Adsorption and Release of 5-Fluorouracil (5FU) from Mesoporous Silica Nanoparticles

Intact Fibrillated 3D-Printed Cellulose Macrofibrils/CaCO3 for Controlled Drug Delivery

The tendency to use cellulose fibrils for direct ink writing (DIW) of three-dimensional (3D) printing has been growing extensively due to their advantageous mechanical properties. However, retaining cellulose in its fibrillated forms after the printing process has always been a challenge. In this study, cellulose macrofibrils (CMFs) from oil palm empty fruit bunch (OPEFB) fibers were partially dissolved for consistent viscosity needed for DIW 3D printing. The printed CMF structure obtained from optimized printing profiles (volumetric flow rate, Qv = 9.58 mm/s; print speed, v = 20 mm/s), exhibited excellent mechanical properties (tensile strength of 66 MPa, Young's modulus of 2.16 GPa, and elongation of 8.76%). The remarkable structural and morphological effects of the intact cellulose fibrils show a homogeneous distribution with synthesized precipitated calcium carbonate (CaCO3) nanoparticles. The shear-aligned CMF/CaCO3 printed composite exhibited a sustained therapeutic drug release profile that can reduce rapid release that has adverse effects on healthy cells. In comparison with the initial burst release of 5-fluorouracil (5-FU) by CaCO3, the controlled release of 5-fluorouracil can be varied (48 to 75%) with the composition of CMF/CaCO3 allowing efficient release over time.

Clay nanoparticles as pharmaceutical carriers in drug delivery systems

INTRODUCTION

Clay minerals are a class of silicates with chemical inertness, colloid, and thixotropy, which have excellent physicochemical properties, good biocompatibility, low toxicity, and have high application potential in biomedical fields. These inorganic materials have been widely used in pharmaceutical excipients and active substances. In recent years, nanoclay mineral materials have been used as drug vehicles for the delivery of a variety of drugs based on their broad specific surface area, rich porosity, diverse morphology, good adsorption performance, and high ion exchange capacity.

AREAS COVERED

This review introduces the structures, properties, and applications of various common natural and synthetic nanoclay materials as drug carriers. Natural nanoclays have different morphologies including nanoplates, nanotubes, and nanofibers. Synthetic materials have controllable sizes and flexible structures, where mesoporous silica nanoparticles, laponite, and imogolite are typical ones. These inorganic nanoparticles are often linked to polymers to form multifunctional drug delivery systems for better pharmaceutical performance.

EXPERT OPINION

The clay nanomaterials have typical properties, including enhanced solubility of insoluble drugs, targeting therapeutic sites, controlled release, and stimulation of responsive drug delivery systems.

Construction and characterization of a temperature-responsive nanocarrier for imidacloprid based on mesoporous silica nanoparticles

Nanopesticides have great potential applications due to their stability enhancement, sustained release and target affinity. In this work, a temperature-responsive nanocarrier for imidacloprid (IMI) was constructed using mesoporous silica nanoparticles (MSNs) as the core and paraffin wax (PW) as the outer layer. IMI was loaded into MSNs by screening the drug/carrier mass ratios to obtain the optimized IMI/MSNs formulation with a high drug loading (27.47 %). IMI/MSNs were functionalized with octadecyltrimethoxysilane (C₁₈TMS) and further coated with a temperature-responsive trigger (PW) through hydrophobic interactions. Thus, a temperature-responsive nanocarrier for IMI (PW/IMI/MSNs) was constructed. Fourier transforms infrared (FT-IR), thermogravimetric analysis (TGA) and N₂ adsorption-desorption isotherm measurements confirmed the successful loading of IMI into MSNs and the coating of PW on the surface of the IMI/MSNs. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses indicated that PW/IMI/MSNs with diameters approximately 100 nm had an ordered hexagonal mesoporous structure with a surface coating of approximately 6 nm. In addition, an in vitro release experiment showed that PW/IMI/MSNs displayed a temperature-responsive sustained release property. Correspondingly, the bioactivity assay of the PW/IMI/MSNs showed that the insecticidal activity greatly increased with temperature. This formulation is expected to have potential applications in some high-temperature areas, such as Turpan in Xinjiang Province, for improving the utilization efficiency of IMI.

3D Printed Laminated CaCO3-Nanocellulose Films as Controlled-Release 5-Fluorouracil

Drug delivery constitutes the formulations, technologies, and systems for the transport of pharmaceutical compounds to specific areas in the body to exert safe therapeutic effects. The main criteria for selecting the correct medium for drug delivery are the quantity of the drug being carried and the amount of time required to release the drug. Hence, this research aimed to improve the aforementioned criteria by synthesizing a medium based on calcium carbonate-nanocellulose composite and evaluating its efficiency as a medium for drug delivery. Specifically, the efficiency was assessed in terms of the rates of uptake and release of 5-fluorouracil. Through the evaluation of the morphological and chemical properties of the synthesized composite, the established 3D printing profiles of nanocellulose and CaCO₃ took place following the layer-by-layer films. The 3D printed double laminated CaCO₃-nanocellulose managed to release the 5-fluorouracil as an effective single composition and in a time-controlled manner.