Preparation of Magnetic pH-Sensitive Film With Alginate Base for Colon Specific Drug Delivery

Development and characterization of starch‑sodium alginate-montmorillonite biodegradable antibacterial films

The biodegradable antibacterial composite film blended with starch and sodium alginate was developed by solution casting method, using montmorillonite as the fortifier and star anise oil as the bacteriostat. Infrared analysis showed that montmorillonite and star anise oil were successfully incorporated into starch and sodium alginate to form a stable composite film. The addition of 6 wt% montmorillonite could enhance several properties of the films, including barrier properties, optical properties, thermal stability and mechanical properties. Meanwhile, the incorporation of star anise oil made the composite films have antibacterial properties to resist E. coli. Packing cherry tomatoes with starch‑sodium alginate-montmorillonite-star anise oil composite film could reduce the weight loss rate and decay rate of fresh cherry tomatoes. Soil burial experiments showed that the composite films exhibited a continuous biodegradation process. The starch‑sodium alginate-montmorillonite-star anise oil films decomposed into little pieces and were completely mixed in the soil within 22 days, which offered an application foreground for the development of biodegradable food packaging film with bacteriostatic activity.

Magneto-Mechanically Triggered Thick Films for Drug Delivery Micropumps

Given the demanding use of controlled drug delivery systems, our attention was focused on developing a magnetic film that can be triggered in the presence of a magnetic field for both drug delivery and the actuating mechanism in micropump biomedical microelectromechanical systems (BioMEMS). Magnetic alginate films were fabricated in three steps: the co-precipitation of iron salts in an alkaline environment to obtain magnetite nanoparticles (Fe₃O₄), the mixing of the obtained nanoparticles with a sodium alginate solution containing glycerol as a plasticizer and folic acid as an active substance, and finally the casting of the final solution in a Petri dish followed by cross-linking with calcium chloride solution. Magnetite nanoparticles were incorporated in the alginate matrix because of the well-established biocompatibility of both materials, a property that would make the film convenient for implantable BioMEMS devices. The obtained film was analyzed in terms of its magnetic, structural, and morphological properties. To demonstrate the hypothesis that the magnetic field can be used to trigger drug release from the films, we studied the release profile in an aqueous medium (pH = 8) using a NdFeB magnet as a triggering factor.

Development of a composite film fabricated from carboxymethyl chitosan and magnetite nanoparticles for pH-responsive bioactive agent release

Development of a biocompatible film enabling stimuli-responsive bioactive agent delivery has a high practical value for food and pharmaceutical applications. In this study, we generate a composite film, using the solution casting approach, from carboxymethyl chitosan (CMC) and magnetite nanoparticles (MNPs). The structures and properties of CMC, MNPs, and the generated film are characterized by using various characterization techniques, including Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, x-ray diffraction spectroscopy, and scanning electron microscopy. With the use of doxorubicin (DOX) as a model agent, the percentage of cumulative release of DOX from the agent-loaded film is found to be increased from 55% to 62% when the pH of the surrounding medium changes from 7.4 to 5.0. Our film warrants further development and optimization as a carrier to mediate pH-responsive bioactive agent release.

Recent advances in celluloses and their hybrids for stimuli-responsive drug delivery

The limitations of existing drug delivery systems (DDS) such as non-specific bio-distribution and poor selectivity have led to the exploration of a variety of carrier platforms to facilitate highly desirable and efficient drug delivery. Stimuli-responsive DDS are one of the most versatile and innovative approach to steer the compounds to the intended sites by exploiting their responsiveness to a range of various triggers. Preparation of stimuli-responsive DDS using celluloses and their derivatives offer a remarkable advantage over conventional polymer materials. In this review, we highlight on state-of-art progress in developing cellulose/cellulose hybrid stimuli-responsive DDS, which covers the preparation techniques, physicochemical properties, basic principles and, mechanisms of stimuli effect on drug release from various types of cellulose based carriers, through recent innovative investigations. Attention has been paid to endogenous stimuli (pH, temperature, redox gradient and ionic-strength) responsive DDS and exogenous stimuli (light, magnetic field and electric field) responsive DDS, where the cellulose-based materials have been extensively employed. Furthermore, the current challenges and future prospects of these DDS are also discussed at the end.

Preparation of magnetic pH-sensitive microcapsules with an alginate base as colon specific drug delivery systems through an entirely green route

The aim of this work was to prepare pH-sensitive drug carriers for colon specific drug delivery through a completely green and environmentally friendly route (without using any organic solvents, hazardous chemicals and even a harsh procedure).