Novel caffeic acid grafted chitosan-sodium alginate microcapsules generated by microfluidic technique for the encapsulation of bioactive peptides from silkworm pupae

Microcapsules were prepared to develop an environmentally friendly drug carrier using chitosan and caffeic acid-grafted chitosan (CA-g-Ch) as carriers to efficiently encapsulate bioactive peptides from silkworm pupae by microfluidics. The optimization of the preparation process resulted in the optimal solution: 0.3% CA-g-Ch, 3% sodium alginate, 0.6% CaCl2, and 40 mg/mL silkworm pupae peptides. The developed microcapsules were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). CA-g-Ch-sodium alginate microcapsules could be used to deliver silkworm pupae bioactive peptides. The encapsulation efficiency of CA-g-Ch-sodium alginate microcapsules was enhanced to 96.61 ± 1.95%, and the thermal stability and antioxidant properties of the microcapsules were improved. In gastrointestinal digestion, CA-g-Ch-sodium alginate microcapsules showed good acid resistance and intestinal release. Thus, CA-g-Ch-sodium alginate microcapsules are expected to become environmentally friendly encapsulation carriers for hydrophilic drug delivery.