Biodegradable dextran–polylactide hydrogel networks: Their swelling, morphology and the controlled release of indomethacin

Abstract

Biodegradable polymer hydrogel networks based on hydrophilic dextran derivative of allyl isocyanate (dex-AI) and hydrophobic poly (D,L) lactide diacrylate macromer (PDLLAM) were synthesized, and their swelling and morphological properties were studied. During a 2-day incubation, the higher the PDLLAM composition in the hydrogel, the slower the swelling as well as the lower the extent of swelling were. A 3D porous network structure was observed by scanning electron microscope. The rate of formation of this 3D porous network structure depended on the hydrophilicity of the components, their composition ratio, and the degradation time. The highly hydrophilic dex-AI component facilitated the formation of this 3D porous network structure at an earlier immersion period, while the degradability of the PDLLAM component would make this 3D porous network structure more open at a later immersion period. Indomethacin, a low molecular weight and moderately hydrophobic drug, was incorporated into the hydrogels for the release study in pH 7.4 phosphate buffer solution at 37 degrees C. The release kinetics suggested, as the PDLLAM composition increased, the indomethacin diffusion coefficient (D) and release half life time (t(1/2)) decreased, while the release index n increased. The controlled release mechanism was determined by the combination of three factors: the rate and degree of formation of swelling-induced 3D porous structure in the hydrogel, the hydrolytic degradation of PDLLAM components, and the hydrophobic interaction between PDLLAM and IDM.

Engineering Polysaccharide-Based Polymeric Micelles to Enhance Permeability of Cyclosporin A Across Caco-2 Cells

“…It possesses excellent biocompatibility and has been used in medicine as plasma substitute, due to its known innocuousness both locally and systemically (37). More recently, dextran-based gels and prodrugs have been investigated as carriers for a variety of bioactive agents (38)(39)(40)(41). Hydroxypropylcellulose is a common excipient in oral formulations, due to its excellent processability and disintegrant and bioadhesive properties.…”

Controlled Drug Delivery From Composites of Nanostructured Porous Silicon and Poly( L -Lactide)

“…These polymers and various copolymer compositions have shown considerable potential as effective drug carriers [41,42] and have been extensively studied for the controlled release of drugs due to their tunable degradation rates (from months to years), wide range of mechanical properties and biodegradability [40,[43][44][45][46][47][48][49]. Poly(l-lactide) (PLLA) is particularly advantageous since its degradation product, lactic acid, is well tolerated by the body [50][51][52][53]. The degradation properties of polyesters have been widely studied [54,55] and are known to be affected by polymer properties (i.e., molecular weight, chemistry, wettability and crystallinity) and also the properties of the release medium (i.e., pH, ionic strength and solvent) [56].…”

Biopolymer Thin Films Synthesized by Advanced Pulsed Laser Techniques

“…Magnetic composite thin films of Fe x O y nanoparticles and photo-cross-linked Dextran hydrogels are promising candidates for a broad field of applications from medicine to mechanical engineering [40]. Dextran-conjugated materials have been successfully investigated as controlled release delivery vehicles of indomethacin (a low molecular weight hydrophobic anti-inflammatory drug) [42], bovine serum albumin [43,44], lysozyme, and immunoglobulin G [41,44].…”

“…As a biodegradable and biocompatible biopolymer, it was investigated as a blood plasma replacement in the early 1940s [38]. Dextran could be functionalized with nanoparticles [18,39,40] or conjugated with different polymers [41][42][43][44] for various biomedical applications as described in Section 4.1.…”