Sustained Release Of Curcumin Research Articles

Polypeptide hydrogel loaded with conducting polymer nanoparticles as electroresponsive delivery system of small hydrophobic drugs

A hydrogel/nanoparticle-loaded system for the controlled delivery of small hydrophobic drugs has been prepared using poly(γ-glutamic acid) (PGGA), a naturally occurring biopolymer made of glutamic acid units connected by amide linkages between α-amino and γ-carboxylic acid groups, and poly(3,4-ethylenedioxythiophene) (PEDOT), a very stable conducting polymer with excellent electrochemical response. Specifically, curcumin (CUR)-loaded PEDOT nanoparticles (PEDOT/CUR) were incorporated to the PGGA hydrogel during the crosslinking reaction. After chemical, morphological and electrochemical characterization, the release profiles of PEDOT/CUR and PGGA/PEDOT/CUR system have been compared in absence and presence of electrical stimuli, which consisted on the application of a voltage of –0.5 V for 15 min every 24 h. Results show that the release is higher for electrically stimulated systems by more than twice, even though due to its hydrophobicity and poor solubility in water the release was relatively slow in both cases. This feature could be advantageous when the therapeutic treatment requires slow, controlled and sustained CUR release.

Curcumin and Graphene Oxide Incorporated into Alginate Hydrogels as Versatile Devices for the Local Treatment of Squamous Cell Carcinoma.

With the aim of preparing hybrid hydrogels suitable for use as patches for the local treatment of squamous cell carcinoma (SCC)-affected areas, curcumin (CUR) was loaded onto graphene oxide (GO) nanosheets, which were then blended into an alginate hydrogel that was crosslinked by means of calcium ions. The homogeneous incorporation of GO within the polymer network, which was confirmed through morphological investigations, improved the stability of the hybrid system compared to blank hydrogels. The weight loss in the 100–170 °C temperature range was reduced from 30% to 20%, and the degradation of alginate chains shifted to higher temperatures. Moreover, GO enhanced the stability in water media by counteracting the de-crosslinking process of the polymer network. Cell viability assays showed that the loading of CUR (2.5% and 5% by weight) was able to reduce the intrinsic toxicity of GO towards healthy cells, while higher amounts were ineffective due to the antioxidant/prooxidant paradox. Interestingly, the CUR-loaded systems were found to possess a strong cytotoxic effect in SCC cancer cells, and the sustained CUR release (~50% after 96 h) allowed long-term anticancer efficiency to be hypothesized.

Fabrication of rhamnogalacturonan-I enriched pectin-based emulsion gels for protection and sustained release of curcumin

Rhamnogalacturonan-I (RG-I) was considered to be incompatible with gel formation. Due to its important health benefits, our previous study reported synergistic gelation of RG-I enriched pectin from citrus membranes with sequential acidic and alkaline treatment. In the present study, we further fabricated RG-I enriched pectin-based emulsion gels with the synergistic gelation for hydrophobic bioactive encapsulation. The effect of oil fraction and interfacial compositions including pectin itself and Tween 20 on the physical properties and delivery characteristics of emulsion gels was investigated. As to interfacial compositions, pectin reduced syneresis and swelling ratio and increased water holding capacity. Oil fraction had no marked influence on syneresis and swelling ratio, but significantly increased water holding capacity. Particularly, all the emulsion gels showed an elastic behavior and a full structure recovery after shearing. Increase in pectin instead of Tween 20 onto the surface of oil droplets and oil fraction markedly improved their gel strength. Curcumin was encapsulated within the oil phase of emulsion gels. Improvement in gel strength provided enhanced protection of curcumin against heat-induced degradation. In vitro digestion revealed that interfacial compositions decelerated curcumin release by increasing the proportion of pectin onto the surface, but didn't change its bioaccessibility eventually. Increase in oil fraction accelerated curcumin release, but reduced its bioaccessibility. Overall, fabrication of RG-I enriched pectin-based emulsion gel with pectin itself as interfacial composition and low oil fraction would contribute to improving curcumin bioavailability for its sustained release, which should be further validated in vivo.

Remotely triggered curcumin release from stimuli‐responsive magneto‐polymericlayer‐by‐layerengineered nanoplatforms

AbstractCurcumin is a promising natural drug in cancer therapy. However, its therapeutic applicability is limited by its low solubility, short half‐life, and low bioavailability. In this work curcumin is encapsulated in stimuli‐responsive magneto‐polymeric nanoplatforms aiming at improving its bioavailability and efficiency for delivery in biological media. MnFe2O4magnetic nanoparticles (MNPs) were synthesized via thermal decomposition, coated with sodium citrate and then functionalized with multilayers of chitosan and sodium alginate, by means of the layer‐by‐layer deposition technique. A mesoporous polymeric‐magnetic nanoplatform was produced capable of a controlled and sustained release of curcumin under temperature, pH and alternating magnetic field (magnetic hyperthermia) stimuli. As the temperature and pH of the medium increased, an increase in the rate of curcumin release was observed in a two‐stage process, following the Gallagher‐Corrigan mathematical model. The use of magnetic hyperthermia resulted in a faster diffusion‐based release of curcumin. Increasing the number of polymer layers assembled on top of MNPs hinders the release of the curcumin molecules from innermost regions of the multilayers. These results show that magnetic hyperthermia provides a means for the controlled heat‐induced release of curcumin, which can lead to an enhanced therapeutic action for curcumin.

Encapsulation of Curcumin in a Ternary Nanocomplex Prepared with Carboxymethyl Short Linear Glucan-Sodium-Caseinate-Pectin Via Electrostatic Interactions.

This work chemically modified short linear glucan (SLG) by introducing a surface carboxymethyl group to obtain carboxymethylated SLG (CMSLG), then prepared CMSLG-based ternary nanocomplex particles based on electrostatic interactions with sodium-caseinate (NaCas) and pectin. These nanocomplex particles are homogeneous, generally exhibiting sizes of<200nm with spherical shape and negative surface charge. In addition, the results showed the increase in both the mass ratio of CMSLG and NaCas and the synthesis temperature can improve the colloidal stability of nanocomplex particles when they are exposed to simulated gastrointestinal fluids containing digestive enzymes. Moreover, nanocomplex particles have an exceptional capability to encapsulate curcumin, and this encapsulation efficiency increased as the mass ratios of CMSLG and NaCas were increased. The study also investigated the antioxidant activity and in vitro release properties of curcumin encapsulated by nanocomplex particles and found that CMSLG/NaCas/pectin had improved higher ABTS radical scavenging capacity and allowed for the controlled, sustained release of curcumin in simulated gastrointestinal fluid within 6hours. Thus, this study provides new insights into the design of a CMSLG-based ternary nanocomplex and its use as a potential oral delivery system for lipophilic bioactive compounds. PRACTICAL APPLICATION: Curcumin, as a sort of natural polyphenolic compound, has many physiologic functions such as anti-oxidation, anticancer, and prevention of Alzheimer's disease. However, the application of the curcumin has been limited by its poor water solubility and unstable physicochemical property. To solve this problem, the nanotechnology has been used to prepare the nano-delivery carriers for curcumin. This work prepared a ternary nanoparticle based on the carboxymethyl short linear glucan, sodium-caseinate, and pectin. The ternary nanoparticle can achieve a higher encapsulation efficiency for curcumin. In addition, the ternary nanoparticle can enhance the ABTS radical scavenging capacity and provided control and sustained release of curcumin in the simulated gastrointestinal fluid.

Bioinspired synthesis of protein/polysaccharide-decorated folate as a nanocarrier of curcumin to potentiate cancer therapy

Curcumin is a promising anticancer agent, but its clinical utilization has been hindered by its low solubility and bioaccessibility. To overcome these obstacles, we developed a natural protein-polysaccharide nanocomplex made from casein nanoparticles coated with a double layer of alginate and chitosan and decorated with folic acid (fCs-Alg@CCasNPs) for use as a nanocarrier for curcumin. The developed nanoformulation showed a drug encapsulation efficiency = 75%. The measured size distribution of fCs-Alg@CCasNPs was 333.8 ± 62.35 nm with a polydispersity index (PDI) value of 0.179. The recorded zeta potential value of fCs-Alg@CCasNPs was 28.5 mV. Morphologically, fCs-Alg@CCasNPs appeared spherical, as shown by transmission electron microscopy (TEM). The successful preparation of fCs-Alg@CCasNPs was confirmed by Fourier transform infrared (FTIR) spectroscopy of all the constituents forming the nanoformulation. Further in vitro investigations indicated the stability of fCs-Alg@CCasNPs as well as their controlled and sustained release of curcumin in the tumor microenvironment. Compared with free curcumin, fCs-Alg@CCasNPs induced a higher cytotoxic effect against a pancreatic cancer cell line. The in vivo pharmacokinetics of fCs-Alg@CCasNPs showed a significant AUC0-24 = 2307 ng.h/ml compared to 461 ng.h/ml of free curcumin; these results indicated high curcumin bioavailability in plasma. The in vivo results of tumor weight, the amount of DNA damage measured by comet assay and histopathological examination revealed that treating mice with fCs-Alg@CCasNPs (either intratumorally or intraperitonially) prompted higher therapeutic efficacy against Ehrlich carcinoma than treatment with free curcumin.Therefore, the incorporation of curcumin with protein/polysaccharide/folate is an innovative approach that can synergistically enhance curcumin bioavailability and potentiate cancer therapy with considerable biosafety.

Synthesis, characterization and application of chitosan-N-(4-hydroxyphenyl)-methacrylamide derivative as a drug and gene carrier

The aim of this study was to develop a green method to fabricate a novel CS modified N-(4-hydroxyphenyl)- methacrylamide conjugate (CSNHMA) and to evaluate its biomedical potential. CSNHMA has been prepared by a simple method via aza Michael addition reaction between CS and N- (4-hydroxyphenyl)-methacrylamide (NHMA) in ethanol. Its structural and morphological properties were characterized by various analysis techniques. The obtained results confirmed that a highly porous network structure of CSNHMA was successfully synthesized via aza Michael addition reaction. Consequently, it was analyzed as a drug and gene carrier. CSNHMA/pGL3 showed an enhanced buffering capacity due to the presence of NHMA moiety leading to higher transfection efficiency in all cancer cells (A549, HeLa and HepG2) as compared to native CS and Lipofectamine®. Therefore, these findings clearly support the possibility of using CSNHMA as a good transfection agent. For in vitro drug release study, we prepared CSNHMA nanoparticles (NPs) and curcumin loaded CSNHMA NPs of size <230 nm respectively via the non-toxic ionic gelation route and the encapsulation efficiency of drug was found to be 77.03%. In vitro drug release studies demonstrated a faster and sustained release of curcumin loaded CSNHMA NPs at pH 5.0 compared to physiological pH.

Ultrashort Peptides and Hyaluronic Acid-Based Injectable Composite Hydrogels for Sustained Drug Release and Chronic Diabetic Wound Healing.

Peptide hydrogels are widely used for biomedical applications owing to their good biocompatibility and unique advantages in terms of amino acid-based structures and functions. However, the exploration of the peptide/saccharide composite hydrogels as potential biomaterials for chronic diabetic wound healing is still limited. Herein, hyaluronic acid (HA) was incorporated into diphenylalanine (FF) conjugated with different aromatic moieties by a one-pot reaction. Our results showed that the dipeptide derivatives modified by benzene (B), naphthalene (N), and pyrene (P) self-assembled into composite hydrogels with uniform distribution and good mechanical properties in the presence of HA. The obtained N-FF/HA composite hydrogel exhibited greatly improved self-healing properties via injection syringe needle operation and good biocompatibility on human skin fibroblast (HSF) cells. Besides, the structure of thinner nanofibers and honeycomb networks inside the composite hydrogel allowed for a longer sustained release of curcumin, a hydrophobic drug for anti-inflammation and wound healing. The curcumin-loaded N-FF/HA composite hydrogels could promote chronic wound healing in the streptozotocin-induced type I diabetic mouse model. The results suggested that our developed saccharide-peptide hydrogels could serve as very promising synthetic biomaterials for applications in both drug delivery and wound healing in the future.

Fabrication and characterization of bamboo shoot cellulose/sodium alginate composite aerogels for sustained release of curcumin

The feasibility of using unmodified bamboo shoot cellulose (BSC) to produce composite aerogels with sodium alginate (SA) in a fast and green way for sustained release of curcumin was explored for the first time, in which calcium ion-induced SA cross-linking could effectively retain the structural stability of aerogel skeleton. The aerogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. The encapsulation and release of curcumin from aerogels were studied while the antioxidant activity of encapsulated curcumin was investigated. Curcumin was evenly encapsulated in the composite aerogels and showed a sustained release behavior, followed the first-order rate expression. Interpenetrating network structures were built between BSC and SA mainly through hydrogen bonding, which could be further reinforced by the cross-linking of CaCO3 on the SA matrix. The original characteristics of BSC in the composite aerogels were well retained. The thermal stability and mechanical properties of the composite aerogels were improved by Ca2+-induced cross-linking, while the uncross-linked composite aerogels exhibited better encapsulation efficiency and in vitro antioxidant activity. Overall, this study was the first to use cellulose from bamboo shoot to develop aerogels for drug delivery purposes. The cellulose/alginate composite aerogels were promising to be used as biocompatible carriers for drug and nutraceutical delivery.

Lemongrass derived cellulose nanofibers for controlled release of curcumin and its mechanism of action

The enzyme-based cellulose nanofibers from lemongrass waste were used as a potential carrier for the sustained release of curcumin, a natural anticancer polyphenol against different cancers. However, its low bioavailability, solubility and suboptimal pharmacokinetic issues limit its use in cancer therapeutics. The curcumin was encapsulated into the cellulose nanofibers with the highest encapsulation efficiency of ∼ 99% through homogeneous monolayer adsorption. Further, the binding of curcumin onto the cellulose nanofibers and its morphology were confirmed by FT-IR, molecular interaction study and SEM analysis. The controlled release profile of the encapsulated curcumin was determined at different simulated pH conditions, i.e., 1.2, 5.3, 6.8 and 7.4. At all pH conditions, the highest correlation was observed in Korsmeyer-peppas equation, indicating release occurred through diffusion. Moreover, the nanocomposite conserves the efficacy of curcumin in PC3 cell lines. Hence, the results suggest that the enzyme-based cellulose nanofibers are a good candidate for controlled release for curcumin without hindering its efficacy, which may be applied for pharmaceutical applications.

In-vitro evaluation of electrospun cellulose acetate nanofiber containing Graphene oxide/TiO2/Curcumin for wound healing application

Graphene-based dressings have gained interest in wound healing due to their biocompatibility and antimicrobial properties. This study developed a graphene oxide/TiO 2 /curcumin integrated cellulose acetate (CA) nanofiber for wound dressing applications. Electrospinning was used to fabricate the CA/GO/TiO 2 /curcumin nanofiber. The formation of CA nanofiber was clearly visible using FE-SEM. The presence of curcumin in CA/GO/TiO 2 /curcumin nanofiber was confirmed by FT-IR analysis. The prepared nanofiber was characterized by swelling, degradation, tensile strength, and in-vitro wound healing properties. CA/GO/TiO 2 /curcumin nanofiber demonstrated considerable antibacterial activity against wound pathogens and improved wound healing, as confirmed by MTT and migration assays. The fabricated CA/GO/TiO 2 /curcumin nanofiber exhibited exceptional hemocompatibility and biocompatibility. The drug release study revealed that sustained curcumin release would improve skin regeneration and wound healing. Invitro analysis confirmed that CA/GO/TiO 2 /curcumin nanofiber has the potential to be used as a wound dressing material. • Graphene oxide/TiO 2 /curcumin incorporated cellulose acetate (CA) nanofiber for wound dressing applications. • The CA/GO/TiO 2 /curcumin nanofiber was fabricated by electrospinning method. • Composite nanofibers enhances wound healing process which is confirmed by MTT and migration assay. • The sustained drug release behaviour would enhance skin regeneration. • In vitro analysis confirms that the CA/GO/TiO 2 /curcumin nanofiber is a suitable wound dressing material.

Electrospun PVP-Core/PHBV-Shell Fibers to Eliminate Tailing Off for an Improved Sustained Release of Curcumin.

Tailing off release in the sustained release of water-insoluble curcumin (Cur) is a significant challenge in the drug delivery system. As a novel solution, core-shell nanodrug containers have aroused many interests due to their potential improvement in drug-sustained release. In this work, a biodegradable polymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and hydrophilic polyvinylpyrrolidone (PVP) were exploited as drug delivery carriers by coaxial electrospinning, and the core-shell drug-loaded fibers exhibited improved sustained release of Cur. A cylindrical morphology and a clear core-shell structure were observed by scanning and transmission electron microscopies. The X-ray diffraction pattern and infrared spectroscopy revealed that Cur existed in amorphous form due to its good compatibility with PHBV and PVP. The in vitro drug release curves confirmed that the core-shell container manipulated Cur in a faster drug release process than that in the traditional PHBV monolithic container. The combination of the material and structure forms a novel nanodrug container with a better sustained release of water-insoluble Cur. This strategy is beneficial for exploiting more functional biomedical materials to improve the drug release behavior.

Influence of molecular interactions on structure, controlled release and cytotoxicity of curcumin encapsulated chitosan - Silica nanostructured microspheres

Curcumin possesses numerous medicinal benefits including anti-cancer and anti-viral properties. However, its wide scale use as a drug is often hindered owing to the dearth of suitable drug-delivery systems which can solubilise it for long-term sustained-release and safeguard its beneficial properties. In this work, a fast, one-step method, employing evaporation induced assembly of colloids, has been employed for the synthesis of curcumin encapsulated organic-inorganic hybrid micron-sized spheres. Detailed physical properties of the microspheres, with scaffolds of silica nanoparticles (∼8.5 nm) cross linked by chitosan, are studied to trace the underlying mechanism of structural assembly in such systems, by tuning the polymer matrix with solubilizing agents, DMSO and Tween 20. A systematic modification in the hydrogen bonding network, conformations and interactions between macromolecules is revealed upon tuning the organic matrix. This in turn is found to control the assembly vis-à-vis the granular morphology, drug entrapment and packing fraction of nanoparticles in the microspheres, which have direct influence on the biological properties. Consequently, the microspheres are found to follow a first order drug release kinetics with a tunable rate constant which follows the ordering of packing fraction of silica nanoparticles in the micro-granules. A sustained curcumin release for a period extending up to 24 h has been achieved. Further studies using human lung and cervical cancer cell lines assert good anti-cancer properties of these nanostructured microspheres in cancer cells, while showing no toxicity towards normal cells. Thus, such hybrid organic-inorganic formulations achieved using multi-component colloidal assembly approach, with enhanced stability against degradation, are promising candidates for future clinical applications of water-insoluble drugs.

Development of water-dispersible gelatin stabilized hydroxyapatite nanoformulation for curcumin delivery

The therapeutic efficacy of hydrophobic curcumin (CUR) can be potentially enhanced by developing aqueous formulations of CUR. In the present study, we have prepared colloidally stable formulation of CUR by encapsulating it into the hydrophilic network of gelatin (Gel) and hydroxyapatite (HAp). The successful incorporation of CUR in the formulation was evident from spectroscopic analysis. The detailed structural characterization of CUR loaded formulation (CUR-Gel-HAp) was carried out using various techniques including PXRD, FTIR, TGA, FESEM, light scattering, and zeta-potential measurements. The formulation showed pH responsive sustained release of CUR with higher release rate under acidic environment. CUR-Gel-HAp showed enhanced cytotoxicity towards human lung cancer cells (A549) as compared to normal human lung fibroblast cells (WI-26 VA4). Moreover, CUR-Gel-HAp exhibited substantial cellular internalization and higher toxicity towards A549 cells as compared to free CUR. Further, the lyophilized CUR-Gel-HAp exhibited long-term stability and showed insignificant changes in the physicochemical properties and colloidal stability upon reconstituting in the aqueous medium.

Curcumin in decellularized goat small intestine submucosa for wound healing and skin tissue engineering.

Biomaterials derived from extracellular matrices (ECMs) were extensively used for skin tissue engineering and wound healing. ECM is a complex network of biomolecules (e.g., proteins), which provide organizational support to cells for growth. Thus, ECM could be an ideal biomaterial for fabricating the scaffold. However, oxidative stress and biofilm formation at the wound site remains a major challenge that could be neutralized using herbal ingredients (e.g., curcumin). In this study, ECM was extracted from the biowaste of the goat abattoir by using decellularization. The goat small intestine submucosa (G-SIS) is decellularized to obtain the decellularized G-SIS (DG-SIS) and curcumin (in different concentrations) was incorporated in the DG-SIS to fabricate curcumin-embedded DG-SIS scaffolds. Changes brought by increasing the concentrations of the curcumin in DG-SIS were observed in various properties, including free radical scavenging and antibacterial properties. Results depicted that the scaffolds are porous, biodegradable, biocompatible, antibacterial, and hydrophilic and showed sustained release of curcumin. Besides, it showed free radicals scavenging property. The porosity and hydrophilicity of the scaffolds were decreased with an increase in the curcumin content. However, biodegradability, free radical scavenging, biocompatibility, and antibacterial properties of the scaffolds increased with an increase in the curcumin content. The DG-SIS scaffold containing 1 wt % of curcumin may be a potential biomaterial for wound-healing and skin tissue engineering.

Curcumin-Microsphere/IR820 Hybrid Bifunctional Hydrogels for In Situ Osteosarcoma Chemo-co-Thermal Therapy and Bone Reconstruction.

Conventional biomaterial-mediated osteosarcoma therapy mainly focuses on its antitumor effect yet often fails to overcome the problem of post-treatment bone tissue defect repair. Simultaneously, minimally invasive drug delivery methods are becoming spotlights for normal tissue preservation. Herein, an injectable curcumin-microsphere/IR820 coloaded hybrid methylcellulose hydrogel (Cur-MP/IR820 gel) platform was designed for osteosarcoma therapy and bone regeneration. In vitro, the K7M2wt osteosarcoma cells were eradicated by hyperthermia and curcumin. Later, the sustained release of curcumin promoted alkaline phosphatase expression and calcium deposition of bone mesenchymal stem cells. In vivo, this hybrid hydrogel could reach tumor site via injection and turned into hydrogel due to heat sensitivity. Under the irradiation of an 808 nm laser, localized hyperthermia (∼51 °C) generated in 5 min to ablate the tumor. Meanwhile, the thermal-accelerated curcumin release and thermal-increased cell membrane permeability led to tumor cell apoptosis. Tumors in photothermal-co-chemotherapy group were successfully restrained from day 2 after treatment. After that, bone reconstruction was promoted because of sustained released curcumin. The chemo-co-thermal efficacy and osteogenic capacity of Cur-MP/IR820 hydrogel suggest a promising approach to the treatment of osteosarcoma and provide provoking inspiration for treating bone tumors and repairing bone tissue.

Human-Induced Neural and Mesenchymal Stem Cell Therapy Combined with a Curcumin Nanoconjugate as a Spinal Cord Injury Treatment.

We currently lack effective treatments for the devastating loss of neural function associated with spinal cord injury (SCI). In this study, we evaluated a combination therapy comprising human neural stem cells derived from induced pluripotent stem cells (iPSC-NSC), human mesenchymal stem cells (MSC), and a pH-responsive polyacetal–curcumin nanoconjugate (PA-C) that allows the sustained release of curcumin. In vitro analysis demonstrated that PA-C treatment protected iPSC-NSC from oxidative damage in vitro, while MSC co-culture prevented lipopolysaccharide-induced activation of nuclear factor-κB (NF-κB) in iPSC-NSC. Then, we evaluated the combination of PA-C delivery into the intrathecal space in a rat model of contusive SCI with stem cell transplantation. While we failed to observe significant improvements in locomotor function (BBB scale) in treated animals, histological analysis revealed that PA-C-treated or PA-C and iPSC-NSC + MSC-treated animals displayed significantly smaller scars, while PA-C and iPSC-NSC + MSC treatment induced the preservation of β-III Tubulin-positive axons. iPSC-NSC + MSC transplantation fostered the preservation of motoneurons and myelinated tracts, while PA-C treatment polarized microglia into an anti-inflammatory phenotype. Overall, the combination of stem cell transplantation and PA-C treatment confers higher neuroprotective effects compared to individual treatments.

Curcumin-Functionalized Gelatin Films: Antioxidant Materials with Modulated Physico-Chemical Properties.

In this paper we used curcumin as a functionalizing agent of gelatin films with the aim to get antioxidant materials with modulated physico-chemical properties. To this aim, we prepared gelatin films at different contents of curcumin up to about 1.2 wt%. The as-prepared films, as well as glutaraldehyde crosslinked films, were submitted to several tests: swelling, water solubility, differential scanning calorimetry, X-ray diffraction, mechanical tests and curcumin release. The radical scavenging activity of the as-prepared films is similar to that of free curcumin, indicating remarkable antioxidant properties. All the other tested properties vary as a function of curcumin content and/or the presence of the crosslinking agent. In particular, the films exhibit sustained curcumin release in different solvents. Thanks to its biocompatibility, biodegradability and lack of antigenicity, gelatin uses span from food processing to packaging and biomaterials. It follows that the modulated properties exhibited by the functionalized materials developed in this work can be usefully employed in different application fields.

A rechargeable drug delivery system based on pNIPAM hydrogel for the local release of curcumin

AbstractThis study was designed to develop a drug delivery system based on poly(N‐isopropylacrylamide) (pNIPAM) hydrogel and a suitable solvent to enhance solubility and local release of curcumin. pNIPAM hydrogel was synthesized by radical polymerization. The chemical, mechanical and physical properties and biocompatibility of pNIPAM hydrogel were investigated as an implantable and rechargeable drug reservoir. Curcumin was loaded within pNIPAM hydrogel during swelling by using two different solvents; methanol, an organic solvent, and low molecular weight polyethylene glycol (PEG200), a polymeric solvent. The results of drug solubility showed that using PEG200 can increase curcumin solubility more than commonly used organic solvents such as methanol. Also, the release profile of drug‐loaded hydrogels demonstrated that PEG200 has a superior effect on the cumulative amount of released curcumin (33.163 ± 0.319 μg/ml) compared to methanol (8.765 ± 0.544 μg/ml) during 1 week. Based on our results, curcumin‐loaded hydrogels did not show any cytotoxicity, and pNIPAM/PEG combination represented an antibacterial effect within 12 hours. Accordingly, it can be concluded that pNIPAM hydrogel in combination with low molecular weight PEG200 could be used as an efficient drug delivery system to preserve and provide sustained release of curcumin as a hydrophobic drug.

Delivery of curcumin using a zein-xanthan gum nanocomplex: Fabrication, characterization, and in vitro release properties

This study aimed to use xanthan gum as a stabilizer to improve the stability of zein nanoparticles. Zein-xanthan gum composite nanoparticles were prepared via anti-solvent precipitation at pH 4.0. The particle size, zeta potential, and stability of the system were related to the amount of xanthan gum added. When 20 mg of xanthan gum was added, spherical nanoparticles with a small particle size (179 ± 2.1 nm) and sufficient negative zeta potential (−42 ± 1.6 mV) were obtained. The zeta potential and Fourier transform infrared spectroscopy results indicated that electrostatic attraction was the main driving force, followed by hydrogen bonding and hydrophobic interactions. Composite nanoparticles were coated by xanthan gum and remained stable over a wide pH range and at high temperatures and salt concentrations; they did not precipitate or aggregate after 30 days of storage. Moreover, the addition of xanthan gum considerably improved the encapsulation efficiency and loading capacity of nanoparticles containing high curcumin amounts, which facilitated slow and sustained release of curcumin in simulated intestinal fluid. Therefore, zein-xanthan gum nanoparticles can be used for the delivery of biologically active compounds in food and pharmaceutical preparations.