus® and Ludiflash® to improve its physicochemical characteristics. Equilibrium solubility study was performed to choose the optimum polymer ratio among the formulations and it showed up to 50-fold enhanced solubility compared to crystalline ABZ in water. X-Ray Powder Diffraction (XRPD) and Differential Scanning Calorimetry (DSC) studies of SD-ABZ showed reduced crystallinity of ABZ in the SD. The polymeric carriers, notably Soluplus®, are thought to play a key role in the reduction of crystallinity and molecular polydispersity of ABZ. The dissolution studies in water showed improved dissolution of SD-ABZ compared to crystalline ABZ, with a quick onset of drug release followed by gradual dissolution. However, due to high drug-loading and retention of crystalline ABZ in the sample, the dissolution behavior was not as expected, and may require further studies to optimize the SD-ABZ formulation. Dhaka Univ. J. Pharm. Sci. 20(2): 149-158, 2021 (December)

A Review on Nanoparticles: Preparation and Characterization of Nanoparticles

The development of innovative medication delivery systems has increased at an exponential rate in the last few years. Nanoparticles are particles with a size of between one and one hundred nanometers. Nanoparticles provide substantial benefits over conventional drug administration in terms of high bioavailability, high stability, high drug-carrying capacity, and other characteristics. This review concentrated mostly on the classification of nanoparticles, the technique of synthesis, the evaluation of nanoparticles, and the list of FDA-approved nanomedicines now available on the market.

Designing Highly Stable Poly(sarcosine)-based Telodendrimer Micelles with High Drug Content Exemplified with Fulvestrant

Polymeric micelles have been extensively used as nanocarriers for the delivery of chemotherapeutic agents aiming to improve their efficacy in cancer treatment. However, poor loading capacity, premature drug release, non-uniformity and reproducibility still remain the major challenges. To create a stable polymeric micelle with high drug loading, a telodendrimer micelle was developed as a nanocarrier for fulvestrant, as an example of a drug that has extremely poor water solubility (sub nanomolar range). Telodendrimers were prepared by synthesis of a hydrophilic linear poly(sarcosine) and growing a lysine dendron from the chain terminal amine by a divergent synthesis. At the periphery of the dendritic block, 4, 8, and 16 fulvestrant molecules were conjugated to the lysine dendron creating a hydrophobic block. Having drug as part of the carrier not only reduces the usage of the inert carrier materials but also prevent the drugs from leakage and premature release by diffusion. The self-assembled telodendrimer micelles demonstrated good colloidal stability (CMC < 2 µM) in buffer and were uniform in size. In addition, these telodendrimer micelles could solubilize additional fulvestrant yielding an excellent overall drug loading capacity of up to 77 wt.% total drug load (summation of conjugated and encapsulated). Importantly, the size of the micelles could be tuned between 25-150 nm by controlling (i) the ratio between hydrophilic and hydrophobic blocks and (ii) the amount of encapsulated fulvestrant. The versatility of these telodendrimer-based micelle systems to both conjugate and encapsulate drug with high efficiency and stability, in addition to possessing other tuneable properties makes it a promising drug delivery system for a range of active pharmaceutical ingredients and therapeutic targets.