RESUMO
The pursuit of efficient drug delivery systems has led to innovative approaches such as matrix and core-shell structures. This study explores these systems with a focus on enhancing the delivery and stability of curcumin, a bioactive compound with therapeutic potential. Matrix systems using zein protein were fabricated through coaxial airflow extrusion with a vibration generator, while core-shell systems were produced using concentric nozzles. Double-layer reservoir systems were also formed by coating chitosan-shelled structures with an alginate solution. Encapsulation of curcumin within each system was confirmed through FTIR and optical microscope analysis, followed by efficiency evaluation, which was measured approximately 86.5 ± 0.7 % for the matrix systems and 90 ± 0.8 % for the core-shell systems. Moreover, the particle sizes of matrix systems were measured in the range of 2000-2100 mµ and the particle sizes of single-layer and double-layer reservoir systems were in the ranges of 1600-1700 mµ and 1500-1700 mµ, respectively. The study investigated the stability of curcumin in these systems under various environmental conditions, including exposure to light, heat, pH variations, ions, and storage. Results demonstrated that the presence of multiple layers significantly enhanced the drug's stability. Afterwards, swelling and drug release profiles were assessed in simulated gastric, intestinal, and colon fluids. The swelling of the matrix, single-layer and double-layer reservoir systems after 29 h were 127.4 %, 146.9 % and 144 %, respectively. The matrix system showed 68.7 % drug release after 29 h, whereas single-layer chitosan-shelled and double-layer chitosan/alginate-shelled reservoir systems released 51.8 % and 45.6 % of the drug, respectively. The release mechanism was explored using zero-order, Korsmeyer-Peppas, and Kopcha kinetic models. Comparative analysis of the experimental results and model fittings indicated a deviation from Fickian diffusion, with erosion becoming more pronounced with each additional layer. In conclusion, the system with a zein core and double-layer chitosan/alginate shell displayed effective drug release regulation and enhanced stability of curcumin, making it a promising candidate for efficient drug delivery.
RESUMO
The novel pH-responsive polymer nanoparticles have been widely used for drug delivery and cancer therapy. The pH-sensitive nanoparticles include chemical structures that can accept or donate protons in response to an environmental pH change. Polybases which mostly contain alkaline groups such as amines and hydroxy, accept protons at low pH and are neutral at higher pH values. This study aimed to prepare pH-sensitive colloidal amphiphilic poly(vinyl alcohol-2-hydroxyethyl methacrylate) (PVA-PHEMA) copolymers in cancer therapy applications. For this purpose, poly(vinyl acetate-2-hydroxyethyl methacrylate) (PVAc-PHEMA) copolymer nanoparticles were synthesized in different polymerization medium fractions from water and methanol and different monomer feed concentration. Then acetate groups were hydrolyzed, and the PHEMA-PVA nanoparticles were synthesized. The nanoparticles were further characterized using dynamic light scattering, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis to identify the structural and morphological changes. The Methotrexate (MTX) was loaded into the nanoparticles, and drug release kinetics were evaluated. The results confirmed that PHEMA-PVA copolymeric nanoparticles could be favorably used in cancer therapy.