Chitosan/PAMAM/Hydroxyapatite Engineered Drug Release Hydrogels with Tunable Rheological Properties

Abstract

In this paper, a new formulation of biodegradable and bioresorbable chitosan-based hydrogel for controlled drug release was investigated. A chitosan–dendrimer–hydroxyapatite hydrogel, obtained by covalently grafting chitosan powder with an hyperbranched PAMAM dendrimer followed by in-situ precipitation of hydroxyapatite and gelification, was synthesized and characterized by FTIR, NMR, TGA, XRD and rheological studies. The hydrogels have been also doped with an anti-inflammatory drug (ketoprofen) in order to investigate their drug release properties. Chemical and chemical-physical characterizations confirmed the successful covalent functionalization of chitosan with PAMAM and the synthesis of nanostructured hydroxyapatite. The developed hydrogel made it possible to obtain an innovative system with tunable rheological and drug-releasing properties relative to the well-known formulation containing chitosan and hydroxyapatite powder. The developed hydrogel showed different rheological and drug-releasing properties of chitosan matrix mixed with hydroxyapatite as a function of dendrimer molecular weight; therefore, the chitosan–dendrimer–hydroxyapatite hydrogel can couple the well-known osteoconductive properties of hydroxyapatite with the drug-release behavior and good processability of chitosan–dendrimer hydrogels, opening new approaches in the field of tissue engineering based on biopolymeric scaffolds.

Bioactive Coatings Based on Hydroxyapatite, Kanamycin, and Growth Factor for Biofilm Modulation

“…Chemical co-precipitation represents a facile method to synthesize tunable HAp-based biomaterials, starting from calcium and phosphorous precursors and conveniently adjusting various reaction parameters (temperature range, pH value, nature, and type of templating agent) [ 85 , 86 ]. Moreover, this versatile approach is suitable for extending the bioactivity and biofunctionality of HAp by doping with various inorganic ions [ 87 , 88 ] and by obtaining apatite composites [ 89 , 90 ].…”

Nanoindentation for Monitoring the Time-Variant Mechanical Strength of Drug-Loaded Collagen Hydrogel Regulated by Hydroxyapatite Nanoparticles

“…On the other hand, the BMP-2 release rate was relatively slow in the case of HAP/Col hydrogel (200/3.8). This is because the degree of hydration and the subsequent degradation of collagen fiber are retarded by HAPs, delaying degradation and slowing the DR kinetics. , It is to be noted that a steep change of relative Δ E occurred for the HAP/Col hydrogel (200/3.8) because the HAP detachment from the hydrogel induces its porous structure, which changes the indentation behavior. , In contrast, in the case of the HAP/Col hydrogel (100/3.8), the porous structure of the hydrogel was less affected by HAP detachment compared to that of the HAP/Col hydrogel (200/3.8), as shown in Figure c. These results indicated that adding an appropriate amount of HAPs into hydrogels plays a crucial role in determining their degradation rate and DR profiles.…”

Design and Preparation of New Multifunctional Hydrogels Based on Chitosan/Acrylic Polymers for Drug Delivery and Wound Dressing Applications

“…It is known that the drug release from hydrogels is governed by several phenomena: diffusion, erosion, network relaxation, all in various proportions, depending on the polymer nature, network stability and parameters, morphology, hydrophilicity, the nature of the drug and its interaction with the matrix, the release medium etc., [ 37 , 38 , 39 , 40 ]. In order to study the drug release kinetics and mechanism, the drug release data were fitted into four models, using the following equations [ 21 , 41 , 42 , 43 ]: where Q t is the amount of drug released at time t, Q 0 is the original drug concentration in the material (40 mg), n is the release exponent and K is the release rate constant.…”