pH‐sensitive alginate/soy protein microspheres as drug transporter

Abstract

The complex microspheres based on alginate (AL) and soy protein isolate (SPI) were prepared by solution blending and then Ca 2þ crosslinking, and their function as drug carrier was explored as well. The effects of composition on the structures of microspheres were studied, and the XRD results proved the miscibility between components. Meanwhile, FTIR results suggested that such miscibility was driven by strong hydrogen bonding. Especially, the complex microsphere with equal content of AL and SPI had the best miscibility by morphological analysis, shown as a smooth and uniform surface of SEM images. The controlled release function of the complex microspheres was verified using theophylline as a drug model, that is, the swelling and drug release were affected by pH conditions and showed obvious differences under given pH of stomach, intestine, and colon. Moreover, the intestine and colon may be optimal site for prompt release of drugs. Except for the attribution of AL component to pH sensitivity, the complex microspheres also inherited the bioactivity of SPI component, which may lower irritants of drug to the tissues in body.

Effect of polysaccharide nanocrystals on structure, properties, and drug release kinetics of alginate-based microspheres

“…Good miscibility in a blend is usually driven by intermolecular hydrogen bonding among the components [5]. FT-IR spectra of pure sodium alginate powder (SAP), CN, CHW and SN are represented in Fig.…”

“…In addition, due to the mild gelation process within the matrix and the high biocompatibility, alginate is well suited to form the matrix for the microencapsulation of various drugs. In previous works, we have explored pH-sensitive alginate/soy protein [5], alginate/carbon nanotube nanocomposite microspheres [6], and alginate-based magnetic microspheres [7] as drug transporters, which showed obvious differences in swelling and drug release. Because of the limited mechanical stability, durability, and high-diffusion rates resulting from the high porosity [8] (which results in low encapsulation efficiency and limited control over the kinetics of drug release) the practical applications of alginate as a drug delivery system are hindered.…”

Alginate microsphere filled with carbon nanotube as drug carrier

“…Herein, the composition [24], cross-linking density [25] and porous structure [26] become the main factors to affect the swelling process of microsphere and the diffusion of encapsulated substances, especially for the therapeutic macromolecules of protein [27] and peptide [28] as well as cells [29]. Currently, the pH sensitivity of AL-based microspheres has been used to elevate the stability of drug [30], to improve gastrointestinal tolerance [31], to realize sustained release after oral administration [32], and to targetedly release drug in intestine and colon [33].…”

Ecomaterials Based on Food Proteins and Polysaccharides

“…5 Ca 2+ -crosslinked complex microspheres can be prepared by injecting 3 wt% SPI and 3 wt% alginate solutions to 10 wt% CaCl 2 solution. 101 Although both components are crystallizable, the complex microspheres are amorphous due to the hydrogen bonding induced miscibility. The swelling and the controlled release of theophylline show obvious differences under given pH of stomach, intestine, and colon.…”