Surface engineered mesoporous silica carriers for the controlled delivery of anticancer drug 5-fluorouracil: Computational approach for the drug-carrier interactions using density functional theory

Introduction: Drug delivery systems are the topmost priority to increase drug safety and efficacy. In this study, hybrid porous silicates SBA-15 and its derivatives SBA@N and SBA@3N were synthesized and loaded with an anticancer drug, 5-fluorouracil. The drug release was studied in a simulated physiological environment. Method: These materials were characterized for their textural and physio-chemical properties by scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), small-angle X-ray diffraction (SAX), and nitrogen adsorption/desorption techniques. The surface electrostatics of the materials was measured by zeta potential. Results: The drug loading efficiency of the prepared hybrid materials was about 10%. In vitro drug release profiles were obtained in simulated fluids. Slow drug release kinetics was observed for SBA@3N, which released 7.5% of the entrapped drug in simulated intestinal fluid (SIF, pH 7.2) and 33% in simulated body fluid (SBF, pH 7.2) for 72 h. The material SBA@N presented an initial burst release of 13% in simulated intestinal fluid and 32.6% in simulated gastric fluid (SGF, pH 1.2), while about 70% of the drug was released within the next 72 h. Density functional theory (DFT) calculations have also supported the slow drug release from the SBA@3N material. The release mechanism of the drug from the prepared carriers was studied by first-order, second-order, Korsmeyer-Peppas, Hixson-Crowell, and Higuchi kinetic models. The drug release from these carriers follows Fickian diffusion and zero-order kinetics in SGF and SBF, whereas first-order, non-Fickian diffusion, and case-II transport were observed in SIF. Discussion: Based on these findings, the proposed synthesized hybrid materials may be suggested as a potential drug delivery system for anti-cancer drugs such as 5-fluorouracil.

Effect of calcium sulphate nanorods on mechanical properties of chitosan-hydroxyethyl methacrylate (HEMA) copolymer nanocomposites

Copolymers of chitosan and hydroxyetheyl methacrylate (HEMA) were successfully synthesized using ceric ammonium nitrate (CAN) as an initiator, via in situ polymerization method, followed by efficacious preparation of their nanocomposites by incorporating calcium sulphate nanorods via solution blending process. Hydrophilicity studies confirmed that grafting of HEMA in the backbone of the hydrophobic chitosan chains induced the improvement in hydrophilicity of chitosan, while mechanical properties of the nanocomposites were also enhanced significantly up to 20%, due to availability of enlarged surface area and higher aspect ratio of CaSO₄ nanorods. This was supported by FE-SEM and XRD analysis in terms of proper distribution of nanofiller through the copolymer matrix and corresponding rise in percentage crystallanity respectively. Results obtained from biodegradation studies proved the efficiency of CaSO₄ nanofillers to improve biomechanical strength of chitosan nanocomposites, without affecting their normal degradation profile that renders the products to be applicable for biomedical applications.

Integration of polymers in the pore space of mesoporous nanocarriers for drug delivery

The construction of carrier-polymer–drug hybrids in confined nanopore space is reviewed for advancing related drug delivery systems.

Mesoporous organosilica hybrids with a tunable amphoteric framework for controlled drug delivery

The integrated nitrile groups in the pore walls of the DU-MSH-CN were converted into reactive –COOH or –NH₂groups, by an acid or base hydrolysis technique to achieve large amounts of either –COOH or –NH₂groups into the pore walls. Thein vitrodrug release and biocompatibility tests proved the organosilica hybrids suitable for drug carriers in cancer therapy.

Metal Organic Framework [Zn2(1,4-bdc)2(dabco)]n as Drug Delivery System

Porous metal organic framework (MOF) {Zn2(1,4-bdc)2(dabco)}n synthesized under solvothermal conditions. The MOF was used as the carrier matrices for drug delivery system. The ibuprofen as analgesic and anti-inflammatory drug with 0.6 nm molecule size as a model was entrapped into this new carrier with pores distribution of 1.85 nm. The ibuprofen loading efficiency was obtained by thermogravimetric analysis. The ibuprofen loading efficiency of 22% (w/w) was obtained for this MOF. The entrapped ibuprofen was released over several days by soaking the sample in the simulated body fluid (pH 7.4) at 37 °C. The ibuprofen concentrations were analyzed using UV-vis Spectrophotometer at a wavelength of 260 nm. The result of release reveals that this {Zn2(1,4-bdc)2(dabco)}n is suitable as drug delivery system.