Fabrication, characterization, and physicochemical properties of curcumin incorporated new P. vulgaris polysaccharides bio-composite film; potent drug carrier, antibacterial, and antioxidant properties.

Abstract

This study reports the fabrication and comprehensive evaluation of bio-composite films derived from Phaseolus vulgaris starch and cellulose, incorporating curcumin via solvent casting method. Structural characterization using UV-Vis, FT-IR, and XRD confirmed curcumin encapsulation and revealed modifications in crystallinity, with ¹³C MAS NMR confirming the preservation of cellulose I and A-type starch polymorphs. SEM and AFM analyses displayed homogenous film morphology and enhanced polymer drug compatibility. Mechanical strength improved with curcumin content, increasing from 17.99 MPa (neat St) to 32.12 MPa for St/Ce/Cur - 13 % curcumin film. All the films exhibited uniform thicknesses. Porosity rose from 25.13 ± 0.12 % (neat St) to 39.2 ± 0.21 % (13 %), while WVTR increased from 679.5 ± 3.1 g/m^-2d^-1 to 1049.4 ± 3.1 g/m^-2d^-1. Water absorption increased from 52.6 ± 1.24 % to 90.4 ± 0.64 %, and contact angle values rose from 5.8° to 29.4°, indicating higher hydrophobicity. The St/Ce/Cur - 13 % film exhibited the highest drug loading (2.11 ± 0.02 %) and encapsulation efficiency (94.3 ± 0.081 %). Drug release studies (0-72 h in PBS) showed 96 % sustained and slow release for St/Ce/Cur - 13 %, best described by a first-order model (R² = 0.8914). DPPH assay results revealed strong antioxidant capacity with an IC₅₀ of 181.04 μg/mL for the St/Ce/Cur - 13 % film. Antibacterial tests indicated inhibition zones of 11 mm (S. aureus), 9 mm (B. subtilis), and 7 mm (E. coli) for the St/Ce/Cur - 13 % formulation. The results suggest P. vulgaris based polysaccharides as a sustainable matrix for drug delivery systems with wound healing potential.