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

The Role of WO3 Nanoparticles on the Properties of Gelatin Films

Gelatin films are very versatile materials whose properties can be tuned through functionalization with different systems. This work investigates the influence of WO3 nanoparticles on the swelling, barrier, mechanical, and photochromic properties of gelatin films. To this purpose, polyvinylpirrolidone (PVP)-stabilized WO3 nanoparticles were loaded on gelatin films at two different pH values, namely, 4 and 7. The values of swelling and solubility of functionalized films displayed a reduction of around 50% in comparison to those of pristine, unloaded films. In agreement, WO3 nanoparticles provoked a significant decrease in water vapor permeability, whereas the decrease in the values of elastic modulus (from about 2.0 to 0.7 MPa) and stress at break (from about 2.5 to 1.4 MPa) can be ascribed to the discontinuity created by the nanoparticles inside the films. The results of differential scanning calorimetry and X-ray diffraction analysis suggest that interaction of PVP with gelatin reduce gelatin renaturation. No significant differences were found between the samples prepared at pH 4 and 7, whereas crosslinking with glutaraldehyde greatly influenced the properties of gelatin films. Moreover, the incorporation of WO3 nanoparticles in gelatin films, especially in the absence of glutaraldehyde, conferred excellent photochromic properties, inducing the appearance of an intense blue color after a few seconds of light irradiation and providing good resistance to several irradiation cycles.

Gelatin scaffold ameliorates proliferation & stem cell differentiation into the hepatic like cell and support liver regeneration in partial-hepatectomized mice model

Stem cell-based tissue engineering is an emerging tool for developing functional tissues of choice. To understand pluripotency and hepatic differentiation of mouse embryonic stem cells (mESCs) on a three-dimensional (3D) scaffold, we established an efficient approach for generating hepatocyte-like cells (HLCs) from hepatoblast cells. We developed porous and biodegradable scaffold, which was stimulated with exogenous growth factors and investigated stemness and differentiation capacity of mESCs into HLCs on the scaffoldin-vitro. In animal studies, we had cultured mESCs-derived hepatoblast-like cells on the scaffold and then, transplanted them into the partially hepatectomized C57BL/6 male mice model to evaluate the effect of gelatin scaffold on hepatic regeneration. The 3D culture system allowed maintenance of stemness properties in mESCs. The step-wise induction of mESCs with differentiation factors leads to the formation of HLCs and expressed liver-specific genes, including albumin, hepatocyte nucleic factor 4 alpha, and cytokeratin 18. In addition, cells also expressed Ki67, indicating cells are proliferating. The secretome showed expression of albumin, urea, creatinine, alanine transaminase, and aspartate aminotransferase. However, the volume of the excised liver which aids regeneration has not been studied. Our results indicate that hepatoblast cells on the scaffold implanted in PH mouse indicates that these cells efficiently differentiate into HLCs and cholangiocytes, forming hepatic lobules with central and portal veins, and bile duct-like structures with neovascularization. The gelatin scaffold provides an efficient microenvironment for liver differentiation and regeneration bothin-vitroandin-vivo. These hepatoblasts cells would be a valuable source for 3D liver tissue engineering/transplantation in liver diseases.

Anti-Oxidant Multi-Functionalized Materials: Strontium-Substituted Monetite and Brushite as Delivery Systems for Curcumin

Curcumin has numerous biological activities and pharmaceutical applications related to its ability to inhibit reactive oxygen species. Herein, strontium-substituted monetite (SrDCPA) and strontium-substituted brushite (SrDCPD) were synthesized and further functionalized with curcumin with the aim to develop materials that combine the anti-oxidant properties of the polyphenol, the beneficial role of strontium toward bone tissue, and the bioactivity of calcium phosphates. Adsorption from hydroalcoholic solution increases with time and curcumin concentration, up to about 5-6 wt%, without affecting the crystal structure, morphology, and mechanical response of the substrates. The multi-functionalized substrates exhibit a relevant radical scavenging activity and a sustained release in phosphate buffer. Cell viability, morphology, and expression of the most representative genes were tested for osteoclast seeded in direct contact with the materials and for osteoblast/osteoclast co-cultures. The materials at relatively low curcumin content (2-3 wt%) maintain inhibitory effects on osteoclasts and support the colonization and viability of osteoblasts. The expressions of Alkaline Phosphatase (ALPL), collagen type I alpha 1 chain (COL1A1), and osteocalcin (BGLAP) suggest that curcumin reduces the osteoblast differentiation state but yields encouraging osteoprotegerin/receptor activator for the NFkB factor ligand (OPG/RANKL) ratio.

Antioxidant polysaccharide/gelatin blend films loaded with curcumin - A comparative study

Curcumin (CUR; 0, 0.005, 0.01, 0.02 %) was loaded into binary 75/25 blend films based on polysaccharides (carboxymethyl cellulose (CMC), gum Arabic (GAR), octenyl succinic anhydride modified starch (OSA), water-soluble soy polysaccharides (WSSP)) and gelatin (GEL). The GAR-based system was the least rough and, consequently, the most transparent of the films. An opposite result was found for the WSSP-based film. Despite the phase separation, the CMC75/GEL25 film exhibited excellent mechanical strength and stiffness. CUR improved the UV/VIS light-barrier characteristics of the films, but did not affect most of other physiochemical properties. X-ray diffractograms revealed that CUR provoked the rearrangement of the triple helical structure of GEL. As highly erodible, the CMC75/GEL25 carrier ensured the fastest and the most complete release of CUR. The OSA75/GEL25 system exhibited an opposite behavior. The kinetic profiles of the antiradical activity of the films did not reflect CUR release. A comparison of 2,2-diphenyl-1-picrylhydrazyl (DPPH*) scavenging on the plateau revealed that the CUR-supplemented films had quite comparable antiradical potential. The CMC75/GEL25 system exhibited the highest colorimetric stability, likely as a result of complete encapsulation of CUR in the GEL-rich microspheres. Weak symptoms of physical aging (enthalpy relaxation) were found in the films.

Gelatin-Curcumin Nanocomposites as a Coating for Implant Healing Abutment: In Vitro Stability Investigation

Regarding the importance of preventing peri-implantitis in dental implants, the current study aimed to coat a healing abutment with gelatin−curcumin nanocomposites, and the stability of this coating on the healing abutment was evaluated. A cell viability measuring test was used to determine the cytotoxicity of nanocomposites against dental pulp stem cells. To show the pattern of curcumin release from nanocomposites, drug dissolution apparatus two was applied. Then, 16 healing abutments were examined in vitro. Titanium healing abutments were coated with the gelatin−curcumin nanocomposite. The dip coating method was applied for coating and the consistency of coated cases was evaluated at intervals of one, 30, and 60 days after coating inside the simulated body fluid (SBF) solution. A scanning electron microscope (SEM) was used for investigating the microstructure and morphology of coatings, and an energy dispersive X-ray (EDX) was applied for determining the combination of the coating. Moreover, the healings were weighed before and after coating via an accurate digital scale with an accuracy of 0.0001. Finally, the data were analyzed using SPSS software. The prepared nanocomposite was non-cytotoxic against tested cells. The nanocomposite showed a relatively rapid release pattern in the first 10 days for curcumin. The release of curcumin from the nanoparticles continued slowly until the 30th day. The weight changes were statistically significant (p-value < 0.001) during this time. Based on the post hoc test, the weight between two times immediately after coating and 30 days after coating, and also one day after coating and 30 days after coating, was statistically insignificant. The results revealed that the coating of the gelatin−curcumin nanocomposite on the healing was successful and this consistency was kept for at least one month. It is necessary to investigate more evaluations in different fields of physicochemical, mechanical, and antimicrobial aspects for coated healing abutments.

Inclusion of curcumin in b-cyclodextrin: a promising prospective as food ingredient

In the present work, the inclusion complexes between curcumin (CC) and β-cyclodextrin (β-CD) were obtained through co-precipitation at different times of magnetic stirring and simple mixing. The stoichiometric ratio between CC and β-CD was ascertained to be 1:2. The samples prepared by co-precipitation (24 h magnetic stirring and 24 h cold static precipitation) and by simple mixing, showed the best performance in terms of powder recovery (72 and 97%, respectively), encapsulation efficiency (72 and 95%, respectively) and tinting power, while no significant differences were revealed in terms of loading capacity (about 14%). Using either inclusion method, the complexation of CC into β-CD make the colorant 20-fold more water soluble than pure CC. The pigment stability was also enhanced under different storage conditions (high temperature and light exposure), either when applied in liquid or gel state. However, after 30 days under natural light exposure, an appreciable colour change from yellow to orange was revealed to an extent probably perceptible by an inexperienced observer.