Sodium alginate (SA ) was combined with poly(N ‐isopropylacrylamide) (PNIPAAm ) to prepare thermosensitive hydrogels through semi‐interpenetrating polymer network (semi‐IPN ) and fully interpenetrating polymer network (full‐IPN ). The thermosensitive, swelling, mechanical, and thermal properties of pure PNIPAAm , SA /PNIPAAm semi‐IPN , and Ca‐alginate/PNIPAAm full‐IPN hydrogels were investigated. The formation of semi‐IPN and full‐IPN significantly improved the hydrogels’ swelling capability and mechanical properties without altering their thermosensitivity. 5‐Fluorouracil (5‐Fu) was selected as a model drug to study the release behaviors of the hydrogels. It was found that in vitro controlled drug release from semi‐IPN hydrogels showed an initial release burst, followed by a slower and sustained release, before reaching equilibrium. Full‐IPN hydrogels showed slow and sustained release during the whole process. Temperature and pH were found to affect the rate of drug release. Ca‐alginate/PNIPAAm full‐IPN hydrogels have potential application as drug delivery matrices in controlled drug release. 相似文献
In this study, biodegradable and antibacterial poly(azomethine‐urethane) (PAMU)‐ and chitosan (CS)‐based hydrogels have been prepared for controlled drug delivery applications. Structural and morphological characterizations of the hydrogels were performed via Fourier transform‐infrared and scanning electron microscopy analyses. Thermal stability, hydrophilicity, swelling, mechanical, biodegradation, protein absorption properties, and drug delivery application of PAMU‐ and CS‐based hydrogels were also investigated. The swelling performance of the hydrogels was studied in acidic, neutral, and alkaline media. Swelling results showed that the hydrogels have higher swelling capacity in acidic and alkaline media than neutral medium. Biodegradation experiments of the hydrogels were also studied via hydrolytic and enzymatic experiments. The drug release property of the hydrogel was carried out using 5‐fluoro uracil (5‐FU), and 5‐FU release capacity of the hydrogels was found in the range from 40.10% to 58.40% after 3 days. 相似文献
In this paper, 1,4-bi(phenylalanine-diglycol)-benzene (PDB) based Low-Molecular-Weight-Gelator (LMWG) hydrogels are modified using hydrophilic polysaccharide (sodium alginate). A set of techniques including Fourier transform infrared (FT-IR) spectroscopy, 1H Nuclear Magnetic Resonance (1H NMR), X-ray powder diffraction (XRD), Ultraviolet-Visible (UV-Vis), and circular dichroism (CD) had confirmed a β-turn arrangement of PDB gelators and a semi-interpenetrating network (semi-IPN), which was formed through hydrogen bonds between LMWG fibers and polysaccharide chains. The evaluation of physicochemical properties of hydrogels indicates that gelator-polysaccharide hybrid hydrogels possess better mechanical and water retention properties than LMWG hydrogels. The release study of dyes (model drug) from both LMWG and hybrid hydrogels was carried out. Compared with PDB based hydrogels, hybrid hydrogels show a selective and controllable release property for certain dyes. The results suggest LMWG-polysaccharide hybrid gels may find potential applications as promising drug delivery vehicles for drug molecules. 相似文献
In this paper, the properties of the complete degradation process of newly synthesized multi-block 2.0 G-polyamidoamine-double bond (PAMAM-DB) and resoluble poly (ethylene glycol) -co- poly (glycolic acid) -co- methacryloyl chloride (PEG-co-PGA-co-DB, 4KG5-DB) macromonomers were reported. Rectangular shaped samples were prepared by crosslinking the components using both chemical and photo initiators and exposure to UV light. The aims of the study were to examine the effects of the vitro degradation and drug delivery of the crosslinking group on the properties of photocrosslinked hydrogels. The experimental variable was PAMAM-DB: 4KG5-DB ratio. The effects of this variable on local PH, water uptake, mass loss, and drug release were explored. Polymers were characterized by 1H NMR, 13C NMR, FT-IR, and SEM. Our study revealed that polymers with 40%, 50%, 60% 4KG5-DB (mass fraction) showed more excellent mechanical properties, 40% also showed outstanding vitro degradation properties. In vitro drug release, however, 60% drug released mechanism seemed to approach the Fickian diffusion and possessed more excellent drug release properties compared with formulation 40% and 50%. In general, an increase ratio of 4KG5-DB led to a higher density of tree-like polymer which resulted in slower of degradation and drug release. Incorporation of 4KG5-DB into the polymer was critical for maintaining integrity and increasing hydrophilicity during degradation. These results obtained suggest that this system could be potential as a material for bone replacement and controlled delivery of drugs. 相似文献
The purpose of the study is to obtain multicomponent polyelectrolyte hydrogels with optimal synergistic properties by combining a modified starch with a synthetic one. Thus, new low‐cost and biocompatible semi‐interpenetrating polymer network (semi‐IPN) hydrogels of carboxymethyl starch and poly(2‐dimethylaminoethyl methacrylate) are prepared and investigated. The synthesized hydrogels are studied with respect to the specific characteristics of the gels: swelling kinetics, thermal analysis, viscoelastic characteristics, and their ability to be used as a matrix in drug delivery systems. Therefore, the semi‐IPN gels are loaded with ibuprofen, followed by additional tests to assess the in vitro drug release. The cytocompatibility of the hydrogels with respect to their composition is evaluated in vitro on fibroblast cell culture. The investigations confirm the obtainment of new semi‐IPN hydrogels with pH and temperature responsiveness, good mechanical strength, and potential for use as drug delivery systems or transdermal patches. 相似文献
Hydrogels with improved mechanical properties have been particularly attractive for their applications in the biomedical area including wound healing. For this purpose, a series of novel composite hydrogels based on silk fibroin (SF) and 2-(N,N-dimethylamino) ethyl methacrylate (DMAEMA) were fabricated. The swelling and mechanical tests indicated that an optimum design of hydrogel was essential to provide a high degree of water uptake, higher tensile strength and elongation at break values. Here, the S40D60 was exhibited superior swelling and strong mechanical characteristics than all the other hydrogels with different compositions. Furthermore, it was observed that the cefixime was released from the formulation of S40D60 in a sustainable manner and the drug release rate can be controlled by pH of the dissolution medium. According to these findings, it is suggested that the optimal formulation of S40D60 would be effectively performed in situ drug therapy for wound healing. 相似文献
pH-responsive hydrogels based on alginic acid grafted with acrylic acid and ethylene glycol dimethylacrylate in the presence of ammonium persulfate were developed for controlled delivery of Ketorolac tromethamine. The alginic acid based hydrogels were prepared by free radical polymerization technique. Increase in gel fraction was observed with the increase in alginic acid, acrylic acid, and ethylene glycol dimethylacrylate content. The dynamic swelling and drug release studies were conducted at two different pH values (pH 1.2 and 7.4). Maximum swelling and drug release were observed at pH 7.4. The characterization of prepared hydrogels was carried out by using Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, powder x-ray diffraction, and scanning electron microscopy. Similarly, in-vivo study was performed on rabbits and greater plasma drug concentration was achieved by fabricated hydrogels as compared to drug solution and commercial product Keten. Conclusively, the fabricated hydrogels can be considered as a potential candidate for controlled delivery of Ketorolac tromethamine. 相似文献
The development of electro-stimulated drug release devices is an innovative approach to attain the drug delivery in accurate doses at target sites in a programmed manner. In this work, novel electroactive nanocomposite hydrogels were prepared by encapsulating green-synthesized polypyrrole (PPy) colloids within chondroitin sulfate (CS) networks during the self-crosslinking of CS via N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide chemistry. The structural and morphological properties of CS/PPy hydrogels were studied by Fourier-transformed infrared spectroscopy, scanning electron microscopy, and swelling kinetic measurements. The chemotherapeutic agent 5-fluorouracil (5-FU) was loaded into CS/PPy samples by hydrogel swelling method, or alternatively, by pre-incubating the drug in polymer mixture before crosslinking. Different electrical stimulations can be used to switch ON and accurately tune the 5-FU delivery from GG/PPy hydrogels. A single pulse potential of 5 V switched on the drug delivery up to 90% from nanocomposite hydrogel, in contrast to the low 5-FU amount released in a passive form (< 20%). PPy electroactive behavior played a determining role as the main driving force in 5-FU release activation. Cytotoxicity of hydrogels with and without 5-FU was examined in normal and cancer cells. Considering the high cytotoxicity of 5-FU, the ON/OFF 5-FU release patterns evidenced the potential of CS/PPy hydrogels for electrically controlled drug delivery in implantable or transdermal drug release devices. 相似文献
Hydrophobically modified alginate hydrogels have great potential in drug delivery as they are biologically compatible and cost efficient. While previous works have shown successful protein, and hydrophobic and hydrophilic drug delivery, little information regarding the relationship between crosslinker density and drug release rate is known. This paper investigates the impact of crosslinker density and hydrophobic degree of substitution within modified alginate gels and solutions on the release kinetics using model hydrophobic drug, sulindac. Near zero‐order release was obtained for an extended period of 5 days. Drug release rates decreased as the crosslinker density within both modified alginate hydrogels and solutions increased. Release data fit well to a simplified Fickian relationship, suggesting that the release mechanism is diffusion‐limited. These release characteristics also correlate with bulk rheological measurements, indicating a strong interrelationship between the mechanical properties and the drug release characteristics of the hydrogels. 相似文献
The preparation of a novel polysaccharide interpenetrating polymer network based on calcium alginate and methacrylated hyaluronic acid is described. The effect of two different solvents, distilled water and 0.9?% (w/v) NaCl, on the matrix formation and on its physico-chemical properties was studied by means of rheological and mechanical measurements. Furthermore, the structural characterization of the hydrogels prepared in the different ionic strength conditions was carried out by small-angle X-ray scattering in order to obtain deeper information useful for the preparation of drug delivery systems. Finally, to evaluate the potential use of the novel matrix as a drug delivery system and, in particular, its suitability for modulated delivery of a bioactive protein, release experiments of horseradish peroxidase, as a model protein, were also carried out. 相似文献
In view of the pharmacological importance of dietary fibre, psyllium, to cure the constipation and diverticulitis, in the present study, an attempt has been made to modify psyllium polysaccharide with PVP to develop the hydrogel meant for slow and controlled drug delivery systems. The polymer was characterized by SEMs, FTIR, XRD, TGA and swelling studies. Swelling of hydrogels and drug (ciprofloxacin) release profile from the drug loaded hydrogels were determined for the evaluation of the swelling/release mechanism. Biomedical properties; biocompatibility and mucoadhesion of the hydrogels, were also studied. Swelling of the hydrogels and release of drugs from drug loaded hydrogels occurred through non-Fickian diffusion mechanism. Here it is pertinent to mention that both psyllium husk polysaccharide and antibiotic drug ciprofloxacin are used for gastrointestinal tract (GIT) problem, especially in case of diverticulitis. Hence, degradation of the polymer matrix and release of drug may exert the synergic effect and the present drug delivery system may act with enhanced potential. 相似文献
Nowadays, hydrogels-based microneedles (MNs) have attracted a great interest owing to their outstanding qualities for biomedical applications. For the fabrication of hydrogels-based microneedles as tissue engineering scaffolds and drug delivery carriers, various biomaterials have been tested. They are required to feature tunable physiochemical properties, biodegradability, biocompatibility, nonimmunogenicity, high drug loading capacity, and sustained drug release. Among biomaterials, human proteins are the most ideal biomaterials for fabrication of hydrogels-based MNs; however, they are mechanically weak and poorly processible. To the best of the knowledge, there are no reports of xeno-free human protein-based MNs so far. Here, human albumin-based hydrogels and microneedles for tissue engineering and drug delivery by using relatively new processible human serum albumin methacryloyl (HSAMA) are engineered. The resultant HSAMA hydrogels display tunable mechanical properties, biodegradability, and good biocompatibility. Moreover, the xeno-free HSAMA microneedles display a sustained drug release profile and significant mechanical strength to penetrate the model skin. In vitro, they also show good biocompatibility and anticancer efficacy. Sustainable processible human albumin-based biomaterials may be employed as a xeno-free platform in vivo for tissue engineering and drug delivery in clinical trials in the future. 相似文献
The present study deals with the modification of sterculia gum to develop the novel colon specific delivery system for use in colon cancer. The sterculia and acrylic acid based hydrogels were synthesized and characterized with FTIR, SEMs, TGA and swelling behavior. Swelling studies of the hydrogels were carried out as a function of reaction parameters such as monomer concentration, initiator concentration, amount of sterculia gum and crosslinker concentration and nature of swelling mediums. Swelling kinetics of the hydrogels and in vitro release dynamics of anticancer model drug methotrexate from the hydrogels were studied to evaluate the swelling mechanism and drug release mechanism from the drug-loaded hydrogels. The values of diffusion exponent for the release of drug were 0.883, 0.910 and 0.787 in distilled water, pH 2.2 buffer and pH 7.4 buffer, respectively. The release of drug from the polymer matrix occurred through a non -Fickian type diffusion mechanism. 相似文献
We investigate the phase transition behavior and dissolution resistant properties of thermo‐sensitive nanocomposite hydrogels made from PEO‐PPO‐PEO triblock copolymer (Pluronic F127) and Laponite silicate nanoparticles. The rapid dissolution properties of F127 copolymer hydrogels usually limit their use as sustained release drug carriers. We overcome this limitation by synergistic combination of nanoparticle gelation characteristics with polymer thermo‐sensitivity. We present a proof of concept that the temperature‐dependent phase transitions can be shifted as a function of hydrogel composition and that the dissolution of the polymer hydrogels as well as the release of a model drug, albumin, can be significantly slowed down by addition of nanoparticles. The dissolution resistant properties generated will prove useful in the future formulation, processing and application of our polymer hydrogels for sustained release drug delivery carriers.
Hydrogel‐based drug delivery systems can leverage therapeutically favorable upshots of drug release and found clinical uses. Hydrogels offer temporal and spatial control over the release of different therapeutic agents. Because of their tailor made controllable degradability, physical properties, and ability to prevent the labile drugs from degradation, hydrogels provide platform on which diverse physicochemical interactions with entrapped drugs cause to control drug release. Herein, we report the fabrication of novel vinyltrimethoxy silane (VTMS) cross‐linked chitosan/polyvinyl pyrrolidone hydrogels. Swelling in distilled water in conjunction with different buffer and electrolyte solutions was performed to assess the swellability of hydrogels. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X‐ray diffraction (XRD) analysis were further conducted to investigate the possible interactions between components, thermal stability, and crystallinity of as‐prepared hybrid hydrogels, respectively. In vitro time‐dependent biodegradability, antimicrobial study, and cytotoxicity were also carried out to evaluate their extensive biocompatibility and cytotoxic behavior. More interestingly, in vitro drug release study allowed for the controlled release of cephradine. Therefore, this facile strategy developed the novel biocompatible and biodegradable hybrid hydrogels, which could significantly expand the scope of these hydrogels in other biomedical applications like scaffolds, skin regeneration, tissue engineering, etc. 相似文献
Recent advances in the preparation/loading, surface properties, and applications of polymer-based colloidal drug delivery and release systems, such as block copolymer micelles, polymer nano- and microparticles, polymer-modified liposomes, and chemical and physical hydrogels are presented. Drug release from polymer-based systems is affected by the drug–polymer interactions as well as the polymer microstructure and dissociation/erosion properties. Surface modification with poly(ethylene oxide) has become common in improving the biocompatibility and biodistribution of drug delivery carriers. Site-specific drug delivery can be achieved by polymer-based colloidal drug carriers when ligands of targeting information are attached on the carrier surface or when a phase transition is induced by an external stimulus. While significant progress in being made, many challenges remain in preserving the biological activity and attaining the desired drug release properties, especially for protein and DNA drugs. 相似文献
Hydrogels, with self-healing properties that can self-repair spontaneously when subjected to mechanical stress, are gaining popularity in the biomedical field. Numerous attempts have been made to create distinctive hydrogels with self-healing properties, along with stimuli-responsiveness and biocompatibility. Several techniques exist for fabricating hydrogels, including physical and chemical crosslinking via the creation of covalent bonds, and so on. Here, we prepared self-healing, stimuli-responsive, mineralized hydrogel by simply dissolving Kollidon 90-F, sodium chloride (NaCl), and potassium carbonate (K2CO3) in an aqueous solution. The dissociated CO32− replaces the water molecules from the Kollidon 90-F polymer backbone and facilitates the cross-linking of the polymer chain, resulting in hydrogel formation. In addition, the in-situ produced sodium carbonate (Na2CO3) strengthens the hydrogel network. We optimized the mineralized hydrogels by taking various metal salts and different concentrations of K2CO3. The optimized hydrogel showed good stability over a period of time, was able to maintain viscoelastic properties, possessed good self-healing ability, and showed a shape retention ability. The shear-thinning property demonstrated by the optimized hydrogel could open a ray of hope in the bioprinting or 3D printing industry. Further, the stretch-responsive release of dye from the Self-healing mineralized hydrogel (SHMH) matrix confirms the mechanoresponsive behavior of the hydrogel. Overall, the findings could be utilized in the future to fabricate a stable drug delivery system that can autonomously release the drug molecules when stretched by daily processes such as joint movements. 相似文献